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0000-0001-7228-5787
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Publisher: Springer Science and Business Media LLC
Date: 1976
DOI: 10.1038/259305A0
Abstract: 1. An inhibitor of angiotensin-I-converting enzyme activity (D-3-mercapto-2-methylpropanoyl-L-proline, Captopril) was given to five chronically cannulated pregnant ewes and eleven rabbits in late pregnancy. 2. Within 2 min of administration to the sheep, Captopril had blocked the maternal conversion of angiotensin I to II, as assessed by the pressor response evoked by the i.v. administration of angiotensin I. Maternal and fetal basal systemic blood pressures had fallen within 10 min of administration. Although maternal systemic blood pressure returned to basal levels within 2 hr, fetal pressures remained low for up to 2 days. 3. All ewes went into spontaneous labour at or near term. One lamb was live-born but very weak and failed to establish suckling. The remaining seven lambs were fresh still-births. 4. Gestation length was significantly prolonged in the treated rabbits by comparison with ten controls. The still-birth rate was 37% in the treated animals and 6% in the controls (P less than 0.001). 5. It is concluded that the administration of Captopril to the two species studied is harmful to the fetus. The observations suggest that the drug rapidly crosses the placenta, and may cross the blood-brain barrier to exert a central effect. It may also interfere with the normal initiation of parturition.
Publisher: Wiley
Date: 03-09-2010
Publisher: Elsevier BV
Date: 1969
DOI: 10.1016/0010-406X(69)91353-X
Abstract: Emigration of healthcare workers from developing countries is on the rise and there is an urgent need for policies that increase access to and continuity of healthcare. In this commentary, we highlight some of the negative impacts of emigration on maternal and child health and discuss whether team-based healthcare delivery could possibly mitigate the shortfall of maternal and child health professionals in developing countries. We cross-examine the availability of supporting structures to implement team-based maternal and child healthcare delivery in developing countries. We briefly discuss three key supporting structures: culture of sharing, telecommunication, and inter-professional education. Supporting structures are examined at system, organizational and in idual levels. We argue that the culture of sharing, limited barriers to inter-professional education and increasing access to telecommunication will be advantageous to implementing team-based healthcare delivery in developing countries. Although most developing countries may have notable supporting structures to implement team-based healthcare delivery, the effectiveness of such models in terms of cost, time and infrastructure in resource limited settings is still to be evaluated. Hence, we call on usual stakeholders, government, regulatory colleges and professional associations in countries with longstanding emigration of maternal and child healthcare workers to invest in establishing comprehensive models needed to guide the development, implementation and evaluation of team-based maternal and child healthcare delivery.
Publisher: Springer Science and Business Media LLC
Date: 12-1991
DOI: 10.1007/BF00317715
Publisher: Elsevier BV
Date: 11-1969
DOI: 10.1016/0010-406X(69)90065-6
Abstract: Stem cell antigen-1-positive (Sca-1+) cardiac stem cells (CSCs) therapy for myocardial regeneration following acute myocardial infarction (AMI) is limited by insufficient cell viability and a high rate of apoptosis, due to the poor regional microenvironment. Resveratrol, which is a compound extracted from red wine, has been reported to protect myocardial tissue post‑AMI by increasing the expression of angiogenic and chemotactic factors. The present study aimed to investigate the effects of resveratrol on Sca‑1+ CSCs, and to optimize Sca‑1+ CSCs therapy for myocardial regeneration post‑AMI. C57/BL6 mice (age, 6 weeks) were ided into two groups, which received intragastric administration of PBS or 2.5 mg/kg.d resveratrol. The endogenous expression of Sca‑1+ CSCs in the heart was assessed on day 7. Furthermore, C57/BL6 mice underwent left anterior descending coronary artery ligation for the construction of an AMI model, and received an injection of 1x106 CSCs into the peri‑ischemic area (n=8/group). Mice received intragastric administration of PBS or resveratrol (2.5 mg/kg.d) for 4 weeks after cell transplantation. Echocardiography was used to evaluate cardiac function 4 weeks after cell transplantation. Capillary density and cardiomyocyte apoptosis in the peri‑ischemic myocardium were assessed by cluster of differentiation 31 immunofluorescent staining and terminal deoxynucleotidyl transferase‑mediated dUTP nick end labeling assay, respectively. Western blot analysis was conducted to detect the protein expression levels of vascular endothelial growth factor (VEGF) and stromal cell‑derived factor (SDF)‑1α in the myocardium. Treatment with resveratrol increased the number of endogenous Sca‑1+ CSCs in heart tissue after 7 days (PBS vs. Res, 1.85±0.41/field vs. 3.14±0.26/field, P<0.05). Furthermore, intragastric administration of resveratrol significantly increased left ventricle (LV) function 4 weeks after AMI, as determined by an increase in LV fractional shortening (CSCs vs. Res + CSCs, 28.82±1.58% vs. 31.18±2.02%, P<0.05), reduced LV end‑diastolic diameter (CSCs vs. Res + CSCs, 0.37±0.01 mm vs. 0.35±0.02 mm, P<0.05), and reduced LV end‑systolic diameter (CSCs vs. Res + CSCs, 0.26±0.01 mm vs. 0.23±0.02 mm, P<0.05). These protective effects were predominantly achieved via an increase in capillary density (CSCs vs. Res + CSCs, 281.02±24.08/field vs. 329.75±36.69/field, P<0.05) and a reduction in cardiomyocyte apoptosis (CSCs vs. Res + CSCs, 1.5±0.54/field vs. 0.83±0.40/field, P<0.05) in peri‑ischemic myocardium. Western blot analysis indicated that VEGF and SDF‑1α were upregulated in resveratrol‑treated myocardium after a 7 day treatment or 4 weeks after AMI (7 days VEGF PBS vs. Res, 0.89±0.07 vs. 1.21±0.02, P<0.05 SDF‑1α PBS vs. Res, 0.66±0.04 vs. 1.33±0.04, P<0.05 4 weeks VEGF CSCs vs. Res + CSCs, 0.54±0.03 vs. 0.93±0.13, P<0.05 SDF‑1α CSCs vs. Res + CSCs, 0.53±0.03 vs. 0.93±0.03, P<0.05). Resveratrol activated endogenous CSCs, increased capillary density and decreased cardiomyocyte apoptosis in the peri‑ischemic myocardium, and augmented the effects of CSCs transplantation. These effects may be caused by the upregulation of VEGF and SDF‑1α.
Publisher: University of Chicago Press
Date: 1984
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/AM04145
Abstract: Fur or feathers provide protection against heat loads from solar radiation for birds and mammals. The red kangaroo (Macropus rufus) and the emu (Dromaius novaehollandiae) are conspicuous in arid environments of Australia where there is potential for high solar loads. The diurnal D. novaehollandiae feeds in the open yet it has a dark coat with a high absorptivity (83%), which contrasts with that of M. rufus (61%), but M. rufus generally shelters in shade during the day. We examined the effect of coat characteristics on the heat load from solar radiation at skin level. Coat depth and density (thermal conductance or insulation) and the level of penetration of solar radiation into the coat were important determinants of solar heat load. For M. rufus less than 25% of incident radiation reached the body at low wind speeds and this diminished to below 15% at moderate wind speeds. In the modest shade M. rufus seeks on summer days, their heat load from solar radiation appears minimal. Colour differences among M. rufus did not affect thermal load. D. novaehollandiae on the other hand is exposed to the full incident solar load in the open but its plumage provides almost complete protection from solar radiation. Solar radiation is absorbed at the feather surface and the insulation provided by the deep coat prevents heat transmission to the skin.
Publisher: University of Chicago Press
Date: 03-1994
Publisher: CSIRO Publishing
Date: 1969
DOI: 10.1071/ZO9690777
Abstract: The seasonal variation in the plasma and urine electrolyte concentration and osmolality of the arid zone kangaroos Megaleia rufa (red kangaroo) and Macropus robustus (euro) has been examined. The urine osmolality of both species appeared to be influenced by environmental temperatures and also the status of feed. The osmolality of urine from red kangaroos was generally higher than that from euros. However, the relative medullary thickness of euro kidneys was greater than that of red kangaroo kidneys, indicating that euros may have the greater urine-concentrating capability. The pattern of sodium and potassium excretion indicated that species of Atriplex (saltbush) and Kochia (bluebush), which are high in sodium relative to potassium, may comprise a major part of the diet of the red kangaroo and euro in western New South Wales.
Publisher: Elsevier BV
Date: 06-1994
Publisher: Elsevier BV
Date: 1980
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/WR9920065
Abstract: The bridled nailtail wallaby (Onychogalea fraenata) is one of Australia's rarest marsupials, persisting only in a small area in central Queensland. Its diet and those of two sympatric herbivores, the blackstriped wallaby (Macropus dorsalis) and domestic cattle (Bos taurus/indicus), were assessed by identifying plant fragments in their faeces. The diet of 0 . fraenata was erse, consisting of herbaceous plants, grasses and browse. In good seasons the intake was biased towards forbs and other herbaceous plants. Browse was only important when vegetation availability was low. Grass could be a major part of the diet when forbs were scarse. Black-striped wallabies and cattle were largely grass eaters. When conditions were dry, browse contributed up to 16% of the diet of M. dorsalis and 10% of the diet of cattle. Dietary overlap with 0. fraenata was greatest at such times, being above 50% for both species. Potential for dietary competition was apparent and it is suggested that this may have been a factor in the decline of 0 . fraenata with the advancement of European settlement and spread of domestic stock.
Publisher: CSIRO Publishing
Date: 2012
Abstract: This book provides a clear and accessible account of kangaroos, showing how their reproductive patterns, social structure and other aspects of their biology make them well adapted to Australia’s harsh climate and demanding environment. Since the last edition of this book nearly 20 years ago, much more is now known about the biology and ecology of these iconic animals. This completely revised edition describes these new perspectives and attempts to counter the many urban and rural myths that still exist.
Publisher: University of Chicago Press
Date: 05-2000
DOI: 10.1086/316752
Abstract: We studied ventilation in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus), respectively, within the range of ambient temperatures (T(a)) from -5 degrees to 45 degrees C. At thermoneutral temperatures (Ta=25 degrees C), there were no differences between the species in respiratory frequency, tidal volume, total ventilation, or oxygen extraction. The ventilatory patterns of the kangaroos were markedly different from those predicted from the allometric equation derived for placentals. The kangaroos had low respiratory frequencies and higher tidal volumes, even when adjustment was made for their lower basal metabolism. At Ta>25 degrees C, ventilation was increased in the kangaroos to facilitate respiratory water loss, with percent oxygen extraction being markedly lowered. Ventilation was via the nares the mouth was closed. Differences in ventilation between the two species occurred at higher temperatures, and at 45 degrees C were associated with differences in respiratory evaporative heat loss, with that of M. giganteus being higher. Panting in kangaroos occurred as a graded increase in respiratory frequency, during which tidal volume was lowered. When panting, the desert red kangaroo had larger tidal volumes and lower respiratory frequencies at equivalent T(a) than the eastern grey kangaroo, which generally inhabits mesic forests. The inference made from this pattern is that the red kangaroo has the potential to increase respiratory evaporative heat loss to a greater level.
Publisher: Elsevier BV
Date: 10-1995
Publisher: Elsevier BV
Date: 1977
Publisher: CSIRO Publishing
Date: 1968
DOI: 10.1071/ZO9680603
Abstract: The blood volume of T. vulpecula was measured and the influence of the spleen on the circulating blood volume investigated. The circulating blood volume of "normal" restrained animals was 57.4 � 3.19 ml, the plasma volume being 31.2 � 1.93 ml, and the red blood cell volume 26.2 � 2.08 ml per kilogram body weight. These values tended to be lower than those of eutherian mammals and it is suggested that this might be associated with a possible lower metabolic rate. The spleen was found to have a significant function as a blood reservoir. Measurement of volume of circulating red blood cells after injections of adrenaline (to cause splenic emptying) and chlorpromazine (to achieve maximum filling of the spleen) showed that the splenic reserve of erythrocytes was approximately 11.0 ml/kg body weight.
Publisher: University of Chicago Press
Date: 05-2000
DOI: 10.1086/316751
Abstract: We examined thermoregulation in red kangaroos (Macropus rufus) from deserts and in eastern grey kangaroos (Macropus giganteus) from mesic forests/woodlands. Desert kangaroos have complex evaporative heat loss mechanisms, but the relative importance of these mechanisms is unclear. Little is known of the abilities of grey kangaroos. Our detailed study of these kangaroos' thermoregulatory responses at air temperatures (T(a)) from -5 degrees to 45 degrees C showed that, while some differences occur, their abilities are fundamentally similar. Both species show the basic marsupial characteristics of relatively low basal metabolism and body temperature (T(b)). Within the thermoneutral zone, T(b) was 36.3 degrees + or - 0.1 degrees C (X + or - SE) in both species, and except for a small rise at T(a) 45 degrees C, T(b) was stable over a wide range of T(a). Metabolic heat production was 25% higher in red kangaroos at T(a) -5 degrees C. At the highest T(a) (45 degrees C), both species relied on evaporative heat loss (EHL) to maintain T(b) both panting and licking were used. The eastern grey kangaroo utilised panting (76% of EHL) as the principal mode of EHL, and while this was so for red kangaroos, cutaneous evaporative heat loss (CEHL) was significant (40% of EHL). CEHL appeared to be mainly licking, as evidenced from surface temperatures. Both species utilised peripheral vascular adjustments to control heat flow, as indicated by changes in dry conductance (C(dry)). At lower temperatures, C(dry) was minimal, but it increased significantly at T(a) just below T(b) (33 degrees C) in these conditions, the C(dry) of red kangaroos was significantly higher than that of eastern grey kangaroos, indicating a greater reliance on dry heat loss. Under conditions where heat flows into the body from the environment (T(a) 45 degrees C), there was peripheral vasoconstriction to reduce this inflow C(dry) decreased significantly from the values seen at 33 degrees C in both kangaroos. The results indicated that, while both species have excellent thermoregulatory abilities, the desert red kangaroos may cope better with more extreme temperatures, given that they respond to T(a) 45 degrees C with lower respiratory evaporation than do the eastern grey kangaroos.
Publisher: Elsevier BV
Date: 07-1984
Publisher: American Physiological Society
Date: 05-1966
Publisher: Informa UK Limited
Date: 06-2016
DOI: 10.1071/MU9840093
Publisher: Springer Science and Business Media LLC
Date: 1981
DOI: 10.1007/BF00782599
Publisher: CSIRO Publishing
Date: 1975
DOI: 10.1071/ZO9750453
Abstract: Among the marsupials the thermoregulatory response of sweating is uncommon and has only been described in the larger macropodids. Sweating in kangaroos is very unusual in that it only occurs in response to an exercise heat load. The thermoregulatory responses of a smaller, more generalized rat-kangaroo Potorous tridactylus were therefore examined to obtain a more general appreciation of sweating in macropodids. The pattern of heat balance at low and neutral temperatures was characteristic of that previously found for macropodids body temperature was 35.9 � 0.52 (mean � se). Standard metabolism was only slightly higher than the predicted level for marsupials and minimal conductance was low, c. 1.3 W m-2 per degree Celsius. At moderate air temperatures heat was primarily lost by vasodilation and panting. The thermoregulatory responses at high air temperatures (near or above body temperature) also included copious sweating from the tail, but not from the body generally. Sweating rates of 600-650 g water per m2 per hour were obtained these are about twice the generally reported rates for eutherians such as cows and horses.
Publisher: University of Chicago Press
Date: 11-2001
DOI: 10.1086/324568
Abstract: The population dynamics of red kangaroos (Macropus rufus) in the Australian arid zone is tightly linked with environmental factors, which partly operate via the survival of juvenile animals. A crucial stage is the young-at-foot (YAF) stage when kangaroos permanently exit the pouch. We have examined the thermal biology of YAF red kangaroos during ages from permanent pouch exit until weaning. Over a wide range of environmental temperatures (ambient temperature [T(a)] -5 degrees to 45 degrees C), YAF red kangaroos had a mass-specific metabolism that was generally twice that of adults, considerably higher than would be expected for an adult marsupial of their body size. The total energy requirements of YAF red kangaroos were 60%-70% of those of adult females, which were three times their size. Over the same range in T(a), YAF red kangaroos also had total evaporative water losses equal to those of adult females. At the highest T(a) (45 degrees C), differences were noted in patterns of dry heat loss (dry conductance) between YAF red kangaroos and adult females, which may partially explain the relatively high levels of evaporative cooling by YAF. By weaning age, young kangaroos showed little change in their basal energy and water requirements (at T(a) 25 degrees C) but did show reduced mass-specific costs in terms of energy and water use at extremes of T(a) (-5 degrees and 45 degrees C, respectively). In their arid environment, typified by unpredictable rainfall and extremes of T(a), young red kangaroos may need to remain close to water points, which, in turn, may restrict their ability to find the high-quality forage needed to meet their high energy demands.
Publisher: University of Chicago Press
Date: 03-1995
Publisher: American Physiological Society
Date: 04-1970
DOI: 10.1152/AJPLEGACY.1970.218.4.1233
Abstract: Transcript elongation factors (TEFs) are a heterogeneous group of proteins that control the efficiency of transcript elongation of subsets of genes by RNA polymerase II (RNAPII) in the chromatin context. Using reciprocal tagging in combination with affinity purification and mass spectrometry, we demonstrate that in
Publisher: Wiley
Date: 24-02-2011
Publisher: Springer Science and Business Media LLC
Date: 06-10-2005
DOI: 10.1007/S00360-005-0030-2
Abstract: The Eastern Grey Kangaroo (Macropus giganteus) occurs mostly in the wetter regions of eastern Australia. However, in the past 30-40 years it has moved into more arid regions (rainfall < 250 mm), thus increasing its overlap zone with the xeric adapted Red Kangaroo (Macropus rufus). An increased access to water (supplied for domestic stock) may explain this range extension, but changes in the availability of preferred feed could also be involved. The water use, drinking patterns and thermoregulatory behaviour of these two species of kangaroo have been examined in a semi-free range study, during summer at an arid rangeland site. Foraging was largely nocturnal in both species and during the day they behaved to reduce heat loads. This was especially so for M. giganteus, which showed greater shade seeking. However, it still used more water (72 +/- 2.6 mL kg(-1) day(-1), mean +/- SE) than M. rufus (56 +/- 7.6 mL kg(-1) day(-1)) and drank twice as frequently. Although M. giganteus produced a less concentrated urine (1422 +/- 36 mosmol kg(-1)) than M. rufus (1843 +/- 28 mosmol kg(-1)), kidney physiology did not explain all of the differences in water metabolism between the species. Water from the feed and faecal water retention also appear to be involved. Broadly, a better access to reliable water and the utilisation of mesic microhabitats has enabled M. giganteus to make inroads into the changing rangelands of eastern Australia. However, changes in the vegetation, due to stock grazing, have also favoured M. giganteus, which is a grass eating specialist.
Publisher: CSIRO Publishing
Date: 1977
DOI: 10.1071/WR9770127
Abstract: Stomach contents of free-ranging animals were analysed botanically for low Atriplex shrubland in western New South Wales, Australia, during 1972-74 in good seasons producing abundant growth and ersity of vegetation. Red kangaroo (Megaleia rufa), euro (Macropus robustus) and sheep (Ovis aries) selected grass and forbs when those were readily available. In poorer pasture sheep selected mainly flat-leaved chenopods (saltbush) and kangaroos selected mainly grass with different amounts of flat- or round-leaved chenopods. Euros were the most selective, eating grass even when there was little grass present. Potential overlaps in diet between kangaroos and sheep were greatest in good pasture and least in the poorest conditions. The other groups of plants considered were non-chenopod shrubs and browse. Extent of overlap was not clear, because animals may have eaten different species within the groups of plants. The study period did not include any severe drought, in which overlap in diet and competition between animal species would have been most significant.
Publisher: Wiley
Date: 08-1968
DOI: 10.1038/ICB.1968.106
Publisher: Springer Science and Business Media LLC
Date: 09-2003
DOI: 10.1007/S00360-003-0367-3
Abstract: Generally, young growing mammals have resting metabolic rates (RMRs) that are proportionally greater than those of adult animals. This is seen in the red kangaroo ( Macropus rufus), a large (>20 kg) herbivorous marsupial common to arid and semi-arid inland Australia. Juvenile red kangaroos have RMRs 1.5-1.6 times those expected for adult marsupials of an equivalent body mass. When fed high-quality chopped lucerne hay, young-at-foot (YAF) kangaroos, which have permanently left the mother's pouch but are still sucking, and recently weaned red kangaroos had digestible energy intakes of 641+/-27 kJ kg(-0.75) day(-1) and 677+/-26 kJ kg(-0.75) day(-1), respectively, significantly higher than the 385+/-37 kJ kg(-0.75) day(-1) ingested by mature, non-lactating females. However, YAF and weaned red kangaroos had maintenance energy requirements (MERs) that were not significantly higher than those of mature, non-lactating females, the values ranging between 384 kJ kg(-0.75) day(-1) and 390 kJ kg(-0.75) day(-1) digestible energy. Importantly, the MER of mature female red kangaroos was 84% of that previously reported for similarly sized, but still growing, male red kangaroos. Growth was the main factor affecting the proportionally higher energy requirements of the juvenile red kangaroos relative to non-reproductive mature females. On a good quality diet, juvenile red kangaroos from permanent pouch exit until shortly after weaning (ca. 220-400 days) had average growth rates of 55 g body mass day(-1). At this level of growth, juveniles had total daily digestible energy requirements (i.e. MER plus growth energy requirements) that were 1.7-1.8 times the MER of mature, non-reproductive females. Our data suggest that the proportionally higher RMR of juvenile red kangaroos is largely explained by the additional energy needed for growth. Energy contents of the tissue gained by the YAF and weaned red kangaroos during growth were estimated to be 5.3 kJ g(-1), within the range found for most young growing mammals.
Publisher: University of Chicago Press
Date: 11-1987
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/AM04153
Abstract: Although hopping is a relatively rare mammalian gait, hopping mammals are common in arid environments. Arid environments are open, with patchy resources, and the widespread use of hopping by arid zone mammals appears to be related to the benefits of fast locomotion. In several species, fast hopping is economical in comparison to fast quadrupedal running. These hopping species can reach greater maximum aerobic speeds than similarly sized runners. Faster locomotion can reduce predation risk and increase opportunities to exploit open microhabitats. More economical locomotion may improve a hopping mammal's ability to adopt alternative foraging strategies. The disadvantages of hopping include an increased cost of slow locomotion, reduced manoeuvrability at slow speeds and reduced ability to exploit densely vegetated patches.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/ZO00038
Abstract: The eastern grey kangaroo (M. giganteus) is usually found in mesic habitats but in the past 30–40 years it has expanded its range into arid rangelands. A suggested reason for this expansion has been the provision of additional water sites for domestic stock. In this study we examined aspects of kidney function and water metabolism of M. giganteus. This was done during normal hydration and water restriction so that the water-conserving abilities of M. giganteus could be compared with those of the red kangaroo (M. rufus), the habitat of which is arid rangelands and desert. The indices relative medullary thickness (RMT) and medullary to cortical ratio, derived from the morphology of the kidney, are indicators of renal concentrating ability. In M. giganteus both these indices were lower than in M. rufus: the RMT was 5.24 0.15 (mean s.e.) for M. giganteus and 6.00 0.10 for M. rufus. Measured maximal urine concentrations of these species were 2444 59 (M. giganteus) and 3135 165 mosmol kg–1 (M. rufus), with the respective maximum in idual concentrations being 2752 and 4054 mosmol kg–1. Kidney function in hydrated and dehydrated M. giganteus was assessed via glomerular filtration rate, urine flow rate and concentration index. As measured by these parameters, M. giganteus had renal water-conserving capacities similar to, or superior to, those of many comparable-sized arid-zone-inhabiting placental mammals, but below those of M. rufus. Water metabolism, as measured by water turnover, showed a similar pattern.
Publisher: Springer Science and Business Media LLC
Date: 1994
DOI: 10.1007/BF00714584
Publisher: American Physiological Society
Date: 07-1975
DOI: 10.1152/AJPLEGACY.1975.229.1.251
Abstract: The effect of dehydration on the distribution of water in the bodies of two species of desert kangaroos, the red kangaroo Megaleia rufa and the euro Macropus robustus, has been examined. The volumes of various body-fluid compartments were determined in normally hydrated animals and then after the kangaroos had been dehydrated until body weight declined to 80% of the initial weight. The fluid compartments examined were total body water, plasma volume, intracellular volume (cellular and gut water), and extracellular volume. Both species were camel-like in their response to dehydration in that plasma volume was maintained in both species, falling by only 8.3% in red kangaroos and 7.4% in euros. The pattern of water loss from other compartments differed between species, particularly gut water loss. This compartment, which includes the large rumenlike fore stomach, contributed 56% of the total water loss of red kangaroos but only 22% of the loss from euros. The ecological implications of the preferential maintenance of gut water by the sedentary, cave-dwelling euros have been discussed.
Publisher: No publisher found
Date: 1966
Publisher: Elsevier BV
Date: 02-1974
DOI: 10.1016/0300-9629(74)90025-5
Abstract: Secretory breast carcinoma (SBC) is a rare tumor that was originally described in children and adolescent women, with a characteristic morphology and controversy regarding the choice of treatment. This unusual breast cancer subtype generally has a favorable prognosis, although several cases have been described in adults with increased tumor aggressiveness and a risk of metastases. Surgery is considered the most appropriate treatment for this pathology. The present study describes the case of a 12-year-old female who presented with a painless lump in the left breast, and subsequently underwent a biopsy of the sentinel lymph node and a partial resection of the left breast (breast-conserving therapy). Periodic follow-up examinations after completion of the surgical and chemotherapeutic treatment have shown no evidence of either local regression or distant metastases and, one year later, the patient remains free of the disease. This study suggests that local excision with sentinel lymph node mapping may be a suitable therapeutic approach for children with SBC.
Publisher: Springer Science and Business Media LLC
Date: 11-2016
DOI: 10.1007/S00360-016-1043-8
Abstract: Not all of the solar radiation that impinges on a mammalian coat is absorbed and converted into thermal energy at the coat surface. Some is reflected back to the environment, while another portion is reflected further into the coat where it is absorbed and manifested as heat at differing levels. Substantial insulation in a coat limits the thermal impact at the skin of solar radiation, irrespective where in the coat it is absorbed. In coats with low insulation, the zone where solar radiation is absorbed may govern the consequent heat load on the skin (HL-SR). Thin summer furs of four species of kangaroo from differing climatic zones were used to determine how variation in insulation and in coat spectral and structural characteristics influence the HL-SR. Coat depth, structure, and solar reflectance varied between body regions, as well as between species. The modulation of solar radiation and resultant heat flows in these coats were measured at low (1 m s
Publisher: Springer US
Date: 1989
Publisher: Springer Science and Business Media LLC
Date: 08-02-2003
DOI: 10.1007/S00360-002-0319-3
Abstract: Red kangaroos (Macropus rufus) are large (>20 kg) herbivorous marsupials common to the arid and semi-arid regions of inland Australia, where drought is frequent. Young-at-foot (YAF) red kangaroos are the age/size class usually most affected by drought. Kangaroos at this YAF stage are making the transition from a milk-based diet to one of herbivory and an inability to adequately digest high-fibre feeds may contribute to their high mortalities during drought. We examined the role of milk in the nutrition of YAF red kangaroos fed forages of different fibre content and evaluated it as an extra energy and/or nitrogen source. Milk intake had little impact on the digestion of herbage by YAF red kangaroos fed low-fibre chopped lucerne (alfalfa) hay. Organic matter (OM) intake was 210+/-20 g day(-1) and 228+/-22 g day(-1), respectively, by YAF fed lucerne and lucerne with milk. Apparent digestibility of lucerne OM was ca. 55%, regardless of milk intake. Fed lucerne, with and without milk, YAF sustained growth rates of ca. 45 g day(-1). Conversely, even with a milk supplement, YAF red kangaroos ingested only 90+/-11 g day(-1) of high-fibre chopped oaten hay, of which they digested only ca. 36%. Despite milk intake, YAF fed chopped oaten hay lost between 0 and 75 g body mass day(-1) and were in negative nitrogen balance (-0.40+/-0.11 g N day(-1)). On all diets nitrogen loss was primarily as endogenous nitrogen (urinary and faecal) rather than as dietary nitrogen. Endogenous nitrogen losses were elevated in YAF fed chopped oaten hay, primarily as non-dietary faecal nitrogen. Overall, when high-quality feed was available, YAF were not markedly dependent on milk. However, YAF fed poor-quality chopped oaten hay would require up to 540 ml day(-1) of late-stage kangaroo milk to attain intakes of energy and nitrogen, and hence growth rates, comparable with those YAF fed lucerne.
Publisher: Springer Berlin Heidelberg
Date: 1989
Publisher: University of Chicago Press
Date: 1978
Publisher: Wiley
Date: 08-1967
DOI: 10.1038/ICB.1967.42
Abstract: Anthropophilic species ("commensal" species) that are completely dependent upon anthropic habitats experience different selective pressures particularly in terms of food than their noncommensal counterparts. Using a next-generation sequencing approach, we characterized and compared the gut microflora community of 53 commensal
Publisher: Springer Science and Business Media LLC
Date: 1979
DOI: 10.1007/BF00709996
Publisher: Springer Science and Business Media LLC
Date: 05-02-2001
Abstract: The mean corpuscular fragility (MCF) of erythrocytes may reflect phylogenetic characteristics as well as an animal's ability to respond to the osmotic challenges associated with cyclic dehydration and rehydration. This type of ecophysiological stress is commonly encountered by animals living in arid regions and low MCF may contribute to their ability to survive and thrive in these xeric habitats. The eastern grey kangaroo has only in recent times extended its range into the arid zone, and is considered a more mesic inhabitant than the red kangaroo. We therefore compared the ability of eastern grey kangaroos and red kangaroos to handle prolonged periods of water restriction, as well as the MCF of the erythrocytes of free-ranging red, eastern grey and western grey kangaroos found at the Fowlers Gap field station. In addition, the MCF of free-ranging sheep inhabiting the same pastures were used as an experimental control they are phylogenetically unrelated yet are subjected to the same acclimatisation stresses. While red kangaroos exhibited greater tolerance of dehydration compared to eastern grey kangaroos, the MCF of all three kangaroo species was similar and more resilient to osmotic stresses (MCF, 130 mosmol/kg) than erythrocytes of sheep (MCF, 220 mosmol/kg). The MCF did not change with water restriction, however, the erythrocytes of long-term captive populations fed a comparatively better quality diet were more resistant to osmotic shock than the free-ranging animals. Phylogenetic commonality rather than ecophysiological responses to life in the arid zone appeared to influence MCF. The MCF values of sheep corresponded to that of other ovines similarly the MCF of kangaroos concurred regardless of their preferred habitats. ecological history and differential success in the arid zone.
Publisher: Wiley
Date: 09-1989
Publisher: Wiley
Date: 06-1996
Publisher: American Physiological Society
Date: 08-1974
DOI: 10.1152/AJPLEGACY.1974.227.2.494
Abstract: Sphingomyelin is an essential cellular lipid that traffics between plasma membrane and intracellular organelles until directed to lysosomes for SMPD1 (sphingomyelin phosphodiesterase 1)-mediated degradation. Inactivating mutations in the SMPD1 gene result in Niemann-Pick diseases type A and B characterized by sphingomyelin accumulation and severely disturbed tissue homeostasis. Here, we report that sphingomyelin overload disturbs the maturation and closure of autophagic membranes. Niemann-Pick type A patient fibroblasts and SMPD1-depleted cancer cells accumulate elongated and unclosed autophagic membranes as well as abnormally swollen autophagosomes in the absence of normal autophagosomes and autolysosomes. The immature autophagic membranes are rich in WIPI2, ATG16L1 and MAP1LC3B but display reduced association with ATG9A. Contrary to its normal trafficking between plasma membrane, intracellular organelles and autophagic membranes, ATG9A concentrates in transferrin receptor-positive juxtanuclear recycling endosomes in SMPD1-deficient cells. Supporting a causative role for ATG9A mistrafficking in the autophagy defect observed in SMPD1-deficient cells, ectopic ATG9A effectively reverts this phenotype. Exogenous C12-sphingomyelin induces a similar juxtanuclear accumulation of ATG9A and subsequent defect in the maturation of autophagic membranes in healthy cells while the main sphingomyelin metabolite, ceramide, fails to revert the autophagy defective phenotype in SMPD1-deficient cells. Juxtanuclear accumulation of ATG9A and defective autophagy are also evident in tissues of smpd1-deficient mice with a subsequent inability to cope with kidney ischemia-reperfusion stress. These data reveal sphingomyelin as an important regulator of ATG9A trafficking and maturation of early autophagic membranes.
Publisher: Elsevier BV
Date: 1982
Publisher: CSIRO Publishing
Date: 1972
DOI: 10.1071/ZO9720017
Abstract: A study was carried out to examine the effect of posture (standing or lying) on the radiation heat load which would be experienced by a kangaroo resting under a small desert tree during a summer day. Measurements were made to assess the temperature and radiation characteristics in three situations judged to be equivalent to the following: (1) a kangaroo standing in the sun in open country (2) an animal standing in the shade of a small tree (3) an animal lying in the same shade. The overall pattern of results was shown by the effective radiation temperature measurements made at midday: 78.3, 57.6, and 52.5C for positions (I), (2), and (3) respectively. The relative contributions of solar and long-wave infrared radiation to the pattern of results are discussed.
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/AM04161
Abstract: Red kangaroos (Macropus rufus) are large ( 20 kg) herbivorous marsupials common to the arid and semi-arid regions of inland Australia. The population dynamics of M. rufus is tightly linked to environmental factors, which operate partly through the survival of juveniles. A crucial period is the young-at-foot (YAF) stage when juveniles have permanently left the mother?s pouch. YAF and weaned kangaroos have the highest drought-related mortalities of any cohort and show notable differences from adults in their basic physiology. YAF and weaned M. rufus, for ex le, had a resting metabolic rate (kJ kg-1 d-1) twice that of mature females and 1.5 times that expected for an adult marsupial of equivalent body mass (i.e., kJ kg-0.75 d-1). This greater energy turnover was largely explained by their metabolic demands for growth juveniles required 70 - 95% of the digestible energy intake (kJ d-1) of mature, non-lactating females. Meeting these costs may not be a problem for juveniles when high-quality, low-fibre forage is available, but they were constrained when only hard-to-digest, high-fibre forage was available. YAF and weaned kangaroos, for ex le, were unable to sustain growth on forages of more than 40 ? 50% fibre, fibre levels characteristic of forages in arid regions during drought. Yet mature, non-lactating females were capable of maintaining body mass on similar forage. Additionally, juvenile M. rufus required relatively more water than adults for thermoregulation (by up to 2.5-fold), especially under hot conditions, and may need to drink more frequently than adults. Thus, juveniles appear constrained to remain close to water points, increasing their risk of predation and limiting their ability to find the high-quality forage needed for their growth and survival.
Publisher: University of Chicago Press
Date: 07-1981
Publisher: University of Chicago Press
Date: 07-1968
Publisher: Oxford University Press (OUP)
Date: 11-1993
DOI: 10.2307/1369441
Publisher: American Physiological Society
Date: 04-1977
DOI: 10.1152/JAPPL.1977.42.4.636
Abstract: The structure and function of the kidneys of two species of desert kangaroos, the red kangaroo (Megaleia rufa) and the euro (Macropus robustus), were examined. Both kangaroos had glomerular filtration rates (GFR), renal plasma flows, and urine flow rates, when hydrated and dehydrated, which were lower than those of similarly sized eutherian mammals. The differences observed between the two species of marsupials were both structural and functional. The GFR of the red kangaroo was higher than that of the euro, under hydrated and dehydrated conditions, and this was correlated with the occurrence of larger and more numerous glomeruli, particularly juxtamedullary glomeruli, in the red kangaroo. Although the kidney of the euro had a greater relative medullary thickness than that of the red kangaroo, the latter had better urine-concentrating abilities. As opposed to this the euros reabsorbed significantly more urea from the filtrate when dehydrated (89.0%) than did the red kangaroos (69.2%). This ability of the euro to resorb more urea may be related to their tendency to overgraze their restricted home ranges during drought.
Publisher: Springer Science and Business Media LLC
Date: 11-1973
DOI: 10.1038/246313A0
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/AM04169
Abstract: Eastern grey kangaroos (Macropus giganteus) have expanded into arid areas usually the habitat of red kangaroos (Macropus rufus). Extra watering sites for domestic stock is the suggested reason. However, changes in vegetation also have occurred due to grazing from domestic stock. We investigated the foraging strategies of M. giganteus and M. rufus in arid rangeland to see if these are involved in the range changes. Foraging patterns were similar, with both species mostly foraging at night total feeding times were the same. M. giganteus and M. rufus had differing diets, though there was considerable overlap of 81 - 87%. Both species were highly selective, having similar narrow dietary niche breaths. Differences in plant preferences occurred and though both species had a preference for grass that of M. giganteus was higher. A larger foregut in M. giganteus reinforces its focus on grass. M. rufus also selected dicot forbs and malvaceous sub-shrubs. Both kangaroos showed avoidance of abundant chenopod shrubs (saltbushes and bluebushes) and trees. It is likely that the changes to arid-zone vegetation, with a shift to grass and annual dicot forbs, has been important for the expansion of M. giganteus, possibly combined with the greater availability of water.
Publisher: Elsevier BV
Date: 1978
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/ZO08063
Abstract: Sustainable management of pastures requires detailed knowledge of total grazing pressure, but this information is critically lacking in Australia’s rangelands where livestock co-occur with large herbivorous marsupials. We present the first comparative measure of the field metabolic rate (an index of food requirement) of Australia’s largest marsupial, the red kangaroo (Macropus rufus), with that of domestic sheep (Ovis aries merino breed). We tested the assumption that the grazing pressure of red kangaroos is equivalent to 0.7 sheep, and show this to be a two-fold overestimation of their contribution to total grazing. Moreover, kangaroos had extraordinarily lower rates of water turnover, being only 13% that of sheep. Consequently, our data support arguments that the removal of kangaroos may not markedly improve rangeland capacity for domestic stock. Furthermore, given the low resource requirements of kangaroos, their use in consumptive and non-consumptive enterprises can provide additional benefits for Australia’s rangelands than may occur under traditional rangeland practices.
Publisher: Springer Science and Business Media LLC
Date: 08-1977
Publisher: University of Chicago Press
Date: 11-1988
Publisher: CSIRO Publishing
Date: 1962
DOI: 10.1071/BI9620371
Abstract: The influence of haemoglobin type and erythrocyte potassium concentration on oxygen dissociation curves and rate of denaturation of haemoglobin by alkali have been studied in Southdown sheep.
Publisher: Elsevier BV
Date: 09-1989
DOI: 10.1016/0034-5687(89)90119-9
Abstract: Placental and marsupial mammals differ in the balance of their cardio-respiratory systems. To determine if differences also occur in lung structure, a morphometric study of the lungs of a dasyurid marsupial, Dasyuroides byrnei, was undertaken. The total lung volume was large, but a comparatively smaller proportion was devoted to gas exchange tissue. Eighty-seven percent of lung parenchyma was air space. The volume of capillary blood was lower than would be predicted on a body mass basis, but the hematocrit was high (55%). The rate of oxygen uptake by the blood of D. byrnei was not different from that of recent determinations on human blood. However, a large oxygen capacity resulted in a high theta O2. Morphometric data were used, with theta O2 calculated for D. byrnei, to estimate the pulmonary diffusion capacity. Mass specific DLO2 was high by comparison to those reported for placentals. The erythrocytes contributed 70% of the diffusion resistance to oxygen transfer, with the large theta O2 counteracting the low Vc. We conclude that, similarly to placentals, lung structure is unlikely to limit oxygen transport in this animal, although the structural emphasis appears to be geared towards maximising alveolar ventilation.
Publisher: Elsevier BV
Date: 1985
DOI: 10.1016/0300-9629(85)90162-8
Abstract: To determine whether marsupial mammals increase their metabolic capabilities during cold acclimation, the metabolism of both warm and cold acclimated Dasyuroides byrnei was examined by exposure to cold in a helium-oxygen atmosphere. Mean values of heat production and conductance were significantly higher in a helium-oxygen atmosphere than in air. Body temperature did not change until metabolic capacity was exhausted. Both cold and warm acclimated groups could maintain a metabolic scope of 10-11 times the basal or standard level for this species. Such a metabolic scope is much higher than levels recorded for placental mammals. At very low ambient temperatures cold acclimated D. byrnei could sustain a high level of heat production longer than could warm acclimated animals. While there are some similarities between marsupial mammals and placental mammals in their responses to cold acclimation, an increase in maximum metabolism, as reported for placentals, does not seem to occur in marsupials.
Publisher: Royal Zoological Society of New South Wales
Date: 2014
DOI: 10.7882/FS.2007.044
Publisher: Wiley
Date: 02-1966
Abstract: A genetic etiology for autism spectrum disorders (ASDs) was first suggested from twin studies reported in the 1970s. The identification of gene mutations in syndromic ASDs provided evidence to support a genetic cause of ASDs. More recently, genome-wide copy number variant and sequence analyses have uncovered a list of rare and highly penetrant copy number variants (CNVs) or single nucleotide variants (SNVs) associated with ASDs, which has strengthened the claim of a genetic etiology for ASDs. Findings from research studies in the genetics of ASD now support an important role for molecular diagnostics in the clinical genetics evaluation of ASDs. Various molecular diagnostic assays including single gene tests, targeted multiple gene panels and copy number analysis should all be considered in the clinical genetics evaluation of ASDs. Whole exome sequencing could also be considered in selected clinical cases. However, the challenge that remains is to determine the causal role of genetic variants identified through molecular testing. Variable expressivity, pleiotropic effects and incomplete penetrance associated with CNVs and SNVs also present significant challenges for genetic counseling and prenatal diagnosis.
Publisher: American Physiological Society
Date: 09-1965
DOI: 10.1152/AJPLEGACY.1965.209.3.593
Abstract: In domestic sheep there exist two genetically determined types of hemoglobin which have considerably different oxygen affinities. Under most conditions sheep with either of these hemoglobins exist together, apparently sheep with one type being at no gross disadvantage compared to those with the other. Theoretical considerations suggested that the tissues of sheep with the higher oxygen affinity hemoglobin (Hb-A) should be hypoxic relative to those of sheep with the lower oxygen affinity hemoglobin (Hb-B). The data obtained showed that the cardiovascular and respiratory systems of animals with different hemoglobins differed in many respects. It was concluded that the nature of these differences was such that they could be viewed as being due to adjustments by animals with Hb-A to alleviate the potential hypoxia of their tissues relative to the tissues of animals with Hb-B.
Publisher: Wiley
Date: 03-1969
DOI: 10.2307/1934861
Publisher: Springer Science and Business Media LLC
Date: 2014
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/ZO00011
Abstract: The Australian magpie goose (Anseranas semipalmata) is not really a ‘goose’ but an aberrant species representing the monotypic family Anseranatidae. It is herbivorous but its ability to utilise dietary fibre is uncertain. We examined digestive processes in tame birds fed natural forages in metabolism cages and in wild birds. An examination of the gross anatomy of the gut showed features similar to those in waterfowl of the family Anatidae, the true ducks and geese. In a total-collection feeding trial geese were fed either unhusked rice grain or fresh aquatic grass. The aquatic grass was high in fibre (neutral detergent fibre (NDF) was 74% of dry matter) and magpie geese could not maintain energy or nitrogen balance on this feed. The maintenance energy requirement of the caged magpie geese, as estimated on the rice diet, was 573 kJ kg–1 day–1, which was similar to that found for other species of geese. The maintenance nitrogen requirement was 0.44 g N kg–1 day–1 or 0.52 g N kg–0.75 day–1, which also was similar to the average value for birds. Fibre digestion on both diets was small, 19% and 27% of NDF for rice and grass respectively. Rates of passage of fibrous digesta through the gut of magpie geese varied with diet. The mean retention time for fibre was longer when feeding on the aquatic grass than on unhusked grain, 7.7 3.0 h v. 3.7 0.6 h Data from wild magpie geese clarified the process of digestion. The patterns of pH and short-chain fatty acids along the gut pointed to acid and enzymic digestion occurring in most of the tract, down to the ileocaecal junction. Fermentation appeared restricted to the caeca, rectum and cloaca, though, of note, the caeca contained little fibre, 5% NDF. Higher levels of fibre digestion were indicated in wild geese but fibre still was not a major contributor to the energy intake of these birds. The digestive capabilities of the magpie geese were considered in relation to their impact on the feeding and reproductive biology of these ‘geese’ in monsoonal, northern Australia
Publisher: Elsevier BV
Date: 1978
Publisher: Springer Science and Business Media LLC
Date: 2003
Publisher: Elsevier BV
Date: 08-1999
Publisher: Springer Science and Business Media LLC
Date: 07-08-2003
DOI: 10.1007/S00360-003-0364-6
Abstract: The locomotory characteristics of kangaroos and wallabies are unusual, with both energetic costs and gait parameters differing from those of quadrupedal running mammals. The kangaroos and wallabies have an evolutionary history of only around 5 million years their closest relatives, the rat-kangaroos, have a fossil record of more than 26 million years. We examined the locomotory characteristics of a rat-kangaroo, Bettongia penicillata. Locomotory energetics and gait parameters were obtained from animals exercising on a motorised treadmill at speeds from 0.6 m s(-1) to 6.2 m s(-1). Aerobic metabolic costs increased as hopping speed increased, but were significantly different from the costs for a running quadruped at the fastest speed, the cost of hopping was 50% of the cost of running. Therefore B. penicillata can travel much faster than quadrupedal runners at similar levels of aerobic output. The maximum aerobic output of B. penicillata was 17 times its basal metabolism. Increases in speed during hopping were achieved through increases in stride length, with stride frequency remaining constant. We suggest that these unusual locomotory characteristics are a conservative feature among the hopping marsupials, with an evolutionary history of 20-30 million years.
Publisher: The Royal Society
Date: 07-2014
Abstract: When moving slowly, kangaroos plant their tail on the ground in sequence with their front and hind legs. To determine the tail's role in this ‘pentapedal’ gait, we measured the forces the tail exerts on the ground and calculated the mechanical power it generates. We found that the tail is responsible for as much propulsive force as the front and hind legs combined. It also generates almost exclusively positive mechanical power, performing as much mass-specific mechanical work as does a human leg during walking at the same speed. Kangaroos use their muscular tail to support, propel and power their pentapedal gait just like a leg.
Publisher: CSIRO Publishing
Date: 1980
DOI: 10.1071/ZO9800229
Abstract: Body and skin temperatures were recorded from water rats exposed to a range of air temperatures and also immersed in water at various temperatures. They were able to maintain stable core temperatures (mean 36.1�C, SD 0.65, n=61) at air temperatures up to 30�C. At 35�C they were unable to avoid hyperthermia despite their use of saliva spreading to enhance heat loss. Regional heterothermia was observed both in air and in water, but water rats were unable to maintain deep body temperatures at water temperatures lower than 25�C. Variations in the level of activity in cold water affected the rate of heat loss. Examination of the vascular system revealed the presence of various networks adapted for heat loss, but no major heat-conserving vascular retia. It is suggested that the poor thermoregulatory performance of water rats during aquatic excursions is largely due to the lack of heat-conserving retia, and to the poor insulative capacity of the fur when wet. The platypus, which possesses excellent fur insulation and a highly developed heat-conserving system, is a very competent homeotherm in cold water. The behavioural responses displayed by water rats which enable them to exploit the aquatic environment in south-eastern Australia are discussed.
Publisher: Elsevier BV
Date: 02-1974
DOI: 10.1016/0300-9629(74)90024-3
Abstract: Intracellular proton extrusion in gastric cancer cells has been reported to promote cancer cell survival under acidic conditions via hydrogen otassium adenosine triphosphatase (H
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/WR9920079
Abstract: Patterns of dietary selection were examined in the rare bridled nailtail wallaby (Onychogalea fraenata) and compared with those of the black-striped wallaby (Macropus dorsalis) and cattle on the Taunton Scientific Reserve in central Queensland. These two species were considered as possible competitors of 0, fraenata. The dietary niche breadth, the similarity of diet to resources, of 0. fraenata was always narrower than those of the larger species. However, the niche breadths of all species broadened significantly during the driest seasonal conditions, which accounts for the increased dietary overlaps previously reported in these conditions. An analysis of dietary preferences (electivities) showed that 0. fraenata had a high preference for herbaceous plants (forbs and malvaceous species), whereas M. dorsalis and cattle had high preference for grass. During dry conditions the preferred diet of 0. fraenata was considerably different to its actual diet, indicating that the diet was suboptimal. This pattern was not as pronounced in the other herbivores, suggesting that 0. fraenata could be at a competitive disadvantage during these conditions in its last refuge.
Publisher: American Meteorological Society
Date: 11-2011
DOI: 10.1175/JCLI-D-11-00077.1
Abstract: This paper evaluates in a realistic context the local contributions of direct atmospheric forcing and intrinsic oceanic processes on interannual sea level anomalies (SLAs). A ¼° global ocean–sea ice general circulation model, driven over 47 yr by the full range of atmospheric time scales, is quantitatively assessed against altimetry and shown to reproduce most observed features of the interannual SLA variability from 1993 to 2004. Comparing this simulation with a second driven only by the climatological annual cycle reveals that the intrinsic part of the total interannual SLA variance exceeds 40% over half of the open-ocean area and exceeds 80% over one-fifth of it. This intrinsic contribution is particularly strong in eddy-active regions (more than 70%–80% in the Southern Ocean and western boundary current extensions) as predicted by idealized studies, as well as within the 20°–35° latitude bands. The atmosphere directly forces most of the interannual SLA variance at low latitudes and in most midlatitude eastern basins, in particular north of about 40°N in the Pacific. The interannual SLA variance is almost entirely due to intrinsic processes south of the Antarctic Circumpolar Current in the Indian Ocean sector, while half of this variance is forced by the atmosphere north of it. The same simulations were performed and analyzed at 2° resolution as well: switching to this laminar regime yields a comparable forced variability (large-scale distribution and magnitude) but almost suppresses the intrinsic variability. This likely explains why laminar ocean models largely underestimate the interannual SLA variance.
Publisher: Elsevier BV
Date: 09-1993
DOI: 10.1016/0034-5687(93)90076-M
Abstract: Previous studies have indicated that the pattern of respiration in marsupial and placental mammals may be different. Some marsupials have larger tidal volumes and slower respiratory rates under basal conditions. This study examined the respiratory responses of a small marsupial, Dasyuroides byrnei, to increasing metabolic demand. The highest metabolic rate elicited by cold exposure in a helium-oxygen atmosphere was 10.4 times the basal metabolic rate. Basal tidal volumes and respiratory rates were 138% and 46% respectively of the values predicted for placental mammals. The increasing oxygen demands of metabolism were met by increases in ventilation rather than by changes in oxygen extraction. Initially, tidal volume increased until it reached a maximum value 2.6 times that of basal tidal volume. Subsequently, ventilation was augmented by an increase in respiratory frequency. Ventilatory accommodation to an increasing oxygen demand indicated that D. byrnei has an excellent respiratory capacity to deal with the thermogenic demands of a cold environment.
Publisher: Elsevier BV
Date: 02-1974
DOI: 10.1016/0300-9629(74)90026-7
Abstract: Metastasis to the breast from an extramammary malignant neoplasm, including esthesioneuroblastoma, is uncommon. The present study describes a rare case of sinonasal esthesioneuroblastoma, Hyams' histologic grade 2, Kadish's stage C, T4N0M0, in a 30-year-old female. The patient underwent a radical ethmoidectomy with external beam radiotherapy, followed by chemotherapy including five cycles of cisplatin and etoposide. One year after the initial diagnosis, the patient presented to the hospital with the chief complaint of a rapidly enlarging lump in the right breast. A fine needle aspiration was performed and immunocytochemistry revealed a metastatic esthesioneuroblastoma. The patient received palliative chemotherapy and radiotherapy however, the patient developed a local recurrence with systemic metastasis and succumbed to the disease seven months later.
Publisher: Elsevier BV
Date: 09-1973
DOI: 10.1016/0300-9629(73)90568-9
Abstract: The Australian Pharmaceutical Advisory Committee guidelines call for a detailed medication history to be taken at the first point of admission to an Emergency Department (ED). The elderly, in particular those residing in Residential Aged Care Facilities and those with a non-English speaking background, have been identified as patient groups vulnerable to medication misadventure. to analyse the incidence of discrepancies in medication histories in these demographic groups when pharmacist elicited medication histories were compared with those taken by ED physicians. It also aimed to investigate the incidence of medication related ED presentations. The study was conducted over a six week period and included 100 patients over the age of 70, who take five or more regular medications, have three or more clinical co-morbidities and/or have been discharged from hospital in three months prior to the study. Twenty four participants were classified as 'language barrier' 12 participants were from residential aged care facilities, and 64 participants were classified as 'general'. The number of correctly recorded medications was lowest in the 'language barrier' group (13.8%) compared with 18% and 19.6% of medications for 'general' patients and patients from residential aged care facilities respectively. Seven of the patients (29.2%) with 'language barrier' 1 from a residential aged care facility (8.3%) and 13 of the (20.3%) patients from the 'general' category were suspected as having a medication related ED presentation. This study further highlights the positive contribution an ED pharmacist can make to enhancing medication management along the continuum of care. This study also confirms the vulnerability of patients with language barrier to medication misadventure and their need for interpreter services at all stages of their hospitalisation, in particular at the point of ED presentation.
Publisher: University of Chicago Press
Date: 03-2006
DOI: 10.1086/499980
Abstract: Red kangaroos (Macropus rufus) are large (>20 kg) herbivorous marsupials common to arid and semiarid Australia. The population dynamics of red kangaroos are linked with environmental factors, operating largely through juvenile survival. A crucial period is the young-at-foot (YAF) stage, when juveniles have permanently left the mother's pouch but still take milk from a teat in the pouch. Forage quantity and quality have been implicated in drought-related mortalities of juvenile kangaroos. Here we compared how forage quality affected nitrogen (N) intake and excretion by YAF, weaned, and mature, nonlactating female red kangaroos. On high-quality forage (chopped lucerne hay, Medicago sativa) low in neutral-detergent fiber (43%+/-1%) and high in N (2.9%+/-0.1%), YAF and weaned kangaroos had ideal growth rates and retained 460-570 mg dietary N kg(-0.75) d(-1). But on poor-quality forage (chopped oaten hay, Avena sativa) high in neutral-detergent fiber (64%+/-1%) and low in N (0.9%+/-0.1%), YAF and weaned kangaroos could not sustain growth and were in negative N balance at -103+/-26 mg and -57+/-31 mg N kg(-0.75) d(-1), respectively. Notably, the YAF kangaroos excreted 64% of their truly digestible N intake from forage as nondietary fecal N (NDFN). By weaning age, the situation had improved, but the juveniles still lost 40% of their truly digestible N intake as NDFN compared with only 30% by the mature females. Our findings support field observations that forage quality, and not just quantity, is a major factor affecting the mortality of juvenile red kangaroos during drought.
Publisher: Elsevier BV
Date: 08-1999
Publisher: Springer Science and Business Media LLC
Date: 05-1991
DOI: 10.1007/BF00262881
Publisher: University of Chicago Press
Date: 03-2019
DOI: 10.1086/515997
Abstract: When exposed to high ambient temperatures, birds defend body temperature by increasing evaporative water loss, via either respiratory or cutaneous water loss. Water deprivation can lead to changes in thermal responses and lower levels of water use for thermoregulation. We have studied the effect of 2-3 wk of water deprivation on the physiological responses of emus during exposure to an ambient temperature of 45 degrees C. Water deprivation led to a delay in the onset of panting (54 vs. 24 min after start of exposure) and to higher body temperatures (38.7 degrees vs. 38.3 degrees C) at the end of exposure to 45 degrees C. After panting was initiated and body temperature stabilised, the water-deprived emus had a lower total evaporative water loss (77 vs. 101 g/h), the same respiratory water loss (70 vs. 72 g/h), and a lower cutaneous water loss (7 vs. 29 g/h) than they did when hydrated. The factor contributing most to the lower total evaporative water loss in the dehydrated emus was a 47% reduction in dry thermal conductance, which led to a decrease in the exogenous environmental heat load and therefore the level of evaporation needed to defend body temperature. We suggest that the decrease in dry thermal conductance follows from the lower level of cutaneous water loss.
Publisher: Wiley
Date: 06-2006
Publisher: Wiley
Date: 06-1966
Abstract: To evaluate the effect of crowd-figure-pictograms on women's numeric knowledge about mammography screening in a three-armed parallel randomised controlled trial. 552 women were randomised to receive (1) non-numeric information (n = 192), (2) non-numeric and numeric information (n = 186), or (3) non-numeric and numeric information complemented by crowd-figure-pictograms (n = 174). Baseline numeric knowledge was low (control 0.61, numeric 0.66, and pictogram 0.51 on a scale ranging from 0 to 5). Women in the crowd-figure-pictogram group had a larger knowledge increase than women in the numeric group (2.42 vs 2.06, p = .03). Both groups had significant increases in knowledge compared to the control (0.20, p < .001). Providing numeric information in absolute numbers improves knowledge even more so when crowd-figure-pictograms are added. Trial registration German Clinical Trials Register DRKS00014736, retrospectively registered 11 May 2018.
Publisher: American Physiological Society
Date: 09-1980
DOI: 10.1152/AJPREGU.1980.239.3.R285
Abstract: The lower intestine (coprodeum and colon) of the Australian parrot, the galah, was mounted in Ussing chambers. Short-circuit current (SCC), electrical potential difference (PD), and unidirectional fluxes of Na and Cl were measured in birds that were fed mixed seeds or were NaCl loaded. The net Na transport of both coprodeum and colon was nearly equal to the SCC, and the flux ratio for Cl was unity. In birds which received mixed seeds, average coprodeal Na transport was 7.8 mu eq . cm-2 . h-1, and PD was 19 mV. The Km for Na was 5.7 meq/l. In colon, Na transport was reduced by 67% and PD by 70%. The ratio between unidirectional Na and Cl fluxes in the serosa-mucosa direction was 0.7. Salt loading suppressed coprodeal, but increased colonic Na transport. The coprodeal and colonic SCC and NA transport of birds receiving mixed seeds were inhibited by amiloride on the mucosal side. Colonic SCC of NaCl-loaded birds was only slightly reduced by amiloride (by 17%), but stimulated by amino acids (by 18%).
Publisher: Elsevier BV
Date: 11-1970
Publisher: Springer Science and Business Media LLC
Date: 1969
DOI: 10.1038/221383A0
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/WR9930785
Abstract: The effects of temporal (time of day and season) factors and size, sex, female reproductive state and group size on the diel time-use of free-ranging red kangaroos (Macropus rufus) was examined. Particular emphasis was given to the effects on their foraging behaviour, with foraging ided into cropping, chewing and searching components. The study was conducted in semi-arid western New South Wales from July 1991 to March 1992, a time of deepening drought conditions in New South Wales. Group size had very little influence on the time-use of M. rufus. It was negatively but only weakly correlated with the proportion of foraging time spent chewing (chewing intensity). No significant differences in time-use were found between size classes of adult males (large and medium-sized males), females with or without pouch young, or females with different-sized pouch young (no visible young, small pouch young or large pouch young). Differences occurred between adult males, adult females and subadult kangaroos. These differences were mainly associated with their chewing and searching behaviour and were related to body size as body size increased the proportion of time spent chewing and the intensity of chewing increased while the proportion of time searching and the proportion of foraging time spent searching (searching intensity) decreased. Neither the proportion of time spent cropping or foraging nor the proportion of foraging time spent cropping (cropping intensity) or the proportion of active time spent foraging (foraging intensity) differed between any size/sex/reproductive class. Temporal effects had a considerable influence on time-use. M. rufus were most active at night and in the few hours after sunrise and sunset. Seasonal changes in time-use were largely a result of changes in daytime behaviour. M. rufus foraged less and rested more during the day in winter than in spring or summer. There was no increase in the intensity or proportion of time spent foraging or cropping at night to compensate for the reduction in diurnal foraging. It is hypothesised that temporal variations in time-use were related to variations in weather and vegetation conditions.
No related grants have been discovered for Terence Dawson.