ORCID Profile
0000-0003-2595-9114
Current Organisation
University of Queensland
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Astronomical and Space Sciences | Stellar Astronomy and Planetary Systems | Astronomical and Space Instrumentation | Astronomical sciences | Stellar astronomy and planetary systems | Machine learning not elsewhere classified | Astrobiology | Optical technology | Image Processing |
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Engineering | Scientific Instruments | Expanding Knowledge in the Information and Computing Sciences |
Publisher: American Astronomical Society
Date: 17-09-2019
Publisher: Oxford University Press (OUP)
Date: 12-10-2020
Abstract: The recent discovery of a spectacular dust plume in the system 2XMM J160050.7–514245 (referred to as ‘Apep’) suggested a physical origin in a colliding-wind binary by way of the ‘Pinwheel’ mechanism. Observational data pointed to a hierarchical triple-star system, however, several extreme and unexpected physical properties seem to defy the established physics of such objects. Most notably, a stark discrepancy was found in the observed outflow speed of the gas as measured spectroscopically in the line-of-sight direction compared to the proper motion expansion of the dust in the sky plane. This enigmatic behaviour arises at the wind base within the central Wolf–Rayet binary: a system that has so far remained spatially unresolved. Here, we present an updated proper motion study deriving the expansion speed of Apep’s dust plume over a 2-year baseline that is four times slower than the spectroscopic wind speed, confirming and strengthening the previous finding. We also present the results from high angular resolution near-infrared imaging studies of the heart of the system, revealing a close binary with properties matching a Wolf–Rayet colliding-wind system. Based on these new observational constraints, an improved geometric model is presented yielding a close match to the data, constraining the orbital parameters of the Wolf–Rayet binary and lending further support to the anisotropic wind model.
Publisher: American Astronomical Society
Date: 09-2021
Publisher: American Astronomical Society
Date: 27-09-2018
Publisher: Oxford University Press (OUP)
Date: 05-09-2016
Publisher: Science Alert
Date: 15-06-2012
DOI: 10.3923/PJBS.2012.850.853
Abstract: Phylogeny and evolutionary analyses were performed for Jordan goat breeds based on DNA sequencing. DNA segment of 0.5-kb from sixteen goat in iduals of four breeds was sequenced. The DNA sequencing was analyzed by both Arlequin and MEGA softwares. The results showed a quite evolutionary differentiation found within goat breeds between. Furthermore, phylogeny tree was reconstructed providing evidences for a close phylogenetic alliance among breeds. The resulted evolutionary sequencing and phylogeny trees provide evidences that sequencing data were worthy to describe the evolutionary and phylogeny genetics in goats breeds in Jordan. On other hand the data were given scopes for possible sequences of gene(s) and identify polymorphisms, given possibility to identify Caprine genes from other close species genome like cattle. In the future we intend, in order to clearly identify the genetic polymorphisms, to detect further genetic variation and to develop tests particularly suitable for specific interested genes genotyping.
Publisher: Informa UK Limited
Date: 2013
Publisher: IOP Publishing
Date: 2023
Abstract: The James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (JWST-NIRISS) flies a 7-hole non-redundant mask (NRM), the first such interferometer in space, operating at 3–5 μ m wavelengths, and a bright limit of ≃4 mag in W2. We describe the NIRISS Aperture Masking Interferometry (AMI) mode to help potential observers understand its underlying principles, present some s le science cases, explain its operational observing strategies, indicate how AMI proposals can be developed with data simulations, and how AMI data can be analyzed. We also present key results from commissioning AMI. Since the allied Kernel Phase Imaging (KPI) technique benefits from AMI operational strategies, we also cover NIRISS KPI methods and analysis techniques, including a new user-friendly KPI pipeline. The NIRISS KPI bright limit is ≃8 W2 (4.6 μ m) magnitudes. AMI NRM and KPI achieve an inner working angle of ∼70 mas, which is well inside the ∼400 mas NIRCam inner working angle for its circular occulter coronagraphs at comparable wavelengths.
Publisher: Elsevier BV
Date: 08-2009
Publisher: American Astronomical Society
Date: 22-10-2021
Publisher: Oxford University Press (OUP)
Date: 17-11-2015
Publisher: Oxford University Press (OUP)
Date: 11-08-2017
Publisher: Oxford University Press (OUP)
Date: 30-05-2013
DOI: 10.1093/MNRAS/STT802
Publisher: Genetics and Molecular Research
Date: 2015
Publisher: Oxford University Press (OUP)
Date: 08-03-2014
DOI: 10.1093/MNRAS/STU218
Publisher: Science Alert
Date: 15-08-2009
Publisher: The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS
Date: 29-06-2021
DOI: 10.3906/VET-2010-15
Publisher: Elsevier BV
Date: 09-2019
Publisher: The Open Journal
Date: 22-03-2023
DOI: 10.21105/JOSS.05084
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856770
Publisher: Oxford University Press (OUP)
Date: 08-06-2016
Publisher: American Astronomical Society
Date: 17-11-2015
Publisher: American Astronomical Society
Date: 21-08-2020
Abstract: We present the serendipitous discovery of a low optical-luminosity nova occurring in a D-type symbiotic binary star system in the Milky Way. We lay out the extensive archival data alongside new follow-up observations related to the stellar object CN Cha in the constellation of Chamaeleon. The object had long period (250 days), high litude (3 mag) optical variability in its recent past, preceding an increase in optical brightness by 8 magnitudes and a persistence at this brightness for about 3 yr, followed by a period of 1.4 mag yr −1 dimming. The object’s current optical luminosity seems to be dominated by H α emission, which also exhibits blueshifted absorption (a P-Cygni-like profile). After consideration of a number of theories to explain these myriad observations, we determine that CN Cha is most likely a symbiotic (an evolved-star–white-dwarf binary) system that has undergone a long-duration, low optical brightness, nova, placing it squarely in the class of so-called “slow novae,” of which there are only a few known ex les. The duration of the optical plateau in CN Cha would make it the shortest timescale plateau of any known slow symbiotic novae.
Publisher: Genetics and Molecular Research
Date: 2017
DOI: 10.4238/GMR16039701
Publisher: The Open Journal
Date: 10-07-2020
DOI: 10.21105/JOSS.02125
Publisher: Springer Science and Business Media LLC
Date: 25-07-2017
DOI: 10.1007/S11356-017-9808-5
Abstract: The objective of the current study was to investigate the effect of corn distiller's dried grains with solubles (DDGS) and enzyme supplementation on growth performance and carcass yield in broiler chickens. The experiment was a 5 × 3 factorial design with 450 broiler chickens and with diets containing five levels of DDGS (0, 6, 12, 18, and 24%) and three levels of the enzymes (no supplementation, Rovabio® enzyme, and Tomoko® enzyme). Five pens with six chicks were fed an experimental diet from 0 to 35 days of age. Diets containing 12, 18, and 24% DDGS decreased performance (P < 0.05) at the start of the trial at 0-10 days. Inclusion of enzyme during 0-10 days improved body weight gain (BWG) and European production efficiency factor (EPEF) (P < 0.05). During the grower (11-24 days) and finisher (25-35 days) periods, chickens which had received 0, 6, or 12% DDGS converted feed to body weight more efficiently (P < 0.05). Enzyme supplementation improved feed conversion ratio (FCR) for the periods (11-24 and 25-35 days, respectively) (P < 0.05). The cumulative performance results (0 to 35 days of age) showed that Tomoko enzyme improved FCR as compared to no enzyme while Rovabio was intermediate (P < 0.05). Chickens which had received 0, 6, or 12% had better FCR (P < 0.05) compared to 18 or 24% DDGS. Chick's performance was depressed at early age when the diet contained 12% DDGS but later, they were able to tolerate higher levels of DDGS. The study indicate that a maximum level of DDGS to use in the starter diets is 6% and it could be increased in the grower and finisher period to 12% and enzyme supplementation to diets containing DDGS can improve FCR and growth performance in broilers.
Publisher: Cambridge University Press (CUP)
Date: 17-08-2015
DOI: 10.1017/S0007485315000668
Abstract: Aphids are important agricultural pests worldwide. Their control is largely based on chemical insecticides. One species that shows important invasive abilities and host-plant-related differences is Therioaphis trifolii (Monell) (Hemiptera: Aphididae). T. trifolii maculata , also known as spotted alfalfa aphid (SAA), can be very injurious to alfalfa crops in certain regions, such as in Saudi Arabia for effective control it is essential to diagnose and monitor the resistance mechanisms in the SAA populations. In the present study, we analysed acetylcholinesterase ( ace ) target site insensitivity mechanisms. A 650 bp length DNA containing the putative acetylcholinesterase ( ace1 ) precursor was obtained and compared with other Hemipteran species. The sequences of many in idual aphids collected from alfalfa crops in Saudi Arabia were analysed for the presence of resistance mutations: no resistance mutations were found at the resistance mutation loci 302 however, the presence of a serine–phenylalanine substitution (S431F) was identified in one in idual. The S431F substitution, has been shown to confer significant levels of both organophosphate and carbamate resistance in other aphid species, and is now found for the first time in T. trifolii . We subsequently developed a simple polymerase chain reaction–restriction fragment length polymorphism assays for the S431F mutation, using a TaqI restriction site destroyed by the S431F mutation. The novel diagnostic assay may support the implementation of Insecticide Resistance Management strategies, for the control of SAA in alfalfa crops in the Kingdom of Saudi Arabia, and other countries worldwide.
Publisher: Oxford University Press (OUP)
Date: 05-01-2019
Publisher: FapUNIFESP (SciELO)
Date: 03-2017
Publisher: Springer Science and Business Media LLC
Date: 26-01-2021
Publisher: American Astronomical Society
Date: 17-02-2020
Publisher: American Astronomical Society
Date: 19-10-2021
Publisher: FapUNIFESP (SciELO)
Date: 10-2017
Publisher: Springer Science and Business Media LLC
Date: 06-2019
DOI: 10.1007/S11250-019-01948-5
Abstract: We investigated the thermotolerance of the F1 progeny (Black Bedouin × Damascus crossbreed) to summer conditions alongside that of two pure breeds. Male goats (n = 7 per breed) were used to conduct a summertime 28-day trial along with hypohydration. The animals were fitted with miniscule thermologgers, intraperitoneally and subcutaneously, to measure core (T
Publisher: Elsevier BV
Date: 07-2016
Publisher: American Astronomical Society
Date: 07-10-2019
Publisher: Springer Science and Business Media LLC
Date: 08-2022
DOI: 10.1007/S11207-022-02037-X
Abstract: Severe geomagnetic storms appear to be ordered by the solar cycle in a number of ways. They occur more frequently close to solar maximum and the declining phase, are more common in larger solar cycles, and show different patterns of occurrence in odd- and even-numbered solar cycles. Our knowledge of the most extreme space-weather events, however, comes from spikes in cosmogenic-isotope ( 14 C, 10 Be, and 36 Cl) records that are attributed to significantly larger solar energetic-particle (SEP) events than have been observed during the space age. Despite both storms and SEPs being driven by solar-eruptive phenomena, the event-by-event correspondence between extreme storms and extreme SEPs is low. Thus, it should not be assumed a priori that the solar-cycle patterns found for storms also hold for SEPs and the cosmogenic-isotope events. In this study, we investigate the solar-cycle trends in the timing and magnitude of the 67 SEP ground-level enhancements (GLEs) recorded by neutron monitors since the mid-1950s. Using a number of models of GLE-occurrence probability, we show that GLEs are around a factor of four more likely around solar maximum than around solar minimum, and that they preferentially occur earlier in even-numbered solar cycles than in odd-numbered cycles. There are insufficient data to conclusively determine whether larger solar cycles produce more GLEs. Implications for putative space-weather events in the cosmogenic-isotope records are discussed. We find that GLEs tend to cluster within a few tens of days, likely due to particularly productive in idual active regions, and with approximately 11-year separations, owing to the solar-cycle ordering. However, these timescales would not explain any cosmogenic-isotope spikes requiring multiple extreme SEP events over consecutive years.
Publisher: American Astronomical Society
Date: 2021
Abstract: The accumulation of aberrations along the optical path in a telescope produces distortions and speckles in the resulting images, limiting the performance of cameras at high angular resolution. It is important to achieve the highest possible sensitivity to faint sources, using both hardware and data analysis software. While analytic methods are efficient, real systems are better modeled numerically, but numerical models of complicated optical systems with many parameters can be hard to understand, optimize, and apply. Automatic differentiation or “backpropagation” software developed for machine-learning applications now makes calculating derivatives with respect to aberrations in arbitrary planes straightforward for any optical system. We apply this powerful new tool to the problem of high-angular-resolution astronomical imaging. Self-calibrating observables such as the “closure phase” or “bispectrum” have been widely used in optical and radio astronomy to mitigate optical aberrations and achieve high-fidelity imagery. Kernel phases are a generalization of closure phases valid in the limit of small phase errors. Using automatic differentiation, we reproduce existing kernel phase theory within this framework and demonstrate an extension to the case of a Lyot coronagraph, which is found to have self-calibrating combinations of speckles. which are resistant to phase noise, but only in the very high-wave-front-quality regime. As an illustrative ex le, we reanalyze Palomar adaptive optics observations of the binary α Ophiuchi, finding consistency between the new pipeline and the existing standard. We present a new Python package morphine that incorporates these ideas, with an interface similar to the popular package poppy , for optical simulation with automatic differentiation. These methods may be useful for designing improved astronomical optical systems by gradient descent.
Publisher: Informa UK Limited
Date: 2013
Publisher: Elsevier BV
Date: 07-2014
Publisher: Springer Science and Business Media LLC
Date: 11-10-2021
Publisher: Springer Science and Business Media LLC
Date: 17-02-2020
Publisher: Springer Science and Business Media LLC
Date: 19-11-2018
Publisher: Oxford University Press (OUP)
Date: 06-10-2016
Publisher: American Astronomical Society
Date: 04-10-2019
Publisher: American Astronomical Society
Date: 04-2023
Abstract: We report the discovery of the first brown dwarf binary system with a Y dwarf primary, WISE J033605.05−014350.4, observed with NIRCam on JWST with the F150W and F480M filters. We employed an empirical point-spread function binary model to identify the companion, located at a projected separation of 0.″084, position angle of 295°, and with contrasts of 2.8 and 1.8 mag in F150W and F480M, respectively. At a distance of 10 pc based on its Spitzer parallax, and assuming a random inclination distribution, the physical separation is approximately 1 au. Evolutionary models predict for that an age of 1–5 Gyr, the companion mass is about 4–12.5 Jupiter masses around the 7.5–20 Jupiter mass primary, corresponding to a companion-to-host mass fraction of q = 0.61 ± 0.05. Under the assumption of a Keplerian orbit the period for this extreme binary is in the range of 5–9 yr. The system joins a small but growing s le of ultracool dwarf binaries with effective temperatures of a few hundreds of Kelvin. Brown dwarf binaries lie at the nexus of importance for understanding the formation mechanisms of these elusive objects, as they allow us to investigate whether the companions formed as stars or as planets in a disk around the primary.
Publisher: Elsevier BV
Date: 09-2015
Publisher: American Astronomical Society
Date: 10-04-2020
Publisher: Science Alert
Date: 15-07-2017
DOI: 10.3923/PJBS.2017.372.381
Abstract: Intestinal bacteria plays an important role in the physiological and immunological status of birds. The present study investigated the ersity of intestinal bacterial of broilers that were fed corn-soy diet and supplements of antibiotics and probiotics. The supplemented treatments were water, water with antibiotics, water with probiotic and water with antibiotics and probiotic. Eight randomly s led broilers were slaughtered and their ileum digesta taken. The total of 32 s les was then subjected for DNA extraction. Subsequently, bacterial tag-encoded 16 FLX liconpyro sequencing (bTEFAP) procedures were performed. Nearly all treatments s les contained Lactobacillus, with the majority related to water with probiotic treatment. In contrast, different pathogenic bacteria along with Lactobacillus observed for other three treatments. The probiotics supplements made a shift towards useful bacterial species Lactobacillus salivarius and Lactobacillus aviarius. This study promoted for replacing the probiotics as a prophylaxis in gastrointestinal infection and diseases instead of antibiotics.
Publisher: American Astronomical Society
Date: 02-04-2013
Publisher: Springer Science and Business Media LLC
Date: 27-02-2016
DOI: 10.1007/S11250-015-0990-5
Abstract: The meat productivity of camel in the tropics is still under investigation for identification of better meat breed or type. Therefore, four one-humped Saudi Arabian (SA) camel breeds, Majaheem, Maghateer, Hamrah, and Safrah were experimented in order to differentiate them from each other based on meat measurements. The measurements were biometrical meat traits measured on six intact males from each breed. The results showed higher values of the Majaheem breed than that obtained for the other breeds except few cases such dressing percentage and rib-eye area. In differentiation analysis, the most discriminating meat variables were myofibrillar protein index, meat color components (L* and a*, b*), and cooking loss. Consequently, the Safrah and the Majaheem breeds presented the largest dissimilarity as evidenced by their multivariate means. The canonical discriminant analysis allowed an additional understanding of the differentiation between breeds. Furthermore, two large clusters, one formed by Hamrah and Maghateer in one group along with Safrah. These classifications may assign each breed into one cluster considering they are better as meat producers. The Majaheem was clustered alone in another cluster that might be a result of being better as milk producers. Nevertheless, the productivity type of the camel breeds of SA needs further morphology and genetic descriptions.
Publisher: The Royal Society
Date: 10-2022
Abstract: Annually resolved measurements of the radiocarbon content in tree-rings have revealed rare sharp rises in carbon-14 production. These ‘Miyake events’ are likely produced by rare increases in cosmic radiation from the Sun or other energetic astrophysical sources. The radiocarbon produced is not only circulated through the Earth’s atmosphere and oceans, but also absorbed by the biosphere and locked in the annual growth rings of trees. To interpret high-resolution tree-ring radiocarbon measurements therefore necessitates modelling the entire global carbon cycle. Here, we introduce ‘ ticktack ’ ( github.com/SharmaLlama/ticktack/ ), the first open-source Python package that connects box models of the carbon cycle with modern Bayesian inference tools. We use this to analyse all public annual 14 C tree data, and infer posterior parameters for all six known Miyake events. They do not show a consistent relationship to the solar cycle, and several display extended durations that challenge either astrophysical or geophysical models.
Publisher: Springer Science and Business Media LLC
Date: 06-05-2019
Publisher: SPIE
Date: 02-08-2014
DOI: 10.1117/12.2056639
Publisher: American Astronomical Society
Date: 24-03-2017
Abstract: We report the discovery of a repeating photometric signal from a low-mass member of the Praesepe open cluster that we interpret as a Neptune-sized transiting planet. The star is JS 183 (HSHJ 163, EPIC 211916756), with T eff = 3325 ± 100 K, M * = 0.44 ± 0.04 M ⊙ , R * = 0.44 ± 0.03 R ⊙ , and . The planet has an orbital period of 10.134588 days and a radius of R P = 0.32 ± 0.02 R J . Since the star is faint at V = 16.5 and J = 13.3, we are unable to obtain a measured radial velocity orbit, but we can constrain the companion mass to below about 1.7 M J , and thus well below the planetary boundary. JS 183b (since designated as K2-95b) is the second transiting planet found with K2 that resides in a several-hundred-megayear open cluster both planets orbit mid-M dwarf stars and are approximately Neptune sized. With a well-determined stellar density from the planetary transit, and with an independently known metallicity from its cluster membership, JS 183 provides a particularly valuable test of stellar models at the fully convective boundary. We find that JS 183 is the lowest-density transit host known at the fully convective boundary, and that its very low density is consistent with current models of stars just above the fully convective boundary but in tension with the models just below the fully convective boundary.
Publisher: Cambridge University Press (CUP)
Date: 08-2016
DOI: 10.1017/RDC.2016.50
Abstract: Single-year spikes in radiocarbon production are caused by intense bursts of radiation from space. Supernovae emit both high-energy particle and electromagnetic radiation, but it is the latter that is most likely to strike the atmosphere all at once and cause a surge in 14 C production. In the 1990s, it was claimed that the supernova in 1006 CE produced exactly this effect. With the 14 C spikes in the years 775 and 994 CE now attributed to extreme solar events, attention has returned to the question of whether historical supernovae are indeed detectable using annual 14 C measurements. Here, we combine new and existing measurements over six documented and putative supernovae, and conclude that no such astrophysical event has yet left a distinct imprint on the past atmospheric 14 C record.
Publisher: Elsevier BV
Date: 2013
Publisher: The Royal Society
Date: 08-2022
Abstract: The discovery of past spikes in atmospheric radiocarbon activity, caused by major solar energetic particle events, has opened up new possibilities for high-precision chronometry. The two spikes, or Miyake Events, have now been widely identified in tree-rings that grew in the years 775 and 994 CE. Furthermore, all other plant material that grew in these years would also have incorporated the anomalously high concentrations of radiocarbon. Crucially, some plant-based artefacts, such as papyrus documents, timber beams and linen garments, can also be allocated to specific positions within long, currently unfixed, historical sequences. Thus, Miyake Events represent a new source of tie-points that could provide the means for anchoring early chronologies to the absolute timescale. Here, we explore this possibility, outlining the most expeditious approaches, the current challenges and obstacles, and how they might best be overcome.
Publisher: Elsevier BV
Date: 06-2009
Publisher: Genetics and Molecular Research
Date: 2014
Publisher: Elsevier BV
Date: 03-2016
Publisher: American Astronomical Society
Date: 11-2019
Publisher: American Astronomical Society
Date: 18-11-2019
Publisher: Springer Science and Business Media LLC
Date: 14-03-2020
DOI: 10.1186/S12863-020-0830-0
Abstract: Indigenous domestic chicken represents a major source of protein for agricultural communities around the world. In the Middle East and Africa, they are adapted to hot dry and semi-dry areas, in contrast to their wild ancestor, the Red junglefowl, which lives in humid and sub-humid tropical areas. Indigenous populations are declining following increased demand for poultry meat and eggs, favouring the more productive exotic commercial breeds. In this paper, using the D -loop of mitochondrial DNA as a maternally inherited genetic marker, we address the question of the origin and dispersal routes of domestic chicken of the Middle East (Iraq and Saudi Arabia), the northern part of the African continent (Algeria and Libya) and the Horn of Africa (Ethiopia). The analysis of the mtDNA D -loop of 706 chicken s les from Iraq ( n = 107), Saudi Arabia ( n = 185), Algeria ( n = 88), Libya ( n = 23), Ethiopia ( n = 211) and Pakistan ( n = 92) show the presence of five haplogroups (A, B, C, D and E), suggesting more than one maternal origin for the studied populations. Haplogroup E, which occurred in 625 s les, was the most frequent in all countries. This haplogroup most likely originates from the Indian subcontinent and probably migrated following a terrestrial route to these different countries. Haplotypes belonging to haplogroup D were present in all countries except Algeria and Libya, it is likely a legacy of the Indian Ocean maritime trading network. Haplogroup A was present in all countries and may be of commercial origin. Haplogroup B was found only in Ethiopia. Haplogroup C was only detected in the South-Western region of Saudi Arabia and in Ethiopia. The results support a major influence of the Indian subcontinent on the maternal ersity of the today’s chicken populations examined here. Most of the ersity occurs within rather than between populations. This lack of phylogeographic signal agrees with both ancient and more recent trading networks having shaped the modern-day ersity of indigenous chicken across populations and countries.
Publisher: Springer Science and Business Media LLC
Date: 12-02-2020
DOI: 10.1186/S12915-020-0738-1
Abstract: Hybridisation and introgression play key roles in the evolutionary history of animal species. They are commonly observed within several orders in wild birds. The domestic chicken Gallus gallus domesticus is the most common livestock species. More than 65 billion chickens are raised annually to produce meat and 80 million metric tons of egg for global human consumption by the commercial sector. Unravelling the origin of its genetic ersity has major application for sustainable breeding improvement programmes. In this study, we report genome-wide analyses for signatures of introgression between indigenous domestic village chicken and the four wild Gallus species. We first assess the genome-wide phylogeny and ergence time across the genus Gallus . Genome-wide sequence ergence analysis supports a sister relationship between the Grey junglefowl G. sonneratii and Ceylon junglefowl G. lafayettii . Both species form a clade that is sister to the Red junglefowl G. gallus , with the Green junglefowl G. varius the most ancient lineage within the genus. We reveal extensive bidirectional introgression between the Grey junglefowl and the domestic chicken and to a much lesser extent with the Ceylon junglefowl. We identify a single case of Green junglefowl introgression. These introgressed regions include genes with biological functions related to development and immune system. Our study shows that while the Red junglefowl is the main ancestral species, introgressive hybridisation episodes have impacted the genome and contributed to the ersity of the domestic chicken, although likely at different levels across its geographic range.
Publisher: Veterinary World
Date: 22-11-2022
DOI: 10.14202/VETWORLD.2022.2665-2672
Abstract: Background and Aim: The multivariate discriminant (MVD) analysis was a successful statistical tool with a discriminatory capacity for tracing sheep breeds based on meat characteristics. Thus, this study aimed to identify three Saudi sheep breeds based on the physical and histochemical aspects of meat using MVD analysis. Materials and Methods: Eight male lambs from each breed, Najdi, Neami, and Harri, were selected randomly at 90 days of age and allocated into three groups for breeding in a completely randomized design. The feeding and rearing management were similar for an experimental period of 90 days. The experimental diet consisted of a concentrated mixture with identical amounts of calories and nitrogen. Fifty-one meat characteristics were measured in the preliminary MVD, representing hot and cold carcass weight, meat cuts and quality measures, body component weights, fat deposit weights, and histochemical characteristics. Results: Out of the total meat characteristics measured, only 19 characteristics had significant discriminant power. The most powerful characteristics were temperature, empty intestinal weight, pH24, external carcass length, heart weight, and L1, based on partial R-square and Wilks' lambda values. The phenotypic associations between the characteristics had strong associations. The obtained principal components efficiently classified the eight in iduals of each breed into distinct groups using robust discriminant characteristics. Conclusion: This method allowed us to determine the breed of sheep carcasses and cuts by considering the physical characteristics of the meat. Therefore, butchers and consumers should use scientific techniques for assigning carcasses and meat to their sheep breed after slaughtering.
Publisher: Oxford University Press (OUP)
Date: 2020
Abstract: Infrared imaging of the colliding-wind binary Apep has revealed a spectacular dust plume with complicated internal dynamics that challenges standard colliding-wind binary physics. Such challenges can be potentially resolved if a rapidly rotating Wolf–Rayet star is located at the heart of the system, implicating Apep as a Galactic progenitor system to long-duration gamma-ray bursts. One of the difficulties in interpreting the dynamics of Apep is that the spectral composition of the stars in the system was unclear. Here, we present visual to near-infrared spectra that demonstrate that the central component of Apep is composed of two classical Wolf–Rayet stars of carbon- (WC8) and nitrogen-sequence (WN4-6b) subtypes. We argue that such an assignment represents the strongest case of a classical Wolf–Rayet+Wolf–Rayet binary system in the Milky Way. The terminal line-of-sight wind velocities of the WC8 and WN4-6b stars are measured to be 2100 ± 200 and 3500 ± 100 km s−1, respectively. If the mass-loss rate of the two stars are typical for their spectral class, the momentum ratio of the colliding winds is expected to be ≈0.4. Since the expansion velocity of the dust plume is significantly smaller than either of the measured terminal velocities, we explore the suggestion that one of the Wolf–Rayet winds is anisotropic. We can recover a shock-compressed wind velocity consistent with the observed dust expansion velocity if the WC8 star produces a significantly slow equatorial wind with a velocity of ≈530 km s−1. Such slow wind speeds can be driven by near-critical rotation of a Wolf–Rayet star.
Publisher: American Astronomical Society
Date: 29-09-2021
Publisher: FapUNIFESP (SciELO)
Date: 2022
Publisher: Elsevier BV
Date: 12-2017
Publisher: EDP Sciences
Date: 04-2021
DOI: 10.1051/0004-6361/202039144
Abstract: Recently detected coherent low-frequency radio emission from M dwarf systems shares phenomenological similarities with emission produced by magnetospheric processes from the gas giant planets of our Solar System. Such beamed electron-cyclotron maser emission can be driven by a star-planet interaction or a breakdown in co-rotation between a rotating plasma disk and a stellar magnetosphere. Both models suggest that the radio emission could be periodic. Here we present the longest low-frequency interferometric monitoring c aign of an M dwarf system, composed of twenty-one ≈8 h epochs taken in two series of observing blocks separated by a year. We achieved a total on-source time of 6.5 days. We show that the M dwarf binary CR Draconis has a low-frequency 3 σ detection rate of 90 −8 +5 % when a noise floor of ≈0.1 mJy is reached, with a median flux density of 0.92 mJy, consistent circularly polarised handedness, and a median circularly polarised fraction of 66%. We resolve three bright radio bursts in dynamic spectra, revealing the brightest is elliptically polarised, confined to 4 MHz of bandwidth centred on 170 MHz, and reaches a flux density of 205 mJy. The burst structure is mottled, indicating it consists of unresolved sub-bursts. Such a structure shares a striking resemblance with the low-frequency emission from Jupiter. We suggest the near-constant detection of high brightness temperature, highly-circularly-polarised radiation that has a consistent circular polarisation handedness implies the emission is produced via the electron-cyclotron maser instability. Optical photometric data reveal the system has a rotation period of 1.984 ± 0.003 days. We observe no periodicity in the radio data, but the s ling of our radio observations produces a window function that would hide the near two-day signal.
Publisher: SPIE
Date: 21-07-2014
DOI: 10.1117/12.2055334
Publisher: Science Alert
Date: 15-04-2012
Publisher: Frontiers Media SA
Date: 20-07-2018
Publisher: Springer Science and Business Media LLC
Date: 15-05-2017
DOI: 10.1007/S11356-017-9130-2
Abstract: Distiller's dried grains with solubles (DDGS) is a source of nutritional feedstuff for poultry farmers and industry. The DDGS is a by-product of ethanol industry and an economical feed source of energy, amino acids, crude fiber, minerals, and vitamins. The use of DDGS as a feed ingredient is a novel idea and little information is available on its dietary composition. Many factors such as the type of plants, locality, year of production, and the conditions during distillation process affect the chemical composition of DDGS. In this paper, the chemical composition and the presence of mycotoxin in DDGS imported from the USA into Saudi Arabia as a feedstuff for poultry have been documented.
Publisher: Oxford University Press (OUP)
Date: 12-04-2016
DOI: 10.1093/MNRAS/STW706
Publisher: American Astronomical Society
Date: 22-02-2019
Publisher: EDP Sciences
Date: 02-2019
DOI: 10.1051/0004-6361/201834690
Abstract: Context . Asteroseismic analysis of solar-like stars allows us to determine physical parameters such as stellar mass, with a higher precision compared to most other methods. Even in a well-studied cluster such as the Hyades, the masses of the red giant stars are not well known, and previous mass estimates are based on model calculations (isochrones). The four known red giants in the Hyades are assumed to be clump (core-helium-burning) stars based on their positions in colour-magnitude diagrams, however asteroseismology offers an opportunity to test this assumption. Aims . Using asteroseismic techniques combined with other methods, we aim to derive physical parameters and the evolutionary stage for the planet hosting star ϵ Tau, which is one of the four red giants located in the Hyades. Methods . We analysed time-series data from both ground and space to perform the asteroseismic analysis. By combining high signal-to-noise radial-velocity data from the ground-based SONG network with continuous space-based data from the revised Kepler mission K2, we derive and characterize 27 in idual oscillation modes for ϵ Tau, along with global oscillation parameters such as the large frequency separation Δ ν and the ratio between the litude of the oscillations measured in radial velocity and intensity as a function of frequency. The latter has been measured previously for only two stars, the Sun and Procyon. Combining the seismic analysis with interferometric and spectroscopic measurements, we derive physical parameters for ϵ Tau, and discuss its evolutionary status. Results . Along with other physical parameters, we derive an asteroseismic mass for ϵ Tau of M = 2.458 ± 0.073 M ⊙ , which is slightly lower than previous estimates, and which leads to a revised minimum mass of the planetary companion. Noting that the SONG and K2 data are non-simultaneous, we estimate the litude ratio between intensity and radial velocity to be 42.2 ± 2.3 ppm m −1 s, which is higher than expected from scaling relations.
Publisher: Genetics and Molecular Research
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 19-11-2019
DOI: 10.1038/S41598-019-53296-X
Abstract: Extreme cosmic radiation events occurred in the years 774/5 and 993/4 CE, as revealed by anomalies in the concentration of radiocarbon in known-age tree-rings. Most hypotheses point towards intense solar storms as the cause for these events, although little direct experimental support for this claim has thus far come to light. In this study, we perform very high-precision accelerator mass spectrometry (AMS) measurements on dendrochronological tree-rings spanning the years of the events of interest, as well as the Carrington Event of 1859 CE, which is recognized as an extreme solar storm even though it did not generate an anomalous radiocarbon signature. Our data, comprising 169 new and previously published measurements, appear to delineate the modulation of radiocarbon production due to the Schwabe (11-year) solar cycle. Moreover, they suggest that all three events occurred around the maximum of the solar cycle, adding experimental support for a common solar origin.
Publisher: Springer Science and Business Media LLC
Date: 03-08-2017
DOI: 10.1007/S00253-017-8448-5
Abstract: With the increasing production of ethanol for biofuels, a by-product of corn-based ethanol fermentation, dried distillers grains with solubles (DDGS) is finding its way into the feed of agricultural animals including cattle, pigs, poultry, sheep, goats, aquaculture species and horses. Corn DDGS contains very high levels of non-starch polysaccharides and could be considered a good source of fibre. Despite knowledge of the role of the fibre in modulating intestinal microbiota and consequently influencing health, there is currently little information on the interactions between DDGS and intestinal microbiota. We assessed the changes in the cecal microbiota of broilers feed rations supplemented with DDGS (five concentrations: 0, 6, 12, 18 and 24% w/w) with and without presence of digestive enzymes. DDGS concentration was strongly positively correlated (P = 3.7e
Location: United Kingdom of Great Britain and Northern Ireland
Location: United States of America
Start Date: 04-2023
End Date: 04-2026
Amount: $885,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 12-2022
End Date: 12-2023
Amount: $296,339.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2023
End Date: 07-2026
Amount: $390,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2021
End Date: 12-2024
Amount: $444,075.00
Funder: Australian Research Council
View Funded Activity