Andrew Robinson

Description and test of a simple process-based model of forest growth for mixed-species stands

Publisher: Elsevier BV

Date: 05-2007

DOI: 10.1016/J.ECOLMODEL.2006.11.032

Sudden and sustained response of Acacia koa crop trees to crown release in stagnant stands

Publisher: Canadian Science Publishing

Date: 04-2008

DOI: 10.1139/X07-137

Abstract: We examined the growth response of Acacia koa Gray (koa) in dense (10 000 trees/ha), ~25-year-old, second-growth stands on Hawai‘i to crown release (thinning) and grass control. Koa diameter increment increased within 2 months of thinning across the range of residual densities (200–900 trees/ha). After 3 years, diameter increment in the most intense thinning treatment was 180% greater than in the control treatment (1.4 vs. 0.5 cm/year) in the least intense thinning treatment diameter increment was 100% greater than the control (1.0 vs. 0.5 cm/year). Koa’s growth response was independent of all measures of tree size (diameter at breast height, height, and leaf area) across the range of tree sizes s led. A grass control treatment to determine if reduced competition for soil water would improve koa growth showed no improvement in growth response. Koa phyllode δ 13 C values, which represent an integrated measure of tree water status, showed no evidence of tree water stress (mean δ 13 C = –28.3‰) and were not significantly different between the grass removal and control treatments. These results demonstrate that koa is capable of responding quickly and positively to crown release despite years of suppressed growth and suggest that landowners interested in managing koa forests may have considerable flexibility in the timing and application of thinning treatments to koa stands.

Spectroscopic Investigation on the Effects of Biochar and Soluble Phosphorus on Grass Clipping Vermicomposting

Publisher: MDPI AG

Date: 13-07-2022

DOI: 10.3390/AGRICULTURE12071011

Abstract: Seeking to evaluate the hypothesis that biochar optimises the composting and vermicomposting processes as well as their product quality, we carried out field and greenhouse experiments. Four grass clipping composting treatments (only grass, grass + single superphosphate (SSP), grass + biochar and grass + SSP + biochar) were evaluated. At the end of the maturation period (150 days), the composts were submitted to vermicomposting (Eisenia fetida earthworm) for an additional 90 days. Ordinary fine charcoal was selected due to its low cost (a by-product of charcoal production) and great availability this is important since the obtained product presents low commercial value. A greater maturity of the organic matter (humification) was observed in the vermicompost treatments compared with the compost-only treatments. The addition of phosphate significantly reduced the pH (from 6.7 to 4.8), doubled the electrical conductivity and inhibited biological activity, resulting in less than 2% of the number of earthworms found in the treatment without phosphate. The addition of soluble phosphate inhibited the humification process, resulting in a less-stable compound with the preservation of labile structures, primarily cellulose. The P species found corroborate these findings because the pyrophosphate conversion from SSP in the absence of biochar may explain the strong acidification and increased electric conductivity. Biochar appears to prevent this conversion, thus mitigating the deleterious effects of SSP and favouring the formation of organic P species from SSP (78.5% of P in organic form with biochar compared to only 12.8% in the treatments without biochar). In short, biochar decreases pyrophosphate formation from SSP, avoiding acidification and salinity therefore, biochar improves the whole composting and vermicomposting process and product quality. Vermicompost with SSP and biochar should be tested as a soil conditioner on account of its greater proportion of stabilized C and organic P.

Improving decisions for invasive species management: reformulation and extensions of the Panetta-Lawes eradication graph

Publisher: Wiley

Date: 05-2013

DOI: 10.1111/DDI.12055

An alternative objective function for fitting regression trees to functional response variables

Publisher: Elsevier BV

Date: 09-2011

DOI: 10.1016/J.CSDA.2011.03.020

Phosphorus speciation in the fertosphere of highly concentrated fertilizer bands

Publisher: Elsevier BV

Date: 12-2021

DOI: 10.1016/J.GEODERMA.2021.115208

Quantifying stem growth loss at the tree-level in a Pinus radiata plantation to repeated attack by the aphid, Essigella californica

Publisher: Elsevier BV

Date: 2011

DOI: 10.1016/J.FORECO.2010.09.039

Studies of the Compositions of Humic Acids from Amazonian Dark Earth Soils

Publisher: American Chemical Society (ACS)

Date: 08-12-2006

DOI: 10.1021/ES060941X

Abstract: The compositions of humic acids (HAs) isolated from cultivated and forested "Terra Preta de Indio" or Amazonian Dark Earth soils (anthropogenic soils) were compared with those from adjacent non-anthropogenic soils (control soils) using elemental and thermogravimetric analyses, and a variety of solid-state nuclear magnetic resonance techniques. The thermogravimetric index, which indicates the molecular thermal resistance, was greater for the anthropogenic soils than for the control soils suggesting polycyclic aromatic components in the former. The cultivated anthropogenic soils were more enriched in C and depleted in H than the anthropogenic soils under forest, as the result of the selective degradation of aliphatic structures and the possible enrichment of H-deficient condensed aromatic structures. The combination of variable litude cross-polarization (VACP) and chemical shift anisotropy with total suppression of spinning sidebands experiments with composite pi pulses could be used to quantify the aromaticity of the HAs from the anthropogenic soils. From principal component analysis, using the VACP spectra, it was possible to separate the different constituents of the HAs, such as the carboxylated aromatic structures, from the anthropogenic soils and plant derived compounds. The data show that the HAs from anthropogenic soils have high contents of aryl and ionisable oxygenated functional groups, and the major functionalities from adjacent control soils are oxygenated functional groups from labile structures (carbohydrates, peptides, and with evidence for lignin structures). The anthropogenic soils HAs can be considered to be more recalcitrant, and with more stable reactive functional groups which may, in part, explain their more sustainable fertility due to the organic matter contribution to the soil cation exchange capacity.

Chemotherapy for Late-Stage Cancer Patients: Meta-Analysis of Complete Response Rates

Publisher: F1000 Research Ltd

Date: 13-07-2015

DOI: 10.12688/F1000RESEARCH.6760.1

Abstract: Complete response (CR) rates reported for cytotoxic chemotherapy for late-stage cancer patients are generally low, with few exceptions, regardless of the solid cancer type or drug regimen. We investigated CR rates reported in the literature for clinical trials using chemotherapy alone, across a wide range of tumour types and chemotherapeutic regimens, to determine an overall CR rate for late-stage cancers. A total of 141 reports were located using the PubMed database. A meta-analysis was performed of reported CR from 68 chemotherapy trials (total 2732 patients) using standard agents across late-stage solid cancers—a binomial model with random effects was adopted. Mean CR rates were compared for different cancer types, and for chemotherapeutic agents with different mechanisms of action, using a logistic regression. Our results showed that the CR rates for chemotherapy treatment of late-stage cancer were generally low at 7.4%, regardless of the cancer type or drug regimen used. We found no evidence that CR rates differed between different chemotherapy drug types, but amongst different cancer types small CR differences were evident, although none exceeded a mean CR rate of 11%. This remarkable concordance of CR rates regardless of cancer or therapy type remains currently unexplained, and motivates further investigation.

A Novel Spore Collection Device for Sampling Exposure Pathways: A Case Study of Puccinia psidii

Publisher: Scientific Societies

Date: 06-2013

DOI: 10.1094/PDIS-06-12-0565-RE

Abstract: A device comprising a filter attached to a vacuum cleaner was purpose-built to s le rust spores from three potentially high-risk pathways in Australia: passengers, fresh flowers, and sea cargo. The proportion of spores recovered from eight surfaces comparable with those on each pathway (cotton, denim, roses, carnations, chrysanthemums, wood, plastic, and metal) was estimated in the laboratory. Spore recovery percentages were highest for denim clothing (61% Puccinia triticina Erikss. and 62% Uromycladium tepperianum) and lowest for carnations (4% P. triticina Erikss. and 5% U. tepperianum). Subsequently, the device was tested at several locations on the Central Coast of New South Wales, Australia, recently affected by a “myrtle rust” outbreak. Symptomatic and asymptomatic myrtle rust hosts, myrtle rust nonhosts, and inanimate objects (e.g., clothing and vehicles) were s led in conjunction with the emergency response to the outbreak. A polymerase chain reaction (PCR) assay developed for P. psidii established the presence of myrtle rust, and visual inspections provided spore count estimations. All s les from symptomatic myrtle rust hosts produced positive PCR results and spore count estimations were generally much greater. Several s les from asymptomatic myrtle rust hosts, myrtle rust nonhosts, and inanimate objects also produced positive PCR results however, there were discrepancies between PCR results and spore count estimations in some of these s les, all of which had spores. This study highlights the utility of the device and analytical methodology, especially during the early stages of a disease outbreak when infection symptoms on plants and contamination on objects is not visible upon gross examination.

Interval-Based Hypothesis Testing and Its Applications to Economics and Finance

Publisher: MDPI AG

Date: 15-05-2019

DOI: 10.3390/ECONOMETRICS7020021

Abstract: This paper presents a brief review of interval-based hypothesis testing, widely used in bio-statistics, medical science, and psychology, namely, tests for minimum-effect, equivalence, and non-inferiority. We present the methods in the contexts of a one-s le t-test and a test for linear restrictions in a regression. We present applications in testing for market efficiency, validity of asset-pricing models, and persistence of economic time series. We argue that, from the point of view of economics and finance, interval-based hypothesis testing provides more sensible inferential outcomes than those based on point-null hypothesis. We propose that interval-based tests be routinely employed in empirical research in business, as an alternative to point null hypothesis testing, especially in the new era of big data.

Indigenous Australian household structure: a simple data collection tool and implications for close contact transmission of communicable diseases

Publisher: PeerJ

Date: 13-06-2017

DOI: 10.7287/PEERJ.PREPRINTS.3022V1

Abstract: Households are an important location for the transmission of communicable diseases. Social contact between household members is typically more frequent, of greater intensity, and is more likely to involve people of different age groups than contact occurring in the general community. Understanding household structure in different populations is therefore fundamental to explaining patterns of disease transmission in these populations. Indigenous populations in Australia tend to live in larger households than non Indigenous populations, but limited data is available on the structure of these households, and how they differ between remote and urban communities. We have developed a novel approach to the collection of household structure data, suitable for use in a variety of contexts, which provides a detailed view of age,gender, and room occupancy patterns in remote and urban Australian Indigenous households. Here we report analysis of data collected using this tool, which quantifies the extent of crowding in Indigenous households, particularly in remote areas. We use this data to generate matrices of age-specific contact rates, as used by mathematical models of infectious disease transmission. To demonstrate the impact of household structure, we use a mathematical model to simulate an influenza-like illness in different populations. Our simulations suggest that outbreaks in remote populations are likely to spread more rapidly and to a greater extent than outbreaks in non-Indigenous populations.

Leaf area index inferred from solar beam transmission in mixed conifer forests on complex terrain

Publisher: Elsevier BV

Date: 09-2003

DOI: 10.1016/S0168-1923(03)00109-6

Bias in the mean tree model as a consequence of Jensen’s inequality

Publisher: Elsevier BV

Date: 12-2003

DOI: 10.1016/S0378-1127(03)00307-4

Improved data efficiency for NMR diffusion-relaxation processing

Publisher: Elsevier BV

Date: 02-2022

DOI: 10.1016/J.JMR.2021.107124

Abstract: Two dimensional diffusion and transverse (T

A new method for measuring stand sapwood area in forests

Publisher: Wiley

Date: 29-06-2014

DOI: 10.1002/ECO.1520

Extracting LiDAR indices to characterise multilayered forest structure using mixture distribution functions

Publisher: Elsevier BV

Date: 15-02-2011

DOI: 10.1016/J.RSE.2010.10.003

A field experiment characterizing variable detection rates during plant surveys

Publisher: Wiley

Date: 31-01-2022

DOI: 10.1111/COBI.13888

Abstract: Surveys aimed at finding threatened and invasive species can be challenging due to in idual rarity and low and variable in idual detection rates. Detection rate in plant surveys typically varies due to differences among observers, among the in idual plants being surveyed (targets), and across background environments. Interactions among these 3 components may occur but are rarely estimated due to limited replication and control during data collection. We conducted an experiment to investigate sources of variation in detection of 2 Pilosella species that are invasive and sparsely distributed in the Alpine National Park, Australia. These species are superficially similar in appearance to other yellow‐flowered plants occurring in this landscape. We controlled the presence and color of flowers on target Pilosella plants and controlled their placement in plots, which were selected for their variation in cover of non‐target yellow flowers and dominant vegetation type. Observers mimicked Pilosella surveys in the plots and reported 1 categorical and 4 quantitative indicators of their survey experience level. We applied survival analysis to detection data to model the influence of both controlled and uncontrolled variables on detection rate. Orange‐ and yellow‐flowering Pilosella in grass‐ and heath‐dominated vegetation were detected at a higher rate than nonflowering Pilosella . However, this detection gain diminished as the cover of other co‐occurring yellow‐flowering species increased. Recent experience with Pilosella surveys improved detection rate. Detection experiments are a direct and accessible means of understanding detection processes and interpreting survey data for threatened and invasive species. Our detection findings have been used for survey planning and can inform progress toward eradication. Interaction of target and background characteristics determined detection rate, which enhanced predictions in the Pilosella eradication program and demonstrated the difficulty of transferring detection findings into untested environments.

The functional regression tree method for diameter distribution modelling

Publisher: Canadian Science Publishing

Date: 09-2010

DOI: 10.1139/X10-119

Abstract: Forest stand diameter distributions adopt a wide variety of shapes, not all of which can be easily matched by specific functional forms. Sometimes, diameter distributions within a single population can be too variable to be matched by a single parametric family. Motivated by this observation, we investigate the functional regression tree (FRT) method, a recursive partitioning procedure that can be used for modelling probability density functions. We use FRT to estimate forest stand diameter distributions without needing to make assumptions about the functional form. We use an ex le study to demonstrate the effectiveness of the approach in which we compare the FRT method with a parameter prediction and percentile method with favourable results. We show the FRT approach to be suitable for diameter distributions that exhibit multimodality and excess skewness, which are not easily dealt with in a parametric context.

Properties of black soil humic acids from high altitude rocky complexes in Brazil

Publisher: Elsevier BV

Date: 07-2005

DOI: 10.1016/J.GEODERMA.2004.11.020

CRP identifies homeostatic immune oscillations in cancer patients: a potential treatment targeting tool?

Publisher: Springer Science and Business Media LLC

Date: 30-11-2009

DOI: 10.1186/1479-5876-7-102

Fitting forestry models using generalized additive models: a taper model example

Publisher: Canadian Science Publishing

Date: 10-2011

DOI: 10.1139/X11-095

Abstract: Nonparametric and semiparametric modelling methods are commonly applied in many fields. However, such methods have not been widely adopted in forestry, other than the most similar neighbour and nearest neighbor methods. Generalized additive modelling is a flexible semiparametric regression method that is useful when model-based prediction is the main goal and the parametric form of the model is unknown and possibly complex. Routines to fit generalized additive models (GAMs) are now readily available in much statistical software, making them an attractive option for forest modelling. Here, the use of GAMs is demonstrated by the construction of a taper model for six tree species in British Columbia, Canada. We compare the results with an existing flexible parametric taper model. We assess the performance of the models using the 0.632+ bootstrap method according to five key attributes: whole-stem volume, merchantable volume, number of logs, small-end diameter of the first log, and volume of the first log. The results show that the GAMs and the flexible taper function yielded similar accuracy for all attributes and all species.

Soil Carbon and Microbial Processes in Agriculture Ecosystem

Publisher: MDPI AG

Date: 09-09-2023

DOI: 10.3390/AGRICULTURE13091785

Spectroscopy Characterization of Humic Acids Isolated from Amazonian Dark Earth Soils (Terra Preta De Índio)

Publisher: Springer Netherlands

Date: 2009

DOI: 10.1007/978-1-4020-9031-8_20

Allocating surveillance resources to reduce ecological invasions: maximizing detections and information about the threat

Publisher: Wiley

Date: 06-2011

DOI: 10.1890/10-0195.1

Abstract: Allocating resources to detect invasive pests, diseases, and pathogens on exposure pathways requires a trade-off between the need to detect as many contaminated items as possible and the need to acquire knowledge about contamination rates. We develop a model and an algorithm that provide guidance for the allocation of inspection resources across multiple dynamic pathways in cases where not every item can be inspected. The model uses a null hypothesis that the contamination rate of a pathway is above a specified level: a risk cutoff. Pathways with a risk above the cutoff are fully inspected, and those with a risk below the cutoff level are monitored at a rate that would detect a change of the risk to being above the cutoff level with high probability. We base our decision on the 95% upper confidence limit for the contamination rate. We demonstrate via simulations and a data set that focusing inspection resources on specific pathways can result in substantially more effective intervention, and that the reduction in overall effectiveness of monitoring low-risk pathways need not be substantial. Use of the model demands the selection of the risk cutoff, and this limit can be set according to projected consequences.

Risk factors for fouling biomass: evidence from small vessels in Australia

Publisher: Informa UK Limited

Date: 21-10-2018

DOI: 10.1080/08927014.2018.1536202

Abstract: Invasive non-indigenous species (NIS) are a threat to marine bio ersity and marine reliant industries. Recreational vessels are recognised as an important vector of NIS translocation, particularly domestically. This paper reports on a novel application of multilevel modelling and multiple imputation in order to quantify the relationship between biofouling biomass (wet weight) and the vessel-level characteristics of recreational and fishing vessels. It was found that the number of days since the vessel was last cleaned strongly related to the biofouling biomass, yet differed dependent on vessel type. Similarly, the median number of trips undertaken was related to the biofouling biomass, and varied according to the type of antifouling paint (AF) used. No relationship was found between vessel size and biofouling biomass per s le unit. To reduce the spread of NIS, vessel owners should use an AF paint suitable to their vessel's operational profile, and follow a maintenance schedule according to the paint manufacturer's specifications.

Universidade De São Paulo

Location: Brazil

View Organisation

Embrapa Solos

Location: Brazil

View Organisation

Universidade De São Paulo Instituto De Física De São Carlos

Location: Brazil

View Organisation

University Of Limerick

Location: Ireland

View Organisation

Discovery Projects - Grant ID: DP110103159

Start Date: 2011

End Date: 12-2014

Amount: $255,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP160100745

Start Date: 06-2016

End Date: 12-2020

Amount: $350,600.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0772068

Start Date: 2008

End Date: 12-2010

Amount: $180,000.00

Funder: Australian Research Council

Fast Statistical Methods For Enigmatic Sensor Data

Start Date: 2024

End Date: 2027

Funder: Marsden Fund

Discovery Projects - Grant ID: DP0986404

Start Date: 06-2009

End Date: 06-2016

Amount: $987,440.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP140100580

Start Date: 02-2015

End Date: 06-2018

Amount: $415,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP220103711

Start Date: 05-2022

End Date: 05-2025

Amount: $642,000.00

Funder: Australian Research Council

Inference For Statistical Linear Inverse Problems: Theory And Practice

Start Date: 2021

End Date: 2024

Funder: Marsden Fund

Discovery Projects - Grant ID: DP220101495

Start Date: 08-2022

End Date: 07-2025

Amount: $525,000.00

Funder: Australian Research Council