Distinctive diets of eutherian predators in Australia.

Introduction of the domestic cat and red fox has devastated Australian native fauna. We synthesized Australian diet analyses to identify traits of prey species in cat, fox and dingo diets, which prey were more frequent or distinctive to the diet of each predator, and quantified dietary overlap. Nearly half (45%) of all Australian terrestrial mammal, bird and reptile species occurred in the diets of one or more predators. Cat and dingo diets overlapped least (0.64 ± 0.27, n = 24 location/time points) and cat diet changed little over 55 years of study. Cats were more likely to have eaten birds, reptiles and small mammals than foxes or dingoes. Dingo diet remained constant over 53 years and constituted the largest mammal, bird and reptile prey species, including more macropods/potoroids, wombats, monotremes and bandicoots/bilbies than cats or foxes. Fox diet had greater overlap with both cats (0.79 ± 0.20, n = 37) and dingoes (0.73 ± 0.21, n = 42), fewer distinctive items (plant material, possums/gliders) and significant spatial and temporal heterogeneity over 69 years, suggesting the opportunity for prey switching (especially of mammal prey) to mitigate competition. Our study reinforced concerns about mesopredator impacts upon scarce/threatened species and the need to control foxes and cats for fauna conservation. However, extensive dietary overlap and opportunism, as well as low incidence of mesopredators in dingo diets, precluded resolution of the debate about possible dingo suppression of foxes and cats.

Quantifying human post-mortem movement resultant from decomposition processes.

BACKGROUND: Post-mortem movement is highly significant in unexplained death investigations, as body position or the position of remains helps to determine cause and manner of death, as well as potentially the circumstances surrounding death. Therefore, understanding post-mortem movement is of forensic relevance in death scene assessments. PURPOSE: The aim of this study was to quantify post-mortem movement in anatomical structures of a human donor during decomposition in an Australian environment, an evaluation that has not previously been undertaken. METHODS: The aim was achieved using time-lapse images of a human donor decomposing in order to capture the post-mortem movement over a 16-month period. Megyesi et al.'s [1] total body score system was used to quantify the decomposition of the donor in each image to determine the decomposition stage. ImageJ software was used to determine the distance from static landmarks to anatomical structures of interest in each image to allow for quantification. RESULTS: Early decomposition progressed rapidly, and advanced decomposition plateaued at 41 post-mortem interval days with a total body score of 24. The results support the conclusion that post-mortem movement does occur in all limbs of the donor. The anatomical structure that produced the most movement was the right styloid process of the radius, moving a total distance of 51.65 cm. A surprising finding of the study was that most post-mortem movement occurs in the advanced decomposition stage, with the lower limbs being the most active. CONCLUSION: This study supports that post-mortem movement can be quantified using time-lapse imagery, with results supporting movement in all limbs, a process that was active for the entire study period. An interesting finding was that the decomposition plateaued in the advanced stage with the donor remaining in mummification, and not reaching skeletonization after 16 months in situ. These findings are of significant importance to police in death scene assessments and forensic investigations.

Bayesian statistical models for community annoyance survey data.

This paper demonstrates the use of two Bayesian statistical models to analyze single-event sonic boom exposure and human annoyance data from community response surveys. Each model is fit to data from a NASA pilot study. Unlike many community noise surveys, this study used a panel sample to collect multiple observations per participant instead of a single observation. Thus, a multilevel (also known as hierarchical or mixed-effects) model is used to account for the within-subject correlation in the panel sample data. This paper describes a multilevel logistic regression model and a multilevel ordinal regression model. The paper also proposes a method for calculating a summary dose-response curve from the multilevel models that represents the population. The two models' summary dose-response curves are visually similar. However, their estimates differ when calculating the noise dose at a fixed percent highly annoyed.

Evaluating the utility of time-lapse imaging in the estimation of post-mortem interval: An Australian case study.

Estimating post-mortem interval is an important aspect in forensic investigations. The aim of this study was to investigate if time-lapse imaging can be used to improve estimates of post-mortem interval using Megyesi et al.'s [1] method for a human donor decomposing in an Australian environment. To achieve this, time-lapse images were taken every 30 min over a 6-month period. The Megyesi et al. [1] total body score (TBS) system was used to quantify the level of decomposition of the donor for each image. Linear regression was performed to determine if observing decomposition more than once a day leads to increased accuracy in predicting PMI (post-mortem interval). Decomposition initially progressed quickly and then plateaued at 1004 hours PMI, with a TBS of 24. Individual timestamps were created from the time-lapse images taken each day at 08:00 hrs, 11:00 hrs, 14:00 hrs, 15:00 hrs, and 17:00 hrs. All timestamps produced R2 values > 0.80, indicating that the Megyesi et al. [1] method accurately predicts PMI for this donor. The 08:00 hrs timestamp had the highest value R2 = 0.886, whilst the combined timestamp (which included the scores from all five images for each 24-hour period) R2 = 0.823 was the lowest. This study supports the validity of Megyesi et al.'s [1] TBS model to estimate PMI. Two other interesting findings were that the results suggest that scoring TBS multiple times per day does not improve estimates of PMI, however scoring TBS at daybreak produces more accurate results than scoring TBS later in the day. This may be an important consideration in forensic scenarios.

The role of cellular contact and TGF-beta signaling in the activation of the epithelial mesenchymal transition (EMT).

The epithelial mesenchymal transition (EMT) is one step in the process through which carcinoma cells metastasize by gaining the cellular mobility associated with mesenchymal cells. This work examines the dual influence of the TGF-ß pathway and intercellular contact on the activation of EMT in colon (SW480) and breast (MCF7) carcinoma cells. While the SW480 population revealed an intermediate state between the epithelial and mesenchymal states, the MC7 cells exhibited highly adhesive behavior. However, for both cell lines, an exogenous TGF-ß signal and a reduction in cellular confluence can push a subgroup of the population towards the mesenchymal phenotype. Together, these results highlight that, while EMT is induced by the synergy of multiple signals, this activation varies across cell types.

Retention and promotion of women and underrepresented minority faculty in science and engineering at four large land grant institutions.

RESULTS BY GENDER: In the most recent cohort, 2002-2015, the experiences of men and women differed substantially among STEM disciplines. Female assistant professors were more likely than men to leave the institution and to leave without tenure in engineering, but not in the agricultural, biological and biomedical sciences and natural resources or physical and mathematical sciences. In contrast, the median times to promotion from associate to full professor were similar for women and men in engineering and the physical and mathematical sciences, but one to two years longer for women than men in the agricultural, biological and biomedical sciences and natural resources. RESULTS FOR UNDERREPRESENTED MINORITY FACULTY: URM faculty hiring is increasing, but is well below the proportions earning doctoral degrees in STEM disciplines. The results are variable and because of the small numbers of URM faculty, the precision and power for comparing URM faculty to other faculty were low. In three of the four institutions, lower fractions of URM faculty than other faculty hired in the 2002-2006 time frame left without tenure. Also, in the biological and biomedical and physical and mathematical sciences no URM faculty left without tenure. On the other hand, at two of the institutions, significantly more URM faculty left before their tenth anniversary than other faculty and in engineering significantly more URM faculty than other faculty left before their tenth anniversary. We did not find significant differences in promotion patterns between URM and other faculty.

A Theoretical Model of the Wnt Signaling Pathway in the Epithelial Mesenchymal Transition.

BACKGROUND: Following the formation of a primary carcinoma, neoplastic cells metastasize by undergoing the epithelial mesenchymal transition (EMT), which is triggered by cues from inflammatory and stromal cells in the microenvironment. EMT allows epithelial cells to lose their highly adhesive nature and instead adopt the spindle-like appearance, as well as the invasive and migratory behavior, of mesenchymal cells. We hypothesize that a bistable switch between the epithelial and mesenchymal phenotypes governs EMT, allowing the cell to maintain its mesenchymal phenotype even after it leaves the primary tumor microenvironment and EMT-inducing extracellular signal. RESULTS: This work presents a simple mathematical model of EMT, specifically the roles played by four key proteins in the Wnt signaling pathway: Dishevelled (Dvl), E-cadherin, ß-catenin, and Slug. The model predicts that following activation of the Wnt pathway, an epithelial cell in the primary carcinoma must attain a threshold level of membrane-bound Dvl to convert to the mesenchymal-like phenotype and maintain that phenotype once it has migrated away from the primary tumor. Furthermore, sensitivity analysis of the model suggests that in both the epithelial and the mesenchymal states, the steady state behavior of E-cadherin and the transcription factor Slug are sensitive to changes in the degradation rate of Slug, while E-cadherin is also sensitive to the IC50 (half-maximal) concentration of Slug necessary to inhibit E-cadherin production. The steady state behavior of Slug exhibits sensitivity to changes in the rate at which it is induced by ß-catenin upon activation of the Wnt pathway. In the presence of sufficient amount of Wnt ligand, E-cadherin levels are sensitive to the ratio of the rate of Slug activation via ß-catenin to the IC50 concentration of Slug necessary to inhibit E-cadherin production. CONCLUSIONS: The sensitivity of E-cadherin to the degradation rate of Slug, as well as the IC50 concentration of Slug necessary to inhibit E-cadherin production, shows how the adhesive nature of the cell depends on finely-tuned regulation of Slug. By highlighting the role of ß-catenin in the activation of EMT and the relationship between E-cadherin and Slug, this model identifies critical parameters of therapeutic concern, such as the threshold level of Dvl necessary to inactivate the GSK-3ß complex mediating ß-catenin degradation, the rate at which ß-catenin translocates to the nucleus, and the IC50 concentration of Slug needed to inhibit E-cadherin production.

Incorporating Concomitant Medications into Genome-Wide Analyses for the Study of Complex Disease and Drug Response.

Given the high costs of conducting a drug-response trial, researchers are now aiming to use retrospective analyses to conduct genome-wide association studies (GWAS) to identify underlying genetic contributions to drug-response variation. To prevent confounding results from a GWAS to investigate drug response, it is necessary to account for concomitant medications, defined as any medication taken concurrently with the primary medication being investigated. We use data from the Action to Control Cardiovascular Disease (ACCORD) trial in order to implement a novel scoring procedure for incorporating concomitant medication information into a linear regression model in preparation for GWAS. In order to accomplish this, two primary medications were selected: thiazolidinediones and metformin because of the wide-spread use of these medications and large sample sizes available within the ACCORD trial. A third medication, fenofibrate, along with a known confounding medication, statin, were chosen as a proof-of-principle for the scoring procedure. Previous studies have identified SNP rs7412 as being associated with statin response. Here we hypothesize that including the score for statin as a covariate in the GWAS model will correct for confounding of statin and yield a change in association at rs7412. The response of the confounded signal was successfully diminished from p = 3.19 × 10-7 to p = 1.76 × 10-5, by accounting for statin using the scoring procedure presented here. This approach provides the ability for researchers to account for concomitant medications in complex trial designs where monotherapy treatment regimens are not available.

Use of Bayesian Inference in Crystallographic Structure Refinement via Full Diffraction Profile Analysis.

A Bayesian inference method for refining crystallographic structures is presented. The distribution of model parameters is stochastically sampled using Markov chain Monte Carlo. Posterior probability distributions are constructed for all model parameters to properly quantify uncertainty by appropriately modeling the heteroskedasticity and correlation of the error structure. The proposed method is demonstrated by analyzing a National Institute of Standards and Technology silicon standard reference material. The results obtained by Bayesian inference are compared with those determined by Rietveld refinement. Posterior probability distributions of model parameters provide both estimates and uncertainties. The new method better estimates the true uncertainties in the model as compared to the Rietveld method.

Scientists urge DHS to improve Bioterrorism Risk Assessment.

In 2006, the Department of Homeland Security (DHS) completed its first Bioterrorism Risk Assessment (BTRA), intended to be the foundation for DHS's subsequent biennial risk assessments mandated by Homeland Security Presidential Directive 10 (HSPD-10). At the request of DHS, the National Research Council established the Committee on Methodological Improvements to the Department of Homeland Security's Biological Agent Risk Analysis to provide an independent, scientific peer review of the BTRA. The Committee found a number of shortcomings in the BTRA, including a failure to consider terrorists as intelligent adversaries in their models, unnecessary complexity in threat and consequence modeling and simulations, and a lack of focus on risk management. The Committee unanimously concluded that an improved BTRA is needed to provide a more credible foundation for risk-informed decision making.