Selectivity of mass extinctions: Patterns, processes, and future directions

A central question in the study of mass extinction is whether these events simply intensify background extinction processes and patterns versus change the driving mechanisms and associated patterns of selectivity. Over the past two decades, aided by the development of new fossil occurrence databases, selectivity patterns associated with mass extinction have become increasingly well quantified and their differences from background patterns established. In general, differences in geographic range matter less during mass extinction than during background intervals, while differences in respiratory and circulatory anatomy that may correlate with tolerance to rapid change in oxygen availability, temperature, and pH show greater evidence of selectivity during mass extinction. The recent expansion of physiological experiments on living representatives of diverse clades and the development of simple, quantitative theories linking temperature and oxygen availability to the extent of viable habitat in the oceans have enabled the use of Earth system models to link geochemical proxy constraints on environmental change with quantitative predictions of the amount and biogeography of habitat loss. Early indications are that the interaction between physiological traits and environmental change can explain substantial proportions of observed extinction selectivity for at least some mass extinction events. A remaining challenge is quantifying the effects of primary extinction resulting from the limits of physiological tolerance versus secondary extinction resulting from the loss of taxa on which a given species depended ecologically. The calibration of physiology-based models to past extinction events will enhance their value in prediction and mitigation efforts related to the current biodiversity crisis

Estimating encounter location distributions from animal tracking data

1. Ecologists have long been interested in linking individual behaviour with higher level processes. For motile species, this ‘upscaling’ is governed by how well any given movement strategy maximizes encounters with positive factors and minimizes encounters with negative factors. Despite the importance of encounter events for a broad range of ecological processes, encounter theory has not kept pace with developments in animal tracking or movement modelling. Furthermore, existing work has focused primarily on the relationship between animal movement and encounter rates while the relationship between individual movement and the spatial locations of encounter events in the environment has remained conspicuously understudied. 2. Here, we bridge this gap by introducing a method for describing the long-term encounter location probabilities for movement within home ranges, termed the conditional distribution of encounters (CDE). We then derive this distribution, as well as confidence intervals, implement its statistical estimator into open-source software and demonstrate the broad ecological relevance of this distribution. 3. We first use simulated data to show how our estimator provides asymptotically consistent estimates. We then demonstrate the general utility of this method for three simulation-based scenarios that occur routinely in biological systems: (a) a population of individuals with home ranges that overlap with neighbours; (b) a pair of individuals with a hard territorial border between their home ranges; and (c) a predator with a large home range that encompassed the home ranges of multiple prey individuals. Using GPS data from white-faced capuchins Cebus capucinus, tracked on Barro Colorado Island, Panama, and sleepy lizards Tiliqua rugosa, tracked in Bundey, South Australia, we then show how the CDE can be used to estimate the locations of territorial borders, identify key resources, quantify the potential for competitive or predatory interactions and/or identify any changes in behaviour that directly result from location-specific encounter probability. 4. The CDE enables researchers to better understand the dynamics of populations of interacting individuals. Notably, the general estimation framework developed in this work builds straightforwardly off of home range estimation and requires no specialized data collection protocols. This method is now openly available via the ctmm R package

A Riboswitch-Based Inducible Gene Expression System for Mycobacteria

Research on the human pathogen Mycobacterium tuberculosis (Mtb) would benefit from novel tools for regulated gene expression. Here we describe the characterization and application of a synthetic riboswitch-based system, which comprises a mycobacterial promoter for transcriptional control and a riboswitch for translational control. The system was used to induce and repress heterologous protein overexpression reversibly, to create a conditional gene knockdown, and to control gene expression in a macrophage infection model. Unlike existing systems for controlling gene expression in Mtb, the riboswitch does not require the co-expression of any accessory proteins: all of the regulatory machinery is encoded by a short DNA segment directly upstream of the target gene. The inducible riboswitch platform has the potential to be a powerful general strategy for creating customized gene regulation systems in Mtb

MARVELS-1: A face-on double-lined binary star masquerading as a resonant planetary system; and consideration of rare false positives in radial velocity planet searches

We have analyzed new and previously published radial velocity observations of MARVELS-1, known to have an ostensibly substellar companion in a ~6- day orbit. We find significant (~100 m/s) residuals to the best-fit model for the companion, and these residuals are naively consistent with an interior giant planet with a P = 1.965d in a nearly perfect 3:1 period commensuribility (|Pb/Pc - 3| < 10^{-4}). We have performed several tests for the reality of such a companion, including a dynamical analysis, a search for photometric variability, and a hunt for contaminating stellar spectra. We find many reasons to be critical of a planetary interpretation, including the fact that most of the three-body dynamical solutions are unstable. We find no evidence for transits, and no evidence of stellar photometric variability. We have discovered two apparent companions to MARVELS-1 with adaptive optics imaging at Keck; both are M dwarfs, one is likely bound, and the other is likely a foreground object. We explore false-alarm scenarios inspired by various curiosities in the data. Ultimately, a line profile and bisector analysis lead us to conclude that the ~100 m/s residuals are an artifact of spectral contamination from a stellar companion contributing ~15-30% of the optical light in the system. We conclude that origin of this contamination is the previously detected radial velocity companion to MARVELS-1, which is not, as previously reported, a brown dwarf, but in fact a G dwarf in a face-on orbit.Comment: ApJ 770, 119. 24 pp emulate ApJ style, 12 figures (One is very large). v2: corrects two (important!) errors: A priori chance of this alignment or worse is 0.1% (not 0.01%) and the primary has THREE total companions (not four

Wastewater Sequencing Reveals Community and Variant Dynamics of the Collective Human Virome

Wastewater is a discarded human by-product, but its analysis may help us understand the health of populations. Epidemiologists first analyzed wastewater to track outbreaks of poliovirus decades ago, but so-called wastewater-based epidemiology was reinvigorated to monitor SARS-CoV-2 levels while bypassing the difficulties and pit falls of individual testing. Current approaches overlook the activity of most human viruses and preclude a deeper understanding of human virome community dynamics. Here, we conduct a comprehensive sequencing-based analysis of 363 longitudinal wastewater samples from ten distinct sites in two major cities. Critical to detection is the use of a viral probe capture set targeting thousands of viral species or variants. Over 450 distinct pathogenic viruses from 28 viral families are observed, most of which have never been detected in such samples. Sequencing reads of established pathogens and emerging viruses correlate to clinical data sets of SARS-CoV-2, influenza virus, and monkeypox viruses, outlining the public health utility of this approach. Viral communities are tightly organized by space and time. Finally, the most abundant human viruses yield sequence variant information consistent with regional spread and evolution. We reveal the viral landscape of human wastewater and its potential to improve our understanding of outbreaks, transmission, and its effects on overall population health

Clinical phenotypes of perinatal depression and time of symptom onset: analysis of data from an international consortium

Background The perinatal period is a time of high risk for onset of depressive disorders and is associated with substantial morbidity and mortality, including maternal suicide. Perinatal depression comprises a heterogeneous group of clinical subtypes, and further refinement is needed to improve treatment outcomes. We sought to empirically identify and describe clinically relevant phenotypic subtypes of perinatal depression, and further characterise subtypes by time of symptom onset within pregnancy and three post-partum periods. Methods Data were assembled from a subset of seven of 19 international sites in the Postpartum Depression: Action Towards Causes and Treatment (PACT) Consortium. In this analysis, the cohort was restricted to women aged 19–40 years with information about onset of depressive symptoms in the perinatal period and complete prospective data for the ten-item Edinburgh postnatal depression scale (EPDS). Principal components and common factor analysis were used to identify symptom dimensions in the EPDS. The National Institute of Mental Health research domain criteria functional constructs of negative valence and arousal were applied to the EPDS dimensions that reflect states of depressed mood, anhedonia, and anxiety. We used k-means clustering to identify subtypes of women sharing symptom patterns. Univariate and bivariate statistics were used to describe the subtypes. Findings Data for 663 women were included in these analyses. We found evidence for three underlying dimensions measured by the EPDS: depressed mood, anxiety, and anhedonia. On the basis of these dimensions, we identified five distinct subtypes of perinatal depression: severe anxious depression, moderate anxious depression, anxious anhedonia, pure anhedonia, and resolved depression. These subtypes have clear differences in symptom quality and time of onset. Anxiety and anhedonia emerged as prominent symptom dimensions with post-partum onset and were notably severe. Interpretation Our findings show that there might be different types and severity of perinatal depression with varying time of onset throughout pregnancy and post partum. These findings support the need for tailored treatments that improve outcomes for women with perinatal depression

The role of the smartphone in the transition from medical student to foundation trainee: a qualitative interview and focus group study

Background The transition from medical student to junior doctor is one of the most challenging in medicine, affecting both doctor and patient health. Opportunities to support this transition have arisen from advances in mobile technology and increased smartphone ownership. Methods This qualitative study consisted of six in-depth interviews and two focus groups with Foundation Year 1 Trainees (intern doctors) and final year medical students within the same NHS Trust. A convenience sample of 14 participants was recruited using chain sampling. Interviews and focus groups were recorded, transcribed verbatim, analysed in accordance with thematic analysis and presented below in keeping with the standards for reporting qualitative research. Results Participants represented both high and low intensity users. They used their smartphones to support their prescribing practices, especially antimicrobials through the MicroGuide™ app. Instant messaging, via WhatsApp, contributed to the existing bleep system, allowing coordination of both work and learning opportunities across place and time. Clinical photographs were recognised as being against regulations but there had still been occasions of use despite this. Concerns about public and colleague perceptions were important to both students and doctors, with participants describing various tactics employed to successfully integrate phone use into their practices. Conclusion This study suggests that both final year medical students and foundation trainees use smartphones in everyday practice. Medical schools and healthcare institutions should seek to integrate such use into core curricula/training to enable safe and effective use and further ease the transition to foundation training. We recommend juniors are reminded of the potential risks to patient confidentiality associated with smartphone use

The National COVID Cohort Collaborative (N3C): Rationale, design, infrastructure, and deployment.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) poses societal challenges that require expeditious data and knowledge sharing. Though organizational clinical data are abundant, these are largely inaccessible to outside researchers. Statistical, machine learning, and causal analyses are most successful with large-scale data beyond what is available in any given organization. Here, we introduce the National COVID Cohort Collaborative (N3C), an open science community focused on analyzing patient-level data from many centers. MATERIALS AND METHODS: The Clinical and Translational Science Award Program and scientific community created N3C to overcome technical, regulatory, policy, and governance barriers to sharing and harmonizing individual-level clinical data. We developed solutions to extract, aggregate, and harmonize data across organizations and data models, and created a secure data enclave to enable efficient, transparent, and reproducible collaborative analytics. RESULTS: Organized in inclusive workstreams, we created legal agreements and governance for organizations and researchers; data extraction scripts to identify and ingest positive, negative, and possible COVID-19 cases; a data quality assurance and harmonization pipeline to create a single harmonized dataset; population of the secure data enclave with data, machine learning, and statistical analytics tools; dissemination mechanisms; and a synthetic data pilot to democratize data access. CONCLUSIONS: The N3C has demonstrated that a multisite collaborative learning health network can overcome barriers to rapidly build a scalable infrastructure incorporating multiorganizational clinical data for COVID-19 analytics. We expect this effort to save lives by enabling rapid collaboration among clinicians, researchers, and data scientists to identify treatments and specialized care and thereby reduce the immediate and long-term impacts of COVID-19

How absolute is zero? An evaluation of historical and current definitions of malaria elimination

Decisions to eliminate malaria from all or part of a country involve a complex set of factors, and this complexity is compounded by ambiguity surrounding some of the key terminology, most notably "control" and "elimination." It is impossible to forecast resource and operational requirements accurately if endpoints have not been defined clearly, yet even during the Global Malaria Eradication Program, debate raged over the precise definition of "eradication." Analogous deliberations regarding the meaning of "elimination" and "control" are basically nonexistent today despite these terms' core importance to programme planning. To advance the contemporary debate about these issues, this paper presents a historical review of commonly used terms, including control, elimination, and eradication, to help contextualize current understanding of these concepts. The review has been supported by analysis of the underlying mathematical concepts on which these definitions are based through simple branching process models that describe the proliferation of malaria cases following importation. Through this analysis, the importance of pragmatic definitions that are useful for providing malaria control and elimination programmes with a practical set of strategic milestones is emphasized, and it is argued that current conceptions of elimination in particular fail to achieve these requirements. To provide all countries with precise targets, new conceptual definitions are suggested to more precisely describe the old goals of "control" - here more exactly named "controlled low-endemic malaria" - and "elimination." Additionally, it is argued that a third state, called "controlled non-endemic malaria," is required to describe the epidemiological condition in which endemic transmission has been interrupted, but malaria resulting from onwards transmission from imported infections continues to occur at a sufficiently high level that elimination has not been achieved. Finally, guidelines are discussed for deriving the separate operational definitions and metrics that will be required to make these concepts relevant, measurable, and achievable for a particular environment

Crop Updates 2010 - Crop Specific

This session covers twenty four papers from different authors: PLENARY 1. Challenges facing western Canadian cropping over the next 10 years, Hugh J Beckie, Research Centre, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan CROP SPECIFIC Breeding 2. The challenge of breeding canola hybrids – new opportunities for WA growers, Wallace Cowling, Research Director, Canola Breeders Western Australia Pty Ltd 3. Chickpea 2009 crop variety testing of germplasm developed by DAFWA/CLIMA/ICRISAT/COGGO alliance. Khan, TN1,3, Adhikari, K1,3, Siddique, K2, Garlinge, J1, Smith, L1, Morgan, S1 and Boyd, C1 1Department of Agriculture and Food, Western Australia (DAFWA), 2Insititute of Agriculture, The University of Western Australia (UWA), 3Centre for Legumes in Mediterranean Agriculture (CLIMA), The University of Western Australia 4. PBA Pulse Breeding Australia – 2009 Field Pea Results, Ian Pritchard1, Chris Veitch1, Colin Boyd1, Stuart Morgan1, Alan Harris1 and Tony Leonforte2, 1Department of Agriculture and Food, Western Australia, 2Department of Primary Industries, Victoria 5. PBA Pulse Breeding Australia – 2009 Chickpea Results, Ian Pritchard1, Chris Veitch1, Colin Boyd1, Murray Blyth1, Shari Dougal1 and Kristy Hobson2 1Department of Agriculture and Food, Western Australia, 2Department of Primary Industries, Victoria Decision Support 6. A tool for identifying problems in wheat paddocks, Ben Curtis and Doug Sawkins, Department of Agriculture and Food 7. DAFWA Seasonal Forecast for 2010, Stephens, D, Department of Agriculture and Food, Western Australian, Climate and Modelling Group Disease 8. Enhancement of black spot resistance in field pea, Kedar Adhikari, T Khan, S Morgan and C Boyd, Department of Agriculture and Food, 9. fungicide management of yellow spot in wheat, Ciara Beard, Kith Jayasena, Kazue Tanaka and Anne Smith, Department of Agriculture and Food 10. Resistance to infection by Beet western yellows virus in four Australian canola varieties, Brenda Coutts and Roger Jones, Department of Agriculture and Food 11. Yellow spot carryover risk from stubble in wheat-on-wheat rotations, Jean Galloway, Pip Payne and Tess Humphreys, Department of Agriculture and Food 12. Fungicides for the future: Management of Barley Powdery Mildew and Leaf Rust, Kith Jayasena, Kazue Tanaka and William MacLeod, Department of Agriculture and Food 13. 2009 canola disease survey and management options for blackleg and Sclerotinia in 2010, Ravjit Khangura, WJ MacLeod, M Aberra and H Mian, Department of Agriculture and Food 14. Impact of variety and fungicide on carryover of stubble borne inoculum and yellow spot severity in continuous wheat cropping, Geoff Thomas, Pip Payne, Tess Humphreys and Anne Smith, Department of Agriculture and Food 15. Limitations to the spread of Wheat streak mosaic virus by the Wheat curl mite in WA during 2009, Dusty Severtson, Peter Mangano, Brenda Coutts, Monica Kehoe and Roger Jones, Department of Agriculture and Food 16. Viable solutions for barley powdery mildew, Madeline A. Tucker, Australian Centre for Necrotrophic Fungal Pathogens, Murdoch University Marketing 17. The importance of varietal accreditation in a post-deregulation barley marketing environment, Neil Barker, Barley Australia 18. Can Australia wheat meet requirements for a new middle east market? Robert Loughman, Larisa Cato, Department of Agriculture and Food, and Ken Quail, BRI Australia VARIETY PERFORMANCE 19. Sowing rate and time for hybrid vs open-pollinated canola, Mohammad Amjad and Mark Seymour, Department of Agriculture and Food 20. HYOLA® National Hybrid vs OP Canola Hybrid F1 vs Retained Seed Generation Trial Results and recommendations for growers, Justin Kudnig, Mark Thompson, Anton Mannes, Michael Uttley, Chris Fletcher, Andrew Etherton, Nick Joyce and Kate Light, Pacific Seeds Australia 21. HYOLA® National Hybrid vs OP Canola Sowing Rate Trial Results and plant population recommendations for Australian growers, Justin Kudnig, Mark Thompson, Anton Mannes, Michael Uttley, Andrew Etherton, Chris Fletcher, Nick Joyce and Kate Light, Pacific Seeds Australia; Peter Hamblin, Agritech Research Young, NSW, Michael Lamond, Agrisearch, York, Western Australia 22. Desi chickpea agronomy for 2010, Alan Meldrum, Pulse Australia and Wayne Parker, Department of Agriculture and Food 23. New wheat varieties – exploit the benefits and avoid the pitfalls, Steve Penny, Sarah Ellis, Brenda Shackley, Christine Zaicou, Shahajahan Miyan, Darshan Sharma and Ben Curtis, Department of Agriculture and Food 24. The influence of genetics and environment on the level of seed alkaloid in narrow-leafed lupins, Greg Shea1, Bevan Buirchell1, David Harris2 and Bob French1, 1Department of Agriculture and Food, 2ChemCentr