Sospechas y evidencia: revisión de las causas de la extinción local y del declive de los mejillones de agua dulce

Sospechas y evidencia: revisión de las causas de la extinción local y del declive de los mejillones de agua dulce La conservación de la biodiversidad requiere pruebas fiables de las causas de extinción local. Utilizando los mejillones de agua dulce como ejemplo, llevamos a cabo esta valoración sistemática, la primera que se ha realizado, de la evidencia de peligro para cualquier grupo de organismos. Revisamos artículos que publicaban conclusiones sobre las causas de las extinciones locales, evaluando la calidad de las pruebas según una escala objetiva. Encontramos que únicamente el 48% de los estudios presentaban relaciones plausibles entre la extinción local y sus causas. Los análisis carecían de resolución, dado que más del 75% de los estudios considerados (n = 124) sugerían múltiples causas de extinción local. Los estudios llevados a cabo en grandes áreas, y los que presentaban menos pruebas, son los que abogaban por un mayor número de causas. A pesar de las evidencias, que frecuentemente eran débiles, existía un acuerdo sustancial sobre la identidad de las causas; la más frecuente era la destrucción o alteración del hábitat, pero se postulaban muchas más. A pesar de que la extinción local de los mejillones de agua dulce es indudablemente una realidad, las pruebas podrían ser más consistentes. En estos animales y en muchos otros, la evidencia de las causas de su extinción local a menudo ha sido circunstancial. Presentamos aquí un estudio sistemático que pueden utilizar los ecólogos, para fortalecer las evidencias concernientes a las causas de las extinciones locales. También hemos reflejado la relación entre la fortaleza de la evidencia y las prioridades económicas de las investigaciones. Palabras clave: Evidencia, Extinción, Extinción local, Agua dulce, Mejillones.Conservation of biodiversity requires reliable evidence of the causes of extirpation. Using freshwater mussels as an example, we performed the first–ever systematic assessment of the evidence for endangerment of any group of organisms. We surveyed articles publishing conclusions about the cause of local extirpation by assessing the quality of evidence on an objective scale. We found that only 48% of studies presented plausible links between extirpation and causes. Analyses lacked resolution since more than 75% of all studies considered (n = 124) suggested multiple causes of extirpation. Studies performed over large areas and those presenting less evidence postulated the most causes. Despite the frequently weak evidence, there was substantial agreement on the identity of causes; the most frequent was habitat destruction or alteration but many others were postulated. Although mussel extirpation is undoubtedly real, the evidence could be stronger. In these animals and others, evidence of the causes of extirpation has often been circumstantial. We present a systematic approach ecologists can use to strengthen the evidence concerning the causes of extirpation. We also reflect on the link between the strength of evidence and research funding priorities. Key words: Evidence, Extinction, Extirpation, Freshwater, Mussels.La conservación de la biodiversidad requiere pruebas fiables de las causas de extinción local. Utilizando los mejillones de agua dulce como ejemplo, llevamos a cabo esta valoración sistemática, la primera que se ha realizado, de la evidencia de peligro para cualquier grupo de organismos. Revisamos artículos que publicaban conclusiones sobre las causas de las extinciones locales, evaluando la calidad de las pruebas según una escala objetiva. Encontramos que únicamente el 48% de los estudios presentaban relaciones plausibles entre la extinción local y sus causas. Los análisis carecían de resolución, dado que más del 75% de los estudios considerados (n = 124) sugerían múltiples causas de extinción local. Los estudios llevados a cabo en grandes áreas, y los que presentaban menos pruebas, son los que abogaban por un mayor número de causas. A pesar de las evidencias, que frecuentemente eran débiles, existía un acuerdo sustancial sobre la identidad de las causas; la más frecuente era la destrucción o alteración del hábitat, pero se postulaban muchas más. A pesar de que la extinción local de los mejillones de agua dulce es indudablemente una realidad, las pruebas podrían ser más consistentes. En estos animales y en muchos otros, la evidencia de las causas de su extinción local a menudo ha sido circunstancial. Presentamos aquí un estudio sistemático que pueden utilizar los ecólogos, para fortalecer las evidencias concernientes a las causas de las extinciones locales. También hemos reflejado la relación entre la fortaleza de la evidencia y las prioridades económicas de las investigaciones. Palabras clave: Evidencia, Extinción, Extinción local, Agua dulce, Mejillones

Improved surveillance for early detection of a potential invasive species: the alien Rose-ringed parakeet Psittacula krameri in Australia

Published online: 12 November 2016The Rose-ringed parakeet Psittacula krameri is the most widely introduced parrot in the world, and is an important agricultural pest and competitor with native wildlife. In Australia, it is classified as an ‘extreme threat’, yet captive individuals frequently escape into the wild. The distribution and frequency of incursions are currently unknown, as are the potential impacts of the species in Australia. This lack of critical ecological information greatly limits effective biosecurity surveillance and decision-making efforts. We compiled a unique dataset, which combined passive surveillance sources from government and online resources, for all available information on parakeet detections at-large in Australia. We investigated whether geographic variables successfully predicted parakeet incursions, and used species distribution models to assess the potential distribution and economic impacts on agricultural assets. We recorded 864 incursions for the period 1999–2013; mostly escaped birds reported to missing animal websites. Escapes were reported most frequently within, or around, large cities. Incursions were best predicted by factors related to human presence and activity, such as global human footprint and intensive land uses. We recommend surveillance of high (predicted) establishment areas adjacent to cities where a feral parakeet population could most affect horticultural production. Novel passive surveillance datasets combined with species distribution models can be used to identify the regions where potential invasive species are most likely to establish. Subsequently, active surveillance can be targeted to the areas of highest predicted potential risk. We recommend an integrated approach that includes outreach programs involving local communities, as well as traditional biosecurity surveillance, for detecting new incursions.Miquel Vall-llosera, Andrew P. Woolnough, Dean Anderson, Phillip Casse

Virtual reality, ultrasound-guided liver biopsy simulator: Development and performance discrimination

Objectives: The aim of this article was to identify and prospectively investigate simulated ultrasound-guided targeted liver biopsy performance metrics as differentiators between levels of expertise in interventional radiology. Methods: Task analysis produced detailed procedural step documentation allowing identification of critical procedure steps and performance metrics for use in a virtual reality ultrasound-guided targeted liver biopsy procedure. Consultant (n=14; male=11, female=3) and trainee (n=26; male=19, female=7) scores on the performance metrics were compared. Ethical approval was granted by the Liverpool Research Ethics Committee (UK). Independent t-tests and analysis of variance (ANOVA) investigated differences between groups. Results: Independent t-tests revealed significant differences between trainees and consultants on three performance metrics: targeting, p=0.018, t=22.487 (22.040 to 20.207); probe usage time, p=0.040, t=2.132 (11.064 to 427.983); mean needle length in beam, p=0.029, t=22.272 (20.028 to 20.002). ANOVA reported significant differences across years of experience (0–1, 1–2, 3+ years) on seven performance metrics: no-go area touched, p=0.012; targeting, p=0.025; length of session, p=0.024; probe usage time, p=0.025; total needle distance moved, p=0.038; number of skin contacts, p<0.001; total time in no-go area, p=0.008. More experienced participants consistently received better performance scores on all 19 performance metrics. Conclusion: It is possible to measure and monitor performance using simulation, with performance metrics providing feedback on skill level and differentiating levels of expertise. However, a transfer of training study is required

Intercomparison of methods of coupling between convection and large-scale circulation. 2: comparison over non-uniform surface conditions

As part of an international intercomparison project, the weak temperature gradient (WTG) and damped gravity wave (DGW) methods are used to parameterize large-scale dynamics in a set of cloud-resolving models (CRMs) and single column models (SCMs). The WTG or DGW method is implemented using a configuration that couples a model to a reference state defined with profiles obtained from the same model in radiative-convective equilibrium. We investigated the sensitivity of each model to changes in SST, given a fixed reference state. We performed a systematic comparison of the WTG and DGW methods in different models, and a systematic comparison of the behavior of those models using the WTG method and the DGW method. The sensitivity to the SST depends on both the large-scale parameterization method and the choice of the cloud model. In general, SCMs display a wider range of behaviors than CRMs. All CRMs using either the WTG or DGW method show an increase of precipitation with SST, while SCMs show sensitivities which are not always monotonic. CRMs using either the WTG or DGW method show a similar relationship between mean precipitation rate and column-relative humidity, while SCMs exhibit a much wider range of behaviors. DGW simulations produce large-scale velocity profiles which are smoother and less top-heavy compared to those produced by the WTG simulations. These large-scale parameterization methods provide a useful tool to identify the impact of parameterization differences on model behavior in the presence of two-way feedback between convection and the large-scale circulation

Validity and worth in the science curriculum: learning school science outside the laboratory

It is widely acknowledged that there are problems with school science in many developed countries of the world. Such problems manifest themselves in a progressive decline in pupil enthusiasm for school science across the secondary age range and the fact that fewer students are choosing to study the physical sciences at higher levels and as careers. Responses to these developments have included proposals to reform the curriculum, pedagogy and the nature of pupil discussion in science lessons. We support such changes but argue from a consideration of the aims of science education that secondary school science is too rooted in the science laboratory; substantially greater use needs to be made of out-of-school sites for the teaching of science. Such usage should result in a school science education that is more valid and more motivating and is better at fulfilling defensible aims of school science education. Our contention is that laboratory-based school science teaching needs to be complemented by out-of-school science learning that draws on the actual world (e.g. through fieldtrips), the presented world (e.g. in science centres, botanic gardens, zoos and science museums) and the virtual worlds that are increasingly available through information and communications technologies (ICT)

Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception

Thickness perception of starch-thickened products during eating has been linked to starch viscosity and salivary amylase activity. Calcium is an essential cofactor for α-amylase and there is anecdotal evidence that adding extra calcium affects amylase activity in processes like mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase activity and (2) to measure the effect of calcium concentration on apparent viscosity and thickness perception when interacting with salivary α-amylase in starch-based samples. α-Amylase activity in saliva samples from 28 people was assessed using a typical starch pasting cycle (up to 95 °C). The activity of the enzyme (as measured by the change in starch apparent viscosity) was maintained by the presence of calcium, probably by protecting the enzyme from heat denaturation. Enhancement of α-amylase activity by calcium at 37 °C was also observed although to a smaller extent. Sensory analysis showed a general trend of decreased thickness perception in the presence of calcium, but the result was only significant for one pair of samples, suggesting a limited impact of calcium enhanced enzyme activity on perceived thickness

The sub-seasonal to seasonal prediction (S2S) project database

A database containing sub-seasonal to seasonal forecasts from 11 operational centres is available to the research community and will help advance our understanding of the sub-seasonal to seasonal time range. Demands are growing rapidly in the operational prediction and applications communities for forecasts that fill the gap between medium-range weather and long-range or seasonal forecasts. Based on the potential for improved forecast skill at the sub-seasonal to seasonal time range, a sub-seasonal prediction (S2S) research project has been established by the World Weather Research Program/World Climate Research Program. A main deliverable of this project is the establishment of an extensive database, containing sub-seasonal (up to 60 days) forecasts, 3-weeks behind real-time, and reforecasts from 11 operational centers, modelled in part on the THORPEX Interactive Grand Global Ensemble (TIGGE) database for medium range forecasts (up to 15 days). The S2S database, available to the research community since May 2015, represents an important tool to advance our understanding of the sub-seasonal to seasonal time range that has been considered for a long time as a “desert of predictability”. In particular, this database will help identify common successes and shortcomings in the model simulation and prediction of sources of sub-seasonal to seasonal predictability. For instance, a preliminary study suggests that the S2S models underestimate significantly the amplitude of the Madden Julian Oscillation (MJO) teleconnections over the Euro-Atlantic sector. The S2S database represents also an important tool for case studies of extreme events. For instance, a multi-model combination of S2S models displays higher probability of a landfall over Vanuatu islands 2 to 3 weeks before tropical cyclone Pam devastated the islands in March 2015

Does it look safe? An eye tracking study into the visual aspects of fear of crime

Studies of fear of crime often focus on demographic and social factors, but these can be difficult to change. Studies of visual aspects have suggested that features reflecting incivilities, such as litter, graffiti, and vandalism increase fear of crime, but methods often rely on participants actively mentioning such aspects, and more subtle, less conscious aspects may be overlooked. To address these concerns, the present study examined people’s eye movements while they judged scenes for safety. Forty current and former university students were asked to rate images of day-time and night-time scenes of Lincoln, UK (where they studied) and Egham, UK (unfamiliar location) for safety, maintenance and familiarity, while their eye movements were recorded. Another twenty-five observers not from Lincoln or Egham rated the same images in an internet survey. Ratings showed a strong association between safety and maintenance and lower safety ratings for night-time scenes for both groups, in agreement with earlier findings. Eye movements of the Lincoln participants showed increased dwell times on buildings, houses, and vehicles during safety judgments, and increased dwell times on streets, pavements, and markers of incivilities for maintenance. Results confirm that maintenance plays an important role in perceptions of safety, but eye movements suggest that observers also look for indicators of current or recent presence of people