Temporal patterns of bird mortality due to road traffic collisions in a Mediterranean region

ABSTRACT

Capsule: There was significant variation on the incidence of road traffic mortality across bird species, due to seasonal and weather effects but also due to differences between years.

Aims: To assess patterns of mortality due to traffic collision for six common bird species over a period of nine years in relation to seasonality and weather.

Methods: Road mortality surveys were performed on four road sections from 2005 to 2013 in southern Portugal. The analysis controlled for survey frequency, and carcass persistence and detectability.

Results: Overall, bird mortality decreased over time and was generally higher during spring and summer months. The lack of strong relationships between the weather variables and the observed mortality patterns suggests the existence of additional factors important in explaining the observed trends.

Conclusions: Our study provides evidence that bird mortality due to collision with vehicles may change between years and was highest during the breeding season. This could have population consequences, and highlights the need to further address large temporal scales in roadkill research.     

Mobile SARS‑CoV‑2 screening facilities for rapid deployment and university-based diagnostic laboratory

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions’ continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening. For this purpose, virus testing in the form of polymerase chain reaction (PCR) analysis and antibody detection in blood can be central. Mobile SARS-CoV-2 screening facilities with a built-in biosafety level (BSL)-2 laboratory were set up to allow the testing offer to be brought close to the subject group's workplace. University staff members, their expertise, and already available equipment were used to implement and operate the screening facilities and a certified diagnostic laboratory. This operation also included specimen collection, transport, PCR and antibody analysis, and informing subjects as well as public health departments. Screening facilities were established at different locations such as educational institutions, nursing homes, and companies providing critical supply chains for health care. Less than 4 weeks after the first imposed lockdown in Germany, a first mobile testing station was established featuring a build-in laboratory with two similar stations commencing operation until June 2020. During the 15-month project period, approximately 33,000 PCR tests and close to 7000 antibody detection tests were collected and analyzed. The presented approach describes the required procedures that enabled the screening facilities and laboratories to collect and process several hundred specimens each day under difficult conditions. This report can assist others in establishing similar setups for pandemic scenarios.     

Biochemical changes induced in seeds of <Emphasis Type="Italic">Brassicaceae</Emphasis> wild species during ageing

The aim of the present study was to determine whether the loss of seed germination capacity and vigour in seeds of four wild Brassicaceae species (Brassica repanda, Moricandia arvensis, Rorippa nasturtium-aquaticum and Sinapis alba) during ageing at 45°C and 90% relative humidity was related to changes in lipid peroxidation and membrane integrity. For all of the species, ageing reduced the final germination percentage and increased the length of time required to reach 50% of final germination (T ₅₀). Large differences in longevity were observed among the species. The times required for viability to be reduced to 80 and 50% of maximum germination (P80 and P50) were the lowest for B. repanda, and these values were two times longer for M. arvensis and R. nasturtium-aquaticum and five times longer for S. alba compared with B. repanda. A loss of seed viability was not associated with malondialdehyde accumulation, suggesting that lipid peroxidation did not cause seed deterioration under these conditions. However, the conductivity test effectively detected seed deterioration in these wild Brassicaceae species, and membrane permeability correlated with both germination and vigour loss. This correlation may provide a valuable mean for early detection of seed viability in wild Brassicaceae species.     

THE CONTRIBUTION OF GENE MOVEMENT TO THE “TWO RULES OF SPECIATION”

The two “rules of speciation”—the Large X‐effect and Haldane's rule—hold throughout the animal kingdom, but the underlying genetic mechanisms that cause them are still unclear. Two predominant explanations—the “dominance theory” and faster male evolution—both have some empirical support, suggesting that the genetic basis of these rules is likely multifarious. We revisit one historical explanation for these rules, based on dysfunctional genetic interactions involving genes recently moved between chromosomes. We suggest that gene movement specifically off or onto the X chromosome is another mechanism that could contribute to the two rules, especially as X chromosome movements can be subject to unique sex‐specific and sex chromosome specific consequences in hybrids. Our hypothesis is supported by patterns emerging from comparative genomic data, including a strong bias in interchromosomal gene movements involving the X and an overrepresentation of male reproductive functions among chromosomally relocated genes. In addition, our model indicates that the contribution of gene movement to the two rules in any specific group will depend upon key developmental and reproductive parameters that are taxon specific. We provide several testable predictions that can be used to assess the importance of gene movement as a contributor to these rules in the future.     

Does Antibiotic Resistance Evolve in Hospitals?

Nosocomial outbreaks of bacteria are well documented. Based on these incidents, and the heavy usage of antibiotics in hospitals, it has been assumed that antibiotic resistance evolves in hospital environments. To test this assumption, we studied resistance phenotypes of bacteria collected from patient isolates at a community hospital over a 2.5-year period. A graphical model analysis shows no association between resistance and patient information other than time of arrival. This allows us to focus on time-course data. We introduce a hospital transmission model, based on negative binomial delay. Our main contribution is a statistical hypothesis test called the Nosocomial Evolution of Resistance Detector (NERD). It calculates the significance of resistance trends occurring in a hospital. It can inform hospital staff about the effects of various practices and interventions, can help detect clonal outbreaks, and is available as an R package. We applied the NERD method to each of the 16 antibiotics in the study via 16 hypothesis tests. For 13 of the antibiotics, we found that the hospital environment had no significant effect on the evolution of resistance; the hospital is merely a piece of the larger picture. The p-values obtained for the other three antibiotics (cefepime, ceftazidime, and gentamicin) indicate that particular care should be taken in hospital practices with these antibiotics. One of the three, ceftazidime, was significant after accounting for multiple hypotheses, indicating a trend of decreased resistance for this drug.