Urbanization is a persistent and widespread driver of global environmental change, potentially shaping evolutionary processes due to genetic drift and reduced gene flow in cities induced by habitat fragmentation and small population sizes. We tested this prediction for the eastern grey squirrel (Sciurus carolinensis), a common and conspicuous forest-dwelling rodent, by obtaining 44K SNPs using reduced representation sequencing (ddRAD) for 403 individuals sampled across the species' native range in eastern North America. We observed moderate levels of genetic diversity, low levels of inbreeding, and only a modest signal of isolation-by-distance. Clustering and migration analyses show that estimated levels of migration and genetic connectivity were higher than expected across cities and forested areas, specifically within the eastern portion of the species' range dominated by urbanization, and genetic connectivity was less than expected within the western range where the landscape is fragmented by agriculture. Landscape genetic methods revealed greater gene flow among individual squirrels in forested regions, which likely provide abundant food and shelter for squirrels. Although gene flow appears to be higher in areas with more tree cover, only slight discontinuities in gene flow suggest eastern grey squirrels have maintained connected populations across urban areas in all but the most heavily fragmented agricultural landscapes. Our results suggest urbanization shapes biological evolution in wildlife species depending strongly on the composition and habitability of the landscape matrix surrounding urban areas.

This article discusses the contention in the commented-upon paper that Brillouin precursors generated by 5G New Radio (5G NR) and other cellular systems are a possible cause of tissue damage at deeper layers of tissue than the power penetration depth of the carrier frequency. The original theory for Brillouin precursors from pulsed radiofrequency signals (RF-EMF) and speculation about their possible health effects dates back to the 1990's and was based on studies of the propagation of very short (nanosecond) ultrawide-bandwidth RF pulses through water. This assumption is not correct for cellular telephone signals due to their narrow bandwidth. The commented-on paper provides no alternative rationale as to why Brillouin effects should cause tissue damage from RF-EMF radiation from cellular and other communications systems. Other inaccuracies in this paper concerning thermal responses of tissue to RF-EMF are also noted.

AbstractObjectiveThree hypotheses about poor recruitment and collapse of Striped Bass Morone saxatilis in Chesapeake Bay during the 1970s and 1980s (excessive larval mortality related to water quality, recruitment overfishing, or a combination) emerged from intense investigations during the mid‐1980s into the early 1990s. Stock collapse during the 1970s and 1980s and recovery in 1995 were largely attributed to fishing mortality and this premise largely drives management. Stock and larval habitat assessments were not available before the early 1980s and habitat assessments were discontinued after recovery. I used egg and juvenile index time‐series that extended back to 1955 to test these three hypotheses about changes in productivity.MethodsLong‐term (1955–2019) indices of recruitment (juvenile index [JI]), spawning dispersion in time and space (Ep, proportion of plankton net samples with eggs), and an index of relative larval survival (RLS = JI/Ep) for spawning areas in Maryland’s portion of Chesapeake Bay were used to investigate whether larval survival patterns were stable (supported the overfishing hypothesis) or changed (supported the larval mortality hypothesis).ResultBaywide Ep estimates were within similar higher ranges during 1957–1981 and 1989–2019, and were low enough to affect recruitment during 1982–1988. While there was a strong relationship of baywide Ep to spawning stock biomass (SSB) estimated by the stock assessment during recovery (1982–1995), estimates of Ep went from depleted to a high level earlier than SSB estimates. Estimates of postrecovery Ep and SSB were both high, but did not have a relationship. A decline in SSB that began in 2012 was not evident with Ep. A shift to low JIs in the early 1970s was followed by a decline in baywide Ep after 1979. Estimates of RLS were higher in 1960s, declined in the early to mid‐1970s, were mostly low into the early 1990s, and became higher afterward. Recovery of Ep after 1988 was accompanied by recovery of larval survival a few years later. Strong correlations of juvenile indices of Striped Bass, White Perch Morone americana, and Yellow Perch Perca flavescens further supported the larval survival hypothesis; these anadromous fish share larval nurseries in space and time, but have different life histories and fisheries that make simultaneous overfishing unlikely.ConclusionDeterioration of larval survival initiated the collapse of Chesapeake Bay Striped Bass and improvement contributed to recovery. The hypothesis that collapse and recovery was solely driven by fishing was not supported, but excessive fishing pressure lowered Ep and SSB and contributed to poor recruitment during 1982–1988. Long‐term climate patterns and warming, deterioration and improvement in acidic deposition, concurrent increases in freshwater salinization and alkalinization, and shifts in agriculture and watershed management indicated shifts in larval habitat suitability were plausible.

AbstractObjectiveFisheries managers and anglers have expressed concerns regarding warmwater angling mortality, representing a need to evaluate mortality rates at various water temperatures and multiple latitudes. Up to 97% of Muskellunge Esox masquinongy caught by anglers are released, and previous research on catch and release (C&R) for Muskellunge has suggested relatively low mortality rates (0–5%). However, those studies were all conducted within the range of water temperatures that are thermally optimal for Muskellunge and generally at water temperatures less than 25°C. As many Muskellunge populations routinely experience temperatures greater than 25°C during the summer months our objective was to quantify warmwater (>25°C) C&R mortality rates in Muskellunge.MethodsWe collected 102 adult Muskellunge (>760 mm) and stocked them into and identify factors influencing mortality by using experimental ponds. Adult Muskellunge (n = 102) were stocked into eight earthen or plastic‐lined flow‐through ponds (0.06–0.71 ha) at densities less than 16 fish/ha. Muskellunge (n = 50) were angled by utilizing specialized Muskellunge fishing gear at water temperatures of 19.6–32.6°C, with 32 fish being caught at temperatures exceeding 25°C. After being angled, fish were closely monitored for 2 weeks to assess mortality; fish that remained uncaught during the experiment were used as controls (n = 53).ResultMortality was greater for angled fish (30.0%) than for control fish (11.3%). Differences in C&R mortality were compared across a range of temperature regimes using Firth logistic regression. Five‐day cumulative temperature and net time were positively related to the probability of mortality, but size and sex were unrelated to mortality. Increasing C&R mortality with temperature was mitigated somewhat by lower catch rates at higher temperatures. Mortalities per 100 angler‐hours were 0 at <25°C, 4.98 at 25.00–27.49°C, 2.48 at 27.5–30.0°C, and 1.17 at >30°C.ConclusionRecent field studies have identified the importance of thermal refuge in mitigating summer C&R mortality of Muskellunge. This study identified specific temperature conditions responsible for elevated mortality in the absence of refugia. Although increasing temperatures above 25°C led to increasing C&R mortality in our ponds, lower catchability seemingly provided some mitigation. The interactive effects of thermal refugia and catch rates with temperature warrant further investigations into population‐level effects at varying levels of exploitation.

Oncologists and families of ICU patients lack common language when discussing status and prognosis. Harmful jargon abounds.

Previous studies have reported select contaminants of emerging concern (CECs) in limited areas of the Chesapeake Bay (USA), but no comprehensive efforts have been conducted. In this work, 43 antibiotics, 9 hormones, 11 UV filters, and sucralose, were measured in matched water, sediment, and oyster samples from 58 sites. The highest sucralose concentration was 3051 ng L-1 in a subwatershed with 4.43 million liters of wastewater effluent per day (MLD) and 4385 septic systems. Although antibiotic occurrence was generally low in subwatersheds located in less populated areas, 102 ng L-1 ciprofloxacin was detected downstream of 0.58 MLD wastewater effluent and 10 animal feeding operations. Hormones were not regularly detected in water (2%) or oysters (37%), but the high detection frequencies in sediment (74%) were associated with septic systems. UV filters were ubiquitously detected in oysters, and octisalate exhibited the highest concentration (423 ng g-1). Oyster-phase oxybenzone and aqueous-phase sucralose concentrations were significantly correlated to wastewater effluent and septic systems, respectively. Toxicity outcomes were predicted for homosalate and octisalate throughout the Bay, and antimicrobial resistance concerns were noted for the Chester River. The geospatial and co-occurrence relationships constitute crucial advances to understanding CEC occurrence in the Chesapeake Bay and elsewhere.

Modeling of fecundity with allometric, nutritional, and environmental covariates has increased sensitivity of reproductive metrics in many fish species. In estuaries with heavy anthropogenic influence, resident species often experience sublethal health impacts because of increased stress, which can include increases in gonadal pathology, intersex, or potential reproductive failure. This study models the fecundity of the estuarine species White Perch Morone americana in response to health parameters identified as signals of habitat stress, including gross pathology presentation, nutritional condition, and disease presence. Subpopulation fecundity in the Choptank River (Maryland) of the Chesapeake Bay was estimated using stereological fecundity sampling methods and modeled using information-theoretic approaches of model selection. Nutritional and health parameters identified through health assessment techniques, specific somatic indices, and disease presence were selected as covariates. Nutrition demonstrated limited influence on model fit as compared to models with only conventional allometric variables such as weight and length. Of the health variables, gross pathology and somatic indices showed minimal influence on selection, but mycobacterial infection, a chronic condition in the Chesapeake Bay among temperate basses, showed measurable influence. Models with mycobacteriosis included were 40 times more likely the best fit when compared to models with only allometric parameters. Whether this has a region-wide influence on all subpopulations will require further research and sampling of the magnitude of mycobacteriosis infection.

Previous studies in dogs with degenerative mitral valve disease (DMVD) have identified altered myocardial energy metabolism and oxidation, which might contribute to cardiac hypertrophy. Diets rich in medium chain fatty acids and antioxidants are a potential means of treatment. A previous clinical study found significantly smaller left atrial diameter (LAD) and left atrium-to-aorta diameter ratio (LA : Ao) in dogs with subclinical DMVD fed a specially formulated diet vs control diet for 6 months. A specially formulated diet will slow or arrest left heart enlargement in dogs with subclinical DMVD over 365 days. One hundred twenty-seven dogs with unmedicated subclinical DMVD; 101 dogs in the per protocol cohort. Randomized double-blinded controlled multicenter clinical trial. The study's primary composite outcome measure was the sum of percentage change in LAD and left ventricular internal dimension at end-diastole (LVIDd) at day 365. In the per protocol cohort, the outcome measure increased by 8.0% (95% confidence interval [CI], 2.9%-13.1%) in dogs receiving the test diet vs 8.8% (95% CI, 5.1%-12.5%) in dogs receiving control diet (P = .79). Neither component of the primary outcome measure was significantly different between groups (LAD, P = .65; LVIDd, P = .92). No difference was found in mitral valve E wave velocity (P = .36) or the proportion of dogs withdrawn from the study because of worsening DMVD and heart enlargement (P = .41). Feeding a specially formulated diet for 365 days was not associated with a significantly different rate of change of left heart size in dogs with subclinical DMVD as compared to control.

Cryopreservation and germplasm repositories offer a variety of potential benefits to aquaculture industries. Despite this, no comprehensive repository systems exist for any prominent aquaculture species. A species that could greatly benefit from the use of cryopreserved sperm and repository storage is the eastern oyster, Crassostrea virginica. High-throughput cryopreservation protocols already exist for this species, and the easy transport of frozen sperm could facilitate selective breeding programs that address pressing challenges currently faced in the industry, such as mortality due to low-salinity conditions. This study addressed the gap between cryopreservation protocols and repository development in the oyster industry by creating simulation models to evaluate cryopreservation needs at three different scales of production. The effects of high-throughput device options and three key parameters (straws per oyster, batch size, and number of operators) on production capacity, time, and cost were evaluated. Recommendations for decisions concerning cryopreservation pathways and repository creation were given at each scale of production. Relative values of broodstock, juvenile oysters, and oyster sperm sold at hatcheries were also discussed. In general, repositories operating at higher production levels benefited from the economy of scale, could use automated high-throughput equipment options, and could hire more labor without drastically increasing production costs.