Determinants of spring migration departure dates in a New World sparrow: Weather variables reign supreme.

Numerous factors influence the timing of spring migration in birds, yet the relative importance of intrinsic and extrinsic variables on migration initiation remains unclear. To test for interactions among weather, migration distance, parasitism, and physiology in determining spring departure date, we used the Dark-eyed Junco (Junco hyemalis) as a model migratory species known to harbor diverse and common haemosporidian parasites. Prior to spring migration departure from their wintering grounds in Indiana, USA, we quantified the intrinsic variables of fat, body condition (i.e., mass ~ tarsus residuals), physiological stress (i.e., ratio of heterophils to lymphocytes), cellular immunity (i.e., leukocyte composition and total count), migration distance (i.e., distance to the breeding grounds) using stable isotopes of hydrogen from feathers, and haemosporidian parasite intensity. We then attached nanotags to determine the timing of spring migration departure date using the Motus Wildlife Tracking System. We used additive Cox proportional hazard mixed models to test how risk of spring migratory departure was predicted by the combined intrinsic measures, along with meteorological predictors on the evening of departure (i.e., average wind speed and direction, relative humidity, and temperature). Model comparisons found that the best predictor of spring departure date was average nightly wind direction and a principal component combining relative humidity and temperature. Juncos were more likely to depart for spring migration on nights with largely southwestern winds and on warmer and drier evenings (relative to cooler and more humid evenings). Our results indicate that weather conditions at take-off are more critical to departure decisions than the measured physiological and parasitism variables.

Novel Rickettsia spp. in two common overwintering North American songbirds.

American robins and dark-eyed juncos migrate across North America and have been found to be competent hosts for some bacterial and viral pathogens, but their contributions to arthropod-borne diseases more broadly remain poorly characterized. Here, we sampled robins and juncos in multiple sites across North America for arthropod-borne bacterial pathogens of public health significance. We identified two novel Rickettsia spp. in one wintering migrant per bird species related to bellii, transitional, and spotted rickettsiae fever groups. Stable isotope analyses of feathers suggested spring migration of these common songbirds could disperse these novel rickettsiae hundreds-to-thousands of kilometers to host breeding grounds. Further work is needed to characterize zoonotic potential of these rickettsiae and host reservoir competence.

Artificial light at night amplifies seasonal relapse of haemosporidian parasites in a widespread songbird.

Urban habitats can shape interactions between hosts and parasites by altering not only exposure rates but also within-host processes. Artificial light at night (ALAN) is common in urban environments, and chronic exposure can impair host immunity in ways that may increase infection. However, studies of causal links between this stressor, immunity, and infection dynamics are rare, particularly in migratory animals. Here, we experimentally tested how ALAN affects cellular immunity and haemosporidian parasite intensity across the annual cycle of migrant and resident subspecies of the dark-eyed junco (Junco hyemalis). We monitored an experimental group exposed to light at night and a control group under natural light/dark cycles as they passed through short days simulating early spring to longer days simulating the breeding season, followed by autumn migration. Using generalized additive mixed models, we show that ALAN increased inflammation, and leucocyte counts were greatest in early spring and autumn. At the start of the experiment, few birds had active infections based on microscopy, but PCR revealed many birds had chronic infections. ALAN increased parasitaemia across the annual cycle, with strong peaks in spring and autumn that were largely absent in control birds. As birds were kept in indoor aviaries to prevent vector exposure, this increased parasitaemia indicates relapse of chronic infection during costly life-history stages (i.e. reproduction). Although the immunological and parasitological time series were in phase for control birds, cross-correlation analyses also revealed ALAN desynchronized leucocyte profiles and parasitaemia, which could suggest a general exaggerated inflammatory response. Our study shows how a common anthropogenic influence can shape within-host processes to affect infection dynamics.

Effects of Music Therapy During Total Knee Arthroplasty Under Spinal Anesthesia: A Prospective Randomized Controlled Study.

Purpose Music therapy is an effective non-pharmacologic intervention that is cost-effective, easy to implement, and customize. It has been shown to significantly alleviate anxiety and improve patient satisfaction. In this study, we aimed to compare music therapy to a control (no music) group with respect to sedation requirements, anxiety levels, and patient satisfaction for patients undergoing total knee arthroplasty under spinal anesthesia. Methods In this randomized controlled study, we compared the effect of music therapy in patients ≥ 18 years old. Patients undergoing total knee arthroplasty were screened for the study to rule out any contraindications for spinal anesthesia. Patients were randomized in a 1:1 ratio for either the "music" or "control" group. Both groups were compared for sedation requirements, preoperative and postoperative anxiety levels, and patient satisfaction. Results Subjects in the music group had a statistically significant lower than average State-Trait Anxiety Inventory (STAI)-State baseline score as compared to the control group (music group 31.00 (standard deviation (SD) 1.44), control group 38.04 (SD 2.35); p = 0.01). Postoperative STAI-State-Trait Anxiety Inventory (STAI)-State scores for the music group were lower for the music group than the control group (music group 28.34 (SD 1.64), control group 32.21 (SD 1.56), p= 0.09). STAI-Trait scores were similar pre-operatively, but significantly less post-operatively in the music group (28.14 SD 1.0) as compared to the control group (34.71 SD 2.31); p = 0.01. Propofol dose per kilogram per surgical minute was similar between the two groups (music group 0.05, control group 0.06; p= 0.264). Patient satisfaction scores with their perioperative experience were higher in the music group (p= 0.009). Conclusions Music therapy may be offered as an alternative to traditional anxiolytics intra-operatively. However further studies are warranted to evaluate whether or not music therapy can decrease sedation and anxiolytic medications during surgery. The type and mode of delivery of music also need to be studied to better understand the impact of music therapy. Clinical trial registry: Clinicaltrials.gov # NCT03569397.

Factors influencing detection and co-detection of Ranavirus and Batrachochytrium dendrobatidis in Midwestern North American anuran populations.

Amphibian populations are in decline worldwide as they face a barrage of challenges, including infectious diseases caused by ranaviruses and the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Here we describe seasonal dynamics of Bd and ranavirus detection in free-ranging post-metamorphic wood frogs Lithobates sylvaticus, boreal chorus frogs Pseudacris maculata/triseriata, and gray treefrogs Hyla versicolor/chrysoscelis, sampled over a 3 season gradient in Minnesota (USA) wetlands. We detected Bd in 36% (n = 259) of individuals sampled in 3 wetlands in 2014, and 33% (n = 255) of individuals sampled in 8 wetlands in 2015. We also detected ranavirus in 60% and 18% of individuals sampled in 2014 and 2015, respectively. Ranavirus and Bd were detected concurrently in 26% and 2% of animals sampled in 2014 and 2015, respectively. We report clinical signs and associated infection status of sampled frogs; of the clinical signs observed, skin discoloration was significantly associated with ranavirus infection. Using generalized estimating equations, we found that species, season, wetland, and a species × season interaction term were significant predictors of Bd detection, whereas test year approached significance as a predictor of ranavirus detection. The odds of detecting both pathogens concurrently was significantly influenced by species, season, a species × season interaction term, year, and environmental ammonia. We propose an amphibian health monitoring scheme that couples population size surveys with seasonal molecular surveys of pathogen presence. This information is crucial to monitoring the health of remaining strongholds of healthy amphibian populations, as they face an uncertain future of further anthropogenic change.

Risk of disease progression in patients with moderate asymptomatic carotid artery stenosis: implications of tobacco use and dual antiplatelet therapy.

BACKGROUND: Because of improved medical therapy in contemporary practice, some have advocated that, most if not, all patients with asymptomatic carotid disease should be managed medically without intervention. Disease progression in this patient population is not well established, and data describing risk factors for disease progression in patients with moderate asymptomatic carotid artery stenosis (ASCAS) are lacking. The aim of our study was to determine the incidence of and risk factors for disease progression in this patient population. METHODS: All patients presenting to a tertiary center between January 2005 and May 2012 with moderate (50-69%) ASCAS as determined by carotid artery duplex were included. Outcomes including disease progression to severe stenosis (≥70%), incidence of symptoms, need for operative intervention, and all-cause mortality were recorded. Cox proportional hazard regression models were used to identify risk factors for disease progression. RESULTS: A total of 282 carotid arteries in 258 patients with moderate ASCAS were identified from 1555 carotid duplex scans over the 7.5-year study period (mean age: 70.6 ± 0.55 years, 52% male). Mean follow-up time was 2.6 ± 0.10 years. Overall, disease progression to severe stenosis occurred in 25.2% (n = 71) and followed a linear trend. The incidence of symptoms including ipsilateral stroke (2.13%, n = 6) and transient ischemic attack (0.71%; n = 2) was low. Carotid endarterectomy was performed in 15.3% (n = 43) of patients, all with severe disease. Carotid stenting was performed in 3.90% (n = 11) patients. Risk of progression was higher in patients receiving dual antiplatelet therapy (Hazard Ratio [HR] 1.85, 95% confidence interval [CI] 1.09-3.15; P = 0.02) and smokers (HR 1.85, 95% CI 0.96-3.55; P = 0.05). Age, gender (women), hypertension, statin use, and aspirin use were not significant predictors of progression to severe stenosis. There was a nonsignificant trend toward increased mortality in patients who progressed compared with those who did not (HR 3.39, 95% CI 0.91-12.6; P = 0.07). CONCLUSIONS: In our study, one-quarter of patients with moderate ASCAS progressed to severe disease, although the majority remained asymptomatic. Smoking and dual antiplatelet therapy are independent risk factors for disease progression. Patients with identifiable risk factors may warrant more careful follow-up.