Weather, not climate, defines distributions of vagile bird species

Background

Accurate predictions of species distributions are essential for climate change impact assessments. However the standard practice of using long-term climate averages to train species distribution models might mute important temporal patterns of species distribution. The benefit of using temporally explicit weather and distribution data has not been assessed. We hypothesized that short-term weather associated with the time a species was recorded should be superior to long-term climate measures for predicting distributions of mobile species.

Methodology

We tested our hypothesis by generating distribution models for 157 bird species found in Australian tropical savannas (ATS) using modelling algorithm Maxent. The variable weather of the ATS supports a bird assemblage with variable movement patterns and a high incidence of nomadism. We developed “weather” models by relating climatic variables (mean temperature, rainfall, rainfall seasonality and temperature seasonality) from the three month, six month and one year period preceding each bird record over a 58 year period (1950–2008). These weather models were compared against models built using long-term (30 year) averages of the same climatic variables.

Conclusions

Weather models consistently achieved higher model scores than climate models, particularly for wide-ranging, nomadic and desert species. Climate models predicted larger range areas for species, whereas weather models quantified fluctuations in habitat suitability across months, seasons and years. Models based on long-term climate averages over-estimate availability of suitable habitat and species'' climatic tolerances, masking species potential vulnerability to climate change. Our results demonstrate that dynamic approaches to distribution modelling, such as incorporating organism-appropriate temporal scales, improves understanding of species distributions.     

Phylogeography of the banded killifish (Fundulus diaphanus): glacial races and secondary contact

Spatial patterns of morphological and genetic polymorphisms between the two banded killifish sub-species ( Fundulus diaphanus diaphanus and F. d. menona ) provide evidence that these sub-species represent distinct evolutionary lineages corresponding to glacial races of Atlantic and Mississippian origins. Individuals with intermediate phenotypes in Lake Ontario and the upper St Lawrence River probably result from secondary contacts between these races. The hybrid zone unexpectedly extends to Lake Erie and involves the introgression of the F. d. diaphanus mitochondrial genome into fish with morphology like that of F. d. menona .     

Use of temperature telemetry to monitor ingestion by a harbour seal mother and her pup throughout lactation

The applicability of using stomach temperature telemetry to detect and estimate milk intake throughout lactation was investigated in harbour seals (Phoca vitulina). Observations of a mother-pup pair were conducted daily while stomach temperature was concurrently logged. Milk intake caused a decrease in the pup's stomach temperature. The duration of stomach temperature change was related to the length of the nursing bout (r ²=0.82, P<0.001). Laboratory stomach simulations suggested a strong relationship between milk volume and duration of temperature change (r ²=0.98, P<0.001). This relationship was used to estimate the volume of milk consumed by the pup. Suckling bout length and the estimated milk intake per bout increased, as a weekly average, with pup age (one-way ANOVA; F _3.67=11.66, P<0.001) over the 5-week lactation period. A diel change in nursing time was noted, with a transition from largely nocturnal to daytime feedings. Although not visually confirmed, stomach temperature data collected from the mother provided evidence of seawater ingestion. Methods that could improve estimates of milk intake are discussed. Stomach temperature telemetry proved to be a useful technique for detecting ingestion events in harbour seals, and may provide a valuable tool for investigating lactation energetics and aspects of maternal investment in a variety of nursing species.     

Gas chromatographic method using photoionization detection for the determination of breath pentane

Lipid peroxidation is thought to be an important event in the pathogenesis of atherosclerosis. It has been suggested that pentane, which can be formed during the oxidation of ω-6 fatty acids, is a marker of lipid peroxidation. Previous studies have reported elevated breath pentane and serum markers of lipid peroxidation in smokers. However, chromatographic separation of pentane from isoprene in virtually all of these studies was incomplete and the methods used did not resolve pentane into its isomers, n-pentane and isopentane. Additionally, most current methods are complicated, requiring trapping and concentrating steps to obtain adequate sensitivity prior to hydrocarbon analysis. The purpose of the current study was to develop a gas chromatographic system to analyze breath pentane, that addressses the above technical problems and that would provide a simple in vivo method for measuring lipid. n-Pentane and isopentane standards were easily separated from isoprene with a Al₂O₃/KCl capillary column contained in a portable gas chromatograph equipped with a photoionization detector. The analysis of repeated measures showed a low coefficient of variation for measurements of n-pentane (10%) and isopentane (9%). We measured breath pentane in 27 subjects (15 smokers, 12 non-smokers). There were no significant difference between the baseline and 4 week interval measurements of n-pentane for smokers both before and after cigarette smoking. The within-subject variability data showed that the assay is highly reproducible for both low and high pentane levels in smokers. Smokers were found to have higher levels of both n-pentane and isopentane than non-smokers (P<0.001). In addition, smokers had further significant elevation of pentane levels 10 min after smoking (P<0.001), which returned to baseline by 1 h. These studies demonstrate that measurement of breath pentane, using a gas chromatograph with a photoionization detector, is simple and reproducible. Additionally, these results suggest that pentane elevation associated with smoking is secondary to the oxidant effects of cigarette smoke and an important temporal relationship exists between cigarette smoking and breath sample analysis.     

Do All Dogs Go to Heaven? Investigating the Association between Demographic Characteristics and Beliefs about Animal Afterlife

The purpose of this research was to explore American’s beliefs about animal afterlife based on key demographic factors such as sex, race/ethnicity, age, geographic region, religion/faith, and pet ownership. We attained a large and diverse sample of respondents (n = 800) using Amazon’s Mechanical Turk, and attempted to make the data fairly representative of the United States population by applying post-stratification weights based on auxiliary statistics obtained from US Census data. Results of the study suggest that many people perceive animal lives as similarly sacred as human lives. Evidence also suggests that one’s membership in a particular demographic category may have considerable bearing on views about animal afterlife. The authors recommend veterinarians remain cognizant that some people extend their own views on issues such as spirituality to their pets and those beliefs and values can impact veterinary care and decision-making.     

How to make stone soup: Is the “Paleo diet” a missed opportunity for anthropologists?

For the past few years, people everywhere have been “going Paleo.” Websites and social media touting the benefits of eating a “Paleo diet” and following a “Paleolithic life style” serve as calls to arms for health‐conscious individuals seeking information about the latest health and fitness trends. Many of these people participate in programs such as Crossfit, which involve major social and life‐style modification components and therefore facilitate the dissemination of dietary fads.¹ The PALEOf(x)^TM conference, which bills itself as “the world's premier holistic wellness event,” has attracted sellout crowds of thousands of attendees for the last four years.² Consumers can wear Paleo clothing, download Paleo shopping and exercise apps to their smartphones, order prepackaged Paleo food, prepare it using Paleo cooking implements, or expediently buy Paleo convenience foods from Paleodiet? vending machines³ and “Cultured Caveman” food trucks.⁴ The Paleo diet is touted by movie stars, reality TV personalities, and professional athletes, including LeBron James and the entire Miami Dolphins NFL team.^5,6 Books with titles such as The Primal Blueprint,⁷ Cavewomen Don't Get Fat,⁸ and Paleo Perfected⁹ (the latter by the stodgy America's Test Kitchen) are legion, and many are bestsellers.     

Functional Impact of Corticotropin-Releasing Factor Exposure on Tau Phosphorylation and Axon Transport

Stress exposure or increased levels of corticotropin-releasing factor (CRF) induce hippocampal tau phosphorylation (tau-P) in rodent models, a process that is dependent on the type-1 CRF receptor (CRFR1). Although these preclinical studies on stress-induced tau-P provide mechanistic insight for epidemiological work that identifies stress as a risk factor for Alzheimer’s disease (AD), the actual impact of stress-induced tau-P on neuronal function remains unclear. To determine the functional consequences of stress-induced tau-P, we developed a novel mouse neuronal cell culture system to explore the impact of acute (0.5hr) and chronic (2hr) CRF treatment on tau-P and integral cell processes such as axon transport. Consistent with in vivo reports, we found that chronic CRF treatment increased tau-P levels and caused globular accumulations of phosphorylated tau in dendritic and axonal processes. Furthermore, while both acute and chronic CRF treatment led to significant reduction in CREB activation and axon transport of brain-derived neurotrophic factor (BDNF), this was not the case with mitochondrial transport. Acute CRF treatment caused increased mitochondrial velocity and distance traveled in neurons, while chronic CRF treatment modestly decreased mitochondrial velocity and greatly increased distance traveled. These results suggest that transport of cellular energetics may take priority over growth factors during stress. Tau-P was required for these changes, as co-treatment of CRF with a GSK kinase inhibitor prevented CRF-induced tau-P and all axon transport changes. Collectively, our results provide mechanistic insight into the consequences of stress peptide-induced tau-P and provide an explanation for how chronic stress via CRF may lead to neuronal vulnerability in AD.     

Year-long assessment of airborne endotoxin at a concentrated dairy operation

In this study, we monitored total airborne endotoxins at upwind and downwind sites at a large open-lot dairy each month for a year. At the upwind site, the average airborne concentration was 28.5 endotoxin units (EU) m⁻³, while at the downwind edge of the lot and 200 m from the lot edge, the average concentrations were 169 and 72 EU m⁻³, respectively. At the downwind edge of the lot, there was a significant correlation between the airborne endotoxin concentration and wind speed or air temperature. A comparison between total and inhalable airborne endotoxin concentrations, near the end of the study, revealed no significant differences between the two endotoxin collection methods. Our data suggest that endotoxin exposure can be reduced as one increases their distance from the open-lot dairy.