The ‘omnivorous badger dilemma’: towards an integration of nutrition with the dietary niche in wild mammals

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Anthropogenic disturbance in a changing environment: modelling lifetime reproductive success to predict the consequences of multiple stressors on a migratory population

Animals make behavioural and reproductive decisions that maximise their lifetime reproductive success, and thus their fitness, in light of periodic and stochastic variability of the environment. Modelling the variation of an individual's energy levels formalises this tradeoff and helps to quantify the population‐level consequences of stressors (e.g. disturbance from human activities and environmental change) that can affect behaviour or physiology. In this study, we develop a dynamic state variable model for the spatially explicit behaviour, physiology and reproduction of a female, long‐lived, migratory marine vertebrate. The model can be used to investigate the spatio‐temporal patterns of behaviour and reproduction that allow an individual to maximise its overall reproductive output. We parametrised the model for eastern North Pacific blue whales Balaenoptera musculus, and used it to predict the effects of changing environmental conditions and increasing human disturbance on the population's vital rates. In baseline conditions, the model output had high fidelity to observed energy dynamics, movement patterns and reproductive strategies. Simulated scenarios suggested that environmental changes could have severe consequences on the population's vital rates, but that individuals could tolerate high levels of anthropogenic disturbance. However, this ability depended on where, when and how often disturbance occurred. In scenarios with both environmental change and anthropogenic disturbance, synergistic interactions caused stronger effects than in isolation. In general, larger body size offered a buffer against stochasticity and disturbance, and, consequently, we predicted juveniles to be more susceptible to disturbance. We also predicted that females prioritise their own survival at the expense of the current reproductive attempt, presumably the result of their long lifespan. Our approach provides a general framework to make predictions of the cumulative and synergistic effects of human disturbance and climate change on migratory populations, which can inform effective management and conservation efforts.     

Nurses who work rotating shifts consume more energy,macronutrients and calcium when they work the night shift versus day shift

Background: Shift work has been associated with increased body mass index (BMI), metabolic disruption and increased chronic disease risk. Typically, these reports compare individuals who work the day shift to those who work the night shift. Because shift assignment is not random, differences may reflect other, unmeasured characteristics that account for outcome differences.

Objective: To compare dietary intake on days on which the participant worked the night shift to days on which she worked the day shift in a population of female nurses who work rotating shifts at a hospital.

Methods: This cross-sectional study recruited 132 female registered nurses who work rotating shifts in surgical or internal medicine departments. Dietary intake was ascertained using food diaries and analyzed on Tzameret Nutrition Analysis Software (Israel Ministry of Health). Demographic and anthropometric variables were also recorded.

Results: Compared to dietary intake on a day the nurse worked the day shift, intake of the following nutrients increased significantly on the day she worked the night shift: energy; protein; carbohydrates; total fat; saturated fat; and calcium.

Discussion: A significant increase in calorie, macronutrient and calcium intake on days the night shift was worked compared to days the day shift was worked among female nurses who work rotating shifts was demonstrated. These findings could be extended to other professionals who work rotating shifts, including physicians and allied healthcare personnel. It appears that the difference detected may be influenced by the food supplied by the hospital as well as by increased food intake in general.     

Multifunctionality debt in global drylands linked to past biome and climate

Past vegetation and climatic conditions are known to influence current biodiversity patterns. However, whether their legacy effects affect the provision of multiple ecosystem functions, that is, multifunctionality, remains largely unknown. Here we analyzed soil nutrient stocks and their transformation rates in 236 drylands from six continents to evaluate the associations between current levels of multifunctionality and legacy effects of the Last Glacial Maximum (LGM) desert biome distribution and climate. We found that past desert distribution and temperature legacy, defined as increasing temperature from LGM, were negatively correlated with contemporary multifunctionality even after accounting for predictors such as current climate, soil texture, plant species richness, and site topography. Ecosystems that have been deserts since the LGM had up to 30% lower contemporary multifunctionality compared with those that were nondeserts during the LGM. In addition, ecosystems that experienced higher warming rates since the LGM had lower contemporary multifunctionality than those suffering lower warming rates, with a ~9% reduction per extra degree Celsius. Past desert distribution and temperature legacies had direct negative effects, while temperature legacy also had indirect (via soil sand content) negative effects on multifunctionality. Our results indicate that past biome and climatic conditions have left a strong “functionality debt” in global drylands. They also suggest that ongoing warming and expansion of desert areas may leave a strong fingerprint in the future functioning of dryland ecosystems worldwide that needs to be considered when establishing management actions aiming to combat land degradation and desertification.     

Dietary fatty acid profile influences circulating and tissue fatty acid ethanolamide concentrations in a tissue-specific manner in male Syrian hamsters

BackgroundThe discovery of N‑acylethanolamines (NAEs) has prompted an increase in research aimed at understanding their biological roles including regulation of appetite and energy metabolism. However, a knowledge gap remains to understand the effect of dietary components on NAE levels, in particular, heterogeneity in dietary fatty acid (DFA) profile, on NAE levels across various organs.ObjectiveTo identify and elucidate the impact of diet on NAE levels in seven different tissues/organs of male hamsters, with the hypothesis that DFA will act as precursors for NAE synthesis in golden Syrian male hamsters.MethodA two-month feeding trial was performed, wherein hamsters were fed various dietary oil blends with different composition of 18-C fatty acid (FA).ResultsDFA directly influences tissue FA and NAE levels. After C18:1n9-enriched dietary treatments, marked increases were observed in duodenal C18:1n9 and oleoylethanolamide (OEA) concentrations. Among all tissues; adipose tissue brown, adipose tissue white, brain, heart, intestine-duodenum, intestine-jejunum, and liver, a negative correlation was observed between gut-brain OEA concentrations and body weight.ConclusionDFA composition influences FA and NAE levels across all tissues, leading to significant shifts in intestinal-brain OEA concentrations. The endogenously synthesized increased OEA levels in these tissues enable the gut-brain-interrelationship. Henceforth, we summarize that the brain transmits anorexic properties mediated via neuronal signalling, which may contribute to the maintenance of healthy body weight. Thus, the benefits of OEA can be enhanced by the inclusion of C18:1n9-enriched diets, pointing to the possible nutritional use of this naturally occurring bioactive lipid-amide in the management of obesity.     

香栓菌的平喘及抗氧化活性研究

本文对香栓菌子实体提取物的平喘作用和抗氧化活性进行研究。平喘药理实验采用鸡卵清蛋白（OVA）致敏法建立小鼠过敏性哮喘模型,灌胃给药香栓菌水提物（高240mg/kg、中120mg/kg、低60mg/kg剂量）和石油醚提取物（高24mg/kg、中12mg/kg、低6mg/kg剂量）。比较各组小鼠行为变化,检测IgE、TNF-α、IL-1β、IL-6、IL-4和IFN-γ等指标,分类计数血液及支气管肺泡灌洗液（BALF）中的嗜酸性粒细胞数量,分析肺组织病理变化;抗氧化实验采用香栓菌水提取物、乙酸乙酯提取物、氯仿提取物、石油醚提取物比较清除DPPH和ABTS自由基能力。平喘试验结果表明,香栓菌水提物中剂量（120mg/kg）能降低血中嗜酸性粒细胞（Eos）及血清中IgE含量,减少BALF中Eos,降低血清及肺组织匀浆中IL-4含量,提高IFN-γ/IL-4,减轻模型的病理改变;石油醚提取物高剂量（24mg/kg）能降低血中Eos和血清中IgE、TNF-α、IL-1、IL-6含量,减少肺组织炎症细胞浸润;抗氧化结果显示,香栓菌各层提取物均有不同程度的抗氧化能力,并呈现一定的量效关系,同时水提取物的抗氧化效果最显著。本文为深入研究香栓菌子实体对呼吸系统疾病的治疗提供了重要试验依据。     

Effects of late gestation shearing on BW,feed intake and plasma metabolite concentrations in Rambouillet ewes managed outdoors during winter

The majority of lambs in the United States are born from late winter to early spring and pregnant ewes are generally sheared in the last third of pregnancy. Although there are benefits to shearing before parturition, shorn animals may be more vulnerable to the cold, highly variable climatic conditions associated with these seasons. The objective of this study was to determine if late gestation shearing induces differences in individual BW, dry matter intake (DMI) and plasma metabolite concentration of finewool ewes managed outdoors during winter. Thirty-six mature, pregnant Rambouillet ewes (3.8±0.45 years; 76.8±11.4 kg) were managed in a drylot with ad libitum access to pelleted alfalfa in bunks capable of measuring individual daily DMI. The treatment group consisted of ewes sheared at ~5 weeks before the estimated parturition date (shorn; n=18). Unshorn ewes (n=18) remained in full fleece throughout the experiment and were shorn on the last day of the experiment ~2 weeks before the estimated parturition date. Blood was collected on days 0 (before shearing shorn group), 7, 14 and 21 (before shearing unshorn group) of the trial, and plasma was isolated and analyzed for non-esterified fatty acid (NEFA), β-hydroxybutyrate (BHB) and glucose (GLU) concentrations. There was no effect of shearing on ewe DMI or BW during the trial (P⩾0.35). Plasma NEFA and GLU concentrations were similar (P⩾0.36) between shearing groups, though plasma BHB concentration was 103.7 μmol/l greater (24.1%; P<0.01) in unshorn ewes. Lamb BW at birth was not affected (P=0.30) by ewe shearing treatment. Under conditions of this study, no differences in economically important aspects of sheep production were observed between shorn and unshorn pregnant ewes.     

Effect of lactation trimester and parity on eating behavior,milk production and efficiency traits of dairy cows

There is absence knowledge about the effects of lactation trimester and parity on eating behavior, production and efficiency of dairy cows. Objective of this study was to identify and characterize in 340 dairy cows, the 20% high efficient (HE), 20% low efficient (LE) and 60% mid efficient (ME) cows according to their individual residual feed intake (RFI) values, within and between lactation trimesters and between 1st and 2nd parities. Efficiency effect within each lactation trimester, was exhibited in daily dry matter intake (DMI), eating rate and meal size, that were the highest in LE cows, moderate in the ME cows and lowest in the HE group. Daily eating time, meal frequency, yields of milk and energy-corrected milk (ECM) and BW were similar in the three efficiency groups within each trimester. The lower efficiency of the LE cows in each trimester attributes to their larger metabolic energy intake, heat production and energy losses. In subgroup of 52 multiparous cows examined along their 1st and 2nd trimesters, milk and ECM production, DMI, eating behavior and efficiency traits were similar with high Pearson’s correlation (r=0.78 to 0.89) between trimesters. In another subgroup of 42 multiparous cows measured at their 2nd and 3rd trimesters, milk and ECM yield, DMI and eating time were reduced (P<0.01) at the 3rd trimester, but eating rate, meal frequency and meal size remained similar with high Pearson’s correlation (r=0.74 to 0.88) between trimesters. In subgroup of 26 cows measured in 1st and 2nd parities, DMI, BW, milk and ECM yield, and ECM/DMI increased in the 2nd lactation, but eating behavior and RFI traits were similar in both parities. These findings encourage accurate prediction of DMI based on a model that includes eating behavior parameters, together with individual measurement of ECM production. This can be further used to identify HE cows in commercial herd, a step necessary for potential genetic selection program aimed to improve herd efficiency.     

Elevational differentiation accelerates trait evolution but not speciation rates in Amazonian birds

The importance of ecologically mediated divergent selection in accelerating trait evolution has been poorly studied in the most species‐rich biome of the planet, the continental Neotropics. We performed macroevolutionary analyses of trait divergence and diversification rates across closely related pairs of Andean and Amazonian passerine birds, to assess whether the difference in elevational range separating species pairs – a proxy for the degree of ecological divergence – influences the speed of trait evolution and diversification rates. We found that elevational differentiation is associated with faster divergence of song frequency, a trait important for pre‐mating isolation, and several morphological traits, which may contribute to extrinsic post‐mating isolation. However, elevational differentiation did not increase recent speciation rates, possibly due to early bursts of diversification during the uplift of the eastern Andes followed by a slow‐down in speciation rate. Our results suggest that ecological differentiation may speed up trait evolution, but not diversification of Neotropical birds.