Ambient Temperature Influences Diet Selection and Physiology of an Herbivorous Mammal, \u3cem\u3eNeotoma albigula\u3c/em\u3e

The whitethroat woodrat (Neotoma albigula) eats juniper (Juniperus monosperma), but the amount of juniper in its diet varies seasonally. We tested whether changes in juniper consumption are due to changes in ambient temperature and what the physiological consequences of consuming plant secondary compounds (PSCs) at different ambient temperatures might be. Woodrats were acclimated to either 20ºC or 28ºC. Later, they were given two diets to choose from (50% juniper and a nontoxic control) for 7 d. Food intake, resting metabolic rate (RMR), and body temperature (Tb) were measured over the last 2 d. Woodrats at 28ºC ate significantly less juniper, both proportionally and absolutely, than woodrats at 20ºC. RMRs were higher for woodrats consuming juniper regardless of ambient temperature, and Tb was higher for woodrats consuming juniper at 28ºC than for woodrats eating control diet at 28ºC. Thus, juniper consumption by N. albigula is influenced by ambient temperature. We conclude that juniper may influence thermoregulation in N. albigula in ways that are helpful at low temperatures but harmful at warmer temperatures in that juniper PSCs may be more toxic at warmer temperatures. The results suggest that increases in ambient temperature associated with climate change could significantly influence foraging behavior of mammalian herbivores

Experimental evolution on a wild mammal species results in modifications of gut microbial communities

Comparative studies have shown that diet, life history, and phylogeny interact to determine microbial community structure across mammalian hosts. However, these studies are often confounded by numerous factors. Selection experiments offer unique opportunities to validate conclusions and test hypotheses generated by comparative studies. We used a replicated, 15-generation selection experiment on bank voles (Myodes glareolus) that have been selected for high swim-induced aerobic metabolism, predatory behavior toward crickets, and the ability to maintain body mass on a high-fiber, herbivorous diet. We predicted that selection on host performance, mimicking adaptive radiation, would result in distinct microbial signatures. We collected foregut and cecum samples from animals that were all fed the same nutrient-rich diet and had not been subjected to any performance tests. We conducted microbial inventories of gut contents by sequencing the V4 region of the 16S rRNA gene. We found no differences in cecal microbial community structure or diversity between control lines and the aerobic or predatory lines. However, the cecal chambers of voles selected for herbivorous capability harbored distinct microbial communities that exhibited higher diversity than control lines. The foregut communities of herbivorous-selected voles were also distinct from control lines. Overall, this experiment suggests that differences in microbial communities across herbivorous mammals may be evolved, and not solely driven by current diet or other transient factors

rpavirtual: Key lessons in healthcare organisational resilience in the time of COVID-19

The COVID-19 pandemic is an unfolding crisis which is continually testing the resilience of healthcare organisations. In this context, a key requirement for executives, managers and frontline staff is continually adapting, learning and coping with complexity under pressure to deliver high quality and safe care. Sydney Local Health District has responded to the COVID-19 crisis, in part, through the pivoting of rpavirtual, a newly established virtual health service, to deliver an innovative model of care in a clinically rigorous and safe manner. Through reviewing the rapid evolution of rpavirtual's purpose, implementation challenges and impact, we investigate how it has displayed resilience and derive key lessons for health organisations

Primary stenting of the superficial femoral and popliteal artery

ObjectivesOver the last decade, the number of endovascular procedures performed on the superficial femoral (SFA) and popliteal arteries (PA) has significantly increased. There is no consensus on the optimal form of intervention used in this arterial segment. While some have advocated balloon angioplasty alone, others have championed either selective or primary stenting of these lesions. It is the purpose of this study to determine the efficacy and durability of primary stenting of the superficial femoral and popliteal artery.MethodsAll patients undergoing peripheral angioplasty by a single vascular surgeon were prospectively enrolled in an Institutional Review Board-approved, primary-stenting protocol. During a 44-month period, all patients undergoing percutaneous transluminal angioplasty of the SFA or PA also received primary arterial stenting with bare, self-expanding nitinol stents. Patient demographics and risk factors were identified. TransAtlantic InterSociety Consensus (TASC) classifications were determined for all lesions. Loss of primary patency was said to have occurred when an occlusion or a 50% or greater stenosis in any treated arterial segment was diagnosed by arterial duplex or angiography. Only time to loss of primary patency was recorded. Kaplan-Meier survival curves were plotted and differences between groups tested by log rank method.ResultsBetween January 16, 2004 and August 13, 2007, 201 angioplasties with primary stenting were performed on 161 patients. One hundred twenty-three stents were placed for claudication, and 78 for critical limb ischemia. Forty-six segments treated were TASC A, 82 were TASC B, 38 were TASC C, and 35 were TASC D. Patient follow-up ranged from three to 1329 days (mean: 426 days). Primary patency rates for TASC A and B lesions were 79%, 67%, and 57% at 12, 24, and 36 months. For TASC C and D lesions, primary patency rates were 52.7%, 36%, and 19% at the same time intervals. Primary patency rates for TASC A and B lesions were significantly higher than for C and D lesions (P < .001). The limb salvage rate was 88.5% in patients with critical limb ischemia. Distal runoff did not influence patency (P = .827).ConclusionsPrimary stenting of the SFA and PA provides durable results in patients with TASC A and B lesions and may be an effective treatment strategy. This approach is significantly less effective when used in treating those with TASC C and D disease. Based on the results in this series, the use of primary stenting does not extend the anatomic limits of the current treatment recommendations for catheter-based intervention in patients with infrainguinal occlusive disease

Warmer Ambient Temperatures Depress Detoxification and Food Intake by Marsupial Folivores

Ambient temperature is an underappreciated determinant of foraging behaviour in wild endotherms, and the requirement to thermoregulate likely influences food intake through multiple interacting mechanisms. We investigated relationships between ambient temperature and hepatic detoxification capacity in two herbivorous marsupials, the common ringtail possum (Pseudocheirus peregrinus) and common brushtail possum (Trichosurus vulpecula) that regularly feed on diets rich in plant toxins. As an indicator of hepatic detoxification capacity, we determined the functional clearance rate of an anaesthetic agent, Alfaxalone, after possums were acclimated to 10°C [below the thermoneutral zone (TNZ)], 18°C [approximately lower critical temperature (LCT)], and 26°C [approximately upper critical temperature (UCT)] for either 7 days or less than 24 h. We then measured intake of foods with high or low plant secondary metabolite (PSM) concentrations under the same temperature regimes. After 7 days of acclimation, we found a positive correlation between the functional clearance rate of Alfaxalone and ambient temperature, and a negative relationship between ambient temperature and intake of foods with high or low PSM concentrations for both species. The effect of ambient temperature on intake of diets rich in PSMs was absent or reduced when possums were kept at temperatures for less than 24 h. Our results underscore the effects of ambient temperature in hepatic metabolism particularly with respect intake of diets containing PSMs. Given that the planet is warming, it is vital that effects of ambient temperature on metabolism, nutrition and foraging by mammalian herbivores is taken into account to predict range changes of species and their impact on ecosystems

Novel Plant Secondary Metabolites Impact Dietary Specialists More Than Generalists (Neotoma spp.)

Theory predicts that dietary specialization is limited in part because of physiological trade-offs associated with specialization. Specifically, dietary specialists are predicted to evolve mechanisms that reduce costs and enhance excretion of plant secondary metabolites (PSMs) that they frequently consume, but are less energetically and/or mechanistically efficient at eliminating novel PSMs. Although examples of trade-offs associated with dietary specialization have been documented among insects, trade-offs have not been investigated in mammalian herbivores. To initially investigate the physiological trade-offs associated with specialization in mammalian herbivores, we determined the impact of ingesting novel PSMs on the energy budgets of a juniper specialist (Neotoma stephensi) and generalist (N. albigula) woodrat. These results were then compared to the impact of juniper intake, the plant species preferred by the specialist, on energy budgets in these same species. Energy budgets were evaluated by measuring apparent metabolizable energy intake (AMEI, energy consumed 2 energy excreted) and energy expended on basal metabolic rate (BMR) and voluntary wheel running in specialist and generalist woodrats fed a formulated diet with and without PSMs from the novel plant creosote (Larrea tridentata). Both specialists and generalists were energetically impacted by the intake of a diet containing novel PSMs, primarily through decreased intake of creosote diet and increased excretion of energy in the urine. However, specialists were impacted to a greater extent than generalists. Specialists decreased body mass, whereas generalists maintained body mass. Specialists also reduced intake and AMEI when consuming creosote diet compared to control to a greater extent than generalists. In turn, specialists had one-sixth the energy available for energy dependent activities than generalists on a diet containing novel PSMs. These results are in stark contrast to the comparisons between specialists and generalists consuming PSMs from their natural diet. Specialists consumed more juniper, had higher AMEI and available energy than generalists when fed diets containing juniper foliage. These data provide the first support that physiological trade-offs associated with dietary specialization may exist in mammalian herbivores. Key words: generalist; mammalian herbivore; Neotoma albigula; Neotoma stephensi; novel PSM; specialist; trade-off

E-learning as a tool for knowledge transfer through traditional and independent study at two UK higher educational institutes: a case study

Much has been made of the advances in computer aided learning activities. Websites, virtual campus, the increased use of Web CT and chat rooms and further advances in the use of WebCT are becoming more commonplace in UK universities. This paper looks for ways of changing higher education students’ perception of the usefulness of recommended internet web sites for learning purposes, with the intention of increasing the usage rate of recommended module web-sites. The change could represent an adaptation of the existing, well-known technology to change students’ perception regarding its potentially formative role. Subsequently, the outcomes from this preliminary research could be used in order to enhance the quality of the Internet use for teaching and learning purposes

Demographic Differences in Patterns of Youth Out-of-School Time Activity Participation

Participation in structured out-of-school time (OST) activities is of growing interest to families, youth practitioners, and policymakers. OST activities benefit youth socially, emotionally, and academically, especially at-risk youth. Yet, little research has explored the characteristics of youth participants. This study examines whether demographic differences exist merely in getting youth “in the door” of activities, or whether differences persist when examining the number of activities and the amount of time youth spend in activities once they are there. Results from two nationally representative datasets showed that disadvantaged youth were less likely to participate in a variety of activities than their peers, and participated in fewer numbers of activities. Among youth who did participate, Blacks and Hispanics participated less frequently in some activities, although Blacks participated more frequently in community-based youth programs. Implications for recruitment and retention are discussed, including the need for activity leaders to enhance efforts to attract and sustain disadvantaged and ethnic minority youth