Diffusion and Home Range Parameters from Rodent Population Measurements in Panama

Simple random walk considerations are used to interpret rodent population data collected in Hantavirus-related investigations in Panama regarding the short-tailed cane mouse, \emph{Zygodontomys brevicauda}. The diffusion constant of mice is evaluated to be of the order of (and larger than) 200 meters squared per day. The investigation also shows that the rodent mean square displacement saturates in time, indicating the existence of a spatial scale which could, in principle, be the home range of the rodents. This home range is concluded to be of the order of 70 meters. Theoretical analysis is provided for interpreting animal movement data in terms of an interplay of the home ranges, the diffusion constant, and the size of the grid used to monitor the movement. The study gives impetus to a substantial modification of existing theory of the spread of the Hantavirus epidemic which has been based on simple diffusive motion of the rodents, and additionally emphasizes the importance for developing more accurate techniques for the measurement of rodent movement.Comment: 18 pages, 5 figure

One-degree-of-freedom motion induced by modeled vortex shedding

The motion of an elastically supported cylinder forced by a nonlinear, quasi-static, aerodynamic model with the unusual feature of a motion-dependent forcing frequency was studied. Numerical solutions for the motion and the Lyapunov exponents are presented for three forcing amplitudes and two frequencies (1.0 and 1.1 times the Strouhal frequency). Initially, positive Lyapunov exponents occur and the motion can appear chaotic. After thousands of characteristic times, the motion changes to a motion (verified analytically) that is periodic and damped. This periodic, damped motion was not observed experimentally, thus raising questions concerning the modeling

The Price of Surviving on Adrenaline: Developmental Programming Responses to Chronic Fetal Hypercatecholaminemia Contribute to Poor Muscle Growth Capacity and Metabolic Dysfunction in IUGR-Born Offspring

Maternofetal stress induces fetal programming that restricts skeletal muscle growth capacity and metabolic function, resulting in intrauterine growth restriction (IUGR) of the fetus. This thrifty phenotype aids fetal survival but also yields reduced muscle mass and metabolic dysfunction after birth. Consequently, IUGR-born individuals are at greater lifelong risk for metabolic disorders that reduce quality of life. In livestock, IUGR-born animals exhibit poor growth efficiency and body composition, making these animals more costly and less valuable. Specifically, IUGR-associated programming causes a greater propensity for fat deposition and a reduced capacity for muscle accretion. This, combined with metabolic inefficiency, means that these animals produce less lean meat from greater feed input, require more time on feed to reach market weight, and produce carcasses that are of less quality. Despite the health and economic implications of IUGR pathologies in humans and food animals, knowledge regarding their specific underlying mechanisms is lacking. However, recent data indicate that adaptive programing of adrenergic sensitivity in multiple tissues is a contributing factor in a number of IUGR pathologies including reduced muscle mass, peripheral insulin resistance, and impaired glucose metabolism. This review highlights the findings that support the role for adrenergic programming and how it relates to the lifelong consequences of IUGR, as well as how dysfunctional adrenergic signaling pathways might be effective targets for improving outcomes in IUGR-born offspring

A Study of Ozone at Railroad Valley, NV and Trinidad Head, CA

A STUDY OF OZONE AT RAILROAD VALLEY, NV and TRINIDAD HEAD, CA Ozone (Oᴣ) is a form of oxygen that protects the planet Earth from deadly ultraviolet rays emitted by the sun; without this triatomic molecule high in the atmosphere, life processes on the planet would be impossible. Ozone is an air pollutant and toxic in the lowest part of the atmosphere, and inhaling it could cause permanent damage to animals’ respiratory system. Long term exposure to high concentration of ozone has been linked with the development of asthma in children. Because of its complicated role in our atmosphere, scientists are studying its depletion and recovery in the stratosphere, and the minimization of ozone formation in the atmospheric boundary layer (the lowest part of the atmosphere). Here at NASA Ames Research Center (ARC), the Atmospheric Branch of Earth Science Division is conducting a study to examine and compare ozone concentrations in the atmospheric boundary layer (0 to ~2 km above the surface of the Earth) to those of the free troposphere (~2 km to ~10 km, where regional transport occurs), and to validate the accuracy of the ozone instrument used in the experiment. Using a 2BTechnology, Inc., Dual Beam Ozone Monitor installed inside the wing pod of an Alpha jet aircraft based at Moffett Field vertical profiles of ozone concentrations have been collected at Trinidad Head, California, and Railroad Valley (RRV), Nevada. The airborne data at Trinidad Head are also compared to standard measurements collected by the National Atmospheric and Oceanic Administration (NOAA) using a balloonborne DMT Electrochemical Concentration Cell Ozonesonde. My area of research is to support the calibration of the ozone instrument, to aggregate ozone measurements, and to analyze data collected from the three subject locations

Ractopamine HCl improved cardiac hypertrophy but not poor growth, metabolic inefficiency, or greater white blood cells associated with heat stress in concentrate-fed lambs

Heat stress decreases livestock performance and well-being (Hahn, 1999; Nienaber and Hahn, 2007), causes metabolic dysfunction that decreases growth efficiency (O’Brien et al., 2010), and alters cardiovascular function (Crandall et al., 2008). Each year, heat stress costs the livestock industry up to $2.5 billion (St-Pierre et al., 2003). Ractopamine HCl acts as a nutrient repartitioning agent (Beermann, 2002); classified as a β adrenergic agonist (βAA), it shares pharmacological properties with adrenaline (Beermann, 2002). βAA increase muscle mass and decreases fat deposition through unknown mechanisms (Beermann, 2002). In feedlot cattle, they increase growth efficiency and improve carcass yield and merit (Scramlin et al., 2010; Buntyn et al., 2017), which increases profit and allows more meat to be produced from fewer animals. However, because βAA act via a stress system, it is unclear how the products affect animals under stress conditions. β1AA and β2AA can also cause tachycardia, heart palpitations, and arrhythmias (Sears, 2002). We hypothesize that β1AA combined with heat stress may overstimulate the adrenergic system, resulting is metabolic dysfunction and decreased performance. Sheep are a common model for cattle, and thus, the objective of this study was to determine the impact of ractopamine HCl on health and cardiovascular parameters, growth, and metabolic efficiency in feeder lambs

'Grey nomad' travellers' use of remote health services in Australia: a qualitative enquiry of hospital managers' perspectives.

BACKGROUND: For more than the last two decades, older Australians travelling domestically in self-sufficient accommodation and recreational vehicles for extended periods of time have been referred to as 'Grey Nomads'. By 2021 more than 750,000 such recreational vehicles were registered in Australia. Tourism data for the year to September 2017 show 11.8 million domestic camping and caravanning trips in Australia, 29% of which were people aged 55 and over. As the 'baby boomer' generation increasingly comes to retirement, the size of this travelling population is growing. This term applies to the spike in birth rates after World War II from 1946-1964. This growing group of domestic travellers are potential healthcare consumers in remote areas but relatively little is known about their travel, healthcare needs or care seeking practices. Grey nomads have been described as reflective of the age-comparable sector of the Australian population in that many live with chronic illness. Early concerns were raised that they may "burden" already stretched rural and remote healthcare services but relatively little is known about the impact of these travellers. METHODS: The aim of this study was to explore the utilisation of healthcare services in remote locations in Australia by grey nomads including women travellers, from the perspective of healthcare professionals working in these settings. The study objective was to interview healthcare professionals to seek their experience and details of service delivery to grey nomads. In March 2020 [prior to state border closures due to the COVID-19 pandemic] a field study was conducted to identify the impact of grey nomads on healthcare services in remote New South Wales and Queensland. A qualitative approach was taken to explore the perspectives of nursing healthcare managers working in remote towns along a popular travel route. With appropriate Research Ethics Committee approval, managers were purposively sampled and sample size was determined by data saturation. Thirteen managers were contacted and twelve interviews were scheduled to take place face to face in the healthcare facilities (small hospitals with acute care and aged care services) at mutually convenient times. A semi-structured interview schedule was developed in line with the research aim. The interviews were audio-recorded, transcribed and thematic analysis was undertaken concurrently with data collection for ongoing refinement of questions and to address emerging issues. RESULTS: These nursing managers described a strong service and community ethos. They regarded travellers' healthcare needs no differently to those of local people and described their strong commitment to the provision of healthcare services for their local communities, applying an inclusive definition of community. Traveller presentations were described as predominantly exacerbations of chronic illness such as chest pain, medication-related attendances, and accidents and injuries. No hospital activity data for traveller presentations were available as no reports were routinely generated. Travellers were reported as not always having realistic expectations about what healthcare is available in remote areas and arriving with mixed levels of preparedness. Most travellers were said to be well-prepared for their travel and self-management of their health. However, the healthcare services that can be provided in rural and remote areas needed to be better understood by travellers from metropolitan areas and their urban healthcare providers. CONCLUSION: Participants did not perceive travellers as a burden on health services but recommendations were made regarding their expectations and preparedness. Australia's national transition to electronic health records including a patient-held record was identified as a future support for continuity of care for travellers and to facilitate treatment planning. With no current information to characterise traveller presentations, routinely collected hospital data could be extracted to characterise this patient population, their presentations and the resources required to meet their care needs

Four Years of Airborne Measurements of Wildfire Emissions in California, with a Focus on the Evolution of Emissions During the Soberanes Megafire

Biomass burning is an important source of trace gases and particles which can influence air quality on local, regional, and global scales. With wildfire events increasing due to changes in land use, increasing population, and climate change, characterizing wildfire emissions and their evolution is vital. In this work we report in situ airborne measurements of carbon dioxide (CO2), methane (CH4), water vapor (H2O), ozone (O3), and formaldehyde (HCHO) from nine wildfire events in California between 2013 and 2016, which were sampled as part of the Alpha Jet Atmospheric eXperiment (AJAX) based at NASA Ames Research Center. One of those fires, the Soberanes Megafire, began on 22 July 2016 and burned for three months. During that time, five flights were executed to sample emissions near and downwind of the Soberanes wildfire. In situ data are used to determine enhancement ratios (ERs), or excess mixing ratio relative to CO2, as well as assess O3 production from the fire. Changes in the emissions as a function of fire evolution are explored. Air quality impacts downwind of the fire are addressed using ground-based monitoring site data, satellite smoke products, and the Community Multiscale Air Quality (CMAQ) photochemical grid model

Maternal inflammation at 0.7 gestation in ewes leads to intrauterine growth restriction and impaired glucose metabolism in offspring at 30 d of age

Fetal programming associated with intrauterine growth restriction (IUGR) leads to lifelong deficits in growth and metabolic function (Hales and Barker, 2013). IUGR arises when fetuses respond to poor in utero conditions by developing adaptations that repartition nutrients to critical tissues and away from skeletal muscle (Yates et al., 2012, 2018). This fetal programming is beneficial in utero but leads to persistent reductions in muscle mass and glucose homeostasis in offspring (DeFronzo et al., 1981). Recent studies by our laboratory in sheep and rats demonstrate that maternal inflammation during gestation induces fetal inflammatory adaptations that impair growth and disrupt muscle glucose metabolism (Cadaret et al., 2017, 2018). IUGR fetal skeletal muscle exhibits indicators of enhanced inflammatory sensitivity, which could disrupt glucose uptake and oxidation (Yates et al., 2016; Cadaret et al., 2018). Enhanced inflammatory responsiveness would help explain growth and metabolic deficits observed in IUGR offspring. We hypothesize that fetal programming induced by maternal inflammation persists in offspring and contributes to impaired growth and glucose metabolism at 30 d. Therefore, the objective of this study was to determine whether sustained maternal inflammation induced by bacterial endotoxin at 0.7 gestation leads to fetal programming that contributes to deficits in growth and glucose metabolism in offspring