Sedentary States Research Articles

Chronic UCN2 Administration Alters Muscle Mass, Exercise Metabolism, and Exercise Capacity in Lean Mice

Urocortin 2 (UCN2) is a member of the corticotropin-releasing hormone (CRH) family and an agonist of the G protein-coupled receptor CRH receptor type 2 (CRHR2), which is highly expressed in skeletal muscle but absent from liver in both rodents and humans. UCN2 overexpression or chronic administration increases muscle mass in both lean and diet-induced obese (DIO) mice and is also believed to increase peripheral insulin sensitivity, reminiscent of the effect of acute exercise. However, how these effects of UCN2 may impact muscle function and exercise capacity remain incompletely understood. We hypothesized that treatment with a long term UCN2 treatment would increase lean and muscle mass and improve aerobic exercise capacity in lean, healthy mice. Lean 10-week-old male C57Bl/6J mice completed treadmill acclimatization and an incremental running test to exhaustion to determine maximal running distance and peak oxygen consumption (VO2). Mice were assigned to sedentary or maximal running groups and were treated with UCN2 for 18 days. After the final dose, body composition was assessed by qNMR. Vehicle- and UCN2-treated mice assigned to the maximal running group completed a second maximal test, and immediately upon completion of exercise, blood glucose was measured, and tissues were collected. Blood glucose and tissues were collected from sedentary vehicle- and UCN2-treated mice in the fed state. UCN2 treatment increased food intake, qNMR lean mass, and individual muscle weights. UCN2-treated mice had reduced maximal running distance, peak VO2, and blood glucose in response to exercise compared to vehicle mice. In addition, UCN2-treated mice had reduced hepatic glycogen in both the sedentary and post maximal exercise states. Gastrocnemius muscle from sedentary UCN2-treated mice had increased glycogen content and reduced phosphorylation of glycogen synthase. Following maximal exercise, UCN2-treated mice had higher gastrocnemius glycogen compared to vehicle mice. This indicated similar total glycogen utilization between treatment groups in response to maximal exercise, despite UCN2-treated mice performing less work. Follow-up studies in sedentary mice demonstrated UCN2 dosing increased phosphorylation of proteins involved in insulin-dependent and -independent glucose uptake in gastrocnemius muscle. These findings indicate that UCN2 affects whole-body and muscle substrate utilization and glucose regulation and signaling which results in increased muscle mass and altered exercise capacity. However, the unpredictability of the effects of UCN2 agonism on these parameters requires much further study. This research was funded by Eli Lilly and Company. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Energy Required to Synthesize Lean and Adipose Tissue in Rats.

Although the energy stored in lean tissue (LT) and adipose tissue (AT) is well known, the energy required to synthesize these tissues is less clear. While elucidating the energy required for AT synthesis may not be so important, the elucidation of the energy required for LT synthesis is important for individuals who aim to increase their skeletal muscle. Theoretically the energy at the point at which ΔLT/Δbody weight (BW) reaches 100% on a regression curve, which indicates the relationship between ΔLT/ΔBW and the energy used to accumulate body tissue, is considered to be the energy expended to synthesize LT. We therefore investigated the relationship using rats. Rats of different ages, and rats in exercised or sedentary states were used because their ΔLT/ΔBW was expected to be different. ΔLT/ΔBW was higher in the 4-wk-old group than in the 8-wk-old group and higher in the exercise group than in the sedentary group. We found a positive correlation between ΔLT/ΔBW and the energy expended to synthesize tissues that accumulated in the body. This energy was lower in the 8-wk-old group, which had a lower ΔLT/ΔBW in comparison to the 4-wk-old group, but was not affected by exercise. The regression curve revealed that the energy expended to synthesize LT was 2.9 kcal/g, while that expended to synthesize AT was 1.1 kcal/g. Therefore, combined with the energy accumulated to the tissues, the energy required to accumulate LT is approximately 4.0 kcal/g, while that required to accumulate AT is approximately 8.5 kcal/g.

Chemerin affects blood lipid profile of high-fat diet male mice in sedentary and exercise states via glucose and lipid metabolism enzymes.

Adipokine chemerin plays important roles in disorders of glucose and lipid metabolism of obesity and obesity-related diseases, and exercise-induced improvement of glucose and lipid metabolism is closely related to the decrease of chemerin, but the mechanisms by which chemerin regulates glucose and lipid metabolism remain unclarified. Hypotestosterone induces male obesity and disorders of glucose and lipid metabolism through androgen receptor (AR) and its target genes: glucose and lipid metabolism-related molecules (including FOXO1, PEPCK, PGC-1α, and SCD1). Recently, the link between them has been reported that chemerin modulated the secretion of androgen. In this study, global chemerin knockout (chemerin (-/-)) mice were established to demonstrate the roles of chemerin in regulating blood glucose and blood lipid of mice under diet (high-fat (HFD) and normal diet) and exercise interventions and then to explore its mechanisms (AR - glucose and lipid metabolism enzymes). We found that the blood lipid and adipocyte size were low accompanied by the improvements in the levels of serum testosterone, gastrocnemius AR, and gastrocnemius FOXO1, SCD1, and PGC-1α in HFD chemerin (-/-) mice, but exercise-induced improvements of these indicators in HFD WT mice were attenuated or abolished in HFD chemerin (-/-) mice. In conclusion, the decrease of chemerin improved the blood lipid profile of HFD male mice at sedentary and exercise states, mediated partly by the increases of testosterone and AR to regulate glucose and lipid metabolism enzymes. To our knowledge, it is the first report that chemerin's regulation of glucose and lipid metabolism might be mediated by testosterone and AR in vivo.

Animals in Mortuary Practices of Bronze-Age Pastoral Societies: Caprine Use at the Site of Dunping in Northwestern China.

The late second and first millennium BC witnessed extensive economic, cultural, and political exchanges between pastoralists and sedentary farming states in East Asia. Decades of archaeological fieldwork across northern China have revealed a large number of burial sites associated with pastoralists during the first millennium BC. These sites were characterized by the inhumation of specific animal parts in burials, predominantly the skulls and hooves of sheep, goats, cattle, and horses. However, the selection preference for these animals and how they were integrated into the mortuary contexts of these pastoral societies remain poorly investigated. Here, we report a preliminary analysis of caprine remains from 70 burials at the site of Dunping in the southern Gansu region of northwestern China, dated to approximately the seventh to fourth centuries BC. Based on an examination of species composition, post-depositional effects, traces of human alteration, skeletal element representation, and age at death, we discussed the selection, slaughtering, and inhumation of caprines concerning the mortuary practices at the site. Comparisons between Dunping and several other contemporaneous burial sites in neighboring regions, specifically in terms of the mortality profiles, further highlight distinct patterns in the selection of caprines for mortuary purposes among pastoral societies. These differences suggest varying degrees of emphasis placed on the economic and social significance attributed to caprines. Our findings provide new insights into the roles that caprines played in both ritual performances and subsistence practices among pastoralists in East Asia during the first millennium BC.

The relationship between physical activity states and depressive symptoms: Using ambulatory assessment to characterize day-to-day associations among individuals with and without bipolar spectrum disorder.

The role of activation in the pathogenesis of bipolar spectrum disorders (BSD) is of growing interest. Physical activity is known to improve mood, but it is unclear whether low activity levels contribute to inter-episode depressive symptoms observed in BSD. This study examined whether sedentary and vigorous activity, as well as the timing of the activity, were differentially associated with next-day depressive symptoms for individuals at low risk for BSD, high-risk for BSD, and diagnosed with BSD. Young adults (n = 111, ages 18-27) from three groups (low BSD risk, high BSD risk, and BSD diagnosis), participated in a 20-day ecological momentary assessment study. Physical activity was measured via wrist actigraphy counts. The percentage of time awake spent in sedentary, light, moderate, and vigorous activity states was calculated, as was the percentage of morning hours and evening hours in each activity state. Multilevel models examined whether theBSD risk group moderated associations between sedentary and vigorous activity and depressive symptoms, which were assessed three times daily. There were no between-group differences in time spent in each activity state, nor were there main effects of sedentary or vigorous activity on depression. Increased time spent engaging in vigorous activity was associated with a greater reduction in subsequent depressive symptoms for the BSD group. An increase in the evening, but not morning, vigorous activity was significantly associated with a reduction in subsequent depressive symptoms for the BSD group after controlling for chronotype. Interventions targeting physical activity may effectively help regulate inter-episode mood disturbances in BSD.

A one-dimensional three-state run-and-tumble model with a ‘cell cycle’

We study a one-dimensional three-state run-and-tumble model motivated by the bacterium Caulobacter crescentus which displays a cell cycle between two non-proliferating mobile phases and a proliferating sedentary phase. Our model implements kinetic transitions between the two mobile and one sedentary states described in terms of their number densities, where mobility is allowed with different running speeds in forward and backward direction. We start by analyzing the stationary states of the system and compute the mean and squared-displacements for the distribution of all cells, as well as for the number density of settled cells. The latter displays a surprising super-ballistic scaling sim t^3 at early times. Including repulsive and attractive interactions between the mobile cell populations and the settled cells, we explore the stability of the system and employ numerical methods to study structure formation in the fully nonlinear system. We find traveling waves of bacteria, whose occurrence is quantified in a non-equilibrium state diagram.Grapical abstract

183 Evaluation of Increase in Thromboembolism During the COVID-19 Pandemic

COVID-19 has been associated with a prothrombotic state suggesting an increased prevalence in thromboembolic events such as pulmonary embolus (PE) and deep venous thrombosis (DVT). Other risk factors of thromboembolic events include prolonged sedentary states which theoretically increased during mandatory stay at home orders during the height of the pandemic. There is little data to compare whether this also increased the rate of overall thromboembolic events in both COVID positive and negative patients during this time.

The Making and Breaking of Kinetic Empire: Mobility, Communication and Political Change in the Eastern Mediterranean, c. 900–1100 CE

AbstractThis paper applies the concept of ‘kinetic empire’ to the eastern Mediterranean world in the tenth and eleventh centuries. The term ‘kinetic empire’ is borrowed from Hämäläinen's analysis of the eighteenth- and nineteenth-century north American Comanche Empire. It refers to the way in which trans- and supra-regional power could be created, expressed and enforced through mobile means. The article focuses primarily on the role of mobility in the expansion of the Byzantine Empire between c. 900 and 1050, but also makes comparison with the contemporaneous Fatimid caliphate and other regional polities which we might usually regard as sedentary states. Recovering the role of the kinetic not only extends our understanding of the modalities of power in this crucial region of the medieval world, it also allows us to question the nature and degree of transformation wrought by mobile newcomers, such as Normans, crusaders and Turks in the later decades of the eleventh century. In this sense of developing and exploring concepts useful for the study of the transregional in premodernity and questioning standard periodisations, this article is also a practical exercise in medieval global history.

High-Resolution Digital Phenotypes From Consumer Wearables and Their Applications in Machine Learning of Cardiometabolic Risk Markers: Cohort Study.

BackgroundConsumer-grade wearable devices enable detailed recordings of heart rate and step counts in free-living conditions. Recent studies have shown that summary statistics from these wearable recordings have potential uses for longitudinal monitoring of health and disease states. However, the relationship between higher resolution physiological dynamics from wearables and known markers of health and disease remains largely uncharacterized.ObjectiveWe aimed to derive high-resolution digital phenotypes from observational wearable recordings and to examine their associations with modifiable and inherent markers of cardiometabolic disease risk.MethodsWe introduced a principled framework to extract interpretable high-resolution phenotypes from wearable data recorded in free-living conditions. The proposed framework standardizes the handling of data irregularities; encodes contextual information regarding the underlying physiological state at any given time; and generates a set of 66 minimally redundant features across active, sedentary, and sleep states. We applied our approach to a multimodal data set, from the SingHEART study (NCT02791152), which comprises heart rate and step count time series from wearables, clinical screening profiles, and whole genome sequences from 692 healthy volunteers. We used machine learning to model nonlinear relationships between the high-resolution phenotypes on the one hand and clinical or genomic risk markers for blood pressure, lipid, weight and sugar abnormalities on the other. For each risk type, we performed model comparisons based on Brier scores to assess the predictive value of high-resolution features over and beyond typical baselines. We also qualitatively characterized the wearable phenotypes for participants who had actualized clinical events.ResultsWe found that the high-resolution features have higher predictive value than typical baselines for clinical markers of cardiometabolic disease risk: the best models based on high-resolution features had 17.9% and 7.36% improvement in Brier score over baselines based on age and gender and resting heart rate, respectively (P<.001 in each case). Furthermore, heart rate dynamics from different activity states contain distinct information (maximum absolute correlation coefficient of 0.15). Heart rate dynamics in sedentary states are most predictive of lipid abnormalities and obesity, whereas patterns in active states are most predictive of blood pressure abnormalities (P<.001). Moreover, in comparison with standard measures, higher resolution patterns in wearable heart rate recordings are better able to represent subtle physiological dynamics related to genomic risk for cardiometabolic disease (improvement of 11.9%-22.0% in Brier scores; P<.001). Finally, illustrative case studies reveal connections between these high-resolution phenotypes and actualized clinical events, even for borderline profiles lacking apparent cardiometabolic risk markers.ConclusionsHigh-resolution digital phenotypes recorded by consumer wearables in free-living states have the potential to enhance the prediction of cardiometabolic disease risk and could enable more proactive and personalized health management.

PHILOSOPHY OF THE MODERN TEXT: THE FEATURES OF THE NARRATIVE STRUCTURE

The article deals with the problem of the philosophy of the text as a complex episteme of modern humanitarian discourse. The issue of the specifics of the narrative structure, the polyphony of the text in the dialogical space of modern literary discourse is actualized. It is proposed to consider the text in two aspects: the text as an autonomous object of reflection and the text as a code. Literary practices are investigated from the point of view of identifying mechanisms for the implementation of a given narrative structure and a voluminous descriptive plan of the text.The production of metatext is becoming one of the most significant trends in modern Kazakh prose, especially the novel genre. Special attention is paid to the analysis of the nuclear concepts of the narrative and their interaction with other elements of the poetics of the text. It is determined that the narrative frame of the text can be formed linearly and linearly. The philosophy of the text is inextricably linked with the general narratological postulate of eventfulness and a specific hierarchy of events, characters in the work. It is determined that the conceptual task of Kazakh historical romance is a panoramic examination of the complex historical and cultural ties of ancient nomadic and sedentary states. A combination of the traditional lyric-epic, realistic and postmodern aspects, the interaction of ethno-and foreign-cultural elements within one text is investigated. This approach determines the style of the text, deepening its philosophical and worldview content.Jamie E. Carroll's idea of ​​“transition from the text as a complete work to the text” with potentially maximum wide interpretive and communicative freedom seems to be productive when considering the philosophy of the text, its narrative specificity. In this case, the emergence of texts with a predominantly hybrid genre-style nature (novel-essay, novel-requiem, journalistic story, etc.) is possible.

Empires and Exchanges in Eurasian Late Antiquity. Rome, China, Iran, and the Steppe, ca. 250-750

This article reviews a collection of twenty-six studies on Eurasia in Late Antiquity, edited by Nicola Di Cosmo and Michael Maas (2018). Aside from presenting a brief summary of all the chapters included in the volume, I discuss several contributions at length and engage with the methodology outlined by the editors in the Introduction. While the book focuses on Late Antique steppe empires (Huns, Türks, Avars, etc.) and the multiple ways these interacted with the great sedentary states of Eurasia (Byzantium, Iran, China), many chapters offer exciting new perspectives on a score of other topics, such as Silk Road trade, religion, history of science, migration, diplomacy and political ideology. On the whole, Empires and Exchanges is an extremely valuable addition to the growing number of studies that attempt to provide a holistic approach to Eurasian history.

A passive perspiration biofuel cell: High energy return on investment

<h2>Summary</h2> Self-powered wearable systems that rely on bioenergy harvesters commonly require excessive energy inputs from the human body and are highly inefficient when accounting for the overall energy expenses. A harvester independent from the external environment for sedentary states has yet to be developed. Herein, we present a touch-based lactate biofuel cell that leverages the high passive perspiration rate of fingertips for bioenergy harvesting. Powered by finger contact, such a bioenergy-harvesting process can continuously collect hundreds of mJ of energy during sleep without movements, representing the most efficient approach compared to any reported on-body harvesters. To maximize the energy harvesting, complementary piezoelectric generators were integrated under the biofuel cell to further scavenge mechanical energy from the finger presses. The harvesters can rapidly and efficiently power sensors and electrochromic displays to enable independent self-powered sensing. The passive perspiration-based harvester establishes a practical example of remarkably high energy return on investment for future self-sustainable electronic systems.

Preclinical techniques to investigate exercise training in vascular pathophysiology.

Atherosclerosis is a dynamic process starting with endothelial dysfunction and inflammation and eventually leading to life-threatening arterial plaques. Exercise generally improves endothelial function in a dose-dependent manner by altering hemodynamics, specifically by increased arterial pressure, pulsatility, and shear stress. However, athletes who regularly participate in high-intensity training can develop arterial plaques, suggesting alternative mechanisms through which excessive exercise promotes vascular disease. Understanding the mechanisms that drive atherosclerosis in sedentary versus exercise states may lead to novel rehabilitative methods aimed at improving exercise compliance and physical activity. Preclinical tools, including in vitro cell assays, in vivo animal models, and in silico computational methods, broaden our capabilities to study the mechanisms through which exercise impacts atherogenesis, from molecular maladaptation to vascular remodeling. Here, we describe how preclinical research tools have and can be used to study exercise effects on atherosclerosis. We then propose how advanced bioengineering techniques can be used to address gaps in our current understanding of vascular pathophysiology, including integrating in vitro, in vivo, and in silico studies across multiple tissue systems and size scales. Improving our understanding of the antiatherogenic exercise effects will enable engaging, targeted, and individualized exercise recommendations to promote cardiovascular health rather than treating cardiovascular disease that results from a sedentary lifestyle.

A History of Russia, Central Asia and Mongolia. Volume II: Inner Eurasia from the Mongol Empire to Today, 1260–2000 by Christian David (review)

REVIEWS 575 to include. It has enabled him to write a definitive account of the origins of the extraordinary filmmaker Dziga Vertov, which also makes a major contribution to our understanding of Russian and Soviet cinema, history and culture more broadly. UCL SSEES Rachel Morley Christian, David. A History of Russia, Central Asia and Mongolia. Volume II: Inner Eurasia from the Mongol Empire to Today, 1260–2000. The Blackwell History of the World. Wiley Blackwell, Hoboken, NJ and Chichester, 2018. xxxv + 619 pp. Maps. Illustrations. Tables. Figures. Notes. Chronology. Index. $49.95: £34.99 (paperback). Since the first volume of David Christian’s wide-ranging history of Inner Eurasia (From Prehistory to the Mongol Empire) was published in 1998, Blackwell’s publishing house has succumbed to the embrace of the Wiley conglomerate, and the historiography of Inner Eurasia has been completely transformed by greater access to archives, fieldwork and archaeological sites, and new generations of post-Soviet scholars writing in English, Russian and Central Asian languages. It is greatly to Christian’s credit that he has, by and large, managed to stay abreast of these changes during the twenty years of the book’s gestation, though there are one or two areas where he relies too heavily on what are now thoroughly outdated Sovietological works. If the focus of the book is squarely on Russia, at least from the sixteenth century onwards when Muscovy became the major Inner Eurasian political power, it is enormously refreshing to see what are some quite familiar political and economic narratives reframed within a Eurasian rather than a European context. Viewed in this way, Muscovy, the Russian Empire and the USSR emerge not as a backward and benighted European fringe, but as the polity which was able most successfully to mobilize Inner Eurasia’s scanty agrarian resources to create a new centre of power in the post-Mongol period. The central metaphor used throughout Christian’s work is that of the smychka, or ‘yoking together’ of the resources produced by sedentary agrarian societies with the military potential of nomadic pastoralists. As he puts it: ‘to hold a smychka together, you needed a strong yoke and a skilful driver. If the first two components of the smychka were steppe armies and agrarian wealth, the third was elite discipline. Without the yoke and the whip, the two beasts headed off in different directions and plowing [sic] ceased’ (p. 16). Christian returns to these themes consistently throughout, and they have considerable explanatory power for the broad sweep of Eurasian history. Before 1500 those elites were often nomadic, reflecting the inbuilt military advantage SEER, 98, 3, JULY 2020 576 which their way of life gave them over sedentary societies in the pre-gunpowder age (pp. 12–13): the Golden Horde was one of the most successful and longlasting examples of the smychka, dominating and extracting resources from the principalities of Rus to maintain its military power on the steppe. From the early sixteenth century however, sedentary states gained a growing advantage as they succeeded in mobilizing greater agrarian resources (pp. 76–78): Muscovy gradually rose to dominance in Western Eurasia, as China did in the East. The defeat and destruction of the Junghar confederation by the Qing dynasty in the 1750s was first time a sedentary state had managed to project its power deeply and permanently into nomadic territory, securing China’s Inner Asian frontier. It would be another hundred years before Russia did the same in Western Central Asia, but the mobilizational power of the state also grew dramatically in this period, allowing it to use Eurasian resources to become a European great power. While elite coherence and mobilizational capacity broke down in Russia in 1917 and 1991, and in China between 1911 and 1949, it would subsequently be renewed — in China’s case to remarkable effect. Christian’sbookisespeciallystrongontheecologicalsetting—theparticular environmental constraints that produced pastoral nomadism and the peculiar forms of state-building and resource mobilization found across Inner Eurasia. Extremes of temperature, poor soil quality, short growing seasons and sparse populations made it imperative that the state control and mobilize as high a proportion as possible of the scanty resources available. It is this, rather than any...

Speciation Associated with Shifts in Migratory Behavior in an Avian Radiation.

Migratory animals move up to thousands of kilometers every year [1]. Losses of migration (i.e., migratory drop-offs) occur when individuals of a migratory species stop migrating and establish founder sedentary populations, a phenomenon documented in birds [2-5] and butterflies [6]. In theory, losses-and also gains-of migration might promote speciation if sedentary and migratory populations become reproductively isolated [7-9]. Because migratory and sedentary strategies involve alternative physiological, behavioral, and morphological traits [10-13], divergence along multiple axes of organismal function is expected to accompany switches in migratory behavior, potentially accelerating speciation. We present evidence of speciation driven by a migratory drop-off in the fork-tailed flycatcher (Tyrannus savana) resulting in reproductive isolation likely driven by changes in breeding schedules (allochronic speciation [13-15]) and geographic isolation of breeding grounds (allopatric speciation [16]). Phylogenetic analyses across New World flycatchers (Tyrannidae) showed that an association between speciation and drop-offs is also observable at a macroevolutionary scale. Loss of migration was significantly more frequent than its gain, and speciation rates of migratory and partially migratory lineages (i.e., species having both migratory and sedentary populations) exceeded those of sedentary lineages. Models of trait evolution indicated that partial migration is an intermediate step between migratory and sedentary states in this family. Given that partial migration is widespread across migratory animals (e.g., of all migratory birds, ca. 51% are partially migratory [5]), speciation via switches in migratory behavior might be an important yet overlooked mechanism of animal diversification.

Active-to-Sedentary Behavior Transitions, Fatigability, and Physical Functioning in Older Adults.

With aging, daily physical activity (PA) becomes less frequent and more fragmented. Accumulation patterns of daily PA-including transitions from active-to-sedentary behaviors-may provide important insights into functional status in older, less active populations. Participants of the Baltimore Longitudinal Study of Aging (n = 680, 50% male, aged 27-94 years) completed a clinical assessment and wore an Actiheart accelerometer. Transitions between active and sedentary states were modeled as a probability (Active-to-Sedentary Transition Probability [ASTP]) defined as the reciprocal of the average PA bout duration. Cross-sectional associations between ASTP and gait speed (m/s), fatigability (rating-of-perceived-exertion [RPE]), 400 m time (seconds), and expanded short physical performance battery score were modeled using linear and logistic regression, adjusted for chronic conditions. Further analyses explored the utility of ASTP over-and-above total daily PA. In continuous models, each 0.10-unit higher ASTP was associated slower gait (β = -0.06 m/s, SE = 0.01), higher fatigability (β = 0.60 RPE, SE = 0.12), slower 400 m time (β = 16.31 s, SE = 2.70), and lower functioning (β = -0.13 expanded short physical performance battery score, SE = 0.03; p < .001). In categorical analyses, those in the highest tertile of ASTP were >2 times more likely to have high fatigability (rating of perceived exertion ≥10), slow 400 m time (>300 seconds) and reduced functional performance (expanded short physical performance battery score < 3.07) than those in the lowest tertile (p < .01). Further analyses demonstrated ASTP provided additional insight into functional outcomes beyond total daily PA. Fragmented daily PA-as measured by ASTP-is strongly linked with measures of health and functional status and may identify those at risk of high fatigability and reduced functional performance over and above traditional PA metrics.

Activity Monitoring with a Wrist-Worn, Accelerometer-Based Device.

This study condenses huge amount of raw data measured from a MEMS accelerometer-based, wrist-worn device on different levels of physical activities (PAs) for subjects wearing the device 24 h a day continuously. In this study, we have employed the device to build up assessment models for quantifying activities, to develop an algorithm for sleep duration detection and to assess the regularity of activity of daily living (ADL) quantitatively. A new parameter, the activity index (AI), has been proposed to represent the quantity of activities and can be used to categorize different PAs into 5 levels, namely, rest/sleep, sedentary, light, moderate, and vigorous activity states. Another new parameter, the regularity index (RI), was calculated to represent the degree of regularity for ADL. The methods proposed in this study have been used to monitor a subject’s daily PA status and to access sleep quality, along with the quantitative assessment of the regularity of activity of daily living (ADL) with the 24-h continuously recorded data over several months to develop activity-based evaluation models for different medical-care applications. This work provides simple models for activity monitoring based on the accelerometer-based, wrist-worn device without trying to identify the details of types of activity and that are suitable for further applications combined with cloud computing services.

The ETS-5 transcription factor regulates activity states in Caenorhabditis elegans by controlling satiety

Animal behavior is shaped through interplay among genes, the environment, and previous experience. As in mammals, satiety signals induce quiescence in Caenorhabditis elegans Here we report that the C. elegans transcription factor ETS-5, an ortholog of mammalian FEV/Pet1, controls satiety-induced quiescence. Nutritional status has a major influence on C. elegans behavior. When foraging, food availability controls behavioral state switching between active (roaming) and sedentary (dwelling) states; however, when provided with high-quality food, C. elegans become sated and enter quiescence. We show that ETS-5 acts to promote roaming and inhibit quiescence by setting the internal "satiety quotient" through fat regulation. Acting from the ASG and BAG sensory neurons, we show that ETS-5 functions in a complex network with serotonergic and neuropeptide signaling pathways to control food-regulated behavioral state switching. Taken together, our results identify a neuronal mechanism for controlling intestinal fat stores and organismal behavioral states in C. elegans, and establish a paradigm for the elucidation of obesity-relevant mechanisms.

Acute Modulation of Cortical Glutamate and GABA Content by Physical Activity.

Converging evidence demonstrates that physical activity evokes a brain state characterized by distinctive changes in brain metabolism and cortical function. Human studies have shown that physical activity leads to a generalized increase in electroencephalography power across regions and frequencies, and a global increase in brain nonoxidative metabolism of carbohydrate substrates. This nonoxidative consumption of carbohydrate has been hypothesized to include increased de novo synthesis of amino acid neurotransmitters, especially glutamate and GABA. Here, we conducted a series of proton magnetic resonance spectroscopy studies in human volunteers before and after vigorous exercise (≥80% of predicted maximal heart rate). Results showed that the resonance signals of both glutamate and GABA increased significantly in the visual cortex following exercise. We further demonstrated a similar increase in glutamate following exercise in an executive region, the anterior cingulate cortex. The increase in glutamate was similar when using echo times of 30 and 144 ms, indicating that exercise-related T2 relaxation effects across this range of relaxation times did not account for the findings. In addition, we found preliminary evidence that more physical activity during the preceding week predicts higher resting glutamate levels. Overall, the results are consistent with an exercise-induced expansion of the cortical pools of glutamate and GABA, and add to a growing understanding of the distinctive brain state associated with physical activity. A more complete understanding of this brain state may reveal important insights into mechanisms underlying the beneficial effects of physical exercise in neuropsychiatric disorders, neurorehabilitation, aging, and cognition.

A hidden Markov model for reconstructing animal paths from solar geolocation loggers using templates for light intensity.

BackgroundSolar archival tags (henceforth called geolocators) are tracking devices deployed on animals to reconstruct their long-distance movements on the basis of locations inferred post hoc with reference to the geographical and seasonal variations in the timing and speeds of sunrise and sunset. The increased use of geolocators has created a need for analytical tools to produce accurate and objective estimates of migration routes that are explicit in their uncertainty about the position estimates.ResultsWe developed a hidden Markov chain model for the analysis of geolocator data. This model estimates tracks for animals with complex migratory behaviour by combining: (1) a shading-insensitive, template-fit physical model, (2) an uncorrelated random walk movement model that includes migratory and sedentary behavioural states, and (3) spatially explicit behavioural masks.The model is implemented in a specially developed open source R package FLightR. We used the particle filter (PF) algorithm to provide relatively fast model posterior computation. We illustrate our modelling approach with analysis of simulated data for stationary tags and of real tracks of both a tree swallow Tachycineta bicolor migrating along the east and a golden-crowned sparrow Zonotrichia atricapilla migrating along the west coast of North America.ConclusionsWe provide a model that increases accuracy in analyses of noisy data and movements of animals with complicated migration behaviour. It provides posterior distributions for the positions of animals, their behavioural states (e.g., migrating or sedentary), and distance and direction of movement.Our approach allows biologists to estimate locations of animals with complex migratory behaviour based on raw light data. This model advances the current methods for estimating migration tracks from solar geolocation, and will benefit a fast-growing number of tracking studies with this technology.