Glucose production, gluconeogenesis, and hepatic tricarboxylic acid cycle fluxes measured by nuclear magnetic resonance analysis of a single glucose derivative

A triple-tracer method was developed to provide absolute fluxes contributing to endogenous glucose production and hepatic tricarboxylic acid (TCA) cycle fluxes in 24-h-fasted rats by 2H and 13C nuclear magnetic resonance (NMR) analysis of a single glucose derivative. A primed, intravenous [3,4-13C2]glucose infusion was used to measure endogenous glucose production; intraperitoneal 2H2O (to enrich total body water) was used to quantify sources of glucose (TCA cycle, glycerol, and glycogen), and intraperitoneal [U-13C3] propionate was used to quantify hepatic anaplerosis, pyruvate cycling, and TCA cycle flux. Plasma glucose was converted to monoacetone glucose (MAG), and a single 2H and 13C NMR spectrum of MAG provided the following metabolic data (all in units of [mu]mol/kg/min; n=6): endogenous glucose production (40.4 ± 2.9), gluconeogenesis from glycerol (11.5 ± 3.5), gluconeogenesis from the TCA cycle (67.3 ± 5.6), glycogenolysis (1.0 ± 0.8), pyruvate cycling (154.4 ± 43.4), PEPCK flux (221.7 ± 47.6), and TCA cycle flux (49.1 ± 16.8). In a separate group of rats, glucose production was not different in the absence of 2H2O and [U-13C]propionate, demonstrating that these tracers do not alter the measurement of glucose turnover.http://www.sciencedirect.com/science/article/B6W9V-4BWYNW7-2/1/140b73c9df39bb7829a8519979c37a6

Rebound effects could offset more than half of avoided food loss and waste

Acknowledgements We thank Peter Newton, Sebastian Dueñas-Ocampo, Rayna Benzeev, Lee Frankel-Goldwater, Waverly Eichhorst, Ryan Langendorf, and Hilary Brumberg for their feedback on earlier drafts of this document; and Ryan Langendorf for helpful feedback and discussion on the economic analysis. M.H. and M.G.B. acknowledge funding from the US Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) (Award number: 2020-38420-30727), and the University of Colorado Boulder Cooperative Institute for Research in Environmental Sciences (CIRES) (start-up grant to M.G.B.). S.J.D. was supported by the US National Science Foundation and US Department of Agriculture (INFEWS grant EAR 1639318) and by the ClimateWorks Foundation (grant 22-2100). .Peer reviewedPostprin

Range contraction enables harvesting to extinction

Economic incentives to harvest a species usually diminish as its abundance declines, because harvest costs increase. This prevents harvesting to extinction. A known exception can occur if consumer demand causes a declining species' harvest price to rise faster than costs. This threat may affect rare and valuable species, such as large land mammals, sturgeons, and bluefin tunas. We analyze a similar but underappreciated threat, which arises when the geographic area (range) occupied by a species contracts as its abundance declines. Range contractions maintain the local densities of declining populations, which facilitates harvesting to extinction by preventing abundance declines from causing harvest costs to rise. Factors causing such range contractions include schooling, herding, or flocking behaviors--which, ironically, can be predator-avoidance adaptations; patchy environments; habitat loss; and climate change. We use a simple model to identify combinations of range contractions and price increases capable of causing extinction from profitable overharvesting, and we compare these to an empirical review. We find that some aquatic species that school or forage in patchy environments experience sufficiently severe range contractions as they decline to allow profitable harvesting to extinction even with little or no price increase; and some high-value declining aquatic species experience severe price increases. For terrestrial species, the data needed to evaluate our theory are scarce, but available evidence suggests that extinction-enabling range contractions may be common among declining mammals and birds. Thus, factors causing range contraction as abundance declines may pose unexpectedly large extinction risks to harvested species.Comment: 25 pages total, 8 pages main text, 17 pages supporting informatio

A computational approach to managing coupled human–environmental systems: the POSEIDON model of ocean fisheries

Sustainable management of complex human–environment systems, and the essential services they provide, remains a major challenge, felt from local to global scales. These systems are typically highly dynamic and hard to predict, particularly in the context of rapid environmental change, where novel sets of conditions drive coupled socio-economic-environmental responses. Faced with these challenges, our tools for policy development, while informed by the past experience, must not be unduly constrained; they must allow equally for both the fine-tuning of successful existing approaches and the generation of novel ones in unbiased ways. We study ocean fisheries as an example class of complex human–environmental systems, and present a new model (POSEIDON) and computational approach to policy design. The model includes an adaptive agent-based representation of a fishing fleet, coupled to a simplified ocean ecology model. The agents (fishing boats) do not have programmed responses based on empirical data, but respond adaptively, as a group, to their environment (including policy constraints). This conceptual model captures qualitatively a wide range of empirically observed fleet behaviour, in response to a broad set of policies. Within this framework, we define policy objectives (of arbitrary complexity) and use Bayesian optimization over multiple model runs to find policy parameters that best meet the goals. The trade-offs inherent in this approach are explored explicitly. Taking this further, optimization is used to generate novel hybrid policies. We illustrate this approach using simulated examples, in which policy prescriptions generated by our computational methods are counterintuitive and thus unlikely to be identified by conventional frameworks

An Observed Correlation Between Thermal and Non-Thermal Emission in Gamma-Ray Bursts

Recent observations by the $Fermi$ Gamma-ray Space Telescope have confirmed the existence of thermal and non-thermal components in the prompt photon spectra of some Gamma-ray bursts (GRBs). Through an analysis of six bright Fermi GRBs, we have discovered a correlation between the observed photospheric and non-thermal $\gamma$-ray emission components of several GRBs using a physical model that has previously been shown to be a good fit to the Fermi data. From the spectral parameters of these fits we find that the characteristic energies, $E_{\rm p}$ and $kT$, of these two components are correlated via the relation $E_{\rm p} \propto T^{\alpha}$ which varies from GRB to GRB. We present an interpretation in which the value of index $\alpha$ indicates whether the jet is dominated by kinetic or magnetic energy. To date, this jet composition parameter has been assumed in the modeling of GRB outflows rather than derived from the data

Burst and persistent emission properties during the recent active episode of the anomalous x-ray pulsar 1E 1841-045

Copyright American Astronomical SocietyThe Swift/Burst Alert Telescope detected the first burst from 1E 1841-045 in 2010 May with intermittent burst activity recorded through at least 2011 July. Here we present Swift and Fermi/Gamma-ray Burst Monitor observations of this burst activity and search for correlated changes to the persistent X-ray emission of the source. The T-90 durations of the bursts range between 18 and 140 ms, comparable to other magnetar burst durations, while the energy released in each burst ranges between (0.8-25) x 10(38) erg, which is on the low side of soft gamma repeater bursts. We find that the bursting activity did not have a significant effect on the persistent flux level of the source. We argue that the mechanism leading to this sporadic burst activity in 1E 1841-045 might not involve large-scale restructuring (either crustal or magnetospheric) as seen in other magnetar sources.Peer reviewedFinal Accepted Versio

Vacuum Stability, Perturbativity, and Scalar Singlet Dark Matter

We analyze the one-loop vacuum stability and perturbativity bounds on a singlet extension of the Standard Model (SM) scalar sector containing a scalar dark matter candidate. We show that the presence of the singlet-doublet quartic interaction relaxes the vacuum stability lower bound on the SM Higgs mass as a function of the cutoff and lowers the corresponding upper bound based on perturbativity considerations. We also find that vacuum stability requirements may place a lower bound on the singlet dark matter mass for given singlet quartic self coupling, leading to restrictions on the parameter space consistent with the observed relic density. We argue that discovery of a light singlet scalar dark matter particle could provide indirect information on the singlet quartic self-coupling.Comment: 25 pages, 10 figures; v2 - fixed minor typos; v3 - added to text discussions of other references, changed coloring of figures for easier black and white viewin

Stimulation of 3D osteogenesis by mesenchymal stem cells using a nanovibrational bioreactor

Bone grafts are one of the most commonly transplanted tissues. However, autologous grafts are in short supply, and can be associated with pain and donor-site morbidity. The creation of tissue-engineered bone grafts could help to fulfil clinical demand and provide a crucial resource for drug screening. Here, we show that vibrations of nanoscale amplitude provided by a newly developed bioreactor can differentiate a potential autologous cell source, mesenchymal stem cells (MSCs), into mineralized tissue in 3D. We demonstrate that nanoscale mechanotransduction can stimulate osteogenesis independently of other environmental factors, such as matrix rigidity. We show this by generating mineralized matrix from MSCs seeded in collagen gels with stiffness an order of magnitude below the stiffness of gels needed to induce bone formation in vitro. Our approach is scalable and can be compatible with 3D scaffolds

Gender Differences in Demographic and Clinical Correlates among Veterans with Musculoskeletal Disorders

Background Studies suggest that women may be at greater risk for developing chronic pain and pain-related disability. Methods Because musculoskeletal disorders (MSD) are the most frequently endorsed painful conditions among veterans, we sought to characterize gender differences in sociodemographic and clinical correlates among veterans upon entry into Veterans Health Administration's Musculoskeletal Disorders Cohort (n = 4,128,008). Results Women were more likely to be younger, Black, unmarried, and veterans of recent conflicts. In analyses adjusted for gender differences in sociodemographics, women were more likely to have diagnoses of fibromyalgia, temporomandibular disorders, and neck pain. Almost one in five women (19.4%) had more than one MSD diagnosis, compared with 15.7% of men; this higher risk of MSD multimorbidity remained in adjusted analyses. Adjusting for sociodemographics, women with MSD were more likely to have migraine headache and depressive, anxiety, and bipolar disorders. Women had lower odds of cardiovascular diseases, substance use disorders, and several MSDs, including back pain conditions. Men were more likely to report “no pain” on the pain intensity Numeric Rating Scale, whereas more women (41%) than men (34%) reported moderate to severe pain (Numeric Rating Scale 4+). Conclusions Because women veterans are more likely to have conditions such as fibromyalgia and mental health conditions, along with greater pain intensity in the setting of MSD, women-specific pain services may be needed