509 research outputs found
ACTIVITY PATTERNS, FORAGING ECOLOGY, AND SUMMER RANGE CARRYING CAPACITY OF MOOSE (ALCES ALCES SHIRASI) IN ROCKY MOUNTAIN NATIONAL PARK, COLORADO
To ensure sustainable populations of native animals and plants, managers of protected areas must understand carrying capacity of large wild herbivores. Estimates of carrying capacity and how large herbivores may influence native vegetation require knowledge of their activity and forag­ing patterns. Therefore, we examined activity patterns and foraging behavior of adult male moose (Alces alces shirasi) in Rocky Mountain National Park, Colorado by following individual animals and counting bites during the summer and fall of 2003 and 2004. Mean active time per day peaked in late June at 11.3 h and declined to 8.9 h in early fall preceding the breeding season. Moose averaged 6.7 feeding periods/d, each lasting 79 min; feeding bouts were longer around sunrise and sunset and were shorter midday presumably because of high ambient temperature. Activities associated with feeding and resting constituted 94.0% of daily time budgets. Feeding declined and social behavior and move­ment increased in fall with the onset of the breeding season. Food consumption increased steadily through early summer peaking at 126.8 g/kg BW0.75 in early August, followed by a sharp decline to a low of 69.1 g/kg BW0.75 in early September. Daily digestible energy intake was estimated at 1191 kJ/kg BW0.75/d. Maximum rates of instantaneous intake were recorded in early August at 22.3 g/min. Because intake rates of willow (Salix spp.) increased from June-August, but nutritional quality peaked in mid-June, increases in daily and instantaneous intake rates during summer seemed more related to forage availability than protein and energy content of willow leaves. The nutritional carrying capacity of summer range in Rocky Mountain National Park in 2004 was estimated from the range supply of metabolizable energy, digestible energy, and available nitrogen. Based on the digestible energy intake and energy requirements of a 344 kg male moose, the summer range carrying capacity was estimated at 0.21 moose/km2. Nitrogen based estimates were considerably higher at 0.32 moose/km2
Politics, Governance, and Leadership: What Can We Learn From the Academy of Management’s Response to EO13769?
Organization design seeks to balance potentially conflicting objectives while achieving a broader mission. EO13769 created a challenge for the president of the Academy of Management in leading through these conflicts, as President Anita McGahan describes: how to be true to her own moral values while leading an organization with well-established design constraints, and members with diverse opinions. This article shares the perspectives of 12 scholars on the lessons we can learn from Professor McGahan’s leadership of a constraining organization through a challenging time
1973 Research Progress Reports, Fruit and Vegetable Processing and Food Technology
Evaluation of snap bean varieties for processing / Wilbur A. Gould -- Evaluation of tomato cultivars for processing / W. A. Gould, James Black, Emily Korensky, Ruth Stillabower, and Stanley Z. Berry -- Commercial tomato cultivar evaluation / Wilbur A. Gould, Jerry Wright, in cooperation with Stanley Berry, Marion White, Tip Top Canning Co., Beckman and Gast Company and Hirzel Canning Co. -- Relationship of USDA D6 tomato colorimeter to AGTRON E-5 / Wilbur A. Gould and Jerry Wright -- Effects of food additives on the quality of canned tomatoes / Wilbur A. Gould, Jacquelyn Gould, and James Black -- Effects of food additives on the quality of canned tomato juice / Wilbur A. Gould, Ruth Stillabower, Jacquelyn Gould and James Black -- Retention of ascorbic acid in fortified tomato juice ; Effect of storage time and temperature and added ascorbic acid on the total acid and pH of tomato juice / Gerald G. Pope and Wilbur A. Gould -- Cell wall components and tomato juice consistency / David E. Crean -- Lipid content of cabbage & sauerkraut / Andrew C. Peng -- Canned rice-tomatoes / Teung Chin and Wilbur A. Gould -- Development of a canned pecan pie filling / W. A. Gould and S. Perryman -- A new soybean food from tempeh / Nasruddin Iljas, Wilbur A. Gould and Andrew C. Peng -- Rehabilitation and recycling spend cucumber pickling brines / J. R. Geisman and R. E. Henne -- Evaluation of several grape cultivars for wine making / James F. Gallande
Citrobacter rodentium Subverts ATP Flux and Cholesterol Homeostasis in Intestinal Epithelial Cells In Vivo.
The intestinal epithelial cells (IECs) that line the gut form a robust line of defense against ingested pathogens. We investigated the impact of infection with the enteric pathogen Citrobacter rodentium on mouse IEC metabolism using global proteomic and targeted metabolomics and lipidomics. The major signatures of the infection were upregulation of the sugar transporter Sglt4, aerobic glycolysis, and production of phosphocreatine, which mobilizes cytosolic energy. In contrast, biogenesis of mitochondrial cardiolipins, essential for ATP production, was inhibited, which coincided with increased levels of mucosal O2 and a reduction in colon-associated anaerobic commensals. In addition, IECs responded to infection by activating Srebp2 and the cholesterol biosynthetic pathway. Unexpectedly, infected IECs also upregulated the cholesterol efflux proteins AbcA1, AbcG8, and ApoA1, resulting in higher levels of fecal cholesterol and a bloom of Proteobacteria. These results suggest that C. rodentium manipulates host metabolism to evade innate immune responses and establish a favorable gut ecosystem
Differential Iron Requirements for Osteoblast and Adipocyte Differentiation
Bone marrow mesenchymal progenitor cells are precursors for various cell types including osteoblasts, adipocytes, and chondrocytes. The external environment and signals act to direct the pathway of differentiation. Importantly, situations such as aging and chronic kidney disease display alterations in the balance of osteoblast and adipocyte differentiation, adversely affecting bone integrity. Iron deficiency, which can often occur during aging and chronic kidney disease, is associated with reduced bone density. The purpose of this study was to assess the effects of iron deficiency on the capacity of progenitor cell differentiation pathways. Mouse and human progenitor cells, differentiated under standard osteoblast and adipocyte protocols in the presence of the iron chelator deferoxamine (DFO), were used. Under osteogenic conditions, 5μM DFO significantly impaired expression of critical osteoblast genes, including osteocalcin, type 1 collagen, and dentin matrix protein 1. This led to a reduction in alkaline phosphatase activity and impaired mineralization. Despite prolonged exposure to chronic iron deficiency, cells retained viability as well as normal hypoxic responses with significant increases in transferrin receptor and protein accumulation of hypoxia inducible factor 1α. Similar concentrations of DFO were used when cells were maintained in adipogenic conditions. In contrast to osteoblast differentiation, DFO modestly suppressed adipocyte gene expression of peroxisome-proliferating activated receptor gamma, lipoprotein lipase, and adiponectin at earlier time points with normalization at later stages. Lipid accumulation was also similar in all conditions. These data suggest the critical importance of iron in osteoblast differentiation, and as long as the external stimuli are present, iron deficiency does not impede adipogenesis
Stellar Astrophysics and Exoplanet Science with the Maunakea Spectroscopic Explorer (MSE)
The Maunakea Spectroscopic Explorer (MSE) is a planned 11.25-m aperture
facility with a 1.5 square degree field of view that will be fully dedicated to
multi-object spectroscopy. A rebirth of the 3.6m Canada-France-Hawaii Telescope
on Maunakea, MSE will use 4332 fibers operating at three different resolving
powers (R ~ 2500, 6000, 40000) across a wavelength range of 0.36-1.8mum, with
dynamical fiber positioning that allows fibers to match the exposure times of
individual objects. MSE will enable spectroscopic surveys with unprecedented
scale and sensitivity by collecting millions of spectra per year down to
limiting magnitudes of g ~ 20-24 mag, with a nominal velocity precision of ~100
m/s in high-resolution mode. This white paper describes science cases for
stellar astrophysics and exoplanet science using MSE, including the discovery
and atmospheric characterization of exoplanets and substellar objects, stellar
physics with star clusters, asteroseismology of solar-like oscillators and
opacity-driven pulsators, studies of stellar rotation, activity, and
multiplicity, as well as the chemical characterization of AGB and extremely
metal-poor stars.Comment: 31 pages, 11 figures; To appear as a chapter for the Detailed Science
Case of the Maunakea Spectroscopic Explore
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Dopant activation in Sn-doped Ga2O3 investigated by X-ray absorption spectroscopy
Doping activity in both beta-phase (β-) and amorphous (a-) Sn-doped gallium oxide (Ga2O3:Sn) is investigated by X-ray absorption spectroscopy(XAS). A single crystal of β-Ga2O3:Sn grown using edge-defined film-fed growth at 1725 °C is compared with amorphous Ga2O3:Sn filmsdeposited at low temperature (<300 °C). Our XAS analyses indicate that activated Sn dopant atoms in conductive single crystal β-Ga2O3:Sn are present as Sn4+, preferentially substituting for Ga at the octahedral site, as predicted by theoretical calculations. In contrast, inactive Sn atoms in resistive a-Ga2O3:Sn are present in either +2 or +4 charge states depending on growth conditions. These observations suggest the importance of growing Ga2O3:Sn at high temperature to obtain a crystalline phase and controlling the oxidation state of Sn during growth to achieve dopant activation.Chemistry and Chemical Biolog
Age-dependent white matter disruptions after military traumatic brain injury: Multivariate analysis results from ENIGMA brain injury
Mild Traumatic brain injury (mTBI) is a signature wound in military personnel, and repetitive mTBI has been linked to age-related neurogenerative disorders that affect white matter (WM) in the brain. However, findings of injury to specific WM tracts have been variable and inconsistent. This may be due to the heterogeneity of mechanisms, etiology, and comorbid disorders related to mTBI. Non-negative matrix factorization (NMF) is a data-driven approach that detects covarying patterns (components) within high-dimensional data. We applied NMF to diffusion imaging data from military Veterans with and without a self-reported TBI history. NMF identified 12 independent components derived from fractional anisotropy (FA) in a large dataset (n = 1,475) gathered through the ENIGMA (Enhancing Neuroimaging Genetics through Meta-Analysis) Military Brain Injury working group. Regressions were used to examine TBI- and mTBI-related associations in NMF-derived components while adjusting for age, sex, post-traumatic stress disorder, depression, and data acquisition site/scanner. We found significantly stronger age-dependent effects of lower FA in Veterans with TBI than Veterans without in four components (q \u3c 0.05), which are spatially unconstrained by traditionally defined WM tracts. One component, occupying the most peripheral location, exhibited significantly stronger age-dependent differences in Veterans with mTBI. We found NMF to be powerful and effective in detecting covarying patterns of FA associated with mTBI by applying standard parametric regression modeling. Our results highlight patterns of WM alteration that are differentially affected by TBI and mTBI in younger compared to older military Veterans
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