3,429 research outputs found
DEMAND FOR DIFFERENTIATED VEGETABLES
To obtain a healthier diet, Americans need to consume not only more vegetables, but also a healthier mix of vegetables. Household demands for eight categories of vegetables are investigated, using ACNielsen's Homescan data. A maximum simulated likelihood estimation procedure results in elasticity estimates which are somewhat larger than those obtained from both time-series and cross-section data in the literature. Even these larger elasticities are not large enough to bridge the dietary consumption gap without, and possibly even with, substantial price or food expenditure subsidies. Furthermore, Homescan data do indicate some significant differences in preferences for types of vegetables by household characteristics, such as race and ethnicity. This information could be used in designing more effective public interventions for boosting vegetable consumption in the United States.Food Consumption/Nutrition/Food Safety,
Topological Sector Fluctuations and Curie Law Crossover in Spin Ice
At low temperatures, a spin ice enters a Coulomb phase - a state with
algebraic correlations and topologically constrained spin configurations. In
Ho2Ti2O7, we have observed experimentally that this process is accompanied by a
non-standard temperature evolution of the wave vector dependent magnetic
susceptibility, as measured by neutron scattering. Analytical and numerical
approaches reveal signatures of a crossover between two Curie laws, one
characterizing the high temperature paramagnetic regime, and the other the low
temperature topologically constrained regime, which we call the spin liquid
Curie law. The theory is shown to be in excellent agreement with neutron
scattering experiments. On a more general footing, i) the existence of two
Curie laws appears to be a general property of the emergent gauge field for a
classical spin liquid, and ii) sheds light on the experimental difficulty of
measuring a precise Curie-Weiss temperature in frustrated materials; iii) the
mapping between gauge and spin degrees of freedom means that the susceptibility
at finite wave vector can be used as a local probe of fluctuations among
topological sectors.Comment: 10 pages, 5 figure
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Australia’s first trap-and-haul fishway: Nerang River, Queensland
Australia’s first trap-and-haul fishway was built on the Nerang River in southeast Queensland during enlargement of the Hinze Dam. In gaining government approval for the project, the constructing alliance (HDA) concluded that providing upstream fish passage would have significant environmental benefits by conserving upstream native fish communities and encouraging recruitment into the reservoir’s recreational fishery. But downstream passage, other than modifications to protect fish emigrating during spill events, could not be justified. Severely constrained outflows from the dam and the impacts of downstream urban development contrast starkly with upstream habitat conditions.
North American design approaches were adapted to suit the river’s fishes and streamflows. Challenges for fish passage at the site included the marked restriction of downstream river flows and the location of the flow-release point 300m from the spillway. A barrier weir was built to prevent upstream migrants bypassing the fishway entrance during spillway flows. HDA developed a trap-and-haul system to collect migrating fish at the weir and transport them by tanker to multiple upstream release areas. This system provides flexibility to accommodate varying fish biomass; ability to operate over a range of flows up to 20-year ARI events; facilities for sorting, data collection and removal of pest species; and capacity to limit predation mortalities. Fishway performance studies led to redesign of the entrance vee-trap and other modifications. To 2017, 55,590 fish from 27 large and small-bodied species used the fishway, together with 8 turtles. Fish of three pest species were identified in the sorting facility and removed to prevent their entry to the reservoir.
This paper covers the project life cycle for Australia’s first trap-and-haul fishway including the basis for selecting the fishway type, design and construction. Fishway performance studies and results from ongoing operation, including the lessons learned and the improvements made, are also discussed
Combined Blood Flow Restriction Training and Betaine Supplementation Impacts on Serum Betaine and Homocysteine Concentrations
Homocysteine (HCY) is a clinically implicated in inflammation and cardiovascular impairments. Although both betaine supplementation and acute resistance (both high-load [HL] and low-load blood flow restriction [LL-BFR]) training notably attenuate HCY concentrations, it is hitherto unknown if these independent modalities synergistically interact. PURPOSE: to determine whether a combination of betaine supplementation, as well as acute HL and/or LL-BFR training can attenuate post-exercise HCY more effectively than either isolated modality. METHODS: Eighteen recreationally trained males (25±5y) were randomized in double-blind fashion to supplement 6g/day of either betaine anhydrous (BET) or identically dosed cellulose placebo for 14-days. Subsequently, all subjects performed four standardized sets of one-leg press and two additional sets to muscular failure on both legs in a counter-balanced and crossover design. Specifically, one leg performed standard high-load (HL; 70%1RM) exercise and contralateral limb underwent BFR (LL-BFR; 20%1RM) training at 80% arterial occlusion pressure. Serum homocysteine (HCY) and betaine (BET) concentrations were analyzed before and 30-minutes post-exercise prior to quantification via ELISA and liquid chromatography-mass spectrometry, respectively. The changes in all aforementioned variables from baseline (∆HCY and ∆BET) were assessed via separate two-way mixed model ANOVA with repeated measures at a significance level of pRESULTS: Analyses failed to reveal any significant main nor interaction effects for serum ∆BET. Although no apparent main supplement nor interaction effects were observed, ∆HCY demonstrated a significant main exercise condition effect (p=.045; ηp2=.228), whereby the LL-BFR group displayed significantly greater concentrations versus HL (p=.045). CONCLUSION: While these findings ultimately do not support a betaine-resistance training synergy-mediated reduction in serum HCY, our data otherwise suggest BFR training may preferentially result in lower post-training concentrations relative to a commonly employed, high-load approach. Future research should elucidate the credence of this interpretation via additional longitudinal investigations amidst hyperhomocysteinemia-predisposed clinical populations
Impacts of Varying Blood Flow Restriction Cuff Size and Material on Arterial, Venous and Calf Muscle Pump-Mediated Blood Flow
Blood flow restriction (BFR) may become ineffective or potentially dangerous without sufficient standardization. The purpose of this investigation was therefore to (1) assess the viability of multiple sizes of a novel BFR cuff to determine arterial occlusion pressure (AOP) and (2) compare resting arterial, venous and calf muscle pump (cMP)-mediated blood flow between the aforementioned conditions and a commonly employed wide-rigid, tourniquet-style cuff. In randomized, counter-balanced, and crossover fashion, 20 apparently healthy males (18–40 years) donned a widely employed wide-rigid (WR) cuff, along with the largest (NE) and manufacturer-recommended sizes (NER) of a novel narrow-elastic cuff. Participants subsequently assessed AOP, as well as (at 80%AOP) arterial, venous, and venous cMP flow relative to baseline values via ultrasound. All analyses were performed at a significance level of p \u3c 0.05. Analyses revealed a significant condition effect for AOP (p \u3c 0.001; ηp2 = 0.907) whereby WR was significantly lower than both NE and NER; in addition, the latter two did not differ. Compared with baseline, there were no statistically significant differences between cuffs for either arterial or cMP-mediated blood flow. Unsurprisingly, no participants demonstrated venous blood flow at 80% AOP. These findings support the viability of a novel narrow-elastic BFR product, evidenced by consistent AOP acquisition and equivocal blood flow parameters
The role of osteoanabolic agents in the management of patients with osteoporosis
Reducing fracture risk is the objective of osteoporosis treatment. Bone-forming osteoporosis drugs increase bone mass, restore bone microarchitecture, and reduce fracture risk more effectively than oral bisphosphonates, providing strong justification for the use of these agents as the initial therapy or after anti-remodeling agents in patients at very high risk of fracture. At the end of a 12-to-24-month course of osteoanabolic therapy, transitioning to a potent anti-remodeling agent maintains and enhances the treatment benefit. This review describes the clinical applications of osteoanabolic therapy for osteoporosis
LGD-4033 and MK-677 Use Impacts Body Composition, Circulating Biomarkers, and Skeletal Muscle Androgenic Hormone and Receptor Content: A Case Report
LGD-4033, a selective androgen receptor modulator, and MK-677, a growth hormone secretagogue, are being used increasingly amongst recreationally active demographics. However, limited data exist describing their effects on health- and androgen-related biomarkers. The purpose of this case study was to determine changes in body composition and biomarkers during and after continued co-administration of LGD-4033 and MK-677. We also aimed to examine muscular strength and intramuscular androgen-associated biomarkers relative to non-users. A 25-year-old male ingested LGD-4033 (10 mg) and MK-677 (15 mg) daily for 5 weeks. Blood and body composition metrics were obtained pre-, on- and post-cycle. One-repetition maximum leg and bench press, in addition to intramuscular androgens and androgen receptor content, were analysed on-cycle. We observed pre- to on-cycle changes in body composition (body mass, +6.0%; total lean body mass, +3.1%; trunk lean body mass, +6.6%; appendicular lean body mass, +4.3%; total fat mass, +15.4%; trunk fat mass, +2.8%; and appendicular fat mass, +14.8%), bone (bone mineral content, −3.60%; area, −1.1%; and bone mineral density, −2.1%), serum lipid-associated biomarkers (cholesterol, +14.8%; triglycerides, +39.2%; low-density lipoprotein–cholesterol, +40.0%; and high-density lipoprotein–cholesterol, −36.4%), liver-associated biomarkers (aspartate aminotransferase, +95.8%; and alanine aminotransferase, +205.0%) and androgen-associated biomarkers (free testosterone, −85.7%; total testosterone, −62.3%; and sex hormone-binding globulin, −79.6%); however, all variables returned to pre-cycle values post-cycle, apart from total fat mass, appendicular fat mass, bone area, total cholesterol and low-density lipoprotein–cholesterol. Follicle-stimulating hormone was below clinical reference values on- (1.2 IU/L) and post-cycle (1.3 IU/L). Intramuscular androgen receptor (−44.6%), testosterone (+47.8%) and dihydrotestosterone (+34.4%), in addition to one-repetition maximum leg press and bench press (+39.2 and +32.0%, respectively), were different in the case subject compared with non-users. These data demonstrate that LGD-4033 and MK-677 increase several body composition parameters, whilst negatively impacting bone and several serum biomarkers. Given the sparsity of data in recreationally using demographics, further research is warranted to elucidate the acute and chronic physiological effects of these anabolic agents
Differential contribution of cis -regulatory elements to higher order chromatin structure and expression of the CFTR locus
Higher order chromatin structure establishes domains that organize the genome and coordinate gene expression. However, the molecular mechanisms controlling transcription of individual loci within a topological domain (TAD) are not fully understood. The cystic fibrosis transmembrane conductance regulator (CFTR) gene provides a paradigm for investigating these mechanisms. CFTR occupies a TAD bordered by CTCF/cohesin binding sites within which are cell-type-selective cis-regulatory elements for the locus. We showed previously that intronic and extragenic enhancers, when occupied by specific transcription factors, are recruited to the CFTR promoter by a looping mechanism to drive gene expression. Here we use a combination of CRISPR/Cas9 editing of cis-regulatory elements and siRNA-mediated depletion of architectural proteins to determine the relative contribution of structural elements and enhancers to the higher order structure and expression of the CFTR locus. We found the boundaries of the CFTR TAD are conserved among diverse cell types and are dependent on CTCF and cohesin complex. Removal of an upstream CTCF-binding insulator alters the interaction profile, but has little effect on CFTR expression. Within the TAD, intronic enhancers recruit cell-type selective transcription factors and deletion of a pivotal enhancer element dramatically decreases CFTR expression, but has minor effect on its 3D structure
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