230 research outputs found

    Evaluating Trade Developments in Dairy Products

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    Replaced with revised version of paper 02/11/04.International Relations/Trade,

    Will Changing Demographics Affect U.S. Cheese Demand?

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    U.S. cheese consumption has grown considerably over the last three decades. Using a censored demand model and Nielsen Homescan retail data, this study identifies price and non-price factors affecting the demand for differentiated cheese products. Own-price and expenditure elasticities for all of the cheese products are statistically significant and elastic. Results also reveal that a strong substitution relationship exists among all cheese products. Although demographic influences are generally smaller than those related to prices and expenditures, empirical findings show that household size, college educated female heads of household who are age 40 and older, residing in the South, Central, and Western regions of the United States, as well as Black heads of household, have positive statistically significant effects on consumers’ cheese purchases.cheese form, cheese purchase, demand elasticities, demographic and economic factors, Nielsen Homescan data, Food Consumption/Nutrition/Food Safety, Marketing, C25, D12, Q11,

    Mechanism of Fluoride Uptake by Hydroxyapatite from Acidic Fluoride Solutions: I. Theoretical Considerations

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    A mathematical model for the mechanism of calcium fluoride formation on hydroxyapatite in buffered fluoride solutions is proposed. It takes into account the physical and chemical processes that occur during the reaction. With the model it is possible to evaluate a priori the fluoride uptake potential of fluoride solutions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67263/2/10.1177_00220345700490066601.pd

    Indentation of the Pamirs with respect to the northern margin of Tibet: constraints from the Tarim basin sedimentary record

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    The Pamirs represent the indented westward continuation of the northern margin of the Tibetan Plateau, dividing the Tarim and Tajik basins. Their evolution may be a key factor influencing aridification of the Asian interior, yet the tectonics of the Pamir Salient are poorly understood. We present a provenance study of the Aertashi section, a Paleogene to late Neogene clastic succession deposited in the Tarim basin to the north of the NW margin of Tibet (the West Kunlun) and to the east of the Pamirs. Our detrital zircon U-Pb ages coupled with zircon fission track, bulk rock Sm-Nd, and petrography data document changes in contributing source terranes during the Oligocene to Miocene, which can be correlated to regional tectonics. We propose a model for the evolution of the Pamir and West Kunlun (WKL), in which the WKL formed topography since at least ~200 Ma. By ~25 Ma, movement along the Pamir-bounding faults such as the Kashgar-Yecheng Transfer System had commenced, marking the onset of Pamir indentation into the Tarim-Tajik basin. This is coincident with basinward expansion of the northern WKL margin, which changed the palaeodrainage pattern within the Kunlun, progressively cutting off the more southerly WKL sources from the Tarim basin. An abrupt change in the provenance and facies of sediments at Aertashi has a maximum age of 14 Ma; this change records when the Pamir indenter had propagated sufficiently far north that the North Pamir was now located proximal to the Aertashi region

    Parental genome unification is highly error-prone in mammalian embryos

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    Most human embryos are aneuploid. Aneuploidy frequently arises during the early mitotic divisions of the embryo, but its origin remains elusive. Human zygotes that cluster their nucleoli at the pronuclear interface are thought to be more likely to develop into healthy euploid embryos. Here, we show that the parental genomes cluster with nucleoli in each pronucleus within human and bovine zygotes, and clustering is required for the reliable unification of the parental genomes after fertilization. During migration of intact pronuclei, the parental genomes polarize toward each other in a process driven by centrosomes, dynein, microtubules, and nuclear pore complexes. The maternal and paternal chromosomes eventually cluster at the pronuclear interface, in direct proximity to each other, yet separated. Parental genome clustering ensures the rapid unification of the parental genomes on nuclear envelope breakdown. However, clustering often fails, leading to chromosome segregation errors and micronuclei, incompatible with healthy embryo development

    Long Sun-Exposures Influencing High Sub-Cutaneous Synthesis of Vitamin-D3 may be Associated with Exacerbation of Symptoms in Allergic-Asthma.

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    Does excessive sun-exposure, non-use of sunscreen and/or high doses of vitamin-D3 supplements provoke exacerbation of asthma? Clinical examinations, retrospective records-access and questionnaire surveys were distributed to a convenience sample of allergic-asthma patient (n=183). Patients (19-89 years) attending the outpatient respiratory clinics at Maidstone Hospital were enrolled. 90.3% of patients (total IgE levels ≥75 kU/L ; n=103) exposed to direct sunlight of ≥ 15 minutes per day continuously for 6-7 days presented with wheeze (χ2(1) = 7.46; p< 0.05) compared to only 9.7% patients of similar atopy-status, presenting with wheeze if exposed to sunlight of < 15 minutes per day for 6-7 days. 68.9% patients (with IgE levels ≥ 75 kU/L ; n=103), non-users of sunscreen (SPF 30 and above), exposed to direct sunlight of ≥ 15 minutes per day continuously for 6-7 days developed a wheeze, compared to fewer users of sunscreen (9.7%, n=103), exposed to the same duration of sunlight who developed asthma symptoms (p< 0.05). Vitamin-D3 supplementation in asthma-patients with clinical signs of hypovitaminosis-D (n=21), produced symptoms of morning chest-tightness (76.2%), allergic rhinitis (61.9%) and wheeze (100%), 2 weeks after initiation of treatment. Our results advocate direct sunlight exposure < 15 minutes per day and use of sunscreen as a novel approach to preventing atopic-asthma symptoms in allergic-asthma patients.. Activated vitamin-D3 is well-recognised to shift the immune-balance towards Th2 predominance, favouring allergic asthma. These results suggest that limiting subcutaneous synthesis of vitamin-D3 in asthma patients and re-addressing dosage of vitamin-D3 supplementation is necessary may contribute to prevent exacerbation of symptoms

    Development of lung function in very low birth weight infants with or without bronchopulmonary dysplasia: Longitudinal assessment during the first 15 months of corrected age

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    <p>Abstract</p> <p>Background</p> <p>Very low birth weight (VLBW) infants (< 1,500 g) with bronchopulmonary dysplasia (BPD) develop lung damage caused by mechanical ventilation and maturational arrest. We compared functional lung development after discharge from hospital between VLBW infants with and without BPD.</p> <p>Methods</p> <p>Comprehensive lung function assessment was performed at about 50, 70, and 100 weeks of postmenstrual age in 55 sedated VLBW infants (29 with former BPD [O<sub>2 </sub>supplementation was given at 36 weeks of gestational age] and 26 VLBW infants without BPD [controls]). Mean gestational age (26 vs. 29 weeks), birth weight (815 g vs. 1,125 g), and the proportion of infants requiring mechanical ventilation for ≥7 d (55% vs. 8%), differed significantly between BPD infants and controls.</p> <p>Results</p> <p>Both body weight and length, determined over time, were persistently lower in former BPD infants compared to controls, but no significant between-group differences were noted in respiratory rate, respiratory or airway resistance, functional residual capacity as determined by body plethysmography (FRC<sub>pleth</sub>), maximal expiratory flow at the FRC (V'max <sub>FRC</sub>), or blood gas (pO<sub>2</sub>, pCO<sub>2</sub>) levels. Tidal volume, minute ventilation, respiratory compliance, and FRC determined by SF6 multiple breath washout (representing the lung volume in actual communication with the airways) were significantly lower in former BPD infants compared to controls. However, these differences became non-significant after normalization to body weight.</p> <p>Conclusions</p> <p>Although somatic growth and the development of some lung functional parameters lag in former BPD infants, the lung function of such infants appears to develop in line with that of non-BPD infants when a body weight correction is applied. Longitudinal lung function testing of preterm infants after discharge from hospital may help to identify former BPD infants at risk of incomplete recovery of respiratory function; such infants are at risk of later respiratory problems.</p

    Predicting hospital cost in CKD patients through blood chemistry values

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    <p>Abstract</p> <p>Background</p> <p>Controversy exists in predicting costly hospitalization in patients with chronic kidney disease and co-morbid conditions. We therefore tested associations between serum chemistry values and the occurrence of in-patient hospital costs over a thirteen month study period. Secondarily, we derived a linear combination of variables to estimate probability of such occurrences in any patient.</p> <p>Method</p> <p>We calculated parsimonious values for select variables associated with in-patient hospitalization and compared sensitivity and specificity of these models to ordinal staging of renal disease.</p> <p>Data from 1104 de-identified patients which included 18 blood chemistry observations along with complete claims data for all medical expenses.</p> <p>We employed multivariable logistic regression for serum chemistry values significantly associated with in-patient hospital costs exceeding $3,000 in any single month and contrasted those results to other models by ROC area curves.</p> <p>Results</p> <p>The linear combination of weighted Z scores for parathyroid hormone, phosphorus, and albumin correlated with in-patient hospital care at p < 0.005. ROC curves derived from weighted variables of age, eGFR, hemoglobin, albumin, creatinine, and alanine aminotransferase demonstrated significance over models based on non-weighted Z scores for those same variables or CKD stage alone. In contrast, the linear combination of weighted PTH, PO4 and albumin demonstrated better prediction, but not significance over non-weighted Z scores for PTH alone.</p> <p>Conclusion</p> <p>Further study is justified to explore indices that predict costly hospitalization. Such metrics could assist Accountable Care Organizations in evaluating risk adjusted compensation for providers.</p

    Temperature responses of Rubisco from Paniceae grasses provide opportunities for improving C3 photosynthesis.

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    Enhancing the catalytic properties of the CO2-fixing enzyme Rubisco is a target for improving agricultural crop productivity. Here, we reveal extensive diversity in the kinetic response between 10 and 37 °C by Rubisco from C3 and C4 species within the grass tribe Paniceae. The CO2 fixation rate (kcatc) for Rubisco from the C4 grasses with nicotinamide adenine dinucleotide (NAD) phosphate malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PCK) photosynthetic pathways was twofold greater than the kcatc of Rubisco from NAD-ME species across all temperatures. The declining response of CO2/O2 specificity with increasing temperature was less pronounced for PCK and NADP-ME Rubisco, which would be advantageous in warmer climates relative to the NAD-ME grasses. Modelled variation in the temperature kinetics of Paniceae C3 Rubisco and PCK Rubisco differentially stimulated C3 photosynthesis relative to tobacco above and below 25 °C under current and elevated CO2. Amino acid substitutions in the large subunit that could account for the catalytic variation among Paniceae Rubisco are identified; however, incompatibilities with Paniceae Rubisco biogenesis in tobacco hindered their mutagenic testing by chloroplast transformation. Circumventing these bioengineering limitations is critical to tailoring the properties of crop Rubisco to suit future climates
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