37 research outputs found

    Sessile droplet evaporation on superheated superhydrophobic surfaces

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    This fluid dynamics video depicts the evaporation of sessile water droplets placed on heated superhydrophobic (SH) surfaces of varying cavity fraction, F_c, and surface temperature, T_s, above the saturation temperature, T_sat. Images were captured at 10,000 FPS and are played back at 30 FPS in this video. Teflon-coated silicon surfaces of F_c = 0, 0.5, 0.8, and 0.95 were used for these experiments. T_s ranging from 110{\deg}C to 210{\deg}C were studied. The video clips show how the boiling behavior of sessile droplets is altered with changes in surface microstructure. Quantitative results from heat transfer rate experiments conducted by the authors are briefly discussed near the end of the video.Comment: videos include

    Bedrock Topography Waterloo Quadrangle, Monroe County, Illinois

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    Relief shown by contours and spot heights"Based on field work and data compilation by S. Panno, B. Denny, and J. Angel, 2007.""Digital cartography by J. Domier, S. Geegan, and S. Radil, Illinois State Geological Survey."Includes text, index to adjoining quadrangles, and location mapIncludes bibliographical reference

    Signal peptide mutations in RANK prevent downstream activation of NF-ÎșB

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    Familial expansile osteolysis and related disorders are caused by heterozygous tandem duplication mutations in the signal peptide region of the gene encoding receptor activator of NF-ÎșB (RANK), a receptor critical for osteoclast formation and function. Previous studies have shown that overexpression of these mutant proteins causes constitutive activation of NF-ÎșB signaling in vitro, and it has been assumed that this accounts for the focal osteolytic lesions that are seen in vivo. We show here that constitutive activation of NF-ÎșB occurred in HEK293 cells overexpressing wild-type or mutant RANK but not in stably transfected cell lines expressing low levels of each RANK gene. Importantly, only cells expressing wild-type RANK demonstrated ligand-dependent activation of NF-ÎșB. When overexpressed, mutant RANK did not localize to the plasma membrane but localized to extensive areas of organized smooth endoplasmic reticulum, whereas, as expected, wild-type RANK was detected at the plasma membrane and in the Golgi apparatus. This intracellular accumulation of the mutant proteins is probably the result of lack of signal peptide cleavage because, using two in vitro translation systems, we demonstrate that the mutations in RANK prevent cleavage of the signal peptide. In conclusion, signal peptide mutations lead to accumulation of RANK in the endoplasmic reticulum and prevent direct activation by RANK ligand. These results strongly suggest that the increased osteoclast formation/activity caused by these mutations cannot be explained by studying the homozygous phenotype alone but requires further detailed investigation of the heterozygous expression of the mutant RANK proteins. © 2011 American Society for Bone and Mineral Researc

    RANK-Dependent Autosomal Recessive Osteopetrosis: Characterization of Five New Cases With Novel Mutations

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    Autosomal recessive osteopetrosis (ARO) is a genetically heterogeneous disorder attributed to reduced bone resorption by osteoclasts. Most human AROs are classified as osteoclast rich, but recently two subsets of osteoclast-poor ARO have been recognized as caused by defects in either TNFSF11 or TNFRSF11A genes, coding the RANKL and RANK proteins, respectively. The RANKL/RANK axis drives osteoclast differentiation and also plays a role in the immune system. In fact, we have recently reported that mutations in the TNFRSF11A gene lead to osteoclast-poor osteopetrosis associated with hypogammaglobulinemia. Here we present the characterization of five additional unpublished patients from four unrelated families in which we found five novel mutations in the TNFRSF11A gene, including two missense and two nonsense mutations and a single-nucleotide insertion. Immunological investigation in three of them showed that the previously described defect in the B cell compartment was present only in some patients and that its severity seemed to increase with age and the progression of the disease. HSCT performed in all five patients almost completely cured the disease even when carried out in late infancy. Hypercalcemia was the most important posttransplant complication. Overall, our results further underline the heterogeneity of human ARO also deriving from the interplay between bone and the immune system, and highlight the prognostic and therapeutic implications of the molecular diagnosis. © 2012 American Society for Bone and Mineral Researc

    Using direct observations on multiple occasions to measure household food availability among low-income Mexicano residents in Texas colonias

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    BACKGROUND: It has been recognized that the availability of foods in the home are important to nutritional health, and may influence the dietary behavior of children, adolescents, and adults. It is therefore important to understand food choices in the context of the household setting. Considering their importance, the measurement of household food resources becomes critical.Because most studies use a single point of data collection to determine the types of foods that are present in the home, which can miss the change in availability within a month and when resources are not available, the primary objective of this pilot study was to examine the feasibility and value of conducting weekly in-home assessments of household food resources over the course of one month among low-income Mexicano families in Texas colonias. METHODS: We conducted five in-home household food inventories over a thirty-day period in a small convenience sample; determined the frequency that food items were present in the participating households; and compared a one-time measurement with multiple measurements.After the development and pre-testing of the 252-item culturally and linguistically- appropriate household food inventory instrument that used direct observation to determine the presence and amount of food and beverage items in the home (refrigerator, freezer, pantry, elsewhere), two trained promotoras recruited a convenience sample of 6 households; administered a baseline questionnaire (personal info, shopping habits, and food security); conducted 5 in-home assessments (7-day interval) over a 30-day period; and documented grocery shopping and other food-related activities within the previous week of each in-home assessment. All data were collected in Spanish. Descriptive statistics were calculated for mean and frequency of sample characteristics, food-related activities, food security, and the presence of individual food items. Due to the small sample size of the pilot data, the Friedman Test and Kendall's W were used to assess the consistency of household food supplies across multiple observations. RESULTS: Complete data were collected from all 6 Mexicano women (33.2y +/- 3.3; 6.5 +/- 1.5 adults/children in household (HH); 5 HH received weekly income; and all were food insecure. All households purchased groceries within a week of at least four of the five assessments. The weekly presence and amounts of fresh and processed fruits and vegetables, dairy, meats, breads, cereals, beverages, and oils and fats varied. Further, the results revealed the inadequacy of a one-time measurement of household food resources, compared with multiple measures. The first household food inventory as a one-time measure would have mistakenly identified at least one-half of the participant households without fresh fruit, canned vegetables, dairy, protein foods, grains, chips, and sugar-sweetened beverages. CONCLUSIONS: This study highlights the value of documenting weekly household food supplies, especially in households where income resources may be more volatile. Clearly, the data show that a single HFI may miss the changes in availability--presence and amount--that occur among low-income Mexicano households who face challenges that require frequent purchase of foods and beverages. Use of multiple household food inventories can inform the development and implementation of nutrition-related policies and culturally sensitive nutrition education programs

    The stigma turbine:A theoretical framework for conceptualizing and contextualizing marketplace stigma

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    Stigmas, or discredited personal attributes, emanate from social perceptions of physical characteristics, aspects of character, and “tribal” associations (e.g., race; Goffman 1963). Extant research emphasizes the perspective of the stigma target, with some scholars exploring how social institutions shape stigma. Yet the ways stakeholders within the socio-commercial sphere create, perpetuate, or resist stigma remain overlooked. We introduce and define marketplace stigma as the labeling, stereotyping, and devaluation by and of commercial stakeholders (consumers, companies and their employees, stockholders, institutions) and their offerings (products, services, experiences). We offer the Stigma Turbine (ST) as a unifying conceptual framework that locates marketplace stigma within the broader sociocultural context, and illuminates its relationship to forces that exacerbate or blunt stigma. In unpacking the ST, we reveal the critical role market stakeholders can play in (de)stigmatization, explore implications for marketing practice and public policy, and offer a research agenda to further our understanding of marketplace stigma and stakeholder welfare

    School Transitions and Adjustment During Early Adolescence

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    The aim of this investigation was to determine the impact of the timing and number of school transitions on young adolescents’ subsequent adjustment. Three groups of adolescents (total N = 253) were compared: those making a single early school transition prior to sixth grade, those making a single later transition prior to seventh grade, and those making a double transition prior to both sixth and seventh grades. Adjustment was assessed in terms of course grades and self-image. Negative effects were found for both early and repeated school transitions, with the double transition being especially debilitating. In addition, effects were seen primarily with course grades. Few gender differences were observed in the response to early and double transitions, but those that emerged suggest that girls may be more adversely affected than boys

    Two-Phase Flow Pressure Drop in Superhydrophobic Channels

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    Superhydrophobic surfaces promote dropwise condensation, which increases the rate of thermal transport, making them desirable for use in condensers. Adiabatic two-phase flow loops have been constructed to gain insight into the hydrodynamics of two-phase systems, laying the groundwork for further study of condensing flow on superhydrophobic surfaces. A two-phase flow loop to measure pressure drop and visualize the flow patterns of two-phase flow in superhydrophobic channels relative to classical hydrophilic and hydrophobic surfaces was built and validated. Good agreement was found between observed pressure drops and theoretical and experimental correlations in the literature

    A comparison between the effects of hydrophobic and hydrophilic statins on osteoclast function in vitro and ovariectomy-induced bone loss in vivo

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    Statins potently inhibit 3-hydroxy-3-methylglutaryl-coenzyme A reductase, blocking downstream biosynthesis of isoprenoid lipids and causing inhibition of protein prenylation. Prenylated signaling molecules are essential for osteoclast function, consistent with our previous observation that mevastatin can inhibit osteoclast activity in vitro. Several reports suggest that statins may also have an anabolic effect on bone and stimulate osteoblast differentiation. This study sought to determine the effects of both hydrophobic and hydrophilic statins, particularly rosuvastatin (RSV), on osteoclast function in vitro and in vivo. All statins tested (RSV, pravastatin [PRA], cerivastatin [CER], and simvastatin [SIM]) caused accumulation of unprenylated Rap-1A in rabbit osteoclast-like cells and J774 macrophages in vitro and inhibited osteoclast-mediated resorption. The order of potency for inhibiting prenylation in vitro (at concentrations of 0.01-50 muM) was CER&gt;SIM&gt;RSV&gt;PRA. The most potent hydrophilic statin (CER, 0.05 and 0.3 mg/kg) inhibited prenylation in rabbit osteoclasts 24 hours after a single subcutaneous (s.c.) injection more effectively than the most potent hydrophobic statin (RSV, 20 mg/kg). However, in a mouse model of osteoporosis, s.c. 0.05 mg/kg/day CER and 2 or 20 mg/kg/day RSV for 3 weeks only mildly prevented loss of cortical and trabecular bone induced by ovariectomy. No increase in bone formation rate was observed with statin treatment, suggesting that this effect was due to inhibition of osteoclast-mediated resorption rather than increased bone formation.</p
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