bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal learning in the honeybee,Apis mellifera
Authors: Hammer Tobin J. , Hata Curtis , Nieh James C. 
Published: November 2009

SUMMARYHoneybee foragers are exposed to thermal stimuli when collecting food outside and receiving food rewards inside the nest. In both contexts, there is an opportunity for foragers to associate warmth with food rewards. However, honeybee thermal learning is poorly understood. Using an associative learning paradigm (the proboscis extension reflex), we show that honeybees can learn to associate a nectar reward with a heated stimulus applied to the antenna to mimic natural contact with a warm flower or nectar-offering forager. Conditioning with longer inter-trial intervals (ITI) significantly improved learning acquisition. We also trained bees to discriminate between temperatures above (warm) and below (cold) ambient air temperature. Learning acquisition improved by 38% per 10°C increase in absolute stimulus intensity (difference between the rewarded temperature and unrewarded ambient air temperature). However, bees learned positive temperature (warm) significantly better than negative temperature (cold) differences, approximately twice as well for 10°C as compared with a −10°C difference. Thus, thermosensation, a sensory modality that is relatively unexplored in honeybees, could play a role in the acquisition of information from nestmates (social learning) and in foraging decisions influenced by associations between floral temperature and nectar rewards.
The responses of zebrafish (Danio rerio) to high external ammonia and urea transporter inhibition: nitrogen excretion and expression of rhesus glycoproteins and urea transporter proteins
Authors: Braun Marvin H. , Steele Shelby L. , Perry Steve F. 
Published: November 2009

SUMMARYWhile adult zebrafish, Danio rerio, possess ammonia and urea transporters (Rh and UT proteins, respectively) in a number of tissues, they are most heavily concentrated within the gills. UT has a diffuse expression pattern within Na+-K+-ATPase (NKA)-type mitochondrion-rich cells and Rh proteins form a network similar to the arrangement seen in pufferfish gills (Nakada et al., 2007b). Rhag expression appeared to be limited to the pillar cells lining the blood spaces of the lamellae while Rhbg was localized to the outer layer of both the lamellae and the filament, upon the pavement cells. Exposure to high external ammonia (HEA) or phloretin increased tissue levels of ammonia and urea, respectively, in adult and juvenile zebrafish; however, the responses to these stressors were age dependent. HEA increased mRNA levels for a number of Rh proteins in embryos and larvae but did not elicit similar effects in adult gills, which appear to compensate for the unfavourable ammonia excretory gradient by increasing expression of V-type H+-ATPase. Phloretin exposure increased UT mRNA levels in embryos and larvae but was without effect in adult gill tissue. Surprisingly, in both adults and juveniles, HEA increased the mRNA expression of UT and phloretin increased the mRNA expression of Rh proteins. These results imply that, in zebrafish, there may be a tighter link between ammonia and urea excretion than is thought to occur in most teleosts.
Cell kinetics of the marine spongeHalisarca caeruleareveal rapid cell turnover and shedding
Authors: De Goeij J. M. , De Kluijver A. , Van Duyl F. C. , Vacelet J. , Wijffels R. H. , De Goeij A. F. P. M. , Cleutjens J. P. M. , Schutte B. 
Published: November 2009

SUMMARYThis study reveals the peculiar in vivo cell kinetics and cell turnover of the marine sponge Halisarca caerulea under steady-state conditions. The tropical coral reef sponge shows an extremely high proliferation activity, a short cell cycle duration and massive cell shedding. Cell turnover is predominantly confined to a single cell population, i.e. the choanocytes, and in this process apoptosis only plays a minor role. To our knowledge, such fast cell kinetics under steady-state conditions, with high turnover by shedding in the absence of apoptosis, has not been observed previously in any other multicellular organism. The duration of the cell cycle in vivo resembles that of unicellular organisms in culture. Morphological and histochemical studies demonstrate compartmentalization of choanocytes in the sponge tissue, which corresponds well with its remarkable cellular kinetics. Coral reef cavity sponges, like H. caerulea, inhabit low nutrient tropical waters, forcing these organisms to filter large volumes of water and to capture the few nutrients efficiently. Under these oligotrophic conditions, a high cell turnover may be considered as a very useful strategy, preventing permanent damage to the sponge by environmental stress. Halisarca caerulea maintains its body mass and keeps its food uptake system up to date by constantly renewing its filter system. We conclude that studies on cell kinetics and functional morphology provide new and essential information on the growth characteristics and the regulation of sponge growth in vivo as well as in vitro and the role of choanocytes in tissue homeostasis.
The intestinal response to feeding in seawater gulf toadfish, Opsanus beta, includes elevated base secretion and increased epithelial oxygen consumption
Authors: Taylor J. R. , Grosell M. 
Published: November 2009

SUMMARY
Intestinal HCO3− secretion is essential to marine teleost fish osmoregulation and comprises a considerable source of base efflux attributable to both serosal HCO3− and endogenous CO2 hydration. The role of intestinal HCO3− secretion in dynamic acid—base balance regulation appears negligible in studies of unfed fish, but evidence of high intestinal fluid [HCO3−] in fed marine teleosts led us to investigate the source of this HCO3− and its potential role in offsetting the postprandial ‘alkaline tide’ commonly associated with digestion. Specifically, we hypothesized that elevated metabolic rate and thus endogenous CO2 production by intestinal tissue as well as increased transepithelial intestinal HCO3− secretion occur post-feeding and offset a postprandial alkaline tide. To test these hypotheses changes in HCO3− secretion and O2 consumption by gulf toadfish (Opsanus beta) isolated intestine were quantified 0, 3, 6, 12, 24 and 48 h post-feeding. Intestinal tissue of unfed fish in general showed high rates of HCO3− secretion (15.5 μmol g−1 h−1) and O2 consumption (8.9 μmol g−1 h−1). Furthermore, postprandial increases in both intestinal HCO3− secretion and O2 consumption (1.6- and 1.9-fold peak increases, respectively) were observed. Elevated intestinal HCO3− secretion rates preceded and outlasted those of O2 consumption, and occurred at a magnitude and duration sufficient to account for the lack of alkaline tide. The dependence of these high rates of postprandial intestinal base secretion on serosal HCO3− indicates transepithelial HCO3− transport increases disproportionately more than endogenous CO2 production. The magnitude of postprandial intestinal HCO3− secretion indicates the intestine certainly is capable of postprandial acid#x02014;base balance regulation.
Fatty acid composition of pectoralis muscle membrane, intramuscular fat stores and adipose tissue of migrant and wintering white-throated sparrows (Zonotrichia albicollis)
Authors: Klaiman J. M. , Price E. R. , Guglielmo C. G. 
Published: November 2009

SUMMARY
The fatty acid composition of muscle membrane phospholipids and fat stores may affect migration performance in birds. The purpose of this study was to investigate seasonal changes in the fatty acid composition of (1) pectoralis muscle phospholipids, (2) intramuscular triglyceride stores and (3) adipose tissue triglycerides in free-living white-throated sparrows (Zonotrichia albicollis). During migratory seasons there was an increase in the n-6:n-3 ratio of muscle membrane phospholipid fatty acids without a change in the proportion of unsaturated fatty acids. This change was driven mainly by an increase in the proportion of 18:2n-6 and a decrease in the proportion of 22:6n-3. An increase in the proportion of 18:2n-6 was also observed in the intramuscular and adipose tissue triglyceride stores during the migratory seasons. These increases in 18:2n-6 were offset by a decrease in 16:0; resulting in an elevated proportion of unsaturated fatty acids and elevated double bond index in both fat stores of migrants. The elevated levels of 18:2n-6 in migrant fat stores indicates a high dietary component of this fatty acid, as white-throated sparrows feed mainly on tree seeds and some insects during migration and may not have access to a diet high in n-3 fatty acids. We suspect that elevated dietary levels of 18:2n-6 also caused the observed increases in the proportion of this fatty acid in muscle phospholipids. Overall, we conclude that seasonal changes in adipose and muscle fatty acid composition are likely attributable to diet more than other factors such as migratory exercise or mitochondrial density.
Characterization of the sea bass melanocortin 5 receptor: a putative role in hepatic lipid metabolism
Authors: Sánchez E. , Rubio V. C. , Cerdá-Reverter J. M. 
Published: November 2009

SUMMARYThe melanocortin 5 receptor (MC5R) plays a key role in the regulation of exocrine secretion in mammalian species. This receptor has also been characterized in some fish species but its function is unknown. We report the molecular and pharmacological characterization, as well as the tissue expression pattern, of sea bass MC5R. Cloning of five active alleles showing different levels of sensitivity to endogenous melanocortin and one non-functional allele demonstrate the allelic complexity of the MC5R locus. The sea bass receptor was activated by all the melanocortins tested, with ACTH and desacetyl-MSH and β-MSH showing the lowest efficiency. The acetylation of the MSH isoforms seems to be critical for the effectiveness of the agonist. Agouti-related protein had no effect on basal or agonist-stimulated activation of the receptor. SbMC5R was mainly expressed in the brain but lower expression levels were found in several peripheral tissues, including liver. Progressive fasting did not induce up- or downregulation of hypothalamic MC5R expression, suggesting that central MC5R is not involved in the regulation of food intake in the sea bass. MTII, a sbMC5R agonist, stimulated hepatic lipolysis in vitro, measured as free fatty acid release into the culture medium after melanocortin agonist exposure of liver fragments, suggesting that MC5R is involved in the regulation of hepatic lipid metabolism. Taken together, the data suggest that different allelic combinations may confer differential sensitivity to endogenous melanocortin in tissues where MC5R is expressed and, by extension, in hepatic lipid metabolism.
Ventilatory and cardiovascular actions of centrally and peripherally administered trout pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) in the unanaesthetized trout
Authors: Le Mével J.-C. , Lancien F. , Mimassi N. , Conlon J. M. 
Published: November 2009

SUMMARYIn mammals, pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are involved in cardiovascular and respiratory regulation. Several studies have demonstrated the presence of PACAP, VIP and their receptors in various tissues of teleost fish, including the brain, but little is known about their respiratory and cardiovascular effects. The present study was undertaken to compare the central and peripheral actions of graded doses (25-100 pmol) of trout PACAP and trout VIP on ventilatory and cardiovascular variables in the unanaesthetized rainbow trout. Compared with vehicle, only intracerebroventricular injection of PACAP significantly (P&lt;0.05) elevated the ventilation frequency and the ventilation amplitude, but both peptides significantly increased the total ventilation (). However, the maximum hyperventilatory effect of PACAP was approximately 2.5-fold higher than the effect of VIP at the 100 pmol dose (PACAP, =+5407±921 arbitrary units, a.u.; VIP, =+2056±874 a.u.; means ± s.e.m.). When injected centrally, only PACAP produced a significant increase in mean dorsal aortic blood pressure (PDA) (100 pmol: +21%) but neither peptide affected heart rate (fH). Intra-arterial injections of either PACAP or VIP were without effect on the ventilatory variables. PACAP was without significant action on PDA and fH while VIP significantly elevated PDA (100 pmol: +36%) without changing fH. In conclusion, the selective central hyperventilatory actions of exogenously administered trout PACAP, and to a lesser extent VIP, suggest that the endogenous peptides may be implicated in important neuroregulatory functions related to the central control of ventilation in trout.
Ultimate Load of Barrel-Vault Space Trusses Shaped by Post-Tensioning
Authors: Karbaschi M.E. , Dehdashti G. , Fiouz A. 
Published: November 2009

This paper presents the results of nonlinear analysis to predict the ultimate load of a barrel-vault space truss shaped by post-tensioning. Experimental study on shape formation, load tests to determine the ultimate load of the post-tensioned barrel-vault space truss and individual compression tests on members to determine their buckling load have been carried out in previous research. The nonlinear analysis carried out herein uses the reduced stiffness of various members according to member test results to determine the ultimate load behavior of the model barrel-vault space truss. The paper also presents the ultimate load behavior of large-span barrel-vault space trusses, taking into account the buckling of their members. As a result, it is shown that these structures can be used to cover large spans with sufficient structural stiffness. Lastly, some design aid diagrams are proposed.
A 25-Year Prospective Study of Plasma Adiponectin and Leptin Concentrations and Prostate Cancer Risk and Survival
Authors: Li Haojie , Stampfer Meir J , Mucci Lorelei , Rifai Nader , Qiu Weiliang , Kurth Tobias , Ma Jing 
Published: November 2009

AbstractBackground: Adipocytokines may mediate the association between adiposity and lethal prostate cancer outcomes.Methods: In the Physicians’ Health Study, we prospectively examined the association of prediagnostic plasma concentrations of adiponectin and leptin with risk of developing incident prostate cancer (654 cases diagnosed 1982–2000 and 644 age-matched controls) and, among cases, risk of dying from prostate cancer by 2007.Results: Adiponectin concentrations were not associated with risk of overall prostate cancer. However, men with higher adiponectin concentrations had lower risk of developing high-grade or lethal cancer (metastatic or fatal disease). The relative risk (95% CI) comparing the highest quintile to the lowest (Q5 vs Q1) was 0.25 (95% CI 0.07–0.87; Ptrend = 0.02) for lethal cancer. Among all the cases, higher adiponectin concentrations predicted lower prostate cancer–specific mortality [hazard ratio (HR)Q5 vs Q1= 0.39; 95% CI 0.17–0.85; Ptrend = 0.02], independent of body mass index (BMI), plasma C-peptide (a marker of insulin secretion), leptin, clinical stage, and tumor grade. This inverse association was apparent mainly among men with a BMI ≥25 kg/m2 (HRQ5 vs Q1= 0.10; 95% CI 0.01–0.78; Ptrend = 0.02), but not among men of normal weight (Ptrend = 0.51). Although the correlation of leptin concentrations with BMI (r = 0.58, P &lt; 0.001) was stronger than that of adiponectin (r = −0.17, P &lt; 0.001), leptin was unrelated to prostate cancer risk or mortality.Conclusions: Higher prediagnostic adiponectin (but not leptin) concentrations predispose men to a lower risk of developing high-grade prostate cancer and a lower risk of subsequently dying from the cancer, suggesting a mechanistic link between obesity and poor prostate cancer outcome.
Interfacial properties of polyelectrolyte complexes incorporating kraft lignin 10th EWLP, Stockholm, Sweden, August 25–28, 2008
Authors: Shulga Galia , Shakels Vadims , Aniskevicha Olga , Zakharova Julia , Skudra Sanita 
Published: November 2009

Abstract
Surface tension of kraft lignin (KL) and KL/poly(N,N-dimethylaminoethyl methacrylate) mixtures, with different composition at the air-water interface depending on pH and temperature, was measured. It was found that the surface activity of both KL and the reaction mixtures grows with decreasing pH and increasing temperature. At the same time, the surface activity of the KL/poly(N,N-dimethylaminoethyl methacrylate) reaction mixture, irrespective of its composition under the same environment conditions, considerably exceeds the surface activity of KL, indicating the synergetic effect governed by the peculiarities of the polymeric structure of the formed soluble particles of the polyelectrolyte complex.
A Decade of Controversy: Balancing Policy With Evidence in the Regulation of Prescription Drug Advertising
Authors: Frosch Dominick L. , Grande David , Tarn Derjung M. , Kravitz Richard L. 
Published: November 2009

Direct-to-consumer advertising (DTCA) of prescription drugs has remained controversial since regulations were liberalized by the Food and Drug Administration in 1997. We reviewed empirical evidence addressing the claims made in the policy debate for and against DTCA. This advertising has some benefits, but significant risks are evident as well, magnified by the prominence of DTCA in population-level health communications. To minimize potential harm and maximize the benefits of DTCA for population health, the quality and quantity of information should be improved to enable consumers to better self-identify whether treatment is indicated, more realistically appraise the benefits, and better attend to the risks associated with prescription drugs. We propose guidelines for improving the utility of prescription drug advertising.
Childhood Cognition and Risk Factors for Cardiovascular Disease in Midadulthood: The 1958 British Birth Cohort Study
Authors: Power Chris , Jefferis Barbara J. M. H. , Manor Orly 
Published: November 2009

Objectives. We sought to establish whether associations between childhood cognition and risk factors for cardiovascular disease in adulthood are explained by common causes, or adult social position or health behavior. Methods. We analyzed associations between cognition at age 11 and cardiovascular disease risk factors at age 45 in the 1958 British birth cohort (n = 9377), with and without adjustment for covariates. Results. General ability was inversely associated with systolic and diastolic blood pressure, glycosylated hemoglobin, triglycerides (in women), body mass index, and waist circumference. Systolic blood pressure decreased by 0.47 mm Hg (95% confidence interval [CI] = −0.90, –0.05) for a 1-standard-deviation increase in ability. Separate adjustment for social class at birth, education level by adulthood, adult social class, and health behaviors reduced the associations respectively by 14% to 34%, 36% to 50%, 14% to 36%, and 24% to 73%. Full adjustment reduced associations between ability and risk factors at age 45 years by 43% to 92%, abolishing all associations. Conclusions. Increments across the distribution of childhood cognition are associated with improvements in cardiovascular risk profile in midlife, with associations primarily mediated through adult health behavior and social destinations.
Disability Trends Among Older Americans: National Health and Nutrition Examination Surveys, 1988–1994 and 1999–2004
Authors: Seeman Teresa E. , Merkin Sharon S. , Crimmins Eileen M. , Karlamangla Arun S. 
Published: November 2009

Objectives. We investigated trends in disability among older Americans from 1988 through 2004 to test the hypothesis that more recent cohorts show increased burdens of disability. Methods. We used data from 2 National Health and Nutrition Examination Surveys (1988–1994 and 1999–2004) to assess time trends in basic activities of daily living, instrumental activities, mobility, and functional limitations for adults aged 60 years and older. We assessed whether changes could be explained by sociodemographic, body weight, or behavioral factors. Results. With the exception of functional limitations, significant increases in each type of disability were seen over time among respondents aged 60 to 69 years, independent of sociodemographic characteristics, health status, relative weight, and health behaviors. Significantly greater increases occurred among non-Whites and persons who were obese or overweight (2 of the fastest-growing subgroups within this population). We detected no significant trends among respondents aged 70 to 79 years; in the oldest group (aged ≥ 80 years), time trends suggested lower prevalence of functional limitations among more recent cohorts. Conclusions. Our results have significant and sobering implications: older Americans face increased disability, and society faces increased costs to meet the health care needs of these disabled Americans.
Correlates and Consequences of Venous Thromboembolism: The Iowa Women's Health Study
Authors: Lutsey Pamela L. , Virnig Beth A. , Durham Sara B. , Steffen Lyn M. , Hirsch Alan T. , Jacobs David R. , Folsom Aaron R. 
Published: November 2009

Objectives. We sought to document incidence, case-fatality, and recurrence rates of venous thromboembolism (VTE) in women and to explore the relationship of demographic, lifestyle, and anthropometric factors to VTE incidence. Methods. Data from participants aged 55 to 69 years in the Iowa Women's Health Study were linked to Medicare data for 1986 through 2004 (n = 40 377) to identify hospitalized VTE patients. Results. A total of 2137 women developed VTE, yielding an incidence rate of 4.04 per 1000 person-years. The 28-day case-fatality rate was 7.7%, and the 1-year recurrence rate was 3.4%. Educational attainment, physical activity, and age at menopause were inversely associated with VTE. Risk of secondary (particularly cancer-related) VTE was higher among smokers than among those who had never smoked. Body mass index, waist circumference, waist-to-hip ratio, height, and diabetes were positively associated with VTE risk. Hormone replacement therapy use was associated with increased risk of idiopathic VTE. Conclusions. VTE is a significant source of morbidity and mortality in older women. Risk was elevated among women who were smokers, physically inactive, overweight, and diabetic, indicating that lifestyle contributes to VTE risk.
Association of Race, Substance Abuse, and Health Insurance Coverage With Use of Highly Active Antiretroviral Therapy Among HIV-Infected Women, 2005
Authors: Lillie-Blanton Marsha , Stone Valerie E. , Snow Jones Alison , Levi Jeffrey , Golub Elizabeth T. , Cohen Mardge H. , Hessol Nancy A. , Wilson Tracey E. 
Published: November 2009

Objectives. We examined racial/ethnic disparities in highly active antiretroviral therapy (HAART) use and whether differences are moderated by substance use or insurance status, using data from the Women's Interagency HIV Study (WIHS). Methods. Logistic regression examined HAART use in a longitudinal cohort of women for whom HAART was clinically indicated in 2005 (N = 1354). Results. Approximately 3 of every 10 eligible women reported not taking HAART. African American and Hispanic women were less likely than were White women to use HAART. After we adjusted for potential confounders, the higher likelihood of not using HAART persisted for African American but not for Hispanic women. Uninsured and privately insured women, regardless of race/ethnicity, were less likely than were Medicaid enrollees to use HAART. Although alcohol use was related to HAART nonuse, illicit drug use was not. Conclusions. These findings suggest that expanding and improving insurance coverage should increase access to antiretroviral therapy across racial/ethnic groups, but it is not likely to eliminate the disparity in use of HAART between African American and White women with HIV/AIDS.