Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Heavier

  • kg heavier

  • Terms modified by Heavier

  • heavier baby
  • heavier group

  • Selected Abstracts

    Risk factors of Hong Kong Chinese patients with coronary heart disease

    Sek Ying Chair RN
    Aims and objectives., The aims of the study were to describe the level of modifiable coronary risk factors and to explore the relationships among these risk factors in patients with coronary heart disease. Background., Appropriate patient education and therapies for coronary risk reduction will prevent recurrent cardiac events and progression of coronary heart disease. Therefore, having knowledge of the risk profile of these patients is essential so that appropriate contents and focus of patient educations can be developed. Methods., Coronary heart disease patients admitted for cardiac catheterization at the two studied hospitals in Hong Kong were recruited for this study. Demographic date and risk factors of blood pressure, smoking status, body mass index, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and exercise level were collected from subjects as well as from medical records for analysis. Results., The body mass index was significantly different among non-smoker, ex-smoker and smoker (p = 0·027). Non-smokers had the highest body mass index but smokers had the lowest body mass index among the three groups in this study. Physical inactivity, overweight and hypercholesterolaemia were the risk factors seen in about 50% of the studied subjects. Body mass index correlated positively with systolic blood pressure but negatively correlated with high-density lipoprotein cholesterol and hour of exercise. Conclusions., Heavier subjects had a higher systolic blood pressure but a lower level of high-density lipoprotein cholesterol. Heavier subjects also exercised less. The study results provided additional information on the database of the risk profile among Hong Kong cardiac patients. Relevance to clinical practice., Hypertension, obesity, physical inactivity, abnormal serum lipid levels and smoking are the modifiable risk factors for coronary heart diseases. As physical inactivity, overweight and hypercholesterolaemia were found in half of the studied subjects, the importance of risk factors control should be addressed to this group of patients. Nurses should be aware of their educator role to provide appropriate education to coronary heart disease patients with the focus on reducing and controlling of cardiac risk factors, which has been shown to be effective in reducing the progress of disease. [source]

    Maternal exposure to first-trimester sunshine is associated with increased birth weight in human infants

    Karen Tustin
    Abstract Two alternative hypotheses have been generated to account for seasonal variation in the birth weight of human infants born in industrialized countries. First, it has been hypothesized that low ambient temperature during the second trimester of gestation decreases birth weight. Second, it has been hypothesized that exposure to bright sunshine during the first trimester increases birth weight. We tested these two hypotheses to determine which, if either, accounted for seasonal variation in birth weight of full-term infants. Birth weight data, collected over a 5-year period, were analyzed as a function of peak and trough sunshine and ambient temperature. Although there was no effect of ambient temperature during any trimester on birth weight, infants whose mothers were exposed to peak sunshine during their first trimester were born significantly heavier than infants whose mothers experienced trough levels of sunshine during the same trimester. Furthermore, infants whose mothers were exposed to trough levels of sunshine during their second and third trimesters were born significantly heavier than infants whose mothers were exposed to peak levels of sunshine during the same trimesters. We hypothesize that high levels of sunshine during early gestation may increase the level of insulin-like growth factor (IGF)-1, facilitating prenatal growth. © 2004 Wiley Periodicals, Inc. Dev Psychobiol 45: 221,230, 2004. [source]

    Ready to drinks are associated with heavier drinking patterns among young females

    Abstract Aim. To report patterns of use of ready to drinks (RTDs) and to assess if RTD consumers have heavier drinking patterns. RTDs were introduced in 1995. Method. Data from a general population sample of 7201 respondents aged 14,65 years, in New Zealand in 2004, were modelled. Results. Nineteen per cent of respondents consumed RTDs. Respondents aged 14,17 and 18,24 years and females were the largest consumers of RTDs. Compared to beer, wine or spirits, being an RTD consumer predicted (1) higher typical occasion quantities for respondents aged 14,17, 18,24 and 25+ years and (2) heavier drinking for those aged 14,17 and 18,24 years. When amounts of beverages consumed were modelled, quantity of RTDs predicted higher typical occasion quantities among females of all ages. Among males beer was more predictive. Similar results were found for the heavier drinking measure. For 14,17-year-old females, RTDs consumption predicted higher annual frequency, but for the other females and males the amount of wine or beer consumed predicted higher frequency. Conclusion. RTDs were most popular among young people aged 14,17 years, and females. RTDs predicted higher typical occasion alcohol consumption and heavier drinking better than any other beverage for females aged 14,17 years. For the other age and gender groups, other beverages predicted higher quantity and frequency consumption. [source]

    New role for majors in Atta leafcutter ants

    Abstract 1.,Atta (Hymenoptera: Formicidae) leafcutter ants display the most polymorphic worker caste system in ants, with different sizes specialising in different tasks. The largest workers (majors) have large, powerful mandibles and are mainly associated with colony defence. 2.,Majors were observed cutting fallen fruit and this phenomenon was investigated in the field by placing mango fruit near natural Atta laevigata and Atta sexdens colonies in São Paulo State, Brazil. 3.,Ants cutting the fruit were significantly heavier (mean = 49.1 mg, SD = 11.1 mg, n= 90) than the ants carrying the fruit back to the nest (mean = 20.9 mg, SD = 9.2 mg, n= 90). 4.,Fruit pieces cut by majors were small (mean = 15.9 mg), approximately half the weight of leaf pieces (mean = 28.5 mg) cut and carried by media foragers. It is hypothesised that it is more difficult to cut large pieces from three-dimensional objects, like fruit, compared to two-dimensional objects, like leaves, and that majors, with their longer mandibles, can cut fruit into larger pieces than medias. 5.,The study shows both a new role for Atta majors in foraging and a new example of task partitioning in the organisation of foraging. [source]

    The size,distance relationship in the wood ant Formica rufa

    Philip J. Wright
    Summary 1. The size,distance relationship among honeydew-collecting foragers of the red wood ant Formica rufa was investigated. Within the colony territory, the size (as measured by head width) and fresh weight of samples of foragers were determined for ants ascending and descending trees near, and farther from, the central nest mound. 2. The mean size of the ants was significantly higher at far trees than at near trees in six out of the seven colonies investigated, confirming the general presence of the size,distance relationship. 3. In three colonies, a load,distance relationship was also found. For a given head width, honeydew-carrying ants descending far trees were significantly heavier than those descending near trees (i.e. they were carrying heavier loads from trees farther away from the central nest mound). 4. This is the first time that both load,distance and size,distance relationships have been reported in foraging workers from the same ant colony. 5. The combined effects of these characteristics suggest that colony foraging efficiency is enhanced by far trees being visited by the larger workers that then return with heavier loads of honeydew. [source]

    Mechanisms of behavior change in alcoholics anonymous: does Alcoholics Anonymous lead to better alcohol use outcomes by reducing depression symptoms?

    ADDICTION, Issue 4 2010
    John F. Kelly
    ABSTRACT Rationale Indices of negative affect, such as depression, have been implicated in stress-induced pathways to alcohol relapse. Empirically supported continuing care resources, such as Alcoholics Anonymous (AA), emphasize reducing negative affect to reduce relapse risk, but little research has been conducted to examine putative affective mechanisms of AA's effects. Methods Using lagged, controlled, hierarchical linear modeling and mediational analyses this study investigated whether AA participation mobilized changes in depression symptoms and whether such changes explained subsequent reductions in alcohol use. Alcohol-dependent adults (n = 1706), receiving treatment as part of a clinical trial, were assessed at intake, 3, 6, 9, 12 and 15 months. Results Findings revealed elevated levels of depression compared to the general population, which decreased during treatment and then remained stable over follow-up. Greater AA attendance was associated with better subsequent alcohol use outcomes and decreased depression. Greater depression was associated with heavier and more frequent drinking. Lagged mediation analyses revealed that the effects of AA on alcohol use was mediated partially by reductions in depression symptoms. However, this salutary effect on depression itself appeared to be explained by AA's proximal effect on reducing concurrent drinking. Conclusions AA attendance was associated both concurrently and predictively with improved alcohol outcomes. Although AA attendance was associated additionally with subsequent improvements in depression, it did not predict such improvements over and above concurrent alcohol use. AA appears to lead both to improvements in alcohol use and psychological and emotional wellbeing which, in turn, may reinforce further abstinence and recovery-related change. [source]

    Obstructive Sleep Apnea in a Clinical Series of Adult Epilepsy Patients: Frequency and Features of the Comorbidity

    EPILEPSIA, Issue 6 2003
    Raffaele Manni
    Summary: Purpose: The aim of this study was to evaluate the rate and features of obstructive sleep apnea (OSA) in adult epilepsy patients. Methods: Two hundred eighty-three adult epilepsy patients (137 men; mean age, 33 years; range, 18,70 years) were prospectively screened for OSA by means of a structured interview. Those in whom OSA was clinically suspected were monitored for a full night by using a portable device (Polymesam), and OSA was diagnosed when they had an Apnea/Hypopnea Index greater than five. Results: Coexistence of OSA with epilepsy was found in 10.2% (15.4% of the male and 5.4% of the female) epilepsy patients investigated. The OSA was mild in 66.6%, moderate in 22.2%, and severe in 11.1% of the cases. The "epilepsy + OSA" patients were older, heavier, more frequently male, and sleepier (p < 0.05) than those with "epilepsy only." Furthermore, they experienced their first seizure at an older age (p < 0.05). Conclusions: Systematic investigation reveals that OSA is frequent in epilepsy patients. The major risk factors for OSA in our epilepsy patients were the same as those typically found in the general population. Of the epilepsy-related factors, older age at onset of seizures appears to be significantly related to comorbidity with OSA (p < 0.05). The presence in epilepsy patients of these features should alert the clinician to the possibility of an underlying OSA. [source]

    Tonic regulation of satiety by 5-HT1B receptors in the mouse: converging evidence from behavioural and c- fos immunoreactivity studies?

    Michelle D. Lee
    Abstract Activation of 5-HT1B receptors is thought to play an important role in the inhibitory influence of serotonin on feeding behaviour and body weight in mammals. Earlier studies have shown that 5-HT1B -knockout (KO) mice eat more and are heavier than wild-type (WT) controls and that the selective 5-HT1B receptor agonist CP-94,253 reduces food intake in food-deprived mice. Here we characterize the behavioural effects of both CP-94,253 and the selective 5-HT1B receptor antagonist SB224289 on feeding and other behaviours within the behavioural satiety sequence, and also report a c- fos mapping study using CP-94,253. CP-94,253 produced a dose-dependent suppression of food intake with a profile consistent with a selective effect on feeding behaviour. These effects were absent or reduced in 5-HT1B -KO mice and in WT mice pretreated with SB224289. SB224289 administered alone enhanced food intake consistent with impaired satiation; a similar effect was apparent in 5-HT1B -KO mice compared to WT. CP-94,253 induced c- fos in a range of structures previously implicated in the expression of feeding behaviour. These results suggest that the activation of 5-HT1B receptors is an important component of endogenous satiation mechanisms in the mouse. [source]


    EVOLUTION, Issue 5 2000
    Hansjürg Hotz
    Abstract The European pool frog, Rana lessonae, is widely polymorphic for two common alleles (b, e) at the lactate dehydrogenase-B (LDH-B) locus. We compared fitness-related larval life-history traits among LDH-B genotypes, which originated from segregation in heterozygous parents, in an artificial pond experiment where tadpoles of R. lessonae from a Swiss population were raised together with tadpoles of the hemiclonal hybrid R. esculenta at two densities. In R. lessonae, LDH-B e/e homozygotes at each density had a higher proportion of metamorphs among survivors, reached metamorphosis earlier, and were heavier at metamorphosis than b/b homozygotes; b/e heterozygotes had intermediate values. That e/e individuals were superior to b/b in both time to and mass at metamorphosis is surprising because these two life-history traits are thought to reflect a performance trade-off; e/e genotypes apparently compensated for shorter time to metamorphosis by a higher growth rate. The two alleles showed the same performance ranking when combined in hybrids with a R. ridibunda allele: When R. esculenta from Swiss populations reared in the same ponds had received the e allele rather than the b allele from their R. lessonae parent, they reached metamorphosis earlier, but did not differ in mass at metamorphosis. The degree of linkage disequilibrium in the source population of the eight R. lessonae used as parents of the R. lessonae tadpoles is unknown, so we cannot exclude the possibility that the performance differences are caused by some anonymous tightly linked gene, rather than the LDH-B locus, that constitutes the genomically localized target of natural selection. A causal involvement of LDH-B is plausible, nevertheless, because this enzyme takes part in the central energy-metabolizing processes and has been reported to underlie fitness differences in other animals; also, differential performance of LDH-B genotypes has been observed in R. lessonae larvae from another population. The present results suggest strong directional selection for allele e; the sum of available data, including an independent laboratory experiment, suggests that partial environment-dependent overdominance combined with balancing selection favoring e/e homozygotes under some and b/b homozygotes under other conditions may be partially responsible for the broad maintenance of the LDH-B polymorphism in R. lessonae. [source]

    Survey of small-scale flame spread test results of modern fabrics

    FIRE AND MATERIALS, Issue 6 2007
    Marcelo M. Hirschler
    Abstract The flammability of apparel worn on a person has one of the highest ratios of fire fatalities per fire, and there are few statutory requirements. A series of evaluations was conducted on the flammability of 50 fabrics (both cellulosic and thermoplastic) using the (now withdrawn) NFPA 701 small-scale test. The fabrics covered a broad range of areal densities (weights) and many were not intended for apparel. A series of conclusions were reached. In particular, it is apparent that the following primary correlation exists between fabric weight and flammability: the heavier the fabric the better it behaves in a fire. Secondarily, however, the type of fabric also strongly affects this conclusion. This paper presents the results of the testing and offers an analysis. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Causes and consequences of post-growth age-dependent differences in small intestine size in a migratory sandpiper (Calidris mauri, Western Sandpiper)

    FUNCTIONAL ECOLOGY, Issue 1 2006
    R. W. STEIN
    Summary 1Calidris mauri Cabanis (Western Sandpiper) exhibits a pronounced post-growth age-dependent difference in small intestine size during southward migration, such that the later-migrating juveniles have larger small intestines than do the adults. Potential causes and consequences of this age-dependent difference are examined. 2Premigrant juveniles of full structural size had small intestines that were 10% longer than those of the premigrant adults, even though the juveniles had not attained asymptotic body mass. The elongated small intestines of premigrant juveniles appear to be growth-related. 3Adults and juveniles exhibited parallel increases in intestinal length (7·0%) and circumference (9·5%) in association with the initiation of migration; these effects are consistent with migratory hyperphagia. 4Refuelling juveniles had small intestines that were 8·5% longer than those of the refuelling adults. Retaining an enlarged small intestine during migration confers increased digestive capacity to the juveniles, which may be under selection to minimize stopover duration. 5Refuelling juveniles had a higher prevalence of cestode infection than refuelling adults in one of two years, and the length-corrected mass of the small intestine was 9·7% heavier in infected individuals. Cestode infection may be an important determinant of migration-related mortality for juveniles, by compromising their health and increasing stopover duration. [source]

    Geographical variation in the size of body organs in seabirds

    FUNCTIONAL ECOLOGY, Issue 3 2000
    G. M. Hilton
    Abstract 1.,The size of body organs shows adaptive temporal variation in many animal species. The variation in the size of body organs was examined to see if it is also a component of local adaptation to geographical variation in ecological conditions. 2.,Major body organs were measured in five species of Icelandic seabirds, sampled from two areas where birds experience slightly different ecological conditions. Between-area differences in ecological conditions were consistent among the study species, allowing tests of the generality of ecological effects on organ size. 3.,All major body organs showed geographical size variation. Livers and kidneys were larger in locations where daily energy expenditure was expected to be higher; small intestines were heavier where food was of lower energy density; stomachs were heavier where food was less digestible; heart and flight muscle were larger where flight costs were greater. 4.,It is concluded that adaptive variation in organ size may be an important means by which animals optimize exploitation of their local environment, and may be a proximate factor in intraspecific life-history and metabolic variations between geographically separate populations. [source]

    Lipid biomarker and carbon isotopic signatures for stromatolite-forming, microbial mat communities and Phormidium cultures from Yellowstone National Park

    GEOBIOLOGY, Issue 1 2004
    Linda L. Jahnke
    ABSTRACT The molecular and isotopic compositions of lipid biomarkers from cultured filamentous cyanobacteria (Phormidium, also known as Leptolyngbya) have been used to investigate the community and trophic structure of photosynthetic mats from alkaline hot springs of the Lower Geyser Basin at Yellowstone National Park. We studied a shallow-water coniform mat from Octopus Spring (OS) and a submerged, tufted mat from Fountain Paint Pots (FPP) and found that 2-methylhopanepolyols and mid-chain branched methylalkanes were diagnostic for cyanobacteria, whereas abundant wax esters were representative of the green non-sulphur bacterial population. The biomarker composition of cultured Phormidium -isolates varied, but was generally representative of the bulk mat composition. The carbon isotopic fractionation for biomass relative to dissolved inorganic carbon (DIC; ,CO2) for cultures grown with 1% CO2 ranged from 21.4 to 26.1 and was attenuated by diffusion limitation associated with filament aggregation (i.e. cell clumping). Isotopic differences between biomass and lipid biomarkers, and between lipid classes, depended on the cyanobacterial strain, but was positively correlated with overall fractionation. Acetogenic lipids (alkanes and fatty acids) were generally more depleted than isoprenoids (phytol and hopanoids). The ,13CTOC for OS and FPP mats were somewhat heavier than for cultures (,16.9 and ,23.6, respectively), which presumably reflects the lower availability of DIC in the natural environment. The isotopic dispersions among cyanobacterial biomarkers, biomass and DIC reflected those established for culture experiments. The 7-methyl- and 7,11-dimethylheptadecanes were from 9 to 11 depleted relative to the bulk organic carbon, whereas 2-methylhopanols derived from the oxidation-reduction of bacteriohopanepolyol were enriched relative to branched alkanes by approximately 5,7. These isotopic relationships survived with depth and indicated that the relatively heavy isotopic composition of the OS mat resulted from diffusion limitation. This study supports the suggestion that culture studies can establish valid isotopic relationships for interpretation of trophic structure in modern and ancient microbial ecosystems. [source]

    Equations of state for basin geofluids: algorithm review and intercomparison for brines

    GEOFLUIDS (ELECTRONIC), Issue 4 2002
    J. J. Adams
    ABSTRACT Physical properties of formation waters in sedimentary basins can vary by more than 25% for density and by one order of magnitude for viscosity. Density differences may enhance or retard flow driven by other mechanisms and can initiate buoyancy-driven flow. For a given driving force, the flow rate and injectivity depend on viscosity and permeability. Thus, variations in the density and viscosity of formation waters may have or had a significant effect on the flow pattern in a sedimentary basin, with consequences for various basin processes. Therefore, it is critical to correctly estimate water properties at formation conditions for proper representation and interpretation of present flow systems, and for numerical simulations of basin evolution, hydrocarbon migration, ore genesis, and fate of injected fluids in sedimentary basins. Algorithms published over the years to calculate water density and viscosity as a function of temperature, pressure and salinity are based on empirical fitting of laboratory-measured properties of predominantly NaCl solutions, but also field brines. A review and comparison of various algorithms are presented here, both in terms of applicability range and estimates of density and viscosity. The paucity of measured formation-water properties at in situ conditions hinders a definitive conclusion regarding the validity of any of these algorithms. However, the comparison indicates the versatility of the various algorithms in various ranges of conditions found in sedimentary basins. The applicability of these algorithms to the density of formation waters in the Alberta Basin is also examined using a high-quality database of 4854 water analyses. Consideration is also given to the percentage of cations that are heavier than Na in the waters. [source]

    Nonalcoholic fatty pancreas disease

    HPB, Issue 4 2007
    Abhishek Mathur
    Abstract Background. Obesity leads to fat infiltration of multiple organs including the heart, kidneys, and liver. Under conditions of oxidative stress, fat-derived cytokines are released locally and result in an inflammatory process and organ dysfunction. In the liver, fat infiltration has been termed nonalcoholic fatty liver disease, which may lead to nonalcoholic steatohepatitis. No data are available, however, on the influence of obesity on pancreatic fat and cytokines, and nonalcoholic fatty pancreas disease (NAFPD) has not been described. Therefore, we designed a study to determine whether obesity is associated with increased pancreatic fat and cytokines. Materials and methods. Thirty C57BL/6J lean control and 30 leptin-deficient obese female mice were fed a 15% fat diet for 4 weeks. At 12 weeks of age all animals underwent total pancreatectomy. Pancreata from each strain were pooled for measurement of a) wet and dry weight, b) histologic presence of fat, c) triglycerides, free fatty acids (FFAs), cholesterol, phospholipids, and total fat, and d) interleukin (IL)-1, and tumor necrosis factor-alpha (TNF-,). Data were analyzed by Student's t test and Fisher's exact test. Results. Pancreata from obese mice were heavier (p<0.05) and had more fat histologically (p<0.05). Pancreata from obese mice had more triglycerides, FFAs, cholesterol, and total fat (p<0.05). Triglycerides represented 11% of pancreatic fat in lean mice compared with 67% of pancreatic fat in obese mice (p<0.01). Cytokines IL-1, and TNF-, also were elevated in the pancreata of obese mice (p<0.05). Conclusions. These data suggest that obese mice have 1) heavier pancreata, 2) more pancreatic fat, especially triglycerides and FFAs, and 3) increased cytokines. We conclude that obesity leads to nonalcoholic fatty pancreatic disease. [source]

    Dispersal and migration of juvenile African Black Oystercatchers Haematopus moquini

    IBIS, Issue 3 2003
    Philip A. R. Hockey
    African Black Oystercatchers Haematopus moquini are sedentary as adults. However, colour-ringing of more than 700 juveniles has revealed complex post-fledging movements that vary geographically. Young from the western part of the breeding range either remain within 150 km of their natal site or migrate 1500,2000 km to one of five discrete nursery areas on the Namib Desert coast of central and northern Namibia, and southern Angola. These nurseries all lie north of the species' breeding range. We calculate that 36,46% of all juveniles born in South Africa migrate to nurseries. Birds return to their natal sites from nurseries at 2,3 years old, but never migrate again. Juveniles from the eastern part of the range undertake ,diffusion dispersal', regularly up to 1000 km, but these journeys mostly end within the breeding range, where there are no nurseries. Very few eastern birds reach nurseries. There is no evidence that movements of western birds are density-dependent responses to hatching date, but long-distance migrants are significantly heavier as chicks than are short-distance dispersers. We hypothesize that a genetic basis exists to these movements, possibly triggered by body condition, that could account not only for the highly dichotomous behaviour of western birds, but also for the intermediate behaviour of eastern birds. [source]

    Sex, diet and feeding method-related differences in body condition in the Oystercatcher Haematopus ostralegus

    IBIS, Issue 1 2001
    SARAH E.A.
    Measurements were made of Oystercatcher corpses to find the most reliable measure of body condition in live birds. Total body weight was as accurate as muscle thickness in assessing the weight of the pectoral muscles, a major store of protein reserves. Total body weight was also a good indicator of fat reserves. Wing-length was the most reliable measure of body size. Body condition in live birds was measured as an individual's residual weight derived from a general linear model of (loge) body weight against age, month, (loge) wing-length and time since capture. On the Exe estuary in autumn, there was no significant difference in body condition between same-age Oystercatchers of different diets and feeding methods. In the winter months, however, body condition differed significantly between mussel feeders using different feeding methods, and between mussel feeders and birds that fed on worms and clams. Differences between diet/feeding methods were not the same for each age group. Birds with the highest mean body condition index in adults were mussel hammerers, in immatures mussel stabbers and in juveniles, worm/clam feeders. No significant difference in body condition was found between the sexes in any age group in autumn. In winter, when birds with the same diet/feeding method were considered, females were significantly heavier than males. However, when birds of all diets and feeding methods were combined, weight differences between the sexes were not apparent. We examine reasons why birds with certain diets and feeding methods may be heavier than others in winter, and why females are sometimes heavier than males. We conclude that, in most cases, it is due to differences between birds in their ability to achieve a common target weight. However, we conclude that adult females try to achieve a higher target weight than males, probably as a premigratory and prebreeding strategy. In the light of this, we consider the consequences for adult females, in terms of reproductive success and survival, of specializing in diets and feeding methods associated with lower body weights in winter. [source]

    Instabilities during batch sedimentation in geometries containing obstacles: A numerical and experimental study,

    Rekha R. Rao
    Abstract Batch sedimentation of non-colloidal particle suspensions is studied with nuclear magnetic resonance flow visualization and continuum-level numerical modelling of particle migration. The experimental method gives particle volume fraction as a function of time and position, which then provides validation data for the numerical model. A finite element method is used to discretize the equations of motion, including an evolution equation for the particle volume fraction and a generalized Newtonian viscosity dependent on local particle concentration. The diffusive-flux equation is based on the Phillips model (Phys. Fluids A 1992; 4:30,40) and includes sedimentation terms described by Zhang and Acrivos (Int. J. Multiphase Flow 1994; 20:579,591). The model and experiments are utilized in three distinct geometries with particles that are heavier and lighter than the suspending fluid, depending on the experiment: (1) sedimentation in a cylinder with a contraction; (2) particle flotation in a horizontal cylinder with a horizontal rod; and (3) flotation around a rectangular inclusion. Secondary flows appear in both the experiments and the simulations when a region of higher density fluid is above a lower density fluid. The secondary flows result in particle inhomogeneities, Rayleigh,Taylor-like instabilities, and remixing, though the effect in the simulations is more pronounced than in the experiments. Published in 2007 by John Wiley & Sons, Ltd. [source]

    Patterns of weight change after treatment for bulimia nervosa

    Frances A. Carter
    Abstract Objective The current study examined changes in weight and body mass index (BMI) at 5-year follow-up among women treated for bulimia nervosa. Method The study comprised 80 women who had participated in a randomized clinical trial evaluating cognitive-behavior therapy for bulimia nervosa. The women had attended assessments at posttreatment and at 5-year follow-up while not pregnant. Results Changes in mean weight and BMI between posttreatment and 5-year follow-up were small in absolute terms and were not statistically significant. However, by the 5-year follow-up, approximately one half of the participants had either lost (31%) or gained (18%) 5 or more kilograms or were underweight (31%) or overweight (24%) as defined by BMI. Univariate analyses suggest that it is the patients who gain weight over the follow-up that are distinctive. Patients who gained weight over the follow-up were more likely to have commenced menstruation at a younger age, to have a lifetime history of being heavier, and to have been heavier and more dissatisfied with their body at pretreatment, posttreatment, and at 5-year follow-up. Conclusion Five years after treatment for bulimia nervosa, approximately one half of the participants had changed substantially in weight. For those who had changed, weight loss was more common than weight gain. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 36: 12,21, 2004. [source]

    Tufa Deposition in Karst Streams Can Enhance the Food Supply of the Grazing Caddisfly Melampophylax mucoreus (Limnephilidae)

    Christian Kock
    Abstract We studied the effect of carbonate depositions covering stone surfaces on the growth of larvae and the biomass of subsequent adults of the grazing limnephilid caddisfly Melampophylax mucoreus(Hagen, 1861) in a laboratory rearing experiment. M. mucoreus is mainly distributed in karst streams characterized by calcium carbonate precipitations (tufa). We reared larvae of M. mucoreus on stones covered by calcareous tufa crusts as well as on stones from which these crusts were experimentally removed to assess the influence on larval growth and the subsequent adult biomass. The rough surface of the covered stones provided a higher complexity of micro-habitats and supported algal growth compared to the smooth surface of stones without crusts. Larvae of M. mucoreus profited from the enhanced algal biofilm growth on the calcium carbonate precipitation indicated by faster larval growth and higher subsequent adult biomass. Biomass increase of larvae reared on stones covered by tufa crusts exhibited a faster biomass development (0.09 ± 0.015 mg/d) compared to the larvae reared on stones without crusts (0.06 ± 0.002 mg/d). Adult males (5.13 ± 0.25 mg) and females (7.64 ± 0.63 mg) were significantly heavier in the treatment with stones covered by tufa than their conspecifics from the treatment with uncovered stones (males: 4.26 ± 0.25 mg, p = 0.047; females: 4.96 ± 0.47 mg, p = 0.001). Additionally, males from the treatment with crust covered stones emerged significantly earlier (p = 0.003) than the males from the other treatment, whereas no significant difference was found for females. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Forces and Relations of Production in Early Medieval England

    The economy of post-Roman Britain entered a phase of abatement in which pastoralism played an important part. Common pasture and access to it underlay small regions within which the form of dominance practised by an emerging elite was neither antique nor feudal but akin to that of chieftains over clans. The mid-Saxon emphasis on arable farming, which demanded heavier and more concentrated inputs of labour and capital, led to a more direct appropriation of peasant surplus and labour, the basis of the feudal mode of production. [source]

    Topographical and laminar distribution of cortical input to the monkey entorhinal cortex

    JOURNAL OF ANATOMY, Issue 2 2007
    A. Mohedano-Moriano
    Abstract Hippocampal formation plays a prominent role in episodic memory formation and consolidation. It is likely that episodic memory representations are constructed from cortical information that is mostly funnelled through the entorhinal cortex to the hippocampus. The entorhinal cortex returns processed information to the neocortex. Retrograde tracing studies have shown that neocortical afferents to the entorhinal cortex originate almost exclusively in polymodal association cortical areas. However, the use of retrograde studies does not address the question of the laminar and topographical distribution of cortical projections within the entorhinal cortex. We examined material from 60 Macaca fascicularis monkeys in which cortical deposits of either 3H-amino acids or biotinylated dextran-amine as anterograde tracers were made into different cortical areas (the frontal, cingulate, temporal and parietal cortices). The various cortical inputs to the entorhinal cortex present a heterogeneous topographical distribution. Some projections terminate throughout the entorhinal cortex (afferents from medial area 13 and posterior parahippocampal cortex), while others have more limited termination, with emphasis either rostrally (lateral orbitofrontal cortex, agranular insular cortex, anterior cingulate cortex, perirhinal cortex, unimodal visual association cortex), intermediate (upper bank of the superior temporal sulcus, unimodal auditory association cortex) or caudally (parietal and retrosplenial cortices). Many of these inputs overlap, particularly within the rostrolateral portion of the entorhinal cortex. Some projections were directed mainly to superficial layers (I,III) while others were heavier to deep layers (V,VI) although areas of dense projections typically spanned all layers. A primary report will provide a detailed analysis of the regional and laminar organization of these projections. Here we provide a general overview of these projections in relation to the known neuroanatomy of the entorhinal cortex. [source]

    Relation between Holstein bulls' proofs for milk in USA and the survival and body weights up to 18 months of their F1 zebu progeny in Venezuela

    J. R. Pacheco
    Summary The purpose of the study was to determine the relation between Holstein bulls' proofs for milk in USA, and the survival and body weights of their F1 progeny under lowland grazing conditions in Venezuela. Semen was selected from sires with the highest proofs available locally (class H, n = 23) or with proofs close to the breed average (class A, n = 18). Mean proofs were 934 kg (H) and 237 kg (A), respectively, when semen was purchased (1989,93), falling to 204 and ,386 kg when updated in 2001. Dams were Brahman-type zebus on seven farms, raising the F1 progeny (n = 866) on native or cultivated pasture with only mineral supplements. Records of survival to 8 and 18 months and weights at birth, 8 and 18 months of age were analysed using linear models. Sire class had no effect on survival or weight at birth, but H progeny were slightly heavier than A progeny at 8 (4.0%, p = 0.06) and 18 months (2.6%, p < 0.05). The interaction class × farm was only significant for survival, with H progeny equal or superior to A groups on six farms. The effect of sire within class was highly significant for survival to 8 months and weight at 18 months. Rank correlations using sires' milk proofs and F1 progeny weights and survival were not significant. It was concluded that the use of Holstein bulls with high milk proofs may lead to slightly higher 18-month weights in their F1 progeny in tropical grazing systems, covering the additional cost of H semen, but that sire evaluation for weight gain and progeny survival rates may be justified under these conditions. Zusammenfassung Beziehungen zwischen den Zuchtwerten für Milch von Holstein-Bullen in den USA und dem Überleben und dem Körpergewicht bis zu 18 Monaten ihrer F1-Zebu-Nachkommen in Venezuela Der Zweck dieser Studie war die Ermittlung der Beziehungen zwischen den Milch-Zuchtwerten von Holstein-Bullen in den USA und dem Überleben und dem Körpergewicht von F1-Nachkommen unter den Weidebedingungen des Flachlandes in Venezuela. Ausgewählt wurde das Sperma von lokal verfügbaren Bullen mit den höchsten Zuchtwerten (Klasse H, n = 23) oder mit Zuchtwerten, die eng am Populationsdurchschnitt (Klasse A, n = 18) lagen. Beim Erwerb des Spermas (1989,1993) betrugen die mittleren Zuchtwerte 934 kg (H) beziehungsweise 237 kg (A), die bei der Neubewertung 2001 auf 204 kg und ,386 kg abfielen. Die Kühe waren Zebus im Brahman-Typ von sieben Farmen, die die F1-Nachkommen (n = 866) auf natürlichen oder kultivierten Weiden nur mit zusätzlichem Mineralfutter aufzogen. Das Überleben mit acht und 18 Monaten und das Gewicht bei der Geburt, mit acht und mit 18 Monaten wurde mittels linearer Modelle analysiert. Die Bullenklasse zeigte keinen Effekt auf das Überleben und das Geburtsgewicht, aber die H-Nachkommen waren mit acht (4%, p = 0,06) und 18 Monaten (2,6%, p < 0,05) etwas schwerer als die A-Nachkommen. Die Interaktion "Klasse × Farm" war nur für das Überleben signifikant, mit H-Nachkommen gleich oder besser als die A-Gruppen auf sechs Farmen. Der Effekt des Vaters innerhalb der Klasse war hochsignifikant für das Überleben der ersten acht Monate und das Gewicht mit 18 Monaten. Rang-Korrelationen mit den Milch-Zuchtwerten der Bullen und den Gewichten und dem Überleben der F1-Nachkommen waren nicht signifikant. Die Verwendung von Holstein-Bullen mit hohen Zuchtwerten für Milch kann zu einer leichten Erhöhung des Gewicht der F1-Nachkommen mit 18 Monaten in tropischen Weidesystemen führen, welche die zusätzlichen Kosten des H-Spermas abdeckt, aber die Bewertung der Bullen hinsichtlich Gewichtszunahme und Überlebensrate der Nachkommen müsste unter diesen Bedingungen berichtigt werden. [source]

    Feedback effects of chronic browsing on life-history traits of a large herbivore

    M. Anouk Simard
    Summary 1Increasing ungulate populations are affecting vegetation negatively in many areas, but few studies have assessed the long-term effects of overbrowsing on individual life-history traits of ungulates. 2Using an insular population of white-tailed deer (Odocoileus virginianus Zimmermann; Anticosti, Québec, Canada) introduced in 1896, and whose density has remained high since the first evidence of severe browsing in the 1930s, we investigated potential feedbacks of long-term and heavy browsing on deer life-history traits. 3We assessed whether chronic browsing contributed to a decline of the quality of deer diet in early autumn during the last 25 years, and evaluated the impacts of reduced diet quality on deer body condition and reproduction. 4Rumen nitrogen content declined 22% between two time periods, 1977,79 and 2002,04, indicating a reduction in diet quality. 5After accounting for the effects of year within the time period, age and date of harvest in autumn, peak body mass of both sexes declined between the two time periods. At the end of November, males were on average 12% heavier and adult does 6% heavier in 1977,79 than in 2002,04. Hind foot length did not vary between time periods. 6The probability of conception increased 15% between the two time periods, but litter size at ovulation declined 7%, resulting in a similar total number of ovulations in 2002,04 and in 1977,79. 7Our results suggest that following a decline in diet quality, white-tailed deer females modified their life-history strategies to maintain reproduction at the expense of growth. 8Deer appear to tolerate drastic reductions in diet quality by modifying their life history traits, such as body mass and reproduction, before a reduction in density is observed. Such modifications may contribute to maintain high population density of large herbivores following population irruption. [source]

    Sex-related effects of maternal egg investment on offspring in relation to carotenoid availability in the great tit

    Anne Berthouly
    Summary 1Maternal carotenoids in the egg yolk have been hypothesized to promote maturation of the immune system and protect against free radical damages. Depending on availability, mothers may thus influence offspring quality by depositing variable amounts of carotenoids into the eggs. Sex allocation theory predicts that in good quality environments, females should invest into offspring of the sex that will provide larger fitness return, generally males. 2In a field experiment we tested whether female great tits bias their investment towards males when carotenoid availability is increased, and whether male offspring of carotenoid-supplemented mothers show higher body condition. We partially cross-fostered hatchlings to disentangle maternal effects from post-hatching effects, and manipulated hen flea Ceratophyllus gallinae infestation to investigate the relationship between carotenoid availability and resistance to ectoparasites. 3As predicted, we found that carotenoid-supplemented mothers produced males that were heavier than their sisters at hatching, while the reverse was true for control mothers. This suggests that carotenoid availability during egg production affects male and female hatchlings differentially, possibly via a differential allocation to male and female eggs. 4A main effect of maternal supplementation became visible 14 days after hatching when nestlings hatched from eggs laid by carotenoid-supplemented mothers had gained significantly more mass than control nestlings. Independently of the carotenoid treatment, fleas impaired mass gain of nestlings during the first 9 days in large broods only and reduced tarsus length of male nestlings at an age of 14 days, suggesting a cost to mount a defence against parasites. 5Overall, our results suggest that pre-laying availability of carotenoids affects nestling condition in a sex-specific way with potentially longer-lasting effects on offspring fitness. [source]

    Influence of maternal mass and condition on energy transfer in Weddell seals

    Summary 1Environmental variation influences food abundance and availability, which is reflected in the reproductive success of top predators. We examined maternal expenditure, offspring mass and condition for Weddell seals in 2 years when individuals exhibited marked differences in these traits. 2For females weighing 355 kg there was a positive relationship between maternal post-partum mass (MPPM) and lactation length, but below this there was no relationship, suggesting that heavier females were able to increase lactation length but lighter females were restricted to a minimum lactation period of 33 days. 3Overall, females were heavier in 2002, but in 2003 shorter females were lighter than similar-sized females in 2002 suggesting that the effects of environmental variability on foraging success and condition are more pronounced in smaller individuals. 4There was no relationship between MPPM and pup birth mass, indicating pre-partum investment did not differ between years. However, there was a positive relationship between MPPM and pup mass gain. Mass and energy transfer efficiency were 10·2 and 5·4% higher in 2002 than 2003, which suggests costs associated with a putatively poor-resource year were delayed until lactation. 5Heavier females lost a higher proportion of mass during lactation in both years, so smaller females may not have been able to provide more to their offspring to wean a pup of similar size to larger females. 6MPPM had only a small influence on total body lipid; therefore, regardless of mass, females had the same relative body composition. Females with male pups lost a higher percentage of lipid than those with female pups, but by the end of lactation female pups had 4·5% higher lipid content than males. 7It appears that for Weddell seals the consequences of environmentally induced variation in food availability are manifested in differences in maternal mass and expenditure during lactation. These differences translate to changes in pup mass and condition at weaning with potential consequences for future survival and recruitment. [source]

    Maternal yolk testosterone does not modulate parasite susceptibility or immune function in great tit nestlings

    Summary 1Maternal yolk hormones can enhance the development and phenotypic quality of nestling birds. Nevertheless, within species large differences in yolk androgen concentrations among clutches are observed. This differential allocation of maternal yolk hormones might be explained by a trade-off between beneficial effects of yolk androgens and their associated costs. 2Potential costs include an increased susceptibility to parasites in nestlings exposed to high concentrations of yolk androgens during embryonic development, weaker immune response or increased levels of circulating corticosterone that indirectly reduce immune function. 3In a field study, we manipulated yolk testosterone in great tit (Parus major) eggs and tested the nestling's susceptibility to ectoparasites as measured by the parasites' effect on growth, the cellular immune response, and the levels of circulating corticosterone. 4At the end of the nestling period, nestlings originating from testosterone-injected eggs were heavier than control nestlings. This effect was strongest in nestlings at the end of the size hierarchy, as shown by a significant interaction between hormone treatment and the nestlings' size rank within nests. 5High levels of yolk testosterone promoted growth of the nestling's body mass similarly in parasite-infested and parasite-free nests, and neither affected the levels of plasma corticosterone, nor the nestling's cell-mediated immune response. 6In summary, our results do not show negative short-term effects of high concentrations of yolk testosterone on immune function or parasite susceptibility, but emphasize that maternal investment via deposition of yolk testosterone can promote fitness-related growth and development of nestlings. [source]

    Comparative study on the consequences of culling badgers (Meles meles) on biometrics, population dynamics and movement

    F. A. M. Tuyttens
    1.,Capture,mark,recapture data were used to describe the process of recovery from a typical badger removal operation (BRO) at North Nibley, Gloucestershire, UK, which was carried out as part of the government's strategy to control bovine tuberculosis. Data on biometrics, demographics and movement from this low-density disturbed population were compared with those of two nearby high-density undisturbed populations (Wytham Woods and Woodchester Park, UK) in order to study fundamental principles of population dynamics and density-dependence. 2.,Badgers moved more between social groups at North Nibley than in the other study areas, particularly in the immediate aftermath of the removal operation. 3.,Recolonization of the vacated habitat occurred in the first instance by young females. 4.,Although in the first year after the BRO no cubs had been reared in any of the culled groups, and although the shortage of sexually mature boars may have limited the reproductive output of sows in the following year, the population took only 3 years to recover to its (already lowered) preremoval density. 5.,Losses from the adult (and cub) population due to mortality or emigration were smaller at North Nibley than at the other sites. 6.,There was much evidence that during 1995 and 1996 density-dependent effects constrained the reproductive output of the high-density populations, and some support for the hypothesis that badgers exhibit the non-linear ,large mammal' type of functional response to density. 7.,Badgers at North Nibley were younger, heavier and in better condition than badgers at Wytham Woods and Woodchester Park. 8.,We argue that the disease dynamics are likely to be different in disturbed compared with undisturbed badger populations, and that this could affect the effectiveness of BROs. [source]

    Reproductive biology of the skate, Rioraja agassizii (Müller and Henle, 1841), off Puerto Quequén, Argentina

    M. Estalles
    Summary A total of 230 specimens of the skate, Rioraja agassizii, was collected from the commercial bottom trawl fishery of Puerto Quequén, Argentina. During the warmer seasons greater proportions of females were sampled. The largest male and female sampled were 629 and 698 mm total length (TL), respectively. Sexual dimorphism was detected in the relationship between weight (W),TL and disc width (DW),TL, in that females were heavier and wider than males. The smallest mature male and female were 485 and 530 mm TL, respectively. TL at 50% maturity (TL50%) was estimated at 504 and 570 mm for males and females, respectively. Females exhibited heavier livers than males throughout their lifetimes. Seasonal variations in the gonadosomatic (GSI) and hepatosomatic (HSI) indices, and in the width of the left oviducal gland (OG), along with the greater number of pregnant females sampled during spring, suggested that the peak of the egg laying season could be during this season. The egg cases presented a mean length of 69.01 ± 5.53 mm, mean width of 43.40 ± 1.86 mm and mean weight of 17.00 ± 4.59 g. According to these results specimens from Puerto Quequén and southern Brazil appeared to differ in size, the peak of the egg-laying season and in egg dimensions. [source]

    When and where to fuel before crossing the Sahara desert , extended stopover and migratory fuelling in first-year garden warblers Sylvia borin

    Thord Fransson
    Large numbers of passerine migrants cross the Sahara desert every year on their way to-and-from wintering areas in tropical Africa. In the desert, hardly any fuelling opportunities exist and most migrants have to prepare in advance. A central question is how inexperienced birds know where to fuel. Inexperienced garden warblers Sylvia borin were studied in Greece just before the desert crossing in autumn. Body mass data collected at two sites indicate that most birds do not fuel for the desert crossing further north. For the first time, detailed information about stopover duration close to the Sahara desert was studied by using light weight radio-transmitters. Results from Crete show that most first-year garden warblers arrive with relatively small fuel loads in relation to lean body mass (<30%), stay for 13,20 d and depart with an average fuel load of about 100%. Radio-tagged birds performed small scale movements initially and took advantage of fig fruits. Birds trapped at fig trees were heavier than birds trapped with tape lures, showing that tape lures can bias the sample of migrants trapped. The precise fuelling pattern found indicates that first-year migrants must also include external spatial cues to make the preparation for crossing the desert in the right area. [source]