Increasing Proportion (increasing + proportion)

Distribution by Scientific Domains

Selected Abstracts

How to design perforated polymeric films for modified atmosphere packs (MAP)

Luciano ZanderighiArticle first published online: 12 APR 200
Abstract Increasing proportions of fresh produce are being sold in modified atmosphere packs (MAP) with the aim of preserving product quality longer and reducing freight costs. A rigorous theoretical analysis was made of the transport phenomena across packaging film (composite, perforated, etc.) in order to find out whether polymeric film will permit a stationary modified atmosphere (MA) inside the pack, and if so when, and to investigate the effect of the size and shape of the holes in the perforated film. The continuity equations of the pack, for all diffusing species, were written and solved for stationary conditions, with the boundary conditions that species not involved in metabolic processes do not diffuse across polymeric film. After a detailed analysis of the transport phenomena across both continuous and perforated film, and of the metabolic rate processes, it transpires that no stationary conditions compatible with any MA can be found for continuous film, owing to the permeation characteristics of the film and the rate of the metabolic processes. With perforated film it is possible to find, at least for certain metabolic process rates, a stationary state where a constant MA is maintained inside the pack. A proposal is given, provided the rate of the metabolic process is known, for the design of a pack in terms of polymeric materials and of the pinhole size. Two case studies, strawberry and cabbage, are presented and discussed, along with the optimization of the polymeric film and the size and length of the pinholes of the packs. Another point raised deals with the advantages of using perforated film and/or of making holes or openings along the edges where the polymeric film is welded. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Life expectancy among people with cerebral palsy in Western Australia

E Blair PhD
This report describes trends, predictors, and causes of mortality in persons with cerebral palsy (CP)using individuals identified by the Western Australian Cerebral Palsy Register and born between 1958 and 1994. Two thousand and fourteen people were identified (1154 males, 860 females), of whom 225 had died by 1 June 1997. Using date-of-death data, crude and standardized mortality rates were estimated and predictors of mortality sought using survival analysis stratified by decade of birth, description of impairments, and demographic and perinatal variables. For those born after 1967, the cause of death profile was examined over time. Mortality exceeded 1% per annum in the first 5 years and declined to age 15 years after which it remained steady at about 0.35% for the next 20 years. The strongest single predictor was intellectual disability, but all forms of disability contributed to decreased life expectancy. Half of those with IQ/DQ score <20 survived to adulthood, increasing to 76% with IQ/DQ score 20,34, and exceeding 92% for higher scores. Severe motor impairment primarily increased the risk of early mortality. Despite there being 72 persons aged from 25 to 41 years with severe motor impairment in our data set, none had died after the age of 25 years. Infants born after more than 32 weeks'gestation were at significantly higher risk of mortality than very preterm infants, accounted for by their higher rates of intellectual disability. No improvements in survival of persons with CP were seen over the study period despite advances in medical care, improved community awareness, and the increasing proportion of very preterm births among people with CP. This may be the result of improved neonatal care enabling the survival of infants with increasingly severe disabilities. [source]

Outcome of long-term heroin-assisted treatment offered to chronic, treatment-resistant heroin addicts in the Netherlands

ADDICTION, Issue 2 2010
Peter Blanken
ABSTRACT Aims To describe 4-year treatment retention and treatment response among chronic, treatment-resistant heroin-dependent patients offered long-term heroin-assisted treatment (HAT) in the Netherlands. Design Observational cohort study. Setting and intervention Out-patient treatment in specialized heroin treatment centres in six cities in the Netherlands, with methadone plus injectable or inhalable heroin offered 7 days per week, three times per day. Prescription of methadone plus heroin was supplemented with individually tailored psychosocial and medical support. Participants Heroin-dependent patients who had responded positively to HAT in two randomized controlled trials and were eligible for long-term heroin-assisted treatment (n = 149). Measurements Primary outcome measures were treatment retention after 4 years and treatment response on a dichotomous, multi-domain response index, comprising physical, mental and social health and illicit substance use. Findings Four-year retention was 55.7% [95% confidence interval (CI): 47.6,63.8%]. Treatment Response was significantly better for patients continuing 4 years of HAT compared to patients who discontinued treatment: 90.4% versus 21.2% [difference 69.2%; odds ratio (OR) = 48.4, 95% CI: 17.6,159.1]. Continued HAT treatment was also associated with an increasing proportion of patients without health problems and who had stopped illicit drug and excessive alcohol use: from 12% after the first year to 25% after 4 years of HAT. Conclusions Long-term HAT is an effective treatment for chronic heroin addicts who have failed to benefit from methadone maintenance treatment. Four years of HAT is associated with stable physical, mental and social health and with absence of illicit heroin use and substantial reductions in cocaine use. HAT should be continued as long as there is no compelling reason to stop treatment. [source]

Subcellular cadmium distribution, accumulation, and toxicity in a predatory gastropod, Thais clavigera, fed different prey

Ma-Shan Cheung
Abstract Bioaccumulation and toxicity of Cd were investigated in a marine predatory whelk, Thais clavigera, after being fed with the rock oyster, Saccostrea cucullata, or the herbivorous snail, Monodonta labio, for up to four weeks. The oysters and snails had different subcellular Cd distributions and concentrations in their bodies given their different metal-handling strategies and were exposed to dissolved Cd for two weeks before being fed to the whelks. After four weeks of dietary exposure, the Cd body concentrations in T. clavigera increased from 3.1 ,g/g to between 22.9 and 41.8 ,g/g and to between 22.7 and 24.1 ,g/g when they were fed with oyster and snail prey, respectively. An increasing proportion of Cd was found to be distributed in the metallothionein (MT)-like proteins and organelle fractions, whereas the relative distribution in the metal-rich granules fraction decreased when the whelks were fed Cd-exposed prey. At the highest Cd dosage, more Cd was distributed in the pool of metal-rich granules when the whelks were fed the oysters than when they were fed the snails. Among all the biomarkers measured (MT induction, condition index, lipid peroxidation, and total energy reserve including carbohydrate, lipid, and protein), only MT showed a significant difference from the control treatments, and MT was the most sensitive biomarker for dietary Cd exposure. No toxicity was found in the whelks fed different Cd-exposed prey as revealed by various biomarkers at the different biological levels. Our results imply that metal fractionation in prey can alter the subsequent subcellular metal distribution in predators and that dietary Cd toxicity to the whelks was low, even when the accumulated Cd body concentrations were high. [source]

Undergraduate teaching in gerodontology in Austria, Switzerland and Germany

Ina Nitschke
Objective:, To survey the present state of undergraduate teaching in the domain of gerodontology in Germany, Switzerland and Austria. Study participants:, All universities of Austria (A), Germany (D) and Switzerland (CH). Protocol:, A questionnaire on undergraduate teaching in gerodontology was mailed to all Deans (A: n = 3; CH: n = 4; D: n = 31) and all independent departments except paediatric dentistry and orthodontics (A: n = 11; CH: n = 15; D: n = 111). Results:, The questionnaires were completed and returned by 29 Deans (A: n = 2; CH: n = 4; D: n = 23) and 102 departments (A: n = 7; CH: n = 8; D: n = 87). In Austria, gerodontology is a very small component of the dental curriculum and the Deans did not want this to be increased. Most German universities claimed to teach some aspects of gerodontology to undergraduate students and 87.4% of the Deans voted for separate lectures in gerodontology. In Switzerland, gerodontology seems well established. The results of questionnaires from the independent departments revealed that in all three countries lectures were more prevalent (A: n = 0; CH: n = 4; D: n = 6) than practical training in nursing homes (A: n = 0; CH: n = 3; D: n = 6). Conclusion:, Considering the demographical shift which is leading to an increasing proportion of elderly in the population, the weighting of gerodontology in the undergraduate dental curriculum should be considered for revision in Austria and Germany. [source]

Measuring the effect of husband's health on wife's labor supply

Michele J. SiegelArticle first published online: 31 JAN 200
Abstract A sizable proportion of women remain married well into late life and an increasing proportion of them participate in the labor force. Since women tend to marry men older than themselves and men tend to experience serious illnesses at younger ages than women, women frequently witness declining health in their husbands. This is likely to affect a wife's labor,leisure trade-off in offsetting ways. Prior studies have not sought to disentangle the effect of a husband's poor health on his wife's reservation wage from the income effect of his ill health. We argue that, if we control for husband's earnings, the coefficient of husband's health in models of his wife's labor force participation (and hours of work) will reflect, in part, her preference over whether to decrease her labor supply to provide health care for her husband or whether to instead increase it to purchase this care in the market. However, husband's earnings are likely to be endogenous in these models due to unobserved characteristics common to husbands and wives. We find that the estimated effect of husband's health depends on whether we instrument for husband's earnings and on the health measure used. This is indicative of the importance of using a variety of health measures and controlling for husband's earnings, and their endogeneity, in future research on the effect of husband's health on wife's labor supply. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Causes of the first AIDS-defining illness and subsequent survival before and after the advent of combined antiretroviral therapy,

HIV MEDICINE, Issue 4 2008
S Grabar
Objectives To analyse the impact of combined antiretroviral treatment (cART) on survival with AIDS, according to the nature of the first AIDS-defining clinical illness (ADI); to examine trends in AIDS-defining causes (ADC) and non-AIDS-defining causes (non-ADC) of death. Methods From the French Hospital Database on HIV, we studied trends in the nature of the first ADI and subsequent survival in France during three calendar periods: the pre-cART period (1993,1995; 8027 patients), the early cART period (1998,2000; 3504 patients) and the late cART period (2001,2003; 2936 patients). Results The three most frequent initial ADIs were Pneumocystis carinii (jirovecii) pneumonia (PCP) (15.6%), oesophageal candidiasis (14.3%) and Kaposi's sarcoma (13.9%) in the pre-cART period. In the late cART period, the most frequent ADIs were tuberculosis (22.7%), PCP (19.1%) and oesophageal candidiasis (16.2%). The risk of death after a first ADI fell significantly after the arrival of cART. Lower declines were observed for progressive multifocal leukoencephalopathy, lymphoma and Mycobacterium avium complex infection. After an ADI, the 3-year risk of death from an ADC fell fivefold between the pre-cART and late cART periods (39%vs. 8%), and fell twofold for non-ADCs (17%vs. 9%). Conclusions The relative frequencies of initial ADI have changed since the advent of cART. Tuberculosis is now the most frequent initial ADI in France; this is probably the result of the increasing proportion of migrants from sub-Saharan Africa. After a first ADI, cART has a major impact on ADCs and a smaller impact on deaths from other causes. The risk of death from AIDS and from other causes is now similar. [source]

A review of the suspended sediment budget at the confluence of the Paraná and Paraguay Rivers

Mario L. Amsler
Abstract In this paper, the sediment budget at the confluence of the Paraná,Paraguay Rivers is updated on the basis of new suspended sediment concentration data, obtained during the 1990s at carefully located cross-sections, after the construction of several large reservoirs. With these data, it was possible to estimate that the suspended sediment load transported by the Upper Paraná River had decreased by 60% due to the influence of the dams. This decrease occurred in spite of the influence of climate change across the Upper Paraná and Paraguay basin, which increased the precipitation and surface runoff. As a consequence of these anthropogenic and natural processes, the Bermejo River (the main source of wash load to the system) accounts for an increasing proportion of the sediment transport along the middle and lower reaches of the Paraná River. The Paraná River currently transports about 120 × 106 t year,1 of wash load, with nearly 90% of this being supplied by the Bermejo. The contribution from the Bermejo is now about 35% larger than its contribution during the 1970s, when it accounted for approximately 60% of the sediment load of the Paraná River. These changes that have occurred over the last 30 years have enhanced the natural asymmetrical distribution of solid and water discharges in the Paraná River basin. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Assessment, intervention, and research with infants in out-of-home placement

Robert B. Clyman
Infants constitute a large and increasing proportion of youth in out-of-home placement. These infants have very high rates of medical illnesses, developmental delays, and substantial risks for psychopathology. They receive varying amounts of services from a complex and poorly integrated service system that includes four principal service sectors: the child welfare, medical, early intervention, and mental health service sectors. These service systems are currently undergoing major changes in their policies, organization, and financing, such as the introduction of managed care into the child welfare system. In this article, we provide an overview of what is known about infants in out-of-home placement. We then summarize approaches to infant mental health assessment and intervention from a comprehensive perspective that addresses the infants' multiple problems and acknowledges that they need to receive services from multiple systems that are undergoing rapid change. We conclude by highlighting a number of critical areas in need of research. ©2002 Michigan Association for Infant Mental Health. [source]

Nonagenarian surgical admissions for the acute abdomen: who benefits?

Z. Toumi
Summary Introduction:, Patients 90 years and older form an increasing proportion of the general population. Outcomes of their acute surgical admissions are not well documented. Methods and materials:, Surgical management of 49 consecutive nonagenarian admissions (median age: 92 years) with an acute abdomen was compared with the management and outcome of 50 younger patients (median age: 53.5) admitted with a suspected acute abdomen over the same period. Results:, Nonagenarian group consisted of mainly women (71% vs. 50%; p = 0.003). The use of laboratory investigations and imaging was similar for the patients aged over 90 and the younger patients, although proportionately fewer nonagenarians were investigated by abdominal CT scan (8% vs. 24%). Of the 49 nonagenarian patients admitted, only 4% (n = 2) were operated on. In contrast, 38% (n = 19) of patients aged 50,59 (p = 0.0001) underwent a surgical intervention. A much greater proportion of nonagenarians died in hospital than patients in the 50,59 comparator group (16% nonagenarians vs. 4% comparator patients; p = 0.04). The very large majority of survivors in both age groups were discharged back to their preadmission domicile [39 (95%) nonagenarians vs. 46 (96%) comparator 50,59 year group]. Conclusions:, In this study, when compared with younger patients, very few nonagenarian patients (2%) with a suspected acute abdomen benefited from surgical admission. Instead, the large majority of nonagenarians either died or were discharged back to their home address without surgery. [source]

Capturing the voice of older consumers in relation to financial products and services

Carol Brennan
Abstract The purpose of this pilot study was to focus on the suitability of selected financial products for older people. Bank accounts and equity release products were selected for this study by an expert advisory panel. New marketing initiatives are being used to promote bank accounts, including forms of insurance, for the ,50+' market. Also, older people are now expected to provide for their retirement and it is anticipated that equity release will be one product which may be used to fund and maintain consumer lifestyles. In the first phase of the study, a questionnaire was distributed to 152 people aged over 50 years in Scotland. Eighty-three were completed, a response rate of 55%. The results informed the development of questions for the second phase which were discussed with 46 participants via the World Café in June 2008, enabling a deeper insight into their opinions. The research found that consumers had lost trust in financial product and service providers because of the perceived excessive profits of banks and lack of customer service. Further, many products and services were prohibited for or incurred extra costs to those aged over 60 or 65 years, leaving limited choices, and equity release products were seen as a last resort for those in financial difficulty. Although the profitability of banks has changed dramatically since the completion of data collection, the issues identified by older consumers in Scotland will be of international interest. The demographic changes resulting in an increasing proportion of elderly people in the population are reflected throughout the UK and many Organisation for Economic Co-operation and Development countries. Similar financial products and services, which were the focus of this study, are promoted internationally, offering opportunities to replicate the research methods. [source]

Earlier stress exposure and subsequent major depression in aging women

Stephanie Kasen
Abstract Objective Despite evidence that stress exposure earlier in the life course may have long-term consequences for psychopathology, most models of vulnerability for late life depression are limited to current stressors or to retrospective reports of stress history. This study estimates the influences of earlier stressors assessed longitudinally on subsequent major depressive disorder (MDD) in women at average age 60 (range 50,75). Method MDD, negative life events (NLE), and marital stress were assessed multiple times in a community-based sample of 565 women followed for three decades. Adverse events experienced in childhood also were assessed prior to outcome. Results Greater childhood adversity, earlier high levels of NLE and marital stress, and a more rapid increase in marital stress over time elevated the odds of MDD at average age 60 independent of all stressors and other salient risk factors. Childhood adversity was mediated in part by intervening risks. Prior depression, earlier poor health status, a more rapid deterioration in health with age, and current disability owing to physical problems also were related independently to later MDD. Conclusions These findings support the enduring effects of earlier stress burden on MDD in women into old age and, in light of the increasing proportion of older women in the population, have important clinical implications for identification and treatment of those at risk for depression. Findings also underscore the need to develop resources to counteract or buffer similar stress exposure in younger generations of women. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Romantic Relationships among Immigrant Adolescents1

Rosalind Berkowitz King
We examine the importance of the family and friendship group as two crucial developmental contexts for adolescent relationship experiences. We focus particularly on immigrant adolescents who make up an increasing proportion of the youth population and who come from cultural contexts with stronger family traditions than native-born adolescents. Using data from the National Longitudinal Study of Adolescent Health, we model the characteristics associated with having romantic relationships and participating in sex-related activities within relationships for immigrant adolescents, children of immigrants and adolescents in native-born families. First generation adolescents are less likely to enter romantic relationships than adolescents in native-born families, but those who do participate engage in similar sex-related activities as native-born youth. This evidence suggests that immigrant youth who enter romantic relationships are selective of the more assimilated to native adolescent norms of heterosexual behavior. The peer group is especially important for immigrant adolescents because it provides opportunities for romantic relationship involvement. [source]

Psychosocial response in emergency situations , the nurse's role

Dnurs, F. Hughes rn
Background:, It is critical to ensure that nurses have the skills and knowledge to respond effectively and to contribute to the psychosocial recovery of survivors of emergencies, particularly as an increasing proportion of the population is at risk of being exposed to a catastrophe. Over a decade ago it was reported that 16% of the world's population was at risk of experiencing some kind of catastrophic event. That has now risen with a total of 16% vulnerable to flood alone worldwide (Ministry of Health 2005). In the first semester of 2005, there were 174 natural disasters affecting 86 countries, resulting in the deaths of 5967 people, affecting a total of 60 million with an estimated damage of $6.3 billion (US$) (Centre for Research on the Epidemiology of Disasters 2005). Aim:, To describe the nursing contribution to the psychosocial recovery of survivors of emergencies during the emergency preparedness and planning stage and in promoting recovery over the longer term. Methods:, Data for this article was sourced from relevant literature including World Health Organization policy and guidelines regarding mental health in emergencies. Implications for education, training and practice:, It is vital that nurses realize they are too vulnerable to the effects of an emergency situation and that steps can be taken to protect nurses from enduring psychosocial effects. [source]

Adaptive radiation into ecological niches with eruptive dynamics: a comparison of tenthredinid and diprionid sawflies

Summary 1We tested the hypothesis that the bottom-up influence of coniferous plant resources promotes the probability of outbreak or eruptive dynamics in sawflies. The literature was examined for three geographical regions , North America north of Mexico, Europe and Japan. 2In each region tenthredinid sawflies (Hymenoptera: Tenthredinidae) were significantly more likely to be eruptive on conifers than on angiosperms. 3The diprionid sawflies (Hymenoptera: Diprionidae) that attack conifers exclusively showed a significantly higher probability of eruptive dynamics than the tenthredinid sawflies on angiosperms in two regions, North America and Europe, and in Japan the trend was in the same direction. 4The probability of species showing eruptive dynamics on coniferous hosts was not significantly different among tenthredinids and diprionids on conifers in North America, Europe and Japan. 5The weight of evidence supports the hypothesis of conifers supporting a higher percentage of eruptive species than angiosperms. 6In the adaptive radiation of tenthredinid sawflies from flowering plants onto conifers, larches (Larix) appear to be particularly favourable for colonization, but pines (Pinus) have not been colonized in any region, a pattern likely to be explained by the growth characteristics of the host plants. 7Among tenthredinid species in Europe, where sawfly/host relationships are best known, there is a significant trend for an increasing proportion of outbreaking species from herbs, to shrubs, to trees. 8The results indicate for the first time the strong bottom-up effects of plant resources on the population dynamics of sawflies, involving general features of host plant taxa and growth characteristics. [source]

Synthesis and characterization of hybrid nanocomposites comprising poly(vinyl alcohol) and colloidal silica

Mousumi De Sarkar
Abstract Organic,inorganic hybrid composite films were developed using poly(vinyl alcohol) (PVA) and an aqueous dispersion of colloidal silica of initial particle size of 15,30 nm. The hybrid films, prepared with varied proportion of colloidal silica (10,90 phr), were found to be transparent, indicating the nanolevel dispersion of the inorganic component over the polymer. Morphological studies further revealed no significant agglomeration of the silica domains embedded into the polymer matrix. A depression in glass transition temperature of PVA is observed with increasing proportion of silica. The degree of crystallinity also showed a decreasing trend with increasing amount of silica. However, the composite films demonstrated superior mechanical performances, higher resistances to dissolution in boiling water, and lower permeability compared with virgin PVA, owing to the better interaction between PVA and silica as well as the reinforcing action of nanosilica particles in the polymer matrix. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 27:152,162, 2008; Published online in Wiley InterScience ( DOI 10.1002/adv.20129 [source]

Differential migration of chiffchaffs Phylloscopus collybita and P. ibericus in Europe and Africa

Paulo Catry
Differential migration is a widespread, but poorly understood, phenomenon in birds. In this paper, we present the first detailed field study of differential migration in the Old World warbler (Sylviidae) family. We studied two chiffchaff Phylloscopus [collybita] semispecies: the common chiffchaff P. [c.] collybita and the Iberian chiffchaff P. [c.] ibericus. Using data collected at several latitudes in Europe and Africa, we present convincing evidence for differential distance migration of sexes in chiffchaffs, with females moving further than males. Interestingly, while there was a pronounced gradient in the sex-ratios in Europe and North Africa (with an increasing proportion of females with declining latitude), no clear pattern was found south of the Sahara, where sex-ratios were more male-biased than predicted by a simple latitude model. This suggests that, amongst the chiffchaffs wintering in West Africa, a large proportion is composed by Iberian birds, and provides support to previous suggestions that Iberian chiffchaffs are long distance migrants. Results from detailed studies in Senegal also show that chiffchaffs display differential timing of spring migration, with males leaving the winter quarters considerably earlier than females. The results are discussed in the framework of the three main (non-mutually exclusive) hypotheses attempting to explain the latitudinal segregation of the sexes. Given the relative failure of standard comparative studies to discriminate between competing single-factor hypotheses to explain differential migration, it is argued that the chiffchaff species complex might be particularly suited to study this issue using a new approach suggested by Cristol et al. (1999): detailed (further) comparisons between closely related species (such as the common and the Iberian chiffchaffs) could help identifying the key factors to be incorporated into optimality models that can predict relative distance of migration of different sex or age classes. [source]

Why are very large herbivores absent from Australia?

A new theory of micronutrients
Abstract Aim We propose a Megacatalyst Theory, based on the pivotal role of the micronutrients iodine (I), cobalt (Co) and selenium (Se), in answer to the body size anomaly of herbivores on different continents, and the previously unexplained absence of megaherbivores in certain environments. Location It is anomalous that megaherbivores are absent from Australia while present in even dry and nutrient-poor parts of southern Africa, and that they have been exterminated from the Americas, but not south-east Asia. Methods We hypothesize that I, Co and Se are micronutrients in quantity, but megacatalysts in effect, determining maximum body size and pace of life, hence whether energy is used by animals or fire. The Megacatalyst Theory suggests that the greater the reproductive rate and brain size relative to body size, the greater the probable demand for I, Co and Se. Results Balanced supply of I, Co and Se, within narrow tolerances, is elusive because of disparate cycles: I gravitates towards the sea, whereas Co and Se are concentrated in ultramafics and organic shales, respectively. Sufficiency of these micronutrients, at less than toxic concentrations, is vital for rapid metabolism and growth, particularly of the nervous system. Iodine controls thermogenesis, Co controls the gut fermentation supplying herbivores, and Se controls biochemical damage where both processes occur rapidly. The supply of Co allows vegetation to be metabolized instead of combusted, by promoting digestion of fibre by gut microbes. Herbivores demand I, Co and Se in greater concentrations than palatable plants necessarily contain, as an increasing proportion of energy is fermented from fibre with increasing body size. Economy of scale is limited by loss of I in urine (partly compensated by thyroid size), Co in faeces (partly compensated by gut compartments), and Se both ways. Main conclusions The larger the herbivore species, the more it may depend on supplementation in order to survive predation by humans. As body mass increases, Co becomes deficient before I, because it is essential for rumination, and cannot be absorbed by the skin. Moderate uplift of a fairly flat landscape sustainably supplies I from mineralized springs, and Co from rocks (and Se from both), avoiding the excess of I in the sea and the excess of Co on high mountains. Iodine and Se leached to groundwater under dry climates are inaccessible to herbivores on a continent as flat as Australia, where even kangaroos have limited fecundity and intelligence compared to southern African ruminants of similar body mass. Where springs and associated earth-licks were available in the late Pleistocene, megaherbivores could evolve to survive the era of domestication. [source]

GPs' perceptions of multiple-medicine use in older patients

Janne Moen PhD
Abstract Rationale, aim and objective, Multiple-medicine use (polypharmacy) is a growing problem for older patients, prescribers and health policy makers. The general practitioner (GP) is most often the main professional care provider; hence, improvements of treatment can only be carried out in concordance with GPs. The aim of this study was, therefore, to explore GPs' perspectives of treating older users of multiple medicines, using a qualitative approach. Method, Six focus groups, with four private GPs and 27 county-employed GPs, were analysed by using the framework method. Results, In contrast to definitions in most epidemiologic studies, the GPs gave a spontaneous definition of polypharmacy as ,the administration of more medicines than are clinically indicated'. They had problems stating both a cut-off number and which medicines should be included. Clinical practice guidelines were thought of as ,medicine generators', having an ambiguous effect on the GPs, who both trust them and find them difficult to apply. There was a perceived lack of communication between GPs and hospital specialists concerning their patients' medicines, which was further perceived to reduce treatment quality. The influence of patient pressure was acknowledged by the GPs as a factor contributing to the development of multiple-medicine use. Conclusions, The GPs felt insecure although surrounded by clinical practice guidelines. There is a need for policy makers to appreciate this paradox, as the problem is likely to grow in size and proportion. GPs must be empowered to handle the increasing proportion of older users of multiple medicines with individual agendas, receiving care from multiple specialists. [source]

Decline in hepatitis B infection observed after 11 years of regional vaccination among Danish drug users

B.K. Mössner
Abstract The aims of this study were to determine the current prevalence of viral hepatitis and HIV among drug users, and to compare this prevalence with previous findings in the same geographical region. Cross-sectional surveys of drug users attending treatment centers on the island of Funen with approximately 500,000 inhabitants were administered in 1996 and 2007. The 2007 prevalence estimates were: anti-HBc 50.2%, HBsAg 0.9%, anti-HCV 66.8%, HCV-RNA 40%, and anti-HIV 1.1%. The corresponding 1996 prevalence values were: anti-HBc 70% (P,<,0.0001), HBsAg 9.8% (P,<,0.0001), anti-HCV 82.8% (P,<,0.0001), HCV-RNA 56.3% (P,=,0.002), and anti-HIV 1% (P,=,1). The 2007 prevalence of viral hepatitis decreased due to the increasing proportion of non-injectors. Among injectors, the prevalence remained unchanged except for a significant decrease in HBsAg. The 2007 prevalence of ongoing HBV infection among infected (HBsAg/anti-HBc proportion) was the lowest that to our knowledge has been reported among drug-users. Vaccination coverage among susceptible persons tested in 2007 was 24%, compared to 0.7% in 1996. Therefore, despite an unchanged prevalence of anti-HBc among injecting drug users, a highly significant drop in HBsAg prevalence was seen during the last decade. This observation may be linked causally to an increase in hepatitis B vaccination of the susceptible population. Our findings suggest that even incomplete vaccination, without persistent protective anti-HBs levels, may induce an immune memory sufficient to prevent chronic infection upon transmission. J. Med. Virol. 82:1635,1639, 2010. 2010 Wiley-Liss, Inc. [source]

Effect of simulated resin-bonded fixed partial denture clinical conditions on resin cement mechanical properties

M. P. Walker
summary The purpose of this study was to determine changes in flexural properties of resin cement under simulated resin-bonded fixed partial denture (RBFPD) clinical conditions using aqueous ageing and cyclic loading. Panavia F flexural modulus and strength were measured by static loading to failure after 48-h and 60-day aqueous ageing at 37 °C with and without simulated cyclic occlusal loading. Panavia F sorption and solubility were also measured. Scanning electron microscopy (SEM) was used to characterize the morphology of the fractured surfaces. A two-factor anova (P , 0·05) indicated that cyclic loading produced a significant increase in the flexural modulus with no significant effect on the flexural strength. Conversely, aqueous ageing time produced a significant decrease in flexural strength with no effect on the flexural modulus. The SEM fracture analysis indicated that resin matrix fracture occurred in static-aqueous specimens; while in the aqueous-cycled specimens, resin matrix fracture occurred in addition to an increasing proportion of filler/resin interface fracture. Collectively, these outcomes suggest that initial degradation under simulated resin cement clinical function may be related to breakdown of the filler/resin interface bond, which could contribute to in vivo RBFPD resin cement cohesive failure. [source]

Is thermal oxidation at different temperatures suitable to isolate soil organic carbon fractions with different turnover?

Mirjam Helfrich
Abstract Findings of previous studies suggest that there are relations between thermal stability of soil organic matter (SOM), organo-mineral associations, and stability of SOM against microbial decay. We aimed to test whether thermal oxidation at various temperatures (200°C, 225°C, 275°C, 300°C, 400°C, or 500°C) is capable of isolating SOM fractions with increasing stability against microbial degradation. The investigation was carried out on soils (Phaeozem and Luvisol) under different land-use regimes (field, grassland, forest). The stability of the obtained soil organic carbon (SOC) fractions was determined using the natural- 13C approach for continuously maize-cropped soils and radiocarbon dating. In the Luvisol, thermal oxidation with increasing temperatures did not yield residual SOC fractions of increasing microbial stability. Even the SOC fraction resistant to thermal oxidation at 300°C contained considerable amounts of young, maize-derived C. In the Phaeozem, the mean 14C age increased considerably (from 3473 y BP in the mineral-associated SOC fraction to 9116 y BP in the residual SOC fraction after thermal oxidation at 300°C). An increasing proportion of fossil C (calculated based on 14C data) in residual SOC fractions after thermal oxidation with increasing temperatures indicated that this was mainly due to the relative accumulation of thermally stable fossil C. We conclude that thermal oxidation with increasing temperature was not generally suitable to isolate mineral-associated SOC fractions of increasing microbial stability. [source]

Variation in vegetative water use in the savannas of the North Australian Tropical Transect

Garry D. Cook
Abstract. The decline in tree density on sandy soils in savannas is highly correlated with declining mean annual rainfall along the North Australian Tropical Transect (NATT). We reanalyse various data on water use by individual trees and argue that a common relationship can be used to estimate annual water use by tree stands along the NATT from ca. 600 mm mean annual rainfall to at least 1600 mm. Where rainfall is less than 600 mm, trees of a given size use less water than at sites where rainfall is higher. We use these relationships to relate water use at the stand scale with mean annual rainfall along the NATT. From this we show that the empirical data imply that the minimum depth of sandy soil that needs to be exploited by trees declines with increasing aridity along the NATT from more than 5 m to less than 1 m. This finding is consistent with other observations and the pattern that with increasing aridity, an increasing proportion of rainfall coming from isolated storms rather than from periods of extended monsoon activity. [source]

Enamel ridge alignment in upper molars of ruminants in relation to their natural diet

T. M. Kaiser
Abstract Although it is generally thought that dental design reflects mechanical adaptations to particular diets, concrete concepts of such adaptations beyond the evolution of hypsodonty are largely missing. We investigated the alignment of enamel ridges in the occlusal molar surface of 37 ruminant species and tested for correlations with the percentage of grass in the natural diet. Independent of phylogenetic lineage, species that were either larger and/or included more grass in their natural diet showed a higher proportion of enamel ridges aligned at low angles to the direction of the chewing stroke. Possible explanations for this design are a potential alignment of grass blades in parallel to the molar tooth row, a potential increased proportion of a propalinal (anterior,posterior) chewing movement in grazers as opposed to a strictly transversal chewing stroke in browsers and the general distribution of forces along the occlusal surface during the chewing stroke. The latter will be less heterogenous (with less force peaks) with an increasing proportion of low-angle enamel ridges. While the validity of these explanations will have to be tested in further studies, the enamel ridge alignment represents a clear signal that deviates from an arbitrary distribution and hence most likely represents a functional adaptation. [source]

Moulting reduces freeze susceptibility in the Antarctic mite Alaskozetes antarcticus (Michael)

Abstract The effect of moulting on the cold hardiness of the oribatid mite Alaskozetes antarcticus (Michael) is investigated. Non moulting animals show clear seasonal patterns of cold hardiness with high supercooling points (SCPs) at the peak of summer and an increasing proportion of low SCPs with declining environmental temperatures. By contrast, both field-fresh and laboratory acclimated (5 °C) mites in the moult state are consistently found to have low SCPs regardless of environmental temperature. [source]

Stomatal crypts may facilitate diffusion of CO2 to adaxial mesophyll cells in thick sclerophylls

ABSTRACT In some plants, stomata are exclusively located in epidermal depressions called crypts. It has been argued that crypts function to reduce transpiration; however, the occurrence of crypts in species from both arid and wet environments suggests that crypts may play another role. The genus Banksia was chosen to examine quantitative relationships between crypt morphology and leaf structural and physiological traits to gain insight into the functional significance of crypts. Crypt resistance to water vapour and CO2 diffusion was calculated by treating crypts as an additional boundary layer partially covering one leaf surface. Gas exchange measurements of polypropylene meshes confirmed the validity of this approach. Stomatal resistance was calculated as leaf resistance minus calculated crypt resistance. Stomata contributed significantly more than crypts to leaf resistance. Crypt depth increased and accounted for an increasing proportion of leaf resistance in species with greater leaf thickness and leaf dry mass per area. All Banksia species examined with leaves thicker than 0.6 mm had their stomata in deep crypts. We propose that crypts function to facilitate CO2 diffusion from the abaxial surface to adaxial palisade cells in thick leaves. This and other possible functions of stomatal crypts, including a role in water use, are discussed. [source]

Relative Cohort Size: Source of a Unifying Theory of Global Fertility Transition?

Diane J. Macunovich
Using United Nations estimates of age structure and vital rates for 184 countries at five-year intervals from 1950 through 1995, this article demonstrates how changes in relative cohort size appear to have affected patterns of fertility across countries since 1950,not just in developed countries, but perhaps even more importantly in developing countries as they pass through the demographic transition. The increase in relative cohort size (defined as the proportion of males aged 15,24 relative to males aged 25,59), which occurs as a result of declining mortality rates among infants, children, and young adults during the demographic transition, appears to act as the mechanism that determines when the fertility portion of the transition begins. As hypothesized by Richard Easterlin, the increasing proportion of young adults generates a downward pressure on young men's relative wages (or on the size of landhold-ings passed on from parent to child), which in turn causes young adults to accept a tradeoff between family size and material wellbeing, setting in motion a "cascade" or "snowball" effect in which total fertility rates tumble as social norms regarding acceptable family sizes begin to change. [source]

Testing equivalence of Spanish and English versions: The LaMonica,Oberst (revised) patient satisfaction with nursing care scale,

Jean W. Lange
Abstract Despite recent emphasis on outcome measurement and an increasing proportion of Spanish speakers in the United States, most patient satisfaction studies exclude Spanish-speaking participants because Spanish versions of instruments are not available. A Spanish translation of the 15-item LaMonica,Oberst Patient Satisfaction Scale, completed by 64 Spanish-speaking patients living in the northeast and of predominantly Puerto Rican ancestry, produced two factors explaining 86.3% of score variation (,=.94 and .58). Evidence for equivalence to the English version and concurrent validity is presented. Generalizability and decision studies indicate that four additional items are needed on the dissatisfaction subscale to attain an acceptable dependability coefficient. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:438,451, 2002. [source]

Communication with Older Breast Cancer Patients

Ian S. Fentiman MD
Abstract:, An increasing proportion of patients with breast cancer are aged above 70 at the time of diagnosis and yet this particular age group has been underserved in terms of clinical research. Good communication between a doctor and a patient implies giving the advice and treatment most appropriate to that particular individual's needs, based upon their health and the tumor characteristics in the framework of their experience and belief system. Doctors need to be able to pick up both verbal and nonverbal cues and whenever possible to place the needs of the patient rather than her relatives as paramount. Consultations may be blighted at the onset by delays, unsympathetic staff, and patronizing doctors. Many older patients will wish to avoid mastectomy and for those with hormonally sensitive tumors wide excision and tamoxifen without axillary clearance or breast irradiation may provide a safe option. Undertreatment of those with hormonally insensitive cancer may lead to an increased risk of recurrence and premature death from breast cancer. Although there is an increasing realization of the need for clinical studies in older patients this group are grossly under-represented in trial portfolios [source]

What is the impact of missing Indigenous status on mortality estimates?

An assessment using record linkage in Western Australia
Abstract Background: The analysis aimed to assess the Indigenous status of an increasing number of deaths not coded with a useable Indigenous status from 1997 to 2002 and its impact on reported recent gains in Indigenous mortality. Methods: The Indigenous status of WA death records with a missing Indigenous status was determined based upon data linkage to three other data sources (Hospital Morbidity Database System, Mental Health Information System and Midwives Notification System). Results: Overall, the majority of un-coded cases were assigned an Indigenous status, with 5.9% identified as Indigenous from the M1 series and 7.5% from the M2 series. The significant increase in Indigenous male LE of 5.4 years from 1997 to 2002 decreased to 4.0 and 3.6 years using the M1 and M2 series, respectively, but remained significant. For Indigenous females, the non-significant increase in LE of 1.8 years from 1997 to 2002 decreased to 1.0 and 0.6 years. Furthermore, annual all-cause mortality rates were higher than in the original data for both genders, but the significant decline for males remained. Conclusion: Through data linkage, the increasing proportion of deaths not coded with a useable Indigenous status was shown to impact on Indigenous mortality statistics in Western Australia leading to an overestimate of improvements in life expectancy. Greater attention needs to be given to better identification and recording of Indigenous identifiers if real improvements in health status are to be demonstrated. A system that captures an individual's Indigenous status once and is reflected in all health and administrative data systems needs consideration within Australia. [source]