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Reduced Availability (reduced + availability)
Selected AbstractsCoping Strategies Developed as a Result of Social Structure and Conflict: Kosovo in the 1990sDISASTERS, Issue 2 2000Kate Ogden The end of 1989 brought with it political and economic decisions which resulted in Kosovo being stripped of its autonomy and the Albanian population being expelled from their jobs. These facts combined with ethnic tensions created a decade of conflict and oppression affecting hundreds of thousands of innocent civilians. Thousands of Kosovars moved overseas to seek work to support families at home, altering the way of life of the population of Kosovo irredeemably. The loss of income had serious repercussions on food security throughout the 1990s; possibilities of purchasing food were diminished, control on goods in 1998 reduced availability of foodstuffs, conflict affected accessibility to markets and shops and consequently food intake and nutritional status was compromised. The most vulnerable were those who had no family members overseas. Mass displacement of population due to ethnic cleansing during the war of spring 1999, further jeopardised food security status. Destruction at this time rendered large parts of Kosovo useless and resulted in a shift in the determinant of vulnerability in the post-war period: destruction of houses, land, livestock and agricultural products as well as loss of family members, became a far more pertinent indicator of food insecurity. The strong and clear links between conflict, socio-economic issues and food security are highlighted and discussed in this paper. [source] Cation exchange in forest soils: the need for a new perspectiveEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2008D. S. Ross Summary The long-term sustainability of forest soils may be affected by the retention of exchangeable nutrient cations such as Ca2+ and the availability of potentially toxic cations such as Al3+. Many of our current concepts of cation exchange and base cation saturation are largely unchanged since the beginnings of soil chemistry over a century ago. Many of the same methods are still in use even though they were developed in a period when exchangeable aluminium (Al) and variable charge were not generally recognized. These concepts and methods are not easily applicable to acid, highly organic forest soils. The source of charge in these soils is primarily derived from organic matter (OM) but the retention of cations, especially Al species, cannot be described by simple exchange phenomena. In this review, we trace the development of modern cation exchange definitions and procedures, and focus on how these are challenged by recent research on the behaviour of acid forest soils. Although the effective cation exchange capacity (CECe) in an individual forest soil sample can be easily shown to vary with the addition of strong base or acid, it is difficult to find a pH effect in a population of different acid forest soil samples. In the very acidic pH range below ca 4.5, soils will generally have smaller concentrations of adsorbed Al3+. This can be ascribed to a reduced availability of weatherable Al-containing minerals and a large amount of weak, organic acidity. Base cation saturation calculations in this pH range do not provide a useful metric and, in fact, pH is modelled better if Al3+ is considered to be a base cation. Measurement of exchangeable Al3+ with a neutral salt represents an ill-defined but repeatable portion of organically complexed Al, affected by the pH of the extractant. Cation exchange in these soils can be modelled if assumptions are made as to the proportion of individual cations that are non-specifically bound by soil OM. Future research should recognize these challenges and focus on redefining our concepts of cation retention in these important soils. [source] Pleiotropic phenotypes caused by an opal nonsense mutation in an essential gene encoding HMG-CoA reductase in fission yeastGENES TO CELLS, Issue 6 2009Yue Fang Schizosaccharomyces pombe genome contains an essential gene hmg1+ encoding the sterol biosynthetic enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR). Here, we isolated an allele of the hmg1+ gene, hmg1-1/its12, as a mutant that showed sensitivities to high temperature and to FK506, a calcineurin inhibitor. The hmg1-1 allele contained an opal nonsense mutation in its N-terminal transmembrane domain, yet in spite of the mutation a full-length protein was produced, suggesting a read-through termination codon. Consistently, overexpression of the hmg1-1 mutant gene suppressed the mutant phenotypes. The hmg1-1 mutant showed hypersensitivity to pravastatin, an HMGR inhibitor, suggesting a defective HMGR activity. The mutant treated with FK506 caused dramatic morphological changes and showed defects in cell wall integrity, as well as displayed synthetic growth phenotypes with the mutant alleles of genes involved in cytokinesis and cell wall integrity. The mutant exhibited different phenotypes from those of the disruption mutants of ergosterol biosynthesis genes, and it showed normal filipin staining as well as showed normal subcellular localization of small GTPases. These data suggest that the pleiotropic phenotypes reflect the integrated effects of the reduced availability of ergosterol and various intermediates of the mevalonate pathway. [source] Climatic effects on the breeding phenology and reproductive success of an arctic-nesting goose speciesGLOBAL CHANGE BIOLOGY, Issue 9 2008MARIE-HÉLÈNE DICKEY Abstract Climate warming is pronounced in the Arctic and migratory birds are expected to be among the most affected species. We examined the effects of local and regional climatic variations on the breeding phenology and reproductive success of greater snow geese (Chen caerulescens atlantica), a migratory species nesting in the Canadian Arctic. We used a long-term dataset based on the monitoring of 5447 nests and the measurements of 19 234 goslings over 16 years (1989,2004) on Bylot Island. About 50% of variation in the reproductive phenology of individuals was explained by spring climatic factors. High mean temperatures and, to a lesser extent, low snow cover in spring were associated with an increase in nest density and early egg-laying and hatching dates. High temperature in spring and high early summer rainfall were positively related to nesting success. These effects may result from a reduction in egg predation rate when the density of nesting geese is high and when increased water availability allows females to stay close to their nest during incubation recesses. Summer brood loss and production of young at the end of the summer increased when values of the summer Arctic Oscillation (AO) index were either very positive (low temperatures) or very negative (high temperatures), indicating that these components of the breeding success were most influenced by the regional summer climate. Gosling mass and size near fledging were reduced in years with high spring temperatures. This effect is likely due to a reduced availability of high quality food in years with early spring, either due to food depletion resulting from high brood density or a mismatch between hatching date of goslings and the timing of the peak of plant quality. Our analysis suggests that climate warming should advance the reproductive phenology of geese, but that high spring temperatures and extreme values of the summer AO index may decrease their reproductive success up to fledging. [source] Regenerative potential of human skeletal muscle during agingAGING CELL, Issue 2 2002Valérie Renault Summary In this study, we have investigated the consequences of aging on the regenerative capacity of human skeletal muscle by evaluating two parameters: (i) variation in telomere length which was used to evaluate the in vivo turn-over and (ii) the proportion of satellite cells calculated as compared to the total number of nuclei in a muscle fibre. Two skeletal muscles which have different types of innervation were analysed: the biceps brachii, a limb muscle, and the masseter, a masticatory muscle. The biopsies were obtained from two groups: young adults (23 ± 1.15 years old) and aged adults (74 ± 4.25 years old). Our results showed that during adult life, minimum telomere lengths and mean telomere lengths remained stable in the two muscles. The mean number of myonuclei per fibre was lower in the biceps brachii than in the masseter but no significant change was observed in either muscle with increasing age. However, the number of satellite cells, expressed as a proportion of myonuclei, decreased with age in both muscles. Therefore, normal aging of skeletal muscle in vivo is reflected by the number of satellite cells available for regeneration, but not by the mean number of myonuclei per fibre or by telomere lengths. We conclude that a decrease in regenerative capacity with age may be partially explained by a reduced availability of satellite cells. [source] Effects of HIV/AIDS on Maternity Care Providers in KenyaJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 5 2008Janet M. Turan ABSTRACT Objective: To explore the impact of HIV/AIDS on maternity care providers in labor and delivery in a high HIV-prevalence setting in sub-Saharan Africa. Design: Qualitative one-on-one in-depth interviews with maternity care providers. Setting: Four health facilities providing labor and delivery services (2 public hospitals, a public health center, and a small private maternity hospital) in Kisumu, Nyanza Province, Kenya. Participants: Eighteen maternity care providers, including 14 nurse/midwives, 2 physician assistants, and 2 physicians (ob/gyn specialists). Results: The HIV/AIDS epidemic has had numerous adverse effects and a few positive effects on maternity care providers in this setting. Adverse effects include reductions in the number of health care providers, increased workload, burnout, reduced availability of services in small health facilities when workers are absent due to attending HIV/AIDS training programs, difficulties with confidentiality and unwanted disclosure, and maternity care providers' fears of becoming HIV infected and the resulting stigma and discrimination. Positive effects include improved infection control procedures on maternity wards and enhanced maternity care provider knowledge and skills. Conclusion: A multifaceted package including policy, infrastructure, and training interventions is needed to support maternity care providers in these settings and ensure that they are able to perform their critical roles in maternal healthcare and prevention of HIV/AIDS transmission. [source] Lactational State Modifies Alcohol Pharmacokinetics in WomenALCOHOLISM, Issue 6 2007Marta Yanina Pepino Background: Given the physiological adaptations of the digestive system during lactation, the present study tested the hypothesis that lactation alters alcohol pharmacokinetics. Methods: Lactating women who were exclusively breastfeeding a 2- to 5-month-old infant and 2 control groups of nonlactating women were studied. The first control group consisted of women who were exclusively formula-feeding similarly aged infants, whereas the other consisted of women who had never given birth. A within-subjects design study was conducted such that women drank a 0.4 g/kg dose of alcohol following a 12-hour overnight fast during one test session (fasted condition) or 60 minutes after consuming a standard breakfast during the other (fed condition). Blood alcohol concentration (BAC) levels and mood states were obtained at fixed intervals before and after alcohol consumption. Results: Under both conditions, the resultant BAC levels at each time point were significantly lower and the area under the blood alcohol time curve were significantly smaller in lactating women when compared with the 2 groups of nonlactating women. That such changes were due to lactation per se and not due to recent parturient events was suggested by the finding that alcohol pharmacokinetics of nonlactating mothers, who were tested at a similar time postpartum, were no different from women who had never given birth. Despite lower BAC levels in lactating mothers, there were no significant differences among the 3 groups of women in the stimulant effects of alcohol. However, lactating women did differ in the sedative effects of alcohol when compared with nulliparous but not formula-feeding mothers. That is, both groups of parous women felt sedated for shorter periods of time when compared with nulliparous women. Conclusions: The systemic availability of alcohol was diminished during lactation. However, the reduced availability of alcohol in lactating women did not result in corresponding changes in the subjective effects of alcohol. [source] MYELINATION DEFICIT IN NERVE OF SUCKLING RATS DUE TO CYCLOLEUCINE -INDUCED DEFICIENCY OF METHYL DONORSJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000R. Bianchi We used cycloleucine (CL) , which prevents methionine conversion to S-adenosyl-methionine (SAMe) by inhibiting ATP-L-methionine-adenosyl-transferase (MAT) , to characterize the lipid and protein changes induced by methyl donors deficit in peripheral nerve and brain myelin in rats during development. We have previously shown that CL (400 mg/kg ip) given to suckling rats at days 7, 8, 12, and 13 after birth reduced brain and sciatic nerve weight gain, brain myelin content, protein, phospholipid (PL), and galactolipid concentration in comparison to control. Among PLs, only sphingomyelin (SPH) significantly increased by 35,50%. SAMe p-toluensulphonate (SAMe-SD4) (100 mg/kg, ip) given daily from day 7, as with exogenous SAMe, partially prevented some lipid alterations induced by CL, particularly galactolipid and SPH. To test the ability of CL to affect PL metabolism we have measured de novo PL biosynthesis, ex vivo in nerve homogenates (in comparison with brain homogenates) from control and CL-treated animals killed at day 18 after birth, starting from labelled substrates ([3H]-choline, specific activity 20 mCi/mmol) in a Tris/HCl buffer, containing 5 mM MgCl2, 0.2 mM EDTA, 0.1 mM ATP, and 0.5 mM of the labelled substrates. After 60 min incubation, lipids were extracted, PL separated by TLC, and corresponding silica gel fractions scraped and counted in a liquid scintillator. Phosphatidylcholine enrichment in labelled choline resulted in slight increases in brain and sciatic nerve of CL-treated rats, suggesting an increased synthesis rate via the Kennedy pathway, possibly due to the reduced availability of methyl donors. Interestingly, choline incorporation into SPH in brain and nerve myelin resulted in significant increases of 30,40%. In agreement with the observed decrease of galactolipid content and the relative increase in SPH, these data suggest an alteration in sphingolipid metabolism after CL. Among proteins, in sciatic nerves of CL-treated pups the relative content of a number of polypeptides, namely the 116, 90, 66, 58, and 56 kDa bands, decreased, whereas others increased; the most abundant PNS protein, protein zero, remained unchanged. The analyses of myelin basic protein isoforms revealed a dramatic increase in the 14.0 and 18.5 forms, indicating early active myelination. SAMe-SD4 treatment counteracted, and in some cases normalized, these changes. In summary, methyl donor deficiency induced by MAT inhibition produces myelin lipid and protein alterations, partly counteracted by SAMe-SD4 administration. The financial support of Telethon-Italy (grant No. D 51) is gratefully acknowledged. [source] Ecology and conservation of common bottlenose dolphins Tursiops truncatus in the Mediterranean SeaMAMMAL REVIEW, Issue 2 2009GIOVANNI BEARZI ABSTRACT 1Bottlenose dolphins Tursiops truncatus are amongst the best-known cetaceans. In the Mediterranean Sea, however, modern field studies of cetaceans did not start until the late 1980s. Bottlenose dolphins have been studied only in relatively small portions of the basin, and wide areas remain largely unexplored. 2This paper reviews the ecology, behaviour, interactions with fisheries and conservation status of Mediterranean bottlenose dolphins, and identifies threats likely to have affected them in historical and recent times. 3Whilst intentional killing was probably the most important cause of mortality until the 1960s, important ongoing threats include incidental mortality in fishing gear and the reduced availability of key prey caused by overfishing and environmental degradation throughout the region. Additional potential or likely threats include the toxic effects of xenobiotic chemicals, epizootic outbreaks, direct disturbance from boating and shipping, noise, and the consequences of climate change. 4The flexible social organization and opportunistic diet and behaviour of bottlenose dolphins may allow them to withstand at least some of the effects of overfishing and habitat degradation. However, dolphin abundance is thought to have declined considerably in the region and management measures are needed to prevent further decline. 5Management strategies that could benefit bottlenose dolphins, such as sustainable fishing, curbing marine pollution and protecting biodiversity, are already embedded in legislation and treaties. Compliance with those existing commitments and obligations should be given high priority. [source] Pentoxifylline improves haemoglobin and interleukin-6 levels in chronic kidney diseaseNEPHROLOGY, Issue 3 2010PAOLO FERRARI ABSTRACT Aim: To assess whether pentoxifylline improves anaemia of chronic kidney disease (CKD) via suppression of interleukin-6 (IL-6) and improved iron mobilization. Background: CKD patients may have elevated IL-6 and tumour necrosis factor alpha levels. These cytokines can increase hepcidin production, which in turn reduces iron release from macrophages resulting in reduced availability of iron for erythropoiesis. In experimental models, pentoxifylline was shown to reduce IL-6 expression. Methods: We studied 14 patients with stages 4,5 CKD (glomerular filtration rate <30mL/min per 1.73 m2) due to non-inflammatory renal diseases. None of the patients had received immunosuppressive or erythropoietin-stimulating agents or parenteral iron. Patients had weekly blood tests for iron studies and cytokines during a control run-in period of 3 weeks and during 4 weeks of pentoxifylline treatment. Results: Ten patients (eGFR 23 ± 6 mL/min) completed the study. At the end of the run-in period average haemoglobin was 111 ± 5 g/L, ferritin 92 ± 26 µg/L, transferrin saturation 15 ± 3% and circulating IL-6 10.6 ± 3.8 pg/mL. Tumour necrosis factor alpha values were below threshold for detection. Treatment with pentoxifylline reduced circulating IL-6 (6.6 ± 1.6 pg/mL, P < 0.01), increased transferrin saturation (20 ± 5%, P < 0.003) and decreased serum ferritin (81 ± 25 µg/L, P = NS). Haemoglobin increased after the second week of pentoxifylline, reaching 123 ± 6 g/L by week 4 (P < 0.001). Conclusions: Pentoxifylline reduces circulating IL-6 and improves haemoglobin in non-inflammatory moderate to severe CKD. These changes are associated with changes in circulating transferrin saturation and ferritin, suggesting improved iron release. It is hypothesized that pentoxifylline improves iron disposition possibly through modulation of hepcidin. [source] Seed production and population density decline approaching the range-edge of Cirsium speciesNEW PHYTOLOGIST, Issue 2 2003Alistair S. Jump Summary ,,Patterns in population density and abundance, community composition, seed production and morphological traits were assessed across the UK geographical range of Cirsium acaule, Cirsium heterophyllum and Cirsium arvense based on the expectation that environmental favourability declines from core to periphery of a species range. ,,These traits were measured in natural populations along a latitudinal transect in the UK and using botanical survey data. ,,A significant decline in population density and seed production occurs approaching the range edges of C. acaule and C. heterophyllum. There is no latitudinal trend in these traits in the widespread C. arvense and no latitudinal pattern to variation in morphological traits or community composition in any of these species. ,,Although seed production is reduced at the range edge of C. acaule and C. heterophyllum, peripheral populations of these species may persist through clonal reproduction. Low seed production may interact with reduced availability of favourable habitat to limit range expansion in these species. [source] Periodontal condition of the mandibular anterior dentition in patients with conventional and self-ligating bracketsORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2008N Pandis Structured Abstract Authors,,, Pandis N, Vlachopoulos K, Polychronopoulou A, Madianos P, Eliades T Objectives,,, To explore whether the use of self-ligating brackets is associated with better values for periodontal indices because of the lack of elastomeric modules and concomitantly, reduced availability of retentive sites for microbial colonization and plaque accumulation. Setting and Sample Population,,, Private practice of the first author. Patients were selected using the following inclusion criteria: age range 12,17 years, fixed appliances on both arches, aligned mandibular arch, and absence of oral habits and anterior crossbites. Materials and Methods,,, Prospective cohort investigation. Participants were grouped for bracket type, thus 50 patients formed the conventional bracket cohort and 50 patients the self-ligating bracket cohort. Both cohorts were followed with the purpose to examine periodontal status. Average length of follow-up was 18 months. This time period was considered adequate for a proportion of study participants to experience the outcome of interest. Outcome variables were plaque index, gingival index, calculus index, and probing depth for the two bracket cohorts. Results,,, No difference was found in the indices recorded between the two bracket cohorts studied. Conclusion,,, Under the conditions as applied in this study, the self-ligating brackets do not have an advantage over conventional brackets with respect to the periodontal status of the mandibular anterior teeth. [source] Interferon, tryptophan and depressionACTA NEUROPSYCHIATRICA, Issue 1 2003D. Fekkes Depression is a frequent comorbid disorder of many inflammatory diseases and it is suggested that brain inflammatory processes have a pathogenic role in mood dysregulation. Several immunocompromised patients have been treated with cytokines and long-term treatments have resulted in a variety of neuropsychiatric side-effects. The objective of the study was to present evidence for an association between the induction of neuropsychiatric side-effects during treatment with interferon-, (IFN-,) and changes in serotonergic and immunological parameters. Moreover, the use of IFN-,-induced depression as a paradigm for research into the pathophysiology of depressive disorders in general will be discussed. This literature review focused on the relationships between tryptophan, serotonin, cytokines and depression associated with interferon treatment. Immunotherapy with IFN-, influences several immunological and serotonergic parameters, and induces in most patients neurovegetative, somatic and depressive symptoms. Literature findings indicate that the development of depressive symptoms in patients undergoing cytokine therapy are secondary to cytokine induction and could be mediated by a reduced availability of tryptophan to the brain, resulting ultimately in decreased serotonergic activity. Changes in the metabolism of tryptophan and consequently of serotonin may play a role in the pathophysiology of interferon-induced depression. Studies on interferon-induced neuropsychiatric side-effects may be a promising research paradigm and shed light on the role of immunological and serotonergic factors in the pathogenesis of depressive disorders in general. However, first the appropriate symptomatology of the interferon-induced depressive states has to be documented. [source] | |||||||||||||