Home About us Contact
|
Home About us Contact | ||
|
|
||
Unexplained
Terms modified by Unexplained Selected AbstractsPatients presenting with somatic complaints: epidemiology, psychiatric co-morbidity and managementINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 1 2003Kurt Kroenke MD Abstract Somatic symptoms are the leading cause of outpatient medical visits and also the predominant reason why patients with common mental disorders such as depression and anxiety initially present in primary care. At least 33% of somatic symptoms are medically unexplained, and these symptoms are chronic or recurrent in 20% to 25% of patients. Unexplained or multiple somatic symptoms are strongly associated with coexisting depressive and anxiety disorders. Other predictors of psychiatric co-morbidity include recent stress, lower self-rated health and higher somatic symptom severity, as well as high healthcare utilization, difficult patient encounters as perceived by the physician, and chronic medical disorders. Antidepressants and cognitive-behavioural therapy are both effective for treatment of somatic symptoms, as well as for functional somatic syndromes such as irritable bowel syndrome, fibromyalgia, pain disorders, and chronic headache. A stepped care approach is described, which consists of three phases that may be useful in the care of patients with somatic symptoms. Copyright © 2003 Whurr Publishers Ltd. [source] Temperate marine reserves: global ecological effects and guidelines for future networksCONSERVATION LETTERS, Issue 6 2009Gavin B. Stewart Abstract Marine reserves, areas closed to all fishing and other extractive activities, provide a refuge for species of commercial and conservation importance. Given the considerable resources committed to designing temperate reserve networks, we synthesized data from temperate reserves worldwide to determine their ecological effects. In common with other studies, we found higher density, biomass, and species richness in temperate marine reserves compared to adjacent exploited areas. However, there was considerable heterogeneity in magnitude of effect among reserves, variability which was largely unexplained by species or reserve characteristics. Our analytical approach allowed for formal power analyses, indicating that detection of large reserve effects in temperate systems globally requires monitoring at least 37 reserves. These results must be qualified by the limitations of data available and will undoubtedly vary at different spatio-temporal scales and for different focal species, but provide guidance for the design and monitoring of future marine conservations plans. International commitments toward establishment of multiple reserves offer a unique opportunity to assess reserve effectiveness; this opportunity can only be realized if reserves are designed to achieve clear and quantifiable objectives and are adequately monitored before and after establishment, based on appropriate power analyses, to assess how well those objectives are achieved. [source] Antidepressant use in a nationally representative sample of community-dwelling US Latinos with and without depressive and anxiety disorders,DEPRESSION AND ANXIETY, Issue 7 2009Hector M. González Ph.D. Abstract Background: Antidepressant drugs are among the most widely prescribed drugs in the United States; however, little is known about their use among major ethnic minority groups. Method: Collaborative Psychiatric Epidemiology Surveys (CPES) data were analyzed to calculate nationally representative estimates of Latino and non-Latino White adults antidepressant use. Setting: The 48 coterminous United States was the setting. Participants: Household residents aged 18 years and older (N=9,250). Main outcome: Past year antidepressant use. Results: Compared to non-Latino Whites, few Latinos, primarily Mexican Americans, with 12-month depressive and/or anxiety disorders reported past year antidepressant use. Mexican Americans (OR=0.48; 95%CI=0.30,0.77) had significantly lower odds of use compared to non-Latino Whites, which were largely unaffected by factors associated with access to care. Over half of antidepressant use was by respondents not meeting 12-month criteria for depressive or anxiety disorders. Lifetime depressive and anxiety disorders explained another 21% of past year antidepressant use, leaving another 31% of drug use unexplained. Discussion: We found a disparity in antidepressant use for Mexican Americans compared to non-Latino Whites that was not accounted for by differences in need and factors associated with access to care. About one third of antidepressant use was by respondents not meeting criteria for depressive or anxiety disorders. Our findings underscore the importance of disaggregating Latino ethnic groups. Additional work is needed to understand the medical and economic value of antidepressant use beyond their primary clinical targets. Depression and Anxiety, 2009. Published 2009 Wiley-Liss, Inc. [source] Bioenergetics and the epigenome: Interface between the environment and genes in common diseasesDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 2 2010Douglas C. Wallace Abstract Extensive efforts have been directed at using genome-wide association studies (GWAS) to identify the genes responsible for common metabolic and degenerative diseases, cancer, and aging, but with limited success. While environmental factors have been evoked to explain this conundrum, the nature of these environmental factors remains unexplained. The availability of and demands for energy constitute one of the most important aspects of the environment. The flow of energy through the cell is primarily mediated by the mitochondrion, which oxidizes reducing equivalents from hydrocarbons via acetyl-CoA, NADH + H+, and FADH2 to generate ATP through oxidative phosphorylation (OXPHOS). The mitochondrial genome encompasses hundreds of nuclear DNA (nDNA)-encoded genes plus 37 mitochondrial DNA (mtDNA)-encoded genes. Although the mtDNA has a high mutation rate, only milder, potentially adaptive mutations are introduced into the population through female oocytes. In contrast, nDNA-encoded bioenergetic genes have a low mutation rate. However, their expression is modulated by histone phosphorylation and acetylation using mitochondrially-generated ATP and acetyl-CoA, which permits increased gene expression, growth, and reproduction when calories are abundant. Phosphorylation, acetylaton, and cellular redox state also regulate most signal transduction pathways and activities of multiple transcription factors. Thus, mtDNA mutations provide heritable and stable adaptation to regional differences while mitochondrially-mediated changes in the epigenome permit reversible modulation of gene expression in response to fluctuations in the energy environment. The most common genomic changes that interface with the environment and cause complex disease must, therefore, be mitochondrial and epigenomic in origin. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:114,119. [source] Talking About Intentional ObjectsDIALECTICA, Issue 2 2006Michael Gorman Tim Crane has recently defended the view that all intentional states have objects, even when these objects do not exist. In this note I first set forth some crucial elements of Crane's view: his reasons for accepting intentional objects, his rejection of certain ways of thinking about them, and his distinction between the ,substantial' and the ,schematic' notion of an object. I then argue that while Crane's account successfully explains what intentional objects are not, it leaves unexplained how it could make sense to say that intentional objects need not exist. Finally I propose that we can do justice to Crane's reasons for talking about intentional objects by re-interpreting talk about intentional objects as talk about the truth- or satisfaction-conditions of intentional states. [source] The emergence of the chordate body plan: some puzzles and problemsACTA ZOOLOGICA, Issue 1 2010Thurston C. Lacalli Abstract Lacalli, T.C. 2010. The emergence of the chordate body plan: some puzzles and problems. ,Acta Zoologica (Stockholm) 91: 4,10 Rather than being sessile filter feeders, ancestral chordates are now thought to have evolved from more active benthic animals, possibly hemichordate-like, that took to swimming, to generate something resembling modern amphioxus. This general picture conceals a number of specific problems that underline how little we understand the transition in detail. I will address three. First, and closest to resolution is the issue of dorsoventral inversion, which has implications for understanding how an internalized brain evolved. This is because the mouth, dorsal after inversion, has first to be moved out of the way. Its migration down the left side of the head during amphioxus development may be a recapitulation of this event. Two other puzzles, both further from resolution are: (1) the significance, if any, of the neurenteric canal, which may be telling us something important about the true nature of deuterostomy, specifically whether hemichordates and echinoderms are deuterostomes for a different reason than chordates, and (2) whether the functional digestive tract of chordates is a secondary replacement of an earlier structure whose fate remains unexplained. Resolving these latter two issues will require a better understanding of molecular level events during development in protochordates and their immediate invertebrate relatives. [source] Clinical features associated with medically unexplained stroke-like symptoms presenting to an acute stroke unitEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2005F. S. Nazir In many areas of secondary care, symptoms unexplained by disease account for around one-third of all patients seen. We sought to investigate patients presenting with medically unexplained stroke-like symptoms to identify distinguishing features which may help to identify a non-organic aetiology. Patients given a discharge diagnosis of medically unexplained stroke-like symptoms over the preceding 11 years were identified retrospectively from a prospectively completed stroke unit database. Age- and sex-matched controls with ischaemic or haemorrhagic stroke or transient ischaemic attack were also identified. Clinical features on presentation, ischaemic risk factors, alcohol history, marital status and history of depression or anxiety were examined. Previous or subsequent admissions with medically unexplained syndromes were also examined via record linkage with hospital discharge records. A medically unexplained syndrome was assumed to be present if an International Classification of Diseases 9 discharge code for one or more of the thirteen conditions forming recognized functional syndromes was given. Logistic regression was applied to determine predictors of non-organicity. One hundred and five patients and controls, 1.6% of all stroke unit admissions were identified, 62% (65 patients) were females. Mean age was 50.3 ± 14.9. Compared with age- and sex-matched controls patients with medically unexplained stroke-like symptoms were significantly more probable to have a headache at presentation (47% vs. 26%, P = 0.0004), have a diagnosis of one or more additional medically unexplained syndromes (24% vs. 11%, P = 0.007) but significantly less probable to present with symptoms of vertebrobasilar dysfunction (32% vs. 61%, P < 0.0001). A history of anxiety or depression, as recorded in the notes, was not found to be associated with a medically unexplained presentation. Medically unexplained stroke-like presentations are common (1.6% of all stroke presentations), they are most strongly predicted by the presence of other functional somatic syndromes, headache and the absence of symptoms of vertebrobasilar dysfunction. [source] Computational motor control: feedback and accuracyEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2008Emmanuel Guigon Abstract Speed/accuracy trade-off is a ubiquitous phenomenon in motor behaviour, which has been ascribed to the presence of signal-dependent noise (SDN) in motor commands. Although this explanation can provide a quantitative account of many aspects of motor variability, including Fitts' law, the fact that this law is frequently violated, e.g. during the acquisition of new motor skills, remains unexplained. Here, we describe a principled approach to the influence of noise on motor behaviour, in which motor variability results from the interplay between sensory and motor execution noises in an optimal feedback-controlled system. In this framework, we first show that Fitts' law arises due to signal-dependent motor noise (SDNm) when sensory (proprioceptive) noise is low, e.g. under visual feedback. Then we show that the terminal variability of non-visually guided movement can be explained by the presence of signal-dependent proprioceptive noise. Finally, we show that movement accuracy can be controlled by opposite changes in signal-dependent sensory (SDNs) and SDNm, a phenomenon that could be ascribed to muscular co-contraction. As the model also explains kinematics, kinetics, muscular and neural characteristics of reaching movements, it provides a unified framework to address motor variability. [source] The effect of socioeconomic factors on voter turnout in Finland: A register-based study of 2.9 million votersEUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 5 2005PEKKA MARTIKAINEN The analyses are based on individual-level register data from electoral wards from the parliamentary elections of 1999 linked to population registration data on personal characteristics covering the whole 25 to 69 year-old Finnish electorate. The results show that income and housing tenure are more important determinants of turnout among older voters than among younger voters, whereas education has a dominant role in determining young people's turnout. Moreover, class has maintained its discriminatory power in determining turnout in all age groups even though working-class under-representation in participation can be partly attributable to previously obtained educational attainment. Furthermore, the lower turnout of younger voters remains unexplained even if socioeconomic factors are held constant. Lower turnout among lower social classes and among the young will affect the legitimacy of the prevalent model of party democracy. [source] The effect of thiamine supplementation on tumour proliferationFEBS JOURNAL, Issue 15 2001A metabolic control analysis study Thiamine deficiency frequently occurs in patients with advanced cancer and therefore thiamine supplementation is used as nutritional support. Thiamine (vitamin B1) is metabolized to thiamine pyrophosphate, the cofactor of transketolase, which is involved in ribose synthesis, necessary for cell replication. Thus, it is important to determine whether the benefits of thiamine supplementation outweigh the risks of tumor proliferation. Using oxythiamine (an irreversible inhibitor of transketolase) and metabolic control analysis (MCA) methods, we measured an in vivo tumour growth control coefficient of 0.9 for the thiamine-transketolase complex in mice with Ehrlich's ascites tumour. Thus, transketolase enzyme and thiamine clearly determine cell proliferation in the Ehrlich's ascites tumour model. This high control coefficient allows us to predict that in advanced tumours, which are commonly thiamine deficient, supplementation of thiamine could significantly increase tumour growth through transketolase activation. The effect of thiamine supplementation on tumour proliferation was demonstrated by in vivo experiments in mice with the ascites tumour. Thiamine supplementation in doses between 12.5 and 250 times the recommended dietary allowance (RDA) for mice were administered starting on day four of tumour inoculation. We observed a high stimulatory effect on tumour growth of 164% compared to controls at a thiamine dose of 25 times the RDA. This growth stimulatory effect was predicted on the basis of correction of the pre-existing level of thiamine deficiency (42%), as assayed by the cofactor/enzyme ratio. Interestingly, at very high overdoses of thiamine, ,,2500 times the RDA, thiamine supplementation had the opposite effect and caused 10% inhibition of tumour growth. This effect was heightened, resulting in a 36% decrease, when thiamine supplementation was administered from the 7th day prior to tumour inoculation. Our results show that thiamine supplementation sufficient to correct existing thiamine deficiency stimulates tumour proliferation as predicted by MCA. The tumour inhibitory effect at high doses of thiamine is unexplained and merits further study. [source] Second Language Reading Research on Passage Content and Gender: Challenges for the Intermediate-Level CurriculumFOREIGN LANGUAGE ANNALS, Issue 4 2001Cindy Brantmeier PhD Howevel, a careful examination of available studies reveals disparities among research methods and procedures, thus making it difficult to formulate theories for re-examining the intermediate-level course, where the reading of lengthy, authentic texts begins. To complicate matters further, females begin to outnumber males at the intermediate level, and this gap widens at the advanced levels (Chavez, 2001). This article , through a careful review of the relevant literature , shows that much of the L2 reading process at the intermediate level remains unexplained. Finally, a call for more research at the intermediate level that examines key variables, such as passage content and gender, is made. [source] Detecting the impact of oceano-climatic changes on marine ecosystems using a multivariate index: The case of the Bay of Biscay (North Atlantic-European Ocean)GLOBAL CHANGE BIOLOGY, Issue 1 2008GEORGES HEMERY Abstract Large-scale univariate climate indices (such as NAO) are thought to outperform local weather variables in the explanation of trends in animal numbers but are not always suitable to describe regional scale patterns. We advocate the use of a Multivariate Oceanic and Climatic index (MOCI), derived from ,synthetic' and independent variables from a linear combination of the total initial variables objectively obtained from Principal Component Analysis. We test the efficacy of the index using long-term data from marine animal populations. The study area is the southern half of the Bay of Biscay (43°,47°N; western Europe). Between 1974 and 2000 we monitored cetaceans and seabirds along 131000 standardized line transects from ships. Fish abundance was derived from commercial fishery landings. We used 44 initial variables describing the oceanic and atmospheric conditions and characterizing the four annual seasons in the Bay of Biscay. The first principal component of our MOCI is called the South Biscay Climate (SBC) index. The winter NAO index was correlated to this SBC index. Inter-annual fluctuations for most seabird, cetacean and fish populations were significant. Boreal species (e.g. gadiformes fish species, European storm petrel and Razorbill ,) with affinities to cold temperate waters declined significantly over time while two (Puffin and Killer Whale) totally disappeared from the area during the study period. Meridional species with affinities to hotter waters increased in population size. Those medium-term demographic trends may reveal a regime shift for this part of the Atlantic Ocean. Most of the specific observed trends were highly correlated to the SBC index and not to the NAO. Between 40% and 60% of temporal variations in species abundance were explained by the multivariate SBC index suggesting that the whole marine ecosystem is strongly affected by a limited number of physical parameters revealed by the multivariate SBC index. Aside the statistical error of the field measurements, the remaining variation unexplained by the physical characteristics of the environment correspond to the impact of anthropogenic activities such overfishing and oil-spills. [source] Predicting Patterns of Mammography Use: A Geographic Perspective on National Needs for Intervention ResearchHEALTH SERVICES RESEARCH, Issue 4 2002Julie Legler Objective. To introduce a methodology for planning preventive health service research that takes into account geographic context. Data Sources. National Health Interview Survey (NHIS) self-reports of mammography within the past two years, 1987, and 1993,94. Area Resource File (ARF), 1990. Database of mammography intervention research studies conducted from 1984 to 1994. Design. Bayesian hierarchical modeling describes mammography as a function of county-level socioeconomic data and explicitly estimates the geographic variation unexplained by the county-level data. This model produces county use estimates (both NHIS-sampled and unsampled), which are aggregated for entire states. The locations of intervention research studies are examined in light of the statewide mammography utilization estimates. Data Extraction. Individual level NHIS data were merged with county-level data from the ARF. Principal Findings. State maps reveal the estimated distribution of mammography utilization and intervention research. Eighteen states with low mammography use reported no intervention research activity. County-level occupation and education were important predictors for younger women in 1993,94. In 1987, they were not predictive for any demographic group. Conclusions. Opportunities exist to improve the planning of future intervention research by considering geographic context. Modeling results suggest that the choice of predictors be tailored to both the population and the time period under study when planning interventions. [source] Helicobacter pylori -Associated Chronic Gastritis and Unexplained Iron Deficiency Anemia: a Reliable Association?HELICOBACTER, Issue 6 2003Stéphane Nahon Abstract Background and aim., About 35% of iron deficiency anemia cases remain unexplained after a gastrointestinal evaluation. An association between Helicobacter pylori and iron malabsorption has been suggested. The aim of this study was to determine whether H. pylori -associated chronic gastritis is linked to unexplained iron deficiency anemia in adults. Methods., From 1996 to 2001, we identified 105 patients with unexplained iron deficiency anemia after upper endoscopy, colonoscopy, small bowel radiographic examination and duodenal biopsies. Two biopsies were obtained from the gastric antrum and two from the corpus of each patient. Gastritis status was described according to the Sydney System and H. pylori infection was assessed by an immunohistochemical test on biopsy specimens. This group was compared to a control group matched for sex and age. Results., There were 76 women and 29 men (mean age 57.4 ± 21.4 years) examined in the study. A H. pylori -associated chronic gastritis was identified in 63 cases (60%) vs. 45 cases (43%) cases in the control group (p < .01). Atrophic gastritis was significantly associated with iron deficiency anemia compared with the control group [16 (15%) vs. 6 (6%); p < .03]. In the unexplained iron deficiency anemia group, (1) patients with chronic gastritis were significantly younger (52 ± 22 vs. 64 ± 20 years; p < .005), and (2) chronic gastritis was not linked to sex [sex ratio (male/female): 0.5 vs. 0.34, p = .34]. The prevalence of H. pylori infection was similar between premenopausal and postmenopausal women [28 (27%) vs. 26 (25%); p = .7] with iron deficiency anemia. Conclusion.,H. pylori infection and chronic gastritis, especially atrophic gastritis, are significantly associated with unexplained iron deficiency anemia. Relationships between H. pylori -associated chronic gastritis and unexplained iron deficiency anemia should be considered. [source] Habitat selection in a recovering Osprey Pandion haliaetus populationIBIS, Issue 3 2001ASKO LOHMUS Sequential habitat occupation and productivity of Ospreys Pandion haliaetus were studied in the recovering Estonian population from 1985 to 1999. During this period, the number of known nests increased from five to 32. Nest-sites closer to the foraging grounds and with more lakes nearby were occupied first and had the highest productivity. Through a reduction in the quality of sites available, the average productivity of Ospreys decreased as their numbers rose, consistent with despotic distribution models. The sites occupied first during the recolonization were also those that had been the last to be abandoned during the population's decline prior to 1980. However, newcomers preferred sites near established pairs. Therefore, conspecific attraction explained some stochasticity left unexplained by deterministic resource models. [source] An Outbreak of Respiratory Diseases among Workers at a Water-Damaged Building , A Case ReportINDOOR AIR, Issue 3 2000MARKKU SEURI Abstract We describe a military hospital building with severe, repeated and enduring water and mold damage, and the symptoms and diseases found among 14 persons who were employed at the building. The exposure of the employees was evaluated by measuring the serum immunoglobulin G (IgG)-antibodies against eight spieces of mold and yeast common in Finnish water and mold damaged buildings and by sampling airborne viable microbes within the hospital. The most abundant spieces was Sporobolomyces salmonicolor. All but one of the employees reported some building-related symptoms, the most common being a cough which was reported by nine subjects. Four new cases of asthma, confirmed by S. salmonicolor inhalation provocation tests, one of whom was also found to have alveolitis, were found among the hospital personnel. In addition, seven other workers with newly diagnosed rhinitis reacted positively in nasal S. salmonicolor provocation tests. Skin prick tests by Sporobolomyces were negative among all 14 workers. Exposure of the workers to mold and yeast in the indoor air caused an outbreak of occupational diseases, including asthma, rhinitis and alveolitis. The diseases were not immunoglobulin E (IgE)-mediated but might have been borne by some other, as yet unexplained, mechanism. [source] The von Hippel-Lindau tumor suppressor gene expression level has prognostic value in neuroblastomaINTERNATIONAL JOURNAL OF CANCER, Issue 3 2006Jasmien Hoebeeck Abstract Deletions of the short arm of chromosome 3 are often observed in a specific subset of aggressive neuroblastomas (NBs) with loss of distal 11q and without MYCN amplification. The critical deleted region encompasses the locus of the von Hippel-Lindau gene (VHL, 3p25). Constitutional loss of function mutations in the VHL gene are responsible for the VHL syndrome, a dominantly inherited familial cancer syndrome predisposing to a variety of neoplasms, including pheochromocytoma. Pheochromocytomas are, like NB, derived from neural crest cells, but, unlike NB, consist of more mature chromaffin cells instead of immature neuroblasts. Further arguments for a putative role of VHL in NB are its function as oxygen sensitizer and the reported relation between hypoxia and dedifferentiation of NB cells, leading to a more aggressive phenotype. To test the possible involvement of VHL in NB, we did mRNA expression analysis and sought evidence for VHL gene inactivation. Although no evidence for a classic tumor suppressor role for VHL in NB could be obtained, a strong correlation was observed between reduced levels of VHL mRNA and low patient survival probability (p = 0.013). Furthermore, VHL appears to have predictive power in NTRK1 (TRKA) positive tumor samples with presumed favorable prognosis, which makes it a potentially valuable marker for more accurate risk assessment in this subgroup of patients. The significance of the reduced VHL expression levels in relation to NB tumor biology remains unexplained, as functional analysis demonstrated no clear effect of the reduction in VHL mRNA expression on protein stability of its downstream target hypoxia-inducible factor ,. © 2006 Wiley-Liss, Inc. [source] Observed and SST-forced seasonal rainfall variability across tropical AmericaINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2001Vincent Moron Abstract Three experiments starting from different initial conditions have been made with the ECHAM-4 atmospheric General Circulation Model (GCM) integrated at T30 resolution forced with the observed sea-surface temperature (SST) over the period 1960,1994. The tropical America modes of seasonal rainfall anomalies whose time variation is most accurately simulated by the GCM have been searched for using Singular Value Decomposition Analyses (SVDA) and Canonical Correlation Analysis (CCA) between observed and model fields. The leading modes revealed by SVDA and CCA are highly similar, even though the ordering of the modes showed some fluctuation. A first skilful rainfall anomaly mode has weights of the same sign almost everywhere in tropical America, except along the western coast and the sub-tropical margins. This mode appears in all of the four seasons assessed. A second major skilful mode is usually a bipolar north,south (N,S) rainfall anomaly pattern (clear in December,March, DJFM; March,May, MAM; and June,September, JJAS). A large portion of the skill of the first rainfall anomaly mode (same sign anomalies across tropical America except small patches along the western coast) is through variance that is in common with the Southern Oscillation Index (SOI). In addition to forcing from the central/eastern tropical Pacific SST, there also appears a contribution from contrasting SST anomalies in the tropical Atlantic. This rainfall mode is usually a regional portion of a more large-scale mode encompassing at least the whole tropical zone (especially in DJFM, MAM and September,November, SON). Analysis of the relationship of this mode with GCM circulation features reveals that a rainfall deficit (respectively excedent) over the main rainbelt of the tropical America region is associated with strengthening (respectively weakening) of the sub-tropical westerly jet streams, a global warming (respectively cooling) of the tropical atmosphere, an anomalous divergence (respectively convergence) in the lower levels and an anomalous convergence (respectively divergence) in the upper levels over tropical America and in the region of the Atlantic Inter-tropical Convergence Zone (ITCZ). Such global features are not so apparent for the dominant mode of JJAS, even though the correlations with El Niño,Southern Oscillation (ENSO) indicators (as SOI or NINO3 SST index) are as high as for the other seasons. The bipolar N,S rainfall anomaly mode in tropical America is mostly related to anomalous N,S gradient of SST anomalies in the tropical Atlantic. The atmospheric circulation anomalies emphasize changes in 850 hPa meridional winds in the tropical Atlantic. However, there is also interannual variance of this rainfall mode in both the model and observations that is unexplained by tropical Atlantic SSTs, but which is explained by central/eastern tropical Pacific SSTs and, potentially, SSTs from other tropical and extratropical areas. This is especially true in MAM. Some differences in the details of the model and observed teleconnection patterns are noted. Such differences can be used to statistically adjust the model simulations using the CCA or SVDA modes as basis patterns. Both statistical approaches have been applied and the results are consistent between the two. The increase of skill is stronger when temporal correlation (the pattern correlation) between the model and observed pattern is high (low) as for JJAS. The skill is moderate to high around the whole Amazon basin, but remains relatively low inside the Amazon basin, though reliability of the observations themselves may influence this result. Averaged over all the seasons, about 15,35% (35,55%) of the interannual grid-box (regional) seasonal rainfall variance is skilfully simulated from the observed SST forcing. Copyright © 2001 Royal Meteorological Society [source] An obesity drug sibutramine reduces brain natriuretic peptide (BNP) levels in severely obese patientsINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 4 2010D. Taner Ertugrul Summary Objectives:, Sibutramine is a selective inhibitor of the reuptake of monoamines. Plasma levels of brain natriuretic peptide (BNP) appear to be inversely associated with body mass index (BMI) in subjects with and without heart failure for reasons that remain unexplained. The aim of this study was to investigate the possible influence of sibutramine treatment on BNP levels in severely obese patients. Methods:, Fifty-two severely obese female patients with BMI > 40 kg/m2 were included to this study. The women were recommended to follow a weight-reducing daily diet of 25 kcal/kg of ideal body weight. During the treatment period, all patients were to receive 15 mg of sibutramine once a day. Blood chemistry tests were performed before the onset of the medication and after 12 weeks of treatment. Results:, None of the subjects was withdrawn from the study because of the adverse effects of sibutramine. Body weight (108.8 ± 13.3 kg vs. 101.7 ± 15.6 kg, p < 0.001), BMI (44.6 ± 4.6 kg/m2 vs. 41.8 ± 5.7 kg/m2, p < 0.001) and BNP [8.6 (0.5,49.5) ng/l vs. 3.1 (0.2,28.6) ng/l, p = 0.018] levels were significantly decreased after 12 weeks of sibutramine treatment. Total cholesterol (5.19 ± 0.90 mmol/l vs. 4.82 ± 1.05 mmol/l respectively; p < 0.001), low-density lipoprotein-cholesterol (3.26 ± 0.86 mmol/l vs. 2.99 ± 0.40 mmol/l respectively; p = 0.008), levels were significantly decreased; however, there was no significant alteration in high-density lipoprotein-cholesterol and triglyceride levels. Conclusion:, This study has shown a decrease in BNP levels which may lead to improvement in cardiac outcome after sibutramine treatment. Further randomised studies are needed to be conducted to clarify the relationship between sibutramine and BNP. [source] Patients presenting with somatic complaints: epidemiology, psychiatric co-morbidity and managementINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 1 2003Kurt Kroenke MD Abstract Somatic symptoms are the leading cause of outpatient medical visits and also the predominant reason why patients with common mental disorders such as depression and anxiety initially present in primary care. At least 33% of somatic symptoms are medically unexplained, and these symptoms are chronic or recurrent in 20% to 25% of patients. Unexplained or multiple somatic symptoms are strongly associated with coexisting depressive and anxiety disorders. Other predictors of psychiatric co-morbidity include recent stress, lower self-rated health and higher somatic symptom severity, as well as high healthcare utilization, difficult patient encounters as perceived by the physician, and chronic medical disorders. Antidepressants and cognitive-behavioural therapy are both effective for treatment of somatic symptoms, as well as for functional somatic syndromes such as irritable bowel syndrome, fibromyalgia, pain disorders, and chronic headache. A stepped care approach is described, which consists of three phases that may be useful in the care of patients with somatic symptoms. Copyright © 2003 Whurr Publishers Ltd. [source] Does Corporate Transparency Contribute to Efficient Resource Allocation?JOURNAL OF ACCOUNTING RESEARCH, Issue 4 2009JERE R. FRANCIS ABSTRACT This paper examines whether a country's corporate transparency environment, which includes the quality of accounting information, contributes to efficient resource allocation. Based on a cross-country study of 37 manufacturing industries in 37 countries, we provide three pieces of related evidence. First, we find the contemporaneous correlations in industry growth rates across country pairs are higher when there is a greater level of corporate transparency in the country pairs, after controlling for country-level economic and financial development. Second, we find the influence of transparency on these correlations is stronger when country pairs are at similar levels of economic development (GDP). Finally, when we control for the level of transparency explained by a country's institutions in place, we find that residual transparency (unexplained by country-level factors) is associated with industry-specific growth rates. Taken together, the results are consistent with corporate transparency facilitating the allocation of resources across industry sectors. [source] DISAPPEARING DIVIDENDS: CHANGING FIRM CHARACTERISTICS OR LOWER PROPENSITY TO PAY?JOURNAL OF APPLIED CORPORATE FINANCE, Issue 1 2001Eugene F. Fama The proportion of U.S. firms paying dividends drops sharply during the 1980s and 1990s. Among NYSE, AMEX, and Nasdaq firms, the proportion of dividend payers falls from 66.5% in 1978 to only 20.8% in 1999. The decline is due in part to an avalanche of new listings that tilts the population of publicly traded firms toward small firms with low profitability and strong growth opportunities,the timeworn characteristics of firms that typically do not pay dividends. But this is not the whole story. The authors' more striking finding is that, no matter what their characteristics, firms in general have become less likely to pay dividends. The authors use two different methods to disentangle the effects of changing firm characteristics and changing propensity to pay on the percent of dividend payers. They find that, of the total decline in the proportion of dividend payers since 1978, roughly one-third is due to the changing characteristics of publicly traded firms and two-thirds is due to a reduced propensity to pay dividends. This lower propensity to pay is quite general,dividends have become less common among even large, profitable firms. Share repurchases jump in the 1980s, and the authors investigate whether repurchases contribute to the declining incidence of dividend payments. It turns out that repurchases are mainly the province of dividend payers, thus leaving the decline in the percent of payers largely unexplained. Instead, the primary effect of repurchases is to increase the already high payouts of cash dividend payers. [source] Male-biased parasitism by common helminths is not explained by sex differences in body size or spleen mass of breeding cormorants Phalacrocorax auritusJOURNAL OF AVIAN BIOLOGY, Issue 3 2008Stacey A. Robinson In vertebrates, males are often more parasitised than conspecific females. This bias in parasitism might result from sex differences in parasite exposure and/or susceptibility to infection. Such information is important for testing hypotheses about allocation of resources to life histories of males and females and for testing hypotheses about factors thought to influence parasite fitness and parasite dynamics. We tested whether double-crested cormorants Phalacrocorax auritus exhibit male-biased parasitism by gut helminths. The prevalence of nematode Contracaecum spp. and trematode Drepanocaphalus spathans infections was ,90% and 39%, respectively. Cestode, primarily Paradilepis caballeroi and acanthocephalan Andracantha gravida infections were less common (<10%). Male and female cormorants did not differ in prevalence of infection by any helminth species. However, males had twice the abundance and intensity of Contracaecum spp. infections and twice the intensity of D. spathans infections than found in females. For common parasites showing male-biased parasitism, degree of parasitism was also unrelated to body size or mass in either sex. Males and females did not differ in spleen mass and spleen mass was unrelated to abundance of common parasites. Furthermore, abundance of trematodes and nematodes was not correlated. At present, male biases in parasitism by nematodes and trematodes in cormorants are independent patterns that remain unexplained, but are most likely attributable to sex differences in exposure and/or immunological differences not yet assessed. [source] A comparison of nocturnal call counts of migrating birds and reflectivity measurements on Doppler radarJOURNAL OF AVIAN BIOLOGY, Issue 4 2004Andrew Farnsworth Several studies have found that the peak in bird density in the atmosphere during nocturnal migration occurs before midnight, while the peak in vocalizations from migrating birds occurs after midnight, in the hours just before dawn. In a recent study, the patterns of calling from a single species of migrating birds correlated well with the patterns of density estimates of migrating birds. We test the null hypothesis that the patterns of reflectivity measurements and number of vocalizations during nocturnal migration are not related. We sampled radar data and nocturnal flight calls during spring and fall 2000 in northwestern South Carolina and southeastern New York. We analyzed changes in the hour-to-hour patterns of bird density and vocalizations for 556 hours on 58 nights. We also analyzed the night-to-night changes in the patterns of peak hour bird density and peak hour of vocalizations on 32 nights. We found that most of the hour-to-hour and night-to-night patterns of density and vocalization counts are significantly related and reject the null hypothesis. However, despite significant relationships between reflectivity measurements and vocalization counts, a great deal of variation in vocalization counts remains unexplained. These results suggest that factors other than bird density are responsible for the variation in vocalizing by migrating birds. [source] Intrapopulation variation in reproduction by female eastern kingbirds Tyrannus tyrannus: the impacts of age, individual performance, and breeding siteJOURNAL OF AVIAN BIOLOGY, Issue 3 2004Michael T. Murphy I used data from a 13-year study of eastern kingbirds Tyrannus tyrannus from central New York, USA, to evaluate the relative impact of female age and body size on reproduction. I also calculated repeatabilities of reproductive traits for both females and the sites where they bred in an attempt to evaluate the relative contribution of each to intrapopulation variation in reproduction. Female age had a strong influence on timing of breeding (breeding date advanced by one day for each year of life), but was not a significant source of variation for clutch size, egg mass, number of young to hatch or fledge, or total seasonal production. Repeatabilities of breeding date for females and sites were both significant (0.284 and 0.181, respectively), but the only other significant repeatabilities were for female clutch size (0.282) and female egg mass (0.746). Among-year repeatabilities of breeding date for females who bred at two or more sites over their lifetime were as high as those for females that were site faithful. Thus, breeding date was probably affected independently by the female and site. No measure of productivity exhibited a repeatable pattern in comparisons made among females or sites. All reproductive traits were entered as dependent variables in a series of stepwise multiple regression analyses in an attempt to identify female properties (size, lifespan and condition) that might be linked proximately to differences in breeding statistics. I found that (a) large birds tended to breed the earliest, (b) clutch size was independent of female size, condition and lifespan, (c) female body size and egg size were correlated positively, but (d) production of young was independent of all measured female properties. Reproduction appears to be linked more closely to the female than to the site. Body size accounts for a portion of the repeatable portion of breeding date and egg mass, but most of the intrapopulation variation in these and other traits remained unexplained. [source] Patterns of species richness on very small islands: the plants of the Aegean archipelagoJOURNAL OF BIOGEOGRAPHY, Issue 7 2006Maria Panitsa Abstract Aim, To investigate the species,area relationship (SAR) of plants on very small islands, to examine the effect of other factors on species richness, and to check for a possible Small Island Effect (SIE). Location, The study used data on the floral composition of 86 very small islands (all < 0.050 km2) of the Aegean archipelago (Greece). Methods, We used standard techniques for linear and nonlinear regression in order to check several models of the SAR, and stepwise multiple regression to check for the effects of factors other than area on species richness (,habitat diversity', elevation, and distance from nearest large island), as well as the performance of the Choros model. We also checked for the SAR of certain taxonomic and ecological plant groups that are of special importance in eastern Mediterranean islands, such as halophytes, therophytes, Leguminosae and Gramineae. We used one-way anova to check for differences in richness between grazed and non-grazed islands, and we explored possible effects of nesting seabirds on the islands' flora. Results, Area explained a small percentage of total species richness variance in all cases. The linearized power model of the SAR provided the best fit for the total species list and several subgroups of species, while the semi-log model provided better fits for grazed islands, grasses and therophytes. None of the nonlinear models explained more variance. The slope of the SAR was very high, mainly due to the contribution of non-grazed islands. No significant SIE could be detected. The Choros model explained more variance than all SARs, although a large amount of variance of species richness still remained unexplained. Elevation was found to be the only important factor, other than area, to influence species richness. Habitat diversity did not seem important, although there were serious methodological problems in properly defining it, especially for plants. Grazing was an important factor influencing the flora of small islands. Grazed islands were richer than non-grazed, but the response of their species richness to area was particularly low, indicating decreased floral heterogeneity among islands. We did not detect any important effects of the presence of nesting seabird colonies. Main conclusions, Species richness on small islands may behave idiosyncratically, but this does not always lead to a typical SIE. Plants of Aegean islets conform to the classical Arrhenius model of the SAR, a result mainly due to the contribution of non-grazed islands. At the same time, the factors examined explain a small portion of total variance in species richness, indicating the possible contribution of other, non-standard factors, or even of stochastic effects. The proper definition of habitat diversity as pertaining to the taxon examined in each case is a recurrent problem in such studies. Nevertheless, the combined effect of area and a proxy for environmental heterogeneity is once again superior to area alone in explaining species richness. [source] Multivariate analysis of a fine-scale breeding bird atlas using a geographical information system and partial canonical correspondence analysis: environmental and spatial effectsJOURNAL OF BIOGEOGRAPHY, Issue 11 2004Nicolas Titeux Abstract Aim, To assess the relative roles of environment and space in driving bird species distribution and to identify relevant drivers of bird assemblage composition, in the case of a fine-scale bird atlas data set. Location, The study was carried out in southern Belgium using grid cells of 1 × 1 km, based on the distribution maps of the Oiseaux nicheurs de Famenne: Atlas de Lesse et Lomme which contains abundance for 103 bird species. Methods, Species found in < 10% or > 90% of the atlas cells were omitted from the bird data set for the analysis. Each cell was characterized by 59 landscape metrics, quantifying its composition and spatial patterns, using a Geographical Information System. Partial canonical correspondence analysis was used to partition the variance of bird species matrix into independent components: (a) ,pure' environmental variation, (b) spatially-structured environmental variation, (c) ,pure' spatial variation and (d) unexplained, non-spatial variation. Results, The variance partitioning method shows that the selected landscape metrics explain 27.5% of the variation, whilst ,pure' spatial and spatially-structured environmental variables explain only a weak percentage of the variation in the bird species matrix (2.5% and 4%, respectively). Avian community composition is primarily related to the degree of urbanization and the amount and composition of forested and open areas. These variables explain more than half of the variation for three species and over one-third of the variation for 12 species. Main conclusions, The results seem to indicate that the majority of explained variation in species assemblages is attributable to local environmental factors. At such a fine spatial resolution, however, the method does not seem to be appropriated for detecting and extracting the spatial variation of assemblages. Consequently, the large amount of unexplained variation is probably because of missing spatial structures and ,noise' in species abundance data. Furthermore, it is possible that other relevant environmental factors, that were not taken into account in this study and which may operate at different spatial scales, can drive bird assemblage structure. As a large proportion of ecological variation can be shared by environment and space, the applied partitioning method was found to be useful when analysing multispecific atlas data, but it needs improvement to factor out all-scale spatial components of this variation (the source of ,false correlation') and to bring out the ,pure' environmental variation for ecological interpretation. [source] Skeletal Fluorosis From Instant Tea,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2008Michael P Whyte MD Abstract Introduction: Skeletal fluorosis (SF) can result from prolonged consumption of well water with >4 ppm fluoride ion (F,; i.e., >4 mg/liter). Black and green teas can contain significant amounts of F,. In 2005, SF caused by drinking 1,2 gallons of double-strength instant tea daily throughout adult life was reported in a 52-yr-old woman. Materials and Methods: A 49-yr-old woman developed widespread musculoskeletal pains, considered fibromyalgia, in her mid-30s. Additionally, she had unexplained, increasing, axial osteosclerosis. She reported drinking 2 gallons of instant tea each day since 12 yr of age. Fluoxetine had been taken intermittently for 5 yr. Ion-selective electrode methodology quantitated F, in her blood, urine, fingernail and toenail clippings, tap water, and beverage. Results: Radiographs showed marked uniform osteosclerosis involving the axial skeleton without calcification of the paraspinal, intraspinal, sacrotuberous, or iliolumbar ligaments. Minimal bone excrescences affected ligamentous attachments in her forearms and tibias. DXA Z-scores were +10.3 in the lumbar spine and +2.8 in the total hip. Her serum F, level was 120 ,g/liter (reference range, 20,80 ,g/liter), and a 24-h urine collection contained 18 mg F,/g creatinine (reference value, <3). Fingernail and toenail clippings showed 3.50 and 5.58 mg F,/kg (control means, 1.61 and 2.02, respectively; ps < 0.001). The instant tea beverage, prepared as usual extra strength using tap water with ,1.2 ppm F,, contained 5.8 ppm F,. Therefore, the tea powder contributed ,35 mg of the 44 mg daily F, exposure from her beverage. Fluoxetine provided at most 3.3 mg of F, daily. Conclusions: SF from habitual consumption of large volumes of extra strength instant tea calls for recognition and better understanding of a skeletal safety limit for this modern preparation of the world's most popular beverage. [source] Genetic and Environmental Determinants of Peak Bone Mass in Young Men and WomenJOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2002Fiona E. A. Mcguigan Ph.D. Abstract Peak bone mass is an important risk factor for the development of osteoporosis in later life. Previous work has suggested that genetic, intrauterine, and environmental factors all contribute to the regulation of bone mass, but the ways in which they interact with each other to do so remain poorly understood. In this study, we investigated the relationship between peak bone mass and polymorphisms of the vitamin D receptor (VDR), estrogen receptor (ER) ,, and collagen type I,1 (COLIA1) genes in relation to other factors such as birth weight, lifestyle diet, and exercise in a population-based cohort of 216 women and 244 men in their early 20s. Stepwise multiple regression analysis showed that body weight was the strongest predictor of bone mineral density (BMD) in women, accounting for 16.4% of the variance in spine BMD and 8.4% of the variance in femoral neck BMD. Other significant predictors were VDR genotype (3.8%) and carbohydrate intake (1.6%) at the spine and vitamin D intake (3.4%) and ER genotype (3.4%) at the femoral neck. Physical activity was the strongest predictor of BMD in men, accounting for 6.7% of the variance at the spine and 5.1% at the hip. Other significant predictors were body weight (5%) and ER PvuII genotype (2.8%) at the spine and weight (3.4%) and alcohol intake (2%) at the femoral neck. Birth weight was not a significant predictor of BMD at either site but COLIA1 genotype significantly predicted birth weight in women, accounting for 4.3% of the variance. We conclude that peak bone mass is regulated by an overlapping but distinct set of environmental and genetic influences that differ in men and women. However, much of the variance in BMD was unexplained by the variables studied here, which suggests that either most of the genes that regulate BMD remain to be discovered or major environmental influences on BMD exist that have not yet been identified. [source] Relationships Between Bone Mineral Density and Incident Vertebral Fracture Risk with Raloxifene Therapy,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2002Somnath Sarkar Ph.D. Abstract Although low absolute values of bone mineral density (BMD) predict increased fracture risk in osteoporosis, it is not certain how well increases in BMD with antiresorptive therapy predict observed reductions in fracture risk. This work examines the relationships between changes in BMD after 1 year or 3 years of raloxifene or placebo therapy and the risk for new vertebral fractures at 3 years. In the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, 7705 postmenopausal women with osteoporosis were randomized to placebo or raloxifene 60 mg/day or 120 mg/day. Relationships between baseline BMD and changes in BMD from baseline with the risk of new vertebral fractures were analyzed in this cohort using logistic regression models with the raloxifene doses pooled. As has been observed in other populations, women with the lowest baseline lumbar spine or femoral neck BMD in the MORE cohort had the greatest risk for vertebral fractures. Furthermore, for any percentage change, either increase or decrease in femoral neck or lumbar spine BMD at 1 year or 3 years, raloxifene-treated patients had a statistically significantly lower vertebral fracture risk compared with placebo-treated patients. The decrease in fracture risk with raloxifene was similar across the range of percentage change in femoral neck BMD observed at 3 years; patients receiving raloxifene had a 36% lower risk of vertebral fracture compared with those receiving placebo. At any percentage change in femoral neck and lumbar spine BMD observed at 1 year, raloxifene treatment decreased the risks of new vertebral fractures at 3 years by 38% and 41%, respectively. The logistic regression model showed that the percentage changes in BMD with raloxifene treatment accounted for 4% of the observed vertebral fracture risk reduction, and the other 96% of the risk reduction remains unexplained. The present data show that the measured BMD changes observed with raloxifene therapy are poor predictors of vertebral fracture risk reduction with raloxifene therapy. [source] | ||||||||||||||||||||||||||||||||||||||||||||||