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Small Proportion (small + proportion)
Kinds of Small Proportion Selected AbstractsSmall proportions: what to report for confidence intervals?,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2005Hilde Tobi Abstract Purpose It is generally agreed that a confidence interval (CI) is usually more informative than a point estimate or p -value, but we rarely encounter small proportions with CI in the pharmacoepidemiological literature. When a CI is given it is sporadically reported, how it was calculated. This incorrectly suggests one single method to calculate CIs. To identify the method best suited for small proportions, seven approximate methods and the Clopper,Pearson Exact method to calculate CIs were compared. Methods In a simulation study for 90-, 95- and 99%CIs, with sample size 1000 and proportions ranging from 0.001 to 0.01, were evaluated systematically. Main quality criteria were coverage and interval width. The methods are illustrated using data from pharmacoepidemiology studies. Results Simulations showed that standard Wald methods have insufficient coverage probability regardless of how the desired coverage is perceived. Overall, the Exact method and the Score method with continuity correction (CC) performed best. Real life examples showed the methods to yield different results too. Conclusions For CIs for small proportions (,,,,0.01), the use of the Exact method and the Score method with CC are advocated based on this study. Copyright © 2005 John Wiley & Sons, Ltd. [source] Overweight and obesity in a rural amerindian population in Oaxaca, Southern Mexico, 1968,2000AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2007Robert M. Malina The purpose of this study was to evaluate secular change in the prevalence of overweight and obesity in a rural Zapotec Indian community in southern Mexico between 1968 and 2000. Cross-sectional surveys of children 6,13 years, adolescents 13,17 years, and adults 19 years of age and older resident in a rural community in Oaxaca were conducted in 1968/1971, 1978, and 2000. Individuals present in the 1968, 1978, and 2000 surveys provided a small longitudinal component. Height and weight were measured; the BMI was calculated. International criteria for overweight and obesity were used. Overweight and obesity were virtually absent in school children 6,13 years in 1968 and 1978 and in adolescents in 1978. Small proportions of children (boys, 5%; girls, 8%) and adolescents (boys, 3%; girls, 15%) were overweight in 2000; two children (1%) and no adolescents were obese. Among adults, 7% of males and 19% of females were overweight and <1% of males and 4% of females were obese in 1971/1978, but 46% of males and 47% of females were overweight; and 5% of males and 14% of females were obese in 2000. The trends for children, adolescents, and adults were confirmed in the longitudinal subsamples. In conclusion, overweight and obesity are not presently a major problem in children and adolescents in this rural Zapotec community. Overweight, in particular, and to a lesser extent obesity have increased in prevalence among adults since the late 1970s. The results suggest adulthood as a critical period for onset of overweight and obesity in this sample. Am. J. Hum. Biol., 2007. © 2007 Wiley-Liss, Inc. [source] The prognosis of occupational contact dermatitis in 2004CONTACT DERMATITIS, Issue 5-6 2004Jennifer Cahill The prognosis of occupational contact dermatitis (OCD) takes into account the extent of healing, effect on quality of life and employment, and financial costs for both the individual and the wider community. We reviewed 15 studies published between 1958 and 2002, reporting the complete clearance of dermatitis (range of 18,72%). 9 of the 15 studies reported a clearance rate of between 18 and 40%. Improvement was reported as an outcome in 3 studies between 1991 and 2002 (range of 70,84%). A number of common variables were identified as of possible influence. These include age, sex, atopy, patient knowledge, disease aetiology, duration of symptoms and job change; clinical, financial and social issues are also described. All of these factors need to be considered when managing a patient with OCD. Improved patient knowledge and early diagnosis may be associated with improved prognosis, whereas job change does not make a significant difference. Some patients will develop persistent post-occupational dermatitis, which has important implications for prognosis and workers' compensation. Only a small proportion of eligible patients receive workers' compensation, even though financially supported healing time soon after diagnosis may result in an improved prognosis. [source] TRAJECTORIES OF CRIME AT PLACES: A LONGITUDINAL STUDY OF STREET SEGMENTS IN THE CITY OF SEATTLE,CRIMINOLOGY, Issue 2 2004DAVID WEISBURD Studies of crime at micro places have generally relied on cross-sectional data and reported the distributions of crime statistics over short periods of time. In this paper we use official crime data to examine the distribution of crime at street segments in Seattle, Washington, over a 14-year period. We go beyond prior research in two ways. First, we view crime trends at places over a much longer period than other studies that have examined micro places. Second, we use group-based trajectory analysis to uncover distinctive developmental trends in our data. Our findings support the view that micro places generally have stable concentrations of crime events over time. However, we also find that a relatively small proportion of places belong to groups with steeply rising or declining crime trajectories and that these places are primarily responsible for overall city trends in crime. These findings are particularly important given the more general decline in crime rates observed in Seattle and many other American cities in the 1990s. Our study suggests that the crime drop can be understood not as a general process that occurred across the city landscape but one that was generated in a relatively small group of micro places with strong declining crime trajectories over time. [source] Mice with mutations in Mahogunin ring finger-1 (Mgrn1) exhibit abnormal patterning of the left,right axisDEVELOPMENTAL DYNAMICS, Issue 12 2006Christina D. Cota Abstract Mahogunin Ring Finger 1 (Mgrn1) encodes a RING-containing protein with ubiquitin ligase activity that has been implicated in pigment-type switching. In addition to having dark fur, mice lacking MGRN1 develop adult-onset spongy degeneration of the central nervous system and have reduced embryonic viability. Observation of complete situs inversus in a small proportion of adult Mgrn1 mutant mice suggested that embryonic lethality resulted from congenital heart defects due to defective establishment and/or maintenance of the left,right (LR) axis. Here we report that Mgrn1 is expressed in a pattern consistent with a role in LR patterning during early development and that many Mgrn1 mutant embryos show abnormal expression of asymmetrically expressed genes involved in LR patterning. A range of complex heart defects was observed in 20,25% of mid-to-late gestation Mgrn1 mutant embryos and another 20% were dead. This finding was consistent with 46,60% mortality of mutants by weaning age. Our results indicate that Mgrn1 acts early in the LR signaling cascade and is likely to provide new insight into this developmental process as Nodal expression was uncoupled from expression of other Nodal-responsive genes in Mgrn1 mutant embryos. Our work identifies a novel role for MGRN1 in embryonic patterning and suggests that the ubiquitination of MGRN1 target genes is essential for the proper establishment and/or maintenance of the LR axis. Developmental Dynamics 235:3438,3447, 2006. © 2006 Wiley-Liss, Inc. [source] The role of sensorimotor impairments in dyslexia: a multiple case study of dyslexic childrenDEVELOPMENTAL SCIENCE, Issue 3 2006Sarah White This study attempts to investigate the role of sensorimotor impairments in the reading disability that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched for age and non-verbal intelligence, on tasks assessing literacy as well as phonological, visual, auditory and motor abilities. The dyslexic group as a whole were significantly impaired on phonological, but not sensorimotor, tasks. Analysis of individual data suggests that the most common impairments were on phonological and visual stress tasks and the vast majority of dyslexics had one of these two impairments. Furthermore, phonological skill was able to account for variation in literacy skill, to the exclusion of all sensorimotor factors, while neither auditory nor motor skill predicted any variance in phonological skill. Visual stress seems to account for a small proportion of dyslexics, independently of the commonly reported phonological deficit. However, there is little evidence for a causal role of auditory, motor or other visual impairments. [source] Systematic review of methods to diagnose infection in foot ulcers in diabetesDIABETIC MEDICINE, Issue 4 2006S. O'Meara Abstract Aim, To undertake a systematic review of the diagnostic performance of clinical examination, sample acquisition and sample analysis in infected foot ulcers in diabetes. Methods, Nineteen electronic databases plus other sources were searched. To be included, studies had to fulfil the following criteria: (i) compare a method of clinical assessment, sample collection or sample analysis with a reference standard; (ii) recruit diabetic individuals with foot ulcers; (ii) present 2 × 2 diagnostic data. Studies were critically appraised using a 12-item checklist. Results Three eligible studies were identified, one each on clinical examination, sample collection and sample analysis. For all three, study groups were heterogeneous with respect to wound type and a small proportion of participants had foot ulcers due to diabetes. No studies identified an optimum reference standard. Other methodological problems included non-blind interpretation of tests and the time lag between index and reference tests. Individual signs or symptoms of infection did not prove to be useful tests when assessed against punch biopsy as the reference standard. The wound swab did not perform well when assessed against tissue biopsy. Semiquantitative analysis of wound swab might be a useful alternative to quantitative analysis. The limitations of these findings and their impact on recommendations from relevant clinical guidelines are discussed. Conclusion, Given the importance of this topic, it is surprising that only three eligible studies were identified. It was not possible to describe the optimal methods of diagnosing infection in diabetic patients with foot ulceration from the evidence identified in this systematic review. Diabet. Med. 23, 341,347 (2006) [source] HOPE for patients with Type 2 diabetes: an application of the findings of the MICRO-HOPE substudy in a British hospital diabetes clinicDIABETIC MEDICINE, Issue 8 2001S. C. Jones Abstract Aims, The MICRO-HOPE substudy demonstrated that when ramipril treatment was added to people with Type 2 diabetes and additional cardiovascular risk factors cardiovascular events were reduced by 25% in 4.5 years. We wished to determine the proportion of people with Type 2 diabetes and additional cardiovascular risk factors registered with a hospital diabetes service. Methods, Non-proteinuric people (n = 1370) with Type 2 diabetes identified on our diabetes register were subject to analysis. Anticipated reductions in cardiovascular events due to ramipril treatment were based on reductions observed in the MICRO-HOPE substudy. Results, Non-proteinuric people (n = 1075 (78%)) with Type 2 diabetes had at least one additional cardiovascular risk factor. Twenty-nine percent were already taking an angiotensin-converting enzyme inhibitor. The remaining 764 patients were similar to ramipril-treated participants in the MICRO-HOPE substudy. Treatment with ramipril for 4.5 years would be anticipated to reduce cardiovascular deaths by 26, revascularization procedures by 19 and admissions for myocardial infarction and stroke by 18 and 26, respectively. Conclusions, Of non-proteinuric people with Type 2 diabetes, 78% have additional cardiovascular risk factors. Only a small proportion currently receive treatment with an angiotensin-converting enzyme inhibitor. The incidence of cardiovascular events could be reduced if more patients were treated with ramipril and other cardiovascular risk factors were addressed. Diabet. Med. 18, 667,670 (2001) [source] Introduced plants of the invasive Solidago gigantea (Asteraceae) are larger and grow denser than conspecifics in the native rangeDIVERSITY AND DISTRIBUTIONS, Issue 1 2004Gabi Jakobs ABSTRACT Introduced plant species that became successful invaders appear often more vigorous and taller than their conspecifics in the native range. Reasons postulated to explain this better performance in the introduced range include more favourable environmental conditions and release from natural enemies and pathogens. According to the Evolution of Increased Competitive Ability hypothesis (EICA hypothesis) there is a trade-off between investment into defence against herbivores and pathogens, and investment into a stronger competitive ability. In this study, we conducted field surveys to investigate whether populations of the invasive perennial Solidago gigantea Ait (Asteraceae) differ with respect to growth and size in the native and introduced range, respectively. We assessed size and morphological variation of 46 populations in the native North American range and 45 populations in the introduced European range. Despite considerable variation between populations within continents, there were pronounced differences between continents. The average population size, density and total plant biomass were larger in European than in American populations. Climatic differences and latitude explained only a small proportion of the total variation between the two continents. The results show that introduced plants can be very distinct in their growth form and size from conspecifics in the native range. The apparently better performance of this invasive species in Europe may be the result of changed selection pressures, as implied by the EICA hypothesis. [source] The use of drug detection dogs in Sydney, AustraliaDRUG AND ALCOHOL REVIEW, Issue 6 2009MATTHEW DUNN Abstract Introduction and Aims. At present there is little research into the use of drug detection dogs. The present study sought to explore the use of detection dogs in Sydney, Australia, utilising multiple data sources. Design and Methods. Data were taken from interviews with 100 regular ecstasy users and 20 key experts as part of the 2006 New South Wales arm of the Ecstasy and Related Drugs Reporting System, and secondary data sources. Results. The majority of regular ecstasy users reported taking some form of precaution if made aware that dogs would be at an event they were attending. A small proportion of the sample reported consuming their drugs when coming into contact with detection dogs. One group of key experts viewed the use of detection dogs as useful; one group disliked the use of detection dogs though cooperated with law enforcement when dogs were used; and one group considered that detection dogs contribute to greater harm. Secondary data sources further suggested that the use of detection dogs do not significantly assist police in identifying and apprehending drug suppliers. Discussion and Conclusions. The present study suggests that regular ecstasy users do not see detection dogs as an obstacle to their drug use. Future research is necessary to explore in greater depth the experiences that drug users have with detection dogs; the effect detection dogs may have on deterring drug consumption; whether encounters with detection dogs contribute to drug-related harm; and the cost,benefit analysis of this law enforcement exercise. [Dunn M, Degenhardt L. The use of drug detection dogs in Sydney, Australia. Drug Alcohol Rev 2009] [source] Edaphic niche differentiation among Polybotrya ferns in western Amazonia: implications for coexistence and speciationECOGRAPHY, Issue 3 2006Hanna TuomistoArticle first published online: 22 FEB 200 To study the degree of edaphic specialization in Amazonian plants, the distribution patterns of seven species of Polybotrya ferns were studied in 109 sites in a climatically uniform area of northwestern Amazonia (Colombia, Ecuador and northern Peru). The two most abundant species of Polybotrya were found in about two-thirds of the sites with almost 7000 individuals each, the rarest species occurred in just one site with 40 individuals. Each of the seven species appeared to have a unique realised niche, when niche dimensions were defined by gradients in soil texture, soil cation content, and inundation. The species also differed in how broadly or narrowly they were distributed along each gradient. Some species were practically never found in the same sites, whereas others co-occurred with a high frequency, in spite of showing clearly different abundance patterns among sites. A single site only contains a small part of the edaphic variation present in the landscape, and a small proportion of any species' niche space, so broad-scale studies are needed to adequately describe and compare species' niches and to assess to what degree niche differences promote species coexistence. The distribution patterns in Polybotrya are consistent with, but do not prove, that ecological speciation may have been important in the radiation of the genus. If such a pattern is found to be common in other Amazonian plants, this would indicate that each evolutionary lineage has adapted to the available habitats largely independently of the others. [source] Effects of plant diversity, plant productivity and habitat parameters on arthropod abundance in montane European grasslandsECOGRAPHY, Issue 4 2005Jörg Perner Arthropod abundance has been hypothesized to be correlated with plant diversity but the results of previous studies have been equivocal. In contrast, plant productivity, vegetation structure, abiotic site conditions, and the physical disturbance of habitats, are factors that interact with plant diversity, and that have been shown to influence arthropod abundance. We studied the combined effect of plant species diversity, productivity and site characteristics on arthropod abundance in 71 managed grasslands in central Germany using multivariate statistics. For each site we determined plant species cover, plant community biomass (productivity), macro- and micronutrients in the soil, and characterized the location of sites with respect to orographic parameters as well as the current and historic management regimes. Arthropods were sampled using a suction sampler and classified a priori into functional groups (FGs). We found that arthropod abundance was not correlated with plant species richness, effective diversity or Camargo's evenness, even when influences of environmental variables were taken into account. In contrast, plant community composition was highly correlated with arthropod abundances. Plant community productivity influenced arthropod abundance but explained only a small proportion of the variance. The abundances of the different arthropod FGs were influenced differentially by agricultural management, soil characteristics, vegetation structure and by interactions between different FGs of arthropods. Herbivores, carnivores and detritivores reacted differently to variation in environmental variables in a manner consistent with their feeding mode. Our results show that in natural grassland systems arthropod abundance is not a simple function of plant species richness, and they emphasize the important role of plant community composition for the abundance patterns of the arthropod assemblages. [source] Is the matrix a sea?ECOLOGICAL ENTOMOLOGY, Issue 1 2005Habitat specificity in a naturally fragmented landscape Abstract., 1. Metapopulation and island biogeography theory assume that landscapes consist of habitat patches set in a matrix of non-habitat. If only a small proportion of species conform to the patch,matrix assumptions then metapopulation theory may only describe special cases rather than being of more general ecological importance. 2. As an initial step towards understanding the prevalence of metapopulation dynamics in a naturally fragmented landscape, the distribution of beetle species in three replicates of three habitat types was examined, including rainforest and eucalypt forest (the habitat patches), and buttongrass sedgeland (the matrix), in south-west Tasmania, Australia. 3. Ordination methods indicated that the buttongrass fauna was extremely divergent from the fauna of forested habitats. Permutation tests showed that the abundance of 13 of 17 commonly captured species varied significantly among habitats, with eight species confined to eucalypts or rainforest, and three species found only in buttongrass. Approximately 60% of species were confined to forested habitat implying that metapopulation theory has the potential to be very important in the forest,buttongrass landscape. 4. Although floristically the rainforest and eucalypts were extremely distinct, the beetle faunas from eucalypts and rainforests overlapped substantially. Therefore rainforest patches connected by eucalypt forest represent continuous habitat for most species. 5. Other studies report a wide range of values for the proportion of patch-specific species in fragmented landscapes. Understanding the environmental or historical conditions under which a high proportion of species become patch specialists would help to identify where spatial dynamic theory may be especially applicable, and where habitat loss and fragmentation poses the greatest threat to biodiversity. [source] Test,re-test reliability of DSM-IV adopted criteria for 3,4-methylenedioxymethamphetamine (MDMA) abuse and dependence: a cross-national studyADDICTION, Issue 10 2009Linda B. Cottler ABSTRACT Aims This study evaluated the prevalence and reliability of DSM-IV adopted criteria for 3,4-methylenedioxymethamphetamine (MDMA) abuse and dependence with a purpose to determine whether it is best conceptualized within the category of hallucinogens, amphetamines or its own category. Design Test,re-test study. Participants MDMA users (life-time use >5 times) were recruited in St Louis, Miami and Sydney (n = 593). The median life-time MDMA consumption was 50 pills at the baseline. Measurements The computerized Substance Abuse Module for Club Drug (CD-SAM) was used to assess MDMA abuse and dependence. The Discrepancy Interview Protocol (DIP) was used to determine the reasons for the discrepant responses between the two interviews. Reliability of diagnoses, individual diagnostic criteria and withdrawal symptoms was examined using the kappa coefficient (,). Findings For baseline data, 15% and 59% met MDMA abuse and dependence, respectively. Substantial test,re-test reliability of the diagnoses was observed consistently across cities (, = 0.69). ,Continued use despite knowledge of physical/psychological problems' (87%) and ,withdrawal' (68%) were the two most prevalent dependence criteria. ,Physically hazardous use' was the most prevalent abuse criterion. Six dependence criteria and all abuse criteria were reported reliably across cities (,: 0.53,0.77). Seventeen of 19 withdrawal symptoms showed consistency in the reliability across cities. The most commonly reported reason for discrepant responses was ,interpretation of question changed'. Only a small proportion of the total discrepancies were attributed to lying or social desirability. Conclusion The adopted DSM-IV diagnostic classification for MDMA abuse and dependence was moderately reliable across cities. Findings on MDMA withdrawal support the argument that MDMA should be separated from other hallucinogens in DSM. [source] Selection of hibernation sites by Anthonomus pomorum: preferences and ecological consequencesENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2000St. Toepfer Abstract The apple blossom weevil, Anthonomus pomorum (L.) (Coleoptera: Curculionidae), has a long period of aestivo-hibernation in the adult stage lasting from summer to early spring of the following year. Potential hibernation sites within an apple orchard consist of high-stem rough-bark trees or dwarf smooth-bark trees. Field release-recapture experiments in 2 consecutive years showed that 64 and 47% of the weevils remained in the vicinity of the release sites in an area of high-stem trees and dwarf trees, respectively. The dispersing weevils moved over an average distance of 5.5 m in the dwarf tree area, as compared to 3.8 m in the high-stem tree area. The prevalent direction of dispersal was along tree rows in both areas. Some weevils displayed, after release in mid-July, a directional dispersal to the adjacent forests. Others, released in the dwarf tree area, dispersed towards the area of high-stem rough-bark apple trees. Experiments simulating various hibernation sites demonstrated that the litter of dry leaves was the most preferred overwintering shelter, yielding a relatively high survival rate. Branches with rough bark ranked second, while branches with smooth bark, grass and pure soil were not favourable for overwintering. Flight tendency in newly emerged weevils of summer generation was significantly higher in June/July than in August/September. This corresponds to the dispersal behaviour in the field. The timing of spring colonisation of apple trees was similar for weevils overwintering within the orchard and for those from outside. These results suggest that modern, dwarf apple orchards offer unfavourable conditions for overwintering, but that the relatively small proportion of weevils which manage to reach the adjacent forests find optimal hibernation sites there. [source] Prevalence of Active Epilepsy and Health-Related Quality of Life among Adults with Self-Reported Epilepsy in California: California Health Interview Survey, 2003EPILEPSIA, Issue 10 2007Rosemarie Kobau Summary:,Purpose: To examine the prevalence of self-reported epilepsy and active epilepsy, associated burden of impaired health-related quality of life, risk factors, and access to care in adults with self-reported epilepsy, and those classified as having active epilepsy with and without recent seizures. Methods: We analyzed data from adults aged ,18 years (n = 41,494) who participated in the 2003 California Health Interview Survey (CHIS). Results: In California, 1.2% of adults reported ever being told they had epilepsy or seizure disorder, and 0.7% were classified as having active epilepsy. About three-fourths of adults with active epilepsy with recent seizures reported fair or poor health status. Adults with active epilepsy with recent seizures reported almost two weeks of poor physical or mental health and activity limitation days compared with two to 4 days per month in those without epilepsy. Among adults with active epilepsy and recent seizures, about one-quarter reported not taking any medicine to control their seizure disorder or epilepsy. About one-third reported physical disability/unable to work compared to a small proportion of the general population. The majority of adults with active epilepsy reported having a regular source of medical care. Conclusion: Our findings highlight the burden of epilepsy among adults in California. CHIS serves as a model demonstrating the value of including questions about epilepsy on public health surveillance systems to ascertain the burden of the disorder and to guide intervention research and public policy to improve HRQOL in people with epilepsy. [source] An Epidemiologic Study of Closed Emergency Department Malpractice Claims in a National Database of Physician Malpractice InsurersACADEMIC EMERGENCY MEDICINE, Issue 5 2010Terrence W. Brown MD Abstract Objectives:, The objective was to perform an epidemiologic study of emergency department (ED) medical malpractice claims using data maintained by the Physician Insurers Association of America (PIAA), a trade association whose participating malpractice insurance carriers collectively insure over 60% of practicing physicians in the United States. Methods:, All closed malpractice claims in the PIAA database between 1985 and 2007, where an event in an ED was alleged to have caused injury to a patient 18 years of age or older, were retrospectively reviewed. Study outcomes were the frequency of claims and average indemnity payments associated with specific errors identified by the malpractice insurer, as well as associated health conditions, primary specialty groups, and injury severity. Indemnity payments include money paid to claimants as a result of settlement or court adjudication, and this financial obligation to compensate a claimant constitutes the insured's financial liability. These payments do not include the expenses associated with resolving a claim, such as attorneys' fees. The study examined claims by adjudicatory outcome, associated financial liability, and expenses of litigation. Adjudicatory outcome refers to the legal disposition of a claim as it makes its way into and through the court system and includes resolution of claims by formal verdict as well as by settlement. The study also investigated how the number of claims, average indemnity payments, paid-to-close ratios (the percentage of closed claims that resolved with a payment to the plaintiff), and litigation expenses have trended over the 23-year study period. Results:, The authors identified 11,529 claims arising from an event originating in an ED, representing over $664 million in total liability over the 23-year study period. Emergency physicians (EPs) were the primary defendants in 19% of ED claims. The largest sources of error, as identified by the individual malpractice insurer, included errors in diagnosis (37%), followed by improper performance of a procedure (17%). In 18% of claims, no error could be identified by the insurer. Acute myocardial infarction (AMI; 5%), fractures (6%), and appendicitis (2%) were the health conditions associated with the highest number of claims. Over two-thirds of claims (70%) closed without payment to the claimant. Most claims that paid out did so through settlement (29%). Only 7% of claims were resolved by verdict, and 85% of those were in favor of the clinician. Over time, the average indemnity payments and expenses of litigation, adjusted for inflation, more than doubled, while both the total number of claims and number of paid claims decreased. Conclusions:, Emergency physicians were the primary defendants in a relatively small proportion of ED claims. The disease processes associated with the highest numbers of claims included AMI, appendicitis, and fractures. The largest share of overall indemnity was attributed to errors in the diagnostic process. The financial liability of medical malpractice in the ED is substantial, yet the vast majority of claims resolve in favor of the clinician. Efforts to mitigate risk in the ED should include the diverse clinical specialties who work in this complex environment, with attention to those health conditions and potential errors with the highest risk. ACADEMIC EMERGENCY MEDICINE 2010; 17:553,560 © 2010 by the Society for Academic Emergency Medicine [source] Autoantibodies in alcoholic liver diseaseADDICTION BIOLOGY, Issue 2 2000Ian G. McFarlane Despite many decades of research, the reasons why only a relatively small proportion of individuals who consume excessive quantities of alcohol develop clinically significant liver disease remain unknown. The association with features of autoimmune diseases, including hypergammaglobulinaemia, circulating autoantibodies, inheritance of certain immunogenetic (HLA) markers and response to corticosteroid therapy in some patients has led to a persistent impression that altered immune regulation with a relative loss of self-tolerance underlies susceptibility to the development of the more severe forms of alcoholic liver disease (alcoholic hepatitis and/or cirrhosis). However, review of the data from the numerous studies that have been conducted over the past 30 years fails to reveal sufficiently convincing evidence that autoimmunity plays a primary role in alcohol-related liver damage. In particular, most of the wide range of circulating autoantibodies that have been reported in patients are found mainly at low titres, are not confined to those with severe liver injury, and are probably more likely to be a response to the hepatic insult than causally related to liver damage. Additionally, an association with various HLA phenotypes has not been confirmed by meta-analysis. Interpretation is complicated by evidence that alcohol may have direct effects on some components of the immune system but, if there is an immunogenetic basis for alcoholic liver disease, the present evidence suggests that this might be related more to cytokine gene polymorphisms than to a predisposition to autoimmunity per se. [source] Transcranial magnetic stimulation of the human frontal eye field facilitates visual awarenessEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2003Marie-Hélène Grosbras Abstract What are the brain mechanisms allowing a stimulus to enter our awareness? Some theories suggest that this process engages resources overlapping with those required for action control, but experimental support for these ideas is still required. Here, we investigated whether the human frontal eye field (FEF), an area known to control eye movements, is involved in visual awareness. Volunteers participated in a backward masking task in which they were able to detect a target in a small proportion of trials. We observed that a single pulse of transcranial magnetic stimulation applied over the FEF shortly before the target's onset facilitated visual sensitivity; subjects were able to detect an otherwise subliminal object. These results show that modulating the neuronal activity of the FEF can enhance visual detection, thereby yielding new insights into the neural basis of visual awareness. [source] In search of stable soil organic carbon fractions: a comparison of methods applied to soils labelled with 14C for 40 days or 40 yearsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2008S. Bruun Summary A reliable method for the isolation of a stable fraction of soil organic carbon (SOC) would be very helpful for improving our understanding of the mechanisms responsible for stabilization of SOC and the dynamics of SOC turnover. We tested acid hydrolysis, physical fractionation (particle density/size), photo-oxidation, treatment with chemical oxidants (NaOCl and NaS2O8) and thermal treatment on two soils incubated with 14C-labelled barley straw for either 40 days or 40 years. Different intensities of the treatments were included. Acid hydrolysis, photo-oxidation and treatment with a chemical oxidant consistently removed more 40-year-old C than 40-day-old C, which suggests that the isolated fractions contained a large proportion of material with a relatively rapid turnover. The clay + silt associated SOC fraction contained a small proportion of 40-day-old C and a large proportion of 40-year-old C. This is consistent with a SOC fraction with medium turnover. The thermal treatment removed more 40-year-old C than 40-day-old C. At 400°C there was still a small proportion of the 40-year-old C remaining, whereas almost all the 40-day-old C was removed. This is consistent with a stable SOC fraction. However, because only 2,3% of the C remained after this treatment, the isolated SOC fraction may be of little quantitative importance. Furthermore, the thermally resistant fraction is likely to be heavily altered by the treatment, and therefore unsuitable for further studies of the chemical nature of stable SOC. [source] INTRODUCING DESIRABLE TRANSGENES INTO INSECT POPULATIONS USING Y-LINKED MEIOTIC DRIVE,A THEORETICAL ASSESSMENTEVOLUTION, Issue 4 2007Yunxin Huang The use of genetic drive mechanisms to replace native mosquito genotypes with individuals bearing antipathogen transgenes is a potential strategy for repressing insect transmission of human diseases such as malaria and dengue. Antipathogen transgenes have been developed and tested, but efficient gene drive mechanisms are lacking. Here we theoretically assess the feasibility of introducing antipathogen genes into wild Aedes aegypti populations by using a naturally occurring meiotic drive system. We consider the release of males having both a Y-linked meiotic drive gene and an X-linked drive-insensitive response allele to which an antipathogen gene is linked. We use mathematical models and computer simulations to determine how the post-introduction dynamics of the antipathogen gene are affected by specific genetic characteristics of the system. The results show that when the natural population is uniformly sensitive to the meiotic drive gene, the antipathogen gene may be driven close to fixation if the fitness costs of the drive gene, the insensitive response allele, and the antipathogen gene are low. However, when the natural population has a small proportion of an X-linked insensitive response allele or an autosomal gene that strongly reduces the effect of the drive gene, the antipathogen gene does not spread if it has an associated fitness cost. Our modeling results provide a theoretical foundation for further experimental tests. [source] Surface nucleolin participates in both the binding and endocytosis of lactoferrin in target cellsFEBS JOURNAL, Issue 2 2004Dominique Legrand Lactoferrin (Lf), a multifunctional molecule present in mammalian secretions and blood, plays important roles in host defense and cancer. Indeed, Lf has been reported to inhibit the proliferation of cancerous mammary gland epithelial cells and manifest a potent antiviral activity against human immunodeficiency virus and human cytomegalovirus. The Lf-binding sites on the cell surface appear to be proteoglycans and other as yet undefined protein(s). Here, we isolated a Lf-binding 105 kDa molecular mass protein from cell extracts and identified it as human nucleolin. Medium,affinity interactions (, 240 nm) between Lf and purified nucleolin were further illustrated by surface plasmon resonance assays. The interaction of Lf with the cell surface-expressed nucleolin was then demonstrated through competitive binding studies between Lf and the anti-human immunodeficiency virus pseudopeptide, HB-19, which binds specifically surface-expressed nucleolin independently of proteoglycans. Interestingly, binding competition studies between HB-19 and various Lf derivatives in proteoglycan-deficient hamster cells suggested that the nucleolin-binding site is located in both the N- and C-terminal lobes of Lf, whereas the basic N-terminal region is dispensable. On intact cells, Lf co-localizes with surface nucleolin and together they become internalized through vesicles of the recycling/degradation pathway by an active process. Morever, a small proportion of Lf appears to translocate in the nucleus of cells. Finally, the observations that endocytosis of Lf is inhibited by the HB-19 pseudopeptide, and the lack of Lf endocytosis in proteoglycan-deficient cells despite Lf binding, point out that both nucleolin and proteoglycans are implicated in the mechanism of Lf endocytosis. [source] Food composition, habitat use and growth of stocked and native Arctic charr, Salvelinus alpinus, in Lake Muddusjärvi, FinlandFISHERIES MANAGEMENT & ECOLOGY, Issue 4 2002K. KAHILAINEN Habitat use, growth and food composition of native and stocked Arctic charr, Salvelinus alpinus (L.), were studied in the subarctic Lake Muddusjärvi, northern Finland, to investigate reasons for poor stocking success. Samples were collected with pelagic and epibenthic gill nets. Stocked and native charr occurred in similar epibethic habitats, whereas pelagic habitat was avoided. Native charr grew fast after shifting to piscivory. Growth rate of stocked charr was slow because only a small proportion of stocked fish became piscivorous during the first year after stocking. During the first lake year, stocked charr divided into slow-growing planktivores and fast-growing piscivores. Piscivorous stocked and native charr consumed only whitefish, Coregonus lavaretus (L.), as their prey. Small-sized (<10 cm) whitefish were preferred when shifting to piscivory. [source] The effects of dietary Microcystis aeruginosa and microcystin on the copepods of the upper San Francisco EstuaryFRESHWATER BIOLOGY, Issue 7 2010KEMAL A. GER Summary 1. Increasing blooms of Microcystis aeruginosa have unknown impacts on the copepods Eurytemora affinis and Pseudodiaptomus forbesi, which are the dominant zooplankters and key prey species for endangered larval fish in the upper San Francisco Estuary. 2. Laboratory feeding experiments were designed to measure the effect of Microcystis on copepod survival and to distinguish the effects of toxicity and nutrition. In a series of survival tests, copepods were fed a mixed diet of algae plus one of two strains of Microcystis, either producing (MC+) or lacking microcystin (MC,). 3. Microcystis significantly reduced survival even when it was a small proportion of the diet, indicating that toxicity was the major cause of mortality. Contrary to expectation, however, the MC+ strain did not result in higher mortality, suggesting that non-MC metabolites of Microcystis can be toxic to copepods. 4. Across treatments, survival of P. forbesi was greater than that of E. affinis, although the two copepods responded differently to both the ratio and the strain of Microcystis in their food. Survival of P. forbesi was greater on the MC+ strain and was inversely proportional to the ratio of dietary Microcystis (MC+ or MC,). In contrast, survival of E. affinis declined similarly across treatments and was not related to the proportion or strain of dietary Microcystis. Results indicate that the copepod P. forbesi can coexist with Microcystis while the other copepod E. affinis cannot. 5. Regardless of species, dietary Microcystis caused significant mortality to copepods, and it may cause adverse impacts to the potentially food-limited zooplankton community of the San Francisco Estuary. These impacts may not be related to the cellular MC concentration because Microcystis contains other metabolites that negatively affect copepods. [source] Calcium balance in Daphnia grown on diets differing in food quantity, phosphorus and calciumFRESHWATER BIOLOGY, Issue 11 2009XUE-JIA HE Summary 1.,The influences of dietary phosphorus (P) and food concentration on the calcium (Ca) balance in Daphnia magna were examined in this study at two different ambient Ca concentrations (0.5 and 10 mg Ca L,1). Daphnia were grown by feeding the young adults differentially under contrasting dietary P conditions [molar C : P ratio = c. 900 and c. 90 as low P (LP) and high P (HP), respectively], ambient Ca concentrations [0.5 mg and 10 mg Ca L,1 as low Ca (LCa) or high Ca (HCa), respectively] and food levels [0.15 or 1.5 mg C L,1 as low food (LF) or high food (HF), respectively] for 5 days. 2.,The specific Ca contents of daphniids (1.9,6.5% of dry weight,1) increased with increasing Ca concentration, food level and dietary P content, although the food level did not affect the Ca content in the HPHCa treatment. A radioactive tracer method showed that the food level did not affect the influx of Ca from the water under LP conditions, but the Ca influx under HP conditions doubled with a HF level. A LP condition also led to a decrease in Ca influx with a HF level. 3.,During the 3 days of efflux, generally only a small proportion of Ca (2.6,3.3%) was retained by the daphniids, but this retention increased (14,23%) under low ambient Ca concentrations and under P-limitation. Excretion was the most important pathway for Ca loss (accounting for 50,60% of body Ca), followed by moulting (20,47%), but the relative contribution of these two pathways (excretion and moulting) did not vary among all the different treatments. The absolute loss of Ca through excretion and moulting, on the contrary, differed with different ambient Ca concentrations and dietary P conditions. A HF level led to an increase in the loss rates in most cases. 4.,Our study strongly suggested that there is an interaction between an essential metal (Ca) and macronutrients (C and P) in freshwater crustaceans with HCa and P contents. The results imply that variation in environmental nutrient conditions may change the Ca budget in crustaceans and may affect the dynamics of Ca in the epilimnion of freshwaters. [source] Hydraulic lift in a neotropical savannaFUNCTIONAL ECOLOGY, Issue 5 2003M. Z. Moreira Summary 1We report hydraulic lift in the savanna vegetation of central Brazil (Cerrado). Both heat-pulse measurements and isotopic (deuterium) labelling were used to determine whether hydraulic lift occurred in two common species, and whether neighbouring small shrubs and trees were utilizing this water. 2Both techniques showed water uptake by tap-roots and reverse flow of water in lateral roots. Roots transferred hydraulically lifted water to the soil, and small shrubs and trees neighbouring the labelled individuals were labelled by deuterated water. 3Isotopic mass-balance equations and sap-flow measurements showed that water taken up by the central tap-root in each individual constituted only a small percentage of total flux of water through the treated plants. Mass-balance equations also indicated that small shrubs and trees neighbouring the treated plants utilized only a few thousandths of a per cent of the label. 4The small proportion of water uptake by the tap-root of these two species may be limiting hydraulic lift in this system, unless sinker roots descending from lateral roots contribute to hydraulic lift. [source] Coxibs: evolution of prescription's behaviour in FranceFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2007Julie Biga Abstract The aim of the present study was, first to characterize profiles of coxibs' prescribers [general practitioners (GPs) and rheumatologists] in 2002 in France and, secondly, to identify factors associated with modification of this profile 1 year later. All GPs and rheumatologists from Midi-Pyrenees, Aquitaine, Languedoc-Roussillon and Pays de Loire areas (South of France: 11 050 000 inhabitants) were included in the study. For each practitioner, we used data concerning all non-steroidal anti-inflammatory drugs (NSAIDs) including coxibs reimbursed during period 1 (P1; January,March 2002) and period 2 (P2; January,March 2003). The ratio between the number of coxibs' prescriptions and the total number of NSAIDs' prescriptions (including coxibs) was used to define the two profiles of prescribers, one with a low level of coxibs' prescriptions and another one with a high level of coxibs' prescriptions. Characteristics of practitioners and characteristics of their practices were compared according to this profile. In the second step, we investigated the characteristics (of practitioners and practices) associated with an increase in the level of coxibs' prescriptions in P2 for practitioners with a low level of coxibs' prescriptions in P1. Results are expressed as odds ratio with their 95% confidence intervals. A positive statistical link was found between a high level of coxibs' prescriptions, the speciality of rheumatologist or extra costs for consultation. In contrast, a negative association was observed with female gender or age below 44 years. No relationship was found with the status of referent. Concerning practices' characteristics of practitioners, there was a positive statistical link between a high ratio of coxibs' prescriptions and high co-prescriptions of gastroprotective agents and a negative association with a high number of acts, a high proportion of patients with chronic disabling diseases (CDD) or a high number of patients between 15 and 64 years. There was no statistical link with proportion of patients covered by Universal Medical Coverage (UMC) or aged more than 65 years. Among the factors involved in the increase in the ratio (between P1 and P2), no relationship was found with practitioners' characteristics. In contrast, some factors related to practices (level of gastroprotective co-prescriptions, number of acts, number of CDD patients) were related to a change in coxibs' prescriptions between P1 and P2. This study allowed to discuss some relationships between coxibs' prescription and practitioners' (age, gender, medical speciality or extra costs for consultation) or practices' (level of medical practice, patients' age, number of CDD patients or level of gastroprotective prescriptions) characteristics. In contrast, some other factors like the referent status or the number of patients with UMC are not related. Physicians, initially low prescribers of coxibs and increasing their coxibs' prescriptions during the period of our study, were those with a high level of gastroprotective prescriptions, a low number of acts or a small proportion of CDD patients. [source] Limits of fine-mapping a quantitative traitGENETIC EPIDEMIOLOGY, Issue 2 2003Larry D. Atwood Abstract Once a significant linkage is found, an important goal is reducing the error in the estimated location of the linked locus. A common approach to reducing location error, called fine-mapping, is the genotyping of additional markers in the linked region to increase the genetic information. The utility of fine-mapping for quantitative trait linkage analysis is largely unknown. To explore this issue, we performed a fine-mapping simulation in which the region containing a significant linkage at a 10-centiMorgan (cM) resolution was fine-mapped at 2, 1, and 0.5 cM. We simulated six quantitative trait models in which the proportion of variation due to the quantitative trait locus (QTL) ranged from 0.20,0.90. We used four sampling designs that were all combinations of 100 and 200 families of sizes 5 and 7. Variance components linkage analysis (Genehunter) was performed until 1,000 replicates were found with a maximum lodscore greater than 3.0. For each of these 1,000 replications, we repeated the linkage analysis three times: once for each of the fine-map resolutions. For the most realistic model, reduction in the average location error ranged from 3,15% for 2-cM fine-mapping and from 3,18% for 1-cM fine-mapping, depending on the number of families and family size. Fine-mapping at 0.5 cM did not differ from the 1-cM results. Thus, if the QTL accounts for a small proportion of the variation, as is the case for realistic traits, fine-mapping has little value. Genet Epidemiol 24:99,106, 2003. © 2003 Wiley-Liss, Inc. [source] Antimicrobial Gallium-Doped Phosphate-Based Glasses,ADVANCED FUNCTIONAL MATERIALS, Issue 5 2008Sabeel P. Valappil Abstract Novel quaternary gallium-doped phosphate-based glasses (1, 3, and 5 mol % Ga2O3) were synthesized using a conventional melt quenching technique. The bactericidal activities of the glasses were tested against both Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Clostridium difficile) bacteria. Results of the solubility and ion release studies showed that these glass systems are unique for controlled delivery of Ga3+. 71Ga NMR measurements showed that the gallium is mostly octahedrally coordinated by oxygen atoms, whilst FTIR spectroscopy provided evidence for the presence of a small proportion of tetrahedral gallium in the samples with the highest gallium content. FTIR and Raman spectra also afford an insight into the correlation between the structure and the observed dissolution behavior via an understanding of the atomic-scale network bonding characteristics. The results confirmed that the net bactericidal effect was due to Ga3+, and a concentration as low as 1 mol % Ga2O3 was sufficient to mount a potent antibacterial effect. The dearth of new antibiotics in development makes Ga3+ a potentially promising new therapeutic agent for pathogenic bacteria including MRSA and C. difficile. [source] In vivo investigation of CD133 as a putative marker of cancer stem cells in Hep-2 cell lineHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2009Xu Dong Wei PhD Abstract Background Mounting evidence suggests that most tumors consist of a heterogeneous population of cells with a subset population that has the exclusive tumorigenic ability. They are called cancer stem cells (CSCs). CSCs can self-renew to generate additional CSCs and also differentiate to generate phenotypically diverse cancer cells with limited proliferative potential. They have been identified in a variety of tumors. In this study, we identify the marker of CSCs in the established human laryngeal tumor Hep-2 cell line in vivo. Our in vitro experiment shown as CD133, a 5-transmembrane glycoprotein expressed in Hep-2 cell line. CD133 was supposed as a candidate of CSC in laryngeal carcinoma. In this study, the expression of CD133 was detected in a Hep-2 cell line. Applying the magnetic cell sorting (MACS) technology, we reported the results of purifying CD133 positive cells from a Hep-2 cell line. Three-type cells' tumor-forming ability was examined in vivo to identify the marker of CSCs in Hep-2 cell line. Methods CD133 was selected as a putative marker of CSC in laryngeal carcinoma, Hep-2 cell lines. Flow cytometry was used to detect the expression of CD133 in the Hep-2 cell line. Immunomagnetic beads were applied to purify CD133-positive cells. CD133(+), CD133(,) tumor cells, and unsorted Hep-2 cells were injected into severe combined immune deficiency (SCID) mice individually to observe tumor-forming ability. Results Only a small proportion (3.15% ± 0.83%) of cells in the Hep-2 cell line express the CD133 marker. In comparison with CD133(,) tumor cells and unsorted cells, CD133(+) cells possess a marked capacity for tumor formation in vivo (p <.05). Conclusion CD133 is 1 of the markers for CSCs in human laryngeal tumors of the Hep-2 cell line. Work on the characterization of these cells provides a powerful tool to investigate the tumorigenic process in the larynx and to develop therapies targeting the CSC. © 2008 Wiley Periodicals, Inc. Head Neck, 2009 [source] | |||||||||||||||||||||||||||||||||||||||||||