Negative Impact (negative + impact)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Negative Impact

  • greater negative impact
  • potential negative impact
  • significant negative impact

  • Selected Abstracts

    Perceived Benefits and Negative Impact of Challenges Encountered in Caring for Young Adults with Intellectual Disabilities in the Transition to Adulthood

    Cher Rapanaro
    Background, This study investigated the perceived benefits and negative impact associated with stressful events and chronic caregiving demands encountered by parents caring for young adults with an intellectual disability in the period of transition to adulthood. Methods, A sample of 119 parents of young adults described these outcomes in a questionnaire, which were then analysed using qualitative content analysis. Results, Although parents identified a range of negative outcomes, they also reported positive outcomes (perceived benefits) in relation to stressful events and chronic demands encountered in this period, including personal growth and enhanced personal resources. Conclusions, The language of stress and burden often used to describe parents' experiences during the period of their son or daughter's transition to adulthood, needs to coexist with a language of fulfilment, growth and gain, as used by parents themselves. The implications of these findings, in relation to professional interaction with and support of parents in this period, are discussed. [source]

    Chronic and High Alcohol Consumption Has a Negative Impact on Sleep and Sleep-Associated Consolidation of Declarative Memory

    ALCOHOLISM, Issue 5 2009
    Klaus Junghanns
    Background., The importance of sleep for memory consolidation has become a major focus of research. While it is known that abstaining alcohol-dependent patients often have sleep disorders and that there is some cognitive impairment during early abstention a possible interaction of disturbed sleep with overnight memory consolidation has not been addressed in a study as yet. Methods., Twenty-four alcohol-dependent patients with a short abstention period (mean 21.9 ± 7.6 days) were compared with 12 patients with an abstention period of several months (115.7 ± 43.8 days). Groups did not differ with respect to daily alcohol consumption before treatment, duration of alcohol dependence, and age. Before sleep all patients learned a list of semantically associated word pairs and a face name association task to a fixed criterion (at least 60% of correct recall) and they performed a mirror tracing task. After a polysomnographically registered night the patients were tested for retention of the learned declarative material by cued recall and had to perform the mirror tracing task again. Results., The groups did not differ with respect to sleep parameters or sleep-associated memory consolidation. Across both groups the duration of alcohol dependence correlated negatively with the amount of non-REM sleep and recall in the face name association task correlated negatively with daily alcohol consumption before abstention. Among the longer-term abstainers the duration of abstention correlated with the amount of slow wave sleep. Conclusions., Our data support the hypothesis that chronic and high alcohol consumption negatively affects sleep and declarative memory consolidation during the first months of abstention. Between an abstention period of a few weeks and of several months no change in sleep parameters and nightly memory consolidation could be demonstrated, however. [source]

    Negative Impact of Metabolic Syndrome on the Responsiveness to Sildenafil in Japanese Men

    Takahiro Suetomi MD
    ABSTRACT Introduction., Several recent studies suggested that the prevalence of erectile dysfunction (ED) was higher in men with metabolic syndrome (MS). Aim., We analyzed the impact of MS on the responsiveness to sildenafil. Methods., A total of 133 ED patients were evaluated for the prevalence of MS and graded on severity of ED. MS was diagnosed according to the International Diabetes Federation (IDF) definition. The severity of ED was evaluated by the International Index of Erectile Function (IIEF) questionnaire. Hormonal parameters were measured for all patients, and the IIEF questionnaire was conducted after administration of eight tablets of 50-mg doses of sildenafil. If the scores to questions 3 and 4 of the IIEF were 4 or higher after administration, the patients were defined as responders to sildenafil. Main Outcome Measures., To clarify the negative impact of MS on the responsiveness to sildenafil. Results., The mean age of the patients was 56.9 years, and 25 patients were diagnosed with MS. The IIEF-erectile function score and the response rate for sildenafil decreased as the number of MS components increased. Logistic regression analysis showed that the presence of MS along with severity of ED and history of pelvic surgery were significant independent risk factors of nonresponse for sildenafil. The hazard ratio for the presence of MS was 3.30 (95% confidence interval [CI]: 1.17,9.73). No meaningful association was observed between total testosterone or free testosterone levels and MS in this population. Conclusion., We demonstrated the negative impact of MS on the responsiveness to sildenafil. Erectile function and response rate for sildenafil decreased as the number of MS components increased. Suetomi T, Kawai K, Hinotsu S, Joraku A, Oikawa T, Sekido N, Miyanaga N, Shimazui T, and Akaza H. Negative impact of metabolic syndrome on the responsiveness to sildenafil in Japanese men. J Sex Med 2008;5:1443,1450. [source]

    Academic Procrastination in Two Settings: Motivation Correlates, Behavioral Patterns, and Negative Impact of Procrastination in Canada and Singapore

    APPLIED PSYCHOLOGY, Issue 3 2010
    Robert M. Klassen
    Two studies are reported examining academic procrastination and motivation in 1,145 university students from Canada and Singapore. In Study 1, relationships between procrastination and motivation variables were found to be similar across contexts, with self-efficacy for self-regulated learning most strongly associated with procrastination in both contexts. In Study 2, patterns of procrastinating behavior and the negative impact of procrastination were examined and compared in Canadian and Singaporean undergraduates. Participants in both contexts reported writing to be the academic task most prone to procrastination. More Singaporeans than Canadians were classified as negative procrastinators (i.e. rated procrastination as a negative influence on academic functioning). In both contexts, negative procrastinators spent more time procrastinating than neutral procrastinators and displayed lower self-efficacy for self-regulated learning. On décrit deux recherches portant sur la motivation et la procrastination universitaire (tendance à remettre au lendemain) de 1145 étudiants du Canada et de Singapour. Dans la première étude, les relations entre la motivation et la procrastination sont apparues être analogues dans les deux pays, la variable la plus fortement associéà la procrastination étant l'auto-efficience pour l'apprentissage autorégulé. Dans la deuxième étude, les schémas comportementaux de procrastination et son impact négatif ont été analysés et comparés chez les étudiants de 1° cycle canadiens et singapouriens. Les sujets des deux pays ont mentionné la rédaction comme étant la tâche universitaire la plus soumise à la procrastination. Davantage de Singapouriens que de Canadiens été classés en procrastinateurs négatifs (c'est-à-dire que la procrastination est considérée comme étant un handicap pour les études). Dans les deux cas, les procrastinateurs négatifs gaspillaient plus de temps que les procrastinateurs neutres et manifestaient une moindre auto-efficience pour l'apprentissage autorégulé. [source]

    Negative impact of systemic catecholamine administration on hepatic blood perfusion after porcine liver transplantation

    Arianeb Mehrabi
    Catecholamines are often administered during and after liver transplantation (LTx) to support systemic perfusion and to increase organ oxygen supply. Some vasoactive agents can compromise visceral organ perfusion. We followed the hypothesis that the vasculature of transplanted livers presents with a higher sensitivity, which leads to an increased vulnerability for flow derangement after application of epinephrine (Epi) or norepinephrine (NorEpi). Hepatic macroperfusion and microperfusion during systemic Epi or NorEpi infusion were measured by Doppler flow and thermodiffusion probes in porcine native, denervated, and transplanted livers (n = 16 in each group). Epi or NorEpi were infused (n = 8 in each subgroup) in predefined dosages (low dose = 5 ,g/kg/minute and high dose = 10 ,g/kg/minute) over 240 minutes. Systemic cardiocirculatory parameters were monitored continuously. Hepatic perfusion data were compared between all groups at comparable time points and dosages. In all native, denervated, and transplanted liver groups, Epi and NorEpi induced an inconsistent rise of mean arterial pressure and heart rate shortly after onset of infusion in both dosages compared with baseline. No significant differences of cardiovascular parameters at comparable time points were observed. In native livers, Epi and NorEpi induced only temporary alterations of hepatic macrocirculation and microcirculation, which returned to baseline 2 hours after onset of infusion. No significant alterations of hepatic blood flow were detected after isolated surgical denervation of the liver. By contrast, transplanted livers showed a progressive decline of hepatic macrocirculation (33,75% reduction) and microcirculation (39,58% reduction) during catecholamine infusions in a dose-dependent fashion. Characteristics of liver blood flow impairment were comparable for both vasoactive agents. In conclusion, pronounced disturbances of hepatic macrocirculation and microcirculation were observed during systemic Epi and NorEpi infusion after LTx compared with native and denervated livers. Microcirculation disturbances after LTx might be explained by impairment of hepatic blood flow regulation caused by an increased sensitivity of hepatic vasculature after ischemia-reperfusion and by lengthening of vasopressor effects caused by reduced hepatocyte metabolism. Clinicians should be aware of this potentially hazardous effect. Therefore, application of catecholamines after clinical LTx should be indicated carefully. (Liver Transpl 2005;11:174,187.) [source]

    Negative Impact of Metabolic Syndrome on the Responsiveness to Sildenafil in Japanese Men

    Takahiro Suetomi MD
    ABSTRACT Introduction., Several recent studies suggested that the prevalence of erectile dysfunction (ED) was higher in men with metabolic syndrome (MS). Aim., We analyzed the impact of MS on the responsiveness to sildenafil. Methods., A total of 133 ED patients were evaluated for the prevalence of MS and graded on severity of ED. MS was diagnosed according to the International Diabetes Federation (IDF) definition. The severity of ED was evaluated by the International Index of Erectile Function (IIEF) questionnaire. Hormonal parameters were measured for all patients, and the IIEF questionnaire was conducted after administration of eight tablets of 50-mg doses of sildenafil. If the scores to questions 3 and 4 of the IIEF were 4 or higher after administration, the patients were defined as responders to sildenafil. Main Outcome Measures., To clarify the negative impact of MS on the responsiveness to sildenafil. Results., The mean age of the patients was 56.9 years, and 25 patients were diagnosed with MS. The IIEF-erectile function score and the response rate for sildenafil decreased as the number of MS components increased. Logistic regression analysis showed that the presence of MS along with severity of ED and history of pelvic surgery were significant independent risk factors of nonresponse for sildenafil. The hazard ratio for the presence of MS was 3.30 (95% confidence interval [CI]: 1.17,9.73). No meaningful association was observed between total testosterone or free testosterone levels and MS in this population. Conclusion., We demonstrated the negative impact of MS on the responsiveness to sildenafil. Erectile function and response rate for sildenafil decreased as the number of MS components increased. Suetomi T, Kawai K, Hinotsu S, Joraku A, Oikawa T, Sekido N, Miyanaga N, Shimazui T, and Akaza H. Negative impact of metabolic syndrome on the responsiveness to sildenafil in Japanese men. J Sex Med 2008;5:1443,1450. [source]

    Impact of the 1996 welfare reform on child and family well-being

    Kyunghee Lee
    This article examined the impact of the 1996 Welfare Reform, based on data from the National Longitudinal Survey of Youth. Using a sample of 1,681 single mothers living in poverty, this study compared the effects of economic well-being and home environment scores on their children during pre- and post-Welfare Reform years. Following the 1996 Welfare Reform, fewer mothers received cash payments, and those who did received lower payments, while more mothers worked at low-paying jobs. Negative impacts were more pronounced for less educated mothers. The effects of family income and home environment scores on children were different before and after the 1996 Welfare Reform. Maternal education moderated these associations. Instead of enforcing the current "work first" mandate, this research supports giving priority to maternal education to enhance child and family well-being in low-income families. © 2009 Wiley Periodicals, Inc. [source]

    Rural parents with urban children: social and economic implications of migration for the rural elderly in Thailand

    John Knodel
    Abstract The present study explores the social and economic consequences of the migration of adult children to urban areas for rural parents in Thailand. Attention is given to the circumstances under which such migration takes place, including the role parents play in the process and the extent to which the implications of migration for the parents are taken into consideration. The analysis relies primarily on open-ended interviews conducted in 2004 with older age parents with migrant children in four purposely selected rural communities that were studied ten years earlier. Our findings suggest that migration of children to urban areas contributes positively to the material well-being of their elderly parents who remain in rural areas. Negative impacts of migration on social support, defined in terms of maintaining contact and visits, have been attenuated by the advent of technological changes in communication and also by improvements in transportation. Phone contact, especially through mobile phones, is now pervasive, in sharp contrast to the situation ten years earlier when it was extremely rare. Much of the change in Thailand in terms of the relationships between rural parents and their geographically dispersed adult children is quite consistent with the concept of the ,modified extended family', a perspective that has become common in discussions regarding elderly parents in industrial and post-industrial societies but rarely applied to the situation of elderly parents in developing country settings. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Specification and detection of performance problems with ASL

    Michael Gerndt
    Abstract Performance analysis is an important step in tuning performance-critical applications. It is a cyclic process of measuring and analyzing performance data, driven by the programmer's hypotheses on potential performance problems. Currently this process is controlled manually by the programmer. The goal of the work described in this article is to automate the performance analysis process based on a formal specification of performance properties. One result of the APART project is the APART Specification Language (ASL) for the formal specification of performance properties. Performance bottlenecks can then be identified based on the specification, since bottlenecks are viewed as performance properties with a large negative impact. We also present the overall design and an initial evaluation of the Periscope system which utilizes ASL specifications to automatically search for performance bottlenecks in a distributed manner. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Discretionary Accounting Accruals, Managers' Incentives, and Audit Fees,

    Ferdinand A. Gul
    Abstract This paper examines the linkages between discretionary accruals (DAs), managerial share ownership, management compensation, and audit fees. It draws on the theory that managers of firms with high management ownership are likely to use DAs to communicate value-relevant information, while managers of firms with high accounting-based compensation are likely to use DAs opportunistically to manage earnings to improve their compensation. OLS regression results of 648 Australian firms show that (1) there is a positive association between DAs and audit fees; (2) managerial ownership negatively affects the positive relationship between DAs and audit fees; and (3) this negative impact is further found to be weaker for firms with high accounting-based management compensation. [source]


    In the context of dramatically increasing U.S. health-care costs, this paper contributes to an ongoing debate discussing proposals to replace the government's current policy of matching state Medicaid spending with a block grant system. State-level panel data analysis provides evidence that, ceteris paribus, increasing the federal matching formula has a negative impact on prenatal care. This aggregate result masks significant differences between high- and low-spending states and appears to be driven by the high-spending states thus implying that a 2-track approach to Medicaid funding may be more appropriate than the current system. (JEL I1, H7) [source]

    The atrium effect of website openness on the communication of corporate social responsibility

    Nuno Guimarães-Costa
    Abstract This paper applies the image of a Roman atrium to disclosure of CSR activities on company websites, through an examination of the website content of 19 large companies operating in Portugal. The analysis reveals a CSR discourse targeting stakeholders. What is stated is carefully chosen in order to mitigate potential reactions from offended stakeholders, these coming mostly from those areas where their negative impact could be more visible. We conclude that comparison with Roman atria can be made to the extent that (a) websites allow companies to suggest positive images about themselves, (b) their openness forces companies to adopt bi-focal messages where the target does not always coincide with the message's subject and (c) their visibility and accessibility induce companies to take a position on external events and to seek greater alignment between disclosure and action. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment. [source]

    Imidazoline-induced amplification of glucose- and carbachol-stimulated insulin release includes a marked suppression of islet nitric oxide generation in the mouse

    ACTA PHYSIOLOGICA, Issue 3 2009
    S. Meidute-Abaraviciene
    Abstract Aim:, The role of islet nitric oxide (NO) production in insulin-releasing mechanisms is unclear. We examined whether the beneficial effects of the imidazoline derivative RX 871024 (RX) on ,-cell function might be related to perturbations of islet NO production. Methods:, Experiments were performed with isolated islets or intact mice challenged with glucose or carbachol with or without RX treatment. Insulin was determined with radioimmunoassay, NO generation with high-performance liquid chromatography and expression of inducible NO synthase (iNOS) with confocal microscopy. Results:, RX treatment, in doses lacking effects on basal insulin, greatly amplified insulin release stimulated by the NO-generating secretagogues glucose and carbachol both in vitro and in vivo. RX also improved the glucose tolerance curve. Islets incubated at high glucose levels (20 mmol L,1) displayed increased NO production derived from both neuronal constitutive NO synthase (ncNOS) and iNOS. RX abrogated this glucose-induced NO production concomitant with amplification of insulin release. Confocal microscopy revealed abundant iNOS expression in , cells after incubation of islets at high but not low glucose levels. This was abolished after RX treatment. Similarly, islets cultured for 24 h at high glucose levels showed intense iNOS expression in , cells. This was abrogated with RX and followed by an amplified glucose-induced insulin release. Conclusion:, RX effectively counteracts the negative impact of ,-cell NO generation on insulin release stimulated by glucose and carbachol suggesting imidazoline compounds by virtue of NOS inhibitory properties being of potential therapeutic value for treatment of ,-cell dysfunction in hyperglycaemia and type 2 diabetes. [source]

    Urban Service Partnerships, ,Street-Level Bureaucrats' and Environmental Sanitation in Kumasi and Accra, Ghana: Coping with Organisational Change in the Public Bureaucracy

    Richard Crook
    This is an empirical case study of ,street-level' officials in a classic ,regulatory' public agency: the Environmental Health Department in Kumasi and Accra, Ghana, where privatisation and contracting-out of sanitary services have imposed new ways of working on Environmental Health Officers. Both internal and external organisational relationships are analysed to explain the extent to which these officers have adapted to more ,client-oriented' ways of working. Their positive organizational culture is credited with much of the positive results achieved, but was not sufficient to cope with the negative impact of politically protected privatisations on the officials' ability to enforce standards. Nor could it entirely overcome the deficiencies in training and incentive structures which should have accompanied the changes in service delivery. [source]

    Potential manipulation of endothelial progenitor cells in diabetes and its complications

    G. P. Fadini
    Diabetes mellitus increases cardiovascular risk through its negative impact on vascular endothelium. Although glucotoxicity and lipotoxicity account for endothelial cell damage, endothelial repair is also affected by diabetes. Endothelial progenitor cells (EPCs) are involved in the maintenance of endothelial homoeostasis and in the process of new vessel formation. For these reasons, EPCs are thought to have a protective impact within the cardiovascular system. In addition, EPCs appear to modulate the functioning of other organs, providing neurotropic signals and promoting repair of the glomerular endothelium. The exact mechanisms by which EPCs provide cardiovascular protection are unknown and the definition of EPCs is not standardized. Notwithstanding these limitations, the literature consistently indicates that EPCs are altered in type 1 and type 2 diabetes and in virtually all diabetic complications. Moreover, experimental models suggest that EPC-based therapies might help prevent or reverse the features of end-organ complications. This identifies EPCs as having a novel pathogenic role in diabetes and being a potential therapeutic target. Several ways of favourably modulating EPCs have been identified, including lifestyle intervention, commonly used medications and cell-based approaches. Herein, we provide a comprehensive overview of EPC pathophysiology and the potential for EPC modulation in diabetes. [source]

    Metabolic, endocrine and haemodynamic risk factors in the patient with peripheral arterial disease

    Jill J. F. Belch
    The morbidity and mortality associated with peripheral arterial disease (PAD) creates a huge burden in terms of costs both to the patient and to the health service. PAD is a deleterious and progressive condition that causes a marked increase in the risk of cardiovascular and cerebrovascular events. Further, PAD has a major negative impact on quality of life and mortality, and is associated with an increased risk of limb amputation. The clinical profile of patients at risk of PAD overlaps considerably with the known cardiovascular risk factors. These include, increasing age, smoking habit, diabetes, hypertension, dyslipidaemia, male sex and hyperhomocysteinaemia. For women, hormone replacement therapy appears to be associated with a reduced risk of PAD. Published PAD guidelines recommend aggressive management of risk factors, stressing the importance of lifestyle modification, antiplatelet agents, treating dyslipidaemia and diabetes. However, a large number of patients with PAD go undetected, either because they do not report their symptoms or because they are asymptomatic. It is therefore important to improve detection rates so that these patients can receive appropriate risk factor management. [source]

    Hub-and-spoke model for a 5-day structured patient education programme for people with Type 1 diabetes

    DIABETIC MEDICINE, Issue 9 2009
    H. Rogers
    Abstract Aims, Structured education programmes for people with Type 1 diabetes can deliver improved diabetes control (including reduced severe hypoglycaemia) and quality of life. They can be cost-effective but are resource intensive. We tested the ability to deliver an evidence-based 5-day programme in diabetes centres too small to deliver the courses. Methods, Specialist medical and nursing staff from three district general hospital diabetes services (the ,spokes') were trained in all aspects of the education programme, except those directly related to course delivery, by a larger centre (the ,hub'). The hub staff delivered the 5-day patient education courses, but all other patient education and management was managed locally. Diabetes control and quality of life were assessed at 1 year post-course. Results, In 63 patients with follow-up data, glycated haemoglobin (HbA1c) fell by 0.42 ± 1.0% (P = 0.001), with a greater fall in those with high HbA1c at baseline, and no mean weight gain. Emergency call-out for severe hypoglycaemia fell from 10 episodes in seven patients the year before to one episode in one patient (P = 0.03). Quality-of-life measures improved, with reduced negative impact of diabetes on diabetes-related quality of life (P < 0.00004) and ,present quality of life' improving (P < 0.001). Conclusions, The benefits of a 5-day structured education programme can be provided to patients with Type 1 diabetes attending centres without the resources to provide the teaching course itself, by a ,hub-and-spoke' methodology. [source]

    Sex differences in schizophrenia, a review of the literature

    Dr. Alice Leung M.D.
    Objective: To comprehensively and critically review the literature on gender differences in schizophrenia. Method: An initial search of MEDLINE abstracts (1966,1999) was conducted using the terms sex or gender and schizophrenia, followed by systematic search of all relevant articles. Results: Males have consistently an earlier onset, poorer premorbid functioning and different premorbid behavioral predictors. Males show more negative symptoms and cognitive deficits, with greater structural brain and neurophysiological abnormalities. Females display more affective symptoms, auditory hallucinations and persecutory delusions with more rapid and greater responsivity to antipsychotics in the pre-menopausal period but increased side effects. Course of illness is more favorable in females in the short- and middle-term, with less smoking and substance abuse. Families of males are more critical, and expressed emotion has a greater negative impact on males. There are no clear sex differences in family history, obstetric complications, minor physical anomalies and neurological soft signs. Conclusion: This review supports the presence of significant differences between schizophrenic males and females arising from the interplay of sex hormones, neurodevelopmental and psychosocial sex differences. [source]

    Influence of psychopathological changes on quality of life after laparoscopic fundoplication for the treatment of gastroesophageal reflux

    Á. Díaz de Liaño
    SUMMARY There are references in medical literature to the influence of psychopathological changes and their negative impact on the results of laparoscopic fundoplication. The objective of this study is to analyze the influence of psychological changes, as assessed by the General Health Questionnaire-28 (GHQ-28), on patients undergoing surgery for gastroesophageal reflux. This is a prospective study in a series of 103 consecutive patients (62 males and 41 females with a mean age of 40 years) undergoing laparoscopic fundoplication. In addition to functional studies, patients completed the SF-36, Gastrointestinal Quality of Life Index, and GHQ-28 before surgery. Functional tests and questionnaires were repeated 6 months after surgery. Patients were also questioned about their degree of satisfaction. Postoperative results of patients with a normal GHQ-28 and patients showing psychopathological changes as defined by the GHQ-28 questionnaire before surgery were compared. Overall, all patients experienced an improvement in their quality of life. Forty-one patients showed a pathological result in the preoperative GHQ-28 questionnaire. No differences were found in functional results and degree of satisfaction with surgery between patients with normal and pathological results in the preoperative GHQ-28 questionnaire. However, patients with a pathological result in the preoperative GHQ-28 had poorer results in all domains of the postoperative Gastrointestinal Quality of Life Index and SF36 quality of life questionnaires as compared to patients with a normal preoperative GHQ-28 questionnaire. Patients with pathological results in the preoperative GHQ-28 had poorer results in terms of postoperative quality of life despite having normal postoperative physiological studies; this decreased quality of life did not have an impact on the degree of satisfaction with surgery performed. The GHQ-28 does not therefore appear to serve as a predictor of postoperative satisfaction. [source]

    Dyslexia and psycho-social functioning: an exploratory study of the role of self-esteem and understanding

    DYSLEXIA, Issue 4 2009
    Melody M. Terras
    Abstract Individuals with dyslexia may have lower self-esteem and exhibit more emotional and behavioural difficulties than those without reading problems. However, the nature of any relationship between self-esteem and psychopathology remains unknown. This exploratory study assessed levels of self-esteem using the Self-Perception Profile for Children (Manual for the Self-Perception Profile for Children. University of Denver, CO: Denver; 1985) and psycho-social adjustment using the Strengths and Difficulties Questionnaire (J. Child Psychol. Psychiatry, 1997; 38: 581,586) and examined child and parent understanding, attitudes and the perceived impact of reading difficulties on daily life. Sixty-eight children assessed as dyslexic on the basis of discrepancy scores (mean age 11.2 years; 44 male), and their parents, participated. No global self-esteem deficit was found, but the mean score for both child and parent-rated scholastic competence was significantly lower than that of the general population. Rates of social, emotional and behavioural difficulties were significantly higher than in the general population and were correlated with self-esteem. For children who had high global self-worth, both children and their parents had more positive attitudes towards their reading difficulties and were less likely to perceive a negative impact on relationships. The association between academic self-esteem and emotional symptoms is consistent with the proposed link between dyslexia and internalizing difficulties. Good self-esteem and a good understanding of dyslexia may help children avoid some of these difficulties. Further research with larger more representative samples is necessary as understanding the factors that promote successful psycho-social adjustment is essential to the development of effective prevention and intervention strategies. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Is there a higher risk for herbivore outhreaks after cold mast years?

    ECOGRAPHY, Issue 6 2000
    An analysis of two plant/herbivore series from southern Norway
    Historical data on two plant-herbivore interactions from southern Norway were used to test the hypothesis that the degree of herbivore outbreaks in post-mast years is negatively related to summer temperatures in the mast year, because plants are more depressed after a high seed production if temperatures and thus the photosynthetic activity is low. The plant species were the sessile oak Quercus petraea and the bilberry Vaceinium myrtillus. For the former species post-mast years were identified from reports given by the local forest authorities for the period 1930,48, and from acorn export curves for the period 1949,98, For the latter species, post-mast years were identified mainly from bilberry export curves for the period 1920,31, from game reports for the period 1932,78. and from diary notes for the period 1979,87. The herbivore species used were the green oak leaf roller moth Tortrix viridana and the capercaillie Tetrao urogallus. Eight moth outbreaks on oak forests were reported by the forest authorities in the period 1930,98, and they all started in a post-mast year of the sessile oak. There were however also eleven post-mast years without moth outbreaks. According to game reports, observations and autumn counts, all increases in the autumn population size of capercaillie during 1920 88 occurred in or after a year with high bilberry production. Among i8 post-mast years, there were seven with strong increase, seven with slight or moderate increase, and four with no increase. For both herbivore species, post-mast years with marked population increases had significantly lower summer temperatures in the preceding (mast) year than had post-mast years with no or slight increases. For moth populations there also was a negative effect of high temperatures in April, possibly because moth eggs tend to hatch too early relative lo budburst if spring temperatures are high. For the capercaillie, high amount of precipitation in June , July seemed to have some negative impact on the autumn population sizes, as also found in previous studies. [source]

    Direct and indirect effects of the introduced toad Bufo marinus (Anura: Bufonidae) on populations of native anuran larvae in Australia

    ECOGRAPHY, Issue 3 2000
    Michael R. Crossland
    Introduced species are frequently believed to have adverse effects on native biota and ecosystems. However, much of our knowledge of the ecological impacts of introduced species is anecdotal, and the mechanisms controlling these effects are often poorly understood. I used replicated artificial pond experiments to investigate the impact of eggs and hatchlings of the introduced toad Bufo marinus on populations of native anuran larvae (Limnodynastes ornatus and Litoria rubella) in Australia. Bufo marinus eggs and hatchlings are highly toxic to predatory native tadpoles. Under naturalistic conditions, populations of predatory L. ornatus tadpoles experienced significantly reduced survival when exposed to Bufo eggs and hatchlings. The impact of Bufo on L. ornatus survival was positively correlated with Bufo density. However, the toxic effects of Bufo on L. ornatus indirectly facilitated the survival of later-breeding L. rubella by altering predator-prey interactions between L. ornatus and L. rubella. Limnodynastes ornatus tadpoles are voracious predators of L. rubella eggs and hatchlings. Consequently, the negative impact of Bufo on populations of L. ornatus tadpoles reduced the intensity of predation by L. ornatus tadpoles on L. rubella eggs and hatchlings, thereby increasing L. rubella survival. The results demonstrate that B. marinus plays an important role in structuring native larval anuran communities via direct and indirect mechanisms, and that Bufo may have both negative and positive effects on populations of native anuran larvae. As far as I am aware, these are the first quantitative data to demonstrate that introduced fauna may affect populations of native biota via toxic effects. [source]

    Contrasting seasonal dynamics in fleas of the Siberian flying squirrel (Pteromys volans) in Finland

    Abstract 1.,The seasonal and spatial variation of the adult flea fauna (Siphonaptera) was examined in connection with live-trapping studies of the Siberian flying squirrel (Pteromys volans) in three study areas in southern Finland between 1997 and 2005. 2.,The numerically dominant flea species of the Siberian flying squirrel were Tarsopsylla octodecimdentata octodecimdentata and Ceratophyllus (Monopsyllus) indages indages (Ceratophyllidae); the latter being a host specialist of the Siberian flying squirrel. Tarsopsylla octodecimdentata, which also commonly occurs on the red squirrel (Sciurus vulgaris), infected a large proportion of the host population throughout the winter, whereas C. indages occurred predominantly during the summer and autumn, being practically the only flea species in nests during the flying squirrels' breeding season and on juveniles still inhabiting their natal nest. 3.,The use of nest boxes by flying squirrels did not have any positive effects on flea populations, but it may have had a negative impact on T. octodecimdentata. 4.,The potentially vulnerable C. i. indages is a predictable, widespread component in the flea fauna of the Siberian flying squirrel at various spatial scales, and it is likely to occur in most of the permanent flying squirrel populations in Finland. [source]

    Effects of insects on primary production in temperate herbaceous communities: a meta-analysis

    Malcolm D. Coupe
    Abstract., 1. The effects of insects on primary production in temperate herbaceous communities were investigated in a meta-analysis. The following hypotheses were tested: (1) the effect of insects on primary production depends on community type, (2) the effect of insects on primary production varies as a function of productivity, (3) insects have a greater effect on primary production in communities with low species diversity, and (4) insects have a larger effect on primary production during outbreaks. 2. Data were collected from 24 studies in which insecticides were used to suppress insects in self-sown or pastoral communities. Effect sizes were calculated from sprayed and control plot standing crop or yield, expressed as the log response ratio, ln (sprayed plot phytomass/control plot phytomass). 3. There was a significant increase in primary production as a result of insect suppression. Forb-dominated communities showed a more variable response than graminoid communities. During outbreaks, insects had a greater negative impact on primary production. Effect size was unaffected by productivity or plant species richness. 4. Although insects lower primary production in a diversity of temperate herbaceous communities, the basic measures by which such communities are often described have little effect on the proportional impact that insects have on primary production. While outbreaks are significant predictors of higher negative impact on primary production, causes of outbreaks are not always related to traits of the plant community. [source]

    Spatial correlations of Diceroprocta apache and its host plants: evidence for a negative impact from Tamarix invasion

    Aaron R. Ellingson
    Abstract 1. The hypothesis that the habitat-scale spatial distribution of the Apache cicada Diceroprocta apache Davis is unaffected by the presence of the invasive exotic saltcedar Tamarix ramosissima was tested using data from 205 1-m2 quadrats placed within the flood-plain of the Bill Williams River, Arizona, U.S.A. Spatial dependencies within and between cicada density and habitat variables were estimated using Moran's I and its bivariate analogue to discern patterns and associations at spatial scales from 1 to 30 m. 2. Apache cicadas were spatially aggregated in high-density clusters averaging 3 m in diameter. A positive association between cicada density, estimated by exuvial density, and the per cent canopy cover of a native tree, Goodding's willow Salix gooddingii, was detected in a non-spatial correlation analysis. No non-spatial association between cicada density and saltcedar canopy cover was detected. 3. Tests for spatial cross-correlation using the bivariate IYZ indicated the presence of a broad-scale negative association between cicada density and saltcedar canopy cover. This result suggests that large continuous stands of saltcedar are associated with reduced cicada density. In contrast, positive associations detected at spatial scales larger than individual quadrats suggested a spill-over of high cicada density from areas featuring Goodding's willow canopy into surrounding saltcedar monoculture. 4. Taken together and considered in light of the Apache cicada's polyphagous habits, the observed spatial patterns suggest that broad-scale factors such as canopy heterogeneity affect cicada habitat use more than host plant selection. This has implications for management of lower Colorado River riparian woodlands to promote cicada presence and density through maintenance or creation of stands of native trees as well as manipulation of the characteristically dense and homogeneous saltcedar canopies. [source]

    Behaviourally structured populations persist longer under harsh environmental conditions

    ECOLOGY LETTERS, Issue 5 2003
    Sergei V. Petrovskii
    Abstract The factors and mechanisms that enhance population persistence in a fragmented habitat and/or under harsh environmental conditions are of significant current interest. We consider the dynamics of a population in an isolated habitat surrounded by an unfavourable environment subject to different behavioural responses between the individuals. We assume that there are two responses available: one of them is aggression in its extreme form, the other is its contrary when an individual takes flight in order to avoid any contact with its conspecific. We show that a behaviourally structured population consisting of individuals with fixed behavioural responses is intrinsically less prone to extinction under harsh environmental condition than a population where the individuals can ,choose' between the two given behaviours. We also show that, contrary to an intuitively expected negative impact of aggression on population persistence, the optimal conditions for population persistence are reached when a considerable proportion of the individuals exhibit aggressive behaviour. [source]

    Effect of habitat fragmentation on spawning migration of brown trout (Salmo trutta L.)

    C. Gosset
    Abstract , Human-induced habitat alteration is one of the main causes of the decline of freshwater fish populations. The watershed of the River Bidasoa (Spain) is an example of heavily fragmented habitat. The local brown trout (Salmo trutta L.) population is disturbed, with evidence of poor recruitment as well as low adult densities in the main stem. Forty male and female adult migratory trout were tagged with external or internal radio transmitters and released. Fixed stations with data loggers and mobile antennae were used with daily surveys to track fish movements during the migration and spawning period (3 months). Migration distances did not exceed 10 km, and half of the fish never entered a tributary in the study area. Fragmentation because of weirs on the main stem apparently prevented fish from reaching their spawning destination. Fish that entered the tributaries were first confronted with an accessibility problem because of low discharge. However, each fish chose one tributary, without making attempts to run up in other tributaries. Once in the tributary, fish were restrained in their upstream movements by dams. The study area appeared to be isolated from the vast upper part of the watershed. Within the study area, upper parts of tributaries also seemed strongly disconnected from the main stem. This study illustrates the negative impact of river fragmentation on S. trutta migration pattern. Population sustainability can be directly affected through the low availability of spawning grounds for migratory fish. Long-term effects of fragmentation may cause reproductive isolation within watersheds, which in the case of trout also means isolated phenotypic population units. [source]

    What Happens When Wal-Mart Comes to Town: An Empirical Analysis of the Discount Retailing Industry

    ECONOMETRICA, Issue 6 2008
    Panle Jia
    In the past few decades multistore retailers, especially those with 100 or more stores, have experienced substantial growth. At the same time, there is widely reported public outcry over the impact of these chain stores on other retailers and local communities. This paper develops an empirical model to assess the impact of chain stores on other discount retailers and to quantify the size of the scale economies within a chain. The model has two key features. First, it allows for flexible competition patterns among all players. Second, for chains, it incorporates the scale economies that arise from operating multiple stores in nearby regions. In doing so, the model relaxes the commonly used assumption that entry in different markets is independent. The lattice theory is exploited to solve this complicated entry game among chains and other discount retailers in a large number of markets. It is found that the negative impact of Kmart's presence on Wal-Mart's profit was much stronger in 1988 than in 1997, while the opposite is true for the effect of Wal-Mart's presence on Kmart's profit. Having a chain store in a market makes roughly 50% of the discount stores unprofitable. Wal-Mart's expansion from the late 1980s to the late 1990s explains about 40,50% of the net change in the number of small discount stores and 30,40% for all other discount stores. Scale economies were important for Wal-Mart, but less so for Kmart, and the magnitude did not grow proportionately with the chains' sizes. [source]


    ECONOMIC AFFAIRS, Issue 1 2009
    Mark Hellowell
    This article outlines and critiques the main fiscal and economic rationales for the Private Finance Initiative and examines the impact of the policy on the long-term financial viability of NHS trusts. It concludes that the PFI funding of capital investment is highly problematic. Its high costs can have a negative impact on the finances of health systems. [source]


    ECONOMIC INQUIRY, Issue 2 2008
    This study adds to the limited literature on the demand for casino gaming. The major focus is on the effect of a statewide smoking ban. A system of slot machine demand equations, one each for the three Delaware racinos (racetrack casinos), was developed. The number of slot machines at a racino, at competing in-state racinos, and income were significant demand determinants. Competing out-of-state gaming venues had insignificant effects on gaming demand over the study period. The smoking ban had a significant negative impact on demand, which was not significantly different across the three racinos. The smoking ban reduced gaming demand 15.9%. (JEL L83) [source]