Subsequent Years (subsequent + year)

Distribution by Scientific Domains
Distribution within Life Sciences


Selected Abstracts


Trauma in the family: groupwork on family awareness for men in high security hospital

CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 4 2000
Estelle Moore BSc MSc PhD C.Psychol
Introduction It is typically considered important in clinical practice to generate an understanding of the relationships and consequences of interaction patterns within the families of patients with serious interpersonal difficulties and histories of violent offending. Method Eight men on a dedicated treatment unit for patients with personality disturbance within a maximum security hospital participated in structured groupwork which focused on family awareness. Results Two measures of outcome were employed: their recollections of family life were assessed before and after the intervention, and their general progress in rehabilitation was followed up 12 months later. Summary scores of the participants' recall of feelings associated with familial figures indicate that the group reported changes in their feelings over the eight-month period. For the duration of the group, and during the subsequent year, the group members remained on the same ward; two had been transferred to medium security at follow-up. Discussion The inherent bias and the small numbers in the group prevent generalization. However, it seems that patients who participated in group work are likely to remain on the ward studied or be moved to lower security. The recollection and sharing experiences of family life may have reduced the patients' sense of isolation. Copyright © 2000 Whurr Publishers Ltd. [source]


Association of the metabolic syndrome with depression and anxiety in Japanese men: A 1-year cohort study

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 8 2009
Takeaki Takeuchi
Abstract Background Recent studies on the association between the metabolic syndrome (MetS) and depression have reported conflicting findings. This 1-year cohort study aims to evaluate the association of MetS with the development of both depression and anxiety. Methods The cohort comprised 956 Japanese male employees of an enterprise (mean age, 42.7 years; SD, 10.2 years). MetS was diagnosed according to the International Diabetes Federation criteria. The psychological conditions of depression and anxiety were assessed in 2 successive years by using the profile of mood states (POMS) questionnaire and by conducting clinical interviews as per the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). We evaluated the temporal and dose-response relationships between MetS and the development of depression and anxiety, controlling for potential confounding factors like age and lifestyle-related factors. Results We identified a positive relationship between MetS at baseline and new-onset depression in the subsequent year (OR 2.14, 95% CI 1.10,4.17). Of the five MetS components examined, only waist circumference was significantly related to new-onset depression (OR 2.08, 1.23,3.50). Trend analysis revealed a significant positive trend of association between the number of MetS components identified and new-onset depression (Ptrend < 0.01), but not between Mets and new-onset anxiety. Conclusions Our results suggest that MetS is a predictive factor for the development of depression, and that waist circumference largely contributes to the association between MetS and depression. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Scottish smoke-free legislation and trends in smoking cessation

ADDICTION, Issue 11 2008
Freya J. I. Fowkes
ABSTRACT Aim To investigate trends in smoking cessation before and after the introduction of Scottish smoke-free legislation and to assess the perceived influence of the legislation on giving up smoking and perceptions of the legislation in smokers. Design, setting and participants Longitudinal data on smoking cessation were obtained from 1998 to 2007 on a cohort of 3350 Scottish adults aged between 50 and 75 years at baseline. All members of the cohort were participating in a clinical trial of aspirin in people at moderately increased risk of cardiovascular events. A subgroup of 474 participants who had smoked in the year prior to the introduction of legislation in March 2006 also completed a questionnaire on the influence and perceptions of the smoke-free legislation following its introduction. Measurements Smoking status was recorded yearly, including dates of quitting and restarting. Participants who gave up smoking for at least 3 months were recorded as having quit smoking. The questionnaire included scales on whether the smoke-free legislation had helped/influenced cessation, made the individual think about/prompt them to quit and perceptions of the legislation. Findings The odds of smokers quitting annually increased throughout the 7-year period prior to introduction of the smoke-free legislation to 2 years afterwards (odds ratio 1.09, 95% confidence interval 1.05,1.12, P < 0.001). During 2006, the pattern of quarterly quitting rates changed, with an increase in quit rates (to 5.1%) in the 3-month period prior to introduction of the legislation (January,March 2006). Socio-economic status was not related to smoking cessation. In the subgroup completing the questionnaire (n = 474), 57 quit smoking between June 2005 and May 2007 and 43.9% of these said that the smoke-free legislation had helped them to quit. Most (>70%) smokers were positive about the legislation, especially those from more affluent compared with more deprived communities (P = 0.01). Conclusions The Scottish smoke-free legislation was associated with an increase in the rate of smoking cessation in the 3-month period immediately prior to its introduction. Overall quit rates in the year the legislation was introduced and the subsequent year were consistent with a gradual increase in quit rates prior to introduction of the legislation. Socio-economic status was not related to smoking cessation, but individuals from more affluent communities were more positive about the legislation. [source]


Effects of drought on contrasting insect and plant species in the UK in the mid-1990s

GLOBAL ECOLOGY, Issue 1 2002
M. D. Morecroft
Abstract Aim We examined the effects of drought in the summer of 1995 and the subsequent year on contrasting species of plants, moths, butterflies and ground beetles. We tested whether population increases were associated with: (a) species of warm environments (b) species of dry environments (c) species with rapid reproduction (d) species with high rates of dispersal. Location The study was conducted at Environmental Change Network (ECN) sites throughout Great Britain and Northern Ireland. Methods Climate monitoring, recording of plant species in permanent plots, transect walking for butterflies, light trapping for moths and pitfall trapping for carabid beetles were used. Results There was an overall increase in the number of species recorded in permanent vegetation plots between 1994 and 1996, principally among the annual and biennial vascular plants, probably as a result of gap colonization in grasslands. Most butterfly and moth species increased between 1994 and 1995. Among the butterflies, a southern distribution and high mobility were associated with species tending to increase throughout the period 1994,96, whereas declining species tended to have a northern distribution. A similar number of carabid beetle species increased as decreased in the period 1994,96; decreasing species tended to be associated with lower temperatures and wetter soils. Conclusions Current climate change scenarios indicate that the incidence of droughts in the United Kingdom will increase. A series of dry, hot summers could lead to a rapid change in the population of some species although others, including many plants, may be more resilient. This may lead to complex changes in ecosystems and needs to be considered in planning conservation strategies. [source]


The UCLan community engagement and service user support (Comensus) project: valuing authenticity, making space for emergence

HEALTH EXPECTATIONS, Issue 4 2007
Soo Downe BA (Hons) RM MSc PhD
Abstract Objective, To develop and evaluate service user, carer and community involvement in health and social care education. Background, Despite the high policy profile of involvement issues, there appear to be no published accounts of schemes that have used a systematic whole-faculty approach to community engagement in health and social care higher education. Focus of this paper, The set up and early development of a faculty-wide community engagement project. Setting and participants, Staff from the faculty of health in one University, local service users and carers and community group project workers and local National Health Service (NHS) and public sector staff. Design, Participatory action research including document review, field notes, questionnaires and interviews. Analysis, Thematic analysis. The emerging themes were tested by seeking disconfirming data, and through verification with stake-holders. Results, Prior to the study, there were examples of community engagement in the participating faculty, but they occurred in specific departments, and scored low on the ,ladder of involvement'. Some previous attempts at engagement were perceived to have failed, resulting in resistance from staff and the community. Despite this, an advisory group was successfully formed, and project framing and development evolved with all stake-holders over the subsequent year. The four themes identified in this phase were: building accessibility; being ,proper' service users/carers;moving from suspicion to trust: mutually respectful partnerships as a basis for sustainable change; and responses to challenge and emergence. Conclusions, Successful and sustainable engagement requires authenticity. Many problems and solutions arising from authentic engagement are emergent, and potentially challenging to organizations. [source]


Factors influencing territorial occupancy and reproductive output in the Booted Eagle Hieraaetus pennatus

IBIS, Issue 4 2006
JOSÉ E. MARTÍNEZ
During a 7-year research project in a forested area of southeastern Spain, we studied territorial occupancy and reproductive success in a Booted Eagle Hieraaetus pennatus population. We monitored 65 territories, gathering information on 406 occupancy events and 229 breeding attempts, including those of two potential competitors, the Northern Goshawk Accipiter gentilis and the Common Buzzard Buteo buteo. Generalized linear mixed models were used to explain occupancy and productivity, by evaluating the relative contribution of three different types of variables (habitat, competition and past events) and considering territory as a random effect. We examined a set of a priori hypothesized models, together with a number of additional models, and selected the best models following an information-theoretic approach. Our best models related territorial occupancy and productivity to previous breeding success (the fledging of one or two young), which appeared to be the most important factor determining the probability of reoccupation and the reproductive output in the subsequent year. The best occupation model revealed that the probabilities of occupancy were also conditioned by a competition variable (intraspecific nearest-neighbour distance) and two habitat variables (the location of the nest on the valley slope and the distance to the nearest forest track). Unlike the best occupation model, however, the selected model for reproductive output did not incorporate any competition variable besides previous breeding success, but included another two habitat variables (the effects of trunk height and NNE orientation). [source]


Self-Reported Sleep and Nap Habits and Risk of Falls and Fractures in Older Women: The Study of Osteoporotic Fractures

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2006
Katie L. Stone PhD
OBJECTIVES: To test the association between self-reported sleep and nap habits and risk of falls and fractures in a large cohort of older women. DESIGN: Study of Osteoporotic Fractures prospective cohort study. SETTING: Clinical centers in Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; and the Monongahela Valley, near Pittsburgh, Pennsylvania. PARTICIPANTS: Eight thousand one hundred one community-dwelling Caucasian women aged 69 and older (mean 77.0). MEASUREMENTS: Sleep and nap habits were assessed using a questionnaire at the fourth clinic visit (1993/94). Fall frequency during the subsequent year was ascertained using tri-annual questionnaire. Incident hip and nonspinal fractures during 6 years of follow-up were confirmed using radiographic reports. RESULTS: Five hundred fifty-three women suffered hip fractures, and 1,938 suffered nonspinal fractures. In multivariate models, women who reported napping daily had significantly higher odds of suffering two or more falls during the subsequent year (odds ratio=1.32, 95% confidence interval (CI)=1.03,1.69) and were more likely to suffer a hip fracture (hazard ratio (HR)=1.33, 95% CI=0.99,1.78) than women who did not nap daily. Those sleeping at least 10 hours per 24 hours had a higher risk of nonspinal fracture than (HR=1.26, 95% CI=1.00,1.58) and a similar but nonsignificant increased risk of hip fracture to (HR=1.43, 95% CI=0.95,2.15) those who reported sleeping between 8 and 9 hours. CONCLUSION: Self-reported long sleep and daily napping are associated with greater risk of falls and fractures in older women. Interventions to improve sleep may reduce their risk of falls and fractures. Future research is needed to determine whether specific sleep disorders contribute to these relationships. [source]


Pathological and epidemiological observations on rickettsiosis in cultured sea bass (Dicentrarchus labrax L.) from Greece

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2004
F. Athanassopoulou
Summary A systemic infection of a Rickettsia -like organism (RLO) in cultured sea bass is described for the first time. In hatcheries, clinical signs were lethargy, inappetence and discoloration. Twenty days after transfer to sea cages from hatcheries where the disease existed, fish showed erratic and abnormal swimming behaviour, loss of orientation, and lethargy. Cumulative mortality in colder months of the year reached 30% in hatcheries and 80% in cages. Surviving fish in cages did not show any clinical signs of RLO infection in the subsequent year. Evidence for a systemic distribution of RLO was supported by histolopathological lesions in both infected hatchery and caged fish, where the lesion profile included cranial sensory, central nervous, integumental and alimentary organ systems. Intracranial lesions were primarily characterized by an ascending histiocytic perineuritis and necrotizing congestive meningoencephalitis, with evidence for transfer of infective agents across the blood,brain barrier confirmed by the presence of RLOs within capillary endothelium and histiocytes in inflamed regions of the optic tectum and the cerebellum. In the most severe cases, infection spread to the statoacoustical (semicircular) canal system and the ependymal lining of ventricles, with marked rickettsial-laden histiocytic infiltration of the canal lumen. Integumental lesions were restricted to the oral submucosa, nares and integumental dermis of the cranium. Alimentary lesions were noted in both the liver parenchyma and mucosa/submucosa of the stomach. In all affected organs the RLOs were found by immunohistochemistry to be related to Piscirickettsia salmonis. [source]


Vernalization requirement of wild beet Beta vulgaris ssp. maritima: among population variation and its adaptive significance

JOURNAL OF ECOLOGY, Issue 4 2002
Pierre Boudry
Summary 1Seven populations of Beta vulgaris ssp. maritima (wild beet) situated along a latitudinal cline were studied for their vernalization requirement and its consequences for fitness. 2Various cold regimes were applied in glasshouses and experimental gardens with plants of different ages. Three additional experimental sites (on the French Mediterranean, Atlantic and North Sea coasts) situated near three of the sampled populations, and thus including a reciprocal transplant design, were used to evaluate the influence of latitude under natural conditions. Survival and plant size were measured over 3 years. 3The vernalization requirement was greater in plants from more northern origins. The level of cold required to allow flowering overcompensated for the colder springs, so that northern plants in northern sites flowered less than southern plants in southern sites. 4Young seedlings were more difficult to vernalize than plants that had already developed vegetative rosettes. 5Differences in vernalization requirement seem to be an adaptive response to spring temperatures and season length in a particular latitude. A whole winter vernalization almost always led to flowering in the subsequent year whatever the latitude or geographical origin. 6Plants from the Atlantic and Channel coasts showed the highest lifetime reproductive success at all sites. Southern populations were better adapted to disturbed habitats as shown by their higher first-year reproductive success. The North Sea population had a lower reproductive success than the Atlantic populations, even in its native environment. [source]


Effects of pets on asthma development up to 8 years of age: the PIAMA study

ALLERGY, Issue 8 2009
M. Kerkhof
Background:, Recall bias may provide discrepant relationships of pet exposure with sensitization and asthma development. We studied prospectively effects of pets at home on development of sensitization, asthma and respiratory symptoms from birth up to age 8 years. Methods:, Event history analysis was performed on annually registered data of 2951 children, participating in the PIAMA birth cohort study. Results:, Children with a cat or dog at home at 3 months of age had a significantly lower prevalence of sensitization to inhalant allergens at age 8, but not of asthma. A cat decreased the risk of house dust mite sensitization at age 8 [odds ratio (OR) = 0.68, 95% confidence interval (CI) 0.49,0.95], a dog of pollen sensitization (OR = 0.49, 95% CI: 0.29,0.83). A cat or dog at home did not significantly affect asthma incidence in each subsequent year. From 2 years of age onwards, the incidence of wheeze (OR = 1.52, 95% CI: 1.12,2.05) and a dry cough at night (OR = 1.28, 95% CI: 1.05,1.57) was higher in children with a dog, whereas removal of a dog increased the risk of developing asthma symptoms. Comparing analyses using prospectively and retrospectively collected data on diagnosed asthma showed important recall bias. Conclusions:, Our prospective study shows a protective effect of early presence of pets at home on sensitization to inhalant allergens, but no prevention of asthma development. Furthermore, children with pets had more frequent transient or intermittent asthma symptoms. Parental report of asthma by recall may provide spurious results of these associations. [source]


The economic impact of severe asthma to low-income families

ALLERGY, Issue 3 2009
R. Franco
Background:, To estimate the direct and indirect costs of severe asthma and the economic impact of its management to low-income families in Salvador, Brazil. Methods:, One hundred and ninety-seven patients with severe asthma and referred to a state-funded asthma center providing free treatment were evaluated. At registration, they were asked about family cost-events in the previous year and had a baseline assessment of lung function, symptoms and quality of life. During the subsequent year, they were reassessed prospectively. Results:, One hundred-eighty patients concluded a 12-month follow-up. Eighty-four percent were female patients, and the median family income was US$ 2955/year. Forty-seven percent of family members had lost their jobs because of asthma. Total cost of asthma management took 29% of family income. After proper treatment, asthma control scores improved by 50% and quality of life by 74%. The income of the families increased by US$ 711/year, as their members went back to work. The total cost of asthma to the families was reduced by a median US$ 789/family/year. Consequently, an annual surplus of US$ 1500/family became available. Conclusions:, Family costs of severe asthma consumed over one-fourth of the family income of the underprivileged population in a middle-income country. Adequate management brings major economic benefit to individuals and families. [source]


Childhood malnutrition and its predictors in rural Malawi

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 4 2003
Kenneth Maleta
Summary We prospectively followed up a population-based cohort of 767 rural Malawian children from birth to 36 months to characterise the timing and predictors of malnutrition. Underweight and wasting incidence peaked between 6 and 18 months of age, whereas stunting incidence was highest during the first 6 months of age. After infancy about 40% of the children were underweight, 70% stunted, and about 4% wasted. Small size during the first 3 months of life predicted the incidence of severe underweight (relative risk [95% confidence interval], 1.8 [0.9, 3.4]), severe stunting ( 2.1 [1.3, 3.4]), and moderate wasting (2.0 [1.1, 3.5]). Children with many illness episodes in infancy had a twofold risk for the development of severe underweight and moderate wasting. Severe underweight was further predicted by residence far away from a health facility and moderate wasting by maternal HIV infection. Our conclusion is that the intrauterine period and first 6 months of life are critical for the development of stunting whereas the subsequent year is more critical for the development of underweight and wasting. Strategies combating intrauterine growth retardation, maternal HIV and infant morbidity are likely to reduce the burden of malnutrition in this population. [source]


Transfer of life-history phenology from mothers to progeny in a solitary univoltine parasitoid

PHYSIOLOGICAL ENTOMOLOGY, Issue 2 2010
ANDREW A. FORBES
Among univoltine insects that experience diapause, differences in emergence timing between adult males and females are expected to be dictated by sex-specific developmental factors. In multivoltine insects without a diapause, there is often an additional relationship between the date of oviposition and the date of adult emergence. Differences between male and female emergence timing in the latter case can therefore be influenced by female sex-allocation decisions. In the present study, it is shown that eggs of a univoltine parasitoid wasp Diachasma alloeum Muesebeck (Hymenoptera: Braconidae) that are laid earlier also eclose earlier during the subsequent year, independent of (although complementary to) sex-related differences in development time. The implications of this pattern for sex allocation decisions by female univoltine parasitoids are discussed. [source]


One-year Outcomes Following Coronary Computerized Tomographic Angiography for Evaluation of Emergency Department Patients with Potential Acute Coronary Syndrome

ACADEMIC EMERGENCY MEDICINE, Issue 8 2009
Judd E. Hollander MD
Abstract Objectives:, Coronary computerized tomographic angiography (CTA) has high correlation with cardiac catheterization and has been shown to be safe and cost-effective when used for rapid evaluation of low-risk chest pain patients from the emergency department (ED). The long-term outcome of patients discharged from the ED with negative coronary CTA has not been well studied. Methods:, The authors prospectively evaluated consecutive low- to intermediate-risk patients who received coronary CTA in the ED for evaluation of a potential acute coronary syndrome (ACS). Patients with cocaine use, known cancer, and significant comorbidity reducing life expectancy and those found to have significant disease (stenosis , 50% or ejection fraction < 30%) were excluded. Demographics, medical and cardiac history, labs, and electrocardiogram (ECG) results were collected. Patients were followed by telephone contact and record review for 1 year. The main outcome was 1-year cardiovascular death or nonfatal acute myocardial infarction (AMI). Results:, Of 588 patients who received coronary CTA in the ED, 481 met study criteria. They had a mean (±SD) age of 46.1 (±8.8) years, 63% were black or African American, and 60% were female. There were 53 patients (11%) rehospitalized and 51 patients (11%) who received further diagnostic testing (stress or catheterization) over the subsequent year. There was one death (0.2%; 95% confidence interval [CI] = 0.01% to 1.15%) with unclear etiology, no AMI (0%; 95% CI = 0 to 0.76%), and no revascularization procedures (0%; 95% CI = 0 to 0.76%) during this time period. Conclusions:, Low- to intermediate-risk patients with a Thrombosis In Myocardial Infarction (TIMI) score of 0 to 2 who present to the ED with potential ACS and have a negative coronary CTA have a very low likelihood of cardiovascular events over the ensuing year. [source]


Direct medical costs and their predictors in patients with rheumatoid arthritis

ARTHRITIS & RHEUMATISM, Issue 10 2003
527 patients, A three-year study of
Objective To estimate total direct medical costs in persons with rheumatoid arthritis (RA) and to characterize predictors of these costs. Methods Patients (n = 7,527) participating in a longitudinal study of outcome in RA completed 25,050 semiannual questionnaires from January 1999 through December 2001. From these we determined direct medical care costs converted to 2001 US dollars using the consumer price index. We used generalized estimating equations to examine potential predictors of the costs. Monte Carlo simulations and sensitivity analyses were performed to evaluate the varying prevalence and cost of biologic therapy. Results The mean total annual direct medical care cost in 2001 for a patient with RA was $9,519. Drug costs were $6,324 (66% of the total), while hospitalization costs were only $1,573 (17%). Approximately 25% of patients received biologic therapy. The mean total annual direct cost for patients receiving biologic agents was $19,016 per year, while the cost for those not receiving biologic therapy was $6,164. RA patients who were in the worst quartile of functional status, as measured by the Health Assessment Questionnaire, experienced direct medical costs for the subsequent year that were $5,022 more than the costs incurred by those in the best quartile. Physical status as determined by the Short Form 36 physical component scale had a similar large effect on RA costs, as did comorbidity. Medical insurance type played a more limited role. However, those without insurance had substantially lower service utilization and costs, and health maintenance organization patients had lower drug costs and total medical costs. Increased years of education, increased income, and majority ethnic status were all associated with increased drug costs but not hospitalization costs. Costs in all categories decreased after age 65 years. Conclusion Estimates of direct medical costs for patients with RA are substantially higher than cost estimates before the biologic therapy era, and costs are now driven predominantly by the cost of drugs, primarily biologic agents. RA patients with poor function continue to incur substantially higher costs, as do those with comorbid conditions, and sociodemographic characteristics also play an important role in determination of costs. [source]


How do plants know when other plants are flowering?

ECOLOGY LETTERS, Issue 11 2009
Resource depletion, mast-seeding in a perennial wildflower, pollen limitation
Abstract Mast-seeding is the synchronous and periodic reproduction by plant populations. This phenomenon has been widely studied from a community-level perspective, but we know extremely little about how plants are able to synchronize reproduction. Here, we present the first experimental test of proximate mechanisms of mast-seeding, by preventing reproduction in an iteroparous, mast-seeding wildflower. Through a series of experiments, we show that mobile carbohydrate stores (NSC) control alternate-year flowering by individual plants; seed set depletes NSC which prevents flowering the following year. Plants are synchronized by density-dependent pollen limitation; when plants flower asynchronously, they set fewer seeds, which prevents NSC depletion. Therefore, these individual plants flower in subsequent years and become synchronized. Because mast-seeding is a consequence of physiological controls of reproduction, differences in plant resource acquisition and allocation could dramatically change patterns of seed production, and changes in plant consumers and pollinators could change selection on physiological and developmental pathways. [source]


Non-invasive longitudinal assessment of facial growth in children and adolescents with hypohidrotic ectodermal dysplasia

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2008
Claudia Dellavia
Facial growth patterns in 12 subjects (six boys and six girls) with hypohidrotic ectodermal dysplasia (HED) were analyzed and compared with facial growth patterns obtained in healthy reference peers. All subjects with HED were aged 7 yr (mean age ± standard deviation: 7.08 ± 0.41 yr) at the first examination and 14 yr (mean age ± standard deviation: 14.56 ± 0.34 yr) at the last examination. In each subject, the three-dimensional coordinates of facial landmarks were collected non-invasively at eight subsequent years. The volumes of forehead, nose, maxilla and mandible, upper lips, and lower lips were estimated. For each facial volume, differential values between different time points were calculated individually, separately for the ,childhood' (7,10 yr) and the ,adolescence' (11,14 yr) growth period in both HED and reference subjects. Children and adolescents with HED had a slightly reduced global facial growth in comparison with normal reference peers. The peak mandibular and maxillary development was delayed by approximately 2 yr towards later adolescence. The present non-invasive system seems to be useful for studying longitudinal changes of facial growth in healthy and syndromic subjects. [source]


TEMPORAL VARIATION IN DIVERGENT SELECTION ON SPINE NUMBER IN THREESPINE STICKLEBACK

EVOLUTION, Issue 12 2002
T. E. Reimchen
Abstract., Short-term temporal cycles in ecological pressures, such as shifts in predation regime, are widespread in nature yet estimates of temporal variation in the direction and intensity of natural selection are few. Previous work on threespine stickleback (Gasterosteus aculeatus) has revealed that dorsal and pelvic spines are a defense against gape-limited predators but may be detrimental against grappling insect predators. In this study, we examined a 15-year database from an endemic population of threespine stickleback to look for evidence of temporal shifts in exposure to these divergent predation regimes and correlated shifts in selection on spine number. For juveniles, we detected selection for increased spine number during winter when gape-limited avian piscivores were most common but selection for decreased spine number during summer when odonate predation was more common. For subadults and adults, which are taken primarily by avian piscivores, we predicted selection should generally be for increased spine number in all seasons. Among 59 comparisons, four selection differentials were significant (Bonferroni corrected) and in the predicted direction. However, there was also substantial variability in remaining differentials, including two examples with strong selection for spine reduction. These reversals were associated with increased tendency of the fish to shift to a benthic niche, as determined from examination of stomach contents. These dietary data suggest that increased encounter rates with odonate predation select for spine reduction. Strong selection on spine number was followed by changes in mean spine number during subsequent years and a standard quantitative genetic formula revealed that spine number has a heritable component. Our results provide evidence of rapid morphological responses to selection from predators and suggest that temporal variation in selection may help maintain variation within populations. Furthermore, our findings indicate that variable selection can be predicted if the agents of selection are known. [source]


Skipped spawning in female iteroparous fishes

FISH AND FISHERIES, Issue 1 2005
Rick M Rideout
Abstract It is often assumed that iteroparous fishes spawn annually once reaching sexual maturity, but this is not always the case. This paper reviews available information on skipped spawning in female teleost fishes. All instances of non-annual spawning are described as one of three types (retaining, reabsorbing, resting), depending on where in the normal spawning cycle development has been interrupted. Retaining ripe eggs is caused by conditions experienced during the spawning season (fish density, mate availability, pollution), whereas failure to start vitellogenesis (resting) or the breakdown of all oocytes that enter into vitellogenesis (reabsorbing) is caused by factors experienced prior to the spawning season (primarily temperature and poor nutrition). It is speculated that the relative shortage of data on non-annual spawning may be because of difficulties in identifying non-reproductive individuals. In an attempt to rectify this situation, the criteria needed to identify females undergoing the three forms of spawning omission are presented in terms of external appearance of gonads, gonad indices, and histological analysis. The energy saved by not spawning in a poor year may lead to increased survival and the probability of spawning in subsequent years. As the cumulative number of progeny gained by surviving to spawn in multiple subsequent years outweighs the number of progeny lost by not spawning in a given single year, occasional omission of spawning may constitute an adaptive trait in long-lived iteroparous fishes. [source]


Stocking piscivores to improve fishing and water clarity: a synthesis of the Lake Mendota biomanipulation project

FRESHWATER BIOLOGY, Issue 12 2002
R. C. Lathrop
SUMMARYY 1.,A total of 2.7 × 106 walleye fingerlings and 1.7 × 105 northern pike fingerlings were stocked during 1987,99 in eutrophic Lake Mendota. The objectives of the biomanipulation were to improve sport fishing and to increase piscivory to levels that would reduce planktivore biomass, increase Daphnia grazing and ultimately reduce algal densities in the lake. The combined biomass of the two piscivore species in the lake increased rapidly from < 1 kg ha,1 and stabilised at 4,6 kg ha,1 throughout the evaluation period. 2.,Restrictive harvest regulations (i.e. increase in minimum size limit and reduction in bag limit) were implemented in 1988 to protect the stocked piscivores. Further restrictions were added in 1991 and 1996 for walleye and northern pike, respectively. These restrictions were essential because fishing pressure on both species (especially walleye) increased dramatically during biomanipulation. 3.,Commencing in 1987 with a massive natural die-off of cisco and declining yellow perch populations, total planktivore biomass dropped from about 300,600 kg ha,1 prior to the die-off and the fish stocking, to about 20,40 kg ha,1 in subsequent years. These low planktivore biomasses lasted until a resurgence in the perch population in 1999. 4.,During the period prior to biomanipulation when cisco were very abundant, the dominant Daphnia species was the smaller-bodied D. galeata mendotae, which usually reached a biomass maximum in June and then crashed shortly thereafter. Beginning in 1988, the larger-bodied D. pulicaria dominated, with relatively high biomasses occurring earlier in the spring and lasting well past mid-summer of many years. 5.,In many years dominated by D. pulicaria, Secchi disc readings were greater during the spring and summer months when compared with years dominated by D. galeata mendotae. During the biomanipulation evaluation period, phosphorus (P) levels also changed dramatically thus complicating our analysis. Earlier research on Lake Mendota had shown that Daphnia grazing increased summer Secchi disc readings, but P concentrations linked to agricultural and urban runoff and to climate-controlled internal mixing processes were also important factors affecting summer readings. 6.,The Lake Mendota biomanipulation project has been a success given that high densities of the large-bodied D. pulicaria have continued to dominate for over a decade, and the diversity of fishing opportunities have improved for walleye, northern pike and, more recently, yellow perch. 7.,Massive stocking coupled with very restrictive fishing regulations produced moderate increases in piscivore densities. Larger increases could be realised by more drastic restrictions on sport fishing, but these regulations would be very controversial to anglers. 8.,If the lake's food web remains in a favourable biomanipulation state (i.e. high herbivory), further improvements in water clarity are possible with future reductions in P loadings from a recently initiated non-point pollution abatement programme in the lake's drainage basin. [source]


Corn stover feedstock trials to support predictive modeling

GCB BIOENERGY, Issue 5 2010
DOUGLAS L. KARLEN
Abstract To be sustainable, feedstock harvest must neither degrade soil, water, or air resources nor negatively impact productivity or subsequent crop yields. Simulation modeling will help guide the development of sustainable feedstock production practices, but not without field validation. This paper introduces field research being conducted in six states to support Sun Grant Regional Partnership modeling. Our objectives are to (1) provide a fundamental understanding of limiting factor(s) affecting corn (Zea mays L.) stover harvest, (2) develop tools (e.g., equations, models, etc.) that account for those factors, and (3) create a multivariant analysis framework to combine models for all limiting factors. Sun Grant modelers will use this information to improve regional estimates of feedstock availability. A minimum data set, including soil organic carbon (SOC), total N, pH, bulk density (BD), and soil-test phosphorus (P), and potassium (K) concentrations, is being collected. Stover yield for three treatments (0%, 50%, and 90% removal) and concentrations of N, P, and K in the harvested stover are being quantified to assess the impact of stover harvest on soil resources. Grain yield at a moisture content of 155 g kg,1 averaged 9.71 Mg ha,1, matching the 2008 national average. Stover dry matter harvest rates ranged from 0 to 7 Mg ha,1. Harvesting stover increased N,P,K removal by an average of 42, 5, and 45 kg ha,1 compared with harvesting only grain. Replacing those three nutrients would cost $53.68 ha,1 based on 2009 fertilizer prices. This first-year data and that collected in subsequent years is being used to develop a residue management tool that will ultimately link multiple feedstock supplies together in a landscape vision to help develop a comprehensive carbon management plan, quantify corn stover harvest effects on soil quality, and predict regional variability in feedstock supplies. [source]


The microfood web of grassland soils responds to a moderate increase in atmospheric CO2

GLOBAL CHANGE BIOLOGY, Issue 7 2005
Ilja Sonnemann
Abstract The response of the soil microfood web (microflora, nematodes) to a moderate increase in atmospheric CO2 (+20%) was investigated by means of a free air CO2 enrichment experiment. The study was carried out in a seminatural temperate grassland for a period of 4 consecutive years (1 year before fumigation commenced and 3 years with fumigation). Several soil biological parameters showed no change (microbial biomass, bacterial biomass) or decline (microbial respiration) in the first year of elevated CO2 treatment as compared with controls. Each of these parameters were higher than controls, however, after 3 years of treatment. The relative abundance of predaceous nematodes also decreased in year 1 of the experiment, increased in year 2, but decreased again in year 3. In contrast, the relative abundance of root hair feeding nematodes, at first, increased under elevated CO2 and then returned to the initial level again. Increased microbial biomass indicates enhanced C storage in the labile carbon pool of the active microfood web in subsequent years. According to measurements on the amounts of soil extractable C, changes in resource availability seem to be key to the response of the soil microfood web. We found a strong response of bacteria to elevated CO2, while the fungal biomass remained largely unchanged. This contrasts to findings reported in the literature. We hypothesize that this may be because of contrasting effects of different levels of CO2 enrichment on the microbial community (i.e. stimulation of bacteria at moderate levels and stimulation of fungi at high levels of CO2 enrichment). However, various CO2 effects observed in our study are similar in magnitude to those observed in other studies for a much higher level of atmospheric carbon. These include the particular sensitivity of predaceous nematodes and the long-term increase of microbial respiration. Our findings confirm that the potential of terrestrial ecosystems to accumulate additional carbon might be lower than previously thought. Furthermore, CO2 -induced changes of temperate grassland ecosystems might emerge much earlier than expected. [source]


Impacts of a volcanic eruption on the forest bird community of Montserrat, Lesser Antilles

IBIS, Issue 2 2007
B. DALSGAARD
Volcanic eruptions are an important and natural source of catastrophic disturbance to ecological communities. However, opportunities to study them are relatively rare. Here we report on the effects of the eruption of the Soufrière Hills volcano on the forest bird community of the Lesser Antillean island of Montserrat. The island's species-poor avifauna includes 11 restricted-range species, including the Critically Endangered endemic Montserrat Oriole Icterus oberi. Analysis of monitoring data from 1997 to 2005 indicates that counts of most species were substantially lower following major ashfalls. However, this effect was short-lived, with rapid population recovery in subsequent years. Furthermore, levels of seasonal rainfall appear to have been at least as important in determining population trends as ashfall. Overall, most species were at least as abundant at the end of the study as at the start, and no forest bird species have been extirpated from Montserrat. We discuss potential ecological drivers of ashfall impacts on populations: there is some evidence that terrestrial foragers were most severely affected. [source]


Existing theories do not explain sex ratio variation at birth in monomorphic roe deer (Capreolus capreolus)

INTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 1 2007
Stefan Jacob VREUGDENHIL
Abstract The phenomenon of skewed sex ratios at birth has been reported in many ungulate species. So far, no consistent trend has emerged for roe deer (Capreolus capreolus), because male-biased, female-biased and equal sex ratios at birth have all been found. Nevertheless, both the Trivers-Willard hypothesis and the theory of local resource competition have gained support. Despite the great number of studies carried out regarding the ecology of roe deer, too many aspects remain unclear, and contradictory results have been produced with respect to several crucial elements. Without further research, the discussion on which theory applies will therefore remain inconclusive. We put forward the argument that eventually the theories of Trivers-Willard and local resource competition can be considered as being not essentially different. After all, both theories explain the observed skewed sex ratios as being due to the effect of the progeny's sex on the mother's body condition and hence her reproductive success in subsequent years. Furthermore, neither theory is likely to prove to be suitable for roe deer, as several assumptions are unlikely to be met. In roe deer, skewed ratios probably only have a temporal character. As a matter of fact, several observations of skewed sex ratios in birds and mammals did not withstand the accumulation of further data, as sex ratios that were initially believed to be biased turned out to be equal in the long term. This is likely to be the case in roe deer as well. We hypothesize that roe deer, as r-strategists, will produce as many offspring as possible, regardless of sex. [source]


Fruit size and picking scar size in some blueberry commercial cultivars and hybrid plants grown in SW Spain

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2007
Raquel Parra
Summary Within a blueberry research program in SW Spain, five rabbiteye (Vaccinium ashei Reade) and nine southern highbush (Vaccinium corymbosum L.) commercial cultivars along with 38 hybrid plants, produced by crossing highbush and rabbiteye cultivars, were used. The differences in the fruit size and the picking scar size among the plants, and the annual differences within each plant were studied. No significant differences were found in the fruit length, width, weight and the picking scar size between the rabbiteye and the southern highbush cultivars, and neither between the cultivars and the hybrid progeny. However, significant differences were found among the cultivars and among the hybrid plants. The picking scar size correlates better with fruit width and weight than with fruit length, although correlation values are not high. Thus, outliers were observed, some of them interesting to be selected for having large fruits and narrow scars. The ratio between the picking scar and fruit width shows significant differences among subsequent years in many hybrid plants. [source]


Are single-gift committed donors different from their multiple-gift counterparts?

INTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 3 2010
Anyuan Shen
Committed donors who keep giving every year are a key asset for nonprofit organizations because they provide a steady funding source and return a higher lifetime value. We distinguish between committed donors who give only one gift per year (single-gift (SG) donors) and those who give multiple gifts in at least some year (multiple-gift (MG) donors). In this paper, we study whether SG donors and MG donors follow different longitudinal patterns of gift-giving in four consecutive years. We theorize that a donor's yearly gift amount is an indication of his or her willingness to give (WTG) to the organization and may be explained in terms of his or her intrinsic willingness to give (IWTG) and extrinsic willingness to give (EWTG) for that year. We test our theory with data from a leading US nonprofit organization and find that SG donors and MG donors would follow different longitudinal patterns: While SG donors and MG donors would start off at a similar level of WTG in year 1 and would both increase WTG in subsequent years, MG donors would record a higher rate of increase than SG donors. IWTG and EWTG would have different relative importance as determinants of the observed yearly giving level: MG donors depend on both IWTG and EWTG whereas SG donors largely depend on IWTG rather than EWTG to determine how much to give in a year. Our findings suggest that different strategies are needed to manage SG donors and MG donors to sustain and grow annual contributions. Copyright © 2009 John Wiley & Sons, Ltd. [source]


The Extreme Future Stock Returns Following I/B/E/S Earnings Surprises

JOURNAL OF ACCOUNTING RESEARCH, Issue 5 2006
JEFFREY T. DOYLE
ABSTRACT We investigate the stock returns subsequent to quarterly earnings surprises, where the benchmark for an earnings surprise is the consensus analyst forecast. By defining the surprise relative to an analyst forecast rather than a time-series model of expected earnings, we document returns subsequent to earnings announcements that are much larger, persist for much longer, and are more heavily concentrated in the long portion of the hedge portfolio than shown in previous studies. We show that our results hold after controlling for risk and previously documented anomalies, and are positive for every quarter between 1988 and 2000. Finally, we explore the financial results and information environment of firms with extreme earnings surprises and find that they tend to be "neglected" stocks with relatively high book-to-market ratios, low analyst coverage, and high analyst forecast dispersion. In the three subsequent years, firms with extreme positive earnings surprises tend to have persistent earnings surprises in the same direction, strong growth in cash flows and earnings, and large increases in analyst coverage, relative to firms with extreme negative earnings surprises. We also show that the returns to the earnings surprise strategy are highest in the quartile of firms where transaction costs are highest and institutional investor interest is lowest, consistent with the idea that market inefficiencies are more prevalent when frictions make it difficult for large, sophisticated investors to exploit the inefficiencies. [source]


Serum Erythropoietin and Aging: A Longitudinal Analysis

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2005
William B. Ershler MD
Objectives: To determine the changes in serum erythropoietin with age in patients with and without anemia and to assess the importance of certain comorbidities on changes in erythropoietin level and the development of anemia. Design: Clinical history, hematological parameters, and serum erythropoietin levels were examined at 1- to 2-year intervals for 8 to 30 years. Setting: Baltimore Longitudinal Study on Aging (BLSA), National Institute on Aging. Participants: One hundred forty-three BLSA participants. Measurements: Complete blood count and serum chemistries were performed at the time of each visit, and archived serum samples were used for erythropoietin level. Results: Although all subjects were healthy and without anemia at the time of initial evaluation, some developed chronic illness,most notably hypertension and diabetes mellitus. Erythropoietin levels rose significantly for the group as a whole, and the slope of the rise was found to be greater for those who did not have associated diabetes mellitus or hypertension. During the subsequent years, subjects who developed anemia but did not have hypertension or diabetes mellitus had the greatest slope in erythropoietin rise over time, whereas those with hypertension or diabetes mellitus and anemia had the lowest erythropoietin slope. Conclusion: The increase in serum erythropoietin with aging may be compensation for subclinical blood loss, increased red blood cell turnover, or increased erythropoietin resistance of red cell precursors. It is suspected that, with very advanced age, or in those with compromised renal function (e.g., diabetes mellitus or hypertension), the compensatory mechanism becomes inadequate and anemia results. [source]


Selection for birth date in North Sea haddock and its relation to maternal age

JOURNAL OF ANIMAL ECOLOGY, Issue 2 2005
PETER J. WRIGHT
Summary 1Birth date can be important to lifetime reproductive success. However, selection for birth date has rarely been addressed in fish, despite the opportunity provided by otolith microstructure. 2This study examined the relationship between maternal age, spawning time and early survivorship in the North Sea haddock stock. Temporal changes in egg production were compared with the birth date distribution of progeny surviving to the demersal phase in 1994, 1996 and 1999, when the age structure of the spawning stock differed. 3Estimates of intra-annual variation in stock egg production indicated that first-time spawning 2-year-olds began spawning much later than older age-classes. 4The form and magnitude of selection on birth date varied between years, indicating that the production of multiple batches of eggs over an extended period has some adaptive significance to progeny survival. 5Survivorship was consistently poor from the late spawning period when age 2 females contributed most to stock egg production. This persistent selection against late hatched offspring could reflect either low parental investment, as age 2 females produce smaller eggs, or the short length of the growing season prior to settlement. 6Variability in birth date selection, particularly with respect to first vs. subsequent years of spawning, implies a strong selection pressure for a long reproductive lifespan. As such, reproductive potential in this and other exploited fish species with a similar reproductive trait may have been affected adversely by the general decline in repeat spawning females in recent years. [source]


Testing the use of interviews as a tool for monitoring trends in the harvesting of wild species

JOURNAL OF APPLIED ECOLOGY, Issue 4 2008
Julia P. G. Jones
Summary 1Many aspects of human behaviour impact on ecological systems. Ecologists therefore need information on changes in these behaviours and are increasingly using methods more familiar to social scientists. 2Understanding patterns of wildlife harvesting is important for assessing the sustainability of harvests. Interviews are commonly used in which informants are asked to summarize their activities over a period of time. However, few studies have investigated the reliability of such data, the usefulness of interviews for monitoring trends, and how their information content can be maximized. 3We carried out rapid assessment interviews with villagers in Madagascar about the quantity, timing and spatial patterns of crayfish Astacoides granulimanus and firewood collection. We compared the results with information from daily interviews with the same informants. We used mixed models to investigate how accurately people reported their activities in the rapid assessment interviews, and estimated the probability of detecting a change in harvesting from two such interviews using a Bayesian approach. 4The interviews provided reliable information on quantities, effort, and the spatial pattern of harvesting. Simulations suggested the interviews would detect changes in catches and harvesting effort with reasonable power; for example, a 20% change in the amount of time spent crayfish harvesting could be detected with 90% power. Power is higher when the same informants are questioned in repeat interviews. 5Synthesis and applications. Ecologists are increasingly using social techniques and it is vital that they are subject to rigorous testing to ensure robustness in trend detection. This study suggests that interviews can be used to monitor changes in harvesting patterns by resource users, but whether the power is adequate will depend on the needs of the study. To maximize the power of interviews, informants should be interviewed independently and the same informants interviewed in subsequent years. [source]