bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening for depression in a hepatitis C population: the reliability and validity of the Center for Epidemiologic Studies Depression Scale (CES‐D)
Authors: Clark Cinda H. , Mahoney Jane S. , Clark David J. , Eriksen Lillian R. 
Published: March 2003

Rationale.  Depression is reported as a serious adverse event of antiviral therapy used to treat patients with hepatitis C (HCV); therefore, there is a need to identify a reliable and valid measure of depressive symptoms for this population. Aims.  To determine reliability, construct validity and predictive validity of the Center for Epidemiological Studies Depression Scale (CES‐D) in a hepatitis C (HCV) population. Ethical issues.  Study reviewed/approved by the University Institutional Review Board and informed consent obtained. Methods.
Longitudinal design testing psychometric properties of the CES‐D prior to treatment and 4 and 24 weeks postinitiation of treatment. Reliability was tested using Cronbach's coefficient α. Construct validity was tested, prior to therapy, using principal components factoring with varimax rotation. Predictive validity was tested using repeated measures analysis of variance (anova) of CES‐D scores at 4 and 24 weeks postinitiation of treatment. Results.
Non‐probability sample, 116 adult HCV patients [62 (53%) males and 54 (47%) females]. Reliability (Cronbach's α) = 0·88 pretreatment, 0·89 week 4 and 0·90 week 24. Construct validity testing revealed four factors: negative affect; positive affect; somatic; and depressed affect/somatic. Exception for two items, ‘felt sad’ and ‘couldn’t get going', all items loaded distinctly with correlation coefficients in the range of 0·51–0·84. Predictive validity testing revealed a statistically significant effect over time (P < 0·001) in the direction predicted (pretreatment x = 13·97; post 4 weeks x = 19·54 and 24 weeks x = 19·97). Conclusions.  The CES‐D is a reliable and valid instrument to screen for depressive symptoms in HCV patients. The instrument detected the predicted increase in depression associated with HCV. Examination of the sensitivity and specificity is needed to determine the most accurate cut‐off score.
Transforming loss: Taiwanese women's adaptation to stillbirth
Authors: Hsu Min‐Tao , Tseng Ying‐Fen , Kuo Ling‐Lih 
Published: March 2003

Aim.  To explore the experiences of Taiwanese mothers of stillborn babies, their coping strategies, and the ways in which their subsequent human interactions are shaped by Taiwanese culture. Background.  Giving birth to a male family heir is still considered an important responsibility for Taiwanese women. The ideology of continuity is still at the centre of Chinese family life in which women are expected to deliver babies that will continue their husbands' family lines. Research on the connection between this responsibility and women's reaction to stillbirth in a cultural context is limited. Understanding Taiwanese women's experiences with stillbirth will add to the body of nursing knowledge, especially in terms of giving culturally competent nursing care. Methods.  Interpretive ethnographic procedures were used to locate coping strategies. Twenty mothers who had stillbirth experiences were interviewed periodically during the 2 years following their losses. Following Agar's example, data were analysed to identify themes representing coping strategies. Findings.  The four major themes identified were (a) transforming the meaning of death, (b) doing something for the deceased, (c) anticipating another pregnancy, and (d) rebuilding a social fabric. Conclusion.  The processes that the mothers of stillborn babies experience represent transformations that involve engagement with cultural expectations for woman. The authors suggest that these cultural impacts should be incorporated into nursing assessment and treatment practices.
‘I’m still waiting...': barriers to accessing cardiac rehabilitation services
Authors: Tod A.M. , Lacey E.A. , McNeill F. 
Published: March 2003

Background.  The United Kingdom (UK) National Service Framework for coronary heart disease challenges health services to address existing problems regarding the quality and content of cardiac rehabilitation services. Concern also exists regarding inequalities in access to services. The South Yorkshire Coalfields Health Action Zone (SYCHAZ) funded this study to harness the views and experiences of staff and patients regarding existing services. The intention is to use the information gained to develop acceptable and accessible services for the future. Aims.  To explore what barriers exist for patients in accessing cardiac rehabilitation services within the South Yorkshire Coalfield locality. Ethical issues and approval.  Patients were identified and recruited with the assistance of staff responsible for their care. Informed consent was obtained prior to participation. Approval was obtained from the relevant Ethics Committees. Methods.  Qualitative methods were used, including semi‐structured interviews and Framework Analysis techniques. Purposive sampling was used to select participants. Instruments.  Semi‐structured individual interviews of 15 staff and 20 postmyocardial infarction patients. One group interview with seven health visitors and two with lay members of heart support groups. Outcomes.  Barriers to accessing cardiac rehabilitation. Results.  This study revealed a limited service capacity. Big gaps exist between patches of service activity that most patients appear to slip through. Problems in accessing the service were categorized into five themes: absence, waiting, communication, understanding, and appropriateness. Some groups fared worse in terms of access to services, for example women, the elderly and those in traditional working class coalfields communities. Professional and more affluent participants appeared better able to negotiate their way around the system by seeking out advice or ‘going private’. Limitations.  The omission of medical staff and ethnic minority patients. Conclusions.  Cardiac rehabilitation in the policy targets in UK will only be met with substantial investment to address the barriers identified here.
The essence of cancer care: the impact of training on nurses' ability to communicate effectively
Authors: Wilkinson Susie M. , Gambles Maureen , Roberts Anita 
Published: March 2003

Background.  The importance of effective communication between health professionals and patients with cancer is widely recognized. Training programmes aimed at improving key communication skills are becoming increasingly available. Purpose.  To evaluate a communication skills programme delivered to 308 cancer nurses as part of degree/diploma courses. Based on previous work, it was hypothesized that a statistically significant improvement between pre‐ and postintervention scores would be observed. Methods.  Audiotaped nursing assessments with patients were undertaken before and after the course. These were evaluated according to coverage of nine previously identified key areas of communication. Results.
Mean postcourse scores rose by 5·9 points (
P
< 0·001) to 16·3 (out of a possible 27). All nine individual areas of the assessment showed statistically significant improvements postintervention (
P  < 0·001). The areas showing most improvement were those with a high emotional content. Conclusions.  This study has demonstrated that an integrated approach to communication skills training has the potential to improve nurses' skills, particularly in emotionally laden areas across the spectrum of roles in cancer care.
Competition refuges and coexistence: an example from Serengeti carnivores
Authors: DURANT SARAH M. 
Published: March 2003

1.  In the last two decades predator–prey models have shown that ‘refuges’, in which prey can seek respite from predation, are crucial for the persistence of prey and predator. This concept is equally applicable to interspecific competition and, in a heterogeneous environment, species with low competitive ability should seek out ‘competition refuges’ where competition is reduced. 2.  Cheetahs have low competitive ability compared with their principal competitors, hyenas and lions, which are directly responsible for their low density. This study uses distribution data collected in the Serengeti National Park in Tanzania over a 4‐year period to show that cheetahs are more strongly associated with each other than with their competitors and utilize areas with low‐density prey. 3.  Cheetahs exhibit local avoidance behaviour in both space and time with respect to lions and hyenas. This behaviour is facultative and is strongest when cheetahs are engaged in activities that might expose them to food loss or increase the risk of close interactions, such as when they are hunting or eating. 4.  Lactating cheetahs, whose range is restricted, are more likely to have difficulties finding prey and come into more frequent contact with lions than free‐ranging animals. 5.  It is argued that although cheetahs always lose in direct competition, they persist in the ecosystem by seeking out ‘competition refuges’ with low densities of lions and hyenas and that their mobility is the key to their continued coexistence with these predators. This pattern of distribution may be generally applicable to other species which, although widely distributed, always occur at low densities.
Aerial distribution, flight behaviour and eggload: their inter‐relationship during dispersal by the sweetpotato whitefly
Authors: Isaacs Rufus , Byrne David N. 
Published: March 2003

1. The aerial distribution ofBemisia tabaciGennadius (the sweetpotato whitefly) was studied during the early ascent phase of flight, to test the degree to which dispersal patterns reflect the flight behaviour of individuals.2.Marked whiteflies were trapped at four heights between 0 and 7·2 m above fallow ground, and at six distances between 0 and 100 m from the insect source. Insects were trapped during a 2–3 h period after the initiation of flight activity during the summers of 1995 and 1996.3.Analysis of trap catch data revealed a clear negative exponential relationship between height and aerial distribution, and a slightly weaker negative power relationship between distance and aerial distribution. Marked insects were caught in the uppermost traps adjacent to the source, indicating that a portion of the population had a strong capacity for ascent out of the flight boundary layer.4.Eggload decreased with the height, but not the distance, at which whiteflies were trapped. Mean eggload close to the ground was significantly greater than that for those trapped at 4·8 and 7·2 m, supporting the hypothesis that there is a trade‐off between flight and oogenesis in weak‐flying insects.5.Air temperatures during the trapping periods were positively correlated with the proportion of male and femaleB. tabacicaught in the highest traps, but not in the most distant traps.6.The significance of these results for accurate prediction of whitefly dispersal is discussed, and the importance of individual's behaviour in determining dispersal patterns of small insects is emphasized.
Interference among insect parasitoids: a multi‐patch experiment
Authors: Visser Marcel E. , Jones T. Hefin , Driessen Gerard 
Published: March 2003

1. Interference among insect parasitoids leads to a reduction in the overall search rate (the population equivalent of searching efficiency) with increasing parasitoid population density. When this reduction is due to behavioural responses of individuals to increased intraspecific competition, interference can serve as a stepping stone from individual behaviour to population phenomena. 2. Interference can take different forms: (1) a direct within‐patch reduction of searching efficiency with parasitoid density (direct mutual interference); (2) a decrease in overall search rate with increasing parasitoid density if parasitoids have a non‐uniform distribution over patches where this distribution remains unaltered with increasing density (pseudo‐interference); (3a) a decrease in the time spent on patches by each individual, i.e. more or longer travelling at higher parasitoid densities; and (3b) a decrease in overall search rate due to a change in the distribution of parasitoid effort over patches with increasing parasitoid density. These last two forms arise from behavioural responses to increased parasitoid density and are forms of indirect mutual interference. 3. We present an expression for the overall search rate in a patchy environment where individual parasitoids travel between patches. We use this to show how the different forms of interference affect the overall search rate, contrasting environments with aggregated and uniform host distributions. 4. Using the data of Jones (1986) we explore the different forms of interference in a multipatch experiment. In these experiments, different numbers of parasitoids were introduced in an arena where the distribution of hosts over patches was either aggregated or uniform. We show that both pseudo‐interference and indirect mutual interference play a role, and that they have an opposite effect for a uniform host distribution, but amplify one another for aggregated host distributions. 5. The indirect mutual interference arises from a shift towards a more uniform distribution of parasitoid effort over patches with increasing parasitoid densities. This shift is caused by a behavioural response to parasitoid density, and is likely due to changes in the parasitoids’ patch arrival and departure decisions. These decisions underlie the distribution of time spent on patches, thereby linking individual behaviour to a phenomenon at the population level. 6. Finally, we put forward a more general framework for indirect mutual interference to also include behavioural responses in sex allocation, clutch size and host acceptance to parasitoid density as forms of interference.
Dynamics of a harvested moose population in a variable environment
Authors: Solberg Erling Johan , Saether Bernt‐Erik , Strand Olav , Loison Anne 
Published: March 2003

1.Population size, calves per female, female mean age and adult sex ratio of a moose (Alces alces) population in Vefsn, northern Norway were reconstructed from 1967 to 1993 using cohort analysis and catch‐at‐age data from 96% (6752) of all individuals harvested.2.The dynamics of the population were influenced mainly by density‐dependent harvesting, stochastic variation in climate and intrinsic variation in the age‐structure of the female segment of the population.3.A time delay in the assignment of hunting permits in relation to population size increased fluctuations in population size.4.Selective harvesting of calves and yearlings increased the mean age of adult females in the population, and, because fecundity in moose is strongly age‐specific, the number of calves per female concordantly increased. However, after years with high recruitment, the adult mean age decreased as large cohorts entered the adult age‐groups. This age‐structure effect generated cycles in the rate of recruitment to the population and fluctuations introduced time‐lags in the population dynamics.5.An inverse relationship between recruitment rate and population density, mediated by a density‐dependent decrease in female body condition, could potentially have constituted a regulatory mechanism in the dynamics of the population, but this effect was counteracted by a density‐dependent increase in the mean age of adult females.6.Stochastic variation in winter snow depth and summer temperature had delayed effects on recruitment rate and in turn population growth rate, apparently through effects on female body condition before conception.
Brood parasitism by the cuckoo on patchy reed warbler populations in Britain
Authors: Lindholm Anna K. 
Published: March 2003

1. Reed warblers are not known to be parasitized by cuckoos in Wales, and are rarely parasitized in some English populations, despite the presence of cuckoos. Nine hypotheses are proposed to explain regional differences in parasitism frequencies. They are tested against national and international data from the BTO, RSPB and EURING, and data from four study sites. 2. The frequency of parasitism of reed warbler populations was found to be negatively correlated with habitat patch size. Thus the frequency of parasitism experienced by reed warblers and the number of cuckoos parasitizing a reed warbler population do not increase in direct proportion to host abundance. 3. Population sizes of two unparasitized (Llangorse Lake and Oxwich) and one rarely parasitized population of reed warblers (Pannel Valley) are neither too large nor too small to be suitable for parasitism by cuckoos. 4. Cuckoos are not excluded from these populations by lack of perches in the habitat, because of a lack of prey in the immediate area, or by territorial competition with cuckoos of other host preferences. 5. There has been no decline in frequency of parasitism of reed warblers in Britain since 1932. Thus, reed warbler cuckoos are probably not declining in numbers and contracting their range away from these three geographically marginal sites. 6. Cuckoos parasitizing reed warbler populations at Llangorse Lake, Oxwich and Pannel Valley would achieve reproductive success equal to or higher than that attained with other local hosts, so that any host switches away from reed warblers would be unprofitable. 7. Reed warbler cuckoos may have dispersed to all or most of these study populations in the past. However, the cuckoo populations would have been small and highly vulnerable to extinction. Cycles of increases, declines and extinctions of local populations could explain the variance in parasitism frequencies and number of cuckoos often observed. 8. The most important factors considered in this study that affect the presence and number of cuckoos at a site appear to be competition between females, habitat patch size and structure, rates of dispersal and demographic stochasticity.
Structural change in an exploited fish community: a consequence of differential fishing effects on species with contrasting life histories
Authors: Jennings Simon , Greenstreet Simon. P. R. , Reynolds John. D. 
Published: March 2003

1.An understanding of the links between life histories and responses to exploitation could provide the basis for predicting shifts in community structure by identifying susceptible species and linking life‐history tactics with population dynamics.2.We examined long‐term trends in the abundance of species in the North Sea bottom‐dwelling (demersal) fish community. Between 1925 & 1996 changes in species composition led to an increase in mean growth rate, while mean maximum size, age at maturity and size at maturity decreased. The demersal fish community was increasingly heavily fished during this period.3.Trends in mean life‐history characteristics of the community were linked to trends in abundance of component species. An approach based on phylogenetic comparisons was used to examine the differential effects of fishing on individual species with contrasting life histories.4.Those species that decreased in abundance relative to their nearest relative, matured later at a greater size, grew more slowly towards a greater maximum size and had lower rates of potential population increase. The phylogenetically based analyses demonstrated that trends in community structure could be predicted from the differential responses of related species to fishing.5.This is the first study to link exploitation responses of an entire community to the life histories of individual species. The results demonstrate that fishing has greater effects on slower growing, larger species with later maturity and lower rates of potential population increase. The comparative approach provides a basis for predicting structural change in other exploited communities.
The intra‐ and interspecific relationships between abundance and distribution in helminth parasites of birds
Authors: Poulin Robert 
Published: March 2003

1.Positive correlations between local abundance and distribution on a larger spatial scale are commonly observed among related species.2.Within parasite species, the same relationship may be expected between prevalence and intensity of infection across host species used. Across parasite species, a positive relationship is expected between average abundance in a host population and the number of host species that can be exploited based on the resource breadth hypothesis. Trade‐offs between the ability to exploit many host species and the potential for heavy infections, however, could result in a negative relationship.3.Intraspecifically, using data on 51 helminth species parasitic in birds, prevalence and intensity of infection among host species used are generally only weakly correlated. Only in nematodes is there an overall positive relationship between prevalence and intensity.4.A comparative analysis was performed on data from 389 species of cestodes, trematodes and nematodes parasitic in birds to determine how host specificity covaries interspecifically with abundance, measured both as prevalence and intensity of infection.5.After controlling for phylogenetic influences and sampling effort, the number of host species used correlated positively with prevalence in all three parasite taxa, and with intensity of infection in trematodes only.6.These results do not support the existence of a trade‐off between abundance and the use of many host species, as has been found for fish parasites. Instead, whatever makes helminth parasites of birds abundant within a host population may facilitate their successful colonization of new host species.
Scaling of metabolic rate with body mass and temperature in teleost fish
Authors: Clarke Andrew , Johnston Nadine M. 
Published: March 2003

Summary1.We examined published studies relating resting oxygen consumption to body mass and temperature in post‐larval teleost fish. The resulting database comprised 138 studies of 69 species (representing 28 families and 12 orders) living over a temperature range ofc.40 °C.2. Resting metabolic rate (Rb; mmol oxygen gas h–1) was related to body mass (M;wet mass, g) byRb = aMb, where a is a constant and b the scaling exponent. The model was fitted by least squares linear regression after logarithmic transformation of both variables. The mean value of scaling exponent, b, for the 69 individual species was 0·79 (SE 0·11). The general equation for all teleost fish was 1nRb = 0·80(1nM) – 5·43.3. The relationship between resting oxygen consumption and environmental temperature for a 50‐g fish was curvilinear. A typical tropical fish at 30°C requires approximately six times as much oxygen for resting metabolism as does a polar fish at 0°C. This relationship could be fitted by several statistical models, of which the Arrhenius model is probably the most appropriate. The Arrhenius model for the resting metabolism of 69 species of teleost fish, corrected to a standard body mass of 50 g, was 1nRb = 15·7 – 5·02.T–1, whereTis absolute temperature (103 × K).4.The Arrhenius model fitted to all 69 species exhibited a lower thermal sensitivity of resting metabolism (mean Q10 = 1·83 over the range 0–30 °C) than typical within‐species acclimation studies (median Q10 = 2·40,n = 14). This suggests that evolutionary adaptation has reduced the overall thermal sensitivity of resting metabolism across species. Analysis of covariance indicated that the relationships between resting metabolic rate and temperature for various taxa (orders) showed similar slopes but significantly different mean rates.5. Analysis of the data for perciform fish provided no support for metabolic cold adaptation (the hypothesis that polar fish show a resting metabolic rate higher than predicted from the overall rate/temperature relationship established for temperate and tropical species).6. Taxonomic variation in mean resting metabolic rate showed no relationship to phylogeny, although the robustness of this conclusion is constrained by our limited knowledge of fish evolutionary history.