bluuebunny/crossref_metadata_2025 huggingface dataset:
Warming and nitrogen affect size structuring and density dependence in a host–parasitoid food web
Authors: de Sassi Claudio , Staniczenko Phillip P. A. , Tylianakis Jason M.
Published: September 2012

Body size is a major factor constraining the trophic structure and functioning of ecological communities. Food webs are known to respond to changes in basal resource abundance, and climate change can initiate compounding bottom-up effects on food-web structure through altered resource availability and quality. However, the effects of climate and co-occurring global changes, such as nitrogen deposition, on the density and size relationships between resources and consumers are unknown, particularly in host–parasitoid food webs, where size structuring is less apparent. We use a Bayesian modelling approach to explore the role of consumer and resource density and body size on host–parasitoid food webs assembled from a field experiment with factorial warming and nitrogen treatments. We show that the treatments increased resource (host) availability and quality (size), leading to measureable changes in parasitoid feeding behaviour. Parasitoids interacted less evenly within their host range and increasingly focused on abundant and high-quality (i.e. larger) hosts. In summary, we present evidence that climate-mediated bottom-up effects can significantly alter food-web structure through both density- and trait-mediated effects.
Novel communities from climate change
Authors: Lurgi Miguel , López Bernat C. , Montoya José M.
Published: September 2012

Climate change is generating novel communities composed of new combinations of species. These result from different degrees of species adaptations to changing biotic and abiotic conditions, and from differential range shifts of species. To determine whether the responses of organisms are determined by particular species traits and how species interactions and community dynamics are likely to be disrupted is a challenge. Here, we focus on two key traits: body size and ecological specialization. We present theoretical expectations and empirical evidence on how climate change affects these traits within communities. We then explore how these traits predispose species to shift or expand their distribution ranges, and associated changes on community size structure, food web organization and dynamics. We identify three major broad changes: (i) Shift in the distribution of body sizes towards smaller sizes, (ii) dominance of generalized interactions and the loss of specialized interactions, and (iii) changes in the balance of strong and weak interaction strengths in the short term. We finally identify two major uncertainties: (i) whether large-bodied species tend to preferentially shift their ranges more than small-bodied ones, and (ii) how interaction strengths will change in the long term and in the case of newly interacting species.
Linking community size structure and ecosystem functioning using metabolic theory
Authors: Yvon-Durocher Gabriel , Allen Andrew P.
Published: September 2012

Understanding how biogeochemical cycles relate to the structure of ecological communities is a central research question in ecology. Here we approach this problem by focusing on body size, which is an easily measured species trait that has a pervasive influence on multiple aspects of community structure and ecosystem functioning. We test the predictions of a model derived from metabolic theory using data on ecosystem metabolism and community size structure. These data were collected as part of an aquatic mesocosm experiment that was designed to simulate future environmental warming. Our analyses demonstrate significant linkages between community size structure and ecosystem functioning, and the effects of warming on these links. Specifically, we show that carbon fluxes were significantly influenced by seasonal variation in temperature, and yielded activation energies remarkably similar to those predicted based on the temperature dependencies of individual-level photosynthesis and respiration. We also show that community size structure significantly influenced fluxes of ecosystem respiration and gross primary production, particularly at the annual time-scale. Assessing size structure and the factors that control it, both empirically and theoretically, therefore promises to aid in understanding links between individual organisms and biogeochemical cycles, and in predicting the responses of key ecosystem functions to future environmental change.
Clinical Outcomes of Extreme Lateral Interbody Fusion in the Treatment of Adult Degenerative Scoliosis
Authors: Caputo Adam M. , Michael Keith W. , Chapman Todd M. , Massey Gene M. , Howes Cameron R. , Isaacs Robert E. , Brown Christopher R.
Published: September 2012

Introduction. The use of extreme lateral interbody fusion (XLIF) and other lateral access surgery is rapidly increasing in popularity. However, limited data is available regarding its use in scoliosis surgery. The objective of this study was to evaluate the clinical outcomes of adults with degenerative lumbar scoliosis treated with XLIF.Methods. Thirty consecutive patients with adult degenerative scoliosis treated by a single surgeon at a major academic institution were followed for an average of 14.3 months. Interbody fusion was completed using the XLIF technique with supplemental posterior instrumentation. Validated clinical outcome scores were obtained on patients preoperatively and at most recent follow-up. Complications were recorded.Results. The study group demonstrated improvement in multiple clinical outcome scores. Oswestry Disability Index scores improved from 24.8 to 19.0 (P < 0.001). Short Form-12 scores improved, although the change was not significant. Visual analog scores for back pain decreased from 6.8 to 4.6 (P < 0.001) while scores for leg pain decreased from 5.4 to 2.8 (P < 0.001). A total of six minor complications (20%) were recorded, and two patients (6.7%) required additional surgery.Conclusions. Based on the significant improvement in validated clinical outcome scores, XLIF is effective in the treatment of adult degenerative scoliosis.
Renal function‐dependent association of serum uric acid with metabolic syndrome and hepatic fat content in a middle‐aged and elderly Chinese population
Authors: Xia Ming‐Feng , Lin Huan‐Dong , Li Xiao‐Ming , Yan Hong‐Mei , Bian Hua , Chang Xin‐Xia , He Wan‐Yuan , Jeekel Johannes , Hofman Albert , Gao Xin
Published: September 2012

The effect of uric acid (UA) on the pathogenesis of metabolic disorders is highly dependent on its physicochemical properties, and hyperuricaemia associated with different conditions may have different clinical meanings. The aim of the present study was to investigate the association of serum UA levels with metabolic syndrome and non‐alcoholic fatty liver disease (NAFLD) in a middle‐aged and elderly population with normal and impaired renal function.

The cross‐sectional study was performed on 1141 participants (426 men, 715 women; mean age 62 years) enrolled from the Shanghai Changfeng community. Each participant underwent a standard interview, with anthropometric and laboratory measurements. Hepatic fat content (HFC) was determined by a newly established quantitative ultrasound method.

Univariate correlation analysis showed that serum UA was associated with all components of metabolic syndrome and HFC (r = 0.193, P < 0.001), especially in participants with a normal estimated glomerular filtration rate (eGFR; r = 0.255, P < 0.001). Logistic regression analysis demonstrated an independent association of serum UA with metabolic syndrome and NAFLD in participants with normal renal function, but not in those with eGFR < 90 mL/min per 1.73 m2. Furthermore, multivariate linear analysis showed that UA levels were independently associated with HFC (P = 0.003), but only in participants with normal eGFR.

Elevated serum UA is independently associated with metabolic syndrome and NAFLD in patients with normal renal excretory function. However, in those with renal insufficiency, hyperuricaemia has no association with metabolic disorders.
Applying various algorithms for species distribution modelling
Authors: LI Xinhai , WANG Yuan
Published: September 2012

Species distribution models have been used extensively in many fields, including climate change biology, landscape ecology and conservation biology. In the past 3 decades, a number of new models have been proposed, yet researchers still find it difficult to select appropriate models for data and objectives. In this review, we aim to provide insight into the prevailing species distribution models for newcomers in the field of modelling. We compared 11 popular models, including regression models (the generalized linear model, the generalized additive model, the multivariate adaptive regression splines model and hierarchical modelling), classification models (mixture discriminant analysis, the generalized boosting model, and classification and regression tree analysis) and complex models (artificial neural network, random forest, genetic algorithm for rule set production and maximum entropy approaches). Our objectives are: (i) to compare the strengths and weaknesses of the models, their characteristics and identify suitable situations for their use (in terms of data type and species–environment relationships) and (ii) to provide guidelines for model application, including 3 steps: model selection, model formulation and parameter estimation.
Comparative sensitivity to environmental variation and human disturbance of Asian tapirs (Tapirus indicus) and other wild ungulates in Thailand
Authors: LYNAM Antony J. , TANTIPISANUH Naruemon , CHUTIPONG Wanlop , NGOPRASERT Dusit , BAKER Megan C. , CUTTER Passanan , GALE George , KITAMURA Shumpei , STEINMETZ Robert , SUKMASUANG Ronglarp , THUNHIKORN Somying
Published: September 2012

Southeast Asia's tropical forests suffer the highest rates of deforestation and disturbance of any on Earth, with poorly understood impacts on native fauna. Asian tapirs (Tapirus indicus) are among the least studied of the large mammals in these forests. Using records from 9 camera trap surveys in 7 of the largest (>1000 km2) protected area complexes, we assessed the influence of environmental variation and human‐induced disturbance on tapir occurrence. Tapirs were detected at 13% of locations sampled, significantly associated with evergreen forest (P < 0.001). A multiple logistic regression model predicted tapir presence 87% of the time. According to this model, tapir occurrence was positively influenced by annual rainfall and proximity to the forest edge. However, tapirs may not avoid edges but instead prefer wetter evergreen forest, a habitat type that tended to occur further from the forest edge at higher elevations in our particular study sites (P < 0.001). By comparison, 4 other wild ungulate species that share habitats with tapirs showed a range of differing responses. Tapirs are expected to be less sensitive to disturbance because they are not targets for hunting and trade, and are almost entirely active at night, so avoid peak traffic periods in parks. Tapir populations in Thailand may be more stable than in other parts of their global range because rates of forest loss have decreased >40% over the past 20 years. We recommend surveys to fill gaps in the understanding of the status in lesser‐known protected areas, research to better understand the fine‐scale environmental influences on behavior and habitats of tapirs, and other forest ungulates, and continued legal status for tapirs in the highest category of protection.
Blue sheep in the Annapurna Conservation Area, Nepal: habitat use, population biomass and their contribution to the carrying capacity of snow leopards
Authors: ARYAL Achyut , BRUNTON Dianne , JI Weihong , RAUBENHEIMER David
Published: September 2012

The Himalaya region of Nepal provides a habitat for the endangered snow leopard (Panthera uncia) and its principal prey species, the blue sheep (Pseudois nayaur). The aim of this study was to describe the habitat, the distribution and the population structure of blue sheep, and to estimate their contribution to the carrying capacity of snow leopard in the upper Mustang region of Nepal. Blue sheep were recorded at altitudes from 3209–5498 m on slopes with gradients of 16–60° and aspects of 40°NE to 140°SE. A total of 939 blue sheep were counted in the upper Mustang region, and 98 were counted in the Yak Kharka region of Manang district; however, upper Mustang had the lowest population density of blue sheep recorded within their distribution range in Nepal (0.86 blue sheep/km2). The results of the study show that a higher density of blue sheep is associated with greater plant species diversity. The most important species present in the blue sheep habitat wereKobresia pygmaea,Artemesiaspp.,Loniceraspp.,Lancea tibetica,Poaspp.,Astragalusspp. andEphedra gerardiana. It is estimated that the existing blue sheep population biomass of approximately 38 925 kg in the upper Mustang region could support approximately 19 snow leopards (1.6 snow leopards/100 km2).
Thromboprophylaxis prescribing and thrombotic event rates in multiple myeloma patients treated with lenalidomide or thalidomide at a specialist cancer hospital
Authors: Alexander Marliese , Teoh Khai C , Lingaratnam Senthil , Kirsa Sue , Mellor James D
Published: September 2012

Aim

To assess thromboprophylaxis prescribing patterns against current guidelines and report thromboembolism (TE) incidence in multiple myeloma (MM) patients treated with thalidomide (thal) or lenalidomide (len) at a specialist cancer hospital over a one‐year period.

Method

Dispensing records of thal and len, diagnosis of MM, patients’ characteristics, disease status, co‐prescribed medicines including thromboprophylaxis and incidence of TE were extracted from patients’ records and a patient survey conducted to identify patients who sourced thromboprophylactic medicines outside the hospital.

Results

Enoxaparin was most the commonly prescribed thromboprophylactic agent (43%), followed by low‐dose aspirin (26%) and therapeutic warfarin (6%). The thromboprophylactic strategy (including no prophylaxis) could not be determined for 22% of patients. TE incidence (with any thromboprophylaxis) was 9.3 and 9.1% in thal‐based and len‐based regimens, respectively.

Conclusion

Both aspirin and enoxaparin thromboprophylaxis were prescribed for patients on both low‐risk and high‐risk immunomodulatory drug‐based regimens, deviating from current consensus guidelines. Treatment of comorbidities constituted the rationale for maintenance on therapeutic warfarin. Fixed low‐dose warfarin was not prescribed. TE event rates (with any thromboprophylaxis) were consistent with those reported in the literature. Documentation of a chosen strategy was lacking for nearly a quarter of patients, resulting in uncertainty of treatment plan for other members of the multidisciplinary treating team. Centers need to work towards evidence‐based institutional guidelines and improving documentation practices for thromboprophylaxis in their MM patients.
When is azoospermic infertility treatable without intracytoplasmic sperm injection?
Authors: McLachlan Robert I.
Published: September 2012

Infertility with azoospermia requires a diligent search for reversible factors and treatment to restore natural fertility, even though most cases are due to untreatable primary spermatogenic failure and are destined to require consideration of assisted reproductive treatment (ART) options. Complete clinical and diagnostic evaluation is essential for avoiding both unnecessary ART and overlooking important co‐morbidities. Gonadotrophin deficiency is the most treatable cause, resulting from drug effects or congenital or acquired disease, and medical therapy is highly efficacious. A range of uncommon endocrinocrinopathies may also result in reversible azoospermia. Finally, obstructive azoospermia may be surgically remediable in selected cases.
Comparison of the overnight metyrapone and glucagon stimulation tests in the assessment of secondary hypoadrenalism
Authors: Cegla Jaimini , Jones Ben , Seyani Lata , Papadoulou Deborah , Wynne Katie , Martin Niamh M. , Meeran Karim , Chapman Richard , Donaldson Mandy , Goldstone Anthony P. , Tan Tricia
Published: September 2012

Objective

The insulin tolerance test (ITT) is contraindicated in a proportion of patients with suspected ACTH deficiency. The aim of this study was to investigate the diagnostic accuracy of the glucagon stress test (GST) compared with the overnight metyrapone test (OMT) in patients with contraindications to ITT.

Design

This was a prospective comparison of the GST to the OMT in patients with suspected ACTH deficiency and contraindications to the ITT. The OMT was used as the standard for comparison. The study was conducted at two tertiary referral centres for pituitary disease.

Patients

Seventy‐eight patients underwent contemporaneous OMT and GST of whom 61 had sufficient suppression of cortisol during the OMT to be included in the comparison. Forty had suffered traumatic brain injury, 36 had organic pituitary disorders and two were classified as ‘other’.

Measurements

ACTH sufficiency was defined as 0800h 11‐deoxycortisol ≥ 200 nmol/l on OMT and peak cortisol ≥ 440 nmol/l on GST, as per local reference ranges.

Results

There was significant discrepancy between the proportion of patients diagnosed with ACTH deficiency using the OMT (39%) and GST (89%). From our data, a GST peak cortisol cut‐off of ≥350 nm provides the combination of optimal sensitivity (71%) and specificity (57%), compared with a higher sensitivity (88%) but poor specificity (11%) using a cut‐off of ≥440 nm.

Conclusions

The GST should be used with caution as a diagnostic test of ACTH reserve. The OMT should be used in preference to the GST to assess the hypothalamic pituitary adrenal axis where ITT is contraindicated.
Glucocorticoid treatment regimen and health outcomes in adults with congenital adrenal hyperplasia
Authors: Han T. S. , Stimson R. H. , Rees D. A. , Krone N. , Willis D. S. , Conway G. S. , Arlt W. , Walker B. R. , Ross R. J. ,   United Kingdom Congenital adrenal Hyperplasia Adult Study Executive (CaHASE)
Published: September 2012

Background

Adults with congenital adrenal hyperplasia (CAH) are treated with a wide variety of glucocorticoid treatment regimens.

Objective, design and methods

To test whether drug dose and timing of glucocorticoid treatment regimen impacts on health outcomes. This was a cross‐sectional study of 196 adult CAH patients in whom treatment and health outcomes were measured. Glucocorticoid dose was converted to prednisolone dose equivalent (PreDEq) using three published formulae. Associations between the type of glucocorticoid regimen and PreDEq with specific health outcome variables were tested using partial correlation and principal components analysis (PCA).

Results

Patients on dexamethasone had lower androgens and ACTH but greater insulin resistance compared with those receiving hydrocortisone or prednisolone. Dexamethasone dose and once daily administration were associated with insulin resistance. Partial correlation analysis adjusted for age and sex showed PreDEq weakly correlated (r < 0·2) with blood pressure and androstenedione. Mutation severity was associated with increased PreDEq (F3,141 = 4·4, P < 0·01). In PCA, 3 PCs were identified that explained 62% of the total variance (r2) in observed variables. Regression analysis (age and sex adjusted) confirmed that PC2, reflecting disease control (androstenedione, 17‐hydroxypregesterone and testosterone), and PC3, reflecting blood pressure and mutations (systolic and diastolic blood pressure and mutation severity), related directly to PreDEq (r2 = 23%, P < 0·001).

Conclusions

In adults with congenital adrenal hyperplasia, dexamethasone use was associated with lower androgens but greater insulin resistance, and increasing glucocorticoid dose associated with increased blood pressure, poor disease control and mutation severity.
A Double‐Edged Sword with Therapeutic Potential: An Updated Role of Autophagy in Ischemic Cerebral Injury
Authors: Wei Kai , Wang Pei , Miao Chao‐Yu
Published: September 2012

Cerebral ischemia is a severe outcome that could cause cognitive and motor dysfunction, neurodegenerative diseases and even acute death. Although the existence of autophagy in cerebral ischemia is undisputable, the consensus has not yet been reached regarding the exact functions and influence of autophagy in cerebral ischemia. Whether the activation of autophagy is beneficial or harmful in cerebral ischemia injury largely depends on the balance between the burden of intracellular substrate targeted for autophagy and the capacity of the cellular autophagic machinery. Furthermore, the mechanisms underlying the autophagy in cerebral ischemia are far from clear yet. This brief review focuses on not only the current understanding of biological effects of autophagy, but also the therapeutic potentials of autophagy in ischemic stroke. There are disputes over the exact role of autophagy in cerebral ischemia. Application of chemical autophagy inhibitor (e.g., 3‐methyladenine) or inducer (e.g., rapamycin) in vitro and in vivo was reported to protect or harm neuronal cell. Knockdown of autophagic protein, such as Beclin 1, was also reported to modulate the cerebral ischemia‐induced injury. Moreover, autophagy inhibitor abolished the neuroprotection of ischemic preconditioning, implying a neuroprotective effect of autophagy. To clarify these issues on autophagy in cerebral ischemia, future investigations are warranted.
MAINTENANCE GOALS IN INTELLIGENT AGENTS
Authors: Duff Simon , Thangarajah John , Harland James
Published: September 2012

Intelligent agent systems are often used to implement complex software systems. A key aspect of agent systems is goals: a programmer or user defines a set of goals for an agent, and then the agent is left to determine how best to satisfy the goals assigned to it. Such goals include both achievement goals and maintenance goals. An achievement goal describes a particular state the agent would like to become true, such as being in a particular location or having a particular bank balance. A maintenance goal specifies a condition which is to be kept satisfied, such as ensuring that a vehicle stays below a certain speed, or that it has sufficient fuel. Current agent systems usually only utilize reactive maintenance goals, in that the agent only takes action after the maintenance condition has been violated. In this paper, we discuss methods by which maintenance goals can be made proactive, i.e., acting before a maintenance condition is violated, having predicted that the maintenance condition will be violated in the future. We provide a representation of proactive maintenance goals, reasoning algorithms, an operational semantics that realizes these algorithms and an experimental evaluation of our approach.
The dynamics of death in melanoma
Authors: Vollmer Robin T.
Published: September 2012

Background

Melanoma has been recently characterized as an over‐diagnosed tumor, and some have suggested that the ‘epidemic’ in melanoma is spurious. Nevertheless, a fraction of melanoma patients continue to die of this tumor. For any tumor, the hazard function provides information about the timing and intensity of fatalities, and to examine the details of fatality in melanoma, herein the hazard functions for melanoma are derived and examined.

Methods

Data for this study came from the SEER data base, from AJCC data and from previously published studies of melanoma, and the hazard function was derived using the sum of two gamma functions and a nonlinear least‐squares fitting algorithm.

Results

The derived hazard functions for melanoma peak at 1–3 years, a result that implies a form of rapidly evolving and fatal melanoma that is not consistently identified by routine prognostic factors. Yet in recent years the hazard function for all melanomas has declined suggesting that much of the epidemic in melanoma is due to non‐fatal tumors.

Conclusion

Analyses of the hazard functions in a large number of melanoma patients has uncovered details about the dynamics of death that otherwise are not apparent.
Dermatopathology of the foreskin: an institutional experience of over 400 cases
Authors: West Dava S. , Papalas John A. , Selim Maria A. , Vollmer Robin T.
Published: September 2012

Background

Diseases of the foreskin may manifest with an array of pathologic findings, including potentially under‐recognized dermatologic conditions. Herein, we summarize an institutional experience in foreskin dermatopathology.

Methods

Diagnoses rendered on foreskin specimens between 1982 and April 2009 were obtained through a computer‐based keyword search. Cases given normal, non‐specific or descriptive diagnoses were reviewed by a dermatopathologist.

Results

Keyword search yielded 414 foreskin diagnoses. Interpretations included normal foreskin (n = 131), benign lesions (n = 262) and malignant/dysplastic entities (n = 21). Of 353 cases given normal, descriptive or non‐specific diagnoses, 334 were reviewed. Of reviewed cases, 209 (63%) were given more specific diagnoses [e.g. spongiotic dermatitis (n = 115), lichen sclerosus et atrophicus (LSA; n = 41), interface/lichenoid dermatitis (n = 26), psoriasiform dermatitis (n = 7)]. Discrepancy between the clinical and pathologic impression was frequently noted (n = 77).

Conclusions

This study shows benign inflammatory lesions represent the most frequent foreskin pathology. When possible, specific diagnoses should be rendered, as accurate classification may be of clinical importance. There is an abundance of recent literature on the role of circumcision in disease prevention, and this topic is explored. We discuss the theoretical possibility that foreskin inflammation compromises the mucosal/epithelial barrier, thus playing a role in disease transmission.
Recent decline in suitable environmental conditions for African great apes
Authors: Junker Jessica , Blake Stephen , Boesch Christophe , Campbell Geneviève , Toit Louwrens du , Duvall Chris , Ekobo Atanga , Etoga Gilles , Galat‐Luong Anh , Gamys Joel , Ganas‐Swaray Jessica , Gatti Sylvain , Ghiurghi Andrea , Granier Nicolas , Hart John , Head Josephine , Herbinger Ilka , Hicks Thurston Cleveland , Huijbregts Bas , Imong Inaoyom S. , Kuempel Noëlle , Lahm Sally , Lindsell Jeremy , Maisels Fiona , McLennan Matthew , Martinez Laura , Morgan Bethan , Morgan David , Mulindahabi Felix , Mundry Roger , N'Goran Kouamé Paul , Normand Emmanuelle , Ntongho Anne , Okon David Tiku , Petre Charles‐Albert , Plumptre Andrew , Rainey Hugo , Regnaut Sébastien , Sanz Crickette , Stokes Emma , Tondossama Adama , Tranquilli Sandra , Sunderland‐Groves Jacqueline , Walsh Peter , Warren Ymke , Williamson Elizabeth A. , Kuehl Hjalmar S.
Published: September 2012

Aim

To predict the distribution of suitable environmental conditions (SEC) for eight African great ape taxa for a first time period, the 1990s and then project it to a second time period, the 2000s; to assess the relative importance of factors influencing SEC distribution and to estimate rates of SEC loss, isolation and fragmentation over the last two decades.

Location

Twenty‐two African great ape range countries.

Methods

We extracted 15,051 presence localities collected between 1995 and 2010 from 68 different areas surveyed across the African ape range. We combined a maximum entropy algorithm and logistic regression to relate ape presence information to environmental and human impact variables from the 1990s with a resolution of 5 × 5 km across the entire ape range. We then made SEC projections for the 2000s using updated human impact variables.

Results

Total SEC area was approximately 2,015,480 and 1,807,653 km2 in the 1990s and 2000s, respectively. Loss of predicted SEC appeared highest for Cross River gorillas (−59%), followed by eastern gorillas (−52%), western gorillas (−32%), bonobos (−29%), central chimpanzees (−17%) and western chimpanzees (−11%). SEC for Nigeria‐Cameroon chimpanzees and eastern chimpanzees was not greatly reduced. Except for Cross River and eastern gorillas, the number of SEC patches did not change significantly, suggesting that SEC loss was caused mainly by patch size reduction.

Main conclusions

The first continent‐wide perspective of African ape SEC distribution shows dramatic declines in recent years. The model has clear limitations for use at small geographic scales, given the quality of available data and the coarse resolution of predictions. However, at the large scale it has potential for informing international policymaking, mitigation of resource extraction and infrastructure development, as well as for spatial prioritization of conservation effort and evaluating conservation effectiveness.
Relationship of selection criteria to subsequent academic performance in an Australian undergraduate dental school
Authors: Mercer A. , Abbott P. V. , Puddey I. B.
Published: September 2012

In 1998, in addition to previous academic achievement, an aptitude test (UMAT) and a structured interview were introduced into selection for the Bachelor of Dental Science (BDSc), the undergraduate dental course at the University of Western Australia. The aim of this study was to determine the relationship between the combination of school‐leaver dental students' entry scores, some demographic characteristics and subsequent student performance in the undergraduate course. Three hundred and ninety‐eight school‐leavers who enrolled in the BDSc from 1999 through 2011 were studied. Regression models were constructed comprising entry scores, gender and age as predictors in relation to subsequent academic performance. The main outcome measure was the weighted average mark (WAM) for each of five academic year levels as well as results in specific units, defined as either ‘knowledge’ based or ‘clinically’ based. Of the variables studied, previous academic performance and female gender had the strongest relationship with yearly WAM for Years 1 through 4 and for both ‘knowledge’ based and ‘clinically’ based units. The interview score showed a strong relationship in the major clinical years and in a range of ‘clinically’ based units. UMAT scores were less consistent in relationship to WAM. These results support assessment through a highly structured interview together with prior academic achievement as an evidence‐based approach to selection of students for this undergraduate dental course.
Emergent effects of multiple predators on prey survival: the importance of depletion and the functional response
Authors: McCoy Michael W. , Stier Adrian C. , Osenberg Craig W.
Published: September 2012

The combined effects of multiple predators often cannot be predicted from their independent effects. Emergent multiple predator effects (MPEs) include risk enhancement, where combined predators kill more prey than predicted by their individual effects, and risk reduction, where fewer prey are killed than predicted. Current methods for detecting MPEs are biased because they assume linear functional responses and/or no prey depletion. As a result, past studies overestimated the occurrence of risk enhancement for additive designs, and tended to overestimate the occurrence of risk reduction for substitutive designs. Characterising the predators' functional responses and accounting for prey depletion reduces biases in detection, estimation, interpretation and generalisation of the emergent effects of predator diversity on prey survival. These findings have implications beyond MPE's and should be considered in all studies aimed at understanding how multiple factors combine when demographic rates are density dependent.
Methane emissions from rice paddies natural wetlands, lakes in China: synthesis new estimate
Authors: Chen Huai , Zhu Qiu'an , Peng Changhui , Wu Ning , Wang Yanfen , Fang Xiuqin , Jiang Hong , Xiang Wenhua , Chang Jie , Deng Xiangwen , Yu Guirui
Published: September 2012

Sources of methane (CH4) become highly variable for countries undergoing a heightened period of development due to both human activity and climate change. An urgent need therefore exists to budget key sources of CH4, such as wetlands (rice paddies and natural wetlands) and lakes (including reservoirs and ponds), which are sensitive to these changes. For this study, references in relation to CH4 emissions from rice paddies, natural wetlands, and lakes in China were first reviewed and then reestimated based on the review itself. Total emissions from the three CH4 sources were 11.25 Tg CH4 yr−1 (ranging from 7.98 to 15.16 Tg CH4 yr−1). Among the emissions, 8.11 Tg CH4 yr−1 (ranging from 5.20 to 11.36 Tg CH4 yr−1) derived from rice paddies, 2.69 Tg CH4 yr−1 (ranging from 2.46 to 3.20 Tg CH4 yr−1) from natural wetlands, and 0.46 Tg CH4 yr−1 (ranging from 0.33 to 0.59 Tg CH4 yr−1) from lakes (including reservoirs and ponds). Plentiful water and warm conditions, as well as its large rice paddy area make rice paddies in southeastern China the greatest overall source of CH4, accounting for approximately 55% of total paddy emissions. Natural wetland estimates were slightly higher than the other estimates owing to the higher CH4 emissions recorded within Qinghai‐Tibetan Plateau peatlands. Total CH4 emissions from lakes were estimated for the first time by this study, with three quarters from the littoral zone and one quarter from lake surfaces. Rice paddies, natural wetlands, and lakes are not constant sources of CH4, but decreasing ones influenced by anthropogenic activity and climate change. A new progress‐based model used in conjunction with more observations through model‐data fusion approach could help obtain better estimates and insights with regard to CH4 emissions deriving from wetlands and lakes in China.
The importance of nest‐site and habitat in egg recognition ability of potential hosts of theCommonCuckooCuculus canorus
Authors: Martín‐Vivaldi Manuel , Soler Juan José , Møller Anders Pape , Pérez‐Contreras Tomás , Soler Manuel
Published: September 2012

The intensity of selection exerted by brood parasites on their hosts depends on the proportion of nests that are parasitized and the fitness costs of parasitism. Nest detection by brood parasites influences the probability of parasitism, and we propose that the difficulty faced by brood parasites of finding nests on the ground may make ground‐nesting species subject to lower levels of parasitism, causing a reduction in levels of defence compared with species breeding in shrubs, trees and elsewhere above the ground. We tested the prediction that the rejection rate ofCommonCuckooCuculus canoruseggs by hosts is inversely related to the frequency with which they build nests on the ground, both at local and at continental scales. First, we used estimates of the rejection rate of non‐mimetic model eggs experimentally introduced into the nests of 26 potential host species breeding in theSierraNevadaMountains of southernSpain. Most species tested in theSierraNevada showed high rejection rates of both mimetic and non‐mimetic eggs, whereas theEuropeanRobinErithacus rubecula, with a low rejection rate, was the only species that was regularly parasitized. At the continental scale we used all available published information on rejection rates of non‐mimetic models by European hosts of theCommonCuckoo. The frequency of ground‐nesting explained interspecific variation in rejection rate of non‐mimetic model eggs both for the species tested in theSierraNevada and for allEuropean hosts after controlling for all other life‐history variables known to affect rejection rates. An effect of the abundance of trees in a particular habitat, previously shown to affect parasitism by theCommonCuckoo, was only apparent from analyses of continental‐scale data and not from theSierraNevada mountains, suggesting that particular properties of mountainous areas affectCommonCuckoo parasitism. Ground‐nesting species showed lower rejection rates than species breeding in bushes or trees. These results suggest that species nesting on the ground may have suffered lower parasitism pressures in their historical coevolutionary interactions with theCommonCuckoo.
Prevention of influenza among travellers attending at a UK travel clinic: beliefs and perceptions. A cross‐sectional study
Authors: Masuet‐Aumatell Cristina , Toovey Stephen , Zuckerman Jane N.
Published: September 2012

Please cite this paper as: Masuet‐Aumatell et al. (2012) Prevention of influenza among travellers attending at a UK travel clinic: beliefs and perceptions. A cross‐sectional study. Influenza and Other Respiratory Viruses 7(4), 574–583.

Background  Travellers’ compliance with measures to prevent influenza through the use of antivirals and influenza vaccine remains very poor despite influenza being one of the commonest travel and vaccine‐preventable diseases. A study was undertaken to assess travellers’ beliefs, perceptions and intentions to take antivirals for the treatment and prevention of influenza during the H1N1 pandemic.

Methods  A cross‐sectional survey (n = 96) of travellers who attended the Royal Free Travel Health Centre, London, UK was undertaken in September 2009. A self‐administered questionnaire was completed by a traveller in advance of their pre‐travel health consultation. Logistic regression identified variables independently associated with compliance.

Results  Influenza vaccination uptake for the 5 years preceding the study was found to be 20·8%. This was statistically significantly higher for older travellers and those with underlying health conditions (P < 0·005). Mean intention to comply with antiviral drugs on a preventive and therapeutic basis was 58% and 72%, respectively, and this varied markedly with age and with dispensed antimalarial chemoprophylaxis.

Conclusion  This study identifies some beliefs and perceptions travellers consider with regard to the therapeutic and preventive influenza use of antivirals during the H1N1 pandemic; it underscores the importance of travellers receiving hemisphere appropriate influenza vaccination. The external validity of these study findings requires further corroboration involving other travel clinics and different cohorts of travellers during seasonal activity or outbreaks of influenza. These findings could guide the development of future strategies for the prevention of influenza in travellers.
Dating and substance use in adolescent peer networks: a replication and extension
Authors: Kreager Derek A. , Haynie Dana L. , Hopfer Suellen
Published: September 2012

Aims

The current report examined associations between romantic partner, peer and individual substance use behaviors in a sample of American adolescents.

Design

The report used two waves of data (8th and 9th grades) from the Partnerships to Enhance Resilience (PROSPER) intervention project and focused on dating couples and their friends in 54 sampled school‐cohorts. Hierarchical logistic regression models examined the associations between friend, partner and friend‐of‐partner substance use and daters' future drinking and smoking.

Setting

Surveys administered in rural Pennsylvania and Iowa secondary schools.

Participants

A total of 744 dating couples.

Measurements

Student participants completed questionnaires that assessed substance use, background characteristics and dating and friend nominations. Friend, partner and friend‐of‐partner substance use were assessed at each wave directly from respective reports.

Findings

Consistent with a bridging hypothesis, friends‐of‐partner drinking had a strong and independent association with subsequent drunkenness (b = 1.40, P < 0.01) and drinking (b = 0.82, P < 0.01) among daters, and these associations did not vary by gender. A similar association was not observed for smoking, where partner (b = 0.77, P < 0.01) and direct friends (b = 1.19, P < 0.05) smoking showed strong and significant associations with future smoking, but friends‐of‐partner smoking did not (b = −0.44, P > 0.10).

Conclusion

Romantic partner and peer behaviors have substantially different associations with adolescent drinking and smoking. Intervention efforts aimed at reducing teenage smoking should be aimed at proximal peer and romantic relationships, whereas interventions of teenage drinking should also include the wider circle of indirect friends.
The impact of quality of work life on job embeddedness and affective commitment and their co‐effect on turnover intention of nurses
Authors: Zhao XiaoWen , Sun Tao , Cao QiuRu , Li Ce , Duan XiaoJian , Fan LiHua , Liu Yan
Published: September 2012

Aims and objectives.  To verify with empirical evidence the hypothesised relation and the effect of quality of work life, job embeddedness and affective commitment on turnover intention of clinical nurses in China.

Background.  High turnover of the nursing workforce in healthcare organisations is a difficult and recurring problem in China as well as in many other countries in the world. It leads to great waste of resources and increases management cost. Developing and retaining the nursing workforce, which is a major challenge faced by human resources practitioners in hospitals and public health agencies, also becomes a subject of interest for management studies. Most of the literature about voluntary turnover focused on such traditional measures as job satisfaction and job alternatives in the past. The introduction of such new concepts as quality of work life, job embeddedness and affective commitment, which views the issue from a much broader and comprehensive spectrum, made a great breakthrough in the turnover study. In this study, we selected quality of work life, job embeddedness and affective commitment – three of the most important factors in employer–employee relations – and analysed the interaction between each one of them, as well as their co‐effect on turnover intention of Chinese nurses.

Methods.  Cross‐sectional survey and structural equation modelling were applied in studying the self‐report questionnaires distributed to 1000 nurses employed in five large‐scale government‐owned hospitals in Heilongjiang Province, Northeast China.

Findings.  Our study confirmed the hypothesised positive relation of quality of work life with job embeddedness and affective commitment and the hypothesised negative relation of quality of work life with turnover intention, that is, high quality of work life perceived by the nurses enhances their job embeddedness and affective commitment and thus reduces their intention to leave the job.

Conclusions.  The effect of quality of work life is positive on job embeddedness and affection commitment and negative on turnover intention.

Relevance to clinical practice.  Nurse managers should pay great attention to the nurses' perception of quality of work life, and make great efforts in developing strategies and projects that can strengthen the nurses' embeddedness or connection with the job.
Introducing the bio‐psycho‐social‐physical model of dementia through a collective case study design
Authors: Keady John , Jones Lesley , Ward Richard , Koch Susan , Swarbrick Caroline , Hellström Ingrid , Davies‐Quarrell Vivienne , Williams Sion
Published: September 2012

Aims and objectives

To provide evidence for the development of a physical domain attached to the well‐known bio‐psycho‐social model of dementia. The objectives were to develop a set of international case studies that followed a trajectory approach, from prevention to end‐of‐life care.

Background

In the UK the bio‐psycho‐social model has informed the shape of the National Institute for Health and Clinical Excellence and the Social Care Institute for Excellence ‘dementia’ guideline. However, limited attention has been paid to outlining and describing a physical domain of dementia, a discrepancy that informed the rationale for this study.

Design

A collective case study design was used to address the research aim and objectives.

Methods

Case studies from along the trajectory of dementia were provided by an international team of contributors from an inter‐disciplinary background comprising nursing (general and mental health), social work and social science.

Results

The team's synthesis and analysis of the six case studies generated five repeating themes with each theme becoming components of a ‘physical’ domain of dementia. The five identified physical components were: (1) physical well‐being, (2) physical health and examination, (3) physical care, (4) physical treatment and (5) physical environment.

Conclusions

The development of a bio‐psycho‐social‐physical model of dementia presents a holistic and culturally sensitive approach to understanding the experience of living with dementia, and to providing care and support in a variety of situations and contexts.

Relevance to clinical practice

The physical domain of dementia has particular relevance to nursing and nursing practice, such as providing physical care at the end‐of‐life. The interplay between the biological‐psychological‐social‐physical domains of dementia and the trajectory of dementia could form the basis of clinical decision‐making and practice.
Fractional anisotropy distributions in 2‐ to 6‐year‐old children with autism
Authors: Cascio C. , Gribbin M. , Gouttard S. , Smith R. G. , Jomier M. , Field S. , Graves M. , Hazlett H. C. , Muller K. , Gerig G. , Piven J.
Published: September 2012

Background  Increasing evidence suggests that autism is a disorder of distributed neural networks that may exhibit abnormal developmental trajectories. Characterisation of white matter early in the developmental course of the disorder is critical to understanding these aberrant trajectories.

Methods  A cross‐sectional study of 2‐ to 6‐year‐old children with autism was conducted using diffusion tensor imaging combined with a novel statistical approach employing fractional anisotropy distributions. Fifty‐eight children aged 18–79 months were imaged: 33 were diagnosed with autism, 8 with general developmental delay, and 17 were typically developing. Fractional anisotropy values within global white matter, cortical lobes and the cerebellum were measured and transformed to random F distributions for each subject. Each distribution of values for a region was summarised by estimating δ, the estimated mean and standard deviation of the approximating F for each distribution.

Results  The estimated δ parameter, , was significantly decreased in individuals with autism compared to the combined control group. This was true in all cortical lobes, as well as in the cerebellum, but differences were most robust in the temporal lobe. Predicted developmental trajectories of across the age range in the sample showed patterns that partially distinguished the groups. Exploratory analyses suggested that the variability, rather than the central tendency, component of was the driving force behind these results.

Conclusions  While preliminary, our results suggest white matter in young children with autism may be abnormally homogeneous, which may reflect poorly organised or differentiated pathways, particularly in the temporal lobe, which is important for social and emotional cognition.