bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacokinetic‐pharmacodynamic evaluation of ceftazidime continuous infusion vs intermittent bolus injection in septicaemic melioidosis
Authors: Angus B. J. , Smith M. D. , Suputtamongkol Y. , Mattie H. , Walsh A. L. , Wuthiekanun V. , Chaowagul W. , White N. J. 
Published: August 2009

Aims  Experimental studies have suggested that constant intravenous infusion would be preferable to conventional intermittent bolus administration of beta‐lactam antibiotics for serious Gram‐negative infections. Severe melioidosis (Burkholderia pseudomallei infection) carries a mortality over 40% despite treatment with high dose ceftazidime. The aim of this study was to measure the pharmacokinetic and pharmacodynamic effects of continuous infusion of ceftazidime vs intermittent bolus dosing in septicaemic melioidosis.Methods  Patients with suspected septicaemic melioidosis were randomised to receive ceftazidime 40 mg kg−1 8 hourly by bolus injection or 4 mg kg−1 h−1 by constant infusion following a 12 mg kg−1 priming dose and pharmacokinetic and pharmacodynamic parameters were compared.Results  Of the 34 patients studied 16 (59%) died. Twenty patients had cultures positive for B. pseudomallei of whom 12 (60%) died. The median MIC90 of B. pseudomallei was 2 mg l−1, giving a minimum target concentration (4*MIC) of 8 mg l−1. The median (range) estimated total apparent volume of distribution, systemic clearance and terminal elimination half‐lives of ceftazidime were 0.468 (0.241–0.573) l kg−1, 0.058 (0.005–0.159) l kg−1 h−1 and 7.74 (1.95–44.71) h, respectively. Clearance of ceftazidime and creatinine clearance were correlated closely (r = 0.71; P < 0.001) and there was no evidence of significant nonrenal clearance.Conclusions  Simulations based on these data and the ceftazidime sensitivity of the B. pseudomallei isolates indicated that administration by constant infusion would allow significant dose reduction and cost saving. With conventional 8 h intermittent dosing to patients with normal renal function, plasma ceftazidime concentrations could fall below the target concentration but this would be unlikely with a constant infusion. Correction for renal failure, which is common in patients with meliodosis is Clearance =k* creatinine clearance where k = 0.72. Calculation of a loading dose gives median (range) values of loading dose, DL of 18.7 mg kg−1 (9.5–23) and infusion rate I = 3.5 mg kg−1 h−1 (0.4–13) (which equals 84 mg kg−1 day−1). A nomogram for adjustment in renal failure is given.
Mechanisms and clinical implications of glucocorticosteroids in the treatment of allergic rhinitis
Authors: Okano M 
Published: August 2009

SummaryAllergic rhinitis is a common airway disease characterized by hypersensitivity, exudation, hypersecretion, inflammatory cell infiltration and remodelling. Intranasal glucocorticosteroids are the most effective drugs for controlling the inflammation caused by allergic rhinitis. Glucocorticosteroids exert anti-inflammatory effects through at least two pathways: the transactivation pathway and the transrepression pathway. Glucocorticosteroids also exert regulatory functions by inducing regulatory cytokines and forkhead box P3 (FoxP3+) regulatory T cells. Evidence suggests that intranasal glucocorticosteroids control not only nasal symptoms but also ocular symptoms. In contrast to sedating H1 receptor antagonists, intranasal glucocorticosteroids can improve impaired performance symptoms, such as daytime sleepiness, associated with allergic rhinitis. Recent studies suggest that intranasal glucocorticosteroids might also be useful for the prophylactic treatment of pollinosis; this possibility is supported by the molecular mechanism of the anti-inflammatory action of glucocorticosteroids. These findings suggest that intranasal glucocorticosteroids might be positioned as first-line drugs for the treatment of both perennial and seasonal allergic rhinitis.
Energetic costs of male reproduction in a scramble competition mating system
Authors: Lane Jeffrey E. , Boutin Stan , Speakman John R. , Humphries Murray M. 
Published: August 2009

Summary1. The assumption that the primary limitations on reproductive success differ between the sexes is inherent in traditional sexual selection theory. Although the energy that can be allocated to reproduction is assumed to be the main limitation to females, the ability to attract and defend oestrous females is assumed to be the primary limitation to males.2. Estimates of the energetic costs of reproduction in male mammals are, however, limited and have largely been obtained from sexually dimorphic species exhibiting female defence mating systems. These studies often reveal that the energetic cost of male reproduction is similar to or even exceeds that of females, and therefore challenge long‐held assumptions of inter‐sexual reproductive limitations, but their generality is little known.3. We coupled measurements of energy expenditure with detailed behavioural observations of reproductive male North American red squirrels (Tamiasciurus hudsonicus). This species displays minimal sexual dimorphism and exhibits a scramble competition mating system, under which sexual selection favours enhanced mate searching effort by males.4. We conducted the study over 2 years characterized by a substantial variation in upcoming natural food availability and across two study populations that experienced either natural food abundance or anad libitumfood‐supplementation to investigate the influence of resource availability on male reproductive energy expenditure.5. Under natural conditions, mean energy expenditure of males across the 2 years was high, approximating that of females during lactation. Furthermore, in the anticipation of high upcoming natural food availability and resultant offspring survival, expenditure approximately doubled (from 290 ± 7 to 579 ± 73 kJ day−1). When current food availability (and consequently the density of receptive females) was experimentally elevated, males displayed the highest levels of energy expenditure we recorded (873 ± 98 kJ day−1).6. Our results provide compelling evidence that the energy available for reproductive allocation places a strong limitation on reproduction in male North American red squirrels and contribute to previous work suggesting that high and limiting energetic costs of male reproduction may be a general feature of mammalian reproduction.
Stochastic demography and population dynamics in the red kangaroo Macropus rufus
Authors: Jonzén Niclas , Pople Tony , Knape Jonas , Sköld Martin 
Published: August 2009

Summary 1. Many organisms inhabit strongly fluctuating environments but their demography and population dynamics are often analysed using deterministic models and elasticity analysis, where elasticity is defined as the proportional change in population growth rate caused by a proportional change in a vital rate. Deterministic analyses may not necessarily be informative because large variation in a vital rate with a small deterministic elasticity may affect the population growth rate more than a small change in a less variable vital rate having high deterministic elasticity. 2. We analyse a stochastic environment model of the red kangaroo (Macropus rufus), a species inhabiting an environment characterized by unpredictable and highly variable rainfall, and calculate the elasticity of the stochastic growth rate with respect to the mean and variability in vital rates. 3. Juvenile survival is the most variable vital rate but a proportional change in the mean adult survival rate has a much stronger effect on the stochastic growth rate. 4. Even if changes in average rainfall have a larger impact on population growth rate, increased variability in rainfall may still be important also in long‐lived species. The elasticity with respect to the standard deviation of rainfall is comparable to the mean elasticities of all vital rates but the survival in age class 3 because increased variation in rainfall affects both the mean and variability of vital rates. 5. Red kangaroos are harvested and, under the current rainfall pattern, an annual harvest fraction of c. 20% would yield a stochastic growth rate about unity. However, if average rainfall drops by more than c. 10%, any level of harvesting may be unsustainable, emphasizing the need for integrating climate change predictions in population management and increase our understanding of how environmental stochasticity translates into population growth rate.
Leaf life span as a simple predictor of evergreen forest zonation in China
Authors: Zhang Lin , Luo Tianxiang , Zhu Huazhong , Daly Christopher , Deng Kunmei 
Published: August 2009

AbstractAim  Our aim was to investigate how the average life span of canopy leaves might be used to predict the geographical distribution of natural forests at large geographical scales, and to explore the link between leaf characteristics and ecosystem functioning. We examine whether there is a general relationship between canopy mean leaf life span and climate (i.e. temperature and precipitation) that can be used to predict evergreen forest zonation in China.Location  Forest areas in China.Methods  During July and August of 2002–2004, we conducted a latitudinal forest transect spanning about 30° of latitude in eastern China. The canopy mean leaf life span was calculated to include all tree species (groups) in each forest plot through weighted averages scaled up from branch‐level measurements. Data from our previous work conducted in the Tibetan Alpine Vegetation Transects (TAVT) and from other investigators were compiled to supplement our results. Based on regression equations developed on the pooled data, and using gridded temperature and precipitation datasets, we simulated the distribution of canopy mean leaf life span for forests in China. The predicted leaf life span zonation was compared with a map of Chinese forest vegetation divisions published in 1980.Results  Canopy mean leaf life span across 10 evergreen forest plots in eastern China showed a decreasing trend as mean annual temperature increased, following a common logistic pattern consistent with the data from the TAVT and other investigators. In pooled data for 40 evergreen forest plots across tropical and boreal regions, canopy mean leaf life span generally showed a negative relationship with mean annual temperature (r2 = 0.72, P < 0.001), and a positive correlation with mean annual precipitation where mean annual temperature was > 8°C (r2 = 0.45, P < 0.01). The climate‐based simulations of leaf life span zonation compared well with the previously published boundaries of forest vegetation divisions in eastern China.Main conclusions  Our results reveal that mean leaf life span in evergreen forests follows a common logistic pattern associated with mean annual temperature and precipitation, which can in turn be used to predict evergreen forest zonation in eastern China.
Spatially autocorrelated sampling falsely inflates measures of accuracy for presence‐only niche models
Authors: Veloz Samuel D. 
Published: August 2009

AbstractAim  Environmental niche models that utilize presence‐only data have been increasingly employed to model species distributions and test ecological and evolutionary predictions. The ideal method for evaluating the accuracy of a niche model is to train a model with one dataset and then test model predictions against an independent dataset. However, a truly independent dataset is often not available, and instead random subsets of the total data are used for ‘training’ and ‘testing’ purposes. The goal of this study was to determine how spatially autocorrelated sampling affects measures of niche model accuracy when using subsets of a larger dataset for accuracy evaluation.Location  The distribution of Centaurea maculosa (spotted knapweed; Asteraceae) was modelled in six states in the western United States: California, Oregon, Washington, Idaho, Wyoming and Montana.Methods  Two types of niche modelling algorithms – the genetic algorithm for rule‐set prediction (GARP) and maximum entropy modelling (as implemented with Maxent) – were used to model the potential distribution of C. maculosa across the region. The effect of spatially autocorrelated sampling was examined by applying a spatial filter to the presence‐only data (to reduce autocorrelation) and then comparing predictions made using the spatial filter with those using a random subset of the data, equal in sample size to the filtered data.Results  The accuracy of predictions from both algorithms was sensitive to the spatial autocorrelation of sampling effort in the occurrence data. Spatial filtering led to lower values of the area under the receiver operating characteristic curve plot but higher similarity statistic (I) values when compared with predictions from models built with random subsets of the total data, meaning that spatial autocorrelation of sampling effort between training and test data led to inflated measures of accuracy.Main conclusions  The findings indicate that care should be taken when interpreting the results from presence‐only niche models when training and test data have been randomly partitioned but occurrence data were non‐randomly sampled (in a spatially autocorrelated manner). The higher accuracies obtained without the spatial filter are a result of spatial autocorrelation of sampling effort between training and test data inflating measures of prediction accuracy. If independently surveyed data for testing predictions are unavailable, then it may be necessary to explicitly account for the spatial autocorrelation of sampling effort between randomly partitioned training and test subsets when evaluating niche model predictions.
Interspecific pairwise relationships among body size, clutch size and latitude: deconstructing a macroecological triangle in birds
Authors: Boyer Alison G. , Cartron Jean‐Luc E. , Brown James H. 
Published: August 2009

AbstractAim Ecogeographical ‘rules’, large‐scale patterns in ecological variables across geographical space, can provide important insights into the mechanisms of evolution and ecological assembly. However, interactions between rules could obscure both the observation of large‐scale patterns and their interpretation. Here, we examine a system of three variables interrelated by ecogeographical rules – the latitudinal increase in body size within closely related homeotherms (Bergmann’s rule), the negative allometry of clutch size (Calder’s rule) and the latitudinal increase in clutch size (Lack’s rule) – in a global dataset of birds.Location Global.Methods We used linear regressions and meta‐analysis techniques to quantify the three rules across clades and through the taxonomic hierarchy. Path analysis was used to quantify interactions between rules at multiple taxonomic levels, as a function of both phylogenetic inheritance of traits and indirect feedbacks between the three rules. Independent contrasts analyses were performed on four clades with available phylogenies, and the taxonomic partitioning of variation in each trait was quantified.Results Standardizing across all clades, Lack’s and Bergmann’s rules were supported at all taxonomic levels, with Calder’s rule being supported at the order level. Lack’s rule was consistently stronger and more often detected than the other two rules. Path analysis showed that the indirect effects often outweighed the direct effects of Calder’s rule at the genus level and Bergmann’s rule at the order level. Strong interactions between Calder’s and Bergmann’s rules led to a trade‐off between the rules depending on taxonomic resolution.Main conclusions We found strong interactions between Bergmann’s, Lack’s and Calder’s rules in birds, and these interactions varied in strength and direction over the taxonomic hierarchy and among avian clades. Ecogeographical rules may be masked by feedbacks from other, correlated variables, even when the underlying selective mechanism is operating. The apparently conflicting pairwise relationships among clutch size, body size and latitude illustrate the difficulty of interpreting individual pairwise correlations without recognition of interdependence with other variables.
Establishment success of invasive ring‐necked and monk parakeets in Europe
Authors: Strubbe Diederik , Matthysen Erik 
Published: August 2009

AbstractAim  Invasive alien species are a growing threat to biodiversity, and identifying the mechanisms that enable these species to establish viable populations in their new environment is paramount for management of the problems they pose. Using an unusually large number of both failed and successful documented introductions of parakeets (Aves: Psittacidae) in Europe, we test two of the major hypotheses on the establishment success of invading species, namely the climate‐matching and the human‐activity hypothesis.Location  European human population centres where ring‐necked parakeet (Psittacula krameri) and/or monk parakeet (Myiopsitta monachus) introductions have occurred.Methods  Data on ring‐necked and monk parakeet introductions in Europe were gathered from various sources, including published books and articles, but also from unpublished reports and local grey literature. Information was verified with experts from the region under consideration. In order to test the climate‐matching hypothesis, we verified whether the climatic factors that determine the parakeets’ native ranges also explain establishment success in Europe. Parakeet occurrence data from the native ranges were analysed using the presence‐only modelling method Maxent, and correlations between parakeet establishment and climatic and anthropogenic variables in Europe were assessed using both stepwise logistic regression and the information‐theoretic model selection approach.Results  The establishment success of ring‐necked and monk parakeets was found to be positively associated with human population density, and, both in the native and in the introduced regions, parakeet occurrence was negatively correlated with the number of frost days. Thus, parakeets are more likely to establish in warmer and human‐dominated areas.Main conclusions  The large number of independent parakeet introductions in Europe allows us to test the often‐used climate‐matching and human‐activity hypotheses at the species level. We show that both hypotheses offer insight into the invasion process of monk and ring‐necked parakeets. Our results suggest that, in the future, parakeet establishment probability may increase even further because global warming is likely to cause a decrease in the number of frost days and because urbanization and human populations are still increasing.
THIS ARTICLE HAS BEEN RETRACTED A psychometric evaluation of the Chinese version of the Hospital Anxiety and Depression Scale in patients with coronary heart disease
Authors: Wang Wenru , Chair Sek Ying , Thompson David R , Twinn Sheila F 
Published: August 2009

Aim.  To evaluate further the psychometric properties of the Chinese version of the Hospital Anxiety and Depression Scale (HADS) as a screening instrument for anxiety and depression in Chinese patients with coronary heart disease in Xian, China.Background.  There is considerable evidence that anxiety and depression are common in patients with coronary heart disease (CHD) and are associated with increased morbidity and mortality. A valid, reliable and sensitive screening tool that can be used readily on this group of patients would be useful for assessment, intervention and outcome evaluation.Design.  A single group, cross‐sectional study.Method.  Measurement performance was tested on 314 Chinese patients with coronary heart disease and repeated on 173 of them two weeks later.Results.  The Chinese version of HADS (C‐HADS) had acceptable internal consistency and test‐retest reliability, with a Cronbach alpha of 0·85 and intraclass correlation coefficient of 0·90, respectively. There was acceptable concurrent validity with significant (p < 0·05) correlations between the anxiety and depression subscales of the C‐HADS and CHD patients’ perceived health status as measured by the Chinese Mandarin version of the Short Form‐36 health survey (CM:SF‐36). Principal components analysis revealed a three‐factor solution accounting for 53% of the total variance. The three underlying sub‐scale dimensions are depression, psychic anxiety and psychomotor anxiety. The responsiveness of the C‐HADS was also satisfactory with significant correlation between the changes in the C‐HADS score and the changes in the Mental Health domain of the CM:SF‐36 (p < 0·01). Finally, over one‐third of the patients demonstrated psychological distress.Conclusion.  Empirical data support the C‐HADS as a reliable and valid screening instrument for the assessment of anxiety and depression in Chinese‐speaking patients with CHD. A tri‐dimensional scoring approach should be considered as potentially clinically useful for this group of patients.Relevance to clinical practice.  The C‐HADS can guide and evaluate the delivery of psychological care for Chinese patients with CHD.
Evaluation of a nursing intervention project to promote patient medication education
Authors: Nurit Porat , Bella Bar Cohen , Gila Elkokan , Revital Zelker 
Published: August 2009

Aim and objective.  The purpose of this study was to evaluate patients’ knowledge regarding their medication regime following a nursing interventional project in patient medication education.Design.  Evaluation.Background.  Educating patients during their hospital stay regarding their medical treatment is an issue which the medical staff deals with on a daily basis. The hospitalisation period is a known critical point in the provision of influential information to the patient and related family members, probably because the hospitalised patient and family members have unique learning needs that cannot be postponed.Methods.  The study was conducted in three internal medicine wards in a large university tertiary hospital in Jerusalem, Israel. The intervention project used structured written materials and verbal patient education related to highly potent drugs. The study evaluated patients’ knowledge regarding their medication as the main interventional outcome. In addition, the rate of patients receiving verbal and written education, rate of patient intention to take the medication and adequacy of nursing interventions according to the patients’ educational needs were also assessed. Data collection was carried out by a short structured tool that examined patient knowledge. With this tool, the nurse interviewed the patients and recorded the patient’s response and her recommended intervention.Results.  Two hundred and fifty‐one patients participated in the study. Most of the patients (71–93%) reported that they had received instructions from nurses. The majority of the patients demonstrated a high level of knowledge regarding their medications and planned on taking their medications on a regular basis. Lack of knowledge was observed mostly on issues related to dietary recommendations. In these cases, the nurses’ intervention was not always documented and did not necessarily match the problem identified.Conclusions.  The findings show that patients, who received medication education, demonstrated satisfactory level of knowledge and intended to take their medication. Patients’ knowledge feedback enables the nurse to assess her intervention.Relevance to clinical practice.  Patient medication education in the hospital is a challenging task. This article suggests an applicable tool to assure that patients receive appropriate medication education, while assessing the effectiveness of this education. This tool also enables the nurses to modify their intervention according to patient response.