bluuebunny/crossref_metadata_2025 huggingface dataset:
UK Stock Returns and the Impact of Domestic Monetary Policy Shocks
Authors: Bredin Don , Hyde Stuart , Nitzsche Dirk , O'reilly Gerard
Published: February 2007

Abstract:  We investigate the influence of changes in UK monetary policy on UK stock returns and the possible reasons behind such a response. Firstly, we conduct an event study to assess the impact of unexpected changes in monetary policy on aggregate and sectoral stock returns. The decomposition of unexpected changes in the policy rate is based on futures markets data. Secondly, using a variance decomposition in the spirit of Campbell (1991) we attempt to identity the channels behind the response of stock returns to monetary policy surprises. The variance decomposition results indicate that the monetary policy shock leads to a persistent negative response in terms of future excess returns for a number of sectors.
Validation of sternal skin conductance for detection of hot flashes in prostate cancer survivors
Authors: Hanisch Laura J. , Palmer Steven C. , Donahue Aletheia , Coyne James C.
Published: February 2007

The gold standard for objectively measuring hot flashes in women is an increased sternal skin conductance level (SCL), but validation studies in prostate cancer patients are lacking. In the laboratory, an SCL increase of ≥1.78 micro‐mho in 45 s had a sensitivity of 68% and a positive predictive value of 100% in detecting self‐reported hot flashes among prostate cancer patients. Outside the laboratory, 71% of the objective markers of hot flashes were accompanied by a subjective report of a hot flash, and 65% of subjective reports occurred in the absence of an objective criterion. This study demonstrates that sternal skin conductance can be used to detect hot flashes in men in a manner analogous to its utilization among women. Such use would improve outcome analysis of treatment studies.
Target‐to‐target interval, intensity, and P300 from an auditory single‐stimulus task
Authors: Gonsalvez Craig J. , Barry Robert J. , Rushby Jacqueline A. , Polich John
Published: February 2007

Target‐to‐target interval (TTI) is a primary determinant of P300 amplitude, such that longer TTIs yield larger components than shorter intervals. Systematic manipulations of TTI affect component amplitude, latency, and associated response time in a fashion that suggests that the template update hypothesis can account for these outcomes. The present study examines whether manipulations of TTI (from 1 to 16 s) and stimulus intensity (soft and loud tones) produce outcomes consistent with this hypothesis. A single‐stimulus task was employed in which only target stimuli were presented. P300 amplitude increased, peak latency decreased, and response time increased as TTI became longer, with less effect for soft compared to loud stimulus conditions on P300 amplitude at Pz. TTI increases also augmented N100 amplitude, with consistently smaller amplitudes obtained for soft relative to loud stimuli. Overall, P300 measures are sensitive to both temporal and physical stimulus factors. Theoretical implications are discussed.
Brain electrical correlates of dimensional weighting: An ERP study
Authors: Gramann Klaus , Toellner Thomas , Krummenacher Joseph , Eimer Martin , Müller Hermann J.
Published: February 2007

In visual search, there is a reaction time (RT) cost for targets on a given trial if the previous target was defined in a different dimension. According to the “dimension‐weighting” account (Müller, Heller, & Ziegler, 1995), limited attentional weight needs to be shifted to the new dimension, resulting in slower RTs. The present study aimed at identifying brain electrical correlates associated with the weight shift. Analyses of ERPs revealed several components to reflect dimension changes whether the task was to detect the target or to identify its defining dimension. N2 amplitudes were more negative whenever the dimension changed. The P3 exhibited latency differences that mirrored RTs in both tasks, but the amplitudes showed no direct relation to stimulus‐ or response‐related processes. Finally, slow‐wave amplitudes were enhanced for dimension changes. Taken together, the results provide support for relatively early, perceptual processes underlying dimension change costs.
‘From saris to sarongs’ ethnicity and intergenerational influences on consumption among Asian Indians in the UK
Authors: Sekhon Yasmin K.
Published: February 2007

This paper investigates the role of ethnicity and intergenerational influences on the consumption patterns of Asian Indians living in the UK The research determines the extent to which (a) ethnicity and (b) intergenerational factors influence consumption and decision making. The empirical evidence suggests that ethnicity, background and cultural roots impact on consumer decision making and brand choice. The study aims to develop the research on the role and strength of intergenerational influences in an Asian Indian context; bringing together acculturation, generational and consumption theory.
A comparison of marketing practices: perspectives from first and second generation UK South Asians
Authors: McPherson Mark
Published: February 2007

This paper highlights not only the differences and similarities in marketing activities between first and second generation South Asian entrepreneurs; but the extent to which such activities lead to convergence with the mainstream small business population also. Therefore, differences are found in the fact that first generation respondents consider organic growth, thus differentiation via expansion initiatives and related diversification, as a way to access new co‐ethnic and non‐ethnic customer markets. This contrasts with that of the second generation. Here these particular respondents prefer to adopt a more transparent and open approach to marketing via knowledge skills advantage, and technological expertise.

A feature common to both sets of respondents, and again one which this paper argues may be indicative of any small business, finds respondents following some form of self‐directed informal customer care/customer centric philosophies. Interestingly, there is no evidence to support differences in customer care and practice between the various business sectors or generation, given that such practices appear even in the absence of any formal procedures and written policies also.
Lack of agreement between thermodilution and echocardiographic determination of cardiac output during normovolemia and acute hemorrhage in clinically healthy, anesthetized dogs
Authors: Day Thomas K. , Boyle Carolyn R. , Holland Merrilee
Published: February 2007

Objective and hypothesis:To determine whether or not there is agreement between the thermodilution and echocardiographic measurement of cardiac output (CO) during normovolemia and acute hemorrhage. The hypothesis was that there will be agreement between echocardiographic measurement of CO (ECO) and thermodilution measurement of CO (TDCO) during normovolemia and acute hemorrhage.

Design:CO was measured by both thermodilution and echocardiography during α‐chloralose anesthesia in dogs before and 15 and 30 minutes following acute arterial hemorrhage.

Setting:Laboratory investigation.

Animals:Eighteen clinically healthy dogs, weighing 20–25 kg, anesthetized with α‐chloralose.

Interventions:Acute arterial hemorrhage of approximately 50% of the total blood volume. CO was measured by thermodilution and echocardiography before and 15 and 30 minutes following hemorrhage.

Measurements and main results:Acute hemorrhage resulted in a significant decrease in CO. There was a lack of agreement between the 2 methods to measure CO at each time and at all anatomic points of measurement in the aorta and pulmonary artery.

Conclusion:There is a lack of agreement between the 2 methods; thus, determination of CO by echocardiography may not be a clinically useful tool following hemorrhage in dogs.
Progression to cirrhosis in hepatitis C patients: an age‐dependent process
Authors: Pradat Pierre , Voirin Nicolas , Tillmann Hans Ludger , Chevallier Michèle , Trépo Christian
Published: February 2007

Background: Age at infection is known to be associated with disease progression rate in hepatitis C virus (HCV) infected patients. The aim of this study was to assess when cirrhosis is expected to occur according to host and viral factors.

Methods: Fibrosis progression was studied in 247 naive HCV patients using multiple regression analysis. The expected age at cirrhosis was calculated for each patient.

Results: Progression rate was 0.13, 0.14, 0.27, and 0.36 U of fibrosis/year for patients with age at infection ≤19, 20–24, 25–36 and ≥37 years, respectively. Age at infection above 37 years was independently associated with fast progression (rate>0.13; P=0.001). Body mass index >25 kg/m2 and alanine aminotransferase>3 × ULN are also possibly associated with faster progression. Based on progression rates, the expected age at cirrhosis is 65.4, 64.6, 64.8 and 69.4 years for age at infection ≤19, 20–24, 25–36, ≥37 years, respectively.

Conclusion: Most HCV patients, if untreated, are expected to develop cirrhosis at about 65 years, irrespective of the age at infection. Thus, age itself seems even more important than age at infection for predicting the occurrence of liver cirrhosis. A specific active monitoring and therapeutic approach should be adopted in older patients to prevent progression to cirrhosis and its complications.
Severe hepatitis C virus‐related cryoglobulinaemic sensory–motor polyneuropathy treated with pegylated interferon‐a2b and ribavirin: clinical, laboratory and neurophysiological study
Authors: Koskinas J. , Kilidireas C. , Karandreas N. , Kountouras D. , Savvas S. , Hadziyannis E. , Archimandritis A.J.
Published: February 2007

Background/Aims: Severe involvement of central and/or peripheral nervous system is a rare complication of hepatitis C virus (HCV)‐related cryoglobulinaemia.

Method: Four patients with HCV‐related type II/III cryoglobulinaemia (three males with genotype 1, one female with genotype 3) who presented with severe sensory–motor polyneuropathy, one with central nervous system involvement as well, were treated with pegylated IFNa‐2b 1.5 μg/kg/week and ribavirin 10.6 mg/kg/daily for 48 weeks. Neurological evaluation involved detailed clinical motor and sensory scores/scales and neurophysiological studies before and after treatment.

Results/Conclusion: Three out of four patients had undetectable serum HCV‐RNA, normal levels of aminotransferases and substantially lower or undetectable levels of cryoglobulins at the end of treatment and at 24 weeks follow‐up period. Treatment was well tolerated and all patients exhibited significant improvement of neuropathy based on solid clinical and laboratory criteria that was associated with the virological response.
Treatment and retreatment in patients with chronic hepatitis C: 10 years clinical practice in a single centre
Authors: Economou Michael S. , Filis Spyridon , Vienna Helen , Christodoulou Dimitrios , Christou Leonidas , Tsianos Epameinondas V.
Published: February 2007

Aim:Therapy for chronic hepatitis C (HCV) has mainly been evaluated in large clinical, select population, trials. We sought to evaluate whether prognostic factors of therapeutic response are similar in clinical practice, where treated population is more diverse.

Methods:Retrospective study of HCV‐infected patients who completed >6 months of treatment/retreatment with various therapeutic regimens, in a single reference centre over a 10‐year period. Adjuvant treatment with hemopoetic growth factors was used when warranted by treatment side effects.

Results:Overall, 77/125 patients (61.6%) achieved sustained virological response (SVR). Fifty‐four naïve patients (43.2%) achieved SVR; 19 (26%) with interferon‐α (IFN‐α), 13 (59.1%) with IFN‐α and ribavirin, and 22 (73.3%) with pegylated IFN‐α and ribavirin. Seventeen patients responded after two courses of therapy and six after more than three courses, achieving a total SVR of 32%. Patients with genotype‐1 were less probable to achieve SVR [odds ratio (OR)=6.23], while younger patients were more possible to achieve SVR, OR=0.97. Most non‐responders after >2 regimens were genotype‐1 patients (90%).

Conclusions:In clinical practice, where strict selection criteria cannot be applied, genotype‐1 remains the most significant prognostic factor of response failure. Addition of adjuvant hemopoetic growth factors, when warranted, may increase compliance and thus overall SVR.
Tacrolimus for the treatment of primary sclerosing cholangitis
Authors: Talwalkar Jayant A. , Gossard Andrea A. , Keach Jill C. , Jorgensen Roberta A. , Petz Janice L. , Lindor R. N. Keith D.
Published: February 2007

Background: Results from a pilot investigation with tacrolimus for primary sclerosing cholangitis (PSC) demonstrated biochemical improvement without excessive drug toxicity. To date, no confirmatory study has been performed.

Aims: We sought to determine the safety and efficacy of tacrolimus in PSC.

Methods: An open‐label, phase II study of tacrolimus 0.05 mg/kg twice daily for 1 year was performed. Target whole‐blood concentrations ranged between 3 and 7 ng/ml.

Results: A total of 16 patients were enrolled. The median age was 50 years (range, 28–68), with 31% being women. The median serum alkaline phosphatase was 903 U/l, AST 88 U/l, total bilirubin 0.9 mg/dl, and albumin 3.8 g/dl. Based primarily on drug‐related adverse events, only eight (50%) patients completed 1 year of therapy. After 1 year of therapy, however, significant improvements in median serum alkaline phosphatase (903 vs. 483, P=0.0001) and AST levels (88 vs. 78, P=0.002) were observed in these patients. The median tacrolimus level in patients completing 1 year of therapy was 4.0 ng/ml. Drug‐related adverse events, however, were responsible for 31% of participants withdrawing from the study.

Conclusions: Despite significant improvements in serum alkaline phosphatase, oral tacrolimus is poorly tolerated in patients with PSC.
In Vitro Bursting Pressures of Jejunal Enterotomy Closures in Llamas
Authors: SEMEVOLOS STACY A. , REED SHANNON K. , GAMBLE KARI
Published: February 2007

Objective— To evaluate closure strength (in vitro bursting pressure) of jejunal enterotomies in llamas.

Study Design— In vitro experimental study.

Sample Population— Jejunal specimens (n=72) from 6 llamas.

Methods— Differences in bursting pressures and luminal diameters were compared between 2 layer enterotomy closures with an initial full thickness simple continuous pattern oversewn with either a continuous Lembert or Cushing suture pattern using 3 sizes (2‐0, 3‐0, 4‐0) of polyglactin 910 and polydioxanone.

Results— Bursting pressures were significantly higher for enterotomies closed with polydioxanone than polyglactin 910, independent of suture size, but there was no difference between Lembert and Cushing oversew patterns. Use of a Lembert pattern reduced intestinal diameter more than a Cushing pattern regardless of suture material or size.

Conclusions— Although polydioxanone resisted higher bursting pressures than polyglactin 910, both suture materials should be considered satisfactory for jejunal enterotomy closure in llamas based on typical intraluminal pressures expected in clinical patients. The optimal oversew pattern may be continuous Cushing to maximize the luminal diameter in small intestinal enterotomy closures.

Clinical Relevance— In vitro bursting pressures may help to predict which enterotomy sites would leak post‐operatively, although further studies are necessary to determine the outcome in clinical patients.
Diabetes mellitus promotes periodontal destruction in children
Authors: Lalla Evanthia , Cheng Bin , Lal Shantanu , Kaplan Selma , Softness Barney , Greenberg Ellen , Goland Robin S. , Lamster Ira B.
Published: February 2007

Aim: The association between diabetes mellitus and periodontal attachment and bone loss is well established. Most of the prior literature has focused on adults, and studies in children have mostly reported gingival changes. Our aim was to assess the periodontal status of a large cohort of children and adolescents with diabetes.

Material and Methods: We examined 350 children with diabetes (cases) and 350 non‐diabetic controls (6–18 years of age). Using three different case definitions for periodontal disease, which incorporated gingival bleeding and/or attachment loss findings, multiple logistic regression analyses adjusting for age, gender, ethnicity, frequency of prior dental visits, dental plaque, and examiner were performed.

Results: Subjects with diabetes had increased gingival inflammation and attachment loss compared with controls. Regression analyses revealed statistically significant differences in periodontal destruction between cases and controls across all disease definitions tested (odds ratios ranging from 1.84 to 3.72). The effect of diabetes on periodontal destruction remained significant when we separately analysed 6–11 and 12–18 year old subgroups.

Conclusions: These findings demonstrate an association between diabetes and an increased risk for periodontal destruction even very early in life, and suggest that programmes to address periodontal needs should be the standard of care for diabetic youth.
Prognosis after unmanipulated HLA‐haploidentical blood and marrow transplantation is correlated to the numbers of KIR ligands in recipients
Authors: Zhao Xiang‐yu , Huang Xiao‐jun , Liu Kai‐yan , Xu Lan‐ping , Liu Dai‐hong
Published: February 2007

Objectives:  The goal of this study was to explore the role of NK cell alloreaction in predicting prognosis under unmanipulated HLA‐haploidentical blood and marrow transplantation and examine whether the presence of any individual donor‐activating KIR gene had an influence on the clinical outcome.

Methods:  We studied the HLA and KIR genotype of 64 donor‐recipient pairs, who underwent transplantation.

Results:  In contrast to Perugia's KIR ligand–ligand mismatch model or Handgretinger's KIR receptor–ligand mismatch model or Bignon's KIR gene–gene mismatch model between donor‐recipient pairs, we found that the cumulative incidence of 3‐yr disease‐free survival (DFS), overall survival (OS), and transplantation‐related mortality (TRM) were best predicted by the number of KIR ligands carried by patients (HR 0.355, 95% CI 0.186–0.678, P = 0.002 for DFS; HR 0.445, 95% CI 0.233–0.848, P = 0.014 for OS; HR 0.450, 95% CI 0.219–0.926, P = 0.030 for TRM). Moreover, an analysis of KIR ligand numbers was found to be correlative in patients with lymphoid malignancy. The KIR ligand–ligand mismatch model is a good predictor of acute graft vs. host disease (aGVHD; HR 3.812, 95% CI 1.667–8.720, P = 0.002). Meanwhile, the presence of donor‐activating KIR2DS3 also contributed significantly to acute (HR 2.967, 95% CI 1.265–6.958, P = 0.012) and chronic GVHD (HR 2.541, 95% CI 1.127–5.730, P = 0.025).

Conclusions:  These data indicate that prognosis after transplantation is associated with the numbers of KIR ligands in recipients and T‐cell alloreaction may play a predominant role in this model.
Profound neutropenia resulting from interaction between antiretroviral therapy and vinblastine in a patient with HIV‐associated Hodgkin's disease
Authors: Makinson Alain , Martelli Nicolas , Peyrière Hélène , Turriere Chrystell , Moing Vincent Le , Reynes Jacques
Published: February 2007

A HIV infected patient was treated for stage IVB Hodgkin's lymphoma by ABVD (doxorubicine, bleomycine, vinblastine, dacarbazine) chemotherapy and lopinavir–ritonavir based antiretroviral therapy inducing profound life‐threatening neutropenia. Vinblastine and lopinavir–ritonavir interaction was managed with lopinavir–ritonavir interruption around chemotherapy administration, with complete remission and immunovirological success after six cycles. This unrecorded strategy is discussed.
Candida albicans does not invade carious human dentine
Authors: Maijala M , Rautemaa R , Järvensivu A , Richardson M , Salo T , Tjäderhane L
Published: February 2007

Aim:  Candida albicans has been proposed to be a caries pathogen, but the evidence for its specific role is lacking. To be considered significant in caries progression, a marked amount of yeasts should be present in a lesion. The aim of the study was to investigate the presence of C. albicans in dentinal caries lesions.

Materials and methods:  To demonstrate the extension of caries and to identify the bacteria in a lesion, sections of 10 carious human teeth were stained with Gram and Giemsa stains. C. albicans was detected with periodic acid‐Schiff (PAS) staining and by immunohistochemistry using a C. albicans‐specific antibody 3H8. Thirty sections were used for each staining (in total 120 sections).

Results:  Extensive bacterial invasion and intensive staining by PAS occurred in all samples. However, with the C. albicans‐specific antibody, only 30 (3.3%) sections stained weakly positive, with a few stained cells on the lesion surface. However, the positive identification of C. albicans, based on the morphology of the cells, was not possible.

Conclusions:  The results do not support the previous suggestion that C. albicans is important in the dentine caries pathology. In addition, because of its unspecific nature, PAS turned out to be an unsuitable method for detecting yeasts in carious tooth samples.
Practice makes perfect? Evaluation of cricoid pressure task training for use within the algorithm for rapid sequence induction in critical care
Authors: May Peter , Trethewy Christopher
Published: February 2007

Objective:  To assess task training in cricoid pressure application suitable for incorporation into the algorithm for rapid sequence induction in acute care.

Method:  A blinded prospective direct observational study of 110 critical care staff of two hospitals in regional New South Wales. Each participant was instructed to apply blinded cricoid force within the target range of 30–40 N to a cricoid model mounted on a weighing scale and the result recorded. After up to 3 min of unblinded practice without coaching on the same model a repeat blinded application of force was recorded. The pre‐ and post‐intervention results were compared.

Results:  At the pre‐intervention stage, 22 participants (20%) applied initial pressure within the target range, increasing to 57 (52%) at the post‐intervention stage (χ2 = 24.19, d.f. = 1, P < 0.01; odds ratio [OR] = 0.23; 95% confidence interval [CI] 0.12–0.44). The post‐intervention results show a significant improvement in the number of participants achieving the target range in both nursing (χ2 = 20.42, d.f. = 1, P < 0.01; OR = 0.18; 95% CI 0.08–0.42) and medical subgroups (χ2 = 4.68, d.f. = 1, P = 0.03; OR = 0.34; 95% CI 0.11–1.02). The number applying force sufficient to prevent regurgitation, that is 30 N or greater, rose from 71 to 97 (65% to 88%) (χ2 = 17.02, d.f. = 1, P < 0.01; OR = 0.24; 95% CI 0.11–0.51). The number applying in excess of 44 N fell from 41 to 25 (37% to 21%) (χ2 = 5.54, d.f. = 1, P < 0.02; OR = 2.02; 95% CI 1.08–3.81).

Conclusion:  The application of cricoid force by critical care staff can be significantly improved by up to 3 min of practice on a simple task trainer.
Frova intubating catheter position can be determined with aspirating oesophageal detection device
Authors: Kadry Tahir , Harvey Martyn , Wallace Muir , Imrie Justin
Published: February 2007

Objective:  Intubating catheters (e.g. gum‐elastic bougie) are an invaluable adjunct in the management of a difficult airway. Traditional tactile ‘click’ (from tracheal rings) and ‘hold up’ (from carina or bronchus) techniques for confirming tracheal placement are, however, fallible, and definitive placement can only be confirmed following passage of the endotracheal tube. Ensuing delays might contribute to the development of arterial hypoxaemia. Our aim was to determine whether an aspirating oesophageal detector device might be useful for confirming placement of the Frova intubating catheter (a hollow‐bore intubating catheter).

Method:  Eighteen adult patients (American Society of Anaesthiology category 1–2) undergoing elective surgery had the Frova intubating catheter alternately placed in the trachea, or oesophagus, following induction of anaesthesia. Catheter position was assessed using an aspirating oesophageal detector device prior to tracheal intubation.

Results:  The oesophageal detector device correctly predicted tracheal (n = 18) and oesophageal (n = 18) placement in all patients. All procedures were completed in less than 15 s.

Conclusion:  In the operating theatre setting the aspirating oesophageal detector device reliably predicts tracheal and oesophageal placement of the Frova intubating catheter.
Emergency department personal protective equipment requirements following out‐of‐hospital chemical biological or radiological events in Australasia
Authors: Sansom Guy W
Published: February 2007

Recent events have led to a revision in ED equipment, preparedness and training for disasters. However, clinicians must still decide when, and what level of personal protection is required when a toxic threat exists. If possible, clear, simple and achievable protocols are required in such situations. Following an off‐site Australasian chemical biological or radiological incident, current evidence indicates that the initial receiving ED staff will be adequately protected from all known chemical biological and radiological inhalational threats by wearing a properly fitted P2 (N95) mask, or its equivalent. Protection from serious contact injury is offered by wearing double gloves, disposable fluid‐repellent coveralls or gown, eye protection, surgical mask, and ideally, a cap and shoe covers; in conjunction with universal precautions and procedures.
Effects of Season, Rainfall, and Hydrogeomorphic Setting on Mangrove Tree Growth in Micronesia
Authors: Krauss Ken W. , Keeland Bobby D. , Allen James A. , Ewel Katherine C. , Johnson Darren J.
Published: February 2007

Seasonal patterns of tree growth are often related to rainfall, temperature, and relative moisture regimes. We asked whether diameter growth of mangrove trees in Micronesia, where seasonal changes are minimal, is continuous throughout a year or conforms to an annual cycle. We installed dendrometer bands on Sonneratia alba and Bruguiera gymnorrhiza trees growing naturally within mangrove swamps on the islands of Kosrae, Federated States of Micronesia (FSM), Pohnpei, FSM, and Butaritari, Republic of Kiribati, in the eastern Caroline Islands of the western Pacific Ocean. Trees were remeasured monthly or quarterly for as long as 6 yr. Annual mean individual tree basal area increments ranged from 7.0 to 79.6 cm2/yr for all S. alba trees and from 4.8 to 27.4 cm2/yr for all B. gymnorrhiza trees from Micronesian high islands. Diameter increment for S. alba on Butaritari Atoll was lower at 7.8 cm2/yr for the one year measured. Growth rates differed significantly by hydrogeomorphic zone. Riverine and interior zones maintained up to seven times the annual diameter growth rate of fringe forests, though not on Pohnpei, where basal area increments for both S. alba and B. gymnorrhiza were approximately 1.5 times greater in the fringe zone than in the interior zone. Time‐series modeling indicated that there were no consistent and statistically significant annual diameter growth patterns. Although rainfall has some seasonality in some years on Kosrae and Pohnpei and overall growth of mangroves was sometimes related positively to quarterly rainfall depths, seasonal diameter growth patterns were not distinctive. A reduced chance of moisture‐related stress in high‐rainfall, wetland environments may serve to buffer growth of Micronesian mangroves from climatic extremes.
An Ant Mosaic Revisited: Dominant Ant Species Disassemble Arboreal Ant Communities but Co‐Occur Randomly
Authors: Sanders Nathan J. , Crutsinger Gregory M. , Dunn Robert R. , Majer Jonathan D. , Delabie Jacques H. C.
Published: February 2007

The spatial distributions of many tropical arboreal ant species are often arranged in a mosaic such that dominant species have mutually exclusive distributions among trees. These dominant species can also mediate the structure of the rest of the arboreal ant community. Little attention has been paid to how diet might shape the effects of dominant species on one another and the rest of the ant community. Here, we take advantage of new information on the diets of many tropical arboreal ant species to examine the intra‐ and inter‐guild effects of dominant species on the spatial distribution of one another and the rest of the tropical arboreal ant community in a cocoa farm in Bahia, Brazil. Using null model analyses, we found that all ant species, regardless of dominance status or guild membership, co‐occur much less than expected by chance. Surprisingly, the suite of five dominant species showed random co‐occurrence patterns, suggesting that interspecific competition did not shape their distribution among cocoa trees. Across all species, there was no evidence that competition shaped co‐occurrence patterns within guilds. Co‐occurrence patterns of subordinant species were random on trees with dominant species, but highly nonrandom on trees without dominant species, suggesting that dominant species disassemble tropical arboreal ant communities. Taken together, our results highlight the often complex nature of interactions that structure species‐rich tropical arboreal ant assemblages.
Low Inbreeding and High Pollen Dispersal Distances in Populations of Two Amazonian Forest Tree Species
Authors: Cloutier Dominic , Hardy Olivier J. , Caron Henri , Ciampi Ana Y. , Degen Bernd , Kanashiro Milton , Schoen Daniel J.
Published: February 2007

Recent studies suggest that tropical tree species exhibit low inbreeding and high gene dispersal levels despite the typically low density of conspecifics in tropical forests. To examine this, we undertook a study of pollen gene dispersal and mating system of two Amazonian tree species. We analyzed 341 seeds from 33 trees at four microsatellite loci in a Carapa guianensis population from Brazil, and 212 seeds from 22 trees at four microsatellite loci in a Sextonia rubra population from French Guiana. Differentiation of allele frequencies among the pollen pool of individual trees was ΦFT= 0.053 (95% CI: 0.027–0.074) for C. guianensis and ΦFT= 0.064 (95% CI: 0.017–0.088) for S. rubra. The mean pollen dispersal distances were estimated at 69–355 m for C. guianensis, and 86–303 m for S. rubra, depending on the pollen dispersal model and the estimate of reproductive tree density used. The multi‐locus outcrossing rate was estimated at 0.918 and 0.945, and the correlation of paternity at 0.089 and 0.096, for C. guianensis and S. rubra, respectively, while no significant levels of biparental inbreeding were detected. Comparing trees with high and low local density of conspecifics, we found no evidence for differences in inbreeding levels. The results are discussed within the framework of the emerging picture of the reproductive biology of tropical forest trees.
Phosphorus Fertilization Increases the Abundance and Nitrogenase Activity of the Cyanolichen Pseudocyphellaria crocata in Hawaiian Montane Forests
Authors: Benner Jon W. , Conroy Shannon , Lunch Claire K. , Toyoda Noriko , Vitousek Peter M.
Published: February 2007

Nitrogen‐fixing epiphytes (especially lichens with a cyanobacterial symbiont—cyanolichens) have the potential to contribute significant amounts of nitrogen (N) to montane tropical forests, which are typically low in N—but the factors controlling the abundance and distribution of epiphytic cyanolichens are poorly understood. In long‐term fertilization experiments in montane forests on a 4.l million‐yr‐old Oxisol on the island of Kauà'i and on a 152‐yr‐old lava flow on the island of Hawai'i, the epiphytic cyanolichen Pseudocyphellaria crocata increased significantly in abundance in canopies of host trees fertilized with phosphorus (P). There was no response to fertilization with N or other essential elements. Nitrogen‐fixation rates were also elevated in lichens in P‐fertilized plots at both sites. Phosphorus supply to host trees may be an important factor controlling N inputs to montane tropical forests by N‐fixing epiphytes.
Behavioral Avoidance of Ultraviolet‐B Radiation by Two Species of Neotropical Poison‐Dart Frogs
Authors: Han Barbara A. , Kats Lee B. , Pommerening Rachel C. , Ferrer Ryan P. , Murry‐Ewers Marcia , Blaustein Andrew R.
Published: February 2007

Many animals, plants, and microorganisms are harmed by ultraviolet‐B radiation. In particular, several members of class amphibia are negatively affected by exposure to ultraviolet‐B radiation. Exposure to ultraviolet‐B radiation can cause death or various types of sublethal damage in amphibians. One mechanism to lessen the effect of harmful ultraviolet‐B radiation is to limit exposure to sunlight behaviorally. Few studies have examined the behavioral sensitivity of adult amphibians to ultraviolet‐B radiation. Using both field experiments and field observations, we found that two species of diurnal poison‐dart frogs in Costa Rica (Dendrobates pumilio, D. auratus) consistently preferred areas in the field and within experimental testing chambers that offered low levels of ultraviolet‐B radiation. In field observations, vocalizing D. pumilio were found at locations with significantly lower levels of ambient ultraviolet‐B compared to random locations throughout their natural habitat. Ultraviolet‐B avoidance behavior may be an important behavioral response for tropical frogs in light of recent evidence suggesting a significant increase in the levels of ambient ultraviolet‐B radiation in the tropics over the past decade.
Indirect Evidence that Flying Foxes Track Food Resources Among Islands in a Pacific Archipelago
Authors: McConkey Kim R. , Drake Donald R.
Published: February 2007

Although flying foxes (fruit bats in the genus Pteropus) in continental forests often fly between scattered resources, little is known about their ranging behavior among islands. The inhospitable water matrix that surrounds the food patches (islands) in archipelagos may prevent flying foxes from tracking resources as efficiently as their counterparts on larger landmasses do. Our aim in this study was to determine whether the abundance of foraging flying foxes (Pteropus tonganus) reflected food availability on islands in the Vava‘u archipelago of Tonga, regardless of island size and isolation. Overall, food availability was the strongest determinant of flying fox abundance, and spatial aspects of the islands (land area within 10 km) had only a small influence. Food availability appears to regulate flying fox abundance only when food resources are low, but when food sources are plentiful, flying fox abundance may be high or low. These results provide indirect evidence that flying foxes are able to track food resources efficiently in an archipelago, and the water matrix that surrounds the food patches (islands) is not a strong deterrent for foraging animals.
Melbourne dietitians’ experience of Medicare policy on allied health services (strengthening Medicare; Enhanced Primary Care) in the first 12 months
Authors: CANT Robyn , ARONI Rosalie
Published: February 2007

Objective:  To describe Victorian private practitioner dietitians’ experience of the Enhanced Primary Care (EPC) program funded under national heath insurance.

Design:  Dietitians’ experience of the EPC program was investigated between August 2004 and July 2005. A purposive sample of 10% (n = 15) of Victorian dietitians in private practice was interviewed via semi‐structured interviews or focus groups. Focus group/interview data were audio‐taped, transcribed verbatim and thematically analysed using NVIVO software to manage data.

Subjects:  Victorian dietitians.

Setting:  Dietetic private practice.

Main outcome measures:  Issues identified from narrative themes.

Results:  Thirteen (86%) participants were registered with the Medicare Australia and managed EPC‐referred patients. Two chose not to. All those using the program supported it but voiced frustrations experienced in the first year. Five themes emerged from narrative analysis involving difficulties with implementation in the following areas: referral issues, client preparedness, annual number of consultations limit, impact of financial cost on client and non‐reimbursed administration costs.

Conclusion:  For clients with chronic illness, access to dietitians in private practice under Medicare EPC is an important service. As increasing numbers of dietitians nationally work with EPC patients with chronic illness or complex care needs, there is a need for information sharing between professional groups about billing procedures and chronic care management. More dietitians need to structure practice to initiate bulk‐billing. Rigorous evaluation is needed to understand which diagnosis types can benefit from the program and to implement an evidence‐based model of chronic care improvement for dietetics consultations.
Dietetic practice in type 2 diabetes: An ethnographic study of Australian dietitians
Authors: KNIGHTS Sallyanne , TAPSELL Linda
Published: February 2007

Objectives:  To explore and describe the work patterns of Australian dietitians working in type 2 diabetes and to identify variations in practice and gaps in applying evidence.

Subjects and design:  In‐depth telephone interviews were conducted with a purposive sample of 20 Australian dietitians working in the area of type 2 diabetes to determine elements of current practice and views on best practice. For the purpose of the present study a diabetes dietitian was defined as spending ≥50% of their patient management time in type 2 diabetes. Data were content‐analysed and ethnographic descriptions were developed for practitioners’ daily activities that were sensitive to the context in which the research was conducted.

Results:  Interviewees described a standard dietetic process, involving assessment, education, goal setting and the monitoring of outcomes. Their descriptions were consistent with practice guidelines established elsewhere and found in the literature; however, there was some variation in the management of elements within practice. These included dietary assessment, weight management, access to relevant assessment data such as test results and the description of dietary goals and outcome measures. Six components of best practice were identified: the dietetic process, client centredness, multidisciplinary teamwork, reference to evidence‐based practice guidelines, continuing professional development and practice‐based research and quality assurance activities.

Conclusion or application:  The present research demonstrated a consistency in practice in diabetes management by Australian dietitians. The ability of interviewees to determine the consequences of competent practice further suggests that the present research would support the development of practice guidelines.
Critical review of nutrition assessment tools to measure malnutrition in chronic kidney disease
Authors: CAMPBELL Katrina L. , ASH Susan , BAUER Judith , DAVIES Peter S.W.
Published: February 2007

The use of the Subjective Global Assessment (SGA) and similar clinical tools for nutrition assessment is integral in the nutritional management of chronic kidney disease (CKD) patients. The present paper is a critical review of the quality of studies introducing and validating SGA‐based tools in CKD. In the CKD literature, clinical, predictive and criterion validity were investigated by a number of studies. Common limitations identified include the use of questionable statistical methods, difference in prevalence of malnutrition based on tool or administrator (i.e. dietitan, nephrologist or nurse) and use of inadequate reference tests to establish true nutrition status. The SGA appears to have the best diagnostic evidence to adequately detect the presence of abnormal nutrition status and prognostic evidence to predict poor outcome. Modified scored versions may improve clinician’s ability to detect degree of malnutrition; however, the present review indicates more work is required. Tools based on the original SGA claiming validity in CKD and potentially other clinical areas should be approached with caution. Critical evaluation of study design, reference tests and statistical methods is recommended before implementing new tools in practice.
Dietitians and naturopaths require evidence‐based nutrition information on organic food
Authors: OJHA Rachel , AMANATIDIS Soumela , PETOCZ Peter , SAMMAN Samir
Published: February 2007

A pilot survey was undertaken to identify dietitians’ and naturopaths’ attitudes to and advice about organic foods, and to ascertain whether nutrition education is required. A questionnaire, which was not validated, was mailed to 240 randomly selected private practice dietitians and naturopaths in Australia. The responses were analysed by chi‐squared and independent two‐samples t‐test. Each group had a response rate of 50%. More dietitians (n = 52) than naturopaths (n = 18) (P < 0.01) indicated a lack of difference in protein (88% vs 30%), fat (83% vs 33% where n = 49 dietitians and 20 naturopaths) and carbohydrate (85% vs 38%, n = 50 dietitians and 23 naturopaths) between organic and conventional foods. Significantly more naturopaths (P < 0.01) than dietitians indicated that organic foods contained more vitamins (85% vs 32%, n = 51 naturopaths and 19 dietitians), minerals (82% vs 25%, n = 49 naturopaths and 15 dietitians) and phytochemicals (72% vs 32%, n = 43 naturopaths and 19 dietitians) compared with conventionally produced foods. The majority of naturopaths indicated that organic foods have a favourable effect on health (97%, n = 58) and differ in taste (82%, n = 49). Dietitians were less certain with n = 21 thinking there is an effect on health and n = 15 indicating that there is a difference in taste (P < 0.01). More naturopaths (77%, n = 46) than dietitians (31%, n = 18) indicated that they have sufficient knowledge of organic food. Naturopaths discuss the topic of organic food with their clients ‘sometimes’ (55%, n = 33) or ‘always’ (32%, n = 19) whereas the majority of dietitians ‘seldom’ (51%, n = 30) or ‘never’ (7%, n = 4) do so. Naturopaths recommend organic foods more often than dietitians (P < 0.001). The survey results suggest that evidence‐based educational programs would be useful for both groups of health professionals.
Microsatellite Instability in Pediatric and Adult High‐grade Gliomas
Authors: Eckert Anika , Kloor Matthias , Giersch Antje , Ahmadi Rezvan , Herold‐Mende Christel , Hampl Jürgen A. , Heppner Frank L. , Zoubaa Saida , Holinski‐Feder Elke , Pietsch Torsten , Wiestler Otmar D. , Von Knebel Doeberitz Magnus , Roth Wilfried , Gebert Johannes
Published: February 2007

About 15% of sporadic gastrointestinal and endometrial tumors show the microsatellite instability (MSI) phenotype because of loss of DNA mismatch repair (MMR) function. The incidence of MSI in tumors of the central nervous system still remains controversial. Previous studies reported a particular high frequency of MSI (∼25%) in young patients suffering from high‐grade gliomas. Based on these data and the fact that in different tumor entities MMR deficiency defines a subgroup of tumors with distinct pathogenesis and particular clinicopathological features that may have impact on prognosis and therapy, we screened 624 gliomas from 71 young and 553 adult patients for MMR deficiency by MSI analysis using three highly sensitive diagnostic markers. Alterations of MMR protein expression was examined by immunohistochemistry. A malignant glioma from an adult patient displayed MSI and concomitant loss of nuclear MSH2 and MSH6 protein expression (0.16%; 1/619). No evidence for MSI or loss of MMR protein expression was observed in 71 gliomas from young patients (0%; 0/71) including 41 high‐grade astrocytic tumors. Overall, we observed a much lower incidence of MSI among high‐grade pediatric gliomas than initially reported and suggest that MMR deficiency does not play a major role in the pathogenesis of glial neoplasms.
Apoptosis Initiated When BH3 Ligands Engage Multiple Bcl-2 Homologs, Not Bax or Bak
Authors: Willis Simon N. , Fletcher Jamie I. , Kaufmann Thomas , van Delft Mark F. , Chen Lin , Czabotar Peter E. , Ierino Helen , Lee Erinna F. , Fairlie W. Douglas , Bouillet Philippe , Strasser Andreas , Kluck Ruth M. , Adams Jerry M. , Huang David C. S.
Published: February 2007

A central issue in the regulation of apoptosis by the Bcl-2 family is whether its BH3-only members initiate apoptosis by directly binding to the essential cell-death mediators Bax and Bak, or whether they can act indirectly, by engaging their pro-survival Bcl-2–like relatives. Contrary to the direct-activation model, we show that Bax and Bak can mediate apoptosis without discernable association with the putative BH3-only activators (Bim, Bid, and Puma), even in cells with no Bim or Bid and reduced Puma. Our results indicate that BH3-only proteins induce apoptosis at least primarily by engaging the multiple pro-survival relatives guarding Bax and Bak.
CPD Damage Recognition by Transcribing RNA Polymerase II
Authors: Brueckner Florian , Hennecke Ulrich , Carell Thomas , Cramer Patrick
Published: February 2007

Cells use transcription-coupled repair (TCR) to efficiently eliminate DNA lesions such as ultraviolet light–induced cyclobutane pyrimidine dimers (CPDs). Here we present the structure-based mechanism for the first step in eukaryotic TCR, CPD-induced stalling of RNA polymerase (Pol) II. A CPD in the transcribed strand slowly passes a translocation barrier and enters the polymerase active site. The CPD 5′-thymine then directs uridine misincorporation into messenger RNA, which blocks translocation. Artificial replacement of the uridine by adenosine enables CPD bypass; thus, Pol II stalling requires CPD-directed misincorporation. In the stalled complex, the lesion is inaccessible, and the polymerase conformation is unchanged. This is consistent with nonallosteric recruitment of repair factors and excision of a lesion-containing DNA fragment in the presence of Pol II.
A Common Explosion Mechanism for Type Ia Supernovae
Authors: Mazzali Paolo A. , Röpke Friedrich K. , Benetti Stefano , Hillebrandt Wolfgang
Published: February 2007

Type Ia supernovae, the thermonuclear explosions of white dwarf stars composed of carbon and oxygen, were instrumental as distance indicators in establishing the acceleration of the universe's expansion. However, the physics of the explosion are debated. Here we report a systematic spectral analysis of a large sample of well-observed type Ia supernovae. Mapping the velocity distribution of the main products of nuclear burning, we constrain theoretical scenarios. We find that all supernovae have low-velocity cores of stable iron-group elements. Outside this core, nickel-56 dominates the supernova ejecta. The outer extent of the iron-group material depends on the amount of nickel-56 and coincides with the inner extent of silicon, the principal product of incomplete burning. The outer extent of the bulk of silicon is similar in all supernovae, having an expansion velocity of ∼11,000 kilometers per second and corresponding to a mass of slightly over one solar mass. This indicates that all the supernovae considered here burned similar masses and suggests that their progenitors had the same mass. Synthetic light-curve parameters and three-dimensional explosion simulations support this interpretation. A single explosion scenario, possibly a delayed detonation, may thus explain most type Ia supernovae.