bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships between the Antarctic Oscillation, the Madden–Julian Oscillation, and ENSO, and Consequences for Rainfall Analysis
Authors: Pohl B. , Fauchereau N. , Reason C. J. C. , Rouault M.
Published: August 2009

The Antarctic Oscillation (AAO) is the leading mode of atmospheric variability in the Southern Hemisphere mid- and high latitudes (south of 20°S). In this paper, the authors examine its statistical relationships with the major tropical climate signals at the intraseasonal and interannual time scales and their consequences on its potential influence on rainfall variability at regional scales. At the intraseasonal time scale, although the AAO shows its most energetic fluctuations in the 30–60-day range, it is not unambiguously related to the global-scale Madden–Julian oscillation (MJO) activity, with in particular no coherent phase relationship with the MJO index. Moreover, in the high southern latitudes, the MJO-associated anomaly fields do not appear to project coherently on the well-known AAO patterns and are never of an annular nature. At the interannual time scale, a strong teleconnection with ENSO is found during the peak of the austral summer season, corroborating previous studies. El Niño (La Niña) tends to correspond to a negative (positive) AAO phase. The results are statistically significant only when the seasonal mean fields averaged for the November through February season are considered.

Based on these results, the authors then isolate the specific influence of the AAO on rainfall variability at both intraseasonal and interannual time scales. The example taken here is southern Africa, a region under the influence of both the MJO and ENSO, experiencing its main rainy season in austral summer and containing a relatively dense network of rain gauge measurements. At the interannual time scale, the significance of the teleconnections between southern African rainfall and the AAO reveals itself to be a statistical artifact and becomes very weak once the influence of ENSO is removed. At the intraseasonal time scale, the AAO is seen to significantly affect the rainfall amounts over much of the country, without interference with other modes of variability. Its influence in modulating the rain appears to be strongest during La Niña years.
The Seasonal Atmospheric Response to Projected Arctic Sea Ice Loss in the Late Twenty-First Century
Authors: Deser Clara , Tomas Robert , Alexander Michael , Lawrence David
Published: August 2009

The authors investigate the atmospheric response to projected Arctic sea ice loss at the end of the twenty-first century using an atmospheric general circulation model (GCM) coupled to a land surface model. The response was obtained from two 60-yr integrations: one with a repeating seasonal cycle of specified sea ice conditions for the late twentieth century (1980–99) and one with that of sea ice conditions for the late twenty-first century (2080–99). In both integrations, a repeating seasonal cycle of SSTs for 1980–99 was prescribed to isolate the impact of projected future sea ice loss. Note that greenhouse gas concentrations remained fixed at 1980–99 levels in both sets of experiments. The twentieth- and twenty-first-century sea ice (and SST) conditions were obtained from ensemble mean integrations of a coupled GCM under historical forcing and Special Report on Emissions Scenarios (SRES) A1B scenario forcing, respectively.

The loss of Arctic sea ice is greatest in summer and fall, yet the response of the net surface energy budget over the Arctic Ocean is largest in winter. Air temperature and precipitation responses also maximize in winter, both over the Arctic Ocean and over the adjacent high-latitude continents. Snow depths increase over Siberia and northern Canada because of the enhanced winter precipitation. Atmospheric warming over the high-latitude continents is mainly confined to the boundary layer (below ∼850 hPa) and to regions with a strong low-level temperature inversion. Enhanced warm air advection by submonthly transient motions is the primary mechanism for the terrestrial warming. A significant large-scale atmospheric circulation response is found during winter, with a baroclinic (equivalent barotropic) vertical structure over the Arctic in November–December (January–March). This response resembles the negative phase of the North Atlantic Oscillation in February only. Comparison with the fully coupled model reveals that Arctic sea ice loss accounts for most of the seasonal, spatial, and vertical structure of the high-latitude warming response to greenhouse gas forcing at the end of the twenty-first century.
Modeled Climate State and Dynamic Responses to Anomalous North American Snow Cover
Authors: Sobolowski Stefan , Gong Gavin , Ting Mingfang
Published: August 2009

The radiative and thermal properties of widespread snow cover anomalies have the potential to modulate local and remote climate over monthly to seasonal time scales. In this study, physical and dynamical links between anomalous North American snow conditions and Northern Hemisphere climate are examined. A pair of 40-member ensemble AGCM experiments is run, with prescribed high- and low-snow forcings over North America during the course of an entire year (EY). The difference between the two ensemble averages reflects the climatic response to sustained EY snow forcing. Local surface responses over the snow forcing occur in all seasons, and a significant remote surface temperature response occurs over Eurasia during spring. A hemispheric-scale transient eddy response to EY forcing also occurs, which propagates downstream from the forcing region to Eurasia, and then reaches a maximum in extent and amplitude in spring. The evolution of this transient eddy response is indicative of considerable downstream development and is consistent with known storm-track dynamics. This transient response is shown to be a result of persistent steepened temperature gradients created by the anomalous snow conditions, which contribute to enhanced baroclinicity over the storm-track entrance regions. A second pair of experiments is run, with the prescribed high- and low-snow forcings over North America restricted to the fall season (FS). The dynamical response to FS forcing is muted compared to the EY scenario, suggesting that the seasonal timing and persistence of the snow forcing are essential for the remote teleconnection.
Effectiveness and Safety of Medication Adjustments by Nurse Case Managers to Control Hyperglycemia
Authors: Curtis Jeffrey , Lipke Suzanne , Effland Shirley , Dickinson Bridget , McCabe Alberta , Russell Bernadine , Russell Marie , Bloomquist Paul , Wilson Charlton
Published: August 2009

Purpose

The purpose of this study was to determine the safety and effectiveness of implementing standing orders for nurse case managers to adjust antihyperglycemic medications.

Methods

A retrospective cohort design was used to assess outcomes in American Indian and Alaska Native people who received case management and medication adjustment and those who received only standard primary care. Patients with diabetes and evidence of keeping regular follow-up appointments for diabetes care (N = 2345) who all had baseline A1C ≥ 7.0% were divided into 3 mutually exclusive groups for analysis: (1) those seen only by primary care providers (PCP; n = 1574); (2) those seen by nurse case managers (NCM; in addition to primary care) for diabetes education services only (n = 711); and (3) those who, in addition to a PCP and NCM visit, had medications adjusted by the nurse case managers (MA; n = 60). Outcome variables were number of visits with documentation of hypoglycemia (safety) and rate of A1C change (effectiveness).

Results

Documented hypoglycemia occurred more frequently with more intensive treatment. The MA group experienced the greatest rate of hypoglycemic events. The difference in hypoglycemia incidence between the groups was significant, but the number of events was small. Glycemic control improved most rapidly in the MA group, even after adjusting for potentially confounding variables.

Conclusions

In this setting, hypoglycemia occurs infrequently in all groups, but at higher rates with more intensive treatment. Nurse case management, whether with or without medication adjustment, is effective in improving short-term glucose control.
Filtering to Match Hearing Aid Insertion Gain to Individual Ear Acoustics
Authors: Bell Steven L.
Published: August 2009

When hearing aid gain is prescribed by software, gain is calculated based on the average acoustics for the age of patient, gender, mold type, and so on. The acoustics of the individual's ear often vary from the average values, so there will be a mismatch between the prescribed gain and the real-ear gain. Real-ear measurement can be used to verify the gain and adjust it to meet targets, but the quality of the match will be limited by the number of channels and the flexibility of the hearing aid. A potential way to improve this process is to generate a filter that compensates for variations in real-ear insertion gain due to individual ear acoustics. Such a filter could be included in the processing path of a digital hearing aid. This article describes how such a filter can be generated using the windowing method, and the principle is demonstrated in a real ear. The approach requires communication between the real-ear measurement and hearing aid programming software. A finite impulse response filter with group delay just over 2 ms matched insertion gain to target values within the acceptable tolerance defined by British Society of Audiology guidelines.
High-mix analogue insulins: do they have a therapeutic role?
Authors: Grant Paul , Dashora Umesh
Published: August 2009

It is estimated that 39% of diabetic patients worldwide that use insulin therapy are prescribed premixed insulin formulations, largely because of the practical advantages of addressing both prandial and basal insulin needs with a single product. High-mix insulin analogues are a relatively little used therapy and this paper explores their role in the management of diabetes. There is a paucity of research on their clinical efficacy and safety with regards to hypoglycaemia and we conclude that in certain patients they can be helpful for difficult-to-control postprandial hyperglycaemia, but there are no long-term outcome studies to assess whether this has an impact on cardiovascular outcomes and the current gold standard of insulin therapy still remains a basal bolus regimen.

Br J Diabetes Vasc Dis 2009;9:166—170
Manifestation of lower extremity atherosclerosis in patients with high ankle-brachial index
Authors: Hong Zhang  , Li Xiao-Ying , Yajun Si  , Xilie Lu  , Liping Chen  , Zhaoyang Liu
Published: August 2009

The purpose of this study was to identify the manifestation of lower extremity atherosclerotic lesions in patients with high ankle-brachial index (ABI). We studied 92 diabetic patients at random from the Endocrine Department of the Chinese PLA General Hospital. According to the ABI value, the subjects were divided into three groups: high, normal and low ABI groups. On the basis of the results of lower extremity artery duplex ultrasound, the patients in the high ABI group had a lower incidence of low extremity artery occlusion than those in the low ABI group, and the atherosclerotic lesions of patients in the high group mainly displayed diffuse dot-like hyperechogenicity spots or small plaques (60.9%), and their atherosclerotic lesions in the lower extremity were mostly found in the distal segment (44.4%). This atherosclerosis in the lower extremities of patients in the high ABI group was shown to be consistent with the pathological features of artery intimal and medial calcification. It suggests that a high ABI is highly predictive of artery calcification, which is a marker of poor cardiovascular prognosis in diabetes.

Br J Diabetes Vasc Dis 2009;9:160—164
Evaluation of the clinical performance of a chlorhexidine gluconate antimicrobial transparent dressing
Authors: Moureau Nancy L. , Deschneau Mary , Pyrek Janine
Published: August 2009

Each year, an estimated 250,000 cases of central

line associated bloodstream infections occur in hospitals in the United States (CDC, 2005). Reduction of CRBSI has become a major focus for education and initiatives to improve practice. Various antimicrobial agents and practices are supported with evidence to demonstrate impact on CRBSI. The broad spectrum activity of chlorhexidine as an antibacterial, antiviral, and antifungal agent is well accepted (Denton, 2001).

The purpose of this clinical evaluation was to statistically validate the performance of a new chlorhexidine gluconate (CHG) gel dressing. A fully integrated transparent dressing with a CHG gel pad was evaluated in six different facilities across the United States over a period of 73 days with 64 different clinicians. A total of 500 CHG gel dressings were applied during the evaluation period. The clinicians were asked to evaluate 16 levels of performance criteria of the new CHG gel dressings and compare these areas of performance to the performance of their current CHG disk plus transparent dressing being used at their facility. Their current dressing was replaced with the new CHG gel dressing. All sites changed dressings at 24—48 hours as needed, and then at seven days. The evaluation questions were striated into four performance groups: ease of application, gel dressing performance, securement function and ‘other’. In all 16 levels of performance ratings, the CHG gel dressing was rated ‘same as’, ‘better’, or ‘much better’. In addition to the antimicrobial advantages of a CHG gel dressing, clinical data demonstrates the following benefits: ease of use of a one piece CHG gel dressing, ability to fully visualise the insertion site through the gel, and absorption of fluid under the dressing. The new CHG gel dressing was well tolerated by patients and performed in a manner that equalled or well exceeded the current two step process of antimicrobial dressing application.
Loss of the Rho GTPase activating protein p190-B enhances hematopoietic stem cell engraftment potential
Authors: Xu Haiming , Eleswarapu Satyam , Geiger Hartmut , Szczur Kathleen , Daria Deidre , Zheng Yi , Settleman Jeffrey , Srour Edward F. , Williams David A. , Filippi Marie-Dominique
Published: August 2009

Hematopoietic stem cell (HSC) engraftment is a multistep process involving HSC homing to bone marrow, self-renewal, proliferation, and differentiation to mature blood cells. Here, we show that loss of p190-B RhoGTPase activating protein, a negative regulator of Rho GTPases, results in enhanced long-term engraftment during serial transplantation. This effect is associated with maintenance of functional HSC-enriched cells. Furthermore, loss of p190-B led to marked improvement of HSC in vivo repopulation capacity during ex vivo culture without altering proliferation and multilineage differentiation of HSC and progeny. Transcriptional analysis revealed that p190-B deficiency represses the up-regulation of p16Ink4a in HSCs in primary and secondary transplantation recipients, providing a possible mechanism of p190-B–mediated HSC functions. Our study defines p190-B as a critical transducer element of HSC self-renewal activity and long-term engraftment, thus suggesting that p190-B is a target for HSC-based therapies requiring maintenance of engraftment phenotype.
GRP-78 secreted by tumor cells blocks the antiangiogenic activity of bortezomib
Authors: Kern Johann , Untergasser Gerold , Zenzmaier Christoph , Sarg Bettina , Gastl Guenther , Gunsilius Eberhard , Steurer Michael
Published: August 2009

Antiangiogenic effects of the proteasome inhibitor bortezomib were analyzed on tumor xenografts in vivo. Bortezomib strongly inhibited angiogenesis and vascularization in the chicken chorioallantoic membrane. Bortezomib's inhibitory effects on chorioallantoic membrane vascularization were abrogated in the presence of distinct tumor xenografts, thanks to a soluble factor secreted by tumor cells. Through size-exclusion and ion-exchange chromatography as well as mass spectroscopy, we identified GRP-78, a chaperone protein of the unfolded protein response, as being responsible for bortezomib resistance. Indeed, a variety of bortezomib-resistant solid tumor cell lines (PC-3, HRT-18), but not myeloma cell lines (U266, OPM-2), were able to secrete high amounts of GRP-78. Recombinant GRP-78 conferred bortezomib resistance to endothelial cells and OPM-2 myeloma cells. Knockdown of GRP78 gene expression in tumor cells and immunodepletion of GRP-78 protein from tumor cell supernatants restored bortezomib sensitivity. GRP-78 did not bind or complex bortezomib but induced prosurvival signals by phosphorylation of extracellular signal–related kinase and inhibited p53-mediated expression of proapoptotic Bok and Noxa proteins in endothelial cells. From our data, we conclude that distinct solid tumor cells are able to secrete GRP-78 into the tumor microenvironment, thus demonstrating a hitherto unknown mechanism of resistance to bortezomib.
The human alloreactive CD4+ T-cell repertoire is biased to a Th17 response and the frequency is inversely related to the number of HLA class II mismatches
Authors: Litjens Nicolle H. R. , van de Wetering Jacqueline , van Besouw Nicole M. , Betjes Michiel G. H.
Published: August 2009

Estimates of precursor frequency and assessment of functional characteristics of alloreactive CD4+ T cells are all biased by the need for long-term culture. In this study, direct visualization of human alloreactive CD4+ T cells on the single-cell level was achieved using cell surface expression of CD154 as a tool for identification. The average frequency of alloreactive CD154+CD4+ T cells among peripheral blood CD4+ T cells was 0.1%, with half of the cells displaying a naive phenotype. The proliferation capacity and expression of cytokines after allogeneic stimulation resided in these CD154+CD4+ T cells. The repertoire of alloreactive CD4+ T cells was biased to a Th17 response, and on average 24% of alloreactive CD154+CD4+ memory T cells produced interleukin-17 (IL-17) after polyclonal stimulation. Unexpectedly, mixed cell cultures from human leukocyte antigen (HLA)–identical donors also generated alloreactive CD154+CD4+ T cells and yielded the highest frequency compared with HLA-nonidentical combinations. Therefore, reactivity to minor histocompatibility antigens between HLA-identical subjects appears to be relatively common. Alloreactive HLA-identical T cells did not proliferate or express cytokines, but were driven to proliferation in the presence of exogenous IL-2.
Prognostically relevant breakdown of 123 patients with systemic mastocytosis associated with other myeloid malignancies
Authors: Pardanani Animesh , Lim Ken-Hong , Lasho Terra L. , Finke Christy , McClure Rebecca F. , Li Chin-Yang , Tefferi Ayalew
Published: August 2009

The prognostic heterogeneity of the World Health Organization category of “systemic mastocytosis with associated clonal hematologic nonmast cell lineage disease” (SM-AHNMD) has not been systematically validated by primary data. Among 138 consecutive cases with SM-AHNMD, 123 (89%) had associated myeloid neoplasm: 55 (45%) myeloproliferative neoplasm (SM-MPN), 36 (29%) chronic myelomonocytic leukemia, 28 (23%) myelodysplastic syndrome (SM-MDS), and 4 (3%) acute leukemia. Of the myeloid subgroups, SM-MPN displayed a 2- to 3-fold better life expectancy (P = .003), whereas leukemic transformation was more frequent in SM-MDS (29%; P = .02). The presence of eosinophilia, although prevalent (34%), was prognostically neutral, and the overall results were not affected by exclusion of FIP1L1-PDGFRA-positive cases. We conclude that it is clinically more useful to consider specific entities, such as SM-MPN, systemic mastocytosis with chronic myelomonocytic leukemia, SM-MDS, and systemic mastocytosis with-acute leukemia, rather than their broad reference as SM-AHNMD.
Plasmodium falciparum–infected erythrocytes induce NF-κB regulated inflammatory pathways in human cerebral endothelium
Authors: Tripathi Abhai K. , Sha Wei , Shulaev Vladimir , Stins Monique F. , Sullivan David J.
Published: August 2009

Cerebral malaria is a severe multifactorial condition associated with the interaction of high numbers of infected erythrocytes to human brain endothelium without invasion into the brain. The result is coma and seizures with death in more than 20% of cases. Because the brain endothelium is at the interface of these processes, we investigated the global gene responses of human brain endothelium after the interaction with Plasmodium falciparum–infected erythrocytes with either high- or low-binding phenotypes. The most significantly up-regulated transcripts were found in gene ontology groups comprising the immune response, apoptosis and antiapoptosis, inflammatory response, cell-cell signaling, and signal transduction and nuclear factor κB (NF-κB) activation cascade. The proinflammatory NF-κB pathway was central to the regulation of the P falciparum–modulated endothelium transcriptome. The proinflammatory molecules, for example, CCL20, CXCL1, CXCL2, IL-6, and IL-8, were increased more than 100-fold, suggesting an important role of blood-brain barrier (BBB) endothelium in the innate defense during P falciparum–infected erythrocyte (Pf-IRBC) sequestration. However, some of these diffusible molecules could have reversible effects on brain tissue and thus on neurologic function. The inflammatory pathways were validated by direct measurement of proteins in brain endothelial supernatants. This study delineates the strong inflammatory component of human brain endothelium contributing to cerebral malaria.
Immunogenicity of blood group antigens: a mathematical model corrected for antibody evanescence with exclusion of naturally occurring and pregnancy-related antibodies
Authors: Tormey Christopher A. , Stack Gary
Published: August 2009

Blood group antigen immunogenicity is a crucial factor in red blood cell alloimmunization. Previous calculated estimates of immunogenicity suffered from several key shortcomings. To address these issues we have (1) introduced a correction factor for antibody persistence rates into traditional immunogenicity calculations, (2) calculated immunogenicities only in men to eliminate pregnancy-related antibodies, and (3) excluded antibodies reactive only at room temperature to minimize the contribution of naturally occurring antibodies. With these corrections, we have calculated the immunogenicities of common blood group antigens using data collected on clinically significant alloantibodies (n = 452) in a male patient population. We observed a 3- to 5-fold increase in immunogenicity for some antigens (ie, Jka, Cw, Lua) and smaller changes in others compared with traditionally calculated estimates. In addition, we have calculated the transfusion-related immunogenicities of antigens traditionally associated with naturally occurring antibodies (eg, anti-Lea, -Leb, -M, and -P1).
Karyotype-specific microRNA signature in chronic lymphocytic leukemia
Authors: Visone Rosa , Rassenti Laura Z. , Veronese Angelo , Taccioli Cristian , Costinean Stefan , Aguda Baltazar D. , Volinia Stefano , Ferracin Manuela , Palatini Jeff , Balatti Veronica , Alder Hansjuerg , Negrini Massimo , Kipps Thomas J. , Croce Carlo M.
Published: August 2009

Chromosomal abnormalities, immunoglobulin heavy chain variable–region (IGHV) gene mutation status, and ζ-associated protein 70 (ZAP-70) expression levels have independent prognostic relevance in chronic lymphocytic leukemia (CLL); however, their concordance is variable. Because deregulation of microRNAs has been linked to disease initiation and progression in CLL, we studied the value of the microRNAs as a signature for CLL patients with specific chromosomal abnormalities. We identified 32 microRNAs able to discriminate the 11q deletion, 17p deletion, trisomy 12, 13q deletion, and normal karyotype cytogenetic subgroups. The expression values of 9 among the 32 microRNAs (miR-151-3p, miR-34a, miR-29c, miR-29b, miR-155, miR-148a, miR-146a, miR-146b5p, and miR-640) were correlated with gene expression data from the same samples to assess their biologic impact on CLL. In this study we also found that IGHV unmutated, high expression of ZAP-70 protein, and low expression of the miR-223, miR-29c, miR-29b, and miR-181 family were strongly associated with disease progression in CLL cases harboring 17p deletion, whereas in those harboring trisomy 12 only high expression of the miR-181a, among the analyzed parameters, suggested more aggressive disease. Thus, the use of the microRNA-based classifications may yield clinically useful biomarkers of tumor behavior in CLL.
Renal impairment in a rural African antiretroviral programme
Authors: Franey Cara , Knott Deborah , Barnighausen Till , Dedicoat Martin , Adam Ahmed , Lessells Richard J , Newell Marie-Louise , Cooke Graham S
Published: August 2009

Background

There is little knowledge regarding the prevalence and nature of renal impairment in African populations initiating antiretroviral treatment, nor evidence to inform the most cost effective methods of screening for renal impairment. With the increasing availability of the potentially nephrotixic drug, tenofovir, such information is important for the planning of antiretroviral programmes

Methods

(i) Retrospective review of the prevalence and risk factors for impaired renal function in 2189 individuals initiating antiretroviral treatment in a rural African setting between 2004 and 2007 (ii) A prospective study of 149 consecutive patients initiating antiretrovirals to assess the utility of urine analysis for the detection of impaired renal function. Severe renal and moderately impaired renal function were defined as an estimated GFR of ≤ 30 mls/min/1.73 m2 and 30–60 mls/min/1.73 m2 respectively. Logistic regression was used to determine odds ratio (OR) of significantly impaired renal function (combining severe and moderate impairment). Co-variates for analysis were age, sex and CD4 count at initiation.

Results

(i) There was a low prevalence of severe renal impairment (29/2189, 1.3% 95% C.I. 0.8–1.8) whereas moderate renal impairment was more frequent (287/2189, 13.1% 95% C.I. 11.6–14.5) with many patients having advanced immunosuppression at treatment initiation (median CD4 120 cells/μl). In multivariable logistic regression age over 40 (aOR 4.65, 95% C.I. 3.54–6.1), male gender (aOR 1.89, 95% C.I. 1.39–2.56) and CD4<100 cells/ul (aOR 1.4, 95% C.I. 1.07–1.82) were associated with risk of significant renal impairment (ii) In 149 consecutive patients, urine analysis had poor sensitivity and specificity for detecting impaired renal function.

Conclusion

In this rural African setting, significant renal impairment is uncommon in patients initiating antiretrovirals. Urine analysis alone may be inadequate for identification of those with impaired renal function where resources for biochemistry are limited.
Agriculture and the promotion of insect pests: rice cultivation in river floodplains and malaria vectors in The Gambia
Authors: Jarju Lamin BS , Fillinger Ulrike , Green Clare , Louca Vasilis , Majambere Silas , Lindsay Steven W
Published: August 2009

Background

Anthropogenic modification of natural habitats can create conditions in which pest species associated with humans can thrive. In order to mitigate for these changes, it is necessary to determine which aspects of human management are associated with the promotion of those pests. Anopheles gambiae, the main Africa malaria vector, often breeds in rice fields. Here the impact of the ancient practice of 'swamp rice' cultivation, on the floodplains of the Gambia River, on the production of anopheline mosquitoes was investigated.

Methods

Routine surveys were carried out along 500 m transects crossing rice fields from the landward edge of the floodplains to the river during the 2006 rainy season. Aquatic invertebrates were sampled using area samplers and emergence traps and fish sampled using nets. Semi-field experiments were used to investigate whether nutrients used for swamp rice cultivation affected mosquito larval abundance.

Results

At the beginning of the rainy season rice is grown on the landward edge of the floodplain; the first area to flood with fresh water and one rich in cattle dung. Later, rice plants are transplanted close to the river, the last area to dry out on the floodplain. Nearly all larval and adult stages of malaria vectors were collected 0–100 m from the landward edge of the floodplains, where immature rice plants were grown. These paddies contained stagnant freshwater with high quantities of cattle faeces. Semi-field studies demonstrated that cattle faeces nearly doubled the number of anopheline larvae compared with untreated water.

Conclusion

Swamp rice cultivation creates ideal breeding sites for malaria vectors. However, only those close to the landward edge harboured vectors. These sites were productive since they were large areas of standing freshwater, rich in nutrients, protected from fish, and situated close to human habitation, where egg-laying mosquitoes from the villages had short distances to fly. The traditional practice of 'swamp rice' cultivation uses different bodies of water on the floodplains to cultivate rice during the rainy season. A consequence of this cultivation is the provizion of ideal conditions for malaria vectors to thrive. As the demand for locally-produced rice grows, increased rice farming will generate great numbers of vectors; emphasizing the need to protect local communities against malaria.
Effect of ageing on CMV-specific CD8 T cells from CMV seropositive healthy donors
Authors: Pita-Lopez María Luisa , Gayoso Inmaculada , DelaRosa Olga , Casado Javier G , Alonso Corona , Muñoz-Gomariz Elisa , Tarazona Raquel , Solana Rafael
Published: August 2009

Background

Ageing is associated with changes in the immune system with substantial alterations in T-lymphocyte subsets. Cytomegalovirus (CMV) is one of the factors that affect functionality of T cells and the differentiation and large expansions of CMV pp65-specific T cells have been associated with impaired responses to other immune challenges. Moreover, the presence of clonal expansions of CMV-specific T cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious diseases in the elderly. In this study, we analyse the effect of ageing on the phenotype and frequency of CMV pp65-specific CD8 T cell subsets according to the expression of CCR7, CD45RA, CD27, CD28, CD244 and CD85j.

Results

Peripheral blood from HLA-A2 healthy young, middle-aged and elderly donors was analysed by multiparametric flow cytometry using the HLA-A*0201/CMV pp65495–504 (NLVPMVATV) pentamer and mAbs specific for the molecules analysed. The frequency of CMV pp65-specific CD8 T cells was increased in the elderly compared with young and middle-aged donors. The proportion of naïve cells was reduced in the elderly, whereas an age-associated increase of the CCR7null effector-memory subset, in particular those with a CD45RAdim phenotype, was observed, both in the pentamer-positive and pentamer-negative CD8 T cells. The results also showed that most CMV pp65-specific CD8 T cells in elderly individuals were CD27/CD28 negative and expressed CD85j and CD244.

Conclusion

The finding that the phenotype of CMV pp65-specific CD8 T cells in elderly individuals is similar to the predominant phenotype of CD8 T cells as a whole, suggests that CMV persistent infections contributes to the age-related changes observed in the CD8 T cell compartment, and that chronic stimulation by other persistent antigens also play a role in T cell immunosenescence. Differences in subset distribution in elderly individuals showing a decrease in naive and an increase in effector-memory CD8 T cells may be relevant in the age-associated defective immune response.
Kidney retrieval after sudden out of hospital refractory cardiac arrest: a cohort of uncontrolled non heart beating donors
Authors: Fieux Fabienne , Losser Marie-Reine , Bourgeois Eric , Bonnet Francine , Marie Olivier , Gaudez François , Abboud Imad , Donay Jean-Luc , Roussin France , Mourey François , Adnet Frédéric , Jacob Laurent
Published: August 2009

Introduction

To counter the shortage of kidney grafts in France, a non heart beating donor (NHBD) program has recently been implemented. The aim of this study was to describe this pilot program for kidney retrieval from "uncontrolled" NHBD meaning those for whom attempts of resuscitation after a witnessed out-of-hospital cardiac arrest (CA) have failed (Maastricht 1 and 2), in a centre previously trained for retrieval from brain dead donors.

Methods

A prospective, monocentric, descriptive study concerning NHBD referred to our institution from February 2007 to June 2008. The protocol includes medical transport of refractory CA under mechanical ventilation and external cardiac massage, kidney protection by insertion of an intraaortic double-balloon catheter (DBC) with perfusion of a hypothermic solution, kidney retrieval and kidney preservation in a hypothermic pulsatile perfusion machine.

Results

122 potential NHBD were referred to our institution after a mean resuscitation attempt of 35 minutes (20–95). Regarding the contraindications, 63 were finally accepted and 56 had the DBC inserted. Organ retrieval was performed in 27 patients (43%) and 31 kidneys out of the 54 procured (57%) have been transplanted. Kidney transplantation exclusion was related to family refusal (n = 15), past medical history, time constraints, viral serology, high vascular ex vivo resistance of the graft and macroscopic abnormalities. The 31 kidneys exhibited an expected high delayed graft function rate (92%). Despite these initial results transplanted kidney had good creatinine clearance at six months (66 ± 24 ml/min) with a 89% graft survival rate at six months.

Conclusions

This study shows the feasibility and efficacy of an organ procurement program targeting NHBD allowing a 10% increase in the kidney transplantation rate over 17 months. With a six months follow-up period, the results of transplanted kidney function were excellent.
Toward a Science of Exceptional Achievement
Authors: Ericsson K. Anders , Nandagopal Kiruthiga , Roring Roy W.
Published: August 2009

Exceptional performance is frequently attributed to genetic differences in talent. Since Sir Francis Galton's book, Hereditary Genius, many scientists have cited heritable factors that set limits of performance and only allow some individuals to attain exceptional levels. However, thus far these accounts have not explicated the causal processes involved in the activation and expression of unique genes in DNA that lead to the emergence of distinctive physiological attributes and cognitive capacities (innate talent). This article argues on the basis of our current knowledge that it is possible to account for the development of elite performance among healthy children without recourse to innate talent (genetic endowment)—excepting the innate determinants of body size. Our account is based on the expert‐performance approach and proposes that the distinctive characteristics of exceptional performers are the result of adaptations to extended and intense practice activities that selectively activate dormant genes that are contained within all healthy individuals’ DNA. Furthermore, the theoretical framework of expert performance explains the apparent emergence of early talent by identifying factors that influence starting ages for training and the accumulated engagement in sustained extended deliberate practice, such as motivation, parental support, and access to the best training environments and teachers. In sum, our empirical investigations and extensive reviews show that the development of expert performance will be primarily constrained by individuals’ engagement in deliberate practice and the quality of the available training resources.
Does Meditation Enhance Cognition and Brain Plasticity?
Authors: Xiong Glen L. , Doraiswamy P. Murali
Published: August 2009

Meditation practices have various health benefits including the possibility of preserving cognition and preventing dementia. While the mechanisms remain investigational, studies show that meditation may affect multiple pathways that could play a role in brain aging and mental fitness. For example, meditation may reduce stress‐induced cortisol secretion and this could have neuroprotective effects potentially via elevating levels of brain derived neurotrophic factor (BDNF). Meditation may also potentially have beneficial effects on lipid profiles and lower oxidative stress, both of which could in turn reduce the risk for cerebrovascular disease and age‐related neurodegeneration. Further, meditation may potentially strengthen neuronal circuits and enhance cognitive reserve capacity. These are the theoretical bases for how meditation might enhance longevity and optimal health. Evidence to support a neuroprotective effect comes from cognitive, electroencephalogram (EEG), and structural neuroimaging studies. In one cross‐sectional study, meditation practitioners were found to have a lower age‐related decline in thickness of specific cortical regions. However, the enthusiasm must be balanced by the inconsistency and preliminary nature of existing studies as well as the fact that meditation comprises a heterogeneous group of practices. Key future challenges include the isolation of a potential common element in the different meditation modalities, replication of existing findings in larger randomized trials, determining the correct “dose,” studying whether findings from expert practitioners are generalizable to a wider population, and better control of the confounding genetic, dietary and lifestyle influences.
America's Exceptional Comparabilities: An Instance of World Literature
Authors: KADIR DJELAL
Published: August 2009

Marked by exceptionalism as endemic characteristic, America's cultures, literary and otherwise, conform to the history of humans globally. American (especially U.S. American) exceptionalism is a paradoxical trait of inevitable conformity. Thus, America's self-estimation as incomparable may be its most comparable trait. This essay explores some of the diverse symptoms and literary manifestations of this perennial hemispheric irony.
The Return of the Decolonized: The Legacies of Leopoldo Zea's Philosophy of History for Comparative American Studies
Authors: PRADO IGNACIO M. SÁNCHEZ
Published: August 2009

Leopoldo Zea's philosophy of history constitutes a cogent interrogation of the colonial legacy in Mexico and thus also serves to demonstrate the importance of Latin America as a site of theoretical enunciation. This essay addresses Zea's early work on Mexico and his “Discourse on Margination and Barbarism,” putting them in dialogue with Gloria Anzaldúa's more recent theoretical engagement of border culture in order to assess their value as models for what Raewyn Connell calls “Southern theory.” This essay concludes with a discussion of several theorists who present models of comparative American studies compatible with the Southern theory discussed in the previous pages.
Responses to temperature variation: integration of thermoregulation and metabolism in vertebrates
Authors: Seebacher Frank
Published: August 2009

Many vertebrates regulate their body temperature in response to thermal variability of the environment. Endotherms maintain relatively stable body temperatures by adjusting metabolic heat production in response to varying environmental heat loads. Although most ectotherms do not display adaptive thermogenesis, they do acclimate cellular metabolism to compensate for environmental temperature variation. The components of the thermoregulatory systems in endotherms and ectotherms are evolutionarily conserved, and I suggest that metabolic acclimation in ectotherms relies on the same regulatory pathways as adaptive thermogenesis in endotherms. Both groups rely on transient receptor potential ion channels to sense environmental temperatures. Thermosensory (afferent) information is relayed to the hypothalamus, which initiates a sympathetic efferent response. Cardiovascular responses to heat are similar in ectothermic crocodiles and in mammals, and are mediated by the autonomic nervous system in both cases. The sympathetic nervous system also modulates cellular metabolism by inducing expression of the transcriptional regulator peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α), which interacts with a range of transcription factors that control glycolysis, fatty acid oxidation, gluconeogenesis, mitochondrial biogenesis and bioenergetics, and metabolic rate. PGC-1α is best known from mammalian model species but there is increasing evidence that it is also instrumental in non-mammalian vertebrates. Hence, endothermic adaptive thermogenesis may result from the same regulatory pathways as ectothermic metabolic acclimation, and both could be considered as adaptive metabolic responses to temperature variation.
Endurance capacity of mice selectively bred for high voluntary wheel running
Authors: Meek Thomas H. , Lonquich Brian P. , Hannon Robert M. , Garland Theodore
Published: August 2009

Mice from four lines bred for high voluntary wheel activity run ∼3-fold more revolutions per day and have elevated maximal oxygen consumption during forced treadmill exercise, as compared with four unselected control (C) lines. We hypothesized that these high runner (HR) lines would have greater treadmill endurance-running capacity. Ninety-six mice from generation 49 were familiarized with running on a motorized treadmill for 3 days. On days 4 and 5, mice were given an incremental speed test (starting at 20 m min–1, increased 1.5 m min–1 every 2 min)and endurance was measured as the total time or distance run to exhaustion. Blood samples were taken to measure glucose and lactate concentrations at rest during the photophase, during peak nightly wheel running, and immediately following the second endurance test. Individual differences in endurance time were highly repeatable between days (r=0.79), and mice tended to run longer on the second day (paired t-test, P<0.0001). Blood glucose following the treadmill test was low for all animals (∼53 mg dl–1) and lactate was high (∼6.5 mmol l–1), suggesting that exhaustion occurred. The HR lines had significantly higher endurance than the C lines (1-tailed P<0.05),whether or not body mass was used as a covariate in the analysis. The relationship between line means for wheel running and treadmill endurance differed between the sexes, reinforcing previous studies that indicate sex-specific responses to selective breeding. HR mice appear to have a higher endurance capacity than reported in the literature for inbred strains of mice or transgenics intended to enhance endurance.
Orientation of lizards in a Morris water-maze: roles of the sun compass and the parietal eye
Authors: Foà Augusto , Basaglia Francesca , Beltrami Giulia , Carnacina Margherita , Moretto Elisa , Bertolucci Cristiano
Published: August 2009

The present study examined for the first time whether a Morris water-maze can be used to explore compass and other orientation mechanisms in the ruin lizard Podarcis sicula. In the open field, during sunny days, lizards were individually trained to swim from the center of the water maze onto a hidden platform (the goal), positioned at the periphery of the maze in a single compass direction. The goal was invisible because it was placed just beneath the water surface and the water was rendered opaque. The results showed that lizards learn to swim directly towards the hidden goal under the sun in the absence of visual feature cues. We further examined whether the observed orientation response would be due to lizards learning the spatial position of the goal relative to the sun's azimuth, i.e. to the use of a time-compensated sun compass. Lizards reaching learning criteria were subjected to 6 h clock-shift (fast or slow), and tested for goal orientation in the Morris water-maze. Results demonstrated that the learned orientation response is mediated by a time-compensated sun compass. Further investigations provided direct evidence that in ruin lizards an intact parietal eye is required to perform goal orientation under the sun inside a Morris water-maze,and that other brain photoreceptors, like the pineal or deep brain photoreceptors, are not involved in orientation.
Information from the geomagnetic field triggers a reduced adrenocortical response in a migratory bird
Authors: Henshaw Ian , Fransson Thord , Jakobsson Sven , Jenni-Eiermann Susanne , Kullberg Cecilia
Published: August 2009

Long-distance migrants regularly pass ecological barriers, like the Sahara desert, where extensive fuel loads are necessary for a successful crossing. A central question is how inexperienced migrants know when to put on extensive fuel loads. Beside the endogenous rhythm, external cues have been suggested to be important. Geomagnetic information has been shown to trigger changes in foraging behaviour and fuel deposition rate in migratory birds. The underlying mechanism for these adjustments, however, is not well understood. As the glucocorticoid hormone corticosterone is known to correlate with behaviour and physiology related to energy regulation in birds, we here investigated the effect of geomagnetic cues on circulating corticosterone levels in a long-distance migrant. Just as in earlier studies, juvenile thrush nightingales (Luscinia luscinia) caught during autumn migration and exposed to the simulated geomagnetic field of northern Egypt increased food intake and attained higher fuel loads than control birds experiencing the ambient magnetic field of southeast Sweden. Our results further show that experimental birds faced a reduced adrenocortical response compared with control birds, thus for the first time implying that geomagnetic cues trigger changes in hormonal secretion enabling appropriate behaviour along the migratory route.
Predicting the rate of oxygen consumption from heart rate in barnacle geeseBranta leucopsis: effects of captivity and annual changes in body condition
Authors: Portugal Steven J. , Green Jonathan A. , Cassey Phillip , Frappell Peter B. , Butler Patrick J.
Published: August 2009

Quantifying a relationship between heart rate (fH) and rate of oxygen consumption(V̇O2) allows the estimation of V̇O2from fH recordings in free-ranging birds. It has been proposed that this relationship may vary throughout an animal's annual cycle,due to changes in physiological status. Barnacle geese, Branta leucopsis, provide an ideal model to test this hypothesis, as they exhibit significant intra-annual variability in body mass, body composition and abdominal temperature, even in captivity. Heart rate data loggers were implanted in 14 captive barnacle geese, and at six points in the year the relationship between fH and V̇O2 was determined. The fH/V̇O2relationship was also determined in seven moulting wild barnacle geese to examine whether relationships from captive animals might be applicable to wild animals. In captive barnacle geese, the fH/V̇O2relationship was significantly different only between two out of the six periods when the relationship was determined (late September–early October and November). Accounting for changes in physiological parameters such as body mass, body composition and abdominal temperature did not eliminate this difference. The relationship between fH and V̇O2 obtained from wild geese was significantly different from all of the relationships derived from the captive geese, suggesting that it is not possible to apply calibrations from captive birds to wild geese. However, the similarity of the fH and V̇O2 relationship derived during moult in the captive geese to those during the remainder of the annual cycle implies it is not unreasonable to assume that the relationship between fH/V̇O2during moult in the wild geese is indicative of the relationship throughout the remainder of the annual cycle.