bluuebunny/crossref_metadata_2025 huggingface dataset:
Invariant NKT Cells Inhibit Autoreactive B Cells in a Contact- and CD1d-Dependent Manner
Authors: Yang Jun-Qi , Wen Xiangshu , Kim Peter J. , Singh Ram Raj
Published: January 2011

Autoantibody production is a hallmark of autoimmune diseases, such as lupus and rheumatoid arthritis. Accumulating evidence suggests a role of invariant NKT (iNKT) cells in their pathogenesis. Mechanisms underlying the role of iNKT cells in these diseases, however, remain unclear. In this study, we show that iNKT cells suppress IgG anti-DNA Ab and rheumatoid factor production and reduce IL-10–secreting B cells in a contact-dependent manner, but increase total IgG production and enhance activation markers on B cells via soluble factors. In vivo reconstitution with iNKT cells also reduces autoantibody production in iNKT-deficient mice and in SCID mice implanted with B cells. Using an anti-DNA transgenic model, we found that autoreactive B cells spontaneously produce IL-10 and are activated in vivo. In the presence of activated iNKT cells, these autoreactive B cells are selectively reduced, whereas nonautoreactive B cells are markedly activated. Because iNKTs recognize CD1d, we reasoned that CD1d might play a role in the differential regulation of autoreactive versus nonautoreactive B cells by iNKT cells. Indeed, autoreactive B cells express more CD1d than nonautoreactive B cells, and CD1d deficiency in lupus mice exacerbates autoantibody production and enhances Ab response to a self-peptide but not to a foreign peptide. Importantly, iNKT cells fail to inhibit autoantibody production by CD1d-deficient B cells. Thus, iNKT cells inhibit autoreactive B cells in a contact- and CD1d-dependent manner but activate nonautoreactive B cells via cytokines. Such ability of iNKTs to suppress autoantibody production, without causing global suppression of B cells, has important implications for the development of iNKT-based therapy for autoimmune diseases.
Foxp3+ Regulatory T Cells Control Humoral Autoimmunity by Suppressing the Development of Long-Lived Plasma Cells
Authors: Jang Eunkyeong , Cho Wang Sik , Cho Mi-La , Park Hyun-Joo , Oh Hye-Joa , Kang Sang Mee , Paik Doo-Jin , Youn Jeehee
Published: January 2011

Foxp3+ regulatory T cells (Tregs) are crucial for maintaining T cell tolerance, but their role in humoral autoimmunity remains unclear. To address this, we combined a model of autoantibody-dependent arthritis (K/BxN) with Foxp3 mutant scurfy mice to generate Treg-deficient K/BxN mice, referred to as K/BxNsf mice. The disease symptoms of K/BxNsf mice were exacerbated, and this coincided with increases in extrafollicular Th cells, follicular Th cells, and germinal centers. Surprisingly, the K/BxNsf mice exhibited an abnormal accumulation of mature plasma cells in their spleens and a corresponding loss of bone marrow plasma cells. The plasma cells were unresponsive to the bone marrow homing chemokine CXCL12, despite normal expression of the chemokine receptor CXCR4. Importantly, they were long-lived and less susceptible to the cytotoxic action of cyclophosphamide. They also expressed less FcγRIIb and were less apoptotic in response to autoantigen–autoantibody immune complexes. This suggests that Tregs control plasma cell susceptibility to cell death induced by engagement of FcγRIIb with immune complexes. Direct cytotoxic effects of Tregs also contribute to the death of plasma cells. Thus, our results reveal that Tregs suppress the emergence of long-lived splenic plasma cells by affecting plasma cell-autonomous mechanisms as well as T cell help, thereby avoiding the persistence of humoral autoimmunity.
Although Divergent in Residues of the Peptide Binding Site, Conserved Chimpanzee Patr-AL and Polymorphic Human HLA-A*02 Have Overlapping Peptide-Binding Repertoires
Authors: Gleimer Michael , Wahl Angela R. , Hickman Heather D. , Abi-Rached Laurent , Norman Paul J. , Guethlein Lisbeth A. , Hammond John A. , Draghi Monia , Adams Erin J. , Juo Sean , Jalili Roxana , Gharizadeh Baback , Ronaghi Mostafa , Garcia K. Christopher , Hildebrand William H. , Parham Peter
Published: January 2011

Patr-AL is an expressed, non-polymorphic MHC class I gene carried by ∼50% of chimpanzee MHC haplotypes. Comparing Patr-AL+ and Patr-AL− haplotypes showed Patr-AL defines a unique 125-kb genomic block flanked by blocks containing classical Patr-A and pseudogene Patr-H. Orthologous to Patr-AL are polymorphic orangutan Popy-A and the 5′ part of human pseudogene HLA-Y, carried by ∼10% of HLA haplotypes. Thus, the AL gene alternatively evolved in these closely related species to become classical, nonclassical, and nonfunctional. Although differing by 30 aa substitutions in the peptide-binding α1 and α2 domains, Patr-AL and HLA-A*0201 bind overlapping repertoires of peptides; the overlap being comparable with that between the A*0201 and A*0207 subtypes differing by one substitution. Patr-AL thus has the A02 supertypic peptide-binding specificity. Patr-AL and HLA-A*0201 have similar three-dimensional structures, binding peptides in similar conformation. Although comparable in size and shape, the B and F specificity pockets of Patr-AL and HLA-A*0201 differ in both their constituent residues and contacts with peptide anchors. Uniquely shared by Patr-AL, HLA-A*0201, and other members of the A02 supertype are the absence of serine at position 9 in the B pocket and the presence of tyrosine at position 116 in the F pocket. Distinguishing Patr-AL from HLA-A*02 is an unusually electropositive upper face on the α2 helix. Stimulating PBMCs from Patr-AL− chimpanzees with B cells expressing Patr-AL produced potent alloreactive CD8 T cells with specificity for Patr-AL and no cross-reactivity toward other MHC class I molecules, including HLA-A*02. In contrast, PBMCs from Patr-AL+ chimpanzees are tolerant of Patr-AL.
c-Maf–Dependent Growth of Mycobacterium tuberculosis in a CD14hi Subpopulation of Monocyte-Derived Macrophages
Authors: Dhiman Rohan , Bandaru Anuradha , Barnes Peter F. , Saha Sudipto , Tvinnereim Amy , Nayak Ramesh C. , Paidipally Padmaja , Valluri Vijaya Lakshmi , Mohan Rao L. Vijaya , Vankayalapati Ramakrishna
Published: January 2011

Macrophages are a major component of the innate immune response, comprising the first line of defense against various intracellular pathogens, including Mycobacterium tuberculosis. In this report, we studied the factors that regulate growth of M. tuberculosis H37Rv in subpopulations of human monocyte-derived macrophages (MDMs). In healthy donors, M. tuberculosis H37Rv grew 5.6-fold more rapidly in CD14hi MDMs compared with that in CD14loCD16+ MDMs. Compared with CD14loCD16+ cells, M. tuberculosis H37Rv-stimulated CD14hi monocytes produced more IL-10 and had increased mRNA expression for c-Maf, a transcription factor that upregulates IL-10 gene expression. c-Maf small interfering RNA (siRNA) inhibited IL-10 production and growth of M. tuberculosis in CD14hi cells. Compared with CD14loCD16+ monocytes, M. tuberculosis H37Rv-stimulated CD14hi cells had increased expression of 22 genes whose promoters contained a c-Maf binding site, including hyaluronan synthase 1 (HAS1). c-Maf siRNA inhibited HAS1 expression in M. tuberculosis-stimulated CD14hi monocytes, and HAS1 siRNA inhibited growth of M. tuberculosis in CD14hi MDMs. M. tuberculosis H37Rv upregulated expression of HAS1 protein and its product, hyaluronan, in CD14hi MDMs. We conclude that M. tuberculosis grows more rapidly in CD14hi than in CD14loCD16+ MDMs because CD14hi cells have increased expression of c-Maf, which increases production of two key factors (hyaluronan and IL-10) that promote growth of M. tuberculosis.
Confirmed Vivax Resistance to Chloroquine and Effectiveness of Artemether-Lumefantrine for the Treatment of Vivax Malaria in Ethiopia
Authors: Yohannes Ambachew M. , Teklehaimanot Awash , Bergqvist Yngve , Ringwald Pascal
Published: January 2011

Chloroquine (CQ) is still the drug of choice for the treatment of vivax malaria in Ethiopia, whereas artemether-lumefantrine (AL) is for falciparum malaria. In this setting, clinical malaria cases are treated with AL. This necessitated the need to assess the effectiveness of AL for the treatment of Plasmodium vivax with CQ as a comparator. A total of 57 (80.3%) and 75 (85.2%) cases treated with CQ or AL, respectively, completed the study in an outpatient setting. At the end of the follow-up period of 28 days, a cumulative incidence of treatment failure of 7.5% (95% confidence interval [CI] = 2.9–18.9%) for CQ and 19% (95% CI = 11–31.6%) for AL was detected. CQ resistance was confirmed in three of five CQ treatment failures cases. The effectiveness of AL seems lower than CQ; however, the findings were not conclusive, because the AL evening doses were not supervised.
Association of Anthropogenic Land Use Change and Increased Abundance of the Chagas Disease Vector Rhodnius pallescens in a Rural Landscape of Panama
Authors: Gottdenker Nicole L. , Calzada José E. , Saldaña Azäel , Carroll C. Ronald
Published: January 2011

Anthropogenic disturbance is associated with increased vector-borne infectious disease transmission in wildlife, domestic animals, and humans. The objective of this study was to evaluate how disturbance of a tropical forest landscape impacts abundance of the triatomine bug Rhodnius pallescens, a vector of Chagas disease, in the region of the Panama Canal in Panama. Rhodnius pallescens was collected (n = 1,186) from its primary habitat, the palm Attalea butyracea, in five habitat types reflecting a gradient of anthropogenic disturbance. There was a high proportion of palms infested with R. pallescens across all habitat types (range = 77.1–91.4%). Results show that disturbed habitats are associated with increased vector abundance compared with relatively undisturbed habitats. Bugs collected in disturbed sites, although in higher abundance, tended to be in poor body condition compared with bugs captured in protected forest sites. Abundance data suggests that forest remnants may be sources for R. pallescens populations within highly disturbed areas of the landscape.
New Spotted Fever Group Rickettsia in a Rhipicephalus turanicus Tick Removed from a Child in Eastern Sicily, Italy
Authors: Eremeeva Marina E. , Stromdahl Ellen Y.
Published: January 2011

A new genotype of spotted fever group Rickettsia (SFGR) was identified in Rhipicephalus turanicus from eastern Sicily. On the basis of current molecular criteria, the genetic characteristics obtained from multiple locus sequence typing satisfy the requirements for Candidatus status of this SFGR. Further detection and identification of this SFGR during entomological and clinical surveys will be required to establish the prevalence of this Rickettsia and its potential pathogenicity for humans.
Malarial Retinopathy in Bangladeshi Adults
Authors: Sayeed Abdullah Abu , Maude Richard J. , Hasan Mahtab Uddin , Mohammed Noor , Hoque M. Gofranul , Dondorp Arjen M. , Faiz M. Abul
Published: January 2011

To establish if assessment of malarial retinopathy in adult malaria using ophthalmoscopy by non-ophthalmologists has clinical and prognostic significance, 210 Bangladeshi adults were assessed by both direct and indirect ophthalmoscopy; 20 of 20 healthy subjects and 20 of 20 patients with vivax malaria showed no retinal changes, whereas in patients with falciparum malaria, indirect ophthalmoscopy revealed malarial retinopathy (predominantly retinal hemorrhages) in 18 of 21 (86%) fatal, 31 of 75 (41%) cerebral, 16 of 64 (25%) non-cerebral but severe, and 1 of 31 (3%) uncomplicated cases. Direct ophthalmoscopy missed retinopathy in one of these cases and found fewer retinal hemorrhages (mean difference = 3.09; 95% confidence interval = 1.50–4.68; P < 0.0001). Severity of retinopathy increased with severity of disease (P for trend < 0.0001), and renal failure, acidosis, and moderate/severe retinopathy were independent predictors of mortality by both ophthalmoscopic techniques. Direct ophthalmoscopy by non-ophthalmologists is an important clinical tool to aid diagnosis and prognosis in adults with severe malaria, and indirect ophthalmoscopy by non-ophthalmologists, although more sensitive, provides minimal additional prognostic information.
Evaluation of Two rK39 Dipstick Tests, Direct Agglutination Test, and Indirect Fluorescent Antibody Test for Diagnosis of Visceral Leishmaniasis in a New Epidemic Site in Highland Ethiopia
Authors: Cañavate Carmen , Herrero Merce , Nieto Javier , Cruz Israel , Chicharro Carmen , Aparicio Pilar , Mulugeta Abate , Argaw Daniel , Blackstock Anna J. , Alvar Jorge , Bern Caryn
Published: January 2011

We assessed the performance characteristics of two rK39 immunochromatographic tests, a direct agglutination test (DAT), and an indirect immunofluorescent antibody test (IFAT) in the site of a new epidemic of visceral leishmaniasis (VL) in northwestern Ethiopia. The study population was composed of 179 patients with suspected VL and 67 controls. The sensitivities of Kalazar Detect®, DiaMed-IT Leish®, DAT, and IFAT in 35 polymerase chain reaction–confirmed VL cases were 94.3%, 91.4%, 91.4%, and 100%, respectively, and the specificities were 98.5%, 94%, 98.5%, and 98.5%, respectively. In a Bayesian latent class analysis of all 246 specimens, the estimated sensitivities were 90.5%, 89%, 88.8%, and 96% for Kalazar Detect®, DiaMed-IT Leish®, DAT, and IFAT, respectively; DAT showed the highest estimated specificity (97.4%). Both rK39 immunochromatographic tests perform as well as DAT, and are suitable for VL diagnosis in first-level health centers in this area of Ethiopia.
Amebiasis among Persons Who Sought Voluntary Counseling and Testing for Human Immunodeficiency Virus Infection: A Case-Control Study
Authors: Hung Chien-Ching , Wu Pei-Ying , Chang Sui-Yuan , Ji Dar-Der , Sun Hsin-Yun , Liu Wen-Chun , Wu Cheng-Hsin , Chang Shan-Chwen
Published: January 2011

This case-control study aimed to characterize the factors associated with amebiasis, defined as presence of anti-Entamoeba histolytica antibody titers of ≧ 128 by indirect hemagglutination assay, among persons seeking voluntary counseling and testing (VCT) for human immunodeficiency virus (HIV) infection. Between April 2006 and September 2009, 57 of 4,802 persons (1.2%) seeking VCT services were seropositive for E. histolytica infection. Compared with 228 seronegative controls, case subjects were older (odds ratio [OR] for per 1-year increase, 1.098; 95% confidence interval [CI], 1.036, 1.165), less likely to hold bachelor degree or higher (OR, 0.359; 95% CI, 0.152, 0.846), and were more likely to be men who have sex with men (MSM) (OR, 8.382; 95% CI, 2.050, 34.266) and have oral-anal sex (OR, 4.016; 95% CI, 1.711, 9.427) in multiple logistic regression analysis. The MSM, fecal-oral contamination, lower educational achievement, and older age were associated with increased risk for amebiasis among persons seeking VCT for HIV infection.
Iron Homeostasis in Mother and Child during Placental Malaria Infection
Authors: Van Santen Susanne , de Mast Quirijn , Luty Adrian J. F. , Wiegerinck Erwin T. , Van der Ven Andre J. A. M. , Swinkels Dorine W.
Published: January 2011

In malaria-endemic areas, iron deficiency and placental Plasmodium falciparum infection commonly coexist. In primigravidae and their newborns, hepcidin and other iron parameters were evaluated in groups and classified according to placental P. falciparum and maternal anemia status. Mothers had relatively high hepcidin levels considering their low iron status. In cord blood, levels of hepcidin, hemoglobin, and other iron parameters were also similar for groups. We conclude that maternal hepcidin is not significantly altered as a function of placental infection and/or anemia. Importantly, fetal hemoglobin and iron status were also unaffected, regardless of the presence of placental infection or maternal anemia.
Expansion of Visceral Leishmaniasis to the Western Hilly Part of Nepal
Authors: Pandey Basu Dev , Pun Sher Bahadur , Kaneko Osamu , Pandey Kishor , Hirayama Kenji
Published: January 2011

We report the first case of visceral leishmaniasis (VL) from the non-endemic western hilly region of Nepal. The patient presented with a history of high-grade fever, abdominal distension, anemia, and weight loss. The case was confirmed as VL by microscopical detection of the Leishmania species amastigote in bone marrow aspiration and by a positive result for the rK39 test. The patient was treated with 0.5–1.0 mg/kg of Amphotericin B for 14 days (total of 405 mg), and amastigotes were negative on discharge. Five months later, this patient again developed fever, abdominal distension, and anemia. Clinical and hematological examinations suggested a relapse of VL. The patient was treated with 1 mg/kg of Amphotericin B for 18 days (total of 515 mg) and was clinically improved on discharge.
Metabonomic Investigation of Single and Multiple Strain Trypanosoma brucei brucei Infections
Authors: Li Jia V. , Saric Jasmina , Wang Yulan , Utzinger Jürg , Holmes Elaine , Balmer Oliver
Published: January 2011

Although co-infections are common and can have important epidemiologic and evolutionary consequences, studies exploring biochemical effects of multiple-strain infections remain scarce. We studied metabolic responses of NMRI mice to Trypanosoma brucei brucei single (STIB777AE-Green1 or STIB246BA-Red1) and co-infections using a 1H nuclear magnetic resonance (NMR) spectroscopy-based metabolic profiling strategy. All T. b. brucei infections caused an alteration in urinary biochemical composition by day 4 postinfection, characterized by increased concentrations of 2-oxoisocaproate, D-3-hydroxybutyrate, lactate, 4-hydroxyphenylacetate, phenylpyruvate, and 4-hydroxyphenylpyruvate, and decreased levels of hippurate. Although there were no marked differences in metabolic signatures observed in the mouse infected with a single or dual strain of T. b. brucei, there was a slower metabolic response in mice infected with T. b. brucei green strain compared with mice infected with either the red strain or both strains concurrently. Pyruvate, phenylpyruvate, and hippurate were correlated with parasitemia, which might be useful in monitoring responses to therapeutic interventions.
Venomous Snake Bites in Japan
Authors: Yasunaga Hideo , Horiguchi Hiromasa , Kuwabara Kazuaki , Hashimoto Hideki , Matsuda Shinya
Published: January 2011

Few reliable data are available on the incidence of snake bites in developing and developed nations. Insufficient epidemiologic data have hindered the recognition of snake bite as an important public health issue. We verified statistics of snake bites (mamushi and habu bites) in Japan by using a currently available, nationally representative, hospital-based database. We identified 1,670 inpatients with snake bites from 404 hospitals during July 1–December 31 in 2007 and 2008. More than 60% were males, the average age was 60.1 years, and the in-hospital mortality rate was 0.2%. The incidence of mamushi bite, distributed between latitudes 30°N and 46°N, was estimated to be 1.67 bites/100,000/6 months. It is important to continue collecting all available data to monitor the trends of this life-threatening disease.
A Species-Specific Approach to the Use of Non-Antimony Treatments for Cutaneous Leishmaniasis
Authors: Ramanathan Roshan , Talaat Kawsar R. , Fedorko Daniel P. , Mahanty Siddhartha , Nash Theodore E.
Published: January 2011

We used a species-specific approach to treat 10 patients with cutaneous leishmaniasis diagnosed using polymerase chain reaction. Non-antimony treatments (oral miltefosine, ketoconazole, and liposomal amphotericin B) were chosen as an alternative to pentavalent antimony drugs based on likely or proven drug efficacy against the infecting species. Leishmania Viannia panamensis was diagnosed in three patients and treated successfully with oral ketoconazole. Miltefosine treatment cured two patients with L. infantum chagasi. A wide variety of Leishmania responded to liposomal amphotericin B administered for 5–7 days. Three patients with L. V. braziliensis, one patient with L. tropica, and two patients with L. infantum chagasi were treated successfully. One person with L. V. braziliensis healed slowly because of a resistant bacterial superinfection, and a second patient with L. infantum chagasi relapsed and was retreated with miltefosine. These drugs were reasonably well-tolerated. In this limited case series, alternative non-antimony–based regimens were convenient, safe, and effective.
High Throughput Multiplex Assay for Species Identification of Papua New Guinea Malaria Vectors: Members of the Anopheles punctulatus (Diptera: Culicidae) Species Group
Authors: Henry-Halldin Cara N. , Reimer Lisa , Thomsen Edward , Koimbu Gussy , Zimmerman Allison , Keven John B. , Dagoro Henry , Hetzel Manuel W. , Mueller Ivo , Siba Peter , Zimmerman Peter A.
Published: January 2011

Malaria and filariasis are transmitted in the Southwest Pacific region by Anopheles punctulatus sibling species including An. punctulatus, An. koliensis, the An. farauti complex 1–8 (includes An. hinesorum [An. farauti 2], An. torresiensis [An. farauti 3]). Distinguishing these species from each other requires molecular diagnostic methods. We developed a multiplex polymerase chain reaction (PCR)–based assay specific for known species-specific nucleotide differences in the internal transcribed spacer 2 region and identified the five species most frequently implicated in transmitting disease (An. punctulatus, An. koliensis, An. farauti 1, An. hinesorum, and An. farauti 4). A set of 340 individual mosquitoes obtained from seven Papua New Guinea provinces representing a variety of habitats were analyzed by using this multiplex assay. Concordance between molecular and morphological diagnosis was 56.4% for An. punctulatus, 85.3% for An. koliensis, and 88.9% for An. farauti. Among 158 mosquitoes morphologically designated as An. farauti, 33 were re-classified by PCR as An. punctulatus, 4 as An. koliensis, 26 as An. farauti 1, 49 as An. hinesorum, and 46 as An. farauti 4. Misclassification results from variable coloration of the proboscis and overlap of An. punctulatus, An. koliensis, the An. farauti 4. This multiplex technology enables further mosquito strain identification and simultaneous detection of microbial pathogens.
Addressing Institutional Amplifiers in the Dynamics and Control of Tuberculosis Epidemics
Authors: Basu Sanjay , Stuckler David , McKee Martin
Published: January 2011

Tuberculosis outbreaks originating in prisons, mines, or hospital wards can spread to the larger community. Recent proposals have targeted these high-transmission institutional amplifiers by improving case detection, treatment, or reducing the size of the exposed population. However, what effects these alternative proposals may have is unclear. We mathematically modeled these control strategies and found case detection and treatment methods insufficient in addressing epidemics involving common types of institutional amplifiers. Movement of persons in and out of amplifiers fundamentally altered the transmission dynamics of tuberculosis in a manner not effectively mitigated by detection or treatment alone. Policies increasing the population size exposed to amplifiers or the per-person duration of exposure within amplifiers potentially worsened incidence, even in settings with high rates of detection and treatment success. However, reducing the total population size entering institutional amplifiers significantly lowered tuberculosis incidence and the risk of propagating new drug-resistant tuberculosis strains.
Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn
Authors: Lin J.-T. , McElroy M. B.
Published: January 2011

Abstract. Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27–33% in annual mean VCD of NO2 prior to the downturn, consistent with an increase of 49% in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005–2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20% from January 2008 to January 2009, close to the reduction of 18% in TPG that occurred over the same interval. A combination of three relatively independent approaches indicates that the economic downturn was responsible for a~reduction in emissions by 9–11% in January 2009 with an additional decrease of 10% attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year.
Large-scale and synoptic meteorology in the South-East Pacific during the observations campaign VOCALS-REx in Spring 2008
Authors: Toniazzo T. , Abel S. J. , Wood R. , Mechoso C. R. , Allen G. , Shaffrey L. C.
Published: January 2011

Abstract. We present a descriptive overview of the meteorology in the south eastern Subtropical Pacific during the VOCALS-REx intensive observations campaign, which took place in October and November 2008. We provide a summary of the day-to-day meteorological and cloud conditions. Our main aim is to provide some broader spatial and temporal meteorological context for the measurements made during VOCALS-REx, attempting to link the large-scale conditions of the atmospheric circulation with the locally observed conditions, also with a view of estimating the representativity of the specific season that was sampled by VOCALS-REx.
Numerical simulations of local circulations and pollution transport over Reunion Island
Authors: Lesouëf D. , Gheusi F. , Delmas R. , Escobar J.
Published: January 2011

Abstract. A series of high-resolution (1 km) numerical simulations with a limited-area numerical model has been performed over Reunion Island. In the dynamical context of a regular maritime flow perturbed by a major topographic obstacle such as Reunion Island, the objectives are to identify the main atmospheric circulations at local-scale over the island and to improve the understanding of local-scale transport and dispersion of pollutants emitted from local sources. To investigate the effects of topography and land surface heating on low-level flows over the island, simulations representative of austral winter were performed in idealized conditions keeping the radiative forcing plus a background east-south-easterly synoptic flux of varying strengths, typical of the prevailing trade-wind conditions. The numerical experiments show mainly that flow splitting of the trade-wind occurs around the island, with enhanced winds blowing along the coast lines parallel to the synoptic flux, due to the lateral constriction of the flow by the island and resulting Venturi effect. Blocking occurs on the island side facing the trade-wind. The north-western area on the leeside is screened from the trade-wind by high mountains, and this enables the development of diurnal thermally-induced circulations, combining downslope and land-breeze at night, and upslope and sea breeze at daytime. Flow splitting is modulated by radiative convergence toward the island at daytime, and divergence from the island at night. Stronger winds than the large-scale trade-wind occur along the coast at daytime (Venturi effect), whereas at night, the trade-wind flow is pushed few kilometres offshore by divergence of cooled air from the land. At night, the trade-wind flow is pushed few kilometres offshore by divergence of cooled air from the land. Consequently, a number of processes of pollution transport and dispersion have been identified. Vortices in the wake of the island were found to cause counterflow circulation and trapping of polluted air masses near the north-western coast. These air masses may in turn be sucked by anabatic wind systems during daytime (upslope and sea breezes) in the cirques and up to the summits of the island, and especially to Piton Maïdo (2200 m) where a new observatory of the Indian Ocean background atmosphere is being built. A "cap effect" above the mountains downstream from the volcano (to the south-east of the island), and especially above Piton Maïdo, might occur in case of development of inland and upslope breezes on the west coast. In this case, air pumped from lower layers may protect the observatory from the volcanic plume forced to pass over a "cap" of low-level air clean of volcanic emissions.
Annual follow-up of gross diffusive carbon dioxide and methane emissions from a boreal reservoir and two nearby lakes in Québec, Canada
Authors: Demarty M. , Bastien J. , Tremblay A.
Published: January 2011

Abstract. Surface water pCO2 and pCH4 measurements were taken in the boreal zone of Québec, Canada, from summer 2006 to summer 2008 in Eastmain 1 reservoir and two nearby lakes. The goal of this follow-up was to evaluate annual greenhouse gas (GHG) emissions, including spring emissions (N.B. gross emissions for reservoir), through flux calculations using the thin boundary layer model. Our measurements underscored the winter CO2 accumulation due to ice cover and the importance of a reliable estimate of spring diffusive emissions as the ice breaks up. We clearly demonstrated that in our systems, diffusive CH4 flux (in terms of CO2 equivalent) were of minor importance in the GHG emissions (without CH4 accumulation under ice), with diffusive CO2 flux generally accounting for more than 95% of the annual diffusive flux. We also noted the extent of spring diffusive CO2 emissions (23% to 52%) in the annual carbon budget.
Seasonal prediction of winter extreme precipitation over Canada by support vector regression
Authors: Zeng Z. , Hsieh W. W. , Shabbar A. , Burrows W. R.
Published: January 2011

Abstract. For forecasting the maximum 5-day accumulated precipitation over the winter season at lead times of 3, 6, 9 and 12 months over Canada from 1950 to 2007, two nonlinear and two linear regression models were used, where the models were support vector regression (SVR) (nonlinear and linear versions), nonlinear Bayesian neural network (BNN) and multiple linear regression (MLR). The 118 stations were grouped into six geographic regions by K-means clustering. For each region, the leading principal components of the winter maximum 5-d accumulated precipitation anomalies were the predictands. Potential predictors included quasi-global sea surface temperature anomalies and 500 hPa geopotential height anomalies over the Northern Hemisphere, as well as six climate indices (the Niño-3.4 region sea surface temperature, the North Atlantic Oscillation, the Pacific-North American teleconnection, the Pacific Decadal Oscillation, the Scandinavia pattern, and the East Atlantic pattern). The results showed that in general the two robust SVR models tended to have better forecast skills than the two non-robust models (MLR and BNN), and the nonlinear SVR model tended to forecast slightly better than the linear SVR model. Among the six regions, the Prairies region displayed the highest forecast skills, and the Arctic region the second highest. The strongest nonlinearity was manifested over the Prairies and the weakest nonlinearity over the Arctic.
Natural laws of precipitation, great cycle, infiltration overland and groundwater runoff with a new formulas
Authors: Valjarevic A. Dj. , Valjarevic D. J.
Published: January 2011

Abstract. All the elements of water balance including precipitation are connected with soil. Some natural laws, which are a result of external (climate, relief) and internal (geological structure, thickness) natural factors, influence the leachate water to be transformed into surface outflow, infiltration, evaporation and subsurface runoff. M. I. Ljvovic has found dependencies between infiltration, evaporation and subsurface runoff. His method is a six component are. In this work, there has been connection established between infiltration in surface runoff and precipitation. This method for determining elements of water balance is a three component are and essentially is purely mathematics. On the graphics, values of the Ljvovic's coefficients are linked with the new one in the graphics, from the three component method. The new formula tries to explain characteristics of natural laws of precipitation infiltration overland and groundwater runoff, in another way. The method can be applied on permeable and impermeable terrains. The results obtanied mainly agree with the results obtained by the method of hydrograph analyzing.
Editorial 23(2)
Authors: Rivera Ricardo José
Published: January 2011

No tiene resumen.DOI: 10.5377/nexo.v23i2.214Nexo: Revista Científica Vol. 23, No. 02, pp.40/Nov 2010
Programación del riego de la papa en el "Valle del Yabú", Santa Clara, Cuba.
Authors: Pacheco Juan , Pérez A. , Job B.
Published: January 2011

El objetivo del presente trabajo, ejecutado durante dos cosechas 2009 y 2009-10 fue estudiar la programación del riego de la papa que se realiza en la Unidad Cooperativa No.2 del “Valle del Yabú” de Santa Clara y realizar correcciones para lograr el establecimiento de una programación de riego científicamente fundamentada. En la primera cosecha, se comprobó que el momento de aplicación del riego y el volumen de agua aportado no obedecían a criterios técnicos, sino que dependían de decisiones empíricas de las personas que se relacionaban con esta actividad y la programación del riego se caracterizaba por aplicar muy pequeñas láminas de agua que no lograban humedecer 20 cm de profundidad de suelo, de modo que, el riego obstaculizaba las labores fitosanitarias y culturales y dejaba el suelo con déficit hídrico. En ambas cosechas, se colocaron tensiómetros a 20 y 40 cm de profundidad del suelo, se tomaron muestras de humedad del mismo periódicamente y se efectuó un balance diario del agua en el suelo, con lo cual, se disminuyó el número de irrigaciones durante la segunda cosecha.Palabras claves: Balance hídrico, régimen de riego, pivote central.DOI: http://dx.doi.org/10.5377/nexo.v23i2.236Nexo: Revista Científica Vol. 23, No. 02, pp.41-46/Nov 2010
Control de la Congestión en el IEEE 802.17
Authors: Gámez E. , Álvarez F.
Published: January 2011

Este trabajo de investigación experimental aborda una solución al problema presentado en el núcleo de las redes Metropolitanas (MAN) por el algoritmo de equidad en modo Agresivo del protocolo 802.17, que sufre de una lenta convergencia para alcanzar el estado estable, lo que genera periodos de oscilaciones dentro de un dominio de congestión.Palabras Clave: MAN, RPR, Equidad, Congestión.DOI: http://dx.doi.org/10.5377/nexo.v23i2.237Nexo: Revista Científica Vol. 23, No. 02, pp.47-52/Nov 2010
Gestión del manejo integral de los desechos sólidos en el hospital Alemán Nicaragüense de Managua
Authors: Blandón K. , Castellanos Z.
Published: January 2011

La gestión de los desechos sólidos hospitalarios (DSH) del Hospital Alemán Nicaragüense (HAN) fue estudiada. El objetivo general propuesto fue un sistema de gestión de los desechos sólidos hospitalarios (comunes y peligrosos sin incluir los radiactivos), generados en el HAN. Se efectuó la cuantificación de los DSH durante el periodo de muestreo, elaboración de un listado de los DSH, se identificaron problemas existentes en el manejo actual de éstos desechos, y se elaboró una propuesta de plan de manejo seguro de los mismos, la que contempla: Plan integral de manejo de DSH que incluye todos los desechos (comunes y peligrosos, sin incluir los radiactivos), una propuesta de equipo adecuado para recolección y transporte interno y externo de DSH; propuesta de construcción de depósito para almacenamiento temporal interno de los DSH; y una propuesta de sistema de tratamiento y disposición final alternativo para los DSH/P generados en el HAN.Palabras Clave: desechos sólidos hospitalarios; gestión; manejoDOI: http://dx.doi.org/10.5377/nexo.v23i2.238Nexo: Revista Científica Vol. 23, No. 02, pp.53-61/Nov 2010
Sobre la inversión de los potenciales de Bessel-Riesz
Authors: Cerutti R.
Published: January 2011

En este trabajo se obtiene la inversión de un operador del tipo convolución usando técnicas de integrales hipersingulares. El operador de Bessel-Riesz de una función φ perteneciente a, Sel espacio de funciones de prueba de Schwartz, es definido por la convolución con las funciones generalizadas Wα(P±i0,m,n) expresables en términos de la función de Bessel de primera especie Jγ Wα(P±i0,m,n) es también una combinación lineal infinita del núcleo ultrahiperbólico de Riesz de diferentes ordenes. Este hecho nos permite invertir los potenciales de Bessel-Riesz de un modo análogo a lo hecho en el caso de los potenciales ultrahiperbólicos de Bessel (cf. [01]) y los potenciales causales de Riesz (cf. [2]).Palabras Claves: Potenciales de Riesz; Integrales Hipersingulares.DOI: http://dx.doi.org/10.5377/nexo.v23i2.239Nexo: Revista Científica Vol. 23, No. 02, pp.62-68/Nov 2010
Relaciones de recurrencia e identidades entre (ver formula en pdf) y sus derivadas
Authors: Aguirre M.
Published: January 2011

En este trabajo, se le da un sentido a la fórmula (ver formula en pdf) donde, (ver formula en pdf) Nuestra fórmula es una generalización de formulas que aparecen  en ([3]) y ([4]). En particular cuando m=1 y l=1 la formula es considerada por ejemplo, por  Bollini, Giambiagi y Tiommo para la teoría de regularización analítica en las ecuaciones clásicas de Yan-Mills  y sus aplicaciones para el potencial singulars (c.f. [5]).Palabras claves: Teoría de distribucionesDOI: http://dx.doi.org/10.5377/nexo.v23i2.240Nexo: Revista Científica Vol. 23, No. 02, pp.69-74/Nov 2010
Synaptic Plasticity in the Hippocampal Slice Preparation
Authors: Bortolotto Zuner A. , Amici Mascia , Anderson William W. , Isaac John T.R. , Collingridge Graham L.
Published: January 2011

Synaptic plasticity is the process by which the brain alters the strength of its synaptic connections, a fundamental function of the brain that enables individuals to learn from experience. The study of synaptic plasticity often involves the application of standard in vitro electrophysiological techniques to hippocampal slice preparations. This unit discusses many of the special considerations that are applicable for the optimal study of synaptic plasticity in this system. Most of these principles also apply to the study of synaptic plasticity in other brain slice preparations. Curr. Protoc. Neurosci. 54:6.13.1‐6.13.26. © 2011 by John Wiley & Sons, Inc.
Open‐Space Forced Swim Model of Depression for Mice
Authors: Stone Eric A. , Lin Yan
Published: January 2011

This protocol describes a simplified method for inducing a chronic depression‐like state in mice that is based on the repeated open‐space forced swim method originally developed for rats. The method consists of mice swimming daily in lukewarm water in rat tub cages, for 15  min/day for 4 days, and thereafter once per week. This procedure produces a progressive decrease in distance swum and a concomitant increase in immobility (floating) in ∼70% of the mice, both of which persist unaltered for weeks. The model has predictive, face, and construct validity and has a number of advantages over previous methods in that it utilizes very mild stress, is short in duration, and is easily standardized. Moreover, since it utilizes a greater swimming area than the traditional (Porsolt) method it can be used to study interactions of depressive behavior with behavioral flexibility and perseveration. Curr. Protoc. Neurosci. 54:9.36.1‐9.36.8. © 2011 by John Wiley & Sons, Inc.
Assessment of Beta Cell Viability
Authors: Jayaraman Sundararajan
Published: January 2011

This unit contains detailed protocols for the simultaneous identification of the human pancreatic β cells and determination of their viability by flow cytometry. The enumeration of β cells is based on the ability of the cell‐permeable form of the zinc‐selective dye, FluoZin‐3‐AM, to bind intracellular labile zinc stored at higher levels in these cells than any other types of cells in the body. Although staining of intracellular labile zinc by FluoZin‐3‐AM is dependent on the metabolic activity of β cells, co‐staining with a mitochondrial transmembrane potential indicator allows the accurate determination of viability. Simultaneous measurement of intracellular antioxidant thiols is also compatible with the detection of β cells containing metabolically active mitochondria. The method for assessing the mitochondrial functionality by flow cytometry described herein is simple to perform and sufficient to detect the viability of β cells in human islet preparations.Curr. Protoc. Cytom. 55:6.27.1‐6.27.16. © 2010 by John Wiley & Sons, Inc.
2,6‐Diisopropoxyphenyl(dicyclohexyl)phosphine: A New Ligand for Palladium‐Catalyzed Amination Reactions of Aryl Chlorides with Potassium Hydroxide as the Base
Authors: Lü Bo , Li Pengbin , Fu Chunling , Xue Liqin , Lin Zhenyang , Ma Shengming
Published: January 2011

A new, readily available monophosphine tetrafluoroborate salt [L2⋅HBF4] was developed for the palladium‐catalyzed amination reaction of aryl chlorides in moderate to high yields with the cheap and easily available potassium hydroxide as the base. The reaction enjoys a wide scope, lower reaction temperatures, shorter reaction times, high yields, and low catalyst loading when compared to some of same amination reactions reported in the literature. Based on a kinetic study, 31P NMR measurements, and DFT calculations, a mechanism involving a 1:1 Pd/L species is proposed.
One‐Pot Synthesis of Triazolothiadiazepine 1,1‐Dioxide Derivatives via Copper‐Catalyzed Tandem [3+2] Cycloaddition/N‐Arylation
Authors: Barange Deepak Kumar , Tu Yu‐Chen , Kavala Veerababurao , Kuo Chun‐Wei , Yao Ching‐Fa
Published: January 2011

A practical and efficient synthesis of triazolothiadiazepine‐1,1‐dioxide derivatives via copper‐catalyzed [3+2] cycloaddition, followed by N‐arylation is described. The method is also applicable to the synthesis of indoline‐ and thiophene‐fused triazolothiadiazepine 1,1‐dioxide derivatives.
Weight support distribution during quadrupedal walking in Ateles and Cebus
Authors: Larson Susan G. , Demes Brigitte
Published: January 2011

While it is well known that primate quadrupeds are distinctive in supporting more body weight on their hind limbs than their forelimbs, it has been unclear how this support asymmetry comes about. The simple explanation of a difference in body center of mass (COM) position is not supported by empirical data, leaving two less intuitive proposals. The first involves the position of the hands and feet relative to the COM, and has recently received support by Raichlen et al. (Am J Phys Anthropol 138 (2009) 395‐402) who document that chimpanzees walk with a relatively protracted hind limb, bringing their feet closer to the COM for greater hind limb weight support. The second posits the use of hip retractor muscles to actively shift weight off the forelimbs and onto the hind limbs, and has received recent support by Larson and Stern (Am J Phys Anthropol 138 (2009) 343‐355), who report higher levels of hip extensor activity in primates that bear more weight on their hind limbs. Since the study by Raichlen et al. (Am J Phys Anthropol 138 (2009) 395‐402) is based on a limited empirical dataset, we have undertaken a replicate study to document average limb posture and weight support distribution in two additional primate species: Ateles and Cebus. Using the equations presented by Raichlen etal. (Am J Phys Anthropol 138 (2009) 395‐402), predicted forelimb weight support based on limb posture was compared to observed values based on vertical impulses. In contrast to their findings, the limb posture model dramatically overestimated actual forelimb weight support in the monkeys, calling into question the general applicability of this model. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Preparation and properties of chitosan‐graft‐poly(methyl methacrylate) nanoparticles using potassium diperiodatocuprate (III) as an initiator
Authors: Liu Zhanjun , Zhao Guodong , Yu Jiugao , Zhang Jinqiu , Ma Xiaofei , Han Gang
Published: January 2011

Graft copolymer nanoparticles prepared from chitosan (CS) and methyl methacrylate (MMA) monomer were synthesized in aqueous solution by using potassium diperiodatocuprate [Cu(III)] as an initiator and characterized in terms of particle size, zeta potential, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, thermal stability, and X‐ray diffraction spectrometry. The results indicated that CS was covalently linked to poly(methyl methacrylate) (PMMA), and the resulting copolymers formed nanoparticles. These nanoparticles [prepared at 35°C, in a weight ratio of MMA/CS of 5 : 1 and with a Cu(III) concentration of 1.5 × 10−3 mol/L] were 54–350 nm in size, with a mean hydrodynamic diameter of 183 ± 3 nm and were highly uniform in particle‐size distribution, with a rather spherical shape and an obvious positive charge surface. The effect of reaction conditions such as Cu(III) concentration, reaction temperature, and the weight ratio of MMA/CS on the mean particle size was also investigated. Insulin‐loaded nanoparticles were prepared, and their maximal association efficiency was up to 85.41%. The experiment of release in vitro showed that the nanoparticles gave an initial burst release followed by a slowly sustained one. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The Action Sites of Propofol in the Normal Human Brain Revealed by Functional Magnetic Resonance Imaging
Authors: Zhang Hui , Wang Wei , Zhao Zhijing , Ge Yali , Zhang Jinsong , Yu Daihua , Chai Wei , Wu Shengxi , Xu Lixian
Published: January 2011

Activated clusters (red dots) in temporal lobe of normal human brain during propofolinduced anesthesia revealed by functional magnetic resonance imaging. See Zhang et al., on page 1985, in this issue.
Rhodium‐Catalyzed 1,4‐Addition of Lithium 2‐Furyltriolborates to Unsaturated Ketones and Esters for Enantioselective Synthesis of γ‐Oxo‐Carboxylic Acids By Oxidation of the Furyl Ring with Ozone
Authors: Yu Xiao‐Qiang , Shirai Tomohiko , Yamamoto Yasunori , Miyaura Norio
Published: January 2011

Rhodium‐catalyzed 1,4‐addition of lithium 5‐methyl‐2‐furyltriolborate ([ArB(OCH2)3CCH3]Li, Ar=5‐methyl‐2‐furyl) to unsaturated ketones to give β‐furyl ketones was followed by ozonolysis of the furyl ring for enantioselective synthesis of γ‐oxo‐carboxylic acids. [Rh(nbd)2]BF4 (nbd=2,5‐norbornadiene) chelated with 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (binap) or 2,3‐bis(diphenylphosphino)butane (chiraphos) gave high yields and high selectivities in a range of 91–99 % ee at 30 °C in a basic dioxane/water solution. The corresponding reaction of unsaturated esters, such as methyl crotonate, had strong resistance under analogous conditions, but the 1,4‐adduct was obtained in 70 % yield and with 94 % ee when more electron‐deficient phenyl crotonate was used as the substrate.