bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender differences in technology acceptance in selected South African companies: Implications for electronic learning
Authors: Chinyamurindi Willie T. , Louw Gert J.
Published: November 2010

Orientation: Technology enhanced training is becoming popular as a means for the training of soft skills, especially in work-related environments. Men and women who use this type of training encounter some challenges with regard to their usage.Research: The objective of this study was to investigate trainees’ acceptance of electronic coursework as an instruction and learning technique in various industries in the South African context.Motivation for the study: A persistent gender imbalance in the South African work-place has been noted to exist chiefly in the Science, Engineering and Technology (SET) sectors, areas that have an important bearing on South Africa’s global competitiveness. This study explores how gender imbalance manifests in terms of trainee acceptance of electronic coursework.Research design, approach and method: A cross-sectional survey design was used. A survey was conducted amongst 191 employees in the SET sector. The measuring instrument used was the Technology Acceptance Instrument (TAI) and included measures of Computer Self-Efficacy (CSE), Perceived Ease of Use (PEU), Perceived Usefulness (PU) and Behavioural Intention to Use (BI).Main findings: Women ratings of the TAI to use the electronic coursework were slightly higher than men’s ratings. Multiple regression analyses were also carried out to measure the variation in the level of influence with gender as a predictor variable. The results showed that compared to women, men had a lower salient effect of elements of the TAI, notably, CSE–PU; PU–BI and BI–PEU. However, compared to men, women had a higher salient effect in terms of the relationship between CSE–PU and PU–PEU.Practical implications: The implication of the results is that interventions that focus on the human resources development of employees using electronic coursework (namely, CSE, PEU, PU and BI) are worth considering as they influence the acceptance of the interventions.Contribution/value-add: The study contributes to existing knowledge about the conditions that precede employee acceptance of an electronic coursework intervention within the South African context. The study shows the important role dimensions of the Technology Acceptance Instrument (TAI).
Abdominal Computed Tomography Findings of Malaria Infection with Plasmodium vivax
Authors: Kim Eun Mi , Cho Hyeon Je , Cho Chong Rae , Kwak Yee Gyung , Kim Mi Young , Cho Yun Ku
Published: November 2010

Abdominal computed tomography (CT) findings of malaria are not well-known even though malaria is a serious infectious disease. To identify abdominal CT findings, we selected 34 of 405 patients who had a positive peripheral blood smear for Plasmodium vivax and had underwent abdominal CT as the malaria group. We also selected 80 patients who had fever and a negative peripheral blood smear as the control group and 120 healthy people as the normal group. We reviewed and analyzed their medical records and CT findings retrospectively. The mean spleen and liver length were significantly larger in the malaria group and the incidence of splenomegaly, splenic focal low attenuation, and spontaneous splenic rupture were much higher in the malaria group (P < 0.05). Although abdominal CT is not an indispensable tool for diagnosis, these CT findings will help in the diagnosis of malaria in patients with fever.
Using Giant African Pouched Rats to Detect Tuberculosis in Human Sputum Samples: 2009 Findings
Authors: Poling Alan , Weetjens Bart J. , Cox Christophe , Mgode Georgies , Jubitana Maureen , Kazwala Rudovic , Mfinanga Godfrey S. , Huis in ‘t Veld Diana
Published: November 2010

In 2009, giant African pouched rats trained to detect tuberculosis (TB) evaluated sputum samples from 10,523 patients whose sputum had previously been evaluated by smear microscopy. Microscopists found 13.3% of the patients to be TB-positive. Simulated second-line screening by the rats revealed 620 new TB-positive patients, increasing the case detection rate by 44%. These data suggest that the rats may be useful for TB detection in developing countries, although further research is needed.
Impact of the Integration of Water Treatment and Handwashing Incentives with Antenatal Services on Hygiene Practices of Pregnant Women in Malawi
Authors: Sheth Anandi N. , Russo Elizabeth T. , Menon Manoj , Wannemuehler Kathleen , Weinger Merri , Kudzala Amose C. , Tauzie Blessius , Masuku Humphreys D. , Msowoya Tapona E. , Quick Robert
Published: November 2010

Access to safe drinking water and improved hygiene are important for reducing morbidity and mortality from diarrhea. We surveyed 330 pregnant women who participated in an antenatal clinic-based intervention in Malawi that promoted water treatment and hygiene through distribution of water storage containers, sodium hypochlorite water treatment solution, soap, and educational messages. Program participants were more likely to know correct water treatment procedures (62% versus 27%, P < 0.0001), chlorinate drinking water (61% versus 1%, P < 0.0001), demonstrate correct handwashing practices (68% versus 22%, P < 0.0001), and purchase water treatment solution after free distribution (32% versus 1%, P < 0.0001). Among participants, 72% had at least three antenatal visits, 76% delivered in a health facility, and 54% had a postnatal check. This antenatal-clinic-based program is an effective new strategy for promoting water treatment and hygiene behaviors among pregnant women. Participants had high use of antenatal, delivery, and postnatal services, which could improve maternal and child health.
A Randomized, Double-Blind, Placebo-Controlled Study to Investigate the Safety, Tolerability, and Pharmacokinetics of Single Enantiomer (+)-Mefloquine Compared with Racemic Mefloquine in Healthy Persons
Authors: Tansley Robert , Lotharius Julie , Priestley Anthony , Bull Fiona , Duparc Stephan , Möhrle Jörg
Published: November 2010

Racemic mefloquine is a highly effective antimalarial whose clinical utility has been compromised by its association with neuropsychiatric and gastrointestinal side effects. It is hypothesized that the cause of the side effects may reside in the (−) enantiomer. We sought to compare the safety, tolerability and pharmacokinetic profile of (+)-mefloquine with racemic mefloquine in a randomized, ascending-dose, double-blind, active and placebo-controlled, parallel cohort study in healthy male and female adult volunteers. Although differing in its manifestations, both study drugs displayed a substantially worse tolerability profile compared with placebo. The systemic clearance was slower for (−)-mefloquine than (+)-mefloquine. Thus, (+)-mefloquine has a different safety and tolerability profile compared with racemic mefloquine but its global safety profile is not superior and replacement of the currently used antimalarial drug with (+)-mefloquine is not warranted.
Rickettsia in Synanthropic and Domestic Animals and Their Hosts from Two Areas of Low Endemicity for Brazilian Spotted Fever in the Eastern Region of Minas Gerais, Brazil
Authors: Milagres Bruno S. , Padilha Amanda F. , Barcelos Rafael M. , Gomes Gabriel G. , Montandon Carlos E. , Pena Dárlen C. H. , Nieri Bastos Fernanda A. , Silveira Iara , Pacheco Richard , Labruna Marcelo B. , Bouyer Donald H. , Freitas Renata N. , Walker David H. , Mafra Cláudio L. , Galvao Márcio A. M.
Published: November 2010

The aim of this study was to understand the current epidemiology of rickettsial diseases in two rickettsial-endemic regions in Brazil. In the municipalities of Pingo D'Agua and Santa Cruz do Escalvado, among serum samples obtained from horses and dogs, reactivity by immunofluorescent assay against spotted fever group rickettsiae was verified. In some serum samples from opossums (Didelphis aurita) captured in Santa Cruz do Escalvado, serologic response against rickettsiae was also verified. Polymerase chain reaction identified rickettsiae only in ticks and fleas obtained in Santa Cruz do Escalvado. Rickettsiae in samples had 100% sequence homology with Rickettsia felis. These results highlight the importance of marsupials in maintenance of the sylvatic cycle of rickettsial disease and potential integration with the domestic cycle. Our data also support the importance of horses and dogs as sentinels in monitoring circulation of rickettsiae in an urban area.
Different Allele Prevalence in the Dihydrofolate Reductase and Dihydropteroate Synthase Genes in Plasmodium vivax Populations from China
Authors: Miao Miao , Yang Zhaoqing , Cui Long , Ahlum Jessica , Huang Yaming , Cui Liwang
Published: November 2010

Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps). In this study, we used direct sequencing to survey pvdhfr and pvdhps mutations in 122 clinical P. vivax isolates from a central and a southern province of China. For pvdhfr, 36.9% were wild-type, whereas mutations were detected at four codons (57, 58, 61, and 117). The S117N/T mutation was the most prevalent (48.4%), followed by the T61M mutation (18.9%). Six pvdhfr mutant alleles were found, ranging from 37.7% to 0.8%. The dramatically different pvdhfr allele frequencies between the two P. vivax populations might be caused by different drug histories or intrinsic difference between temperate and subtropical strains. In contrast, except polymorphisms within a repeat region, no resistance-conferring mutations were detected in pvdhps. Our result suggests that P. vivax populations in China may be relatively susceptible to sulfadoxine-pyrimethamine.
Effect of Repeated Treatment of Pregnant Women with Sulfadoxine-Pyrimethamine and Azithromycin on Preterm Delivery in Malawi: A Randomized Controlled Trial
Authors: Luntamo Mari , Kulmala Teija , Mbewe Bernard , Cheung Yin Bun , Maleta Kenneth , Ashorn Per
Published: November 2010

Preterm delivery, which is associated with infections during pregnancy, is common in sub-Saharan Africa. We enrolled 1,320 pregnant women into a randomized, controlled trial in Malawi to study whether preterm delivery and low birth weight (LBW) incidence can be reduced by intermittent preventive treatment of maternal malaria and reproductive tract infections. The participants received either sulfadoxine-pyrimethamine (SP) twice (controls), monthly SP, or monthly SP and two doses of azithromycin (AZI-SP). The incidence of preterm delivery was 17.9% in controls, 15.4% in the monthly SP group (P = 0.32), and 11.8% in AZI-SP group (risk ratio = 0.66, P = 0.01). Compared with controls, those in AZI-SP group had a risk ratio of 0.61 (P = 0.02) for LBW. Incidence of serious adverse events was low in all groups. In conclusion, the incidence of preterm delivery and LBW can in some conditions be reduced by treating pregnant women with monthly SP and two azithromycin doses.
Tuberculosis Pericarditis with Cardiac Tamponade: Management in the Resource-Limited Setting
Authors: Heller Tom , Lessells Richard J. , Wallrauch Claudia , Brunetti Enrico
Published: November 2010

We report a case of human immunodeficiency virus–associated pericardial tuberculosis complicated by cardiac tamponade. Emergency management and subsequent therapeutic interventions are described and then discussed with particular focus on resource-limited settings. The paucity of evidence to support clinical decisions is emphasized and the need for well designed diagnostic and therapeutic studies is highlighted.
A Phase III, Randomized, Non-Inferiority Trial to Assess the Efficacy and Safety of Dihydroartemisinin-Piperaquine in Comparison with Artesunate-Mefloquine in Patients with Uncomplicated Plasmodium falciparum Malaria in Southern Laos
Authors: Mayxay Mayfong , Keomany Sommay , Khanthavong Maniphone , Souvannasing Phoutthalavanh , Stepniewska Kasia , Khomthilath Tiengthong , Keola Siamphay , Pongvongsa Tiengkham , Phompida Samlane , Ubben David , Valecha Neena , White Nicholas J. , Newton Paul N.
Published: November 2010

We conducted an open, randomized clinical trial of oral dihydroartemisinin-piperaquine (DP) versus artesunate-mefloquine (AM) in 300 patients in Laos with uncomplicated Plasmodium falciparum malaria as part of a multicentre study in Asia. Survival analysis and adjustment for re-infection showed that the 63-day cure rates (95% confidence interval [CI]) were 100% for AM and 99.5% (96.4–99.8%) for DP. The 63-day cure rates per protocol were 99% (97 of 98) for AM and 99.5% (196 of 197) for DP (P = 0.55). The difference (AM minus DP) in cure rates (95% CI) was −0.5% (−5.1 to 2.0%), which is within the 5% non-inferiority margin. The median fever and parasite clearance times were also similar for AM and DP. The proportion of patients with at least one recorded potential adverse event was significantly higher in the AM group (38 of 87, 44%) than in the DP group (57 of 182, 31%) (relative risk = 0.6, 95% CI = 0.4–0.9; P = 0.04). Dihydroartemisinin-piperaquine is not inferior to AM in the treatment of uncomplicated P. falciparum malaria in Laos and is associated with fewer adverse effects. The results of this study were similar to those of the larger multicentre study.
Seroprevalence Survey of Chikungunya Virus in Bagan Panchor, Malaysia
Authors: Ayu Said Mas , Lai Li Rong , Chan Yoke Fun , Hatim Ahmad , Hairi Noran Naqiah , Ayob Asiah , Sam I-Ching
Published: November 2010

In 2006, an outbreak of Chikungunya virus (CHIKV) of the Asian genotype affected over 200 people in Bagan Panchor village in Malaysia. One year later, a post-outbreak survey was performed to determine attack rate, asymptomatic rate, and post-infection sequelae. Findings were compared with recent CHIKV outbreaks of the Central/East African genotype. A total of 180 residents were interviewed for acute symptoms and post-infection physical quality of life and depressive symptoms. Sera from 72 residents were tested for CHIKV neutralizing antibodies. The estimated attack rate was 55.6%, and 17.5% of infected residents were asymptomatic. Arthralgia was reported up to 3 months after infection, but there were no reports of long-term functional dependence or depression. Symptomatic and seropositive residents were significantly more likely to live in the area with the most dense housing and commercial activities. CHIKV had a high attack rate and considerable clinical impact during the Bagan Panchor outbreak.
Isolation and Characterization of Sylvatic Mosquito-Borne Viruses in Trinidad: Enzootic Transmission and a New Potential Vector of Mucambo Virus
Authors: Auguste Albert J. , Adams A. Paige , Arrigo Nicole C. , Martinez Raymond , Travassos da Rosa Amelia P. A. , Adesiyun Abiodun A. , Chadee Dave D. , Tesh Robert B. , Carrington Christine V. F. , Weaver Scott C.
Published: November 2010

Mosquito surveillance was carried out in three forested regions of Trinidad during July 2007–March 2009. A total of 185,397 mosquitoes representing at least 46 species was collected, divided into pools of 1–50 mosquitoes according to species and sex, and screened for arboviruses using cytopathic effect assays on Vero cell monolayers. Eighty-five viruses were isolated, including members of the genera Alphavirus (Mucambo virus; MUCV) and Orthobunyavirus (Caraparu, Oriboca, Bimiti, and Wyeomyia viruses). Species of the Culex subgenus Melanoconion accounted for 56% of the total number of mosquitoes collected and 97% of the viruses isolated; Cx. (Mel.) portesi accounted for 92% of virus isolations. Our results also implicate for the first time Aedes (Ochlerotatus) hortator as a potential vector of MUCV. Phylogenetic analyses of 43 MUCV strains suggest population subdivision within Trinidad, consistent with the hypothesis of enzootic maintenance in localized rodent populations.
Diagnostic and Treatment Difficulties of Pyelonephritis in Pregnancy in Resource-Limited Settings
Authors: McGready Rose , Wuthiekanun Vanaporn , Ashley Elizabeth A. , Tan Saw Oo , Pimanpanarak Mupawjay , Viladpai-nguen Samuel Jacher , Jesadapanpong Wilarat , Blacksell Stuart D. , Proux Stephane , Day Nicholas P. , Singhasivanon Pratap , White Nicholas J. , Nosten François , Peacock Sharon J.
Published: November 2010

Limited microbiology services impede adequate diagnosis and treatment of common infections such as pyelonephritis in resource-limited settings. Febrile pregnant women attending antenatal clinics at Shoklo Malaria Research Unit were offered urine dipstick, sediment microscopy, urine culture, and a 5-mL blood culture. The incidence of pyelonephritis was 11/1,000 deliveries (N = 53 in 4,819 pregnancies) between January 7, 2004 and May 17, 2006. Pyelonephritis accounted for 20.2% (41/203) of fever cases in pregnancy. Escherichia coli was the most commonly isolated pathogen: 87.5% (28/32) of organisms cultured. Susceptibility of E. coli to ampicillin (14%), cotrimoxazole (21%), and amoxicillin-clavulanic acid (48%) was very low. E. coli was susceptible to ceftriaxone and ciprofloxacin. The rate of extended spectrum β-lactamase (4.2%; 95% confidence interval = 0.7–19.5) was low. The rate and causes of pyelonephritis in pregnant refugee and migrant women were comparable with those described in developed countries. Diagnostic innovation in microbiology that permits affordable access is a high priority for resource-poor settings.
Hospital Surveillance of Childhood Bacterial Meningitis in Senegal and the Introduction of Haemophilus influenzae Type b Conjugate Vaccine
Authors: Ba Osseynou , Fleming Jessica A. , Dieye Yakou , wa Mutombo Boniface Mutombo , Ba Mamadou , Cisse Moussa Fafa , Diallo Aissatou Gaye , Sow Iyane , Slack Mary P. E. , Faye Pape Coumba , Ba Mady , Diallo Ndiouga , Weiss Noel S.
Published: November 2010

Bacterial meningitis is an important cause of morbidity and mortality in children living in low-resource settings. Pediatric bacterial meningitis cases < 5 years of age were identified through a regional hospital surveillance system for 3 years after introduction of routine immunization with Haemophilus influenzae type b (Hib) conjugate vaccine in Senegal in July 2005. Cases from the national pediatric hospital were also tracked from 2002 to 2008. The regional surveillance system recorded 1,711 suspected pediatric bacterial meningitis cases. Of 214 laboratory-confirmed cases, 108 (50%) were caused by Streptococcus pneumoniae, 42 (20%) to Hib, and 13 (6%) to Neisseria meningitidis. There was a 98% reduction in the number of hospitalized Hib meningitis cases from Dakar Region in 2008 compared with 2002. The surveillance system provides important information to the Ministry of Health as they consider self-funding Hib vaccine and introducing pneumococcal vaccine.
Vector-Host Interactions Governing Epidemiology of West Nile Virus in Southern California
Authors: Molaei Goudarz , Cummings Robert F. , Su Tianyun , Armstrong Philip M. , Williams Greg A. , Cheng Min-Lee , Webb James P. , Andreadis Theodore G.
Published: November 2010

Southern California remains an important focus of West Nile virus (WNV) activity, with persistently elevated incidence after invasion by the virus in 2003 and subsequent amplification to epidemic levels in 2004. Eco-epidemiological studies of vectors-hosts-pathogen interactions are of paramount importance for better understanding of the transmission dynamics of WNV and other emerging mosquito-borne arboviruses. We investigated vector-host interactions and host-feeding patterns of 531 blood-engorged mosquitoes in four competent mosquito vectors by using a polymerase chain reaction (PCR) method targeting mitochondrial DNA to identify vertebrate hosts of blood-fed mosquitoes. Diagnostic testing by cell culture, real-time reverse transcriptase-PCR, and immunoassays were used to examine WNV infection in blood-fed mosquitoes, mosquito pools, dead birds, and mammals. Prevalence of WNV antibodies among wild birds was estimated by using a blocking enzyme-linked immunosorbent assay. Analyses of engorged Culex quinquefasciatus revealed that this mosquito species acquired 88.4% of the blood meals from avian and 11.6% from mammalian hosts, including humans. Similarly, Culex tarsalis fed 82% on birds and 18% on mammals. Culex erythrothorax fed on both birds (59%) and mammals (41%). In contrast, Culex stigmatosoma acquired all blood meals from avian hosts. House finches and a few other mostly passeriform birds served as the main hosts for the blood-seeking mosquitoes. Evidence of WNV infection was detected in mosquito pools, wild birds, dead birds, and mammals, including human fatalities during the study period. Our results emphasize the important role of house finches and several other passeriform birds in the maintenance and amplification of WNV in southern California, with Cx. quinquefasciatus acting as both the principal enzootic and “bridge vector” responsible for the spillover of WNV to humans. Other mosquito species, such as Cx. tarsalis and Cx. stigmatosoma, are important but less widely distributed, and also contribute to spatial and temporal transmission of WNV in southern California.
Decreased Prevalence of Lymphatic Filariasis Among Subjects with Type-1 Diabetes
Authors: Aravindhan Vivekanandhan , Mohan Vishwanathan , Surendar Jayagopi , Rao Maradana Muralidhara , Ranjani Harish , Kumaraswami V. , Nutman Thomas B. , Babu Subash
Published: November 2010

Several animal studies have shown a protective effect of helminth infections against type-1 diabetes mellitus (T1DM). However, epidemiologic studies demonstrating this protective relationship with T1DM are largely lacking, although an inverse correlation between the prevalence of lymphatic filariasis (LF) and prevalence of allergies and autoimmunity has been shown. A cross-sectional study was undertaken in southern India to assess the baseline prevalence of seropositivity of LF among persons with T1DM (n = 200) and normal glucose tolerant (NGT) persons (n = 562). The prevalence of LF was 0% among persons with T1DM and 2.6% among NGT persons (P = 0.026). The percentage of persons who were positive for filarial antigen-specific IgG4 (but not antigen-specific IgG) was also significantly lower in persons with T1DM (2%) compared with NGT persons (28%) (P < 0.001). Thus, there appears to be a striking inverse relationship between the prevalence of LF and T1DM in southern India.
In Vitro Generation of Plasmodium falciparum Ookinetes
Authors: Bounkeua Viengngeun , Li Fengwu , Vinetz Joseph M.
Published: November 2010

Plasmodium transmission from the human host to the mosquito depends on the ability of gametocytes to differentiate into ookinetes, the invasive form of the parasite that invades and establishes infection in the mosquito midgut. The biology of P. falciparum ookinetes is poorly understood, because sufficient quantities of this stage of this parasite species have not been obtained for detailed study. This report details methods to optimize production of P. falciparum sexual stage parasites, including ookinetes. Flow cytometric sorting was used to separate diploid/tetraploid zygotes and ookinetes from haploid gametetocytes and unfertilized gametes based on DNA content. Consistent production of 106–107 P. falciparum ookinetes per 10 mL culture was observed, with ookinete transformation present in 10–40% of all parasite forms. Transmission electron micrographs of cultured parasites confirmed ookinete development.
On the roles of sulphuric acid and low-volatility organic vapours in the initial steps of atmospheric new particle formation
Authors: Paasonen P. , Nieminen T. , Asmi E. , Manninen H. E. , Petäjä T. , Plass-Dülmer C. , Flentje H. , Birmili W. , Wiedensohler A. , Hõrrak U. , Metzger A. , Hamed A. , Laaksonen A. , Facchini M. C. , Kerminen V.-M. , Kulmala M.
Published: November 2010

Abstract. Sulphuric acid and organic vapours have been identified as the key components in the ubiquitous secondary new particle formation in the atmosphere. In order to assess their relative contribution and spatial variability, we analysed altogether 36 new particle formation events observed at four European measurement sites during EUCAARI campaigns in 2007–2009. We tested models of several different nucleation mechanisms coupling the formation rate of neutral particles (J) with the concentration of sulphuric acid ([H2SO4]) or low-volatility organic vapours ([org]) condensing on sub-4 nm particles, or with a combination of both concentrations. Furthermore, we determined the related nucleation coefficients connecting the neutral nucleation rate J with the vapour concentrations in each mechanism. The main goal of the study was to identify the mechanism of new particle formation and subsequent growth that minimizes the difference between the modelled and measured nucleation rates. At three out of four measurement sites – Hyytiälä (Finland), Melpitz (Germany) and San Pietro Capofiume (Italy) – the nucleation rate was closely connected to squared sulphuric acid concentration, whereas in Hohenpeissenberg (Germany) the low-volatility organic vapours were observed to be dominant. However, the nucleation rate at the sulphuric acid dominant sites could not be described with sulphuric acid concentration and a single value of the nucleation coefficient, as K in J=K [H2SO4]2, but the median coefficients for different sites varied over an order of magnitude. This inter-site variation was substantially smaller when the heteromolecular homogenous nucleation between H2SO4 and organic vapours was assumed to take place in addition to homogenous nucleation of H2SO4 alone, i.e., J=KSA1[H2SO4]2+KSA2[H2SO4][org]. By adding in this equation a term describing homomolecular organic vapour nucleation, Ks3[org]2, equally good results were achieved. In general, our results suggest that organic vapours do play a role, not only in the condensational growth of the particles, but also in the nucleation process, with a site-specific degree.
Global modeling of organic aerosol: the importance of reactive nitrogen (NOx and NO3)
Authors: Pye H. O. T. , Chan A. W. H. , Barkley M. P. , Seinfeld J. H.
Published: November 2010

Abstract. Reactive nitrogen compounds, specifically NOx and NO3, likely influence global organic aerosol levels. To assess these interactions, GEOS-Chem, a chemical transport model, is updated to include improved biogenic emissions (following MEGAN v2.1/2.04), a new organic aerosol tracer lumping scheme, aerosol from nitrate radical (NO3) oxidation of isoprene, and NOx-dependent monoterpene and sesquiterpene aerosol yields. As a result of significant nighttime terpene emissions, fast reaction of monoterpenes with the nitrate radical, and relatively high aerosol yields from NO3 oxidation, biogenic hydrocarbon-NO3 reactions are expected to be a major contributor to surface level aerosol concentrations in anthropogenically influenced areas such as the United States. By including aerosol from nitrate radical oxidation in GEOS-Chem, terpene (monoterpene + sesquiterpene) aerosol approximately doubles and isoprene aerosol is enhanced by 30 to 40% in the Southeast United States. In terms of the global budget of organic aerosol, however, aerosol from nitrate radical oxidation is somewhat minor (slightly more than 3 Tg/yr) due to the relatively high volatility of organic-NO3 oxidation products in the yield parameterization. Globally, 69 to 88 Tg/yr of organic aerosol is predicted to be produced annually, of which 14–15 Tg/yr is from oxidation of monoterpenes and sesquiterpenes and 8–9 Tg/yr from isoprene.
Multi sensor reanalysis of total ozone
Authors: van der A R. J. , Allaart M. A. F. , Eskes H. J.
Published: November 2010

Abstract. A single coherent total ozone dataset, called the Multi Sensor Reanalysis (MSR), has been created from all available ozone column data measured by polar orbiting satellites in the near-ultraviolet Huggins band in the last thirty years. Fourteen total ozone satellite retrieval datasets from the instruments TOMS (on the satellites Nimbus-7 and Earth Probe), SBUV (Nimbus-7, NOAA-9, NOAA-11 and NOAA-16), GOME (ERS-2), SCIAMACHY (Envisat), OMI (EOS-Aura), and GOME-2 (Metop-A) have been used in the MSR. As first step a bias correction scheme is applied to all satellite observations, based on independent ground-based total ozone data from the World Ozone and Ultraviolet Data Center. The correction is a function of solar zenith angle, viewing angle, time (trend), and effective ozone temperature. As second step data assimilation was applied to create a global dataset of total ozone analyses. The data assimilation method is a sub-optimal implementation of the Kalman filter technique, and is based on a chemical transport model driven by ECMWF meteorological fields. The chemical transport model provides a detailed description of (stratospheric) transport and uses parameterisations for gas-phase and ozone hole chemistry. The MSR dataset results from a 30-year data assimilation run with the 14 corrected satellite datasets as input, and is available on a grid of 1× 1 1/2° with a sample frequency of 6 h for the complete time period (1978–2008). The Observation-minus-Analysis (OmA) statistics show that the bias of the MSR analyses is less than 1% with an RMS standard deviation of about 2% as compared to the corrected satellite observations used.
Spectrally-invariant behavior of zenith radiance around cloud edges simulated by radiative transfer
Authors: Chiu J. C. , Marshak A. , Knyazikhin Y. , Wiscombe W. J.
Published: November 2010

Abstract. In a previous paper, we discovered a surprising spectrally-invariant relationship in shortwave spectrometer observations taken by the Atmospheric Radiation Measurement (ARM) program. The relationship suggests that the shortwave spectrum near cloud edges can be determined by a linear combination of zenith radiance spectra of the cloudy and clear regions. Here, using radiative transfer simulations, we study the sensitivity of this relationship to the properties of aerosols and clouds, to the underlying surface type, and to the finite field-of-view (FOV) of the spectrometer. Overall, the relationship is mostly sensitive to cloud properties and has little sensitivity to other factors. At visible wavelengths, the relationship primarily depends on cloud optical depth regardless of cloud phase function, thermodynamic phase and drop size. At water-absorbing wavelengths, the slope of the relationship depends primarily on cloud optical depth; the intercept, by contrast, depends primarily on cloud absorbing and scattering properties, suggesting a new retrieval method for cloud drop effective radius. These results suggest that the spectrally-invariant relationship can be used to infer cloud properties near cloud edges even with insufficient or no knowledge about spectral surface albedo and aerosol properties.
Quality or decomposer efficiency – which is most important in the temperature response of litter decomposition? A modelling study using the GLUE methodology
Authors: Wetterstedt J. Å. M. , Ågren G. I.
Published: November 2010

Abstract. Effects of temperature history on litter decomposition were evaluated using the GLUE modelling framework together with the Q-model calibrated to a needle litter incubation experiment. The needle litter incubation was a full factorial design with initial and final temperatures 5, 15 and 25 °C. Samples were moved from the initial to the final temperature when approximately 12% of the initial carbon had been respired. We used four variations of the Q-model: one or two initial litter quality values and fixed or temperature-dependent decomposer efficiency. The model was calibrated to the constant temperature data subset. Evaluation against temperature shift subsets gave good results, except just after the change in temperature where the model predicted a smaller response than observed. Using one or two initial litter quality values and fixed decomposer efficiency had little effect on final litter quality and respiration at the final incubation temperature. Allowing decomposer efficiency to vary with temperature showed that decomposer efficiency should decrease between 5 to 15 °C but with no change between 15 and 25 °C. A flexible decomposer efficiency resulted also in substantial differences in litter quality at the end of the initial incubation in response to incubation temperature. The results suggests that it is important to consider other factors than the variation in temperature sensitivity with quality when evaluating effects of temperature changes on soil organic matter stability.
An inversion method based on multi-angular approaches for estimating bare soil surface parameters from RADARSAT-1
Authors: Sahebi M. R. , Angles J.
Published: November 2010

Abstract. The radar signal recorded by earth observation (EO) satellites is sensitive to soil moisture and surface roughness, which both influence the onset of runoff. This paper focuses on inversion of these parameters using a multi-angular approach based on RADARSAT-1 data with incidence angles of 35° and 47° (in mode S3 and S7). This inversion was performed with three backscatter models: Geometrical Optics Model (GOM), Oh Model (OM), and Modified Dubois Model (MDM), which were compared to obtain the best configuration. Mean absolute errors of 1.23, 1.12, and 2.08 cm for roughness expressed in rms height and for dielectric constant, mean absolute errors of 2.46 – equal to 3.88 (m3 m−3) in volumetric soil moisture, – 4.95 – equal to 8.72 (m3 m−3) in volumetric soil moisture – and 3.31 – equal to 6.03 (m3 m−3) in volumetric soil moisture – were obtained for the MDM, GOM, and OM simulation, respectively. These results indicate that the MDM provided the most accurate data with minimum errors. Therefore, the latter inversion algorithm was applied to images, and the final results are presented in two different maps showing pixel and homogeneous zones for surface roughness and soil moisture.
Correction of upstream flow and hydraulic state with data assimilation in the context of flood forecasting
Authors: Ricci S. , Piacentini A. , Thual O. , Le Pape E. , Jonville G.
Published: November 2010

Abstract. The present study describes the assimilation of river water level observations and the resulting improvement of the river flood forecast. The BLUE algorithm was built on top of the one-dimensional hydraulics model MASCARET. The assimilation algorithm folds in two steps: the first one is based on the assumption that the upstream flow can be adjusted using a three-parameter correction, the second one consists in directly correcting the hydraulic state. This procedure is applied on a four-day sliding window over the whole flood event. The background error covariances for water level and discharge are represented with asymmetric correlation functions where the upstream correlation length is bigger than the downstream correlation length. This approach is motivated by the implementation of a Kalman Filter algorithm on top of an advection-diffusion toy model. The assimilation study with MASCARET is carried out on the Adour and the Marne Vallage (France) catchments. The correction of the upstream flow as well as the control of the hydraulic state along the flood event leads to a significant improvement of the water level and discharge in analysis and forecast modes.
Investigating annual and monthly trends in precipitation structure: an overview across Portugal
Authors: de Lima M. I. P. , Carvalho S. C. P. , de Lima J. L. M. P.
Published: November 2010

Abstract. This work investigates recent changes in precipitation patterns manifested in long annual and monthly precipitation time series recorded in Portugal. The dataset comprises records from 14 meteorological stations scattered over mainland Portugal and the Portuguese North Atlantic Islands of Madeira and Azores; some of the time series date back to the 19th century. The data were tested for trends using the Mann-Kendall non-parametric test and Sen's non-parametric method, searching both for full monotonic trends over the record period and for partial trends. Results provide no evidence for rejecting the null hypothesis of no trend in annual precipitation, when a monotonic linear model was used. Nevertheless, the analyses of 50 years' moving averages showed an increase over time, in the recent past, for many of the series in mainland Portugal and the Islands. For the longest time series this behaviour was preceded by a decrease over time. The analyses of partial trends in the time series suggested a sequence of alternately decreasing and increasing trends in annual and monthly precipitation, which are sometimes statistically significant. The trend changing points were identified.
Trajectories of aggression, delinquency, and substance use across middle school among urban, minority adolescents
Authors: Lynne‐Landsman Sarah D. , Graber Julia A. , Nichols Tracy R. , Botvin Gilbert J.
Published: November 2010

This study evaluated bidirectional associations between substance use, aggression, and delinquency across sixth, seventh, and eighth grades using data available from a large study of urban minority youth (n = 2,931). Group‐based trajectory analysis revealed trajectories of aggression, delinquency, and substance use which support the existence of both adolescent‐limited and life‐course persistent offenders. In addition, a pattern of decreasing aggression was observed during middle school. Clear temporal associations were observed between developmental changes in aggression, delinquency, and substance use. Notably, the decreasing aggression trajectory was as likely to be associated with high trajectories of substance initiation as was the high aggression trajectory. Furthermore, trajectories of delinquency were differentially associated with future substance use; however, substance use trajectories did not predict trajectories of delinquency. There were few gender differences in the developmental progression of these problem behaviors during middle school with only two exceptions, males were more likely to follow a trajectory of decreasing aggression and a trajectory of high stable delinquency. Evaluations of ethnic/racial differences in the trajectory group membership also revealed few differences. The results of this study provide important information regarding interconnections between developmental changes in problem behavior that occur during the middle school years, highlighting groups that may be missed via traditional analytic approaches that predict mean changes. Aggr. Behav. 37:161–176, 2011. © 2010 Wiley‐Liss, Inc.
Population‐based estimates of common comorbidities and cardiovascular disease in ankylosing spondylitis
Authors: Bremander Ann , Petersson Ingemar F. , Bergman Stefan , Englund Martin
Published: November 2010

Objective

To study the rate of common comorbidities and cardiovascular disease in patients with ankylosing spondylitis (AS) compared with the general population seeking health care.

Methods

This cohort study included 935 subjects (67% men) ages ≥20 years diagnosed with AS and the adult background population in Southern Sweden. During 2004 to 2007 we recorded the occurrence of physicians' diagnostic codes for a select number of comorbidities commonly associated with AS and cardiovascular disease and risk factors. We obtained standardized morbidity‐rate ratios (SMRs) by dividing the observed morbidity rate in AS patients by the expected rate based on the corresponding rate of the disease in the general population of the county seeking health care.

Results

The highest SMRs were found for uveitis (34.35, 95% confidence interval [95% CI] 28.55–40.98) and inflammatory bowel disease (9.28, 95% CI 7.07–11.97). Also, we found increased SMRs for ischemic heart diseases (2.20, 95% CI 1.77–2.70), hypertension (1.98, 95% CI 1.72–2.28), and diabetes mellitus (1.41, 95% CI 1.10–1.78). Furthermore, the SMRs for psoriasis, osteoporosis, and atrioventricular blocks were also statistically significantly elevated.

Conclusion

Inflammatory diseases affecting the eye and the digestive system were the most notable comorbidities in AS patients, but the rate for cardiovascular disease was also high. Using comprehensive longitudinal population‐based register data is a promising tool to evaluate the excess consultation rate and total burden of rheumatic disease on patients and society.
V2O5 Nanowires with an Intrinsic Peroxidase‐Like Activity
Authors: André Rute , Natálio Filipe , Humanes Madalena , Leppin Jana , Heinze Katja , Wever Ron , Schröder H.‐C. , Müller Werner E. G. , Tremel Wolfgang
Published: November 2010

V2O5 nanowires exhibit an intrinsic catalytic activity towards classical peroxidase substrates such as 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) and 3,3,5,5,‐tetramethylbenzdine (TMB) in the presence of H2O2. These V2O5 nanowires show an optimum reactivity at a pH of 4.0 and the catalytic activity is dependent on the concentration. The Michaelis‐Menten kinetics of the ABTS oxidation over these nanowires reveals a behavior similar to that of their natural vanadium‐dependent haloperoxidase (V‐HPO) counterparts. The V2O5 nanowires mediate the oxidation of ABTS in the presence of H2O2 with a turnover frequency (kcat) of 2.5 × 103 s−1. The KM values of the V2O5 nanowires for ABTS oxidation (0.4 μM) and for H2O2 (2.9 μM) at a pH of 4.0 are significantly smaller than those reported for horseradish peroxidases (HRP) and V‐HPO indicating a higher affinity of the substrates for the V2O5 nanowire surface. Based on the kinetic parameters and similarity with vanadium‐based complexes a mechanism is proposed where an intermediate metastable peroxo complex is formed as the first catalytic step. The nanostructured vanadium‐based material can be re‐used up to 10 times and retains its catalytic activity in a wide range of organic solvents (up to 90%) making it a promising mimic of peroxidase catalysts.
White‐Light Emitting Diode Array of p+‐Si/Aligned n‐SnO2 Nanowires Heterojunctions
Authors: Min Kyung Whon , Kim Yong Kwan , Shin Gunchul , Jang Seunghun , Han Moonsup , Huh Junghwan , Kim Gyu Tae , Ha Jeong Sook
Published: November 2010

We report on the fabrication and optoelectronic properties of p‐n heterojunction arrays of p+‐type Si and aligned n‐type SnO2 nanowires with high rectification ratios of >104 at ±15 V. The electrical stability of the p‐n heterojunction devices was improved by coating the junction with poly(methylmethacrylate) to minimize the degradation of the interface layer at the junction. As a photodiode an enhanced UV photosensitivity higher than 102 was recorded under reverse bias. Using a large forward bias in the light‐emitting diode mode white light was emitted from the large‐scale heterojunction devices with at least three broad peaks in the visible range, which can be attributed to the interband transitions of the injected electrons or holes mediated by an interfacial SiO2 layer with a contribution of trap‐level energies. These results indicate the high potential of Si/SnO2 nanowires heterojunctions as optoelectronic devices with proper tuning of the recombination center at the junctions.
A New Prototype Two‐Phase (TiNi)–(β‐W) SMA System with Tailorable Thermal Hysteresis
Authors: Buenconsejo Pio John S. , Zarnetta Robert , König Dennis , Savan Alan , Thienhaus Sigurd , Ludwig Alfred
Published: November 2010

The Ti–Ni–W two‐phase shape memory alloy (SMA) thin film system is presented as a prototype for new SMAs with tailorable thermal transformation hysteresis (ΔT). The concept is to combine the SMA TiNi with almost insoluble W to create the two‐phase system (TiNi)–(β‐W). This system behaves like a pseudobinary TiNi system. Phase transformation behavior for compositions above the solubility limit of W in TiNi exhibit a B2–R phase transformation with characteristically small ΔT. Moreover, ΔT is dependent on the amount of W and it can be tailored to zero and even negative. This phenomenon is rationalized as being due to the mechanical interaction between the phases B2‐TiNi and β‐W. The presented results are very promising for the development of high‐speed Ti–Ni‐based SMA actuators.
Male–immature relationships in multi‐male groups of mountain gorillas (Gorilla beringei beringei)
Authors: Rosenbaum S. , Silk J.B. , Stoinski T.S.
Published: November 2010

We examined the pattern and possible functions of social interactions between adult males and immatures in three free‐ranging, multi‐male groups of mountain gorillas (Gorilla beringei beringei). Previous studies conducted during the 1970s when groups contained one to three adult males concluded that male–immature relationships were likely to be a form of low‐cost paternal investment [Stewart, Mountain gorillas: three decades of research at Karisoke. Cambridge, UK: Cambridge University Press, 2001]. We evaluated whether this hypothesis still held in groups containing six to nine adult males, or if male–immature relationships might serve other functions (e.g. mating effort, kin selection, or alliance building). Overall, we found that immatures spent the most time near, and interacted most with, the alpha silverback. These behaviors peaked during the period when infants were still quite vulnerable but increasing their independence from their mothers. Such findings suggest that parenting effort remains the primary function of male–immature relationships; however, there is some evidence for the mating effort hypothesis as well. Am. J. Primatol. 73:356–365, 2011. © 2010 Wiley‐Liss, Inc.
Relationship between droplet size and fluid flow characteristics in miniemulsion polymerization of methyl methacrylate
Authors: Farzi Gholamali , Mortezaei Mehrzad , Badiei Alireza
Published: November 2010

Static mixer (SM) can be applied for emulsification, but the fundamental understanding of the nature of fluid flow and mixing in static mixers, is however poor. Droplet size is a very important parameter in miniemulsion systems and affects strongly the mechanism of particle formation in polymerization reactions. In this study, static mixer was used as homogenization device for emulsification of methyl methacrylate (MMA). Re number (Re) was obtained for SM inserted tube in different flow rates. It was demonstrated the nature of fluid flow was turbulent under our experimental conditions. The relationship between droplet size—the most important variable in our study—and Weber number (We) was investigated. The results showed that the ratio of the droplet size to the pipe diameter was fit as an exponential function with an order of −0.35. The polymerization of created droplets under certain We values by SM showed that it is possible to obtain a reasonable 1 : 1 copy of droplets to the particles. All these, indicate that using relationship between We and droplet size allow one to obtain acceptable condition of droplet nucleation in miniemulsion polymerization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011