bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribulus terrestris protects rat myocardium against isoproterenol-induced ischemic injury: role of HSP 70 and cardiac endogenous antioxidants
Authors: Mohanty Ipseeta Ray , Maheswari Ujjwala , Joseph Daniel , Deshmukh Yeshwant
Published: December 2011

The present study was undertaken to evaluate the cardioprotective activity of Tribulus terrestris (Tt), a medicinal herb following isoproterenol (ISP)-induced myocardial injury. The contribution of heat shock protein (HSP) 70, key anti-stress protein, endogenous antioxidants and oxidant -antioxidant balance in attenuating myocardial injury was further studied. Hydroalcoholic extract of Tt {1, 2.5, 5 & 10 mg/kg} were orally fed once a daily to Wistar rats for 21 days. On the 20th and 21st day, both control (ISP control) and Tt fed rats were challenged with ISP (85 mg/ kg, s. c. two doses at 24h intervals) induced myocardial necrosis. Histopathological evaluation, cardiac marker enzyme: Creatinine phospho - kinase(CPK) and antioxidative parameters: Glutathione (GSH), Thiobarbituric acid reactive substances (TBARS), Catalase (CAT), Glutathione peroxidase (GSHPx) and Superoxide dismutase (SOD) levels were estimated. Tt (2.5 mg/kg) intake per se upregulated HSP 70; increased basal SOD, CAT activity (P<0.05) and caused a marked fall in basal TBARS levels (P<0.05) in comparison to sham. Following ISP challenge, significant oxidative stress with evidence of myocardial necrosis was observed in the ISP control group. ISPinduced changes in myocardial SOD, GSHPx and GSH were prevented by both the 2.5 and 10 mg/kg doses of Tt, though cellular injury was minimal with 2.5 mg/kg dose. The results emphasize that pre-treatment with Tt offered significant protection against ISP-induced myocardial necrosis through a unique property of enhancement of endogenous antioxidants, stabilization of cytoskeleton structure which in turn is attributed to HSP 70 expression along with fortified antioxidant defense system.
Subacute thyroiditis after seasonal influenza vaccination
Authors: Yakushiji Fumiatsu , Ohnishi Kenji , Yasuda Mutsuko , Kobayashi Taiichiro , Kinoshita Hiroyuki
Published: December 2011

We report the first patient with subacute thyroiditis after influenza vaccination in Japan. A 49-year-old woman received a seasonal influenza vaccination in October 2009. She also received a seasonal influenza vaccination in 2008. After the vaccination, she experienced spontaneous pain and tenderness in the right lower neck. Together with the results of laboratory examinations and thyroid echography, we established the diagnosis of subacute thyroiditis. The patient had human leukocyte antigens (HLAs) of A2/A11 and B62/B35. HLA-A2-positive is reported at a risk of interferon-alpha-induced autoimmune thyroid disorder, and HLA-B35-positive is reported at a risk of subacute thyroiditis. Since fever and cervical pain are reported as adverse effects of influenza vaccination, subacute thyroiditis after influenza vaccination might have been missed.
Fabrication and intracellular delivery of siRNA/carbonate apatite nano-composites for effective knockdown of cyclin B1 gene
Authors: Stanislaus Anthony , Hossain Sharif , Chua Ming Jang , Kunnath Anil Philip , Wen Quek Chia , Syakira Sharifah Nur , Siong Gan Yew , Loong Siong Wei , Othman Iekhsan , Akaike Toshihiro , Chowdhury Ezharul Hoque
Published: December 2011

Gene therapy through intracellular delivery of a functional gene or a gene-silencing element is a promising approach to properly treat critical human diseases like cancer. The ability of synthetically designed small interfering RNA (siRNA) to effectively silence genes at post-transcriptional level has made them attractive options in targeted therapeutics. However, naked siRNA being unable to passively diffuse through cellular membranes, poses difficulty in fully exploiting the potential of the technology. pH-sensitive carbonate apatite has been developed as an efficient tool to deliver siRNA into the mammalian cells by virtue of its high affinity interaction with the siRNA and effective cellular endocytosis. Moreover, internalized siRNA has been found to escape from the endosomes in a time-dependent manner and effectively silenced reporter gene expression. Knockdown of cyclin B1 gene with only 10 nM of siRNA delivered by carbonate apatite has resulted in significant death of cervical cancer cells. Moreover, delivery of siRNA against cyclin B1 gene has led to the sensitization of the cancer cells to both cisplatin and doxorubicin at a particulat drug concentration. Thus, the new method of siRNA delivery is highly promising for pre-clinical and clinical cancer therapy using siRNA therapeutics.
Primary stroke prevention and hypertension treatment: which is the first-line strategy?
Authors: Ravenni Roberta , Jabre Joe , Casiglia Edoardo , Mazza Alberto
Published: December 2011

Hypertension (HT) iis considered the main classic vascular risk factor for stroke and the importance of lowering blood pressure (BP) is well established. However, not all the benefit of antihypertensive treatment is due to BP reduction per se, as the effect of reducing the risk of stroke differs among classes of antihypertensive agents. Extensive evidences support that angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), dihydropyridine calcium channel blockers (CCB) and thiazide diuretics each reduced risk of stroke compared with placebo or no treatment. Therefore, when combination therapy is required, a combination of these antihypertensive classes represents a logical approach. Despite the efficacy of antihypertensive therapy a large proportion of the population, still has undiagnosed or inadequately treated HT, and remain at high risk of stroke. In primary stroke prevention current guidelines recommend a systolic/diastolic BP goal of <140/<90 mmHg in the general population and <130/80 mmHg in diabetics and in subjects with high cardiovascular risk and renal disease. The recent release in the market of the fixed-dose combination (FDC) of ACEI or ARB and CCB should provide a better control of BP. However to confirm the efficacy of the FDC in primary stroke prevention, clinical intervention trials are needed.
Mycobacterium ulcerans Infection (Buruli Ulcer) on the Face: A Comparative Analysis of 13 Clinically Suspected Cases from the Democratic Republic of Congo
Authors: Phanzu Delphin M. , Mahema Roger L. , Suykerbuyk Patrick , Imposo Désiré-Hubert B. , Lehman Linda F. , Nduwamahoro Elie , Meyers Wayne M. , Boelaert Marleen , Portaels Françoise
Published: December 2011

We report our experience in managing 13 consecutive clinically suspected cases of Buruli ulcer on the face treated at the hospital of the Institut Médical Evangélique at Kimpese, Democratic Republic of Congo diagnosed during 2003–2007. During specific antibiotherapy, facial edema diminished, thus minimizing the subsequent extent of surgery and severe disfigurations. The following complications were observed: 1) lagophthalmos from scarring in four patients and associated ectropion in three of them; 2) blindness in one eye in one patient; 3) disfiguring exposure of teeth and gums resulting from excision of the left labial commissure that affected speech, drinking, and eating in one patient; and 4) dissemination of Mycobacterium ulcerans infection in three patients. Our study highlights the importance of this clinical presentation of Buruli ulcer, and the need for health workers in disease-endemic areas to be aware of the special challenges management of Buruli ulcer on the face presents.
Candidate Vectors and Rodent Hosts of Venezuelan Equine Encephalitis Virus, Chiapas, 2006–2007
Authors: Deardorff Eleanor R. , Estrada-Franco Jose G. , Freier Jerome E. , Navarro-Lopez Roberto , Da Rosa Amelia Travassos , Tesh Robert B. , Weaver Scott C.
Published: December 2011

Enzootic Venezuelan equine encephalitis virus (VEEV) has been known to occur in Mexico since the 1960s. The first natural equine epizootic was recognized in Chiapas in 1993 and since then, numerous studies have characterized the etiologic strains, including reverse genetic studies that incriminated a specific mutation that enhanced infection of epizootic mosquito vectors. The aim of this study was to determine the mosquito and rodent species involved in enzootic maintenance of subtype IE VEEV in coastal Chiapas. A longitudinal study was conducted over a year to discern which species and habitats could be associated with VEEV circulation. Antibody was rarely detected in mammals and virus was not isolated from mosquitoes. Additionally, Culex (Melanoconion) taeniopus populations were found to be spatially related to high levels of human and bovine seroprevalence. These mosquito populations were concentrated in areas that appear to represent foci of stable, enzootic VEEV circulation.
Nurturing the Global Workforce in Clinical Research: The National Institutes of Health Fogarty International Clinical Scholars and Fellows Program
Authors: Heimburger Douglas C. , Carothers Catherine Lem , Gardner Pierce , Primack Aron , Warner Tokesha L. , Vermund Sten H.
Published: December 2011

The Fogarty International Clinical Research Scholars and Fellows Program's goal is to foster the next generation of clinical investigators and to help build international health research partnerships between American and international investigators and institutions. Through June 2012, 61 sites in 27 countries have hosted 436 Scholars (American students or junior trainees from the host countries) and/or 122 Fellows (American and host country postdoctoral fellows) for year-long experiences in global health research. Initially, the program was oriented toward infectious diseases, but recently emphasis on chronic disease research has increased. At least 521 manuscripts have been published, many in high-impact journals. Projects have included clinical trials, observational studies, translational research, clinical-laboratory interface initiatives, and behavioral research. Strengths of the program include training opportunities for American and developing country scientists in well-established international clinical research settings, and mentorship from experienced global health experts.
Inhibitory Activity of Ferroquine, versus Chloroquine, against Western Kenya Plasmodium falciparum Field Isolates Determined by a SYBR Green I In Vitro Assay
Authors: Eyase Fredrick L. , Akala Hoseah M. , Johnson Jacob D. , Walsh Douglas S.
Published: December 2011

Ferroquine (FQ), a chloroquine (CQ) analog, is being developed to treat persons with Plasmodium falciparum malaria. In 146 P. falciparum field isolates from western Kenya, we measured 50% inhibitory concentrations (IC50; nM) of CQ and FQ by a SYBR Green I in vitro assay. Reference clones included W2 (CQ resistant) and D6 (CQ sensitive). Mutation analysis was done for P. falciparum CQ-resistance transporter gene (Pfcrt K76T). Median IC50 values for FQ were lower than CQ for field isolates and the W2 clone (both P < 0.05). The Pfcrt mutation (76T), which was detected in > 80% of isolates, conferred higher CQ IC50 values (P < 0.05) and modestly lower FQ IC50 values (P < 0.05), versus Pfcrt wild type (K76). FQ is more potent than CQ against CQ-resistant P. falciparum field isolates and the W2 clone, and is less affected by Pfcrt 76T. These findings support the notion that FQ could be useful in treating persons with P. falciparum malaria.
Learning Curve of Vesico-Urinary Ultrasonography in Schistosoma haematobium Infection with WHO Practical Guide: A “Simple to Learn” Examination
Authors: Bonnard Philippe , Boutouaba Samy , Diakhate Ibrahima , Seck Modou , Dompnier Jean-Pierre , Riveau Gilles
Published: December 2011

In developing countries, it is difficult to rally a radiologist to conduct field studies. Here, we report how a radiologist taught a clinician to carry out the ultrasound examination as defined by the World Health Organization (WHO) record sheet for Schistosoma haematobium related lesions. In a population infected with S. haematobium, the learner and teacher performed two ultrasound exams and the results were compared. One hundred thirty-two children were prospectively included, during 8 ultrasonography sessions split over 23 days. After 51 examinations the learner's sensitivity was above 90%. After the fifth session the specificity reached 100% (results remained stable until the end of the study period). This study shows that a clinician can quickly learn how to carry out a simple ultrasound examination to gather the items needed for the follow-up of S. haematobium related lesions, suggesting that clinicians could implement networks of ultrasound-based surveillance on the field.
Amebiasis-Related Mortality among United States Residents, 1990–2007
Authors: Gunther Janelle , Shafir Shira , Bristow Benjamin , Sorvillo Frank
Published: December 2011

Despite the endemic nature of Entamoeba histolytica infection in the United States there is a lack of data on amebiasis-related mortality. We analyzed national death certificate data from 1990 to 2007 to assess the occurrence of amebiasis-related deaths and determine demographic and regional associations. A total of 134 deaths were identified. Mortality rates were highest in males, Hispanics, Asian/Pacific Islanders, and persons 75 years of age and older. An association with human immunodeficiency virus infection was also observed. A declining trend of amebiasis deaths was noted over the 18-year study period. Over 40% of fatal amebiasis cases occurred in residents of California and Texas. United States-born persons accounted for the majority of amebiasis deaths; however, all of the fatalities in Asian/Pacific Islanders and 60% of the deaths in Hispanics were in foreign-born individuals. Although uncommon, amebiasis-related deaths routinely occur in the United States.
Elimination of Borrelia burgdorferi and Anaplasma phagocytophilum in Rodent Reservoirs and Ixodes scapularis Ticks Using a Doxycycline Hyclate-Laden Bait
Authors: Dolan Marc C. , Schulze Terry L. , Jordan Robert A. , Dietrich Gabrielle , Schulze Christopher J. , Hojgaard Andrias , Ullmann Amy J. , Sackal Cherilyn , Zeidner Nordin S. , Piesman Joseph
Published: December 2011

A field trial was conducted in a Lyme disease-endemic area of New Jersey to determine the efficacy of a doxycyline hyclate rodent bait to prophylactically protect and cure small-mammal reservoirs and reduce infection rates in questing Ixodes scapularis ticks for Borrelia burgdorferi and Anaplasma phagocytophilum. The doxycycline-laden bait was formulated at a concentration of 500 mg/kg and delivered during the immature tick feeding season in rodent-targeted bait boxes. The percentage of infected small mammals recovered from treated areas after 2 years of treatment was reduced by 86.9% for B. burgdorferi and 74% for A. phagocytophilum. Infection rates in questing nymphal ticks for both B. burgdorferi and A. phagocytophilum were reduced by 94.3% and 92%, respectively. Results from this study indicate that doxycycline-impregnated bait is an effective means of reducing infection rates for B. burgdorferi and A. phagocytophilum in both rodent reservoirs and questing I. scapularis ticks.
Analysis of Polymorphisms in the Merozoite Surface Protein-3α Gene and Two Microsatellite Loci in Sri Lankan Plasmodium vivax: Evidence of Population Substructure in Sri Lanka
Authors: Schousboe Mette L. , Rajakaruna Rupika S. , Amerasinghe Priyanie H. , Konradsen Flemming , Ord Rosalynn , Pearce Richard , Bygbjerg Ib C. , Roper Cally , Alifrangis Michael
Published: December 2011

The geographical distribution of genetic variation in Plasmodium vivax samples (N = 386) from nine districts across Sri Lanka is described using three markers; the P. vivax merozoite surface protein-3α (Pvmsp-3α) gene, and the two microsatellites m1501 and m3502. At Pvmsp-3α, 11 alleles were found with an expected heterozygosity (He) of 0.81, whereas at m1501 and m3502, 24 alleles (He = 0.85) and 8 alleles (He = 0.74) were detected, respectively. Overall, 95 unique three locus genotypes were detected among the 279 samples positive at all three loci (He = 0.95). Calculating the pairwise fixation index (FST) revealed statistically significant population structure. The presence of identical 2-loci microsatellite genotypes in a significant proportion of samples revealed local clusters of closely related isolates contributing to strong linkage disequilibrium between marker alleles. The results show evidence of high genetic diversity and possible population substructure of P. vivax populations in Sri Lanka.
Prevalence of Malaria among Patients Attending Public Health Facilities in Maputo City, Mozambique
Authors: Macedo de Oliveira Alexandre , Mutemba Rosalia , Morgan Juliette , Streat Elizabeth , Roberts Jacquelin , Menon Manoj , Mabunda Samuel
Published: December 2011

We conducted a health facility-based survey to estimate the prevalence of malaria among febrile patients at health facilities (HFs) in Maputo City. Patients answered a questionnaire on malaria risk factors and underwent malaria testing. A malaria case was defined as a positive result for malaria by microscopy in a patient with fever or history of fever in the previous 24 hours. Among 706 patients with complete information, 111 (15.7%) cases were identified: 105 were positive for Plasmodium falciparum only, two for Plasmodium ovale only, and four for both P. falciparum and P. ovale. Fever documented at study enrollment, age ≥ 5 years, rural HF, and travel outside Maputo City were statistically significantly associated with malaria by multivariate analysis. We found a high prevalence of laboratory-confirmed malaria among febrile patients in Maputo City. Further studies are needed to relate these findings with mosquito density to better support malaria prevention and control.
Spatial Stability of Adult Aedes aegypti Populations
Authors: Barrera Roberto
Published: December 2011

Vector control programs could be more efficient by identifying the location of highly productive sites of Aedes aegypti. This study explored if the number of female adults of Ae. aegypti in BG-Sentinel traps was clustered and if their spatial distribution changed in time in two neighborhoods in San Juan, Puerto Rico. Traps were uniformly distributed across each neighborhood (130 m from each other), and samples were taken every 3 weeks. Global and local spatial autocorrelations were explored. Spatial stability existed if the rank order of trap captures was kept in time. There was lack of global autocorrelation in both neighborhoods, precluding their stratification for control purposes. Hot and cold spots were identified, revealing the highly focal nature of Ae. aegypti. There was significant spatial stability throughout the study in both locations. The consistency in trap productivity in time could be used to increase the effectiveness of vector and dengue control programs.
Help-Seeking for Pre-Ulcer and Ulcer Conditions of Mycobacterium ulcerans Disease (Buruli Ulcer) in Ghana
Authors: Ackumey Mercy M. , Gyapong Margaret , Pappoe Matilda , Weiss Mitchell G.
Published: December 2011

This study examined sociocultural features of help-seeking for Buruli ulcer–affected persons with pre-ulcers and ulcers in a disease-endemic area in Ghana. A sample of 181 respondents were purposively selected. Fisher's exact test was used to compare help-seeking variables for pre-ulcers and ulcers. Qualitative phenomenologic analysis of narratives clarified the meaning and content of selected quantitative help-seeking variables. For pre-ulcers, herbal dressings were used to expose necrotic tissues and subsequently applied as dressings for ulcers. Analgesics and left-over antibiotics were used to ease pain and reduce inflammation. Choices for outside-help were influenced by the perceived effectiveness of the treatment, the closeness of the provider to residences, and family and friends. Health education is required to emphasize the risk of self-medication with antibiotics and the importance of medical treatment for pre-ulcers, and to caution against the use of herbs to expose necrotic tissues, which could lead to co-infections.
Molecular Insights for Giardia, Cryptosporidium, and Soil-Transmitted Helminths from a Facility-Based Surveillance System in Guatemala
Authors: Velasquez Daniel E. , Arvelo Wences , Cama Vitaliano A. , López Beatriz , Reyes Lissette , Roellig Dawn M. , Kahn Geoffrey D. , Lindblade Kimberly A.
Published: December 2011

We molecularly characterized samples with Giardia, Cryptosporidium, and soil-transmitted helminths from a facility-based surveillance system for diarrhea in Santa Rosa, Guatemala. The DNA sequence analysis determined the presence of Giardia assemblages A (N = 7) and B (N = 12) and, Cryptosporidium hominis (N = 2) and Cryptosporidium parvum (N = 2), suggestive of different transmission cycles. All 41 samples with soil-transmitted helminths did not have the β-tubulin mutation described for benzimidazole resistance, suggesting potential usefulness in mass drug administration campaigns.
Acute Renal Injury as a Result of Liposomal Amphotericin B Treatment in Sodium Stibogluconate Unresponsive Visceral Leishmaniasis
Authors: Zhao Songtao , Zhang Dongxia , Li Ling , Mao Qing
Published: December 2011

We report an unusual case of visceral leishmaniasis occurring in a patient from Sichuan China. The patient presented with a remitting fever, anemia, and pancytopenia. The case was confirmed as visceral leishmaniasis by microscopical detection of the Leishmania species amastigote in bone marrow aspirate. The patient was treated with 10 mg/kg/day of sodium stibogluconate for 5 days, with no therapeutic response. As a result, the patient was treated with liposomal amphotericin B (LAB) at 10 mg/day as an initial dosage. After treatment with an increasing drug dosage for 7 days, acute renal injury was evident as indicated by increased serum creatinine and urea nitrogen. LAB administration was discontinued until serum creatinine and serum urea nitrogen regressed on Day 15. Two maintenance treatments of 100 mg/day LAB were given on Days 19 and 26 (total 870 mg, 14.5 mg/kg). Bone marrow aspirate and clinical examination suggested total remission.
Review: Malaria Chemoprophylaxis for Travelers to Latin America
Authors: Steinhardt Laura C. , Magill Alan J. , Arguin Paul M.
Published: December 2011

Because of recent declining malaria transmission in Latin America, some authorities have recommended against chemoprophylaxis for most travelers to this region. However, the predominant parasite species in Latin America, Plasmodium vivax, can form hypnozoites sequestered in the liver, causing malaria relapses. Additionally, new evidence shows the potential severity of vivax infections, warranting continued consideration of prophylaxis for travel to Latin America. Individualized travel risk assessments are recommended and should consider travel locations, type, length, and season, as well as probability of itinerary changes. Travel recommendations might include no precautions, mosquito avoidance only, or mosquito avoidance and chemoprophylaxis. There are a range of good options for chemoprophylaxis in Latin America, including atovaquone-proguanil, doxycycline, mefloquine, and—in selected areas—chloroquine. Primaquine should be strongly considered for nonpregnant, G6PD-nondeficient patients traveling to vivax-endemic areas of Latin America, and it has the added benefit of being the only drug to protect against malaria relapses.
Molecular Characterization of Blastocystis Obtained from Members of the Indigenous Tapirapé Ethnic Group from the Brazilian Amazon Region, Brazil
Authors: Malheiros Antonio F. , Stensvold C. Rune , Clark C. Graham , Braga Guilherme B. , Shaw Jeffrey J.
Published: December 2011

A total of 382 stool samples were examined during a survey of intestinal parasites in members of the Tapirapé ethnic group, who live in the Brazilian Amazon region of Mato Grosso. Fecal DNAs from Blastocystis-positive samples were extracted, polymerase chain reaction amplified using Blastocystis-specific primers targeting the small subunit rRNA gene, and sequenced. Three subtypes (STs) were identified: ST1 (41%), ST2 (32%), and ST3 (17%). Seven mixed infections were found (11%). The subtype distribution was markedly different from that reported in Europe in that ST4 was not detected and ST3 was not the most common subtype. This study is the first to include molecular characterization of Blastocystis in Brazil and in indigenous communities from Latin America.
Review: Improving the Therapeutic Index of 8-Aminoquinolines by the Use of Drug Combinations: Review of the Literature and Proposal for Future Investigations
Authors: Myint Hla Y. , Berman Jonathan , Walker Larry , Pybus Brandon , Melendez Victor , Baird J. Kevin , Ohrt Colin
Published: December 2011

Because 8-aminoquinolines affect critical survival stages of Plasmodium parasites, treatment and control of malaria could be markedly improved by more widespread use of these drugs; however, hemolytic toxicity, which is widely prevalent in G6PD-deficient patients, severely constrains this use. Primaquine was approved more than 50 years ago after extensive clinical testing. Review of the mid-20th century literature in the light of present understanding of pharmacokinetics and metabolism suggests that manipulation of these factors might dissociate 8-aminoquinoline efficacy from toxicity and lead to an improved therapeutic index.
Hindcast experiments of tropospheric composition during the summer 2010 fires over Western Russia
Authors: Huijnen V. , Flemming J. , Kaiser J. W. , Inness A. , Leitão J. , Heil A. , Eskes H. J. , Schultz M. G. , Benedetti A. , Dufour G. , Eremenko M.
Published: December 2011

Abstract. The severe wildfires in Western Russia during July–August 2010 coincided with a strong heat wave and led to large emissions of aerosols and trace gases such as carbon monoxide (CO), hydrocarbons and nitrogen oxides into the troposphere. This extreme event is used to evaluate the ability of the global MACC (Monitoring Atmospheric Composition and Climate) atmospheric composition forecasting system to analyze large-scale pollution episodes and to test the respective influence of a priori emission information and data assimilation on the results. Daily 4-day hindcasts were conducted using assimilated aerosol optical depth (AOD), CO, nitrogen dioxide (NO2) and ozone (O3) data from a range of satellite instruments. Daily fire emissions were used from the Global Fire Assimilation System (GFAS) version 1.0, derived from satellite fire radiative power retrievals. The impact of accurate wildfire emissions is dominant on the composition in the boundary layer, whereas the assimilation system influences concentrations throughout the troposphere, reflecting the vertical sensitivity of the satellite instruments. The application of the daily fire emissions reduces the area-average mean bias by 63% (for CO), 38% (O3) and 64% (NO2) during the first 24 h, compared to a reference simulation with a multi-annual mean climatology of biomass burning emissions. When initial tracer concentrations are further constrained by data assimilation, biases are reduced by 87, 38 and 80%. The forecast accuracy, quantified by the mean bias up to 96 h lead time, was best for all compounds when using both the GFAS emissions and assimilation. The model simulations suggest an indirect positive impact of O3 and CO assimilation on hindcasts of NO2 via changes in the oxidizing capacity. However, the quality of local hindcasts was strongly depending on the assumptions made for forecasted fire emissions. This was well visible from a relatively rapid increase by the root mean square error with respect to ground-based data for AOD, and satellite based NO2. This calls for a more advanced method to forecast fire emissions than the currently adopted persistency approach. The combined analysis of fire radiative power observations, multiple trace gas and aerosol satellite observations, as provided by the MACC system, results in a detailed quantitative description of the impact of major fires on atmospheric composition, and demonstrate the capabilities for the real-time analysis and forecasts of large-scale fire events.
Direct N2O5 reactivity measurements at a polluted coastal site
Authors: Riedel T. P. , Bertram T. H. , Ryder O. S. , Liu S. , Day D. A. , Russell L. M. , Gaston C. J. , Prather K. A. , Thornton J. A.
Published: December 2011

Abstract. Direct measurements of N2O5 reactivity on ambient aerosol particles were made during September 2009 at the Scripps Institution of Oceanography (SIO) Pier facility located in La Jolla, CA. N2O5 reactivity measurements were made using a custom flow reactor and the particle modulation technique alongside measurements of aerosol particle size distributions and non-refractory composition. The pseudo-first order rate coefficients derived from the particle modulation technique and the particle surface area concentrations were used to determine the population average N2O5 reaction probability, γ(N2O5), approximately every 50 min. Insufficient environmental controls within the instrumentation trailer led us to restrict our analysis primarily to nighttime measurements. Within this subset of data, γ(N2O5) ranged from <0.001 to 0.029 and showed significant day-to-day variations. We compare these data to a recent parameterization that utilizes aerosol composition measurements and an aerosol thermodynamics model. The parameterization captures several aspects of the measurements with similar general trends over the time series. However, the parameterization persistently overestimates the measurements by a factor of 1.5–3 and does not illustrate the same extent of variability. Assuming chloride is internally mixed across the particle population leads to the largest overestimates. Removing this assumption only partially reduces the discrepancies, suggesting that other particle characteristics that can suppress γ(N2O5) are important, such as organic coatings or non-aqueous particles. The largest apparent driver of day-to-day variability in the measured γ(N2O5) at this site was the particle nitrate loading, as inferred from both the measured particle composition and the parameterizations. The relative change in measured γ(N2O5) as a function of particle nitrate loading appears to be consistent with expectations based on laboratory data, providing direct support for the atmospheric importance of the so-called "nitrate effect".
How to average logarithmic retrievals
Authors: Funke B. , von Clarmann T.
Published: December 2011

Abstract. Calculation of mean trace gas contributions from profiles obtained by retrievals of the logarithm of the abundance rather than retrievals of the abundance itself are prone to biases. By means of a system simulator, biases of linear versus logarithmic averaging were evaluated for both maximum likelihood and maximum a priori retrievals, for various signal to noise ratios and atmospheric variabilities. These biases can easily reach several ten percent. As a rule of thumb we found for maximum likelihood retrievals that linear averaging better represents the true mean value in cases of large local natural variability and high signal to noise ratios, while for small local natural variability logarithmic averaging often is superior. In the case of maximum a posteriori retrievals, the mean is dominated by the a priori information used in the retrievals and the method of averaging is of minor concern. For larger natural variabilities, the appropriateness of the one or the other method of averaging depends on the particular case because the various biasing mechanisms partly compensate in a hardly predictable manner. This complication arises mainly because of the fact that in logarithmic retrievals the weight of the prior information depends on abundance of the gas itself. No simple rule was found on which kind of averaging is superior, and instead of suggesting simple recipes we cannot do much more than to create awareness of the traps related with averaging of mixing ratios obtained from logarithmic retrievals.
Effect of wind speed on aerosol optical depth over remote oceans, based on data from the Maritime Aerosol Network
Authors: Smirnov A. , Sayer A. M. , Holben B. N. , Hsu N. C. , Sakerin S. M. , Macke A. , Nelson N. B. , Courcoux Y. , Smyth T. J. , Croot P. , Quinn P. K. , Sciare J. , Gulev S. K. , Piketh S. , Losno R. , Kinne S. , Radionov V. F.
Published: December 2011

Abstract. The Maritime Aerosol Network (MAN) has been collecting data over the oceans since November 2006. The MAN archive provides a valuable resource for aerosol studies in maritime environments. In the current paper we investigate correlations between ship-borne aerosol optical depth (AOD) and near-surface wind speed, either measured (onboard or from satellite) or modeled (NCEP). According to our analysis, wind speed influences columnar aerosol optical depth, although the slope of the linear regression between AOD and wind speed is not steep (∼0.004–0.005), even for strong winds over 10 m s−1. The relationships show significant scatter (correlation coefficients typically in the range 0.3–0.5); the majority of this scatter can be explained by the uncertainty on the input data. The various wind speed sources considered yield similar patterns. Results are in good agreement with the majority of previously published relationships between surface wind speed and ship-based or satellite-based AOD measurements. The basic relationships are similar for all the wind speed sources considered; however, the gradient of the relationship varies by around a factor of two depending on the wind data used.
Influence of aerosol and surface reflectance variability on hyperspectral observed radiance
Authors: Bassani C. , Cavalli R. M. , Antonelli P.
Published: December 2011

Abstract. Physically based retrievals of aerosol properties from remotely sensed data usually requires extensive assumptions on particulate type and vertical distribution, and ground surface reflectivity. New satellite missions, based on high spectral resolution instruments, such as PRISMA (Hyperspectral Precursor and Application Mission), represent a valuable opportunity to mitigate the dependency of the retrieval accuracy from the such (a-priori) information. This paper aims to address the potential of these new observing systems in retrieving aerosol properties specifically over coastal areas. Goal has been achieved by using simulated radiances obtained combining two aerosol models (urban and continental), and two reflecting surfaces, dark (water) and bright (sand) for the PRISMA instrument. Results showed that, in the continental regime, the expected instrument sensitivity would allow for retrieval accuracy of the optical thickness at 550 nm of 0.02 or better, with a dark surface surrounded by dark areas. Study also showed that for the urban regime, the surface plays a more significant role, with a bright surface surrounded by dark areas providing the best conditions for the aerosol load retrievals, and dark surfaces representing less suitable situations for accurate retrievals independently of the surroundings. Moreover the results obtained, led the authors to the conclusions that high resolution observations of Earth spectrum between 400 and 1000 nm, through the use of a physically based inversion system, would allow for a significant improvement of the retrieval accuracy for anthropogenic/natural aerosol, over coastal regions.
Snow and weather climatic control on snow avalanche occurrence fluctuations over 50 yr in the French Alps
Authors: Castebrunet H. , Eckert N. , Giraud G.
Published: December 2011

Abstract. Snow avalanche activity is controlled to a large extent by snow and weather patterns. However, its response to climate fluctuations remains poorly documented. Previous studies have focused on direct extraction of trends in avalanche and winter climate data, and this study employs a time-implicit method to model annual avalanche activity in the French Alps during the 1958–2009 period from its most representative climatic drivers. Modeled snow and weather data for different elevations and aspects are considered as covariates that explain actual observed avalanche counts, modeled instability indexes, and a combination of both avalanche activity indicators. These three series present relatively similar fluctuations over the period and good consistency with historically harsh winters. A stepwise procedure is used to obtain regression models that accurately represent trends as well as high and low peaks with a small number of physically meaningful covariates, showing their climatic relevance. The activity indicators and their regression models seen as time series show, within a high interannual variability, a predominant bell-shaped pattern presumably related to a short period of colder and snowier winters around 1980, as well as a very slight but continuous increase between 1975 and 2000 concomitant with warming. Furthermore, the regression models quantify the respective weight of the different covariates, mostly temperature anomalies and south-facing snowpack characteristics to explain the trends and most of the exceptional winters. Regional differences are discussed as well as seasonal variations between winter and spring activity and confirm rather different snow and weather regimes influencing avalanche activity over the Northern and Southern Alps, depending on the season.
Evaluation of a Global Vegetation Model using time series of satellite vegetation indices
Authors: Maignan F. , Bréon F.-M. , Chevallier F. , Viovy N. , Ciais P. , Garrec C. , Trules J. , Mancip M.
Published: December 2011

Abstract. Atmospheric CO2 drives most of the greenhouse effect increase. One major uncertainty on the future rate of increase of CO2 in the atmosphere is the impact of the anticipated climate change on the vegetation. Dynamic Global Vegetation Models (DGVM) are used to address this question. ORCHIDEE is such a DGVM that has proven useful for climate change studies. However, there is no objective and methodological way to accurately assess each new available version on the global scale. In this paper, we submit a methodological evaluation of ORCHIDEE by correlating satellite-derived Vegetation Index time series against those of the modeled Fraction of absorbed Photosynthetically Active Radiation (FPAR). A perfect correlation between the two is not expected, however an improvement of the model should lead to an increase of the overall performance. We detail two case studies in which model improvements are demonstrated, using our methodology. In the first one, a new phenology version in ORCHIDEE is shown to bring a significant impact on the simulated annual cycles, in particular for C3 Grasses and C3 Crops. In the second case study, we compare the simulations when using two different weather fields to drive ORCHIDEE. The ERA-Interim forcing leads to a better description of the FPAR interannual anomalies than the simulation forced by a mixed CRU-NCEP dataset. This work shows that long time series of satellite observations, despite their uncertainties, can identify weaknesses in global vegetation models, a necessary first step to improving them.
Assessing rating-curve uncertainty and its effects on hydraulic model calibration
Authors: Domeneghetti A. , Castellarin A. , Brath A.
Published: December 2011

Abstract. This study considers the overall uncertainty affecting river flow measurements and proposes a framework for analysing the uncertainty of rating-curves and its effects on the calibration of numerical hydraulic models. The uncertainty associated with rating-curves is often considered negligible relative to other approximations affecting hydraulic studies, even though recent studies point out that rating-curves uncertainty may be significant. This study refers to a ∼240 km reach of River Po and simulates ten different historical flood events by means of a quasi-twodimensional (quasi-2-D) hydraulic model in order to generate 50 synthetic measurement campaigns (5 campaigns per event) at the gauged cross-section of interest (i.e. Cremona streamgauge). For each synthetic campaign, two different procedures for rating-curve estimation are applied after corrupting simulated discharges according to the indications reported in the literature on accuracy of discharge measurements, and the uncertainty associated with each procedure is then quantified. To investigate the propagation of rating-curve uncertainty on the calibration of Manning's roughness coefficients further model simulations are run downstream Cremona's cross-section. Results highlight the significant role of extrapolation errors and how rating-curve uncertainty may be responsible for estimating unrealistic roughness coefficients. Finally, the uncertainty of these coefficients is analysed and discussed relative to the variability of Manning's coefficient reported in the literature for large natural streams.
Impact of ASAR soil moisture data on the MM5 precipitation forecast for the Tanaro flood event of April 2009
Authors: Panegrossi G. , Ferretti R. , Pulvirenti L. , Pierdicca N.
Published: December 2011

Abstract. The representation of land-atmosphere interactions in weather forecast models has a strong impact on the Planetary Boundary Layer (PBL) and, in turn, on the forecast. Soil moisture is one of the key variables in land surface modelling, and an inadequate initial soil moisture field can introduce major biases in the surface heat and moisture fluxes and have a long-lasting effect on the model behaviour. Detecting the variability of soil characteristics at small scales is particularly important in mesoscale models because of the continued increase of their spatial resolution. In this paper, the high resolution soil moisture field derived from ENVISAT/ASAR observations is used to derive the soil moisture initial condition for the MM5 simulation of the Tanaro flood event of April 2009. The ASAR-derived soil moisture field shows significantly drier conditions compared to the ECMWF analysis. The impact of soil moisture on the forecast has been evaluated in terms of predicted precipitation and rain gauge data available for this event have been used as ground truth. The use of the drier, highly resolved soil moisture content (SMC) shows a significant impact on the precipitation forecast, particularly evident during the early phase of the event. The timing of the onset of the precipitation, as well as the intensity of rainfall and the location of rain/no rain areas, are better predicted. The overall accuracy of the forecast using ASAR SMC data is significantly increased during the first 30 h of simulation. The impact of initial SMC on the precipitation has been related to the change in the water vapour field in the PBL prior to the onset of the precipitation, due to surface evaporation. This study represents a first attempt to establish whether high resolution SAR-based SMC data might be useful for operational use, in anticipation of the launch of the Sentinel-1 satellite.
OntoFire: an ontology-based geo-portal for wildfires
Authors: Kalabokidis K. , Athanasis N. , Vaitis M.
Published: December 2011

Abstract. With the proliferation of the geospatial technologies on the Internet, the role of geo-portals (i.e. gateways to Spatial Data Infrastructures) in the area of wildfires management emerges. However, keyword-based techniques often frustrate users when looking for data of interest in geo-portal environments, while little attention has been paid to shift from the conventional keyword-based to navigation-based mechanisms. The presented OntoFire system is an ontology-based geo-portal about wildfires. Through the proposed navigation mechanisms, the relationships between the data can be discovered, which would otherwise not be possible when using conventional querying techniques alone. End users can use the browsing interface to find resources of interest by using the navigation mechanisms provided. Data providers can use the publishing interface to submit new metadata, modify metadata or removing metadata in/from the catalogue. The proposed approach can improve the discovery of valuable information that is necessary to set priorities for disaster mitigation and prevention strategies. OntoFire aspires to be a focal point of integration and management of a very large amount of information, contributing in this way to the dissemination of knowledge and to the preparedness of the operational stakeholders.
Circulating Sex Hormones and Tumor Characteristics in Postmenopausal Breast Cancer Patients. A Cross-Sectional Study
Authors: Secreto Giorgio , Meneghini Elisabetta , Venturelli Elisabetta , Cogliati Patrizia , Agresti Roberto , Ferraris Cristina , Gion Massimo , Zancan Matelda , Fabricio Aline S.C. , Berrino Franco , Cavalleri Adalberto , Micheli Andrea
Published: December 2011

Background

To further investigate the role of sex hormones in breast cancer, we assessed the relations of circulating estradiol and testosterone to tumor size and estrogen receptor (ER) status.

Method

This was a cross-sectional study including 492 postmenopausal breast cancer patients. The relation of circulating hormones to patient and tumor characteristics was assessed using the Fisher or Cuzick tests. Multivariable logistic regression was used to estimate the odds ratios (ORs) of having tumors ≥2 cm (vs <2 cm) and having ER-positive tumors (vs ER-negative) with increasing quartiles of estradiol and testosterone.

Results

Mean estradiol and testosterone levels increased significantly with increasing tumor size. The ORs of tumors ≥2 cm increased significantly with increasing quartiles of estradiol (Ptrend<0.001) and testosterone (Ptrend=0.005). When adjusted for estradiol, the association between testosterone and tumor size was no longer significant. Mean testosterone levels were higher in ER-positive than ER-negative patients (P<0.001), while mean estradiol levels did not differ significantly between the two ER categories (p=0.192). The ORs of having an ER-positive tumor increased significantly with increasing quartiles of testosterone (Ptrend=0.002), whereas the increase with increasing estradiol quartiles was not significant (Ptrend=0.07).

Conclusion

The association of both hormones with tumor size implies that both are involved in tumor growth, testosterone mainly by conversion to estradiol. The strong association of testosterone with ER contrasts with the weak association of estradiol with ER and confirms testosterone as a marker of hormone-dependent tumors. These findings suggest that testosterone evaluation might be useful to better identify patients with hormone-dependent disease.
Potential Contributors to the Canadian Pediatric Obesity Epidemic
Authors: Saunders Travis
Published: December 2011

As a group, Canadian children and youth are heavier than at any time in the recent past. However, to date there has been no critical examination of the factors which are likely to have contributed to these deleterious trends. A review of the evidence suggests that there is robust evidence supporting the role of reduced sleep, increased sedentary time, increased consumption of sugar-sweetened beverages, and secular increases in adult obesity as contributing factors to the current epidemic of childhood obesity. There is moderate evidence that these trends are related to changes in either total energy intake or physical activity, while there is very little evidence supporting the role of maternal age, breastfeeding, exposure to endocrine disrupters, or inadequate calcium intake. These findings suggest that targeting sleep, sedentary time, and sugar-sweetened beverage intake in Canadian children and youth may help to prevent future weight gain at the population level.
Quadruple Fixed Point Theorems for Weak ϕ-Contractions
Authors: Karapınar Erdal
Published: December 2011

The notion of coupled fixed point is introduced in by Gnana Bhaskar and Lakshmikantham (2006). Very recently, the concept of tripled fixed point is introduced by Berinde and Borcut (2011). In this paper, quadruple fixed point is introduced, and some new fixed point theorems are obtained.