203 research outputs found

    Architecture and solar energy: Is there anything new?

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    Não há dúvidas quanto à evolução do aproveitamento da energia solar e ao progresso acelerado das técnicas capazes de explorar esta forma de energia. A novidade está na transformação da radiação solar em eletricidade da qual a humanidade não prescinde mais, mas outras formas de se utilizar esta energia, luz e calor, e notadamente na arquitetura e nas construções são tão antigas quanto a história registrada. Mesmo assim, a assimilação de tais possibilidades na arte de construir ainda parece caminhar lentamente. A pergunta que orienta este artigo busca indagar se a adoção desta forma de energia trará modificações na forma dos edifícios e no desenho urbano, vindo a transformar a paisagem das cidades? Um breve levantamento do “estado da arte” tenta elucidar estas questões.There is no doubt as to the evolution of the solar energy yield and the accelerated progress of techniques able to exploit this type of energy. The novelty lies in the transformation of solar radiation into electricity, which mankind cannot disregard anymore, but other ways to use such energy, light and heat, which are as old as the recorded in the architecture history and constructions. Even so, the assimilation of such possibilities in the constructing art still looks going on slowly. The question that guides this article seeks to ask if the adoption of this form of energy will bring changes in the form of buildings and urban design, transforming the landscape of the cities. A brief survey of the “state of the art” attempts to clarify these issues

    Brucella melitensis biovar 1 isolation in a captive wildlife population in the United Arab Emirates. First isolation in the scimitar-horned Oryx (Oryx dammah)

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    In 2013, Brucella melitensis biovar 1 was recovered from the stomach contents of a scimitar-horned Oryx - SHO (Oryx dammah) aborted foetus, and from the articular fluid of a sand gazelle (Gazella marica) in a captive wildlife collection near Abu Dhabi, United Arab Emirates. Other evidence of exposure to the pathogen was collected through serological testing (Rose Bengal test) and B. melitensis-specific PCR of samples from captive wildlife kept in six different enclosures. A Multiple Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) using 15 markers showed that the two strains isolated in animals kept in enclosures, located 1300 m apart from each other, shared an identical genotype. The phylogenetic analysis of MLVA-15 profiles retrieved from the public database suggested that these strains belong to the African clade, clustering regionally in the UAE, Oman and Qatar. This is the first confirmed case of B. melitensis in a SHO, an African antelope extinct in the wild and warrants further investigation

    Seroprevalence of brucellosis in patients with prolonged fever in Bangladesh

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    Introduction: This study describes the seroprevalence of human brucellosis among pyretic patients and detection of Brucella abortus DNA from seropositive pyretic patients using real-time polymerase chain reaction (rtPCR) for the first time in Bangladesh. Methodology: Blood samples were collected from 300 pyretic patients from October 2007 to May 2008 and subjected to three serological tests: Rose-Bengal plate test (RBT), standard tube agglutination test (STAT), and indirect enzyme-linked immunosorbent assay (iELISA). Risk factors were identified by multivariate Firth’s logistic regression analysis. Brucella genus (BCSP31) and species-specific (IS711) rtPCR were applied to six human sera samples. Results: The seroprevalence of brucellosis among pyretic patients was estimated to be 2.0% (95% confidence interval [CI]: 0.74–4.30). The odds of brucellosis seropositivity were 8.9 (95% CI: 1.26–63.0) times higher in pyretic patients who handled goats than those who handled only cattle, whereas the odds of brucellosis seropositivity were 9.7 (95% CI: 1.28–73.68) times higher in pyretic patients who had backache compared to those without backache. B. abortus DNA was amplified from all six human sera that tested positive by RBT, STAT, and iELISA. As the agreement between the tests was very strong, RBT is recommended as a screening test for the diagnosis of human brucellosis in Bangladesh because it is easier to use, cheaper, and faster. Conclusions: Brucellosis among pyretic patients is common, and B. abortus is responsible for brucellosis in such patients. Pyretic patients who handle goats and those with backaches should be screened for brucellosis

    Performance of two commercial serological assays for bovine tuberculosis using plasma samples.

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    peer reviewedIn the bovine tuberculosis diagnosis, the use of plasma samples (already available for IFNɣ assays) in serological tests might facilitate the work in the field. Here, the performance of two commercial serological tests (ELISA IDEXX M. bovis Ab test and Enferplex Bovine TB antibody test) were evaluated using plasma samples from cattle in Belgium. Specificity values estimated from 567 plasma samples collected from bTB-free cattle were 98.4% when using the ELISA IDEXX M. bovis Ab test, and were 96.5% and 93.3% when using the high specificity and high sensitivity settings of the Enferplex Bovine TB antibody test, respectively. Sensitivity values were calculated relative to SICCT-positive (N = 117) and IFNɣ-positive (N = 132) animals originating from M. bovis-infected herds. Overall, the multiplexed Enferplex Bovine TB antibody test had better sensitivity (mean: 32.5% and 43.4% for the high specificity and sensitivity settings, respectively) compared to the ELISA IDEXX M. bovis Ab test (mean: 12%). Data obtained from plasma samples in the current study were compared to a previous study using both serological tests with sera. In conclusion, both serological tests showed comparable performance with both matrix; although overall specificity values with the Enferplex Bovine TB antibody test were lower when using plasma samples than sera

    Field evaluation of two commercial serological assays for detecting bovine tuberculosis.

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    peer reviewedDiagnosis of bovine tuberculosis in cattle is challenging due to complex immune host response to infection that limit the performance of available diagnostic tests. In this study, performance of two commercial serological assays developed to detect bovine tuberculosis were evaluated: Enferplex Bovine TB antibody kit including 11 antigens (EnferGroup, Ireland) and IDEXX M. bovis Ab kit (IDEXX, USA). The specificity value obtained with the ELISA IDEXX M. bovis Ab test was 97.1%, whereas it was 97.1% and 95.1% for the high specificity and sensitivity settings, respectively, with the Enferplex Bovine TB antibody kit. The sensitivity of the multiplexed Enferplex Bovine TB antibody test for SICCT-positive animals was higher (N = 172; 51.7% and 58.7% with high specificity and sensitivity settings, respectively) compared to the ELISA IDEXX M. bovis Ab test (sensitivity of 36.6%). "Antigen profiles" generated by the multiplexed Enferplex method showed that five out of 11 antigens present in the test were mostly identified as positive sera in cattle originating from bTB-outbreaks. In comparison, unique profiles appeared to be correlated with false positive results. However additional studies are needed to confirm the observed antigen profiles, and their potential use as an additional diagnostic tool. Serial interpretation of the two serological tests produced higher diagnostic specificity (>99%), reducing false positive results, which is essential for a screening test when the prevalence of bovine tuberculosis is low

    Identifcation and molecular characterization of Brucella abortus and Brucella melitensis isolated from milk in cattle in Azerbaijan

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    Background: Azerbaijan currently ranks thirteenth in global incidence of human brucellosis, with an estimated annual incidence through 2000 at over 50 cases per million. Brucella melitensis has been isolated from patients and is thought to have been acquired through contact with small ruminants or as a foodborne infection. To reduce the burden of human brucellosis, the Azerbaijani government began in 2002, a nationwide vaccination control campaign in small ruminants. There is serological evidence of bovine brucellosis (presumably due to Brucella abortus) in Azerbaijan, but no prevalence estimates were available when this study started in March 2017. The aim of this study was to isolate and identify Brucella spp. from cow milk in the Ganja region, where brucellosis takes a heavy toll on humans and livestock. Results: Blood and milk samples were collected from cows (n = 1075) in early lactation (up to 90-days) in farms that had a history of previous positive serological results and abortions. Twenty-two out of 57 milk samples collected from seropositive cows, showed growth on Farrell’s media, when incubated with 5% CO2. Eight additional milk samples showed growth in the absence of CO2. The classical biotyping classified them as Brucella abortus (22) and Brucella melitensis (8). RT-PCR confirmed that strains belonged to the genus Brucella. MLVA profiles were obtained for DNA extracted from two B. abortus and six B. melitensis strains. While the B. abortus genetic profile was described in the MLVA database, matching the profile of B. abortus strains isolated in East Europe, Central Asia and China, we found a new genotype for the B. melitensis strains isolated in Azerbaijan, clustering with strains belonging to the American clade, rarely identified in the region. Conclusion: Despite the implementation of the vaccination program in small ruminants, our results suggest that spill-over events of B. melitensis from small ruminants to cattle have occurred. However, cattle are likely to be primarily infected with B. abortus, which warranted the implementation of a bovine brucellosis program. Such a program started in fall 2017. In the Ganja region, cattle should be considered as a potential source of B. abortus and B. melitensis for humans

    Immunologic Response of Unvaccinated Workers Exposed to Anthrax, Belgium

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    To determine immunologic reactivity to Bacillus anthrax antigens, we conducted serologic testing of workers in a factory that performed scouring of wool and goat hair. Of 66 workers, ≈10% had circulating antibodies or T lymphocytes that reacted with anthrax protective antigen. Individual immunity varied from undetectable to high

    A versatile computational pipeline for bacterial genome annotation improvement and comparative analysis, with Brucella as a use case

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    We present a bacterial genome computational analysis pipeline, called GenVar. The pipeline, based on the program GeneWise, is designed to analyze an annotated genome and automatically identify missed gene calls and sequence variants such as genes with disrupted reading frames (split genes) and those with insertions and deletions (indels). For a given genome to be analyzed, GenVar relies on a database containing closely related genomes (such as other species or strains) as well as a few additional reference genomes. GenVar also helps identify gene disruptions probably caused by sequencing errors. We exemplify GenVar's capabilities by presenting results from the analysis of four Brucella genomes. Brucella is an important human pathogen and zoonotic agent. The analysis revealed hundreds of missed gene calls, new split genes and indels, several of which are species specific and hence provide valuable clues to the understanding of the genome basis of Brucella pathogenicity and host specificity

    Morphological analysis of the sheathed flagellum of Brucella melitensis

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    <p>Abstract</p> <p>Background</p> <p>It was recently shown that <it>B. melitensis </it>is flagellated. However, the flagellar structure remains poorly described.</p> <p>Findings</p> <p>We analyzed the structure of the polar sheathed flagellum of <it>B. melitensis </it>by TEM analysis and demonstrated that the Ryu staining is a good method to quickly visualize the flagellum by optical microscopy. The TEM analysis demonstrated that an extension of the outer membrane surrounds a filament ending by a club-like structure. The Δ<it>ftcR</it>, Δ<it>fliF</it>, Δ<it>flgE </it>and Δ<it>fliC </it>flagellar mutants still produce an empty sheath.</p> <p>Conclusions</p> <p>Our results demonstrate that the flagellum of <it>B. melitensis </it>has the characteristics of the sheathed flagella. Our results also suggest that the flagellar sheath production is not directly linked to the flagellar structure assembly and is not regulated by the FtcR master regulator.</p
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