88 research outputs found

    Pinworms of the red howler monkey (Alouatta seniculus) in Colombia. Gathering the pieces of the pinworm-primate puzzle

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    Pinworms of primates are believed to be highly host specific parasites, forming co-evolutionary associations with their hosts. In order to assess the strength and reach of such evolutionary links, we need to have a broad understanding of the pinworm diversity associated with primates. Here, we employed an integrative taxonomic approach to assess pinworm diversity in red howler monkeys in Colombia. Molecular and morphological evidence validate the presence of at least four different species of Trypanoxyuris occurring in red howler monkeys: T. minutus, a widely distributed species, and three new species, T. seunimiii n. sp., T. kemuimae n. sp. and T. kotudoi n. sp. The mitochondrial COI gene and the 28S ribosomal gene were used for phylogenetic assessments through Bayesian inference. The three new species were morphologically distinct and formed reciprocally monophyletic lineages. Further molecular lineage subdivision in T. minutus and T. kotudoi n. sp. without morphological correspondence, suggests the potential scenario for the existence of cryptic species. Phylogenetic relationships imply that the different species of Trypanoxyuris occurring in each howler monkey species were acquired through independent colonization events. On-going efforts to uncover pinworm diversity will allow us to test the degree of host specificity and the co-phylogenetic hypothesis, as well as to further unravel the primate-pinworm evolutionary history puzzle

    Using Wavelets to reject background in Dark Matter experiments

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    A method based on wavelet techniques has been developed and applied to background rejection in the data of the IGEX dark matter experiment. The method is presented and described in some detail to show how it efficiently rejects events coming from noise and microphonism through a mathematical inspection of their recorded pulse shape. The result of the application of the method to the last data of IGEX is presented.Comment: 14 pages, 8 figures. Submitted to Astrop. Phy

    Status of IGEX dark matter search at Canfranc Underground Laboratory

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    One IGEX 76Ge double-beta decay detector is currently operating in the Canfranc Underground Laboratory in a search for dark matter WIMPs, through the Ge nuclear recoil produced by the WIMP elastic scattering. In this talk we report on the on-going efforts to understand and eventually reject the background at low energy. These efforts have led to the improvement of the neutron shielding and to partial reduction of the background, but still the remaining events are not totally identified. A tritium contamination or muon-induced neutrons are considered as possible sources, simulations and experimental test being still under progress. According to the success of this study we comment the prospects of the experiment as well as those of its future extension, the GEDEON dark matter experiment.Comment: 6 pages, 3 figures, talk given at 4th International Workshop on the Identification of Dark Matter, York, September 200

    The IGEX experiment revisited: a response to the critique of Klapdor-Kleingrothaus,Dietz, and Krivosheina

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    This paper is a response to the article "Critical View to" the IGEX neutrinoless double-beta decay experiment..."published in Phys. Rev.D, Volume 65 (2002) 092007," by H.V.Klapdor-Kleingrothaus, A. Dietz, and I.V.Krivosheina, published as preprint hep-ph/0403056. The criticisms are confronted, and the questions raised are answered. We demonstrate that the lower limit quoted by IGEX, for the half life of Ge-76 neutrinoless double beta decay, 1.57x10**25 y, is correct and that there was no "arithmetical error"-as claimed in the " Critical Review" article

    New 1-aryl-3-substituted propanol derivatives as antimalarial agents

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    This paper describes the synthesis and in vitro antimalarial activity against a P. falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of the tested compounds showed an IC50 lower than 1 μM. These compounds were also tested for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic option for the treatment of malaria

    A Novel Small Molecule Inhibitor of Influenza A Viruses that Targets Polymerase Function and Indirectly Induces Interferon

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    Influenza viruses continue to pose a major public health threat worldwide and options for antiviral therapy are limited by the emergence of drug-resistant virus strains. The antiviral cytokine, interferon (IFN) is an essential mediator of the innate immune response and influenza viruses, like many viruses, have evolved strategies to evade this response, resulting in increased replication and enhanced pathogenicity. A cell-based assay that monitors IFN production was developed and applied in a high-throughput compound screen to identify molecules that restore the IFN response to influenza virus infected cells. We report the identification of compound ASN2, which induces IFN only in the presence of influenza virus infection. ASN2 preferentially inhibits the growth of influenza A viruses, including the 1918 H1N1, 1968 H3N2 and 2009 H1N1 pandemic strains and avian H5N1 virus. In vivo, ASN2 partially protects mice challenged with a lethal dose of influenza A virus. Surprisingly, we found that the antiviral activity of ASN2 is not dependent on IFN production and signaling. Rather, its IFN-inducing property appears to be an indirect effect resulting from ASN2-mediated inhibition of viral polymerase function, and subsequent loss of the expression of the viral IFN antagonist, NS1. Moreover, we identified a single amino acid mutation at position 499 of the influenza virus PB1 protein that confers resistance to ASN2, suggesting that PB1 is the direct target. This two-pronged antiviral mechanism, consisting of direct inhibition of virus replication and simultaneous activation of the host innate immune response, is a unique property not previously described for any single antiviral molecule

    Measurement of isotopic separation of argon with the prototype of the cryogenic distillation plant Aria for dark matter searches

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    The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26 m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes: 36Ar , 38Ar , and 40Ar . We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
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