58 research outputs found

    Threat to Cedar, Cedrela odorata, Plantations in Vietnam by the Weevil, Aclees sp.

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    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enabled the life history to be determined. Eggs were laid (February to March, September to November) inside the bark from the base of the trunk up to 60 cm in height. Larvae formed extensive feeding tunnels in the inner bark and sap wood. Pupation occurred in feeding tunnels or pupal chambers in the sapwood. Adults emerged twice a year, February to March and August to October. It is concluded that Aclees is a threat to C. odorata plantations in tropical regions of the world, and quarantine measures should be implemented to reduce the risk of spread

    B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+

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    We report the first measurement of polarized thermal dust emission toward the entire infrared dark cloud G11.11−0.12 taken by the polarimeter SOFIA/HAWC+ at 214 ÎŒm. The obtained magnetic fields (B-fields) from the polarized emission of the early-stage and massive filament tend to be perpendicular to its spine. We produce a map of B-field strengths for the center region of the filament. The strengths vary in the range of 100–600 ÎŒG and are strongest along the filament's spine. The central region is sub-AlfvĂ©nic and mostly subcritical, meaning that B-fields dominate over turbulence and are strong enough to resist gravitational collapse. The alignment and properties of dust grains in the filament are studied using radiative torque (RAT) theory. We find the decrease of polarization degree P with emission intensity I, i.e., depolarization effect, of the form P∝ I−α ∌ 0.8–0.9, implying a significant loss of grain alignment in the filament's spine. The depolarization can be explained by the decrease in RAT alignment efficiency toward the denser regions with weaker radiation field, which cannot be explained by B-field tangling. We study the effect of the enhanced magnetic relaxation by embedded iron inclusions on RAT alignment and find that the high polarization fraction P ∌ 20%–30% in the outer layer of the filament is potential evidence for the magnetically enhanced RAT alignment mechanism. This is the first time this effect is evaluated in a filament. Based on the polarization fraction and RAT alignment theory, we also find evidence for grain growth in the filament

    The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-Filament Structure, Monoceros R2

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    We present and analyze observations of polarized dust emission at 850um towards the central 1 pc x 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the BISTRO (B-fields in Star-forming Region Observations) survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well-described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis-Chandrasekhar-Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3-2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 + 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 + 0.02. Additionally, the mean Alfv\'en Mach number is 0.35 + 0.01. This suggests that in Mon R2, magnetic fields provide resistance against large-scale gravitational collapse, and magnetic pressure exceeds turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically sub-critical

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    High cure rates for HCV genotype 6 in advanced liver fibrosis with 12 weeks sofosbuvir and daclatasvir: The Vietnam SEARCH Study

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    Background Genotype 6 is the most genetically diverse lineage of hepatitis C virus (HCV), and predominates in Vietnam. It can be treated with sofosbuvir with daclatasvir (SOF/DCV), the lowest costing treatment combination globally. In regional guidelines, longer treatment durations of SOF/DCV (24 weeks) are recommended for cirrhotic individuals, compared with other pangenotypic regimens (12 weeks), based on sparse data. Early on-treatment virological response may offer means of reducing length and cost of therapy in patients with liver fibrosis. Methods In this prospective trial in Vietnam, genotype 6-infected adults with advanced liver fibrosis or compensated cirrhosis were treated with SOF/DCV. Day 14 viral load was used to guide duration of therapy: participants with viral load <500 IU/ml at day 14 were treated with 12 weeks of SOF/DCV and those ≄500 IU/ml received 24 weeks. Primary endpoint was sustained virological response. Findings Of 41 individuals with advanced fibrosis or compensated cirrhosis who commenced treatment, 51% had genotype 6a, 34% 6e. The remainder had 6h, 6k, 6l or 6o. 100% had viral load <500 IU/ml by day 14, meaning all received 12 weeks of SOF/DCV. 100% achieved SVR12 despite a high frequency of putative NS5A inhibitor resistance-associated substitutions (RAS) at baseline. Interpretation 12 weeks of SOF/DCV achieves excellent cure rates in this population. This data supports the removal of costly genotyping in countries where genotype 3 prevalence in <5%, in keeping with WHO guidelines. NS5A-resistance associated mutations in isolation, do not affect efficacy of SOF/DCV therapy. Wider evaluation of response-guided therapy is warranted

    Nonannual seasonality of influenza-like illness in a tropical urban setting

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    Background In temperate and subtropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular. Methods To obtain a detailed picture of influenza-like illness (ILI) patterns in the tropics, we established an mHealth study in community clinics in Ho Chi Minh City (HCMC). During 2009-2015, clinics reported daily case numbers via SMS, with a subset performing molecular diagnostics for influenza virus. This real-time epidemiology network absorbs 6000 ILI reports annually, one or two orders of magnitude more than typical surveillance systems. A real-time online ILI indicator was developed to inform clinicians of the daily ILI activity in HCMC. Results From August 2009 to December 2015, 63 clinics were enrolled and 36 920 SMS reports were received, covering approximately 1.7M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong nonannual dynamics with a dominant periodicity of 206 days. This was confirmed by time series decomposition, stepwise regression, and a forecasting exercise showing that median forecasting errors are 30%‐40% lower when using a 206‐day cycle. In ILI patients from whom nasopharyngeal swabs were taken, 31.2% were positive for influenza. There was no correlation between the ILI time series and the time series of influenza, influenza A, or influenza B (all P &gt; 0.15). Conclusion This suggests, for the first time, that a nonannual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism.</p
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