704 research outputs found

    Possible thermal metamorphism on the C, G, B, and F asteroids detected from their reflectance spectra in comparison with carbonaceous chondrites

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    Reflectance spectra (0.3-2.6μm) of the C, G, B, and F asteroids and carbonaceous chondrites are compared in detail. Mixing calculations of 13 carbonaceous chondrite powders including three unusual CI/CM meteorites are done to characterize reflectance spectra of the 23 C, G, B, and F asteroids. Similar calculations are done with Murchison (CM2) samples heated at 400-1000℃. Both of two sets of calculations show that the C, G, B, and F asteroids may contain a significant amount of thermally metamorphosed materials. Comparison of ultraviolet absorption strengths between 160 C, G, B, and F asteroids and 21 carbonaceous chondrite powders suggests that surface minerals of most of those asteroids are thermally metamorphosed at temperatures around 600-1000℃

    A gene cluster in Agrobacterium vitis homologous to polyketide synthase operons is associated with grape necrosis and hypersensitive response induction on tobacco

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    Here, we identify a cluster of eight genes on chromosome 2 of Agrobacterium vitis that is associated with the ability of the bacterium to cause a hypersensitive response on tobacco and a necrosis of grape shoot explants. Three of these genes share a high level of structural and sequence similarity to clusters of genes in other bacteria that encode the enzymes for biosynthesis of polyketides and long-chain polyunsaturated fatty acids. No similar gene clusters were discovered in sequenced genomes of other members of Rhizobiale

    Germany and the United States: Reliable Allies. But Disagreement on Russia, Global Leadership and Trade

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    This Pew Research Center report, in association with Bertelsmann Foundation, examines American and German attitudes toward each other and their respective geopolitical roles. This report is based on telephone surveys in the United States and Germany. In the U.S., interviews were conducted February 26 to March 1, 2015 among a national sample of 1,003 persons, 18 years of age or older. In Germany, interviews were conducted February 24-25, 2015 among a national sample of 963 persons, 18 years of age or older. For more details, see survey methods and topline results

    Mineralogy

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    The power of mineralogical analysis as a descriptive or predictive technique stems from the fact that only a few thousand minerals are known to occur in nature as compared to several hundred thousand inorganic compounds. Further, all of the known minerals have specific stability ranges in pressure, temperature, an composition. A specific knowledge of the mineralogy of a planets surface or interior therefore allows one to characterize the present or past conditions under which the minerals were formed or have existed. For the purposes of this paper, a slightly broader definition of mineralogy was adopted by including not only crystalline materials found on planetary surfaces, but also ices and classes that can benefit from in situ types of analyses. Both visual examination and the various spectroscopies available for robotic probes to planetary surfaces are discussed

    Vapour pressure deficit modulates hydraulic function and structure of tropical rainforests under nonlimiting soil water supply

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    Atmospheric conditions are expected to become warmer and drier in the future, but little is known about how evaporative demand influences forest structure and function independently from soil moisture availability, and how fast-response variables (such as canopy water potential and stomatal conductance) may mediate longer-term changes in forest structure and function in response to climate change. We used two tropical rainforest sites with different temperatures and vapour pressure deficits (VPD), but nonlimiting soil water supply, to assess the impact of evaporative demand on ecophysiological function and forest structure. Common species between sites allowed us to test the extent to which species composition, relative abundance and intraspecific variability contributed to site-level differences. The highest VPD site had lower midday canopy water potentials, canopy conductance (gc), annual transpiration, forest stature, and biomass, while the transpiration rate was less sensitive to changes in VPD; it also had different height–diameter allometry (accounting for 51% of the difference in biomass between sites) and higher plot-level wood density. Our findings suggest that increases in VPD, even in the absence of soil water limitation, influence fast-response variables, such as canopy water potentials and gc, potentially leading to longer-term changes in forest stature resulting in reductions in biomass

    Tobacco smoking changes during the first pre-vaccination phases of the COVID-19 pandemic: A systematic review and meta-analysis

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    Background: Globally, tobacco smoking remains the largest preventable cause of premature death. The COVID-19 pandemic has forced nations to take unprecedented measures, including ‘lockdowns’ that might impact tobacco smoking behaviour. We performed a systematic review and meta-analyses to assess smoking behaviour changes during the early pre-vaccination phases of the COVID-19 pandemic in 2020. Methods: We searched Medline/Embase/PsycINFO/BioRxiv/MedRxiv/SSRN databases (January–November 2020) for published and pre-print articles that reported specific smoking behaviour changes or intentions after the onset of the COVID-19 pandemic. We used random-effects models to pool prevalence ratios comparing the prevalence of smoking during and before the pandemic, and the prevalence of smoking behaviour changes during the pandemic. The PROSPERO registration number for this systematic review was CRD42020206383. Findings: 31 studies were included in meta-analyses, with smoking data for 269,164 participants across 24 countries. The proportion of people smoking during the pandemic was lower than that before, with a pooled prevalence ratio of 0·87 (95%CI:0·79–0·97). Among people who smoke, 21% (95%CI:14–30%) smoked less, 27% (95%CI:22–32%) smoked more, 50% (95%CI:41%-58%) had unchanged smoking and 4% (95%CI:1–9%) reported quitting smoking. Among people who did not smoke, 2% (95%CI:1–3%) started smoking during the pandemic. Heterogeneity was high in all meta-analyses and so the pooled estimates should be interpreted with caution (I2\u3e91% and p-heterogeneity\u3c0·001). Almost all studies were at high risk of bias due to use of non-representative samples, non-response bias, and utilisation of non-validated questions. Interpretation: Smoking behaviour changes during the first phases of the COVID-19 pandemic in 2020 were highly mixed. Meta-analyses indicated that there was a relative reduction in overall smoking prevalence during the pandemic, while similar proportions of people who smoke smoked more or smoked less, although heterogeneity was high. Implementation of evidence-based tobacco control policies and programs, including tobacco cessation services, have an important role in ensuring that the COVID-19 pandemic does not exacerbate the smoking pandemic and associated adverse health outcomes

    Safety of Ixekizumab Treatment for up to 5 Years in Adult Patients with Moderate-to-Severe Psoriasis : Results from Greater Than 17,000 Patient-Years of Exposure

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    Altres ajuts: The studies described herein and the Rapid Service Fee were funded by Eli Lilly and Company.Long-term safety data are critical for evaluating therapies for psoriasis. Ixekizumab has demonstrated efficacy and is well tolerated for the treatment of moderate-to-severe plaque psoriasis. We examined the safety and tolerability of up to 5 years of ixekizumab therapy in patients with psoriasis. Integrated safety data were analyzed from 13 ixekizumab clinical studies. Rates of treatment-emergent adverse events (TEAEs), serious AEs (SAEs) and AEs of special interest were analyzed for the 12-week induction period in the combined pivotal studies, and for all pooled studies by year(s) of therapy and overall, reported as exposure-adjusted incidence rates (IRs) per 100 patient-years (p-y) and/or frequencies. Total ixekizumab exposure was 17,003.4 p-y (N = 5898); 2749 patients had ≥ 4 years of exposure. When compared across years of exposure, rates for AEs remained largely stable or declined, including TEAEs leading to discontinuation (3.8/100 p-y in year 1, declining to 2.0/100 p-y in year 5); SAEs (range 6.2-7.0/100 p-y); serious infections (range 1.3-1.7/100 p-y); nonmelanoma skin cancer (ranging from 0.5/100 p-y in year 1 to 0.2/100 p-y in years 4-5); other malignancies (range 0.4-0.6/100 p-y); inflammatory bowel disease including ulcerative colitis and Crohn's disease (IR 0.2/100 p-y); and major adverse cardiovascular events (MACE) (range 0.3-0.7/100 p-y). Candidiasis was reported in 327 patients (IR 1.9/100 p-y), with the majority identified as mucocutaneous. The rate of injection site reactions was 15.5/100 p-y during year 1 and 2.0-2.3/100 p-y by years 3-5. The decrease in rates of TEAEs and the stable rates of SAEs, other malignancies and MACE during up to 5 years of ixekizumab dosing are consistent with previous reports describing a favorable safety profile of ixekizumab following shorter durations of exposure. Eli Lilly and Company
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