3,409 research outputs found
Radio Polarisation Study of High Rotation Measure AGNs
As radio polarised emission from astrophysical objects traverse through
foreground magnetised plasma, the physical conditions along the lines of sight
are encrypted in the form of Rotation Measure (RM). We performed broadband
spectro-polarimetric observations of high Rotation Measure (|RM| >~ 300 rad
m-2) sources away from the Galactic plane (|b| > 10 deg) selected from the NVSS
RM catalogue. The main goals are to verify the NVSS RM values, which could be
susceptible to n{\pi}-ambiguity, as well as to identify the origin of the
extreme RM values. We show that 40 % of our sample suffer from n{\pi}-ambiguity
in the NVSS RM catalogue. There are also hints of RM variabilities over ~20
years epoch for most of our sources, as revealed by comparing the RM values of
the two studies in the same frequency ranges after correcting for
n{\pi}-ambiguity. At last, we demonstrate the possibility of applying
QU-fitting to study the ambient media of AGNs.Comment: 6 pages, 2 figures; Accepted by MDPI Galaxies; Conference Proceedings
for the Polarised Emission from Astrophysical Jets meeting on June 12-16
2017, Ierapetra, Greec
Spectrum of malignancies among the population of adults living with HIV infection in China: A nationwide follow-up study, 2008-2011.
BackgroundAlthough increasingly studied in high-income countries, there is a paucity of data from the Chinese population on the patterns of cancer among people living with HIV (PLHIV).MethodsWe conducted a nationwide follow-up study using routinely collected data for adult PLHIV diagnosed on or before 31 December 2011 and alive and in care as of 1 January 2008. Participants were observed from 1 January 2008 (study start) to 30 June 2012 (study end). Main outcome measures were gender-stratified age-standardized incidence rates for China (ASIRC) and standardized incidence ratios (SIR) for all malignancy types/sites observed.ResultsAmong 399,451 subjects, a majority was aged 30-44 years (49.3%), male (69.8%), and Han Chinese (67.9%). A total of 3,819 reports of cancer were identified. Overall, ASIRC was 776.4 per 100,000 for males and 486.5 per 100,000 for females. Malignancy sites/types with highest ASIRC among males were lung (226.0 per 100,000), liver (145.7 per 100,000), and lymphoma (63.1 per 100,000), and among females were lung (66.8 per 100,000), lymphoma (48.0 per 100,000), stomach (47.8 per 100,000), and cervix (47.6 per 100,000). Overall SIR for males was 3.4 and for females was 2.6. Highest SIR was observed for Kaposi sarcoma (2,639.8 for males, 1,593.5 for females) and lymphoma (13.9 for males, 16.0 for females).ConclusionsThese results provide evidence of substantial AIDS-defining and non-AIDS-defining cancer burden among adult Chinese PLHIV between 2008 and 2011. Although further study is warranted, China should take action to improve cancer screening, diagnosis, and treatment for this vulnerable population
In search of "Favorite-Long Shot Bias" : An experimental study of the demand for sweepstakes
This paper studies experimentally the demand for a variable-prize sweepstakes in which a single winner receives 90% of the total receipts, and whether such demand would exhibit the favorite-longshot bias (FLB) widely reported in the racetrack betting literature. We find significant incidence of sweepstakes purchase over population sizes ranging from 2 to 141, a greater tendency for FLB among those who exhibit longshot preference (LSP) over fixed-odds lotteries, but mixed support for FLB per se. In particular, the demand on average for 28-subject sweepstakes exceeds that of the largest one with 141 subjects including those who are averse to taking even-chance bets. Further and intriguingly, we observe significant demands for 2-person sweepstakes even among risk adverse subjects. Taken together, our observations reveal an incremental demand for sweepstakes arising from its interactive nature that can reinforce the effects of LSP as well as counter the effects of risk aversion.ArticleFaculty of Economics and Law Shinshu University Staff Paper Series. 1 : 1-52 (2016). (Staff Paper No.16-01).technical repor
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Overrepresentation of Injection Drug Use Route of Infection Among Human Immunodeficiency Virus Long-term Nonprogressors: A Nationwide, Retrospective Cohort Study in China, 1989-2016.
BackgroundWhy some persons living with human immunodeficiency virus (HIV) (PLWH) progress quickly and others remain "healthy" for a decade or more without treatment remains a fundamental question of HIV pathology. We aimed to assess the epidemiological characteristics of HIV long-term nonprogressors (LTNPs) based on a cohort of PLWH in China observed between 1989 and 2016.MethodsWe conducted a nationwide, retrospective cohort study among Chinese PLWH with HIV diagnosed before 1 January 2008. Records were extracted from China's national HIV/AIDS database on 30 June 2016. LTNPs were defined as those with AIDS-free, antiretroviral therapy-naive survival, with CD4 cell counts consistently ≥500/μL for ≥8 years after diagnosis. Prevalence was calculated, characteristics were described, and determinants were assessed by means of logistic regression. Potential sources of bias were also investigated.ResultsOur cohort included 89 201 participants, of whom 1749 (2.0%) were categorized as LTNPs. The injection drug use (IDU) route of infection was reported by 70.7% of LTNPs, compared with only 37.1% of non-LTNPs. The odds of LTNP status were greater among those infected via IDU (adjusted odds ratio [95% confidence interval], 2.28 [1.94-2.68]) and with HIV diagnosed in settings with large populations of persons who inject drugs (1.75 [1.51-2.02] for detention centers, 1.61 [1.39-1.87] for Yunnan, 1.94 [1.62-2.31] for Guangdong, and 2.90 [2.09-4.02] for Xinjiang).ConclusionsOverrepresentation of the IDU route of infection among LTNPs is a surprising finding worthy of further study, and this newly defined cohort may be particularly well suited to exploration of the molecular biological mechanisms underlying HIV long-term nonprogression
Long-Term Litter Decomposition Controlled by Manganese Redox Cycling
Litter decomposition is a keystone ecosystem process impacting nutrient cycling and productivity, soil properties, and the terrestrial carbon (C) balance, but the factors regulating decomposition rate are still poorly understood. Traditional models assume that the rate is controlled by litter quality, relying on parameters such as lignin content as predictors. However, a strong correlation has been observed between the manganese (Mn) content of litter and decomposition rates across a variety of forest ecosystems. Here, we show that long-term litter decomposition in forest ecosystems is tightly coupled to Mn redox cycling. Over 7 years of litter decomposition, microbial transformation of litter was paralleled by variations in Mn oxidation state and concentration. A detailed chemical imaging analysis of the litter revealed that fungi recruit and redistribute unreactive Mn2+ provided by fresh plant litter to produce oxidative Mn3+ species at sites of active decay, with Mn eventually accumulating as insoluble Mn3+/4+ oxides. Formation of reactive Mn3+ species coincided with the generation of aromatic oxidation products, providing direct proof of the previously posited role of Mn3+-based oxidizers in the breakdown of litter. Our results suggest that the litter-decomposing machinery at our coniferous forest site depends on the ability of plants and microbes to supply, accumulate, and regenerate short-lived Mn3+ species in the litter layer. This observation indicates that biogeochemical constraints on bioavailability, mobility, and reactivity of Mn in the plant–soil system may have a profound impact on litter decomposition rates
A Review of Applicable Materials for 3D Printing a Biomechanically Accurate Cervical Spine Model for Surgical Education & Case Preparation
Objectives: The authors review the literature to compare biomechanical properties of the human cervical spine as determined by cadaveric and finite elemental model (FEM) studies, with commercially available three-dimensional (3D) printing materials to aid in the development of 3D-printed cervical spines that can be used as biomechanically accurate educational tools. Specifically, 3D printing materials for fused deposition modeling (FDM) printers were explored.
Methods: A literature review of biomechanical specifications such as Young’s Modulus and Poisson’s ratio of certain anatomical aspects of the cervical spine was performed by searching the databases PubMed, MEDLINE via Ovid, Wolters Kluwer, ClinicalKey, and EMBASE via Elsevier for keywords. The anatomical features that were investigated included cortical and cancellous bone, facet joints, intervertebral discs, and ligaments. Additionally, datasheets from companies Stratasys, Fillamentum, NinjaTek, SD3D, Polymakers, Lubrizol and BASF were compiled to review the specifications and mechanical properties of their 3D printing materials.
Results: Suggested FDM 3D printing materials were assigned to anatomical features of the cervical spine according to their respective biomechanical properties, namely: cortical and cancellous bone, facet joint articular cartilage and the synovial membrane, both the ground substance and fibers of the annulus fibrosus, nucleus pulposus, anterior and posterior longitudinal ligaments, ligamenta flava, interspinous ligaments, and capsular ligaments.
Conclusions: FDM 3D printing can improve development of cervical spine models for educational use and surgical case preparation. Commercially available materials and techniques exist to simulate all of the major anatomical components of the cervical spine
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