62 research outputs found
Dense Antihydrogen: Its Production and Storage to Envision Antimatter Propulsion
We discuss the possibility that dense antihydrogen could provide a path
towards a mechanism for a deep space propulsion system. We concentrate at
first, as an example, on Bose-Einstein Condensate (BEC) antihydrogen. In a
Bose-Einstein Condensate, matter (or antimatter) is in a coherent state
analogous to photons in a laser beam, and individual atoms lose their
independent identity. This allows many atoms to be stored in a small volume. In
the context of recent advances in producing and controlling BECs, as well as in
making antihydrogen, this could potentially provide a revolutionary path
towards the efficient storage of large quantities of antimatter, perhaps
eventually as a cluster or solid.Comment: 12 pages, 3 figure
Determinants of short and long term functional recovery after hospitalization for community-acquired pneumonia in the elderly: role of inflammatory markers
BACKGROUND: Hospitalization for older patients with community-acquired pneumonia (CAP) is associated with functional decline. Little is know about the relationship between inflammatory markers and determinants of functional status in this population. The aim of the study is to investigate the association between tumor necrosis factor (TNF)-α, C-reactive protein (CRP) and Activities of Daily Living, and to identify risk factors associated with one year mortality or hospital readmission. METHODS: 301 consecutive patients hospitalized for CAP (mean age 73.9 ± 5.3 years) in a University affiliated hospital over 18 month period were included. All patients were evaluated on admission to identify baseline demographic, microbiological, cognitive and functional characteristics. Serum levels for TNF-α and CRP were collected at the same time. Reassessment of functional status at discharge, and monthly thereafter till 3 months post discharge was obtained and compared with preadmission level to document loss or recovery of functionality. Outcome was assessed by the composite endpoint of hospital readmission or death from any cause up to one year post hospital discharge. RESULTS: 36% of patients developed functional decline at discharge and 11% had persistent functional impairment at 3 months. Serum TNF-α (odds ratio [OR] 1.12, 95% CI 1.08–1.15; p < 0.001) and the Charlson Index (OR = 1.39, 95% CI 1.14 to 1.71; p = 0.001) but not age, CRP, or cognitive status were independently associated with loss of functionality at the time of hospital discharge. Lack of recovery in functional status at 3 months was associated with impaired cognitive ability and preadmission comorbidities. In Cox regression analysis, persistent functional impairment at 3 months, impaired cognitive function, and the Charlson Index were highly predictive of one year hospital readmission or death. CONCLUSION: Serum TNF-α levels can be useful in determining patients at risk for functional impairment following hospitalization from CAP. Old patients with impaired cognitive function and preexisting comorbidities who exhibit delay in functional recovery at 3 months post discharge may be at high risk for hospital readmission and death. With the scarcity of resources, a future risk stratification system based on these findings might be proven helpful to target older patients who are likely to benefit from interventional strategies
Nothing New in the (North) East? Interpreting the Rhetoric and Reality of Japanese Corporate Governance
Japan finally seems to be pulling itself out of its lost decade (and a half) of economic stagnation. Some grudgingly or triumphantly attribute this to micro-economic reforms, freeing up arthritic markets, although there is also evidence that macro-economic policy failures have been a major cause of poor performance since the 1990s. Many point to overlapping transformations in corporate governance, broadly defined to cover relationships among managers and employees as well as between firms and outside shareholders, creditors, and other stakeholders. These relationships are in flux, with moves arguably favouring shareholders and more market-driven control mechanisms. It has certainly been a found decade for law reform in Japan, particularly in corporate law, with a plethora of legislative amendments commencing around 1993 and culminating in the enactment of a consolidated Company Law in 2005. This modernisation project, particularly since 2001, is reportedly aimed at (i) securing better corporate governance, (ii) bringing the law into line with a highly-developed information society, (iii) liberalising fundraising measures, (iv) bringing corporate law into line with the internationalization of corporate activity, and (v) modernizing terms and consolidating corporate law. Because the suite of revisions has moved away from strict mandatory rules set out originally in Japan\u27s Commercial Code of 1899, modeled primarily on German law, another growing perception is that Japanese corporate law and practice is or will soon be converging significantly on US models. However, assessments remain divided as to whether these moves in corporate governance and capitalism more generally in Japan amount to a new paradigm or regime shift . Focusing primarily on quite influential commentary in English, Part I of this paper outlines two pairs of views. It concludes that the most plausible assessment is of significant but gradual transformation towards a more market-driven approach, evident also in other advanced political economies. Drawing more generally from these often virulently divided views, Part II sets out five ways forward through the proliferating literature and source material on corporate governance in Japan. Particular care must be taken in: (i) selecting the temporal timeframe, (ii) selecting countries to compare, (iii) balancing black-letter law and broader socio-economic context, (iv) reflecting on and disclosing normative preferences, and (v) giving weight to processes as well as outcomes, when assessing change in Japan - and any other country\u27s governance system. Part III ends with a call for further research particularly on law- and policy-producing processes, rather than mainly outcomes. It also outlines the usefulness of this analytical framework for analysing the broader field of Corporate Social Responsibility, now emerging as the next major area of debate and transformation in Japan - as elsewhere
Measurements of the W production cross sections in association with jets with the ATLAS detector
This paper presents cross sections for the production of a W boson in association with jets, measured in proton–proton collisions at √s=7 TeV with the ATLAS experiment at the large hadron collider. With an integrated luminosity of 4.6 fb−1, this data set allows for an exploration of a large kinematic range, including jet production up to a transverse momentum of 1 TeV and multiplicities up to seven associated jets. The production cross sections for W bosons are measured in both the electron and muon decay channels. Differential cross sections for many observables are also presented including measurements of the jet observables such as the rapidities and the transverse momenta as well as measurements of event observables such as the scalar sums of the transverse momenta of the jets. The measurements are compared to numerous QCD predictions including next-to-leading-order perturbative calculations, resummation calculations and Monte Carlo generators
Suicide risk in schizophrenia: learning from the past to change the future
Suicide is a major cause of death among patients with schizophrenia. Research indicates that at least 5–13% of schizophrenic patients die by suicide, and it is likely that the higher end of range is the most accurate estimate. There is almost total agreement that the schizophrenic patient who is more likely to commit suicide is young, male, white and never married, with good premorbid function, post-psychotic depression and a history of substance abuse and suicide attempts. Hopelessness, social isolation, hospitalization, deteriorating health after a high level of premorbid functioning, recent loss or rejection, limited external support, and family stress or instability are risk factors for suicide in patients with schizophrenia. Suicidal schizophrenics usually fear further mental deterioration, and they experience either excessive treatment dependence or loss of faith in treatment. Awareness of illness has been reported as a major issue among suicidal schizophrenic patients, yet some researchers argue that insight into the illness does not increase suicide risk. Protective factors play also an important role in assessing suicide risk and should also be carefully evaluated. The neurobiological perspective offers a new approach for understanding self-destructive behavior among patients with schizophrenia and may improve the accuracy of screening schizophrenics for suicide. Although, there is general consensus on the risk factors, accurate knowledge as well as early recognition of patients at risk is still lacking in everyday clinical practice. Better knowledge may help clinicians and caretakers to implement preventive measures. This review paper is the results of a joint effort between researchers in the field of suicide in schizophrenia. Each expert provided a brief essay on one specific aspect of the problem. This is the first attempt to present a consensus report as well as the development of a set of guidelines for reducing suicide risk among schizophenia patients
Abdominal aortic aneurysm is associated with a variant in low-density lipoprotein receptor-related protein 1
Abdominal aortic aneurysm (AAA) is a common cause of morbidity and mortality and has a significant heritability. We carried out a genome-wide association discovery study of 1866 patients with AAA and 5435 controls and replication of promising signals (lead SNP with a p value < 1 × 10-5) in 2871 additional cases and 32,687 controls and performed further follow-up in 1491 AAA and 11,060 controls. In the discovery study, nine loci demonstrated association with AAA (p < 1 × 10-5). In the replication sample, the lead SNP at one of these loci, rs1466535, located within intron 1 of low-density-lipoprotein receptor-related protein 1 (LRP1) demonstrated significant association (p = 0.0042). We confirmed the association of rs1466535 and AAA in our follow-up study (p = 0.035). In a combined analysis (6228 AAA and 49182 controls), rs1466535 had a consistent effect size and direction in all sample sets (combined p = 4.52 × 10-10, odds ratio 1.15 [1.10-1.21]). No associations were seen for either rs1466535 or the 12q13.3 locus in independent association studies of coronary artery disease, blood pressure, diabetes, or hyperlipidaemia, suggesting that this locus is specific to AAA. Gene-expression studies demonstrated a trend toward increased LRP1 expression for the rs1466535 CC genotype in arterial tissues; there was a significant (p = 0.029) 1.19-fold (1.04-1.36) increase in LRP1 expression in CC homozygotes compared to TT homozygotes in aortic adventitia. Functional studies demonstrated that rs1466535 might alter a SREBP-1 binding site and influence enhancer activity at the locus. In conclusion, this study has identified a biologically plausible genetic variant associated specifically with AAA, and we suggest that this variant has a possible functional role in LRP1 expression
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.
OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis
Search for new phenomena in events with three or more charged leptons in collisions at TeV with the ATLAS detector
A generic search for anomalous production of events with at least three
charged leptons is presented. The data sample consists of collisions at
TeV collected in 2012 by the ATLAS experiment at the CERN Large
Hadron Collider, and corresponds to an integrated luminosity of 20.3 fb.
Events are required to have at least three selected lepton candidates, at least
two of which must be electrons or muons, while the third may be a hadronically
decaying tau. Selected events are categorized based on their lepton flavour
content and signal regions are constructed using several kinematic variables of
interest. No significant deviations from Standard Model predictions are
observed. Model-independent upper limits on contributions from beyond the
Standard Model phenomena are provided for each signal region, along with
prescription to re-interpret the limits for any model. Constraints are also
placed on models predicting doubly charged Higgs bosons and excited leptons.
For doubly charged Higgs bosons decaying to or , lower limits
on the mass are set at 400 GeV at 95% confidence level. For excited leptons,
constraints are provided as functions of both the mass of the excited state and
the compositeness scale , with the strongest mass constraints arising
in regions where the mass equals . In such scenarios, lower mass
limits are set at 3.0 TeV for excited electrons and muons, 2.5 TeV for excited
taus, and 1.6 TeV for every excited-neutrino flavour.Comment: 442 pages plus author list + cover pages (60 pages total), 6 figures,
25 tables, submitted to JHEP, All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2012-20
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