1,461 research outputs found
How Large is the Bias is Self-Reported Disability?
A pervasive concern with the use of self-reported health and disability measures in behavioral models is that they are biased and endogenous. A commonly suggested explanation is that survey respondents exaggerate the severity of health problems and incidence of disabilities in order to rationalize labor force non-participation, application for disability benefits and/or receipt of those benefits. This paper re-examines this issue using a self-reported indicator of disability status from the Health and Retirement Survey. Using a bivariate probit model we test and are unable to reject the hypothesis that the self-reported disability measure is an exogenous explanatory variable in a model of individual's decision to apply for DI benefits or Social Security Administration's decision to award benefits. We further study a subsample of individuals who applied for Disability Insurance and Supplemental Security Income benefits from the Social Security Administration (SSA) for whom we can also observe SSA's award/deny decision. For this subsample we test and are unable to reject the hypothesis that self-reported disability is health and socio-economic characteristics similar to the information used by the SSA in making its award decisions. The unbiasedness restriction implies that these two variables have the same conditional probability distributions. Thus, our results indicate that disability applicant do not exaggerate their disability status at least in anonymous surveys such as the HRS. Indeed, our results are consistent with the hypothesis that disability applicants are aware of the criteria and decision rules that SSA uses in making awards and act as if they were applying these same criteria and rules when reporting their own disability status.
Product numerical range in a space with tensor product structure
We study operators acting on a tensor product Hilbert space and investigate
their product numerical range, product numerical radius and separable numerical
range. Concrete bounds for the product numerical range for Hermitian operators
are derived. Product numerical range of a non-Hermitian operator forms a subset
of the standard numerical range containing the barycenter of the spectrum.
While the latter set is convex, the product range needs not to be convex nor
simply connected. The product numerical range of a tensor product is equal to
the Minkowski product of numerical ranges of individual factors.Comment: 17 pages, 4 figures. Original preprint "Local numerical range: a
versatile tool in the theory of quantum information" [arXiv:0905.3646v1] was
broadened and split into two papers: "Restricted numerical range: a versatile
tool in the theory of quantum information", and "Product numerical range in a
space with tensor product structure
Association of chronic kidney disease with outcomes in acute stroke
Previous studies have found an association between chronic kidney disease and poor outcomes in stroke patients. However, there is a paucity of literature evaluating this association by stroke type. We therefore aimed to explore the association between CKD and stroke outcomes according to type of stroke. The data consisting of 594,681 stroke patients were acquired from Universal Coverage Health Security Insurance Scheme Database in Thailand. Binary logistic regression was used to assess the relationship of CKD and outcomes, which were as follows; in-hospital mortality, long length of stay (>3 days), pneumonia, sepsis, respiratory failure and myocardial infarction. Results: after fully adjusting for covariates, CKD was associated with increased odds of in-hospital mortality in patients with ischemic (OR 1.32; 95% CI = 1.27–1.38), haemorrhagic (OR 1.31; 95% CI = 1.24–1.39), and other undetermined stroke type (OR 1.44; 95% CI = 1.21–1.73). CKD was found to be associated with increased odds of pneumonia, sepsis, respiratory failure and myocardial infarction in ischaemic stroke. While CKD was found to be associated with increase odds of sepsis, respiratory failure, and myocardial infarction, decrease odds of pneumonia was observed in patients with haemorrhagic stroke. In other undetermined stroke type, CKD was found to only be associated with increase odds of sepsis and respiratory failure, while there is no significant association of CKD and increase or decrease odds with pneumonia and myocardial infarction. CKD was associated with poor outcomes in all stroke types. CKD should be considered as part of stroke prognosis as well as identifying at risk patient population for in-hospital complications
Determinants of Length of Stay Following Total Anterior Circulatory Stroke
Identification of factors that determine length of stay (LOS) in total anterior circulatory stroke (TACS) has potential for targeted intervention to reduce the associated health care burden. This study aimed to determine which factors predict LOS following either ischaemic or haemorrhagic TACS. The study sample population was drawn from the Norfolk and Norwich Stroke and Transient Ischemic Attack (TIA) Register (1996 – 2012), a prospective registry. 2965 patients admitted with TACS verified by a stroke specialist team were included. Primary analysis identified predictors of length of stay (LOS) in either haemorrhagic or ischaemic TACS. Secondary analyses identified predictors of LOS in patients who were discharged alive or who died during admission separately. Moderate (p=0.014) to severe disability (p=0.015) and history of congestive heart failure (p=0.027) in the primary analysis and pre-stroke residence in a care facility among patients who survived to discharge (p=0.013) were associated with a shorter length of stay. Factors associated with increased length of stay included presence of neurological lateralisation in the primary analysis (p=0.004) and amongst patients who died (p=0.003 and p=0.014 for ischaemic and haemorrhagic stroke, respectively). Patients with advanced age (≥85 years) with haemorrhagic stroke had longer LOS regardless of mortality outcome. Patients with low pre-morbid disability (modified Rankin score ≤2 who died following haemorrhagic TACS also had longer LOS. Our study found predictors of LOS following TACS include neurological lateralisation, pre-stroke disability status, congestive heart failure, pre-morbid residence and age. The identification of such factors would assist in resource allocation and discharge planning
In vitro and in vivo performance of methacrylated gellan gum hydrogel formulations for cartilage repair
Methacrylated gellan gum (GGMA) formulation is proposed as a second-generation hydrogel for controlled delivery of cartilage-forming cells into focal chondral lesions, allowing immediate in situ retention of cells and 3D filling of lesion volume, such approach deemed compatible with an arthroscopic procedure. Formulation optimization was carried out in vitro using chondrocytes and adipose mesenchymal stromal/stem cells (ASCs). A proof-of-concept in vivo study was conducted using a rabbit model with induced chondral lesions. Outcomes were compared with microfracture or non-treated control. Three grading scores were used to evaluate tissue repair after 8 weeks by macroscopic, histological and immunohistochemical analysis. Intense collagen type II and low collagen type I gene and protein expression were achieved in vitro by the ASC + GGMA formulation, in light with development of healthy chondral tissue. In vivo, this formulation promoted significantly superior de novo cartilage formation compared with the non-treated group. Maintenance of chondral height and integration with native tissue was further accomplished. The physicochemical properties of the proposed GGMA hydrogel exhibited highly favorable characteristics and biological performance both in vitro and in vivo, positioning itself as an attractive xeno-free biomaterial to be used with chondrogenic cells for a cost-effective treatment of focal chondral lesions. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1987-1996, 2018.Contract grant sponsor: Portuguese National Innovation Agency; contract grant number: QREN-13/SI/2011-23189info:eu-repo/semantics/publishedVersio
Renal Denervation Reduces Pulmonary Vascular Remodeling and Right Ventricular Diastolic Stiffness in Experimental Pulmonary Hypertension
Neurohormonal overactivation plays an important role in pulmonary hypertension (PH). In this context, renal denervation, which aims to inhibit the neurohormonal systems, may be a promising adjunct therapy in PH. In this proof-of-concept study, we have demonstrated in 2 experimental models of PH that renal denervation delayed disease progression, reduced pulmonary vascular remodeling, lowered right ventricular afterload, and decreased right ventricular diastolic stiffness, most likely by suppression of the renin-angiotensin-aldosterone system
Boro-nitriding coating on pure iron by powder-pack boriding and nitriding processes
To alleviate spallation and crack difficulties exhibited by a borided metallic surface when it is subjected to a normal, heavy and sliding load under dry conditions, a boron nitride coating was produced on pure iron in two stages: boriding the iron surface at 950 °C for 6 h and then nitriding the pre-borided iron at 550 °C for 6 h. The powder-pack technique was used in both stages. XRD measurements confirmed that the grown layers were nitrides and duplex borides. The produced diffusion of the layers reached 240 µm in depth as measured by SEM images. The measured microhardness across the case favoured the interphase cohesion between the iron nitrides and iron borides layers. Consequently, the multicomponent coating exhibited superior wear resistance to an applied normal load under dry sliding contact conditions in comparison to borided iron
AVALIAÇÃO DO ÓLEO DE CANOLA PARA PRODUÇÃO DE BIODIESEL / EVALUATION OF CANOLA OIL FOR BIODIESEL PRODUCTION
A crescente conscientização acerca dos impactos da poluição gerada por combustíveisfósseis, levou países de todo o mundo a repensarem o modo de como se utilizar energia. Em 2015 notratado de Paris durante a COP21 o Brasil assinou junto com mais 196 o termo de redução de CO 2 naatmosfera. E como uma das soluções para combustível renovável o óleo de canola é uma alternativa.O óleo é obtido das sementes das variedades de Brassica sp., e é amplamente utilizado paraalimentação humana, para lubrificação de maquinário industrial e para a produção de biodiesel. Oobjetivo deste estudo foi avaliar o processo de prensagem mecânica de grãos de canola em diferentestemperaturas e velocidades de rotação em uma extrusora mecânica com automação. O trabalho foidesenvolvido no laboratório da CTA, em uma prensa extrusora de grãos Z-1500. Para o presenteestudo foram definidas 4 temperaturas (110–120 °C, 120–30 °C, 130–140 °C e 140–50 °C) e 5velocidades [1000, 1200, 1400, 1600 e 1800 RPM (Rotações por minuto). Foi empregado um designexperimental 4 × 5 fatorial para determinar o rendimento de extração de óleo, massa específica do óleoe teor de proteínas na massa bromatológic
Bifosfonatos (BFs) como transportadores osteotrópicos no planejamento de fármacos dirigidos
Latenciação e formas avançadas de transporte de fármacos
O processo de modificação molecular denominado latenciação é revisto, apresentando formas avançadas no transporte de fármacos, utilizando macromoléculas como transportadores e sistemas de liberação sítio-específica como: CDS (Chemical Delivery System), ADEPT (Antibody-Directed Enzyme Prodrug Therapy), GDEPT/VDEPT (Gene-Directed Enzyme Prodrug Therapy/Vírus-Directed Enzyme Prodrug Therapy), ODDS (Osteotropic Drug Delivery System), PDEPT (Polymer-Directed Enzyme Prodrug Therapy), PELT (Polymer-Enzyme Liposome Therapy) e LEAPT (Lectin-Directed Enzyme-Activated Prodrug Therapy).This is a review about the molecular modification process, called latentiation, or prodrug design, focusing the progress in the prodrug approach using macromolecules as carriers and drug target systems as: PDEPT ( Polymer-Directed Enzyme Prodrug Therapy); PELT (Polymer-Enzyme Liposome Therapy); CDS (Chemical Delivery System); ADEPT(Antibody-Directed Enzyme Prodrug Therapy; GDEPT/VDEPT (Gene-Directed Enzyme Prodrug Therapy/Virus-Directed Enzyme Prodrug Therapy and ODDS (Osteotropic Drug Delivery System) and LEAPT (Lectin-Directed Enzyme-Activated Prodrug Therapy)
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