5,128 research outputs found
An airfoil for general aviation applications
A new airfoil, the NLF(1)-0115, has been recently designed at the NASA Langley Research Center for use in general-aviation applications. During the development of this airfoil, special emphasis was placed on experiences and observations gleaned from other successful general-aviation airfoils. For example, the flight lift-coefficient range is the same as that of the turbulent-flow NACA 23015 airfoil. Also, although beneficial for reducing drag and having large amounts of lift, the NLF(1)-0115 avoids the use of aft loading which can lead to large stick forces if utilized on portions of the wing having ailerons. Furthermore, not using aft loading eliminates the concern that the high pitching-moment coefficient generated by such airfoils can result in large trim drags if cruise flaps are not employed. The NASA NLF(1)-0115 has a thickness of 15 percent. It is designed primarily for general-aviation aircraft with wing loadings of 718 to 958 N/sq m (15 to 20 lb/sq ft). Low profile drag as a result of laminar flow is obtained over the range from c sub l = 0.1 and R = 9x10(exp 6) (the cruise condition) to c sub l = 0.6 and R = 4 x 10(exp 6) (the climb condition). While this airfoil can be used with flaps, it is designed to achieve c(sub l, max) = 1.5 at R = 2.6 x 10(exp 6) without flaps. The zero-lift pitching moment is held at c sub m sub o = 0.055. The hinge moment for a .20c aileron is fixed at a value equal to that of the NACA 63 sub 2-215 airfoil, c sub h = 0.00216. The loss in c (sub l, max) due to leading edge roughness, rain, or insects at R = 2.6 x 10 (exp 6) is 11 percent as compared with 14 percent for the NACA 23015
LEADING COMMENT: Children of lesbian mothers: From the 1970s to the new millennium
In both the popular and academic media, lesbian and gay parenting is the issue of the moment. Recent examples include the case of two gay men fathering twins with a surrogate mother in the US; the results of a study of gay fathers by Gill Dunne at the London School of Economics (Guardian, January 12, 2000); and comments from Dame Elizabeth Butler-Sloss, President of the Family Court, on the appropriateness of lesbian women and gay men as adoptive or foster parents (Guardian, October 16, 1999). These examples show that current debates focus on gay fathers, assisted reproduction and fostering/adoption. Does this mean that the concerns first raised in child custody disputes in the 1970's - that children raised in lesbian mother families would be at risk for psychological problems and atypical gender development – have been laid to rest? Psychological problems Concerns about the psychological well-being of children of lesbian mothers were based on the widely accepted view that some childhood experiences carry a risk of psychiatric disorder. This is predominately an argument about social acceptance; because lesbianism is not socially acceptable, the children of lesbian mothers will experience social disapproval. Thus, they will be likely to experience teasing and bullying by peers, which in turn may cause them to become socially withdrawn. Ultimately, it has been argued, the child will be unable to form and maintain friendships, an ability that has been shown to be important for self-esteem and psychological well-being in later life
The Direction of Research and Management of Double-crested Cormorants Heading into the 2000s: Symposium Overview and Future Information Needs
An overview is provided of a symposium on the direction of research and management of Doublecrested Cormorants (Phalacrocorax auritus) heading into the 2000s. The current symposium built on previous efforts and described a number of focus areas of informational need, including cormorant impacts on natural resources, demographics of cormorants, assessment of control efforts, assessment of fish consumption and bioenergetics, and cormorant spatial ecology and influences on movements. The cormorant symposium highlighted a shift in research focus relative to earlier symposia, from evaluating potential impacts on commercial and natural resources to evaluating management actions in attaining desired goals. In addition, the symposium addressed the pressing need to obtain baseline information on cormorant population demographics. The shift reflects a response to increasing management efforts and intensity in North America and the need to understand the effects and effectiveness of increased cormorant control at several spatial scales. The symposium furthered communication and the sharing of information on cormorant issues in North America. However, uncertainty regarding impacts to cormorants associated with policy changes and management actions and outcomes presents significant future challenges
Toilet talk: (Trans)Gendered negotiation of public spaces
Public toilet provision in the UK fails to meet the needs of cis women while trans communities are absent from current building regulations. This research explores how individuals negotiate differing positions on toilet provision and accessibility. The data was formed of online posts on Dezeen, a forum for building design professionals, and Mumsnet, a parenting forum, in response to the Ministry of Housing and Local Government ‘Technical review on increasing accessibility and provision of toilets for men and women’. Discursive Psychology was used to explore how accessibility to toilets is constructed. There is also an opportunity to explore how a discursive approach can be applied interdisciplinary with town planning and the built environment. Gender identities are situated and constructed within public toilets. Talk about refuge in public bathrooms involved the negotiation of who belonged in differing gender categories and who warranted a need for refuge. Where men are explicitly acknowledged as an issue, cis and trans women are collectively identified as requiring a safe space. Cis women are presented as a threat to trans women and other cis women who are misgendered. Discourse about toilet provision draws upon both heteronormative ideology to challenge access to trans people and others who challenge normative gender roles. Talk about toilets involves warranting ‘place-identity’ as gender identity is situated and access limited to those who are constructed as belonging
A systematic review of the individual determinants of research evidence use in allied health
Background: The use of evidence-based practice (EBP) is often not reflected in allied health (AH) practitioners’ day-to-day practice (the research-practice gap). Research suggests that considerable differences between and within AH disciplines exist, which require different approaches in order to influence practice behavior. It is therefore important to develop a better understanding of what influences individual AH practitioners’ adoption of evidence into daily practice. Objective: This systematic review aims to examine the individual characteristics of AH practitioners which determine their uptake of evidence into practice. Methods: Studies which examined individual factors or variables that influence research evidence use by any AH practitioner were included in the review. The methodological quality of the included papers was assessed using the Quality Assessment and Validity Tool for Cross-sectional Studies. A narrative summary of the findings was presented. Results: Six studies were included and the methodological quality scores indicated that two were weak and the remainder had moderate–weak quality. The review demonstrated that factors such as educational degree or academic qualification, involvement in research or EBP-related activities, and practitioners’ perceptions, attitudes and beliefs about research and EBP are significant predictors of self-reported research evidence use in AH. The effect of other factors such as professional characteristics, clinical setting/work environment, information-seeking behavior and sociodemographic variables are less clear. Whether there is an interaction effect between evidence-uptake factors has not been tested. Conclusion: Improving the research knowledge of clinicians and overcoming negative attitudes toward EBP have the potential to move AH practitioners towards regularly utilizing evidence in practice. Allied health practitioners may benefit from participation in regular educational opportunities such as case studies or journal clubs which can put them at the same level of thinking and awareness of research evidence. Future research should aim to review organizational and contextual factors and explore their interaction with individual determinants of research evidence use.L Lizarondo, K Grimmer-Somers, S Kuma
Functional correlates of optic flow motion processing in Parkinson’s disease
The visual input created by the relative motion between an individual and the environment, also called optic flow, influences the sense of self-motion, postural orientation, veering of gait, and visuospatial cognition. An optic flow network comprising visual motion areas V6, V3A, and MT+, as well as visuo-vestibular areas including posterior insula vestibular cortex (PIVC) and cingulate sulcus visual area (CSv), has been described as uniquely selective for parsing egomotion depth cues in humans. Individuals with Parkinson’s disease (PD) have known behavioral deficits in optic flow perception and visuospatial cognition compared to age- and education-matched control adults (MC). The present study used functional magnetic resonance imaging (fMRI) to investigate neural correlates related to impaired optic flow perception in PD. We conducted fMRI on 40 non-demented participants (23 PD and 17 MC) during passive viewing of simulated optic flow motion and random motion. We hypothesized that compared to the MC group, PD participants would show abnormal neural activity in regions comprising this optic flow network. MC participants showed robust activation across all regions in the optic flow network, consistent with studies in young adults, suggesting intact optic flow perception at the neural level in healthy aging. PD participants showed diminished activity compared to MC particularly within visual motion area MT+ and the visuo-vestibular region CSv. Further, activation in visuo-vestibular region CSv was associated with disease severity. These findings suggest that behavioral reports of impaired optic flow perception and visuospatial performance may be a result of impaired neural processing within visual motion and visuo-vestibular regions in PD.Published versio
Molecular marker analysis of Lr34 in Canada Western Red Spring wheat cultivars
Trabalho final de mestrado integrado em Medicina (Medicina Interna-Nutrição ClÃnica), apresentado à Faculdade de Medicina da Universidade de CoimbraO Carcinoma Colorretal é uma neoplasia frequente, particularmente nos PaÃses Ocidentais, tendo-se observado um aumento na sua incidência em Portugal nos últimos 30 anos. Pensa-se que para este aumento tenha contribuÃdo decisivamente a progressiva mudança do estilo de vida, particularmente no que diz respeito à alimentação e atividade fÃsica, tendencialmente reduzida. Vários estudos sugerem uma relação direta entre a alimentação e o CCR, ditando o possÃvel papel da alimentação como fator de risco ou fator protetor de CCR. A carne vermelha e processada, bem como o consumo de álcool, estão frequentemente associados ao aumento de risco de CCR. Por outro lado, frutos, vegetais, outros alimentos ricos em fibras e peixe, associam-se a um risco diminuÃdo de CCR. Os mecanismos subjacentes à alimentação não são ainda totalmente conhecidos. Até ao momento foram descritas funções essenciais dos componentes dietéticos na inibição ou progressão da inflamação do cólon, evento fundamental na carcinogénese colorretal e transversal a todas as situações de CCR.
Objetivos: Comprovar a relação entre a alimentação e o risco de CCR; identificar quais os alimentos que estão associados a um aumento ou à diminuição do risco da doença; identificar os mecanismos subjacentes ao efeito potenciador ou protetor que os alimentos conferem; identificar através dos quais os alimentos interferem na carcinogénese colorretal; definir quais as estratégias necessárias para otimizar a prevenção primária desta doença.
Métodos: Foi efetuada uma revisão pormenorizada com base na literatura recente e disponÃvel na base de dados PubMed e B-on, referente ao possÃvel papel da alimentação no desenvolvimento de Carcinoma Colorretal e os mecanismos pelos quais exerce a sua ação.
Conclusões: os resultados dos estudos analisados sugerem que o CCR pode em grande parte percentagem de casos ser prevenido através do recurso à adoção de uma alimentação e estilo de vida saudáveis. As carnes vermelhas e processadas estão associadas a um aumento do risco desenvolver Carcinoma Colorretal, principalmente devido à produção de aminas heterocÃclicas, devendo o seu consumo ser reduzido.
or outro lado, o peixe produz um efeito oposto, exercendo um efeito protetor, principalmente através da diminuição da produção de mediadores pró-inflamatórios. Também os frutos e vegetais se associam a um risco menor de desenvolver esta neoplasia, devendo o seu consumo ser elevado. As propriedades quimiopreventivas destes alimentos devem-se, sobretudo, à inibição da inflamação no cólon, e também a mecanismos antioxidantes, pró-apoptóticos e de paragem do ciclo celular.Introduction: Colorectal carcinoma is a tumor with high incidence rate, particularly in Western countries, having been noticed an increase in incidence in Portugal in the past 30 years. It is widely accepted that progressive changes in lifestyle, regarding diet and reduced physical activity has decisively contributed to this increase. Several studies suggest a direct relationship between diet and CRC, dictating the possible role of diet as a risk factor or protective factor for CRC. Red and processed meat and alcohol consumption are often associated to increased risk of CRC. On the other hand, fruit, vegetables, other fiber rich foods and fish are associated to decreased risk of CRC. The underlying mechanisms of diet are not yet fully known. Up until now the essential functions of dietary components have been described as to inhibiting or helping to progress inflammations of the colon, the key event in colorectal carcinogenesis and transversal to all situations of CRC.
Objectives: Demonstrate the relationship between diet and the risk of Colorectal Carcinoma; identify which food is associated with an increased or decreased risk of disease; identify the mechanisms of diet underlying the potentiating effect; determine necessary strategies to optimize the primary prevention of this disease.
Methods: A detailed review was performed, based on the literature available on CRC and the mechanisms by which exerts its action.
Conclusions: The results of the studies reviewed suggest that the CCR can be largely prevented by adopting a healthy diet and lifestyle. Red and processed meat are associated with increased risk of CRC, mainly due to the production of heterocyclic amines and its consumption should be reduced. On the other hand, fish produces an opposite effect, exerting a protective effect, mainly by decreasing the production of pro-inflammatory mediators. Fruit and vegetables are also associated with decreased risk of developing the disease, and its consumption should be increased. The chemopreventive properties of these foods are due mainly to the inhibition of colon inflammation, as well as antioxidant, pro-apoptotic and cell cycle arrest mechanisms
Apollo to Artemis: Mining 50-Year Old Records to Inform Future Human Lunar Landing Systems
Under the Artemis lunar exploration program, NASA is committed to landing American astronauts on the moon by 2024. While NASAs new Space Launch System rocket and Orion capsule will carry astronauts from Earth to the Gateway, the human lunar landing system has not yet been fully defined. As in the Apollo program, there are concerns for vehicle weight and internal volume such that seats may not be desirable, and standing during lunar descent and ascent may be a preferred engineering solution. With such a design, astronauts will experience +GZ (head-to-foot) accelerations during capsule accelerations, and it is unclear whether spaceflight deconditioned astronauts can tolerate these. Apollo astronauts stood during lunar descent and ascent, and the data contained in the early program records for those missions represent a unique resource that may provide insights to the cardiovascular stress associated with this human landing system design
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