bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparing the Course of Mental Health Over the First Year After Stroke With Healthy Controls in Colombia, South America
Authors: Sutter Megan , Olabarrieta Landa Laiene , Calderón Chagualá Amilkar , Chacón Peralta Helmer , Vergara Torres Gina , Perrin Paul B. , Arango‐Lasprilla Juan Carlos 
Published: July 2016

AbstractBackgroundStroke is a primary cause of death and disability in upper‐middle–income countries such as Colombia. Given the lack of comprehensive rehabilitation for stroke patients in Colombia, there is a need to assess longitudinal mental health problems poststroke in this region.ObjectiveTo compare the course of mental health in stroke patients to healthy controls over the first year poststroke in Ibague, Colombia.DesignCross‐sectional study.SettingThe Psychological Attention Center of Antonio Nariño University in Ibague, Colombia.ParticipantsStroke patients (n = 50) and age‐ and gender‐matched healthy controls (n = 50).MethodsPatients and controls completed self‐report Spanish versions of demographic information, injury‐related characteristics, and mental health questionnairesMain Outcome MeasurementsOutcomes assessed included mental health (depression, anxiety, and stress) at 3, 6, and 12 months poststroke.ResultsHierarchical linear models suggested that stroke patients had worse depression and anxiety over time than controls (P < .001). Among patients, depression and anxiety decreased over time (P < .001), whereas stress increased over time (P < .01). The findings suggest that although anxiety and depression improved over time in stroke patients, their mental health remained significantly lower than that of controls.ConclusionsThis is the first study to examine the course of mental health over the first year poststroke in Latin America, specifically in Ibague, Colombia. Despite the improvements in anxiety and depression over the first year poststroke, patient anxiety and depression were still worse in comparison to those in healthy controls. The current findings indicate a need for rehabilitation services in Colombia, especially targeting mental health issues.Level of EvidenceI
Impact of Cognition on Burn Inpatient Rehabilitation Outcomes
Authors: Bajorek Alexander J. , Slocum Chloe , Goldstein Richard , Mix Jacqueline , Niewczyk Paulette , Ryan Colleen M. , Hendricks Carla Tierney , Zafonte Ross , Schneider Jeffrey C. 
Published: July 2016

AbstractBackgroundA significant proportion of burn injury patients are admitted to inpatient rehabilitation facilities (IRFs). There is increasing interest in the use of functional variables, such as cognition, in predicting IRF outcomes. Cognitive impairment is an important cause of disability in the burn injury population, yet its relationship to IRF outcomes has not been studied.ObjectiveTo assess how cognitive function affects rehabilitation outcomes in the burn injury population.DesignRetrospective study.SettingInpatient rehabilitation facilities in the United States.ParticipantsA total of 5347 adults admitted to an IRF with burn injury between 2002 and 2011.Methods or InterventionsMultivariable regression was used to model rehabilitation outcome measures, using the cognitive domain of the Functional Independence Measure (FIM) instrument as the independent variable and controlling for demographic, medical, and facility covariates.Main Outcome MeasurementsFIM total gain, readmission to an acute care setting at any time during inpatient rehabilitation, readmission to an acute care setting in the first 3 days of IRF admission, rate of discharge to the community setting, and length of stay efficiency.ResultsCognitive FIM total at admission was a significant predictor of FIM total gain, length of stay efficiency, and acute readmission at 3 days (P < .05). Cognitive FIM total scores did not have an impact on acute care readmission rate or discharge to the community setting.ConclusionsCognitive status may be an important predictor of rehabilitation outcomes in the burn injury population. Future work is needed to further examine the impact of specific cognitive interventions on rehabilitation outcomes in this population.Level of EvidenceII
Preferencias de carrera en médicos que eligen rotaciones rurales de mayor duración
Authors: Hays Richard 
Published: July 2016

Introducción: En Australia, los estudiantes de medicina rotan en especialidades clínicas durante 6-8 semanas en hospitales urbanos. Para aumentar el interés por las carreras rurales, los estudiantes de algunas escuelas pueden elegir rotaciones de mayor duración (hasta un año) en clínicas rurales. Las rotaciones longitudinales integradas (LIC, por sus siglas en inglés) ocurren en lugares de atención primaria, como clínicas rurales y escuelas de medicina rural.
Objetivo: Evaluar el efecto de las rotaciones rurales más extensas sobre la decisión final en la carrera de medicina en Australia.
Método: Se estudiaron 3 grupos de estudiantes graduados en 2011: 276 con al menos 700 h de prácticas rurales (casi la mitad del año académico), 772 de las mismas escuelas con menos de 700 h de prácticas rurales y 5,326 de 16 escuelas que, o bien no ofrecieron rotaciones rurales, o muy pocos las realizaron. Se compararon los datos de los 3 grupos con la prueba de 2.
Resultados: Un total de 3,483 estudiantes fueron de lugares otorgados por la Commonwealth (CSP); 1,375 de lugares asegurados con rotaciones rurales (MRBS) o médicas (BMP); 414 con pago completo en lugares domésticos (DFF), y 926 en zonas con pago completo internacional (IFF). Es más probable que los estudiantes CSP elijan una LIC en comparación con los IFF ( 256.4; p < 0.05). Los que eligieron una LIC tuvieron más rotaciones rurales (2 124.5, p < 0.05) y elección por las carreras fuera de las áreas metropolitanas y en comunidades más pequeñas ( 2 182.2, p < 0.05). Aquellos que realizaron LIC tuvieron preferencias similares a las de otros estudiantes en las carreras futuras, con excepción de medicina de urgencias y medicina rural, aunque no para medicina familiar (2 53.4; p < 0.05).
Discusión y conclusiones: Los médicos con rotaciones rurales parecen tener mayor preferencia por carreras en el área rural una vez graduados, lo que parece ser una estrategia que podría aumentar el número de médicos en áreas rurales. Se necesita más investigación para determinar los desenlaces de todos los modelos de las rotaciones rurales, con la inclusión de modelos de hospitales más pequeños de medicina general y modelos de atención primaria. La relevancia para otros sistemas de educación y el contexto en Australia también deben ser estudiados.
Testing the “tropical storm” hypothesis of Yucatan Peninsula climate variability during the Maya Terminal Classic Period
Authors: Medina-Elizalde Martín , Polanco-Martínez Josué Moises , Lases-Hernández Fernanda , Bradley Raymond , Burns Stephen 
Published: July 2016

AbstractWe examine the “tropical storm” hypothesis that precipitation variability in the Yucatan Peninsula (YP) was linked to the frequency of tropical cyclones during the demise of the Classic Maya civilization, in the Terminal Classic Period (TCP, AD 750—950). Evidence that supports the hypothesis includes: (1) a positive relationship between tropical storm frequency and precipitation amount over the YP today (proof of feasibility), (2) a statistically significant correlation between a stalagmite (Chaac) quantitative precipitation record from the YP and the number of named tropical cyclones affecting this region today (1852—2004) (calibrationsensu lato), and, (3) correlations between the stalagmite Chaac precipitation record and an Atlantic basin tropical cyclone count record and two proxy records of shifts in macroscale climate and ocean states that influence Atlantic tropical cyclongenesis. At face value, regional paleotempestology proxy records suggest that tropical storm activity in the YP was either similar or significantly lower than today during the TCP. The “tropical storm” hypothesis has implications for our understanding of the role the hydrological cycle played in the collapse of Classic Maya polities and the role of tropical storms in possibly ameliorating future drought in the YP and other tropical regions.
Estimation of the Effect of a Parameter Change on the Roots of Stability Equations
Authors: Mitchell K. 
Published: July 2016

SummaryA method is given for calculating approximately the changes in the roots of a stability secular equation caused by a change in any of the parameters involved. General formulas are given applicable to any quartic equation, and special formulae are also given applicable to the stability of an aeroplane: lateral stability in the text, and longitudinal stability in an appendix.
The method of using the formulae is illustrated by applying them to a particular calculation of the lateral stability of an aeroplane, and a check of the results is made by comparing the predicted approximate changes with those calculated by solution of the modified period equations. It is shown that the formulae are reliable, for this typical case, for any reasonable changes in any parameter other than nv.
If the changes in the derivatives are made equal to the probable error with which they can be measured, the formulae enable us to evaluate the probable errors of the roots. These are found to be considerable, and to arise mainly from uncertainties in yv, nv and nr: if these could be reduced to 0.03 in yv and 0.006 in the others, the uncertainties in the roots would be reduced to some ten per cent, of their values, except for a larger uncertainty in the root corresponding to the slow spiral motion.
Note on the dependence of flap hinge moment derivatives on hinge
position
Authors: Duncan W.J. 
Published: July 2016

Summary
It is shown to be a consequence of kinematics and statics that the
aerodynamic derivative expressing the rate of change of hinge moment of a
plain flap with the angular setting of the flap varies parabolically with
the chordwise position of the hinge. The derivative expressing the rate of
change of hinge moment with incidence of the main surface varies linearly
with the hinge position. Similar conclusions hold for the derivatives of the
hinge moment with respect to the corresponding angular velocities.
The Profile Drag of Yawed Wings of Infinite Span
Authors: Young A.D. , Booth T.B. 
Published: July 2016

SummaryA method is developed for calculating the profile drag of a yawed wing of infinite span, based on the assumption that the form of the spanwise distribution of velocity in the boundary layer, whether laminar or turbulent, is insensitive to the chordwise pressure distribution. The form is assumed to be the same as that accepted for the boundary layer on an unyawed plate with zero external pressure gradient. Experimental evidence indicates that these assumptions are reasonable in this context. The method is applied to a flat plate and the N.A.C.A. 64-012 section at zero incidence for a range of Reynolds numbers between 106 and 108, angles of yaw up to 45°, and a range of transition point positions. It is shown that the drag coefficients of a flat plate varies with yaw as cos½ Λ (where Λ is the angle of yaw) if the boundary layer is completely laminar, and it varies as if the boundary layer is completely turbulent. The drag coefficient of the N.A.C.A. 64-012 section, however, varies closely as cos½ Λ for transition point positions between 0 and 0.5 c. Further calculations on wing sections of other shapes and thicknesses and more detailed experimental checks of the basic assumptions at higher Reynolds numbers are desirable.
Longitudinal Waves in Beams
Authors: Bishop R. E. D. 
Published: July 2016

SummaryThe elementary engineering theory of longitudinal waves in beams allows for no dispersion, whereas Love's corrected version of it predicts that very short waves are not propagated. A new correction is added which overcomes these defects. To do this, a simple theorem is proved concerning certain types of closed region. A method of improving Love's formula and the present one is illustrated.
Aerofoil Theory for Swallow Tail Wings of Small Aspect Ratio
Authors: Robinson A. 
Published: July 2016

SummaryA method is developed for the calculation of the aerodynamic forces acting on a “swallow tail” wing (Figs. l(a) and l(b)) of small aspect ratio. For a given incidence, lift and induced drag coefficient are, within the limits of the theory, proportional to aspect ratio and independent of Mach number. The exact solution is derived for the limiting case of small sweepback of the trailing edge. A numerical method is indicated for the more general case.
The Distribution of Lift over the Surface of Swept Wings
Authors: Küchemann D. 
Published: July 2016

SummaryA simple method is given for calculating, in incompressible flow, the spanwise and chordwise loadings on thin swept wings with symmetrical aerofoil sections and of moderate and large aspect ratios. The present note is based on, and continues, the investigation described in an earlier paper. The design of swept wings with given spanwise and chordwise load distributions, obtained by modifying the plan form of the wing or by adding camber and twist, is briefly considered, as well as the design of swept wings which give minimum induced drag.
Impulsive and Indicial Admittances of Simple Dynamical Chains
Authors: Duncan W. J. 
Published: July 2016

SummaryThe responses of systems, whose equations of motion are linear, to arbitrary applied forces are conveniently calculable by the use of impulsive or indicial admittances. Expressions for these admittances are here given explicity for some simple dynamical chains and the procedure for their calculation in chains with more degrees of freedom is outlined. Some general characteristics of the dynamical chains are also examined.
The Application of a Block Diagram Representation to Aircraft Stability Analysis
Authors: Summerlin F. A. , Sullivan N. 
Published: July 2016

SummaryThe block diagram representing an aircraft in either its lateral or longitudinal motion is given and is used to explain the aircraft response in the antisymmetric stick-fixed case. A generalised autopilot is added to the aircraft diagram and the method of analysing the combination by conventional servo techniques is indicated. It is shown how an estimate can be made of the effects on stability of non-linearities in the output member of the control system.
The Influence of Biaxial Mean Stresses on the Failure of Tubes by Fatigue
Authors: Cox H. L. , Owen N. B. 
Published: July 2016

SummaryThin-walled tubes, in. in diameter, of three hard aluminium alloys and of mild steel have been tested in fatigue under three systems of alternating stresses while subjected to biaxial mean tensions imposed by means of internal pressure. In fatigue under direct or bending stresses the hoop tension in the walls of the aluminium alloy tubes did not seriously reduce the fatigue endurance, but it did markedly affect the mode and rate of crack propagation; cracks initially transverse to the tube axis tended to develop very rapidly in the axial direction. This tendency was present under both fluid and gas pressure, and under gas pressure the cracks propagated so fast that the test piece was often blown to pieces before the gas pressure fell by leakage through the cracks. The gradual taper in wall thickness along the fillets joining the test section to the enlarged ends offered no barrier to propagation of the axial cracks and the whole test piece, including its enlarged ends, was often shattered. Propagation of the axial cracks was preventible by sufficiently reducing the fillet radius, or by a ring glued on. Under alternating torsion, both endurance and mode of failure were affected by internal gas pressure. The initial fatigue crack, either circumferential or axial, often extended over a length comparable with the diameter of the tube, except under low ranges of shear stress when the crack length was sometimes very short. At each end the cracks forked in a characteristic manner and under moderate gas pressure the portions of tHe wall between the prongs of the fork were blown outwards. Under high pressure explosive failure and fragmentation often occurred. Mild steel under alternating torsion with internal gas pressure exhibited the same modes of failure, and two or more fatigue cracks were often formed simultaneously. Under high hoop tension, cracks propagated rapidly and one test piece, after two million cycles endurance, failed by exploding. However, no mild steel test piece was fragmented. A tentative explanation is offered of the reason why, in tubes of small diameter, rather short fatigue cracks may be expected to lead to fast fracture under the static loading. Attention is drawn to the inference that the initial fatigue crack itself must develop very quickly to considerable length.
The Theory of Melting Ablation, with Vaporisation, Gas-Phase Chemical Reaction, Surface Pyrolysis, and Transient Effects
Authors: Spalding D. B. 
Published: July 2016

SummaryStandard techniques of mass-transfer theory are used for the prediction of ablation rates; the thermodynamic and chemical-kinetic material properties are introduced by way of enthalpy-composition diagrams; the interface condition is given as the root of a single non-linear equation involving material properties. The paper treats both steady ablation and unsteady ablation, the latter by means of a quasi-steady assumption which confines transient effects to the solid phase.Detailed comparisons are made with the methods of Sutton, Bethe and Adams, and Lees. The formulations of the paper are shown to be equivalent to, but more general than, those of the earlier authors; it is suggested that they are simpler as well. Some improvements over previous practice are recommended in connection with the calculation of the shear stress at the interface.
The Elastic Instability of a Complete Spherical Shell
Authors: Thompson J.M.T. 
Published: July 2016

SummaryThe elastic instability of a complete spherical shell under uniform external pressure is studied experimentally and theoretically. The premature snapping of a thin elastic shell, made of polyvinyl chloride, is seen to be classical in nature. The experimental maximum pressure and pre-snapping bending deformation are correlated with the theoretical behaviour of an initially imperfect shell. The large deflection behaviour of a perfect shell is assessed experimentally, and the stable post-buckling states are observed to be rotationally symmetric. A fairly precise theoretical analysis of these states is performed, the use of a high-speed digital computer allowing a considerable advance over previous treatments. The experimental and theoretical post-buckling curves are in good agreement, yielding the first detailed correlation of post-snapping equilibrium states in the field of shell instability.
The Stacking of Compressor Stage Characteristics to Give an Overall Compressor Performance Map
Authors: Doyle M. D. C. , Dixon S. L. 
Published: July 2016

SummaryA method of calculation is developed to compute the overall performance of a multi-stage axial compressor, from a knowledge of the individual stage characteristics, by a “stacking” technique. Compressor models are designed and their overall performance calculated. These results are compared to show, qualitatively, the effect of alterations in design and stage performance on overall performance and to find how compressors should be designed for optimum performance.
The Static Aeroelasticity of Slender Configurations
Authors: Hancock G. J. 
Published: July 2016

SummaryThe validity and applicability of the static margin (stick fixed) Kn,where as defined by Gates and Lyon is shown to be restricted to the conventional flexible aircraft. Alternative suggestions for the definition of static margin are put forward which can be equally applied to the conventional flexible aircraft of the past and the integrated flexible aircraft of the future. Calculations have been carried out on simple slender plate models with both linear and non-linear aerodynamic forces to assess their static stability characteristics.
Practical Bypass Mixing Systems for Fan Jet Aero Engines
Authors: Frost T. H. 
Published: July 2016

SummaryMixing systems have many applications in gas turbines and aircraft jet propulsion, e.g. mixing zones in combustion chambers, ejectors for jet lift thrust augmentors and supersonic propulsion systems. A further application similar to that of combustion chamber mixing is that of mixing the cold and hot exhausts of a bypass jet engine. These are both characterised by mixing at constant static pressure and approximately constant total pressure as opposed to the more general case of unequal pressures in ejector systems (Fig. 1).The exhaust mixing process as used in Rolls-Royce bypass jet engines, e.g. Spey and Conway, enables the potential of the bypass principle, in terms of minimum weight and fuel consumption, to be exploited by a simple practical device.This is achieved by mixing the two streams in a common duct of fairly short dimensions with a corrugated metal interface on the inlet side. The consideration of these practical systems forms the main topic of this paper.
Shear Buckling of Orthogonally Stiffened, Infinitely Long Simply-Supported Plates–Stiffeners having Torsional and Flexural Rigidities
Authors: Rockey K. C. , Cook I. T. 
Published: July 2016

SummaryThe paper presents a solution to the buckling under shear stress of infinitely long plates orthogonally reinforced by stiffeners having both flexural and torsional rigidity. Each family of stiffeners is assumed to consist of equally spaced identical stiffeners. Numerical results are given for the case of a plate with transverse stiffeners and a central longitudinal stiffener for the following three cases:
(i)Transverse and longitudinal stiffeners of closed tubular cross-section.(ii)Transverse stiffeners of closed tubular cross-section, longitudinal stiffeners possessing only flexural rigidity.(iii)Transverse stiffeners possessing only flexural rigidity, the longitudinal stiffeners being of closed tubular cross-section.Relationships between the buckling stress parameter K and the flexural rigidity parameter γ of the stiffeners are presented for each of the three cases when the identical transverse stiffeners are placed at spacings of d, 0·8d and 0·5d, where d is the depth of the webplate.Case (i) has provided values of the buckling coefficient K for finite rectangular plates clamped on three edges and simply-supported on the remaining edge.
A Numerical Method for Calculating Viscous Flow Round Multiple-Section Aerofoils
Authors: Seebohm T , Newman B G 
Published: July 2016

A numerical method is described for predicting incompressible, attached flow round multiple-section aerofoils at high Reynolds number. Interaction between wakes and boundary layers is not accounted for, but the method is nevertheless suitable for optimisation of design in the take-off condition. The solution is obtained in three steps:
(i)The calculation of the outer, potential flow using a conventional Kutta condition for each aerofoil section.(ii)The calculation of viscous boundary layers and wakes.(iii)The combination of the inviscid and viscous solutions to effect proper matching at the edges of the boundary layers and wakes and a more accurate specification of the circulation in the inviscid flow.