UMTS Network Planning - The Impact of User Mobility

The impact of user mobility on network planning is investigated. For a system of two base stations the stationary distribution of a Markov chain, including mobility, is computed

Environmental co-operatives reconnect farming, ecology and society

Regional diversity, diversified farming styles and endogenous development are hot issues in the current political debate on European agriculture. This article presents a historical overview of development experiences and elaborates on the emergence of environmental co-operatives in Dutch farming. They are unique ‘field laboratories’ for innovations toward sustainable rural development. The achievements in terms of environmental gains and social cohesion are coupled with cost reduction for the farmers and the stat

A Self-Determination Theory Model Investigating the Relationship between High School Male Student-Athlete Motivation and Academic Achievement

This non-experimental regression study examined the relationship between six motivational factors and academic performance for male high school student-athletes. Research has shown motivation in athletics can have an effect on academic achievement. The study was conducted at six public high schools in the northeast region of South Carolina. The revised Sport Motivation Scale (SMS-II) was the survey instrument used to collect athletic motivational levels of the 10th-12th grade high school male student-athletes (n=140). Academic achievement was measured through overall student grade point average (GPA). Sport type and grade level were statistically controlled in this study making them covariates. The data was analyzed by performing a hierarchical multiple regression. Descriptive data was reported and the strength of relationships determined and discussed. The analysis showed the strength of the relationships between the predictor variables (intrinsic, integrated, identified, extrinsic, and non-regulation) and the criterion variable (GPA). The results of the study suggested that overall motivation did not have a statistically significant contribution to GPA. Despite the fact that the overall model was not significant, there were some findings that suggested student-athletes with strong amotivational tendencies may be less likely to be motivated to achieve high academic scores. Future research is still needed in this area and should focus investigating family structure and socio-economic status among participants and ensuring sufficient and more equal representation amongst all sports involved

Effect of Preventive Primary Care Outreach on Health Related Quality of Life Among Older Adults at Risk of Functional Decline: Randomised Controlled Trial

Objective: To evaluate the impact of a provider initiated primary care outreach intervention compared with usual care among older adults at risk of functional decline. Design: Randomised controlled trial. Setting: Patients enrolled with 35 family physicians in five primary care networks in Hamilton, Ontario, Canada. Participants: Patients were eligible if they were 75 years of age or older and were not receiving home care services. Of 3166 potentially eligible patients, 2662 (84%) completed the validated postal questionnaire used to determine risk of functional decline. Of 1724 patients who met the risk criteria, 769 (45%) agreed to participate and 719 were randomised. Intervention: The 12 month intervention, provided by experienced home care nurses in 2004-6, consisted of a comprehensive initial assessment using the resident assessment instrument for home care; collaborative care planning with patients, their families, and family physicians; health promotion; and referral to community health and social support services. Main outcome measures: Quality adjusted life years (QALYs), use and costs of health and social services, functional status, self rated health, and mortality. Results: The mean difference in QALYs between intervention and control patients during the study period was not statistically significant (0.017, 95% confidence interval ?0.022 to 0.056; P=0.388). The mean difference in overall cost of prescription drugs and services between the intervention and control groups was not statistically significant, (-$C165 (£107; 118;$162), 95% confidence interval -$C16 545 to$$16 214; P=0.984). Changes over 12 months in functional status and self rated health were not significantly different between the intervention and control groups. Ten patients died in each group. Conclusions: The results of this study do not support adoption of this preventive primary care intervention for this target population of high risk older adults

Control design for an overactuated wheeled mobile robot

In order to simulate road vehicles in a hardware-in-the-loop test setup, TNO has developed a wheeled mobile robot with independently driven and steered wheels. This robot is overactuated, i.e. the number of actuators exceeds the number of spatial degrees of freedom to be controlled. A position controller based on feedback linearization is presented. This controller takes the overactuatedness into account by using the so-called multicycle approach, which essentially regards the robot as a combination of independent unicycles. As a result, the robot is position controlled while the redundant actuators are used to compensate for weight transfer during acceleration and cornering

Fracturas de implantes de tibia. Consecuencias para los ensayos de los implantes

El objetivo de este trabajo es estudiar los modelos de fracturas de prótesis de tibia descritos en la literatura y, sobre la base de dichos conocimientos, desarrollar un ensayo para implantes en la cual se logren simular condiciones fisiológicas. El caso descrito con mayor frecuencia en la literatura es la migración de la parte medial de la prótesis, fenómeno que, a menudo, antecede a la fractura de la prótesis. La posición defectuosa resultante de dicha migración modifica el eje mecánico y provoca una sobrecarga en la parte medial de la prótesis. Se ha desarrollado un ensayo de implantes que simula el modelo de fallo in-vivo. Dos bases de material sintético de diferente dureza simulan la diferente densidad ósea medial y lateral, para permitir una migración del lado medial del platillo. En el ensayo dinámico el platillo tibial es sometido a una carga de un solo lado y el vástago de la prótesis se apuntala con un contrasoporte. Para simular el entorno fisiológico, todo el dispositivo se encuentra sumergido en una solución de Ringer a 37°. El implante de tibia es expuesto durante 10 millones de ciclos a una carga que corresponde al quíntuple del peso del cuerpo (4.000 N). El punto de aplicación de la fuerza fue tomado de datos de análisis del caminar (marcha en superficie plana, ascendente y descendente, subir escaleras). Con esta carga fisiológica se efectuaron los primeros ensayos. En éstas quedó demostrado que productos clínicamente exitosos podían superar el ensayo. Por el contrario, los productos con modelos de fracturas conocidos no la superaron. Los primeros resultados con estos productos demostraron también que el ensayo generaba muestras de fractura semejantes a las que se producen in vivo. Debido a la configuración fisiológica del dispositivo se somete el sistema completo es decir el platillo, el vástago de la prótesis y la unión - generalmente modular - entre ambos a ensayo. El "ensayo fisiológico de tibia " descrito ayuda a evaluar los diseños de tibia antes de que se autorice su venta. Nuevos implantes y modificaciones de diseño en implantes ya existentes son puestos a la venta después de cumplir con las exigencias del ensayo.Peer Reviewe

Measuring very negative water potentials with polymer tensiometers: principles, performance and applications

In recent years, a polymer tensiometer (POT) was developed and tested to directly measure matric potentials in dry soils. By extending the measurement range to wilting point (a 20-fold increase compared to conventional, water-filled tensiometers), a myriad of previously unapproachable research questions are now open to experimental exploration. Furthermore, the instrument may well allow the development of more water-efficient irrigation strategies by recording water potential rather than soil water content. The principle of the sensor is to fill it with a polymer solution instead of water, thereby building up osmotic pressure inside the sensor. A high-quality ceramic allows the exchange of water with the soil while retaining the polymer. The ceramic has pores sufficiently small to remain saturated even under very negative matric potentials. Installing the sensor in an unsaturated soil causes the high pressure of the polymer solution to drop as the water potentials in the soil and in the POT equilibrate. As long as the pressure inside the polymer chamber remains sufficiently large to prevent cavitation, the sensor will function properly. If the osmotic potential in the polymer chamber can produce a pressure of approximately 2.0 MPa when the sensor is placed in water, proper readings down to wilting point are secured. Various tests in disturbed soil, including an experiment with root water uptake, demonstrate the operation and performance of the new polymer tensiometer and illustrate how processes such as root water uptake can be studied in more detail than before. The paper discusses the available data and explores the long term perspectives offered by the instrument

Realization of a classical counterpart of a scalable design for adiabatic quantum computation

We implement a classical counterpart of a scalable design for adiabatic quantum computation. The key element of this design is a coupler providing controllable coupling between two bistable elements (in our case superconducting rings with a single Josephson junction playing the role of a classical counterpart of superconducting flux qubits) The coupler is also a superconducting ring with a single Josephson junction that operates in the non-hysteretic mode. The flux coupling between two bistable rings can be controlled by changing the magnetic flux through the coupler. Thereby, the coupling can be tuned from ferromagnetic trough zero to to anti-ferromagnetic.Comment: 3 pages, 3 figures v2: extended discussion experimental result