Changes in circle area after gravity compensation training in chronic stroke patients

After a stroke, many people experience difficulties to selectively activate muscles. As a result many patients move the affected arm in stereotypical patterns. Shoulder abduction is often accompanied by elbow flexion, reducing the ability to extend the elbow. This involuntary coupling reduces the patient's active range of motion. Gravity compensation reduces the activation level of shoulder abductors which limits the amount of coupled elbow flexion. As a result, stroke patients can instantaneously increase their active range of motion [1]. The objective of the present study is to examine whether training in a gravity compensated environment can also lead to an increased range of motion in an unsupported environment. Parts of this work have been presented at EMBC2009, Minneapolis, USA

Rapid shifts in Atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (Attini, Formicidae)

Fungus gardens of the basidiomycete Leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. Recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix associated with cell walls, rather than toward structural cell wall components such as cellulose and hemicelluloses. Substrate constituents are also known to be sequentially degraded in different sections of the fungus garden. To test the plasticity in the extracellular expression of fungus-garden enzymes, we measured the changes in enzyme activity after a controlled shift in fungal substrate offered to six laboratory colonies of Atta cephalotes. An ant diet consisting exclusively of grains of parboiled rice rapidly increased the activity of endo-proteinases and some of the pectinases attacking the backbone structure of pectin molecules, relative to a pure diet of bramble leaves, and this happened predominantly in the most recently established top sections of fungus gardens. However, fungus-garden amylase activity did not significantly increase despite the substantial increase in starch availability from the rice diet, relative to the leaf diet controls. Enzyme activity in the older, bottom sections of fungus gardens decreased, indicating a faster processing of the rice substrate compared to the leaf diet. These results suggest that leaf-cutting ant fungus gardens can rapidly adjust enzyme activity to provide a better match with substrate availability and that excess starch that is not protected by cell walls may be digested by the ants rather than by the fungus-garden symbiont

Mathematics in different settings: plenary panel.

When we think about the title “Mathematics in different settings”, a number of questions arise. For example: • How many mathematics are there – one or many? Is there a mathematics that is “prior to”, or independent of, any setting? • What (who) is it that makes settings “different”? And how does this relate to social differences among people? • What is an appropriate typology of different settings – for research or for curriculum design purposes? Relatedly, we might ask: who decides what is “important”? • What is the nature of relations among policy arrangements, research and educational institutional settings? • How are different settings represented in mathematics teaching and assessment? • What is the relationship of mathematics education researchers to any setting

Vortices in vibrated granular rods

We report the experimental observation of novel vortex patterns in vertically vibrated granular rods. Above a critical packing fraction, moving ordered domains of nearly vertical rods spontaneously form and coexist with horizontal rods. The domains of vertical rods coarsen in time to form large vortices. We investigate the conditions under which the vortices occur by varying the number of rods, vibration amplitude and frequency. The size of the vortices increases with the number of rods. We characterize the growth of the ordered domains by measuring the area fraction of the ordered regions as a function of time. A {\em void filling} model is presented to describe the nucleation and growth of the vertical domains. We track the ends of the vertical rods and obtain the velocity fields of the vortices. The rotation speed of the rods is observed to depend on the vibration velocity of the container and on the packing. To investigate the impact of the direction of driving on the observed phenomena, we performed experiments with the container vibrated horizontally. Although vertical domains form, vortices are not observed. We therefore argue that the motion is generated due to the interaction of the inclination of the rods with the bottom of a vertically vibrated container. We also perform simple experiments with a single row of rods in an annulus. These experiments directly demonstrate that the rod motion is generated when the rods are inclined from the vertical, and is always in the direction of the inclination.Comment: 6 pages, 10 figure, 2 movies at http://physics.clarku.edu/vortex uses revtex

Molecular adaptations to advanced fungus farming in leaf-cutting ant symbiosis

This paper addresses several aspects of legal regulation concerning cosmetics, homeopathy products and medical devices. The Portuguese legal framework, based mainly upon European directives, is analyzed concerning the administrative legal environment of the production, distribution and marketing of these products. It is stressed that legislation aims to achieve a balance between the values of free trade and enterprise, on one side, and the protection of public health protection, on the other side.1. Cosméticos – Regime jurídico dos cosméticos (Decreto-Lei n.º 296/98, de 25 de Setembro; Decreto-Lei n.º 100/2001, de 28 de Março; Decreto-Lei n.º 206/99, de 9 de Junho). 1.1. Noção funcional de produtos cosméticos e de higiene corporal, ilustrada mediante uma lista (indicativa) de exemplos por categorias de produtos cosméticos e de higiene corporal. 1.2. Desnecessidade de obtenção de autorização administrativa prévia, mas dever de notificação ao INFARMED. 1.3. Requisitos de qualidade e regras de composição e de experimentação (Decreto-Lei n.º 100/2001, de 28 de Março, alterado pelo Decreto-Lei n.º 151/2003, de 11 de Julho). 1.4. Obrigação de assistência por um técnico responsável. 1.5. Rotulagem. 1.6. Requisitos da actividade industrial. 1.7. A protecção da confidencialidade (Decreto-Lei n.º 206/99, de 9 de Junho). 1.8. Sanções. 1.8.1. Poderes de controlo e fiscalização do INFARMED. 1.8.2. Suspensão da comercialização dos produtos por razões de saúde pública. 1.8. 3. As contra-ordenações 2. Produtos Homeopáticos. 2.1. Linhas gerais do Regime jurídico dos produtos homeopáticos (Decreto-Lei n.º 94/95, de 9 de Maio). 2.1.1. Garantia da qualidade e da segurança de utilização dos produtos homeopáticos como salvaguarda da saúde pública.2.1.2. Garantia aos seus utilizadores do fornecimento de informações claras sobre o seu carácter homeopático e a sua inocuidade). 2.2. Noção e modalidades de produtos homeopáticos. 2.2.1. Medicamentos homeopáticos. 2.2.2. Produtos farmacêuticos homeopáticos. 2.3. Delimitação do âmbito de aplicação da lei dos produtos homeopáticos aos produtos farmacêuticos homeopáticos e aplicação do regime jurídico dos medicamentos para uso humano (Decreto-Lei n.º 72/91, 8.2) aos medicamentos homeopáticos. 2.3.1. Comercialização de medicamentos homeopáticos entre fabricantes, grossistas, laboratórios e farmácias. 2.3.2. Venda de medicamentos homeopáticos ao público. 2.4. Regime de registo simplificado da introdução no mercado dos produtos farmacêuticos homeopáticos. 2.4.1. O pedido de registo. 2.4.2. Necessidade de autorização para o fabrico de produtos farmacêuticos homeopáticos. 2.4.3. Exigência de direcção técnica. 2.4.4. Requisitos relativos à rotulagem e ao folheto informativo. 2.5. Fiscalização e contra-ordenações. 3. Dispositivos Médicos – Regime jurídico dos dispositivos médicos (Decreto-Lei n.º 273/95, de 23 de Outubro, alterado pelo Decreto-Lei n.º 30/2003, de 14 de Fevereiro). 3.1. Noção e modalidades de dispositivos médicos. 3.2. Delimitação positiva e negativa do âmbito de aplicação do regime geral dos dispositivos médicos; regimes especiais, como o dos dispositivos médicos para diagnóstico in vitro (Decreto-Lei n.º 189/2000, de 12 de Agosto - que transpõe a Directiva 98/79/CE do Parlamento Europeu e do Conselho, de 27 de Outubro). 3.3. Requisitos de colocação no mercado. 3.3.1 As normas técnicas e os procedimentos de avaliação da conformidade. 3.3.2. Cláusula de salvaguarda – os poderes especiais do presidente do Conselho de Administração do INFARMED. 3.4. O sistema de vigilância (vide Portaria n.º 196/2004, de 1 de Março: aprova o Regulamento do Sistema Nacional de Vigilância de Dispositivos Médicos). 3.5. Fiscalização e contraordenaçõe

Water bottle flipping physics

The water bottle flipping challenge consists of spinning a bottle, partially filled with water, and making it land upright. It is quite a striking phenomenon, since at first sight, it appears rather improbable that a tall rotating bottle could make such a stable landing. Here, we analyze the physics behind the water bottle flip, based on experiments and an analytical model that can be used in the classroom. Our measurements show that the angular velocity of the bottle decreases dramatically, enabling a nearly vertical descent and a successful landing. The reduced rotation is due to an increase in the moment of inertia, caused by the in-flight redistribution of the water mass along the bottle. Experimental and analytical results are compared quantitatively, and we demonstrate how to optimize the chances for a successful landing.</p