Atividade amilolítica e qualidade fisiológica de sementes armazenadas de milho super doce tratadas com ácido giberélico.

O uso de reguladores de crescimento na fase de germinação melhora o desempenhodas plântulas, acelerando a velocidade de emergência e realçando o potencial das sementes devárias espécies, mesmo sob condições adversas. Este trabalho teve como objetivo avaliar ainfluência do ácido giberélico na atividade amilolítica e no vigor de sementes armazenadas demilho super doce. O experimento foi conduzido nos Laboratórios de Análise de Sementes doDepartamento de Produção Vegetal/FCA e no Laboratório de Bioquímica de Plantas doDepartamento de Química e Bioquímica/IB da Universidade Estadual Paulista (UNESP/Botucatu),entre os meses de julho e setembro de 2001, onde foram feitas as avaliações da qualidade fisiológica,através dos testes de germinação, vigor e bioquímicos. Sementes de milho super doce da cultivarDO-04, foram acondicionadas em sacos de papel e armazenadas por oito meses em câmara seca(40% UR). Após este período, foram colocadas para germinar em rolos de papel toalha, embebidoscom GA3 nas concentrações zero; 50; 100; 150 e 200mg.L-1. Foram avaliadas a germinação, vigore atividade amilolítica das sementes. As sementes submetidas à pré-embebição em solução de50mg.L-1 de ácido giberélico, apresentaram maior germinação e vigor, menor teor de proteínastotais e maior atividade amilolítica

Transcranial cortico-cortical paired associative stimulation (ccPAS) over ventral premotor-motor pathways enhances action performance and corticomotor excitability in young adults more than in elderly adults

Transcranial magnetic stimulation (TMS) methods such as cortico-cortical paired associative stimulation (ccPAS) can increase the strength of functional connectivity between ventral premotor cortex (PMv) and primary motor cortex (M1) via spike timing-dependent plasticity (STDP), leading to enhanced motor functions in young adults. However, whether this STDP-inducing protocol is effective in the aging brain remains unclear. In two groups of young and elderly healthy adults, we evaluated manual dexterity with the 9-hole peg task before and after ccPAS of the left PMv-M1 circuit. We observed that ccPAS enhanced dexterity in young adults, and this effect was anticipated by a progressive increase in motor-evoked potentials (MEPs) during ccPAS administration. No similar effects were observed in elderly individuals or in a control task. Across age groups, we observed that the magnitude of MEP changes predicted larger behavioral improvements. These findings demonstrate that left PMv-to-M1 ccPAS induces functionally specific improvements in young adults' manual dexterity and an increase in corticomotor excitability, but altered plasticity prevents the effectiveness of ccPAS in the elderly

Neurophysiological Markers of Premotor–Motor Network Plasticity Predict Motor Performance in Young and Older Adults

Aging is commonly associated with a decline in motor control and neural plasticity. Tuning cortico–cortical interactions between premotor and motor areas is essential for controlling fine manual movements. However, whether plasticity in premotor–motor circuits predicts hand motor abilities in young and elderly humans remains unclear. Here, we administered transcranial magnetic stimulation (TMS) over the ventral premotor cortex (PMv) and primary motor cortex (M1) using the cortico–cortical paired-associative stimulation (ccPAS) protocol to manipulate the strength of PMv-to-M1 connectivity in 14 young and 14 elderly healthy adults. We assessed changes in motor-evoked potentials (MEPs) during ccPAS as an index of PMv-M1 network plasticity. We tested whether the magnitude of MEP changes might predict interindividual differences in performance in two motor tasks that rely on premotor-motor circuits, i.e., the nine-hole pegboard test and a choice reaction task. Results show lower motor performance and decreased PMv-M1 network plasticity in elderly adults. Critically, the slope of MEP changes during ccPAS accurately predicted performance at the two tasks across age groups, with larger slopes (i.e., MEP increase) predicting better motor performance at baseline in both young and elderly participants. These findings suggest that physiological indices of PMv-M1 plasticity could provide a neurophysiological marker of fine motor control across age-groups

The ATLAS magnet test facility at CERN

The magnet system for the ATLAS detector at CERN consists of a Barrel Toroid (BT), two End-Cap Toroids (ECT) and a Central Solenoid (CS). The overall dimensions of the system are 20 m in diameter by 26 m in length. Before underground installation all coils will be tested on surface in a magnet test facility which is under construction. Moreover two model coils are tested as well as subsystems. In this paper the design and construction of the test facility is presented. (3 refs)

ATLAS B0 toroid model coil test at CERN

The ATLAS superconducting magnet system consists of a Barrel Toroid, two End-Cap Toroids and a Central Solenoid. The Barrel Toroid, with overall dimensions of 20-m diameter by 26-m length, is made of eight individual coils symmetrically assembled around the central axis with a warm structure. The system is presently under construction in industry. In order to verify the construction concepts a model coil B0, a 9-m short version of a single Barrel Toroid coil, was built. Since April 2001, an extensive test program is underway at CERN to characterize the mechanical, thermal, electrical and magnetic properties of the coil. The magnet successfully achieved the 20-kA nominal operating current in July 2001. The test program and the main results are reported. (9 refs)

Atividade amilolítica e germinação de sementes de milho submetidas à deficiência de oxigênio.

Este trabalho teve como objetivo avaliar os efeitos causados pela deficiência de O2 em sementes de milho na atividade amilolítica e sua influência no vigor das sementes e crescimentodas plântulas

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson