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

Tolerância de cultivares de milho à acidez do solo e eficiência de resposta à calagem

A field experiment was conducted on an alic dystrophic latosol which was not cultivated before, aiming to characterize, the tolerance of maize (Zea mays L.)/ cultivars to soil acidity, evaluated through the percentage of saturation of exchangeable Al, and the efficiency to lime response. A randomized block experiment design with split-plots was used. Lime was added to the main plots at rates of 0.0, 3,5 and 13,5 t/ha and the 36 maize cultivars were sown in the sub-plots. Yield differences among cultivars, when compared from the absence of liming, showed a great variability to soil acidity tolerance. A great variability among cultivars to liming response was also observed, this being indicated by the regression coefficient of the linear equation for the relative yield as function of the percentage of, Al saturation, provided by the rates of lime applied. All cultivars were grouped into three classes, based on the yield average obtained from the absence of liming and the average of the regression coefficient of the equations. The classes are the following: 1. 1ow tolerance to soil acidity, with high efficiency to liming response; 2. high tolerance to soil acidity, with low efficiency to liming response; 3. high tolerance to soil acidity and high efficiency to liming response.Conduziu-se um experimento de campo em um Latossolo Roxo álico, nunca cultivado, com o objetivo de caracterizar a tolerância de cultivares de milho (Zea mays L.) à acidez do solo, avaliada através da percentagem de saturação de Al3+ trocável, e sua eficiência de resposta à calagem. Utilizou-se o delineamento experimental de blocos ao acaso com parcelas subdivididas; nas parcelas aplicou-se calcário nas doses de 0; 3,5 e 13,5 t/ha; nas sub-subparcelas semearam-se 36 cultivares de milho. As diferenças no rendimento de grãos entre cultivares cultivadas na ausência de calcário, evidenciaram grande variabilidade na tolerância à acidez do solo. Observou-se também grande variação na eficiência de resposta à calagem, indicada pelo coeficiente de regressão das equações lineares entre o rendimento relativo e a percentagem de saturação Al3+ trocável, proporcionado pelas doses de calcário aplicadas. Com base na média dos rendimentos obtidos em ausência de calagem e na média do coeficiente de regressão daquelas equações, as cultivares foram agrupadas em três classes: baixa tolerância à acidez do solo, com alta eficiência de resposta à calagem; alta tolerância à acidez do solo, com baixa eficiência de resposta à calagem; alta tolerância à acidez do solo e alta eficiência de resposta à calagem

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)

On the road to per cent accuracy - V. The non-linear power spectrum beyond ΛCDM with massive neutrinos and baryonic feedback

In the context of forthcoming galaxy surveys, to ensure unbiased constraints on cosmology and gravity when using non-linear structure information, per cent-level accuracy is required when modelling the power spectrum. This calls for frameworks that can accurately capture the relevant physical effects, while allowing for deviations from Lambda cold dark matter (ΛCDM). Massive neutrino and baryonic physics are two of the most relevant such effects. We present an integration of the halo model reaction frameworks for massive neutrinos and beyond ΛCDM cosmologies. The integrated halo model reaction, combined with a pseudo-power spectrum modelled by HMCode2020 is then compared against N-body simulations that include both massive neutrinos and an f(R) modification to gravity. We find that the framework is 4 per cent accurate down to at least ≈ 3 h Mpc-1 for a modification to gravity of |fR0| ≤ 10-5 and for the total neutrino mass Mν Σmν ≤ 0.15 eV. We also find that the framework is 4 per cent consistent with EuclidEmulator2 as well as the Bacco emulator for most of the considered νwCDM cosmologies down to at least k ≈ 3 h Mpc-1. Finally, we compare against hydrodynamical simulations employing HMCode2020's baryonic feedback modelling on top of the halo model reaction. For νΛCDM cosmologies, we find 2 per cent accuracy for Mν ≤ 0.48 eV down to at least k ≈ 5h Mpc-1. Similar accuracy is found when comparing to νwCDM hydrodynamical simulations with Mν = 0.06 eV. This offers the first non-linear, theoretically general means of accurately including massive neutrinos for beyond-ΛCDM cosmologies, and further suggests that baryonic, massive neutrino, and dark energy physics can be reliably modelled independently