Active summation of excitatory postsynaptic potentials in hippocampal CA3 pyramidal neurons

The manner in which the thousands of synaptic inputs received by a pyramidal neuron are summed is critical both to our understanding of the computations that may be performed by single neurons and of the codes used by neurons to transmit information. Recent work on pyramidal cell dendrites has shown that subthreshold synaptic inputs are modulated by voltage-dependent channels, raising the possibility that summation of synaptic responses is influenced by the active properties of dendrites. Here, we use somatic and dendritic whole-cell recordings to show that pyramidal cells in hippocampal area CA3 sum distal and proximal excitatory postsynaptic potentials sublinearly and actively, that the degree of nonlinearity depends on the magnitude and timing of the excitatory postsynaptic potentials, and that blockade of transient potassium channels linearizes summation. Nonlinear summation of synaptic inputs could have important implications for the computations performed by single neurons and also for the role of the mossy fiber and perforant path inputs to hippocampal area CA3.     

Immunological properties of human decidual macrophages--a possible role in intrauterine immunity

Our aim was to investigate the contribution of decidual macrophages, which constitute an important immune component of the decidua in late gestation, to intrauterine defence mechanisms. Using flow cytometry we examined the ability of decidual macrophages, isolated from term decidua, to bind and phagocytose fluorescence-labelled bacterial and yeast bioparticles. We also assessed their ability to generate superoxide radicals and tumour necrosis factor-alpha following lipopolysaccharide challenge. Decidual macrophages bound bacterial and yeast particles in a dose-dependent manner, which subsequently led to phagocytosis. These macrophages also produced superoxide radicals and the pro-inflammatory cytokine TNF-alpha when challenged with bacterial lipopolysaccharides. These results suggest a role for decidual macrophages in pathogen recognition and clearance during pregnancy, and, therefore, they are likely to protect the fetus against intrauterine infections which might otherwise lead to preterm labour.     

Numerical modeling of an explosion plasma generator,taking into account radiative energy transport and evaporation of the walls

Using a generalized theoretical model, we study the effect of geometrical dimensions and a variety of physical processes on the operation of the explosion plasma generator.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 6, pp. 1012–1020, December, 1982.     

Energy balance and lactation response in Holstein cows supplemented with cottonseed with or without calcium soap.

Holstein cows (n = 58, 21 primiparous), fed corn and wilted grass silages (63:37, DM basis) for free choice consumption, were assigned to control concentrate or supplemented concentrate during wk 1 to 16 postpartum with linted whole cottonseed (15% of projected DMI) alone or with Megalac (.54 kg/d). Our objective was to examine the effects of fatty acids on energy and N balances, total tract digestibility, and milk fatty acids in wk 7 and 16 and to assess total lactation responses. During balance measurements, fatty acids constituted 4.1, 6.8, and 8.6% of DM in control, oilseed, and oilseed plus protected fatty acid diets. Fat additions reduced fiber digestion (attributed to oilseed) and, to some degree, DMI and milk yield, but enhanced fat test without affecting protein percentage. Supplementary fat increased the proportion of C18:0 in milk at the expense of short-chain fatty acids. Supplemental oilseed with or without protected fatty acids reduced total heat production by 6% and reduced heat in excess of maintenance by 8%. Best estimates of NEL in linted whole cottonseed and of fat in Megalac were 1.81 and 5.69 Mcal/kg of DM. In total lactation, primiparous cows yielded more milk and FCM when fed oilseed plus Megalac and less of each when fed oilseed alone than controls. In pluriparous cows, milk yield was reduced by 2.7 kg/d relative to other treatments when oilseed plus Megalac was fed; FCM yield increased about 2 kg/d only when oilseed was supplemented alone. Overall, data suggest that basal ration fat and oilseed supplementation were too high or that supplementation should have been delayed until feed intake was higher.     

Electrical conductivity and porosity relationship in metal foams

This paper presents a literature review of the experimental data and different authors’ proposed equations related to the measurement and modelling of the electrical conductivity of metal foams. The analysis is based on the classification scheme that considers two different foam categories: open-cell and closed-cell foams. A new empirical equation is presented to describe the relationship between porosity and electrical conductivity in foamed materials. The aim of this equation is to encompass the different behaviours previously described for different types of foams in a single equation.     

Study on Urban Infrastructure Development Financing in China(Ⅱ)

4.Typical modes of infrastructure financing in China After summarizing the general situations of infrastructure financing in China,further analyses will be made on several typical modes of infrastructure financing on the basis of the interviews,surveys,and data collections in certain Chinese cities.