Stem Photosynthesis—A Key Element of Grass Pea (Lathyrus sativus L.) Acclimatisation to Salinity

Grass pea (Lathyrus sativus) is a leguminous plant of outstanding tolerance to abiotic stress. The aim of the presented study was to describe the mechanism of grass pea (Lathyrus sativus L.) photosynthetic apparatus acclimatisation strategies to salinity stress. The seedlings were cultivated in a hydroponic system in media containing various concentrations of NaCl (0, 50, and 100 mM), imitating none, moderate, and severe salinity, respectively, for three weeks. In order to characterise the function and structure of the photosynthetic apparatus, Chl a fluorescence, gas exchange measurements, proteome analysis, and Fourier-transform infrared spectroscopy (FT-IR) analysis were done inter alia. Significant differences in the response of the leaf and stem photosynthetic apparatus to severe salt stress were observed. Leaves became the place of harmful ion (Na⁺) accumulation, and the efficiency of their carboxylation decreased sharply. In turn, in stems, the reconstruction of the photosynthetic apparatus (antenna and photosystem complexes) activated alternative electron transport pathways, leading to effective ATP synthesis, which is required for the efficient translocation of Na⁺ to leaves. These changes enabled efficient stem carboxylation and made them the main source of assimilates. The observed changes indicate the high plasticity of grass pea photosynthetic apparatus, providing an effective mechanism of tolerance to salinity stress.     

The Reciprocal Influences among Motivation,Personality Traits,and Game Habits for Playing Pokémon GO

This article reports a study exploring motivations of Pokémon Game use, individual differences related to personality traits, and game habits. First, it analyzed Pokémon GO motivations through exploratory factor analysis (EFA) by administering online the Pokémon GO Motivational Scale to a group of Italian gamers (N = 560). Successively, a Confirmatory Factor Analysis (CFA) was conducted testing three factorial models of Pokémon Game motivations on a selected random sample (N = 310). Results showed a three-factor model of Pokémon GO Game motivations (i.e. Personal Needs, Social Needs and Recreation), accounting for 68.9% of total variance plus a general higher order factor that best fits the data. Individual differences in Pokémon GO motivations and personality traits have been explored showing that high involved Pokémon GO players are introverted, low agreeableness, and conscientiousness people, driven by personal social and recreational needs. Reciprocal influences on motivational involvement, personality, and game habits were discussed.     

Genetic Carriers and Genomic Distribution of cadA6—A Novel Variant of a Cadmium Resistance Determinant Identified in Listeria spp.

Listeria monocytogenes is a pathogen responsible for severe cases of food poisoning. Listeria spp. strains occurring in soil and water environments may serve as a reservoir of resistance determinants for pathogenic L. monocytogenes strains. A large collection of Listeria spp. strains (155) isolated from natural, agricultural, and urban areas was screened for resistance to heavy metals and metalloids, and the presence of resistance determinants and extrachromosomal replicons. Of the tested strains, 35% were resistant to cadmium and 17% to arsenic. Sequence analysis of resistance plasmids isolated from strains of Listeria seeligeri and Listeria ivanovii, and the chromosome of L. seeligeri strain Sr73, identified a novel variant of the cadAC cadmium resistance efflux system, cadA6, that was functional in L. monocytogenes cells. The cadA6 cassette was detected in four Listeria species, including strains of L. monocytogenes, isolated from various countries and sources—environmental, food-associated, and clinical samples. This resistance cassette is harbored by four novel composite or non-composite transposons, which increases its potential for horizontal transmission. Since some cadAC cassettes may influence virulence and biofilm formation, it is important to monitor their presence in Listeria spp. strains inhabiting different environments.     

A comparison of transformation methods for evaluating two‐dimensional weakly singular integrals

Accurate numerical evaluation of integrals arising in the boundary element method is fundamental to achieving useful results via this solution technique. In this paper, a number of techniques are considered to evaluate the weakly singular integrals which arise in the solution of Laplace's equation in three dimensions and Poisson's equation in two dimensions. Both are two‐dimensional weakly singular integrals and are evaluated using (in a product fashion) methods which have recently been used for evaluating one‐dimensional weakly singular integrals arising in the boundary element method. The methods used are based on various polynomial transformations of conventional Gaussian quadrature points where the transformation polynomial has zero Jacobian at the singular point. Methods which split the region of integration into sub‐regions are considered as well as non‐splitting methods. In particular, the newly introduced and highly accurate generalized composite subtraction of singularity and non‐linear transformation approach (GSSNT) is applied to various two‐dimensional weakly singular integrals. A study of the different methods reveals complex relationships between transformation orders, position of the singular point, integration kernel and basis function. It is concluded that the GSSNT method gives the best overall results for the two‐dimensional weakly singular integrals studied. Copyright © 2002 John Wiley & Sons, Ltd.     

Quantal release at a neuronal nicotinic synapse from rat adrenal gland

The neuronal nicotinic synapse in tissue slices of the adrenal medulla was studied with whole-cell patch-clamp. Excitatory postsynaptic currents (EPSCs) were evoked by local field stimulation or occurred spontaneously especially when external [K+] was increased. EPSCs were carried by channels sharing biophysical and pharmacological properties of neuronal-type nicotinic receptors (nAChRs). A single-channel conductance (gamma) of 43-45 pS was found from nonstationary variance analysis of EPSCs. Spontaneous EPSCs were tetrodotoxin-insensitive and Ca(2+)-dependent and occurred in burst-like clusters. Quantal analysis of spontaneous EPSCs gave a quantal size of 20 pA and amplitude histograms were well described by binomial models with low values of quantal content, consistent with a small number of spontaneously active release sites. However, rare large amplitude EPSCs suggest that the total number of sites is higher and that extrajunctional receptors are involved. Our estimates of quantal content and size at the chromaffin cell neuronal nicotinic synapse may be useful in characterizing central neuronal-type nicotinic receptor-mediated cholinergic synaptic transmission.     

Dynamic and equilibrium swelling of DVB-crosslinked polystyrene particles

The dynamic and equilibrium swelling behavior of polystyrene microparticles crosslinked with divinyl benzene was investigated in methyl ethyl ketone and cyclohexane. The dynamic studies gave new information about the mechanism of penetrant transport in this polymer. The equilibrium studies were used to determine important parameters of the crosslinked structure of these systems, including the average molecular weight between crosslinks, M?_c     

Sexual functioning among breast cancer, gynecologic cancer, and healthy women.

Determined the specific type of sexual functioning deficits and the relationship between global sexual satisfaction and adjustment in 2 related life areas (marital relationship and body image) for 2 groups of cancer patients at high risk for sexual difficulties. The 2 groups included 16 27–67 yr old females with Stage 2 breast cancer and 16 31–65 yr old females with gynecologic cancer. These Ss were compared to 16 healthy female outpatients (controls). Measures included the Sexual Activities scale from the Derogatis Sexual Functioning Inventory, a modified version of the Dyadic Assessment Scale (marital adjustment), a global sexual evaluation, and a body-image scale. Analyses revealed that the aspects of sexual functioning for breast-cancer and gynecologic-cancer Ss that differed from those of controls were the frequency of sexual behaviors and the level of sexual arousal. Whereas Ss' evaluations of their current sexual life had no relationship to their marital-adjustment ratings, analyses suggested that body-image disruption may be a prevalent problem for gynecologic cancer patients. Data suggest that cancer diagnosis and treatment are instrumental in producing reductions in sexual activity and arousability. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing principal stratification and selection models in parametric causal inference with nonignorable missingness

Two approaches for dealing with “endogenous selection” problems when estimating causal effects are considered. They are principal stratification and selection models. The main goal is to highlight similarities and differences between the two approaches, by investigating the different nature of their parametric hypotheses. The principal stratification approach focuses on information contained in specific subgroups of units. The aim is to produce valid inference conditional on such subgroups, without an a priori extension of the results to the whole population. Selection models, on the contrary, aim at estimating parameters that should be valid for the whole population, as if the data come from random sampling. A simulation study is conducted to show their different performances, with data generating processes coming from either approach. It is also argued that principal stratification is able to suggest alternative identification strategies not always easily translatable into assumptions of a selection model.     

The effects of widowhood on physical and mental health, health behaviors, and health outcomes: The Women's Health Initiative.

This study examined whether widowhood was associated with physical and mental health, health behaviors, and health outcomes using a cross-sectional (N=72,247) and prospective (N=55,724) design in women aged 50-79 years participating in the Women's Health Initiative observational study (85.4% White). At baseline, married women reported better physical and mental health and generally better health behaviors than widowed women. Whereas women who remained married over the 3-year period showed stability in mental health, recent widows experienced marked impairments and longer term widows showed stability or slight improvements. Both groups of widows reported more unintentional weight loss over the 3-year period. Changes in physical health and health behaviors were inconsistent, with generally small effect sizes. Findings underscore the resilience of older women and their capacity to reestablish connections, but point to the need for services that strengthen social support among women who have difficulty during this transition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)