Parental Control over Mate Choice to Prevent Marriages with Out-group Members

The present research examined how a preference for influencing the mate choice of one's offspring is associated with opposition to out-group mating among parents from three ethnic groups in the Mexican state of Oaxaca: mestizos (people of mixed descent, n?=?103), indigenous Mixtecs (n?=?65), and blacks (n?=?35). Nearly all of the men in this study were farmworkers or fishermen. Overall, the level of preferred parental influence on mate choice was higher than in Western populations, but lower than in Asian populations. Only among the Mixtecs were fathers more in favor of parental influence on the mate choice of children than mothers were. As predicted, opposition to out-group mating was an important predictor of preferred parental influence on mate choice, more so among fathers than among mothers, especially in the mestizo group-the group with the highest status. In addition, women, and especially mestizo women, expressed more opposition to out-group mating than men did.     

Chlorophyll fluorescence as a tool for evaluation of drought stress in strawberry

The effect of water deficit on chlorophyll fluorescence, sugar content, and growth parameters of strawberry (Fragaria×ananassa Duch. cv. Elsanta) was studied. Drought stress caused significant reductions in leaf water potential, fresh and dry masses, leaf area, and leaf number. A gradual reduction of photochemical quenching (q_P) and quantum efficiency (Φ_PS2) was observed under drought stress while non-photochemical quenching (q_N) increased. Maximum efficiency of photosystem 2 (F_v/F_m) was not affected by drought stress.     

Dolichopodid Biodiversity and Site Quality Assessment of Reed Marshes And Grasslands in Belgium (Diptera: Dolichopodidae)

The conservation value of grassland and reed marsh habitats in Belgium was determined on the basis of dolichopodid communities (Diptera: Dolichopodidae). Four grassland and one reed marsh sites within the 'Bourgoyen-Ossemeersen' Nature Reserve (B.O.) (Ghent) were sampled with white water traps from March 1993 until March 1994. Subsequently, these soil faunas were compared with those of reed marsh habitats in 'Het Meetjeslandse Krekengebied' (M.K.) sampled in 1990. Comparisons of species communities were carried out by means of multivariate analysis techniques. The DCA and CCA on the B.O. sites produced a clear separation between the grassland and the reed marsh communities. Light intensity and soil humidity were among the most important factors determining species distributions. The comparison between the B.O. and M.K. communities revealed that sampling sites were clustered according to their geographical location rather than to habitat type. Overall species richness and diversity was not significantly different between grasslands and reed marshes. However, conservation quality estimates of the sites using the Site Conservation Quality Index (SCQI) indicated that reed marshes comprise a considerably larger number of rare and Red Data Book species. Moreover, besides typical reed marsh-inhabiting species, reed marshes also house species with other ecological affinities sometimes in rather high abundance. As a result, reed marshes are considered highly valuable for the survival of several wetland dolichopodid species.     

Equilibrium model for insulin-induced receptor down-regulation. Regulation of insulin receptors in differentiated BC3H-1 myocytes

The mechanism of insulin-induced down-regulation of surface membrane insulin receptors was studied in the muscle cell line BC3H-1. Down-regulation for the differentiated myocytes is dose- and time-dependent with a half-maximum response at 0.5 nM insulin and a maximum decrease of 50% in the number of surface insulin receptors following exposure to 20 nM insulin for 18 h at 37 degrees C, as confirmed by Scatchard analysis. These receptors were fully recoverable upon lysis of the down-regulated myocyte with Triton X-100, demonstrating that down-regulation is mediated solely by insulin-induced receptor internalization without detectable receptor degradation. Phospholipase C treatment of intact down-regulated cells and Triton X-100 treatment after subcellular fractionation showed that no cryptic or masked receptors were detectable within the plasma membrane. Insulin-induced receptor internalization was dependent upon cellular energy production, protein synthesis, and endocytosis, but was insensitive to agents which primarily affect lysosomal, cytoskeletal, or transglutaminase activities. The magnitude of insulin-induced down-regulation and the kinetics of down-regulation and recovery of cell surface receptors indicate that the surface and internal receptor pools are in dynamic equilibrium with each other. The kinetic data are accommodated by separate internalization rate constants for the unoccupied (0.01 h-1) and occupied (0.11 h-1) surface receptors and a single recycling rate constant (0.11 h-1) for the internalized receptors. This model also explains the previous apparently paradoxical finding in several other systems that down-regulation is more sensitive to hormone than hormone-receptor binding under physiologic conditions. Down-regulation in BC3H-1 myocytes, therefore, appears to be mediated solely by an insulin-induced increase in the receptor internalization rate constant and a consequent shift in the dynamic equilibrium between the surface and internalized receptor pools, resulting in a 50% decrease in the number of cell surface receptors. In other systems where the internalized hormone receptor is a substrate for rapid degradation, the essential role of this shift in mediating the down-regulation process may be obscured.     

Coenzyme Q10, a cutaneous antioxidant and energizer.

The processes of aging and photoaging are associated with an increase in cellular oxidation. This may be in part due to a decline in the levels of the endogenous cellular antioxidant coenzyme Q10 (ubiquinone, CoQ10). Therefore, we have investigated whether topical application of CoQ10 has the beneficial effect of preventing photoaging. We were able to demonstrate that CoQ10 penetrated into the viable layers of the epidermis and reduce the level of oxidation measured by weak photon emission. Furthermore, a reduction in wrinkle depth following CoQ10 application was also shown. CoQ10 was determined to be effective against UVA mediated oxidative stress in human keratinocytes in terms of thiol depletion, activation of specific phosphotyrosine kinases and prevention of oxidative DNA damage. CoQ10 was also able to significantly suppress the expression of collagenase in human dermal fibroblasts following UVA irradiation. These results indicate that CoQ10 has the efficacy to prevent many of the detrimental effects of photoaging.     

Mortality in over 350,000 Insured Swedish Dogs from 1995–2000: II. Breed-Specific Age and Survival Patterns and Relative Risk for Causes of Death

This study continues analysis from a companion paper on over 350,000 insured Swedish dogs up to 10 years of age contributing to more than one million dog-years at risk during 1995–2000. The age patterns for total and diagnostic mortality and for general causes of death (trauma, tumour, locomotor, heart and neurological) are presented for numerous breeds. Survival estimates at five, eight and 10 years of age are calculated. Survival to 10 years of age was 75% or more in Labrador and golden retrievers, miniature and toy poodles and miniature dachshunds and lowest in Irish wolfhounds (91% dead by 10 years). Multivariable analysis was used to estimate the relative risk for general and more specific causes of death between breeds accounting for gender and age effects, including two-way interactions. Older females had tumour as a designated cause of death more often than males in most breeds, but not in the Bernese mountain dog. Information presented in this and the companion paper inform our understanding of the population level burden of disease, and support decision-making at the population and individual level about health promotion efforts and treatment and prognosis of disease events.     

Minimum information specification for in situ hybridization and immunohistochemistry experiments (MISFISHIE)

One purpose of the biomedical literature is to report results in sufficient detail that the methods of data collection and analysis can be independently replicated and verified. Here we present reporting guidelines for gene expression localization experiments: the minimum information specification for in situ hybridization and immunohistochemistry experiments (MISFISHIE). MISFISHIE is modeled after the Minimum Information About a Microarray Experiment (MIAME) specification for microarray experiments. Both guidelines define what information should be reported without dictating a format for encoding that information. MISFISHIE describes six types of information to be provided for each experiment: experimental design, biomaterials and treatments, reporters, staining, imaging data and image characterizations. This specification has benefited the consortium within which it was developed and is expected to benefit the wider research community. We welcome feedback from the scientific community to help improve our proposal.     

New approach to elaborate exfoliated starch-based nanobiocomposites

The present paper reports the successful elaboration of exfoliated plasticized starch-based nanobiocomposites. This was made possible by using cationic starch as a new clay organomodifier to better match the polarity of the matrix and thus to facilitate the clay exfoliation process. To demonstrate the efficiency of this new approach, either natural (MMT-Na) or organomodified (OMMT-CS) montmorillonite were incorporated into the starch nanobiocomposites by a melt blending process. The morphological analyses (SAXD and TEM) showed that MMT-Na leads to the formation of intercalated nanobiocomposites. On the contrary, OMMT-CS allowed the elaboration of well-exfoliated nanobiocomposites. Tensile tests performed on the obtained nanobiocomposites showed that exfoliated nanobiocomposites display enhanced mechanical properties compared to those of the intercalated nanobiocomposites and neat matrix. These results clearly highlight the great interest in using OMMT-CS to obtain starch-based nanobiocomposites with improved properties.     

Prokaryotic aminopeptidase activity along a continuous salinity gradient in a hypersaline coastal lagoon (the Coorong, South Australia)

The relation between climatic parameters (relative air humidity) and the water activity of the Urmia Sea water determines the possible maximum evaporation of the lake. Using the Pitzer thermodynamic approach, the activity of the Urmia Lake water during evaporation was calculated and compared to the present relative air humidity above the water. Present climatic conditions allow the Urmia Sea water to evaporate down to water with activity of 0.55, corresponding to the lowest air humidity measured over the lake. This water activity falls in the range of halite precipitation, while carnalite precipitation starts at somewhat lower (a H₂O = 0.499) point. Our dynamic model predicts that for air humidity as low as 55% (reflecting present climate conditions), the Urmia Sea level may drop to as low as 1270 m (i. e., 1270 m above mean sea level). At that point, the lake water volume will have a volume of 11 km³. For the sake of comparison, at the beginning of 1990, the level of the lake was 1275 m, its volume was 25 km³, and its surface area was 5145 km².