Effective size of an Atlantic salmon (Salmo salar L.) metapopulation in Northern Spain

The genetic diversity of metapopulations is influenced not only by the effective sizes (N _e ) of individual subpopulations, but also by the total effective size of the metapopulation (meta-N _e ). We estimated meta-N _e of four neighbouring Atlantic salmon populations connected by gene flow using genetic estimates of subpopulation N _e s and migration rates derived from capture–recapture data. The meta-[^(N)]_e meta{\hbox{-}}\hat{N}_{e} was lower than the sum of [^(N)]_e \hat{N}_{e} s of the subpopulations, suggesting that genetic diversity harboured by the four river salmon metapopulation is lower than what would have been expected by viewing individual subpopulations separately. In addition, meta-[^(N)]_e meta{\hbox{-}}\hat{N}_{e} was found to be sensitive to changes in [^(N)]_e \hat{N}_{e} of the subpopulation from which net emigration rate was largest, so as that the genetic diversity of the metapopulation would be best preserved by avoiding any reductions in N _e of this subpopulation. Yet, this subpopulation is the one that has historically—and still is—experiencing the highest exploitation rate in the metapopulation system.     

Purification of human IgG by negative chromatography on ω-aminohexyl-agarose

The ω-aminohexyl diamine immobilized as ligand on CNBr- and bisoxirane-activated agarose gel was evaluated for the purification of human immunoglobulin G (IgG) from serum and plasma by negative affinity chromatography. The effects of matrix activation, buffer system, and feedstream on recovery and purity of IgG were studied. A one-step purification process using Hepes buffer at pH 6.8 allowed a similar recovery (69–76%) of the loaded IgG in the nonretained fractions for both matrices, but the purity was higher for epoxy-activated gel (electrophoretically homogeneous protein with a 6.5-fold purification). The IgG and human serum albumin (HSA) adsorption equilibrium studies showed that the adsorption isotherms of IgG and HSA obeyed the Langmuir–Freundlich and Langmuir models, respectively. The binding capacity of HSA was high (210.4 mg mL^?1 of gel) and a positive cooperativity was observed for IgG binding. These results indicate that immobilizing ω-aminohexyl using bisoxirane as coupling agent is a useful strategy for rapid purification of IgG from human serum and plasma.     

Effect of Pedoclimatic Conditions on the Chemical Composition of the Sigoise Olive Cultivar

The present work focused on the quality and the chemical composition of monovarietal virgin olive oil from the Sigoise variety grown in two different locations in Tunisia, viz., a sub‐humid zone (Béjaoua, Tunis) and an arid zone (Boughrara, Sfax). In addition to the quality characteristics (acidity, peroxide value, and the spectrophotometric indices K232 and K270) and the chemical composition (content of fatty acids, antioxidants, and volatile compounds) of the oil, the fruit characteristics of the olives were studied. Except for the content of the majority of the fatty acids, there were significant differences observed in the oil composition of olives that were cultivated in different locations. The content of total phenols and lipoxygenase (LOX) oxidation products was higher for olives grown at the higher altitude, whereas that of α‐tocopherol, carotenes, and chlorophylls was higher for olives from the Boughrara region (lower altitude). Moreover, olives produced at the higher altitude showed a higher ripeness index and oil content than those cultivated at the lower altitude.     

Human Bone Marrow Mesenchymal Stem Cells Display Anti-Cancer Activity in SCID Mice Bearing Disseminated Non-Hodgkin's Lymphoma Xenografts

Background

Although multimodality treatment can induce high rate of remission in many subtypes of non-Hodgkin''s lymphoma (NHL), significant proportions of patients relapse with incurable disease. The effect of human bone marrow (BM) mesenchymal stem cells (MSC) on tumor cell growth is controversial, and no specific information is available on the effect of BM-MSC on NHL.

Methodology/Principal Findings

The effect of BM-MSC was analyzed in two in vivo models of disseminated non-Hodgkin''s lymphomas with an indolent (EBV⁻ Burkitt-type BJAB, median survival = 46 days) and an aggressive (EBV⁺ B lymphoblastoid SKW6.4, median survival = 27 days) behavior in nude-SCID mice. Intra-peritoneal (i.p.) injection of MSC (4 days after i.p. injection of lymphoma cells) significantly increased the overall survival at an optimal MSC∶lymphoma ratio of 1∶10 in both xenograft models (BJAB+MSC, median survival = 58.5 days; SKW6.4+MSC, median survival = 40 days). Upon MSC injection, i.p. tumor masses developed more slowly and, at the histopathological observation, exhibited a massive stromal infiltration coupled to extensive intra-tumor necrosis. In in vitro experiments, we found that: i) MSC/lymphoma co-cultures modestly affected lymphoma cell survival and were characterized by increased release of pro-angiogenic cytokines with respect to the MSC, or lymphoma, cultures; ii) MSC induce the migration of endothelial cells in transwell assays, but promoted endothelial cell apoptosis in direct MSC/endothelial cell co-cultures.

Conclusions/Significance

Our data demonstrate that BM-MSC exhibit anti-lymphoma activity in two distinct xenograft SCID mouse models of disseminated NHL.     

Prevalence of periconceptional folic acid use and perceived barriers to the postgestation continuance of supplemental folic acid: survey results from a Teratogen Information Service

BACKGROUND: Fewer than 40% of U.S. women are taking folic acid supplements periconceptionally at a time when the risk of neural tube defects (NTDs) can be reduced by supplementation. A better understanding of the vitamin-taking habits of childbearing-age women and effective methods for improving periconceptional supplement use are needed. METHODS: A telephone survey conducted through the California Teratogen Information Service (TIS) between August 2003 and January 2004 assessed the prevalence and characteristics of pregnant callers who did not use folic acid supplements in the periconceptional period, and explored attitudes toward advice to continue vitamin use following pregnancy in order to be protected in a future pregnancy. RESULTS: A total of 327 pregnant women who called the TIS for information agreed to participate in the survey. More than half (53.2%) were not taking folic acid-containing supplements in the periconceptional period. Predictors of lack of use included a higher prepregnancy body mass index, younger maternal age, non-white race/ethnicity, lower education level, and unplanned pregnancy. One-quarter of the women said they would be willing to continue taking vitamins after the pregnancy if advised to do so by a physician. The remainder identified obstacles to following that advice--notably, not planning to become pregnant again and the belief that enough folate is derived from diet alone. CONCLUSIONS: More than half of the callers to the TIS were not compliant with recommendations regarding periconceptional folic acid supplementation. This represents an opportunity for TIS specialists and physicians to intervene in a current pregnancy to encourage maintenance of supplement use in the subsequent interpregnancy interval.     

Modeling egg distribution of Tinocallis kahawaluokalani (Kirkaldy) (Hemiptera: Aphididae) on Lagerstroemia indica L. (Lythraceae)

This is the first record of winter eggs of the holocyclic monoeceous crapemyrtle aphid Tinocallis kahawaluokalani (Kirkaldy) on Lagerstroemia indica L., in Brazil. The shiny black eggs were observed since early autumn, laid on small folds and crevices of the branches. In order to evaluate and model the egg abundance and distribution, four branches from the cardinal points of 10 plants of two age groups, 5-10 and 20-30 years-old, were collected randomly and cut in eight segments of 10 cm and the number of eggs was registered, in the winter 2001. The eggs were laid mainly on the middle portion of the branch, from 40 cm to 60 cm from the apex on the older trees (54%) and on 30 cm to 60 cm on younger ones (58%). The data fit in a longitudinal regression model that expresses the tendency of the egg distribution on the branches. The number of eggs was greater on the 20-30 year-old plants (61%) than on younger ones (39%). The average number (+/- CI 95%) of eggs was 70.5 +/- 9.3 and 47.4 +/- 12.5, respectively, for the older and younger tree groups. There was no correlation between egg distribution and the cardinal positions of the branches.     

Statistical practice in high-throughput screening data analysis

High-throughput screening is an early critical step in drug discovery. Its aim is to screen a large number of diverse chemical compounds to identify candidate 'hits' rapidly and accurately. Few statistical tools are currently available, however, to detect quality hits with a high degree of confidence. We examine statistical aspects of data preprocessing and hit identification for primary screens. We focus on concerns related to positional effects of wells within plates, choice of hit threshold and the importance of minimizing false-positive and false-negative rates. We argue that replicate measurements are needed to verify assumptions of current methods and to suggest data analysis strategies when assumptions are not met. The integration of replicates with robust statistical methods in primary screens will facilitate the discovery of reliable hits, ultimately improving the sensitivity and specificity of the screening process.     

Heart rate and burrowing behavior in the mussel Anodontites trapesialis (Bivalvia: Mycetopodidae) from lotic and lentic sites

Burrowing rate index, diurnal variations in heart rate and heart rate alterations associated with behavioral patterns were studied in Anodontites trapesialis from the Pardo River (PR) and the Galo Bravo Dam (GBD). In both populations the pattern immobile/buried was associated with the lowest (basal) values of heart rate, which increase significantly during burrowing remaining steady in its phases I and II and at the first 10 min of phase III. A decrease in the frequency of digging cycles was significantly correlated with the gradual decrease in heart rate during the phase III of burrowing. Nevertheless, mussels from PR burrow faster than those of GBD and possess higher values of basal heart rate which present a diurnal variation with the higher values occurring during the light phase. Yet, the basal heart rate in mussels from GBD remained stable over the course of 24 h. Also, the increase in heart rate associated with burrowing was higher in mussels from PR and compatible with the highest burrowing index previously detected. Since mussels possess a plastic phenotype it is probable that the cited functional differences are phenotypic adaptations, but we cannot exclude the possibility of these adaptations being genotypic in nature.