Biotransfer, Bioaccumulation and Effects of Herbivore Dietary Co, Cu, Ni, and Zn on Growth and Development of the Insect Predator Podisus maculiventris (Say)

Increased metal availability in the environment can be detrimental for the growth and development of all organisms in a food web. In part, this toxicity is due to biotransfer or bioaccumulation of metals between trophic levels. We evaluated the survival, growth, and development of a generalist Hemipteran predator (Podisus maculiventris) when fed herbivorous prey (Spodoptera exigua) reared on artificial diet amended with Cu, Zn, Ni, and Co. Predator nymphs were fed S. exigua larvae raised on diet amended with sublethal (Minimum Sublethal Concentration or MSC) or lethal (Minimum Lethal Concentration or MLC) concentrations of each metal, as well as control diet. We determined if metals were biotransferred or bioaccumulated from the diet to herbivore and predator, as well as if predator growth or survival was affected by herbivore diet. Podisus maculiventris fed herbivores raised on MLC levels of both Cu and Zn took significantly longer to mature to adults, whereas their overall survival was not affected by prey diet metal concentration for any metal. Adult weights were significantly reduced for predators raised on herbivores reared on diets amended with the MLC of Cu and Zn. Copper and Zn were bioaccumulated from diet to herbivore and from herbivore to predator, whereas Ni was biotransferred (although concentrations decreased as trophic level increased). The pattern for Co was more complex, with biotransfer the main outcome. Our results show that availability of metals in a food web can affect growth and development of a hemipteran predator, and that metals are transferred between trophic levels, with metal-specific biotransfer and bioaccumulation outcomes.     

Pushing the Boundaries of Structural Heterogeneity with the Lipid A of Marine Bacteria Cellulophaga

Marine bacteria, which are often described as chemical gold, are considered an exceptional source of new therapeutics. Considerable research interest has been given to lipopolysaccharides (LPSs), the main components of the Gram-negative outer membrane. LPS and its lipid A portion from marine bacteria are known to exhibit a tricky chemistry that has been often associated with intriguing properties such as behaving as immune adjuvants or anti-sepsis molecules. In this scenario, we report the structural determination of the lipid A from three marine bacteria within the Cellulophaga genus, which showed to produce an extremely heterogenous blend of tetra- to hexa-acylated lipid A species, mostly carrying one phosphate and one D-mannose on the glucosamine disaccharide backbone. The ability of the three LPSs in activating TLR4 signaling revealed a weaker immunopotential by C. baltica NNO 15840^T and C. tyrosinoxydans EM41^T, while C. algicola ACAM 630^T behaved as a more potent TLR4 activator.     

Multiple paths to nanocrystalline high silica beta zeolite

Several principles from nanozeolite synthesis lore were investigated in order to prepare discrete pure silica nanocrystalline BEA zeolite. It was discovered that lowering reaction temperature to 100 °C results in a significant reduction in nano-BEA crystal size, that lowering synthesis mixture water content to the lowest possible level for a ‘pourable’ gel provides nano-BEA crystals, that tetraethylorthosilicate (TEOS) more consistently provides smaller crystals than fumed silica as a raw material, that increasing the level of structure-directing agent resulted in more discrete and smaller crystals (25–30 nm), and that ‘surfactant’ addition could generate even smaller nano-BEA crystals or nanocrystalline domains, but mild to severe aggregation was still a problem. Nearly pure silica nanocrystalline BEA zeolites were prepared from Al-containing products by a calcination followed by acid extraction procedure. The calcination step is critical for more complete Al removal. Defects generated by acid extraction could be healed by treatment of resultant powder with a hexamethyldisilazane (HMDS). Another key finding was that Al-containing synthesis mixtures could provide nanocrystalline BEA zeolite with 4,4′-trimethylenebis(N-methyl, N-benzyl-piperidinium) dihydroxide (TMP(OH)₂) as organic structure-directing agent. Interestingly, adjusting synthesis parameters in TMP and Al-containing synthesis mixtures provided some differences to pure Si BEA products. For example, stirring or lowering reaction temperature did not decrease crystal size, but did shorten crystallization time. The smallest crystals from TMP-based, Al-containing reaction mixtures were prepared when a freeze–dried colloidal silica was utilized as silica source.     

Interventions to increase use of nicotine gum: a randomized, controlled, single-blind trial.

Medication noncompliance with smoking cessation pharmacotherapies is a significant problem in both research and clinical settings. This randomized, controlled, single-blind study compared three single-session psychological interventions to increase use of nicotine gum during a 15-day treatment period. A total of 97 adult smokers were randomized to receive standard treatment (ST, n = 31), brief feedback (BF, n = 32) plus ST, or contingency management (CM; i.e., payment for chewing at least 12 pieces/day on 10 of 15 intervention days, n = 34) plus ST and BF. Only the CM condition led to significantly greater average daily gum use (pieces/day: ST, 6.17; BF, 7.81; CM, 10.17 [p values <.05]) and higher rates of compliance (ST, 13.6%; BF, 25.2%; CM, 65.6% [p values <.001]). No differences were observed in smoking abstinence, nicotine withdrawal, or urinary cotinine as a function of treatment. Implications of the present findings are discussed, including application to clinical trials and extension to real-world use of nicotine gum.     

Evaluation of the Effect of the Fibroblast Growth Factor Type 2 (FGF-2) Administration on Placental Gene Expression in a Murine Model of Preeclampsia Induced by L-NAME

The abnormal implantation of the trophoblast during the first trimester of pregnancy precedes the appearance of the clinical manifestations of preeclampsia (PE), which is a hypertensive disorder of pregnancy. In a previous study, which was carried out in a murine model of PE that was induced by NG-nitro-L-arginine methyl ester (L-NAME), we observed that the intravenous administration of fibroblast growth factor 2 (FGF2) had a hypotensive effect, improved the placental weight gain and attenuated the fetal growth restriction, and the morphological findings that were induced by L-NAME in the evaluated tissues were less severe. In this study, we aimed to determine the effect of FGF2 administration on the placental gene expression of the vascular endothelial growth factor (VEGFA), VEGF receptor 2 (VEGFR2), placental growth factor, endoglin (ENG), superoxide dismutase 1 (SOD1), catalase (CAT), thioredoxin (TXN), tumor protein P53 (P53), BCL2 apoptosis regulator, Fas cell surface death receptor (FAS), and caspase 3, in a Sprague Dawley rat PE model, which was induced by L-NAME. The gene expression was determined by a real-time polymerase chain reaction using SYBR green. Taking the vehicle or the L-NAME group as a reference, there was an under expression of placental VEGFA, VEGFR2, ENG, P53, FAS, SOD1, CAT, and TXN genes in the group of L-NAME + FGF2 (p < 0.05). The administration of FGF2 in the murine PE-like model that was induced by L-NAME reduced the effects that were generated by proteinuria and the increased BP, as well as the response of the expression of genes that participate in angiogenesis, apoptosis, and OS. These results have generated valuable information regarding the identification of molecular targets for PE and provide new insights for understanding PE pathogenesis.     

Value of cultural pluralism to the generalizability of psychological theories: A reexamination.

Argues that the limited generalizability of psychological theories and hypotheses may stem, in part, from a restricted sampling of psychological theorists and investigators and hence from the homogeneity of their background assumptions, biases, and values. Threats to generalizability at the hypothesis-testing, theory-development, and hypothesis-formation stages of research are discussed using examples from the literature. A cultural pluralism approach is recommended for the recruitment and training of socioculturally diverse psychologists, capable of conducting research in a wider variety of settings with a wider range of Ss. Types of short- and long-term location and recruitment techniques are discussed, and the promotion of the cultural pluralism perspective within the graduate curriculum is addressed. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)