Opposite effects of environmental variability and species richness on temporal turnover of species in a complex habitat mosaic

Species are continuously lost and added to a local community. Dynamics of this process in a complex habitat mosaic (multiple habitats in a landscape), particularly of its rates (species turnover) are of primary concern for biodiversity conservation. Various studies suggest that species traits such as habitat specialization should affect species turnover. In communities where habitat specialization is a function of abiotic constraints, habitat specialists should respond faster to changing environment than generalists. We thus predicted a higher temporal turnover for specialists than for generalists in the presence of environmental variability (EV). In addition, we predicted that temporal turnover should decrease with increasing species richness of the communities they live in. We tested these predictions in a model system of 49 natural rock pools inhabited by 70 invertebrate species for which long-term (9 years) environmental and population dynamics data are available. We computed standard deviation of salinity measurements to represent EV for each pool. We further obtained the number of combined colonization and extinction events weighted by the number of years a species was recorded as a temporal turnover for each species in individual pools. We found that EV induced greater temporal turnover, however, the turnover depended on the species habitat traits (habitat specialization)—it has been higher in specialists but that relationship between EV and temporal turnover dissolved with increasing niche breadth (generalists). We further found that for some species, temporal turnover decreased with higher species richness and for other species, temporal turnover increased with higher species richness. The effect of species richness on temporal turnover was unrelated to species traits. This study suggests that whenever habitat is complex and heterogeneous and species pool diversified, local community dynamics becomes a composite of differential responses.     

Association of the -14C/G MET and the -765G/C COX-2 gene polymorphisms with the risk of chronic rhinosinusitis with nasal polyps in a Polish population

Chronic rhinosinusitis with nasal polyps is strongly associated with other diseases, including asthma and allergy. The following study tested the association of the -765 G/C polymorphism of cyclooxygenase-2 (COX-2) encoding gene and the -14C/G polymorphism of protooncogen MET (MET) encoding gene with a risk of chronic rhinosinusitis with nasal polyps in a Polish population. One hundred ninety-five patients of chronic rhinosinusitis with nasal polyps as well as 200 sex-, age-, and ethnicity-matched control subjects without chronic sinusitis and nasal polyps were enrolled in this study. Among the group of patients, 63 subjects were diagnosed with allergy and 65 subjects with asthma, respectively. DNA was isolated from peripheral blood lymphocytes of patients as well as controls, and gene polymorphisms were analyzed by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). Ten percent of the samples have been confirmed by a second method single-strand conformation polymorphism (SSCP)-PCR. We reported that the -765 G/C COX-2 (odds ratio [OR] 7.79; 95% confidence interval [CI] 4.88-12.4, p<0.001) and the -14C/G MET (OR 2.83; 95% CI 1.74-4.61, p<0.001) were associated with an increased risk of chronic rhinosinusitis with nasal polyps among analyzed group of patients. Moreover, the group of patients without allergy or asthma indicated the association of the -765 C/G (OR 7.25; 95% CI 4.38-12.1, p<0.001 and OR 7.61; 95% CI 4.47-12.6, p<0.001) genotype of the COX-2 as wells as the -14C/G (OR 2.47; 95% CI 1.46-4.17, p<0.001 and OR 2.59; 95% CI 1.54-4.37, p<0.001) genotype of MET with an increased risk of chronic rhinosinusitis with nasal polyps. Finally, it was also found that the selected group of patients with allergy or asthma indicated a very strong association of the -765 G/C (OR 5.64; 95% CI 2.91-10.9 and OR 4.74; 95% CI 2.49-9.03, p<0.001, respectively) genotype of the COX-2 with an increased risk of chronic rhinosinusitis with nasal polyps. Thus, our results suggest that COX-2 and MET gene polymorphisms may have deep impact on the risk of rhinosinusitis nasal polyp formation, which may also depend on asthma or allergy. Our results showed that the -765 G/C polymorphism of COX-2 gene and the -14C/G polymorphism of the MET gene may be associated with the risk of chronic rhinosinusitis with nasal polyps in a Polish population.     

The composite nature of the interaction between nuclear receptors EcR and DHR38

Ecdysteroids coordinate essential biological processes in Drosophila through a complex of two nuclear receptors, the ecdysteroid receptor (EcR) and the ultraspiracle protein (Usp). Biochemical experiments have shown that, in contrast to Usp, the EcR molecule is characterized by high intramolecular plasticity. To investigate whether this plasticity is sufficient to form EcR complexes with nuclear receptors other than Usp, we studied the interaction of EcR with the DHR38 nuclear receptor. Previous in vitro experiments suggested that DHR38 can form complexes with Usp and thus disrupt Usp-EcR interaction with the specific hsp27pal response element. This article provides the experimental evidence that EcR is able to form complexes with DHR38 as well. The recombinant DNA-binding domains (DBDs) of EcR and DHR38 interact specifically on hsp27pal. However, the interaction between the receptors is not restricted to their isolated DBDs. We pre\xadsent data that indicate that the full-length EcR and DHR38 can also form specific complexes within the nuclei of living cells. This interaction is mediated by the hinge region of EcR, which was recently classified as an intrinsically disordered region. Our results indicate that DHR38 might modulate the activity of the Usp-EcR heterodimer by forming complexes with both of its components.     

Synthesis and evaluation of 3-aryl piperidine analogs as potent and efficacious dopamine D4 receptor agonists

A series of 3-aryl piperidine analogs with 2-piperidinoalkylamino or 2-piperidinoalkyloxy fused bicyclic rings were prepared and found to be potent and efficacious human dopamine D4 agonists. The synthesis and structure-activity relationship (SAR) studies that led to the identification of these compounds are discussed.     

New records for two mosquito predators [Turbellaria: Mesostoma] in the northeastern United States

The accumulated data indicate that mesostomid flatworms are efficient predators of mosquito larvae. This paper presents the 1st published records for 3Mesostoma Ehrenberg, including 2 predators of mosquitoes.Mesostoma californicum Hyman,Mesostoma vernale Hyman, andMesostoma sp. cf.lingua Abildgaard were discovered in a temporary pool in Massachusetts.M. californicum andM. sp. cf.lingua were found to be efficient predators on mosquitoe larvae.

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Résumé Les observations accumulées indiquent que les larves des Plathelminthes mesostomides sont des prédateurs efficaces des larves de moustiques. Cette note présente les premières mentions de 3Mesostoma Ehrenberg incluant 2 prédateurs de moustiques.Mesostoma californicum Hyman,Mesostoma vernale Hyman, etMesostoma sp. cf.lingua Abildgaard furent découverts dans une mare temporaire du Massachusetts.M. californicum etM. sp. cf.lingua ont été reconnus comme des prédateurs efficaces des larves de moustiques.

     

Interaction of biofeedback-assisted relaxation and diuretic in treatment of essential hypertension

Thirty patients with essential hypertension participated in a study designed to compare two treatments: diuretic medication alone (n=10) and biofeedback assisted relaxation combined with diuretic (n=20). One of 10 patients lowered BP with diuretic alone and 11 of 20 patients lowered BP with diuretic combined with biofeedback-assisted relaxation. The addition of the behavioral intervention to the diuretic therapy produced a decrease in blood pressure beyond that associated with the diuretic alone. The decreases in BP mediated by diuretic were related to high entry levels of BP, low anxiety, forehead muscle tension, anger expression and plasma renin activity. The BP decrease mediated by combined diuretic and biofeedback-assisted relaxation was associated with high pretreatment BP, anger controlled, low finger temperature and high/normal plasma renin activity.This work supported by the Northwestern Ohio Heart Association under grant No. 93132 to Dr. McGrady.     

Extracellular Reduction of Cat1 Free Radical by Transformed Human Hepatocytes

Redox activities associated with plasma membranes of nonphagocytic animal and plant cells have been reported by several authors. However, the natural substrates, structure and biological role of these putative enzyme systems are not known. Data indicating extracellular reduction of a nitroxide free radical Cat1 (1-oxy-4-trimethylamine-2,2,6,6,tetramethyl-piperidine) by hepatocytes were thought to be artefactual. We report evidence in support of a notion that Cat1 as well as a tetrazolium salt, CTC (5-cyano-2,3-ditolyl tetrazolium chloride), are reduced extracellularly, probably at the cell surface, by human HepG2 hepatoma cells. These data provide evidence confirming the existence of a yet unidentified reducing activity associated with outer surface of plasma membranes of transformed human hepatocytes.     

Hyaluronan-mediated angiogenesis in vascular disease: uncovering RHAMM and CD44 receptor signaling pathways.

The correct formation of new blood vessels from existing vasculature (angiogenesis) is essential for embryogenesis and the effective repair of damaged or wounded tissues. However, excessive and detrimental vascularization also occurs in neoplasia, promoting tumour growth and metastasis, as well as in proliferative diabetic retinopathy and atherosclerosis. Greater understanding of the mechanisms controlling the angiogenic process will allow optimization of wound healing, and provide mechanisms to inhibit vascularization in tumours and other diseases. Evidence supports a cascade of events in which the perturbation of one of the steps is sufficient to significantly inhibit neovascularization. The extracellular macromolecules, notably glycosaminoglycans (GAGs), are important mediators of angiogenesis. Hyaluronan (HA), a large, non-sulphated GAG, was first discovered in the vitreous of the eye [.], and is ubiquitously expressed in the extracellular matrix (ECM) of tissues. Native high molecular weight HA (n-HA) is anti-angiogenic, whereas HA degradation products (o-HA; 3-10 disaccharides) stimulate endothelial cell (EC) proliferation, migration and tube formation following activation of specific HA receptors in particular, CD44 and Receptor for HA-Mediated Motility (RHAMM, CD168). The involvement of HA in the regulation of angiogenesis makes it an attractive therapeutic target. We review the role of o-HA in modulation of angiogenesis during tissue injury, and vascular disease, focusing on receptor-mediated signal transduction pathways that have been evaluated.     

Biogeographic variation in coral species diversity on coral reefs in three regions of Indonesia

Abstract . This paper assesses variation in coral species diversity within the Indonesian archipelago, and the influence of regional species pools, geomorphology and anthropogenic pollution on coral species diversity and occurrence. We obtained transects from 33 sites on 14 reefs in three regions of Indonesia: Ambon (Moluccas), South Sulawesi and the Java Sea. We determined the within‐site species richness by using species‐sampling curves. Cluster analysis and multi‐dimensional scaling showed that land‐based pollution was the primary determinant of coral species diversity and species occurrence on reefs. Relatively unaffected reference sites in eastern Indonesia were approximately 20% more diverse than Java Sea reference sites. Rare species formed a higher proportion of the coral fauna on eastern Indonesian sites, and eastern Indonesian apparent endemic species contributed approximately 25% of the total species pool sampled. Between‐site variation in species occurrence was lower on Java Sea reefs than on eastern Indonesian reefs. A larger species pool in eastern Indonesia than in the Java Sea probably accounted for most of the difference in within‐site species diversity between eastern Indonesian and Java Sea reference sites. High fishing intensity in the Java Sea, including destructive fishing practices, may have also contributed to reduced within‐site species diversity on Java Sea reference reefs. Despite the fact that the Java Sea was exposed during Pleistocene lowstands, and was recolonized by marine organisms only within the last 10 000 years, coral species diversity and assemblage composition on the Java Sea reefs was largely similar to open ocean reefs in eastern Indonesia.