Diversity of terrestrial gastropod mollusks in the Pacific region of Nicaragua, and their habitat preferences

Diversity of terrestrial gastropod mollusks in the Pacific region of Nicaragua, and their habitat preferences. Landsnail communities of the Nicaraguan Pacific Slope were studied. The study area was subdivided into 21 quadrats (ca. 40 x 40 km). A high taxonomic richness was found: 79 species, 43 genera and 23 families. Species richness (S) per quadrat ranged from 17 through 50. The biogeographic index presented higher values on quadrats 5 (3.04), 6 (3.03), 8 (2.96) and 11(2.96). Quadrat 11 had the highest species richness (S=50), and one of the highest biogeographic index values (IB=2.96). Gastropod mollusk communities are favored by sites with an illumination of filtered sun, associated to riparian forests and with a susbtratum of wet soils and leaf litter.     

Polychaeta (Annelida) associated with Thalassia testudinum in the northeastern coastal waters of Venezuela

Seasonal variations of polychaetes in a Thalassia testudinum bed were studied from June 2000 to April 2001 in Chacopata, northeastern Venezuela. Eight replicate samples were taken monthly with a 15 cm diameter core and the sediment was passed through a 0.5 mm mesh sieve. A total of 1,013 specimens, belonging to 35 species, was collected. The monthly density ranged from 387 ind/m2 (September) to 1,735 ind/m2 in May (x = 989+/-449 ind/m2). Species richness was lowest in August and September (8) and highest (25) in April (x = 18.00+/-5.29). The shoot density of Thalassia showed an average of 284+/-77.60 shoots/m2, with extreme values in February (164) and May (422). Species diversity ranged from 1.25 in August and 3.33 bits/ind in December (x = 2.47+/-0.64). Significant positive correlations were detected among the number of Thalassia shoots, polychaete abundance and species richness, as well as among species richness, polychaete abundance and species diversity. Species number and average density were found within the intervals of mean values reported in similar studies. The higher number of species and organisms obtained in March-April and June-July can be attributed to the recruitment correlated with the regional up-welling.     

Applications of mesenchymal stem cells labeled with Tat peptide conjugated quantum dots to cell tracking in mouse body

Fluorescent quantum dots have great potential in cellular labeling and tracking. Here, PEG encapsulated CdSe/ZnS quantum dots have been conjugated with Tat peptide, and introduced into living mesenchymal stem cells. The Tat peptide conjugated quantum dots in mesenchymal stem cells were assessed by fluorescent microscopy, laser confocal microscope and. flow cytometry. The result shows that Tat peptide conjugated quantum dots could enter mesenchymal stem cells efficiently. The Tat-quantum dots labeled stem cells were further injected into the tail veins of NOD/SCID beta2 M null mice, and the tissue distribution of these labeled cells in nude mice were examined with fluorescence microscope. The result shows that characteristic fluorescence of quantum dots was observed primarily in the liver, the lung and the spleen, with little or no quantum dots accumulation in the brain, the heart, or the kidney.     

Performance evaluation of a wood-chip based biofilter using solid-phase microextraction and gas chromatography-mass spectroscopy-olfactometry

A pilot-scale mobile biofilter was developed where two types of wood chips (western cedar and 2 in. hardwood) were examined to treat odor emissions from a deep-pit swine finishing facility in central Iowa. The biofilters were operated continuously for 13 weeks at different air flow rates resulting in a variable empty bed residence time (EBRT) from 1.6 to 7.3 s. During this test period, solid-phase microextraction (SPME) PDMS/DVB 65 microm fibers were used to extract volatile organic compounds (VOCs) from both the control plenum and biofilter treatments. Analyses of VOCs were carried out using a multidimentional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O) system. Results indicated that both types of chips achieved significant reductions in p-cresol, phenol, indole and skatole which represent some of the most odorous and odor-defining compounds known for swine facilities. The results also showed that maintaining proper moisture content is critical to the success of wood-chip based biofilters and that this factor is more important than media depth and residence time.     

Development of highly polymorphic tetranucleotide microsatellite markers in Austrocedrus chilensis

An enriched genomic library was constructed and 9 novel polymorphic tetranucleotide microsatellite markers developed for Austrocedrus chilensis, the most economically important native conifer in the Andean Patagonian region. Polymorphism was investigated for these markers in 48 individuals from two populations. Numbers of alleles ranged from 3 to 19 and levels of observed heterozygosity among the 9 loci ranged from 0.32 to 0.95. No locus combinations exhibited linkage disequilibrium. These polymorphic markers will be useful tools for the study of demography and gene flow and more in general for population and conservation genetics of this species.     

Longitudinal Analysis of the Eco‐Design Management Standardization Process in Furniture Companies

This article discusses how eco‐design management standards have been adopted and the environmental and economic results that have been obtained by the Spanish furniture manufacturers. This is precisely the industry sector in Spain where the dissemination of eco‐design standards has been most important. Using multiple case‐study methodology, the research has shown that, in three companies, more than 90% of the environmental impact of the companies’ products occurs within the manufacturing phase. Companies have implemented tools for life cycle assessment with eco‐indicators values that allow them to assess complex products and evaluate their significant environmental impacts at each stage. The environmental strategies of these companies are based on the continuous improvement of the internal processes and the review and monitoring of their activities. In this approach, the proper choice of materials and the environmental management of the supply chain are the main problems for companies. The outcomes achieved by the companies included some improvements, such as a greater control of product management and a reduction in operating costs, that have allowed them to obtain competitive advantages. Moreover, the adoption of standard management has enabled the companies to drive innovation of products, improve the image of companies and their products, significantly reduce the environmental impact of their products, and adapt to new, more demanding environmental laws and regulations.     

Microrheological characteristics of reticulocyte in vivo

Using the method of phenylhydrazine-induced anemia in rabbits, a mass of new reticulocytes, which synchronously grow, were got in vivo. The measurements of deformation index, orientation index, electrophoresis mobility etc. were performed for more than 72 h in the process of reticulocytes turning into red blood cells in vivo. There were obvious changes in the microrheological characteristics of reticulocytes in the course of turning into erythrocytes. The present study is significant in clinic for studying erythrocytes’ microrheological characteristics when there are a lot of reticulocytes in blood, and also important in basic theorem for studying reticulocytes microrheological characteristics. It makes up a deficiency in the study on microrheological characteristics of reticulocytes turning into new RBCs from reticulocytes during reticulocytes life span.     

Multiple virulence factors of Cryptococcus neoformans are dependent on VPH1

Acidification of vesicular compartments plays an important role in a number of cellular transport processes, including protein secretion, metal cofactor insertion, glycosylation and pH stability. In the present study, we identify and characterize a component of the vesicular proton pump, Vph1p, to determine its role in the virulence of the AIDS-related fungal pathogen Cryptococcus neoformans. Insertional mutagenesis and plasmid rescue were used to identify the VPH1 gene by screening for mutants defective in laccase activity. Disruption of VPH1 resulted in defects in three virulence factors (capsule production, laccase and urease expression), as well as a growth defect at 37 degrees C, but only a small growth reduction at 30 degrees C. These effects were duplicated by the vacuolar (H+)-ATPase inhibitor bafilomycin A1. Furthermore, the vph1 insertional mutant was also avirulent in a mouse meningo-encephalitis model. Complementation of the insertional mutant with wild-type VPH1 resulted in a recovery of virulence factor expression, normal growth at 37 degrees C and restoration of full virulence. These studies establish the importance of the VPH1 gene and vesicular acidification in the virulence of C. neoformans.     

Effect of land use conversion on soil organic carbon sequestration in the loess hilly area, loess plateau of China

Changes in land use may alter land cover, which results in carbon stock changes in biomass as well as in the soil. In China’s loess plateau, vegetation restoration has been conducted since 1950s to control soil erosion and improve the ecosystem, with significant investment of money and manpower. Despite these efforts, soil erosion has still been severe. To reduce soil erosion and improve land quality, China initiated another state-funded project, Grain-for-Green, in 1999 in the loess plateau. However, it is not clear how effective this newly initiated project will be. In this study, we evaluated the effect of land-use conversion on soil organic carbon (SOC) and the potential effect of the current project on SOC sequestration in the Anjiapo catchment area of the loess hilly area of the loess plateau in China. This evaluation is based on SOC measurements in cropland versus in other converted land use types. We found that SOC sequestration mainly occurred in the surface soil after land use conversion took place. Land use conversion from cropland to shrubland or wild grassland (i.e. undisturbed land) was better for SOC sequestration than tree plantation in the semi-arid loess hilly area. By using the land use change in the study area as a scenario, the potential contribution of land use change on SOC sequestration due to the Grain-for-Green project was estimated. It was found that this project in the loess plateau of China would be helpful for SOC sequestration if successfully implemented.