167 research outputs found

    Biomedical and therapeutic applications of biosurfactants

    Get PDF
    During the last years, several applications of biosurfactants with medical purposes have been reported. Biosurfactants are considered relevant molecules for applications in combating many diseases and as therapeutic agents due to their antibacterial, antifungal and antiviral activities. Furthermore, their role as anti-adhesive agents against several pathogens illustrate their utility as suitable anti-adhesive coating agents for medical insertional materials leading to a reduction of a large number of hospital infections without the use of synthetic drugs and chemicals. Biomedical and therapeutic perspectives of biosurfactants applications are presented and discussed in this chapter

    Rural waste generation: a geographical survey at local scale

    Get PDF
    "The paper examines the per capita waste generation rates from from rural areas of Neamț County (Romania) using thematic cartography. Geographical approach of this issue is difficult because the lack of a geostatistic database at commune scale. Spatial analysis of waste indicators reveals several disparities between localities. Comparability of data between communes located in various geographical conditions must be carrefully made according to local waste management systems. Several dysfunctionalities are outlined in order to compare these results, on the one hand, between localities and on the one hand, between recent years. Geographical analysis of waste generation rates is imperative for a proper monitoring of this sector. Data from 2009, 2010 and 2012 shows that rural waste management is in a full process of change towards a more organized, stable and efficient system." (author's abstract

    The genetic architecture of the human cerebral cortex

    Get PDF
    INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

    The Physics of the B Factories

    Get PDF

    Effects of land use in Southwest Australia: 1. Observations of cumulus cloudiness and energy fluxes

    Get PDF
    The Southwest Australian region has large homogeneous tracts of differing vegetation types separated by a sharp transition called the vermin or bunny fence which runs for almost 750 km. Seasonal winter agriculture is found to the west of the fence, whereas to the east native perennial vegetation grows. Geostationary Meteorological Satellite-5 imagery are used to construct monthly cumulus cloud frequency of occurrence maps for the region 0800 to 1500 LT in hourly increments for 1999 and 2000. Moderate Resolution Imaging Spectroradiometer (MODIS) imagery are used to retrieve regional values of surface temperature, albedo, Normalized Difference Vegetation Index, fractional soil moisture availability, sensible and latent heat fluxes. High spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery are used to retrieve detailed values along the fence. MODIS imagery also is utilized to retrieve cloud optical thickness, droplet sizes, and liquid water paths. This study shows that higher soil moisture availability is found over agricultural areas during winter (September) and over native vegetation areas during summer (December). Latent heat fluxes are higher over native vegetation than over agricultural areas during summer, while sensible heat fluxes are lower. Cumulus clouds occur with higher frequency and have higher optical thicknesses, cloud liquid water contents, and effective radii over agricultural areas during the winter and over native perennial vegetation during the dry summer. This is due to higher latent heat fluxes and available energy over agriculture during winter and over native vegetation during summer. We conclude that land use differences result in differences in available soil moisture and surface energy fluxes, which in turn lead to the observed preferential enhancement of cumulus cloudiness and cumulus cloud properties
    corecore