85 research outputs found

    Special 3D electric resistivity tomography (ERT) array applied to detect buried fractures on urban areas: San Antonio TecĂłmitl, Milpa Alta, MĂ©xico

    Get PDF
    AbstractGeophysical techniques can be employed to understand the physical characteristics of the subsurface in highly populated areas, where urban settlements present structural problems. An interesting example is presented in this investigation, where three-dimensional Electric Resistivity Tomography (ERT-3D) is applied employing alternative arrays that allow investigating the subsoil beneath the affected constructions.A small neighborhood comprised by a block of houses within the town of San Antonio Tecómitl is studied. The area is found towards the outskirts of the Chichinautzin range, in the southern limit of the Mexican Basin. This settlement suffers of strong damage in their structures due to fractures and subsidence within the subsoil. ERT-3D was carried out to characterize the subsoil beneath this urban complex. A special resistivity array (‘horse-shoe’ geometry) employing a combination of ‘L’, equatorial-dipole and minimum-coupling methods was carried out to fully ‘illuminate’ the subsoil beneath the block of houses. Computed resistivity models depicted a high resistivity pattern that coincides with the affected houses. Such pattern seems to extend beyond the limits of the surveyed areas, and is probably part of a more complex fracture system. It is very likely that fractures have been produced due to the poorly consolidated soil, which is part of a transition zone; the intense water extraction, that form ‘voids’ in the subsoil causing subsidence effects and finally the existence of regional faults to greater extent that might control these shallow features

    Bacillus amyloliquefaciens as a halo-PGPB and chitosan effects in nutritional value and yield production of Asparagus officinalis L. under Sonora desert conditions

    Get PDF
    Asparagus officinalis L. is a crop associated with arid and dry environments of arid deserts; its tender product is considered a gourmet food for its exclusive consumption and its high prices. Among the main attributes of this vegetable are being a product low in calories, fat and cholesterol, with a high content of vitamin C, as well as rich in potassium and calcium phosphate. The indiscriminate use of synthetic fertilizers in agricultural crop production systems, as well as the increasing dependence, they cause deterioration of the physical and chemical properties of the soil, in addition have a variable impact on the composition and functions of the soil microbiota. Under indigenous area “Seris” in Sonora desert conditions (salinity and high °C), var. ‘Early California’ of asparagus was biofertilized with Bacillus amyloliquefaciens (Ba) as a halo-PGPB and chitosan (QUI) to evaluate nutritional value and yield-production. Results showed that Ba and QUI in the vegetative period increased the emergence rate (≄15%), nitrates in sap (≄10%), fresh and root weight and crown (≄25%); significant values in its subsequent production stage of shoots for human consumption (proximal values such as protein (≄33%), and carbohydrates (≄20%), in addition to K+ (≄9%) and Vit C (≄15%) compared with the control, were obtained. These results express the possibility of using Bacillus amyloliquefaciens as a halo-PGPB and chitosan as a biofertilizer of marine origin in asparagus under Sonora desert conditions

    Method for Bacteriophage Delivery and Amplification

    Get PDF
    Methods of selecting wide host range bacteriophage capable of growing in a plurality of bacteria including pathogenic and non-pathogenic bacteria and bacteriophage selected are described. In addition to methods of treating a subject infected with a pathogenic bacterium using bacteriophage, of decontaminating objects using bacteriophage, of producing vaccines. In another aspect, methods of determining bacterial viability and methods of improving the sensitivity of a biosensor using wide host range bacteriophages are also disclosed

    Method for bacteriophage delivery and amplification

    Get PDF
    Methods of selecting wide host range bacteriophage capable of growing in a plurality of bacteria including pathogenic and non-pathogenic bacteria and bacteriophage selected by the methods are disclosed. Also disclosed are: methods of treating a subject infected with a pathogenic bacterium using bacteriophage, of decontaminating objects using bacteriophage, and of producing vaccines. In another aspect, methods of determining bacterial viability and of improving the sensitivity of a biosensor using wide host range bacteriophages are also disclosed

    On the Relationship between Sialomucin and Sulfomucin Expression and Hydrogenotrophic Microbes in the Human Colonic Mucosa

    Get PDF
    The colonic mucus layer is comprised primarily of acidomucins, which provide viscous properties and can be broadly classified into sialomucins or sulfomucins based on the presence of terminating sialic acid or sulfate groups. Differences in acidomucin chemotypes have been observed in diseases such as colorectal cancer and inflammatory bowel disease, and variation in sialo- and sulfomucin content may influence microbial colonization. For example, sulfate derived from sulfomucin degradation may promote the colonization of sulfate-reducing bacteria (SRB), which through sulfate respiration generate the genotoxic gas hydrogen sulfide. Here, paired biopsies from right colon, left colon, and rectum of 20 subjects undergoing routine screening colonoscopies were collected to enable parallel histochemical and microbiological studies. Goblet cell sialo- and sulfomucins in each biopsy were distinguished histochemically and quantified. Quantitative PCR and multivariate analyses were used to examine the abundance of hydrogenotrophic microbial groups and SRB genera relative to acidomucin profiles. Regional variation was observed in sialomucins and sulfomucins with the greatest abundance of each found in the rectum. Mucin composition did not appear to influence the abundance of SRB or other hydrogenotrophic microbiota but correlated with the composition of different SRB genera. A higher sulfomucin proportion correlated with higher quantities of Desulfobacter, Desulfobulbus and Desulfotomaculum, relative to the predominant Desulfovibrio genus. Thus, acidomucin composition may influence bacterial sulfate respiration in the human colon, which may in turn impact mucosal homeostasis. These results stress the need to consider mucus characteristics in the context of studies of the microbiome that target intestinal diseases

    Perception of the risk of adverse reactions to analgesics: Differences between medical students and residents

    Get PDF
    Low permeability of many wood species due to their anatomical properties causes problems during timber drying as well as impregnating with preservatives and resins. Microwave (MW) treatment influences heartwood permeability and improves preservative uptake and distribution. In the present study, microwave treatment of chir pine (Pinus roxburghii) wood was done at 2,45 GHz frequency at different level of intensity and radiation time. The gas permeability of chir pine wood was measured in an in-house built apparatus. Preservative uptake was tested using acid copper chromate (ACC) preservative by a dipping process. The effect of radiation intensity and time on preservative uptake and air permeability were studied. The results revealed remarkable increase in longitudinal woodair permeability and preservative uptake with the increase of intensity and time of treatment. The results indicate that this technology can be tested and applied on pilot scale for application in wood preservation industry

    Author Correction:A consensus protocol for functional connectivity analysis in the rat brain

    Get PDF

    Author Correction: Native diversity buffers against severity of non-native tree invasions.

    Get PDF

    Native diversity buffers against severity of non-native tree invasions

    Get PDF
    Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2^{1,2}. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4^{3,4}. Here, leveraging global tree databases5,6,7^{5,6,7}, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions

    The global biogeography of tree leaf form and habit

    Get PDF
    Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling
    • 

    corecore