The C:N:P:S stoichiometry of soil organic matter

The formation and turnover of soil organic matter (SOM) includes the biogeochemical processing of the macronutrient elements nitrogen (N), phosphorus (P) and sulphur (S), which alters their stoichiometric relationships to carbon (C) and to each other. We sought patterns among soil organic C, N, P and S in data for c. 2000 globally distributed soil samples, covering all soil horizons. For non-peat soils, strong negative correlations (p < 0.001) were found between N:C, P:C and S:C ratios and % organic carbon (OC), showing that SOM of soils with low OC concentrations (high in mineral matter) is rich in N, P and S. The results can be described approximately with a simple mixing model in which nutrient-poor SOM (NPSOM) has N:C, P:C and S:C ratios of 0.039, 0.0011 and 0.0054, while nutrient-rich SOM (NRSOM) has corresponding ratios of 0.12, 0.016 and 0.016, so that P is especially enriched in NRSOM compared to NPSOM. The trends hold across a range of ecosystems, for topsoils, including O horizons, and subsoils, and across different soil classes. The major exception is that tropical soils tend to have low P:C ratios especially at low N:C. We suggest that NRSOM comprises compounds selected by their strong adsorption to mineral matter. The stoichiometric patterns established here offer a new quantitative framework for SOM classification and characterisation, and provide important constraints to dynamic soil and ecosystem models of carbon turnover and nutrient dynamics

Assessing the impact of body mass index on insulin resistance and metabolic risk factors in pre-diabetic individuals: A comprehensive cross-sectional study

Background: Insulin resistance plays a crucial role in the onset of type 2 diabetes, with body mass index (BMI) being a significant determinant. Aims and Objectives: This study examines the link between BMI and insulin resistance in pre-diabetic individuals to inform strategies for early diabetes intervention. Materials and Methods: This cross-sectional study involved 100 pre-diabetic participants. Data on demographic characteristics, BMI, insulin resistance (measured by the Homeostatic Model Assessment for Insulin Resistance, HOMA-IR), lipid profiles, and blood pressure (BP) were collected. Participants were categorized into normal weight, overweight, and obese groups to explore the relationship between BMI and insulin resistance and its impact on metabolic and cardiovascular health. Results: The average participant age was 45.8 years (SD=12.3), with a slight majority being female (52%) and an average BMI of 28.4 kg/m² (SD=4.5). A significant positive correlation (r=0.64, P<0.001) between BMI and the HOMA-IR index highlighted the association between increased BMI and insulin resistance. Obese individuals had a notably higher HOMA-IR index (3.5±1.3) compared to those overweight (2.5±1.0) and of normal weight (1.9±0.8). In addition, the study found worsening lipid profiles and increased BP with higher BMI categories. Gender did not significantly affect insulin resistance, whereas a slight increase in HOMA-IR with age was noted (r=0.23, P=0.02). Conclusion: The findings highlight the strong correlation between higher BMI and increased insulin resistance in pre-diabetics. They emphasize the importance of managing body weight to mitigate the risk of diabetes and cardiovascular diseases

Silicon Encapsulated Carbon Nanotubes

A dual stage process of depositing bamboo-like carbon nanotubes (BCNTs) by hot filament chemical vapor deposition (HFCVD) and coating Si using Radio frequency sputtering (RFS) technique. The films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron field emission studies (EFE). SEM results suggest a dense network of homogeneous silicon-coated BCNTs. From the comprehensive analysis of the results provided by these techniques emerges the picture of Si encapsulated BCNTs

Influence of Stacking Sequence on the Mechanical and Dynamic Mechanical Properties of Cotton/Glass Fiber Reinforced Polyester Composites

This study focuses on the use of waste cotton fiber from the textile industry to produce composites with unsaturated polyester and to evaluate the performance of glass (G) / cotton (C) fiber laminates, particularly their mechanical and dynamic mechanical properties. Distinct stacking sequences were studied but the overall fiber content was kept constant. In general, hybrid laminates exhibited intermediate mechanical properties compared to those of the pure laminates, and optimum performance was obtained when the glass fiber mats were placed on the surfaces of the composite. Furthermore, some hybrid laminates exhibited superior dynamic mechanical performance, even compared to the pure glass laminate. Lower tan delta peak height (related to better fiber-matrix interaction) values and higher Tg were reported for the [C/G/Ḡ]s and [G/C/C]s samples which, together with the [G/C/Ḡ]s sample, exhibited the best results for reinforcement effectiveness and loss modulus peak height. Therefore, it is found possible to partially replace the glass fiber by waste cotton fiber considering that the final product may be optimized for mechanical property, which requires glass fiber at the surface of the laminate, or for dynamic mechanical properties, that allows higher cotton fiber content

Low field electron emission from nanoclustered carbon grown by cathodic arc

Nanocluster carbon films grown using a cathodic arc process at room temperature in the presence of background gases such as helium are found to be good electron emitters. The variation in the surface morphology and the corresponding emission characteristics of the films with change in helium partial pressure (5×10-4 to 50 Torr) during film growth are reported. The effect of helium partial pressure on clustering was studied for films grown at nitrogen partial pressures of 10-4 and 10-3 Torr. The surface morphology of the films varied from smooth through clusters (with sizes 50-200 nm) to fibrous films. The threshold field varied from 1 to 10 V/μm for an emission current density 1 μA/cm2

Employment generation through livestock and crop enterprises as a means of livelihood

The study was conducted in Andhra Pradesh state to find out employment generation through livestock and crop enterprises as a means of livelihood. Three districts, one from each region and three mandals from each district were selected for the study. 258 livestock farmers who were also holding crop enterprises were selected from nine mandals and eighteen villages for the final investigation. The independent variables such as social status, experience in livestock and crop enterprises, land holding, social participation, herd size, market facilities, material possession, expenditure pattern, knowledge on livestock and crop enterprises, management orientation, achievement motivation, economic orientation, information seeking behaviour, risk taking behaviour,credit orientation, decision making and innovativeness were studied. Study revealed that a vast majority (80.62 per cent) of the farmers belonged to the medium category of employment generation followed by 12.40 per cent high and 6.98 per cent low categories of employment generation. Results showed that an average of 469, 427 and 143 man days of employment generated by dairy, sheep and goat, piggery enterprises respectively and agricultural enterprises created 290 man days ofemployment per family per annum. Individual farmer who depended on livestock enterprises except piggery enterprise was fully employed in three regions. The farmer who depended only on agricultural enterprises was fully employed only in Coastal Andhra region but not in Telangana andRayalaseema regions. It was observed that all independent variables were found to be significant at 1 percent level but experience in livestock & crop enterprises was significant at 5 percent level and social status and social participation found to be non significant