On the height variation of the E-region cowling conductivity ? effect of charged dust particles

International audienceHeight profiles of the Cowling conductivity in the electrojet region, estimated using the atmospheric parameters given by the existing models like CIRA or MSIS and measured electron density profiles, consistently show the heights of the electrojet current intensity peak to be more than 3 km below those estimated from in-situ measurements using magnetometers on board sounding rockets. Kulkarni and Muralikrishna (2005) attempted to explain this to be due to the effect of neutral dust particles. They reported that neutral dust particles, when they exist in sufficient numbers, can modify the collision parameters, especially in the lower E-region, where dust particles of meteoric origin are known to exist in large numbers, and thereby can modify the Cowling conductivity profile in the electrojet region. This work is extended here to include the effect of charged dust particles. Dust particles can become charged negatively by the attachment of ambient free electrons, and can thus reduce the number density of free electrons especially below the electrojet peak. This can alter the vertical profile of the east-west Hall current driven by the vertical Hall polarization field, thereby causing a net reduction in the electrojet current. Such a decrease in the electrojet current may be observed on the ground magnetograms. This mechanism, as proposed here, can operate only during periods of strong meteor shower activity, when the dust particle density at the assumed deposit height of 103 km can reach extreme values (for example, 5×104 cm?3 of 1-µm diameter dust particles). Such a dense dust layer may even cause a reversal in the normally upward vertical Hall polarization field, within the dust layer, causing a reversal of the electrojet currents below the current peak

Harnessing Wisdom for Managing Watersheds: Honey Bee Perspective on Innovations, Institutions and Policies for Marginal Environments

Participatory approaches for watershed management are now considered essential for sustainable natural resources management and yet there is very little opportunity for intellectual participation by the people. This requires understanding of the local knowledge systems and their institutional context. In this paper, we provide an overview of the conceptual framework which can facilitate such participation. The full report being published separately includes case studies of farmers’ innovations in natural resources management.

Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception

Thickness perception of starch-thickened products during eating has been linked to starch viscosity and salivary amylase activity. Calcium is an essential cofactor for α-amylase and there is anecdotal evidence that adding extra calcium affects amylase activity in processes like mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase activity and (2) to measure the effect of calcium concentration on apparent viscosity and thickness perception when interacting with salivary α-amylase in starch-based samples. α-Amylase activity in saliva samples from 28 people was assessed using a typical starch pasting cycle (up to 95 °C). The activity of the enzyme (as measured by the change in starch apparent viscosity) was maintained by the presence of calcium, probably by protecting the enzyme from heat denaturation. Enhancement of α-amylase activity by calcium at 37 °C was also observed although to a smaller extent. Sensory analysis showed a general trend of decreased thickness perception in the presence of calcium, but the result was only significant for one pair of samples, suggesting a limited impact of calcium enhanced enzyme activity on perceived thickness

Three Cube

The objective of this project is to create a three-song world fusion/experimental EP with folk songs from three different regions around the world.https://remix.berklee.edu/graduate-studies-production-technology/1091/thumbnail.jp

Isolation and characterization of acetylated LM-pectins extracted from okra pods

Pectin was isolated by aqueous extraction at pH 6.0 or 2.0 from okra (Abelmoschus esculentus L.) pods. An isolation protocol was designed to extract pectin and to study the influence of the extraction pH on their composition and physicochemical properties. The extracted pectin was assessed using sugar compositional analysis (neutral sugars, galacturonic acid, acetyl and methyl contents). FT-IR and NMR spectroscopy, size exclusion chromatography (SEC) and dilute solution viscometry were also used to determine the macromolecular characteristics of isolated pectin. The extraction protocols resulted in the isolation of pectin of high purity as evidenced by their high total carbohydrate (70.0–81.8%) and low protein (4.3–6.3%) contents. Samples contained between 46 and 56% galacturonic acid, had broad molecular weight distributions, a low degree of methylation (40.0 and 24.6%) and high degree of acetylation (52.2 and 37.6%). Neutral sugar analysis showed that the pectin extracted at pH 6.0 contained more neutral sugars, particularly, galactose (21.7–25.7 mol%), rhamnose (10.1–13.2 mol%) and arabinose (7.1–7.3 mol%) than that extracted at pH 2.0 indicating variations in fine structure. In addition, molecular parameters of the isolated pectins, such as intrinsic viscosity (2.8–4.4 dL g−1), critical concentration (0.15–0.45 dL g−1) and coil overlap parameter (0.66–1.51), showed that extraction conditions resulted in pectin with different chain morphology. The yield and physico-chemical characteristics of the extracted pectin from okra pods were influenced by the extraction conditions

Time-frequency analysis of geopolitical risk and food commodity market: a wavelet based investigation

Purpose. The most recent conflicts have demonstrated that geopolitical risk has evolved into a significant issue that has an impact on the global food markets. Through the use of bi-wavelet coherence analysis, the study aimed to establish the ways in which geopolitical risk and climate policy uncertainties influences the food commodity market using Geopolitical Risk Index (GPR index), Climate Policy Uncertainty Index (CPU index) and the five components that make up the FAO Food Price Index (FPI). Methodology / approach. The study used monthly data spanning from January 1990 to March 2024. Geopolitical risk was measured using the GPR index developed through textual analysis of news articles. CPU index, developed using similar textual analysis, is used to represent the uncertainties related to climate change risk. The FAO’s FPI constituents were used to represent global food commodity market. The research applied advanced econometric methods including Johansen cointegration tests, Toda-Yamamoto causality analysis, Brock-Dechert-Scheinkman (BDS) nonlinearity tests, and bi-wavelet coherence analysis. Wavelet coherence analysis was particularly focused due to its capability to capture dynamic, time-frequency relationships among non-stationary data series. Results. The study found two significant long-run cointegrating relationships among GPR, CPU and FPI constituents. Causality tests indicated that geopolitical risk significantly influenced climate policy uncertainty but not vice versa. Wavelet analysis revealed that GPR and vegetable oil has more strong co-movement, and it is also the same in the case of CPU. CPU has a leading influence on GPR, which means that policy uncertainties lead to increased geopolitical tensions. Uncertainties in climate policies have an effect on food commodity market in the short run. Whereas, GPR affects cereals during geopolitical tension periods. In the case of dairy products, time varying co-movements in the short run could be witnessed whereas in the long run medium co-movement could be seen. Volatilities occur in the prices of vegetable oils during periods of crisis which can exacerbate prices of other food commodities, which can lead to food security issues. Originality / scientific novelty. The originality of the study lies in the fact that the main focus is on GPR, CPU and five constituents of FAO’s FPI. Moreover, the study uniquely incorporates CPU index as a proxy to climate change risk and its impact on food commodity market. Most of the studies focus on the spillover effect of geopolitical risk on different classes of asset. Significant number of literatures focus on the spillover effect on oil market, stock market and commodities market. However, there are only limited studies that focus on food commodity market. In addition, analysing these factors provides a deeper understanding of how they affect food security and market dynamics. This innovative approach offers valuable insights to policymakers, investors and stakeholders of food commodity market. Practical value / implications. Creating a more economically sustainable environment is the goal of every country, which requires joint efforts by various sectors of the financial market, government officials and economic regulators. These findings are of great importance to policymakers and stakeholders in global food systems, highlighting the need to create adapted policy frameworks, focus on the vulnerability of individual commodities, and carefully implement climate policies to mitigate potential negative impacts on food security

A fast cam driven absorption cell based rocketborne nitric oxide detector

A nitric oxide(NO) detector, making use of a newly developed fast cam-driven absorption cell system is developed for launch on board a Brazilian SONDA III rocket, to measure the height profile of the NO gamma band dayglow emission intensity and thereby to estimate the height profile of the number density of atmospheric NO in the equatorial region. Two absorption cells, one of them containing the gas NO and the other nitrogen are brought in front of the photocathode of a photomultiplier (PM) tube alternately using a cam system. Each cell remains in front of the PM tube for an interval of time fixed by the cam shape. The cam is designed to optimize the time needed for positioning the cells one after the other and also to simplify the operation of the step motor responsible for the movement of the absorption cells. The advantages of this new system over the conventional wheel mounting are also presented.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Crude Birth Rate and Crude Mortality Rate in India: A Case of Application of Regression in Healthcare

India’s demographic transition in 1950 has led to decline of high birth and mortality rate to 6.5%, a drop of 0.6% in 2016–2017, as per the economic survey (2017–2018). The crude birth rate and crude mortality rate decreases with the occupation. In this study, the statistical parameter, confidence interval indicates the true range of the mean of the crude birth rate and crude mortality rate computed from the observed data in the study. Location and precision of a measure are made available with the confidence interval. In the study, the results for crude birth rate in 1984 were highest, 95% CI = 32.08–39.22, and in 2011, were lowest, 95% CI = 20.68–25.24, and the results for crude mortality rate in 1984 were highest, 95% CI = 32.08–39.22, and in 2011 were lowest, 95% CI = 20.68–25.24. A small standard error implies that the sample mean is a more accurate reflection of the actual population mean. The smallest standard error of crude birth rate is 1.08, and the smallest standard error of crude mortality rate is 0.50

Natural Frequency of Vibrating Foundations on Layered Soil System-An Experimental Investigation

This paper presents model block vibration tests results on two and three layered soil system underlain by rigid layer. Using sand and sawdust in different positions (either at top or at middle or at bottom) and thickness (es) inside a tank, different layered soil bed are prepared and vibration tests are conducted on each prepared bed using Lazan Type oscillator. A large number of response curves (frequency vs. amplitude) are obtained on different layered system. Maximum amplitudes (resonant amplitude) and corresponding frequencies (resonant frequency) are tabulated to study the effect of layering on resonant frequencies. Effects of position and thickness (es) of the layer/layers on natural frequencies are found to be significant, Natural frequency increases significantly due to presence of thin stiff layer at top compared to natural frequency of bottom layer treating it to be half space whereas it decreases significantly due presence of thin soft layer at top. Several other significant observations are made and presented in the paper. Natural frequencies of the soil foundation on different layered soil systems used for the experimental investigations are predicted using static equivalent stiffness of the system and compared with experimental results. Predicted results are found to be in good agreement with the experimental results