Network Potentials

A network payoff function assigns a utility to all participants in a (social) network. In this paper we discuss properties of such network payoff functions that guarantee the existence of certain types of pairwise stable networks and the convergence of certain network formation processes. In particular we investigate network payoff functions that admit an exact network potential or an ordinal network potential. We relate these network potentials to exact and ordinal potentials of a non-cooperative network formation game based on consent in link formation. Our main results extend and strengthen the current insights in the literature on game theoretic approaches to social network formation

Prediabetes, dyslipidemia and c-reactive protein levels among stroke patients: a hospital-based study in north-east India

Background: Stroke is defined as an abrupt onset of a neurologic deficit lasting for more than 24 hours that is attributable to a focal vascular cause. Hyperglycemia and dyslipidemia are often documented in stroke patients. Elevated CRP level is independently associated with the excessive risk of ischemic stroke. Aim and Objectives were to evaluate the glycemic status, lipid profile and c-reactive protein level in stroke patients admitted in a teaching institute of north-east India.Methods: A cross-sectional hospital-based study conducted in the department of medicine, Agartala Government Medical College and GBP hospital, within a period of January 2020 to June 2021. Data were analyzed by SPSS software version 15 using appropriate statistical tests.Results: Among 200 patients of stroke, 50% was found to be pre-diabetic, 40% known diabetic and 10% newly diagnosed diabetic. 60% were hypertensives. Among them, 80% had ischaemic stroke and 20% hemorrhagic stroke. 70% of the patients had hypercholesterolemia, 60% had hypertriglyceridemia. 80% had raised serum LDL and 57% decreased serum HDL. Out of 200 patients, 60% was found to have raised serum CRP level. 55% of ischaemic stroke patients and 5% of hemorrhagic stroke patients had raised CRP level.Conclusions: Prediabetes and newly diagnosed diabetes are highly prevalent in patients with stroke or TIA. As the prevalence of prediabetes is growing rapidly, prediabetes might become one of the most important modifiable therapeutic targets in both primary and secondary prevention. Early detection of dyslipidemia and treatment with drugs along with dietary modifications and lifestyle changes can reduce the risk of stroke. Since, it was a cross-sectional study, these results need to be validated by further long-term prospective studies

Application of DNP-enhanced solid-state NMR to studies of amyloid-β peptide interaction with lipid membranes

The cellular membrane disruption induced by the aggregation of Aβ peptide has been proposed as a plausible cause of neuronal cell death during Alzheimer’s disease. The molecular-level details of the Aβ interaction with cellular membranes were previously probed using solid state NMR (ssNMR), however, due to the limited sensitivity of the latter, studies were limited to samples with high Aβ-to-lipid ratio.The dynamic nuclear polarization (DNP) is a technique for increasing the sensitivity of NMR. In this work we demonstrate the feasibility of DNP-enhanced ssNMR studies of Aβ40 peptide interacting with various model liposomes: (1) a mixture of zwitterionic 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG); (2) a mixture of POPC, POPG, cholesterol, sphingomyelin and ganglioside GM1; (3) the synaptic plasma membrane vesicles (SPMVs) extracted from rat brain tissues. In addition, DNP-ssNMR was applied to capturing changes in Aβ40 conformation taking place upon the peptide insertion into POPG liposomes. The signal enhancements under conditions of DNP allow carrying out informative 2D ssNMR experiments with about 0.25 mg of Aβ40 peptides (i.e. reaching Aβ40-to-lipid ratio of 1:200). In the studied liposome models, the 13C NMR chemical shifts at many 13C-labelled sites of Aβ40 are characteristic of β-sheets. In addition, in POPG liposomes the peptide forms hydrophobic contacts F19-L34 and F19-I32. Both the chemical shifts and hydrophobic contacts of Aβ40 in POPG remain the same before and after 8 h of incubation. This suggests that conformation at the 13C-labelled sites of the peptide is similar before and after the insertion process. Overall, our results demonstrate that DNP helps to overcome the sensitivity limitation of ssNMR, and thereby expand the applicability of ssNMR for charactering the Aβ peptide interacting with lipids

Clustering of Marine Oil-Spill Extent Using Sentinel-1 Dual Polarimetric Scattering Spectrum

Oil spills pose a significant threat to the maritime ecosystem. Identifying an oil spill is vital to assess its spread and drift to nearby coastal areas. Synthetic aperture radar (SAR) sensors are viable for mapping and monitoring marine oil spills. This study proposes a new technique that utilizes the dual-polarimetric Sentinel-1 SAR data. The method is based on projecting the 2 × 2 covariance matrix onto distinct random realizations of the normalized scattering configuration. We then obtain the dual-polarimetric spectrum of the scattering-type parameter, θDP. The θDP spectrum is then used in the unsupervised K-means clustering technique to segment oil spills from the rest. The cluster findings are then compared to the accuracies obtained using the standard scattering-type parameters from the eigen-decomposition approach (VV, VH) intensities and Otsu thresholding of [H + α + A] parameter. We demonstrate the proposed approach by clustering marine oil-spill extent over parts of India, Kuwait, the UAE, and the Mediterranean Sea obtained by Sentinel-1 SAR images. We observed that the clustering accuracy of the proposed technique outperforms the ones obtained from the channel (i.e., VV and VH) intensities, Otsu thresholding of [H + α + A] parameter, and the eigen-decomposition-based method. The proposed approach improves the overall accuracy by ≈8% and ≈20%, respectively, over different study areas

A Statistical-Topological Feature Combination for Recognition of Isolated Hand Gestures from Kinect Based Depth Images

International audienceReliable hand gesture recognition is an important problem for automatic sign language recognition for the people with hearing and speech disabilities. In this paper, we create a new benchmark database of multi-oriented, isolated ASL numeric images using recently launched Kinect V2. Further, we design an effective statistical-topological feature combinations for recognition of the hand gestures using the available V1 sensor dataset and also over the new V2 dataset. For V1, our best accuracy is 98.4% which is comparable with the best one reported so far and for V2 we achieve an accuracy of 92.2% which is first of its kind

Trichoderma: A part of possible answer towards crop residue disposal

India is one of the leading countries in agricultural production and generate large volume of crop residue. Increasing demand for food grains due to growing population leads to generation of crop residues. Due to lack of proper disposal mechanism of crop residue, farmers burn the residue which release greenhouse gases (GHGs) into the atmosphere, and poses great threat to environment as well as human health. The residue burning causes greater carbon emission and nutrient losses which otherwise incorporated into the soil system may substantially improve the soil biodiversity. Besides several practices of crop residue management, the most feasible method for farmers is incorporation of residue into the soil with the inoculation of microbes. In soil system the ability of microbial community in degrading organic substances is well known. In the early stages of residue decomposition simple substrates like carbohydrates are degraded by bacteria, but in later stages degradation of complex constituents viz., cellulose, lignin needs microbes which are capable of secreting enzymes like cellulase, acting on complex organic substrates. In this context, cellulolytic micro organisms like Trichoderma have the potential and emerging as an important microbial inoculants to enhance the rate of decomposition as well as alleviate the effect of residue burning