Signaling For Multimedia Conferencing in Stand-Alone Mobile Ad Hoc Networks

Mobile ad hoc networks (MANETs) are infrastructure-less and can be set up anywhere, anytime. They can host a wide range of applications in rescue operations, military, private, and commercial settings. Multimedia conferencing is the basis of a wealth of “killer†applications that can be deployed in MANETs. Some examples are audio/video conferencing, multiplayer games, and online public debating. Signaling is the nerve center of multimedia conferences—it establishes, modifies, and tears down conferences. This paper focuses on signaling for multimedia conferences in MANETs. We review the state of the art and propose a novel architecture based on application-level clusters. Our validation employed SIP as the implementation technology and OPNET as our simulation tool. Our clusters are constructed dynamically and the nodes that act as cluster heads are elected based on their capabilities. The capabilities are published and discovered using a simple application-level protocol. The architectural principles and the clustering operations are discussed. Our SIP-based implementation is also presented along with the performance evaluation. Keywords: MANET, SIP-technology, OPNET-simulation tool, cluste

A Fuzzy Based Link Analysis for Mining Relational Databases

This work introduces a link analysis procedure for discovering relationships in a relational database or a graph, generalizing both simple and multiple correspondence analysis. It is based on a random walk model through the database defining a Markov chain having as many states as elements in the database. Suppose we are interested in analyzing the relationships between some elements (or records) contained in two different tables of the relational database. To this end, in a first step, a reduced, much smaller, Markov chain containing only the elements of interest and preserving the main characteristics of the initial chain, is extracted by stochastic complementation. This reduced chain is then analyzed by projecting jointly the elements of interest in the diffusion map subspace and visualizing the results. This two-step procedure reduces to simple correspondence analysis when only two tables are defined, and to multiple correspondence analysis when the database takes the form of a simple star-schema. On the other hand, a kernel version of the diffusion map distance, generalizing the basic diffusion map distance to directed graphs, is also introduced and the links with spectral clustering are discussed. Several data sets are analyzed by using the proposed methodology, showing the usefulness of the technique for extracting relationships in relational databases or graphs. Keywords:Graph mining, link analysis, kernel on a graph, diffusion map, correspondence analysis, dimensionality reduction, statistical relational learning

MODELING NITROGEN LOADING RATE TO DELAWARE LAKES USING REGRESSION AND NEURAL NETWORKS

The objective of this research was to predict the nitrogen-loading rate to Delaware lakes and streams using regression analysis and neural networks. Both models relate nitrogen-loading rate to cropland, soil type and presence of broiler production. Dummy variables were used to represent soil type and the presence of broiler production at a watershed. Data collected by Ritter & Harris (1984) was used in this research. To build the regression model Statistical Analysis System (SAS) was used. NeuroShell Easy Predictor, neural network software was used to develop the neural network model. Model adequacy was established by statistical techniques. A comparison of the regression and neural network models showed that both perform equally well. Cropland was the only significant variable that had any influence on the nitrogen-loading rate according to both the models.Environmental Economics and Policy,

Fetal absent/hypoplastic nasal bone: a single center follow up study from a tertiary referral hospital in India

Background: This study was undertaken to determine perinatal outcomes in fetuses with absent/hypoplastic nasal bone (AHNB) when considered as a broad entity irrespective of time at which it is identified and identify subgroups with the highest risk of abnormal outcome based on screening status and associated findings.Methods: This was an observational study involving a total of 142 pregnant women whose fetuses were identified with AHNB by ultrasongraphy (USG) during a three year period from January 2016 to December 2018. These women were offered aneuploidy screening/non-invasive prenatal testing (NIPT) or direct invasive testing either alone or in combination. Outcome data was collected and a sub-group analysis was done by dividing them into 8 subgroups based on screening status and associated findings.Results: Out of 12758 scans done during the study period, 142 fetuses (1.11%) were identified with AHNB. 80 (56%) opted the biochemical screening test, 5 (3.5%) opted NIPT while 60 (42.9%) opted for invasive testing. 21 (14.8%) had an abnormal karyotype. In sub-group analysis, the best outcome was seen in group 1, where the biochemical screening was negative and no other aneuploidy markers or anomalies were seen.Conclusions: The present study confirms the association of AHNB with chromosomal disease. However, isolated AHNB with low risk in biochemical screening is rarely associated with aneuploidy. In contrast, a significant no of fetuses yielded abnormal chromosome results when AHNB was associated with high risk in biochemical screening, additional aneuploidy markers or associated anomalies

Case series of trigonal meningiomas

Background Trigonal meningiomas have unique clinical presentation, unlike those in other areas of brain. Situated deep in the brain, the surgical nuances of this tumour are distinctive. We present our experience with this tumour including a discussion of surgical corridors that may be employed. Methods At our centre, 12 trigonal meningiomas were operated over past two decades. A retrospective analysis of case records of these cases was undertaken as regards age, sex clinical presentation, imaging and surgical approach. Results Mean time from heralding symptom to presentation was 10.4 months. At presentation, the most commonly encountered symptoms were those of non-localising symptoms attributable to raised ICP. Majority of lesions were more than 6 cm and on left side and the preferred surgical approach was inferior temporo-parietal. Most symptoms were relieved on long-term follow-up except homonymous hemianopia. Conclusion The incidence of deficit is low on employing the “shortest route” approach, even in the dominant hemisphere and through eloquent area. This may be secondary to possible shift of eloquent area function due to longstanding lesion and may thus be a “workable” surgical option, especially in resource-limited centres where such resources as neuronavigation and tractography may be unavailable

Comparison of normal and weather corrected performance ratio of photovoltaic solar plants in hot and cold climates

Performance Ratio (PR) is one of the best performance metrics used to assess solar power plant performance. PR is also used for commercial acceptance of an installed PV power plants. If the PR is tested in different climatic conditions or seasons, there are bias errors, affecting the contractual acceptance testing. PR is often corrected to the Standard Test Conditions (STC), resulting in higher PR since modules usually operate at higher temperatures. This research work utilizes NREL's advanced methodology to determine weather corrected PR of PV power plants in six different geographical locations and climatic regions. The Solar PV plant performance is simulated to get the normal PR as per IEC 61724-1:2017. Percentage variation of Weather corrected PR with Normal PR is determined for all these six geographical regions and compared. The weather corrected PR of Montana (with the lowest annual average temperature of 1.58 °C.) PV power plant has a maximum variation of 7.64% from the normal PR during the summer and −8.61% variation in December during the winter. The weather corrected PR of Kuzhalmannam (with the highest annual average temperature of 27.28 °C) PV power plant has a maximum variation of only 1.16% from the normal PR during summer and a variation of −0.91% in July during the rainy season. It is concluded that the metric of weather-corrected PR gains paramount importance for colder areas, whereas it has minimal influence for tropical regions

Peptide-based direct electrochemical detection of receptor binding domains of SARS-CoV-2 spike protein in pristine samples

RNA isolation and amplification-free user-friendly detection of SARS-CoV-2 is the need of hour especially at resource limited settings. Herein, we devised the peptides of human angiotensin converting enzyme-2 (hACE-2) as bioreceptor at electrode interface for selective targeting of receptor binding domains (RBD) of SARS-CoV-2 spike protein (SP). Disposable carbon-screen printed electrode modified with methylene blue (MB) electroadsorbed graphene oxide (GO) has been constructed as cost-efficient and scalable platform for hACE-2 peptide-based SARS-CoV-2 detection. In silico molecular docking of customized 25 mer peptides with RBD of SARS-CoV-2 SP were validated by AutoDock CrankPep. N-terminal region of ACE-2 showed higher binding affinity of − 20.6 kcal/mol with 15 H-bond, 9 of which were < 3 Å. Electrochemical biosensing of different concentrations of SPs were determined by cyclic voltammetry (CV) and chronoamperometry (CA), enabling a limit of detection (LOD) of 0.58 pg/mL and 0.71 pg/mL, respectively. MB-GO devised hACE-2 peptide platform exert an enhanced current sensitivity of 0.0105 mA/pg mL(−1) cm(−2) (R(2) = 0.9792) (CV) and 0.45 nA/pg mL(−1) (R(2) = 0.9570) (CA) against SP in the range of 1 pg/mL to 1 µg/mL. For clinical feasibility, nasopharyngeal and oropharyngeal swab specimens in viral transport medium were directly tested with the prepared peptide biosensor and validated with RT-PCR, promising for point-of-need analysis

TREM2 Lipid Sensing Sustains the Microglial Response in an Alzheimer’s Disease Model

SummaryTriggering receptor expressed on myeloid cells 2 (TREM2) is a microglial surface receptor that triggers intracellular protein tyrosine phosphorylation. Recent genome-wide association studies have shown that a rare R47H mutation of TREM2 correlates with a substantial increase in the risk of developing Alzheimer’s disease (AD). To address the basis for this genetic association, we studied TREM2 deficiency in the 5XFAD mouse model of AD. We found that TREM2 deficiency and haploinsufficiency augment β-amyloid (Aβ) accumulation due to a dysfunctional response of microglia, which fail to cluster around Aβ plaques and become apoptotic. We further demonstrate that TREM2 senses a broad array of anionic and zwitterionic lipids known to associate with fibrillar Aβ in lipid membranes and to be exposed on the surface of damaged neurons. Remarkably, the R47H mutation impairs TREM2 detection of lipid ligands. Thus, TREM2 detects damage-associated lipid patterns associated with neurodegeneration, sustaining the microglial response to Aβ accumulation

Dosimetric evaluation of Gammamed High Dose Rate intraluminal brachytherapy applicators

BackgroundA survey of the literature on intraluminal brachytherapy reveals that even for a given tumour site, the dose prescribed varies considerably from one centre to another for multiple reasons: the treatment intent, the association with external beam therapy or not, the dose rate, the technique used and the point of dose specification. There is no common language in the literature as to how doses should be recorded and reported.AimThe purpose of this study was to dosimetrically evaluate various intraluminal brachytherapy applicators for the Gammamed high dose rate afterloading system.Materials/MethodsDosimetric evaluation was carried out for 8mm, 10mm, 12mm and 14mm diameter intraluminal applicators available with the Gammamed high dose rate after-loading system. Treatment planning for these applicators was carried out with the Abacus treatment planning system for active source length and 8cm, 10cm and 12cm. All evaluations were carried out for a prescription dose of 5Gy at the reference point of 1cm from the source axis. Reference volume length (RVL), treated volume (TV) and hyperdose sleeve radius (HSR) were noted down from the isodose plans. Iterative, geometric and equal times optimization routines were carried out for all evaluations with step size of 0.5cm.ResultsThe isodose curves showed tapering pattern towards the distal and proximal regions. The reference volume lengths were larger than active source lengths for 8mm and 10mm diameter applicators. Reference volume lengths were smaller than active source lengths for 12mm and 14mm diameter applicators hyperdose sleeve radius decreases with increase in diameter of the applicator. For 14mm diameter applicators, the hyperdose sleeve radius was smaller than the radius of the reference isodose. Iterative optimization routine gave a better average in terms of reference volume length for all four diameter applicators.ConclusionsWe evaluated the dosimetric parameters for various intraluminal applicators available with the Gammamed high dose rate remote afterloading system. The values of RVL and HSR were within acceptable limits for the four applicators considered in this study

Lysine acetyltransferase Tip60 is required for hematopoietic stem cell maintenance.

Hematopoietic stem cells (HSCs) have the potential to replenish the blood system for the lifetime of the organism. Their 2 defining properties, self-renewal and differentiation, are tightly regulated by the epigenetic machineries. Using conditional gene-knockout models, we demonstrated a critical requirement of lysine acetyltransferase 5 (Kat5, also known as Tip60) for murine HSC maintenance in both the embryonic and adult stages, which depends on its acetyltransferase activity. Genome-wide chromatin and transcriptome profiling in murine hematopoietic stem and progenitor cells revealed that Tip60 colocalizes with c-Myc and that Tip60 deletion suppress the expression of Myc target genes, which are associated with critical biological processes for HSC maintenance, cell cycling, and DNA repair. Notably, acetylated H2A.Z (acH2A.Z) was enriched at the Tip60-bound active chromatin, and Tip60 deletion induced a robust reduction in the acH2A.Z/H2A.Z ratio. These results uncover a critical epigenetic regulatory layer for HSC maintenance, at least in part through Tip60-dependent H2A.Z acetylation to activate Myc target genes.Cancer Research UK, Wellcome Trust, National Institutes of Health, Singapore state fundin