Sub-optimal Ultra-wide Band Receivers

Ultra-wide Band (UWB) has sparked a lot of interest lately from the industry and academia. The growing capacity of the wireless industry is requires a new communication system that satisfies the high data rate which does not interfere with existing RF systems. UWB promises to be this new technology. UWB also promises low power, low cost and flexibility. The UWB Channel opens up a huge new wireless channel with Giga Hertz Capacities as well as the highest spatial capacities measured in bits per hertz per square meter. When properly implemented UWB channel can share spectrum with traditional radio systems without causing harmful interference. In this thesis we studied and compared several reduced complexity sub-optimal Ultra-Wide Band receivers. These receivers include auto correlation receiver, the square value detector and the absolute value detector are studied. We consider OOK and PPM modulation schemes. We examine these schemes and the receivers on Gaussian and UWB indoor channels. We compare the performance with optimal receivers. A transmitter receiver system using 0.1us pulses implemented using existing hardware. A packet consisting of 24 bits were transmitted and the received signal could be verified in real time using a vector signal analyzer. The results show sub-optimal receivers provide a better trade off between robust, complexity and performance

Advanced Supporting Materials for Polymer Electrolyte Membrane Fuel Cells

Among the various kinds of fuel cell, polymer electrolyte membrane fuel cell (PEMFC) is the most prominent energy conversion device for portable applications. The catalyst-supporting materials provide active triple phase boundary for electrochemical reactions where the reactant molecules can easily interact with the catalyst surface. Catalysts play a vital role for improving the overall efficiency of the fuel cells through the advancement in the catalyst and their supporting materials for cathodic oxygen reduction reaction (ORR) in PEMFCs. The supporting materials mainly contribute to increase the electrocatalytic activity of the catalysts by providing more active surface area and extended life-time. The major roles of supporting materials are (i) they act as electron source with improved conductivity; (ii) they hold the metal nanoparticles; (iii) they possess higher surface area and (iv) they should have better stability under operating conditions. In this chapter, the various supporting materials were reviewed carefully based on their nature and performance toward the electrochemical reduction of oxygen for PEMFCs. They are classified into three major categories as (i) carbon supports; (ii) carbon-free supports, and (iii) polymer nanocomposites. In summary, the overall view on support materials and their role on electrocatalysis for fuel cell reactions is provided

Factors in determining seizure control in pediatric patients on antiepileptic medication: a review of the literature

Introduction Pediatric epilepsy is one of the common illness in children. Pediatric epilepsy has significant impact not only to the patient, but also to the care takers. Furthermore, the disease could potentially cause strain in the limited resources of the healthcare system which is preventable. Methods A search was conducted to review relevant published studies on factors affecting seizure control using PubMed/MEDLINE, Google Scholar and also Science Direct searching engines databases using keywords: paediatric seizure, seizure control, side effects, antiepileptic, adherence and quality of life. Results In this review, we found that many factors contribute to the pediatric epilepsy, namely; compliance, genetic, age, socioeconomic factors, parental health literacy and numbers and side effects of the medications. Furthermore, there is certain factors that need to be explored in the future, such as unaddressed parental concern on treatment/medication, denial of disease and drug-drug interactions. Conclusions Factors that had been identified can be used in the prevention and control programs, while factors which is less studied should be further studied in the future

Spindle-shaped CeO2/biochar carbon with oxygen-vacancy as an effective and highly durable electrocatalyst for oxygen reduction reaction

Highly durable and active CeO2 on biochar carbon (CeO2/BC) derived from Spirulina platensis microalgae and synthesized by simple one-pot hydrothermal treatment and further activated through pyrolysis approach. A spindle-shaped morphology of CeO2 with predominant (111) facet was evidently observed from X-ray diffraction patterns and electron microscopy images. The structural features such as high specific surface area, defect-rich carbon with N & P atoms, increased oxygen vacancy and π-electron transfer play an important role for the improved oxygen reduction reaction (ORR). The considerable amount of Ce3+ and higher proportion of pyridinic N and graphitic N species are substantially contributed to the superior ORR performance of CeO2/BC700, which surpasses other similar catalysts and competing with Pt/C. Hence, the significant kinetic ORR parameters and extended stability (no loss after 5000 potential cycles) of the CeO2/BC700 catalysts provides the promising insight to develop the rare-earth metal oxide nanostructures as a possible candidate for ORR in alkaline medium

Annexin A1 Deficiency does not Affect Myofiber Repair but Delays Regeneration of Injured Muscles.

Repair and regeneration of the injured skeletal myofiber involves fusion of intracellular vesicles with sarcolemma and fusion of the muscle progenitor cells respectively. In vitro experiments have identified involvement of Annexin A1 (Anx A1) in both these fusion processes. To determine if Anx A1 contributes to these processes during muscle repair in vivo, we have assessed muscle growth and repair in Anx A1-deficient mouse (AnxA1-/-). We found that the lack of Anx A1 does not affect the muscle size and repair of myofibers following focal sarcolemmal injury and lengthening contraction injury. However, the lack of Anx A1 delayed muscle regeneration after notexin-induced injury. This delay in muscle regeneration was not caused by a slowdown in proliferation and differentiation of satellite cells. Instead, lack of Anx A1 lowered the proportion of differentiating myoblasts that managed to fuse with the injured myofibers by days 5 and 7 after notexin injury as compared to the wild type (w.t.) mice. Despite this early slowdown in fusion of Anx A1-/- myoblasts, regeneration caught up at later times post injury. These results establish in vivo role of Anx A1 in cell fusion required for myofiber regeneration and not in intracellular vesicle fusion needed for repair of myofiber sarcolemma

Superresolution imaging of human cytomegalovirus vMIA localization in sub-mitochondrial compartments

The human cytomegalovirus (HCMV) viral mitochondria-localized inhibitor of apoptosis (vMIA) protein, traffics to mitochondria-associated membranes (MAM), where the endoplasmic reticulum (ER) contacts the outer mitochondrial membrane (OMM). vMIA association with the MAM has not been visualized by imaging. Here, we have visualized this by using a combination of confocal and superresolution imaging. Deconvolution of confocal microscopy images shows vMIA localizes away from mitochondrial matrix at the Mitochondria-ER interface. By gated stimulated emission depletion (GSTED) imaging, we show that along this interface vMIA is distributed in clusters. Through multicolor, multifocal structured illumination microscopy (MSIM), we find vMIA clusters localize away from MitoTracker Red, indicating its OMM localization. GSTED and MSIM imaging show vMIA exists in clusters of ~100–150 nm, which is consistent with the cluster size determined by Photoactivated Localization Microscopy (PALM). With these diverse superresolution approaches, we have imaged the clustered distribution of vMIA at the OMM adjacent to the ER. Our findings directly compare the relative advantages of each of these superresolution imaging modalities for imaging components of the MAM and sub-mitochondrial compartments. These studies establish the ability of superresolution imaging to provide valuable insight into viral protein location, particularly in the sub-mitochondrial compartments, and into their clustered organization

Embelin, a Potent Molecule for Alzheimer's Disease: A Proof of Concept From Blood-Brain Barrier Permeability, Acetylcholinesterase Inhibition and Molecular Docking Studies

Embelin is well-known in ethnomedicine and reported to have central nervous system activities. However, there is no report on blood-brain barrier (BBB) permeability of embelin. Here the BBB permeability of embelin was evaluated using in vitro primary porcine brain endothelial cell (PBEC) model of the BBB. Embelin was also evaluated for acetylcholinesterase (AChE) inhibitory activity and docking prediction for interaction with AChE and amyloid beta (Aβ) binding sites. Embelin was found to be non-toxic to the PBECs and did not disturb the PBEC barrier function. The PBECs showed restrictive tight junctions with average transendothelial electrical resistance of 365.37 ± 113.00 Ω.cm2, for monolayers used for permeability assays. Permeability assays were conducted from apical-to-basolateral direction (blood-to-brain side). Embelin showed apparent permeability (Papp) value of 35.46 ± 20.33 × 10−6 cm/s with 85.53% recovery. In vitro AChE inhibitory assay demonstrated that embelin could inhibit the enzyme. Molecular docking study showed that embelin binds well to active site of AChE with CDOCKER interaction energy of −65.75 kcal/mol which correlates with the in vitro results. Docking of embelin with Aβ peptides also revealed the promising binding with low CDOCKER interaction energy. Thus, findings from this study indicate that embelin could be a suitable molecule to be further developed as therapeutic molecule to treat neurological disorders particularly Alzheimer's disease

Landslide Susceptibility Assessment of a Part of the Western Ghats (India) Employing the AHP and F-AHP Models and Comparison with Existing Susceptibility Maps

Landslides are prevalent in the Western Ghats, and the incidences that happened in 2021 in the Koottickal area of the Kottayam district (Western Ghats) resulted in the loss of 10 lives. The objectives of this study are to assess the landslide susceptibility of the high-range local self-governments (LSGs) in the Kottayam district using the analytical hierarchy process (AHP) and fuzzy-AHP (F-AHP) models and to compare the performance of existing landslide susceptible maps. This area never witnessed any massive landslides of this dimension, which warrants the necessity of relooking into the existing landslide-susceptible models. For AHP and F-AHP modeling, ten conditioning factors were selected: slope, soil texture, land use/land cover (LULC), geomorphology, road buffer, lithology, and satellite image-derived indices such as the normalized difference road landslide index (NDRLI), the normalized difference water index (NDWI), the normalized burn ratio (NBR), and the soil-adjusted vegetation index (SAVI). The landslide-susceptible zones were categorized into three: low, moderate, and high. The validation of the maps created using the receiver operating characteristic (ROC) technique ascertained the performances of the AHP, F-AHP, and TISSA maps as excellent, with an area under the ROC curve (AUC) value above 0.80, and the NCESS map as acceptable, with an AUC value above 0.70. Though the difference is negligible, the map prepared using the TISSA model has better performance (AUC = 0.889) than the F-AHP (AUC = 0.872), AHP (AUC = 0.867), and NCESS (AUC = 0.789) models. The validation of maps employing other matrices such as accuracy, mean absolute error (MAE), and root mean square error (RMSE) also confirmed that the TISSA model (0.869, 0.226, and 0.122, respectively) has better performance, followed by the F-AHP (0.856, 0.243, and 0.147, respectively), AHP (0.855, 0.249, and 0.159, respectively), and NCESS (0.770, 0.309, and 0.177, respectively) models. The most landslide-inducing factors in this area that were identified through this study are slope, soil texture, LULC, geomorphology, and NDRLI. Koottickal, Poonjar-Thekkekara, Moonnilavu, Thalanad, and Koruthodu are the LSGs that are highly susceptible to landslides. The identification of landslide-susceptible areas using diversified techniques will aid decision-makers in identifying critical infrastructure at risk and alternate routes for emergency evacuation of people to safer terrain during an exigency

Improved bi-functional oxygen electrocatalytic performance of PteIr alloy nanoparticles embedded on MWCNT with Pt-enriched surfaces

Multi-walled carbon nanotube supported PteIr nanoparticles (PteIr/MWCNT) with different elemental ratios were synthesized by one-pot co-reduction approach under ambient conditions. The PteIr catalysts exhibit improved bi-functional activity towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) and its electrocatalytic performance was clearly established using different physiochemical characterization techniques. The PteIr composition of 2:1 has a higher electrochemical surface area (ECSA) of about 85.3 m2 /g compared to other compositions (3:1 and 1:1) and Pt/MWCNT due to the effect of particle size distribution. The improved ORR/OER activity was found to be 139.4 and 740 mA/mg, respectively, for PteIr(2:1)/MWCNT with the potential difference of 760 mV for oxygen bi-functional activity. Furthermore, PteIr(2:1)/MWCNT showed much better stability for ORR compared to other compositions and Pt/MWNCT catalysts, i.e., around 76% of its initial ECSA retained with <20 mV shift in half-wave potential was obtained even after 10,000 potential cycles in acidic medium. It is believed that the Pt enriched surface, amount of Ir content, induced electronic and geometric effects play a vital role on the electrocatalytic activity enhancement of PteIr(2:1)/MWNCT as effective bi-functional oxygen electrode