SNR estimation in linear systems with Gaussian matrices

This letter proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the linear system has a Gaussian matrix with one sided left correlation. The unknown entries of the signal and the noise are assumed to be independent and identically distributed with zero mean and can be drawn from any distribution. We use the ridge regression function of this linear model in company with tools and techniques adapted from random matrix theory to achieve, in closed form, accurate estimation of the SNR without prior statistical knowledge on the signal or the noise. Simulation results show that the proposed method is very accurate

An explorative clinical study to evaluate the combined effect of Shiropichu, Sthanika Abhyanga, Salvana Upanaha Sweda and Balarishta in the management of Pakshaghata vis~a~vis Hemiplegia

Pakshaghata is one among the Vata Nanatmaja Vyadhi, characterised by loss of function either in right or left half of the body. Pakshaghata is also considered among the ailments of Madhyama Roga Marga. Signs and symptoms of Pakshaghata is similar to that of stroke with hemiplegia as the cardinal clinical feature. It makes the affected person physically disabled and reduces quality of life. Even though western science had moved for in acute management of stroke, it is very difficult to handle the residual effect of stroke which makes person physically and mentally debilitated. In case of managing residual cases, it depends on physiotherapy and exercises, which gives good results if combined with Ayurvedic treatments such as Abhyanga. Present study is a single group open clinical trial with pre and post-test design with a sample size of 30 subjects. Subjects were administered with Shiropichu, Sthanika Abhyanga, Salvana Upana Sweda for first 10 consecutive days and Shamanaaushadha for all 30 days. The results obtained on parameter muscle power, muscle tone, finger movements and deep tendon reflexes was statistically non-significant in the management of Pakshaghata vis-à-vis hemiplegia. The results obtained on parameter stroke specific quality of life scale showed statistically significant result with p value 0.005 in the management of Pakshaghata vis-à-vis hemiplegia. Hence, it was inferred that the intervention selected for the present study possess combined effect in improving the quality of life of individual affected with Pakshaghata vis-à-vis Hemiplegia

Metagenomics of pigmented and cholesterol gallstones: the putative role of bacteria

There is growing evidence for bacteria playing a role in the pathogenesis and formation of pigmented gallstones from humans. These studies mainly involved cultivation of gallstone-associated bacteria and 16S rRNA profiling, providing an indirect link between processes involved in gallstone formation by the bacteria in-situ. Here, we provide functional metagenomic evidence of a range of genes involved in bile stress response, biofilm formation, and anaerobic energy metabolism by Gram-negative Klebsiella in pigmented gallstones from a 76-year-old male patient. Klebsiella was also present in one cholesterol-type stone in a 30-year-old female patient who had additional cholesterol gallstones characterised by Gram-positive bacteria. Pigmented stones further revealed a predominance of genes involved in carbohydrate metabolism, whilst cholesterol stones indicated a profile dominanted by protein metabolism possibly reflecting known chemical differences between Gram-negative and Gram-positive biofilm matrices. Archaeal genes were not detected. Complementary carbon and hydrogen isotopic analyses of cholesterol within the patients' stones revealed homogeneity, suggesting a common diet or cholesterol biosynthesis pathway that has little influence on microbial composition. This pilot study provides a framework to study microbial processes that play a potential role in gallstone formation across markedly different types of stones and patient backgrounds

Comparison of clinical outcomes of conventional hemodialysis and online hemodiafiltration

Background: Several studies have suggested that online hemodiafiltration (OL-HDF) may reduce the risk of mortality and improve quality of life of these patients compared with standard hemodialysis. Methods: Forty stable out patients on dialysis (20 patients on hemodialysis and 20 patients on online hemodiafiltration) above age of 18 years and dialysis vintage of more than 3 months were followed up for 18 months. Clinical, biochemical parameters of these patients along with the SF-36 score at baseline and after 18 months of follow up were assessed. Results: At 18 months, statistically significant difference was found between hemodialysis (HD) and OL- HDF groups in erythropoietin dose (p=0.047), urea reduction ratio (p=0.016), Kt/V (p=0.005), hemoglobin (p=0.043), serum albumin (p=0.002), phosphorus (p=0.024), parathyroid hormone (p=0.007), potassium (p=0.007), β2 microglobulin (p=0.002), high sensitive c-reactive protein (p=0.037), and serum bicarbonate levels (p=0.022). We found statistically significant difference in intradialytic complications namely intradialytic hypotension, muscle cramps, simultaneous hypotension and muscle cramps and stoppage of dialysis. In terms of mortality, the difference was not statistically significant (p=0.052). Conclusions: Patients on OL- HDF were having better quality of life than patients on HD. Better solute clearance, anemia control, improved nutritional and Mineral bone disorder parameters were seen in OL-HDF. Less complications during dialysis were seen with OL-HDF. The difference in mortality rate between the HD group and OL- HDF group was not statistically significant

Energy Effective Routing Protocol for Maximizing Network Lifetime of WSN

ABSTRACT: Efficiency is the keynote factor going to be addressed in this paper. Considering the fact that there are relatively very few wireless sensor networks and hardly any efficient ones, EMBA (Efficient Multihop Broadcast Asynchronous), a duty-scheduled asynchronous wireless sensor networks is being proposed that carries the ability to wake up according to its own schedule. This is accomplished by the forwarders' guidance and the overhearing of broadcast messages and ACK. A forwarders' guidance is when a node transmits broadcast messages to its neighbour nodes by using unicast transmissions thereby reducing redundant transmissions and arising collisions. The active time of nodes is considerably decreased by the overhearing of broadcast messages and ACKs by keeping a thorough check on the number of transmissions and reducing them. In this paper, we put the EMBA and conventional protocols of ADB and RI-MAC broadcast to test in both sparse and dense networks. And, in the end, results exhibit that EMBA achieve a lower message cost due to higher efficiency and lower energy consumption than the conventional protocols

Regularized Linear Discriminant Analysis Using a Nonlinear Covariance Matrix Estimator

Linear discriminant analysis (LDA) is a widely used technique for data classification. The method offers adequate performance in many classification problems, but it becomes inefficient when the data covariance matrix is ill-conditioned. This often occurs when the feature space's dimensionality is higher than or comparable to the training data size. Regularized LDA (RLDA) methods based on regularized linear estimators of the data covariance matrix have been proposed to cope with such a situation. The performance of RLDA methods is well studied, with optimal regularization schemes already proposed. In this paper, we investigate the capability of a positive semidefinite ridge-type estimator of the inverse covariance matrix that coincides with a nonlinear (NL) covariance matrix estimator. The estimator is derived by reformulating the score function of the optimal classifier utilizing linear estimation methods, which eventually results in the proposed NL-RLDA classifier. We derive asymptotic and consistent estimators of the proposed technique's misclassification rate under the assumptions of a double-asymptotic regime and multivariate Gaussian model for the classes. The consistent estimator, coupled with a one-dimensional grid search, is used to set the value of the regularization parameter required for the proposed NL-RLDA classifier. Performance evaluations based on both synthetic and real data demonstrate the effectiveness of the proposed classifier. The proposed technique outperforms state-of-art methods over multiple datasets. When compared to state-of-the-art methods across various datasets, the proposed technique exhibits superior performance.Comment: \c{opyright} 2024 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work

The broken 'Ring of Fire'; a new radiological sign as predictor of syndesmosis injury?

Background We noticed that subcircumferential periosteal oedema above the ankle joint was frequently present on MRI with syndesmosis injuries but was not previously reported. Fluid height within the interosseous membrane has also not been shown to be associated with syndesmosis injury severity. Purpose Investigate whether a new sign on MRI and measurement of the length of fluid within the interosseous membrane above the ankle may be used to enable early identification of a syndesmosis injury and allow differentiation from lateral ligament injury. Methods Three groups of patients were identified from a database and the MRI scans retrieved – those with an isolated syndesmosis injury (SI group), isolated lateral ligament injury (LLI group) and or no injury (NI group) who had an ankle MRI for another reason. The scans were anonymized and independently assessed by eight clinicians (surgeons and radiologists) who were blinded to the diagnosis. The maximum length of fluid above the ankle within the intraosseous membrane was measured for each patient. The presence or absence of distal anterior, lateral and posterior tibial periosteal oedema was recorded (‘Ring of Fire’). Results Measurement of the length of fluid above the ankle had excellent intra-observer reliability (ICC=0.97 [0.93-0.99]) but poor interobserver reliability. Fluid extended higher in both the LLI group (p=0.0043) and SI group (p=0.0058) than the NI group but there was no significant difference between the LLI and SI groups (p=0.3735) indicating that this measurement cannot differentiate between the injuries. The presence of the ‘Ring of Fire’ around the distal tibia was significantly more frequent in the SI group when compared to both LLI and NI groups (p<0.00001). The sensitivity of this sign is 49% but when present this sign has a 98% specificity for syndesmosis injury

Antimicrobial activity, toxicity and accumulated hard-tissue debris (AHTD) removal efficacy of several chelating agents

Aim: To evaluate the antimicrobial, toxicity and cleaning effectiveness of ethylenediaminetetraacetic acid (EDTA) and maleic acid (MA) alone and combined with cetrimide (CTR). Methodology: Cytotoxic and genotoxic effects were assessed on Chinese hamster cells V79 using the MTT, clonogenic and micronucleus assays, respectively. The bacterial inhibitory and bactericidal concentrations (MIC and MBC, respectively) were determined on a strain of Enterococcus faecalis. Antimicrobial tests were performed on a biofilm model after treatment with the chelating agents by using a biofilm eradication concentration (MBEC) and confocal laser scanning microscope (CLSM) assays. Quantification of cell biomass and percentage of live and dead cells in the biomass were assessed for each group. The percentage reduction of accumulated hard-tissue debris (AHTD) after root canal preparation and final irrigation protocols was evaluated by micro-CT. Statistical tests of one-way analysis of variance (anova), Bonferroni test, Kruskal\u2013Wallis test, Dunn\u2019s multiple comparison test and Wilcoxon matched-pairs signed-rank tests were used. Results: Cetrimide alone as well as in combination with EDTA and MA at dilutions of 1/10 and 1/100 was significantly more toxic as compared to untreated controls (P&nbsp;&lt;&nbsp;0.001). All tested mixtures were nontoxic at a dilution of 1/1000. EDTA retained a weak inhibitory and bactericidal effect against planktonic cells, whilst MA inhibited cells growth and killed 99.9% of the cells when diluted. CTR revealed the most prominent effect, being inhibitory and bactericidal, also when diluted. Cetrimide alone or combined with EDTA was able to remove, respectively, 40% (P&nbsp;&lt;&nbsp;0.01) and 60% (P&nbsp;&lt;&nbsp;0.001) of the entire biomass after 1&nbsp;min. Conversely, MA alone and in combination with CTR did not have a significant effect on biomass reduction. After final irrigation, the AHTD volume was significantly decreased in all groups (P&nbsp;&lt;&nbsp;0.05). EDTA&nbsp;+&nbsp;CTR and MA&nbsp;+&nbsp;CTR were associated with a significant reduction in the percentage of AHTD on the entire root canal compared to the same solutions without surfactant. Conclusions: 7% MA was less cytotoxic in comparison with 17% EDTA. The addition of cetrimide to EDTA and MA removed accumulated hard-tissue debris effectively from the canal walls and increased their antimicrobial activity when compared to the same solutions without detergents

Anti-malarial effect of gum arabic

<p>Abstract</p> <p>Background</p> <p>Gum Arabic (GA), a nonabsorbable nutrient from the exudate of <it>Acacia senegal</it>, exerts a powerful immunomodulatory effect on dendritic cells, antigen-presenting cells involved in the initiation of both innate and adaptive immunity. On the other hand GA degradation delivers short chain fatty acids, which in turn have been shown to foster the expression of foetal haemoglobin in erythrocytes. Increased levels of erythrocyte foetal haemoglobin are known to impede the intraerythrocytic growth of <it>Plasmodium </it>and thus confer some protection against malaria. The present study tested whether gum arabic may influence the clinical course of malaria.</p> <p>Methods</p> <p>Human erythrocytes were <it>in vitro </it>infected with <it>Plasmodium falciparum </it>in the absence and presence of butyrate and mice were <it>in vivo </it>infected with <it>Plasmodium berghei </it>ANKA by injecting parasitized murine erythrocytes (1 × 10⁶) intraperitoneally. Half of the mice received gum arabic (10% in drinking water starting 10 days before the day of infection).</p> <p>Results</p> <p>According to the <it>in vitro </it>experiments butyrate significantly blunted parasitaemia only at concentrations much higher (3 mM) than those encountered <it>in vivo </it>following GA ingestion (<1 μM). According to the <it>in vivo </it>experiments the administration of gum arabic slightly but significantly decreased the parasitaemia and significantly extended the life span of infected mice.</p> <p>Discussion</p> <p>GA moderately influences the parasitaemia and survival of <it>Plasmodium-</it>infected mice. The underlying mechanism remained, however, elusive.</p> <p>Conclusions</p> <p>Gum arabic favourably influences the course of murine malaria.</p