37 research outputs found
Testing Uniformity of Stationary Distribution
A random walk on a directed graph gives a Markov chain on the vertices of the
graph. An important question that arises often in the context of Markov chain
is whether the uniform distribution on the vertices of the graph is a
stationary distribution of the Markov chain. Stationary distribution of a
Markov chain is a global property of the graph. In this paper, we prove that
for a regular directed graph whether the uniform distribution on the vertices
of the graph is a stationary distribution, depends on a local property of the
graph, namely if (u,v) is an directed edge then outdegree(u) is equal to
indegree(v).
This result also has an application to the problem of testing whether a given
distribution is uniform or "far" from being uniform. This is a well studied
problem in property testing and statistics. If the distribution is the
stationary distribution of the lazy random walk on a directed graph and the
graph is given as an input, then how many bits of the input graph do one need
to query in order to decide whether the distribution is uniform or "far" from
it? This is a problem of graph property testing and we consider this problem in
the orientation model (introduced by Halevy et al.). We reduce this problem to
test (in the orientation model) whether a directed graph is Eulerian. And using
result of Fischer et al. on query complexity of testing (in the orientation
model) whether a graph is Eulerian, we obtain bounds on the query complexity
for testing whether the stationary distribution is uniform
Effects of DC electric field on particle transportation and deposition in evaporating droplets
Microfluidics(uF) is the science of manipulating and controlling the fluids usually in the range of microliters (10-6L) to picolitres (10-12L). Physical parameters, such as surface tension and contact angle do not play a significant effect on macro scale but play a crucial role at the microscopic level. Microfluidics is viewed as an essential tool for life science research and flexible electronics. A deeper understanding of physical parameters of microfluidics would result in more efficient and lower cost devices (‘Lab-on-a-Chip’ devices) and foldable electronics. In short, the concepts of microfluidics can be used to reduce the cost, size, and ease of usage in a wide variety of futuristic products. In our study we are going to explore the effects of electric fields on a particle transport in evaporating droplet and deposition patterns left behind evaporating droplets. We will be studying droplets evaporating on ‘Electrowetting on Dielectric’ (EWOD) devices where the droplet is separated from the active electrode by dielectric layers. These types of devices are relevant in a variety of applications such as medical diagnostics and optics. We believe that understanding this phenomenon will impact printing and the development of flexible electronics. This work will further the understanding of transport and deposition of particles in evaporating droplets under applied electric field by understanding the effects of particle concentrations and different dielectric layer. Previous works have demonstrated that particle transport in evaporating droplets and their resultant deposition patterns can be altered under the presence of the electric fields. Applied electric fields have potential to provide real-time control of the particle transport in evaporating droplets by allowing an instantaneous control of the contact line dynamics, electrophoretic manipulation of particles inside the droplet, changes in interface shape, dielectrophoretic manipulation and particle motion inside the droplet due to forces induced by the electric field and evaporation. Our work is going to provide a deeper insight into the effects of DC electric fields on droplets with varying particle concentrations on different dielectric layer. We will better understand the effects of changing the variables (i.e., hydrophobicity ,polarity and particle concentration) under applied DC electric field
Brave: A Virtual Reality Game
Virtual Reality has a wide range of applications whether it be in educational, medical or gaming. There is a huge demand for Virtual Reality in gaming industries as due to this immersive technology gamer feels he/she is part of gaming environment rather than a mere observer. VR game is a powerful tool to depict mental illness of the patient as mental illness is often underestimated and misunderstood. This will help to educate masses about it and in a way create awareness and eradicate its stigma. We trying to develop a game on the theme based on social anxiety
Sphincter saving anorectoplasty (SSARP) for the reconstruction of Anorectal malformations
<p>Abstract</p> <p>Background</p> <p>This report describes a new technique of sphincter saving anorectoplasty (SSARP) for the repair of anorectal malformations (ARM).</p> <p>Methods</p> <p>Twenty six males with high ARM were treated with SSARP. Preoperative localization of the center of the muscle complex is facilitated using real time sonography and computed tomography. A soft guide wire is inserted under image control which serves as the route for final pull through of bowel. The operative technique consists of a subcoccygeal approach to dissect the blind rectal pouch. The separation of the rectum from the fistulous communication followed by pull through of the bowel is performed through the same incision. The skin or the levators in the midline posteriorly are not divided. Postoperative anorectal function as assessed by clinical Wingspread scoring was judged as excellent, good, fair and poor. Older patients were examined for sensations of touch, pain, heat and cold in the circumanal skin and the perineum. Electromyography (EMG) was done to assess preoperative and postoperative integrity of external anal sphincter (EAS).</p> <p>Results</p> <p>The patients were separated in 2 groups. The first group, Group I (n = 10), were newborns in whom SSARP was performed as a primary procedure. The second group, Group II (n = 16), were children who underwent an initial colostomy followed by delayed SSARP. There were no operative complications. The follow up ranged from 4 months to 18 months. Group I patients have symmetric anal contraction to stimulation and strong squeeze on digital rectal examination with an average number of bowel movements per day was 3–5. In group II the rate of excellent and good scores was 81% (13/16). All patients have an appropriate size anus and regular bowel actions. There has been no rectal prolapse, or anal stricture. EAS activity and perineal proprioception were preserved postoperatively. Follow up computed tomogram showed central placement the pull through bowel in between the muscle complex.</p> <p>Conclusion</p> <p>The technique of SSARP allows safe and anatomical reconstruction in a significant proportion of patients with ARM's without the need to divide the levator plate and muscle complex. It preserves all the components contributing to superior faecal continence, and avoids the potential complications associated with the open posterior sagittal approach.</p
Urinary tract infection, its causative microorganism and antibiotic susceptibility in Nagaland
Aim: We studied the causative microorganisms and antibiotic susceptibility of urinary tract infections (UTI) for both male and female in Nagaland, North-Eastern India. Materials and Methods: This is a retrospective study done at Christian Institute of Health Sciences and Research, Dimapur, where urinary samples received for culture and sensitivity in the laboratory from January 2012 to June 2013 were included. Organisms were identified by doing standard culture method, and antibiotic sensitivity was done by Kirby-Bauer Disc diffusion method from mid-stream clean catch urine sample. Results: A total of 1789 samples were analyzed in this study, where 502 (28.1%) showed significant growth, 330 (18.4%) showed insignificant growth, and the rest 957 (53.5%) showed no growth. The most commonly isolated bacterium was Escherichia coli both in an outpatient department (31%) and in-patient department (38%) patients followed by Klebsiella pneumonia, Pseudomonas sp., Enterococcus, Staphylococcus aureus, Candida, and Proteus. Analysis of the samples showed that UTI was more common in females (60%) as compared to males (40%). It was also observed that the samples responded effectively to chloramphenicol (29%), gentamicin (28%), imipenem (26%), and amikacin (21%). High degree of resistance was shown for nalidixic acid, ciprofloxacin, norfloxacin, amoxyclav, and ofloxacin. Conclusion: Antibiotics have been in use for a long period and more often the misuse of antimicrobial drugs has today led to a general rise in the emergence of resistant bacteria. This study may aid health professionals in choosing the appropriate treatment for patients in North-Eastern India
Environmentally sustainable zinc oxide nanoparticles for improved hazardous textile dye removal from water bodies
A sustainable, affordable, and cost-effective method was developed to synthesize zinc oxide nanoparticles (SB-ZnO-NPs) using leaf extracts of Strobilanthes barbatus. The synthesized SB-ZnO-NPs displayed an absorbance maximum at 359 nm with a band gap of 3.24 eV. The average diameter of the SB-ZnO-NPs, as determined by FESEM analysis, was 84.23 nm. The particles had nearly spherical morphologies. By using FTIR analysis, it was established that functional groups played a part in the formation of SB-ZnO-NPs. Reactive Yellow 86 (RY-86) and Reactive Yellow 145 (RY-145) textile dyes were degraded by SB-ZnO-NPs under the impact of UV irradiation, and the degradation rates were 87.50 and 91.11%, respectively, in 320 min. When dye solutions treated with SB-ZnO-NPs were tested for phytotoxicity, the results showed a sharp decline in the effectiveness of the inhibition compared to dye effluents. The synthesised SB-ZnO-NPs can, therefore, be employed as a substitute potential catalyst for the breakdown of textile colours both before and after release into water bodies.
HIGHLIGHTS
An environmentally friendly green-synthesized zinc oxide nanoparticle was biosynthesized using Strobilanthes barbatus plant extract.;
Reactive Yellow industrial textile dyes were found to degrade photocatalytically when exposed to UV radiation.;
Phytotoxicity research reveals that degraded dyes are less hazardous to aquatic life.
Angiotensin converting enzyme gene polymorphism in Asian Indian children with congenital uropathies
Purpose:
To evaluate the role of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism as a risk factor for progressive renal damage in Asian Indian children with congenital uropathies.
Materials and Methods:
ACE I/D polymorphism was determined by polymerase chain reaction in 84 children with congenital uropathies and 80 unrelated healthy controls. The study group included primary vesicoureteral reflux (29 patients), pelviureteral junction obstruction (21) and posterior urethral valves (34). Mean patient age was 69.4 ± 4.5 months, and mean followup period was 7.2 ± 1.5 years. Serum creatinine, ultrasound, voiding cystourethrogram and dimercaptosuccinic acid scans were done to evaluate renal function.
Results:
The ACE I/D genotype distribution was similar in the 84 patients, II in 37 (44%), DI in 30 (35.7%) and DD in 17 (20.2%), and 80 controls, II in 36 (45%), DI in 30 (37.5%) and DD in 14 (17.5%), chi-square 0.00, p = 1.0). Renal scarring was seen in 49 of 84 patients (58.3%), with D allele present in 35 of 49 (71.4%), compared to 12 of 84 patients (34.2%) in the nonscarring group (chi-square 4.2, p = 0.02). Progressive scarring and renal failure were seen in 23 (27.3%) and 26 (31%) of patients, respectively, with D allele present in 21 of 23 (91.3%) and 21 of 26 (81%), respectively (chi-square 5.4, p = 0.001). Multivariate analysis showed that D allele is an independent risk factor for renal damage.
Conclusions:
The presence of D allele in I/D polymorphism of angiotensin converting enzyme gene is associated with progressive deterioration of renal function in congenital uropathies. The D allele was also significantly associated with renal scarring independent of known risk factors such as grade of reflux, age at diagnosis, gender and urinary tract infection
Metabolite profile of cerebrospinal fluid in patients with spina bifida: a proton magnetic resonance spectroscopy study
Study Design: The present study was carried out to assess the metabolic differences between cerebrospinal fluid samples of patients with spina bifida and age-matched control individuals. Objectives: To study the metabolite profile of cerebrospinal fluid of patients with spina bifida using proton magnetic resonance spectroscopy, compare the levels of metabolites with controls, establish correlation of underlying neuronal dysfunction with metabolic changes in patients with spina bifida, and evaluate the potential use of this technique as an additional tool for diagnostic assessment. Summary of Background Data: Combination of embryopathy, stretching, ischemia, compression, and trauma is responsible for cord dysfunction in spina bifida. Changes in neuronal metabolism leads to changes in the local milieu of cerebrospinal fluid in the cord. Change in metabolite profile of cerebrospinal fluid in spina bifida in terms of increase in products of anaerobic metabolism, nerve membrane integrity, and nerve ischemia has not yet been studied. Methods: Cerebrospinal fluid obtained from patients and control individuals were characterized using various one- and two-dimensional proton magnetic resonance spectroscopy techniques. Concentration of various metabolites was calculated using the area under the nuclear magnetic resonance peak. Results: Statistically significantly higher levels of lactate, choline, glycerophosphocholine, acetate, and alanine in the cerebrospinal fluid of patients with spina bifida was observed compared with control individuals. Conclusions: Significantly higher levels of metabolites were observed in patients with spina bifida, representing a state of nerve ischemia, anaerobic metabolism, and disruption of neuronal membrane
Giant retroperitoneal fetus-in-fetu: An unusual cause of respiratory distress
Fetus-in-fetu (FIF) is a rare congenital condition in which a vertebrate fetus is incorporated within its host, a newborn or an infant. We report an interesting case of FIF presenting as an abdominal mass with respiratory distress in a 4-month-old girl, and review the existing literature. An ultrasound abdomen showed a right sided cystic mass containing multiple calcifications. Laparotomy revealed a well-encapsulated right retroperitoneal mass above the right kidney with two rudimentary limbs attached to an amniotic bag by an umbilical cord. Excision of the capsule revealed a yellowish fluid and an incompletely developed fetus covered by vernix caseosa. Pathologic examination showed an irregular fetiforme mass, weighing 1200 gm, with two rudimentary limbs, encephalus, stomach, duodenum, bowel, bone, cartilage, bone marrow, upper and lower respiratory tissue, and spleen. Complete excision of the FIF was performed. The postoperative period was uneventful and the patient was discharged on the seventh postoperative day