108 research outputs found
Erasure-Resilient Property Testing
Property testers form an important class of sublinear algorithms. In the standard property testing model, an algorithm accesses the input function f:D -> R via an oracle. With very few exceptions, all property testers studied in this model rely on the oracle to provide function values at all queried domain points. However, in many realistic situations, the oracle may be unable to reveal the function values at some domain points due to privacy concerns, or when some of the values get erased by mistake or by an adversary. The testers do not learn anything useful about the property by querying those erased points. Moreover, the knowledge of a tester may enable an adversary to erase some of the values so as to increase the query complexity of the tester arbitrarily or, in some cases, make the tester entirely useless.
In this work, we initiate a study of property testers that are resilient to the presence of adversarially erased function values. An alpha-erasure-resilient epsilon-tester is given parameters alpha, epsilon in (0,1), along with oracle access to a function f such that at most an alpha fraction of function values have been erased. The tester does not know whether a value is erased until it queries the corresponding domain point. The tester has to accept with high probability if there is a way to assign values to the erased points such that the resulting function satisfies the desired property P. It has to reject with high probability if, for every assignment of values to the erased points, the resulting function has to be changed in at least an epsilon-fraction of the non-erased domain points to satisfy P.
We design erasure-resilient property testers for a large class of properties. For some properties, it is possible to obtain erasure-resilient testers by simply using standard testers as a black box. However, there are more challenging properties for which all known testers rely on querying a specific point. If this point is erased, all these testers break. We give efficient erasure-resilient testers for several important classes of such properties of functions including monotonicity, the Lipschitz property, and convexity. Finally, we show a separation between the standard testing and erasure-resilient testing. Specifically, we describe a property that can be epsilon-tested with O(1/epsilon) queries in the standard model, whereas testing it in the erasure-resilient model requires number of queries polynomial in the input size
Role of testicular elastography in the evaluation of male infertility: a comparative cross-sectional study
Background: An estimated 70 million people worldwide are thought to be affected by some severity of infertility. Ultrasound, MRI, and invasive procedures like venography and vasography are the usual investigations taken for the evaluation of infertility. Ultrasound is the preferred initial modality due to its availability and non-invasive nature. In our study, we evaluated the usefulness of advanced ultrasound techniques like Doppler and Elastography and compared the results with biochemical parameters of semen analysis.
Methods: A comparative cross-sectional study was conducted over a period of one year, on men between the ages of 22 and 45, with normal or abnormal sperm analysis reports, who presented with inability to conceive. The testicular parenchyma resistive index, shear value and shear ratio were recorded. The mean values of the data and their standard deviations were assessed and compared by Student’s t-test. The correlation of semen parameters with RI and shear wave indices was tested by One way ANOVA test, with a p value<0.05 considered statistically significant.
Results: Our study found that strain value and strain ratio were significantly elevated in the non-fertile group compared to the fertile group. The resistive index of the intraparenchymal arteries did not show any difference between infertile and fertile men.
Conclusions: Hence, we concluded that strain value and strain ratio are important investigative tools in the evaluation of male infertility. However, since our study was conducted on a small sample, larger large-scale studies are useful in establishing a concrete conclusion
Doppler sonographic evaluation of intrauterine growth restriction of fetus and its correlation with perinatal outcomes among the population of riverine (char) areas of Barpeta Assam
Background: Intrauterine growth restriction (IUGR) also known as fetal growth restriction (FGR), has been associated with a variety of detrimental perinatal outcomes. FGR is defined as estimated fetal weights (EFW) or abdominal circumference (AC) that fall within the third, or tenth percentiles with abnormal doppler parameters. FGR affects 10-15% of all pregnancies around the world.
Methods: Prospective observational study of singleton pregnant women complicated by FGR were enrolled during the study period from September 2021 to August 2022. 100 patients were included in the study.
Results: Abnormal umbilical artery flow was seen in 30% of cases, out of which 83% (25) had abnormal perinatal outcome. Out of 100 cases, live births were reported in 94%, stillbirths in 4%, and IUDs in 2%. There were 16 neonatal deaths and 15 neonatal complications among the adverse perinatal outcomes. Intraventricular hemorrhage and neonatal sepsis were the two leading causes of death. Neonatal sepsis, necrotizing enterocolitis and hypoxic ischemic injury was the leading cause of morbidity. Reverse end diastolic umbilical artery Doppler and bilateral uterine artery notch had 100% mortality. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of umbilical artery in predicting perinatal outcome in IUGR were 80.65%, 92.75%, 83.33% 91.43% and 89.47% respectively.
Conclusions: Umbilical artery PI is the most sensitive parameter and had highest positive and negative predictive value and Accuracy in relation to adverse perinatal outcomes
Providers\u27 attitudes and practices regarding emergency contraception in India: Key findings
This policy brief reports key findings of a study in India that explored providers’ knowledge of how emergency contraception (ECP) works and its safety and effectiveness, their perceptions of the frequency of repeat use, their provision of ECP, and their attitudes toward women who seek it. Many of the findings of this study are encouraging. Most providers believed that ECP is an effective and safe method to prevent pregnancy and that it cannot induce abortion, and half supported the over-the-counter provision of ECP. Nevertheless, the study revealed many biases and gaps in knowledge. Recommendations include a number of ways to increase education and information about ECPs
Providers\u27 and key opinion leaders\u27 attitudes, beliefs, and practices regarding emergency contraception in India: Final survey report
The Population Council undertook this study to assess the knowledge, attitudes, and practices regarding emergency contraception (ECPs) among providers in public and private facilities and pharmacies in India. This study’s objectives were: 1) to assess providers’ knowledge of ECP’s biological mechanism; 2) to understand providers’ knowledge and attitudes about ECP’s safety, effectiveness, and availability as an over-the-counter drug; and 3) to identify providers’ definitions of “repeated use” and profiling of women who are “repeated users” of ECP. The study recommends intervention programs and advocacy strategies to increase knowledge and access to ECP
Role of renal doppler ultrasonography in evaluating renal haemodynamics in diabetic patients and its correlation with laboratory parameters (serum HbA1C and serum creatinine)
Background: Due to high prevalence of Diabetes Mellitus in India, Diabetic nephropathy is on the rise. Diabetic Nephropathy is the leading cause of End stage renal disease and the major factor responsible for renal transplantation. Grey scale ultrasound can detect morphologic renal parenchymal changes late in the disease but the functional haemodynamic changes can be detected early on, by the means of doppler indices such as Resistive Index (RI) and Pulsatility Index (PI). Hence, application of renal doppler can aid in the diagnosis of early nephropathic changes to allow early medical intervention, therefore improving disease prognosis.
Methods: Renal doppler ultrasonography was performed in 64 diabetic individuals, in the main renal artery and at the interlobar arteries of both kidneys in the upper pole, interpolar region, and lower pole. RI and PI were obtained for each artery and averaged. The correlation between the Mean RI and Mean PI, each with HbA1c and serum creatinine was checked for every patient using relevant statistical tests.
Results: Mean RI and PI in study participants were above the normal range. RI and PI both showed a statistically significant positive correlation with serum creatinine, HbA1c as well as the age of the patient and duration of diabetes mellitus (p<0.001). Â
Conclusions: Evaluation of renal doppler indices while correlating them with laboratory parameters can help slow disease progression. The patient can be provided with medical intervention at the early stage on detection of altered renal indices, hence reducing morbidity and mortality and significantly improving disease prognosis and outcome
Key opinion leaders\u27 views regarding emergency contraception in India
This policy brief explores the views of key opinion leaders (KOLs) in the field of reproductive health and family welfare on provision of emergency contraception (ECPs). The study’s objective was to gain a better understanding of how the attitudes and beliefs of KOLs might influence policy and program implementation, either encouraging or opposing ECP promotion and service delivery. Results suggest strong support by the majority of KOLs to continue the sale of ECP as an over-the-counter drug. KOLs also emphasized the importance of comprehending and addressing the main barriers to ECP provision and use: poor knowledge, lack of training, moral reservations, biases, and misus
A case of partial androgen insensitivity syndrome with undescended testis and clitoromegaly
Androgen insensitivity syndrome is a rare disorder of sex development that results from genetic mutations affecting the androgen receptor. Recently, we encountered a case of a 13-year-old individual who had been raised as female and sought medical attention for primary amenorrhea, which led to the discovery of partial androgen insensitivity syndrome. Early detection and gonad removal are necessary to mitigate the risk of cancer. Additional management steps such as corrective surgery and psychological support can also be valuable
Attitudes, beliefs, and practices of providers and key opinion leaders on emergency contraception in India
The Population Council undertook this study to assess the knowledge, attitudes, and practices regarding emergency contraception (ECP) among providers in public and private facilities and pharmacies in India. The objectives of the study were to: assess providers\u27 knowledge of ECP\u27s biological mechanism; understand providers\u27 knowledge and attitudes about ECP\u27s safety, effectiveness, and availability as an OTC drug; and identify providers\u27 definitions of “repeated use” and profiling women who are “repeated users” of ECP. This study\u27s findings show that most providers, including doctors and some KOLs, were incorrectly informed about ECP\u27s mechanism of action. Service guidelines are necessary for accurate and adequate information on ECPs and could be included in the training curricula of all doctors, nurses, and pharmacists. As part of corporate social responsibility, medical representatives of different ECP manufacturing firms could also play a significant role in educating pharmacists about ECP
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