Optimal Mean Squared Error Imaging

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77345/1/AIAA-2002-4952-350.pd

Study of length of umbilical cord and fetal outcome: a study of 1000 deliveries

Background: Human embryo develops inside the body of the mother. One of the important part of the fetoplacental unit is the umbilical cord. The umbilical cord is the lifeline of the fetus. Objective of present study was to investigate the correlation of umbilical cord length with fetal parameters like APGAR score, sex, weight, and length, and its effect on labor.Methods: This prospective study conducted in the Department of OBG of VIMS, Bellary, from 1st February 2016 to 31st January 2017. The 1000 pregnant women of >37 weeks were studied following delivery for length of umbilical cord, any loop around neck, trunk, shoulder and number of loops of cord; knots of cord etc. Fetal parameters recorded were sex, weight, and length of the newborn and APGAR score at 1 and 5 min.Results: Cord length varied from 22 to 126 cm. The mean cord length was 66 cm (±10 cm). Maximum cases have cord length of 61and 70 cm. Lower 5th percentile and upper 5th percentile considered as short and long cord. Short-cord group was associated with significantly higher (p<0.05) incidence of LSCS cases. The incidence of all types of cord complications increases as the cord length increases (p<0.001). Nuchal cords had higher mean cord length and as the number of loops in a nuchal cord increases to two or more loops, the operative interference and fetal heart abnormalities increases. Fetal heart rate abnormalities and birth asphyxia increase with extremes of cord length (p<0.001).Conclusions: Short and long cords are associated with increased incidence of cord complications, operative interference, intrapartum complications, increased fetal heart rate abnormalities, and birth asphyxia. But cord length did not vary according to the weight, length, and sex of the baby

Generalization of escape rate from a metastable state driven by external cross-correlated noise processes

We propose generalization of escape rate from a metastable state for externally driven correlated noise processes in one dimension. In addition to the internal non-Markovian thermal fluctuations, the external correlated noise processes we consider are Gaussian, stationary in nature and are of Ornstein-Uhlenbeck type. Based on a Fokker-Planck description of the effective noise processes with finite memory we derive the generalized escape rate from a metastable state in the moderate to large damping limit and investigate the effect of degree of correlation on the resulting rate. Comparison of the theoretical expression with numerical simulation gives a satisfactory agreement and shows that by increasing the degree of external noise correlation one can enhance the escape rate through the dressed effective noise strength.Comment: 9 pages, 1 figur

Seroprevalence of transfusion transmitted infections in voluntary and replacement blood donors in a tertiary care hospital blood bank of Anantapur, Andhra Pradesh, India: 5 years retrospective study

Background: Critical part of transfusion is effective screening of TTI, to reduce the risk of transmission is as safe as possible. The present study has undertaken to focus on seroprevalence of TTIs among both voluntary and replacement donors and also to project epidemiological data of TTIs in this community.Methods: This is a retrospective study conducted from January 2014 to December 2018. All blood samples collected from donors were screened for HIV, HBV, HCV, Syphilis and malaria according to blood bank policy. Before drawing blood, donors were asked to fill pre structured Blood bank questionnaire and consent form.Results: In this present 5-year study, total number of blood donor population was 54937, among them voluntary donors were 33891 and replacement donors were 21046. Out of 33891 voluntary donors, 33486(98.8%) were males and remaining 405(1.19%) were females. All replacement donors (21046) were males. The seroprevalence of HBV was highest, 1.82% (1003/54937) followed by HCV 0.31% (175/54937) in all the donors. The seropositivity for HIV is 0.23% (129/54937), for syphilis 0.04% (24/54937) and for malaria 0.01% (6/54937).Conclusions: National blood transfusion policy should be strengthening the standards and quality of screening across the country. For blood screening, resources and appropriate screening assays must be available at all health centres

Cosmological Constraints from Galaxy Cluster Velocity Statistics

Future microwave sky surveys will have the sensitivity to detect the kinematic Sunyaev-Zeldovich signal from moving galaxy clusters, thus providing a direct measurement of their line-of-sight peculiar velocity. We show that cluster peculiar velocity statistics applied to foreseeable surveys will put significant constraints on fundamental cosmological parameters. We consider three statistical quantities that can be constructed from a cluster peculiar velocity catalog: the probability density function, the mean pairwise streaming velocity, and the pairwise velocity dispersion. These quantities are applied to an envisioned data set which measures line-of-sight cluster velocities with normal errors of 100 km/s for all clusters with masses larger than $10^{14}$ solar masses over a sky area of up to 5000 square degrees. A simple Fisher matrix analysis of this survey shows that the normalization of the matter power spectrum and the dark energy equation of state can be constrained to better than 10 percent, and the Hubble constant and the primordial power spectrum index can be constrained to a few percent, independent of any other cosmological observations. We also find that the current constraint on the power spectrum normalization can be improved by more than a factor of two using data from a 400 square degree survey and WMAP third-year priors. We also show how the constraints on cosmological parameters changes if cluster velocities are measured with normal errors of 300 km/s.Comment: 4 pages, replaced to match accepted version in ApJ Letter. Table 4 shows parameter constraints for normal velocity error of 300 km/s. Reference adde

Escape rate from a metastable state weakly interacting with a heat bath driven by an external noise

Based on a system-reservoir model, where the reservoir is driven by an external stationary, Gaussian noise with arbitrary decaying correlation function, we study the escape rate from a metastable state in the energy diffusion regime. For the open system we derive the Fokker-Planck equation in the energy space and subsequently calculate the generalized non-Markovian escape rate from a metastable well in the energy diffusion domain. By considering the dynamics in a model cubic potential we show that the results obtained from numerical simulation are in good agreement with the theoretical prediction. It has been also shown numerically that the well known turnover feature can be restored from our model.Comment: 11 pages, 2 figure

Class of self-limiting growth models in the presence of nonlinear diffusion

The source term in a reaction-diffusion system, in general, does not involve explicit time dependence. A class of self-limiting growth models dealing with animal and tumor growth and bacterial population in a culture, on the other hand are described by kinetics with explicit functions of time. We analyze a reaction-diffusion system to study the propagation of spatial front for these models.Comment: RevTex, 13 pages, 5 figures. To appear in Physical Review

Study of various congenital anomalies in fetal and neonatal autopsy

Background: The study of dead is to save the livings. The growing awareness that still births and infant mortalities are unable to reduction has led to a wide spread desire for more information regarding the cause of these deaths. Congenital malformations have become important cause of fetal and neonatal (perinatal) mortality in developed countries and would very soon be increasingly important determinants of fetal and neonatal mortality in developing countries like India. In spite of antenatal diagnostic modality still the fetal autopsy plays the vital role in the conformation as well as identification of congenital anomalies and also for the counseling of the parents, to prevent the fetal congenital anomalies in further pregnancies. This study was undertaken with the purpose of finding out cause of death during the perinatal period at government maternity hospital and pediatric department S.V.R.R.G.G.H. & S.V. medical college Tirupati, and to study the clinical and pathological findings (Gross & microscopic) in fetal and neonatal death.Methods: The present study of congenital anomalies in fetal and neonatal deaths was done at S.V. medical college, Tirupati, over a time period of 2 years from September 2008 to 2010 August. Consent for autopsy in requested compassionately, respectfully and fully informed. The present study included dead fetus and neonates with gestational age above 20 weeks of intra uterine life and within 7 days of post natal life. All fetuses of gestational age <20 weeks and all neonates above 7 days of age were excluded from the study. The study also obtained clearance from the ethical committee of the institution. Autopsy was performed by standard technique adopted by Edith L. Potter. External and internal findings followed by histopathological examination, and autopsy findings were compared with available ultrasound findings.Results: A total of 46 Autopsies performed, 40 (87%) were fetal deaths, 6 (13%) were early neonatal deaths. In a total of 46 fetuses, there were 13 male and 33 female babies. On external examination of 46 fetal and Neonatal (perinatal) deaths, 8 (17.39%) babies showed congenital malformation. On internal examination of the 46 fetal and Neonatal (perinatal) deaths, 4 babies showed internal congenital anomalies. A total of 46 anatomical and histopathologic examinations were done among fetal and neonatal (perinatal) deaths. Out of 13 autopsies on male babies, 2 had congenital malformation and 33 autopsies on female babies, 7 had congenital malformations. Congenital anomalies were commonest in the birth weight group of 1000-1500 grams accounting for 9 cases. Malformations of central nervous system (33.33%) were most common followed by musculoskeletal system (16.66%), genitourinary and respiratory system (8.33%) respectively.Conclusion: Most number of perinatal deaths occurred in low birth weight and preterm babies. Study of malformations greatly helpful in genetic counseling and prenatal diagnosis in successive pregnancies

Study of the transient nature of classical Be stars using multi-epoch optical spectroscopy

Variability is a commonly observed property of classical Be stars (CBe) stars. In extreme cases, complete disappearance of the H{\alpha} emission line occurs, indicating a disc-less state in CBe stars. The disc-loss and reappearing phases can be identified by studying the H{\alpha} line profiles of CBe stars on a regular basis. In this paper, we present the study of a set of selected 9 bright CBe stars, in the wavelength range of 6200 - 6700 {\AA}, to better understand their disc transient nature through continuous monitoring of their H{\alpha} line profile variations for 5 consecutive years (2015 -- 2019). Based on our observations, we suggest that 4 of the program stars (HD 4180, HD 142926, HD 164447 and HD 171780) are possibly undergoing disc-loss episodes, whereas one other star (HD 23302) might be passing through disc formation phase. The remaining 4 stars (HD 237056, HD 33357, HD 38708 and HD 60855) have shown signs of hosting a stable disc in recent epochs. Through visual inspection of the overall variation observed in the H{\alpha} EW for these stars, we classified them into groups of growing, stable and dissipating discs, respectively. Moreover, our comparative analysis using the BeSS database points out that the star HD 60855 has passed through a disc-less episode in 2008, with its disc formation happening probably over a timescale of only 2 months, between January and March 2008.Comment: 19 pages, 7 figures, 2 tables, accepted in JAp