Molecular communication in fluid media: The additive inverse Gaussian noise channel

We consider molecular communication, with information conveyed in the time of release of molecules. The main contribution of this paper is the development of a theoretical foundation for such a communication system. Specifically, we develop the additive inverse Gaussian (IG) noise channel model: a channel in which the information is corrupted by noise with an inverse Gaussian distribution. We show that such a channel model is appropriate for molecular communication in fluid media - when propagation between transmitter and receiver is governed by Brownian motion and when there is positive drift from transmitter to receiver. Taking advantage of the available literature on the IG distribution, upper and lower bounds on channel capacity are developed, and a maximum likelihood receiver is derived. Theory and simulation results are presented which show that such a channel does not have a single quality measure analogous to signal-to-noise ratio in the AWGN channel. It is also shown that the use of multiple molecules leads to reduced error rate in a manner akin to diversity order in wireless communications. Finally, we discuss some open problems in molecular communications that arise from the IG system model.Comment: 28 pages, 8 figures. Submitted to IEEE Transactions on Information Theory. Corrects minor typos in the first versio

Vaginal birth in singleton breech:revisited

Background: The purpose of the study was to analyze maternal and perinatal outcome according to mode of delivery in singleton breech presentation retrospectively in a tertiary care center.Methods: This was a retrospective observational study done in KEM Hospital, during 2012 to 2013. Maternal and perinatal outcome was studied retrospectively. The data was collected from the mother's medical records. The neonatology records were also examined. Primary outcomes included neonatal mortality, morbidity and maternal morbidity.Results: Out of 100 selected patients; 27 delivered vaginally and 73 underwent lower segment caesarean section (LSCS). Perinatal mortality was 3%. Two out of 3 were delivered vaginally and 1 underwent LSCS. Perinatal morbidity was 1% in vaginal delivery. Maternal morbidity was 2%, both patients underwent emergency LSCS. There was no maternal mortality in the study.Conclusions: Delivery of breech fetus when labor and delivery is supervised and or conducted by experienced obstetrician lowers maternal morbidity, neonatal morbidity and mortality

Surface runoff estimation using geographic information system and soil conservation service-curve number method for sub catchments of Karamadai, Tamil Nadu

Water conservation becomes essential as the resource becomes scarcer. The most important step in managing water resources is estimating watershed runoff generated from rainfall, as the runoff and rainfall are the key factors in determining water availability for surface storage and groundwater recharge. So, this study is mainly focused on estimating the surface runoff generated from the three sub-catchments of Karamadai, Tamil Nadu, India, using the heavy to extreme daily rainfall events received in the study area within the span of 20 years (2000–2019). The study was performed in the ArcGIS environment using remote sensing data. The SCSCN (Soil Conservation Service-Curve Number) method was used to estimate surface runoff. The changes in the land use in each sub-catchment were analysed in each decade and studied for their impact on the runoff depth. The land use and land cover classification map of the study area was prepared from LISS III satellite imagery for the years 2006 and 2016 by using supervised classification. The curve number was assigned based on land use as well as the hydrologic soil group. The weighted curve number was calculated from the area under each land use and then used to calculate storm runoff. The maximum runoff occurred in 2011 in all the catchments of the Karamadai block. It was found that more runoff occurred in the Mandrai Pallam catchment compared to Periya Pallam and Pare Pallam, as the Mandrai Pallam catchment had less soil moisture retention capacity than the other two catchments. So, more priority must be given to this catchment while planning to implement the soil and water conservation measures

Carotid Stenting in a Nonagenarian Patient

Carotid artery stenosis is a disabling disease in all age groups. Elderly people are more prone to recurrent strokes due to advancing age and multiple co-morbidities. Treatment options for symptomatic carotid stenosis in the very elderly are the same as in younger patients although with a higher operative risk. We describe a successful case of carotid artery stenting in a nonagenarian with symptomatic carotid artery stenosis, a subgroup for whom treatment options are rarely discussed in guidelines