Applications of Sentinel-2 satellite data for spatio-temporal mapping of deep pools for monitoring the riverine connectivity and assessment of ecological dynamics: a case from Godavari, a tropical river in India (2016-2021)

Rivers are dynamic ecosystems with diverse habitats that require ample connectivity to ensure the flow of ecosystem services, thus empowering the sustainable development of an entire basin. Geo-spatial tools offer powerful prospects for monitoring of aquatic ecosystems. The usefulness of Sentinel-2 datasets to assess river connectivity has been explored for an un-gauged seasonal river system. The present study was undertaken in five ecologically unique river reaches viz. Wainganga, Wardha, Pranhita, Godavari-mid and Manair in Godavari Basin in the Indian Deccan Plateau to map water spread dynamics at various time scales, i.e., fortnightly, monthly, seasonal, annual and demi-decadal during 2016-2021. The maximum value of perennial water spread per square kilometre of total floodplain area (2016-2021), determined using Sentinel-2 imageries, was observed in river Wardha (0.18) followed by Pranhita (0.12) and Wainganga (0.11). The water spread showed a decreasing trend, while the number of patches in the river corridor increased over time from post-monsoon to pre-monsoon season. The copious perennial habitat with relatively larger patches, incessant flow in river Pranhita and obstructed flow, large-sized patches reported in river Wardha during summer months, hold importance in terms of providing refuge to aquatic biota. This study provides evidence for the impact of water projects on spatio-temporal water spread dynamics in Godavari Basin. The demonstrated utility of Sentinel-2 imagery coupled with gauge station measurements for river continuity assessment and deep pool mapping would aid in enhancing our understanding on environmental flow at a spatial scale, which in turn would aid in effective river management to achieve the Sustainable Development Goals. The implications of this study for sustainable environmental management and limitations are also discussed.

Epidural Fluid Collections After Cranioplasty

Background

Common complications following cranioplasty (CP) include infections, seizures, bone flap resorption, and intra-cranial hemorrhages. Epidural fluid collections (EFCs), often seen in the immediate post-operative scan as hypo-dense accumulations below the bone flap, have been very infrequently discussed in the literature as in the majority of the cases, they are small, get resorbed spontaneously, and usually do not cause neurological deficits.

Objective

To document our experience with EFCs that needed re-operation and analyze their clinical and radiological findings.

Materials and Methods

We describe a series of six cases of symptomatic EFCs following CP that necessitated re-operation in a series of 89 cases over 7 years.

Conclusions

EFCs following CP have a different pathogenetic mechanism compared to post-operative epidural hemorrhages. Meticulous surgical techniques can reduce their incidence. Symptomatic EFCs can be evacuated by either re-opening the flap or placing burr holes in the replaced bone. EFCs may become symptomatic even a few days after CP.

Postoperative Salvage Decompressive Craniotomy: Usefulness of The Simple Posteriorly Directed Release Incision in Adequately Expanding Frontotemporal Flaps

Salvage decompressive craniotomies performed following complications after initial planned craniotomies may be inadequate if they are only restricted to removal of the small previously replaced bone flap with some additional nibbling of bone from the surrounding craniotomy margins by retracting the skin. To achieve the aim of adequately decreasing intracranial pressure without affecting wound healing, fresh incisions need to be placed to expand the craniotomy adequately while not compromising vascularity of the scalp. The rationale and safety of the simple posteriorly placed release incision to expand frontotemporal flaps is described.

Flecked Calcifications in Scalp Tumors: Two Cases of Giant Ulcerated Trichilemmal Cysts

In the article, the classical radiological findings in trichilemmal cysts of the scalp are described.

Allergic Contact Dermatitis Due to Cervical Collar

Cervical collars are routinely applied in neurosurgical units following trauma or cervical spine operations. We describe a case of florid allergic contact dermatitis that developed as a complication following collar application in a postoperative patient.

ACTA2-Related Dysgyria: An Under-Recognized Malformation of Cortical Development

BACKGROUND AND PURPOSE

Pathogenic variants in the ACTA2 gene cause a distinctive arterial phenotype that has recently been described to be associated with brain malformation. Our objective was to further characterize gyral abnormalities in patients with ACTA2 pathogenic variants as per the 2020 consensus recommendations for the definition and classification of malformations of cortical development.

MATERIALS AND METHODS

We performed a retrospective, multicentric review of patients with proved ACTA2 pathogenic variants, searching for the presence of malformations of cortical development. A consensus read was performed for all patients, and the type and location of cortical malformation were noted in each. The presence of the typical ACTA2 arterial phenotype as well as demographic and relevant clinical data was obtained.

RESULTS

We included 13 patients with ACTA2 pathogenic variants (Arg179His mutation, n = 11, and Arg179Cys mutation, n = 2). Ninety-two percent (12/13) of patients had peri-Sylvian dysgyria, 77% (10/13) had frontal dysgyria, and 15% (2/13) had generalized dysgyria. The peri-Sylvian location was involved in all patients with dysgyria (12/12). All patients with dysgyria had a characteristic arterial phenotype described in ACTA2 pathogenic variants. One patient did not have dysgyria or the characteristic arterial phenotype.

CONCLUSIONS

Dysgyria is common in patients with ACTA2 pathogenic variants, with a peri-Sylvian and frontal predominance, and was seen in all our patients who also had the typical ACTA2 arterial phenotype.

Interactive effect of elevated tropospheric ozone and carbon dioxide on radiation utilisation, growth and yield of chickpea (Cicer arietinum L.)

An experiment was conducted in the Free Air Ozone and Carbon dioxide Enrichment (FAOCE) facility to study the impact of elevated O₃, CO₂ and their interaction on chickpea crop (cv. Pusa-5023) in terms of phenology, biophysical parameters, yield components, radiation interception and use efficiency. The crop was exposed to elevated O₃ (EO:60ppb), CO₂ (EC:550 ppm) and their combined interactive treatment (ECO: EC+EO) during the entire growing season. Results revealed that the crop's total growth period was shortened by 10, 14 and 17 days under elevated CO₂, elevated O₃ and the combined treatment, respectively. Compared to ambient condition, the leaf area index (LAI) under elevated CO₂ was higher by 4 to 28%, whilst it is reduced by 7.3 to 23.8% under elevated O₃. The yield based radiation use efficiency (RUE_y) was highest under elevated CO₂ (0.48 g MJ^-1), followed by combined (0.41 g MJ^-1), ambient (0.38 g MJ^-1) and elevated O₃ (0.32 g MJ^-1) treatments. Elevated O₃ decreased RUE_y by 15.78% over ambient, and the interaction results in a 7.8% higher RUE_y. The yield was 31.7% more under elevated CO₂ and 21.9% lower in elevated O₃ treatment as compared to the ambient. The combined interactive treatment recorded a higher yield as compared to ambient by 9.7%. Harvest index (HI) was lowest under elevated O₃ (36.10%), followed by ambient (39.18%), combined (40.81%), and highest was under elevated CO₂ (44.18%). Chickpea showed a positive response to elevated CO₂ resulting a 5% increase in HI as compared to ambient condition. Our findings quantified the positive and negative impacts of elevated O₃, CO₂ and their interaction on chickpea and revealed that the negative impacts of elevated O₃ can be compensated by elevated CO₂ in chickpea. This work promotes the understanding of crop behaviour under elevated O₃, CO₂ and their interaction, which can be used as valuable inputs for radiation-based crop simulation models to simulate climate change impact on chickpea crop.

Twin Root Replacement in Congenital Heart Disease: Expert Technique

In adult congenital heart disease, there are situations that require both the aortic and pulmonary roots to be replaced at the time of a reoperation. This commonly involves the replacement of a previously implanted right ventricle-pulmonary artery conduit in a patient with late aortic root dilation and/or neo-aortic valve dysfunction following the Ross procedure. Similar scenarios are encountered in patients having undergone previous repair of conotruncal anomalies such as truncus arteriosus and tetralogy of Fallot with pulmonary atresia. We describe our standardized technique for twin root replacement.

Procurement of lungs from brain-dead donors

Lung transplantation is the procedure of choice in many patients with end-stage lung disease and is being performed more frequently around the world. However, there continues to be shortage of donor organs with the ever-expanding number of recipients on the waiting list, leading to liberalization of the lung donor selection criteria with increasing acceptance of marginal donors while striving for excellent results. This has placed an increasing emphasis on the technique of donor lung procurement and preservation from marginal donors. Good judgment and procurement techniques are necessary to obtain high-quality donor lungs for transplantation and optimize long-term results. This is a review of our current technique used for the procurement of the lungs from brain-dead donors.

An Umbrella Converse for Data Exchange: Applied to Caching, Computing, and Shuffling

The problem of data exchange between multiple nodes with storage and communication capabilities models several current multi-user communication problems like Coded Caching, Data Shuffling, Coded Computing, etc. The goal in such problems is to design communication schemes which accomplish the desired data exchange between the nodes with the optimal (minimum) amount of communication load. In this work, we present a converse to such a general data exchange problem. The expression of the converse depends only on the number of bits to be moved between different subsets of nodes, and does not assume anything further specific about the parameters in the problem. Specific problem formulations, such as those in Coded Caching, Coded Data Shuffling, and Coded Distributed Computing, can be seen as instances of this generic data exchange problem. Applying our generic converse, we can efficiently recover known important converses in these formulations. Further, for a generic coded caching problem with heterogeneous cache sizes at the clients with or without a central server, we obtain a new general converse, which subsumes some existing results. Finally we relate a “centralized” version of our bound to the known generalized independence number bound in index coding and discuss our bound’s tightness in this context.

Sensitivity analysis of cultivar parameters to simulate wheat crop growth and yield under moisture and temperature stress conditions

Sensitivity of cultivar input parameters were characterised on the outputs of yield and growth variables using a web based crop simulation model Web InfoCrop Wheat. The crop model was assessed for each combination of seventeen input cultivar parameters tested under moisture and temperatures stress conditions in four different ecological regions. Three model outputs, total dry matter at harvest, grain yield at harvest and duration of the crop were chosen for subsequent evaluation. The most dominant cultivar parameters were identified to be TPOPT (Optimum Temp), TTVG (Thermal time for germination to 50% Flowering), KDFMAX (Extinction coefficient of leaves at flowering), GNOCF (Slope of storage organ number/m² to dry matter during storage organ formation), POTGWT (Potential storage organ weight) and PHOTOSENS (Photoperiod sensitivity) which were associated with growth, thermal time accumulation, leaf area index, grain number and photosensitivity. Comparison of crop simulations with all the cultivar parameters incorporated from the experimental observations and those with only the most sensitive cultivar parameters incorporated was performed. Outputs of the crop simulation were significantly correlated with results from the field experiments. The present study could save time and effort in generating all the cultivar parameters required to perform the crop simulation under moisture and temperature stress conditions. The most significant cultivar parameters (TPOPT, TTVG, KDFMAX, GNOCF, POTGWT and PHOTOSENS) identified through the sensitivity analysis conducted in this study could significantly simulate the crop growth and yield of wheat.

Twelve-Year Survival After Resection of Hepatocellular Carcinoma with Right Atrial Tumor Thrombus

INTRODUCTION

A large hepatocellular carcinoma (HCC) with macrovascular invasion is generally considered to have poor prognosis due to unfavorable tumor biology andsuch patients are relegated to palliative options. This report describes long term survival after surgery in a patient with HCC and tumor thrombus in the rightatrium.

METHODS

Case records of the patient, details of follow up visits and surveillance computed tomography scans performed were reviewed. A brief discussion of thesurgical strategy adopted along with outcome of similar cases in literature is presented.

RESULTS

A 60 year old man presented with a HCC in segments 4, 5 with extension of tumor into the middle, left hepatic veins, inferior vena cava and right atrium.Patient underwent extraction of the tumor thrombus from the right atrium under cardiopulmonary bypass along with extended left hepatectomy. He receivedthree cycles of adjuvant chemotherapy with Gemcitabine, Oxaliplatin and Interferon. There was a parietal wall recurrence after 1 year and 10 months whichwas excised. Since then he remains well and is on regular follow up for more than 12 years from his index surgery with no evidence of disease, making himthe longest known survivor with such an advanced presentation.

CONCLUSION

This is an unusual instance where aggressive resection for HCC with right atrial tumor thrombus has resulted in an exceptionally long survival.