Rahul Raj - Academia.edu (original) (raw)

Papers by Rahul Raj

Surgical neurology international, 2017

Neurosurgeons devoted to bypass neurosurgery or revascularization neurosurgery are becoming scarc... more Neurosurgeons devoted to bypass neurosurgery or revascularization neurosurgery are becoming scarcer. From a practical point of view, "bypass neurosurgeons" are anastomosis makers, vessels technicians, and time-racing repairers of vessel walls. This requires understanding the key features and hidden tricks of bypass surgery. The goal of this paper is to provide simple and inexpensive tricks for taming the art of bypass neurosurgery. Most of these tricks and materials described can be borrowed, donated, or purchased inexpensively. We performed a review of relevant training materials and recorded videos for training bypass procedures for 3 years between June 2014 and July 2017. In total, 1,300 training bypass procedures were performed, of which 200 procedures were chosen for this paper. A training laboratory bypass procedures is required to enable a neurosurgeon to develop the necessary skills. The important skills for training bypass procedures gained through meticulous prac...

The Learning Organization, 2016

Purpose This paper has three purposes – first, to establish the direction of relationship between... more Purpose This paper has three purposes – first, to establish the direction of relationship between market orientation (MO) and organizational learning (OL); second, to assess the effect of MO and OL on organizational innovativeness (OI); and third, to examine the mediating role of OL on the relationship between MO and innovativeness. Design/methodology/approach This research was carried out with a sample size of 321 respondents from Indian private and government/public sector industries, applying structural equation modeling (maximum likelihood estimation technique) using AMOS 16. To check the mediation, the study adopts the method suggested by Baron and Kenny (1986). Findings The study finds that MO acts as an antecedent to OL, and the direct effect of both the variables on innovativeness is positive. The study also exhibits that though OL plays a role of mediator between MO and innovativeness, yet the mediation is partial. However, the study also demonstrates the dominance of OL ov...

Intensive Care Medicine, 2021

Background: In patients with severe brain injury, withdrawal of life-sustaining measures (WLSM) i... more Background: In patients with severe brain injury, withdrawal of life-sustaining measures (WLSM) is common in intensive care units (ICU). WLSM constitutes a dilemma: instituting WLSM too early could result in death despite the possibility of an acceptable functional outcome, whereas delaying WLSM could unnecessarily burden patients, families, clinicians, and hospital resources. We aimed to describe the occurrence and timing of WLSM, and factors associated with timing of WLSM in European ICUs in patients with traumatic brain injury (TBI). Methods: The CENTER-TBI Study is a prospective multi-center cohort study. For the current study, patients with traumatic brain injury (TBI) admitted to the ICU and aged 16 or older were included. Occurrence and timing of WLSM were documented. For the analyses, we dichotomized timing of WLSM in early (< 72 h after injury) versus later (≥ 72 h after injury) based on recent guideline recommendations. We assessed factors associated with initiating WLSM early versus later, including geographic region, center, patient, injury, and treatment characteristics with univariable and multivariable (mixed effects) logistic regression. Results: A total of 2022 patients aged 16 or older were admitted to the ICU. ICU mortality was 13% (n = 267). Of these, 229 (86%) patients died after WLSM, and were included in the analyses. The occurrence of WLSM varied between regions ranging from 0% in Eastern Europe to 96% in Northern Europe. In 51% of the patients, WLSM was early. Patients in the early WLSM group had a lower maximum therapy intensity level (TIL) score than patients in the later WLSM group (median of 5 versus 10) The strongest independent variables associated with early WLSM were one unreactive pupil (odds ratio (OR) 4.0, 95% confidence interval (CI) 1.3-12.4) or two unreactive pupils (OR 5.8, CI 2.6-13.1) compared to two reactive pupils, and an Injury Severity Score (ISS) if over 41 (OR per point above 41 = 1.1, CI 1.0-1.1). Timing of WLSM was not significantly associated with region or center. Conclusion: WLSM occurs early in half of the patients, mostly in patients with severe TBI affecting brainstem reflexes who were severely injured. We found no regional or center influences in timing of WLSM. Whether WLSM is always appropriate or may contribute to a self-fulfilling prophecy requires further research and argues for reluctance to institute WLSM early in case of any doubt on prognosis.

Unmanned Aerial Vehicle: Applications in Agriculture and Environment, 2019

Farming in developing countries is majorly dependent on the traditional knowledge of farmers, wit... more Farming in developing countries is majorly dependent on the traditional knowledge of farmers, with unscientific agricultural practices commonly implemented, leading to low productivity and degradation of resources. Moreover, mechanization has not been integral to farming, and thus managing a farm is a time-consuming and labor-intensive process. Consequently, precision agriculture (PA) offers great opportunities for improvement. Using geographic information and communication technology (Geo-ICTs) principles, PA offers the opportunity for a farmer to apply the right amount of treatment at the right time and at the right location in the farm. However, in order to collect timely high-resolution data, drone-based sensing and image interpretation is required. These high-resolution images can give detailed information about the soil and crop condition, which can be used for farm management purposes. Leaf area index, normalized difference vegetation index, photochemical reflectance index, crop water stress index, and other such vegetation indices can provide important information on crop health. Temporal changes in these indices can give vital information about changes in health and canopy structure of the crop over time, which can be related to its biophysical and biochemical stress. These stresses may have occurred due to insufficient soil nutrient, inappropriate soil moisture, or pest attack. Through UAV-based PA, stressed areas can be identified in real time, and some corrective measures can also be carried out (e.g., fertilizer and pesticide spraying). Moreover, the advantages and different approaches to integrate the UAV data in the crop models are also described.

Journal of Neurology, 2020

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Acta Neurochirurgica, 2020

Neurorehabilitation and Neural Repair, 2020

Background Although rehabilitation is beneficial for individuals with traumatic brain injury (TBI... more Background Although rehabilitation is beneficial for individuals with traumatic brain injury (TBI), a significant proportion of them do not receive adequate rehabilitation after acute care. Objective Therefore, the goal of this prospective and multicenter study was to investigate predictors of access to rehabilitation in the year following injury in patients with TBI. Methods Data from a large European study (CENTER-TBI), including TBIs of all severities between December 2014 and December 2017 were used (N = 4498 patients). Participants were dichotomized into those who had and those who did not have access to rehabilitation in the year following TBI. Potential predictors included sociodemographic factors, psychoactive substance use, preinjury medical history, injury-related factors, and factors related to medical care, complications, and discharge. Results In the year following traumatic injury, 31.4% of patients received rehabilitation services. Access to rehabilitation was positiv...

SPE Improved Oil Recovery Conference, 2020

The paper discusses the alkaline surfactant polymer (ASP) flood pilot design including formulatio... more The paper discusses the alkaline surfactant polymer (ASP) flood pilot design including formulation development, pilot area selection, well and pattern type, slug size and sequence, slug viscosity etc for the Bhagyam field. It also discusses the various lab, well and reservoir surveillance techniques planned for the baseline, ASP flood monitoring, residual oil saturation and incremental recovery estimates from the pilot. The Bhagyam is an onshore field in the Rajasthan state of western India and is part of Mangala-Bhagya m- Aishwariya (MBA) development in the Barmer basin. The main producing unit is Fatehgarh multi -storied fluvial sand stone. Reservoir quality is excellent with permeability in the range of 1 to 10 Darcy and porosity in the range of 25-30%. The crude oil is moderately viscous (15 to 500 cP) and highly active with TAN (total acid number) value of ~2 mgKOH/gm. All the reservoir and fluid properties together with low salinity (5000 ppm) and moderate temperature (54 degC...

Scandinavian journal of trauma, resuscitation and emergency medicine, Jan 25, 2017

Intensive care scoring systems are widely used in intensive care units (ICU) around the world for... more Intensive care scoring systems are widely used in intensive care units (ICU) around the world for case-mix adjustment in research and benchmarking. The aim of our study was to investigate the usefulness of common intensive care scoring systems in predicting mid-term mortality in patients with spontaneous intracerebral hemorrhage (ICH) treated in intensive care units (ICU). We performed a retrospective observational study including adult patients with spontaneous ICH treated in Finnish ICUs during 2003-2012. We used six-month mortality as the primary outcome of interest. We used logistic regression to customize Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) II and Sequential Organ Failure Assessment (SOFA) for six-month mortality prediction. To assess the usefulness of the scoring systems, we compared their discrimination and calibration with two simpler models consisting of age, Glasgow Coma Scale (GCS) score, and premorbid funct...

PLoS medicine, 2017

Previous epidemiological studies suggest that working-aged persons with a history of moderate-to-... more Previous epidemiological studies suggest that working-aged persons with a history of moderate-to-severe traumatic brain injury (TBI) may have an increased risk for developing neurodegenerative disease (NDD) while persons with a history of mild TBI do not. In this comprehensive nationwide study in Finland, we assessed the risk of NDD and history of moderate-to-severe TBI in the working-age population. We performed a population-based follow-up study using the Finnish Care Register for Health Care to identify all persons between the ages of 18 and 65 years hospitalized during 1987-2014 due to TBI who did not have a baseline NDD diagnosis. We compared the risk of hospitalization with NDD between persons hospitalized due to moderate-to-severe TBI (intracranial lesions) and persons hospitalized due to mild TBI (no intracranial lesions). Follow-up NDD diagnoses were recorded from 1 year following the TBI to the end of 2014. NDD diagnoses included dementia, Parkinson disease, and amyotrophi...

International Petroleum Technology Conference, 2016

Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, 2016

Background: Differences in outcomes after traumatic brain injury (TBI) between neurosurgical cent... more Background: Differences in outcomes after traumatic brain injury (TBI) between neurosurgical centers exist, although the reasons for this are not clear. Thus, our aim was to assess the association between the annual volume of TBI patients and mortality in neurosurgical intensive care units (NICUs). Methods: We collected data on all patients treated in the five Finnish university hospitals to examine all patients with TBI treated in NICUs in Finland from 2009 to 2012. We used a random effect logistic regression model to adjust for important prognostic factors to assess the independent effect of ICU volume on 6-month mortality. Subgroup analyses were performed for patients with severe TBI, moderate-to-severe TBI, and those who were undergoing mechanical ventilation or intracranial pressure monitoring. Results: Altogether 2,328 TBI patients were treated during the study period in five NICUs. The annual TBI patient volume ranged from 61 to 206 patients between the NICUs. Univariate analysis, showed no association between the NICUs' annual TBI patient volume and 6-month mortality (p = 0.063). The random effect model showed no independent association between the NICUs' annual TBI patient volume and 6-month mortality (OR = 1.000, 95% CI = 0.996-1.004, p = 0.876). None of the pre-defined subgroup analyses indicated any association between NICU volume and patient mortality (p > 0.05 for all). Discussion and Conclusion: We did not find any association between annual TBI patient volume and 6-month mortality in NICUs. These findings should be interpreted taking into account that we only included NICUs, which by international standards all treated high volumes of TBI patients, and that we were not able to study the effect of NICU volume on neurological outcome.

Geoscientific Model Development Discussions, 2016

Parameters of a process-based forest growth simulator are difficult or impossible to obtain from ... more Parameters of a process-based forest growth simulator are difficult or impossible to obtain from field observations. Reliable estimates can, however, be obtained using calibration against observations of output and state variables. In this study, we present a Bayesian framework to calibrate the widely used process-based simulator BIOME-BGC against estimates of gross primary production (GPP) data. We used GPP partitioned from flux tower measurements of a net ecosystem exchange over a 55 year old Douglas fir stand as an example. The uncertainties of both the BIOME-BGC parameters and the simulated GPP were estimated. The calibrated parameters leaf and fine root turnover (LFRT), ratio of fine root carbon to leaf carbon (FRC : LC), ratio of carbon to nitrogen in leaf (C : Nleaf), canopy water interception coefficient (Wint), fraction of leaf nitrogen in Rubisco (FLNR), and soil rooting depth (SD) characterize the photosynthesis and carbon and nitrogen allocati...

World Neurosurgery, 2015

Disadvantages of a contralateral approach (CA) are deep and narrow surgical corridors and inconsi... more Disadvantages of a contralateral approach (CA) are deep and narrow surgical corridors and inconsistent ability to achieve proximal control of the supraclinoid internal carotid artery (ICA). However, a CA remains as microsurgical option for selected internal carotid artery-ophthalmic segment (ICA-opht) aneurysms. To describe transient cardiac arrest induced by adenosine as an alternative tool to obtain proximal vascular control and soften the aneurysm sac in selected patients while performing a CA. From January 1998 to December 2013, we retrospectively identified 30 patients with ICA-opht segment aneurysms treated through a CA. Of those, 8 patients received intravenous bolus of adenosine to induce transient cardiac arrest for softening of the aneurysm sac. We reviewed preoperative clinical status, characteristics of the contralateral aneurysm, adenosine doses, asystole time, recovery of normal circulation, outcome and complications. No preoperative cardiac or pulmonary pathologies appeared on the studied population. All contralateral ICA-opht segment aneurysms were unruptured, small and saccular in shape. The reason to induce transient cardiac arrest was the impossibility to apply a temporary clip on the parent contralateral supraclinoid ICA. The median dose of adenosine was 22.5 mg (range 5-50 mg) and the asystole time ranged 20-40 seconds. All patients (n=8) showed good postoperative outcomes. No brain infarction or cardiac complications appeared postoperatively. In selected patients, transient cardiac arrest induced by adenosine during a contralateral approach allows a brief flow arrest and softening of the aneurysm for a safer exposure and clipping.

Journal of sports science & medicine, 2015

A career as an elite-class male athlete seems to improve metabolic heath in later life and is als... more A career as an elite-class male athlete seems to improve metabolic heath in later life and is also associated with longer life expectancy. Telomere length is a biomarker of biological cellular ageing and could thus predict morbidity and mortality. The main aim of this study was to assess the association between vigorous elite-class physical activity during young adulthood on later life leukocyte telomere length (LTL). The study participants consist of former male Finnish elite athletes (n = 392) and their age-matched controls (n = 207). Relative telomere length was determined from peripheral blood leukocytes by quantitative real-time polymerase chain reaction. Volume of leisure-time physical activity (LTPA) was self-reported and expressed in metabolic equivalent hours. No significant difference in mean age-adjusted LTL in late life (p = 0.845) was observed when comparing former male elite athletes and their age-matched controls. Current volume of LTPA had no marked influence on mean...

12th International Conference on Fiber Optics and Photonics, 2014

ABSTRACT 1D gold gratings are optimally designed using Rigorous Couple Wave Analysis (RCWA) to re... more ABSTRACT 1D gold gratings are optimally designed using Rigorous Couple Wave Analysis (RCWA) to realize angle dependent color shifting property. This interesting optical property is experimentally confirmed on the gratings fabricated using Dip pen nanolithography.