284 research outputs found
A multifaceted view of the interplay between gas and radio AGN
The supermassive blackholes inhabiting the centres of massive galaxies become active galactic nuclei (AGN) when the ambient matter gets accreted onto them. This results in the emission of enormous amount of energy which influences the evolution of their host galaxies. In radio-loud AGN, the energy is emitted in the form of collimated jets. These jets and the ambient interstellar medium (ISM) interact and affect each other: while the radio jets make the ISM turbulent and drive fast outflows, a dense ISM slows the growth of these radio jets. Understanding the nature of this jet-ISM interaction and its evolution with redshift is crucial to understand the role of radio AGN in galaxy evolution.In this thesis, we carried out a detailed study of the interaction between radio jets and the cold ISM: atomic (HI) and molecular, in a low-luminosity radio galaxy using the Very Large Array (VLA), European VLBI Network (EVN) and NOrthern Extended Millimeter Array (NOEMA). This resulted in the first discovery of a massive molecular-gas outflow in this AGN, driven single-handedly by radio jets. This showed that kpc-scale jet-ISM interaction in such sources is important for models of galaxy evolution. We further searched for HI in samples of radio AGN at higher redshifts and suggested that the incidence and kinematics of HI in radio AGN does not evolve up to z ~ 0.4 and provided the first evidence for the evolution of cold-gas content in radio AGN environments at z>0.7
mCollector: Sensor-enabled health-data collection system for rural areas in the developing world
Health data collection poses unique challenges in rural areas of the developing world. mHealth systems that are used by health workers to collect data in remote rural regions should also record contextual information to increase confidence in the fidelity of the collected data. We built a user-friendly, mobile health-data collection system using wireless medical sensors that interface with an Android application. The data-collection system was designed to support minimally trained, non-clinical health workers to gather data about blood pressure and body weight using off-the-shelf medical sensors. This system comprises a blood-pressure cuff, a weighing scale and a portable point-of-sales printer. With this system, we introduced a new method to record contextual information associated with a blood-pressure reading using a tablet’s touchscreen and accelerometer. This contextual information can be used to verify that a patient’s lower arm remained well-supported and stationary during her blood-pressure measurement. This method can allow mHealth applications to guide untrained patients (or health workers) in measuring blood pressure correctly. Usability is a particularly important design and deployment challenge in remote, rural areas, given the limited resources for technology training and support. We conducted a field study to assess our system’s usability in rural India, where we logged health worker interactions with the app’s interface using an existing usability toolkit. Researchers analyzed logs from this toolkit to evaluate the app’s user experience and quantify specific usability challenges in the app. We have recorded experiential notes from the field study in this document. We present four contributions to future mHealth projects in this document: \u3e We describe a method for measuring lower-arm stillness and support during a blood-pressure measurement, using an off-the-shelf Android tablet. \u3e We evaluate our method for measuring lower-arm stillness with a preliminary user study of 12 subjects and found that our method can distinguish stationary arms from different types of lower-arm movement with 90% accuracy. \u3e We conduct an experiential study with 28 participants and three app operators. In this study, we evaluate our system’s field usability by deploying it in rural India. \u3e We provide a quantitative usability analysis of our mobile-data-collection app’s interface using an existing usability toolkit
Room temperature soft ferromagnetism in the nanocrystalline form of YCo2 - a well-known bulk Pauli paramagnet
The Laves phase compound, YCo2, is a well-known exchange-enahnced Pauli
paramagnet. We report here that, in the nanocrystalline form, this compound
interestingly is an itinerant ferromagnet at room temperature with a low
coercive-field. The magnitude of the saturation moment (about 1 Bohr-magneton
per formula unit) is large enough to infer that the ferromagnetism is not a
surface phenomenon in these nanocrystallites. Since these ferromagnetic
nanocrystallines are easy to synthesize with a stable form in air, one can
explore applications, particularly where hysteresis is a disadvantage
Quality Estimation of Machine Translated Texts based on Direct Evidence from Training Data
Current Machine Translation systems achieve very good results on a growing
variety of language pairs and data sets. However, it is now well known that
they produce fluent translation outputs that often can contain important
meaning errors. Quality Estimation task deals with the estimation of quality of
translations produced by a Machine Translation system without depending on
Reference Translations. A number of approaches have been suggested over the
years. In this paper we show that the parallel corpus used as training data for
training the MT system holds direct clues for estimating the quality of
translations produced by the MT system. Our experiments show that this simple
and direct method holds promise for quality estimation of translations produced
by any purely data driven machine translation system
Prescribing pattern of drugs in chronic kidney disease patients on hemodialysis at a tertiary care hospital
Background: CKD (chronic kidney disease) is a general term for heterogeneous disorders affecting kidney structure and its function. It is defined as either kidney damage or a decreased glomerular filtration rate of less than 60 mL/min/1.73m2 for 3 or more months. Objective of present work is to study the drug utilization pattern in chronic kidney disease patients undergoing hemodialysis.Methods: After taking the clearance and approval from the institutional ethics committee, a cross sectional prospective observational study conducted on chronic kidney disease (CKD) patients undergoing hemodialysis, in the department of nephrology, of Rajarajeshwari Medical College and Hospital, Bangalore. The data was analyzed descriptively.Results: Study included 52 patients, among them 41 males, 11were females, with a mean age of 47.6yrs. In our study large number pt were suffering from hypertension (HTN) 88.46% (46), in them the calcium channel blocker (CCB) 08.48% (38) was most commonly prescribed anti hypertensive drug. Around 1/3 of pt suffering from diabetes mellitus (DM) 36.53% (19) most of these patients were treated with them treated with oral hypoglycemic agents (OHA), and less than half of pt treated with insulin01.56% (07). Other drugs like phosphate binders (calcium carbonate & acetate) used in 11.16% (50), aspirin in 08.70% (39), statins in 10.04% (45) pt were being most commonly prescribed drugs. Totally 448 drugs were prescribed In 52 pts Ie about 8.61 drugs / prescription, showing poly pharmacy.Conclusions: Patients undergoing hemodialysis with CKD will be having multiple diseases associated, regular monitoring and counseling regarding these diseases and its complication may reduce the incidence of CKD and the mortality and morbidity associated. The poly pharmacy noted in the study found inevitable because of the multifactorial etiologiesinvolved and needful multi-interventional approach towards it
Molecular authentication of green algae Caulerpa (Caulerpales, Chlorophyta) based on ITS and tufA genes from Andaman Islands, India
109-114Indigenous and non-indigenous invasive algal species introduction or prevalence is one of the major concerns to protect the native coastal environment. Globally, several studies have reported the effect of invasive alga Caulerpa on coral reefs. To establish the genetic variation between indigenous and non-indigenous invasive species, attempts have been made to develop molecular identification of Caulerpa algal species available at the Andaman Islands. In this study, 7 visually and morphologically different species belonging to the genus Caulerpa (Chlorophyta) were collected from the intertidal regions of South and Little Andaman Islands, India. The specimens were preliminarily identified based on the morphological characters and genetically mapped using ITS2 and chloroplast tufA gene markers. Six species of the Caulerpa viz. Caulerpa racemosa, C. racemosa var lamourouxii, C. racemosa var macrophysa, C. serrulata, C. fergusonii and C. microphysa were identified using ITS2 gene, and. C. mexicana var pluriseriata was identified using tufA gene. Two varieties, C. mexicana var. pluriseriata and C. racemosa var lamourouxii were found to be invasive to Indian waters. These were earlier reported in Red sea and in Phillipine waters in the pacific ocean. Further studies are needed to elucidate the genetic divergence of the Caulerpa species present in Andaman waters using different molecular markers
Automated Glycan Assembly of Mycobacterial Hexaarabinofuranoside and Docosasaccharide Arabinan (Araf23) Motifs found on Mycobacterium tuberculosis
Mycobacteria are covered in a thick layer of different polysaccharides that helps to avert the innate immune response. Lipoarabinomannan (LAM) and arabinogalactan (AG) are ubiquitously contained in these envelopes, and rapid access to defined oligo- and polysaccharides is essential to elucidate their structural and biological roles. Arabinofuranose (Araf) residues in LAM and AG are connected either via α-1,2-trans linkages that are synthetically straightforward to install or the more challenging β-(1,2-cis) linkages. Herein, it was demonstrated that automated glycan assembly (AGA) can be used to quickly prepare 1,2-cis-β-Araf as illustrated by the assembly of a highly branched arabinan hexasaccharide and a docosasaccharide arabinan (Araf23) motif
Thermal Shock and Oxidation Stability Tests to Grade Plasma Sprayed Functionally Gradient Thermal Barrier Coatings
oai:ojs2.sietjournals.com:article/8Functionally graded layers in thermal barrier coatings reduce the stress gradient between the overlaid ceramic coatings and the underlying metallic component. Introduced to alleviate early onset of spallation of the coating due to thermal expansion mismatch, this facilitates improvement in the life of the component. Conventional thermal barrier coatings typically comprise of duplex layers of plasma sprayed 8% yttria stabilized zirconia (ceramic) coatings on bond coated (NiCrAlY) components/substrates (Inconel 718 for example). This work highlights the superiority of plasma sprayed coatings synthesized from blends of the intermetallic bond coat and ceramic plasma spray powders on Inconel 718 substrates in three-layer configuration over the duplex layered configuration. Assessed through (a) thermal shock cyclic tests (at 1200oC and 1400oC) in laboratory scale basic burner rig test facility and (b) oxidation stability test in high temperature furnace (at 800oC and 1000oC) the functionally graded coatings of certain configurations exhibited more than double the life of the conventional 8% yttria stabilized zirconia duplex (double layer) coatings. Micro- and crystal structure analysis support the findings and results are detailed and discussed
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