159 research outputs found

    Memories of quenches in operator mixing

    Full text link
    We work perturbatively with an interacting quantum field theory comprised of two distinct scalar fields. In this theory, we introduce a sudden quench of the mass of one of the scalars at time t0t_0. Also, the quartic interaction between the two scalars is turned on at time tint_{in}. These break time-translation invariance. In this setup we examine the effects of the relative ordering of t0t_0 and tint_{in} on composite operator mixing. We study how such operator mixing affect features of the scalar potential. We find that the late time effective potential can be sensitive enough to the quenches to trigger phase transitions.Comment: 27 pages, 12 figures and 1 tabl

    Time-resolved diffusion tomographic imaging in highly scattering turbid media

    Get PDF
    A method for imaging objects in highly scattering turbid media. According to one embodiment of the invention, the method involves using a plurality of intersecting source/detectors sets and time-resolving equipment to generate a plurality of time-resolved intensity curves for the diffusive component of light emergent from the medium. For each of the curves, the intensities at a plurality of times are then inputted into the following inverse reconstruction algorithm to form an image of the medium: X.sup.(k+1).spsp.T =?Y.sup.T W+X.sup.(k).spsp.T .LAMBDA.!?W.sup.T W+.LAMBDA.!.sup.-1 wherein W is a matrix relating output at detector position r.sub.d, at time t, to source at position r.sub.s, .LAMBDA. is a regularization matrix, chosen for convenience to be diagonal, but selected in a way related to the ratio of the noise, to fluctuations in the absorption (or diffusion) X.sub.j that we are trying to determine: .LAMBDA..sub.ij =.lambda..sub.j .delta..sub.ij with .lambda..sub.j =/ Here Y is the data collected at the detectors, and X.sup.k is the kth iterate toward the desired absoption information

    An approach for mistranslation removal from popular dataset for Indic MT Task

    Full text link
    The conversion of content from one language to another utilizing a computer system is known as Machine Translation (MT). Various techniques have come up to ensure effective translations that retain the contextual and lexical interpretation of the source language. End-to-end Neural Machine Translation (NMT) is a popular technique and it is now widely used in real-world MT systems. Massive amounts of parallel datasets (sentences in one language alongside translations in another) are required for MT systems. These datasets are crucial for an MT system to learn linguistic structures and patterns of both languages during the training phase. One such dataset is Samanantar, the largest publicly accessible parallel dataset for Indian languages (ILs). Since the corpus has been gathered from various sources, it contains many incorrect translations. Hence, the MT systems built using this dataset cannot perform to their usual potential. In this paper, we propose an algorithm to remove mistranslations from the training corpus and evaluate its performance and efficiency. Two Indic languages (ILs), namely, Hindi (HIN) and Odia (ODI) are chosen for the experiment. A baseline NMT system is built for these two ILs, and the effect of different dataset sizes is also investigated. The quality of the translations in the experiment is evaluated using standard metrics such as BLEU, METEOR, and RIBES. From the results, it is observed that removing the incorrect translation from the dataset makes the translation quality better. It is also noticed that, despite the fact that the ILs-English and English-ILs systems are trained using the same corpus, ILs-English works more effectively across all the evaluation metrics.Comment: 18 page

    Multilingual Neural Machine Translation System for Indic to Indic Languages

    Full text link
    This paper gives an Indic-to-Indic (IL-IL) MNMT baseline model for 11 ILs implemented on the Samanantar corpus and analyzed on the Flores-200 corpus. All the models are evaluated using the BLEU score. In addition, the languages are classified under three groups namely East Indo- Aryan (EI), Dravidian (DR), and West Indo-Aryan (WI). The effect of language relatedness on MNMT model efficiency is studied. Owing to the presence of large corpora from English (EN) to ILs, MNMT IL-IL models using EN as a pivot are also built and examined. To achieve this, English- Indic (EN-IL) models are also developed, with and without the usage of related languages. Results reveal that using related languages is beneficial for the WI group only, while it is detrimental for the EI group and shows an inconclusive effect on the DR group, but it is useful for EN-IL models. Thus, related language groups are used to develop pivot MNMT models. Furthermore, the IL corpora are transliterated from the corresponding scripts to a modified ITRANS script, and the best MNMT models from the previous approaches are built on the transliterated corpus. It is observed that the usage of pivot models greatly improves MNMT baselines with AS-TA achieving the minimum BLEU score and PA-HI achieving the maximum score. Among languages, AS, ML, and TA achieve the lowest BLEU score, whereas HI, PA, and GU perform the best. Transliteration also helps the models with few exceptions. The best increment of scores is observed in ML, TA, and BN and the worst average increment is observed in KN, HI, and PA, across all languages. The best model obtained is the PA-HI language pair trained on PAWI transliterated corpus which gives 24.29 BLEU.Comment: 38 pages, 2 figure

    Association of ABO blood group with severe falciparum malaria in adults: case control study and meta-analysis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Erythrocyte-associated antigenic polymorphisms or their absence have perhaps evolved in the human population to protect against malarial infection. Studies in various populations consistently demonstrate that blood group 'O' confers resistance against severe falciparum infection. In India, Odisha state has one of the highest incidences of <it>Plasmodium falciparum </it>infection and contributes to the highest number of deaths by falciparum malaria. This study aims to evaluate the relationship between ABO blood group and severe malaria in an adult population at the tertiary care centre in Odisha.</p> <p>Methods</p> <p>A total of 353 <it>P. falciparum </it>infected subjects and 174 healthy controls were screened for ABO blood group. Falciparum-infected individuals were categorized as severe malaria and uncomplicated malaria. Severe malaria was further clinically phenotyped into cerebral malaria, non-cerebral severe malaria and multi-organ dysfunction. A meta-analysis was performed to assess the role of ABO blood group in severe malaria.</p> <p>Results</p> <p>Frequency of blood group 'B' was significantly higher in patients with severe malaria compared to the uncomplicated cases (P < 0.0001; OR = 4.09) and healthy controls (P < 0.0001; OR = 2.79). Irrespective of the level of clinical severity, blood group 'B' was significantly associated with cerebral malaria (P < 0.0001; OR = 5.95), multi-organ dysfunction (P < 0.0001; OR = 4.81) and non-cerebral severe malaria patients (P = 0.001; OR = 3.02) compared to the uncomplicated category. Prevalence of 'O' group in uncomplicated malaria (P < 0.0001; OR = 2.81) and healthy controls (P = 0.0003; OR = 2.16) was significantly high compared to severe malaria. Meta-analysis of previous studies, including the current one, highlighted the protective nature of blood group 'O' to severe malaria (P = 0.01). On the other hand, carriers of blood group 'A' (P = 0.04) and 'AB' (P = 0.04) were susceptible to malaria severity.</p> <p>Conclusions</p> <p>Results of the current study indicate that blood group 'O' is associated with reduced and 'B' blood group with increased risk of development of severe malaria in Odisha, India. Meta-analysis also supports the protective nature of blood group 'O' from severe falciparum infection.</p

    Spin-crossover assisted metallization of few-layer FePS3_3 at 1.45 GPa

    Full text link
    Magnetic insulators in reduced dimension are the ideal model systems to study spin-crossover(SCO) induced cooperative behavior under pressure. Similar to the external perturbations like light illumination or temperature, external pressure may provide new pathway to accelerate giant lattice collapse,and subsequently Mott transition in van der Waals (vdW) materials with diminishing effect of the third dimension. Here, we investigate room-temperature layer-dependent SCO and insulator-metal transition in vdW magnet,FePS3, under high pressure using micro-Raman scattering.Experimentally obtained spectra, in agreement with the computed Raman modes, indicates evidence of IMT of FePS3 started off with a spin-state transition from a high (S=2) to low spin state (S=0) with a thickness dependent critical pressure (P_c) which reduces to 1.45 GPa in 3-layer flakes compared to 10.8 GPa for the bulk counterpart. Additionally, a broad Raman mode (P*) emerges between 310 cm^{-1} and 370 cm^{-1} at elevated pressure for three different thicknesses of FePS3 flakes (3-100 layers), also corroborated with computational results which suggests the pressure dependent decrease of metal-ligand bond distance(Fe-S) with lowering of magnetic moment in FePS3. Phenomenologically, our results in few-layer flakes with strong structural anisotropy which enhances the in-plane strain with applied pressure can be understood by adopting Hubbard model and considering the spectral-range (bandwidth W) as a function of layer numbers and pressure with a power-law scaling. Reduction of the critical pressure for phase transition in few-layer vdW magnets to 1-2 GPa marks the possibility of using nano-enclosure fit for use in device electronics where the pressure is induced due to interfacial adhesion, like in vdW heterostructure or molecules trapped between layers,and thereby,avoiding the conventional use of diamond anvil cell

    Brush Cytology on Pre-Malignant and Malignant Oral Lesions with Histopathological correlation

    Get PDF
    Introduction: Oral cancer is the sixth most common malignancy worldwide and accounts for 30% of all cancers in India, with 5-year survival rate, except when diagnosed in the early stages. Hence, early diagnosis of oral cancer is very much essential for the sake of the patient. However its burden on the economy for providinghealthcare is substantial and with the increasing incidence of oral cancer in developing countries like India and the other South-East-Asian countries, the role of screening methodologies for early detection of pre – cancerous and cancerous lesions of oral cavity are becoming more vital Methodology: An observational cross-sectional study conducted in the departments of Otolaryngology & head neck surgery in close association with department of Pathology in a tertiary based teaching institute in North Bengal, India, during April 2021 to March 2022. All the patients aged above 18 years, who visited the outpatient department of Otolaryngology & Head Neck Surgery, and admitted in the ward of the same, having oral lesions which are clinically suspected as pre- malignant and malignant lesions were included in this study. Results: The study population comprised of total 69 cases. Among them 47 cases (~68%) were malignantlesions, 13 (~19%) cases were pre-malignant and 9 (~13%) cases were diagnosed as benign lesions consideringHistopathology result. 30 (63.8%) out of 47 malignant cases show class-5 cytological grading in brush cytology smear, stained with Pap stain. 25.5% of the malignant cases were in class-4 and 10.6% cases were in class-3 whereas, in premalignant cases (n=13), 3 cases were in class-2 and 7 cases were in class-3 and 3 were in class-1. Maximum value of AgNOR counts for benign, pre malignant and malignant lesions were 3.54, 4.16, 7.28 respectively. Conclusion: The brush cytology with PAP grading and AgNOR analysis in clinically suspected    oral lesionscan be used as an early diagnostic tool for diagnosing oral squamous cell carcinoma especially for lower socio-economic status people who present with late stages

    Formation of Metallurgical Coke within Minutes through Coal Densification and Microwave Energy

    Get PDF
    This paper shows how feedstock densification gives rise to a step change in the time required to create a metallurgical grade coke using microwave energy. Five densified coking and non-coking coals were heated in a multi-mode microwave 2450 MHz cavity for varying treatment times (2-20 minutes) with a fixed power input (6 kW). Proximate analysis, intrinsic reactivity, coke reactivity, dielectric properties, and petrographic analysis of the coals and microwave produced lump cokes were compared to a commercial lump coke. Densifying the sample prior to microwave treatment enabled a dramatic acceleration of the coking process when combined with targeted high microwave energy densities. It was possible to form fused coke lump structures with only 2 minutes of microwave heating compared to 16-24 hours via conventional coking. Anisotropic coke morphologies (lenticular and circular) were formed from non-coking coal that are not possible with conventional coking and increasing treatment time improved overall coke reflectance. Three of the coals produced coke with equivalent coke reactivity index values of 20-30, which are in the acceptable range for blast furnaces. The study demonstrated that via this process, non-coking coals could potentially be used to produce high quality cokes, potentially expanding the raw material options for metallurgical coke production
    corecore