194 research outputs found

    Ordering through learning in two-dimensional Ising spins

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    We study two-dimensional Ising spins, evolving through reinforcement learning using their state, action, and reward. The state of a spin is defined as whether it is in the majority or minority with its nearest neighbours. The spin updates its state using an {\epsilon}-greedy algorithm. The parameter {\epsilon} plays the role equivalent to the temperature in the Ising model. We find a phase transition from long-ranged ordered to a disordered state as we tune {\epsilon} from small to large values. In analogy with the phase transition in the Ising model, we calculate the critical {\epsilon} and the three critical exponents {\beta}, {\gamma}, {\nu} of magnetization, susceptibility, and correlation length, respectively. A hyper-scaling relation d{\nu} = 2{\beta} + {\gamma} is obtained between the three exponents. The system is studied for different learning rates. The exponents approach the exact values for two-dimensional Ising model for lower learning rates

    UATTA-ENS: Uncertainty Aware Test Time Augmented Ensemble for PIRC Diabetic Retinopathy Detection

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    Deep Ensemble Convolutional Neural Networks has become a methodology of choice for analyzing medical images with a diagnostic performance comparable to a physician, including the diagnosis of Diabetic Retinopathy. However, commonly used techniques are deterministic and are therefore unable to provide any estimate of predictive uncertainty. Quantifying model uncertainty is crucial for reducing the risk of misdiagnosis. A reliable architecture should be well-calibrated to avoid over-confident predictions. To address this, we propose a UATTA-ENS: Uncertainty-Aware Test-Time Augmented Ensemble Technique for 5 Class PIRC Diabetic Retinopathy Classification to produce reliable and well-calibrated predictions.Comment: To Appear at Medical Imaging meets NeurIPS Workshop 202

    Marsupialization Catheter

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    A significant issue among oral and maxillofacial surgeons is the treatment of cysts within the jaw. Cysts develop at random and in most cases asymptomatically. Therefore, they may reach enormous sizes before being diagnosed. Large cysts can cause severe damage to teeth and the surrounding bone. Doctors treat small cysts by surgically removing them. However, this approach is not ideal for large cysts due to the risk of surgical complications, the high expenses incurred, and the fact that it is often undesired by the patient. Current treatments include surgically opening the cyst and either suturing the tissue open or placing a small plug in the opening. However, these treatments lack key elements such as retentiveness, biocompatibility, and comfort. The objective of this project is the treatment of large, fluid-filled, benign cysts that form in the human jaw or other facial bones through creation of a tube-like structure that will serve as a conduit between the cyst and the inside of the mouth in order to equalize pressure between the two spaces and allow healing to occur, as currently there is no device which is made specifically for the purpose of keeping cyst drainage holes open. The final design is a single cylindrical tube made from PLA with increased porosity on the outside and increased density on the inside, a widened rim at the end that will remain in the oral cavity, and insertable tabs that will pop open at the end of the device that will be inside the bone. These tabs will secure the device in place and prevent it from being dislodged.https://scholarscompass.vcu.edu/capstone/1067/thumbnail.jp

    A health care labyrinth: perspectives of caregivers on the journey to accessing timely cancer diagnosis and treatment for children in India.

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    BACKGROUND: Cure rates for children with cancer in India lag behind that of high-income countries. Various disease, treatment and socio-economic related factors contribute to this gap including barriers in timely access of diagnostic and therapeutic care. This study investigated barriers to accessing care from symptom onset to beginning of treatment, from perspectives of caregivers of children with cancer in India. METHODS: Semi-structured in-depth interviews were conducted with caregivers of children (< 18 years) diagnosed with cancer in seven tertiary care hospitals across New Delhi and Hyderabad. Purposive sampling to saturation was used to ensure adequate representation of the child's gender, age, cancer type, geographical location and socioeconomic status. Interviews were audio recorded after obtaining informed consent. Thematic content analysis was conducted and organised using NVivo 11. RESULTS: Thirty-nine caregivers were interviewed, where three key themes emerged from the narratives: time intervals to definitive diagnosis and treatment, the importance of social supportive care and the overall accumulative impacts of the journey. There were two phases encapsulating the experiences of the family: referral pathways taken to reach the hospital and after reaching the hospital. Most caregivers, especially those from distant geographical areas had variable and inconsistent referral pathways partly due to poor availability of specialist doctors and diagnostic facilities outside major cities, influence from family or friends, and long travel times. Upon reaching the hospital, families mostly from public hospitals faced challenges navigating the hospital facilities, finding accommodation, and comprehending the diagnosis and treatment pathway. Throughout both phases, financial constraint was a recurring issue amongst low-income families. The caregiver's knowledge and awareness of the disease and health system, religious and social factors were also common barriers. CONCLUSION: This qualitative study highlights and explores some of the barriers to childhood cancer care in India. Our findings show that referral pathways are intrinsically linked to the treatment experience and there should be better recognition of the financial and emotional challenges faced by the family that occur prior to definitive diagnosis and treatment. This information would help inform various stakeholders and contribute to improved interventions addressing these barriers

    A comparative analysis of the findings of postmortem computed tomography scan and traditional autopsy in traumatic deaths: Is technology mutually complementing or exclusive?

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    Background: Postmortem examination is indispensable to ascertain the cause of an unnatural death and as such is mandatory by the law. From ages, traditional autopsy (TA) has proved its worth in establishing the cause of death in the deceased despite some inherent difficulties and challenges and has enjoyed an insurmountable status. The increasing use of application of the modern-day radiology for postmortem examination has however opened a new arena overcoming some of the difficulties of the TA. There are conflicting reports in the published literature regarding superiority of one modality of the postmortem over the other. Objective: The objective of this study was to compare the findings of postmortem computed tomography (CT) scan and TA in the victims of traumatic deaths and to analyze whether postmortem CT can be used to replace TA. Materials and Methods: All patients with a history of trauma that were declared brought dead on arrival in the emergency department were subjected to full-body CT scan. An experienced radiologist reported the findings of CT scan. Subsequently, a forensic expert subjected the patients to TA. The physician who performed autopsy was blinded to the findings of CT scan and vice versa. An individual who was not part of the radiology or forensic team then entered the findings of CT scan and autopsy in a predesigned Pro forma. An unbiased assessor finally compared the findings of the two modalities and analyzed the results. McNemar's test was used to ascertain the level of significance between the findings reported by these two modalities considering P = 0.05 as statistically significant. The agreement or disagreement on cause of death reported by these two modalities was also assessed. Results: About 95 of the deceased were males. The mean age of the corpses was 35 years (range 1667 years). CT was found superior in picking up most of the bony injuries, air-containing lesions, hemothorax, and hemoperitoneum. However, autopsy was found more sensitive for soft-tissue and solid visceral injuries. Both modalities were equally helpful in identifying extremity fractures. Statistically significant agreement (>95) on cause of death by both modalities was not achieved in any patient of trauma. Conclusion: Postmortem CT scan is promising in reporting injuries in traumatic deaths and can significantly complement the conventional autopsy. However, at present, it cannot be considered as a replacement for TA

    Comprehensive preclinical evaluation of human-derived anti-poly-GA antibodies in cellular and animal models of C9ORF72 disease

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    Hexanucleotide G4C2 repeat expansions in the C9ORF72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Dipeptide repeat proteins (DPRs) generated by translation of repeat-containing RNAs show toxic effects in vivo as well as in vitro and are key targets for therapeutic intervention. We generated human antibodies that bind DPRs with high affinity and specificity. Anti-GA antibodies engaged extra- and intracellular poly-GA and reduced aggregate formation in a poly-GA over-expressing human cell line. However, antibody treatment in human neuronal cultures synthesizing exogenous poly-GA resulted in the formation of large extracellular immune complexes and did not affect accumulation of intracellular poly-GA aggregates. Treatment with antibodies was also shown to directly alter the morphological and biochemical properties of poly-GA and to shift poly-GA/antibody complexes to more rapidly sedimenting ones. These alterations were not observed with poly-GP and have important implications for accurate measurement of poly-GA levels including the need to evaluate all centrifugation fractions and disrupt the interaction between treatment antibodies and poly-GA by denaturation. Targeting poly-GA and poly-GP in two mouse models expressing G4C2 repeats by systemic antibody delivery for up to 16 months was well-tolerated and led to measurable brain penetration of antibodies. Long term treatment with anti-GA antibodies produced improvement in an open field movement test in aged C9ORF72450 mice. However, chronic administration of anti-GA antibodies in AAV-(G4C2)149 mice was associated with increased levels of poly-GA detected by immunoassay and did not significantly reduce poly-GA aggregates or alleviate disease progression in this model. Significance Immunotherapy has been proposed for neurodegenerative disorders including Alzheimer’s or Parkinson’s diseases. Recent reports using antibodies against poly-GA or active immunization suggested similar immunotherapy in ALS/FTD caused by repeat expansion in the C9ORF72 gene (1, 2). Here, we systematically characterized human antibodies against multiple DPR species and tested the biological effects of antibodies targeting poly-GA in different cellular and mouse models. Target engagement was shown in three independent cellular models. Anti-GA antibodies reduced the number of intracellular poly-GA aggregates in human T98G cells but not in cultured human neurons. Whereas chronic anti-GA treatment in BAC C9ORF72450 mice did not impact poly-GA levels and modestly improved one behavioral phenotype, poly-GA levels detected by immunoassays were increased and disease progression was unaltered in AAV-(G4C2)149 mice

    Betelvine (Piper betle L.): A comprehensive insight into its ethnopharmacology, phytochemistry, and pharmacological, biomedical and therapeutic attributes

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    Piper betle L. (synonym: Piper betel Blanco), or betel vine, an economically and medicinally important cash crop, belongs to the family Piperaceae, often known as the green gold. The plant can be found all over the world and is cultivatedprimarily in South East Asian countries for its beautiful glossy heart-shaped leaves, which are chewed or consumed as betelquidand widely used in Chinese and Indian folk medicine, as carminative, stimulant,astringent, against parasitic worms, conjunctivitis, rheumatism, wound, etc., andis also used for religious purposes. Hydroxychavicol is the most important bioactive compound among the wide range of phytoconstituents found in essential oil and extracts. The pharmacological attributes of P. betle are antiproliferation, anticancer, neuropharmacological, analgesic, antioxidant, antiulcerogenic, hepatoprotective, antifertility, antibacterial, antifungal and many more. Immense attention has been paid to nanoformulations and their applications. The application of P. betle did not show cytotoxicity in preclinical experiments, suggesting that it could serve as a promising therapeutic candidate for different diseases. The present review comprehensively summarizes the botanical description, geographical distribution, economic value and cultivation, ethnobotanical uses, preclinical pharmacological properties with insights of toxicological, clinical efficacy, and safety of P. betle. The findings suggest that P. betle represents an orally active and safe natural agent that exhibits great therapeutic potential for managing various human medical conditions. However, further research is needed to elucidate its underlying molecular mechanisms of action, clinical aspects, structure–activity relationships, bioavailability and synergistic interactions with other drugs.This research was funded by projects APOGEO (Cooperation Program INTERREG-MAC 2014–2020, with European Funds for Regional Development-FEDER, ‘Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI) del Gobierno de Canarias’ (project ProID2020010134), and CajaCanarias (project 2019SP43).Peer reviewe

    The Crisis in Metaphors

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    This paper attempts to recover some elisions of Indigenous thought in contemporary literary readings of the non-human, especially those from the Global South. I will focus on Indigenous conceptions of what I term ‘climate vocabularies’ in order to re-read Indigenous articulations of the non-human that have signalled climate as a ‘common organising concept’ (Todd 8) and provided early concerns on anthropogenic impact that has resulted in the current form of the climate emergency. This paper will trace an abridged climate history of eastern India by examining protest songs on mineral extraction, particularly focusing on the recent movements in Kashipur and Niyamgiri. I frame the call for jal, jangal, jameen (water, forests, land) as climate vocabulary because increased human exploitation of the past few centuries on these elements have heavily altered micro-climates of east-Indian geographies. Given Adivasi (Indian Indigenous) communities have been residents of these regions, the call for protection and ownership of jal, jangal, jameen in its many local articulations and transmutations has acquired essential presence across Adivasi movements in South Asia. Here, the materiality of the elements of water, land and forests in its literal sense is paramount. This paper will discuss the poetry of Kondh leader from Kashipur Bhagban Majhi, and Dongria Kondh poet Dambu Praska, to examine the ways in which they present changes in local ecologies brought about by mining as evidentiaries to communicate climate breakdown
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