209 research outputs found
Deciphering the uniqueness of Mucoromycotina cell walls by combining biochemical and phylogenomic approaches
Most fungi from the Mucoromycotina lineage occur in ecosystems as saprobes, although some species are phytopathogens or may induce human mycosis. Mucoromycotina represent early diverging models that are most valuable for understanding fungal evolution. Here we reveal the uniqueness of the cell wall structure of the Mucoromycotina Rhizopus oryzae and Phycomyces blakesleeanus compared with the better characterized cell wall of the ascomycete Neurospora crassa. We have analysed the corresponding polysaccharide biosynthetic and modifying pathways, and highlight their evolutionary features and higher complexity in terms of gene copy numbers compared with species from other lineages. This work uncovers the presence in Mucoromycotina of abundant fucose-based polysaccharides similar to algal fucoidans. These unexpected polymers are associated with unusually low amounts of glucans and a higher proportion of chitin compared with N. crassa. The specific structural features are supported by the identification of genes potentially involved in the corresponding metabolic pathways. Phylogenomic analyses of genes encoding carbohydrate synthases, polysaccharide modifying enzymes and enzymes involved in nucleotide-sugar formation provide evidence for duplication events during evolution of cell wall metabolism in fungi. Altogether, the data highlight the specificity of Mucoromycotina cell walls and pave the way for a finer understanding of their metabolism.Hugo Mélida, Divya Sain, Jason E. Stajich, Vincent Bulon
Merchants of Virtue
Merchants of Virtue explores the question of what it meant to be Hindu in precolonial South Asia. Divya Cherian presents a fine-grained study of everyday life and local politics in the kingdom of Marwar in eighteenth-century western India to uncover how merchants enforced their caste ideals of vegetarianism and bodily austerity as universal markers of Hindu identity. Using legal strategies and alliances with elites, these merchants successfully remade the category of “Hindu,” setting it in contrast to “Untouchable” in a process that reconfigured Hinduism in caste terms. In a history pertinent to understanding India today, Cherian establishes the centrality of caste to the early-modern Hindu self and to its imagination of inadmissible others.
“A refreshingly different perspective on the history of caste and untouchability in India, enlarging the field of scholarship from its focus on the colonial era by telling us how precolonial configurations of power in the locality shaped the everyday experience of caste.” — GOPAL GURU, coauthor of The Cracked Mirror and Experience, Caste, and the Everyday Social
“This provocative and empirically rich study offers a plenitude of fascinating insights into aspects of western Indian history ca. 1800, from kingship and caste hierarchy to abortion and alcohol consumption. Particularly innovative is its focus on the critical role played by merchants in articulating social identities that became widespread in modern times.” — CYNTHIA TALBOT, author of The Last Hindu Emperor
“A pathbreaking book that explodes essentialist views of the construction of Hindu and Muslim identities in precolonial India. Divya Cherian provocatively argues that the category of ‘Hindu’ was the primary locus for a system of radical othering that excluded Untouchables (and Muslims as Untouchables) through mechanisms of state, law, and everyday life.” — CHRISTIAN LEE NOVETZKE, Professor of South Asian and Religious Studies, University of Washingto
Merchants of Virtue
Merchants of Virtue explores the question of what it meant to be Hindu in precolonial South Asia. Divya Cherian presents a fine-grained study of everyday life and local politics in the kingdom of Marwar in eighteenth-century western India to uncover how merchants enforced their caste ideals of vegetarianism and bodily austerity as universal markers of Hindu identity. Using legal strategies and alliances with elites, these merchants successfully remade the category of “Hindu,” setting it in contrast to “Untouchable” in a process that reconfigured Hinduism in caste terms. In a history pertinent to understanding India today, Cherian establishes the centrality of caste to the early-modern Hindu self and to its imagination of inadmissible others.
“A refreshingly different perspective on the history of caste and untouchability in India, enlarging the field of scholarship from its focus on the colonial era by telling us how precolonial configurations of power in the locality shaped the everyday experience of caste.” — GOPAL GURU, coauthor of The Cracked Mirror and Experience, Caste, and the Everyday Social
“This provocative and empirically rich study offers a plenitude of fascinating insights into aspects of western Indian history ca. 1800, from kingship and caste hierarchy to abortion and alcohol consumption. Particularly innovative is its focus on the critical role played by merchants in articulating social identities that became widespread in modern times.” — CYNTHIA TALBOT, author of The Last Hindu Emperor
“A pathbreaking book that explodes essentialist views of the construction of Hindu and Muslim identities in precolonial India. Divya Cherian provocatively argues that the category of ‘Hindu’ was the primary locus for a system of radical othering that excluded Untouchables (and Muslims as Untouchables) through mechanisms of state, law, and everyday life.” — CHRISTIAN LEE NOVETZKE, Professor of South Asian and Religious Studies, University of Washingto
Improved collision detection in StarLogo Nova
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (page 65).StarLogo Nova is blocks-based educational software that allows students to write and play their own 3D games online. It is the online version of StarLogo TNG. This thesis explores the problem of needing more accurate collision detection in StarLogo Nova while maintaining reasonable performance. Three new collision detection systems for StarLogo Nova are developed and evaluated. Compared to the spheres used to perform collision checks in the current system, the first new system, called the TightestFitCollider, introduces a variety of bounding spheres, bounding boxes, and bounding capsules as bounding structures that may fit the models in StarLogo Nova more closely. The second system, called the HierarchicalCollider, uses hierarchies of bounding boxes to perform even more precise collision detection than the TightestFitCollider. Finally, the third system combines the first two systems, so that the advantages of each can be used as appropriate. The three systems are evaluated for their accuracy and performance within the StarLogo Nova framework.by Divya Bajekal.M. Eng
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Discovery of Fungal Cell Wall Components Using Evolutionary and Functional Genomics
Understanding the various processes/pathways necessary for the biogenesis and maintenance of the cell wall is of immense value as that knowledge can be used for developing antifungals. This dissertation attempts to make a significant contribution in furthering our understanding of the fungal cell wall and its various components. I have identified and characterized genes involved in cell wall growth and maintenance in the model fungus Neurospora crassa by employing a functional screen. I utilized comparative genomics approaches to reconstruct the evolutionary history of cell wall polysaccharides chitin and glucan in the early diverging fungal clades- Microsporidia, Cryptomycota, Chytridiomycota, Blastocladiomycota and Mucormycota. Using a combination of biochemical and comparative genomics I attempted to compare and contrast the cell wall composition of the early diverging fungal clades Chytridiomycota, Blastocladiomycota and Mucormycota to the recently diverged Dikarya fungi. The research presented in this dissertation should lead to the characterization of novel cell wall genes in the filamentous fungi that eventually will lead to development of better drug targets for designing anti-fungal drugs. Also it will lead to better understanding of the cell walls of evolutionarily distinct fungi, which will enable us to combat the pathogenic fungi in a more powerful way. In terms of broader impact this research will be an important contribution to the knowledge of cell wall in the fungal community
Antiepileptic drugs for the primary and secondary prevention of seizures after subarachnoid haemorrhage
Background: subarachnoid haemorrhage may result in seizures both acutely and in the longer term. The use of antiepileptic drugs (AEDs) in the primary and secondary prevention of seizures after subarachnoid haemorrhage is uncertain, and there is currently no consensus on treatment.Objectives: to assess the effects of AEDs for the primary and secondary prevention of seizures after subarachnoid haemorrhage.Search methods: we searched the Cochrane Epilepsy Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 1) in The Cochrane Library, and MEDLINE (1946 to 12th March 2013). We checked the reference lists of articles retrieved from these searches.Selection criteria: we considered all randomised and quasi-randomised controlled trials in which patients were assigned to a treatment (one or more AEDs) or placebo.Data collection and analysis: two review authors (RM and JK) independently screened and assessed the methodological quality of the studies. If studies were included, one author extracted the data and the other checked it.Main results: no relevant studies were found.Authors' conclusions: there was no evidence to support or refute the use of antiepileptic drugs for the primary or secondary prevention of seizures related to subarachnoid haemorrhage. Well-designed randomised controlled trials are urgently needed to guide clinical practice
Magnetic resonance imaging of the cerebral metabolic rate of oxygen (CMRO₂)
Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2010.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 120-128).Oxygen consumption is an essential process of the functioning brain. The rate at which the brain consumes oxygen is known as the cerebral metabolic rate of oxygen (CMRO₂). CMRO₂ is intimately related to brain health and function, and will change in settings of disease and functional activation. Accurate CMRO₂ measurement will enable detailed investigation of neuropathology and facilitate our understanding of the brain's underlying functional architecture. Despite the importance of CMRO₂ in both clinical and basic neuroscience settings, a robust CMRO₂ mapping technique amenable to functional and clinical MRI has not been established. To address this issue, a novel method called QUantitative Imaging of eXtraction of Oxygen and TIssue Consumption, or QUIXOTIC, is introduced. The key innovation in QUIXOTIC is the use of velocity-selective spin labeling to isolate MR signal exclusively from post-capillary venular blood on a voxel-by-voxel basis. This isolated signal can be related to venular oxygen saturation, oxygen extraction fraction, and ultimately CMRO₂. This thesis first explores fundamental theory behind the QUIXOTIC technique, including design of a novel MRI pulse sequence, explanation of the principal sequence parameters, and results from initial human experiences. A human trial follows, in which QUIXOTIC is used to measure cortical gray matter CMRO₂ in ten healthy volunteers.(cont.) QUIXOTIC-measured CMRO₂ is found to be within the expected physiological range and is comparable to values reported by other techniques. QUIXOTIC is then applied to evaluate CMRO₂ response to carbon-dioxide-induced hypercapnia in awake humans. In this study, CMRO₂ is observed to decrease in response to mild hypercapnia. Finally, pilot studies that show feasibility of QUIXOTIC-based functional MRI (fMRI) and so-called "turbo" QUIXOTIC are presented and discussed.by Divya Sanam Bolar.Ph.D
European Narratives on Remote Working and Coworking During the COVID-19 Pandemic
This open access book offers a multidisciplinary and comprehensive perspective regarding the immediate and long-term effects of the Covid-19 pandemic on coworking spaces in the European Region. The current pandemic has imposed several effects on work and spaces for work. Some are immediate effects and will last for a short time (such as the closing down of the space), some will last longer (namely, the reorganisation of the space to meet the physical distancing), and some will stay for a long time (remote working and hybrid working). Although the literature on coworking spaces and the effects of the pandemic is growing fast, empirical studies are yet limited. Within this context, this book seeks a twofold aim: (i) to contribute to the fast-growing literature on coworking space and their effects at different scales; (ii) to present a multidisciplinary perspective about the effects of the yet-lasting Corona-pandemic effects on the patterns of remote working and consequently on coworking spaces, as the most diffused form of new working spaces.History, Form & Aesthetic
Clinical trend discovery and analysis of Taiwanese health insurance claims data
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 61-62).Data-driven analysis can improve our understanding of medicine, and data from electronic health records and labs has been used successfully in predictive tasks. Less advanced analysis has been done on health insurance claims data, which can be rich and more structured but large in scale. Taiwan has had nationalized health insurance for twenty years; its National Health Research Institute Database (NHIRD) contains records of insurance claims, including medications, prescriptions, and treatment costs for both inpatient and outpatient visits, spanning sixteen years and a million patients. The NHIRD enables longitudinal studies of a patient's medical progression as well as aggregation and generalization to population-level insights. We conducted preliminary exploration of data trends in aggregate, such as diagnosis code frequency and average treatment cost over time. An infrastructure to perform large-scale queries and handle results was required to effectively use the NHIRD for research applications. After indexing database tables to improve query performance, we created a pipeline in Python to connect to and query the database, analyze data for hypothesis discovery and hypothesis testing, convert Taiwanese codes to international standards, and produce plots and graphs. This pipeline was used to examine drug side effects and comorbidities observed across a population, accounting for demographic variables. We also studied patient-specific longitudinal matrices of medical events, which were highly sparse. We attempted quantitative imputation methods to densify these matrices, but because the data was binary (indicating the presence of an event at a given time), categorical, and irregular, advanced imputation offered limited benefit. Nevertheless, we discovered interesting patterns in cohorts of diabetes patients treated with various classes of drugs. This information can be exploited in computational phenotyping and other learning methods, and combined with other data sources it could increase accuracy of clinical predictive tasks.by Divya P. Pillai.M. Eng
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