323 research outputs found
D-branes, RR-fields and duality on noncommutative manifolds
No full textWe develop some of the ingredients needed for string theory on noncommutative spacetimes, proposing an axiomatic formulation of T-duality as well as establishing a very general formula for D-brane charges. This formula is closely related to a noncom4 mutative Grothendieck-Riemann-Roch theorem that is proved here. Our approach relies on a very general form of Poincaré duality, which is studied here in detail. Among the technical tools employed are calculations with iterated products in bivariant K-theory and cyclic theory, which are simplified using a novel diagram calculus reminiscent of Feynman diagrams
Novel modulators of non-selective and selective autophagy
No full textPå samme måte som søppel dannes fra vårt daglige forbruk, produserer cellene i kroppen vår avfallsprodukter som transporteres til cellens resykleringsstasjon (lysosomet), hvor det brytes ned og gjenvinnes. Dette skjer via en prosess kalt autofagi, som involverer oppsamling av kargo/søppel i en vesikkel (et autofagosom) som smelter sammen med lysosomet. Autofagi oppreguleres ved stress, f.eks sult, men et basalt nivå av autofagi er viktig i alle celler for å beskytte mot sykdommer som kreft og nevrodegenerering.
Dannelsen av autofagosomer er vist å involvere en rekke proteinkomplekser og lipider, men de eksakte mekanismene involvert i regulering av autofagi er ikke kjent. I denne avhandlingen har Benan John Mathai og medarbeidere vist at proteinet HS1BP3 er en negativ regulator av autofagi. De fant at HS1BP3 inhiberer autofagi ved å hemme aktiviteten til det lipid-modifiserende enzymet PLD1, som igjen er viktig for å lage lipidet fosfatidsyre (PA) som er vist å være viktig for autofagi. Mathai fant at den regulatoriske rollen til HS1BP3 i autofagi er konservert i zebrafisk larver som uttrykker en fluoreserende markør for autofagi (LC3).
Selektiv nedbryting av spesialavfall (som dysfunksjonelle mitokondrier eller protein aggregater) ved autofagi krever spesielle autofagi-reseptorer (f.eks p62) som binder kargo. Benan John Mathai og medarbeidere har identifisert et «eat-me signal» på mitokondrier som gjenkjennes av slike autofagi reseptorer. Ved depolarisering av mitokondriene akkumulerer matriksproteinene NIPSNAP1 og NIPSNAP2 på overflaten av mitokondriene hvor de binder autofagireseptorer, som fører til nedbrytning av de ødelagte mitokondriene (mitofagi). NIPSNAP1/2-mediert mitofagi er avhengig av proteinene PINK1 og PARKIN, som begge er assosiert med Parkinsons sykdom. Mathai fant at zebrafisk larver som mangler Nipsnap1 har økt oksidativt stress, redusert nivå av dopaminerge nevroner og redusert bevegelse.
Dette doktorgradsarbeidet er et viktig bidrag til vår forståelse av de molekylære mekanismene involvert i regulering og dannelse av autofagosomer og gir innsikt i betydningen av disse prosessene i å hindre utvikling av sykdom
Evolution and future trends in battle injuries to the CNS
No full textDespite advances in personal protection, brain and spinal injuries amongst combatants pose significant management challenges. Battle field medical care has evolved over the year. In this article we discuss evolutions of military medicine, study current protocols and outcomes and discuss future perspectives. Mention is also made of some original work by the author
Projective Dirac Operators, Twisted K-Theory, and Local Index Formula
No full textWe construct a canonical noncommutative spectral triple for every oriented closed Riemannian manifold, which represents the fundamental class in the twisted K-homology of the manifold. This so-called "projective spectral triple" is Morita equivalent to the well-known commutative spin spectral triple provided that the manifold is spin-c. We give an explicit local formula for the twisted Chern character for K-theories twisted with torsion classes, and with this formula we show that the twisted Chern character of the projective spectral triple is identical to the Poincare dual of the A-hat genus of the manifold
The neuroscience of management
No full textBehaviour is wired into and a product of our brain's circuitry. In this paper we discuss the neuroanatomical templates of education, training and decision making. This awareness is important and could influence the way we train young minds, to take over the mantle of tomorrow's leadership.
The bulk of our brain's volume is in two cerebral hemispheres, constituted by the frontal, parietal and occipital lobes. These hemispheres (the neocortex) act as centres of information processing and storage. Life sustenance and locomotion are controlled by the brainstem and cerebellum. The 60 billion neurons we are born with and their connections or synapses constitute the brain's ‘hardware'. While the software for life sustenance is loaded at birth, the information storage zones are blank pages.
The dominant mode of information input is initially visual. Speech acquisition facilitates verbal dominance. Verbal information is initially stored in the hippocampus. Hippocampi are ‘sea horse’ shaped structures located in the medial temporal lobes which act as the ‘desktop’ for easy storage and retrieval of information. Hippocampal relations with the lateral ventricle (regenerative potential), the Meyers loop of the visual pathway and the amygdala (rage centre) provide twists in the tale.
Information from the hippocampal desktop is projected in waves of bulk information transfer called ‘thalamocortical’ spindles to the neocortex. Fresh inputs modify this information by creating new synapses in a process called neosynaptogenesis. Retrieval and reinforcement of information circuits is by task performance and job training.
A silent quorum of neurons (Around 70%) is the repository of our personalities and character and the seat of our souls. Decision making involves the information template. Mature decisions invokes these personal qualities (which too a r e partially acquired and hence modifiable) modulating ethical and humane decisions. Decisions made in anger may bypass the information template altogether in a n ‘amygdala hijack'.
The capability of the human brain to process the varying levels of information, knowledge and wisdom anagrams bestows upon it a potential for ‘Fuzzy Logic’ and the ability to create ‘Blue Ocean’ strategies
Stenaelurillus sarojinae Caleb & Mathai 2014
No full text<i>Stenaelurillus sarojinae</i> Caleb & Mathai, 2014 <p>Figs. 28–51, 115.</p> <p> <i>Stenaelurillus sarojinae</i> Caleb & Mathai, 2014: 64, f. 24–30. Holotype in Zoological Survey of India, Chennai, India; not examined.</p> <p> <i>Stenaelurillus sarojinae</i> Caleb, Mungkung & Mathai, 2015: 12, f. 57–61, 63–81. Male in NCBS; not examined.</p> <p> <b>Material examined.</b> 11 <i>♂♂</i> & 3 <i>♀♀</i>. INDIA: Karnataka: Mysuru: south of Mysuru, grassland, 12.215 to 12.216 °N 76.625 °E, elev. 763 m asl, 4 July 2019, coll. K. Marathe, W. Maddison, S. Javagal, & Abhijith APC, WPM#19-104 and WPM#19-106.</p> <p> <b>Geographic variation.</b> The Mysuru population differs in several respects from that at the type locality in Kadapa, about 400 km NE of Mysuru (Caleb & Mathai 2014; Caleb <i>et al.</i> 2015). Mysuru males have the dorsum of the abdomen a matte grey, made from a mix of bluish-grey and brown scales, with the balance shifting to dark brown in the posterior quarter. The four major muscle attachment points appear as dark spots. In contrast, Kadapa males have the posterior two-thirds of the abdomen covered uniformly with glossy dark metallic blue scales. Despite this striking difference in markings, the palpal structure is similar enough between these two populations that we are considering them geographic variants. <i>Females</i> of the Mysuru population are rusty coloured, especially the carapace and anterior end of the abdomen, and the white spots on the abdomen are rounder; in contrast, the Kadapa population appear to be brown coloured, and the white areas on the abdomen broader extending horizontally.</p> <p> <b>Diagnosis.</b> Among the Indian <i>Stenaelurillus</i> with fringed-abdomen, <i>S. sarojinae</i> males uniquely have an embolic process, a bluish-grey or glossy metallic dark blue abdomen, and lateral abdominal fringes that are restricted to the posterior half. <i>S</i>. <i>sarojinae</i> females are similar to others in the groups in having a general drab appearance but pronounced longitudinal bands on the carapace, and a central chevron on the abdomen flanked with white spots medially separates females of this species from others.</p> <p> <b>Description.</b> <i>Male</i> (based on specimen IBC-BP312/ DDKM21.009). Measurements: Carapace 1.63 long, 1.16 wide. Abdomen length 1.65, width 1.2. Leg lengths: I—3.2 (1.1, 0.5, 0.8, 0.5, 0.3); II—3.4 (1.2, 0.6, 0.8, 0.6, 0.3); III—5.6 (1.8, 0.4, 1.6, 1.3, 0.5); IV—4.5 (1.3, 0.5, 1.1, 1.0, 0.6). Leg formula: III-IV-II-I. <i>Carapace</i> narrow, about as wide as abdomen. Anteriorly black, covered with black scales and hairs, and rust coloured medially. Two yellowishwhite longitudinal stripes running down behind PLEs. Two yellowish-white bands on lateral margins. <i>Clypeus</i> yellowish, sparsely covered with white hairs. <i>Chelicerae</i> vertical, narrow, yellowish-brown, sparsely covered with white hairs. <i>Palp</i> (Figs. 28, 29, 32, 33): Cymbium yellowish with some black. Embolus accompanied with apophysis (appears as a 2-prong fork). Tegular process round. Femur with a distally located ventral process. <i>Legs</i> robust, yellowish orange, except tarsus and metatarsus I black, and tibia I black below and dusky above. Legs covered with cream to orange scales, except first leg, with black setae under patella and more distally. <i>Abdomen</i> with black spot anteriorly with somewhat long black setae, rest covered with greyish-blue setae dorsally; four somewhat black spots medially located. Posterior edge fringed with black and yellowish setae. Spinnerets black.</p> <p> <i>Female</i> (based on specimen IBC-BP313/ AS 19.6591). Measurements: Carapace 1.38 long, 1.04 wide.Abdomen length 1.97, width 0.97. Leg lengths: I—3.2 (1.2, 0.6, 0.6, 0.4, 0.3); II—3.4 (1.3, 0.6, 0.6, 0.6, 0.4); III—6.2 (1.9, 0.9, 1.4, 1.3, 0.6); IV—5.2 (1.4, 0.6, 1.3, 1.3, 0.7). Leg formula: III-IV-II-I. <i>Carapace</i> slightly narrower than abdomen.Anteriorly dark brown, covered with black scales and hairs, white scales along PMEs and PLEs, remaining dominantly reddish-brown covered with black scales. Two white longitudinal stripes running down behind PLEs. Two white bands on lateral margins. <i>Clypeus</i> reddish brown, sparsely covered with white setae. <i>Chelicerae</i> as in males. <i>Legs</i> robust, yellowish orange, sparsely covered with black, orange, and white scales. <i>Abdomen</i> dominantly brownish black with medial longitudinal yellowish-brown chevron flanked by two white spots medially. Yellowishwhite band on sides encompasses central brownish-black area. Spinnerets brownish black with white tips. <i>Epigyne</i> (Figs. 30, 31, 34, 35): What we interpret as the ECP is small and circular, hidden in a sclerotized fold projecting over the epigastric furrow. Copulatory openings inverted U shaped, located anterior to ECP.</p> <p> <b>Natural history.</b> <i>Stenaelurillus sarojinae</i> was locally common in open grassland, rarely in shaded areas, often actively moving amid grass tufts, on the dirt and on rocks. We (KM & Abhijith APC) noticed a male on a pebble lifting and shaking its fringed blue abdomen in a pose reminiscent of the mating displays of <i>Maratus</i> species (Girard <i>et al.</i> 2011) and <i>Habronattus</i> species (e.g., Elias <i>et al</i>. 2012), raising the possibility that these and other <i>Stenaelurillus</i> may have complex courtship worthy of further investigation. The male was displaying, surprisingly, simultaneously to at least 5 females standing side by side, all of which were collected subsequently and found to be immature.</p>Published as part of <i>Marathe, Kiran, Sanap, Rajesh, Joglekar, Anuradha, Caleb, John T. D. & Maddison, Wayne P., 2022, Three new and notes on two other jumping spider species of the genus Stenaelurillus Simon, 1886 (Salticidae: Aelurillina) from the Deccan Plateau, India, pp. 1-19 in Zootaxa 5125 (1)</i> on pages 6-8, DOI: 10.11646/zootaxa.5125.1.1, <a href="http://zenodo.org/record/6420417">http://zenodo.org/record/6420417</a>
Post traumatic epilepsy : An analysis of interesting spectrum of cases at a tertiary care neurosurgical centre
No full textObjective: We present some unusual cases of post traumatic epilepsy managed in the high care unit of a tertiary care neurosurgical centre. They were thouroughly evaluated to determine the cause of post traumatic epilepsy. The pathogenesis of Post Traumatic Epilepsy which provides insights into neural injury, rewiring and regeneration paradigms is discussed.
Materials and methods: Six male patients aged 19-35 years who suffered head injury and suffered post traumatic epilepsy were enrolled & observed during their hospital stay. They underwent neuroimaging and EEG monitoring to rule out other causes of epilepsy. Two patients were lost due to death.
Results: All patients suffered Parenchymal injury. Seizure spectrum included not only motor but also autonomic manifestations. The Autonomic manifestations were more resistant to antiseizure medication but responded to SOS treatment Seizure threshold is probably reduced during episodes of wound site infection, URTI or urinary infections
Conclusion: The mechanisms causing seizures in TBI patients are incompletely understood. In our set of patients, the common thread that runs through these cases is that they all had severe brain insults followed by post traumatic epilepsy. Cortical lesions seem important in the genesis of the epileptic activity, and early seizures are likely to have a different pathogenesis than late seizures
Rationalising health care in india : Challenges & strategies
No full textAn overview of health care delivery in India is essential, if we are to plan and to improve health care delivery and the indices of health in the coming decades. The health sector in India is a mix of private and government services. While some health care indices appear dismal, several others, including life expectancy are heartening. A balance between regulation and free enterprise is possibly the best option. In this paper we provide a glimpse of health and health related statistics & a n overview of the public health care delivery systems. In the end, we offer suggestion on rationalisation of health care delivery to provide maximum services for the majority of our population within the budget of an optimal health care system outla
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