4,211 research outputs found
Morphological Image Analysis of Quantum Motion in Billiards
Morphological image analysis is applied to the time evolution of the
probability distribution of a quantum particle moving in two and
three-dimensional billiards. It is shown that the time-averaged Euler
characteristic of the probability density provides a well defined quantity to
distinguish between classically integrable and non-integrable billiards. In
three dimensions the time-averaged mean breadth of the probability density may
also be used for this purpose.Comment: Major revision. Changes include a more detailed discussion of the
theory and results for 3 dimensions. Now: 10 pages, 9 figures (some are
colored), 3 table
Globalizing queer? AIDS, homophobia and the politics of sexual identity in India
Queerness is now global. Many emerging economies of the global South are experiencing queer mobilization and sexual identity politics raising fundamental questions of citizenship and human rights on the one hand; and discourses of nationalism, cultural identity, imperialism, tradition and family-values on the other. While some researchers argue that with economic globalization in the developing world, a Western, hegemonic notion of lesbian, gay, bisexual and transgender (LGBT) identity has been exported to traditional societies thereby destroying indigenous sexual cultures and diversities, other scholars do not consider globalization as a significant factor in global queer mobilization and sexual identity politics. This paper aims at exploring the debate around globalization and contemporary queer politics in developing world with special reference to India. After briefly tracing the history of sexual identity politics, this paper examines the process of queer mobilization in relation to emergence of HIV/AIDS epidemic and forces of neoliberal globalization. I argue that the twin-process of globalization and AIDS epidemic has significantly influenced the mobilization of queer communities, while simultaneously strengthening right wing "homophobic" discourses of heterosexist nationalism in India
Nanobiotechnology can boost crop production and quality: first evidence from increased plant biomass, fruit yield and phytomedicine content in bitter melon (Momordica charantia)
BACKGROUND:
Recent research on nanoparticles in a number of crops has evidenced for enhanced germination and seedling growth, physiological activities including photosynthetic activity and nitrogen metabolism, mRNA expression and protein level, and also positive changes in gene expression indicating their potential use in crop improvement. We used a medicinally rich vegetable crop, bitter melon, as a model to evaluate the effects of seed treatment with a carbon-based nanoparticle, fullerol [C60(OH)20], on yield of plant biomass and fruit characters, and phytomedicine contents in fruits. RESULTS:
We confirmed the uptake, translocation and accumulation of fullerol through bright field imaging and Fourier transform infra-red spectroscopy. We observed varied effects of seed treatment at five concentrations, including non-consequential and positive, on plant biomass yield, fruit yield and its component characters, and content of five phytomedicines in fruits. Fullerol-treatment resulted in increases up to 54% in biomass yield and 24% in water content. Increases of up to 20% in fruit length, 59% in fruit number, and 70% in fruit weight led to an improvement up to 128% in fruit yield. Contents of two anticancer phytomedicines, cucurbitacin-B and lycopene, were enhanced up to 74% and 82%, respectively, and contents of two antidiabetic phytomedicines, charantin and insulin, were augmented up to 20% and 91%, respectively. Non-significant correlation inter se plant biomass, fruit yield, phytomedicine content and water content evidenced for separate genetic control and biosynthetic pathways for production of plant biomass, fruits, and phytomedicines in fruits, and also no impact of increased water uptake. CONCLUSIONS:
While our results indicated possibility of improving crop yield and quality by using proper concentrations of fullerol, extreme caution needs to be exercised given emerging knowledge about accumulation and toxicity of nanoparticles in bodily tissues
Arteriovenous malformations of the corpus callosum: Pooled analysis and systematic review of literature
BACKGROUND: Arteriovenous malformations (AVMs) of the corpus callosum (CC) are rare entities. We performed a systematic review of the available literature to better define the natural history, patient characteristics, and treatment options for these lesions.
METHODS: A MEDLINE, Google Scholar, and The Cochrane Library search were performed for studies published through June 2015. Data from all eligible studies were used to examine epidemiology, natural history, clinical features, treatment strategies, and outcomes of patients with CC-AVMs. A systematic review and pooled analysis of the literature were performed.
RESULTS: Our search yielded 37 reports and 230 patients. Mean age at presentation was 26.8 years (±13.12 years). AVMs were most commonly located in the splenium (43%), followed by the body (31%), and then the genu (23%) of the CC. A Spetzler-Martin grade of III was the most common (37%). One hundred eighty-seven (81.3%) patients presented with hemorrhage, 91 (40%) underwent microsurgical excision, and 87 (38%) underwent endovascular embolization. Radiosurgery was performed on 57 (25%) patients. Complete obliteration of the AVM was achieved in 102 (48.1%) patients and approximately twice as often when microsurgery was performed alone or in combination with other treatment modalities (94% vs. 49%; P \u3c 0.001). Mean modified Rankin Scale (mRS) at presentation was 1.54 and mean mRS at last follow-up was 1.31. This difference was not statistically significant (P = 0.35).
CONCLUSION: We present an analysis of the pooled data in the form of a systematic review focusing on management of CC-AVMs. This review aims to provide a valuable tool to aid in decision making when dealing with this particular subtype of AVM
Man-in-the-barrel syndrome: Case report of ventral epidural abscess and review of the literature
Background: Man-in-the-barrel syndrome (MBS) is an uncommon clinical condition for which patients present with bilateral brachial diplegia but intact lower extremity strength. This syndrome is typically attributed to a cranial/cortical injury rather than a spinal pathology.
Case Description: A 62-year-old diabetic male presented with bilateral upper extremity paresis attributed to a ventral cervical epidural abscess diagnosed on magnetic resonance imaging. Emergent cervical decompression resulted in slight improvement of upper extremity strength. However, he later expired due to sepsis and respiratory compromise.
Conclusion: Establishing the correct diagnosis via clinical examination and proceeding with appropriate management of MBS attributed to a cervical epidural abscess is critical to achieve a good outcome
Saltatory Conduction along Myelinated Axons Involves a Periaxonal Nanocircuit
The propagation of electrical impulses along axons is highly accelerated by the myelin sheath and pro- duces saltating or ‘‘jumping’’ action potentials across internodes, from one node of Ranvier to the next. The underlying electrical circuit, as well as the existence and role of submyelin conduction in salta- tory conduction remain, however, elusive. Here, we made patch-clamp and high-speed voltage-cali- brated optical recordings of potentials across the nodal and internodal axolemma of myelinated neocortical pyramidal axons combined with electron microscopy and experimentally constrained cable modeling. Our results reveal a nanoscale yet conduc- tive periaxonal space, incompletely sealed at the paranodes, which separates the potentials across the low-capacitance myelin sheath and internodal axolemma. The emerging double-cable model repro- duces the recorded evolution of voltage waveforms across nodes and internodes, including rapid nodal potentials traveling in advance of attenuated waves in the internodal axolemma, revealing a mechanism for saltation across time and space
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