233 research outputs found
Inbreeding in Rainbow Trout (Salmo gairdneri): Analysis of Lethal Temperature Tolerence
Inbreeding in rainbow trout (Salmo gairdneri) was evaluated in relation to an altered environment (upper lethal temperature 29 C), at four levels of inbreeding. At each level of inbreeding mean time to death for inbred, female-outbred half-sib, male-outbred half-sib and outbred families were evaluated. In all cases inbreds were less resistant to lethal temperature than were respective outbred families. Analysis of variance 9Snedecor’s F) and multiple range analysis (Tukey’s “w” procedure) provided inference limitations. Inbred fish were 82% less resistant to lethal temperature as comared to the respective outbred family at 50% inbreeding and 19% less resistant at 25% inbreeding. How inbreeding practices influence stocks of rainbow trout are summarized below: A. Domestic stocks of rainbow trout are inbred to an unknown and varying degree. B. Inbreeding has been common in domestic fish stock for over 100 years in the United States. C. Stocking domestic fish in natural waters has destroyed most genetically unique populations probably by genetic “dilution”. D. Millions of hatchery fish have been broadcasted internationally with unknown consequences in regard to the genetic structure of the original wild populations. E. Inbred groups can show increased phenotypic variation when compared to their outbred countergroups for some traits. F. Highly inbred fish may suffer reduced genetic variability lowering tolerance to environmental rates
Moleclar-dynamics simulations using spatial decomposition and task-based parallelism
Molecular Dynamics (MD) simulations are an integral method in the computational studies of
materials. This thesis discusses an algorithm for large-scale MD simulations using modern multiand
many-core systems on distributed computing networks. In order to utilize the full processing
power of these systems, algorithms must be updated to account for newer hardware, such as the
many-core Intel Xeon Phi co-processor.
The hybrid method is a data-parallel method of parallelization which combines spatial decomposition
using the Message Passing Interface (MPI) to distribute the system onto multiple nodes,
along with the cell-task method used for task based parallelism on each node. This allows for the
improved performance of task based parallelism on single compute nodes in addition to the benefit
of distributed computing allowed by MPI.
Results from benchmark simulations on Intel Xeon multi-core processors, and Intel Xeon Phi
coprocessors are presented. Results show that the hybrid method provides better performance
than either spatial decomposition or cell-task methods alone on single nodes, and that the hybrid
method outperforms the spatial decomposition method on multiple nodes, on a variety of system
configurations.Master of Science (MSc) in Computational Science
Parallelization of Molecular-Dynamics Simulations Using Tasks
Copyright: © 2015 Materials Research SocietyThis article discusses novel algorithms for molecular-dynamics (MD) simulations with short-ranged forces on modern multi- and many-core processors like the Intel Xeon Phi. A task-based approach to the parallelization of MD on shared-memory computers and a tiling scheme to facilitate the SIMD vectorization of the force calculations is described. The algorithms have been tested with three different potentials and the resulting speed-ups on Intel Xeon Phi coprocessors are shown.Natural Sciences and Engineering Research Council of Canada (NSERC) [grant number 371446-11], Laurentian Universit
antitumor and anti nematode activities of α mangostin
Abstract α-Mangostin, one of the major xanthones isolated from pericarp of mangosteen (Garcinia mangostana Linn), exhibits a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial as well as anticancer, both in in vitro and in vivo studies. In the present study, α-mangostin' anti-cancer and anti-parasitic properties were tested in vitro against three human cell lines, including squamous carcinoma (SCC-15) and glioblastoma multiforme (U-118 MG), compared to normal skin fibroblasts (BJ), and in vivo against Caenorhabditis elegans. The drug showed cytotoxic activity, manifested by decrease of cell viability, inhibition of proliferation, induction of apoptosis and reduction of adhesion at concentrations lower than 10 μM (the IC50 values were 6.43, 9.59 and 8.97 μM for SCC-15, U-118 MG and BJ, respectively). The toxicity, causing cell membrane disruption and mitochondria impairment, was selective against squamous carcinoma with regard to normal cells. Moreover, for the first time anti-nematode activity of α-mangostin toward C. elegans was described (the LC50 = 3.8 ± 0.5 μM), with similar effect exerted by mebendazole, a well-known anthelmintic drug
The Pictet-Spengler reaction updates its habits
The Pictet-Spengler reaction (P-S) is one of the most direct, efficient, and variable synthetic method for the construction of privileged pharmacophores such as tetrahydroisoquinolines (THIQs), tetrahydro-β-carbolines (THBCs), and polyheterocyclic frameworks. In the lustro (five-year period) following its centenary birthday, the P-S reaction did not exit the stage but it came up again on limelight with new features. This review focuses on the interesting results achieved in this period (2011–2015), analyzing the versatility of this reaction. Classic P-S was reported in the total synthesis of complex alkaloids, in combination with chiral catalysts as well as for the generation of libraries of compounds in medicinal chemistry. The P-S has been used also in tandem reactions, with the sequences including ring closing metathesis, isomerization, Michael addition, and Gold- or Brønsted acid-catalyzed N-acyliminium cyclization. Moreover, the combination of P-S reaction with Ugi multicomponent reaction has been exploited for the construction of highly complex polycyclic architectures in few steps and high yields. The P-S reaction has also been successfully employed in solid-phase synthesis, affording products with different structures, including peptidomimetics, synthetic heterocycles, and natural compounds. Finally, the enzymatic version of P-S has been reported for biosynthesis, biotransformations, and bioconjugations
Gunshot Injury to the Anterior Arch of Atlas
Penetrating injuries to the upper cervical spine resulting from gunshots are rare in South Korea due to restrictions of gun use. Moreover, gunshot wounds to the upper cervical spine without neurological deficits occur infrequently because of the anatomic location and surrounding essential structures. We present an uncommon case involving the surgical removal of a bullet located in the anterior arch of first cervical vertebra (C1) via a transoral approach without neurological complications or subsequent mechanical instability
Naturally-occurring alkaloids of plant origin as potential antimicrobials against antibiotic-resistant infections
Antibiotic resistance is now considered a worldwide problem that puts public health at risk. The onset of bacterial strains resistant to conventional antibiotics and the scarcity of new drugs have prompted scientific research to re-evaluate natural products as molecules with high biological and chemical potential. A class of natural compounds of significant importance is represented by alkaloids derived from higher plants. In this review, we have collected data obtained from various research groups on the antimicrobial activities of these alkaloids against conventional antibiotic-resistant strains. In addition, the structure-function relationship was described and commented on, highlighting the high potential of alkaloids as antimicrobials
Intra-operative real time intracranial subarachnoid haemorrhage during glial tumour resection: A case report
Glial tumours associated with subarachnoid haemorrhage are very rare. A 64-year-old woman admitted with a history of 3 weeks seizures and a left sided hemiparesis and dysphasia. The magnetic resonance disclosed heterogeneously enhancing a right temporal mass. During surgery, suddenly an abrupt and extensive swelling had occurred both in tumour and the brain tissue. The surgery was completed with a gross total tumour resection together with a partial temporal lobectomy. Postoperative computerized tomography demonstrated a massive subarachnoid hemorrhage (SAH). A cerebral Magnetic Resonance (MR) angiography showed neither an aneurysm nor arteriovenous malformation. Coincidence of an intracerebral tumour and subarachnoid haemorrhage would be devastating
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