151 research outputs found

    Divisible load scheduling of image processing applications on the heterogeneous star and tree networks using a new genetic algorithm

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    The divisible load scheduling of image processing applications on the heterogeneous star and multi-level tree networks is addressed in this paper. In our platforms, processors and network links have different speeds. In addition, computation and communication overheads are considered. A new genetic algorithm for minimizing the processing time of low-level image applications using divisible load theory is introduced. The closed-form solution for the processing time, the image fractions that should be allocated to each processor, the optimum number of participating processors, and the optimal sequence for load distribution are derived. The new concept of equivalent processor in tree network is introduced and the effect of different image and kernel sizes on processing time and speed up are investigated. Finally, to indicate the efficiency of our algorithm, several numerical experiments are presented

    Conserved visual capacity of rats under red light

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    Recent studies examine the behavioral capacities of rats and mice with and without visual input, and the neuronal mechanisms underlying such capacities. These animals are assumed to be functionally blind under red light, an assumption that might originate in the fact that they are dichromats who possess ultraviolet and green but not red cones. But the inability to see red as a color does not necessarily rule out form vision based on red light absorption. We measured Long-Evans rats’ capacity for visual form discrimination under red light of various wavelength bands. Upon viewing a black and white grating, they had to distinguish between two categories of orientation, horizontal and vertical. Psychometric curves plotting judged orientation versus angle demonstrate the conserved visual capacity of rats under red light. Investigations aiming to explore rodent physiological and behavioral functions in the absence of visual input should not assume red-light blindness

    Short communication: optimization of semi-quantitative RT PCR analysis for CPT I gene expression in rainbow trout (Oncorhynchus mykiss)

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    A key enzyme in mitochondrial β¬oxidation, carnitine palmitoyltransferase (CPT) I, is transcriptionally regulated in mammals, but this enzyme also experiences allosteric modulations (Harano et al., 1985; Murthy and Pande, 1987; Bezaire et al., 2004). CPT I is located on the inner side of the outer mitochondrial membrane and catalyses the conversion of acyl-CoA to fatty acylcarnitine (Kerner and Hoppel, 2000; Price et al., 2000). Quantitative RT-PCR is a reliable technique for measuring transcripts in small amounts of tissue (Spriewald et al., 2000). With this technique, multiple mRNAs can be assayed simultaneously in a relatively short period of time. Here we describe the standard procedure, optimized in our laboratory, to assess CPT I levels with β¬actin as an internal control in rainbow trout, and all the necessary controls to ensure a quantitative analysis. RNA Extraction and Reverse Transcription Total cellular RNA was isolated from liver of rainbow trout using RNX reagent (Cinnagen-Iran). To obtain cDNA, 1 µg of total RNA was subjected to reverse transcription polymerase chain reaction (RT-PCR) with MuLV reverse transcriptase using the RevertAidTM M¬MuLV Reverse Transcriptase Kit (Fermentase Life Science, Germany) and random hexamer primer. Reaction conditions in the reverse transcription step are mostly dependent on the enzyme and the primers of choice. Whereas other protocols to require the use of specific primers, we prefer to reverse transcribe the total RNA population with random hexamers so that different PCR analyses could be performed on the same cDNA sample

    Protection of hippocampal CA1 neurons against ischemia/Reperfusion injury by exercise preconditioning via modulation of Bax/Bcl-2 ratio and prevention of Caspase-3 Activation

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    Introduction: Ischemia leads to loss of neurons by apoptosis in specific brain regions, especially in the hippocampus. The purpose of this study was investigating the effects of exercise preconditioning on expression of Bax, Bcl-2, and caspase-3 proteins in hippocampal CA1 neurons after induction of cerebral ischemia. Methods: Male rats weighing 260-300 g were randomly allocated into three groups (sham, exercise, and ischemia). The rats in exercise group were trained to run on atreadmill 5 days a week for 4 weeks. Ischemia was induced by the occlusion of both common carotid arteries (CCAs) for 20 min. Levels of expression of Bax, Bcl-2, and caspase-3 proteins in CA1 area of hippocampus were determined by immunohistochemical staining . Results: The number of active caspase-3-positive neurons in CA1 area were significantly increased in ischemia group, compared to sham-operated group (P<0.001), and exercise preconditioning significantly reduced the ischemia/reperfusion-induced caspase-3 activation, compared to the ischemia group (P<0.05). Also, results indicated a significant increase in Bax/Bcl-2 ratio in ischemia group, compared to sham-operated group (P<0.001). Discussion: This study indicated that exercise has a neuroprotective effects against cerebral ischemia when used as preconditioning stimuli

    Development of anti-Helicobacter pylori immunoglobulins Y (IgYs) in quail

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    Summary Helicobacter pylori (H. pylori) is a gram-negative, microaerophilic bacterium that cause the stomach infection in more than 50% of human population worldwide. The aim of this study was to examine the possibility of anti-H. pylori immunoglobulins Y (IgYs) production in quails and evaluate the effect of the different methods of immunization on titers of IgY in egg yolks. Whole cell bacterial antigen was used for immunization of quails. Forty Japanese quails (Coturnix japonica) were divided into four groups. The first group intramuscularly immunized with one dose of antigen (3 × 10 8 inactivated bacteria) whereas the second group injected with half dose. Third group administered orally. Yolk IgY was isolated using precipitation method of water dilution combined with chloroform. Dot-blot and ELISA (enzyme-linked immunosorbent assay) were used for determining the specificity and quantifying the titer of IgY in egg yolks. Results showed that quails as well as chickens are able to produce anti-H. pylori IgY. Quails antibodies have high titer and specificity that can be used in therapeutic and research purposes. This study indicated that higher amounts of antigen can not develop higher titer of IgY and injection is not necessary for efficient immunization of the quail against H. pylori

    In vivo E2F reporting reveals efficacious schedules of MEK1/2–CDK4/6 targeting and mTOR–s6 resistance mechanisms

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    Targeting cyclin-dependent kinases 4/6 (CDK4/6) represents a therapeutic option in combination with BRAF inhibitor and/or MEK inhibitor (MEKi) in melanoma; however, continuous dosing elicits toxicities in patients. Using quantitative and temporal in vivo reporting, we show that continuous MEKi with intermittent CDK4/6 inhibitor (CDK4/6i) led to more complete tumor responses versus other combination schedules. Nevertheless, some tumors acquired resistance that was associated with enhanced phosphorylation of ribosomal S6 protein. These data were supported by phospho-S6 staining of melanoma biopsies from patients treated with CDK4/6i plus targeted inhibitors. Enhanced phospho-S6 in resistant tumors provided a therapeutic window for the mTORC1/2 inhibitor AZD2014. Mechanistically, upregulation or mutation of NRAS was associated with resistance in in vivo models and patient samples, respectively, and mutant NRAS was sufficient to enhance resistance. This study utilizes an in vivo reporter model to optimize schedules and supports targeting mTORC1/2 to overcome MEKi plus CDK4/6i resistance. SIGnIFICAnCE: Mutant BRAF and NRAS melanomas acquire resistance to combined MEK and CDK4/6 inhibition via upregulation of mTOR pathway signaling. This resistance mechanism provides the preclinical basis to utilize mTORC1/2 inhibitors to improve MEKi plus CDK4/6i drug regimens

    The protective role of carnosic acid against beta-amyloid toxicity in rats

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    Oxidative stress is one of the pathological mechanisms responsible for the beta- amyloid cascade associated with Alzheimer's disease (AD). Previous studies have demonstrated the role of carnosic acid (CA), an effective antioxidant, in combating oxidative stress. A progressive cognitive decline is one of the hallmarks of AD. Thus, we attempted to determine whether the administration of CA protects against memory deficit caused by beta-amyloid toxicity in rats. Beta-amyloid (1-40) was injected by stereotaxic surgery into the Ca1 region of the hippocampus of rats in the Amyloid beta (Aβ) groups. CA was delivered intraperitoneally, before and after surgery in animals in the CA groups. Passive avoidance learning and spontaneous alternation behavior were evaluated using the shuttle box and the Y-maze, respectively. The degenerating hippocampal neurons were detected by fluoro-jade b staining. We observed that beta-amyloid (1-40) can induce neurodegeneration in the Ca1 region of the hippocampus by using fluoro-jade b staining. Also, the behavioral tests revealed that CA may recover the passive avoidance learning and spontaneous alternation behavior scores in the Aβ + CA group, in comparison with the Aβ group. We found that CA may ameliorate the spatial and learning memory deficits induced by the toxicity of beta-amyloid in the rat hippocampus. © 2013 H. Rasoolijazi et al
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