2,735 research outputs found
Could surgery be the gold standard in moderate and severe ischaemic colitis? Atypical case description and review of literature
Induction of thermotolerance through heat acclimation in lablab bean (Dolichos lablab)
The acclimation of plants to moderately high temperature plays an important role in inducing plant tolerance to subsequent lethal temperatures. This study was performed to investigate the effects of heat acclimation and sudden heat stress on the antioxidant and metabolic profile of lablab bean (Dolichos lablab). Following separate pretreatments with heat acclimation (35°C) and NaCl (100 mM), seedlings of lablab bean were exposed to heat stress at 45°C for 5 h and then recovered at 25°C for five days. Pretreated seedlings performed better under heat stress than the control and it could be associated with the observed increased levels of sugars, proline, glutathione and ascorbate; and increased activities of Peroxidase (POX), glutathione reductase (GR) and ascorbate peroxidase (APX) than just heat shocked seedlings. Seedling growth was dramatically reduced under heat stress but heat acclimation and NaCl pre-treatment were effective in imparting thermoprotection against the lethal heat shock.Keywords: Acclimation, antioxidants, catalase, Dolichos lablab, glutathione reductase, heat stress, peroxidase, proline, sugar.African Journal of Biotechnology Vol. 12(38), pp. 5695-570
3-Ethyl-6-(4-fluorophenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine
In the title compound, C12H11FN4S, the thiadiazine ring adopts a twist-boat conformation. The dihedral angle between the triazolothiadiazine system and the benzene ring is 10.54 (9)°. The crystal structure is characterized by C—H⋯N hydrogen bonds. The crystal packing also exhibits π–π interactions, with a centroid–centroid distance of 3.6348 (15) Å
Oxidative stress biomarkers and metabolic changes associated with cadmium stress in hyacinth bean (Lablab Purpureus)
Cadmium (Cd)-induced stress in hyacinth bean (Lablab purpureus) was investigated by growing seedlings in a nutrient solution containing increasing cadmium concentrations (0 to 50 μM), under strictly controlled growth conditions. Changes consequent to Cd uptake in growth parameters, enzyme activities and other stress response factors directly or indirectly are related to the cellular free radical scavenging systems. Antioxidants and other stress response components were studied in roots and leaves of 10-day old seedlings over 72 h of exposure. A significant decrease in length, relative water content (RWC), weight of shoot and root, and chlorophyll content was observed in seedlings growing on >10 μM CdCl2. Oxidative stress markers, H2O2, malondialdehyde, proline and total soluble sugars were elevated in both leaves and roots. Ascorbate and phenol contents increased in leaves, but, decreased in roots. Reduced glutathione levels declined in both tissues. Cd stress enhanced antioxidant enzymes, guaiacol peroxidase, glutathione reductase, ascorbate peroxidase and polyphenol oxidase in concentration and time dependent manner in leaves. Antioxidant enzymes in roots showed inverse relationship with concentration and time of exposure. Catalase activity was found to decrease in both leaves and roots. Metabolic enzymes β-amylase and acid phosphatase activity increased in both leaves and roots. The results suggest that primary antioxidative response originates from leaves of Hyacinth bean even though roots are involved in direct uptake of heavy metals. The root tends to accumulate Cd and thus excludes its uptake by leaves.Keywords: Antioxidants, antioxidant enzymes, cadmium, Hyacinth bean.African Journal of Biotechnology Vol. 12(29), pp. 4670-468
Performance Analysis of Mesh-based NoC’s on Routing Algorithms
The advent of System-on-Chip (SoCs), has brought about a need to increase the scale of multi-core chip networks. Bus Based communications have proved to be limited in terms of performance and ease of scalability, the solution to both bus – based and Point-to-Point (P2P) communication systems is to use a communication infrastructure called Network-on-Chip (NoC). Performance of NoC depends on various factors such as network topology, routing strategy and switching technique and traffic patterns. In this paper, we have taken the initiative to compile together a comparative analysis of different Network on Chip infrastructures based on the classification of routing algorithm, switching technique, and traffic patterns. The goal is to show how varied combinations of the three factors perform differently based on the size of the mesh network, using NOXIM, an open source SystemC Simulator of mesh-based NoC. The analysis has shown tenable evidence highlighting the novelty of XY routing algorithm
Network Growth with Feedback
Existing models of network growth typically have one or two parameters or
strategies which are fixed for all times. We introduce a general framework
where feedback on the current state of a network is used to dynamically alter
the values of such parameters. A specific model is analyzed where limited
resources are shared amongst arriving nodes, all vying to connect close to the
root. We show that tunable feedback leads to growth of larger, more efficient
networks. Exact results show that linear scaling of resources with system size
yields crossover to a trivial condensed state, which can be considerably
delayed with sublinear scaling.Comment: 4 pages, 4 figure
Teachers developing assessment for learning: impact on student achievement
While it is generally acknowledged that increased use of formative assessment (or assessment for learning) leads to higher quality learning, it is often claimed that the pressure in schools to improve the results achieved by students in externally-set tests and examinations precludes its use. This paper reports on the achievement of secondary school students who worked in classrooms where teachers made time to develop formative assessment strategies. A total of 24 teachers (2 science and 2 mathematics teachers, in each of six schools in two LEAs) were supported over a six-month period in exploring and planning their approach to formative assessment, and then, beginning in September 1999, the teachers put these plans into action with selected classes. In order to compute effect sizes, a measure of prior attainment and at least one comparison group was established for each class (typically either an equivalent class taught in the previous year by the same teacher, or a parallel class taught by another teacher). The mean effect size was 0.32
The Stability of Double White Dwarf Binaries Undergoing Direct Impact Accretion
We present numerical simulations of dynamically unstable mass transfer in a
double white dwarf binary with initial mass ratio, q = 0.4. The binary
components are approximated as polytropes of index n = 3/2 and the initially
synchronously rotating, semi-detached equilibrium binary is evolved
hydrodynamically with the gravitational potential being computed through the
solution of Poisson's equation. Upon initiating deep contact in our baseline
simulation, the mass transfer rate grows by more than an order of magnitude
over approximately ten orbits, as would be expected for dynamically unstable
mass transfer. However, the mass transfer rate then reaches a peak value, the
binary expands and the mass transfer event subsides. The binary must therefore
have crossed the critical mass ratio for stability against dynamical mass
transfer. Despite the initial loss of orbital angular momentum into the spin of
the accreting star, we find that the accretor's spin saturates and angular
momentum is returned to the orbit more efficiently than has been previously
suspected for binaries in the direct impact accretion mode. To explore this
surprising result, we directly measure the critical mass ratio for stability by
imposing artificial angular momentum loss at various rates to drive the binary
to an equilibrium mass transfer rate. For one of these driven evolutions, we
attain equilibrium mass transfer and deduce that effectively q_crit has evolved
to approximately 2/3. Despite the absence of a fully developed disk, tidal
interactions appear effective in returning excess spin angular momentum to the
orbit.Comment: 27 pages, 6 figures. Please see
http://www.phys.lsu.edu/faculty/tohline/astroph/mftd07/ for animations and
full resolution figures. Accepted for publication in the Astrophysical
Journa
Additional Muscle Slip of Bicipital Aponeurosis and its Anomalous Relationship with the Median Cubital Vein
The cubital region of the arm is a common site for recording blood pressure, taking blood for analysis and administering intravenous therapy and blood transfusions. During the routine dissection of a 70-year-old male cadaver at the Kasturba Medical College, Manipal, Karnataka, India, in 2015, it was observed that the aponeurotic insertion of the biceps brachii muscle divided into two slips. The medial slip fused normally with the deep fascia of the forearm, while flexor carpi radialis muscle fibres originated from the lateral slip. There was also a single vein in the forearm, the cephalic vein, which bifurcated to form the median cubital vein and the cephalic vein proper. The median cubital vein, further reinforced by the radial vein, passed deep to the two slips of the bicipital aponeurosis and then continued as the basilic vein. During venepuncture, medical practitioners should be aware of potential cubital fossa variations which could lead to nerve entrapment syndromes
Venture Capital Funding for Information Technology Businesses
The success of new ventures can hinge on obtaining venture capital (VC) funding. Virtually every successful IT venture has depended on VC funding early in its history. However, obtaining venture capital is difficult. Unlike earlier studies on VC funding that consider new ventures to be homogeneous, this study seeks to identify factors that VCs consider when they make funding decisions for IT ventures. Building on prior research in the area of agency and business risk, we develop a theoretical model that draws on work in finance and entrepreneurship. The model suggests that VCs consider two types of risk: business risk and agency risk. The relative importance of these two types of risk may be different across industries. We test this model using data from 139 business plans for IT startups that were considered for funding by VCs. Traditional structural equation modeling (SEM) does not accommodate non-normal data or dichotomous outcome variables. Using the Robust Weighted Least Squares approach, we test our model with non-normal data and dichotomous outcomes. In addition, we use Tetrad analysis to check model fit against alternative models, floor and ceiling analysis to test sample frame validity, relative effect size comparison to test relative elasticity of effects, and a Monte Carlo estimation approach to test overall model power and power of individual paths. We find that business risk is an important factor in start-up funding for IT ventures. We do not find agency risk to be an important consideration in start-up funding for IT ventures
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