1,054 research outputs found

    Role of histaminegic and calcium channels in the inhibitory effects of hydroalcoholic extract of matricaria recutita L. on isolated rabbit jejunum

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    Introduction: Considering the long traditional history of anti-inflammatory and anti-spasmodic effects of Matricria spices on the gastrointestinal system, the present study aimed to investigate the role of calcium channels and Histamine receptors in the inhibitory effects of hydroalcoholic dry extract of German chamomile (Matricaria recutita L.) on the isolated rabbit jejunum. Methods: All experiments were done on the isolated jejunum of New Zealand rabbits (1.8-2.5 kg). Dry extract of aerial parts of M. recutita was obtained by the maceration technique. The study was performed on two groups (n=6 in each group). In the first group, the effects of cumulative concentrations of M. recutita (3×10-3-1×10-2 mg/ml) on normal and K+-induced contractions (50 mM) of isolated jejunum were studied. In the second group, the inhibitory role of M. recutita (3 – 13×10-3 mg/ml) was evaluated in the presence and absence of histamine and cetrizine. In the presence and absence of 10 μM certizine, a histamine H1-antagonist, a concentration-dependent inhibitory effect of M. recutita extract in the range of 3-13×10-3 mg/ml was recorded the rabbit jejunum. Results: Results showed that EC50 of M. recutita in the absence and presence of K+ was 6.3×10-3 and 6.5×10- 3mg/ml, respectively. IC50 values for two concentrations of M. recutita (8×10-3 , 1×10-2 ) to abrogated contractive phase of Histamine was 9.55 × 10-6 and 1.57 × 10-6 μM. Cetrizine (10 μM) abolished inhibitory effects of M. recutita (IC50=3.6×10-3), (p< 0.001). Conclusion: Dry extract of matricaria recutita had inhibitory effects on the contractions of isolated rabbit jejunum. Calcium channels and histamine were involved in these antispasmodic effects

    Entanglement Transfer via XXZ Heisenberg chain with DM Interaction

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    The role of spin-orbit interaction, arises from the Dzyaloshinski-Moriya anisotropic antisymmetric interaction, on the entanglement transfer via an antiferromagnetic XXZ Heisenberg chain is investigated. From symmetrical point of view, the XXZ Hamiltonian with Dzyaloshinski-Moriya interaction can be replaced by a modified XXZ Hamiltonian which is defined by a new exchange coupling constant and rotated Pauli operators. The modified coupling constant and the angle of rotations are depend on the strength of Dzyaloshinski-Moriya interaction. In this paper we study the dynamical behavior of the entanglement propagation through a system which is consist of a pair of maximally entangled spins coupled to one end of the chain. The calculations are performed for the ground state and the thermal state of the chain, separately. In both cases the presence of this anisotropic interaction make our channel more efficient, such that the speed of transmission and the amount of the entanglement are improved as this interaction is switched on. We show that for large values of the strength of this interaction a large family of XXZ chains becomes efficient quantum channels, for whole values of an isotropy parameter in the region 2Δ2-2 \leq \Delta \leq 2.Comment: 21 pages, 9 figure

    The impact of the Arab Spring on democracy and development in the MENA region

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    © 2019 John Wiley & Sons Ltd. In evaluating the consequences of the Arab Spring 8 years later, this paper not only focuses on the short-term consequences of the uprisings that swept through a number of countries in the Middle East and North African region but also analyzes the long-term prospects for democratization and development in the MENA region. The impact of the Arab Spring, despite its promises and the expectations of the rest of the world, has been dismal. While only Tunisia made a successful transition to a democratic polity with a constitution guaranteeing the basic rights of the people, the rest of the Arab Spring countries remain in the grip of the authoritarian rule, and countries such as Syria, Libya, and Yemen have been degenerated into bloody civil wars with dwindling hope of peace and freedom. On economic front, the growth has been tardy, showing little difference with countries that were unaffected by the Arab Spring. Yet, the paper concludes, echoing historian Eric Hobsbawm\u27s view, that revolutionary outcomes need not be judged as failure too quickly as they are likely to be partial success in the long term. The impact may be observed in the area of social opening, newer class alliances, and the emergence of a less rapacious, reformed, hybrid authoritarianism

    Antibacterial activity of certain Iranian medicinal plants against methicillin-resistant and sensitive Staphylococcus aureus

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    Bacterial resistance to antibiotics is a serious global problem and includes strains of beta-lactam-resistant Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). Novel antimicrobials and/or new approaches to combat the problem are urgently needed. The aim of this study was to investigate the antimicrobial activity of alcoholic and aqueous extract of 23 medical plants species of Golestan province on clinical and standard stains of MRSA and MSSA. Twenty three medicinal plants were collected from their natural habitat in Golestan province in north of Iran. Their ethanolic and aqueous extract obtained by percolation methods. Antibacterial effects were assessed by disk diffusion method and the Minimum Inhibitory Concentration (MIC) of the extracts was determined by the micro broth dilution against 14 clinical and standard strains of methicillin resistant and sensitive of Staphylococcus aureus. The ethanolic and aqueous extract of 8, 3 plants showed best anti staphylococcal effect, respectively. The ethanolic extract of Artemisia, herbaalba, Nigella sativa, Punica granatum, possed the most outstanding in vitro antibacterial activity which the maximum inhibition zone was 22.4-18 mm, respectively and the lowest MIC values was measured in Punica granatum, as 0.01 mg mL-1 against MRSA The results showed that ethanolic extract had better antibacterial effect than aqueous extract and anti staphylococcal activity of Ethanolic extract of plants against MRSA was better than MSSA strains. Ethanolic and aqueous extract of Punica granatum had the best antibacterial activity against the tested microorganisms. The result obtained from these plants might be considered sufficient for further studies. © 2006 Asian Network for Scientific Information

    Discrete Model of Ideological Struggle Accounting for Migration

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    A discrete in time model of ideological competition is formulated taking into account population migration. The model is based on interactions between global populations of non-believers and followers of different ideologies. The complex dynamics of the attracting manifolds is investigated. Conversion from one ideology to another by means of (i) mass media influence and (ii) interpersonal relations is considered. Moreover a different birth rate is assumed for different ideologies, the rate being assumed to be positive for the reference population, made of initially non-believers. Ideological competition can happen in one or several regions in space. In the latter case, migration of non-believers and adepts is allowed; this leads to an enrichment of the ideological dynamics. Finally, the current ideological situation in the Arab countries and China is commented upon from the point of view of the presently developed mathematical model. The massive forced conversion by Ottoman Turks in the Balkans is briefly discussed.Comment: 24 pages, with 5 figures and 52 refs.; prepared for a Special issue of Advances in Complex System

    Food systems approach: reversing the trajectory of food insecurity in Africa

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    A goal of the United Nations is to end hunger by 2030 but diverse factors, including global warming, conflict and now the war in Ukraine, place that ambition in jeopardy. AMIENA BAYAT, CLAIRE QUINN, JULIAN MAY and HEMISH GOVERA argue that the world can end hunger in Africa if it takes proper note of the framework of the African food systems approach

    Redesigning Commercial Floating-Gate Memory for Analog Computing Applications

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    We have modified a commercial NOR flash memory array to enable high-precision tuning of individual floating-gate cells for analog computing applications. The modified array area per cell in a 180 nm process is about 1.5 um^2. While this area is approximately twice the original cell size, it is still at least an order of magnitude smaller than in the state-of-the-art analog circuit implementations. The new memory cell arrays have been successfully tested, in particular confirming that each cell may be automatically tuned, with ~1% precision, to any desired subthreshold readout current value within an almost three-orders-of-magnitude dynamic range, even using an unoptimized tuning algorithm. Preliminary results for a four-quadrant vector-by-matrix multiplier, implemented with the modified memory array gate-coupled with additional peripheral floating-gate transistors, show highly linear transfer characteristics over a broad range of input currents.Comment: 4 pages, 6 figure

    The decrease in NKG2D+ Natural Killer cells in peripheral blood of patients with metastatic colorectal cancer

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    Background: Natural killer (NK) cells play important roles in the immune defense against tumors such as colorectal cancer. In humans, NKG2D is an activating immune receptor constitutively expressed in most cytotoxic lymphocytes including NK and CD8+ T cells. In this study, the expression of NKG2D molecule was investigated in peripheral blood NK cells from colorectal cancer patients and compared with healthy subjects. Methods: We studied 21 non-metastatic (low-grade), 17 non-metastatic (high-grade), 16 metastatic colorectal cancer patients, and 24 healthy controls. Peripheral blood samples were obtained to isolate peripheral blood mononuclear cells (PBMCs) and the percentage of peripheral blood NKG2D+CD3-CD56+ NK cells was analyzed by flow cytometry. The expression of NKG2D at mRNA level was also measured by real-time PCR in both, patients and control subjects. Results: The results showed a significant reduction in the percentage of NKG2D+NK cells as well as NKG2D mRNA expression in peripheral blood of metastatic colon cancer patients. Conclusion: This result suggests that decreased expression of activating NKG2D receptor in metastatic colorectal cancer might compromise NK cell function and allow tumor to evade immunity (Tab. 3, Fig. 4, Ref. 33). Text in PDF www.elis.sk

    Energy utilization and milk fat responses to rapeseed oil when fed to lactating dairy cows receiving different dietary forage to concentrate ratio

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    We evaluated energy and N utilization, performance, and milk fatty acid (FA) profile using grass silage-based diets when rapeseed oil (RO) was included in high- or low-forage diets. Four multiparous Nordic Red cows averaging 101 ± 16 days in milk at the beginning of the study were randomly assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each 21-d period consisted of a 14-d diet adaptation period and 7-d collection period. Cows were fed the following diets comprised total mixed rations based on grass silage with forage to concentrate (FC) ratio of 35:65 and 65:35 containing 0 or 50 g/kg of RO. Significant FC × RO interactions were observed for milk yield, milk protein and lactose yields, milk fat concentration, and milk proportions of trans-11 18:1, trans-10 18:1, trans-10, cis-12 18:2, and saturated FA. Feeding low-forage diet was effective in increasing milk yield compared with the high-forage diet, and the RO supplementation increased it further (P ≤ 0.01). A similar pattern was observed for the yields of milk protein and lactose. Supplementing the low-forage diet with RO reduced milk fat concentration by 19% relative to other diets without affecting milk fat yield. The proportion of N intake lost as urine decreased (P ≤ 0.05) with the RO supplementation of low-forage diet without affecting energy and N balances. Nutrient intakes were greater (P ≤ 0.01) in cows fed low-forage diet, whereas RO decreased (P < 0.05) protein, starch, and fiber intakes. Methane production, expressed as a proportion of energy intake, decreased with low-forage compared with high-forage diets and this variable declined similarly by RO supplementation of both diets (P < 0.01). The milk proportions of trans-10 18:1 and trans-10, cis-12 CLA increased (P ≤ 0.01) by RO supplementation of the low-forage but not high-forage diet. However, RO supplementation of both high- and low-forage diets increased (P < 0.01) total trans FA and decreased saturated FA proportions, even though the changes were more profound in low-forage diet (P ≤ 0.01). In addition, RO increased (P < 0.01) cis monounsaturated FA in milk for both high- and low-forage diets. Overall, the low-forage diets had lower methane emissions and RO increased partitioning of N towards milk secretion (P ≤ 0.01) without influencing energy or N balances. According to the results, RO supplementation did not compromise intake of nutrients with low-forage diets containing 150 g/kg starch, and oil could be preferentially used to improve milk production and milk fat quality accompanied by a reduction in methane energy loss

    Fault-Tolerant Exact State Transmission

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    We show that a category of one-dimensional XY-type models may enable high-fidelity quantum state transmissions, regardless of details of coupling configurations. This observation leads to a fault- tolerant design of a state transmission setup. The setup is fault-tolerant, with specified thresholds, against engineering failures of coupling configurations, fabrication imperfections or defects, and even time-dependent noises. We propose the implementation of the fault-tolerant scheme using hard-core bosons in one-dimensional optical lattices.Comment: 5 pages and 4 figure
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