Wyniki wyszukiwania - Biblioteka Nauki

1

Anti-synchronization in different new chaotic systems via active nonlinear control

100%

Khan A. , Prasad R. P.

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tom Vol. 23, no. 2

229-242

EN

In this paper, we discuss anti-synchronization between two identical new chaotic systems and anti-synchronization between another two identical new chaotic systems by active nonlinear control. The sufficient conditions for achieving the anti-synchronization of two new chaotic systems are derived based on Lyapunov stability theory. Numerical simulations are provided for illustration and verification of the proposed method.

2

Regularization of non-coercive quasi variational inequalities

100%

Giannessi F. , Khan A.

Control and Cybernetics

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2000

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tom Vol. 29, no 1

91-110

EN

This paper is devoted to the regularization of quasi-variational inequalities. The quasi-variational inequality is considered with multivalued operator. The operator involved is taken to be non-coercive and the data are assumed to be known approximately only. Under the assumption that the quasi-variational inequality be solvable, a weakly convergent approximation procedure is designed by means of the so-called Browder-Tikhonov regularization method.

3

Kelvin - Helmholtz instability of two superposed Oldroydian viscoelastic fluid layers in a horizontal magnetic field

80%

Khan A. , Tak S. S. , Patni P.

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tom Vol. 15, no 4

1129-1142

EN

The Kelvin-Helmholtz instability of the plane interface separating two superposed viscous electrically conducting streaming Oldroydian fluids permeated with surface tension and magnetic field in a porous medium is considered. The stability motion is also assumed to have uniform two dimensional streaming velocity. The stability analysis has been carried out for two highly viscous fluids. By applying the normal mode technique to the linearized perturbation equations, the dispersion relation has been derived. As in the case of superposed Newtonian fluids, the system is stable in the potentially stable case and unstable in the potentially unstable case, that holds also for the present case. The behavior of growth rate with respect to kinematic viscosity, elasticity, permeability of porous medium, surface tension and streaming velocity are examined numerically and discussed in detail in section 5.

4

Rayleigh waves speed in transversely isotropic material

80%

Rehman A. , Khan A. , Ali A.

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tom Vol. 54, iss. 4

323-328

EN

Rayleigh wave speed in transversely isotropic material is studied. A very simple technique is adopted to solve the secular equation. Speed in some transversely isotropic materials is calculated.

5

The interaction of metal nanoparticles (copper, silver, platinum, and gold) with cell line HS-5

80%

Lange A. , Jaworski S. , Khan A.

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nr 3

6

Disrupted brain thyroid hormone homeostasis and altered thyroid hormone-dependent brain gene expression in autism spectrum disorders

80%

Khan A. , Harney J. W. , Zavacki A. M. , Sajdel-Sulkowska E. M.

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nr 2

7

Sex-dependent changes in cerebellar thyroid hormone-dependent gene expression following perinatal exposure to thimerosal in rats

71%

Khan A. , Sulkowski Z. L. , Chen T. , Zavacki A. M. , Sajdel-Sulkowska E. M.

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nr 3

8

Calcium chloride and gibberellic acid protect linseed (Linum usitatissimum L.) from NaCl stress by inducing antioxidative defence system and osmoprotectant accumulation

61%

Khan M. N. , Siddiqui M. H. , Mohammad F. , Naeem M. , Masroor M. , Khan A.

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nr 1

EN

Salinity stress affects many metabolic facets of plants and induces anatomical and morphological changes resulting in reduced growth and productivity. To overcome the damaging effects of salinity, different strategies of the application of nutrients with plant hormones are being adopted. The present study was carried out with an aim to find out whether application of calcium chloride (CaCl₂) and gibberellic acid (GA₃) could alleviate the detrimental effects of salinity stress on plant metabolism. Fifteen days old plants were supplied with (1) 0 mM NaCl + 0 mg CaCl₂ kg⁻¹ sand + 0 M GA₃ (control, T0); (2) 0 mM NaCl + 10 mg CaCl₂ kg⁻¹ sand + 0 M GA₃ (T1); (3) 0 mM NaCl + 0 mg CaCl₂ kg⁻¹ sand + 10⁻⁶ M GA₃ (T2); (4) 150 mM NaCl + 0 mg CaCl₂ kg⁻¹ sand + 0 M GA₃ (T3); (5) 150 mM NaCl + 10 mg CaCl₂ kg⁻¹ sand + 0 M GA₃ (T4); (6) 150 mM NaCl + 0 mg CaCl₂ kg⁻¹ sand + 10⁻⁶ M GA₃ (T5); (7) 150 mM NaCl + 10 mg CaCl₂ kg⁻¹ sand + 10⁻⁶ M GA₃ (T6). To assess the response of the crop to NaCl, CaCl₂ and GA₃, plants were uprooted randomly at 60 days after sowing. The presence of NaCl in the growth medium decreased all the growth and physio-biochemical parameters, except electrolyte leakage, proline (Pro) and glycine betaine (GB) content, thiobarbituric acid reactive substances (TBARS), H₂O₂ content, activities of superoxide dismutase (SOD) and catalase (CAT) and leaf Na content, which exhibited an increase of 37.6, 29.3, 366.9, 107.5, 59.1, 17.1, 28.4 and 255.2%, respectively, compared to the control plants. However, application of CaCl₂ in combination with GA₃ appears to confer greater osmoprotection by the additive role with NaCl in Pro and GB accumulation. Although the activities of antioxidant enzymes (SOD, CAT and POX) were increased by salt stress, the combined application of CaCl₂ and GA₃ to salt-stressed plants further enhanced the activities of these enzymes by 25.1, 6.7 and 47.8%, respectively, compared to plants grown with NaCl alone. The present study showed that application of CaCl₂ and GA₃ alone as well as in combination mitigated the adverse effect of salinity, but combined application of these treatments proved more effective in alleviating the adverse effects of NaCl stress.

9

Retrospective study of cystic echinococcosis (CE) based on hospital record from five major metropolitan cities of Pakistan

61%

Muqaddas H. , Arshad M. , Ahmed H. , Mehmood N. , Khan A. , Simsek S.

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nr 4

10

Increase in the effectiveness of somatodendritic 5-HT-1A receptors in a rat model of tardive dyskinesia

61%

Samad N. , Khan A. , Perveen T. , Haider S. , Haleem M. A. , Haleem D. J.

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tom 67

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nr 4

EN

The present study concerns responsiveness of pre- and postsynaptic 5-hydroxytryptamine (5-HT)-1A receptors in a rat model of tardive dyskinesia (TD). Vacuous chewing movements (VCMs) in rats are widely accepted as an animal model of TD. Results show that haloperidol injected at a dose of 1 mg/kg twice a day for 5 weeks elicited VCMs, which increased in a time dependent manner following the drug administration for 3Ė5 weeks. Tolerance was produced in motor coordination during the potentiation of VCMs. Exploratory activity in an open field and in an activity box decreased in haloperidol treated animals. The effects of 8-hydroxy-2-(di-n-propylamino)tetraline (8-OH-DPAT; 0.5 mg/kg) were monitored 48-h after withdrawal from repeated administration of haloperidol. 8-OH-DPAT-induced locomotion was greater in haloperidol treated rats. 5-HT synthesis increased in haloperidol treated animals, while 8-OH-DPAT-induced decreases of 5-HT synthesis were greater in repeated haloperidol than repeated saline injected animals. The results suggest that an increase in the effectiveness of somatodendritic 5-HT-1A receptors may decrease the inhibitory influence of 5-HT on the activity of dopaminergic neurons to precipitate VCMs. The 5-HT-1A agonist may help to alleviate neuroleptic-induced TD.

11

Characterizing microbial populations in petroleum-contaminated soils of Swat district, Pakistan

51%

Uddin M. N. , Ali M. , Muhammad M. , Farooq M. , Ahmad N. , Jamil J. , Kalsoom J. J. , Adnan M. , Shah N. , Khan A.

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2016

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tom 25

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nr 4

EN

Soil samples from petroleum-contaminated soil were collected from 25 different petroleum filling stations and automobile workshops in the district of Swat, Khyber Pakhtunkhawa, Pakistan. A total of seven bacterial genera were isolated. All of the isolates were Gram-positive bacteria. The genera identified by the culture and cell morphological characteristics were: Bacillus, Streptococcus, Staphylococcus, Micrococcus, Corynebacterium Arthrobacter, and Streptomyces. Lipolytic and saline activities of the selected isolates were studied. Among the isolates, Arthrobacter, Staphylococcus, Bacillus, Micrococcus, Corynebacterium, and Streptomyces produced lipase enzymes, while no lipase was produced by Streptococcus. Dense growth of Bacillus and Streptococcus was observed at 1% NaCl. Dense growth of Streptomyces was observed at strength of 2% NaCl. At 3% NaCl concentration, dense growth of Staphylococcus, Micrococcus, Corynebacterium, and Arthrobacter was observed, indicating that they were moderately halotolerent. In our study, Bacillus, Arthrobacter, and Streptomyces showed optimum growth at pH 8.0, and Streptococcus, Staphylococcus, and Micrococcus showed optimum growth at pH 7.0. Only Corynebacterium showed optimum growth at pH 9.0, indicating that it is tolerant of higher pH conditions.

12

Different tolerance of photosynthetic apparatus to Cd stress in two rice cultivars with the same leaf Cd accumulation

51%

Chen Y.-E. , Mao H.-T. , Wu N. , Khan A. , Din A. M. U. , Ding C.-B. , Zhang Z.-W. , Yuan S. , Yuan M.

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nr 12

EN

In plants, cadmium (Cd) is regarded as one of the most toxic metals and affects many physiological and biochemical processes. To investigate the effects of Cd on photosynthesis and antioxidant system of japonica and indica rice cultivars, Wuyu 21 (WY21) and IIyou 808 (IIY808) seedlings were exposed to different concentrations of Cd for 7 days. Our results indicated that Cd treatments resulted in the significant decrease in photosynthetic capacity and the obvious oxidative damage in WY21 and IIY808. Although Cd contents in the leaves and stem had no obvious difference between WY21 and IIY808 under Cd stress, japonica cultivar WY21 showed higher Cd contents of roots and photosynthetic efficiency compared with indica cultivar IIY808 under Cd stress. In contrast, the lower generation of reactive oxygen species (ROS) and cell death were observed in WY21 relative to IIY808. However, almost all antioxidant enzymes activities and the concentrations of four antioxidants showed no significant differences between WY21 and IIY808. Furthermore, the severe oxidative damage in IIY808 was accompanied by the marked decline in the levels of two photosystem II (PSII) proteins (D2 and D1) under high concentration of Cd. In conclusion, we concluded that high Cd resistance in japonica cultivar WY21 is probably attributed to the high photosynthesis under Cd stress.

13

Quantitative determination of lethal concentration Lc50 of atrazine on biochemical parameters; total protein and serum albumin of freshwater fish grass carp (Ctenopharyngodon idella)

51%

Khan A. , Shah S. , Muhammad N. , Khan M. S. , Ahmad M. S. , Farooq M. , Adnan M. , Jawad S. M. , Ullah H. , Yousafzai A. M.

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2016

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tom 25

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nr 4

EN

The indiscriminate use of herbicides has led to the contamination of water bodies, possibly affecting the health of aquatic biota, especially fish. Atrazine is considered as toxicants for aquatic fauna, due to its high persistence in soil, high half-life and high mobility toward aquatic bodies as well as high solubility in water. The objective of the present study was to determine (LC50) and to evaluate the acute and chronic toxicity of atrazine on the biochemical parameters; total protein and serum albumin of freshwater grass carp (Ctenopharyngodon idella). Above 15 μlL⁻¹, the LC50 was recorded revealing sensitivity of grass carp to atrazine. Grass carp was exposed to atrazine for 01 (15 μlL⁻¹), 02 (13 μlL⁻¹), 03 (10 μlL⁻¹), and 04 (08 μlL⁻¹) days/concentration for scrutinizing acute toxicity. Likewise, fish were exposed to atrazine for 10 (06 μlL⁻¹), 15 (04 μlL⁻¹), and 25 (02 μlL⁻¹) days/concentration for scrutinizing chronic toxicity. Control group concentration was 8.3 gL⁻¹ and 3.5 gL⁻¹. Total protein concentration observed for acute toxicity was 7.5 gL⁻¹, 6.5 gL⁻¹, 4.6 gL⁻¹, and 3.2 g/L and serum albumin concentration was 2.7 gL⁻¹, 1.6 gL⁻¹, 1.4 gL⁻¹, and 1.1 gL⁻¹ respectively. Similarly total protein concentration observed for chronic toxicity was 8.2 gL⁻¹, 6.8 gL⁻¹, and 4.3 gL⁻¹ and serum albumin concentration was 2.1 gL⁻¹, 1.7 gL⁻¹, and 1.4 gL⁻¹ respectively. Markedly decline (denoted by P<0.05, P≤0.01 and P≤0.001) was noticed in both the parameters concentration during acute as well as chronic toxicity, when compared with control group concentration, indicating negatively impinge of atrazine on grass carp as well as atrazine present in aquatic bodies must jeopardize the health of other aquatic fauna.

14

Screening for genetic mutations in LDLR gene with familial hypercholesterolemia patients in the Saudi population

51%

Alharbi K. K. , Kashour T. S. , Al-Hussaini W. , Nbaheen M. , Hasanato R. M. W. , Mohamed S. , Tamimi W. , Khan A.

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nr 3

15

Effect of heavy metal pollution on mineral absorption in sunflower (Helianthus annuus L.) hybrids

51%

Aslam U. , Ahmad I. , Hussain M. , Khan A. , Ghani A. , Mustafa I. , Jalal S. , Aqeel M. A. , Asif S. , Ahmed H.

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nr 01

EN

The present study was conducted in a potted experiment to examine the effects of chromium pollution on absorption of mineral nutrients and some morphophysiological attributes of two sunflower (Helianthus annuus L.) hybrids (FH-331 and FH-259) in the presence and absence of ethylene diamine tetra acetic acid (EDTA) used as a chelating agent. Four concentrations of chromium (Cr³⁺) i.e., 0, 20, 30 and 40 mg kg⁻¹ with and without 0.3 g kg⁻¹ , EDTA as chelating agent were applied to 25-day-old sunflower plants. A gradually decreasing trend in absorption of all minerals and other parameters studied were observed. Different treatments of Cr³⁺ as well as Cr³⁺ and EDTA significantly reduced root and shoot fresh weight; however, root, shoot and achene Cr³⁺ contents of two sunflowers hybrids under higher chromium and EDTA stress varied significantly whereas movement of Cr³⁺ contents to leaves was non-significant. Absorption of Na⁺, K⁺, N₂ and P through roots and shoots significantly reduced with increasing concentration of Cr³⁺ treatments. In fact addition of EDTA to the medium further enhanced the toxicity of chromium.

16

Enzymatic profile aactivity of grass carp (Ctenopharyngodon idella) after exposure to the pollutant named atrazine (herbicide)

51%

Khan A. , Yousafzai A. M. , Shah N. , Muhammad , Ahmad M. S. , Farooq M. , Aziz F. , Adnan M. , Rizwan M. , Jawad S. M.

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2016

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tom 25

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nr 5

EN

The present study contemplates the enzymatic profile of grass carp, including lactate dehydrogenase (LDH), creatinine phosphokinases (CPK), serum glutamic-pyruvic transaminase (SGPT), and alkaline phosphatase (Alk Phosp) under atrazine’s acute toxicity effects (LC50) for 01 (15 μl/L), 02 (13 μl/L), 03 (10 μl/L), and 04 (08 μl/L) days/concentration, respectively. For analyzing the enzymatic profile we followed the biochemical analyzer set protocol (Merck micro lab 300 biochemistry analyzer) in the laboratory. Control group concentrations for LDH, CPK, SGPT, and Alk Phosp were 342 IU/ml, 7513.3 IU/ml, 46 mmol/l, and 126.6 IU/ml, respectively. After treatment LDH concentrations were 906, 851, 765, and 545 IU/ml, respectively. CPK concentrations were 1,737, 2,445, 3,718, and 5,767 IU/ml, respectively. SGPT concentrations were 27, 24.3, 13.67, and 8.67, respectively, and Alk Phosp concentrations were 50.3, 30, 22.3, and 17.6 IU/ml, respectively. Maximum inclined (P≤0.001) in concentration of LDH was observed after 24 hrs exposure because of hepatic tissue damage, resulting in increased membrane permeability causing enhanced leaching out of LDH and as LDH participates in an anaerobic pathway, so increase LDH mean increases of anaerobic metabolism resulting from depletion of energy under environmental stress conditions by atrazine, while other enzymatic components like CPK, SGPT, and Alk Phosp showed kindred attributes in their result, like all parameter concentrations showed perpetual decline (P≤0.001) in their concentrations indicating reduced enzymatic activity due to a reduction in permeability for these enzymes, forcing the enzymes to accumulate in the cells as well as decrease in enzyme synthesis due to intoxication of atrazine.

17

Risk factors for outbreaks caused by variant strain of Newcastle disease on environmentally controlled broiler chicken farms in Lahore, Pakistan

50%

Maqsood R. , Khan A. , Mushtaq M. H. , Yaqub T. , Aslam M. A. , Rashid H. B. , Gill S. S. , Akram R. , Rehman A. , Chaudhry M. , Maqsood R. , Khan A. , Mushtaq M. H. , Yaqub T. , Aslam M. A. , Rashid H. B. , Gill S. S. , Akram R. , Rehman A. , Chaudhry M.

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nr 4

18

Microbiological safety and antibiogram analysis of selected food products obtained in the marketplace of Peshawar and Mardan, KPK, Pakistan

41%

Khan H. , Ullah S. , Salman M. , Hussain F. , Anwar Y. , Ullah I. , Khan I. A. , Hussain H. , Naeem I. , Khan A. , Khan H. , Jan F. , Shuaib M.

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tom 28

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nr 6

19

Mechanism of insecticide resistance in insects/pests

41%

Khan S. , Uddin N. , Rizwan M. , Khan W. , Farooq M. , Shah A. S. , Subhan F. , Aziz F. , Rahman K. U. , Khan A. , Ali S. , Muhammad M.

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nr 3