Using specific histamine H1 and H2 receptor antagonists, evidence is presented for the existence of both H1 and H2 receptors on human articular chondrocytes in vitro. Stimulation of the H1 receptor by histamine (range 0.18 to 17.8 mumol/l) significantly increased prostaglandin E (PGE) production, while activation of the histamine H2 receptor increased intracellular cyclic adenosine-5'-monophosp...

Late spring frost is one of the most important factors causing loss of production of the Persian walnut (Juglans regia L.). Therefore, the selection of spring frost tolerant genotypes has been among the most important priorities in the breeding programs during the recent years in Horticultural Science Research Institute, Karaj-Iran.  After the spring frost in 2010, five superior genotypes (B10,...

Several RNases H1 cleave the RNA-DNA junction of Okazaki fragment-like RNA-DNA/DNA substrate. This activity, termed 3'-junction ribonuclease (3'-JRNase) activity, is different from the 5'-JRNase activity of RNase H2 that cleaves the 5'-side of the ribonucleotide of the RNA-DNA junction and is required to initiate the ribonucleotide excision repair pathway. To examine whether RNase H1 exhibits 3...

Six clinically healthy male water buffaloes (Bubalus bubalis) 2-3 years of age and weighing 290-325 kg were used for 2 different treatments (H1 and H2). The animals of group H1 were premedicated with medetomidine (2.5 g/kg,i.v.) and butorphanol (0.05 mg/kg, i.v.), while in group H2 midazolam (0.25 mg/kg) and butorphanol (0.05 mg/kg) were used intravenously. Induction of anaesthesia was achieved...

The effects of synchronous photo (16 h daylength) and thermo (2 degrees C daily fluctuation) cycles on flowering time were compared with constant light and temperature treatments using two barley mapping populations derived from the facultative cultivar 'Dicktoo'. The 'Dicktoo'x'Morex' (spring) population (DM) segregates for functional differences in alleles of candidate genes for VRN-H1, VRN-H...

Let A = ( H1 E ∗ E H2 ) and à = ( H1 O O H2 ) be Hermitian matrices with eigenvalues λ1 ≥ · · · ≥ λk and λ̃1 ≥ · · · ≥ λ̃k, respectively. Denote by ‖E‖ the spectral norm of the matrix E, and η the spectral gap between the spectra of H1 and H2. It is shown that |λi − λ̃i| ≤ 2‖E‖ η + √ η2 + 4‖E‖2 , which improves all the existing results. Similar bounds are obtained for singular values of matrices u...

We review some existing results on H2 and H1 estimation and explore possible connections between the optimal algorithms. For instance, in order to relate the H2 optimal Kalman lter to the H1 lters we show that, with special choices of the covariance matrices, the Kalman lter is H1 optimal. Moreover, by studying the matrix operator relating the estimation errors and the disturbances, we obtain s...

Let k ≥ 4, and let H1, H2 be connected graphs with |V (Hi)| ≥ 3 for i = 1, 2. A graph G is said to be {H1, . . . , Hl}-free if none of H1, . . . , Hl is an induced subgraph of G. We prove that if there exists a positive integer n0 such that every {H1, H2}-free graph G with |V (G)| ≥ n0 and δ(G) ≥ 3 contains k vertex-disjoint claws, then {H1, H2} ∩ {K1,t | t ≥ 2} = ∅. Also, we prove that every K...

The contributions of histamine (H1 or H2) receptor-mediated responses and, therefore, the effects of histamine blocking agents are unclear with regard to regulation of proximal epicardial and distal resistance coronary arteries. This study was designed to evaluate the effects of selective H1- and H2-receptor antagonists on epicardial and resistance vessels in the closed chest dog model. Histami...