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71.
 The vernalization gene Vrn-A1 on chromosome 5A is the predominant gene determining the spring/winter habit difference in bread wheat. Vrn-A1 was physically mapped using a set of deletion lines which located it to the region of chromosome 5A flanked by deletion breakpoints 0.68 and 0.78. This interval was shown to be homoeologous to a region of rice chromosome 3 that contains the flowering-time QTL Hd-6, previously mapped in a Nipponbare×Kasalath cross, and FLTQ1, a novel QTL identified by analysis of 78 F3 families derived from a cross of ‘IR20’ב63–83’. Possible relationships between Vrn-A1 and rice QTL are discussed. Analysis of the chromosome 5A deletion lines showed evidence for a second, more proximal flowering-time effect located between deletion breakpoints 0.56 and 0.64. The proximal part of chromosome 5A is homoeologous to rice chromosome 9, on which two QTL were detected in the ‘IR20ב63–83’ cross. The possible relationship between these effects is also discussed. Received: 23 December 1997 / Accepted: 12 January 1998  相似文献   
72.
A reliable callus regeneration and shoot multiplication system for wetland monocot Juncus accuminatus has been established. Callus was induced from 6-day-old seedlings on Murashige and Skoog medium supplemented with 5 mg/l picloram. The callus differentiated into shoots upon transfer to 5 mg/l benzyladenine (BA)-supplemented medium. Effects of medium pH (3.8–7.8) and source of callus (grown in the dark or continuous light) on regeneration were determined. Both parameters significantly influenced regeneration. Regenerated shoots were multiplied by subculturing shoots onto 5 mg/l BA medium at 4-week intervals. The regenerated shoots were rooted on 0.1 mg/l naphthaleneacetic-acid-supplemented medium. The rooted plants were transferred to pots containing a commercial potting mix and established in the greenhouse. Plants covered with plastic grew faster and flowered earlier than uncovered plants. All plants set viable seeds. Received: 21 July 1997 / Revision received: 23 December 1997 / Accepted: 19 January 1998  相似文献   
73.
A series of 2,5-diaryloxadiazole linked pyrrolo[2,1-c][1,4]benzodiazepine conjugates have been prepared and evaluated for their anticancer activity. These conjugates have shown promising activity with GI50 values ranging from <0.1 to 0.29 μΜ. It is observed that some of these conjugates particularly 4a, 4d, 4i and 4l exhibit significant anticancer activity. Some detailed biological assays relating to the cell cycle aspects associated to Bax and caspases have been examined with a view to understand the mechanism of action of these conjugates.  相似文献   
74.
75.
Recent advances in sequencing allow population‐genomic data to be generated for virtually any species. However, approaches to analyse such data lag behind the ability to generate it, particularly in nonmodel species. Linkage disequilibrium (LD, the nonrandom association of alleles from different loci) is a highly sensitive indicator of many evolutionary phenomena including chromosomal inversions, local adaptation and geographical structure. Here, we present linkage disequilibrium network analysis (LDna), which accesses information on LD shared between multiple loci genomewide. In LD networks, vertices represent loci, and connections between vertices represent the LD between them. We analysed such networks in two test cases: a new restriction‐site‐associated DNA sequence (RAD‐seq) data set for Anopheles baimaii, a Southeast Asian malaria vector; and a well‐characterized single nucleotide polymorphism (SNP) data set from 21 three‐spined stickleback individuals. In each case, we readily identified five distinct LD network clusters (single‐outlier clusters, SOCs), each comprising many loci connected by high LD. In A. baimaii, further population‐genetic analyses supported the inference that each SOC corresponds to a large inversion, consistent with previous cytological studies. For sticklebacks, we inferred that each SOC was associated with a distinct evolutionary phenomenon: two chromosomal inversions, local adaptation, population‐demographic history and geographic structure. LDna is thus a useful exploratory tool, able to give a global overview of LD associated with diverse evolutionary phenomena and identify loci potentially involved. LDna does not require a linkage map or reference genome, so it is applicable to any population‐genomic data set, making it especially valuable for nonmodel species.  相似文献   
76.
Lactobacillus acidophilus was used for the removal of As(III) from 50–2000 ppb As(III)-containing water solution. Biosorption of As(III) by L. acidophilus was dependent on concentration (50 to 2000 ppb) and time (0 to 3 h).L. acidophilus(1 mg dry wt/ml) was able to remove 30, 60, 300, 420, 600 ppb As(III) from 50, 100, 500, 1000, and 2000 ppb of As(III)-containing water solution, respectively, within 3 h at pH 7. Moreover, by increasing the biomass of L. acidophilus(2 mg dry wt/ml) removal of As(III) was enhanced 1.66, 1.33, 1.16, 1.42, and 1.33 times, respectively. Fourier transform infrared (FTIR) and electron spectroscopy for chemical analysis (ESCA) spectrum of As(III)-loaded biomass was also investigated. An FTIR sample spectrum of L. acidophilus fresh biomass and As(III)-loaded biomass showed band stretching of fresh and As(III)-loaded biomass for O-H, 3423.43 to 3385.04 cm?1, and for C-O, 1742.82 to 1731.14 cm?1, and signified that –OH and –CO groups were also involved in the removal of As(III) from As(III)-containing water solution.  相似文献   
77.
P. K. Sarma, A. K. Chowhan, V. Agrawal and V. Agarwal
Fine needle aspiration cytology in HIV‐related lymphadenopathy: experience at a single centre in north India Objective: Fine needle aspiration (FNA) is emerging as a rapid and minimally invasive tool in evaluating lymphadenopathy associated with human immunodeficiency virus (HIV). We evaluated the role of FNA in differentiating various causes of lymphadenopathy in patients with HIV and correlated the cytological diagnosis with CD4 counts. Methods: Seventy‐nine HIV‐positive patients (median age 35 years, 68 male) underwent ultrasound‐guided (n = 16) and unguided (n = 63) FNA from 1999 to 2006. Smears were stained with May–Grünwald–Giemsa, haematoxylin & eosin and Papanicolaou stains. Ziehl–Neelsen (ZN) staining for acid‐fast bacilli (AFB) was performed in all cases. Staining for fungus was performed whenever required. Results: The aspirates were adequate in 75 cases (95%). Non‐specific reactive hyperplasia was the most common FNA diagnosis (39, 52%) followed by granulomatous necrotizing lymphadenitis (15, 20%), necrotizing lymphadenitis (13, 17.3%) and granulomatous lymphadenitis (4, 5.2%). Fungal infection and non‐Hodgkin lymphoma (NHL) were seen in two patients each. ZN staining was positive for AFB in 25 (33.3%) cases. One of these was morphologically interpreted as reactive hyperplasia, 12 as necrotizing lymphadenitis and 12 as granulomatous necrotizing lymphadenitis. Both patients with NHL had CD4 counts below 100/dl. Necrotizing lymphadenitis and granulomatous lymphadenitis were significantly associated with CD4 counts below and above 200/dl, respectively (P = 0.0002). Conclusions: FNA is an important tool for assessing the cause of lymphadenopathy in HIV patients. Necrotizing inflammation is more often seen in patients with low CD4 counts. AFB are commonly found in necrotic aspirates with or without granulomas. However, a stain for AFB should be performed in all aspirates from HIV‐related lymphadenopathy including reactive hyperplasia.  相似文献   
78.
We studied the response of Brachionus patulus to different concentrations of the heavy metal Pb in the presence and absence of sediments. We conducted acute (LC50) and chronic (life table demography and population growth) toxicity tests using sediment levels of 0, 30 and 280 mg l−1 (=0, 17 and 170 NTU) and Pb at 0, 0.06 and 0.6 mg l−1. Experiments were conducted at 20 ± 1°C on a horizontal shaker and algal food (Chlorella vulgaris) was added at a density of 1.0 × 106 cells ml−1. The median lethal concentration (LC50 ± 95% Confidence intervals) of PbCl2 for B. patulus was 6.15 ± 1.08 mg l−1. Age-specific survivorship and fecundity curves showed increase in turbidity level resulted in decreased survival and offspring production of the rotifers. Increase in Pb concentration too had a negative effect on the survival and reproductive output of B. patulus. Statistically, average lifespan, life expectancy at birth, gross and net reproductive rates and the rate of population increase were all significantly influenced by the concentration of Pb, turbidity level as well as the interaction of Pb concentration × turbidity level. Rotifers exposed to 170 NTU did not grow regardless of the heavy metal concentration in the medium. Similarly, B. patulus exposed to 0.6 mg l−1 Pb did not survive beyond 10 days regardless of the turbidity level in the medium. The rate of population increase of B. patulus derived from the growth experiments was negative in all treatments containing Pb as low as 0.06 mg l−1 or turbidity level as low as 17 NTU. In treatments containing Pb or sediments, there existed no relation between the egg ratio and the population density. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont and R. Rico-Martínez Advances in Rotifer Research  相似文献   
79.
Heavy metals are widely recognized as potential toxic agents to zooplankton, yet experiments are usually performed with a continuous exposure to the metal being analyzed. Here we describe experiments that examined the influence of pulsed exposure of the heavy metals copper and cadmium to a parthenogenetic population of the planktonic rotifer Brachionus calyciflorus. Our protocol called for exposure durations of 3, 6, 12, and 24 h to either copper (as CuSO4) at concentrations of 0.0375, 0.075, 0.15 mg l−1 or cadmium (as CdCl2) at concentration of 0.025, 0.05, 0.1 mg l−1. Control animals were treated in similar ways but did not receive exposure to heavy metals. Four end points were used to evaluate the outcome of exposure: population growth (r), body size, egg ratio, and egg hatching percent. Increase in heavy metal concentration and exposure time had an adverse influence on the population growth of B. calyciflorus. However, while the response of B. calyciflorus was similar for both heavy metals, the magnitude of the impact of cadmium was more severe. Population growth varied depending on which heavy metal was tested, as well as its concentration and the duration of exposure (r = 0.11–0.28 day−1). There was a significant reduction in lorica size of B. calyciflorus subjected to different exposure times and concentrations of both Cd and Cu. Egg ratios were inversely related to population density in controls and in treatments involving Cu, but not for Cd. While nearly 100% of eggs hatched in the control treatments, egg hatching in experimental treatments containing Cu, were reduced (range = 16–41%) depending on the exposure time and the concentration. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont & R. Rico-Martínez Advances in Rotifer Research  相似文献   
80.
Influence of recirculation on the performance of anaerobic sequencing batch biofilm reactor (AnSBBR) was studied in the process of treating hypersaline (total dissolved inorganic solids (TDIS) approximately 26 g/l) and low biodegradable (BOD/COD approximately 0.3) composite chemical wastewater. Significant enhancement in the substrate removal efficiency and biogas yield was observed after introducing the recirculation to the system. Maximum efficiency (COD removal efficiency - 51%; SDR - 3.14 kg COD/cum-day) was observed at recirculation to feed (R/F) ratio of 2 (OLR - 6.15 kg C OD/cum-day; HLR - 2.30 cum (liquid)/cum day; UFV(A) - 0.023 m/h). Subsequent increase of R/F to 3 (OLR - 6.15 kg COD/cum-day; HLR - 3.07cum (liquid)/cum-day; UFV(A) - 0.035 m/h) resulted in reduction in COD removal efficiency (32%; SDR - 1.97 kg COD/cum-day). The enhanced performance of the system due to the introduction of recirculation was attributed to the improvement in the mass transfer between the substrate present in the bulk liquid and the attached biofilm. The hydrodynamic behavior due to recirculation mode of operation reduced the concentration gradient (substrate inhibition) of substrate and reaction by-products (VFA) resulting in mixed flow conditions.  相似文献   
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