Cone myoid elongation and rod myoid contraction are inhibited by colchicine in the trout retina

Summary Retinal photoreceptors of lower vertebrates undergo photomechanical changes (elongation or shortening) in response to light or dark. Colchicine, a microtubule-disrupting drug, blocks cone, but not rod elongation. Instead, rod shortening is blocked by this drug, thus suggesting that different mechanisms mediating these responses are involved in rods and cones.Acknowledgments. This work was supported by a grant from the Quebec Ministry of Education (FCAC). We thank Carole Marullo for technical assistance.     

Ankyrin-B mutation causes type 4 long-QT cardiac arrhythmia and sudden cardiac death

Mutations in ion channels involved in the generation and termination of action potentials constitute a family of molecular defects that underlie fatal cardiac arrhythmias in inherited long-QT syndrome. We report here that a loss-of-function (E1425G) mutation in ankyrin-B (also known as ankyrin 2), a member of a family of versatile membrane adapters, causes dominantly inherited type 4 long-QT cardiac arrhythmia in humans. Mice heterozygous for a null mutation in ankyrin-B are haploinsufficient and display arrhythmia similar to humans. Mutation of ankyrin-B results in disruption in the cellular organization of the sodium pump, the sodium/calcium exchanger, and inositol-1,4,5-trisphosphate receptors (all ankyrin-B-binding proteins), which reduces the targeting of these proteins to the transverse tubules as well as reducing overall protein level. Ankyrin-B mutation also leads to altered Ca2+ signalling in adult cardiomyocytes that results in extrasystoles, and provides a rationale for the arrhythmia. Thus, we identify a new mechanism for cardiac arrhythmia due to abnormal coordination of multiple functionally related ion channels and transporters.     

Sperm from neonatal mammalian testes grafted in mice

Spermatogenesis is a productive and highly organized process that generates virtually unlimited numbers of sperm during adulthood. Continuous proliferation and differentiation of germ cells occur in a delicate balance with other testicular compartments, especially the supporting Sertoli cells. Many complex aspects of testis function in humans and large animals have remained elusive because of a lack of suitable in vitro or in vivo models. Germ cell transplantation has produced complete donor-derived spermatogenesis in rodents but not in other mammalian species. Production of sperm in grafted tissue from immature mammalian testes and across species has not yet been accomplished. Here we report the establishment of complete spermatogenesis by grafting testis tissue from newborn mice, pigs or goats into mouse hosts. This approach maintains structural integrity and provides the accessibility that is essential for studying and manipulating the function of testes and for preserving the male germ line. Our results indicate that this approach is applicable to diverse mammalian species.     

一种多特征综合的实时调度算法

随着科学技术的发展，在国民经济的各个领域中，实时调度算法有着广泛的应用，如交通管制、敏捷制造和电子商务等．实时调度算法主要包括：速度单调算法RM(Rate Monotonic)、截止期最早优先算法EDF(Earliest Deadline First)、最小裕度算法LSF(Least Slack First)、最高价值优先算法HVF(Highest Value First)、     

Do prostaglandins mediate the somatostatin preventive effect on gastric lesion?

The inhibition of endogenous prostaglandin synthesis by indomethacin treatment blocks the somatostatin preventive effect on the gastric lesions induced in a stress model and has no preventive effect on an intragastric distension model.     

Coupling of Thermal-Hydraulic-Mechanical Processes for Geothermal Reservoir Modelling

This paper uses a fully coupled framework of thermal-hydraulic-mechanical processes to investigate how the injection and extraction of fluid within a geothermal reservoir impacts on the dis-tributions ...     

Evolution of several soil properties following amendment with olive mill wastewater

Occurrences of olive mill wastewater (OMW) amendment on several chemical and biochemical properties of soil were investigated. Compared to the control, soils amended with untreated and treated OMW (by an integrated process based on aerobic fungal pre-treatment using Phanerochaete chrysosporium DSMZ 6909 followed by anaerobic treatment) showed high levels of organic and mineral matters. Soil amended with untreated OMW presented low levels of total and inorganic nitrogen (0.38 and 0.08 mg g⁻¹ dry soil). Treated OMW contained little content of pollutants (COD = 4 g l⁻¹; phenolic compounds = 0.6 g l⁻¹); so, organic matter brought by these residues was rapidly mineralized in the soil. The number of heterotrophic bacteria was increased (from 54 × 10⁵ CFU g⁻¹ dry soil in control soil to 123 × 10⁵ CFU g⁻¹ dry soil) in response to the OMW amendment, mainly after C/N ratio correction. Untreated OMW application improved the soil carbon content (2.18 times higher), while the specific respiration remained very low. However, the treated OMW application positively affected the soil-specific respiration that increased from 6.1 in control soil to 9.75 in soil amended with treated OMW. This phenomenon was accompanied by an enhancement of nitrifiers number, urease and ammonium oxidases activities.     

The Complex Dynamics of Hepatitis B Infected Individuals with Optimal Control

This paper proposes various stages of the hepatitis B virus(HBV) besides its transmissibility and nonlinear incidence rate to develop an epidemic model. The authors plan the model, and then prove some basic results for the well-posedness in term of boundedness and positivity. Moreover, the authors find the threshold parameter R0, called the basic/effective reproductive number and carry out local sensitive analysis. Furthermore, the authors examine stability and hence condition for stability in terms of R0. By using sensitivity analysis, the authors formulate a control problem in order to eradicate HBV from the population and proved that the control problem actually exists. The complete characterization of the optimum system was achieved by using the 4~(th)-order Runge-Kutta procedure.     

Optimization of cultural conditions for thermostable β-1,3-1,4-glucanase production by Bacillus subtilis ZJF-IA5

The optimization of cultural conditions for β-glucanase production by Bacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on β-glucanasc production which maximized atoptimal temperature of 37℃ and decreased significantly when temperature was over 37℃ . Charge quantity affected β-glucanasc production significantly. Adding oxygen vector N-dodecanc or acetic ether benefited β-glucanasc production, but it depended on the concentration and charge quantity. The results of fractional factorialdesign showed that age and size of inoculum and shaking speed were the key factors affecting β-glueanase production and the cultivation time span to reach the highest β-glucanasc activity. The optimal cultural conditionsfor p-glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82% (v/v)),shaking speed 210 r/rain, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37℃ for 50 h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of p-glucanase, a-amylase and neutral protease produced by B subtills ZJF-1A5 was associated partially with cell growth. Those three enzymes‘ activities increased following the cell growth and increased signifi-cantly when cells entered the stationary phase.