Key to the management of the Western Himalayan Hillstreams in relation to

A key to the management of hillstreams in relation to Fish Species Richness (FSR) and Shannon and Weaver Diversity Index (H) (Shannon and Weaver, 1949. The Mathematical Theory of Communications. Urbana, University of Illinois Press, IL, USA) using a multitude of factors such as altitude, water source, bed gradient, dominant channel materials and habitat type has been proposed on the basis of 10 study sites, belonging to three north Indian rivers namely; Ghaggar, Yamuna and Ganga. The selected streams are located between the altitudes ranging from 380 to 1524m. It has been observed that high altitude streams having steep gradient, boulder dominated substrate with rapids as the main habitat type had lower FSR (3–4) and H (0.55–0.99) as compared to hillstreams located in the lower altitudes having gentle gradient, cobble dominated substrate with pools, riffles, runs, rapids and cascades as the main habitats and have high FSR (6–14) and H (1.67–2.35). Types – A, B and F hillstreams were encountered when the hillstreams are classified after Rosgen (Applied River Morphology, Wildland Hydrology, Co, USA).     

Key to the management of the Western Himalayan Hillstreams in relation to

A key to the management of hillstreams in relation to Fish Species Richness (FSR) and Shannon and Weaver Diversity Index (H) (Shannon and Weaver, 1949. The Mathematical Theory of Communications. Urbana, University of Illinois Press, IL, USA) using a multitude of factors such as altitude, water source, bed gradient, dominant channel materials and habitat type has been proposed on the basis of 10 study sites, belonging to three north Indian rivers namely; Ghaggar, Yamuna and Ganga. The selected streams are located between the altitudes ranging from 380 to 1524m. It has been observed that high altitude streams having steep gradient, boulder dominated substrate with rapids as the main habitat type had lower FSR (3–4) and H (0.55–0.99) as compared to hillstreams located in the lower altitudes having gentle gradient, cobble dominated substrate with pools, riffles, runs, rapids and cascades as the main habitats and have high FSR (6–14) and H (1.67–2.35). Types – A, B and F hillstreams were encountered when the hillstreams are classified after Rosgen (Applied River Morphology, Wildland Hydrology, Co, USA).     

Commitment to the mitotic cell cycle in yeast in relation to meiosis

Under restrictive vegetative conditions, cells of cell-division cycle (cdc) temperature-sensitive mutants arrest at specific points in the cycle. Meiotic and mitotic behaviour of such arrested cells was examined under permissive sporulation conditions. Those mutants which were committed to mitosis at their specific point of arrest finished the cell cycle and could only then go into meiosis. It was found that commitment to mitosis occurred early in the cell cycle, prior to DNA replication, and that this commitment was dependent upon the gene function of cdc4.     

Persistence to anti-cancer treatments in the stationary to proliferating transition

The heterogeneous responses of clonal cancer cells to treatment is understood to be caused by several factors, including stochasticity, cell-cycle dynamics, and different micro-environments. In a tumor, cancer cells may encounter fluctuating conditions and transit from a stationary culture to a proliferating state, for example this may occur following treatment. Here, we undertake a quantitative evaluation of the response of single cancerous lymphoblasts (L1210 cells) to various treatments administered during this transition. Additionally, we developed an experimental system, a “Mammalian Mother Machine,” that tracks the fate of thousands of mammalian cells over several generations under transient exposure to chemotherapeutic drugs. Using our developed system, we were able to follow the same cell under repeated treatments and continuously track many generations. We found that the dynamics of the transition between stationary and proliferative states are highly variable and affect the response to drug treatment. Using cell-cycle markers, we were able to isolate a subpopulation of persister cells with distinctly higher than average survival probability. The higher survival rate encountered with cell-cycle phase specific drugs was associated with a significantly longer time-till-division, and was reduced by a non cell-cycle specific drug. Our results suggest that the variability of transition times from the stationary to the proliferating state may be an obstacle hampering the effectiveness of drugs and should be taken into account when designing treatment regimens.     

Some remarks to the Sterba's Fluorescent method in application to the neurosecretory cells

Summary When staining the neurosecretory cells with N,N-diethylpseudoisocyanine chloride according to Sterba fluorescence of nucleolus and structures in the peripheral zone of the cytoplasm was observed simultaneously with the fluorescence of the neurosecretory granules. Preliminary treatment of sections with ribonuclease made it possible to obtain preparations in which only neurosecretory granules fluoresce in the neurosecretory cells. It proves that the secondary fluorescence of the peripheral structures is due to the ribonucleic acid they contain, and the structures themselves are Nissl's substance. The intensity of the secondary fluorescence of the neurosecretory substance and the Nissl's substance changes when embedding sections stained with N,N-diethylpseudoisocyanine chloride in media with different pH values (from 2.6–8.9), these changes being different for each of these components. The most striking contrast between the fluorescence of the neurosecretory substance and the rest of the structures of the cell was observed in the pH 4.0–4.9 region. Especially stable preparations can be obtained by using a stain diluted with a buffer with pH about 4.5. The proposed modification of the method makes it possible to obtain preparations with more striking electivity of the secondary fluorescence of the neurosecretory substance than when using original method of Sterba.     

Modifications to the photosynthetic apparatus of higher plants in response to changes in the light environment

A brief review of the photosynthetic apparatus of higher plants is given, followed by a consideration of the modifications induced in this apparatus by changes in light intensity and light quality. Possible strategies by which plants may optimize photosynthetic activity by both long- and short-term modifications of their photosynthetic apparatus in response to changing light regimes are discussed.     

Experience overrides personality differences in the tendency to follow but not in the tendency to lead

In many animal groups, coordinated activity is facilitated by the emergence of leaders and followers. Although the identity of leaders is to some extent predictable, most groups experience frequent changes of leadership. How do group members cope with such changes in their social role? Here, we compared the foraging behaviour of pairs of stickleback fish after a period of either (i) role reinforcement, which involved rewarding the shyer follower for following, and the bolder leader for leading, or (ii) role reversal, which involved rewarding the shyer follower for leading, and the bolder leader for following. We found that, irrespective of an individual''s temperament, its tendency to follow is malleable, whereas the tendency to initiate collective movement is much more resistant to change. As a consequence of this lack of flexibility in initiative, greater temperamental differences within a pair led to improved performance when typical roles were reinforced, but to impaired performance when typical roles were reversed.     

Challenges to therapy in the future

Quadruple therapy (with a proton pump inhibitor (PPI), metronidazole, tetracycline and bismuth) is generally reserved for second-line treatment; however, studies using this regimen for 7 days have found it to be effective even in metronidazole-resistant strains. Resistance is an ongoing problem with antimicrobial therapy but considerable progress has now been made into understanding the underlying genetic mechanisms of this process. Metronidazole resistance in Europe is usually in the range of 20-30% of strains but may be as high as 70% in some countries. One genetic mechanism involved is thought to be a mutation of the rdxA gene. Macrolide resistance appears to be on the increase in Europe, varying from 1% in some countries to 13% in others. The genetic mechanism involved has been shown to be a point mutation of a ribosomal RNA. Amoxicillin resistance is an emerging problem that has an adverse effect on eradication rates in clinical practice. Resistance has been shown to be caused by the absence of one of the four binding proteins in the cell wall. Few novel antibiotics have been developed for use in eradication therapy, although rifabutin, secnidazole and furazolidone have shown some success as part of combination therapy. Alternative therapies that have been tested include mucosal protective agents which have been used in place of a PPI in some eradication regimens with some success, and the somatostatin analog, octreotide, that has been used as part of quadruple therapy in place of a PPI and produced eradication rates of approximately 88%. The ultimate challenge is still to develop a safe and effective vaccine against Helicobacter pylori. Current and future research will also focus on identifying genetic targets for therapy, adhesion molecule analogs to prevent binding of the bacterium, and urease inhibitors. The current triple therapy treatment options available for the eradication of Helicobacter pylori infection are over 90% effective in susceptible organisms and there are very few medical conditions to which we can offer such efficacious treatment. Unfortunately, the recommendations made at consensus conferences are not always put into practice and physicians in primary care may be unaware of the true efficacy of eradication therapy. Treatment is very simple: three drugs, twice a day for 1 week. The main focus for both primary care physicians and gastroenterologists should be to reinforce the need for patient compliance, otherwise we will see an increase in antibiotic resistance. Patients should be prewarned that they may experience some mild side effects and should be encouraged to complete the course of treatment. The real challenge for the future will be the management of patients who do not respond to first-line treatment. This paper will focus on potential problems with therapy, such as antibiotic resistance, and possible future solutions, such as novel antibiotics and vaccines.     

Predisposition to aneuploidy in the oocyte

While the incidence of predisposition to aneuploidy in the oocyte increases with age, there is also evidence of increased incidence in young women with recurrent miscarriage, recurrent aneuploidy, or recurrent implantation failure after in vitro fertilization. There is evidence from mouse models and from observations in humans that follicle-stimulating hormone (FSH) probably has a direct or indirect effect on the occurrence of oocyte aneuploidy. It seems that increased endogenous or exogenous FSH could induce meiotic disruption. Although the effect of FSH may explain the age-related increase in aneuploidy rate, many questions remain regarding young women, even if their FSH level is sometimes increased. Disruption of meiotic gene expression caused by exposure to environmental contaminants or by gene defects could also predispose to oocyte aneuploidy. Such abnormalities could impact on the oocyte pool, recombination and synapsis during fetal life, or oocyte growth.     

中国豆科植物新资料

报道了中国豆科5种及1变种的省级分布新记录,即肉色土圆儿在陕西、刺桐在海南、劲直刺桐在贵州、云南刺桐在西藏、渐尖叶鹿藿在贵州、黧豆在云南省的分布新记录;根据国际植物命名法规订正了锈毛两型豆和球穗千斤拔两个种的作者引证。