Sorghum Insect Problems and Management

Sorghum (Sorghum bicolor) has high levels of starch,sugar,and fiber and is one of the most important energy crops in the world.Insect damage is one of the challenges that impacts sorghum biomass production.There are at least 150 insect species that can infest sorghum varieties worldwide.These insects can complete several generations within a growing season,they target various parts of sorghum plants at developmental stages,and they cause significant biomass losses.Genetic research has revealed the existence...     

The Organization of mitochondria in growing hyphae of Neurospora crassa

Details of mitochondrial system organization and behavior in the tip of growing N. crassa hyphae and hyphal fragments were studied by means of cell-permeable mitochondria-selective probes in glucose- and sorbitol-containing media. It was shown that filamentous mitochondria concentrate in the 30-μm apical zone of growing hyphae and hyphal fragments independently of the carbon source. The mitochondrial assemblies propagate forward with elongation of hypha, split upon apical branching, and are formed de novo when branches are formed away from the growing tip. These activities resemble microtubule behavior. Co-staining with Mitotracker Red and Mitotracker Green revealed possible functional heterogeneity in subpopulations of mitochondria. It was proposed that the observed features are governed by the microtubular network, while the primary function of mitochondria was to sustain the growth rate. The organizing role of electrical gradients on the growing tip and their influence on mitochondrial and microtubular networks are discussed.     

桃儿七光合生理特性的地理差异研究

对中国由南向北5个种源地桃儿七(Sinopodophyllum hexandrum)的光合生理生态特性进行了研究.结果表明:(1)北部宁夏六盘山地区植株的光饱和点(LSP)和光补偿点(LCP)最高,表观光量子效率(AQY)、瞬时光能利用效率(ILUE)和最大光合速率(Pmax)最低,光合能力最差;最南部云南纳帕海植株的LSP和LCP很低,但因其AQY和ILUE最高,故其Pmax最大,强光下的光合能力最高.(2)最南部云南纳帕海和最北部甘肃兴隆山个体的羧化效率(CE)最高,且CO2补偿点(CCP)较低,因此CO2利用率较高;而较南部四川刷经寺个体的CE最低,且CCP最高,故CO2利用效率最低.(3)各种源植株叶片的叶绿素总量及叶绿素a含量无显著差异,而不同地区个体的Chla/Chlb值差异显著,最北部甘肃兴隆山植株的Chla/Chlb值最大,而南部四川刷经寺的Chla/Chlb值最小.(4)各种源地植株的水分利用效率(WUE)和蒸腾速率(Tr)对光量子通量密度(PFD)与CO2浓度的响应过程也表现出显著的地理分异.总的来看,桃儿七是一种喜光但又较耐阴植物,但不同分布区桃儿七的光合生理生态特征已经出现了较显著的地理分化.     

Acid-base and gas-transfer properties of the blood of newborn infants

The concentration of HCO ₃ ^? , pH, pO₂, sO₂, and pCO₂ were measured in the total umbilical blood of neonates born in January–February (n = 169) and June–July (n = 172). The former group displayed higher values of pH, pO₂, and sO₂, whereas pCO₂ and the concentration of HCO ₃ ^? were higher in the latter group. There was a 70–80% coincidence of the variants in both groups (the regions of statistical transgressions); seasonal factors were responsible for 20–30% of the differences.     

Enhanced recovery of mechanical function in the canine heart by seeding an extracellular matrix patch with mesenchymal stem cells committed to a cardiac lineage

The need to regenerate tissue is paramount, especially for the heart that lacks the ability to regenerate after injury. The urinary bladder extracellular matrix (ECM), when used to repair a right ventricular defect, successfully regenerated some mechanical function. The objective of the current study was to determine whether the regenerative effect of ECM could be improved by seeding the patch with human mesenchymal stem cells (hMSCs) enhanced to differentiate down a cardiac linage. hMSCs were used to form three-dimensional spheroids. The expression of cardiac proteins was determined in cells exposed to the spheroid formation and compared with nonmanipulated hMSCs. To determine whether functional calcium channels were present, the cells were patch clamped. To evaluate the ability of these cells to regenerate mechanical function, the spheroids were seeded on ECM and then implanted into the canine heart to repair a full-thickness right ventricular defect. As a result, many of the cells spreading from the spheroids expressed cardiac-specific proteins, including sarcomeric alpha-actinin, cardiotin, and atrial natriuretic peptide, as well as the cell cycle markers cyclin D1 and proliferating cell nuclear antigen. A calcium current similar in amplitude to that of ventricular myocytes was present in 16% of the cells. The cardiogenic cell-seeded scaffolds increased the regional mechanical function in the canine heart compared with the unmanipulated hMSC-seeded scaffolds. In addition, the cells prelabeled with fluorescent markers demonstrated myocyte-specific actinin staining with sarcomere spacing similar to that of normal myocytes. In conclusion, the spheroid-derived cells express cardiac-specific proteins and demonstrate a calcium current similar to adult ventricular myocytes. When these cells are implanted into the canine heart, some of these cells appear striated and mechanical function is improved compared with the unmanipulated hMSCs. Further investigation will be required to determine whether the increased mechanical function is due to a differentiation of the cardiogenic cells to myocytes or to other effects.     

Functional Changes in Blood Microcirculation in the Skin of the Foot during Heating Tests in Patients with Diabetes Mellitus

The paper shows the possibility of using the laser Doppler flowmetry method for the assessment of system of blood microcirculation in the lower limbs of patients with diabetes mellitus. A series of experimental studies involving 76 patients with diabetes mellitus and 46 healthy volunteers was carried out. The state of peripheral blood flow was assessed during the local heating tests with different temperature regimes. The wavelet analysis of LDF-grams was used to evaluate the adaptive changes of microcirculation during the temperature tests. The data show that the proposed methodology in the form of heating tests and the use of the wavelet transform in the analysis of LDF-grams allows the evaluation of adaptation processes in the microcirculatory bed during thermal tests and the detection of the preclinical stage of trophic disorders.     

A型肉毒毒素轻链基因的克隆及其结构分析

以献报道的A型肉毒毒素基因全序列为标准,设计并合成一对引物,自肉毒梭菌基因组中扩增出肉毒毒素轻链基因片段,并将扩增产物与pGEM—T载体在体外连接,构建测序重组质粒,进行测序和基因结构分析。PCR扩增获得了产物为1 364bp的DNA片段,测序结果与DNA数据库对照检索分析证明,此基因片段与GenBank中的A型肉毒毒素LC基因的一致性达99．9％以上,可以认为克隆的基因为A型肉毒毒素LC基因。     

THE NATURAL LIFE CYCLE IN WILD POPULATIONS OF DIATOMA MONILIFORMIS (BACILLARIOPHYCEAE) AND ITS DISRUPTION IN AN ABERRANT ENVIRONMENT1

We studied how size variation in populations of Diatoma moniliformis Kütz. was influenced by environmental effects on the diatom life cycle. One of the two populations sampled monthly in the northern Baltic Sea grew under natural conditions; the other population was in a cooling water discharge channel of a nuclear power plant, where the temperature and flow rate of the water were artificially higher. The life cycle was synchronous at the natural site, with sexual reproduction occurring in the winter; most of the initial cells were found in March-April. After this, a reduction in cell size occurred, and the vegetative life cycle consisted of two parts. During the first part, cell volume decreased, whereas the surface area to volume ratio increased, and during the second part of the cycle, both of these parameters decreased. No direct evidence was found for the existence of a supra-annual life cycle in D. moniliformis, as convincing modes fm large cells were lacking in the size-frequency distributions. It was concluded from extrapolations of the data that the natural life cycle of D. moniliformis probably lasts 2 or 3 years. The changes in cell proportions during the life cycle fit well with annual growth cycles of D. moniliformis at the natural site (i.e. the cells had high surface area to volume ratios during the period of optimal growth in late spring [May-June]). At the site affected by cooling water discharge, the synchronization of the natural life cycle was disrupted, but some seasonal size variation did occur. Under natural conditions, auxosporulation is probably triggered by a combination of small cell size, low water temperature (0–3° C), and rapidly increasing light intensity or daylength in late winter to early spring. When these conditions were not met (e.g. at the heated site, the required low temperature was absent), auxosporulation did not occur simultaneously. This paper also presents scanning electron photomicrographs showing the typical shape and fine structure of the initial cell of D. moniliformis. These cells are semispherical in cross section, possess a pronounced curvature along the longitudinal axis, and are bent in the perualvar plane.     

Analysis of the cable structure of blue-green algae

Peculiarities of electrical responses under local illumination of filamentous cyanobacteria (blue-green algae). Phormidium uncinatum were studied by means of extracellular electrodes. Recording of electrical responses at different distances from the exposure place and comparison of these data with the results obtained on physical model of Ph. uncinatum end expected response parameters computed made it possible to estimate the parameters of the cable which can serve as the object model: RC=440 c/cm2 and lambda min greater than or equal to 0.07 cm. According to these values and taking membrane capacity as C=10(-6) phi/cm2, intracellular resistance Rm=10(7) Ohm and conductivity of the surface membrane G less than or equal to 10(-6) I/Ohm cm2 were estimated.