排序方式: 共有54条查询结果,搜索用时 15 毫秒
11.
Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), an invasive scale insect, attacks different species of Cycas (Cycadales: Cycadaceae) in Taiwan. Development, survival and fecundity of A. yasumatsui were studied on Cycas taitungensis at 24 °C, 70 ± 10% RH, and a photoperiod of 12:12 (L:D) h under laboratory conditions. Data on the life history of A. yasumatsui were analyzed using the age-stage, two-sex life table, to address variable development rates among individuals and between sexes. The egg incubation time was 7.26 days for both females and males and female nymphal development duration was 28.65 days. The development duration of male nymphal stages + pupal stage was 19 days. The total pre-oviposition period (TPOP) was 35.92 days. The maximum longevity of female adults was 67 days and 1 day for males. The intrinsic rate of increase (r) was 0.100 day-1, the finite rate of increase (λ) was 1.11 day-1, the net reproduction rate (Ro) was 111.51 offspring /individual, and the mean generation time (T) was 47.24 day. Life table data can be used to project population growth, to design mass rearing programs and to establish management tactics to control insect pests. 相似文献
12.
Background
Echocardiography plays an integral role in the diagnosis of congestive heart failure including measurement of left heart pressure as well as mechanical dyssynchrony.Methods
In this report we describe novel therapeutic uses of echo pulsed wave Doppler in atrioventricular pacemaker optimization in patients who had either not derived significant symptomatic benefit post biventricular pacemaker implantation or deteriorated after deriving initial benefit. In these patients atrioventricular optimization showed novel findings and improved cardiac output and symptoms.Results
In 3 patients with Cheyne Stokes pattern of respiration echo Doppler showed worsening of mitral regurgitation during hyperpneac phase in one patient, marked E and A fusion in another patient and exaggerated ventricular interdependence in a third patient thus highlighting mechanisms of adverse effects of Cheyne Stokes respiration in patients with heart failure. All 3 patients required a very short atrioventricular delay programming for best cardiac output. In one patient with recurrent congestive heart failure post cardiac resynchronization, mitral inflow pulse wave Doppler showed no A wave until a sensed atrioventricular delay of 190 ms was reached and showed progressive improvement in mitral inflow pattern until an atrioventricular delay of 290 ms. In 2 patients atrioventricular delay as short as 50 ms was required to allow E and A separation and prevent diastolic mitral regurgitation. All patients developed marked improvement in congestive heart failure symptoms post echo-guided biv pacemaker optimization.Conclusion
These findings highlight the value of echo-guided pacemaker optimization in symptomatic patients post cardiac resynchronization treatment. 相似文献13.
BackgroundEpigenetic changes are being increasingly recognized as a prominent feature of cancer. This occurs not only at individual genes, but also over larger chromosomal domains. To investigate this, we set out to identify large chromosomal domains of epigenetic dysregulation in breast cancers.ResultsWe identify large regions of coordinate down-regulation of gene expression, and other regions of coordinate activation, in breast cancers and show that these regions are linked to tumor subtype. In particular we show that a group of coordinately regulated regions are expressed in luminal, estrogen-receptor positive breast tumors and cell lines. For one of these regions of coordinate gene activation, we show that regional epigenetic regulation is accompanied by visible unfolding of large-scale chromatin structure and a repositioning of the region within the nucleus. In MCF7 cells, we show that this depends on the presence of estrogen.ConclusionsOur data suggest that the liganded estrogen receptor is linked to long-range changes in higher-order chromatin organization and epigenetic dysregulation in cancer. This may suggest that as well as drugs targeting histone modifications, it will be valuable to investigate the inhibition of protein complexes involved in chromatin folding in cancer cells.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-015-0719-9) contains supplementary material, which is available to authorized users. 相似文献14.
M.M. Shahzad S. Bashir S.M. Hussain A. Javid M. Hussain N. Ahmed M.K.A. Khan M. Furqan I. Liaqat T. Rafique F. Khalid 《Saudi Journal of Biological Sciences》2021,28(3):1944-1953
Several anti-nutritional substances are found in plant derivatives for example phytate, that make the nutrients and minerals unavailable to fish, hence leading to poor growth performance. Presence of the anti-nutrient factor such as phytate is a chelated compound and need enzyme for its breakdown and availability of nutrients to improve fish growth. This research work was performed to check the improvement of overall performance of Cyprinus carpio fingerlings by the help of phytase addition in Moringa oleifera by- products based diet. Combination of Moringa seed meal and Moringa leaf meal was utilized as test ingredient to formulate seven test feeds, containing graded levels of phytase (0, 500, 650, 800, 950, 1100 and 1250 FTU kg−1). In feeding trial of 70 days, fingerlings were given feed two times in a day at the rate of 4% of wet weight of their bodies and faeces were collected. According to current results, it was found that growth performance parameters i.e. weight gain; 25 g, specific growth rate; 1.67 and feed conversion ratio; 1.10 were improved to maximum at 950 FTU kg−1. Digestibility of nutrients (crude protein; 73%, crude fat; 71% and gross energy; 67%) and minerals absorption was also maximum (Ca; 70%, Zn; 66%, K; 74%, Mn; 66% and P; 71%) at 950 FTU kg−1. Lowest growth efficiency, nutrient digestibility and mineral absorption were observed in fingerlings fed at control diet (0 FTU kg−1). Results of the current study, proved that 950 FTU kg−1 is the most optimum level of phytase to formulate economical and ecofriendly feed for improved growth of C. carpio fingerlings as it decreases the discharge of minerals and nutrients in water bodies. 相似文献
15.
16.
17.
Lessman CA Nathani R Uddin R Walker J Liu J 《Molecular reproduction and development》2007,74(1):97-107
We have developed a new technique called Computer-Aided Meiotic Maturation Assay (CAMMA) for imaging large arrays of zebrafish oocytes and automatically collecting image files at regular intervals during meiotic maturation. This novel method uses a transparency scanner interfaced to a computer with macro programming that automatically scans and archives the image files. Images are stacked and analyzed with ImageJ to quantify changes in optical density characteristic of zebrafish oocyte maturation. Major advantages of CAMMA include (1) ability to image very large arrays of oocytes and follow individual cells over time, (2) simultaneously image many treatment groups, (3) digitized images may be stacked, animated, and analyzed in programs such as ImageJ, NIH-Image, or ScionImage, and (4) CAMMA system is inexpensive, costing less than most microscopes used in traditional assays. We have used CAMMA to determine the dose response and time course of oocyte maturation induced by 17alpha-hydroxyprogesterone (HP). Maximal decrease in optical density occurs around 5 hr after 0.1 micro g/ml HP (28.5 degrees C), approximately 3 hr after germinal vesicle migration (GVM) and dissolution (GVD). In addition to changes in optical density, GVD is accompanied by streaming of ooplasm to the animal pole to form a blastodisc. These dynamic changes are readily visualized by animating image stacks from CAMMA; thus, CAMMA provides a valuable source of time-lapse movies for those studying zebrafish oocyte maturation. The oocyte clearing documented by CAMMA is correlated to changes in size distribution of major yolk proteins upon SDS-PAGE, and, this in turn, is related to increased cyclin B(1) protein. 相似文献
18.
The stimulatory effect of thidiazuron (TDZ) has been investigated in shoot multiplication for a simple, efficient, rapid, and commercially applicable regeneration protocol of an important medicinal plant, Cassia alata. Furthermore, the effects of an increased photosynthetic photon flux density (PPFD) on photosynthesis, the functioning of the photosynthetic apparatus, and the response of the antioxidant enzymatic system were studied during the ex vitro establishment of micropropagated plantlets. Multiple shoots were induced by culturing nodal explants excised from an aseptic seedling on Murashige and Skoog (MS) medium supplemented with various concentrations (1.0, 2.5, 5.0, 7.5, or 10.0 μM) of TDZ for different treatment durations (2, 3, 4, or 6 wk). The highest number of shoots (17.9?±?0.3) and longest shoot length (4.6?±?0.1 cm) were achieved when explants were exposed to 5.0 μM TDZ for 4 wk and subsequently subcultured on growth regulator-free MS medium for 8 wk. In vitro rooting of isolated shoots was best achieved on full-strength MS medium containing 0.5 μM indole-3-butyric acid (IBA). The micropropagated shoots with well-developed roots were successfully established in pots containing Soilrite? followed by garden soil and grown in greenhouse with an 85% survival rate. During the acclimatization period, significant changes in the activity of the antioxidant enzymatic system were observed. An increase in superoxide dismutase (SOD) activity was measured throughout the acclimatization period. Likewise an upregulation of catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) enzyme activities were also observed. Pigment (chlorophyll a and b and carotenoids) content in ex vitro-formed leaves was significantly higher compared with those grown in vitro. These observed changes reflected the ability of plants to develop an antioxidant enzymatic defense system aiding in survival against oxidative stress and in reducing release of free radicals. 相似文献
19.
20.
Summary Cowpea rhizobia strains were examined with indigenous populations in nodulating cowpea (Vigna unguiculata (L) Walp) cv. Laura B. strain IRC256 formed dark nodules on cowpea, and were used as the standard against orthodox pink-nodule strains in evaluating nodulating competitiveness. The dark nodule phenotype and intrinsic antibiotic resistance pattern were used to identify the strains in the nodules. Our results showed the usefulness of the dark-nodule strain in evaluating nodulating competitiveness of cowpea rhizobia in soils where dark-nodule strains were not indigenous. 相似文献