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41.
Trends in, and potential causes of, insect pest problems of the Tasmanian blue gum, Eucalyptus globulus globulus, in south‐western Australia are reviewed. Historical evidence suggests that insect pest problems of E. g. globulus in south‐western Australia have greatly increased in the last 10 years, which corresponds to a time of rapid expansion of the blue gum industry in the region. Current major establishment pests include the African black beetle, Heteronychus arator, spring beetles, Liparetrus spp. and Heteronyx spp., and the wingless grasshopper, Phaulacridium vittatum. Current major pests of established trees are the Eucalyptus weevil, Gonipterus scutellatus, and chrysomelid beetles, Chrysophtharta spp. and Cadmus excrementarius. The occurrence of these insects on an introduced eucalypt is not unexpected because insect‐rich native eucalypt forests dominate the landscape where E. g. globulus plantations are grown. Insect damage may also be exacerbated because E. g. globulus is grown as a monoculture.  相似文献   
42.
SUMOylation is critical for numerous cellular signalling pathways, including the maintenance of genome integrity via the repair of DNA double-strand breaks (DSBs). If misrepaired, DSBs can lead to cancer, neurodegeneration, immunodeficiency and premature ageing. Using systematic human proteome microarray screening combined with widely applicable carbene footprinting, genetic code expansion and high-resolution structural profiling, we define two non-conventional and topology-selective SUMO2-binding regions on XRCC4, a DNA repair protein important for DSB repair by non-homologous end-joining (NHEJ). Mechanistically, the interaction of SUMO2 and XRCC4 is incompatible with XRCC4 binding to three other proteins important for NHEJ-mediated DSB repair. These findings are consistent with SUMO2 forming a redundant NHEJ layer with the potential to regulate different NHEJ complexes at distinct levels including, but not limited to, XRCC4 interactions with XLF, LIG4 and IFFO1. Regulation of NHEJ is not only relevant for carcinogenesis, but also for the design of precision anti-cancer medicines and the optimisation of CRISPR/Cas9-based gene editing. In addition to providing molecular insights into NHEJ, this work uncovers a conserved SUMO-binding module and provides a rich resource on direct SUMO binders exploitable towards uncovering SUMOylation pathways in a wide array of cellular processes.  相似文献   
43.
Systematic Parasitology - Henneguya Thélohan, 1892 is the second most species rich genus of myxozoans, with reports from freshwater and marine fish worldwide. In the Great Lakes...  相似文献   
44.
A two-month treatment of the chronic active hepatitis (HBsAg+) with isoprinosine produced quantitative and functional T-cells populations in patients with cellular response disorders. Immunological studies have shown that such an effect of isoprinosine lasted for about 4-5 months. Repeated administration of isoprinosine for one month normalized recurrent abnormalities in the monitored immunological parameters.  相似文献   
45.
A three-dimensional mathematical model of the human knee joint was developed to examine the role of single ligaments, such as an anterior cruciate ligament (ACL) graft in ACL reconstruction, on joint motion and tissue forces. The model is linear and valid for small motions about an equilibrium position. The knee joint is modeled as two rigid bodies (the femur and the tibia) interconnected by deformable structures, including the ACL or ACL graft, the cartilage layer, and the remainder of the knee tissues (modeled as a single element). The model was demonstrated for the equilibrium condition of the knee in extension with an anterior tibial force, causing anterior drawer and hyperextension. The knee stiffness matrix for this condition was measured for a human right knee in vitro. Predicted model response was compared with experimental observations. Qualitative agreement was found between model and experiment, validating the model and its assumptions. The model was then used to predict the change in graft and cartilage forces and joint motion of the knee due to an increment of load in the normal joint both after ACL removal and with various altered states simulating ACL reconstructions. Results illustrate the interdependence between loads in the ACL graft, other knee structures, and contact force. Stiffer grafts and smaller maximum unloaded length of the ligament lead to higher graft and contact forces. Changes in cartilage stiffness alter load sharing between ACL graft and other joint tissues.  相似文献   
46.
The pregnancy rate achieved with frozen semen using two packaging methods was compared in two separate experiments. The sperm-rich fraction of the semen was collected and immediately extended in an egg-yolk based extender to a final concentration of 100 x 10(6) sperm/ml. Half of each ejaculate was packaged in 4.0-ml plastic straws and the other half in 10-to 12-ml flattened aluminum tubes. After detection of a 35-mm follicle, mares were inseminated daily until ovulation. Pregnancy was detected, and embryonic vesicle size was measured by ultrasonic echography Days 14 to 26 after ovulation. The one-cycle pregnancy rate achieved using both packaging methods was 50% overall (23 46 ), with 46% (12 26 ) and 55% (11 20 ) rates achieved, respectively, using straws and aluminum tubes. These rates were not significantly different.  相似文献   
47.
Beaked whales are poorly known cetaceans with a peculiar dentition consisting of one or two pairs of mandibular tusks, sometimes accompanied by dozens of peg-like rudimentary teeth normally concealed in the gum tissue. This study investigated the ultrastructure, chemical and biomechanical properties of vestigial teeth in a specimen of Cuvier's beaked whale deposited in the Otago Museum collections. The juvenile individual had 49 needle-like vestigial teeth in situ on the lower jaws. Scanning electron microscopy images revealed a thin layer of semi-structured prismless enamel covering the teeth. Mechanical properties values were within the range of values reported for other cetaceans, suggesting relaxed biomechanical functional demands. Chemical analyses revealed preservation of the hydroxyapatite composition despite morphological simplification and vestigial nature. The presumed high incidence of vestigial teeth in Ziphius cavirostris, the small size and the degenerate nature of these structures are consistent with their interpretation as vestiges rather than atavisms.  相似文献   
48.
The development of fibrosis in the chronically hypertensive heart is associated with infiltration of inflammatory cells and cardiac hypertrophy. In this study, an inhibitor of the proinflammatory enzyme, group IIA human secretory phospholipase A2 (sPLA2-IIA), has been found to prevent collagen deposition as an important component of cardiovascular remodeling in a rat model of developing chronic hypertension. Daily treatment of young male spontaneously hypertensive rats (SHR) with an sPLA2-IIA inhibitor (KH064, 5-(4-benzyloxyphenyl)-4S-(phenyl-heptanoylamino)-pentanoic acid, 5 mg/kg/day p.o.) prevented increases in the content of perivascular (SHR 20.6 +/- 0.9%, n = 5; SHR+KH064 14.0 +/- 1.2%, n = 5) and interstitial (SHR 7.9 +/- 0.3%, n = 6; SHR+KH064 5.4 +/- 0.7%, n = 6) collagen in the left ventricle of rat hearts, but did not affect numbers of infiltrating monocytes/macrophages, left ventricular hypertrophy (SHR 2.88 +/- 0.08, n = 12; SHR+KH064 3.09 +/- 0.08 mg/g body weight, n = 9), increased systolic blood pressure, or thoracic aortic responses. This selective antifibrotic activity suggests that sPLA2-IIA may have an important but specific role in cardiac fibrosis, and that its inhibitors could be useful in dissecting molecular pathways leading to fibrotic conditions.  相似文献   
49.
50.
Optimization of adenosine analog inhibitors of bacterial NAD+-dependent DNA ligase is discussed. Antibacterial activity against Streptococcus pneumoniae and Staphylococcus aureus was improved by modification of the 2-position substituent on the adenine ring and 3′- and 5′-substituents on the ribose. Compounds with log D values 1.5-2.5 maximized potency and maintained drug-like physical properties.  相似文献   
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