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1.
Sun M 《Science (New York, N.Y.)》1986,232(4748):316
2.
Sun M 《Science (New York, N.Y.)》1986,231(4739):667-668
3.
Sun M 《Science (New York, N.Y.)》1983,220(4600):935
Briefly noted is Rep. Albert Gore's introduction of legislation to create a commission to review developments in genetic engineering with potential human application. The proposed commission would consider medical, legal, ethical, and social implications of this research. It would be a purely advisory commission composed of six scientists; six experts in law, theology, ethics, or the social sciences; and three laymen. 相似文献
4.
Comparing mating designs to restore seed production of interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum 下载免费PDF全文
Muhammad Naeem Isabelle Marjorie Verry Peter D. Kemp James P. Millner Warren Mervyn Williams 《Plant Breeding》2017,136(3):420-426
Interspecific hybrids between Trifolium uniflorum and cultivated white clover (Trifolium repens) have highly useful characteristics for temperate pastoral systems derived from both parent species. However, the early hybrids (F1 and BC1) also have unacceptably poor seed production for commerce. This study analysed the basis for the poor seed production and investigated breeding strategies for overcoming the problem. The BC1F1 generation produced lower‐than‐expected numbers of heads per plant and seeds per floret. Backcrossing of selected hybrids to white clover corrected these deficiencies and created new variation. Seed numbers were also returned to near target levels by recurrent selection within the BC1 generation. Thus, it was possible to retain a theoretical average of 25% of T. uniflorum genome and still achieve high seed production per plant. The BC1F2 and BC2F1 generations produced high seed numbers per plant, along with reasonable variation. Both of these second‐generation hybrid forms have high reproductive potential and should be the focus for the selection of the desired combinations of agronomic and seed production traits. 相似文献
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6.
Kathleen Ella Chow Andrew William Stent Marjorie Milne 《Veterinary radiology & ultrasound》2014,55(1):74-78
A 4‐year‐old German shorthaired pointer presented with collapse and hematochezia. Radiographs showed gas and fluid‐distended small intestines and loss of serosal detail. Ultrasound examination showed hypomotile, fluid‐distended small intestines, and thrombosed jejunal veins. Multiphasic contrast‐enhanced computed tomography was performed and showed a CT “whirl sign,” an important but nonspecific sign of intestinal volvulus in human patients. At surgery, the majority of the small intestine was entangled in the volvulus and showed black discoloration. The patient was euthanized. Postmortem evaluation yielded a diagnosis of jejunoileal mesenteric volvulus secondary to a congenital omphalomesenteric duct remnant. 相似文献
7.
Singapore Island suffered one of the highest known deforestation rates in the tropics from the mid-to-late 19th century when over 95% of its native lowland forest was cleared. We compared the current bird community structure and composition among three habitat types, i.e., old (>50 years, 7-935 ha) and young (?50 years, 29-49 ha) naturally regenerating secondary forests and abandoned wooded plantations (27-102 ha) dominated by exotic species. Forest patch area had the strongest influence on the current species richness. The overall bird richness was not greater in most mature forest patches, but 20 species were only found in the old secondary forests and five of these were found in <50% of these patches. The rapid decrease in the number of forest species in plantations was offset by an increase in the number of open habitat species. Comparisons with current bird communities in nearby mainland forest sites (Peninsular Malaysia) suggest that the forest avifauna of Singapore is depauperate. The preservation of larger mature and maturing forests is therefore required for conserving the extant forest avifauna in Singapore. Connecting isolated patches can also be envisioned to facilitate movements of forest birds that have low densities and restricted distribution. 相似文献
8.
Seshadri R Adrian L Fouts DE Eisen JA Phillippy AM Methe BA Ward NL Nelson WC Deboy RT Khouri HM Kolonay JF Dodson RJ Daugherty SC Brinkac LM Sullivan SA Madupu R Nelson KE Kang KH Impraim M Tran K Robinson JM Forberger HA Fraser CM Zinder SH Heidelberg JF 《Science (New York, N.Y.)》2005,307(5706):105-108
9.
The appearance and development of buds on leaf cuttings of Begonia × hiemalis in long and short days
Bud initiation in leaf cuttings of Rieger begonia ‘Schwabenland Red’ was not affected by daylength. Approximately 30 buds per cutting were observed 13 weeks after insertion. Of these, an average of 8.2 developed into fully grown shoots in long days as opposed to 1.9 in short days. Competition between buds was apparent in both treatments, its effect being greatest on buds with fewer than 4 leaf primordia. 相似文献
10.
de Vasconcellos Abdon AP Coelho de Souza G Noronha Coelho de Souza L Prado Vasconcelos R Araújo Castro C Moreira Guedes M Pereira Lima RC de Azevedo Moreira R de Oliveira Monteiro-Moreira AC Rolim Campos A 《Fitoterapia》2012,83(3):604-608
The present study was designed to verify whether frutalin (FTL) affords gastroprotection against the ethanol-induced gastric damage and to examine the underlying mechanism(s). Gastric damage was induced by intragastric administration of 0.2 ml of ethanol (96%). Mice in groups were pretreated with FTL (0.25, 0.5 and 1 mg/kg; i.p.), cimetidine (100 mg/kg; p.o.), or vehicle (0.9% of NaCl, 10 mL/kg; p.o.), 30 min before ethanol administration. They were sacrificed 30 min later, the stomachs excised, and the mucosal lesion area (mm2) measured by planimetry. Gastroprotection was assessed in relation to inhibition of gastric lesion area. To study the gastroprotective mechanism(s), its relations to capsaicin-sensitive fibers, endogenous prostaglandins, nitric oxide, sulphydryls, ATP-sensitive potassium channels, adrenoceptors, opioid receptors and calcium channels were analyzed. Treatments effects on ethanol-associated oxidative stress markers GSH and MDA were measured in gastric tissue. FTL afforded a dose-unrelated gastroprotection against the ethanol damage. However, it failed to prevent the ethanol-induced changes in the levels of GSH and MDA. It was observed that the gastroprotection by FTL was greatly reduced in animals pretreated with capsazepine, indomethacin, L-NAME or glibenclamide. Considering the results, it is suggested that the FTL could probably be a good therapeutic agent for the development of new medicine for the treatment of gastric ulcer. 相似文献