The Development of the Sulci and Gyri of the Bovine Cerebral Hemispheres     

Graham J.  Louw 《Anatomia, histologia, embryologia》1989,18(3):246-264

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Ertragsreaktionen von Zuckerrüben in den internationalen organischen Stickstoffdauerdün‐Gungsversuchen (IOSDV) Rauischholzhausen und Wrocław‐Swojec     

Bernd Honermeier  Lothar Behle‐Schalk  Leslaw Zimny  Roman Sniady  Dariusz Malak 《Archives of Agronomy and Soil Science》2013,59(5-6):459-471

Gegenstand der Untersuchungen sind zwei Dauerfeldversuche, die im Jahr 1984 in Rauischholzhausen (Deutschland) und im Jahr 1996 in Wroc?aw‐Swqjec (Polen) mit vergleichbarer Methode und Zielstellung angelegt wurden. Ausgewertet wurden hier die Zuckerrübenerträge im Mittel der dreijährigen Rotation der Jahre 1997–1999 in Abhängigkeit von organischen und mineralischen Düngungsmaßnahmen. Die erzielten Ergebnisse unterstreichen die Bedeutung der organischen Düngung für die Ertragssicherung im Zuckerrübenanbau. Die untersuchten organischen Dünger Stalldung, Stroh und Biokompost verbesserten die Ertragswirksamkeit mineralischer N‐Gaben.

Die ertragssteigernde Wirkung organischer Dünger war bei fehlender oder niedriger mineralischer N‐Düngung größer als bei hohen N‐Gaben. Auf stark lehmigem Sandboden (Wrozlaw) wurden höhere Ertragseffekte erzielt als auf schwerem Lehmboden (Rauischholzhausen). Die Blatterträge wurden durch die angewendeten Düngungsmaßnahmen stärker beeinflußt als die Rübenerträge. Stroh und Biokompost zeigten die gleichen Ertragseffekte wie Stalldung.  相似文献   

Trials with rafoxanide. 3. Efficacy of rafoxanide against the larvae of the sheep nasal bot fly Oestrus ovis, Linné, 1761     

I G Horak  J P Louw  S M Raymond 《Journal of the South African Veterinary Medical Association》1971,42(4):337-339

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Schalk 《Forstwissenschaftliches Centralblatt》1906,28(11):569-579

Ohne Zusammenfassung  相似文献   

Evaluation of the phytoestrogenic activity of Cyclopia genistoides (honeybush) methanol extracts and relevant polyphenols     

Verhoog NJ  Joubert E  Louw A 《Journal of agricultural and food chemistry》2007,55(11):4371-4381

Unfermented C. genistoides methanol extracts of different harvestings and selected polyphenols were evaluated for phytoestrogenic activity by comparing binding to both ER subtypes, transactivation of an ERE-containing promoter reporter, proliferation of MCF-7-BUS and MDA-MB-231 breast cancer cells, and binding to SHBG. The extracts from one harvesting of C. genistoides (P104) bound to both ER subtypes. All extracts transactivated ERE-containing promoter reporters via ERbeta but not via ERalpha. All extracts, except P122, caused proliferation of the estrogen-sensitive MCF-7-BUS cells. Proliferation of MCF-7-BUS cells was ER-dependent as ICI 182,780 reversed proliferation. Physiologically more relevant, extracts antagonized E2-induced MCF-7-BUS cell proliferation. Furthermore, all extracts, except P122, induced proliferation of the estrogen-insensitive MDA-MB-231 cells, suggesting that the extracts are able to induce ER-dependent and ER-independent cell proliferation. Binding to SHBG by extracts was also demonstrated. These results clearly show that C. genistoides methanol extracts display phytoestrogenic activity and act predominantly via ERbeta. HPLC and LC-MS analysis, however, suggests that the observed phytoestrogenic activity cannot be ascribed to polyphenols known to be present in other Cyclopia species.  相似文献   

Identification of tomato cultivars (Lycopersicon esculentum) by polyacrylamide isoelectric focusing     

Gisela Henn  A. W. H. Neitz  A. I. Louw 《Euphytica》1992,62(2):77-82

Summary Isozyme analyses have been used for the definitive identification of many plant cultivars, but not for cultivated tomatoes. Six isozyme systems, namely alcohol dehydrogenase, acid phosphatase, phosphoglucomutase, esterase, phosphoglucoisomerase and 6-phosphogluconate dehydrogenase of tomato seed extracts were resolved by isoelectric focusing on polyacrylamide gels with a narrow pH gradient. Nine alcohol dehydrogenase phenotypes were distinguished which, with three acid phosphatase phenotypes, identified twelve of the seventeen cultivars. Fewer differences were found for the other isozymes. Since this method could differentiate between breeding parents and their progeny it is concluded that further investigations are warranted.Abbreviations APS acid phosphatase - ADH alcohol dehydrogenase - EST esterase - IEF isoelectric focusing - PGI phosphoglucoisomerase - PGM phosphoglucomutase - 6-PGDH 6-phosphogluconate dehydrogenase - RFLP restriction fragment length polymorphism - VOPRI Vegetable and Ornamental Plant Research Institute  相似文献   

Levels of host plant resistance to banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), in African Musa germplasm     

Andrew Kiggundu  Clifford S. Gold  Maryke T. Labuschagne  Dirk Vuylsteke  Schalk Louw 《Euphytica》2003,133(3):267-277

Forty-five Musa clones, including endemic and introduced cultivars plus hybrids, were evaluated for resistance against the banana weevil, Cosmopolites sordidus, in a field trial in Uganda. The predominant groups of staple crops, East African highland bananas (Musa spp. AAA) and plantains (Musaspp. AAB), as well as plantain-derived hybrids (AAB × AA), showed the highest levels of susceptibility to this pest. These were followed by dessert bananas (Musa spp. AAA), exotic bananas (Musa spp. ABB) and finally diploids of M. acuminata (AA). Hybrids of banana origin were highly resistant. Some East African highland cultivars, especially brewing types (e.g., Kabula, Bagandeseza, Ediirira), showed intermediate levels of resistance. Among the non-highland bananas, high levels of resistance were observed in Yangambi-Km5 (AAA), Cavendish (AAA), Gros Michel (AAA), Kayinja (ABB, Pisang Awak subgroup), Ndiizi (AB, Ney Poovan subgroup)and Kisubi (Ney Poovan subgroup). The highest resistance was observed in banana hybrids TMB2×7197-2, TMB2×8075-7 and the wild banana Calcutta-4 (AA). These were considered the best sources of resistance for a weevil resistance-breeding programme with the two hybrids commonly used as improved male parents. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Spatiotemporally interactive growth dynamics in selected South African forests: Edaphoclimatic environment, crowding and climate effects     

Armin H.W. Seydack  Graham DurrheimJosua H. Louw 《Forest Ecology and Management》2011,261(7):1152-1169

Stand-level tree diameter growth patterns were explored for evergreen moist forests in the southern Cape, South Africa. Results of standard multiple regression analyses, involving 934 permanent sample plots with data spanning a 10-year interval, revealed that stand-level increment of canopy species in the canopy layer (>30 cm dbh) was significantly determined by inherent species-specific growth capacities (species composition of the stand), water availability, forest matrix crowding and tree condition impairment (age-related manifestations of reduced vitality indicated by signs of crown die-back, damage and stem rot). In contrast, stand-level increment of trees of canopy species in the subcanopy layer (10-20 cm dbh) was prominently shaped by light availability, as mainly determined by the degree of canopy-level disturbance (mortality rate of trees >30 cm dbh), crowding (canopy-level overhead and forest matrix crowding) and proximity to conspecific adults (within 6-8 m). In addition to species-inherent and resource factors, considerable variation in stand-level growth resulted from site-climate interactions. For 507 of the permanent sample plots, increment data was available for two consecutive 10-year intervals; permitting the analysis of spatiotemporal interactions of growth patterns (repeated measures ANOVA). In the Knysna forests higher canopy-level increment rates were associated with the moister southerly facing slope sites in comparison with the drier northerly facing and ridge sites during the first increment period. During the second increment period, increment rates on the drier, but better illuminated sites had increased disproportionately. In contrast, in the Tsitsikamma forests, higher increment rates during the second increment period were encountered on moister flat bottomland sites (with extended periods of subsoil wetness) than on the comparatively drier southerly facing slope sites (increment period × site-based water availability × forests interaction). In both forests relatively higher growth performance of subcanopy-level trees during the second increment period was associated with stands experiencing conditions of enhanced light availability. Atmospheric temperatures were higher during the second increment period (mean periodic T_max: + 0.64 °C). The detected spatiotemporal interactions were interpreted as site × climate interactions where site-related conditions of favourable light or water availability resulted in enhanced temperature-linked growth responses during the second increment period. A metabolic performance trade-off model provided a framework for the interpretation of these complex site-climate interactions by placing the patterns of forest growth into an ecophysiological explanatory context.  相似文献   

Genetic trends for objectively measured and subjectively assessed traits in a Dorper sheep flock     

Oliver Tendayi Zishiri  Schalk Willem Cloete  Johannes Jacobus Olivier  Kennedy Dzama 《Tropical animal health and production》2013,45(2):517-524

Genetic trends were constructed to monitor the genetic change for subjectively assessed and objectively measured traits using data emanating from complete records from the National Small Stock Improvement Scheme database and performance records accumulated by a single breeder over a period of 24 years. The objectively measured production traits considered were weaning weight, post-weaning weight (PWW), yearling weight, average daily weight gain to weaning (ADGW), average daily weight gain during post-weaning phase (ADGPW) and average daily weight gain up to yearling age. The subjectively assessed traits (scored on a five-point scale) were conformation, fat distribution, size, type and colour. Direct genetic trends for live weight and growth traits (with the exception of ADGPW) were positive. All the objectively measured traits where maternal effects were significant, except PWW, registered small declines in maternal breeding values. The fastest genetic progress was attained by ADGW, which amounted to 0.29 % of the overall phenotypic mean per annum. Conformation and type exhibited positive but slow increments in direct breeding values at an equivalent annual rate amounting to 0.12 and 0.09 % of the overall phenotypic mean, respectively. Size demonstrated a negative genetic trend of ?0.14 % of the overall phenotypic mean per annum. Genetic trends for fat distribution and colour were negligible. It was concluded that breeders should focus more on the performance recording of objective traits as they are likely to respond favourably to selection pressure.  相似文献   

Postharvest decay of nectarine and plum caused by Penicillium spp.     

J. P. Louw  L. Korsten 《European journal of plant pathology / European Foundation for Plant Pathology》2016,146(4):779-791

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