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Consecutive Seasons (consecutive + season)
Selected AbstractsPair bond and breeding success in Blue Tits Parus caeruleus and Great Tits Parus majorIBIS, Issue 1 2005MIRIAM PAMPUS Data from 939 nests of the Blue Tit Parus caeruleus and 1008 nests of the Great Tit P. major from nestboxes provided in superabundance in mixed forest study sites between 1976 and 2001 were analysed to examine the effects of mate retention on breeding success and the relationship between mate fidelity and site fidelity. Most birds retained their former partner (76% in Great Tits and 65% in Blue Tits). The probability of a pair divorcing was affected by male age in Great Tits, divorce being more likely in pairs with first-year males. Great Tit pairs breeding together for a second season bred earlier, but had no higher breeding success than pairs breeding together for the first time. In Blue Tits laying date and start of incubation tended to be earlier in pairs breeding together for a second season, but hatching and fledging dates were not earlier than in other pairs. Great Tit pairs breeding together for two consecutive seasons bred earlier in the second season than in the first, but breeding success did not differ significantly between years. In both species, breeding performance did not differ between pairs that divorced after a season and pairs that stayed together. Thus breeding success did not determine whether a pair divorced or bred together again. Neither Blue Tits nor Great Tits improved their breeding performance through divorce. Blue Tit females even had fewer fledglings in the year after divorce than in the year before. Mate retention affected breeding site fidelity. Blue Tit females had greater breeding dispersal distances between consecutive years when re-mating than when breeding again with the same mate. In Great Tits both males and females dispersed more when re-mating than when retaining the former partner, suggesting that mate retention increased the chance of retaining the breeding site. In both species, breeding dispersal distances did not differ between pairs that divorced and pairs in which one mate disappeared. Because no major advantage of mate retention was evident, we suggest that mate retention evolved under different conditions than those found in study sites with high breeding densities and a superabundance of artificial nesting sites. [source] Effect of Straw on Yield Components of Rice (Oryza sativa L.) Under Rice-Rice Cropping SystemJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2006K. Surekha Abstract Field experiments were conducted at the Directorate of Rice Research experimental farm, ICRISAT campus, Patancheru, Hyderabad, during 1998,2000 for five consecutive seasons (three wet and two dry seasons) with five treatments [T1 , 100 % straw incorporation; T2 , 50 % straw incorporation; T3 , 100 % straw + green manure (GM) incorporation; T4 , 100 % straw burning and T5 , 100 % straw removal (control)] along with the recommended dose of fertilizers to evaluate the effect of different crop residue management (CRM) practices on yield components and yield of rice in rice,rice cropping sequence. The ammonium N measured at active tillering was higher in 100 % straw-added plots over 50 % straw addition and straw removal with maximum values in the straw + GM-incorporated plots. Among the yield components, tillers, panicles and spikelets were influenced from the second season of residue incorporation with significant increase in 100 % straw-added treatments. The increase in tiller and panicle number could be attributed to the increased NH4 -N in these treatments, which is evident from the significant correlation between tiller number and NH4 -N (r = 0.82**) and panicle number and NH4 -N (r = 0.87**). The influence of residue treatments on rice grain yield was observed from the third season onwards where incorporation of straw alone or in combination with GM and burning of straw significantly increased grain and straw yields. Grain yield showed significant positive correlation with the number of tillers (r = 0.74*,0.81**) and panicles (r = 0.74*,0.84**) in three treatments (T1, T3 andT4) where grain yields were significantly higher. The regression analysis showed that 57,66 % and 64,75 % of the variation in yield could be explained by tillers and panicles together in these three treatments during wet and dry seasons respectively. Thus, CRM practices such as addition of 100 % straw either alone or with GM and straw burning influenced the yield components (tillers, panicles and spikelets) positively and thereby increased rice grain yields. [source] Biodiversity and biogeography of the islands of the Kuril ArchipelagoJOURNAL OF BIOGEOGRAPHY, Issue 9 2003Theodore W. Pietsch Abstract Aim Based on seven consecutive seasons of biotic survey and inventory of the terrestrial and freshwater plants and animals of the 30 major islands of the Kuril Archipelago, a description of the biodiversity and an analysis of the biogeography of this previously little known part of the world are provided. Location The Kuril Archipelago, a natural laboratory for investigations into the origin, subsequent evolution, and long-term maintenance of insular populations, forms the eastern boundary of the Okhotsk Sea, extending 1200 km between Hokkaido, Japan, and the Kamchatka Peninsula of Russia. A chain of more than 56 islands, the system is only slightly smaller than the Hawaiian Islands, covering an area of 15,600 km2 and providing 2409 km of coastline. Methods Collections of whole specimens of plants and animals, as well as tissue samples for future molecular studies, were made by teams of scientists from Russia, Japan, and the USA, averaging 34 people for each of the seven annual summer expeditions (1994,2000). Floral and faunal similarities between islands were evaluated by using Sorensen's coefficient of similarity. The similarity matrix resulting from pair-wise calculations was then subjected to UPGMA cluster analysis. Results Despite the relatively small geographical area of all islands combined, the Kuril Island biota is characterized by unusually high taxonomic diversity, yet endemism is very low. An example of a non-relict biota, it originated from two primary sources: a southern source, the Asian mainland by way of Sakhalin and Hokkaido, and a northern source by way of Kamchatka. The contribution of the southern source biota to the species diversity of the Kurils was considerably greater than the northern one. Main conclusion The Bussol Strait, lying between Urup and Simushir in the central Kurils, is the most significant biogeographical boundary within the Archipelago. Of lesser importance are two transitional zones, the De Vries Strait or ,Miyabe Line', which passes between Iturup and Urup in the southern Kurils, and the fourth Kuril Strait, between Onekotan and Paramushir in the northern Kurils. [source] An experimental test for effects of the maternal environment on delayed germinationJOURNAL OF ECOLOGY, Issue 5 2010Katja Tielbörger Summary 1.,Recent models on bet-hedging germination in annual plants assume a negative relationship between the proportion of offspring that germinate and the quality of the maternal environment. An increase in the proportion of seeds remaining dormant in the next year, when produced in seasons with high reproduction may result from selection that avoids overcrowding in the following year. 2.,We present the first empirical test of this prediction by utilizing a field experiment in Israel which manipulated the entire maternal environment. We subjected semi-arid and Mediterranean annual plant communities to different rainfall treatments: control, reduced and increased rainfall. We then related maternal environment quality to offspring germination fractions for three focal species in two consecutive seasons. 3.,There was a negative relationship between the quality of the maternal environment and offspring germination fraction in four out of twelve cases. The negative relationship was stronger for the least competitive species and in the environment with high competition intensity, supporting the role of competition for the observed pattern. 4.,Our results suggest that competition with all neighbours is more likely to explain the pattern than sib competition. 5.,Synthesis. Our findings provide the first experimental evidence of a highly reliable cue (productivity of maternal environment) that allows for plants to respond to their future biotic environment. There is an urgent need for testing predictions of theoretical models in natural populations and for incorporating the role of density dependence in studies of bet-hedging germination. [source] Relationship between Carbon Isotope Discrimination and Grain Yield in Spring Wheat Cultivated under Different Water RegimesJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 10 2007Xing Xu Abstract In C3 plants, carbon isotope discrimination (,) has been proposed as an indirect selection criterion for grain yield. Reported correlations between , and grain yield however, differ highly according to the analyzed organ or tissue, the stage of sampling, and the environment and water regime. In a first experiment carried out in spring wheat during two consecutive seasons in the dry conditions of northwest Mexico (Ciudad Obregon, Sonora), different water treatments were applied, corresponding to the main water regimes available to spring wheat worldwide, and the relationships between , values of different organs and grain yield were examined. Under terminal (post-anthesis) water stress, grain yield was positively associated with , in grain at maturity and in leaf at anthesis, confirming results previously obtained under Mediterranean environments. Under early (pre-anthesis) water stress and residual moisture stress, the association between grain , and yield was weaker and highly depended on the quantity of water stored in the soil at sowing. No correlation was found between , and grain yield under optimal irrigation. The relationship between , and grain yield was also studied during two consecutive seasons in 20 bread wheat cultivars in the Ningxia region (Northern China), characterized by winter drought (pre-anthesis water stress). Wheat was grown under rainfed conditions in two locations (Guyuan and Pengyang) and under irrigated conditions in another two (Yinchuan and Huinong). In Huinong, the crop was also exposed to salt stress. Highly significant positive associations were found between leaf and grain , and grain yields across the environments. The relationship between , and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, the presence of salt in the soil, and the occurrence of irrigation before anthesis. These two experiments confirmed the value of , as an indirect selection criterion for yield and a phenotyping tool under post-anthesis water stress (including limited irrigation). [source] Efficacy of grass pollen sublingual immunotherapy for three consecutive seasons and after cessation of treatment: the ECRIT studyALLERGY, Issue 9 2009H. Ott Background:, Data supporting a carry-over effect with sublingual immunotherapy (SLIT) are scarce. This randomized, double-blind, placebo-controlled study evaluated the efficacy, carry-over effect and safety of grass pollen SLIT using co-seasonal treatment. Methods:, Patients (7.9,64.7 years) with grass pollen allergy received ultra-rush titration with increasing doses (30, 90, 150 and 300 IR) of a 5-grass pollen mixture every 20 min at the start of the pollen seasons, followed by 300 IR daily until the end of the pollen seasons. A baseline season (no SLIT) was followed by three consecutive treatment seasons and one follow-up season. Symptoms, medication and adverse events were documented and specific immunoglobulin (Ig)E and IgG4 measured. Results:, Data were analysed for 183 of the 213 randomized patients. Mean treatment duration varied between seasons (81.8,92.7 days). Combined scores (symptoms and medication) improved progressively across treatment seasons (up to 44.7% improvement for SLIT compared with baseline) and fluctuated between ,11.3% and ,14.8% for placebo (P < 0.05). Similar changes were observed for symptom scores, with a successive decrease of 39.7% (SLIT) and fluctuations between +13.6% and ,1.51% for placebo (P < 0.05). Combined score (P = 0.0508) and symptom score improvements (P = 0.0144) with SLIT continued during follow up. Increases in specific IgG4 observed in the first season were sustained for SLIT vs placebo throughout treatment (P = 0.0001). Titration and daily SLIT were well tolerated. No serious systemic or anaphylactic reactions were reported. Conclusions:, Seasonal SLIT with ultra-rush titration is well tolerated and effective from the first treatment season onwards. These data indicate a carry-over effect of seasonal SLIT. [source] Efficacy of grass pollen sublingual immunotherapy for three consecutive seasons and after cessation of treatment: the ECRIT studyALLERGY, Issue 1 2009H. Ott Background:, Data supporting a carry-over effect with sublingual immunotherapy (SLIT) are scarce. This randomized, double-blind, placebo-controlled study evaluated the efficacy, carry-over effect and safety of grass pollen SLIT using co-seasonal treatment. Methods:, Patients (7.9,64.7 years) with grass pollen allergy received ultra-rush titration with increasing doses (30, 90, 150 and 300 IR) of a 5-grass pollen mixture every 20 min at the start of the pollen seasons, followed by 300 IR daily until the end of the pollen seasons. A baseline season (no SLIT) was followed by three consecutive treatment seasons and one follow-up season. Symptoms, medication and adverse events were documented and specific immunoglobulin (Ig)E and IgG4 measured. Results:, Data were analysed for 183 of the 213 randomized patients. Mean treatment duration varied between seasons (81.8,92.7 days). Combined scores (symptoms and medication) improved progressively across treatment seasons (up to 44.7% improvement for SLIT compared with baseline) and fluctuated between ,11.3% and ,14.8% for placebo (P < 0.05). Similar changes were observed for symptom scores, with a successive decrease of 39.7% (SLIT) and fluctuations between +13.6% and ,1.51% for placebo (P < 0.05). Combined score (P = 0.0508) and symptom score improvements (P = 0.0144) with SLIT continued during follow up. Increases in specific IgG4 observed in the first season were sustained for SLIT vs placebo throughout treatment (P = 0.0001). Titration and daily SLIT were well tolerated. No serious systemic or anaphylactic reactions were reported. Conclusions:, Seasonal SLIT with ultra-rush titration is well tolerated and effective from the first treatment season onwards. These data indicate a carry-over effect of seasonal SLIT. [source] Effects of weather variables on grain mould of sorghum in South AfricaPLANT PATHOLOGY, Issue 2 2006G. Tarekegn Effects of weather variables of mould development on sorghum grain were studied over three consecutive seasons in South Africa. Five sorghum hybrids planted at different dates ensured developing seeds were exposed to different weather conditions. Incidence of grain mould fungi was determined at harvest by incubating seeds on 2% malt extract agar. Averages of different weather variables (maximum and minimum temperatures, maximum relative humidity, total precipitation and frequency of precipitation) were determined for all permutations of weekly time intervals for a 2-month postflowering period to identify when these variables and pathogen incidence were significantly correlated. Significant correlations were used to develop models to quantify relationships between variables. Significant positive correlations were observed between the incidence of mould fungi and weather 4,6 weeks after flowering in the shorter season hybrid cv. Buster, and 5,8 weeks after flowering in the remaining hybrids. In most hybrids, correlations between the incidence of grain mould pathogens, including Alternaria alternata, Curvularia spp. (C. lunata and C. clavata), Fusarium spp. (F. proliferatum and F. graminearum), and Drechslera sorghicola, and average minimum temperature, total rainfall and frequency of rainfall were significant (P = 0·05). In four hybrids, models showing a linear relationship between the logarithm of pathogen incidence and minimum temperature, and in one hybrid, between pathogen incidence and rainfall frequency, were developed. Depending on the hybrid, models that used minimum temperature as predictor described 60,82% of variation in the incidence of pathogens. Frequency of rainfall explained 93% of the variation in pathogen incidence in one sorghum hybrid genotype. Evaluation of the models using an independent data set yielded average prediction errors near zero, indicating that the models were acceptable. [source] Parasites of cultured and wild brown-marbled grouper Epinephelus fuscoguttatus (Forsskål, 1775) in Lampung Bay, IndonesiaAQUACULTURE RESEARCH, Issue 8 2010Sonja Rückert Abstract A total of 210 Epinephelus fuscoguttatus (brown-marbled grouper) was examined for parasites. During three consecutive seasons (two rainy and one dry season from 2002 to 2004), 35 specimens each taken from floating net cages of the National Sea Farming Development Centre (Balai Budidaya Laut) and from wild catches in Lampung Bay, South Sumatra, Indonesia were studied. Twenty-five (cultured grouper) and 30 (wild grouper) parasite species/taxa were identified, with an infracommunity ranging from one to nine (cultured) and three to 14 parasite species (wild), demonstrating a species-rich parasite fauna even in the cultured fish. Protozoans (1 species), microsporeans (1), myxozoans (1), digeneans (8), monogeneans (5), cestodes (3), nematodes (8), acanthocephalans (2) and crustaceans (6) were found. The most abundant parasites were the monogeneans Pseudorhabdosynochus epinepheli and Pseudorhabdosynochus lantauensis for both, cultured and wild grouper during all seasons. For the cultured fish, the prevalence of monoxenous ectoparasites (e.g. P. epinepheli, P. lantauensis, Capsalidae gen. et sp. indet., Benedenia epinepheli) was in most cases higher than that of heteroxenous endoparasites. This contrasts the wild grouper, where heteroxenous parasites such as Allopodocotyle epinepheli and Raphidascaris sp. occurred at a similar prevalence compared with the fairly abundant Pseudorhabdosynochus spp. No seasonality of infestation was observed for both cultured and wild fish. The high levels of infestation of potentially pathogenic monogeneans throughout the year could result in significant parasite outbreaks at the locality studied. [source] PCR detection of pirimicarb resistance in Australian field isolates of Aphis gossypii Glover (Aphididae: Hemiptera)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2009Martin O McLoon Abstract Aphis gossypii Glover (cotton aphid) is a major secondary pest of Australian cotton that readily develops resistance to the carbamate insecticide pirimicarb (Pirimor®) and to organophosphates generally. To test the pirimicarb resistance status of Australian strains of A. gossypii, a polymerase chain reaction (PCR) assay followed by restriction enzyme assay (REA) was designed to identify the AceI polymorphism S431F known to be responsible for resistance. The method was tested against reference and 33 field strains collected over two consecutive seasons. Both methods confirmed pirimicarb resistance in two field strains, one from each cotton season, giving credence to the molecular technique described. The PCR assay proved specific for the AceI gene. This PCR REA assay has the potential to replace bioassay for the routine pirimicarb resistance monitoring in A. gossypii. With the molecular assay providing results in 48 h, compared with 4,8 weeks for bioassay, such an assay could be used before insecticide control. [source] | |||||||||||||