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971.
Nakagawa (Am J Primatol 41:267–288, 1997) reported that both the gross energy and gross protein intakes of an adult female Japanese macaque (Macaca fuscata) on Kinkazan Island, northern Japan, were high in spring (March–May) and fall (September–November) and low in summer (June–August)
and winter (December–February), and that these values reflected the seasonal differences in nutritional conditions (defined
as whether the intakes of energy and protein satisfy the requirements). We estimated the energy balance (energy intake minus
its expenditure) and the protein balance (protein intake minus its requirement) of the monkeys on Kinkazan Island every month
over the course of 1 year (2004–2005) in order to verify Nakagawa’s conclusions. Like Nakagawa, we found that the energy balance
of the monkeys in the fall was higher than in the summer and winter, whereas the protein balance in the fall was higher than
in the winter. However, we did not find that spring energy and protein values were greater than summer and winter values.
We also did not find that summer protein values were low. Both the energy balance and the protein balance changed rapidly
within the same season. The energy intakes and the energy balances were higher in mid-spring and mid- and late fall and lower
in late spring and early summer, whereas the protein intakes and the protein balances were higher in mid-spring and mid-summer
and lower in early and mid-winter. Since Japanese macaques respond to seasonal changes in food supply by changing their foods,
continuous data collection with short intervals is recommended in order to accurately document the energy and protein balances
of the monkeys. 相似文献
972.
响应曲面法优化鼠尾藻中脂质的提取工艺 总被引:4,自引:0,他引:4
根据中心复合旋转设计原理,在单因素试验的基础上,采用三因素五水平的响应曲面分析法,建立了鼠尾藻中脂质提取的二次多项式数学模型,并以脂质的提取率为响应值作响应面和等高线,考察了提取时间、溶剂的量和石油醚乙醚溶剂配比对脂质提取的影响。结果表明:脂质提取的优化工艺条件为:提取时间19.39h,溶剂的量18.90mL,石油醚百分含量46.26%。在此工艺条件下,脂质的提取率为0.924%。 相似文献
973.
JÜRGEN KRIWET STEFANIE KLUG JOSÉ I. CANUDO GLORIA CUENCA‐BESCOS 《Zoological Journal of the Linnean Society》2008,154(2):278-290
Eoptolamna eccentrolopha gen. et sp. nov. (Chondrichthyes, Lamniformes) from the near coastal upper Barremian Artoles Formation (Early Cretaceous) of Castellote (northwestern Spain) is described on the basis of about 50 isolated teeth. This taxon represents one of the earliest lamniform sharks known to date. We hypothesize that most pre‐Aptian lamniforms belong to an ancient group characterized, amongst others, by a very weak gradient monognathic heterodont dental pattern, and by tearing‐type dentition. There is a nutritive groove in the lingual root protuberance in juveniles of Eoptolamna, which persists in adults. A single pair of symphysial and a pair of upper intermediate teeth might have been present. Consequently, a new family, Eoptolamnidae, is introduced to include the new form, as well as Protolamna and probably Leptostyrax. The Eoptolamnidae represent an ancient family within Lamniformes. The origin of lamniform sharks remains, however, ambiguous despite recent advances. The new Spanish taxon is widespread in the Barremian of north‐eastern Spain, and occurs in a wide range of facies from near‐coastal to lake deposits. This lamniform also occurs in the Lower Cretaceous of northern Africa. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 278–290. 相似文献
974.
ANNETTE BAATTRUP-PEDERSEN GUNTA SPRINGE TENNA RIIS SØREN E. LARSEN KAJ SAND-JENSEN LARS M. KJELLERUP LARSEN 《Freshwater Biology》2008,53(9):1890-1901
1. The European Water Framework Directive provides a framework for improving the ecological quality of stream ecosystems, with deviation from reference used as a measure of ecological status.
2. Here we examine the possibility of using less impacted stream sites from Latvia, Lithuania and Poland to establish a Danish reference network for macrophyte assemblages, and as a guiding image for identification of possible references sites within Denmark. Both approaches were evaluated using historical Danish records.
3. Four different macrophyte assemblages were identified for mid-sized streams in the Central and Eastern Lowland ecoregions. Macrophyte assemblages could not be delineated using physical stream site characteristics; however a gradual change in assemblage composition was attributed to differences in alkalinity and human impact.
4. Assemblages of contemporary vegetation in Denmark were quite similar to those found in Polish, Latvian and Lithuanian streams (26–35%). However, more importantly, from species-based predictions we noted higher similarity, particularly with Latvian and Lithuanian streams, before intensive land use commenced in Denmark ( c. 1900). These results show that stream sites from these three countries can be considered in a Danish reference network.
5. Two of the four macrophyte assemblages comprised species such as Fontinalis antipyretica, Myriophyllum spicatum , Nuphar lutea , Potamogeton alpinus and P. perfoliatus that have a very scattered occurrence in the contemporary vegetation in Denmark. These groups were closely associated with the predictions from historic records, thereby lending support the conjecture that these assemblages could be part of the guiding image for the identification of potential reference sites within Denmark. 相似文献
2. Here we examine the possibility of using less impacted stream sites from Latvia, Lithuania and Poland to establish a Danish reference network for macrophyte assemblages, and as a guiding image for identification of possible references sites within Denmark. Both approaches were evaluated using historical Danish records.
3. Four different macrophyte assemblages were identified for mid-sized streams in the Central and Eastern Lowland ecoregions. Macrophyte assemblages could not be delineated using physical stream site characteristics; however a gradual change in assemblage composition was attributed to differences in alkalinity and human impact.
4. Assemblages of contemporary vegetation in Denmark were quite similar to those found in Polish, Latvian and Lithuanian streams (26–35%). However, more importantly, from species-based predictions we noted higher similarity, particularly with Latvian and Lithuanian streams, before intensive land use commenced in Denmark ( c. 1900). These results show that stream sites from these three countries can be considered in a Danish reference network.
5. Two of the four macrophyte assemblages comprised species such as Fontinalis antipyretica, Myriophyllum spicatum , Nuphar lutea , Potamogeton alpinus and P. perfoliatus that have a very scattered occurrence in the contemporary vegetation in Denmark. These groups were closely associated with the predictions from historic records, thereby lending support the conjecture that these assemblages could be part of the guiding image for the identification of potential reference sites within Denmark. 相似文献
975.
976.
Natural selection on the genetical component of variance in body condition in a wild bird population
Although there is substantial evidence that skeletal measures of body size are heritable in wild animal populations, it is frequently assumed that the nonskeletal component of body weight (or ‘condition’) is determined primarily by environmental factors, in particular nutritional state. We tested this assumption by quantifying the genetic and environmental components of variance in fledgling body condition index (=relative body weight) in a natural population of collared flycatchers (Ficedula albicollis), and compared the strength of natural selection on individual breeding values with that on phenotypic values. A mixed model analysis of the components of variance, based on an ‘animal model’ and using 18 years of data on 17 717 nestlings, revealed a significant additive genetic component of variance in body condition, which corresponded to a narrow sense heritability (h2) of 0.30 (SE=0.03). Nongenetic contributions to variation in body condition were large, but there was no evidence of dominance variance nor of contributions from early maternal or common environment effects (pre‐manipulation environment) in condition at fledging. Comparison of pre‐ and post‐selection samples revealed virtually identical h2 of body condition index, despite the fact that there was a significant decrease (35%) in the levels of additive genetic variance from fledging to breeding. The similar h2 in the two samples occurred because the environmental component of variance was also reduced by selection, suggesting that natural selection was acting on both genotypic and environmental variation. The effects of selection on genetic variance were confirmed by calculation of the selection differentials for both phenotypic values and best linear unbiased predictor (BLUP) estimates of breeding values: there was positive directional selection on condition index both at the phenotypic and the genotypic level. The significant h2 of body condition index is consistent with data from human and rodent populations showing significant additive genetic variance in relative body mass and adiposity, but contrasts with the common assumption in ecology that body condition reflects an individual’s nongenetic nutritional state. Furthermore, the substantial reduction in the additive genetic component of variance in body condition index suggests that selection on environmental deviations cannot alone explain the maintenance of additive genetic variation in heritable traits, but that other mechanisms are needed to explain the moderate to high heritabilities of traits under consistent and strong directional selection. 相似文献
977.
雨生红球藻营养细胞的虾青素累积 总被引:18,自引:0,他引:18
接种于缺氮培养基的雨生红球藻。当置于光强为10—12klx,温度25℃±1.5℃条件下培养时,营养细胞迅速由绿色变成红色。接种4d时,运动细胞占细胞总数的90%,细胞内的虾青素含量(33.0pg/cell)占最终色素累积量的(60.0pg/cell)的55%。接种6d时,虾青素含量已占最终累积量的75%。电镜观察显示,红色的运动细胞除细胞质的大部分区域充满色素颗粒外,细胞的形态结构与绿色细胞基本一致。实验还表明,当接种物置于低光(0.5—1.0klx)下培养时,营养细胞仍有色素沉积,但累积缓慢。当只有高光胁迫(10—12klx,完全培养基培养)时,营养细胞转变成厚壁孢子后(5d后),才大量积累色素。 相似文献
978.
国外松衰退病与环境和林分因素关系的研究 总被引:1,自引:0,他引:1
对安徽国外要公衰退病与其环境和林分因素关系的调查研究和数量化分析表明,在气候、土壤、林分、其它病虫害等4类因素18个变量因子中,有10个因子对病情有较大的贡献,成为该病发生的主要致病因素,它们是树龄、林分密度、割脂、降雨量、温度、粘性土、石砾土、土层瘠薄、积水、病虫危害,其中病情与土层浓度、降雨量呈负相关;与其它因素均呈正相关,以此建立病情线形回归预测模型,根据这一模型,可以预测任一给定条件下的林分国外松衰退病可能发生的水平,此外,依据各致病因素在病害发生发展过程中的作用大小和时间顺序,出国外松衰退病的螺旋图,为该类病原复杂的病害形象描述和定量分析作出了探讨。 相似文献
979.
Abstract. Vegetation samples from 15 successional seres in various disturbed habitats in the western part of the Czech Republic were analysed to detect possible trends. For particular seres, data on species cover were available from the onset to 10–76 yr of succession. All seres started on bare ground. Species which attained at least 1% cover in any sere in any year were used as input data for Canonical Correspondence Analysis, assessing the effect of time as the environmental variable, for Detrended Correspondence Analysis and TWINSPAN classification. Two distinct groups ofseres were distinguished: ‘ruderal’, occurring in agricultural, industrial or urban landscapes altered by men, usually on fertile sites; and ‘non‐ruderul’, occurring in less altered, mostly forested landscapes, usually on acid, nutrient‐poor and wetter soils. The former type of succession starts with ruderal annuals, being followed by ruderal perennials. In the latter case non‐ruderal clonal perennials prevail from the onset of succession. The landscape frame is emphasized, beside site environmental conditions, as influencing the type of succession. The character of species attaining dominance in succession, participation of dominant woody plants and the character of late successional stages, i.e. features important from the point of view of potential restoration of human‐disturbed habitats, are discussed. 相似文献
980.
The intermediate metabolites of benzene transformation by a microaerophilic bacterial consortium, adapted to degrade gasoline and benzene at low concentrations of dissolved oxygen (<1 mg l-1), were identified. The examined range of initial DO concentration, 0.05 to 1 mg l-1, was considerably lower than the previously reported values believed to be necessary to initiate benzene biodegradation. An extensive transformation of benzene, higher than the theoretical predictions for its aerobic oxidation, was observed. Phenol was identified as the most stable and the major intermediate metabolite which was subsequently transformed into catechol and benzoate. The use of 13C-labeled compounds identified benzene as the source of phenol, and phenol as the source of catechol and benzoate, suggesting the involvement of a monooxygenase enzymatic system in biodegradation of benzene at low DO concentrations. A metabolic sequence was proposed to describe the simultaneous detection of catechol and benzoate during the microaerophilic transformation of benzene. The results of this work demonstrate that it is possible to transform benzene, a highly carcinogenic hydrocarbon and a major contaminant of groundwater, to more easily biodegradable compounds in the presence of very small amounts of oxygen. 相似文献