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1.
This paper deals with the ethnobotany of the Onge tribe. Brief accounts of the geography of the island, ethnology, and history of ethnobotanical studies in addition to the methodology of the present work are given. Plants used in everyday life, such as for bows and arrows, dugouts and canoes, fibers, food, medicines, and shelter, are described and discussed. The 40 species dealt with in the paper have 52 uses. The present study indicates that the Onge tribe shows certain similarities with other southeastern Asian Negrito races.  相似文献   

2.
This paper deals with ethnobotany of the Great Andamanese tribe. Brief accounts of Andaman geography, ethnology, and previous ethnobotanical studies are given. Plants used in everyday life, such as for bows and arrows, canoes, fibers, food, medicines, rituals, musical instruments, tools, and shelter, are described and discussed. Scientific and vernacular names, uses, and ethnobotanical importance are listed.  相似文献   

3.
Recently measured water permeability through bilayers of different lipids is most strongly correlated with the area per lipid A rather than with other structural quantities such as the thickness. This paper presents a simple three-layer theory that incorporates the area dependence in a physically realistic way and also includes the thickness as a secondary modulating parameter. The theory also includes the well-known strong correlation of permeability upon the partition coefficients of general solutes in hydrocarbon environments (Overton's rule). Two mathematical treatments of the theory are given; one model uses discrete chemical kinetics and one model uses the Nernst-Planck continuum equation. The theory is fit to the recent experiments on water permeability in the accompanying paper.  相似文献   

4.
This paper describes the design of a recording echo sounder which has a depth range of 6 m and can be used in shallow lakes and rivers to determine submerged plant heights and water depths. The instrument uses mainly digital techniques, has a liquid crystal display, and records echoes on standard audio cassettes. These are returned to the laboratory for analysis, using a microcomputer to produce various maps of the data. This system has been successfully used to map plant populations at several sites, the data for which are given.  相似文献   

5.
1. Details of an improved method for starch-gel electrophoresis of water-soluble muscle proteins are given. 2. Methods are described for detecting enzyme activities on the starch gel after electrophoresis, by using pieces of filter paper. 3. Compositions of incubation mixtures suitable for detecting any of the enzymes of glycolysis, and certain other enzymes, are given. 4. A comparison of the various enzymes in extracts of several muscles from one rabbit was made; most differences are quantitative only. 5. A detailed comparison of the mobilities of various enzymes in extracts of muscles from a wide variety of species was made. Each species was found to have a characteristic pattern of proteins on the starch gel, and the mobilities of individual enzymes varied considerably. 6. Potential uses and extensions of the methods are discussed.  相似文献   

6.
In this paper we describe a new heuristic strategy designed to find optimal (parsimonious) trees for data sets with large numbers of taxa and characters. This new strategy uses an iterative searching process of branch swapping with equally weighted characters, followed by swapping with reweighted characters. This process increases the efficiency of the search because, after each round of swapping with reweighted characters, the subsequent swapping with equal weights will start from a different group (island) of trees that are only slightly, if at all, less optimal. In contrast, conventional heuristic searching with constant equal weighting can become trapped on islands of suboptimal trees. We test the new strategy against a conventional strategy and a modified conventional strategy and show that, within a given time, the new strategy finds trees that are markedly more parsimonious. We also compare our new strategy with a recent, independently developed strategy known as the Parsimony Ratchet.  相似文献   

7.
8.
To adapt to the environment and survive, most animals can control their behaviors by making decisions. The process of decision-making and responding according to cues in the environment is stable, sustainable, and learnable. Understanding how behaviors are regulated by neural circuits and the encoding and decoding mechanisms from stimuli to responses are important goals in neuroscience. From results observed in Drosophila experiments, the underlying decision-making process is discussed, and a neural circuit that implements a two-choice decision-making model is proposed to explain and reproduce the observations. Compared with previous two-choice decision making models, our model uses synaptic plasticity to explain changes in decision output given the same environment. Moreover, biological meanings of parameters of our decision-making model are discussed. In this paper, we explain at the micro-level (i.e., neurons and synapses) how observable decision-making behavior at the macro-level is acquired and achieved.  相似文献   

9.
Suicide research has relied heavily on the psychological autopsy method, which uses interviews with the bereaved to ascertain the mental health status of the deceased prior to death. The resulting data are typically interpreted within a clinical diagnostic framework, which reinforces psychiatric assumptions concerning the ubiquity of mental illness amongst those who take their own lives. The ways in which informants reconstruct the past and the meanings they attach to events preceding the suicide are rarely examined. This paper uses qualitative methods to analyse the narratives given by bereaved people in an English psychological autopsy study, in order to understand how they made sense of a family member's suicide. Some clear differences between the portrayal of male and female suicides emerged. The paper discusses the gendering of agency and accountability in relation to the differential medicalisation of male and female distress in the UK, and suggests that a preoccupation with mental illness in suicide research may have obscured other culturally normative understandings of self-accomplished death.  相似文献   

10.
A pneumatically-operated water sampler for close intervals of depth   总被引:4,自引:0,他引:4  
A pneumatically-operated sampler for collecting water samples at close intervals of depth in lakes is described. The sampler uses plastic disposable syringes and may be operated at various depths and at the mud-water interface. Examples of results obtained with the sampler are given.  相似文献   

11.
Mammalian basal metabolic rates (BMR) increase with body mass, whichs explains approximately 95% of the variation in BMR. However, at a given mass, there remains a large amount of variation in BMR. While many researchers suggest that the overall scaling of BMR with body mass is due to physiological constraints, variation at a given body mass may provide clues as to how selection acts on BMR. Here, we examine this variation in BMR in a broad sample of mammals and we test the hypothesis that, across mammals, body composition explains differences in BMR at a given body mass. Variation in BMR is strongly correlated with variation in muscle mass, and both of these variables are correlated with latitude and ambient temperature. These results suggest that selection alters BMR in response to thermoregulatory pressures, and that selection uses muscle mass as a means to generate this variation.  相似文献   

12.
世界上可以用海水灌溉的盐生植物资源   总被引:12,自引:0,他引:12  
赵可夫  范海 《植物学通报》2000,17(3):282-288
报道了世界上可以利用海水灌溉的盐生植物种类及其生活型 、植物类型、分布、光合途径、耐盐水平和用途。此类植物有168种,分属32科,一些用途不明的布盐能力达到适应海水的植物没有列入,例如粉藻科、眼有科、水龟科等,约有60余种。  相似文献   

13.
激光时间分辨荧光谱仪*以及荧光各向异性测量   总被引:1,自引:0,他引:1  
就时间相关单光子计数荧光谱仪的工作原理、实验装置的建立等问题进行了探讨。利用国产的红离子锁模激光同步泵浦腔倒空输出染料激光器等器件与进口的时幅转换器、定时恒分器建成了激光时间分辨荧光谱仪,时间分辨率为80ps。本文还建立了荧光各向异性的测量方法,利用该方法对R-PE的旋转弛豫时间进行了测量,并与英国Edinburgh公司生产的299T型荧光谱仪的测量结果进行了比较,结果证明仪器及方法都是可靠的。  相似文献   

14.
The paper describes the local, national, European and wider-area framework, statutes, and formal and voluntary mechanisms for managing European estuaries. These aspects are discussed in relation to two large and representative estuarine systems, the Tagus, Portugal, and the Humber, on the English North Sea coast As estuaries are sites of many activities and uses, most of which are encouraged or at least condoned, management has the role of preventing and resolving conflicts between those uses and users. Accepted uses of estuaries include the discharge and dumping of waste materials, fin and shell-fisheries, conservation, land reclamation, natural usage, abstraction by industry, and recreation. Estuarine management is now being carried out within the constraints of local and regional government planning, planning and activities of water pollution control bodies, fisheries control bodies, and navigation and port authorities The Tagus and Humber estuaries support all of the above activities and uses, and have controls within a European legislative framework but have differing histories of management and planning in order to resolve conflicts. In addition the Humber is subject to controls placed on North Sea areas. The paper discusses the relevant national and European legislation (Directives) and accepted practices for management. Furthermore, the paper discusses the formulation and practice of estuarine management plans as used by various bodies (nature conservation, water quality and regional authority). It is of particular note that the lessons from these two estuaries are relevant to many other European estuaries.  相似文献   

15.
The dynamic organization of the human genome in the nucleus is gaining recognition as a determining factor in its functional regulation. In order to be expressed, replicated or repaired, a genomic locus has to be present at the right place at the right time. In the present study, we have investigated the choice of a double-strand break (DSB) repair partner for a given genomic loci in an ATM-deficient human fibroblast cell line. We found that partner choice is restricted such that a given genomic locus preferentially uses certain sites in the genome to repair itself. These preferential sites can be in the vicinity of the damage site or megabases away or on other chromosomes entirely, while potential sites closer to the break along the length of the chromosome can be ignored. Moreover, there can be more than a 10-fold difference in usage between repair sites located only 10 kb apart. Interestingly, arms of a given chromosome are less accessible to one another than to other chromosomes. Altogether, these results indicate that the accessibility between genomic sites in the human genome during DSB repair is specific and conserved in a cell population.  相似文献   

16.
The two-hybrid system uses the efficacy of yeast genetic assays to identify protein-protein interactions. It permits the rapid cloning of genes encoding products that interact with a given protein of interest. Also being developed are phage display methods that allow direct physical selection of binding proteins. These methods have significantly altered strategies for analysing signaling and regulatory pathways.  相似文献   

17.
This paper presents a list of some medicinal plants distributed in the East Anatolia region. The list was prepared during an ethnobotanical survey of the region from 1995 to 2002. East Anatolia has a rich flora due to its variable climate and its many ecological zones. This diversity in flora provides a rich source of medicinal plants that has been long utilized by Anatolian cultures; and hence, accounts for the remarkable accumulation of medicinal folk knowledge for the region. This paper provides information about 71 useful plants grown in the region, 20 of which are reported for the first time. In addition to the scientific names, vernacular names and medicinal uses are given for each plant.  相似文献   

18.
Paul Sillitoe 《Ethnos》2013,78(3):365-393
The animals of the Papua New Guinea highlands are relatively defenceless. People not only value their meat, hunters sharing catch with kin, but also formally transact several creatures in the all-important socio-political exchanges that characterise their social life. The local sedentary population is dense, yet it has not hunted species to extinction regardless of their value and vulnerability to predation. This paper seeks an answer in the context of socio-political exchange values that inform social status. It uses data from a survey of animal skull trophies displayed in a sample of houses in the Was valley of the Southern Highlands Province to investigate connections between hunting and social standing - exchange status, kin group affiliation and age - with a view to elucidating tacit conservation behaviour which agencies concerned to protect biodiversity might profitably consider given current participatory rhetoric.  相似文献   

19.
A technique for differentiating high-resolution NMR signals from different regions of small objects is outlined and some initial results on model systems are given. This method uses inorganic paramagnetic or diamagnetic ions to create magnetic field gradients at phase boundaries.  相似文献   

20.
The purpose of this paper is to present a simple new method for calculating the opening angle produced by a given residual stress field in a soft biological tissue. The method uses minimization of potential energy, and is therefore named the MPE method. The accuracy of the MPE method is evaluated by comparing the opening angle it predicts to results from a finite element model of the opening angle experiment. We show that the MPE method provides good predictions of the opening angle, and that it is significantly more accurate than two other methods previously used in the literature.  相似文献   

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