Alternative models of cardiac rehabilitation : a systematic review

The traditional hospital-based model of cardiac rehabilitation faces substantial challenges, such as cost and accessibility. These challenges have led to the development of alternative models of cardiac rehabilitation in recent years. The aim of this study was to identify and critique evidence for the effectiveness of these alternative models. A total of 22 databases were searched to identify quantitative studies or systematic reviews of quantitative studies regarding the effectiveness of alternative models of cardiac rehabilitation. Included studies were appraised using a Critical Appraisal Skills Programme tool and the National Health and Medical Research Council's designations for Level of Evidence. The 83 included articles described interventions in the following broad categories of alternative models of care: multifactorial individualized telehealth, internet based, telehealth focused on exercise, telehealth focused on recovery, community- or home-based, and complementary therapies. Multifactorial individualized telehealth and community- or home-based cardiac rehabilitation are effective alternative models of cardiac rehabilitation, as they have produced similar reductions in cardiovascular disease risk factors compared with hospital-based programmes. While further research is required to address the paucity of data available regarding the effectiveness of alternative models of cardiac rehabilitation in rural, remote, and culturally and linguistically diverse populations, our review indicates there is no need to rely on hospital-based strategies alone to deliver effective cardiac rehabilitation. Local healthcare systems should strive to integrate alternative models of cardiac rehabilitation, such as brief telehealth interventions tailored to individual's risk factor profiles as well as community- or home-based programmes, in order to ensure there are choices available for patients that best fit their needs, risk factor profile, and preferences.

Review of the nutrition policy of the Arnhem Land Progress Association

The process of implementation and the effect of the nutrition policy of the Arnhem Land Progress Association (ALPA) were reviewed three years after implementation of the policy in five remote Aboriginal community retail stores in May 1990. In 1993, compliance with the policy varied among stores. Recommended foods were available regularly in most communities; however, promotional and educational components of the policy were not widely implemented. Dietary improvements were evident in those communities where stores most complied with the policy. Some aspects of the ALPA nutrition policy require modification, and renewed commitment to the policy is likely to improve further the diet in the Aboriginal communities involved. The ALPA nutrition policy is a potential model for the development of other local food and nutrition policies in remote Aboriginal communities.

Supermarkets and private standards : unintended consequences of the audit ritual

Recent scholarship has considered the implications of the rise of voluntary private standards in food and the role of private actors in a rapidly evolving, de-facto ‘mandatory’ sphere of governance. Standards are an important element of this globalising private sphere, but are an element that has been relatively peripheral in analyses of power in agri-food systems. Sociological thought has countered orthodox views of standards as simple tools of measurement, instead understanding their function as a governance mechanism that transforms many things, and people, during processes of standardisation. In a case study of the Australian retail supermarket duopoly and the proprietary standards required for market access this paper foregrounds retailers as standard owners and their role in third-party auditing and certification. Interview data from primary research into Australia’s food standards captures the multifaceted role supermarkets play as standard-owners, who are found to impinge on the independence of third-party certification while enforcing rigorous audit practices. We show how standard owners, in attempting to standardize the audit process, generate tensions within certification practices in a unique example of ritualism around audit. In examining standards to understand power in contemporary food governance, it is shown that retailers are drawn beyond standard-setting into certification and enforcement, that is characterized by a web of institutions and actors whose power to influence outcomes is uneven.

A comparative analysis of relevant crop carbon footprint calculators, with reference to cotton production in Australia

An increasing concern over the sustainability credentials of food and fiber crops require that farmers and their supply chain partners have access to appropriate and industry-friendly tools to be able to measure and improve the outcomes. This article focuses on one of the sustainability indicators, namely, greenhouse gas (GHG) emissions, and nine internationally accredited carbon footprint calculators were identified and compared on an outcomes basis against the same cropping data from a case study cotton farm. The purpose of this article is to identify the most “appropriate” methodology to be applied by cotton suppliers in this regard. From the analysis of the results, we subsequently propose a new integrated model as the basis for an internationally accredited carbon footprint tool for cotton and show how the model can be applied to evaluate the emission outcomes of different farming practices.

Eating for health and the environment: Australian regulatory responses for dietary change

The Australian food system significantly contributes to a range of key environmental issues including harmful greenhouse gas emissions, air pollution, soil desertification, biodiversity loss and water scarcity. At the same time, the Australian s food system is a key cause of public health nutrition issues that stem from the co-existence of over- and under-consumption of dietary energy and nutrients. Within these challenges lie synergies and opportunities because a diet that has a lower environmental impact generally aligns with good nutrition. Australian State and Federal initiatives to influence food consumption patterns focus on individual body weight and ‘soft law’ interventions. These regulatory approaches, by focusing on select symptoms of food system failures, are fragmented, reductionist and inefficient. In order to illustrate this point, this paper will explore Australian regulatory responses to diet-related illnesses. The analysis will support the argument that only when regulatory responses to diets become embedded within reform of the current food system will substantial improvements to human and planetary health be achieved.

The Genetic Architecture of Climatic Adaptation of Tropical Cattle

Adaptation of global food systems to climate change is essential to feed the world. Tropical cattle production, a mainstay of profitability for farmers in the developing world, is dominated by heat, lack of water, poor quality feedstuffs, parasites, and tropical diseases. In these systems European cattle suffer significant stock loss, and the cross breeding of taurine x indicine cattle is unpredictable due to the dilution of adaptation to heat and tropical diseases. We explored the genetic architecture of ten traits of tropical cattle production using genome wide association studies of 4,662 animals varying from 0% to 100% indicine. We show that nine of the ten have genetic architectures that include genes of major effect, and in one case, a single location that accounted for more than 71% of the genetic variation. One genetic region in particular had effects on parasite resistance, yearling weight, body condition score, coat colour and penile sheath score. This region, extending 20 Mb on BTA5, appeared to be under genetic selection possibly through maintenance of haplotypes by breeders. We found that the amount of genetic variation and the genetic correlations between traits did not depend upon the degree of indicine content in the animals. Climate change is expected to expand some conditions of the tropics to more temperate environments, which may impact negatively on global livestock health and production. Our results point to several important genes that have large effects on adaptation that could be introduced into more temperate cattle without detrimental effects on productivity.

Lihaluujauhon soveltuvuus sokerijuurikkaan lannoitteeksi

Lihaluujauho muodostaa maatilojen myytävien kasvi- ja eläinperäisten tuotteiden jälkeen tärkeimmän agroekosysteemeistä poispäin suuntautuvan ravinnevirran. Se sisältää runsaasti pääkasvinravinteita typpeä, fosforia ja kalsiumia (N ~8%, P ~5%, Ca yleensä ~10-15% luuaineksen määrästä riippuen), sekä kaliumia n.1% tai alle. Lihaluujauho on todettu tehokkaaksi lannoitteeksi useilla viljelykasveilla ja sen käyttö on sallittu myös luomuviljelyssä EU-alueella. Lihaluujauhoon ja erityisesti sen rehukäyttöön liittyvistä riskeistä merkittävin on TSE-tautien riski (naudan BSE-, lampaiden ja vuohien scrapie-, sekä ihmisen vCJD-taudit). Rehukäyttöä on monissa maissa rajoitettu 1980-luvulla puhjenneen BSE-kriisin myötä. BSE-taudin leviäminen yhdistettiin tilanteeseen, jossa nautaperäistä lihaluujauhoa käytettiin nautaeläinten rehun ainesosana. Myös lihaluujauhon käytössä turkiseläinrehuna saattaa piillä BSE:n tai muun TSE-taudin riski. Oikein käsitellyn lihaluujauhon lannoitekäyttöön ei kuitenkaan näytä tarkastelemieni tutkimusten perusteella sisältyvän huomattavaa TSEriskiä, jos huolehditaan asianmukaisista varotoimista ja menettelyistä sekä tuotteen valmistusprosessissa, että käytettäessä lannoitetta. Lihaluujauhon lannoitekäytön lisääminen edistäisi ruokajärjestelmämme ravinnekierron sulkemista etenkin fosforin osalta. Lihaluujauho on uusiutuva luonnonvara, jonka lannoitekäytöllä voitaisiin korvata huomattava osa lannoiteaineena kulutettavista fosforipitoisista kiviaineista. Sokerijuurikkaan lannoituskokeissa Varsinais-Suomen Kaarinassa vuosina 2008 ja 2009 lihaluujauhokäsittelyt eivät menestyneet aivan yhtä hyvin satotasovertailussa kuin kontrollikäsittelyiden NPK-väkilannoitteet, mutta laatuominaisuuksiltaan (sokeripitoisuus, amino-N, K, ja Na-pitoisuudet) joiltakin osin kontrollikäsittelyjä paremmin. Kokeissa käytetyt lajikkeet olivat ’Jesper’ vuonna 2008 ja ’Lincoln’ vuonna 2009. Käytetty lihaluujauholannoite oli Honkajoki Oy:n Viljo Yleislannoite 8-4-3, joka sisälsi noin 10% kaliumsulfaatin ja kasviperäisten sivutuotteiden seosta. Viljo-lannoitetta käytettiin sekä yksistään, että yhdistettynä 10-25%:iin väkilannoitetta. Vuoden 2009 Viljo-koejäseniin vielä lisättiin kaliumsulfaattilannoitetta (42% K, 18% S), jotta päästiin annetun kaliumin määrässä päästiin lannoitussuosituksen (60 kg K/ha) tasolle. Pelkkä Viljo-lannoite tuotti merkitsevästi alhaisemmat sadot kuin kontrollikäsittelyt molempina vuosina. Kuitenkin kun Viljolannoitteen ohella käytettiin väkilannoitetta (10-25% kasvin typentarpeesta) päästiin varsin lähelle kontrollikäsittelyiden satotasoja. Myös pelkän LLJ-lannoitteen tuottamat satotasot olivat kuitenkin selvästi paremmat kuin Suomen keskimääräiset juurikassadot. Viljo-käsittelyillä oli selvästi positiivinen vaikutus laatutekijöihin amino-N, K ja Na vuonna 2008, mutta vuonna 2009 näiden pitoisuudet jäivät kontrollikäsittelyjen tasolle. Viljo-käsittelyiden sokeripitoisuudet olivat vuonna 2008 kontrollikäsittelyn luokkaa ja Viljo77%+NK1:n osalta kontrollia merkitsevästi paremmat. Vuoden 2009 sokeripitoisuudet olivat kaikilla koejäsenillä erinomaiset, ja käsittelyiden välillä ei ilmennyt merkitseviä eroja. Kokeiden perusteella kaliumsulfaatilla täydennetty lihaluujauho on hyvin toimiva lannoite sokerijuurikkaalla Suomen olosuhteissa, etenkin yhdistettynä väkilannoitteeseen.

Suomalaisen alkuperäiskarjan liha – kuluttajien osto- ja maksuhalukkuus

Tutkielman tavoitteena on selvittää suomalaisen alkuperäiskarjan lihan potentiaalista kysyntää. Alkuperäiskarjan lihan erikoistuotemarkkinat voivat auttaa pitämään uhanalaiset, kotimaiset karjarodut tuotantokäytössä. Näin ollen erikoistuotemarkkinat voivat auttaa arvokkaiden suomalaisten eläingeenivarojen säilyttämisessä. Koska alkuperäiskarjan lihan tuotannon kannattavuus riippuu lihasta saatavasta lisähinnasta, tutkimuksen tavoitteena on myös tutkia, millainen kuluttajien maksuhalukkuus alkuperäiskarjan lihasta on verrattuna tavanomaiseen lihaan. Tutkimusaineisto kerättiin Maa- ja elintarviketalouden tutkimuskeskuksen ja Kuluttajatutkimuskeskuksen suunnittelemalla kyselytutkimuksella keväällä 2010. Tutkimuksessa käytettiin ehdollisen käyttäytymisen ja ehdollisen arvottamisen menetelmiä ja sen otoskoko on 1623. Kuluttajien ostohalukkuutta ja siihen vaikuttavia tekijöitä tutkittiin sekä binäärisen että ordinaalisen regression malleilla. Kuluttajien maksuhalukkuutta alkuperäiskarjan lihasta ja siihen vaikuttavia tekijöitä tutkittiin grouped data -mallin avulla. Malleissa käytettiin selittävinä muuttujina sosioekonomisten muuttujien lisäksi kuluttajien asenteita ja käyttäytymistä kuvaavia muuttujia. Tutkielman tulosten mukaan jopa 86 % vastaajista ostaisi alkuperäiskarjan lihaa, jos sitä olisi tarjolla kaupoissa. Ostohalukkuutta lisää muun muassa, jos vastaajalla on alle 18-vuotiaita lapsia ja vastaaja arvostaa lähellä tuotettua, paikallista ruokaa sekä ympäristöystävällisyyttä. Miehet ostaisivat alkuperäiskarjan lihaa todennäköisemmin kuin naiset. Suurin osa vastaajista ostaisi alkuperäiskarjan lihaa, jos se olisi samanhintaista kuin tavanomainen liha, mutta noin neljäsosa (23,5 %) vastaajista olisi valmis maksamaan alkuperäiskarjan lihasta korkeampaa hintaa kuin tavanomaisesta lihasta. Maksuhalukkuuteen vaikuttivat positiivisesti muun muassa kuuluminen ympäristöjärjestöön ja korkea tulotaso. Negatiivisesti vaikutti puolestaan esimerkiksi se, että vastaaja on nainen. Keskimääräinen maksuhalukkuus alkuperäiskarjan lihasta oli 6,25 % korkeampi kuin tavanomaisesta lihasta. Maksuhalukkuus alkuperäiskarjan lihasta oli selvästi yhteydessä siihen, kuinka usein vastaaja olisi halukas ostamaan sitä. Maksuhalukkuus oli korkein niillä vastaajilla, jotka haluaisivat ostaa lihaa säännöllisesti.

GLOBAL REGISTRATION OF MULTIPLE POINT CLOUDS USING SEMIDEFINITE PROGRAMMING

Consider N points in R-d and M local coordinate systems that are related through unknown rigid transforms. For each point, we are given (possibly noisy) measurements of its local coordinates in some of the coordinate systems. Alternatively, for each coordinate system, we observe the coordinates of a subset of the points. The problem of estimating the global coordinates of the N points (up to a rigid transform) from such measurements comes up in distributed approaches to molecular conformation and sensor network localization, and also in computer vision and graphics. The least-squares formulation of this problem, although nonconvex, has a well-known closed-form solution when M = 2 (based on the singular value decomposition (SVD)). However, no closed-form solution is known for M >= 3. In this paper, we demonstrate how the least-squares formulation can be relaxed into a convex program, namely, a semidefinite program (SDP). By setting up connections between the uniqueness of this SDP and results from rigidity theory, we prove conditions for exact and stable recovery for the SDP relaxation. In particular, we prove that the SDP relaxation can guarantee recovery under more adversarial conditions compared to earlier proposed spectral relaxations, and we derive error bounds for the registration error incurred by the SDP relaxation. We also present results of numerical experiments on simulated data to confirm the theoretical findings. We empirically demonstrate that (a) unlike the spectral relaxation, the relaxation gap is mostly zero for the SDP (i.e., we are able to solve the original nonconvex least-squares problem) up to a certain noise threshold, and (b) the SDP performs significantly better than spectral and manifold-optimization methods, particularly at large noise levels.

Diário da Câmara dos Deputados : uma proposta de requisitos de organização e arquitetura da informação para a representação da informação na Biblioteca Digital da Câmara dos Deputados

Pretende verificar a conveniência do armazenamento do Diário da Câmara dos Deputados na Biblioteca Digital da Câmara dos Deputados, com vistas à recuperação do seu conteúdo informacional. A revisão de literatura ressalta a importância do DCD como fonte oficial de publicidade das atividades parlamentares, bem como traz a fundamentação da Biblioteca Digital como repositório institucional e ferramenta importante para apoiar a organização e recuperação da informação bibliográfica na Câmara dos Deputados. O objetivo geral do estudo consistiu em propor um conjunto de metadados de descrição física e temática como requisitos para a organização e representação dos conteúdos informacionais do DCD. A metodologia utilizada permitiu, além do embasamento teórico, a análise dos sistemas de informação da Casa Legislativa, os conteúdos do Diário e, por meio da aplicação de questionário, verificar a visão dos usuários da Coordenação de Relacionamento, Pesquisa e Informação sobre a recuperação das informações do Diário a partir dos sistemas de informação corporativos e locais. Em conclusão constatou-se que a grande maioria das informações publicadas no DCD é passível de recuperação em diversos sistemas de informação, o que, no entanto, não garante a qualidade e tempestividade na recuperação.

Untersuchungen zur chemischen Zusammensetzung und Nematodenbelastung von Stinten (Osmerus eperlanus L.)

Smelt (Osmerus eperlanus L.) from the river Elbe has a long tradition as local food speciality. It is offered baked or fried every year during spring in many restaurants along the river. Information about the composition of the edible part and its changes during fishing season are scarce. In earlier days the fish was mostly sold by local fisherman directly after catch. Today the fish is also offered as ungutted fresh fish in ice on the whole sale market. The freshness of this fish has not been studied. Smelt from the river Elbe is known to contain nematode larvae (Pseudoterranova decipiens) in the muscle meat. Actual quantitative data on the abundance and prevalence in the commercially offered ice stored fish are missing.

Limitações à gestão de recursos humanos em saúde no nível municipal

Esta tese de doutorado tem como foco as limitações que se colocam aos gestores do nível local para produzir serviços de qualidade em sistemas de saúde. A definição tradicional do conceito de gestão de recursos humanos foi ampliada por abarcar questões relacionadas à configuração federalista do país, considerando diversidades estruturais e culturais. Utilizou como fonte primária, dados selecionados a partir de entrevistas com gestores de RH com reconhecida experiência na área. Como fonte secundária, utilizou-se as informações pré-selecionadas de pesquisas disponíveis sobre o campo de gestão do trabalho da saúde. A análise do autor confronta as características estruturais do federalismo brasileiro e os desafios decorrentes da base da concepção do sistema nacional de saúde. Os resultados deste estudo iluminam possíveis caminhos alternativos para superar as limitações presentes na gestão de recursos humanos no nível local.

Exploring Indonesian aquaculture futures

Aquaculture is the fastest-growing food production sector globally, with production projected to double within the next 15–20 years. Future growth of aquaculture is essential to providing sustainable supplies of fish in national, regional and global fish food systems; creating jobs; and maintaining fish at affordable levels for resource-poor consumers. To ensure that the anticipated growth of aquaculture remains both economically and ecologically sustainable, we need to better understand the likely patterns of growth, as well as the opportunities and challenges, that these trends present. This knowledge will enable us to better prioritize investments that will help ensure the sustainable development of the sector. In Indonesia, WorldFish and partners have applied a unique methodology to evaluate growth trajectories for aquaculture under various scenarios, as well as the opportunities and challenges these represent. Indonesia is currently the fourth largest aquaculture producer globally, and the sector needs to grow to meet future fish demand. The study overlapped economic and environmental models with quantitative and participatory approaches to understand the future of aquaculture in Indonesia. Such analyses, while not definitive, have provided new understanding of the future supply and demand for seafood in Indonesia stretching to 2030. The learning from this research provides a foundation for future interventions in Indonesian fish food systems, as well as a suite of methodologies that can be applied more widely for insightful analyses of aquaculture growth trajectories in other countries or regions.

青藏高原东部混农季节性放牧及其对高山林线格局的影响

混农季节性放牧（agropastoral transhumance）通过作物种植和畜牧生产相结合的方式对不同海拔高度带上的资源进行相互补充利用，在亚洲兴都库什地区、青藏高原、横断山、东部及南部非洲、南美安第斯地区等具有悠久的历史。这种传统的生计系统几千年以来一直是居住在该地区的人类社会和自然生态系统相互作用的主要形式之一。这种传统的资源利用方式与山地自然植被以及特殊的山地人类文化和社会特征具有密切的协同演变关系。认识和理解这一关系，是山地生态学和人类学的核心科学问题之一。近年来，山地生态系统的多重功能性及动态演变对山区社会经济可持续发展的重要意义受到人们的不断关注。本文通过对云南省德钦县的12个自然村的混农季节性放牧以及对云南德钦、四川壤塘等山地植被格局特别是高海拔地带植被格局的的详细调查，探讨青藏高原东缘地区混农季节性放牧的主要特征、系统构成及相互关系，及其在全球变化、经济全球化和市场化及现代化过程中的变化趋势，分析混农季节性放牧与高山林线格局及生态系统的互动关系，旨在探讨山地地区人类活动与自然生态系统之间的互动关系，从而为山区社会经济可持续发展、环境建设和生物多样性保护等国家战略提供理论依据。 调查结果表明，混农季节性放牧是一种适应青藏高原东部高山峡谷地区环境因子及自然资源呈明显的垂直分布、资源数量稀少而时空分布异质性极高的生存环境的一种传统经济形式。这种传统的畜牧业的主要生产目的仍然是提供当地基本生存所需的产品，饲养牲口的种类和数量取决于农户的当地需求并且受资源的限制，因而维持在比较低的水平的。分布在不同海拔高度的放牧资源在一年中被牲口利用的时间也不同，互为补充，共同构成混农季节性放牧的资源基础。根据各社区永久居住点的位置和该村的土地资源特别是牧草地资源的分布范围，牲口迁移的距离和格局有较大的差异。。天然牧场仍然是最主要的畜牧业生产资源。混农季节性放牧中的农业系统和牧业系统互为补充，共同构成调查地区完整的的生计系统，农耕活动为放牧活动提供精饲料如粮食等和冬季饲料如秸秆， 其数量往往成为家庭畜牧业生产规模的主要决定因子之一。 通过对牲口数量和结构、牲口的时空迁移格局、牧业活动在整个经济活动中的相对重要性以及牧业活动和作物种植的关系方面的研究分析，混农季节性放牧在近几十年发生了深刻的变化。主要表现在牲口数量总体下降，牲口组成发生变化，牲口移动性降低、牧业活动的经济重要性下降以及牧业活动和种植活动之间的相互依存度降低等。上述变化的根本驱动力是发生在当地、地区及全球尺度上的环境、政治、社会经济、技术和文化等的变化，从而造成当地群众畜牧生产目标、土地利用和劳动力的分布等发生了变化。当地生计系统发生的改变可能会带来对方面而深刻的政治、社会经济、文化和生态影响。 混农季节性放牧这种古老的传统生计策略面临着许多挑战，如冬季饲料短缺、草场退化、缺乏市场竞争力、经济重要性降低、对年轻人缺乏吸引力、国家缺乏专门的政策指导等。与此同时，经济全球化、市场经济、新技术的应用、替代生计机会的增加、国家对于山地生态系统的作用的重新定位等也为传统生计系统转型、实现社会与生态共赢创造了机遇。 混农季节性放牧活动对亚高山及树线交错带生态系统系统的互动方式主要体现在以下几个方面：（1）牲口啃食、践踏等影响森林群落更新，改变森林群落的组成和结构，从而影响森林群落的演替进程和植被格局。林线边缘是搭建夏棚的首选地点，因此林线及树线交错地带就成了牲口活动的主要场所之一；（2）利用火烧开辟、维持和改良高山牧场； 3）在亚高山火灾迹地的放牧活动能够阻止火烧迹地的顺向演替； 4）牧民在林线附近获取建材和薪材等活动影响高山林线附近森林的结构和功能。 在调查区域，梅里雪山、白马雪山、甲午雪山的林线海拔高度在4200-4300m之间； 四川雅江、理塘一线，林线位置多在4300-4400m；四川壤塘二林场一带的林线主体在4100-4200m，在个别地区达到4300m； 在贡嘎山的南坡和东坡一带，林线位置在3600-3700m；而在四川松潘一带，林线位置主体在3700-3800米左右。树线高度的分布趋势和林线一致。混农季节性放牧及其有关人类利用活动使研究地区很多地方高山林线降低、树线交错带宽变窄或消失。在研究地区，总体情况是，阳坡和半阳坡（南坡、西南坡等）的林线和树线比阴坡和半阴坡（北坡、东北坡等）低，变化幅度达20-200m。这种差异主要是为了开辟牧场而人为清除了南向坡自然林线及其以上的植被从而使林线位置下降所致。在南坡自然林线保留得比较好的地方，林线和树线依然可以达到甚至超过北坡林线和树线的高度。放牧活动抑制了高山林线带火烧迹地的天然更新，从而使林线位置保持在目前的位置。 放牧活动对高山林线带森林群落更新的影响是显著的。自然林线内的乔木个体密度特别是新生苗和幼苗的密度大大高于非自然林线。没有放牧的自然林线及树线交错带内的I级个体（新生苗）密度达到725-2917株/公顷，而与之相对的处理样地内I级个体的密度只有0-228株/公顷；II级个体（高度10-50cm）也表现出类似的趋势，在没有放牧的自然林线及树线交错带样方内，其密度达到550-5208株/，而在放牧处理样方内只有14-321株/公顷。在非自然林线带样地内，在有正常放牧的样地内，完全缺乏I级个体。 从相对比例来看，没有放牧的样方内的I、II级个体在全部个体中所占的比例显著高于有放牧活动的样方。放牧使林线交错带的乔木幼苗数量显著减少，从而影响林线及树线交错带森林群落的天然更新过程。林线和树线交错带的灌木对乔木幼苗具有重要的保护作用，能够为树线树种如冷杉等幼苗的定居体提供有利的微气候环境，同时保护苗免受牲口的啃食和践踏。火烧以后接着进行放牧能够100%地抑制高山林线带的幼苗更新。 高山牧场放牧强度降低、使用时间缩短而低海拔地带放牧强度增加是研究地区混农季节性放牧系统的一个显著变化。这种变化也必然会引起各海拔带上的生态系统的变化。放牧强度的降低、生产性用火的停止将导致原来通过人工火烧而降低并通过进一步的火烧和放牧活动来维持的林线及其以上地带的灌木盖度和高度的增加，从而为林线森林群落的扩张创造条件。 青藏高原东部高山峡谷地区是我国重要的山地生态系统，在我国的生物多样性保护、生态环境建设、社会经济可持续发展战略中具有举足轻重的作用。正确认识人类特别是当地传统的生计系统与生态环境系统的互动关系是实现上述战略目标的前提。决策者必须以综合、系统的的视角协调促进社会经济可持续发展、保护生物及文化多样性和维持人、牲口和生态系统之间的平衡的多重目标。 Agropastoral transhumance, which makes a complementary exploitation of the natural resources at different altitudinal belts through a combination of migratory animal husbandry and crop cultivation, has a long history in Hindu-Kush Himalaya, Tibet Plateau, Hengduan Ranges, eastern and southern Africa and the Andes region of south America.For millennia, this traditional livelihood strategy has been one of the main forms of interaction between human societies inhabiting in these regions and their natural ecocystems. A close co-evolutionary relationship has been developed between this indigenous resources management systems and the mountain vegetation systems on the one hand and a unique set of cultural values and social features on the other. Understanding this relationship has been one of the core scientific issues in mountain ecology and anthropology. In recent years, the importance of the multiple functions of the mountain ecosystems and their dynamic changes in the sustainable socio-economic development of the mountain regions has gained increasing attention. This paper, which is based on a detailed study on the agropastoral practices of the 12 natural villages in Deqin County of Yunnan, and the mountainnn vegetation patterns in Deqin of Yunnan and Rangtang County of Sichuan, intends to reveal the major characteristics, system composition and the inter-relations of the subsystems of the agropastoral transhumance in Eastern Tibetan Plateau as well as the trends of changes of the system within the context of global changes, economic globalization and modernity process of China and analyze the relations between agropastoral transhumance and alpine ecosystem, ao as to understand the interactions between human activities and natural ecosystems of the mountains and provide theoretical basis for the national strategies in eocioeconomic development, environmental reconstruction and biodiversity conservation in the mountain regions. Results of the survey indicate that agropastoral transhumance in the investigated area is a traditional economic form that is highly adapted to the eastern Tibet Plateau where the topography features high peaks and deep gorges and where the highly variable environmental parameters and scanty natural resources exhibit a distinct vertical spectrum of distribution and great temporal and spatial heterogeneity. The main objective of pastoral management is still aimed at the production of basic goods and services of local people and thus the type and size of animals raised for each household mainly depend on local needs and are limited by the availability of natural resources. The scale of production is relatively low. Pastoral resources at different altidudinal belts are complementarily used at different seasons of a year and thus form the resources basis for agropastoral production of the study area. Migration distances and patterns vary with the location of the permanent settlements, the elevational distribution range of the resources of the villages concerned. Natural pastures (rangelands) are the main fodder resources and sumplement feedings only account for less than 5% of the total fodder consumption. Crop cultivation and pastoral activities support each other to form a complete livelihood system. The ability of the farmig lands (crop cultivation) to provide the pastoral activities with concentrates and sumplements often becomes a main factor limiting the scale of livestock production at household level. Agropastoral transhumance is experiencing drastic changes in recent decades as is reflected in the size and composition of animals, the seasonal migration pattern, the relative importance of pastoralism in the household economy and the interplays of agricultural and pastoral elements of the system. In general, there is a decline in animal population and mobility, a shift in animal composition to meet new needs arising from changed macro-economic situation, a decrease in the relative importance in the household economy and an increasing decoupling of agro&pastoral relations. The fundamental divers of these changes can be traced to environmental, social, economic, technological and cultural changes from local to global levels and such changes have further caused local changes in livestock management objectives, land use and distribution of labor forces. Changes in local livelihood systems could have profound political, socioeconomic, cultural and ecological conseuquences. Agropastoral transhumance, as an age-old traditional livelihood strategy, is facing multifacet challenges, such as winter fodder shortage, rangeland degradation, lack of market competitiveness, decrease in economic importance, lack of appreciation among the young generation and adequate policies from the government. At the same time, economic globalization, market economy, intrdoctution of new technologies, increase of alternative income generating opportunities and the national re-oreitation of policies on mountain ecosystems have all brought about new opportunities for the transformation of the traditional livelihood system and the synchronized development of local society and the environment. Agropastoral transhumance interacts with the ecosystems at the timberline and treeline ecotone mainly through the following aspects: 1)Animal browsing and stamping affect the regeneration process of the forest communities and alters the composition and structure of the forest which in turn affect the succession process and vegetation pattern of the forest communities. Forest edges are the priority locations for summer houses and therefore the timeline and treeline area becomes the major venues of aninal activities; （2）herders create, maintain and improve pastures through burning that remove the forest communities at the timeline and treeline ecotone; 3）immediate grazing on the fire sites can significantly prevent the fire sites from perogressive succession; and 4）herders harvesting of construction timber and firewoods affects the structure and functions of the forest communities at the timberline and treeline zone. Timberline position in the survey region shows geographical variations. It is around 4200-4300m in Meilixueshan, Baimaxueshan and Jiawuxueshan in Northwest of Yunnan and rises to 4300-4400m in Yajiang County and Litang County of Sichuan. In Rangtang of Sichuan, it is between 4100-4200m, though reaching 4300m in localized sites. In the southern and eastern slopes of Gongga Mountain, the timberline is only between 3600m and 3700m and in Songpan County at the upper reach of the Minjiang River the timberline is around 3700-3800m.Treeline pattern follows similar trend. In many places, agropastoral transhumance and related human activities have lowered the timberline and treeline and narrowed or removed the treeline ecotone. In the area of survey, generally speaking, timberlines and treelines are lower on the southern slopes than on the northern slopes, with a difference between 20 and 200m. This is mainly because that the use of fires to crerate pastures has removed the forest vegetation at the previous timberline and above. In fact, in many places, well-preserved forests on the south slopes have even high timberline position that the corresponding northern slopes. At subalpine zone, grazing activities could have prohibited the natural regeneration of many forest fire sites and maintained the forest position at the present level. Grazing has a significant impact on the regernation process of forest communities at the timberline zone. Natural timberline and treeline ecotone has much higher density of treeline species individuals especially the emergents and seedlings than the timberlines that are maintained by human activities. In natural timberline and treelien ecotone without grazing interference, the density of the I Class seedlings (less than 10cm in height) ranges 725-2917 /hm2; while that in the treatment plots (with grazing disturbance) is only 0-228//hm2；II Class seedlings (10-50cm）exhibit similar density trends, reaching 550-5208//hm2 in natural timberline without grazing but only 14-321//hm2 in the plots with grazing treatment. In the man-created timberlines, there is no I Class seedling at all in plots with normal grazing activities. In relative terms, in plots without grazing activities, the propotion of I Class and II Class seedlings is much higher than that in plots with grazing. Grazing activities have significantly reduced the number of seedlings in the timberline ane treeline ecotone, and thus affect the natural regeneration process of the forests. Shrubs at the timberline and treeline ecotone can effectively protect the seedlings from severe climate and animal tramping, thus increasing the survival rate of the seedlings. Grazing following fires can completely inhibit forest regeneration process at timberline. Changes in agropastoral transhumance will have great impact on the timberline and treeline pattern of the studied area. The decrease in grazing intensity on alpine pastrues and the cessation of the use of fires will result an increase in the cover and height of shrubs above the present human-maintained treeline, which will create further condition for the expansion of timberline forest communities. Eastern Tibet Plateau harbors some most important mountain ecosystems of China that are of vital importance to the country’s strategy in biodiversity conservation, environmental construction and sustainable sociaoeconomic development. A proper knowledge of the interactions between traditional livelihood systems and the ecosystems in the region is a precondition to the realization of the above strategic goals. Therefore, the decision-makers must have a holistic and systemic perspective so as to integrate the multiple objectives of promoting sustainable socioeconomic development, conserving biological and cultural diversity and maintaining the balances among people, animal population and the ecosystems.

空间对接机构缓冲系统及其运动学建模

以异体同构周边式对接机构差动式缓冲系统为对象 ,将缓冲机构分解成 6个独立分支 ,通过设立局部坐标系 ,建立缓冲系统运动学正、逆解模型。该建模方法可以消除各分支之间的耦合关系 ,使建模得以简化。算例说明这种缓冲系统运动学模型是正确有效的。