Ariel - Volume 12(13) Number 2

Editor Gary Fishbein Production & Business Manager Rich Davis Layout Editor Lynn Solomon Assistant Layout Editors Bessann Dawson Tonie Kline Becky A. Zuurbier Photography Editor Ben Alma

Parameter interdependence and success of skeletal muscle modelling

In muscle and movement modelling it is almost invariably assumed that force actually exerted is determined by several independent factors. This review considers the fact that length force characteristics are not a relatively fixed property of muscle but should be considered the product of a substantial number of interacting factors. Level of activation and recruitment are influential factors in relation to aspects of muscle architecture. For the level of activation effects of its short term history (potentiation, fatigue in sustained contractions) have to be taken into account and are reviewed on the basis of recent experimental results as well as available literature. History is also an important determinant for the effect of length changes. This concept is introduced on the basis of recent experimental evidence as well as available literature. Regarding effects of muscle architecture, the concepts of primary and secondary distribution of fibre mean sarcomere length are introduced as well as effects of muscle geometry for mono- and bi-articular muscles on those distributions. Implications for motor control are discussed and the need for intramuscular coordination indicated

Sustainability and certification in the biofuels sector: some critical observations

The society at large demand sustainable production of products often defined in terms of the planet, profit and people categories. Many industrial sectors started to internalize sustainability in their company processes. Public policies underscored these initiatives by giving incentives to raise awareness, support initiatives and disseminate the value of sustainability. In the last decade initiatives came to life to connect confidence, trust and sustainability in the agri- fuel- and food industry. One of the more interesting attempts are Round Tables for sustainable production of palm oil, forest exploitation, biofuels, sugar or soybean. However, are the results positive. Some of these initiatives seem more successful than others. The question is why? How can one interpret these initiatives in terms of performance, structure and governance mechanisms? Based on a comparison of several of these initiatives, conclusions are drawn and hypotheses defined. More in particular, the observations focus on network development, weaknesses in the governance structures, ambivalence in the public domain and the resulting societal confusion

Inhaled particle counts on bicycle commute routes of low and high proximity to motorised traffic

Frequent exposure to ultrafine particles (UFP) is associated with detrimental effects on cardiopulmonary function and health. UFP dose and therefore the associated health risk are a factor of exposure frequency, duration, and magnitude of (therefore also proximity to) a UFP emission source. Bicycle commuters using on-road routes during peak traffic times are sharing a microenvironment with high levels of motorised traffic, a major UFP emission source. Inhaled particle counts were measured along popular pre-identified bicycle commute route alterations of low (LOW) and high (HIGH) motorised traffic to the same inner-city destination at peak commute traffic times. During commute, real-time particle number concentration (PNC; mostly in the UFP range) and particle diameter (PD), heart and respiratory rate, geographical location, and meteorological variables were measured. To determine inhaled particle counts, ventilation rate was calculated from heart-rate-ventilation associations, produced from periodic exercise testing. Total mean PNC of LOW (compared to HIGH) was reduced (1.56 x e4 ± 0.38 x e4 versus 3.06 x e4 ± 0.53 x e4 ppcc; p = 0.012). Total estimated ventilation rate did not vary significantly between LOW and HIGH (43 ± 5 versus 46 ± 9 L•min; p = 0.136); however, due to total mean PNC, accumulated inhaled particle counts were 48% lower in LOW, compared to HIGH (7.6 x e8 ± 1.5 x e8 versus 14.6 x e8 ± 1.8 x e8; p = 0.003). For bicycle commuting at peak morning commute times, inhaled particle counts and therefore cardiopulmonary health risk may be substantially reduced by decreasing exposure to motorised traffic, which should be considered by both bicycle commuters and urban planners

Factors determining a successful socioeconomic introduction of horticulture in foreign countries - Academic Consultancy Training Report

Course: Academic Consultancy Training (YMC 60809) Project: Sustainable development of greenhouse horticulture in developing countries (756) Commissioner: Wageningen UR Greenhouse Horticulture Contact person: Ir. C.J.M. van der Lans Coach: Dr. Ir. J.W. Hofstee Expert: Prof. Dr. O. van Kooten A lot of capital is attracted in the initiation of Dutch horticulture businesses abroad. There is however a lack of knowledge about what is known about the critical factors determining success or failure of a horticultural initiative in a foreign country. The goal of this project is to achieve socio-economic sustainability of the greenhouse horticulture in foreign countries. Therefore a model is presented which contains all the necessary factors that an entrepreneur should keep in mind to achieve socio-economic sustainability. In order to get an overview of all the important factors literature was studied and interviews were conducted. This led to a detailed description of all the issues that should be considered when setting-up businesses abroad. Those factors are represented in a ‘dial’ model pointing out what issues an entrepreneur should consider. The model is subdivided in three topics: market, production and trade & logistics. Important factors related to the market are whether there is a market and how to influence the whole production chain. Important factors for the production are the physical place and the employees. A very important factor of the trading is the legalization and the bureaucracy of the country you are producing in

Plasma from Volunteers Breathing Helium Reduces Hypoxia-Induced Cell Damage in Human Endothelial Cells-Mechanisms of Remote Protection Against Hypoxia by Helium.

PurposeRemote ischemic preconditioning protects peripheral organs against prolonged ischemia/reperfusion injury via circulating protective factors. Preconditioning with helium protected healthy volunteers against postischemic endothelial dysfunction. We investigated whether plasma from helium-treated volunteers can protect human umbilical vein endothelial cells (HUVECs) against hypoxia in vitro through release of circulating of factors.MethodsHealthy male volunteers inhaled heliox (79% helium, 21% oxygen) or air for 30 min. Plasma was collected at baseline, directly after inhalation, 6 h and 24 h after start of the experiment. HUVECs were incubated with either 5% or 10% of the plasma for 1 or 2 h and subjected to enzymatically induced hypoxia. Cell damage was measured by LDH content. Furthermore, caveolin 1 (Cav-1), hypoxia-inducible factor (HIF1α), extracellular signal-regulated kinase (ERK)1/2, signal transducer and activator of transcription (STAT3) and endothelial nitric oxide synthase (eNOS) were determined.ResultsPrehypoxic exposure to 10% plasma obtained 6 h after helium inhalation decreased hypoxia-induced cell damage in HUVEC. Cav-1 knockdown in HUVEC abolished this effect.ConclusionsPlasma of healthy volunteers breathing helium protects HUVEC against hypoxic cell damage, possibly involving circulating Cav-1

DETERMINANTS OF COMPETITIVENESS IN THE SOUTH AFRICAN AGRO-FOOD AND FIBRE COMPLEX

The competitiveness of the South African agro-food and fibre complex depends on a number of factors: technological, socio-political and economic. This paper attempts to identify and analyse such factors by using a framework of analysis proposed by Michael Porter (1990). Appropriate measures to increase competitiveness are proposed. These include improved supply chain management, cost reduction, contractual pricing and the establishment of a clear "agribusiness development policy".Agribusiness, Industrial Organization,

Towards a Design Methodology for Decision Support Systems

The authors propose the use of process models for DSS design. The kind of process models suggested are task structures and decision structures with simple graphical syntax and semantics. The process models form the basis for a coherent DSS design methodology, based upon the bounded rationality paradigm. The history of DSS and DSS design is discussed to form a theoretical position. The resulting methodology has been tested and evaluated in a laboratory experiment. The results of this evaluation will be used for continuous improvement of the methodolog

COMPETING AT THE "CUTTING EDGE": OPPORTUNITIES FOR AGRIBUSINESS PARTNERSHIPS AND CO-OPERATION IN THE SOUTHERN AFRICAN REGION

What are the opportunities for agricultural business, trade and co-operation in Southern Africa and, in particular, South Africa and Zimbabwe - two of the most significant economies in the SADC region? The competitiveness status of agribusiness - from a global viewpoint - in sixteen food and fibre supply chains in Zimbabwe and South Africa is determined in this study using the Revealed Comparative Advantage method of Balassa. Based on this status, there is potential in certain agro-food chains for supply chain integration and cooperation between agribusinesses in South Africa and Zimbabwe. Such partnerships will improve competitiveness and will allow agribusinesses to compete at the "cutting edge" in the global environment.Agribusiness,

CREATING A CHAIN REACTION: THE COMPETITIVENESS OF THE AGRICULTURAL INPUT INDUSTRY IN SOUTH AFRICA

The South African agricultural industry is consistently challenged to increase its competitiveness. The agribusiness supply chain starts with the input sector. The objective of this paper is therefore to determine the competitiveness of the various agricultural input industries in South Africa by using Balassa's method of Revealed Comparative Trade Advantage. This status will then be related to performance of the agricultural industry as a whole. South African manufacturing of farming requisites as a whole are relative marginally competitive in the international arena. However, positive trends in competitiveness is observed. The agricultural machinery industries is not competitive but is improving. The fertilizer industries is becoming increasingly more competitive while in the pesticides industries there is a decrease in the ability to compete internationally. From 1995 there is a relatively high and positive correlation between the competitiveness of the input industry and the agro-food industry in South Africa. This relationship substantiated the claim that fundamentally the South African agricultural economy is more competitive today then a decade ago.Agribusiness,