The effect of mild whole-body cold stress on isometric force control during hand grip and key pinch tasks

Prolonged exposure to cold can impair manual performance, which in turn can affect work task performance. We investigated whether mild whole-body cold stress would affect isometric force control during submaximal hand grip and key pinch tasks. Twelve male participants performed isometric hand grip and key pinch tasks at 10% and 30% of maximal voluntary contraction (MVC) for 30 and 10 s respectively, in cold (8 °C) and control (25 °C) conditions. Finger temperature decreased significantly by 18.7 ± 2.1 °C and continuous low-intensity shivering in the upper trunk increased significantly in intensity and duration during cold exposure. Rectal temperature decreased similarly for the 8 °C and 25 °C exposures. Force variability (FCv) was <2% for the hand grip tasks, and <3% for the key pinch tasks. No significant changes in FCv or force accuracy were found between the ambient temperatures. In conclusion, isometric force control during hand grip and key pinch tasks was maintained when participants experienced mild whole-body cold stress compared with when they were thermally comfortable.     

Velocity-dependent muscle strategy during plantarflexion in humans

This work examines the relative contribution of the triceps surae heads and the tibialis anterior (TA) to tension development with reference to voluntary plantarflexion at various velocities and at two articular positions of the knee joint (extended and flexed at 90 °). Subjects were instructed to perform plantarflexion at various submaximal and maximal velocities with no intention of stopping the movement. Voluntary electromyographic (EMG) activity was recorded and the amplitude, duration and integral were analysed. Integrated EMG (IEMG) was normalized with respect to duration. The maximal M wave and the Hoffmann (H) reflex elicited by electrical stimulation of the tibial nerve were recorded in the triceps surae to estimate the effects in gastrocnemii (G) length and motoneuron excitability differences, respectively, in the two knee positions. The results indicate that: (a) although the largest EMG activity was recorded in the extended limb, the greatest maximal velocities were performed in the flexed knee position; (b) with increasing velocity of movement, all triceps surae muscles showed enhanced IEMG activities; (c) at a low velocity of movement the soleus (So1)/G IEMG ratio was larger in the flexed compared to the extended knee; and (d) with increasing velocity, co-activation of agonist and antagonist muscles appeared. It is concluded that the larger maximal velocity of movement observed in the flexed compared to the extended knee was not primarily related to the neural command of the different triceps surae components, but rather to their mechanical properties. Furthermore, co-activation of agonist and antagonist muscles may contribute to the performance of the contractile strategy during rapid movements.     

Non-uniform mechanical activity of quadriceps muscle during fatigue by repeated maximal voluntary contraction in humans

To determine the non-uniform surface mechanical activity of human quadriceps muscle during fatiguing activity, surface mechanomyogram (MMG), or muscle sound, and surface electromyogram (EMG) were recorded from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles of seven subjects during unilateral isometric knee extension exercise. Time- and frequency-domain analyses of MMG and of EMG fatigued by 50 repeated maximal voluntary contractions (MVC) for 3 s, with 3-s relaxation in between, were compared among the muscles. The mean MVC force fell to 49.5 (SEM 2.0)% at the end of the repeated MVC. Integrated EMG decreased in a similar manner in each muscle head, but a marked non-uniformity was found for the decline in integrated MMG (iMMG). The fall in iMMG was most prominent for RF, followed by VM and VL. Moreover, the median frequency of MMG and the relative decrease in that of EMG in RF were significantly greater (P < 0.05) than those recorded for VL and VM. These results would suggest a divergence of mechanical activity within the quadriceps muscle during fatiguing activity by repeated MVC. Accepted: 19 January 1999     

Active and Passive Physician‐Assisted Dying and the Terminal Disease Requirement

The view that voluntary active euthanasia and physician‐assisted suicide should be made available for terminal patients only is typically warranted by reference to the risks that the procedures are seen to involve. Though they would appear to involve similar risks, the commonly endorsed end‐of‐life practices referred to as passive euthanasia are available also for non‐terminal patients. In this article, I assess whether there is good reason to believe that the risks in question would be bigger in the case of voluntary active euthanasia and physician‐assisted suicide than in that of passive euthanasia. I propose that there is not. On that basis, I suggest that limiting access to voluntary active euthanasia and physician‐assisted suicide to terminal patients only is not consistent with accepting the existing practices of passive euthanasia.     

Emerging multilevel environmental governance – A case of public participation in Poland

In recent decades, nature conservation policies have increasingly considered the participation of various actors. However, the effectiveness of such efforts is often questionable, and better methods of engaging stakeholders are still being sought. In this paper, we present an analysis of a consultation program conducted in the final stage of site selection for Natura 2000 in Małopolska, a region located in southern Poland. Based on a desk study and qualitative research, we analysed the modes and degrees of participation, the normative foundations of the consultation program, and the goals and expectations that characterise participants. The results are discussed using Unnestall's and Arnstein's typologies of participation, which show the limited success of the participatory process in representing all relevant stakeholders and enabling their actual influence on final decisions. The importance of implementing the EU directives for emerging multilevel governance in the nature conservation sector in Central and Eastern Europe, including Poland, is highlighted. In the context of Poland, the consultation program analysed appeared to be a novel and innovative step forward towards the development of a meaningful participatory approach in this region of Europe.     

The use of mouse models to unravel genetic architecture of physical activity: a review

The discovery of genetic variants that underlie a complex phenotype is challenging. One possible approach to facilitate this endeavor is to identify quantitative trait loci (QTL) that contribute to the phenotype and consequently unravel the candidate genes within these loci. Each proposed candidate locus contains multiple genes and, therefore, further analysis is required to choose plausible candidate genes. One of such methods is to use comparative genomics in order to narrow down the QTL to a region containing only a few genes. We illustrate this strategy by applying it to genetic findings regarding physical activity (PA) in mice and human. Here, we show that PA is a complex phenotype with a strong biological basis and complex genetic architecture. Furthermore, we provide considerations for the translatability of this phenotype between species. Finally, we review studies which point to candidate genetic regions for PA in humans (genetic association and linkage studies) or use mouse models of PA (QTL studies) and we identify candidate genetic regions that overlap between species. On the basis of a large variety of studies in mice and human, statistical analysis reveals that the number of overlapping regions is not higher than expected on a chance level. We conclude that the discovery of new candidate genes for complex phenotypes, such as PA levels, is hampered by various factors, including genetic background differences, phenotype definition and a wide variety of methodological differences between studies .     

Effect of dilution degree of commercial nectar and provision of fruit on food,energy and nutrient intake in two rainbow lorikeet subspecies

A feeding trial was performed on adult rainbow lorikeets of two subspecies: six green-naped lorikeets (Trichoglossus haematodus haematodus) and six red-breasted lorikeets (T. haematodus mitchellii). Throughout the entire trial, half of the birds from each subspecies had ad libitum access to water-diluted commercial nectar powder and drinking water only, whereas the other half also received ad libitum apple pieces. During three consecutive 14-d periods, the nectar powder was diluted to a different degree: 1:3 (low), 1:5 (high) and 1:4 (medium) (v:v). Diluting nectar to a higher degree resulted in both subspecies in a decrease in voluntary energy intake. Next, nectar intake significantly decreased when apple was available and apple intake significantly increased when fed higher-diluted nectar. In green-naped lorikeets fed nectar and apple, energy intake was similar between dilution degrees of nectar but was lower compared with feeding only low- or medium-diluted nectar. Whereas, in red-breasted lorikeets, provision of apple next to medium- or high-diluted nectar resulted in higher voluntary energy intake compared with feeding solely nectar of any degree. Overall, protein and thiamine intake as well as Ca:P ratio of the ingested ration were lowest when fed highly diluted nectar and apple. Yet, minimal requirements were still covered. Because energy content of fruit can be higher than liquid diets, in this case medium- or high-diluted nectar, ad libitum provision of fruit as a means to lower voluntary energy intake in lorikeets, for instance in case of obesity, needs to be considered with care. Zoo Biol 28:98–106, 2009. © 2009 Wiley-Liss, Inc.     

Participation in a Gendered Environment: The Case of Community Forestry in India

Women are important stakeholders in natural resource policies since rural women in developing countries are responsible for most of the collection of food, fuel, and firewood for commercial and domestic use. When it comes to the management of these natural resources, gender inequality due to societal traditions could limit the ability of women to participate in policy-making, even when they are not formally excluded. This paper analyzes the effect of gender stratification on women's participation by undertaking an empirical study of a participatory environmental policy program in Indian villages. It endeavors to answer the question of how gender stratification affects participatory environmental policy-making. Using the case study of a community forestry program, it finds that women are still marginalized in decision-making, even in participatory environmental policies. Gender stratification continues to impinge upon forms of democratic decision-making in developing societies. Using facilitating policy tools that seek to empower such marginalized groups would be one way of making participation meaningful for all groups in society.