Effect of Force Sense to Active Joint Position Sense and Relationships between Active Joint Position Sense,Force Sense,Jumping and Muscle Strength

Abstract

We aimed to investigate the effect of external load on the joint position sense (JPS) accuracy and its relation to the target jump height. The present study also aimed to explore the relationship between force sense (FS) and maximum voluntary isometric contraction (MVIC). Participants’ MVIC levels were determined during the 45-degree knee extension task. Then, participants were asked to execute a knee JPS task with external load (EL-JPS) and with no-load (EL-JPS). To assess jumping accuracy participants were instructed to jump with their 50% of maximum jump height. Results indicated that EL-JPS error values were lower than NL-JPS. EL-JPS was correlated to jumping errors. However, the relationship between NL-JPS and jumping errors was not significant. A significant correlation was found between MVIC and FS errors.     

Religion,Violence, and Human Rights

Beginning with the support given by religious groups to humanitarian intervention for the protection of basic human rights in the debates of the 1990s, this essay examines the use of the human rights idea in relation to international law on armed conflict, the “Responsibility To Protect” doctrine, and the development of the idea of sovereignty associated with the “Westphalian system” of international order, identifying a dilemma: that the idea of human rights undergirds both the principle of non‐intervention in the internal affairs of states and the idea of an international responsibility for humanitarian intervention in cases of oppression. The pre‐Westphalian conception of sovereignty as moral responsibility for the common good is then examined as an alternative that avoids this dilemma, and the essay concludes by suggesting that religious ethics also has other resources that, if used, may shed useful light on resolving this problem.     

Response Form, Force, And Number: Effects On Concurrent-schedule Performance

Six hens responded on concurrent variable-interval (key-peck) variable-interval (door-push) schedules of reinforcement in which the second-order (fixed-ratio) requirements on the alternatives (Experiment 1) or the required door forces (Experiment 2) were varied. The key-peck and door-push response (measured as fixed-ratio completion) and time data were well described by the generalized matching law. However, the manipulations of fixed-ratio requirement and required response force differed in their effects. The manipulations of fixed-ratio size affected the response and time measures differently, producing fairly constant, multiplicative biases only in terms of response allocation. It was argued that variations in fixed-ratio size necessarily change the time allocated to that response unit, and thus changes in time bias were not necessarily a fundamental effect of changing the ratio. In contrast, the changes in response bias were a fundamental result of changes in ratio size. The response-force manipulations produced similar bias shifts in terms of response and time allocation, but they appeared to combine with relative reinforcement rate to affect choice interactively. Specifically, behavior appeared to be biased towards the least effortful (i.e., key-peck) response, but the increases in door force had a larger effect on bias when the hens were making this response infrequently (on a lean schedule). The different effects of the fixed-ratio and response-force manipulations on concurrent performance were partially accounted for by the differing times required to complete each response unit under those manipulations, but this would not account for the interaction. The interaction would be consonant with increased response effort decreasing the effective value of the associated reinforcement schedule.     

Optimal kicking of a trampolinist

This work aims to create a mathematical model by using kinematical equations that can describe the landing-jump of a trampoline performance. In this model, the trampolinist was assumed to be a combination of two parts of masses. The landing process (from the time trampolinist touches the net to the deepest location) was discretized into two stages. During these two stages, the trampolinist exerts different internal forces. Analyzing the kinematics of the abovementioned two stages, we obtained the numerical solutions for the optimum loading time and loading force of the trampolinist to get the deepest landing location. This work has potential for guiding a trampolinist in developing his/her personalized optimal strategy for exerting force during landing on the trampoline.     

A job demands-resources perspective on salespersons’ market intelligence activities in new product development

Research shows that R&D's use of sales’ market intelligence positively influences innovation performance. However, little is known about whether this effect hinges on salespersons’ engagement towards and perceptions of market intelligence activities (MIA). Moreover, research remains incomplete regarding the drivers of salespersons’ MIA engagement. Using dyadic data from 359 salespersons and 239 R&D managers in a multi-level model based on the job demands-resources theory, we demonstrate that the positive effect of R&D's use of sales’ market intelligence on innovation performance is especially pronounced when salespersons’ market intelligence generation is high and role ambiguity is low. We also show that although salespersons’ self-set MIA goals are a strong driver of their MIA engagement, not assigning salespersons MIA goals may be a double-edged sword: in the short run, salespersons might engage in MIA voluntarily. However, in the long run, they could incur psychological costs in terms of role ambiguity and conflict, preventing them from engaging in MIA.     

The Influence of Contraction Types on the Relationship Between the Intended Force and the Actual Force

Abstract

It has been demonstrated that the intended force (subjective estimation of force) does not always match to actual force without external feedback. The purpose of this study was to compare the influence of ballistic and tonic contractions on the relationship between the intended and actual force. Subjects produced isometric force at requested percentages of their MVC (20, 40, 60 and 80%) based on subjective estimation of force under two conditions (tonic and ballistic conditions). The tonic condition was to maintain force production, whereas the ballistic condition was to produce force as fast as possible. As a result, the actual force amplitude, the coefficient of variance and EMG amplitude were larger under the ballistic contraction compared with the tonic condition, even the same intended force levels. These results suggest that different motor unit activity and control systems in the ballistic and tonic contractions could alter the relationship between the intended force and the actual force.     

Distinguishing between haloperidol's and decamethonium's disruptive effects on operant behavior in rats: use of measurements that complement response rate.

The behavioral effects of haloperidol (0.04 to 0.16 mg/kg) and nonparalytic doses of decamethonium (0.2 to 0.8 mg/kg) were studied with operant methods that permitted the measurement of response rate, peak force of response, duration of response, and duration of the rat's head entry into the reinforcement dipper well. Type of operant response topography (forelimb press or forelimb grasp-and-pull) and peak force (low or high) required for reinforcement delivery were independent variables. The low-force, press-topography condition yielded qualitatively different profiles for the two drugs. Haloperidol increased peak force and duration of operant response, increased maximum head entry duration, and temporally dissociated forelimb and head entry behavior. Decamethonium decreased force and duration of operant response, did not appreciably affect maximum head entry duration, and did not influence the normal temporal coupling of forelimb and head entry responses. The haloperidol effects were seen as reflections of pseudo-Parkinsonism, not muscle weakness, which appeared to be the primary source of decamethonium's behavioral effects.     

Connect within to connect outside: effect of salespeople's political skill on relationship performance

Scholars have recently explored the effects of salespeople's intraorganizational relationships on salespeople's job-related outcomes. Grounded in social influence theory, we explore the effects of salespeople's intraorganizational skills on salesperson relationship performance. We empirically tested the proposed relationships using the data from a non-Western sales force working with an organization in an emerging economy. The results indicate that salespeople's political skill positively contributes to salespeople's identification with the organization and to creative performance, while strikingly, we also find that salesperson task adaptivity weakens these effects. Moreover, salespeople's identification and creative performance are positively related to customer satisfaction. These findings demonstrate that salespeople's intraorganizational relationships play a key role in enhancing customer satisfaction. In light of these results, we explore implications for marketers and academics and conclude by suggesting directions for further research.     

Pushing moral buttons: The interaction between personal force and intention in moral judgment

In some cases people judge it morally acceptable to sacrifice one person’s life in order to save several other lives, while in other similar cases they make the opposite judgment. Researchers have identified two general factors that may explain this phenomenon at the stimulus level: (1) the agent’s intention (i.e. whether the harmful event is intended as a means or merely foreseen as a side-effect) and (2) whether the agent harms the victim in a manner that is relatively “direct” or “personal”. Here we integrate these two classes of findings. Two experiments examine a novel personalness/directness factor that we call personal force, present when the force that directly impacts the victim is generated by the agent’s muscles (e.g., in pushing). Experiments 1a and b demonstrate the influence of personal force on moral judgment, distinguishing it from physical contact and spatial proximity. Experiments 2a and b demonstrate an interaction between personal force and intention, whereby the effect of personal force depends entirely on intention. These studies also introduce a method for controlling for people’s real-world expectations in decisions involving potentially unrealistic hypothetical dilemmas.     

Force Increase in a Repetitive Motor Task Inducing Motor Fatigue

To evaluate task induced motor fatigue in a well-established finger tapping task, we analyzed tapping parameters and included the time course of measures of force. We hypothesized that a decline in tapping force would reflect task induced motor fatigue, defined by a lengthening of inter-tap intervals (ITI). A secondary aim was to investigate the reliability of tapping data acquisition with the force sensor. Results show that, as expected, tapping speed decreased linearly over time, due to both an increase of ITI and tap duration. In contrast, tapping force increased non-linearly over time and was uncorrelated to changes in tapping speed. Force data could serve as a measure to characterize task induced motor fatigue. Force sensors can assess a decline in tapping speed as well as an independent increase of tapping force. We argue that the increase of force reflects central compensation, i.e. perception of fatigue, due to an increase in task effort and difficulty.