The Effects of Plant Invasion and Ecosystem Restoration on Energy Flow through Salt Marsh Food Webs

2013 ◽  
Vol 37 (2) ◽  
pp. 339-353 ◽  
Author(s):  
Kimberly L. Dibble ◽  
Laura A. Meyerson
Keyword(s):  
Salt Marsh ◽  
Food Webs ◽  
Energy Flow ◽  
Plant Invasion ◽  
Ecosystem Restoration ◽  
Flow Through

Host manipulation by parasites as a cryptic driver of energy flow through food webs

2019 ◽  
Vol 33 ◽  
pp. 69-76
Author(s):  
Takuya Sato ◽  
Ryosuke Iritani ◽  
Midori Sakura
Keyword(s):  
Food Webs ◽  
Energy Flow ◽  
Host Manipulation ◽  
Flow Through

scholarly journals Hip Range of Motion and Strength and Energy Flow During Windmill Softball Pitching

2021 ◽  
Author(s):  
Gretchen D. Oliver ◽  
Kyle Wasserberger ◽  
Anne de Swart ◽  
Kenzie Friesen ◽  
Jessica Downs ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Energy Flow ◽  
Injury Risk ◽  
External Rotation ◽  
Whole Body ◽  
Net Energy ◽  
Acceleration Phase ◽  
Hip Range Of Motion ◽  
Flow Through ◽  
The Relationship

Context Inadequate hip range of motion (ROM) and isometric strength (ISO) may interfere with energy flow through the kinetic chain and result in increased injury susceptibility. Objective To examine the relationship of hip ROM and ISO with energy flow through the trunk and pitching-arm segments during the windmill softball pitch in youth athletes. A subsequent purpose was to examine the relationship between energy flow and pitch speed. Design Descriptive laboratory study. Setting University research laboratory. Patients or Other Participants A sample of 29 youth softball pitchers (age = 11.2 ± 1.3 years, height = 155.0 ± 10.4 cm, mass = 53.2 ± 12.6 kg). Main Outcome Measure(s) Bilateral hip internal-rotation and external-rotation (ER) ROM and ISO were measured. Net energy outflow and peak rates of energy outflow from the distal ends of the trunk, humerus, and forearm were calculated for the acceleration phase of the windmill softball pitch, and pitch speed was measured. Results Regression analysis revealed an effect of drive-hip ER ISO on the net energy flow out of the distal ends of the trunk (P = .045) and humerus (P = .002). Specifically, increased drive-hip ER ISO was associated with increased net energy outflow from the trunk to the humerus and from the humerus to the forearm. No significant effects of hip ROM or other hip ISO measures were observed. Additionally, pitchers who achieved higher peak rates of distal outflow tended to achieve higher pitch speeds. Conclusions An association was present between drive-hip ER ISO and the net energy flow out of the distal ends of the trunk and humerus during the acceleration phase of the windmill softball pitch, emphasizing the importance of hip and lower body strength in executing the whole-body windmill pitch. Overall, energy-flow analysis is an interesting new way to analyze pitching mechanics and will aid in furthering our understanding of performance and injury risk in windmill softball pitching.

Inertia-Driven Controlled Passive Actuation

2015 ◽  
Author(s):  
Douwe Dresscher ◽  
Theo J. A. de Vries ◽  
Stefano Stramigioli
Keyword(s):  
Energy Flow ◽  
Legged Locomotion ◽  
Continuously Variable Transmission ◽  
The State ◽  
Rate Of Change ◽  
Storage Element ◽  
Abstraction Layer ◽  
Variable Transmission ◽  
Alternative Means ◽  
Flow Through

A serious problem with using electrical actuators in legged locomotion is the significant energy loss. For this reason, we propose and analyse an alternative means of actuation: Controlled Passive Actuation. Controlled Passive Actuation aims at reducing the energy flow through electric actuators by actuating with a combination of an energy storage element and a Continuously Variable Transmission. In this work, we present a method where we apply a Continuously Variable Transmission with a storage element in the form of a mass to change the state of another mass (“the load”). An abstraction layer is created to abstract the inertia-driven Controlled Passive Actuation to a source of effort, a force actuator. On this abstracted system, feedback control can be applied to achieve control goals such as path tracking. With simulations and experiments, we show that inertia-driven Controlled Passive Actuation can be used to control the state of an (inertial) load. The experimental results show that the performance of the system is affected by the internal dynamics and limited rate of change of the transmission ratio of the Continuously Variable Transmission.

Effects of Hip Range of Motion and Isometric Strength on Energy Flow during Windmill Softball Pitching

2021 ◽  
Author(s):  
Gretchen D. Oliver ◽  
Kyle Wasserberger ◽  
Anne de Swart ◽  
Kenzie Friesen ◽  
Jessica Downs ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Energy Flow ◽  
External Rotation ◽  
Isometric Strength ◽  
Whole Body ◽  
Net Energy ◽  
Acceleration Phase ◽  
Hip Range Of Motion ◽  
Flow Through ◽  
The Relationship

Abstract Context:Inadequate hip range of motion (ROM) and isometric strength (ISO) may interfere with energy flow through the kinetic chain and result in increased injury susceptibility. Objective:To examine the relationship of hip ROM and ISO with energy flow through the trunk and pitching arm segments during the windmill softball pitch in youth athletes. A subsequent purpose was to examine the relationship between energy flow and pitch speed. Design:Descriptive laboratory study. Setting:University research laboratory. Participants:A sample of 29 youth softball pitchers (11.2±1.3 yrs.; 155.0±10.4 cm; 53.2±12.6 kg). Main Outcome Measure(s):Bilateral hip internal rotation (IR) and external rotation (ER) ROM and ISO were measured. Net energy outflow and peak rates of energy outflow from the distal ends of the trunk, humerus, and forearm were calculated for the acceleration phase of the windmill softball pitch, and pitch speed was measured. Results:Regression analysis revealed a significant effect of drive hip ER ISO on the net energy flow out of the distal ends of the trunk (p=0.045) and humerus (p=0.002). Specifically, increased drive hip ER ISO was associated with increased net energy outflow from the trunk to the humerus and from the humerus to the forearm. No significant effects of hip ROM or other hip ISO measures were observed. Additionally, pitchers who achieved higher peak rates of distal outflow tended to also achieve higher pitch speeds. Conclusions:There is an association between drive hip ER ISO and the net energy flow out of the distal ends of the trunk and humerus during the acceleration phase of the windmill softball pitch, emphasizing the importance of hip and lower body strength in the execution of the whole-body windmill pitch. Overall, energy flow analysis is an interesting new way to analyze pitching mechanics and will aid in further understanding of performance and injury risk in windmill softball pitching.

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