scholarly journals Cyclic changes in keratocyte speed and traction stress arise from Ca2+-dependent regulation of cell adhesiveness

2005 ◽  
Vol 118 (2) ◽  
pp. 369-379 ◽  
Author(s):  
A. D. Doyle
Keyword(s):  
Cyclic Changes ◽  
Traction Stress

HISTOMORPHOLOGICAL CHANGES IN THE BRAIN IN RELATION TO OVARIAN CYCLE OF FRESHWATER CRAB, BARYTELPHUSA CUNICULARIS

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
C.A. JAWALE
Keyword(s):  
Staining Intensity ◽  
Neurosecretory Cells ◽  
Ovarian Cycle ◽  
Secretory Product ◽  
Freshwater Crab ◽  
Intensity Index ◽  
Cytoplasmic Material ◽  
Histomorphological Changes ◽  
Cyclic Changes ◽  
The Brain

Ovarian maturation by neurosecretory cells in the brain of freshwater crab, Barytelphusa cunicularis have been examined. The histological scrutiny of the brain of Barytelphusa cunicularis related with three types (A, B and C) of neurosecretory cells, which are classified on the basis of size, shape and tinctorial characters. All these types of cells marked annual cyclic changes of cytoplasmic material in association with ovarian cycle. The activity of these cells has been correlated with the ovarian cycle. They are distinguishable by their size, nature locations, shape, nucleus position, cell measure and the secretory product in the cytoplasm. The result indicates that the neurosecretory A, B and C cells of the brain seen involved in the process of mating ovulation. The neurosecretory materials staining intensity index of these cells is described.

scholarly journals Global Economy Crisis and its Impact on Operational Container Carrier’s Strategy

2018 ◽  
Vol 30 (2) ◽  
pp. 187-194
Author(s):  
Vladimir Jerebić ◽  
Stanislav Pavlin
Keyword(s):  
Problem Solving ◽  
Global Economy ◽  
Management Strategies ◽  
Business Environment ◽  
Market Potential ◽  
Container Shipping ◽  
Freight Rates ◽  
New Business ◽  
Cyclic Changes ◽  
Economic And Financial Crisis

The shipping market is an economic derivative of global production and trade, being precariously subject of their cyclic changes, depressions and expansions. This paper analyses the condition of global container shipping market, caused by long-lasting economic and financial crisis that begun in 2008, but is still much visible within the container industry, particularly through overcapacity and low freight rates. It also deals with major changes of maritime container carrier’s management strategies, development and application of advanced transportation, technological, technical, economical, organizational and commercial measures in order to adapt and cope with new business environment. Finally, an attempt is made to forecast the market, potential difficulties and to propose problem-solving measures.

Transient Response of Polymer Electrolyte Membrane Fuel Cell to Variations in Operating Parameters

2013 ◽  
Author(s):  
A. Verma ◽  
R. Pitchumani
Keyword(s):  
Fuel Cell ◽  
Transient Response ◽  
Single Channel ◽  
Rapid Change ◽  
Transient Behavior ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Operating Parameters ◽  
Complex Species ◽  
Cyclic Changes

Due to rapid change in loads during automotive applications, study of dynamic behavior of proton exchange membrane (PEM) fuel cells is of paramount importance for their successful deployment in mobile applications. Toward understanding the effects of changes in operating parameters on the transient behavior, this paper presents numerical simulations for a single channel PEM fuel cell undergoing cyclic changes in operating parameters. The objective is to elucidate the complex interaction between power response and complex species (water, hydrogen and oxygen) transport dynamics for applied cyclic changes. This study focuses on studying the transient response of fuel cell for specified changes in operating parameters — voltage, pressure and stoichiometry at the cathode and the anode. Numerical studies are carried out on single-channel PEMFC’s to illustrate the response of power as the operating parameters are subjected to specified changes. The operating parameters are further optimized using a one dimensional physics based model with an objective to match the power requirements of a drive cycle over a defined period of time.

scholarly journals Human muscle length-dependent changes in blood flow

2012 ◽  
Vol 112 (4) ◽  
pp. 560-565 ◽  
Author(s):  
John McDaniel ◽  
Stephen J. Ives ◽  
Russell S. Richardson
Keyword(s):  
Blood Flow ◽  
Knee Joint ◽  
Joint Angle ◽  
Muscle Blood Flow ◽  
Muscle Length ◽  
Limb Blood Flow ◽  
Knee Joint Angle ◽  
Femoral Blood Flow ◽  
Femoral Blood ◽  
Cyclic Changes

Although a multitude of factors that influence skeletal muscle blood flow have been extensively investigated, the influence of muscle length on limb blood flow has received little attention. Thus the purpose of this investigation was to determine if cyclic changes in muscle length influence resting blood flow. Nine healthy men (28 ± 4 yr of age) underwent a passive knee extension protocol during which the subjects' knee joint was passively extended and flexed through 100–180° knee joint angle at a rate of 1 cycle per 30 s. Femoral blood flow, cardiac output (CO), heart rate (HR), stroke volume (SV), and mean arterial pressure (MAP) were continuously recorded during the entire protocol. These measurements revealed that slow passive changes in knee joint angle did not have a significant influence on HR, SV, MAP, or CO; however, net femoral blood flow demonstrated a curvilinear increase with knee joint angle ( r2 = 0.98) such that blood flow increased by ∼90% (125 ml/min) across the 80° range of motion. This net change in blood flow was due to a constant antegrade blood flow across knee joint angle and negative relationship between retrograde blood flow and knee joint angle ( r2 = 0.98). Thus, despite the absence of central hemodynamic changes and local metabolic factors, blood flow to the leg was altered by changes in muscle length. Therefore, when designing research protocols, researchers need to be cognizant of the fact that joint angle, and ultimately muscle length, influence limb blood flow.

CYCLIC CHANGES IN THE GONAD OF THE AMERICAN OYSTER, CRASSOSTREA VIRGINICA (GMELIN)

1964 ◽  
Vol 42 (2) ◽  
pp. 305-321 ◽  
Author(s):  
Austina V. Kennedy ◽  
Helen I. Battle
Keyword(s):  
Crassostrea Virginica ◽  
Gonadal Development ◽  
Germinal Epithelium ◽  
Nuclear Area ◽  
Seasonal Growth ◽  
Body Width ◽  
Visceral Mass ◽  
Current Season ◽  
Primary Oocyte ◽  
Cyclic Changes

Cyclic changes in the gonad of Crassostrea virginica (Gmelin), a dioecious, oviparous lamellibranch, are described as they occurred toward the most northerly limit of the range, Malpeque Bay, P.E.I., Canada, during 1961 and 1962. The gonad, composed of right and left gonadal lobes lying immediately beneath the mantle, consists of extensively branched follicles comprising the outer margin of the visceral mass. The follicles open into peripherally located ducts which lead into paired gonoducts terminating in the suprabranchial chamber. During the fall and winter the germinal epithelium is in an indifferent or inactive state. The sex for the current season is distinguishable when proliferation commences in May. Maximum gonadal development occurs in late June or early July as determined by comparison of gonadal width to body width in mid-transverse sections. Primary oocytes are initially distinguishable from oogonia by the presence of a distinct nucleolus, and later by an amphinucleolus consisting of a plasmosome and a karyosome. Seasonal growth of the primary oocyte was followed by a planimetry method using measurements of total area and nuclear area from prepared sections. The spindle for the first meiotic division is established immediately on rupture of the oocyte from the follicular wall. Spermatogenesis and spermiogenesis are completed within the follicle. Following spawning, amoebocytes infiltrate the follicles and interfollicular connective tissue to phagocytize unspawned gametes. By late October the follicles of both male and female consist of a low germinal epithelium and a few unresorbed gametes, and remain inactive until proliferation the following spring.

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