Cutaneous circulation is correlated with Merino wool production

1994 ◽  
Vol 45 (4) ◽  
pp. 757 ◽  
Author(s):  
Edwards JE Hocking ◽  
PI Hynd
Keyword(s):  
Blood Flow ◽  
Laser Doppler Velocimetry ◽  
Vascular Tissue ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Doppler Velocimetry ◽  
Wool Production ◽  
Merino Wool ◽  
Wool Growth ◽  
Cutaneous Circulation

Laser Doppler velocimetry was used to investigate the cutaneous circulation and its relationship to wool growth in Finewool and Strongwool Merinos. Skin blood flow measured with the laser Doppler velocimeter (LDV) was highly correlated with estimates of blood flow obtained using 57Co-labelled microspheres (R2 = 0.85; P < 0.01), although the absolute values estimated by the microsphere technique were significantly higher (P < 0.001). Strongwool Merinos had a greater rate of blood flowing through the skin than Finewool Merinos, and this was associated with both wool production per unit area of skin (R2 = 0.27, P < 0.01) and with the total volume of germinative tissue in the skin (R2 = 0.54; P < 0.04). The relationship between the microvascular anatomy of the skin and blood flow was also examined in four Finewool Merinos and four Strongwool Merinos. Silicone rubber was infused into the deep circumflex iliac artery within the abdominal flank, from which an index of the area of vascular tissue per unit volume of skin was estimated. This index was not related to blood flow, wool growth or follicle density within nor between strains of Merinos. Both the usefulness and limitations of the LDV are discussed, and it was concluded that (a) blood flow has an important role in the level of wool produced both within and between strains of Merinos, and (b) laser Doppler velocimetry is a useful tool for the study of blood flow in the skin of sheep.

Laser Doppler velocimetry: a new technique for the measurement of intestinal mucosal blood flow

1984 ◽  
Vol 30 (4) ◽  
pp. 225-230 ◽  
Author(s):  
Andrew D. Feld ◽  
Joseph D. Fondacaro ◽  
G. Allen Holloway ◽  
Eugene D. Jacobson
Keyword(s):  
Blood Flow ◽  
Laser Doppler Velocimetry ◽  
Mucosal Blood Flow ◽  
Laser Doppler ◽  
New Technique ◽  
Doppler Velocimetry ◽  
A New Technique

Hybrid blood flow probe for simultaneous H2 clearance and laser-Doppler velocimetry

1987 ◽  
Vol 253 (4) ◽  
pp. G573-G581 ◽  
Author(s):  
G. R. DiResta ◽  
J. W. Kiel ◽  
G. L. Riedel ◽  
P. Kaplan ◽  
A. P. Shepherd
Keyword(s):  
Blood Flow ◽  
Laser Doppler Velocimetry ◽  
Regional Blood Flow ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Flow Probe ◽  
Flow Measurements ◽  
Blood Flow Measurements ◽  
Light Guides ◽  
The Relationship

To perform two independent regional blood flow measurements in tissue volumes of similar dimensions, we designed a hybrid blood flow probe capable of measuring regional perfusion by both laser-Doppler velocimetry (LDV) and H2 clearance. The probe consisted of two fiber-optic light guides to conduct light between the surface of tissue of interest and a laser-Doppler blood flowmeter. Also contained within the probe were a platinum 25-microns H2-sensing electrode and a 125-microns H2-generating electrode. The probe can thus be used to measure local perfusion with H2 clearance. The H2 can either be inhaled or can be generated electrochemically at the locus of interest. Evaluation of the probe in the canine gastric mucosa indicated 1) that the relationship between mucosal flow measurements made simultaneously with H2 clearance and LDV was highly significant and linear and 2) that H2 clearance could potentially be used to calibrate the laser-Doppler blood flowmeter in absolute units. The methods of constructing the flow probes are discussed in detail.

Differences in reactive hyperemia between the intestinal mucosa and muscularis

1984 ◽  
Vol 247 (6) ◽  
pp. G617-G622
Author(s):  
A. P. Shepherd ◽  
G. L. Riedel
Keyword(s):  
Blood Flow ◽  
Metabolic Rate ◽  
Laser Doppler Velocimetry ◽  
Reactive Hyperemia ◽  
Arterial Occlusion ◽  
Oxygen Demand ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Total Blood ◽  
Total Blood Flow

In a previous study of regional intestinal blood flow by laser-Doppler velocimetry, we noted that the mucosa displayed reactive hyperemia following arterial occlusion but that the muscularis did not. Therefore, to determine whether this observation is generally valid, we compared responses of the mucosa and muscularis externa to arterial occlusion. We measured total blood flow to isolated loops of canine small bowel with an electromagnetic flow probe on the supply artery; blood flow either in the mucosa or in the muscularis was measured by laser-Doppler velocimetry. Mucosal and total blood flow consistently showed reactive hyperemia in response to a 60-s occlusion, but the muscularis did not. To determine whether metabolic rate influenced reactive hyperemia, we increased enteric oxygen uptake by placing 5% bile and transportable solutes in the lumen; these agents increased oxygen consumption by 36%. After a 60-s occlusion, the durations of both total and mucosal reactive hyperemia were significantly prolonged by increased metabolic rate. Similarly, the payback-to-debt ratios in both total and mucosal blood flows were significantly increased at elevated metabolic rate. These data support the conclusions that reactive hyperemia occurs more frequently and has a greater magnitude in the mucosa compared with the muscularis and both total and mucosal reactive hyperemia are strongly influenced by the preocclusive oxygen demand. These findings therefore constitute further evidence that metabolic factors contribute to reactive hyperemia in the intestinal circulation.

scholarly journals Pengukuran Intensitas Turbulensi Pada Susunan Sebaris Dan Dua Baris Pipa Bersirip Lingkaran Menggunakan Laser Doppler Velocimeter

REAKTOR ◽  
2017 ◽  
Vol 9 (2) ◽  
pp. 34
Author(s):  
N. Sinaga
Keyword(s):  
Laser Doppler Velocimetry ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Doppler Velocimetry

Artikel ini memaparkan hasil pengukuran kecepatan dan intensitas turbulensi di daerah hilir susunan sebaris dan dua baris pipa bersirip, yang dilator belakangi oleh anggapan bahwa, laju perpindahan kalor dan kerugian tekanan sangat dipengaruhi oleh intensitas turbulensi yang terjadi. Pengukuran dilakukan di dalam seksi uji sebuah kanal hidrolik  berukuran 600 mm x 150 mm x 150 mm, dengan menggunakan teknik Laser Doppler Velocimetry. Pipa dan sirip disusun dalam konfigurasi sebaris dan berseling, dengan dia,eter luar silinder dan sirip masing-masing 16 mm dan 33,6 mm. kecepatan aliran masuk seksi uji dijaga konstan sebesar 1,4 m/detik atau setara dengan Re= 26000, berdasarkan kecepatan arus bebas dan diameter pipa. Disimpulkan bahwa harga intensitas turbulensi dipengaruhi oleh cara  penyusunan pipa dan sirip, dimana susunan pipa berseling cenderung membangkitkan turbulensi yang lebih besar dibandingkan dengan susunan pipa segaris. Akan tetapi, didapatkan pula, intensitas turbulensi susunan pipa segaris dapat ditingkatkan dengan menyusun sirip secara berseling.Kata Kunci : intensitas turbulensi, pipa bersirip, susunan segaris, susunan berseling

Blood flow velocity imaging of malignant melanoma by micro multipoint laser Doppler velocimetry

2010 ◽  
Vol 97 (10) ◽  
pp. 103702 ◽  
Author(s):  
H. Ishida ◽  
T. Andoh ◽  
S. Akiguchi ◽  
H. Shirakawa ◽  
D. Kobayashi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Malignant Melanoma ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Laser Doppler Velocimetry ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Velocity Imaging
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