Spatial and temporal effects in speckle perfusion measurement

2009 ◽  
Author(s):  
O. B. Thompson ◽  
M. K. Andrews
Keyword(s):  
Temporal Effects ◽  
Perfusion Measurement

Spatiotemporal distribution of foraging in a marine predator: behavioural drivers of hotspot formation

2020 ◽  
Vol 635 ◽  
pp. 187-202
Author(s):  
T Brough ◽  
W Rayment ◽  
E Slooten ◽  
S Dawson
Keyword(s):  
Time Of Day ◽  
Spatiotemporal Distribution ◽  
Temporal Effects ◽  
Marine Predator ◽  
Marine Predators ◽  
Additive Mixed Models ◽  
Density Analysis ◽  
The Times ◽  
Passive Acoustic ◽  
Spatial Locations

Many species of marine predators display defined hotspots in their distribution, although the reasons why this happens are not well understood in some species. Understanding whether hotspots are used for certain behaviours provides insights into the importance of these areas for the predators’ ecology and population viability. In this study, we investigated the spatiotemporal distribution of foraging behaviour in Hector’s dolphin Cephalorhynchus hectori, a small, endangered species from New Zealand. Passive acoustic monitoring of foraging ‘buzzes’ was carried out at 4 hotspots and 6 lower-use, ‘reference areas’, chosen randomly based on a previous density analysis of visual sightings. The distribution of buzzes was modelled among spatial locations and on 3 temporal scales (season, time of day, tidal state) with generalised additive mixed models using 82000 h of monitoring data. Foraging rates were significantly influenced by all 3 temporal effects, with substantial variation in the importance and nature of each effect among locations. The complexity of the temporal effects on foraging is likely due to the patchy nature of prey distributions and shows how foraging is highly variable at fine scales. Foraging rates were highest at the hotspots, suggesting that feeding opportunities shape fine-scale distribution in Hector’s dolphin. Foraging can be disrupted by anthropogenic influences. Thus, information from this study can be used to manage threats to this vital behaviour in the locations and at the times where it is most prevalent.

Neurovascular changes after four-layer compression bandaging in people with chronic venous leg ulcers

2007 ◽  
Vol 22 (2) ◽  
pp. 49-55 ◽  
Author(s):  
R Ogrin ◽  
P Darzins ◽  
Z Khalil
Keyword(s):  
Wound Healing ◽  
Wound Repair ◽  
Statistical Significance ◽  
Sensory Nerve ◽  
Compression Therapy ◽  
Clinical Problem ◽  
Leg Ulcers ◽  
Venous Leg Ulcers ◽  
Perfusion Measurement ◽  
Compression Bandaging

Objectives: Venous leg ulcers represent a major clinical problem, with poor rates of healing. Ideal treatment is compression bandaging. The effect of compression on neurovascular tissues involved in wound repair is unclear. This study aims to assess the effect of four-layer compression therapy (40 mmHg) on neurovascular function and wound healing in people with chronic venous leg ulcers – 15 people (55 years or older) with venous leg ulcers for more than six weeks. Methods: Basal microvascular perfusion measurement (MPM), oxygen tension (tc pO2) measured at sensor temperatures of 39°C and 44°C and sensory nerve function using electrical cutaneous perception thresholds (ECPT) at 5, 250 and 2000 Hz (corresponding to C, A δ and A β fibres) were assessed adjacent to the ulcer site, and at a mirror location on the non-ulcerated limb. Testing was undertaken before and after therapy for 5–12 weeks of four-layer compression bandaging. Results: There was significant improvement in tc pO2 at 44°C and ECPT at 2000 Hz ( P<0.05) compared with pre-intervention. Changes in basal MPM, tc pO2 at 39°C and ECPT at 5 and 250 Hz after compression therapy did not reach statistical significance. Conclusion: Four-layer compression bandaging in people with venous leg ulcers improved some components of neurovascularture in people with chronic venous leg ulcers. Whether this improvement has contributed to wound healing in this study requires further investigation.

Temporal effects of paraquat/maneb on microglial activation and dopamine neuronal loss in older rats

2006 ◽  
Vol 98 (3) ◽  
pp. 760-772 ◽  
Author(s):  
Martine Saint-Pierre ◽  
Marie-Eve Tremblay ◽  
Attila Sik ◽  
Robert E. Gross ◽  
Francesca Cicchetti
Keyword(s):  
Microglial Activation ◽  
Neuronal Loss ◽  
Temporal Effects

scholarly journals B-PO05-064 LASER DOPPLER DERIVED PERIPHERAL PERFUSION MEASUREMENT CAN ASSESS HAEMODYNAMIC STATUS IN VENTRICULAR TACHYCARDIA

Heart Rhythm ◽  
2021 ◽  
Vol 18 (8) ◽  
pp. S397-S398
Author(s):  
Alejandra Andrea Miyazawa ◽  
Ahran D. Arnold ◽  
Matthew J. Shun-Shin ◽  
Daniel Keene ◽  
James P. Howard ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Laser Doppler ◽  
Peripheral Perfusion ◽  
Perfusion Measurement

scholarly journals Fiber-Optic Time-Resolved Fluorescence Sensor for in Vitro Serotonin Determination

1993 ◽  
Vol 47 (5) ◽  
pp. 590-597 ◽  
Author(s):  
Stephane Mottin ◽  
Canh Tran-Minh ◽  
Pierre Laporte ◽  
Raymond Cespuglio ◽  
Michel Jouvet
Keyword(s):  
Chemical Sensor ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Excitation Wavelength ◽  
Nitrogen Laser ◽  
Time Resolved ◽  
Temporal Effects ◽  
Starting Point

At pH 7 and with the excitation at wavelengths above 315 nm, previously unreported fluorescence of 5-HT (5-hydroxytryptamine) is observed. Two fluorescence bands were observed for 5-HT; the first emits at around 390 nm with an associated lifetime near 1 ns, and the other (well known) emits at 340 nm with an associated lifetime of 2.7 ns. With both static and time-resolved fluorescences, the spectral and temporal effects of the excitation wavelength were studied between 285 and 340 nm. With these basic spectroscopic properties as a starting point, a fiber-optic chemical sensor (FOCS) was developed in order to measure 5-HT with a single-fiber configuration, nitrogen laser excitation, and fast digitizing techniques. Temporal effects including fluorescence of the optical fiber were studied and compared with measurements both directly in cuvette and through the fiber-optic sensor. Less than thirty seconds are required for each measurement. A detection limit of 5-HT is reached in the range of 5 μM. Our system, with an improved sensitivity, could therefore be a possible and convenient “tool” for in vivo determination of 5-HT.

scholarly journals The Effects of Securities Class Action Litigation on Corporate Liquidity and Investment Policy

2015 ◽  
Vol 50 (1-2) ◽  
pp. 251-275 ◽  
Author(s):  
Matteo Arena ◽  
Brandon Julio
Keyword(s):  
Investment Decisions ◽  
Market Value ◽  
Corporate Investment ◽  
Class Action ◽  
Investment Policy ◽  
Capital Expenditures ◽  
Litigation Risk ◽  
Securities Litigation ◽  
Corporate Liquidity ◽  
Temporal Effects

AbstractThe risk of securities class action litigation alters corporate savings and investment policy. Firms with greater exposure to securities litigation hold significantly more cash in anticipation of future settlements and other related costs. The result is due to firms accumulating cash in anticipation of lawsuits and not a consequence of plaintiffs targeting firms with high cash levels. The market value of cash is lower for firms exposed to litigation risk. Corporate investment decisions are also affected by litigation risk, as firms reduce capital expenditures in response. Our results are robust to endogeneity concerns and possible spurious temporal effects.

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