Assessment of temporal and spatial distribution patterns of aerosol produced by air-puff non-contact tonometer

2021 ◽  
pp. 112067212110547
Author(s):  
Xuhao Chen ◽  
Bingzhen Li ◽  
Chun Zhang
Keyword(s):  
Final Analysis ◽  
Distribution Patterns ◽  
Lateral Side ◽  
Time Intervals ◽  
Temporal And Spatial Distribution ◽  
Air Jet ◽  
Peking University ◽  
Iop Measurement ◽  
Temporal And Spatial ◽  
Single Center Observational Study

Purpose To assess the distribution pattern of aerosol in the aspect of time and direction during the intraocular pressure (IOP) measurement by air-puff non-contact tonometer (NCT) and further offer references for protection from coronavirus disease-19 (COVID-19) in the routine ophthalmic examination. Method A single-center observational study was conducted in the ophthalmology clinics of Peking University Third Hospital. Two air quality detectors were equipped to assess the generated particulate matter (PM) concentration simultaneously within 30 s after IOP measurement in the outpatient hall. Detector A was fixed next to the NCT as a reference, while Detector B was fixed 1 meter away. The participants were divided into two groups depending on the position of Detector B. The generation of aerosol was compared within different groups and time intervals. Results 144 participants were enrolled in the final analysis. At a 1 m distance from the NCT, the PM2.5 concentration significantly increased at the 30 s ( Z = 2.898, Bonferroni-corrected P = 0.038) while the PM10 concentration increased immediately after the IOP measurement ( Z = 2.967, Bonferroni-corrected P = 0.030). The PM2.5 and PM10 concentrations at 1 m were significantly higher immediately ( Z = −2.183, P = 0.029; Z = −2.502, P = 0.012) and 30 s ( Z = −2.021, P = 0.043; Z = −2.071, P = 0.038) after the IOP measurements when the Detector B was vertical to the air jet on the lateral side. Conclusions NCT may produce aerosol after the IOP measurement by air-puff. The generated PM2.5 had a prolonged existence compared with PM10 at a 1 m distance. The lateral side of the air-puff direction may be of higher exposure risk to aerosol.

scholarly journals Conservation implications of the temporal and spatial distribution of Bearded Vulture Gypaetus barbatus in Crete

2002 ◽  
Vol 12 (3) ◽  
pp. 269-280 ◽  
Author(s):  
Stavros Xirouchakis ◽  
Manolis Nikolakakis
Keyword(s):  
Distribution Patterns ◽  
High Mountains ◽  
Temporal And Spatial Distribution ◽  
Gypaetus Barbatus ◽  
Conservation Implications ◽  
Bearded Vulture ◽  
Nesting Sites ◽  
Domestic Livestock ◽  
The Mean ◽  
Temporal And Spatial

We carried out a four-year (1995-1999) survey on the foraging and breeding distribution of Bearded Vulture Gypaetus barbatus on the island of Crete. The age classes of all birds sighted were systematically recorded and data on seasonal distribution patterns were collected; 262 observations were made covering an area of about 4,000 km2, at altitudes ranging from 200 m to 2,450 m a.s.l (mean 1,100 m). Adult birds were distributed evenly throughout the island while young birds avoided active territories and were mostly sighted at the periphery of the high mountains. The species depended almost entirely on domestic livestock herded into and away from the mountains seasonally, with birds foraging in the uplands (> 1,200 m a.s.l.) from early May to late October and frequenting midland pastures (600-1,200 m a.s.l.) for the rest of the year. The mean altitude of nesting sites was 750 m (range = 280-1,450 m), with 80% of nests positioned below the 1,000 m contour. Bearded Vultures are more vulnerable to human-induced mortality within their breeding territories and on midland pastures in winter than in the upland areas in summer.

CLASSIC MAYA WARFARE AND WEAPONS: Spear, dart, and arrow points of Aguateca and Copan

2005 ◽  
Vol 16 (2) ◽  
pp. 291-304 ◽  
Author(s):  
Kazuo Aoyama
Keyword(s):  
Distribution Patterns ◽  
Classic Maya ◽  
Late Classic ◽  
Temporal And Spatial Distribution ◽  
Maya Civilization ◽  
Temporal And Spatial ◽  
High Concentrations ◽  
Human Conflict ◽  
Copan Valley

To provide some insights into the nature and role of warfare in the rise, development, and decline of Classic Maya civilization, this article discusses spear, dart, and arrow points used by the Classic Maya elites at the rapidly abandoned fortified city of Aguateca, Guatemala, and their temporal and spatial distribution patterns in and around Copan, Honduras. Both the royal family and elite scribes/artists at Aguateca used spear and dart points for intergroup human conflict as well as for artistic and craft production under enemy threat. An important implication is that the ruler and elite scribes/artists were also warriors. The unusually high concentrations of identifiable weaponry at the Early Classic hilltop center of Cerro de las Mesas as well as the Acropolis and other Late Classic locations in the Copan Valley, along with other lines of evidence, indicate that warfare was critical in the development and downfall of Classic Maya civilization at Copan.

Temporal distribution, localization and metabolism of all-trans-retinol, didehydroretinol and all-trans-retinal during Xenopus development

1994 ◽  
Vol 301 (1) ◽  
pp. 111-119 ◽  
Author(s):  
J Creech Kraft ◽  
T Schuh ◽  
M R Juchau ◽  
D Kimelman
Keyword(s):  
Spatial Distribution ◽  
Retinoic Acid ◽  
Distribution Patterns ◽  
Retinoid Receptor ◽  
Temporal And Spatial Distribution ◽  
Spatial Distribution Patterns ◽  
Xenopus Embryos ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Temporal And Spatial

Recently, the temporal and spatial distribution patterns of the retinoid receptor ligands 9-cis-retinoic acid and all-trans-retinoic acid were described in Xenopus embryos during early development [Creech Kraft, Schuh, Juchau and Kimelman (1994) Proc. Natl. Acad. Sci. U.S.A., in the press]. The present study demonstrates the presence and distribution of their likely precursors, all-trans-retinol, didehydroretinol, didehydroretinal and all-trans-retinal, as well as the occurrence of 4-oxo metabolites, in Xenopus embryos. The temporal and spatial distribution patterns of all-trans-retinol, didehydroretinol and all-trans-retinal did not coincide with that observed for 9-cis-retinoic acid but, in certain regards, were similar to the patterns delineated for all-trans-retinoic acid and all-trans-retinoyl beta-glucuronide. Evidence is presented that 9-cis-retinoic acid can be synthesized from both all-trans-retinoic acid and all-trans-retinol in Xenopus embryos, suggesting that the difference between the distributions of 9-cis-retinoic acid and the other retinoids may be caused by selective synthesis and/or protein binding of the 9-cis isomer.

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