Long term measurements of neutron dose rates at Testa Grigia high altitude research station (3480 m. a.s.l.)

2022 ◽  
pp. 109972
Author(s):  
S. Vernetto ◽  
M. Laurenza ◽  
M. Storini ◽  
A. Zanini ◽  
P. Diego ◽  
...  
Keyword(s):  
High Altitude ◽  
Neutron Dose ◽  
Research Station ◽  
Dose Rates

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Changes in alveolar and arterial gas tensions as related to altitude and age

1964 ◽  
Vol 19 (1) ◽  
pp. 21-24 ◽  
Author(s):  
James W. Terman ◽  
Jerry L. Newton
Keyword(s):  
High Altitude ◽  
Pulmonary Ventilation ◽  
Research Station ◽  
Age Changes ◽  
Altitude Acclimatization ◽  
Ventilation Perfusion Ratio ◽  
Early Phases ◽  
Chilean Andes

In the summer of 1962 at the White Mountain Research Station the early phases of altitude acclimatization were studied in six of the surviving eight members of the 1935 expedition to the Chilean Andes; they were from 58 to 71 years of age. Alveolar and arterial Po2 and Pco2 were determined for each man a few hours after arrival at 3,093 m and at 3,800 and 4,343 m over the next few days. The effects of age were superimposed on the classical responses to high altitude. The arterial and alveolar Pco2 values showed no significant gradient; the alveolar Pco2 was found to be lower for a given altitude than 27 years before. For example, their average alveolar Pco2 at 4,700 m in 1935 was 27.7 mm Hg as opposed to 25.1 mm Hg at 4,343 m in 1962. The case of Hall was exceptional: his alveolar Pco2 ranged from 21 to 24 mm Hg regardless of altitude for his sojourn of 22 days. In 1935 these six men had a mean A-a Po2 gradient of +3.0 mm Hg at 4,700 m, while in 1962 the gradient over the three altitudes was +12.4 mm Hg. These findings would likely be explained partially by age changes in the pulmonary ventilation-perfusion ratio. acclimatization; pulmonary ventilation-perfusion ratio; alveolar-arterial Po2 and Pco2 gradients; alveolar hyperventilation; aging and altitude Submitted on February 19, 1963

scholarly journals Simultaneous generalized and low-layer SCIDAR turbulence profiles at san pedro mártir observatory

2019 ◽  
Vol 490 (1) ◽  
pp. 1397-1405 ◽  
Author(s):  
R Avila ◽  
O Valdés-Hernández ◽  
L J Sánchez ◽  
I Cruz-González ◽  
J L Avilés ◽  
...  
Keyword(s):  
High Altitude ◽  
Wind Direction ◽  
Close Agreement ◽  
Baja California ◽  
Ground Level ◽  
Combined Effect ◽  
Moderate Altitude ◽  
San Pedro ◽  
Simultaneous Measurements

ABSTRACT We present optical turbulence profiles obtained with a Generalized SCIDAR (G-SCIDAR) and a low-layer SCIDAR (LOLAS) at the Observatorio Astronómico Nacional in San Pedro Mártir (OAN-SPM), Baja California, Mexico, during three observing campaigns in 2013, 2014, and 2015. The G-SCIDAR delivers profiles with moderate altitude-resolution (a few hundred metres) along the entire turbulent section of the atmosphere, while the LOLAS gives high altitude resolution (on the order of tens of metres) but only within the first few hundred metres. Simultaneous measurements were obtained on 2014 and allowed us to characterize in detail the combined effect of the local orography and wind direction on the turbulence distribution close to the ground. At the beginning of several nights, the LOLAS profiles show that turbulence peaks between 25 and 50 m above the ground, not at ground level as was expected. The G-SCIDAR profiles exhibit a peak within the first kilometre. In 55 per cent and 36 per cent of the nights stable layers are detected between 10 and 15 km and at 3 km, respectively. This distribution is consistent with the results obtained with a G-SCIDAR in 1997 and 2000 observing campaigns. Statistics computed with the 7891 profiles that have been measured at the OAN-SPM with a G-SCIDAR in 1997, 2000, 2014, and 2015 campaigns are presented. The seeing values calculated with each of those profiles have a median of 0.79, first and third quartiles of 0.51 and 1.08 arcsec, which are in close agreement with other long term seeing monitoring performed at the OAN-SPM.

Long-term observation of underwater ambient noise at the Ieodo Ocean Research Station in Korea

2015 ◽  
Author(s):  
Byoung-Nam Kim ◽  
Seom-Kyu Jung ◽  
Bok Kyung Choi ◽  
Bong-Chae Km ◽  
JaeSeol Shim
Keyword(s):  
Ambient Noise ◽  
Research Station ◽  
Long Term Observation

scholarly journals Differential expression of NPM, GSTA3, and GNMT in mouse liver following long-term in vivo irradiation by means of uranium tailings

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Lan Yi ◽  
Hongxiang Mu ◽  
Nan Hu ◽  
Jing Sun ◽  
Jie Yin ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Radiation Exposure ◽  
Central Vein ◽  
Glutathione S Transferase ◽  
Γ Radiation ◽  
Dose Rates ◽  
Living Organisms ◽  
Uranium Tailings

Uranium tailings (UT) are formed as a byproduct of uranium mining and are of potential risk to living organisms. In the present study, we sought to identify potential biomarkers associated with chronic exposure to low dose rate γ radiation originating from UT. We exposed C57BL/6J mice to 30, 100, or 250 μGy/h of gamma radiation originating from UT samples. Nine animals were included in each treatment group. We observed that the liver central vein was significantly enlarged in mice exposed to dose rates of 100 and 250 μGy/h, when compared with nonirradiated controls. Using proteomic techniques, we identified 18 proteins that were differentially expressed (by a factor of at least 2.5-fold) in exposed animals, when compared with controls. We chose glycine N-methyltransferase (GNMT), glutathione S-transferase A3 (GSTA3), and nucleophosmin (NPM) for further investigations. Our data showed that GNMT (at 100 and 250 μGy/h) and NPM (at 250 μGy/h) were up-regulated, and GSTA3 was down-regulated in all of the irradiated groups, indicating that their expression is modulated by chronic gamma radiation exposure. GNMT, GSTA3, and NPM may therefore prove useful as biomarkers of gamma radiation exposure associated with UT. The mechanisms underlying those changes need to be further studied.

scholarly journals Monitoring growth of Uttis (Alnus nepalensis) at a plantation cite at Dhankuta, Nepal

1970 ◽  
Vol 15 (2) ◽  
pp. 19-23
Author(s):  
T. P. Barakoti
Keyword(s):  
Agricultural Research ◽  
Growth Monitoring ◽  
Research Station ◽  
Growth Modelling ◽  
Annual Increment ◽  
Permanent Sample Plots ◽  
Alnus Nepalensis ◽  
Breast Height ◽  
Growing Environment

A long-term growth monitoring experiment on Uttis (Alnus nepalensis) was conducted in the permanent sample plots of the Agricultural Research Station (ARS) Pakhribas, Dhankuta for 10 years (1992-2001). The average annual increment was diameter at breast height 2.14 cm in 8th year, and was 0.13 cm at 16th year of planting. The trees grew 44 cm to 130 cm per year irrespective of the age. The highest growth rate correspondend with higher rainfall during summer (March-April). Estimated biomass of stem and branches increased by 2-2.5 times within the 10 years period. Thinning and felling every year indicated need for timely management of the plantation to provide better growing environment. The data would be useful for growth modelling and proper management of Uttis plantation in Nepal . Key words: Nepalese alder vs Uttis, height, diameter, biomass, Pakhribas. Banko Janakari Vol.15(2) 2005 pp19-23

scholarly journals Field Research and Conservation

2013 ◽  
Vol 36 ◽  
pp. 179-180
Author(s):  
Chuck Collis ◽  
Jennifer Adams
Keyword(s):  
Behavioral Ecology ◽  
National Park ◽  
Biological Process ◽  
Field Research ◽  
Research Station ◽  
Surrounding Area ◽  
Research Experiences ◽  
Political Processes ◽  
Term Field

The Field Research & Conservation class emphasizes long-term field research experiences, examines ecosystem processes, and investigates the evolution of American perspectives about nature. Our time spent at the UW-NPS research station was divided between pursuing behavioral ecology research and exploring Grand Teton National Park and the surrounding area to gain understanding of how the region was shaped, both by geological and biological process as well as political processes that have been shaped by America’s ever-changing conservation ethic.

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