scholarly journals Nonturbulent Liquid‐Bearing Polar Clouds: Observed Frequency of Occurrence and Simulated Sensitivity to Gravity Waves

2020 ◽  
Vol 47 (10) ◽  
Author(s):  
Israel Silber ◽  
Ann M. Fridlind ◽  
Johannes Verlinde ◽  
Lynn M. Russell ◽  
Andrew S. Ackerman
Keyword(s):  
Gravity Waves ◽  
Frequency Of Occurrence ◽  
Polar Clouds

scholarly journals The ionosphere and radio interferometry

1997 ◽  
Vol 40 (4) ◽  
Author(s):  
T. A. Th. Spoelstra
Keyword(s):  
Gravity Waves ◽  
Daily Variation ◽  
Lower Thermosphere ◽  
Time Of Day ◽  
Ionospheric Disturbances ◽  
Frequency Of Occurrence ◽  
Radio Interferometry ◽  
Travelling Ionospheric Disturbances ◽  
Propagation Parameters ◽  
Definition Of

This paper reviews the effects of the ionosphere on radio astronomjcal observations, what we can learn about the ionosphere from radio interferometry, and a procedure to correct for these effects. This study analyzes the results obtained from observations of celestial point soUl.ces with the Westerbork Synthesis Radio Telescope, WSRT, in the Netherlands from the period 1970-1991. The main conc1usions are: 1) A1though seasona1 effects are c1ear, the occurrence and "strength" of ionospheric irregu1arities show no dependence on solar activity. 2) Assuming that the frequency of occurrence of ionospheric disturbances in Spring and Autumn are similar, Ihe "ionospheric" Winter starts on day 348 ± 3 and ali seasons last for three months. 3) Travelling ionospheric disturbances, TIDs, occur most frequently during daytime in Winter periods. 4) The propagation parameters of these travelling ionospheric irregularities and their periods indicate that these belong main1y to the c1ass of medium sca]e TIDs. 5) Radio interferometry is a powerful tool to locate irregularities causing scintillation and to determine their dimensions. 6) The occurrence of non-periodic irregu1arities is, however, not a function of time of day. 7) The daily variation in the amplitude and frequency of occurrence of the TIDs suggest that the generation of gravity waves may be caused by winds and tides in the lower thermosphere/mesosphere. On the basis of the availab1e data, a definition of a "disturbance measure" indicating to what extent the ionosphere is "quiet" is proposed. Procedures to correct for ionospheric effects and an eva1uation of the different methods to obtain information on the ionospheric e1ectron content are reviewed in sections 8 and 9, respectively.

TEM studies of tweed microstructures in annealed amelia albite

1990 ◽  
Vol 48 (4) ◽  
pp. 1064-1065
Author(s):  
Y. J. Kim ◽  
D. M. Henderson
Keyword(s):  
Annealing Time ◽  
The Other ◽  
Frequency Of Occurrence ◽  
Systematic Trend ◽  
Tweed Structure

Natural Amelia albite (Ab99.3An0.1Or0.6) annealed at 1073° and 924°C for various periods up to 140 days has been studied by NMR. TEM studies of the same sample revealed a distinct tweed microstructure in some samples annealed at both 1073°C and 924°C. On the whole, the quasi-regular tweed has a periodicity of 100 - 200 Å in both directions, one nearly normal to b* and the other approximately parallel to b*, which gives rise to two-directional streaking in SADP’s (Fig. 1 and 2). However, there are some differences in the tweed structure developed on annealing at 1073°C and at 924°C in albite.Albite samples annealed at 1073° show a systematic trend in their development of tweed structures: the regularity, periodicity, and frequency of occurrence increase with annealing time during the first 3 days, and then decrease gradually until no tweed microstructures are seen in samples annealed for more than 15 days. The tweed structure proceeds locally to form one-directional twin-like microstructures.

An Investigation of the Assumptions Underlying the Scoring System of the Arizona Articulation Proficiency Scale: Revised

1979 ◽  
Vol 10 (4) ◽  
pp. 241-245
Author(s):  
Richard J. Schissel ◽  
Linda B. James
Keyword(s):  
Scoring System ◽  
Frequency Of Occurrence

This study examines the assumptions underlying the scoring system of the Arizona Articulation Proficiency Scale: Revised. Twenty-one children between the ages of four years two months and six years 11 months were administered the Arizona Articulation Proficiency Scale: Revised and the Screening Deep Test of Articulation. The subjects' performance on the two tests was compared for the phones: [s], [l], [r], [t∫], [θ], [∫], [k], [f], and [t]. Results suggested that 1) the production of most sounds in only two contexts does not necessarily reflect the accuracy of production of those sounds in other contexts, and 2) for the sounds tested, the weightings assigned on the basis of their frequency of occurrence rather than the frequency with which they were misarticulated overestimated the extent of many articulation errors.

Teachers' Stereotypes of Children Who Wear Hearing Aids

1981 ◽  
Vol 12 (3) ◽  
pp. 139-144 ◽  
Author(s):  
Cletus G. Fisher ◽  
Kenneth Brooks
Keyword(s):  
Elementary School ◽  
School Child ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Social Implications ◽  
Elementary School Child ◽  
Classroom Teachers ◽  
Frequency Of Occurrence ◽  
Service Training

Classroom teachers were asked to list the traits they felt were characteristic of the elementary school child who wears a hearing aid. These listings were evaluated according to the desirability of the traits and were studied regarding frequency of occurrence, desirability, and educational, emotional, and social implications. The results of the groupings are discussed in terms of pre-service and in-service training.

Direct coding for frequency of occurrence

1991 ◽  
Author(s):  
Iohn Jonides ◽  
Caren M. Jones
Keyword(s):  
Frequency Of Occurrence

Computerization of the Patient History -Patient Answers Compared with Medical Records

1986 ◽  
Vol 25 (04) ◽  
pp. 222-228 ◽  
Author(s):  
M. J. Quaak ◽  
R. F. Westerman ◽  
J. A. Schouten ◽  
A. Hasman ◽  
J. H. Bemmel
Keyword(s):  
Internal Medicine ◽  
Medical Records ◽  
Patient Record ◽  
Frequency Of Occurrence ◽  
History Taking ◽  
Patient History ◽  
Patient Complaints ◽  
Computerized Patient Record ◽  
Extensive Information ◽  
Experienced Physician

SummaryComputerized medical history taking, in which patients answer questions by using a terminal, is compared with the written medical record for a group of 99 patients in internal medicine. Patient complaints were analysed with respect to their frequency of occurrence for all important tracts, such as the respiratory, the gastro-intestinal and the uro-genital tracts. About 36% of over 3,200 patient answers were identical in the patient record and the written record, but a considerable percentage of complaints (56%), that were present in the patient record, were missing in the written record; the reverse was true for 4.5%. A computerized patient record appears to contain more extensive information about patient complaints, still to be interpreted by the experienced physician.

Utilizing next-generation sequencing to identify prey DNA in western North Atlantic grey seal Halichoerus grypus diet

2020 ◽  
Vol 655 ◽  
pp. 227-240
Author(s):  
KR Flanders ◽  
ZH Olson ◽  
KA Ono
Keyword(s):  
Next Generation Sequencing ◽  
Feeding Habits ◽  
Atlantic Menhaden ◽  
Halichoerus Grypus ◽  
Frequency Of Occurrence ◽  
Grey Seal ◽  
Next Generation ◽  
Significant Difference ◽  
Generation Sequencing ◽  
Seal Diet

Increasing grey seal Halichoerus grypus abundance in coastal New England is leading to social, political, economic, and ecological controversies. Central to these issues is the foraging ecology and diet composition of the seals. We studied grey seal feeding habits through next-generation sequencing of prey DNA using 16S amplicons from seal scat (n = 74) collected from a breeding colony on Monomoy Island in Massachusetts, USA, and report frequency of occurrence and relative read abundance. We also assigned seal sex to scat samples using a revised PCR assay. In contrast to current understanding of grey seal diet from hard parts and fatty acid analysis, we found no significant difference between male and female diet measured by alpha and beta diversity. Overall, we detected 24 prey groups, 18 of which resolved to species. Sand lance Ammodytes spp. were the most frequently consumed prey group, with a frequency of occurrence (FO) of 97.3%, consistent with previous studies, but Atlantic menhaden Brevoortia tyrannus, the second most frequently consumed species (FO = 60.8%), has not previously been documented in US grey seal diet. Our results suggest that a metabarcoding approach to seal food habits can yield important new ecological insights, but that traditional hard parts analysis does not underestimate consumption of Atlantic cod Gadus morhua (FO = 6.7%, Gadidae spp.) and salmon Salmo salar (FO = 0%), 2 particularly valuable species of concern.

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