High Repeatability (high + repeatability)

Distribution by Scientific Domains


Selected Abstracts


Field Cricket Species Differences in the Temporal Patterns of Long-Distance Mate Attraction Signals

ETHOLOGY, Issue 9 2006
Susan M. Bertram
We quantify variation in the temporal components of long-distance mate attraction signals produced by a North American field cricket, Gryllus rubens Scudder. Total signaling time, trilling bout duration, and hourly bout number exhibit high repeatability within individuals. Extensive variation exists across individuals: some males never signal while others signal for several hours each night; of the signalers, average trilling bout duration ranges from <1 min to well over an hour; some males produce only one trilling bout in an evening while others produce three bouts every 2 h. Body size, weight, wing morphology, and condition do not appear to explain the variation. We compare the temporal signaling components of G. rubens with its sister species, G. texensis. Although G. rubens produce slightly more trills per hour with slightly shorter trilling bout durations, the temporal components of these long-distance mate attraction signals are surprisingly similar across species. [source]


Using an airgun array in a land reservoir as the seismic source for seismotectonic studies in northern China: experiments and preliminary results

GEOPHYSICAL PROSPECTING, Issue 4 2008
Yong Chen
ABSTRACT This paper reports the field setup and preliminary results of experiments utilizing an airgun array in a reservoir in north China for a seismotectonic study. Commonly used in offshore petroleum resource exploration, the airgun source was found to be more useful than a traditional explosive source for large-scale and long offset land seismic surveys. The airgun array, formed by four 1,500 in3 airguns (a total of 6,000 in3 in volume) was placed at a depth of 6,9 m into the reservoir to generate the pressure impulse. No direct evidence was found that the airgun source adversely affected the fish in the reservoir. The peak ground acceleration recorded on the top of the reservoir dam 100 m away was 17.8 gal in the horizontal direction; this is much less than the designed earthquake-resistance threshold of 125 gal for this dam. The energy for one shot of this airgun array is about 6.68 MJ, equivalent to firing a 1.7 kg explosive. The seismic waves generated by the airgun source were recorded by receivers of the regional seismic networks and a temporary wide-angle reflection and refraction profile formed by 100 short-period seismometers with the maximum source-receiver offset of 206 km. The seismic wave signature at these long-offset stations is equivalent to that generated by a traditional blast source in a borehole with a 1,000,2,000 kg explosive. Preliminary results showed clear seismic phases from refractions from the multi-layer crustal structures in the north China region. Forward modelling using numerical simulation confirms that the seismic arrivals are indeed from lower crustal interfaces. The airgun source is efficient, economical, environmentally friendly and suitable for being used in urbanized areas. It has many advantages over an explosive source for seismotectonic studies such as the high repeatability that is supreme for stacking to improve signal qualities. The disadvantage is that the source is limited to existing lakes or reservoirs, which may restrict experimental geometry. [source]


Quantification of polyphenols with potential antioxidant properties in wines using reverse phase HPLC

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 12 2008
Neuza Paixão
Abstract A RP-HPLC method with photodiode array detection (DAD) was developed to separate, identify and quantify simultaneously the most representative phenolic compounds present in Madeira and Canary Islands wines. The optimized chromatographic method was carefully validated in terms of linearity, precision, accuracy and sensitivity. A high repeatability and a good stability of phenolics retention times (< 3%) were obtained, as well as relative peak area. Also high recoveries were achieved, over 80.3%. Polyphenols calibration curves showed a good linearity (r2 >0.994) within test ranges. Detection limits ranged between 0.03 and 11.5 ,g/mL for the different polyphenols. A good repeatability was obtained, with intra-day variations less than 7.9%. The described method was successfully applied to quantify several polyphenols in 26 samples of different kinds of wine (red, rosé and white wines) from Madeira and Canary Islands. Gallic acid was by far the most predominant acid. It represents more than 65% of all phenolics, followed by p -coumaric and caffeic acids. The major flavonoid found in Madeira wines was trans -resveratrol. In some wines, (,)-epicatechin was also found in highest amount. Canary wines were shown to be rich in gallic, caffeic and p -coumaric acids and quercetin. [source]


Repeatability of Sleep Apnea Detection in 48-Hour Holter ECG Monitoring

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2010
Barbara Uzna, ska M.D.
Background: There is a significant relationship between obstructive sleep apnea (OSA) and cardiovascular diseases. Reliability of new methods evaluating apnea in Holter ECG monitoring is still the matter of investigators' studies. Methods: In 48-hour Holter ECG monitoring recordings of 63 patients, we assessed repeatability, comparing the results from both sleep periods. Results: We found good repeatability in evaluation of apnea-hypopnea index value. There was moderate agreement in three categories, that is, normal or bordeline or apneic assignment. Assignment to "healthy" (normal and borderline) or apneic subgroup during consecutive sleep periods showed high repeatability. Conclusions: Holter ECG monitoring is a repetitive method of preliminary diagnosis in patients evaluated for sleep apnea syndrome. Ann Noninvasive Electrocardiol 2010;15(3):218,222 [source]


New paediatric contrast test: Hiding Heidi low-contrast ,face' test

CLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 5 2003
Clinical Research
ABSTRACT Background:,The Hiding Heidi low-contrast ,face' test is a new paediatric contrast test to evaluate the ability to detect objects with low contrast. The purpose of the present study was to compare the Hiding Heidi low-contrast ,face' test (HH) with the Pelli,Robson contrast sensitivity test (PR) and the functional acuity contrast test (FACT) in the low-contrast assessment. Methods:,Thirty university students participated in the present study. The contrast ability was evaluated by using three different methods: HH, PR and FACT. The HH was repeated on two separate occasions to test the repeatability. Results:,There was a significant positive correlation between HH and PR (r = 0.65, P < 0.01); between HH and FACT at 6 cycles per degree (c.p.d.; r = 0.64, P < 0.01); between HH and FACT at 3 c.p.d. (r = 0.91, P < 0.01); and between HH and FACT at 1.5 c.p.d. (r = 0.56, P < 0.01). The paired t -test showed a significant difference between HH and PR (t = ,6.05, P < 0.01); between HH and FACT at 6 c.p.d. (t = ,11.16, P < 0.01); between HH and FACT at 3 c.p.d. (t = ,8.35, P < 0.01); and between HH and FACT at 1.5 c.p.d. (t = ,5.64, P < 0.01). They had good agreement. The HH had a high repeatability. Conclusions:,The HH had a positive correlation but produced significantly different readings when compared with FACT and PR. The features and role of HH in clinical contrast sensitivity assessment are discussed. [source]