Average Frequency (average + frequency)

Distribution by Scientific Domains


Selected Abstracts


Cross-Sectional and Longitudinal Studies of the Development of Group Differences in Acoustic Features of Coo Calls in Two Groups of Japanese Macaques

ETHOLOGY, Issue 1 2006
Toshiaki Tanaka
Japanese macaques, Macaca fuscata, frequently utter coo calls to maintain vocal contact. Cross-sectional and longitudinal comparisons were conducted on the acoustic features of coo vocalizations of two groups of M. fuscata, Yakushima and Ohirayama groups, to explore the possibility of vocal plasticity. These two groups derive from the same local population but have been separated for more than 34 yr. The Yakushima group is non-provisioned, while the Ohirayama group is provisioned. Initially, coo calls in the two groups were compared cross-sectionally in females ranging from 0 to 18 yr. Mean values of the four variables studied (start, end, maximum, and minimum frequencies) were consistently lower in all age groups of the Ohirayama individuals compared with the Yakushima individuals. Secondly, longitudinal comparisons were conducted on individuals in the 1,4 yr after birth. Mean values of the five frequency variables studied (start, end, maximum, minimum and average frequencies) were again consistently lower in all age groups of Ohirayama compared with Yakushima individuals, although mean values of both groups gradually declined with an increase in age. Inter-group differences were significant at all ages in minimum frequency and at the first, second and third years in start frequency. Longitudinal comparisons of individuals aged 4,11 mo were also conducted. Regarding the four variables that differed between the two groups in the cross-sectional study, the mean values of minimum and start frequency did not differ significantly between the two groups at 4,5 mo, but were significantly lower in Ohirayama individuals aged 7,8 and 9,11 mo. Although provisioning may have had an effect on the weight difference between the groups, and consequently on vocalization frequency, these results suggest that the inter-group differences in coo call features form approximately 6,7 mo after birth as a result of vocal plasticity. [source]


Nicotine as an Antiepileptic Agent in ADNFLE: An N-of-One Study

EPILEPSIA, Issue 9 2003
John O. Willoughby
Summary:,Purpose: To test nicotine patch treatment for a patient with a defined mutation for autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) whose seizures were refractory to standard antiepileptic therapy. Methods: Open and double-blind trials of nicotine patches in an "n-of-one" study. The double-blind trial comprised periods during which either placebo or nicotine patches were each used for three periods of 2 weeks, randomized in a double-blind manner. Results: In an open study, nicotine patches reduced seizures from 1.65 ± 2.36 to 0.01 ± 0.0 seizures per day (p < 0.0001). In a double-blinded placebo-controlled phase, the average frequency of seizures on nicotine versus placebo was 0 ± 0 versus 0.56 ± 1.14 seizures per day (p < 0.0001). Conclusions: Nicotine patches may be of benefit to some individuals with ADNFLE. [source]


Suppression of HCV-specific T cells without differential hierarchy demonstrated ex vivo in persistent HCV infection

HEPATOLOGY, Issue 6 2003
Kazushi Sugimoto
Hepatitis C virus (HCV) has a high propensity for persistence. To better define the immunologic determinants of HCV clearance and persistence, we examined the circulating HCV-specific T-cell frequency, repertoire, and cytokine phenotype ex vivo in 24 HCV seropositive subjects (12 chronic, 12 recovered), using 361 overlapping peptides in 36 antigenic pools that span the entire HCV core, NS3-NS5. Consistent with T-cell-mediated control of HCV, the overall HCV-specific type-1 T-cell response was significantly greater in average frequency (0.24% vs. 0.04% circulating lymphocytes, P = .001) and scope (14/36 vs. 4/36 pools, P = .002) among the recovered than the chronic subjects, and the T-cell response correlated inversely with HCV titer among the chronic subjects (R = ,0.51, P = .049). Although highly antigenic regions were identified throughout the HCV genome, there was no apparent difference in the overall HCV-specific T-cell repertoire or type-1/type-2 cytokine profile relative to outcome. Notably, HCV persistence was associated with a reversible CD4-mediated suppression of HCV-specific CD8 T cells and with higher frequency of CD4+CD25+ regulatory T cells (7.3% chronic vs. 2.5% recovered, P = .002) that could directly suppress HCV-specific type-1 CD8 T cells ex vivo. In conclusion, we found that HCV persistence is associated with a global quantitative and functional suppression of HCV-specific T cells but not differential antigenic hierarchy or cytokine phenotype relative to HCV clearance. The high frequency of CD4+CD25+ regulatory T cells and their suppression of HCV-specific CD8 T cells ex vivo suggests a novel role for regulatory T cells in HCV persistence. [source]


A case,control study on the dietary intake of mushrooms and breast cancer risk among Korean women

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2008
Seo Ah Hong
Abstract To evaluate the association between dietary mushroom intake and breast cancer risk, a total of 362 women between the ages of 30 and 65 years who were histologically confirmed to have breast cancer were matched to controls by age (±2 years) and menopausal status. Mushroom intake was measured via a food frequency questionnaire that was administered by well-trained interviewers. The associations between the daily intake and the average consumption frequency of mushrooms with breast cancer risk were evaluated using matched data analysis. Both the daily intake (5th vs. 1st quintile, OR = 0.48, 95% CI = 0.30,0.78, p for trend 0.030) and the average consumption frequency of mushrooms (4th vs. 1st quartile, OR = 0.54, 95% CI = 0.35,0.82, p for trend 0.008) were inversely associated with breast cancer risk after adjustment for education, family history of breast cancer, regular exercise [,22.5 MET (metabolic equivalent)-hr/week], BMI (body mass index, Kg/m2), number of children and whether they are currently smoking, drinking or using multivitamin supplements. Further adjustments were made for energy-adjusted carbohydrate, soy protein, folate and vitamin E levels, which tended to attenuate these results. After a stratification was performed according to menopausal status, a strong inverse association was found in postmenopausal women (OR = 0.16, 95% CI = 0.04,0.54, p for trend = 0.0058 for daily intake; OR = 0.17, 95% CI = 0.05,0.54, p for trend = 0.0037 for average frequency), but not in premenopausal women. In conclusion, the consumption of dietary mushrooms may decrease breast cancer risk in postmenopausal women. © 2007 Wiley-Liss, Inc. [source]


Mapping snow characteristics based on snow observation probability

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2007
Bahram Saghafian
Abstract Measurement/estimation of snow water equivalent (SWE) is a difficult task in water resources studies of snowy regions. SWE point data is measured at snow courses that are normally operated with low density owing to high costs and great difficulty in reaching the stations in cold seasons. Moreover, snow is known to exhibit high spatial variability, which makes SWE studies based solely on sparse station data more uncertain. Ever-increasing availability of satellite images is a promising tool to overcome some of the difficulties associated with analyzing spatial variability of snow. Although National Oceanic and Atmospheric Administration (NOAA) satellite images have low spatial resolution with approximately 1.1-km pixel size, they are adequate for mapping snow cover at regional scales and enjoy a moderate length of record period. In this paper, rain and snow records of synoptic stations and the time series of NOAA-based snow cover maps were used to map average SWE of a vast area in southwestern Iran. First, monthly and annual snow coefficient (SC) at synoptic stations were determined on the basis of analysis of hourly observation of type and amount of precipitation. Then, two new spatially distributed snow characteristics were introduced, namely, average frequency of snow observation (FSO) and monthly frequency of maximum snow observation (FMSO), on the basis of existing satellite snow observations. FSO and monthly FMSO maps were prepared by a geographic information system on the basis of snow map time series. Correlation of these two parameters with SC was studied and spatial distribution of SC was estimated on the basis of the best correlation. Moreover, the distribution of mean annual precipitation was derived by comparing a number of interpolation methods. SWE map was generated by multiplying SC and precipitation maps and its spatial variability in the region was analyzed. Copyright © 2007 Royal Meteorological Society [source]


Analysis of circadian variation of acute myocardial infarction: afternoon predominance in Turkish population

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 1 2009
I. Sari
Summary Background:, Although data about circadian variation of myocardial infarction (MI) in western populations reveal morning peak between 06:00 and 12:00 hours, differences have been reported in different regions of the world and ethnic groups. We aimed to evaluate circadian variation of MI in a Turkish cohort. Methods:, A total of 476 patients (mean age 56.7 ± 11.7; 80% men) with acute st elevation MI were included into the study. Patients were categorised into four 6-h increments (00:01,06:00; 06:01,12:00; 12:01,18:00 and 18:01,24:00 hours). Results:, Onset of MI exhibited significant circadian variation among four time periods (p < 0.001), demonstrating afternoon peak (between 12:01 and 18:00 hours) and trough between 00:01 and 06:00 hours. Incidence of MI between 12:01 and 18:00 hours was significantly higher when compared with other three 6-h periods (p = 0.001). Incidence of MI between 00:01 and 06:00 hours was significantly lower when compared with other three 6-h periods (p = 0.001). Incidence of MI between 12:01 and 18:00 hours was 1.64 times that of average frequency of the remaining 18:00 hours of the day and 2.3 times that of frequency between 00:01 and 06:00 hours. When analysed for the subgroups of the study sample, only smoking blunted the afternoon peak. Conclusions:, Instead of early morning peak in western countries, there is afternoon predominance in circadian variation of MI in a Turkish cohort. It may be related with genetic and/or demographic characteristics of Turkish population. Further studies are required to determine underlying pathophysiological mechanisms causing these differences in chronobiology of MI among populations. [source]


Detecting regime transitions in slurry bubble columns using pressure time series

AICHE JOURNAL, Issue 7 2005
Keshav C. Ruthiya
Abstract Changes in the coherent standard deviation and in the average frequency of measured pressure time series with gas velocity, are proposed, as unique and unambiguous criteria to mark flow regime transitions in slurry bubble columns. In a 2-dimensional (2-D) slurry bubble column, pressure time series are measured at different gas velocities simultaneously with high-speed video recording of the gas-liquid flow. The frequency of occurrence and the average diameter of the large bubbles are determined from video image analysis. The gas velocity where the first large bubbles are detected, with an average diameter of 1.5 cm, and with a frequency of occurrence of one bubble per s, is designated as the first regime transition point (transition from the homogeneous regime to the transition regime). At this point, the coherent standard deviation of the measured pressure fluctuations clearly increases from zero. The gas velocity where the average diameter and the frequency of occurrence of the large bubbles become constant, is designated as the second regime transition point (transition from the transition regime to the heterogeneous regime). From this point onward, the slope of the coherent standard deviation of the measured pressure fluctuations clearly decreases with gas velocity, while the average frequency becomes constant. These clear changes with gas velocity in the coherent standard deviation, and in the average frequency are also demonstrated in a 3-D slurry bubble column. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source]


Interactions between visitors and Formosan macaques (Macaca cyclopis) at Shou-Shan Nature Park, Taiwan

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009
Minna J. Hsu
Abstract Ecotourism involving feeding wildlife has raised public attention and is a controversial issue, especially concerning nonhuman primates. Between July 2002 and April 2005, the behavior of monkeys and tourists was collected through scan samplings, focal samplings and behavior samplings at the Shou-Shan Nature Park located in Taiwan's second largest city,Kaohsiung. In addition, the number of tourists and monkeys was counted in different hours and places within the park. Four hundred visitors were interviewed using a questionnaire to gather data on sex, age, purpose and frequency of visit to the park. The number of tourists was significantly higher during weekends than in weekdays in all locations. Humans dominated in the initiation of interspecies interactions,the overall ratio of human-initiated and monkey-initiated interactions was 2.44:1. Human,monkey conflicts accounted for only 16.4% of the total interactions (n=2,166), and adult human males and adult male macaques participated in higher rates than other age/sex groups in these conflicts. Visitors showed more affiliative behavior (15.9%) than agonistic behavior (8%) toward the macaques. In response to visitors' threat or attack, the Formosan macaques mostly showed submissive behavior with bared teeth, squealed or ran away to avoid confrontation (69.1%),only few responded with counteraggression (18.7%). This study for the first time provided evidence that food provisioning increased both the frequency and duration of aggression among Formosan macaques (P<0.001). During food provisioning, the average frequency and the duration of agonistic events of macaques were more than 4 times higher compared with those without food provisioning. The average frequency of food provision by tourists was 0.73,times/hr,more than twice the incident that monkeys grabbed the food from tourists (0.34,times/hr). If people refrain from feeding monkeys and destroying the city park's natural vegetation, monkeys can be used to educate public about nature conservation in an urban setting. Am. J. Primatol. 71:214,222, 2009. © 2008 Wiley-Liss, Inc. [source]


Rapid identification of Arabidopsis insertion mutants by non-radioactive detection of T-DNA tagged genes

THE PLANT JOURNAL, Issue 2 2002
Gabino Ríos
Summary To assist in the analysis of plant gene functions we have generated a new Arabidopsis insertion mutant collection of 90 000 lines that carry the T-DNA of Agrobacterium gene fusion vector pPCV6NFHyg. Segregation analysis indicates that the average frequency of insertion sites is 1.29 per line, predicting about 116 100 independent tagged loci in the collection. The average T-DNA copy number estimated by Southern DNA hybridization is 2.4, as over 50% of the insertion loci contain tandem T-DNA copies. The collection is pooled in two arrays providing 40 PCR templates, each containing DNA from either 4000 or 5000 individual plants. A rapid and sensitive PCR technique using high-quality template DNA accelerates the identification of T-DNA tagged genes without DNA hybridization. The PCR screening is performed by agarose gel electrophoresis followed by isolation and direct sequencing of DNA fragments of amplified T-DNA insert junctions. To estimate the mutation recovery rate, 39 700 lines have been screened for T-DNA tags in 154 genes yielding 87 confirmed mutations in 73 target genes. Screening the whole collection with both T-DNA border primers requires 170 PCR reactions that are expected to detect a mutation in a gene with at least twofold redundancy and an estimated probability of 77%. Using this technique, an M2 family segregating a characterized gene mutation can be identified within 4 weeks. [source]


Growth inhibition of dinoflagellate algae in shake flasks: Not due to shear this time!

BIOTECHNOLOGY PROGRESS, Issue 1 2010
Weiwei Hu
Abstract Large scale algae cultures present interesting challenges in that they exhibit characteristics of typical bacterial and animal cell cultures. One current commercial food additive, docosahexaenoic acid (DHA), is produced using the dinoflagellate algae, Crypthecodiniumcohnii. Like animal cell culture, the perceived sensitivity of algae culture to hydrodynamic forces has potentially limited the agitation and aeration applied to these systems. However, the high density cultivation of C. cohnii required for an economically feasible process inevitably results in high oxygen demand. In this study, we demonstrated what first appeared to be a problem with shear sensitivity in shake flasks is most probably a mass transfer limitation. We subsequently demonstrated the limit of chronic and rapid energy dissipation rate, EDR, that C. cohnii cells can experience. This limit was determined using a microfluidic device connected in a recirculation loop to a stirred tank bioreactor, which has been previously used to repeatedly expose animal cells to high levels of EDR. Inhibition of cell growth was observed when C. cohnii cells were subjected to an EDR of 5.9 × 106 W/m3 with an average frequency of 0.2/min or more. This level of EDR is sufficiently high that C. cohnii can withstand typically encountered hydrodynamic forces in bioprocesses. This result suggests that at least one dinoflagellate algae, C. cohnii, is quite robust with respect to hydrodynamic forces and the scale-up of process using this type of algae should be more concerned with providing sufficient gas transfer given the relatively high oxygen demand. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source]