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K Forrest

Publications and source records attributed to K Forrest.

27 records · Page 2Linked to original sources
PubMed1989

Age of cow and age of dam effects on milk production of Hereford cows.

Milk production in Hereford cows was studied utilizing 2,487 lactation records on 926 cows. Data were collected over 17 yr (1968 to 1984) from two related herds. Estimates of daily milk yield were obtained at bimonthly intervals by the calf suckling technique. The sum of three monthly measures (TMY), a predicted sum of seven monthly observations (PMY) and 205-d weight of the calf were studied. Year, age of cow, age of dam at cow's birth and calf birth weight affected (P less than .05) all traits. Birth weight affected all measures of milk, with heavier calves obtaining more milk. Age of cow effects were significantly curvilinear, with PMY and TMY increasing for cows from 2 to 5 yr of age, but not differing for cows 6 yr and older. Age of cow effects on 205-d weight were similar to those for milk. As age of cow increased from 2 to 4 yr, 205-d calf weight increased. A leveling off in 205-d weight was observed for calves of cows 5 yr and older. Effects of age of dam of cow also were significant for all milk traits studied. As age of dam increased, PMY and TMY decreased. Highest milk yields were for cows born to and reared by 2-yr-old dams, intermediate milk yields for those by 3- and 4-yr-old dams and lowest yields by daughters of mature dams. Cows born to and reared by older dams produced less milk and weaned lighter calves. There were no interactions between age of cow and age of dam. This suggests a lasting detrimental effect of older cows on lactation yield of daughters. Thus, it appears that age of dam should be considered in evaluation of cow performance.

Age Factors↗
PubMed1988

Acoustic and perceptual analysis of word-initial stop consonants in phonologically disordered children.

Spectrographic measures of voice onset time (VOT) were made for phonologically disordered children in whom a voicing contrast was just beginning to emerge. These temporal measures were related to adult listeners' perception of voicing of the initial stop consonant to determine how well VOT could predict perceived voicing. In general, the predictive utility of VOT was not very high. The relation between VOT as produced by the phonologically disordered children and perceived voicing ranged from 0.31 to 0.43. A finer-grained analysis was conducted to determine what other acoustic cues might have influenced the listeners' judgments of voicing. Although no one acoustic cue could be found to explain all listeners' responses, spectral cues such as fundamental and F1 frequencies at the onset of voicing, as well as the burst and aspiration amplitude relative to the vowel onset amplitude accounted for the perceived voicing of about half of the tokens that were not differentiated by VOT. Rather than relying solely on the temporal characteristics of the VOT interval, a matrix of acoustic cues may influence how a listener perceives word-initial voicing as produced by phonologically disordered children.

Adult↗
PubMed1988

Statistical analysis of word-initial voiceless obstruents: preliminary data.

A statistical procedure for classifying word-initial voiceless obstruents is described. The data set to which the analysis was applied consisted of monosyllabic words starting with a voiceless obstruent. Each word was repeated six times in the carrier phrase "I can say again" by each of ten speakers. Fast Fourier transforms (FFTs), using a 20-ms Hamming window, were calculated every 10 ms from the onset of the obstruent through the third cycle of the following vowel. Each FFT was treated as a random probability distribution from which the first four moments (mean, variance, skewness, and kurtosis) were computed. Moments were calculated from linear and Bark transformed spectra. Data were pooled across vowel contexts for speakers of a given gender and input to a discriminant analysis. Using the moments calculated from the linear spectra, 92% of the voiceless stops were classified correctly when dynamic aspects of the stop were included. Even more important, the model constructed from the males' data correctly classified about 94% of the voiceless stops produced by the female speakers. Classification of the voiceless fricatives when all places of articulation were included in the analysis did not exceed 80% correct when the moments from either the linear or Bark transformed scales were used. However, classification of only the voiceless sibilants was 98% correct when the moments from the Bark transformed spectra were used. As with the stops, the classification model held across gender.

Adolescent↗
PubMed1987

Men's reproductive health services in family planning settings: a pilot study.

A 1984 pilot survey of administrators of 35 agencies offering family planning services revealed that all offered counseling/educational services for males, and 89 per cent offered medical/supply services for males. Nevertheless, total utilization of these services is low. Major barriers related to the provision of services to male clients are resource limitations, inadequate training, and negative or ambivalent staff attitudes; these factors may contribute to the discrepancy between service offering and utilization.

Contraceptive Devices, Male↗
PubMed1986

Effects of white noise masking and low pass filtering on speech kinematics.

The effects of reduced auditory information on spatial and temporal parameters of speech production were investigated using cinefluorographic techniques. While subjects read a series of test words embedded in carrier sentences, they received normal auditory information, auditory information regarding only the first formant of their production, or high level noise to mask all formant information. Kinematic analyses indicated that while there were some changes across conditions, these changes were not consistent either within or across the subjects. Parameters that were affected included mean displacement, vocal tract shape, interarticulator timing, and steady state duration. The results suggest that auditory information plays a role in maintaining dynamic aspects of speech kinematics. That is, while speech can be produced without auditory information, the precise action and coordination that characteristic normal production may be altered.

Adult↗