Effects Of Intensity Level Research Articles

Effect of Intensity Level on Dose in Intensity-modulated Radiotherapy for Nasopharyngeal Carcinoma

Effect of Intensity Level on Dose in Intensity-modulated Radiotherapy for Nasopharyngeal Carcinoma

Effect of low and high concentrate supplementation on health and welfare indicators in different breeds in small-scale mountain dairy farms.

We investigated and compared the effects of low and high concentrate supplementation in terms of animal welfare, health and reproductive performance in two different dairy cow breeds on small-scale mountain farms. 64 South Tyrolean dairy farms were evaluated using an on-farm assessment for animal-based and resource-based welfare indicators, data from test day records, and a questionnaire for the farmer. Farms were divided into four groups: low input Tyrolean Grey (L-TG), low input Brown Swiss (L-BS), high input Tyrolean Grey (H-TG) and high input Brown Swiss (H-BS). Effects of intensity level, breed and their interaction were calculated and analyzed statistically. The predominant husbandry system across all groups was tie-stall. The average energy-corrected milk yield increased with increasing concentrate level, with L-TG showing the lowest and H-BS showing the highest milk yield. Age at first calving was lowest in H-BS when compared to all other systems, while numbers of lactations were higher in L-TG compared to H-BS. Feed efficiency (percentage of milk out of roughage) was significantly higher in L-TG and L-BS when compared to H-TG and H-BS. L-BS showed the poorest results for most of the welfare indicators such as lean cows, lesions and percentage of dirty animals. In conclusion, a higher concentrate level in diets does not lead automatically to lower animal welfare for dairy cows in alpine regions. Indeed, keeping high yielding breeds in extensive systems seems to be challenging. The dual-purpose breed TG showed some clear advantages in that calving interval was lower and the number of lactations greater.

Different light spectra and intensity level effects on vegetative growth and antioxidant content of coriander

Different light spectra and intensity level effects on vegetative growth and antioxidant content of coriander

Effect of Intensity Level and Speech Stimulus Type on the Vestibulo-Ocular Reflex.

Accurate vestibulo-ocular reflex (VOR) measurement requires control of extravestibular suppressive factors such as visual fixation. Although visual fixation is the dominant suppressor and has been extensively studied, the mechanisms underlying suppression from nonvisual factors of attention and auditory stimulation are less clear. It has been postulated that the nonvisual suppression of the VOR is the result of one of two mechanisms: (1) activation of auditory reception areas excites efferent pathways to the vestibular nuclei, thus inhibiting the VOR or (2) cortical modulation of the VOR results from directed attention, which implies a nonmodality-specific process. The purpose of this research was to determine if the VOR is affected by the intensity level and/or type of speech stimulus. A repeated measures design was used. The experiment was single-blinded. Participants included 17 adults (14 females, three males) between the ages of 18-34 years who reported normal oculomotor, vestibular, neurological, and musculoskeletal function. Each participant underwent slow harmonic acceleration testing in a rotational chair. VOR gain was assessed at 0.02, 0.08, and 0.32 Hz in quiet (baseline). VOR gain was also assessed at each frequency while a forward running speech stimulus (attentional) or a backward running speech stimulus (nonattentional) was presented binaurally via insert earphones at 42, 62, and 82 dBA. The order of the conditions was randomized across participants. VOR difference gain was calculated as VOR gain in the auditory condition minus baseline VOR gain. To evaluate auditory efferent function, the medial olivocochlear reflex (MOCR) was assayed using transient-evoked otoacoustic emissions (right ear) measured in the presence and absence of broadband noise (left ear). Contralateral acoustic reflex thresholds were also assessed using a broadband noise elicitor. A three-way repeated measures analysis of variance was conducted to evaluate the effect of frequency, intensity level, and speech type on VOR difference gain. Correlations were conducted to determine if difference gain was related to the strength of the MOCR and/or to the acoustic reflex threshold. The analysis of variance indicated that VOR difference gain was not significantly affected by the intensity level or the type of speech stimulus. Correlations indicated VOR difference gain was not significantly related to the strength of the MOCR or the acoustic reflex threshold. The results were in contrast to previous research examining the effect of auditory stimulation on VOR gain as auditory stimulation did not produce VOR suppression or enhancement for most of the participants. Methodological differences between the studies may explain the discrepant results. The removal of an acoustic target from space to attend to may have prevented suppression or enhancement of the VOR. Findings support the hypothesis that VOR gain may be affected by cortical modulation through directed attention rather than due to activation of efferent pathways to the vestibular nuclei.

Aging effects on the ability to use temporal context in speech perception

Elderly and young adults listened to a continuum of stimuli varying in closure duration from “rabid” to “rapid” presented at fast and normal speaking rates, with a carrier phrase and in isolation. Rates for the phrase and word were either consistent or conflicting, to determine the relative influence of extrinsic versus intrinsic temporal cues. In addition, the effect of intensity level was examined for all the above conditions. Hearing sensitivity was within normal limits through the low‐pass cutoff frequency (3.15 kHz) for the filtered speech. In contrast to previous findings with isolated words [P. J. Price and H. J. Simon, J. Acoust. Soc. Am. 76, 406–509 (1984)], no significant overall age effects were seen for either the word alone conditions at the higher intensity or for any of the phrase + word conditions. These results suggest that, when hearing sensitivity is controlled, age per se may not explain the increased difficulty that many elderly have in processing fast speech. Follow‐up research is planned to determine why these data conflict with previous findings.

Effects of Intensity Level on Threshold Shifts Produced by Pulsed and Continuous Maskers

The effect of pulsed versus continuous maskers as a function of intensity level was investigated. The test signals were pulsed or continuous pure tones at the frequencies of 250, 1000, and 4000 cps. A wide-band random noise was presented either to the test ear (monotic) or the contralateral ear (dichotic) of four trained observers at intensity levels of 15, 30, 45, 60, and 75 dB SPL. Three methods of presentation included: (1) pulsed tone and pulsed masker (simultaneous); (2) pulsed tone and continuous masker; and (3) continuous tone and continuous masker. The results from the monotic and dichotic conditions showed that (a) for a pulsed tone signal the pulsed masker was more effective even at the low intensity levels, and (b) a continuous masker produced greater masking in the high frequencies if the tone signal was also continuous. During the dichotic condition, increased threshold shifts were observed as the intensity level of the noise increased. This result was most evident for the pulsed-pulsed and continuous-continuous presentations. The differential effects of frequency were considered in the interpretation of the results. [This work was supported by the National Institutes of Health, U. S. Department of Health, Education, and Welfare.]