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Biomedical subjects

M Meir

Publications and source records attributed to M Meir.

10 recordsLinked to original sources
PubMed1999

Effects of drilling holes into the air cell of incubated goose eggs on distribution of oxygen partial pressures under the shell.

The purpose of this work was to measure changes in oxygen pressure in the air cell and under the eggshell (P(A)O2) of pre-pipping goose eggs before and after drilling holes into the air cell. Drilling a 0.6 mm (diameter of 0.9 mm) hole into the air cell caused an increase in air cell P(A)O2 of about 10 Torr. The rate of increase attenuated as hole area increased and reached about 21 Torr when the drilled area was 8.5 mm2. The P(A)O2 of intact eggs was not equally distributed under the shell. It was high in the air cell area (108 Torr) and decreased towards the pointed end (86 Torr). The increase in P(A)O2 after drilling a 4.9 mm2 hole was high in the air cell (18 Torr) and decreased with distance, becoming non-significant at the pointed end. The significant increase in P(A)O2 after drilling was limited to a distance of up to 38 mm along the shell from the edge of the air cell. This indicates that lateral diffusion in the shell membranes under the shell is limited. Drilling a hole of 3.5 to 4.9 mm2 was enough to increase air cell P(A)O2 in most of the eggs above the critical value of 100 Torr for hatching success. The increase in P(A)O2 was limited to about half the area of the shell and the average increase in P(A)O2 was 6.3 Torr (equivalent to a 0.9% increase in ambient O2). However, the blood perfusing chorioallantoic areas further away from the air cell edge may not be fully saturated with O2 and may not be sufficient to compensate fully for the low O2 availability caused by low eggshell conductance.

Animals↗
PubMed1998

How automatic is manual gear shifting?

Manual gear shifting is often used as an example of an automated (vs. controlled) process in driving. The present study provided an empirical evaluation of this assumption by evaluating sign detection and recall performance of novice and experienced drivers driving manual shift and automatic transmission cars in a downtown area requiring frequent gear shifting. The results showed that manual gear shifting significantly impaired sign detection performance of novice drivers using manual gears compared with novice drivers using an automatic transmission, whereas no such differences existed between the two transmission types for experienced drivers. The results clearly demonstrate that manual gear shifting is a complex psychomotor skill that is not easily (or quickly) automated and that until it becomes automated, it is an attention-demanding task that may impair other monitoring aspects of driving performance. Actual or potential applications of this research include a reevaluation of the learning process in driving and the need for phased instruction in driving from automatic gears to manual gears.

Adolescent↗
PubMed1997

Reported health concerns of Israeli high school students--differences by age and sex.

Health concerns of high school students in the 10th grade and again in the 12th grade were studied. The students filled out an anonymous questionnaire that included a list of 73 concerns. At both ages their main concerns were reportedly related to school. Concerns relating to army service ranked high particularly in the 12th grade, among both sexes. Concerns relating to sexual relations were frequent among boys at both ages, whereas concerns about mood and loneliness were more frequent among girls. Reports on physical concerns were frequently related to height among the younger boys and weight and diet among girls of both ages. Concerns were grouped into 6 domains. In each of them, except for sexuality, girls had more concerns. A significant decline in the number of concerns was noted from the first to the second survey, indicating a partial resolution of the issues central to adolescent development. Knowledge about concerns of adolescents may help health care providers in counseling and health education program planning.

Adaptation, Psychological↗
PubMed1996

Artificial increase of eggshell conductance improves hatchability of early laid goose eggs.

1. The purpose of this work was to test the possibility of increasing the hatchability of goose eggs with low mass specific eggshell gas conductance (Gsp), by drilling holes through the eggshell into the air cell, and thus solving both the low water loss rate and low oxygen availability problems. 2. A linear relationship was found between the area of a hole drilled and the apparent increase in eggshell gas conductance (G). Drilling more than one hole increased apparent G 3-6 times more than one hole only, of the same total area. 3. Hole-drilling did not increase egg contamination. The drilling of a 5 mm2 hole on day 17 of incubation increased hatchability both in laboratory tests and in commercial hatcheries (6.1% and 10.5% respectively). 4. Drilling holes on days 15 to 22 of incubation increased hatchability when the predicted mean water loss was lower than 14%. Drilling on day 25 did not have a significant effect, and drilling on day 11 of incubation was too early. 5. Drilling a hole into the aircell (during the second half of incubation) may increase hatchability of low conductance eggs, although oxygen pressure under the eggshell should then be checked in order to evaluate oxygen availability to the embryo.

Animals↗
PubMed1995

Concerns and risk behaviors and the association between them among high-school students in Jerusalem.

PURPOSE: To study the distribution, prevalence, determinants, and association between the health, social, and environmental concerns and risk behaviors of high school students in Jerusalem in order to provide a better basis for preventive and health promotion services. METHODS: 1078 tenth grade high school students, 15-16 years old answered an anonymous questionnaire including, perceived concerns and risk behaviors, (e.g., smoking, alcohol, drugs, and sexual activity). Concerns were grouped into six domains. RESULTS: The most frequently reported concerns related to school, weight, coping with aggression, fatigue, war, enlistment into army, and relationships with peers. Girls had more concerns in the domains of self-image, anxiety, and relationships with peers (p < .05). Adolescents with mothers who had less education had significantly more concerns in the domains of anxiety and relationships with peers and adults (p < .05). Forty-seven percent engaged in at least one risk behavior (boys 63% and girls 34%). The Guttman scalogram indicated the following sequence of risk behaviors: alcohol, cigarettes, sex, and drugs. There were statistically significant associations between concerns and risk behaviors in the domains of anxiety, sex, and relationships with adults and peers. CONCLUSION: Many adolescent concerns are universal, although the ranking and prevalence may vary based on different regional and population characteristics (e.g., in this population a high rate of concerns relating to aggression and war were identified). The results support the need to develop prevention and health promotion programs relating to the concerns and risk behaviors in the school and community, and individual counseling programs in primary care settings.

Adolescent↗
PubMed1987

Improving turkey poult quality by correcting incubator humidity to match eggshell conductance.

One of the most important factors determining hatchability of avian eggs is their proper water budget during incubation. We show here that water budget changes of turkey eggs effect not only hatchability but also poult quality. In addition to an increase in hatchability of 3.3%, poult quality was increased by 7.3%. This was achieved by sorting eggs into low (less than 18.5), medium (18.5 to 22.0) and high (greater than 22.0) eggshell mass-specific water vapour, conductance categories and incubating them in matching incubation humidities of 21.8, 26.6 and 31.4 Torr, corresponding to relative humidities of 45, 55 and 65% at 37.5 degrees C, respectively. A total diffusive water loss of 11.5% (range 10 to 14%) of the initial egg mass in 25 d of incubation yielded maximal hatchability and poult quality.

Animals↗
PubMed1984

Increasing hatchability of turkey eggs by matching incubator humidity to shell conductance of individual eggs.

One of the most important factors determining hatchability of avian eggs is the proper water balance of the eggs during incubation. In turkey eggs, a total diffusive water loss (F) of 12 +/- 1% SD initial egg mass in 28 days, yielded maximal hatchability irrespective of the combination of eggshell water vapor conductance (G) and incubator humidity (PI), which brought about this water loss. A good correlation was found between G as obtained at the beginning of incubation and the final F in a given PI. The G in a random sample of 1256 fresh turkey eggs was normally distributed around the mean of 18.70 +/- 2.87 SD milligrams (100 g X day X torr)-1 (Coefficient of variation = 15.3%). The distribution of G in eggs with dead in the shell embryos had, in addition, two more peaks of G values [around 22.5 and 13.0 mg (100 g X day X torr)-1]. When eggs were sorted into low (less than 17), medium (17 to 20), and high (greater than 20) G categories, and incubated at low (19.4), medium (26.6), and high (33.9) torr PI, respectively, hatchability increased by a factor of 1.08. Poor hatchabilities were obtained in mismatching humidities and conductances. It seems that hatchability success may be experimentally improved if a correct rate of water loss is fitted to sorted eggs during incubation.

Animals↗
PubMed1977

A relationship between motor control and language development in an autistic child.

Recent work in both experimental and clinical psychology indicates an important link exists between the development of motor control and language development. Diagnostic and therapeutic work with autistic children reveals a high incidence of gross motor dysfunction along with language deficits. A study to evaluate the effectiveness of behavior modification techniques in eliciting speech from nursery-age autistic children yielded new data to confirm the importance of the relationship. Results from a case study of one autistic child demonstrated that the child most frequently vocalized when motorically quiet, and engaged in motor activity when not speaking and especially prior to speech. Data from 30 half-hour behavior modification sessions and an intensive clinical interview indicated that limiting the child's gross motor activity was effective in increasing the frequency of vocalization. Several theoretical interpretations of this phenomenon as well as implications for treatment and further research are offered.

Autistic Disorder↗