BODY DRAG, FEATHER DRAG AND INTERFERENCE DRAG OF THE MOUNTING STRUT IN A PEREGRINE FALCON,FALCO PEREGRINUS

1990 ◽  
Vol 149 (1) ◽  
pp. 449-468 ◽  
Author(s):  
VANCE A. Tucker
Keyword(s):  
The Body ◽  
Peregrine Falcon ◽  
Reference Area ◽  
Drag Coefficients ◽  
Minimum Drag ◽  
Body Drag ◽  
The Mean ◽  
The Difference ◽  
Parabuteo Unicinctus ◽  
Crosssectional Area

1. The mean, minimum drag coefficients (CD,B) of a frozen, wingless peregrine falcon body and a smooth-surfaced model of the body were 0.24 and 0.14, respectively, at air speeds between 10.0 and 14.5 ms−1. These values were measured with a drag balance in a wind tunnel, and use the maximum crosssectional area of the body as a reference area. The difference between the values indicates the effect of the feathers on body drag. Both values for CD,B a r e lower than those predicted from most other studies of avian body drag, which yield estimates of CD,B up to 0.41. 2. Several factors must be controlled to measure minimum drag on a frozen body. These include the condition of the feathers, the angle of the head and tail relative to the direction of air flow, and the interference drag generated by the drag balance and the strut on which the body is mounted. 3. This study describes techniques for measuring the interference drag generated by (a) the drag balance and mounting strut together and (b) the mounting strut alone. Corrections for interference drag may reduce the apparent body drag by more than 20%. 4. A gliding Harris' hawk (Parabuteo unicinctus), which has a body similar to that of the falcon in size and proportions, has an estimated body drag coefficient of 0.18. This value can be used to compute the profile drag coefficients of Harris' hawk wings when combined with data for this species in the adjoining paper (Tucker and Heine, 1990).

scholarly journals Tri-Ponderal Mass Index: A Screening Tool for Risk of Central Fat Accumulation in Brazilian Preschool Children

Medicina ◽  
2019 ◽  
Vol 55 (9) ◽  
pp. 577 ◽  
Author(s):  
Viviane Gabriela Nascimento ◽  
Ciro João Bertoli ◽  
Paulo Rogerio Gallo ◽  
Luiz Carlos de Abreu ◽  
Claudio Leone
Keyword(s):  
Preschool Children ◽  
Roc Curve ◽  
Screening Tool ◽  
The Body ◽  
Fat Accumulation ◽  
Central Fat ◽  
The Mean ◽  
The Difference ◽  
The Individual ◽  
Higher Sensitivity

Background and Objectives: To verify the use of the tri-ponderalmass index (TMI) as a screening tool for risk of central fat accumulation in preschool children. Materials and Methods: An observational, analytical study was carried out on samples from children 2 to 5 years of age. The body mass index (BMI) and the tri-ponderalmass index (TMI: Weight/height3) were calculated. The waist circumference-to-height ratio (WHtR) was used to classify central fat accumulation risk. Preschoolers whose WHtRwas in the upper tertile of the sample were classified as at risk for central fat accumulation. A comparison of the two indicators (BMI and TMI) was made from the area under the receiver operator characteristics (ROC) curve (AUC) in the discrimination of the WHtR. Results: The sample used for analysis was 919 preschoolers. The mean age of the children was 3.9 years (SD = 0.7). The difference in AUC was 5% higher for TMI (p < 0.0001). In the individual analysis of the ROC curve of the TMI, favoring a higher sensitivity, the cutoff point of 14.0 kg/m3 showed a sensitivity of 99.3% (95% CI: 97.6–99.9). Conclusion: Considering WHtR as a marker of possible future metabolic risk among preschool children, TMI proved to be a useful tool, superior to BMI, in screening for risk of central fat accumulation in preschool children.

Impaired visual thresholds in hypopigmented animals

1991 ◽  
Vol 6 (6) ◽  
pp. 577-585 ◽  
Author(s):  
Grant W. Balkema ◽  
Ursula C. Dräger
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Visual Sensitivity ◽  
The Body ◽  
Melanin Pigmentation ◽  
Similar Threshold ◽  
The Mean ◽  
Single Unit Recordings ◽  
The Difference ◽  
And Function

AbstractOcular hypopigmentation is associated with neurological defects in structure and function. This paper investigates the ab/Fute visual thresholds in dark-adapted hypopigmented animals compared to their normally pigmented controls. Here we asked (1) whether the threshold elevation found in hypopigmented animals is a general consequence of the reduction in melanin content; (2) if so, which melanin components in the eye are likely to influence visual thresholds; and (3) whether similar threshold defects can be detected in orders other than rodents. By single-unit recordings from the superior colliculus, we compared incremental thresholds of normal black mice of the C57BL/6J strain to hypopigmented mutants: beige (bg/bg), pale ear (ep/ep), and albino (c2J/c2J) mice, three mutants in which melanin pigment throughout the body is affected; and Steel (Sl/Sld) and dorninant-spotting/W-mice (W/Wν), two mutants with normal pigmentation in the retinal pigment epithelium (RPE) but without any melanin in the choroid or the rest of the body. We found that all mutants had elevated thresholds that varied with the reduction in melanin. The albinos were 25 times less sensitive than black mice, pale ear mice 20 times, beige mice 11 times, and Steel and W-mice 5 times. The mean thresholds of dark-adapted black mice were 0.008 cd/m2. Recordings from rabbits showed a similar impairment of visual sensitivity: incremental thresholds were elevated 40 times in New Zealand-White albino rabbits (0.0008 cd/m2) compared to Dutch-Belted pigmented controls (0.00002 cd/m2). Previously, it has been shown that hypopigmented rats have elevated dark-adapted thresholds compared to pigmented controls (Balkema, 1988); here we show that the difference between hypopigmented rats and pigmented controls is not caused by insufficient dark adaptation or excessive variability in the results from albino mutant compared to its control.Mutations that cause a reduction of ocular melanin pigmentation, regardless of the gene mutated or the mechanism underlying the hypopigmentation, are accompanied by an elevation in visual thresholds which is roughly proportional to the reduction in melanin. Melanin both in the RPE and choroid exert an effect on visual thresholds. Like the defects in optic nerve crossing and eye movements, the effect of melanin on visual thresholds is not restricted to rodents, but is seen in other orders. The threshold impairment in hypopigmented animals cannot be explained by impaired photoprotection, but it points to another physiological action of melanin.

The significance of the coat in heat tolerance of cattle. II. Effect of solar radiation on body temperatures

1960 ◽  
Vol 11 (5) ◽  
pp. 871 ◽  
Author(s):  
DF Dowling
Keyword(s):  
Body Temperature ◽  
Solar Radiation ◽  
The Body ◽  
Body Temperatures ◽  
Hair Coat ◽  
Transparent Plastic ◽  
Mean Body Temperature ◽  
Clear Plastic ◽  
The Mean ◽  
The Difference

An experiment was performed to test the effect of solar radiation on the body temperatures of cattle, both clipped and with hair coat, in a clear transparent plastic covering as compared with cattle in a white reflective plastic covering. The mean body temperature of the animals in white plastic coats was 0.15°F lower than that of animals in clear plastic coats. This difference was highly significant statistically (P< 0.001). Animals in both clear and white coats had higher body temperatures than controls without plastic coats. The difference was highly significant, and was about 1.5°F in the clipped animals.

The Body Feature Study of Young Women from Northeastern China

2014 ◽  
Vol 1048 ◽  
pp. 567-570
Author(s):  
Jun Wang ◽  
Xiao Jiu Li ◽  
Xiao Mei Chen ◽  
Tong Yao ◽  
Li Pan
Keyword(s):  
Young Women ◽  
Mean Value ◽  
Northeastern China ◽  
The Body ◽  
3D Scanner ◽  
Mean Values ◽  
Adult Females ◽  
Width Direction ◽  
The Mean ◽  
The Difference

This study aims to investigate the anthropometric feature of young women aged between 18 and 25 from Northeastern China, and compare the difference between the young Northeastern China women and the national adult females. More than 400 young Northeastern China women were measured, and the body data were collected by mix-measurement of 3D scanner and manual method, and the main sizes were extracted to descript the total anthropometric characterizes. The high mean value of the Northeastern young women is 162.3 CM, which is 5.75 CM higher than the national adult females. In the high direction, the other mean values of the samples are variously higher than the national adult females. Overall, the young Northeastern China women are taller than the national adult females and well proportioned. In the width direction, the mean values of bust, waist and neck of the 18-25 years old young women are larger than the national adult females, except the hip.

scholarly journals Air speeds of migrating birds observed by ornithodolite and compared with predictions from flight theory

2013 ◽  
Vol 10 (86) ◽  
pp. 20130419 ◽  
Author(s):  
C. J. Pennycuick ◽  
Susanne Åkesson ◽  
Anders Hedenström
Keyword(s):  
East Coast ◽  
Bird Species ◽  
The Body ◽  
Flight Performance ◽  
Number Range ◽  
Drag Coefficients ◽  
Dead Bird ◽  
Body Drag ◽  
Air Speed ◽  
Migrating Birds

We measured the air speeds of 31 bird species, for which we had body mass and wing measurements, migrating along the east coast of Sweden in autumn, using a Vectronix Vector 21 ornithodolite and a Gill WindSonic anemometer. We expected each species’ average air speed to exceed its calculated minimum-power speed ( V mp ), and to fall below its maximum-range speed ( V mr ), but found some exceptions to both limits. To resolve these discrepancies, we first reduced the assumed induced power factor for all species from 1.2 to 0.9, attributing this to splayed and up-turned primary feathers, and then assigned body drag coefficients for different species down to 0.060 for small waders, and up to 0.12 for the mute swan, in the Reynolds number range 25 000–250 000. These results will be used to amend the default values in existing software that estimates fuel consumption in migration, energy heights on arrival and other aspects of flight performance, using classical aeronautical theory. The body drag coefficients are central to range calculations. Although they cannot be measured on dead bird bodies, they could be checked against wind tunnel measurements on living birds, using existing methods.

scholarly journals Wingbeat frequency and the body drag anomaly: wind-tunnel observations on a thrush nightingale (Luscinia luscinia) and a teal (Anas crecca)

1996 ◽  
Vol 199 (12) ◽  
pp. 2757-2765 ◽  
Author(s):  
C J Pennycuick ◽  
M Klaassen ◽  
A Kvist ◽  
Å Lindström
Keyword(s):  
Wind Tunnel ◽  
The Body ◽  
Wingbeat Frequency ◽  
Cross Sectional ◽  
Number Range ◽  
Drag Coefficients ◽  
Anas Crecca ◽  
Body Drag ◽  
Air Speed ◽  
Thrush Nightingale

A teal (Anas crecca) and a thrush nightingale (Luscinia luscinia) were trained to fly in the Lund wind tunnel for periods of up to 3 and 16 h respectively. Both birds flew in steady flapping flight, with such regularity that their wingbeat frequencies could be determined by viewing them through a shutter stroboscope. When flying at a constant air speed, the teal's wingbeat frequency varied with the 0.364 power of the body mass and the thrush nightingale's varied with the 0.430 power. Both exponents differed from zero, but neither differed from the predicted value (0.5) at the 1 % level of significance. The teal continued to flap steadily as the tunnel tilt angle was varied from -1 &deg; (climb) to +6 &deg; (descent), while the wingbeat frequency declined progressively by about 11 %. In both birds, the plot of wingbeat frequency against air speed in level flight was U-shaped, with small but statistically significant curvature. We identified the minima of these curves with the minimum power speed (Vmp) and found that the values predicted for Vmp, using previously published default values for the required variables, were only about two-thirds of the observed minimum-frequency speeds. The discrepancy could be resolved if the body drag coefficients (CDb) of both birds were near 0.08, rather than near 0.40 as previously assumed. The previously published high values for body drag coefficients were derived from wind-tunnel measurements on frozen bird bodies, from which the wings had been removed, and had long been regarded as anomalous, as values below 0.01 are given in the engineering literature for streamlined bodies. We suggest that birds of any size that have well-streamlined bodies can achieve minimum body drag coefficients of around 0.05 if the feet can be fully retracted under the flank feathers. In such birds, field observations of flight speeds may need to be reinterpreted in the light of higher estimates of Vmp. Estimates of the effective lift:drag ratio and range can also be revised upwards. Birds that have large feet or trailing legs may have higher body drag coefficients. The original estimates of around CDb=0.4 could be correct for species, such as pelicans and large herons, that also have prominent heads. We see no evidence for any progressive reduction of body drag coefficient in the Reynolds number range covered by our experiments, that is 21 600&shy;215 000 on the basis of body cross-sectional diameter.

scholarly journals STUDY OF VITAMIN D DEFICIENCY IN PATIENTS WITH DEPRESSIONWHETHER IT IS THE REASON FOR THE HIGH RATES OF SOMATIC PRESENTATION OF DEPRESSION.

2021 ◽  
pp. 1-3
Author(s):  
Debasish Sanyal ◽  
Priya Mukherjee
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Somatic Symptom ◽  
The Body ◽  
Control Group ◽  
Cross Sectional ◽  
Study Materials ◽  
The Mean ◽  
Low Levels ◽  
The Difference

Background: Several studies have shown a relationship between depression and low levels of Vitamin D in the body. At the same time, somatisation is found to be a significant complaint in many patients of depression. Whether somatisation has any relationship with the low levels of Vitamin D, needs further research. Aims: To compare the prevalence of Vitamin D deficiency between depressed and non depressed subjects, and see if somatic presentation of depression has any correlate with Vitamin D deficiency. Design: Observational, cross-sectional, hospital- based study. Materials & Methods: The study was conducted in the Department of Psychiatry, in a Private Hospital. Diagnosed MDD patients consenting to participate in the study, & sex matched controls, comprising of close family members of patients were selected. Detailed assessment of depression symptomatology was done. Assessment of somatization was done using Bradford Somatic Inventory. Blood samples were collected for routine tests and Vitamin D (total) estimation. Results: In the group of MDD patients, the mean age of females is 52 years, & mean age of males is 50 years. In the MDD group, the mean Vitamin D level is 17.12; in the control group, the mean Vitamin D level is 22.19. The difference is statistically significant. Among MDD patients, 70% had deficiency of Vitamin D. In the Severe somatic symptom category, 68.3% had deficiency of Vitamin D; in the Mild somatic symptom category, 66.7% had deficiency of Vitamin D. The difference is not statistically significant. Conclusion: Depression patients have significantly higher proportion of Vitamin D deficiency cases. Depressed patients with higher number of somatic symptoms have lower vitamin D level, but the difference is not significant.

scholarly journals Comparative morphometry of the brainstem of the male and female Helmeted Guinea Fowl (Numida meleagris)

2018 ◽  
Vol 51 (3) ◽  
pp. 121-124
Author(s):  
Mohammed Adam ◽  
Barth Izuchukwu Onyeanusi ◽  
Joseph Olusegun Hambolu ◽  
Suleiman Folorunsho Ambali ◽  
Chikera Samuel Ibe
Keyword(s):  
Medulla Oblongata ◽  
Guinea Fowl ◽  
The Body ◽  
Base Line ◽  
Male And Female ◽  
Numida Meleagris ◽  
Body Weights ◽  
The Mean ◽  
The Difference ◽  
The Brain

Abstract The aim of this study was to obtain base-line morphometric data on the whole brain and brainstem in the adult male and female helmeted guinea fowl (Numida meleagris), and compare the result in the two sexes. Brain samples of seventy adult helmeted guinea fowls, comprising 35 males and 35 females, intended for slaughter, were extracted for the study. The body weights for both male and female helmeted guinea fowls were 1247 ± 5.51 g and 1230 ± 4.85 g, respectively. The mean brain weights were 3.39 ± 0.02 g and 3.47 ± 0.18 g for male and female, respectively, and the difference in the values was not significant (P > 0.05). The lengths of the brain and medulla oblongata, as well as the lengths of the midbrain and mesencephalic tectum, did not differ between the two sexes. Neither the mean weights nor lengths of the pons differed between the two sexes. In conclusion, the results of this study showed that there was no sex dimorphism observed in the morphometry of the midbrain, medulla oblongata and pons in the helmeted guinea fowl.

scholarly journals Metabolic Syndrome: What is the difference between the two definitions IDF and NCEP ATP III in Morocco? Case of the population of Marrakech

2021 ◽  
Vol 319 ◽  
pp. 01072
Author(s):  
Zineb Hannoun ◽  
Meryem Makdad ◽  
Khouloud Harraqui ◽  
Imane Boussenna ◽  
Ikram Kenfaoui ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Body Mass Index ◽  
Healthy Lifestyle ◽  
Blood Parameters ◽  
The Body ◽  
Prevention Strategies ◽  
The Metabolic Syndrome ◽  
The Mean ◽  
Spss Software ◽  
The Difference

The purpose of this study was to determine the frequency of metabolic syndrome according to the two definitions: NCEP-ATP III and IDF 2005 and to analyze their differences in a population in Marrakech, Morocco. The study was carried out at Ibn Zohr hospital in Marrakech. The body mass index (BMI) was calculated to assess the degree of obesity of each subject. The blood parameters were measured by an appropriate biochemistry automaton. The diagnosis of metabolic syndrome was made according to the definitions of NCEP-ATP III and IDF 2005. All statistical analyzes were performed using SPSS software. A total of 300 subjects participated in the study, including 57.3% of women and 42.7% of men, with a sex ratio of 0.74. The mean age of our population was 51.6 ± 13.42 years. According to NCEP-ATP III, 79 of the participants (26.3%) had the metabolic syndrome, with a predominance of women: 60 women (20.0%) and 19 men (6.3%); according to the IDF, 139 or (46.3%) of the participants had MS, in which 31.0% were women and 15.3% were men. Waist circumference and hyperglycemia were the two predominant criteria according to both definitions. The study showed that all criteria were statistically associated with the presence of MS. The metabolic syndrome is common in our population regardless of the definition criteria used. The implementation of prevention strategies and the encouragement of a healthy lifestyle will minimize serious health problems in Marrakech city.

scholarly journals Narrowband UVB versus psoralen – narrowband UVB in cases of chronic plaque type psoriasis: a matched pair study

2016 ◽  
Vol 2 (4) ◽  
pp. 82
Author(s):  
C. Shanmuga Sekar ◽  
L. Sorna Kumar ◽  
Karthika Natarajan ◽  
C. R. Srinivas
Keyword(s):  
Uv Light ◽  
Statistical Significance ◽  
Chronic Inflammatory Disease ◽  
Mean Value ◽  
The Body ◽  
Matched Pair ◽  
Plaque Type ◽  
Narrowband Uvb ◽  
The Mean ◽  
The Difference

<p class="abstract"><strong>Background:</strong> Psoriasis is a chronic inflammatory disease and various therapeutic options are available to treat the condition. The aim was to compare the efficacy of psoralen narrowband UV light (P-NBUVB) to conventional narrowband UVB light (NBUVB) in the treatment of psoriasis.</p><p class="abstract"><strong>Methods:</strong> A total of 17 cases were included in our study. NBUVB was given on one half of the body and P-NBUVB was given on the other half and the response in two characteristic lesions was compared.<strong></strong></p><p class="abstract"><strong>Results:</strong> The total lesional severity scale (TLSS) score of fourteen completed patients at the end of five sittings was 132 (mean- 9.42) for NBUVB and 127 (mean- 9.07) for P-NBUVB. The difference was not statistically significant. At the end of ten treatments the mean value was 5.76 for NBUVB and 4.92 for P-NBUVB.  There was statistical significance at this point. However by the end of our study, after fifteen treatments the mean value for NBUVB and P-NBUVB were 3.0 and 2.76 respectively which were statistically not significant.</p><p><strong>Conclusions:</strong> We conclude that P-NBUVB was as effective as NBUVB in clearing psoriasis and further studies with larger study population is required to prove the efficacy of this treatment modality. </p>

Sign in / Sign up

Export Citation Format

Share Document