scholarly journals Control of self-motion in dynamic fluids: fish do it differently from bees

2014 ◽  
Vol 10 (5) ◽  
pp. 20140279 ◽  
Author(s):  
Christine Scholtyssek ◽  
Marie Dacke ◽  
Ronald Kröger ◽  
Emily Baird
Keyword(s):  
Motion Control ◽  
Danio Rerio ◽  
Optic Flow ◽  
Bombus Terrestris ◽  
Physical Contact ◽  
Black And White ◽  
The Mean ◽  
Control Flight ◽  
And Control ◽  
Self Motion

To detect and avoid collisions, animals need to perceive and control the distance and the speed with which they are moving relative to obstacles. This is especially challenging for swimming and flying animals that must control movement in a dynamic fluid without reference from physical contact to the ground. Flying animals primarily rely on optic flow to control flight speed and distance to obstacles. Here, we investigate whether swimming animals use similar strategies for self-motion control to flying animals by directly comparing the trajectories of zebrafish ( Danio rerio ) and bumblebees ( Bombus terrestris ) moving through the same experimental tunnel. While moving through the tunnel, black and white patterns produced (i) strong horizontal optic flow cues on both walls, (ii) weak horizontal optic flow cues on both walls and (iii) strong optic flow cues on one wall and weak optic flow cues on the other. We find that the mean speed of zebrafish does not depend on the amount of optic flow perceived from the walls. We further show that zebrafish, unlike bumblebees, move closer to the wall that provides the strongest visual feedback. This unexpected preference for strong optic flow cues may reflect an adaptation for self-motion control in water or in environments where visibility is limited.

scholarly journals Nocturnal insects use optic flow for flight control

2011 ◽  
Vol 7 (4) ◽  
pp. 499-501 ◽  
Author(s):  
Emily Baird ◽  
Eva Kreiss ◽  
William Wcislo ◽  
Eric Warrant ◽  
Marie Dacke
Keyword(s):  
Flight Control ◽  
Optic Flow ◽  
Visual Information ◽  
Visual Cues ◽  
Bombus Terrestris ◽  
Flight Tunnel ◽  
Cluttered Environments ◽  
Flying Insects ◽  
Dim Light ◽  
Control Flight

To avoid collisions when navigating through cluttered environments, flying insects must control their flight so that their sensory systems have time to detect obstacles and avoid them. To do this, day-active insects rely primarily on the pattern of apparent motion generated on the retina during flight (optic flow). However, many flying insects are active at night, when obtaining reliable visual information for flight control presents much more of a challenge. To assess whether nocturnal flying insects also rely on optic flow cues to control flight in dim light, we recorded flights of the nocturnal neotropical sweat bee, Megalopta genalis , flying along an experimental tunnel when: (i) the visual texture on each wall generated strong horizontal (front-to-back) optic flow cues, (ii) the texture on only one wall generated these cues, and (iii) horizontal optic flow cues were removed from both walls. We find that Megalopta increase their groundspeed when horizontal motion cues in the tunnel are reduced (conditions (ii) and (iii)). However, differences in the amount of horizontal optic flow on each wall of the tunnel (condition (ii)) do not affect the centred position of the bee within the flight tunnel. To better understand the behavioural response of Megalopta , we repeated the experiments on day-active bumble-bees ( Bombus terrestris ). Overall, our findings demonstrate that despite the limitations imposed by dim light, Megalopta —like their day-active relatives—rely heavily on vision to control flight, but that they use visual cues in a different manner from diurnal insects.

Prothrombin Time Standardization: Report of the Expert Panel on Oral Anticoagulant Control

1979 ◽  
Vol 42 (04) ◽  
pp. 1073-1114 ◽  
Keyword(s):  
Prothrombin Time ◽  
Expert Panel ◽  
The Other ◽  
Rabbit Brain ◽  
Calibration Constant ◽  
Freeze Dried ◽  
The Mean ◽  
Point Of Intersection ◽  
And Control ◽  
Standardization Report

SummaryIn collaborative experiments in 199 laboratories, nine commercial thromboplastins, four thromboplastins held by the National Institute for Biological Standards and Control (NIBS & C), London and the British Comparative Thromboplastin were tested on fresh normal and coumarin plasmas, and on three series of freeze-dried plasmas. One of these was made from coumarin plasmas and the other two were prepared from normal plasmas; in each series, one plasma was normal and the other two represented different degrees of coumarin defect.Each thromboplastin was calibrated against NIBS&C rabbit brain 70/178, from the slope of the line joining the origin to the point of intersection of the mean ratios of coumarin/normal prothrombin times when the ratios obtained with the two thromboplastins on the same fresh plasmas were plotted against each other. From previous evidence, the slopes were calculated which would have been obtained against the NIBS&C “research standard” thromboplastin 67/40, and termed the “calibration constant” of each thromboplastin. Values obtained from the freeze-dried coumarin plasmas gave generally similar results to those from fresh plasmas for all thromboplastins, whereas values from the artificial plasmas agreed with those from fresh plasmas only when similar thromboplastins were being compared.Taking into account the slopes of the calibration lines and the variation between laboratories, precision in obtaining a patient’s prothrombin time was similar for all thromboplastins.

CHROMATOGRAPHY OF THE 17-KETOGENIC STEROIDS IN THE DIAGNOSIS AND CONTROL OF CONGENITAL ADRENAL HYPERPLASIA

1960 ◽  
Vol XXXIII (II) ◽  
pp. 230-250 ◽  
Author(s):  
Eileen E. Hill
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
List Type ◽  
Adrenal Hyperplasia ◽  
Normal Children ◽  
Paediatric Practice ◽  
The Mean ◽  
Cortisone Therapy ◽  
And Control ◽  
Clinical Problems ◽  
Stimulation Of

ABSTRACT A method for the fractionation of the urinary 17-ketogenic steroids with no oxygen grouping at C11 and those oxygenated at C11, is applied to the clinical problems of congenital adrenal hyperplasia. In normal children the mean ratio of the non-oxygenated to oxygenated steroids is 0.24. In childrern with congenital adrenal hyperplasia the ratio is 2.3. The reason for this difference in ratio is discussed. The changes in ratio found under stimulation of the adrenal gland with exogenous or endogenous corticotrophin and the suppression with cortisone therapy are studied. This test can be applied to isolated samples of urine, a major advantage in paediatric practice, and can be carried out in routine laboratories. It is found to be reliable in the diagnosis and sensitive in the control of congenital adrenal hyperplasia.

IOP Lowering Effects of Ocimum basilicum Seed Extract in Two Rabbit Models of Ocular Hypertension

2019 ◽  
Vol 4 (1) ◽  
pp. 39
Author(s):  
Renu Agarwal ◽  
SK Gupta ◽  
Sushma Srivastava ◽  
Rohit Saxena
Keyword(s):  
Ocular Hypertension ◽  
Antioxidant Properties ◽  
Ocimum Basilicum ◽  
Seed Extract ◽  
Water Loading ◽  
Antiglaucoma Medication ◽  
Lowering Effect ◽  
Significant Difference ◽  
The Mean ◽  
And Control

Introduction: Ocimum basilicum (OB), a herb known for its antihypertensive, anticholinesterase and antioxidant properties was investigated for possible intraocular pressure (IOP) lowering effects in rabbits with ocular hypertension (OHT). Methods: The IOP lowering effect of a single drop of OB extract (OBE) was evaluated in oculonormotensive rabbits using three concentrations (0.25, 0.5 and 1% w/v). The concentration showing maximum IOP reduction was further evaluated in rabbits with water-loading and steroid-induced OHT. Results: IOP lowering effect of OBE 0.5% in oculonormotensive rabbit eyes was significantly greater compared to OBE 0.25% (p<0.05) but was comparable (p>0.05) to OBE 1%. Therefore, 0.5% concentration was selected for further evaluation. Pretreatment with OBE (0.5%) caused significantly lower increase in IOP after water loading amounting to 23.39% above baseline as compared to 54.00% in control eye, 15 minutes post water loading. At 60 minutes, post water loading, mean IOP rise was 95.12% and 63.58% in control and test eyes, respectively. Significant difference between the mean IOP of two eyes persisted during the 2nd hr. In rabbits with steroid induced OHT, OBE 0.5% produced a mean IOP reduction of 24.73% at the end of first hr and the mean peak IOP reduction of 31.63% was observed at the end of 2 hr. A significant difference between the IOP of test and control eyes persisted from 1 to 6 hr. Conclusions: Ocimum basilicum seed extract showed significant IOP lowering effect in rabbits with water loading and steroid induced OHT, however, its utility as an effective antiglaucoma medication needs further investigations.

Mantle Of The Expert Strategy Effectiveness In The Development Of Creative Thinking

2019 ◽  
Author(s):  
Ibrahim Arman
Keyword(s):  
Creative Thinking ◽  
Role Playing ◽  
Thinking Skills ◽  
Measurement Unit ◽  
Quasi Experimental ◽  
Males And Females ◽  
The Mean ◽  
Girls School ◽  
And Control ◽  
Experimental Group

<p>This study aimed at investigating the Effectiveness of Mantle of the Expert in creative thinking Skills among the 7<sup>th</sup> Graders. The study conducted on a sample of 7<sup>th</sup> Graders at Kober Secondary Boys School and Upper Kober Elementary Girls School. The study sample consisted of (100) students split into two groups (experimental and control). The researcher adopting the Torrance test for creative thinking the verbal image "A" by examining the tests used in the Ristow study (1988), Edwards and Baldov (1987) study, and designing a teacher book for the (engineering and measurement) unit according to the integration between the strategies of the mantle of the expert and role playing.</p> <p>This study adopted quasi-experimental design. It included two groups (experimental and controlled) in two branches (males and females) for each group. The controlled group was taught by using the traditional method whereas the experimental group by the mantle of the expert. The data analyzed using (ANCOVA) test to measure the differences in the development of creative thinking between the control and experimental groups.</p> <p>The Conclusions showed that there are statistically significant differences in the mean scores of the creative thinking test due to the way, gender and interaction between them.</p> <p>Based on the Conclusions of the study, the researcher recommends the need to use the mantles of the expert in the teaching of mathematics.</p>

Investigation of the Association Between Carotid Artery Intima-Media Thickness (IMT) and Cardiac Risk Factors in Patients with Systemic Lupus Erythematosus

2020 ◽  
Vol 16 (2) ◽  
pp. 125-133
Author(s):  
Zahra Rezaieyazdi ◽  
Sima Sedighi ◽  
Masoumeh Salari ◽  
Mohammadreza H. Fard ◽  
Mahmoud R. Azarpazhooh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Insulin Resistance ◽  
Lupus Erythematosus ◽  
Serum Insulin ◽  
Venous Blood ◽  
Test Group ◽  
Control Groups ◽  
Significant Difference ◽  
The Mean ◽  
And Control

Background: The relationship between SLE and traditional risk factors for cardiovascular events was evaluated. Methods: The data regarding sixty patients with SLE and 30 healthy controls (age and sex matched) were gathered using SLEDAI forms. Venous blood (10mL) from all the participants was examined for hs-CRP, homocysteine, VCAM1, CBC, anti-DNA antibody, C3, C4, low-density lipoprotein (LDL), cholesterol, FBS and triglyceride. : The IMT of carotid arteries was determined bilaterally by ultrasound. Other measurements included insulin levels via Elisa (Linco/Millipore Corp) and the HOMA-IR index for insulin resistance. Results: The mean age (in years) in the test and control groups was 28.8±10.3 (18-52) and 33.8±9.13 (18-48), respectively. Results: The mean age (in years) in the test and control groups was 28.8±10.3 (18-52) and 33.8±9.13 (18-48), respectively. : The average IMT in the test group was directly related to serum levels of VCAM1 (p<0.001), homocysteine (p<0.001), cholesterol (p<0.009), LDL (p<0.001), TG (p<0.001), and FPG (p=0.004). The association between other risk factors, insulin resistance, carotid IMT and SLEDAI, was nonexistent. Mean insulin and insulin resistance levels in all the participants were 0.43±2.06 µU/mL and 0.09±0.44, respectively. There was no significant difference between the test and control groups regarding serum insulin and insulin resistance levels (p=0.42 and p=0.9, respectively). None of the risk factors, such as hsCRP, VCAM1, or homocysteine, were shown to be related to insulin resistance (p=0.6, p=0.6, p=0.09, respectively). Conclusion:: Our findings did not show an increase in the prevalence of atherosclerosis in patients with SLE. There was no association between IMT and insulin resistance. However, the former was associated with FPG, total cholesterol, LDL, TG, homocystein and VCAM1.

scholarly journals Postoperative analgesia effects of sulfentanyl plus dexmedetomidine in patients received VATS

Pteridines ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 55-60
Author(s):  
Haoyu Jiang ◽  
Ying Zheng ◽  
Chang Liu ◽  
Ying Bao
Keyword(s):  
Statistical Difference ◽  
Control Group ◽  
Control Groups ◽  
Significant Statistical Difference ◽  
Post Surgery ◽  
Intravenous Analgesia ◽  
The Mean ◽  
Nsclc Patients ◽  
And Control ◽  
Time Point

AbstractBackground To evaluate sulfentanyl combined with dexmedetomidine hydrochloride on postoperative analgesia in patients who received video-assisted thoracic surgery (VATS) and its effects on serum norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), and prostaglandin (PGE2).Material and Methods Ninety-nine non-small cell lung cancer (NSCLC) patients who received VATS were included in the study. All the patients received intravenous inhalation compound anesthesia. Of the 99 cases, 49 subjects (control group) received sulfentanyl for patient controlled intravenous analgesia (PICA) and other 50 cases (experiment group) received sulfentanyl combined with dexmedetomidine hydrochloride for PICA after operation of VATS. The analgesic effects of the two groups were evaluated according to Visual Analogue Scales (VAS) and the Bruggrmann Comfort Scale (BCS). The serum pain mediator of NE, DA, 5-HT, and PGE2 were examined and compared between the two groups in the first 24 h post-surgery.Results The VAS scores for the experiment group were significant lower than that of control group on the time points of 8, 16, and 24 h post-surgery (pall<0.05), and the BCS scores of the experiment group in the time points of 8, 16, and 24 h were significantly higher than that of controls (p<0.05). However, the VAS and BCS scores were not statistical differently in the time point of 1, 2, and 4 h post-surgery (pall>0.05). The mean sulfentanyl dosage was 63.01 ± 5.14 μg and 67.12 ± 6.91 μg for the experiment and control groups respectively with significant statistical difference (p<0.05). The mean analgesic pump pressing times were 4.30 ± 1.31 and 5.31 ± 1.46 for experiment and control groups respectively with significant statistical difference (p<0.05). The serum NE, DA, 5-HT, and PGE2 levels were significantly lower in the experimental group compared to that of control group in the time point of 12 h post-surgery (pall<0.05). The side effects of nausea, vomiting, delirium, rash, and hypotension atrial fibrillation were not statistically different between the two groups (pall>0.05).Conclusion Patient controlled intravenous analgesia of sulfentanyl combined with dexmedetomidine hydrochloride was effective in reducing the VAS score and serum pain mediators in NSCLC patients who received VAST.

scholarly journals Hepatic steatosis: a risk factor for increased COVID-19 prevalence and severity—a computed tomography study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asmaa Ali ◽  
Mona Hasan ◽  
Shaimaa Hamed ◽  
Amir Elhamy
Keyword(s):  
Hepatic Steatosis ◽  
Severe Disease ◽  
Severe Pneumonia ◽  
Liver Disorder ◽  
Control Group ◽  
Case Group ◽  
World Population ◽  
Positive Class ◽  
The Mean ◽  
And Control

Abstract Background Around 25% of the world population was affected by the metabolic-related fatty liver disorder. Hepatic steatosis is frequently observed in conjunction with hypertension, obesity comorbidities, and diabetes. We evaluate the hepatic steatosis frequency found in chest CT exams of COVID-19-positive cases compared to non-infected controls and evaluate the related increased prevalence and severity of COVID. Results Our research includes 355 subjects, 158 with positive PCR for COVID-19 (case group) and 197 with negative PCR and negative CT chest (control group). The mean age in the positive group was 50.6 ± 16 years, and in the control, it was 41.3 ± 16 years (p < 0.001). Our study consists of 321 men (90.5%) and 34 women (9.5%). The number of males in both cases and control groups was greater. In the case group, 93% men vs. 6.9% women, while in controls, 88.3% men vs.11.6% women, p < 0.001. CT revealed normal results in 55.5% of individuals (i.e., CORADs 1) and abnormal findings in 45.5% of participants (i.e., CORADs 2–5). In abnormal scan, CO-RADs 2 was 13.92%, while CO-RADs 3–4 were 20.89% of cases. CO-RADs 5 comprised 65.19% of all cases. Approximately 42.6% of cases had severe disease (CT score ≥ 20), all of them were CO-RADs 5. The PCR-positive class had a greater prevalence of hepatic steatosis than controls (28.5% vs.12.2%, p < 0.001). CO-RADs 2 represented 11.1%, CO-RADs 3–4 represented 15.6%, and CO-RADs 5 represented 73.3% in the hepatic steatosis cases. The mean hepatic attenuation value in the case group was 46.79 ± 12.68 and in the control group 53.34 ± 10.28 (p < 0.001). When comparing patients with a higher severity score (CT score ≥ 20) to those with non-severe pneumonia, it was discovered that hepatic steatosis is more prevalent (73.2% vs. 26.8%). Conclusions Steatosis was shown to be substantially more prevalent in COVID-19-positive individuals. There is a relation among metabolic syndrome, steatosis of the liver, and obesity, as well as the COVID-19 severity.

The effect of face-to-face and virtual prenatal care training of spouses on the pregnancy experience and fear of childbirth of primiparous women: A controlled quasi-experimental study

2021 ◽  
pp. 1357633X2110241
Author(s):  
Zari Doaltabadi ◽  
Leila Amiri-Farahani ◽  
Seyedeh Batool Hasanpoor-Azghady ◽  
Shima Haghani
Keyword(s):  
Prenatal Care ◽  
Fear Of Childbirth ◽  
Virtual Training ◽  
Face To Face ◽  
Significant Difference ◽  
Quasi Experimental ◽  
Care Training ◽  
The Mean ◽  
And Control ◽  
Primiparous Women

Introduction The spouse has a special role in promoting the health of mothers and infants during pregnancy, childbirth, and postpartum. Women's health during pregnancy requires the participation and cooperation of their spouses. Therefore, this study was conducted to determine the effect of face-to-face and virtual prenatal care training of spouses on the pregnancy experience and fear of childbirth of primiparous women. Methods This is a quasi-experimental clinical trial that was conducted on primiparous pregnant women referring to three prenatal clinics in Tehran, Iran. Sampling was done by available method and pregnant women were divided into three groups of face-to-face training ( n = 35), virtual training ( n = 35), and control ( n = 33). The content of training program in the virtual and face-to-face groups was similar and included; nutrition during pregnancy, emotional support, fetal growth and development, advantages and disadvantages of vaginal delivery, planning for delivery, infant care, and danger signs for infants, which were presented in four sessions. The samples in the control group did not receive any training. In the 18th and 20th weeks of pregnancy, the demographic information form, pregnancy experience scale, and version A of the Wijma delivery expectancy/experience questionnaires were completed, and once again in the 37th and 38th weeks of pregnancy, the pregnancy experience scale and version A of the Wijma delivery expectancy/experience questionnaires were completed. Results There was a statistically significant difference in the mean score of pregnancy experience after the intervention between the face-to-face training and control groups ( p = 0.001). There was a statistically significant difference in the mean score of uplifts between the two groups of face-to-face training and control ( p = 0.01), and also between virtual training and control groups ( p = 0.02). There was a statistically significant difference between the two groups of face-to-face training and control in terms of and hassles score after the intervention ( p = 0.04). There was a statistically significant difference between the two groups of face-to-face training and control ( p = 0.02) and also between virtual training and control ( p = 0.04) in terms of the mean score of fear of childbirth after the intervention. Conclusion The results of this study showed that teaching prenatal care to spouses of primiparous women by face-to-face and virtual methods can be a useful intervention in improving the pregnancy experience and reducing the fear of childbirth among primiparous women.

scholarly journals Risk factors of dengue fever in an urban area in Vietnam: a case-control study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Thang Nguyen-Tien ◽  
Duy Cuong Do ◽  
Xuan Luat Le ◽  
Thi Hai Dinh ◽  
Mats Lindeborg ◽  
...  
Keyword(s):  
Risk Factors ◽  
Dengue Fever ◽  
Prevention And Control ◽  
Case Control Study ◽  
Case Control ◽  
Younger Adults ◽  
The Mean ◽  
Dengue Prevention ◽  
And Control ◽  
Control Study

Abstract Background Dengue is a mosquito-borne flavivirus present in many metropolitan cities of tropical countries. Methods During and after the dengue season (September 2018 to January 2019), we conducted a case-control study in order to determine the risk factors for dengue fever in Hanoi city, Vietnam. 98 dengue patients and 99 patients with other acute infections, such as Hepatitis B virus infection, were recruited at Department of Infectious Disease of Bach Mai national hospital in Hanoi. Patients were interviewed using a structured questionnaire covering demographic, housing, environmental factors and knowledge, attitude, and practice on dengue prevention and control. Univariate analysis and multivariable logistic regression were used to determine the risk factors of dengue status. Results The mean score of knowledge items and practice items was only 7.9 out of total 19 points and 3.9 out of total 17 points, respectively. While the mean score of attitude items was 4.8 out of total 6 points. Multivariable logistic regression indicated that older patients had lesser risk of getting dengue infection as compared to younger adults aged 16–30, and patients living in peri-urban districts were less likely to suffer of dengue fever than patients living in central urban districts (OR = 0.31; 95% CI 0.13–0.75). This study could not find any association with occupation, water storage habit, knowledge, attitude, or practice on dengue prevention. Conclusions All patients had a relatively low level of knowledge and practice on dengue prevention and control. However, the attitude of the participants was good. We found that age group and living district were the risk factors correlated with the dengue status. Communication programs on raising dengue awareness should be repeated all year round and target particular groups of adolescents, younger adults, landlords and migrants from other provinces to improve their knowledge and encourage them to implement preventive measures against dengue fever.

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