scholarly journals DEET as a feeding deterrent

2017 ◽  
Author(s):  
WeiYu Lu ◽  
Justin Hwang ◽  
Fangfang Zeng ◽  
Walter S. Leal
Keyword(s):  
Dimethyl Sulfoxide ◽  
Outer Surface ◽  
Direct Contact ◽  
Feeding Deterrent ◽  
Feeding Time ◽  
Insect Repellent ◽  
Feeding Deterrence ◽  
Spatial Repellent ◽  
The Mean ◽  
Time Spent Feeding

AbstractThe insect repellent N,N-diethyl-3-methylbenzamide (DEET), is a multimodal compound that acts as a spatial repellent as well as an irritant (contact repellent), thus being perceived by the insect’s olfactory and gustatory systems as an odorant and a tastant, respectively. Soon after DEET was developed, almost 6 decades ago, it was reported that it reduced mosquito feeding on blood mixed with this repellent. It is now known that the mosquito proboscis senses contact repellents with the tips (labella) of the labium, which remain in direct contact with the outer layers of the skin, while the stylets, including the feeding deterrent sensor (labrum), penetrate the skin. We designed a behavioral assay that allowed us to tease apart contact repellency from feeding deterrence. First, we demonstrate here that when DEET was mixed with blood and covered by Parafilm® layers, it did not leak to the outer surface. In our assays, the mean number of landings and duration of contacts with surfaces covering blood mixed with DEET or blood plus solvent (dimethyl sulfoxide) did not differ significantly. The feeding times, however, were significantly different. When blood was mixed either with 0.1 or 1% DEET, female southern house mosquitoes spent significantly less time feeding than the time spent feeding on blood mixed only with the solvent. By contrast, there were no significant differences in the mean times of feeding on blood containing 1% picaridin and blood plus solvent. Like DEET, the contact repellent and insecticide, permethrin, caused a significant reduction in feeding time. We, therefore, concluded, that in this context, DEET and permethrin act as feeding deterrents.

Some aspects of the life cycle of the tick ixodes pilosus under laboratory conditions

1991 ◽  
Vol 62 (1) ◽  
pp. 15-16 ◽  
Author(s):  
Y. Rechav
Keyword(s):  
Life Cycle ◽  
Egg Production ◽  
Feeding Time ◽  
Laboratory Conditions ◽  
Preoviposition Period ◽  
The Mean

Some aspects of the life cycle of the tick Ixodes pilosus were studied under laboratory conditions. The preoviposition period was 7,2 ± 0,6 d. Maximum egg production was on Day 4 after oviposition commenced, with total egg production of 2 395 ± 128,7 eggs per female. The mean feeding time of larvae was 3,3 ± 0,1 d. The life cycle could not be completed due to the specific requirements of this species.

Investigation of Luminous/Nonluminous Radiation in a Vortex Engine

2007 ◽  
Author(s):  
M. H. Saidi ◽  
M. Kargar ◽  
A. Ghafourian
Keyword(s):  
Heat Transfer ◽  
Outer Surface ◽  
Direct Contact ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Axial Flow ◽  
Chamber Wall ◽  
Radiation Heat ◽  
Insulating Material ◽  
Quartz Window

Investigation of radiation heat transfer In vortex engine is an important and new phenomenon in combustion for scientists and combustion researchers. In this research some parts of the combustion chamber wall are insulated using Blanket as a high insulating material. The rate of radiative heat transfer to the chamber wall is calculated using temperature difference between inner and outer surface of chamber. In the experiments this parts are protected from direct contact with hot combustion media using quartz window. The luminous radiative transfer per volume of chamber and also volume of flame in a vortex engine are compared with that in a similar axial flow type engine. A detector sensitive to emission from C2* excited radically is utilized for the measurement of chemiluminescence emission at the centerline of chamber along all axial positions. The filtered photographs of flame are used to compare total C2* emission from flame.

scholarly journals Demographic variables associated with Covid-19 mortality

2020 ◽  
Vol 9 (4) ◽  
Author(s):  
José Manuel Madrazo Cabo ◽  
Nuvia Adriana Monter Valera ◽  
Edith Jocelyn Hernández Sánchez ◽  
Mariola Ruiz Sánchez ◽  
Gabriela Sánchez Machorro ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Gross Domestic Product ◽  
Chronic Conditions ◽  
Direct Contact ◽  
Protein S ◽  
Demographic Variables ◽  
Domestic Product ◽  
Population Pyramid ◽  
Pyramid Structure ◽  
The Mean

Objectives: Covid-19 is a betacoronavirus that was initially transmitted to humans from an animal host. It enters the cell by binding its protein S with angiotensin-converted enzyme receptors. It is transmitted through direct contact and respiratory drops. The most affected population so far are older adults and people with chronic conditions. The objective of this research is to analyze the possible association between the structure of the population pyramid, the Gross Domestic Product, the type of isolation and screening used to detect Covid-19 in the countries with the highest and lowest mortality from this disease.Design and Methods: Some variables take part in the Covid-19 mortality worldwide, such as the population structure, expressed in the population pyramid by country, the type of isolation adopted in each nation, the Gross Domestic Product (GDP) as well as the type of screening that is implemented in the different countries analyzed.Results: After analyzing the mean difference in the countries with a regressive and progressive population pyramid, an association was identified between the regressive population pyramid structure and the higher mortality rate (p<0.001).Conclusions: The countries with a progressive population pyramid are the most benefited by making their population more screened since the mortality rate decreases significantly compared to the countries with less attribution (p<0.036).

scholarly journals New Case Detection by Cascade Testing in Familial Hypercholesterolemia

2019 ◽  
Vol 12 (11) ◽  
Author(s):  
Christopher Lee ◽  
Miriannie Rivera-Valerio ◽  
Hana Bangash ◽  
Larry Prokop ◽  
Iftikhar J. Kullo
Keyword(s):  
Genetic Testing ◽  
Familial Hypercholesterolemia ◽  
Direct Contact ◽  
Index Case ◽  
The United States ◽  
Case Detection ◽  
Sample Collection ◽  
Cascade Testing ◽  
First Degree Relatives ◽  
The Mean

Background: The prevalence of familial hypercholesterolemia is 1 in 250, but <10% of patients are diagnosed. Cascade testing enables early detection of cases through systematic family tracing. Establishment of familial hypercholesterolemia cascade testing programs in the US could be informed by approaches used elsewhere. Methods: We conducted a systematic review of published studies in the English language of cascade testing for familial hypercholesterolemia, which reported the number of index cases and number of relatives tested and specified methods of contacting relatives and testing modalities methods utilized. For each study, we calculated yield (proportion of relatives who test positive) and new cases per index case, to facilitate comparison. Results: We identified 10 studies from the literature that met inclusion criteria; the mean number of probands and relatives per study was 242 and 826, respectively. The average yield was 44.76% with a range of 30% to 60.5%, and the mean new cases per index case was 1.65 with a range of 0.22 to 8.0. New cases per index case tended to be greater in studies that used direct contact versus indirect contact (2.06 versus 0.86), tested beyond first-degree relatives versus only first-degree relatives (3.65 versus 0.80), used active sample collection versus collection at clinic (4.11 versus 1.06), and utilized genetic testing versus biochemical testing (2.47 versus 0.42). Conclusions: New case detection in familial hypercholesterolemia cascade testing programs tended to be higher with direct contact of relatives, testing beyond first-degree relatives, in-home–based sample collection, and genetic testing. These findings should be helpful for establishing cascade testing programs in the United States.

Caractéristiques de la coquille des oeufs chez la souche hybride (ovipare × vivipare) du lézard Lacerta vivipara

1992 ◽  
Vol 70 (11) ◽  
pp. 2242-2246 ◽  
Author(s):  
Benoît Heulin ◽  
Maria Jesus Arrayago ◽  
Antonio Bea ◽  
Florentino Brana
Keyword(s):  
Outer Surface ◽  
Experimental Studies ◽  
Dry Mass ◽  
Eggshell Membrane ◽  
Hybrid Strain ◽  
The Mean ◽  
Lacerta Vivipara

The lizard Lacerta vivipara has both oviparous and viviparous populations. Experimental crossbreedings (oviparous strain × viviparous strain) in the laboratory have previously allowed us to obtain a hybrid strain. Hybrids have also laid eggs in the laboratory. The aim of the present study was to determine the eggshell characteristics of the hybrid and to compare them with the characteristics previously studied in the oviparous and viviparous strains. The mean thickness of the eggshell is 21 μm for the hybrid, 40 μm for oviparous eggshell, and 9 μm for the viviparous eggshell membrane. Mean dry mass of the eggshell is 3 mg for hybrids, 5 mg for the oviparous strain, and 0.6 mg for the viviparous strain. Ash mass of the eggshell is 0.79 mg for hybrids, 1.05 mg for the oviparous strain, and 0.22 mg for the viviparous strain. Fibrils were observed in both oviparous and hybrids' eggshells and in the viviparous eggshell membrane. The outer surface of the hybrids' eggs presents both places with a calcareous layer (61%) and places where fibrils are not covered with a calcareous layer (39%). These incompletely calcified eggshells are intermediate between the oviparous eggshells (complete calcareous layer) and the regressed eggshell membrane (fibrils with minor traces of calcite) observed during the gestation of the viviparous lizards. This situation is of considerable interest for further experimental studies dealing with physiological and genetic aspects of the evolution of viviparity.

scholarly journals Crystal structure of 6-amino-4-(3-bromo-4-methoxyphenyl)-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile dimethyl sulfoxide monosolvate

2015 ◽  
Vol 71 (7) ◽  
pp. o453-o454 ◽  
Author(s):  
Sammer Yousuf ◽  
Huma Bano ◽  
Munira Taj Muhammad ◽  
Khalid Mohammed Khan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Benzene Ring ◽  
Dihedral Angle ◽  
Pyrazole Ring ◽  
Ring System ◽  
The Mean

In the pyrazole molecule of the title solvate, C15H13BrN4O2·C2H6OS, the dihedral angle between the benzene ring and the mean plane of the dihydropyrano[2,3-c]pyrazole ring system [r.m.s deviation = 0.031 (2) Å] is 86.71 (14)°. In the crystal, the pyrazole molecules are linked by N—H...N hydrogen bonds, forming a layer parallel to (10-1). The pyrazole and dimethyl sulfoxide molecules are connected by an N—H...O hydrogen bond.

The inner-salt zwitterion, the dihydrochloride dihydrate and the dimethyl sulfoxide disolvate of 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid

2012 ◽  
Vol 68 (11) ◽  
pp. o431-o435 ◽  
Author(s):  
Yi Wang ◽  
Helen Stoeckli-Evans
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dicarboxylic Acid ◽  
Dimethyl Sulfoxide ◽  
Three Dimensional ◽  
Boat Conformation ◽  
Pyrazine Ring ◽  
Supramolecular Architectures ◽  
Carboxylate Groups ◽  
The Mean

In the inner-salt zwitterion of 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid, (I), namely 5-carboxy-3-(pyridin-1-ium-2-yl)-6-(pyridin-2-yl)pyrazine-2-carboxylate, [C16H10N4O4, (Ia)], the pyrazine ring has a twist–boat conformation. The opposing pyridine and pyridinium rings are almost perpendicular to one another, with a dihedral angle of 80.24 (18)°, and are inclined to the pyrazine mean plane by 36.83 (17) and 43.74 (17)°, respectively. The carboxy and carboxylate groups are inclined to the mean plane of the pyrazine ring by 43.60 (17) and 45.46 (17)°, respectively. In the crystal structure, the molecules are linkedviaN—H...O and O—H...O hydrogen bonds, leading to the formation of double-stranded chains propagating in the [010] direction. On treating (Ia) with aqueous 1 MHCl, the diprotonated dihydrate form 2,2′-(3,6-dicarboxypyrazine-2,5-diyl)bis(pyridin-1-ium) dichloride dihydrate [C16H12N4O42+·2Cl−·2H2O, (Ib)] was obtained. The cation lies about an inversion centre. The pyridinium rings and carboxy groups are inclined to the planar pyrazine ring by 55.53 (9) and 19.8 (2)°, respectively. In the crystal structure, the molecules are involved in N—H...Cl, O—H...Owaterand Owater—H...Cl hydrogen bonds, leading to the formation of chains propagating in the [010] direction. When (Ia) was recrystallized from dimethyl sulfoxide (DMSO), the DMSO disolvate 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid dimethyl sulfoxide disolvate [C16H10N4O4·2C2H6OS, (Ic)] of (I) was obtained. Here, the molecule of (I) lies about an inversion centre and the pyridine rings are inclined to the planar pyrazine ring by only 23.59 (12)°. However, the carboxy groups are inclined to the pyrazine ring by 69.0 (3)°. In the crystal structure, the carboxy groups are linked to the DMSO molecules by O—H...O hydrogen bonds. In all three crystal structures, the presence of nonclassical hydrogen bonds gives rise to the formation of three-dimensional supramolecular architectures.

scholarly journals Variation in energy intake of female chimpanzees: comparing estimates based on feeding time versus energy ingestion rates

2016 ◽  
Author(s):  
Moreen Uwimbabazi ◽  
Richard W Wrangham ◽  
Zarin P Machanda ◽  
Nancy L Conklin-Brittain ◽  
Jessica M Rothman ◽  
...  
Keyword(s):  
Energy Intake ◽  
Ingestion Rate ◽  
Average Energy ◽  
Seasonal Fluctuation ◽  
Feeding Time ◽  
Feeding Rates ◽  
Ingestion Rates ◽  
Young Leaves ◽  
The Mean ◽  
Nutritional Studies

Different food items can provide calories at different rates, yet nutritional studies of primates are generally based on the proportion of time spent eating different foods. Accordingly, estimates of energy intake are potentially wrong. To assess the importance of this problem we observed 15 female chimpanzees from the Kanyawara chimpanzee community in Kibale National Park, Uganda for 15 months. Feeding rates were recorded and nutritional analyses assembled for 90 food types. Across all foods the mean estimated rate of energy ingestion was 8.8±7.6 Kcals/min. Energy ingestion rates varied among food types (F8,82,=2.24, p<0.05), being higher for ripe fruits (12.2±8.7Kcals/min) than for young leaves (7.8±7.9Kcals/min), piths (6.0±5.2Kcals/min) or seeds (2.8±1.9Kcals/min). Energy ingestion rates estimated assuming high %NDF fermentation (54.3%) were significantly higher than the rates at zero (0%) fermentation (t=6.14, p<0.01). At 54.3% NDF fermentation, estimated energy ingestion rate rose by 20.5% for ripe fruits (9.7 to 12.2 Kcals/min), and by 39.7% for young leaves (4.7 to 7.8Kcals/min). Chimpanzees spent a mean of 304±80 minutes feeding daily, indicating that daily energy intake averaged to 3029 ±1198Kcal. When chimpanzees spent >60% of feeding time on ripe fruits (N=79 days), the average energy intake (3367Kcal) was significantly higher than when they spent >60% of feeding time on herbaceous vegetation (2409Kcal, N=37 days) (F1,114=12.68, p<0.01). Our results highlight the value of using feeding rates to understand chimpanzee nutrition, and suggest that seasonal fluctuation in nutrient intake is more pronounced than indicated by variation in feeding time.

scholarly journals Effect of Oxytocin on the Body Weight of Male Rabbits

2021 ◽  
Vol 36 (4) ◽  
pp. 263-272
Author(s):  
Areej A. Mohammed ◽  
Aisha F. Bonaama ◽  
Souad A. M. Moftah ◽  
Ameerah T. Ramadhan ◽  
Abdulsalam M. A. Bolhaj ◽  
...  
Keyword(s):  
Dose Group ◽  
The Body ◽  
Control Group ◽  
High Dose ◽  
Significant Difference ◽  
The Mean ◽  
Time Spent Feeding ◽  
Mean Time ◽  
Different Doses ◽  
Food Consumed

This study was carried out to investigate the effect of two different doses of oxytocin on weight. Adult male rabbits (15) were weighed and provided with food twice daily for 3 weeks to determine the amount of food consumed daily and the time spent feeding by each rabbit.  After 3 weeks the rabbits were weighed and divided randomly into 3groups: the control group, the low dose group, and the high dose group. The animals were injected daily for 3 weeks. During that time the amount of food consumed and the time spent feeding in both periods were determined. After the end of the treatment period the rabbits were weighed, and sacrificed. The results of this study showed that before treatment the rabbits consumed more food in the evening period than they did in the afternoon period. The mean time spent feeding in the evening period was slightly higher than that spent in the afternoon period; however, this difference was not statistically significant. After treatment, there was still significant difference between the means of the consumed food in the afternoon and the evening period for the control group. The mean amounts of food consumed in both periods by the treated groups were slightly reduced, but this reduction was not statistically significant. Furthermore, the mean time spent feeding in the evening period was slightly higher than that of the afternoon period for the 3 groups; however, these differences were not significant. The mean weight of the control group was slightly increased after treatment with the hormone; and the mean weights of the treated groups were slightly reduced after treatment. However, changes in body weighs were not statistically significant.

Trophic traits of Grammostola vachoni, a tarantula (Araneae : Theraphosidae) from Argentina

2018 ◽  
Vol 66 (3) ◽  
pp. 228 ◽  
Author(s):  
Leonela Schwerdt ◽  
Gabriel Pompozzi ◽  
Ana Elena de Villalobos ◽  
Fernando Pérez-Miles
Keyword(s):  
Significant Positive Correlation ◽  
Ingestion Rate ◽  
Experimental Period ◽  
Mass Gain ◽  
Feeding Time ◽  
Positive Correlation ◽  
Prey Mass ◽  
Mountain Systems ◽  
The Mean ◽  
Trophic Traits

This is the first study about trophic traits of Grammostola vachoni, a threatened theraphosid spider endemic to the mountain systems of central Argentina. Four prey types were used in experiments: crickets, cockroaches, beetle larvae and adult beetles. Grammostola vachoni was observed to eat at a rate of about once every 11 days, with the mean total number of prey consumed per spider during the experimental period being 2.7. Latency to the first attack was similar for crickets, cockroaches and beetle larvae, but was shorter for adult beetles. Feeding time was significantly longer for crickets and beetle larvae. Mass gain was significantly different among prey types. Feeding effectiveness and ingestion rate were significantly higher for crickets. A significant positive correlation for feeding effectiveness and ingestion rate with prey mass and the initial spider mass was also found.

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