scholarly journals Repellent activities of dichloromethane extract of Allium sativum (garlic) (Liliaceae) against Hyalomma rufipes (Acari)

2016 ◽  
Vol 87 (1) ◽  
Author(s):  
Felix Nchu ◽  
Solomon R. Magano ◽  
Jacobus N. Eloff
Keyword(s):  
Avoidance Response ◽  
Allium Sativum ◽  
Type A ◽  
Test Solution ◽  
Hard Tick ◽  
Type B ◽  
Repellent Effect ◽  
The Mean ◽  
The Difference ◽  
Hyalomma Rufipes

Dichloromethane (DCM) extract of garlic (Allium sativum Linn.) bulbs was assessed for its repellent effect against the hard tick, Hyalomma rufipes (Acari: Ixodidae) using two tick behavioural bioassays; Type A and Type B repellency bioassays, under laboratory conditions. These bioassays exploit the questing behaviour of H. rufipes, a tick that in nature displays ambush strategy, seeking its host by climbing up on vegetation and attaching to a passing host. One hundred microlitres (100 µL) of the test solution containing DCM extract of garlic bulbs and DCM at concentrations of 0.35%, 0.7% or 1.4% w/v were evaluated. DCM only was used for control. Tick repellency increased significantly (R2 = 0.98) with increasing concentration (40.03% – 86.96%) yielding an EC50 of 0.45% w/v in Type B repellency bioassay. At concentration of 1.4% w/v, the DCM extract of garlic bulbs produced high repellency index of 87% (male ticks) and 87.5% (female ticks) in the Type A repellency bioassay. Only 4% avoidance of male ticks or female ticks was recorded in the Type B repellency bioassay. In the corresponding controls, the mean numbers of non-repelled male or female ticks were 80% and 41 males or 38 females of 50 ticks in the Type A and Type B repellency bioassays, respectively. The variations in the results could be attributed to the difference in tick repellent behaviours that were assessed by the two repellency bioassays; the Type A repellency bioassay assessed repellent effect of garlic extracts without discriminating between deterrence and avoidance whereas the Type B repellency bioassay only assessed avoidance response. Generally, DCM extract of garlic was repellent against H. rufipes, albeit weak tick repellency was obtained in the Type B repellency bioassay. Furthermore, this study established that the tick repellent activity of garlic extracts is predominantly by deterrence.

Elimination of Ammonium Ion from the a-Hydroxyalkyl Radicals of Serine and Threonine in Aqueous Solution and the Difference in the Reaction Mechanism

1985 ◽  
Vol 40 (11-12) ◽  
pp. 785-797 ◽  
Author(s):  
Günter Behrens ◽  
Günther Koltzenburg
Keyword(s):  
Kinetic Data ◽  
Type A ◽  
Ammonium Ion ◽  
Type B ◽  
Ketyl Radical ◽  
Time Resolved ◽  
Hydroxyalkyl Radical ◽  
The Difference ◽  
Hydroxyalkyl Radicals ◽  
Radical Attack

Abstract The zwitterionic radicals HO-ĊH-CH(COO-)NH3+ (4a) and HO-Ċ(CH3)-CH(COO-)NH3+ (4b) are the main species produced upon OH· radical attack in aqueous solutions at pH 3-7 at the amino acids serine, HO-CH2-CH(COO-)NH3+, or threonine, HO-CH(CH3)-CH(COO-)NH3+, respectively. Both radicals undergo elimination of NH4+ ion to form the radicals O=CH-ĊH-COO- (7) or CH3-CO-ĊH-COO- (9) respectively.The pKa of the serine-derived cationic radical HO-ĊH-CH(COOH)NH3+ (3a) (3a ⇄ 4a + H+), was determined by ESR spectroscopy to 2.2 ± 0.1 at 276 K. From kinetic data the pKa(OH) of radical 4a (4a ⇄ O-ĊH-CH(COO-)NH3+ (5a) + H+) was calculated to 7.0. The elimination of NH3 takes place from the ketyl radical 5a (type-B mechanism), the rate constant was calculated from kinetic data to 2.4 × 106 s-1 at 290 K.The half-lives of radicals 4a and 4b were measured by time-resolved conductivity changes upon pulse radiolysis, 170 ± 10 μs for 4a and 26 ± 2 μs for 4b, at 290 K and pH 5.8 .With the threonine derived radicals elimination of NH3 takes place at the stage of the α-hydroxyalkyl radical 4b (type-A mechanism). In this series the pKa of the product radical CH3-CO-ĊH-COOH (8) (8 ⇄ 9 + H+), was determined by ERS spectroscopy to 2.7 ± 0.1. The reasons for the observed mechanistic differences (type-A versus type-B decay) are discussed. As further examples for a type-B decay some preliminary data on the elimination of HF from the radicals CF3-Ċ(OH)-CF3 and CF3-ĊH-OH have been added.

scholarly journals Determination of Inulin in Foods

2000 ◽  
Vol 83 (3) ◽  
pp. 675-678 ◽  
Author(s):  
Breda Simonovska
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Thin Layer ◽  
Degree Of Polymerization ◽  
Test Solution ◽  
Boiling Water Bath ◽  
Before And After ◽  
The Mean ◽  
The Difference

Abstract A method was developed for determining fructan inulin in various foods (yogurts, honey cakes, chocolates). Warm water was applied for extraction of samples, and mono- and dissacharides were determined by a thin-layer chromatographic densitometric method. A portion of the test solution was hydrolyzed 30 min with 1% oxalic acid in a boiling water bath. Fructose was determined in the hydrolysate. The amount of inulin in a sample was calculated as the difference between the amount of fructose in the sample before and after hydrolysis. The fructose from sucrose formed during the hydrolysis was also considered. The mean recovery from yogurt fortified with 4% inulin was 95.5 ± 4.5% (mean ± standard deviation); from honey cakes extract fortified with 10% inulin, 97.3 ± 5.5%; and from chocolate extract fortified with 30% inulin, 98.6 ± 6.6% (6 replicates in all cases). Determination of glucose is not necessary for analyzing fructans with the composition expressed shortened to GFn−1 (G, glucose; F, fructosyl) with the average degree of polymerization 8 ≤ n ≤ 15.

The population of germ cells in immature male rats following irradiation at birth

1966 ◽  
Vol 165 (998) ◽  
pp. 103-135 ◽  
Keyword(s):  
Germ Cells ◽  
Total Population ◽  
Primordial Germ Cells ◽  
Type A ◽  
Male Rats ◽  
Type B ◽  
The Absolute ◽  
The Difference ◽  
Transitional Cells ◽  
Type A Spermatogonia

Male rats were irradiated with 19 r on the day of birth, and killed at intervals ranging from 5 to 18 days. Estimates were made of the absolute and relative numbers of germ cells at different stages of spermatogenesis in 64 irradiated and 61 untreated specimens. In the normal rat, the calculated population of germ cells increased from about 160000 at 5 days to 30 million at 18 days. Only negligible numbers of primordial germ cells (gonocytes and transitional cells) persisted beyond the age of 10 days. Small numbers of spermatogonia type A appeared at 5 days (15000) and their population rose to about 1 million at 12 days, and 2 million at 18 days (7 % of all germ cells). Intermediate spermatogonia first occurred in appreciable numbers (23000 to 55000) at 8 or 9 days, when the population of type-A spermatogonia was 360000. The subsequent rise in the population of intermediate spermatogonia was more rapid than that of type A (4 million at 18 days). Spermatogonia type B and primary spermatocytes appeared at 9 to 10 days, and their numbers rose more steeply still (6.5 and 16 million at 18 days, respectively). Irradiation at birth exerted no rapid effect on the cytological appearance of primordial germ cells. Transformation from gonocytes to transitional cells appeared to proceed normally and the estimated total population of germ cells at 5 days was no smaller than in the controls. Subsequently, however, many of the transitional cells failed to divide: they enlarged to form giant cells, acquired bizarre nuclear outlines, and persisted for unusually long periods. Some degenerated at mitotic prophase or metaphase, while a few seemed to die at interphase, without entering division. The calculated total population of germ cells in irradiated rats rose from 160000 at 5 days to 9.4 million at 18 days. Small numbers of spermatogonia type A, presumably derived from such primordial germ cells as were able to complete mitosis, appeared some 2 to 3 days later than in controls. The number of type-A spermatogonia in 7-day-old irradiated rats was 44000, cf. 215000 in controls; the difference became less pronounced with time, and by the age of 18 days, the population of 1.9 million was comparable to that estimated for the controls. Small numbers of intermediate spermatogonia appeared on the 9th (8000) and 10th day (35000), when the population of type-A spermatogonia was about 110000 and 260000 respectively. By the 18th day, intermediate spermatogonia numbered 2 million. The populations of type-B spermatogonia and primary spermatocytes rose from 11000 to 13000 at 10 days to 1.6 and 3.4 million, respectively, at 18 days. The difference in the absolute and relative numbers of germ cells between normal and irradiated testes widened progressively with advance in the developmental stage of the germ cells. Analysis of the results indicates that in the reduced population of spermatogonia type A after irradiation, the pattern of spermatogonial mitoses is modified so as to favour the formation of more type-A, in preference to intermediate, spermatogonia.

Derivation of correction terms for general quadrature formulae

1969 ◽  
Vol 66 (3) ◽  
pp. 571-586 ◽  
Author(s):  
J. A. Grant
Keyword(s):  
Finite Interval ◽  
Bernoulli Polynomials ◽  
Type A ◽  
Weighted Sum ◽  
Type B ◽  
Quadrature Formulae ◽  
The Difference ◽  
Correction Terms

AbstractIn this paper, it will be shown how it is possible, using Bernoulli polynomials of the first kind, to derive correction terms for any quadrature approximation in the form of a weighted sum over a finite interval. The terms derived will involve either the difference or the sum of derivatives taken at the ends of the range of integration, and they will be described as being of either Type A or Type B respectively. There will also be some discussion of the uses of such terms.

scholarly journals Voltage-Activated Potassium Outward Currents in Two Types of Spider Mechanoreceptor Neurons

1999 ◽  
Vol 81 (6) ◽  
pp. 2937-2944 ◽  
Author(s):  
Shin-Ichi Sekizawa ◽  
Andrew S. French ◽  
Ulli Höger ◽  
Päivi H. Torkkeli
Keyword(s):  
Outward Current ◽  
Type A ◽  
Transient Current ◽  
Resting Potential ◽  
Transient Outward Current ◽  
Type B ◽  
Outward Currents ◽  
The Difference ◽  
Major Factors ◽  
Kinetics Of

Voltage-activated potassium outward currents in two types of spider mechanoreceptor neurons. We studied the properties of voltage-activated outward currents in two types of spider cuticular mechanoreceptor neurons to learn if these currents contribute to the differences in their adaptation properties. Both types of neurons adapt rapidly to sustained stimuli, but type A neurons usually only fire one or two action potentials, whereas type B neurons can fire bursts lasting several hundred milliseconds. We found that both neurons had two outward current components, 1) a transient current that activated rapidly when stimulated from resting potential and inactivated with maintained stimuli and 2) a noninactivating outward current. The transient outward current could be blocked by 5 mM tetraethylammonium chloride, 5 mM 4-aminopyridine, or 100 μM quinidine, but these blockers also reduced the amplitude of the noninactivating outward current. Charybdotoxin or apamin did not have any effect on the outward currents, indicating that Ca2+-activated K+ currents were not present or not inhibited by these toxins. The only significant differences between type A and type B neurons were found in the half-maximal activation ( V 50) values of both currents. The transient current had a V 50 value of 9.6 mV in type A neurons and −13.1 mV in type B neurons, whereas the V 50 values of noninactivating outward currents were −48.9 mV for type A neurons and −56.7 mV for type B neurons. We conclude that, although differences in the activation kinetics of the voltage-activated K+ currents could contribute to the difference in the adaptation behavior of type A and type B neurons, they are not major factors.

scholarly journals What is the role of antineoplastic drug safety in reimbursement decision making?

2018 ◽  
Vol 11 (3) ◽  
pp. 38-42
Author(s):  
A. S. Kolbin ◽  
A. A. Kurylev
Keyword(s):  
Decision Making ◽  
Drug Safety ◽  
Safety Data ◽  
Type A ◽  
Decision Makers ◽  
Final Decision ◽  
Parametric Statistics ◽  
The Mean ◽  
The Difference

Rationale. From 2014 to 2017, the portion of antineoplastic drugs dossiers submitted to reimbursement in Russia has grown from 15% to 28%. This group of drugs is characterized by severe adverse events (Aes). The question whether drug safety is taken into consideration by decision makers is still open.Aim: To evaluate the role of drug safety in making the decision on reimbursement.Materials and methods. The data were taken from the reports of expert committees concerning the dossiers submitted between 2014 and 2016. The year of submission, the international drug name, the total safety score and the final decision of the committee were entered into our database. Parametric and non-parametric statistics were used to calculate the difference between the mean safety scores plotted by years and by inclusion/noninclusion into VeD lists.Results. The mean safety score for all drugs of this group was -4,67 (95% CI from -5,04 to -4,29); for the drugs included into VeD lists it was -4,05 (95% CI from -4,68 to -3,42), that was significantly higher (p = 0,01) compared to the non-included medications (-5,03; 95% CI from -5,49 to -4,58). The mean safety scores year-by-year for the non-included drugs were lower than those for the VeD-included drugs, but the difference reached significance only in 2015 (p = 0,01). The safety scores were mainly based on Aes of type A.Conclusion. our analysis shows that the drug safety data play a role in the decision making on reimbursement and inclusion/noninclusion into VeD lists. Yet the total safety score contributes much less than other criteria in the decision making process. The safety analysis is usually based on Aes of type A, whereas the data on Aes of types C and D are insufficient. 

Type A/B Behavior and Eight Basic Emotions in 1084 Employees

1995 ◽  
Vol 76 (3) ◽  
pp. 1019-1024 ◽  
Author(s):  
Katija Čatipović-Veselica ◽  
Vjekoslav Amidžić ◽  
Dinko Burić ◽  
Vesna Ilakovac ◽  
Damir Kozmar ◽  
...  
Keyword(s):  
Behavior Pattern ◽  
Type A ◽  
Type A Behavior ◽  
Type B ◽  
Basic Emotions ◽  
Type A Behavior Pattern ◽  
Behavioral Counseling ◽  
The Mean ◽  
Emotional Dimensions ◽  
The Relationship

We examined the prevalence of Type A/B behavior and Emotion Profiles in 1084 employees. This report focused on the relationship between Type A behavior and eight basic emotion dimensions. Of the 1084 subjects 710 (65%) scored as Type A and 374 (34.5%) as Type B. The mean Bortner scores for all subjects were 182.8 ( SD = 33.7), scores on emotional dimensions for Incorporation and Reproduction were high, and intensities for Ejection and Destruction were low; mean scores on other emotions were normal. Significant differences between Type A and Type B scores were found on six emotional dimensions. Subjects classified as Type A had ratings lower on trustful, controlled, and timid and higher on aggressive, distrustful, and uncontrolled than did persons classified as Type B. There were no differences between Type A and Type B scores on the emotion dimensions of Reproduction and Deprivation. Our data suggest multiple emotional components may comprise the Type A behavior pattern. This is important for behavioral counseling programs and early preventive efforts which could be aimed at reducing the intensity of Type A behaviors.

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