scholarly journals A New Method to Test Molluscicides against the Philippine Schistosomiasis Snail Vectors

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Darwin C. Gomez ◽  
Neil Anacta
Keyword(s):  
Exposure Period ◽  
Probit Analysis ◽  
Ratio Test ◽  
Confidence Limits ◽  
Oncomelania Hupensis ◽  
Plate Test ◽  
Response Data ◽  
Significant Difference ◽  
Conventional Plate ◽  
Independent Trials

To expedite the discovery of novel molluscicides in the laboratory, this study aimed to evaluate the performance of a new molluscicidal assay. This assay is based on Oncomelania hupensis quadrasi snails and is called miniaturized plate test or mpt. To perform this assay, a 12-well plate, 3 snails per well, and 24-h exposure period were used. The performance of mpt was evaluated using niclosamide and Ardisia plant extract (tagpo extract) as test substances while WHO’s guidelines for a conventional plate test (cpt) served as standard. One cpt and four mpt independent trials were performed for niclosamide and tagpo extract. Probit analysis of dose–response data was run in R to generate lethal concentrations (LC50 and LC90), while lethal ratio test was performed to detect significant difference between paired LC50s (or LC90s). Using niclosamide, the calculated LC50 values were 0.104, 0.127, 0.136, 0.139, and 0.140 g/m2 for cpt, mpt 1, mpt 2, mpt 3, and mpt 4, respectively, while the LC90 values were 0.266, 0.268, 0.244, 0.251, and 0.261 g/m2, using the same sequence, respectively. For tagpo extract, the LC50 values were 1.467, 1.547, 1.659, 1.797, and 1.659 g/m2, for cpt, mpt 1, mpt 2, mpt 3, and mpt 4, respectively, and the LC90s were 2.188, 2.195, 2.501, 2.358, and 2.501 g/m2, respectively. The lethal ratio test revealed that a significant difference exists between the LC50s of cpt and mpt 1 when using niclosamide with a lethal ratio and confidence limits of 0.820 (0.663, 0.977, p<0.05) and another significant difference between LC50s of mpt 1 and mpt 3 using tagpo extract with computed lethal ratio and confidence limits of 0.861 (0.782, 0.939, p<0.05). Taken together, the results point out that mpt generates accurate and reproducible lethal concentration values. Hence, mpt may be used as an alternative method to screen molluscicides that are active against schistosome snail vectors.

scholarly journals A Random Parameters Ordered Probit Analysis of Injury Severity in Truck Involved Rear-End Collisions

2020 ◽  
Vol 17 (2) ◽  
pp. 395 ◽  
Author(s):  
Xiaojun Shao ◽  
Xiaoxiang Ma ◽  
Feng Chen ◽  
Mingtao Song ◽  
Xiaodong Pan ◽  
...  
Keyword(s):  
Injury Severity ◽  
Probit Analysis ◽  
Ordered Probit ◽  
Ratio Test ◽  
Random Parameters ◽  
Contributing Factors ◽  
Significant Difference ◽  
Car Crashes ◽  
The Difference ◽  
The Impact

Social and economic burdens caused by truck-involved rear-end collisions are of great concern to public health and the environment. However, few efforts focused on identifying the difference of impacting factors on injury severity between car-strike-truck and truck-strike-car in rear-end collisions. In light of the above, this study focuses on illustrating the impact of variables associated with injury severity in truck-related rear-end crashes. To this end, truck involved rear-end crashes between 2006 and 2015 in the U.S. were obtained. Three random parameters ordered probit models were developed: two separate models for the car-strike-truck crashes and the truck-strike-car crashes, respectively, and one for the combined dataset. The likelihood ratio test was conducted to evaluate the significance of the difference between the models. The results show that there is a significant difference between car-strike-truck and truck-strike-car crashes in terms of contributing factors towards injury severity. In addition, indicators reflecting male, truck, starting or stopped in the road before a crash, and other vehicles stopped in lane show a mixed impact on injury severity. Corresponding implications were discussed according to the findings to reduce the possibility of severe injury in truck-involved rear-end collisions.

Molar Absorptivity Values for Aflatoxins and Justification for Their Use as Criteria of Purity of Analytical Standards

1970 ◽  
Vol 53 (1) ◽  
pp. 96-101 ◽  
Author(s):  
J V Rodricks ◽  
L Stoloff ◽  
W A Pons ◽  
J A Robertson ◽  
L A Goldblatt
Keyword(s):  
Thin Layer ◽  
Statistical Study ◽  
Molar Absorptivity ◽  
Confidence Limits ◽  
Components Of Variance ◽  
Significant Difference ◽  
Single Determination ◽  
Comparison Measurements ◽  
Analytical Standards

Abstract Measurements of molar absorptivities in methanol were carried out by two laboratories on samples of anatoxins Bi and Gi prepared and purified independently in four laboratories and on samples of aflatoxins B2 and G2 prepared and purified independently in three laboratories. Molar absorptivities of pure aflatoxins Bi, B2, G1, and G2 in benzene-acetonitrile (98 + 2) were determined at two laboratories. With the exception of aflatoxin G2, no significant difference between aflatoxin samples could be demonstrated. Molar absorptivity values and absorbance ratios for each aflatoxin, based on these data, are given. Statistical 95% confidence limits were established for a single determination of molar absorptivity. A statistical study was made of the components of variance which contribute to the accuracy of the determination of molar absorptivity. A comparison of the fluorescence intensities of spots of various aflatoxin preparations, developed on silica gel-coated thin layer plates, with the amount of aflatoxin in each spotting solution as determined by absorbance measurements, demonstrated the validity of using absorbance and fluorescence comparison measurements for aflatoxin quantitation.

scholarly journals Chemical constituents and insecticidal activity of the essential oil from fruits of foeniculum vulgare miller on larvae of khapra beetle (trogoderma granarium everts)

2013 ◽  
Vol 59 (4) ◽  
pp. 86-96 ◽  
Author(s):  
Iyad Ghanem ◽  
Adnan Audeh ◽  
Amer Abu Alnaser ◽  
Ghaleb Tayoub
Keyword(s):  
Gas Chromatography ◽  
Essential Oil ◽  
Chemical Constituents ◽  
Exposure Period ◽  
Probit Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Fumigant Toxicity ◽  
Foeniculum Vulgare ◽  
Trogoderma Granarium ◽  
Foeniculum Vulgare Miller

Abstract The objective of current study was to determine the chemical constituents and fumigant toxicity of essential oil isolated by hydro-distillation from dry fruit of bitter fennel (Foeniculum vulgare Miller). The chemical composition of the essential oil was assessed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Constituents of the oil were determined as α-pinene (1.6%) and limonene (3.3%), fenchone (27.3%), estragol (3.9%), and (E)-anethole (61.1%). The fumigant toxicity of the essential oil was tested on larvae of the stored product insect Trogoderma granarium Everts. The mortality of larvae was tested at different concentrations ranging from 31.2 to 531.2 μl/l air and at different exposure times (24 and 48 h). Probit analysis showed that LC50 and LC90 following a 48 h-exposure period for essential oil were 38.4 and 84.6 μl/l, respectively. These results showed that the essential oil from F. vulgare may be applicable to the management of populations of stored-product insects.

Potency of Three Botanical Oils Against the Aphis Craccivora Koch (Homoptera: Aphididae) Nymphs Under Laboratory Conditions

2021 ◽  
Vol 19 (1) ◽  
pp. 139-154
Author(s):  
MA Hossain ◽  
MS Yasmin ◽  
MAA Bachchu ◽  
MA Alim
Keyword(s):  
Treatment Time ◽  
Probit Analysis ◽  
Aphis Craccivora ◽  
Tween 20 ◽  
Laboratory Conditions ◽  
Significant Difference ◽  
Aphis Craccivora Koch ◽  
Insect Mortality ◽  
Oil Repellent ◽  
Swietenia Mahagoni

Botanicals are promising and attractive alternatives for pest management. In the present study, three botanical oils namely neem (Azadirachta indica), karanja (Pongamia pinnata) and mehogony (Swietenia mahagoni) were tested against the nymphs of Aphis craccivora Koch to evaluate the toxic and repellent effects under laboratory conditions (25 ± 5oC, 65-75% RH). Four concentrations (0.5, 1.0, 1.5, and 2.0%) along with control were maintained with distilled water and tween-20 was used as emulsifier. Leaf dipped method were used for insect bioassay. Insect mortality was recorded at 24, 48 and 72 hours after intervals while repellency was carried out at 2 hours after intervals upto 10th hours and the collected data were analyzed through MSTAT-C program. Results indicated that all the tested oils had toxic and repellent effects against the A. craccivora nymphs. Among the tested botanical oils, no significant difference was observed in terms of mortality over treatment time. But significant difference was noticed over level of concentrations exerted by the botanical oils. The average highest mortality (28.62%) was recorded by the application of mehogony oil whereas neem oil showed the lowest mortality (27.21%) against the A. craccivora and the mortality was directly proportional to the level of concentrations and hour after treatment (HAT). Probit analysis showed the lowest LD50 values of mehogony oil which revealed the highest toxic effect against the nymph of bean aphid. The highest repellent effect (77.33%) was found in mehogony oil (repellent class IV) among all the botanical oils applied. On the contrary, neem (57.33%) and karanja (55.00%) oils belonged to the same repellent class that is repellent class II. Although all the tested botanical oils evaluated showed toxic and repellent effects but mehogony oil performed as the best potent oil against the nymphs. We therefore suggested using the mehogony oil for the management of bean aphid. SAARC J. Agric., 19(1): 139-154 (2021)

scholarly journals The Toxicity of Srikaya Seed Granules (Annona squamosa L.) with Different Heating Temperatures Against the Larva of Aedes aegypti L.

BIOEDUKASI ◽  
2020 ◽  
pp. 1
Author(s):  
Rima Gloria Purwanto ◽  
Dwi Wahyuni ◽  
Joko Waluyo
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Heating Temperature ◽  
Probit Analysis ◽  
Mosquito Larvae ◽  
Annona Squamosa ◽  
Forest Region ◽  
Randomized Design ◽  
Significant Difference ◽  
Lower Temperature

Abstract: Aedes aegypti L. is a mosquito carrying dengue virus that causes dengue fever, especially in Southeast Asia which is a tropical rain forest region which is a habitat for mosquito growth. Aedes aegypti L. mosquito control is carried out by chemical means of fogging and using abate but this control actually causes Aedes aegypti L. mosquitoes to become resistant or immune to chemical drugs so that a new breakthrough is created by making bioinsecticides biologically to eradicate the Aedes aegypti L. mosquito. with characteristics that are environmentally friendly and do not kill non-target animals and cause the Aedes aegypti L. mosquito not to become resistant. To be able to realize this desire so that the sugar cane granules extract of Annona squamosa L. containing active compounds in the form of annonain and squamosin so that they are toxic to Aedes aegypti L. mosquito larvae. Further research is to test the heating temperature level of the granules of Annona squamosa L. extract temperature of 40 ° C and 60 ° C which is more deadly of Aedes aegypti L. mosquito larvae. This research method uses a completely randomized design with four repetitions. The temperature of 60 ° C uses concentrations of 1 ppm, 6 ppm, 12 ppm, 18 ppm, 24 ppm and 30 ppm. As for the temperature of 40 ° C using concentrations of 1 ppm, 7 ppm, 14 ppm, 21 ppm, 28 ppm, and 35 ppm, each temperature compared with aquadest and abate. Data analyzed using probit analysis to determine the LC50, then followed by a statistical test paired sample T-test with SPSS to find out a significant difference between heating temperatures of 40 ° C to 60 ° C. These results then show that a higher temperature of 60 ° C has a higher level of toxicity compared to a lower temperature of 40 ° C.

scholarly journals The mortality effect of castor bean (Ricinus communis) extract on Aedes aegypti larvae

2010 ◽  
Vol 8 (1) ◽  
pp. 27-30
Author(s):  
TRI NUGROHO WIBOWO ◽  
DARUKUTNI DARUKUTNI ◽  
SUTARTINAH SRI HANDAYANI
Keyword(s):  
Aedes Aegypti ◽  
Castor Bean ◽  
Ricinus Communis ◽  
Negative Control ◽  
Probit Analysis ◽  
Control Group ◽  
Significance Level ◽  
Extract Concentration ◽  
Mortality Effect ◽  
Significant Difference

Wibowo TN, Darukutni, Handayani SS. 2010. The mortality effect of castor bean (Ricinus communis) extract on Aedes aegypti larvae. Biofarmasi 8: 77-81. The aim of this research was to determine the mortality effect of Ricinus communis L. extract on Aedes aegypti L. larvae. This research was an laboratory experimental, with a post-test only controlled group design, and used 750 larvae Instar III of A. aegypti L. that divided into 6 groups (control group, and five treatment groups consisted of 0.10% extract, 0.25% extract, 0.50% extract, 0.75% extract and 1% extract). The sampling technical was a purposive sampling method. The larvae were put into 25 ml experimental liquid for 24 hours. The observation was counting a number of dead larvae in 24 hours. Data were analyzed with one-way ANOVA test continued with Least Significant Difference (LSD) using SPSS for Windows Release statistically with a significance level p<0.05 then continued with a probit analysis. There were 0 larva death at negative control, 23.8 (95%) larvae death at 0.10% extract concentration, 24.6 (98%) larvae death at 0.25% extract concentration, 25.0 (100%) larvae death at 0.50%, 0.75% and 1.00% extract concentration. There was a significant difference in larvae death of A. aegypti in all groups. The LC50 of R. communis extract was 0.01036% (103.6 ppm), therefore it could be concluded that R. communis extract had a mortality effect to A. aegypti larvae.

scholarly journals The use of mice as animal model for testing acute toxicity (LD-50) of toxic shock syndrome toxin

2009 ◽  
Vol 61 (1) ◽  
pp. 170-173 ◽  
Author(s):  
R.S. Dias ◽  
L.S. Carmo ◽  
L.G.D. Heneine ◽  
P.H. Rocha ◽  
C.F. Barbosa ◽  
...  
Keyword(s):  
Animal Model ◽  
Acute Toxicity ◽  
Toxicity Test ◽  
Toxic Shock Syndrome ◽  
Probit Analysis ◽  
Acute Toxicity Test ◽  
Confidence Limits ◽  
Toxic Shock ◽  
Swiss Mice ◽  
Toxic Shock Syndrome Toxin

Acute toxicity test (LD-50) using toxic shock syndrome toxin (TSST-1) was tested in BALB/c, C57BL/6 and Swiss mice. Animals (n = 10) were intraperitoneally injected with TSST-1 (0.01-10.0µg/mouse) followed 4h later by potentiating dose of lipopolysaccharide (75.0µg of LPS - E. coli O111:B4) and cumulative mortality was recorded over 72h. Control animals received either TSST-1 or LPS alone. The data were submitted to qui-Square test and acute toxicity test was calculated by probit analysis (confidence limits expressed as µg toxin/kg). BALB/c mice was the most sensitive (20.0µg/kg, 95% confidence limits: 9.0-92.0) followed by C57BL/6 (38.5µg/kg, 95% confidence limits: 9.11- 401.6). Data from Swiss mice was not conclusive, indicating only low sensitivity. Selection of the animal model and standardization of the experiment are fundamental for the development of serum neutralization tests used for final quality control of vaccine production.

Simple, Highly Selective Screening Method for Barbiturates in Urine

1975 ◽  
Vol 21 (11) ◽  
pp. 1609-1611 ◽  
Author(s):  
František Pehr
Keyword(s):  
Screening Method ◽  
Colorimetric Method ◽  
Probit Analysis ◽  
Selective Screening ◽  
Confidence Limits ◽  
Violet Color ◽  
Color Reagent ◽  
Excretion Study ◽  
Sodium Phenobarbital ◽  
Ether Phase

Abstract I present a new, simple colorimetric method for detecting and estimating barbiturates in urine. After the barbiturates are extracted with ether, an aliquot of the washed ether phase is added to the color reagent (a bivalent mercury/dithizone chelate in chloroform). On addition of diluted pyridine and shaking, a pinkish-violet color appears if a barbiturate is present. The overall sensitivity of the above method was evaluated by probit analysis in the case of sodium phenobarbital. The concentration of sodium phenobarbital in urine detectable at least 99% of the time was 6.72 mg/liter, with 95% confidence limits of 5.37 to 10.36 mg/liter. Sodium phenobarbital, 10 mg/liter, can be detected in the presence of phenytoin (50 mg/liter), glutethimide (100 mg/liter), or bemegride (100 mg/liter). The whole procedure requires &lt;10 min. An excretion study illustrates application of the procedure

scholarly journals Emergency Ambulance Dispatch and Drive Times: An Analysis of Prehospital Vehicular Response in the Kingdom of Bhutan

2019 ◽  
Vol 34 (s1) ◽  
pp. s125-s125
Author(s):  
Jenevieve Kincaid ◽  
Charles Mize ◽  
Mila Dorji
Keyword(s):  
Emergency Response ◽  
Complete Data ◽  
Emergency Vehicle ◽  
Response Data ◽  
Medical Response ◽  
Ambulance Dispatch ◽  
Significant Difference ◽  
Emergency Ambulance ◽  
Activation Times ◽  
National Emergency

Introduction:The Kingdom of Bhutan is a small, mountainous country with limited financial resources. Its population is scattered in hard-to-reach villages with poor road access. Ambulance drivers piloting Toyota Landcruisers provide the majority of the country’s emergency response and are dispatched by the national emergency response center (Health Help Service/112) to calls in the nation’s twenty districts.Aim:By collecting and analyzing prehospital response data, we aimed to describe Bhutanese emergency medical response (EMS) ambulance activities and make system-wide recommendations to improve the speed of emergency vehicle dispatch, reduce the time between ambulance activation and ambulance arrival on scene, and adequately describe emergency vehicle drive time as it relates to distance driven.Methods:The following data was compiled in Excel: Dispatch center phone records, EMS ambulance activation times, drive times, vehicle geospatial data, and written records of ambulance drivers. No identifiable data was collected.Inclusion Criteria: All prehospital calls from 2017 and 2018 where complete data was available.Exclusion Criteria: Complete data unavailable, i.e. geographic data without a matching call or report.Statistical Tools: SPSS Statistics Version 25, NVivo 12-12.2.0.3262.Results:Preliminary analysis of the data shows a significant difference between data collected and data previously reported, the speed of emergency vehicular response and dispatch, drive times, and distance traveled. Facility transfer rather than scene response was found to take more time.Discussion:Due to adverse road conditions, lengthy drive times, and an inadequate number of personnel and satellite ambulance locations, we recommend optimizing ambulance location using an optimization model that will minimize the number of ambulances needed and maximize response time. Future considerations may include adding a ground arm to the Bhutan Emergency Aeromedical Retrieval team, or a second aeromedical team in the eastern part of the country.

scholarly journals The colonization resistance of the digestive tract in different animal species and in man; a comparative study

1990 ◽  
Vol 105 (2) ◽  
pp. 237-243 ◽  
Author(s):  
D. Van Der Waaij ◽  
B. D. Van Der Waaij
Keyword(s):  
Digestive Tract ◽  
Bacterial Contamination ◽  
Animal Species ◽  
Confidence Limits ◽  
Colonization Resistance ◽  
Faecal Samples ◽  
Significant Difference ◽  
Accurate Comparison ◽  
The Mean ◽  
Sources Of Contamination

SUMMARYThe present study has attempted to determine the colonization resistance (CR) of the digestive tract by biotyping Enterobacteriaceae in four faecal samples per subject of five different animal species as well as man. The results indicate that the degree of bacterial contamination with Enterobacteriaceae from the environment may strongly influence the outcome. Both conventionally living chicken and man, showed a much wider range of the ‘confidence limits of the mean’ of the mean number of biotypes per faecal sample between individual subjects, than was found between subjects maintained under laboratory circumstances. Yet there appeared a statistically significant difference in CR between some of the animal species as a group. Man did not differ from monkeys, however, both differed from the rodents species studied. Monkeys differed also from dogs and the latter from rodents. It is concluded that the CR measured by determining the mean number of biotypes of Enterobacteriaceae can only be used for accurate comparison of the CR between subjects, if the ‘bacteriological environment’ is known; i.e. the sources of contamination.

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