Abstract: This study aims to: a) obtain ethanolic (95% EtOH) and aqueous extracts of Selaginella elmeri, Christella dentata, Elatostema sinnatum, Curculigo capitulata, Euphorbia hirta, Murraya koenigii, Alpinia speciosa, Cymbopogon citratus, Eucalyptus globulus, Jatropha curcas, Psidium guajava, Gliricidia sepium, Ixora coccinea and Capsicum frutescens and screen them for larvicidal activities against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) larvae; b) to fractionate the most active extract and determine the most active fraction; c) to determine the larvicidal properties of the most active extract and fraction against by computing their percentage mortality, LC50, and LC90 after 24 and 48 hours of exposure; and d) to determine the nature of the components of the active extracts and fractions using phytochemical screening. Ethanolic (95% EtOH) and aqueous extracts of the selected plants will be screened for potential larvicidal activity against Ae. aegypti and Ae. albopictus using standard procedures and 1% malathion and a Piper nigrum based ovicide-larvicide by the Department of Science and Technology as positive controls. The results were analyzed using One-Way ANOVA with Tukey’s and Dunnett’s test. The most active extract will be subjected to partial fractionation using normal-phase column chromatography, and the fractions subsequently screened to determine the most active fraction. The most active extract and fraction were subjected to dose-response assay and probit analysis to determine the LC50 and LC90 after 24 and 48 hours of exposure. The active extracts and fractions will be screened for phytochemical content. The ethanolic extracts of C. citratus, E. hirta, I. coccinea, G. sepium, M. koenigii, E globulus, J. curcas and C. frutescens exhibited significant larvicidal activity, with C. frutescens being the most active. After fractionation, the ethyl acetate fraction was found to be the most active. Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, indoles and steroids. A formulation using talcum powder–300 mg fraction per 1 g talcum powder–was made and again tested for larvicidal activity. At 2 g/L, the formulation proved effective in killing all of the test larvae after 24 hours.
Abstract: Surface characteristics of Bacillus megaterium strain
were investigated; zeta potential, FTIR and contact angle were
measured. Surface energy components including Lifshitz-van der
Waals, Hamaker constant, and acid/base components (Lewis
acid/Lewis base) were calculated from the contact angle data. The
results showed that the microbial cells were negatively charged over
all pH regions with high values at alkaline region. A hydrophilic
nature for the strain was confirmed by contact angle and free energy
of adhesion between microbial cells. Adsorption affinity of the strain
toward dolomite was studied at different pH values. The results
showed that the cells had a high affinity to dolomite at acid pH
comparing to neutral and alkaline pH. Extended DLVO theory was
applied to calculate interaction energy between B. megaterium cells
and dolomite particles. The adsorption results were in agreement with
the results of Extended DLVO approach. Surface changes occurred
on dolomite surface after the bio-treatment were monitored; contact
angle decreased from 69° to 38° and the mineral’s floatability
decreased from 95% to 25% after the treatment.
Abstract: This study evaluated the acute toxicity and tissue
distribution of intravenously administered gold nanoparticles
(AuNPs) in male rabbits. Rabbits were exposed to single dose of
AuNPs (300 μg/ kg). Toxic effects were assessed via general
behavior, hematological parameters, serum biochemical parameters,
and histopathological examination of various rabbits’ organs.
Inductively coupled plasma–mass spectrometry (ICP-MS) was used
to determine gold concentrations in tissue samples collected at
predetermined time intervals. After one week, AuNPs exerted no
obvious acute toxicity in rabbits. However, inflammatory reactions
were observed in liver, lungs and kidneys accompanied with mild
absolute neutrophilia and significant monocytosis. The highest gold
levels were found in the spleen and liver followed by lungs, and
kidneys. These results indicated that AuNPs could be distributed
extensively to various tissues in the body, but primarily in the spleen
and liver.
Abstract: Selenium is an-antioxidant which is important for
human health enters food chain through crops. In Kenya Zea mays is
consumed by 96% of population hence is a cheap and convenient
method to provide selenium to large number of population. Several
soil factors are known to have antagonistic effects on selenium
speciation hence the uptake by Zea mays. There are no studies in
Kenya that has been done to determine the effects of soil
characteristics (pH, Tcarbon, CEC, Eh) affect accumulation of
selenium in Zea mays grains in Maize Belt in Kenya. About 100 Zea mays grain samples together with 100 soil samples
were collected from the study site put in separate labeled Ziplocs and
were transported to laboratories at room temperature for analysis.
Maize grains were analyzed for selenium while soil samples were
analyzed for pH, Cat Ion Exchange Capacity, total carbon, and
electrical conductivity. The mean selenium in Zea mays grains varied from 1.82 ± 0.76
mg/Kg to 11±0.86 mg/Kg. There was no significant difference
between selenium levels between different grain batches {χ (Df =76)
= 26.04 P= 1.00} The pH levels varied from 5.43± 0.58 to 5.85±
0.32. No significant correlations between selenium in grains and soil
pH (Pearson’s correlations = - 0.143), and between selenium levels in
grains and the four (pH, Tcarbon, CEC, Eh) soil chemical
characteristics {F (4,91) = 0.721 p = 0.579} was observed. It can be concluded that the soil chemical characteristics in the
study site did not significantly affect the accumulation of native
selenium in Zea mays grains.
Abstract: This study was aimed to measure effective transverse
relaxation rates (R2*) in the liver and muscle of normal New Zealand
White (NZW) rabbits. R2* relaxation rate has been widely used in
various hepatic diseases for iron overload by quantifying iron contents
in liver. R2* relaxation rate is defined as the reciprocal of T2*
relaxation time and mainly depends on the constituents of tissue.
Different tissues would have different R2* relaxation rates. The signal
intensity decay in Magnetic resonance imaging (MRI) may be
characterized by R2* relaxation rates. In this study, a 1.5T GE Signa
HDxt whole body MR scanner equipped with an 8-channel high
resolution knee coil was used to observe R2* values in NZW rabbit’s
liver and muscle. Eight healthy NZW rabbits weighted 2 ~ 2.5 kg were
recruited. After anesthesia using Zoletil 50 and Rompun 2% mixture,
the abdomen of rabbit was landmarked at the center of knee coil to
perform 3-plane localizer scan using fast spoiled gradient echo
(FSPGR) pulse sequence. Afterwards, multi-planar fast gradient echo
(MFGR) scans were performed with 8 various echo times (TEs) to
acquire images for R2* measurements. Regions of interest (ROIs) at
liver and muscle were measured using Advantage workstation.
Finally, the R2* was obtained by a linear regression of ln(sı) on TE.
The results showed that the longer the echo time, the smaller the signal
intensity. The R2* values of liver and muscle were 44.8 ± 10.9 s-1 and
37.4 ± 9.5 s-1, respectively. It implies that the iron concentration of
liver is higher than that of muscle. In conclusion, the more the iron
contents in tissue, the higher the R2*. The correlations between R2*
and iron content in NZW rabbits might be valuable for further
exploration.
Abstract: Developing our knowledge of when pineapple roots
grow can lead to improved water, fertilizer applications, and more
precise culture management. This paper presents current
understanding of morphological traits in pineapple roots, highlighting
studies using incubation periods and various solid MS media treated
with different sucrose concentrations and pH, which directly assess in
vitro environmental factors. Rooting parameters had different optimal
sucrose concentrations and incubation periods. All shoots failed to
root in medium supplemented with sucrose at 5 g/L and no roots
formed within the first 45 days in medium enriched with sucrose at
10 g/L. After 75 days, all shoots rooted in medium enriched with 10
and 20 g/L sucrose. Moreover, MS medium supplied with 20 g/L
sucrose resulted in the longest and the highest number of roots with
27.3 mm and 4.7, respectively. Root function, such as capacity for P
and N uptake, declined rapidly with root length. As a result, the
longer the incubation period, the better the rooting responses would
be.
Abstract: Target of this study was the analysis of the impact of
crude glycerol on canine spermatozoa motility, morphology,
viability, and membrane integrity. Experiments were realized in vitro.
In the study, semen from 5 large dog breeds was used. They were
typical representatives of large breeds, coming from healthy rearing,
regularly vaccinated and integrated to the further breeding. Semen
collections were realized at the owners of animals and in the
veterinary clinic. Subsequently the experiments were realized at the
Department of Animal Physiology of the SUA in Nitra. The
spermatozoa motility was evaluated using CASA analyzer
(SpermVisionTM, Minitub, Germany) at the temperature 5 and 37°C
for 5 hours. In the study, 13 motility parameters were evaluated.
Generally, crude glycerol has generally negative effect on
spermatozoa motility. Morphological analysis was realized using
Hancock staining and the preparations were evaluated at
magnification 1000x using classification tables of morphologically
changed spermatozoa. Data clearly detected the highest number of
morphologically changed spermatozoa in the experimental groups
(know twisted tails, tail torso and tail coiling). For acrosome
alterations swelled acrosomes, removed acrosomes and acrosomes
with undulated membrane were detected. In this study also the effect
of crude glycerol on spermatozoa membrane integrity were analyzed.
The highest crude glycerol concentration significantly affects
spermatozoa integrity. Results of this study show that crude glycerol
has effect of spermatozoa motility, viability, and membrane integrity.
Detected changes are related to crude glycerol concentration,
temperature, as well as time of incubation.
Abstract: The Northeast China (NEC) was the most important
agriculture areas and known as the Golden-Maize-Belt. Based on
observed crop data and crop model, we design four simulating
experiments and separate relative impacts and contribution under
climate change, planting date shift, and varieties change as well
change of varieties and planting date. Without planting date and
varieties change, maize yields had no significant change trend at
Hailun station located in the north of NEC, and presented significant
decrease by 0.2 - 0.4 t/10a at two stations, which located in the middle
and the south of NEC. With planting date change, yields showed a
significant increase by 0.09 - 0.47 t/10a. With varieties change, maize
yields had significant increase by 1.8~ 1.9 t/10a at Hailun and Huadian
stations, but a non-significant and low increase by 0.2t /10a at Benxi
located in the south of NEC. With change of varieties and planting
date, yields presented a significant increasing by 0.53- 2.0 t/10a. Their
contribution to yields was -25% ~ -55% for climate change, 15% ~
35% for planting date change, and 20% ~110% for varieties change as
well 30% ~135% for varieties with planting date shift. It found that
change in varieties and planting date were highest yields and were
responsible for significant increases in maize yields, varieties was
secondly, and planting date was thirdly. It found that adaptation in
varieties and planting date greatly improved maize yields, and
increased yields annual variability. The increase of contribution with
planting date and varieties change in 2000s was lower than in 1990s.
Yields with the varieties change and yields with planting date and
varieties change all showed a decreasing trend at Huadian and Benxi
since 2002 or so. It indicated that maize yields increasing trend
stagnated in the middle and south of NEC, and continued in the north
of NEC.