580 research outputs found
An Active Turbulence Generation System for the Simulation of Aerodynamic Transients in a Model Wind Tunnel
This paper outlines the creation and validation of an active turbulence generation system (TGS) for the simulation of wind and vehicle-induced transients in a model scale, Âľ open jet, wind tunnel
EFFECT OF ORGANIC TURMERIC (Curcuma longa) FEEDING ON TESTICULAR HISTOLOGY OF RABBITS EXPOSED TO ULTRAVIOLET RADIATION
Thirty six male rabbits of 450-600g weight range fed with mostly organic ingredient feed, were weight-balanced into six treatment groups that received rabbit diets either without (D1) or with organic turmeric (D2) at varying periods within a nine- week experimental period. The treatments were T0, T1, T2, T3, T4 and T5 for control, D2 plus exposure to Ultraviolet (UV) radiation, D2 until radiation, D2 after radiation, D1 throughout the experimental period with UV radiation and D2 throughout the experimental period without UV radiation, respectively. Testicular histology revealed that feeding organic turmeric in the diet before exposure conferred some protection on the testicular tissue while the feeding of organic turmeric in the diet after exposure corrected some of the damage inflicted by exposure to UV radiation. The group (T4) that did not receive organic turmeric showed conspicuous damage in the testicular tissue on exposure to ultraviolet radiation. It was concluded that the inclusion of organic turmeric, simply boiled, dried and powdered in the diet without any sophisticated processing to extract curcumin, could alleviate the histological damage on account of exposure to ultraviolet radiation
Effect of Organic Turmeric (Curcuma longa) Feeding on Testicular Histology of Rabbits Exposed to Ultraviolet Radiation
A total of thirty six male rabbits ranging in weight between 450-600g were weight-balanced into six treatment groups that received rabbit diets either without turmeric (D1) or with turmeric (D2) at varying periods within a nine- week experimental period. The treatments were T0, T1, T2, T3, T4 and T5 for control, D2 plus exposure to UV radiation, D2 until radiation, D2 after radiation, D1 throughout the experimental period with UV radiation and D2 throughout the experimental period without UV radiation, respectively. Testicular histology revealed that feeding organic turmeric in the diet before exposure conferred some protection on the testicular tissue while the feeding of turmeric in the diet after exposure corrected the damage inflicted by exposure to UV radiation. The group (T4) that did not receive turmeric showed conspicuous damage in the testicular tissue on exposure to ultraviolet radiation. It was concluded that organic turmeric could alleviate the histological damage on account of exposure to ultraviolet radiation. Key words: Organic turmeric, Ultraviolet radiation, Rabbit, Testis, Histolog
Climate change adaptation through conservation agriculture: evidence from smallholder farmers in Ondo State, Nigeria
This study identifies the factors influencing the adoption of CA among smallholder farmers in Ondo State, Nigeria. To determine the factors influencing the adoption of CA among smallholder farmers, Tobit regression model was used. From the regression results, minimum tillage, crop rotation, mulching, cost of planting materials, cost of equipment’s are all positively significant at 1% and a unit increase in them will increase the adoption of CA practices in the study area. The primary occupation of the respondents is positively significant at 5% and a unit increase in primary occupation of the respondentsincreases the rate of adopting CA practices by 0.0570868. Age of the respondents is negatively significant at 10% and this implies that a unit increase in age decreases the rate of adopting CA by 0.0018808. Also, household size is positively significant at 10% and a unit increase in households’ size increase the level of adoption of conservation agriculture by 0.0079891. This paper therefore recommends that policies addressing the 3 core principles of CA practices (minimum tillage, crop rotation and mulching) should be re-emphasized so as to improve the food production involve in agricultural value chain activities. Young ones should be encouraged to involve in farming practices especially CA activities. And lastly, cost of equipment and planting materials should be subsidized for farmers so as to foster improved farming, increased food production and hence aid commercialization among smallholder farmers.Keywords: Conservation agriculture, agricultural value chain and smallholder farmer
A microstructural study of superconductive nanocrystalline diamond
A transmission electron microscopy (TEM) study of superconducting nanocrystalline diamond (NCD) continuous layers is reported. The high resolution transmission electron microscopy (HREM) and the diffraction contrast modes of observations are used to reveal the nanograins configuration. Three types of them are observed: first, close to the interface with the Si/SiO2 substrate, 10 to 20 nm-sized diamond
16 seeds resulting from the 5nm size diamond powder deposition before growth that show some regrowth during CVD process, second a diamond overgrown layer, quasi-epitaxially by coalesced columnar NCD grains, and finally, up to the free surface, a thin disordered region composed of nanocrystallites smaller than 6 nm. This last layer was not nominally expected and is attributed to a renucleated-like (RND) diamond layer embedding ultra nanocrystalline grains. Diffraction contrast observations confirm this HREM observed behaviour.6 page
Microbial diversity of a disused copper mine site (Parys Mountain, UK), dominated by intensive eukaryotic filamentous growth
The Parys Mountain copper mine (Wales, UK) contains a wide range of discrete environmental microniches with various physicochemical conditions that shape microbial community composition. Our aim was to assess the microbial community in the sediments and overlying water column in an acidic mine drainage (AMD) site containing abundant filamentous biogenic growth via application of a combination of chemical analysis and taxonomic profiling using 16S rRNA gene amplicon sequencing. Our results were then compared to previously studied sites at Parys Mt. Overall, the sediment microbiome showed a dominance of bacteria over archaea, particularly those belonging to Proteobacteria (genera Acidiphilium and Acidisphaera), Acidobacteriota (subgroup 1), Chloroflexota (AD3 cluster), Nitrospirota (Leptospirillum) and the uncultured Planctomycetota/CPIa-3 termite group. Archaea were only present in the sediment in small quantities, being represented by the Terrestrial Miscellaneous Euryarchaeota Group (TMEG), Thermoplasmatales and Ca. Micrarchaeota (Ca. Micracaldota). Bacteria, mostly of the genera Acidiphilium and Leptospirillum, also dominated within the filamentous streamers while archaea were largely absent. This study found pH and dissolved solutes to be the most important parameters correlating with relative proportions of bacteria to archaea in an AMD environment and revealed the abundance patterns of native acidophilic prokaryotes inhabiting Parys Mt sites and their niche specificities
Solid-phase extraction and high performance liquid chromatography with diode array detection method for the determination of antibiotic residues in poultry tissues
This article presents information on high performance liquid chromatography with diode array detection (HPLC-DAD) method for the simultaneous determination of six antibi- otic residues (enrofloxacin, sulfadimethoxine, sulfamerazine, sulfamethoxazole, sulfamox- ole, and tylosin) in three poultry tissues. The target antibiotic residues were extracted from raw poultry samples following concentration, clean-up through solid phase extraction. The data describe the extraction, determination and screening procedures of these common antibiotic residues in 111 samples of fresh and frozen poultry meats. The limit of detection (LOD) ranged from 5.37–55.4 ng/g, while the quantification limit (LOQ) was in the range of 17.9–184 ng/g, respectively, with minimal matrix effect. The calibration curves obtained exhibited a good linear response with the coefficient of determination, R 2 > 0.996. Some concentrations exceeded their maximum residue limits in most samples. These findings indicated elevated levels of antibiotic residues in tissues of locally produced and illegally imported poultry meat samples
Benefits and limitations of text messages to stimulate higher learning among community providers: participants’ views of an mHealth intervention to support continuing medical education in Vietnam
BACKGROUND: A randomized controlled trial was conducted in 2015 to evaluate a mobile continuing medical education (mCME) intervention that provided daily text messages to community-based physicians’ assistants (CBPAs) in Thai Nguyen Province, Vietnam. Although the intervention failed to improve medical knowledge over a 6-month period, a companion qualitative study provided insights on the views and experiences of intervention participants.
METHODS: We conducted focus group discussions (FGDs) and in-depth interviews (IDIs) among participants randomized to receive text messages containing either simple medical facts or quiz questions. Trained interviewers collected data immediately following the conclusion of the trial in December 2015. Using semi-structured question guides, respondents were queried on their views of the intervention, positive and negative, and perceived impacts of the intervention. During analysis, after learning that the intervention had failed to increase knowledge among participants, we also examined reasons for lack of improvement in medical knowledge. All analyses were performed in NVivo using a thematic approach.
RESULTS: A total of 70 CBPAs engaged in one of 8 FGDs or an IDI. One-half were men; average age among all respondents was 40 years. Most (81%) practiced in rural settings and most (51%) focused on general medicine. The mean length of work experience was 3 years. All respondents made positive comments about the intervention; convenience, relevance, and quick feedback (quiz format) were praised. Downsides encompassed lack of depth of information, weak interaction, technology challenges, and challenging/irrelevant messages. Respondents described perceived impacts encompassing increased motivation, knowledge, collegial discussions, Internet use to search for more information, and clinical skills. Overall, they expressed a desire for the intervention to continue and recommended expansion to other medical professionals. Overreliance on the text messages, lack of effective self-study, and technical/language-based barriers may be potential explanations for intervention failure.
CONCLUSION: As a form of mCME, daily text messages were well-received by community-level health care providers in Vietnam. This mCME approach appears very promising in low-resource environments or where traditional forms of CME are impractical. Future models might consider enhancements to foster linkages to relevant medical materials, improve interaction with medical experts, and tailor medical content to the daily activities of medical staff
Determination of antibiotic residues in frozen poultry by a solid-phase dispersion method using liquid chromatography-triple quadrupole mass spectrometry
Importation of poultry produce into Nigeria through its land borders has heightened, notwithstanding the
government’s ban on such products. This study examined imported frozen poultry products for antibiotic residues
considering their health implications. A solid-phase extraction method using liquid chromatographytandem
mass spectrometry in the positive and negative electrospray ionisation and the multiple reaction
monitoring modes were employed. The antibiotics were extracted with acetonitrile-dichloromethane.
Chromatographic separation was on Waters Acquity UPLC® BEH C18 column with acetonitrile, and water
gradient and the antibiotics analysed using Electrospray positive ionisation polarity switch in a single run of
fourteen minutes. Residues of nineteen (19) antibiotics were found in the three different matrices at different
levels with varying detection frequencies ranging between 2 and 4% (sulfamoxole, penicillin-G, albendazole and
phebendazole) and 14–54% for all the other antibiotics. The highest number of violative samples was found in
the turkey gizzard and chicken muscle. Sulfixosazole had the highest percentage violation of 80.00% in turkey
gizzard while sulfamethoxazole, notwithstanding its lower frequency in chicken muscle had highest maximum
concentration and 100% violation. The presence of these drugs, however, does not pose any immediate health
risk
Distribution of Antibiotic Residues in Non-medicated Poultry Feeds by High-Performance Liquid Chromatography with Diode-array Detection
This paper reports on the determination and distribution of antibiotic drugs in
poultry feeds mainly the layers and growers mash obtained from Ogun state in
Nigeria. Pulverized feed samples were initially treated with phosphate buffer
adjusted to pH 7 and the analytes extracted in an SPE cartridge with ammonium
hydroxide and methanol. The extract reconstituted in phosphate buffer was
determined with high-performance liquid chromatography-diode array detection
(HPLC–DAD). The analytical column was an XTerra MS C18 column, (4.6 mm x
100 mm, 3.5 ÎĽm) with mobile phases consisting of ultrapure water and acetonitrile
mixed with 0.1% HCOOH in gradient elution mode. Data acquisition was achieved
with AgilentChemStation Version B.040.01 SP1 while the analytes were
completely separated under 10 minutes with good resolution and symmetric peaks.
The high correlation coefficient (R2) values (> 0.998, excluding sulfadimethoxine)
indicate a good correlation between analyte concentration and peak areas. Limit of
detection (LOD) and quantitation (LOQ) was between 5.37 and 55.42 ng/g, and
17.91 and 184.74 ng/g, respectively. All the drugs exhibited high mean
concentration values in the two feed types, and there was no significant difference
between their means (p < 0.05). The results clearly showed that feed millers fortify
their feeds with antibiotics mainly sulfonamides in varying amounts without
declaring same, thus compromising security of poultry birds and human consumers
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