520 research outputs found
Invasive bacterial infections in Gambians with sickle cell anaemia in an era of widespread Pneumococcal and Haemophilus influenzae type B vaccination
Background: There is relatively little data on the aetiology of bacterial infections in patients with sickle cell anaemia (SCA) in West Africa, and no data from countries that have implemented conjugate vaccines against both Streptococcus pneumoniae and Haemophilus influenzae type b (Hib). Methods: We conducted a retrospective analysis of SCA patients admitted to the Medical Research Council Unit, The Gambia during a five-year period when there was high coverage of Hib and Pneumococcal conjugate vaccination. We evaluated 161 admissions of 126 patients between April 2010 and April 2015. Results: Pathogenic bacteria were identified in blood cultures from 11 of the 131 admissions that had cultures taken (8.4%, 95% CI 4.5-14.1%). The most frequent isolate was Salmonella Typhimurium (6/11; 54.5%), followed by Staphylococcus aureus (2/11; 18.2%) and other enteric Gram-negative pathogens (2/11; 18.2%) and there was one case of H. influenzae non-type b bacteraemia (1/11; 9.1%). There were no episodes of bacteraemia caused by S. pneumoniae or Hib. Conclusions: The low prevalence of S. pneumoniae and Hib, and the predominance of non-typhoidal Salmonella as a cause of bacteraemia suggest the need to reconsider optimal antimicrobial prophylaxis and the empirical treatment regimens for patients with SCA
Development and Exploration of Controlled Automated Scissors Car Jack for Vehicle Maintenance
The scissors jack is a commonly used mechanical device for vehicle maintenance and other applications. However, its operation requires significant energy input, posing challenges and complexities, particularly for certain demographics. In response, this paper presents a novel approach to automate the scissors car jack, integrating it with an Android application to enhance energy efficiency, ease of operation, and safety. The motorized lifting system incorporates a car wiper DC motor with an internal gearing system to drive the lead screw of the scissors jack, enabling smooth upward and downward motions. An electrical circuit, comprising a microcontroller, voltage regulator crystal oscillator, diode, resistor, transistor, relay, and Bluetooth module was designed to power the motor through the vehicle's 12V cigarette port and control its rotational direction. Furthermore, an Android application, developed using the MIT App Inventor, serves as a remote control for the DC motor. Through this research, significant advancements in energy efficiency and operational convenience are achieved, while also ensuring enhanced safety during vehicle maintenance. The integration of the scissors jack with an Android application allows users to remotely control the lifting process, providing a more user-friendly and intuitive experience. The findings contribute to the fields of automotive technology, automation, and mechanical systems by offering an innovative solution for efficient and safe vehicle maintenance. In conclusion, this paper presents an automated scissors car jack system integrated with an Android application, showcasing improved energy efficiency, ease of use, and safety. The research findings provide valuable insights for practitioners and researchers alike, advancing knowledge and practice in the field of automotive maintenance and automation
Investigating the response of leaf area index to droughts in southern African vegetation using observations and model-simulations
In many regions of the world, frequent and continual dry spells are exacerbating drought conditions, which have severe impacts on vegetation biomes. Vegetation in southern Africa is among the most affected by drought. Here, we assessed the spatiotemporal characteristics of meteorological drought in southern Africa using the standardized precipitation evapotranspiration index (SPEI) over a 30-year period (1982–2011). The severity and the effects of droughts on vegetation productiveness were examined at different drought timescales (1- to 24-month timescales). In this study, we characterized vegetation using the leaf area index (LAI) after evaluating its relationship with the normalized difference vegetation index (NDVI). Correlating the LAI with the SPEI, we found that the LAI responds strongly (r=0.6) to drought over the central and southeastern parts of the region, with weaker impacts (r<0.4) over parts of Madagascar, Angola, and the western parts of South Africa. Furthermore, the latitudinal distribution of LAI responses to drought indicates a similar temporal pattern but different magnitudes across timescales. The results of the study also showed that the seasonal response across different southern African biomes varies in magnitude and occurs mostly at shorter to intermediate timescales. The semi-desert biome strongly correlates (r=0.95) to drought as characterized by the SPEI at a 6-month timescale in the MAM (March–May; summer) season, while the tropical forest biome shows the weakest response (r=0.35) at a 6-month timescale in the DJF (December–February; hot and rainy) season. In addition, we found that the spatial pattern of change of LAI and SPEI are mostly similar during extremely dry and wet years, with the highest anomaly observed in the dry year of 1991, and we found different temporal variability in global and regional responses across different biomes. We also examined how well an ensemble of state-of-the-art dynamic global vegetation models (DGVMs) simulate the LAI and its response to drought. The spatial and seasonal response of the LAI to drought is mostly overestimated in the DGVM multimodel ensemble compared to the response calculated for the observation-based data. The correlation coefficient values for the multimodel ensemble are as high as 0.76 (annual) over South Africa and 0.98 in the MAM season over the temperate grassland biome. Furthermore, the DGVM model ensemble shows positive biases (3 months or longer) in the simulation of spatial distribution of drought timescales and overestimates the seasonal distribution timescales. The results of this study highlight the areas to target for further development of DGVMs and can be used to improve the models' capability in simulating the drought–vegetation relationship
Pharmacognostic and Anti-diabetic Studies of Chromolaena odorata Linn. (Asteraceae) Powdered Leaves in Alloxan-induced Diabetic Rats
Background: ChromolaenaodorataLinn. (Asteraceae)is being used traditionally for its many medicinal properties including lowering of blood glucose level. However, few and inconsistent information about its antidiabetic potential is available.Objective: to standardize; determine physicochemical and elemental parameters; and evaluate anti-diabetic potential of Chromolaena odorata Linn. (Asteraceae) powdered leaves in alloxan-induced diabetic rats.Materials and Methods: Physicochemical screening of fresh and powdered leaves of C. odorata leaves were respectively determined using a light microscope connected to a standard camera. Elemental analysis was done using Atomic Absorption Spectrometer (AAS) GBC Avanta Model. Thirty-three Wistar rats of either sex weighing 150 – 200 g were used in the procedures. Acute toxicity assessment (LD50) was carried out using the guideline of Organization for Economic Cooperation and Development (OECD). Chromolaena odorata powdered leaves were evaluated using alloxan-induced model.Results: Physicochemical screening of the fresh and powdered leaves confirmed the pharmacognostic parameters of Chromolaena odorata. The moisture content was 6.0 ± 0.07 %, the alcohol soluble extractive was 30 ± 0.05 %. while the water-soluble extractive was 40 ± 0.05%. The elemental analysis of the powdered leaves of C. odorata showed that the leaves contains 29.00mg/L of K, 13.500mg/L of Na, 0.15mg/L of Mn, 4.78mg/L of Mg and 0.30mg/L of Ca. Chromolaena odorata showed no toxicity when it was orally administered to rats (LD50 ≥ 2000 mg/kg). The powdered leaves of Chromolaena odorata at 100, 200 and 300 mg/kg showed dose and time-dependent anti-diabetic activities.Conclusion: The powdered leaves of Chromolaena odorata is non-toxic and preliminary data showed its anti-diabetic potential possibly due to the presence of some phytochemicals and mineral elements identified
 
DEVELOPMENT OF A FULLY POZZOLANIC BINDER FOR SUSTAINABLE CONSTRUCTION: WHOLE CEMENT REPLACEMENT IN CONCRETE APPLICATIONS
Portland Cement (PC) is currently the world most commonly used binder in mortar/concrete applications. PC-based concrete is the world’s most consumed man-made material and consequently puts lots of demand on cement as a binder. PC was later discovered to be non-environmental-friendly material due to its green house (carbon dioxide, CO2) gas emission mainly during production, which contributes greatly to global warming and all its negative impacts worldwide. Concrete production contributes up to 5% of the annual global CO2 emissions of which the bulk is from the production of cement. Other factor debilitating the use of PC is its high cost which further translates to the cost of mortar/concrete-based structures as buildings, making housing less affordable for the citizenry. These PC concerns have led to the development of greener and cheaper alternative binders which have so far evolved the PC to blended and pozzolanic cements. This study is further developing a binder through by combining a pozzolan, Pulverised Calcined Clay (PCC), and calcium hydroxide (Ca(OH)2), Carbide Waste (CW), which is the byproduct of carbide after being used to generate acetylene used in other industrial processes. This study has however shown that these two combinations in the presence of water can produce the C-S-H responsible for strength development as in cement hydration. The CW meant for landfills and pozzolans which could also originate from Agro wastes can be used in the development of an alternative innovative binder to cement. This study tested the pozzolanic binder’s strength to British Standard [29] and X-Ray Fluorescence (XRF) analysis and the results shows that this binder generated a 28-day curing strength of about 11MPa with the potential of generating higher later-day strength. This is about one-third the strength of a 32.5N/R cement grade. XRF analysis shows that the PCC in this study is a class N pozzolan with strength pozzolanic index of 129% and the CW purity level is about 70%-80% Ca(OH)2. The success of this study could culminate to the use of cheaper and more sustainable construction than the most currently used binder, cement
Sonographic diagnosis of pregnancy and study of gestational changes in rabbit-does
This study was carried out to evaluate early pregnancy diagnosis using ultrasound and baseline information on the sonographic features of the reproductive cycle of rabbit-doe. Eight adult does, that had kittened at least once and an Ultrasound machine (Medison S600V®) with a 6.5 MHz transcutaneous curve-linear probe, were used for the study. Rabbit-does were mated naturally by the introduction of a doe to a buck. Abdominal regions were shaved liberally from the level of xyphoid cartilage to the pelvic area and aquasonic gel applied. The uterus was scanned on day 5 post-coitus and thereafter on days 7, 12, 15, 20, 25, 27 and 29, using the bladder as a land mark. Embryonic vesicles, visualized as small anechoic (darkened) structures were first seen on day 7 of gestation. Hypoechoic structures within vesicles corresponding to embryo and placenta were seen on day 12 with an increase in size at day 15 of gestation. Bony formation, bi-parietal diameter, vertebrae column, fetal heart and fetal heart rate were visible with progressive gestational age. This study demonstrated that ultrasound can be used effectively to diagnose pregnancy in rabbit-doe as early as day 7 of gestation. Also there is a correlation between the sonographic observable changes with gestational age.Key words: Ultrasonography, Rabbit, Pregnancy Diagnosis, Gestation
Studies on FT-IR Spectroscopy of modified Montmorillonite clays applied for the removal of T-2 toxin in maiz
Montmorillonite clay has a wide range of industrial applications which include the
removal of mycotoxins in foods and feed because of its low toxicity both in vitro and
in vivo. T-2 toxin is produced mostly by fungal species of Fusarium. Other T-2
producing fungal species are Myrothecium and Stachybotrys. T-2 toxin poses several
health hazards such as dystrophy in the brain, heart, kidney and liver as well as
ulceration and necrosis of the digestive tract in man and animals. To reduce T-2 toxin
in maize, montmorillonite clay modified with lemongrass essential oil (MMT-LGEO)
and montmorillonite clay washed with NaCl (Na-MMT) were applied to maize at a
concentration of 8% and 12% and kept under storage for one month at 30�C. Untreated
maize samples and unmodified montmorillonite clay (MMT) served as controls. The
FTIR spectra were recorded for the two treatments and unmodified montmorillonite
clay (MMT) used for the removal of T-2 toxin in maize. The FTIR spectra of the two
treatments and unmodified clay (MMT) showed the major functional groups as Si-O
and -OH. All Montmorillonite clay has a wide range of industrial applications which include the
removal of mycotoxins in foods and feed because of its low toxicity both in vitro and
in vivo. T-2 toxin is produced mostly by fungal species of Fusarium. Other T-2
producing fungal species are Myrothecium and Stachybotrys. T-2 toxin poses several
health hazards such as dystrophy in the brain, heart, kidney and liver as well as
ulceration and necrosis of the digestive tract in man and animals. To reduce T-2 toxin
in maize, montmorillonite clay modified with lemongrass essential oil (MMT-LGEO)
and montmorillonite clay washed with NaCl (Na-MMT) were applied to maize at a
concentration of 8% and 12% and kept under storage for one month at 30�C. Untreated
maize samples and unmodified montmorillonite clay (MMT) served as controls. The
FTIR spectra were recorded for the two treatments and unmodified montmorillonite
clay (MMT) used for the removal of T-2 toxin in maize. The FTIR spectra of the two
treatments and unmodified clay (MMT) showed the major functional groups as Si-O
and -OH. All the treatments reduced the level of T-2 toxin in maize. However, sodium
montmorillonite (Na-MMT) and montmorillonite clay modified with lemongrass
essential oil (MMT-LGEO) were more efficient than unmodified montmorillonite clay
(MMT) in the removal of T-2 toxin in maizethe treatments reduced the level of T-2 toxin in maize. However, sodium
montmorillonite (Na-MMT) and montmorillonite clay modified with lemongrass
essential oil (MMT-LGEO) were more efficient than unmodified montmorillonite clay
(MMT) in the removal of T-2 toxin in maiz
Price Transmission, Volatility and Discovery of Gram in Some Selected Markets in Rajathan State, India
Market integration in many agricultural commodities had been extensively studied for the insight it provides into the functioning of such markets, thus giving valuable information about the dynamics of market adjustment, and whether there exist market imperfection, which may justify government intervention. This study empirically investigated price transmission, volatility and discovery of gram across four wholesale gram markets, viz. Jaipur, Kishangarh, Chomu and Malpura in Rajasthan state of India using Johansen's multivariate cointegration approach, VECM, Granger causality tests, GARCH, EGARCH and ARIMA. Monthly wholesale gram price data spanning from January 2011 to December 2015 sourced from AGMARKNET were used. Multivariate cointegration showed that all the selected gram markets were cointegarted in the long-run, meaning long-run price association among these markets. The degree of market integration observed is consistent with the view that Rajasthan state gram markets are quite competitive; thus, provide little justification for extensive and costly government intervention designed to enhance market efficiency through improve competitiveness. Therefore, in order to sustain the present system of market integration, there is need to evolve mechanism that will generate market information and market intelligence which would serve as a platform for guiding farmers in marketing their produce
Examining the Effects of Oil Price Long Memory and Exchange Rate Long Memory on Stock Market Behavior in Nigeria
The study examined the effect oil price long memory and exchange rate long memory on Nigeria’s stock. We have used ARMA estimating techniques
to assess whether one or both variables exert impact on the stock market in Nigeria. Our result shows that long memory stock price is driven by a long
memory of the exchange rate and long stock of the oil price. We therefore recommend that policymakers pursue policies aimed at stabilizing, on the
one hand, the exchange rate regime and ensuring the economy has a position in net oil exportations. We also recommend the development of portfolio
strategies by market practitioners so that long-term memory in exchange rates as well as in oil pricing are considered when making investment decision
Characterization of Nanoformulations from Montmorillonite clay for the decontamination of zearalenonein cereals using X-ray Diffraction Technique
Montmorillonite clay due to its abundance and environmental friendliness has several
industrial applications among which are the adsorption of mycotoxins in foods and feed. The
mycotoxin; zearalenone (ZEA) is oestrogenic and has been implicated in hormonal and
reproductive issues for both man and animals. Thus, nanoformulations from Montmorillonite
clay and Cymbopogoncitratus (lemongrass) extracts were developed for the reduction of the toxin
in millet. The various formulations include: Montmorillonite clay to which extract of
Cymbopogoncitratus(lemon grass essential oil)has been incorporated (Mont-LGEO),
Montmorillonite clay mixed with C. citratus(lemon grass)powder (Mont-LGP) and
Montmorillonite clay washed with NaCl (Mont-Na). Pure Montmorillonite clay (Mont) and C.
citratus (lemon grass) powder (LGP) served as the controls for the treatment. Each of these
compositions were applied to millet samples at a concentration of 8 % and 12% and stored for 4
weeks. XRD patterns for compositions containing Montmorillonite clay revealed major peaks at
2-Theta value of 20.06° representing Montmorillonite and 26.56° and 68.53°representing quartz.
The level of ZEA in all treated samples was quantified after 4 weeks using the Liquid
Chromatography tandem mass spectrophotometer LC-MS/MS. All the compositions were
effective in the decontamination of zearalenone. Furthermore, C. citratus powder was the most
effective in the decontamination of zearalenone in the cereal after 4 weeks
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