6,944 research outputs found
Leading particles and diffractive spectra in the Interacting Gluon Model
We discuss the leading particle spectra and diffractive mass spectra from the
novel point of view, namely by treating them as particular examples of the
general energy flow phenomena taking place in the multiparticle production
processes. We argue that they show a high degree of universality what allows
for their simple description in terms of the Interacting Gluon Model developed
by us some time ago.Comment: Presented at Diffraction2002, Alushta, Crimea (Ukraina), August 31 -
September 5, 2002. To be published by Kluwer Academic Publishers (2003)
(necessary style files attached). Rewritten according to the Kluwer
specification
Chemical castration by a single bilateral intra-testicular injection of chlorhexidine gluconate and cetrimide in bucks
Six apparently healthy Borno white bucks weighing 15± 1.6 kg and aged 1.3± 0.3 years were used for this study. Two and half (2.5) ml Purit® (chlorhexidine gluconate 0.3% B.P W/V and cetrimide 3.0% B.P W/V CAPL Lagos) were injected bilaterally into the caudae of each epididymis following sedation with xylazine hydrochloride. The pre-study scrotal circumference was 20.1±1.5cm; Significant decrease in scrotal circumference (P<0.01) 15.8±1.6cm occurred 35 days post-injection. There was no significant difference (P>0.05) between pre-injection semen volume 0.6±2.1ml and 24 hour post-injection semen volume 0.3±1.4cm. Subsequently, only few drops could be collected and from day 20 post- injection, no semen ejaculate could be collected from all the six bucks. Azoospermia was noted from day 16 post-injection with 0% motile cells, 95% dead cells and 25-60% abnormal sperm cells. From this study, Purit® (chlorhexidine gluconate B.P 0.3% W/V and cetrimide B.P 3.0% W/V) can be used as an effective chemical castration agent in small ruminants.Keywords: Buck, Castration, Chemical, Intra-testicular injection, Purit
Quantitative Estimate of Weeds of Sugarcane (Saccharum Officinarum L.) Crop in Ilorin, Southern Guinea Savanna of Nigeria
A survey was conducted in the sugarcane fields of Unilorin Sugar Research Institute, Ilorin in the southern Guinea savanna agro-ecological zone of Nigeria during 2011 and 2012 cropping seasons with an objective to identify the current status of prevalent weeds in rainfed and irrigated sugarcane fields. A quantitative method was employed for the enumeration of weeds. Quadrats were laid along transects and individual weed species in each quadrat was identified and counted. Simpson’s diversity index, Sorensen similarity index and relative abundance were used to determine the weed community structure. A total of 51 weed species belonging to 40 genera within 16 families were identified across the sugarcane fields. Rainfed sugarcane field was higher in weed species (41) than irrigated fields (35 weed species). Rainfed fields also had the diversity index of 28.84 % compared to 21.66% species diversity computed for irrigated fields. The result generally shows that the similarities index of weed species between rainfed and irrigated fields is about 50 %. Among the 10 abundant weed species, two grasses viz. Panicum repens L. and Imperata cylindrica (L.) Raeschel were the most abundant weeds in sugarcane fields followed by Rottboellia cochinchinensis Lour and two sedge weeds Cyperus rotundus L. and Mariscus longibracteatus Cherm. Results obtained from this study would be useful in creating a weed management programme and making informed decision on choice of herbicides. Regular weed survey to identify possible problematic weeds and weed population shifts and direct research toward new or improved weed control measures is thereby recommended.Key words: Sugarcane fields, rainfed, irrigation, survey, weed specie
Emerging Pattern of Forest Bio-Diversity in South West Nigeria: A Spatio-Temporal Analysis of Forest Reserves
The importance of forest resources in any given human society can not be over emphasized. This is so because, for any meaningful development to be achieved and sustained, it requires the harmonization of the forest biodiversity for economic, socio- political as well as ecological balance of the
society. For instance, both timber and non-timber forest products provide income, employment opportunities, etc for the generality of the people living within and around the forest reserves. Traditionally, access to certain forests is forbidden in order to conserve and to manage the forest to achieve forest
resource sustainability. This is so because, it has been discovered that over the years, the rate of exploitation of these resources is unprecedented in the history of forest use in the southwestern part of Nigeria. This paper therefore
set out to examine the traditional values of the forest, the changes that have occurred in the area of the forest in the state and the contemporary arrangement to curtail the spate of deforestation and its concomitant socioeconomic effects on the people. To achieve the above, various relevant literature and theoretical models are examined. Also, both spatial and attribute
data are examined to drive home the argument. Finally, a conclusion will be drawn with recommendations on new forest resources management strategies.
Keywords: Biodiversity, Forest Resources, Sustainable Development, Ecological Balanc
Angular momentum of free variable mass systems is partially conserved
Variable mass systems are a classic example of open systems in classical mechanics with rockets being a standard practical example. Due to the changing mass, the angular momentum of these systems is not generally conserved. Here, we show that the angular momentum vector of a free variable mass system is fixed in inertial space and, thus, is a partially conserved quantity. It is well known that such conservation rules allow simpler approaches to solving the equations of motion. This is demonstrated by using a graphical technique to obtain an analytic solution for the second Euler angle that characterizes nutation in spinning bodies
Antibacterial properties and preliminary phytochemical analysis of methanolic extract of Ocimum gratissium (Scent Leaves)
Methanolic extract of the leaves of Ocimum gratissium (scent leaves) was screened for its phytochemical and antibacterial properties on some clinical bacterial isolates, visa vie as Staphylococcus aureus, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. The agar diffusion technique was used to assay the growth inhibition against the four bacterial isolates. The antibacterial effect of the methanolic extract of Ocimum gratissium was compared to that of some selected commercially available antibiotics. The inhibitory effect of the methanolic extract was comparable at all concentrations tested to the commercially available antibiotics indicating the high potency of the methanolic extract O. gratissium. Results obtained showed, the extract inhibits the growth of the test isolates with diameter of zones of inhibition of 5mm to 10mm for P. aeruginosa, P. mirabilis, E. coli and S. aureus respectively. The Broth microdilution assay gave minimal inhibitory concentration values ranging from 13.5μg/ml to 15.0μg/ml. The result of the phytochemical analysis of the dried leaves extracts revealed the presence of alkaloids, carbohydrate and saponins.
Keywords: Herbalism, Phytochemicals, Scent, Beni
Effect of organic and inorganic fertilizers on regeneration of seedlings of Ricinodendron heudelotii (Baill) Pierre et Pax.
Most soils in the humid tropical zones present a particular problem. Due to leaching, the fertilizer provided by the process of nutrient cycling in tropical rainforest is confined to the top few inches of the soil. Varying quantities of manure and NPK fertilizers were applied to assess their effects on the growth of Ricinodendron heudelotii seedlings, a non-timber-forest-product. Assessment was done by measurements of height, number of leaves, leaf area, seedling biomass, the relative growth rate, and the net assimilation rate. The effects of organic and inorganic fertilizers on plant height and number of leaves were not significant, though their effect on leaf area was significant (p<0.05). The total biomass, relative growth rate, and net assimilation rate under the different treatment combinations had no significant effect on yield. However, fertilizer treatments had a significant effect among the periods of application for the biomass and the net assimilation rate (p<0.05), but had no significant effect on the observation period for the relative growth rate.Keywords: Manure, NPK, non-timber-forest-product, biomass, relative growth rate, net assimilation rate
Brown rot and die-back disease induced by a cucurlionid (Lixus camerunus Klobe) in amaranth (Amaranthus hyhridus L.) in Nigeria
No abstract
Measurement of overall insecticidal effects in experimental hut trials
BACKGROUND: The 'overall insecticidal effect' is a key measure used to evaluate public health pesticides for indoor use in experimental hut trials. It depends on the proportion of mosquitoes that are killed out of those that enter the treated hut, intrinsic mortality in the control hut, and the ratio of mosquitoes entering the treatment hut to those entering the control hut. This paper critically examines the way the effect is defined, and discusses how it can be used to infer effectiveness of intervention programmes.
FINDINGS: The overall insecticidal effect, as defined by the World Health Organization in 2006, can be negative when deterrence from entering the treated hut is high, even if all mosquitoes that enter are killed, wrongly suggesting that the insecticide enhances mosquito survival. Also in the absence of deterrence, even if the insecticide kills all mosquitoes in the treatment hut, the insecticidal effect is less than 100%, unless intrinsic mortality is nil. A proposed alternative definition for the measurement of the overall insecticidal effect has the desirable range of 0 to 1 (100%), provided mortality among non-repelled mosquitoes in the treated hut is less than the corresponding mortality in the control hut. This definition can be built upon to formulate the coverage-dependent insecticidal effectiveness of an intervention programme. Coverage-dependent population protection against feeding can be formulated similarly.
CONCLUSIONS: This paper shows that the 2006 recommended quantity for measuring the overall insecticidal effect is problematic, and proposes an alternative quantity with more desirable propertie
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