Nitrogen fertilization and use efficiency in an intercrop system of cassava (Manihot esculenta Crantz) and soybean (Glycine max (L) Meril.)

Experiments were conducted at the Department of Crop Science, University of Nigeria, Nsukka Research farm during the 2008 and 2009 cropping seasons to determine the effects of intercropping cassava and soybean on cassava tuber and soybean grain yields respectively and on nitrogen use efficiency of cassava at the intercropping system. The experiment for each year was laid out in a factorial arrangement in randomized complete block design (RCBD). The treatments were the nitrogen rates, sole soybean (TGM 579), sole cassava (TMS 30572) and cassava + soy bean intercrop. Intercropping cassava with soybean showed a significant (P ≤ 0.05) yield advantage over sole cropping system in 2008. Increased fertilizer rates up to 90 kg N/ha-1 increased fresh cassava yield in sole cropping system, while in the intercrop, increased application of nitrogen at 60 kg N decreased cassava tuber yield. The cassava nitrogen use efficiency (NUE) increased with increase in applied nitrogen up to 60 kg N/ha-1 and then decreased beyond this point. Similar trend was observed in 2009, except that total harvested cassava tuber yield was significantly higher in 2009 than that obtained in 2008. This result suggests that intercropping cassava with soybean with or without application of nitrogen is beneficial but high doses of nitrogenous fertilizer in sole soybean field is uneconomical and should be avoided.Key words: Cassava, soybean, intercrop, sole crop, nitrogen use efficiency

Postnatal probiotic supplementation can prevent and optimize treatment of childhood asthma and atopic disorders: a systematic review of randomized controlled trials

Background: Although several randomized controlled trials (RCTs) published over the past 5 years show that prenatal or postnatal probiotics may prevent or optimize the treatment of childhood asthma and atopic disorders, findings from the systematic reviews and meta-analyses of these studies appear inconsistent. More recent RCTs have focused on postnatal probiotics, and linked specific probiotic strains to better disease outcomes. Objective: This systematic review aimed to determine if postnatal probiotics are as effective as prenatal probiotics in preventing or treating childhood asthma and atopic disorders. Methods: We searched the PubMed, Medline, Google Scholar, and EMBASE databases for RCTs published within the past 5 years (from 2017 to 2022). We included only full-text RCTs on human subjects published in or translated into the English language. We retrieved relevant data items with a preconceived data-extraction form and assessed the methodological quality of the selected RCTs using the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials. We qualitatively synthesized the retrieved data to determine any significant differences in study endpoints of the probiotic and placebo groups. Results: A total of 1,320 participants (688 and 632 in the probiotic and placebo groups) from six RCTs were investigated. One RCT showed that early Lactobacillus rhamnosus GG (LGG) led to a reduction in the cumulative incidence rate of asthma. Another study demonstrated that mixed strains of Lactobacillus paracasei and Lactobacillus fermentum could support clinical improvement in children with asthma while one trial reported a significant reduction in the frequency of asthma exacerbations using a mixture of Ligilactobacillus salivarius and Bifidobacterium breve. Three trials showed that a combination of LGG and Bifidobacterium animalis subsp lactis, Lactobacillus rhamnosus alone, and a probiotic mixture of Lactobacillus LOCK strains improved clinical outcomes in children with atopic dermatitis and cow-milk protein allergy. Conclusions: Postnatal strain-specific probiotics (in single or mixed forms) are beneficial in preventing and treating atopic dermatitis and other allergies. Similarly, specific strains are more effective in preventing asthma or improving asthma outcomes. We recommend more interventional studies to establish the most useful probiotic strain in these allergic diseases

Separation of oil palm kernel and shell mixture using soil and palm ash slurries

This study investigated the possibility of separating oil palm kernel and shell mixture using media other than clay in wet separation. The separation efficiency of each medium ["Ikwube" (anthill), palm ash and sandy loam soil] was compared with that of clay. The effect of media type, specific gravity of the slurry, pH and slurry viscosity on the efficiency of separation were studied. The media/water ratio of 0.20:1, 0.30:1, 0.40:1, and 0.50:1 by weight were prepared in four aluminum pots for each medium at a time and each used to separate 20kg of cracked nut (palm kernel and shell mixture). The specific gravity and viscosity increases with increase in media/water ratio while the pH decreases. Higher slurry viscosity resulted in a better separation but there is decrease in the efficiency when viscosity is above 3.5 and 5.5 cP for clay and "Ikwube" respectively. The suitable media slurries were found to have specific gravities between 1.04 and 1.12. The optimum condition in which separation efficiency was found in the media/water ratio of 0.30:1. Among the media used, "Ikwube" was found to be comparable to clay at a medium-to-water ratio of 0.30:1 giving 98.93% efficiency. Thus, it is recommended that "Ikwube" can be used in place of clay for wet separation.Key words: Oil Palm Kernel, Kernel Shell, Separation, Clay Soil, “Ikwube” (anthill)

Future changes in seasonal-mean precipitation over West Africa under the representative concentration pathways

This study analysed the future changes in seasonal - mean precipitation over West Africa during the mid (2040 - 2065) twenty first century using the Norwegian Earth System Model version 1 (NorESM1 - M). The NorESM1 - M has ~1.89° x 2.5° horizontal atmospheric resolution and 26 vertical levels. The skill of the model in reproducing the observed seasonal - m ean precipitation distribution was evaluated for the historical period (1980 - 2005) using satellite derived precipitation data from the Global Precipitation Climatology Project. Using three possible future levels of atmospheric greenhouse gas concentrations - the Representative Concentration Pathways (RCPs) of 2.6Wm - 2 , 4.5Wm - 2 and 8.5 Wm - 2 , we calculated the projected changes in seasonal - mean precipitation over West Africa for the mid - twenty first c e n t u r y. The projected changes show that the transition to dry season (September-October-November)will experience the highest amounts of increase. Overall, RCP 4.5 projects higher levels of precipitation change compared to the other two RCPs. This points to a non - linear effect of intensified greenhouse forcing on precipitation over West Africa; suggesting that after a particular level of greenhouse gas concentrations further increase may have little or no effect on the regions precipitation. Keywords : West Africa, Precipitation, Climate Change Projections, NorESM 1 - M, RCP

Denial of Service (DoS) in Internet Protocol (IP) Network and Information Centric Network (ICN): An Impediment to Network Quality of Service (QoS).

This paper compares and analyses the Denial-of-Service attacks in the two different Network architectures. The two architectures are based on different routing approaches: Hop-by-Hop IP routing and source-routing using Bloom filters. In Hop-by-Hop IP routing, the packet header contains the address, and the route is decided node by node. Forwarding in this method requires a node to have a routing table which contains the port through which the packet should traverse depending on the address of the destination. Instead in source-routing, the forwarding identifier is encoded with the path a packet should take and it is placed in the packet header. The forwarding identifier in this approach does not require a forwarding table for look ups like the IP routing; it relies on Line Speed Publish/Subscribe (LIPSIN) forwarding solution that focuses on using named links not nodes or interfaces. The forwarding identifier encompasses a set of Link ID’s which specifies the path to the recipient and they are encoded in a Bloom filter. The In-packet Bloom filters serve as both path selectors and as capabilities, and they are generated dynamically. However, this thesis is going to focus on the latter network technology by looking at both its benefits and drawbacks as well as analysing the possibilities of having a Denial of service attack. Keywords: DoS, DDoS, TCP/IP Protocol Suite, ICMP flood, E-mail Bomb, Ping of Death, TCP and UD

Comparative Analysis of QoS Guarantee on IEEE 802.11e and IEEE 802.11g Wireless Local Area Networks

For this project, we propose to compare the 802.11g and the 802.11e Wireless Local Area Networks (WLANs). The 802.11g WLAN standards are good for data applications. However, the 802.11g standard is not well-equipped to deal with the intended delay and bandwidth requirements of multimedia applications, such as video and voice over wireless IP. For this reason, an approved amendment (802.11e) was added to the IEEE 802.11 standard. The 802.11e implements Quality of Service (QoS), which enables features through changes in the Medium Access Control (MAC) layer. The performance of 802.11e will be evaluated using OPNET simulation and compared with the 802.11g WLAN standard.   Keyword: QoS, IEEE 802.11, WLAN, MAC, OPNET, WiFi, CSMA/CA

Quality Aspects of African Salad

The proximate and microbiological quality of African salad a special salad recipe native to Nigeria was investigated in order to provide scientific, research based information on the nutritional and micro floral composition of this exotic delicacy. Samples of salad were purchased from six food vending sites which serve as the major business and residential area in Owerri. The predominant bacterial isolates from African salad belong to Bacillus spp, Staphylococcus spp, Escherichia coli, Enterococci and Serracia. The fungal spp isolated include Saccharomyces, Mucor, Rhizopus, Penicillium and Aspergillus. The mean total aerobic plate count range from 7.7x1011 to 4.8x1012, coliform count range from 8.5x1010 to 3.5x1011 and fungal count range from 6.6x109 to 4.7x1010. Based on the specifications by International Commission for Microbiological Specification for Foods (ICMSF), the level of contaminations was unacceptable and could pose health challenge. The chemical composition of the African salad samples consist of carbohydrate (21.07%), protein (4.38%), fat (7.80%), fiber (3.29%), and moisture (62.72%). Energy value of 169.30 kcal and minerals were recorded. African salad as seen from this report is a nutritious food, fit for all age groups. Special care however, has to be taken in its preparation as contaminants could be introduced through the ingredients. Education of food handlers and the general public on food safety measures, effective Hazard Analysis Critical Control Point (HACCP) application and Good Manufacturing Practices (GMP) implementation is imperativ

Determination of Erosivity of Enugu State

To combat erosion, there is need for adequate examination of soils and factors of erosion. The study of Erosivity is vital for effective soil conservational planning and agricultural activities in Enugu State of Nigeria of West Africa, and other parts of the world. In this study, rainfall amount and duration were obtained and used in the determination of rainfall intensities in Enugu regions. These rainfall records were used in calculating the three erosivity indices namely; the maximum 30-minute intensity, kinetic energy greater than 25, and peak storm intensity. With the aid of the above data, erosivity of Enugu was uncovered. This was achieved by taking the average of the calculated years. This Erosivity value can be used in modeling a general soil loss equation for all soil types in Enugu. This general soil loss equation can be used to predict erosion in Enugu region. Also, from the force impact of rain capable of causing erosion, erosive rain were separated from non erosive rain using the method based upon the concept that there is a threshold value of intensity at which rain starts to be erosive. With this insight, one can also predict future erosive rain and non erosive rain using the weather forecast data. With the knowledge of these predictions, erosion prevention technique may be applied in areas of possible future occurrence rather than remediating soil after erosion hazard

Qualitative Investigation of the Performance of Real-Time Application of IEEE 802.16e standard WiMAX Relay Networks

The ability of an application to adapt its behavior to changing network conditions depends on the available bandwidth, throughput, delay and packet loss in a network path. These are of major importance in congestion control, streaming applications, quality of service verification, relay selection and many other areas in WiMAX relay stations. Mobile WiMAX, which is based on the IEEE 802.16e standard, provides support for and enables full mobility to users. In an effort to optimize and enhance the overall network throughput, this paper will propose a mobile relay framework. WiMAX is based on the IEEE 802.16e standard, and can support various types of handovers, while allowing for full mobility from the user endpoint. Different methodologies were used to compare different aspects of WiMAX relay stations including throughput, delay, SNR and network load. OPNET modular was used to develop and measure these set of network performance metrics. To accurately measure and evaluate the aforementioned network parameters we employed techniques that were able to process large amounts of data, this aided in provision of much more informed recommendations as to the type of relay station modes that should be installed engender enhanced, improved and optimal Quality of Service (QoS) within the network perimeter. This paper measured the overall network throughput, delay, SNR and network load of relay networks comprising mainly of multimedia applications. Keywords: WiMAX, QoS, Relay Station, Simulation, Topology, Throughput, Delay, Packet Los