Deformation and Dehulling of Sponge Gourd (Luffa aegyptiaca) Seeds

This work presents the compressive strength properties of sponge gourd (Luffa aegyptica) seeds to facilitate the design or adaptation of an appropriate dehuller. The sizes and shape indices of the seed and kernel, and the clearance of the kernel from the seed coat were determined. The seed samples were subjected to uni-axial quasi-static compression tests at 1.0 mm min−1 along the minor and the major axes. The fracture resistance, stiffness modulus, modulus of elasticity, toughness, and maximum elastic deformation of the seed were obtained from the force-deformation curve. The geometric mean diameters varied from 4.0 to 4.5 mm for the seed and 1.6 to 3.9 mm for the embedded kernel; while their corresponding sphericities were 0.64 and 0.62, respectively. The compressive strength of the seed varied with loading orientation. The seed exhibited larger deformation but lower stiffness along the major axis than the minor axis. The force required for rupturing the hull were 95 N along the major axis and 81 N along the minor axis; while the corresponding energy required were 95 and 40 m

A Table Mounted Device for Cracking Dika Nut (Irvingia gabonensis)

A simply designed machine for cracking dika nut was fabricated. The nut is fed by hand inbetween a toggle mechanism comprising of the slider and a fixed block. Fracture mechanism was based on the deformation characteristics of dried dika nut under uni-axial compression. When actuated, the slider compresses the nutshell to failure along its line of symmetry. The experimental machine gave 100% cracking efficiency but with 24% kernel breakage in cracking sun-dried dika nut at 6.6% moisture content (w.b). The machine provides a viable and effective technique for safe dika kernel extraction

A table mounted device for cracking dika nut (Irvingia gabonensis)

A simply designed machine for cracking dika nut was fabricated. The nut is fed by hand inbetween a toggle mechanism comprising of the slider and a fixed block. Fracture mechanism was based on the deformation characteristics of dried dika nut under uni-axial compression. When actuated, the slider compresses the nutshell to failure along its line of symmetry. The experimental machine gave 100% cracking efficiency but with 24% kernel breakage in cracking sun-dried dika nut at 6.6% moisture content (w.b). The machine provides a viable and effective technique for safe dika kernel extraction

Extinction of cue-evoked food seeking recruits a GABAergic interneuron ensemble in the dorsal medial prefrontal cortex of mice

Animals must quickly adapt food-seeking strategies to locate nutrient sources in dynamically changing environments. Learned associations between food and environmental cues that predict its availability promote food-seeking behaviors. However, when such cues cease to predict food availability, animals undergo 'extinction' learning, resulting in the inhibition of food-seeking responses. Repeatedly activated sets of neurons, or 'neuronal ensembles', in the dorsal medial prefrontal cortex (dmPFC) are recruited following appetitive conditioning and undergo physiological adaptations thought to encode cue-reward associations. However, little is known about how the recruitment and intrinsic excitability of such dmPFC ensembles are modulated by extinction learning. Here, we used in vivo 2-Photon imaging in male Fos-GFP mice that express green fluorescent protein (GFP) in recently behaviorally-activated neurons to determine the recruitment of activated pyramidal and GABAergic interneuron mPFC ensembles during extinction. During extinction, we revealed a persistent activation of a subset of interneurons which emerged from a wider population of interneurons activated during the initial extinction session. This activation pattern was not observed in pyramidal cells, and extinction learning did not modulate the excitability properties of activated neurons. Moreover, extinction learning reduced the likelihood of reactivation of pyramidal cells activated during the initial extinction session. Our findings illuminate novel neuronal activation patterns in the dmPFC underlying extinction of food-seeking, and in particular, highlight an important role for interneuron ensembles in this inhibitory form of learning

Weibull approach to brake pad wear analysis in the Nigerian market

In this study, we evaluated the wear properties of four brands of brake pad available in the Nigerian market. In particular, we assessed the tribo performance and service life of the brake pads. We purchased four commercial brands of brake pads used in light duty cars and coded them as AU, SN, TY and SM, respectively. A small piece of the brake pad lining materials was carefully chiseled from the back plates to obtain samples for the experiments. We conducted Brinell hardness tests using a tensometer and a pin-on-disc test rig to determine the coefficient of friction and the wear characteristics of the materials. We then correlated the wear on each set of brake pads with the running time and used Weibull’s equation to determine average service life. Sample TY exhibited the highest hardness value (29.09) and sample SN the lowest (10.05). The determined coefficients of friction ranged between 0.3–0.36, with sample AU exhibiting the lowest value and sample SM the highest. Sample SN showed the lowest wear rate of 3.53 × 109 g/min, while the wear rates of samples TY, AU, and SM were 5.64 × 108, 8.19 × 109, and 2.10 × 108 g/min, respectively. The relative service life of samples SN, TY, and AU were similar, with average values of 2778.09, 2725.41, and 2717.34 min, respectively, and SM had a relatively low service life (2017.82 min). We conclude that the overall performances of Nigerian brake pads do not meet all the specifications for friction materials used in road vehicle brake linings and pads

Factors influencing the utilization of public primary health care facilities in Kumbotso Local Government Area of Kano State, Nigeria

This study is concerned with the examination of factors responsible for the utilization of public primary healthcare services in Kumbotso Local Government Area of Kano State. Primary health care (PHC) can be considered the first level of contact between the patient and the health care system. The Andersen Model of Healthcare Utilisation was used as theoretical guide and frame of analysis in the study. The model is a conceptual framework developed and used to understand health behaviour and possible reasons for utilization of available healthcare facilities and services. The study is a survey research design. A total of 295 respondents were sampled for the study. These include 285 members of the public who were sampled through a multi stage cluster sampling for questionnaire administration and 10 other respondents (Doctors, Nurses, and Community Health Extension Workers) who were purposively sampled for in-depth interview. The study utilized both qualitative and quantitative instruments for data collection. The findings revealed that awareness has influence on the utilization of PHC services in the study area. It also revealed that even though there is high rate of patronage of PHC facilities in the area, respondents reported facing problems associated with availability of drugs, healthcare personnel for effective PHC delivery. It recommended that the government should ensure compliance with the WHO benchmark for PHC delivery.Keywords: Primary health care, Awareness, Availability, Access, Health workers behaviou

Regional differences in striatal neuronal ensemble excitability following cocaine and extinction memory retrieval in Fos-GFP mice

Learned associations between drugs of abuse and the drug administration environment play an important role in addiction. In rodents, exposure to a drug-associated environment elicits conditioned psychomotor activation, which may be weakened following extinction learning. While widespread drug-induced changes in neuronal excitability have been observed, little is known about specific changes within neuronal ensembles activated during the recall of drugenvironment associations. Using a cocaine conditioned locomotion procedure, the present study assessed the excitability of neuronal ensembles in the nucleus accumbens core and shell (NAccore and NAcshell), and dorsal striatum (DS) following cocaine conditioning and extinction in Fos-GFP mice that express green fluorescent protein (GFP) in activated neurons (GFP+). During conditioning, mice received repeated cocaine injections (20 mg/kg) paired with a locomotor activity chamber (Paired) or home cage (Unpaired). 7-13 days later both groups were re-exposed to the activity chamber under drug-free conditions, and Paired, but not Unpaired, mice exhibited conditioned locomotion. In a separate group of mice, conditioned locomotion was extinguished by repeatedly exposing mice to the activity chamber under drugfree conditions. Following the expression and extinction of conditioned locomotion, GFP+ neurons in the NAccore (but not NAcshell and DS) displayed greater firing capacity compared to surrounding GFP– neurons. This difference in excitability was due to a generalized decrease in GFP– excitability following conditioned locomotion, and a selective increase in GFP+ excitability following its extinction. These results suggest a role for both widespread and ensemble-specific changes in neuronal excitability following recall of drug-environment associations