SPILLOVERS AND THE RETURNS TO AGRICULTURAL RESEARCH FOR POTATOES

Returns to investments in potato research were estimated for the United States and six subregions. The study combines time-series and cross-sectional data to estimate the supply response for potatoes. Two research variables, research within the state and within the region, were included as exogenous variables to identify spillovers of research results. The rate of return to investments in potato research in the U.S. is estimated at 79%. Of this, 31% accrues to states conducting the research and 69% is accounted for by the spillover effects.Research and Development/Tech Change/Emerging Technologies,

Coronaviruses: a review of their properties and diversity

Human coronaviruses, which hitherto were causative agents of mild respiratory diseases of man, have recently become one of the most important groups of pathogens of humans the world over. In less than two decades, three members of the group, severe acute respiratory syndrome (SARS) coronavirus (CoV), Middle East respiratory syndrome (MERS)-CoV, and SARS-COV-2, have emerged causing disease outbreaks that affected millions and claimed the lives of thousands of people. In 2017, another coronavirus, the swine acute diarrhea syndrome (SADS) coronavirus (SADS-CoV) emerged in animals killing over 24,000 piglets in China. Because of the medical and veterinary importance of coronaviruses, we carried out a review of available literature and summarized the current information on their properties and diversity. Coronaviruses are single-stranded RNA viruses with some unique characteristics such as the possession of a very large nucleic acid, high infidelity of the RNA-dependent polymerase, and high rate of mutation and recombination in the genome. They are susceptible to a number of physical agents and several chemical agents used for disinfection procedures in hospitals and laboratories. They exhibit considerable genetic and host diversity, causing diseases of gastrointestinal and respiratory system in a wide range of vertebrate hosts including humans. The high prevalence of coronaviruses in domestic and wild animals, especially bats and birds, and the propensity for their genomes to undergo mutation and recombination may lead to emergence of new coronaviruses that could pose a serious threat to human and animal health. Keywords: coronaviruses; SARS-CoV; MERS-CoV; SARS-Cov-2; properties; diversity; review French Title: Coronavirus: revue de leurs propriétés et de leur diversité Les coronavirus humains, qui étaient jusqu'à présent des agents responsables de maladies respiratoires bénignes de l'homme, sont récemment devenus l'un des groupes les plus importants d'agents pathogènes humains dans le monde entier. En moins de deux décennies, trois membres du groupe, le coronavirus (CoV) du syndrome respiratoire aigu sévère (SRAS), le syndrome respiratoire du Moyen-Orient (MERS)-CoV et le SRAS-COV-2, sont apparus, provoquant des épidémies qui ont touché des millions et des personnes. a coûté la vie à des milliers de personnes. En 2017, un autre coronavirus, le coronavirus du syndrome de la diarrhée aiguë du porc (SADS) (SADS-CoV) est apparu chez des animaux tuant plus de 24000 porcelets en Chine. En raison de l'importance médicale et vétérinaire des coronavirus, nous avons effectué une revue de la littérature disponible et résumé les informations actuelles sur leurs propriétés et leur diversité. Les coronavirus sont des virus à ARN simple brin avec certaines caractéristiques uniques telles que la possession d'un très grand acide nucléique, une infidélité élevée de la polymérase dépendante de l'ARN, et un taux élevé de mutation et de recombinaison dans le génome. Ils sont sensibles à un certain nombre d'agents physiques et à plusieurs agents chimiques utilisés pour les procédures de désinfection dans les hôpitaux et les laboratoires. Ils présentent une diversité génétique et hôte considérable, provoquant des maladies du système gastro-intestinal et respiratoire dans un large éventail d'hôtes vertébrés, y compris les humains. La forte prévalence des coronavirus chez les animaux domestiques et sauvages, en particulier les chauves-souris et les oiseaux, et la propension de leurs génomes à subir des mutations et des recombinaisons peuvent conduire à l'émergence de nouveaux coronavirus qui pourraient constituer une menace sérieuse pour la santé humaine et animale. Mots-clés: coronavirus; SARS-CoV; MERS-CoV; SRAS-CoV-2; Propriétés; la diversité; la revue   &nbsp

Parasitic diarrhoea in treatment-naïve HIV-positive patients attending the University of Ilorin Teaching Hospital (UITH) Highly Active Antiretroviral Treatment (HAART) Clinic

Background: HIV is a public health issue with diarrhoea being the commonest gastrointestinal symptom especially in individuals with lower CD4+ cell counts. Most times, parasitic infections present as diarrhoea. Depending on geographical location, the pathogens responsible for diarrhoea vary.Aim: To relate the degree of immunodeficiency in HIV-infected patients to diarrhoea as a result of infestation by parasitic agent.Methods: 250 HIV positive and 250 HIV negative participants were recruited. Stool and blood samples were taken from all participants. Macroscopic and microscopic examinations of the stool were done while CD4+ count was estimated from the blood sample collected. Wet preparation of stool sample was done and concentrated stool was used for modified Ziehl Neelsen staining. Results: Diarrhoea was present in 200 participants, 118 of which were among the HIV positive group. Parasites were demonstrated in 82.3% of the test participants with diarrhoea and 17.7% of the controls with diarrhoea. Of the HIV positive with diarrhoea, 70.3% had a CD4 <200 cells/μl and 29.7% had a CD4 of 200-500cells/μl. Parasites in both groups were Ascaris lumbricoides, Balantidium coli, Entamoeba histolytica, Schistosoma mansoni, Hookworm, Strongyloides stercoralis and coccidian parasites though at varying frequencies. Of the 79 with parasites, 60 had single parasitosis, while 19 had multiple parasitosis. CD4 count was the only variable that correctly predicts presence of diarrhoea. Conclusion: Diarrhoea associated with parasitic infection HIV patients is a function of the immune status of the individual.Key words: People Living with HIV/AIDS (PLWHA), HIV/AIDS, diarrhoea, intestinal parasite, HAART NAÏVE, immunosuppressio

Evaluation of compressive strength characteristics of structural-sized Apa (Afzelia bipindensis) and Opon (Lannea schimperi) timber species columns found in Nigeria

The work centers on the compressive strength characteristics of Nigerian Apa (Afzelia bipindensis) and Opon (Lannea schimperi) timber species columns of nominal lengths 200, 400, 600 and 800mm and a nominal width and thickness of 50mm by 50mm. The data revealed that, Apa and Opon have an average density of 652.74 and 472.60kg/m3 respectively. The mean moisture content (MC) of both species were less than the fibre saturation point (FSP) recommended value of 25-30% and the average strength at yield of Apa and Opon are 35.65 and 14.00N/mm2. The derived continuous equations for design of Apa column and Opon column are σ = 47.882-0.009λ and σ =17.211-0.007λ respectively. The results of the reliability analysis show that Apa and Opon timber species have reliability index of 0.64 and 0.65 respectively for a service life of 50 years, assuming other serviceability conditions are met. This design procedure is distinct and more effective than the usual procedure of classifying compression members as short, intermediate and long using their slenderness ratios. The paper therefore recommends the adoption of these equations for the design of compression members from these timber species in Nigeria.Keywords: Apa, Compressive strength, Opon, Reliability, Structural-size

Specific Heat Discontinuity in Impure Two-Band Superconductors

The Ginzburg-Landau coefficients, and the jump of the specific heat are calculated for a disordered two-band superconductor. We start with the analysis of a more general case arbitrary anisotropy. While the specific heat discontinuity at the critical temperature T_c decreases with increasing disorder, its ratio to the normal state specific heat at T_c increases and slowly converges to the isotropic value. For a strong disorder the deviation from the isotropic value is proportional to the elastic electron scattering time. In the case of a two-band superconductor we apply a simplified model of the interaction independent on momentum within a band. In the framework of this model all thermodynamic values can be found explicitly at any value of the scattering rate. This solution explains the sample dependence of the specific heat discontinuity in MgB_2 and the influence of the disorder on the critical temperature.Comment: New results relate to two-band superconductors, 9 pages, 2 figure

Response of clarias gariepinus to dietary castor seeds processed by different methods

Castor seed variously treated by boiling, roasting, boiling and roasting, decorticated lyle treated, boiling and fermenting was tested for improved nutrient content and elimination of toxins. 10% processed castor seed cake (CSC) was included in diets and fed to 180 catfishes for 4-weeks to assay the dietary castor seed based on performance and some biochemical indices. Processing methods other than boiling improved performance and other measured parameters and some diets containing treated CSC produced results even better than that obtained on the conventional diet (p < 0.05). Dietary boiled CSC elicited low feed intake, body weight gain, poor feed efficiency and high mortality of the fed fish relative to the control diet (p < 0.05). Similarly, boiled CSC in diet gave poor results on biological values of specific growth rate, net protein utilization, nitrogen metabolism, protein efficiency ratio compared to the control diet or diets containing CSC treated by methods other than boiling (p < 0.05). The best result was obtained on the diet containing castor seeds treated by boiling followed by roasting (p < 0.05). For optimum utilization of CSC in nutrition of fish, it has to be boiled and roasted

Performance and nutrients digestibility of piglets fed ditary detoxified balanites augyptiaca friuts

A feeding trial was conducted to assess the effect of dietary detoxified Nigerian Balanites aegyptiaca fruits on performance and nutrients digestibility of weanling pigs. Twenty pigs weighing averagely 4.5 ± 0.85kg were used for the experiment which lasted for one month. The pigs were randomly allocated to the five dietary treatments in a completely randomized design. Five diets made of a corn-soy control diet and four others to which 20% of boiled, roasted, boiled and roasted, boiled and fermented respectively were used. Feed consumption and weight gain of pigs maintained on the Balanites based diets were comparable with the conventional diet (p > 0.05). However, efficiency of feed utilization on the Balanites containing diets was inferior to that on the control diet (p 0.05) but protein and fatdigestibility were significantly influenced by dietary Balanites (p 0.05). Nitrogen consumption using indices of protein intake, fecal nitrogen output, daily retainednitrogen and nitrogen retention coefficient were not significantly different from values obtained on the control diet (p > 0.05). It was therefore concluded that Balanites aegyptiaca fruits, when detoxified by any of the traditional methods adopted, could be incorporated in diets for livestock even up to 70% inclusion level without deleterious effects on animal consuming the feed

Prospects and constraints on utilization of Jatropha curcas seeds in animal feedstuff

Combined physical, chemical and biochemical methods were used to process virgin seed meal of Jatropha curcas L. into treated Jatropha Seed Meal (JSM). Graded levels (0, 5, 10, 15, 20 and 25%) JSM treated by the various methods was included in the test diets which were fed ad libitum to 360 albino rats for a month in a single factor design trial. The results revealed that feed intake was numerically highest (p &gt; 0.05) for the rats on the 5 % treated JSM diet, while feed efficiency was highest (p &gt; 0.05) for those on the 10 % treated JSM diets. Weight gain was significantly highest (p&lt; 0.05) for the rats on 10 and 15 % treated JSM diets. Lowest survival rate (17%) was observed on treated JSM diet processed by boiling, roasting followed by fermenting. Biochemical indices measured on treated JSM based diets were comparable with those obtained on the conventional diet (p &gt; 0.05) except for blood cholesterol level (p &lt; 0.05) which was elevated with increasing treated JSM in diets. There were also no significant differences recorded on AST and ALP activities (p &gt; 0.05) between the treatments. Haematological indices investigated including PCV, RBC, Hb were insignificantly influenced by the 5% dietary treated JSM compared with the control diet (p &gt; 0.05) and there was non-significant effect of the dietary treatment on the WBC differential counts of lymphocytes, eosinophils, monocytes and neutrophils. It was established in this study that inclusion of 5% treated JSM in diets had no detrimental effect on albino rats. Further researches are in progress to investigate inclusion of the treated JSM in diets at levels higher than the 5% used in this study.Keywords: JSM, Cockerels, Performance, Biochemical and haematological parameter