Evaluation of Critical Control Points (CCPS) in the Production of ‘Daddawa’ (African Locust Bean Cake) in Dawakin –Tofa Local Government area, Kano State, Nigeria

Hazard analysis and critical control point (HACCP) was carried out during the production of African locust bean seeds condiment (Daddawa) in a location that specialized in it’s manufacturing namely Kwanar – yandaddawa (Dawakin – Tofa Local Government Area) Kano State, Nigeria. The analyses consisted of determination of the aerobic, anaerobic mesophilic bacterial, staphylococcal and fungal counts. In addition, detection of E. coli 0157: H7, Staphylococcus aureus and Clostridium perfringens on the raw seeds before processing and the processed daddawa were also carried out. The raw seeds, processed seeds, production stages and additives had high total microbial count in the range of 109 - 1011cfu/g, which is above the maximum acceptable limit of 105cfu/g. Bacteria isolated and biochemically characterized were Staphylococcus spp, Clostridium perfringens and E. coli 0157: H7. Mucor and Rhizopus were the fungal genera frequently isolated from most of the samples with Aspergillus fumigatus least isolated. Clostridium botulinum was not isolated at Kwanar yandaddawa. The raw seeds, sand used in dehauling, diluents, pawpaw leaves used as additives as well as final molding, comparing (tabletting) and display for sale to consumers are therefore regarded as a critical control points.Keywords: Aerobes, anaerobes, E. coli 0157: H7, Critical Control Points

Correlation of axial length and corneal power with refractive status of patients with refractive error in Kano, North-Western Nigeria

Background: Uncorrected refractive errors are a major cause of blindness and low vision. Determination of the etiology is essential in planning appropriate treatment modalities. Aim of this study was to determine the correlation between axial length and corneal power with refractive status of patients with refractive error in Kano, Nigeria. Methods: Observational cross-sectional study in which 385 eligible patients were recruited. Relevant history was obtained from the patients and ocular examination was done. Objective and Subjective refraction were performed. Spherical equivalent was calculated for patients with astigmatism. Keratometric readings (k1 and k2) and measurement of axial length were taken. Data was analyzed using the statistical package for the social sciences (SPSS) version 22. Results: Statistically significant inverse association (r=-1.7, r2=56.8%, p<0.0001) was found between Spherical equivalent objective refraction and axial length of right eye. Statistically significant inverse association (r=-1.2, r2=53.3%, p<0.0001) was found between Spherical equivalent subjective refraction and axial length of right eye. Statistically significant inverse association (r=-0.5, r2=8.5%, p<0.0001) was found between spherical equivalent objective refraction and corneal power of the right eye. Statistically significant inverse association (r=-0.3, r2=6.4%, p<0.0001) was found between spherical equivalent subjective refraction and Corneal power of right eye. Negative correlation   existed between axial length and corneal power but was not statistically significant (r=-0.0, p<0.4). Conclusions: The study established that axial length and corneal power are the determinants of refractive status and that axial length is a stronger determinant

Analytic calculation of nonadiabatic transition probabilities from monodromy of differential equations

The nonadiabatic transition probabilities in the two-level systems are calculated analytically by using the monodromy matrix determining the global feature of the underlying differential equation. We study the time-dependent 2x2 Hamiltonian with the tanh-type plus sech-type energy difference and with constant off-diagonal elements as an example to show the efficiency of the monodromy approach. The application of this method to multi-level systems is also discussed.Comment: 13 pages, 2 figure

Steering of a Bosonic Mode with a Double Quantum Dot

We investigate the transport and coherence properties of a double quantum dot coupled to a single damped boson mode. Our numerically results reveal how the properties of the boson distribution can be steered by altering parameters of the electronic system such as the energy difference between the dots. Quadrature amplitude variances and the Wigner function are employed to illustrate how the state of the boson mode can be controlled by a stationary electron current through the dots.Comment: 10 pages, 6 figures, to appear in Phys. Rev.

Environmental contribution to antimicrobial resistance: A largely ignored global health issue

Environmental contribution to the continued occurrence of antibiotic resistance has been largely unexplored. There has been much focus on clinical isolates for their resistant nature but non-clinical bacterial isolates in the environment have been considered as the chief contributing factors that facilitate the spread and dissemination of antibiotic-resistant bacteria (ABR) and antibiotic-resistant genes (ARGs). The natural environment acts as a reservoir for bacteria, providing them with a favourable condition for their emergence and breeding of resistance. One such environmental leverage is inter/intra-specie exchange of genes encoding resistance factors. It was argued that human activities aid immensely in the emergence of antibiotic resistance in the environment. The rationale for this review is to examine extensively the complex interplay of antibiotic resistance from the natural environmental perspective and factors that influence the occurrence and dissemination of such resistance. It also seeks to stress the biological factors that facilitate the emergence of resistance and link it to general biological processes. The review has been structured to capture the general threat posed by the circulation of antibiotic-resistant bacteria and their genes, as well as the influence of the environment in contributing to this global health threat. In addition, the review looked at the effective methods used to tackle the silent pandemic, by controlling the spread of resistance in the environment. Environmental stakeholders and policymakers are recommended to be included in tackling the development of antibiotic resistance

Quantum dynamics in strong fluctuating fields

A large number of multifaceted quantum transport processes in molecular systems and physical nanosystems can be treated in terms of quantum relaxation processes which couple to one or several fluctuating environments. A thermal equilibrium environment can conveniently be modelled by a thermal bath of harmonic oscillators. An archetype situation provides a two-state dissipative quantum dynamics, commonly known under the label of a spin-boson dynamics. An interesting and nontrivial physical situation emerges, however, when the quantum dynamics evolves far away from thermal equilibrium. This occurs, for example, when a charge transferring medium possesses nonequilibrium degrees of freedom, or when a strong time-dependent control field is applied externally. Accordingly, certain parameters of underlying quantum subsystem acquire stochastic character. Herein, we review the general theoretical framework which is based on the method of projector operators, yielding the quantum master equations for systems that are exposed to strong external fields. This allows one to investigate on a common basis the influence of nonequilibrium fluctuations and periodic electrical fields on quantum transport processes. Most importantly, such strong fluctuating fields induce a whole variety of nonlinear and nonequilibrium phenomena. A characteristic feature of such dynamics is the absence of thermal (quantum) detailed balance.Comment: review article, Advances in Physics (2005), in pres

The deuteron: structure and form factors

A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

Structure of the Nucleotide Radical Formed during Reaction of CDP/TTP with the E441Q-α2β2 of E. coli Ribonucleotide Reductase

The Escherichia coli ribonucleotide reductase (RNR) catalyzes the conversion of nucleoside diphosphates to deoxynucleotides and requires a diferric-tyrosyl radical cofactor for catalysis. RNR is composed of a 1:1 complex of two homodimeric subunits: α and β. Incubation of the E441Q-α mutant RNR with substrate CDP and allosteric effector TTP results in loss of the tyrosyl radical and formation of two new radicals on the 200 ms to min time scale. The first radical was previously established by stopped flow UV/vis spectroscopy and pulsed high field EPR spectroscopy to be a disulfide radical anion. The second radical was proposed to be a 4′-radical of a 3′-keto-2′-deoxycytidine 5′-diphosphate. To identify the structure of the nucleotide radical [1′-[superscript 2]H], [2′-[superscript 2]H], [4′-[superscript 2]H], [5′-[superscript 2]H], [U−[superscript 13]C, [superscript 15]N], [U−[superscript 15]N], and [5,6 -[superscript 2]H] CDP and [β-[superscript 2]H] cysteine-α were synthesized and incubated with E441Q-α2β2 and TTP. The nucleotide radical was examined by 9 GHz and 140 GHz pulsed EPR spectroscopy and 35 GHz ENDOR spectroscopy. Substitution of [superscript 2]H at C4′ and C1′ altered the observed hyperfine interactions of the nucleotide radical and established that the observed structure was not that predicted. DFT calculations (B3LYP/IGLO-III/B3LYP/TZVP) were carried out in an effort to recapitulate the spectroscopic observations and lead to a new structure consistent with all of the experimental data. The results indicate, unexpectedly, that the radical is a semidione nucleotide radical of cytidine 5′-diphosphate. The relationship of this radical to the disulfide radical anion is discussed.National Institutes of Health (U.S.) (GM29595)(EB002804)(EB002026