Super-harmonic injection locking of nano-contact spin-torque vortex oscillators

Super-harmonic injection locking of single nano-contact (NC) spin-torque vortex oscillators (STVOs) subject to a small microwave current has been explored. Frequency locking was observed up to the fourth harmonic of the STVO fundamental frequency $f_{0}$ in microwave magneto-electronic measurements. The large frequency tunability of the STVO with respect to $f_{0}$ allowed the device to be locked to multiple sub-harmonics of the microwave frequency $f_{RF}$, or to the same sub-harmonic over a wide range of $f_{RF}$ by tuning the DC current. In general, analysis of the locking range, linewidth, and amplitude showed that the locking efficiency decreased as the harmonic number increased, as expected for harmonic synchronization of a non-linear oscillator. Time-resolved scanning Kerr microscopy (TRSKM) revealed significant differences in the spatial character of the magnetization dynamics of states locked to the fundamental and harmonic frequencies, suggesting significant differences in the core trajectories within the same device. Super-harmonic injection locking of a NC-STVO may open up possibilities for devices such as nanoscale frequency dividers, while differences in the core trajectory may allow mutual synchronisation to be achieved in multi-oscillator networks by tuning the spatial character of the dynamics within shared magnetic layers.Comment: 21 pages, 8 figure

Direct observation of magnetization dynamics generated by nano-contact spin-torque vortex oscillators

Time-resolved scanning Kerr microscopy has been used to directly image the magnetization dynamics of nano-contact (NC) spin-torque vortex oscillators (STVOs) when phase-locked to an injected microwave (RF) current. The Kerr images reveal free layer magnetization dynamics that extend outside the NC footprint, where they cannot be detected electrically, but which are crucial to phase-lock STVOs that share common magnetic layers. For a single NC, dynamics were observed not only when the STVO frequency was fully locked to that of the RF current, but also for a partially locked state characterized by periodic changes in the core trajectory at the RF frequency. For a pair of NCs, images reveal the spatial character of dynamics that electrical measurements show to have enhanced amplitude and reduced linewidth. Insight gained from these images may improve understanding of the conditions required for mutual phase-locking of multiple STVOs, and hence enhanced microwave power emission.Comment: 10 pages, 3 figure

GIS AND BIM INTEGRATION AT DATA LEVEL: A REVIEW

City Geography Markup Language (CityGML) and Industry Foundation Class (IFC) are the two most popular data exchange format for the integration of Geographic Information System (GIS) and Building Information Modelling (BIM) respectively and has been identified by many researchers as an auspicious means of data interoperability between the two domains but with challenges on the compatibility between them. The main issue is the data loss in the process of information transformation. The success of integrating these two domains (GIS and BIM objects) is a great achievement toward solving problems in Architecture, Engineering and Construction (AEC), Facility Management (FM), Disaster Management (DM) sectors. Nevertheless, as we all know GIS and BIM are different fields used by different professionals using different software packages, used for different purposes, it is definitely face with many challenges including data interoperability, mismatch and loss of semantic information are bound to occur during the process of integration. In order to comprehend the two domains and their data models of CityGML and IFC. This paper review existing models on GIS and BIM developed by different researchers, the complementarity and compatibility of GIS and BIM on the previous integration techniques were also reviewed and finally, the paper review the integration of GIS and BIM at the data level aimed at solving different problems surrounding it by considering the transformation of coordinates at geometric level from CityGML to IFC, in order to achieve flow of information between GIS and BIM

Serological evaluation of protective immunity against tetanus in pregnant women attending some rural hospitals in Kano state, northern Nigeria

A study on serological evaluation of protective immunity in pregnant women against tetanus was conducted in two rural hospitals in Kano State, northern Nigeria using immuno-electrophoresis and indirect haemmagglutination techniques. A total of sixty (thirty from each hospital) pregnant women (aged 11-45 years) were used to assess their level of protection against tetanus. Details on client’s age, socio-economic status and number of tetanus toxoid injections received during antenatal visits were obtained using structured questionnaire method. Blood samples were collected and analysed for serum and anti-tetanus antibodies as well as the total protein content. The titre values obtained were statistically analysed using one-way ANOVA to see the effects of age, socio-economic status and number of tetanus toxoid injections received on the mean percentage and concentration of albumin, Ig-A, Ig-G and the total proteins of the subjects. Results obtained showed that the highest percentage and concentration of serum albumin recorded throughout the study period were 73.05 ± 9.16% and 55.30 ± 4.97 g/dl at Tiga Dam and Gaya General Hospitals respectively. The highest levels of serum Ig-A were 18.50 ± 1.53% and 13.85 ± 1.21 g/dl both at Gaya. Similarly, the highest levels of serum Ig-G were 15.21 ± 25.81% and 11.55 ± 3.57 g/dl both at Gaya while the highest value of the total protein recorded was 80.23 ± 0.83 g/dl at Tiga. Results of the indirect haemmagglutination analysis indicated that the highest and lowest titre values were 1:922 and 1:13 HU/ml respectively. It was generally observed that age, socio-economic status and number of toxoid tetanus injections demonstrated significant (P < 0.05) influence on the levels of serum albumin, Ig-A, Ig-G and the total proteins. Similarly, clients with more than three injections of tetanus toxoid were observed to elicit higher (P < 0.05) antibody response as compared to those who did not receive any injection (P > 0.05)

Microbial contamination of Naira notes circulating in Bauchi metropolis: prevalence, microbial load and detection of extended spectrum beta-lactamase producing Gram-negative bacteria

Background: Globally, contamination of banknotes with various microbial species is increasingly being reported. This usually results from improper handling during exchange of goods and services. In the present study, we aimed to determine the microbial load, prevalence and the presence of Extended Spectrum Beta Lactamase (ESBL) among bacteria isolated from the Nigerian Naira notes circulating in Bauchi metropolis.Methodology: A total of 400 Naira notes of various denominations were randomly collected aseptically, cultured and total viable counts determined. The isolated microbial species were identified using standard microbiological techniques. Antibiotic susceptibility of the isolates and detection of ESBL were determined by Kirby-Bauer’s disc diffusion method and Double Disc Synergy Test (DDST), respectively.Results: All the 400 samples collected were contaminated with various microbial species. The highest mean colony count was detected in 20 Naira notes (28.5%), while the least was observed in 1000 Naira note (3.3%). Fourteen different microbial species were isolated from the contaminated currency notes, predominantly Escherichia coli (25.0%), and Staphylococcus aureus (12.0%). Some fungal species mainly Aspergillus flavus and Aspergillus niger were also isolated. Majority of the bacteria isolates resistant to the third generation cephalosporins (72.1%) were ESBL positive.Conclusion: The study shows that Naira notes circulating in Bauchi metropolis were heavily contaminated with various microbial species, and a high proportion of the isolated Gram-negative bacteria were ESBL producers. Efforts should thus be made to improve hygiene practices in the study area. Importantly, businesses should be encouraged to adopt the use of electronic transactions. Keywords: Currency notes, Naira, Microbial contamination, ESB

WISE colours and star-formation in the host galaxies of radio-loud narrow-line Seyfert 1

We investigate the mid-infrared properties of the largest (42 objects) sample of radio-loud narrow-line Seyfert 1 (RL NLS1) collected to date, using data from the Wide-field Infrared Survey Explorer (WISE). We analyse the mid-IR colours of these objects and compare them to what is expected from different combinations of AGN and galaxy templates. We find that, in general, the host-galaxy emission gives an importan contribution to the observed mid-IR flux in particular at the longest wavelengths (W3, at 12micron, and W4, at 22micron). In about half of the sources (22 objects) we observe a very red mid-IR colour (W4-W3>2.5) that can be explained only using a starburst galaxy template (M82). Using the 22micron luminosities, corrected for the AGN contribution, we have then estimated the star-formation rate for 20 of these "red" RL NLS1, finding values ranging from 10 to 500 Msun/y. For the RL NLS1 showing bluer colours, instead, we cannot exclude the presence of a star-forming host galaxy although, on average, we expect a lower star-formation rate. Studying the radio (1.4GHz) to mid-IR (22micron) flux ratios of the RL NLS1 in the sample we found that in ~10 objects the star-forming activity could represent the most important component also at radio frequencies, in addition (or in alternative) to the relativistic jet. We conclude that both the mid-IR and the radio emission of RL NLS1 are a mixture of different components, including the relativistic jet, the dusty torus and an intense star-forming activity.Comment: Accepted for publication in MNRAS, 11 pages, 7 figures, 2 table

Ribosomal DNA variation in landraces of bambara groundnut

The ribosomal DNA (rDNA) is a basic component of all eukaryotic chromosomes which codes for rRNA. The rDNA is made of tandemly repeated units of 18S, 5.8S, 28S, ITS and IGS. The 18S, 5.8S and 28S are coding regions while the ITS and IGS are non coding. The rDNA evolves in a concerted manner such that rDNA units within an individual are almost completely identical making it a useful tool in taxonomic studies. The rDNA marker is used to discriminate between species in the same or different genus. Bambara groundnut is an under-utilized legume that is highly nutritious and adapted to low input farming systems. Despite its potential, Bambara groundnut is still cultivated in the form of landraces, and no true varieties have been developed. Precise estimate of genetic variation and genetic relationship is sine qua non for the development of improved cultivars. About 48 individual seeds (3 each) from seven landraces of Bambara groundnut, 9 wild/cultivated species of other legumes (cowpea, mungbean and groundnut) were used in this study. Analysis of the rDNA gene unit shows genetic variation in the species of the genus Vigna and Arachis. The UPGMA dendrogram constructed separates the plant species in this study into three (3) main clusters. The landraces of Bambara groundnut were placed in two different clusters indicating variation of rDNA gene units between the landraces. The analysis of rDNA gene in this study reveals the presence of genetic variation between the landraces of Bambara groundnut which could be used by scientists and breeders in the production of improved cultivars.Keywords: Ribosomal DNA, Bambara groundnut, ITS, IGS, DNA variationAfrican Journal of Biotechnology Vol. 12(35), pp. 5395-540

Growth components and Yield of \u3cem\u3eBrachiaria ruziziensis\u3c/em\u3e (Congo grass) and \u3cem\u3eCentrosema pascuorum\u3c/em\u3e (Centro) Mixtures as Influenced by Mixture Ratios, Phosphorus Levels and Stage of Harvest

This study was conducted during the 2017 and 2018 rainy season at the Crop Production Research farm, Abubakar Tafawa Balewa University, Bauchi to determine the effects of plant mixture ratios in Brachiaria ruziziensis and Centrosema pascuorum (100% Sole B. ruziziensis, 75% B.R: 25% C.P, 50% B.R: 50% C.P, 25% B.R: 75% C.P and 100% Sole C. pascuorum) and phosphorus fertilizer (SSP) levels (0, 100 and 150kg/ha). The experiment was in a split-plot design with 5x3 factorial arrangement in which the mixture ratios constituted the main plots while phosphorus (SSP) levels constituted the sub treatments. Number of plants per stand ranged from 6.11 in 25% B.R: 75% C.P to 9.56 in 100% B. ruziziensis and 2.89 in 75% B.R: 25% C.P to 11.11 in 50% B.R: 50% C.P. The highest plant height for B. ruziziensis was obtained in 25% B.R: 75% C.P (38.0). Similarly, 25% B.R: 75% C.P mixture had highest plant height for C. pascuorum (45.11). However, tiller per branch per m2 ranged from 57.60 in 25% B.R: 75% C.P to 190.9 in 100 B. ruziziensis and 32.9 in 75% B.R: 25% C.P to 257.90 in 100 C. pascuorum. The mean values indicated that mixture ratios and phosphorus (SSP) levels significantly (P \u3c 0.05) increased plant height and tiller numbers in B. ruziziensis and C. pascuorum mixtures and 75% B.R: 25% C.P mixture, 150kg/ha Single Super Phosphate fertilization and sampling period at week 8 had the best plant height and tiller per branch

Deductive synthesis of recursive plans in linear logic

Linear logic has previously been shown to be suitable for describing and deductively solving planning problems involving conjunction and disjunction. We introduce a recursively defined datatype and a corresponding induction rule, thereby allowing recursive plans to be synthesised. In order to make explicit the relationship between proofs and plans, we enhance the linear logic deduction rules to handle plans as a form of proof term