Tunneling of a Quantized Vortex: Roles of Pinning and Dissipation

We have performed a theoretical study of the effects of pinning potential and dissipation on vortex tunneling in superconductors. Analytical results are obtained in various limits relevant to experiment. In general we have found that pinning and dissipation tend to suppress the effect of the vortex velocity dependent part of the Magnus force on vortex tunneling.Comment: Latex, 12 page

Nanodelivery of a functional membrane receptor to manipulate cellular phenotype.

Modification of membrane receptor makeup is one of the most efficient ways to control input-output signals but is usually achieved by expressing DNA or RNA-encoded proteins or by using other genome-editing methods, which can be technically challenging and produce unwanted side effects. Here we develop and validate a nanodelivery approach to transfer in vitro synthesized, functional membrane receptors into the plasma membrane of living cells. Using β2-adrenergic receptor (β2AR), a prototypical G-protein coupled receptor, as an example, we demonstrated efficient incorporation of a full-length β2AR into a variety of mammalian cells, which imparts pharmacologic control over cellular signaling and affects cellular phenotype in an ex-vivo wound-healing model. Our approach for nanodelivery of functional membrane receptors expands the current toolkit for DNA and RNA-free manipulation of cellular function. We expect this approach to be readily applicable to the synthesis and nanodelivery of other types of GPCRs and membrane receptors, opening new doors for therapeutic development at the intersection between synthetic biology and nanomedicine

Improving Employability Skills Through a Web-Based Work Integrated Learning Database for Construction Students

Employability and Unemployment continues to be dire issues that Nigerian youth are faced with daily in a saturated employment market. Whereas, the use of workintegrated learning can help bridge the gap by increasing employability skills among students. The study examined the benefits of having a work-integrated learning (WIL) program for students in the construction field. Therefore, the study developed a framework for improving employability skills through a web-based work integrated learning database for construction students. Using a system block diagram, use case diagram and activity diagram, the study illustrated the functional requirement needed for the development of the WIL platform. The WIL platform is a web-based system pooling submission of available WIL positions from employers in construction businesses and former WIL students in order for prospective WIL students to access possible openings where they can learn in a workplace environment. The methodology of this research includes using the combination of HTML, CSS and the C-Sharp programming language for the interface design and server side scripting while MySQL was the database platform used for storing and retrieving the data used for the application. In conclusion, the study designed a WIL platform for construction students. The use of the WIL platform is intended to encourage employability of construction students by ensuring that they are adequately engaged in a work place training

The thermal state of molecular clouds in the Galactic Center: evidence for non-photon-driven heating

We used the Atacama Pathfinder Experiment (APEX) 12 m telescope to observe the J_KaKc=3_03-2_02, 3_22-2_21, and 3_21-2_20 transitions of para-H_2CO at 218 GHz simultaneously to determine kinetic temperatures of the dense gas in the central molecular zone (CMZ) of our Galaxy. The map extends over approximately 40 arcmin x 8 arcmin (~100x20 pc^2) along the Galactic plane with a linear resolution of 1.2 pc. The strongest of the three lines, the H_2CO (3_03-2_02) transition, is found to be widespread, and its emission shows a spatial distribution similar to ammonia. The relative abundance of para-H_2CO is 0.5-1.2 10^{-9}, which is consistent with results from lower frequency H_2CO absorption lines. Derived gas kinetic temperatures for individual molecular clouds range from 50 K to values in excess of 100 K. While a systematic trend toward (decreasing) kinetic temperature versus (increasing) angular distance from the Galactic center (GC) is not found, the clouds with highest temperature (T_kin > 100 K) are all located near the nucleus. For the molecular gas outside the dense clouds, the average kinetic temperature is 65+/-10 K. The high temperatures of molecular clouds on large scales in the GC region may be driven by turbulent energy dissipation and/or cosmic-rays instead of photons. Such a non-photon-driven thermal state of the molecular gas provides an excellent template for the more distant vigorous starbursts found in ultraluminous infrared galaxies (ULIRGs).Comment: 23 pages, 11 figures, A&A in pres

What Powers Lyman alpha Blobs?

Lyman alpha blobs (LABs) are spatially extended lyman alpha nebulae seen at high redshift. The origin of Lyman alpha emission in the LABs is still unclear and under debate. To study their heating mechanism(s), we present Australia Telescope Compact Array (ATCA) observations of the 20 cm radio emission and Herschel PACS and SPIRE measurements of the far-infrared (FIR) emission towards the four LABs in the protocluster J2143-4423 at z=2.38. Among the four LABs, B6 and B7 are detected in the radio with fluxes of 67+/-17 microJy and 77+/-16 microJy, respectively, and B5 is marginally detected at 3 sigma (51+/-16 microJy). For all detected sources, their radio positions are consistent with the central positions of the LABs. B6 and B7 are obviously also detected in the FIR. By fitting the data with different templates, we obtained redshifts of 2.20$^{+0.30}_{-0.35}$ for B6 and 2.20$^{+0.45}_{-0.30}$ for B7 which are consistent with the redshift of the lyman alpha emission within uncertainties, indicating that both FIR sources are likely associated with the LABs. The associated FIR emission in B6 and B7 and high star formation rates strongly favor star formation in galaxies as an important powering source for the lyman alpha emission in both LABs. However, the other two, B1 and B5, are predominantly driven by the active galactic nuclei or other sources of energy still to be specified, but not mainly by star formation. In general, the LABs are powered by quite diverse sources of energy.Comment: 7 pages and 3 figurs, accepted by A&

Calcifying epithelial odontogenic tumour-case series from five Nigerian Teaching Hospital

Background: Calcifying epithelial odontogenic tumour (CEOT) also known as Pindborg’s tumour is a relatively rare odontogenic neoplasm of epithelial derivationthat constitutes about 0.4-3% of all intraosseous odontogenic tumours.Objectives: To document all cases of CEOT encountered in five tertiary centres in Nigeria and their clinical, radiologic and histologic characteristics.Design: A retrospective study.Setting: Tertiary Dental Facilities in Lagos, Ibadan, Ife, Port Harcourt and Zaria (all in Nigeria) were involved in the study.Subjects: All odontogenic tumours (OTs) in the period from 1970 -2014. Case file records and biopsy reports were retrieved from the records of the five Teaching Hospitals, to obtain age, gender, location, size, clinical symptoms, pathological reports and radiographic description.Results: Out of a total of 1369 OTs, 20 (1.5%) cases of CEOT were reported. CEOT had a male to female ratio of 1.9:1, with mandible: maxilla ratio of 1.5:1 and the most common location being the premolar /molar region in the mandible. Nine (45%) cases appeared radiolucent while 11(55%) cases had mixed radio density. The mean diameter for mixed radio-dense lesions (4.83±2.99) was higher than that for radiolucent lesions (2.75±1.17) and the difference was statistically significant (p=0.049).Conclusion: CEOT is a rare tumour representing 1.5% of OTs. CEOT presents with some subtle geographic differences in its demography, however, further studies are required to investigate if these differences are coincidental or genetically  determined

Avascular necrosis in sickle cell (homozygous S) patients: Predictive clinical and laboratory indices

Background: Pathogenetic mechanism as well as laboratory and clinical correlates of osteonecrosis in sickle cell have not been fully investigated. The aim of this study is to investigate the predictive value of the steady state white cell and platelet count as well as the frequency of bone pain crisis per annum to detect sickle cell patients who will eventually develop avascular necrosis (AVN).Patients and Methods: A 5 year retrospective analysis of 122 homozygous S (HbSS) patients, aged 6‑49 years (mean age 24.7 ± 7 years), out of which 16 patients (13.1%) had developed AVN within the years under review.Results: The prevalence of AVN in sickle cell patients was determined to be 13.1 per 1000. The steady state white cell count, platelet count, frequency of bone pain crisis and hematocrit, was compared in patients that develop AVN and those who had not over the period. Only the steady state platelet count was found to differ significantly (P = 0.011) between these two patient groups and to correlate positively (Pearson correlation coefficient = −0.251) with development of AVN. The hematocrit, white cell count, and frequency of bone pain crisis were found neither to differ significantly nor correlate with the development of AVN.Conclusion: In conclusion, patients with a raised steady state platelet count may have a higher tendency to develop AVN and may require closer orthopedic review and prophylactic intervention.Key words: Avascular necrosis, homozygous S, platelet count, sickle cell anemia, white cell coun

Heat flux operator, current conservation and the formal Fourier's law

By revisiting previous definitions of the heat current operator, we show that one can define a heat current operator that satisfies the continuity equation for a general Hamiltonian in one dimension. This expression is useful for studying electronic, phononic and photonic energy flow in linear systems and in hybrid structures. The definition allows us to deduce the necessary conditions that result in current conservation for general-statistics systems. The discrete form of the Fourier's Law of heat conduction naturally emerges in the present definition