On the Optical -- X-ray correlation from outburst to quiescence in Low Mass X-ray Binaries: the representative cases of V404 Cyg and Cen X-4

Low mass X-ray binaries (LMXBs) show evidence of a global correlation of debated origin between X-ray and optical luminosity. We study for the first time this correlation in two transient LMXBs, the black hole V404 Cyg and the neutron star Cen X-4, over 6 orders of magnitude in X-ray luminosity, from outburst to quiescence. After subtracting the contribution from the companion star, the Cen X-4 data can be described by a single power law correlation of the form $L_{opt}\propto\,L_{X}^{0.44}$, consistent with disk reprocessing. We find a similar correlation slope for V404 Cyg in quiescence (0.46) and a steeper one (0.56) in the outburst hard state of 1989. However, V404 Cyg is about $160-280$ times optically brighter, at a given $3-9$ keV X-ray luminosity, compared to Cen X-4. This ratio is a factor of 10 smaller in quiescence, where the normalization of the V404 Cyg correlation also changes. We show that once the bolometric X-ray emission is considered and the known main differences between V404 Cyg and Cen X-4 are taken into account (a larger compact object mass, accretion disk size, and the presence of a strong jet contribution in the hard state for the black hole system) the two systems lie on the same correlation. In V404 Cyg, the jet dominates spectrally at optical-infrared frequencies during the hard state, but makes a negligible contribution in quiescence, which may account for the change in its correlation slope and normalization. These results provide a benchmark to compare with data from the 2015 outburst of V404 Cyg and, potentially, other transient LMXBs as well.Comment: Accepted on ApJ, 12 pages, 4 figures, 4 table

Brief inactivation of c-Myc is not sufficient for sustained regression of c-Myc-induced tumours of pancreatic islets and skin epidermis

Background Tumour regression observed in many conditional mouse models following oncogene inactivation provides the impetus to develop, and a platform to preclinically evaluate, novel therapeutics to inactivate specific oncogenes. Inactivating single oncogenes, such as c-Myc, can reverse even advanced tumours. Intriguingly, transient c-Myc inactivation proved sufficient for sustained osteosarcoma regression; the resulting osteocyte differentiation potentially explaining loss of c-Myc's oncogenic properties. But would this apply to other tumours? Results We show that brief inactivation of c-Myc does not sustain tumour regression in two distinct tissue types; tumour cells in pancreatic islets and skin epidermis continue to avoid apoptosis after c-Myc reactivation, by virtue of Bcl-xL over-expression or a favourable microenvironment, respectively. Moreover, tumours progress despite reacquiring a differentiated phenotype and partial loss of vasculature during c-Myc inactivation. Interestingly, reactivating c-Myc in β-cell tumours appears to result not only in further growth of the tumour, but also re-expansion of the accompanying angiogenesis and more pronounced β-cell invasion (adenocarcinoma). Conclusions Given that transient c-Myc inactivation could under some circumstances produce sustained tumour regression, the possible application of this potentially less toxic strategy in treating other tumours has been suggested. We show that brief inactivation of c-Myc fails to sustain tumour regression in two distinct models of tumourigenesis: pancreatic islets and skin epidermis. These findings challenge the potential for cancer therapies aimed at transient oncogene inactivation, at least under those circumstances where tumour cell differentiation and alteration of epigenetic context fail to reinstate apoptosis. Together, these results suggest that treatment schedules will need to be informed by knowledge of the molecular basis and environmental context of any given cancer

Helicobacter pylori Infection: Antibiotic Resistance and Solutions for Effective Management in Africa

Helicobacter pylori. pylori infection is ubiquitous worldwide, with prevalence rates of greater than 70% in Africa. Symptomatic patients present with foregut gastrointestinal symptoms which can be readily diagnosed with standardized non-invasive or invasive tests. The biggest challenge, however, is in the management of this condition with rising antimicrobial resistance rates to most of the antibiotics recommended for therapy. This is a problem worldwide, but more specifically in Africa, where the socio-economic and political climate is such that eradication of this organism seems impossible. Furthermore, the recommended antimicrobial susceptibility testing for drug resistance is not widely available in Africa due to the lack of infrastructural as well as human resources. With the widespread unregulated use of antibiotics in some parts of Africa, the figures of antimicrobial resistance are likely to soar. In the face of these significant challenges, this ‘perspectives’ article aims to address the issue of antimicrobial resistance in Africa, by providing achievable and targeted goals to curb the spread of infection and rising antimicrobial resistance

Economic Analysis of the Impact of Labour Unionist Activities on Educational Stability in Nigerian Universities

This paper analyzes the Labour Unionist activities of Academic Staff Union of Nigerian Universities (ASUU) and Senior Staff Association of Nigerian Universities (SSANU) in Nigerian Universities pre and post year 2000. It presents total number and duration of strike activities and their impact on worker productivity and educational stability in Nigerian Universities. Four null hypotheses were formulated to guide the study. Time series data are collected through archival sources. These were presented in tables and analyzed using t test statistics and regression analysis.. Results revealed that strike activities have been a frequent occurrence in the Nigerian educational milieu. Significant differences were discovered to exist in the duration and impact of strike activities by SSANU and ASUU pre and post year 2000. Principal component analysis was also done to find out which of the causative strike factors were most pressing. It was discovered that the most pressing ones were conflict between labour unions in Universities, poor implementation of agreements by governments, patronage of university consultancy services by governments and reduction of the role of JAMB in undergraduate admission. Some of the recommendations include frequent dialogue between government, University administration and employers and worker conditions of service be reviewed to match inflationary tendencies. Keywords: Labour unionism, Strikes, Educational stability, Man hour los

Genetic evaluation for goat breeds Saanen and Alpine Camosciata: Total Merit Index

The difficulty to select breeding animals on the base of 5 separate indices (yield of milk, fat and protein and corresponding percentages) made it necessary to simplify the process by combining sep..

Pengetahuan Bidan Tentang Komunikasi Terapeutik Dalam Praktik Kebidanan

Latar Belakang: Komunikasi terapeutik kurang menjadi fokus para bidan karena para bidan lebih mementingkan pelayanan daripada praktik penyembuhan. Selain itu, juga tidak melakukan komunikasi terapeutik dan hanya melakukan tugasnya sesuai dengan pengalaman mereka.Tujuan: Mengetahui gambaran tingkat pengetahuan bidan tentang komunikasi terapeutik di puskesmas rawat inap wilayah Yogyakarta.Metode: Penelitian ini merupakan penelitian deskriptif analitik dengan pendekatan cross sectional. Populasi pada penelitian ini sebanyak 32 orang dan sampelnya sebanyak 32 orang dengan metode total sampling. Instrumen penelitian berupa kuesioner tertutup. Metode analisa data menggunakan statistika deskriptif distribusi frekuensi.Hasil: Pengetahuan bidan tentang pengertian komunikasi terapeutikdalam kategori cukup (75%), pengetahuan tentang tujuan dan prinsip komunikasi terapeutik dalam kategori cukup (46,9%), dan pengetahuan tentang teknik komunikasi terapeutikdalam kategori cukup (75%).Kesimpulan: Pengetahuan bidan di puskesmas rawat inap wilayah Yogyakarta tentang komunikasi terapeutik sebagian besar dalam kategori cukup