Performance data of screening mammography at a dedicated breast health centre

The original publication is available at http://www.samj.org.zaBackground. Mammographic screening has become part of routine health care. We present a first analysis of screening mammography in a dedicated breast health centre in Africa. Objective. To establish a performance benchmark and provide data for health care policy and funding decisions on screening mammography. Method. All mammography performed between January 2003 and August 2008 was entered into a prospective database. Mammography was performed exclusively by certified mammographers and double-read by experienced readers. Results. Outcomes were classified in a simplified classification system based on the Breast Imaging Reporting and Data System (BIRADS). In 40-49-year-old women, 3 192 mammograms led to a recall rate of 4.7%, a biopsy rate of 1.9% and a cancer diagnosis rate of 3.8 per 1000 examinations, for women of 50 years and older, the corresponding figures were 4 446, 5.4%, 2.6% and 9.7 per 1 000. Of the cancers detected, 31% were in situ and, of the invasive cancers, 81% were node-negative. These figures were established by a dedicated surgeon-led team and fall within the range expected in organised screening programmes in resource-rich environments, providing a first benchmark for screening mammography in Africa.Publishers' versio

Measurement of antiacetylcholine receptor auto-antibodies in myasthenia gravis

Two different acetylcholine receptor (AChR) preparations derived from amputated human muscle (AChRAMP) and from the human rhabdomyosarcoma cell line TE671 (AChRTE67,) were compared in radio-immunoprecipitation assays for the detection of AChR auto-antibodies in serum specimens from 20 patients with proven myasthenia gravis. Tests performed with the AChRTE67, and AChRAMP antigen preparations were positive in all the patients and in 19/20 respectively. A high degree of correlation (r = 0,94) was evident between the two auto-antigen preparations. Assays based on the use of TE671-derived antigen represent a useful alternative to the conventional assay using AChRAMP  for the detection of AChR autoantibodies

Private-label use and store loyalty

The authors develop an econometric model of the relationship between a household’s private-label (PL) share and its behavioral store loyalty. The model includes major drivers of these two behaviors and controls for simultaneity and nonlinearity in the relationship between them. The model is estimated with a unique data set that combinescomplete purchase records of a panel of Dutch households with demographic and psychographic data. The authorsestimate the model for two retail chains in the Netherlands the leading service chain with a well-differentiatedhigh-share PL and the leading value chain with a lower-share PL. They find that PL share significantly affects all three measures of behavioral loyalty in the study: share of wallet, share of items purchased, andshare of shopping trips. In addition, behavioral loyalty has a significant effect on PL share. For the service chain, the authors find that both effects are in the form of an inverted U. For the value chain, the effects are positive and nonlinear, but they do not exhibit nonmonotonicity, because PL share has not yet reached high enough levels. The managerial implications of this research are important. Retailers can reap the benefits of a virtuous cycle; greater PL share increases share of wallet, and greater share of wallet increases PL share. However, this virtuous cycle operates only to a point because heavy PL buyers tend to be loyal to price savings and PLs in general, not to the PL of any particular chain.pre-prin

New alk(en)ylhydroxycyclohexanes with tyrosinase inhibition potential from Harpephyllum caffrum Bernh. gum exudate

SUPPLEMENTARY MATERIALS : FIGURE S1 to S36 containing 1D and 2D NMR spectra, FT-IR, ECD spectra and high-resolution mass spectra of compounds 1–4.This work presents the first report on the phytochemical investigation of Harpephyllum caffrum Bernh. gum exudate. A known cardanol, 3-heptadec-120-Z-enyl phenol (1) and three new alk(en)ylhydroxycyclohexanes, namely, (1R,3R)-1,3-dihydroxy-3-[heptadec-120(Z)-enyl]cyclohexane (2) (1S,2S,3S,4S,5R)-1,2,3,4,5-pentahydroxy-5-[octadec-130(Z)-enyl]cyclohexane (3) and (1R,2S,4R)- 1,2,4-trihydroxy-4-[heptadec-120(Z)-enyl]cyclohexane (4) were isolated from the gum. The structures of the compounds were determined by extensive 1D and 2D NMR spectroscopy and HR-ESI-MS data. The ethanolic extract of the gum was found to be the most potent tyrosinase inhibitor with IC50 of 11.32 g/mL while compounds 2 and 3, with IC50 values of 24.90 and 26.99 g/mL, respectively, were found to be potential anti-tyrosinase candidates from the gum. Gum exudate may be a potential source for non-destructive harvesting of selective pharmacologically active compounds from plants. The results also provide evidence that H. caffrum gum may find application in cosmetics as a potential anti-tyrosinase agent.The University of KwaZulu-Natal, University of Johannesburg and University of South Africa.https://www.mdpi.com/journal/moleculesam2023Chemistr

Functional significance may underlie the taxonomic utility of single amino acid substitutions in conserved proteins

We hypothesized that some amino acid substitutions in conserved proteins that are strongly fixed by critical functional roles would show lineage-specific distributions. As an example of an archetypal conserved eukaryotic protein we considered the active site of ß-tubulin. Our analysis identified one amino acid substitution—ß-tubulin F224—which was highly lineage specific. Investigation of ß-tubulin for other phylogenetically restricted amino acids identified several with apparent specificity for well-defined phylogenetic groups. Intriguingly, none showed specificity for “supergroups” other than the unikonts. To understand why, we analysed the ß-tubulin Neighbor-Net and demonstrated a fundamental division between core ß-tubulins (plant-like) and divergent ß-tubulins (animal and fungal). F224 was almost completely restricted to the core ß-tubulins, while divergent ß-tubulins possessed Y224. Thus, our specific example offers insight into the restrictions associated with the co-evolution of ß-tubulin during the radiation of eukaryotes, underlining a fundamental dichotomy between F-type, core ß-tubulins and Y-type, divergent ß-tubulins. More broadly our study provides proof of principle for the taxonomic utility of critical amino acids in the active sites of conserved proteins

Multiattribute perceptual mapping with idiosyncratic brand and attribute sets

This article proposes an extremely flexible procedure for perceptual mapping based on multiattribute ratings, such that the respondent freely generates sets of both brands and attributes. Therefore, the brands and attributes are known and relevant to each participant. Collecting and analyzing such idiosyncratic datasets can be challenging. Therefore, this study proposes a modification of generalized canonical correlation analysis to support the analysis of the complex data structure. The model results in a common perceptual map with subject-specific and overall fit measures. An experimental study compares the proposed procedure with alternative approaches using predetermined sets of brands and/or attributes. In the proposed procedure, brands are better known, attributes appear more relevant, and the respondent's burden is lower. The positions of brands in the new perceptual map differ from those obtained when using fixed brand sets. Moreover, the new procedure typically yields positioning information on more brands. An empirical study on positioning of shoe stores illustrates our procedure and resulting insights. Finally, the authors discuss limitations, potential application areas, and directions for research

Customer’s Acceptance of Humanoid Robots in Services: The Moderating Role of Risk Aversion

The emerging introduction of humanoid robots in service encounters is becoming a reality in the present and the short-term. Owing to this unstoppable advance, there is a need to better understand customers’ perceptions and reactions toward humanoid agents in service encounters. To shed some light on this underexplored phenomenon, this research investigates how the interaction between robot and customer’s features may contribute to a successful introduction of this disruptive innovation. Results of an empirical study with a sample of 168 US customers reveal that customer’s perceptions of robot’s human-likeness increase the intentions to use humanoid service robots. Interestingly, customers’ risk aversion moderates this relationship. Specifically, the study found that highly risk-averse customers tend to avoid using humanoids when they are perceived as highly mechanical-like. The discussion highlights the main contributions of the research, which combine previous knowledge on human–robot interaction and risk aversion from a marketing approach. Managerial implications derived from the research findings and the avenues opened for further research are described at the end

First detection of a VHE gamma-ray spectral maximum from a Cosmic source: H.E.S.S. discovery of the Vela X nebula

The Vela supernova remnant (SNR) is a complex region containing a number of sources of non-thermal radiation. The inner section of this SNR, within 2 degrees of the pulsar PSR B0833-45, has been observed by the H.E.S.S. gamma-ray atmospheric Cherenkov detector in 2004 and 2005. A strong signal is seen from an extended region to the south of the pulsar, within an integration region of radius 0.8 deg. around the position (RA = 08h 35m 00s, dec = -45 deg. 36' J2000.0). The excess coincides with a region of hard X-ray emission seen by the ROSAT and ASCA satellites. The observed energy spectrum of the source between 550 GeV and 65 TeV is well fit by a power law function with photon index = 1.45 +/- 0.09(stat) +/- 0.2(sys) and an exponential cutoff at an energy of 13.8 +/- 2.3(stat) +/- 4.1(sys) TeV. The integral flux above 1 TeV is (1.28 +/- 0.17 (stat) +/- 0.38(sys)) x 10^{-11} cm^{-2} s^{-1}. This result is the first clear measurement of a peak in the spectral energy distribution from a VHE gamma-ray source, likely related to inverse Compton emission. A fit of an Inverse Compton model to the H.E.S.S. spectral energy distribution gives a total energy in non-thermal electrons of ~2 x 10^{45} erg between 5 TeV and 100 TeV, assuming a distance of 290 parsec to the pulsar. The best fit electron power law index is 2.0, with a spectral break at 67 TeV.Comment: 5 pages, 4 figures, accepted for publication in Astronomy and Astrophysics letter

Observations of Mkn 421 in 2004 with H.E.S.S. at large zenith angles

Mkn 421 was observed during a high flux state for nine nights in April and May 2004 with the fully operational High Energy Stereoscopic System (H.E.S.S.) in Namibia. The observations were carried out at zenith angles of 60$^\circ$--65$^\circ$, which result in an average energy threshold of 1.5 TeV and a collection area reaching 2~km$^2$ at 10~TeV. Roughly 7000 photons from Mkn~421 were accumulated with an average gamma-ray rate of 8 photons/min. The overall significance of the detection exceeds 100 standard deviations. The light-curve of integrated fluxes above 2~TeV shows changes of the diurnal flux up to a factor of 4.3. For nights of high flux, intra-night variability is detected with a decay time of less than 1 hour. The time averaged energy spectrum is curved and is well described by a power-law with a photon index \egamm and an exponential cutoff at \ecut~TeV and an average integral flux above 2~TeV of 3 Crab flux units. Significant variations of the spectral shape are detected with a spectral hardening as the flux increases. Contemporaneous multi-wavelength observations at lower energies (X-rays and gamma-rays above $\approx 300$~GeV) indicate smaller relative variability amplitudes than seen above 2~TeV during high flux state observed in April 2004.Comment: 5 pages, 4 figures, published in A&

Very high energy gamma rays from the direction of Sagittarius A*.

We report the detection of a point-like source of very high energy (VHE) -rays coincident within 1' of Sgr A *, obtained with the HESS array of Cherenkov telescopes. The -rays exhibit a power-law energy spectrum with a spectral index of and a flux above the 165 GeV threshold of m -2 s -1. The measured flux and spectrum differ substantially from recent results reported in particular by the CANGAROO collaboration