Rail commuter service quality in South Africa : results from a longitudinal study

Abstract: Rail transport is a critical mass transit mode in South Africa performing in excess of 400 million passenger trips per annum. Within a high density metropolitan region it is expected that rail passenger transport form the backbone of the public transport system, however in the Gauteng region it is estimated that only 8% of public transport commuting trips are completed by train; approximately 2% of total commuting trip. Total rail passenger trips have declined by nearly 20% since 2013/14. This suggests that the passenger rail service provider, PRASA, is not providing the service levels that commuters require. If rail is to fulfil its expected role, it is crucial that service levels are improved. The 2014 Gauteng Household Travel Survey suggests that train users were generally dissatisfied with train services, citing availability, overcrowding on trains, punctuality and reliability of services, geographical coverage and frequencies of services as key limitations. To more accurately assess the extent of service dissatisfaction, this research applied an adapted SERVQUAL model to determine the gap between commuters’ perceptions of service quality and their expectations. The study utilised a longitudinal approach to determine whether customer perceptions of five dimensions of service quality, i.e. reliability, the extent of the service, comfort, safety and affordability had changed over a two-year period. The results indicate changing gaps in most of the dimensions and a number of attributes were identified as having influenced the perception of service quality significantly enough to lead to customer dissatisfaction

Service quality expectations of online grocery consumers in Gauteng, South Africa

Abstract: The remarkable global growth in the online retail market has resulted in many challenges for online grocery retailers. The emerging South African online grocery market is faced with unique last-mile logistical challenges. This article identifies the main service quality expectations of South African online grocery consumers and provides online grocery retailers with an improved understanding of their consumers’ service requirements and enables them to formulate and implement effective last-mile logistics strategies. This research utilises a quantitative research design and used primary data, obtained through self-administered online questionnaires. The research shows that attended home/work delivery was rated the consumers’ most preferred last-mile delivery option and that the delivery option does affect consumers’ final decision to purchase groceries online. Respondents clearly indicated delivery costs as the most important factor when selecting a delivery service. Although the research findings indicate that South African consumers are still not very confident about buying groceries online, the various factors identified provide opportunities for retailers to exploit possible market opportunities to build consumers’ confidence whilst increasing their market share

Serum prostate-specific antigen as surrogate for the Histological diagnosis of Prostate cancer

Introduction. To determine whether there is a cut-off value of serum prostate-specific antigen (PSA) which can be used confidently to make the diagnosis of prostate cancer, thereby obviating the need for biopsy.Patients and methods. During the period October 1991 to March 1998 the Department of Chemical Pathology at Tygerberg Hospital performed a total of 6 733 serum PSA assays on 3960 patients. The histopathological and clinical diagnoses of these patients were obtained from records in the departments of Anatomical Pathology, Urological Oncology and Radiation Oncology. The serum PSA levels were correlated with the histopathology reports, using different PSA cut-off values ranging from 5 to 500 ng/ ml, to calculate the sensitivity, specificity, and positive and negative predictive values of each cut-off value of PSA in predicting the presence of prostate cancer.Results. In total, 3 837 (57%) of the 6 733 serum PSA assays were ≤ 4 ng/ ml, 1 045 (15.5%) of the assays were ≥50 ng/ ml, and 798 (11.9%) were~ 100 ng/ ml. Of the total of 3 960 individual patients, 531 (13.4%) had a serum PSA ≥50 ng/ ml and 423 (10.7%) had a PSA ≥ 100 ng/ ml. A serum PSA of ≥ 30 ng/ml had a positive predictive value (PPV) of 90% at a specificity of 87% and sensitivity of 78%, while a PSA ≥ 60 ng/ ml had a PPV of 98% at a specificity of 98% and sensitivity of 65% for the presence of prostate cancer. The PPV reached 99% at a PSA ≥ 100 ng/ ml and 100% at a PSA ≥ 500 ng/ ml, with a specificity of 99% and 100%, but sensitivity of only 53% and 19%, respectively.Conclusions. A serum PSA ≥ 60 ng/ ml has a PPV of 98% for the presence of adenocarcinoma of the prostate, and may be used as a surrogate for histological diagnosis where facilities for obtaining prostatic biopsies are not readily available, thus decreasing costs and patient morbidity

Early diagnosis of prostate cancer in the Western Cape

Background. Early stage prostate cancer does not cause symptoms, and even metastatic disease may exist for years without causing symptoms or signs. Whereas early stage prostate cancer can be cured with radical prostatectomy or radiotherapy, the prognosis of patients with locally advanced or metastatic cancer is significantly poorer.Objectives. ln view of the high incidence of advanced and therefore incurable prostate cancer seen at the oncology clinic of the Department of Urology, Tygerberg Hospital, we started a prostate clinic with the aim of detecting early stage prostate cancer which is potentially curable. A secondary objective was to investigate the question whether there is a higher incidence of prostate cancer among black African men.Patients and methods. Men aged 50 - 70 years were invited by means of media communications (newspaper and radio) to attend our prostate clinic for a free physical examination, including a digital rectal examination (DRE) and serum prostate specific antigen (PSA) assay. If the DRE was clinically suspicious of malignancy and/ or the serum PSA was > 4 ng/ ml, the patient was appropriately counselled and referred for transrectal ultrasound (TRUS)-guided sextant prostate biopsy.Results. In the period June 1997- September 1999 a total of 1056 men attended the prostate clinic. Biopsies were indicated in 160 cases, and were obtained in 114 (71.3%, i.e. 10.8% of the entire cohort). Prostate cancer was detected on first biopsy in 3.5% of the entire group of men (in 35.9% of those with a clinically abnormal DRE, in 41.3% of those with a serum PSA > 4 ng/ ml and in 88.6% of those with an abnormal DRE and serum PSA > 4 ng/ ml. In the 37 men with prostate cancer, the clinical tumour stage was T1 - 2 in 83.8% and T3- 4 in 16.2%. ln the group of patients with clinical stage T1 - 2 tumours, the treatment was watchful waiting in 62.5% of cases, radiotherapy in 20.8% and radical prostatectomy in 16.7%. Analysis of the data according to race showed that in the group of 47 black men there was a higher percentage of clinically abnormal DRE, PSA > 4 .0 ng/ ml and biopsies showing malignancy, and a higher overall prostate cancer detection rate (8.5%).Conclusions. Our prostate cancer detection rate of 3.5% is slightly lower than that reported in larger studies (4.7%), which may be due to the fact that prostate biopsy was performed in only 71% of those who had an indication for biopsy. ln the men diagnosed with clinically localised prostate cancer, potentially curative treatment was given in only 37.5% of cases. This compares unfavourably with the historical cohort of men seen at our oncology clinic, where 53% received potentially curative treatment, and a large European study where potentially curative treatment was given in 89% of cases. Our finding that black men had a higher percentage of clinically abnormal DRE, PSA > 4.0 ng/ ml and biopsies showing malignancy and a higher overall detection rate of prostate cancer should be interpreted with caution, since black men comprised only 4.5% of our overall study cohort.

Response assessment in lymphoma with PET/CT

No abstact available

Ultrathin compound semiconductor on insulator layers for high performance nanoscale transistors

Over the past several years, the inherent scaling limitations of electron devices have fueled the exploration of high carrier mobility semiconductors as a Si replacement to further enhance the device performance. In particular, compound semiconductors heterogeneously integrated on Si substrates have been actively studied, combining the high mobility of III-V semiconductors and the well-established, low cost processing of Si technology. This integration, however, presents significant challenges. Conventionally, heteroepitaxial growth of complex multilayers on Si has been explored. Besides complexity, high defect densities and junction leakage currents present limitations in the approach. Motivated by this challenge, here we utilize an epitaxial transfer method for the integration of ultrathin layers of single-crystalline InAs on Si/SiO2 substrates. As a parallel to silicon-on-insulator (SOI) technology14,we use the abbreviation "XOI" to represent our compound semiconductor-on-insulator platform. Through experiments and simulation, the electrical properties of InAs XOI transistors are explored, elucidating the critical role of quantum confinement in the transport properties of ultrathin XOI layers. Importantly, a high quality InAs/dielectric interface is obtained by the use of a novel thermally grown interfacial InAsOx layer (~1 nm thick). The fabricated FETs exhibit an impressive peak transconductance of ~1.6 mS/{\mu}m at VDS=0.5V with ON/OFF current ratio of greater than 10,000 and a subthreshold swing of 107-150 mV/decade for a channel length of ~0.5 {\mu}m

The transcriptome of lung tumor-infiltrating dendritic cells reveals a tumor-supporting phenotype and a microRNA signature with negative impact on clinical outcome

Targeting immunomodulatory pathways has ushered a new era in lung cancer therapy. Further progress requires deeper insights into the biology of immune cells in th

Autonomous weapons systems, killer robots and human dignity

One of the several reasons given in calls for the prohibition of autonomous weapons systems (AWS) is that they are against human dignity (Asaro in Int Rev Red Cross 94(886):687–709, 2012; Docherty in Shaking the foundations: the human rights implications of killer robots, Human Rights Watch, New York, 2014; Heyns in S Afr J Hum Rights 33(1):46–71, 2017; Ulgen in Human dignity in an age of autonomous weapons: are we in danger of losing an ‘elementary consideration of humanity’? 2016). However there have been criticisms of the reliance on human dignity in arguments against AWS (Birnbacher in Autonomous weapons systems: law, ethics, policy, Cambridge University Press, Cambridge, 2016; Pop in Autonomous weapons systems: a threat to human dignity? 2018; Saxton in (Un)dignified killer robots? The problem with the human dignity argument, 2016). This paper critically examines the relationship between human dignity and AWS. Three main types of objection to AWS are identified; (i) arguments based on technology and the ability of AWS to conform to international humanitarian law; (ii) deontological arguments based on the need for human judgement and meaningful human control, including arguments based on human dignity; (iii) consequentialist reasons about their effects on global stability and the likelihood of going to war. An account is provided of the claims made about human dignity and AWS, of the criticisms of these claims, and of the several meanings of ‘dignity’. It is concluded that although there are several ways in which AWS can be said to be against human dignity, they are not unique in this respect. There are other weapons, and other technologies, that also compromise human dignity. Given this, and the ambiguities inherent in the concept, it is wiser to draw on several types of objections in arguments against AWS, and not to rely exclusively on human dignity