Impact of 20-day strike in Polokwane Hospital (18 August - 6 September 2010)

Background. Doctors’ strikes have a negative effect on hospital performance indicators. Hospital mortality during such strikes is the most important indicator. Objective. To determine the effects of the 2010 strike on Polokwane Hospital. Methods. Information was collected from the Hospital Information System, Polokwane Hospital Casualty Department, wards and theatres. Results. During the 20-day strike, a total of 262 patients were admitted to Polokwane Hospital, with 40 patients to the surgical department; 96 operations were performed in the hospital and 40 in the surgical department; and 50 deaths were reported in the hospital (8 deaths in the surgical department). During 20 days of a non-striking period in May 2010, there were 975 admissions to the hospital, with 125 to the surgical department. In the entire hospital, 340 operations were performed, and 79 in the surgical department. For this period, 61 deaths were reported in the hospital and 12 in the surgical department. Conclusions. The total number of patients admitted to the hospital and the surgical department during the strike was significantly lower than during a non-striking situation. Total mortality during the strike in Polokwane Hospital decreased, compared with the normal situation, but it increased when judged against emergency cases. However, when mortality was qualified by the number of admissions, it showed a significant increase. Strikes seriously and significantly affect service delivery

Nodular thyroid disease and thyroid malignancy: Experience at Polokwane Mankweng Hospital Complex, Limpopo Province, South Africa

Background. Nodular thyroid disease is common throughout the world. Numbers of patients with goitre are increasing worldwide, as also noted in Limpopo Province, South Africa (SA). Globally, thyroid nodules have been reported in 4 - 7% of the population on neck palpation and in 30 - 50% by ultrasonography.Objectives. To review the profile of thyroid disease in patients with goitre presenting to the Department of Surgery at Polokwane Mankweng Hospital Complex (PMHC), Limpopo, SA, to characterise the pattern of malignancy in patients with goitre, and to determine the most common thyroid cancer.Method. A 6-year retrospective study (2003 - 2008) of all patients with thyroid nodules who underwent thyroid surgery at PMHC. Results. The study group included 90 patients (mean age 45 years, range 4 - 80). The male-to-female ratio was 1:17 (5 men, 85 women). Of these patients, 80 (89.9%) had benign lesions, of which 52 (57.8% of the total) were adenomas, 25 (27.8%) multinodular goitres (MNGs), 2 (2.2%) hyperplastic nodules and 1 (1.1%) Hashimoto’s thyroiditis. Ten patients (11.1%) had malignant lesions (7 follicular carcinomas and 3 papillary carcinomas), of which 2 were found in MNGs. Conclusions. Adenoma and MNG were the predominant non-malignant conditions (85.6%). The prevalence of thyroid cancer in our study was 11.1%, and of all 90 patients, 7.8% had follicular carcinoma. The risk of malignancy in MNG was 8.9%. Rates of thyroid nodules and carcinoma were highest in women aged 41 - 60 years. We advocate that total thyroidectomy be considered for MNG, because MNG can harbour incidental carcinoma.

Provision of an emergency theatre in tertiary hospitals is cost-effective: Audit and cost of cancelled planned elective general surgical operations at Pietersburg Hospital, Limpopo Province, South Africa

Background. Cancellations of planned elective surgical operations increase financial cost to the patient and the hospital. Objectives. To determine the rate and reasons for cancellations, estimate the cost incurred by such cancellations and recommend possible solutions. Methods. We did a prospective descriptive study of cancellations of elective general surgical operations over the 1-year period January - December 2014 in the main theatre at Pietersburg (PTB) Hospital, Limpopo Province, South Africa. All patients listed on the theatre booking slate for elective general surgical operations before the cut-off time of 13h00 on the day before the anticipated operation were included. Epi Infoversion 7 was used to analyse the data and derive the descriptive statistics. Results. There were 537 booked patients (median age 47 years, range 1 - 94); a total of 298 operations were performed, and 239 were cancelled (cancellation rate 44.5%). Reasons for cancellation were as follows: theatre needed for an emergency n=154 (64.4%), theatre equipment failure and lack of consumables n=17 (7.1%), non-theatre equipment failure n=10 (4.2%), prolonged time of operations n=13 (5.4%), abnormal blood results n=8 (3.3%), patient comorbidity and poor general condition n=9 (3.8%), patients absent from the ward n=8 (3.3%), patients not starved n=2 (0.8%), patients’ condition improved significantly n=3 (1.3%), nurses’ strike n=5 (2.1%), rebooking of cases for senior surgeons or other specialty n=2 (0.8%), and other reasons n=8 (3.3%). The cost per inpatient per day was estimated at ZAR4 890 at PTB Hospital and ZAR2 100 at district hospitals, and the total cost per cancelled operation was ZAR25 860. Conclusions. Over the 1-year period 44.5% of elective operations at PTB Hospital were cancelled, 64.4% because the theatre was needed for an emergency operation. We recommend that a theatre dedicated to emergencies be opened at PTB Hospital. The cost incurred due to cancellations was about ZAR6 million for the hospital, with additional cost and emotional trauma for the patients

The late Vistulian and Holocene evolution of Jezioro Lake : a record of environmental change in southern Poland found in deposits and landforms

Jezioro Lake is the only natural lake in southern Poland outside mountainous areas to have existed continuously since the Pleistocene. The record of environmental change in the Late Vistulian (Weichselian) and Holocene is preserved in the deposits and landforms around the lake. This paper presents the results of paleogeographical and paleoecological research that emabled us to reconstruct the history of the Jezioro Lake. At the end of the Vistulian period, the outlet of the lake was blocked by a parabolic dune moving in from the west. Limnic sedimentation was evident in the sediment core at all levels from the Holocene, with remains of Cladocera, Chironomidae larvae, and aquatic plants. The lake did not disappear at that time, although its area decreased by a factor of 12 by the end of the period. Paleobotanical research permitted the reconstruction of sequences of plant communities and changes in nutrient status and water level. An initial oligotrophic lake, as indicated by the presence of Isoe¨tes lacustris L., changed to a eutrophic lake, as indicated by the presence of Potamogeton natans L. and Nuphar sp., then the lake progressed to the present-day dystrophic lake that is surrounded by a swamp. The profile of organic deposits contains a record of environmental change at least since the Younger Dryas in southern Poland

On-line power system inertia calculation using wide area measurements

Future developments in power systems, e.g. relatively larger generator sets, the virtual power plant and synthetic inertia concept and connection of generation assets over inverters, will cause the system inertia to vary significantly. During system operation, if the inertia of the system is significantly lower than anticipated at the planning stage, then the existing, deterministic protection and control may fail to ensure system stability. Therefore, the ability to accurately determine the inertia of individual system areas, and the system as a whole, online would be very useful. In this paper, an Inertia Calculation Application (ICA), which could be implemented as part of a Wide Area Monitoring Protection and Control scheme, is presented. The necessary wide area measurements must be processed during large disturbances to the active power balance of the system. The ICA has been validated by using computer simulations, under laboratory conditions and by using real-life data recorded by a transmission system operator

Spontaneous Emergence of Multiple Drug Resistance in Tuberculosis before and during Therapy

The emergence of drug resistance in M. tuberculosis undermines the efficacy of tuberculosis (TB) treatment in individuals and of TB control programs in populations. Multiple drug resistance is often attributed to sequential functional monotherapy, and standard initial treatment regimens have therefore been designed to include simultaneous use of four different antibiotics. Despite the widespread use of combination therapy, highly resistant M. tb strains have emerged in many settings. Here we use a stochastic birth-death model to estimate the probability of the emergence of multidrug resistance during the growth of a population of initially drug sensitive TB bacilli within an infected host. We find that the probability of the emergence of resistance to the two principal anti-TB drugs before initiation of therapy ranges from 10−5 to 10−4; while rare, this is several orders of magnitude higher than previous estimates. This finding suggests that multidrug resistant M. tb may not be an entirely “man-made” phenomenon and may help explain how highly drug resistant forms of TB have independently emerged in many settings

VapC Toxins from Mycobacterium tuberculosis Are Ribonucleases that Differentially Inhibit Growth and Are Neutralized by Cognate VapB Antitoxins

The chromosome of Mycobacterium tuberculosis (Mtb) encodes forty seven toxin-antitoxin modules belonging to the VapBC family. The role of these modules in the physiology of Mtb and the function(s) served by their expansion are unknown. We investigated ten vapBC modules from Mtb and the single vapBC from M. smegmatis. Of the Mtb vapCs assessed, only Rv0549c, Rv0595c, Rv2549c and Rv2829c were toxic when expressed from a tetracycline-regulated promoter in M. smegmatis. The same genes displayed toxicity when conditionally expressed in Mtb. Toxicity of Rv2549c in M. smegmatis correlated with the level of protein expressed, suggesting that the VapC level must exceed a threshold for toxicity to be observed. In addition, the level of Rv2456 protein induced in M. smegmatis was markedly lower than Rv2549c, which may account for the lack of toxicity of this and other VapCs scored as ‘non-toxic’. The growth inhibitory effects of toxic VapCs were neutralized by expression of the cognate VapB as part of a vapBC operon or from a different chromosomal locus, while that of non-cognate antitoxins did not. These results demonstrated a specificity of interaction between VapCs and their cognate VapBs, a finding corroborated by yeast two-hybrid analyses. Deletion of selected vapC or vapBC genes did not affect mycobacterial growth in vitro, but rendered the organisms more susceptible to growth inhibition following toxic VapC expression. However, toxicity of ‘non-toxic’ VapCs was not unveiled in deletion mutant strains, even when the mutation eliminated the corresponding cognate VapB, presumably due to insufficient levels of VapC protein. Together with the ribonuclease (RNase) activity demonstrated for Rv0065 and Rv0617 – VapC proteins with similarity to Rv0549c and Rv3320c, respectively – these results suggest that the VapBC family potentially provides an abundant source of RNase activity in Mtb, which may profoundly impact the physiology of the organism

Analysis of a bistable climate toy model with physics-based machine learning methods

We propose a comprehensive framework able to address both the predictability of the first and of the second kind for high-dimensional chaotic models. For this purpose, we analyse the properties of a newly introduced multistable climate toy model constructed by coupling the Lorenz ’96 model with a zero-dimensional energy balance model. First, the attractors of the system are identified with Monte Carlo Basin Bifurcation Analysis. Additionally, we are able to detect the Melancholia state separating the two attractors. Then, Neural Ordinary Differential Equations are applied to predict the future state of the system in both of the identified attractors