167 research outputs found
Interaction and transaction : a study of conciliar behaviour in a Black South African township
The recent history of Africa is one of rapid chance. This process is still continuing and even accelerating. The peoples of Africa are being drawn from a subsistence way of life to a money economy and, more often than not, from a rural to an urban environment. South Africa is no exception to this pattern. In fact, as the most developed country on the continent it is in the front-line of this transformation. Various facets of this problem have held the attention of anthropologists world-wide. Southern Africa specifically has produced some of the earliest urban studies (Hellman, 1948), as well as some of the classical contributions to the field (Mitchell, 1956, 1960, 1966, 1969, 1970; Epstein, 1958; Mayer, 1961, "(1971), 1962; Pauw, 1963). Complex as the urban problems are, anthropologists have obviously not been alone in this field. Workers from many disciplines have been and still are required to contribute to the understanding of the process or urbanization as well as the urban process. Partly for this reason no attempt has been made in the present study to illuminate all the varied facets of the urban field. In general, the focus has been on the urban process and more specifically, on part of a local-level political system. Thus only a limited problem has been selected for analysis
From numbers to meaningful change:Minimal important change by using PROMIS in a cohort of fracture patients
Introduction: use of the Patient-Reported Outcomes measurement Information System (PROMISŸ) is slowly increasing in patients with a fracture. Yet, minimal important change of PROMIS in patients with fractures has been addressed in a very limited number of studies. As the minimal important change (MIC) is important to interpret PROMIS-scores, the goal is to estimate the MIC for PROMIS physical function (PF), PROMIS pain interference (PI) and PROMIS ability to participate in social roles and activities (APSRA) in patients with a fracture. Secondly, the smallest detectable change was determined. Materials and methods: A longitudinal cohort study on patients ℠18 years receiving surgical or non-surgical care for fractures was conducted. Patients completed PROMIS PF V1.1, PROMIS PI V1.1 and PROMIS APSRA V2.0. For follow-up, patients completed three additional anchor questions evaluating patient-reported improvement on a seven point rating scale. The predictive modeling method was used to estimate the MIC value of all three PROMIS questionnaires. Results: Hundred patients with a mean age of 55.4 ± 12.6 years were included of which sixty (60%) were female. Seventy-two (72%) patients were recovering from a surgical procedure. PROMIS-CAT T-scores of all PROMIS measures showed significant correlations with their anchor questions. The predictive modeling method showed a MIC value of +2.4 (n = 98) for PROMIS PF, -2.9 (n = 96) for PROMIS PI and +3.2 (n = 91) for PROMIS APSRA. Conclusion: By using the anchor based predictive modeling method, PROMIS MIC-values for improvement of respectively +2.4 points on a T-score metric for PROMIS-PF, -2.9 for PROMIS-PI and +3.2 for PROMIS APSRA give the impression of being meaningful to patients. These values can be used in clinical practice for managing patient expectations; to inform on treatment results; and to assess if patients experience significant change. This in order to encourage patient centered care.</p
Machine-learning-based Bayesian state estimation in electrical energy systems
In many algorithmic applications in electrical power grids, state estimation (SE) represents the first step of a
process chain. In SE, sensor measurements are processed to infer the most probable grid state. Classical methods
such as weighted least squares (WLSs) based approaches use statistical methods that can be based on sensor noise
and erroneous measurements. With these methods, only point estimates are made, which results in a lack of
knowledge about prediction uncertainties. In this study, machine-learning-based methods for determining the actual
state of the grid are proposed. Bayesian optimisation is applied to find the optimal hyperparameter configurations for
neural networks (NNs) for SE tasks. The application of Bayesian inference using Bayesian NNs is proposed, which
allows the prediction of point estimates as well as uncertainty intervals for the system states. The advantages of using
Bayesian approaches in comparison to classical SE methods like WLS are shown
Functional brush poly(2-ethyl-2-oxazine)s : synthesis by CROP and RAFT, thermoresponsiveness and grafting onto iron oxide nanoparticles
Brush polymers are highly functional polymeric materials combining the properties of different polymer classes and have found numerous applications, for example, in nanomedicine. Here, the synthesis of functional phosphonateâesterâbearing brush polymers based on poly(2âoxazine)s is reported through a combination of cationic ringâopening polymerization (CROP) of 2âethylâ2âoxazine and reversible additionâfragmentation chain transfer (RAFT) polymerization. In this way, a small library of wellâdefined (Ä â€ 1.17) poly(oligo(2âethylâ2âoxazine) methacrylate) P(OEtOzMA)n brushes with tunable lower critical solution temperature (LCST) behavior and negligible cell toxicity is prepared. Upon deprotection, the phosphonic acid endâgroup of the P(OEtOzMA)n brush enables the successful graftingâonto iron oxide nanoparticles (IONPs). Colloidal stability of the particle suspension in combination with suitable magnetic resonance imaging (MRI) relaxivities demonstrates the potential of these particles for future applications as negative MRI contrast agents
An order-theoretic characterization of the Howard-Bachmann-hierarchy
In this article we provide an intrinsic characterization of the famous Howard-Bachmann ordinal in terms of a natural well-partial-ordering by showing that this ordinal can be realized as a maximal order type of a class of generalized trees with respect to a homeomorphic embeddability relation. We use our calculations to draw some conclusions about some corresponding subsystems of second order arithmetic. All these subsystems deal with versions of light-face Î âÂč-comprehension
Back-Table Fluorescence-Guided Imaging for Circumferential Resection Margin Evaluation Using Bevacizumab-800CW in Patients with Locally Advanced Rectal Cancer
Negative circumferential resection margins (CRM) are the cornerstone for the curative treatment of locally advanced rectal cancer (LARC). However, in up to 18.6% of patients, tumor-positive resection margins are detected on histopathology. In this proof-of-concept study, we investigated the feasibility of optical molecular imaging as a tool for evaluating the CRM directly after surgical resection to improve tumor-negative CRM rates. Methods: LARC patients treated with neoadjuvant chemoradiotherapy received an intravenous bolus injection of 4.5 mg of bevacizumab-800CW, a fluorescent tracer targeting vascular endothelial growth factor A, 2-3 d before surgery (ClinicalTrials.gov identifier: NCT01972373). First, for evaluation of the CRM status, back-table fluorescence guided imaging (FGI) of the fresh surgical resection specimens (n = 8) was performed. These results were correlated with histopathology results. Second, for determination of the sensitivity and specificity of bevacizumab-800CW for tumor detection, a mean fluorescence intensity cutoff value was determined from the formalin-fixed tissue slices (n = 42; 17 patients). Local bevacizumab-800CW accumulation was evaluated by fluorescence microscopy. Results: Back-table FGI correctly identified a tumor-positive CRM by high fluorescence intensities in 1 of 2 patients (50%) with a tumor-positive CRM. For the other patient, low fluorescence intensities were shown, although (sub)millimeter tumor deposits were present less than 1 mm from the CRM. FGI correctly identified 5 of 6 tumor-negative CRM (83%). The 1 patient with false-positive findings had a marginal negative CRM of only 1.4 mm. Receiver operating characteristic curve analysis of the fluorescence intensities of formalin-fixed tissue slices yielded an optimal mean fluorescence intensity cutoff value for tumor detection of 5,775 (sensitivity of 96.19% and specificity of 80.39%). Bevacizumab-800CW enabled a clear differentiation between tumor and normal tissue up to a microscopic level, with a tumor-to-background ratio of 4.7 +/- 2.5 (mean SD). Conclusion: In this proof-of-concept study, we showed the potential of back-table FGI for evaluating the CRM status in LARC patients. Optimization of this technique with adaptation of standard operating procedures could change perioperative decision making with regard to extending resections or applying intraoperative radiation therapy in the case of positive CRM
Evaluation of the Berlin polytrauma definition:A Dutch nationwide observational study
BACKGROUND The Berlin polytrauma definition (BPD) was established to identify multiple injury patients with a high risk of mortality. The definition includes injuries with an Abbreviated Injury Scale score of >= 3 in >= 2 body regions (2AIS >= 3) combined with the presence of >= 1 physiological risk factors (PRFs). The PRFs are based on age, Glasgow Coma Scale, hypotension, acidosis, and coagulopathy at specific cutoff values. This study evaluates and compares the BPD with two other multiple injury definitions used to identify patients with high resource utilization and mortality risk, using data from the Dutch National Trauma Register (DNTR). METHODS The evaluation was performed based on 2015 to 2018 DNTR data. First, patient characteristics for 2AIS >= 3, Injury Severity Score (ISS) of >= 16, and BPD patients were compared. Second, the PRFs prevalence and odds ratios of mortality for 2AIS >= 3 patients were compared with those from the Deutsche Gesellschaft fur Unfallchirurgie Trauma Register. Subsequently, the association between PRF and mortality was assessed for 2AIS >= 3-DNTR patients and compared with those with an ISS of >= 16. RESULTS The DNTR recorded 300,649 acute trauma admissions. A total of 15,711 patients sustained an ISS of >= 16, and 6,263 patients had suffered a 2AIS >= 3 injury. All individual PRFs were associated with a mortality of >30% in 2AIS >= 3-DNTR patients. The increase in PRFs was associated with a significant increase in mortality for both 2AIS >= 3 and ISS >= 16 patients. A total of 4,264 patients met the BPDs criteria. Overall mortality (27.2%), intensive care unit admission (71.2%), and length of stay were the highest for the BPD group. CONCLUSION This study confirms that the BPD identifies high-risk patients in a population-based registry. The addition of PRFs to the anatomical injury scores improves the identification of severely injured patients with a high risk of mortality. Compared with the ISS >= 16 and 2AIS >= 3 multiple injury definitions, the BPD showed to improve the accuracy of capturing patients with a high medical resource need and mortality rate
Metallic and complex hydride-based electrochemical storage of energy
The development of efficient storage systems is one of the keys to the success of the energy transition. There are many ways to store energy, but among them, electrochemical storage is particularly valuable because it can store electrons produced by renewable energies with a very good efficiency. However, the solutions currently available on the market remain unsuitable in terms of storage capacity, recharging kinetics, durability, and cost. Technological breakthroughs are therefore expected to meet the growing need for energy storage. Within the framework of the Hydrogen Technology Collaboration ProgramâH2TCP Task-40, IEA\u27s expert researchers have developed innovative materials based on hydrides (metallic or complex) offering new solutions in the field of solid electrolytes and anodes for alkaline and ionic batteries. This review presents the state of the art of research in this field, from the most fundamental aspects to the applications in battery prototypes
Doxorubicin Exposure and Breast Cancer Risk in Survivors of Adolescent and Adult Hodgkin Lymphoma
PURPOSEFemale Hodgkin lymphoma (HL) survivors treated with chest radiotherapy (RT) at a young age have a strongly increased risk of breast cancer (BC). Studies in childhood cancer survivors have shown that doxorubicin exposure may also increase BC risk. Although doxorubicin is the cornerstone of HL chemotherapy, the association between doxorubicin and BC risk has not been examined in HL survivors treated at adult ages.METHODSWe assessed BC risk in a cohort of 1,964 female 5-year HL survivors, treated at age 15-50 years in 20 Dutch hospitals between 1975 and 2008. We calculated standardized incidence ratios, absolute excess risks, and cumulative incidences. Doxorubicin exposure was analyzed using multivariable Cox regression analyses.RESULTSAfter a median follow-up of 21.6 years (IQR, 15.8-27.1 years), 252 women had developed invasive BC or ductal carcinoma in situ. The 30-year cumulative incidence was 20.8% (95% CI, 18.2 to 23.4). Survivors treated with a cumulative doxorubicin dose of >200 mg/m2 had a 1.5-fold increased BC risk (95% CI, 1.08 to 2.1), compared with survivors not treated with doxorubicin. BC risk increased 1.18-fold (95% CI, 1.05 to 1.32) per additional 100 mg/m2 doxorubicin (Ptrend =.004). The risk increase associated with doxorubicin (yes v no) was not modified by age at first treatment (hazard ratio [HR]age <21 years, 1.5 [95% CI, 0.9 to 2.6]; HRage â„21 years, 1.3 [95% CI, 0.9 to 1.9) or chest RT (HRwithout mantle/axillary field RT, 1.9 [95% CI, 1.06 to 3.3]; HRwith mantle/axillary field RT, 1.2 [95% CI, 0.8 to 1.8]).CONCLUSIONThis study shows that treatment with doxorubicin is associated with increased BC risk in both adolescent and adult HL survivors. Our results have implications for BC surveillance guidelines for HL survivors and treatment strategies for patients with newly diagnosed HL.</p
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