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The decay of the photoluminescence at 1.54 μm from erbium-implanted silicon has been recorded over nearly three decades of intensity. Two components of the decay are observed at 7.5 K, one with a decay time constant of ∼40-160 μs, and the other with a characteristic time of between 800 and 1200 μs. It is found that the proportions of fast and slow components can vary depending upon the amount of implantation-induced damage, and this variation correlates with a broadening on the high energy side of the erbium related emission. The temperature dependence of the fastest decay is not consistent with it being due to an Auger process involving free carriers, and it is suggested that extended defects in the layers are responsible for this part of the decay curve. The broadening of the erbium line is attributed to the overlap of the dislocation-related line D1 with the erbium emission. Selective chemical etching and scanning electron microscopy show that there are extended defects present in samples with a short fast decay component. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Minimally invasive techniques in transhiatal esophagectomy (THE) were introduced to reduce morbidity and enhance postoperative recovery. Aim of this study was to systematically review the current status and possible beneficial effects of the minimally invasive approach in THE. A systematic search was performed in PubMed, the Cochrane Library, and Embase to identify English articles published on laparoscopic THE. Comparative cohort studies were included for critical appraisal. Data describing perioperative and oncological outcomes were analyzed. A total of four comparative cohort studies that compared laparoscopic THE (n=122) with open THE (n=144) and four noncomparative cohort studies reporting on laparoscopic THE (n=212) were included in this review. Median blood loss was significantly lower in the laparoscopic group in all studies (100-500 vs. 526-900 mL). Length of hospital stay was also significantly shorter for the laparoscopic approach in all studies (9-13 vs. 12-16 days). One study reported less major postoperative complications after laparoscopic THE (12 vs. 23%), in the other studies no differences were found. Also no differences were found with regard to operating time, postoperative morbidity, radicality, and lymph node retrieval. Based on these pioneer studies, laparoscopic THE was demonstrated to be safe and feasible with evidence of reduced blood loss and shorter hospital stays. However, level 1 evidence is lacking and further research is warranted to confirm these findings and also to evaluate long-term oncologic outcomes. [ABSTRACT FROM AUTHOR]

Esophageal and gastric cancer is associated with a poor prognosis since many patients develop recurrent disease. Treatment requires specific expertise and a structured multidisciplinary approach. In the Netherlands, this type of expertise is mainly found at the University Medical Centers ( UMCs) and a few specialized nonacademic centers. Aim of this study is to implement a national infrastructure for research to gain more insight in the etiology and prognosis of esophageal and gastric cancer and to evaluate and improve the response on (neoadjuvant) treatment. Clinical data are collected in a prospective database, which is linked to the patients' biomaterial. The collection and storage of biomaterial is performed according to standard operating procedures in all participating UMCs as established within the Parelsnoer Institute. The collected biomaterial consists of tumor biopsies, blood samples, samples of malignant and healthy tissue of the resected specimen and biopsies of recurrence. The collected material is stored in the local biobanks and is encoded to respect the privacy of the donors. After approval of the study was obtained from the Institutional Review Board, the first patient was included in October 2014. The target aim is to include 300 patients annually. In conclusion, the eight UMCs of the Netherlands collaborated to establish a nationwide database of clinical information and biomaterial of patients with esophageal and gastric cancer. Due to the national coverage, a high number of patients are expected to be included. This will provide opportunity for future studies to gain more insight in the etiology, treatment and prognosis of esophageal and gastric cancer. [ABSTRACT FROM AUTHOR]

A series of zinc oxide based varistors containing 0.5 wt% Bi2O3 and 0.5 wt% Mn2O3 was prepared by a conventional mixed oxide route and sintered at temperatures between 950° and 1300°C. All samples showed varistor behaviour, although as the sintering temperature was increased from 950°C to 1300°C, the non-linearity coefficient, α, decreased from 22 to 3. Deep level transient spectroscopy of the varistors showed that the main active electron trap migrated to shallower levels within the bandgap as the sintering temperature increased. At the lowest sintering temperature, where α attained the highest values, a second, shallower trap was also activated. [ABSTRACT FROM AUTHOR]

In this study we describe a predictable but previously poorly investigated relationship between transformational/transactional organisational leadership culture and participation in discretionary behaviour. Perceptions of organisational leadership culture were found to have a significant effect across the organisation on one measure of discretionary activity, specifically the completing and returning of a work-related questionnaire. Utilising wave analysis and One-Way Analysis of Variance (ANOVA), findings suggested that respondents from differing organisational culture types responded to the questionnaire at different rates. Later respondents perceived lower levels of transformational culture and higher levels of transactional culture within their organisation than did early respondents. This finding suggests that as organisations become more transactional, employees are less likely to engage in work related discretionary behaviour. Therefore, in practical terms there are strong reasons why leaders should make organisational culture as transformational and non-transactional as reasonably possible. Other implications of findings are discussed and future enquires are suggested. [ABSTRACT FROM AUTHOR]

We describe the development and diagnosis of a two-stage plasma discharge in which a source plasma is separated from a secondary process plasma by a fine mesh. Through the application of a DC bias potential to the mesh the electron temperature Te and mean ion bombarding energy Ei to an electrically isolating substrate can be well controlled in the secondary discharge. Electrical probe and retarding field analyser measurements have shown that Te and Ei can be varied in the range 0.2–4 and 1–26 eV, respectively, and are found to be spatially uniform. Using this system, the bombarding ion flux can also be varied in the range from 1017 to 1019 m−2 s−1, independently of the ion energy through the combined variation of the primary discharge power, and pressure and substrate location. These types of plasmas may find applications in the controlled plasma modification of materials through tailoring of the ion energy and flux. [Copyright &y& Elsevier]

Objective To evaluate p53 and bcl-2 immunohistochemistry in preoperative biopsies and radical prostatectomy specimens, as predictors of biochemical recurrence. Patients and methods Preoperative biopsies from 73 men, and the radical prostatectomies from these men and from a further 47 men, were evaluated. The serum prostate specific antigen (PSA) level, Gleason score, pathological stage and margin involvement were recorded. The immunohistochemical expression of p53 and bcl-2 was studied on a representative area of tumour with the highest Gleason grade. The median follow-up was 53 months. Results During the follow-up 47 of the 120 patients had a biochemical recurrence. Capsular penetration was present in 63 (53%) and the surgical margins were positive in 47 (39%). The Gleason score was < 7 in 81 (68%) patients; p53 was positive in 40 (66%) of 61 biopsies and 84 (71%) of 118 prostatectomy specimens. Bcl-2 was positive in eight (13%) of 63 biopsies and 20 (17%) of 118 prostatectomies. On multivariate analysis the biopsy p53, Gleason score and serum PSA were significant predictors of recurrence. On multivariate analysis, capsular penetration, PSA and margin status at prostatectomy were significant predictors of recurrence. There was also a significant interaction between PSA and margin status. Although univariately significant, neither p53 nor bcl-2 featured in the final multivariate model. Conclusion Biopsy p53 status significantly predicts recurrence after radical prostatectomy, but its low specificity and technical issues suggest that it will not be useful in the clinical setting. However, a patient with negative p53 on biopsy is likely to have a good prognosis on prolonged follow-up. [ABSTRACT FROM AUTHOR]

This radiographic retrospective cohort study aims to identify relations between the prearthrotic anatomy of the hip joint and the type of subsequent osteoarthrosis (OA). Radiographs of 64 hips in 47 patients were evaluated. Several anatomical indices were measured on radiographs obtained before the onset of OA. The location, type and grade of OA were recorded on subsequent radiographs. Due to the small number of hips available, only three potential risk factors could be considered for both OA location and OA type (weight-bearing surface angle, spherical sector and neck shaft angle for both outcomes). The only variable that was found to be a significant predictor of OA location was the degree of inclination of the acetabular sourcil. Patients with craniomedial sourcils were more likely to have medial OA. No predictors of OA type could be identified. Our results suggest that the anatomy of the hip joint is a factor determining the location of developing osteoarthrosis. [ABSTRACT FROM AUTHOR]

This paper reports on the introduction of SWM technology, soil moisture and nutrient monitoring tools, alongside Agricultural Innovation Platforms (AIP) in three small-scale irrigation schemes in southern Africa. Quantitative and qualitative data are presented on the changes and benefits that have resulted, including increased yield and profitability. The findings emphasize that information prior and subsequent to adoption is needed, and the importance of understanding and enhancing the incentive framework for behavioural change, including both economic and physical returns. The findings illustrate SWM technology is strengthened when introduced with credible multi-stakeholder processes, such as an AIP, that facilitate institutional innovation. [ABSTRACT FROM AUTHOR]

This paper analyses the capacity of participatory mapping as a multi-level learning process to identify and overcome current barriers to productivity within small-scale irrigation schemes. The analysis is based on thirteen smallholder irrigation schemes in Tanzania, Mozambique, and Zimbabwe, where farmers, project officers and other key stakeholders participated in informal mapping teams to map the schemes. Critically, participatory mapping translated problems generally known by stakeholders into problems that were publicly known, making their resolution a shared responsibility. Hence, problems identified at both the scheme and plot levels led to immediate responses by the farmers, irrigator organizations, and government departments, boosting farmers' agency and confidence and renewing their sense of scheme and plot ownership. It is important that irrigation agencies prioritize participatory processes and the use of informal networks to improve farmers' understanding of their resource and management challenges and to build their sense of ownership and responsibility for effective management of irrigation schemes. • Participatory mapping process stimulated changes in irrigation management at scheme level. • The process increased a sense of ownership at the plot, scheme and local authority levels. • The process translated problems generally known by stakeholders into problems that are publicly known. • The process resolved problems and implemented some of the solutions. [ABSTRACT FROM AUTHOR]

In this paper we present an overview of the deep states present after ion-implantation by various species into n-type silicon, measured by Deep Level Transient Spectroscopy (DLTS) and high resolution Laplace DLTS (LDLTS). Both point and small extended defects are found, prior to any anneal, which can therefore be the precursors to more detrimental defects such as end of range loops. We show that the ion mass is linked to the concentrations of defects that are observed, and the presence of small interstitial clusters directly after ion implantation is established by comparing their behaviour with that of electrically active stacking faults. Finally, future applications of the LDLTS technique to ion-implanted regions in Si-based devices are outlined. [ABSTRACT FROM AUTHOR]