Introduction to GPS and Geocaching

Grade Level(s): 6-12To familiarize students with GPS (Global Positioning Systems) and GIS (Geographic Information Systems).St. Joseph County Parks and Recreation Department South Bend, I

Some Effects in Chlorine Dioxide Purification of Kraft Softwood Cellulose

Introduction Up until the middle thirties, chlorine dioxide had been considered an expensive bleaching agent and also had been too explosive to ship as a gas, so it had remained a laboratory curiosity since its discovery in the 19th century. In the middle thirties, Mathieson Chemical Corporation found that solid sodium chlorite was a cheap and effective carrier of chlorine dioxide. This discovery opened the door for extensive use of chlorine dioxide and since then it has come into its own as a bleaching agent. This investigation is concerned with the three methods of generation of chlorine dioxide from sodium chlorite and their effects upon softwood cellulose

Head-to-head comparison of prostate cancer risk calculators predicting biopsy outcome

Background: Multivariable risk calculators (RCs) predicting prostate cancer (PCa) aim to reduce unnecessary workup (e.g., MRI and biopsy) by selectively identifying those men at risk for PCa or clinically significant PCa (csPCa) (Gleason ≥7). The lack of an adequate comparison makes choosing between RCs difficult for patients, clinicians and guideline developers. We aim to perform a head-to-head comparison of seven well known RCs predicting biopsy outcome. Methods: Our study comprised 7,119 men from ten independent contemporary cohorts in Europe and Australia, who underwent prostate biopsy between 2007 and 2015. We evaluated the performance of the ERSPC RPCRC, Finne, Chun, ProstataClass, Karakiewicz, Sunnybrook, and PCPT 2.0 (HG) RCs in predicting the presence of any PCa and csPCa. Performance was assessed by discrimination, calibration and net benefit analyses. Results: A total of 3,458 (48%) PCa were detected; 1,784 (25%) men had csPCa. No particular RC stood out predicting any PCa: pooled area under the ROC-curve (AUC) ranged between 0.64 and 0.72. The ERSPC RPCRC had the highest pooled AUC 0.77 (95% CI: 0.73-0.80) when predicting csPCa. Decision curve analysis (DCA) showed limited net benefit in the detection of csPCa, but that can be improved by a simple calibration step. The main limitation is the retrospective design of the study. Conclusions: No particular RC stands out when predicting biopsy outcome on the presence of any PCa. The ERSPC RPCRC is superior in identifying those men at risk for csPCa. Net benefit analyses show that a multivariate approach before further workup is advisable.info:eu-repo/semantics/publishedVersio

Quality of life and maladjustment associated with hair loss in women with alopecia androgenetica

Quality of life and maladjustment related to hair loss were studied by means of a standardized interview in a group of 58 women with alopecia androgenetica who applied for treatment at the Department of Dermatology. The hair loss was found to have a negative influence on the quality of life on the majority of them. In 88%, hair loss had negative effects on their daily life; in about 75%, the hair problems were manifested in negative self-esteem and about 50% experienced social problems. General psychosocial maladjustment in relation to hair loss was indicated in almost one-third of the women

Protecting the Health of First Nation Personnel at Contaminated Sites: A Case Study of Mid-Canada Radar Line Site 050 in Northern Canada

Recently, First Nation (FN) organizations have entered into agreements with federal and provincial government representatives to remediate radar-line sites in Ontario. These agreements stipulated that FN people would take part in the site delineation and remediation process to gain job experience and economic benefits. One important aspect of the process was protecting FN personnel from contaminant exposure and thus, from potential negative health outcomes associated with the cleanup work itself. In this paper, we describe the safety precautions used by FN workers preparing Mid-Canada Radar Line (MCRL) Site 050 for Phase 2 of the delineation process and the health monitoring protocol that was tested. We measured concentrations of total polychlorinated biphenyls (PCBs as Aroclor 1260), 14 individual PCB congeners, p,p’-DDT, p,p’-DDE, nine other organochlorine pesticides, and lead in the blood of Fort Albany FN workers before they started work at Site 050 and approximately a week before they completed their three-month work period in the contaminated zone. No significant differences were found in the paired samples. These results indicate that the safety precautions taken were adequate for the work and the site in question. The monitoring protocol discussed here may be used as a template and modified to meet the specific needs of other projects. The results of this study are important because other Aboriginal groups have entered or will be entering into agreements with government organizations for the remediation of other MCRL sites in Ontario and across Canada.Les stations de ligne radar désaffectées situées tant dans l’Arctique que dans le Subarctique canadiens seraient des sources ponctuelles de contamination. Des organismes des Premières nations ont participé dernièrement, avec des représentants des gouvernements fédéral et provinciaux, à des accords visant l’assainissement des stations de ligne radar en Ontario. Ces accords stipulaient que des membres des Premières nations prendraient part à la délimitation des sites et au processus d’assainissement afin d’acquérir de l’expérience de travail et de profiter des retombées économiques. Un volet important de ce processus visait à protéger le personnel autochtone de l’exposition aux contaminants et donc, d’effets potentiels négatifs pour la santé associés aux opérations de nettoyage mêmes. Dans cet article, on décrit les mesures de sécurité utilisées par les travailleurs autochtones oeuvrant sur le site 050 de la ligne radar Mid-Canada durant la phase 2 du processus de délimitation, ainsi que le protocole de contrôle de la santé mis alors à l’essai. On a mesuré les concentrations de l’accumulation de diphényles polychlorés (PCB comme l’Arochlore 1260), de 14 congénères de PCB, de p,p’-DDT, de p,p’-DDE, de neuf autres pesticides organochlorés ainsi que de plomb dans le sang des travailleurs autochtones de Fort Albany avant qu’ils commencent à travailler au site 050 et une semaine environ avant qu’ils terminent leur période de travail de trois mois dans la zone contaminée. On n’a pas trouvé de différences significatives entre les échantillons appariés. Ces résultats révèlent que les mesures de sécurité prises étaient adéquates pour le travail et le site en question. Le protocole de contrôle discuté ici pourrait servir de modèle et être adapté pour répondre aux critères spécifiques d’autres projets. Les résultats de cette étude sont importants car d’autres groupes autochtones participent actuellement ou vont participer à des accords avec des agences gouvernementales visant l’assainissement d’autres sites de la ligne radar Mid-Canada en Ontario et à travers le Canada

Geographic and temporal validity of prediction models: different approaches were useful to examine model performance

AbstractObjectiveValidation of clinical prediction models traditionally refers to the assessment of model performance in new patients. We studied different approaches to geographic and temporal validation in the setting of multicenter data from two time periods.Study Design and SettingWe illustrated different analytic methods for validation using a sample of 14,857 patients hospitalized with heart failure at 90 hospitals in two distinct time periods. Bootstrap resampling was used to assess internal validity. Meta-analytic methods were used to assess geographic transportability. Each hospital was used once as a validation sample, with the remaining hospitals used for model derivation. Hospital-specific estimates of discrimination (c-statistic) and calibration (calibration intercepts and slopes) were pooled using random-effects meta-analysis methods. I2 statistics and prediction interval width quantified geographic transportability. Temporal transportability was assessed using patients from the earlier period for model derivation and patients from the later period for model validation.ResultsEstimates of reproducibility, pooled hospital-specific performance, and temporal transportability were on average very similar, with c-statistics of 0.75. Between-hospital variation was moderate according to I2 statistics and prediction intervals for c-statistics.ConclusionThis study illustrates how performance of prediction models can be assessed in settings with multicenter data at different time periods

Fingerprints of Teaching Interactions:Capturing and Quantifying How Supervisor Regulate Autonomy of Residents in the Operating Room

Objective: Supervisors and residents agree that entrusted autonomy is central to learning in the Operating Room (OR), but supervisors and residents hold different opinions about entrustment: residents regularly experience that they receive insufficient autonomy while supervisors feel their guiding is not appreciated as teaching. These opinions are commonly grounded on general experiences and perceptions, instead of real-time supervisors’ regulatory behaviors as procedures unfold. To close that gap, we captured and analyzed when and to what level supervisors award or restrain autonomy during procedures. Furthermore, we constructed fingerprints, an instrument to visualize entrustment of autonomy by supervisors in the OR that allows us to reflect on regulation of autonomy and discuss teaching interactions. Design: All interactions between supervisors and residents were captured by video and transcribed. Subsequently a multistage analysis was performed: (1) the procedure was broken down into 10 steps, (2) for each step, type and frequency of strategies by supervisors to regulate autonomy were scored, (3) the scores for each step were plotted into fingerprints, and (4) fingerprints were analyzed and compared. Setting: University Medical Centre Groningen (the Netherlands). Participants: Six different supervisor-resident dyads. Results: No fingerprint was alike: timing, frequency, and type of strategy that supervisors used to regulate autonomy varied within and between procedures. Comparing fingerprints revealed that supervisors B and D displayed more overall control over their program-year 5 residents than supervisors C and E over their program-year 4 residents. Furthermore, each supervisor restrained autonomy during steps 4 to 6 but with different intensities. Conclusions: Fingerprints show a high definition view on the unique dynamics of real-time autonomy regulation in the OR. One fingerprint functions as a snapshot and serves a purpose in one-off teaching and learning. Multiple snapshots of one resident quantify autonomy development over time, while multiple snapshots of supervisors may capture best teaching practices to feed train-the-trainer programs