A case study of sea breeze circulation at Thumba Coast through observations and modelling

NASA Astrophysics Data System (ADS)

Kunhikrishnan, P. K.; Ramachandran, Radhika; Alappattu, Denny P.; Kiran Kumar, N. V. P.; Balasubrahamanyam, D.

2006-12-01

A case study of sea breeze circulation at a coastal region Thumba (8.5°N, 76.9°E) was carried out using Doppler Sodar, surface wind, temperature, humidity measurements and radiosonde ascents. The analysis of surface meteorological data showed that the onset of sea breeze on 12th April 2006 was at 0945 hrs. GPS sonde observation over sea at 1425 hrs and Radiosonde observation over land at 1730 showed a well developed sea breeze circulation over Thumba coast by afternoon hours. The vertical extent of sea breeze circulation was ~1000m over sea as well as on land. The Thermal Internal Boundary Layer (TIBL) depth associated with sea breeze circulation was about 400m at 8 km away from coast. The marine mixed layer height was ~500m about 12 km away from the coast. Numerical simulation of sea breeze was made using HRM (High Resolution Model) and compared the results with the observations.

[Facial mucormycosis: observations from three cases].

PubMed

Sellami-Boudawara, T; Gouiaa, N; Charfeddine, I; Abdelmoula, M; Drira, M; Jlidi, R

2002-12-01

The mucormycosis is a rare opportunistic invasive infection caused by fungi of the order Mucorales and characterized by vascular invasion and tissue necrosis. It affects generally the subjects with altered natural resistances, particularly the diabetics patients. The cerebro-rhino-orbital region is the most common site. The clinical signs depend on the intra-tissular and intra-vascular evolution of the fungi. The diagnosis of this disease is asserted by the mycological and anatomo-pathological exams. The treatment is based on the antifungic and the surgical excision of necrotic tissues. We report three observations: one man (42 years) and two women (59 and 60 years). Diabetes was found in two cases. The diagnosis was in every case anatomo-pathologic. Our objective was to study the epidemiological and clinico-pathologic aspects of this serious affection and to discuss its prognosis.

Time since death and decomposition of the human body: variables and observations in case and experimental field studies.

PubMed

Mann, R W; Bass, W M; Meadows, L

1990-01-01

Much of the difficulty in determining the time since death stems from the lack of systematic observation and research on the decomposition rate of the human body. Continuing studies conducted at the University of Tennessee, Knoxville, provide useful information on the impact of carrion insect activity, ambient temperature, rainfall, clothing, burial and depth, carnivores, bodily trauma, body weight, and the surface with which the body is in contact. This paper reports findings and observations accumulated during eight years of research and case studies that may clarify some of the questions concerning bodily decay.

EXPLOSIVE EVENTS ON A SUBARCSECOND SCALE IN IRIS OBSERVATIONS: A CASE STUDY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Zhenghua; Xia, Lidong; Fu, Hui

We present a study of a typical explosive event (EE) at subarcsecond scale witnessed by strong non-Gaussian profiles with blue- and redshifted emission of up to 150 km s{sup –1} seen in the transition region Si IV 1402.8 Å, and the chromospheric Mg II k 2796.4 Å and C II 1334.5 Å observed by the Interface Region Imaging Spectrograph (IRIS) at unprecedented spatial and spectral resolution. For the first time an EE is found to be associated with very small-scale (∼120 km wide) plasma ejection followed by retraction in the chromosphere. These small-scale jets originate from a compact bright-point-like structure of ∼1.''5 size as seen in themore » IRIS 1330 Å images. SDO/AIA and SDO/HMI co-observations show that the EE lies in the footpoint of a complex loop-like brightening system. The EE is detected in the higher temperature channels of AIA 171 Å, 193 Å, and 131 Å, suggesting that it reaches a higher temperature of log T = 5.36 ± 0.06 (K). Brightenings observed in the AIA channels with durations 90-120 s are probably caused by the plasma ejections seen in the chromosphere. The wings of the C II line behave in a similar manner to the Si IV'S, indicating close formation temperatures, while the Mg II k wings show additional Doppler-shifted emission. Magnetic convergence or emergence followed by cancellation at a rate of 5 × 10{sup 14} Mx s{sup –1} is associated with the EE region. The combined changes of the locations and the flux of different magnetic patches suggest that magnetic reconnection must have taken place. Our results challenge several theories put forward in the past to explain non-Gaussian line profiles, i.e., EEs. Our case study on its own, however, cannot reject these theories; thus, further in-depth studies on the phenomena producing EEs are required.« less

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies.

PubMed

von Elm, Erik; Altman, Douglas G; Egger, Matthias; Pocock, Stuart J; Gøtzsche, Peter C; Vandenbroucke, Jan P

2014-12-01

Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Bias reduction in repeated-measures observational studies by the use of propensity score: the case of enteral sedation for critically ill patients.

PubMed

Umbrello, Michele; Mistraletti, Giovanni; Corbella, Davide; Cigada, Marco; Salini, Silvia; Morabito, Alberto; Iapichino, Gaetano

2012-12-01

Within the evidence-based medicine paradigm, randomized controlled trials represent the "gold standard" to produce reliable evidence. Indeed, planning and implementing randomized controlled trials in critical care medicine presents limitations because of intrinsic and structural problems. As a consequence, observational studies still occur frequently. In these cases, propensity score (PS) (probability of receiving a treatment conditional on observed covariates) is an increasingly used technique to adjust the results. Few studies addressed the specific issue of a PS correction of repeated-measures designs. Three techniques for correcting the analysis of nonrandomized designs (matching, stratification, regression adjustment) are presented in a tutorial form and applied to a real case study: the comparison between intravenous and enteral sedative therapy in the intensive care unit setting. After showing the results before and after the use of PS, we suggest that such a tool allows to partially overcoming the bias associated with the observational nature of the study. It permits to correct the estimates for any observed covariate, while unobserved confounders cannot be controlled for. Propensity score represents a useful additional tool to estimate the effects of treatments in nonrandomized studies. In the case study, an enteral sedation approach was equally effective to an intravenous regime, allowing for a lower level of sedation and spare of resources. Copyright © 2012 Elsevier Inc. All rights reserved.

Real-Life Case Studies for Teachers.

ERIC Educational Resources Information Center

Hayes, William

Case studies described in this book reflect conditions present in today's public schools. Situations described in these case studies are intended to introduce education students to the variety of problems existing in today's schools. The 38 case studies highlight: student cheating; teacher's observation by administrator; inclusion; contract…

Satellite observed impacts of wildfires on regional atmosphere composition and shortwave radiative forcing: multiple cases study

NASA Astrophysics Data System (ADS)

Fu, Y.; Li, R.; Huang, J.; Bergeron, Y.; Fu, Y.

2017-12-01

Emissions of aerosols and trace gases from wildfires and the direct shortwave radiative forcing were studied using multi-satellite/sensor observations from Aqua Moderate-Resolution Imaging Spectroradiometer (MODIS), Aqua Atmospheric Infrared Sounder (AIRS), Aura Ozone Monitoring Instrument (OMI), and Aqua Cloud's and the Earth's Radiant Energy System (CERES). The selected cases occurred in Northeast of China (NEC), Siberia of Russia, California of America have dominant fuel types of cropland, mixed forest and needleleaf forest, respectively. The Fire radiative power (FRP) based emission coefficients (Ce) of aerosol, NOx (NO2+NO), formaldehyde (HCHO), and carbon monoxide (CO) showed significant differences from case to case. 1) the FRP of the cropland case in NEC is strongest, however, the Ce of aerosol is the lowest (20.51 ± 2.55 g MJ-1). The highest Ce of aerosol is 71.34 ± 13.24 g MJ-1 in the needleleaf fire case in California. 2) For NOx, the highest Ce existed in the cropland case in NEC (2.76 ± 0.25 g MJ-1), which is more than three times of those in the forest fires in Siberia and California. 3) The Ce of CO is 70.21±10.97 and 88.38±46.16 g MJ-1 in the forest fires in Western Siberia and California, which are about four times of that in cropland fire. 4) The variation of Ce of HCHO are relatively small among cases. Strong spatial correlations are found among aerosol optical depth (AOD), NOx, HCHO, and CO. The ratios of NOx to AOD, HCHO, and CO in the cropland case in NEC show much higher values than those in other cases. Although huge differences of emissions and composition ratios exist among cases, the direct shortwave (SW) radiative forcing efficiency (SWARFE) of smoke at the top of the atmosphere (TOA) are in good agreement, with the shortwave radiative forcing efficiencies values of 20.09 to 22.93 per unit AOD. Results in this study reveal noteworthy variations of the FRP-based emissions coefficient and relative chemical composition in the smoke

Statistical Analysis of Sport Movement Observations: the Case of Orienteering

NASA Astrophysics Data System (ADS)

Amouzandeh, K.; Karimipour, F.

2017-09-01

Study of movement observations is becoming more popular in several applications. Particularly, analyzing sport movement time series has been considered as a demanding area. However, most of the attempts made on analyzing movement sport data have focused on spatial aspects of movement to extract some movement characteristics, such as spatial patterns and similarities. This paper proposes statistical analysis of sport movement observations, which refers to analyzing changes in the spatial movement attributes (e.g. distance, altitude and slope) and non-spatial movement attributes (e.g. speed and heart rate) of athletes. As the case study, an example dataset of movement observations acquired during the "orienteering" sport is presented and statistically analyzed.

Modified directly observed treatment for tuberculosis versus self-administered therapy: an observational study in rural Greece.

PubMed

Charokopos, N; Tsiros, G; Foka, A; Voila, P; Chrysanthopoulos, K; Spiliopoulou, I; Jelastopulu, E

2013-01-01

Directly Observed Treatment (DOT) is the key element of DOTS (directly observed treatment, short course), part of the internationally recommended control strategy for tuberculosis (TB). The evaluation of DOT has not been widely evaluated in rural areas in developed settings. The aim of this pilot study was to evaluate a modified DOT program (MDOT) by a general practitioner (GP) in a rural area of southwest Greece, where there is substantial underreporting of TB cases. Thirteen new TB cases with 30 close contacts were compared with 41 past-treated TB subjects (controls) with 111 close contacts in this observational, case-control study. Home visits by a GP were conducted and comparison of various data (laboratory findings, treatment outcomes, questionnaire-based parameters, on-site recorded conditions) was performed in both newly detected pulmonary TB cases and previously treated TB cases managed without DOT intervention. MDOT by GP implementation revealed that 11 cases (84.6%) were successfully treated, one (7.7%) case died, and one (7.7%) was lost to follow up. None of the close contacts of new TB cases was infected with active TB, while 6.3% of previously-treated TB subjects were infected with active TB and had to receive a complete anti-TB regimen. Chemoprophylaxis was administered to 13.3% of close contacts of new cases; whereas 12.6% of close contacts of previously-treated patients received chemoprophylaxis. This pilot study revealed that a GP is able to implement a program based on DOT resulting in high treatment adherence and prevention of TB compared with the conventional self-administration of treatment.

Medication safety research by observational study design.

PubMed

Lao, Kim S J; Chui, Celine S L; Man, Kenneth K C; Lau, Wallis C Y; Chan, Esther W; Wong, Ian C K

2016-06-01

Observational studies have been recognised to be essential for investigating the safety profile of medications. Numerous observational studies have been conducted on the platform of large population databases, which provide adequate sample size and follow-up length to detect infrequent and/or delayed clinical outcomes. Cohort and case-control are well-accepted traditional methodologies for hypothesis testing, while within-individual study designs are developing and evolving, addressing previous known methodological limitations to reduce confounding and bias. Respective examples of observational studies of different study designs using medical databases are shown. Methodology characteristics, study assumptions, strengths and weaknesses of each method are discussed in this review.

Lower thermospheric-enhanced sodium layers observed at low latitude and possible formation: Case studies

NASA Astrophysics Data System (ADS)

Xue, X. H.; Dou, X. K.; Lei, J.; Chen, J. S.; Ding, Z. H.; Li, T.; Gao, Q.; Tang, W. W.; Cheng, X. W.; Wei, K.

2013-05-01

We report two lower thermospheric-enhanced sodium layer (TeSL) cases observed at a low-latitude station, Lijiang, China (26.7°N, 100.0°E), on 10 March and 10 April 2012, respectively. The TeSLs in the two cases were located at altitudes near 122 and 112 km, respectively. In addition, strong sporadic sodium layers (SSLs) near 100 km accompanied the TeSL observed on 10 March 2012. Both the TeSLs and SSLs exhibited tidal-induced downward motion. The adjacent ground-based and space-borne ionospheric radio observations showed strong Es layers before the appearance of the TeSLs, suggesting an " Es- TeSLs (SSLs)" chain formed through the tidal wind shear mechanism. Assuming that the vertical tidal wavelengths remain unchanged, it is found that in different regions caused by the tidal wind shear, different TeSLs evolution processes are expected: (1) in a tidal-convergence region, a TeSL/SSL with a downward propagation phase is enhanced due to a rapid decrease in the Na+lifetime at the lower altitude; (2) in an ion convergence-divergence interface region, a TeSL/SSL will still follow the tidal downward phase progression, but sodium density does not exhibit evident enhancement; and (3) when a TeSL/SSL enters into a tidal wind-divergence zone, the layer density tends to decrease.

The dynamic cusp at low altitudes: A case study combining Viking, DMSP, and Sondrestrom incoherent scatter radar observations

NASA Technical Reports Server (NTRS)

Watermann, Jurgen; Delabeaujardiere, Odile; Lummerzheim, Dirk; Woch, Joachim; Newell, Patrick T.; Potemra, Thomas A.; Rich, Frederick J.; Shapshak, Mans

1992-01-01

A case study involving data from three satellites and a ground-based radar are presented. Focus is on a detailed discussion of observations of the dynamic cusp made on 24 Sep. 1986 in the dayside high-latitude ionosphere and interior magnetosphere. The relevant data from space-borne and ground-based sensors is presented. They include in-situ particle and field measurements from the DMSP-F7 and Viking spacecraft and Sondrestrom radar observations of the ionosphere. These data are augmented by observations of the IMF and the solar wind plasma. The observations are compared with predictions about the ionospheric response to the observed particle precipitation, obtained from an auroral model. It is shown that observations and model calculations fit well and provide a picture of the ionospheric footprint of the cusp in an invariant latitude versus local time frame. The combination of Viking, Sondrestrom radar, and IMP-8 data suggests that we observed an ionospheric signature of the dynamic cusp. Its spatial variation over time which appeared closely related to the southward component of the IMF was monitored.

An Observational Case Study of Persistent Fog and Comparison with an Ensemble Forecast Model

NASA Astrophysics Data System (ADS)

Price, Jeremy; Porson, Aurore; Lock, Adrian

2015-05-01

We present a study of a persistent case of fog and use the observations to evaluate the UK Met Office ensemble model. The fog appeared to form initially in association with small patches of low-level stratus and spread rapidly across southern England during 11 December 2012, persisting for 24 h. The low visibility and occurrence of fog associated with the event was poorly forecast. Observations show that the surprisingly rapid spreading of the layer was due to a circulation at the fog edge, whereby cold cloudy air subsided into and mixed with warmer adjacent clear air. The resulting air was saturated, and hence the fog layer grew rapidly outwards from its edge. Measurements of fog-droplet deposition made overnight show that an average of 12 g m h was deposited but that the liquid water content remained almost constant, indicating that further liquid was condensing at a similar rate to the deposition, most likely due to the slow cooling. The circulation at the fog edge was also present during its dissipation, by which time the fog top had lowered by 150 m. During this period the continuing circulation at the fog edge, and increasing wind shear at fog top, acted to dissipate the fog by creating mixing with, by then, the drier adjacent and overlying air. Comparisons with a new, high resolution Met Office ensemble model show that this type of case remains challenging to simulate. Most ensemble members successfully simulated the formation and persistence of low stratus cloud in the region, but produced too much cloud initially overnight, which created a warm bias. During the daytime, ensemble predictions that had produced fog lifted it into low stratus, whilst in reality the fog remained present all day. Various aspects of the model performance are discussed further.

User-friendly tools on handheld devices for observer performance study

NASA Astrophysics Data System (ADS)

Matsumoto, Takuya; Hara, Takeshi; Shiraishi, Junji; Fukuoka, Daisuke; Abe, Hiroyuki; Matsusako, Masaki; Yamada, Akira; Zhou, Xiangrong; Fujita, Hiroshi

2012-02-01

ROC studies require complex procedures to select cases from many data samples, and to set confidence levels in each selected case to generate ROC curves. In some observer performance studies, researchers have to develop software with specific graphical user interface (GUI) to obtain confidence levels from readers. Because ROC studies could be designed for various clinical situations, it is difficult task for preparing software corresponding to every ROC studies. In this work, we have developed software for recording confidence levels during observer studies on tiny personal handheld devices such as iPhone, iPod touch, and iPad. To confirm the functions of our software, three radiologists performed observer studies to detect lung nodules by using public database of chest radiograms published by Japan Society of Radiological Technology. The output in text format conformed to the format for the famous ROC kit from the University of Chicago. Times required for the reading each case was recorded very precisely.

Using Case Studies to Enrich Field Experience.

ERIC Educational Resources Information Center

Florio-Ruane, Susan; Clark, Christopher M.

1990-01-01

This paper discusses the use of field experience in teacher education and how it can be augmented by phenomenological case studies. It summarizes a particular case study involving three teacher education classes, noting that reflective analysis of cases can prepare students to observe in the field. (SM)

Representing Geospatial Environment Observation Capability Information: A Case Study of Managing Flood Monitoring Sensors in the Jinsha River Basin

PubMed Central

Hu, Chuli; Guan, Qingfeng; Li, Jie; Wang, Ke; Chen, Nengcheng

2016-01-01

Sensor inquirers cannot understand comprehensive or accurate observation capability information because current observation capability modeling does not consider the union of multiple sensors nor the effect of geospatial environmental features on the observation capability of sensors. These limitations result in a failure to discover credible sensors or plan for their collaboration for environmental monitoring. The Geospatial Environmental Observation Capability (GEOC) is proposed in this study and can be used as an information basis for the reliable discovery and collaborative planning of multiple environmental sensors. A field-based GEOC (GEOCF) information representation model is built. Quintuple GEOCF feature components and two GEOCF operations are formulated based on the geospatial field conceptual framework. The proposed GEOCF markup language is used to formalize the proposed GEOCF. A prototype system called GEOCapabilityManager is developed, and a case study is conducted for flood observation in the lower reaches of the Jinsha River Basin. The applicability of the GEOCF is verified through the reliable discovery of flood monitoring sensors and planning for the collaboration of these sensors. PMID:27999247

Representing Geospatial Environment Observation Capability Information: A Case Study of Managing Flood Monitoring Sensors in the Jinsha River Basin.

PubMed

Hu, Chuli; Guan, Qingfeng; Li, Jie; Wang, Ke; Chen, Nengcheng

2016-12-16

Sensor inquirers cannot understand comprehensive or accurate observation capability information because current observation capability modeling does not consider the union of multiple sensors nor the effect of geospatial environmental features on the observation capability of sensors. These limitations result in a failure to discover credible sensors or plan for their collaboration for environmental monitoring. The Geospatial Environmental Observation Capability (GEOC) is proposed in this study and can be used as an information basis for the reliable discovery and collaborative planning of multiple environmental sensors. A field-based GEOC (GEOCF) information representation model is built. Quintuple GEOCF feature components and two GEOCF operations are formulated based on the geospatial field conceptual framework. The proposed GEOCF markup language is used to formalize the proposed GEOCF. A prototype system called GEOCapabilityManager is developed, and a case study is conducted for flood observation in the lower reaches of the Jinsha River Basin. The applicability of the GEOCF is verified through the reliable discovery of flood monitoring sensors and planning for the collaboration of these sensors.

State funding for local public health: observations from six case studies.

PubMed

Potter, Margaret A; Fitzpatrick, Tiffany

2007-01-01

The purpose of this study is to describe state funding of local public health within the context of state public health system types. These types are based on administrative relationships, legal structures, and relative proportion of state funding in local public health budgets. We selected six states representing various types and geographic regions. A case study for each state summarized available information and was validated by state public health officials. An analysis of the case studies reveals that the variability of state public health systems--even within a given type--is matched by variability in approaches to funding local public health. Nevertheless, some meaningful associations appear. For example, higher proportions of state funding occur along with higher levels of state oversight and the existence of local service mandates in state law. These associations suggest topics for future research on public health financing in relation to local accountability, local input to state priority-setting, mandated local services, and the absence of state funds for public health services in some local jurisdictions.

Implementation of case studies in undergraduate didactic nursing courses: a qualitative study.

PubMed

Dutra, Danette K

2013-07-04

The implementation of unfolding scenario-based case studies in the didactic classroom is associated with learner-centered education. The utilization of learner-centered pedagogies, such as case studies, removes the focus from the instructor and instead places it on the student. Learner-centered pedagogies are believed to improve students' levels of cognition. The purpose of this study was to examine how nurse educators are implementing the pedagogies of case studies in their undergraduate didactic courses. The goal was to examine, document, report, and, ultimately, implement the strategies. Purposeful sampling was utilized in this qualitative, multisite-designed study. For each of the four participants, three separate site visits were completed. Observations and post-observational interviews took place at each site visit. Transcribed data from interviews, observations, and course documents were imported into the computer program Nvivo8. Repetitive comparative analysis was utilized to complete the data coding process. The guiding research question of this study sought to investigate the implementation strategies of case studies in didactic nursing courses. The implementation of case studies by the participants reflected two primary patterns: Formal Implementation (FI) and Informal Implementation (II) of case studies. The FI of case studies was further divided into two subcategories: Formal Implementation of case studies used Inside the Classroom setting (FIIC) and Formal Implementation of cases studies used Outside of the Classroom (FIOC). Results of this investigation have led to an increased understanding of implementation strategies of unfolding scenario-based case studies in undergraduate nursing didactic courses. Data collected were rich in the description of specific methodologies for utilization of case studies and may serve as a resource for faculty in development of creative strategies to enhance the didactic classroom experience.

Implementation of case studies in undergraduate didactic nursing courses: a qualitative study

PubMed Central

2013-01-01

Background The implementation of unfolding scenario-based case studies in the didactic classroom is associated with learner-centered education. The utilization of learner-centered pedagogies, such as case studies, removes the focus from the instructor and instead places it on the student. Learner-centered pedagogies are believed to improve students’ levels of cognition. The purpose of this study was to examine how nurse educators are implementing the pedagogies of case studies in their undergraduate didactic courses. The goal was to examine, document, report, and, ultimately, implement the strategies. Methods Purposeful sampling was utilized in this qualitative, multisite-designed study. For each of the four participants, three separate site visits were completed. Observations and post-observational interviews took place at each site visit. Transcribed data from interviews, observations, and course documents were imported into the computer program Nvivo8. Repetitive comparative analysis was utilized to complete the data coding process. Results The guiding research question of this study sought to investigate the implementation strategies of case studies in didactic nursing courses. The implementation of case studies by the participants reflected two primary patterns: Formal Implementation (FI) and Informal Implementation (II) of case studies. The FI of case studies was further divided into two subcategories: Formal Implementation of case studies used Inside the Classroom setting (FIIC) and Formal Implementation of cases studies used Outside of the Classroom (FIOC). Conclusion Results of this investigation have led to an increased understanding of implementation strategies of unfolding scenario-based case studies in undergraduate nursing didactic courses. Data collected were rich in the description of specific methodologies for utilization of case studies and may serve as a resource for faculty in development of creative strategies to enhance the didactic

Case-control studies in neurosurgery.

PubMed

Nesvick, Cody L; Thompson, Clinton J; Boop, Frederick A; Klimo, Paul

2014-08-01

Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting. The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure

A rare case of haboob in Tehran: Observational and numerical study

NASA Astrophysics Data System (ADS)

Karami, S.; Ranjbar, A.; Mohebalhojeh, A. R.; Moradi, M.

2017-03-01

A great dust storm occurred in Tehran on 2 June 2014 and caused severe damage to properties and involved loss of human life. From the visual evidence available, it can be regarded as a case of haboob. As a lower latitude phenomenon, its occurrence in Tehran was unprecedented in the last 50 years. This paper aims to present a detailed analysis of the weather conditions, the pathways by which dust particles were ingested by the haboob, as well as the impact of the urban boundary layer on the intensity and propagation of the dust storm. Using numerical simulation carried out by the WRF-Chem model and various observational techniques, the coupling of a low-level small-scale deformation field with a lower-tropospheric cold pool produced by precipitating mid-tropospheric clouds is identified as the main process involved in shaping this rare dust storm.

Wave-induced boundary-layer separation: A case study comparing airborne observations and results from a mesoscale model

NASA Astrophysics Data System (ADS)

Strauss, L.; Serafin, S.; Grubišić, V.

2012-04-01

Wave-induced boundary-layer separation (BLS) results from the adverse-pressure gradient forces that are exerted on the atmospheric boundary-layer by internal gravity waves in flow over orography. BLS has received significant attention in recent years, particularly so, because it is a key ingredient in the formation of atmospheric rotors. Traditionally depicted as horizontal eddies in the lee of mountain ranges, rotors originate from the interaction between internal gravity waves and the atmospheric boundary-layer. Our study focuses on the first observationally documented case of wave-induced BLS, which occurred on 26 Jan 2006 in the lee of the Medicine Bow Mountains in SE Wyoming (USA). Observations from the University of Wyoming King Air (UWKA) aircraft, in particular, the remote sensing measurements with the Wyoming Cloud Radar (WCR), reveal strong wave activity, downslope winds in excess of 30 m/s, and near-surface flow reversal in the lee of the mountain range. The fine resolution of WCR data (on the order of 40x40 m2 for two-dimensional velocity fields) exhibits fine-scale vortical structures ("subrotors") which are embedded within the main rotor zone. Our case study intends to complete the characterisation of the observed boundary-layer separation event. Modelling of the event with the mesoscale Weather Research and Forecast Model (WRF) provides insight into the mesoscale triggers of wave-induced BLS and turbulence generation. Indeed, the mesoscale model underpins the expected concurrence of the essential processes (gravity waves, wave breaking, downslope windstorms, etc.) leading to BLS. To exploit the recorded in situ and radar data to their full extent, a quantitative evaluation of the structure and intensity of turbulence is conducted by means of a power spectral analysis of the vertical wind component, measured along the flight track. An intercomparison of observational and modelling results serves the purpose of model verification and can shed some more

Case Study: Testing with Case Studies

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2015-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

Family Presence During Resuscitation (FPDR): Observational case studies of emergency personnel in Victoria, Australia.

PubMed

Porter, Joanne E; Miller, Nareeda; Giannis, Anita; Coombs, Nicole

2017-07-01

Family Presence During Resuscitation (FPDR), although not a new concept, remains inconsistently implemented by emergency personnel. Many larger metropolitan emergency departments (ED) have instigated a care coordinator role, however these personnel are often from a non-nursing background and have therefore limited knowledge about the clinical aspects of the resuscitation. In rural emergency departments there are simply not enough staff to allocate an independent role. A separate care coordinator role, who is assigned to care for the family and not take part in the resuscitation has been well documented as essential to the successful implementation of FPDR. One rural and one metropolitan emergency department in the state of Victoria, Australia were observed and data was collected on FPDR events. The participants consisted of resuscitation team members, including; emergency trained nurses, senior medical officers, general nurses and doctors. The participants were not told that the data would be recorded around interactions with family members or team discussions regarding family involvement in the resuscitation, following ethical approval involving limited disclosure of the aims of the study. Seventeen adult presentations (Metro n=9, Rural n=8) were included in this study and will be presented as resuscitation case studies. The key themes identified included ambiguity around resuscitation status, keeping the family informed, family isolation and inter-professional communication. During 17 adult resuscitation cases, staff were witnessed communicating with family, which was often limited and isolation resulted. Family were often uninformed or separated from their family member, however when a family liaison person was available it was found to be beneficial. This research indicated that staff could benefit from a designated family liaison role, formal policy and further education. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Expressive Bodily Movement Repertoire for Marimba Performance, Revealed through Observers' Laban Effort-Shape Analyses, and Allied Musical Features: Two Case Studies.

PubMed

Broughton, Mary C; Davidson, Jane W

2016-01-01

Musicians' expressive bodily movements can influence observers' perception of performance. Furthermore, individual differences in observers' music and motor expertise can shape how they perceive and respond to music performance. However, few studies have investigated the bodily movements that different observers of music performance perceive as expressive, in order to understand how they might relate to the music being produced, and the particular instrument type. In this paper, we focus on marimba performance through two case studies-one solo and one collaborative context. This study aims to investigate the existence of a core repertoire of marimba performance expressive bodily movements, identify key music-related features associated with the core repertoire, and explore how observers' perception of expressive bodily movements might vary according to individual differences in their music and motor expertise. Of the six professional musicians who observed and analyzed the marimba performances, three were percussionists and experienced marimba players. Following training, observers implemented the Laban effort-shape movement analysis system to analyze marimba players' bodily movements that they perceived as expressive in audio-visual recordings of performance. Observations that were agreed by all participants as being the same type of action at the same location in the performance recording were examined in each case study, then across the two studies. A small repertoire of bodily movements emerged that the observers perceived as being expressive. Movements were primarily allied to elements of the music structure, technique, and expressive interpretation, however, these elements appeared to be interactive. A type of body sway movement and more localized sound generating actions were perceived as expressive. These movements co-occurred and also appeared separately. Individual participant data revealed slightly more variety in the types and locations of actions

Effects of case management in community aged care on client and carer outcomes: a systematic review of randomized trials and comparative observational studies

PubMed Central

2012-01-01

Background Case management has been applied in community aged care to meet frail older people’s holistic needs and promote cost-effectiveness. This systematic review aims to evaluate the effects of case management in community aged care on client and carer outcomes. Methods We searched Web of Science, Scopus, Medline, CINAHL (EBSCO) and PsycINFO (CSA) from inception to 2011 July. Inclusion criteria were: no restriction on date, English language, community-dwelling older people and/or carers, case management in community aged care, published in refereed journals, randomized control trials (RCTs) or comparative observational studies, examining client or carer outcomes. Quality of studies was assessed by using such indicators as quality control, randomization, comparability, follow-up rate, dropout, blinding assessors, and intention-to-treat analysis. Two reviewers independently screened potentially relevant studies, extracted information and assessed study quality. A narrative summary of findings were presented. Results Ten RCTs and five comparative observational studies were identified. One RCT was rated high quality. Client outcomes included mortality (7 studies), physical or cognitive functioning (6 studies), medical conditions (2 studies), behavioral problems (2 studies) , unmet service needs (3 studies), psychological health or well-being (7 studies) , and satisfaction with care (4 studies), while carer outcomes included stress or burden (6 studies), satisfaction with care (2 studies), psychological health or well-being (5 studies), and social consequences (such as social support and relationships with clients) (2 studies). Five of the seven studies reported that case management in community aged care interventions significantly improved psychological health or well-being in the intervention group, while all the three studies consistently reported fewer unmet service needs among the intervention participants. In contrast, available studies reported mixed

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Observational Studies.

PubMed

Snyder, Graham M; Young, Heather; Varman, Meera; Milstone, Aaron M; Harris, Anthony D; Munoz-Price, Silvia

2016-10-01

Observational studies compare outcomes among subjects with and without an exposure of interest, without intervention from study investigators. Observational studies can be designed as a prospective or retrospective cohort study or as a case-control study. In healthcare epidemiology, these observational studies often take advantage of existing healthcare databases, making them more cost-effective than clinical trials and allowing analyses of rare outcomes. This paper addresses the importance of selecting a well-defined study population, highlights key considerations for study design, and offers potential solutions including biostatistical tools that are applicable to observational study designs. Infect Control Hosp Epidemiol 2016;1-6.

A genetic study of autism in Costa Rica: multiple variables affecting IQ scores observed in a preliminary sample of autistic cases.

PubMed

McInnes, L Alison; González, Patricia Jiménez; Manghi, Elina R; Esquivel, Marcela; Monge, Silvia; Delgado, Marietha Fallas; Fournier, Eduardo; Bondy, Pamela; Castelle, Kathryn

2005-03-21

Autism is a heritable developmental disorder of communication and socialization that has not been well studied in Hispanic populations. Therefore, we are collecting and evaluating all possible cases of autism from a population isolate in the Central Valley of Costa Rica (CVCR) for a clinical and genetic study. We are assessing all subjects and parents, as appropriate, using the newly translated Spanish versions of the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) as well as tests of intelligence and adaptive behavior. Detailed obstetric and family medical/psychiatric histories are taken. All cases are tested for Fragile X and will be extensively evaluated for cytogenetic abnormalities. To date we have obtained clinical evaluations on over 76 cases of possible autism referred to our study and report data for the initial 35 complete cases. The mean age of the probands is 6.7 years, and 31 of the 35 cases are male. Twenty-one of the cases have IQs <50 and only 6 cases have IQs > or = 70. Over half of the mothers had complications during pregnancy and/or delivery. No cases have tested positively for Fragile X or PKU. Chromosomal G-banding is not yet complete for all cases. Diagnostic data gathered on cases of autism in the CVCR using Spanish versions of the ADI-R and ADOS look similar to that generated by studies of English-speaking cases. However, only 17% of our cases have IQs within the normal range, compared to the figure of 25% seen in most studies. This result reflects an ascertainment bias in that only severe cases of autism come to treatment in the CVCR because there are no government-sponsored support programs or early intervention programs providing an incentive to diagnose autism. The severity of mental retardation seen in most of our cases may also be exaggerated by the lack of early intervention programs and the use of IQ tests without Costa Rican norms. Still, we must formally train healthcare providers

An Expressive Bodily Movement Repertoire for Marimba Performance, Revealed through Observers' Laban Effort-Shape Analyses, and Allied Musical Features: Two Case Studies

PubMed Central

Broughton, Mary C.; Davidson, Jane W.

2016-01-01

Musicians' expressive bodily movements can influence observers' perception of performance. Furthermore, individual differences in observers' music and motor expertise can shape how they perceive and respond to music performance. However, few studies have investigated the bodily movements that different observers of music performance perceive as expressive, in order to understand how they might relate to the music being produced, and the particular instrument type. In this paper, we focus on marimba performance through two case studies—one solo and one collaborative context. This study aims to investigate the existence of a core repertoire of marimba performance expressive bodily movements, identify key music-related features associated with the core repertoire, and explore how observers' perception of expressive bodily movements might vary according to individual differences in their music and motor expertise. Of the six professional musicians who observed and analyzed the marimba performances, three were percussionists and experienced marimba players. Following training, observers implemented the Laban effort-shape movement analysis system to analyze marimba players' bodily movements that they perceived as expressive in audio-visual recordings of performance. Observations that were agreed by all participants as being the same type of action at the same location in the performance recording were examined in each case study, then across the two studies. A small repertoire of bodily movements emerged that the observers perceived as being expressive. Movements were primarily allied to elements of the music structure, technique, and expressive interpretation, however, these elements appeared to be interactive. A type of body sway movement and more localized sound generating actions were perceived as expressive. These movements co-occurred and also appeared separately. Individual participant data revealed slightly more variety in the types and locations of actions

Rigour in qualitative case-study research.

PubMed

Houghton, Catherine; Casey, Dympna; Shaw, David; Murphy, Kathy

2013-03-01

To provide examples of a qualitative multiple case study to illustrate the specific strategies that can be used to ensure the credibility, dependability, confirmability and transferability of a study. There is increasing recognition of the valuable contribution qualitative research can make to nursing knowledge. However, it is important that the research is conducted in a rigorous manner and that this is demonstrated in the final research report. A multiple case study that explored the role of the clinical skills laboratory in preparing students for the real world of practice. Multiple sources of evidence were collected: semi-structured interviews (n=58), non-participant observations at five sites and documentary sources. Strategies to ensure the rigour of this research were prolonged engagement and persistent observation, triangulation, peer debriefing, member checking, audit trail, reflexivity, and thick descriptions. Practical examples of how these strategies can be implemented are provided to guide researchers interested in conducting rigorous case study research. While the flexible nature of qualitative research should be embraced, strategies to ensure rigour must be in place.

Improving observational study estimates of treatment effects using joint modeling of selection effects and outcomes: the case of AAA repair.

PubMed

O'Malley, A James; Cotterill, Philip; Schermerhorn, Marc L; Landon, Bruce E

2011-12-01

When 2 treatment approaches are available, there are likely to be unmeasured confounders that influence choice of procedure, which complicates estimation of the causal effect of treatment on outcomes using observational data. To estimate the effect of endovascular (endo) versus open surgical (open) repair, including possible modification by institutional volume, on survival after treatment for abdominal aortic aneurysm, accounting for observed and unobserved confounding variables. Observational study of data from the Medicare program using a joint model of treatment selection and survival given treatment to estimate the effects of type of surgery and institutional volume on survival. We studied 61,414 eligible repairs of intact abdominal aortic aneurysms during 2001 to 2004. The outcome, perioperative death, is defined as in-hospital death or death within 30 days of operation. The key predictors are use of endo, transformed endo and open volume, and endo-volume interactions. There is strong evidence of nonrandom selection of treatment with potential confounding variables including institutional volume and procedure date, variables not typically adjusted for in clinical trials. The best fitting model included heterogeneous transformations of endo volume for endo cases and open volume for open cases as predictors. Consistent with our hypothesis, accounting for unmeasured selection reduced the mortality benefit of endo. The effect of endo versus open surgery varies nonlinearly with endo and open volume. Accounting for institutional experience and unmeasured selection enables better decision-making by physicians making treatment referrals, investigators evaluating treatments, and policy makers.

Perioperative Management of Pregnant Women With Idiopathic Pulmonary Arterial Hypertension: An Observational Case Series Study From China.

PubMed

Zhang, Jinglan; Lu, Jiakai; Zhou, Xiaorui; Xu, Xuefeng; Ye, Qing; Ou, Qitan; Li, Yanna; Huang, Jiapeng

2018-03-07

The mortality of pregnant women with idiopathic pulmonary arterial hypertension (PAH) is very high. There are limited data on the management of idiopathic PAH during pregnancy. The authors aimed to examine systematically the characteristics of parturient women with idiopathic PAH, to explore the adverse effects of idiopathic PAH on pregnancy outcomes, and to report the multidisciplinary perioperative management strategy from the largest comprehensive cardiac hospital in China. Observational case series study. Tertiary referral acute care hospital in Beijing, China. The cases of 17 consecutive pregnant idiopathic PAH patients undergoing abortion or parturition at Anzhen Hospital were reviewed retrospectively. Preoperative characteristics, anesthesia method, intensive care management, PAH-specific therapy, and maternal and neonatal outcomes were analyzed in this case series study. Maternal and neonatal outcomes were the main measures. The mean ages of the 17 parturient women with idiopathic PAH were 28.3 ± 5.4 years, and the mean systolic pulmonary arterial pressure was 97.9 ± 18.6 mmHg. Fifteen patients (88.2%) received PAH-specific therapy before delivery, including sildenafil, iloprost, and treprostinil. All except 1 parturient received epidural anesthesia for surgery due to an emergency Caesarean section. Three patients experienced pulmonary hypertension crisis that necessitated conversion to general anesthesia. Ten parturients underwent Caesarean delivery at a median gestational age of 31 weeks. Three patients developed acute pulmonary hypertensive crisis intraoperatively. Two patients underwent cardiopulmonary resuscitation and extracorporeal membrane oxygenation support. The maternal mortality was 17.6% (3/17). Of the 10 delivered neonates, 9 (90.0%) survived. The maternal mortality of the idiopathic PAH parturient was high in this case series from China. The authors applied epidural anesthesia, early management with multidisciplinary approaches, PAH

Evaluating the Impact of Database Heterogeneity on Observational Study Results

PubMed Central

Madigan, David; Ryan, Patrick B.; Schuemie, Martijn; Stang, Paul E.; Overhage, J. Marc; Hartzema, Abraham G.; Suchard, Marc A.; DuMouchel, William; Berlin, Jesse A.

2013-01-01

Clinical studies that use observational databases to evaluate the effects of medical products have become commonplace. Such studies begin by selecting a particular database, a decision that published papers invariably report but do not discuss. Studies of the same issue in different databases, however, can and do generate different results, sometimes with strikingly different clinical implications. In this paper, we systematically study heterogeneity among databases, holding other study methods constant, by exploring relative risk estimates for 53 drug-outcome pairs and 2 widely used study designs (cohort studies and self-controlled case series) across 10 observational databases. When holding the study design constant, our analysis shows that estimated relative risks range from a statistically significant decreased risk to a statistically significant increased risk in 11 of 53 (21%) of drug-outcome pairs that use a cohort design and 19 of 53 (36%) of drug-outcome pairs that use a self-controlled case series design. This exceeds the proportion of pairs that were consistent across databases in both direction and statistical significance, which was 9 of 53 (17%) for cohort studies and 5 of 53 (9%) for self-controlled case series. Our findings show that clinical studies that use observational databases can be sensitive to the choice of database. More attention is needed to consider how the choice of data source may be affecting results. PMID:23648805

Case Study: Writing a Journal Case Study

ERIC Educational Resources Information Center

Prud'homme-Genereux, Annie

2016-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

Case-Cohort Studies: Design and Applicability to Hand Surgery.

PubMed

Vojvodic, Miliana; Shafarenko, Mark; McCabe, Steven J

2018-04-24

Observational studies are common research strategies in hand surgery. The case-cohort design offers an efficient and resource-friendly method for risk assessment and outcomes analysis. Case-cohorts remain underrepresented in upper extremity research despite several practical and economic advantages over case-control studies. This report outlines the purpose, utility, and structure of the case-cohort design and offers a sample research question to demonstrate its value to risk estimation for adverse surgical outcomes. The application of well-designed case-cohort studies is advocated in an effort to improve the quality and quantity of observational research evidence in hand and upper extremity surgery. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Monitoring Cirrus Clouds Using Lamp Observations in Association with Balloon-Borne Radiosonde Over Nainital: Few Case Studies

NASA Astrophysics Data System (ADS)

Solanki, R.; Singh, N.

2012-12-01

Upper tropospheric clouds such as cirrus have been identified as one of the important regulator of the radiation balance of the earth atmospheric-system. Though the satellite observation provide valuable information on cirrus clouds, they have limitations on spectral, temporal and spatial coverage, hence the need for local remote sensing, such as LiDAR a leading technique for studying the characteristics and properties of cirrus clouds. The upgraded version of a micro pulse LiDAR popularly known as LiDAR for Atmospheric Measurements and Probing (LAMP) developed by National Atmospheric Research Laboratory (NARL) is operational since October 2011, at ARIES Nainital (29.4oN, 79.5oE, ~2 km above the mean sea level) a high altitude location in the central Himalayas. Regular observations are being carried out in order to study the vertical distribution of aerosols, clouds and boundary layer structure etc. Altitude profiles of range corrected photon count and derived aerosol back scatter coefficients have depicted the occurrence of high altitude cirrus clouds/ ice clouds in an altitude range of 7 to 11 Km. Among the total observations in 27% of the cases the occurrence of cirrus clouds were detected. The corresponding cloud parameters such as temperature (-59 0C), horizontal wind speed (26 m/s), vertical wind speed (24 m/s), Relative Humidity (61%), at a height (~9 Km) were measured with Radiosonde observations. The prevailing region for cirrus cloud is found to be highly turbulent, indicating the region of divergence followed by a convergence, showing the favorable conditions for cirrus cloud formation. Optical and geometrical characteristics of Cirrus clouds have been analyzed using LiDAR and radiosonde measurements. The temperature and thickness dependence of optical properties have also been studied. The results will be further substantiated with CALIPSO satellite and details will be discussed during the presentation.

Observational studies are complementary to randomized controlled trials.

PubMed

Grootendorst, Diana C; Jager, Kitty J; Zoccali, Carmine; Dekker, Friedo W

2010-01-01

Randomized controlled trials (RCTs) are considered the gold standard study design to investigate the effect of health interventions, including treatment. However, in some situations, it may be unnecessary, inappropriate, impossible, or inadequate to perform an RCT. In these special situations, well-designed observational studies, including cohort and case-control studies, may provide an alternative to doing nothing in order to obtain estimates of treatment effect. It should be noted that such studies should be performed with caution and correctly. The aims of this review are (1) to explain why RCTs are considered the optimal study design to evaluate treatment effects, (2) to describe the situations in which an RCT is not possible and observational studies are an adequate alternative, and (3) to explain when randomization is not needed and can be approximated in observational studies. Examples from the nephrology literature are used for illustration. Copyright 2009 S. Karger AG, Basel.

Case Study: Interventions for an ADHD Student

ERIC Educational Resources Information Center

Hartlep, Nicholas Daniel

2009-01-01

This case study was done in partial fulfillment of a Master of Science in Education (M.S.Ed.) Graduate Course the participant-observer was completing. The participant-observer learned a lot about Dmitrov, the child in this study. Dmitrov was a 2nd-grade student who was diagnosed (late in the school year) with Attention Deficit Hyperactivity…

Evaluation of Multiclass Model Observers in PET LROC Studies

NASA Astrophysics Data System (ADS)

Gifford, H. C.; Kinahan, P. E.; Lartizien, C.; King, M. A.

2007-02-01

A localization ROC (LROC) study was conducted to evaluate nonprewhitening matched-filter (NPW) and channelized NPW (CNPW) versions of a multiclass model observer as predictors of human tumor-detection performance with PET images. Target localization is explicitly performed by these model observers. Tumors were placed in the liver, lungs, and background soft tissue of a mathematical phantom, and the data simulation modeled a full-3D acquisition mode. Reconstructions were performed with the FORE+AWOSEM algorithm. The LROC study measured observer performance with 2D images consisting of either coronal, sagittal, or transverse views of the same set of cases. Versions of the CNPW observer based on two previously published difference-of-Gaussian channel models demonstrated good quantitative agreement with human observers. One interpretation of these results treats the CNPW observer as a channelized Hotelling observer with implicit internal noise

Collaborative Assessment: Middle School Case Study

ERIC Educational Resources Information Center

Parkison, Paul T.

2014-01-01

Utilizing a participant observer research model, a case study of the efficacy of a collaborative assessment methodology within a middle school social studies class was conducted. A review of existing research revealed that students' perceptions of assessment, evaluation, and accountability influence their intrinsic motivation to learn. A…

Directly observed treatment short-course (DOTS) for treatment of new tuberculosis cases in Somali Regional State, Eastern Ethiopia: ten years retrospective study.

PubMed

Woldeyohannes, Desalegn; Sisay, Solomon; Mengistu, Belete; Kassa, Hiwot

2015-08-19

A third of the world population is infected with tuberculosis (TB) bacilli. TB accounts for 25% of all avoidable deaths in developing countries. The objective of the study was to assess impact of directly observed treatment short-course (DOTS) strategy on new tuberculosis case finding and treatment outcomes in Somali Regional State, Ethiopia from 2003 up to 2012 and from 2004 up to 2013, respectively. A health facility based retrospective study was employed. Quarterly reports were collected using World Health Organization (WHO) reporting format for TB case finding and treatment outcome from all zones in the region to the Federal Ministry of Health. A total of 31, 198 all types of new TB cases were registered and reported during the period from 2003 up to 2012, in the region. Out of these, smear positive pulmonary TB cases were 12,466 (40%), and 10,537 (33.8%) and 8195 (26.2%) for smear negative pulmonary TB and extra-pulmonary TB cases, respectively. An average case detection rate (CDR) of 19.1% (SD 3.6) and treatment success rate (TSR) of 85.5% (SD 5.0) for smear positive pulmonary TB were reported for the specified years period. For the overall study period, trend chi-squire analysis for CDR was X(2) = 2.1; P > 0.05 and X(2) = 5.64; P < 0.05 for TSR. The recommended TSR set by WHO was achieved (85.5%) and the CDR reported was far below (19.1%) from the recommended target. Extensive efforts should be established to maintain the achieved TSR and to increase the low CDR for the smear positive pulmonary TB cases through implementing alternative case finding strategies.

Using full-cohort data in nested case-control and case-cohort studies by multiple imputation.

PubMed

Keogh, Ruth H; White, Ian R

2013-10-15

In many large prospective cohorts, expensive exposure measurements cannot be obtained for all individuals. Exposure-disease association studies are therefore often based on nested case-control or case-cohort studies in which complete information is obtained only for sampled individuals. However, in the full cohort, there may be a large amount of information on cheaply available covariates and possibly a surrogate of the main exposure(s), which typically goes unused. We view the nested case-control or case-cohort study plus the remainder of the cohort as a full-cohort study with missing data. Hence, we propose using multiple imputation (MI) to utilise information in the full cohort when data from the sub-studies are analysed. We use the fully observed data to fit the imputation models. We consider using approximate imputation models and also using rejection sampling to draw imputed values from the true distribution of the missing values given the observed data. Simulation studies show that using MI to utilise full-cohort information in the analysis of nested case-control and case-cohort studies can result in important gains in efficiency, particularly when a surrogate of the main exposure is available in the full cohort. In simulations, this method outperforms counter-matching in nested case-control studies and a weighted analysis for case-cohort studies, both of which use some full-cohort information. Approximate imputation models perform well except when there are interactions or non-linear terms in the outcome model, where imputation using rejection sampling works well. Copyright © 2013 John Wiley & Sons, Ltd.

Efficacy of sublingual specific immunotherapy in intermittent and persistent allergic rhinitis in children: an observational case-control study on 171 patients. The EFESO-children multicenter trial.

PubMed

Acquistapace, Franca; Agostinis, Fabio; Castella, Vincenzo; Kantar, Ahmad; Novembre, Elio; Perrone, Maria Rosaria; Pietrasanta, Michele; Sambugaro, Renato; Milani, Massimo

2009-11-01

Sublingual-specific immunotherapy (SLIT) is considered as a valid treatment of respiratory allergies. However, there are few data on large sample size regarding its clinical role in 'real life' in term of reduction of symptoms, rescue medications and prevention of asthma in patients suffering from allergic rhinitis (AR) especially in children. We performed a multicenter, case-control study to evaluate the effect of SLIT in children (age 6-18 yr) with intermittent or persistent AR. 171 children (27% girls and 73% boys) with AR due to seasonal or perennial allergens were enrolled in a multicenter case-control study. Cases (n = 90) were defined as patients with intermittent (64%) or persistent (36%) AR who were treated for at least two consecutive years with specific SLIT with the related allergen extracts (SLITone ALK-Abellò). Controls (n = 81) were defined as sex-age- and type of allergen matched AR children who were never treated with specific immunotherapy and had no asthmatic symptoms at the beginning of observation period. Main outcomes of the study were the rhinoconjunctivitis symptom score (SS) (sneezing, rhinorrea, nasal itch, congestion, ocular itch and watery eyes) with a ranging scale from 0 (=no symptoms) to 3 (=severe symptoms) and the medication score (MS) evaluating symptomatic drug intake (antihystamine and inhaled corticosteroids). SS and MS were evaluated at the end of the observational period in relation with the period, considering the last 12 months, in which patients suffered the highest symptoms levels (i.e., peak of relevant pollen season (seasonal AR) or during the period of maximum allergen exposure in case of perennial AR). Secondary outcome of the study was the development of asthma symptoms during the observation period. SS (mean +/- SD) was 4.5 +/- 2.5 in cases and 9.0 +/- 3.0 in controls (-50%) (p = 0.0001). MS (mean +/- SD) was 2.5 +/- 1.9 and 3.6 +/- 2.1 in the case and control groups, respectively (-31%) (p = 0.0001). At the end of

Lidar observation of transition of cirrus clouds over a tropical station Gadanki (13.45° N, 79.18° E): case studies

NASA Astrophysics Data System (ADS)

Srinivasan, M. A.; Rao, C. Dhananjaya; Krishnaiah, M.

2016-05-01

The present study describes Mie lidar observations of the cirrus cloud passage showing transition between double thin layers into single thick and single thick layer into double thin layers of cirrus over Gadanki region. During Case1: 17 January 2007, Case4: 12 June 2007, Case5: 14 July 2007 and Case6: 24 July 2007 the transition is found to from two thin cirrus layers into single geometrically thick layer. Case2: 14 May 2007 and Case3: 15 May 2007, the transition is found to from single geometrically thick layer into two thin cirrus layers. Linear Depolarization Ratio (LDR) and Back Scatter Ration (BSR) are found to show similar variation with strong peaks during transition; both LDR and Cloud Optical Depth (COD) is found to show similar variation except during transition with strong peaks in COD which is not clearly found from LDR for the all cases. There is a significant weakening of zonal and meridional winds during Case1 which might be due to the transition from multiple to single thick cirrus indicating potential capability of thick cirrus in modulating the wind fields. There exists strong upward wind dominance contributed to significant ascent in cloud-base altitude thereby causing transition of multiple thin layers into single thick cirrus.

An Observational Study of Antibiotic Prescribing Behavior and the Hawthorne Effect

PubMed Central

Mangione-Smith, Rita; Elliott, Marc N; McDonald, Laurie; McGlynn, Elizabeth A

2002-01-01

Objectives To assess whether prospective, observational study procedures, including questionnaires and audio recording, are associated with different patterns of physician diagnostic decision making and antibiotic prescribing. Data Sources/Setting (1) Survey data from a prospective observational study of treatment patterns for children with acute upper respiratory illnesses (10/96–3/97) and (2) retrospective medical record abstraction data of nonobserved encounters for the same problems occurring during (10/96–3/97) and one year after (10/97–3/98) the observational study period. Ten pediatricians in two community practices were studied. Study Design Patterns of diagnoses recorded in the medical record and antibiotics ordered for visits occurring outside of the observational study (same time period and one year later) were compared with the pattern of diagnoses and antibiotics ordered during the observational study. Data Collection/Extraction Methods For the observational study (10/96–2/97), diagnosis and treatment choices were obtained from questionnaires completed by physicians immediately following the visit. For the nonstudy encounters (10/96–3/97 and 10/97–3/98), data were abstracted from medical records one year after the observational study was completed. Principal Findings The proportion of viral cases in which an antibiotic was prescribed was 29 percentage points lower for the observational study compared to the retrospective analysis (p <.05). In one of two study sites, the proportion of cases assigned a bacterial diagnosis was 29 percentage points lower in the observational study period compared to the retrospective study (p <.05). Conclusions Observational study procedures including questionnaires and audio recording can affect antibiotic prescribing behavior. Future observational studies aimed at examining the frequency of inappropriate antibiotic prescribing should measure and adjust for the Hawthorne effect; without such adjustments, the

Do Case Rates Affect Physicians' Clinical Practice in Radiation Oncology?: An Observational Study

PubMed Central

Loy, Bryan A.; Shkedy, Clive I.; Powell, Adam C.; Happe, Laura E.; Royalty, Julie A.; Miao, Michael T.; Smith, Gary L.; Long, James W.; Gupta, Amit K.

2016-01-01

Case rate payments combined with utilization monitoring may have the potential to improve the quality of care by reducing over and under-treatment. Thus, a national managed care organization introduced case rate payments at one multi-site radiation oncology provider while maintaining only fee-for-service payments at others. This study examined whether the introduction of the payment method had an effect on radiation fractions administered when compared to clinical guidelines. The number of fractions of radiation therapy delivered to patients with bone metastases, breast, lung, prostate, and skin cancer was assessed for concordance with clinical guidelines. The proportion of guideline-based care ascertained from the payer's claims database was compared before (2011) and after (2013) the payment method introduction using relative risks (RR). After the introduction of case rates, there were no significant changes in guideline-based care in breast, lung, and skin cancer; however, patients with bone metastases and prostate cancer were significantly more likely to have received guideline-based care (RR = 2.0 and 1.1, respectively, p<0.05). For the aggregate of all cancers, the under-treatment rate significantly declined (p = 0.008) from 4% to 0% after the introduction of case rate payments, while the over-treatment rate remained steady at 9%, with no significant change (p = 0.20). These findings suggest that the introduction of case rate payments did not adversely affect the rate of guideline-based care at the provider examined. Additional research is needed to isolate the effect of the payment model and assess implications in other populations. PMID:26870963

Do Case Rates Affect Physicians' Clinical Practice in Radiation Oncology?: An Observational Study.

PubMed

Loy, Bryan A; Shkedy, Clive I; Powell, Adam C; Happe, Laura E; Royalty, Julie A; Miao, Michael T; Smith, Gary L; Long, James W; Gupta, Amit K

2016-01-01

Case rate payments combined with utilization monitoring may have the potential to improve the quality of care by reducing over and under-treatment. Thus, a national managed care organization introduced case rate payments at one multi-site radiation oncology provider while maintaining only fee-for-service payments at others. This study examined whether the introduction of the payment method had an effect on radiation fractions administered when compared to clinical guidelines. The number of fractions of radiation therapy delivered to patients with bone metastases, breast, lung, prostate, and skin cancer was assessed for concordance with clinical guidelines. The proportion of guideline-based care ascertained from the payer's claims database was compared before (2011) and after (2013) the payment method introduction using relative risks (RR). After the introduction of case rates, there were no significant changes in guideline-based care in breast, lung, and skin cancer; however, patients with bone metastases and prostate cancer were significantly more likely to have received guideline-based care (RR = 2.0 and 1.1, respectively, p<0.05). For the aggregate of all cancers, the under-treatment rate significantly declined (p = 0.008) from 4% to 0% after the introduction of case rate payments, while the over-treatment rate remained steady at 9%, with no significant change (p = 0.20). These findings suggest that the introduction of case rate payments did not adversely affect the rate of guideline-based care at the provider examined. Additional research is needed to isolate the effect of the payment model and assess implications in other populations.

Methodology Series Module 2: Case-control Studies.

PubMed

Setia, Maninder Singh

2016-01-01

Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same 'study base' as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive - particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases - selection bias and recall bias.

Methodology Series Module 2: Case-control Studies

PubMed Central

Setia, Maninder Singh

2016-01-01

Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same ‘study base’ as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive – particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases – selection bias and recall bias. PMID:27057012

CASE STUDY CRITIQUE; UPPER CLINCH CASE STUDY

EPA Science Inventory

Case study critique: Upper Clinch case study (from Research on Methods for Integrating Ecological Economics and Ecological Risk Assessment: A Trade-off Weighted Index Approach to Integrating Economics and Ecological Risk Assessment). This critique answers the questions: 1) does ...

Assessment of Developing Intensity Duration Frequency Curves using Satellite Observations (Case Study)

NASA Astrophysics Data System (ADS)

Ombadi, Mohammed; Nguyen, Phu; Sorooshian, Soroosh

2017-12-01

Intensity Duration Frequency (IDF) curves are essential for the resilient design of infrastructures. Since their earlier development, IDF relationships have been derived using precipitation records from rainfall gauge stations. However, with the recent advancement in satellite observation of precipitation which provides near global coverage and high spatiotemporal resolution, it is worthy of attention to investigate the validity of utilizing the relatively short record length of satellite rainfall to generate robust IDF relationships. These satellite-based IDF can address the paucity of such information in the developing countries. Few studies have used satellite precipitation data in IDF development but mainly focused on merging satellite and gauge precipitation. In this study, however, IDF have been derived solely from satellite observations using PERSIANN-CDR (Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record). The unique PERSIANN-CDR attributes of high spatial resolution (0.25°×0.25°), daily temporal resolution and a record dating back to 1983 allow for the investigation at fine resolution. The results are compared over most of the contiguous United States against NOAA Atlas 14. The impact of using different methods of sampling, distribution estimators and regionalization in the resulting relationships is investigated. Main challenges to estimate robust and accurate IDF from satellite observations are also highlighted.

Six Case-Studies of Performance Assessment.

ERIC Educational Resources Information Center

Mitchell, Ruth; Stempel, Amy

Six cases are studied to give some idea of the range of performance assessments in use in the United States. Contrast and comparison are made possible through the study of the following: (1) the South Brunswick (New Jersey) Public Schools Observational Portfolio for kindergarten through grade 12; (2) the Arizona Student Assessment Program (not yet…

Urea cycle disorders in Spain: an observational, cross-sectional and multicentric study of 104 cases.

PubMed

Martín-Hernández, Elena; Aldámiz-Echevarría, Luis; Castejón-Ponce, Esperanza; Pedrón-Giner, Consuelo; Couce, María Luz; Serrano-Nieto, Juliana; Pintos-Morell, Guillem; Bélanger-Quintana, Amaya; Martínez-Pardo, Mercedes; García-Silva, María Teresa; Quijada-Fraile, Pilar; Vitoria-Miñana, Isidro; Dalmau, Jaime; Lama-More, Rosa A; Bueno-Delgado, María Amor; Del Toro-Riera, Mirella; García-Jiménez, Inmaculada; Sierra-Córcoles, Concepción; Ruiz-Pons, Mónica; Peña-Quintana, Luis J; Vives-Piñera, Inmaculada; Moráis, Ana; Balmaseda-Serrano, Elena; Meavilla, Silvia; Sanjurjo-Crespo, Pablo; Pérez-Cerdá, Celia

2014-11-30

Advances in the diagnosis and treatment of urea cycle disorders (UCDs) have led to a higher survival rate. The purpose of this study is to describe the characteristics of patients with urea cycle disorders in Spain. Observational, cross-sectional and multicenter study. Clinical, biochemical and genetic data were collected from patients with UCDs, treated in the metabolic diseases centers in Spain between February 2012 and February 2013, covering the entire Spanish population. Heterozygous mothers of patients with OTC deficiency were only included if they were on treatment due to being symptomatic or having biochemistry abnormalities. 104 patients from 98 families were included. Ornithine transcarbamylase deficiency was the most frequent condition (64.4%) (61.2% female) followed by type 1 citrullinemia (21.1%) and argininosuccinic aciduria (9.6%). Only 13 patients (12.5%) were diagnosed in a pre-symptomatic state. 63% of the cases presented with type intoxication encephalopathy. The median ammonia level at onset was 298 μmol/L (169-615). The genotype of 75 patients is known, with 18 new mutations having been described. During the data collection period four patients died, three of them in the early days of life. The median current age is 9.96 years (5.29-18), with 25 patients over 18 years of age. Anthropometric data, expressed as median and z-score for the Spanish population is shown. 52.5% of the cases present neurological sequelae, which have been linked to the type of disease, neonatal onset, hepatic failure at diagnosis and ammonia values at diagnosis. 93 patients are following a protein restrictive diet, 0.84 g/kg/day (0.67-1.10), 50 are receiving essential amino acid supplements, 0.25 g/kg/day (0.20-0.45), 58 arginine, 156 mg/kg/day (109-305) and 45 citrulline, 150 mg/kg/day (105-199). 65 patients are being treated with drugs: 4 with sodium benzoate, 50 with sodium phenylbutyrate, 10 with both drugs and 1 with carglumic acid. Studies like this make it

Lateral eddy diffusivity estimates from simulated and observed drifter trajectories: a case study for the Agulhas Current system

NASA Astrophysics Data System (ADS)

Rühs, Siren; Zhurbas, Victor; Durgadoo, Jonathan V.; Biastoch, Arne

2017-04-01

The Lagrangian description of fluid motion by sets of individual particle trajectories is extensively used to characterize connectivity between distinct oceanic locations. One important factor influencing the connectivity is the average rate of particle dispersal, generally quantified as Lagrangian diffusivity. In addition to Lagrangian observing programs, Lagrangian analyses are performed by advecting particles with the simulated flow field of ocean general circulation models (OGCMs). However, depending on the spatio-temporal model resolution, not all scale-dependent processes are explicitly resolved in the simulated velocity fields. Consequently, the dispersal of advective Lagrangian trajectories has been assumed not to be sufficiently diffusive compared to observed particle spreading. In this study we present a detailed analysis of the spatially variable lateral eddy diffusivity characteristics of advective drifter trajectories simulated with realistically forced OGCMs and compare them with estimates based on observed drifter trajectories. The extended Agulhas Current system around South Africa, known for its intricate mesoscale dynamics, serves as a test case. We show that a state-of-the-art eddy-resolving OGCM indeed features theoretically derived dispersion characteristics for diffusive regimes and realistically represents Lagrangian eddy diffusivity characteristics obtained from observed surface drifter trajectories. The estimates for the maximum and asymptotic lateral single-particle eddy diffusivities obtained from the observed and simulated drifter trajectories show a good agreement in their spatial pattern and magnitude. We further assess the sensitivity of the simulated lateral eddy diffusivity estimates to the temporal and lateral OGCM output resolution and examine the impact of the different eddy diffusivity characteristics on the Lagrangian connectivity between the Indian Ocean and the South Atlantic.

Case studies in medical futility.

PubMed

Mains, Douglas A; Coustasse, Alberto; Lurie, Sue G

2007-01-01

Technology has provided means to sustain life and provide care regardless of whether the treatment is appropriate and compassionate given the condition of the patient. This study presents two case histories, compiled from historical patient charts, staff notes and observations, that illustrate the variety of ethical issues involved and the role culture plays in the decision making process related to possible futile medical treatment. Ethical and cultural issues related to the cases are discussed and processes are presented that can help hospitals to avoid, or decrease the level of, medically futile care, and improve the cultural appropriateness of medical care and relationships with patients.

Noise peaks influence communication in the operating room. An observational study.

PubMed

Keller, Sandra; Tschan, Franziska; Beldi, Guido; Kurmann, Anita; Candinas, Daniel; Semmer, Norbert K

2016-12-01

Noise peaks are powerful distractors. This study focuses on the impact of noise peaks on surgical teams' communication during 109 long abdominal surgeries. We related measured noise peaks during 5-min intervals to the amount of observed communication during the same interval. Results show that noise peaks are associated with less case-relevant communication; this effect is moderated by the level of surgical experience; case-relevant communications decrease under high noise peak conditions among junior, but not among senior surgeons. However, case-irrelevant communication did not decrease under high noise level conditions, rather there was a trend to more case-irrelevant communication under high noise peaks. The results support the hypothesis that noise peaks impair communication because they draw on attentional resources rather than impairing understanding of communication. As case-relevant communication is important for surgical performance, exposure to high noise peaks in the OR should be minimised especially for less experienced surgeons. Practitioner Summary: This study investigated whether noise during surgeries influenced the communication within surgical teams. During abdominal surgeries, noise levels were measured and communication was observed. Results showed that high noise peaks reduced the frequency of patient-related communication, but did not reduce patient-irrelevant communication. Noise may negatively affect team coordination in surgeries.

The Campaign: A Case Study in Identity Construction through Performance

ERIC Educational Resources Information Center

Riddle, Matthew D.

2009-01-01

This article undertakes a detailed case study of "The Campaign", a teaching and learning innovation in media and communications that uses an online educational role-play. The case study draws on the qualitative analysis of classroom observations, online communications and semi-structured interviews, employing an interpretive approach…

Use of benzodiazepine and risk of cancer: A meta-analysis of observational studies.

PubMed

Kim, Hong-Bae; Myung, Seung-Kwon; Park, Yon Chul; Park, Byoungjin

2017-02-01

Several observational epidemiological studies have reported inconsistent results on the association between the use of benzodiazepine and the risk of cancer. We investigated the association by using a meta-analysis. We searched PubMed, EMBASE, and the bibliographies of relevant articles to locate additional publications in January 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria. Of 796 articles meeting our initial criteria, a total of 22 observational epidemiological studies with 18 case-control studies and 4 cohort studies were included in the final analysis. Benzodiazepine use was significantly associated with an increased risk of cancer (odds ratio [OR] or relative risk [RR] 1.19; 95% confidence interval 1.16-1.21) in a random-effects meta-analysis of all studies. Subgroup meta-analyses by various factors such as study design, type of case-control study, study region, and methodological quality of study showed consistent findings. Also, a significant dose-response relationship was observed between the use of benzodiazepine and the risk of cancer (p for trend <0.01). The current meta-analysis of observational epidemiological studies suggests that benzodiazepine use is associated with an increased risk of cancer. © 2016 UICC.

Direct Observations of Clouds on Brown Dwarfs: A Spitzer Study of Extreme Cases

NASA Astrophysics Data System (ADS)

Burgasser, Adam; Cruz, Kelle; Cushing, Michael; Kirkpatrick, J. Davy; Looper, Dagny; Lowrance, Patrick; Marley, Mark; Saumon, Didier

2008-03-01

Clouds play a fundamental role in the emergent spectral energy distributions and observed variability of very low mass stars and brown dwarfs, yet hey have only been studied indirectly thus far. Recent indications of a broad silicate grain absorption feature in the 8-11 micron spectra of mid-type L dwarfs, and evidence that the strength of this absorption varies according to broad-band near-infrared color, may finally allow the first direct studies of clouds and condensate grain properties in brown dwarf atmospheres. We propose to observe a sample of 18 ``extreme'' L dwarfs - objects with unusually blue and red near-infrared colors - with IRAC and IRS to study the 8-11 micron feature in detail (including grain size distributions and bulk compositions), and to constrain advanced condensate cloud atmosphere models currently in development. Our program provides a unique examination of the general processes of cloud formation by focusing on the relatively warm photospheres of late-type brown dwarfs.

Steroidal contraceptives and bone fractures in women: evidence from observational studies.

PubMed

Lopez, Laureen M; Chen, Mario; Mullins Long, Sarah; Curtis, Kathryn M; Helmerhorst, Frans M

2015-07-21

Age-related decline in bone mass increases the risk of skeletal fractures, especially those of the hip, spine, and wrist. Steroidal contraceptives have been associated with changes in bone mineral density in women. Whether such changes affect the risk of fractures later in life is unclear. Hormonal contraceptives are among the most effective and most widely-used contraceptives. Concern about fractures may limit the use of these effective contraceptives. Observational studies can collect data on premenopausal contraceptive use as well as fracture incidence later in life. We systematically reviewed the evidence from observational studies of hormonal contraceptive use for contraception and the risk of fracture in women. Through June 2015, we searched for observational studies. The databases included PubMed, POPLINE, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS, EMBASE, CINAHL, and Web of Science. We also searched for recent clinical trials through ClinicalTrials.gov and the ICTRP. For other studies, we examined reference lists of relevant articles and wrote to investigators for additional reports. We included cohort and case-control studies of hormonal contraceptive use. Interventions included comparisons of a hormonal contraceptive with a non-hormonal contraceptive, no contraceptive, or another hormonal contraceptive. The primary outcome was the risk of fracture. Two authors independently extracted the data. One author entered the data into RevMan, and a second author verified accuracy. We examined the quality of evidence using the Newcastle-Ottawa Quality Assessment Scale (NOS), developed for case-control and cohort studies. Sensitivity analysis included studies of moderate or high quality based on our assessment with the NOS.Given the need to control for confounding factors in observational studies, we used adjusted estimates from the models as reported by the authors. Where we did not have adjusted analyses, we calculated the odds ratio (OR

Leading and leadership: reflections on a case study.

PubMed

Joyce, Pauline

2010-05-01

The aim of this case study was to explore if observing leaders in the context of their day-to-day work can provide an insight into how they lead in particular circumstances. The study was carried out in a small organization which was set up 5 years ago. A case study methodology was used. Data were collected by field notes of non-participant and participant observations. Follow-up interviews were transcribed and analysed to contextualize the observations. A reflective diary was used by the researcher to add to the richness of the data. The data demonstrates how the leader responded in key circumstances during scheduled meetings with staff, interactions in the office and during coffee time. These responses are linked to literature on leadership in the areas of power, personal development, coaching and delegation. The findings suggest that observing a leader in the context of their day-to-day work can provide evidence to validate what leaders do in particular circumstances. The implications of the findings for nursing management are the opportunities to use observation as a tool to understand what managers/leaders do, how they manage or lead and why others respond as they do, and with what outcomes.

[Monkeypox: second human case observed in Ivory Coast (rural health sector of Daloa].

PubMed

Merouze, F; Lesoin, J J

1983-01-01

A second case of human monkeypox (world fifty-forth case) has been observed in Ivory Coast (rural health sector of Daloa). A three years old girl presented a major pox-like eruption which evolved to recovery. The authors describe the eruption, the evolution of the sickness, and the scars observed at the fourth month after recovery. It has not been possible to prove neither animal-human nor interhuman contagion.

The reporting of observational research studies in dermatology journals: a literature-based study.

PubMed

Langan, Sinéad; Schmitt, Jochen; Coenraads, Pieter-Jan; Svensson, Ake; von Elm, Erik; Williams, Hywel

2010-05-01

To assess the quality of reporting in observational studies in dermatology. Five dermatology journals-the Archives of Dermatology, the British Journal of Dermatology, the Journal of the American Academy of Dermatology, the Journal of Investigative Dermatology, and Acta Dermato-Venereologica. Cohort, case-control, and cross-sectional studies published as original articles during the period January 2005 through December 2007. Studies were identified with a literature search of PubMed combining the journal title and the term epidemiological studies (free text) and by hand searching all of the issues of each journal to identify relevant articles. All articles were extracted by 2 reviewers independently using standardized checklists based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations. The number and proportion of reported STROBE items were analyzed for each article. The proportion of studies with good reporting for each item was also assessed. A total of 138 articles were included and analyzed. Reporting quality was very mixed. Key areas that were infrequently reported included sample size calculations (n = 10 [7%]), missing data (n = 8 [6%]), losses to follow-up (n = 17 [12%]), and statistical methods (n = 19 [14%]). Only 13 studies (9%) explained the role of funders in the research. The quality of reporting was similar across study designs for "critical" questions with the exception of reporting of participant details, which was better reported in cohort studies (96%) compared with cross-sectional (80%) and case-control (70%) studies. It is difficult to judge the quality of dermatological research unless it is reported well. This study has identified a clear need to improve the quality of reporting of observational studies in dermatology. We recommend that dermatology journals adopt the STROBE criteria.

Basic concepts and development of an all-purpose computer interface for ROC/FROC observer study.

PubMed

Shiraishi, Junji; Fukuoka, Daisuke; Hara, Takeshi; Abe, Hiroyuki

2013-01-01

In this study, we initially investigated various aspects of requirements for a computer interface employed in receiver operating characteristic (ROC) and free-response ROC (FROC) observer studies which involve digital images and ratings obtained by observers (radiologists). Secondly, by taking into account these aspects, an all-purpose computer interface utilized for these observer performance studies was developed. Basically, the observer studies can be classified into three paradigms, such as one rating for one case without an identification of a signal location, one rating for one case with an identification of a signal location, and multiple ratings for one case with identification of signal locations. For these paradigms, display modes on the computer interface can be used for single/multiple views of a static image, continuous viewing with cascade images (i.e., CT, MRI), and dynamic viewing of movies (i.e., DSA, ultrasound). Various functions on these display modes, which include windowing (contrast/level), magnifications, and annotations, are needed to be selected by an experimenter corresponding to the purpose of the research. In addition, the rules of judgment for distinguishing between true positives and false positives are an important factor for estimating diagnostic accuracy in an observer study. We developed a computer interface which runs on a Windows operating system by taking into account all aspects required for various observer studies. This computer interface requires experimenters to have sufficient knowledge about ROC/FROC observer studies, but allows its use for any purpose of the observer studies. This computer interface will be distributed publicly in the near future.

Reflection of a therapeutic touch experience: case study 2.

PubMed

Green, C A

1998-02-01

The purpose of this case study was to explore the experience of both giving and receiving Therapeutic Touch. A subjective account of the Therapeutic Touch experience is given in an attempt to throw light on its unique creative and therapeutic qualities. In most instances it was shown that the experience of both giving and receiving Therapeutic Touch was a parallel experience. This case study explores the effects of Therapeutic Touch on a client experiencing pain and associated anxiety. Whilst a response to treatment was observed, the need for further case studies and research studies in this area was identified.

Clinical Case Studies in Psychoanalytic and Psychodynamic Treatment

PubMed Central

Willemsen, Jochem; Della Rosa, Elena; Kegerreis, Sue

2017-01-01

This manuscript provides a review of the clinical case study within the field of psychoanalytic and psychodynamic treatment. The method has been contested for methodological reasons and because it would contribute to theoretical pluralism in the field. We summarize how the case study method is being applied in different schools of psychoanalysis, and we clarify the unique strengths of this method and areas for improvement. Finally, based on the literature and on our own experience with case study research, we come to formulate nine guidelines for future case study authors: (1) basic information to include, (2) clarification of the motivation to select a particular patient, (3) information about informed consent and disguise, (4) patient background and context of referral or self-referral, (5) patient's narrative, therapist's observations and interpretations, (6) interpretative heuristics, (7) reflexivity and counter-transference, (8) leaving room for interpretation, and (9) answering the research question, and comparison with other cases. PMID:28210235

Alcohol Intake and Risk of Thyroid Cancer: A Meta-Analysis of Observational Studies.

PubMed

Hong, Seung-Hee; Myung, Seung-Kwon; Kim, Hyeon Suk

2017-04-01

The purpose of this study was to assess whether alcohol intake is associated with the risk of thyroid cancer by a meta-analysis of observational studies. We searched PubMed and EMBASE in June of 2015 to locate eligible studies. We included observational studies such as cross-sectional studies, case-control studies, and cohort studies reporting odd ratios (ORs) or relative risk (RRs) with 95% confidence intervals (CIs). We included 33 observational studies with two cross-sectional studies, 20 case-controls studies, and 11 cohort studies, which involved a total of 7,725 thyroid cancer patients and 3,113,679 participants without thyroid cancer in the final analysis. In the fixed-effect model meta-analysis of all 33 studies, we found that alcohol intake was consistently associated with a decreased risk of thyroid cancer (OR or RR, 0.74; 95% CI, 0.67 to 0.83; I 2 =38.6%). In the subgroup meta-analysis by type of study, alcohol intake also decreased the risk of thyroid cancer in both case-control studies (OR, 0.77; 95% CI, 0.65 to 0.92; I 2 =29.5%; n=20) and cohort studies (RR, 0.70; 95% CI, 0.60 to 0.82; I 2 =0%; n=11). Moreover, subgroup meta-analyses by type of thyroid cancer, gender, amount of alcohol consumed, and methodological quality of study showed that alcohol intake was significantly associated with a decreased risk of thyroid cancer. The current meta-analysis of observational studies found that, unlike most of other types of cancer, alcohol intake decreased the risk of thyroid cancer.

Alcohol Intake and Risk of Thyroid Cancer: A Meta-Analysis of Observational Studies

PubMed Central

Hong, Seung-Hee; Myung, Seung-Kwon; Kim, Hyeon Suk

2017-01-01

Purpose The purpose of this study was to assess whether alcohol intake is associated with the risk of thyroid cancer by a meta-analysis of observational studies. Materials and Methods We searched PubMed and EMBASE in June of 2015 to locate eligible studies. We included observational studies such as cross-sectional studies, case-control studies, and cohort studies reporting odd ratios (ORs) or relative risk (RRs) with 95% confidence intervals (CIs). Results We included 33 observational studies with two cross-sectional studies, 20 case-controls studies, and 11 cohort studies, which involved a total of 7,725 thyroid cancer patients and 3,113,679 participants without thyroid cancer in the final analysis. In the fixed-effect model meta-analysis of all 33 studies, we found that alcohol intake was consistently associated with a decreased risk of thyroid cancer (OR or RR, 0.74; 95% CI, 0.67 to 0.83; I2=38.6%). In the subgroup meta-analysis by type of study, alcohol intake also decreased the risk of thyroid cancer in both case-control studies (OR, 0.77; 95% CI, 0.65 to 0.92; I2=29.5%; n=20) and cohort studies (RR, 0.70; 95% CI, 0.60 to 0.82; I2=0%; n=11). Moreover, subgroup meta-analyses by type of thyroid cancer, gender, amount of alcohol consumed, and methodological quality of study showed that alcohol intake was significantly associated with a decreased risk of thyroid cancer. Conclusion The current meta-analysis of observational studies found that, unlike most of other types of cancer, alcohol intake decreased the risk of thyroid cancer. PMID:27456949

Neuropathology of supercentenarians - four autopsy case studies.

PubMed

Takao, Masaki; Hirose, Nobuyoshi; Arai, Yasumichi; Mihara, Ban; Mimura, Masaru

2016-09-02

Supercentenarians (aged 110 years old or more) are extremely rare in the world population (the number of living supercentenarians is estimated as 47 in the world), and details about their neuropathological information are limited. Based on previous studies, centenarians (aged 100-109 years old) exhibit several types of neuropathological changes, such as Alzheimer's disease and Lewy body disease pathology, primary age-related tauopathy, TDP-43 pathology, and hippocampal sclerosis. In the present study, we provide results from neuropathological analyses of four supercentenarian autopsy cases using conventional and immunohistochemical analysis for neurodegenerative disorders. In particular, we focused on the pathology of Alzheimer's disease and Lewy body disease, as well as the status of hippocampal sclerosis, TDP-43 pathology, aging-related tau astrogliopathy, and cerebrovascular diseases. Three cases were characterized as an "intermediate" level of Alzheimer's disease changes (NIA-AA guideline) and one was characterized as primary age-related tauopathy. TDP-43 deposits were present in the hippocampus in two cases. Neither Lewy body pathology nor hippocampal sclerosis was observed. Aging-related tau astrogliopathy was consistently observed, particularly in the basal forebrain. Small vessel diseases were also present, but they were relatively mild for cerebral amyloid-beta angiopathy and arteriolosclerosis. Although our study involved a small number of cases, the results provide a better understanding about human longevity. Neuropathological alterations associated with aging were mild to moderate in the supercentenarian brain, suggesting that these individuals might have some neuroprotective factors against aging. Future prospective studies and extensive molecular analyses are needed to determine the mechanisms of human longevity.

An Observational Case Study of Near-peer Teaching in Medical and Pharmacy Experiential Training.

PubMed

Sharif-Chan, Bayan; Tankala, Dipti; Leong, Christine; Austin, Zubin; Battistella, Marisa

2016-09-25

Objective. To compare peer teaching in a medical and a pharmacy clinical teaching unit and to provide suggestions for future research in pharmacy near-peer teaching. Methods. This exploratory observational study used principles of ethnographic methodology for data collection and analysis. Observations were collected in a large downtown teaching hospital. An average of 4-6 hours per day were spent observing a team of medical trainees from the Faculty (School) of Medicine in the general internal medicine (unit for two weeks, followed by a team of pharmacy trainees in an ambulatory hemodialysis (HD) unit for two weeks. Data was collected through field notes and informal interviews that were audiotaped and subsequently transcribed. Data was interpreted by the observer and reviewed weekly by two impartial pharmacists. Results. Five major themes emerged: (1) influence of peer teaching hierarchy; (2) educational distance between peer learners and teachers; (3) effect of the clinical teaching unit size on peer learning; (4) trainees' perception of their teaching role in the clinical teaching unit; and (5) influence of daily schedule and workload on peer teaching. As opposed to pharmacy, a hierarchy and pyramidal structure of peer teaching was observed in medical experiential training. There appeared to be no effect of educational distance on near peer teaching; however, perception of teaching role and influence of daily schedule affected near-peer teaching. Conclusion. Through initial comparisons of medical and pharmacy clinical teaching units, this study provides a reflection of elements that may be necessary to successfully implement near-peer teaching in pharmacy experiential training. Future studies in this area should assess learning outcomes and participant satisfaction, preceptor workload, and impact on patient care.

An Observational Case Study of Near-peer Teaching in Medical and Pharmacy Experiential Training

PubMed Central

Sharif-Chan, Bayan; Tankala, Dipti; Leong, Christine; Austin, Zubin

2016-01-01

Objective. To compare peer teaching in a medical and a pharmacy clinical teaching unit and to provide suggestions for future research in pharmacy near-peer teaching. Methods. This exploratory observational study used principles of ethnographic methodology for data collection and analysis. Observations were collected in a large downtown teaching hospital. An average of 4-6 hours per day were spent observing a team of medical trainees from the Faculty (School) of Medicine in the general internal medicine (unit for two weeks, followed by a team of pharmacy trainees in an ambulatory hemodialysis (HD) unit for two weeks. Data was collected through field notes and informal interviews that were audiotaped and subsequently transcribed. Data was interpreted by the observer and reviewed weekly by two impartial pharmacists. Results. Five major themes emerged: (1) influence of peer teaching hierarchy; (2) educational distance between peer learners and teachers; (3) effect of the clinical teaching unit size on peer learning; (4) trainees’ perception of their teaching role in the clinical teaching unit; and (5) influence of daily schedule and workload on peer teaching. As opposed to pharmacy, a hierarchy and pyramidal structure of peer teaching was observed in medical experiential training. There appeared to be no effect of educational distance on near peer teaching; however, perception of teaching role and influence of daily schedule affected near-peer teaching. Conclusion. Through initial comparisons of medical and pharmacy clinical teaching units, this study provides a reflection of elements that may be necessary to successfully implement near-peer teaching in pharmacy experiential training. Future studies in this area should assess learning outcomes and participant satisfaction, preceptor workload, and impact on patient care. PMID:27756922

Case-based Learning in Microbiology: Observations from a North West Indian Medical College.

PubMed

Singhal, Anita

2017-12-01

Microbiology is usually taught by conventional lectures, and its retention and application is observed to be poor among medical graduates/practitioners. Introduction of case-based learning (CBL) in microbiology for second-year professional MBBS students. Students were divided into two groups of fifty each. Four clinical cases were used for CBL. One group had two CBL sessions whereas the other had didactic lectures (DLs) and then the groups were crossed over. Case scenario handouts were given to students a week before the session, and smaller groups were formed for discussions and presentations in CBL sessions. Posttest, in multiple choice questions format, was conducted in two phases: First, immediately after the completion of the four CBL and DL sessions, and second, 6 weeks after the first posttest. Student and faculty feedback was taken about CBL sessions. Hundred MBBS students of the fourth semester voluntarily participated in the CBL study. The CBL scores were significantly higher than DL session scores ( P = 0.015). This difference was more marked in scoring done after 6 weeks of session completion ( P < 0.001). Student reported satisfaction in being taught by CBL method in 5-point Likert scale feedback form. Faculty feedback was positive for CBL. CBL helped in retention of knowledge and its application better than DL in our observation. More sessions on commonly encountered case scenarios will be useful for students in recalling basic science knowledge in their later years as practitioners.

Birth Weight and Acute Childhood Leukemia: A Meta-analysis of Observational Studies

DTIC Science & Technology

2005-03-22

22 MAR 2005 2. REPORT TYPE 3. DATES COVERED - 4. TITLE AND SUBTITLE Birth Weight and Acute Childhood Leukemia: A Meta - analysis of Observational...and to quantify the strength of the relationships. We conducted a meta - analysis of nine case-control studies (published between 1991 and 2004...Based on a meta - analysis of only three case-control studies (published between 1997 and 2004) involving over 700 children with AML and over 1,900

A Prospective Observation Study of Medical Toxicology Consultation in a U.S. Combat Theater.

PubMed

Maddry, Joseph K; Ng, Patrick C; Sessions, Daniel; Bebarta, Vikhyat S

2016-11-01

Since 2001, U.S. military personnel and active duty, uniformed physicians providing medical support have been deployed to Afghanistan. Medical toxicologists are among the physicians deployed. There is a paucity of information present in the literature that has documented cases treated by toxicologists in theater. This prospective observational study describes 15 male patients treated in theater by a military medical toxicologist. We performed a prospective observational study in which a medical toxicologist consulted and reported on deployed toxicology cases occurring during a 5-month deployment to Bagram, Afghanistan. Fifteen toxicology cases were collected during the 5-month period. The patients included three Afghan civilians, three U.S. civilians, and nine U.S. military personnel. Eight cases were attempts at recreational euphoria, two were self-harm attempts, two were from performance-enhancing supplements, two were accidental occupational exposures and one was alcohol withdrawal. Methanol was the most common exposure followed by dextromethorphan, supplements, opiates, and chlorine gas. In our study, we found that toxic alcohols and nonprescription medications were the most common exposures. In addition, this is the first study to describe bedside toxicology consults for U.S. combat forces in theater and the use of an observation unit for critically ill patients. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Relationship between the Prediction Accuracy of Tsunami Inundation and Relative Distribution of Tsunami Source and Observation Arrays: A Case Study in Tokyo Bay

NASA Astrophysics Data System (ADS)

Takagawa, T.

2017-12-01

A rapid and precise tsunami forecast based on offshore monitoring is getting attention to reduce human losses due to devastating tsunami inundation. We developed a forecast method based on the combination of hierarchical Bayesian inversion with pre-computed database and rapid post-computing of tsunami inundation. The method was applied to Tokyo bay to evaluate the efficiency of observation arrays against three tsunamigenic earthquakes. One is a scenario earthquake at Nankai trough and the other two are historic ones of Genroku in 1703 and Enpo in 1677. In general, rich observation array near the tsunami source has an advantage in both accuracy and rapidness of tsunami forecast. To examine the effect of observation time length we used four types of data with the lengths of 5, 10, 20 and 45 minutes after the earthquake occurrences. Prediction accuracy of tsunami inundation was evaluated by the simulated tsunami inundation areas around Tokyo bay due to target earthquakes. The shortest time length of accurate prediction varied with target earthquakes. Here, accurate prediction means the simulated values fall within the 95% credible intervals of prediction. In Enpo earthquake case, 5-minutes observation is enough for accurate prediction for Tokyo bay, but 10-minutes and 45-minutes are needed in the case of Nankai trough and Genroku, respectively. The difference of the shortest time length for accurate prediction shows the strong relationship with the relative distance from the tsunami source and observation arrays. In the Enpo case, offshore tsunami observation points are densely distributed even in the source region. So, accurate prediction can be rapidly achieved within 5 minutes. This precise prediction is useful for early warnings. Even in the worst case of Genroku, where less observation points are available near the source, accurate prediction can be obtained within 45 minutes. This information can be useful to figure out the outline of the hazard in an early

Use of acetaminophen and risk of endometrial cancer: evidence from observational studies.

PubMed

Ding, Yuan-Yuan; Yao, Peng; Verma, Surya; Han, Zhen-Kai; Hong, Tao; Zhu, Yong-Qiang; Li, Hong-Xi

2017-05-23

Previous meta-analyses suggested that aspirin was associated with reduced risk of endometrial cancer. However, there has been no study comprehensively summarize the evidence of acetaminophen use and risk of endometrial cancer from observational studies. We systematically searched electronic databases (PubMed , EMBASE, Web of Science, and Cochrane Library) for relevant cohort or case-control studies up to February 28, 2017. Two independent authors performed the eligibility evaluation and data extraction. All differences were resolved by discussion. A random-effects model was applied to estimate summary relative risks (RRs) with 95% CIs. All statistical tests were two-sided. Seven observational studies including four prospective cohort studies and three case-control studies with 3874 endometrial cancer cases were included for final analysis. Compared with never use acetaminophen, ever use this drug was not associated with risk of endometrial cancer (summarized RR = 1.02; 95% CI: 0.93-1.13, I2 = 0%). Similar null association was also observed when compared the highest category of frequency/duration with never use acetaminophen (summarized RR = 0.88; 95% CI: 0.70-1.11, I2 = 15.2%). Additionally, the finding was robust in the subgroup analyses stratified by study characteristics and adjustment for potential confounders and risk factors. There was no evidence of publication bias by a visual inspection of a funnel plot and formal statistical tests. In summary, the present meta-analysis reveals no association between acetaminophen use and risk of endometrial cancer. More large scale prospective cohort studies are warranted to confirm our findings and carry out the dose-response analysis of aforementioned association.

A Naturalistic Observational Study of Informal Segregation: Seating Patterns in Lectures

ERIC Educational Resources Information Center

Koen, Jennifer; Durrheim, Kevin

2010-01-01

In spite of the removal of legislated racial segregation, a number of observational studies in South Africa and elsewhere have shown that "informal," nonlegislated segregation persists in spaces of everyday interaction. Most of these have been case studies of segregation at single sites. The authors seek to quantify segregation in a…

Intensive Case Management for Addiction to promote engagement with care of people with severe mental and substance use disorders: an observational study.

PubMed

Morandi, Stéphane; Silva, Benedetta; Golay, Philippe; Bonsack, Charles

2017-05-25

Co-occurring severe mental and substance use disorders are associated with physical, psychological and social complications such as homelessness and unemployment. People with severe mental and substance use disorders are difficult to engage with care. The lack of treatment worsens their health and social conditions and increases treatment costs, as emergency department visits arise. Case management has proved to be effective in promoting engagement with care of people with severe mental and substance use disorders. However, this impact seemed mainly related to the case management model. The Intensive Case Management for Addiction (ICMA) aimed to improve engagement with care of people with severe mental and substance use disorders, insufficiently engaged with standard treatment. This innovative multidisciplinary mobile team programme combined Assertive Community Treatment and Critical Time Intervention methodologies. The aim of the study was to observe the impact of ICMA upon service use, treatment adherence and quality of support networks. Participants' psychosocial and mental functioning, and substance use were also assessed throughout the intervention. The study was observational. Eligible participants were all the people entering the programme during the first year of implementation (April 2014-April 2015). Data were collected through structured questionnaires and medical charts. Assessments were conducted at baseline and at 12 months follow-up or at the end of the programme if completed earlier. McNemar-Bowker's Test, General Linear Model repeated-measures analysis of variance and non-parametric Wilcoxon Signed Rank tests were used for the analysis. A total of 30 participants took part in the study. Results showed a significant reduction in the number of participants visiting the general emergency department compared to baseline. A significantly decreased number of psychiatric emergency department visits was also registered. Moreover, at follow-up participants

Case Study Teaching

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2011-01-01

This chapter describes the history of case study teaching, types of cases, and experimental data supporting their effectiveness. It also describes a model for comparing the efficacy of the various case study methods. (Contains 1 figure.)

A mathematical model of case-ascertainment bias: Applied to case-control studies nested within a randomized screening trial.

PubMed

Jansen, Rick J; Alexander, Bruce H; Hayes, Richard B; Miller, Anthony B; Wacholder, Sholom; Church, Timothy R

2018-01-01

When some individuals are screen-detected before the beginning of the study, but otherwise would have been diagnosed symptomatically during the study, this results in different case-ascertainment probabilities among screened and unscreened participants, referred to here as lead-time-biased case-ascertainment (LTBCA). In fact, this issue can arise even in risk-factor studies nested within a randomized screening trial; even though the screening intervention is randomly allocated to trial arms, there is no randomization to potential risk-factors and uptake of screening can differ by risk-factor strata. Under the assumptions that neither screening nor the risk factor affects underlying incidence and no other forms of bias operate, we simulate and compare the underlying cumulative incidence and that observed in the study due to LTBCA. The example used will be constructed from the randomized Prostate, Lung, Colorectal, and Ovarian cancer screening trial. The derived mathematical model is applied to simulating two nested studies to evaluate the potential for screening bias in observational lung cancer studies. Because of differential screening under plausible assumptions about preclinical incidence and duration, the simulations presented here show that LTBCA due to chest x-ray screening can significantly increase the estimated risk of lung cancer due to smoking by 1% and 50%. Traditional adjustment methods cannot account for this bias, as the influence screening has on observational study estimates involves events outside of the study observation window (enrollment and follow-up) that change eligibility for potential participants, thus biasing case ascertainment.

Vocal Fold Bowing in Elderly Male Monozygotic Twins: A Case Study

PubMed Central

Tanner, Kristine; Sauder, Cara; Thibeault, Susan L.; Dromey, Christopher; Smith, Marshall E.

2009-01-01

Objectives This study examined case histories, diagnostic features, and treatment response in two 79-year-old male monozygotic (identical) twins with vocal fold bowing, exploring both genetic and environmental factors. Study Design Case study. Methods DNA concordance was examined via cheek swab. Case histories, videostroboscopy, auditory- and visual-perceptual assessment, electromyography, acoustic measures, and Voice Handicap ratings were undertaken. Both twins underwent surgical intervention and subsequent voice therapy. Results Monozygosity was confirmed for DNA polymorphisms, with 10 of 10 concordance for STR DNA markers. For both twins, auditory and visual-perceptual assessments indicated severe bowing, hoarseness and breathiness, although Twin 1 was judged to be extremely severe. Differences in RMS amplitudes were observed for TA and LCA muscles, with smaller relative amplitudes observed for the Twin 1 versus Twin 2. No consistent voice improvement was observed following surgical intervention(s), despite improved mid-membranous vocal fold closure. Marked reductions in Voice Handicap Index total scores were observed following behavioral voice therapy, coinciding with increased mid-membranous and posterior laryngeal (interarytenoid) glottal closure. No substantive differences in acoustic measures were observed. Conclusions Vocal fold bowing was more severe for Twin 1 versus Twin 2 despite identical heritability factors. Overall voice improvement with treatment was greater for Twin 2 than Twin 1. Environmental factors might partially account for the differences observed between the twins, including variability in their responsiveness to behavioral voice therapy. Voice therapy was useful in improving mid-membranous and posterior laryngeal closure, although dysphonia remained severe in both cases. PMID:19664899

Observed wave characteristics during growth and decay: a case study

NASA Astrophysics Data System (ADS)

Prasada Rao, C. V. K.; Baba, M.

1996-10-01

Observed 1-h time series data on sea surface waves in the shelf waters off Goa, west coast of India (depth 80 m), during 17-24 March 1986, are analyzed with reference to the prevailing synoptic winds to understand wave growth and decay aspects. Wind speeds ( U10) ranged from 0 to 11.5 m s -1, whereas significant wave height ( Hs) varied between 0.6 and 2.3 m. Cross-correlation analysis between U10 and Hs revealed a time-lag of 4 h. A relationship is obtained between wave steepness ( H s/L ) and wave age ( C/U10) viz. Log 10( H s/L = -0.53 Log 10( C/U 10) - 1.385. Phillips' hypothesis of f-5 formula for equilibrium range of wave spectrum and relationship between non-dimensional energy ( E * = Eg 2/U *4) and non-dimensional peak frequency ( v * = U *f m/g ) are studied. Correlation of non-dimensional wave parameters ( E * and v *) using the present data showed a better aereement with Hasselmann et al. (1976) when comnared to Toba (1978).

Using Non-Participant Observation in Curriculum Assessment: A Case Example.

ERIC Educational Resources Information Center

Troutman, Benjamin I., Jr.

In this paper a rationale for the use of non-participant observation in curriculum development is presented. An assessment of the University of Georgia Anthropology Curriculum Project's Race, Caste, and Prejudice (RCP) provides a case example of the use of this qualitative model in educational research. The researcher's assessment of RCP focuses…

Reflective Practice through Journal Writing and Peer Observation: A Case Study

ERIC Educational Resources Information Center

Lakshmi, B. Samrajya

2014-01-01

Journal writing and Peer Observation in an educational context have become popular techniques, with several different types of applications. They have now been used quite widely in both language teaching and in teacher training. However, despite its reported advantages in both teaching and research, there are not many Peer Observation and Diary…

[The case-case-time-control study design].

PubMed

Wang, Jing; Zhuo, Lin; Zhan, Siyan

2014-12-01

Although the 'self-matched case-only studies' (such as the case-cross-over or self-controlled case-series method) can control the time-invariant confounders (measured or unmeasured) through design of the study, however, they can not control those confounders that vary with time. A bidirectional case-crossover design can be used to adjust the exposure-time trends. In the areas of pharmaco-epidemiology, illness often influence the future use of medications, making a bidirectional study design problematic. Suissa's case-time-control design combines the case-crossover and the case-control design which could adjust for exposure-trend bias, but the control group may reintroduce selection bias, if the matching does not go well. We propose a "case-case-time-control" design which is an extension of the case-time-control design. However, rather than using a sample of external controls, we choose those future cases as controls for current cases to counter the bias that arising from temporal trends caused by exposure to the target of interest. In the end of this article we will discuss the strength and limitations of this design based on an applied example.

Inter-observer and intra-observer agreement between embryologists during selection of a single Day 5 embryo for transfer: a multicenter study.

PubMed

Storr, Ashleigh; Venetis, Christos A; Cooke, Simon; Kilani, Suha; Ledger, William

2017-02-01

What is the inter-observer and intra-observer agreement between embryologists when selecting a single Day 5 embryo for transfer? The inter-observer and intra-observer agreement between embryologists when selecting a single Day 5 embryo for transfer was generally good, although not optimal, even among experienced embryologists. Previous research on the morphological assessment of early stage (two pronuclei to Day 3) embryos has shown varying levels of inter-observer and intra-observer agreement. However, single blastocyst transfer is now becoming increasingly popular and there are no published data that assess inter-observer and intra-observer agreement when selecting a single embryo for Day 5 transfer. This was a prospective study involving 10 embryologists working at five different IVF clinics within a single organization between July 2013 and November 2015. The top 10 embryologists were selected based on their yearly Quality Assurance Program scores for blastocyst grading and were asked to morphologically grade all Day 5 embryos and choose a single embryo for transfer in a survey of 100 cases using 2D images. A total of 1000 decisions were therefore assessed. For each case, Day 5 images were shown, followed by a Day 3 and Day 5 image of the same embryo. Subgroup analyses were also performed based on the following characteristics of embryologists: the level of clinical embryology experience in the laboratory; amount of research experience; number of days per week spent grading embryos. The agreement between these embryologists and the one that scored the embryos on the actual day of transfer was also evaluated. Inter-observer and intra-observer variability was assessed using the kappa coefficient to evaluate the extent of agreement. This study showed that all 10 embryologists agreed on the embryo chosen for transfer in 50 out of 100 cases. In 93 out of 100 cases, at least 6 out of the 10 embryologists agreed. The inter-observer and intra-observer agreement among

A Phenomenological Case Study: Teacher Bias Effects on Early Education Assessments

ERIC Educational Resources Information Center

Reynolds, Rebecca Jeannine

2012-01-01

This qualitative phenomenological case study explored the lived experiences of a purposive sample of 20 current and past early education teachers who have experience in assessing children through observational assessment. The purpose of this study was to determine if bias affects the documentation of observational assessment and the implementation…

Properties, propagation, and excitation of EMIC waves observed by MMS: A case study

NASA Astrophysics Data System (ADS)

Zhang, J.; Boardsen, S. A.; Coffey, V. N.; Chandler, M. O.; Saikin, A.; Mello, E. M.; Russell, C. T.; Torbert, R. B.; Fuselier, S. A.; Giles, B. L.; Gershman, D. J.

2017-12-01

Electromagnetic ion cyclotron (EMIC) waves (0.1-5 Hz) play an important role in particle dynamics in the Earth's magnetosphere. EMIC waves are preferentially excited in regions where hot anisotropic ions and cold dense plasma populations spatially overlap. While the generation region of EMIC waves is usually on or near the magnetic equatorial plane in the inner magnetosphere, EMIC waves have both equatorial and off-equator source regions on the dayside in the compressed outer magnetosphere. Using field and plasma measurements from the Magnetospheric Multiscale (MMS) mission, we perform a case study of EMIC waves and associated local plasma conditions observed on 19 October 2015. From 0315 to 0810 UT, before crossing the magnetopause into the magnetosheath, all four MMS spacecraft detected long-lasting He+-band EMIC wave emissions around local noon (MLT = 12.7 - 14.0) at high L-shells (L = 8.8 - 15.2) and low magnetic latitudes (MLAT = -21.8º - -30.3º). Energetic (> 1 keV) and anisotropic ions were present throughout this event that was in the recovery phase of a weak geomagnetic storm (min. Dst = -48 nT at 1000 UT on 18 October 2015). The testing of linear theory suggests that the EMIC waves were excited locally. Although the wave event is dominated by small normal angles, its polarization is mixed with right- and left-handedness and its propagation is bi-directional with regard to the background magnetic field. The short inter-spacecraft distances (as low as 15 km) of the MMS mission make it possible to accurately determine the k vector of the waves using the phase difference technique. Preliminary analysis finds that the k vector magnitude, phase speed, and wavelength of the 0.3-Hz wave packet at 0453:55 UT are 0.005 km-1, 372.9 km/s, and 1242.9 km, respectively. We will discuss the characteristics of the wave and particle measurements and their significance in this locale.

Study designs may influence results: the problems with questionnaire-based case-control studies on the epidemiology of glioma.

PubMed

Johansen, Christoffer; Schüz, Joachim; Andreasen, Anne-Marie Serena; Dalton, Susanne Oksbjerg

2017-03-28

Glioma is a rare brain tumour with a very poor prognosis and the search for modifiable factors is intense. We reviewed the literature concerning risk factors for glioma obtained in case-control designed epidemiological studies in order to discuss the influence of this methodology on the observed results. When reviewing the association between three exposures, medical radiation, exogenous hormone use and allergy, we critically appraised the evidence from both case-control and cohort studies. For medical radiation and hormone replacement therapy (HRT), questionnaire-based case-control studies appeared to show an inverse association, whereas nested case-control and cohort studies showed no association. For allergies, the inverse association was observed irrespective of study design. We recommend that the questionnaire-based case-control design be placed lower in the hierarchy of studies for establishing cause-and-effect for diseases such as glioma. We suggest that a state-of-the-art case-control study should, as a minimum, be accompanied by extensive validation of the exposure assessment methods and the representativeness of the study sample with regard to the exposures of interest. Otherwise, such studies cannot be regarded as 'hypothesis testing' but only 'hypothesis generating'. We consider that this holds true for all questionnaire-based case-control studies on cancer and other chronic diseases, although perhaps not to the same extent for each exposure-outcome combination.

[Case and studies].

PubMed

Schubert, András

2015-11-15

Case studies and case reports form an important and ever growing part of scientific and scholarly literature. The paper deals with the share and citation rate of these publication types on different fields of research. In general, evidence seems to support the opinion that an excessive number of such publications may negatively influence the impact factor of the journal. In the literature of scientometrics, case studies (at least the presence of the term "case study" in the titles of the papers) have a moderate share, but their citation rate is practically equal to that of other publication types.

Case Study of Ion Beams Observed By Cluster At Perigee

NASA Astrophysics Data System (ADS)

Sergeev, V.; Sauvaud, J.-A.; Perigee Beam Team

During substorms the short beams of ions in the keV-to-tens keV energy range are injected into the auroral flux tubes from the magnetotail (sometimes extending up to >100 keV energy) carrying the information on the source distance, scale-size and temporal history of plasma acceleration. We present observations with the CLUSTER crossing inward the auroral zone flux tubes at ~4Re distance near its perigee during the substorm activity on February 14, 2001. The ion beams cover the same region (poleward half) of the auroral oval where the low-energy ions are extracted from the ionosphere, and where the small-scale transient transverse Alfven waves are observed which carry predominantly the downward parallel Poynting flux into the ionosphere. The multiple beams were basically confirmed to be the transient effects, although some effects including the (spatial) velocity filter and the parallel electric fields (im- posed by quasineutrality requirement) may complicate the interpretation. The gener- ation region of ion beams is not limited to most poleward, newly-reconnected flux tubes; the beam generation region could extend across magnetic field inward by as much as >100km (if mapped to the ionosphere). Surprising variety of injection dis- tances observed nearly simultaneously (ranging between >60 Re and ~10 Re) have been inferred when using the full available energy and time resolution, with shorter injection distances be possibly associated with the flow braking process. The beam multiplicity often displays the apparent ~3 min quasiperiodicity inherent to the basic dissipation process, it was not yet explained by any substorm theory.

An alternative approach for socio-hydrology: case study research

NASA Astrophysics Data System (ADS)

Mostert, Erik

2018-01-01

Currently the most popular approach in socio hydrology is to develop coupled human-water models. This article proposes an alternative approach, qualitative case study research, involving a systematic review of (1) the human activities affecting the hydrology in the case, (2) the main human actors, and (3) the main factors influencing the actors and their activities. Moreover, this article presents a case study of the Dommel Basin in Belgium and the Netherlands, and compares this with a coupled model of the Kissimmee Basin in Florida. In both basins a pendulum swing from water resources development and control to protection and restoration can be observed. The Dommel case study moreover points to the importance of institutional and financial arrangements, community values, and broader social, economic, and technical developments. These factors are missing from the Kissimmee model. Generally, case studies can result in a more complete understanding of individual cases than coupled models, and if the cases are selected carefully and compared with previous studies, it is possible to generalize on the basis of them. Case studies also offer more levers for management and facilitate interdisciplinary cooperation. Coupled models, on the other hand, can be used to generate possible explanations of past developments and quantitative scenarios for future developments. The article concludes that, given the limited attention they currently get and their potential benefits, case studies deserve more attention in socio-hydrology.

Classroom Observation Practice in Career Schools: A Multiple Case Study

ERIC Educational Resources Information Center

Withers, Marya G.

2017-01-01

Post-secondary career school educational leaders are charged with formulating sufficient, ongoing, and effective faculty development programming to ensure the delivery of quality education in their unique trade-expert led institutions. Classroom observations, which include substantive feedback exchanges from trained personnel are well documented…

Inter-observer variability in the classification of ovarian cancer cell type using microscopy: a pilot study

NASA Astrophysics Data System (ADS)

Gavrielides, Marios A.; Ronnett, Brigitte M.; Vang, Russell; Seidman, Jeffrey D.

2015-03-01

Studies have shown that different cell types of ovarian carcinoma have different molecular profiles, exhibit different behavior, and that patients could benefit from typespecific treatment. Different cell types display different histopathology features, and different criteria are used for each cell type classification. Inter-observer variability for the task of classifying ovarian cancer cell types is an under-examined area of research. This study served as a pilot study to quantify observer variability related to the classification of ovarian cancer cell types and to extract valuable data for designing a validation study of digital pathology (DP) for this task. Three observers with expertise in gynecologic pathology reviewed 114 cases of ovarian cancer with optical microscopy, with specific guidelines for classifications into distinct cell types. For 93 cases all 3 pathologists agreed on the same cell type, for 18 cases 2 out of 3 agreed, and for 3 cases there was no agreement. Across cell types with a minimum sample size of 10 cases, agreement between all three observers was {91.1%, 80.0%, 90.0%, 78.6%, 100.0%, 61.5%} for the high grade serous carcinoma, low grade serous carcinoma, endometrioid, mucinous, clear cell, and carcinosarcoma cell types respectively. These results indicate that unanimous agreement varied over a fairly wide range. However, additional research is needed to determine the importance of these differences in comparison studies. These results will be used to aid in the design and sizing of such a study comparing optical and digital pathology. In addition, the results will help in understanding the potential role computer-aided diagnosis has in helping to improve the agreement of pathologists for this task.

Negotiating Inequality among Adult Siblings: Two Case Studies

ERIC Educational Resources Information Center

Connidis, Ingrid Arnet

2007-01-01

Qualitative instrumental case study analysis of adult siblings from 2 families explores how socioeconomic inequality among them affects their relationships to one another. Eight middle-aged siblings' observations of childhood, parental expectations, work and family history, lifestyle, and current sibling ties indicate that childhood…

Bleeding risk under selective serotonin reuptake inhibitor (SSRI) antidepressants: A meta-analysis of observational studies.

PubMed

Laporte, Silvy; Chapelle, Céline; Caillet, Pascal; Beyens, Marie-Noëlle; Bellet, Florelle; Delavenne, Xavier; Mismetti, Patrick; Bertoletti, Laurent

2017-04-01

Selective serotonin reuptake inhibitors (SSRIs) have been reported to be potentially associated with an increased risk of bleeding. A meta-analysis of observational studies was conducted to quantify this risk. Case-control and cohort studies investigating bleeding risk under SSRI therapy were retrieved by searching the Medline, Pascal, Google Scholar and Scopus databases. Case-control studies were included if they reported bleeding incidents with and without the use of SSRIs and cohort studies were included if they reported the rate of bleeds among SSRI users and non-users. The main outcome was severe bleeding, whatever the site. Only data concerning SSRI belonging to the ATC class N06AB were used. For both case-control and cohort studies, we recorded the adjusted effect estimates and their 95% confidence intervals (CI). Pooled adjusted odds ratio (OR) estimates were computed for case-control and cohort studies using an inverse-variance model. Meta-analysis of the adjusted ORs of 42 observational studies showed a significant association between SSRI use and the risk of bleeding [OR 1.41 (95% CI 1.27-1.57), random effect model, p<0.0001]. The association was found for the 31 case-control studies (1,255,073 patients), with an increased risk of 41% of bleeding [OR 1.41 (95% CI 1.25-1.60)], as well as for the 11 cohort studies including 187,956 patients [OR 1.36 (95% CI 1.12-1.64)]. Subgroup analyses showed that the association remained constant whatever the characteristics of studies. This meta-analysis shows an increased risk of bleeding of at least 36% (from 12% to 64%) based on the high-level of observational studies with SSRIs use. Copyright © 2016 Elsevier Ltd. All rights reserved.

IVHS Institutional Issues and Case Studies, Analysis and Lessons Learned, Final Report

DOT National Transportation Integrated Search

1994-04-01

This 'Analysis and Lessons Learned' report contains observations, conclusions, and recommendations based on the performance of six case studies of Intelligent Vehicle-Highway Systems (IVHS) projects. Information to support the development of the case...

Systematic Observation of an Expert Driver's Gaze Strategy—An On-Road Case Study

PubMed Central

Lappi, Otto; Rinkkala, Paavo; Pekkanen, Jami

2017-01-01

In this paper we present and qualitatively analyze an expert driver's gaze behavior in natural driving on a real road, with no specific experimental task or instruction. Previous eye tracking research on naturalistic tasks has revealed recurring patterns of gaze behavior that are surprisingly regular and repeatable. Lappi (2016) identified in the literature seven “qualitative laws of gaze behavior in the wild”: recurring patterns that tend to go together, the more so the more naturalistic the setting, all of them expected in extended sequences of fully naturalistic behavior. However, no study to date has observed all in a single experiment. Here, we wanted to do just that: present observations supporting all the “laws” in a single behavioral sequence by a single subject. We discuss the laws in terms of unresolved issues in driver modeling and open challenges for experimental and theoretical development. PMID:28496422

Utilisation of prehospital emergency medical services for hyperglycaemia: A community-based observational study.

PubMed

Villani, Melanie; Nanayakkara, Natalie; Ranasinha, Sanjeeva; Earnest, Arul; Smith, Karen; Soldatos, Georgia; Teede, Helena; Zoungas, Sophia

2017-01-01

This study examines prehospital Emergency Medical Service (EMS) utilisation and patterns of demand for hyperglycaemia management, including characteristics of individuals and factors related to hospital transport. A state-wide, community-based observational study of all patients requiring prehospital EMS for hyperglycaemia during a 7 year study period (Jan 2009-Dec 2015) using electronic data from the Ambulance Victoria data warehouse was conducted. Pre-specified variables related to patient demographics, comorbidities, examination findings, paramedic treatment and transport outcomes were obtained. Logistic regression was used to assess factors associated with transport to hospital. There were 11,417 cases of hyperglycaemia attended by paramedics during the study period, accounting for 0.3-0.4% of the total annual EMS caseload, and equating to 0.54 attendances per 100 people with diabetes in the state of Victoria, Australia, per year. There was a significant increase in annual utilisation, with a rate ratio of 1.62 between 2009 (2.42 cases per 10,000 population) and 2015 (3.91 cases per 10,000 population). Fifty-one percent of cases had type 2 diabetes, 37% had type 1 diabetes, 4% had diabetes with the type unspecified and 8% had no recorded history of diabetes. Ninety percent of cases were transported to hospital. Factors associated with increased odds of transport to hospital included no known history of diabetes, regional/rural locations, case time between 0600 and <1800 hours, increasing number of comorbidities and increasingly unstable vital sign observations. There is substantial utilisation of prehospital EMS for hyperglycaemia. With increased population prevalence of diabetes predicted, further research on opportunities for prevention, as well as optimal management in the prehospital environment is warranted.

Censored Hurdle Negative Binomial Regression (Case Study: Neonatorum Tetanus Case in Indonesia)

NASA Astrophysics Data System (ADS)

Yuli Rusdiana, Riza; Zain, Ismaini; Wulan Purnami, Santi

2017-06-01

Hurdle negative binomial model regression is a method that can be used for discreate dependent variable, excess zero and under- and overdispersion. It uses two parts approach. The first part estimates zero elements from dependent variable is zero hurdle model and the second part estimates not zero elements (non-negative integer) from dependent variable is called truncated negative binomial models. The discrete dependent variable in such cases is censored for some values. The type of censor that will be studied in this research is right censored. This study aims to obtain the parameter estimator hurdle negative binomial regression for right censored dependent variable. In the assessment of parameter estimation methods used Maximum Likelihood Estimator (MLE). Hurdle negative binomial model regression for right censored dependent variable is applied on the number of neonatorum tetanus cases in Indonesia. The type data is count data which contains zero values in some observations and other variety value. This study also aims to obtain the parameter estimator and test statistic censored hurdle negative binomial model. Based on the regression results, the factors that influence neonatorum tetanus case in Indonesia is the percentage of baby health care coverage and neonatal visits.

Pharmacotherapy for primary delusional jealousy, a retrospective observational study of 32 cases with Othello syndrome.

PubMed

Liu, Chen-Chung; Wang, Yen-Chin; Hwang, Tzung-Jeng

2018-03-01

To determine whether primary delusional jealousy can be treated effectively with antipsychotics or antidepressants, and whether any clinical variables are associated with response to pharmacotherapy, we carried out a retrospective case series observational study by reviewing clinical records of patients with an International Classification of Disease, 9th ed., diagnostic code of 297 (delusional disorders) who were treated at the Department of Psychiatry of a university affiliated hospital from January 2010 to December 2015. Only those records showing obvious delusional jealousy not secondary to other medical conditions, dementia, or schizophrenia were scrutinized thoroughly with respect to types of pharmacotherapy, treatment response, and other demographic and clinical variables likely to be associated with clinical outcomes. All except one of 32 patients, 16 men and 16 women, between 37 and 79 (60.9±10.6) years of age, were treated with low-dose antipsychotics. The general response was favorable as 19 (59.4%) were rated as good and 13 as inadequate responders (seven partial and six limited). Compared with antipsychotic monotherapy, concomitant therapy with antidepressants had a higher rate of good response, although statistically insignificant (75 vs. 53%, P=0.21). Younger age (P=0.01) and presentation at the index visit with their suspected unfaithful spouse were associated with a good response (P=0.036); comorbidity with delusions other than the jealous type was associated with a poor response (P=0.006). The overall outcome for delusional jealousy looks promising if the patients can accept pharmacotherapy in an outpatient setting.

Misclassification of Case-Control Studies in Neurosurgery and Proposed Solutions.

PubMed

Esene, Ignatius Ngene; Mbuagbaw, Lawrence; Dechambenoit, Gilbert; Reda, Wael; Kalangu, Kazadi K

2018-04-01

Case-control studies (CCS) and cohort studies (CS) are common research designs in neurosurgery. But the term case-control study is frequently misused in the neurosurgical literature, with many articles reported as CCS, even although their methodology does not respect the basic components of a CCS. We sought to estimate the extent of these discrepancies in neurosurgical literature, explore factors contributing to mislabeling, and shed some light on study design reporting. We identified 31 top-ranking pure neurosurgical journals and searched them for articles reported as CCS, either in the title or in the abstract. The articles were read to determine if they really were CCS according to STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Article assessment was conducted in duplicate (agreement [κ statistics] = 99.82%). Two hundred and twenty-four articles met our inclusion criteria, 133 of which (59.38%) correctly labeled the case-control design, whereas 91 (40.62%) misclassified this study design. Cohort studies (CS) were the most common design mislabeled as case-control studies in 76 articles (33.93%), 57 of which (25.45%) were retrospective CS. The mislabeling of CCS impairs the appropriate indexing, classification, and sorting of evidence. Mislabeling CS for CCS leads to a downgrading of evidence as CS represent the highest level of evidence for observational studies. Odds ratios instead of relative risk are reported for these studies, resulting in a distortion of the measurement of the effect size, compounded when these are summarized in systematic reviews and pooled in meta-analyses. Many studies reported as CCS are not true CCS. Reporting guidelines should include items that ensure that studies are labeled correctly. STROBE guidelines should be implemented in assessment of observational studies. Researchers in neurosurgery need better training in research methods and terminology. We also recommend accrued vigilance from

Recall bias in melanoma risk factors and measurement error effects: a nested case-control study within the Norwegian Women and Cancer Study.

PubMed

Parr, Christine L; Hjartåker, Anette; Laake, Petter; Lund, Eiliv; Veierød, Marit B

2009-02-01

Case-control studies of melanoma have the potential for recall bias after much public information about the relation with ultraviolet radiation. Recall bias has been investigated in few studies and only for some risk factors. A nested case-control study of recall bias was conducted in 2004 within the Norwegian Women and Cancer Study: 208 melanoma cases and 2,080 matched controls were invited. Data were analyzed for 162 cases (response, 78%) and 1,242 controls (response, 77%). Questionnaire responses to several host factors and ultraviolet exposures collected at enrollment in 1991-1997 and in 2004 were compared stratified on case-control status. Shifts in responses were observed among both cases and controls, but a shift in cases was observed only for skin color after chronic sun exposure, and a larger shift in cases was observed for nevi. Weighted kappa was lower for cases than for controls for most age intervals of sunburn, sunbathing vacations, and solarium use. Differences in odds ratio estimates of melanoma based on prospective and retrospective measurements indicate measurement error that is difficult to characterize. The authors conclude that indications of recall bias were found in this sample of Norwegian women, but that the results were inconsistent for the different exposures.

Role of observation of live cases done by Japanese experts in the acquisition of ESD skills by a western endoscopist.

PubMed

Draganov, Peter V; Chang, Myron; Coman, Roxana M; Wagh, Mihir S; An, Qi; Gotoda, Takuji

2014-04-28

To evaluate the role of observation of experts performing endoscopic submucosal dissection (ESD) in the acquisition of ESD skills. This prospective study is documenting the learning curve of one Western endoscopist. The study consisted of three periods. In the first period (pre-observation), the trainee performed ESDs in animal models in his home institution in the United States. The second period (observation) consisted of visit to Japan and observation of live ESD cases done by experts. The observation of cases occurred over a 5-wk period. During the third period (post-observation), the trainee performed ESD in animal models in a similar fashion as in the first period. Three animal models were used: live 40-50 kg Yorkshire pig, explanted pig stomach model, and explanted pig rectum model. The outcomes from the ESDs done in the animal models before and after observation of live human cases (main study intervention) were compared. Statistical analysis of the data included: Fisher's exact test to compare distributions of a categorical variable, Wilcoxon rank sum test to compare distributions of a continuous variable between the two groups (pre-observation and post-observation), and Kruskal-Wallis test to evaluate the impact of lesion location and type of model (ex-vivo vs live pig) on lesion removal time. The trainee performed 38 ESDs in animal model (29 pre-observation/9 post-observation). The removal times post-observation were significantly shorter than those pre-observation (32.7 ± 15.0 min vs 63.5 ± 9.8 min, P < 0.001). To minimize the impact of improving physician skill, the 9 lesions post-observation were compared to the last 9 lesions pre-observation and the removal times remained significantly shorter (32.7 ± 15.0 min vs 61.0 ± 7.4 min, P = 0.0011). Regression analysis showed that ESD observation significantly reduced removal time when controlling for the sequence of lesion removal (P = 0.025). Furthermore, it was also noted a trend towards decrease in

Observational studies and the difficult quest for causality: lessons from vaccine effectiveness and impact studies.

PubMed

Lipsitch, Marc; Jha, Ayan; Simonsen, Lone

2016-12-01

Although randomized placebo-controlled trials (RCT) are critical to establish efficacy of vaccines at the time of licensure, important remaining questions about vaccine effectiveness (VE)-used here to include individual-level measures and population-wide impact of vaccine programmes-can only be answered once the vaccine is in use, from observational studies. However, such studies are inherently at risk for bias. Using a causal framework and illustrating with examples, we review newer approaches to detecting and avoiding confounding and selection bias in three major classes of observational study design: cohort, case-control and ecological studies. Studies of influenza VE, especially in seniors, are an excellent demonstration of the challenges of detecting and reducing such bias, and so we use influenza VE as a running example. We take a fresh look at the time-trend studies often dismissed as 'ecological'. Such designs are the only observational study design that can measure the overall effect of a vaccination programme [indirect (herd) as well as direct effects], and are in fact already an important part of the evidence base for several vaccines currently in use. Despite the great strides towards more robust observational study designs, challenges lie ahead for evaluating best practices for achieving robust unbiased results from observational studies. This is critical for evaluation of national and global vaccine programme effectiveness. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

A model of scientific attitudes assessment by observation in physics learning based scientific approach: case study of dynamic fluid topic in high school

NASA Astrophysics Data System (ADS)

Yusliana Ekawati, Elvin

2017-01-01

This study aimed to produce a model of scientific attitude assessment in terms of the observations for physics learning based scientific approach (case study of dynamic fluid topic in high school). Development of instruments in this study adaptation of the Plomp model, the procedure includes the initial investigation, design, construction, testing, evaluation and revision. The test is done in Surakarta, so that the data obtained are analyzed using Aiken formula to determine the validity of the content of the instrument, Cronbach’s alpha to determine the reliability of the instrument, and construct validity using confirmatory factor analysis with LISREL 8.50 program. The results of this research were conceptual models, instruments and guidelines on scientific attitudes assessment by observation. The construct assessment instruments include components of curiosity, objectivity, suspended judgment, open-mindedness, honesty and perseverance. The construct validity of instruments has been qualified (rated load factor > 0.3). The reliability of the model is quite good with the Alpha value 0.899 (> 0.7). The test showed that the model fits the theoretical models are supported by empirical data, namely p-value 0.315 (≥ 0.05), RMSEA 0.027 (≤ 0.08)

Comparison of Estimates between Cohort and Case-Control Studies in Meta-Analyses of Therapeutic Interventions: A Meta-Epidemiological Study.

PubMed

Lanza, Amy; Ravaud, Philippe; Riveros, Carolina; Dechartres, Agnes

2016-01-01

Observational studies are increasingly being used for assessing therapeutic interventions. Case-control studies are generally considered to have greater risk of bias than cohort studies, but we lack evidence of differences in effect estimates between the 2 study types. We aimed to compare estimates between cohort and case-control studies in meta-analyses of observational studies of therapeutic interventions by using a meta-epidemiological study. We used a random sample of meta-analyses of therapeutic interventions published in 2013 that included both cohort and case-control studies assessing a binary outcome. For each meta-analysis, the ratio of estimates (RE) was calculated by comparing the estimate in case-control studies to that in cohort studies. Then, we used random-effects meta-analysis to estimate a combined RE across meta-analyses. An RE < 1 indicated that case-control studies yielded larger estimates than cohort studies. The final analysis included 23 meta-analyses: 138 cohort and 133 case-control studies. Treatment effect estimates did not significantly differ between case-control and cohort studies (combined RE 0.97 [95% CI 0.86-1.09]). Heterogeneity was low, with between-meta-analysis variance τ2 = 0.0049. Estimates did not differ between case-control and prospective or retrospective cohort studies (RE = 1.05 [95% CI 0.96-1.15] and RE = 0.99 [95% CI, 0.83-1.19], respectively). Sensitivity analysis of studies reporting adjusted estimates also revealed no significant difference (RE = 1.03 [95% CI 0.91-1.16]). Heterogeneity was also low for these analyses. We found no significant difference in treatment effect estimates between case-control and cohort studies assessing therapeutic interventions.

Observations of tropospheric trace gases and meteorology in rural Virginia using an unattended monitoring system: Hurricane Hugo (1989), A case study

NASA Astrophysics Data System (ADS)

Doddridge, Bruce G.; Dickerson, Russell R.; Holland, Joshua Z.; Cooper, James N.; Wardell, R. Glenn; Poulida, Olga; Watkins, James G.

1991-05-01

Tropospheric trace gases such as ozone and reactive nitrogen compounds exert a strong influence on global climate, but observations of these species are limited by the necessity of having a trained observer on site to monitor instruments. A technique using modern communications technology has been developed to transport and review data collected at a remote site. The site was equipped with a PAM II station and satellite data link so that raw, real-time data and equipment status were available for inspection readily on a workstation at the University of Maryland campus through a combination of wide and local area networks. CO, NO, NOy, O3, UV radiative flux, and meteorological parameters were measured in rural Virginia for a full year. The cleanest air observed over the year was associated with the passage of Hurricane Hugo over the mid-Atlantic region on September 22, 1989. Hourly average data for concentrations of CO, NOy, and O3 observed during this particular case study were as low as 90 ppbv, 570 pptv, and 11 ppbv, respectively. Within this period, daytime NO was highly variable, ranging between the detection limit of the instrument, ˜ 20 pptv, and 2.4 ppbv. These concentrations are well below the hourly concentration average at this site for these species during September 1989. Equivalent potential temperature, θe, in conjunction with the trace gas concentrations and geostrophic back-trajectories, illustrates how this hurricane influenced air parcel history; observed concentrations of CO and NOy increased with the time the air parcel spent over land. Observations at this site were consistent with current hurricane models based on mean soundings and aircraft flights. Hurricanes over land also appear to redistribute air vertically throughout the troposphere, creating the potential for substantial post-storm tropospheric column O3 increase.

Retrospective study of intravascular large B-cell lymphoma cases diagnosed in Quebec: A retrospective study of 29 case reports.

PubMed

Brunet, Vanessa; Marouan, Sofia; Routy, Jean-Pierre; Hashem, Mohamed Amin; Bernier, Vincent; Simard, Raynald; Petrella, Tony; Lamarre, Louis; Théorêt, Gilles; Carrier, Christian; Knecht, Hans; Fleury, Isabelle; Pavic, Michel

2017-02-01

Intravascular large B-cell lymphoma (IVL) is an extremely rare malignancy, mainly studied through European and Asian series. Due to the low incidence of this condition, our understanding of the clinical presentation as well as the management of IVL relies on a limited number of patients.We report the largest North American study to date on IVL with 29 cases from Quebec hospital diagnosed between 1990 and 2016. The aim of our study is to describe the clinical presentations, diagnostic and staging procedures, therapeutic management and clinical outcomes of IVL patients in our population and compare the disease phenotype to European and Asian series reported.In our cohort, all patients had stage IV IVL at diagnosis, with a median age of 66.7 years (range 47.2-90.8). Clinical presentation was characterized by constitutional symptoms (100%), poor ECOG-PS (100% ≥ 2), cytopenias (93% anemia), and elevated lactate dehydrogenase (97%) and C-reactive protein (96%). Our cohort presented with mainly cutaneous and neurological symptoms. However, neurological involvement (75.9%) was predominant and no "cutaneous variant" was observed; this differs from European literature, where "classical" IVL is reported with mainly cutaneous involvement. Two of our Caucasian patients presented "Asian variant" IVL; this observation is not unusual, as cases of "classical" IVL have been reported in Asians and "Asian variant" IVL has been reported in Europeans. All patients were classified according to their immunophenotypic features in 3 different subgroups (CD5 or CD5CD10, CD5CD10, CD5CD10) with no difference in outcome. Finally, 62% of our cohort received anthracycline-based chemotherapy and 53% of them achieved a complete response. After a median follow-up of 328 days, OS at 3 years was 42.7% for the entire cohort and 47.4% for the cases with in vivo diagnosis. Unlike European studies on "classical" IVL, our study showed that the French Canadian presentation of this subtype of IVL is more

Case-control Studies on the Effectiveness of Breast Cancer Screening: Insights from the UK Age Trial.

PubMed

van der Waal, Daniëlle; Broeders, Mireille J M; Verbeek, André L M; Duffy, Stephen W; Moss, Sue M

2015-07-01

Ongoing breast cancer screening programs can only be evaluated using observational study designs. Most studies have observed a reduction in breast cancer mortality, but design differences appear to have resulted in different estimates. Direct comparison of case-control and trial analyses gives more insight into this variation. Here, we performed case-control analyses within the randomized UK Age Trial. The Age Trial assessed the effect of screening on breast cancer mortality in women ages 40-49 years. In our approach, case subjects were defined as breast cancer deaths between trial entry (1991-1997) and 2004. Women were ages 39-41 years at entry. For every case subject, five control subjects were selected. All case subjects were included in analyses of screening invitation (356 case subjects, 1,780 controls), whereas analyses of attendance were restricted to women invited to screening (105 case subjects, 525 age-matched controls). Odds ratios (OR) were estimated with conditional logistic regression. We used and compared two methods to correct for self-selection bias. Screening invitation resulted in a breast cancer mortality reduction of 17% (95% confidence interval [CI]: -36%, +6%), similar to trial results. Different exposure definitions and self-selection adjustments influenced the observed breast cancer mortality reduction. Depending on the method, "ever screened" appeared to be associated with a small reduction (OR: 0.86, 95% CI: 0.40, 1.89) or no reduction (OR: 1.02, 95% CI: 0.48, 2.14) using the two methods of correction. Recent attendance resulted in an adjusted mortality reduction of 36% (95% CI: -69%, +31%) or 45% (95% CI: -71%, +5%). Observational studies, and particularly case-control studies, are an important monitoring tool for breast cancer screening programs. The focus should be on diminishing bias in observational studies and gaining a better understanding of the influence of study design on estimates of mortality reduction.

[Gayet-Wernicke's encephalopathy. A study of 13 cases observed in a refugee population hospitalized at the Conakry Teaching Hospital].

PubMed

Cissé, A F; Camara, N; Diallo, L L; Morel, Y; Koné, S; Camara, M I; Koumbassa, M L; Tafsir, D; Soumah, D; Djigué, B S; Camara, O B; Barry, M; Bangoura, S A; Kourouma, S; Da Silva, L; Cissé, A

2008-12-01

The authors report 13 cases of Gayet-Wernicke's encephalopathy observed in 13 patients of a refugee population. 11 presented the classical triad: oculomotor signs, cerebral ataxia and state of confusion and in 2 patients, only 2 symptoms were noted. The etiological factors: chronic alcoholism, malnutrition, uncontrollable vomiting, HIV and tuberculosis were identified. The outcome was evaluated on the basis of the disappearance of symptoms after treatment with 500 mg of thiamine in 7 patients, 1 death and 5 patients progressed toward Korsakoff amnesic syndrome.

Role of survivor bias in pancreatic cancer case-control studies.

PubMed

Hu, Zhen-Huan; Connett, John E; Yuan, Jian-Min; Anderson, Kristin E

2016-01-01

The purpose of this study was to evaluate the impact of survivor bias on pancreatic cancer case-control studies. The authors constructed five case-loss scenarios based on the Iowa Women's Health Study cohort to reflect how case recruitment in population-based studies varies by case survival time. Risk factors for disease incidence included smoking, body mass index (BMI), waist circumference, diabetes, and alcohol consumption. Odds ratios (ORs) were estimated by conditional logistic regression and quantitatively compared by the interactions between risk factors and 3-month survival time. Additionally, Kaplan-Meier estimates for overall survival were compared within the subset cohort of pancreatic cancer cases. BMI and waist circumference showed a significant inverse relationship with survival time. Decreasing trends in ORs for BMI and waist circumference were observed with increasing case survival time. The interaction between BMI and survival time based on a cutpoint of 3 months was significant (P < .01) as was the interaction between waist circumference and survival time (P < .01). The findings suggested that case losses could result in survivor bias causing underestimated odds ratios for both BMI and waist circumference, whereas other risk factors were not significantly affected by case losses. Copyright © 2016 Elsevier Inc. All rights reserved.

Building Capacity to Use Earth Observations in Decision Making: A Case Study of NASA's DEVELOP National Program Methods and Best Practices

NASA Astrophysics Data System (ADS)

Childs-Gleason, L. M.; Ross, K. W.; Crepps, G.; Miller, T. N.; Favors, J. E.; Rogers, L.; Allsbrook, K. N.; Bender, M. R.; Ruiz, M. L.

2015-12-01

NASA's DEVELOP National Program fosters an immersive research environment for dual capacity building. Through rapid feasibility Earth science projects, the future workforce and current decision makers are engaged in research projects to build skills and capabilities to use Earth observation in environmental management and policy making. DEVELOP conducts over 80 projects annually, successfully building skills through partnerships with over 150 organizations and providing over 350 opportunities for project participants each year. Filling a void between short-term training courses and long-term research projects, the DEVELOP model has been successful in supporting state, local, federal and international government organizations to adopt methodologies and enhance decision making processes. This presentation will highlight programmatic best practices, feedback from participants and partner organizations, and three sample case studies of successful adoption of methods in the decision making process.

An Observational Analysis of Coaching Behaviors for Career Development Event Teams: A Mixed Methods Study

ERIC Educational Resources Information Center

Ball, Anna L.; Bowling, Amanda M.; Sharpless, Justin D.

2016-01-01

School Based Agricultural Education (SBAE) teachers can use coaching behaviors, along with their agricultural content knowledge to help their Career Development Event (CDE) teams succeed. This mixed methods, collective case study observed three SBAE teachers preparing multiple CDEs throughout the CDE season. The teachers observed had a previous…

Hubble Case Studies of Transiting Giant Exoplanets

NASA Astrophysics Data System (ADS)

Wilkins, Ashlee N.; Deming, Drake; Barker, Adrian; Benneke, Björn; Delrez, Laetitia; Gillon, Michaël; Hamilton, Douglas P.; Jehin, Emmanuel; Knutson, Heather; Lewis, Nikole K.; Madhusudhan, Nikku; Mandell, Avi; McCullough, Peter R.; Wakeford, Hannah R.

2017-01-01

The study of planets around other stars has entered a science-rich era of characterization, in which detailed information about individual planets can be inferred from observations beyond mere detection, which only yields bulk properties like mass or radius. Characterization probes more revealing quantities such as chemical abundances, albedo, and temperature/pressure profiles, which allow us to address larger questions of planet formation mechanisms, planetary evolution, and, eventually, habitability and presence of biosignature gases. The primary method for characterization of close-in planets is transit spectroscopy. This dissertation talk will focus on transiting exoplanet case studies with the Hubble Space Telescope’ Wide-Field Camera-3 (WFC-3) as a tool of exoplanet characterization in a near-infrared band dominated by strong water features. I will first present a characterization the WFC-3 systematic effects that must be mitigated to extract the incredibly small (tens to 200 parts per million) signals, and then a study of four transiting giant planets (HATS-7b, HAT-p-3b, HD 149026b, and WASP-18b) in transmission, and two (WASP-18b and CoRoT-2b) in eclipse. Finally, I will discuss the role of transit timing monitoring of WASP-18b with HST and other observatories as another clue to its evolution as a close-in, massive planet. The five planets range from Neptune-class to Super-Jupiter-class in size/mass. Though these planets may be relatively rare, their observability represents a unique opportunity to probe planet formation and evolution, as well as atmospheric structures in a high-irradiation environment. These observations also yield insights into aerosols (i.e. clouds/hazes) in the atmosphere; clouds and/or hazes should significantly impact atmospheric chemistry and observational signatures, and we as a community must get a better handle on the phenomenon of aerosols in advance of the next generation of space observatories, including JWST and WFIRST

Case studies for observation planning algorithm of a Japanese spaceborne sensor: Hyperspectral Imager Suite (HISUI)

NASA Astrophysics Data System (ADS)

Ogawa, Kenta; Konno, Yukiko; Yamamoto, Satoru; Matsunaga, Tsuneo; Tachikawa, Tetsushi; Komoda, Mako; Kashimura, Osamu; Rokugawa, Shuichi

2016-10-01

Hyperspectral Imager Suite (HISUI)[1] is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be delivered to ISS in 2018. In HISUI project, observation strategy is important especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. We have developed concept of multiple algorithms approach. The concept is to use two (or more) algorithm models (Long Strip Model and Score Downfall Model) for selecting observing scenes from complex data acquisition requests with satisfactory of sensor constrains. We have tested the algorithm, and found that the performance of two models depends on remaining data acquisition requests, i.e. distribution score along with orbits. We conclude that the multiple algorithms approach will be make better collection plans for HISUI comparing with single fixed approach.

Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration

PubMed Central

Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G; Gøtzsche, Peter C; Mulrow, Cynthia D; Pocock, Stuart J; Poole, Charles; Schlesselman, James J; Egger, Matthias

2007-01-01

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research. PMID:17941715

Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration.

PubMed

Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G; Gøtzsche, Peter C; Mulrow, Cynthia D; Pocock, Stuart J; Poole, Charles; Schlesselman, James J; Egger, Matthias

2014-12-01

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prospective Observational Study on acute Appendicitis Worldwide (POSAW).

PubMed

Sartelli, Massimo; Baiocchi, Gian L; Di Saverio, Salomone; Ferrara, Francesco; Labricciosa, Francesco M; Ansaloni, Luca; Coccolini, Federico; Vijayan, Deepak; Abbas, Ashraf; Abongwa, Hariscine K; Agboola, John; Ahmed, Adamu; Akhmeteli, Lali; Akkapulu, Nezih; Akkucuk, Seckin; Altintoprak, Fatih; Andreiev, Aurelia L; Anyfantakis, Dimitrios; Atanasov, Boiko; Bala, Miklosh; Balalis, Dimitrios; Baraket, Oussama; Bellanova, Giovanni; Beltran, Marcelo; Melo, Renato Bessa; Bini, Roberto; Bouliaris, Konstantinos; Brunelli, Daniele; Castillo, Adrian; Catani, Marco; Che Jusoh, Asri; Chichom-Mefire, Alain; Cocorullo, Gianfranco; Coimbra, Raul; Colak, Elif; Costa, Silvia; Das, Koray; Delibegovic, Samir; Demetrashvili, Zaza; Di Carlo, Isidoro; Kiseleva, Nadezda; El Zalabany, Tamer; Faro, Mario; Ferreira, Margarida; Fraga, Gustavo P; Gachabayov, Mahir; Ghnnam, Wagih M; Giménez Maurel, Teresa; Gkiokas, Georgios; Gomes, Carlos A; Griffiths, Ewen; Guner, Ali; Gupta, Sanjay; Hecker, Andreas; Hirano, Elcio S; Hodonou, Adrien; Hutan, Martin; Ioannidis, Orestis; Isik, Arda; Ivakhov, Georgy; Jain, Sumita; Jokubauskas, Mantas; Karamarkovic, Aleksandar; Kauhanen, Saila; Kaushik, Robin; Kavalakat, Alfie; Kenig, Jakub; Khokha, Vladimir; Khor, Desmond; Kim, Dennis; Kim, Jae I; Kong, Victor; Lasithiotakis, Konstantinos; Leão, Pedro; Leon, Miguel; Litvin, Andrey; Lohsiriwat, Varut; López-Tomassetti Fernandez, Eudaldo; Lostoridis, Eftychios; Maciel, James; Major, Piotr; Dimova, Ana; Manatakis, Dimitrios; Marinis, Athanasio; Martinez-Perez, Aleix; Marwah, Sanjay; McFarlane, Michael; Mesina, Cristian; Pędziwiatr, Michał; Michalopoulos, Nickos; Misiakos, Evangelos; Mohamedahmed, Ali; Moldovanu, Radu; Montori, Giulia; Mysore Narayana, Raghuveer; Negoi, Ionut; Nikolopoulos, Ioannis; Novelli, Giuseppe; Novikovs, Viktors; Olaoye, Iyiade; Omari, Abdelkarim; Ordoñez, Carlos A; Ouadii, Mouaqit; Ozkan, Zeynep; Pal, Ajay; Palini, Gian M; Partecke, Lars I; Pata, Francesco; Pędziwiatr, Michał; Pereira Júnior, Gerson A; Pintar, Tadeja; Pisarska, Magdalena; Ploneda-Valencia, Cesar F; Pouggouras, Konstantinos; Prabhu, Vinod; Ramakrishnapillai, Padmakumar; Regimbeau, Jean-Marc; Reitz, Marianne; Rios-Cruz, Daniel; Saar, Sten; Sakakushev, Boris; Seretis, Charalampos; Sazhin, Alexander; Shelat, Vishal; Skrovina, Matej; Smirnov, Dmitry; Spyropoulos, Charalampos; Strzałka, Marcin; Talving, Peep; Teixeira Gonsaga, Ricardo A; Theobald, George; Tomadze, Gia; Torba, Myftar; Tranà, Cristian; Ulrych, Jan; Uzunoğlu, Mustafa Y; Vasilescu, Alin; Occhionorelli, Savino; Venara, Aurélien; Vereczkei, Andras; Vettoretto, Nereo; Vlad, Nutu; Walędziak, Maciej; Yilmaz, Tonguç U; Yuan, Kuo-Ching; Yunfeng, Cui; Zilinskas, Justas; Grelpois, Gérard; Catena, Fausto

2018-01-01

Acute appendicitis (AA) is the most common surgical disease, and appendectomy is the treatment of choice in the majority of cases. A correct diagnosis is key for decreasing the negative appendectomy rate. The management can become difficult in case of complicated appendicitis. The aim of this study is to describe the worldwide clinical and diagnostic work-up and management of AA in surgical departments. This prospective multicenter observational study was performed in 116 worldwide surgical departments from 44 countries over a 6-month period (April 1, 2016-September 30, 2016). All consecutive patients admitted to surgical departments with a clinical diagnosis of AA were included in the study. A total of 4282 patients were enrolled in the POSAW study, 1928 (45%) women and 2354 (55%) men, with a median age of 29 years. Nine hundred and seven (21.2%) patients underwent an abdominal CT scan, 1856 (43.3%) patients an US, and 285 (6.7%) patients both CT scan and US. A total of 4097 (95.7%) patients underwent surgery; 1809 (42.2%) underwent open appendectomy and 2215 (51.7%) had laparoscopic appendectomy. One hundred eighty-five (4.3%) patients were managed conservatively. Major complications occurred in 199 patients (4.6%). The overall mortality rate was 0.28%. The results of the present study confirm the clinical value of imaging techniques and prognostic scores. Appendectomy remains the most effective treatment of acute appendicitis. Mortality rate is low.

Sustaining Latina Student Organizations: An Exploratory Instrumental Case Study

ERIC Educational Resources Information Center

Castellanos, Michelle

2016-01-01

Utilizing the exploratory case study methodology, the author examines the conditions that support and limit a Latina-based student organization at a predominately White institution of higher education. Seven organizational structures were found to influence the organization's ability to advance its aims, from interviews, documents, observations,…

Inside the Black Box--An Implementation Evaluation Case Study

ERIC Educational Resources Information Center

Rector, Patricia; Bakacs, Michele; Rowe, Amy; Barbour, Bruce

2016-01-01

The case study presented in this article is an example of an implementation evaluation. The evaluation investigated significant components of the implementation of a long-term environmental educational program. Direct observation, evaluation-specific survey data, and historical data were used to determine program integrity as identified by…

[Case-non case studies: Principles, methods, bias and interpretation].

PubMed

Faillie, Jean-Luc

2017-10-31

Case-non case studies belongs to the methods assessing drug safety by analyzing the disproportionality of notifications of adverse drug reactions in pharmacovigilance databases. Used for the first time in the 1980s, the last few decades have seen a significant increase in the use of this design. The principle of the case-non case study is to compare drug exposure in cases of a studied adverse reaction with that of cases of other reported adverse reactions and called "non cases". Results are presented in the form of a reporting odds ratio (ROR), the interpretation of which makes it possible to identify drug safety signals. This article describes the principle of the case-non case study, the method of calculating the ROR and its confidence interval, the different modalities of analysis and how to interpret its results with regard to the advantages and limitations of this design. Copyright © 2017 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

VIEWDEX: an efficient and easy-to-use software for observer performance studies.

PubMed

Håkansson, Markus; Svensson, Sune; Zachrisson, Sara; Svalkvist, Angelica; Båth, Magnus; Månsson, Lars Gunnar

2010-01-01

The development of investigation techniques, image processing, workstation monitors, analysing tools etc. within the field of radiology is vast, and the need for efficient tools in the evaluation and optimisation process of image and investigation quality is important. ViewDEX (Viewer for Digital Evaluation of X-ray images) is an image viewer and task manager suitable for research and optimisation tasks in medical imaging. ViewDEX is DICOM compatible and the features of the interface (tasks, image handling and functionality) are general and flexible. The configuration of a study and output (for example, answers given) can be edited in any text editor. ViewDEX is developed in Java and can run from any disc area connected to a computer. It is free to use for non-commercial purposes and can be downloaded from http://www.vgregion.se/sas/viewdex. In the present work, an evaluation of the efficiency of ViewDEX for receiver operating characteristic (ROC) studies, free-response ROC (FROC) studies and visual grading (VG) studies was conducted. For VG studies, the total scoring rate was dependent on the number of criteria per case. A scoring rate of approximately 150 cases h(-1) can be expected for a typical VG study using single images and five anatomical criteria. For ROC and FROC studies using clinical images, the scoring rate was approximately 100 cases h(-1) using single images and approximately 25 cases h(-1) using image stacks ( approximately 50 images case(-1)). In conclusion, ViewDEX is an efficient and easy-to-use software for observer performance studies.

Pedagogical Content Knowledge: A Case Study of ESL Teacher Educator

ERIC Educational Resources Information Center

Liu, Siping

2013-01-01

This single-case study focuses on the pedagogical content knowledge (PCK) of a university faculty member teaching Second Language Acquisition to elementary teacher candidates. The research questions address the pattern and development of PCK for ESL teaching. Based on data from classroom observation, interviews and document review, the study finds…

Successful Minority Pedagogy in Mathematics: US and Japanese Case Studies

ERIC Educational Resources Information Center

Ahn, Ruth; Catbagan, Paula; Tamayo, Kristin; I, Ji Yeong; Lopez, Mario; Walker, Pamela

2015-01-01

This study examines best practices in teaching mathematics to minority students through two case studies conducted at high-minority junior high schools in the USA and Japan. Observations, interviews, and conversations with the teachers in both countries focused on the research question: how do teachers successfully teach mathematics to minority…

[The management of 126 cases of posterior cracked crown of tooth and its effective observation].

PubMed

Chen, L L

2000-06-01

To detect the treatment and effect of posterior cracked tooth. 162 posterior cracked teeth of 158 cases, including enamel fissure and dentin fissure, all there cases undergone the synthetical treatment and follow up in different period, the longest observation period was 2.5 years. The healing and improved rate of 162 cracked teeth 90.74%. Among cases of failure, we have founded 6 cases of acute pulpitis (3.7%), 3 cases of alveodental abscess (1.85%), 2 cases of chronic apical periodontitis (1.24%), 4 cases of tooth fracture (2.4%). Cracked tooth was caused by multiple factors. Early diagnosis, synthetical treatment, and follow up in different period are 3 main factors in treatment.

Case-Based Instructional Practices: A Multiple-Case Study from Torts, Marketing, and Online Instructional Design Classes

ERIC Educational Resources Information Center

Jung, Ji yoon

2017-01-01

The purpose of this study is to provide a comprehensive account on case-based instructional practices. Semester-long participant observation records in torts, marketing, and online instructional design classes, instructor interviews, course syllabi and teaching materials were used to describe the within-class complexity of the practices in terms…

An Observation Capability Semantic-Associated Approach to the Selection of Remote Sensing Satellite Sensors: A Case Study of Flood Observations in the Jinsha River Basin

PubMed Central

Hu, Chuli; Li, Jie; Lin, Xin

2018-01-01

Observation schedules depend upon the accurate understanding of a single sensor’s observation capability and the interrelated observation capability information on multiple sensors. The general ontologies for sensors and observations are abundant. However, few observation capability ontologies for satellite sensors are available, and no study has described the dynamic associations among the observation capabilities of multiple sensors used for integrated observational planning. This limitation results in a failure to realize effective sensor selection. This paper develops a sensor observation capability association (SOCA) ontology model that is resolved around the task-sensor-observation capability (TSOC) ontology pattern. The pattern is developed considering the stimulus-sensor-observation (SSO) ontology design pattern, which focuses on facilitating sensor selection for one observation task. The core aim of the SOCA ontology model is to achieve an observation capability semantic association. A prototype system called SemOCAssociation was developed, and an experiment was conducted for flood observations in the Jinsha River basin in China. The results of this experiment verified that the SOCA ontology based association method can help sensor planners intuitively and accurately make evidence-based sensor selection decisions for a given flood observation task, which facilitates efficient and effective observational planning for flood satellite sensors. PMID:29883425

An Observation Capability Semantic-Associated Approach to the Selection of Remote Sensing Satellite Sensors: A Case Study of Flood Observations in the Jinsha River Basin.

PubMed

Hu, Chuli; Li, Jie; Lin, Xin; Chen, Nengcheng; Yang, Chao

2018-05-21

Observation schedules depend upon the accurate understanding of a single sensor’s observation capability and the interrelated observation capability information on multiple sensors. The general ontologies for sensors and observations are abundant. However, few observation capability ontologies for satellite sensors are available, and no study has described the dynamic associations among the observation capabilities of multiple sensors used for integrated observational planning. This limitation results in a failure to realize effective sensor selection. This paper develops a sensor observation capability association (SOCA) ontology model that is resolved around the task-sensor-observation capability (TSOC) ontology pattern. The pattern is developed considering the stimulus-sensor-observation (SSO) ontology design pattern, which focuses on facilitating sensor selection for one observation task. The core aim of the SOCA ontology model is to achieve an observation capability semantic association. A prototype system called SemOCAssociation was developed, and an experiment was conducted for flood observations in the Jinsha River basin in China. The results of this experiment verified that the SOCA ontology based association method can help sensor planners intuitively and accurately make evidence-based sensor selection decisions for a given flood observation task, which facilitates efficient and effective observational planning for flood satellite sensors.

Strengthening the reliability and credibility of observational epidemiology studies by creating an Observational Studies Register.

PubMed

Swaen, Gerard M H; Carmichael, Neil; Doe, John

2011-05-01

To evaluate the need for the creation of a system in which observational epidemiology studies are registered; an Observational Studies Register (OSR). The current scientific process for observational epidemiology studies is described. Next, a parallel is made with the clinical trials area, where the creation of clinical trial registers has greatly restored and improved their credibility and reliability. Next, the advantages and disadvantages of an OSR are compared. The advantages of an OSR outweigh its disadvantages. The creation of an OSR, similar to the existing Clinical Trials Registers, will improve the assessment of publication bias and will provide an opportunity to compare the original study protocol with the results reported in the publication. Reliability, credibility, and transparency of observational epidemiology studies are strengthened by the creation of an OSR. We propose a structured, collaborative, and coordinated approach for observational epidemiology studies that can provide solutions for existing weaknesses and will strengthen credibility and reliability, similar to the approach currently used in clinical trials, where Clinical Trials Registers have played a key role in strengthening their scientific value. Copyright © 2011 Elsevier Inc. All rights reserved.

Marked seasonality of Cyclospora cayetanensis infections: ten-year observation of hospital cases, Honduras.

PubMed

Kaminsky, Rina Girard; Lagos, Javier; Raudales Santos, Gabriela; Urrutia, Samuel

2016-02-04

Document seasonality occurrence and epidemiologic characteristics of Cyclospora cayetanensis infections during a 10-year period from patients consulting at the University Hospital, Honduras. Retrospective non interventional hospital-based study analyzed laboratory results from the period 2002 to 2011 of fresh and Ziehl-Nielsen carbolfuchsin stained routine stool samples received for parasitologic examination. Sporadically a sample with numerous oocysts was allowed to sporulate in 2.5 % potassium dichromate confirming the presence of bi-cystic bi-zoic oocysts. A total of 35,157 fecal samples were examined during a ten-year span, of which a third (28.4 %) was stained by the Ziehl-Neelsen carbolfuchsin method diagnosing a total of 125 (1.3 %) C.cayetanensis infections. A statistically significant apparent seasonality was observed most years during May to August (range p < 0.036-0.001), with 83.3 % of 125 cases occurring in those rainy months. All C. cayetanensis cases came from urban poor neighborhoods; male/female relation was 1:1 except in 2006, when all patients were females (p = 0.05; r(2) = 22,448). Forty four point eight percent of the stool samples were diarrheic or liquid and 65.6 % infections were identified in children 10 years old or less. Enteric helminths and protozoa co-infected Cyclospora positive patients in 52 instances.: 8 % Ascaris lumbricoides, 8 % Giardia duodenalis, 23.2 % Blastocystis spp. and less frequently Entamoeba histolytica/E. dispar, Strongyloides stercoralis, and Trichuris trichiura. Results suggest a seasonal pattern for Cyclospora infections diagnosed in a clinical setting during the rainy months in Tegucigalpa and surrounding areas. Community studies should be conducted to support or dispute these observations.

Quality of care in integrated community case management services in Bugoye, Uganda: a retrospective observational study.

PubMed

Miller, James S; English, Lacey; Matte, Michael; Mbusa, Rapheal; Ntaro, Moses; Bwambale, Shem; Kenney, Jessica; Siedner, Mark J; Reyes, Raquel; Lee, Patrick T; Mulogo, Edgar; Stone, Geren S

2018-02-27

Village health workers (VHWs) in five villages in Bugoye subcounty (Kasese District, Uganda) provide integrated community case management (iCCM) services, in which VHWs evaluate and treat malaria, pneumonia, and diarrhoea in children under 5 years of age. VHWs use a "Sick Child Job Aid" that guides them through the evaluation and treatment of these illnesses. A retrospective observational study was conducted to measure the quality of iCCM care provided by 23 VHWs in 5 villages in Bugoye subcounty over a 2-year period. Patient characteristics and clinical services were summarized using existing aggregate programme data. Lot quality assurance sampling of individual patient records was used to estimate adherence to the iCCM algorithm, VHW-level quality (based on adherence to the iCCM protocol), and change over time in quality of care (using generalized estimating equations regression modelling). For each of 23 VHWs, 25 patient visits were randomly selected from a 2-year period after iCCM care initiation. In these visits, 97% (150) of patients with diarrhoea were treated with oral rehydration and zinc, 95% (216) of patients with pneumonia were treated with amoxicillin, and 94% (240) of patients with malaria were treated with artemisinin-based combination therapy or rectal artesunate. However, only 44% (44) of patients with a negative rapid test for malaria were appropriately referred to a health facility. Overall, 75% (434) of patients received all the correct evaluation and management steps. Only 9 (39%) of the 23 VHWs met the pre-determined LQAS threshold for high-quality care over the 2-year observation period. Quality of care increased significantly in the first 6 months after initiation of iCCM services (p = 0.003), and then plateaued during months 7-24. Quality of care was high for uncomplicated malaria, pneumonia and diarrhoea. Overall quality of care was lower, in part because VHWs often did not follow the guidelines to refer patients with fever who tested

Comparison of case fatality in south Asian and white patients after acute myocardial infarction: observational study.

PubMed

Wilkinson, P; Sayer, J; Laji, K; Grundy, C; Marchant, B; Kopelman, P; Timmis, A D

1996-05-25

To compare mortality in south Asian (Indian, Pakistani, and Bangladeshi) and white patients in the six months after hospital admission for acute myocardial infarction. Observational study. District general hospital in east London. 149 south Asian and 313 white patients aged < 65 years admitted to the coronary care unit with acute myocardial infarction from 1 December 1988 to 31 December 1992. All cause mortality in the first six months after myocardial infarction. The admission rate in the south Asians was estimated to be 2.04 times that in the white patients. Most aspects of treatment were similar in the two groups, except that a higher proportion of the south Asians received thrombolytic drugs (81.2% v 73.8%). After adjustment for age, sex, previous myocardial infarction, and treatment with thrombolysis or aspirin, or both, the south Asians had a poorer survival over the six months from myocardial infarction (hazard ratio 2.02 (95% confidence interval 1.14 to 3.56), P = 0.018), but a substantially higher proportion were diabetic (38% v 11%, P < 0.001), and additional adjustment for diabetes removed much of their excess risk (adjusted hazard ratio 1.26 (0.68 to 2.33), P = 0.47). South Asian patients had a higher risk of admission with myocardial infarction and a higher risk of death over the ensuing six months than the white patients. The higher case fatality among the south Asians, largely attributable to diabetes, may contribute to the increased risk of death from coronary heart disease in south Asians living in Britain.

Patient safety incidents in hospice care: observations from interdisciplinary case conferences.

PubMed

Oliver, Debra Parker; Demiris, George; Wittenberg-Lyles, Elaine; Gage, Ashley; Dewsnap-Dreisinger, Mariah L; Luetkemeyer, Jamie

2013-12-01

In the home hospice environment, issues arise every day presenting challenges to the safety, care, and quality of the dying experience. The literature pertaining to the safety challenges in this environment is limited. The study explored two research questions; 1) What types of patient safety incidents occur in the home hospice setting? 2) How many of these incidents are recognized by the hospice staff and/or the patient or caregiver as a patient safety incident? Video-recordings of hospice interdisciplinary team case conferences were reviewed and coded for patient safety incidents. Patient safety incidents were defined as any event or circumstance that could have resulted or did result in unnecessary harm to the patient or caregiver, or that could have resulted or did result in a negative impact on the quality of the dying experience for the patient. Codes for categories of patient safety incidents were based on the International Classification for Patient Safety. The setting for the study included two rural hospice programs in one Midwestern state in the United States. One hospice team had two separately functioning teams, the second hospice had three teams. 54 video-recordings were reviewed and coded. Patient safety incidents were identified that involved issues in clinical process, medications, falls, family or caregiving, procedural problems, documentation, psychosocial issues, administrative challenges and accidents. This study distinguishes categories of patient safety events that occur in home hospice care. Although the scope and definition of potential patient safety incidents in hospice is unique, the events observed in this study are similar to those observed with in other settings. This study identifies an operating definition and a potential classification for further research on patient safety incidents in hospice. Further research and consensus building of the definition of patient safety incidents and patient safety incidents in this setting is

Meningoceles, meningomyeloceles, and encephaloceles: a neuro-dermatopathologic study of 132 cases.

PubMed

Berry, A D; Patterson, J W

1991-06-01

Because there have been few comprehensive histopathologic studies of meningomyeloceles and related malformations, we undertook a systematic study of these lesions. One hundred and thirty two cases were obtained from our surgical pathology files; these included 38 meningoceles, 71 meningomyeloceles, and 23 encephaloceles. Tissue sections were stained with hematoxylin and eosin; special stains included trichrome, alcian blue, Fontana-Masson, Nissl, Holzer, and immunoperoxidase for glial fibrillary acidic protein. Epithelial changes included ulceration, atrophy, or nevoid hyperplasia of the epidermis, and loss of appendages. Mesodermal features included fibrous zones resembling dura, subarachnoid tissue or scar (99% of cases), increased numbers of blood vessels (83%), hypertrophy of arrector pili muscle (42%), lipoma formation (38%), and immature skeletal muscle fibers (5%) that rarely intermingled with neuropil-like matrix. The latter tissue was identified in 71% of cases and included neurons, astrocytes, oligodendroglia, and ependyma. Forty-eight percent of cases included peripheral nerve fibers or roots, and some fibers formed onion bulb or Pacinian corpuscle-like structures. Meningothelial cells were observed in 26% of cases and sometimes formed recognizable whorls. Choroid plexus was noted in 3 cases, one example showing an unusual dystrophic calcification that formed long parallel spicules. Pigmented dendritic cells were observed within zones of fibrous tissue in 10% of cases. These malformations involve complex arrangements of cutaneous, neuroectodermal, and mesodermal elements. Because they may be encountered by dermatopathologists, familiarity with the microscopic features of dysraphic lesions is essential.

Administrative complexities for a European observational study despite directives harmonising requirements.

PubMed

Gülmez, Sinem Ezgi; Lignot-Maleyran, Séverine; de Vries, Corinne S; Sturkenboom, Miriam; Micon, Sophie; Hamoud, Fatima; Blin, Patrick; Moore, Nicholas

2012-08-01

For pharmacoepidemiological studies in Europe, accessing data should require only authorisation by the relevant data protections committees, as expected from the 1995 Data Protection Directive (95/46/EC). Our experience from a multinational observational study across seven European countries shows that this is certainly not the case. The study was a multicentre, multinational, case-population study in European liver transplant centres in seven countries, retrospectively evaluating a 3-year period. Before data collection started, the procedures to obtain the necessary authorisations for the participating countries were defined. In France, a single opinion from a single data protection committee was enough to start the study. In Italy, Portugal, Greece and the UK, there was a national authority, but the hospitals requested the approval by their local committees/bodies irrespective of whether the authorisation of the national committee came after or before that of local ones. In Ireland, only one hospital participated, and the opinion of its ethics committee was sufficient. In the Netherlands, the opinion of the institutional review board of the local coordinating centre was necessary to obtain the opinions from the institutional review boards of the other hospitals. The information requested by the different committees and the time to obtain the approvals varied, even within the same country. This degree of complexity and disharmony, and resulting cost, was observed in a simple retrospective study. Regulators will need to be aware that these time-consuming, expensive and useless complexities must be factored in when estimating the time and cost of a study. Copyright © 2012 John Wiley & Sons, Ltd.

Whole-genome sequencing to determine Neisseria gonorrhoeae transmission: an observational study

PubMed Central

Cole, Kevin; Cole, Michelle J; Cresswell, Fiona; Dean, Gillian; Dave, Jayshree; Thomas, Daniel Rh; Foster, Kirsty; Waldram, Alison; Wilson, Daniel J; Didelot, Xavier; Grad, Yonatan H; Crook, Derrick W; Peto, Tim EA; Walker, A Sarah

2016-01-01

Background New approaches are urgently required to address increasing rates of gonorrhoea and the emergence and global spread of antibiotic-resistant Neisseria gonorrhoeae. Whole genome sequencing (WGS) can be applied to study transmission and track resistance. Methods We performed WGS on 1659 isolates from Brighton, UK, and 217 additional isolates from other UK locations. We included WGS data (n=196) from the USA. Estimated mutation rates, plus diversity observed within patients across anatomical sites and probable transmission pairs, were used to fit a coalescent model to determine the number of single nucleotide polymorphisms (SNPs) expected between sequences related by direct/indirect transmission, depending on the time between samples. Findings We detected extensive local transmission. 281/1061(26%) Brighton cases were indistinguishable (0 SNPs) to ≥1 previous case(s), and 786(74%) had evidence of a sampled direct or indirect Brighton source. There was evidence of sustained transmission of some lineages. We observed multiple related samples across geographic locations. Of 1273 infections in Brighton, 225(18%) were linked to another case from elsewhere in the UK, and 115(9%) to a case from the USA. Four lineages initially identified in Brighton could be linked to 70 USA sequences, including 61 from a lineage carrying the mosaic penA XXXIV associated with reduced cefixime susceptibility. Interpretation We present a WGS-based tool for genomic contact tracing of N. gonorrhoeae and demonstrate local, national and international transmission. WGS can be applied across geographical boundaries to investigate gonorrhoea transmission and to track antimicrobial resistance. Funding Oxford NIHR Health Protection Research Unit and Biomedical Research Centre. PMID:27427203

Brain fag: New perspectives from case observations.

PubMed

Ebigbo, Peter O; Lekwas, Elekwachi Chimezie; Chukwunenyem, Nweze Felix

2015-06-01

Brain fag was originally described as a culture-bound syndrome among West African students. The term "brain fag" literally means "brain fatigue." Available literature indicates that brain fag symptoms usually present in formal academic settings when African students are required to transit to a reliance on written literature (as opposed to more traditional oral forms of information transmission) and to adapt to westernized, individualistic systems of education that, at times, oppose the values of relatively collectivistic African societies. Based on detailed observation of two typical and two nontypical cases of brain fag, the authors suggest that the syndrome may not be solely related to tensions in the academic sphere, but may function more generally as an expression of psychological distress that results from societal pressures that exceed the coping capacity of the individual. The brain fag symptoms, including lack of concentration, sensations of internal heat in the head and body, heaviness, and multiple somatic complaints, may constitute a defensive process which helps prevent a full-fledged decompensation. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Mining Temporal Patterns to Improve Agents Behavior: Two Case Studies

NASA Astrophysics Data System (ADS)

Fournier-Viger, Philippe; Nkambou, Roger; Faghihi, Usef; Nguifo, Engelbert Mephu

We propose two mechanisms for agent learning based on the idea of mining temporal patterns from agent behavior. The first one consists of extracting temporal patterns from the perceived behavior of other agents accomplishing a task, to learn the task. The second learning mechanism consists in extracting temporal patterns from an agent's own behavior. In this case, the agent then reuses patterns that brought self-satisfaction. In both cases, no assumption is made on how the observed agents' behavior is internally generated. A case study with a real application is presented to illustrate each learning mechanism.

Vitamin C Intake and Pancreatic Cancer Risk: A Meta-Analysis of Published Case-Control and Cohort Studies.

PubMed

Hua, Yong-Fei; Wang, Gao-Qing; Jiang, Wei; Huang, Jing; Chen, Guo-Chong; Lu, Cai-De

2016-01-01

Observational studies inconsistently reported the relationship between vitamin C intake and risk of pancreatic cancer. We conducted a meta-analysis of published case-control and cohort studies to quantify the association. Potentially eligible studies were found on PubMed and EMBASE databases through May 31, 2015. A random-effects model was assigned to compute summary point estimates with corresponding 95% confidence intervals (CIs). Subgroup and meta-regression analyses were also performed to explore sources of heterogeneity. Our final analyses included 20 observational studies comprising nearly 5 thousand cases of pancreatic cancer. When comparing the highest with the lowest categories of vitamin C intake, the summary odds ratio/relative risk for case-control studies (14 studies), cohort studies (6 studies) and all studies combined was 0.58 (95% CI: 0.52-0.66), 0.93 (95% CI: 0.78-1.11) and 0.66 (95% CI: 0.58-0.75), respectively. The difference in the findings between case-control and cohort studies was statistically significant (P < .001). Possible publication bias was shown in the meta-analysis of case-control studies. There is insufficient evidence to conclude any relationship between vitamin C intake and risk of pancreatic cancer. The strong inverse association observed in case-control studies may be affected by biases (eg, recall and selection biases) that particularly affect case-control studies and/or potential publication bias. Future prospective studies of vitamin C intake and pancreatic cancer are needed.

Langerhans cell histiocytosis of skull: a retrospective study of 18 cases.

PubMed

Zhang, Xiang-Heng; Zhang, Ji; Chen, Zheng-He; Sai, Ke; Chen, Yin-Sheng; Wang, Jian; Ke, Chao; Guo, Chen-Chen; Chen, Zhong-Ping; Mou, Yong-Gao

2017-04-01

The present study presents 18 cases of Chinese patients harboring a Langerhans cell histiocytosis (LCH) of the skull. Eighteen consecutive patients were diagnosed as LCH of the skull and confirmed pathologically between March 2002 and February 2014. In the present study, the patients of LCH without skull involvement were excluded. According to disease extent at diagnosis, the 18 LCH patients with skull involvement were divided into three groups: (I) unifocal-monosystem group, including ten cases with solitary skull lesion; (II) multifocal-monosystem group, including two cases with multiple bone lesions and no extra-skeletal involvement; (III) multisystem group, including six cases with LCH lesions involving both skeletal and extra-skeletal system. In unifocal-monosystem group, excision of the skull lesion was performed in eight of ten cases, a low dosage of local radiotherapy and a purposeful observation was accept by the remaining two cases of this group after biopsy respectively. In multifocal-monosystem group, both of the two cases were received chemotherapy. In multi-system group, all the six cases were managed with systemic chemotherapy, after their diagnoses of LCH were confirmed. The mean age at the time of diagnosis was 9.4 years. There was a male predominance in this disease male/female ratio was 3.5:1. In our cases, a skull mass with or without tenderness was the most common chief complaint (13 cases, 72.2%), and frontal bone was the most frequent affected locations of skull (6 cases, 33.3%). In unifocal-monosystem group, nine of ten remained free from LCH, the remain one lesion recurred 22 months after his surgical excision. In multifocal-monosystem group, a complete response (CR) was obtained in one of them, and a stable disease (SD) of multiple osseous lesions was obtained in another one. In the multi-system group, a CR in four cases and a partial response (PR) in one case were obtained, and a progressive disease (PD) was observed in the remaining one

Clinical Research Methodology 2: Observational Clinical Research.

PubMed

Sessler, Daniel I; Imrey, Peter B

2015-10-01

Case-control and cohort studies are invaluable research tools and provide the strongest feasible research designs for addressing some questions. Case-control studies usually involve retrospective data collection. Cohort studies can involve retrospective, ambidirectional, or prospective data collection. Observational studies are subject to errors attributable to selection bias, confounding, measurement bias, and reverse causation-in addition to errors of chance. Confounding can be statistically controlled to the extent that potential factors are known and accurately measured, but, in practice, bias and unknown confounders usually remain additional potential sources of error, often of unknown magnitude and clinical impact. Causality-the most clinically useful relation between exposure and outcome-can rarely be definitively determined from observational studies because intentional, controlled manipulations of exposures are not involved. In this article, we review several types of observational clinical research: case series, comparative case-control and cohort studies, and hybrid designs in which case-control analyses are performed on selected members of cohorts. We also discuss the analytic issues that arise when groups to be compared in an observational study, such as patients receiving different therapies, are not comparable in other respects.

Lichen sclerosis: clinicopathological study of 60 cases from Lebanon.

PubMed

Knio, Zeina; Kurban, Mazen; Abbas, Ossama

2016-10-01

Lichen sclerosus (LS) is an uncommon idiopathic chronic inflammatory debilitating disease with predilection for the genital region. Our recent encounter with an LS case exhibiting perineural inflammation microscopically prompted us to assess the features of all patients diagnosed with LS at our institution. All cases of LS diagnosed between 1990 and 2014 were retrospectively reviewed. Diagnosis was confirmed with demonstration of microscopic features typical of LS. Sixty patients (42 women and 18 men) with 65 biopsy specimens of LS were identified, of which 41 were extragenital, 16 genital, and three had both. Histopathologically, significantly higher proportions of follicular plugging, atrophy, and vacuolar interface changes were observed in extragenital LS cases, while angiokeratoma-like, mycosis fungoides-like, and pseudoepitheliomatous changes were only seen in genital LS. Perineural inflammation was observed as a novel finding in 22 cases (33.8%) of LS. Features of patients with LS in this study are generally comparable to those published in the literature, with some differences. In contrast to the literature, extragenital LS was more frequently encountered. Histopathologically, perineural inflammation was not an uncommon feature of LS and thus may serve as a clue in the differentiation of LS from its mimickers. © 2016 The International Society of Dermatology.

Case Study: Mini-Case Studies: Small Infusions of Active Learning for Large-Lecture Courses

ERIC Educational Resources Information Center

Carloye, Lisa

2017-01-01

In this article, the author introduces the usage of case studies to be an excellent method for engaging students through stories. The author notes she developed a series of mini-case studies that can be implemented, with a little advance preparation, within a 10- to 15-minute window during lecture. What makes them "mini" case studies?…

Case study of simultaneous observations of sporadic sodium layer, E-region field-aligned irregularities and sporadic E layer at low latitude of China

NASA Astrophysics Data System (ADS)

Xie, H. Y.; Ning, B. Q.; Zhao, X. K.; Hu, L. H.

2017-03-01

Using the Na lidar at Haikou (20.0°N, 110.3°E), the VHF coherent radar and the digital ionosonde both at Sanya (18.4°N, 109.6°E), cases of simultaneous observations of sporadic sodium layer (SSL), E-region field-aligned irregularities (FAI) and sporadic E layer (Es) in the mesosphere and lower thermosphere (MLT) region at low latitude of China are studied. It is found that SSL occurs simultaneously or follows the enhancement of Es and FAI. The Es, FAI and SSL descend slowly with time which is mostly controlled by the diurnal tide (DT). Besides, the interaction of gravity wave (GW) with tides can cause oscillations in FAI and SSL. Our observations support the neutralization of ions for SSL formation: when the metallic ions layer descents to the altitudes where models predict, the sodium ions convert rapidly to atomic Na that may form an SSL event. Moreover, the SSL peak density will increase (decrease) in the convergence (divergence) vertical shear region of zonal wind.

Multiple Case Study of STEM in School-Based Agricultural Education

ERIC Educational Resources Information Center

Stubbs, Eric A.; Myers, Brian E.

2015-01-01

This multiple case study investigated the integration of science, technology, engineering, and mathematics (STEM) in three Florida high school agriculture programs. Observations, interviews, documents, and artifacts provided qualitative data that indicated the types of STEM knowledge taught. Variables of interest included student and teacher…

Making intelligent systems team players: Additional case studies

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

1993-01-01

Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

ADAPTIVE MATCHING IN RANDOMIZED TRIALS AND OBSERVATIONAL STUDIES

PubMed Central

van der Laan, Mark J.; Balzer, Laura B.; Petersen, Maya L.

2014-01-01

SUMMARY In many randomized and observational studies the allocation of treatment among a sample of n independent and identically distributed units is a function of the covariates of all sampled units. As a result, the treatment labels among the units are possibly dependent, complicating estimation and posing challenges for statistical inference. For example, cluster randomized trials frequently sample communities from some target population, construct matched pairs of communities from those included in the sample based on some metric of similarity in baseline community characteristics, and then randomly allocate a treatment and a control intervention within each matched pair. In this case, the observed data can neither be represented as the realization of n independent random variables, nor, contrary to current practice, as the realization of n/2 independent random variables (treating the matched pair as the independent sampling unit). In this paper we study estimation of the average causal effect of a treatment under experimental designs in which treatment allocation potentially depends on the pre-intervention covariates of all units included in the sample. We define efficient targeted minimum loss based estimators for this general design, present a theorem that establishes the desired asymptotic normality of these estimators and allows for asymptotically valid statistical inference, and discuss implementation of these estimators. We further investigate the relative asymptotic efficiency of this design compared with a design in which unit-specific treatment assignment depends only on the units’ covariates. Our findings have practical implications for the optimal design and analysis of pair matched cluster randomized trials, as well as for observational studies in which treatment decisions may depend on characteristics of the entire sample. PMID:25097298

A review of published analyses of case-cohort studies and recommendations for future reporting.

PubMed

Sharp, Stephen J; Poulaliou, Manon; Thompson, Simon G; White, Ian R; Wood, Angela M

2014-01-01

The case-cohort study design combines the advantages of a cohort study with the efficiency of a nested case-control study. However, unlike more standard observational study designs, there are currently no guidelines for reporting results from case-cohort studies. Our aim was to review recent practice in reporting these studies, and develop recommendations for the future. By searching papers published in 24 major medical and epidemiological journals between January 2010 and March 2013 using PubMed, Scopus and Web of Knowledge, we identified 32 papers reporting case-cohort studies. The median subcohort sampling fraction was 4.1% (interquartile range 3.7% to 9.1%). The papers varied in their approaches to describing the numbers of individuals in the original cohort and the subcohort, presenting descriptive data, and in the level of detail provided about the statistical methods used, so it was not always possible to be sure that appropriate analyses had been conducted. Based on the findings of our review, we make recommendations about reporting of the study design, subcohort definition, numbers of participants, descriptive information and statistical methods, which could be used alongside existing STROBE guidelines for reporting observational studies.

Progressing the state of knowledge on the human influence on hydrological droughts through case studies

NASA Astrophysics Data System (ADS)

Rangecroft, Sally; Van Loon, Anne; Bosman, Marianne; Wanders, Niko; Di Baldassarre, Giuliano; AghaKouchak, Amir

2017-04-01

Human activities can have a large influence on changes in the hydrological system and hydrological extremes, more than climate variability and climate change in some cases. However, there are currently only a limited number of studies which aim to quantify the human impact on hydrological droughts. Here we present a synthesis study of existing and new results that aims to summarize and quantify the anthropogenic impact on hydrological drought from case studies and observations. By combining a large number of case studies, we allow conclusions to be drawn about the effects of different human activities. This work suggests ways forward to increase our understanding on how human activities are influencing drought characteristics; invaluable information for water resource management and adaptation. During this project, the impact of different human activities (e.g. water abstraction, reservoir building, urbanisation, etc) on drought frequency, duration and deficit has been calculated in a consistent manner, allowing for an improved understanding to how they have impacted droughts. This consistent methodology is a necessary element for this comparative hydrology exercise, yet we use one which is flexible and applicable to different case study set ups and data availability. The methodology used here depends on available observation data, with three possible approaches: i) paired catchment approach; ii) upstream-downstream comparison; iii) observation modelling framework. The synthesised results of the existing and new case studies cover a number of human activities, hydro-climatic and socio-economic contexts. In particular, we remove the climate dependency in the results by using case studies from multiple climatic regions, including UK, Italy, US, Australia, Mexico and Chile. For groundwater abstraction, it is clear across all the relevant case studies that abstraction activities worsen drought events. This is especially prominent in the deficit volumes, with nearly all

Creating Your Own Case Studies: A Guide for Early Field Experience.

ERIC Educational Resources Information Center

Florio-Ruane, Susan

1990-01-01

A guide for creating case studies is provided for teacher educators to share with students. Suggestions are offered for becoming a participant observer in a classroom. The appendix contains sample appropriate and inappropriate field notes. (SM)

Using non-specialist observers in 4AFC human observer studies

NASA Astrophysics Data System (ADS)

Elangovan, Premkumar; Mackenzie, Alistair; Dance, David R.; Young, Kenneth C.; Wells, Kevin

2017-03-01

Virtual clinical trials (VCTs) are an emergent approach for rapid evaluation and comparison of various breast imaging technologies and techniques using computer-based modeling tools. Increasingly 4AFC (Four alternative forced choice) virtual clinical trials are used to compare detection performances of different breast imaging modalities. Most prior studies have used physicists and/or radiologists and physicists interchangeably. However, large scale use of statistically significant 4AFC observer studies is challenged by the individual time commitment and cost of such observers, often drawn from a limited local pool of specialists. This work aims to investigate whether non-specialist observers can be used to supplement such studies. A team of five specialist observers (medical physicists) and five non-specialists participated in a 4AFC study containing simulated 2D-mammography and DBT (digital breast tomosynthesis) images, produced using the OPTIMAM toolbox for VCTs. The images contained 4mm irregular solid masses and 4mm spherical targets at a range of contrast levels embedded in a realistic breast phantom background. There was no statistically significant difference between the detection performance of medical physicists and non-specialists (p>0.05). However, non-specialists took longer to complete the study than their physicist counterparts, which was statistically significant (p<0.05). Overall, the results from both observer groups indicate that DBT has a lower detectable threshold contrast than 2D-mammography for both masses and spheres, and both groups found spheres easier to detect than irregular solid masses.

Hypercellular round cell liposarcoma: A comprehensive cytomorphologic study and review of 8 cases.

PubMed

Chufal, Sanjay S; Chufal, Kundan S; Pant, Prabhat; Rizvi, Ghazala; Pandey, Hari S; Shahi, Kedar S

2017-01-01

Myxoid and round cell liposarcomas (RCL) are low and high-grade counterparts of a common subtype of liposarcomas (LPS), representing a histologic continuum. The aim was to study the cytomorphology of hypercellular RCL and to look for features that differentiate RCL from other sarcomas displaying round cells with myxoid change. Eight cases of hypercellular RCL were identified retrospectively in which round cell component constituted greater than 75% of the area. Cytomorphological features were studied in detail. Four cases were predominantly composed of round cells, out of which 2 were entirely composed of round cells. Myxoid metachromatic stroma was absent in 2 cases, while it was present in ample amounts in the remaining 6 cases. Spindle cells were completely absent in 5 cases and lipoblasts were observed in a single case of RCL. Plexiform vascular capillaries were seen in 4 cases. Adherence of neoplastic round cells around thin capillaries (ANAC) was observed in 7 cases. Plexiform capillary plexus and ANAC should be separately evaluated. The latter feature is the most consistent one, and is an important clue to the adipocytic nature of the neoplasm when hypercellular round cell areas are aspirated. Confident diagnosis of hypercellular RCL can be made on the basis of this feature. Lipoblasts, although specific, are seen in few cases. The rest of the features are nonspecific and useful only in combination.

Case Studies Behavior Modification.

ERIC Educational Resources Information Center

Wark, David M.

The case histories of five students enrolled in a university course in how to study are reported. The students ranged in age from 18 to 35, included two males and three females, and varied in school experience from no college in one case and some college in two cases to college degrees in two cases. Students were initially taught to chart their…

Student Self-Perceptions of Leadership in Two Missouri FFA Chapters: A Collective Case Study

ERIC Educational Resources Information Center

Kagay, Rachel Bartholomew; Marx, Adam A.; Simonsen, Jon C.

2015-01-01

The focus of this study is the self-perceptions of leadership engagement of FFA members in two FFA chapters in Missouri. This multiple case study used documentation of student self-perceptions, researcher observations, and focus groups. The two cases included 24 high school students comprised of FFA officers and members, who provided their…

[Extra skeletal Ewing's sarcoma. Report of two cases. Ultrastructural study of one case (author's transl)].

PubMed

Krulik, M; Brechot, J M; de Saint-Maur, P; Lecomte, D; Mougeot-Martin, M; Audebert, A A; Zylberait, D; Debray, J

The authors report two cases of extra skeletal Ewing's sarcoma. The first case concerns a 26 years old woman presenting a tumor at the level of the sacrum area, locally recurrent, metastazing to the lungs and the lumbar column, despite of radiotherapy and chemotherapy and leading to death after a course of 18 months. The second one is that of a 30 years old man bearing a tumor of the shoulder area probably already metastazed to bones, rapidly recurrent and metastazing to the lungs and cause of death after 9 months in spite of intensive therapy. About these 2 observations a review of the literature of the cases of extra skeletal Ewing's sarcoma is done. Whatever nosologic discussion it seems that Ewing's sarcoma may present essentially as a tumor of soft tissues. An ultrastructural study has been performed in the second case. The findings are similar to those reported in Ewing's sarcoma.

An observational study of defensible space in the neighbourhood park

NASA Astrophysics Data System (ADS)

Marzukhi, M. A.; Afiq, M. A.; Zaki, S. Ahmad; Ling, O. H. L.

2018-02-01

The planning of neighborhood park is important to provide space for interaction, leisure, and recreation among residents in any neighbourhood area. However, on an almost daily basis, newspapers report inappropriate incidents such as snatch theft, robbery and street attack that occurred in the neighborhood park. These cases reflect the significance of physical planning and design of neighborhood park that directly affect the safety and comfort of the users. Thus, this study attempts to engage with the defensible space concept in ensuring the security elements be applied in the planning of the recreational area. This study adopts a qualitative method form of research that is retrofitted to an observational study. The observational study is significant for revealing the condition of a neighbourhood park in the ‘real-world,’ in which direct observation is conducted on Taman Tasik Puchong Perdana. The observer focused on four elements or variables of defensible space concept including the provision of facilities in the neighborhood park, territoriality, surveillance, image and milieu. The findings revealed that the planning of Taman Tasik Puchong Perdana does not deliberate the defensible space elements, which may contribute to the crime activities in the park. In these circumstances, the planning of neighbourhood park needs to include proposals for the implementation of defensible space in response to the challenges underpinned by crime problems. Besides, the awareness among the residents needs to be emphasized with the support from local authorities and other organizations to manage and sustain the safety environment in the neighborhood park.

How To Set Up Your Own Small Business. Service Company Case Study. Manufacturing Firm Case Study. Retail Store Case Study.

ERIC Educational Resources Information Center

Fallek, Max

This collection of case studies is intended for use in a course in setting up a small business. The first, a case study of the process of setting up a service company, covers analyzing the pros and cons of starting one's own business, assessing the competition and local market, and selecting a site for and financing the business. The principal…

Natural Learning Case Study Archives

ERIC Educational Resources Information Center

Lawler, Robert W.

2015-01-01

Natural Learning Case Study Archives (NLCSA) is a research facility for those interested in using case study analysis to deepen their understanding of common sense knowledge and natural learning (how the mind interacts with everyday experiences to develop common sense knowledge). The database comprises three case study corpora based on experiences…

A Case Study on Teaching of Energy as a Subject for 9th Graders

ERIC Educational Resources Information Center

Bezen, Sevim; Bayrak, Celal; Aykutlu, Isil

2017-01-01

This study aims to describe how energy subject is taught in 9th grades. The study is designed as a descriptive case study with the participation of 3 physics teachers and 85 students. Data were obtained through observation, interviews, and documents, and they were analyzed through descriptive analysis method. In the observations made at the…

Transformative Learning through Education Abroad: A Case Study of a Community College Program

ERIC Educational Resources Information Center

Brenner, Ashley A.

2014-01-01

This case study examined how participating in a short-term education abroad program fostered transformative learning for a small group of community college students. As a participant-observer, I utilized ethnographic methods, including interviews, observations, and document analysis, to understand students' perceptions of their experiences…

A methodology to estimate representativeness of LAI station observation for validation: a case study with Chinese Ecosystem Research Network (CERN) in situ data

NASA Astrophysics Data System (ADS)

Xu, Baodong; Li, Jing; Liu, Qinhuo; Zeng, Yelu; Yin, Gaofei

2014-11-01

Leaf Area Index (LAI) is known as a key vegetation biophysical variable. To effectively use remote sensing LAI products in various disciplines, it is critical to understand the accuracy of them. The common method for the validation of LAI products is firstly establish the empirical relationship between the field data and high-resolution imagery, to derive LAI maps, then aggregate high-resolution LAI maps to match moderate-resolution LAI products. This method is just suited for the small region, and its frequencies of measurement are limited. Therefore, the continuous observing LAI datasets from ground station network are important for the validation of multi-temporal LAI products. However, due to the scale mismatch between the point observation in the ground station and the pixel observation, the direct comparison will bring the scale error. Thus it is needed to evaluate the representativeness of ground station measurement within pixel scale of products for the reasonable validation. In this paper, a case study with Chinese Ecosystem Research Network (CERN) in situ data was taken to introduce a methodology to estimate representativeness of LAI station observation for validating LAI products. We first analyzed the indicators to evaluate the observation representativeness, and then graded the station measurement data. Finally, the LAI measurement data which can represent the pixel scale was used to validate the MODIS, GLASS and GEOV1 LAI products. The result shows that the best agreement is reached between the GLASS and GEOV1, while the lowest uncertainty is achieved by GEOV1 followed by GLASS and MODIS. We conclude that the ground station measurement data can validate multi-temporal LAI products objectively based on the evaluation indicators of station observation representativeness, which can also improve the reliability for the validation of remote sensing products.

A methodological review of qualitative case study methodology in midwifery research.

PubMed

Atchan, Marjorie; Davis, Deborah; Foureur, Maralyn

2016-10-01

To explore the use and application of case study research in midwifery. Case study research provides rich data for the analysis of complex issues and interventions in the healthcare disciplines; however, a gap in the midwifery research literature was identified. A methodological review of midwifery case study research using recognized templates, frameworks and reporting guidelines facilitated comprehensive analysis. An electronic database search using the date range January 2005-December 2014: Maternal and Infant Care, CINAHL Plus, Academic Search Complete, Web of Knowledge, SCOPUS, Medline, Health Collection (Informit), Cochrane Library Health Source: Nursing/Academic Edition, Wiley online and ProQuest Central. Narrative evaluation was undertaken. Clearly worded questions reflected the problem and purpose. The application, strengths and limitations of case study methods were identified through a quality appraisal process. The review identified both case study research's applicability to midwifery and its low uptake, especially in clinical studies. Many papers included the necessary criteria to achieve rigour. The included measures of authenticity and methodology were varied. A high standard of authenticity was observed, suggesting authors considered these elements to be routine inclusions. Technical aspects were lacking in many papers, namely a lack of reflexivity and incomplete transparency of processes. This review raises the profile of case study research in midwifery. Midwives will be encouraged to explore if case study research is suitable for their investigation. The raised profile will demonstrate further applicability; encourage support and wider adoption in the midwifery setting. © 2016 John Wiley & Sons Ltd.

The Use of Interrupted Case Studies to Enhance Critical Thinking Skills in Biology

PubMed Central

White, Tracy K.; Whitaker, Paul; Gonya, Terri; Hein, Richard; Kroening, Dubear; Lee, Kevin; Lee, Laura; Lukowiak, Andrea; Hayes, Elizabeth

2009-01-01

There has been a dramatic increase in the availability of case studies for use in the biology classroom, and perceptions of the effectiveness of case-study-based learning are overwhelmingly positive. Here we report the results of a study in which we evaluated the ability of interrupted case studies to improve critical thinking in the context of experimental design and the conventions of data interpretation. Students were assessed using further case studies designed to evaluate their ability to recognize and articulate problematic approaches to these elements of experimentation. Our work reveals that case studies have broad utility in the classroom. In addition to demonstrating a small but statistically significant increase in the number of students capable of critically evaluating selected aspects of experimental design, we also observed increased student engagement and documented widespread misconceptions regarding the conventions of data acquisition and analysis. PMID:23653687

Diagnostic Hysteroscopy - A Retrospective Study of 1545 Cases

PubMed Central

STEFANESCU, Andreea; MARINESCU, Bogdan

2012-01-01

ABSTRACT Introduction: The development of hysteroscopy has provided a minimally invasive approach to common gynecologic problems, such as abnormal uterine bleeding. Diagnostic hysteroscopy is considered now "the gold standard" by the Association of Professors of Gynecology and Obstetrics (2002) in investigation of abnormal uterine bleeding (AUB) in order to rule out organic endouterine causes of AUB. Although the World Health Organization (WHO) recommends hysterosapingography (HSG) alone for management of infertile women many specialists use hysteroscopy as a first-line routine exam for infertility patients regardless of guidelines. Material and method: This paper is a retrospective study of 1545 diagnostic hysteroscopies performed in the "Prof. Dr. Panait Sirbu" Obstetrics and Gynecology Hospital between January 1, 2008 and June 30, 2011. The following parameters were studied: diagnostic hysteroscopy indications, type of anesthesia used, correlation between pre-and postoperative diagnoses. Outcomes: Of 1545 diagnostic hysteroscopies, 78% of cases were performed without anesthesia; of the total of 299 cases of primary infertility diagnostic hysteroscopy showed in 34% of cases tubal obstruction and endouterine pathology; of the total 396 cases of secondary infertility under investigation, diagnostic hysteroscopy showed in 40% of cases tubal obstruction and endouterine pathology; the highest accuracy of HSG was noted for uterine malformation and minimal accuracy was observed for intrauterine adhesions. Conclusions: Our experience supports the opinion that diagnostic hysteroscopy should be a first-line routine exam in infertility. Because of the high rate of false positive results for HSG in our study and considering the other studies in specialty literature, we always perform a diagnostic hysteroscopy before Assisted Human Reproduction procedures regardless of the HSG aspect. PMID:23483793

Hydro-geophysical observations integration in numerical model: case study in Mediterranean karstic unsaturated zone (Larzac, france)

NASA Astrophysics Data System (ADS)

Champollion, Cédric; Fores, Benjamin; Le Moigne, Nicolas; Chéry, Jean

2016-04-01

Karstic hydro-systems are highly non-linear and heterogeneous but one of the main water resource in the Mediterranean area. Neither local measurements in boreholes or analysis at the spring can take into account the variability of the water storage. Since a few years, ground-based geophysical measurements (such as gravity, electrical resistivity or seismological data) allows following water storage in heterogeneous hydrosystems at an intermediate scale between boreholes and basin. Behind classical rigorous monitoring, the integration of geophysical data in hydrological numerical models in needed for both processes interpretation and quantification. Since a few years, a karstic geophysical observatory (GEK: Géodésie de l'Environnement Karstique, OSU OREME, SNO H+) has been setup in the Mediterranean area in the south of France. The observatory is surrounding more than 250m karstified dolomite, with an unsaturated zone of ~150m thickness. At the observatory water level in boreholes, evapotranspiration and rainfall are classical hydro-meteorological observations completed by continuous gravity, resistivity and seismological measurements. The main objective of the study is the modelling of the whole observation dataset by explicit unsaturated numerical model in one dimension. Hydrus software is used for the explicit modelling of the water storage and transfer and links the different observations (geophysics, water level, evapotranspiration) with the water saturation. Unknown hydrological parameters (permeability, porosity) are retrieved from stochastic inversions. The scale of investigation of the different observations are discussed thank to the modelling results. A sensibility study of the measurements against the model is done and key hydro-geological processes of the site are presented.

The Pericles Space Case: Preserving Earth Observation Data for the Future

NASA Astrophysics Data System (ADS)

Muller, C.; Pandey, P.; Pericles Consortium

2016-08-01

PERICLES (Promoting and Enhancing the Reuse of Information throughout the Content Lifecycle exploiting Evolving Semantics) is an FP7 project started on February 2013. It aims at preserving by design large and complex data sets. PERICLES is coordinated by King's College London, UK and its partners are University of Borås (Sweden), CERT (Greece), DotSoft(Greece), GeorgAugustUniversität, Göttingen (Germany), University of Liverpool (UK), Space Application Services (Belgium), XEROX France and University of Edinburgh (UK). Two additional partners provide the case studies: Tate Gallery (UK) brings the digital art and media case study and B.USOC (Belgian Users Support and Operations Centre) brings the space science case study.

The effectiveness of the mumps component of the MMR vaccine: a case control study.

PubMed

Harling, Richard; White, Joanne M; Ramsay, Mary E; Macsween, Karen F; van den Bosch, Corry

2005-07-01

In 1998/1999, an outbreak of mumps occurred among children of a religious community in North East London. A case control study was conducted to assess the effectiveness of the mumps component of the MMR vaccine. One hundred and sixty-one cases of mumps were identified and 192 controls were selected. Fifty-one percent of cases and 77% of controls had a history at least one MMR vaccination. The observed effectiveness of any MMR vaccination adjusted for age, sex and general practice was 69% (95% CI: 41-84%). This is consistent with the results of other observational studies of mumps containing vaccines, but lower than the immunogenicity of mumps vaccines reported by clinical trials. This discrepancy is because observational studies tend to underestimate vaccine effectiveness, and because immunogenicity is not necessarily an accurate biological marker of vaccine effectiveness. Two doses of vaccine were more effective (88% (95% CI: 62-96%)) than a single dose (64% (95% CI: 40-78%)). The current two-dose vaccination programme remains the best method for controlling mumps infection in the community.

Recent Plasma Observations Related to Magnetic Merging and the Low-Latitude Boundary Layer. Case Study by Polar, March 18, 2006

NASA Technical Reports Server (NTRS)

Chandler, M.; Avanov, L.; Craven, P.; Mozer, F.; Moore, T. E.

2007-01-01

We have begun an investigation of the nature of the low-latitude boundary layer in the mid-altitude cusp region using data from the Polar spacecraft. Magnetosheath-like plasma is frequently observed deep (in terms of distance from the magnetopause and in invariant latitude) in the magnetosphere. One such case, taken during a long period of northward interplanetary magnetic field (IMP) on March 18, 2006, shows injected magnetosheath ions within the magnetosphere with velocity distributions resulting from two separate merging sites along the same field lines. Cold ionospheric ions were also observed counterstreaming along the field lines, evidence that these field lines were closed. Our results support the idea of double reconnection under northward IMP on the same group of field lines can provide a source for the LLBL. However, the flow direction of the accelerated magnetosheath ions antiparallel to the local magnetic field and given location of the spacecraft suggest that these two injection sites are located northward of the spacecraft position. Observed convection velocities of the magnetic field lines are inconsistent with those expected for double post-cusp reconnection in both hemispheres. These observations favor a scenario in which a group of newly closed field lines was created by a combination of high shear merging at high latitudes in the northern hemisphere and low shear merging at lower latitudes at the dayside magnetopause.

The Management of Training in Multinational Corporations: Comparative Case Studies.

ERIC Educational Resources Information Center

Noble, Charles

1997-01-01

Case studies of British and Australian multinational corporations in the food and drink industry investigated how training and development are managed. Competency-based education and industry boards are important elements in both countries. Lack of a training culture in the industry and little innovation in training were observed. (SK)

Transparency of the 2 μm window on Titan studied with observations made by VIMS

NASA Astrophysics Data System (ADS)

Rannou, P.; Lemouélic, S.; Sotin, C.; Brown, R. H.

2012-09-01

The study of Titan properties with remote sensing relies on a good knowledge of the atmosphere properties. The in-situ observations made by Huygens combined with recent advances in the definition of methane properties enable to model and interpret observations with a very good accuracy. However, intensity at some wavelengths are poorly modeled because additional opacities must be studied. We focus here on the case of the 2 μm window, which is essential to determined cloud and surface properties.

Palliative care team visits. Qualitative study through participant observation.

PubMed

Alfaya Góngora, Maria Del Mar; Bueno Pernias, Maria José; Hueso Montoro, César; Guardia Mancilla, Plácido; Montoya Juárez, Rafael; García Caro, Maria Paz

2016-03-30

To describe the clinical encounters that occur when a palliative care team provides patient care and the features that influence these encounters and indicate whether they are favorable or unfavorable depending on the expectations and feelings of the various participants. A qualitative case study conducted via participant observation. A total of 12 observations of the meetings of palliative care teams with patients and families in different settings (home, hospital and consultation room) were performed. The visits were follow-up or first visits, either scheduled or on demand. Content analysis of the observation was performed. The analysis showed the normal follow-up activity of the palliative care unit that was focused on controlling symptoms, sharing information and providing advice on therapeutic regimens and care. The environment appeared to condition the patients' expressions and the type of patient relationship. Favorable clinical encounter conditions included kindness and gratitude. Unfavorable conditions were deterioration caused by approaching death, unrealistic family objectives and limited resources. Home visits from basic palliative care teams play an important role in patient and family well-being. The visits seem to focus on controlling symptoms and are conditioned by available resources.

Palliative care team visits. Qualitative study through participant observation

PubMed Central

Bueno Pernias, Maria José; Hueso Montoro, César; Guardia Mancilla, Plácido; Montoya Juárez, Rafael; García Caro, Maria Paz

2016-01-01

Objectives: To describe the clinical encounters that occur when a palliative care team provides patient care and the features that influence these encounters and indicate whether they are favorable or unfavorable depending on the expectations and feelings of the various participants. Methods: A qualitative case study conducted via participant observation. A total of 12 observations of the meetings of palliative care teams with patients and families in different settings (home, hospital and consultation room) were performed. The visits were follow-up or first visits, either scheduled or on demand. Content analysis of the observation was performed. Results: The analysis showed the normal follow-up activity of the palliative care unit that was focused on controlling symptoms, sharing information and providing advice on therapeutic regimens and care. The environment appeared to condition the patients' expressions and the type of patient relationship. Favorable clinical encounter conditions included kindness and gratitude. Unfavorable conditions were deterioration caused by approaching death, unrealistic family objectives and limited resources. Conclusion: Home visits from basic palliative care teams play an important role in patient and family well-being. The visits seem to focus on controlling symptoms and are conditioned by available resources. PMID:27226663

The impact of science teachers' epistemological beliefs on authentic inquiry: A multiple-case study

NASA Astrophysics Data System (ADS)

Jackson, Dionne Bennett

The purpose of this study was to examine how science teachers' epistemological beliefs impacted their use of authentic inquiry in science instruction. Participants in this multiple-case study included a total of four teachers who represented the middle, secondary and post-secondary levels. Based on the results of the pilot study conducted with a secondary science teacher, adjustments were made to the interview questions and observation protocol. Data collection for the study included semi-structured interviews, direct observations of instructional techniques, and the collection of artifacts. The cross case analysis revealed that the cases epistemological beliefs were mostly Transitional and the method of instruction used most was Discussion. Two of the cases exhibited consistent beliefs and instructional practices, whereas the other two exhibited beliefs beyond their instruction. The findings of this study support the literature on the influence of contextual factors and professional development on teacher beliefs and practice. The findings support and contradict literature relevant to the consistency of teacher beliefs with instruction. This study's findings revealed that the use of reform-based instruction, or Authentic Inquiry, does not occur when science teachers do not have the beliefs and experiences necessary to implement this form of instruction.

The impact of intra-operative interruptions on surgeons' perceived workload: an observational study in elective general and orthopedic surgery.

PubMed

Weigl, Matthias; Antoniadis, Sophia; Chiapponi, Costanza; Bruns, Christiane; Sevdalis, Nick

2015-01-01

Surgeons' intra-operative workload is critical for effective and safe surgical performance. Detrimental conditions in the operating room (OR) environment may add to perceived workload and jeopardize surgical performance and outcomes. This study aims to evaluate the impact of different intra-operative workflow interruptions on surgeons' capacity to manage their workload safely and efficiently. This was an observational study of intra-operative interruptions and self-rated workload in two surgical specialties (general, orthopedic/trauma surgery). Intra-operative interruptions were assessed via expert observation using a well-validated observation tool. Surgeons, nurses, and anesthesiologists assessed their intra-operative workload directly after case completion based on three items of the validated Surgery Task Load Index (mental demand, situational stress, distraction). A total of 56 elective cases (35 open, 21 laparoscopic) with 94 workload ratings were included. Mean intra-operative duration was 1 h 37 min. Intra-operative interruptions were on average observed 9.78 times per hour. People who entered/exited the OR (30.6 %) as well as telephone-/beeper-related disruptions (23.6 %) occurred most often. Equipment and OR environment-related interruptions were associated with highest interference with team functioning particularly in laparoscopic procedures. After identifying task and procedural influences, partial correlational analyses revealed that case-irrelevant communications were negatively associated with surgeons' mental fatigue and situational stress, whereas surgeons' reported distraction was increased by case-irrelevant communication and procedural disruptions. OR nurses' and anesthesiologists' perceived workload was also related to intra-operative interruption events. Our study documents the unique contribution of different interruptions on surgeons' workload; whereas case-irrelevant communications may be beneficial for mental fatigue and stress in routine

Fuzzy-Set Case Studies

ERIC Educational Resources Information Center

Mikkelsen, Kim Sass

2017-01-01

Contemporary case studies rely on verbal arguments and set theory to build or evaluate theoretical claims. While existing procedures excel in the use of qualitative information (information about kind), they ignore quantitative information (information about degree) at central points of the analysis. Effectively, contemporary case studies rely on…

SETDA Case Studies 2012

ERIC Educational Resources Information Center

State Educational Technology Directors Association, 2012

2012-01-01

The State Educational Technology Directors Association (SETDA) published a series of case studies from 28 states to showcase examples of how ARRA EETT ("American Recovery and Reinvestment Act of 2009 Enhancing Education Through Technology") grant funds have impacted teaching and learning. SETDA collected data for the case studies through…

IVHS institutional issues and case studies : ADVANCE case study

DOT National Transportation Integrated Search

1994-04-01

This operational test case study is one of six performed in response to a Volpe National Transportation Systems Center technical task directive (TTD) to Science Applications International Corporation (SAIC) entitled, IVHS Institutional Issues and ...

High School Economics, Cooperative Learning, and the End-of-Course-Test--A Case Study

ERIC Educational Resources Information Center

Beavers, Sharon

2011-01-01

The primary purpose of this twelve-week case study was to explore the use of a cooperative learning strategy with small groups of students in a 12th-grade economics class as diverse learners prepared for tests. The complete case study was based on observations of students, student surveys, focus group interviews, and interviews with educators at…

RACORO Continental Boundary Layer Cloud Investigations: 1. Case Study Development and Ensemble Large-Scale Forcings

NASA Technical Reports Server (NTRS)

Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang;

RACORO continental boundary layer cloud investigations: 1. Case study development and ensemble large-scale forcings

NASA Astrophysics Data System (ADS)

Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang; Li, Zhijin; Xie, Shaocheng; Ackerman, Andrew S.; Zhang, Minghua; Khairoutdinov, Marat

2015-06-01

Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60 h case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in situ measurements from the Routine AAF (Atmospheric Radiation Measurement (ARM) Aerial Facility) CLOWD (Clouds with Low Optical Water Depth) Optical Radiative Observations (RACORO) field campaign and remote sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functions for concise representation in models. Values of the aerosol hygroscopicity parameter, κ, are derived from observations to be 0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing data sets are derived from the ARM variational analysis, European Centre for Medium-Range Weather Forecasts, and a multiscale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in "trial" large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.

Case Study: Guidelines for Producing Videos to Accompany Flipped Cases

ERIC Educational Resources Information Center

Prud'homme-Généreux, Annie; Schiller, Nancy A.; Wild, John H.; Herreid, Clyde Freeman

2017-01-01

Three years ago, the "National Center for Case Study Teaching in Science" (NCCSTS) was inspired to merge the case study and flipped classroom approaches. The resulting project aimed to create the materials required to teach a flipped course in introductory biology by assigning videos as homework and case studies in the classroom. Three…

Clinicopathological study of 81 cases of localized and systemic scleroderma.

PubMed

Succaria, F; Kurban, M; Kibbi, A-G; Abbas, O

2013-02-01

Scleroderma is a connective tissue disease that includes localized and systemic forms. Our recent encounter with a morphea case exhibiting prominent perineural inflammation microscopically prompted us to assess the features of all patients diagnosed with morphea/scleroderma at our institution. To describe the clinicopathological features of all patients diagnosed with morphea/scleroderma at American University of Beirut Medical Center (AUB-MC) between 1999 and 2010, and compare our findings with those published in the literature. A total of 81 cases (63 women and 18 men) were identified, of which 73 were localized (morphea) and eight were systemic scleroderma. Clinically, plaque type morphea was the most common variant both in adults and children, and seven (9%) cases of morphea were associated with lichen sclerosis et atrophicus (LSA). Histopathologically, perineural inflammation was observed in 49% of cases, and may serve, in addition to other features including lichen sclerosis-like changes (observed in exclusively nine cases of morphea), more diffuse dermal and less subcutaneous sclerosis, and intense inflammation, as clues favouring diagnosis of morphea over systemic sclerosis. The features of morphea/scleroderma patients in this study are generally comparable to those published in the literature, with few differences. Clinically, plaque type morphea was the most common variant both in adults and children and LSA was a frequent association. Histopathologically, perineural inflammation was commonly observed and may serve in addition to lichen sclerosis-like changes and intense inflammation as clues favouring diagnosis of morphea over systemic sclerosis. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

Process quality of decision-making in multidisciplinary cancer team meetings: a structured observational study.

PubMed

Hahlweg, Pola; Didi, Sarah; Kriston, Levente; Härter, Martin; Nestoriuc, Yvonne; Scholl, Isabelle

2017-11-17

The quality of decision-making in multidisciplinary team meetings (MDTMs) depends on the quality of information presented and the quality of team processes. Few studies have examined these factors using a standardized approach. The aim of this study was to objectively document the processes involved in decision-making in MDTMs, document the outcomes in terms of whether a treatment recommendation was given (none vs. singular vs. multiple), and to identify factors related to type of treatment recommendation. An adaptation of the observer rating scale Multidisciplinary Tumor Board Metric for the Observation of Decision-Making (MDT-MODe) was used to assess the quality of the presented information and team processes in MDTMs. Data was analyzed using descriptive statistics and mixed logistic regression analysis. N = 249 cases were observed in N = 29 MDTMs. While cancer-specific medical information was judged to be of high quality, psychosocial information and information regarding patient views were considered to be of low quality. In 25% of the cases no, in 64% one, and in 10% more than one treatment recommendations were given (1% missing data). Giving no treatment recommendation was associated with duration of case discussion, duration of the MDTM session, quality of case history, quality of radiological information, and specialization of the MDTM. Higher levels of medical and treatment uncertainty during discussions were found to be associated with a higher probability for more than one treatment recommendation. The quality of different aspects of information was observed to differ greatly. In general, we did not find MDTMs to be in line with the principles of patient-centered care. Recommendation outcome varied substantially between different specializations of MDTMs. The quality of certain information was associated with the recommendation outcome. Uncertainty during discussions was related to more than one recommendation being considered. Time constraints

Bacterial meningitis in Finland, 1995-2014: a population-based observational study.

PubMed

Polkowska, Aleksandra; Toropainen, Maija; Ollgren, Jukka; Lyytikäinen, Outi; Nuorti, J Pekka

2017-06-06

Bacterial meningitis remains an important cause of morbidity and mortality worldwide. Its epidemiological characteristics, however, are changing due to new vaccines and secular trends. Conjugate vaccines against Haemophilus influenzae type b and Streptococcus pneumoniae (10-valent) were introduced in 1986 and 2010 in Finland. We assessed the disease burden and long-term trends of five common causes of bacterial meningitis in a population-based observational study. A case was defined as isolation of S. pneumoniae , Neisseria meningitidis , Streptococcus agalactiae , Listeria monocytogenes or H. influenzae from cerebrospinal fluid and reported to national, population-based laboratory surveillance system during 1995-2014. We evaluated changes in incidence rates (Poisson or negative binomial regression), case fatality proportions (χ 2 ) and age distribution of cases (Wilcoxon rank-sum). During 1995-2014, S. pneumoniae and N. meningitidis accounted for 78% of the total 1361 reported bacterial meningitis cases. H. influenzae accounted for 4% of cases (92% of isolates were non-type b). During the study period, the overall rate of bacterial meningitis per 1 00 000 person-years decreased from 1.88 cases in 1995 to 0.70 cases in 2014 (4% annual decline (95% CI 3% to 5%). This was primarily due to a 9% annual reduction in rates of N. meningitidis (95% CI 7% to 10%) and 2% decrease in S. pneumoniae (95% CI 1% to 4%). The median age of cases increased from 31 years in 1995-2004 to 43 years in 2005-2014 (p=0.0004). Overall case fatality proportion (10%) did not change from 2004 to 2009 to 2010-2014. Substantial decreases in bacterial meningitis were associated with infant conjugate vaccination against pneumococcal meningitis and secular trend in meningococcal meningitis in the absence of vaccination programme. Ongoing epidemiological surveillance is needed to identify trends, evaluate serotype distribution, assess vaccine impact and develop future vaccination strategies

Work Sharing Case Studies.

ERIC Educational Resources Information Center

McCarthy, Maureen E.; And Others

Designed to provide private sector employers with the practical information necessary to select and then to design and implement work sharing arrangements, this book presents case studies of some 36 work sharing programs. Topics covered in the case studies include the circumstances leading to adoption of the program, details of compensation and…

The taxation of unhealthy energy-dense foods (EDFs) and sugar-sweetened beverages (SSBs): An overview of patterns observed in the policy content and policy context of 13 case studies.

PubMed

Hagenaars, Luc Louis; Jeurissen, Patrick Paulus Theodoor; Klazinga, Niek Sieds

2017-08-01

Taxation of energy-dense foods (EDFs) and sugar-sweetened beverages (SSBs) is increasingly of interest as a novel public health and fiscal policy instrument. However academic interest in policy determinants has remained limited. We address this paucity by comparing the policy content and policy context of EDF/SSB taxes witnessed in 13 case studies, of which we assume the tax is sufficiently high to induce behavioural change. The observational and non-randomized studies published on our case studies seem to indicate that the EDF/SSB taxes under investigation generally had the desired effects on prices and consumption of targeted products. The revenue collection of EDF/SSB taxes is minimal yet significant. Administrative practicalities in tax levying are important, possibly explaining why a drift towards solely taxing SSBs can be noted, as these can be demarcated more easily, with levies seemingly increasing in more recent case studies. Despite the growing body of evidence suggesting that EDF/SSB taxes have the potential to improve health, fiscal needs more often seem to lay their policy foundation rather than public health advocacy. A remarkable amount of conservative/liberal governments have adopted these taxes, although in many cases revenues are earmarked for benefits compensating regressive income effects. Governments voice diverse policy rationales, ranging from explicitly describing the tax as a public health instrument, to solely explicating revenue raising. Copyright © 2017 Elsevier B.V. All rights reserved.

The nonlinear behavior of whistler waves at the reconnecting dayside magnetopause as observed by the Magnetospheric Multiscale mission: A case study

NASA Astrophysics Data System (ADS)

Wilder, F. D.; Ergun, R. E.; Newman, D. L.; Goodrich, K. A.; Trattner, K. J.; Goldman, M. V.; Eriksson, S.; Jaynes, A. N.; Leonard, T.; Malaspina, D. M.; Ahmadi, N.; Schwartz, S. J.; Burch, J. L.; Torbert, R. B.; Argall, M. R.; Giles, B. L.; Phan, T. D.; Le Contel, O.; Graham, D. B.; Khotyaintsev, Yu V.; Strangeway, R. J.; Russell, C. T.; Magnes, W.; Plaschke, F.; Lindqvist, P.-A.

2017-05-01

We show observations of whistler mode waves in both the low-latitude boundary layer (LLBL) and on closed magnetospheric field lines during a crossing of the dayside reconnecting magnetopause by the Magnetospheric Multiscale (MMS) mission on 11 October 2015. The whistlers in the LLBL were on the electron edge of the magnetospheric separatrix and exhibited high propagation angles with respect to the background field, approaching 40°, with bursty and nonlinear parallel electric field signatures. The whistlers in the closed magnetosphere had Poynting flux that was more field aligned. Comparing the reduced electron distributions for each event, the magnetospheric whistlers appear to be consistent with anisotropy-driven waves, while the distribution in the LLBL case includes anisotropic backward resonant electrons and a forward resonant beam at near half the electron-Alfvén speed. Results are compared with the previously published observations by MMS on 19 September 2015 of LLBL whistler waves. The observations suggest that whistlers in the LLBL can be both beam and anisotropy driven, and the relative contribution of each might depend on the distance from the X line.

Exposure to organochlorine pesticides and non-Hodgkin lymphoma: a meta-analysis of observational studies

PubMed Central

Luo, Dan; Zhou, Tingting; Tao, Yun; Feng, Yaqian; Shen, Xiaoli; Mei, Surong

2016-01-01

Growing evidence indicates that exposure to organochlorine pesticides (OCPs) could increase non-Hodgkin lymphoma (NHL) risk. However, results from epidemiological studies investigating this association remain controversial. We thus conducted a meta-analysis to quantitatively evaluate the association between OCP exposure and NHL risk. Relevant publications were searched in PubMed, Web of Science, and Embase and identified according to the inclusion criteria. Thirteen studies (6 nested case-control, 1 case-cohort, and 6 case-control) were selected for this meta-analysis. We used odds ratios (ORs) with 95% confidence intervals (CIs) to estimate the relationship between OCPs exposure and NHL risk. The summary OR for included studies was 1.40 (95% CI 1.27 to 1.56). No overall significant heterogeneity in the OR was observed (Ph = 0.253, I2 = 12.6%). Furthermore, OR estimates in subgroup analyses were discussed, and strong associations were observed for dichlorodiphenyldichloroethylene (DDE, OR = 1.38, 95% CI 1.14 to 1.66), hexachlorocyclohexane (HCH, OR = 1.42, 95% CI 1.08 to 1.87), chlordane (OR = 1.93, 95% CI 1.51 to 2.48), and hexachlorobenzene (HCB, OR = 1.54, 95% CI 1.20 to 1.99). This meta-analysis had suggested that total OCPs of interest was significantly positively associated with NHL risk. PMID:27185567

Effectiveness of inactivated quadrivalent influenza vaccine in the 2015/2016 season as assessed in both a test-negative case-control study design and a traditional case-control study design.

PubMed

Kimiya, Takahisa; Shinjoh, Masayoshi; Anzo, Makoto; Takahashi, Hiroki; Sekiguchi, Shinichiro; Sugaya, Norio; Takahashi, Takao

2018-04-21

Both traditional case-control studies (TCCSs) and test-negative case-control studies (TNCCSs) are commonly used to assess influenza vaccine effectiveness (VE). To compensate for the fact that observational studies are susceptible to bias, we combined both methods to assess VE in one geographical area during the 2015/2016 season, when influenza A (H1N1)pdm was dominant. Our TNCCS covered 331 children aged 6 months to 15 years who visited our hospital with fever, including 182 with influenza, and our TCCS covered 812 pediatric outpatients aged 6 months to 15 years, including 214 with influenza. Influenza infection and vaccination history were reviewed, and VE was calculated as (1 - odds ratio) × 100. In the TNCCS, VE against influenza A was 68% (95% CI 47-81) overall, and 70% (48-83) for those given two doses; against influenza B, VE was 37% (- 12-64) overall and 49% (2-74) for two doses. In the TCCS, VE against influenza A was 44% (15-63) overall and 44% (13-64) for two doses, and VE against influenza B was 24% (- 19-52) overall and 41% (3-64) for two doses. Both studies confirmed significant VE against influenza A, significant two-dose VE against influenza B, and better two-dose VE than one-dose VE. What is Known: • Influenza vaccine effectiveness (VE) varies from year to year. • Observational studies are conventionally used for VE assessment. However, they are inherently susceptible to bias and confounding. What is New: • This is the first report of influenza VE assessment using more than one observational study and performed in a specific area during the same season. • VE estimates obtained in our traditional case-control study were lower than those in our test-negative case-control study, but both studies found significant VE against influenza.

Case Study: A Picture Worth a Thousand Words? Making a Case for Video Case Studies

ERIC Educational Resources Information Center

Pai, Aditi

2014-01-01

A picture, they say, is worth a thousand words. If a mere picture is worth a thousand words, how much more are "moving pictures" or videos worth? The author poses this not merely as a rhetorical question, but because she wishes to make a case for using videos in the traditional case study method. She recommends four main approaches of…

A Tale of Three Classes: Case Studies in Course Complexity

ERIC Educational Resources Information Center

Gill, T. Grandon; Jones, Joni

2010-01-01

This paper examines the question of decomposability versus complexity of teaching situations by presenting three case studies of MIS courses. Because all three courses were highly successful in their observed outcomes, the paper hypothesizes that if the attributes of effective course design are decomposable, one would expect to see a large number…

Playing the Literacy Game: A Case Study in Adult Education

ERIC Educational Resources Information Center

Kambouri, Maria; Thomas, Siobhan; Mellar, Harvey

2006-01-01

Runner is a high-quality educational game designed by the University for Industry (UfI/"learndirect") to attract young adults who find learning in formal educational contexts difficult. A case study evaluation of this novel application of an adventure game genre to literacy learning is discussed, based on observations and interviews in…

Constructing Affective Security in Children: Case Study in Educational Environments

ERIC Educational Resources Information Center

Margenat, Montserrat; Dalmau, Mariona; Vendrell, Roser; Ibarz, Lidia

2016-01-01

In line with Bowlby's theoretical approach, where he established a relationship between the quality of experiences lived in the first relationships and subsequent behaviours, we are carrying out a case study research project. The objectives are as follows: (1) To describe interactive patterns as observed in natural contexts and focusing on the…

Traction force during vacuum extraction: a prospective observational study.

PubMed

Pettersson, K; Ajne, J; Yousaf, K; Sturm, D; Westgren, M; Ajne, G

2015-12-01

To investigate the traction force employed during vacuum extractions. Observational cross-sectional study. Obstetric Department, Karolinska University Hospital, Sweden, and the Swedish National Congress of Obstetrics and Gynaecology, 2013. Two hundred women with vacuum extraction at term and 130 obstetricians participating in a simulated setting. In a normal clinical setting, we used a specially adapted device to measure and record the force used to undertake vacuum extraction. In a subsequent part of the study, the force employed for vacuum extraction by a group of obstetricians in a fictive setting was estimated and objectively measured. Applied force during vacuum extraction in relation to the estimated level of difficulty in the delivery; perinatal diagnoses of asphyxia or head trauma; estimated force compared with objectively measured force employed in the fictive setting. The median (minimum-maximum) peak forces for minimum, average and excessive vacuum extraction in the clinical setting were 176 N (5-360 N), 225 N (115-436 N), and 241 N (164-452 N), respectively. In 34% of cases a force in excess of 216 N was employed. There was no correlation between the umbilical arterial pH at delivery and the traction force employed during extraction. Four cases of mild hypoxic ischaemic encephalopathy were observed, three of which were associated with a delivery whereby excessive traction force was employed during the vacuum extraction. In the fictive setting, the actual exerted force was twice the quantitative estimation. The measured forces in the clinical setting were four times higher than that estimated in the fictive setting. Higher than expected levels of traction force were used for vacuum extraction delivery. As obstetricians tend to underestimate the force applied during vacuum extraction, objective measurement with instantaneous feedback may be valuable in raising awareness. © 2015 Royal College of Obstetricians and Gynaecologists.

A case-control study: occupational cooking and the risk of uveal melanoma

PubMed Central

2010-01-01

Background A European-wide population based case-control study (European rare cancer study) undertaken in nine European countries examined risk factors for uveal melanoma. They found a positive association between cooks and the risk of uveal melanoma. In our study we examine whether cooks or people who worked in cook related jobs have an increased uveal melanoma risk. Methods We conducted a case-control study during 2002 and 2005. Overall, 1653 eligible subjects (age range: 20-74 years, living in Germany) participated. Interviews were conducted with 459 incident uveal melanoma cases, 827 population controls, 180 ophthalmologist controls and 187 sibling controls. Data on occupational exposure were obtained from a self-administered postal questionnaire and a computer-assisted telephone interview. We used conditional logistic regression to estimate odds ratios adjusting for the matching factors. Results Overall, we did not observe an increased risk of uveal melanoma among people who worked as cooks or who worked in cook related jobs. When we restricted the source population of our study to the population of the Federal State of Northrhine-Westphalia, we observed an increased risk among subjects who were categorized as cooks in the cases-control analysis. Conclusion Our results are in conflict with former results of the European rare cancer study. Considering the rarity of the disease laboratory in vitro studies of human uveal melanoma cell lines should be done to analyze potential exposure risk factors like radiation from microwaves, strong light from incandescent ovens, or infrared radiation. PMID:20969762

Effectiveness of Three Case Studies and Associated Teamwork in Stimulating Freshman Interest in an Introduction to Engineering Course

ERIC Educational Resources Information Center

McIntyre, Joseph S.

2011-01-01

The effectiveness of three case studies and associated teamwork to stimulate interest of college freshman in engineering was investigated by observing students. Case studies were assigned as laboratory team exercises in an introduction to engineering course at Auburn University. Student interest in the case studies was evaluated qualitatively…

An observational and modeling study of the August 2017 Florida climate extreme event.

NASA Astrophysics Data System (ADS)

Konduru, R.; Singh, V.; Routray, A.

2017-12-01

A special report on the climate extremes by the Intergovernmental Panel on Climate Change (IPCC) elucidates that the sole cause of disasters is due to the exposure and vulnerability of the human and natural system to the climate extremes. The cause of such a climate extreme could be anthropogenic or non-anthropogenic. Therefore, it is challenging to discern the critical factor of influence for a particular climate extreme. Such kind of perceptive study with reasonable confidence on climate extreme events is possible only if there exist any past case studies. A similar rarest climate extreme problem encountered in the case of Houston floods and extreme rainfall over Florida in August 2017. A continuum of hurricanes like Harvey and Irma targeted the Florida region and caused catastrophe. Due to the rarity of August 2017 Florida climate extreme event, it requires the in-depth study on this case. To understand the multi-faceted nature of the event, a study on the development of the Harvey hurricane and its progression and dynamics is significant. Current article focus on the observational and modeling study on the Harvey hurricane. A global model named as NCUM (The global UK Met office Unified Model (UM) operational at National Center for Medium Range Weather Forecasting, India, was utilized to simulate the Harvey hurricane. The simulated rainfall and wind fields were compared with the observational datasets like Tropical Rainfall Measuring Mission rainfall datasets and Era-Interim wind fields. The National Centre for Environmental Prediction (NCEP) automated tracking system was utilized to track the Harvey hurricane, and the tracks were analyzed statistically for different forecasts concerning the Harvey hurricane track of Joint Typhon Warning Centre. Further, the current study will be continued to investigate the atmospheric processes involved in the August 2017 Florida climate extreme event.

Transport of NMHCs and halocarbons observed by CARIBIC: A case study

NASA Astrophysics Data System (ADS)

Baker, A. K.; Brenninkmeijer, C. A. M.; Oram, D. E.; O'Sullivan, D. A.; Schuck, T. J.; Slemr, F.

2009-04-01

The CARIBIC project (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) involves the monthly deployment of an instrument container equipped to make atmospheric measurements from onboard a long-range commercial airliner. Since December 2004, flights for the second phase of CARIBIC have been aboard a Lufthansa Airbus A340-600 traveling between Frankfurt, Germany and destinations in Asia, North America and South America. The instrument package housed in the container is fully automated and during each flight carries out a variety of real-time trace gas and aerosol measurements, and also collects 28 air samples, which are analyzed upon return to the laboratory. Routine measurements made from the sampling flasks include greenhouse gases, nonmethane hydrocarbons (NMHCs), and halocarbons; results of air sample analysis form the basis for the data discussed here. While the majority of CARIBIC samples represent background free tropospheric air and air representative of the upper troposphere/lower stratosphere, the aircraft also, less frequently, encounters air parcels influenced by more recent emissions. Here we present a case study of a round-trip flight between Frankfurt and Toronto, Canada during September 2007. During this flight, different air masses of unique origin were encountered; a number of samples were influenced by transport from the Gulf of Mexico, while others had source regions in Central and Southeast Asia. Samples from the Gulf of Mexico exhibited enhancements in C3-C6 alkanes, as well as a number of halogenated compounds with oceanic sources, such as methyl iodide and bromoform, while Asian samples had enhanced levels of combustion products (CO, acetylene, benzene) and anthropogenic halocarbons (methlyene chloride, chloroform, perchloroethylene). Additionally, a number of samples also showed stratospheric influence, and these samples were characterized by relatively depleted levels of many of the compounds

Dietary patterns are associated with disease risk among participants in the women's health initiative observational study

USDA-ARS?s Scientific Manuscript database

Coronary heart disease (CHD) is the leading cause of death in women. A nested case-control study tested whether dietary patterns predicted CHD events among 1224 participants in the Women’s Health Initiative-Observational Study (WHI-OS) with centrally confirmed CHD, fatal or nonfatal myocardial infar...

A Observational Study of the Internal Structure of Airmass Thunderstorms

NASA Astrophysics Data System (ADS)

Kingsmill, David Edmund

The internal structure of airmass thunderstorms is examined with Doppler and dual-polarization radar, photographic and rawinsonde data from the 1986 MIST project. A kinematic, dynamic and thermodynamic analysis of one well documented case shows a life cycle which closely resembles the Byers and Braham model for airmass storms. Other less detailed cases, examined to supplement this analysis, largely confirm these findings. However, several phenomena never documented for this storm-type are discussed. One of these is a midlevel inflow, which in one case caused a visible constriction in a storm cloud. This inflow appears to arise from the mass compensation required when a strong updraft driven by buoyancy from glaciation forms above a weaker updraft loaded down by the precipitation core. A downdraft at midlevels with an associated "weak-echo" trench is also observed. Its origin appears related to a shear induced wake entrainment process. In addition, microburst intensity surface outflows are observed. The downdrafts responsible for these events appear to be restricted to low levels and to be separate from the midlevel downdraft. One case shows this type of downdraft to be initiated by precipitation loading and intensified by negative thermal buoyancy. In light of these new features, the Byers and Braham model of the cumulus, mature and dissipating stages is reexamined.

Identifying key components for an effective case report poster: an observational study.

PubMed

Willett, Lisa L; Paranjape, Anuradha; Estrada, Carlos

2009-03-01

Residents demonstrate scholarly activity by presenting posters at academic meetings. Although recommendations from national organizations are available, evidence identifying which components are most important is not. To develop and test an evaluation tool to measure the quality of case report posters and identify the specific components most in need of improvement. Faculty evaluators reviewed case report posters and provided on-site feedback to presenters at poster sessions of four annual academic general internal medicine meetings. A newly developed ten-item evaluation form measured poster quality for specific components of content, discussion, and format (5-point Likert scale, 1 = lowest, 5 = highest). Evaluation tool performance, including Cronbach alpha and inter-rater reliability, overall poster scores, differences across meetings and evaluators and specific components of the posters most in need of improvement. Forty-five evaluators from 20 medical institutions reviewed 347 posters. Cronbach's alpha of the evaluation form was 0.84 and inter-rater reliability, Spearman's rho 0.49 (p < 0.001). The median score was 4.1 (Q1 -Q3, 3.7-4.6)(Q1 = 25th, Q3 = 75th percentile). The national meeting median score was higher than the regional meetings (4.4 vs, 4.0, P < 0.001). We found no difference in faculty scores. The following areas were identified as most needing improvement: clearly state learning objectives, tie conclusions to learning objectives, and use appropriate amount of words. Our evaluation tool provides empirical data to guide trainees as they prepare posters for presentation which may improve poster quality and enhance their scholarly productivity.

Design Fixation and Cooperative Learning in Elementary Engineering Design Project: A Case Study

ERIC Educational Resources Information Center

Luo, Yi

2015-01-01

This paper presents a case study examining 3rd, 4th and 5th graders' design fixation and cooperative learning in an engineering design project. A mixed methods instrument, the Cooperative Learning Observation Protocol (CLOP), was adapted to record frequency and class observation on cooperative learning engagement through detailed field notes.…

Palmoplantar Dermatoses- A Clinical Study of 300 Cases

PubMed Central

Rajashekhar, Nadiga; Gejje, Somashekar

2016-01-01

Introduction Dermatoses affecting palms and soles are among the most difficult of all dermatological therapeutic problems. Many previous studies have focused on the specific diseases of palmoplantar dermatoses. However, none of them have included a comprehensive study of palmoplantar dermatoses. Aims: To study the epidemiological aspects like age distribution, sex distribution, the dermatoses affecting the palms & soles and the frequency of involvement of palms, soles or both palms & soles, in patient with palmoplantar dermatoses. Materials and Methods This cross sectional study was conducted in the Department of Dermatology between October 2011 to September 2013. First 300 cases attending the department of dermatology primarily with complaints pertaining to palms and soles were enrolled in the study. After taking consent a detailed history and clinical examination pertaining to the aim of the study was recorded and analysed, which included inspection of morphology and distribution of lesions and palpation of any swelling. Direct microscopic examination of scrapings, wet mounted with 10% potassium hydroxide was done for cases with scaly lesions. Those who had a pustule, gram staining was done. Patch testing using Indian Standard Battery Series was done for those cases of eczema. A sample for biopsy was taken when diagnosis could not be arrived clinically, and subjected to histopathological examination. Results In our study of 300 patients with palmoplantar dermatoses, 164 were females and 136 were males, the ratio observed being 1.2:1. The peak incidence was found in the age group 21-30 years, with 41 females (25%) and 35 males (25.7%). Most frequently affected individuals in this study were housewives (30%). The most common five diseases of palmoplantar dermatoses were palmoplantar psoriasis (20.7%), moniliasis (19%), palmoplantar hyperhidrosis (7%), keratolysis exfoliativa (6%) and pitted keratolysis (6%). Majority of patients had involvement of both palms and

[Acute generalized peritonitis due to uterine perforation following abortion: case study observation].

PubMed

Ka, Ibrahima; Diop, Papa Saloum; Niang, Amadou Bocar; Faye, Alioucoly; Ndoye, Jean Marck; Fall, Babacar

2016-01-01

Clandestine abortion is known to be a major contributor to maternal mortality. We report a case of a 25-year old patient in her 12th week of amenorrhea with peritonitis due to uterine perforation following abortion, admitted with abdomen and pelvis pain, vomiting and diarrhea. Clinical examination on admission showed asthenic peritonitis. Surgical exploration showed widespread acute peritonitis secondary to a perforation of the uterine dome, with collection of 1500 cc of purulent material, dilated bowel loops and multiple false membranes. pus aspiration, peritoneal lavage; uterine suture, drainage. The postoperative course was uneventful, the patient was discharged after 15 days.

[Fanconi disease: study of 43 cases in southern Tunisia].

PubMed

Frikha, M; Mseddi, S; Elloumi, M; Bouaziz, M; Khanfir, A; Mnif, J; Saad, A; Souissi, T

1998-11-01

To report the epidemiologic, clinical, biological features and course of Fanconi's anemia in southern Tunisia. During a period of 12 years we observed 43 cases. For each patient, careful clinical, biological (hemogram, myelogram, bone marrow biopsy, hemoglobin electrophoresis, karyotype) and radiological (skeleton X-rays, abdominal echography and intravenous urography) examinations were performed. All the patients who were at a pancytopenia stage were given androgens. None had a bone marrow allograft. There were 24 girls and 19 boys. The mean age at diagnosis was 10 years and 9 months. The familial character was present in 53% of the cases. The most frequent initial complaint was anemic syndrome (69%). In ten cases (24%), the diagnosis has been established during a familial investigation. Malformations were present in all cases (abnormal pigmentation: 86%; skeletal maturation retardation: 83%; facial dysmorphy: 76%; statural hypotrophy: 65%; bone abnormalities: 53%; renal malformations: 44%). Anemia was present in 88% of the cases, thrombocytopenia and neutropenia in all cases. Bone marrow was hypoplastic or aplastic in all cases on biopsies. Spontaneous chromosomal breaks were found in 79% of the studied cases. Fetal hemoglobin was increased in 80% of the studied cases with a mean level of 20.5%. Actuarial survival rate at 5 years was 48%, but long survival durations were rare (eight out of 43 patients). This disease, rare in the world, seems to be frequent in southern Tunisia. A normal karyotype (with classical techniques), found in five patients, could not discard the diagnosis; for this reason, the use of sensitizing agents should improve the sensitivity of the test. Besides, an increased level of fetal hemoglobin enabled us to suggest the diagnosis in some cases. Androgenotherapy increased the survival duration to more than 5 years in eight patients. However, bone marrow allograft remains the only possibility of cure.

Homeopathic drug therapy. Homeopathy in Chikungunya Fever and Post-Chikungunya Chronic Arthritis: an observational study.

PubMed

Wadhwani, Gyandas G

2013-07-01

To observe the effect of homeopathic therapy in Chikungunya Fever (CF) and in Post-Chikungunya Chronic Arthritis (PCCA) in a primary health care setting. A prospective observational study was conducted at Delhi Government Homeopathic Dispensary, Aali Village, New Delhi, India, for a period of 6 months, from 1st October 2010 to 31st March 2011. 126 patients (75 CF, 51 PCCA) were enrolled based on predefined inclusion criteria. A single homeopathic medicine was prescribed for each patient after case taking with the help of Materia Medica and/or Repertory. Results were evaluated on the basis of visual analogue scale and symptom scores. Complete recovery was seen in 84.5% CF cases in a mean time of 6.8 days. 90% cases of PCCA recovered completely in a mean time of 32.5 days. Homeopathic therapy may be effective in CF and PCCA. A randomized controlled trial should be considered. Copyright © 2013 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Clinicopathologic analysis of 21 cases of nevus sebaceus: a retrospective study.

PubMed

Simi, C M; Rajalakshmi, T; Correa, Marjorie

2008-01-01

Nevus sebaceus (NS), otherwise designated as 'organoid nevus', involves proliferative changes of the sebaceous glands, sweat glands, and the hair follicles. It displays a range of appearances, depending on the lesion's age. To study the histopathological features of NS and correlate these with clinical findings. All skin biopsy specimens over a 12-year period from 1995 to 2007 which had a diagnosis of NS were included. Clinical data with follow-up notes and histopathology were reviewed. Half of the cases had a verrucous clinical appearance, while the rest presented as papules, plaques, or patches. All the cases showed immature hair follicles, and 24% of cases showed immature sebaceous glands. Normal terminal hair follicles were characteristically absent in the lesion. Nineteen percent of the cases showed dilated apocrine glands, and 14% showed hyperplasia of eccrine glands. Epidermal changes in the form of acanthosis, papillomatosis, and hyperkeratosis were seen in 86% of cases. Dilated keratin-filled infundibula were observed in 24% of cases. One case was associated with a squamous cell carcinoma. Nevus sebaceus is a cutaneous hamartoma, consisting of various elements indigenous to the organ. Normal terminal hair follicles are characteristically absent in the lesion although the same may be seen in rest of the epidermis, a feature of diagnostic importance, not usually highlighted in literature. The divergent differentiation observed in NS is consistent with the common embryologic origin of the folliculosebaceous-apocrine unit and should not mislead the pathologist.

Theoretical pluralism in psychoanalytic case studies.

PubMed

Willemsen, Jochem; Cornelis, Shana; Geerardyn, Filip M; Desmet, Mattias; Meganck, Reitske; Inslegers, Ruth; Cauwe, Joachim M B D

2015-01-01

The aim of this study is to provide an overview of the scientific activity of different psychoanalytic schools of thought in terms of the content and production of case studies published on ISI Web of Knowledge. Between March 2013 and November 2013, we contacted all case study authors included in the online archive of psychoanalytic and psychodynamic case studies (www.singlecasearchive.com) to inquire about their psychoanalytic orientation during their work with the patient. The response rate for this study was 45%. It appears that the two oldest psychoanalytic schools, Object-relations psychoanalysis and Ego psychology or "Classical psychoanalysis" dominate the literature of published case studies. However, most authors stated that they feel attached to two or more psychoanalytic schools of thought. This confirms that the theoretical pluralism in psychoanalysis stretches to the field of single case studies. The single case studies of each psychoanalytic school are described separately in terms of methodology, patient, therapist, or treatment features. We conclude that published case studies features are fairly similar across different psychoanalytic schools. The results of this study are not representative of all psychoanalytic schools, as some do not publish their work in ISI ranked journals.

Theoretical pluralism in psychoanalytic case studies

PubMed Central

Willemsen, Jochem; Cornelis, Shana; Geerardyn, Filip M.; Desmet, Mattias; Meganck, Reitske; Inslegers, Ruth; Cauwe, Joachim M. B. D.

2015-01-01

The aim of this study is to provide an overview of the scientific activity of different psychoanalytic schools of thought in terms of the content and production of case studies published on ISI Web of Knowledge. Between March 2013 and November 2013, we contacted all case study authors included in the online archive of psychoanalytic and psychodynamic case studies (www.singlecasearchive.com) to inquire about their psychoanalytic orientation during their work with the patient. The response rate for this study was 45%. It appears that the two oldest psychoanalytic schools, Object-relations psychoanalysis and Ego psychology or “Classical psychoanalysis” dominate the literature of published case studies. However, most authors stated that they feel attached to two or more psychoanalytic schools of thought. This confirms that the theoretical pluralism in psychoanalysis stretches to the field of single case studies. The single case studies of each psychoanalytic school are described separately in terms of methodology, patient, therapist, or treatment features. We conclude that published case studies features are fairly similar across different psychoanalytic schools. The results of this study are not representative of all psychoanalytic schools, as some do not publish their work in ISI ranked journals. PMID:26483725

Word Processing in Elementary Schools: Seven Case Studies. Education and Technology Series.

ERIC Educational Resources Information Center

Murray, Jack; And Others

As a result of preliminary observations of word processing in elementary level language the seven case studies presented in this report reveal the effectiveness of current word processing (WP) activities within their respective instructional contexts. Each study is presented separately, detailing the classroom context, tasks and outcomes, program…

Leucocytes telomere length and breast cancer risk/ susceptibility: A case-control study.

PubMed

Pavanello, Sofia; Varesco, Liliana; Gismondi, Viviana; Bruzzi, Paolo; Bolognesi, Claudia

2018-01-01

Telomere length in peripheral blood leukocytes (PBL-TL) was proposed as a biomarker of cancer risk. Recent scientific evidence suggested PBL-TL plays a diverse role in different cancers. Inconsistent results were obtained on PBL-TL in relation to breast cancer risk and specifically to the presence of BRCA1 and BRCA2 mutations. The aim of the present case-control study was to analyse the correlation between family history of breast cancer or presence of a BRCA mutation and PBL-TL in the hypothesis that TL is a modifier of cancer risk. PBL-TL was measured using the real-time quantitative PCR method in DNA for 142 cases and 239 controls. All the women enrolled were characterized for cancer family history. A subgroup of 48 women were classified for the presence of a BRCA mutation. PBL-TL were summarized as means and standard deviations, and compared by standard analysis of variance. A multivariable Generalised Linear Model was fitted to the data with PBL-TL as the dependent variable, case/control status and presence of a BRCA/VUS mutation as factors, and age in 4 strata as a covariate. Age was significantly associated with decreasing PBL-TL in controls (p = 0.01), but not in BC cases. The telomere length is shorter in cases than in controls after adjusting for age. No effect on PBL-TL of BMI, smoke nor of the most common risk factors for breast cancer was observed. No association between PBL-TL and family history was detected both in BC cases and controls. In the multivariate model, no association was observed between BRCA mutation and decreased PBL-TL. A statistically significant interaction (p = 0.031) between case-control status and a BRCA-mutation/VUS was observed, but no effect was detected for the interaction of cancer status and BRCA or VUS. Our study fails to provide support to the hypothesis that PBL-TL is associated with the risk of hereditary BC, or that is a marker of inherited mutations in BRCA genes.

Leucocytes telomere length and breast cancer risk/ susceptibility: A case-control study

PubMed Central

Pavanello, Sofia; Varesco, Liliana; Gismondi, Viviana; Bruzzi, Paolo

2018-01-01

Background Telomere length in peripheral blood leukocytes (PBL-TL) was proposed as a biomarker of cancer risk. Recent scientific evidence suggested PBL-TL plays a diverse role in different cancers. Inconsistent results were obtained on PBL-TL in relation to breast cancer risk and specifically to the presence of BRCA1 and BRCA2 mutations. The aim of the present case-control study was to analyse the correlation between family history of breast cancer or presence of a BRCA mutation and PBL-TL in the hypothesis that TL is a modifier of cancer risk. Methods PBL-TL was measured using the real-time quantitative PCR method in DNA for 142 cases and 239 controls. All the women enrolled were characterized for cancer family history. A subgroup of 48 women were classified for the presence of a BRCA mutation. PBL-TL were summarized as means and standard deviations, and compared by standard analysis of variance. A multivariable Generalised Linear Model was fitted to the data with PBL-TL as the dependent variable, case/control status and presence of a BRCA/VUS mutation as factors, and age in 4 strata as a covariate. Results Age was significantly associated with decreasing PBL-TL in controls (p = 0.01), but not in BC cases. The telomere length is shorter in cases than in controls after adjusting for age. No effect on PBL-TL of BMI, smoke nor of the most common risk factors for breast cancer was observed. No association between PBL-TL and family history was detected both in BC cases and controls. In the multivariate model, no association was observed between BRCA mutation and decreased PBL-TL. A statistically significant interaction (p = 0.031) between case-control status and a BRCA-mutation/VUS was observed, but no effect was detected for the interaction of cancer status and BRCA or VUS. Conclusion Our study fails to provide support to the hypothesis that PBL-TL is associated with the risk of hereditary BC, or that is a marker of inherited mutations in BRCA genes. PMID:29782524

Teaching astronomy with case studies

NASA Astrophysics Data System (ADS)

Slater, Timothy F.

2015-11-01

Breaking the students into small, collaborative learning groups to solve a meaningful task together is one of the most successful and fully evaluated teaching techniques implemented over the last century. Although there are many ways to accomplish small group learning, a long-standing and consistently successful collaborative class activity is to use the case study teaching strategy. The use of case studies is common in medical schools and law schools, but not so common in the teaching of astronomy. Case studies create meaningful conversations among students and with the professor by focusing on life-like dilemmas to be solved. Case study tasks ask audience members to synthesize several ideas or evaluate scenarios that have not been explicitly presented to them in the lecture or in available readings.

Interactions between Obsessional Symptoms and Interpersonal Ambivalences in Psychodynamic Therapy: An Empirical Case Study

PubMed Central

Cornelis, Shana; Desmet, Mattias; Van Nieuwenhove, Kimberly L. H. D.; Meganck, Reitske; Willemsen, Jochem; Inslegers, Ruth; Feyaerts, Jasper

2017-01-01

The classical symptom specificity hypothesis (Blatt, 1974) particularly associates obsessional symptoms to interpersonal behavior directed at autonomy and separation from others. Cross-sectional group research, however, has yielded inconsistent findings on this predicted association, and a previous empirical case study (Cornelis et al., in press; see Chapter 2) documented obsessional pathology to be rooted in profound ambivalences between autonomous and dependent interpersonal dynamics. Therefore, in the present empirical case study, concrete operationalizations of the classical symptom specificity hypothesis are contrasted to alternative hypotheses based on the observed complexities in Chapter 2. Dynamic associations between obsessional symptoms and interpersonal functioning is further explored, aiming at further contribution to theory building (i.e., through suggestions for potential hypothesis-refinement; Stiles, 2009). Similar to the first empirical case study (Chapter 1), Consensual Qualitative Research for Case studies is used to quantitatively and qualitatively describe the longitudinal, clinical interplay between obsessional symptoms and interpersonal dynamics throughout the process of supportive-expressive psychodynamic therapy. In line with findings from Chapter 1, findings reveal close associations between obsessions and interpersonal dynamics, and therapist interventions focusing on interpersonal conflicts are documented as related to interpersonal and symptomatic alterations. Observations predominantly accord to the ambivalence-hypothesis rather than to the classical symptom specificity hypothesis. Yet, meaningful differences are observed in concrete manifestations of interpersonal ambivalences within significant relationships. Findings are again discussed in light of conceptual and methodological considerations; and limitations and future research indications are addressed. PMID:28649214

Ways of learning: Observational studies versus experiments

USGS Publications Warehouse

Shaffer, T.L.; Johnson, D.H.

2008-01-01

Manipulative experimentation that features random assignment of treatments, replication, and controls is an effective way to determine causal relationships. Wildlife ecologists, however, often must take a more passive approach to investigating causality. Their observational studies lack one or more of the 3 cornerstones of experimentation: controls, randomization, and replication. Although an observational study can be analyzed similarly to an experiment, one is less certain that the presumed treatment actually caused the observed response. Because the investigator does not actively manipulate the system, the chance that something other than the treatment caused the observed results is increased. We reviewed observational studies and contrasted them with experiments and, to a lesser extent, sample surveys. We identified features that distinguish each method of learning and illustrate or discuss some complications that may arise when analyzing results of observational studies. Findings from observational studies are prone to bias. Investigators can reduce the chance of reaching erroneous conclusions by formulating a priori hypotheses that can be pursued multiple ways and by evaluating the sensitivity of study conclusions to biases of various magnitudes. In the end, however, professional judgment that considers all available evidence is necessary to render a decision regarding causality based on observational studies.

Using direct clinical observation to assess the quality of cesarean delivery in Afghanistan: an exploratory study

PubMed Central

2014-01-01

Background As part of a National Emergency Obstetric and Newborn Care (EmONC) Needs Assessment, a special study was undertaken in July 2010 to examine the quality of cesarean deliveries in Afghanistan and examine the utility of direct clinical observation as an assessment method in low-resource settings. Methods This cross-sectional assessment of the quality of cesareans at 14 facilities in Afghanistan included a survey of surgeons regarding their routine cesarean practices, direct observation of 29 cesarean deliveries and comparison of observations with facility records for 34 additional cesareans conducted during the 3 days prior to the observation period at each facility. For both observed cases and record reviews, we assessed time intervals between specified points of care-arrival to the ward, first evaluation, detection of a complication, decision for cesarean, incision, and birth. Results All time intervals with the exception of “decision to skin incision” were longer in the record reviews than in observed cases. Prior cesarean was the most common primary indication for all cases. All mothers in both groups observed survived through one hour postpartum. Among newborns there were two stillbirths (7%) in observed births and seven (21%) record reviews. Although our sample is too small to show statistical significance, the difference is noteworthy. In six of the reviewed cesareans resulting in stillbirth, a fetal heart rate was recorded in the operating theater, although four were recorded as macerated. For the two fresh stillbirths, the cesarean surgeries were recorded as scheduled and not urgent. Conclusions Direct observation of cesarean deliveries enabled us to assess a number of preoperative, postoperative, and intraoperative procedures that are often not described in medical records in low resource settings. Comparison of observations with findings from provider interviews and facility records allowed us to infer whether observed practices were typical

Learning in the Making: A Comparative Case Study of Three Makerspaces

ERIC Educational Resources Information Center

Sheridan, Kimberly M.; Halverson, Erica Rosenfeld; Litts, Breanne K.; Brahms, Lisa; Jacobs-Priebe, Lynette; Owens, Trevor

2014-01-01

Through a comparative case study, Sheridan and colleagues explore how makerspaces may function as learning environments. Drawing on field observations, interviews, and analysis of artifacts, videos, and other documents, the authors describe features of three makerspaces and how participants learn and develop through complex design and making…

A case study of intersections between a physics classroom and industry

NASA Astrophysics Data System (ADS)

Jadonath, Capildeo

The purpose of this study was to describe a journey for one teacher and his students. This journey involved bridging the gap between his classroom and high-tech workplaces, while engaging students in an integrated physics curriculum called Advanced Technology Education (ATE). This integrated curriculum is grounded in physics and interwoven with both Principles of Technology (PT) and Integrated Systems Technology (IST). ATE integrates the learning of technical skills, people skills, and academics through real world applications in manufacturing, production and engineering technology. The study was qualitative and employed a specific genre of research, the case study and it included both qualitative and quantitative data collection. This case study design originated from anthropology and has the following four characteristics: particularistic, descriptive, heuristic, and inductive. Data were collected over a 2-year period (August 1996-June 1998), by the researcher who was simultaneously the participants' instructor. This allowed me to be the prime instrument for the study and also become an "insider". The techniques of data collection were guided primarily by the research questions. Multiple sources of evidence included: documents, interviews, archival records, direct observations, participant observations, physical artifacts, and surveys (students, parents, and faculty).

Using Satellite Measurements to Investigate Regional-scale Chemistry: The Case for Geostationary Observations

NASA Technical Reports Server (NTRS)

Fishman, Jack; Wozniak, Amy; Creilson, Jack

2007-01-01

One of the recommendations of the Decadal Survey that was recently released by the National Academy of Science was that of a geostationary platform from which to obtain trace gas measurements. The use of such a platform is particularly advantageous when applied to understanding the formation of regional air pollution. This study demonstrates the challenges of trying to utilize information from instruments on satellites in low-earth orbit (LEO). We also demonstrate the advantage gained through a simulation that would provide hourly observations. In this case study, we take advantage of the high resolution Level-2 orbital data available from the Ozone Monitoring Instrument (OMI), in conjunction with assimilated stratospheric column ozone fields, to evaluate if meaningful tropospheric ozone information can be obtained on a regional scale. We focus on a period on late June 2005 when a widespread pollution episode enveloped the Houston metropolitan area as well as a large region in southeast Texas.

Identifying Key Components for an Effective Case Report Poster: An Observational Study

PubMed Central

Paranjape, Anuradha; Estrada, Carlos

2008-01-01

BACKGROUND Residents demonstrate scholarly activity by presenting posters at academic meetings. Although recommendations from national organizations are available, evidence identifying which components are most important is not. OBJECTIVE To develop and test an evaluation tool to measure the quality of case report posters and identify the specific components most in need of improvement. DESIGN Faculty evaluators reviewed case report posters and provided on-site feedback to presenters at poster sessions of four annual academic general internal medicine meetings. A newly developed ten-item evaluation form measured poster quality for specific components of content, discussion, and format (5-point Likert scale, 1 = lowest, 5 = highest). Main outcome measure(s): Evaluation tool performance, including Cronbach alpha and inter-rater reliability, overall poster scores, differences across meetings and evaluators and specific components of the posters most in need of improvement. RESULTS Forty-five evaluators from 20 medical institutions reviewed 347 posters. Cronbach’s alpha of the evaluation form was 0.84 and inter-rater reliability, Spearman’s rho 0.49 ( < 0.001). The median score was 4.1 (Q1 -Q3, 3.7-4.6)(Q1 = 25th, Q3 = 75th percentile). The national meeting median score was higher than the regional meetings (4.4 vs, 4.0,  < 0.001). We found no difference in faculty scores. The following areas were identified as most needing improvement: clearly state learning objectives, tie conclusions to learning objectives, and use appropriate amount of words. CONCLUSIONS Our evaluation tool provides empirical data to guide trainees as they prepare posters for presentation which may improve poster quality and enhance their scholarly productivity. PMID:19089510

Case Studies in Wilderness Medicine.

ERIC Educational Resources Information Center

Gray, Melissa; Tarter, Shana Lee

Five case studies explore issues in wilderness medicine, with emphasis on evacuation decision making. The cases describe medical problems encountered during wilderness trips involving college or high school students. In each case, the situation and facts of the case are outlined, including the patient's medical history and vital signs, and at…

Ambient observations of hygroscopic growth factor and f(RH) below 1: Case studies from surface and airborne measurements

NASA Astrophysics Data System (ADS)

Shingler, Taylor; Sorooshian, Armin; Ortega, Amber; Crosbie, Ewan; Wonaschütz, Anna; Perring, Anne E.; Beyersdorf, Andreas; Ziemba, Luke; Jimenez, Jose L.; Campuzano-Jost, Pedro; Mikoviny, Tomas; Wisthaler, Armin; Russell, Lynn M.

2016-11-01

This study reports a detailed set of ambient observations of optical/physical shrinking of particles from exposure to water vapor with consistency across different instruments and regions. Data have been utilized from (i) a shipboard humidified tandem differential mobility analyzer during the Eastern Pacific Emitted Aerosol Cloud Experiment in 2011, (ii) multiple instruments on the NASA DC-8 research aircraft during the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys in 2013, and (iii) the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe during ambient measurements in Tucson, Arizona, during summer 2014 and winter 2015. Hygroscopic growth factor (ratio of humidified-to-dry diameter, GF = Dp,wet/Dp,dry) and f(RH) (ratio of humidified-to-dry scattering coefficients) values below 1 were observed across the range of relative humidity (RH) investigated (75-95%). A commonality of observations of GF and f(RH) below 1 in these experiments was the presence of particles enriched with carbonaceous matter, especially from biomass burning. Evidence of externally mixed aerosol, and thus multiple GFs with at least one GF < 1, was observed concurrently with f(RH) < 1 during smoke periods. Possible mechanisms responsible for observed shrinkage are discussed and include particle restructuring, volatilization effects, and refractive index modifications due to aqueous processing resulting in optical size modification. To further investigate ambient observations of GFs and f(RH) values less than 1, it is recommended to add an optional prehumidification bypass module to hygroscopicity instruments, to preemptively collapse particles prior to controlled RH measurements.

Study of the Effects of Total Modulation Transfer Function Changes on Observer Performance Using Clinical Mammograms.

NASA Astrophysics Data System (ADS)

Bencomo, Jose Antonio Fagundez

The main goal of this study was to relate physical changes in image quality measured by Modulation Transfer Function (MTF) to diagnostic accuracy. One Hundred and Fifty Kodak Min-R screen/film combination conventional craniocaudal mammograms obtained with the Pfizer Microfocus Mammographic system were selected from the files of the Department of Radiology, at M.D. Anderson Hospital and Tumor Institute. The mammograms included 88 cases with a variety of benign diagnosis and 62 cases with a variety of malignant biopsy diagnosis. The average age of the patient population was 55 years old. 70 cases presented calcifications with 30 cases having calcifications smaller than 0.5mm. 46 cases presented irregular bordered masses larger than 1 cm. 30 cases presented smooth bordered masses with 20 larger than 1 cm. Four separated copies of the original images were made each having a different change in the MTF using a defocusing technique whereby copies of the original were obtained by light exposure through different thicknesses (spacing) of transparent film base. The mammograms were randomized, and evaluated by three experienced mammographers for the degree of visibility of various anatomical breast structures and pathological lesions (masses and calicifications), subjective image quality, and mammographic interpretation. 3,000 separate evaluations were anayzed by several statistical techniques including Receiver Operating Characteristic curve analysis, McNemar test for differences between proportions and the Landis et al. method of agreement weighted kappa for ordinal categorical data. Results from the statistical analysis show: (1) There were no statistical significant differences in the diagnostic accuracy of the observers when diagnosing from mammograms with the same MTF. (2) There were no statistically significant differences in diagnostic accuracy for each observer when diagnosing from mammograms with the different MTF's used in the study. (3) There statistical

Mechanism of case processing in the brain: an fMRI study.

PubMed

Yokoyama, Satoru; Maki, Hideki; Hashimoto, Yosuke; Toma, Masahiko; Kawashima, Ryuta

2012-01-01

In sentence comprehension research, the case system, which is one of the subsystems of the language processing system, has been assumed to play a crucial role in signifying relationships in sentences between noun phrases (NPs) and other elements, such as verbs, prepositions, nouns, and tense. However, so far, less attention has been paid to the question of how cases are processed in our brain. To this end, the current study used fMRI and scanned the brain activity of 15 native English speakers during an English-case processing task. The results showed that, while the processing of all cases activates the left inferior frontal gyrus and posterior part of the middle temporal gyrus, genitive case processing activates these two regions more than nominative and accusative case processing. Since the effect of the difference in behavioral performance among these three cases is excluded from brain activation data, the observed different brain activations would be due to the different processing patterns among the cases, indicating that cases are processed differently in our brains. The different brain activations between genitive case processing and nominative/accusative case processing may be due to the difference in structural complexity between them.

Determining whether metals nucleate homogeneously on graphite: A case study with copper

DOE PAGES

Appy, David; Lei, Huaping; Han, Yong; ...

2014-11-05

In this study, we observe that Cu clusters grow on surface terraces of graphite as a result of physical vapor deposition in ultrahigh vacuum. We show that the observation is incompatible with a variety of models incorporating homogeneous nucleation and calculations of atomic-scale energetics. An alternative explanation, ion-mediated heterogeneous nucleation, is proposed and validated, both with theory and experiment. This serves as a case study in identifying when and whether the simple, common observation of metal clusters on carbon-rich surfaces can be interpreted in terms of homogeneous nucleation. We describe a general approach for making system-specific and laboratory-specific predictions.

Reporting of methodological features in observational studies of pre-harvest food safety.

PubMed

Sargeant, Jan M; O'Connor, Annette M; Renter, David G; Kelton, David F; Snedeker, Kate; Wisener, Lee V; Leonard, Erin K; Guthrie, Alessia D; Faires, Meredith

2011-02-01

Observational studies in pre-harvest food safety may be useful for identifying risk factors and for evaluating potential mitigation strategies to reduce foodborne pathogens. However, there are no structured reporting guidelines for these types of study designs in livestock species. Our objective was to evaluate the reporting of observational studies in the pre-harvest food safety literature using guidelines modified from the human healthcare literature. We identified 100 pre-harvest food safety studies published between 1999 and 2009. Each study was evaluated independently by two reviewers using a structured checklist. Of the 38 studies that explicitly stated the observational study design, 27 were described as cross-sectional studies, eight as case-control studies, and three as cohort studies. Study features reported in over 75% of the selected studies included: description of the geographic location of the studies, definitions and sources of data for outcomes, organizational level and source of data for independent variables, description of statistical methods and results, number of herds enrolled in the study and included in the analysis, and sources of study funding. However, other features were not consistently reported, including details related to eligibility criteria for groups (such as barn, room, or pen) and individuals, numbers of groups and individuals included in various stages of the study, identification of primary outcomes, the distinction between putative risk factors and confounding variables, the identification of a primary exposure variable, the referent level for evaluation of categorical variable associations, methods of controlling confounding variables and missing variables, model fit, details of subset analysis, demographic information at the sampling unit level, and generalizability of the study results. Improvement in reporting of observational studies of pre-harvest food safety will aid research readers and reviewers in interpreting and

Exploring ESL Teacher Beliefs and Classroom Practices of CLT: A Case Study

ERIC Educational Resources Information Center

Rahman, Mohammad Mosiur; Singh, Manjet Kaur Mehar; Pandian, Ambigapathy

2018-01-01

This paper presents a case study that investigated and compared the stated beliefs and observed classroom practices relating to Communicative Language Teaching (CLT) of two ESL teachers. The findings of the study revealed that both the teachers hold similar complex beliefs that mostly contradict the philosophy of CLT. The practices were not in…

Exploring Teacher Beliefs and Classroom Practices through Reflective Practice: A Case Study

ERIC Educational Resources Information Center

Farrell, Thomas S. C.; Ives, Jessica

2015-01-01

This article presents a case study that explored and reflected on the relationship between the stated beliefs and observed classroom practices of one second language reading teacher. The findings of this study revealed that this particular teacher holds complex beliefs about teaching reading that were evident to some extent in many of his…

TU-FG-209-11: Validation of a Channelized Hotelling Observer to Optimize Chest Radiography Image Processing for Nodule Detection: A Human Observer Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanchez, A; Little, K; Chung, J

Purpose: To validate the use of a Channelized Hotelling Observer (CHO) model for guiding image processing parameter selection and enable improved nodule detection in digital chest radiography. Methods: In a previous study, an anthropomorphic chest phantom was imaged with and without PMMA simulated nodules using a GE Discovery XR656 digital radiography system. The impact of image processing parameters was then explored using a CHO with 10 Laguerre-Gauss channels. In this work, we validate the CHO’s trend in nodule detectability as a function of two processing parameters by conducting a signal-known-exactly, multi-reader-multi-case (MRMC) ROC observer study. Five naive readers scored confidencemore » of nodule visualization in 384 images with 50% nodule prevalence. The image backgrounds were regions-of-interest extracted from 6 normal patient scans, and the digitally inserted simulated nodules were obtained from phantom data in previous work. Each patient image was processed with both a near-optimal and a worst-case parameter combination, as determined by the CHO for nodule detection. The same 192 ROIs were used for each image processing method, with 32 randomly selected lung ROIs per patient image. Finally, the MRMC data was analyzed using the freely available iMRMC software of Gallas et al. Results: The image processing parameters which were optimized for the CHO led to a statistically significant improvement (p=0.049) in human observer AUC from 0.78 to 0.86, relative to the image processing implementation which produced the lowest CHO performance. Conclusion: Differences in user-selectable image processing methods on a commercially available digital radiography system were shown to have a marked impact on performance of human observers in the task of lung nodule detection. Further, the effect of processing on humans was similar to the effect on CHO performance. Future work will expand this study to include a wider range of detection/classification tasks and

Organisational culture and learning: a case study.

PubMed

Bell, Elaine

2013-11-01

To explore the impact organisational cultures have on the learning experience of student nurses and identify the influencing factors. A case study approach was used. The single case being a Defence School of Health Care Studies (DSHCS) and the multiple units of analysis: student nurses, the lecturers and Student Standing Orders. An in depth three dimensional picture was achieved using multiple data collection methods: interview, survey, observation and document analysis. The findings suggest that the DSHCS is perceived to be a sub-culture within a dominant civilian learning culture. Generally, the students and staff believed that the DSHCS is an excellent learning environment and that the defence students overall are high achievers. The common themes that appeared from the data were image, ethos, environment, discipline, support, welfare and a civilian versus military way of thinking. The learning experience of defence student nurses is very positive and enhanced by the positive learning culture of the civilian Higher Educational Institution. The factors influencing a positive learning experience that can be impacted by the overarching culture are discipline, image, ethos of adult learning, support and welfare. Copyright © 2013 Elsevier Ltd. All rights reserved.

RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings

DOE PAGES

Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; ...

2015-06-19

Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60-hour case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in-situ measurements from the RACORO field campaign and remote-sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functionsmore » for concise representation in models. Values of the aerosol hygroscopicity parameter, κ, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing datasets are derived from the ARM variational analysis, ECMWF forecasts, and a multi-scale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in 'trial' large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.« less

Case Studies in Science Ethics

NASA Astrophysics Data System (ADS)

Williams, Karen

2010-03-01

Everyone in science should have ethics education training. I have seen graduate students taken advantage of by their mentors. Many of us have seen misconduct...but what should we do about it? Young scientists are often unaware of the rules in science and make mistakes because of their ignorance of the rules in that particular field of study. Then there are an increasing number of cases in the news of overt cases of misrepresentation in science. All are welcome to attend this discussion of case studies. A case study on topics such as: how to treat data properly, how our values in science affect our work, who gets authorship on scientific papers, who is first author on a paper, what you should do if you uncover misconduct or plagiarism in your university, and we will discuss the scientist's role in society. This will be a painless, non-confrontational small group, then large group discussion of each case

Synoptic study of the seasonal variability of dust cases observed by the TOMS satellite over northern Saudi Arabia

NASA Astrophysics Data System (ADS)

Awad, Adel M.; Mashat, Abdul-Wahab S.; Alamoudi, Ahmad O.; Assiri, Mazen E.

2016-05-01

The aerosol index (AI) from the Total Ozone Mapping Spectrometer (TOMS) satellite and meteorological parameters from National Center for Environmental Prediction and the National Center for Atmospheric Research (NCEP/NCAR) reanalysis datasets were used to examine seasonal dust cases in northern Saudi Arabia. Considering all seasons, winter has the fewest dust cases, whereas summer has the most dust cases. Synoptically, surface high-pressure systems in the eastern and western regions are important for the occurrence of dust cases over the northern Arabian Peninsula. When the eastern high pressure prevails, the effects of the Indian low-pressure system on the Arabian Peninsula are weakened or become nonexistent. The extension of the western high-pressure system toward the southeast provides an opportunity for a low-pressure system over Southeast Africa to connect with the Indian low-pressure system, which increases the width of the low-pressure trough and affects the Arabian Peninsula by increasing the amount of dust over the region. At 850 hPa, the weather systems typically rotate clockwise between winter and autumn. In winter, cyclonic systems prevail in the northern region, while anticyclonic systems prevail in the south. The systems are oriented toward the northeast in spring, the west in summer, and the southeast in autumn. Moreover, northern cyclones at 500 hPa shrink as they move northward and the maximum wind speed at 250 hPa decreases from winter to summer. Furthermore, the case study confirms that a change in the relative strength of the pressure systems and a change in the orientation of the isobars (contours) affect the amount of dust over the area. When the orientation of the isobar (contour) lines become strictly north to south or east to west, the amount of dust decreases and vice versa.

Bacterial meningitis in Finland, 1995–2014: a population-based observational study

PubMed Central

Polkowska, Aleksandra; Toropainen, Maija; Ollgren, Jukka; Lyytikäinen, Outi; Nuorti, J. Pekka

2017-01-01

Objectives Bacterial meningitis remains an important cause of morbidity and mortality worldwide. Its epidemiological characteristics, however, are changing due to new vaccines and secular trends. Conjugate vaccines against Haemophilus influenzae type b and Streptococcus pneumoniae (10-valent) were introduced in 1986 and 2010 in Finland. We assessed the disease burden and long-term trends of five common causes of bacterial meningitis in a population-based observational study. Methods A case was defined as isolation of S. pneumoniae, Neisseria meningitidis, Streptococcus agalactiae, Listeria monocytogenes or H. influenzae from cerebrospinal fluid and reported to national, population-based laboratory surveillance system during 1995–2014. We evaluated changes in incidence rates (Poisson or negative binomial regression), case fatality proportions (χ2) and age distribution of cases (Wilcoxon rank-sum). Results During 1995–2014, S. pneumoniae and N. meningitidis accounted for 78% of the total 1361 reported bacterial meningitis cases. H. influenzae accounted for 4% of cases (92% of isolates were non-type b). During the study period, the overall rate of bacterial meningitis per 1 00 000 person-years decreased from 1.88 cases in 1995 to 0.70 cases in 2014 (4% annual decline (95% CI 3% to 5%). This was primarily due to a 9% annual reduction in rates of N. meningitidis (95% CI 7% to 10%) and 2% decrease in S. pneumoniae (95% CI 1% to 4%). The median age of cases increased from 31 years in 1995–2004 to 43 years in 2005–2014 (p=0.0004). Overall case fatality proportion (10%) did not change from 2004 to 2009 to 2010–2014. Conclusions Substantial decreases in bacterial meningitis were associated with infant conjugate vaccination against pneumococcal meningitis and secular trend in meningococcal meningitis in the absence of vaccination programme. Ongoing epidemiological surveillance is needed to identify trends, evaluate serotype distribution, assess vaccine

Observations of the magnetopause current layer: Cases with no boundary layer and tests of recent models

NASA Technical Reports Server (NTRS)

Eastman, Timothy E.

1995-01-01

theoretical issues have been discussed for over two decades. This is because plasma instruments deployed prior to the ISEE and AMPTE missions did not have the required time resolution and most ISEE investigations to-date have focused on tests of MHD plasma models, especially reconnection. More recently, many phenomenological and theoretical models have been developed to explain the existence and characteristics of the magnetospheric boundary layers with only limited success to date. The cases with no boundary layer treated in this study provide a contrary set of conditions to those observed with a boundary layer. For the measured parameters of such cases, a successful boundary layer model should predict no plasma penetration across the magnetopause. Thus, this research project provides the first direct observational tests of magnetopause models using pristine magnetopause crossings and provides important new results on magnetopause microstructure and associated kinetic processes.

[Pathological and biochemical studies of 30 Niigata autopsy cases related to Minamata disease].

PubMed

Eto, Komyo; Takahashi, Hitoshi; Kakita, Akiyoshi; Tokunaga, Hidehiro; Yasutake, Akira; Nakano, Atsuhiro; Sawada, Masumi; Kinjo, Yoshihide

2007-01-01

To reevaluate pathologically and biochemically 30 autopsy cases related to Minamata disease (MD) in Niigata Prefecture (NP) and compare the findings with those of autopsy cases related to MD in Kumamoto Prefecture (KP). Recently, a set of pathological materials of these 30 autopsy cases has been sent from the Brain Research Institute at the University of Niigata to the National Institute for Minamata Disease (NIMD). The materials from each autopsy case were reexamined at the NIMD. There were no postnatal and fetal cases of MD in the NP autopsy materials. The contents of total mercury (T-Hg), methylmercury (Me-Hg), inorganic mercury (I-Hg) and selenium were measured in the organs of cerebrum, cerebellum, liver and kidney. The contents of T-Hg, Me-Hg and I-Hg were much higher in two cases than in controls. The pathological findings leading to the diagnosis of MD in the NP cases were essentially the same as those in KP, including the peripheral nerve lesions. In the most severely affected case of MD in NP, formation of multiple vacuoles of various sizes was observed in the cerebellar cortex, which was never encountered in the KP cases. The KP lesions were similar to that observed in an acute case of Me-Hg-treated common marmoset studied in the NIMD. The pathological features were essentially the same between the adult cases of MD in NP and KP.

Home Start Evaluation Study. Interim Case Studies IIa.

ERIC Educational Resources Information Center

Fein, Robert

This formative evaluation study of Home Start uses a case study approach. A brief case study focuses on the administrative structure and staff resources and responsibilities of National Home Start. Also included are reports on seven local programs developed after two field visits had been made to each program. In the first visit, objectives chosen…

Business and Consumer Education Case Studies.

ERIC Educational Resources Information Center

Delta Pi Epsilon, Minneapolis, Minn. Phi Chapter.

This publication contains 58 case studies for classroom use in teaching various business and consumer education subjects at the high school level. A supplement to a previous Phi Chapter publication, "Office Education Case Studies" (1973), the case studies are intended to create class discussions and help students acquire the ability to analyze…

Interpreting observational studies: why empirical calibration is needed to correct p-values

PubMed Central

Schuemie, Martijn J; Ryan, Patrick B; DuMouchel, William; Suchard, Marc A; Madigan, David

2014-01-01

Often the literature makes assertions of medical product effects on the basis of ‘ p < 0.05’. The underlying premise is that at this threshold, there is only a 5% probability that the observed effect would be seen by chance when in reality there is no effect. In observational studies, much more than in randomized trials, bias and confounding may undermine this premise. To test this premise, we selected three exemplar drug safety studies from literature, representing a case–control, a cohort, and a self-controlled case series design. We attempted to replicate these studies as best we could for the drugs studied in the original articles. Next, we applied the same three designs to sets of negative controls: drugs that are not believed to cause the outcome of interest. We observed how often p < 0.05 when the null hypothesis is true, and we fitted distributions to the effect estimates. Using these distributions, we compute calibrated p-values that reflect the probability of observing the effect estimate under the null hypothesis, taking both random and systematic error into account. An automated analysis of scientific literature was performed to evaluate the potential impact of such a calibration. Our experiment provides evidence that the majority of observational studies would declare statistical significance when no effect is present. Empirical calibration was found to reduce spurious results to the desired 5% level. Applying these adjustments to literature suggests that at least 54% of findings with p < 0.05 are not actually statistically significant and should be reevaluated. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:23900808

Case Studies

ERIC Educational Resources Information Center

Ritter, Lois A., Ed.; Sue, Valerie M., Ed.

2007-01-01

This article presents two case studies using online surveys for evaluation. The authors begin with an example of a needs assessment survey designed to measure the amount of help new students at a university require in their first year. They then discuss the follow-up survey conducted by the same university to measure the effectiveness of the…

Red and processed meat consumption and risk of glioma in adults: A systematic review and meta-analysis of observational studies

PubMed Central

Saneei, Parvane; Willett, Walter; Esmaillzadeh, Ahmad

2015-01-01

Background: These findings from several observational studies, investigated the association between red meat consumption and gliomas, were inconsistent. We conducted a systematic review and meta-analysis of observational studies to summarize available date on the relation between meat intake and risk of glioma. Materials and Methods: A systematic literature search of relevant reports published until May 2014 of the PubMed/Medline, ISI Web of Knowledge, Excerpta Medica database, Ovid database, Google Scholar, and Scopus databases was conducted. From 723 articles yielded in the preliminary literature search, data from eighteen publications (14 case-control, three cohort, and one nested case-control study) on unprocessed red meat, processed meat, and/or total red meat consumption in relation to glioma in adults were included in the analysis. Quality assessment of studies was performed. Random effects model was used to conduct the meta-analysis. Results: We found a positive significant association between unprocessed red meat intake and risk of glioma (relative risk [RR] = 1.30; 95% confidence interval [CI]: 1.08-1.58) after excluding three studies with uncertain type of brain cancer. This analysis included only one cohort study which revealed no relation between unprocessed red meat intake and glioma (RR = 1.75; 95% CI: 0.35-8.77). Consumption of processed meats was not related to increased risk of glioma in population-based case-control studies (RR = 1.26; 95% CI: 1.05-1.51) and reduced risk in hospital-based case-controls (RR = 0.79; 95% CI: 0.65-0.97). No significant association was seen between processed red meat intake and risk of glioma in cohort studies (RR: 1.08; 95% CI: 0.84-1.37). Total red meat consumption was not associated with risk of adult glioma in case-control or cohort studies. Conclusion: In this meta-analysis of 18 observational studies, we found a modest positive association between unprocessed red meat intake and risk of gliomas based almost

Qualitative Case Study Guidelines

DTIC Science & Technology

2013-11-01

Introduction to Sociological Methods. 2nd ed. New York, McGraw-Hill 14. Denzin , N. K. and Lincoln , Y. S. (2011) The SAGE Handbook of Qualitative...The Art of Science. In: Denzin , N. K. and Lincoln , Y. S. (eds.) Handbook of Qualitative Research. Thousand Oaks, Sage 19. GAO (1990) Case Study...Rinehart & Winston 39. Stake, R. E. (1994) Case Studies. In: Denzin , N. K. and Lincoln , Y. S. (eds.) Handbook of Qualitative Research. Thousand Oaks, Sage

Optimization of medical imaging display systems: using the channelized Hotelling observer for detecting lung nodules: experimental study

NASA Astrophysics Data System (ADS)

Platisa, Ljiljana; Vansteenkiste, Ewout; Goossens, Bart; Marchessoux, Cédric; Kimpe, Tom; Philips, Wilfried

2009-02-01

Medical-imaging systems are designed to aid medical specialists in a specific task. Therefore, the physical parameters of a system need to optimize the task performance of a human observer. This requires measurements of human performance in a given task during the system optimization. Typically, psychophysical studies are conducted for this purpose. Numerical observer models have been successfully used to predict human performance in several detection tasks. Especially, the task of signal detection using a channelized Hotelling observer (CHO) in simulated images has been widely explored. However, there are few studies done for clinically acquired images that also contain anatomic noise. In this paper, we investigate the performance of a CHO in the task of detecting lung nodules in real radiographic images of the chest. To evaluate variability introduced by the limited available data, we employ a commonly used study of a multi-reader multi-case (MRMC) scenario. It accounts for both case and reader variability. Finally, we use the "oneshot" methods to estimate the MRMC variance of the area under the ROC curve (AUC). The obtained AUC compares well to those reported for human observer study on a similar data set. Furthermore, the "one-shot" analysis implies a fairly consistent performance of the CHO with the variance of AUC below 0.002. This indicates promising potential for numerical observers in optimization of medical imaging displays and encourages further investigation on the subject.

Effects of imperfect test sensitivity and specificity on observational studies of influenza vaccine effectiveness.

PubMed

Jackson, Michael L; Rothman, Kenneth J

2015-03-10

The recently developed test-negative design is now standard for observational studies of influenza vaccine effectiveness (VE). It is unclear how influenza test misclassification biases test-negative VE estimates relative to VE estimates from traditional cohort or case-control studies. We simulated populations whose members may develop acute respiratory illness (ARI) due to influenza and to non-influenza pathogens. In these simulations, vaccination reduces the risk of influenza but not of non-influenza ARI. Influenza test sensitivity and specificity, risks of influenza and non-influenza ARI, and VE were varied across the simulations. In each simulation, we estimated influenza VE using a cohort design, a case-control design, and a test-negative design. In the absence of influenza test misclassification, all three designs accurately estimated influenza VE. In the presence of misclassification, all three designs underestimated VE. Bias in VE estimates was slightly greater in the test-negative design than in cohort or case-control designs. Assuming the use of highly sensitive and specific reverse-transcriptase polymerase chain reaction tests for influenza, bias in the test-negative studies was trivial across a wide range of realistic values for VE. Although influenza test misclassification causes more bias in test-negative studies than in traditional cohort or case-control studies, the difference is trivial for realistic combinations of attack rates, test sensitivity/specificity, and VE. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preparing Nursing Home Data from Multiple Sites for Clinical Research – A Case Study Using Observational Health Data Sciences and Informatics

PubMed Central

Boyce, Richard D.; Handler, Steven M.; Karp, Jordan F.; Perera, Subashan; Reynolds, Charles F.

2016-01-01

Introduction: A potential barrier to nursing home research is the limited availability of research quality data in electronic form. We describe a case study of converting electronic health data from five skilled nursing facilities to a research quality longitudinal dataset by means of open-source tools produced by the Observational Health Data Sciences and Informatics (OHDSI) collaborative. Methods: The Long-Term Care Minimum Data Set (MDS), drug dispensing, and fall incident data from five SNFs were extracted, translated, and loaded into version 4 of the OHDSI common data model. Quality assurance involved identifying errors using the Achilles data characterization tool and comparing both quality measures and drug exposures in the new database for concordance with externally available sources. Findings: Records for a total 4,519 patients (95.1%) made it into the final database. Achilles identified 10 different types of errors that were addressed in the final dataset. Drug exposures based on dispensing were generally accurate when compared with medication administration data from the pharmacy services provider. Quality measures were generally concordant between the new database and Nursing Home Compare for measures with a prevalence ≥ 10%. Fall data recorded in MDS was found to be more complete than data from fall incident reports. Conclusions: The new dataset is ready to support observational research on topics of clinical importance in the nursing home including patient-level prediction of falls. The extraction, translation, and loading process enabled the use of OHDSI data characterization tools that improved the quality of the final dataset. PMID:27891528

Effect of temperature and precipitation on salmonellosis cases in South-East Queensland, Australia: an observational study

PubMed Central

Barnett, Adrian Gerard

2016-01-01

Objective Foodborne illnesses in Australia, including salmonellosis, are estimated to cost over $A1.25 billion annually. The weather has been identified as being influential on salmonellosis incidence, as cases increase during summer, however time series modelling of salmonellosis is challenging because outbreaks cause strong autocorrelation. This study assesses whether switching models is an improved method of estimating weather–salmonellosis associations. Design We analysed weather and salmonellosis in South-East Queensland between 2004 and 2013 using 2 common regression models and a switching model, each with 21-day lags for temperature and precipitation. Results The switching model best fit the data, as judged by its substantial improvement in deviance information criterion over the regression models, less autocorrelated residuals and control of seasonality. The switching model estimated a 5°C increase in mean temperature and 10 mm precipitation were associated with increases in salmonellosis cases of 45.4% (95% CrI 40.4%, 50.5%) and 24.1% (95% CrI 17.0%, 31.6%), respectively. Conclusions Switching models improve on traditional time series models in quantifying weather–salmonellosis associations. A better understanding of how temperature and precipitation influence salmonellosis may identify where interventions can be made to lower the health and economic costs of salmonellosis. PMID:26916693

An Observational and modeling strategy to investigate the impact of remote sources on local air quality: A Houston, Texas case study from the Second Texas Air Quality Study (TEXAQS II)

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, W. W.; Pierce, R.; Sparling, L. C.

2010-01-05

Quantifying the impacts of remote sources on individual air quality exceedances remains a significant challenge for air quality forecasting. One goal of the 2006 Texas Air Quality Study (TEXAQS II) was to assess the impact of distant sources on air quality in east Texas. From 23-30 August 2006, retrievals of tropospheric carbon monoxide (CO) from NASA’s Atmospheric InfraRed Sounder (AIRS) reveal the transport of CO from fires in the United States Pacific Northwest to Houston, Texas. This transport occurred behind a cold front and contributed to the worst ozone exceedance period of the summer in the Houston area. We presentmore » supporting satellite observations from the NASA A-Train constellation of the vertical distribution of smoke aerosols and CO. Ground-based in situ CO measurements in Oklahoma and Texas track the CO plume as it moves south and indicate mixing of the aloft plume to the surface by turbulence in the nocturnal boundary layer and convection during the day. Ground-based aerosol speciation and lidar observations do not find appreciable smoke aerosol transport for this case. However, MODIS aerosol optical depths and model simulations indicate some smoke aerosols were transported from the Pacific Northwest through Texas to the Gulf of Mexico. Chemical transport and forward trajectory models confirm the three major observations: (1) the AIRS envisioned CO transport, (2) the satellite determined smoke plume height, and (3) the timing of the observed surface CO increases. Further, the forward trajectory simulations find two of the largest Pacific Northwest fires likely had the most significant impact.« less

Social Competence Intervention in Autistic Spectrum Disorders (ASDS) - A Case Study

ERIC Educational Resources Information Center

Amin, Noor A.; Oweini, Ahmad

2013-01-01

The purpose of this case study was to determine the effectiveness of a combined intervention in remediating the social skills in a first-grader with a disorder from the autism spectrum disorders (ASDs). The researcher also aimed to identify the changes observed during the intervention period. The combined intervention consisted of reading…

Wound healing in pre-tibial injuries--an observation study.

PubMed

McClelland, Heather M; Stephenson, John; Ousey, Karen J; Gillibrand, Warren P; Underwood, Paul

2012-06-01

Pre-tibial lacerations are complex wounds affecting a primarily aged population, with poor healing and a potentially significant impact on social well-being. Management of these wounds has changed little in 20 years, despite significant advances in wound care. A retrospective observational study was undertaken to observe current wound care practice and to assess the effect of various medical factors on wound healing time on 24 elderly patients throughout their wound journey. Wound length was found to be substantively and significantly associated with wound healing time, with a reduction in instantaneous healing rate of about 30% for every increase of 1 cm in wound length. Hence, longer wounds are associated with longer wound healing times. Prescription of several categories of drugs, including those for ischaemic heart disease (IHD), hypertension, respiratory disease or asthma; and the age of the patient were not significantly associated with wound healing times, although substantive significance could be inferred in the case of prescription for IHD and asthma. Despite the small sample size, this study identified a clear association between healing and length of wound. Neither the comorbidities nor prescriptions explored showed any significant association although some seem to be more prevalent in this patient group. The study also highlighted other issues that require further exploration including the social and economic impact of these wounds. © 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Case study: using infrared technology for evidentiary purposes

NASA Astrophysics Data System (ADS)

Jolivet, Noel D.; Hansen, Joel; Miller, John Lester; Beniga, Rico; Austria, Rich

2014-06-01

Infrared technology and imaging systems are already used extensively by the law enforcement (LE) community, typically to gain a tactical advantage or obtain immediate situational awareness. As the use of infrared technology becomes more affordable and widespread, LE is finding new ways to use it and leverage the results in the courtroom as evidence. A case study will be presented where infrared imagery was used to support the Portland Police Bureau (PPB) in prosecuting an individual for a crime where a conviction might not have been assured without said imagery. Tests conducted at FLIR Systems, combined with expert witness testimony by a FLIR employee, helped a jury understand the significance of a key piece of infrared evidence, resulting in a conviction of the criminal. This case was the first Federal case of its kind where infrared imagery was used forensically as evidence and, as such, established precedence. Prior to this, infrared imagery has been offered and debated in court only as to whether it constitutes a legal search. Courtroom observations and lessons learned from this trial have shown that both industry and LE can do a better job of making the prosecution's cases stronger utilizing infrared technology and thus taking criminals off the street.

Case Study: The Chemistry of Cocaine

ERIC Educational Resources Information Center

Dewprashad, Brahmadeo

2011-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's case study focuses on the chemistry of cocaine to teach a number of core concepts in organic chemistry. It also requires that students read and analyze an original research paper on…

Thermal effects of groundwater flow through subarctic fens: A case study based on field observations and numerical modeling

DOE PAGES

Sjöberg, Ylva; Coon, Ethan; K. Sannel, A. Britta; ...

2016-02-04

Modeling and observation of ground temperature dynamics are the main tools for understanding current permafrost thermal regimes and projecting future thaw. Until recently, most studies on permafrost have focused on vertical ground heat fluxes. Groundwater can transport heat in both lateral and vertical directions but its influence on ground temperatures at local scales in permafrost environments is not well understood. In this paper, we combine field observations from a subarctic fen in the sporadic permafrost zone with numerical simulations of coupled water and thermal fluxes. At the Tavvavuoma study site in northern Sweden, ground temperature profiles and groundwater levels weremore » observed in boreholes. These observations were used to set up one- and two-dimensional simulations down to 2 m depth across a gradient of permafrost conditions within and surrounding the fen. Two-dimensional scenarios representing the fen under various hydraulic gradients were developed to quantify the influence of groundwater flow on ground temperature. Our observations suggest that lateral groundwater flow significantly affects ground temperatures. This is corroborated by modeling results that show seasonal ground ice melts 1 month earlier when a lateral groundwater flux is present. Further, although the thermal regime may be dominated by vertically conducted heat fluxes during most of the year, isolated high groundwater flow rate events such as the spring freshet are potentially important for ground temperatures. Finally, as sporadic permafrost environments often contain substantial portions of unfrozen ground with active groundwater flow paths, knowledge of this heat transport mechanism is important for understanding permafrost dynamics in these environments.« less

Assembling a Case Study Tool Kit: 10 Tools for Teaching with Cases

ERIC Educational Resources Information Center

Prud'homme-Généreux, Annie

2017-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. The author shares the strategies and tools that teachers can use to manage a case study classroom effectively.

Preservice Music Teacher Perceptions of Mentoring Young Composers: An Exploratory Case Study

ERIC Educational Resources Information Center

Menard, Elizabeth A.; Rosen, Robert

2016-01-01

Case study techniques were used to investigate perceptions of undergraduate music majors participating as teacher/mentors for elementary students in a university sponsored music composition program. Data included teacher interviews and observation of teacher training and composition mentoring sessions. Teacher perceptions were categorized as…

Study design options in evaluating gene-environment interactions: practical considerations for a planned case-control study of pediatric leukemia.

PubMed

Goodman, Michael; Dana Flanders, W

2007-04-01

We compare methodological approaches for evaluating gene-environment interaction using a planned study of pediatric leukemia as a practical example. We considered three design options: a full case-control study (Option I), a case-only study (Option II), and a partial case-control study (Option III), in which information on controls is limited to environmental exposure only. For each design option we determined its ability to measure the main effects of environmental factor E and genetic factor G, and the interaction between E and G. Using the leukemia study example, we calculated sample sizes required to detect and odds ratio (OR) of 2.0 for E alone, an OR of 10 for G alone and an interaction G x E of 3. Option I allows measuring both main effects and interaction, but requires a total sample size of 1,500 cases and 1,500 controls. Option II allows measuring only interaction, but requires just 121 cases. Option III allows calculating the main effect of E, and interaction, but not the main effect of G, and requires a total of 156 cases and 133 controls. In this case, the partial case-control study (Option III) appears to be more efficient with respect to its ability to answer the research questions for the amount of resources required. The design options considered in this example are not limited to observational epidemiology and may be applicable in studies of pharmacogenomics, survivorship, and other areas of pediatric ALL research.

A Tale of 2 Teachers: A Preschool Physical Activity Intervention Case Study.

PubMed

Howie, Erin K; Brewer, Alisa E; Dowda, Marsha; McIver, Kerry L; Saunders, Ruth P; Pate, Russell R

2016-01-01

Preschool settings vary greatly, and research has shown that interventions are more successful when they can be adapted to individual settings. This is a descriptive case study of how 2 teachers successfully adapted and implemented a preschool physical activity intervention. The Study of Health and Activity in Preschool Environments (SHAPES) was a 3-year physical activity intervention. A detailed case study of 2 high-implementing teachers was conducted. Multiple data sources included accelerometry, direct observation, teacher surveys, and intervention staff field notes. Teacher A focused on integrating physical activity into a wide range of activities, including parent and community events. Teacher B focused on high-intensity, structured activities. Both teachers supported the intervention, worked closely with intervention staff, and operated their classroom as an autonomous unit with support from their directors. Teacher A provided an average of 31.5, 78.0, and 67.5 min of physical activity opportunity per day of observation during years 1, 2, and 3. Teacher B provided an average of 2.7, 33.5, and 73.3 minutes of physical activity opportunity per day of observation. Successful implementation of physical activity interventions may look different in different contexts; thus, interventions should allow for flexible implementation. © 2015, American School Health Association.

A Tale of Two Teachers: A Preschool Physical Activity Intervention Case Study

PubMed Central

Howie, Erin K.; Brewer, Alisa E.; Dowda, Marsha; McIver, Kerry L.; Saunders, Ruth P.; Pate, Russell R.

2016-01-01

BACKGROUND Preschool settings vary greatly, and research has shown that interventions are more successful when they can be adapted to individual settings. This is a descriptive case study of how two teachers successfully adapted and implemented a preschool physical activity intervention. METHODS The Study of Health and Activity in Preschool Environments (SHAPES) was a three-year physical activity intervention. A detailed case study of two high-implementing teachers was conducted. Multiple data sources included accelerometry, direct observation, teacher surveys and intervention staff field notes. RESULTS Teacher A focused on integrating physical activity into a wide range of activities, including parent and community events. Teacher B focused on high-intensity, structured activities. Both teachers supported the intervention, worked closely with intervention staff, and operated their classroom as an autonomous unit with support from their directors. Teacher A provided an average of 31.5, 78.0 and 67.5 minutes of physical activity opportunity per day of observation during Years 1, 2, and 3. Teacher B provided an average of 2.7, 33.5, and 73.3 minutes of physical activity opportunity per day of observation. CONCLUSION Successful implementation of physical activity interventions may look different in different contexts; thus, interventions should allow for flexible implementation. PMID:26645417

An Arizona Border Wall Case Study

DTIC Science & Technology

2017-12-01

WALL CASE STUDY by Justin Alexander Bristow December 2017 Thesis Advisor: Erik Dahl Second Reader: Jorge Gonzalez THIS PAGE...4. TITLE AND SUBTITLE AN ARIZONA BORDER WALL CASE STUDY 5. FUNDING NUMBERS 6. AUTHOR(S) Justin Alexander Bristow 7. PERFORMING ORGANIZATION...PAGE INTENTIONALLY LEFT BLANK iii Approved for public release. Distribution is unlimited. AN ARIZONA BORDER WALL CASE STUDY Justin Alexander

Design and implementation of observational studies to measure disease burden with a focus on stroke.

PubMed

Howard, George; Howard, Virginia J

2018-02-01

Observational epidemiological studies have the dual goals of measuring disease burden and assessing the association between exposures and outcomes. This report focuses on the first of these goals and provides an overview of design considerations of commonly used approaches, specifically community surveillance studies, cross-sectional studies, and longitudinal cohort studies. Each of these designs has strengths and weaknesses, with no study design being superior in all cases. Rather, these designs are complementary to achieve a better understanding of the burden of stroke.

Use of Visual and Multimedia Resources in an Undergraduate Classroom: A Case Study

ERIC Educational Resources Information Center

Matusiak, Krystyna K.

2012-01-01

This paper reports the findings of a case study that examined the use of digital information resources in an undergraduate geography class. The study assumed a contextual approach and focused on the use of visual and multimedia resources in specific class contexts. The distribution of resources in the class observed for the study varied and…

Factors Influencing Error Recovery in Collections Databases: A Museum Case Study

ERIC Educational Resources Information Center

Marty, Paul F.

2005-01-01

This article offers an analysis of the process of error recovery as observed in the development and use of collections databases in a university museum. It presents results from a longitudinal case study of the development of collaborative systems and practices designed to reduce the number of errors found in the museum's databases as museum…

Qualitative Case Study Research as Empirical Inquiry

ERIC Educational Resources Information Center

Ellinger, Andrea D.; McWhorter, Rochell

2016-01-01

This article introduces the concept of qualitative case study research as empirical inquiry. It defines and distinguishes what a case study is, the purposes, intentions, and types of case studies. It then describes how to determine if a qualitative case study is the preferred approach for conducting research. It overviews the essential steps in…

Teaching Business Demography Using Case Studies.

PubMed

Swanson, David A; Morrison, Peter A

2010-02-01

Many faculty members consider using case studies but not all end up using them. We provide a brief review of what cases are intended to do and identify three ways in which they can be used. We then use an example to illustrate how we have used the case study method in teaching business demography. Among other benefits, we note that the case studies method not only encourages the acquisition of skills by students, but can be used to promote "deep structure learning," an approach naturally accommodates other features associated with the case studies method-the development of critical thinking skills, the use of real world problems, the emphasis of concepts over mechanics, writing and presentation skills, active cooperative learning and the "worthwhileness" of a course. As noted by others, we understand the limitations of the case study method. However, given its strengths, we believe it has a place in the instructional toolbox for courses in business demography. The fact that courses we teach is a testament to our perceived efficacy of this tool.

Peripheral T cell lymphomas: an immunological study of seven unusual cases.

PubMed

Raziuddin, S; Latif, A B; Arif, S; Ahad, A; Zaidi, A Z

1988-05-01

A multiparameter study of malignant lymph node cells and peripheral blood lymphocytes of seven patients with peripheral T cell lymphoma is presented. The results of monoclonal marker studies showed three cases of helper-suppressor T cell lymphoma (OKT4+, OKT8+), one case of suppressor T cell lymphoma (OKT8+), and three cases of helper T cell lymphoma (OKT4+). Immunophenotypic heterogeneity of neoplastic T cells with expression of pan-T antigens, OKT3+, and OKT11+ (erythrocyte rosetting+) was observed in most patients. Six of the seven cases tested showed Ia and DR antigens. No relationship was detected between patterns of reactivity with T cell reagents and histological types. When tested, the in-vitro malignant T cells of five patients proliferated in response to concanavalin A (Con A), but had poor response to phytohaemagglutinin. The interleukin 2 receptors showed maximum expression on Con A-activated T cells of five patients, and phytohaemagglutinin-activated T cells of one patient. The neoplastic T cells (OKT4+, OKT8+) of one patient studied had suppressor activity for IgG and IgA, and helper activity for IgM synthesis on pokeweed mitogen-induced normal B cell differentiations.

Cultivating cohort studies for observational translational research.

PubMed

Ransohoff, David F

2013-04-01

"Discovery" research about molecular markers for diagnosis, prognosis, or prediction of response to therapy has frequently produced results that were not reproducible in subsequent studies. What are the reasons, and can observational cohorts be cultivated to provide strong and reliable answers to those questions? Experimental Selected examples are used to illustrate: (i) what features of research design provide strength and reliability in observational studies about markers of diagnosis, prognosis, and response to therapy? (ii) How can those design features be cultivated in existing observational cohorts, for example, within randomized controlled clinical trial (RCT), other existing observational research studies, or practice settings like health maintenance organization (HMOs)? Examples include a study of RNA expression profiles of tumor tissue to predict prognosis of breast cancer, a study of serum proteomics profiles to diagnose ovarian cancer, and a study of stool-based DNA assays to screen for colon cancer. Strengths and weaknesses of observational study design features are discussed, along with lessons about how features that help assure strength might be "cultivated" in the future. By considering these examples and others, it may be possible to develop a process of "cultivating cohorts" in ongoing RCTs, observational cohort studies, and practice settings like HMOs that have strong features of study design. Such an effort could produce sources of data and specimens to reliably answer questions about the use of molecular markers in diagnosis, prognosis, and response to therapy.

Evaluation of High Resolution Rapid Refresh-Smoke (HRRR-Smoke) model products for a case study using surface PM2.5 observations

NASA Astrophysics Data System (ADS)

Deanes, L. N.; Ahmadov, R.; McKeen, S. A.; Manross, K.; Grell, G. A.; James, E.

2016-12-01

Wildfires are increasing in number and size in the western United States as climate change contributes to warmer and drier conditions in this region. These fires lead to poor air quality and diminished visibility. The High Resolution Rapid Refresh-Smoke modeling system (HRRR-Smoke) is designed to simulate fire emissions and smoke transport with high resolution. The model is based on the Weather Research and Forecasting model, coupled with chemistry (WRF-Chem) and uses fire detection data from the Visible Infrared and Imaging Radiometer Suite (VIIRS) satellite instrument to simulate wildfire emissions and their plume rise. HRRR-Smoke is used in both real-time applications and case studies. In this study, we evaluate the HRRR-Smoke for August 2015, during one of the worst wildfire seasons on record in the United States, by focusing on wildfires that occurred in the northwestern US. We compare HRRR-Smoke simulations with hourly fine particulate matter (PM2.5) observations from the Air Quality System (https://www.epa.gov/aqs) from multiple air quality monitoring sites in Washington state. PM2.5 data includes measurements from urban, suburban and remote sites in the state. We discuss the model performance in capturing large PM2.5 enhancements detected at surface sites due to wildfires. We present various statistical parameters to demonstrate HRRR-Smoke's performance in simulating surface PM2.5 levels.

Performable Case Studies in Ethics Education.

PubMed

Robeson, Richard; King, Nancy M P

2017-09-12

Bioethics education often includes the study of short stories, novels, plays, and films, because such materials present case examples that can highlight relevant issues and questions especially vividly for a wide range of students. In addition, creative writing is widely used in the education of health professional students and in continuing education settings for health professionals. There are very few academic or professional disciplines that do not use case studies, but the case study in dialogic form has not been standard practice for thousands of years. Dramatic arts casuistry-the creation and performance of short case studies designed specifically to raise bioethics issues for discussion-represents an application of literature and the medical humanities that is both unique and uniquely valuable. This essay describes the development and history of a course that has been successfully taught to medical students and graduate bioethics students, in which the class researches, writes, and performs a case study designed to elicit reflection and discussion about a topic and set of bioethics issues of current interest to both academic and general audiences. The model is also suited to the presentation and discussion of existing case studies, both live and via on-demand audio.

Emotion, Engagement, and Case Studies

ERIC Educational Resources Information Center

Herreid, Clyde Freeman; Terry, David R.; Lemons, Paula; Armstrong, Norris; Brickman, Peggy; Ribbens, Eric

2014-01-01

Three college faculty taught large general biology classes using case studies and personal response systems (clickers). Each instructor taught the same eight cases in two different sections, except the questions within the cases differed. In one section the questions were lower order (LO) factual inquiries, and in the other they were largely…

Case control study of neuroblastoma in west-Germany after the Chernobyl accident.

PubMed

Michaelis, J; Haaf, H G; Zöllner, J; Kaatsch, P; Krummenauer, F; Berthold, F

1996-01-01

To explore possible causes of a 1988 incidence peak of infant neuroblastoma in west German regions which were contaminated with more than 6000 Bq/m2 Cs137 from the Chernobyl accident. The primary working hypothesis was that parents of the diseased children had been contaminated by an excessive intake of locally produced food, especially mushrooms or deer. Case control study with 1:2 (cases:controls) matching. Data were collected from the children's parents by questionnaires and telephone interviews. Nation-wide study (former FRG) based on the German Childhood Cancer Registry. Cases born in 1988 and reported with a neuroblastoma to the registry until March 1992. Population-based healthy controls, matched for age, sex and residence at time of diagnosis. The working hypothesis could not be confirmed by the study, because the parents of cases tended to eat less locally grown food than the parents of controls (RR = 0.63, 95% CI:0.20-1.97). Possible influence factors which previously have been described to be associated with neuroblastoma incidence could not be confirmed by the study. Parental exposure to herbicides and pesticides was associated with the occurrence of neuroblastoma (RR = 4.2, 95% CI:1.4-12.9). Neuroblastoma stage distribution in the contaminated regions was shifted towards lower stages as compared to the less contaminated regions and previous age cohorts. The study does not show additional evidence that the observed increase in neuroblastoma incidence might have been caused by exposure to fallout from the Chernobyl accident. The observed shift towards lower clinical stages may rather indicate increased diagnostic awareness. The association between neuroblastoma and parental exposure with herbicides and pesticides resulted from an extensive exploratory data analysis and needs to be confirmed in further studies.

An Ethnographic Case Study of the Administrative Organization, Processes, and Behavior in a Model Comprehensive High School.

ERIC Educational Resources Information Center

Zimman, Richard N.

Using ethnographic case study methodology (involving open-ended interviews, participant observation, and document analysis) theories of administrative organization, processes, and behavior were tested during a three-week observation of a model comprehensive (experimental) high school. Although the study is limited in its general application, it…

Quality standards for real-world research. Focus on observational database studies of comparative effectiveness.

PubMed

Roche, Nicolas; Reddel, Helen; Martin, Richard; Brusselle, Guy; Papi, Alberto; Thomas, Mike; Postma, Dirjke; Thomas, Vicky; Rand, Cynthia; Chisholm, Alison; Price, David

2014-02-01

Real-world research can use observational or clinical trial designs, in both cases putting emphasis on high external validity, to complement the classical efficacy randomized controlled trials (RCTs) with high internal validity. Real-world research is made necessary by the variety of factors that can play an important a role in modulating effectiveness in real life but are often tightly controlled in RCTs, such as comorbidities and concomitant treatments, adherence, inhalation technique, access to care, strength of doctor-caregiver communication, and socio-economic and other organizational factors. Real-world studies belong to two main categories: pragmatic trials and observational studies, which can be prospective or retrospective. Focusing on comparative database observational studies, the process aimed at ensuring high-quality research can be divided into three parts: preparation of research, analyses and reporting, and discussion of results. Key points include a priori planning of data collection and analyses, identification of appropriate database(s), proper outcomes definition, study registration with commitment to publish, bias minimization through matching and adjustment processes accounting for potential confounders, and sensitivity analyses testing the robustness of results. When these conditions are met, observational database studies can reach a sufficient level of evidence to help create guidelines (i.e., clinical and regulatory decision-making).

Risk of stroke in patients with patent foramen ovale: an updated meta-analysis of observational studies.

PubMed

Ma, Bing; Liu, Guangcong; Chen, Xin; Zhang, Jianming; Liu, Yiting; Shi, Jingpu

2014-01-01

Although patent foramen ovale (PFO) is considered to be associated with cryptogenic stroke (CS), there remains an ongoing disputation on this issue because of unstable results from randomized controlled trials. The aim of this study was to reassess the PFO effect on stroke through observational data. An electronic search of PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) were finished. Only case-control studies and cohort studies in Chinese or English were included in the analysis. Then random-effected meta-analysis models were performed to assess the association between PFO and stroke. Twelve case-control studies and 6 cohort studies were eligible. Case-control studies showed strong association between PFO and CS (odds ratio [OR]: 2.94, 95% confidence interval [CI]: 2.06, 4.20; P < .001), but cohort studies failed to demonstrate a significant association (hazard ratio [HR]: 1.28, 95% CI: .91, 1.80; P = .155). Subgroup analysis revealed that the pooled OR decreased significantly when the region was limited to the United States (OR: 1.52, 95% CI: 1.00, 2.32; P = .083). OR of studies that adjusted major confounders was 1.74 (95% CI: 1.22, 2.47; P = .119) and high-quality studies was 1.68 (95% CI: 1.14, 2.47; P = .072). For cohort studies, a weak statistical association was observed in using transesophageal echocardiography (TEE) studies (HR: 1.45, 95% CI: 1.06, 2.01; P = .138) and follow-up years less than 4 years' studies (HR: 1.45, 95% CI: 1.00, 2.09; P = .064). Although case-control studies still show a positive effect of PFO on stroke, the results of cohort challenged the credibility. Further trial data are needed to confirm the effect of PFO on stroke. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Clinical, Bronchographic, Radiological, and Physiological Observations in Ten Cases of Asbestosis

PubMed Central

Leathart, G. L.

1960-01-01

Ten cases of asbestosis (eight male, two female), aged 45-65 years have been kept under observation for periods of up to eight years. Bronchiectasis was demonstrated bronchographically in six cases. Clubbing of the fingers and coarse crepitations appeared to be signs of bronchiectasis rather than of uncomplicated asbestosis. It is suggested that the prevalence of bronchiectasis is higher than has been reported previously because the patients survived longer. The radiological findings are tabulated and compared with previous descriptions. In these subjects there was no relationship between radiological and clinical state. Nine patients eventually showed clinical deterioration and it often proceeded rapidly. The radiograph however, usually remained unaltered. Pulmonary function tests, including diffusing capacity, arterial blood analysis and estimation of mechanical properties of the lung, were carried out in these 10 cases, and in 11 asbestos workers (aged 35-64 years) without radiological abnormality. The steady state diffusing capacity for carbon monoxide (Dco) at rest was lower in asbestosis than in the control subjects. The pulmonary compliance was remarkably low in asbestosis and related fairly closely to the vital capacity. The maximum voluntary ventilation was also low and was related to increased pulmonary resistance but it cannot be said whether this is in the airways or in the lung tissue. Indirect evidence of inequalities of ventilation/perfusion ratio was obtained in most cases. There is no convincing evidence that pulmonary fibrosis occurs without radiological abnormality, but a defect of diffusion may occur. There is no test of pulmonary function which is diagnostic, but a low pulmonary compliance, especially if combined with a low diffusing capacity, is confirmatory. It is suggested that the demonstration of a progressive decline in vital capacity, or in diffusing capacity, may enable a diagnosis of asbestosis to be made before radiological

Transportation planning effectiveness: twenty case studies

DOT National Transportation Integrated Search

1977-12-31

This document consists of 20 site-specific case studies of urban area experience with the Technical Study Grant Program of the Urban Mass Transportation Administration (UMTA). The objective of the case studies is to determine how the Technical Study ...

Library-ABE Projects. Case Studies.

ERIC Educational Resources Information Center

MacVicar, Phyllis

This document contains 41 case studies submitted to the Appalachian Adult Education Center by the staffs of four projects demonstrating library services to disadvantaged adults, in cooperation with adult basic education programs. Included in each case study is the coping skill area in which an individual need was recognized and met through the…

Teaching Business French through Case Studies: Presentation of a Marketing Case.

ERIC Educational Resources Information Center

Federico, Salvatore; Moore, Catherine

The use of case studies as a means for teaching business French is discussed. The approach is advocated because of the realism of case studies, which are based on actual occurrences. Characteristics of a good case are noted: it tells a story, focuses on interest-arousing issues, is set in the past 10 years, permits empathy with the main…

Case Study: Puttin' on the Ritz: How to Put Science into Cases

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2017-01-01

There are multiple ways to put science into a case. This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses different ways of presenting science in case studies.

The "Reverse Case Study:" Enhancing Creativity in Case-Based Instruction in Leadership Studies

ERIC Educational Resources Information Center

Atkinson, Timothy N.

2014-01-01

In this application brief I share a case study assignment I used in my "Leadership in Complex Organizations" classes to promote creativity in problem solving. I sorted Ph.D. students into two teams and trained them to use creative writing techniques to "encode" theory into their own cases. A sense of competition emerged. Later,…

Emotions and Values--A Case Study of Meaning-Making in ESE

ERIC Educational Resources Information Center

Manni, Annika; Sporre, Karin; Ottander, Christina

2017-01-01

With an interest in the role of emotions and values in students' meaning-making in Environmental and Sustainability Education a case study was carried out in a Swedish school-class with students, 12 years of age. During a six-week thematic group-work focusing environmental and sustainability issues related to food, the students were observed and…

Beyond Clinical Case Studies in Psychoanalysis: A Review of Psychoanalytic Empirical Single Case Studies Published in ISI-Ranked Journals.

PubMed

Meganck, Reitske; Inslegers, Ruth; Krivzov, Juri; Notaerts, Liza

2017-01-01

Single case studies are at the origin of both theory development and research in the field of psychoanalysis and psychotherapy. While clinical case studies are the hallmark of psychoanalytic theory and practice, their scientific value has been strongly criticized. To address problems with the subjective bias of retrospective therapist reports and uncontrollability of clinical case studies, systematic approaches to investigate psychotherapy process and outcome at the level of the single case have been developed. Such empirical case studies are also able to bridge the famous gap between academic research and clinical practice as they provide clinically relevant insights into how psychotherapy works. This study presents a review of psychoanalytic empirical case studies published in ISI-ranked journals and maps the characteristics of the study, therapist, patient en therapies that are investigated. Empirical case studies increased in quantity and quality (amount of information and systematization) over time. While future studies could pay more attention to providing contextual information on therapist characteristics and informed consent considerations, the available literature provides a basis to conduct meta-studies of single cases and as such contribute to knowledge aggregation.

Beyond Clinical Case Studies in Psychoanalysis: A Review of Psychoanalytic Empirical Single Case Studies Published in ISI-Ranked Journals

PubMed Central

Meganck, Reitske; Inslegers, Ruth; Krivzov, Juri; Notaerts, Liza

2017-01-01

Single case studies are at the origin of both theory development and research in the field of psychoanalysis and psychotherapy. While clinical case studies are the hallmark of psychoanalytic theory and practice, their scientific value has been strongly criticized. To address problems with the subjective bias of retrospective therapist reports and uncontrollability of clinical case studies, systematic approaches to investigate psychotherapy process and outcome at the level of the single case have been developed. Such empirical case studies are also able to bridge the famous gap between academic research and clinical practice as they provide clinically relevant insights into how psychotherapy works. This study presents a review of psychoanalytic empirical case studies published in ISI-ranked journals and maps the characteristics of the study, therapist, patient en therapies that are investigated. Empirical case studies increased in quantity and quality (amount of information and systematization) over time. While future studies could pay more attention to providing contextual information on therapist characteristics and informed consent considerations, the available literature provides a basis to conduct meta-studies of single cases and as such contribute to knowledge aggregation. PMID:29046660

Atlanta NAVIGATOR case study. Final report, May 1996--Jun 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amodei, R.; Bard, E.; Brong, B.

1998-11-01

The Atlanta metropolitan region was the location of one of the most ambitious Intelligent Transportation Systems (ITS) deployments in the United States. This deployment included several individual projects--a Central Transportation Management Center (TMC), six Traffic Control Centers (TCC), one Transit Information Center (TIC), the Travel Information Showcase (TIS), and the extension of the Metropolitan Atlanta Rapid Transit Authority (MARTA) rail network and the new high-occupancy vehicle (HOV) lanes on I-85 and I-75. The Atlanta Centennial Olympic Games and Paralympic Games created a focus for these projects. All of these systems were to be brought on line in time for themore » Olympic Games. This report presents the findings of the NAVIGATOR Case Study and documents the lessons learned from the Atlanta ITS deployment experience in order to improve other ITS deployments in the future. The Case Study focuses on the institutional, programmatic, and technical issues and opportunities from planning and implementing the ITS deployment in Atlanta. The Case Study collected data and information from interviews, observations, focus groups, and documentation reviews. It presents a series of lessons learned and recommendations for enabling successful ITS deployments nationwide.« less

Influence function based variance estimation and missing data issues in case-cohort studies.

PubMed

Mark, S D; Katki, H

2001-12-01

Recognizing that the efficiency in relative risk estimation for the Cox proportional hazards model is largely constrained by the total number of cases, Prentice (1986) proposed the case-cohort design in which covariates are measured on all cases and on a random sample of the cohort. Subsequent to Prentice, other methods of estimation and sampling have been proposed for these designs. We formalize an approach to variance estimation suggested by Barlow (1994), and derive a robust variance estimator based on the influence function. We consider the applicability of the variance estimator to all the proposed case-cohort estimators, and derive the influence function when known sampling probabilities in the estimators are replaced by observed sampling fractions. We discuss the modifications required when cases are missing covariate information. The missingness may occur by chance, and be completely at random; or may occur as part of the sampling design, and depend upon other observed covariates. We provide an adaptation of S-plus code that allows estimating influence function variances in the presence of such missing covariates. Using examples from our current case-cohort studies on esophageal and gastric cancer, we illustrate how our results our useful in solving design and analytic issues that arise in practice.

Ionospheric scintillation detection based on GPS observations, a case study over Iran

NASA Astrophysics Data System (ADS)

Sobhkhiz Miandehi, Sahar; Alizadeh Elizei, M. Mahdi; Schuh, Harald

2017-04-01

Global Positioning System (GPS) which is used extensively for various purposes such as navigation, surveying, remote sensing and telecommunication, is strongly affected by the earth's upper atmosphere, the ionosphere. Ionosphere is a highly variable region with complex physical characteristics in which the density of free electrons are large enough to have considerable effects on signals' propagation travelling through this dispersive medium. As GPS signals travel through the ionosphere, they may experience rapid amplitude fluctuations or unexpected phase changes. This is referred to as ionospheric scintillation. Ionospheric scintillation which is caused by small scale irregularities in the electron density, is one of the dominant propagation disturbances at radio frequency signals. These irregularities severely affect the accuracy and reliability of GPS measurements. Therefore it is necessary to investigate ionospheric scintillation and its effects on GPS observations. The focus of this paper is to detect ionospheric scintillations over Iran's region, during different periods of solar activity and to investigate these effects on GPS observations in more detail. Furthermore the effects of these irregularities on regional modeling of ionosphere over Iran is also investigated. The results show that effectiveness of this phenomenon depends on geographic location, local time and global geomagnetic storm index (kp index). The required data for this investigation are ground based measurements of permanent GPS stations over Iran, established by the National Cartographic Center of Iran (NCC).

[Child abuse in Tlaxcala: a case-control study].

PubMed

Herrada-Huidobro, A; Nazar-Beutelspacher, A; Cassaball-Núñez, M; Vega-Ramos, R; Nava-Cruz, C B

1992-01-01

A longitudinal, retrospective and descriptive study about child abuse was carried out in the Hospitals of the Tlaxcala Secretariat of Health, Mexico. The information was obtained from hospitalized children's charts between January first and November 30, 1991. The charts included were those belonging to zero to 14 year old children with injuries, poisoning, and II-III degrees of malnutrition. Four child-abuse criteria were established: physical, sexual, non organic malnutrition and mixed (physical and non organic malnutrition). Two control groups were defined. Different patterns were observed between accidental and non accidental injuries, malnutrition and poisoning among the case and the control groups. The study provides useful information for the integral diagnosis of child abuse in hospitalized children.

The Nature of Integration among PCK Components: A Case Study of Two Experienced Chemistry Teachers

ERIC Educational Resources Information Center

Aydin, Sevgi; Boz, Yezdan

2013-01-01

In this qualitative case study, we examined the nature of integration among pedagogical content knowledge (PCK) components. To attain the goal, two experienced chemistry teachers' teaching redox reactions and electrochemical cells was observed. The data were collected through card-sorting activity, content representation (CoRe) tool, observation,…

Case study of Bell's palsy applying complementary treatment within an occupational therapy model.

PubMed

Haltiwanger, Emily; Huber, Theresa; Chang, Joe C; Gonzalez-Stuart, Armando; Gonzales-Stuart, Armando

2009-01-01

For 7% of people with Bell's palsy, facial impairment is permanent. The case study patient was a 48-year-old female who had no recovery from paralysis 12 weeks after onset. Goals were to restore facial sensory-motor functions, functional abilities and reduce depression. Facial paralysis was assessed by clinical observations, the Facial Disability Index and Beck Depression Index. Complementary interventions of aromatherapy, reflexology and electro-acupuncture were used with common physical agent modalities in an intensive home activity and exercise programme. The patient had 100% return of function and resolution of depression after 10 days of intervention. The limitation of this study is that it was a retrospective case study and the investigators reconstructed the case from clinical notes. Further research using a prospective approach is recommended to replicate this study. 2009 John Wiley & Sons, Ltd

Clinical observation in 86 cases of acne vulgaris treated with Compound Oldenlandis Mixture.

PubMed

Liu, Wali; Shen, Dong; Song, Ping; Xu, Xian

2003-12-01

86 cases of acne vulgaris were treated with Fu Fang She She Cao He Ji ([symbol: see text] Compound Oldenlandis Mixture), with the other 34 cases treated with Dang Gui Ku Shen Wan ([symbol: see text] Pills Prepared from Chinese Angelica and Flavescent Sophora Root) as the controls, to observe the therapeutic effect of the former. The results showed that the cure plus markedly effective rate was 73.26% in the treatment group, and 47.06% in the control group, with a significant difference in the cure plus markedly effective rate between the two groups (P < 0.01), and also in the total effective rate between the two groups significant (P < 0.05). It may be concluded that the Compound Oldenlandis Mixture is a better agent for the illness.

[Survival after cutaneous metastasis: a study of 200 cases].

PubMed

Schoenlaub, P; Sarraux, A; Grosshans, E; Heid, E; Cribier, B

2001-12-01

cases), colo-rectal cancer: 4.4 months (9 cases), pancreatic cancer: 3.3 months (2 cases), stomach cancer: 1.2 months (7 cases) and liver and gall bladder carcinoma: < 1 month (3 cases). Survival beyond 10 years was observed in 9 patients: 3 melanoma, 2 breast cancers, 2 prostatic carcinomas, 1 larynx carcinoma and 1 cutaneous squamous cell carcinoma. This is the first study in which the survival after the occurrence of skin metastasis was systematically analysed in a large series of patients. It shows that half of patients with cutaneous metastasis die within the first 6 months after the diagnosis. Those cases due to lung carcinoma have the poorest prognosis.

The challenges to gender integration in the career fire services: a comparative case study of men in nursing

DTIC Science & Technology

2017-03-01

GENDER INTEGRATION IN THE CAREER FIRE SERVICES: A COMPARATIVE CASE STUDY OF MEN IN NURSING by Anna L. Schermerhorn-Collins March 2017...IN THE CAREER FIRE SERVICES: A COMPARATIVE CASE STUDY OF MEN IN NURSING 5. FUNDING NUMBERS 6. AUTHOR(S) Anna L. Schermerhorn-Collins 7... comparative case study of men in nursing. Research is based in academic and historical accounts, in addition to the use of participant-observation

The Alberta smoke plume observation study

NASA Astrophysics Data System (ADS)

Anderson, Kerry; Pankratz, Al; Mooney, Curtis; Fleetham, Kelly

2018-02-01

A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS). Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018) at http://cwfis.cfs.nrcan.gc.ca/datamart.

Situated Teacher Quality: A Case Study of an Experienced Elementary School Teacher

ERIC Educational Resources Information Center

Kolman, Joni S.

2017-01-01

This case study examines how an experienced teacher's practice and pedagogy differs across two high-accountability urban charter schools in the United States of America (USA). Drawing on semi-structured interviews and participant observations, the findings describe variances in Rebecca's planning, use of classroom time, and curriculum flexibility,…

Evaluation of Oral Performance in Outsourced Call Centres: An Exploratory Case Study

ERIC Educational Resources Information Center

Friginal, Eric

2013-01-01

This case study discusses the development and use of an oral performance assessment instrument intended to evaluate Filipino agents' customer service transactions with callers from the United States (US). The design and applications of the instrument were based on a longitudinal, qualitative observation of language training and customer service…

Teaming To Teach English to International High School Students: A Case Study.

ERIC Educational Resources Information Center

Bonissone, Paola R.

A case study focused on teachers' professional networks and how these influence the students' acquisition of literacy skills, particularly writing, at the International High School in New York City, which serves approximately 450 international students with minimal language skills. Observations were taken from three teachers as well as from…

Inclusive Education in an International School: A Case Study from Hong Kong

ERIC Educational Resources Information Center

Chan, Twiggy; Yuen, Mantak

2015-01-01

This case study provides an overview of current policy, practices and problems concerning inclusion in one international secondary school in Hong Kong. A total of 13 interviews were conducted with the school management team, teachers, students and parents, supplemented by 12 classroom observations and two "student-shadowing" exercises.…

Case Studies for Effective Business Instruction.

ERIC Educational Resources Information Center

McAlister-Kizzier, Donna

This book is designed as a resource for educators who teach business content in a variety of instructional settings. It contains case studies representing all functional areas of business, including corporate training, for grades 7 through graduate education. Chapter 1 provides an overview of the case study method. The history of the case method,…

Case management: a case study.

PubMed

Stanton, M P; Walizer, E M; Graham, J I; Keppel, L

2000-01-01

This article describes the implementation of a pilot case management program at Walter Reed Army Medical Center. I, it we discuss obvious pitfalls and problems implementing case management in a large multiservice center and the steps and processes implemented to expedite and move case management forward in its early stages. The insights shared may be useful for those implementing case management in a complex medical center situation. Other models used in similar situations are also reviewed.

HYDROGEOLOGIC CASE STUDIES

EPA Science Inventory

Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

The Big Read: Case Studies

ERIC Educational Resources Information Center

National Endowment for the Arts, 2009

2009-01-01

The Big Read evaluation included a series of 35 case studies designed to gather more in-depth information on the program's implementation and impact. The case studies gave readers a valuable first-hand look at The Big Read in context. Both formal and informal interviews, focus groups, attendance at a wide range of events--all showed how…

Performable Case Studies in Ethics Education

PubMed Central

Robeson, Richard; King, Nancy M. P.

2017-01-01

Bioethics education often includes the study of short stories, novels, plays, and films, because such materials present case examples that can highlight relevant issues and questions especially vividly for a wide range of students. In addition, creative writing is widely used in the education of health professional students and in continuing education settings for health professionals. There are very few academic or professional disciplines that do not use case studies, but the case study in dialogic form has not been standard practice for thousands of years. Dramatic arts casuistry—the creation and performance of short case studies designed specifically to raise bioethics issues for discussion—represents an application of literature and the medical humanities that is both unique and uniquely valuable. This essay describes the development and history of a course that has been successfully taught to medical students and graduate bioethics students, in which the class researches, writes, and performs a case study designed to elicit reflection and discussion about a topic and set of bioethics issues of current interest to both academic and general audiences. The model is also suited to the presentation and discussion of existing case studies, both live and via on-demand audio. PMID:28895903

Self-socialization: a case study of a parachute child.

PubMed

Newman, Philip R; Newman, Barbara M

2009-01-01

The theoretical concept of self-socialization suggests that an individual is able to reflect on the self, formulate a vision of a future self, set goals, and take actions that create or alter the developmental trajectory. This case study of a parachute child illustrates how a person constructs her life from a very young age, drawing on a profound capacity for personal agency to overcome obstacles, identify resources, and internalize values to build a life structure. A model of the psychosocial process of self-socialization emerges from this case. Following the disruption of a well-defined trajectory, self-socialization is observed as a sequence of actions, reflection, correction, and new actions. Self-socialization is possible when a strong sense of self-efficacy is applied to attaining internalized values and goals.

[Quality analysis of observational studies on pelvic organ prolapse in China].

PubMed

Wang, Y T; Tao, L Y; He, H J; Han, J S

2017-06-25

Objective: To evaluate the quality of observational studies on pelvic organ prolapse in China. Methods: The checklist of strengthening the reporting of observational studies in epidemiology (STROBE) statement was applied to evaluate the observational studies. The articles were searched in the SinoMed database using the terms: prolapse, uterine prolapse, cystocele, rectal prolapse and pelvic floor; limited to Chinese core journals in obstetrics and gynecology from January 1996 to December 2015. With two 10-year groups (1996-2005 and 2006-2015), the χ(2) test was used to evaluate inter-group differences. Results: (1) A total of 386 observational studies were selected, including 15.5%(60/386) of case-control studies, 80.6%(311/386) of cohort studies and 3.9% (15/386) of cross-sectional studies. (2) There were totally 22 items including 34 sub-items in the checklist. There were 17 sub-items (50.0%, 17/34) had a reporting ratio less than 50% in all of aticles, including: 1a (study's design) 3.9% (15/386), 6a (participants) 24.6% (95/386), 6b (matched studies) 0 (0/386), 9 (bias) 8.3% (32/386), 10 (study size) 3.9%, 11 (quantitative variables) 41.2% (159/386), 12b-12e (statistical methods in detail) 0-2.6% (10/386), 13a (numbers of individuals at each stage of study) 18.9% (73/386), 13b (reasons for non-participation at each stage) 18.9%, 13c (flow diagram) 0, 16b and 16c (results of category boundaries and relative risk) 9.6% (37/386) and 0, 19 (limitations) 31.6% (122/386), 22 (funding) 20.5% (79/386). (3) The quality of articles published in the two decades (1996-2005 and 2006-2015) were compared, and 38.2%(13/34) of sub-items had been significantly improved in the second 10-year (all P< 0.05). The improved items were as follows: 1b (integrity of abstract), 2 (background/rationale), 6a (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 11 (quantitative variables), 12a (statistical methods), 17 (other analyses), 18 (key results), 19 (limitations

Coal rib response during bench mining: A case study

PubMed Central

Sears, Morgan M.; Rusnak, John; Van Dyke, Mark; Rashed, Gamal; Mohamed, Khaled; Sloan, Michael

2018-01-01

In 2016, room-and-pillar mining provided nearly 40% of underground coal production in the United States. Over the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in U.S. underground coal mines. Nine of these 12 fatalities (75%) have occurred in room-and-pillar mines. The objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 m. This paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated numerical model of the observed rib response, and application of this calibrated model to a second site. PMID:29862125

Association between bullous pemphigoid and neurologic diseases: a case-control study.

PubMed

Casas-de-la-Asunción, E; Ruano-Ruiz, J; Rodríguez-Martín, A M; Vélez García-Nieto, A; Moreno-Giménez, J C

2014-11-01

In the past 10 years, bullous pemphigoid has been associated with other comorbidities and neurologic and psychiatric conditions in particular. Case series, small case-control studies, and large population-based studies in different Asian populations, mainland Europe, and the United Kingdom have confirmed this association. However, no data are available for the Spanish population. This was an observational, retrospective, case-control study with 1:2 matching. Fifty-four patients with bullous pemphigoid were selected. We compared the percentage of patients in each group with concurrent neurologic conditions, ischemic heart disease, diabetes, chronic obstructive pulmonary disease, and solid tumors using univariate logistic regression. An association model was constructed with conditional multiple logistic regression. The case group had a significantly higher percentage of patients with cerebrovascular accident and/or transient ischemic attack (odds ratio [OR], 3.06; 95% CI, 1.19-7.87], dementia (OR, 5.52; 95% CI, 2.19-13.93), and Parkinson disease (OR, 5; 95% CI, 1.57-15.94). A significantly higher percentage of cases had neurologic conditions (OR, 6.34; 95% CI, 2.89-13.91). Dementia and Parkinson disease were independently associated with bullous pemphigoid in the multivariate analysis. Patients with bullous pemphigoid have a higher frequency of neurologic conditions. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

Evaluation of Cirrus Cloud Simulations Using ARM Data - Development of a Case Study Data Set

NASA Technical Reports Server (NTRS)

O'C.Starr, David; Demoz, Belay; Lare, Andrew; Poellot, Michael; Sassen, Kenneth; Heymsfield, Andrew; Brown, Philip; Mace, Jay; Einaudi, Franco (Technical Monitor)

2001-01-01

Cloud-resolving models (CRMs) provide an effective linkage in terms of parameters and scales between observations and the parametric treatments of clouds in global climate models (GCMs). They also represent the best understanding of the physical processes acting to determine cloud system lifecycle. The goal of this project is to improve state-of-the-art CRMs used for studies of cirrus clouds and to establish a relative calibration with GCMs through comparisons among CRMs, single column model (SCM) versions of the GCMs, and observations. This project will compare and evaluate a variety of CRMs and SCMs, under the auspices of the GEWEX Cloud Systems Study (GCSS) Working Group on Cirrus Cloud Systems (WG2), using ARM data acquired at the Southern Great Plains (SGP) site. This poster will report on progress in developing a suitable WG2 case study data set based on the September 26, 1996 ARM IOP case - the Hurricane Nora outflow case. The environmental data (input) will be described as well as the wealth of validating cloud observations. We plan to also show results of preliminary simulations. The science questions to be addressed derive significantly from results of the GCSS WG2 cloud model comparison projects, which will be briefly summarized.

Paradox of Student Gender: A Case Study of Economic Education from China

ERIC Educational Resources Information Center

Zhang, Jian; Qiao, Fangbin; Li, Binbin

2016-01-01

In many Chinese universities and colleges, female students outperform male students in social science subjects. This paper presents a case study, which examines gender difference in economic education in a Chinese university. We look at a sample of students from the Chinese university and find that holding constant observed student…

Online Learning and Teaching with Technology: Case Studies, Experience and Practice. Case Studies of Teaching in Higher Education.

ERIC Educational Resources Information Center

Murphy, David, Ed.; Walker, Rob, Ed.; Webb, Graham, Ed.

This book contains case studies that look at using technology in a wide range of situations, from fully online courses to more traditional face-to-face settings. The case studies deal with issues related to student interaction, teaching and assessment, planning and development, and policy. The following case studies are included: (1) "Flame…

Exploring Pre-Operational and Concrete Operational Children's Thinking on Nutrition: A Case Study

ERIC Educational Resources Information Center

Brouse, Corey H.; Chow, Tracy H. F.

2009-01-01

Objective: In this exploratory study, we observed the process in which children make food choices from a cognitive development perspective and the implications that these choices have on the areas of cognitive development and health and nutrition education. Design: This was a cross-sectional case study that involved an in-depth examination of the…

ARCADO - Adding random case analysis to direct observation in workplace-based formative assessment of general practice registrars.

PubMed

Ingham, Gerard; Fry, Jennifer; Morgan, Simon; Ward, Bernadette

2015-12-10

Workplace-based formative assessments using consultation observation are currently conducted during the Australian general practice training program. Assessment reliability is improved by using multiple assessment methods. The aim of this study was to explore experiences of general practice medical educator assessors and registrars (trainees) when adding random case analysis to direct observation (ARCADO) during formative workplace-based assessments. A sample of general practice medical educators and matched registrars were recruited. Following the ARCADO workplace assessment, semi-structured qualitative interviews were conducted. The data was analysed thematically. Ten registrars and eight medical educators participated. Four major themes emerged - formative versus summative assessment; strengths (acceptability, flexibility, time efficiency, complementarity and authenticity); weaknesses (reduced observation and integrity risks); and contextual factors (variation in assessment content, assessment timing, registrar-medical educator relationship, medical educator's approach and registrar ability). ARCADO is a well-accepted workplace-based formative assessment perceived by registrars and assessors to be valid and flexible. The use of ARCADO enabled complementary insights that would not have been achieved with direct observation alone. Whilst there are some contextual factors to be considered in its implementation, ARCADO appears to have utility as formative assessment and, subject to further evaluation, high-stakes assessment.

No Need to Wait for Superman: A Case Study of One Unique High School

ERIC Educational Resources Information Center

Ratcliff, N. J.; Jones, C. R.; Costner, R. H.; Knight, C.; Disney, G.; Savage-Davis, E.; Sheehan, H.; Hunt, G. H.

2012-01-01

Based on a theoretical model developed by Schlechty, this case study focuses on a small high school, located on a college campus and designed to address the educational needs of gifted 9th- through 12th-grade students. Eight teachers who taught 9th- and 12th-grade classes and their 60 students were observed. Each teacher was observed during six…

[Fulminant Wilson's disease in Costa Rica. Clinico-pathological study of 7 cases].

PubMed

Herra, S A; Hevia, F J; Vargas, M; Schosinsky, K

1990-01-01

In the last eighteen years, from 1972 to 1989, around 150 cases of Wilson's disease have been diagnosed in Costa Rica (6/100.000 inhabitants). In the San Juan de Dios Hospital, 120 cases have been studied during this period, seven of whom died with a picture of acute hepatic insufficiency, hemolytic anemia, encephalopathy, intestinal bleeding and renal insufficiency. In four of the cases, postmortem histopathologic studies were done with high resolution microscopy, which revealed extensive submassive necrosis of the liver, with severe cholestatic, lytic and acidophilic necrosis with nodular, irregular regeneration and specially microvacuolar steatosis, different from that observed in other forms of fulminant hepatitis. With the clinical, laboratory and histopathologic findings, we concluded that fulminant Wilson's disease is a well-defined pathological clinical entity of fatal evolution with no response to therapy, including early treatment with penicillamine and steroids.

A bias-adjusted evidence synthesis of RCT and observational data: the case of total hip replacement.

PubMed

Schnell-Inderst, Petra; Iglesias, Cynthia P; Arvandi, Marjan; Ciani, Oriana; Matteucci Gothe, Raffaella; Peters, Jaime; Blom, Ashley W; Taylor, Rod S; Siebert, Uwe

2017-02-01

Evaluation of clinical effectiveness of medical devices differs in some aspects from the evaluation of pharmaceuticals. One of the main challenges identified is lack of robust evidence and a will to make use of experimental and observational studies (OSs) in quantitative evidence synthesis accounting for internal and external biases. Using a case study of total hip replacement to compare the risk of revision of cemented and uncemented implant fixation modalities, we pooled treatment effect estimates from OS and RCTs, and simplified existing methods for bias-adjusted evidence synthesis to enhance practical application. We performed an elicitation exercise using methodological and clinical experts to determine the strength of beliefs about the magnitude of internal and external bias affecting estimates of treatment effect. We incorporated the bias-adjusted treatment effects into a generalized evidence synthesis, calculating both frequentist and Bayesian statistical models. We estimated relative risks as summary effect estimates with 95% confidence/credibility intervals to capture uncertainty. When we compared alternative approaches to synthesizing evidence, we found that the pooled effect size strongly depended on the inclusion of observational data as well as on the use bias-adjusted estimates. We demonstrated the feasibility of using observational studies in meta-analyses to complement RCTs and incorporate evidence from a wider spectrum of clinically relevant studies and healthcare settings. To ensure internal validity, OS data require sufficient correction for confounding and selection bias, either through study design and primary analysis, or by applying post-hoc bias adjustments to the results. © 2017 The Authors. Health Economics published by John Wiley & Sons, Ltd. © 2017 The Authors. Health Economics published by John Wiley & Sons, Ltd.

Organizing pneumonia and occupational and environmental risk factors: a case-control study.

PubMed

Jobard, Stéphanie; Chaigne, Benjamin; Marchand-Adam, Sylvain; Lasfargues, Gérard; Diot, Elisabeth

2017-11-01

A single-center case-control study was carried out to investigate the relationship between occupational and environmental exposure and organizing pneumonia (OP). Thirty-seven cases of OP, including 25 cases of cryptogenic OP, and 111 controls were included. Occupational exposure was assessed retrospectively by an industrial hygienist and an occupational physician, through semi-quantitative estimates of exposure. An exposure score was calculated for each subject, based on probability, intensity, daily frequency, and duration of exposure for each period of employment. The final cumulative exposure score was obtained by summing exposure scores for all periods of employment. Significant associations with all-cause OP were observed for exposure to tetrachloroethylene (OR 13.33, CI 95% 1.44-123.5) and silica (OR 6.61, CI 95% 1.16-37.71). A significant association with cryptogenic OP was observed only for tetrachloroethylene (OR 31.6, CI 95% 1.64-610.8). No associations were found for environmental exposure. Despite its low statistical power, this work suggests that occupational risk factors could be involved in OP.

An Observational Study of the Relationship between Diagnosis and Remediation in Reading. Research Series No. 72.

ERIC Educational Resources Information Center

Weinshank, Annette B.

A study was conducted to determine whether reading specialists' diagnoses lead directly to remedial recommendations. Eight experienced reading specialists were observed during 24 sessions as they performed a series of tasks using three simulated cases of reading difficulty, two of which were thinly disguised versions of the same reading problem.…

In Case You Teach English: Case Studies in the English Classroom.

ERIC Educational Resources Information Center

Johannessen, Larry R.

Case studies can be a powerful strategy to use for helping students learn critical thinking processes that are key to interpreting and responding to literature and writing. Some of the major benefits of applying case methods are: cases provide an environment for active learning; they encourage the creation of a community of learners; cases help…

Case Study: Let's Get Personal--Putting Personality into Your Cases

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2017-01-01

In this case study, the subject for discussion is the need to use teaching notes in order to add personality to case studies. Personality, it is said, is more important than policy, than demographics, than finances, or amorous peccadillos. Personality is essential. It is the interaction of people that capture our interest, yet, the question is…

Effect of temperature and precipitation on salmonellosis cases in South-East Queensland, Australia: an observational study.

PubMed

Stephen, Dimity Maree; Barnett, Adrian Gerard

2016-02-25

Foodborne illnesses in Australia, including salmonellosis, are estimated to cost over $A1.25 billion annually. The weather has been identified as being influential on salmonellosis incidence, as cases increase during summer, however time series modelling of salmonellosis is challenging because outbreaks cause strong autocorrelation. This study assesses whether switching models is an improved method of estimating weather-salmonellosis associations. We analysed weather and salmonellosis in South-East Queensland between 2004 and 2013 using 2 common regression models and a switching model, each with 21-day lags for temperature and precipitation. The switching model best fit the data, as judged by its substantial improvement in deviance information criterion over the regression models, less autocorrelated residuals and control of seasonality. The switching model estimated a 5 °C increase in mean temperature and 10 mm precipitation were associated with increases in salmonellosis cases of 45.4% (95% CrI 40.4%, 50.5%) and 24.1% (95% CrI 17.0%, 31.6%), respectively. Switching models improve on traditional time series models in quantifying weather-salmonellosis associations. A better understanding of how temperature and precipitation influence salmonellosis may identify where interventions can be made to lower the health and economic costs of salmonellosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Colorectal cancer risk and dietary intake of calcium, vitamin D, and dairy products: a meta-analysis of 26,335 cases from 60 observational studies.

PubMed

Huncharek, Michael; Muscat, Joshua; Kupelnick, Bruce

2009-01-01

In vivo and in vitro studies suggest that dairy products, calcium, and dietary vitamin D inhibits the development of colorectal cancer (CRC). A meta-analysis was performed to evaluate this relationship in observational studies. Data from 60 epidemiological studies enrolling 26,335 CRC cases were pooled using a general variance-based meta-analytic method. Summary relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated for the highest vs. the lowest intake categories. Sensitivity analyses tested the robustness of these summary effect measures and the statistical heterogeneity. The summary RR for high milk and dairy product intake, respectively, on colon cancer risk was 0.78 (95% CI = 0.67-0.92) and 0.84 (95% CI = 0.75-0.95). Milk intake was unrelated to rectal cancer risk. High calcium intake had a greater protective effect against tumors of the distal colon and rectal cancer vs. proximal colon. The risk reduction associated with calcium was similar for dietary and supplemental sources. Vitamin D was associated with a nonsignificant 6% reduction in CRC risk. Higher consumption of milk/dairy products reduces the risk of colon cancer, and high calcium intake reduces the risk of CRC. Low vitamin D intake in the study populations may limit the ability to detect a protective effect if one exists.

Direct observation of a photochemical activation energy: a case study of acetone photodissociation

NASA Astrophysics Data System (ADS)

Koch, Markus; Heim, Pascal; Thaler, Bernhard; Kitzler, Markus; Ernst, Wolfgang E.

2017-06-01

The ability to observe and quantify the conversion of electronic potential energy to vibrational kinetic energy in a molecule after photoexcitation is essential to understand and control the outcome of photoinduced molecular fragmentation. We exploit the high selectivity of photoelectron-photoion coincidence detection to distinguish different relaxation channels and observe the fragmentation behavior of each channel. We demonstrate the concept by investigating the fragmentation of gas-phase acetone molecules initiated by three-photon excitation to high lying Rydberg states between 9.0 and 9.5 eV above the ground state. By applying variations of the photon energy, pulse duration (100-200 fs) and pulse energy, we are able to fully characterize the fragmentation process. Rydberg states between 5s and 8s are populated, which undergo ultrafast internal conversion to lower states. The corresponding non-adiabatic dynamics in the neutral molecule cause the conversion of electronic to vibrational energy, leading to fragmentation. Our scheme allows us to directly measure the activation energy for fragmentation of acetone to an acetyl ion and a methyl radical, which we determine to be (0.79 ± 0.04) eV. Longer laser pulses result in an increased fragment-to-parent ratio, representing a higher probability for relaxation because the relaxation time constants are comparable to the pulse duration. Upon excitation to Rydberg states at 9.5 eV we surprisingly observe reduced fragmentation, although ˜2 eV are coupled into vibrational energy, indicating that different relaxation pathways become active, which results in a change of the redistribution of vibrational energy within the molecule. Fragmentation due to subsequent excitation of the cation is found to play a minor role.

Observational Case Series Evaluation of the Granisetron Transdermal Patch System (Sancuso) for the Management of Nausea/Vomiting of Pregnancy.

PubMed

Le, Tran N; Adler, Michael T; Ouillette, Holly; Berens, Pamela; Smith, Judith A

2017-07-01

Objective  The objective of this study was to observe the efficacy of antiemetic therapy (no emesis/retching episodes and no rescue medication use) when granisetron is administered via a transdermal patch system (TDS) in women who are 6 to 14 weeks pregnant when compared with oral ondansetron by evaluating the frequency of the use of rescue medications for control of nausea/vomiting of pregnancy (NVP). Methods  This was an observational case series study to observe the potential benefits of granisetron TDS compared with oral ondansetron for management of NVP in pregnant patients during the first trimester. Dates of data collection were September 1, 2014, through December 31, 2015. There was no direct contact with patient. The oral ondansetron and granisetron TDS patients were matched by age, 4:1. The proportion of patients who received rescue antiemetics was calculated from those patients who continued to experience NVP. Risk factors for NVP were identified and compared between groups. Descriptive statistics were used to describe study results. Results  Patients were prescribed rescue antiemetics in 0/3 patients in the granisetron TDS group compared with 2/12 patients in the oral ondansetron group. Conclusion  Prospective efficacy studies on the use of granisetron TDS for management of NVP are needed to confirm this clinical observation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Case-control study: soft-tissue sarcomas and exposure to phenoxyacetic acids or chlorophenols.

PubMed Central

Hardell, L.; Sandström, A.

1979-01-01

In 1977 a number of patients with soft-tissue sarcomas and previous exposure to phenoxyacetic acids were described. Following from these observations a matched case-control study was made. Exposure to chlorophenols was also included in this study. The results showed that exposure to phenoxyacetic acids or chlorophenols gave an approximately 6-fold increase in the risk for this type of tumour. It was not possible to determine, however, whether the carcinogenic effect was exerted by these compounds or by impurities such as chlorinated dibenzodioxins and dibenzofurans that in almost all cases were part of the commercial preparations. PMID:444410

Study on individual stochastic model of GNSS observations for precise kinematic applications

NASA Astrophysics Data System (ADS)

Próchniewicz, Dominik; Szpunar, Ryszard

2015-04-01

The proper definition of mathematical positioning model, which is defined by functional and stochastic models, is a prerequisite to obtain the optimal estimation of unknown parameters. Especially important in this definition is realistic modelling of stochastic properties of observations, which are more receiver-dependent and time-varying than deterministic relationships. This is particularly true with respect to precise kinematic applications which are characterized by weakening model strength. In this case, incorrect or simplified definition of stochastic model causes that the performance of ambiguity resolution and accuracy of position estimation can be limited. In this study we investigate the methods of describing the measurement noise of GNSS observations and its impact to derive precise kinematic positioning model. In particular stochastic modelling of individual components of the variance-covariance matrix of observation noise performed using observations from a very short baseline and laboratory GNSS signal generator, is analyzed. Experimental test results indicate that the utilizing the individual stochastic model of observations including elevation dependency and cross-correlation instead of assumption that raw measurements are independent with the same variance improves the performance of ambiguity resolution as well as rover positioning accuracy. This shows that the proposed stochastic assessment method could be a important part in complex calibration procedure of GNSS equipment.

Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials.

PubMed

Anglemyer, Andrew; Horvath, Hacsi T; Bero, Lisa

2014-04-29

. Comparisons included RCTs versus observational studies (including retrospective cohorts, prospective cohorts, case-control designs, and cross-sectional designs). Reviews were not eligible if they compared randomized trials with other studies that had used some form of concurrent allocation. In general, outcome measures included relative risks or rate ratios (RR), odds ratios (OR), hazard ratios (HR). Using results from observational studies as the reference group, we examined the published estimates to see whether there was a relative larger or smaller effect in the ratio of odds ratios (ROR).Within each identified review, if an estimate comparing results from observational studies with RCTs was not provided, we pooled the estimates for observational studies and RCTs. Then, we estimated the ratio of ratios (risk ratio or odds ratio) for each identified review using observational studies as the reference category. Across all reviews, we synthesized these ratios to get a pooled ROR comparing results from RCTs with results from observational studies. Our initial search yielded 4406 unique references. Fifteen reviews met our inclusion criteria; 14 of which were included in the quantitative analysis.The included reviews analyzed data from 1583 meta-analyses that covered 228 different medical conditions. The mean number of included studies per paper was 178 (range 19 to 530).Eleven (73%) reviews had low risk of bias for explicit criteria for study selection, nine (60%) were low risk of bias for investigators' agreement for study selection, five (33%) included a complete sample of studies, seven (47%) assessed the risk of bias of their included studies,Seven (47%) reviews controlled for methodological differences between studies,Eight (53%) reviews controlled for heterogeneity among studies, nine (60%) analyzed similar outcome measures, and four (27%) were judged to be at low risk of reporting bias.Our primary quantitative analysis, including 14 reviews, showed that the pooled ROR comparing

The Passive microwave Neural network Precipitation Retrieval (PNPR) algorithm for AMSU/MHS observations: description and application to European case studies

NASA Astrophysics Data System (ADS)

Sanò, P.; Panegrossi, G.; Casella, D.; Di Paola, F.; Milani, L.; Mugnai, A.; Petracca, M.; Dietrich, S.

2015-02-01

The purpose of this study is to describe a new algorithm based on a neural network approach (Passive microwave Neural network Precipitation Retrieval - PNPR) for precipitation rate estimation from AMSU/MHS observations, and to provide examples of its performance for specific case studies over the European/Mediterranean area. The algorithm optimally exploits the different characteristics of Advanced Microwave Sounding Unit-A (AMSU-A) and the Microwave Humidity Sounder (MHS) channels, and their combinations, including the brightness temperature (TB) differences of the 183.31 channels, with the goal of having a single neural network for different types of background surfaces (vegetated land, snow-covered surface, coast and ocean). The training of the neural network is based on the use of a cloud-radiation database, built from cloud-resolving model simulations coupled to a radiative transfer model, representative of the European and Mediterranean Basin precipitation climatology. The algorithm provides also the phase of the precipitation and a pixel-based confidence index for the evaluation of the reliability of the retrieval. Applied to different weather conditions in Europe, the algorithm shows good performance both in the identification of precipitation areas and in the retrieval of precipitation, which is particularly valuable over the extremely variable environmental and meteorological conditions of the region. The PNPR is particularly efficient in (1) screening and retrieval of precipitation over different background surfaces; (2) identification and retrieval of heavy rain for convective events; and (3) identification of precipitation over a cold/iced background, with increased uncertainties affecting light precipitation. In this paper, examples of good agreement of precipitation pattern and intensity with ground-based data (radar and rain gauges) are provided for four different case studies. The algorithm has been developed in order to be easily tailored to new

Chronic histiocytic intervillositis - Clinical, biochemical and radiological findings: An observational study.

PubMed

Koby, Lawrence; Keating, Sarah; Malinowski, Ann Kinga; D'Souza, Rohan

2018-04-01

Chronic histiocytic intervillositis (CHI) of the placenta although rare, has a high recurrence rate, is associated with serious adverse pregnancy outcomes and has no available treatment. This study aims to determine clinical, biochemical and radiological factors associated with CHI, to guide management of subsequent pregnancies. This retrospective observational study included consecutive cases with a histopathologic diagnosis of CHI after 18 weeks of gestation, between 2001 and 2014, and no controls. Clinical (maternal, fetal and delivery outcomes), biochemical (first- and second-trimester biomarkers for fetal aneuploidy and serum alkaline phosphatase) and radiological (second- and third-trimester fetal, placental and Doppler ultrasound) factors associated with a histopathological diagnosis of CHI were identified and results presented as percentages. Outcomes of subsequent pregnancies were described. Of 231 identified cases of 'intervillositis', 33 were confirmed to have CHI, of which only 4/33 (12.1%) had prior uncomplicated term deliveries. During pregnancy, 10/18 (55.5%) had abnormal first-trimester screening, 4/16 (25%) had abnormal second-trimester screening, 6/19 (31.6%) had at least one elevated alkaline phosphatase level, and 15/20 (75%) had at least one abnormal feature on mid-trimester placental ultrasound. In subsequent pregnancies that were closely followed with a combination of biochemical and radiologic tests, there were no cases of fetal loss, and lower incidence of fetal growth restriction and preterm birth. No clinical, biochemical or radiological finding is consistently associated with CHI and adverse outcomes thereof. Whether the incorporation of these tests in individualized care-plans could improve outcomes in subsequent pregnancies needs to be studied further. Copyright © 2018 Elsevier Ltd. All rights reserved.

Schematic representation of case study research designs.

PubMed

Rosenberg, John P; Yates, Patsy M

2007-11-01

The paper is a report of a study to demonstrate how the use of schematics can provide procedural clarity and promote rigour in the conduct of case study research. Case study research is a methodologically flexible approach to research design that focuses on a particular case - whether an individual, a collective or a phenomenon of interest. It is known as the 'study of the particular' for its thorough investigation of particular, real-life situations and is gaining increased attention in nursing and social research. However, the methodological flexibility it offers can leave the novice researcher uncertain of suitable procedural steps required to ensure methodological rigour. This article provides a real example of a case study research design that utilizes schematic representation drawn from a doctoral study of the integration of health promotion principles and practices into a palliative care organization. The issues discussed are: (1) the definition and application of case study research design; (2) the application of schematics in research; (3) the procedural steps and their contribution to the maintenance of rigour; and (4) the benefits and risks of schematics in case study research. The inclusion of visual representations of design with accompanying explanatory text is recommended in reporting case study research methods.

Evolution of a Campus Sustainability Network: A Case Study in Organizational Change

ERIC Educational Resources Information Center

Kurland, Nancy B.

2011-01-01

Purpose: The purpose of this paper is to examine the evolution of a sustainability network at a large California public university, as an example of organizational change. Design/methodology/approach: The paper combines participant observation and case study techniques over a three-year period. From 2007 to 2010, the author helped found the…

Echolalia versus Inclusion: A Case Study of a Child Who Is Blind.

ERIC Educational Resources Information Center

Zoniou-Sideri, Athina; Karayianni, Panagiota

2000-01-01

A case study of a Greek child (age 5) with visual impairment and echolalia is presented to illustrate the symptoms of echolalia in inclusive settings, the forms that echolalia can take, and how echolalia is differentiated from the kinds of speech repetitions observed in conditions of normal language acquisition. (Contains references.) (CR)

Remote Sensing based multi-temporal observation of North Korea mining activities : A case study of Rakyeon mine

NASA Astrophysics Data System (ADS)

Lim, J. H.; Yu, J.; Koh, S. M.; Lee, G.

2017-12-01

Mining is a major industrial business of North Korea accounting for significant portion of an export for North Korean economy. However, due to its veiled political system, details of mining activities of North Korea is rarely known. This study investigated mining activities of Rakyeon Au-Ag mine, North Korea based on remote sensing based multi-temporal observation. To monitor the mining activities, CORONA data acquired in 1960s and 1970s, SPOT and Landsat data acquired in 1980s and 1990s and KOMPSAT-2 data acquired in 2010s are utilized. The results show that mining activities of Rakyeon mine continuously carried out for the observation period expanding tailing areas of the mine. However, its expanding rate varies between the period related to North Korea's economic and political situations.

Questionnaire-based assessment of executive functioning: Case studies.

PubMed

Kronenberger, William G; Castellanos, Irina; Pisoni, David B

2018-01-01

Delays in the development of executive functioning skills are frequently observed in pediatric neuropsychology populations and can have a broad and significant impact on quality of life. As a result, assessment of executive functioning is often relevant for the development of formulations and recommendations in pediatric neuropsychology clinical work. Questionnaire-based measures of executive functioning behaviors in everyday life have unique advantages and complement traditional neuropsychological measures of executive functioning. Two case studies of children with spina bifida are presented to illustrate the clinical use of a new questionnaire measure of executive and learning-related functioning, the Learning, Executive, and Attention Functioning Scale (LEAF). The LEAF emphasizes clinical utility in assessment by incorporating four characteristics: brevity in administration, breadth of additional relevant content, efficiency of scoring and interpretation, and ease of availability for use. LEAF results were consistent with another executive functioning checklist in documenting everyday behavior problems related to working memory, planning, and organization while offering additional breadth of assessment of domains such as attention, processing speed, and novel problem-solving. These case study results demonstrate the clinical utility of questionnaire-based measurement of executive functioning in pediatric neuropsychology and provide a new measure for accomplishing this goal.

Peace Corps Water/Sanitation Case Studies and Analyses. Appropriate Technologies for Development. Case Study CS-4.

ERIC Educational Resources Information Center

Talbert, Diana E., Comp.

This document provides an overview of Peace Corps water and sanitation activities, five case studies (Thailand, Yemen, Paraguay, Sierra Leone, and Togo), programming guidelines, and training information. Each case study includes: (1) background information on the country's geography, population, and economics; (2) information on the country's…

Rethinking Case Study Methodology in Poststructural Research.

PubMed

Mohammed, Shan; Peter, Elizabeth; Gastaldo, Denise; Howell, Doris

2015-03-01

Little consideration has been given to how case study might be used in poststructural research to explore power relations that constitute a phenomenon. Many case study scholars, most notably Robert Yin, adopt a postpositivist perspective that assumes the "truth" can be accessed through applying prescriptive and rigid research techniques. Using a discussion of Michel Foucault's key theoretical ideas and the insights gained through a Foucauldian case study of people with advanced cancer who continue to receive curative treatment, the authors argue for the expansion of case study in poststructural inquiry. They propose that the use of poststructuralist case study is valuable because of the flexibility and comprehensiveness of the methodology, which allows for the exploration of a deeper understanding of the broader discourses that shape a phenomenon, as well as how power/knowledge relations shape the behaviours and perceptions of people. They also introduce the reflexive implications of poststructural case study research. Copyright© by Ingram School of Nursing, McGill University.

A systematic review of observational studies on oxidative/nitrosative stress involvement in dengue pathogenesis

PubMed Central

Pinzón, Hernando Samuel; Alvis-Guzman, Nelson

2015-01-01

Objective: Our objective was to systematically review the published observational research related to the role of oxidative-nitrosative stress in pathogenesis of dengue. Methods: We searched electronic databases (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) using the term: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide, and nitric oxide synthase. Articles were selected for review by title and abstract excluding letter, review, in vivo and in vitro studies, and duplicates studies. Selected articles were reviewed for study design, original purposes, sample size, main outcomes, methods, and oxidative-nitrosative stress markers values. Results: In total, 4,331 non-duplicates articles were identified from electronic databases searches, of which 16 were eligible for full text searching. Data from the observational studies originate from Asian countries (50%; 8/16), South American countries (31.2%; 5/16), and Central America and the Caribbean countries (18.8%; 3/16). Case-control study was the type of design most common in researches reviewed. The 1997 World Health Organization (WHO) dengue case classification criteria were used in all studies included in this review. Conclusions: Based on published data found in peer-reviewed literature, oxidative and nitrosative stress are demonstrated by changes in plasma levels of nitric oxide, antioxidants, lipid peroxidation and protein oxidation markers in patients with dengue infection. Additionally, elevated serum protein carbonyls and malondialdehyde levels appear to be associated with dengue disease severity. PMID:26600629

Alternative outcome definitions and their effect on the performance of methods for observational outcome studies.

PubMed

Reich, Christian G; Ryan, Patrick B; Schuemie, Martijn J

2013-10-01

A systematic risk identification system has the potential to test marketed drugs for important Health Outcomes of Interest or HOI. For each HOI, multiple definitions are used in the literature, and some of them are validated for certain databases. However, little is known about the effect of different definitions on the ability of methods to estimate their association with medical products. Alternative definitions of HOI were studied for their effect on the performance of analytical methods in observational outcome studies. A set of alternative definitions for three HOI were defined based on literature review and clinical diagnosis guidelines: acute kidney injury, acute liver injury and acute myocardial infarction. The definitions varied by the choice of diagnostic codes and the inclusion of procedure codes and lab values. They were then used to empirically study an array of analytical methods with various analytical choices in four observational healthcare databases. The methods were executed against predefined drug-HOI pairs to generate an effect estimate and standard error for each pair. These test cases included positive controls (active ingredients with evidence to suspect a positive association with the outcome) and negative controls (active ingredients with no evidence to expect an effect on the outcome). Three different performance metrics where used: (i) Area Under the Receiver Operator Characteristics (ROC) curve (AUC) as a measure of a method's ability to distinguish between positive and negative test cases, (ii) Measure of bias by estimation of distribution of observed effect estimates for the negative test pairs where the true effect can be assumed to be one (no relative risk), and (iii) Minimal Detectable Relative Risk (MDRR) as a measure of whether there is sufficient power to generate effect estimates. In the three outcomes studied, different definitions of outcomes show comparable ability to differentiate true from false control cases (AUC) and a

Embedding clinical interventions into observational studies

PubMed Central

Newman, Anne B.; Avilés-Santa, M. Larissa; Anderson, Garnet; Heiss, Gerardo; Howard, Wm. James; Krucoff, Mitchell; Kuller, Lewis H.; Lewis, Cora E.; Robinson, Jennifer G.; Taylor, Herman; Treviño, Roberto P.; Weintraub, William

2017-01-01

Novel approaches to observational studies and clinical trials could improve the cost-effectiveness and speed of translation of research. Hybrid designs that combine elements of clinical trials with observational registries or cohort studies should be considered as part of a long-term strategy to transform clinical trials and epidemiology, adapting to the opportunities of big data and the challenges of constrained budgets. Important considerations include study aims, timing, breadth and depth of the existing infrastructure that can be leveraged, participant burden, likely participation rate and available sample size in the cohort, required sample size for the trial, and investigator expertise. Community engagement and stakeholder (including study participants) support are essential for these efforts to succeed. PMID:26611435

Reducing selection bias in case-control studies from rare disease registries.

PubMed

Cole, J Alexander; Taylor, John S; Hangartner, Thomas N; Weinreb, Neal J; Mistry, Pramod K; Khan, Aneal

2011-09-12

In clinical research of rare diseases, where small patient numbers and disease heterogeneity limit study design options, registries are a valuable resource for demographic and outcome information. However, in contrast to prospective, randomized clinical trials, the observational design of registries is prone to introduce selection bias and negatively impact the validity of data analyses. The objective of the study was to demonstrate the utility of case-control matching and the risk-set method in order to control bias in data from a rare disease registry. Data from the International Collaborative Gaucher Group (ICGG) Gaucher Registry were used as an example. A case-control matching analysis using the risk-set method was conducted to identify two groups of patients with type 1 Gaucher disease in the ICGG Gaucher Registry: patients with avascular osteonecrosis (AVN) and those without AVN. The frequency distributions of gender, decade of birth, treatment status, and splenectomy status were presented for cases and controls before and after matching. Odds ratios (and 95% confidence intervals) were calculated for each variable before and after matching. The application of case-control matching methodology results in cohorts of cases (i.e., patients with AVN) and controls (i.e., patients without AVN) who have comparable distributions for four common parameters used in subject selection: gender, year of birth (age), treatment status, and splenectomy status. Matching resulted in odds ratios of approximately 1.00, indicating no bias. We demonstrated bias in case-control selection in subjects from a prototype rare disease registry and used case-control matching to minimize this bias. Therefore, this approach appears useful to study cohorts of heterogeneous patients in rare disease registries.

Lymphoid stromal reaction in gastrointestinal lymphomas: immunohistochemical study of 14 cases.

PubMed Central

Jarry, A; Brousse, N; Souque, A; Barge, J; Molas, G; Potet, F

1987-01-01

The lymphoid stromal reaction, particularly the T lymphoid reaction, was studied immunohistochemically on cryostat sections in 14 cases of primary gastrointestinal B lymphomas, and compared with the type and distribution of lymphoid cells in three cases of gastric lymphoid hyperplasia. A pronounced T lymphoid reaction, mainly of the T helper phenotype, occurred in both lesions. Most of these T cells bore HLA-DR antigens, but only a few of them had the receptor for interleukin 2. The T lymphoid reaction was observed inside the lymphomas in seven of a total of 14 cases, and around the lymphomas in four of the six cases clinically classified as stage I. Perivascular mucosal and submucosal nodules, entirely composed of T cells, seemed characteristic of gastric lymphoid hyperplasias. A T lymphoid reaction in lymphoid hyperplasias suggests an amplification of the cell mediated immune response; in lymphomas it could represent a host reaction against the lymphomatous infiltrate, therefore favouring a better prognosis. Images Fig 1 Fig 2 Fig 3 PMID:3305585

A Case Study to Evaluate Balance Training with Movement Test Items and through Teaching Observation: Beyond Specificity and Transfer of Learning

ERIC Educational Resources Information Center