988 resultados para investigative study


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OBJECTIVE The aim of this study was to directly compare metal artifact reduction (MAR) of virtual monoenergetic extrapolations (VMEs) from dual-energy computed tomography (CT) with iterative MAR (iMAR) from single energy in pelvic CT with hip prostheses. MATERIALS AND METHODS A human pelvis phantom with unilateral or bilateral metal inserts of different material (steel and titanium) was scanned with third-generation dual-source CT using single (120 kVp) and dual-energy (100/150 kVp) at similar radiation dose (CT dose index, 7.15 mGy). Three image series for each phantom configuration were reconstructed: uncorrected, VME, and iMAR. Two independent, blinded radiologists assessed image quality quantitatively (noise and attenuation) and subjectively (5-point Likert scale). Intraclass correlation coefficients (ICCs) and Cohen κ were calculated to evaluate interreader agreements. Repeated measures analysis of variance and Friedman test were used to compare quantitative and qualitative image quality. Post hoc testing was performed using a corrected (Bonferroni) P < 0.017. RESULTS Agreements between readers were high for noise (all, ICC ≥ 0.975) and attenuation (all, ICC ≥ 0.986); agreements for qualitative assessment were good to perfect (all, κ ≥ 0.678). Compared with uncorrected images, VME showed significant noise reduction in the phantom with titanium only (P < 0.017), and iMAR showed significantly lower noise in all regions and phantom configurations (all, P < 0.017). In all phantom configurations, deviations of attenuation were smallest in images reconstructed with iMAR. For VME, there was a tendency toward higher subjective image quality in phantoms with titanium compared with uncorrected images, however, without reaching statistical significance (P > 0.017). Subjective image quality was rated significantly higher for images reconstructed with iMAR than for uncorrected images in all phantom configurations (all, P < 0.017). CONCLUSIONS Iterative MAR showed better MAR capabilities than VME in settings with bilateral hip prosthesis or unilateral steel prosthesis. In settings with unilateral hip prosthesis made of titanium, VME and iMAR performed similarly well.

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The Industrial Hemp Investigative and Advisory Task Force was created to study the economic viability of industrial hemp production in Illinois, to identify any legal or other obstacles to industrial hemp production, and to make recommendations.

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For many decades, the Kingdom of Saudi Arabia has been widely known for being a reliable oil exporter. This fact, however, has not exempted it from facing significant domestic energy challenges. One of the most pressing of these challenges involves bridging the widening electricity supply-demand gap where, currently, the demand is growing at a very fast rate. One crucial means to address this challenge is through delivering power supply projects with maximum efficiency. Project delivery delay, however, is not uncommon in this highly capital-intensive industry, indicating electricity supplies are not coping with the demand increases. To provide a deeper insight into the challenges of project implementation and efficient practice, this research adopts a pragmatic approach by triangulating literature, questionnaires and semi-structured interviews. The research was conducted in the Saudi Arabian power supply industry – Western Operating Area. A total of 105 usable questionnaires were collected, and 28 recorded, semi-structured interviews were conducted, analysed and synthesised to produce a conceptual model of what constitutes the project implementation challenges in the investigated industry. This was achieved by conducting a comprehensive ranking analysis applied to all 58 identified and surveyed factors which, according to project practitioners in the investigated industry, contribute to project delay. 28 of these project delay factors were selected as the "most important" ones. Factor Analysis was employed to structure these 28 most important project delay factors into the following meaningful set of 7 project implementation challenges: Saudi Electricity Company's contractual commitments, Saudi Electricity Company's communication and coordination effectiveness, contractors' project planning and project control effectiveness, consultant-related aspects, manpower challenges and material uncertainties, Saudi Electricity Company's tendering system, and lack of project requirements clarity. The study has implications for industry policy in that it provides a coherent assessment of the key project stakeholders' central problems. From this analysis, pragmatic recommendations are proposed that, if enacted, will minimise the significance of the identified problems on future project outcomes, thus helping to ensure the electricity supply-demand gap is diminished.

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To investigate the relationship between vascular function parameters measured at the retinal and systemic level and known markers for cardiovascular risk in patients with impaired glucose tolerance (IGT). Sixty age- and gender- matched White-European adults (30 IGT and 30 normal glucose tolerance -NGT) were recruited for the study. Fasting plasma glucose, lipids and 24-hour blood pressure (BP) was measured in all subjects. Systemic vascular and endothelial function was assessed using carotid-artery intimal media thickness (cIMT) and flow mediated dilation (FMD). Retinal vascular reactivity was assessed by the Dynamic Retinal Vessel Analyser (DVA). Additionally, blood glutathione (GSH, GSSG and tGSH) and plasma von-Willebrand (vWF) factor levels were also measured. Individuals with IGT demonstrated higher BP values (p<0.001), fasting TG and TG:HDL ratios (p<0.001) than NGT subjects. Furthermore, Total:HDL-C ratios and Framingham scores were raised (p=0.010 and p<0.001 respectively). Blood glutathione levels (GSH, GSSG and tGSH) were lower (p<0.001, p=0.039 and p<0.001 respectively) while plasma vWF was increased (p=0.014) in IGT subjects compared to controls. IGT individuals also demonstrated higher IMT in right and left carotid arteries (p=0.017 and p=0.005, respectively) alongside larger brachial artery diameter (p=0.015), lower FMD% (p=0.026) and GTN induced dilation (GID) (p=0.012) than healthy controls. At the retinal arterial level, the IGT subjects showed higher baseline fluctuations (BDF) (p=0.026), longer reaction time (RT) (p=0.032) and reduced baseline-corrected flicker response (bFR) (p=0.045). In IGT subjects retinal BDF correlated with and Total:HDL (p= 0.003) and HDL-C (p= 0.004). Arterial RT also correlated with FMD (p=0.017) in IGT but not NGT subjects. In IGT individuals there is a relationship between macro- and microvascular function, as well as a direct correlation between the observed retinal microcirculatory changes and established plasma markers for CVD. Multifactorial preventive interventions to decrease vascular risk in these individuals should be considered.

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Purpose: Tilted disc syndrome has been described to be associated with obliquely directed long axis of the disc, oblique direction of vessels, retinal pigment epithelial conus, hypoplasia of retina, visual field defects and myopic astigmatism. This prospective study looks at corneal astigmatism in eyes with a tilted optic disc. Refractive errors in these eyes were also analyzed. Methods: Patients with tilted optic discs were identified prospectively by clinical evaluation (BI, VK). All the patients with obliquely directed long axis of the disc, oblique direction of vessels and retinal pigment epithelial conus were included in the study. Best corrected visual acuity, slit-lamp examination, optic disc measurements, keratometry and refraction were recorded. Results: Twenty four patients (41 eyes) were recruited for the study. Eighteen (75%) patients had bilateral tilted optic discs. Eighteen patients (75%) were females and six (25%) were males. The mean age was 62 years(range 9 – 86 years). 76% of the patients were myopic and 24% hypermetropic. The mean spherical equivalent was –7.49 dioptres (SD 1.7D, range +6D to -17D). The mean corneal astigmatism was 1.09D (SD 0.9D, range 0.25D to 3.80D). The 6 patients who had unilateral, untilted discs were used as a control group to compare their mean corneal astigmatism (1.32 D) with the rest. Student "t" test was performed. ("p" = 0.49). Conclusions: In our study, tilted disc syndrome was found to be largely bilateral and more commonly seen in females. Myopia was the commonest refractive error associated with this clinical condition. However, 24% of patients in this series were hypermetropic. No correlation between the tilting of the optic disc and significant corneal astigmatism was noted as previously reported.

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Purpose: To investigate whether regional long-term changes in peripapillary retinal flow, measured by scanning laser Doppler flowmetry (SLDF), occur in patients with primary open angle glaucoma (POAG). Methods: 31 healthy volunteers (mean age: 65 8.3 years) and 33 POAG patients (mean age: 71.2 7.6 years) were followed up every 4 months for 16 months. Using SLDF, three images of the superior and inferior optic nerve head were obtained for each subject. A 1010-pixel frame was used to measure blood flow, volume and velocity in the four quadrants of the peripapillary retina. Central 24-2 visual field testing was carried out at each visit. Repeated measures analysis of covariance was used to assess change over time between the normal and POAG groups for the SLDF parameters. Univariate linear regression analysis for mean deviation and glaucoma change probability (GCP) analysis were used to identify visual field progression. Results: Blood volume, flow and velocity measured in the inferior nasal quadrant of the peripapillary retina decreased significantly over time for the POAG group compared to the normal group (p=0.0073, 0.0097, 0.0095 respectively). Overall, 2 glaucoma patients showed a significantly deteriorating MD slope, while 7 patients showed visual field progression with GPA. All of the patients progressing with GPA, showed change in the superior hemifield and, of those, 14% showed change in the inferior hemifield. Conclusion: Glaucoma patients showed a decrease in blood flow, volume and velocity in the inferior nasal peripapillary retina. A regional variation in microvascular retinal capillary blood flow may provide insight into the pathogenesis of glaucomatous optic neuropathy. Keywords: 331 blood supply • 554 retina • 624 visual fields

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PURPOSE. We explored risk factors for myopia in 12- to 13-year-old children in Northern Ireland (NI). METHODS. Stratified random sampling was performed to obtain representation of schools and children. Cycloplegia was achieved using cyclopentolate hydrochloride 1%. Distance autorefraction was measured using the Shin-Nippon SRW-5000 device. Height and weight were measured. Parents and children completed a questionnaire, including questions on parental history of myopia, sociodemographic factors, childhood levels of near vision, and physical activity to identify potential risk factors for myopia. Myopia was defined as spherical equivalent ≤0.50 diopters (D) in either eye. RESULTS. Data from 661 white children aged 12-to 13-years showed that regular physical activity was associated with a lower estimated prevalence of myopia compared to sedentary lifestyles (odds ratio [OR] = 0.46 adjusted for age, sex, deprivation score, family size, school type, urbanicity; 95% confidence interval [CI], 0.23–0.90; P for trend = 0.027). The odds of myopia were more than 2.5 times higher among children attending academically-selective schools (adjusted OR = 2.66; 95% CI, 1.48–4.78) compared to nonacademically-selective schools. There was no evidence of an effect of urban versus nonurban environment on the odds of myopia. Compared to children with no myopic parents, children with one or both parents being myopic were 2.91 times (95% CI, 1.54–5.52) and 7.79 times (95% CI, 2.93– 20.67) more likely to have myopia, respectively. CONCLUSIONS. In NI children, parental history of myopia and type of schooling are important determinants of myopia. The association between myopia and an environmental factor, such as physical activity levels, may provide insight into preventive strategies.

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Contrary to interviewing guidelines, a considerable portion of witness interviews are not recorded. Investigators’ memory, their interview notes, and any subsequent interview reports therefore become important pieces of evidence; the accuracy of interviewers’ memory or such reports is therefore of crucial importance when interviewers testify in court regarding witness interviews. A detailed recollection of the actual exchange during such interviews and how information was elicited from the witness will allow for a better assessment of statement veracity in court. ^ Two studies were designed to examine interviewers’ memory for a prior witness interview. Study One varied interviewer note-taking and type of subsequent interview report written by interviewers by including a sample of undergraduates and implementing a two-week delay between interview and recall. Study Two varied levels of interviewing experience in addition to report type and note-taking by comparing experienced police interviewers to a student sample. Participants interviewed a mock witness about a crime, while taking notes or not, and wrote an interview report two weeks later (Study One) or immediately after (Study Two). Interview reports were written either in a summarized format, which asked interviewers for a summary of everything that occurred during the interview, or verbatim format, which asked interviewers to record in transcript format the questions they asked and the witness’s responses. Interviews were videotaped and transcribed. Transcriptions were compared to interview reports to score for accuracy and omission of interview content. ^ Results from both studies indicate that much interview information is lost between interview and report especially after a two-week delay. The majority of information reported by interviewers is accurate, although even interviewers who recalled information immediately after still reported a troubling amount of inaccurate information. Note-taking was found to increase accuracy and completeness of interviewer reports especially after a two week delay. Report type only influenced recall of interviewer questions. Experienced police interviewers were not any better at recalling a prior witness interview than student interviewers. Results emphasize the need to record witness interviews to allow for more accurate and complete interview reconstruction by interviewers, even if interview notes are available. ^

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Contrary to interviewing guidelines, a considerable portion of witness interviews are not recorded. Investigators’ memory, their interview notes, and any subsequent interview reports therefore become important pieces of evidence; the accuracy of interviewers’ memory or such reports is therefore of crucial importance when interviewers testify in court regarding witness interviews. A detailed recollection of the actual exchange during such interviews and how information was elicited from the witness will allow for a better assessment of statement veracity in court. Two studies were designed to examine interviewers’ memory for a prior witness interview. Study One varied interviewer note-taking and type of subsequent interview report written by interviewers by including a sample of undergraduates and implementing a two-week delay between interview and recall. Study Two varied levels of interviewing experience in addition to report type and note-taking by comparing experienced police interviewers to a student sample. Participants interviewed a mock witness about a crime, while taking notes or not, and wrote an interview report two weeks later (Study One) or immediately after (Study Two). Interview reports were written either in a summarized format, which asked interviewers for a summary of everything that occurred during the interview, or verbatim format, which asked interviewers to record in transcript format the questions they asked and the witness’s responses. Interviews were videotaped and transcribed. Transcriptions were compared to interview reports to score for accuracy and omission of interview content. Results from both studies indicate that much interview information is lost between interview and report especially after a two-week delay. The majority of information reported by interviewers is accurate, although even interviewers who recalled information immediately after still reported a troubling amount of inaccurate information. Note-taking was found to increase accuracy and completeness of interviewer reports especially after a two week delay. Report type only influenced recall of interviewer questions. Experienced police interviewers were not any better at recalling a prior witness interview than student interviewers. Results emphasize the need to record witness interviews to allow for more accurate and complete interview reconstruction by interviewers, even if interview notes are available.

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The aim of this paper is to analyse the state of the investigative journalism in Mexico, especially the one that is practiced at the local level in the provinces. That is, this research is based upon a case study conducted in Morelia, the capital city of the state of Michoacán. The empirical evidence will show that there is an evident divergence regarding the practice of the investigative journalism: on the one hand, journalists are aware of what this concept involves and they consider that they practice it on a regular basis; but, on the other, the content analysis prove otherwise. In other words, the account of what is actually printed significantly differs from the news workers’ perceptions, because the former shows a poorly developed journalistic investigation practice.

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Investigative interviews with alleged victims form the central plank of evidence in the prosecution of child sexual abuse. Despite interviewers being provided with a guiding framework, child sexual abuse cases are often not prosecuted because of poor-quality evidence. The purpose of this study was to elicit feedback from prosecutors about the structure and format of current interview protocols and the ways in which these could potentially be improved from an evidential perspective. Focus group discussions (ranging in length from 180 to 190 minutes) were conducted with 13 Crown prosecutors representing every jurisdiction of Australia. Thematic analysis of the focus group discussions revealed that prosecutors were supportive of the structure of interview protocols, however, concerns were raised about four of the interview elements. These elements were the oath and truth–lie competency test, the ground rules, the practice narrative and eliciting a disclosure. The prosecutors’ concerns and their implications for protocol developers and trainers are discussed.

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This study examined the investigative interviewing of Australian Aboriginal children in cases of alleged sexual abuse, with a focus on three commonly included components of interview protocols: ground rules, practice narrative, and substantive phase. Analysis of 70 field transcripts revealed that the overall delivery and practice of ground rules at the beginning of the interview was positively associated with the spontaneous usage of rules in children's narratives of abuse. When specifically examining the "don't know" rule, however, only practice had an effect of children's usage of the rule (as opposed to simple delivery or no delivery at all). Children spoke more words overall, and interviewers used more open-ended prompts during the substantive phase when the interviews contained a practice narrative. Children most often disclosed sexual abuse in response to an open-ended prompt; however, they produced the most words in response to suggestive prompts. This article concludes with a discussion of the effectiveness of ground rules, practice narratives, and questioning with Aboriginal children.

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Despite the development of improved performance test protocols by renowned researchers, there are still road networks which experience premature cracking and failure. One area of major concern in asphalt science and technology, especially in cold regions in Canada is thermal (low temperature) cracking. Usually right after winter periods, severe cracks are seen on poorly designed road networks. Quality assurance tests based on improved asphalt performance protocols have been implemented by government agencies to ensure that roads being constructed are at the required standard but asphalt binders that pass these quality assurance tests still crack prematurely. While it would be easy to question the competence of the quality assurance test protocols, it should be noted that performance tests which are being used and were repeated in this study, namely the extended bending beam rheometer (EBBR) test, double edge-notched tension test (DENT), dynamic shear rheometer (DSR) test and X-ray fluorescence (XRF) analysis have all been verified and proven to successfully predict asphalt pavement behaviour in the field. Hence this study looked to probe and test the quality and authenticity of the asphalt binders being used for road paving. This study covered thermal cracking and physical hardening phenomenon by comparing results from testing asphalt binder samples obtained from the storage ‘tank’ prior to paving (tank samples) and recovered samples for the same contracts with aim of explaining why asphalt binders that have passed quality assurance tests are still prone to fail prematurely. The study also attempted to find out if the short testing time and automated procedure of torsion bar experiments can replace the established but tedious procedure of the EBBR. In the end, it was discovered that significant differences in performance and composition exist between tank and recovered samples for the same contracts. Torsion bar experimental data also indicated some promise in predicting physical hardening.

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Objective: Despite the heterogeneity of Australian Aboriginal peoples, certain styles of relating are shared and are markedly different to the communication styles of non-Aboriginal peoples. These differences may affect the suitability of current investigative interview protocols to Australian Aboriginal children. This study aimed to qualitatively evaluate the applicability of an investigative interview protocol to Australian Aboriginal children and examine how it could be modified to better suit the communication styles in many Aboriginal communities. Method: A diverse group of 28 participants who had expertise in Aboriginal language and culture, as well as an understanding of the child investigative interview process, each partook in an in-depth semi-structured interview where they were prompted to reflect on Aboriginal language and culture with reference to a current interview protocol (in the context of sexual assault investigation). Results: Thematic analysis revealed overall support for the narrative-based structure of the interview protocol when eliciting information from Aboriginal children. A number of concerns were also identified, and these largely related to the syntax and vocabulary within the protocol, as well as the methods of questioning and building rapport with the child. Conclusions: Directions for future research and potential modifications to investigative interview protocols to better suit Aboriginal children are discussed.