NATURAL CONVECTION IN A CAVITY WITH A BLOCK MOUNTED ON IT

Düşey duvarına blok monte edilmiş oyuk içerisinde, bloğun yeri ve boyutunun doğal taşınım üzerindeki etkisi sayısal olarak incelenmiştir. Bloklar tamamen yalıtımlı ve blok yerleştirilmiş düşey duvarın diğer duvara göre daha sıcak olduğu kabul edilmiştir. Problem için zamana bağlı olmayan çözümler elde edilmiştir. Hesaplamalar Rayleigh sayısının 104<Ra<106 değerleri için yapılmıştır. Düşey duvara yerleştirilen bloğun doğal taşınım akış hareketi ve ısı transferini büyük ölçüde etkilediği tespit edilmiştir. In this study natural convection in a cavity with a block mounted on a vertical wall was investigated numerically. The effects of the placement and, the dimensions of block on natural convection were studied. The block mounted vertical wall was warmer than the outer vertical wall and block itself was insulated perfectly. A SIMPLEM algorithm was used based on finite control volume approach for calculations. Calculations were performed in the range of 103<Ra<105. It was found that the block mounted on the wall have significant effect on natural convection heat transfer and flow field

Use of sonic tomography to detect and quantify wood decay in living trees.

Premise of the studyField methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes.Methods and resultsLiving trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness.ConclusionsSonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees

Individual variation of the masticatory system dominates 3D skull shape in the herbivory-adapted marsupial wombats

BackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses - particularly those produced through mastication of tough food items - may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, allometry may not dominate within-species shape variation, even if it is a driver of evolutionary shape divergence; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of three species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraints act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species

Sternal plating for primary and secondary sternal closure; can it improve sternal stability?

<p>Abstract</p> <p>Background</p> <p>Sternal instability with mediastinitis is a very serious complication after median sternotomy. Biomechanical studies have suggested superiority of rigid plate fixation over wire cerclage for sternal fixation. This study tests the hypothesis that sternal closure stability can be improved by adding plate fixation in a human cadaver model.</p> <p>Methods</p> <p>Midline sternotomy was performed in 18 human cadavers. Four sternal closure techniques were tested: (1) approximation with six interrupted steel wires; (2) approximation with six interrupted cables; (3) closure 1 (wires) or 2 (cables) reinforced with a transverse sternal plate at the sixth rib; (4) Closure using 4 sternal plates alone. Intrathoracic pressure was increased in all techniques while sternal separation was measured by three pairs of sonomicrometry crystals fixed at the upper, middle and lower parts of the sternum until 2.0 mm separation was detected. Differences in displacement pressures were analyzed using repeated measures ANOVA and Regression Coefficients.</p> <p>Results</p> <p>Intrathoracic pressure required to cause 2.0 mm separation increased significantly from 183.3 ± 123.9 to 301.4 ± 204.5 in wires/cables alone vs. wires/cables plus one plate respectively, and to 355.0 ± 210.4 in the 4 plates group (p < 0.05). Regression Coefficients (95% CI) were 120 (47–194) and 142 (66–219) respectively for the plate groups.</p> <p>Conclusion</p> <p>Transverse sternal plating with 1 or 4 plates significantly improves sternal stability closure in human cadaver model. Adding a single sternal plate to primary closure improves the strength of sternal closure with traditional wiring potentially reducing the risk of sternal dehiscence and could be considered in high risk patients.</p

Stem cell‐derived enteroid cultures as a tool for dissecting host‐parasite interactions in the small intestinal epithelium.

Toxoplasma gondii and Cryptosporidium spp. can cause devastating pathological effects in humans and livestock, and in particular to young or immunocompromised individuals. The current treatment plans for these enteric parasites are limited due to long drug courses, severe side effects, or simply a lack of efficacy. The study of the early interactions between the parasites and the site of infection in the small intestinal epithelium has been thwarted by the lack of accessible, physiologically relevant, and species-specific models. Increasingly, 3D stem cell-derived enteroid models are being refined and developed into sophisticated models of infectious disease. In this review we shall illustrate the use of enteroids to spearhead research into enteric parasitic infections, bridging the gap between cell line cultures and in vivo experiments

Visual examination and dermoscopy, alone or in combination, for the diagnosis of keratinocyte skin cancers in adults

Background Early accurate detection of all skin cancer types is important to guide appropriate management, to reduce morbidity and to improve survival. Basal cell carcinoma (BCC) is almost always a localised skin cancer with potential to infiltrate and damage surrounding tissue, whereas a minority of squamous cell carcinoma (cSCC) and invasive melanoma are higher risk skin cancers with the potential to metastasise and cause death. Dermoscopy has become an important tool to assist specialist clinicians in the diagnosis of melanoma, and is increasingly used in primary care settings. Dermoscopy is a precision-built handheld illuminated magnifier that allows more detailed examination of the skin down to the level of the superficial dermis. Establishing the value of dermoscopy over and above visual inspection for the diagnosis of BCC or cSCC in primary and secondary care settings is critical to understanding its potential contribution to appropriate skin cancer triage, including referral of higher risk cancers to secondary care, the identification of low risk skin cancers that might be treated in primary care and to provide reassurance to those with benign skin lesions who can be safely discharged. Objectives To determine the diagnostic accuracy of visual inspection and dermoscopy, alone or in combination, for the detection of a) BCC and b) cSCC, in adults. Studies were separated according to whether the diagnosis was recorded face-to-face (in-person) or based on remote (image-based) assessment. Search methods We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles. Selection criteria Studies of any design that evaluated visual inspection and/or dermoscopy in adults with lesions suspicious for skin cancer, compared with a reference standard of either histological confirmation or clinical follow-up. Data collection and analysis Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic threshold were missing. We estimated accuracy using hierarchical summary ROC methods. Analysis of studies allowing direct comparison between tests was undertaken. To facilitate interpretation of results, we computed values of sensitivity at the point on the SROC curve with 80% fixed specificity and values of specificity with 80% fixed sensitivity. We investigated the impact of in-person test interpretation; use of a purposely developed algorithm to assist diagnosis; and observer expertise. Main results A total of 24 publications reporting on 24 study cohorts were included, providing 27 visual inspection datasets (8805 lesions; 2579 malignancies) and 33 dermoscopy datasets (6855 lesions; 1444 malignancies). The risk of bias was mainly low for the index test (for dermoscopy evaluations) and reference standard domains, particularly for in-person evaluations, and high or unclear for participant selection, application of the index test for visual inspection and for participant flow and timing. Concerns regarding the applicability of study findings were scored as ‘high’ or 'unclear' concern for almost all studies across all domains assessed. Selective participant recruitment, lack of reproducibility of diagnostic thresholds and lack of detail on observer expertise were particularly problematic. The detection of BCC was reported in 28 datasets; 15 on an in-person basis and 13 image-based. Analysis of studies by prior testing of participants and according to observer expertise was not possible due to lack of data. Studies were primarily conducted in participants referred for specialist assessment of lesions with available histological classification. No clear differences in accuracy were noted between dermoscopy studies undertaken in-person and those which evaluated images. The lack of effect observed is likely due to other sources of heterogeneity, including variations in the types of skin lesion studied, in dermatoscopes used, in the use of algorithms and varying thresholds for deciding on a positive test result. Meta-analysis found in-person evaluations of dermoscopy (7 evaluations; 4683 lesions and 363 BCCs) to be more accurate than visual inspection alone for the detection of BCC (8 evaluations; 7017 lesions and 1586 BCCs), with an RDOR of 8.2 (95% CI: 3.5 to 19.3; P < 0.001). This corresponds to predicted differences in sensitivity of 14% (93% vs 79%) at a fixed specificity of 80% and predicted differences in specificity of 22% (99% vs 77%) at a fixed sensitivity of 80%. Very similar results were observed for the image-based evaluations. When applied to a hypothetical population of 1000 lesions, of which 170 are BCC (based on median BCC prevalence across studies), an increased sensitivity of 14% from dermoscopy would lead to 24 fewer BCCs missed, assuming 166 false positive results from both tests. A 22% increase in specificity from dermoscopy with sensitivity fixed at 80% would result in 183 fewer unnecessary excisions assuming 34 BCCs missed for both tests. There was not enough evidence to assess the use of algorithms or structured checklists for either visual inspection or dermoscopy. Insufficient data were available to draw conclusions on the accuracy of either test for the detection of cSCC. Authors’ conclusions Dermoscopy may be a valuable tool for the diagnosis of BCC as an adjunct to visual inspection of a suspicious skin lesion following a thorough history-taking including assessment of risk factors for keratinocyte cancer. The evidence primarily comes from secondary care (referred) populations and populations with pigmented lesions or mixed lesion types. There is no clear evidence supporting the use of currently available formal algorithms to assist dermoscopy diagnosis

2016 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1003/thumbnail.jp

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707

Delayed allegations of sexual abuse, complainant credibility and juror verdict

This study investigated laypersons\u27 perceptions of memory evidence in a mock childhood sexual abuse trial. Results indicated that delay, memory type (continuous vs. recovered) and the nature of the alleged sexual assault (penetrative vs. fondling) influenced both how witnesses were perceived and the outcome of the trial

Effective protection of fish on inshore coral reefs depends on the scale of mangrove -reef connectivity

Connectivity is an important consideration in conservation, but is rarely quantified when assessing marine reserve performance. Mangrove-reef connectivity is known to enhance reserve effectiveness when habitats are close together (< 250 m apart). Coral reefs are, however, often farther from mangroves, making it difficult to integrate mangrove-reef connectivity into conservation more widely. To determine if connectivity affects reserve performance beyond 250 m, we examined effects on reef fish in Hervey Bay, Queensland, Australia. Reserves affected fish assemblages and enhanced the abundances of harvested species and key functional groups on reefs within 500 m of mangroves (about 10 times greater inside reserves), but not on isolated reefs. Connectivity can affect reserve performance over broader distances than previously shown. We suggest that connectivity effects on inshore reef fish may simply be amplified on reefs located closest to adjacent mangroves, provided those reefs are within the migratory capabilities of fish. Mangrove-reef connectivity should be viewed as an important conservation target and may be broadly incorporated into reserve design by prioritizing the protection of seascapes where mangroves and reefs are closest