1,952 research outputs found
Wind tunnel balance
A flow-through balance is provided which includes a non-metric portion and a metric portion which form a fluid-conducting passage in fluid communication with an internal bore in the sting. The non-metric and metric portions of the balance are integrally connected together by a plurality of flexure beams such that the non-metric portion, the metric portion and the flexure beams form a one-piece construction which eliminates mechanical hysteresis between the non-metric and the metric portion. The system includes structures for preventing the effects of temperature, pressure and pressurized fluid from producing asymmetric loads on the flexure beams. A temperature sensor and a pressure sensor are located within the fluid-conducting passage of the balance. The system includes a longitudinal bellows member connected at two ends to one of the non-metric portion and the metric portion and at an intermediate portion thereof to the other of (1) and (2). A plurality of strain gages are mounted on the flexure beams to measure strain forces on the flexure beams. The flexure beams are disposed so as to enable symmetric forces on the flexure beams to cancel out so that only asymmetric forces are measured as deviations by the strain gages
Integrated clinical pathways for lower limb orthopaedic surgeries: An updated systematic review
Objective
The objective of the study was to comprehensively synthesise the components of integrated clinical pathways (ICPs) and post-operative outcomes of patients undergone total hip and knee arthroplasty (THA & TKA) and hip fracture surgeries. Background
Previous systematic reviews examined components and effectiveness of ICPs for lower limb joint replacement and hip fracture surgeries. Design and Methods
An updated systematic review guided by the Whittemore and Knafl (2005) framework. Electronic databases, Ovid MEDLINE, EBSCOhost-CINAHL, the Cochrane Reviews and Trails, EMBASE and PubMed, were searched from 2007 to 31 January 2021. Due to the heterogeneity of the methods and data collection tools of included studies, pooling of the quantitative data was not possible. Therefore, the included studies were synthesised and presented narratively under subthemes of arthroplasty and hip fracture surgeries. The PRISMA checklist for systematic reviews was used. Results
Twenty-four studies met selection criteria with 11 examined ICPs for hip fracture and 13 for the THA and TKA. Twenty-one ICPs were reviewed, and 33 components were extracted. The most frequently included components for hip fracture subgroup were âdischarge disposition arrangementâ and âdedicated personnel and resourcesâ. âExercise planâ and âpain managementâ were for the arthroplasty subgroup. A significant reduction in the length of stay and post-operative complications were associated with the ICPs. Results were mixed for the effectiveness of ICPs in reducing unplanned hospital admissions, mortality rates, post-operative complications and hospital costs. Conclusion
The number of ICP components varied across studies. This review could not recommend a one size-fits-all ICP that could be adapted for use for patients undergoing hip fracture and joint replacement surgeries. Relevance for clinical practice
This review identified research evidence-based components considered as essential for the inclusion in ICPâs for hip fracture and arthroplasty surgeries. Further research is suggested to determine the patient experience and healthcare providersâ acceptance of ICPs
The Geodynamic Significance of Continental UHP Exhumation: New Constraints From the Tso Morari Complex, NW Himalaya
The burial and exhumation of continental crust to and from ultrahighâpressure (UHP) is an important orogenic process, often interpreted with respect to the onset and/or subduction dynamics of continentâcontinent collision. Here, we investigate the timing and significance of UHP metamorphism and exhumation of the Tso Morari complex, NorthâWest Himalaya. We present new petrochronological analyses of mafic eclogites and their hostârock gneisses, combining UâPb zircon, rutile and xenotime geochronology (highâprecision CAâIDâTIMS and highâspatial resolution LAâICPâMS), garnet element maps, and petrographic observations. Zircon from mafic eclogite have a CAâIDâTIMS age of 46.91 ± 0.07 Ma, with REE profiles indicative of growth at eclogite facies conditions. Those ages overlap with zircon rim ages (48.9 ± 1.2 Ma, LAâICPâMS) and xenotime ages (47.4 ± 1.4 Ma; LAâICPâMS) from the hosting Puga gneiss, which grew during breakdown of UHP garnet rims. We argue that peak zircon growth at 47â46 Ma corresponds to the onset of exhumation from UHP conditions. Subsequent exhumation through the rutile closure temperature, is constrained by new dates of 40.4 ± 1.7 and 36.3 ± 3.8 Ma (LAâICPâMS). Overlapping ages from Kaghan imply a coeval timeâframe for the onset of UHP exhumation across the NW Himalaya. Furthermore, our regional synthesis demonstrates a causative link between changes in the subduction dynamics of the IndiaâAsia collision zone at 47â46 Ma and the resulting midâEocene plate network reorganization. The onset of UHP exhumation therefore provides a tightly constrained timeâstamp significant geodynamic shifts within the orogen and wider plate network
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Substance use and at-risk mental state for psychosis in 2102 prisoners: the case for early detection and early intervention in prison
Aim
Prisoners exhibit high rates of substance use and mental health problems. In the present study, we sought to gain a detailed understanding of substance use amongst young prisoners to inform early detection and early intervention strategies in a prison setting.
Methods
This is a crossâsectional study of 2102 prisoners who were screened by the London Early Detection and Prevention in Prison Team (LEAP). Data on the use of substances were collected including age of first use, recent use, duration of use and polyâdrug use. The Prodromal Questionnaire â Brief Version was used to screen for the atârisk mental state.
Results
We found high rates of lifetime and recent use and low age of first use of a number of substances. We also found strong associations between substance use and screening positive for an atârisk mental state. Logistic regression analysis confirmed that use of any drug in the last year, polyâdrug and early use, as well as heavy alcohol use, were related to an increased risk of screening positive.
Conclusions
Substance use in the prison population is not only widespread and heavy but is also strongly linked with a higher risk of developing mental health problems. The need for early detection and early intervention in prison is discussed
Peptidoglycan synthesis drives a single population of septal cell wall synthases during division in Bacillus subtilis
Bacterial cell division requires septal peptidoglycan (sPG) synthesis by the divisome complex. Treadmilling of the essential tubulin homologue FtsZ has been implicated in septal constriction, though its precise role remains unclear. Here we used live-cell single-molecule imaging of the divisome transpeptidase PBP2B to investigate sPG synthesis dynamics in Bacillus subtilis. In contrast to previous models, we observed a single population of processively moving PBP2B molecules whose motion is driven by peptidoglycan synthesis and is not associated with FtsZ treadmilling. However, despite the asynchronous motions of PBP2B and FtsZ, a partial dependence of PBP2B processivity on FtsZ treadmilling was observed. Additionally, through single-molecule counting experiments we provide evidence that the divisome synthesis complex is multimeric. Our results support a model for B. subtilis division where a multimeric synthesis complex follows a single track dependent on sPG synthesis whose activity and dynamics are asynchronous with FtsZ treadmilling
Self-report and behavioural measures of impulsivity as predictors of impulsive behaviour and psychopathology in male prisoners
Impulsivity is an important factor in adverse outcomes such as substance use, problem gambling and psychopathology. Extensive research has shown these negative outcomes are associated with both self-report and behavioural measures of impulsivity but these two measurement domains are not themselves associated. There has been limited research in prison samples. This is surprising given the high variability in impulsive behaviours that should make them ideal for investigating the convergence of impulsivity measures. Using a cross sectional design we investigated the associations of impulsivity â measured by self-report and two behavioural indices - with substance misuse and psychopathology in a sample of 72 male prisoners. We found higher self-reported impulsivity was associated with crack/cocaine use, problem gambling and a positive screen for personality disorder. Behavioural measures of impulsivity showed fewer associations with problematic behaviours; they were also not independent predictors of impulsive behaviour in multivariate analyses. These data suggest that self-reported impulsivity is a more consistent predictor of problematic behaviours than behavioural measures in a sample of people with significant levels of substance use and psychopathology. This difference could reflect relevance of self-reported measures to emotionally charged decision-making in daily life compared to more neutral behavioural measures
Investigating the effects of planting date and Aphis gossypii management on reducing the final incidence of cotton leafroll dwarf virus
This is the first study to research management strategies for cotton leafroll dwarf virus (CLRDV) in the southeastern U.S. The efficacy of aphid vector management to reduce final CLRDV incidence was investigated concurrent with efforts to monitor aphid population dynamics and timing of CLRDV spread. Adjusting the planting date and insecticide applications did not reduce the final incidence of CLRDV, which was confirmed in 60â100% of plants per plot using RT-PCR. Aphid population density was reduced, but not eliminated with foliar insecticide applications. Aphis gossypii was the only species observed on cotton and was the dominant species collected in pan traps. Three distinct periods of virus spread were detected with sentinel plants including early, mid-and late-season. Most virus spread occurred during large aphid dispersal events
The Cycladic Blueschist Unit on Tinos, Greece: Cold NE Subduction and SW Directed Extrusion of the Cycladic Continental Margin Under the Tsiknias Ophiolite
High pressureâlow temperature (HPâLT) metamorphic rocks structurally beneath the Tsiknias Ophiolite make up the interior of Tinos Island, Greece, but their relationship with the overlying ophiolite is poorly understood. Here, new field observations are integrated with petrological modeling of eclogite and blueschists to provide new insight into their tectonothermal evolution. Pseudomorphed lawsoniteâ, garnetâ, and glaucophaneâbearing schists exposed at the highest structural levels of Tinos (Kionnia and Pyrgos Subunits) reached ~22â26 kbar and 490â520°C under waterâsaturated conditions, whereas pseudomorphed lawsoniteâ and aegirineâomphacite bearing eclogite reached ~20â23 kbar and 530â570°C. These rocks are separated from rocks at deeper structural levels (Sostis Subunit) by a topâtoâSW thrust. The Sostis Subunit records PâT conditions of ~18.5 kbar and 480â510°C and is overprinted by pervasive topâtoâNE shearing that developed during exhumation from (M1) blueschist to (M2) greenschist facies conditions of ~7.3 ± 0.7 kbar and 536 ± 16°C. These PâTâD relationships suggest that the Cycladic Blueschist Unit represents a discrete series of tectonometamorphic subunits that each experienced different tectonic and thermal histories. These subunits were buried to variable depths and sequentially extruded toward the SW from a NE dipping subduction zone. The difference in age and PâT conditions between the HPâLT rocks and the overlying metamorphic sole of the Tsiknias Ophiolite suggests that this NE dipping subduction zone was active between circa 74 and 46 Ma and cooled at a minimum rate of ~1.2â1.5°C/km/Myr prior to continentâcontinent collision between Eurasia and Adria/Cyclades
Compressional origin of the Naxos metamorphic core complex, Greece: structure, petrography, and thermobarometry
The island of Naxos, Greece, has been previously considered to represent a Cordilleran-style metamorphic core complex that formed during Cenozoic extension of the Aegean Sea. Although lithospheric extension has undoubtedly occurred in the region since 10 Ma, the geodynamic history of older, regional-scale, kyanite- and sillimanite-grade metamorphic rocks exposed within the core of the Naxos dome is controversial. Specifically, little is known about the pre-extensional prograde evolution and the relative timing of peak metamorphism in relation to the onset of extension. In this work, new structural mapping is presented and integrated with petrographic analyses and phase equilibrium modeling of blueschists, kyanite gneisses, and anatectic sillimanite migmatites. The kyanite-sillimaniteâgrade rocks within the core complex record a complex history of burial and compression and did not form under crustal extension. Deformation and metamorphism were diachronous and advanced down the structural section, resulting in the juxtaposition of several distinct tectono-stratigraphic nappes that experienced contrasting metamorphic histories. The Cycladic Blueschists attained âŒ14.5 kbar and 470 °C during attempted northeast-directed subduction of the continental margin. These were subsequently thrusted onto the more proximal continental margin, resulting in crustal thickening and regional metamorphism associated with kyanite-grade conditions of âŒ10 kbar and 600â670 °C. With continued shortening, the deepest structural levels underwent kyanite-grade hydrous melting at âŒ8â10 kbar and 680â750 °C, followed by isothermal decompression through the muscovite dehydration melting reaction to sillimanite-grade conditions of âŒ5â6 kbar and 730 °C. This decompression process was associated with top-to-the-NNE shearing along passive-roof faults that formed because of SW-directed extrusion. These shear zones predated crustal extension, because they are folded around the migmatite dome and are crosscut by leucogranites and low-angle normal faults. The migmatite dome formed at lower-pressure conditions under horizontal constriction that caused vertical boudinage and upright isoclinal folds. The switch from compression to extension occurred immediately following doming and was associated with NNE-SSW horizontal boudinage and top-to-the-NNE brittle-ductile normal faults that truncate the internal shear zones and earlier collisional features. The Naxos metamorphic core complex is interpreted to have formed via crustal thickening, regional metamorphism, and partial melting in a compressional setting, here termed the Aegean orogeny, and it was exhumed from the midcrust due to the switch from compression to extension at ca. 15 Ma
The age, origin and emplacement of the Tsiknias Ophiolite, Tinos, Greece
The Tsiknias Ophiolite, exposed at the highest structural levels of Tinos, Greece, represents a thrust sheet of Tethyan oceanic crust and upper mantle emplaced onto the AtticâCycladic Massif. We present new field observations and a new geological map of Tinos, integrated with petrology, THERMOCALC phase diagram modelling, UâPb geochronology and whole rock geochemistry, resulting in a tectonoâthermal model that describes the formation and emplacement of the Tsiknias Ophiolite and newly identified underlying metamorphic sole. The ophiolite comprises a succession of partially dismembered and structurally repeated ultramafic and gabbroic rocks that represent the Moho Transition Zone. A plagiogranite dated by UâPb zircon at 161.9 ± 2.8 Ma, reveals that the Tsiknias Ophiolite formed in a supraâsubduction zone setting, comparable to the âEastâVardar Ophiolitesâ, and was intruded by gabbros at 144.4 ± 5.6 Ma. Strongly sheared metamorphic sole rocks show a condensed and inverted metamorphic gradient, from partially anatectic amphibolites at PâT conditions of ca. 8.5 kbar 850â600 °C, downâstructural section to greenschistâfacies oceanic metasediments over ~250 m. Leucosomes generated by partial melting of the uppermost sole amphibolite, yielded a UâPb zircon protolith age of ca. 190 Ma and a highâgrade metamorphicâanatectic age of 74.0 ± 3.5 Ma associated with ophiolite emplacement. The Tsiknias Ophiolite was therefore obducted ~90 Myrs after it formed during initiation of a NEâdipping intraâoceanic subduction zone to the northeast of the Cyclades that coincides with Africa's plate motion changing from transcurrent to convergent. Continued subduction resulted in highâpressure metamorphism of the Cycladic continental margin ~25 Myrs later
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