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Throughout their 250 Myr history, archosaurian reptiles have exhibited a wide array of body sizes, shapes, and locomotor habits, especially in regard to terrestriality. These features make Archosauria a useful clade with which to study the interplay between body size, shape, and locomotor behavior, and how this interplay may have influenced locomotor evolution. Here, digital volumetric models of 80 taxa are used to explore how mass properties and body proportions relate to each other and locomotor posture in archosaurs. One-way, nonparametric, multivariate analysis of variance, based on the results of principal components analysis, shows that bipedal and quadrupedal archosaurs are largely distinguished from each other on the basis of just four anatomical parameters (p < 0.001): mass, center of mass position, and relative forelimb and hindlimb lengths. This facilitates the development of a quantitative predictive framework that can help assess gross locomotor posture in understudied or controversial taxa, such as the crocodile-line Batrachotomus (predicted quadruped) and Postosuchus (predicted biped). Compared with quadrupedal archosaurs, bipedal species tend to have relatively longer hindlimbs and a more caudally positioned whole-body center of mass, and collectively exhibit greater variance in forelimb lengths. These patterns are interpreted to reflect differing biomechanical constraints acting on the archosaurian Bauplan in bipedal versus quadrupedal groups, which may have shaped the evolutionary histories of their respective members.
Background: Transmission of carbapenemase-producing organisms (CPO) threatens patient safety in healthcare facilities. As a result of a 2011 outbreak of blaKPC+ Klebsiella pneumoniae, the NIH Clinical Center (NIHCC) has prioritized early detection and isolation of CPO carriers, using point-prevalence surveys and targeted high-risk ward surveillance since 2011 and admission surveillance since 2013. We describe our experience over 6 years of admission surveillance. Methods: The NIHCC is a 200-bed research hospital that provides care for a highly immunocompromised patient population. From September 2013 to September 2019, perirectal swabs were ordered automatically for all patients on admission to nonbehavioral health wards. Swabs were ordered twice weekly for ICU patients, weekly in other high-risk wards, and monthly for hospital-wide point prevalence (excluding behavioral health). Patients hospitalized in the United States in the previous week or abroad in the previous 6 months were considered high risk for carriage and isolated pending results from 2 swabs. Most swabs (n = 37,526) were cultured onto HardyCHROM CRE. If gram-negative bacilli (GNB) were present, a molecular screen for carbapenemases was performed on a sweep of cultured material (day 1) pending organism isolation. GNB were identified by MALDI-TOF MS. Prior to June 2019, isolates were screened by blaKPC/blaNDM PCR. Starting in June 2019, Enterobacteriaceae and Pseudomonas aeruginosa were screened using the phenotypic modified carbapenem inactivation method (mCIM), reflexing to the GeneXpert CARBA-R molecular assay if positive; other GNB were tested directly with CARBA-R. Selected GNB underwent susceptibility testing (Sensititre). Whole-genome sequencing was used to assess relatedness among CPO isolates. Swabs from high-risk patients were tested directly by blaKPC PCR (n = 699) until August 2019 (most in parallel with culture) and thereafter by CARBA-R (n = 13). Results: Among 54,188 orders for perirectal swabs, 38,238 were collected from 14,497 patients (compliance 71%). Among 33 CPO-colonized patients identified from September 2013 through September 2019, 15 were identified on admission, 6 were identified in point-prevalence surveys, 8 were identified from high-risk ward surveillance, and 4 were identified from clinical cultures. Sequencing demonstrated no relatedness among CPO isolates. Although only 1.4% of patients sampled on admission were colonized with CPO, those meeting high-risk criteria were 21 times as likely to be colonized. Conclusion: Admission surveillance for CPO identified a low rate of colonization, but it detected nearly half of known CPO-colonized NIHCC patients over the past 6 years. Modest compliance with swab collection leaves room for improvement and likely results in missed instances of colonization. Although we cannot determine its effectiveness, we view our strategy as one of several key safety measures for our highly vulnerable patient population.
Current policy emphasises the importance of ‘living well’ with dementia, but there has been no comprehensive synthesis of the factors related to quality of life (QoL), subjective well-being or life satisfaction in people with dementia. We examined the available evidence in a systematic review and meta-analysis. We searched electronic databases until 7 January 2016 for observational studies investigating factors associated with QoL, well-being and life satisfaction in people with dementia. Articles had to provide quantitative data and include ⩾75% people with dementia of any type or severity. We included 198 QoL studies taken from 272 articles in the meta-analysis. The analysis focused on 43 factors with sufficient data, relating to 37639 people with dementia. Generally, these factors were significantly associated with QoL, but effect sizes were often small (0.1–0.29) or negligible (<0.09). Factors reflecting relationships, social engagement and functional ability were associated with better QoL. Factors indicative of poorer physical and mental health (including depression and other neuropsychiatric symptoms) and poorer carer well-being were associated with poorer QoL. Longitudinal evidence about predictors of QoL was limited. There was a considerable between-study heterogeneity. The pattern of numerous predominantly small associations with QoL suggests a need to reconsider approaches to understanding and assessing living well with dementia.
To conduct a full economic evaluation assessing the costs and consequences related to probiotic use for the primary prevention of Clostridium difficile–associated diarrhea (CDAD).
Cost-effectiveness analysis using decision analytic modeling.
A cost-effectiveness analysis was used to evaluate the risk of CDAD and the costs of receiving oral probiotics versus not over a time horizon of 30 days. The target population modeled was all adult inpatients receiving any therapeutic course of antibiotics from a publicly funded healthcare system perspective. Effectiveness estimates were based on a recent systematic review of probiotics for the primary prevention of CDAD. Additional estimates came from local data and the literature. Sensitivity analyses were conducted to assess how plausible changes in variables impacted the results.
Treatment with oral probiotics led to direct costs of CDN $24 per course of treatment per patient. On average, patients treated with oral probiotics had a lower overall cost compared with usual care (CDN $327 vs $845). The risk of CDAD was reduced from 5.5% in those not receiving oral probiotics to 2% in those receiving oral probiotics. These results were robust to plausible variation in all estimates.
Oral probiotics as a preventive strategy for CDAD resulted in a lower risk of CDAD as well as cost-savings. The cost-savings may be greater in other healthcare systems that experience a higher incidence and cost associated with CDAD.
Recent predictions from competing theoretical models have disagreed about the stability/instability of bi-periodic patterns of surface waves on deep water. We present laboratory experiments to address this controversy. Growth rates of modulational perturbations are compared to predictions from: (i) inviscid coupled nonlinear Schrödinger (NLS) equations, according to which the patterns are unstable and (ii) dissipative coupled NLS equations, according to which they are linearly stable. For bi-periodic wave patterns of small amplitude and nearly permanent form, we find that the dissipative model predicts the experimental observations more accurately. Hence, our experiments support the claim that these bi-periodic wave patterns are linearly stable in the presence of damping. For bi-periodic wave patterns of large enough amplitude or subject to large enough perturbations, both models fail to predict accurately the observed behaviour, which includes frequency downshifting.
Reducing water ingress into the Shaft at Dounreay is essential for the success of future intermediate level waste (ILW) recovery using the dry retrieval method. The reduction is being realised by forming an engineered barrier of ultrafine cementitious grout injected into the fractured rock surrounding the Shaft. Grout penetration of 6m in <50μm fractures is being reliably achieved, with a pattern of repeated injections ultimately reducing rock mass permeability by up to three orders of magnitude.
An extensive field trials period, involving over 200 grout mix designs and the construction of a full scale demonstration barrier, has yielded several new field techniques that improve the quality and reliability of cementitious grout injection for engineered barriers.
In particular, a new method has been developed for tracking in real-time the spread of ultrafine cementitious grout through fractured rock and relating the injection characteristics to barrier design. Fieldwork by the multi-disciplinary international team included developing the injection and real-time monitoring techniques, pre- and post injection hydro-geological testing to quantify the magnitude and extent of changes in rock mass permeability, and correlation of grout spread with injection parameters to inform the main works grouting programme.
In this paper, recent advancements related to a novel approach for fabricating low cost capacitive radio frequency microelectromechanical (RF MEMS) switches using directly photodefinable high dielectric constant metal oxides are discussed. In this approach, a radiation sensitive metal-organic precursor is deposited via spin coating and converted patternwise to a metal oxide using exposure to ultraviolet light. The feasibility of this approach has previously been demonstrated by fabricating bridge-type and cantilever-type RF MEMS switches. These early experiments showed that the photopatterned oxides displayed dielectric breakdown strengths that were insufficient for reliable operation of MEMS switches which required actuation voltages on the order of 20 V to 30 V. Recent work has focused on developing advanced processes based on the photodefinable metal-organic approach that can produce oxides with higher dielectric breakdown strengths and higher dielectric constants. A variety of post-patterning processes, including thermal baking and oxygen plasma annealing, were investigated and the impact of such processing on the resulting dielectric properties are discussed in this paper. It is shown that a combination of thermal annealing and oxygen plasma treatment can substantially improve the dielectric breakdown strength of the metal oxides produced using the photosensitive metal-organic process.
Echinochiton dufoei new genus and species is described from the Ordovician age Forreston Member, Grand Detour Formation (Blackriveran) near Beloit, Wisconsin. For a variety of reasons, we regard E. dufoei as a chiton; the species is known from four articulated or partially articulated specimens, one of which has eight plates and two of which have a mucro on the tail plate. Echinochiton dufoei differs from other chitons in having large hollow spines that project from each of the known plates. In plate shape and position, E. dufoei is much like the Upper Cambrian species Matthevia variabilis Walcott, 1885, and the Lower Ordovician species Chelodes whitehousei Runnegar, Pojeta, Taylor, and Collins (1979).
In this paper, a novel approach for fabricating low cost capacitive RF MEMS switches using directly photodefinable high dielectric constant metal oxides has been developed. In this approach, a radiation sensitive metal-organic precursor is deposited via spin coating and converted patternwise to a high dielectric constant metal oxide via ultraviolet exposure. The feasibility of this approach is demonstrated by fabricating bridge-type and cantilever-type switches with a nitride/metal-oxide/nitride dielectric film stack. These switches exhibited significantly higher isolation and load capacitances as compared to comparable switches fabricated using a simple silicon nitride dielectric.
An experiment using three New Zealand herds and a total of 632 cows, examined the effect of localised prophylactic treatments with antibiotic at drying-off on the incidence of new intramammary infection during the dry period and at calving. Antibiotic was infused either into the teat canal (0·22 g of dry-cow formulation) or the teat sinus (3·1 g of lactating-cow formulation) of uninfected quarters to eliminate any bacteria present in these locations at the last milking of lactation. These treatments were compared with a negative control (nil treatment) and a positive antibiotic control (infusion of 3·6 g of dry-cow formulation). All antibiotic formulations used the same active ingredient, sodium cloxacillin. No significant reduction in new dry period clinical mastitis was observed for the two localised treatments whereas the positive control treatment achieved 100% reduction in new clinical mastitis compared with untreated control quarters. A 41% reduction (P<0·05) in new Streptococcus uberis infections at calving was associated with the teat canal antibiotic treatment, compared with an 82% reduction (P<0·001) for the positive antibiotic control. Both localised treatments showed a reduced incidence of new intramammary infection (P<0·001) when pooled across periods and pathogens. Teats receiving either the teat canal antibiotic treatment or a full infusion of long acting dry-cow antibiotic had a lower incidence of open teat canals (P<0·05) at 3 weeks after drying-off.
The bed-forming brittlestars Ophiothrix fragilis, Ophiocomina nigra and Amphiura chiajei from Oban Bay, Scotland were studied using methods previously employed to study chemoautotrophic symbioses. Ophiothrix fragilis and A. chiajei both contain symbiotic bacteria (SCB) while Ophiocomina nigra is non-symbiotic. Samples were taken of Ophiothrix fragilis at approximately two-week intervals for one year. Symbiotic bacteria numbers were determined by direct counting of homogenates of the arms of 50 individual brittlestars. Water samples were analysed for chlorophyll content. Stable isotope ratios for carbon and nitrogen were determined for each homogenate sample. Regular SCB counts were made on the infaunal brittlestar A. chiajei. Homogenate samples of Ophiothrix fragilis, A. chiajei and the non-symbiotic Ophiocomina nigra were analysed to produce fatty acid profiles for each species. Symbiotic bacteria count varied by up to one order of magnitude in both Ophiothrix fragilis and A. chiajei with no evidence of seasonality in this variation. Symbiotic bacteria number was inversely correlated with δ15N but no relationship was established with δ13C. 16:1ω7 and 18:1.ω7 fatty acids were used as putative bacterial markers. Both symbiotic species had higher percentages of 16:1ω7 than the non-symbiotic Ophiocomina nigra. However, only Ophiothrix fragilis appeared to receive appreciable quantities of 18:1ω7 from its SCB. The SCB are heterotrophic and may contribute to the nitrogen budget of the host. The two symbiotic species studied here derive the bulk of their nutrition from conventional feeding but SCB make significant, additional contributions.
Pylyshyn defends a distinction between early visual perception
and cognitive processing. But exactly where should the line between
vision and cognition be drawn? Our research on object identification
suggests that the construction of an object's visual description
is isolated from contextually derived expectations. Moreover, the
matching of constructed descriptions to stored descriptions appears
to be similarly isolated.