This study examined the influence of maturation on the oxygen uptake efficiency slope (OUES) in healthy male subjects. Seventy-six healthy male subjects (8-27 yr) were divided into groups based on ...maturation status: prepubertal (PP), midpubertal (MP), late-pubertal (LP), and young-adult (YA) males. Puberty status was determined by physical examination. Subjects performed a graded exercise test on a cycle ergometer to determine OUES. Group differences were assessed using a one-way ANOVA. OUES values (VO(2)L·min(-1)/log(10)V(E)L·min(-1)) were lower in PP and MP compared with LP and YA (p < .05). When OUES was expressed relative to body mass (VO(2)mL·kg-1·min(-1)/log(10)V(E)mL·kg(-1)·min(-1)) differences between groups reversed whereby PP and MP had higher mass relative OUES values compared with LP and YA (p < .05). Adjusting OUES by measures of body mass failed to eliminate differences across maturational groups. This suggests that qualitative factors, perhaps related to oxidative metabolism, account for the responses observed in this study.
Nontraumatic subdural hematoma (SDH) is a common neurological disease that causes extensive morbidity and mortality. Craniotomy or burr hole craniostomy (BHC) is indicated for symptomatic lesions, ...but both are associated with high recurrence rates. Although extensive research exists on postoperative complications after BHCs, few studies have examined the underlying causes and predictors of unplanned 30-day hospital readmissions at the national level.
To compare causes for hospital readmission within 30 days after surgical SDH evacuation with BHC and evaluate readmission rates and independent predictors of readmission.
This retrospective cohort observational study was designed using the Nationwide Readmissions Database. We identified patients who had undergone BHC for SDH evacuation (2010-2015). National estimates and variances within the cohort were calculated after stratifying, hospital clustering, and weighting variables.
We analyzed 2753 patients who had BHC for SDH evacuation: 675 (24.5%) had at least one 30-day readmission. Annual readmission rates did not vary across the study period ( P = .60). The most common cause of readmission was recurrent SDH (n = 630, 93.3%), and the next most common was postoperative infection (n = 12, 1.8%). Comorbidities significantly associated with readmission included fluid and electrolyte disorders, chronic blood loss anemia, chronic obstructive pulmonary disease, depression, liver disease, and psychosis ( P ≤ .04), but statistically significant independent predictors for readmission included only chronic obstructive pulmonary disease and fluid and electrolyte disorders ( P ≤ .007).
These national trends in 30-day readmission rates after nontraumatic SDH evacuation by BHC not otherwise published provide quality benchmarks that can aid national quality improvement efforts.
Abstract Primordial black holes (PBHs) can be produced by a range of mechanisms in the early universe. A particular formation channel that connects PBHs with inflationary phenomenology invokes ...enhanced primordial curvature perturbations at small scales. In this paper, we examine how rapidly the background can transition between different values of the parameters of the Hubble hierarchy in the context of single-clock inflation, which must ultimately derive from a consistent derivative expansion for the background inflaton field. We discuss artefacts associated with instant or very rapid transitions, and consider the impact on the steepest power spectrum growth and the formation of PBHs. In particular, we highlight the robustness of the k 4 steepest growth previously found for single-field inflation with conservatively smoothed transitions and limits on how much the amplitude of the power spectrum can grow, and demonstrate that the PBH mass distribution is sensitive to the artefacts, which go away when the transitions are smoothed. We also show that the mass distribution is relatively insensitive to the steepness of the growth and subsequent decay of the power spectrum, depending primarily on the peak amplitude and the presence of any plateaus that last more than an e-fold. The shape of the power spectrum can of course be constrained by other tracers, and so understanding the physical limitations on its shape remains a pertinent question.
Additive manufacturing (AM) of injection moulding (IM) tools has attracted significant interest in the polymer manufacturing industry for quite some time. However, hybrid manufacturing (HM) using ...directed energy deposition (DED), which involves concurrent additive and subtractive manufacture, has not been a commonly used process for IM tooling manufacture. This is apparent despite several advantages over the prevalent laser-powder bed fusion (L-PBF) alternative, including higher build rate, lower cost and integrated machining to directly achieve higher tolerances and surface finish. A key reason for this low utilisation is the limited ability of DED processes to produce circular channel profiles typically used in IM tooling, due to stricter constraints on the manufacturability of overhanging geometry. To address this, a range of self-supporting IM cooling channel profiles suited for hybrid laser and powder-based DED manufacture are proposed in this work. Numerical and experimental evaluations are conducted of the cooling performance of several non-circular conformal cooling channel (NCCC) profiles to identify a profile which achieves the maximum heat transfer for a constant cross-sectional area and coolant flow rate. Experimental studies included AM builds to evaluate the DED manufacturability of the selected NCCC profile on a conformally cooled HM benchmark model, followed by cooling performance characterisation, including a comparison against a reference L-PBF manufactured benchmark model. In conclusion, a shape correcting factor is obtained using response surfaces. This factor is used to convert thermal performance calculations for non-circular profiles to a conventional circular channel profile to simplify the DED manufacturing process for non-circular IM cooling channels.
Abstract
Cultivated strawberry (Fragaria × ananassa) is one of our youngest domesticates, originating in early eighteenth-century Europe from spontaneous hybrids between wild allo-octoploid species ...(Fragaria chiloensis and Fragaria virginiana). The improvement of horticultural traits by 300 years of breeding has enabled the global expansion of strawberry production. Here, we describe the genomic history of strawberry domestication from the earliest hybrids to modern cultivars. We observed a significant increase in heterozygosity among interspecific hybrids and a decrease in heterozygosity among domesticated descendants of those hybrids. Selective sweeps were found across the genome in early and modern phases of domestication—59–76% of the selectively swept genes originated in the three less dominant ancestral subgenomes. Contrary to the tenet that genetic diversity is limited in cultivated strawberry, we found that the octoploid species harbor massive allelic diversity and that F. × ananassa harbors as much allelic diversity as either wild founder. We identified 41.8 M subgenome-specific DNA variants among resequenced wild and domesticated individuals. Strikingly, 98% of common alleles and 73% of total alleles were shared between wild and domesticated populations. Moreover, genome-wide estimates of nucleotide diversity were virtually identical in F. chiloensis,F. virginiana, and F. × ananassa (π = 0.0059–0.0060). We found, however, that nucleotide diversity and heterozygosity were significantly lower in modern F. × ananassa populations that have experienced significant genetic gains and have produced numerous agriculturally important cultivars.
The bacterial artificial chromosome (BAC) cloning system is capable of stably propagating large, complex DNA inserts in Escherichia coli. As part of the Mycobacterium tuberculosis H37Rv genome ...sequencing project, a BAC library was constructed in the pBeloBAC11 vector and used for genome mapping, confirmation of sequence assembly, and sequencing. The library contains about 5,000 BAC clones, with inserts ranging in size from 25 to 104 kb, representing theoretically a 70-fold coverage of the M. tuberculosis genome (4.4 Mb). A total of 840 sequences from the T7 and SP6 termini of 420 BACs were determined and compared to those of a partial genomic database. These sequences showed excellent correlation between the estimated sizes and positions of the BAC clones and the sizes and positions of previously sequenced cosmids and the resulting contigs. Many BAC clones represent linking clones between sequenced cosmids, allowing full coverage of the H37Rv chromosome, and they are now being shotgun sequenced in the framework of the H37Rv sequencing project. Also, no chimeric, deleted, or rearranged BAC clones were detected, which was of major importance for the correct mapping and assembly of the H37Rv sequence. The minimal overlapping set contains 68 unique BAC clones and spans the whole H37Rv chromosome with the exception of a single gap of approximately 150 kb. As a postgenomic application, the canonical BAC set was used in a comparative study to reveal chromosomal polymorphisms between M. tuberculosis, M. bovis, and M. bovis BCG Pasteur, and a novel 12.7-kb segment present in M. tuberculosis but absent from M. bovis and M. bovis BCG was characterized. This region contains a set of genes whose products show low similarity to proteins involved in polysaccharide biosynthesis. The H37Rv BAC library therefore provides us with a powerful tool both for the generation and confirmation of sequence data as well as for comparative genomics and other postgenomic applications. It represents a major resource for present and future M. tuberculosis research projects.
We compare the results of two techniques used to calculate the evolution of cooling gas during galaxy formation: smooth particle hydrodynamics (SPH) simulations and semi-analytic modelling. We ...improve upon the earlier statistical comparison of Benson et al. by taking halo merger histories from the dark matter component of the SPH simulation, which allows us to compare the evolution of galaxies on an object-by-object basis in the two treatments. We use a ‘stripped-down’ version of the semi-analytic model described by Helly et al. that includes only shock heating and radiative cooling of gas and which is adjusted to mimic the resolution and other parameters of a comparison SPH simulation as closely as possible. We compare the total mass of gas that cools in haloes of different mass as a function of redshift and the masses and spatial distribution of individual ‘galaxies’. At a redshift of z = 0, the cooled gas mass in well-resolved haloes agrees remarkably well (to better than ∼20 per cent) in the SPH simulation and stripped-down semi-analytic model. At high redshift, resolution effects in the simulation become increasingly important and, as a result, more gas tends to cool in low-mass haloes in the SPH simulation than in the semi-analytic model. The cold gas mass function of individual galaxies in the two treatments at z = 0 also agrees very well and, when the effects of mergers are accounted for, the masses of individual galaxies and their two-point correlation functions are also in excellent agreement in the two treatments. Thus, our comparison confirms and extends the earlier conclusion of Benson et al. that SPH simulations and semi-analytic models give consistent results for the evolution of cooling galactic gas.
The posterior interhemispheric approach can be useful in accessing a wide range of lesions in the falcotentorial region. We demonstrate the case of a 59-year-old woman with a long history of headache ...who was found to have a large falcotentorial meningioma on imaging workup. The deep venous structures of the Galenic complex were displaced inferiorly by the tumor, thus indicating a supratentorial approach. Risks and alternatives to the approach demonstrated in this video were discussed with the patient, and she wished to proceed. The patient was positioned in a three-quarters prone (“park bench”) position in order to allow gravity retraction of the right hemisphere, which facilitated tumor visualization. The tumor was removed completely, and the patient tolerated the procedure well without complication. Patient consent was obtained for the use of the operative video. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.
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