New experimental methods are developed to measure the uniaxial power-law creep parameters α and n in the relation ε̇=ασn (ε̇ is the creep strain rate and σ is the creep stress) from indentation data ...obtained with a conical or pyramidal indenter. The methods are based on an analysis of Bower et al., which relates the indentation creep rate to the uniaxial creep parameters based on simple assumptions about the constitutive behavior (Bower et al., 1993). Using finite element simulations to establish the influences of finite indenter geometry and transients caused by elasticity, the proposed methods are explored experimentally using amorphous selenium as a model material. This material is well suited for the study because it creeps at temperatures slightly above ambient in a load-history independent fashion with a stress exponent close to unity. Indentation creep tests were conducted with a Berkovich indenter using three different loading methods. With a few notable exceptions, the values of both α and n derived from the indentation data are generally in good agreement with those measured in uniaxial compression tests, thus demonstrating the validity of the approach.
► Uniaxial and indentation creep in amorphous selenium are examined experimentally. ► Several different methods for obtaining and analyzing creep data are examined. ► Bower's analysis correctly predicts the behavior under certain conditions. ► Full field finite element simulations are used to account for finite deformation. ► Influences of elasticity on the creep behavior are documented.
To assess the utility of osteoporosis screening using abdominal computed tomography (CT) versus dual-energy X-ray absorptiometry (DXA) T-scores as the reference.
Patients ≥30 years undergoing ...abdominal CT and DXA within 12 months were assessed retrospectively. Bone mineral density (BMD) was measured using axial CT attenuation at L1, correlating with DXA T-scores. Sensitivity, specificity, area under the curve (AUC), and odds ratio (OR) were calculated.
The study cohort comprised 407 CT–DXA pairs (58.2% women). The prevalence of osteoporosis was 11.8%. L1 density and T-score were significantly correlated in both women (r=0.35, p<0.001) and men (r=0.15, p=0.04). The AUC to distinguish osteoporosis from osteopenia and normal BMD was 0.64 (95% CI: 0.56–0.71). In women, a threshold of 190 HU detected T-scores ≤ –2.5 with a negative predictive value (NPV) of 94.4% (OR=4.4, p<0.01). In the entire cohort, a threshold of 180 HU detected T-scores ≤ –2.5 with a NPV of 96.2% (OR=4.7, p<0.01).
CT L1 attenuation correlates with L1 DXA T-scores. Density values < 190 and 180 HU increased the probability of an osteoporosis diagnosis in Australian women and the overall cohort, respectively. Opportunistic screening for osteoporosis using abdominal CT is feasible, enabling identification of at-risk subjects for formal DXA imaging, thereby improving treatment initiation and reducing fracture risk.
•CT L1 density correlates with L1 DXA T-scores.•> 180 HU threshold ruled out osteoporosis/moderate osteopenia with high certainty.•> 190 HU (females) decreased the probability of osteoporosis/moderate osteopaenia.•Screening for osteoporosis using abdominal CT is feasible.•At-risk patients can be identified for formal DXA imaging.
Since its introduction to North America in 1999, West Nile virus (WNV) has had devastating impacts on native host populations, but to date these impacts have been difficult to measure. Using a ...continental-scale dataset comprised of a quarter-million birds captured over nearly two decades and a recently developed model of WNV risk, we estimated the impact of this emergent disease on the survival of avian populations. We find that populations were negatively affected by WNV in 23 of the 49 species studied (47%). We distinguished two groups of species: those for which WNV negatively impacted survival only during initial spread of the disease (n= 11), and those that show no signs of recovery since disease introduction (n= 12). Results provide a novel example of the taxonomic breadth and persistent impacts of this wildlife disease on a continental scale. Phylogenetic analyses further identify groups (New World sparrows, finches, and vireos) disproportionally affected by temporary or persistent WNV effects, suggesting an evolutionary dimension of disease risk. Identifying the factors affecting the persistence of a disease across host species is critical to mitigating its effects, particularly in a world marked by rapid anthropogenic change.
To report the technical success, complications and long-term outcomes of patients with intrahepatic cholelithiasis not amenable to endoscopic retrograde cholangiopancreatography (ERCP) who were ...treated with percutaneous transhepatic biliary Laser lithotripsy (PTBLL).
A retrospective review of 12 patients who underwent PTBLL for intrahepatic cholelithiasis was performed. There were 5 men and 7 women with a mean age of 46±18 (SD) years (range: 23-75 years). PTBLL was performed when stone clearance using ERCP had previously failed or was not appropriate due to unfavourable anatomy or the presence of multiple stones or a large stone. Percutaneous biliary access into intrahepatic ducts was obtained if not already present and lithotripsy was performed using a HolmiumYAG 2100nM Laser. Patients files were analyzed to determine the technical success, complications and long-term outcomes.
Eleven patients (11/12; 92%) had a history of previous hepatobiliary surgery and nine (9/12; 75%) had multiple stones confirmed on preprocedure imaging. A 100% success rate in fragmenting the target stone(s) was achieved and 11/12 patients (92%) had successful first pass extraction of target stone fragments. Two patients (2/12; 17%) required repeat lithotripsy. One patient (1/12; 8%) experienced a major complication in the form of cholangitis. Of patients with long-term follow-up, 4/10 (40%) had recurrence of intrahepatic calculi with a mean time interval of 31 months (range 3-84 months).
For patients with intrahepatic biliary calculi not amenable to ERCP, PTBLL provides an effective and safe alternate treatment.
Behavioural responses to reduce predation risk might cause demographic ‘costs of fear’. Costs differ among species, but a conceptual framework to understand this variation is lacking. We use a ...life‐history framework to tie together diverse traits and life stages to better understand interspecific variation in responses and costs. We used natural and experimental variation in predation risk to test phenotypic responses and associated demographic costs for 10 songbird species. Responses such as increased parental attentiveness yielded reduced development time and created benefits such as reduced predation probability. Yet, responses to increased risk also created demographic costs by reducing offspring production in the absence of direct predation. This cost of fear varied widely across species, but predictably with the probability of repeat breeding. Use of a life‐history framework can aid our understanding of potential demographic costs from predation, both from responses to perceived risk and from direct predation mortality.
As the quality and quantity of patient-centered care may be perceived differently by recipients and independent observers, assessment of humanization of pediatric care remains an elusive issue. ...Herein we aim to analyze differences between the degrees of verified existing vs. perceived humanization issues of a pediatric ward. Furthermore, we examine whether there is concurrence between the degrees of humanization perceived by users (parents/visitors) vs. staff members.
The study was conducted in the pediatric wards of seven medical centers of the Campania region (Italy) categorized as general (n = 4), children's (n = 1), and university (n = 2) hospitals. The degree of existing humanization was assessed by a multidisciplinary focus group for each hospital through a pediatric care-oriented checklist specifically developed to individuate the most critical areas (i.e., those with scores < 2.5). The degree of perceived humanization was assessed through four indicators: well-being, social aspects, safety and security, and health promotion.
The focus groups showed that critical areas common to all centers were mainly concerned with welfare, mediation, translation, and interpretation services. Specific critical issues were care and organizational processes oriented to the respect and specificity of the person and care of the relationship with the patient. Perceived humanization questionnaires revealed a lack of recreational facilities and mediation and translation services. As for specific features investigated by both tools, it was found that mediation and interpretation services were lacking in all facilities while patient perceptions and observer ratings for space, comfort, and orientation concurred only in the general hospital evaluations.
Future humanization interventions to ensure child- and family-friendly hospital care call for careful preliminary assessments, tailored to each pediatric ward category, which should consider possible differences between perceived and verified characteristics.
Abstract
One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to ...conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure.
Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how mycorrhizal associations correlate with the latitudinal tree beta-diversity ...remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test how AM and EcM trees contribute to total beta-diversity and its components (turnover and nestedness) of all trees. We find AM rather than EcM trees predominantly contribute to decreasing total beta-diversity and turnover and increasing nestedness with increasing latitude, probably because wide distributions of EcM trees do not generate strong compositional differences among localities. Environmental variables, especially temperature and precipitation, are strongly correlated with beta-diversity patterns for both AM trees and all trees rather than EcM trees. Results support our hypotheses that latitudinal beta-diversity patterns and environmental effects on these patterns are highly dependent on mycorrhizal types. Our findings highlight the importance of AM-dominated forests for conserving global forest biodiversity.
This report describes a patient who presented with acute but transient right arm weakness and altered sensation secondary to severe stenosis of the left common carotid artery (CCA) origin. ...Endovascular stenting of the stenosed origin was achieved utilising a novel rendezvous technique through combined retrograde common carotid artery and anterograde transfemoral approaches. This technique has numerous potential advantages over traditional transfemoral endovascular and open retrograde common carotid artery approaches. It allows increased procedural control and success in traversing the stenosis and provides a smooth transition for the stent delivery catheter. An open cutdown procedure or open surgical technique is not required. Our patient recovered well from the procedure with no complications within the three-month follow up period.
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