Abstract
Two new species of Thermosbaenacea are described from various locations in southern France. One species is Limnosbaena occidentalis n. sp., a species that has been known since 1967 and has ...long been awaiting a formal description, the other is Tethysbaena exigua n. sp., a very small species that represents a new species-group within the genus and has more morphological affinities with the Caribbean Tethysbaena sanctaecrucis species-group than with any other group. Furthermore, some considerations about the origin and ecology of these species are given. Three species distributed over the families of Halosbaenidae and Monodellidae are now known in France within a radius of 80 km around Marseille, one of which has also been identified in the alluvial aquifer of the Dordogne river.
Dentin is a biocomposite possessing elegant hierarchical structure, which allows it to resist fracture effectively. Despite the considerable efforts to unravel the peculiar fracture behavior of ...dentin, the effect of microstructural features on the fracture process is largely unknown. In this study, we explore the interaction between the primary crack with crack tip located in intertubular dentin (ITD) and microcracking of peritubular dentin (PTD) ahead of the primary crack. A micromechanical model accounting for the unique composite structure of dentin is developed, and computational simulations are performed. It is found that the microcracking of PTD located in the crack plane in front of the primary crack tip can promote the propagation of the primary crack, increasing the propensity of coalescence of primary crack and microcracks nucleating in PTD. We show that the two-layer microstructure of dentin enables reduction in driving force of primary crack, potentially enhancing fracture toughness. The high stiffness of PTD plays a critical role in reducing the driving force of primary crack and activating microcracking of PTD. It is further identified that the microcracking of PTD arranged parallel to the crack plane with an offset could contribute to the shielding of primary crack.
Abstract Recapitulation of the cellular microenvironment of the heart, which promotes cell contraction, remains a key challenge in cardiac tissue engineering. We report here on our work, where for ...the first time, a 3-dimensional (3D) spring-like fiber scaffold was fabricated, successfully mimicking the coiled perimysial fibers of the heart. We hypothesized that since in vivo straightening and re-coiling of these fibers allow stretching and contraction of the myocardium in the direction of the cardiomyocytes, such a scaffold can support the assembly of a functional cardiac tissue capable of generating a strong contraction force. In this study, the mechanical properties of both spring-like single fibers and 3D scaffolds composed of them were investigated. The measurements showed that they have increased elasticity and extensibility compared to corresponding straight fibers and straight fiber scaffolds. We have also shown that cardiac cells cultivated on single spring-like fibers formed cell–fiber interactions that induced fiber stretching in the direction of contraction. Moreover, cardiac cells engineered within 3D thick spring-like fiber scaffolds formed a functional tissue exhibiting significantly improved function, including stronger contraction force ( p = 0.002), higher beating rate ( p < 0.0001) and lower excitation threshold ( p = 0.02), compared to straight fiber scaffolds. Collectively, our results suggest that spring-like fibers can play a key role in contributing to the ex vivo formation of a contracting cardiac muscle tissue. We envision that cardiac tissues engineered within these spring-like fiber scaffolds can be used to improve heart function after infarction.
Clinical trials demonstrated that women treated for breast cancer with anthracycline or trastuzumab are at increased risk for heart failure and/or cardiomyopathy (HF/CM), but the generalizability of ...these findings is unknown. We estimated real-world adjuvant anthracycline and trastuzumab use and their associations with incident HF/CM.
We conducted a population-based, retrospective cohort study of 12,500 women diagnosed with incident, invasive breast cancer from January 1, 1999 through December 31, 2007, at eight integrated Cancer Research Network health systems. Using administrative procedure and pharmacy codes, we identified anthracycline, trastuzumab, and other chemotherapy use. We identified incident HF/CM following chemotherapy initiation and assessed risk of HF/CM with time-varying chemotherapy exposures vs no chemotherapy. Multivariable Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment for age at diagnosis, stage, Cancer Research Network site, year of diagnosis, radiation therapy, and comorbidities.
Among 12 500 women (mean age = 60 years, range = 22-99 years), 29.6% received anthracycline alone, 0.9% received trastuzumab alone, 3.5% received anthracycline plus trastuzumab, 19.5% received other chemotherapy, and 46.5% received no chemotherapy. Anthracycline and trastuzumab recipients were younger, with fewer comorbidities than recipients of other chemotherapy or none. Compared with no chemotherapy, the risk of HF/CM was higher in patients treated with anthracycline alone (adjusted HR = 1.40, 95% CI = 1.11 to 1.76), although the increased risk was similar to other chemotherapy (adjusted HR = 1.49, 95% CI = 1.25 to 1.77); the risk was highly increased in patients treated with trastuzumab alone (adjusted HR = 4.12, 95% CI = 2.30 to 7.42) or anthracycline plus trastuzumab (adjusted HR = 7.19, 95% CI = 5.00 to 10.35).
Anthracycline and trastuzumab were primarily used in younger, healthier women and associated with increased HF/CM risk compared with no chemotherapy. This population-based observational study complements findings from clinical trials on cancer treatment safety.
Over the past 25 years, IRIS has become an integral resource in materials laboratories around the world, bringing together stimulating communities of rheology experimentalists and theoreticians, ...rheological experts, and experts from other fields, and even making rheology accessible to non-rheologists. The calculational tools of IRIS interface data from different experimental findings with predictions from rheology theories. Since its beginning, many theory groups used IRIS to share their original codes for rheology predictions. We demonstrate this in two examples, (1) the detailed analysis of small amplitude oscillatory shear data (SAOS) and predictions thereof and (2) a theory, newly implemented in IRIS, that elegantly unites dynamical quantities from small amplitude oscillatory shear (SAOS) with data from filament stretching rheometry and predictions of transient shear. IRIS supports this convergence with a standardizing data (Dealy et al., J Rheol 39:253-265,
1995
), which makes data sharing easy and independent of instrument brand-specific and laboratory-specific coding.
This article contains examples to demonstrate the use of different design concepts for cylindrical shells under axial compression. The examples are based on shells which were manufactured according ...to electroplating, machining, welding (isotropic cylinders) and prepreg hand layup on a mandrel (composite cylinders). Three of the four shell series are characterized by pure elastic buckling and one shell series buckled in the elastic-plastic region. All relevant data for the numerical analysis are described in the article and summarized in the Elsevier repository of this article (geometry, material, measured imperfection data and Python-ABAQUS scripts).
The design concepts are based on the geometric imperfection signatures, probabilistic and deterministic lower-bound methods. The design concepts are representative for the development of design approaches for imperfection sensitive shells from the early 1980 to the late 2010 and are validated with experimental data. Recently developed design lower-bound curves for axially loaded cylinders are presented and compared with currently used design criteria like the Eurocode EN 1993-1-6 and the NASA SP-8007. The results of this article show that the design of imperfection sensitive cylinders has been significantly improved in the last 30 years.
•Collection of 660 experimental knockdown factors for cylinders under axial compression.•Isotropic and composite cylinders analyzed with probabilistic and deterministic lower-bound methods.•All design examples for cylindrical shells under axial compression are validated with experimental data.•Geometric imperfection data for finite element analysis (ABAQUS) deposited in the Elsevier repository.
There have been considerable efforts to understand, predict, and reduce suicide among U.S. military veterans. Studies have shown that posttraumatic stress disorder (PTSD), major depression (MDD), and ...traumatic brain injury (TBI) increase risk of suicidal behavior in veterans. Limited research has examined anger and social support as factors linked to suicidal ideation, which if demonstrated could lead to new, effective strategies for suicide risk assessment and prevention. Iraq/Afghanistan era veterans (N = 2467) were evaluated in the ongoing Veterans Affairs Mid-Atlantic Mental Illness Research, Education and Clinical Center (MIRECC) multi-site Study of Post-Deployment Mental Health on demographic and psychological variables. Analyses revealed that suicidal ideation in veterans was positively associated with anger and negatively associated with social support. These results remained significant in multivariate logistic regression models controlling for relevant variables including PTSD, MDD, and TBI. Examining interrelationships among these variables, the analyses revealed that the association between PTSD and suicidal ideation was no longer statistically significant once anger was entered in the regression models. Further, it was found that TBI was associated with suicidal ideation in veterans with MDD but not in veterans without MDD. These findings provide preliminary evidence that suicide risk assessment in military veterans should include clinical consideration of the roles of anger and social support in addition to PTSD, MDD, and TBI. Further, the results suggest that suicide prevention may benefit from anger management interventions as well as interventions aimed at bolstering social and family support as treatment adjuncts to lower suicide risk in veterans.
The aim of this study was to analyze the changing patterns of Listeria monocytogenes contamination in a cheese processing facility manufacturing a wide range of ready-to-eat products. ...Characterization of L. monocytogenes isolates included genotyping by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Disinfectant-susceptibility tests and the assessment of L. monocytogenes survival in fresh cheese were also conducted. During the sampling period between 2010 and 2013, a total of 1284 environmental samples were investigated. Overall occurrence rates of Listeria spp. and L. monocytogenes were 21.9% and 19.5%, respectively. Identical L. monocytogenes genotypes were found in the food processing environment (FPE), raw materials and in products. Interventions after the sampling events changed contamination scenarios substantially. The high diversity of globally, widely distributed L. monocytogenes genotypes was reduced by identifying the major sources of contamination. Although susceptible to a broad range of disinfectants and cleaners, one dominant L. monocytogenes sequence type (ST) 5 could not be eradicated from drains and floors. Significantly, intense humidity and steam could be observed in all rooms and water residues were visible on floors due to increased cleaning strategies. This could explain the high L. monocytogenes contamination of the FPE (drains, shoes and floors) throughout the study (15.8%). The outcome of a challenge experiment in fresh cheese showed that L. monocytogenes could survive after 14days of storage at insufficient cooling temperatures (8 and 16°C). All efforts to reduce L. monocytogenes environmental contamination eventually led to a transition from dynamic to stable contamination scenarios. Consequently, implementation of systematic environmental monitoring via in-house systems should either aim for total avoidance of FPE colonization, or emphasize a first reduction of L. monocytogenes to sites where contamination of the processed product is unlikely. Drying of surfaces after cleaning is highly recommended to facilitate the L. monocytogenes eradication.
•The occurrence rate of L. monocytogenes in a contaminated cheese plant was 19.5%.•The high diversity of L. monocytogenes genotypes was reduced after interventions.•One dominant sequence type (ST) 5 could not be eradicated from drains and floors.•Systematic L. monocytogenes environmental monitoring improves intervention strategies.
Thin-walled cylindrical shells are primary structures in aerospace, marine and civil engineering. A major loading scenario for these imperfection sensitive shells is axial compression. For this load ...case, there is a critical disagreement between the theoretical and experimental critical load. This difference is mainly contributed due to shape deviations of the shell middle plane which are commonly described as geometric imperfections. However, some deviations between theoretical and experimental buckling loads are sometimes so severe that other imperfection types are possibly to blame.
This article describes experimental and numerical studies on the influence of loading imperfections on the buckling load of thin-walled cylinders. A global loading imperfection was applied by mistake during a buckling test of a thin-walled cylinder which led to a severe buckling load reduction and the corresponding load level was similar to the post-buckling load. Also, a series of experimental studies with localized loading imperfections is described which significantly reduced the buckling load of CFRP cylinders.
The experimental results of this article represent an example for some of the very low buckling knockdown factors from early experimental campaigns and give insights in how to avoid these critical imperfections in experimental buckling campaigns.
•Experimental buckling studies on cylinder under axial compression with different loading imperfections.•Global loading imperfection leads to an extreme reduction of the buckling load.•Local loading imperfections lead to a lower-bound of the buckling load.•Numerical and experimental test structures are described in detail.
Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates ...of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations.
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