High-Impact Mechanical Loading Increases Bone Material Strength in Postmenopausal Women-A 3-Month Intervention Study.

Bone adapts to loading in several ways, including redistributing bone mass and altered geometry and microarchitecture. Because of previous methodological limitations, it is not known how the bone material strength is affected by mechanical loading in humans. The aim of this study was to investigate the effect of a 3-month unilateral high-impact exercise program on bone material properties and microarchitecture in healthy postmenopausal women. A total of 20 healthy and inactive postmenopausal women (aged 55.6 ± 2.3 years [mean ± SD]) were included and asked to perform an exercise program of daily one-legged jumps (with incremental number, from 3×10 to 4×20 jumps/d) during 3 months. All participants were asked to register their performed jumps in a structured daily diary. The participants chose one leg as the intervention leg and the other leg was used as control. The operators were blinded to the participant's choice of leg for intervention. The predefined primary outcome was change in bone material strength index (BMSi), measured at the mid tibia with a handheld reference probe indentation instrument (OsteoProbe). Bone microstructure, geometry, and density were measured with high-resolution peripheral quantitative computed tomography (XtremeCT) at the ultradistal and at 14% of the tibia bone length (distal). Differences were analyzed by related samples Wilcoxon signed rank test. The overall compliance to the jumping program was 93.6%. Relative to the control leg, BMSi of the intervention leg increased 7% or 0.89 SD (p = 0.046), but no differences were found for any of the XtremeCT-derived bone parameters. In conclusion, a unilateral high-impact loading program increased BMSi in postmenopausal women rapidly without affecting bone microstructure, geometry, or density, indicating that intense mechanical loading has the ability to rapidly improve bone material properties before changes in bone mass or structure. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc

A new and efficient approach to time-dependent density-functional perturbation theory for optical spectroscopy

Using a super-operator formulation of linearized time-dependent density-functional theory, the dynamical polarizability of a system of interacting electrons is given a matrix continued-fraction representation whose coefficients can be obtained from the non-symmetric block-Lanczos method. The resulting algorithm allows for the calculation of the {\em full spectrum} of a system with a computational workload which is only a few times larger than that needed for {\em static} polarizabilities within time-independent density-functional perturbation theory. The method is demonstrated with the calculation of the spectrum of benzene, and prospects for its application to the large-scale calculation of optical spectra are discussed.Comment: 4 pages, 2 figure

Ability of tropical forest soils of French Guiana and Reunion to depollute woods impregnated with biocides

Our study sought to fine-tune knowledge about those microorganisms, particularly wood-decaying fungi degrading pollutants in situ. With a view to the depollution or bioremediation of treated woods, wood-decaying microorganisms from tropical forest soils in French Guiana and the island of Reunion were assessed for their ability to degrade toxic biocides such as pentachlorophenol (PCP) or copper chromium arsenic compounds (CCA). The degradation of red pine (Pinus resinosa) test pieces was monitored and it was found that the soil from French Guiana was more efficient than the soil from Reunion in terms of microbial activity in relation to these two biocides. A significant difference in weight loss was found for the red pinetest pieces treated with CCA and PCP, varying in a ratio of one to two (18% and 30%, respectively). In addition, a study of wood and soil fungus communities using D-HPLC and CE-SSCP, then analysed by a PCA, showed that biocide products leached into the soil had an impact on the fungus communities, which differed depending on the sampling time and on the wood treatment. Lastly, these results confirmed that CCA was less leachable and less degradable by microorganisms in these soils than PCP. (Résumé d'auteur

The Impact of Arsenic on Protein Homeostasis and Aggregation in Saccharomyces cerevisiae

Arsenic and cadmium are two toxic heavy metals that occur naturally in bedrock. Arsenic is found in high concentrations in certain areas and can contaminate groundwater, leading to exposure through drinking water and crop irrigation for the local population. Cadmium is primarily dispersed in the environment with fertilizers and as a byproduct of the electronics industry, and it is absorbed by the body through food and cigarette smoke. Long-term exposure to these heavy metals is associated with cardiovascular diseases, cancer, diabetes and neurodegenerative diseases. One of the primary reasons for their toxicity is their ability to interact with proteins in cells, essential for normal cellular function. This leads to protein misfolding and aggregation, and disruption of cellular processes. We used the yeast Saccharomyces cerevisiae to better understand how these toxic substances affect cells. The first article demonstrates how yeast cells mobilize specific control pathways to varying degrees to manage protein homeostasis and eliminate arsenic stress. The second article focuses on the roles of chaperones and ubiquitin ligases in maintaining protein balance under arsenic stress. We show that the ubiquitin-proteasome pathway is the major player in preventing and eliminating arsenite-induced protein aggregates. The third article shows that arsenite and cadmium alter the formation and structure of alpha-synuclein amyloid fibers, as well as cause changes in the protein's cellular localization. The final study provides a proteome-wide analysis of arsenic-binding proteins and demonstrates that nuclear transport is a direct target of arsenite-induced proteotoxicity. Together, these studies offer a comprehensive insight into the mechanisms by which arsenite disrupts protein homeostasis - from interactions with proteins to aggregate management mechanisms. This dissertation aims to deepen our understanding of cellular responses to heavy metal exposure, hopefully with implications for future therapeutic strategies against metal-related diseases

A study of hydroelastic fluid-structure interaction with application to immersed cantilevers

This study presents an approach for partitioned fluid-structure interaction (FSI) applied to large structural deformations, where an incompressible turbulent solver is combined with a structural solver. The implementation is based upon two different open-source libraries by using MPI as a parallel communication protocol, the packages deal.II and OpenFOAM. FSI is achieved through a strongly-coupled scheme. The solver has been validated against cases with a submerged cantilever in a channel flow to which experiments, numerical calculations and theoretical solutions are available. The verification of the procedure is performed by using a solid-solid interaction (SSI) study.The solver has proven to be robust and has the same parallel efficiency as the fluid and the solid solver stand-alone

Optical excitations in organic molecules, clusters and defects studied by first-principles Green's function methods

Spectroscopic and optical properties of nanosystems and point defects are discussed within the framework of Green's function methods. We use an approach based on evaluating the self-energy in the so-called GW approximation and solving the Bethe-Salpeter equation in the space of single-particle transitions. Plasmon-pole models or numerical energy integration, which have been used in most of the previous GW calculations, are not used. Fourier transforms of the dielectric function are also avoided. This approach is applied to benzene, naphthalene, passivated silicon clusters (containing more than one hundred atoms), and the F center in LiCl. In the latter, excitonic effects and the $1s \to 2p$ defect line are identified in the energy-resolved dielectric function. We also compare optical spectra obtained by solving the Bethe-Salpeter equation and by using time-dependent density functional theory in the local, adiabatic approximation. From this comparison, we conclude that both methods give similar predictions for optical excitations in benzene and naphthalene, but they differ in the spectra of small silicon clusters. As cluster size increases, both methods predict very low cross section for photoabsorption in the optical and near ultra-violet ranges. For the larger clusters, the computed cross section shows a slow increase as function of photon frequency. Ionization potentials and electron affinities of molecules and clusters are also calculated.Comment: 9 figures, 5 tables, to appear in Phys. Rev. B, 200

FRAX-based intervention and assessment thresholds for osteoporosis in Iran

A Summary We compared the utility of the current Iranian guidelines that recommend treatment in women with a T-score <= - 2.5 SD with a FRAX-based intervention threshold equivalent to women of average BMI with a prior fragility fracture. Whereas the FRAX-based intervention threshold identified women at high fracture probability, the T-score threshold was less sensitive, and the associated fracture risk decreased markedly with age. Introduction The fracture risk assessment algorithm FRAX (R) has been recently calibrated for Iran, but guidance is needed on how to apply fracture probabilities to clinical practice. Methods The age-specific ten-year probabilities of a major osteoporotic fracture were calculated in women with average BMI to determine fracture probabilities at two potential intervention thresholds. The first comprised the age-specific fracture probabilities associated with a femoral neck T-score of -2.5 SD, in line with current guidelines in Iran. The second approach determined age-specific fracture probabilities that were equivalent to a woman with a prior fragility fracture, without BMD. The parsimonious use of BMD was additionally explored by the computation of upper and lower assessment thresholds for BMD testing. Results When a BMD T-score <= - 2.5 SD was used as an intervention threshold, FRAX probabilities in women aged 50 years was approximately two-fold higher than in women of the same age but with an average BMD and no risk factors. The relative increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80 years or more, a T-score of -2.5 SD was actually protective. The 10-year probability of a major osteoporotic fracture by age, equivalent to women with a previous fracture rose with age from 4.9% at the age of 50 years to 17%, at the age of 80 years, and identified women at increased risk at all ages. Conclusion Intervention thresholds based on BMD alone do not effectively target women at high fracture risk, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a "fracture threshold" target women at high fracture risk

Children who screen positive for language delay but not autism: from 2.5 to 6 years of age

Background: Language disorders (LDs) are prevalent, affecting approximately 10% of children. Among them, 7.5% have developmental language disorder (DLD), while 2.5% have LD associated with a known medical condition. In Sweden, nearly all children undergo language screening through the Child Health Services (CHS) between 2.5 and 3 years of age. In Gothenburg, autism screening is also conducted at 2.5 years. Aim: To clinically describe and longitudinally follow the language and neurodevelopmental trajectories of children referred to the Paediatric Speech and Language Pathology Clinic (SLP Clinic) after screening positive for language problems but not for autism at the 2.5-year screening at CHS. Methods: In 2016, at a mean age of 2.9 years, 100 mono- or multilingual children, referred to the SLP Clinic, participated in a language assessment. Parents completed a newly developed questionnaire (2-5) concerning their child’s development (motor, language, memory, attention, impulsivity, learning, social skills and behaviour). At age 6 years, 85 of the 100 children participated in a follow-up language assessment. Parents completed questionnaires about child development (same areas as at 2.9 years) and parents and children reported on child quality of life (QoL). A review of paediatric records was conducted after the SLP assessment with a view to obtain information about language interventions and other possible diagnoses. Results: At 2.9 years, 87 children met DLD criteria and parent-reported concerns were mainly related to the child's language, communication and social skills. At age 6 years, 68 children had diagnosis of DLD, 6 had speech sound disorder, and 11 had no language disorder diagnosis. Half of the parents of children with DLD reported concerns about child development, predominantly related to language, but some also reported other concerns e.g. about executive functions. Parents reported no impaired QoL, although some of the children themselves reported challenges in school and social functioning. At both 2.9 years and 6 years, the multilingual children in the DLD group performed significantly worse than the monolingual children on the language tests, except for the phonological and non-verbal tasks at 6 years of age. The review of paediatric records revealed that families only participated in half of the offered intervention sessions. Monolingual families participated to a greater extent in the introduction of alternative and augmentative communication (pictural support). In agreement with the family, the SLP completed contact with monolingual families at a significantly higher rate than multilingual ones. Out of the 85 6-year-old children, 20 had received an additional ESSENCE diagnosis (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations), 5 of whom had autism. Conclusion: DLD was found to be persistent in both monolingual and multilingual children, with multilingual children having greater language difficulties already at 2.9 years based on the test results. At age 6 years, some children perceived their QoL as partially impaired, which was not confirmed by their parents. The presence of additional neurodevelopmental diagnoses at age 6, underscores the need for follow-up of these children using a holistic ESSENCE perspective

Exploration of Different Production Flow Setups in Manufacturing Facilities Evaluating Production Scenarios for SKFs Roller Production

This thesis investigates the optimization of production systems at SKF, a global leader in the manufacturing of bearings, focusing specifically on roller manufacturing in Gothenburg, Sweden. Given the rapid advancements in industrial manufacturing SKF seeks to increase the efficiency of their roller production. This study assesses two contrasting production scenarios, Simplified Flow and Flexible Flow, to determine which aligns best with SKF’s strategic objectives and the inherent challenges of the production environment. The primary aim is to evaluate these systems against key performance indicators, ultimately aiding SKF in refining its production processes. Research Questions (RQ): 1. What does the current situation look like for roller manufacturing at SKF? This question seeks to describe the baseline operations and existing challenges within SKF’s roller production. A VSM was conducted to answer RQ1. 2. What problem areas can be identified connected to the current situation? This focuses on pinpointing specific issues that could be addressed by changes in the production system. RQ2 was answered by identifying problem areas derived from interviews, observations, and the VSM where 6 problem areas were identified. 3. What are the main differences between the two proposed production scenarios and how do they manage the identified problem areas? This question compares the two production scenarios in detail, examining how each manages the identified problem areas. The Simplified Flow focuses on flow efficiency whilst Flexible Flow focuses on resource efficiency. 4. Which of the two proposed production scenarios for SRB rollers is most suitable for SKF? The final question aims to conclude which production scenario best fits the strategic and operational goals of SKF. RQ4, by combining the results from an MCDA analysis and how the respective scenario manages the identified problems, resulted in a recommendation to implement, and move toward the Simplified Flow along with aspects taken from the Flexible Flow. This research utilizes a mixed-method approach, incorporating both qualitative and quantitative data from interviews, observations, and internal documents. Through analysis framed by a literature review in production systems, this study contributes to the decision-making process at SKF and extends practical implications for the broader field of industrial manufacturing