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En France, la filière bois énergie génère annuellement des centaines de milliers de tonnes de cendres de biomasse. Du fait de leurs caractéristiques, les cendres sous-foyer (CSF) de biomasse pourraient être potentiellement valorisables dans les matériaux de construction. Cela permettrait d’avoir un nouveau débouché à ces déchets industriels, tout en diminuant la consommation de granulats naturels non renouvelables qui se raréfient. Ces travaux de recherche étudient le potentiel des CSF de biomasse en tant que substitut des granulats naturels dans des matériaux cimentaires. La première partie de cette étude s’intéresse aux caractéristiques physico-chimiques des CSF afin d’évaluer leur compatibilité avec la matrice cimentaire. Dans ce cadre, une analyse des modifications induites par la combustion de biomasse sur le sable de chaudière (SC) utilisé lors du processus de combustion est proposée. La surface des grains de CSF a été modifiée par la fusion de la biomasse avec le grain de SC, ce qui influence les propriétés physico-chimiques des CSF. L’incorporation de CSF en tant que sable dans la composition de mortier diminue leur consistance tout en améliorant leur propriété mécanique. La quantité de chaleur dégagée augmente également et les porosités diminuent avec l’ajout de CSF dans les mortiers., Academic Journal of Civil Engineering, Vol 40 No 2 (2022): Special Issue - NoMaD 2022

International audience

When formulating cementitious composites with plant particles, the cement setting may be disrupted by the compounds extracted from the plant. An experimental programme is proposed to analyse the in...

International audience; In this work, wood–cement composites (WCC) based on poplar sawdust were developed and fabricated by the extrusion process. The volume fraction of wood particles in the mixes was varied from 23% to 46%. The mechanical properties of these WCC were characterized in compression to determine the maximum compressive strength and the Young’s modulus. In the second part, these Young’s modulus values were estimated in compression using a 3D numerical homogenization which takes into account the variability in wood particle lengths and the random distribution in the mixes. The obtained results show a good agreement between the experimental data and numerical calculations up to a 35% volume fraction. The model’s poor estimation for large volume fractions (over 35%) could be attributed to the experimental sample size, which is not representative for large volume fractions, the percolation of the wood particles into the mixes and the inhibition of the cement setting.

The primary concern for plant-fiber-reinforced cementitious composites is the durability of fibers in the highly alkaline cement matrix . This paper presents a way to improve the durability of these composites through partial or total replacement of the ordinary Portland cement by alternative binders such as metakaolin (MK), ground granulated blast-furnace slag (GGBS) or calcium sulfo-aluminate cement (CSA). The fresh-state and the mechanical properties (3-point bending and compressive tests) were investigated after 7, 28, 90 and 320 days. In the hardened state, alternative binders slow down the development of the compressive strength , especially for short-term curing period. However, after 90 days, alternative binders allow to reach strengths equivalent to OPC-based mortars. In addition, alternative binders can delay the plant fiber degradation between 28 and 90 days. In the long term (320 days), CSA and metakaolin allow to maintain a significant toughness, which is an essential criterion for fiber-reinforced concretes. Thermal analyzes and pH measurements have identified the causes of degradation of flax fibers and those that explain the improvement in the durability of composites.

In recent years, many studies have focused on the mix-design and characterization of cementitious composites reinforced with plant fibres. It appears that in the fresh state, the morphology and the hydrophilic nature of these fibres significantly affect the rheology of the material. In the hardened state, the mechanical performances of the composites are lower than that of composites reinforced with standard fibres (glass, synthetic, etc.). These poor mechanical performances are mainly due to weak neo-formed fibre/matrix interface. Indeed, the high-water absorption capacity causes swelling/shrinkage of the fibre within the matrix, which subsequently generates an unbounded interface. In order to address these issues, numerous studies have been carried out over the past few years on compatibilisation treatments applied to plant fibres. In most cases, these are chemical treatments to leach the fibre, which often have a significant environmental impact. This work examines the influence of a coating treatment with linseed oil applied to flax fibres on the properties of cementitious composites. The first part of this study deals with the optimisation of this treatment. The second part focuses on the effect of this treatment on the properties of the composite in the fresh and hardened states. The results showed a noticeable improvement in the workability of the treated fibre composites. The linseed oil coating treatment can also significantly improve the flexural strength of the composite, depending on the mix-design. Flax fibres and linseed oil can also slightly enhance the thermal insulation properties of the material.

Alfa plants are endemic to the Maghreb, where they cover great areas and are of prime socio-economic interest. This study investigated use of the alfa plant in a fibre-reinforced cement composite for facade panels. Alfa fibres were ground in a knife mill, sieved through a 2 mm sieve and added to the mixture in different addition ratios (1, 2 and 3 vol%). The results showed that the incorporation of ground alfa fibres did not significantly influence the fresh properties of the mortar. Compared with a control mortar, there was a decrease of 4% in the workability of the mortar reinforced with 2 vol% of alfa fibres. An enhancement in flexural strength was observed for all three addition ratios, with the evolution of flexural strength linearly related to the increase of the fibre addition ratio. However, the compressive strength of the composites decreased with the addition of fibres, mainly due to the high porosity inside the matrix. This was confirmed by a capillary test, which showed that a high addition ratio led to high water absorption by capillary motion.

In the aim of enhancing the reuse potential of poplar sawdust stemming from the transformation of wood into particleboard for woodworking purposes, wood-reinforced concrete mix designs are optimised to obtain composites in compliance with French standard NF EN 771-3/CN. Two criteria are assessed herein for structural elements, namely dimensional tolerance and mechanical strength (7-day levels above 6 MPa). Wood aggregates are introduced by means of a volumetric substitution for sand. Easily demoldable concrete blocks have been produced by means of vibrocompaction. A high vibration frequency is coupled with a compaction process in order to generate semi-dry cylindrical concrete blocks (100 mm in diameter, 200 mm high). The addition of wood into the cementitious composite exerts a noticeable influence on its workability, as well as on its thermophysical and mechanical behaviour. Wood alters how the cementitious composite is hydrated and has an impact on its mechanical strength in compression, which drops considerably with an increase in sawdust content. A 50% rate of substituting poplar sawdust for sand was chosen for testing purposes. This concrete composition actually yields mechanical strength values similar to that of the reference concrete used to manufacture masonry blocks.

An experimental investigation was undertaken to evaluate the potential use of poplar by-products in cement mortars. Two by-products from poplar processing were studied: sawdust (from sawing wood) and milled fibres (from wood waste obtained during cutting). Poplar fibres and sawdust were incorporated into mortars as sand volume substitution with rates ranging from 0 to 100%. Before introduction into the mortar, poplar aggregates were characterized (morphology and water absorption). It appeared that these wood aggregates absorb very quickly a large amount of water (up to 200%). The introduction of these poplar by-products has significant effects on the composite properties in both fresh and hardened states. It was noted that the workability of the mixtures with the poplar wood varies with the substitution rate. The inhibition of cement setting with poplar sawdust is characterized by maturity tests and affects the mechanical properties of mortars. In addition, increasing the poplar aggregates content causes a continuous increase of the material porosity, which leads to a decrease in density. Besides, it appears that the incorporation of poplar aggregates into mortars also decrease their thermal conductivities, which would help to reduce building heat losses. A significant decrease in the mechanical properties of poplar-based mortars was also noted, related to the rate of fibres or sawdust introduced into mixtures. The hydration disturbances, the high internal porosity of the wood particles and their low density can explain these lower mechanical strengths. However, despite these disturbances, the valorisation of poplar wood by-products remains possible in cementitious materials for the manufacture of concrete masonry blocks.

The Alfa plant is indigenous and spans a large zone throughout North Africa. Recently, Alfa plant has been used in building materials, notably as a reinforcement. This study aims to valorize the Alfa plant into fiber-reinforced mortar based on a cement-glass composite mix design. Two Alfa fiber morphologies are considered herein: different cutting lengths (10, 20 and 30 mm), and ground using a knife mill (shorter than 2 mm). These fibers were added to mortars at various volume ratios: 1, 2 and 3%. The workability and density of these distinct formulations were then measured in their fresh state. In comparison with the control mortar (CM), the introduction of Alfa fibers (either cut or ground), with ratios below 2% vol., leads to a slight decrease in mixture workability. However, Alfa fibers do not significantly alter the fresh material density. It was recorded a delay in setting time of the composites as a function of fiber addition rate. In the hardened state, an improvement in flexural strength is noticed for mortars reinforced with 1% vol. of fibers compared to the CM. However, results show that the increase in either type of fiber (cut or ground) generates a decrease in compressive strength compared to the CM. This outcome can be confirmed by both the decrease in heat released during the hydration reaction and water-accessible porosity inside the matrix.

Research on the economic and human toll of natural disasters focuses on the short-term, often ignoring the important long-term impacts of these catastrophic events. The main reason for the lack of empirical research on the long-term is the inherent and unavoidable difficulty in identifying any long-term impacts and attributing them to the disaster. On the 23rd of May 1960, a devastating tsunami struck the city of Hilo on the island of Hawaii. Remarkably, there was no significant injury or damage elsewhere in the Hawaiian Islands. This tsunami provides a unique natural experiment as the tsunami was unexpected, and the other Hawaiian Islands, which were not hit by the tsunami, provide an ideal control group that enables us to precisely identify the counter-factual. We use a newly developed synthetic control methodology formalized in Abadie et al. (2010) to measure the long-term impacts of the tsunami. We find that while wages did not decline noticeably, population and employment trends shifted. Fifteen years after the event, unemployment was still 32% higher and population was still 9% lower than it would have been had the tsunami not occurred. We also find a corresponding decrease in the number of employers and sugar production in the county.

In recent years, numerous studies focused on the development of sustainable cement-based binders through the use of supplementary cementitious materials such slag, fly ash, metakaolin, silica fume, pozzolan, etc. The use of wood biomass for power generation is increasingly common which lead to an important amount of waste produced in the combustion process such as fly ash, which must be transported to landfills for deposition, or used as sludge in farming. Depending on their chemical and physical characteristics, wood biomass fly ashes could be reuse in blended cements as supplementary cementitious material. Different sources of biomass fly ashes have been selected to evaluate their potential for use as a cement replacement. Their chemical and mineralogical compositions, as well as their morphology were first evaluated via X-ray and laser diffraction (XRD), inductively coupled plasma (ICP) and scanning electron microscopy (SEM coupled with energy-dispersive X-ray spectroscopy (EDX). Fly ashes showed variable physicochemical characteristics but some present interesting compositions for the intended use. One fly ash present a high content of CaO and minors of SiO2 and Al2O3. The chemical composition does not allow to categorize this fly ash as a pozzolan material but it may have a latent hydraulic behaviour, which could be interesting as cement substitution. This fly ash has been incorporated into a cement paste by progressive replacement of Portland cement (from 0 to 70%). It has been observed that biomass fly ash has a higher water demand compared to Portland cement. This additional water demand was evaluated by the Vicat consistency test and by an evaporometry method. The setting time and kinetic hydration of the biomass fly ash pastes were also assessed with the standardized Vicat test and by isothermal calorimetry.

An experimental investigation was undertaken to evaluate the potential use of poplar by-products in cement mortars. Two by-products from poplar processing were studied: sawdust (from sawing wood) and milled fiber (from wood waste obtained during cutting). The fibers and sawdust were incorporated into the mortars as a sand substitution with rates from 10 to 100%. The introduction of these poplar by-products has a significant on the composite properties in both fresh and hardened state. It was noted that the workability of the mixtures with the poplar wood varies with the substitution rate. Moreover, the increase in the amount of fibers or sawdust causes a continuous increase in the porosity of the material, which leads to a decrease in density. A significant decrease in the mechanical properties of bio-sourced mortars was noted, again related to the rate of fibers or sawdust introduced in mixtures. The high internal porosity of the wood particles and their low density can explain these lower mechanical strengths.

Tropical forests provide a suite of benefits including biodiversity, cultural value, and a range of ecosystem services. Globally, there is increasing interest in incentivizing native forest protection as a multi-benefit natural infrastructure strategy to secure clean and ample water supplies. In addition to conversion to agriculture and other non-forest land uses, non-native species invasion represents a major threat to these systems, particularly on islands. Whereas several recent efforts have quantified the benefits of reforestation or avoided agricultural expansion in tropical forest areas, the hydrologic and associated economic benefits of avoided invasion have received less attention. To address this gap, we quantified the benefits of protecting native forest from conversion to non-native forest in East Maui, Hawai'i in terms of groundwater recharge, a highly valued hydrologic ecosystem service that water utilities increasingly seek to co-finance. Compared with two counterfactual invasion scenarios, the groundwater recharge benefits of planned conservation activities reached 40.9 to 146.3 million cubic meters over 100 years depending on invasion rate assumptions. This translated to 2.70 to 137.6 million dollars of cost savings to the water utility in present value terms (achieved through reducing reliance on more expensive water alternatives) under a range of discount rates and water scarcity assumptions. Our results suggest that investing in native forest conservation provides an important hydrologic ecosystem service benefit that complements the range of benefits provided by these ecosystems. These findings demonstrate that co-financing native forest conservation represents an important supply side option in water resources planning.

International audience; An experimental investigation was undertaken on the influence of different surface treatments of flax fibres on mortar properties in both fresh and hardened states. Three types of coating were explored for surface modification atmospheric-pressure plasma, mineral coating made of a grout of cement and ground granulated blast-furnace slag, and polymer coating based on linseed oil. Water absorption tests were performed to evaluate the performance of the coatings. Water absorption kinetics and/or water retention capacity were drastically modified by the plasma treatment at atmospheric-pressure and by the linseed oil treatment. The workability of the pastes incorporating fibres coated with the cement grout or linseed oil was greatly improved compared to the raw fibres. The presence of fibres significantly increases the rate of entrapped air, which seems to depend on the nature of the coating. In the hardened state, regardless of the nature of the fibre coating, the flexural strength increases beyond 90 days of curing. Up to 320 days of curing, the compressive strengths of the different composites are similar to that of the control mortar, except for the composite with linseed oil coated-fibres which proves to be the most porous. The presence of flax fibres also enhances the mortar toughness and prevent from desiccation cracking. Nevertheless, none of the treatments experimented in this work makes it possible to preserve the beneficial effects of fibres on the mechanical behaviour of composites in the long term. © 2018 Elsevier Ltd

Scaffolds with tunable mechanical and topological properties fabricated by templated-fused deposition modeling promote increased osteogenic differentiation of bone marrow stem cells with increasing substrate modulus and decreasing pore size. These findings guide the rational design of cell-responsive scaffolds that recapitulate the bone microenvironment for repair of bone damaged by trauma or disease.

Captive-taking is an extensive international and domestic problem that faces law enforcement, as well as the military and intelligence communities. To date, a modicum of research has been done to understand these offenders and the methods they employ in the commission of their crimes. Understanding the tactics, techniques, and procedures that perpetrators use to execute a captive-taking event will better prepare law enforcement agencies and others to prevent, mitigate, respond to, and recover from captive-taking incidents. The current research is drawn from a pilot study consisting of interviews of seven captive-takers. Consensual qualitative analysis was utilized to draw conclusions from the interview transcripts about the modus operandi of these perpetrators. Sixty-one domains of M.O. were yielded, grouped into 35 core ideas, and cross analyzed with weighted labels identifying the frequency each particular domain/core idea arose. The results presented are unique because they are derived directly from the perspective of the captive-takers themselves and the data were gathered using a systematic methodological approach (Perpetrator-Motive Research Design). Limitations, strengths and future research directions are also discussed.

An experimental investigation was conducted in order to study the properties of a hybrid hemp-flax composite material in term of capillary water absorption, mechanical strength, thermal conductivity and shrinkage. The hemp-flax composite material is made with 90% hemp shives and 10% flax fibers. Hemp aggregates have a high water absorption capacity, which led to a reduction of the hemp concrete mechanical performances. Four mixes were made for: shuttered walls, external coating, floor insulation and roof insulation. Firstly, bio-based aggregates were characterized in term of particle size distribution and water absorption. Then, the compressive strength of these four mixes was determined to compare the mechanical behavior of the hybrid composite material with hemp concrete. The capillary absorption and the total shrinkage of these bio-based materials were also measured. Finally, we measured the thermal conductivity coefficient of these materials. The results of the compressive strength show a significant improvement due to the incorporation of flax fibers. Flax fibers improve the compactness of the material, thus increasing its density, which leads to a greater mechanical strength. It was observed that the capillary absorption of hemp concrete seems to be related to the aggregates/paste ratio. Finally, flax fibers have reduced hempcrete shrinkage of about 15%.

Background Residual acetabular dysplasia is one of the most common complications after treatment for developmental dysplasia of the hip. The acetabular growth response after reduction of a dislocated hip varies. The options are to wait and add a redirectional osteotomy as a secondary procedure at an older age, or to perform a primary acetabuloplasty at the time of the open reduction to stimulate acetabular development. We present the early results of such a procedure—open reduction and an incomplete periacetabular acetabuloplasty—as a one-stop procedure for developmental dysplasia of the hip. Patients and methods We retrospectively reviewed the results obtained with 55 hips (in 48 patients, 43 of them girls) treated between September 2004 and February 2011. This cohort included late presentations and failures of nonoperative treatment and excluded unsuccessful previous surgical treatment (including closed reductions), neuromuscular disease, and other teratological conditions. Patients were treated once the ossific nucleus was present or when they reached one year of age. 31 cases were late presentations while 17 represented failures of nonoperative treatment. The mean age of the patients at surgery was 1.3 (0.6–2.6) years. The mean follow-up period was 4 (2–8) years. According to the IHDI classification, 1 was grade I, 9 were grade II, 13 were grade III, and 32 were grade IV. Results The mean acetabular index fell from 38 (23–49) preoperatively to 21 (10–27) at the last follow-up. There were no infections, nerve palsies, or graft extrusions. None of the cases required secondary surgery for residual acetabular dysplasia. 8 patients developed avascular necrosis (AVN) of grade II or more. The incidence of AVN was significantly associated with previous, failed nonoperative treatment. 1 patient developed coxa magna requiring shelf arthroplasty 4 years after the index procedure and 1 patient with lateral growth arrest required medial screw epiphysiodesis. Interpretation This incomplete periacetabular acetabuloplasty is a reliable adjunct to open reductions, and it is followed by a rapid acetabular growth response that avoids secondary pelvic procedures. It is a one-stop surgery with predictable outcome that can be performed in 0.5- to 2.5-year-old children.

Background Residual acetabular dysplasia is one of the most common complications after treatment for developmental dysplasia of the hip. The acetabular growth response after reduction of a dislocated hip varies. The options are to wait and add a redirectional osteotomy as a secondary procedure at an older age, or to perform a primary acetabuloplasty at the time of the open reduction to stimulate acetabular development. We present the early results of such a procedure—open reduction and an incomplete periacetabular acetabuloplasty—as a one-stop procedure for developmental dysplasia of the hip. Patients and methods We retrospectively reviewed the results obtained with 55 hips (in 48 patients, 43 of them girls) treated between September 2004 and February 2011. This cohort included late presentations and failures of nonoperative treatment and excluded unsuccessful previous surgical treatment (including closed reductions), neuromuscular disease, and other teratological conditions. Patients were treated once th...

International audience

Injectable and settable biomaterials are a growing class of therapeutic technologies within the field of regenerative medicine. These materials offer advantages compared to prefabricated implants because of their ability to be utilized as part of noninvasive surgical procedures, fill complex defect shapes, cure in situ, and incorporate cells and other active biologics. However, there are significant technical barriers to clinical translation of injectable and settable biomaterials, such as achieving clinically relevant handling properties and benign reaction conditions. This review focuses on the engineering challenges associated with the design and development of injectable and chemically settable polymeric biomaterials. Additionally, specific examples of the diverse chemistries utilized to overcome these challenges are covered. The future translation of injectable and settable biomaterials is anticipated to improve patient outcomes for a number of clinical conditions.

Circulating monocytes undergo spontaneous apoptosis when there is no activation stimulus, which is critical to population control for proper host response to implants. As activation and apoptosis of monocytes/macrophages are regulated by cell-cell and cell-matrix interactions, their regulatory mechanism was investigated in this study using polyethylene glycol (PEG)-containing polyurethane films in which PEG-rich and polyester-rich domains were phase separated. Human blood monocyte-derived macrophages (HBMs) preferentially adhered to PEG domains (cell-matrix interaction) due to the low molecular weight (600 g mol⁻¹), resulting in increased HBM density (cell-cell interaction). As both cell-cell and cell-matrix interactions were promoted, HBM apoptosis increased, while their activation as measured by phagocytosis, intracellular reactive oxygen species (ROS) level and matrix metalloproteinase-9 production decreased compared to PEG-free films. When cell seeding density and cell-adhesive gelatin coating on silicone films were controlled, a cooperative role of cell-matrix (adhesion) and cell-cell (density) interactions in inducing HBM apoptosis was observed. Expression of the macrophage adhesion molecule CD11b caused apoptosis in this context, which was mediated by tissue necrosis factor-α signaling but down-regulated by the ROS inhibitor diphenylene iodonium and the anti-inflammatory peptide Ac-SDKP, suggesting a new concept for the design of biomaterials that allows for cell adhesion without excessive inflammatory activation.

This paper is a summary of my thesis work at the Massachusetts Institute of Technology (MIT). It explores design options for naval vessels and provides a framework for analyzing their benefit to the Navy. Future demands on Navy warships, such as new or changing missions and capabilities, are unknowns at the time of the ship's design. Therefore, ships often require costly engineering changes throughout their service life. These are expensive both fiscally – because the Navy pays for engineering and installation work – and operationally – because either a warship cannot carry out a desired mission need or is carrying out a mission for which it was not initially designed. One method of addressing uncertainty in capital assets is imbedding flexibilities in their architecture. The paper offers early stage design suggestions on flexibilities for naval platforms to incorporate preplanned repeats of the platform with new or different missions. A conceptual platform created – the SCAMP – includes each of these suggestions in its architecture. Then, the paper summarizes an analysis framework similar to real options to evaluate the value of including these expansion options in early stage design versus traditional design methods and their products. The analysis uses a version of the MIT Cost Model for early stage ship design to determine acquisition and life cycle costs. The model was modified to support this analysis by allowing a simulation of possible mission changes with their severity distributed stochastically over a realistic time horizon. Subsequently, the model calculates these effects on life cycle cost. The most important result is the value of the framework for evaluating these managerial options. This framework can be extended to the subsystem level or to the system-of-systems level. In this application, the model predicts that, on average, a flexible platform should not only cost less to build, but also reduce modernization costs by 9% per ship over its life cycle. Therefore, counter-intuitively, building a lesscapable ship with the flexibility to expand capabilities or switch missions actually provides greater expected utility during its service life.

Although schools are among the safest places for children and youth, they are the occasional site of violent behavior. One form of violence is the barricaded-hostage event. In this article, the authors review the research literature pertaining to these events. Specifically, studies examining the impact on direct and indirect victims, and responders to these events, are presented and critiqued. Recommendations for future research are also made, followed by a summary and conclusions.

Phosphatidyl choline (PC)-based materials have been found to be resistant to nonspecific protein adhesion in vitro. In this study, a PC-based planar supported phospholipid bilayer composed of 1,2-bis[10-(2',4'-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphocholine (bis-SorbPC or BSPC) was generated on piranha-treated silicon wafers by vesicle deposition. The bilayer was polymerized with redox initiation forming a stable 4-nm thick coating. Polymerized lipid bilayers (PLBs) were characterized and tested for uniformity, with ellipsometry and contact angle. Cellular adhesion and morphological changes in RAW 264.7 macrophages were investigated in vitro on PLBs and compared to bare silicon controls. Fluorescent and scanning electron microscopy were used to observe changes in cellular morphology. The PLBs showed much lower cellular adhesion than bare silicon controls. Of the cells that attached to the PLBs, a very low percentage showed the same morphological expressions seen on the controls. It is hypothesized that proteins adsorb to the defects in the PLBs, caused by incomplete polymerization, and this mediates the observed minimal cellular attachment and morphological changes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: , 2011.

The contents of this data in brief are related to the article titled “Matrix Rigidity Regulates the Transition of Tumor Cells to a Bone-Destructive Phenotype through Integrin β3 and TGF-β Receptor Type II”. In this DIB we will present our supplemental data investigating Integrin expression, attachment of cells to various adhesion molecules, and changes in gene expression in multiple cancer cell lines. Since the interactions of Integrins with adsorbed matrix proteins are thought to affect the ability of cancer cells to interact with their underlying substrates, we examined the expression of Integrin β1, β3, and β5 in response to matrix rigidity. We found that only Iβ3 increased with increasing substrate modulus. While it was shown that fibronectin greatly affects the expression of tumor-produced factors associated with bone destruction (parathyroid hormone-related protein, PTHrP, and Gli2), poly-l-lysine, vitronectin and type I collagen were also analyzed as potential matrix proteins. Each of the proteins was independently adsorbed on both rigid and compliant polyurethane films which were subsequently used to culture cancer cells. Poly-l-lysine, vitronectin and type I collagen all had negligible effects on PTHrP or Gli2 expression, but fibronectin was shown to have a dose dependent effect. Finally, altering the expression of Iβ3 demonstrated that it is required for tumor cells to respond to the rigidity of the matrix, but does not affect other cell growth or viability. Together these data support the data presented in our manuscript to show that the rigidity of bone drives Integrinβ3/TGF-β crosstalk, leading to increased expression of Gli2 and PTHrP.

Cancer patients frequently develop skeletal metastases that significantly impact quality of life. Since bone metastases remain incurable, a clearer understanding of molecular mechanisms regulating skeletal metastases is required to develop new therapeutics that block establishment of tumors in bone. While many studies have suggested that the microenvironment contributes to bone metastases, the factors mediating tumors to progress from a quiescent to a bone-destructive state remain unclear. In this study, we hypothesized that the “soil” of the bone microenvironment, specifically the rigid mineralized extracellular matrix, stimulates the transition of the tumor cells to a bone-destructive phenotype. To test this hypothesis, we synthesized 2D polyurethane (PUR) films with elastic moduli ranging from the basement membrane (70 MPa) to cortical bone (3800 MPa) and measured expression of genes associated with mechanotransduction and bone metastases. We found that expression of Integrin b 3( Ib3), as well as tumor-produced factors associated with bone destruction (Gli2 and parathyroid hormone related protein (PTHrP)), significantly increased with matrix rigidity, and that blocking Ib3 reduced Gli2 and PTHrP expression. To identify the mechanism by which Ib3 regulates Gli2 and PTHrP (both are also known to be regulated by TGF-b), we performed F€ resonance energy transfer (FRET) and immunoprecipitation, which indicated that Ib3 co-localized with TGF-b Receptor Type II (TGF-b RII) on rigid but not compliant films. Finally, transplantation of tumor cells expressing Ib3 shRNA into the tibiae of athymic nude mice significantly reduced PTHrP and Gli2 expression, as well as bone destruction, suggesting a crucial role for tumor-produced Ib3 in disease progression. This study demonstrates that the rigid mineralized bone matrix can alter gene expression and bone destruction in an Ib3/TGF-b-dependent manner, and suggests that Ib3 inhibitors are a potential therapeutic approach for blocking tumor transition to a bone destructive phenotype. Published by Elsevier Ltd.

Every time a rampage school shooting occurs, the importance of school safety reemerges as a national (and international) priority. As time goes by, the media lose interest and the policymakers move on to other pressing issues. However, the problem does not go away. Fortunately, in the USA, it appears that the issue has risen to the level of congressional intervention with a recent commitment of roughly $ 15 million for research (it is called the Comprehensive School Safety Initiative). The ultimate aim is to conduct the research and evaluation that will enhance school safety throughout the USA.

Olweus (1993) defined bullying as aggressive behavior that is repeated, intentional, and typically involves a disparity in power between the bully and the victim. Daniels et al. (2007) suggested that school violence, including bullying, could have harmful effects on the individual, school environment, and the surrounding community. The Youth Risk Behavior Surveillance report (2012) found that 20.1 % of the students had been bullied on school property in the 12 months preceding their involvement in the survey—an alarming prevalence rate indicating the importance of this topic in our American school systems today.