Damage analysis and fracture toughness evaluation in a thin woven composite laminate under static tension using infrared thermography

This work deals with the issue of damage growth in thin woven composite laminates subjected to tensile loading. The conducted tensile tests were monitored on-line with an infrared camera, and tested specimens were analysed using Scanning Electron Microscopy (SEM). Combined with SEM micrographs, observation of heat source fields enabled us to assess the damage sequence. Transverse weft cracking was confirmed to be the main damage mode and fiber breakage was the final damage leading to failure. For cracks which induce little variation of specimen stiffness, the classic “Compliance method” could not be used to compute energy release rate. Hence, we present here a new procedure based on the estimation of heat source fields to calculate the energy release rate associated with transverse weft cracking. The results are then compared to those computed with a simple 3D inverse model of the heat diffusion problem and those presented in the literature

Remote control of a robotic hand using a leap sensor

This paper presents a low-cost gesture-based remote control of a ro-botic hand. The proposed control architecture is based on a commercial leap motion sensor and an Arduino board, which have been chosen due to their low-cost and user-friendly features. A specific Matlab code has been implemented to collect data from the leap motion sensor and to generate proper instructions to control a robotic hand, which has been 3D print at Sheffield Hallam Univer-sity. Experimental tests have been carried out validate the effectiveness of the proposed remote control for performing various grasping tasks

A Robust Solution Procedure for Hyperelastic Solids with Large Boundary Deformation

Compressible Mooney-Rivlin theory has been used to model hyperelastic solids, such as rubber and porous polymers, and more recently for the modeling of soft tissues for biomedical tissues, undergoing large elastic deformations. We propose a solution procedure for Lagrangian finite element discretization of a static nonlinear compressible Mooney-Rivlin hyperelastic solid. We consider the case in which the boundary condition is a large prescribed deformation, so that mesh tangling becomes an obstacle for straightforward algorithms. Our solution procedure involves a largely geometric procedure to untangle the mesh: solution of a sequence of linear systems to obtain initial guesses for interior nodal positions for which no element is inverted. After the mesh is untangled, we take Newton iterations to converge to a mechanical equilibrium. The Newton iterations are safeguarded by a line search similar to one used in optimization. Our computational results indicate that the algorithm is up to 70 times faster than a straightforward Newton continuation procedure and is also more robust (i.e., able to tolerate much larger deformations). For a few extremely large deformations, the deformed mesh could only be computed through the use of an expensive Newton continuation method while using a tight convergence tolerance and taking very small steps.Comment: Revision of earlier version of paper. Submitted for publication in Engineering with Computers on 9 September 2010. Accepted for publication on 20 May 2011. Published online 11 June 2011. The final publication is available at http://www.springerlink.co

Effect of Forest Site Preparation and Livestock Grazing on Stormflow and Water Quality in the South East

The commercial forestlands of East Texas and Louisiana are the most water-efficient producing areas of the two states. Current and projected water shortages for Texas makes this water-rich area extremely important to future growth and development of Texas. However, little is known about the influence of intensive forest practices or livestock grazing on water quality, yield or site productivity in Texas. This is the only instrumented watershed study in Texas or Louisiana that is currently evaluating the influence of livestock grazing on water and the second study evaluating the impact of intensive forest practices on water. This research is providing information that will enable forest managers, state and federal agencies to select livestock grazing and/or forest management practices that will maintain a productive forest environment and minimize off-site water quality impacts. It is imperative that if Texas in the next 30 years is: 1) to help meet the timber product demand that is projected to be placed on the Southeast, and 2) to meet the projected water shortages we need to understand the impact of intensive forest and livestock grazing practices on site productivity and water. This research is helping provide the basic information needed to manage Southeast forestlands for timber products, red meat and water. The southern states are currently producing half of the nation's wood supply with large demands to increase timber production expected in the next 20 years. The challenge facing forestry in the South is in developing technology and management to meet this increased demand and maintain an acceptable forest environment in the face of increased taxes, rising labor, equipment and energy costs. The intensive forest management practices of harvesting and site preparation have been identified as causing potential declines in site production and as sources of nonpoint pollution. The Clean Water Act (PL 92-500 and PL 95-217) requires identification and control of silvicultural activities and livestock grazing which contribute to nonpoint source pollution. Implementation of "best management practices", either voluntary or mandatory, are the suggested means for maintaining water quality and site productivity. Hydrologic impacts of livestock grazing result primarily from the interactions of climate, vegetation, soil, and intensity and duration of livestock use. Thus, grazing impacts will vary naturally from area to area due to the normal variability of these factors. Few studies have attempted to account for these natural variations. Documentation of the intensity and duration of livestock grazing has been poor or completely ignored in most studies. In East Texas, the impact of livestock grazing on water quality has had no research effort. Most research regarding the impact of grazing upon water quality has been conducted outside the Southern Region and, more importantly, outside of the Gulf Coastal Plains. Because geology, soils , topography, climate, etc. are different, extensions of that research to the East Texas and Louisiana areas may be misleading

Class I histone deacetylases 1, 2 and 3 are highly expressed in renal cell cancer

Background Enhanced activity of histone deacetylases (HDAC) is associated with more aggressive tumour behaviour and tumour progression in various solid tumours. The over-expression of these proteins and their known functions in malignant neoplasms has led to the development of HDAC inhibitors (HDI) as new anti-neoplastic drugs. However, little is known about HDAC expression in renal cell cancer. Methods We investigated the expression of HDAC 1, 2 and 3 in 106 renal cell carcinomas and corresponding normal renal tissue by immunohistochemistry on tissue micro arrays and correlated expression data with clinico-pathological parameters including patient survival. Results Almost 60% of renal cell carcinomas expressed the HDAC isoforms 1 and 2. In contrast, HDAC 3 was only detected in 13% of all renal tumours, with particular low expression rates in the clear cell subtype. HDAC 3 was significantly higher expressed in pT1/2 tumours in comparison to pT3/4 tumours. Expression of class I HDAC isoforms correlated with each other and with the proliferative activity of the tumours. We found no prognostic value of the expression of any of the HDAC isoforms in this tumour entity. Conclusion Class I HDAC isoforms 1 and 2 are highly expressed in renal cell cancer, while HDAC 3 shows low, histology dependent expression rates. These unexpected differences in the expression patterns suggests alternative regulatory mechanisms of class I HDACs in renal cell cancer and should be taken into account when trials with isoform selective HDI are being planned. Whether HDAC expression in renal cancers is predictive of responsiveness for HDI will have to be tested in further studies

Polo-like kinase 3 regulates CtIP during DNA double-strand break repair in G1

DNA double-strand breaks (DSBs) are repaired by nonhomologous end joining (NHEJ) or homologous recombination (HR). The C terminal binding protein–interacting protein (CtIP) is phosphorylated in G2 by cyclin-dependent kinases to initiate resection and promote HR. CtIP also exerts functions during NHEJ, although the mechanism phosphorylating CtIP in G1 is unknown. In this paper, we identify Plk3 (Polo-like kinase 3) as a novel DSB response factor that phosphorylates CtIP in G1 in a damage-inducible manner and impacts on various cellular processes in G1. First, Plk3 and CtIP enhance the formation of ionizing radiation-induced translocations; second, they promote large-scale genomic deletions from restriction enzyme-induced DSBs; third, they are required for resection and repair of complex DSBs; and finally, they regulate alternative NHEJ processes in Ku−/− mutants. We show that mutating CtIP at S327 or T847 to nonphosphorylatable alanine phenocopies Plk3 or CtIP loss. Plk3 binds to CtIP phosphorylated at S327 via its Polo box domains, which is necessary for robust damage-induced CtIP phosphorylation at S327 and subsequent CtIP phosphorylation at T847

The Impact of Harvesting and Site Preparation on Stormflow and Water Quality in East Texas

In 1979, nine small forested watersheds were instrumented in East Texas to determine the effect of intensive forest management practices on water quantity and quality. Three replications of three treatments were used: 1) clearcutting - followed by shearing ant windrowing, 2) clearcutting - followed by roller chopping and 3) undisturbed control. Following treatment, the sheared and windrowed sites exposed 57% of the surface soil compared to 16% for the chopped watersheds. During 1981, the first year after treatment, stormflow volumes increased with the intensity of the site disturbance. Sites sheared produced the greatest amount of stormflow (5.76 inches), followed by chopped (3.26 inches) and the undisturbed watersheds (1.03 inches). Stormflow volumes decreased 66% and 57% on the sheared and chopped watersheds the second year following treatment. Stormflow volumes in 1983 were 2.46, 1.75 and 0.84 inches for the sheared, chopped and control watersheds, respectively. Sediment losses were significantly higher on the sheared watersheds (2,620 lb/acre) than the chopped (22 lb/acre), during 1981. By the fall of 1982, the exposure of mineral soil on the sheared sites decreased to 20% and to 4% on the chopped sites. For this reason and the lower volume of runoff, sediment loss for 1982 dropped to 71.3, 4.9 and 4.5 lb/acre for the sheared, chopped and undisturbed watersheds, respectively. Sediment losses in the third year following treatment continued decreasing on the sheared sites (30.9) and remained approximately the same on the chopped and control sites. Nitrate concentrations were significantly different between treatments during 1981: Sheared - 205 ppb, chopped - 96 ppb and control ~ 10 ppb. During 1982, although nitrate concentrations were lower, the sheared watersheds still had a significantly higher concentration. Nitrate concentrations in 1983 remained low at 54, 20 and 10 ppb for the sheared, chopped and control watersheds, respectively. Total nitrogen concentration on the sheared sites was 2,155 ppb, which was significantly higher than the chopped (999 ppb) or the control sites (996 ppb) for 1981. The first year total nitrogen export from the sheared sites (2.79 lb/acre) was 3.5 times greater than the chopped loss (0.76 lb/acre) and 12 times greater than the loss on the control sites (0.24 lb/acre). The second year following treatment, total nitrogen concentrations were not significantly different and total nitrogen loss on the sheared areas was less than half of the loss recorded from the control sites during 1981. Total nitrogen loss in the third year after treatment was reduced to 0.37, 0.20 and 0.08 lb/ acre for the sheared, chopped and control treatments, respectively. Total phosphorus concentrations for 1981 were 221, 85 and 54 ppb for the sheared, chopped and control watersheds, respectively. Total phosphorus loss for this period was only 0.297 lb/acre from the sheared treatments, but was significantly higher than the chopped or undisturbed treatments. A drop in sediment concentrations and runoff in 1982 reduced phosphorus losses on the sheared watersheds by over 90%. Total phosphorus export in 1983 decreased on sheared sites (0.019 lb/acre), but increased slightly on chopped (0.011 lb/acre) and control sites (0.006 lb/acre). Calcium, potassium and sodium concentrations during 1981, were highest for the chopped treatments, while magnesium concentrations were highest on the sheared treatments. Export of these elements was greatest from the sheared sites, except for calcium, which was lost in greater quantities on the chopped sites. During 1982 there was no significant difference between treatments for Ca, Mg, K and Na concentrations. Cation concentrations and losses on the treated watersheds continued declining in the third year following treatment. Increases in stormflow and sediment and nutrient losses appear to be temporary on sheared and chopped treatments. Rapid revegetation established surface cover and reduced mineral soil exposure. As the stabilization of sites continues, treatment differences should diminish. Limiting shearing and windrowing activities to the more gentle slopes will reduce first year erosion and prevent increases in sediment and nutrient losses. Roller chopping on the other hand, appears to cause only minor changes to water yield and quality on slopes of up to 25%

Expression pattern of class I histone deacetylases in vulvar intraepithelial neoplasia and vulvar cancer: a tissue microarray study

BACKGROUND: Epigenetic regulation is an important mechanism leading to cancer initiation and promotion. Histone acetylation by histone deacetylases (HDACs) represents an important part of it. The development of HDAC inhibitors has identified the utility of HDACs as a therapeutic target. Little is known about the epigenetic regulation of vulvar intraepithelial neoplasia (VIN) and vulvar squamous cell cancer (VSCC). In this study, the expression of class I HDACs (HDAC 1, 2 and 3) was compared in a series of VIN and VSCC tissues. METHODS: A tissue micro array (TMA) with specimens from 106 patients with high-grade VIN and 59 patients with vulvar cancer was constructed. The expression of HDACs 1, 2 and 3 were analyzed with immunohistochemistry (IHC). The nuclear expression pattern was evaluated in terms of intensity and percentage of stained nuclei and was compared between vulvar preinvasive lesions and vulvar cancer. RESULTS: HDAC 2 expression was significantly higher in VIN than in VSCC (p < 0.001, Fisher's test). Also, 88.7% (n=94/106) of VIN samples and only 54.5% (n=31/57) of VSCC samples were scored at the maximum level. Conversely, HDAC 3 expression was significantly higher in VSCC (93%, 53/57) compared to VIN (73.6%, 78/106, p=0.003), whereas only a small difference in the expression of HDAC 1 was found between these two entities of vulvar neoplasia. CONCLUSIONS: These results suggest that epigenetic regulation plays a considerable role in the transformation of VIN to invasive vulvar neoplasia

Anticholinergic medications in patients admitted with cognitive impairment or falls (AMiCI). The impact of hospital admission on anticholinergic cognitive medication burden. Results of a multicentre observational study

What is known and objectiveDrugs with anticholinergic properties increase the risk of falls, delirium, chronic cognitive impairment, and mortality and counteract procholinergic medications used in the treatment of dementia. Medication review and optimisation to reduce anticholinergic burden in patients at risk is recommended by specialist bodies. Little is known how effective this review is in patients who present acutely and how often drugs with anticholinergic properties are used temporarily during an admission. The aim of the study was to describe the changes in the anticholinergic cognitive burden (ACB) in patients admitted to hospital with a diagnosis of delirium, chronic cognitive impairment or falls and to look at the temporary use of anticholinergic medications during hospital stay. MethodsThis is a multi-centre observational study that was conducted in seven different hospitals in the UK, Finland, The Netherlands and Italy. Results and discussion21.1% of patients had their ACB score reduced by a mean of 1.7%, 19.7% had their ACB increased by a mean of 1.6%, 22.8% of DAP naive patients were discharged on anticholinergic medications. There was no change in the ACB scores in 59.2% of patients. 54.1% of patients on procholinergics were taking anticholinergics. Out of the 98 medications on the ACB scale, only 56 were seen. Medications with a low individual burden were accounting for 64.9% of the total burden. Anticholinergic drugs were used temporarily during the admission in 21.9% of all patients. A higher number of DAPs used temporarily during admission was associated with a higher risk of ACB score increase on discharge (OR=1.82, 95% CI for OR: 1.36-2.45, P What is new and conclusionThere was no reduction in anticholinergic cognitive burden during the acute admissions. This was the same for all diagnostic subgroups. The anticholinergic load was predominantly caused by medications with a low individual burden. More than 1 in 5 patients not taking anticholinergics on admission were discharged on them and similar numbers saw temporary use of these medications during their admission. More than half of patients on cholinesterase-inhibitors were taking anticholinergics at the same time on admission, potentially directly counteracting their effects.Peer reviewe