bluuebunny/crossref_metadata_2025 huggingface dataset:
Hippocampal Neuroprotection by Minocycline and Epigallo‐Catechin‐3‐Gallate Against Cardiopulmonary Bypass‐Associated Injury
Authors: Salameh Aida , Einenkel Anne , Kühne Lydia , Grassl Maria , von Salisch Sandy , Kiefer Phillip , Vollroth Marcel , Dähnert Ingo , Dhein Stefan
Published: January 2015

Surgical correction of congenital cardiac malformations mostly implies the use of cardiopulmonary bypass (CPB). However, a possible negative impact of CPB on cerebral structures like the hippocampus cannot be neglected. Therefore, we investigated the effect of CPB on hippocampus CA1 and CA3 regions without or with the addition of epigallocatechin‐3‐gallate (EGCG) or minocycline. We studied 42 piglets and divided them into six experimental groups: control without or with EGCG or minocycline, CPB without or with EGCG or minocycline. The piglets underwent 90 minutes CPB and subsequently, a 120‐minute recovery and reperfusion phase. Thereafter, histology of the hippocampus was performed and the adenosine triphosphate (ATP) content was measured. Histologic evaluation revealed that CPB produced a significant peri‐cellular edema in both CA regions. Moreover, we found an increased number of cells stained with markers for hypoxia, apoptosis and nitrosative stress. Most of these alterations were significantly reduced to or near to control levels by application of EGCG or minocycline. ATP content was significantly reduced within the hippocampus after CPB. This reduction could not be antagonized by EGCG or minocycline. In conclusion, CPB had a significant negative impact on the integrity of hippocampal neural cells. This cellular damage could be significantly attenuated by addition of EGCG or minocycline.
Sedimentary and thermal evolution of the Eocene‐Oligocene mudrocks from the southwestern Thrace Basin (NE Greece)
Authors: Perri F. , Caracciolo L. , Cavalcante F. , Corrado S. , Critelli S. , Muto F. , Dominici R.
Published: January 2015

Paleothermal indicators based on clay mineral and organic matter analyses, were integrated with mudrock geochemistry and stratigraphic data to define the sedimentary evolution of the southwestern Thrace Basin during the Eocene to Oligocene. This multi‐method approach allowed us to reconstruct the burial evolution of the basin in Eocene and Oligocene times and to study the mudrock composition and relate this to their provenance and source area weathering. The studied mudrocks show similar chemical variations. The distribution of some major and trace elements for the studied samples reflect heterogeneous source areas containing both felsic to mafic rocks. In particular, the Light Rare Earth Elements/Transition elements (LREEs/TEs) ratios are very high for the Avdira and Organi samples (on the average between 1.5 and 2.2 for (La + Ce)/Cr and 3.5–8 for (La + Ce)/Ni), suggesting a felsic source(s), and very low for the Samothraki, Limnos, Paterma and Iasmos samples (on the average between 0.4 and 0.6 for (La + Ce)/Cr and 0.6–1 for (La + Ce)/Ni), suggesting a mainly basic source(s). The mineralogical composition coupled with the A‐CN‐K and A‐N‐K plots suggest a complex evolution. The clay mineral data (illite percentage in I/S and the stacking order R and the Kübler Index) coupled to vitrinite reflectance analysis indicate a high to intermediate diagenetic grade for the Middle to Upper Eocene samples (from Iasmos, Gratini, Organi, Paterma, Esimi and Samotraki sections) and a low diagenetic grade for the Upper Eocene to Oligocene samples (from Limnos and Avdira sections). These data helped in interpreting the geodynamic evolution of the studied basins where the magmatic activity plays an important role. In particular, Middle to Upper Eocene sediments show high to intermediate diagenetic grade since they are located in a portion of the basin dominated by Eocene to Oligocene magmatic activity and intrusion of granitoids, whereas, the Upper Eocene to Oligocene sediments are not involved in important magmatic activity and intrusion of granitoids and, thus, show low diagenetic grade. Furthermore, Middle to Upper Eocene sediments experienced deeper burial processes caused by lithostatic load, rather than the uppermost Eocene and Oligocene sediments, in relation of their position along the stratigraphic succession. These data suggest a burial depth of at least 3–4 km with a tectonic exhumation mainly related to the extensional phases of the Miocene age.
Predictive genetic testing in minors for Myocilin juvenile onset open angle glaucoma
Authors: Souzeau E. , Glading J. , Ridge B. , Wechsler D. , Chehade M. , Dubowsky A. , Burdon K.P. , Craig J.E.
Published: January 2015

Myocilin glaucoma is an autosomal dominant disorder leading to irreversible blindness, but early intervention can minimize vision loss and delay disease progression. The purpose of this study was to discuss the benefits of predictive genetic testing in minors for Myocilin mutations associated with childhood onset glaucoma. Three families with Myocilin mutations associated with an age of onset before 18 years and six unaffected at‐risk children were identified. Predictive genetic testing was discussed with the parents and offered for at‐risk minors. Parents opted for genetic testing in half of the cases. None carried the familial mutation. The age of disease onset in the family, the severity of the condition, and the age of the child are all factors that appear to influence the decision of the parent to test their children. Predictive genetic testing for early onset Myocilin glaucoma can facilitate early detection of disease or discharge from routine ophthalmic examinations.
Local perception of infrequent, extreme upland flash flooding: prisoners of experience?
Authors: Hopkins Jonathan , Warburton Jeff
Published: January 2015

The United Kingdom has experienced several exceptional summer flash floods in recent years and there is growing concern about the frequency of such events and the preparedness of the population. This paper uses a case study of the upper Ryedale flash flood (2005) and questionnaire and interview data to assess local perceptions of upland flash flooding. Experience of a major flash flood may not be associated with increased flood risk perception. Despite local residents’ awareness of a trend towards wetter summers and more frequent heavy rainfall, the poor maintenance of rivers was more frequently thought to be a more significant factor influencing local flood risk than climate change. Such findings have important implications for the potential success of contemporary national flood policies, which have put greater emphasis on public responsibility for responding to flooding. This study recommends, therefore, the use of fresh participatory approaches to redistribute and raise awareness of locally‐held flood knowledge.
Low serum tryptophan predicts higher mortality in cardiovascular disease
Authors: Murr Christian , Grammer Tanja B. , Kleber Marcus E. , Meinitzer Andreas , März Winfried , Fuchs Dietmar
Published: January 2015

Background

The essential amino acid tryptophan is required for protein synthesis and formation of the neurotransmitter serotonin and may exert immunoregulatory functions. An accelerated tryptophan breakdown rate is associated with inflammation and immune activation.

Materials and methods

Serum concentrations of free tryptophan, neopterin and high‐sensitivity C‐reactive protein (hsCRP) were measured in 1196 patients with coronary artery disease (CAD) derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study.

Results

Tryptophan concentrations did not differ between patients with (mean ± SD: 40·1 ± 9·8 μM) or without (42·3 ± 23·9 μM; not significant, Welch's test) angiographic CAD, but patients with CAD had higher neopterin (9·1 ± 8·2 nM) and hsCRP (9·3 ± 18·5 mg/L) concentrations compared to patients without (neopterin: 7·6 ± 4·7 nM, hsCRP: 5·8 ± 7·6 mg/L; both P < 0·0001). There existed an inverse correlation between serum tryptophan and neopterin (Spearman's rank correlation: rs = −0·273) and hsCRP (rs = −0·163; both P < 0·0001) concentrations. Median observation time was 10·5 years, and 385 patients had died, including 244 patients due to cardiovascular and 132 due to noncardiovascular causes. After adjustments for cardiovascular risk factors and other possible confounders, the hazard ratio (with 95% CI) in the first tryptophan quartile of the study population was 1·51 (1·19–1·90; P = 0·0006) for total mortality, 1·41 (1·05–1·89; P = 0·0224) for cardiovascular and 1·79 (1·20–2·67; P = 0·0042) for noncardiovascular mortalities, respectively, thus indicating a significantly higher risk of death in patients with tryptophan concentrations < 34 μM.

Conclusions

Low serum tryptophan in patients with CAD is associated with immune activation and indicates reduced life expectancy.
Role of subchondral bone remodelling in collapse of the articular surface ofThoroughbred racehorses with palmar osteochondral disease
Authors: Bani Hassan E. , Mirams M. , Ghasem‐Zadeh A. , Mackie E. J. , Whitton R. C.
Published: January 2015

Reasons for performing study

To gain a better understanding of the aetiology of articular surface collapse in horses with palmar osteochondral disease.

Objectives

To determine whether acceleration of focal bone resorption associated with reduced physical activity contributes to articular surface collapse in racehorses with palmar osteochondral disease.

Study design

Cross‐sectional study comparing metacarpal bones from horses at varying stages of race training.

Methods

Metacarpal bones from 36 racingThoroughbred horses were examined with high‐resolution peripheral quantitative computed tomography to determine the proportion of the articular surface that had collapsed and with backscattered scanning electron microscopy to quantify porosity and eroded bone surface. Racing and training histories were obtained for comparison with imaging data.

Results

In 21 cases, inward collapse of the calcified cartilage layer was observed on backscattered scanning electron microscopy. An increased extent of articular surface collapse was associated with greater numbers of microfractures in the calcified cartilage and superficial subchondral bone (Spearman's correlation [rs] = 0.62, P<0.001). In the deeper bone (6–10 mm), porosity was lower with a greater extent of articular surface collapse (rs= ‐0.38, P = 0.023), whereas in the superficial bone (0–4 mm) there was no association between articular surface collapse and porosity (rs= 0.19, P = 0.26). Both porosity (median 14, range 3.8–26 vs. 3.8, 1.6–17%, P = 0.008) and eroded surface (1.1, 0.74–4.5 vs. 0.64, 0.11–4.7 mm−1, P = 0.016) of the superficial subchondral bone were higher in resting than in training horses, and in some resting horses subchondral bone voids were highly concentrated, resulting in an apparent loss of support for the overlying calcified cartilage layer.

Conclusions

Articular surface collapse is common in cases of palmar osteochondral disease and is likely to be a sequel to fatigue injury of subchondral bone. Focal subchondral bone resorption appears to contribute to collapse of the calcified cartilage and is potentiated by a reduced‐intensity exercise regimen.
Leprosy: diagnosis and management in a developed setting
Authors: Turner D. , McGuinness S. , Leder K.
Published: January 2015

Leprosy remains an important global health concern, but little has been published about its diagnosis and management in developed settings. It has been postulated that delay in diagnosis is common in developed settings. We reviewed all the cases of leprosy seen at a major tertiary referral centre between 1999 and 2013 and demonstrated that delay in diagnosis is common, especially when patients present with symptoms of leprosy reactions rather than classical symptoms, such as hypo‐pigmented hypo‐aesthetic skin lesions and neuropathy.
Natural products as photoprotection
Authors: Saewan Nisakorn , Jimtaisong Ampa
Published: January 2015

The rise in solar ultraviolet radiation on the earth's surface has led to a depletion of stratospheric ozone over recent decades, thus accelerating the need to protect human skin against the harmful effects of UV radiation such as erythema, edema, hyperpigmentation, photoaging, and skin cancer. There are many different ways to protect skin against UV radiation's harmful effects. The most popular way to reduce the amount of UV radiation penetrating the skin is topical application of sunscreen products that contain UV absorbing or reflecting active molecules. Based on their protection mechanism, the active molecules in sunscreens are broadly divided into inorganic and organic agents. Inorganic sunscreens reflect and scatter UV and visible radiation, while organic sunscreens absorb UV radiation and then re‐emit energy as heat or light. These synthetic molecules have limited concentration according to regulation concern. Several natural compounds with UV absorption property have been used to substitute for or to reduce the quantity of synthetic sunscreen agents. In addition to UV absorption property, most natural compounds were found to act as antioxidants, anti‐inflammatory, and immunomodulatory agents, which provide further protection against the damaging effects of UV radiation exposure. Compounds derived from natural sources have gained considerable attention for use in sunscreen products and have bolstered the market trend toward natural cosmetics. This adds to the importance of there being a wide selection of active molecules in sunscreen formulations. This paper summarizes a number of natural products derived from propolis, plants, algae, and lichens that have shown potential photoprotection properties against UV radiation exposure‐induced skin damage.
Melatonin influences somatostatin secretion from human pancreatic δ‐cells via MT1 and MT2 receptors
Authors: Zibolka Juliane , Mühlbauer Eckhard , Peschke Elmar
Published: January 2015

Melatonin is an effector of the diurnal clock on pancreatic islets. The membrane receptor‐transmitted inhibitory influence of melatonin on insulin secretion is well established and contrasts with the reported stimulation of glucagon release from α‐cells. Virtually, nothing is known concerning the melatonin‐mediated effects on islet δ‐cells. Analysis of a human pancreatic δ‐cell model, the cell line QGP‐1, and the use of a somatostatin‐specific radioimmunoassay showed that melatonin primarily has an inhibitory effect on somatostatin secretion in the physiological concentration range. In the pharmacological range, melatonin elicited slightly increased somatostatin release from δ‐cells. Cyclic adenosine monophosphate (cAMP) is the major second messenger dose‐dependently stimulating somatostatin secretion, in experiments employing the membrane‐permeable 8‐Br‐cAMP. 8‐Br‐cyclic guanosine monophosphate proved to be of only minor relevance to somatostatin release. As the inhibitory effect of 1 nm melatonin was reversed after incubation of QGP‐1 cells with the nonselective melatonin receptor antagonist luzindole, but not with the MT2‐selective antagonist 4‐P‐PDOT (4‐phenyl‐2‐propionamidotetraline), an involvement of the MT1 receptor can be assumed. Somatostatin release from the δ‐cells at low glucose concentrations was significantly inhibited during co‐incubation with 1 nm melatonin, an effect which was less pronounced at higher glucose levels. Transient expression experiments, overexpressing MT1, MT2, or a deletion variant as a control, indicated that the MT1 and not the MT2 receptor was the major transmitter of the inhibitory melatonin effect. These data point to a significant influence of melatonin on pancreatic δ‐cells and on somatostatin release.
Pan‐African phylogeography of a model organism, the African clawed frog ‘Xenopus laevis’
Authors: Furman Benjamin L. S. , Bewick Adam J. , Harrison Tia L. , Greenbaum Eli , Gvoždík Václav , Kusamba Chifundera , Evans Ben J.
Published: January 2015

The African clawed frogXenopus laevishas a large native distribution over much of sub‐Saharan Africa and is a model organism for research, a proposed disease vector, and an invasive species. Despite its prominent role in research and abundance in nature, surprisingly little is known about the phylogeography and evolutionary history of this group. Here, we report an analysis of molecular variation of this clade based on 17 loci (one mitochondrial, 16 nuclear) in up to 159 individuals sampled throughout its native distribution. Phylogenetic relationships among mitochondrial DNA haplotypes were incongruent with those among alleles of the putatively female‐specific sex‐determining geneDM‐W, in contrast to the expectation of strict matrilineal inheritance of both loci. Population structure and evolutionarily diverged lineages were evidenced by analyses of molecular variation in these data. These results further contextualize the chronology, and evolutionary relationships within this group, support the recognition ofX. laevis sensu stricto, X. petersii,X. victorianusand herein revalidatedX. powerias separate species. We also propose that portions of the currently recognized distributions ofX. laevis(north of the Congo Basin) andX. petersii(south of the Congo Basin) be reassigned toX. poweri.
Nurses' communication with families in the intensive care unit – a literature review
Authors: Adams AMN , Mannix T , Harrington A
Published: January 2015

Aims and objectives

This review examined the literature across 12 years that explored nurses' perceptions of their role when communicating with families in adult intensive care units (ICUs). The objectives were: (1) to describe how ICU nurses facilitated communication with families; (2) the perceived barriers to that communication; (3) strategies to improve their skills.

Background

Evidence demonstrates that effective communication by health care providers can improve families' understanding of their situation and decrease their psychological burden. The continuous presence of ICU nurses, combined with the use of effective empathic communication skills, can impact on families' ICU experience in a positive way. Nevertheless, research continues to demonstrate that communication with families in ICU is inadequate and of poor quality.

Search strategies and design

Eight databases were systematically searched to identify peer reviewed studies published in English between 2002 and 2014. The results are presented via a thematic literature review.

Findings

Four major themes emerged from a synthesis of the review findings: ‘Nurses as information and communication facilitators’, ‘Nurses as family support providers’, ‘Nurses’ non‐supportive behaviours' and ‘Improving nurses’ communication skills'.

Conclusions

Most ICU nurses considered communicating with families a vital part of their role, and described supportive behaviours. However, they perceived significant barriers to effective communication; some as a result of active decisions on their part, and some beyond their control. These barriers often resulted in nurses believing that families received suboptimal information and support. Peer support and formal training were identified as key strategies to overcome inadequacies.

Relevance to clinical practice

This review summarizes nurses' perceptions of the means and barriers for communicating with families in ICUs. Intensive care nurses need skills and knowledge in how to communicate effectively with families. This skill can be learnt formally, or acquired from role modelling of more experienced peers.
Redox signaling and stress tolerance in plants: a focus on vitamin E
Authors: Miret Javier A. , Munné‐Bosch Sergi
Published: January 2015

Plants are subject to specific redox processes, in which photosynthesis plays a prominent role. Chloroplasts function in light at high oxygen tensions and are enormous generators of reactive oxygen species, mainly singlet oxygen. This side product of photosynthesis inflicts damage to thylakoid membranes at high concentrations, but at the same time it is an essential component of cellular signaling. Detoxification of singlet oxygen is achieved by different means, including quenching and scavenging by tocopherols, responsible for controlling singlet oxygen levels, and the extent of lipid peroxidation in chloroplasts. Here, environmental conditions leading to excess light in chloroplasts will be used to show the importance of singlet oxygen, tocopherols, and lipid peroxidation in cell signaling. Defects in antioxidant protection (e.g., tocopherol deficiency) can lead to increased photo‐oxidative damage, but also to the activation of defense pathways, illustrating the phenotypic plasticity evolved by plants to withstand stress. Most importantly, these studies show how redox signaling processes are integrated within the cell and illustrate the great capacity of plants to adapt to their environment.
Complement C5a receptor gene 450 C/T polymorphism in renal transplant recipients: association of the CT genotype with graft outcome
Authors: Günesacar R. , Opelz G. , Erken E. , Döhler B. , Ruhenstroth A. , Süsal C.
Published: January 2015

Complement‐mediated humoral rejection has become the main focus of research in organ transplantation. The aim of this study was to investigate the possible association of the complement C5aR gene 450 C/T polymorphism in antibody‐mediated renal allograft rejection. This polymorphism was investigated in 290 first deceased donor kidney graft recipients with well functioning grafts and no rejection treatment during the first transplant year (WFG), 265 recipients with graft failure within the first transplant year (F), and 187 healthy controls. Frequency of the 450 CT genotype was lower in the total population of 555 kidney recipients (4.7%) than in 187 healthy controls (8.6%), but the difference was not statistically significant (P = 0.065). A significantly higher frequency of CT genotype was found in F patients (CT: 6.8%) when compared to WFG patients (CT: 2.8%, P = 0.027). The CT genotype was also significantly lower in WFG patients than in healthy controls (P = 0.009). Low frequency of the C5aR 450 CT genotype, which apparently is a feature of certain kidney diseases, appears to be associated with good graft outcome in kidney transplantation and might be helpful for identifying recipients who are at low risk for graft rejection.
Ethnic Residential Patterns in Urban England and Wales, 2001–2011: A System‐Wide Analysis
Authors: Johnston Ron , Poulsen Michael , Forrest James
Published: January 2015

Many cities world‐wide are becoming increasingly multi‐cultural and multi‐ethnic in their population composition. However, little attention has been paid in the massive literature on the resultant residential mosaics as to whether the outcomes of those changes are common across a national urban system or whether there are local variations – or to the factors likely to influence any such variations. Using small‐area data for towns and cities in England and Wales from the 2001 and 2011 censuses this paper finds clear relationships between the relative size of an urban area's non‐White ethnic minority population and the mix of different types of neighbourhood according to their ethnic composition – findings that have clear relevance for the development of the emerging countries' multi‐cultural character.
A clinical review of the pathophysiology, diagnosis, and treatment of pyothorax in dogs and cats
Authors: Stillion Jenefer R. , Letendre Jo‐Annie
Published: January 2015

Objective

To review the current literature in reference to the pathophysiology, diagnosis, and treatment of pyothorax in dogs and cats.

Etiology

Pyothorax, also known as thoracic empyema, is characterized by the accumulation of septic purulent fluid within the pleural space. While the actual route of pleural infection often remains unknown, the oral cavity and upper respiratory tract appear to be the most common source of microorganisms causing pyothorax in dogs and cats. In human medicine, pyothorax is a common clinical entity associated with bacterial pneumonia and progressive parapneumonic effusion.

Diagnosis

Thoracic imaging can be used to support a diagnosis of pleural effusion, but cytologic examination or bacterial culture of pleural fluid are necessary for a definitive diagnosis of pyothorax.

Therapy

The approach to treatment for pyothorax varies greatly in both human and veterinary medicine and remains controversial. Treatment of pyothorax has classically been divided into medical or surgical therapy and may include administration of antimicrobials, intermittent or continuous thoracic drainage, thoracic lavage, intrapleural fibrinolytic therapy, video‐assisted thoracic surgery, and traditional thoracostomy. Despite all of the available options, the optimal treatment to ensure successful short‐ and long‐term outcome, including the avoidance of recurrence, remains unknown.

Prognosis

The prognosis for canine and feline pyothorax is variable but can be good with appropriate treatment. A review of the current veterinary literature revealed an overall reported survival rate of 83% in dogs and 62% in cats. As the clinical presentation of pyothorax in small animals is often delayed and nonspecific, rapid diagnosis and treatment are required to ensure successful outcome.
The role of antisecretory factor in pancreatic exocrine secretion: studies in vivo and in vitro
Authors: Nawrot‐Porąbka Katarzyna , Jaworek Jolanta , Leja‐Szpak Anna , Kot Michalina , Lange Stefan
Published: January 2015

New Findings

What is the central question of this study?

Antisecretory factor, an endogenous protein detected in many tissues of the body, is known as an inhibitor of intestinal secretion, but its role in pancreatic exocrine secretory function has not yet been investigated.

What is the main finding and its importance?

In a rodent model, we show that antisecretory factor reduces pancreatic exocrine secretion, probably via its direct action on the pancreatic acini and via modulation of the enteropancreatic reflexes involving cholecystokinin and sensory nerves.

Antisecretory factor (AF) regulates ion and water transport through the intestinal cell membrane. Antisecretory factor inhibits intestinal secretion, but its effect on the exocrine pancreas has not yet been shown. We investigated the effect of AF on pancreatic amylase secretion in vivo and in vitro using pancreatic acini isolated by collagenase digestion. For the in vivo study, Wistar rats were surgically equipped with silicone catheters, inserted into the pancreaticobiliary duct and into the duodenum. Capsaicin was used to deactivate the sensory nerves in turn to assess their involvement in the effects of AF on the exocrine pancreas. Antisecretory factor (1, 3 or 10 μg kg−1 i.p.) was given in basal conditions or following stimulation of pancreatic secretion with diversion of pancreaticobiliary juice. For the in vitro study, rat pancreatic acini were incubated in the presence of increasing doses of AF (from 10−8 to 10−5 m) alone or in combination with caerulein (10−12 m). Cytoplasmic cholecystokinin 1 (CCK1) receptor protein was detected by Western blot and immunoprecipitation studies. Antisecretory factor markedly reduced the output of pancreatic amylase both in basal conditions and when stimulated by diversion of pancreaticobiliary juice. Deactivation of the sensory nerves with capsaicin completely reversed the inhibitory effects of AF on the exocrine pancreas. Caerulein‐induced enzyme secretion from the pancreatic acini was inhibited by AF, whereas basal secretion was unaffected. Administration of AF to the rats significantly diminished the synthesis of CCK1 receptor protein. We conclude that AF inhibits pancreatic exocrine secretion indirectly via sensory nerves and directly decreases amylase release from isolated pancreatic acini. The direct inhibitory action of AF on the exocrine pancreas could be related, at least in part, to a reduction of CCK1 receptors on pancreatic acinar cells.
Probabilistic Design Miming
Authors: Mukherjee Arpan , Zhang Yunbo , Rai Rahul
Published: January 2015

Design miming is a process through which a person gesticulates (move hands) to describe a real-world physical object. The core idea of this paper is to present an efficient 3D shape synthesis system and interface that can identify and display the most relevant objects based on the movements of hands. In order to implement such a system three key things are needed. First, a moderately sized 3D shape repository from where the system can find good shape matches. Second, it requires a computational tool that can convert the gestures of a user to provide input to a display interface. Third, it requires the design of an interface where synthesized 3D shapes/models could be displayed. Large databases of 3D shapes exist in online shape repositories such as Google 3D warehouse and Turbosquid, which we reuse. We focus on the second and third components of the system. Specifically, we develop a probabilistic graphical model based 3D shape synthesis approach for structure recovery from a highly noisy 3D scan of a user’s hand movements. Such a system should be real time and it imposes a computational method to have reduced time and memory complexity. We term this technique Probabilistic Design Miming (PDM) and show the utility of this technique in multiple usage scenarios.
Thermal Effects on Internal and External Resonances of a Nonlinear Timoshenko Beam
Authors: Warminska Anna , Warminski Jerzy , Manoach Emil
Published: January 2015

Large amplitude vibrations of a Timoshenko beam under an influence of thermal and mechanical loadings are studied in the paper. The structural parameters of the beam are considered enabling internal resonance conditions. Moreover, it is assumed that the beam gets instantly temperature which is distributed along its length and thickness. The mathematical model represented by a set of partial differential equations takes into account coupled mechanical and thermal fields. The problem is transformed to a set of ODEs by the Galerkin method and three modes of a simply supported beam at both ends are studied. The effect of temperature on internal and external resonances is analysed on the basis of the proposed reduced model.
Hot Forging of Automobile Steel Gear Blanks: An Exploration of the Solution Space
Authors: Ahmed Salman , Goh Chung-Hyun , Allen Janet K. , Mistree Farrokh , Zagade Pramod , Gautham B. P.
Published: January 2015

In this paper, we explore the design space associated with the realization of automobile steel gear blanks manufactured using hot forging. ABAQUS, a commercially available software package, is used to simulate the hot forging process. Surrogate models are developed and used to model the solution space. Then the compromise Decision Support Problem (cDSP) is used to explore the feasible space. Results are presented as ternary plots that allow a designer to visualize the trade-offs between competing goals such as reducing the size of the underfill, reducing the flash (excess material), waste of forged materials, energy required for deformation and crack susceptibility, on various possible solutions. The efficacy of the exploration of the design space and trade-offs between competing solutions is illustrated.
An Approach to Robust Process Design for Continuous Casting of Slab
Authors: Shukla Rishabh , Goyal Sharad , Singh Amarendra K. , Panchal Jitesh H. , Allen Janet K. , Mistree Farrokh
Published: January 2015

Continuous casting is a crucial step in the production of a variety of steel products. Its performance is measured in terms of conflicting objectives including productivity, yield, quality and production costs. These are conflicting in the sense that, if the productivity is increased, there is a reduction in other performance parameters. These performance parameters are greatly influenced by operating conditions such as casting speed, superheat, mold oscillation frequency, and secondary cooling conditions. An optimized solution for continuous casting process can be obtained. However uncertainty in operating parameters which affects the performance of caster is rarely considered. Moreover, the solution obtained is optimal with respect to a particular performance measure and does not provide a balance between all. In this paper an integrated design framework has been developed based on metamodels and the compromise Decision Support Problem (cDSP). The framework developed deals with uncertainty and yields robust solutions for performance measures. Further, the design space for continuous casting has been explored for different scenarios to determine satisficing solutions. The utility of the framework has been illustrated for providing decision support when an existing configuration for continuous casting is unable to meet the requirements. This approach can be instantiated for other unit operations involved in steel manufacturing and then may be integrated to simulate the entire production cycle of steel manufacturing. This in turn will enable development of materials with specific properties and reduce the time and cost incurred in the development of new materials and their manufacturing.
A Dimensional Design Problem of a Parallel Manipulator for the Space Docking Test System According to a Prescribed Workspace and Performance Indices
Authors: Cao Rui , Gao Feng , Zhang Yong
Published: January 2015

This paper introduces a new 6DOF parallel manipulator with a ‘3-3’-PSS structure for the space docking test system. The objective of the paper is to present a design method for determine the geometrical parameters of the 6-DOF manipulator according to a prescribed workspace and required performances. By the study of the relationships between the geometrical parameters and the performance indices of the manipulator, a new method is presented for finding all the appropriate parameters on the contour maps of the performance indices. With this method, the smallest manipulator whose workspace involves the prescribed workspace and whose performances fit the requirements could be found.
Simulating Assembly Geometric and Stress Variation Considering Machining-Induced Residual Stress
Authors: Zhang Lina , Wang Hua , Li Shuhui
Published: January 2015

Nowadays, large monolithic machined parts are increasingly used in aerospace industry. Machining-induced residual stress usually dominates thin part’s distortion. The resultant part input with mutual corresponding distortion pattern and inner residual stress has an impact on subsequent assembly geometric and stress variation of thin-walled structure. Final pre-stressed assembly state further affects product functionality. This paper illustrates a simulated methodology combining automatic scripting technique with a FEA tool to reveal the assembly variation’s distribution and pattern caused by the fluctuation of machining-induced residual stress. A typical assembly unit case in aircraft is investigated by applying the proposed methodology, more specifically, considering the uncertainty of the dominant shear stress via simulating the normal distributed weights of basis functions. Moreover, the quantitative effect of introducing residual stress is explored to examine the applicability of traditional Method of Influence Coefficients, which constructs a sensitivity matrix of the linear relation between incoming part variation and output assembly variation using FEA. This study enhances the understanding of the effect of introducing residual stress into assembly and helps the statistical inference about both geometric and stress aspects.
Effect of Uncertainty on Human Posture Prediction
Authors: Li Ning , Yang James
Published: January 2015

Posture prediction is a key component in digital human modeling and simulation. Deterministic optimization-based posture prediction formulations have been proposed. However, there exist uncertainties in human anthropometric (human height, link length, center of mass of segments, and moment of inertia, etc.) and environment parameters (location, interaction force), which affects the predicted posture. This paper attempts to study the effect of uncertainty on predicted posture. The single-loop reliability based design optimization (RBDO) method is adapted to predict posture under uncertainties. All random parameters are assumed to have normal distribution. A 24-degree of freedom (DOF) upper body model is used. In this pilot study, it is assumed that one link length and one joint angle are random parameters. The other design variables and parameters are deterministic. With the empirical rule, three cases are investigated for posture prediction. SNOPT software solver is employed to solve the optimization problem. Through comparison with deterministic optimization result and experimental data, the predicted postures from RBDO simulation show that the reliability index affects the predicted posture to some extent.
Exploration of the Design Space in Continuous Casting Tundish
Authors: Anapagaddi Ravikiran , Shukla Rishabh , Goyal Sharad , Singh Amarendra K. , Allen Janet K. , Panchal Jitesh H. , Mistree Farrokh
Published: January 2015

Due to the stringent requirements of industry, it has become extremely important to have a careful control over the required performance and properties of steels. Performance and properties of advanced high strength steel depend significantly on its cleanliness. Cleanliness is achieved by restricting the inclusion count to a permissible limit. Over the past few years, there has been increased use of tundish, a device that acts as a buffer between ladle and mold, for controlling inclusions. Apart from facilitating inclusion removal, tundish also maintains low dead volume and thermal and chemical homogeneity, which is required for smooth casting operation. Thus, performance of the tundish operation greatly influences the properties and quality of the cast slab. Tundish performance is generally assessed using parameters such as inclusion removal efficiency, dead volume within tundish and effectiveness in maintaining the desired amount of superheat. But, the aforesaid parameters are conflicting in nature. Managing the conflict and providing a satisficing solution based on the customer requirements become essential.

In this paper, we present an approach to manage the conflicts involved in designing a tundish. An integrated framework, by linking meta-models with compromise Decision Support Problem (cDSP) construct, is developed to determine a satisficing solution considering conflicting requirements.

The utility of the framework is illustrated by providing decision support when an existing configuration for tundish is unable to meet the requirements. This has been done by exploring the design space of tundish and coming up with a design and operating set points suitable for a particular purpose. This approach can be instantiated for other unit operations involved in steel manufacturing. In the future, each unit operation can be integrated to provide a complete picture of steel manufacturing which in turn will help in reducing the time and cost incurred in the development of new materials and products.
In-Plane Rigid Ring-Based Tire Model: Parameter Identification, Sensitivity Analyses, and Effect on Ride Comfort
Authors: Li Bin , Li Ning , Yang Xiaobo , Yang James
Published: January 2015

The tire is the main interface between the vehicle and road, and all maneuvers controlled by a driver to road vehicle are achieved by the interaction force between tire and road. In modern vehicle design, tire modeling plays an important role in effectively assessing vehicle handling, ride comfort, and road load analysis. The long term goal of this research is to develop a three-dimensional robust tire model that can be used for road load durability simulation. This work is the first step to the long term goal. This paper presents a new simplified in-plane tire model based on a traditional rigid ring tire model. The interaction between the tire and road is assumed to be patch contact. Optimization technique is used to obtain all key tire parameters of the tire model by minimizing the vertical and horizontal contact forces between the model simulation results and road test data when a tire passes a road bump. After the parameters are identified, a full factorial design of experiments with three levels for each of 8 parameters (horizontal spring stiffness and damper coefficient, vertical spring stiffness and damper coefficient, rotational spring stiffness and damper coefficient between the rim and ring, ring radius, ring residual spring stiffness) is conducted for parameter sensitivity analysis. The three levels for each parameter except the ring radius are 50% increase, 50% decrease, and nominal values. Sensitivity analysis has shown that several parameters are critical to the peak value of the vertical and horizontal contact forces. A quarter-car model is then used to assess ride comfort of the vehicle suspension system. The quarter-car model with the proposed tire model can more accurately predict the ride comfort subject to random road inputs than the one with point contact tire model.
Lie Group Modeling of Nonlinear Helical Beam Elements
Authors: Jödicke Ralph , Jungnickel Uwe , Müller Andreas
Published: January 2015

A viscoelastic beam model is presented based on SE(3) group theory. We discretize a rod with beams between finite frames on the rod and regard the configurations of these frames as elements of the SE(3) Lie group. Two subsequent frames are connected by a beam. The curvatures and strains are assumed to be constant on the trajectory between them. If the deflection curve of the beam is modeled as a helix, the resulting beam model is geometrical exact for large bending deformations. The stiffness matrices of the discrete beam elements result from the potential extensional and shearing energy as well as from the potential bending and torsion energy. The benefit of this SE(3) modeling for translational elastic coordinates and for translational forces in comparison to an SO(3) × ℝ3 variant is demonstrated.
A Feedback Control Strategy for Torque-Vectoring of IWM Vehicles
Authors: Braghin Francesco , Sabbioni Edoardo , Sironi Gabriele , Vignati Michele
Published: January 2015

In last decades hybrid and electric vehicles have been one of the main object of study for automotive industry. Among the different layout of the electric power-train, four in-wheel motors appear to be one of the most attractive. This configuration in fact has several advantages in terms of inner room increase and mass distribution. Furthermore the possibility of independently distribute braking and driving torques on the wheels allows to generate a yaw moment able to improve vehicle handling (torque vectoring). In this paper a torque vectoring control strategy for an electric vehicle with four in-wheel motors is presented. The control strategy is constituted of a steady-state contribution to enhance vehicle handling performances and a transient contribution to increase vehicle lateral stability during limit manoeuvres. Performances of the control logic are evaluated by means of numerical simulations of open and closed loop manoeuvres. Robustness to friction coefficient changes is analysed.
Dynamically Feasible Trajectories for Three-DOF Planar Cable-Suspended Parallel Robots
Authors: Jiang Xiaoling , Gosselin Clément
Published: January 2015

This paper proposes a trajectory planning technique for planar three-degree-of-freedom cable-suspended parallel robots. Based on the kinematic and dynamic modelling of the architecture, force constraints that can guarantee that cables remain under tension are obtained. Periodic parametric trajectories that extend beyond the static workspace are designed. The trajectories involve combined translations and rotations. Substituting the trajectories into the force constraints, interval arithmetics is used to search for global conditions on the trajectory parameters which ensure that the trajectories are feasible. Special frequencies related to combined rotational and translational motions are exposed which can be used to better exploit cable-suspended robots. Moreover, it is observed that the special frequencies related to the translation are akin to the natural frequency of pendulum-like systems. The proposed trajectory planning approach can be used to plan combined rotational and translational dynamic trajectories that can extend beyond the static workspace of the mechanism, thereby opening novel applications and possibilities for cable-suspended robots.
Implementation and Validation of a 4-Node Shell Finite Element
Authors: Morandini Marco , Masarati Pierangelo
Published: January 2015

This paper discusses the formulation and implementation of a 4-node C0 shell element within a general-purpose multibody formulation. A geometrically consistent set of strains and curvatures, defined in a co-rotational framework, is augmented by Enhanced Assumed Strains (EAS) and Assumed Natural Strains (ANS), to alleviate shear and membrane locking. The shell element formulation is validated by solving several static and dynamic problems from the open literature. The proposed element has been successfully used for the coupled structural and fluid-dynamics analysis of flapping wing micro-aerial vehicles.
Nonlinear Membrane Direct and Inverse FEM Analysis
Authors: Alioli Mattia , Masarati Pierangelo , Morandini Marco , Carpenter Trenton , Albertani Roberto
Published: January 2015

The analysis of thin structural components integrated within a general-purpose multibody system dynamics formulation is presented. An original inverse finite element solution procedure is developed to reconstruct the deformed shape of a membrane from in-plane membrane strain measurements, and eventually indirectly estimate the distributed loads. A direct solution approach is used in co-simulation with fluid-dynamics solvers to predict the configuration of the system under static and unsteady loads. Numerical validation of the inverse solution is performed considering the results of direct solution analysis. The direct and inverse solutions are validated considering experimental displacement and strain measurements obtained using digital image correlation. Moving Least Squares are used to smooth and remap measurements as needed by the inverse solution meshing. Utilizing surface strain measurements from strain sensors, the methodology enables the accurate computation of the three-dimensional displacement field.