bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequent Falling and Motor Vehicle Collision Involvement of Older Drivers
Authors: Huisingh Carrie , McGwin Gerald , Orman Katherine A. , Owsley Cynthia
Published: November 2013

Objectives

To examine the relationship between frequent falls in older drivers and motor vehicle collision (MVC) involvement.

Design

Cross‐sectional.

Setting

North central Alabama.

Participants

Population‐based sample of 2,000 licensed drivers aged 70 and older.

Measurements

Self‐reported history of falling two or more times in the prior year was the main predictor. Outcomes were any MVC or at‐fault MVC in the prior year.

Results

Approximately 9% of older drivers reported having fallen two or more times in the prior year. Logistic regression models indicated that frequent falling was associated with having any MVC (crude odds ratio (OR) = 1.53, 95% confidence interval (CI) = 0.77–3.02) and an at‐fault MVC (OR = 2.21, 95% CI = 0.97–5.06). Adjustment for the potentially confounding effects of demographic, health, visual, and driving characteristics did not meaningfully affect the association with any MVC, whereas the association with at‐fault MVC was weakened (adjusted OR = 2.03, 95% CI = 0.84–4.90).

Conclusion

Frequent falling was associated with at‐fault MVC involvement of older drivers, especially whites. History of falling can be used to identify individuals at risk of MVC involvement and to begin a dialogue about driver safety.
Applying Industrial Symbiosis to Smallholder Farms
Authors: Alfaro Jose , Miller Shelie
Published: November 2013

The study of industrial symbiosis (IS) has largely focused on the exchange of energy and materials among industrial processes in an effort to increase value and reduce environmental impact. Agricultural systems, particularly those located in developing countries, can benefit from the principles of IS. Relatively few studies have analyzed the potential benefits of integrated material and energy flows in smallholder farming, even though these systems are considered essential to the world's food supply and poverty reduction.

Although the concepts can be applied to virtually any system, the study of industrial symbiosis has traditionally focused on industrialized systems in developed countries. The research presented here applies the principles of IS to smallholder farms using optimization techniques to maximize farm output while minimizing wastes. Our research links IS to the growing field of integrated farming research (IFR), which seeks to create new technologies that increase the production of farms by viewing the farm as a system. Bridging these fields enriches the potential for robust research outcomes in both areas and fills a current knowledge gap. IS benefits from exploring new applications and increasing its penetration into the developing world. IFR benefits from established IS tools to create alternate pathways for increased output based on symbiotic relationships.

A small farming system in Liberia, West Africa, is used as a case study. System integration of individual unit processes shows increased productivity and decreased waste. The results of this analysis indicate that there are unrealized opportunities for IS in developing countries, and integration of IS techniques into smallholder farming operations has the potential for impacting sustainable development.
The initial garnet‐in reaction involving siderite–rhodochrosite, garnet re‐equilibration and P–T–t paths of graphitic schists in the Black Hills orogen, South Dakota, USA
Authors: Nabelek P. I. , Chen Y.
Published: November 2013

It is generally thought that garnet in metapelites is produced by continuous reactions involving chlorite or chloritoid. Recent publications have suggested that the equilibrium temperatures of garnet‐in reactions may be significantly overstepped in regionally metamorphosed terranes. The growth of small spessartine–almandine garnet crystals on Mn‐siderite at the garnet isograd in graphitic metapelites in the Proterozoic Black Hills orogen, South Dakota, demonstrates that Mn‐siderite was the principal reactant that produced the initial garnet in the schists. Moreover, the positions of garnet compositions in isobaric, T–(C/H) pseudosections for the schists show that the temperature of the garnet‐in reaction from Mn‐siderite was overstepped minimally at the most. In the Black Hills, garnet was initially produced during regional metamorphism beginning at c. 1755 Ma due to the collision of Wyoming and Superior cratons, and was subsequently partially or fully re‐equilibrated at more elevated temperatures and pressures during intrusion of the Harney Peak Granite (HPG) at c. 1715 Ma. Garnet occurs in graphitic schists in garnet, staurolite and sillimanite zones, the latter being a product of contact metamorphism by HPG. During metamorphism, coexisting fluid contained both CO2 and CH4. In the garnet zone, garnet crystals contain petrographically distinct cores with inclusions of quartz, graphite and other minerals. Centres of the cores have distinctly elevated Y concentrations that mark the positions of garnet nucleation. The elevated Y is thought to have come from the Mn‐siderite onto which Y was probably absorbed during precipitation in an ocean. In the upper garnet and staurolite zones, the cores were overgrown by inclusion‐poor mantles. Mantles are highly zoned and have more elevated Fe and Mg and lower Mn and Ca than cores. The growth of mantles is attributed to late‐orogenic heating by leucogranite magmas and attendant influx of H2O that caused consumption of graphite in rock matrices. A portion of the Proterozoic terrane that includes the HPG is surrounded by four large faults. In this ‘HPG block’, garnet is inclusion‐poor and its composition does not preserve its early growth history. This garnet appears to have re‐equilibrated by internal diffusion of its major components and/or recrystallization of an earlier inclusion‐rich garnet. It has equilibrated within the kyanite stability range, and together with remnant kyanite in the high‐strain aureole of the HPG, indicates that the HPG block had a ≥6 kbar history. The HPG block has undergone decompression during emplacement of the HPG. The decompression is evident in occurrences of retrograde andalusite and cordierite in the thermal aureole of the HPG. The data support a polybaric metamorphic history of the Black Hills orogen with different segments of the orogen having their own clockwise P–T–t paths.
The Human Neurosecretory Neurones Under Perinatal Hypoxia: A Quantitative Immunohistochemical Study of the Supraoptic Nucleus in Autopsy Material
Authors: Pagida M. A. , Konstantinidou A. E. , Malidelis Y. I. , Ganou V. , Tsekoura E. , Patsouris E. , Panayotacopoulou M. T.
Published: November 2013

In the rat, experimental manipulations that cause activation of the magnocellular neurosecretory neurones result in the synthesis, in addition to vasopressin (AVP) and oxytocin (OXY), of other neurotransmitters or peptides, including tyrosine hydroxylase (TH), the first and rate limiting enzyme for catecholamine biosynthesis. In the human neonate, our previous study showed that TH was selectively increased in AVP neurones of subjects that died from prolonged perinatal hypoxia. The purpose of the present study was to quantitatively investigate the expression of TH, AVP, OXY and neurophysin in magnocellular neurones of the human neonate in relation to the severity/duration of perinatal hypoxia, as estimated by neuropathological criteria. Autopsy was performed after obtaining parental written consent for diagnostic and research purposes. The intensity of the immunohistochemical reactions and the cellular/nuclear size were measured in the dorsolateral supraoptic nucleus using a computerised image analysis system. We showed that prolonged perinatal hypoxia resulted in the activation of the magnocellular neuroendocrine neurones of the human neonate, as indicated by their increased neuronal and nuclear size. OXY neurones appeared larger than the AVP ones at birth, possibly indicating an active role of foetal OXY during labour or even earlier. The gradual increase in the duration of the insult resulted in the reduction of intracellular AVP content, in parallel with a dramatic increase in the expression of TH, indicating a functional interaction of these peptides under neuronal activation. Ιsolated evidence in our series, obtained from an infant of a diabetic mother, raises the probability that in the case of hyperglycaemia the above pathogenetic mechanisms are diversified.
Delayed intravesical mesh erosion in a midurethral sling following further mesh‐augmented pelvic prolapse surgery
Authors: Lo Tsia‐Shu , Pue Leng Boi , Tan Yiap Loong , Khanuengkitkong Siwatchaya , Krishna Dass Anil
Published: November 2013

Intravesical mesh erosion and extrusion have been reported as devastating late complications of synthetic suburethral sling placement for the treatment of stress urinary incontinence. We report a case of a female patient with intravesical mesh erosion from a sling suspension that developed 4 years after primary prolapse surgery with mesh reinforcement. Intravesical mesh erosion was observed ultrasonographically and confirmed through cystoscopy. We excised the mesh via a vaginal approach and repaired both bladder mucosa and vaginal wall. As of this writing, the patient has been symptom‐free for the past year post‐surgery. Long‐term follow‐up is recommended in such cases. Anti‐incontinence surgery followed by primary prolapse surgery could potentially jeopardize the former. Complications may arise several years later so long‐term follow‐up is essential. Ultrasonography is an effective tool in evaluating mesh morphology and detecting intravesical mesh erosion.
Lacustrine Nostoc (Nostocales) and associated microbiome generate a new type of modern clotted microbialite
Authors: Graham Linda E. , Knack Jennifer J. , Piotrowski Michael J. , Wilcox Lee W. , Cook Martha E. , Wellman Charles H. , Taylor Wilson , Lewis Louise A. , Arancibia‐Avila Patricia
Published: November 2013

Microbialites are mineral formations formed by microbial communities that are often dominated by cyanobacteria. Carbonate microbialites, known from Proterozoic times through the present, are recognized for sequestering globally significant amounts of inorganic carbon. Recent ecological work has focused on microbial communities dominated by cyanobacteria that produce microbial mats and laminate microbialites (stromatolites). However, the taxonomic composition and functions of microbial communities that generate distinctive clotted microbialites (thrombolites) are less well understood. Here, microscopy and deep shotgun sequencing were used to characterize the microbiome (microbial taxa and their genomes) associated with a single cyanobacterial host linked by 16S sequences to Nostoc commune Vaucher ex Bornet & Flahault, which dominates abundant littoral clotted microbialites in shallow, subpolar, freshwater Laguna Larga in southern Chile. Microscopy and energy‐dispersive X‐ray spectroscopy suggested the hypothesis that adherent hollow carbonate spheres typical of the clotted microbialite begin development on the rigid curved outer surfaces of the Nostoc balls. A surface biofilm included >50 nonoxygenic bacterial genera (taxa other than Nostoc) that indicate diverse ecological functions. The Laguna Larga Nostoc microbiome included the sulfate reducers Desulfomicrobium and Sulfospirillum and genes encoding all known proteins specific to sulfate reduction, a process known to facilitate carbonate deposition by increasing pH. Sequences indicating presence of nostocalean and other types of nifH, nostocalean sulfide:ferredoxin oxidoreductase (indicating anoxygenic photosynthesis), and biosynthetic pathways for the secondary products scytonemin, mycosporine, and microviridin toxin were identified. These results allow comparisons with microbiota and microbiomes of other algae and illuminate biogeochemical roles of ancient microbialites.
Doing and enacting economies of value: Thinking through the assemblage
Authors: Carolan Michael
Published: November 2013

This paper speaks to the generative capacities of research more generally and the biological economies process specifically. It highlights the importance of being disruptive and critical while avoiding the traps of structuralist paranoia that keep one from seeing and doing difference. It also seeks to move through, rather than beyond, conventional understandings of value, to include emergent practices, relationships and more‐than‐representational knowledge. In total, it is a rather wild piece about New Zealand biological economies scholarship, in terms of how certain performances are made strange, become altered and lead to the enactment of novel states of becoming.
Using provenance to create stability: State‐led territorialisation of Central Otago as assemblage
Authors: Rosin Christopher , Dwiartama Angga , Grant Darryl , Hopkins Debbie
Published: November 2013

In this paper, we consider the implications of assemblage as an analytical framework in the context of regional economic planning, drawing on Deleuze and Guattari's concept of territoriality to examine the efforts to create temporal stability in the emergent regional economy. We focus on the reterritorialisation of Central Otago through the district council's destination management project centred on the collective branding of the region as ‘A World of Difference’. The implementation of this programme contends with the diverse, incongruent boundaries of emergent tourism activities. The paper, thus, addresses the potential for state initiatives to manage uncertain and ephemeral assemblages.
Worlds of wool: Recreating value off the sheep's back
Authors: Pawson Eric , Perkins Harvey
Published: November 2013

Recent attempts to recreate the wealth once generated inNewZealand from wool are discussed. These attempts are theorised as active processes of assemblage within overlapping and interacting social worlds. The focus of the paper is ethnographic, engaging with the actors in worlds of wool as they experiment with ways to retain and add value by enhancing connectivity between farmer‐producers, manufacturers and consumers; delineating and capturing value by constructing new products and brands; and continually developing metrologies, making new animals and advancing an array of environmental and social values. The study focuses on fine and strong wool worlds.
Calcification during bone healing in a standardised rat calvarial defect assessed by micro‐CTandSEM‐EDX
Authors: Okata H , Nakamura M , Henmi A , Yamaguchi S , Mikami Y , Shimauchi H , Sasano Y
Published: November 2013

Objective

The study was designed to investigate the process of calcification during bone healing in a standardised rat calvarial bone defect model, measured by bone mineral density and the concentrations and distributions of calcium, phosphorus and carbon in the bone matrix.

Materials and methods

A standard defect was made on the parietal bone of 12‐week‐old rats under anaesthesia. The rats were fixed in weeks 1, 2, 4 and 8, and the calvaria were resected and examined with microcomputed tomography, then frozen and sectioned for histology and analysed with energy‐dispersive X‐ray spectroscopy (EDX). Parietal bone of 12‐week‐old control rats was processed similarly.

Results

The mineral density of healing bone increased with time. The healing bone became thicker and denser with time in histology. The distributions of Ca and P expanded over the bone matrix, whereas that of C became localised and complemented that of C and P. The Ca/P concentration ratio increased, whereas the C/Ca and C/P ratios decreased in the healing bone matrix.

Conclusion

Healing bone is immaturely calcified initially and proceeds calcification gradually, that is, as the bone volume increases, mineral increases in density and matures in quality, while organic components decrease.
Dermoscopy to Identify Dermal Thinning
Authors: Nagler Arielle , Mazza Joni , Kil Erin , Silverberg Nanette B.
Published: November 2013

Biopsying of children is often difficult to accomplish and traumatic. Consequently, techniques that avert biopsy are welcome in children. We describe the use of handheld dermoscopy for confirmation of the diagnosis of lesions with dermal thinning, including focal dermal hypoplasia, aplasia cutis, and striae. The major advantage of this technique is rapid diagnosis in the absence of a surgical procedure.
Periungual Bowen's Disease in a 4‐Year‐Old Girl
Authors: Kim Sharon , Sun Grace S. , Wright Teresa S.
Published: November 2013

Bowen's disease (BD), or cutaneous squamous cell carcinoma (SCC) in situ, is rare in children. BD usually occurs in Caucasian adults on sun‐exposed areas and may progress to invasive cutaneous SCC. Most cases of periungual BD have been linked to human papillomavirus infection. We report an immunocompetent child with periungual BD.
Pleomorphic liposarcoma: A clinicopathological, immunohistochemical and molecular cytogenetic study of 32 additional cases
Authors: Wang Lei , Ren Weimin , Zhou Xiaoyan , Sheng Weiqi , Wang Jian
Published: November 2013

The purpose of this study is to report the author's experience with 32 cases of pleomorphic liposarcoma to further broaden the clinicopathological spectrum. The tumours occurred equally in males and females with ages ranging from 11 to 83 years (median, 56 years). Tumour site included the extremities (17 cases), abdomen/retroperitoneum (4 cases), internal organs (5 cases), thoracic cavity/mediastinum (2 cases), orbit, neck, groin and scrotum (1 case each). The diagnostic pleomorphic lipoblasts were identified in 31 primary tumours and one recurrent tumor but varied widely in proportion between cases or different areas of the same tumor. Four tumors contained sheets or focal aggregates of lipoblasts with epithelioid morphology. The nonlipogenic component in 26 cases had an appearance of undifferentiated pleomorphic sarcoma, whereas in six cases it was consistent with intermediate to high grade myxofibrosarcoma. The pleormorphic and epithelioid lipoblasts displayed variable expression of S100 protein. There was no signal of amplified MDM2 gene in 10 cases tested by fluorescence in situ hybridization. This study further illustrates that pleomorphic liposarcoma is a distinctive entity with no relationship to either well differentiated liposarcoma or dedifferentiated liposarcoma. Albeit very rare, pleomorphic liposarcoma can occur in teenaged patients and internal organs.
Histological assessment of intra‐ and inter‐institutional reliabilities in detection of desmoplastic reaction in biopsy specimens of early colorectal carcinomas
Authors: Okamoto Yosuke , Fujimori Takahiro , Ohkura Yasuo , Sugai Tamotsu , Arai Tomio , Watanabe Gen , Wada Ryo , Ueno Hideki , Togashi Kazutomo , Yao Takashi , Kushima Ryoji , Mitomi Hiroyuki , Tomita Shigeki , Igarashi Yoshinori , Ichikawa Kazuhito
Published: November 2013

We previously reported a relationship between depth of submucosal invasion of early colorectal carcinomas and desmoplastic reaction (DR). However, poor inter‐observer agreement on the histopathological diagnosis of DR in biopsy specimens with hematoxylin and eosin (H&E) staining has been the major critique of this tool. In this study, reproducibility of the histopathological diagnosis of DR was evaluated. Furthermore, we investigated the possible improvement of the reproducibility after education about histological characteristics and tried to identify histological characteristics that are most important in the recognition of DR. A total of 34 H&E stained slides were included in this study and analyzed by three pathologists. Slides were reviewed before and after education about histological characteristics of DR. Kappa statistics were used to compare the inter‐observer variability. We investigated the relationship between DR and histopathological factor. The inter‐observer agreement during the first session varied between 0.30 and 0.63, which improved during the second session toward an agreement between 0.58 and 0.71. Myofibroblast proliferation associated with cancer invasion was found to be the most useful in the diagnosis of DR. In conclusion, the correct detection of myofibroblasts may facilitate the standardization of diagnosis of DR.
Do Country‐of‐Origin Characteristics Help Explain Variation in Health Among Black Immigrants in the United States?
Authors: Hamilton Tod G.
Published: November 2013

Objective

Black immigrants in the United States migrate from a diverse set of countries, including countries in the Caribbean, Central America, South America, Europe, and Africa. This study evaluates whether disparate conditions in black immigrants’ birth countries help explain variation in their postmigration health.

Methods

Using data on black immigrants from the 2001 to 2012 waves of the March Current Population Survey (CPS) along with country data from the 2009 Human Development Report of the United Nations Development Programme, this study examines whether social, economic, and health conditions in black immigrants’ birth countries have an independent effect on their postmigration health.

Results

Results show that health is more favorable among black immigrants who migrate from countries with a relatively high combined gross enrollment ratio for primary, secondary, and tertiary education; low levels of income inequality; and high life expectancies at birth. After controlling for country conditions, relative to non‐African immigrants, African immigrants report the best health.

Conclusion

Future studies on the health of immigrants should incorporate characteristics of immigrants’ birth countries. This information could provide valuable insights into the roles of selective migration and birth‐country conditions in explaining variation in immigrants’ postmigration health.
Field evaluation of soil moisture deficit thresholds for limits to trafficability with slurry spreading equipment on grassland
Authors: Vero S. E. , Antille D. L. , Lalor S. T. J. , Holden N. M.
Published: November 2013

This study investigated the extent of soil damage caused by field traffic associated with different levels of soil moisture deficit (SMD). The hybrid SMD model was used for computing temporal patterns of SMD which can be accurately predicted for a range of soil types in Ireland. The aim of this study was to determine SMD threshold limits to trafficability for incorporation into a decision support system for safe slurry spreading. A tractor and a fully loaded single‐axle slurry tanker (total weight ca. 18 tonnes) were driven over well, moderate and poorly drained soils at SMD values of 0, 5, 10 and 20 mm during drying phases. The change in soil bulk density (SBD) was used as an indicator of soil compaction, and rut profile measurements were taken to determine soil deformation indicative of surface damage. The effect of traffic on the grass crop was determined by measuring dry matter yield at 30 and 60 days posttraffic in the wheel‐rut and nontrafficked area. Results showed that the SMD at the time of traffic had a significant (P < 0.05) effect on the magnitude of the changes in SBD on soils of different drainage status, and on rut dimensions following traffic. DMY was significantly (P < 0.05) reduced on the wheeled compared with the nonwheeled soil. No differences in the magnitude of DMY loss were identified between the sites having different drainage status. An SMD value of 10 mm was suggested as an SMD threshold for trafficability for safe slurry spreading purposes.
Asking for something different from our donors: factors influencing persuasion success
Authors: Bagot Kathleen L. , Bove Liliana L. , Masser Barbara M. , White Katherine M.
Published: November 2013

Background

Demand for plasma‐derived products, and consequently plasmapheresis donors, continues to increase. This study aims to identify the factors that facilitate the persuasion success of conversations with whole blood (WB) donors to convert to plasmapheresis donation within a voluntary nonremunerated context.

Study Design and Methods

Surveys were sent to WB donors after a plasmapheresis conversion conversation with a blood collection agency (BCA) staff member: in center (Sample 1) or via a call center (Sample 2). Participants reported the number of donor‐initiated and BCA‐initiated conversations about plasma, experienced in the prior 12 months. Perceptions of the most recent conversation, donor oriented and conversion oriented, were also reported. The BCA provided WB donation history for the prior 5 years. Participants' intentions to make a first plasmapheresis donation were captured and any subsequent plasmapheresis donation was objectively recorded.

Results

Conversion rates were higher for in‐center than call center–based conversations. For both samples, path analyses revealed that intentions are associated with conversion. Prior WB donations are negatively associated, while donor‐initiated and donor‐orientated conversations are positively associated with conversion intentions. Results for agent‐initiated conversations and conversion‐orientated conversations were mixed across samples.

Conclusion

Converting suitable WB donors to plasmapheresis is best achieved early in the donor's career using face‐to‐face conversations with collection center staff. BCAs should facilitate donor‐initiated conversations through promotional campaigns that encourage donors to approach staff. Conversations that focus on donors' needs and welfare more effectively encourage conversion intentions than those perceived as pushing the requirements of the BCA.
The Zoonotic Potential of Daptomycin Non‐susceptible Enterococci
Authors: Kelesidis T.
Published: November 2013

Daptomycin non‐susceptible Enterococcus (DNSE) is an emerging clinical problem. Little is known about how de novo DNSE infections develop or the risk factors associated with them. Determining risk factors associated with de novo DNSE infections will aid in understanding the mechanisms of daptomycin non‐susceptibility. Humans in contact with animals worldwide are at risk of carriage of multidrug‐resistant bacteria. Herein, I review the scientific evidence that supports the hypothesis that transport of daptomycin non‐susceptibility genes between animals and humans may be a possible mechanism for development of de novo daptomycin non‐susceptibility in enterococci.
Galois representations associated to holomorphic limits of discrete series
Authors: Goldring Wushi , Shin Sug Woo
Published: November 2013

Generalizing previous results of Deligne–Serre and Taylor, Galois representations are attached to cuspidal automorphic representations of unitary groups whose Archimedean component is a holomorphic limit of discrete series. The main ingredient is a construction of congruences, using the Hasse invariant, that is independent of$q$-expansions.
Mechanisms by which a CACNA1H mutation in epilepsy patients increases seizure susceptibility
Authors: Eckle Veit‐Simon , Shcheglovitov Aleksandr , Vitko Iuliia , Dey Deblina , Yap Chan Choo , Winckler Bettina , Perez‐Reyes Edward
Published: November 2013

Key points

Mutations in the Cav3.2 T‐type Ca2+ channel were found in patients with idiopathic generalized epilepsies, yet the mechanisms by which these mutations increase neuronal excitability and susceptibility to seizures remain to be determined.

Using electrophysiological and transfection methods, we validate in cultured hippocampal neurons the hypothesis that an epilepsy mutation increases neuronal excitability.

Mutations in the I–II loop of the channel increase trafficking to the plasma membrane without altering trafficking into dendrites. Mutations also enhance dendritic arborization.

Additionally, we provide the first evidence that Cav3.2 can signal to Ca2+‐regulated transcription factors, which are known to play important roles in neuronal development and gene expression.

T‐type calcium channels play essential roles in regulating neuronal excitability and network oscillations in the brain. Mutations in the gene encoding Cav3.2 T‐type Ca2+ channels, CACNA1H, have been found in association with various forms of idiopathic generalized epilepsy. We and others have found that these mutations may influence neuronal excitability either by altering the biophysical properties of the channels or by increasing their surface expression. The goals of the present study were to investigate the excitability of neurons expressing Cav3.2 with the epilepsy mutation, C456S, and to elucidate the mechanisms by which it influences neuronal properties. We found that expression of the recombinant C456S channels substantially increased the excitability of cultured neurons by increasing the spontaneous firing rate and reducing the threshold for rebound burst firing. Additionally, we found that molecular determinants in the I–II loop (the region in which most childhood absence epilepsy‐associated mutations are found) substantially increase the surface expression of T‐channels but do not alter the relative distribution of channels into dendrites of cultured hippocampal neurons. Finally, we discovered that expression of C456S channels promoted dendritic growth and arborization. These effects were reversed to normal by either the absence epilepsy drug ethosuximide or a novel T‐channel blocker, TTA‐P2. As Ca2+‐regulated transcription factors also increase dendritic development, we tested a transactivator trap assay and found that the C456S variant can induce changes in gene transcription. Taken together, our findings suggest that gain‐of‐function mutations in Cav3.2 T‐type Ca2+ channels increase seizure susceptibility by directly altering neuronal electrical properties and indirectly by changing gene expression.
Mechanics of Confined Thin-Walled Cylinders Subjected to External Pressure
Authors: Vasilikis Daniel , Karamanos Spyros A.
Published: November 2013

Motivated by practical engineering applications, the present paper examines the mechanical response of thin-walled cylinders surrounded by a rigid or deformable medium, subjected to uniform external pressure. Emphasis is given to structural stability in terms of buckling, postbuckling, and imperfection sensitivity. The present investigation is computational and employs a two-dimensional model, where the cylinder and the surrounding medium are simulated with nonlinear finite elements. The behavior of cylinders made of elastic material is examined first, and a successful comparison of the numerical results is conducted with available closed-form analytical solutions for rigidly confined cylinders. Subsequently, the response of confined thin-walled steel cylinders is examined. The numerical results show an unstable postbuckling response beyond the point of maximum pressure and indicate severe imperfection sensitivity on the value of the maximum pressure. A good comparison with limited available test data is also shown. Furthermore, the effects of the deformability of the surrounding medium are examined. In particular, soil embedment conditions are examined, with direct reference to the case of buried thin-walled steel pipelines. Finally, based on the numerical results, a comparison is attempted between the present buckling problem and the problem of “shrink buckling.” The differences between those two problems of confined cylinder buckling are pinpointed, emphasizing the issue of imperfection sensitivity.
Multi-Objective Optimization of Microturning Process Parameters Using Particle Swarm Technique
Authors: Mathew Nithin Tom , Mani Kanthababu
Published: November 2013

In this work, for the first time an attempt has been made to carry out multi-objective optimization for tool based microturning process parameters using particle swarm optimization (PSO) technique. The input microturning process parameters considered are speed, feed and depth of cut. The output parameters considered are material removal rate (MRR), surface roughness (Ra) and tool wear (TW). The significant parameters are identified individually using ANOVA and main effect plots. However, it is observed that the main goal of the manufacturers is to produce high quality products in shorter interval of time. In order to meet the above objective, multi-objective optimization is carried out to achieve simultaneously higher MRR, low Ra and low TW using PSO. From the PSO analysis, it is observed that the combination of microturning parameters such as speed (18.25 m/min), feed (9.31 μm/rev) and depth of cut (14.61 μm) results in high MRR, low Ra and low tool wear. The PSO analysis indicates that it is a promising optimization algorithm due to its simplicity, low computational cost and good performance. A confirmation test was carried out to validate the predicted results.
Requirements for Moving Towards Liquid Molding of Large Composite Structures for Aerospace
Authors: Tsotsis Thomas K.
Published: November 2013

Requirements for moving beyond the current state of the art in polymer-matrix composites for large commercial and military transport aircraft via the use of liquid molding will be presented. These requirements will be rooted in understandings of regulatory safety requirements and in recent developments in materials and modeling. Key parameters such as the interrelationships between modeling, quality control, and scale-up will be discussed in some detail with a focus on how these need to be matured or adapted for aerospace usage and how they address the persistent need for improved performance at reduced weight. Ongoing work in several technologies will be presented relative to how they fit into the maturation of next-generation composites and tools for developing new composite materials. Scale-up will be illustrated by examples in modeling moving up from material-property-level requirements to system-level performance and moving down to micro and submicron level. These illustrations will be used to show an approach for effectively moving between scales in modeling, testing, fabrication, and design.
Characterization of Printable Micro-Fluidic Channels for Organ Printing
Authors: Zhang Yahui , Yu Yin , Ozbolat Ibrahim Tarik
Published: November 2013

Despite great progress in tissue engineering, there still exist limitations in engineering and manufacturing thick tissues. The engineered construct is still trapped in a geometrically simple and thin structure due to an inefficient transportation system. In traditional scaffolding, the media exchange rate mainly depends on media diffusion. Even a porous scaffold cannot provide enough media for the high metabolic rate of thick tissue. Embedding microfluidic channels has great potential to increase media exchange capability. The existing microfluidic channel fabrication methods are limits as well. Microfluidic channels with interconnectivity, 3D dimension, or complex geometry have not been achieved. To address these issues, a novel printable microfluidic channel fabrication method is introduced in this paper.

This research investigates the manufacturability of novel cellular micro-fluidic channels. The proposed micro-fluidic channels can directly construct a scaffold that will provide both support of mechanical integrity and fluid transport in 3D. The main purpose of this paper is to experimentally analyze the effect of dispensing parameters and media flow characteristics on resulting microfluidic channels.
A Model Based Computationally Efficient Method for On-Line Detection of Chatter in Milling
Authors: Ma Lei , Melkote Shreyes , Castle James
Published: November 2013

This paper presents a model-based computationally efficient method for detecting milling chatter in its incipient stages. Based on a complex exponentials model for the dynamic chip thickness, the chip regeneration effect is amplified and isolated from the cutting force signal for early chatter detection. The proposed method is independent of the cutting conditions. With the aid of a one tap adaptive filter, the proposed method is also found to be able to distinguish between chatter and the dynamic transients in the cutting forces due to sudden changes in workpiece geometry and tool entry/exit. The proposed method is experimentally validated.
Correlation Between Mechanical Properties in Standard Test Specimens and Injection Molded Thin-Wall Parts
Authors: Sandu Laurentiu I. , Stan Felicia , Fetecau Catalin
Published: November 2013

In this paper, we investigated the effect of injection molding parameters on the mechanical properties of thin-wall injection molded parts. A four-factor (melt temperature, mold temperature, injection speed and packing pressure) and three-level fractional experimental design was performed to investigate the influence of each factor on the mechanical properties and determine the optimal process conditions that maximize the mechanical properties of the part using the signal-to-noise (S/N) ratio response. The mechanical properties (e.g., elastic modulus, yield strength and strain at break) were measured by tensile tests at room temperature, at a crosshead speed of 5 mm/min, and compared with those of the injection-molded specimens.

The experimental results showed that the tensile properties were highly dependent on the injection molding parameters, regardless of the type of the specimens. The values of Young modulus and yield strength of the injection-molded specimens were lower than those of the injection-molded parts, while the elongation at break was considerably lower for the injection-molded parts. The optimal process conditions were strongly dependent on the measured performance quantities (elastic modulus, yield strength and strain at break).
Correlating Acoustic Emission to Calibration Phenomena for Possible Measurement Standard
Authors: Griffin James
Published: November 2013

When using Acoustic Emission (AE) technologies, tensile and compressive tests can provide a detector for material deformation. In this paper improvements are made to standardise calibration techniques. AE signatures were evaluated from various calibration sources based on the energy from the first harmonic (dominant energy band) [1][2]. The work presented here provides further, valuable knowledge to both the manufacturing and structural health monitoring research communities. The effects of AE against its calibration identity are investigated: where signals are correlated to the average energy and distance of the detected phenomena. Five sources of calibration would be required in order to calculate an average amount. AE evaluated by a Neural Network (NN) regression classification technique identifies how far the malformation has progressed (in terms of energy/force) during material transformation. A genetic-fuzzy-c-clustering classifier was used as the 2nd classification technique to verify the classifications of the NN. This calibration method can be used for legislation purposes when either machining or operating. In summary this paper presents a new method of AE calibration through the correlation of AE and force/distance measurements.
Virtualize Manufacturing Capabilities in the Cloud: Requirements and Architecture
Authors: Wang Xi Vincent , Xu Xun W.
Published: November 2013

In recent years, Cloud Manufacturing concept has been proposed by taking advantage of Cloud Computing to improve the performance of manufacturing industry. Cloud Manufacturing attempts can be summarized as two sectors, i.e. manufacturing version of Computing Cloud, and a distributed environment that is networked around Manufacturing Cloud. In this paper, manufacturing resource, ability and relevant essentials are discussed in the service-oriented perspective. The functional requirements of a Cloud Manufacturing environment are discussed, along with an interoperable manufacturing system framework. Cloud resource integration models are developed that are compliant with existing international standards. It is possible to achieve a collaborative, intelligent, and distributed environment via Cloud Manufacturing technologies.
Application of Laser in Joining Aluminum Foam Hybrid Materials
Authors: Ascari Alessandro , Campana Giampaolo
Published: November 2013

This article illustrates an experimental campaign aimed at assessing preliminary guidelines for the application of the laser in joining cellular-structured hybrid materials. In particular the target specimens exploited were all characterized by the presence of an aluminum foam core and by an external skin, made in aluminum or in stainless steel. The goal of the present paper is to underline a global feasibility of laser joining of these materials pointing out the role of the main process parameters and to suggest some original techniques which could be adopted in order to improve the overall quality of the joint. The experience described pointed out that, when dealing with this kind of materials, the role of the laser can be dual: in case of high energy density applications it can be used for local fusion of the workpiece, as in traditional welding, while in low energy density ones the radiation can be exploited as a controlled heating source for promoting local thermal actions particularly on the cellular portion of the material.
Analytical Modeling and Experimental Validation of Force Ripple and Friction Force for General Direct Drive Systems
Authors: Zhao Ran , Xu Chengying
Published: November 2013

In this paper, we present a systematic modeling method of direct drive systems. Experiments are designed to decouple and model friction and force ripple separately, which are two major sources of tracking error. Three different optimization methods, least square method, nonlinear least square method and particle swarm optimization are used for parameter optimization. The analytical form of the model makes it easy to use in engineering practices. All results are obtained and verified experimentally. The method presented in this paper can also be used to model other mechanical systems.
Chip Segmentation in Machining: A Study of Deformation Localization Characteristics in Ti6Al4V
Authors: Chandra Abhijit , Karra Pavan , Bragg Adam , Wang Jie , Kim Gap Yong
Published: November 2013

Chip segmentation by deformation localization is an important process in a certain range of velocities and might be desirable in reducing cutting forces and by improving chips’ evacuation, whereas few studies of practical criteria to calculate shear band spacing are available in literature. This paper extends nonlinear dynamics model for chip segmentation by allowing time varying orientation of the shear plane that are pronounced in strain hardening materials. The model extends the non-linear dynamics approach with additional state variables to the Burns and Davies approach. The model is simulated numerically to predict the shear bands of the chip. The numerical simulation of the model is compared with experimental observations and is in agreement with experimental observations in Ti6Al4V. This offers guidance to predict shear band spacing of other materials.
Effect of Mechanical Alloying on Al6061-Graphene Composite Fabricated by Semi-Solid Powder Processing
Authors: Bastwros Mina , Kim Gap-Yong , Zhu Can , Zhang Kun , Wang Shiren
Published: November 2013

Graphene is a promising material as a reinforcing element for high-strength, lightweight metal composites due to its extraordinary mechanical properties and low density. In this study, Al6061–graphene composite was investigated with 1.0 wt.% graphene reinforcement. The graphene was manufactured by the modified Brodie’s method. The Al6061 powder and graphene flakes were ball milled at different milling times (10, 30, 60, and 90 min). The composite was then synthesized by hot compaction in the semi-solid regime of the Al6061. Three point bending test was performed to characterize the mechanical properties of the composites. The ball milled powder and the fracture surfaces of the composites were investigated using the scanning electron microscopy (SEM). The results were compared with a reference Al6061 without any graphene reinforcement. For the Al6061-1.0 wt.% graphene composites, a maximum enhancement of 47% in the flexural strength was observed when compared with the reference Al6061 processed at the same condition.
Key Technologies of Embedded Gear Machining CNC System
Authors: Han Jiang , Tian Xiao-qing , Xia Lian , Li Fu-gen , Cheng Jie , Chen Bao
Published: November 2013

A reconfigurable gear machining numerical control system (NC/CNC) architecture is proposed in this paper. The CNC platform can be quickly applied to gear hobbing, shaping, milling and grinding machine, through simple reconfiguring or parameter setting. Parametric automatic programming technology, high speed and high precision electronic gearbox, process database technology are studied. Based on the analysis of the gear machining process, the mathematic model on automatic programming of gear machining is established. Based on the Windows CE operating system, the CNC gear machining automatic programming system is developed on the ARM+DSP hardware platform, including the design of human-machine interface, automatic programming algorithm and other modules. With the support of the automatic programming and process database modules, NC codes can be generated automatically just by inputting gear parameters, tool parameters and process parameters, then, the interpolation data structure can be generated by interpreter module. A new kind of software electronic gearbox (EGB) and its implementation methods are also researched in the embedded CNC. Data flow among the modules is analyzed. Finally, experiments are conducted, and the tracking error and contour error are analyzed. The results show that the proposed gear machining CNC architecture is effective.
Simulation and Experiment on Warm Hydroforming of AZ31 Magnesium Alloy Tube
Authors: Yuan Shijian , Tang Zejun , Liu Gang
Published: November 2013

The wrinkling behavior of an AZ31B magnesium alloy tube was investigated by simulation at different loading paths and at different temperatures. The effects of strain rate, internal pressure and temperature on the wrinkles were studied. Stressstrain track was analyzed in the quasi-static strain state graph of the plane stress processing to explain the changing of the wrinkles’ shape, radius and wall thickness. It is shown that shape of the wrinkles wave along the axial direction keeps the sine wave character. The radius and thinning at the top zone of the wrinkles and the width of the wrinkles increased with the temperature, the internal pressure or the axial feeding. Moreover, hydro-formability of wrinkled parts was investigated and the improvement was observed. Finnally, as an application of using wrinkled parts as preform prior to the final calibration, a magnesium alloy tubular part with 50% expansion ratio was formed.
Measuring Dynamic 3D Micro-Structures Using a Superfast Digital Binary Phase-Shifting Technique
Authors: Zhang Song , Wang Yajun , Laughner Jacob I. , Efimov Igor R.
Published: November 2013

Binary phase-shifting in digital fringe projection has demonstrated significant merit over conventional sinusoidal phases-shifting methods in terms of measurement speed and simplicity. This paper will show that compared to conventional sinusoidal methods, binary defocusing 1) can better resolve 3D micro-structures; and 2) can achieve kilo-Hz 3D shape measurement rates. These features are critical for measuring dynamically deformable objects, such as the beating heart.