bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between Plasma Fibroblast Growth Factor‐23 Concentration and Survival Time in Cats with Chronic Kidney Disease
Authors: Geddes R.F. , Elliott J. , Syme H.M.
Published: September 2015

Background

Fibroblast growth factor‐23 (FGF‐23) and parathyroid hormone (PTH) are commonly increased in cats with azotemic chronic kidney disease (CKD). Both are predictors of survival time in human patients, but these relationships have not previously been examined in the cat.

Objectives

To investigate the relationship between plasma FGF‐23 and PTH concentrations at diagnosis of CKD in cats with survival time and with disease progression over 12 months.

Animals

214 azotemic, client‐owned cats (≥9 years).

Methods

Retrospective study: Biochemical and urinary variables at diagnosis of azotemic CKD, including plasma FGF‐23 and PTH concentrations were assessed as predictors of survival time (all‐cause mortality) using Cox regression, and as predictors of CKD progression over 12 months using logistic regression.

Results

In the final multivariable Cox regression model, survival was negatively associated with plasma creatinine (P = .002) and FGF‐23 concentrations (P = .014), urine protein‐to‐creatinine ratio (P < .001) and age (P < .001). Survival was positively associated with PCV (P = .004). In the final multivariable logistic regression model, independent predictors of CKD progression included logFGF‐23 and age. Neither plasma phosphate nor PTH was found to be an independent predictor of survival time or of CKD progression.

Conclusions and Clinical Importance

Plasma FGF‐23 concentration is a novel prognostic indicator in cats with CKD, independent of other factors including plasma creatinine and phosphate concentrations. Further work is required to assess if FGF‐23 contributes directly to CKD progression, but regardless these findings may make FGF‐23 a useful biomarker for predicting poorer outcomes in cats with CKD.
Stackelberg Competition, Innovation and Social Efficiency of Entry
Authors: Chao Angela C. , Lee Jen‐yao , Wang Leonard F.S.
Published: September 2015

In literature, the common wisdom is that entry in an industry with homogeneous products may be socially insufficient instead of excessive in the absence of scale economies. In this paper, we formally introduce endogenous research and development (R&D) and cost asymmetry into both Cournot and Stackelberg competition, and show that entry is socially insufficient in the presence of ex ante asymmetric costs coupled with the spillover effect of R&D.
Population genetic structure of a common host predicts the spread of white‐nose syndrome, an emerging infectious disease in bats
Authors: Wilder Aryn P. , Kunz Thomas H. , Sorenson Michael D.
Published: September 2015

Landscape complexity influences patterns of animal dispersal, which in turn may affect both gene flow and the spread of pathogens. White‐nose syndrome (WNS) is an introduced fungal disease that has spread rapidly throughout eastern North America, causing massive mortality in bat populations. We tested for a relationship between the population genetic structure of the most common host, the little brown myotis (Myotis lucifugus), and the geographic spread of WNS to date by evaluating logistic regression models of WNS risk among hibernating colonies in eastern North America. We hypothesized that risk of WNS to susceptible host colonies should increase with both geographic proximity and genetic similarity, reflecting historical connectivity, to infected colonies. Consistent with this hypothesis, inclusion of genetic distance between infected and susceptible colonies significantly improved models of disease spread, capturing heterogeneity in the spatial expansion of WNS despite low levels of genetic differentiation among eastern populations. Expanding our genetic analysis to the continental range of little brown myotis reveals strongly contrasting patterns of population structure between eastern and western North America. Genetic structure increases markedly moving westward into the northern Great Plains, beyond the current distribution of WNS. In western North America, genetic differentiation of geographically proximate populations often exceeds levels observed across the entire eastern region, suggesting infrequent and/or locally restricted dispersal, and thus relatively limited opportunities for pathogen introduction in western North America. Taken together, our analyses suggest a possibly slower future rate of spread of the WNS pathogen, at least as mediated by little brown myotis.
Candida and cardiovascular implantable electronic devices: a case of lead and native aortic valve endocarditis and literature review
Authors: Glavis‐Bloom Justin , Vasher Scott , Marmor Meghan , Fine Antonella B. , Chan Philip A. , Tashima Karen T. , Lonks John R. , Kojic Erna M.
Published: September 2015

Use of cardiovascular implantable electronic devices (CIED), including permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), has increased dramatically over the past two decades. Most CIED infections are caused by staphylococci. Fungal causes are rare and their prognosis is poor. To our knowledge, there has not been a previously reported case of multifocal Candida endocarditis involving both a native left‐sided heart valve and a CIED lead. Here, we report the case of a 70‐year‐old patient who presented with nausea, vomiting, and generalised fatigue, and was found to have Candida glabrata endocarditis involving both a native aortic valve and right atrial ICD lead. We review the literature and summarise four additional cases of CIED‐associated Candida endocarditis published from 2009 to 2014, updating a previously published review of cases prior to 2009. We additionally review treatment guidelines and discuss management of CIED‐associated Candida endocarditis.
Molecular types of Cryptococcus gattii/Cryptococcus neoformans species complex from clinical and environmental sources in Nairobi, Kenya
Authors: Kangogo Mourine , Bader Oliver , Boga Hamadi , Wanyoike Wanjiru , Folba Claudia , Worasilchai Navaporn , Weig Michael , Groß Uwe , Bii Christine C.
Published: September 2015

Cryptococcal meningitis infections cause high mortality rates among HIV‐infected patients in Sub‐Saharan Africa. The high incidences of cryptococcal infections may be attributed to common environmental sources which, if identified, could lead to institution of appropriate control strategies. To determine the genotypes of Cryptococcus gattii/C. neoformans‐ species complex from Nairobi, Kenya, 123 clinical and environmental isolates were characterised. Typing was done using orotidine monophosphate pyrophosphorylase (URA5) gene restriction fragment length polymorphism (URA5‐RFLP). The majority of the isolates [105/123; 85.4%] were C. neoformans genotype (AFLPI/VNI) and 1.6% AFLP1A/VNB/VNII, whereas (13%) were C. gattii (AFLP4/VGI). This is the first report on the genotypes of C. gattii/C. neoformans species complex from clinical and environmental sources in Nairobi, Kenya and the isolation of C. gattii genotype AFLP4/VGI from the environment in Kenya.
Abnormal regional homogeneity in patients with irritable bowel syndrome: A resting‐state functional MRI study
Authors: Ke J. , Qi R. , Liu C. , Xu Q. , Wang F. , Zhang L. , Lu G.
Published: September 2015

Background

Task‐related brain imaging research has implicated abnormal central processing of visceral sensation in irritable bowel syndrome (IBS). However, how brain function of IBS patients is altered during resting‐state remains to be determined. We investigated spontaneous brain activity of patients with IBS using regional homogeneity (ReHo) analysis in resting‐state functional magnetic resonance imaging (rs‐fMRI).

Methods

Thirty‐one patients with diarrhea‐predominant IBS and 32 age‐ and sex‐ matched healthy controls underwent clinical assessments and rs‐fMRI scanning. ReHo maps were acquired by calculating the Kendall's coefficient of concordance and compared between the IBS group and the control group. The effects of psychological disturbance on group differences were assessed by including anxiety and depression levels as covariates in the statistical analyses. Multiple regression analyses were conducted to examine the relationship between ReHo values and disease duration, symptom severity, and pain intensity.

Key Results

Compared with controls, IBS patients showed increased ReHo in the postcentral gyrus and thalamus and decreased ReHo in the anterior cingulate cortex and prefrontal cortex. The inclusion of anxiety and depression as covariates did not alter ReHo differences between the two groups. Furthermore, significant correlations were found between clinical indices and ReHo values in some brain regions in the IBS group.

Conclusions & Inferences

IBS patients have abnormal local synchronization of spontaneous brain activity in regions involved in visceral afferent processing, emotional arousal, and cognitive modulation. Combining rs‐fMRI and ReHo analysis seems to be a valuable approach to investigate the neural basis of IBS.
Peroxisome proliferator‐activated receptor δ inhibits Porphyromonas gingivalis lipopolysaccharide‐induced activation of matrix metalloproteinase‐2 by downregulating NADPH oxidase 4 in human gingival fibroblasts
Authors: Yoo T. , Ham S.A. , Hwang J.S. , Lee W.J. , Paek K.S. , Oh J.W. , Kim J.H. , Do J.T. , Han C.W. , Kim J.H. , Seo H.G.
Published: September 2015

We investigated the roles of peroxisome proliferator‐activated receptor δ (PPARδ) in Porphyromonas gingivalis‐derived lipopolysaccharide (Pg‐LPS)‐induced activation of matrix metalloproteinase 2 (MMP‐2). In human gingival fibroblasts (HGFs), activation of PPARδ by GW501516, a specific ligand of PPARδ, inhibited Pg‐LPS‐induced activation of MMP‐2 and generation of reactive oxygen species (ROS), which was associated with reduced expression of NADPH oxidase 4 (Nox4). These effects were significantly smaller in the presence of small interfering RNA targeting PPARδ or the specific PPARδ inhibitor GSK0660, indicating that PPARδ is involved in these events. In addition, modulation of Nox4 expression by small interfering RNA influenced the effect of PPARδ on MMP‐2 activity, suggesting a mechanism in which Nox4‐derived ROS modulates MMP‐2 activity. Furthermore, c‐Jun N‐terminal kinase and p38, but not extracellular signal‐regulated kinase, mediated PPARδ‐dependent inhibition of MMP‐2 activity in HGFs treated with Pg‐LPS. Concomitantly, PPARδ‐mediated inhibition of MMP‐2 activity was associated with the restoration of types I and III collagen to levels approaching those in HGFs not treated with Pg‐LPS. These results indicate that PPARδ‐mediated downregulation of Nox4 modulates cellular redox status, which in turn plays a critical role in extracellular matrix homeostasis through ROS‐dependent regulation of MMP‐2 activity.
Association mapping and resistant alleles’ analysis for japonica rice blast resistance
Authors: Guo Liying , Guo Wei , Zhao Hongwei , Wang Jingguo , Liu Hualong , Sun Jian , Zheng Hongliang , Sha Hanjing , Zou Detang
Published: September 2015

Rice blast is one of the major fungal diseases that badly reduce rice production in China and worldwide. Association mapping for blast resistance was performed on 226 japonica rice cultivars with 118 pairs of SSR markers. The blast resistance was evaluated by inoculating with two isolates, DB22 and DB77, at the tillering stage in 2013 and 2014, separately. A total of 31 associations with 17 different SSRs were significantly (P < 0.05) associated with blast resistance based on the mixed linear model (MLM), of which nine markers could be detected in both 2013 and 2014, including two markers that were simultaneously associated with the two isolates. Five of the nine stable markers were consistent with the genome regions identified by linkage mapping in previous reports. Phenotypic effects of each allele of the nine stable markers were compared, and 18 favourable alleles were identified. Five elite parental combinations were designed for improving blast resistance in rice. Our results demonstrate that association mapping can complement and enhance previous QTL information for marker‐assisted selection and breeding by design.
Clostridium difficile infection in the pediatric transplant patient
Authors: Nicholson Maribeth R. , Osgood Christy L. , Acra Sari A. , Edwards Kathryn M.
Published: September 2015

CDIs are on the rise in both hospital and community settings in adults and children. Children with cancer or a history of HSCT or SOT appear to be at higher risk for primary disease, recurrent disease, and severe outcomes when compared to children with other comorbidities. The reasons for this are not clear and no studies to date have analyzed risk factors for CDI in pediatric transplant patients. Colonization rates in children with cancer and a transplant history are also high. Determining which children are colonized with Clostridium difficile and symptomatic from another source vs. symptomatic from CDI is difficult and a clinical conundrum for the transplant physician. The use of fecal transplantation for severe or rCDI is likely safe and effective in the immunosuppressed pediatric cancer or transplant patient, but this will need to be more thoroughly studied in this patient population.
Social Factors Related to Smoking among Rural, Low‐Income Women: Findings from a Systematic Review
Authors: Mitchell Star A. , Kneipp Shawn M. , Giscombe Cheryl W.
Published: September 2015

Objective

This systematic review of the literature assesses congruency of findings from descriptive, qualitative, and association studies focusing on factors influencing smoking and smoking cessation with findings from smoking cessation interventions that included low‐income rural women.

Design and Sample

Six databases relevant to the health and social sciences were searched in this systematic review using combinations of select keyword terms, specific inclusion criteria, and studies between 1997 and 2012.

Results

Descriptive studies on this population of smokers provide economic, environmental, and social factors related to smoking patterns. Qualitative studies found social support received from an individual's social network was viewed as most beneficial when considering or maintaining smoking cessation while randomized controlled trials included in this review implemented social support through peripheral resources or resources with little personal connection to the sample and failed to produce significant results.

Conclusions

Few studies have focused on the specific needs and difficulties of smoking cessation among rural low‐income women and interventions have not targeted the complex social network of this population. Incongruence in study findings supports the need for smoking assessment and cessation interventions that incorporates the unique social and cultural meanings of smoking in rural low‐income women.
Modification of flower colour by suppressing β‐ring carotene hydroxylase genes in Oncidium
Authors: Wang H.‐M. , To K.‐Y. , Lai H.‐M. , Jeng S.‐T.
Published: September 2015

Oncidium ‘Gower Ramsey’ (Onc. GR) is a popular cut flower, but its colour is limited to bright yellow. The β‐ring carotene hydroxylase (BCH2) gene is involved in carotenoid biogenesis for pigment formation. However, the role of BCH2 in Onc. GR is poorly understood. Here, we investigated the functions of three BCH2 genes, BCH‐A2, BCH‐B2 and BCH‐C2 isolated from Onc. GR, to analyse their roles in flower colour. RT‐PCR expression profiling suggested that BCH2 was mainly expressed in flowers. The expression of BCH‐B2 remained constant while that of BCH‐A2 gradually decreased during flower development. Using Agrobacterium tumefaciens to introduce BCH2 RNA interference (RNAi), we created transgenic Oncidium plants with down‐regulated BCH expression. In the transgenic plants, flower colour changed from the bright yellow of the wild type to light and white‐yellow. BCH‐A2 and BCH‐B2 expression levels were significantly reduced in the transgenic flower lips, which make up the major portion of the Oncidium flower. Sectional magnification of the flower lip showed that the amount of pigmentation in the papillate cells of the adaxial epidermis was proportional to the intensity of yellow colouration. HPLC analyses of the carotenoid composition of the transgenic flowers suggested major reductions in neoxanthin and violaxanthin. In conclusion, BCH2 expression regulated the accumulation of yellow pigments in the Oncidium flower, and the down‐regulation of BCH‐A2 and BCH‐B2 changed the flower colour from bright yellow to light and white‐yellow.
Light compensation points in shade‐grown seedlings of deciduous broadleaf tree species with different successional traits raised under elevated CO2
Authors: Kitao M. , Hida T. , Eguchi N. , Tobita H. , Utsugi H. , Uemura A. , Kitaoka S. , Koike T.
Published: September 2015

We measured leaf photosynthetic traits in shade‐grown seedlings of four tree species native to northern Japan, raised under an elevated CO2 condition, to investigate the effects of elevated CO2 on shade tolerance of deciduous broadleaf tree species with different successional traits. We considered Betula platyphylla var. japonica and Betula maximowicziana as pioneer species, Quercus mongolica var. crispula as a mid‐successional species, and Acer mono as a climax species. The plants were grown under shade conditions (10% of full sunlight) in a CO2‐regulated phytotron. Light compensation points (LCPs) decreased in all tree species when grown under elevated CO2 (720 μmol·mol−1), which were accompanied by higher apparent quantum yields but no photosynthetic down‐regulation. LCPs in Q. mongolica and A. mono grown under elevated CO2 were lower than those in the two pioneer birch species. The LCP in Q. mongolica seedlings was not different from that of A. mono in each CO2 treatment. However, lower dark respiration rates were observed in A. mono than in Q. mongolica, suggesting higher shade tolerance in A. mono as a climax species in relation to carbon loss at night. Thus, elevated CO2 may have enhanced shade tolerance by lowering LCPs in all species, but the ranking of shade tolerance related to successional traits did not change among species under elevated CO2, i.e. the highest shade tolerance was observed in the climax species (A. mono), followed by a gap‐dependent species (Q. mongolica), while lower shade tolerance was observed in the pioneer species (B. platyphylla and B. maximowicziana).
Unravelling the mechanisms for plant survival on gypsum soils: an analysis of the chemical composition of gypsum plants from Turkey
Authors: Bolukbasi A. , Kurt L. , Palacio S.
Published: September 2015

Depending on their specificity to gypsum, plants can be classified as gypsophiles (gypsum exclusive) and gypsovags (non‐exclusive). The former may further be segregated into wide and narrow gypsophiles, depending on the breadth of their distribution area. Narrow gypsum endemics have a putative similar chemical composition to plants non‐exclusive to gypsum (i.e. gypsovags), which may indicate their similar ecological strategy as stress‐tolerant plant refugees on gypsum. However, this hypothesis awaits testing in different regions of the world. We compared the chemical composition of four narrow gypsum endemics, one widely distributed gypsophile and six gypsovags from Turkey. Further, we explored the plasticity in chemical composition of Turkish gypsovags growing on high‐ and low‐gypsum content soils. Differences were explored with multivariate analyses (RDA) and mixed models (REML). Narrow gypsum endemics segregated from gypsovags in their chemical composition according to RDAs (mainly due to higher K and ash content in the former). Nevertheless, differences were small and disappeared when different nutrients were analysed individually. All the gypsovags studied accumulated more S and ash when growing on high‐gypsum than on low‐gypsum soils. Similar to narrow gypsum endemics from other regions of the world, most local gypsum endemics from Turkey show a similar chemical composition to gypsovags. This may indicate a shared ecological strategy as stress‐tolerant plants not specifically adapted to gypsum. Nevertheless, the narrow gypsum endemic Gypsophila parva showed a chemical composition typical of gypsum specialists, indicating that various strategies are feasible within narrowly distributed gypsophiles.
Influence of Body Condition on Serum Metabolic Indicators of Lipid Mobilization and Oxidative Stress in Dairy Cows During the Transition Period
Authors: Folnožić I , Turk R , Đuričić D , Vince S , Pleadin J , Flegar–Meštrić Z , Valpotić H , Dobranić T , Gračner D , Samardžija M
Published: September 2015

Contents

The objectives of this study were to examine the influence of body condition of cows on metabolic and antioxidative status, as well as to investigate the relationship between metabolic indicators of lipid mobilization and oxidative stress during transition period. The study was conducted on 24 Holstein‐Friesian dairy cows divided into 2 groups according to their body condition score (BCS) as optimal (n = 12; BCS from 3.25 to 3.75) or adipose (n = 12; BCS ≥4). Metabolic status (glucose, triglycerides, total cholesterol, HDL cholesterol, NEFA and BHB), paraoxonase‐1 (PON1) and apolipoprotein A‐I (ApoA‐I) were analysed in sera taken on days −30, −10, −2, 0, 5, 12, 19, 26 and 60 relative to parturition. Adipose cows had significantly higher glucose concentration at parturition being significantly decreased after parturition on days 12 and 19. Total cholesterol and HDL‐C concentrations were the lowest at parturition and significantly higher on days 26 and 60 after parturition in both groups of cows. Both investigated groups had significantly higher NEFA concentration from parturition until day 19 after parturition, indicating energy deficit and an increased lipid mobilization after calving. There were no significant differences in BHB concentration during transition period in both groups. No significant differences were found in PON1 activity and ApoA‐I concentration during transition period in both groups of cows. However, in adipose cows, although not significantly different, PON1 was decreased from calving until day 19 after parturition indicating a disturbance in antioxidative status in adipose cows. PON1 significantly positively correlated with total cholesterol and HDL‐C concentrations and negatively with NEFA indicating a strong relationship of PON1 with lipid metabolism. Significant positive correlation between NEFA and BHB in both groups of cows points out on energy deficit during transition period that cows tend to overcome by lipid mobilization providing alternative source of energy needed for parturition and lactation.
The Willingness to State an Opinion: Inequality, Don't Know Responses, and Political Participation
Authors: Laurison Daniel
Published: September 2015

Most explanations of inequality in political participation focus on costs or other barriers for those with fewer economic, educational, and “cognitive” resources. I argue, drawing on Pierre Bourdieu's work on “political competence,” that social position in the form of income also structures political participation through differences in the sense that one is a legitimate producer of political opinions. I test whether income differences in participation persist net of costs by examining nonparticipation in a setting in which barriers to participation are low: answering political survey questions. Lower‐income people are more likely than others to withhold political opinions by saying “don't know” net of differences in education, “cognitive ability,” or engagement with the survey exercise. Further, political “don't know” rates predict voting rates, net of other predictors. Efforts to democratize participation in American politics must attend not only to the costs of involvement but also to class‐based differences in individuals' relationship to political expression itself.
Biologically inspired skin lesion segmentation using a geodesic active contour technique
Authors: Kasmi R. , Mokrani K. , Rader R. K. , Cole J. G. , Stoecker W. V.
Published: September 2015

Background/Purpose

Computer‐aided diagnosis of skin cancer requires accurate lesion segmentation, which must overcome noise such as hair, skin color variations, and ambient light variability.

Methods

A biologically inspired geodesic active contour (GAC) technique is used for lesion segmentation. The algorithm presented here employs automatic contour initialization close to the actual lesion boundary, overcoming the ‘sticking’ at minimum local energy spots caused by noise artifacts such as hair. The border is significantly smoothed to mimic natural lesions. In addition, features that mimic biological parameters include spectral image subtraction and removal of peninsulas and inlets. Multiple boundary choices borders are created by parameter options used at different steps. These choices can allow future improvement over the basic default border.

Results

The basic GAC algorithm was tested on 100 images (30 melanomas and 70 benign lesions), yielding a median XOR border error of 6.7%, comparable to the median inter‐dermatologist XOR border error (7.4%), and lower than the gradient vector flow snake median XOR error of 14.2% on the same image set. On a difficult low‐contrast border set of 1238 images, which included 350 non‐melanocytic lesions, a median XOR error of 23.9% is obtained.

Conclusion

GAC techniques show promise in attaining the goal of automatic skin lesion segmentation.
Characterization of the novel HLA‐C*08:01:09 allele identified in a Chinese Han individual
Authors: Wang D.‐M.
Published: September 2015

HLA‐C*08:01:09 allele differs from HLA‐C*08:01:01 at nt735 C>T in exon 4.
The Sec2 translocase of the chloroplast inner envelope contains a unique and dedicated SECE2 component
Authors: Li Yubing , Singhal Rajneesh , Taylor Isaiah W. , McMinn Patrick H. , Chua Xien Yu , Cline Kenneth , Fernandez Donna E.
Published: September 2015

Biogenesis of chloroplasts involves a series of protein trafficking events. Nuclear‐encoded proteins are imported into the organelle, and then trafficked to various chloroplast locations by systems that are directly homologous to bacterial systems. Although the thylakoid‐based systems have been studied extensively, much less is known about the systems that reside and function in the inner envelope membrane. One such system, the Sec2 system, is homologous to both the thylakoid‐based Sec1 system and bacterial Sec systems, and may mediate both integration and translocation across the inner envelope. At a minimum, this system is expected to include three components, but only two, SCY2 and SECA2, have been identified in Arabidopsis. Bioinformatics and protein modeling were used to identify the protein encoded by At4g38490 as a candidate for the missing component (SECE2). Cellular localization, biochemistry, protein interaction assays in yeast, and co‐immunoprecipitation experiments were used to establish that this protein is an integral membrane protein of the inner envelope, and specifically interacts with the SCY2 component in vivo. Sequence analyses indicated that SECE2 proteins are found in a variety of plants, and differ from the thylakoid SECE1 proteins in a stroma‐exposed helical domain, which may contribute to their specificity. Finally, a genetic analysis indicated that SECE2 plays an essential role in plant growth and development.
Vps33B is required for delivery of endocytosed cargo to lysosomes
Authors: Galmes Romain , ten Brink Corlinda , Oorschot Viola , Veenendaal Tineke , Jonker Caspar , van der Sluijs Peter , Klumperman Judith
Published: September 2015

Lysosomes are the main degradative compartments of eukaryotic cells. The CORVET and HOPS tethering complexes are well known for their role in membrane fusion in the yeast endocytic pathway. Yeast Vps33p is part of both complexes, and has two mammalian homologues: Vps33A and Vps33B. Vps33B is required for recycling of apical proteins in polarized cells and a causative gene for ARC syndrome. Here, we investigate whether Vps33B is also required in the degradative pathway. By fluorescence and electron microscopy we show that Vps33B depletion in HeLa cells leads to significantly increased numbers of late endosomes that together with lysosomes accumulate in the perinuclear region. Degradation of endocytosed cargo is impaired in these cells. By electron microscopy we show that endocytosed BSA‐gold reaches late endosomes, but is decreased in lysosomes. The increase in late endosome numbers and the lack of internalized cargo in lysosomes are indicative for a defect in late endosomal–lysosomal fusion events, which explains the observed decrease in cargo degradation. A corresponding phenotype was found after Vps33A knock down, which in addition also resulted in decreased lysosome numbers. We conclude that Vps33B, in addition to its role in endosomal recycling, is required for late endosomal–lysosomal fusion events.
Hot Gas Forming for Advanced Tubular Automobile Components: Opportunities and Challenges
Authors: Landgrebe Dirk , Schieck Frank
Published: September 2015

Today most industrial sectors are faced with several challenges such as the reduction of CO2 emission, the shortage of resources and the increasing individualization of products. This situation particularly appears in the automotive industry. To reduce CO2 emission of cars there is no alternative to decreasing weight. Advanced lightweight design implies new materials, innovative component design and finally new production methods. Based on this not only the CO2 emission during the operation phase becomes a focus, also the manufacturing process becomes more and more important.

Following upcoming requests for lightweight materials, new design principles and energy and resource efficient production processes, conventional forming technologies are reaching their limits. By including temperature as an active temperature parameter into the production process, advanced final component properties are possible, forming limits can be extended and process chains can be shortened.

This is valid particularly for hydroforming. Advantages and disadvantages of this technology are well known, and today there are a few typical automotive components in series production. Compared to a blank half shell design of car components, hydroformed profiles allow a flangeless design, the reduction of individual parts in a component and an excellent degree of material utilization. To implement high temperatures into this technology, alternative heat-resistant forming media are mandatory. The substitution of water by nitrogen increases the thermal process limits up to 1,000°C, but this also requires new systems engineering.

This paper gives an overview on the development of hot gas forming technology and illustrates prospects and limits by means of automotive-related parts for metallic lightweight materials such as ultra-high strength and stainless steel, Aluminum or Magnesium. Beside the determination of temperature-related material characteristics, the research focused on process and tool design based on thermo-mechanically coupled FE simulation. The consecutive manufacturing of prototyping parts allows the validation of simulation results and assesses the prospects to shorten existing process chains in the future.
Advances in Plastic Anisotropy and Forming Limits in Sheet Metal Forming
Authors: Banabic Dorel
Published: September 2015

In the last decades, numerical simulation has gradually extended its applicability in the field of sheet metal forming. Constitutive modelling and formability are two domains closely related to the development of numerical simulation tools. This paper is focused, on the one hand, on the presentation of new phenomenological yield criteria developed in the last decade, which are able to describe the anisotropic response of sheet metals, and, on the other hand, on new models and experiments to predict/determine the forming limit curves.
Reducing Costs in the Manufacturing Industry: An Energy Economic Perspective
Authors: Brundage Michael P. , Chang Qing , Arinez Jorge , Xiao Guoxian
Published: September 2015

Manufacturers lack the proper economic tools to improve energy efficiency of the plant. This paper uses energy economic analysis to increase the overall profit of the manufacturing facility by reducing energy consumption with minimal throughput impact. A return on investment strategy is developed to give plant managers the quantitative tools to select the machine which, when replaced, will lead to the largest return on investment. Over the long term, this will lead to the largest decrease in energy costs. To increase profits on a daily basis, a control methodology is developed that uses energy opportunity windows to insert downtime events that have minimal production impact, but reduce the overall energy consumption. A simulation case study is performed to test the control methodology and the return on investment strategy to show the effect of both on the profit of the manufacturing facility.
Rotary Ultrasonic Machining of CFRP: Design of Experiment With a Cutting Force Model
Authors: Ning Fuda , Cong Weilong
Published: September 2015

Drilling is one of very important machining processes in many applications of carbon fiber reinforced plastic (CFRP) composites. Rotary ultrasonic machining (RUM) has been successfully used in drilling of CFRP composites to overcome poor machinability. Cutting force is one of the most important output variables for evaluating drilling process, since it will greatly influence cutting temperature, tool wear, and surface conditions. Currently, there are no reported investigations on effect of input variables on cutting force using design of experiment (DOE) method in RUM of CFRP composites. Five-variable two-level full factorial design has been conducted to study cutting force based on a mechanistic predictive model in RUM of CFRP composites. Main effects as well as interaction effects of five process variables (vibration amplitude, tool rotation speed, feedrate, abrasive size, and abrasive concentration) on cutting force are revealed.
Thermodynamic Analysis of Titanium Dioxide Nanotube Synthesis Process for Sustainability Improvement
Authors: Li Bingbing , Zhang Hong-Chao , Yuan Chris
Published: September 2015

Sustainability of nanomanufacturing has triggered tremendous research interest in recent years, especially the energy consumption and environmental impacts of nanomaterial. TiO2 nanotube is a typical material with broad application potential. In this paper a thermodynamic analysis model integrating the energy consumption and exergy losses is presented for sustainability improvement of TiO2 nanotube synthesis process. This thermodynamic model was validated by the TiO2 nanotube electrochemical anodization process. Comparisons of energy consumption, exergy losses and environmental impacts of five main stages showed the effective sustainability improvement potential. This work can be extended to sustainability improvement of other similar nanomaterial synthesis processes.
Virtual Test Field for Sustainability Assessment of Cybertronic Production Systems
Authors: Ilsen Rebecca , Meissner Hermann , Aurich Jan C.
Published: September 2015

Studying the goals, ideas and trends of the concept of cybertronic production systems (CTPS) leads to the hypothesis that CTPS supports a sustainable development. The paper proposes an approach for simulating and verifying this hypothesis.

Cybertronic production systems are formed by the application of cybertronic systems (CTS) in production. To examine the behavior of cybertronic systems depending on their level of interconnection, intelligence and independence a multi-agent system of a production system is implemented. This simulation system can be used as virtual test field to evaluate impacts of changes in the production system on all level of detail (process, machine tool, factory level) by using sustainability indicators on factory level.
Tuning the Mechanical Properties of High-Density Polyethylene by ECAE Process
Authors: Fetecau Catalin , Stan Felicia , Sandu Laurentiu , Susac Florin
Published: September 2015

This paper investigates the ability of the equal channel angular extrusion (ECAE) process to induce morphological changes and hence tune the mechanical properties of high-density polyethylene (HDPE). In this study, differential scanning calorimetry (DSC), compression and cylindrical macro-indentation tests have been used to investigate the evolution of the mechanical properties of HDPE processed by ECAE up to four passes via route BC, i.e. counter clockwise 90° billet rotation about its longitudinal axis.

It was found that the ECAE process induces significant plastic deformations with changes in the crystalline structure. The ECAE process increased the HDPE crystallinity by 10 to 15%. The number of ECAE passes has a significant effect on the magnitude of the mechanical properties especially on the elastic modulus and yield stress. Young’s modulus and yield strength decreased with increasing the number of ECAE passes and reached a stationary state after the third pass.
Galling and Die Build-Up in Forming Uncoated, Cold-Rolled Advanced High-Strength Steels (AHSS)
Authors: Shih Hua-Chu
Published: September 2015

Uncoated advanced high strength steels (AHSS) are being used for non-exposed automotive applications where high strength is required. Due to higher contact pressures and friction forces between the tooling and sheet steel, increased die wear, die build-up and sheet steel surface galling have been observed. Although various countermeasures have been adopted in production to address these issues, the stamping die tryout process has not been revised accordingly. Proper heat treatment of uncoated tryout dies is required to prevent wear in stamping uncoated, cold-rolled AHSS. Whether die build-up and sheet steel surface galling occur depends on the steel surface condition. The intent of this study is to investigate the effects of steel surface topography on die build-up, sheet steel surface galling and friction in forming uncoated cold-rolled AHSS. DP590 and DP980 with different thickness and different finish rolled textures were tested with the bending under tension (BUT) tester to study these effects. A reciprocal cyclic bend test system (CBTS) of modifying bending under tension test was used to investigate wear and build-up between different surface texture steels in a production condition. Results indicate that the finish roll surface texture is found to be the root cause for the die build-up and steel surface galling that occurs during forming with uncoated dies. The ground-roll surface is the worst in terms of galling and build-up while the Electro-Discharge Textured (EDT) surface is the best. The surface parameters Skewness (Rsk) and Kurtosis (Rku) are found to be able to assess steel galling and die build-up behaviors for uncoated cold rolled AHSS using the uncoated D2 die. A surface with Rsk larger than −0.5 and Rku less than 3 can prevent galling and die build-up in the die tryout process, which is recommended to finish roll the uncoated cold rolled AHSS.
LMDCAM2: Software Tool for Near-Net Repair, Cladding and Built-Up by Laser Metal Deposition
Authors: Flemmer John , Pirch Norbert , Drinck Fabian
Published: September 2015

Laser Metal Deposition (LMD) is growing in importance as a technique for the processing and manufacturing of parts in industry. LMD is used for a wide range of applications including the repair of worn parts, the built-up of 3D structures and the surface functionalization trough cladding. In many cases, the nominal CAD model from the design stage is no longer suitable for the representation of the part geometry due to distortion or defects especially in case of a worn part. This means for the generation of close contoured tool paths it is essential to create a digital model representing the surface of the actual part. This digitalization is often achieved by using a laser scanner whose raw output is represented by point cloud. Tool path planning software (CAM) available on the market generally demonstrate substantial deficits in generating paths on scanned surface data, because these programs are usually optimized on NURBS based surfaces and in most cases were originally designed for subtractive manufacturing applications. LMDCAM2 represents a new software tool especially designed for the LMD process. It is optimized for working with 3D scanned, triangulated data based models which could include noisy data and offers fundamental features for creating and manipulating tool paths adapted to the LMD process. Besides algorithms for calculating close contoured equidistant tracks, the software is also able obtain tracks for additive production through advanced slicing techniques of a 3D model.
The Impact of Argon Shielding Flow Rate on Laser Engineered Net Shaping (LENS) of Ti-6Al-4V
Authors: Heigel J. C. , Michaleris P.
Published: September 2015

The impact of the surface convection generated by argon shielding gas used during Laser Engineered Net Shaping (LENS) on the deposited part is investigated. LENS generates complex thermal histories in the build that are dependent upon the material, part geometry, laser heat input, mass feed rate, and radiative as well as convective cooling. It has been shown that the deposition track and final part quality are subject to many of these considerations; however, no investigation has been undertaken to understand the impact of surface convection resulting from changing the argon shielding gas flow rate. A thermo-mechanical finite element analysis with measurement-based convection models is used to study the effects from different argon shielding flow rates on the temperature history, distortion, and residual stress of thin wall Ti-6Al-4V structures. The results from three cases show that reducing the shielding flow rate by half increases the temperature by 5% to 13%, while decreasing the deflection and residual stress.
Supply Power Design of Oil Cooling Strategies for Precision Ball Screw Unit
Authors: Liu Teng , Gao Weiguo , Zhang Guanwei , Zhang Dawei , Zhang Yifan
Published: September 2015

For the accurate simulation about the heat transfer between the flowing oil coolant and ball screw structure, a heat-fluid-solid interaction transient FE (finite element) modeling method of precision ball screw unit is presented in this paper. This FE modeling method allows a supply power prediction of the oil coolant for precision ball screw unit. Then based on predictions, influencing tendencies from oil cooling strategy (oil supply temperature and volume flow rate) onto the time-varying supply powers of oil coolant are investigated. The research results demonstrate that: Firstly, the supply power of oil coolant has the increasing tendency with the time increase. Besides, the steady scale of oil supply power is in proportion to the oil supply volume flow rate, and in inverse proportion to the oil supply temperature. Finally, the maximum steady supply cooling power brings the guidance for the capacity selection of recirculation cooler for the precision ball screw unit.
Finite Element Study of the Cutting Mechanics of the Three Dimensional Rock Turning Process
Authors: Che Demeng , Smith Jacob , Ehmann Kornel F.
Published: September 2015

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.
A Forager Adjustment Strategy Used by the Bees Algorithm for Solving Optimization Problems in Cloud Manufacturing
Authors: Xie Yongquan , Zhou Zude , Pham Duc Truong , Liu Quan , Xu Wenjun , Ji Chunqian , Lou Ping , Tian Sisi
Published: September 2015

Intelligent technologies have become increasingly important in manufacturing nowadays. Optimal service management and allocation in current cloud manufacturing model are impossible without applications of appropriate intelligent tools. The Bees Algorithm (BA) is a swarm-based intelligent optimizer that provides support for smart decision-making process in manufacturing models. A novel forager adjustment strategy (FAS) is proposed in this paper to manage the forager division in the algorithm, so as to make the entire colony perform with higher efficiency. The proposed FAS based Bees Algorithm (FAS-BA) is able to realize flexible allocation of its forager resources between different roles in accordance with the solution fitness sampled by current scout population. The proposed algorithm is presented in detail. Experiments are conducted based on a set of well-known benchmark functions and a case study. Comparisons between FAS-BA and an improved Bees Algorithm are made to highlight the effectiveness of FAS. The results demonstrate that the proposed algorithm requires less function evaluation cost than the improved version but is capable of obtaining at least the same optimal solution to a problem.
Study of the Gaussian Distribution of Heat Flux for Micro-EDM
Authors: Zhang Fawang , Gu Lin , Zhao Wansheng
Published: September 2015

Gaussian heat flux boundary conditions are widely used to simulate the plasma in the electrothermal models for electrical discharge machining (EDM). However, the plasma thermophysical properties are different under different processing conditions. So it is important to find out the optimal Gaussian distributions of the heat flux for different electrothermal models. This paper suggests a Gaussian distributed heat flux to estimate the plasma heat source based on the law of energy conservation. A parameterized electrothermal model has been developed with the finite element method. By solving the developed model, the temperature field in the workpiece material is calculated. Then the crater radius and depth are estimated based on the calculated molten cavity. Afterwards, the simulated results are compared with the results obtained from single discharge experiments and the optimal Gaussian distribution is determined according to the least mean square error principle. The result shows that the optimal parameter value for micro-EDM is 1.25.