scholarly journals Dynamics of the Lipid Droplet Proteome of the Oleaginous Yeast Rhodosporidium toruloides

2015 ◽  
Vol 14 (3) ◽  
pp. 252-264 ◽  
Author(s):  
Zhiwei Zhu ◽  
Yunfeng Ding ◽  
Zhiwei Gong ◽  
Li Yang ◽  
Sufang Zhang ◽  
...  

ABSTRACTLipid droplets (LDs) are ubiquitous organelles that serve as a neutral lipid reservoir and a hub for lipid metabolism. Manipulating LD formation, evolution, and mobilization in oleaginous species may lead to the production of fatty acid-derived biofuels and chemicals. However, key factors regulating LD dynamics remain poorly characterized. Here we purified the LDs and identified LD-associated proteins from cells of the lipid-producing yeastRhodosporidium toruloidescultured under nutrient-rich, nitrogen-limited, and phosphorus-limited conditions. The LD proteome consisted of 226 proteins, many of which are involved in lipid metabolism and LD formation and evolution. Further analysis of our previous comparative transcriptome and proteome data sets indicated that the transcription level of 85 genes and protein abundance of 77 proteins changed under nutrient-limited conditions. Such changes were highly relevant to lipid accumulation and partially confirmed by reverse transcription-quantitative PCR. We demonstrated that the major LD structure protein Ldp1 is an LD marker protein being upregulated in lipid-rich cells. When overexpressed inSaccharomyces cerevisiae, Ldp1 localized on the LD surface and facilitated giant LD formation, suggesting that Ldp1 plays an important role in controlling LD dynamics. Our results significantly advance the understanding of the molecular basis of lipid overproduction and storage in oleaginous yeasts and will be valuable for the development of superior lipid producers.

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 326-333 ◽  
Author(s):  
Klaus D. Hamm ◽  
Gunnar Surber ◽  
Michael Schmücking ◽  
Reinhard E. Wurm ◽  
Rene Aschenbach ◽  
...  

Object. Innovative new software solutions may enable image fusion to produce the desired data superposition for precise target definition and follow-up studies in radiosurgery/stereotactic radiotherapy in patients with intracranial lesions. The aim is to integrate the anatomical and functional information completely into the radiation treatment planning and to achieve an exact comparison for follow-up examinations. Special conditions and advantages of BrainLAB's fully automatic image fusion system are evaluated and described for this purpose. Methods. In 458 patients, the radiation treatment planning and some follow-up studies were performed using an automatic image fusion technique involving the use of different imaging modalities. Each fusion was visually checked and corrected as necessary. The computerized tomography (CT) scans for radiation treatment planning (slice thickness 1.25 mm), as well as stereotactic angiography for arteriovenous malformations, were acquired using head fixation with stereotactic arc or, in the case of stereotactic radiotherapy, with a relocatable stereotactic mask. Different magnetic resonance (MR) imaging sequences (T1, T2, and fluid-attenuated inversion-recovery images) and positron emission tomography (PET) scans were obtained without head fixation. Fusion results and the effects on radiation treatment planning and follow-up studies were analyzed. The precision level of the results of the automatic fusion depended primarily on the image quality, especially the slice thickness and the field homogeneity when using MR images, as well as on patient movement during data acquisition. Fully automated image fusion of different MR, CT, and PET studies was performed for each patient. Only in a few cases was it necessary to correct the fusion manually after visual evaluation. These corrections were minor and did not materially affect treatment planning. High-quality fusion of thin slices of a region of interest with a complete head data set could be performed easily. The target volume for radiation treatment planning could be accurately delineated using multimodal information provided by CT, MR, angiography, and PET studies. The fusion of follow-up image data sets yielded results that could be successfully compared and quantitatively evaluated. Conclusions. Depending on the quality of the originally acquired image, automated image fusion can be a very valuable tool, allowing for fast (∼ 1–2 minute) and precise fusion of all relevant data sets. Fused multimodality imaging improves the target volume definition for radiation treatment planning. High-quality follow-up image data sets should be acquired for image fusion to provide exactly comparable slices and volumetric results that will contribute to quality contol.


2019 ◽  
Vol 45 (9) ◽  
pp. 1183-1198
Author(s):  
Gaurav S. Chauhan ◽  
Pradip Banerjee

Purpose Recent papers on target capital structure show that debt ratio seems to vary widely in space and time, implying that the functional specifications of target debt ratios are of little empirical use. Further, target behavior cannot be adjudged correctly using debt ratios, as they could revert due to mechanical reasons. The purpose of this paper is to develop an alternative testing strategy to test the target capital structure. Design/methodology/approach The authors make use of a major “shock” to the debt ratios as an event and think of a subsequent reversion as a movement toward a mean or target debt ratio. By doing this, the authors no longer need to identify target debt ratios as a function of firm-specific variables or any other rigid functional form. Findings Similar to the broad empirical evidence in developed economies, there is no perceptible and systematic mean reversion by Indian firms. However, unlike developed countries, proportionate usage of debt to finance firms’ marginal financing deficits is extensive; equity is used rather sparingly. Research limitations/implications The trade-off theory could be convincingly refuted at least for the emerging market of India. The paper here stimulated further research on finding reasons for specific financing behavior of emerging market firms. Practical implications The results show that the firms’ financing choices are not only depending on their own firm’s specific variables but also on the financial markets in which they operate. Originality/value This study attempts to assess mean reversion in debt ratios in a unique but reassuring manner. The results are confirmed by extensive calibration of the testing strategy using simulated data sets.


2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Susan L. Brockmeier ◽  
Crystal L. Loving ◽  
Tracy L. Nicholson ◽  
Jinhong Wang ◽  
Sarah E. Peters ◽  
...  

ABSTRACT Streptococcus suis is a bacterium that is commonly carried in the respiratory tract and that is also one of the most important invasive pathogens of swine, commonly causing meningitis, arthritis, and septicemia. Due to the existence of many serotypes and a wide range of immune evasion capabilities, efficacious vaccines are not readily available. The selection of S. suis protein candidates for inclusion in a vaccine was accomplished by identifying fitness genes through a functional genomics screen and selecting conserved predicted surface-associated proteins. Five candidate proteins were selected for evaluation in a vaccine trial and administered both intranasally and intramuscularly with one of two different adjuvant formulations. Clinical protection was evaluated by subsequent intranasal challenge with virulent S. suis . While subunit vaccination with the S. suis proteins induced IgG antibodies to each individual protein and a cellular immune response to the pool of proteins and provided substantial protection from challenge with virulent S. suis , the immune response elicited and the degree of protection were dependent on the parenteral adjuvant given. Subunit vaccination induced IgG reactive against different S. suis serotypes, indicating a potential for cross protection.


2014 ◽  
Vol 6 (2) ◽  
pp. 211-233
Author(s):  
Thomas M. Bayer ◽  
John Page

Purpose – This paper aims to analyze the evolution of the marketing of paintings and related visual products from its nascent stages in England around 1700 to the development of the modern art market by 1900, with a brief discussion connecting to the present. Design/methodology/approach – Sources consist of a mixture of primary and secondary sources as well as a series of econometric and statistical analyses of specifically constructed and unique data sets that list nearly more than 50,000 different sales of paintings during this period. One set records sales of paintings at various English auction houses during the eighteenth and nineteenth centuries; the second set consists of all purchases and sales of paintings recorded in the stock books of the late nineteenth-century London art dealer, Arthur Tooth, during the years of 1870/1871. The authors interpret the data under a commoditization model first introduced by Igor Kopytoff in 1986 that posits that markets and their participants evolve toward maximizing the efficiency of their exchange process within the prevailing exchange technology. Findings – We found that artists were largely responsible for a series of innovations in the art market that replaced the prevailing direct relationship between artists and patron with a modern market for which painters produced works on speculation to be sold by enterprising middlemen to an anonymous public. In this process, artists displayed a remarkable creativity and a seemingly instinctive understanding of the principles of competitive marketing that should dispel the erroneous but persistent notion that artistic genius and business savvy are incompatible. Research limitations/implications – A similar marketing analysis could be done of the development of the art markets of other leading countries, such as France, Italy and Holland, as well as the current developments of the art market. Practical implications – The same process of the development of the art market in England is now occurring in Latin America and China. Also, the commoditization process continues in the present, now using the Internet and worldwide art dealers. Originality/value – This is the first article to trace the historical development of the marketing of art in all of its components: artists, dealers, artist organizations, museums, curators, art critics, the media and art historians.


2016 ◽  
Vol 12 (2) ◽  
pp. 126-149 ◽  
Author(s):  
Masoud Mansoury ◽  
Mehdi Shajari

Purpose This paper aims to improve the recommendations performance for cold-start users and controversial items. Collaborative filtering (CF) generates recommendations on the basis of similarity between users. It uses the opinions of similar users to generate the recommendation for an active user. As a similarity model or a neighbor selection function is the key element for effectiveness of CF, many variations of CF are proposed. However, these methods are not very effective, especially for users who provide few ratings (i.e. cold-start users). Design/methodology/approach A new user similarity model is proposed that focuses on improving recommendations performance for cold-start users and controversial items. To show the validity of the authors’ similarity model, they conducted some experiments and showed the effectiveness of this model in calculating similarity values between users even when only few ratings are available. In addition, the authors applied their user similarity model to a recommender system and analyzed its results. Findings Experiments on two real-world data sets are implemented and compared with some other CF techniques. The results show that the authors’ approach outperforms previous CF techniques in coverage metric while preserves accuracy for cold-start users and controversial items. Originality/value In the proposed approach, the conditions in which CF is unable to generate accurate recommendations are addressed. These conditions affect CF performance adversely, especially in the cold-start users’ condition. The authors show that their similarity model overcomes CF weaknesses effectively and improve its performance even in the cold users’ condition.


2015 ◽  
Vol 16 (1) ◽  
pp. 62-85 ◽  
Author(s):  
Cheri Jeanette Duncan ◽  
Genya Morgan O'Gara

Purpose – The purpose of this paper is to examine the development of a flexible collections assessment rubric comprised of a suite of tools for more consistently and effectively evaluating and expressing a holistic value of library collections to a variety of constituents, from administrators to faculty and students, with particular emphasis to the use of data already being collected at libraries to “take the temperature” of how responsive collections are in supporting institutional goals. Design/methodology/approach – Using a literature review, internal and external conversations, several collections pilot projects, and a variety of other investigative mechanisms, this paper explores methods for creating a more flexible, holistic collection development and assessment model using both qualitative and quantitative data. Findings – The products of scholarship that academic libraries include in their collections are expanding exponentially and range from journals and monographs in all formats, to databases, data sets, digital text and images, streaming media, visualizations and animations. Content is also being shared in new ways and on a variety of platforms. Yet the framework for evaluating this new landscape of scholarly output is in its infancy. So, how do libraries develop and assess collections in a consistent, holistic, yet agile, manner? Libraries must employ a variety of mechanisms to ensure this goal, while remaining flexible in adapting to the shifting collections environment. Originality/value – In so much as the authors are aware, this is the first paper to examine an agile, holistic approach to collections using both qualitative and quantitative data.


2014 ◽  
Vol 44 (5) ◽  
pp. 378-388 ◽  
Author(s):  
Ana L. Amaral ◽  
Ederlan S. Ferreira ◽  
Valdir A. Neves ◽  
Aureluce Demonte

Purpose – This paper aims to determine the effects of 11S globulin isolated from Chickpea (Cicer arietinum L.) on lipid metabolism in animals subjected to a hypercholesterolemic and hyperlipidemic diet and compared to the drug simvastatin. Design/methodology/approach – Thirty-six male Wistar rats, kept in individual cages and under appropriate conditions, were separated into groups that were fed a normal diet (STD) containing casein as protein source and according to AIN-93G; a high-cholesterol diet (HC), normal diet plus 1 per cent cholesterol and 0.5 per cent cholic acid and 20 per cent coconut oil; HC diet plus the isolated 11S globulin (300 mg/kg/day); and HC diet plus the simvastatin (50 mg/kg/day), both dissolved in saline and administered by gavage for 28 days. After this time, the animals were killed. Findings – The results indicated that the addition of 1 per cent cholesterol and 0.5 per cent cholic acid induced hypercholesterolemia in the animals without interfering with their weight gain. Analyses of total cholesterol (TC), HDL-cholesterol (HDL-C) and triglycerides (TG) in the plasma, and TC and TG in the liver were made. The results show that the protein isolated from chickpea, and given as a single daily dose, did not affect the levels of plasma TC and its fractions, although decreasing the TG levels. Unlike the simvastatin, the chickpea protein significantly reduced TC and TG in the liver relative to HC group. Originality/value – A single daily dose of 11S globulin from chickpea contributed as only as additional 2.8 per cent of dietary protein intake. These findings demonstrate that 11S chickpea protein acts as a functional agent in the lipid metabolism in addition to its nutritional properties.


2006 ◽  
Vol 27 (6/7) ◽  
pp. 505-514 ◽  
Author(s):  
Jie Huang ◽  
Katherine Wong

PurposeFrom the cataloging librarians' point of view, this paper aims to present how technical services, especially the cataloging department, can play important roles in the improvement of user services.Design/methodology/approachThe paper examines the practices of the University of Oklahoma Libraries.FindingsThe paper identifies several aspects in which technical services can enhance the quality of user services, especially in the cataloging department. A library's online catalog becomes the first point of access to the library's information resources. Its quality can be improved and enriched in many ways to raise users’ satisfaction. Aside from the improvement in technical aspects, efforts should also be made to promote collaboration between technical and public services so as to ensure efficient processing of materials and to meet the needs of library users.Originality/valueThe value of the paper is in showing that the quality of an online catalog and the cooperation between public and technical services are two of the key factors in achieving high quality of user services.


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