Biosynthesis and Assembly of Very Long Chain Polyunsaturated Fatty Acids in Thraustochytrium sp. 26185

Thraustochytrium is a marine protist producing a specific profile of nutritionally important fatty acids, including very long chain polyunsaturated fatty acids (VLCPUFAs) docosahexaenoic acid (DHA, 22:6n-3), even-chain saturated fatty acids (SFAs) palmitic acid (16:0), and odd-chain SFAs pentadecanoic acid (15:0). However, the mechanism of how these fatty acids are synthesized and assembled into the storage lipid triacylglycerol (TAG) is unclear. Firstly, we reported sequencing of the whole genome and genomic analysis of genes involved in the biosynthesis and assembly of the fatty acids in this species. Analysis of annotated genes from the genome revealed co-existence of both aerobic pathway and anaerobic pathways for the biosynthesis of VLCPUFAs in this species. However, in the aerobic pathway, a key gene encoding stearoyl 9 desaturase introducing the first double bond to long chain saturated fatty acid 18:0 was missing from the genome. A genomic survey of genes involved in the acyl trafficking among glycerolipids showed that, unlike plants, this protist did not possess phosphatidylcholine: diacylglycerol cholinephosphotransferase (PDCT), an important enzyme in bridging two types of glycerolipids, diacylglycerol (DAG) and phosphatidylcholine (PC). Secondly, a series of radiolabeled precursors were used to trace the biosynthetic process of different fatty acids in vivo and in vitro. When Thraustochytrium was fed with long chain fatty acid intermediates such as 14C-oleic acid, 14C-linoleic acid and 14C-α-linolenic acid, no VLCPUFAs were produced, indicating that the aerobic pathway for the biosynthesis of VLCPUFAs was not functional in Thraustochytrium. When fed with 14C-acetic acid, both SFAs and VLCPUFAs were labeled, and when fed with 14C-propionic acid, mainly SFAs were labeled. However, when fed with 14C-acetic acid in the presence of cerulenin, a type I FAS inhibitor, only VLCPUFAs were labeled, and when fed with 14C-propionic acid in the presence of cerulenin, neither SFAs nor VLCPUFAs were labeled. This result clearly indicates that the type I fatty acid synthase (FAS) in Thraustochytrium could use acetic acid and propionic acid as the primers to synthesize even-chain and odd-chain SFAs, respectively, and VLCPUFAs were synthesized by the PUFA synthase using acetic acid as the primer. The in vitro assay with 14C-malonyl-CoA in the presence of cerulenin showed that the crude protein of Thraustochytrium produced only VLCPUFAs, not SFAs, further confirming the role of the PUFA synthase in the biosynthesis of VLCPUFAs. These results have elucidated the biochemical mechanisms for the biosynthesis of all fatty acids in Thraustochytrium. Thirdly, how freshly-synthesized fatty acids are incorporated into different glycerolipids was investigated. The glycerolipid profile of Thraustochytrium at log and stationary growth stages was analyzed by lipidomic tools, and then 14C-acetate and 14C-glycerol were used to trace the flux of fatty acids and backbone in glycerolipids. Lipidomic analysis showed that VLCPUFAs were mostly allocated to phosphatidylcholine (PC) and TAG. PC possessed a relatively stable profile of VLCPUFAs at the two growth stages, whereas TAG species with one or two VLCPUFAs were significantly increased at the stationary phase. Freshly-synthesized VLCPUFAs labeled by 14C-acetate were predominately incorporated into PC initially, while at the late time point of labeling, these fatty acids were mostly found in TAG. Positional analysis showed that PC had either one VLCPUFA at its sn-2 position (PC1) or two VLCPUFAs at both sn-1 and sn-2 positions (PC2), while TAG incorporated these fatty acids almost exclusively at the sn-2 position with similar stereospecific structure as PC1. Similarly, 14C-glycerol was more efficiently incorporated into PC1 than TAG initially, and at the late time point of labeling, it was mostly found in TAG, and DAG and PC1 shared a similar incorporation pattern. These results indicate that VLCPUFAs in TAG are mainly channeled from PC likely through diacylglycerol as the intermediate

ROTATION PERIODS OF 1660 WOOD, 7173 SEPKOSKI, 12738 SATOSHIMIKI, AND (23233) 2000 WM72

We present rotation periods of four asteroids: 1660 Wood, 7173 Sepkoski, 12738 Satoshimiki, and (23233) 2000 WM72. The observations were undertaken using the SARA (Southeastern Association for Research in Astronomy) South telescope, located in Cerro Tololo Inter-American Observatory in Chile, from 2011 December to 2012 April. The following synodic periods were found: 1660 Wood, P = 6.8088 ± 0.0002 h; 7173 Sepkoski, P = 2.44 ± 0.02 h; 12738 Satoshimiki, P = 8.708 ± 0.001 h; and (23233) 2000 WM72, P = 3.732 ± 0.003 h

NormalNet: Learning based Guided Normal Filtering for Mesh Denoising

Mesh denoising is a critical technology in geometry processing, which aims to recover high-fidelity 3D mesh models of objects from noise-corrupted versions. In this work, we propose a deep learning based face normal filtering scheme for mesh denoising, called \textit{NormalNet}. Different from natural images, for mesh, it is difficult to collect enough examples to build a robust end-to-end training scheme for deep networks. To remedy this problem, we propose an iterative framework to generate enough face-normal pairs, based on which a convolutional neural networks (CNNs) based scheme is designed for guidance normal learning. Moreover, to facilitate the 3D convolution operation in CNNs, for each face in mesh, we propose a voxelization strategy to transform irregular local mesh structure into regular 4D-array form. Finally, guided normal filtering is performed to obtain filtered face normals, according to which denoised positions of vertices are derived. Compared to the state-of-the-art works, the proposed scheme can generate accurate guidance normals and remove noise effectively while preserving original features and avoiding pseudo-features

FOUR COLOR OBSERVATIONS OF 2501 LOHJA

Photometric studies of asteroid 2501 Lohja were made between 2014 June 24 and 25 using the Southeastern Association for Research in Astronomy (SARA) Kitt Peak telescope with Bessell B, V, R and I filters. We obtained a synodic period of 3.81 ± 0.01h, which is consistent with previous values

Analysis of XBRL literature : a decade of progress and puzzle

XBRL (eXtensible Business Reporting language) was recently, in 2008, in its 10th year. The concept was articulated in 1998 by Charles Hoffman, known as XFRML (eXtensible Financial Reporting Mark Up Language) to facilitate the business reporting process and improve financial reporting. The objective of this paper is to examine a decade (1998-2008) of XBRL articles published in various publications including trade, practitioner and academic journals to identify trends and patterns, milestones, and organizations actively contributed to this development. Another goal is to assess public perceptions of XBRL, its capabilities and its future. We examined published articles where XBRL appeared either in the title or abstract of the article during 1998-2008. Considering that XBRL reporting is being required only in recent years, the research shows various interest groups worked together for a long time to achieve a common goal. The academic community has also been proactive in contributing to and assessing this new reporting standard. There is a trail of research articles to document this contribution. This paper provides various charts and interesting statistics

Economic Burden for Lung Cancer Survivors in Urban China.

BackgroundWith the rapid increase in the incidence and mortality of lung cancer, a growing number of lung cancer patients and their families are faced with a tremendous economic burden because of the high cost of treatment in China. This study was conducted to estimate the economic burden and patient responsibility of lung cancer patients and the impact of this burden on family income.MethodsThis study uses data from a retrospective questionnaire survey conducted in 10 communities in urban China and includes 195 surviving lung cancer patients diagnosed over the previous five years. The calculation of direct economic burden included both direct medical and direct nonmedical costs. Indirect costs were calculated using the human capital approach, which measures the productivity lost for both patients and family caregivers. The price index was applied for the cost calculation.ResultsThe average economic burden from lung cancer was $43,336 per patient, of which the direct cost per capita was$42,540 (98.16%) and the indirect cost per capita was $795 (1.84$30,277 per capita, which accounted for 171% of the household annual income, a percentage that fell to 107% after subtracting the compensation from medical insurance.ConclusionsThe economic burden for lung cancer patients is substantial in the urban areas of China, and an effective control strategy to lower the cost is urgently needed

Very Long Chain Polyunsaturated Fatty Acids Accumulated in Triacylglycerol Are Channeled From Phosphatidylcholine in Thraustochytrium

Thraustochytrium is a marine protist that can accumulate a large amount of very long chain polyunsaturated fatty acids (VLCPUFA) in triacylglycerols (TAG). How these freshly synthesized VLCPUFAs are channeled into TAG remains unknown. In this study, the glycerolipid profile of Thraustochytrium at log and stationary growth stages was first analyzed by lipidomic tools, and then 14C-acetate and 14C-glycerol were used to trace the flux of fatty acids and backbone in glycerolipids. Lipidomic analysis showed that VLCPUFAs were mostly allocated to phosphatidylcholine (PC) and TAG. PC possessed a relatively stable profile of VLCPUFAs, whereas TAG carrying VLCPUFAs were significantly increased at the stationary phase. 14C-acetate labeled VLCPUFAs were predominately incorporated into PC initially but were mostly found in TAG at later time of labeling. Positional analysis showed that PC had either one VLCPUFA at its sn-2 position (PC1) or two VLCPUFAs (PC2), while TAG incorporated VLCPUFAs almost exclusively at the sn-2 position. Similarly, 14C-glycerol was more efficiently incorporated into PC1 than TAG initially but was mostly found in TAG at later time of labeling, and diacylglycerol and PC1 shared a similar incorporation pattern. These results indicate that VLCPUFAs in TAG are mainly channeled from PC likely through diacylglycerol as the intermediate