66 research outputs found
Mineralogy and petrology of Yamato 000593: Comparison with other Martian nakhlite meteorites
Yamato (Y) 000593 is a new nakhlite recovered from Antarctica and is composed of roughly 80% augite, 10% olivine and 10% mesostasis. Augite is chemically homogeneous except for Fe-rich rims adjacent to the mesostasis. Olivine has more extensive chemical zoning, but the most Fe-rich part is also near the mesostasis. These observations suggest that chemical zoning of both augite and olivine was produced by interaction with the mesostasis. The crystallization history of Y000593 as deduced from this study is as follows. (1) Crystallization of cumulus augite and olivine and formation of symplectites in olivine. (2) Accumulation of augite and olivine. (3) Mesostasis crystallization and interaction of the augite and olivine rims with the intercumulus melt. (4) Aqueous alteration. The petrography and mineralogy of Y000593 is generally similar to other nakhlites, but minor mineralogical differences are observed. These differences resulted from different thermal histories due to different locations (burial depths) in the same cooling cumulate pile. Y000593 is most similar to Nakhla and both samples experienced similar formation histories. However, later mesostasis crystallization of Y000593 was more rapid than Nakhla due to its faster cooling rate. The burial depth of Y000593 would be shallower than 3 m from the surface, and is intermediate between NWA817 and Nakhla. The abundance and mineralogy of the mesostasis as well as augite and olivine rim compositions are related to the burial depths of nakhlites
Yamato 980459: Mineralogy and petrology of a new shergottite-related rock from Antarctica
Y980459, a new Martian meteorite from Antarctica, is composed of coarse porphyritic olivine grains (up to 2mm) set in the groundmass of olivine and pyroxene with abundant glassy mesostasis containing dendritic olivine and pyroxene. The overall petrography of Y980459 is similar to those of olivine-phyric shergottites, but the absence of plagioclase and Ca phosphates makes Y980459 unique. Because of the absence of maskelynite, Y980459 is not a shergottite if we employ the classic definition of shergottite. Both olivine and pyroxenes are extensively zoned. The most magnesian olivine composition is Fo86 and the olivine compositions are related to three different occurrence types of olivine (large phenocrysts, groundmass, and mesostasis). Pyroxenes have orthopyroxene cores (En81Fs17Wo2) mantled by pigeonite with the rims of augite. The mineralogy of Y980459 suggests that rapid crystallization of the parent magma caused significant undercooling and plagioclase did not nucleate. Probably, rapid transport of the Y980459 parent magma from the depth to the Martian surface crystallized olivine and pyroxene at first and eruption onto the surface quenched the magma producing the glassy mesostasis. Because olivine and pyroxene compositions of Y980459 are the most magnesian among Martian meteorites, Y980459 would represent one of the most primitive Martian magmas and derive from a highly reduced mantle. It seems that Y980459 contains no cumulus component, suggesting that Y980459 is a melt. In this sense, Y980459 is similar to QUE94201. The similarity in mineralogy and chemistry between Y980459 and olivine-phyric shergottites suggests derivation from a similar highly reduced mantle. However, Y980459 was the only sample that directly erupted onto the Martian surface without any accumulation processes
Deep Collaborative Filtering Approaches for Context-Aware Venue Recommendation
In recent years, vast amounts of user-generated data have being created on Location-Based Social Networks (LBSNs) such as Yelp and Foursquare. Making effective personalised venue suggestions to users based on their preferences and surrounding context is a challenging task. Context-Aware Venue Recommendation (CAVR) is an emerging topic that has gained a lot of attention from researchers, where context can be the user's current location for example. Matrix Factorisation (MF) is one of the most popular collaborative filtering-based techniques, which can be used to predict a user's rating on venues by exploiting explicit feedback (e.g. users' ratings on venues). However, such explicit feedback may not be available, particularly for inactive users, while implicit feedback is easier to obtain from LBSNs as it does not require the users to explicitly express their satisfaction with the venues. In addition, the MF-based approaches usually suffer from the sparsity problem where users/venues have very few rating, hindering the prediction accuracy. Although previous works on user-venue rating prediction have proposed to alleviate the sparsity problem by leveraging user-generated data such as social information from LBSNs, research that investigates the usefulness of Deep Neural Network algorithms (DNN) in alleviating the sparsity problem for CAVR remains untouched or partially studied
Effect of optical correction on choroidal structure
The aim of this study was to assess the effect of wearing optical correction on the choroidal structure in eyes of children with anisohypermetropic amblyopia. This study was conducted at the Nara Medical University Hospital and at the Tokushima University Hospital. Twenty-nine anisohypermetropic amblyopic eyes and their fellow eyes of 29 amblyopic patients (mean age, 5.7 ± 1.7 years, range 3- to 8-years) and twenty eyes of 20 age-similar control children (4.9 ± 0.8 years, range 4- to 6-years) were studied. All patients wore optical correction and 15 patients had both optical correction and patching. The values at the baseline were compared to that at one year later. The binarization method was used to determine the total, luminal, and stromal areas of the choroid in the enhanced depth imaging optical coherence tomographic images. The best-corrected visual acuity (BCVA) of the amblyopic eyes was significantly improved after the one-year period. A large luminal area was characteristic of the amblyopic eye at the baseline, and it was significantly reduced after the optical treatment. The stromal area widened significantly in the amblyopic and fellow eyes after one year whereas there were no significant changes in the choroid of the control eyes after one year. After one-year of optical correction, the luminal/stromal ratios in the amblyopic and fellow eyes were decreased and were then not significantly different from that of the normal control eyes. There was a significant and positive correlation between the improvement of the BCVA and the stromal area at the baseline (r = 0.64, P = 0.001). Wearing corrective lenses on the amblyopic eyes improves the BCVA, and the choroidal structure of the amblyopic eye becomes closer to that of the control eyes. The narrowed luminal area is a specific response of the amblyopic eye associated with the correction of the refractive error. The larger stromal area in the amblyopic eyes at the baseline is a predictive factor for improvements of the BCVA
Detailed analyses of the crucial functions of Zn transporter proteins in alkaline phosphatase activation
Numerous zinc ectoenzymes are metalated by zinc and activated in the compartments of the early secretory pathway before reaching their destination. Zn transporter (ZNT) proteins located in these compartments are essential for ectoenzyme activation. We have previously reported that ZNT proteins, specifically ZNT5-ZNT6 heterodimers and ZNT7 homodimers, play critical roles in the activation of zinc ectoenzymes, such as alkaline phosphatases (ALPs), by mobilizing cytosolic zinc into these compartments. However, this process remains incompletely understood. Here, using genetically-engineered chicken DT40 cells, we first determined that Zrt/Irt-like protein (ZIP) transporters that are localized to the compartments of the early secretory pathway play only a minor role in the ALP activation process. These transporters included ZIP7, ZIP9, and ZIP13, performing pivotal functions in maintaining cellular homeostasis by effluxing zinc out of the compartments. Next, using purified ALP proteins, we showed that zinc metalation on ALP produced in DT40 cells lacking ZNT5-ZNT6 heterodimers and ZNT7 homodimers is impaired. Finally, by genetically disrupting both ZNT5 and ZNT7 in human HAP1 cells, we directly demonstrated that the tissue-nonspecific ALP-activating functions of both ZNT complexes are conserved in human cells. Furthermore, using mutant HAP1 cells, we uncovered a previously-unrecognized and unique spatial regulation of ZNT5-ZNT6 heterodimer formation, wherein ZNT5 recruits ZNT6 to the Golgi apparatus to form the heterodimeric complex. These findings fill in major gaps in our understanding of the molecular mechanisms underlying zinc ectoenzyme activation in the compartments of the early secretory pathway
Choroidal Structure in Children with Anisohypermetropic Amblyopia
Purpose
To compare the choroidal structure of the subfoveal area in the eyes of children with anisohypermetropic amblyopia to that of the fellow eyes and to age-matched controls using a binarization method of the images obtained by enhanced depth imaging optical coherence tomography (EDI-OCT).
Methods
This study was performed at Nara Medical University Hospital, Tokushima University Hospital, and Kagoshima University Hospital, Japan. Forty amblyopic eyes with anisohypermetropic amblyopia and their fellow eyes (5.9 ± 2.1 years, mean ± standard deviation), and 103 age-matched controls (6.7 ± 2.4 years) were studied. The control eyes were divided into myopic, emmetropic, and hyperopic eyes. The total choroidal area, luminal area and stromal area of the subfoveal choroid were measured by the binarization method. The luminal/ stromal ratio and the axial length of the amblyopic eyes were compared to that of the control eyes.
Results
The total choroidal area in the amblyopic eyes was significantly larger than that of the fellow eyes (P = 0.005). The luminal/stromal ratio was significantly larger in the amblyopic eyes than that of the fellow eyes (P<0.001) and the control hyperopic eyes (P<0.001). There was a significant negative correlation between the luminal/stromal ratio and the axial length in the control eyes (r = -0.30, P = 0.001), but no significant correlation was found in the amblyopic eyes.
Conclusions
The choroidal structure of the amblyopic eyes was different from that of the fellow and the control hyperopic eyes. The choroidal changes are related to amblyopia
Systematic NMR Analysis of Stable Isotope Labeled Metabolite Mixtures in Plant and Animal Systems: Coarse Grained Views of Metabolic Pathways
BACKGROUND: Metabolic phenotyping has become an important 'bird's-eye-view' technology which can be applied to higher organisms, such as model plant and animal systems in the post-genomics and proteomics era. Although genotyping technology has expanded greatly over the past decade, metabolic phenotyping has languished due to the difficulty of 'top-down' chemical analyses. Here, we describe a systematic NMR methodology for stable isotope-labeling and analysis of metabolite mixtures in plant and animal systems. METHODOLOGY/PRINCIPAL FINDINGS: The analysis method includes a stable isotope labeling technique for use in living organisms; a systematic method for simultaneously identifying a large number of metabolites by using a newly developed HSQC-based metabolite chemical shift database combined with heteronuclear multidimensional NMR spectroscopy; Principal Components Analysis; and a visualization method using a coarse-grained overview of the metabolic system. The database contains more than 1000 (1)H and (13)C chemical shifts corresponding to 142 metabolites measured under identical physicochemical conditions. Using the stable isotope labeling technique in Arabidopsis T87 cultured cells and Bombyx mori, we systematically detected >450 HSQC peaks in each (13)C-HSQC spectrum derived from model plant, Arabidopsis T87 cultured cells and the invertebrate animal model Bombyx mori. Furthermore, for the first time, efficient (13)C labeling has allowed reliable signal assignment using analytical separation techniques such as 3D HCCH-COSY spectra in higher organism extracts. CONCLUSIONS/SIGNIFICANCE: Overall physiological changes could be detected and categorized in relation to a critical developmental phase change in B. mori by coarse-grained representations in which the organization of metabolic pathways related to a specific developmental phase was visualized on the basis of constituent changes of 56 identified metabolites. Based on the observed intensities of (13)C atoms of given metabolites on development-dependent changes in the 56 identified (13)C-HSQC signals, we have determined the changes in metabolic networks that are associated with energy and nitrogen metabolism
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
ニュータウンに居住する専業主婦の外出頻度および主観的健康感との関係
専業主婦については、活動量や運動量の制限などが報告されている一方、若年期からの地域とのつながりにより外出頻度は維持されやすいと考えられる. そこで高齢者で報告されている外出頻度と主観的健康感との関連が専業主婦でもみられるのか、年齢による影響を明らかにすることを目的とした. 研究は大阪府堺市南区の一地区内の全世帯(3,069世帯)に無記名自記式の質問紙調査を行い、回答数1,820(回収率58.0%)の中から専業主婦701名を分析対象とした. 質問項目は最近1週間の外出頻度、主観的健康感について尋ねた. その結果、外出頻度は60代、70代後半、80代以上と段階的に減少した. 主観的健康感は加齢とともに不安あり群が増加した. 外出頻度と主観的健康感の関連は50代以上で外出頻度が減少するとともに主観的健康感が低下する傾向を認めた. 以上より、健康維持、増進のためには50代から年代ごとの取り組みが必要であることが示唆された.Physical activity levels and the amount of exercise in housewives are reportedly low; however, a high frequency of outings is likely to be maintained due to connection with local residents. This study aimed to identify the relationship between the frequency of outings and self-rated health in housewives, and investigate age-related effects. Anonymous self-administered questionnaires were distributed to 3,069 households in one district of Minami-ku, Sakai-shi, Osaka, and, of the 1,820 responses (response rate: 58.0%), 701 housewives were analyzed. Questionnaire items included the frequency of outings and self-rated health over the past one week. As the results of the questionnaire, the frequency of outings gradually decreased as the age advanced from their 60s to 80s or over. Regarding self-rated health, the number of subjects with anxiety increased with age. Among the subjects aged 50 or over, there was a decreasing trend in the frequency of outings and self-rated health. The findings suggest the need to take appropriate measures to maintain and promote the health of housewives aged 50 and over according to their age group
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