Symbolic user-defined periodicity in temporal relational databases

Calendars and periodicity play a fundamental role in many applications. Recently, some commercial databases started to support user-defined periodicity in the queries in order to provide "a human-friendly way of handling time" (see, e.g., TimeSeries in Oracle 8). On the other hand, only few relational data models support user-defined periodicity in the data, mostly using "mathematical" expressions to represent periodicity. In this paper, we propose a high-level "symbolic" language for representing user-defined periodicity which seems to us more human-oriented than mathematical ones, and we use the domain of Gadia's temporal elements in order to define its properties and its extensional semantics. We then propose a temporal relational model which supports user-defined "symbolic" periodicity (e.g., to express "on the second Monday of each month") in the validity time of tuples and also copes with frame times (e.g., "from 1/1/98 to 28/2/98"). We define the temporal counterpart of the standard operators of the relational algebra, and we introduce new temporal operators and functions. We also prove that our temporal algebra is a consistent extension of the classical (atemporal) one. Moreover, we define both a fully symbolic evaluation method for the operators on the periodicities in the validity times of tuples, which is correct but not complete, and semisymbolic one, which is correct and complete, and study their computational complexity.     

MCAM/MUC18/CD146 as a Multifaceted Warning Marker of Melanoma Progression in Liquid Biopsy

Human malignant melanoma shows a high rate of mortality after metastasization, and its incidence is continuously rising worldwide. Several studies have suggested that MCAM/MUC18/CD146 plays an important role in the progression of this malignant disease. MCAM/MUC18/CD146 is a typical single-spanning transmembrane glycoprotein, existing as two membrane isoforms, long and short, and an additional soluble form, sCD146. We previously documented that molecular MCAM/MUC18/CD146 expression is strongly associated with disease progression. Recently, we showed that MCAM/MUC18/CD146 and ABCB5 can serve as melanoma-specific-targets in the selection of highly primitive circulating melanoma cells, and constitute putative proteins associated with disease spreading progression. Here, we analyzed CD146 molecular expression at onset or at disease recurrence in an enlarged melanoma case series. For some patients, we also performed the time courses of molecular monitoring. Moreover, we explored the role of soluble CD146 in different cohorts of melanoma patients at onset or disease progression, rather than in clinical remission, undergoing immune therapy or free from any clinical treatment. We showed that MCAM/MUC18/CD146 can be considered as: (1) a membrane antigen suitable for identification and enrichment in melanoma liquid biopsy; (2) a highly effective molecular “warning” marker for minimal residual disease monitoring; and (3) a soluble protein index of inflammation and putative response to therapeutic treatments.     

Plasma Lipid Profiling Contributes to Untangle the Complexity of Moyamoya Arteriopathy

Moyamoya arteriopathy (MA) is a rare cerebrovascular disorder characterized by ischemic/hemorrhagic strokes. The pathophysiology is unknown. A deregulation of vasculogenic/angiogenic/inflammatory pathways has been hypothesized as a possible pathophysiological mechanism. Since lipids are implicated in modulating neo-vascularization/angiogenesis and inflammation, their deregulation is potentially involved in MA. Our aim is to evaluate angiogenic/vasculogenic/inflammatory proteins and lipid profile in plasma of MA patients and control subjects (healthy donors HD or subjects with atherosclerotic cerebrovascular disease ACVD). Angiogenic and inflammatory protein levels were measured by ELISA and a complete lipidomic analysis was performed on plasma by mass spectrometry. ELISA showed a significant decrease for MMP-9 released in plasma of MA. The untargeted lipidomic analysis showed a cumulative depletion of lipid asset in plasma of MA as compared to HD. Specifically, a decrease in membrane complex glycosphingolipids peripherally circulating in MA plasma with respect to HD was observed, likely suggestive of cerebral cellular recruitment. The quantitative targeted approach demonstrated an increase in free sphingoid bases, likely associated with a deregulated angiogenesis. Our findings indicate that lipid signature could play a central role in MA and that a detailed biomarker profile may contribute to untangle the complex, and still obscure, pathogenesis of MA.     

Multigram-scale production of aliphatic carboxylic acids by oxidation of alcohols with Acetobacter pasteurianus NCIMB 11664

Acetobacter pasteurianus NCIMB 11664 was selected for multigram-scale production of different aliphatic carboxylic acids through oxidation of the corresponding alcohols after screening different acetic acid bacteria. Continuous production was carried out using an air-lift reactor, with overall yields of 1-propionic, 1-butyric, 2-methyl-1-butyric and 3-methyl-1-butyric acids ranging from 45 to 61 g dm⁻³. ©1997 SCI     

Multi-layer higher-order finite elements for the analysis of free-edge stresses in composite laminates

The analysis of the free-edge stress distributions in composite laminates under uniaxial tension is approached by a finite element technique based on a multi-layer higher-order laminate theory. Several finite elements corresponding to different through-thickness assumed distributions of the displacement unknowns are developed. Numerous stacking sequences are examined in the applications. The results are compared with the ones obtained by various investigators with other modelling approaches. The use of the proposed technique is demonstrated to be simple and effective both for the analysis of in-plane and out-of-plane distributions of intralaminar and, noticeably, interlaminar stress components. © 1998 John Wiley & Sons, Ltd.     

An efficient algorithm for ray casting of CSG animation frames

This paper presents a new algorithm to generate ray-cast CSG animation frames. We consider sequences of frames where only the objects can move; in this way, we take advantage of the high screen area coherence of this kind of animation. A new definition of bounding box allows us to reduce the number of pixels to be computed for the frames after the first. We associate a CSG subtree and two new flags, denoting if the box has changed in the current frame and if it will change in the next frame, with each box. We show with three examples the advantages of our technique when compared with an algorithm which entirely renders each frame of an animation. Intersections with CSG objects may be reduced to about one-fifth, while the rendering may be computed up to four times faster for the test sequences. © 1998 John Wiley & Sons, Ltd.     

先进的连续叠层技术赋予非织造材料附加值

对如何高速有效地进行稳定连续不停机的卷绕和使用A.Celli非织造公司制造的可与市场上已有的不同工艺相结合的卷绕设备作了说明,与传统的生产线相比,该生产线的投资少,且灵活性好,特别是可增加产品附加值,因而该工艺过程不再是一个更薄弱的环节,而变成了增加附加值的一个契机。     

Sequence of the GLT1 gene from Saccharomyces cerevisiae reveals the domain structure of yeast glutamate synthase

Glutamate synthase (GOGAT) and glutamine synthetase play a crucial role in ammonium assimilation and glutamate biosynthesis in the yeast Saccharomyces cerevisiae. The GOGAT enzyme has been purified and the GOGAT structural gene (GLT1) has been cloned, showing that this enzyme is a homotrimeric protein with a monomeric size of 199kDa. We report the GLT1 nucleotide sequence and the amino acid sequence of its deduced protein product. Our results show that there is a high conservation with the corresponding genes of Escherichia coli, Medicago sativa (alfalfa) and Zea mais (maize). Binding domains for glutamine, cofactors (FMN and NADH) and the cysteine clusters (which comprise the iron-sulfur centres) were tentatively identified on the basis of sequence comparison with GOGAT sequences from E. coli, alfalfa and maize. The sequence of GLT1 has been deposited in the EMBL data library under Accession Number X89221.     

The Biorefinery Concept: Producing Cellulosic Ethanol from Agricultural Residues

The increasing requirement for more sustainability in the transport sector, which is responsible for more than 25% of CO₂ emissions worldwide and consumes almost 50% of the world's oil production, creates a growing demand for technological advancement in this field. Cellulosic ethanol, produced from agricultural residues, is an advanced biofuel that meets these needs: it offers excellent greenhouse gas savings based on renewable raw materials that are already available in large quantities worldwide. This essay will outline challenges and opportunities for using advanced biofuels, in this particular case, cellulosic ethanol, to reduce the usage and dependency of fossil fuels and cut greenhouse gas emissions in the transport sector, showcasing Clariant's sunliquid® process technology.