Temporal reasoning about fuzzy intervals

Traditional approaches to temporal reasoning assume that time periods and time spans of events can be accurately represented as intervals. Real-world time periods and events, on the other hand, are often characterized by vague temporal boundaries, requiring appropriate generalizations of existing formalisms. This paper presents a framework for reasoning about qualitative and metric temporal relations between vague time periods. In particular, we show how several interesting problems, like consistency and entailment checking, can be reduced to reasoning tasks in existing temporal reasoning frameworks. We furthermore demonstrate that all reasoning tasks of interest are NP-complete, which reveals that adding vagueness to temporal reasoning does not increase its computational complexity. To support efficient reasoning, a large tractable subfragment is identified, among others, generalizing the well-known ORD Horn subfragment of the Interval Algebra (extended with metric constraints).     

A study on overhead glare in office lighting conditions

Abstract— High‐intensity light sources illuminating the human eye may create discomfort glare, or at higher intensities even disability glare. In many office lighting conditions, light from overhead luminaires in the ceiling may deliver stray light into human eyes, and as such create discomfort glare, generally referred to as overhead glare. In this paper, overhead glare for a LED luminaire comprising a matrix array of small LED sources using subjective evaluation methodologies and theoretical models, commonly accepted to evaluate glare, were investigated. The perceived overhead glare of the LED luminaire is evaluated at various luminance levels and at different angles (i.e., between 55 and 90°) with respect to the line of sight of the viewer. The results show that a luminaire comprising a matrix of high‐intensity point sources can cause overhead glare and can become glary at lower averaged luminance levels than a luminaire with a uniform light source even at high evaluation angles with respect to the line of sight of the viewer. In addition, the conventional UGR model for predicting discomfort glare needs adaptation for a reliable prediction of perceived overhead glare of complex LED luminaires consisting of a matrix of small‐sized high‐intensity light sources.     

Proteomic analysis of BRCA1-depleted cell line reveals a putative role for replication protein A2 up-regulation in BRCA1 breast tumor development

Purpose : Germline mutations in BRCA1 result in a strong predisposition to breast cancer, with frequent loss of heterozygosity of the remaining wild‐type allele. The development of BRCA1 tumors is likely to depend on additional genetic alterations and gene expression changes which follow growth and DNA repair defects associated with BRCA1 deficiency. The identification of these modifications offers an opportunity to find surrogate markers of BRCA1 tumors. Here, we sought to identify differentially expressed proteins related to BRCA1 depletion. Experimental design : We used isogenic HeLa cells either stably knocked‐down or not for BRCA1 (BRCA1^KD) and compared protein profiles of these cells by DIGE. Results : We detected increased levels of Replication protein A2 (RPA2) in BRCA1^KD cells as compared to control cells. RPA2 is an essential protein required for DNA replication and repair. We further demonstrated that depletion of RPA2 subunit delays growth of BRCA1^KD respect to isogenic control cells. Strikingly, elevated levels of RPA2 were more frequently observed in BRCA1 tumors when triple‐negative tumors from BRCA1 mutation carriers (n=13) and non‐carriers (n=36) were stained in situ for RPA2. Conclusions and clinical relevance : RPA2 up‐regulation may thus be involved in the growth and/or survival of BRCA1 tumor cells and useful in immunohistochemical discrimination of triple‐negative BRCA1 tumors.     

Molecular Regulation of Canalicular ABC Transporters

The ATP-binding cassette (ABC) transporters expressed at the canalicular membrane of hepatocytes mediate the secretion of several compounds into the bile canaliculi and therefore play a key role in bile secretion. Among these transporters, ABCB11 secretes bile acids, ABCB4 translocates phosphatidylcholine and ABCG5/G8 is responsible for cholesterol secretion, while ABCB1 and ABCC2 transport a variety of drugs and other compounds. The dysfunction of these transporters leads to severe, rare, evolutionary biliary diseases. The development of new therapies for patients with these diseases requires a deep understanding of the biology of these transporters. In this review, we report the current knowledge regarding the regulation of canalicular ABC transporters’ folding, trafficking, membrane stability and function, and we highlight the role of molecular partners in these regulating mechanisms.     

The interfacial reaction of modified poly (arylether sulfone)s and polyaramides

It is shown that a fracture test using an asymmetric double cantilever beam test geometry is a powerful tool to study the effect of interfacial reactions on the improvement of the interfacial fracture toughness (G_c) of immiscible polymer systems. The G_c values between a partially aromatic polyamide (PA) and a poly(arylether sulfone) (PSU) can be increased significantly when reactive PSUs are used which are obtained by grafting with maleic anhydride by introducing pyromellitic anhydride end-groups or by introducing carboxylic acid groups via copolymerization. Optical and atomic force microscopy investigations of the fracture surfaces show different failure mechanisms for weak and strong interfaces. For weak interfaces it was possible to determine the crack opening geometry using interference microscopy. For significantly reinforced interfaces rib marking lines on the PSU fracture surface can be observed. X-ray photoelectron spectroscopy (XPS) measurements reveal that with increasing toughness of the interface more and more cohesive failure of the PA occurs. This results in an increasing amount of nitrogen detected on the PSU fracture surface and simultaneously no sulfur is detected on the PA fracture surface. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65: 567–579, 1997     

Study of Starch Granules Swelling by the Blue Dextran Method and by Microscopy

The evolution of corn and wheat starch granules swelling at different temperatures was determined by two techniques: the blue dextran method (which measures the swelling factor) and by optical (light) microscopy. The graphical results obtained using the blue dextran technique showed curves indicating the swelling of corn and wheat starch dispersions (at 64%, w/w, moisture content) characterized by an initial phase of slight swelling, a second phase of fast swelling and a final phase of maximum swelling. The concentrated solutions (42% and 47%, w/w, moisture content) showed a slight swelling with the increase in temperature. The effect of temperature on the shape of the granules was evaluated by the optical microscopy. The shape of the type A wheat starch granules was deformed at high temperatures. The corn and type B wheat granules had a spherical form. In the case of corn starch, a good correlation (r²= 0.929) was obtained between the results of optical microscopy and blue dextran techniques.     

Ulva lactuca is poorly fermented but alters bacterial metabolism in rats inoculated with human faecal flora from methane and non-methane producers

In vivo fermentation of Ulva lactuca was studied in previously germ-free rats inoculated with human flora obtained from non-, low- and high-methane producers (groups NMP, LMP and HMP, respectively), in comparison to germ-free rats. Rats were fed either a control diet or a diet containing 4% of dried Ulva lactuca. Production of metabolites varied according to the flora and diet. Ulva lactuca induced a specific high production of methane in the HMP group. With the three human flora, Ulva diet induced a similar increase in caecal pH. In the NMP and HMP groups, this increase was associated with a fall of lactic acid caecal concentration. In the LMP group it was related to a decrease in the concentration of short-chain fatty acids. Ulva lactuca appeared to be able to regulate the β-glucuronidase and β-glucosidase activities, reducing the relatively high levels observed in groups NMP and HMP and increasing the low levels obtained in the LMP group. Results show that, although it was poorly fermented, Ulva induced significant effects on the gut microflora metabolism. The methanogenic status of the human donor appeared to be an important factor. © 1998 SCI.     

Physiological parameters of Bacillus cereus marking the end of acid-induced lag phases

During lag phases microbial cells adapt to their environment and prepare to proliferate. Physiological parameters of B. cereus cells upon exposure to near-growth-boundary acid stress were investigated and markers for the transition between lag phase and growth were identified using fluorescent probes combined with flow cytometry. Determination of cell counts and optical density revealed lag phases of 1 h, 2 h and 5 h, in cultures shifted to pH 7, pH 5.3 (set with lactic acid) and pH 4.9 (set with sulfuric acid), respectively. The obtained lag phases fitted the trends in ATP levels, which were constant during the lag phase and increased after the onset of growth. Both the percentage of PI-stained cells and cells with a significant membrane potential decreased during the lag phase. This points to repair of membrane damage and the loss of membrane potential. However, both trends extended in the growth phase, thus not suitable to mark the onset of growth. The activity of the electron transfer chain and esterases did allow for assessment of transition between lag and growth phase. These activities were generally low during the lag phase and increased after the onset of growth. Our results show that, independent of the duration of the lag phase, for different conditions the same physiological trends could be observed. The change in signal of selected probes can be used as a marker for transition from lag phase to the growth phase and may aid in identification of novel targets interfering with bacterial exit from lag phase.     

Correlations, partitioning and bioaccumulation of heavy metals between different compartments of Lake Balaton

Correlations between trace metals in dissolved and particulate phases, zooplankton, mussels and sediments in Lake Balaton were investigated. The degree of correlation between the various metals was different in each of the investigated compartments. Particulate metal concentrations (microg g(-1)) were anti-correlated with suspended particulate matter (SPM) (mg l(-1)), indicating a dilution effect, while total metal concentrations in the water column (microg l(-1)) were highly correlated with SPM, implying a major influence of the turbidity on the total metal concentrations. Between compartments, not many significant correlations were recognized. Only Ba, Ca, Sr and Mg are correlated in the sediments and in the particulate phase, suggesting common sources for both compartments. Partitioning coefficients (Kd) of trace metals between dissolved and particulate phases are generally low, typical for natural water and fairly stable over the lake. Most of the trace metals (Zn, Co, Cd and Pb) exist in the particulate phase (for about 70% of the total metal load). Cu and Ni are exceptions, showing a more equal distribution. Bioconcentration factors (BCF) of zooplankton and mussels were comparable to those of other natural waters. A negative biomagnification from suspended particulate matter to zooplankton and from sediment to mussel was recognized for all trace metals, except a small enrichment of Zn in zooplankton and Cd in mussel. Four factors were recognized in SPM and in sediments but they did not contain the same group of metals. Cluster analysis showed that metal accumulations in the sediments were different between northern and southern shores and in SPM between western and eastern areas.     

Phthalate removal throughout wastewater treatment plant: Case study of Marne Aval station (France)

The fate of six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) was investigated throughout wastewater treatment processes in the wastewater treatment plant (WWTP) of Marne Aval (France). That plant treats wastewater from a highly populated area and was used as a pilot station for development of nitrification processes.In wastewater, at each step of treatment, DEHP was always the major compound (9 to 44 µg L^− 1), followed by DEP (1.6 to 25 µg L^− 1). Other phthalates averaged 1 µg L^− 1 and DnOP remained close to the detection limit in nearly all cases.In sludge, the prevailing compound was also DEHP (72 µg g^− 1) which is consistent with its tendency to get sorbed upon suspended matter (SM). DnOP came in third, in relation with its resistance to biodegradation.For the studied period, the removal efficiency of DEHP from wastewater was about 78%. That removal seemed to proceed rather from particle settling than from biodegradation. A highly significant correlation (p < 0.001) was found between DEHP and SM concentrations throughout treatment processes. The other compounds: DMP, DEP, DnBP and BBP, displayed satisfactory efficiencies ranging from 68 to over 96% for the lighter ones obviously more easily degraded.Under rainy periods, the plant discharge impact upon Marne River quality in terms of phthalate fluxes, appeared to be minor as compared to the amount brought by the storm overflows in the same area. Downstream of the WWTP discharge, DEHP concentration remained under the European norm for surface water (NQE: 1.3 µg L^− 1).Our study documents the behaviour of phthalate esters throughout a WWTP which treatment device is used by 55% of the WWTP in the river Seine basin.