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• Novel discovery approaches are based on proteolytic activation. • Antibody therapies targeting proteolytic activation. • Activatable pro-forms of antibodies or effector proteins. Proteases have crucial roles in homeostasis and disease; and protease inhibitors and recombinant proteases in enzyme replacement therapy have become key therapeutic applications of protease biology across several indications. This review briefly summarises therapeutic approaches based on protease activation and focuses on how recent insights into the spatial and temporal control of the proteolytic activation of growth factors and interleukins are leading to unique strategies for the discovery of new medicines. In particular, two emerging areas are covered: the first is based on antibody therapies that target the process of proteolytic activation of the pro-form of proteins rather than their mature form; the second covers a potentially new class of biopharmaceuticals using engineered, proteolytically activable and initially inactive pro-forms of antibodies or effector proteins to increase specificity and improve the therapeutic window. [ABSTRACT FROM AUTHOR]

A versatile and simple mass balance method for the measurement of the release fraction of thoracic and respirable particles of non-volatile compounds of spray products is presented. The release fractions are defined as the ratio between the mass of suspended non-volatile particulate matter in the thoracic and respirable particle size range and the total mass of non-volatile material released with the spray action. For its determination, a spray bolus of short duration and of defined mass is sprayed into a well stirred control chamber. The respirable and thoracic aerosol mass associated with the spray bolus is determined by measuring the time averaged mass concentration inside the control volume and the half time of the exponential concentration decrease to be expected in well stirred systems to correct for mass losses during sampling.  The method is used for a wide range of spray products and technologies for which the release fractions vary by orders of magnitude. A set of data is presented elucidating the relationship between spray technology and fine particle release. Furthermore, a simple rule of thumb was derived from the data that allows for estimation of the release fractions based on a characteristic diameter of the spray droplets. The usefulness of the mass balance method for substance classification as well as for generating input data for exposure assessment and indoor air quality modeling is discussed. [ABSTRACT FROM PUBLISHER]

Objectives Foaming and spraying are common application techniques for biocidal products. In the past, inhalation and dermal exposure during spraying have been investigated extensively. Currently, however, no exposure data are available for foaming, hindering a reliable risk assessment for foam applications of biocidal products. The focus of this project was the quantification of inhalation and potential dermal exposure to non-volatile active substances during the foam application of biocidal products in occupational settings. In some settings, exposure during spray application was measured for comparative purposes. Methods The inhalation and dermal exposure of operators were investigated during the application of benzalkonium chlorides and pyrethroids by foaming and spraying, considering both small- and large-scale application devices. Inhalation exposure was measured by personal air sampling; potential dermal exposure was measured using coveralls and gloves. Results Potential dermal exposure was substantially higher than inhalation exposure. Changing from spraying to foaming reduced inhalation exposure to airborne non-volatile active substances, but had no relevant effect on potential dermal exposure. However, for potential dermal exposure, considerable differences were observed between the application device categories. Conclusions To our knowledge, this study presents the first comparative exposure data for the foam and spray application of biocidal products in occupational settings with detailed contextual information. The results indicate a reduction of inhalation exposure with foam application compared to spray application. However, special attention is necessary for dermal exposure, which is not reduced by this intervention. [ABSTRACT FROM AUTHOR]

The increasing trend toward multisensor systems is driving an interest for distributed tracking algorithms. In such systems, data transmissions with imperfect communication links often lead to varying time delays. The challenge of online processing of delayed data is generally known as the out-of-sequence (OoS) problem. An exact solution to this problem is given by the accumulated state density (ASD) filter. However, the Rauch-Tung-Striebel (RTS) retrodiction1 is inherently integrated to the ASD approach, so a certain number of states must be updated at each filtering step. In this paper, a generalized form of the ASD filter is presented. In particular, the exact update formula for states that refer to time instants that are older and newer than a given measurement is calculated. As a consequence, OoS data can be processed without applying retrodiction. A novel smoothing scheme is presented that uses the exact cross-covariances of a measurement and a past state without recursion. A numerical evaluation shows that this smoothing scheme is about 25% faster than the RTS equations yet is still exact. [ABSTRACT FROM AUTHOR]

One of the main challenges in the domain of ground target tracking based on measurements from airborne ground moving target indication (GMTI) radar is the masking of targets due to the Doppler blind zone of the sensor. This blind zone arises from the clutter cancellation by space-time adaptive processing (STAP) to separate moving target returns from the general clutter background. Low-Doppler targets can easily be masked by such a blind zone, leading to sequences of missed detections that strongly deteriorate the performance of a standard tracking filter. This work investigates the Doppler blind zone in the case of bistatic transmitter and receiver configurations and its impact on the tracking of ground targets. The knowledge on the Doppler blind zone is incorporated into a Bayesian unscented Kalman filter multiple hypothesis tracker (UKF-MHT) tracking filter that is also capable of using road-map information. Based on different simulation scenarios, it is demonstrated that in contrast to a monostatic configuration with sideways-looking radar, the blind zone width determined by the minimum detectable velocity is not constant in general. The obtained track results reveal the benefit of exploiting this additional knowledge, especially in combination complementary with road-map information if available. [ABSTRACT FROM PUBLISHER]

Abstract: Five commercially available insect sprays were applied in a model room. Spraying was performed in accordance with the manufacturers’ instructions and in an overdosed manner in order to simulate worst-case conditions or an unforeseeable misuse. In addition, we examined electro-vaporizers. The Respicon™ aerosol monitoring system was applied to determine inhalation exposure. During normal spraying (10 seconds) and during the following 2–3 minutes, exposure concentrations ranged from 70 to 590μg/m3 for the pyrethroids tetramethrin, d-phenothrin, cyfluthrin, bioallethrin, and the pyrethrins. Calculated inhalable doses were 2–16μg. A concentration of approximately 850μg chlorpyrifos/m3 (inhalable dose: approximately 20μg) was determined when the “Contra insect fly spray” was applied. Highest exposure concentrations (1100–2100μg/m3) were measured for piperonyl butoxide (PBO), corresponding to an inhalation intake of 30–60μg. When simulating worst-case conditions, exposure concentrations of 200–3400μg/m3 and inhalable doses of 10–210μg were determined for the various active substances. Highest concentrations (4800–8000μg/m3) were measured for PBO (inhalable: 290–480μg). By applying the electro-vaporizer “Nexa Lotte” plug-in mosquito killer concentrations for d-allethrin were in the range of 5–12μg/m3 and 0.5–2μg/m3 for PBO while with the “Paral” plug-in mosquito killer concentrations of 0.4–5μg/m3 for pyrethrins and 1–7μg/m3 for PBO were measured. Potential dermal exposures were determined using exposure pads. Between 80 and 1000μg active substance (tetramethrin, phenothrin, cyfluthrin, bioallethrin, pyrethrins, chlorpyrifos) were deposited on the clothing of the total body surface area of the spray user. Highest levels (up to 3000μg) were determined for PBO. Worst-case uses of the sprays led to 5–9 times higher concentrations. Also a 2-hour stay nearby an operating electro-vaporizer led to a contamination of the clothing (total amounts on the whole body were 450μg d-allethrin and 50μg PBO for “Nexa Lotte” plug-in mosquito killer and 80μg pyrethrins and 190μg PBO for “Paral” plug-in mosquito killer). Human biomonitoring data revealed urine concentrations of the metabolite (E)-trans-chrysanthemum dicarboxylic acid ((E)-trans-CDCA) between 1.7μg/l and 7.1μg/l after 5 minutes of exposure to the different sprays. Also the use of electro-vaporizers led to (E)-trans-CDCA concentrations in the urine in the range of 1.0μg/l to 6.2μg/l (1–3 hours exposure period). The exposure data presented can be used for performing human risk assessment when these biocidal products were applied indoors. The airborne concentrations of the non-volatile active chemical compounds could be predicted from first principles using a deterministic exposure model (SprayExpo). [Copyright &y& Elsevier]

Abstract: Collectively moving object clusters are of particular interest in certain applications and have to be tracked as separate aggregated entities consisting of an unknown number of individuals. Group targets often will not cause as many detections since there are individual targets in the group due to limited sensor resolution capabilities. In this case, tracking and data association under the ‘one target, one detection’ assumption are no longer applicable. In this paper, ellipsoidal object extensions are modeled by random matrices, which are treated as additional state variables to be estimated. An important aspect of GMTI tracking is the incorporation of context information into the Bayesian data processing formalism. Here we consider kinematical constraints such as road maps and sensor specific characteristics such as Doppler blindness. [Copyright &y& Elsevier]

Target tracking with adaptive phased-array radars in the presence of standoff jamming presents both challenges and opportunities to the track filter designer. A measurement likelihood function is derived for this situation which accounts for the effect of both positive and negative contact information. This likelihood function is approximated as a weighted sum of Gaussian terms consisting of both positive and negative weights, accounting for the positive and negative contact information. Additionally, recent theoretical results have been reported which have derived an accurate measurement error covariance in the vicinity of the jammer when adaptive beamforming is used by the radar to null the effects of the jammer. We compare the impact of using a likelihood function that accounts for negative contact information and the corrected measurement error covariance by comparing five Kalman filter-based trackers in five different scenarios. We show that only those track filters which use both the negative contact information and the corrected measurement error covariance are effective in maintaining track on a maneuvering target as it passes through the jamming region. This approach can also be generalized to any target tracking problem where the sensor response is anisotropic. [ABSTRACT FROM AUTHOR]

Abstract: In various applications of target tracking and sensor data fusion all available information related to the sensor systems used and the underlying scenario should be exploited for improving the tracking/fusion results. Besides the individual sensor measurements themselves, this in particular includes the use of more refined models for describing the sensor performance. By incorporating this type of background information into the processing chain, it is possible to exploit ‘negative’ sensor evidence. The notion of ‘negative’ sensor evidence covers the conclusions to be drawn from expected but actually missing sensor measurements for improving the position or velocity estimates of targets under track. Even a failed attempt to detect a target is a useful sensor output, which can be exploited by appropriate sensor models providing background information. The basic idea is illustrated by selected examples taken from more advanced tracking and sensor data fusion applications such as group target tracking, tracking with agile beam radar, ground moving target tracking, or tracking under jamming conditions. [Copyright &y& Elsevier]

Abstract: Using accurate inputs of wind speed is crucial in wind resource assessment, as predicted power is proportional to the wind speed cubed. First, wind speeds retrieved from a series of 91 ERS-2 SAR and Envisat ASAR images, at moderate wind speeds (2–15 m s−1), were validated against in situ measurements from an offshore mast in the North Sea. The wind direction input, necessary for SAR wind speed retrievals, was obtained from the meteorological mast and from a local gradient analysis of wind streaks in the SAR images. A wind speed standard deviation of ∼1.1 m s−1 was found when in situ wind directions were used. The use of local gradient wind directions yielded a standard deviation of ∼1.3 m s−1. Wind speeds retrieved from three geophysical model functions (CMOD-IFR2, CMOD4, and CMOD5) were compared. The best approximation to the in situ measurements of wind speed was found for CMOD-IFR2, despite a bias on the order of −0.3 m s−1. CMOD4 retrievals also underestimated the wind speed, whereas the bias on CMOD5 retrievals was negligible. Then, wind resource assessments were made from the SAR-based wind observations to show how errors in wind speed from the different SAR wind retrievals were reflected in the wind statistics. The mean wind speed, obtained for all of the 91 SAR scenes, was linked closely to the bias of SAR wind retrievals. Agreement to ±15% of the in situ measurements was found for all the wind retrieval methods tested. The accuracy of power density estimates for the entire data set was evaluated by the standard deviation of SAR wind retrievals relative to the in situ measurements. SAR wind fields retrieved with CMOD-IFR2, using in situ wind direction inputs, exactly yielded the power density predicted from in situ measurements alone. The SAR-based wind resource assessment also corresponded well to predictions from longer time series of in situ measurements. This indicates that a reliable wind resource assessment may be achieved from a series of randomly selected SAR images. The findings presented here could be useful in future wind resource assessment based on SAR images. [Copyright &y& Elsevier]

Tracking ground targets with airborne GMTI (ground moving target indicator) sensor measurements proves to be a challenging task due to high target density, high clutter, and low visibility. The exploitation of nonstandard background information such as road maps and terrain information is therefore highly desirable for the enhancement of track quality and track continuity. The present paper presents a Bayesian approach to incorporate such information consistently. It is particularly suited to deal with winding roads and networks of roads. The target dynamics is modeled in quasi one-dimensional road coordinates and mapped onto ground coordinates using linear road segments taking road map errors into account. The case of several intersecting roads with different characteristics, such as mean curvature, slope, or visibility, is treated within an interacting multiple model (IMM) scheme. Targets can be masked both by the clutter notch of the sensor and by terrain obstacles. Both effects are modeled using a sensor-target state dependent detection probability. The iterative filter equations are formulated within a framework of Gaussian sum approximations on the one hand and a particle filter approach on the other hand. Simulation results for single targets taken from a realistic ground scenario show strongly reduced target location errors compared with the case of neglecting road-map information. By modeling the clutter notch of the GMTI sensor, early detection of stopping targets is demonstrated. [ABSTRACT FROM AUTHOR]

Wind vectors over the ocean were extracted from a large number of synthetic aperture radar (SAR) images from the European Remote Sensing Satellites (ERS-1 and ERS-2). The wind directions are inferred from the orientation of wind streaks that are imaged by the SAR, while the wind speeds are retrieved by inversion of the C-band model CMOD4. The derived wind directions and speeds were compared to wind vectors from the numerical Regional Model (REMO) that are available hourly on a 55-km grid. The large number of comparisons and independent weather situations allowed for an analysis of subsets that are classified by SAR-derived wind speed. A strong decrease of the standard deviation of directional differences with increasing wind speed was found. Biases of directional differences depend on SAR wind speed as well. Furthermore, the influence of the temporal difference between SAR overflight and model and an automatic image filtering on the directional error is demonstrated. Overall, reasonable fields of wind vectors were extracted from SAR imagery in 70 of 80 cases. These fields provide valuable information for validation of numerical models of the atmosphere and case studies of coastal wind fields. [ABSTRACT FROM AUTHOR]

Abstract: A new “pre-embarkation” method for aircraft disinsection was investigated using two different 2% d-phenothrin containing aerosols. Five experiments in aircrafts of the type Airbus 310 (4×) and Boeing 747–400 (1×) were performed. In the absence of passengers and crew the d-phenothrin aerosol was sprayed under the seat rows and in a second step at the height of approximately 1.60m by moving from one end of the cabin to the other. Concentration levels of d-phenothrin were determined at different time periods after application of the aerosol spray. In a B 747–400 with the air conditioning system operating the concentrations ranged between 853 and 1753μg/m3 during and till 5min after the beginning of spraying at different locations in the cabin. Within 5–20min after the end of the spraying concentrations of 36–205μg/m3 and 20–40min thereafter only ca. 1μg d-phenothrin/m3 were detectable (average values in relation to each period of measurement). On cabin interior surfaces the median values for mainly horizontal areas ranged from 100 to 1160ng d-phenothrin/cm2. d-Phenothrin concentrations in the air were sufficient to kill flying insects like house flies and mosquitoes within 20min. Horizontal surfaces were 100% effective against insects up to 24h after spraying. Doses inhaled by sprayers determined by personal measurements were calculated to be 30–235μg d-phenothrin per 100g spray applied (30% in the respirable fraction for Arrow Aircraft Disinsectant; 10% for Aircraft Disinsectant Denka). If passengers will board, e.g., 20min after the end of the disinsection operation, inhalation exposure is estimated to be practically negligible. Also possible dermal exposure from residues in seats and headrests is very low for passengers during the flight. Therefore any health effects for passengers and crew members are very unlikely. [Copyright &y& Elsevier]

In this paper an algorithm is presented which enables high-resolution ocean surface wind fields to be retrieved from the advanced synthetic aperture radar (ASAR) data acquired by the European remote sensing satellite ENVISAT. Wind directions are extracted from wind-induced streaks that are visible in ASAR images at scales above 200 m and that are approximately in line with the mean surface wind direction. Wind speeds are derived from the normalized radar cross section (NRCS) and image geometry of the calibrated ASAR images, together with the local ASAR-retrieved wind direction. Therefore the empirical C-band model CMOD4, which describes the dependency of the NRCS on wind and image geometry, is used. CMOD4 is a semi-empirical model, which was originally developed for the scatterometer of the European remote sensing satellites ERS-1 and 2 operating at C-band with vertical polarization. Consequently, CMOD4 requires modification when applied to ASAR images that were acquired with horizontal polarization in transmitting and receiving. This is performed by considering the polarization ratio of the NRCS. To demonstrate the applicability of the algorithm, wind fields were computed from several ENVISAT ASAR images of the North Sea and compared to atmospheric model results of the German weather service. [ABSTRACT FROM AUTHOR]

Summary: Exposure measurements were carried out in parked aircrafts during and after application of a biocide aerosol spray (simulated in-flight spraying). The aerosol product SRA spray (Standard Reference Aerosol Spray) was used for spraying. Concentrations of the pyrethrins – the active ingredients – in the air of the passenger cabin (airborne particles, measured during spray application and 40 minutes afterwards) varied from 11 to 65 μg/m3; those of the synergist piperonyl butoxide were 200 – 485 μg/m3. The concentrations on surfaces of the cabin furniture differed widely. Low concentrations were determined on surfaces in vertical positions (median values: pyrethrins ≤2 ng/cm2; piperonyl butoxide ≤17 ng/cm2), while under seats, on seats and on headrests the concentrations were up to 55.5 ng/cm2 for pyrethrins and 1162.5 ng/cm2 for piperonyl butoxide (median values). The inhaled doses for sprayers (using 100 g of spray) and persons sitting in the passenger cabin were calculated to be 17 μg for pyrethrins and 200 μg for piperonyl butoxide (maximum values). Maximum total external body doses for the applicators during spraying were 830 μg for pyrethrins and 8840 μg for piperonyl butoxide. The potential dermal dose for persons sitting in the passenger cabin was about a factor of two lower. [Copyright &y& Elsevier]

Amino acids are regarded as the nitrogen ‘currency’ of plants. Amino acids can be taken up from the soil directly or synthesized from inorganic nitrogen, and then circulated in the plant via phloem and xylem. AtAAP3, a member of the Amino Acid Permease (AAP) family, is mainly expressed in root tissue, suggesting a potential role in the uptake and distribution of amino acids. To determine the spatial expression pattern of AAP3, promoter–reporter gene fusions were introduced into Arabidopsis. Histochemical analysis of AAP3 promoter–GUS expressing plants revealed that AAP3 is preferentially expressed in root phloem. Expression was also detected in stamens, in cotyledons, and in major veins of some mature leaves. GFP–AAP3 fusions and epitope-tagged AAP3 were used to confirm the tissue specificity and to determine the subcellular localization of AtAAP3. When overexpressed in yeast or plant protoplasts, the functional GFP–AAP3 fusion was localized in subcellular organelle-like structures, nuclear membrane, and plasma membrane. Epitope-tagged AAP3 confirmed its localization to the plasma membrane and nuclear membrane of the phloem, consistent with the promoter–GUS study. In addition, epitope-tagged AAP3 protein was localized in endodermal cells in root tips. The intracellular localization suggests trafficking or cycling of the transporter, similar to many metabolite transporters in yeast or mammals, for example, yeast amino acid permease GAP1. Despite the specific expression pattern, knock-out mutants did not show altered phenotypes under various conditions including N-starvation. Microarray analyses revealed that the expression profile of genes involved in amino acid metabolism did not change drastically, indicating potential compensation by other amino acid transporters. [ABSTRACT FROM PUBLISHER]

We examined the contribution of perceptual processes to cognitive ability with respect to stimulus complexity, response mode, level of encoding, and attention. The participants were 124 university students. Stimulus complexity due to presenting both irrelevant and relevant information led to a substantial increase in correlation between reaction time and measures of cognitive ability. Two different response modes, correctness in brief exposures and motor response, yielded correlations of equal size. Three levels of encoding were compared. These were related to signal detection, stimulus discrimination, and stimulus identification. It was very interesting to find that the correlation of the level relating to stimulus discrimination exceeded the other correlations. The consideration of attention showed clearly that about 70% of the common variance of perceptual processes and cognitive ability were due to attentive processes and 30% to preattentive processes. [Copyright &y& Elsevier]

For the growth of the photovoltaic industry, it seems inevitable to create an independent feedstock supply with solar grade high-purity silicon, because the availability of the hitherto used by-products in the electronic silicon industry is limited and will not increase reasonably within the next 10–15 years.One of the results of the study “Present and likely future bottlenecks analysis for a sustainable photovoltaic policy” carried out by Bayer and Life, within EPIA, sponsored by the European Commission, within the ALTENER programme, shows that the feedstock used to date, based on electronic grade silicon Scraps is already limiting the PV market expansion even if a true shortage is not expected before 2004–2005 according to a “low growing PV market scenario”. This conclusion implies that a new silicon feedstock not depending on electronic grade silicon production chain must be available on the market from the years 2004 to 2005.Bayer evaluated different ways for the production of solar grade silicon with a capacity of upto 5000 mt/yr. By calculating different routes, it seems possible to install a 5000 t plant by an investment of 110 Mio. Euro and to sell silicon feedstock with a price level of 12–15 Euro/kg. Bayer has been developing a suitable process and the new owner, the Deutsche Solar GmbH, is considering what effort is necessary for a pilot production plant.The feedstock situation is discussed under the aspect of availability of different materials and the efforts under consideration by different parties. [Copyright &y& Elsevier]

A method for inhalative exposure of minipigs to aerosols and gases has been developed. Minipigs are exposed via mask inhalation to the test substance using a computer-controlled exposure system that permits simultaneous exposure of groups of four animals in parallel to different controlled dose levels. We studied inhalation treatment of verapamil, a cardiovascular drug, and show good absorption and favorable pharmacokinetics when compared with iv drug application. The results shown in this study encourage inhalation studies with the Göttingen minipig. [ABSTRACT FROM AUTHOR]

Presents a revision of Cattell's Investment Theory which assumes that learning mediates the influence of fluid on crystallized intelligence. Cognitive basis of fluid intelligence; Major properties of the cognitive basis of fluid intelligence; Major characteristic of the suggested revision of Cattell's Investment theory.

This article describes a mechanistic two-compartmental model to simulate the disposition by dissolution and particulate clearance of particles deposited in the pulmonary region of the lung. The model provides a general solution for the size distribution of particles in the surfactant layer of the alveolar surface and in the cell plasma of alveolar macrophages. Thus it allows for different dissolution rates in the two compartments and accounts for potentially different kinetics and/or biological effects of particles and their solute in surrounding fluids. The input parameters are, among others, the size distribution density function of the deposited particles and the time constants characterizing the dissolution process as well as phagocytosis rate and particle transport by macrophages to the tracheobronchial tract. Relevant dose parameters such as retained and dissolved mass can be calculated from the temporally retained size distributions. For the first time, this theoretical presentation considers the polydispersity of aerosol particles deposited in the lung and thus provides an indispensable mathematical basis for a multicompartmental retention model that may combine particulate removal from the pulmonary region and the lymph nodes by a competition of the rates of dissolution and particulate clearance in all relevant lung model compartments. [ABSTRACT FROM AUTHOR]

Focuses on a study on wind retrieval over the ocean using synthetic aperture radar (SAR) with C-band with horizontal polarization in transmitting and receiving. Development of algorithms using ScanSAR aboard the Canadian satellite RADARSAT-1; Investigated data sets; Details on SAR wind retrieval; Comparison of wind speeds from ScanSAR to ERS-2 scatterometers; Comparison of ScanSAR to high resolution limited area model.

Presents a study that investigated Bayesian retrodiction for interacting multiple-model (IMM) to multiple hypothesis tracking (MHT) methods concerning air surveillance. Importance of IMM-MHT filtering in solving target-tracking problems; Application of statistical models in Bayesian filtering and retrodiction; Discussion on the IMM-MHT simulation results.

Three particle size fractions of airborne dust are defined in Euro pean and U.S. standards for health-related dust measurements at the workplace: the respirable, the thoracic, and the inhalable fraction. We developed a novel instrument for personal, time-resolved concentration monitoring and sampling of these three fractions. The instrument combines inertial classification, filter sam pling, and photometric aerosol detection. It consists of a two-stage virtual impactor (cut-off diameters of 4 and 10 mu m), three filters, and three light scattering photometers. The virtual impactor serves as a particle size classifier and a coarse particle concentrator. This enrichment compensates for the decreasing particle mass-based photometric sensitivity with increasing particle diameter. The optical sensors are calibrated in-situ via the mass concentrations obtained gravimetrically from the filter samples. The device operates at a flow rate of 3.1 l min. There is strong agreement between the experimentally determined particle size-dependent collection efficiencies and the definition curves of the corresponding dust fractions. The size dependence of the sensitivity of the inertial concentrator and photometric detection units follow the definition curves qualitatively. Exposure data were obtained for different workplace environments characterized by temporally and spatially highly fluctuating concentrations. The field measurements have shown that the instrument is practicable under rough industrial conditions and that it enables a more comprehensive and more realistic characterization of the individ ual exposure of workers to health-endangering dusts than was previously possible. [ABSTRACT FROM AUTHOR]

In stochastic estimation problems, we aim to estimate an unknown state of interest given a set of measurements received from noisy sensory devices, such as radar, light detection and ranging, etc. A common model of the measurements’ random error is white Gaussian noise. This noise model is usually used to derive an estimator of the unknown state; accordingly, the state is described as a random variable with a Gaussian density. In some applications, the unknown state is known to take only positive values, e.g., estimating size or dimension. In such a case, the classical approaches based on Gaussian densities might fail, i.e., produce a negative value. In this article, a recursive Bayesian filter is proposed based on modeling the unknown state as Wishart distributed random matrix. This model ensures that the probability densities of the random variables are restricted to positive real values, even though the measurement’s noise is still modeled as white Gaussian noise. The feasibility of the proposed Bayesian–Wishart filter is demonstrated within the framework of extended target tracking. A target contour measurement model of a symmetric star-convex shape is presented and integrated in the proposed filter to track the target’s extent. [ABSTRACT FROM AUTHOR]

The application of biocidal products by foam is considered an alternative to droplet spraying when disinfecting surfaces or fighting infestations. Inhalation exposure to aerosols containing the biocidal substances cannot be ruled out during foaming. In contrast to droplet spraying, very little is known about aerosol source strength during foaming. In this study, the formation of inhalable aerosols was quantified according to the aerosol release fractions of the active substance. The aerosol release fraction is defined as the mass of active substance transferred into inhalable airborne particles during foaming, normalised to the total amount of active substance released through the foam nozzle. Aerosol release fractions were measured in control chamber experiments where common foaming technologies were operated according to their typical conditions of use. These investigations include foams generated mechanically by actively mixing air with a foaming liquid as well as systems that use a blowing agent for foam formation. The values of the aerosol release fraction ranged from 3.4 × 10−6 to 5.7 × 10−3 (average values). For foaming processes based on mixing air and the foaming liquid, the release fractions could be correlated to the process and foam parameters such as foam exit velocity, nozzle dimensions, and foam expansion ratio. [ABSTRACT FROM AUTHOR]

This correspondence shows that the expression for the marginal density of the kinematic state in [1], which is valid only if the kinematic state is fully observable by the sensor, can be generalized. Our second comment concerns the direct integration of a scaling factor for the extent estimate. Thirdly, we show an equivalent update step based on sequential processing of single measurements (instead of the indirect parameters "mean measurement" and "measurement spread" in [1]). [ABSTRACT FROM PUBLISHER]

In target tracking applications, the full information on the kinematic target states accumulated over a certain time window up to the present time is contained in the joint probability density function of these state vectors, given the time series of all sensor data. This joint density may also be called an accumulated state density (ASD) and provides a unified treatment of filtering and retrodiction insofar as by marginalizing the ASD, the standard filtering and retrodiction densities are obtained. In addition, ASDs fully describe the posterior correlations between the states at different instants of time. The notion of ASDs and closed formulae for calculating them are discussed. The practical usefulness of considering ASDs is illustrated by applications, where out-of-sequence (OoS) measurements are to be processed within the framework of a centralized measurement fusion architecture, i.e., when the sensor data do not arrive in the temporal order, in which they were produced. The approach can be applied to Kalman, multiple hypothesis tracking (MHT), and interacting multiple model (IMM) filtering. [ABSTRACT FROM AUTHOR]

Summary Transport processes across the plasma membrane of leaf vascular tissue are essential for transport and distribution of assimilates. In potato, leaves are the predominant sites for nitrate reduction and amino acid biosynthesis. From there, assimilated amino acids are exported through the phloem to supply tubers with organic nitrogen. To study the role of amino acid transporters in long-distance transport and allocation of organic nitrogen in potato plants, a gene encoding a functional, leaf-expressed amino acid permease StAAP1 was isolated. Similar to the sucrose transporter SUT1, StAAP1 expression was induced during the sink-to-source transition, indicating a role in phloem loading. To test the role of StAAP1, expression was inhibited by an antisense approach. Transgenic plants with reduced StAAP1 expression were phenotypically indistinguishable from wild type, as were photosynthetic capacity and tuber yield. However, tubers from antisense StAAP1 plants showed up to 50% reduction in free amino acid contents. In comparison, starch content was not affected or tended to increase relative to wild type. The reduction in all amino acids except aspartate in the antisense plants is consistent with the properties of amino acid permeases (AAPs) found in heterologous systems. The results demonstrate an important role for StAAP1 in long-distance transport of amino acids and highlight the importance of plasma membrane transport for nutrient distribution in plants. [ABSTRACT FROM AUTHOR]

Three different building blocks have been synthesised and used for the synthesis of linear triazole linked pseudo oligosaccharides with copper(I)-catalysed cycloaddition (CuAAC). Ethynylferrocene has been used as analytical probe to improve the UV/Vis properties and HPLC methods have been used and optimised for the analysis of the pseudo oligosaccharides. The smallest ones have been isolated and characterised by analytical HPLC, NMR, ESI-MS and elemental analysis. [ABSTRACT FROM AUTHOR]

The discrimination of closely spaced targets is a major challenge in the ground target-tracking domain based on measurements of airborne ground moving target indication radar. Being a standard output of modern radar systems, the measured signal strength of a radar detection can be used to estimate the characteristic mean radar cross section (RCS) of a ground target, which is then used as additional target attribute information to improve the tracking performance in situations with closely spaced targets. For this method to work, the fluctuations of the target RCS are assumed to follow the analytically tractable Swerling-I and Swerling-III cases. In this work, the RCS estimation scheme originally developed for air targets [1, 2] is generalized to ground-moving objects and then implemented into the Gaussian mixture cardinalized probability hypothesis density filter. The performance of the resulting algorithm is analyzed based on single and multiple-target simulation scenarios. In the latter case, a modified version of the optimal subpattern assignment metric that also accounts for labeling errors is used. [ABSTRACT FROM AUTHOR]

A field study was carried out in order to derive a factor for the conversion of historic worker exposure data on airborne beryllium (Be) obtained by sampling according to the 37-mm closed faced filter cassette (CFC) ‘total' particulate method into exposure concentration values to be expected when sampling using the ‘Gesamtstaubprobenahmesystem' (GSP) inhalable sampling convention. Workplaces selected to represent the different copper Be work processing operations that typically occur in Germany and the EU were monitored revealing a broad spectrum of prevailing Be size distributions. In total, 39 personal samples were taken using a 37-mm CFC and a GSP worn side by side for simultaneous collection of the ‘total' dust and the inhalable particulates, respectively. In addition, 20 static general area measurements were carried out using GSP, CFC, and Respicon samplers in parallel, the latter one providing information on the extra-thoracic fraction of the workplace aerosol. The study showed that there is a linear relationship between the concentrations measured with the CFC and those measured with the GSP sampler. The geometric mean value of the ratios of time-weighted average concentrations determined from GSP and CFC samples of all personal samples was 2.88. The individual values covered a range between 1 and 17 related to differences in size distributions of the Be-containing particulates. This was supported by the area measurements showing that the conversion factor increases with increasing values of the extra-thoracic fraction covering a range between 0 and 79%. [ABSTRACT FROM AUTHOR]

This article presents advances in determining the maximum estimation accuracy, as well as estimating the state for a piecewise maneuvering target with unknown maneuver change times, using passively obtained azimuth (bearings only), azimuth rate, and range measurements. We investigate two types of piecewise target motion and calculate the maximum estimation accuracy represented by the Cramer-Rao bound (CRB). Moreover, an estimation approach for estimating the target state, including the unknown maneuver change times, is developed on the basis of a maximum likelihood estimator. For two typical scenarios considering each motion model, we present and compare the results of the accuracy study, as well as the results for state estimation. Here, Monte Carlo simulations show that the estimator is able to attain the CRB. [ABSTRACT FROM PUBLISHER]

Random matrices are widely used to estimate the extent of an elliptically contoured object. Usually, it is assumed that the measurements follow a normal distribution, with its standard deviation being proportional to the object’s extent. However, the random matrix approach can filter the center of gravity and the covariance matrix of measurements independently of the measurement model. This work considers the whole chain from data acquisition to the linear Kalman Filter with extension estimation as a reference plant. The input is the (unknown) ground truth (position and extent). The output is the filtered center of gravity and the filtered covariance matrix of the measurement distribution. A virtual measurement model emulates the behavior of the reference plant. The input of the virtual measurement model is adapted using the proposed algorithm until the output parameters of the virtual measurement model match the result of the reference plant. After the adaptation, the input to the virtual measurement model is considered an estimation for position and extent. The main contribution of this paper is the reference model concept and an adaptation algorithm to optimize the input of the virtual measurement model. [ABSTRACT FROM AUTHOR]

Abstract: A multistatic passive radar system exploits illuminators of opportunity like radio or television transmitters for target surveillance. In this paper we analyze the use of the illumination of television or radio stations broadcasting digital signals (DAB/DVB-T) from a target tracking view point. An important characteristic of this type of illuminators is the joint operation of several illuminators in a single frequency network (SFN). As a consequence it is a priori unknown which measurement belongs to which illuminator. This property expands the typical association task of associating measurements with targets by the task of associating measurements with illuminators. In this paper we present a comprehensive concept for target tracking in DAB/DVB-T networks accounting for the characteristics of this signal. The derived algorithms will be tested with respect to numerical simulations including a sensitivity study for parameter mismatch between simulations and tracking model. [Copyright &y& Elsevier]

Provision of food is a prerequisite for the functioning of human society. Cropland where food and feed are grown is the central, limiting resource for food production. The amount of cropland needed depends on population numbers, average food consumption patterns, and output per unit of land, Around the globe, these factors show large differences. We use data from the Food and Agriculture Organization to consistently assess subcontinental dynamics of how much land was needed to supply the prevailing diets during a span of 46 y, from 1961 to 2007. We find that, in most regions, diets became richer while the land needed to feed one person decreased. A decomposition approach is used to quantify the contributions of the main drivers of cropland requirements for food: changes in population, agricultural technology, and diet. We compare the impact of these drivers for different subcontinents and find that potential land savings through yield increases were offset by a combination of population growth and dietary change. The dynamics of the three factors were the largest in developing regions and emerging economies. The results indicate an inverse relationship between the two main driven behind increased land requirements for food: with socioeconomic development population growth decreases and, at the same time, diets become richer. In many regions. dietary change may override population growth as major driver behind land requirements for food in the near future. [ABSTRACT FROM AUTHOR]

The task of tracking extended objects or (partly) unresolvable group targets raises new challenges for both data association and track maintenance. Due to limited sensor resolution capabilities, group targets (i.e., a number of closely spaced targets moving in a coordinated fashion) may show a similar detection pattern as extended objects, namely a varying number of detections whose spread is determined by both the statistical sensor errors as well as the physical extension of the group or extended object. In both cases, tracking and data association under the “one target–one detection” assumption are no longer applicable. This paper deals with the problem of maintaining a track for an extended object or group target with varying number of detections. Herein, object extension is represented by a symmetric positive definite random matrix. A recently published Bayesian approach to tackling this problem is analyzed and discussed. From there, a new approach is derived that is expected to overcome some of the weaknesses the mentioned Bayesian approach suffers from in certain applications. [ABSTRACT FROM PUBLISHER]

This paper considers recursive tracking of one mobile emitter using a sequence of time difference of arrival (TDOA) and frequency difference of arrival (FDOA) measurement pairs obtained by one pair of sensors. We consider only a single emitter without data association issues (no missed detections or false measurements). Each TDOA measurement defines a region of possible emitter locations around a unique hyperbola. This likelihood function is approximated by a Gaussian mixture, which leads to a dynamic bank of Kalman filters tracking algorithm. The FDOA measurements update relative probabilities and estimates of individual Kalman filters. This approach results in a better track state probability density function approximation by a Gaussian mixture, and tracking results near the Cramér-Rao lower bound. Proposed algorithm is also applicable in other cases of nonlinear information fusion. The performance of proposed Gaussian mixture approach is evaluated using a simulation study, and compared with a bank of EKF filters and the Cramér-Rao lower bound. [ABSTRACT FROM AUTHOR]

Background: Like many other plant species, Arabidopsis uses arginine (Arg) as a storage and transport form of nitrogen, and proline (Pro) as a compatible solute in the defence against abiotic stresses causing water deprivation. Arg catabolism produces ornithine (Orn) inside mitochondria, which was discussed controversially as a precursor for Pro biosynthesis, alternative to glutamate (Glu). Results: We show here that ornithine-δ-aminotransferase (δOAT, At5g46180), the enzyme converting Orn to pyrroline-5-carboxyl ate (P5C), is localised in mitochondria and is essential for Arg catabolism. Wildtype plants could readily catabolise supplied Arg and Orn and were able to use these amino acids as the only nitrogen source. Deletion mutants of δOAT, however, accumulated urea cycle intermediates when fed with Arg or Orn and were not able to utilize nitrogen provided as Arg or Orn. Utilisation of urea and stress induced Pro accumulation were not affected in T-DNA insertion mutants with a complete loss of δOAT expression. Conclusion: Our findings indicate that δOAT feeds P5C exclusively into the catabolic branch of Pro metabolism, which yields Glu as an end product. Conversion of Orn to Glu is an essential route for recovery of nitrogen stored or transported as Arg. Pro biosynthesis occurs predominantly or exclusively via the Glu pathway in Arabidopsis and does not depend on Glu produced by Arg and Orn catabolism. [ABSTRACT FROM AUTHOR]

Summary Amides and acidic amino acids represent the major long distance transport forms of organic nitrogen. Six amino acid permeases (AAPs) from Arabidopsis mediating transport of a wide spectrum of amino acids were isolated. AAPs are distantly related to plasma membrane amino acid transport systems N and A and to vesicular transporters such as VGAT from mammals. A detailed comparison of the properties by electrophysiology after heterologous expression in Xenopus oocytes shows that, although capable of recognizing and transporting a wide spectrum of amino acids, individual AAPs differ with respect to specificity. Apparent substrate affinities are influenced by structure and net charge and vary by three orders of magnitude. AAPs mediate cotransport of neutral amino acids with one proton. Uncharged forms of acidic and basic amino acids are cotransported with one proton. Since all AAPs are differentially expressed, different tissues may be supplied with a different spectrum of amino acids. AAP3 and AAP5 are the only transporters mediating efficient transport of the basic amino acids. In vivo competition shows that the capability to transport basic amino acids in planta might be overruled by excess amides and acidic amino acids in the apoplasm. With the exception of AAP6, AAPs do not recognize aspartate; only AAP6 has an affinity for aspartate in the physiologically relevant range. This property is due to an overall higher affinity of AAP6 for neutral and acidic amino acids. Thus AAP6 may serve a different role either in cooperating with the lower affinity systems to acquire amino acids in the low concentration range, as a system responsible for aspartate transport or as an uptake system from the xylem. In agreement, a yeast mutant deficient in acidic amino acid uptake at low aspartate concentrations was complemented only by AAP6. Taken together, the AAPs transport neutral, acidic and cationic amino acids, including the major transport forms, i.e. glutamine,... [ABSTRACT FROM AUTHOR]

The contribution of perceptual processes to the correlation between measures of sustained attention and intelligence was investigated in considering computerized and paper-pencil tests of sustained attention. Perceptual processes were represented by tasks demanding signal detection and stimulus discrimination. A total of 117 participants completed two attention tests, as well as two tests that required signal detection and stimulus discrimination. Intelligence was measured by means of Advanced Progressive Matrices (APM) and Berliner Intelligenzstruktur-Test (BIS). Structural equation modeling showed that intelligence was best predicted by one independent latent variable, which included loadings of sustained attention, speed of signal detection, and of stimulus discrimination. The investigation of the structure of prediction revealed speed of stimulus discrimination and genuine sustained attention as major predictors of intelligence. (C) 2001 Elsevier Science Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

Chronic toxic and carcinogenic effects of gasoline engine exhaust inhalation were investigated in rats. The exhaust from the combustion of commercial fuel containing 30 ppm ferrocene additive was compared to exhaust from the same fuel without ferrocene. This study was part of a procedure to get a special authorization for the use of ferrocene as gasoline additive according to the German Gasoline Lead Act. To generate the exhausts, pairs of engines of the same type and age were operated on computer-controlled test benches in a combined urban–freeway driving cycle. The engines were equipped with three-way catalysts and lambda sensors. Rats inhaled the exhausts after dilution at ratios of about 1:20 and 1:40 for 18 h/day, 5 days/wk for 12 mo (chronic toxicity study) or for 24 mo followed by 6 mo of clean air (carcinogenicity study). The limiting factor for the exhaust concentration was the relative humidity of the exposure atmosphere. At defined intervals, body weight and food consumption, parameters of clinical chemistry, hematology, bronchoalveolar lavage (BAL), and mechanical lung function were measured, as well as lung clearance and particle retention in the lungs. In the high-dose groups and the controls the complete organ/tissue spectrum was investigated histopathologically, and in the low-dose groups the respiratory tract. Only slight exposure-related effects could be detected, like a loss in the background iron content of the cell pellet of the bronchoalveolar lavage fluid and cytoplasmic inclusions and goblet-cell hyperplasias in the nasal cavity. Between the clean-air controls and the exhaust-exposed groups, no exposure-related differences occurred in body weight development, mortality incidences, or any of the clinical investigations. Ninety-two to 94% of the animals developed age-related tumors, predominantly in the mammary glands, uterus, adrenals, thyroid, and pituitary. In the respiratory tract a total of five tumors was found: one in the controls and four in the low-dose groups. No physical, chemical, or toxicological differences between the exhausts from fuel without or with ferrocene were demonstrated. [ABSTRACT FROM AUTHOR]

Chronic toxic and carcinogenic effects of gasoline engine exhaust inhalation were investigated in rats. The exhaust from the combustion of commercial fuel containing 30 ppm ferrocene additive was compared to exhaust from the same fuel without ferrocene. This study was part of a procedure to get a special authorization for the use of ferrocene as gasoline additive according to the German Gasoline Lead Act. To generate the exhausts, pairs of engines of the same type and age were operated on computer-controlled test benches in a combined urban-freeway driving cycle. The engines were equipped with three-way catalysts and lambda sensors. Rats inhaled the exhausts after dilution at ratios of about 1.20 and 1:40 for 18 h/day, 5 days/wk for 12 mo (chronic toxicity study) or for 24 mo followed by 6 mo of clean air (carcinogenicity study). The limiting factor for the exhaust concentration was the relative humidity of the exposure atmosphere. At defined intervals, body weight and food consumption, parameters of clinical chemistry, hematology, bronchoalveolar lavage (BAL), and mechanical lung function were measured, as well as lung clearance and particle retention in the lungs. In the high-dose groups and the controls the complete organ/tissue spectrum was investigated histopathologically, and in the low-dose groups the respiratory tract. Only slight exposure-related effects could be detected, like a loss in the background iron content of the cell pellet of the bronchoalveolar lavage fluid and cytoplasmic inclusions and goblet-cell hyperplasias in the nasal cavity. Between the clean-air controls and the exhaust-exposed groups, no exposure-related differences occurred in body weight development, mortality incidences, or any of the clinical investigations. Ninety-two to 94% of the animals developed age-related tumors, predominantly in the mammary glands, uterus, adrenals, thyroid, and pituitary. In the respiratory tract a total of five tumors was found: one in the controls and four in the low-dose groups. No physical, chemical, or toxicological differences between the exhausts from fuel without or with ferrocene were demonstrated. [ABSTRACT FROM PUBLISHER]

• Fumes from oxidized asphalt (OA), corresponding to workplace fumes, were collected. • Nose-only exposure of rats to fume of OA at 158 and 536 mg/m3 caused adverse effects in dams. • Nose-only exposure to fumes from OA at 536 mg/m3 did not induce any fetal abnormalities. The prenatal developmental toxicity of the fumes of oxidised asphalt (OA) was tested by nose-only inhalation in the rat. The test material was generated by collecting fumes from the headspace of storage tanks filled with OA. The composition of these fumes was matched to fumes sampled at a workplace where the same OA was applied in a pour-and-roll operation, representing occupational exposure with high concentrations of fumes to not underestimate the possible hazard. In the main study, dams were exposed to 0, 53, 158 and 536 mg/m3 of fume (as total organic mass), for 6 h/day for 19 days p.c. The maternal NOAEC was 53 mg/m³ (lowest dose tested). In the high-dose group treatment-related effects on body weight gain were seen. In the mid- and high-dose groups treatment-related effects on food consumption, lung weights, and histopathological changes in lungs and the upper respiratory tract were observed. The NOAEC for prenatal developmental toxicity was 536 mg/m³ since no exposure-related effects were found in any of the exposure groups for any of the investigated reproductive endpoints. Furthermore, nose-only exposure to OA fumes in concentrations up to 536 mg/m³ from days 1–19 p.c. did not induce any significant fetal abnormalities. [ABSTRACT FROM AUTHOR]

• Fumes from bitumen corresponding to occupational exposures were collected. • Nose-only exposure to bitumen fume at 151 and 482 mg/m3 caused weight loss in dams. • Nose-only exposure to fumes from bitumen did not induce fetal abnormalities. The prenatal developmental toxicity of bitumen fume was tested by nose-only inhalation in the rat. The fumes for exposure were collected from the headspace of a storage tank filled with a bitumen corresponding in composition to an anticipated worst-case occupational exposure. The composition of these fumes was compared to actual paving site fumes to ensure its representativeness for workplace exposures. In a dose-range-finding study male and female rats were exposed to 0, 103, 480 or 1043 mg/m3 of fume (as total organic mass), for 6 h/day during 20 days post conception (p.c.). Dose-related effects on body weight and lungs were observed in the mid- and high-dose groups. In the main study, dams were exposed to 0, 52, 151 and 482 mg/m3 of fume, for 6 h/day during 19 days p.c. The maternal NOAEL was 52 mg/m³. In the high-dose group treatment-related effects on body weight (gain), food consumption, lung weights, and histopathological changes in lungs and larynx were observed. In the mid-dose group only histopathological changes in the larynx and lungs were found. The NOAEL for prenatal developmental toxicity was 151 mg/m³ based on reduced fetal weight in the high-dose group (482 mg/m³). However, these changes are most likely a consequence of the maternal toxicity, in particular the reduction of maternal body weight gain by 26 % as compared to control. Nose-only exposure to bitumen fumes in concentrations up to 482 mg/m³ from days 1–19 p.c. did not induce any significant fetal anomalies. [ABSTRACT FROM AUTHOR]

During their first year of growth, overwintering biennial plants transport Suc through the phloem from photosynthetic source tissues to storage tissues. In their second year, they mobilize carbon from these storage tissues to fuel new growth and reproduction. However, both the mechanisms driving this shift and the link to reproductive growth remain unclear. During vegetative growth, biennial sugar beet (Beta vulgaris) maintains a steep Suc concentration gradient between the shoot (source) and the taproot (sink). To shift from vegetative to generative growth, they require a chilling phase known as vernalization. We studied sugar beet sink-source dynamics upon vernalization and showed that before flowering, the taproot underwent a reversal from a sink to a source of carbohydrates. This transition was induced by transcriptomic and functional reprogramming of sugar beet tissue, resulting in a reversal of flux direction in the phloem. In this transition, the vacuolar Suc importers and exporters TONOPLAST SUGAR TRANSPORTER2;1 and SUCROSE TRANSPORTER4 were oppositely regulated, leading to the mobilization of sugars from taproot storage vacuoles. Concomitant changes in the expression of floral regulator genes suggest that these processes are a prerequisite for bolting. Our data will help both to dissect the metabolic and developmental triggers for bolting and to identify potential targets for genome editing and breeding. [ABSTRACT FROM AUTHOR]

The aerosol release during the professional application of two different isocyanate based two component spray systems was identified and the physicochemical properties of the released airborne aerosols were characterized. For this purpose, aerosol release fractions were measured using a mass balance method described by Schwarz and Koch. Besides the release of total aerosol mass special emphasis was directed to the content of free monomeric MDI (4,4′- and 2,4′-diphenylmethane diisocyanate) in three particle size fractions relevant for inhalation uptake: inhalable, thoracic, and respirable size fraction. Two products were investigated: a two component PUR (polyurethane) spray foam (Elastopor) and a polyurea spray coating (Elastocoat). The mass fraction of the applied products released with the overspray as inhalable aerosol is 6.3 × 10−4 (Elastopor) and 4.0 × 10−4 (Elastocoat). Of the released total overspray aerosol 75 or 80% were in the thoracic size range, and 26 or 47% in the respirable regime for the PUR spray foam or the polyurea spray coating, respectively. At the time point of release the content of monomeric MDI in the aerosol corresponds to the composition of the bulk product. However, analysis of air samples indicates that <1% of the spray foam aerosol mass release fraction is attributed to free monomeric 4,4′- and 2,4′-MDI. For the Spray Coating the monomeric MDI fraction is <0.1%. Higher oligomers of MDI and prereacted oligomeric reaction products make up a few percent of the aerosol. This results in a total fraction of 0.0023% (spray foam) and 0.00015% (spray coating), respectively, of the sprayed monomeric MDI that is transferred into an inhalable aged aerosol. This data demonstrates, that during professional spraying only a small fraction of the total applied mass is released as airborne aerosol. The potential distribution of the theoretically inhalable aerosol in the respiratory tract and a low residual monomer content is described, significantly contributing to a refined safety assessment of the spray applications at the workplaces. [ABSTRACT FROM AUTHOR]

Extended objects generate a variable number of multiple measurements. In contrast with point targets, extended objects are characterized with their size or volume, and orientation. Multiple object tracking is a notoriously challenging problem due to complexities caused by data association. This paper develops a box particle filter (box PF) method for multiple extended object tracking, and for the first time, it is shown how interval-based approaches can deal efficiently with data association problems and reduce the computational complexity of the data association. The box PF relies on the concept of a box particle. A box particle represents a random sample and occupies a controllable rectangular region of nonzero volume in the object state space. A theoretical proof of the generalized likelihood of the box PF for multiple extended objects is given based on a binomial expansion. Next, the performance of the box PF is evaluated using a challenging experiment with the appearance and disappearance of objects within the area of interest, with real laser rangefinder data. The box PF is compared with a state-of-the-art particle filter with point particles. Accurate and robust estimates are obtained with the box PF, both for the kinematic states and extent parameters, with significant reductions in computational complexity. The box PF reduction of computational time is atleast 32% compared with the particle filter working with point particles for the experiment presented. Another advantage of the box PF is its robustness to initialization uncertainty. [ABSTRACT FROM AUTHOR]

The effects of coupling between the atmospheric model of the Consortium for Small-Scale Modelling-Climate Limited-area Modelling (CCLM) and the wind wave model (WAM) on the lower atmosphere within the North Sea area are studied. Due to the two-way coupling between the models, the influences of wind waves and the atmosphere on each other can be determined. This two-way coupling between these models is enabled through the introduction of wave-induced drag into CCLM and updated winds into WAM. As a result of wave-induced drag, different atmospheric parameters are either directly or indirectly influenced by the wave conditions. The largest differences between the coupled and reference model simulation are found during storm events as well as in areas of steep gradients in the mean sea level pressure, wind speed or temperature. In the two-way coupled simulation, the position and strength of these gradients vary, compared to the reference simulation, leading to differences that spread throughout the entire planetary boundary layer and outside the coupled model area, thereby influencing the atmosphere over land and ocean, although not coupled to the wave model. Ultimately, the results of both model simulations are assessed against in situ and satellite measurements, with a better general performance of the two-way coupled simulation with respect to the observations. [ABSTRACT FROM AUTHOR]

In this study, the effects of coupling an atmospheric model and a wind wave model on the lower atmosphere within the North Sea are studied. The two-way coupling of the models is enabled through an introduction of wave-induced drag in the atmospheric model and updated wind in the wind wave model. Due to the two-way coupling not only the effect of coupling an atmospheric model to the wind wave model on the wind waves can be analysed, but also the effect on the atmosphere are determined. This includes the effects on the exchange between the ocean and the atmosphere, as well as the effects within and above the boundary layer. As a result of the wave-induced drag many atmospheric parameters are directly or indirectly influenced by the wave conditions. The impact on the wind conditions at the surface is the most obvious effect of the wave-induced drag, but the changes due to two-way coupling also spread into higher parts of the atmosphere, also with changes above the boundary layer height. However, other parameters like fluxes between the ocean and atmosphere as well as the temperature are modified by the coupling within and above the boundary layer as well. By analysing the spatial distribution of the effects within the coupled area locations where the effects of the coupling are the largest are identified. Furthermore, the propagation of the changes due to the coupling within and also out of the coupled model area over the ocean and over different parts of Europe is assessed. Moreover, events with maximum impact of the two-way coupling on the atmosphere are identified. The coupled and uncoupled model data is compared to in-situ and remote sensing measurements in order to estimate the improvements due to the two-way coupling. [ABSTRACT FROM AUTHOR]