Ochratoxin A exposure assessment of the inhabitants of Lisbon during winter 2007/2008 through bread and urine analysis

A survey on the occurrence of ochratoxin A (OTA) in 41 bread samples was carried out in the Portuguese capital, Lisbon. Maize (5) and wheat bread (36) and 43 representative urine samples from the Lisbon region were assayed for OTA levels using immunoaffinity column cleanup (IAC) and HPLC with fluorimetric detection (LC–FD). The percentage of OTA-positive samples was slightly higher for maize bread (80%) than wheat bread (70.8%), although, due to its higher consumption, the latter contributes more to OTA exposure, featuring a higher estimated daily intake (EDI). In the urine samples analyzed, both female and male residents displayed similarly high levels of OTA frequency and average contamination. In summary, OTA is a food contaminant of concern and may constitute a hazard for public health through consumption of cereal-based products.     

Heuristic algorithms for a storage location assignment problem in a chaotic warehouse

The extensive application of emerging technologies is revolutionizing warehouse management. These technologies facilitate working with complex and powerful warehouse management models in which products do not have assigned fixed locations (random storage). Random storage allows the utilization of the available space to be optimized. In this context, and motivated by a real problem, this article presents a model that looks for the optimal allocation of goods in order to maximize the storage space availability within the restrictions of the warehouse. For the proposed model a construction method, a local search algorithm and different metaheuristics have been developed. The introduced algorithms can also be used for other purposes such as to assess when and how it is convenient to perform relocation of stored items to improve the current level of storage space availability. Computational tests performed on a set of randomly generated and real warehouse instances show the effectiveness of the proposed methods.     

A potent integrin antagonist from a small library of cyclic RGD pentapeptide mimics including benzyl-substituted azabicycloalkane amino acids

A small library of cyclic RGD pentapeptide mimics, including benzyl-substituted azabicycloalkane amino acids, was synthesized with the aim of developing active and selective integrin antagonists. In vitro binding assays established one particular compound with affinity for both the alpha(v)beta(3) and the alpha(v)beta(5) integrins. The synthesis in solution and the in vitro screening of these RGD derivatives, as well as the determination of the conformational properties of the integrin ligands by spectroscopic and computational methods are described.     

Hyper-Rayleigh scattering with picosecond pulse trains

We propose a method for measuring hyper-Rayleigh scattering employing pulse trains produced by a Q-switched and mode-locked Nd:YAG laser. The use of the entire pulse train under the Q-switch envelope avoids the need of any device to scan the irradiance, as is usually done with nanosecond and femtosecond single-pulse lasers. To verify the feasibility of the technique, we performed measurements in different solutions of para-nitroaniline and compared the results with those obtained with nanosecond pulses. In both cases, the agreement with the hyperpolarizability values reported in the literature is about the same, but the measurements carried out with pulse trains are at least 20 times faster. Besides the advantage of acquisition speed, the use of pulse trains also allows the instantaneous inspection of slow luminescence contributions arising from multiphoton absorption.     

Large shift in source of fine sediment in the upper Mississippi river

Although sediment is a natural constituent of rivers, excess loading to rivers and streams is a leading cause of impairment and biodiversity loss. Remedial actions require identification of the sources and mechanisms of sediment supply. This task is complicated by the scale and complexity of large watersheds as well as changes in climate and land use that alter the drivers of sediment supply. Previous studies in Lake Pepin, a natural lake on the Mississippi River, indicate that sediment supply to the lake has increased 10-fold over the past 150 years. Herein we combine geochemical fingerprinting and a suite of geomorphic change detection techniques with a sediment mass balance for a tributary watershed to demonstrate that, although the sediment loading remains very large, the dominant source of sediment has shifted from agricultural soil erosion to accelerated erosion of stream banks and bluffs, driven by increased river discharge. Such hydrologic amplification of natural erosion processes calls for a new approach to watershed sediment modeling that explicitly accounts for channel and floodplain dynamics that amplify or dampen landscape processes. Further, this finding illustrates a new challenge in remediating nonpoint sediment pollution and indicates that management efforts must expand from soil erosion to factors contributing to increased water runoff.     

Estimated intake of the sweeteners,acesulfame-K and aspartame,from soft drinks,soft drinks based on mineral waters and nectars for a group of Portuguese teenage students

In a survey of levels of acesulfame-K and aspartame in soft drinks and in light nectars, the intake of these intense sweeteners was estimated for a group of teenage students. Acesulfame-K was detected in 72% of the soft drinks, with a mean concentration of 72 mg l^?1 and aspartame was found in 92% of the samples with a mean concentration of 89 mg l^?1. When data on the content of these sweeteners in soft drinks were analysed according to flavour, cola drinks had the highest mean levels for both sweeteners with 98 and 103 mg l^?1 for acesulfame-K and aspartame, respectively. For soft drinks based on mineral water, aspartame was found in 62% of the samples, with a mean concentration of 82 mg l^?1 and acesulfame-K was found in 77%, with a mean level of 48 mg l^?1. All samples of nectars contained acesulfame-K, with a mean concentration of 128 mg l^?1 and aspartame was detected in 80% of the samples with a mean concentration of 73 mg l^?1. A frequency questionnaire, designed to identify adolescents having high consumption of these drinks, was completed by a randomly selected sample of teenagers (n = 65) living in the city of Coimbra, in 2007. The estimated daily intakes (EDI) of acesulfame-K and aspartame for the average consumer were below the acceptable daily intakes (ADIs). For acesulfame-K, the EDI was 0.7 mg kg^?1 bw day^?1 for soft drinks, 0.2 mg kg^?1 bw day^?1 for soft drinks based on mineral waters, and 0.5 mg kg^?1 bw day^?1 for nectars, representing 8.0%, 2.2%, and 5.8% of the ADI, respectively. A similar situation was observed for aspartame. In this way, the EDI for soft drinks was 1.1 mg kg^?1 day^?1, representing only 2.9% of the ADI. In respect of nectars, the EDI was 0.2 mg kg^?1 bw day^?1, representing 0.5% of the ADI. Soft drinks based on mineral waters showed the lowest EDI values of 0.3 mg kg^?1 bw day^?1, accounting for 0.7% of the ADI.     

Molybdenum-on-chromium dual coating on steel

Molybdenum and chromium coatings were deposited on AISI 4130 steel using the Laser Induced Surface Improvement¹ (LISI™) process. In this process a mixture of precursor material is pre-placed on the substrate and then laser melted, resulting in the formation of a thin surface layer of alloy on the underlying material. First, a chromium coating was deposited on steel using the Cr-CrB₂ eutectic composition, and subsequently a molybdenum coating using the Mo-MoB eutectic composition was deposited on the chromium layer. Both the coatings have been individually characterized and compared using scanning electron microscope, energy dispersive spectrometry, Vicker’s hardness, X-ray diffraction, wear and erosion. The chromium layer exhibited superior erosion resistance (ASTM G76) while the molybdenum-on-chromium coating performed better in sliding wear (ASTM G77).     

Malta: housing and real estate, 1980–2005

Over the past two decades, private house ownership has expanded exponentially throughout Europe. Over the past decade, this has intensified with the desire and ability among wealthier northern Europeans to own second homes in sunnier climes. It has not only driven up house prices in pockets of Europe, but has also impacted on the social and cultural lives of local communities in ‘desirable locations’, having an adverse effect on the quality of the built environment. Lino Bianco describes the situation in Malta and how, after decades of largely uncontrolled development by real-estate investors, the government is taking stock and encouraging through investment in architectural education, and property legislation, the growth of an indigenous architecture that is contextual, sensitive and energy-conscious. Copyright © 2006 John Wiley & Sons, Ltd.     

Towards automated assessment of team performance by mimicking expert observers’ ratings

Cognition, Technology & Work - Automation is the holy grail of performance assessment. Cheap and reliable automated systems that produce consistent feedback on performance. Many such systems...     

Predictable TCR antigen recognition based on peptide scans leads to the identification of agonist ligands with no sequence homology

The potential of CD4+ T cells for cross-recognition of self and foreign Ags has important implications for the understanding of thymic selection, lymphocyte survival, and the occurrence of autoimmune diseases. Here, we define the extensive flexibility of Ag recognition for three human CD4+ autoreactive T cell clones (TCC) by using ligands with single and multiple amino acid (aa) substitutions. Our results demonstrate that the spectrum of tolerated ligands and the resulting stimulatory potency of peptides for a TCC can be predicted by the relative influence of each aa. Using this approach, we have identified stimulatory ligands not sharing a single aa in corresponding positions with the Ag used to establish the TCC. These results argue for an independent contribution of each aa in the peptide sequence to the affinity of the MHC/peptide complex to the TCR.