Association of Escherichia coli O157:H7 with preharvest leaf lettuce upon exposure to contaminated irrigation water.

Recent foodborne outbreaks have linked infection by enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 to the consumption of contaminated lettuce. Contamination via food handler error and on-the-farm contamination are thought to be responsible for several outbreaks. Though recent studies have examined the application of EHEC to store-bought lettuce, little is known about the attachment of EHEC to growing plants. We investigated the association of lettuce seedlings with EHEC O157:H7 strains implicated in lettuce or fruit outbreaks using hydroponic and soil model systems. EHEC strains that express the green fluorescent protein were observed by stereomicroscopy and confocal laser scanning microscopy to determine adherence patterns on growing lettuce seedlings. Bacteria adhered preferentially to plant roots in both model systems and to seed coats in the hydroponic system. Two of five nonpathogenic E. coli strains showed decreased adherence to seedling roots in the hydroponic system. EHEC was associated with plants in as few as 3 days in soil, and contamination levels were dose-dependent. EHEC levels associated with young plants inoculated with a low dose suggested that the bacteria had multiplied. These data suggest that preharvest crop contamination via contaminated irrigation water can occur through plant roots.     

5-Fluorouracil Treatment of CT26 Colon Cancer Is Compromised by Combined Therapy with IMMODIN

Due to the physiological complexity of the tumour, a single drug therapeutic strategy may not be sufficient for effective treatment. Emerging evidence suggests that combination strategies may be important to achieve more efficient tumour responses. Different immunomodulators are frequently tested to reverse the situation for the purpose of improving immune response and minimizing chemotherapy side effects. Immodin (IM) represents an attractive alternative to complement chemotherapy, which can be used to enhance the immune system after disturbances resulting from the side effects of chemotherapy. In the presented study, a model of CT26 tumor-bearing mice was used to investigate the effect of single IM or its combination with 5-fluorouracil (5-FU) on colon cancer cells. Our results highlight that the beneficial role of IM claimed in previous studies cannot be generalised to all chemotherapeutic drugs, as 5-FU toxicity was not increased. On the contrary, the chemotherapeutic anti-cancer efficacy of 5-FU was greatly compromised when combined with IM. Indeed, the combined treatment was significantly less effective regarding the tumour growth and animal survival, most probably due to the increased number of tumour-associated macrophages, and increased 5-FU cytotoxic effect related to kidneys and the liver.     

On the design of active inductors with current-controlled voltage sources

This paper presents a novel method of designing active inductors using current-controlled voltage sources (CCVSs). The basic idea consists of designing an equivalent inductor, using only capacitors and CCVSs. The signal-flow graph technique is used for this purpose. The CCVSs are emulated by means of nullator/norator pairs. These elements are then realized using second generation current conveyors (CCIIs), and a combination of CCIIs and operational transconductance amplifiers. In addition, a novel design of simulated inductors using operational transresistance amplifiers is presented. The proposed inductors were used to design filters. SPICE simulations are given to highlight viability and to show good reached results.     

Video mediated social interaction between groups: System requirements and technology challenges

This paper discusses results from research related to the use of television as a device that supports social interaction between close-knit groups in settings that include more than two locations, each location being potentially equipped with more than one camera. The paper introduces the notion of a framing experience, as a specific scenario or situation within which social communication takes place. It reports on the evaluation of some of the key attributes of social communication through semi-structured interviews, with 16 families across four European countries. The inferences drawn from this study are reduced to four system capabilities including the ability to support: excitement, engagement and entertainment; high quality, reliable audiovisual communications; flexibility and adaptability sufficient to support the unpredictable and reactive nature of human interaction and discourse. These system requirements are, in turn, reduced to a number of technology challenges which if solved will help enable effective social communications between groups, mediated by the television. These technology challenges include: high quality reliable audio visual communication; interaction orchestration, multimedia interpretation and multimedia composition. Finally the paper reflects on the impact the use of framing experiences, such as those described here, could have on strategy and policy for service providers and regulators.     

Projective filtering of time-aligned ECG beats

A method of electrocardiographic (ECG) signal processing developed by introduction of time synchronization into the method of nonlinear state-space projections is presented. It can be regarded as an extension of time averaging but contrary to usual averaging it preserves variability of ECG beats morphology. For this purpose, after the respective beats time alignment, the synchronized intervals of the signal undergo processing according to the rules of principal component analysis (PCA). PCA allows for determination of orthogonal basis functions which can be employed for approximation of the respective intervals. The operation is aimed to retain the deviations from the mean which result from the desired component changes and to reject the deviations caused by noise. The method's capabilities are investigated and some of its applications are presented.     

The thermogenic center in social wasps

In the social wasps Vespa orientalis and Paravespula germanica (Hymenoptera, Vespinae), a thermogenic center has been found in the dorsal part of the first thoracic segment. The temperature in this region of the prothorax is higher by 6-9 degrees C than that at the tip of the abdomen, and this in actively flying hornets outside the nest (workers, males or queens) as well as in hornets inside the nest that attend to the brood in the combs. On viewing the region from the outside, one discerns a canal or rather a fissure in the cuticle, which commences at the center of the dorsal surface of the prothorax and extends till the mesothorax. Thus the length of this canal or fissure is approximately 5-7 mm and it is seen to contain numerous thin hairs whose shape varies from that of the hairs alongside the structure. Beneath the cuticle in this region there are dorsoventral as well as longitudinal muscles in abundance, much the same as the musculature in the remaining thoracic segments (i.e. the meso- and metathorax), which activate the two pairs of wings. The canal-bearing segment is of course devoid of wings, and its dorsoventral muscles are attached to the cuticle, which in this region resembles a bowl harboring several layers of epithelium that boasts numerous butterfly-shaped tracheal branches. Additionally there are layers that display lymph-filled spaces and also perforated layers and depressions, and beneath all these is a lace-like layer that also coats the cuticle's hollows. Underneath the cuticle proper, there are numerous large mitochondria and tracheae, which occupy a considerable part of the cuticular epithelium surface. These abundant mitochondria are, most probably, the main element of heat production in the thermogenic center.     

Tunable Nanoparticle and Cell Assembly Using Combined Self‐Powered Microfluidics and Microcontact Printing

The combination of cell microenvironment control and real‐time monitoring of cell signaling events can provide key biological information. Through precise multipatterning of gold nanoparticles (GNPs) around cells, sensing and actuating elements can be introduced in the cells' microenviroment, providing a powerful substrate for cell studies. In this work, a combination of techniques are implemented to engineer complex substrates for cell studies. Alternating GNPs and bioactive areas are created with micrometer separation by means of a combination of vacumm soft‐lithography of GNPs and protein microcontract printing. Instead of conventional microfluidics that need syringe pumps to flow liquid in the microchannels, degas driven flow is used to fill dead‐end channels with GNP solutions, rendering the fabrication process straightforward and accessible. This new combined technique is called Printing and Vacuum lithography (PnV lithography). By using different GNPs with various organic coating ligands, different macroscale patterns are obtained, such as wires, supercrystals, and uniformly spread nanoparticle layers that can find different applications depending on the need of the user. The application of the system is tested to pattern a range of mammalian cell lines and obtain readouts on cell viability, cell morphology, and the presence of cell adhesive proteins.     

Odor active compounds content in spices and their microencapsulated powders measured by SPME

Within this study, main odorants of marjoram and thyme (linalool and thymol) were determined in spices and microencapsulated powders using solid-phase microextraction (SPME). Analyses were conducted on selected batches of spices before and after decontamination and on microencapsulated powders prepared for technological purposes (improvement of aroma in decontaminated spices). Conditions of SPME analyses were determined for individual compounds and matrices. Determination of total and surface contents of compounds and the percentage dependencies between encapsulated and surface aroma made it possible to identify the best powders in terms of their quality.     

Fabrication and characterization of magnetic cotton yarns for textile applications

Cotton yarns covered with hard (barium hexaferrite – BaFe), and soft (Black Toner 6745 CP-313) magnetic particles are investigated for their application in the field of functional textile. Our results reveal a rather consistent dependence of the magnetic yarn properties on the fabrication parameters (nature of the magnetic powder, composition of the coating solution, etc.). The magnetic properties (residual magnetism and coercive field intensity) of the yarns are increasing with the magnetic powder content in the coating solution. However, this is at some point leading to the degradation of some yarn properties, e.g. elasticity. Bending tests revealed that several factors improve the bending behavior of the yarns and reduce cracks. For example, a higher number of cracks were exhibited by the hard magnetic yarns compared to the soft ones. The presence of polyurethane in the coating solution leads to no cracks on the surface of hard magnetic yarns or a small number in case of soft magnetic yarns. The tensile properties of the magnetic yarns are increasing with increasing magnetic powder content. Over a certain mass percentage (45% for BaFe and 30% for CP-313), the magnetic yarns tensile strength and elongation become lower than those of the support yarn.