DNA detection using a triple readout optical/AFM/MALDI planar microwell plastic chip

A ready-to-spot disposable DNA chip for specific and sensitive detection of DNA was developed. Plastic copolymeric substrate chemistry was optimized to selectively couple the target DNA with the active chip surface. At the same time, the developed substrate limits the unspecific adsorption of probe DNA molecules or additional polar contaminants in the test samples to the chip surface. The combination of glycidyl and n-butyl methacrylates was found to best fit the requirements of the assay. The fabricated DNA microarrays have mechanical properties similar to those of the glass or silicon substrates and, at the same time, provide chemically reactive surfaces that do not require lengthy chemical modification. An additional advantage of the plastic microchip is its compatibility with different analytical readout techniques, such as mass spectrometry (MALDI-TOF/MS), optical detection (fluorescence and enzyme-induced metal deposition), and imaging techniques (atomic force microscopy). These multiple readout techniques have given us the ability to compare the sensitivity, selectivity, and robustness of current state-of-the-art bioanalytical methods on the same platform exemplified by successful DNA-based detection of human cytomegalovirus. The obtained sensitivity for enzymatically enhanced silver deposition (10(-15) M) surpasses that of conventional fluorescence readouts. In addition, the assay's dynamic range (10(-6)-10(-15) M), reproducibility, and reliability of the DNA probe detection speaks for the silver deposition method. At compromised sensitivity (10(-9) M), the length of the DNA probes could be checked and, alternatively, DNA single point polymorphisms could be analyzed.     

Biological dosimetry and Bayesian analysis of chromosomal damage in thyroid cancer patients

Chromosomal damage was investigated in lymphocytes of thyroid cancer patients after radioiodine treatment. An assay on micronuclei (MN) in binucleated cells was performed in blood samples of 25 patients 3 d after (131)I (3.7 GBq) was given. Statistical analysis does not show overdispersion of the MN distribution, thus considering the exposure to blood as being homogeneous (p < 0.05). A dose-protraction factor (G) of 0.1 was considered into the calculation of the blood dose to take into account the effect of the duration of exposure. The total MN count is a sum of the background distribution and the Poisson distribution induced by radiation exposure. A Bayesian approach was used to avoid inconsistencies when the total count was close to or lower than the background level. Estimated blood dose after 3 d of exposure was 0.73 Gy (0.197 mGy/MBq). The usefulness of the Bayesian method in analysing chromosomal damage when the count is low has been determined.     

Irreversible effects of random unitary transformations on coherence properties of partially polarized electromagnetic fields

We demonstrate monotonic, irreversible effects on the entropy, the degree of polarization, and different degrees of coherence when random, energy-preserving unitary transformations are applied to vectorial electromagnetic fields.     

SAPHIR: a physiome core model of body fluid homeostasis and blood pressure regulation

We present the current state of the development of the SAPHIR project (a Systems Approach for PHysiological Integration of Renal, cardiac and respiratory function). The aim is to provide an open-source multi-resolution modelling environment that will permit, at a practical level, a plug-and-play construction of integrated systems models using lumped-parameter components at the organ/tissue level while also allowing focus on cellular- or molecular-level detailed sub-models embedded in the larger core model. Thus, an in silico exploration of gene-to-organ-to-organism scenarios will be possible, while keeping computation time manageable. As a first prototype implementation in this environment, we describe a core model of human physiology targeting the short- and long-term regulation of blood pressure, body fluids and homeostasis of the major solutes. In tandem with the development of the core models, the project involves database implementation and ontology development.     

Integrated environmental assessment of Volturno River in South Italy

The application of a battery of toxicity and genotoxicity tests on pore water in parallel and in combination with physico-chemical analyses and benthic macroinvertebrate community investigations is discussed as a tool to assess the environmental quality of the Volturno River in South Italy. Toxicity testing was performed on the rotifer Brachionus calyciflorus and the crustacean Daphnia magna. Genotoxicity was determined by the SOS chromotest and Mutatox system. The biotic index used for macroinvertebrates was the extended biotic index that was developed to verify if the observed benthic community accords with the expected one for an identical environment without anthropic contaminations. The physico-chemical characterization of the surface waters showed a declining trend from up-river to down-river for dissolved oxygen and conductivity. Also, chemical variables showed a worsening along the river axis showing an increase in ammonium, phosphates, sulfates, and heavy metals. The assessment of macro-invertebrates reflected the general ecological deterioration occurring to chemical as well as toxic and genotoxic pollution. Furthermore, benthic community composition and the sediment contamination of toxic and genotoxic substances were shown to be correlated. We concluded that investigations on pore water, integrated with benthic macroinvertebrate communities, could provide the basis for a robust monitoring of rivers.     

Infection risk assessment of diarrhea-related pathogens in a tropical canal network

A quantitative microbial risk assessment (QMRA) of Cryptosporidium, Giardia and diarrhegenic Escherichia coli (DEC) infection was performed using Monte Carlo simulations to estimate the human health risks associated with the use of canal water for recreational purposes, unrestricted and restricted irrigation in a tropical peri-urban area. Three canals receiving municipal, agricultural, and, predominantly, industrial wastewater were investigated. Identification of pathogenic protozoans revealed the major presence of Cryptosporidium hominis and both assemblages A and B of Giardia lamblia. The highest individual infection risk estimate was found to be for Giardia in an exposure scenario involving the accidental ingestion of water when swimming during the rainy season, particularly in the most polluted section, downstream of a large wholesale market. The estimated annual risks of diarrheal disease due to infection by the protozoan parasites were up to 120-fold greater than the reported disease incidence in the vicinity of the studied district and the entire Thailand, suggesting a significant host resistance to disease beyond our model's assumptions. In contrast, annual disease risk estimates for DEC were in agreement with actual cases of diarrhea in the study area.     

The Cerro Prieto IV (Mexico) geothermal reservoir: Pre-exploitation thermodynamic conditions and main processes related to exploitation (2000–2005)

The Cerro Prieto IV (CP IV) reservoir, located in the northeastern part of the Cerro Prieto (Mexico) geothermal field, was studied in order to define its pre-exploitation conditions and initial (2000–2005) response to exploitation. Bottomhole thermodynamic conditions were estimated by modeling heat and fluid flows using the WELLSIM program and well production data. Produced fluid chemical and isotopic data were also analyzed to investigate characteristic patterns of behavior over time, which were then compared against simulation results to obtain a conceptual model of the CP IV reservoir. According to the proposed model, two zones in the reservoir – separated by Fault H and producing fluids of different characteristics – were identified under pre-exploitation conditions. Wells in the area to the east-southeast (south block) produce very high-enthalpy fluids (≥2000 kJ/kg), with very low chloride (≤7000 mg/kg) and high CO₂ (>6‰ molar) and δD (<−94‰). In contrast, wells toward the west-northwest (north block) show moderate-enthalpy fluids (1400–1800 kJ/kg), with high chloride (∼12,000 mg/kg) and relatively low CO₂ (<6‰ molar) and δD (<−94‰). Dilution caused by cooler water entry, boiling due to steam gain, both occurring in the north block, and steam condensation in the south block were identified as the three main reservoir processes associated with exploitation. Also, it was found that the dynamics of the CP IV reservoir is controlled by the Fault H system.     

Thermal inactivation of <Emphasis Type="Italic">Alicyclobacillus acidoterrestris</Emphasis> spores under conditions simulating industrial heating processes of tangerine vesicles and its use in time temperature integrators

The aim of the present study was to characterize the thermal inactivation of Alicyclobacillus acidoterrestris spores under isothermal and non-isothermal conditions simulating industrial heating processes applied to tangerine vesicles. A microbiological time temperature integrator (TTI) suitable for estimating the severity of thermal processes applied to acid foods was also developed. The heat resistance of A. acidoterrestris was characterized by D _105 °C = 0.63 min and z = 10.8 °C in tangerine juice, showing linear survival curves, without shoulders and tails. Under non-isothermal conditions, the use of isothermal data allowed for an accurate prediction of the inactivation. The spores were included in alginate TTIs and they were used to estimate the severity of thermal treatments applied both in a thermoresistometer Mastia and in a food pilot plant scale system, which allows fast heating of the product to 93 °C and then a short holding time (2 min). In the thermoresistometer, tangerine juice was used as heating medium. In the food pilot plant scale system, thermal treatments were applied in batch to unpackaged tangerine vesicles. In both equipments, the TTIs accurately predicted the lethality of the thermal treatments applied. The percent coefficients of variation for survivor counting in TTIs showed that distribution of heat is homogeneous both in the thermoresistometer and in the reactor, being lower than 10% in all cases. The logistic and normal distributions were found to be the best for fitting the different survivor datasets.     

Vision Based Tracking for a Quadrotor Using Vanishing Points

In this paper, a vision based line tracking control strategy for mini-rotorcraft is presented. In order to estimate the 3-D position of the mini-rotorcraft over the trajectory a vanishing points technique is used. A dynamic model is derived employing the Newton–Euler approach and a nonlinear controller to stabilize, in closed-loop system, this mathematical model is proposed. To validate the theoretical results, a real-time embedded control system has been developed. The performance of the vision and control algorithms has been tested when the helicopter has tracked a line painted in a wall. The experimental results have shown the good behavior of the control laws.