Characterizing the Chemical Profile of Incidental Ultrafine Particles for Toxicity Assessment Using an Aerosol Concentrator.

Incidental ultrafine particles (UFPs) constitute a key pollutant in industrial workplaces. However, characterizing their chemical properties for exposure and toxicity assessments still remains a challenge. In this work, the performance of an aerosol concentrator (Versatile Aerosol Concentration Enrichment System, VACES) was assessed to simultaneously sample UFPs on filter substrates (for chemical analysis) and as liquid suspensions (for toxicity assessment), in a high UFP concentration scenario. An industrial case study was selected where metal-containing UFPs were emitted during thermal spraying of ceramic coatings. Results evidenced the comparability of the VACES system with online monitors in terms of UFP particle mass (for concentrations up to 95 µg UFP/m3) and between filters and liquid suspensions, in terms of particle composition (for concentrations up to 1000 µg/m3). This supports the applicability of this tool for UFP collection in view of chemical and toxicological characterization for incidental UFPs. In the industrial setting evaluated, results showed that the spraying temperature was a driver of fractionation of metals between UF (<0.2 µm) and fine (0.2-2.5 µm) particles. Potentially health hazardous metals (Ni, Cr) were enriched in UFPs and depleted in the fine particle fraction. Metals vaporized at high temperatures and concentrated in the UF fraction through nucleation processes. Results evidenced the need to understand incidental particle formation mechanisms due to their direct implications on particle composition and, thus, exposure. It is advisable that personal exposure and subsequent risk assessments in occupational settings should include dedicated metrics to monitor UFPs (especially, incidental).

Animal welfare evaluation at slaughterhouses for pigs at the "Eje Cafetero" region in Colombia.

Within the insensitization by electronarcosis and the bleeding processes performed at the pig's slaughterhouses, there are some factors that hinder the achievement of an adequate slaughter of these animals, being this a critical phase in which animal welfare must be guaranteed; the objective of this study was to evaluate and compare the efficiency of insensitization by electronarcosis and two types of bleeding direction (horizontal and vertical). Dependent variables were measured as indicators of animal welfare (absence of the corneal reflex, absence of reflex of sensitivity to painful stimuli, attempts to reinstatement or posture recovery and vocalization), after the stunning and bleeding process, in four slaughterhouses of national category in "Eje Cafetero", Colombia. The methodological approach included the binomial distribution, descriptive statistics, hypothesis testing and statistical significance. The results show that the efficiency of the insensitization procedures and type of bleeding direction depends on multiple aspects, including the tranquility of the animals during their handling, the correct position of the insensitization clamps, the amperage used and the time between insensitization and bleeding. In this way, the analysis of possible preventive and/or corrective measures includes: Continuous training and supervision of the personnel in charge of carrying out the procedures, the need to immobilize pigs prior to their insensitization process, the continuous monitoring of process variables and the appropriate vascular cutting that ensures animal's death prior to their entrance into the scalding machine.

Fluctuations in measured radioactive decay rates inside a modified Faraday cage: Correlations with space weather.

For several years, reports have been published about fluctuations in measured radioactive decay time-series and in some instances linked to astrophysical as well as classical environmental influences. Anomalous behaviors of radioactive decay measurement and measurement of capacitance inside and outside a modified Faraday cage were documented by our group in previous work. In the present report, we present an in-depth analysis of our measurement with regard to possible correlations with space weather, i.e. the geomagnetic activity (GMA) and cosmic-ray activity (CRA). Our analysis revealed that the decay and capacitance time-series are statistically significantly correlated with GMA and CRA when specific conditions are met. The conditions are explained in detail and an outlook is given on how to further investigate this important finding. Our discovery is relevant for all researchers investigating radioactive decay measurements since they point out that the space weather condition during the measurement is relevant for partially explaining the observed variability.

On the Contact Geometry and the Poisson Geometry of the Ideal Gas.

We elaborate on existing notions of contact geometry and Poisson geometry as applied to the classical ideal gas. Specifically, we observe that it is possible to describe its dynamics using a 3-dimensional contact submanifold of the standard 5-dimensional contact manifold used in the literature. This reflects the fact that the internal energy of the ideal gas depends exclusively on its temperature. We also present a Poisson algebra of thermodynamic operators for a quantum-like description of the classical ideal gas. The central element of this Poisson algebra is proportional to Boltzmann's constant. A Hilbert space of states is identified and a system of wave equations governing the wavefunction is found. Expectation values for the operators representing pressure, volume and temperature are found to satisfy the classical equations of state.

On the van der Waals Gas, Contact Geometry and the Toda Chain.

A Toda-chain symmetry is shown to underlie the van der Waals gas and its close cousin, the ideal gas. Links to contact geometry are explored.

La caries dental y los factores relacionados en una población de adultos de la ciudad de la rioja, Argentina / The dental caries and related factors in adult population of the city of rioja, Argentina

La caries dental es un proceso patológico post-eruptivo, localizado, externo, involucra un reblandecimiento de los tejidos duros del diente procediendo a la formación de una cavidad1. Se determinó la presencia de caries dental, su relación con factores patológicos y preventivos en adultos de La Rioja, Argentina. A partir de 183 adultos de 25 a 35 años de edad se estudiaron los dientes con caries, obturaciones, perdidos e índice CPOD y se registraron en una ficha dental. Por cada adulto se obtuvo una historia clínica. El 77% de los adultos presentó un promedio de 3,73±4,28 caries, 4,75±4,61 obturaciones, 1,91±2,92 perdidos e índice CPOD 10,39±5,90. El CPOD para el género femenino fue mayor que para el masculino (p=0,042). La caries se relacionó con bajo nivel de educación (p=0,0001), ingreso económico (p=0,0086), cepillado dental diario (p=0,0340), cepillado nocturno (p=0,0018), con consulta prevalente por dolor (p<0,0001), falta de visita bucal anual (p=0,0003) y de obra social (p=0,0064). La caries dental es una enfermedad presente en la población adulta se asocia con bajo nivel de educación, económico y preventivo dental. Necesita del abordaje económico cultural integrado de la sociedad para mejorar la salud bucal del adulto y asegurar su calidad de vida en su senectud.

The dental caries is defined a post eruptive pathological process of external origin located tooth involves softening of the hard tissues of the tooth proceeding consequently to the formation of a tooth cavity1. The presence of dental caries was determined, its relationship with pathological and preventive factors in adults of La Rioja, Argentina. From 183 adults from 25-35 years of age, were studied decayed, fillings, missing teeth and index DMFT and recorded on a dental chart. For each adult, a clinic history was obtained. The 77% of adults had a mean of 3,73 ±4,28 caries, 4,75 ±4,61 filling, 1,91 ±2,92 missing and DMFT 10,39 ±5,90. The DMFT was higher for the female gender than for males (p=0,042). Caries was associated with low level of education (p=0,0001), low income (p=0,0086) lack tooth daily brushing (p<0,0340), lack of night brushing (p=0,018), check only for pain (p< 0,0001), lack of annual dental visit (p=0,0003) and absence of coverage social (p=0,0064). Dental caries is a disease present in the population of adults, is associated with low level education, economic and lack of prevention dental. Requires a socio cultural economic work of society to improve the oral health of adults and ensure their senescence.

Automation on the generation of genome-scale metabolic models.

Nowadays, the reconstruction of genome-scale metabolic models is a nonautomatized and interactive process based on decision making. This lengthy process usually requires a full year of one person's work in order to satisfactory collect, analyze, and validate the list of all metabolic reactions present in a specific organism. In order to write this list, one manually has to go through a huge amount of genomic, metabolomic, and physiological information. Currently, there is no optimal algorithm that allows one to automatically go through all this information and generate the models taking into account probabilistic criteria of unicity and completeness that a biologist would consider. This work presents the automation of a methodology for the reconstruction of genome-scale metabolic models for any organism. The methodology that follows is the automatized version of the steps implemented manually for the reconstruction of the genome-scale metabolic model of a photosynthetic organism, Synechocystis sp. PCC6803. The steps for the reconstruction are implemented in a computational platform (COPABI) that generates the models from the probabilistic algorithms that have been developed. For validation of the developed algorithm robustness, the metabolic models of several organisms generated by the platform have been studied together with published models that have been manually curated. Network properties of the models, like connectivity and average shortest mean path of the different models, have been compared and analyzed.

Reproductive Response of Ewes Fed with Taiwan Grass Hay (Pennisetum purpureum Schum.) Supplemented with Duckweed (Lemna sp. and Spirodela sp.).

The effect of duckweed (DW) supplementation was evaluated on dry matter intake (DMI), presence and duration of estrus, percentage of ewes repeating estrus and pregnancy rate, as well as the concentration of progesterone (P4) in multiparous crossbred ewes from Pelibuey, Dorper, and Katahdin breeds, fed with Taiwan grass hay (TWH). Eighteen ewes with 39.7±4 kg mean body weight, kept in individual pens, were randomly assigned to one of the following treatments: T1: TWH, T2: TWH plus 200 g DW, T3: TWH plus 300 g DW. The ewes were synchronized with 40 mg fluorogestone acetate (FGA) and 400 UI equine chorionic gonadotropin (eCG). Data were analyzed as a completely randomized design using the GLM procedure. DW supplementation had no effect on dry matter intake (p>0.05); however, a slight decrease of TWH intake was observed as DW supplementation increased. No differences (p>0.05) were found in the beginning of estrus, percentage of ewes presenting it, its duration, or pregnancy rate. There were no differences (p>0.05) on P4 concentration among treatments, or treatmentxperiod interaction (p>0.05). However the period was significant (p<0.01), since the P4 levels increased as time increased after the removal of the FGA device and eCG application.

Differential partitioning and speciation of Hg in wet FGD facilities of two Spanish PCC power plants.

This paper evaluates the speciation and partitioning of mercury in two Spanish pulverised coal combustion power plants (PP1 and PP2), equipped with wet limestone-based flue gas desulphurisation facilities (FGD) operating with forced oxidation and re-circulation of FGD water streams. These plants are fed with coal (PP1) and coal/pet-coke blends (PP2) with different mercury contents. The behaviour, partitioning and speciation of Hg were found to be similar during the combustion processes but different in the FGD systems of the two power plants. A high proportion (86-88%) of Hg escaped the electrostatic precipitator in gaseous form, Hg2+ being the predominant mercury species (68-86%) to enter the FGD. At this point, a relatively high total Hg retention (72% and 65%) was achieved in the PP1 and PP2 (2007) FGD facilities respectively. However, during the second sampling campaign for PP2 (2008), the mercury removal achieved by the FGD was much lower (26%). Lab-scale tests point to liquid/gas ratio as the main parameter affecting oxidised mercury capture in the scrubber. The partitioning of the gaseous mercury reaching the FGD system in the wastes and by-products differed. In the low mercury input power plant (PP1) most of the mercury (67%) was associated with the FGD gypsum. Moreover in PP2 a significant proportion of the gaseous mercury reaching the FGD system remained in the aqueous phase (45%) in the 2007 sampling campaign while most of it escaped in 2008 (74%). This may be attributed to the scrubber operating conditions and the different composition and chemistry of the scrubber solution probably due to the use of an additive.

Distribución espacial de Anopheles pseudopunctipennis en las Yungas de Salta, Argentina / Spatial distribution of Anopheles pseudopunctipennis in the Yungas de Salta rainforest, Argentina

OBJETIVO: Comparar la abundancia de Anopheles pseudopunctipennis, y otros anofelinos, en tres zonas silvestres y modificadas por el hombre, a fin de verificar en qué medida tales diferencias ambientales afectan la distribución espacial de estos mosquitos. MÉTODOS: Se realizaron muestreos mensuales (diciembre de 2001 a diciembre de 2002), con trampas de luz CDC con CO2, en cada sitio de muestreo (selva, borde de selva y peridomicilio). En el peridomicilio, además, dos operadores aspiraron mosquitos posados sobre las paredes. Se estimaron índices de diversidad y abundancia de especies, y se intentó caracterizar a los ambientes estudiados mediante ANOVA, cálculo de cosenos y análisis de agrupamientos. RESULTADOS: Anopheles pseudopunctipennis fue la especie más abundante. Se colectaron también An. argyritarsis, An. nuneztovari, An. rangeli y An. strodei. Excepto An. nuneztovari que no se capturó en el peridomicilio, las demás se colectaron en los tres ambientes. No hubo diferencias en los índices de diversidad, ni tampoco entre los ambientes estudiados; sin embargo, el análisis de agrupamiento separó el borde de la selva, donde todas las especies fueron más abundantes en general. CONCLUSIONES: El borde de la selva fue el ambiente que presentó la mayor abundancia, representando, además del peridomicilio, un ambiente de alto riesgo para la transmisión del paludismo.

Calculating rabies virus neutralizing antibodies titres by flow cytometry.

The determination of the rabies neutralizing antibody (VNA) response after immunization against rabies is an acceptable index of the efficacy of a vaccine and a successful treatment. Several tests have been developed in attempt to improve the assessment of VNA, from mice inoculation to cell-culture fluorescence inhibition tests. All of them, however, present special difficulties in terms of reading or accuracy. The present study describes a neutralization test performed in cell-culture appraised by flow cytometry (FC). Serial dilutions of the serum samples were mixed in vitro with rabies virus before the addition of BHK-21 cells. After 24h-incubation, cells were released by trypsin treatment, fixed and permeabilized with a p-formaldehyde solution and stained with a rabies virus nucleocapsid protein-specific antibody conjugate. The percentage of virus infection inhibition caused by specific antibodies present in the serum were evaluated in a Beckton Dickinson FACSCalibur flow cytometer. A correlation curve between the IU/ml content and the percentage of infective inhibition was built with a reference serum and the VNA titers of serum samples were obtained by extrapolation. Titers obtained by FC and standard test showed an effective pairing results (p < 0.01), with a correlation coefficient (r) = 0.7. These results permit to envisage the FC as a suitable technique to evaluate VNA in sera from immunized animals and likely in human serum samples. Nevertheless, new studies comparing FC to gold-standard techniques are required for determining the FC values of Sensibility and Specificity.

Investigación estadística en quirófano. Estudio sobre factores de riesgo en la formación de cataratas / Statistical research and investigation in surgery rooms. A study about risk factors in the formation of cataracts

Experiencia de investigación cuyo trabajo de campo se ha desarrollado en los quirófanos del Hospital Malva-Rosa (HMR, en Valencia). Su objetivo concreto es realizar un análisis estadístico de los diferentes factores que influyen en la formación de cataratas por envejecimiento, pero sobre todo, mostrar que la buena coordinación de un equipo quirúrgico permite integrar la investigación de enfermería en las tareas habituales del hospital.Para lograr dicho objetivo, hemos considerado una muestra de 500 pacientes intervenidos de cataratas por nuestro equipo en el hospital, empleando en todos los casos la misma técnica quirúrgica (facoemulsificación) y anestesia tópica. Con cada enfermo hemos cumplimentado en el antequirófano de cirugía oftalmológica una encuesta donde se recogen todos los parámetros a estudiar. Toda esta información se ha procesado en una base de datos que nos ha permitido relacionar la influencia de los diferentes factores en la formación de cataratas (edad, sexo, tabaquismo, diabetes, colesterol, hipertensión, etc.).Haremos hincapié en tres aspectos fundamentales del trabajo: describiremos la experiencia de enfermería, presentaremos algunas características básicas del programa informático desarrollado y mostraremos los resultados alcanzados para algunos de los parámetros analizados (AU)

[Statistical research in the operating room. Study on risk factors in cataract development]. / Investigación estadística en quirófano. Estudio sobre factores de riesgo en la formación de cataratas.

This investigation carried out its field work in the surgery rooms at the Malva-Rosa Hospital in Valencia. Its specific objective is the perform a statistical analysis of the various factors which bear an influence on the formation of cataracts due to aging, but moreover, to demonstrate that good coordination on a surgical team makes it possible to integrate research and investigation in nursing into the daily tasks of a hospital. In order to accomplish that goal, we have studied a sample of 500 patients who underwent cataract surgery by our team in this hospital, using the same surgical technique, phacoemulsification and topic anesthesia, in every case. For each patient, during the ophthalmologic pre-surgery procedures, we fill in a questionnaire in which we record all the parameters under study. All this data has been processed in a data base which allows us to correlate the influence of varying factors, such as age, sex, smoking, diabetes, cholesterol, or hypertension, in the formation of cataracts. We highlight three basic aspects in our study: we describe the nursing experience undergone, we present a few basic traits of the computer program developed, and we show the results obtained for some of the parameters analyzed.

Calculating rabies virus neutralizing antibodies titres by flow cytometry

The determination of the rabies neutralizing antibody (VNA) response after immunization against rabies is an acceptable index of the efficacy of a vaccine and a successful treatment. Several tests have been developed in attempt to improve the assessment of VNA, from mice inoculation to cell-culture fluorescence inhibition tests. All of them, however, present special difficulties in terms of reading or accuracy. The present study describes a neutralization test performed in cell-culture appraised by flow cytometry (FC). Serial dilutions of the serum samples were mixed in vitro with rabies virus before the addition of BHK-21 cells. After 24h-incubation, cells were released by trypsin treatment, fixed and permeabilized with a p-formaldehyde solution and stained with a rabies virus nucleocapsid protein-specific antibody conjugate. The percentage of virus infection inhibition caused by specific antibodies present in the serum were evaluated in a Beckton & Dickinson FACSCalibur® flow cytometer. A correlation curve between the IU/ml content and the percentage of infective inhibition was built with a reference serum and the VNA titers of serum samples were obtained by extrapolation. Titers obtained by FC and standard test showed an effective pairing results (p < 0.01), with a correlation coefficient (r) = 0.7. These results permit to envisage the FC as a suitable technique to evaluate VNA in sera from immunized animals and likely in human serum samples. Nevertheless, new studies comparing FC to gold-standard techniques are required for determining the FC values of Sensibility and Specificity

Fluidized bed design parameters affecting novel lactic Acid downstream processing.

Lactic acid purification was directly done from fermentation utilizing a fluidized bed column refilled with a strong anionic exchange resin. The purpose of this work was to study the influence of two important design parameters, bed-diameter (D) and bed-height (H), in the lactic acid binding and elution capacity of the matrix. By changing the settled bed height from 2.5 to 5 cm for each diameter of column analyzed it was possible to obtain an 50% increase in the binding capacity of the resin in all experiments. This fact was attributed to a higher contact time between the culture broth and the anionic resin produced by the increase of back mixing and lactic acid residence time.

Ansatz-independent solution of a soliton in a strong dispersion-management system

We introduce a theoretical approach to the study of propagation in systems with periodic strong-management dispersion. Our approach does not assume any ansatz about the form of the solution nor does it make use of any average procedure. We find an explicit solution for the pulse evolution in the fast dynamics regime (distances smaller than the dispersion period). We also establish the equation of motion governing the slow dynamics of an arbitrary pulse and prove that the pulse evolution is nonlinear and Hamiltonian. We solve this equation and find that a nonlinear solitonlike solution occurs self-consistently in the form of an asymptotic stationary eigenfunction of the Hamiltonian.

Evaluation of antibodies against a rubella virus neutralizing domain for determination of immune status.

The protective immune responses against rubella virus (RV) are related to its neutralizing epitopes, an issue that is important to consider when assessing the immune status of patients with remote infection. In the present paper, we compare the antibodies detected by a synthetic-peptide-based enzyme immunoassay (EIA) with antibodies detected by the traditional technique of hemagglutination inhibition (HIA) in patients with remote RV infection. The synthetic peptide used as an antigen (SP15) represents a neutralizing epitope that corresponds to amino acids 208 to 239 of the E1 glycoprotein. The SP15-EIA was developed, all variables that affected the assay were standardized, and the test was validated using reference sera. Serum samples (n = 129) from patients with remote RV infection were tested by HIA and SP15-EIA. Discrepant sera were assayed by MEIA (IMX/Abbot). The comparison between HIA and SP15-EIA, taking HIA as the standard methodology for determining immune status, showed that SP15-EIA is very specific and sensitive for detecting protecting antibodies (specificity, 100%; sensitivity, 98.20%). This study demonstrates that antibodies against the neutralizing domain represented by SP15 would be important in the memory response after natural infection and may be a good tool in the determination of the true immune status of patients with remote infection with regard to RV.

Neutralizing monoclonal antibody to the E1 glycoprotein epitope of rubella virus mediates virus arrest in VERO cells.

The best-known mechanism of action of antibody-mediated virus neutralization is to impede the entrance of viruses to host cells, as determined by neutralization assays. Antibodies may also inhibit the exit of rubella virus (RV) from infected host cells; in this case, the interaction of the antibodies with their domains must occur on the plasma membrane, because antibodies cannot enter the cells. In the present study, we were able to block temporally the exit of virions from RV-infected cells by the binding of monoclonal antibody (mAb) H3 to their surface. The objective was accomplished in three steps: first, we determined the duration of the viral replication cycle; then we established the kinetics of the presence of the domains defined by our mAbs in the cytoplasm of RV-infected VERO cells; and, finally, we assessed the release of viral particles to the supernatant of infected VERO cells in the presence or absence of mAbs or positive and negative mice sera. RV-specific mice sera and mAb H3, which binds to the amino acid sequence 208-239 of the RV-E1 glycoprotein, were able to delay for 24 hours the release of virions from infected cultures, suggesting that the reaction of mAb H3 with its epitope may arrest any change necessary for the assembly and/or release of virions. In conclusion, the neutralizing domain recognized by mAb induces antibodies that can block the viral replication by several mechanisms of action, such as the obstruction of virus entry into cells and the delay of viral release. All of these mechanisms are intimately involved in the critical virus-host cell interactions that allow self-limitation of the infection.

Continuous production of L(+)-lactic acid by Lactobacillus casei in two-stage systems.

A two-stage two-stream chemostat system and a two-stage two-stream immobilized upflow packed-bed reactor system were used for the study of lactic acid production by Lactobacillus casei subsp casei. A mixing ratio of D12/D2 = 0.5 (D = dilution rate) resulted in optimum production, making it possible to generate continuously a broth with high lactic acid concentration (48 g l-1) and with a lowered overall content of initial yeast extract (5 g l-1), half the concentration supplied in the one-step process. In the two-stage chemostat system, with the first stage at pH 5.5 and 37 degrees C and a second stage at pH 6.0, a temperature change from 40 degrees C to 45 degrees C in the second stage resulted in a 100% substrate consumption at an overall dilution rate of 0.05 h-1. To increase the cell mass in the system, an adhesive strain of L. casei was used to inoculate two packed-bed reactors, which operated with two mixed feedstock streams at the optimal conditions found above. Lactic acid fermentation started after a lag period of cell growth over foam glass particles. No significant amount of free cells, compared with those adhering to the glass foam, was observed during continuous lactic acid production. The extreme values, 57.5 g l-1 for lactic acid concentration and 9.72 g l-1 h-1 for the volumetric productivity, in upflow packed-bed reactors were higher than those obtained for free cells (48 g l-1 and 2.42 g l-1 h-1) respectively and the highest overall L(+)-lactic acid purity (96.8%) was obtained in the two-chemostat system as compared with the immobilized-cell reactors (93%).

[Presence of Mycoplasma in laboratory cell cultures from Cordoba, Argentina]. / Presencia de micoplasmas en cultivos celulares en laboratorios de la ciudad de Córdoba, Argentina.

In this paper we determined the prevalence of mycoplasma contamination in 17 cell lines. Eighty per cent of the laboratories that currently use cell culture techniques participated in this study. Hoechst 33258 dye was used to detect mycoplasma contamination. The relationship between culture maintenance conditions and the presence of mycoplasma were analyzed, considering the use of antibiotics in the culture media, fetal calf serum (FCS) quality, culture media processing, use of disponsable labware, type of laminar flow cabinet, quantity of operators, and cell culture system. Thirty-five per cent of the analyzed cell lines showed mycoplasma contamination. Those lines belonged to 2 of the 8 surveyed laboratories. When confronting the working conditions versus mycoplasma contamination, 66% of the laboratories that employ non-certified FCS or reuse their labware, show mycoplasma contamination. Mycoplasma presence was found in 50% of the laboratories that use closed culture system, or more than one operator. Laboratories that process their culture media or that include antibiotic in the growing media, show a 40% contamination. The results obtained help to establish working conditions necessary to avoid introducing or spreading the microorganism.