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.

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.

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.

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.

Different affinity of monoclonal antibodies for conserved neutralizing epitopes on two strains of rubella virus.

There is, apparently, only one serological type of rubella virus (RV) in the population, although several isolates exist with different characteristics. Some authors failed to detect significant differences among RV strains by neutralization, hemagglutination inhibition, and enzyme immunoassay using polyclonal and monoclonal antibodies, but differences in growth, plaque morphology, and temperature sensitivity between vaccine and wild-type strains were shown by Chantler et al. (3) With the purpose of analyzing the possible differences among several strains of RV, we studied the affinity constant of two monoclonal antibodies (MAbs) for two conserved neutralizing epitopes. Wild-type Cordoba (regional isolation of a post-natal infection) and RA 27/3 (vaccine) strains of RV were tested. H3 and H14 MAbs were generated against wild-type Cordoba strain. They defined two epitopes with conserved neutralizing and hemagglutinating activity on both strains. The affinity of the MAbs (expressed as the affinity constant), was greater for Cordoba strain than for RA 27/3. Analyzing the results obtained, we conclude that the neutralizing epitopes defined by our MAbs on E1 glycoprotein are conserved in the two strains, but react with significative different affinities. This could be a way to characterize antigenically different viral strains of the same serotype.

Acute effects of progesterone on glucose metabolism in rat adipocytes: are they modulated by endogenous adenosine?

Progesterone rapidly inhibits glucose oxidation of isolated rat adipocytes. Because this inhibition is triggered by endogenous adenosine, the present study was designed to examine the effect of the steroid on cyclic adenosine monophosphate (cAMP) accumulation, its relation to lipolysis, and the possible participation of adenosine. The results strongly indicate that physiological concentrations of progesterone increase the release of adenosine by isolated adipocytes, with maximal release at the end of a 20-minute incubation. Progesterone decreased both cAMP levels and lipolysis in quiescent adipocytes or in adipocytes stimulated by isoproterenol. The increase of endogenous adenosine may explain the decline of cAMP and glycerol levels observed with progesterone. The effects of the steroid on lipolysis disappeared when adenosine was hydrolyzed by adenosine deaminase (ADA). On the other hand, in the absence of endogenous adenosine, the effect of progesterone on the cAMP level was decreased only in isoproterenol-stimulated cells. The inhibitory effects of progesterone on cAMP and glycerol production seem not to be related directly to the adenosine A1 receptor, for selective A1 receptor antagonists (8-cyclopentyl-1,3-dipropylxanthine [DPCPX] and CP 68,247) did not counteract these effects. However, mechanisms mediated by guanyl nucleotide binding proteins cannot be excluded. The decrease of cAMP and of lipolysis may be related to a stimulation of phosphodiesterases (PDEs). When PDEs I [Ca(2+)-calmodulin-regulated PDE family) were blocked by a selective inhibitor (CP 41,757), the progesterone inhibitory effect persisted, suggesting that PDEs I are not regulated by the steroid. On the other hand, the progesterone effect on cAMP accumulation but not on lipolysis disappeared in the presence of a selective inhibitor of the PDE IV family (cAMP-dependent-specific family). Ro 20.1724. When the specific inhibitor of PDE I or PDE IV was combined with ADA, the progesterone effect on cAMP disappeared. Taken together, these results suggest that the progesterone inhibitory action on cAMP levels was not mediated through A1 receptors or through activation of PDE I, but may be related to PDE IV activities. The progesterone effect on lipolysis seemed not to be directly related to changes in cAMP levels; an effect on PDE III activities in relation with the increase of adenosine release cannot be excluded.

Kinetics of rubella-specific IgM antibody response in postnatal rubella infection.

The serological diagnosis of primary postnatal rubella infection is based on detection of rubella-virus-specific IgM antibody or a four-fold rise in rubella-specific IgG antibody. Although there are several different methods of enzyme immunoassays that are commercially available, the cost benefit evaluation makes them impractical for use in developing countries. For this reason, we have standardized the measurement of rubella IgM antibody by HAI following serum fractionation by ion-exchange chromatography. The sera samples obtained from pregnant women infected with rubella virus at different times during gestation were fractionated and tested by HAI. Seven out of nine sera collected within the first two days after onset of rash showed detectable levels of rubella IgM antibody. All 57 sera collected between 3 and 30 days after the onset of rash contained rubella IgM antibody. After 30 days, only 1 of 5, or 20%, of sera contained IgM antibody. The HAI testing method was rapid and specific and the cost was not prohibitive. HAI-IgM testing could be used to diagnose primary rubella infections in developing countries where expensive EIAs are unaffordable.

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.

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.

[Isolation of Chlamydia trachomatis and immune response in different populations]. / Aislamiento de Chlamydia trachomatis y respuesta inmune en diferentes poblaciones.

We studied the presence of C. trachomatis-specific IgG and IgM in adults and newborns, respectively, and attempted isolation of the bacteria in cell culture. The determination of antibodies was carried out by an IFA on C. trachomatis infected (L2 434/Bu serotype) McCoy cells, cultured in 24-well plastic plates. We found C. trachomatis-specific IgG in 27% of women with clinical symptoms, in 40% of women being attended for periodic gynecological control, in 60% of infertile women and in 10% of pregnant women. A proportion comparison test revealed the presence of specific IgG as highly significative for the group of infertile women as compared to the group of pregnant women (p < 0.0001). We divided the patients into four groups, in relation to the results of the tests for specific IgG and C. trachomatis isolation. Seven out of 10 had positive isolation and negative IFA, 5 out of 8 had positive isolation and negative IFA. Twenty five out of 28 pregnant women had negative isolation and positive IFA, finally, 63 out of 76 had both tests negative. Statistical analysis using the McNemar proportion-comparison test suggests that IgG's presence is highly significant in pregnant women with respect to other groups (p < 0.001). Our results suggest that the demonstration of IgG is not enough for diagnostic purposes, except in infertile women with a previous history of infection with C. trachomatis. We isolated C. trachomatis in 20% of the newborns tested and 10% were also positive for IgM IFA. The diagnosis was improved by combining both techniques. These results show the importance of the detection of C. trachomatis in youngsters to avoid infertility and in pregnant women to prevent newborn infections and the possibility of premature births and low weight babies.

[The biomass in upflow anaerobic filters]. / El contenido biológico de filtros anaeróbicos de flujo ascendente.

A cylindrical upflow filter packed with non-reticulated polyurethane foam, seeded with anaerobic sewage sludge and geared to biological treatment of dairy industrial wastewater, was used to determine the biomass content of the biofilm and suspended flora. This microflora is responsible for the conversion to methane and carbon dioxide of most of organic matter in wastewater. The methanogenic process reduces the COD of liquid wastes in more than 83% when operate at organic loading rate of 6 Kg COD/m3/d. Sequential sampling showed that biomass could be determined by measurement of volatile solids of each filter section. Those solids are related to filter geometry an produce accumulation of flocs (0.7g/l) in the bottom zone corresponding to liquid inlet.

[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.

[Detection of rubella antibodies in blood samples collected on filter paper]. / Detección de anticuerpos para rubéola en muestras de sangre recolectadas en papel de filtro.

Congenital rubella syndrome (CRS) could be prevented if young women knew their immune status before pregnancy, contributing in this way to decrease the birth morbidity rate due to CRS among the children. Our objective was to optimize the detection of rubella virus-antibodies by HAI, using an easier and safer method to collect samples of big populations. One hundred specimens, obtained from patients in a pediatric hospital and pregnant women in an institute of Virology were used for this work. Venous blood was drawn and collected in a test tube, and few drops were spotted onto filter paper circles. These samples were kept in envelopes and stored at room temperature until analysis. Seventy two percent of dried blood samples had titers identical to those of the corresponding serum samples, and 28% dried blood samples showed 1 dilution of difference. Storage of dried blood at room temperature for 30 days did not affect the HAI titers. Up to 60 days post attainment, 59% dried blood samples had identical titers to those of the corresponding serum samples, and 41% dried blood samples showed one dilution of difference. At 100 days of storage 51% dried blood samples had identical titers to those of the corresponding serum samples, 38% dried blood samples showed 1 dilution of difference and 11% and more than 1 dilution of difference. In conclusion, dried blood on filter paper is an easier method to transport and store blood samples for the determination of rubella virus immunity, for as long as 30 days. It could be used for large-scale epidemiological studies. The sensitivity and specificity of HAI performed on dried blood samples was 100%. Only 0.25 ml of whole blood is needed and the samples are stable at room temperature, without air or sterile conditioning. The proposed methodology is a practical approach to collect, transport and store blood samples. Moreover the blood dried on paper spots can be placed in a plastic bag and mailed to a reference laboratory. This is an appropriate alternative method for serological screenings in developing countries.

[Beta-galactosidase activity of strains of Kluyveromyces spp. and production of ethanol from lactose]. / Actividad de beta-galactosidasa de cepas de Kluyveromyces spp. y producción de etanol a partir de lactosa.

We investigated the behavior of yeast of the genus Kluyveromyces (K. fragilis 507, K. lactis 29 and K. lactis 10), which grow on lactose as sole carbon source, since they possess an enzyme system for the utilization of this sugar. We determined the beta-galactosidase activity of these strains, grown in the logarithmic phase in media containing glucose and lactose. On addition of 0 to 12% v/v ethanol to cells treated with toluene, we did not observe inhibition of the enzyme in strain 10 of Kluyveromyces lactis, which showed the greatest activity (704.4 Units). Since there exist the possibility of industrial utilization of concentrated whey (4 times), we performed fermentation tests of the three strains, at 30 C, in media containing initial lactose concentrations of 16.5 and 24.5%. After 48 h the residual lactose concentration was practically zero, and the ethanol concentrations had reached 7.60 and 10.10% v/v. It might be expected that the rate of fermentation of a disaccharide such as lactose would be related to the rate of hydrolysis of the sugar, so that strains having a higher rate of enzymatic hydrolysis should show a higher fermentation rate. However, we did not observe such behavior, as strains of Kluyveromyces having enzymatic activities as different as K. lactis 10 (704.4 U) and K. lactis 29 (189.7 U) did not show any great difference in the production of ethanol from lactose.

[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.

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.

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.