1,501 research outputs found
Bosonic String and String Field Theory: a solution using Ultradistributions of Exponential Type
In this paper we show that Ultradistributions of Exponential Type (UET) are
appropriate for the description in a consistent way string and string field
theories. A new Lagrangian for the closed string is obtained and shown to be
equivalent to Nambu-Goto's Lagrangian. We also show that the string field is a
linear superposition of UET of compact support CUET). We evaluate the
propagator for the string field, and calculate the convolution of two of them.Comment: 30 page
A novel locus for autosomal recessive primary microcephaly (MCPH6) maps to 13q12.2
Key points:
• Autosomal recessive primary microcephaly (MCPH) is a
genetic disorder in which an affected subject is born
with a head circumference >3 SD below the expected
mean and is mentally retarded.
• We report a novel locus (MCPH6) mapped to chromosome
13q12.2 in a Brazilian family.
• The minimal critical region spans 6 Mb between markers
AL139378GT17 and D13S1244 with a maximum
two point lod score of 6.25
Cell spotting – let’s fight cancer together!
Efficient cancer drugs need to selectively destroy tumour cells without harming healthy cells. Existing chemotherapy treatments have failed to reach that ideal level of selectivity, but many research teams continue to look for compounds that could become the effective and side-effect-free drugs of tomorrow..
Heterogeneous catalysis for the synthesis of carbon dots (CDs) from biomass source
It has been evaluated the capacity of several phosphate-based acid catalysts of transition metals such as vanadium and niobium in the synthesis of carbon dots (CDs) via a hydrothermal process. For this purpose, two sources of carbohydrates have been used: commercial xylose and liqueur of xylose obtained from the treatment of olive pits. Catalysts were characterized by means of NH3-TPD, DTA/TG, XRD and XPS. The reaction was carried out at 180 °C and reaction time was varied between 2 and 4h. The properties and characteristics of CDs nanoparticles were analysed confirming the existence of such nanoparticles irrespective the carbohydrate source. In terms of CDs quality, both syntheses produced comparable results. At the same time, N doped CDs with enhanced fluorescence were also synthesized following a kindred hydrothermal process and the photocatalytic activity was studied. With the aim of evaluating the environmental impact of the synthesis from commercial xylose versus the synthesis from biomass, a Life Cycle Assessment (LCA) analysis was carried out for both syntheses. It showed that the most sustainable synthesis route is the one that uses commercial xylose as carbonaceous feedstock. Furthermore, while electricity is the main contributor to all impact categories in both synthesis routes, the main differences that determine their relative sustainability are associated with the identity of the carbon precursor.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Reduced Fluoresceinamine as a Fluorescent Sensor for Nitric Oxide
A new fluorescent sensor for nitric oxide (NO) is presented that is based on its reaction with a non fluorescent substance, reduced fluoresceinamine, producing the highly fluorescent fluoresceinamine. Using a portable homemade stabilized light source consisting of 450 nm LED and fiber optics to guide the light, the sensor responds linearly within seconds in the NO concentration range between about 10–750 μM with a limit of detection (LOD) of about 1 μM. The system generated precise intensity readings, with a relative standard deviation of less than 1%. The suitability of the sensor was assessed by monitoring the NO generated by either the nitrous acid decomposition reaction or from a NO-releasing compound. Using relatively high incubation times, the sensor also responds quantitatively to hydrogen peroxide and potassium superoxide, however, using transient signal measurements results in no interfering species
Zero Energy of Plane-Waves for ELKOs
We consider the ELKO field in interaction through contorsion with its own
spin density, and we investigate the form of the consequent autointeractions;
to do so we take into account the high-density limit and find plane wave
solutions: such plane waves give rise to contorsional autointeractions for
which the Ricci metric curvature vanishes and therefore the energy density is
equal to zero identically. Consequences are discussed.Comment: 7 page
Factorial analysis of the trihalomethanes formation in water disinfection using chlorine
The factors that affect trihalomethane (THM) (chloroform, bromodichloromethane, chlorodibromomethane and bromoform) formation from
the chlorination of aqueous solutions of hydrophobic fulvic acids (FA) were investigated in a prototype laboratorial simulation using factorial
analysis. This strategy involved a fractional factorial design (16 plus 5 center experiments) of five factors (fulvic acids concentration, chlorine dose,
temperature, pH and bromide concentration) and a Box Behnken design (12 plus 3 center experiments) for the detailed analysis of three factors (FA
concentration, chlorine dose and temperature). The concentration ofTHMwas determined by headspace analysis by GC–ECD. The most significant
factors that affect the four THM productions were the following: chloroform—FA concentration and temperature; bromodichloromethane—FA
concentration and chlorine dose; chlorodibromomethane—chlorine dose; and, bromoform—chlorine dose and bromide concentration. Moreover,
linear models were obtained for the four THM concentrations in the disinfection solution as function of the FA concentration, chlorine dose and
temperature, and it was observed that the complexity of the models (number of significant factors and interactions) increased with increasing
bromine atoms in the THM. Also, this study shows that reducing the FA concentration the relative amount of bromated THM increases
Galaxy evolution in the infrared : comparison of a hierarchical galaxy formation model with Spitzer data
We present predictions for the evolution of the galaxy luminosity function, number counts and redshift distributions in the infrared (IR) based on the ΛCDM cosmological model. We use the combined GALFORM semi-analytical galaxy formation model and GRASIL spectrophotometric code to compute galaxy spectral energy distributions including the reprocessing of radiation by dust. The model, which is the same as that given by Baugh et al., assumes two different initial mass functions (IMFs): a normal solar neighbourhood IMF for quiescent star formation in discs, and a very top-heavy IMF in starbursts triggered by galaxy mergers. We have shown previously that the top-heavy IMF seems to be necessary to explain the number counts of faint submillimetre galaxies. We compare the model with observational data from the Spitzer Space Telescope, with the model parameters fixed at values chosen before Spitzer data became available. We find that the model matches the observed evolution in the IR remarkably well over the whole range of wavelengths probed by Spitzer. In particular, the Spitzer data show that there is strong evolution in the mid-IR galaxy luminosity function over the redshift range z∼ 0–2, and this is reproduced by our model without requiring any adjustment of parameters. On the other hand, a model with a normal IMF in starbursts predicts far too little evolution in the mid-IR luminosity function, and is therefore excluded
Conjugated linoleic acid production and probiotic assessment of Lactobacillus plantarum isolated from Pico cheese
peer-reviewedLactic acid bacteria isolated from a traditional Azorean cheese were screened for their ability to convert free linoleic acid to conjugated linoleic acid (CLA). Two strains of Lactobacillus plantarum were recognized as potential CLA producers. GC analysis identified cis-9, trans-11 C18:2 as the predominant isomer (10–14 μg/mL), followed by trans-9, trans-11 C18:2 (4–6 μg/mL). The CLA producing strains demonstrated strong biofilm capacity, high cell surface hydrophobicity and good auto-aggregation ability. These strains were capable of surviving in the presence of bile salts (0.3%) and pancreatin (0.1%), but only the highest CLA producer (L3C1E8) was able to resist low pH (2.5). Moreover, the CLA-producers showed good adhesion capacity to intestinal human cells (Caco-2 and HT-29) and were able to prevent colonization of Escherichia coli. Of the two strains, Lactobacillus plantarum L3C1E8 revealed superior probiotic properties and great potential for producing food products enriched in the two CLA isomers, cis-9, trans-11 C18:2 (60%) and trans-9, trans-11 C18:2 (25%)
Periods Of Weed Interference In Maize Crops Cultivated In The First And Second Cycles
The interference of weeds in maize production may be reflected in grain yield losses that vary as a function of the density, stage and degree of aggressiveness of the species present. In the agricultural ecosystem, crops and weeds demand light, water, nutrients and space, which are frequently not available in sufficient quantities, leading to competition. The aim of this work was to determine the period of interference of weed plants, in particular of naked crabgrass (Digitaria nuda) on maize crop in the first and second harvest. The treatments were defined as increasing periods of coexistence and increasing control of weed community (7, 14, 21, 28, 35, 42, 49, and 56 days), two more controls, a control including one with weed control until the end of the culture cycle and another with coexistence until the harvest. For each period, were evaluated the stand of maize plants, length of ear, number of grains per row, number of rows per ear, cob, 100-grain weight, and grain productivity. The data obtained were subjected to analysis of variance using the F test, with average treatments compared using Tukey's test at 5% probability. Crop productivity was evaluated by means of regressions, the critical periods of interference were estimated. The critical timing of weed removal was 25 days for both harvests. The critical weed free period was 54 and 27 days for the first and second harvest respectively. For the conditions of the first and second harvest, the critical period of weed control was of 29 and 2 days respectively.3752867287
- …