Human-induced metals accumulation in sediments of an industrialized bay of northern Chile. An enrichment and ecological risk assessment based on preindustrial values.

Environmental assessment in marine systems is difficult because most of the time their preindustrial characteristics are not available. Four sediment cores taken in Mejillones bay (northern Chile) were used to establish preindustrial metals concentrations, and to assess the environmental status of this industrialized zone. According to historical documents, the beginning of the industrial era start in 1850 CE. Considering this, the preindustrial concentration of some metals was established, by mean of a statistical approach. Most of the metals increase their concentration from the preindustrial to the industrial period. Environmental assessment showed an enrichment of Zr and Cr, a moderately polluted condition, and a low probability of toxic effect on the biological communities. The preindustrial values derived from sediment cores are a good tool to evaluate the environmental condition of Mejillones bay. However new information (backgrounds with a higher spatial representativity, toxicological threshold, and others) it is necessary to improve the environmental assessment of this environment.

The persistence of financial volatility after COVID-19.

This paper analyzes the long-term effects of COVID-19 on financial volatility. We estimate the long memory parameters before and after COVID-19 for the VIX and realized variances for several international markets. Our results show that volatility measures for most countries experienced increases in the degrees of memory following the pandemic. Moreover, several volatility measures became nonstationary, signaling the start of a period with higher and more persistent financial volatility. We show that these changes in the degrees of memory are statistically significant using a test for change in persistence.

Dataset on thermal comfort, perceived stress, and anxiety in university students under confinement due to COVID-19 in a hot and humid region of Mexico.

This dataset was compiled to estimate the levels of thermal comfort and mental health in a sample group of university students confined due to the COVID-19 pandemic. By the time research was carried out, these students of a hot and humid region of Mexico, had already spent 200 days on distance learning using online platforms. A total of 324 records were documented with a final sample of 316 valid participants. The total records were collected directly from the students through a web platform (Microsoft forms). This data set can be used to generate correlations between mental health, thermal comfort, and individual characteristics in the study population that will allow to identify the influence of the built environment and local climate on the levels of stress and anxiety that university students experienced under confinement. It can also be used to issue recommendations to improve the quality of built spaces and for the construction of adaptive models of thermal comfort considering mental health as a study variable.

A genome-wide association study identifies novel gene associations with facial skin wrinkling and mole count in Latin Americans.

BACKGROUND: Genome-wide association studies (GWASs) have identified genes influencing skin ageing and mole count in Europeans, but little is known about the relevance of these (or other genes) in non-Europeans. OBJECTIVES: To conduct a GWAS for facial skin ageing and mole count in adults < 40 years old, of mixed European, Native American and African ancestry, recruited in Latin America. METHODS: Skin ageing and mole count scores were obtained from facial photographs of over 6000 individuals. After quality control checks, three wrinkling traits and mole count were retained for genetic analyses. DNA samples were genotyped with Illumina's HumanOmniExpress chip. Association testing was performed on around 8 703 729 single-nucleotide polymorphisms (SNPs) across the autosomal genome. RESULTS: Genome-wide significant association was observed at four genome regions: two were associated with wrinkling (in 1p13·3 and 21q21·2), one with mole count (in 1q32·3) and one with both wrinkling and mole count (in 5p13·2). Associated SNPs in 5p13·2 and in 1p13·3 are intronic within SLC45A2 and VAV3, respectively, while SNPs in 1q32·3 are near the SLC30A1 gene, and those in 21q21·2 occur in a gene desert. Analyses of SNPs in IRF4 and MC1R are consistent with a role of these genes in skin ageing. CONCLUSIONS: We replicate the association of wrinkling with variants in SLC45A2, IRF4 and MC1R reported in Europeans. We identify VAV3 and SLC30A1 as two novel candidate genes impacting on wrinkling and mole count, respectively. We provide the first evidence that SLC45A2 influences mole count, in addition to variants in this gene affecting melanoma risk in Europeans.

Regional Alterations in Cortical Sulcal Depth in Living Fetuses with Down Syndrome.

Down syndrome (DS) is the most common genetic cause of developmental disabilities. Advanced analysis of brain magnetic resonance imaging (MRI) has been used to find brain abnormalities and their relationship to neurocognitive impairments in children and adolescents with DS. Because genetic factors affect brain development in early fetal life, there is a growing interest in analyzing brains from living fetuses with DS. In this study, we investigated regional sulcal folding depth as well as global cortical gyrification from fetal brain MRIs. Nine fetuses with DS (29.1 ± 4.24 gestational weeks [mean ± standard deviation]) were compared with 17 typically developing [TD] fetuses (28.4 ± 3.44). Fetuses with DS showed lower whole-brain average sulcal depths and gyrification index than TD fetuses. Significant decreases in sulcal depth were found in bilateral Sylvian fissures and right central and parieto-occipital sulci. On the other hand, significantly increased sulcal depth was shown in the left superior temporal sulcus, which is related to atypical hemispheric asymmetry of cortical folding. Moreover, these group differences increased as gestation progressed. This study demonstrates that regional sulcal depth is a sensitive marker for detecting alterations of cortical development in DS during fetal life, which may be associated with later neurocognitive impairment.

Multiwavelength analysis of the variability of the blazar 3C 273.

We present multiwavelength light curves and polarimetric data of the Flat Spectrum Radio Quasar 3C 273 over 8 yr. The wavelength range of our data set extends from radio to gamma-rays. We found that the optical emission in this source is dominated by the accretion disc during the entire time-frame of study. We additionally find that in contrast with the observed behaviour in other blazars, 3C 273 does not show a correlation between the gamma-ray spectral index and the gamma-ray luminosity. Finally, we identified an anticorrelation between the 15 GHz and V-band light curves for the time-range JD 245 = 4860-5760, which we speculate is the consequence of the inner part of the accretion disc falling into the black hole, followed by the ejection of a component into the jet.

Irreversible multilayer adsorption of semirigid k-mers deposited on one-dimensional lattices.

Irreversible multilayer adsorption of semirigid k-mers on one-dimensional lattices of size L is studied by numerical simulations complemented by exhaustive enumeration of configurations for small lattices. The deposition process is modeled by using a random sequential adsorption algorithm, generalized to the case of multilayer adsorption. The paper concentrates on measuring the jamming coverage for different values of k-mer size and number of layers n. The bilayer problem (n≤2) is exhaustively analyzed, and the resulting tendencies are validated by the exact enumeration techniques. Then, the study is extended to an increasing number of layers, which is one of the noteworthy parts of this work. The obtained results allow the following: (i) to characterize the structure of the adsorbed phase for the multilayer problem. As n increases, the (1+1)-dimensional adsorbed phase tends to be a "partial wall" consisting of "towers" (or columns) of width k, separated by valleys of empty sites. The length of these valleys diminishes with increasing k; (ii) to establish that this is an in-registry adsorption process, where each incoming k-mer is likely to be adsorbed exactly onto an already adsorbed one. With respect to percolation, our calculations show that the percolation probability vanishes as L increases, being zero in the limit L→∞. Finally, the value of the jamming critical exponent ν_{j} is reported here for multilayer adsorption: ν_{j} remains close to 2 regardless of the considered values of k and n. This finding is discussed in terms of the lattice dimensionality.

NaStEP, an essential protein for self-incompatibility in Nicotiana, performs a dual activity as a proteinase inhibitor and as a voltage-dependent channel blocker.

The S-specific pollen rejection response in Nicotiana depends on the interaction between S-RNase and a suite of SLF proteins. However, the biochemical pathway requires other essential proteins. One of them is the stigmatic protein NaStEP, which belongs to the Kunitz-type protease inhibitor family. Within the pollen tubes, NaStEP is a positive regulator of HT-B stability, likely inhibiting its degradation and, additionally, interacts with NaSIPP, a mitochondrial phosphate carrier. To gain a deeper understanding of the biochemical role of NaStEP in pollen rejection, we evaluated whether the activity of NaStEP as protease inhibitor is specific to a particular type of protease and whether it has the function of a voltage-dependent channel (VDC) blocker. Our findings indicate that, in vitro, NaStEP inhibits a subtilisin-like protease in an irreversible manner, but not other proteases, such as thermolysin and papain. Furthermore, we found that subtilisin processes the native NaStEP (24 kDa) into two lower molecular weight peptides of 21 and 14 kDa. Moreover, when we incubated NaStEP along with Xenopus leavis oocytes expressing the voltage-dependent potassium channel Kv 1.3, the current was blocked, indicating that NaStEP acts as a VDC blocker. These data allow us to propose NaStEP acts as a key molecule with two functions, one protecting HT-B from degradation by inhibiting a subtilisin-like protease and the second one by forming a complex with a mitochondrial VDC that could destabilize the mitochondria to trigger cell death, which would reinforce S-specific pollen rejection in Nicotiana.

Use of coffee pulp and sorghum mixtures in the production of n-demethylases by solid-state fermentation.

One of the compounds generally found in the residues of the coffee and tea industries is caffeine, which in high concentration is toxic to various organisms, making it necessary to find an adequate treatment for these residues. Biotechnological treatments using enzymes can be an alternative to valorize and detoxify these residues. However, mixtures of substrates have not been evaluated to improve production. Therefore, the present investigation aimed to study the effect of different proportions of sorghum-coffee pulp mixtures as a substrate in solid-state fermentation with the fungus Rhizopus oryzae (MUCL 28168) for the production of n-demethylases. To evaluate the synergistic and antagonistic effects of coffee pulp and sorghum mixtures on n-demethylase enzyme production, a simplex-centroid design, using four levels: 1 (100%), 1/4 (25%), 1/2 (50%), 3/4 (75%). Results obtained were favorable, achieving a caffeine demethylase activity of 18.762 U/g, and reducing the caffeine content in the coffee pulp.

Enzymatic Biotransformation of Pomegranate Ellagitannins: Initial Approach to Reaction Conditions.

BACKGROUND: Ellagitannase (Ellagitannin acyl hydrolase) is an inducible enzyme with great potential use in food industry since allows the ellagic acid release from ellagitannins. OBJECTIVE: In this work, ellagitannase was produced by the fungus Aspergillus niger GH1 in solid state fermentation using polyurethane foam as solid support and pomegranate husk ellagitannins as sole carbon source and ellagitannase inducer and an initial approach to the enzymatic reaction conditions was reached. MATERIALS AND METHODS: Ellagitannase was produced by Aspergillus niger GH1 in solid state fermentation and the ideal reaction conditions for ellagitannase activity based on ellagic acid quantification as ellagitannins biotransformation product by high performance liquid chromatographic are reported. RESULTS: The enzyme ideal reaction conditions were substrate concentration of 1 mg.mL-1, 60 °C and pH 5.0, during 10 min of reaction. The kinetic enzyme constants (V max = 30.34 mM.mL-1.min-1 and K m = 1.48 x 103 mM) using punicalagin assubstrate were determined. CONCLUSION: The assay was completed in a short time and may find application in future studies of ellagic acid production.

[Effect of transcraneal magnetic stimulation on the motor recovery of the thoracic limb in cerebrovascular disease -a systematic review]. / Efecto de la estimulacion magnetica transcraneal sobre la recuperacion motora del miembro toracico en la enfermedad vascular cerebral. Revision sistematica.

INTRODUCTION: There have been studies in which contralesional inhibitory and ipsilesional excitatory transcranial magnetic stimulation (TMS) has been used as coadjuvant therapy in the motor rehabilitation of the thoracic limb in patients. However, there is no consensus regarding the stimulation variables or their clinical outcomes. AIM: To describe the results of clinical trials where TMS has been applied in rehabilitation in patients with cerebrovascular disease (CVD). PATIENTS AND METHODS: A systematic review of the PubMed database was performed. The articles cataloged as originals in English, whose population had limitation of thoracic limb after CVD were selected. Pilot studies, as well as studies in which patients under pharmacological treatment included any intervention other than physical or occupational therapy were excluded. Given their heterogeneity, it was not possible to apply inferential statistics, only descriptive statistics were use. RESULTS: Seven studies were identified; 259 cases with an age of 64.3 ± 4.28 years (range: 35-89 years) were reported. The TMS protocols, for the most part, were performed by contralesional inhibitory type stimulation. There were positive results in five studies. CONCLUSION: In accordance with the results obtained, we observed that TMS could contribute to the improvement of motor control of the thoracic limb in patients with sequelae due to CVD.

TITLE: Efecto de la estimulacion magnetica transcraneal sobre la recuperacion motora del miembro toracico en la enfermedad vascular cerebral. Revision sistematica.Introduccion. Existen estudios donde se ha utilizado la estimulacion magnetica transcraneal (EMT) inhibitoria contralesional y excitatoria ipsilesional como terapia coadyuvante en la rehabilitacion motora del miembro toracico; sin embargo, no existe un consenso respecto a las variables de estimulacion ni sobre sus resultados clinicos. Objetivo. Describir los resultados de los ensayos clinicos donde se ha aplicado EMT en la rehabilitacion en pacientes con enfermedad vascular cerebral (EVC). Pacientes y metodos. Se realizo la revision sistematica de la base de datos PubMed. Fueron seleccionados los estudios catalogados como originales en idioma ingles, cuya poblacion tuvo afectacion de miembro toracico tras una EVC. Se excluyeron todos los estudios piloto, ademas de estudios que incluyeran pacientes bajo tratamiento farmacologico o alguna intervencion diferente a terapia fisica u ocupacional. Dada la heterogeneidad percibida en los estudios, no fue posible aplicar estadistica inferencial, unicamente se empleo estadistica descriptiva. Resultados. Fueron seleccionados siete estudios. Se identificaron 259 casos con una edad media de 64,3 ± 4,28 años (rango: 35-89 años). Los protocolos de EMT, en su mayoria, se realizaron mediante estimulacion de tipo inhibitoria contralesional. Hubo resultados positivos en cinco estudios. Conclusion. De acuerdo con los resultados obtenidos, existen indicios de que la EMT podria contribuir a la mejoria del control motor del miembro toracico en los pacientes con secuelas por EVC.

Jamming and percolation for deposition of k

Percolation and jamming of k×k square tiles (k^{2}-mers) deposited on square lattices have been studied by numerical simulations complemented with finite-size scaling theory and exact enumeration of configurations for small systems. The k^{2}-mers were irreversibly deposited into square lattices of sizes L×L with L/k ranging between 128 and 448 (64 and 224) for jamming (percolation) calculations. Jamming coverage θ_{j,k} was determined for a wide range of k values (2≤k≤100 with many intermediate k values to allow a fine scaling analysis). θ_{j,k} exhibits a decreasing behavior with increasing k, being θ_{j,k=∞}=0.5623(3) the limit value for large k^{2}-mer sizes. In addition, a finite-size scaling analysis of the jamming transition was carried out, and the corresponding spatial correlation length critical exponent ν_{j} was measured, being ν_{j}≈1. On the other hand, the obtained results for the percolation threshold θ_{c,k} showed that θ_{c,k} is an increasing function of k in the range 1≤k≤3. For k≥4, all jammed configurations are nonpercolating states and, consequently, the percolation phase transition disappears. An explanation for this phenomenon is offered in terms of the rapid increase with k of the number of surrounding occupied sites needed to reach percolation, which gets larger than the sufficient number of occupied sites to define jamming. In the case of k=2 and 3, the percolation thresholds are θ_{c,k=2}(∞)=0.60355(8) and θ_{c,k=3}=0.63110(9). Our results significantly improve the previously reported values of θ_{c,k=2}^{Naka}=0.601(7) and θ_{c,k=3}^{Naka}=0.621(6) [Nakamura, Phys. Rev. A 36, 2384 (1987)0556-279110.1103/PhysRevA.36.2384]. In parallel, a comparison with previous results for jamming on these systems is also done. Finally, a complete analysis of critical exponents and universality has been done, showing that the percolation phase transition involved in the system has the same universality class as the ordinary random percolation, regardless of the size k considered.

[Treatment of refractory aggressiveness by amygdalotomy and posteromedial hypothalamotomy by radiofrequency]. / Tratamiento de la agresividad refractaria mediante amigdalotomia e hipotalamotomia posteromedial por radiofrecuencia.

INTRODUCTION: Since, under certain circumstances, defensive or attacking behaviours display a pattern of motor dominance, as observed in subjects who participate in contact or fighting sports, aggressive behaviour was considered to have a dominant motor pattern. With the aim of preventing the functional problems reported with bilateral lesion procedures involving both the central nucleus of the amygdala and the posteromedial hypothalamus, the decision was made to combine them; thus, an amygdalotomy of the central nucleus of the amygdala and a posteromedial hypothalamotomy were to be performed simultaneously and unilaterally, on the basis of the motor dominance of the patient determined by means of the Edinburgh test. PATIENTS AND METHODS: This study describes the surgical experience in a series of nine patients diagnosed with refractory neuroaggressive syndrome. As part of the study protocol, a magnetic resonance brain scan was performed to rule out the presence of neoplasms, vascular diseases, infections and degenerative disorders. The degree of aggressiveness was quantified using Yudofsky's Overt Aggression Scale. Additionally, manual dominance was determined by means of the Edinburgh test. RESULTS AND CONCLUSIONS: Good control of aggressiveness was seen immediately. In some cases it was necessary to reduce the antipsychotic or benzodiazepine medication, as it was seen to increase aggressiveness. Only one case required a second surgical intervention. Follow-up was achieved in 100% of the cases at 24 months and 78% at 36 months.

TITLE: Tratamiento de la agresividad refractaria mediante amigdalotomia e hipotalamotomia posteromedial por radiofrecuencia.Introduccion. Dado que, en algunas circunstancias, las conductas defensivas o de ataque muestran un patron de dominancia motora, tal como se observa en los sujetos dedicados a los deportes de contacto o de lucha, se considero que la conducta agresiva tiene un patron motor dominante. Con el fin de evitar los problemas funcionales descritos con los procedimientos de lesion bilateral tanto del nucleo central de la amigdala como del hipotalamo posteromedial, se decidio combinarlos; es decir, realizar amigdalotomia del nucleo central de la amigdala e hipotalamotomia posteromedial de manera unilateral y simultanea, basandose en la dominancia motora del paciente mediante la prueba de Edimburgo. Pacientes y metodos. Este estudio muestra la experiencia quirurgica en una serie de nueve pacientes con el diagnostico de sindrome neuroagresivo resistente al tratamiento farmacologico. Dentro del protocolo de estudio, se les realizo resonancia magnetica cerebral para descartar la presencia de neoplasias, enfermedades vasculares, infecciones y trastornos degenerativos. El grado de agresividad se cuantifico mediante la escala global de agresividad de Yudofsky. Adicionalmente, se determino la dominancia manual a traves de la prueba de Edimburgo. Resultados y conclusiones. El buen control de la agresividad se observo de modo inmediato. En algunos casos fue necesario reducir la medicacion de antipsicoticos o benzodiacepinas, ya que aumentaban la agresividad. Solo un caso requirio una segunda cirugia. Se logro seguimiento del 100% de los casos en 24 meses y del 78% en 36 meses.

[Installed Capacity Perception Survey for the Training of Residents Program in Orthopedics and Care Needs in Acute and Chronic Musculoskeletal Pathology in Mexico]. / Encuesta de Percepción en Capacidad Instalada para la Formación de Médicos Residentes en Ortopedia (Traumatología) y Necesidades de la Atención en Patología Musculoesquelética Aguda y Crónica en México. Primera Parte.

INTRODUCTION: It is essential that orthopaedic resident physicians be highly proficient in all aspects, considering the balance between supply, demand, need and context. Fundamental to identify the capacity and quality installed for their training in Mexico. MATERIAL AND METHODS: Observational Study, transverse, non-probabilistic sampling-conglomerates, in two phases. The instrument has 8 domains, 57 variables and 4,867 items. 60 graduate professors of 20 states, 50 hospital sites, 22 university programs. RESULTS: 1,038 years of experience (collective intelligence), 17 years of experience/teacher (01 to 50 years). Identified: acute pathology 30 (2 to 90%), chronic pathology 30 (5 to 96%), patients 15 years, 10 (3 to 30%), patients between 15 and 65 years, 47 (2 to 78%), patients 65 years, 20 (2 to 60%), number of beds/seat 20 (2 to 510), number of clinics 3 (1 to 48), number of surgical procedures/headquarters per year at the national level, was 960 (50 to 24,650). The national average per resident doctor is 362 surgeries/year with 1,450 surgical times/year. CONCLUSIONS: The needs and resources for the training of physicians specializing in orthopedics/traumatology are highly heterogeneous, so it should be adapted to the epidemiological needs of the region of influence, in an area of epidemiological transition. 62.2% expressed not having or have bad academic and scientific infrastructure at its headquarters, more than 50% without rotation overseas and 90% without regular scientific production.

INTRODUCCIÓN: Es fundamental que los médicos residentes de ortopedia (traumatología) sean altamente competentes en todos los aspectos, considerando el equilibrio entre la oferta, demanda, necesidad y contexto. Es primordial identificar la capacidad y calidad instalada para su formación en México. MATERIAL Y MÉTODOS: Estudio observacional, transversal, muestreo no probabilístico-conglomerados, en dos fases. El instrumento tiene ocho dominios, 57 variables y 4,867 ítems. Sesenta profesores de postgrado de 20 estados, 50 sedes hospitalarias, 22 programas universitarios. RESULTADOS: 1,038 años de experiencia (inteligencia colectiva), 17 años de experiencia/profesor (01 a 50 años). Se identificó: patología aguda 30 (2 a 90%), patología crónica 30 (5 a 96%), pacientes 15 años, 10 (3 a 30%), pacientes entre 15 y 65 años, 47 (2 a 78%), pacientes 65 años, 20 (2 a 60%), número de camas/sede 20 (2 a 510), número de consultorios 3 (1 a 48), el número de procedimientos quirúrgicos/sede al año a nivel nacional fue de 960 (50 a 24,650). La media nacional por médico residente es de 362 cirugías/año con 1,450 momentos quirúrgicos/año. CONCLUSIONES: Las necesidades y recursos para la formación de médicos especialistas en ortopedia/traumatología son en alto grado heterogéneos, por lo cual se debería adaptar a las necesidades epidemiológicas de la región de influencia, en un ámbito de transición epidemiológica. Sesenta y dos punto dos por ciento expresó no tener o tener deficiente infraestructura académica y científica en su sede, más de 50% sin rotación al extranjero y 90% sin producción científica regular.

Long-lasting, reversible and non-neurotoxic inactivation of hippocampus activity induced by neosaxitoxin.

BACKGROUND: Neosaxitoxin (NeoSTX) and related paralytics shellfish toxins has been successfully used as local anesthetic and muscle relaxants to treat a variety of ailments. The primary mechanism of action of these toxins occurs by blocking voltage-gated sodium channels with compounds such as TTX, lidocaine, or derivatives. However, most of these non-classical sodium channel blockers act with a reduced time effect as well as ensuing neurotoxicity. NEW METHOD: In this report, we show that the use of local NeoSTX injections inactivates the hippocampal neuronal activity reversibly with a by long-term dynamics, without neuronal damage. RESULTS: A single 10 ng/µl injection of NeoSTX in the dorsal CA1 region abolished for up to 48 h memory capacities and neuronal activity measured by the neuronal marker c-fos. After 72 h of toxin injection, the animals fully recover their memory capacities and hippocampal neuronal activity. The histological inspection of NeoSTX injected brain regions revealed no damage to the tissue or reactive gliosis, similar to vehicle injection. Acute electrophysiological recording in vivo shows, also, minimal spreading of the NeoSTX in the cerebral tissue. COMPARISON WITH EXISTING METHODS: Intracerebral NeoSTX injection showed longer effects than other voltage sodium channel blocker, with minimal spreading and no neuronal damage. CONCLUSION: NeoSTX is a new useful tool that reversibly inactivates different brains region for a long time, with minimal diffusion and without neuronal damage. Moreover, NeoSTX can be used as a valuable sodium channel blocker for many studies in vivo and with potential therapeutic uses.

Heterologous expression of phaC2 gene and poly-3-hydroxyalkanoate production by recombinant Cupriavidus necator strains using canola oil as carbon source.

Many heterologous transformation studies have been carried out using the Cupriavidus necator PHB-4 strain to investigate the expression characteristics of various polyhydroxyalkanoate (PHA) synthase enzymes. In this study, we generated a recombinant C. necator PHB-4 strain by transforming a plasmid (pMRC03) harbouring the synthetic phaC2 gene of Pseudomonas putida CA-3. Under conditions favourable for expression of the phaC2 P.putCA-3 gene, canola oil was used as carbon source for the synthesis of PHAs. The expressed synthase polymerised monomers of 3-hydroxybutyrate (3-HB), 3-hydroxyvalerate (3-HV) and 3-hydroxyhexanoate (3-HHx) in the recombinant C. necator PHB-4 (pMRC03) strain. We then co-expressed the phaC2P.putCA-3 gene with the native phaC1C.ne gene in wild type Cupriavidus necator H16 (C. necator H16 (pMRC03)). This co-expression produced a PHA blend of 3-HB, 3-HV, 3-HHx and 3-hydroxyoctanoate (3-HO) monomers in the presence of canola oil. Gas chromatography analysis revealed the presence of 94mol% 3-HB, 1mol% 3-HV, 4mol% 3-HHx and 1mol% 3-HO in a tetra-polymer. Thus, we confirmed that a synthetic phaC2 gene encoding the synthase enzyme is functionally active with substrates ranging from short to medium chain length PHAs.

[Cervantes and Shakespeare, two Renaissance neurologists]. / Cervantes y Shakespeare, dos neurologos renacentistas.

TITLE: Cervantes y Shakespeare, dos neurologos renacentistas.

Jamming for nematic deposition in the presence of impurities.

The deposition of one-dimensional objects (such as polymers) on a one-dimensional lattice with the presence of impurities is studied in order to find saturation conditions in what is known as jamming. Over a critical concentration of k-mers (polymers of length k), no further depositions are possible. Five different nematic (directional) depositions are considered: baseline, irreversible, configurational, loose-packing, and close-packing. Correspondingly, five jamming functions are found, and their dependencies on the length of the lattice, L, the concentration of impurities, p=M/L (where M is the number of one-dimensional impurities), and the length of the k-mer (k) are established. In parallel, numeric simulations are performed to compare with the theoretical results. The emphasis is on trimers (k=3) and p in the range [0.01,0.15], however other related cases are also considered and reported.