Tracing the Spatial Distribution of Whole-Lake Exchange of Groundwater and Lake Water in Low-Hydraulic Gradient Systems Using delta O-18 and Electrical Conductivity and Uncertain End-Member Mixing Analysis

δ18O and electrical conductivity (EC) were used successfully to trace the spatial distribution of whole-lake groundwater-lake exchange for a small (four ha) groundwater-fed lake situated in a low relief and low hydraulic gradient area. The method relies on quick sampling of shallow groundwater, direct analysis of EC in the field, and relatively in-expensive analysis of δ18O in the laboratory. Ternary uncertain end-member mixing analysis (precipitation, groundwater, and lake water) quantified the composition of water discharging to and recharging from the lake. The tracer distribution and mixing analysis were in agreement with the interpreted groundwater flow near the lake. The use of only one tracer (either δ18O or EC) gave the same results for the recharge segments, but the discharge segments changed the origin of the water from being groundwater to precipitation controlled. The two tracers complemented each other, especially with different signals in precipitation and groundwater. The uncertain end-members were assessed based on local (groundwater and lake water) and off-site (precipitation) data. The off-site data were found to be useful if it contained representative information on local-site seasonality (uncertainty, variance). Final end-member concentrations could explain the transience of the hydrology at the site (i.e., flooding of the area adjacent to the lake during periods with high precipitation, and variability of the δ18O signal in precipitation). This methodology potentially represents a new option to study groundwater-lake systems. The tracer information collected over only two days is useful by itself for developing the next steps like the quantification of fluxes based on other standard methods (Darcy approach, seepage meters, or temperature). The tracer information can provide quantitative estimation of inputs and outputs by using the mixing analysis

BRAF and TERT mutations in papillary thyroid cancer patients of Latino ancestry.

Papillary thyroid cancer (PTC) is the second most commonly diagnosed malignancy in U.S. Latinas and in Colombian women. Studies in non-Latinos indicate that BRAF and TERT mutations are PTC prognostic markers. This study aimed to determine the prevalence and clinical associations of BRAF and TERT mutations in PTC Latino patients from Colombia. We analyzed mutations of BRAF (V600E) and TERT promoter (C228T, C250T) in tumor DNA from 141 patients (75 with classical variant PTC, CVPTC; 66 with follicular variant PTC, FVPTC) recruited through a multi-center study. Associations between mutations and clinical variables were evaluated with Fisher exact tests. Survival was evaluated with Kaplan-Meier plots. Double-mutant tumors (BRAF+/TERT+, n = 14 patients) were more common in CVPTC (P = 0.02). Relative to patients without mutations (n = 48), double mutations were more common in patients with large tumors (P = 0.03), lymph node metastasis (P = 0.01), extra-thyroid extension (P = 0.03), and advanced stage (P = 6.0 × 10-5). In older patients, TERT mutations were more frequent (mean age 51 years vs 45 years for wild type TERT, P = 0.04) and survival was lower (HR = 1.20; P = 0.017); however, given the small sample size, the decrease in survival was not statically significant between genotypes. Comparisons with published data in US whites revealed that Colombian patients had a higher prevalence of severe pathological features and of double-mutant tumors (10 vs 6%, P = 0.001). Mutations in both oncogenes show prognostic associations in Latinos from Colombia. Our study is important to advance Latino PTC precision medicine and replicates previous prognostic associations between BRAF and TERT in this population

The HABP2 G534E polymorphism does not increase nonmedullary thyroid cancer risk in Hispanics.

Familial nonmedullary thyroid cancer (NMTC) has not been clearly linked to causal germline variants, despite the large role that genetic factors play in risk. Recently, HABP2 G534E (rs7080536A) has been implicated as a causal variant in NMTC. We have previously shown that the HABP2 G534E variant is not associated with TC risk in patients from the British Isles. Hispanics are the largest and the youngest minority in the United States and NMTC is now the second most common malignancy in women from this population. In order to determine if the HABP2 G534E variant played a role in NMTC risk among Hispanic populations, we analyzed 281 cases and 1105 population-matched controls from a multicenter study in Colombia, evaluating the association through logistic regression. We found that the HABP2 G534E variant was not significantly associated with NMTC risk (P=0.843) in this Hispanic group. We also stratified available clinical data by multiple available clinicopathological variables and further analyzed the effect of HABP2 on NMTC presentation. However, we failed to detect associations between HABP2 G534E and NMTC risk, regardless of disease presentation (P≥0.273 for all cases). Therefore, without any significant associations between the HABP2 G534E variant and NMTC risk, we conclude that the variant is not causal of NMTC in this Hispanic population

Understanding the conformational changes and molecular structure of furoyl thioureas upon substitution

1-Acyl thioureas [R1C(O)NHC(S)NR2R3] are shown to display conformational flexibility depending on the degree of substitution at the nitrogen atom. The conformational landscape and structural features for two closely related thioureas having R1 = 2-furoyl have been studied. The un-substituted 2-furoyl thiourea (I) and its dimethyl analogue, i.e. 1-(2-furoyl)-3,3-dimethyl thiourea (II), have been synthesized and fully characterized by spectroscopic (FT-IR, 1H and 13C NMR) and elemental analysis. According to single crystal X-ray diffraction analysis, compounds I and II crystallize in the monoclinic space group P21/c. In the compound I, the trans–cis geometry of the almost planar thiourea unit is stabilized by intramolecular Nsingle bondH ⋯ Odouble bondC hydrogen bond between the H atom of the cis thioamide and the carbonyl O atom. In compound II, however, the acyl thiourea group is non-planar, in good agreement with the potential energy curve computed at the B3LYP/6-31 + G(d,p) level of approximation. Centrosymmetric dimers generated by intermolecular N — H ⋯ O = C hydrogen bond forming R22(8) motif are present in the crystals. Intermolecular interactions have been rationalized in terms of topological partitions of the electron distributions and Hirshfeld surface analysis, which showed the occurrence of S ⋯ H, O ⋯ H and H ⋯ H contacts that display an important role to crystal packing stabilization of both thiourea derivatives.Instituto de Física La PlataCentro de Química Inorgánic

Freezing of epididymal canine sperm with centrifuged egg yolk

El objetivo de esta investigación fue evaluar el uso de yema de huevo centrifugada (YHC) en la congelación de espermatozoides epididimales caninos. Se obtuvieron los complejos testículo-epidídimo (CTE) después de la orquiectomía de 20 perros domésticos (Canis familiaris) de varias razas y en un rango de edad entre 1 y 6 años. Se diseccionó la cola del epidídimo y se obtuvieron los espermatozoides mediante la técnica de flujo retrógrado. Los espermatozoides obtenidos se dividieron en dos alícuotas y se diluyeron en Triladyl® suplementado con YHC al 10% (YHC10) o YHC al 20% (YHC20). Se realizó la congelación del semen mediante un protocolo convencional con vapores de nitrógeno líquido en pajillas para 0.5 ml. Se utilizó un sistema computarizado para evaluar la movilidad, la cinética y la concentración de los espermatozoides. Adicionalmente, se evaluaron posdescongelación la vitalidad espermática (VE), la morfología anormal (MA) y la integridad de la membrana plasmática (HOS). El análisis estadístico se realizó mediante el ajuste de modelos lineales generalizados (GLM) y la comparación de medias por la prueba de Tukey. Para YHC10 se encontraron valores superiores para las velocidades lineal (VSL), curvilínea (VCL) y media (VAP) en comparación con YHC20 (p<0.05). No se encontraron diferencias relacionadas con la concentración de YHC para otros parámetros de movilidad y cinética espermática, así como para VE, MA y HOS. Se concluye que la YHC puede ser utilizada como suplemento para la congelación de semen epididimal canino. Adicionalmente, cuando la YHC se utiliza en una proporción del 10% del diluyente, favorece la cinética espermática posdescongelación.The aim of this research was to evaluate the use of centrifuged egg yolk (CEY) in the freezing process of canine epididymal spermatozoa. Testicular-epididymis complexes (TECs) were obtained after the orchiectomy of 20 domestic dogs (Canis familiaris) of different breeds and with an age range between 1 and 6 years. The tail of the epididymis was dissected and spermatozoa were obtained by the retrograde flow technique. The spermatozoa were divided into two aliquots and extended in Triladyl® supplemented with 10% CEY (CEY10) or 20% CEY (CEY20). Semen freezing was performed using a standard protocol with liquid nitrogen vapors and semen was packed in straws of 0.5 ml. A computerized system was used to evaluate the motility, kinetics and concentration of spermatozoa. In addition, post-thawing sperm vitality (VE), abnormal morphology (MA) and plasma membrane integrity (HOS) were evaluated. Statistical analysis was performed by adjusting generalized linear models (GLM) and comparing means by the Tukey test. For CEY10 higher values for linear (VSL), curvilinear (VCL) and mean (VAP) velocities were found compared to CEY20 (p<0.05). There were no differences related to the concentration of CEY for other parameters as motility, sperm kinetics, VE, MA and HOS. It is concluded that CEY can be used as supplement for the freezing process of canine epididymal semen. Additionally, when the CEY is used in a proportion of 10% of the extender, it favors the post-thawing sperm kinetics

Percepciones y creencias de los docentes de algunas escuelas públicas de Pereira sobre el comportamiento agresivo de los niños

El comportamiento agresivo crónico de los niños es un factor de riesgo para depresión, abuso de alcohol en la adolescencia y vida adulta; violencia contra los compañeros, bajo rendimiento escolar, infracción de normas, lo que más adelante puede convertirse en un predictor (en adolescentes y adultos) de maltrato físico a los hijos, asaltos físicos a las esposas, menor posibilidad de profesionalización y aumento de la probabilidad de conducta antisocial. Publicaciones a nivel nacional e internacional afirman que hay tendencia en reproducir por fuera del hogar la violencia vivida en la familia, debido a la existencia de un proceso de transmisión intergeneracional de este tipo de violencia1,2.Esta conducta de los niños puede ser intervenida en la escuela a través del desarrollo y fortalecimiento de competencias en maestros, ya que al ser reconocidas por los maestros, les permite difundir modelos observados por los niños y niñas, que propenden en la disminución del comportamiento agresivo en los estudiantes. Estos comportamientos observados pueden constituirse en competencias que ponen en práctica de manera integrada aptitu-des, rasgos de personalidad y conocimientos.AbstractThe aggressive chronic behavior of the children is a factor of risk for depression, abuse of alcohol in the adolescence and adult life; violence against the partners, lower performance at school, breach of norms. All of this can turn later into a predictor (in adolescents and adults) of physical ill-treatment to the children, physical assaults to wives, minor possibility of professionalization and an increasing of the probability of antisocial behavior, Publications at national and international level affirm that there is tendency in reproducing outside of the household the violence that was undergone in the family, due to the existence of a process of “inter-generational transmission of this type of violence.” This behavior of the children can be controlled in the school through the development and strengthening of competences in teachers. These competences must allow the recognition of the different behaviors of the persons and make the teachers effective in the diffusion of models that are followed by the children and girls to strive for the decrease of the aggressive behavior in the students. These observed behaviors can be turned into competences that to put in practice, in an integrated way, aptitudes, features of personality and knowledge. “ The Municipal Secretary of Education of Pereira organized a course titled: STRATEGIES FOR THE REDUCTION OF AGGRESSIVE BEHAVIORS OF THE CHILDREN (EXPERT), which was designed by the team of investigators and endorsed by the Technological University of Pereira. In the course, it was seen that some competences, after having been practiced by the teachers, might be strengthened by them themselves and applied to the children, propitiating spaces for the interiorización and appropriation of them. Once identified, the team of every institution and in general with the educational community, are headed towards a work of personal improvement and valuation of the human capital with which they are provided. In order to begin that intervention, they started from a call that was carried out through the Secretary of Education of Pereira, with the support of the Unit of Integral Attention UAI in the random selection within the schools of the urban area. 120 teachers from 12 public schools of Pereira were met between March and June, 2006. ; A survey was carried out to evaluate the knowledge about the strategies tending to the reduction of aggressive behaviors, by means of the application of instruments designed to that end. It was found that in general the teachers have the theoretical knowledge of the proposed strategies: importance of the communication, pacific resolution of conflicts, respect for the difference; nevertheless in the practice to encourage the achievement of these competences in the children, the teachers need support. The teachers are aware of the magnitude of the emotional, familiar and social problems that their students have. And because of the fact that they feel that they are not receiving help to solve the precarious situations of the children, (mostly socioeconomic, emotional) it generates feelings of powerlessness, distresses, worry, fright. sadness, pain and a high grade of frustration. All of this results in the questioning by some of them of their performance as teachers and feel skepticism about the initiatives proposed to contribute from the classroom with the social and familiar well-being to the children.Key words: perceptions and beliefs of teachers, aggressiveness in theschool, school interventions to reduce aggressiveness

Exciton properties in zincblende InGaN-GaN quantum wells under the effects of intense laser fields

ABSTRACT: In this work, we study the exciton states in a zincblende InGaN/GaN quantum well using a variational technique. The system is considered under the action of intense laser fields with the incorporation of a direct current electric field as an additional external probe. The effects of these external influences as well as of the changes in the geometry of the heterostructure on the exciton binding energy are discussed in detail