Feasibility of using rural waste products to increase the denitrification efficiency in a surface flow constructed wetland

A surface flow constructed wetland (CW) was set in the Lerma gully to decrease nitrate (NO3−) pollution from agricultural runoff water. The water flow rate and NO3− concentration were monitored at the inlet and the outlet, and sampling campaigns were performed which consisted of collecting six water samples along the CW flow line. After two years of operation, the NO3− attenuation was limited at a flow rate of ~2.5 L/s and became negligible at ~5.5 L/s. The present work aimed to assess the feasibility of using rural waste products (wheat hay, corn stubble, and animal compost) to induce denitrification in the CW, to assess the effect of temperature on this process, and to trace the efficiency of the treatment by using isotopic tools. In the first stage, microcosm experiments were performed. Afterwards, the selected waste material was applied in the CW, and the treatment efficiency was evaluated by means of a chemical and isotopic characterization and using the isotopic fractionation (ε) values calculated from laboratory experiments to avoid field-scale interference. The microcosms results showed that the stubble was the most appropriate material for application in the CW, but the denitrification rate was found to decrease with temperature. In the CW, biostimulation in autumn-winter promoted NO3− attenuation between two weeks and one month (a reduction in NO3− between 1.2 and 1.5 mM was achieved). After the biostimulation in spring-summer, the attenuation was maintained for approximately three months (NO3− reduction between 0.1 and 1.5 mM). The ε15NNO3/N2 and ε18ONO3/N2 values obtained from the laboratory experiments allowed to estimate the induced denitrification percentage. At an approximate average flow rate of 16 L/s, at least 60% of NO3− attenuation was achieved in the CW. The field samples exhibited a slope of 1.0 for δ18O-NO3− versus δ15N-NO3−, similar to those of the laboratory experiments (0.9-1.2). Plant uptake seemed to play a minor role in NO3− attenuation in the CW. Hence, the application of stubble in the CW allowed the removal of large amounts of NO3− from the Lerma gully, especially when applied during the warm months, but its efficacy was limited to a short time period (up to three months)

Estudio de carcinoma medular de tiroides a partir de un caso índice

El carcinoma de tiroides es un tumor infrecuente; constituye menos del 1% de las neoplasias malignas en la población general y el 0, 5%-3% en la edad pediátrica. Existen cuatro tipos: papilar (80%-90% de los casos), folicular (5%-10%), medular (5%) y anaplásico (2%-3%). En el tipo medular, el 80% son esporádicos, y un 20% se asocia a un síndrome hereditario que se divide, fundamentalmente, en tres grupos: neoplasia endócrina múltiple 1, neoplasia endócrina múltiple 2 y carcinoma medular de tiroides familiar. Las formas hereditarias se producen por una mutación en el protooncogén RET, localizado en el brazo largo del cromosoma 10. Se presenta un caso de carcinoma medular de tiroides detectado a raíz de un estudio genético familiar con el propósito de resaltar la importancia del diagnóstico precoz y la intervención de equipos multidisciplinares expertos en esta patología para su manejo y seguimiento. Thyroid cancer is an uncommon type of cancer, accounting less than 1% of all cancers in adults, and 0.5-3% of all cancers in children. There are four different types: papillary carcinoma (80-90% of cases), follicular (5-10%), medullary (5%) and anaplastic cell (2-3%). Eighty per cent of cases of medullary thyroid cancer are sporadic, but 20% are associated with an inherited syndrome that is divided into three groups: multiple endocrine neoplasia type 1, multiple endocrine neoplasia type 2 and familial medullary thyroid carcinoma. The inherited forms are caused by a disruption in the RET oncogene, which is located in the long arm of chromosome 10. A hereditary case of medullary thyroid carcinoma is presented. It was detected because of a familial genetic study. The purpose of the paper is emphasize the importance of the early diagnosis and the intervention of multidisciplinary teams of experts

Hypothalamyc hamartomas: Different ways of clinical debut. Cases report

Los hamartomas hipotalámicos son malformaciones no neoplásicas de sustancia gris compuestas por neuronas hiperplásicas. Suelen ser lesiones pequeñas localizadas en la base del cerebro, en el piso del tercer ventrículo y, generalmente, asintomáticas. Sin embargo, pueden ocurrir con alteraciones conductuales-cognitivas, crisis epilépticas y/o signos de pubertad precoz central en función de la localización en la que se encuentren. Se presentan dos pacientes de 2 años 8 meses y 7 años, con presencia de hamartomas hipotalámicos diagnosticados tras el estudio de pubertad precoz central. La paciente de menor edad presenta, además, crisis gelásticas, típicamente asociadas a hamartomas hipotalámicos. Tras los hallazgos clínicos y radiológicos, se trataron con análogos de gonadotropinas, y se observó una regresión de los signos puberales y una no progresión del tamaño de los hamartomas. Hypothalamic hamartomas are benign tumors of gray substance composed by hyperplasic neurons. They are usually asymptomatic small masses with extensions into the third ventricular cavity. In some instances they can cause cognitive behavioral alterations, seizures and/or central precocious puberty depending on the location. Here we present two cases of central precocious puberty due to hypothalamic hamartomas at 28/12 and 7 years of age. The younger patient also presents gelastic seizures, typically associated with hypothalamic hamartomas. After the clinical and radiological findings, they started treatment with GnRH analogues and a regression of the puberty signs without progression in the hamartomas size was observed

Hypogonadotropic hypogonadism in Klinefelter syndrome and hypothalamic-pituitary tumor

El síndrome de Klinefelter es la causa más frecuente de hipogonadismo hipergonadotropo en el varón. La supresión en la respuesta al estímulo con hormona liberadora de la hormona luteinizante en estos pacientes debe hacer sospechar como posible etiología una tumoración a nivel hipotalámico. Se presenta el caso de un paciente diagnosticado a los 4 meses con síndrome de Klinefelter mediante cribado neonatal, con cariotipo 47 XXY, en el que se realizan controles clínicos y analíticos seriados y se encuentran, a los 17 años, valores suprimidos de hormona luteinizante y hormona folículo estimulante. Inicia, posteriormente, cefalea y amaurosis de ojo izquierdo, y se encuentra, en una resonancia magnética cerebral, un tumor germinal mixto a nivel hipotalámico, que precisa tratamiento quirúrgico, quimioterapia y radioterapia, con respuesta favorable. Klinefelter Syndrome is the most frequent cause of hypergonadotropic hypogonadism in men. A flat response at luteinizing hormone releasing hormone stimulation test could be the first sign of hypothalamic tumor in these patients. We report the case of a patient diagnosed by neonatal screening with Klinefelter Syndrome, 47 XXY, that at 17 years follow-up presents analytical modification of the response to luteinizing hormone releasing hormone stimulation test with suppressed luteinizing hormone and follicle-stimulating hormone values; lately he presents with headache and loss of left eye vision. A magnetic resonance imaging of the brain showed a mixed germ cell hypothalamus tumor, requiring surgery, chemotherapy and radiotherapy with optimal response

Magnetic relaxation in La0.250Pr0.375Ca0.375MnO3 with varying phase separation

We have studied the magnetic relaxation properties of the phase-separated manganite compound La0.250Pr0.375Ca0.375MnO3 . A series of polycrystalline samples was prepared with different sintering temperatures, resulting in a continuous variation of phase fraction between metallic (ferromagnetic) and charge-ordered phases at low temperatures. Measurements of the magnetic viscosity show a temperature and field dependence which can be correlated to the static properties. Common to all the samples, there appears to be two types of relaxation processes - at low fields associated with the reorientation of ferromagnetic domains and at higher fields associated with the transformation between ferromagnetic and non-ferromagnetic phases.Comment: 30 pages with figures, PDF, accepted to be published in Physical Review