3,588 research outputs found
Cambios morfosedimentarios causados por la construcción de un espigón en Camet norte, provincia de Buenos Aires, Argentina
Se dan a conocer los diversos cambios morfosedimentarios que se produjeron en un sector de costa ubicado al norte de un espigón construido en Camet Norte (Buenos Aires) a fines del año 2011. Durante el período analizado (julio 2011-diciembre 2015) se observó en un punto de control ubicado a 200 m al norte de la estructura, aguas abajo respecto a la deriva litoral, que el nivel de arena en playa rara vez fue superior al valor registrado en julio de 2011, cuatro meses antes de la construcción de la obra.
Lo contrario sucedió con otros tres puntos de control distantes a más de 1.275 m del nuevo espigón, en donde rara vez el nivel de arena fue inferior al observado en esa fecha (julio 2011). A su vez, a lo largo del año la granulometría de la arena correspondiente a la playa frontal del área monitoreada cercana a la obra, por lo general fue más gruesa respecto a los restantes puntos de control, indicando posiblemente una mayor energía de ola en ese sector de costa. El menor nivel de arena asociado a una mayor energía de ola en el sector próximo a la estructura, permitió probablemente la afluencia directa del embate de las mismas durante todo el período, reflejándose esto en un mayor retroceso del acantilado y sobre todo del microacantilado, con un total de 96 y 350 cm (22 y 79 cm/año), respectivamente. Estos retrocesos están asociados preferentemente a eventos de corta duración correspondientes a tormentas marítimas denominadas localmente “sudestadas”.Our study shows several morphodynamic changes occurred along a coastal sector downstream of a groin built at Camet Norte locality (Buenos Aires province) by the end of 2011. During the time span analyzed (July 2011-December 2015), at a control site located 200 m north of the structure, downstream relative to the littoral drift, it was possible to observe that the sand level on the beach was seldom higher than that recorded in July 2011, four months before the groin was built. The opposite occurred in other three control sites placed more than 1,275 m far from the new groin, where the sand level was seldom lower than that observed in July 2011. In addition, along the whole year, the size of the sandy particles of the foreshore in the area localized near the structure was generally higher than that of the remaining control sites, suggesting stronger wave energy within the corresponding coastal sector. Most probably, within control site localized next to groin coastal sector a lower sandy level together with stronger wave energy allowed a direct influx and effect of the waves during the whole time span. This is reflected by a stronger retreat of the main cliff and especially the microcliff, with a total of 96 and 350 cm (22 and 79 cm/year), respectively.
These retreats are linked mainly to short marine events locally known as “sudestadas”
The Effect of Food Vouchers and an Educational Intervention on Promoting Healthy Eating in Vulnerable Families: A Pilot Study
Cost has been reported as the main barrier to healthy eating in vulnerable groups. We aimed to evaluate the effect of a nutrition education intervention on adherence to Mediterranean Diet and health when providing food vouchers. This pilot study has a randomized control trial design. We included 66 vulnerable users from the Red Cross of Zaragoza (Spain). Intervention and control group individuals received 120 euros/month of food vouchers over 3 months to be spent in supermarkets (60 euros/month if under 12 y) plus a 10-week nutrition education program for the intervention group. Family food purchases were assessed using electronically recorded supermarket-obtained transactions. During and at the end of the intervention the percentage of healthy food was higher in the intervention than in the control group. Once the nutrition education was over, differences between groups dissipated. In the intervention group, health parameters improved, particularly weight-status, lipids, and liver enzymes. Control participants gained weight, although lipid and liver enzymes improved. Blood pressure and HbA1c did not improve in either the intervention or the control group. In conclusion, providing unrestricted food vouchers to vulnerable groups to increase healthy food consumption appears to be insufficient and should be accompanied by medium-long term nutrition education
Efficacy of capacitive resistive monopolar radiofrequency in the physiotherapeutic treatment of chronic pelvic pain syndrome : study protocol for a randomized controlled trial
Chronic pelvic pain syndrome (CPPS) is a multifactorial disorder that affects 5.7% to 26.6% of women and 2.2% to 9.7% of men, characterized by hypersensitivity of the central and peripheral nervous system affecting bladder and genital function. People with CPPS have much higher rates of psychological disorders (anxiety, depression, and catastrophizing) that increase the severity of chronic pain and worsen quality of life. Myofascial therapy, manual therapy, and treatment of trigger points are proven therapeutic options for this syndrome. This study aims to evaluate the efficacy of capacitive resistive monopolar radiofrequency (CRMRF) at 448kHz as an adjunct treatment to other physiotherapeutic techniques for reducing pain and improving the quality of life of patients with CPPS. This triple-blind (1:1) randomized controlled trial will include 80 women and men with CPPS. Participants will be randomized into a CRMRF activated group or a CRMRF deactivated group and receive physiotherapeutic techniques and pain education. The groups will undergo treatment for 10 consecutive weeks. At the beginning of the trial there will be an evaluation of pain intensity (using VAS), quality of life (using the SF-12), kinesiophobia (using the TSK-11), and catastrophism (using the PCS), as well as at the sixth and tenth sessions. The results of this study will show that CRMRF benefits the treatment of patients with CPPS, together with physiotherapeutic techniques and pain education. These results could offer an alternative conservative treatment option for these patients. ClinicalTrials.gov . Registered on 8 January 2019. The online version contains supplementary material available at 10.1186/s13063-021-05321-6
Estudio taxonómico preliminar de la ficoflora planctónica en la zona aluvial del Río Colorado (La Pampa, Argentina)
This work is part of a larger project on the study of algal biodiversity of a lotic system in La Pampa province. In this first stage we analyze the algal flora of samples collected during the summer season and autumn of 2010. The study area is located in the floodplain of the Colorado River, the natural boundary between the provinces of La Pampa and Río Negro at its intersection with Provincial Route 11 (Department Lihuel Calel). The methodology used in the collection followed the standard parameters for lotic environments. The samples were fixed with 4% formaldehyde and deposited in the herbarium of the Faculty of Agronomy (UNLPam) under the symbol SRFA. The preliminary results of the algal flora of summer and autumn shows 64 taxa, of which 26.5% corresponds to Cyanophyceae, 36% to Chlorophyceae and Bacillariophyceae, and 1.5% to Dinophyceae. During the summer the class Chlorophyceae species contributed 40% and fall did the Bacillariophyceae with 43.7%. The 37.5% of the registered species were common to both seasons
Land Use Patterns in Central Asia. Step 1: The Musical Chairs Model
Herding and farming coexisted in Central Asia for several thousand years as main options of preindustrial economic production. The relationship between people practicing different variants of these modes of subsistence is known to have been dynamic. Among the many possible explanations, we explore this dynamic by modeling mechanisms that connect aggregate decisions to land use patterns. Within the framework of the SimulPast project, we show here the results from step 1 of our modeling program: the Musical Chairs Model. This abstract agent-based model describes a mechanism of competition for land use between farming and herding. The aim is the exploration of how mobility, intensity, and interdependence of activities can influence land use pattern. After performing a set of experiments within the framework of this model, we compare the implications of each condition for the corroboration of specific land use patterns. Some historical and archaeological implications are also discussed. We suggest that the overall extension of farming in oases can be explained by the competition for land use between farming and herding, assuming that it develops with little or no interference of climatic, geographical, and historical contingencies
Headache, Delirium or Encephalitis?:A Case of Residual Mutism Secondary to Anti-NMDA Receptor Encephalitis
Encephalitis is a heterogeneous syndrome that is diagnosed through clinical assessment and the assistance of laboratory, neuroimaging and electroencephalographic workup. Over the past 10 years, autoimmune encephalitis has been more frequently recognized; however, most reports come from highly specialized hospital settings. Anti-N-methyl-D-aspartate receptor (NDMAR) encephalitis has been associated with paraneoplastic encephalitis syndromes and was first recognized in 2005. We present the case of a 34-year-old male patient who debuted clinically with a headache associated with neuropsychiatric symptoms (i.e., visual and auditory hallucinations, anxiety, aggressiveness) and memory deficits, progressing to autonomic dysfunction (i.e., tachycardia and hypertension), seizures, and stupor with catatonic features. Initially, infectious, metabolic, and toxicological etiologies were excluded; followed by the assessment of immunological and paraneoplastic etiologies, yielding positive IgG levels for anti-NMDAR antibodies. The patient was treated successfully with systemic steroid therapy and therapeutic plasmapheresis, while mutism was the only sequela. Although large case series reporting on paraneoplastic and autoimmune anti-NMDAR encephalitis have been reported in the literature in recent years, this case is of particular importance due to the stepwise differential diagnosis and treatment management procedure that was used in a regional but not highly specialized hospital setting
Metabolic engineering for improving anthranilate synthesis from glucose in Escherichia coli
© 2009 Balderas-Hernández et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Spheroidal halloysites from Patagonia, Argentina: Some aspects of their formation and applications
Halloysite deposits in Argentina have been identified in the province of Río Negro (Patagonia). The mineralized area occurs as altered zones in Eocene volcanic–pyroclastic rocks, dacitic to rhyolitic in composition. A comprehensive study of these deposits was carried out by means of mineralogical, geochemical and isotopic analyses.
Intenseweathering has transformed the whole rock to a whitemass composed of 75% –90% halloysite+kaolinite, with cristobalite, tridymite, and quartz, as the main non-clay minerals. Ferruginous beidellite and titanium minerals are also present in minor amounts.
The halloysite–kaolinite ratio ranges from 75 to 25 to 100–0. Due to the alteration of very dense rocks, halloysite morphology is predominantly spheroidal. Tubular halloysite is the main constituent in more porous rocks, but the latter are scarce in the area.
Because of the predominance of the spheroidal type, the use of halloysite asHNT (halloysite nanotube) is not feasible.
Nonetheless, this mineral can be modified by different organic molecules, and used to remove pollutants such as emulsified hydrocarbons and heavy metals. A special product made with this halloysite is used as sunscreen when sprayed on fruits in areas of intense solar radiation. The whiteness of this mineral is not very high due to the amount of titanium oxide present in its composition (about 1%). Nevertheless, titanium oxide is present as individual particles, so it could be removed by a mechanical process.
New applications for spheroidal halloysite are currently being investigated. Moreover, depending on the price and demand, the tubular halloysite of low grade deposits could be exploited
Estética en odontopediatría: restauración indirecta con resina compuesta en dentición primaria
El objetivo del presente trabajo fue realizar una restauración indirecta de resina de fotocurado de clase II en un segundo molar primario y presentar los pasos operatorios realizados como una alternativa estética terapéutica. Paciente de 8 años de edad de sexo femenino asistió para su rehabilitación integral a la Especialidad de Odontopediatría de la Facultad de Odontología de la UNNE. Al examen clínico la pieza dentaria 6.5 presentó una caries inactiva de Clase II compleja, en la cual dentro del plan de tratamiento rehabilitador se decidió realizar una restauración indirecta de resina de fotocurado. Las restauraciones indirectas para molares con resina de fotocurado confeccionado extraoralmente, son una posible alternativa estética, permitiendo optimizar las condiciones clínicas de trabajo y mejorar las propiedades finales del material restaurador
Aplicación de la descomposición del 2-propanol como técnica de caracterización ácido-base de catalizadores CoMo para hidrotratamiento
RESUMENCon el propósito de implementar una técnica sencilla para medir propiedades ácido-base de sólidos se analizaron las propiedades ácido-base de catalizadores CoMo soportados sobre alúmino-silicatos amorfos (ASA) con diferentes relaciones atómicas Si/(Si+Al) y sobre alúmina modificada con B. Estas propiedades fueron determinadas usando la reacción de descomposición del 2-propanol. Los resultados obtenidos se compararon y validaron con pruebas de descomposición de isopropilamina y medidas con Infrarrojo de piridina adsorbida. Se observó buena reproducibilidad y alta sensibilidad de la reacción de deshidratación del 2-propanol ante los cambios y/o modificaciones de la superficie del catalizador. Se encontró que para los catalizadores CoMo soportados en ASA, la densidad, fuerza y número de sitios ácidos totales se incrementa cuando se aumenta la relación Si/(Si+Al); este incremento se atribuye al aumento en el número de sitios ácidos de Brönsted. Por otro lado, para los catalizadores CoMo modificados con B se observó aumento en la densidad y fuerza de sitios ácidos con el aumento en la cantidad de B. Los resultados de este trabajo permiten concluir que la selectividad de la reacción de descomposición de 2-propanol es sensible a las características ácido-base de catalizadores, y los resultados obtenidos con esta técnica son reproducibles y acordes con métodos más sofisticados y costosos como infrarrojo de piridina adsorbida.Palabras clave: catalizadores CoMo, características ácido-base, descomposición de isopropilamina, adsorción de piridina. ABSTRACTThe acid-base properties of CoMo catalysts supported on amorphous alumino-silicates (ASA) with different Si/(Si+Al) atomic ratios and on alumina modified with B were determined using the 2-propanol decomposition reaction. Results were compared and validated with isopropylamine decomposition tests and with FT-IR measurements of adsorbed pyridine. A good reproducibility and high sensitivity of the 2-propanol dehydration reaction to changes and/or modifications of the catalyst surface were observed. In the case of the CoMo catalysts supported on ASA, density, strength and total active sites number increases when the Si/(Si+Al) ratio increases. This fact is attributed to an increase in the Brönsted acid sites. On the other hand, an increase in density and strength of acid sites with the increase in the B amount was observed in the case of CoMo catalysts modified with B. The results of this study support the conclusion that the selectivity in the decomposition of 2-propanol reaction is sensitive to changes in the acid-base properties showing reproducible results and comparable with the ones obtained from more expensive and sophisticated methods.Keywords: CoMo catalysts, acid-base characteristics, isopropylamine decomposition, pyridine adsorption
- …