2006-2007 explosive activity and erupted products of Ubinas volcano (Peru)

[ENG] Ubinas, the most historically active volcano in southern Peru, has shown 24 degassing and ashfall episodes since A.D.1550. A population of ~3500 is living within 12 km of Ubinas and has been periodically affected by ash fall and gas. The most recent explosive activity started on 27 March 2006, while degassing still continues. Based on the erupted products and the explosive behaviour, the eruptive episode has shown four stages: 1) the initial phreatic and phreatomagmatic activity (27 March to ~19 April 2006), which included eruption columns that spread ashfall as far as 7 km from the summit; 2) vulcanian explosions (~20 April to 11 June 2006) forming 3 to 4 km-high columns, from which blocks up to 40 cm in diameter were ejected to distances 2 km from the vent; fresh lava reached the vent bottom on 20 April; 3) strong degassing was interspersed with at least 12 events (mid June 2006 - April 2007) that produced 2-3 kmhigh vulcanian columns and ashfall as far as 40 km from the summit; 4) mild degassing since May 2007 produces a permanent 200 to 800 m-high plume and occasional light ashfall around the summit. Erupted ash fallout, ballistic scoriae and crust bombs represent an estimated volume of ~106 m3, while fresh lava of unknown volume has been emplaced at the bottom of the vent 200 m below the summit caldera floor. The composition of the ejecta is 56-57% SiO2 and 6.16-6.30% K2O+Na2O, and is similar to the average composition of historically erupted andesite at Ubinas. Petrographic textures and the chemical zoning pattern of phenocrysts show dusty-rimmed plagioclase with reverse zonations (An33-56 cores, An41-59 rims), clinopyroxene with reverse zonations (Mg#71cores, Mg#73 rims), amphibole with reaction rims, and olivine xenocrysts. This indicates that part of the mineral assemblage is not in equilibrium with the average mineral suite or with the melt, a process that may have occurred prior to, or during, the 2006 eruptive activity. Such characteristics suggest a recharge of “fresh” erupted andesite and another ‘old’ andesite bearing a mineral assemblage inherited from a previous magma batch within the conduit

Can inhaled cannabis users accurately evaluate impaired driving ability? A randomized controlled trial

AimsTo study the effect of inhaled cannabis on self-assessed predicted driving ability and its relation to reaction times and driving ability on a driving simulator.Participants and methods30 healthy male volunteers aged 18–34: 15 chronic (1–2 joints /day) and 15 occasional (1–2 joints/week) consumers. Self-assessed driving confidence (visual analog scale), vigilance (Karolinska), reaction time (mean reciprocal reaction time mRRT, psychomotor vigilance test), driving ability (standard deviation of lane position SDLP on a York driving simulator) and blood concentrations of delta-9-tétrahydrocannabinol (THC) were measured before and repeatedly after controlled inhalation of placebo, 10 mg or 30 mg of THC mixed with tobacco in a cigarette.ResultsCannabis consumption (at 10 and 30 mg) led to a marked decrease in driving confidence over the first 2 h which remained below baseline at 8 h. Driving confidence was related to THC dose and to THC concentrations in the effective compartment with a low concentration of 0.11 ng/ml for the EC50 and a rapid onset of action (T1/2 37 min). Driving ability and reaction times were reduced by cannabis consumption. Driving confidence was shown to be related to driving ability and reaction times in both chronic and occasional consumers.ConclusionsCannabis consumption leads to a rapid reduction in driving confidence which is related to reduced ability on a driving simulator.Clinical trial registrationClinicalTrials.gov, identifier: NCT02061020

N=2 supersymmetry breaking at two different scales

We study N=2 spontaneous supersymmetry breaking at two different scales with matter fields in hypermultiplets charged under the gauge group that should involve at least two U(1) factors. Off-shell analysis is possible in the dual single-tensor formulation of the hypermultiplets. Massless fermions can naturally arise from pseudo-real representations of the gauge group that allow a reformulation of the problem of chirality in N=2 theories. The above properties are necessary ingredients towards constructing viable extensions of the Standard Model based on N=2 supersymmetry.Comment: 26 page

The relationship between uremic toxins and symptoms in older men and women with advanced chronic kidney disease

Background: Patients with stage 4/5 chronic kidney disease (CKD) suffer from various symptoms. The retention of uremic solutes is thought to be associated with those symptoms. However, there are relatively few rigorous studies on the potential links between uremic toxins and symptoms in patients with CKD. Methods: The EQUAL study is an ongoing observational cohort study of non-dialyzed patients with stage 4/5 CKD. EQUAL patients from Germany, Poland, Sweden and the UK were included in the present study (n = 795). Data and symptom self-report questionnaires were collected between April 2012 and September 2020. Baseline uric acid and parathyroid hormone and 10 uremic toxins were quantified. We tested the association between uremic toxins and symptoms and adjusted P-values for multiple testing. Results: Symptoms were more frequent in women than in men with stage 4/5 CKD, while levels of various uremic toxins were higher in men. Only trimethylamine N-oxide (TMAO; positive association with fatigue), p-cresyl sulfate (PCS) with constipation and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (negative association with shortness of breath) demonstrated moderately strong associations with symptoms in adjusted analyses. The association of phenylacetylglutamine with shortness of breath was consistent in both sexes, although it only reached statistical significance in the full population. In contrast, TMAO (fatigue) and PCS and phenylacetylglutamine (constipation) were only associated with symptoms in men, who presented higher serum levels than women. Conclusion: Only a limited number of toxins were associated with symptoms in persons with stage 4/5 CKD. Other uremic toxins, uremia-related factors or psychosocial factors not yet explored might contribute to symptom burden.</p

The relationship between uremic toxins and symptoms in older men and women with advanced chronic kidney disease

Background: Patients with stage 4/5 chronic kidney disease (CKD) suffer from various symptoms. The retention of uremic solutes is thought to be associated with those symptoms. However, there are relatively few rigorous studies on the potential links between uremic toxins and symptoms in patients with CKD. Methods: The EQUAL study is an ongoing observational cohort study of non-dialyzed patients with stage 4/5 CKD. EQUAL patients from Germany, Poland, Sweden and the UK were included in the present study (n = 795). Data and symptom self-report questionnaires were collected between April 2012 and September 2020. Baseline uric acid and parathyroid hormone and 10 uremic toxins were quantified. We tested the association between uremic toxins and symptoms and adjusted P-values for multiple testing. Results: Symptoms were more frequent in women than in men with stage 4/5 CKD, while levels of various uremic toxins were higher in men. Only trimethylamine N-oxide (TMAO; positive association with fatigue), p-cresyl sulfate (PCS) with constipation and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (negative association with shortness of breath) demonstrated moderately strong associations with symptoms in adjusted analyses. The association of phenylacetylglutamine with shortness of breath was consistent in both sexes, although it only reached statistical significance in the full population. In contrast, TMAO (fatigue) and PCS and phenylacetylglutamine (constipation) were only associated with symptoms in men, who presented higher serum levels than women. Conclusion: Only a limited number of toxins were associated with symptoms in persons with stage 4/5 CKD. Other uremic toxins, uremia-related factors or psychosocial factors not yet explored might contribute to symptom burden.</p

Crisis eruptiva del volcán Ubinas, periodo 2006-2008

La crisis eruptiva del volcán Ubinas se inició el 27 de marzo del año 2006 (Mariño, et al., 2006). Durante el proceso eruptivo se han identificado dos regímenes eruptivos diferentes: a) régimen freático, que se extiende del 27 de marzo al 18 de abril del 2006, caracterizado por emisiones de cenizas y proyectiles balísticos con un alto porcentaje de componentes hidrotermalizados; b) régimen eruptivo magmático de tipo vulcaniano, que se inicia alrededor del 19 de abril del año 2006, fecha en que se avistó por primera vez un cuerpo de lava incandescente en el fondo del cráter, corroborado también por el alto contenido de componentes juveniles en las cenizas emitidas posteriores al 20 de abril. En este segundo régimen se ha identificado una etapa de mayor actividad eruptiva, entre el 19 de abril y 31 de agosto del 2006; y una etapa de menor actividad, entre el 01 de setiembre del 2006 y diciembre del año 2009. En la etapa de mayor actividad, la columna eruptiva alcanzó valores de altura máximos, entre los 1500 y 2500 m sobre la caldera del volcán Ubinas, sin embargo luego de algunas explosiones estas se elevaron incluso entre los 3000 a 4000 m de altura. En esta etapa se produjeron en promedio una explosión cada dos días. En la etapa de menor actividad, en promedio la pluma volcánica alcanzó entre 300 y 700 m de altura sobre la cumbre. Fueron interrumpidas por explosiones de baja energía, luego del cual se formaron columnas que se elevaron entre 500 y 1500 m de altura sobre la caldera y muy esporádicamente sobre los 2500 m. Las explosiones ocurrieron en promedio una vez cada 20 a 30 días. Durante la etapa de mayor actividad eruptiva, el Índice de Explosividad Volcánica (IEV) estimada fue 1. Los productos emitidos por el volcán Ubinas son cenizas y proyectiles balísticos. Las cenizas afectaron hasta un radio de 12 km alrededor del volcán, sin embargo en las imágenes de satélite fueron avistadas hasta 100 a 120 km de distancia. Los proyectiles balísticos juveniles emitidos, poseen composición andesítica basáltica, contienen fenocristales de plagioclasas (algunas zonadas), piroxenos, óxidos y xenocristales de biotita (Rivera, et al., 2007). El alcance máximo registrado de los proyectiles balísticos es de 1.8 km, donde poseen hasta 1,5 cm de diámetro. Durante los años 2005 y 2006, en la fuente UBT, los valores del anión SO4 2- fluctuaron entre 400 y 1050 mg/L, pero a partir de enero del 2007 hasta todo el 2008, dichos valores se incrementaron ligeramente y fluctuaron entre 1000 y 1240 mg/L. En el caso del anión Cl, este se incrementó ligeramente entre enero y marzo del año 2006, sus valores se ubicaron entre 340 y 380 mg/L. Así mismo, se han observado las mayores variaciones en los valores de los cationes Na, Ca y K, entre fines de marzo y los primeros días de agosto del año 2006. En esta misma fuente termal, los mayores valores de pH se registraron durante el mes de junio del año 2006 (entre 6.5 y 7) y la temperatura se incrementó nítidamente entre abril y agosto del mismo año (entre 30 y 42.5 ºC). El mayor impacto ambiental generado por la erupción, fue debido a la caída de cenizas, principalmente en las localidades de Querapi, Ubinas, Tonohaya, Sacoaya y Escacha. Estas provocaron problemas de salud en las personas, tales como dermatitis, conjuntivitis y afecciones estomacales; también originaron la pérdida de productos de pan llevar, tales como papas, maíz, trigo, cebada, habas y alfalfa, principalmente el año 2006, así como muerte de camélidos, ovinos, ganado vacuno y caprino, por la ingesta de pastos contaminados con ceniza

Crisis eruptiva del volcán Ubinas, periodo 2006-2008

El volcán Ubinas se encuentra localizado a 90 km al norte y 65 km al este de las ciudades de Moquegua y Arequipa respectivamente (16º 22' S, 70º 54' O; 5,672 msnm. El cono volcánico se localiza en jurisdicción de la Región Moquegua y según datos de un censo realizado durante el inicio del proceso eruptivo 2006, cerca al volcán viven alrededor de 1,216 familias y 3,559 habitantes, en 19 centros poblados. Los pobladores de Querapi reportaron caídas de ceniza en su localidad el día 27 de marzo del año 2006 (Mariño et al., 2006). Este hecho evidenció la carencia de un sistema de monitoreo continuo en el volcán Ubinas y la imperiosa necesidad de implementarla. El día 31 de marzo del año 2006, representantes del INGEMMET, IGP, UNSA, INDECI-Moquegua, Municipalidad Distrital de Ubinas y del CRDC-Moquegua, realizamos una inspección de campo al volcán Ubinas. Este trabajo permitió corroborar que efectivamente el volcán Ubinas había entrado en una nueva fase eruptiva