Effects of temporal variability of disturbance on the succession in marine fouling communities in northern-central Chile

We investigated the effects of temporal variability in a disturbance regime on fouling communities at two study sites in a northern-central Chilean bay. Fouling assemblages grown on artificial settlement substrata were disturbed by mechanical removal of biomass at different time intervals. Using one single disturbance frequency (10 disturbance events over 5 months) we applied 7 different temporal disturbance treatments: a constant disturbance regime (identical intervals between disturbance events), and 6 variable treatments where both variableness and sequences of intervals between disturbance events were manipulated. Two levels of temporal variableness (low and high, i.e. disturbance events were either dispersed or highly clumped in time) in the disturbance regime were applied by modifying the time intervals between subsequent disturbance events. To investigate the temporal coupling between disturbance events and other ecological processes (e.g. larval supply and recruitment intensity), three different sequences of disturbance intervals were nested in each of the two levels of temporal variableness. Species richness, evenness, total abundance, and structure of communities that experienced the various disturbance regimes were compared at the end of the experiment (15 days after the last disturbance event). Disturbance strongly influenced the community structure and led to a decrease in evenness and total abundance but not species richness. In undisturbed reference communities, the dominant competitor Pyura chilensis (Tunicata) occupied most available space while this species was suppressed in all disturbed treatments. Surprisingly, neither temporal variableness in the disturbance regime nor the sequence of intervals between disturbance events had an effect on community structure. Temporal variability in high disturbance regimes may be of minor importance for fouling communities, because they are dominated by opportunistic species that are adapted to rapidly exploit available space

Cool dwarfs in wide multiple systems. Paper 6: A curious quintuple system of a compact Sun-like triple and a close pair of an M dwarf and a very cool white dwarf at a wide separation

The system WDS 16329+0315 is an old, nearby quintuple physical system in the thick Galactic disc formed by a close-resolved, triple primary of solar metallicity, namely HD 149162, and a very wide, common proper motion, secondary pair, formed by the mid-M dwarf G-17-23 and the white dwarf LSPM J1633+0311S. We present an exhaustive astrometric and photometric data compilation of the system, including Gaia DR2 parallaxes and proper motions, and the first analysis of the nature of the faintest component. LSPM J1633+0311S (HD 149162 C) is a very cool white dwarf with an effective temperature of only about 5500 K, near the coolest end of the grid of theoretical models.Comment: The Observatory, in press, to appear in December 201

Rearguard remix : a practice of political listening

Rearguard remix is a creative practice that aims to be a non-extractivist form of inquiry and a practice of political listening that fosters activists’ interpretations and conceptualisations of their situated political experiences. Video remix is used as a way to explore, research and create relations among diverse knowledges and political practices that resist colonial, capitalist and heteropatriarcal oppression. I consider these practices what Boaventura de Sousa Santos calls “knowledge born in struggle” (2014). These knowledges center on political, ethical and critical thinking in collective terms, and form a digital oral archive including anarchist, feminist and indigenous activist, intellectual activists/militant researchers and their collectives, mainly from Latin America. I examine the remix literature in relation to these sources and reconceptualise remix in terms of Silvia Rivera Cusicanqui’s Ch’ixi epistemology. The practice of remix works with the logic of sharing, in this case of knowledge and media productions available on the internet, by remixing these videos and offer access to the original materials. Rearguard remix is also a way to recirculate both the articulation of knowledges by remixing them and the complete media productions shared online. I also reflect on my creative process through the use of the metaphors: aphorism and memory, weaving and the weaver, ingesting, and the idea of intimacy without proximity

Effect of L-usnic acid on a thermically denatured urease.

Sin resume

Hospitalización por episodios de cianosis en recién nacidos de edad gestacional igual o mayor a 34 semanas

ResumenObjetivoCaracterizar la hospitalización por episodios de cianosis en recién nacidos (RN)>34semanas.Pacientes y métodoEstudio retrospectivo que incluyó la totalidad de los RN hospitalizados por episodios de cianosis entre enero de 2007 y diciembre de 2012. En ellos se aplicaron 2 protocolos de estudio que consideraban exámenes de primera y segunda línea; estos últimos ante la recurrencia de eventos. El protocolo de primera línea consideró exámenes bioquímicos generales, radiografía de tórax y ecocardiografía en casos seleccionados, en tanto que el protocolo de segunda línea incluyó electroencefalograma, electrocardiograma, resonancia magnética nuclear encefálica, screening metabólico ampliado, ácido pirúvico, ácido láctico y en caso de convulsiones, citoquímico y cultivo de líquido cefalorraquídeo y reacción en cadena de la polimerasa para herpes.ResultadosNoventa y ocho de un total de 3.454 (2,8%) RN hospitalizados ingresaron por episodio de cianosis. La edad gestacional (EG) fue 37,8+1,36 semanas; peso al nacimiento: 3145+477g. Edad materna: 32+4,8 años. El 19,4% de las madres tenía antecedentes mórbidos: diabetes gestacional (8,1%), síndrome hipertensivo del embarazo (5,1%), colestasia intrahepática (3,1%) y retardo del crecimiento (3,1%). Género: 48,8% masculino, parto por cesárea: 68,4%. Edad al ingreso: 1,9+1,4 días; duración de la hospitalización: 4,2+4,2 días. En todos los pacientes se practicaron exámenes de primera línea y en el 39,8% exámenes de segunda línea. En el 21,4% de los RN se identificó una causa, siendo el síndrome convulsivo el más frecuente (33%). Los RN con diagnóstico asociado presentaron 3,8+2,7 episodios de cianosis versus 1,5+2,4 en el grupo sin diagnóstico (NS). El 15,4% se fueron de alta con monitor; no hubo reingresos.ConclusiónLa incidencia de hospitalización neonatal por episodios de cianosis fue de 6 por 1.000 RN vivos. Solo en cerca de un 20% de ellos es posible identificar una causa, siendo la más frecuente el síndrome convulsivo.AbstractObjectivesA retrospective study was performed between January 2007 and December 2012 to assess the admission rates of newborns due to episodes of cyanosisPatients and methodRetrospective study that included all the newborns hospitalized with episodes of cyanosis between January 2007 and December 2012. In them were employed two study protocols that considered first and second line tests, the latter in view of recurrence of events. The first line protocol considered general biochemical tests, chest x-ray and echocardiography in selected cases, while the second line protocol included electroencephalogram, electrocardiogram, nuclear magnetic resonance of the brain, expanded metabolic screening, pyruvic acid, lactic acid, and in case of seizures, cytochemical, and culture of cerebrospinal fluid (CSF) and PCR (polymerase chain reaction) for herpes.ResultsA total of 98 (2.8%) out of 3,454 newborns were admitted due to episodes of cyanosis. Gestational age: 37.8+1.4 weeks, birth weight: 3,145+477g. Maternal age: 32+4.8 years. Disease was present in 19.4% of mothers; gestational diabetes (8.1%), pregnancy induced hypertension (5.1%), intrahepatic cholestasis (3.1%), and intrauterine growth retardation (3.1%). Gender: 48.8% male, 51.2% female (NS). Birth: caesarean section, 68.4%, and vaginal delivery, 31.6%. Age on admission 1.9+1.4 days. Hospital stay: 4.2+4.2 days. First line tests were performed in 100% of patients with 39.8% fulfilling the criteria for second line study. A condition was detected in 21.4%, with convulsive syndrome was the most frequent (33%). Newborns with an identified condition had 3.8+2.7episodes versus 1.5+2,4 in those without diagnosis (NS). A home oxygen monitor was given to 15.4%. There were no re-admissions.ConclusionsMost newborns admitted due to cyanosis are discharged with a condition of unknown origin. In this study, convulsive syndrome was the most frequent cause

Screening for lignin peroxidase genes in natural isolates of white rot fungi

To find lingin peroxidase genes similar to those of Phanerochaete chrysosporium, we have studied several species of white rot fungi collected in nature. The methodology has been DNA hybridization techniques using two synthetic oligonucleotides with a sequence that corresponds to a fragment of the H8 lignin peroxidase gene from P. chrysosporium (Schalch et al. 1989. Mol. Cell. Biol. 9:2743-2747) controlling the structure of the predominant form of the enzyme in this fungus

Local entrainment velocity in a premixed turbulent annular jet flame

The local entrainment velocity of the enstrophy interfaces of a methane-air turbulent premixed turbulent annular jet flame stabilized on a bluff-body burner has been investigated using a high-fidelity flame-resolved three-dimensional simulation. The enstrophy (inner and outer) and the scalar interfaces have been defined and characterized by their propagation speeds, VE and Sd , relative to the fluid flow. Mean values ( and ) conditioned on the reaction progress variable c have been obtained. A thin layer (near the enstrophy interfaces) has been used to compute mean values (, , and its different contributions) conditional upon enstrophy E. At the inner interface, results indicate that . Sd |. E> > 0 (entrainment of fresh reactants into the flame front and hot products), while < 0 and < 0 (entrainment of hot products into the reacting jet across the inner enstrophy interface). The outer enstrophy interface displays > 0 (ambient gases are predominantly entrained into the jet of reactants), which implies a lean mixture in its neighborhood. These preliminary results aim at understanding the physical mechanisms of flame anchoring, in terms of entrainments of either hot products or fresh reactants into the diffusive-reactive region. Local geometries of the inner and outer interfaces have also been examined, through the computation of joint probability density functions of the mean curvature km and Gauss curvature kg of the iso-enstrophy surfaces, and through |. km, kg at the inner and outer interfaces. This information has subsequently been used to discuss the physics of how the turbulent entrainment process affects premixed flames

RELIABILITY OF LOW-COST PORTABLE FORCE PLATFORMS FOR MEASURING VERTICAL STIFFNESS DURING RUNNING

Ground reaction force (GRF) can provide useful information such as vertical stiffness (Kvert) to practitioners working with runners and sprinters, but high equipment costs are hindering applied research. Low-cost portable force platforms may be a useful alternative to traditional biomechanical equipment. Moderately trained runners (n = 9) completed overground running trials at various speeds (2.15-5.78 m/s), Kvert was determined, and a linear regression was used to characterize the relationship between Kvert and running speed. The results showed moderate to high correlation (r2 = 0.54 to 0.87). At 3.9 m/s (14 km/h), the widest regression model confidence interval was 4.4%, which shows this procedure likely provides adequate reliability. Future research should continue to investigate the use of low-cost portable force platforms for measuring running GRF

A method for the preparation of intact chromosomal DNA of Pycnoporus cinnabarinus

We describe an improved procedure to obtain chromosomal DNA of Pycnoporus cinnabarinus, which was used in pulse field gel electrophoresis employing a contour-clamped homogenous electric field (CHEF). Four bands of chromosomal DNA were separated. The procedure may be useful to study the genome of other filamentous fungi

Presence of double stranded RNA in natural isolates of Pycnoporus cinnabarinus

While studying the nucleic acids of different strains of P. cinnabarinus (Pc58, Pc470.3, Pc470.6), the presence of dsRNA molecules (1.7 kb to 3.6 kb) was detected in two of them