761 research outputs found

    Diel transcriptional response of a California Current plankton microbiome to light, low iron, and enduring viral infection

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    Phytoplankton and associated microbial communities provide organic carbon to oceanic food webs and drive ecosystem dynamics. However, capturing those dynamics is challenging. Here, an in situ, semi-Lagrangian, robotic sampler profiled pelagic microbes at 4 h intervals over ~2.6 days in North Pacific high-nutrient, low-chlorophyll waters. We report on the community structure and transcriptional dynamics of microbes in an operationally large size class (>5 μm) predominantly populated by dinoflagellates, ciliates, haptophytes, pelagophytes, diatoms, cyanobacteria (chiefly Synechococcus), prasinophytes (chiefly Ostreococcus), fungi, archaea, and proteobacteria. Apart from fungi and archaea, all groups exhibited 24-h periodicity in some transcripts, but larger portions of the transcriptome oscillated in phototrophs. Periodic photosynthesis-related transcripts exhibited a temporal cascade across the morning hours, conserved across diverse phototrophic lineages. Pronounced silica:nitrate drawdown, a high flavodoxin to ferredoxin transcript ratio, and elevated expression of other Fe-stress markers indicated Fe-limitation. Fe-stress markers peaked during a photoperiodically adaptive time window that could modulate phytoplankton response to seasonal Fe-limitation. Remarkably, we observed viruses that infect the majority of abundant taxa, often with total transcriptional activity synchronized with putative hosts. Taken together, these data reveal a microbial plankton community that is shaped by recycled production and tightly controlled by Fe-limitation and viral activity

    Development and Psychometric Properties of an Assessment for Persons With Intellectual Disability—The interRAI ID

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    This paper describes the development of the interRAI-Intellectual Disability (interRAI ID), a comprehensive instrument that assesses all key domains of interest to service providers relative to a person with an intellectual disability (ID). The authors report on the reliability and validity of embedded scales for cognition, self-care, aggression, and depression. Four provider agencies volunteered to participate and assessed a total of 160 community-dwelling adults with ID using the interRAI ID, Dementia Questionnaire for Persons with Mental Retardation, and Reiss Screen for Maladaptive Behavior. All scales had acceptable levels of internal consistency (Cronbach’s alpha 0.74–0.93) and good relationships with the criterion measures ( r  = 0.50–0.93, p  < 0.0001). The development of the interRAI ID represents an important and successful first step toward an integrated, comprehensive, and standardized assessment of adults with ID. Use of this instrument may lead to more appropriate support planning, enhanced communication between various professionals supporting persons with ID, and a more seamless approach to supports across the health and social service systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75618/1/j.1741-1130.2006.00094.x.pd

    Determination of the basin of attraction of a periodic orbit in two dimensions using meshless collocation

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    A contraction metric for an autonomous ordinary differential equation is a Riemannian metric such that the distance between adjacent solutions contracts over time. A contraction metric can be used to determine the basin of attraction of a periodic orbit without requiring information about its position or stability. Moreover, it is robust to small perturbations of the system. In two-dimensional systems, a contraction metric can be characterised by a scalar-valued function. In [9], the function was constructed as solution of a first-order linear Partial Differential Equation (PDE), and numerically constructed using meshless collocation. However, information about the periodic orbit was required, which needed to be approximated. In this paper, we overcome this requirement by studying a second-order PDE, which does not require any information about the periodic orbit. We show that the second-order PDE has a solution, which defines a contraction metric. We use meshless collocation to approximate the solution and prove error estimates. In particular, we show that the approximation itself is a contraction metric, if the collocation points are dense enough. The method is applied to two examples

    Super Earth Explorer: A Coronagraphic Off-Axis Space Telescope

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    The Super-Earth Explorer is an Off-Axis Space Telescope (SEE-COAST) designed for high contrast imaging. Its scientific objective is to make the physico-chemical characterization of exoplanets possibly down to 2 Earth radii >. For that purpose it will analyze the spectral and polarimetric properties of the parent starlight reflected by the planets, in the wavelength range 400-1250 nmComment: Accepted in Experimental Astronom

    Facial emotion recognition in Williams syndrome and Down syndrome: A matching and developmental study

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    In this study both the matching and developmental trajectories approaches were used to clarify questions that remain open in the literature on facial emotion recognition in Williams syndrome (WS) and Down syndrome (DS). The matching approach showed that individuals with WS or DS exhibit neither proficiency for the expression of happiness nor specific impairments for negative emotions. Instead, they present the same pattern of emotion recognition as typically developing (TD) individuals. Thus, the better performance on the recognition of positive compared to negative emotions usually reported in WS and DS is not specific of these populations but seems to represent a typical pattern. Prior studies based on the matching approach suggested that the development of facial emotion recognition is delayed in WS and atypical in DS. Nevertheless, and even though performance levels were lower in DS than in WS, the developmental trajectories approach used in this study evidenced that not only individuals with DS but also those with WS present atypical development in facial emotion recognition. Unlike in the TD participants, where developmental changes were observed along with age, in the WS and DS groups, the development of facial emotion recognition was static. Both individuals with WS and those with DS reached an early maximum developmental level due to cognitive constraints
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