443 research outputs found
Spatial and temporal variability of groundwater recharge in a sandstone aquifer in a semiarid region
With the aim to understand the spatial and temporal variability of
groundwater recharge, a high-resolution, spatially distributed numerical
model (MIKE SHE) representing surface water and groundwater was used to
simulate responses to precipitation in a 2.16 km2 upland catchment on
fractured sandstone near Los Angeles, California. Exceptionally high
temporal and spatial resolution was used for this catchment modeling: hourly
climate data, a 20 m×20 m grid in the horizontal plane, and 240 numerical
layers distributed vertically within the thick vadose zone and in the upper
part of the groundwater zone. The finest practical spatial and temporal
resolutions were selected to accommodate the large degree of surface and
subsurface variability of catchment features. Physical property values for
the different lithologies were assigned based on previous on-site
investigations, whereas the parameters controlling streamflow and
evapotranspiration were derived from calibration to continuous streamflow at
the outfall and to average hydraulic heads from 17 wells. Confidence in the
calibrated model was enhanced by validation through (i) comparison of
simulated average recharge to estimates based on the applications of the
chloride mass-balance method to data from the groundwater and vadose zones
within and beyond the catchment, (ii) comparison of the water isotope
signature (18O and 2H) in shallow groundwater to the variability
of isotope signatures for precipitation events over an annual cycle, and
(iii) comparison of simulated recharge time series and observed fluctuation
of water levels. The average simulated recharge across the catchment for the
period 1995–2014 is 16 mm yr−1 (4 % of the average annual
precipitation), which is consistent with previous estimates obtained by
using the chloride mass balance method (4.2 % of the average
precipitation). However, one of the most unexpected results was that local
recharge was simulated to vary from 0 to >1000 mm yr−1 due
to episodic precipitation and overland runoff effects. This recharge occurs
episodically with the major flux events at the bottom of the
evapotranspiration zone, as simulated by MIKE SHE and confirmed by the
isotope signatures, occurring only at the end of the rainy season. This is
the first study that combines MIKE SHE simulations with the analysis of
water isotopes in groundwater and rainfall to determine the timing of
recharge in a sedimentary bedrock aquifer in a semiarid region. The study
advances the understanding of recharge and unsaturated flow processes and
enhances our ability to predict the effects of surface and subsurface
features on recharge rates. This is crucial in highly heterogeneous
contaminated sites because different contaminant source areas have widely
varying recharge and, hence, groundwater fluxes impacting their mobility.</p
Neuroblastoma Formation Requires Unconventional CD4 T Cells and Arginase-1-Dependent Myeloid Cells
Immune cells regulate tumor growth by mirroring their function as tissue repair organizers in normal tissues. To understand the different facets of immune-tumor collaboration through genetics, spatial transcriptomics, and immunologic manipulation with noninvasive, longitudinal imaging, we generated a penetrant double oncogene-driven autochthonous model of neuroblastoma. Spatial transcriptomic analysis showed that CD4(+) and myeloid populations colocalized within the tumor parenchyma, while CD8(+) T cells and B cells were peripherally dispersed. Depletion of CD4(+) T cells or CCR2(+) macrophages, but not B cells, CD8(+) T cells, or natural killer (NK) cells, prevented tumor formation. Tumor CD4(+) T cells displayed unconventional phenotypes and were clonotypically diverse and antigen independent. Within the myeloid fraction, tumor growth required myeloid cells expressing arginase-1. Overall, these results demonstrate how arginine-metabolizing myeloid cells conspire with pathogenic CD4(+) T cells to create permissive conditions for tumor formation, suggesting that these protumorigenic pathways could be disabled by targeting myeloid arginine metabolism. Significance: A new model of human neuroblastoma provides ways to track tumor formation and expansion in living animals, allowing identification of CD4(+) T-cell and macrophage functions required for oncogenesis. [GRAPHICS
Fluent Speech Via Visual Choral Speech
A novel phenomenon of fluency enhancement via visual gestures of speech in the absence of traditional auditory feedback is reported herein. The effect on visual choral speech on stuttering frequency was investigated. Ten participants who stuttered recited memorized text aloud under two conditions. In a Visual Choral Speech (VCS) condition participants were instructed to focus their gaze on the face, lips and jaw of a research assistant who "silently mouthed" the text in unison. In a control condition, participants recited memorized text to the research assistant who sat motionless. A statistically significant (p= .0025) reduction of approximately 80% in stuttering frequency was observed in the VCS condition. As visual linguistic cues are sufficient to activate the auditory cortex, one may speculate that VCS induces fluency in a similar yet undetermined manner as altered auditory feedback does
Global Analysis of RNA Secondary Structure in Two Metazoans
The secondary structure of RNA is necessary for its maturation, regulation, processing, and function. However, the global influence of RNA folding in eukaryotes is still unclear. Here, we use a high-throughput, sequencing-based, structure-mapping approach to identify the paired (double-stranded RNA [dsRNA]) and unpaired (single-stranded RNA [ssRNA]) components of the Drosophila melanogaster and Caenorhabditis elegans transcriptomes, which allows us to identify conserved features of RNA secondary structure in metazoans. From this analysis, we find that ssRNAs and dsRNAs are significantly correlated with specific epigenetic modifications. Additionally, we find key structural patterns across protein-coding transcripts that indicate that RNA folding demarcates regions of protein translation and likely affects microRNA-mediated regulation of mRNAs in animals. Finally, we identify and characterize 546 mRNAs whose folding pattern is significantly correlated between these metazoans, suggesting that their structure has some function. Overall, our findings provide a global assessment of RNA folding in animals
Confocal microscopy of colloidal particles: towards reliable, optimum coordinates
Over the last decade, the light microscope has become increasingly useful as
a quantitative tool for studying colloidal systems. The ability to obtain
particle coordinates in bulk samples from micrographs is particularly
appealing. In this paper we review and extend methods for optimal image
formation of colloidal samples, which is vital for particle coordinates of the
highest accuracy, and for extracting the most reliable coordinates from these
images. We discuss in depth the accuracy of the coordinates, which is sensitive
to the details of the colloidal system and the imaging system. Moreover, this
accuracy can vary between particles, particularly in dense systems. We
introduce a previously unreported error estimate and use it to develop an
iterative method for finding particle coordinates. This individual-particle
accuracy assessment also allows comparison between particle locations obtained
from different experiments. Though aimed primarily at confocal microscopy
studies of colloidal systems, the methods outlined here should transfer readily
to many other feature extraction problems, especially where features may
overlap one another.Comment: Accepted by Advances in Colloid and Interface Scienc
Questioning short-term memory and its measurement: why digit span measures long-term associative learning
Traditional accounts of verbal short-term memory explain differences in performance for different types of verbal material by reference to inherent characteristics of the verbal items making up memory sequences. The role of previous experience with sequences of different types is ostensibly controlled for either by deliberate exclusion or by presenting multiple trials constructed from different random permutations
Hackable Instruments: Supporting Appropriation and Modification in Digital Musical Interaction
This paper investigates the appropriation of digital musical instruments, wherein the performer develops a personal working relationship with an instrument that may differ from the designer's intent. Two studies are presented which explore different facets of appropriation. First, a highly restrictive instrument was designed to assess the effects of constraint on unexpected creative use. Second, a digital instrument was created which initially shared several constraints and interaction modalities with the first instrument, but which could be rewired by the performer to discover sounds not directly anticipated by the designers. Each instrument was studied with 10 musicians working individually to prepare public performances on the instrument. The results suggest that constrained musical interactions can promote the discovery of unusual and idiosyncratic playing techniques, and that tighter constraints may paradoxically lead to a richer performer experience. The diversity of ways in which the rewirable instrument was modified and used indicates that its design is open to interpretation by the performer, who may discover interaction modalities that were not anticipated by the designers
Addressing our planetary crisis: Consensus statement from the presenters and International Advisory Committee of the Regional Action on Climate Change (RACC) Symposium held in conjunction with the Kyoto-based Science and Technology in Society (STS) Forum, 1 October 2021.
12 month embargo; published: 01 November 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Changing practice in dementia care in the community: developing and testing evidence-based interventions, from timely diagnosis to end of life (EVIDEM)
Background
Dementia has an enormous impact on the lives of individuals and families, and on health and social services, and this will increase as the population ages. The needs of people with dementia and their carers for information and support are inadequately addressed at all key points in the illness trajectory.
Methods
The Unit is working specifically on an evaluation of the impact of the Mental Capacity Act 2005, and will develop practice guidance to enhance concordance with the Act. Phase One of the study has involved baseline interviews with practitioners across a wide range of services to establish knowledge and expectations of the Act, and to consider change processes when new policy and legislation are implemented.
Findings
Phase 1, involving baseline interviews with 115 practitioners, identified variable knowledge and understanding about the principles of the Act. Phase 2 is exploring everyday decision-making by people with memory problems and their carers
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