1,924 research outputs found
Contrasting physical and chemical conditions of two rock glacier springs
9openInternationalBothRock glaciers are increasingly influencing the hydrology and water chemistry of Alpine catchments. During three consecutive summers (2017–2019), we monitored by recording probes and fortnightly/monthly field campaigns the physical and chemical conditions of two rock glacier springs (ZRG, SRG) in the Zay and Solda/Sulden catchments (Eastern Italian Alps). The springs have contrasting hydrological conditions with ZRG emerging with evident ponding (pond-like), and SRG being a typical high-elevation seep (stream-like). Water temperature was constantly low (mean 1.2°C, standard deviation 0.1°C) at both springs. Concentrations of major ions (dominated by SO42−, HCO3−, Ca2+ and Mg2+) and trace elements (As, Sr, Ba, U, Rb) increased, and water became more enriched in heavy stable isotopes (δ18O, δ2H) towards autumn. This solute and isotopic enrichment had an asymptotic trend at SRG, and a unimodal pattern at ZRG, where peaks occurred 60–80 days after the snowmelt end. Wavelet analysis of electrical conductivity (EC) and water temperature records revealed daily cycles only at SRG, and significant weekly/biweekly fluctuations at both springs attributable to oscillations of meteorological conditions. Several rainfall events triggered a transient (0.5–2 h) EC drop (of 5–240 μS cm−1) and water temperature rise (of 0.2–1.4°C) at SRG (dilution and warming), whereas only intense rainfall events occasionally increased EC (by 15–85 μS cm−1) at ZRG (solute enrichment and thermal buffering), with a long-lasting effect (6–48 h). Building on previous research, we suggest that rock glacier springs with differing flow conditions, that is, stream-like and pond-like, have contrasting fluctuations of water parameters at different timescales. Thus, for pond-like springs, peaks of EC/solute concentrations might indicate a seasonal window of major permafrost thaw. Our quantitative description of the hydrochemical seasonality in rock glacier outflows and the physical and chemical response to precipitation events provides relevant information for water management in mountain areas under climate change.openBrighenti, Stefano; Engel, Michael; Tolotti, Monica; Bruno, Maria Cristina; Wharton, Geraldene; Comiti, Francesco; Tirler, Werner; Cerasino, Leonardo; Bertoldi, WalterBrighenti, S.; Engel, M.; Tolotti, M.; Bruno, M.C.; Wharton, G.; Comiti, F.; Tirler, W.; Cerasino, L.; Bertoldi, W
A Full Shell Model Study of a~=~48 Nuclei
Exact diagonalizations with a minimally modified realistic force lead to
detailed agreement with measured level schemes and electromagnetic transitions
in Ca, Sc, Ti, V, Cr and Mn.
Gamow-Teller strength functions are systematically calculated and reproduce the
data to within the standard quenching factor. Their fine structure indicates
that fragmentation makes much strength unobservable. As a by-product, the
calculations suggest a microscopic description of the onset of rotational
motion. The spectroscopic quality of the results provides strong arguments in
favour of the general validity of monopole corrected realistic forces, which is
discussed.Comment: 30 pages, LaTeX with epsf.sty, 14 Postscript figures included and
compressed using uufiles. Completely new version of previous preprint
nucl-th/9307001. FTUAM-93/01, CRN/PT 93-3
Testing in the incremental design and development of complex products
Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested
Altered thymic differentiation and modulation of arthritis by invariant NKT cells expressing mutant ZAP70
Various subsets of invariant natural killer T (iNKT) cells with different cytokine productions develop in the mouse thymus, but the factors driving their differentiation remain unclear. Here we show that hypomorphic alleles of Zap70 or chemical inhibition of Zap70 catalysis leads to an increase of IFN-gamma-producing iNKT cells (NKT1 cells), suggesting that NKT1 cells may require a lower TCR signal threshold. Zap70 mutant mice develop IL-17-dependent arthritis. In a mouse experimental arthritis model, NKT17 cells are increased as the disease progresses, while NKT1 numbers negatively correlates with disease severity, with this protective effect of NKT1 linked to their IFN-gamma expression. NKT1 cells are also present in the synovial fluid of arthritis patients. Our data therefore suggest that TCR signal strength during thymic differentiation may influence not only IFN-gamma production, but also the protective function of iNKT cells in arthritis
Absence of Scaling in the Integer Quantum Hall Effect
We have studied the conductivity peak in the transition region between the
two lowest integer Quantum Hall states using transmission measurements of edge
magnetoplasmons. The width of the transition region is found to increase
linearly with frequency but remains finite when extrapolated to zero frequency
and temperature. Contrary to prevalent theoretical pictures, our data does not
show the scaling characteristics of critical phenomena.These results suggest
that a different mechanism governs the transition in our experiment.Comment: Minor changes and new references include
The spiritual dimension of parenting a child with a life-limiting or life-threatening condition: A mixed-methods systematic review
Background: Spirituality refers to the dynamic dimension of human life that relates to the way that persons experience meaning, purpose, and transcendence. The complex task of parenting a child with a life-limiting condition may raise existential questions, which are easily overlooked by healthcare professionals. Aim: We explored how the spiritual dimension becomes manifest in parents of children in pediatric palliative care. Design: A mixed-methods systematic review was conducted, registered in Prospero (2021 CRD42021285318). Data sources: PubMed, CINAHL, Embase, PsycInfo and Cochrane were searched for articles published between January 1, 2015 and January 1, 2023. We included original empirical studies that reported on spirituality of parents of seriously ill children, from parents’ perspectives. Results: Sixty-three studies were included: 22 North-American, 19 Asian, 13 European, 9 other. Studies varied in defining spirituality. We identified five different aspects of spirituality: religion, hope, parental identity, personal development, and feeling connected with others. All aspects could function as source of spirituality or cause of spiritual concern. Sources of spirituality helped parents to give meaning to their experiences and made them feel supported. However, parents also reported struggling with spiritual concerns. Several parents highlighted their need for professional support. Conclusions: Although studies vary in defining spirituality, reports on spirituality focus on how parents connect to their faith, others, and themselves as parents. Healthcare professionals can support parents by paying attention to the spiritual process parents are going through. More research is needed into how healthcare professionals can support parents of seriously ill children in this process
Barriers to the spiritual care of parents taking care of their child with a life-limiting condition at home
The changes that parents face when caring for a child with a life-limiting condition at home can affect them on a spiritual level. Yet, indications remain that parents do not feel supported when dealing with spiritual issues related to caring for a severely ill child. This paper explores, from the perspectives of bereaved parents, chaplains, grief counselors, and primary health care providers, the barriers to supporting the spiritual needs of parents. We conducted a qualitative focus group study from a constructivist point with chaplains/grief counselors, primary care professionals, and bereaved parents. All groups participated in two consecutive focus group sessions. Data were thematically analyzed. Six chaplains/grief counselors, 6 care professionals, and 5 parents participated. We identified six barriers: (1) There were difficulties in identifying and communicating spiritual care needs. (2) The action-oriented approach to health care hinders the identification of spiritual care needs. (3) There is an existing prejudice that spiritual care needs are by nature confrontational or difficult to address. (4) Spiritual support is not structurally embedded in palliative care. (5) There is a lack of knowledge and misconceptions about existing support. (6) Seeking out spiritual support is seen as too demanding. Conclusion:Â Parents of children with life-limiting conditions face existential challenges. However, care needs are often not identified, and existing support is not recognized as such. The main challenge is to provide care professionals and parents with the tools and terminology that suit existing care needs. (Table presented.)
Neutrinoless double beta decay in seesaw models
We study the general phenomenology of neutrinoless double beta decay in
seesaw models. In particular, we focus on the dependence of the neutrinoless
double beta decay rate on the mass of the extra states introduced to account
for the Majorana masses of light neutrinos. For this purpose, we compute the
nuclear matrix elements as functions of the mass of the mediating fermions and
estimate the associated uncertainties. We then discuss what can be inferred on
the seesaw model parameters in the different mass regimes and clarify how the
contribution of the light neutrinos should always be taken into account when
deriving bounds on the extra parameters. Conversely, the extra states can also
have a significant impact, cancelling the Standard Model neutrino contribution
for masses lighter than the nuclear scale and leading to vanishing neutrinoless
double beta decay amplitudes even if neutrinos are Majorana particles. We also
discuss how seesaw models could reconcile large rates of neutrinoless double
beta decay with more stringent cosmological bounds on neutrino masses.Comment: 34 pages, 5 eps figures and 1 axodraw figure. Final version published
in JHEP. NME results available in Appendi
Ab initio atomistic thermodynamics and statistical mechanics of surface properties and functions
Previous and present "academic" research aiming at atomic scale understanding
is mainly concerned with the study of individual molecular processes possibly
underlying materials science applications. Appealing properties of an
individual process are then frequently discussed in terms of their direct
importance for the envisioned material function, or reciprocally, the function
of materials is somehow believed to be understandable by essentially one
prominent elementary process only. What is often overlooked in this approach is
that in macroscopic systems of technological relevance typically a large number
of distinct atomic scale processes take place. Which of them are decisive for
observable system properties and functions is then not only determined by the
detailed individual properties of each process alone, but in many, if not most
cases also the interplay of all processes, i.e. how they act together, plays a
crucial role. For a "predictive materials science modeling with microscopic
understanding", a description that treats the statistical interplay of a large
number of microscopically well-described elementary processes must therefore be
applied. Modern electronic structure theory methods such as DFT have become a
standard tool for the accurate description of individual molecular processes.
Here, we discuss the present status of emerging methodologies which attempt to
achieve a (hopefully seamless) match of DFT with concepts from statistical
mechanics or thermodynamics, in order to also address the interplay of the
various molecular processes. The new quality of, and the novel insights that
can be gained by, such techniques is illustrated by how they allow the
description of crystal surfaces in contact with realistic gas-phase
environments.Comment: 24 pages including 17 figures, related publications can be found at
http://www.fhi-berlin.mpg.de/th/paper.htm
Autoantibodies against a 43 KDa Muscle Protein in Inclusion Body Myositis
BACKGROUND: Inclusion body myositis (IBM) is a poorly understood and refractory autoimmune muscle disease. Though widely believed to have no significant humoral autoimmunity, we sought to identify novel autoantibodies with high specificity for this disease. METHODOLOGY/PRINCIPAL FINDINGS: Plasma autoantibodies from 65 people, including 25 with IBM, were analyzed by immunoblots against normal human muscle. Thirteen of 25 (52%) IBM patient samples recognized an approximately 43 kDa muscle protein. No other disease (N = 25) or healthy volunteer (N = 15) samples recognized this protein. CONCLUSIONS: Circulating antibodies against a 43-kDa muscle autoantigen may lead to the discovery of a novel biomarker for IBM. Its high specificity for IBM among patients with autoimmune myopathies furthermore suggests a relationship to disease pathogenesis
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