62 research outputs found
Inflammation Triggers Emergency Granulopoiesis through a Density-Dependent Feedback Mechanism
Normally, neutrophil pools are maintained by homeostatic mechanisms that require
the transcription factor C/EBPα. Inflammation, however, induces neutrophilia
through a distinct pathway of “emergency” granulopoiesis that is
dependent on C/EBPβ. Here, we show in mice that alum triggers emergency
granulopoiesis through the IL-1RI-dependent induction of G-CSF. G-CSF/G-CSF-R
neutralization impairs proliferative responses of hematopoietic stem and
progenitor cells (HSPC) to alum, but also abrogates the acute mobilization of BM
neutrophils, raising the possibility that HSPC responses to inflammation are an
indirect result of the exhaustion of BM neutrophil stores. The induction of
neutropenia, via depletion with Gr-1 mAb or myeloid-specific ablation of Mcl-1,
elicits G-CSF via an IL-1RI-independent pathway, stimulating granulopoietic
responses indistinguishable from those induced by adjuvant. Notably, C/EBPβ,
thought to be necessary for enhanced generative capacity of BM, is dispensable
for increased proliferation of HSPC to alum or neutropenia, but plays a role in
terminal neutrophil differentiation during granulopoietic recovery. We conclude
that alum elicits a transient increase in G-CSF production via IL-1RI for the
mobilization of BM neutrophils, but density-dependent feedback sustains G-CSF
for accelerated granulopoiesis
Sustained Effects of Incredible Years as a Preventive Intervention in Preschool Children with Conduct Problems
The present study evaluated preventive effects of the Incredible Years program for parents of preschool children who were at risk for a chronic pattern of conduct problems, in the Netherlands. In a matched control design, 72 parents of children with conduct problems received the Incredible Years program. These families (intervention group) were compared with 72 families who received care as usual (control group). Two years after termination of the intervention, it appeared that observed and selfrated parenting skills were significantly improved in the intervention group. Likewise, in this group, observed child conduct problems showed sustained intervention effects. The decrease in observed critical parenting mediated the decrease in observed child conduct problems over time. In addition, it appeared that parental influence increased over time
Evidence for widespread hydrated minerals on asteroid (101955) Bennu
Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth
The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements
The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids
Relational geometries of the body: Doing ethnographic fieldwork
© 2015, Springer International Publishing Switzerland. This chapter takes a practice-theory informed approach to understanding the body doing ethnographic fieldwork. It treats ethnographic fieldwork as a form of professional practice, albeit a contested one, in which the notion of embodiment is widely established. However new lines of understanding and new ways of giving accounts of these practices are opened up by contemporary practice theories. In particular this chapter takes up the work of Schatzki, and links this to the framing developed by Green and Hopwood (Chap. 2, this volume) – the body as background, resource, and metaphor. These are used to present and expand the concept of relational geometries of the body, a distinctive and useful tool for grappling with questions of the body in fieldwork practice. The geometric approach highlights relationality between the ethnographer and other bodies (including material artefacts), viewing this as central to judgements and performances in fieldwork, and intimately folded into the intellectual and ethical work of ethnographic research. In this way the account rejects Cartesian mind/body dualisms, and instead focuses on the shifting relationships of the doing body
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