16,824 research outputs found
The momentum distribution of J/psi in B decays
The discrepancy between theory and data in the momentum distribution of slow
J/psi in B decays has been several times addressed as a puzzle. Using the most
recent results on exclusive B decays into J/psi and heavy kaons or exotic
mesons and reconsidering the non-relativistic-QCD calculation of the color
octet fragmentation component, we show that an improvement in the comparison
between data and theory can be obtained. There is still room for a better fit
to data and this may imply that new exotic mesons of the XYZ kind have yet to
be discovered.Comment: 4 pages, 2 figures, 2 tables. To appear in Physical Review
The interplay of managerial and non-managerial controls, institutional work, and the coordination of laterally dependent hospital activities
This is the author accepted manuscript. The final version is available from Emerald via the DOI in this record.Purpose
The purpose of this paper is to explore two hospital departments, one of which is laterally dependent on the other to function, but which are subject to distinct vertical managerial controls. This complexity in vertical–lateral relations generates tension amongst the hospital’s senior managers and a perception of coordination difficulties. However, this paper shows how the interplay between managerial and non-managerial controls, plus important employee “work”, moderates tension and facilitates day-to-day lateral coordination at the patient-facing level.
Design/methodology/approach
This is a case-study, relying mostly on the findings of semi-structured interviews. Theoretically, the paper draws from previous insights on inter-organisational relations (but informing the focus on intra-organisational coordination) and an “institutional work” perspective.
Findings
Consistent with much extant literature, this paper reveals how non-managerial controls help to moderate tensions that could emerge from the coercive use of managerial controls. However, the authors also show a maintained influence and flexibility in the managerial controls at patient-facing levels, as new circumstances unfold.
Research limitations/implications
The findings of this paper could generalise neither all laterally dependent spaces in hospitals nor patterns across different hospitals. The authors recommend future research into the dynamics and interaction of managerial and non-managerial controls in other complex settings, plus focus on the purposeful work of influential agents.
Originality/value
The paper has two primary contributions: extending our knowledge of the interplay between managerial and non-managerial controls inside complex organisations, where non-managerial controls reinforce rather than displace managerial controls, and highlighting that it is seldom just controls per se which “matter”, but also agents’ purposeful actions that facilitate coordination in complex organisations
Tablet Use by Occupational Therapists for Preliteracy Learning with Preschool Children
Purpose: Tablet technologies are being used in pediatric occupational therapy (OT) despite a dearth of literature supporting their use. The purpose of this study was to investigate key strategies and decision-making considerations occupational therapists are using with tablet technologies to develop preliteracy skills with preschool aged children. Method: An ethnographic study of three pediatric occupational therapists (one school-based; one private clinic; and one school-based/private clinic) was conducted through semi-structured interviews and observations of the participants using the tablet. Results: One central theme, that tablets are “just a tool,” and three subthemes, that tablets are versatile, motivating, and fun, were identified. Results indicated that participants in this study are using tablets purposefully as a tool and as an alternative to traditional preliteracy activities. Conclusion: It is becoming more important for therapists to integrate the tablet and other mainstream technology into their practice in order to assist children in learning how to navigate an increasingly digital world. Further research regarding the efficacy of using tablet technology in pediatric occupational therapy is recommended
Developmental expression of claudins in the mammary gland
Claudins are a large family of membrane proteins whose classic function is to regulate the permeability of tight junctions in epithelia. They are tetraspanins, with four alpha-helices crossing the membrane, two extracellular loops, a short cytoplasmic N-terminus and a longer and more variable C-terminus. The extracellular ends of the helices are known to undergo side-to-side (cis) interactions that allow the formation of claudin polymers in the plane of the membrane. The extracellular loops also engage in head-to-head (trans) interactions thought to mediate the formation of tight junctions. However, claudins are also present in intracellular structures, thought to be vesicles, with less well-characterized functions. Here, we briefly review our current understanding of claudin structure and function followed by an examination of changes in claudin mRNA and protein expression and localization through mammary gland development. Claudins-1, 3, 4, 7, and 8 are the five most prominent members of the claudin family in the mouse mammary gland, with varied abundance and intracellular localization during the different stages of post-pubertal development. Claudin-1 is clearly localized to tight junctions in mammary ducts in non-pregnant non-lactating animals. Cytoplasmic puncta that stain for claudin-7 are present throughout development. During pregnancy claudin-3 is localized both to the tight junction and basolaterally while claudin-4 is found only in sparse puncta. In the lactating mouse both claudin-3 and claudin-8 are localized at the tight junction where they may be important in forming the paracellular barrier. At involution and under challenge by lipopolysaccharide claudins -1, -3, and -4 are significantly upregulated. Claudin-3 is still colocalized with tight junction molecules but is also distributed through the cytoplasm as is claudin-4. These largely descriptive data provide the essential framework for future mechanistic studies of the function and regulation of mammary epithelial cell claudins
Spectroscopic Observations of Convective Patterns in the Atmospheres of Metal-Poor Stars
Convective line asymmetries in the optical spectrum of two metal-poor stars,
Gmb1830 and HD140283, are compared to those observed for solar metallicity
stars. The line bisectors of the most metal-poor star, the subgiant HD140283,
show a significantly larger velocity span that the expectations for a
solar-metallicity star of the same spectral type and luminosity class. The
enhanced line asymmetries are interpreted as the signature of the lower metal
content, and therefore opacity, in the convective photospheric patterns. These
findings point out the importance of three-dimensional convective velocity
fields in the interpretation of the observed line asymmetries in metal-poor
stars, and in particular, urge for caution when deriving isotopic ratios from
observed line shapes and shifts using one-dimensional model atmospheres.
The mean line bisector of the photospheric atomic lines is compared with
those measured for the strong Mg I b1 and b2 features. The upper part of the
bisectors are similar, and assuming they overlap, the bottom end of the
stronger lines, which are formed higher in the atmosphere, goes much further to
the red. This is in agreement with the expected decreasing of the convective
blue-shifts in upper atmospheric layers, and compatible with the high velocity
redshifts observed in the chromosphere, transition region, and corona of
late-type stars.Comment: 27 pages, LaTeX; 10 Figures (14 PostScript files); to be published in
The Astrophysical Journa
Homomorphic Processing Of Acoustic Logging Data
A new processing method, which we developed for the guided waves generated during
acoustic logging, accurately estimates the wavenumber when only a few seismograms
are available or when the seismograms are irregularly spaced. The estimates of the
attenuation coefficient are seemingly accurate when many seismograms are available
but are inaccurate when only a few seismograms are available. The new method does
not generate any spurious estimates as the Prony-based method does.Halliburton CompanyMassachusetts Institute of Technology. Full Waveform Acoustic Logging Consortiu
The Scent of Change: A Case Study
Decisions about entering into a new business venture involve a variety of considerations, despite the level of experience an entrepreneur has. This case presents the story of a business owner Bennett Gage and his decisions concerning whether or not he should enter into a business where canines are used to detect bed bugs in hotels. This case study gives the reader an opportunity to wrestle with some of the many questions that are part of entering into the creation of a new service
- …