34 research outputs found
The Resilient Organization: A Meta-Analysis of the Effect of Communication on Team Diversity and Team Performance
The Input-Process-Output framework is adopted to examine the impact of diversity attributes (the input) on communication (the process) and their influence on performance (the output), to understand the internal group/team working mechanisms of organizational resilience. A meta-analysis of 174 correlations from 35 empirical studies undertaken over 35 years (1982-2017) showed that members of a team who have different experiences are more likely to share information and communicate openly when they deal with a task that requires collaboration outside the team. This supports the view that organizations are more resilient by being more closely connected with the external environment. Differences in social categories tend to favor openness of communication, especially in the case of age diversity and race/ethnicity diversity. An increase in openness of communication is likely to enhance team performance, particularly for small and medium sized teams operating in manufacturing industries, while frequency of communication can be beneficial for both large and medium sized teams working in the high technology industry. The positive workings of these associations form the resilient organization
Indirect signals from light neutralinos in supersymmetric models without gaugino mass unification
We examine indirect signals produced by neutralino self-annihilations, in the
galactic halo or inside celestial bodies, in the frame of an effective MSSM
model without gaugino-mass unification at a grand unification scale. We compare
our theoretical predictions with current experimental data of gamma-rays and
antiprotons in space and of upgoing muons at neutrino telescopes. Results are
presented for a wide range of the neutralino mass, though our discussions are
focused on light neutralinos. We find that only the antiproton signal is
potentially able to set constraints on very low-mass neutralinos, below 20 GeV.
The gamma-ray signal, both from the galactic center and from high galactic
latitudes, requires significantly steep profiles or substantial clumpiness in
order to reach detectable levels. The up-going muon signal is largely below
experimental sensitivities for the neutrino flux coming from the Sun; for the
flux from the Earth an improvement of about one order of magnitude in
experimental sensitivities (with a low energy threshold) can make accessible
neutralino masses close to O, Si and Mg nuclei masses, for which resonant
capture is operative.Comment: 17 pages, 1 tables and 5 figures, typeset with ReVTeX4. The paper may
also be found at http://www.to.infn.it/~fornengo/papers/indirect04.ps.gz or
through http://www.astroparticle.to.infn.it/. Limit from BR(Bs--> mu+ mu-)
adde
The Search for the Sidereal and Solar Diurnal Modulations in the Total MACRO Muon Data Set
We have analyzed 44.3M single muons collected by MACRO from 1991 through 2000
in 2,145 live days of operation. We have searched for the solar diurnal,
apparent sidereal, and pseudo-sidereal modulation of the underground muon rate
by computing hourly deviations of the muon rate from 6 month averages. We find
evidence for statistically significant modulations with the solar diurnal and
the sidereal periods. The amplitudes of these modulations are <0.1%, and are at
the limit of the detector statistics. The pseudo-sidereal modulation is not
statistically significant.
The solar diurnal modulation is due to the daily atmospheric temperature
variations at 20 km, the altitude of primary cosmic ray interactions with the
atmosphere; MACRO is the deepest experiment to report this result. The sidereal
modulation is in addition to the expected Compton-Getting modulation due to
solar system motion relative to the Local Standard of Rest; it represents
motion of the solar system with respect to the galactic cosmic rays toward the
Perseus spiral arm.Comment: 18 pages, 8 of which are figures, 1 is a table. Accepted by Phys.
Rev.
Roles of FGF signaling in stem cell self-renewal, senescence and aging.
The aging process decreases tissue function and regenerative capacity, which has been associated with cellular senescence and a decline in adult or somatic stem cell numbers and self-renewal within multiple tissues. The potential therapeutic application of stem cells to reduce the burden of aging and stimulate tissue regeneration after trauma is very promising. Much research is currently ongoing to identify the factors and molecular mediators of stem cell self-renewal to reach these goals. Over the last two decades, fibroblast growth factors (FGFs) and their receptors (FGFRs) have stood up as major players in both embryonic development and tissue repair. Moreover, many studies point to somatic stem cells as major targets of FGF signaling in both tissue homeostasis and repair. FGFs appear to promote self-renewing proliferation and inhibit cellular senescence in nearly all tissues tested to date. Here we review the role of FGFs and FGFRs in stem cell self-renewal, cellular senescence, and aging
Loss of the osteogenic differentiation potential during senescence is limited to bone progenitor cells and is dependent on p53.
DNA damage can lead to the induction of cellular senescence. In particular, we showed that exposure to ionizing radiation (IR) leads to the senescence of bone marrow-derived multipotent stromal cells (MSC) and osteoblast-like stromal cells (OB-SC), a phenotype associated with bone loss. The mechanism by which IR leads to bone dysfunction is not fully understood. One possibility involves that DNA damage-induced senescence limits the regeneration of bone progenitor cells. Another possibility entails that bone dysfunction arises from the inability of accumulating senescent cells to fulfill their physiological function. Indeed, we show here that exposure to IR prevented the differentiation and mineralization functions of MSC, an effect we found was limited to this population as more differentiated OB-SC could still form mineralize nodules. This is in contrast to adipogenesis, which was inhibited in both IR-induced senescent MSC and 3T3-L1 pre-adipocytes. Furthermore, we demonstrate that IR-induced loss of osteogenic potential in MSC was p53-dependent, a phenotype that correlates with the inability to upregulate key osteogenic transcription factors. These results are the first to demonstrate that senescence impacts osteogenesis in a cell type dependent manner and suggest that the accumulation of senescent osteoblasts is unlikely to significantly contribute to bone dysfunction in a cell autonomous manner
Hierarchical scaffold design for mesenchymal stem cell-based gene therapy of hemophilia B
Gene therapy for hemophilia B and other hereditary plasma protein deficiencies showed great promise in pre-clinical and early clinical trials. However, safety concerns about in vivo delivery of viral vectors and poor post-transplant survival of ex vivo modified cells remain key hurdles for clinical translation of gene therapy. We here describe a 3D scaffold system based on porous hydroxyapatite-PLGA composites coated with biomineralized collagen 1. When combined with autologous gene-engineered factor IX (hFIX) positive mesenchymal stem cells (MSCs) and implanted in hemophilic mice, these scaffolds supported long-term engraftment and systemic protein delivery by MSCs in vivo. Optimization of the scaffolds at the macro-, micro- and nanoscales provided efficient cell delivery capacity, MSC self-renewal and osteogenesis respectively, concurrent with sustained delivery of hFIX. In conclusion, the use of gene-enhanced MSC-seeded scaffolds may be of practical use for treatment of hemophilia B and other plasma protein deficiencies. \ua9 2010 Elsevier Ltd.Peer reviewed: YesNRC publication: Ye