3,346 research outputs found
Web 2.0 and micro-businesses: An exploratory investigation
This is the author's final version of the article. This article is (c) Emerald Group Publishing and permission has been granted for this version to appear here. Emerald does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Emerald Group Publishing Limited.This article was chosen as a Highly Commended Award Winner at the Emerald Literati Network Awards for Excellence 2013.Purpose â The paper aims to report on an exploratory study into how small businesses use Web 2.0 information and communication technologies (ICT) to work collaboratively with other small businesses. The study had two aims: to investigate the benefits available from the use of Web 2.0 in small business collaborations, and to characterize the different types of such online collaborations.
Design/methodology/approach â The research uses a qualitative case study methodology based on semi-structured interviews with the owner-managers of 12 UK-based small companies in the business services sector who are early adopters of Web 2.0 technologies.
Findings â Benefits from the use of Web 2.0 are categorized as lifestyle benefits, internal operational efficiency, enhanced capability, external communications and enhanced service offerings. A 2Ă2 framework is developed to categorize small business collaborations using the dimensions of the basis for inter-organizational collaboration (control vs cooperation) and the level of Web 2.0 ICT use (simple vs sophisticated).
Research limitations/implications â A small number of firms of similar size, sector and location were studied, which limits generalizability. Nonetheless, the results offer a pointer to the likely future use of Web 2.0 tools by other small businesses.
Practical implications â The research provides evidence of the attraction and potential of Web 2.0 for collaborations between small businesses.
Originality/value â The paper is one of the first to report on use of Web 2.0 ICT in collaborative working between small businesses. It will be of interest to those seeking a better understanding of the potential of Web 2.0 in the small business community.WestFocu
Similarity of nuclear structure in 132Sn and 208Pb regions: proton-neutron multiplets
Starting from the striking similarity of proton-neutron multiplets in 134Sb
and 210Bi, we perform a shell-model study of nuclei with two additional protons
or neutrons to find out to what extent this analogy persists. We employ
effective interactions derived from the CD-Bonn nucleon-nucleon potential
renormalized by use of the V-low-k approach. The calculated results for 136Sb,
212Bi, 136I, and 212At are in very good agreement with the available
experimental data. The similarity between 132Sn and 208Pb regions is discussed
in connection with the effective interaction, emphasizing the role of core
polarization effects.Comment: 4 pages, 3 figures, 2 table
COBE ground segment gyro calibration
Discussed here is the calibration of the scale factors and rate biases for the Cosmic Background Explorer (COBE) spacecraft gyroscopes, with the emphasis on the adaptation for COBE of an algorithm previously developed for the Solar Maximum Mission. Detailed choice of parameters, convergence, verification, and use of the algorithm in an environment where the reference attitudes are determined form the Sun, Earth, and star observations (via the Diffuse Infrared Background Experiment (DIRBE) are considered. Results of some recent experiments are given. These include tests where the gyro rate data are corrected for the effect of the gyro baseplate temperature on the spacecraft electronics
Embryonic sympathoblasts transiently express TrkB in vivo and proliferate in response to brain-derived neurotrophic factor in vitro
BACKGROUND: Nerve growth factor and neurotrophin-3 are involved in the development of sympathetic neurons; however, whether brain derived neurotrophic factor also plays a role is not known. The purpose of this study was to determine whether BDNF and its receptor, TrkB, are expressed during the development of paravertebral sympathetic ganglia in vivo and to determine the effect of BDNF in vitro. RESULTS: As neural crest cells coalesce to form sympathetic ganglia, TrkB-positive cells are seen in both chicken and mouse embryos. In chicken embryos, TrkB-expressing cells first appear at Hamburger-Hamilton Stage (St) 27 and they co-express HNK-1, confirming that they are migrating neural crest cells. The TrkB-positive cells lack neural markers at this stage; however, they migrate with other neurally differentiating cells that are TrkA and TrkC-positive. By St. 29/30, TrkB-positive cells begin to express the neural specific markers Hu C/D and Islet-1; eventually, all TrkB positive cells commence neural differentiation. By St. 34, TrkB and TrkC staining are lost. BDNF transcript expression parallels that of TrkB. In the mouse, TrkB-positive cells surround newly formed sympathetic ganglia and a small number of TrkB positive cells that co-express tyrosine hydroxylase are seen within ganglia between E13.5-15. In cell culture, many cells from St. 29â30 chicken lumbar sympathetic ganglia express neural markers and are dividing, indicating that they are sympathoblasts. Sympathoblasts and neurons require both nerve growth factor and neurotrophin-3 for survival. BDNF increases the number of cells expressing neural markers in culture by increasing number of cells that incorporate bromodeoxyuridine. In contrast, most TrkB-positive sympathetic cells in vivo are not actively proliferating between E6âE8. CONCLUSION: Developing paravertebral sympathetic ganglia in avian and murine embryos contain a subpopulation of sympathoblasts that transiently express TrkB and ultimately commence neuronal differentiation. These TrkB expressing sympathoblasts are not actively dividing in vivo; yet, when placed in vitro, will divide in response to BDNF. This suggests that the availability of BDNF in vivo fails to reach a threshold necessary to induce proliferation. We suggest that excess TrkB stimulation of sympathoblasts in vivo may lead to the genesis of neuroblastoma
Laser cooling of a nanomechanical resonator mode to its quantum ground state
We show that it is possible to cool a nanomechanical resonator mode to its
ground state. The proposed technique is based on resonant laser excitation of a
phonon sideband of an embedded quantum dot. The strength of the sideband
coupling is determined directly by the difference between the electron-phonon
couplings of the initial and final states of the quantum dot optical
transition. Possible applications of the technique we describe include
generation of non-classical states of mechanical motion.Comment: 5 pages, 3 figures, revtex
Combining shock barometry with numerical modeling: insights into complex crater formation â The example of the Siljan impact structure (Sweden)
Siljan, central Sweden, is the largest known impact structure in Europe. It was formed at about 380 Ma, in the late Devonian period. The structure has been heavily eroded to a level originally located underneath the crater floor, and to date, important questions about the original size and morphology of Siljan remain unanswered. Here we present the results of a shock barometry study of quartz-bearing surface and drill core samples combined with numerical modeling using iSALE. The investigated 13 bedrock granitoid samples show that the recorded shock pressure decreases with increasing depth from 15 to 20 GPa near the (present) surface, to 10â15 GPa at 600 m depth. A best-fit model that is consistent with observational constraints relating to the present size of the structure, the location of the downfaulted sediments, and the observed surface and vertical shock barometry profiles is presented. The best-fit model results in a final crater (rim-to-rim) diameter of ~65 km. According to our simulations, the original Siljan impact structure would have been a peak-ring crater. Siljan was formed in a mixed target of Paleozoic sedimentary rocks overlaying crystalline basement. Our modeling suggests that, at the time of impact, the sedimentary sequence was approximately 3 km thick. Since then, there has been around 4 km of erosion of the structure
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A Potent and Effective Suicidal Listeria Vaccine Platform.
Live-attenuated Listeria monocytogenes has shown encouraging potential as an immunotherapy platform in preclinical and clinical settings. However, additional safety measures will enable application across malignant and infectious diseases. Here, we describe a new vaccine platform, termed Lm-RIID (L. monocytogenes recombinase-induced intracellular death), that induces the deletion of genes required for bacterial viability yet maintains potent T cell responses to encoded antigens. Lm-RIID grows normally in broth but commits suicide inside host cells by inducing Cre recombinase and deleting essential genes flanked by loxP sites, resulting in a self-limiting infection even in immunocompromised mice. Lm-RIID vaccination of mice induces potent CD8+ T cells and protects against virulent challenges, similar to live L. monocytogenes vaccines. When combined with α-PD-1, Lm-RIID is as effective as live-attenuated L. monocytogenes in a therapeutic tumor model. This impressive efficacy, together with the increased clearance rate, makes Lm-RIID ideal for prophylactic immunization against diseases that require T cells for protection
Kelvin-Helmholtz instability in partially ionized compressible plasmas
The Kelvin-Helmholtz Instability (KHI) has been observed in the solar
atmosphere. Ion-neutral collisions may play a relevant role for the growth rate
and evolution of the KHI in solar partially ionized plasmas as in, e.g., solar
prominences. Here, we investigate the linear phase of the KHI at an interface
between two partially ionized magnetized plasmas in the presence of a shear
flow. The effects of ion-neutral collisions and compressibility are included in
the analysis. We obtain the dispersion relation of the linear modes and perform
parametric studies of the unstable solutions. We find that in the
incompressible case the KHI is present for any velocity shear regardless the
value of the collision frequency. In the compressible case, the domain of
instability depends strongly on the plasma parameters, specially the collision
frequency and the density contrast. For high collision frequencies and low
density contrasts the KHI is present for super-Alfvenic velocity shear only.
For high density contrasts the threshold velocity shear can be reduced to
sub-Alfvenic values. For the particular case of turbulent plumes in
prominences, we conclude that sub-Alfvenic flow velocities can trigger the KHI
thanks to the ion-neutral coupling.Comment: Accepted for publication in Ap
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