353 research outputs found

    Results of the August 1977 Soviet and American meterological rocketsonde intercomparison held at Wallops Island, Virginia

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    A coordinated program of rocketsonde investigations along about 60 deg E and 70 deg W between the United States and U.S.S.R. is discussed. The rocketsonde instruments used by the U.S. and U.S.S.R. were compared and the results are presented. The U.S. Super Loki Datasonde and the U.S.S.R. M100B rocketsonde are discussed. Results indicate that the U.S/U.S.S.R. rocketsonde measurement agreement improved since the 1973 intercomparisons. It was learned that the mean of the differences of the temperatures compare to within 6 C at about 60 km and to within 2 C near 50 km. Wind measurements were also found to agree

    ІСТОРІЯ РОЗВИТКУ СЕСТРИНСЬКОЇ СПРАВИ В УКРАЇНІ (ОГЛЯД ЛІТЕРАТУРИ)

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    The article describes the main stages of Nursing development in Ukraine from the time of Kyiv Rus throught the independent Ukraine.У статті висвітлено основні етапи розвитку медсестринства в Україні з часів Київської Русі аж до сьогодні

    On the constants in a Kato inequality for the Euler and Navier-Stokes equations

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    We continue an analysis, started in [10], of some issues related to the incompressible Euler or Navier-Stokes (NS) equations on a d-dimensional torus T^d. More specifically, we consider the quadratic term in these equations; this arises from the bilinear map (v, w) -> v . D w, where v, w : T^d -> R^d are two velocity fields. We derive upper and lower bounds for the constants in some inequalities related to the above bilinear map; these bounds hold, in particular, for the sharp constants G_{n d} = G_n in the Kato inequality | < v . D w | w >_n | <= G_n || v ||_n || w ||^2_n, where n in (d/2 + 1, + infinity) and v, w are in the Sobolev spaces H^n, H^(n+1) of zero mean, divergence free vector fields of orders n and n+1, respectively. As examples, the numerical values of our upper and lower bounds are reported for d=3 and some values of n. When combined with the results of [10] on another inequality, the results of the present paper can be employed to set up fully quantitative error estimates for the approximate solutions of the Euler/NS equations, or to derive quantitative bounds on the time of existence of the exact solutions with specified initial data; a sketch of this program is given.Comment: LaTeX, 39 pages. arXiv admin note: text overlap with arXiv:1007.4412 by the same authors, not concerning the main result

    Aggregation of platelets, proliferation of endothelial cells and motility of cancer cells are mediated by the Bβ1(15)-42 residue of fibrin(ogen)

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    The fibrinogen molecule contains multiple binding motifs for different types of cellular receptors, acting as a molecular link between coagulation and cell adhesion. In this study we generated a truncated form of the fibrinogen molecule lacking the Bβ1-42 sequence by site-specific proteolysis and evaluated the role of the fragment in adhesive capabilities of platelets, endothelial and cancer cells. Fibrinogen with the removed Bβ1-42 sequence and fibrin without the Bβ15-42 fragment (desβ1-42 fibrinogen and desABβ15-42 fibrin) were obtained by proteolysis using the specific protease from the venom of Echis multisquamatis. The cleaved fragment was purified by HPLC and was identified using MALDI-TOF. ADP- and collagen-induced aggregation of washed platelets in the presence of fibrinogen desBβ1-42 was studied using an aggregometer. Proliferation of mice aortic endothelial cells (MAEC) and human umbilical vein endothelial cells (HUVEC) was studied using the fibrin desABβ15-42 as the scaffold. Cell viability was quantified by the MTT test (MAEC). Generation time was calculated for the estimation of proliferative activity of HUVEC. Lung cancer cell line Н1299 was used to evaluate cancer cell motility in vitro using the scratch assay. Direct comparison of cellular behavior in the presence of truncated vs native forms demonstrated attenuated cell adhesion in the presence of fibrinogen desBβ1-42 and fibrin desBβ15-42. The platelet aggregation rate was only slightly decreased in the presence of fibrinogen desBβ1-42 but resulted in 15-20% disaggregation of adhered platelets. We also observed the substantial decrease of generation time of HUVEC and inhibition of viability of MAEC cells grown on scaffolds of a desABβ15-42 matrix. Finally, desBβ1-42 modulated the motility of H1299 cells in vitro and suppressed the wound healing by 20% compared to the full-length fibrinogen. We postulate that fragment 1-42 of the BβN-domain of fibrinogen is not sufficient for platelet aggregation, however it may contribute to platelet clot formation in later stages. At the same time, this fragment may be important for establishing proper cell-to-cell contacts and cell viability of endothelial cells. Also, 1-42 amino acid fragment of the BβN-domain supported the migration of cancer cells suggesting that interactions of fibrinogen with cancer cells could be a target for anticancer therapy. The Bβ1-42 fragment of fibrinogen contributes to efficient intracellular interactions of different types of cells, including platelets, endothelial cells and cancer cells

    Entrepreneurship, professionalism, leadership: A framework and measure for understanding boundaryless careers

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    We propose a person-centered framework for conceptualizing subjective careers in an increasingly boundaryless work context. Specifically, we argue that entrepreneurship, professionalism, and leadership (EPL) can serve as three key dimensions of subjective career space. We relate this framework to earlier macro-level national and organizational career models proposed by Kanter (1989) and Schein (1978). Our empirical study involving 10,326 Singaporean university students demonstrated that entrepreneurial, professional, and leadership career aspirations (including motivations, efficacies, and intentions) can be measured independently, that these career dimensions are independent of vocational interests, and that they are to some degree viewed as competing career alternatives. We also show that EPL motivation profiles can operationalize the boundaryless and protean career concepts. Individuals concurrently high in entrepreneurial, professional, and leadership career motivations, and those high in entrepreneurial and leadership motivations are highest in boundaryless and self-directed career attitudes, while those primarily motivated for professional careers hold the most traditional career attitudes. We conclude by discussing the potential of the framework for understanding human resource issues at organizational and national levels and for enhancing the study of entrepreneurship, professionalism, and leadership

    Some recommendations for developing multidimensional computerized adaptive tests for patient-reported outcomes

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    PURPOSE: Multidimensional item response theory and computerized adaptive testing (CAT) are increasingly used in mental health, quality of life (QoL), and patient-reported outcome measurement. Although multidimensional assessment techniques hold promises, they are more challenging in their application than unidimensional ones. The authors comment on minimal standards when developing multidimensional CATs. METHODS: Prompted by pioneering papers published in QLR, the authors reflect on existing guidance and discussions from different psychometric communities, including guidelines developed for unidimensional CATs in the PROMIS project. RESULTS: The commentary focuses on two key topics: (1) the design, evaluation, and calibration of multidimensional item banks and (2) how to study the efficiency and precision of a multidimensional item bank. The authors suggest that the development of a carefully designed and calibrated item bank encompasses a construction phase and a psychometric phase. With respect to efficiency and precision, item banks should be large enough to provide adequate precision over the full range of the latent constructs. Therefore CAT performance should be studied as a function of the latent constructs and with reference to relevant benchmarks. Solutions are also suggested for simulation studies using real data, which often result in too optimistic evaluations of an item bank's efficiency and precision. DISCUSSION: Multidimensional CAT applications are promising but complex statistical assessment tools which necessitate detailed theoretical frameworks and methodological scrutiny when testing their appropriateness for practical applications. The authors advise researchers to evaluate item banks with a broad set of methods, describe their choices in detail, and substantiate their approach for validation

    Studies of η\eta and η\eta' production in pppp and ppPb collisions

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    The production of η\eta and η\eta' mesons is studied in proton-proton and proton-lead collisions collected with the LHCb detector. Proton-proton collisions are studied at center-of-mass energies of 5.025.02 and 13 TeV13~{\rm TeV}, and proton-lead collisions are studied at a center-of-mass energy per nucleon of 8.16 TeV8.16~{\rm TeV}. The studies are performed in center-of-mass rapidity regions 2.5<yc.m.<3.52.5<y_{\rm c.m.}<3.5 (forward rapidity) and 4.0<yc.m.<3.0-4.0<y_{\rm c.m.}<-3.0 (backward rapidity) defined relative to the proton beam direction. The η\eta and η\eta' production cross sections are measured differentially as a function of transverse momentum for 1.5<pT<10 GeV1.5<p_{\rm T}<10~{\rm GeV} and 3<pT<10 GeV3<p_{\rm T}<10~{\rm GeV}, respectively. The differential cross sections are used to calculate nuclear modification factors. The nuclear modification factors for η\eta and η\eta' mesons agree at both forward and backward rapidity, showing no significant evidence of mass dependence. The differential cross sections of η\eta mesons are also used to calculate η/π0\eta/\pi^0 cross section ratios, which show evidence of a deviation from the world average. These studies offer new constraints on mass-dependent nuclear effects in heavy-ion collisions, as well as η\eta and η\eta' meson fragmentation.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/Publications/p/LHCb-PAPER-2023-030.html (LHCb public pages

    Fraction of χc\chi_c decays in prompt J/ψJ/\psi production measured in pPb collisions at sNN=8.16\sqrt{s_{NN}}=8.16 TeV

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    The fraction of χc1\chi_{c1} and χc2\chi_{c2} decays in the prompt J/ψJ/\psi yield, Fχc=σχcJ/ψ/σJ/ψF_{\chi c}=\sigma_{\chi_c \to J/\psi}/\sigma_{J/\psi}, is measured by the LHCb detector in pPb collisions at sNN=8.16\sqrt{s_{NN}}=8.16 TeV. The study covers the forward (1.5<y<4.01.5<y^*<4.0) and backward (5.0<y<2.5-5.0<y^*<-2.5) rapidity regions, where yy^* is the J/ψJ/\psi rapidity in the nucleon-nucleon center-of-mass system. Forward and backward rapidity samples correspond to integrated luminosities of 13.6 ±\pm 0.3 nb1^{-1} and 20.8 ±\pm 0.5 nb1^{-1}, respectively. The result is presented as a function of the J/ψJ/\psi transverse momentum pT,J/ψp_{T,J/\psi} in the range 1<pT,J/ψ<20<p_{T, J/\psi}<20 GeV/cc. The FχcF_{\chi c} fraction at forward rapidity is compatible with the LHCb measurement performed in pppp collisions at s=7\sqrt{s}=7 TeV, whereas the result at backward rapidity is 2.4 σ\sigma larger than in the forward region for 1<pT,J/ψ<31<p_{T, J/\psi}<3 GeV/cc. The increase of FχcF_{\chi c} at low pT,J/ψp_{T, J/\psi} at backward rapidity is compatible with the suppression of the ψ\psi(2S) contribution to the prompt J/ψJ/\psi yield. The lack of in-medium dissociation of χc\chi_c states observed in this study sets an upper limit of 180 MeV on the free energy available in these pPb collisions to dissociate or inhibit charmonium state formation.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-028.html (LHCb public pages

    Search for CP\textit{CP} violation in the phase space of D0KS0K±πD^{0} \rightarrow K_{S}^{0} K^{\pm} \pi^{\mp} decays with the energy test

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    A search for CP\textit{CP} violation in D0KS0K+πD^{0} \rightarrow K_{S}^{0} K^{+} \pi^{-} and D0KS0Kπ+D^{0} \rightarrow K_{S}^{0} K^{-} \pi^{+} decays is reported. The search is performed using an unbinned model-independent method known as the energy test that probes local CP\textit{CP} violation in the phase space of the decays. The data analysed correspond to an integrated luminosity of 5.4 5.4~fb1^{-1} collected in proton-proton collisions by the LHCb experiment at a centre-of-mass energy of s=13\sqrt{s}=13~TeV, amounting to approximately 950000 and 620000 signal candidates for the D0KS0Kπ+D^{0} \rightarrow K_{S}^{0} K^{-} \pi^{+} and D0KS0K+πD^{0} \rightarrow K_{S}^{0} K^{+} \pi^{-} modes, respectively. The method is validated using D0Kπ+ππ+D^{0} \rightarrow K^{-} \pi^{+} \pi^{-} \pi^{+} and D0KS0π+πD^{0} \rightarrow K_{S}^{0} \pi^{+} \pi^{-} decays, where CP\textit{CP}-violating effects are expected to be negligible, and using background-enhanced regions of the signal decays. The results are consistent with CP\textit{CP} symmetry in both the D0KS0Kπ+D^{0} \rightarrow K_{S}^{0} K^{-} \pi^{+} and the D0KS0K+πD^{0} \rightarrow K_{S}^{0} K^{+} \pi^{-} decays, with pp-values for the hypothesis of no CP\textit{CP} violation of 70% and 66%, respectively.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-019.html (LHCb public pages

    Enhanced production of Λb0\Lambda_{b}^{0} baryons in high-multiplicity pppp collisions at s=13\sqrt{s} = 13 TeV

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    The production rate of Λb0\Lambda_{b}^{0} baryons relative to B0B^{0} mesons in pppp collisions at a center-of-mass energy s=13\sqrt{s} = 13 TeV is measured by the LHCb experiment. The ratio of Λb0\Lambda_{b}^{0} to B0B^{0} production cross-sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e+ee^{+}e^{-} collisions, and increases by a factor of 2\sim2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λb0\Lambda_{b}^{0} to B0B^{0} cross-sections is higher than what is measured in e+ee^{+}e^{-} collisions, but converges with the e+ee^{+}e^{-} ratio as the momentum increases. These results imply that the evolution of heavy bb quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with a statistical hadronization model and implications for the mechanisms enforcing quark confinement are discussed.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-027.html (LHCb public pages
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