457 research outputs found
Overcoming inertia : drivers of the outsourcing process
Almost all managers have directly or indirectly been involved in the practice of outsourcing in recent years. But as they know, outsourcing is not straightforward. Outsourcing inertia, when companies are slow to adapt to changing circumstances that accommodate higher outsourcing levels, may undermine a firm’s performance. This article investigates the presence of outsourcing inertia and the factors that help managers overcome it. Using statistical evidence, we show that positive performance effects related to outsourcing can accumulate when circumstances change. This is then followed by rapid increases in outsourcing levels (i.e. outsourcing processes). We investigate what gives rise to these outsourcing processes through follow-up interviews with sourcing executives, which suggest five drivers behind outsourcing processes: managerial initiative (using outside experience); hierarchy (foreign headquarters); imitation (of competitors and of similar firms); outsider advice (from external institutions); knowledge sources (using external information). These five drivers all offer scope for managerial action. We tie them to academic literatures and suggest ways of investigating their presence and impact on the outsourcing process. Overall, we conclude that while economizing factors play a key role in explaining how much firms outsource, it is socializing factors that tend to drive outsourcing processes
High-precision estimate of g4 in the 2D Ising model
We compute the renormalized four-point coupling in the 2d Ising model using
transfer-matrix techniques. We greatly reduce the systematic uncertainties
which usually affect this type of calculations by using the exact knowledge of
several terms in the scaling function of the free energy. Our final result is
g4=14.69735(3).Comment: 17 pages, revised version with minor changes, accepted for
publication in Journal of Physics
Paediatric non-alcoholic fatty liver disease: impact on patients and mothers' quality of life
Background: Non-alcoholic fatty liver disease (NAFLD) is one of the causes of fatty liver in adults and is currently the primary form of chronic liver disease in children and adolescents. However, the psychological outcome (i.e. the behavioural problems that can in turn be related to psychiatric conditions, like anxiety and mood disorders, or lower quality of life) in children and adolescents suffering of NAFLD has not been extensively explored in the literature. Objectives: The present study aims at evaluating the emotional and behavioural profile in children suffering from NAFLD and the quality of life in their mothers. Patients and Methods: A total of 57 children (18 females/39 males) with NAFLD were compared to 39 age-matched control children (25 females/14 males). All participants were submitted to the following psychological tools to assess behavior, mood, and anxiety: the Multidimensional Anxiety Scale for Children (MASC), the Child Behavior Checklist (CBCL), and the Children's Depression Inventory (CDI). Moreover, the mothers of 40 NAFLD and 39 control children completed the World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire. Results: NAFLD children scored significantly higher as compared to control children in MASC (P = 0.001) and CDI total (P < 0.001) scales. The CBCL also revealed significantly higher scores for NAFLD children in total problems (P = 0.046), internalizing symptoms (P = 0.000) and somatic complaints (P < 0.001). The WHOQOL-BREF revealed significantly lower scores for the mothers of NAFLD children in the overall perception of the quality of life (P < 0.001), and in the "relationships" domain (P = 0.023). Conclusions: Increased emotional and behavioural problems were detected in children with NAFLD as compared to healthy control children, together with an overall decrease in their mothers' quality of life. These results support the idea that these patients may benefit from a psychological intervention, ideally involving both children and parents, whose quality of life is likely negatively affected by this disease
Confining Effective Theories Based on Instantons and Merons
An effective theory based on ensembles of either regular gauge instantons or
merons is shown to produce confinement in SU(2) Yang-Mills theory. When the
scale is set by the string tension, the action density, topological
susceptibility and low-lying glueball spectrum are similar to those arising in
lattice QCD. The physical mechanism producing confinement is explained, and a
number of analytical insights into the effective theory are presented.Comment: 53 pages, 41 figure
Confining strings in representations with common -ality
We study the spectrum of confining strings in SU(3) pure gauge theory, by
means of lattice Monte Carlo simulations, using torelon operators in different
representations of the gauge group. Our results provide direct evidence that
the string spectrum is according to predictions based on -ality. Torelon
correlations in the rank-2 symmetric channel appear to be well reproduced by a
two-exponential picture, in which the lowest state is given by the fundamental
string , the heavier string state is such that the ratio
is approximately given by the Casimir ratio , and the torelon has a much smaller overlap with the
lighter fundamental string state.Comment: 7 pages, 2 figure
The normal-to-planar superfluid transition in Helium 3
We study the nature of the Helium-3 superfluid transition from the normal to
the planar phase, which is expected to be stabilized by the dipolar
interactions. We determine the RG flow of the corresponding
Landau-Ginzburg-Wilson theory by exploiting two fixed-dimension perturbative
schemes: the massive zero-momentum scheme and the minimal-subtraction scheme
without expansion. The analysis of the corresponding six-loop and
five-loop series shows the presence of a stable fixed point in the relevant
coupling region. Therefore, we predict the transition to be continuous. We also
compute critical exponents. The specific-heat exponent is estimated as
, while the magnetic susceptibility and magnetization
exponents and for Helium 3 are ,
.Comment: 19 pages, 4 fig
Bone mineral density in thalassemic children: a Brazilian experience
Osteoporosis is characterized by low bone mass and disruption of bone architecture, resulting in greater bone fragility with increased risk of fractures. Bone disease is an important cause of morbidity in beta thalassemia major patients. Osteoporosis has been described extensively in adult thalassemia. However, there are no studies describing Brazilian thalassemic children. We evaluated eleven patients with beta thalassemia major (median age of 10.0 years, range from 5 to 12 years) and twenty-four healthy children (median age of 9.5 years, range from 6 to 12 years), using dual X-ray absorptiometry to assess bone mineral density (BMD). Analysis of biochemical markers such as serum ferritin concentration, ionized calcium, alkaline phosphatase, phosphorus, albumin, prothrombin time and factor V was performed. The height was very different between the groups, p<0.05. The thalassemic patients showed significantly lower BMD (median 0.61 g/cm²) than control subjects (median 0.69 g/cm²) - p < 0.05. The relevant bone loss in the majority of thalassemic children studied emphasizes the need for identification and appropriate treatment of osteopenia, thereby reducing the morbidity of these patients. This is the first study described in the literature that determined bone mineral loss in Brazilian thalassemic children.A osteoporose, caracterizada por aumento da fragilidade óssea e suscetibilidade a fraturas, é inversamente proporcional ao pico de massa óssea adquirido na infância. Por outro lado, a doença óssea é uma importante causa de morbidade em pacientes portadores de beta-talassemia maior (TM). Apesar de intensamente descrita em pacientes talassêmicos adultos, não existem estudos sobre as alterações de densidade óssea em crianças talassêmicas brasileiras. Foram avaliados 11 pacientes (idade mediana de 10,0, variando de 5 a 12 anos), portadores de TM, e 24 crianças (idade mediana de 9,5, variando de 6 a 12 anos) saudáveis, utilizando medida de emissão dupla de raios-X para avaliar a densidade mineral óssea (DMO). A análise de marcadores bioquÃmicos tais como concentração de ferritina sérica, cálcio ionizado, fosfatase alcalina, fósforo, albumina, tempo de protrombina e fator V foi realizada. A estatura foi significativamente diferente entre os dois grupos estudados, p<0,05. Os pacientes talassêmicos mostraram valores significativamente inferiores de DMO (mediana 0,61 g/cm²) quando comparados aos indivÃduos controles (mediana 0,69 g/cm²), p < 0,05. A relevante perda óssea encontrada na maioria das crianças talassêmicas estudadas reforça a necessidade de identificação e tratamento adequado da osteopenia, reduzindo a morbidade destes indivÃduos. Este é o primeiro estudo, descrito na literatura, que avalia a DMO em crianças talassêmicas brasileiras.UNIFESP-EPMUniversidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMUNIFESP, EPMSciEL
Strong coupling expansion of chiral models
A general precedure is outlined for an algorithmic implementation of the
strong coupling expansion of lattice chiral models on arbitrary lattices. A
symbolic character expansion in terms of connected values of group integrals on
skeleton diagrams may be obtained by a fully computerized approach.Comment: 2 pages, PostScript file, contribution to conference LATTICE '9
Irrelevant operators in the two-dimensional Ising model
By using conformal-field theory, we classify the possible irrelevant
operators for the Ising model on the square and triangular lattices. We analyze
the existing results for the free energy and its derivatives and for the
correlation length, showing that they are in agreement with the conformal-field
theory predictions. Moreover, these results imply that the nonlinear scaling
field of the energy-momentum tensor vanishes at the critical point. Several
other peculiar cancellations are explained in terms of a number of general
conjectures. We show that all existing results on the square and triangular
lattice are consistent with the assumption that only nonzero spin operators are
present.Comment: 32 pages. Added comments and reference
Renormalised four-point coupling constant in the three-dimensional O(N) model with N=0
We simulate self-avoiding walks on a cubic lattice and determine the second
virial coefficient for walks of different lengths. This allows us to determine
the critical value of the renormalized four-point coupling constant in the
three-dimensional N-vector universality class for N=0. We obtain g* =
1.4005(5), where g is normalized so that the three-dimensional
field-theoretical beta-function behaves as \beta(g) = - g + g^2 for small g. As
a byproduct, we also obtain precise estimates of the interpenetration ratio
Psi*, Psi* = 0.24685(11), and of the exponent \nu, \nu = 0.5876(2).Comment: 16 page
- …