332 research outputs found
Industrial clusters and economic performance in Brazil
Industrial clusters, which are commonly targeted to receive financial support allocated to locally based development projects, are seen as an effective industrial policy tool for improving productivity and generating employment. Nevertheless, identifying clusters and assessing their economic performance is a challenge for policymakers. This paper aims to address this challenge by identifying the location of clusters based on neighbor relationships and specialization in Brazil and providing some insights on their effects on employment generation. The paper uses both Location Quotient and Local Indicator of Spatial Association to identify potential clusters in 27 industrial sectors in 5564 Brazilian municipalities. In addition, it uses annual municipal panel data for 2006-2009 to assess whether the presence of potential clusters is correlated with employment generation. The results show that clusters located in municipalities whose neighbors have similar industrial structures perform better than those that present industry specialization only
Violation of the Ikeda sum rule and the self-consistency in the renormalized quasiparticle random phase approximation and the nuclear double-beta decay
The effect of the inclusion of ground state correlations into the QRPA
equation of motion for the two-neutrino double beta () decay
is carefully analyzed. The resulting model, called renormalized QRPA (RQRPA),
does not collapse near the physical value of the nuclear force strength in the
particle-particle channel, as happens with the ordinary QRPA. Still, the
transition amplitude is only slightly less sensitive on
this parameter in the RQRPA than that in the plain QRPA. It is argued that this
fact reveals once more that the characteristic behaviour of the
transition amplitude within the QRPA is not an artifact of
the model, but a consequence of the partial restoration of the spin-isospin
symmetry. It is shown that the price paid for bypassing the collapse in
the RQRPA is the violation of the Ikeda sum rule.Comment: 16 pages, latex, 3 postscript figure
Defining postoperative stability in children with radial polydactyly
There is little fundamental data on paediatric metacarpophalangeal joint instability in radial polydactyly following surgical reconstruction. We evaluated 27 thumbs in a healthy paediatric population (Group A: eight girls and 19 boys with a mean age of 9.7 years (range 2.7-14.2)) and 12 thumbs following Wassel-IV reconstruction (Group B: eight girls and four boys with a mean age at follow-up of 10.6 years (range 2.7-13.2)). Metacarpophalangeal joint radial deviation, ulnar deviation on stress testing, interphalangeal joint and metacarpophalangeal joint alignment on posterior-anterior radiographs were measured and scored according to parameters defining joint instability. The aim of our study was to provide fundamental data on thumb metacarpophalangeal joint mobility patterns and alignment for further postoperative evaluations in children. The average ulnar deviation and radial deviation on stress testing of the healthy (Group A) metacarpophalangeal joints was 25 degrees (10 degrees-45 degrees) and 30 degrees (10 degrees-55 degrees), respectively. In the operated (Group B) thumbs, the ulnar deviation and radial deviation was greater at 35 degrees (10 degrees-55 degrees) and 30 degrees (10 degrees-70 degrees). Ulnar deviation (UD) of the proximal phalanx at the metacarpophalangeal joint on posterior-anterior radiographs was a mean of 10 degrees (range -10 degrees-30 degrees) in Group B;this was significantly greater than in Group A at a mean of 5 degrees (range -5-20 degrees) (p = 0.029). The mean radial alignment of the interphalangeal joint (distal phalanx relative to the proximal phalanx) was significantly higher in Group B (15 degrees) than Group A (0 degrees) (p = 0.221). In the literature on radial polydactyly, cut off values defining metacarpophalangeal joint instability in children range from 5 degrees to 20 degrees. According to our results, high but physiological metacarpophalangeal joint mobility of the thumb needs to be taken into consideration when evaluating children following reconstruction. Ulnar or radial deviation greater than 30 degrees, in combination with the lack of a definite end point on metacarpophalangeal joint stress testing, may be regarded as unstable. Based on our study on healthy paediatric and reconstructed thumbs, comparison of joint stability with the healthy contralateral hand is recommended in order to define pathological instability
Risk factor and high-risk place variations across different robbery targets in Denver, Colorado
Purpose
Risk Terrain Modeling (RTM) has been effectively used to spatially diagnose risk for crimes such as robbery, aggravated assault, and gun violence. An important contribution is to consider how risk differs across individual crimes and different target types. This study tests four different robbery target types in unique models to examine the potential for variation across significant risk factors and high-risk locations.
Methods
Using the online diagnostic software RTMDx, individual robbery models were run for four robbery target types in Denver, Colorado: commercial (businesses), carjacking (driver/vehicle), residential (home/dwelling), and street (pedestrians). A conjunctive analysis of case configurations was also conducted to determine the potential for spatial differences in high-risk places across target types.
Results
The results indicate that there is variation across risk factors, and observable differences in risk factor spatial influence, operationalization and relative risk values in each target model. Convenience stores were the only risk factor significantly associated with every target type and the conjunctive analysis matrix found that very few places were high-risk for all four robbery types.
Conclusions
The findings suggest different target types should be analyzed individually and interventions should focus on different high-risk locations and be tailored to specific target types
Coherence lifetimes of excitations in an atomic condensate due to the thin spectrum
We study the quantum coherence properties of a finite sized atomic condensate
using a toy-model and the thin spectrum model formalism. The decoherence time
for a condensate in the ground state, nominally taken as a variational symmetry
breaking state, is investigated for both zero and finite temperatures. We also
consider the lifetimes for Bogoliubov quasi-particle excitations, and contrast
them to the observability window determined by the ground state coherence time.
The lifetimes are shown to exhibit a general characteristic dependence on the
temperature, determined by the thin spectrum accompanying the spontaneous
symmetry breaking ground state
Kvazičestična aproksimacija nasumnih faza bez urušavanja za dvojni beta raspad
We show how the longstanding problem of the collapse of the charge–exchange QRPA near the physical value of the force strength can be circumvented. This is done by including the effect of ground state correlations into the QRPA equations of motion. The corresponding formalism, called renormalized QRPA, is briefly outlined and its consequences are discussed in the framework of a schematic model for the two-neutrino double beta decay in the 100Mo → 100Ru system. The question of the conservation of the Ikeda sum rule is also addressed within the new formalism.Pokazuje se kako se može izbjeći tvrdokorni problem urušavanja kvazičestične aproksimacije nasumnih faza (QRPA) s nabojskom izmjenom za realne vrijednosti jakosti sila. To se postiže uključivanjem korelacije u osnovnom stanju u jednadžbe stanja QRPA. Raspravljaju se rezultati za shematski model dvoneutrinskog dvojnog beta raspada 100Mo → 100Ru. U okviru ovog formalizma također se raspravlja pitanje Ikedinog zbrojnog pravila
Effective Widths and Effective Number of Phonons of Multiphonon Giant Resonances
We discuss the origin of the difference between the harmonic value of the
width of the multiphonon giant resonances and the smaller observed value.
Analytical expressions are derived for both the effective width and the average
cross-section. The contribution of the Brink-Axel mechanism in resolving the
discrepancy is pointed out.Comment: 9 pages, 4 figure
Development of a microplate immunocapture (IC) RT-PCR assays for the detection of avian influenza virus (AIV) and infectious bronchitis virus (IBV).
Projeto/Plano de Ação: 11.11.11.111
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