5,212 research outputs found
On Resilient Behaviors in Computational Systems and Environments
The present article introduces a reference framework for discussing
resilience of computational systems. Rather than a property that may or may not
be exhibited by a system, resilience is interpreted here as the emerging result
of a dynamic process. Said process represents the dynamic interplay between the
behaviors exercised by a system and those of the environment it is set to
operate in. As a result of this interpretation, coherent definitions of several
aspects of resilience can be derived and proposed, including elasticity, change
tolerance, and antifragility. Definitions are also provided for measures of the
risk of unresilience as well as for the optimal match of a given resilient
design with respect to the current environmental conditions. Finally, a
resilience strategy based on our model is exemplified through a simple
scenario.Comment: The final publication is available at Springer via
http://dx.doi.org/10.1007/s40860-015-0002-6 The paper considerably extends
the results of two conference papers that are available at http://ow.ly/KWfkj
and http://ow.ly/KWfgO. Text and formalism in those papers has been used or
adapted in the herewith submitted pape
Invariant measures on multimode quantum Gaussian states
We derive the invariant measure on the manifold of multimode quantum Gaussian
states, induced by the Haar measure on the group of Gaussian unitary
transformations. To this end, by introducing a bipartition of the system in two
disjoint subsystems, we use a parameterization highlighting the role of
nonlocal degrees of freedom -- the symplectic eigenvalues -- which characterize
quantum entanglement across the given bipartition. A finite measure is then
obtained by imposing a physically motivated energy constraint. By averaging
over the local degrees of freedom we finally derive the invariant distribution
of the symplectic eigenvalues in some cases of particular interest for
applications in quantum optics and quantum information.Comment: 17 pages, comments are welcome. v2: presentation improved and typos
corrected. Close to the published versio
Therapy of Canine Hyperlipidemia with Bezafibrate.
BackgroundBezafibrate (BZF) is effective in the treatment of hypertriglyceridemia in human patients, but there are no data on its use in dogs.ObjectiveTo assess the safety of BZF in hyperlipidemic dogs and its efficacy in decreasing serum triglyceride (TG) and cholesterol (CHO) concentrations.AnimalsForty-six dogs, 26 females and 20 males, mean (±SD) age of 9 (±3) years, with TG ≥150 mg/dL (33 dogs also were hypercholesterolemic [>300 mg/dL]).MethodsProspective, uncontrolled clinical trial. Dogs were treated with bezafibrate once daily, using 200 mg tablets at a dosage of 4-10 mg/kg (depending on body weight). Serum TG and CHO concentrations and alanine aminotransferase (ALT) and creatine kinase (CK) activity before and after 30 days of treatment were compared.ResultsSixteen dogs (34.8%) had primary hyperlipidemia, and 30 dogs (65.2%) had secondary hyperlipidemia (including spontaneous hyperadrenocorticism [41.3%, n = 19/46], chronic treatment with glucocorticoids [10.8%, n = 5/46], and hypothyroidism [15.2%, n = 7/46]). After 30 days, serum TG concentration normalized (<150 mg/dL) in 42 dogs (91.3%) and CHO concentration normalized (<270 mg/dL) in 22 of 33 dogs (66.7%). There was no difference in baseline TG concentration between the primary and secondary hyperlipidemia subgroups, but the decrease in TG concentration after treatment was greater in the primary hyperlipidemia subgroup. No adverse effects were observed, but ALT activity decreased significantly after 30 days of treatment.Conclusions and clinical importanceOver 30 days, BZF was safe and effective in treatment of primary and secondary hyperlipidemia in dogs
Feynman graphs and the large dimensional limit of multipartite entanglement
We are interested in the properties of multipartite entanglement of a system
composed by -level parties (qudits).
Focussing our attention on pure states we want to tackle the problem of the
maximization of the entanglement for such systems. In particular we effort the
problem trying to minimize the purity of the system. It has been shown that not
for all systems this function can reach its lower bound, however it can be
proved that for all values of a can always be found such that the lower
bound can be reached.
In this paper we examine the high-temperature expansion of the distribution
function of the bipartite purity over all balanced bipartition considering its
optimization problem as a problem of statistical mechanics. In particular we
prove that the series characterizing the expansion converges and we analyze the
behavior of each term of the series as .Comment: 29 pages, 11 figure
Quality of institutions and productivity of State-Invested Enterprises: International evidence from major telecom companies
The quality of institutions is at the core of the differences in the growth of income and productivity of nations. A growing body of evidence shows how this is also true at the firm level. After taking stock of earlier theoretical and empirical literature on the efficiency of state-owned versus private enterprises, while we consider ownership as the core internal governance mechanism of firms, we add quality of government as a determinant of the external institutional environment. To disentangle the effect of internal and external institutions on firms' productivity, we use different sets of ownership and institutional environment indicators. After having identified the top 350 private, state-invested (i.e. partially state-owned)and state-owned enterprises in the telecommunications industry in EU28 and in more than 60 other countries between 2007 and 2015, we empirically investigate models of firms' productivity augmented with ownership and quality of government. Our findings suggest that, after controlling for the regulatory and competitive conditions at the country level, on average, public ownership has a negative impact on firm-level TFP. This effect is however mitigated by high external institutional quality and even reversed in some countries with a particularly favourable institutional environment
Quality of Life and psychopathology in adults who underwent Hematopoietic Stem Cell Transplantation (HSCT) in childhood: a qualitative and quantitative analysis.
Background: Patients who undergo pediatric Hematopoietic Stem Cell Transplantation (HSCT) may experience long-term psychological sequelae and poor Quality of Life (QoL) in adulthood. This study aimed to investigate subjective illness experience, QoL, and psychopathology in young adults who have survived pediatric HSCT.
Method: The study involved patients treated with HSCT in the Hematology-Oncology Department between 1984 and 2007. Psychopathology and QoL were investigated using the SCL-90-R and SF-36. Socio-demographic and medical information was also collected. Finally, participants were asked to write a brief composition about their experiences of illness and care. Qualitative analysis of the texts was performed using T-LAB, an instrument for text analysis that allows the user to highlight the occurrences and co-occurrences of lemma. Quantitative analyses were performed using non-parametric tests (Spearman correlations, Kruskal-Wallis and Mann-Whitney tests).
Results: Twenty-one patients (9 males) participated in the study. No significant distress was found on the SCL-90 Global Severity Index, but it was found on specific scales. On the SF-36, lower scores were reported on scales referring to bodily pain, general health, and physical and social functioning. All the measures were significantly (p < 0.05) associated with specific socio-demographic and medical variables (gender, type of pathology, type of HSCT, time elapsed between communication of the need to transplant and effective transplantation, and days of hospitalization). With regard to the narrative analyses, males focused on expressions related to the body and medical therapies, while females focused on people they met during treatment, family members, and donors. Low general health and treatment with autologous HSCT were associated with memories about chemotherapy, radiotherapy, and the body parts involved, while high general health was associated with expressions focused on gratitude (V-Test \ub1 1.96).
Conclusion: Pediatric HSCT survivors are more likely to experience psychological distress and low QoL in adulthood compared with the general population. These aspects, along with survivors' subjective illness experience, show differences according to specific medical and socio-demographic variables. Studies are needed in order to improve the care and long-term follow-up of these families
Entanglement of two blocks of spins in the critical Ising model
We compute the entropy of entanglement of two blocks of L spins at a distance
d in the ground state of an Ising chain in an external transverse magnetic
field. We numerically study the von Neumann entropy for different values of the
transverse field. At the critical point we obtain analytical results for blocks
of size L=1 and L=2. In the general case, the critical entropy is shown to be
additive when d goes to infinity. Finally, based on simple arguments, we derive
an expression for the entropy at the critical point as a function of both L and
d. This formula is in excellent agreement with numerical results.Comment: published versio
PARAMETRICAL ANALYSIS AND DIGITAL FABRICATION OF THIN SHELL STRUCTURES: THE IMPACT OF CONSTRUCTION TECHNIQUE ON THE RESULTING GEOMETRY OF THE GAUSSIAN VAULTS OF ELADIO DIESTE
Abstract. The objective of this article is to analyze the state-of-art regarding the construction process of the Gaussian Vaults of the Uruguayan civil engineer Eladio Dieste and to identify the elements that underlie the relationship between the constructive techniques and procedures within this specific structural typology and its resulting geometry. As complementary objectives, this research aims for the identification of the gaps in the registry of such constructive procedures. The essay focuses on the geometry of the Gaussian Vaults designed and built by Dieste, in a way that these rigid structural surfaces' geometry had their original construction drawings redrawn and analyzed from the perspective of its construction technique by means of the Parametrical Modelling and Digital Fabrication of case studies.</p
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