1,244 research outputs found
Synchronization of delayed fluctuating complex networks
In this communication we present some of our recent results on the synchronization properties of directed delay-coupled networks of a small-world type, whose topology changes with time. Our simulations of a network of non-linear elements show that a random change of topology enhances the stability of a synchronized state, depending on the interplay between different time-scales in the dynamics. The results are analytically explained in the linear limit, where the dynamics is expressed in terms of an effective connectivity matrix. In the limit of fast network fluctuations, this effective connectivity is given by the arithmetic mean of the temporal adjacency matrices. When the coupling topology changes slowly, the effective adjacency matrix is given by the geometric mean. The transition between both regimes is numerically studied for linear network elements
Magnetic inhomogeneities in the quadruple perovskite manganite [Y_{2-x}Mn_{x}] Mn_{6}O_{12}
A combination of competing exchange interactions and substitutional disorder gives rise to magnetic inhomogeneities in the [Y_{2-x}Mn_{x}]Mn_{6}O-{12}x = 0.23 and 0.16 quadruple perovskite manganites. Our neutron powder scattering measurements show that both the x=0.23 and 0.16 samples separate into two distinct magnetic phases; below T_{1} = 120 ± 10 K the system undergoes a transition from a paramagnetic phase to a phase characterized by short-range antiferromagnetic clusters contained in a paramagnetic matrix, and below T2â65 K the system is composed of well-correlated long-range collinear ferrimagnetic order, punctuated by short-range antiferromagnetic clusters. A sharp increase in the antiferromagnetic phase fraction is observed below â33 K, concomitant with a decrease in the ferrimagnetic phase fraction. Our results demonstrate that the theoretically proposed antiferromagnetic phase is stabilized in the [Y_{2-x}Mn_{x}] Mn_{6}O_{12} manganites in the presence of dominant B-B exchange interactions, as predicted
Next generation microbiological risk assessment: opportunities of whole genome sequencing (WGS) for foodborne pathogen surveillance, source tracking and risk assessment
Challenges of poor surface water drainage and wastewater management in refugee camps
Since refugee camps are meant to be temporary and setting them up usually require urgency, little attention has been given to provision of surface water drainage and to a lesser extent wastewater management. As the population of refugees in these camps continues to grow, the effectiveness of drainage infrastructure continues to diminish. In addition, availability of sufficient safe drinking water and wastewater management have become difficult in the refugee camps across the world. The present situation in refugee camps across the world, such as flooding and outbreak of water-related diseases in South Sudan refugee camps, has made the need for sustainable approach to solving the problems to be very urgent. One sustainable way of solving the problems of flooding and outbreak of diseases in refugee camps is to provide effective drainage and wastewater infrastructure that ensures all the wastewater are properly collected, treated and reused for various purposes such as agriculture, drinking, laundry and other relevant uses. This paper therefore presents the current state of drainage and wastewater management in two refugee camps and propose low-cost technologies for stormwater management, wastewater collection, treatment and potential reuse, suitable for these refugee camps
Enabling PAT in insect cell bioprocesses: A monitoring toolbox for rAAV production
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Finite-size scaling study of the liquidâvapour critical point of dipolar square-well fluids
Viral Hepatitis and Rapid Diagnostic Test Based Screening for HBsAg in HIV-infected Patients in Rural Tanzania.
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Co-infection with hepatitis B virus (HBV) is highly prevalent in people living with HIV in Sub-Saharan Africa. Screening for HBV surface antigen (HBsAg) before initiation of combination antiretroviral therapy (cART) is recommended. However, it is not part of diagnostic routines in HIV programs in many resource-limited countries although patients could benefit from optimized antiretroviral therapy covering both infections. Screening could be facilitated by rapid diagnostic tests for HBsAg. Operating experience with these point of care devices in HIV-positive patients in Sub-Saharan Africa is largely lacking. We determined the prevalence of HBV and Hepatitis C virus (HCV) infection as well as the diagnostic accuracy of the rapid test device Determine HBsAg in an HIV cohort in rural Tanzania. Prospectively collected blood samples from adult, HIV-1 positive and antiretroviral treatment-naïve patients in the Kilombero and Ulanga antiretroviral cohort (KIULARCO) in rural Tanzania were analyzed at the point of care with Determine HBsAg, a reference HBsAg EIA and an anti-HCV EIA. Samples of 272 patients were included. Median age was 38 years (interquartile range [IQR] 32-47), 169/272 (63%) subjects were females and median CD4+ count was 250 cells/”L (IQR 97-439). HBsAg was detected in 25/272 (9.2%, 95% confidence interval [CI] 6.2-13.0%) subjects. Of these, 7/25 (28%) were positive for HBeAg. Sensitivity of Determine HBsAg was rated at 96% (95% CI 82.8-99.6%) and specificity at 100% (95% CI, 98.9-100%). Antibodies to HCV (anti-HCV) were found in 10/272 (3.7%, 95% CI 2.0-6.4%) of patients. This study reports a high prevalence of HBV in HIV-positive patients in a rural Tanzanian setting. The rapid diagnostic test Determine HBsAg is an accurate assay for screening for HBsAg in HIV-1 infected patients at the point of care and may further help to guide cART in Sub-Saharan Africa
Psychophysiological effects of massage-myofascial release after exercise: a randomized sham-control study
This is a copy of an article published in the Journal of Alternative and Complementary Medicine © 2008 Mary Ann Liebert, Inc.; Journal of Alternative and Complementary Medicine is available online at: http://online.liebertpub.com.Objective: The aim of this study was to evaluate the effect of massage on neuromuscular recruitment, mood
state, and mechanical nociceptive threshold (MNT) after high-intensity exercise.
Design: This was a prospective randomized clinical trial using between-groups design.
Setting: The study was conducted at a university-based sports medicine clinic.
Participants: Sixty-two (62) healthy active students age 18â26 participated.
Interventions: Participants, randomized into two groups, performed three 30-second Wingate tests and immediately received whole-body massage-myofascial induction or placebo (sham ultrasound/magnetotherapy)
treatment. The duration (40 minutes), position, and therapist were the same for both treatments.
Main outcome measures: Dependent variables were surface electromyography (sEMG) of quadriceps, profile
of mood states (POMS) and mechanical nociceptive threshold (MNT) of trapezius and masseter muscles. These
data were assessed at baseline and after exercise and recovery periods.
Results: Generalized estimating equations models were performed on dependent variables to assess differences
between groups. Significant differences were found in effects of treatment on sEMG of Vastus Medialis (VM)
(p 0.02) and vigor subscale (p 0.04). After the recovery period, there was a significant decrease in electromyographic (EMG) activity of VM (p 0.02) in the myofascial-release group versus a nonsignificant increase
in the placebo group (p 0.32), and a decrease in vigor (p 0.01) in the massage group versus no change in
the placebo group (p 0.86).
Conclusions: Massage reduces EMG amplitude and vigor when applied as a passive recovery technique after
a high-intensity exercise protocol. Massage may induce a transient loss of muscle strength or a change in the
muscle fiber tensionâlength relationship, influenced by alterations of muscle function and a psychological state
of relaxation.The trial was funded by a research project grant (11/UPB10/06) from the Spanish Higher Sports Council
The effect of microencapsulated phase change materials on the rheology of geopolymer and Portland cement mortars
The effect of microencapsulated phaseâchange materials (MPCM) on the rheological properties of preâset geopolymer and Portland cement mortars was examined. Microcapsules with hydrophilic and hydrophobic shells were compared. The shear rate dependency of the viscosities fitted well to a double Carreau model. The zero shear viscosities are higher for geopolymer mortar, illustrating poorer workability. The time evolution of the viscosities was explored at shear rates of 1 and 10 sâ1. New empirical equations were developed to quantify the timeâdependent viscosity changes. The highest shear rate disrupted the buildup of the mortar structures much more than the lower shear rate. Microcapsules with a hydrophobic shell affect the rheological properties much less than the microcapsules with a hydrophilic shell, due to the higher water adsorption onto the hydrophilic microcapsules. Shear forces was found to break down the initial structures within geopolymer mortars more easily than for Portland cement mortars, while the geopolymer reaction products are able to withstand shear forces better than Portland cement hydration products. Initially, the viscosity of geopolymer mortars increases relatively slowly during due to formation of geopolymer precursors; at longer times, there is a steeper viscosity rise caused by the development of a 3Dâgeopolymer network. Disruption of agglomerates causes the viscosities of portland cement mortars to decrease during the first few minutes, after which the hydration process (increasing viscosities) competes with shearâinduced disruption of the structures (decreasing viscosities), resulting in a complex viscosity behavior.publishedVersio
Experimental GHZ Entanglement beyond Qubits
The Greenberger-Horne-Zeilinger (GHZ) argument provides an all-or-nothing
contradiction between quantum mechanics and local-realistic theories. In its
original formulation, GHZ investigated three and four particles entangled in
two dimensions only. Very recently, higher dimensional contradictions
especially in three dimensions and three particles have been discovered but it
has remained unclear how to produce such states. In this article we
experimentally show how to generate a three-dimensional GHZ state from
two-photon orbital-angular-momentum entanglement. The first suggestion for a
setup which generates three-dimensional GHZ entanglement from these entangled
pairs came from using the computer algorithm Melvin. The procedure employs
novel concepts significantly beyond the qubit case. Our experiment opens up the
possibility of a truly high-dimensional test of the GHZ-contradiction which,
interestingly, employs non-Hermitian operators.Comment: 6+6 pages, 8 figure
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