Strong Gravitational Lensing and Dark Energy

We investigate the statistics of gravitational lenses in flat, low-density cosmological models with different cosmic equations of state w. We compute the lensing probabilities as a function of image separation \theta using a lens population described by the mass function of Jenkins et al. and modeled as singular isothermal spheres on galactic scales and as Navarro, Frenk & White halos on cluster scales. It is found that COBE-normalized models with w > - 0.4 produce too few arcsecond-scale lenses in comparison with the JVAS/CLASS radio survey, a result that is consistent with other observational constraints on w. The wide-separation (\theta > 4'') lensing rate is a particularly sensitive probe of both w and the halo mass concentration. The absence of these systems in the current JVAS/CLASS data excludes highly concentrated halos in w < -0.7 models. The constraints can be improved by ongoing and future lensing surveys of > 10^5 sources.Comment: 12 pages, 3 figures. Accepted for publication in ApJ Letter

Strong Gravitational Lensing and Dark Energy Complementarity

In the search for the nature of dark energy most cosmological probes measure simple functions of the expansion rate. While powerful, these all involve roughly the same dependence on the dark energy equation of state parameters, with anticorrelation between its present value w_0 and time variation w_a. Quantities that have instead positive correlation and so a sensitivity direction largely orthogonal to, e.g., distance probes offer the hope of achieving tight constraints through complementarity. Such quantities are found in strong gravitational lensing observations of image separations and time delays. While degeneracy between cosmological parameters prevents full complementarity, strong lensing measurements to 1% accuracy can improve equation of state characterization by 15-50%. Next generation surveys should provide data on roughly 10^5 lens systems, though systematic errors will remain challenging.Comment: 7 pages, 5 figure

Quantitative ultrasound to monitor the vascular response to tocilizumab in giant cell arteritis.

OBJECTIVES To characterize the effect of ultra-short glucocorticoids followed by Tocilizumab monotherapy on the intima-media thickness (IMT) in GCA. METHODS 18 GCA patients received 500mg methylprednisolone intravenously on days 0-2, followed by Tocilizumab (8mg/kg) intravenously on day 3 and thereafter weekly subcutaneous Tocilizumab injections (162 mg) over 52 weeks. Ultrasound of temporal (TA), axillary (AA) and subclavian (SA) arteries was performed at baseline, on days 2-3, at week 4, 8, 12, 24 and 52. The largest IMT of all segments and IMT at landmarks of AA/SA were recorded. IMT was scaled by mean normal values and averaged. Each segment was classified according to diagnostic cut-offs. RESULTS 16 patients had TA and 6 had extracranial large artery involvement. The IMT showed a sharp decline on day 2/3 in the TA and AA/SA. In TA, this was followed by an increase to baseline levels at week 4 and a subsequent slow decrease, which was paralleled by decreasing symptoms and achievement of clinical remission. The AA/SA showed a new signal of vasculitis at week 4 in three patients with an IMT increase up to week 8. CONCLUSIONS Glucocorticoid pulse therapy induced a transient decrease of the IMT in TA and AA/SA. Tocilizumab monotherapy resulted in a slow and steady decrease in IMT of the TA and a smaller and delayed effect on the AA/SA. The data strongly support a remission-inducing effect of Tocilizumab and argue for an important role of ultrasound in monitoring disease activity in GCA

Early Improvement in Glycemic Metabolism after Laparoscopic Sleeve Gastrectomy in Obese Patients -A Prospective Study

Rezumat Ameliorarea rapidã a metabolismului glucidic dupã gastrectomia longitudinalã laparoscopicã la pacienåii cu obezitate -studiu prospectiv Introducere: Conform Organizaåiei Mondiale a Sãnãtãåii, existau în 2014 peste 600 de milioane de adulåi cu obezitate (mai mult decât dublu faåã de anul 1980) care prezintã un risc crescut de dezvoltare a sindromului metabolic, deci inclusiv pentru diabetul zaharat de tip 2. Datoritã controlului slab glicemic în urma tratamentului conservator al DZ tip 2, chirurgia metabolicã a fost capabilã sã câaetige un rol important în managementul pacientului cu DZ tip 2 aei obezitate, cu remisii sau îmbunãtãåiri semnificative raportate în literatura de specialitate. Obiectiv: studierea efectelor gastrectomiei longitudinale laparoscopice (LSG) asupra metabolismului glucidic la pacienåii cu obezitate, cu sau fãrã DZ tip 2. Metodã: 60 de pacienåi consecutivi, operaåi în spitalul Ponderas pentru obezitate prin gastrectomie longitudinalã laparoscopicã, au fost incluaei într-un studiu prospectiv, în perioada FebruarieMartie 2013. IMC-ul (indicele de masã corporalã), circumferinåã abdominalã aei parametrii glicemici au fost studiaåi pre-operator, la 10 zile aei 6 luni postoperator. Rezultate: controlul glicemic a fost semnificant îmbunãtãåit începând cu ziua 10 postoperatorie. Imbunãtãåiri semnificative statistic au fost notate la 6 luni postoperator în valorile IMCului (p&lt;0.0001), circumferinåa abdominalã (p&lt;0.0001), glicemie (p&lt;0.0001), insulinemie (p&lt;0.0001), peptid C (p&lt;0.0001) aei HOMA. Concluzii: o îmbunãtãåire rapidã a metabolismului glucidic, atât la pacienåii cu obezitate aei DZ tip 2 cât aei la cei fãrã DZ tip 2, se regãseaete înaintea scãderii ponderale semnificative (10 zile postoperator). La 6 luni postoperator, când se asociazã aei o scãdere ponderalã semnificativã, atât pacienåii diabetici cât aei cei nediabetici prezintã o îmbunãtãåire suplimentarã a metabolismului glicemic, care poate susåine ideea ca gastrectomia longitudinalã laparoscopicã este o metodã eficientã pentru tratamentul pacienåilor cu obezitate aei sindrom metabolic. Aceste modificãri benefice pot explica atât remisia DZ tip 2 dar aei prevenåia acestuia la pacienåii cu obezitate supuaei tratamentului chirurgical metabolic. Cuvinte cheie: obezitate, metabolism glucidic, gastrectomie longitudinalã laparoscopicã, remisia aei prevenåia diabetului zaharat tip 2 Abstract Background: according to W.H.O. in 2014 more than 600 million adults were obese, (more than doubled since 1980), and face a major risk for the onset of metabolic syndrome, including T2DM. Due to the poor control of glycemic imbalance for the conservative treatment of T2DM, the metabolic surgery was able to gain an important role in modern management of T2DM, with significant reported improvements or remissions for these patients. Objective: to study the effects of laparoscopic sleeve gastrec- BMI, waist circumference and glycemic parameters were studied at the moment of entering the study, 10 days after surgery and at 6 months follow up. Results: the glycemic control was significantly improved starting with postoperative day 10. Statistically significant improvements were noticed after six months postoperatively in BMI values (p&lt;0,0001), waist circumference (p&lt;0,0001), glycemic levels (p&lt;0,0001), insulin (p&lt;0,0001), C-peptide (p&lt;0,0001) and HOMA. Conclusions: a rapid induced improvement of glucose metabolism in both diabetic and non-diabetic patients occurs before a significant weight loss (POD 10). At 6 months, when associated with an important weight loss, both diabetic and non-diabetic patients present a furthermore improvement in glycemic metabolism, that enables us to consider that sleeve gastrectomy is an efficient method for a sustained improvement in the metabolic status of patients with obesity. These beneficial changes that can explain the remission of T2DM can also explain the prevention of T2DM after metabolic surgery

Evaluating the approximation of the affinity laws and improving the efficiency estimate for variable speed pumps

Affinity laws relate to the characteristics of pumps operating at different speeds, and in a water distribution context, are usually used to predict the pump curve of variable speed pumps (VSPs). VSPs can adjust the pump curve to meet the network requirements more efficiently with resultant savings of energy. The estimation of the effectiveness of a VSP is based on hydraulic simulations, in which the behavior of VSPs is described using the affinity laws. The affinity laws, however, contain approximations because they do not take into account factors that do not scale with velocity. In particular, the approximation inherent in the affinity law that computes power and efficiency can produce a misleading result, especially for small-size pumps. The research reported in this paper estimates the error in efficiency for a wide range of pump sizes and tests the use of a previously proposed formula as an alternative to the affinity law. Results show that a better estimation can be achieved for the efficiency of small- and medium-size pumps. Moreover the formula can be easily implemented in hydraulic solvers. © 2013 American Society of Civil Engineers.Angus R. Simpson and Angela March

Time-Varying Dark Energy Constraints From the Latest SN Ia, BAO and SGL

Based on the latest SNe Ia data provided by Hicken et al. (2009) with using MLCS17 light curve fitter, together with the Baryon Acoustic Oscillation(BAO) and strong gravitational lenses(SGL), we investigate the constraints on the dark energy equation-of-state parameter $w$ in the flat universe, especially for the time-varying case $w(z)=w_0+w_zz/(1+z)$. The constraints from SNe data alone are found to be: (a) $(\Omega_M, w)=(0.358, -1.09)$ as the best-fit results; (b) $(w_0, w_z)=(-0.73^{+0.23}_{-0.97}, 0.84^{+1.66}_{-10.34})$ for the two parameters in the time-varying case after marginalizing the parameter $\Omega_M$; (c) the likelihood of parameter $w_z$ has a high non-Gaussian distribution; (d) an extra restriction on $\Omega_M$ is necessary to improve the constraint of the SNe Ia data on the parameters ($w_0$, $w_z$). A joint analysis of SNe Ia data and BAO is made to break the degeneracy between $w$ and $\Omega_M$, and leads to the interesting maximum likelihoods $w_0 = -0.94$ and $w_z = 0$. When marginalizing the parameter $\Omega_M$, the fitting results are found to be $(w_0, w_z)=(-0.95^{+0.45}_{-0.18}, 0.41^{+0.79}_{-0.96})$. After adding the splitting angle statistic of SGL data, a consistent constraint is obtained $(\Omega_M, w)=(0.298, -0.907)$ and the constraints on time-varying dark energy are further improved to be $(w_0, w_z) = (-0.92^{+0.14}_{-0.10}, 0.35^{+0.47}_{-0.54})$, which indicates that the phantom type models are disfavored.Comment: 24 pages, 9 figures, to be published in JCA

Prospects for the Improvement of Energy Performance in Agroindustry Using Phase Change Materials

This work was partially supported by the Fundação para a Ciência e Tecnologia, UIDB/00066/2020 (CTS – Center of Technology and Systems).The use of Phase Change Materials (PCMs), able to store latent heat, represents an opportunity to improve energy efficiency in the agroindustry by means of thermal energy storage. PCMs provide higher energy density then sensible heat storage mediums, thus paving the way to multiple applications, like supporting the integration of renewables or allowing for new storage architectures, decentralized and directly installed in the chain production equipment, creating e.g. the opportunity to recover and value low-grade operational heat sub-products. Such new and decentralized architecture, not currently applied in agroindustry, is proposed in this work. A chocolate tempering machine using an organic PCM is conceived and analyzed using ANSYS Fluent software for computational fluid dynamics simulations, comparing the main aspects in the storage capacity and discharging process with a conventional sensitive heat storage solution that uses water. PCMs allows improving the stored energy, keeping the chocolate in the working temperature after being tempered for more than four times longer than using only hot water. If the PCMs are charged by renewables, the self-consumption ratio can be improved while providing energy flexibility to the user.authorsversionpublishe