Investigating stellar-mass black hole kicks

We investigate whether stellar-mass black holes have to receive natal kicks in order to explain the observed distribution of low-mass X-ray binaries containing black holes within our Galaxy. Such binaries are the product of binary evolution, where the massive primary has exploded forming a stellar-mass black hole, probably after a common envelope phase where the system contracted down to separations of order 10-30 Rsun. We perform population synthesis calculations of these binaries, applying both kicks due to supernova mass-loss and natal kicks to the newly-formed black hole. We then integrate the trajectories of the binary systems within the Galactic potential. We find that natal kicks are in fact necessary to reach the large distances above the Galactic plane achieved by some binaries. Further, we find that the distribution of natal kicks would seem to be similar to that of neutron stars, rather than one where the kick velocities are reduced by the ratio of black hole to neutron-star mass (i.e. where the kicks have the same momentum). This result is somewhat surprising; in many pictures of stellar-mass black-hole formation, one might have expected black holes to receive kicks having the same momentum (rather than the same speed) as those given to neutron stars.Comment: 13 pages, 8 figures, 4 tables. Accepted for publication in MNRA

NEETs in Latin America and the Caribbean: Skills, Aspirations, and Information

This paper studies the role of cognitive skills, socioemotional skills, aspirations and expectations on the likelihood of being NEET (not in education, employment or training) using a novel sample of 15 to 24 year old residents of seven Latin American and Caribbean countries. After controlling for sociodemographic household conditions, we find that numeracy and literacy skills, core self‐evaluation, extraversion and educational aspirations are robust correlates of being NEET. We also find cross country heterogeneity. That is, in some countries, passion and perseverance for long‐term goals, neuroticism and labour market information biases are additional factors associated with being NEET

The ePetri dish, an on-chip cell imaging platform based on subpixel perspective sweeping microscopy (SPSM)

We report a chip-scale lensless wide-field-of-view microscopy imaging technique, subpixel perspective sweeping microscopy, which can render microscopy images of growing or confluent cell cultures autonomously. We demonstrate that this technology can be used to build smart Petri dish platforms, termed ePetri, for cell culture experiments. This technique leverages the recent broad and cheap availability of high performance image sensor chips to provide a low-cost and automated microscopy solution. Unlike the two major classes of lensless microscopy methods, optofluidic microscopy and digital in-line holography microscopy, this new approach is fully capable of working with cell cultures or any samples in which cells may be contiguously connected. With our prototype, we demonstrate the ability to image samples of area 6 mm × 4 mm at 660-nm resolution. As a further demonstration, we showed that the method can be applied to image color stained cell culture sample and to image and track cell culture growth directly within an incubator. Finally, we showed that this method can track embryonic stem cell differentiations over the entire sensor surface. Smart Petri dish based on this technology can significantly streamline and improve cell culture experiments by cutting down on human labor and contamination risks

Measurement of the Permanent Electric Dipole Moment of the 129^{129}Xe Atom

We report on a new measurement of the CP-violating permanent Electric Dipole Moment (EDM) of the neutral $^{129}$Xe atom. Our experimental approach is based on the detection of the free precession of co-located nuclear spin-polarized $^3$He and $^{129}$Xe samples. The EDM measurement sensitivity benefits strongly from long spin coherence times of several hours achieved in diluted gases and homogeneous weak magnetic fields of about 400~nT. A finite EDM is indicated by a change in the precession frequency, as an electric field is periodically reversed with respect to the magnetic guiding field. Our result, $\left(-4.7\pm6.4\right)\cdot 10^{-28}$ ecm, is consistent with zero and is used to place a new upper limit on the $^{129}$Xe EDM: $|d_\text{Xe}|<1.5 \cdot 10^{-27}$ ecm (95% C.L.). We also discuss the implications of this result for various CP-violating observables as they relate to theories of physics beyond the standard model

Autologous US-guided PRP injection versus US-guided focal extracorporeal shock wave therapy for chronic lateral epicondylitis: A minimum of 2-year follow-up retrospective comparative study.

PURPOSE: To compare the efficacy of two independent groups of patients treated with ultrasound (US)-guided extracorporeal shock wave (ESW) therapy and with US-guided injection of platelet-rich plasma (PRP) for chronic lateral epicondylitis (LE) with a minimum of 2-year follow-up. METHODS: We retrospectively evaluated 63 patients treated for chronic LE (31 patients with autologous US-guided PRP injection and 32 patients with US-guided focal ESW therapy) from 2009 to 2014. All the patients were evaluated by means of Roles-Maudsley (RM) score, quick Disabilities of Arm, Shoulder, and Hand (QuickDASH) score, visual analogic scale (VAS) and patient-rated tennis elbow evaluation (PRTEE) to retrospectively assess the pain relief, level of activity, the self-reported function and subjective satisfaction at minimum of 2-year follow-up. RESULTS: Both US-guided autologous PRP injection and US-guided focal ESW administration proved effective in chronic LE with significant improvement in the QuickDASH, VAS, RM and PRTEE scores ( p &lt; 0.0001). No adverse effects or complications were recorded in any groups. No differences were found in recurrence rate and final results of the QuickDASH, VAS, RM and PRTEE scores between the two groups ( p &gt; 0.05). The mean time between treatment and symptom resolution was significantly shorter for the PRP treatment ( p = 0.0212); furthermore, the mean time to return to the normal activities was quicker for PRP group ( p = 0.0119). CONCLUSION: Both PRP injection and ESW therapy are feasible and safe options for the treatment of chronic LE with low risk of complications and with good long-term follow-up results. US-guided PRP injection has quick efficacy when compared with US-guided focal ESW therapy

Local-scale forcing effects on wind flows in an urban environment: Impact of geometrical simplifications

Wind flow in urban areas is strongly affected by the urban geometry. In the last decades most of the geometries used to reproduce urban areas, both in wind-tunnel (WT) tests and Computational Fluid Dynamics (CFD) simulations, were simplified compared to reality in order to limit experimental effort and computational costs. However, it is unclear to which extent these geometrical simplifications can affect the reliability of the numerical and experimental results. The goal of this paper is to quantify the deviations caused by geometrical simplifications. The case under study is the district of Livorno city (Italy), called \ue2\u80\u9cQuartiere La Venezia\ue2\u80\u9d. The 3D steady Reynolds-averaged Navier-Stokes (RANS) simulations are solved, first for a single block of the district, then for the whole district. The CFD simulations are validated with WT tests at scale 1:300. Comparisons are made of mean wind velocity profiles between WT tests and CFD simulations, and the agreement is quantified using four validation metrics (FB, NMSE, R and FAC1.3). The results show that the most detailed geometry provides improved performance, especially for wind direction \uce\ub1 = 240\uc2\ub0 (22% difference in terms of FAC1.3)

Full Micromagnetic Numerical Simulations of Thermal Fluctuations

Thermal fluctuations for fine ferromagnetic particles are studied with the full micromagnetic analysis based on numerical integration of the spatially discretized Langevin-Landau-Lifshitz equation. These results can be used as a basis for the formulation of a standard problem to test the implementation of thermal fluctuations in numerical micromagnetic codes. To this end an example of micromagnetic analysis of thermal fluctuations in an ellipsoidal magnetic nanoparticle is presented

Microplastics in commercial bivalves harvested from intertidal seagrasses and sandbanks in the Ria Formosa lagoon, Portugal

Through seafood consumption, microplastic (MP) pollution is potentially threatening human health. Commercial bivalves in particular are a cause of major concern because their filter-feeding activity directly exposes them to MP in the water column and they are then ingested by humans. Here, we provide a quantitative and qualitative baseline data on MP content in the soft tissues of three commercially important bivalves (Ruditapes decussatus, Cerastoderma spp. and Polititapes spp.) collected in Ria Formosa lagoon, southern Portugal. The abundance of MPs (items per soft tissue weight) did not significantly differ among species. On average, R. decussatus exhibited the highest MP abundance (on average, 18.4 +/- 21.9 MP items g(-1) WW), followed by Cerastoderma spp. (11.9 +/- 5.5 MP items g(-1) WW) and Polititapes spp. (10.4 +/- 10.4 MP items g(-1) WW). Overall, 88% of the MPs found were synthetic fibres, the majority of which were blue (52%). Size categories >0.1-1 mm and >1-5 mm were the most common (60% and 34% respectively). The most represented polymers were polyethylene (PE) and polystyrene (PS). The unexpectedly high number of MPs recorded in the three commercially exploited species suggests that this semi-closed lagoon system is experiencing a higher anthropogenic pressure than are open coastal systems.Portuguese Foundation for Science and Technology: PTDC/MAR-EST/3223/2014 IF/01413/2014/CP1217/CT0004 UIDB/04326/2020 SFRH/BPD/119344/2016info:eu-repo/semantics/publishedVersio