Different twins in the millisecond pulsar recycling scenario: optical polarimetry of PSR J1023+0038 and XSS J12270-4859

We present the first optical polarimetric study of the two transitional pulsars PSR J1023+0038 and XSS J12270-4859. This work is focused on the search for intrinsical linear polarisation (LP) in the optical emission from the two systems. We carried out multiband optical and NIR photo-polarimetry of the two systems using the ESO NTT at La Silla (Chile), equipped with the EFOSC2 and the SOFI instruments. XSS J12270-4859 was observed during its radio-pulsar state; we did not detect LP in all bands, with 3 sigma upper limits of, e.g., 1.4% in the R-band. We built the NIR-optical averaged spectral energy distribution (SED) of the system, that could be well described by an irradiated black body with radius $R_{*} = 0.33\pm0.03\,R_{\odot}$ and albedo $\eta=0.32\pm0.05$, without the need of further components (thus excluding the visible presence of an extended accretion disc and/or of relativistic jets). The case was different for PSR J1023+0038, that was in its accretion phase during our campaign. We measured a LP of $1.09\pm0.27\%$ and $0.90\pm 0.17\%$ in the V and R bands, respectively. The phase-resolved polarimetric curve of the source in the R-band reveals a hint of a sinusoidal modulation at the source 4.75 hr orbital period, peaked at the same orbital phase as the light curve. The measured LP of PSR J1023+0038 could in principle be interpreted as scattering with free electrons (that can be found in the accretion disc of the system or even in the hot corona that surrounds the disc itself) or to synchrotron emission from a relativistic particles jet or outflow. However, the NIR-optical SED of the system built starting from our dataset did not suggest the presence of a jet. We conclude that the optical LP observed for PSR J1023+0038 is possibly due to Thomson scattering with electrons in the disc, as also suggested from the possible modulation of the R-band LP at the system orbital period.Comment: 10 pages, 8 figures, 4 tables. Accepted for publication in Sec. 7. Stellar structure and evolution of Astronomy and Astrophysic

The importance of warehouses in logistics outsourcing: benchmarking the perspectives of 3PL providers and shippers

Purpose: An ever-increasing number of companies outsource logistics activities to third-party logistics (3PL) providers to beat the competition. From the buyer's (shippers') perspective, selecting the right 3PL provider is crucial, and from the 3PL provider's perspective, it is imperative to be attractive and to retain clients. To this aim, a potential lever can be physical assets, such as warehouses, which the literature has traditionally neglected. The objective is to benchmark the importance of warehouses for 3PL providers to attract/retain clients and for shippers to select the right 3PL provider. Design/methodology/approach: The authors performed an empirical investigation through interviews on dyads (3PL providers/shippers) and utilized the Best-Worst Method (BWM) to rank the criteria used in the 3PL buying process and allow the warehouse's role to emerge. Findings: Results show that the 3PL buying process consists of four phases and three evaluation steps. The selection criteria are classified into three groups: order qualifiers, order winners and retention factors. The warehouse has different levels of importance throughout the process. It appears that it can indirectly enhance the attractiveness and retention capability of 3PL providers through other selection criteria. Originality/value: By combining the resource-based view and the customer value theory, this research extends the theory on logistics outsourcing by studying the phases of the 3PL buying process and scrutinizing the criteria used in different evaluation steps. The research adds a double perspective of analysis (3PL providers and shippers), which is missing in the literature, and focuses on the importance of warehouses

Two Dimensional Bistable Vibration Energy Harvester

n/

Whole-Head Functional Near-Infrared Spectroscopy as an Ecological Monitoring Tool for Assessing Cortical Activity in Parkinson’s Disease Patients at Different Stages

Functional near-infrared spectroscopy (fNIRS) is increasingly employed as an ecological neuroimaging technique in assessing age-related chronic neurological disorders, such as Parkinson’s disease (PD), mainly providing a cross-sectional characterization of clinical phenotypes in ecological settings. Current fNIRS studies in PD have investigated the effects of motor and non-motor impairment on cortical activity during gait and postural stability tasks, but no study has employed fNIRS as an ecological neuroimaging tool to assess PD at different stages. Therefore, in this work, we sought to investigate the cortical activity of PD patients during a motor grasping task and its relationship with both the staging of the pathology and its clinical variables. This study considered 39 PD patients (age 69.0 ± 7.64, 38 right-handed), subdivided into two groups at different stages by the Hoehn and Yahr (HY) scale: early PD (ePD; N = 13, HY = [1; 1.5]) and moderate PD (mPD; N = 26, HY = [2; 2.5; 3]). We employed a whole-head fNIRS system with 102 measurement channels to monitor brain activity. Group-level activation maps and region of interest (ROI) analysis were computed for ePD, mPD, and ePD vs. mPD contrasts. A ROI-based correlation analysis was also performed with respect to contrasted subject-level fNIRS data, focusing on age, a Cognitive Reserve Index questionnaire (CRIQ), disease duration, the Unified Parkinson’s Disease Rating Scale (UPDRS), and performances in the Stroop Color and Word (SCW) test. We observed group differences in age, disease duration, and the UPDRS, while no significant differences were found for CRIQ or SCW scores. Group-level activation maps revealed that the ePD group presented higher activation in motor and occipital areas than the mPD group, while the inverse trend was found in frontal areas. Significant correlations with CRIQ, disease duration, the UPDRS, and the SCW were mostly found in non-motor areas. The results are in line with current fNIRS and functional and anatomical MRI scientific literature suggesting that non-motor areas—primarily the prefrontal cortex area—provide a compensation mechanism for PD motor impairment. fNIRS may serve as a viable support for the longitudinal assessment of therapeutic and rehabilitation procedures, and define new prodromal, low-cost, and ecological biomarkers of disease progression

Movement cognition and narration of the emotions treatment versus standard speech therapy in the treatment of children with borderline intellectual functioning: A randomized controlled trial

Background: Borderline intellectual functioning (BIF) is defined as a "health meta-condition... characterized by various cognitive dysfunctions associated with an intellectual quotient (IQ) between 71 and 85 which determines a deficit in the individual's functioning both in the restriction of activities and in the limitation of social participation". It can be caused by many factors, including a disadvantaged background and prematurity. BIF affects 7-12% of primary school children that show academic difficulties due to poor executive functioning. In many children with BIF, language, movement and social abilities are also affected, making it difficult to take part in daily activities. Dropping out of school and psychological afflictions such as anxiety and depression are common in children with BIF. This study investigates whether an intensive rehabilitation program that involves all of the areas affected in children with BIF (Movement, Cognition and Narration of emotions, MCNT) is more effective than Standard Speech Therapy (SST). Methods: This is a multicenter interventional single blind randomized controlled study. Children aged between 6 to 11years who attend a mainstream primary school and have multiple learning difficulties, behavioral problems and an IQ ranging between 85 to 70 have been enrolled. Participants are randomly allocated to one of three groups. The first group receives individual treatment with SST for 45min, twice a week for 9months. The second group receives the experimental treatment MCNT for 3h per day, 5days/ week for 9months and children work in small groups. The third group consists of children on a waiting list for the SST for nine months. Discussion: BIF is a very frequent condition with no ad hoc treatment. Over the long term, there is a high risk to develop psychiatric disorders in adulthood. Due to its high social impact, we consider it very important to intervene during childhood so as to intercept the remarkable plasticity of the developing brain. Trial registration: "Study Let them grow: A new intensive and multimodal Treatment for children with borderline intellectual functioning based on Movement, Cognition and Narration of emotions", retrospectively registered in ISRCTN Register with ISRCTN81710297 at 2017-01-09

The puzzling case of the accreting millisecond X-ray pulsar IGR J00291+5934: flaring optical emission during quiescence

We present an optical (gri) study during quiescence of the accreting millisecond X-ray pulsar IGR J00291+5934 performed with the 10.4m Gran Telescopio Canarias (GTC) in August 2014. Despite the source being in quiescence at the time of our observations, it showed a strong optical flaring activity, more pronounced at higher frequencies (i.e. the g band). Once the flares were subtracted, we tentatively recovered a sinusoidal modulation at the system orbital period in all bands, even if a significant phase shift with respect to an irradiated star, typical of accreting millisecond X-ray pulsars is detected. We conclude that the observed flaring could be a manifestation of the presence of an accretion disc in the system. The observed light curve variability could be explained by the presence of a superhump, which might be another proof of the formation of an accretion disc. In particular, the disc at the time of our observations was probably preparing to the new outburst of the source, that happened just a few months later, in 2015.Comment: 6 pages, 2 figures, 1 table. Accepted for publication in A&

El reciclaje en Argentina y Chile

Uno de los grandes conflictos ambientales siempre ha radicado en crecimiento económico versus la explotación de los recursos naturales, a favor del progreso. A esto se suma el aumento de la población en localidades y ciudades, las cuales implican a su vez mayor emisión de residuos. Lo que debería de ser equivalente al aumento de conciencia ambiental y también significar una mayor posibilidad de protesta y acción por el medio ambiente, pero lamentablemente en la realidad no es así. El objetivo del trabajo es indagar en Valparaíso y Mendoza, justamente, sobre la inexistencia de un plan para la Gestión de los residuos sólidos urbanos –en adelante RSU-, es decir un régimen que incluya todas las etapas para el tratamiento de los RSU: generación, disposición inicial, recolección, transferencia, transporte, tratamiento y disposición final

Magnetically-Coupled Cantilevers with Antiphase Bistable Behavior for Kinetic Energy Harvesting

n/

Full NLO QCD predictions for Higgs-pair production in the 2-Higgs-doublet model

After the discovery of the Higgs boson in 2012 at the CERN Large Hadron Collider (LHC), the study of its properties still leaves room for an extended Higgs sector with more than one Higgs boson. 2-Higgs doublet models (2HDMs) are well-motivated extensions of the Standard Model (SM) with five physical Higgs bosons: two CP-even states h and H, one CP-odd state A, and two charged states $H^{\pm}$. In this letter, we present the calculation of the full next-to-leading order (NLO) QCD corrections to hH and AA production at the LHC in the 2HDM at small values of the ratio of the vacuum expectation values, $tan\space\beta$, including the exact top-mass dependence everywhere in the calculation. Using techniques applied in the NLO QCD SM Higgs pair production calculation, we present results for the total cross section as well as for the Higgs-pair-mass distribution at the LHC. We also provide the top-quark scale and scheme uncertainties which are found to be sizeable