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This paper aims to provide evidence on whether the specialization of schools in certain teaching strategies contributes to promoting student skills. Specifically, we will focus on comparing those that make intensive use of innovative practices with those specialized in the use of traditional methodologies. By employing propensity score matching (PSM) to reduce potential bias related to the different characteristics of schools, we provide robust evidence that specialization in the use of innovative teaching practices does not lead to better academic performance and may even be harmful to some competencies.

There is extensive literature focused on the evaluation of efficiency in the education sector, both at the micro level, analyzing the performance of students or schools, and at the macro level, exploring the behavior of regions or countries. This type of studieshas been driven by exploiting data available in international large-scale assessments, where output measures are usually represented by the so-called plausible values, understood as a representation of the range of the abilities of each student. In this study, we analyze the different options available to incorporate these plausible values in applied studies focused on measuring efficiency and how the results obtained can be affected according to the selected criterion. To do this, we assess the efficiency of Spanish schools participating in PISA using the two most common methodologies in this field: data envelopment analysis and stochastic frontier analysis and considering three different proxies for the educational output: (i) a single plausible value; (ii) an aggregate measure calculated from the ten plausible values available; (iii) an average of the estimates made with the ten plausible values separately. The main conclusion derived from our results is that there are hardly any differences between in the estimates made with different strategies. [ABSTRACT FROM AUTHOR]

Abstract: We present a novel ligand, 5‐norbornene‐2‐nonanoic acid, which can be directly added during established quantum dot (QD) syntheses in organic solvents to generate “clickable” QDs at a few hundred nmol scale. This ligand has a carboxyl group at one terminus to bind to the surface of QDs and a norbornene group at the opposite end that enables straightforward phase transfer of QDs into aqueous solutions via efficient norbornene/tetrazine click chemistry. Our ligand system removes the traditional ligand‐exchange step and can produce water‐soluble QDs with a high quantum yield and a small hydrodynamic diameter of approximately 12 nm at an order of magnitude higher scale than previous methods. We demonstrate the effectiveness of our approach by incubating azido‐functionalized CdSe/CdS QDs with 4T1 cancer cells that are metabolically labeled with a dibenzocyclooctyne‐bearing unnatural sugar. The QDs exhibit high targeting efficiency and minimal nonspecific binding. [ABSTRACT FROM AUTHOR]

This article examines the productivity of hotels operating in the two main sun and sand tourism markets in Spain, the Balearic, and the Canary Islands, from 2004 to 2013. In this manner, we can evaluate the impact of the global economic crisis on this sector. To tackle this issue, we apply alternative Malmquist productivity index decompositions to distinguish between different components of productivity. The results reveal that the economic downturn had major negative effects on hotel productivity for 2 years (2008 and 2009). After that period, hotels have increased their productivity levels driven by both technological and catching-up changes. This result provides new evidence supporting the fact that units operating in those destinations might avoid the process of decline predicted by Butler's life cycle model. [ABSTRACT FROM AUTHOR]

This article examines the impact of the reforms introduced in the structure of the Portuguese local administration after the bailout agreement in 2011 on the efficiency and productivity of municipalities. In order to determine a measure of productivity change, we apply the global Malmquist productivity index to assess the performance of the 278 Portuguese mainland municipalities for the recent 6-year period 2009–2014. The overall results reveal that there was a decrease in the global productivity until 2013 followed by a notable increase in 2014 basically due to technological changes, thus it seems that the reforms have had a positive effect on the productivity of municipalities. [ABSTRACT FROM PUBLISHER]

Medical imaging is routine in the diagnosis and staging of a wide range of medical conditions. In particular, magnetic resonance imaging (MRI) is critical for visualizing soft tissue and organs, with over 60 million MRI procedures performed each year worldwide. About one-third of these procedures are contrast-enhanced MRI, and gadolinium-based contrast agents (GBCAs) are the mainstream MRI contrast agents used in the clinic. GBCAs have shown efficacy and are safe to use with most patients; however, some GBCAs have a small risk of adverse effects, including nephrogenic systemic fibrosis (NSF), the untreatable condition recently linked to gadolinium (Gd) exposure during MRI with contrast. In addition, Gd deposition in the human brain has been reported following contrast, and this is now under investigation by the US Food and Drug Administration (FDA). To address a perceived need for a Gd-free contrast agent with pharmacokinetic and imaging properties comparable to GBCAs, we have designed and developed zwitterion-coated exceedingly small superparamagnetic iron oxide nanoparticles (ZES-SPIONs) consisting of ∼3-nm inorganic cores and ∼1-nm ultrathin hydrophilic shell. These ZES-SPIONs are free of Gd and show a high T1 contrast power. We demonstrate the potential of ZES-SPIONs in preclinical MRI and magnetic resonance angiography. [ABSTRACT FROM AUTHOR]

Acute toxic leukoencephalopathy can be caused by exposure to many compounds. Reversibility has been described in some cases with prompt recognition and withdrawal of the offending agent. Its association with a thermogenic supplement has never been reported. We describe two such cases in young women taking a commercially available thermogenic dietary supplement who presented with acute neurologic deficits and a common magnetic resonance imaging pattern. [ABSTRACT FROM AUTHOR]

International large-scale assessments (ILSAs) provide several measures as a representation of educational outcomes, the so-called plausible values, which are frequently interpreted as a representation of the ability range of students. In this paper, we focus on how this information should be incorporated into the estimation of efficiency measures of student or school performance using data envelopment analysis (DEA). Thus far, previous studies that have adopted this approach using data from ILSAs have used only one of the available plausible values or an average of all of them. We propose an approach based on the fuzzy DEA, which allows us to consider the whole distribution of results as a proxy of student abilities. To assess the extent to which our proposal offers similar results to those obtained in previous studies, we provide an empirical example using PISA data from 2015. Our results suggest that the performance measures estimated using the fuzzy DEA approach are strongly correlated with measures calculated using just one plausible value or an average measure. Therefore, we conclude that the studies that decide upon using one of these options do not seem to be making a significant error in their estimates. [ABSTRACT FROM AUTHOR]

Magneto-fluorescent particles have been recognized as an emerging class of materials that exhibit great potential in advanced applications. However, synthesizing such magneto-fluorescent nanomaterials that simultaneously exhibit uniform and tunable sizes, high magnetic content loading, maximized fluorophore coverage at the surface, and a versatile surface functionality has proven challenging. Here we report a simple approach for co-assembling magnetic nanoparticles with fluorescent quantum dots to form colloidal magneto-fluorescent supernanoparticles. Importantly, these supernanoparticles exhibit a superstructure consisting of a close packed magnetic nanoparticle “core” which is fully surrounded by a “shell” of fluorescent quantum dots. A thin layer of silica-coating provides high colloidal stability and biocompatiblity and a versatile surface functionality. We demonstrate that after surface pegylation, these silica-coated magneto-fluorescent supernanoparticles can be magnetically manipulated inside living cells while being optically tracked. Moreover, our silica-coated magneto-fluorescent supernanoparticles can also serve as an in vivo multi-photon and magnetic resonance dual-modal imaging probe.

The use of visible/NIR-emitting gold nanoclusters (Au NCs), previously proposed for in vivo imaging, has been limited to some extent by low quantum yields (QYs) and the limited penetration of visible light in tissue. Here we report short wavelength infrared (SWIR, λ = 1-2 μm) emitting Au NCs with a good photoluminescence QY for this wavelength range (0.6% to 3.8% for λ em = 1000 to 900 nm) and excellent stability under physiological conditions. We show that surface ligand chemistry is critical to achieving these properties. We demonstrate the potential of these SWIR-emitting Au NCs for in vivo imaging in mice. The Au NCs have a hydrodynamic diameter that is small (∼5 nm) enough that they exhibit a rapid renal clearance, and images taken in the SWIR region show better resolution of the blood vessels than in the NIR region.

The potential of superparamagnetic iron oxide nanoparticles (SPIONs) in various biomedical applications, including magnetic resonance imaging (MRI), sensing, and drug delivery, requires that their surface be derivatized to be hydrophilic and biocompatible. We report here the design and synthesis of a compact and water-soluble zwitterionic dopamine sulfonate (ZDS) ligand with strong binding affinity to SPIONs. After ligand exchange, the ZDS-coated SPIONs exhibit small hydrodynamic diameters, and stability with respect to time, pH, and salinity. Furthermore, small ZDS coated SPIONs were found to have a reduced nonspecific affinity (compared to negatively charged SPIONs) toward serum proteins; streptavidin/dye functionalized SPIONs were bioactive and thus specifically targeted biotin receptors., (© 2011 American Chemical Society)