Scholarly efforts to identify core design features for effective professional development (PD) efforts have rapidly grown in the last two decades. Based on extensive literature reviews, meta analyses and large-scale quantitative studies, scholars have arrived at short lists of core design principles for effective PD programs. These design principles are presented as based on strong evidence from large-scale, replicated and rigorous research studies, and as at the heart of consensus among PD scholars. In the present essay, we appraise the quality of the evidence on which this claim is based. We identify several major flaws in the research base on which such claims are based and conclude that, overall, the evidence is weak and claims about strong evidence-based findings are misleading. Additional reservations about this research program are discussed.
Graphene and its derivatives have been reported as materials with excellent electrical and thermal conductivity, allowing for various promising applications. In particular, the large-scale surface coating of graphene-based materials can be employed to minimize cross-sectional heat transfer through the glass window. This study introduces a facile and cost-effective method to fabricate graphene quantum dots (GQDs) thin film on Fluorine-doped Tin Oxide (FTO) glass via casting of the GQDs dispersion and stabilizing with poly-vinyl-pyrrolidone (PVP). The thin film possesses excellent optical properties of GQDs and allows more than 80% of visible transmittance. The presence of the GQDs thin film shows effective reduction in the cross-sectional thermal diffusivity of FTO glass, from 0.55 mm2/s to zero when measured with laser flash over a 4-second period. This low cost and eco-friendly GQDs thin film will be a promising material for heat management in smart window applications.
Second skin is a topically applied, skin-conforming material that mimics human skin properties and bears potential cosmetic and e-skin applications. To successfully integrate with natural skin, characteristics such as color and skin features must be matched. In this work, we prepared bio-based skin-like films from cross-linked keratin/melanin films (KMFs), using a simple fabrication method and non-toxic materials. The films retained their stability in aqueous solutions, showed skin-like mechanical properties, and were homogenous and handleable, with non-granular surfaces and a notable cross-linked structure as determined by attenuated total reflection (ATR). In addition, the combination of keratin and melanin allowed for adjustable tones similar to those of natural human skin. Furthermore, KMFs showed light transmittance and UV-blocking (up to 99%) as a function of melanin content. Finally, keratin/melanin ink (KMI) was used to inkjet-print high-resolution images with natural skin pigmented features. The KMFs and KMI may offer advanced solutions as e-skin or cosmetics platforms.
A near-perfect black solar absorber made of carbon nanotubes (CNTs) prepared by a low-cost wet-deposition method on a reflective metal surface for mid-temperature non-evacuated concentrated solar power (CSP) applications is demonstrated. The dispersed CNTs in an alumina–silica matrix exhibit an absorptance of 0.985 in the entire solar spectrum and emittance of 0.90 in the infrared (IR) region. The coating shows high durability and is super-hydrophilic (0° contact angle) after plasma treatment, without affecting the solar absorptance and excellent coating adhesion. The efficiency of the coating is evaluated by analytical models, which implies that it has higher efficiency at low temperature and at a high solar concentration ratio than that of previously reported selective coatings.
The 3D printing process enables to print objects having various functionalities at pre-designed locations in the object. Hereby, we report on the printing of superhydrophobic objects composed of patterns of micropillars. Superhydrophobicity is an important property of surfaces that has applications in various fields such as self-cleaning, drag reduction, increased buoyancy, and air conditioning. Most existing methods for the fabrication of superhydrophobic surfaces are complicated and time-consuming. Here, we performed a simple and cost-effective process for the fabrication of superhydrophobic (SH) objects by Digital Light Processing (DLP) 3D printing. To the best of our knowledge, this is the first study that has used DLP 3D printing to fabricate SH 3D objects without further coating process. We designed a novel ink, which contained non-fluorinated acrylates and Hydrophobic Fumed Silica (HFS). We studied the effects of HFS concentration and pillar-array design for imparting the SH property, which was measured in terms of the contact and rolling angle of water droplets on the surface. As proof of the concept of increased buoyancy by superhydrophobicity, we demonstrated the floatation of the printed SH objects in comparison to their non-SH counterparts even after forcefully submerging them into water.
Petr Skopintsev, David Ehrenberg, Tobias Weinert, Daniel James, Rajiv K. Kar, Philip J. M. Johnson, Dmitry Ozerov, Antonia Furrer, Isabelle Martiel, Florian Dworkowski, Karol Nass, Gregor Knopp, Claudio Cirelli, Christopher Arrell, Dardan Gashi, Sandra Mous, Maximilian Wranik, Thomas Gruhl, Demet Kekilli, Steffen Brünle, Xavier Deupi, Gebhard F. X. Schertler, Roger M. Benoit, Valerie Panneels, Przemyslaw Nogly, Igor Schapiro, Christopher Milne, Joachim Heberle, and Jörg Standfuss. 2020. “Femtosecond-to-millisecond structural changes in a light-driven sodium pump”. Publisher's VersionAbstract
Light-driven sodium pumps actively transport small cations across cellular membranes1. These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved2,3, it is unclear how structural alterations over time allow sodium to be translocated against a concentration gradient. Here, using the Swiss X-ray Free Electron Laser4, we have collected serial crystallographic data at ten pump–probe delays from femtoseconds to milliseconds. High-resolution structural snapshots throughout the KR2 photocycle show how retinal isomerization is completed on the femtosecond timescale and changes the local structure of the binding pocket in the early nanoseconds. Subsequent rearrangements and deprotonation of the retinal Schiff base open an electrostatic gate in microseconds. Structural and spectroscopic data, in combination with quantum chemical calculations, indicate that a sodium ion binds transiently close to the retinal within one millisecond. In the last structural intermediate, at 20 milliseconds after activation, we identified a potential second sodium-binding site close to the extracellular exit. These results provide direct molecular insight into the dynamics of active cation transport across biological membranes.
Many researchers consider the presentation of diverse content as a prerequisite for the news media to fully exercise their democratic mandate. While prior news diversity studies have contributed important theoretical insights, we argue here that scholarly knowledge of this concept can be significantly advanced by employing computational methods for text analysis. Using automated methods, researchers can increase both the scope of data being analyzed and the resolution of the analysis. This article presents a novel framework for analyzing news diversity consisting of two distinct stages. In the first stage, a computational text classification method is used to analyze, at a high resolution, the attention given in news texts to a broad range of political and social issues. In the second stage, the text classifications are aggregated, and the distributions of media attention to those issues (i.e., news diversity) are assessed on a large scale. After presenting the novel approach, we illustrate its usefulness for testing theoretical hypotheses about news diversity. We compare the diversity of economic coverage in three elite and three popular US newspapers (N = 252,807 articles) and find that a fine-grained analysis relaxes concerns raised in previous studies about low content diversity in the popular press.
At site flood frequency analysis (FFA) in arid/semi-arid watersheds poses unique challenges to researchers and practitioners due to the generally limited data records. This study presents a comprehensive evaluation of FFA in arid/semi-arid watersheds in relation to the unique characteristics of these regions, such as the limited number of floods occurring each year and the large variability of the flood peak discharges. Study cases in Israel and the US are examined and compared with non-arid watersheds, characterized by Mediterranean climate, and with synthetic flood records. Results show that the tail of extreme value distributions describing arid/semi-arid watersheds is found to be heavier than the one describing Mediterranean watersheds. The number of yearly floods and the variability of flood peak discharge are shown to have a crucial impact on the accuracy of the quantile estimates with smaller number of events per year and larger coefficient of variation of flood peak discharge being related to larger errors in the estimated quantiles. Partial duration series approach provides a slightly reduced bias in the estimates, but should not be blindly preferred over annual maxima series as it presents comparable estimation uncertainty. In general, the generalized extreme value and the generalized Pareto distribution are found to be non-optimal choices for the examined arid/semi-arid watersheds.
Author summary Birt-Hogg-Dubé (BHD) syndrome is a dominantly inherited genetic disease characterized by predisposition to fibrofolliculomas, lung cysts, and renal cancer. The disease is linked to germline variants in the folliculin (FLCN) tumor suppressor gene. Here, we present a combined computational and experimental study, focusing on rare BHD-linked missense and single amino acid deletion variants. Our data show that many disease-causing FLCN variants lead to structural destabilization and rapid proteasomal degradation of the FLCN protein. The reduced level of FLCN, in turn, leads to degradation of the FLCN binding partners FNIP1 and FNIP2. Additional results show that the turnover of FLCN is regulated by the deubiquitylating enzyme Ubp15/USP7 and molecular chaperones. We propose that for some missense variants, stabilization and resulting restoration of function may hold therapeutic potential, and that our computational saturation scan encompassing both missense variants and single site deletions in FLCN may allow classification of rare FLCN variants of uncertain clinical significance.
This paper proposes a formal definition of reanalysis, while emphasizing the importance of the distinction between two different kinds of reanalysis: those in which the change is confined to the grammatical level, and those in which it is confined to the semantic level. After tracing the history of a negative counterfactual conditional marker in Hebrew and Aramaic which underwent both syntactic and semantic reanalyses, the paper assesses the concept of reanalysis with focus on the following questions: Is reanalysis a single, clearly-defined phenomenon, and if so, what is its nature? Is it merely a descriptive label for a certain observable state of affairs, or does it explain diachronic changes? Alternatively, perhaps it is a theoretical constraint, a theoretical requirement that linguistic change must be associated with specific environments where reanalysis can take place? A detailed analysis of the marker and its evolution yields the following broad hypothesis: Reanalysis of a linguistic form does not change the truth conditions of the proposition that contains it, regardless of whether the reanalysis is on the grammatical level or on the semantic level.
The invention discloses particular water-dispersible solid formulation of a cannabinoid or a cannabis extract , wherein they are present in the form of a nanoemulsion , and upon dispersion in water said formulation produces nanoparticles (droplets of a submicron size) with an average size of up to about 500 nm. The present disclosure further relates to methods of making thereof , as well as therapeutic applica tions in humans for treating disorders and broader applica tion for a range of medical conditions .
