Simple ultraviolet-based soft-lithography process for fabrication of low-loss polymer polysiloxanes-based waveguides

A simple ultraviolet (UV)-based soft-lithography process is used for fabrication of polymer polysiloxanes (PSQ-L) waveguides. The imprint process is first done on the cladding PSQ-LL layer and is followed by a spin-coating step to fill the imprinted features with core PSQ-LH layer material. The optical loss of the straight PSQ-L waveguides is characterised by the Fabry-Perot method for the first time. Even with non-polished facet of the waveguide, the Fabry-Perot resonance spectrum is obtained. An upper limit scattering loss of the waveguide is extracted to be less than 0.8 +/- 0.2 dB/cm for TE mode and 1.3 +/- 0.2 dB/cm for TM mode at 1550 nm. The fully transferred pattern and low scattering loss proves it to be an effective way to replicate low-loss polymer PSQ-L-based waveguides

Buckling without bending: a new paradigm in morphogenesis

A curious feature of organ and organoid morphogenesis is that in certain cases, spatial oscillations in the thickness of the growing "film" are out-of-phase with the deformation of the slower-growing "substrate," while in other cases, the oscillations are in-phase. The former cannot be explained by elastic bilayer instability, and contradict the notion that there is a universal mechanism by which brains, intestines, teeth, and other organs develop surface wrinkles and folds. Inspired by the microstructure of the embryonic cerebellum, we develop a new model of 2d morphogenesis in which system-spanning elastic fibers endow the organ with a preferred radius, while a separate fiber network resides in the otherwise fluid-like film at the outer edge of the organ and resists thickness gradients thereof. The tendency of the film to uniformly thicken or thin is described via a "growth potential". Several features of cerebellum, +blebbistatin organoid, and retinal fovea morphogenesis, including out-of-phase behavior and a film thickness amplitude that is comparable to the radius amplitude, are readily explained by our simple analytical model, as may be an observed scale-invariance in the number of folds in the cerebellum. We also study a nonlinear variant of the model, propose further biological and bio-inspired applications, and address how our model is and is not unique to the developing nervous system.Comment: version accepted by Physical Review

Functional consequence of a novel Y129C mutation in a patient with two contradictory melanocortin-2-receptor mutations

L F C and T-T C are supported by M R C Clinical Research Training Fellowships (grant numbers G0600408, G0700581) and L A M by the Wellcome Trust (grant number 076430/Z/05/7)

Where do They Head for University Studies? The University Destinations of Chinese IBDP Graduates: A Study of the International Baccalaureate Diploma Program in China

Paper PresentationConference theme: Educational Reform and Social Change: East-West DialogueOver the last decade, the number of IB programs adopted by schools around the world has dramatically increased by almost 400% (IB, 2009; Lee et al., in-press). In recent years China has also evidenced an impressive gain in the number of schools adopting IB programs in general and the DP in particular. Specifically, as of 2011, there were 50 IB schools authorized for the implementation of the DP in China. Of these, 43 schools have been authorized since 2003 (IB, 2012), illustrating the fast growth of IBDP schools in China in recent years. Despite such fast growth (and by implication, popularity) of the IBDP schools in China, empirical studies exploring the impact of Chinese IBDP students’ learning outcomes in terms of their university matriculation to foreign universities seems to be almost nonexistent. With this in mind, the primary goal of this proposal is to document the patterns of university destination of IBDP graduates in China over time. To this end, our analysis centers on the following overarching question: Where have Chinese students who previously graduated from the 50 IB schools been educated? Alongside the focus of the main question, we seek answers to more specific questions: Are there any trends in their university destinations in terms of geographical region or university prestige (by ranking)? Are there any significant differences in students’ enrolment in foreign universities before or after the 50 IB schools’ adoption of the DP (in the case that the 50 IB schools implemented different international programs other than the DP before they adopted the IB)? Does the adoption of the DP contribute to the growth (rate) of DP graduates enrolled in foreign universities? To investigate these questions, we adopt a theoretical framework from research of international student mobility. Specifically, we focus on internal and external forces (Altbach, Reisberg & Rumbley, 2009; Li & Bray, 2007) that influence IB graduates’ international flow in terms of university destination. We employ a sequential explanatory design (Creswell, Plano, Gutmann, & Hanson, 2003). As part of the mixed-methods research project, we plan to collect longitudinal data on DP graduates’ destinations for university study since the adoption of the DP. A series of quantitative analysis (e.g., descriptive trend analysis, pre/post comparison “before and after” the 50 IB schools’ adoption of the DP, and longitudinal analysis using piecewise modeling) will be employed to determine trends and patterns in terms of university matriculation of the 50 schools over time. As first of its kind, this study will evidence the impact of the DP on student preparation for university studies abroad. In addition, the dataset may be employed for broader purposes (e.g., program development or evaluation) within the IB and the community of schools in China or East Asian countries.published_or_final_versio

Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (LDAS) and Other Assimilated Hydrological Data at NASA GES DISC

The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) provides science support for several data sets relevant to agriculture and food security, including the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (LDAS), or FLDAS data set. The GES DISC is one of twelve NASA Earth Observing System (EOS) data centers that process, archive, document, and distribute data from Earth science missions and related projects. The GES DISC hosts a wide range of remote sensing and model data, and provides reliable and robust data access and other services to users worldwide. Beyond data archive and access, the GES DISC offers many services to visualize and analyze the data. This presentation provides a summary of the hydrological data available at the GES DISC, along with an overview of related data services. Specifically, the FLDAS data set has been adapted to work with domains, data streams, and monitoring and forecast requirements associated with food security assessment in data-sparse, developing country settings. The FLDAS global monthly data have a 0.1 x 0.1 degree spatial resolution covering the period from January 1982 to present. Global FLDAS monthly anomaly and monthly climatology data are also available at the GES DISC to evaluate how current conditions compare to averages over the FLDAS 35-year period. Several case studies using the FLDAS soil moisture, evapotranspiration, rainfall, runoff, and surface temperature data will be presented

The location of an active nucleus and a shadow of a tidal tail in the ULIRG Mrk 273

Analysis of data from the Chandra X-ray Observatory for the double nucleus ULIRG Mrk 273 reveals an absorbed hard X-ray source coincident with the southwest nucleus, implying that this unresolved, near-infrared source is where an active nucleus resides, while the northern nuclear region contains a powerful starburst that dominates the far infrared luminosity. There is evidence of a slight image extension in the 6–7 keV band, where an Fe K line is present, towards the northern nucleus. A large-scale, diffuse emission nebula detected in soft X-rays contains a dark lane that spatially coincides with a high surface-brightness tidal tail extending ~50 arcsec (40 kpc) to the south. The soft X-ray source is likely located behind the tidal tail, which absorbs X-ray photons along the line of sight. The estimated column density of cold gas in the tidal tail responsible for shadowing the soft X-rays is N_H ≥ 6 × 10^(21) cm^(-2), consistent with the tidal tail having an edge-on orientation

Substrate-regulated morphology of graphene

We delineate a general theoretical framework to determine the substrate-regulated graphene morphology through energy minimization. We then apply such a framework to study the graphene morphology on a substrate with periodic surface grooves. Depending on the substrate surface roughness and the graphene-substrate interfacial bonding energy, the equilibrium morphology of graphene ranges from 1) closely conforming to the substrate, to 2) remaining flat on the substrate. Interestingly, in certain cases, the graphene morphology snaps between the above two limiting states. Our quantitative results envision a promising strategy to precisely control the graphene morphology over large areas. The rich features of the substrate-regulated graphene morphology (e.g., the snap-through instability) can potentially lead to new design concepts of functional graphene device components.Comment: 23 pages, 5 figure

Acquired resistance to anti-PD1 therapy: checkmate to checkpoint blockade?

Editorial summary Anti-programmed cell death 1 (PD1) immunotherapies are among the most effective anti-cancer immunotherapies available; however, a large number of patients present with or develop resistance to them. Unfortunately, very little is known regarding the mechanisms of resistance to such therapies. A recent study sought to identify mutations associated with resistance to anti-PD1 therapy. Results from this study demonstrated that mutations which affected the sensitivity of tumor cells to T-cell-derived interferons, and mutations limiting tumor-cell antigen presentation, could cause acquired resistance. These findings have significant implications for understanding the mechanisms by which anti-PD1 therapies exert their efficacy, comprehending why and how some patients acquire resistance over time, and ultimately guiding the development of combination therapies designed to overcome, or potentially prevent, the development of acquired immunotherapeutic resistance

Long Term Potential Evapotranspiration and Evapotranspiration Data and Services at NASA GES DISC

Recently, the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) has released global land 3-hourly Potential Evapotranspiration and Supporting Forcing Data Version-1 (PET_PU_3H025.001), at 0.25x0.25 degree spatial resolution, spanning the 23 year period from 1984 to 2006. The Version-2 will be released in the near future, covering longer time period. This dataset was generated by Professor Justin Sheffield through NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) project. Potential evapotranspiration (PET) is a representation of the environmental demand for evapotranspiration (ET). ET and PET are important part of the global water cycle estimation, and are also critical to advance our understanding of the climate system. NASA GES DISC archives and distributes various global and regional ET datasets from several projects, for example, Land Data Assimilation System (LDAS), Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), other MEaSUREs Projects, such as Land Surface Atmospheric Boundary Interaction Product by William Rossow; and SRB/GEWEX evapotranspiration (Penman-Monteith) by Eric F. Wood. In this presentation, we will overview all available PET and ET datasets and services at GES DISC. As examples, climatology and some seasonal characteristics of PET and selected ET will be shown. The data can be accessed from NASA GES DISC (https://disc.gsfc.nasa.gov/) by searching keyword "evapotranspiration"