The comparison of stochastic frontier analysis with panel data models

From the idea of efficiency raised by Koopmans in 1951, and the panel data first introduced into the efficiency analysis by Pitt and Lee (1981) and Schmidt and Sickles (1984), the techniques of stochastic frontier analysis are fast developed and the applications of stochastic frontier are widely used in different areas, such as education, industry and hospital. But most researchers focus on only one aspect, either the development of new models or empirical applications. This thesis attempts to fill the gap to get a general idea of the properties of different panel data stochastic frontier models, on both statistical aspects and economic aspects, by the comparison of different models applied to different production applications. The thesis is also attempt to shed light on whether particular panel data stochastic frontier models are better suited to different data sets. The models selected capture the simplest situation, with no heterogeneity or heteroscedasticity, and complicated ones, with exogenous variables included in the models. Not only the classical models, such as the Pitt and Lee (1981) and Battese and Coelli (1992.1995), but also the new developed models, such as the latent class model and fixed management model are detected in the thesis. On the economic aspect, the data selected captures both microeconomic and macroeconomic, with the application to the World GDP and the Italian manufacturing industry. The results show that: the panel data stochastic frontier models perform better on the microeconomic level than on the macroeconomic level; the classical models perform better than the new developed ones; some panel data stochastic frontier models make ideal assumptions but the requirements to the dataset are hard to achieve; that the influence from the exogenous variables is quite strong

第730回 千葉医学会例会・第1回 磯野外科例会 21.

Figure S6. Fluorescence micrograph of a 0.5 mm diameter disc cut from MCW1 using a micro-punch sampler. The micrograph shows the disc containing ~ 610 tracheids, with autofluorescent walls. The disc was from Tree 1 and the micrographs obtained using a DMR microscope. Scale bar: 100 μm. (PDF 80 kb

Graphene-Based Membranes for Molecular Separation

In comparison with traditional chemical separation processes, membrane separation is much simpler and more efficient. An ideal membrane for molecular separation should be as thin as possible to maximize its solvent flux, be mechanically robust to prevent it from fracture, and have well-defined pore sizes to guarantee its selectivity. Graphene is an excellent platform for developing size-selective membranes because of its atomic thickness, high mechanical strength, and chemical inertness. In this Perspective, we review the recent advancements on the fabrication of nanoporous graphene membranes and graphene oxide membranes (GOMs) for molecular separation. The methods of fabricating these membranes are summarized, and the mechanisms of molecular separation based on these two types of graphene membranes are compared. The challenges of synthesizing and transferring large-area nanoporous graphene membranes and engineering the performances of GOMs are discussed

Data_Sheet_1_Brain optimization with additional study time: potential brain differences between high- and low-performance college students.ZIP

This study investigates potential differences in brain function among high-, average-, and low-performance college students using electroencephalography (EEG). We hypothesize that the increased academic engagement of high-performance students will lead to discernible EEG variations due to the brain’s structural plasticity. 61 third-year college students from identical majors were divided into high-performance (n = 20), average-performance (n = 21), and low-performance (n = 20) groups based on their academic achievements. We conducted three EEG experiments: resting state, Sternberg working memory task, and Raven progressive matrix task. Comprehensive analyses of the EEG data from the three experiments focused on power spectral density (PSD) and functional connectivity, with coherence (COH) employed as our primary metric for the latter. The results showed that in all experiments, there were no differences in working memory ability and IQ scores among the groups, and there were no significant differences in the power spectral densities of the delta, theta, alpha1, alpha2, beta, and gamma bands among the groups. Notably, on the Raven test, compared to their high-performing peers, low-performing students showed enhanced functional connectivity in the alpha 1 (8–9 Hz) band that connects the frontal and occipital lobes. We explored three potential explanations for this phenomenon: fatigue, anxiety, and greater cognitive effort required for problem-solving due to inefficient self-regulation and increased susceptibility to distraction. In essence, these insights not only deepen our understanding of the neural basis that anchors academic ability, but also hold promise in guiding interventions that address students’ diverse academic needs.</p

Media comparison and model of FTDA mechanism.

<p>(<b>A</b>) hESC line NCL3 and (<b>B</b>) iPS line 1 were cultured for 3 passages in FTDA, in MEF-CM, and in proprietary media. All media sustained pluripotency, but differentiation tended to be increased in MEF-CM and some proprietary media, compared to FTDA. Top: Stereo microscopic view. Bottom: Gene expression analysis relative to FTDA (n = 3). (<b>C</b>) Model of our understanding of the pluripotency-sustaining mechanism of FTDA. FGF2, TGFβ1 and Activin A cooperatively support self-renewal, whereas DM inhibits spontaneous extraembryonic differentiation. IWP-2 may additionally be used if cells tend to spontaneously differentiate into mesendoderm.</p

Small Molecule-Assisted, Line-Independent Maintenance of Human Pluripotent Stem Cells in Defined Conditions

<div><p>Human pluripotent stem cells (hPSCs) are conventionally grown in a mouse feeder cell-dependent manner. Chemically defined culture conditions are, however, desirable not only for potential medically oriented applications but also for investigating mechanisms of self-renewal and differentiation. In light of the rather high complexity and cost of existing defined hPSC culture systems, we have systematically evaluated over 20 potential media ingredients. Only components that reproducibly gave beneficial effects were ultimately combined to yield a simple and cost-effective formulation termed FTDA. This xeno-free medium is based on mimicking self-renewal factor activities present in mouse embryonic fibroblast-conditioned medium, at minimal dosages. Additionally, small molecule inhibitors of BMP and WNT signaling served to specifically suppress typical types of spontaneous differentiation seen in hPSC cultures. FTDA medium was suitable for the generation of human induced pluripotent stem cells and enabled robust long-term maintenance of diverse hPSC lines including hard-to-grow ones. Comparisons with existing defined media suggested reduced spontaneous differentiation rates in FTDA. Our results imply that using supportive factors at minimal concentrations may still promote robust self-renewal and preserve pluripotency of hPSCs.</p> </div

Validation of optimized FTDA medium.

<p>(<b>A</b>) hESCs grown in FTDA medium for more than 20 passages exhibited robust expression of self-renewal markers (top row), stable karyotype, and rapid growth rates (bottom left). Bottom right: FTDA allowed clonal expansion from single cells replated in the presence of Y27632 as well as effective formation of embryoid bodies. (<b>B</b>) hES cells grown in FTDA for multiple passages could be induced to form early neuroectodermal, mesodermal, or endodermal precursors, using the same basal medium but different growth factors (top row). Using directed or spontaneous differentiation protocols, cells gave rise to terminally differentiated cell types of all three germ layers (middle row). Bottom: H&E stained teratoma sections formed by HuES6 cells grown for more than 20 passages in the defined medium.</p

8925174 Raw data Biomed Research Inte.rar

miR-504 antagomir up-regulates NIS expression and improves the effect of 131 I therapy in thyroid cance

Dorsomorphin prevents spontaneous TE-like differentiation in chemically defined hESC medium.

<p>(<b>A</b>) Colonies in N2B27+ FGF2 fail to expand well after several passages (line HuES6). (<b>B</b>) Typical spontaneous differentiation formed in centers of colonies. Representative differentiated and undifferentiated parts were collected for further analysis (right panels). (<b>C</b>) Real-time RT-PCR analysis of samples in (B). (<b>D</b>) Immunocytochemistry confirms that inner differentiated cells stain positive for HAND1. (<b>E</b>) Dorsomorphin addition to N2B27 completely prevents TE-like differentiation in routine culture (line H7). (<b>F</b>) Titration of optimal dorsomorphin dosage. At 50 nM, both TE-like and neural differentiation rates were minimal.</p

Direct reprogramming in FTDA.

<p>(<b>A</b>) FTDA allowed derivation of hiPS colonies after viral transduction of adult dermal fibroblasts with OCT4, SOX2, KLF4 and c-MYC. (<b>B</b>) The number of hiPS colonies increased over time, reaching an average of 24 per 12,500 seeded cells (0.2%). (<b>C</b>) Emerging hiPS colonies could be picked and expanded in FTDA and homogenously stained positive for pluripotency markers <i>OCT4</i> and <i>NANOG</i>. (<b>D</b>) Spontaneous in-vitro differentiation of hiPSCs derived under FTDA conditions yielded cell types representative of all 3 germ layers.</p