Shocks to Product Networks and Post-Earnings Announcement Drift

This paper examines whether shocks to less visible product market peers are an important determinant of industry level post-earnings announcement drift (IPEAD) (Ayers and Freeman 1997; Hui et al. 2016). On the real-side, we find that a focal firm’s earnings are persistently related to the earnings surprises of its peers. On the financial-side, IPEAD arises only when these peers are less visible and when shocks are driven by persistent supply-side shocks to expenses, and not by demand-side shocks to sales. Text-based measures of disclosure opacity show that IPEAD is also stronger when firms provide less informative 10-K disclosures regarding their expenses. Collectively, our results suggest that inattention to less visible peers and a poor informational environment surrounding supply-side shocks are likely channels that generate IPEAD. IPEAD returns are economically large in subsamples motivated by this explanation

Armored Enzyme Nanoparticles for Remediation of Subsurface Contaminants

The remediation of subsurface contaminants is a critical problem for the Department of Energy, other government agencies, and our nation. Severe contamination of soil and groundwater exists at several DOE sites due to various methods of intentional and unintentional release. Given the difficulties involved in conventional removal or separation processes, it is vital to develop methods to transform contaminants and contaminated earth/water to reduce risks to human health and the environment. Transformation of the contaminants themselves may involve conversion to other immobile species that do not migrate into well water or surface waters, as is proposed for metals and radionuclides; or degradation to harmless molecules, as is desired for organic contaminants. Transformation of contaminated earth (as opposed to the contaminants themselves) may entail reductions in volume or release of bound contaminants for remediation. Research at Rensselaer focused on the development of haloalkane dehalogenase as a critical enzyme in the dehalogenation of contaminated materials (ultimately trichloroethylene and related pollutants). A combination of bioinformatic investigation and experimental work was performed. The bioinformatics was focused on identifying a range of dehalogenase enzymes that could be obtained from the known proteomes of major microorganisms. This work identified several candidate enzymes that could be obtained through relatively straightforward gene cloning and expression approaches. The experimental work focused on the isolation of haloalkane dehalogenase from a Xanthobacter species followed by incorporating the enzyme into silicates to form biocatalytic silicates. These are the precursors of SENs. At the conclusion of the study, dehalogenase was incorporated into SENs, although the loading was low. This work supported a single Ph.D. student (Ms. Philippa Reeder) for two years. The project ended prior to her being able to perform substantive bioinformatics efforts that would identify more promising dehalogenase enzymes. The SEN synthesis, however, was demonstrated to be partially successful with dehalogenases. Further work would provide optimized dehalogenases in SENs for use in pollution remission

Anti-Obesity and Anti-Adipogenic Effects of Chitosan Oligosaccharide (GO2KA1) in SD Rats and in 3T3-L1 Preadipocytes Models

Excess body weight is a major risk factor for type 2 diabetes (T2D) and associated metabolic complications, and weight loss has been shown to improve glycemic control and decrease morbidity and mortality in T2D patients. Weight-loss strategies using dietary interventions produce a significant decrease in diabetes-related metabolic disturbance. We have previously reported that the supplementation of low molecular chitosan oligosaccharide (GO2KA1) significantly inhibited blood glucose levels in both animals and humans. However, the effect of GO2KA1 on obesity still remains unclear. The aim of the study was to evaluate the anti-obesity effect of GO2KA1 on lipid accumulation and adipogenic gene expression using 3T3-L1 adipocytes in vitro and plasma lipid profiles using a Sprague-Dawley (SD) rat model. Murine 3T3-L1 preadipocytes were stimulated to differentiate under the adipogenic stimulation in the presence and absence of varying concentrations of GO2KA1. Adipocyte differentiation was confirmed by Oil Red O staining of lipids and the expression of adipogenic gene expression. Compared to control group, the cells treated with GO2KA1 significantly decreased in intracellular lipid accumulation with concomitant decreases in the expression of key transcription factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (CEBP/α). Consistently, the mRNA expression of downstream adipogenic target genes such as fatty acid binding protein 4 (FABP4), fatty acid synthase (FAS), were significantly lower in the GO2KA1-treated group than in the control group. In vivo, male SD rats were fed a high fat diet (HFD) for 6 weeks to induced obesity, followed by oral administration of GO2KA1 at 0.1 g/kg/body weight or vehicle control in HFD. We assessed body weight, food intake, plasma lipids, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) for liver function, and serum level of adiponectin, a marker for obesity-mediated metabolic syndrome. Compared to control group GO2KA1 significantly suppressed body weight gain (185.8 ± 8.8 g vs. 211.6 ± 20.1 g, p \u3c 0.05) with no significant difference in food intake. The serum total cholesterol, triglyceride, and low-density lipoprotein (LDL) levels were significantly lower in the GO2KA1-treated group than in the control group, whereas the high-density lipoprotein (HDL) level was higher in the GO2KA1 group. The GO2KA1-treated group also showed a significant reduction in ALT and AST levels compared to the control. Moreover, serum adiponectin levels were significantly 1.5-folder higher than the control group. These in vivo and in vitro findings suggest that dietary supplementation of GO2KA1 may prevent diet-induced weight gain and the anti-obesity effect is mediated in part by inhibiting adipogenesis and increasing adiponectin level

Comparison of pentacene and amorphous silicon AMOLED display driver circuits

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Effect of Surface and Bulk Properties of Mesoporous Carbons on the Electrochemical Behavior of GOx-Nanocomposites

Biofuel cell (BFC) electrodes are typically manufactured by combining enzymes that act as catalysts with conductive carbon nanomaterials in a form of enzyme-nanocomposite. However, a little attention has been paid to effects of the carbon nanomaterials' structural properties on the electrochemical performances of the enzyme-nanocomposites. This work aims at studying the effects of surface and bulk properties of carbon nanomaterials with different degrees of graphitization on the electrochemical performances of glucose oxidase (GOx)-nanocomposites produced by immobilizing GOx within a network of carbon nanopaticles. Two types of carbon nanomaterials were used: graphitized mesoporous carbon (GMC) and purified mesoporous carbon (PMC). Graphitization index, surface functional groups, hydrophobic properties, and rate of aggregation were measured for as-received and acid-treated GMC and PMC samples by using Raman spectrometry, X-ray photoelectron spectroscopy (XPS), contact angle measurement, and dynamic light scattering (DLS), respectively. In addition to these physical property characterizations, the enzyme loading and electrochemical performances of the GOx-nanocomposites were studied via elemental analysis and cyclic voltammetry tests, respectively. We also fabricated BFCs using our GOx-nanocomposite materials as the enzyme anodes, and tested their performances by obtaining current-voltage (IV) plots. Our findings suggest that the electrochemical performance of GOx-nanocomposite material is determined by the combined effects of graphitization index, electrical conductivity and surface chemistry of carbon nanomaterials

Comparing the neurologic outcomes of patients with out-of-hospital cardiac arrest according to prehospital advanced airway management method and transport time interval

Objective The incidences of prehospital advanced airway management by emergency medical technicians in South Korea are increasing; however, whether this procedure improves the survival outcomes of patients experiencing out-of-hospital cardiac arrest remains unclear. The present study aimed to investigate the association between prehospital advanced airway management and neurologic outcomes according to a transport time interval (TTI) using the Korean Cardiac Arrest Research Consortium database. Methods We retrospectively analyzed the favorable database entries that were prospectively collected between October 2015 and December 2016. Patients aged 18 years or older who experienced cardiac arrest that was presumed to be of a medical etiology and that occurred prior to the arrival of emergency medical service personnel were included. The exposure variable was the type of prehospital airway management provided by emergency medical technicians. The primary endpoint was a favorable neurologic outcome. Results Of 1,871 patients who experienced out-of-hospital cardiac arrest, 785 (42.0%), 121 (6.5%), and 965 (51.6%) were managed with bag-valve-mask ventilation, endotracheal intubation (ETI), and supraglottic airway (SGA) devices, respectively. SGAs and ETI provided no advantage in terms of favorable neurologic outcome in patients with TTIs ≥12 minutes (odds ratio [OR], 1.37; confidence interval [CI], 0.65–2.87 for SGAs; OR, 1.31; CI, 0.30–5.81 for ETI) or in patients with TTI <12 minutes (OR, 0.57; CI, 0.31–1.07 for SGAs; OR, 0.63; CI, 0.12–3.26 for ETI). Conclusion Neither the prehospital use of SGA nor administration of ETI was associated with superior neurologic outcomes compared with bag-valve-mask ventilation

Organic-inorganic hybrid thin film transistors and electronic circuits

Thin-film transistors (TFTs) capable of low-voltage and high-frequency operation will be required to reduce the power consumption of next generation electronic devices driven by microelectronic components such as inverters, ring oscillators, and backplane circuits for mobile displays. To produce high performance TFTs, transparent oxide-semiconductors are becoming an attractive alternative to hydrogenated amorphous silicon (a-Si:H)- and organic-based materials because of their high electron mobility vlaues and low processing temperatures, making them compatible with flexible substrates and opening the potential for low production costs. Practical electronic devices are expected to use p- and n-channel TFT-based complementary inverters to operate with low power consumption, high gain values, and high and balanced noise margins. The p- and n-channel TFTs should yield comparable output characteristics despite differences in the materials used to achieve such performance. However, most oxide semiconductors are n-type, and the only high performance, oxide-based TFTs demonstrated so far are all n-channel, which prevents the realization of complementary metal-oxide-semiconductor (CMOS) technologies. On the other hand, ambipolar TFTs are very attractive microelectronic devices because, unlike unipolar transistors, they operate independently of the polarity of the gate voltage. This intrinsic property of ambipolar TFTs has the potential to lead to new paradigms in the design of analog and digital circuits. To date, ambipolar TFTs and their circuits, such as inverters, have shown very limited performance when compared with that obtained in unipolar TFTs. For instance, the electron and hole mobilities typically found in ambipolar TFTs (ATFTs) are, typically, at least an order of magnitude smaller than those found in unipolar TFTs. Furthermore, for a variety of circuits, ATFTs should provide balanced currents during p- and n-channel operations. Regardless of the selection of materials, achieving these basic transistor properties is a very challenging task with the use of current device geometries. This dissertation presents research work performed on oxide TFTs, oxide TFT-based electronic circuits, organic-inorganic hybrid complementary inverters, organic-inorganic hybrid ambipolar TFTs, and ambipolar TFT-based complementary-like inverters in an attempt to overcome some of the current issues. The research performed first was to develop low-voltage and high-performance oxide TFTs, with an emphasis on n-channel oxide TFTs, using high-k and/or thin dielectrics as gate insulators. A high mobility electron transporting semiconductor, amorphous indium gallium zinc oxide (a-IGZO), was used as the n-channel active material. Such oxide TFTs were employed to demonstrate active matrix organic light emitting diode (AMOLED) display backplane circuits operating at low voltage. Then, high-performance hybrid complementary inverters were developed using unipolar TFTs employing organic and inorganic semiconductors as p- and n-channel layers, respectively. An inorganic a-IGZO and pentacene, a widely used organic semiconductor, were used as the n- and p-channel semiconductors, respectively. By the integration of the p-channel organic and n-channel inorganic TFTs, high-gain complementary inverters with high and balanced noise margins were developed. A new approach to find the switching threshold voltage and the optimum value of the supply voltage to operate a complementary inverter was also proposed. Furthermore, we proposed a co-planar channel geometry for the realization of high-performance ambipolar TFTs. Using non-overlapping horizontal channels of pentacene and a-IGZO, we demonstrate hybrid organic-inorganic ambipolar TFTs with channels that show electrical properties comparable to those found in unipolar TFTs with the same channel aspect ratios. A key characteristic of this co-planar channel ambipolar TFT geometry is that the onset of ambipolar operation is mediated by a new operating regime where one of the channels can reach saturation while the other channel remains off. This allows these ambipolar TFTs to reach high on-off current ratios approaching 104. With the new design flexibility we demonstrated organic-inorganic hybrid ambipolar TFT-based complementary-like inverters, on rigid and flexible substrates, that show a significant improvement over the performance found in previously reported complementary-like inverters. From a materials perspective, this work shows that future breakthroughs in the performance of unipolar n-channel and p-channel semiconductors could be directly transposed into ambipolar transistors and circuits. Hence, we expect that this geometry will provide new strategies for the realization of high-performance ambipolar TFTs and novel ambipolar microelectronic circuits.Ph.D.Committee Chair: Kippelen, Bernard; Committee Member: Anderson, David; Committee Member: Brand, Oliver; Committee Member: Graham, Samuel; Committee Member: Mukhopadhyay, Saiba

Metal-oxide complementary inverters with a vertical geometry fabricated on flexible substrates

© 2011 American Institute of Physics. The electronic version of this article is the complete one and can be found at: http://dx.doi.org/10.1063/1.3656974DOI: 10.1063/1.3656974We report on the fabrication of p-channel thin film transistors (TFTs) and vertically stacked complementary inverters comprised of a p-channel copper oxide TFT on top of an n-channel indium gallium zinc oxide TFT fabricated on a flexible polyethersulfone substrate. The p- and n-channel TFTs showed saturation mobility values of 0.0022 and 1.58 cm²/Vs, respectively, yielding inverters with a gain of 120 V/V. This level of performance was achieved by reducing the copper oxide channel thickness, allowing oxygen diffusion into the copper oxide layer at medium processing temperature (150 °C)