Technology in purchasing: Impacts on performance and future confidence

This study investigates how top Finance & Accounting managers perceive the performance implications of adopting technologies to improve Purchasing processes. Based on a large-sample (454) survey, we employ multivariate data analysis techniques to specifically provide insights into how e-Purchasing impacts organizational performance. We model a theoretical construct of e-Purchasing and empirically confirm our literature-based hypotheses that e-Purchasing strongly and positively correlates with the integration between the Finance and Purchasing departments, improves the operational performance within these departments, and positively affects the confidence of managers in future organizational performance in the face of internal and external risk. We discuss implications for purchasing and supply researchers and practitioners as well as areas for further research.e-Purchasing; Internal Integration; Empirical Research Methods;

Wireless actuation of micromechanical resonators

The wireless transfer of power is of fundamental and technical interest, with applications ranging from the remote operation of consumer electronics and implanted biomedical devices and sensors to the actuation of devices for which hard-wired power sources are neither desirable nor practical. In particular, biomedical devices that are implanted in the body or brain require small-footprint power receiving elements for wireless charging, which can be accomplished by micromechanical resonators. Moreover, for fundamental experiments, the ultralow-power wireless operation of micromechanical resonators in the microwave range can enable the performance of low-temperature studies of mechanical systems in the quantum regime, where the heat carried by the electrical wires in standard actuation techniques is detrimental to maintaining the resonator in a quantum state. Here we demonstrate the successful actuation of micron-sized silicon-based piezoelectric resonators with resonance frequencies ranging from 36 to 120 MHz at power levels of nanowatts and distances of ~3 feet, including comprehensive polarization, distance and power dependence measurements. Our unprecedented demonstration of the wireless actuation of micromechanical resonators via electric-field coupling down to nanowatt levels may enable a multitude of applications that require the wireless control of sensors and actuators based on micromechanical resonators, which was inaccessible until now.http://nano.bu.edu/Papers_files/micronano201636.pdfPublished versio

Sensing of the melanoma biomarker TROY using silicon nanowire field-effect transistors

Antibody-functionalized silicon nanowire field-effect transistors have been shown to exhibit excellent analyte detection sensitivity enabling sensing of analyte concentrations at levels not readily accessible by other methods. One example where accurate measurement of small concentrations is necessary is detection of serum biomarkers, such as the recently discovered tumor necrosis factor receptor superfamily member TROY (TNFRSF19), which may serve as a biomarker for melanoma. TROY is normally only present in brain but it is aberrantly expressed in primary and metastatic melanoma cells and shed into the surrounding environment. In this study, we show the detection of different concentrations of TROY in buffer solution using top-down fabricated silicon nanowires. We demonstrate the selectivity of our sensors by comparing the signal with that obtained from bovine serum albumin in buffer solution. Both the signal size and the reaction kinetics serve to distinguish the two signals. Using a fast-mixing two-compartment reaction model we are able to extract the association and dissociation rate constants for the reaction of TROY with the antibody immobilized on the sensor surface.The authors thank Biosite Diagnostics (San Diego, CA) for providing TROY antibodies. The authors acknowledge NIH, NSF, and Battelle Memorial Institute for support of this work. (NIH; NSF; Battelle Memorial Institute)https://pubs.acs.org/doi/pdf/10.1021/acssensors.6b00017Accepted manuscrip

mTORC in β cells: More Than Only Recognizing Comestibles

The pathways regulating pancreatic β cell survival in diabetes are poorly understood. Here, Chau et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201701085) demonstrate that mTOR regulates the apoptotic machinery through binding to the ChREBP- Mlx complex to suppress TXN IP, thereby protecting pancreatic β cells in the diabetic setting by inhibiting oxidative stress and mitochondrial dysfunction

MST1 deletion protects β-cells in a mouse model of diabetes

The pro-apoptotic kinase Mammalian Sterile 20-like kinase 1 (MST1), an integral component of the Hippo pathway, is a key regulator of organ size, stress response, and tissue homeostasis; its aberrant hyperactivation is linked to multiple pathological disorders including diabetes. Here we show that MST1 deletion in mice resulted in improved glucose tolerance and insulin secretion, and restored pancreatic β-cell mass as a result of improved β-cell survival and proliferation in the combined high fat/high sucrose and streptozotocin (HFS/STZ) model of β-cell destruction and diabetes. Importantly, the glucose-lowering effects in the MST1-knockout (KO) mice could be accounted to the enhanced β-cell mass and improved insulin secretion without changes in insulin sensitivity. Metabolic and morphological data suggest that normalization of blood glucose and insulin secretion, islet architecture, and β-cell mass by MST1 deletion in response to diabetes-induced injury occurs as a result of improved β-cell survival and proliferation establishing MST1 as potent regulator of physiological β-cell turnover

Deathly triangle for pancreatic β-cells: Hippo pathway-MTORC1-autophagy

A progressive decline in the macroautophagic/autophagic flux is a hallmark of pancreatic β-cell failure in type 2 diabetes (T2D) but the responsible intrinsic factors and underlying molecular mechanisms are incompletely understood. A stress-sensitive multicomponent cellular loop of the Hippo pathway kinase LATS2 (large tumor suppressor 2), MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) and autophagy regulates β-cell survival and metabolic adaptation. Chronic metabolic stress leads to LATS2 hyperactivation which then induces MTORC1, subsequently impairing the cellular autophagic flux and consequently triggering β-cell death. Reciprocally, under physiological conditions, autophagy controls β-cell survival by lysosomal degradation of LATS2. These signaling cross-talks and the interaction between autophagy and LATS2 are important for the regulation of β-cell turnover and functional compensation under metabolic stress

Climbing the cosmic ladder with stellar twins

Distances to stars are key to revealing a three-dimensional view of the Milky Way, yet their determination is a major challenge in astronomy. Whilst the brightest nearby stars benefit from direct parallax measurements, fainter stars are subject of indirect determinations with uncertainties exceeding 30%. We present an alternative approach to measuring distances using spectroscopically-identified twin stars. Given a star with known parallax, the distance to its twin is assumed to be directly related to the difference in their apparent magnitudes. We found 175 twin pairs from the ESO public HARPS archives and report excellent agreement with Hipparcos parallaxes within 7.5%. Most importantly, the accuracy of our results does not degrade with increasing stellar distance. With the ongoing collection of high-resolution stellar spectra, our method is well-suited to complement Gaia.Comment: published online on MNRA

Detection of the melanoma biomarker TROY using silicon nanowire field-effect transistors

Antibody-functionalized silicon nanowire field-effect transistors have been shown to exhibit excellent analyte detection sensitivity enabling sensing of analyte concentrations at levels not readily accessible by other methods. One example where accurate measurement of small concentrations is necessary is detection of serum biomarkers, such as the recently discovered tumor necrosis factor receptor superfamily member TROY (TNFRSF19), which may serve as a biomarker for melanoma. TROY is normally only present in brain but it is aberrantly expressed in primary and metastatic melanoma cells and shed into the surrounding environment. In this study, we show the detection of different concentrations of TROY in buffer solution using top-down fabricated silicon nanowires. We demonstrate the selectivity of our sensors by comparing the signal with that obtained from bovine serum albumin in buffer solution. Both the signal size and the reaction kinetics serve to distinguish the two signals. Using a fast-mixing two-compartment reaction model, we are able to extract the association and dissociation rate constants for the reaction of TROY with the antibody immobilized on the sensor surface