gebhart/patrepeval huggingface dataset:
Perinatal abrogation of Cdk5 expression in brain results in neuronal migration defects (2004)

Cyclin-dependent kinase 5 (Cdk5) is essential for the proper development of the CNS, as is evident from the perinatal lethality of conventional Cdk5 knockout (Cdk5-/-) mice. Cdk5 is also implicated in numerous complex functions of the adult CNS such as synaptic transmission, synaptic plasticity, and neuronal signaling. To elucidate the molecular roles of Cdk5 in the adult CNS, we have abrogated neuronal expression of Cdk5 in perinatal mice by using a cre-loxP system. The Cdk5-loxP flanked mice were crossed with the cre-transgenic mice in which the cre expression is driven by the murine neurofilament-heavy chain promoter, resulting in generation of viable Cdk5 conditional knockout mice with the restricted deletion of the Cdk5 gene in specific neurons beginning around embryonic day 16.5. Twenty-five percent of the Cdk5 conditional knockout mice carrying the heterozygous cre allele had neuronal migration defects confined to brain areas where neuronal migration continues through the perinatal period. These results indicate that abrogation of Cdk5 expression in mature neurons results in a viable mouse model that offers further opportunities to investigate the molecular roles of Cdk5 in the adult CNS.
Analysis of Non Ambiguous BOC Signal Acquisition Performance (2004)

The Binary Offset Carrier planned for future GNSS signals, including several GALILEO signals as well as GPS M-code, presents a high degree of spectral separation from conventional signals. It also greatly improves positioning accuracy and enhances multipath rejection. However, with such a modulation, the acquisition process is made more complex. Specific techniques must be employed in order to avoid unacceptable errors. This paper assesses the performance of three methods allowing to acquire and track a BOC signal unambiguously : the Bump-Jumping technique, the ”BPSK-like” technique, and the Sub Carrier Phase Cancellation (SCPC) technique. A detailed study of these methods is developed taking into accounts the filtering effects. In order to validate the theoretical results, intensive simulations have been carried out and performance of BOC signal acquisition for the different methods have been assessed and compared with initial theoretical analysis.
Wireless temperature sensor for condition monitoring of mechanical seals (2012)

This paper presents the first RF temperature sensor for condition monitoring of mechanical face seals. The sensor comprises a resonant inductor-capacitor circuit that is inductively coupled to a separate interrogating coil. The resonant circuit is mounted on the stationary face of the mechanical seal. A temperature rise is sensed as a resonant frequency increase, caused by a decrease in the sensor capacitance value. The resonant sensor is implemented using commercially-available components and has a footprint of less than 5.12 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Despite the very close proximity to the steel shaft (0.79 mm) and the stainless steel flange (2 mm), successful interrogation is achieved and the sensor's frequency is increased linearly from 41.1 MHz to 41.6 MHz for a temperature increase from 25°C to 80°C. The measurements are verified by simulating the system using a combination of HFSS-ADS EM-circuit co-simulation model. The uncertainty in the measurements with respect to calibration equation was less than ±5%.
ChemInform Abstract: REDUCTIVE ELIMINATION OF A CARBON‐CARBON BOND FROM BIS(TRIALKYLPHOSPHINE)‐3,3‐DIMETHYLPLATINACYCLOBUTANES PRODUCES BIS(TRIALKYLPHOSPHINE)PLATINUM(0) AND 1,1‐DIMETHYLCYCLOPROPANE (1982)

Abstract Die Bis‐[trialkylphosphin]‐platinacyclobutane (II) werden durch l:2‐molare Umsetzung von Dineopentylcyclooctadien‐Pt(II) (I) mit den tert. Phosphinen dargestellt.
Barriers and paths to market for genetically engineered crops (2009)

Each year, billions of dollars are invested in efforts to improve crops through genetic engineering (GE). These activities have resulted in a surge of publications and patents on technologies and genes: a momentum in basic research that, unfortunately, is not sustained throughout the subsequent phases of product development. After more than two decades of intensive research, the market for transgenic crops is still dominated by applications of just a handful of methods and genes. This discrepancy between research and development reflects difficulties in understanding and overcoming seven main barriers-to-entry: (1) trait efficacy in the field, (2) critical product concepts, (3) freedom-to-operate, (4) industry support, (5) identity preservation and stewardship, (6) regulatory approval and (7) retail and consumer acceptance. In this review, I describe the various roadblocks to market for transgenic crops and also discuss methods and approaches on how to overcome these, especially in the United States.
Impact Ionization Coefficients in 4H-SiC (2008)

Photomultiplication measurements using 244- and 325-nm excitation have been undertaken on a series of thick 4H-SiC avalanche diodes. With avalanche widths of between 2.7 and 6 mum and the ability to measure multiplication as low as 1.001, a much wider electric field range has been covered than reported to date. The results show that the hole ionization coefficient (beta) can be obtained with a high degree of accuracy down to electric fields as low as ~0.9 MV/cm. The value of electron ionization coefficient (alpha) has been determined from mixed carrier multiplication characteristics, and the beta/alpha ratio is found to increase significantly with decreasing electric fields. Ionization coefficients are parameterized over the electric field range from 0.9 to 5 MV/cm, enabling the multiplication and breakdown characteristics of 4H-SiC to be predicted accurately.
Surface-emitting laser technology and its application to the space radiation environment (1997)

Present and future space-based applications such as sensors, low-weight and low-power data links for satellites, communication between electromagnetically-shielded modules, and short-distance cross-links within satellite constellations may benefit from the inclusion of small, low-power, and high-efficiency lasers such as the recently-developed Vertical Cavity Surface-Emitting Laser (VCSEL). Many factors influence the application of these devices to space. Temperature response, operational lifetime and reliability, and power consumption are all important considerations for space applications. In addition, the space radiation environments must be considered. In this work, the effects of ionizing radiation on VCSELs are studied with an emphasis on proton damage, and with comparisons to related neutron and gamma-induced phenomena. The influence of proton irradiation is studied in-depth for selected VCSEL structures by the use of an ion microbeam. The experiments indicate that VCSELs exhibit much less threshold current shift for a given radiation dose, compared to the more traditional edge-emitting semiconductor lasers, but that self-heating is a more important consideration for VCSELs. The high current densities associated with VCSELs also lead to a strong influence from forward-bias annealing. These effects are common to various VCSEL types (780 nm and 850 nm) and their magnitude at a given dose is strongly dependent on device size. This indicates that, while VCSELs appear to be very insensitive to ionizing radiation when compared with alternative technologies, there are a number of factors that must be taken into account when optimizing for the space environment.
Direct numerical simulation of a 30R long turbulent pipe flow at Re τ = 3008 (2015)

A direct numerical simulation of a turbulent pipe flow at a high Reynolds number of Reτ = 3008 over a long axial domain length (30R) was performed. The streamwise mean velocity followed the power law in the overlap region (y+ = 90–300; y/R = 0.03–0.1) based on the power law indicator function. The scale separation of the Reynolds shear stresses into two components of small- and large-scale motions (LSMs) revealed that the LSMs in the outer region played an important role in constructing the constant-stress layer and the mean velocity. In the pre-multiplied energy spectra of the streamwise velocity fluctuations, the bimodal distribution was observed at both short and long wavelengths. The kx−1 region associated with the attached eddies appeared in λx/R = 2–5 and λx/y = 18–160 at y+ = 90–300, where the power law was established in the same region. The kz−1 region also appeared in λz/R = 0.3–0.6 at y+ = 3 and 150. Linear growth of small-scale energy to large-scale energy induced the kx−1 region at high Reynolds numbers, resulting in a large population of the LSMs. This result supported the origin of very-large-scale motions in the pseudo-streamwise alignment of the LSMs. In the pre-multiplied energy spectra of the Reynolds shear stress, the bimodal distribution was observed without the kx−1 region.
Electrification Potential of Fuel-Based Vehicles and Optimal Placing of Charging Infrastructure: A Large-Scale Vehicle-Telematics Approach (2021)

As apprehension grows over global warming and urban pollution, battery electric vehicles (BEVs) are experiencing a rise in worldwide popularity. Yet, their market uptake has been slowed down due to high purchase prices and concerns over the limited battery range and the insufficient public charging infrastructure. This work uses a massive real-world dataset, containing the anonymized global positioning system (GPS) traces from a fleet of private vehicles, to quantitatively evaluate if range anxiety (i.e., the fear of being stranded due to EV’s limited range) is a rational concern. In particular, the fleet’s electrification potential is assessed by analyzing the driving patterns of more than 50000 vehicles over the course of an entire year. The results reveal the potential of BEVs, which could satisfy the range needs of much of the existing fuel-powered vehicle fleet with no alteration to the owners’ routines (except for overnight recharging). Furthermore, the mileage analysis is later used to pinpoint the so-called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eligible stops</i> (ESs), corresponding to real charging demand and opportunities. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ESs</i> are aggregated through clustering analysis, obtaining a ranking of potential charging station sites. Finally, we quantitatively evaluate the effects of the increasing dissemination of charging facilities on the vehicles’ EV-switch suitability.
DoF Analysis of the K-user MISO Broadcast Channel with Alternating CSIT (2013)

We consider a $K$-user multiple-input single-output (MISO) broadcast channel (BC) where the channel state information (CSI) of user $i(i=1,2,\ldots,K)$ may be either perfect (P), delayed (D) or not known (N) at the transmitter with probabilities $λ_P^i$, $λ_D^i$ and $λ_N^i$, respectively. In this channel, according to the three possible CSIT for each user, joint CSIT of the $K$ users could have at most $3^K$ realizations. Although the results by Tandon et al. show that the Degrees of Freedom (DoF) region for the two user MISO BC with symmetric marginal probabilities (i.e., $λ_Q^i=λ_Q \forall i\in \{1,2,\ldots,K\}, Q\in \{P,D,N\}$) depends only on the marginal probabilities, we show that this interesting result does not hold in general when the number of users is more than two. In other words, the DoF region is a function of the \textit{CSIT pattern}, or equivalently, all the joint probabilities. In this paper, given the marginal probabilities of CSIT, we derive an outer bound for the DoF region of the $K$-user MISO BC. Subsequently, the achievability of these outer bounds are considered in certain scenarios. Finally, we show the dependence of the DoF region on the joint probabilities.
Signal-to-noise ratio improvement of photonic time-stretch coherent radar enabling high-sensitivity ultrabroad W-band operation (2018)

The signal-to-noise ratio (SNR) of the photonic time-stretching receiver in the photonic time-stretch coherent radar (PTS-CR) system is theoretically analyzed. According to the analysis based on the erbium-doped fiber amplifier (EDFA) characteristic, it is found that the SNR is dominantly determined by the input optical power of the EDFA. With the improvement of the SNR of the photonic time-stretching receiver, the radar detection sensitivity is consequently enhanced. Furthermore, a PTS-CR system operating at W band with the ultrabroad bandwidth of 12 GHz is experimentally enabled, leading to the range resolution of ∼1.48 cm in dual-target detection.
Straightforward Access to Stable, 16-Valence-Electron Phosphine-Stabilized Fe0 Olefin Complexes and Their Reactivity (2017)

The use of the dialkene divinyltetramethyldisiloxane (dvtms) allows easy access to the reactive 16 valence-electron complexes [Fe<sup>0</sup>(L-L)(dvtms)], (L-L) = dppe (1,2-bis(diphenylphosphino)ethane), (<b>1</b>), dppp (1,2-bis(diisopropylphosphino)propane), (<b>2</b>), pyNMeP(<sup>i</sup>Pr)<sub>2</sub> (N-(diisopropylphosphino)-N-methylpyridin-2-amine), (<b>4</b>), dipe (1,2-bis(diisopropylphosphino)ethane), (<b>5</b>), and [Fe<sup>0</sup>(L)<sub>2</sub>(dvtms)], L = PMe<sub>3</sub>, (<b>3</b>), by a mild reductive route using AlEt<sub>2</sub>(OEt) as reducing agent. In contrast, by the same methodology, the 18 valence-electron complexes [Fe<sup>0</sup>(L-L)<sub>2</sub>(ethylene)], (L-L) = dppm (1,2-bis(diphenylphosphino)methane), <b>6</b>, (L-L) = dppa (1,2-bis(diphenylphosphino)amine) <b>7</b> or (L-L)=dppe, <b>8</b>, were obtained, which do not contain dvtms. In addition, a combined DFT and solid-state paramagnetic NMR methodology is introduced for the structure determination of <b>5</b>. A comparative study of the reactivity of <b>1</b>,<b>2</b>,<b>4</b>-<b>6</b> and <b>8</b> with 3-hexyne highlights emerging mechanistic implications for C-C coupling reactions using these complexes as catalysts.
Phylogenetically Novel LuxI/LuxR-Type Quorum Sensing Systems Isolated Using a Metagenomic Approach (2012)

A great deal of research has been done to understand bacterial cell-to-cell signaling systems, but there is still a large gap in our current knowledge because the majority of microorganisms in natural environments do not have cultivated representatives. Metagenomics is one approach to identify novel quorum sensing (QS) systems from uncultured bacteria in environmental samples. In this study, fosmid metagenomic libraries were constructed from a forest soil and an activated sludge from a coke plant, and the target genes were detected using a green fluorescent protein (GFP)-based Escherichia coli biosensor strain whose fluorescence was screened by spectrophotometry. DNA sequence analysis revealed two pairs of new LuxI family N-acyl-L-homoserine lactone (AHL) synthases and LuxR family transcriptional regulators (clones N16 and N52, designated AubI/AubR and AusI/AusR, respectively). AubI and AusI each produced an identical AHL, N-dodecanoyl-L-homoserine lactone (C(12)-HSL), as determined by nuclear magnetic resonance (NMR) and mass spectrometry. Phylogenetic analysis based on amino acid sequences suggested that AusI/AusR was from an uncultured member of the Betaproteobacteria and AubI/AubR was very deeply branched from previously described LuxI/LuxR homologues in isolates of the Proteobacteria. The phylogenetic position of AubI/AubR indicates that they represent a QS system not acquired recently from the Proteobacteria by horizontal gene transfer but share a more ancient ancestry. We demonstrated that metagenomic screening is useful to provide further insight into the phylogenetic diversity of bacterial QS systems by describing two new LuxI/LuxR-type QS systems from uncultured bacteria.
New Orbit Determination and Clock Synchronisation Modules for EGNOS (2016)

The purpose of a Satellite Based Augmentation System (SBAS), such as EGNOS or WAAS, is to identify all range error sources and to distribute the corresponding corrections to the civil aviation user community with reliable navigation services for different flight phases. The effect of a satellite location error depends on the user location while a satellite clock error with respect to a reference time scale directly translates into a common pseudorange error to all the users. Therefore the SBAS shall broadcast a 3D vector that represents the satellite orbit error and a satellite clock correction. To achieve this objective the SBAS shall internally estimate the orbits and clocks for all the navigation satellites in view of the service area. The orbit determination function is in charge of computing the satellite ephemerides. The synchronization function computes the corresponding clock bias for each epoch and each satellite. Then the corrections are constructed from the differences between these orbits and clocks and the corresponding ones broadcasted inside the GNSS navigation messages. Starting from R&D activities, Thales Alenia Space has developed new orbit determination and synchronization modules that are part of the Thales Algorithm Navigation Chain. These modules have been designed in collaboration with the orbit determination team at CNES (the French Space Agency). The new proposed orbit determination module is based on real time processing using code carrier measurement only. This module provides a stable and metric GPS orbit performance using an SBAS set of receivers corresponding to the EGNOS service area. The new synchronization module solves clock errors directly steered to GPS reference time scale, for the stations and satellites. It uses both code carrier and phase carrier measurements as well as the orbits estimated by the orbit determination process. The clocks solution error Allan’s deviation is around 10-12 at 120s leading to 7cm of possible deviation for a prediction up to 120s. This performance is fully compatible with the needs of the SBAS mission. These modules are now fully integrated into the SPEED platform, the SBAS Operational Test-bed that fully represents EGNOS Performances in terms of accuracy, continuity, availability and integrity for Safety Of Life services. The performance evaluation shows a real improvement over the current EGNOS algorithms, particularly in terms of the distribution of the Satellite Residual Error for the Worst user location (SREW). This paper provides a high level architecture description of this new Thales solution. A set of performance figures showing the achieved improvements is also presented.
Hypoglossal motoneuron pathology in a mouse model of Pompe disease (2011)

Pompe disease is a lysosomal storage disorder associated with acid α‐glucosidase (GAA) deficiency. Both diaphragm and upper airway muscle dysfunction occur in Pompe disease and this may reflect central nervous system (CNS) pathology. We used a murine model of Pompe disease to test the hypothesis that systemic GAA deficiency is associated with hypoglossal (XII) motoneuron pathology and altered XII motor output. Brainstem tissue was harvested from adult Gaa − / − mice and the periodic acid Schiff (PAS) method was used to examine neuronal glycogen accumulation. Semi‐thin (2 μm) plastic sections showed extensive cytoplasmic glycogen accumulation in XII motoneuron soma. Phrenic and XII bursting was recorded in anesthetized and ventilated Gaa − / − and B6/129 mice before and after bilateral vagotomy. Vagotomy caused a robust increase in XII inspiratory burst amplitude in B6/129 mice (238 ± 44 %baseline; P &lt; 0.01) but had little impact on burst amplitude in Gaa − / − mice (130 ± 23 %baseline; P &gt; 0.05). Regression analysis revealed that phrenic and XII burst amplitudes were significantly correlated in B6/129 ( r 2 = 0.27, P &lt; 0.05) but not Gaa − / − mice ( r 2 = 0.08, P = 0.27). This finding may indicate that the progression of neuropathology differs between XII and phrenic motoneurons in Gaa − / − mice. We conclude that CNS GAA deficiency is associated with glycogen accumulation in XII motoneuron cell bodies and altered XII motor output.
Two‐Photon Polarity Probes Built from Octupolar Fluorophores: Synthesis, Structure–Properties Relationships, and Use in Cellular Imaging (2013)

A series of octupolar fluorophores built from a triphenylamine (TPA) core connected to electron-withdrawing (EW) peripheral groups through conjugated spacers has been synthesized. Their photoluminescence, solvatochromism, and two-photon absorption (2PA) properties were systematically investigated to derive structure-property relationships. All derivatives exhibit two 2PA bands in the 700-1000 nm region: a first band at low energy correlated with a core-to-periphery intramolecular charge transfer that leads to an intense 1PA in the blue-visible range, and a second more intense band at higher energy due to an efficient coupling of the branches through the TPA core. Increasing the strength of the EW end groups or the length of the conjugated spacers and replacing triple-bond linkers with double bonds induces both enhancement and broadening of the 2PA responses, thereby leading to cross-sections up to 2100 GM at peak and higher than 1000 GM over the whole 700-900 nm range. All derivatives exhibit intense photoluminescence (PL) in low- to medium-polarity environments (with quantum yields in the 0.5-0.9 range) and display a strong positive solvatochromic behavior (with Lippert-Mataga specific shifts ranging from 15,000 to 27,500 cm(-1)), triple bonds, and phenyl moieties in the conjugated spacers, thereby leading to larger sensitivities than those of double bonds and thienyl moieties. More hydrophilic derivatives were also shown to be biocompatible, to retain their 2PA and PL properties in biological conditions, and finally to be suitable as polarity sensors for multiphoton cell imaging.
Rear-surface laser damage on 355-nm silica optics owing to Fresnel diffraction on front-surface contamination particles (2000)

Light intensity modulations caused by opaque obstacles (e.g., dust) on silica lenses in high-power lasers often enhance the potential for laser-induced damage. To study this effect, particles (10-250 mum) with various shapes were sputter deposited on the input surface and irradiated with a 3-ns laser beam at 355 nm. Although a clean silica surface damages at fluences above 15 J/cm(2), a surface contaminated with particles can damage below 11.5 J/cm(2). A pattern that conforms to the shape of the input surface particle is printed on the output surface. Repetitive illumination resulted in catastrophic drilling of the optic. The damage pattern correlated with an interference image of the particle before irradiation. The image shows that the incident beam undergoes phase (and amplitude) modulations after it passes around the particle. We modeled the experiments by calculating the light intensity distribution behind an obscuration by use of Fresnel diffraction theory. The comparison between calculated light intensity distribution and the output surface damage pattern showed good agreement. The model was then used to predict the increased damage vulnerability that results from intensity modulations as a function of particle size, shape, and lens thickness. The predictions provide the basis for optics cleanliness specifications on the National Ignition Facility to reduce the likelihood of optical damage.
ChemInform Abstract: Enantioselective Total Synthesis of Doliculide, a Potent Cytotoxic Cyclodepsipeptide of Marine Origin and Structure‐Cytotoxicity Relationships of Synthetic Doliculide Congeners. (1995)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.