gebhart/patrepeval huggingface dataset:
Evidence for a trimeric organization of the photosystem I complex from the thermophilic cyanobacteriumSynechococcussp. (1987)

A photosystem I (PS I) reaction center complex was isolated and purified from the cyanobacterium Synechococcus sp. The complex has a molecular mass of about 600 kDa and contains 120 Chl a molecules per photoactive Chl a I (P‐700). Electron micrographs show that the PS I complex has the shape of a disk with a diameter of about 19 nm and a thickness of 6 nm. Computer analysis reveals that the complex is composed of three similar units.
Cone-beam computed tomography (CT) for a megavoltage linear accelerator (LINAC) using an electronic portal imaging device (EPID) and the algebraic reconstruction technique (ART) (2002)

This study investigates the feasibility and applicability of cone beam CT for a megavoltage therapeutic LINAC. A Rando head phantom was irradiated using the 15 MV beam of a Varian 2100C LINAC at MSKCC for gantry angles from -102/spl deg/ to 102/spl deg/ with a 2/spl deg/ increment. The projection image for each gantry angle was obtained using a Varian Mark II EPID. Reference images without phantom were also collected at different angles. Pixel readings of each image were converted to dose rate using the EPID calibration curve. The ray sum (sum of linear attenuation coefficients along the ray from the source to a pixel) is calculated as the negative logarithm of the ratio of dose rate of that pixel to that of the corresponding pixel in the reference image. The ray sums were then used for volumetric reconstruction using ART. ART is an iterative method that solves a system of linear equations by iteratively updating the volume to reduce the errors between the measured and calculated ray sums. The authors' results indicate that reasonably good tomographic images can be obtained using projections at every 8/spl deg/, even after only one iteration (typically, 2-3 iterations are used.) The image quality depends on the number of projections and the number of iterations. The reconstruction can be achieved within a reasonable time (/spl sim/2 hours for pure software and /spl sim/5 min with the help of graphics hardware). The authors thus conclude that cone beam CT for megavoltage therapeutic LINAC has a potential to obtain useful tomographic images.
The role of exudation in chronic subdural hematomas (2007)

The exudation rate in chronic SDH is correlated with a higher clinical grade (Markwalder Grade 2 or 3), mixed-density CT appearance, and reaccumulation. Therefore, exudation from macrocapillaries in the outer membrane of chronic SDH probably plays an important role in the pathophysiology and the growth of chronic SDH.
Low ballistic mobility in submicron HEMTs (2002)

Ballistic effects in short channel high electron mobility transistors (HEMTs) greatly reduce the field effect mobility compared to that in long gate structures. This reduction is related to a finite electron acceleration time in the channel under the device gate. As an example, the field effect mobility at room temperature in 0.15-μm gate AlGaAs/GaAs HEMTs cannot exceed 3000 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V-s. These predictions are consistent with the values of the field effect mobility extracted from the measured AlGaAs/GaAs HEMT current-voltage characteristics.
Applying Genetic Programming to Intrusion Detection (1995)

This paper presents a potential solution to the intrusion detection problem in computer security. It uses a combination of work in the fields of Artificial Life and computer security. It shows how an intrusion detection system can be implemented using autonomous agents, and how these agents can be built using Genetic Programming. It also shows how Automatically Defined Functions (ADFs) can be used to evolve genetic programs that contain multiple data types and yet retain type-safety. Future work arising from this is also discussed. Introduction Genetic Programming (GP) has been used to solve many problems that occur in the real world. Koza&amp;apos;s book (Koza 1992) has numerous examples of using GP techniques to solve problems in a variety of fields. This paper presents a new application of genetic programming to solve a problem in the field of computer security. This application will exploit the learning power of GP. In the course of designing a solution to the problem, a novel use for Auto...
The adrenal contribution to the neuroendocrine responses to splanchnic nerve stimulation in conscious calves. (1988)

1. The extent to which the adrenal gland contributes to neuroendocrine responses to electrical stimulation of the peripheral end of the splanchnic nerve has been investigated in conscious calves in which the right nerve was stimulated either at 4 Hz continuously for 10 min or at 40 Hz in 1 s bursts at 10 s intervals for the same period. 2. It was confirmed that the release of neuropeptide Y (NPY) and of gastrin-releasing peptide (GRP) is potentiated by stimulation in bursts at a relatively high frequency and shown that the adrenal gland made a negligible contribution to these responses. 3. There was no detectable change in the concentration of vasoactive intestinal peptide (VIP) in the arterial plasma but the existence of a very small but highly significant rise in the output of VIP from the adrenal provided evidence that it was released within the gland in response to splanchnic nerve stimulation. 4. The concentration of calcitonin gene-related peptide (CGRP) in the arterial and adrenal venous effluent plasma was consistently below the level of detection of the assay. 5. Splanchnic nerve stimulation resulted in an abrupt rise in the output of both free and total met5-enkephalin-like immunoreactivity from the adrenal gland which was substantially potentiated by stimulating in bursts. This pattern of stimulation also increased the proportion released in a high-molecular-weight form. 6. Stimulation in bursts significantly enhanced the output of both adrenaline and noradrenaline from the adrenal and resulted in the release of proportionately more noradrenaline. Small amounts of dopamine and DOPAC were also released during splanchnic nerve stimulation and the output of dopamine was significantly increased by stimulating in bursts. 7. Both patterns of stimulation elicited an abrupt rise in mean plasma adrenocorticotrophic hormone (ACTH) concentration, which was associated with an increase in mean adrenal cortisol output and the former effect was significantly enhanced by stimulating in bursts. 8. It is concluded that certain responses to splanchnic nerve stimulation are significantly potentiated by an intermittent high-frequency pattern of stimulation, including all those that are attributable to adrenal medullary activity, whereas others are apparently unaffected by changes in stimulus pattern.
Detecting Action Potentials in Neuronal Populations with Calcium Imaging (1999)

The study of neural circuits requires methods for simultaneously recording the activity of populations of neurons. Here, using calcium imaging of neocortical brain slices we take advantage of the ubiquitous distribution of calcium channels in neurons to develop a method to reconstruct the action potentials occurring in a population of neurons. Combining calcium imaging with whole-cell or perforated patch recordings from neurons loaded with acetoxymethyl ester or potassium salt forms of calcium indicators, we demonstrate that each action potential produces a stereotyped calcium transient in the somata of pyramidal neurons. These signals are detectable without averaging, and the signal-to-noise is sufficient to carry out a reconstruction of the spiking pattern of hundreds of neurons, up to relatively high firing frequencies. This technique could in principle be applied systematically to follow the activity of neuronal populations in vitro and in vivo.
Coupling Graphene Mechanical Resonators to Superconducting Microwave Cavities (2014)

Graphene is an attractive material for nanomechanical devices because it allows for exceptional properties, such as high frequencies, quality factors, and low mass. An outstanding challenge, however, has been to obtain large coupling between the motion and external systems for efficient readout and manipulation. Here, we report on a novel approach, in which we capacitively couple a high-Q graphene mechanical resonator (Q ≈ 10(5)) to a superconducting microwave cavity. The initial devices exhibit a large single-photon coupling of ∼10 Hz. Remarkably, we can electrostatically change the graphene equilibrium position and thereby tune the single photon coupling, the mechanical resonance frequency, and the sign and magnitude of the observed Duffing nonlinearity. The strong tunability opens up new possibilities, such as the tuning of the optomechanical coupling strength on a time scale faster than the inverse of the cavity line width. With realistic improvements, it should be possible to enter the regime of quantum optomechanics.
Electronic transport studies of single-crystalline In2O3 nanowires (2003)

Single-crystalline In2O3 nanowires were synthesized and then utilized to construct field-effect transistors consisting of individual nanowires. These nanowire transistors exhibited nice n-type semiconductor characteristics with well-defined linear and saturation regimes, and on/off ratios as high as 104 were observed at room temperature. The temperature dependence of the conductance revealed thermal emission as the dominating transport mechanism. Oxygen molecules adsorbed on the nanowire surface were found to have profound effects, as manifested by a substantial improvement of the device performance in high vacuum. Our work paved the way for In2O3 nanowires to be used as nanoelectronic building blocks and nanosensors.
Impulsive noise measurements and characterization in a UHF digital TV channel (1999)

This paper presents the results of a study covering measurement and characterization of the wide-band impulsive noise present in a digital TV radio channel. Measurements were conducted at a frequency of 762 MHz in different outdoor and indoor environments using vertical and horizontal polarization. The measurement system was built on commercial equipment only. The calibration process, which is an important stage of this kind of measurements, is described. To analyze the measurements the impulsive noise has been modeled as a pulse train where the pulse amplitude, pulse duration and elapsed time between pulses are considered random variables. It has been found that the pulse duration and elapsed time between pulses is not dependent on the antenna polarization while the pulse amplitude is, especially in the case of the noise generated by a fluorescent lamp. It has also been found that the pulse duration of the noise measured in the outdoor environments presents some clustering features and is correlated with the pulse amplitudes. This correlation may be caused by a RF noise bandwidth that is larger than the bandwidth of the measurement system. The noise in busy streets presents larger pulse durations, larger amplitude, and shorter elapsed time between pulses that the noise measured in a pedestrian area. Several statistical tests have been done to find the distribution function that best fits these random variables. Power Rayleigh, lognormal, exponential, Poisson, and Gamma distributions have been tested. According to the assessment carried out, none of the distribution functions is adequate to model the pulse amplitudes or the elapsed time between pulses, while the pulse duration seems to be Gamma distributed.
Implementation of a Monte Carlo dosimetry method for patient‐specific internal emitter therapy (1997)

In internal emitter therapy, an accurate description of the absorbed dose distribution is necessary to establish an administered dose-response relationship, as well as to avoid critical organ toxicity. This work describes the implementation of a dosimetry method that accounts for the radionuclide decay spectrum, and patient-specific activity and density distributions. The dosimetry algorithm is based on a Monte Carlo procedure that simulates photon and electron transport and scores energy depositions within the patient. The necessary input information may be obtained from a registered set of CT and SPECT or PET images. The algorithm provides the absorbed dose rate for the radioactivity distribution provided by the SPECT or PET image. The algorithm was benchmarked by reproducing dosimetric quantities using the Medical Internal Radionuclide Dose (MIRD) Committee's Standard Man phantom and was used to calculate absorbed dose distributions for representative case studies.
The identification and control of risk in underground construction (2000)

As the surface areas of cities throughout the world become ever more congested/ and the quality of life deteriorates, those in authority are increasingly turning to the engineering use of created space underground. Transportation systems have been located at least partly underground for generations - particularly in London. Dozens of cities throughout the rest of the world are presently engaged in underground construction, not only for rail transportation schemes, but also for communications purposes, water supply, sewerage, roads, car parks, shopping centres, concert halls, museums and art galleries. Outside the cities underground construction continues to be used for hydro-electric purposes, gas storage, inter-city highways and rail systems, and for nuclear waste storage. This international engineering research study looks at the risks involved in underground construction, and in particular the nature of risks to people directly engaged on this work and to other persons who may be affected by the works and also looks at the nature of risks to the built and natural environment. The study brings together many details of past incidents and disasters that have occurred internationally, and from a broad analysis of the types and causes of failures of one type or another, looks to how such incidents may be prevented in the future. The identification and control of risk in underground engineering projects is seen as the duty and responsibility of all the main parties to the project - the client or promoter of the project, the engineering designers, and those chosen to undertake the construction work. Key components of a broad risk control strategy are described which are applicable regardless of the project's location or what the final purpose of the underground construction work might be. Within this study there are two international Case Studies to illustrate good and poor practice in the identification and control of risk in these types of projects.
Evaluation of 23S rRNA PCR Primers for Use in Phylogenetic Studies of Bacterial Diversity (2006)

The availability of a diverse set of 23S rRNA gene sequences enabled evaluation of the specificity of 39 previously published and 4 newly designed primers specific for bacteria. An extensive clone library constructed using an optimized primer pair resulted in similar gene richness but slightly differing coverage of some phylogenetic groups, compared to a 16S rRNA gene library from the same environmental sample.
DNA binding specificity of a series of cationic metalloporphyrin complexes (1986)

The sequence specificities of a series of cationic metalloporphyrins toward a 139 base pair restriction fragment of pBR-322 DNA have been studied by DNase I footprinting methodology. Analysis using controlled digests and quantitative autoradiography/microdensitometry revealed that the 5- and 6-coordinate complexes of meso-tetrakis(N-methyl-4-pyridiniumyl)porphine, MT4MPyP, where M is Mn, Fe, Co, and Zn, were found to bind to AT regions of DNA. Footprinting analysis involving the radiolabel on the opposing strand of restriction fragment showed site skewing in the direction of the 3' end of the fragment, indicating that the porphyrins bind in the minor groove of DNA. The significant increase in DNase I catalyzed hydrolysis observed in various regions of the fragment appeared to be primarily due to a decrease in available substrate DNA upon porphyrin binding with possible contributions from structural changes in DNA caused by ligand binding. The complexes NiT4MPyP and CuT4MPyP were found to bind to both AT and GC regions of the fragment, producing different degrees of inhibition in the two regions. Since the outside-binding porphyrins can neither intercalate or effectively hydrogen bond to DNA, they appear to read sequence by responding to steric and/or electrostatic potential effects located in the minor groove of DNA.
Reemergence of antibiotic-resistant Staphylococcus aureus in the genomics era (2009)

Staphylococcus aureus is the leading cause of bacterial infections in developed countries and produces a wide spectrum of diseases, ranging from minor skin infections to fatal necrotizing pneumonia. Although S. aureus infections were historically treatable with common antibiotics, emergence of drug-resistant organisms is now a major concern. Methicillin-resistant S. aureus (MRSA) was endemic in hospitals by the late 1960s, but it appeared rapidly and unexpectedly in communities in the 1990s and is now prevalent worldwide. This Review focuses on progress made toward understanding the success of community-associated MRSA as a human pathogen, with an emphasis on genome-wide approaches and virulence determinants.
Molecular Simulation Studies of Protein Interactions with Zwitterionic Phosphorylcholine Self-Assembled Monolayers in the Presence of Water (2008)

Molecular simulations were performed to study the interactions between a protein (lysozyme, LYZ) and phosphorylcholine-terminated self-assembled monolayers (PC-SAMs) in the presence of explicit water molecules and ions. The results show that the water molecules above the PC-SAM surface create a strong repulsive force on the protein as it approaches the surface. The structural and dynamic properties of the water molecules above the PC-SAM surface were analyzed to provide information regarding the role of hydration in surface resistance to protein adsorption. It can be seen from residence time dynamics that the water molecules immediately above the PC-SAM surface are significantly slowed down as compared to bulk water, suggesting that the PC-SAM surface generates a tightly bound, structured water layer around its head groups. Moreover, the orientational distribution and reorientational dynamics of the interfacial water molecules near the PC-SAM surface were found to have the ionic solvation nature of the PC head groups. These properties were also compared to those obtained previously for an oligo(ethylene glycol) (OEG) SAM system and bulk water.
Control of Aragonite or Calcite Polymorphism by Mollusk Shell Macromolecules (1996)

Many mineralizing organisms selectively form either calcite or aragonite, two polymorphs of calcium carbonate with very similar crystalline structures. Understanding how these organisms achieve this control has represented a major challenge in the field of biomineralization. Macromolecules extracted from the aragonitic shell layers of some mollusks induced aragonite formation in vitro when preadsorbed on a substrate of β-chitin and silk fibroin. Macromolecules from calcitic shell layers induced mainly calcite formation under the same conditions. The results suggest that these macromolecules are responsible for the precipitation of either aragonite or calcite in vivo.
Functional Lactide Monomers:  Methodology and Polymerization (2006)

Side-chain-functionalized lactide analogues have been synthesized from commercially available amino acids and polymerized using stannous octoate as a catalyst. The synthetic strategy presented allows for the incorporation of any protected amino acid for the preparation of functionalized diastereomerically pure lactide monomers. The resulting functionalized cyclic monomers can be homopolymerized and copolymerized with lactides and then quantitatively deprotected forming new functional poly(lactide)-based materials. This strategy allows for the introduction of functional groups along a poly(lactide) (PLA) backbone that after deprotection can be viewed as chemical handles for further functionalization of PLA, yielding improved biomaterials for a variety of applications.
Personal recognition using hand shape and texture (2006)

This paper proposes a new bimodal biometric system using feature-level fusion of hand shape and palm texture. The proposed combination is of significance since both the palmprint and hand-shape images are proposed to be extracted from the single hand image acquired from a digital camera. Several new hand-shape features that can be used to represent the hand shape and improve the performance are investigated. The new approach for palmprint recognition using discrete cosine transform coefficients, which can be directly obtained from the camera hardware, is demonstrated. None of the prior work on hand-shape or palmprint recognition has given any attention on the critical issue of feature selection. Our experimental results demonstrate that while majority of palmprint or hand-shape features are useful in predicting the subjects identity, only a small subset of these features are necessary in practice for building an accurate model for identification. The comparison and combination of proposed features is evaluated on the diverse classification schemes; naive Bayes (normal, estimated, multinomial), decision trees (C4.5, LMT), k-NN, SVM, and FFN. Although more work remains to be done, our results to date indicate that the combination of selected hand-shape and palmprint features constitutes a promising addition to the biometrics-based personal recognition systems.
Advanced virtual texture topics (2008)

A virtual texture is a mip-mapped texture used as cache to allow a much higher resolution texture to be emulated for real-time rendering, while only partly residing in texture memory. This functionality is already accessible with the efficient pixel shader capabilities available on the recent generations of commodity GPUs. In this chapter we will be discussing technical implications on engine design due to virtual textures use, content creation issues, results, performance and image quality. We will also cover several practical examples to highlight the challenges and to offer solutions. These include texture filtering, block compression, float precision, disk streaming, UV borders, mip-map generation, LOD selection and more.
Purification of a serine kinase that associates with and phosphorylates human Cdc25C on serine 216. (1994)

Human Cdc25C is a protein phosphatase that dephosphorylates and activates Cdc2-cyclin B to trigger entry into mitosis. Cdc25C is itself regulated by phosphorylation. In asynchronously growing HeLa cells, we have determined that serine 216 is the major site of Cdc25C phosphorylation. We have isolated a protein kinase that binds to Cdc25C and phosphorylates serine 216. The kinase binds within amino acids 200-256 of Cdc25C. This region is conserved in some Cdc25 homologues and contains a putative bipartite nuclear localization signal just downstream from serine 216. Finally, the Cdc25C-associating kinase was purified over 8000-fold from rat liver as a 36-38-kDa doublet of proteins.
The antigen receptor on a human T cell line initiates activation by increasing cytoplasmic free calcium. (1985)

A monoclonal antibody to the antigen-receptor on the T cell line Jurkat induces substantial increases in [Ca++]i. Ca++ ionophores can substitute for this antibody in activation by increasing [Ca++]i to levels comparable with those seen with the antigen-receptor antibody. Stimulation with either the antigen-receptor antibody or a Ca++ ionophore leads to the appearance of the same phosphoproteins. These results suggest that the antigen-receptor initiates T cell activation by increasing [Ca++]i.