gebhart/patrepeval huggingface dataset:
MOLECULAR PHYSIOLOGY OF INTESTINAL N+/H+ EXCHANGE (2004)

The sodium/hydrogen exchange (NHE) gene family plays an integral role in neutral sodium absorption in the mammalian intestine. The NHE gene family is comprised of nine members that are categorized by cellular localization (i.e., plasma membrane or intracellular). In the gastrointestinal (GI) tract of multiple species, there are resident plasma membrane isoforms including NHE1 (basolateral) and NHE2 (apical), recycling isoforms (NHE3), as well as intracellular isoforms (NHE6, 7, 9). NHE3 recycles between the endosomal compartment and the apical plasma membrane and functions in both locations. NHE3 regulation occurs during normal digestive processes and is often inhibited in diarrheal diseases. The C terminus of NHE3 binds multiple regulatory proteins to form large protein complexes that are involved in regulation of NHE3 trafficking to and from the plasma membrane, turnover number, and protein phosphorylation. NHE1 and NHE2 are not regulated by trafficking. NHE1 interacts with multiple regulatory proteins that affect phosphorylation; however, whether NHE1 exists in large multi-protein complexes is unknown. Although intestinal and colonic sodium absorption appear to involve at least NHE2 and NHE3, future studies are necessary to more accurately define their relative contributions to sodium absorption during human digestion and in pathophysiological conditions.
Sequence analysis of the gene encoding the Chlamydia pneumoniae DnaK protein homolog (1991)

The antigen-coding region of a 4.2-kb PstI fragment of Chlamydia pneumoniae (pLC3), which encodes a 75-kDa immunoreactive protein recognized during human C. pneumoniae infection, was localized to a 2.0-kb EcoRI fragment. This subclone expressed an immunoreactive fusion protein of ca. 82 kDa. Nucleotide sequence analysis of the C. pneumoniae gene revealed that it consisted of a 1,980-base open reading frame with an inferred 71,550-Da protein of 660 amino acids. Putative Escherichia coli-like promoters and a ribosomal binding site were located in the 5' upstream region, and an 11-base dyad forming a stable stem-loop structure following two in-frame stop codons was identified. The C. pneumoniae 75-kDa protein is a member of the hsp70 family of heat shock proteins and has 87% amino acid similarity with the Chlamydia trachomatis protein.
Channel Estimation and Data Detection for MIMO-OFDM Systems (2004)

The use of multiple antennas at both the transmitter and receiver can significantly increase the channel capacity. These systems are called the multiple-input multiple-output (MIMO) systems. By using orthogonal frequency division multiplexing (OFDM) transmission techniques, the MIMO-OFDM system can achieve high spectral efficiency, which makes it an attractive candidate for high-data-rate wireless applications. In this paper, we propose a convolutionally coded MIMO-OFDM system with EM-based channel estimation and a QRD-M data detection algorithm. In our systems, one training symbol is transmitted from each transmit antenna for the MIMO channel estimation at the receiver. With the channel estimates available, we apply the QRD-M algorithm on the estimated channel matrix for suboptimal data detection with reasonable computational cost. The bit error rate (BER) and packet error rate (PER) performance of the MIMO-OFDM systems are compared. In the simulations, the bit error rate performance of our systems is 9 (or 5) dB better than that of uncoded (or coded) BLAST systems.
Properties of GaAs on Si grown by molecular beam epitaxy (1990)

Abstract For several years, there has been a great deal of activity in the growth of GaAs and other compounds on Si substrates for several reasons. Among them are the high quality, low cost, high thermal conductivity, and mechanical strength offered by Si substrates. For example, if we compare the cost of GaAs and Si wafers, the Si substrate can be regarded as free. Presently, 3 in. is the maximum GaAs wafer diameter in comparison to the current 8-in. and expected 10-in. Si wafer sizes. The growth of GaAs on such Si wafers is an advantageous way of growing GaAs on large-diameter wafers. But the second, and most exciting motivation for GaAs on Si, is the hybridization of Si and GaAs technologies on the same wafer. GaAs and Si technology are highly complementary and compatible. The advantage of Si over GaAs is its highly developed processing technology and the very high integration density of circuits available. The advantage of GaAs over Si is its intrinsically higher performance potential and its optical properties. Therefore, the value of hybridization of GaAs and Si technologies is apparent. For example, this system is well suited for optical off-chip communication and one can imagine a single chip where the high speed devices and optical inputs and outputs are driven by GaAs devices and the highly integrated part of the circuits are in Si technology.
Cloning, Purification, and Characterization of the Shigella boydii dGTP Triphosphohydrolase (1997)

The nucleotide sequence of the Shigella boydii dgt gene, which encodes the enzyme deoxyguanosine triphosphate triphosphohydrolase (dGTPase, EC 3.1.5.1), has been determined. The 1515-nucleotide Shigella dgt open reading frame has been subcloned into a T7 RNA polymerase-based expression vector. The resulting expressed protein has been purified to homogeneity using a novel single-day chromatographic regime. The protocol includes ion exchange, affinity, and hydrophobic interaction chromatography. The purified 505-amino acid (59.4 kDa) protein exists in solution as a heat-stable homotetramer, and enzymatic assays reveal that the expressed enzyme is fully active. Substrate specificity can be explained by the array of potential hydrogen bond donors/acceptors displayed on the base moiety of the (deoxy)nucleoside triphosphate. Shigella dGTPase can be inhibited by the addition of stoichiometric amounts of reducing agents. The loss of activity is both time- and concentration-dependent and is accompanied by a decrease in the thermal stability of the enzyme. Shigella dGTPase in the fully reduced form is destabilized by 1.8 kcal/mol compared with the oxidized form. Hence, disulfide bonds play a pivotal role in the maintenance of dGTPase stability and enzymatic functionality. Initial Shigella dGTPase protein crystals have been formed.
Providing information systems with full hypermedia functionality (2002)

The architecture of a system-level hypermedia engine, designed both to manage full hypermedia functionality for an information system and to bind interface-oriented front-end systems is presented. The engine dynamically superimposes a hypermedia representation over a back-end application's knowledge components and processes. A set of minimal requirements for integrating the hypermedia engine is described. The more sophisticated and cooperative the information system, the higher the level of hypermedia support the engine will provide.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Genetic Risk of Age-related Maculopathy (1998)

First-degree relatives of patients with late ARM developed ARM at an increased rate at a relatively young age. Our findings indicate that approximately one fourth of all late ARM is genetically determined and suggest that genetic susceptibility may play an important role in determining the onset of disease.
Transforming growth factor β-induced phosphorylation of Smad3 is required for growth inhibition and transcriptional induction in epithelial cells (1997)

Drosophila Mad proteins are intracellular signal transducers of decapentaplegic (dpp), the Drosophila transforming growth factor beta (TGF-beta)/bone morphogenic protein (BMP) homolog. Studies in which the mammalian Smad homologs were transiently overexpressed in cultured cells have implicated Smad2 in TGF-beta signaling, but the physiological relevance of the Smad3 protein in signaling by TGF-beta receptors has not been established. Here we stably expressed Smad proteins at controlled levels in epithelial cells using a novel approach that combines highly efficient retroviral gene transfer and quantitative cell sorting. We show that upon TGF-beta treatment Smad3 becomes rapidly phosphorylated at the SSVS motif at its very C terminus. Either attachment of an epitope tag to the C terminus or replacement of these three serine residues with alanine abolishes TGF-beta-induced Smad3 phosphorylation; these proteins act in a dominant-negative fashion to block the antiproliferative effect of TGF-beta in mink lung epithelial cells. A Smad3 protein in which the three C-terminal serines have been replaced by aspartic acids is also a dominant inhibitor of TGF-beta signaling, but can activate plasminogen activator inhibitor 1 (PAI-1) transcription in a ligand-independent fashion when its nuclear localization is forced by transient overexpression. Phosphorylation of the three C-terminal serine residues of Smad3 by an activated TGF-beta receptor complex is an essential step in signal transduction by TGF-beta for both inhibition of cell proliferation and activation of the PAI-1 promoter.
Holding the Door Open : Facilitating Access to Microcredit in the Benin Social Fund (2002)

During preparation of the Benin Social&#13;\n Fund Project, all levels of society indicated that lack of&#13;\n access to credit was a major problem for poor people. At the&#13;\n same time, there was reluctance to put in a micro-credit&#13;\n component, as an assessment of this type of component in&#13;\n social funds had yielded mixed results. The Bank was already&#13;\n supporting the Second Rural Credit Project, providing&#13;\n technical support to a national association of cooperative&#13;\n savings and credit societies to increase the availability of&#13;\n credit. Nonetheless, the Government, having identified&#13;\n micro-credit as a priority, was keen to have micro-credit&#13;\n activities. To balance the somewhat conflicting points of&#13;\n view, the project team decided to develop financial&#13;\n intermediation services for low-income groups, without&#13;\n providing the actual credit. To take into account the&#13;\n heterogeneity of institutions involved in microfinance at&#13;\n the time, the unequal distribution of financial services in&#13;\n the country (especially urban/rural), and the&#13;\n characteristics of different types of clients, the&#13;\n microfinance component was divided into three&#13;\n sub-components, two dealing with formal financial systems,&#13;\n the other with informal ones. The project has been able to&#13;\n fill a gap between poor households and formal credit&#13;\n sources. Critical for the success were the already-existing&#13;\n formal credit organizations that offered financial services&#13;\n relevant to the needs of poor groups. While expertise on&#13;\n microfinance is hard to find, results suggest that&#13;\n intermediation only works where credit is actually&#13;\n available, in a form usable by the target population.&#13;\n Notably, targets should be adjusted to focus on what is&#13;\n important to the beneficiaries.
Mixture Analysis Using a Quadrupole Mass Filter/Quadrupole Ion Trap Mass Spectrometer (1996)

A hybrid tandem mass spectrometer is constructed by interfacing a quadrupole mass filter (Q) to a quadrupole ion trap mass spectrometer (QITMS) and is evaluated for the analysis of mixtures. The mass filter is set to selectively inject ions of a particular m/z or, in scanning mode, to sequentially inject ions into the QITMS for subsequent manipulation and detection. Performance of the instrument is demonstrated using a mixture of ions created by electron impact ionization of perfluorotributylamine (FC-43) and peptide ions generated by pulsed Cs+ bombardment. Resulting data are compared to those obtained by utilizing only the ion trap. Molecular weight, fragmentation, and high-resolution analyses for the sequentially injected mass-filtered peptides show improved performance over similar measurements employing only the ion trap mass spectrometer. Performance is optimized when ions are not rf-isolated in the QITMS. Using the hybrid, a resolution of 33 200 is achieved for angiotensin I. Dramatic reduction of space charge-induced signal suppression is demonstrated for LSIMS of Glu-fibrinopeptide B. “On-the-fly” collision-induced dissociation is performed for m/z 502 from FC-43, where fragmentation is induced by increasing the ion injection energy. Collision-induced dissociation efficiencies for fragmentation of angiotensin I by resonance excitation are investigated as a function of cooling time for different modes of operation of the hybrid. A current limitation of the instrument is the time required to port the data for acquisition.
Computer‐Aided Learning for All (1975)

Abstract Rising costs reduce the probability of achieving equal educational opportunities through traditional instructional systems. How can every person be given the opportunity of salutary instructional dialogue characterised by individual attention? This article describes the confluence of several streams of research and development, the potential of which is exciting. The design philosophy for a computer‐based educational co‐operative is portrayed. Although this yields computer‐aided learning materials and a national authoring language, the development of specialised hardware and system software is especially noteworthy. A multi‐media intelligent terminal is described—a silent input device providing any arbitrary keyboard or other interactive symbols in addition to computer‐controlled displays. Computer‐aided learning and information retrieval could become an economic reality for people of all ages.
Transplantation of cultured rabbit retinal epithelium to rabbit retina using a closed-eye method. (1987)

We have developed a closed-eye technique for transplanting cultured rabbit retinal epithelial cells to Bruch's membrane of the rabbit. A glass micropipette containing a suspension of 3H-thymidine-labeled, cultured retinal pigment epithelial (RPE) cells is inserted through a pars plana incision and positioned adjacent to the neural retina. A jet stream from the pipette is used to make a small retinal hole and bleb detachment. Patches of host retinal epithelium lift off with the neural retina, creating areas of bare Bruch's membrane. The cell suspension is injected into the subretinal space, and labeled cells can be seen attached to Bruch's membrane as early as 1 hr later. The neural retina spontaneously reattaches within 24 to 48 hr, bringing photoreceptor outer segments in direct contact with the transplanted cells. Phagocytosis of outer segment material by transplanted cells can be seen as early as 24 hr after surgery. This closed-eye technique offers an advantage over the open-sky method used previously in that it allows for reattachment of the neural retina and at least a partial return of function in the transplanted retinal epithelium.
Nonrecursive digital filters for detecting multifrequency code signals (1975)

It is shown that for nonrecursive digital filters in the first canonic form the hardware requirements are proportional to the output rate. Using a low output rate, a relatively simple receiver for multifrequency-code (MFC) signals can be achieved. Linear phase bandpass pairs with a 90° phase difference are used to eliminate the input signal phase dependence. Narrow linear phase bandpass filters with even and odd symmetric impulse response are compared with filters with no phase constraints. It turns out that linear phase filters are almost as good as filters without phase constraints and that 8 bits are enough for the filter coefficients. Some aspects of the design of a digital receiver for PCM-encoded MFC signals are discussed.
Novel synthetic antimicrobial peptides effective against methicillin-resistant Staphylococcus aureus (1994)

Previously, we identified a core undecapeptide of sapecin B having antimicrobial activity. Based on the structure of this peptide, we systematically synthesized peptides consisting of terminal basic motifs and internal oligo-leucine sequences and examined their antimicrobial activities. Of these peptides, RLKLLLLLRLK-NH2 and KLKLLLLLKLK-NH2 were found to have potent microbicidal activity against Staphylococcus aureus, Escherichia coli, methicillin-resistant S. aureus and Candida albicans in liquid medium. We also synthesized the D-enantiomer of KLKLLLLLKLK-NH2. This enantiomer was resistant to tryptic digestion and persisted longer in the culture medium, showing greater antimicrobial activity than the original peptide.
Evaluation of Concealment Techniques for Compressed Digital Audio (1993)

In the context of low bitrate audio coding, particular error concealment techniques can be efficiently applied in order to reduce the effects of errors in the transmission channel. Several proposed methods of varying complexity work on the spectral domain representation of the audio data. The performance of these algorithms is compared in terms of the subjective quality of the restored signal using a perceptual measurement technique.
Non-Markovian gain of strained-layer wurtzite GaN quantum-well lasers with many-body effects (1998)

A theoretical model for the optical gain of strained-layer wurtzite GaN quantum-well (QW) lasers is developed taking into account valence-band mixing, many-body effects and non-Markovian relaxation. The valence-band structure is calculated from a 6/spl times/6 multiband effective mass Hamiltonian for the wurtzite structure taking into account built-in strain due to lattice mismatch. The theoretical foundation for the optical processes is based on the time-convolutionless reduced-density operator formalism given in previous papers for an arbitrary driven system coupled to a stochastic reservoir. Many-body effects are taken into account within the time-dependent Hartree-Fock approximation and the optical gain with Coulomb (or excitonic) enhancement is derived by integrating the equation of motion for the interband polarization. It is predicted that the Coulomb enhancement of gain is pronounced with increasing magnitude of compressive strain in the QW.
Activation of mammalian oocytes by a factor obtained from rabbit sperm (1990)

In this study a fraction was prepared from rabbit sperm that activated rabbit and mouse oocytes following injection into the cytoplasm. The sperm factor activated oocytes exhibited cortical granule exocytosis, pronuclear formation, and cleavage. The sperm factor was soluble in aqueous solution and was not active extracellularly. Unlike most artificial activation methods that are only effective with aged oocytes, the sperm factor activated recently ovulated oocytes. The factor appears to be a protein or associated with a protein but not an acrosomal protein. Fractions from both mouse and bull sperm did not activate rabbit or mouse oocytes. Their inactivity may be owing to the techniques used to recover the fractions or differences between species in sperm morphology and fertilization processes. These observations support the hypothesis that oocyte activation is induced by a factor within sperm that is released into the cytoplasm of the oocyte at the time of sperm-oocyte fusion.
Herpes Simplex Virus Vaccines— Why Don't Antibodies Protect? (1999)

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Use of a Loudness Model for Hearing Aid Fitting. IV. Fitting Hearing Aids with Multi-Channel Compression so as to Restore ‘Normal’ Loudness for Speech at Different Levels (2000)

Many researchers have proposed that multi-channel compression hearing aids should process sounds so as to restore loudness perception to 'normal'. However, procedures for achieving this have generally been based on measurements or calculations using narrowband stimuli, and these procedures may not be accurate for broadband sounds such as speech. Here, a model for predicting loudness for people with cochlear hearing loss is used to calculate the frequency- and level-dependent gains that would be required to restore loudness perception to 'normal' for speech-like signals. The calculations are based entirely on the pure tone audiogram, and do not require measures of loudness growth. The model was applied to several different hypothetical hearing losses, varying in slope and severity. In each case, the model was used to calculate the insertion gains (IGs) that would be required as a function of frequency so that speech-shaped noise with a level of 65 dB SPL would evoke a specific loudness pattern matching that for a normal ear. A similar procedure was applied using speech-shaped noise with a level of 85 dB SPL (with the spectral characteristics of shouted speech). The results were used to derive functions relating the required IG to hearing loss for each audiometric frequency and each speech-shaped noise level. These functions were used in turn to derive compression ratios and gains for each channel of a multi-channel compression system. The derivations apply to systems with any number of channels. The outcome is a method than can be used for the initial fitting of multichannel compression hearing aids, so as to restore loudness perception to near 'normal' for broadband speech-like signals.