gebhart/patrepeval huggingface dataset:
A portable, microprocessor operated instrument for measuring chlorophyll fluorescence kinetics in stress physiology (1988)

A portable instrument for measuring chlorophyll fluorescence induction kinetics is described and examples of measurements are given. The instrument is centered around a statistically‐mixed bifurcated optical fiber. One fiber branch guides the actinic light to the sample, whereas the other branch carries the emitted chlorophyll fluorescence to the photodetector. Scattered actinic light is cut out from the detector by a red interference filter. The instrument measures fast as well as slow fluorescence induction kinetics, but is particularly well designed for analyzing fast kinetics. The high time resolution and strong, variable actinic light mean that both F o (non‐variable fluorescence) and F m (maximal fluorescence at the P‐peak) are well defined. A built in microprocessor unit with attached memory stores the fluorescence induction curve and calculates key fluorescence parameters such as F o , F m , F v (variable fluorescence equals F m −F o ), F v /F m (the photochemical efficiency of photosystem II) and t 1/2 (half rise time from F o , to F m ). These values are digitally displayed after each recording and they (or the whole induction curve) can be stored in a memory and later retrieved. Because of a flexible setting of the instrument it can be used with high accuracy both for optically thick leaves and for diluted suspensions of algae or chloroplasts. A simple, light weight clamp cuvette for dark adaptation of leaves has been developed. It is equipped with a gate allowing the optical fiber to be inserted without daylight reaching the dark adapted portion of the leaf. The instrument has been developed for rapid monitoring of changes in activities and organization of the photosynthetic apparatus in vivo when plants are exposed to environmental stress both in the field and in the laboratory. Examples of measurements are given for differently treated leaves of Pinus sylvestris, Salix sp., Betula verrucosa, Zea mays, Epilobium angustifo‐lium and for chloroplast thylakoids isolated from Spinacia oleracea.
Studies on the Reaction of D-Amino Acid Oxidase with β-Cyano-D-Alanine (1980)

The reaction of D-amino acid oxidase [EC 1.4.3.3] (DAO) from porcine kidney with beta-cyano-D-alanine (D-BCNA) was studied. DAO was found to catalyze elimination of the cyano group as well as oxidation of D-BCNA. During the course of the reaction in the presence of excess oxygen, an intermediate was observed which exhibited a characteristic absorption spectrum with a broad charge transfer band in the longer wavelength region. The CD spectrum of this intermediate resembles that of DAO-anthranilate complex. The rate of oxygen consumption in the aerobic reaction decreased with time, suggesting product inhibition due to complex formation between the enzyme and the product. Anaerobic addition of D-BCNA reduced the enzyme to its fully reduced state, the CD spectrum of which closely resembles that of the enzyme reduced by excess D-alanine. When an appropriate amount of D-BCNA was added to the enzyme under air, the charge transfer complex was observed immediately, and underwent a change to the reduced state as the oxygen was consumed. The binding strength in the charge transfer complex was found to be comparable to that in DAO-benzoate complex. The accumulating product in the oxidation of D-BCNA had a strong absorption at 285 nm. The aerobic reaction of beta-cyano-L-alanine (L-BCNA) with snake venom L-amino acid oxidase (LAO) produced the same product with an absorption at 285 nm as the reaction of DAO with D-BCNA. The product obtained in the reaction with LAO was found to form the same charge transfer complex with DAO. We tentatively identified this product as alpha-amino-beta-cyanoacrylate and the charge transfer complex as the complex of alpha-amino-alpha-cyanoacrylate with the oxidized enzyme. A hypothetical reaction pathway based on the present finding is proposed. Addition of L-BCNA to the enzyme produced an absorption spectrum very similar to that of the DAO-benzoate complex without oxidation or elimination. L-BCNA was found to be a competitive inhibitor of the oxidation of D-alanine.
A comparison of scalar multipole expansions (1984)

Scalar multipole expansions have been widely used in many areas of physics as general solutions to Laplace’s equation. However, comparison of work by different authors is often complicated by the existence of several different forms of multipole expansions in different coordinate systems. In this paper we compare the spherical harmonic, Taylor’s series, direction cosine and traceless tensor expansions and present models of dipole configurations that in the proper limit give the individual multipoles. These pictures simplify the comparison of the series and aid in interpretation of the various multipole moments.
Prohibitins Regulate Membrane Protein Degradation by the <i>m</i> -AAA Protease in Mitochondria (1999)

Prohibitins comprise a protein family in eukaryotic cells with potential roles in senescence and tumor suppression. Phb1p and Phb2p, members of the prohibitin family in Saccharomyces cerevisiae, have been implicated in the regulation of the replicative life span of the cells and in the maintenance of mitochondrial morphology. The functional activities of these proteins, however, have not been elucidated. We demonstrate here that prohibitins regulate the turnover of membrane proteins by the m-AAA protease, a conserved ATP-dependent protease in the inner membrane of mitochondria. The m-AAA protease is composed of the homologous subunits Yta10p (Afg3p) and Yta12p (Rca1p). Deletion of PHB1 or PHB2 impairs growth of Deltayta10 or Deltayta12 cells but does not affect cell growth in the presence of the m-AAA protease. A prohibitin complex with a native molecular mass of approximately 2 MDa containing Phb1p and Phb2p forms a supercomplex with the m-AAA protease. Proteolysis of nonassembled inner membrane proteins by the m-AAA protease is accelerated in mitochondria lacking Phb1p or Phb2p, indicating a negative regulatory effect of prohibitins on m-AAA protease activity. These results functionally link members of two conserved protein families in eukaryotes to the degradation of membrane proteins in mitochondria.
Application Placement Affects Postemergence Smooth Crabgrass (<i>Digitaria ischaemum</i>) and Annual Bluegrass (<i>Poa annua</i>) Control with Indaziflam (2012)

Greenhouse experiments were conducted to determine the effects of herbicide placement on POST smooth crabgrass and annual bluegrass control. Soil-plus-foliar, soil-only, and foliar-only applications of indaziflam (52.5 g ai ha −1 ), dithiopyr (560 ai g ha −1 ), or quinclorac (840 g ai ha −1 ) were made to one-tiller smooth crabgrass plants. Similarly, indaziflam (52.5 g ha −1 ), foramsulfuron (29 g ai ha −1 ), or prodiamine (840 g ai ha −1 ) were applied to nontillering annual bluegrass plants in an identical manner. No differences in smooth crabgrass control were detected between soil-plus-foliar and soil-only applied indaziflam from 21 to 35 d after treatment (DAT). By 28 DAT, smooth crabgrass control and biomass reductions with these indaziflam treatments were ≥ 90% and not different than quinclorac. Comparatively, smooth crabgrass control with foliar-only applications of indaziflam never exceeded 28%. Responses on annual bluegrass were similar as soil-plus-foliar and soil-only applied indaziflam exhibited greater efficacy than indaziflam applied foliar-only. By 28 DAT, annual bluegrass control and aboveground biomass reductions with soil-plus-foliar and soil-only treatments were ≥ 86% and not different from foramsulfuron. Comparatively, foliar-only applications of indaziflam controlled annual bluegrass ≤ 2%. These results indicate that root absorption is required for POST control of smooth crabgrass and annual bluegrass with indaziflam. Further research is needed to determine if techniques to enhance indaziflam contact with soil will enhance POST smooth crabgrass and annual bluegrass control in the field.
ChemInform Abstract: HETEROCYCLIC β‐DIKETOENAMINES. 2. C‐ AND N‐SUBSTITUTED 2‐(4‐PYRIDYL)‐1,3‐INDANEDIONES (1981)

Abstract Die 2‐Pyridyl‐1,3‐indandione (I) liefern die isomeren Formen (II), die in 4′‐Stellung zu (IV) substituiert werden können.
Some Effects of Iron Deficiency on Flowering of Xanthium (1957)

1. Cocklebur plants (Xanthium pensylvanicum Wallr.) exhibiting iron-deficiency symptoms during photoinductive treatment either did not flower subsequently or flowered abnormally when maintained on complete nutrient solution. 2. The abnormal flowering was characterized by (a) the delayed appearance and slower development of terminal staminate inflorescence primordia, (b) the development of pistillate inflorescences, which were surrounded by "rosettes" of many leaves, and (c) the failure of pistillate inflorescences to produce mature burs. 3. Plants which had recovered from iron deficiency and were then subjected to photoinductive treatment flowered normally. 4. A low carbohydrate level in - Fe plants during induction is apparently not responsible for their abnormal flowering, since - Fe plants supplied with 10% sucrose solution during photoinductive treatment also flowered abnormally. The - Fe plants supplied with sucrose soon exhibited more vigorous stem elongation than did - Fe plants not given sucrose, which suggests that the sucrose had been utilized. 5. Aberrant flowering occurred in some photoinduced control plants; this flowering consistently differed from abnormal flowering in - Fe plants with respect to time of appearance of inflorescence primordia, number of aberrant and normal inflorescences per plant, and maturation of burs.
Half-bridge boost rectifier as power factor corrector-electronic balast [balast read ballast] (2002)

A low cost and high power factor electronic ballast is presented in this paper. The proposed topology is based on a single power stage, which integrates the power factor corrector (PFC) and the lamp driver stages. The ballast is obtained by integrating the half bridge boost converter, operating as both rectifier and PFC stage, and the half bridge LC resonant inverter as lamp ballast. The lamp power regulation against line voltage variations is achieved by frequency control. Theoretical analysis and experimental results have been obtained for 26 watts compact fluorescent lamp operating at variable frequency when the input voltage changes from +10% and -15%.
Si single-electron tunneling transistor with nanoscale floating dot stacked on a Coulomb island by self-aligned process (1999)

We studied experimentally and theoretically in detail a Si single-electron tunneling transistor which has a nanoscale floating dot gate stacked on a Coulomb island by a self-aligned process. At 4.2 K, this device exhibits drain current (Id) oscillations due to the Coulomb blockade effect besides the quantized threshold voltage (Vth) shifts with a hysteresis resulting from a single-electron tunneling between the channel and the floating dot gate. The periodicity of the Coulomb oscillation, the voltage separation (ΔVw) between the adjacent two voltages where the Vth shift occurs are consistent with those calculated from the geometrical consideration. The Coulomb oscillation disappeared at room temperature, however, the quantized Vth shifts and hysteresis curves, which are basic operations of single-electron memory, were observed up to room temperature. The fluctuation of electron number in the floating dot was theoretically analyzed at room temperature and we obtained consistent results with the experiments. The high on/off current ratio of the Coulomb oscillation combined with the quantized Vth shifts suggests that it might be possible to produce a memory with ultralow power consumption.
Electron irradiation of field-controlled thyristors (1982)

The influence of 3-MeV electron irradiation upon the characteristics of asymmetrical field-controlled thyristors has been examined for fluences of up to 16 Mrad. In addition to the lifetime reduction due to the radiation damage, carrier removal effects have also been observed in the very lightly doped n-base region of these devices. The leakage current, even after radiation at the highest fluenee, is not significantly increased and the blocking characteristies of these devices are not degraded. In fact, a small improvement in the blocking gain has been observed at low gate voltages. The electron irradiation has been found to increase the forward voltage drop during current conduction and to reduce the forced gate turn-off time. Gate turn-off times of less than 500 ns have been achieved by irradiation with a fluence of 16 Mrad. However, this is accompanied by a large increase in the forward voltage drop. Tradeoff curves between the forward voltage drop and the gate turn-off time have been obtained. From these curves, it has been determined that gate turnoff times of 1 µs can be obtained without a significant increase in the forward voltage drop for devices capable of blocking up to 600 V.
Measurement of mercury methylation in sediments by using enriched stable mercury isotopes combined with methylmercury determination by gas chromatography–inductively coupled plasma mass spectrometry (1995)

A novel technique for the calculation of mercury methylation rates in sediments by using enriched stable mercury isotopes is described. The method takes advantages of the ability of an inductively coupled plasma mass spectrometry (ICP-MS) instrument to measure individual isotopes. An ICP-MS instrument was used as a detector for the determination of methylmercury compounds after separation by gas chromatography (GC). CH3Hg+ was isolated from sediments by distillation, converted to methylethylmercury by sodium tetraethylborate and analysed after purge-and-trap pre-collection on a Tenax adsorber and thermodesorption onto the GC column. Detection limits were found to be ≈ 1 pg (as Hg) absolute or 0.02 ng g–1 dry sediment. The precision was ≈ 4% relative standard deviation when 250 pg of methylmercury were processed. The accuracy of the GC–ICP-MS technique was demonstrated by analysis of an International Atomic Energy Agency certified reference material (IAEA CRM 356) Harbor Sediment, giving a concentration of 5.40 ± 0.40 ng g–1, compared with the certified value of 5.46 ± 0.38 ng g–1. Mercury methylation was investigated by spiking sediments with stable enriched mercury isotopes at in situ mercury concentrations not perturbing the system. More than 3% of the mercury added to a lake sediment was methylated during a 21 d incubation period. Isotope ratios of total mercury differed significantly from isotope ratios of methylmercury at the end of the experiment, suggesting that the system was still not in equilibrium after 21 d.
[Kinetic properties of L-serine dehydratase of the rat liver]. (1989)

Rat liver L-serine dehydratase (E.C.4.2.1.13) catalyzes the deamination both of L-serine and of L-threonine. These reactions show different rates and, at this moment, the "preferential" substrate of the enzyme is not clear. We have analysed, in various experimental conditions, the behaviour of the deaminase reaction toward the two substrates. From the obtained data, it is evident that at lower pH values L-serine and at higher pH values L-threonine, are the preferred substrates, respectively. A peculiar behaviour is shown by Km values, because they are different by changing the pH in the assay mixtures, and changes are related to the presence of pyridoxal-5'-phosphate in the assay mixtures.
Another Unusual Type of Citric Acid Cycle Enzyme in <i>Helicobacter pylori</i> : the Malate:Quinone Oxidoreductase (2000)

The only enzyme of the citric acid cycle for which no open reading frame (ORF) was found in the Helicobacter pylori genome is the NAD-dependent malate dehydrogenase. Here, it is shown that in this organism the oxidation of malate to oxaloacetate is catalyzed by a malate:quinone oxidoreductase (MQO). This flavin adenine dinucleotide-dependent membrane-associated enzyme donates electrons to quinones of the electron transfer chain. Similar to succinate dehydrogenase, it is part of both the electron transfer chain and the citric acid cycle. MQO activity was demonstrated in isolated membranes of H. pylori. The enzyme is encoded by the ORF HP0086, which is shown by the fact that expression of the HP0086 sequence from a plasmid induces high MQO activity in mqo deletion mutants of Escherichia coli or Corynebacterium glutamicum. Furthermore, this plasmid was able to complement the phenotype of the C. glutamicum mqo deletion mutant. Interestingly, the protein predicted to be encoded by this ORF is only distantly related to known or postulated MQO sequences from other bacteria. The presence of an MQO shown here and the previously demonstrated presence of a 2-ketoglutarate:ferredoxin oxidoreductase and a succinyl-coenzyme A (CoA):acetoacetyl-CoA transferase indicate that H. pylori possesses a complete citric acid cycle, but one which deviates from the standard textbook example in three steps.
Dense Methods for Image Alignment with an Application to 3D Tracking (2014)

This survey focuses on a class of methods for image alignment based on a global, iterative optimization. We synthetically describe the existing methods (included the recent Efficient Second Order Method), compare their theoretical aspects, computational costs and implementation issues, and finally present an example of application to 3D tracking, involving a complex, non-linear warp.
Reflectance difference spectroscopy spectra of clean (3×2), (2×1), and c(2×2) 3C-SiC(001) surfaces: New evidence for surface state contributions to optical anisotropy spectra (1998)

In this study we applied the surface sensitive optical method reflectance difference spectroscopy to investigate the optical response of clean cubic 3C-SiC(001) surfaces. The main reconstructions, the Si-rich (3×2) and (2×1) as well as the C-rich c(2×2) were prepared by annealing in Si flux. For (3×2) we find a strong spectral feature at 4.2 eV that is not observed for the other two reconstructions. Since the direct gap of 3C-SiC is at higher photon energies the 4.2 eV feature must be related to the surface. Angle resolved ultraviolet photoelectron spectroscopy measurements indicate surface states around the X̄ point of the unreconstructed surface Brillouin zone. We conclude that the 4.2 eV feature is associated with this surface state and suggest that it is linked to the E2 gap of bulk Si at 4.2 eV.
Basic Transport Phenomena in Biomedical Engineering (2011)

Encompassing a variety of engineering disciplines and life sciences, the very scope and breadth of biomedical engineering presents challenges to creating a concise, entry level text that effectively introduces basic concepts without getting overly specialized in subject matter or rarified in language. Basic Transport Phenomena in Biomedical Enginee
Indaziflam Herbicidal Action: A Potent Cellulose Biosynthesis Inhibitor    (2014)

Cellulose biosynthesis is a common feature of land plants. Therefore, cellulose biosynthesis inhibitors (CBIs) have a potentially broad-acting herbicidal mode of action and are also useful tools in decoding fundamental aspects of cellulose biosynthesis. Here, we characterize the herbicide indaziflam as a CBI and provide insight into its inhibitory mechanism. Indaziflam-treated seedlings exhibited the CBI-like symptomologies of radial swelling and ectopic lignification. Furthermore, indaziflam inhibited the production of cellulose within <1 h of treatment and in a dose-dependent manner. Unlike the CBI isoxaben, indaziflam had strong CBI activity in both a monocotylonous plant (Poa annua) and a dicotyledonous plant (Arabidopsis [Arabidopsis thaliana]). Arabidopsis mutants resistant to known CBIs isoxaben or quinoxyphen were not cross resistant to indaziflam, suggesting a different molecular target for indaziflam. To explore this further, we monitored the distribution and mobility of fluorescently labeled CELLULOSE SYNTHASE A (CESA) proteins in living cells of Arabidopsis during indaziflam exposure. Indaziflam caused a reduction in the velocity of YELLOW FLUORESCENT PROTEIN:CESA6 particles at the plasma membrane focal plane compared with controls. Microtubule morphology and motility were not altered after indaziflam treatment. In the hypocotyl expansion zone, indaziflam caused an atypical increase in the density of plasma membrane-localized CESA particles. Interestingly, this was accompanied by a cellulose synthase interacting1-independent reduction in the normal coincidence rate between microtubules and CESA particles. As a CBI, for which there is little evidence of evolved weed resistance, indaziflam represents an important addition to the action mechanisms available for weed management.
Thiadiazoles and thiadiazolines. Part 4. Acetylation, hydrolysis, and cyclocondensations of Δ<sup>2</sup>-1,3,4-thiadiazoline-α-carboxamidines (1982)

The thiadiazolinecarboxamidine (1a) forms a stable acetate in glacial acetic acid but is diacetylated to give the thiadiazoline (3) using acetic anhydride and mineral acid. Similar treatment of (1c) and (1d) gives, at 60 °C or below, the monoacetyl derivatives (10) and (6) respectively. The acetylthiadiazolinecarboxamidine (6) decomposes at 60–140 °C yielding the 4-acetylthiadiazoline (7), which may also be obtained by acetylation of an oil produced by basic hydrolysis of (1a). Neutral hydrolysis in aqueous methanol converts (1a) and (1b) into the carbamoylthiadiazoline (11); the trimethylthiadiazolinecarboxamidine (1e) into the N-methylcarbamoylthiadiazoline (12), and the diacetylthiadiazolinecarboxamidine (3) into the N-acetylcarbamoylthiadiazoline (5). The thiadiazolinecarboxamidine (1a) reacts with 1,3-dicarbonyl compounds to give 4-pyrimidin-2-ylthiadiazolines (15)–(17), and decomposes in refluxing mesitylene to give, amongst other products, trans-stilbene and 2,5-diphenyl-1,3,4-thiadiazole.
Partial suppression of Theiler's virus‐induced demyelination in vivo by administration of monoclonal antibodies to immune‐response gene products (Ia antigens) (1986)

In vivo administration of monoclonal antibody reactive with major histocompatibility complex-encoded Ia molecules (I-As) partially suppressed inflammation and demyelination in the spinal cord of SJL/J (H-2s) mice persistently infected with Theiler's murine encephalomyelitis virus. Demyelination was decreased if antibody was given at the time of virus inoculation or after inflammation had been established in the spinal cord. The decrease in demyelination was independent of isolation of infectious virus from the CNS or of serum titers of immunoglobulin to purified viral antigen. Thus, Theiler's virus-induced demyelination is mediated, in part, by immune cells that carry Ia class II molecules.