cssi/SciSciGPT-SciSciNet huggingface dataset:
Generating hierarchical document indices from common denominators in large document collections

Abstract This paper describes an effective, simple and efficient algorithm for computer generation of hierarchical indices from Document-Term matrices by means of calculating common denominator vectors from the document vector set. This procedure produces an intuitive, user-friendly hierarchical index of a document collection not unlike that which would be expected had a manual indexer set about to create an index or outline of a collection. The resulting index, when presented with a graphical user interface, provides the user with a natural easily comprehended view of the document collection that permits general browsing and informal search activities with an access method that requires no keyboard entry or prior knowledge of the vocabulary.
Allosteric Binding Site and Activation Mechanism of Class C G-Protein Coupled Receptors: Metabotropic Glutamate Receptor Family.

Metabotropic glutamate receptors (mGluR) are mainly expressed in the central nervous system (CNS) and contain eight receptor subtypes, named mGluR1 to mGluR8. The crystal structures of mGluR1 and mGluR5 that are bound with the negative allosteric modulator (NAM) were reported recently. These structures provide a basic model for all class C of G-protein coupled receptors (GPCRs) and may aid in the design of new allosteric modulators for the treatment of CNS disorders. However, these structures are only combined with NAMs in the previous reports. The conformations that are bound with positive allosteric modulator (PAM) or agonist of mGluR1/5 remain unknown. Moreover, the structural information of the other six mGluRs and the comparisons of the mGluRs family have not been explored in terms of their binding pockets, the binding modes of different compounds, and important binding residues. With these crystal structures as the starting point, we built 3D structural models for six mGluRs by using homology modeling and molecular dynamics (MD) simulations. We systematically compared their allosteric binding sites/pockets, the important residues, and the selective residues by using a series of comparable dockings with both the NAM and the PAM. Our results show that several residues played important roles for the receptors’ selectivity. The observations of detailed interactions between compounds and their correspondent receptors are congruent with the specificity and potency of derivatives or compounds bioassayed in vitro. We then carried out 100 ns MD simulations of mGluR5 (residue 26-832, formed by Venus Flytrap domain, a so-called cysteine-rich domain, and 7 trans-membrane domains) bound with antagonist/NAM and with agonist/PAM. Our results show that both the NAM and the PAM seemed stable in class C GPCRs during the MD. However, the movements of “ionic lock,” of trans-membrane domains, and of some activation-related residues in 7 trans-membrane domains of mGluR5 were congruent with the findings in class A GPCRs. Finally, we selected nine representative bound structures to perform 30 ns MD simulations for validating the stabilities of interactions, respectively. All these bound structures kept stable during the MD simulations, indicating that the binding poses in this present work are reasonable. We provided new insight into better understanding of the structural and functional roles of the mGluRs family and facilitated the future structure-based design of novel ligands of mGluRs family with therapeutic potential.
Extracellular S‐nitrosoglutathione, but not S‐nitrosocysteine or N2O3, mediates protein S‐nitrosation in rat spinal cord slices*

There is evidence that protein S-nitrosothiols (PrSNOs) accumulate in inflammatory demyelinating disorders like multiple sclerosis and experimental allergic encephalomyelitis. However, very little is known regarding the mechanism by which PrSNOs are formed in target cells. The present study compares the ability of potential intercellular mediators of nitrosative damage including S-nitrosoglutathione (GSNO), S-nitrosocysteine and N(2)O(3) to induce protein S-nitros(yl)ation in the spinal cord, a CNS region that is commonly affected in multiple sclerosis and experimental allergic encephalomyelitis. The results clearly demonstrate that while all three NO-donors cause S-nitrosation of proteins in cell-free systems, only GSNO is a viable S-nitrosating agent in rat spinal cord slices. Generation of PrSNOs with GSNO occurs by S-transnitrosation as the process was not inhibited by either the NO-scavenger rutin or the N(2)O(3)-scavenger azide. Contrary to other cell types, nerve cells incorporate intact GSNO and neither functional l-amino acid transporters nor cell-surface thiols are required. We also found that there is a restricted number of proteins available for S-nitrosation, even at high, non-physiological concentrations of GSNO. These proteins are highly concentrated in mitochondria and mitochondria-rich subcellular compartments. This study is relevant to those CNS disorders characterized by excessive nitric oxide production.
Efficacy of suramin against human prostate carcinoma DU145 xenografts in nude mice.

Purpose: Toward developing a model to study the mechanism of action of suramin against prostate cancer, we identified the effect of suramin on the growth of xenografts of the androgen-independent human prostate carcinoma DU145 cell line and our subline of suramin-resistant (SR) DU145 cells which are less responsive to suramin in vitro. Methods: Athymic nude mice bearing DU145 or SR DU145 xenografts were treated intraperitoneally (IP) once weekly with normal saline (vehicle control) or suramin in normal saline. For data analysis mice were grouped as follows: 0 mg/kg (controls), <210 mg/kg, 210 to 260 mg/kg, or gt;260 mg/kg suramin. Results: The growth of DU145 xenografts was slowed by treatment with 210 to 260 mg/kg suramin IP once weekly: differences in tumor volume for the 210 to 260 mg/kg group compared with the control group on days 29 and 57 showed growth inhibited by 43% and 55%, respectively. At the same time, growth of SR DU145 xenografts generally was not slowed by suramin treatment at any dose, but appeared to be enhanced to some degree by all doses of suramin during the typical slower initial growth phase of xenografts of this cell line: differences in tumor volume compared with control on day 29 showed growth enhanced by 100% to 342%. Mice treated with 210 to 260 mg/kg maintained nadir suramin plasma levels near our clinically relevant target of 1 × 10−4 M. Conclusions: Suramin, without concomitant corticosteroid therapy, was effective in slowing the growth of DU145 xenografts in nude mice at clinically relevant plasma suramin levels. The data showing efficacy for DU145 xenografts was supported by the lack of efficacy at the same time for xenografts of cells known to be less responsive to suramin in vitro, i.e. the SR DU145 cells, at similar doses and nadir plasma suramin levels. In discussions on the utility of suramin our data should be considered as support for continuing the study of suramin in the treatment of advanced, androgen-independent prostate cancer.
Knowledge-based characterization of similarity relationships in the human protein-tyrosine phosphatase family for rational inhibitor design

Tyrosine phosphorylation, controlled by the coordinated action of protein-tyrosine kinases (PTKs) and protein-tyrosine phosphatases (PTPs), is a fundamental regulatory mechanism of numerous physiological processes. PTPs are implicated in a number of human diseases and their potential as prospective drug targets is increasingly being recognized. Despite their biological importance, until now no comprehensive overview has been reported describing how all members of the human PTP family are related. Here we review the entire human PTP family and present a systematic knowledge-based characterization of global and local similarity relationships, which are relevant for the development of small molecule inhibitors. We use parallel homology modeling to expand the current PTP structure space and analyze the human PTPs based on local three-dimensional catalytic sites and domain sequences. Furthermore, we demonstrate the importance of binding site similarities in understanding cross-reactivity and inhibitor selectivity in the design of small molecule inhibitors.
Effects of the positively regulating product of gene 28 of the B. subtilis phage SPO1 on in vitro transcription.

Some of the properties of the RNA polymerase purified from SPO1-infected Bacillus subtilis have been compared with the properties of RNA polymerase from uninfected cells (core+δ). The two enzymes synthetize RNA from nonoverlapping regions on SPO1 DNA, and they lead to the retention of different restriction fragments of SPO1 DNA on cellulosenitrate filters.
Ontogeny of polycose and sucrose appetite in neonatal rats.

Rat pups 3 to 15 days of age were infused with sucrose or Polycose solutions (.03 or .3 M) through oral cannulas and their solution intake, mouthing behavior, and general locomotor activity were recorded. Overall, the pups displayed similar ingestive responses to Polycose and sucrose. They discriminated between .3 M sucrose and water as early as 6-days of age, and between .3 M Polycose and water as early as 9-days of age. However, at the .03 M concentration the pups responded to Polycose before they responded to sucrose. The results confirm previous reports that rat pups have an unlearned preference for sucrose and demonstrate that a similar preference exists for starch-derived polysaccharides. The Polycose appetite displayed by the neonatal rats is consistent with results obtained with adult animals which suggest that rats have taste receptors for starch-derived polysaccharides as well as for sugars.
Comparative chlorine requirements of different plant species

Recognition of chlorine as a plant micronutrient has been extended to include ten species. Acute chlorine deficiencies or decreased yields were produced with lettuce, tomato, cabbage, carrot, sugar beet, barley, alfalfa, buckwheat, corn, and beans. Squash plants showed neither loss in yield nor other deficiency symptoms when cultured at the same time and under the same conditions as the aforementioned species. All plants acquired more chlorine during their growth than can be accounted for from seeds, inorganic salts, or water used in the experiments. Plant species least susceptible to injury when cultured upon low chlorine salt solutions were also the ones most capable of acquiring extrinsic chlorine. Of the species studied, lettuce was the most sensitive to “minus chlorine” culture solutions and squash, the least sensitive. However, the concentration of chlorine in all of the species cultured under limited chlorine supply was not greatly different. It is inferred that plants such as corn, beans, and squash survived the “minus chlorine” cultures by reason of greater accretion of extrinsic chlorine from the atmosphere. The form of the atmospherically borne chlorine is not known.
Experiments on Control of the Northern Fowl Mite

These experiments were conducted to determine the most effective and practical methods for fowl mite control under modern poultry husbandry practices. Ronnel, Sevin® (1-naphthyl N-methylearbamate), and Co-ral®( O, O -diethyl O -3-chloro-4-methyl-2-oxo- 2ll -1-benzopyran-7-yl phosphorothioate) proved most effective, in that order, for control of the northern fowl mite on chickens.
Modeling the Residual Market Value of Construction Equipment under Changed Economic Conditions

This paper reapplies a statistical model that was created prior to 2003 to forecast the residual value of used heavy construction equipment in the United States. The objective is to evaluate the pe...
Divalent Cations Increase Lipid Order in Erythrocytes and Susceptibility to Secretory Phospholipase A2

Elevated concentrations of intracellular calcium in erythrocytes increase membrane order and susceptibility to secretory phospholipase A2. We hypothesize that calcium aids the formation of domains of ordered lipids within erythrocyte membranes by interacting directly with the inner leaflet of the cell membrane. The interface of these domains with regions of more fluid lipids may create an environment with weakened neighbor-neighbor interactions that would facilitate phospholipid migration into the active site of bound secretory phospholipase A2. This hypothesis was investigated by determining the effects of seven other divalent ions on erythrocyte membrane properties. Changes in membrane order were assessed with steady-state fluorescence spectroscopy and two-photon microscopy with an environment-sensitive probe, laurdan. Each ion increased apparent membrane order in model membranes and in erythrocytes when introduced with an ionophore, suggesting that direct binding to the inner face of the membrane accounts for the effects of calcium on membrane fluidity. Furthermore, the degree to which ions affected membrane properties correlated with the ionic radius and electronegativity of the ions. Lastly, erythrocytes became more susceptible to enzyme hydrolysis in the presence of elevated intracellular levels of nickel and manganese, but not magnesium. These differences appeared related to the ability of the ions to induce a transition in erythrocyte shape.
Assessment of early pulmonary function abnormalities in giant omphalocele survivors

Abstract Purpose Infants with giant omphalocele (GO) are at increased risk for persistent respiratory insufficiency, yet information regarding the systematic assessment of their lung function is limited. We performed a group of pulmonary function tests (PFTs) including spirometry, fractional lung volume measurements, assessment of bronchodilator responsiveness, and passive respiratory mechanics in GO survivors during infancy and early childhood to evaluate the nature and degree of pulmonary dysfunction. Material and Methods Between July 2004 and June 2008, 30 consecutive GO survivors were enrolled in our interdisciplinary follow-up program. Forty-seven percent (14/30) underwent PFT during follow-up evaluation using the raised volume rapid thoracic compression technique to measure forced expiratory flows and bronchodilator responsiveness, body plethysmography to calculate lung volumes, and the single breath occlusion technique to measure passive mechanics of the respiratory system. Results The mean age at PFT assessment was 19.3 ± 19.7 months (range, 1.0-58). Mean forced vital capacity and mean forced expiratory volume in the first 0.5 second were significantly reduced compared with published normative values ( P = .03 and P P P = .21, P = .34, and P = .48, respectively). Among the 46% who demonstrated significant bronchodilator responsiveness, there were greater increases in the mean percentage changes in flow at 25% to 75% ( P = .01), flow at 75% ( P P Conclusions Abnormalities of pulmonary function in GO survivors include lung volume restriction without airway obstruction, an increased likelihood of airway hyperresponsivness, and reduced respiratory system specific compliance. Early recognition of pulmonary functional impairment in GO survivors could help to develop targeted treatment strategies to reduce the risk of subsequent pulmonary morbidity.
Duration of the cycle of the seminiferous epithelium in the prairie vole (Microtus ochrogaster ochrogaster).

The cycle of the seminiferous epithelium in M. o. ochrogaster was divided into eight readily recognizable stages based on the morphology of the developing spermatid. The mean relative frequencies of Stages I through VIII were 11.66, 19.25, 20.00, 19.00, 8.42, 6.17, 9.25 and 6.58%, respectively. The duration of one cycle of the seminiferous epithelium in this species, as determined from autoradiographs of thymidine-H3 injected testes was 7.17 days (S.E. ± 0.03). This is the shortest spermatogenic cycle reported for any mammal to date. The approximate durations of the meiotic prophase, meiotic divisions, and spermiogenesis were 8.8, 0.4 and 12.2 days, respectively. The entire process of spermatogenesis was estimated to span approximately 28.68 days. The number of cycles that spermiogenesis spanned in this species was compared to values calculated for other species. Values within groups of related species appear relatively constant, but between groups the values are variable.
The Parallel Type Inverter

The parallel type inverter is one of many forms which are undergoing development at the present time. It gives promise of becoming of considerable importance and therefore the principles of operation should be better and more widely known. The object of this paper is to make a qualitative analysis of the operation of this type under different conditions of loading, and to present the results largely in the form of complete sets of oscillograms for further study. Inverters of the types now being studied involve the use of hot-cathode mercury-vapor tubes called thyratrons. The characteristics of these tubes are given briefly and the data necessary for an understanding of their operation in these circuits are presented. The principle of operation of the inverter circuit is developed by means of simple diagrams and then the actual conditions throughout the circuit are studied by means of oscillograms showing the voltages and currents in all of the essential parts. It is shown that the method of operation may be considered in a different manner from that usually assumed in the development of the circuit, inasmuch as the capacitor can be thought of as performing the function of giving the correct phase relation between the input current and the induced transformer primary voltage, rather than providing a sudden reversal of potential on the anode of the tube being stopped. This reversal is provided by the induced primary voltage. The current conditions for the various steps of operation are shown by simple diagrams.
How Census 2000 Data Suggest Hostility Toward Mexican-Origin Arizonians

Abstract Using the Arizona 5% Public Use Microdata Sample (PUMS) from the 2000 U.S. Census, we compare language-related figures for the Mexican-origin population with those for the total population. Additionally, we compare place of birth and educational attainment data for Mexican-origin persons who speak Spanish at home with those who speak English-only to provide a fuller characterization of these groupings. The 5% PUMS files contain individual records of responses to census questionnaires representing a 5% sample of the occupied and vacant housing units in Arizona and the persons in the occupied units. Our purpose is to more fully characterize the Arizona population to assist in improving education, language, and legal policy in the state, and we conclude that current legal, language, and education initiatives, such as efforts to impose an official English language and to restrict native languages in schools, are at odds with population figures and may signal hostility toward Mexican-origin Arizonians.
Central neurophysiological correlates of constant light-induced retinal degeneration.

Abstract Single-unit electrophysiological experiments were conducted on albino rats housed in either cyclic light or constant light for as long as 24 weeks. Histological examination of the retinas of the constant light-exposed rats confirmed that there was a massive degeneration of the photoreceptor cells. Despite this degeneration, visually responsive cells were found in the lateral geniculate nucleus (LGN) and the visual cortex (VC) at all exposure times. With increasing exposure times, we found that cells in the LGN and VC had longer response latencies and less vigorous responses and that it was necessary to illuminate larger areas of the visual field in order to produce responses. Studies of LGN cells in control and experimental rats showed that the spectral sensitivities of those cells were similar in shape and peak sensitivity to the spectral absorption properties of rhodopsin. In view of this fact, it seems most likely that rhodopsin is the primary light-transducing molecule in the retina of rats exposed to long-term constant light. The spectral sensitivity curves of some cells in control animals and light-exposed animals had minor peaks at 600 nm, which may have been due to some additional visual pigment molecule.
Investigation of the Complex Flow Behaviour of Surfactant-Based Fluids in Straight Tubing

In spite of their wide use in hydraulic fracturing and gravel-pack operations, the complex flow behaviour of surfactant-based (SB) fluids in straight tubing is rarely investigated. Accurate prediction of friction-pressure is essential for proper treatment design. Previous correlations from small tubing data and using simple power-law fluid model parameters alone do not scale up to large tubing sizes for field application. The properties of one of the most popular surfactants, Aromox APA-T, are thoroughly investigated. It is a highly active surfactant used as the gelling agent in aqueous and brine solutions. Commonly used surfactant concentrations (1.5%, 2%, 3% and 4% by volume) are studied. Rheological and viscoelastic measurements are conducted using the Bohlin rheometer. Flow tests are conducted using 1.27-cm, 3.81-cm, 6.03-cm and 7.30-cm tubing. The results show SB fluid exhibiting a non-Newtonian pseudo-plastic behaviour. Fluid concentration and pipe shear have a significant effect on fluid elasticity. The conventional Fanning friction factor vs. Reynolds number correlation is improved by including a new dimensionless group that accounts for both fluid elasticity and pipe diameter. A new definition of Deborah number is introduced. Thus, a new correlation for predicting friction factors of SB fluid in straight tubing is developed. The scaleup problem is thus alleviated with the present analysis and this provides more accurate friction-pressure estimates.
Pauling’s Defence of Bent-Equivalent Bonds: A View of Evolving Explanatory Demands in Modern Chemistry

Summary Linus Pauling played a key role in creating valence-bond theory, one of two competing theories of the chemical bond that appeared in the first half of the 20th century. While the chemical community preferred his theory over molecular-orbital theory for a number of years, valence-bond theory began to fall into disuse during the 1950s. This shift in the chemical community's perception of Pauling's theory motivated Pauling to defend the theory, and he did so in a peculiar way. Rather than publishing a defence of the full theory in leading journals of the day, Pauling published a defence of a particular model of the double bond predicted by the theory in a revised edition of his famous textbook, The Nature of the Chemical Bond. This paper explores that peculiar choice by considering both the circumstances that brought about the defence and the mathematical apparatus Pauling employed, using new discoveries from the Ava Helen and Linus Pauling Papers archive.
Librarianship and Information Science in Islamic East Africa 1966–1999: An Annotated Bibliography

This work is an annotated bibliography that consists of articles, books, conference papers, dissertations, and reports, etc. published in various library and information science forums on the subject of librarianship in Islamic East Africa. The goal of preparing this work is to provide a list of citations with abstracts that librarians, library students, and library scholars can use to perform research within this subject area and further the body of knowledge. The research methodology that was used to find these citations involved searching the database versions of ERIC, Dissertations Abstracts Online, and Library Literature within the online public access catalog of the Auburn University library system. It also involved searching the online databases of Library and Information Science Abstracts (LISA), British Education Index, and Education Abstracts within the DIALOG database as well as the respective print copies of these resources. While this work is by no means an exhaustive analysis of the entire East African library literature, it does strive to be comprehensive in terms of its country-by-country breakdown of librarianship within the region. Islamic East Africa for the purposes of this work incorporates the nations of Comoros, Djibouti, Eritrea, Ethiopia, Somalia, Sudan, and Tanzania. In providing a citation for a non-English language work, the English equivalent of the title of that work will be given next to the non-English title.
Analyses of excess molar volumes of the acetonitrile-water system using segmented composition models

Abstract A segmented composition model has been used to analyse a number of sets of values of the excess molar volumes of the acetonitrile-water system, covering fairly wide ranges of temperature and pressure. The assumption of the existence of reasonably discrete composition segments for a binary mixture introduces hypothetical standard states of its components. The properties of those hypothetical states have been explored and some conclusions made about the possible patterns of molecular aggregation.
Changes in protein solubility and gelation properties of chicken myofibrils during storage.

The effect of storage on protein solubility and heat-induced gelation properties of chicken hen breast and leg myofibrils was investigated. Myofibrils suspended in 0.6M NaCl, pH 6.0, showed increasing protein solubility, viscosity, gel strength and water holding capacity with storage at 4°C. However, the effect of storage was most dramatic only during the initial 10 hr for all of the parameters studied. The relative distribution of the proteins comprising the salt soluble protein (SSP) extract changed during storage. Although storage had little effect on breast SSP, it was detrimental to leg SSP gelation. Breast myofibril suspensions, for all storage times, contained a greater amount of SSP and had better gelation properties than leg myofibril suspensions.
Integration of a gene marker into mouse mammary glands during whole organ culture

The objective of this study was to develop a method to indelibly mark mammary cells to follow cell lineage. This was done by infecting mouse mammary glands in whole organ culture (WOC) with a retroviral vector containing the β-galactosidase (BAG) gene. Abdominal mammary glands from BALB/c mice primed with estrogen and progesterone were removed and injected with 30 µl of concentrated vector prepared from CRE BAG 2 (ATCC 1858 — CRL) cells or left uninjected and co-cultured with CRE BAG 2 feeder layers for 48 or 96 hours. Glands were floated on siliconized lens paper and incubated in Waymouth's 752/1 medium supplemented with insulin, aldosterone, hydrocortisone, prolactin, and epidermal growth factor for 5 days. Integration of BAG was determined with a colorimetric assay using X-gal, a β-galactoside analog, in whole mounts and collagenase digested glands. Blue cells in collagenase digests and blue areas in whole mounts indicated that BAG had integrated into mammary cells during whole organ culture.
Solid-phase synthesis of novel isoxazolocyclobutanones and isoxazolinocyclobutenones.

The preparation of novel isoxazolocyclobutanone and isoxazolinocyclobutenone derivatives via a traceless solid-phase sulfone linker strategy is described. Key steps in the solid-phase protocol reported here include (i) sulfinate → sulfone alkylation, (ii) four-member ring formation by sulfone dianion alkylation, (iii) heterocycle formation by nitrile oxide 1,3-dipolar cycloaddition, and (iv) traceless product release by cyclobutanol → cyclobutanone oxidation with concomitant linker cleavage by sulfinate elimination.
An interpretation of the optical properties of Cr4+-activated pyrochlores, Y2Ti2O7 and Y2Sn2O7

Abstract A qualitative model is proposed to explain the differences between the optical properties of the six-coordinated Cr4+ ion in the pyrochlores, Y2Sn2O7 and Y2Ti2O7. It is shown that polarization of the electron density of the oxygen ions occupying the 48f sites of the pyrochlore lattice is responsible for the observed differences in the optical properties.
An IEEE 802.11 DCF-based optimal data link layer spectrum sensing scheme in cognitive radio networks

In cognitive radio networks (CRNs), spectrum sensing is the key functionality for unlicensed users to detect the unused spectrum. Currently, almost all the spectrum sensing schemes for CRNs are implemented at the physical layer. However, one serious problem with current physical layer spectrum sensing is that it can only detect the presence of licensed user signals but it cannot distinguish between the licensed transmitter and the licensed receiver. This may lead to spectrum sensing inaccuracies that cause interference at the licensed receiver or a waste of spectrum resources for unlicensed users. These issues make physical layer spectrum sensing inadequate in certain practical scenarios. In this paper, a novel data link layer spectrum sensing scheme based on the IEEE 802.11 DCF is proposed to improve the spectrum sensing accuracy. Moreover, an optimal spectrum sensing duration is derived to balance the trade-off between the spectrum sensing accuracy and the spectrum sensing overhead. Simulation results show that the proposed data link layer spectrum sensing scheme outperforms the physical layer sensing scheme in terms of lower collision probability between the licensed and unlicensed transmissions. To the best of our knowledge, this is the first work that investigates the data link layer spectrum sensing in CRNs.
Marital Transitions, Parenting, and Schooling: Exploring the Link Between Family-Structure History and Adolescents' Academic Status:

The linkage between family structure and adolescents' academic experiences is part of a larger, dynamic process unfolding over time. To investigate this phenomenon, this study drew on the National Longitudinal Study of Adolescent Health and the Adolescent Health and Academic Achievement Study. Logistic regressions revealed that family structure at birth predicted students' academic status in math in the ninth grade, and multinomial regressions revealed that family instability, along with curricular location in the ninth grade, parenting behaviors, and adolescents' adjustment and aspirations, distinguished those who completed higher-level math by the end of high school from those who did not but still graduated from high school and from those who dropped out of high school.
Superoxide formation by protoporphyrin as seen by spin trapping.

The cutaneous photosensitivity of individuals with erythropoietic protoporphyria has been associated with the abnormally large amounts of protoporphyrin, found in the red blood cells [ 11. Patients with erythropoietic protoporphyria are sensitive to radiation near 400 nm which corresponds with the absorption maxima of protoporphyrin [2]. The photochemical damage is thought to be the result of light absorption by the porphyrins in the skin or superficial dermal vasculature. There is still much unknown about the molecular mechanism that produces the damage. Because P-carotene ameliorates many of the symptoms, singlet oxygen has been proposed as the causative agent [2]. Moreover, a characteristic singlet oxygen product of cholesterol has been observed [3] when red blood cell ghosts are irradiated in the presence of protoporphyrin. The formation of malonaldehyde, an indicator of lipid peroxidation, with the photohemolysis of erythropoietic protoporphyric red cells has been observed [4]. However, it was observed [5,6] that only negligible amounts of malonaldehyde or the cholesterol derivative are produced during irradiation prior to leakage of hemoglobin from the red cells. Photooxidation of amino acids and photoaggregation with evidence of crosslinking of membrane polypeptides has been noted [5,7], suggesting a free radical mechanism. Thus, the question of whether a singlet oxygen or a free radical mechanism is involved in the photodamage is still unsettled. We have observed the light-induced generation of superoxide by protoporphyrin using the technique of spin trapping. The superoxide spin adduct of
Differential Calcineurin/NFATc3 Activity Contributes to the Ito Transmural Gradient in the Mouse Heart

Kv4 channels are differentially expressed across the mouse left ventricular free wall. Accordingly, the transient outward K+ current ( I to), which is produced by Kv4 channels, is greater in left ventricular epicardial (EPI) than in endocardial (ENDO) cells. However, the mechanisms underlying heterogeneous Kv4 expression in the heart are unclear. Here, we tested the hypothesis that differential [Ca2+]i and calcineurin/NFATc3 signaling in EPI and ENDO cells contributes to the gradient of I to function in the mouse left ventricle. In support of this hypothesis, we found that [Ca2+]i, calcineurin, and NFAT activity were greater in ENDO than in EPI myocytes. However, the amplitude of I to was the same in ENDO and EPI cells when [Ca2+]i, calcineurin, and NFAT activity were equalized. Consistent with this, we observed complete loss of I to and Kv4 heterogeneity in NFATc3-null mice. Interestingly, Kv4.3, Kv4.2, and KChIP2 genes had different apparent thresholds for NFATc3-dependent suppression and were ordered as Kv4.3≈KChIP2>Kv4.2. Based on these data, we conclude that calcineurin and NFATc3 constitute a Ca2+-driven signaling module that contributes to the nonuniform distribution of Kv4 expression, and hence I to function, in the mouse left ventricle.
Memory for spatial locations, motor responses, and objects : triple dissociation among the hippocampus, caudate nucleus, and extrastriate visual cortex

Based on behavioral procedures aimed at measuring working or data-based memory for spatial location, response, and visual object information, it is shown that there is a triple dissociation among the hippocampus, caudate nucleus, and extrastriate visual cortex in mediating spatial location, response, and visual object information, respectively. The hippocampus appears to subserve only spatial location, the caudate nucleus only response, and the extrastriate visual cortex only visual object information. The results support the neurobiological foundation of the attribute memory model.
Expanding indications for the use of thrombolytic agents in acute myocardial infarction.

A large body of data from randomized clinical trials have definitely established that thrombolytic therapy in acute myocardial infarction reduces the risk of early mortality by approximately one fourth. Unfortunately, most (but not all) trials have been unduly restrictive in selecting patients who have been entered. Consequently, at least half of the patients (many of whom are at high risk of death) who present with signs and symptoms of acute myocardial infarction are not considered for such therapy. A critical analysis of the data from all the available trials indicates that thrombolytic therapy reduces mortality in a much broader group of patients than generally believed. For example, patients who present late (i. e., 6–24 h) after the onset of symptoms, those over the age of 75 years, those with classical symptoms but minor or no abnormalities on the first electrocardiogram, those with low or high blood pressure, and patients in several other subgroups have been shown to benefit. The absolute and relative risk of major adverse effects (such as major bleeding episodes or strokes) have been so low that in each of these subgroups the benefits of treatment far outweigh their potential risks.
Hyperfibrinolytic activity in hospitalized cirrhotic patients in a referral liver unit.

Abstract OBJECTIVE: Increased frequency of hyperfibrinolytic activity was reported in patients with cirrhosis. However, the incidence, clinical presentation, and the parameters related to hyperfibrinolysis remain largely unknown in these patients. By utilizing euglobulin lysis time (ELT) and other clinical coagulation tests, the present study investigated the incidence of and clinical parameters related to hyperfibrinolytic activity, and assessed predicting factors to e-aminocaproic acid (EACA) treatment in cirrhotic patients with hyperfibrinolysis in a liver unit. METHODS: The study included 86 consecutive patients who were referred and admitted to a referral liver unit for various liver diseases. The mean age was 50.0 yr, with a male:female ratio of 60:26. Sixty-six patients (76.7%) were Hispanic and 75 (87.2%) were cirrhotic. The etiologies of liver diseases included alcoholic liver disease (n = 68, 79.1%), hepatitis B (n = 2, 2.3%), hepatitis C (n = 6, 7.0%), autoimmune hepatitis (n = 3, 3.5%), cryptogenic liver disease (n = 4, 4.7%), and hepatocellular carcinoma (n = 3, 3.5%). Coagulation studies included ELT, PT, PTT, fibrinogen, D-dimer, and fibrin degradation product levels. RESULTS: Hyperfibrinolytic activity as reflected by shortened ELT was present in 27/75 cirrhotic (31.3%) but 0/11 noncirrhotic patients, which was significantly correlated with higher Child-Pugh (C-P) class, abnormal levels of PT, PTT, fibrinogen, platelet count, and total bilirubin. Shortened ELT was more frequently seen in patients with hepatic decompensation and mucocutaneous bleeding, although these relationships were not statistically significant. In 27 patients with hyperfibrinolysis, five (18.5%) required EACA treatment for progressive mucocutaneous bleeding and/or hematoma. EACA treatment was significantly associated with higher C-P scores; greatly shortened ELT (≤50% of normal value); and abnormal levels of fibrinogen, total bilirubin, and PT, indicating that these factors may serve as predictors for EACA treatment. CONCLUSION: Hyperfibrinolytic activity was seen in 31.3% of patients with cirrhosis, which is correlated with higher C-P scores; abnormal PT, PTT, fibrinogen level, and platelet count; and hyperbilirubinemia. Patients who received EACA treatment usually have a more severe hyperfibrinolytic activity as indicated by shortened ELT and low level of fibrinogen, and more severe liver disease as indicated by higher C-P scores and hyperbilirubinemia.
Fluorescence Polarization Immunoassay of Kanamycin

Abstract Kanamycin, an aminoglycoside antibiotic, is quantitated in human serum by a fluorescence polarization immunoassay employing a novel sulfonamido derivative of 2-naphthol-6-sulfonic acid.
Synthesis and Structural Characterization of Magnesium Amide Complexes Containing −N[(R)(SiMe3)] Ligands

Reaction of anhydrous magnesium bromide with 2 equiv of Me3Si(R)NLi (R = i-Pr, benzyl, mesityl, and SiMe2t-Bu) in diethyl ether at ambient temperature followed by treatment with donor solvents such as THF, hexamethylphosphoramide (HMPA), pyridine (py), or 4-(dimethylamino)pyridine (DMAP) affords [(Me3Si)(R)N]2Mg(L)n [R = i-Pr, L = DMAP, n = 2, 1; R = benzyl, L = DMAP, n = 2, 2; R = benzyl, L = HMPA, n = 2, 3; R = mesityl, L = THF, n = 2, 4; R = mesityl, L = py, n = 2, 5; R = SiMe2t-Bu, L = py, n = 1, 9]. If R is cyclohexyl (Cy), the reaction in diethyl ether initially yields the solvent-free dimer Mg2[N(Cy)(SiMe3)]4, 6, which reacts with excess DMAP to yield Mg[N(Cy)(SiMe3)]2(DMAP)2, 7. If R is either the sterically crowded ligand SiPh2t-Bu or adamantyl (Ad), the reaction produces solvent-free Mg[N(SiPh2t-Bu)(SiMe3)]2, 8, and Mg[N(Ad)(SiMe3)]2(Et2O), 10, respectively. All of these complexes were characterized by spectral and analytical data. The structures of complexes 1, 2, and 4−10 were confirmed by sin...
The physiology of hibernation in common map turtles (Graptemys geographica).

Map turtles from Wisconsin were submerged at 3 degrees C in normoxic and anoxic water to simulate extremes of potential respiratory microenvironments while hibernating under ice. In predive turtles, and in turtles submerged for up to 150 days, plasma PO2, PCO2) pH, [Cl-], [Na+], [K+], total Mg, total Ca, lactate, glucose, and osmolality were measured; hematocrit and body mass were determined, and plasma [HCO3-] was calculated. Turtles in anoxic water developed a severe metabolic acidosis, accumulating lactate from a predive value of 1.7 to 116 mmol/l at 50 days, associated with a fall in pH from 8.010 to 7.128. To buffer lactate increase, total calcium and magnesium rose from 3.5 and 2.0 to 25.7 and 7.6 mmol/l, respectively. Plasma [HCO3-] was titrated from 44.7 to 4.3 mmol/l in turtles in anoxic water. Turtles in normoxic water had only minor disturbances of their acid-base status and ionic statuses; there was a marked increase in hematocrit from 31.1 to 51.9%. This study and field studies suggest that map turtles have an obligatory requirement for a hibernaculum that provides well-oxygenated water (e.g. rivers and large lakes rather than small ponds and swamps) and that this requirement is a major factor in determining their microdistribution.
Gene expression in peripheral blood differs after cardioembolic compared with large-vessel atherosclerotic stroke: biomarkers for the etiology of ischemic stroke.

There are no biomarkers that differentiate cardioembolic from large-vessel atherosclerotic stroke, although the treatments differ for each and ~30% of strokes and transient ischemic attacks have undetermined etiologies using current clinical criteria. We aimed to define gene expression profiles in blood that differentiate cardioembolic from large-vessel atherosclerotic stroke. Peripheral blood samples were obtained from healthy controls and acute ischemic stroke patients (< 3, 5, and 24 h). RNA was purified, labeled, and applied to Affymetrix Human U133 Plus 2.0 Arrays. Expression profiles in the blood of cardioembolic stroke patients are distinctive from those of large-vessel atherosclerotic stroke patients. Seventy-seven genes differ at least 1.5-fold between them, and a minimum number of 23 genes differentiate the two types of stroke with at least 95.2% specificity and 95.2% sensitivity for each. Genes regulated in large-vessel atherosclerotic stroke are expressed in platelets and monocytes and modulat...
Intrathyroidal parathyroid glands: small, but mighty (a Napoleon phenomenon).

Background Intrathyroidal parathyroid adenomas (ITPAs) are a rare entity. The aim of this study is to describe the experience of 2 endocrine surgery centers and to distinguish characteristics of intrathyroidal parathyroid adenoma and nonintrathyroidal parathyroid adenomas. Methods We included patients who had undergone operations for primary hyperparathyroidism who had intrathyroidal parathyroid adenomas. Patients with single intrathyroidal parathyroid adenomas were also compared to age- and sex-matched controls with nonintrathyroidal parathyroid adenomas. Results Of 4,868 patients who underwent parathyroidectomy between January 2002 and June 2011, we identified 53 (1%) patients with intrathyroidal parathyroid adenoma. Sestamibi and ultrasound scans correctly identified the adenoma in 35 (70%) and 11 (61%) cases, respectively. Single adenomas were identified in 44 (83%) patients, double adenomas in 4 (8%) patients, and hyperplasia in 5 (9%) patients. Lobectomy was performed in 17 (32%) patients; enucleation was used in 36 (68%) patients. Cure was achieved in all patients and no patients experienced a recurrence. Patients with single intrathyroidal parathyroid adenomas had significantly smaller glands than patients with nonintrathyroidal parathyroid adenomas (325 ± 47 vs 772 ± 61 mg; P Conclusion Single intrathyroidal parathyroid adenomas are smaller than nonintrathyroidal parathyroid adenomas, but patients with intrathyroidal parathyroid adenomas present with similar laboratory values and symptoms. Recognition of this rare entity can lead to a successful surgical outcome.
A critical discourse analysis of teachers’ views on LGBT literature

This article presents a thread of discussion posted to a web-based forum in the context of a children's literature course in one teacher education program in the USA. Participants in the virtual discussion include three preservice elementary teachers and the course instructor (author) on the subject of bringing lesbian, gay, bisexual and transgender (LGBT) literature into the elementary classroom. Classroom teachers who lead discussions about race, gender, class, sexuality and inequality are encouraged to create and maintain a safe environment for dialogue. In this article, the author explores how the need to maintain a culture of safety around discussions of sexuality shaped the participants’ views on teaching LGBT literature written for children. Applying the tools of critical discourse analysis, the author demonstrates how events in the discussion unfolded that left normative constructions of sexuality unexamined.
Comparison of Three Methods for Human Corneal Cryopreservation That Utilize Dimethyl Sulfoxide

We compared endothelial cell survival in human corneas after cryopreservation by three methods that utilize dimethyl sulfoxide. Twenty-eight human cadaver corneas were cryopreserved by one of three methods, stored briefly over liquid nitrogen, thawed, cultured at 37 degrees C for 3 days, and fixed for scanning electron microscopy. Seventeen control corneas underwent identical cryoprotectant immersion and culture protocols but were not frozen. Endothelial photographs taken after 1 and 3 days of culture were analyzed. Endothelial cell losses in cryopreserved corneas by Methods 1, 2, and 3, respectively, were 36, 22, and 10% after 1 day of culture and 57, 36, and 27% after 3 days of culture. Cryopreservation by Method 3 had less cell loss than Methods 1 or 2 (P<0.02) but greater cell loss than the control corneas for Method 3 (P<0.001). No loss of cells occurred in the control corneas for Methods 1 and 3 but substantial cell loss (26%) occurred in the control corneas for Method 2. Polymegethism and pleomorphism of the endothelial cells were seen in the corneas that lost cells. The endothelial cell loss of 10% seen after 1 day of culture in human corneas cryopreserved by Method 3 is similar to the loss that occurs during organ culture storage as currently used clinically and therefore would be acceptable for clinical use. After 3 days of culture, however, the cell loss had increased significantly to 27%. This additional decrease in cell number that occurs in culture may represent latent cryodamage and must be understood and overcome in vivo before the technique can be used clinically.
Using apprenticeship techniques to guide constructive induction

Abstract Constructive induction is a means of improving classification accuracy in difficult domains by transforming a difficult domain into a form amenable to standard induction techniques by constructing new features. When performing constructive induction, though, a learning system faces a combinatorial explosion of potential features to construct, but only a small fraction of these will prove to be useful. The challenge lies in identifying enough of these useful constructed features to achieve sufficient accuracy while examining as little as possible of the space of potential constructed features. This paper presents how apprenticeship techniques (Mitchell et al. , 1985; Hall, 1988; Wilkins, 1988; Tecuci & Kodratoff, 1990) can be used to guide the feature construction process by focusing attention on weak areas of a learned knowledge base. The method used is to run a splitting algorithm (such as CART, PLS1, or C4.5) to build a knowledge base, employ apprenticeship techniques to detect and localize knowledge base deficiencies, use this information to construct new features, and then repeat the cycle as necessary (i.e. until a desired accuracy is reached). We show how this method improves accuracy on a range of classification problems and discuss why the combination of apprenticeship as a knowledge acquisition method and constructive induction as a machine learning method overcomes key weaknesses of each of these methods used separately.