cssi/SciSciGPT-SciSciNet huggingface dataset:
Discrete Rayleigh fading channel modeling

In order to understand the behaviour of upper-layer protocols and to design or fine tune their parameters over wireless networks, it is common to assume that the underlying channel is a flat Rayleigh fading channel. Such channels are commonly modeled as finite state Markov chains. Recently, hidden Markov models have also been employed to characterize these channels. In this paper, we study the different models that have been proposed along with the analysis of their validity. We start by presenting some preliminary concepts related to the modeling of the wireless communications channel. We then proceed to introduce finite state Markov channel models (FSMCs) along with the relations between them and the modulation schemes, error control protocols and channel coding. We propose and study the effects of taking into account the fading process in its characterization. We finish with a discussion on hidden Markov models for Rayleigh fading channel modeling. Copyright © 2004 John Wiley & Sons, Ltd.
Conflicts between conservative Christian institutions and secular groups in sub-Saharan Africa: Ideological discourses on sexualities, reproduction and HIV/AIDS

Religious and secular institutions advocate strategies that represent all points on the continuum to reduce the spread of HIV/AIDS. Drawing on an extensive literature review of studies conducted in sub-Saharan Africa, we focus on those secular institutions that support all effective methods of reducing HIV/AIDS transmission and those conservative religious institutions that support a limited set of prevention methods. We conclude by identifying topics for dialogue between these viewpoints that should facilitate cooperation by expanding the generally acceptable HIV/AIDS prevention methods, especially the use of condoms.
Alcohol myopathy: impairment of protein synthesis and translation initiation.

Alcohol consumption leads to numerous morphological, biochemical and functional changes in skeletal and cardiac muscle. One such change observed in both tissues after either acute alcohol intoxication or chronic alcohol consumption is a characteristic decrease in the rate of protein synthesis. A decrease in translation efficiency appears to be responsible for at least part of the reduction. This review highlights advances in determining the molecular mechanisms by which alcohol impairs protein synthesis and places these observations in context of earlier studies on alcoholic myopathy. Both acute and chronic alcohol administration impairs translational control by modulating various aspects of peptide-chain initiation. Moreover, this alcohol-induced impairment in initiation is associated with a decreased availability of eukaryotic initiation factor (eIF) 4E in striated muscle, as evidenced by an increase in the amount of the inactive eIF4E.4E-BP1 complex and decrease in the active eIF4E.eIF4G complex. In contrast, alcohol does not produce consistent alterations in the control of translation initiation by the eIF2 system. The etiology of these changes remain unresolved. However, defects in the availability or effectiveness of various anabolic hormones, particularly insulin-like growth factor-I, are consistent with the alcohol-induced decrease in protein synthesis and translation initiation.
Selective Visual Experience Fails to Modify Receptive Field Properties of Rabbit Striate Cortex Neurons

During development, rabbits were exposed only to vertical or horizontal lines to determine if the receptive field characteristics of visual cortex cells would be altered as they are in the cat. Motion and directional selectivity were preserved, and orientation specificity remained unaffected by the restricted experience, which suggests that the rabbit may lack the neural plasticity seen in some other mammals.
Ionizing Radiation Effects on Starch as Shown by Staudinger Index and Differential Thermal Analysis

SUMMARY— Corn starch in the form of raw granules at commercial moisture was irradiated at two levels: 3 × 105 and 6 × 106 rad from a Co60 source. The irradiated samples were completely dissolved in alkali, indicating there was no cross linking induced in the starch molecules by irradiation. Viscosity determinations of starch solution diluted with distilled water exhibited the ion charge effect generally observed in other macromolecules. The Staudinger indices of unirradiated, irradiated at 3 × 106 rad and 6 × 106 rad were 42, 22 and 16 respectively, which were an indication of depolymerization of starch macromolecules with increasing irradiation. The differential thermal analysis of the three samples also showed the depolymerization of the polymer with irradiation. It is suggested that these two simple techniques–the Staudinger index and D.T.A.–could be usefully employed to characterize small differences in starches.
Targeted overexpression of an activated N-ras gene results in B-cell and plasma cell lymphoproliferation and cooperates with c-myc to induce fatal B-cell neoplasia.

Multiple myeloma is an incurable malignant expansion of plasma cells in the bone marrow. Although there is no pathognomonic genetic lesion among multiple myeloma patients, activation of the ras gene has been identified as a common mutation. We have previously described the use of the 3′ κ immunoglobulin light chain enhancer (3′KE) to target transgenic expression in murine B and plasma cells, resulting in bcl-X L and c- myc –driven murine models of multiple myeloma. In this report, we characterize the role of activated mutant N- ras in B and plasma cells in transgenic mice. We constructed transgenic mice that use 3′KE to direct expression of a mutant activated N- ras . We also crossed the N- ras mice with mice bearing a c- myc transgene to study the cooperative effects of the transgenic constructs. Mice were sacrificed when moribund or at specific time intervals and characterized by serology, light microscopy, and flow cytometry. The transgenic N- ras animals develop B- and plasma cell lymphoproliferation, and aged mice develop immunoglobulinemia, renal hyaline tubular casts, and microscopic foci of abnormal plasma cells in extramedullary sites, including the liver and kidney. Bitransgenic 3′KE/N-Ras V12 × Eμ-c-Myc mice develop fatal B-cell neoplasia, with a median survival of 10 weeks. These data indicate that activated N- ras can play a role in B- and plasma cell homeostasis and that activated N-Ras and c-Myc can cooperate to induce B-cell neoplasia.
Multiple core homeodomain binding motifs differentially contribute to transcriptional activity of the murine gonadotropin-releasing hormone receptor gene promoter.

Multiple homeodomain (Hbox) proteins have been shown to organize expression of key markers of gonadotropes. Nine putative Hbox-binding sites, characterized by the homeospecific TAAT motif, are located within the proximal 600 bp of the murine GnRHR promoter. Homeoproteins bind separate Hbox sites within this promoter, supporting basal- and endocrine-directed transcription. The function of the most proximal sites (Hbox1 and Hbox2) in the murine GnRHR is unknown; thus, understanding of the global contribution of homeospecific TAAT sites to promoter function is incomplete. Site-directed mutagenesis revealed that loss of Hbox2 reduced promoter activity in a cell-specific manner, having no effect in αT3-1 cells but reducing promoter function in LβT2 cells, another gonadotrope-derived cell line representing a later developmental stage. In contrast, eliminating Hbox1 reduced basal activity in both lines. This region displayed specific binding to homeoprotein Oct-1. Mutagenesis of a previously identified Oct-1-binding site in concert with Hbox1 led to further reduction in activity. We suggest that the two most proximal homeodomain-binding sites in the murine GnRHR promoter may regulate the promoter in a developmentally dependent fashion and that Oct-1 acts at multiple but distinct TAAT sites to support basal transcription.
Peanut skin procyanidins: Composition and antioxidant activities as affected by processing

Abstract Peanut skin was removed by direct peeling, blanching, and roasting. Total phenolics (TPs), total antioxidant activity (TAA) and free radical scavenging capacity of peanut skin extracts were determined. The composition of ethanolic extracts of peanut skin obtained from each processing method was determined by LC-MS and HPLC. Peanut skin processing methods significantly affected total extractable phenolics and their composition. Roasting had limited effects on concentration of TPs while blanching caused 89% loss of TPs. TPs in directly peeled, roasted, and blanched peanut skins were 130, 124, and 14.4 mg/g dry skin, respectively. Catechins, A-type and B-type procyanidin dimers, trimers and tetramers in chemically purified peanut skin extracts were identified by LC-MS. Total catechins, procyanidin dimers, trimers and tetramers in directly peeled peanut skin were 16.1, 111.3, 221.3 and 296.1 mg/100 g, respectively, versus 8.8, 143.5, 157.5 and 203.9 mg/100 g, respectively, in roasted dry skin. TAAs and free radical scavenging capacities of peanut skin extracts were all higher than those of Trolox and Vitamin C at equivalent concentration. Peanut skin, a by-product of the peanut processing industry, was found to contain potent antioxidants and could provide an inexpensive source of antioxidants for use as functional ingredients in foods or dietary supplements.
Xenon spallation systernatics in Angra dos Reis

Literature Xe data for the Angra dos Reis meteorite have been resolved into constituent spallation, fission and trapped components. The spallation Xe compositions vary over a range wider than observed in any other samples, including lunar samples. These variations are due to the mixing of spallation Xe from Ba and rare earth element targets. It is possible to infer the Ba and rare earth spallation Xe compositions. Angra dos Reis spallation Xe compositions are systematically different from those observed in lunar samples, possibly because of differences in the irradiation conditions (geometry and shielding). Thus the Angra dos Reis data appear to be superior to lunar data for predicting spallation Xe compositions in other meteorites.
ARE BASKETBALL ARENAS CATALYSTS OF ECONOMIC DEVELOPMENT

Academic researchers continue to challenge the popular perception that new or renovated stadiums are catalysts of economic development. Despite basketball arenas generally having lower construction...
ON THE DESIGN OF DISCRETE-TIME FIXED-ORDER CONTROLLERS FOR PERSISTENT DISTURBANCE REJECTION

Abstract The focal point of this paper is the design of fixed-order controllers for persistent disturbance rejection. It is shown that optimal controller design can, in this case, be formulated as a generalized eigenvalue problems. The results in this paper rely on an extension of the concepts of equalized performance and superstability to the case of multi-input/multi-output systems described by transfer function matrices. The efficacy of the algorithm provided is illustrated via a numerical example.
Single-balloon enteroscopy: results from an initial experience at a U.S. tertiary-care center

Background Single-balloon enteroscopy (SBE) is a novel, deep-enteroscopy modality for diagnosis and treatment of disorders of the small bowel. Objective The aim of the study was to examine the performance, yield, and safety of SBE in the initial experience at a tertiary-care center. Design Retrospective analysis of all SBEs during a 10-month period in 2008. Data were extracted from electronic clinical and endoscopy records. Setting U.S. tertiary-care center. Patients All patients referred to our center for SBE during the study period were included in the current analysis. Intervention SBE. Main Outcome Measurements Anterograde SBE procedure time, diagnostic yield, and complications. Results Thirty-eight anterograde SBEs were performed. The mean patient age was 62 years (42% female). Patients were referred for GI bleeding (97%), Crohn's disease, suspected polyps or neoplasia, and abnormal capsule endoscopy results. The mean (± SD) procedure time was 49 ± 19 minutes. The estimated depth of insertion was proximal jejunum (34%), mid-jejunum (45%), and distal jejunum (21%). The SBE diagnostic yield was 47%, with significant findings in 18 patients. Findings included angiectasias, bleeding, abnormal mucosa, ulceration, polyps, and a foreign body. The therapeutic yield was 42%, with lesion ablation performed in 24% of cases. Diagnostic biopsies were performed in 24% of cases and tattooing in 52%. There were no significant complications. Limitations Single-center, retrospective study. Conclusion Single-balloon enteroscopy appears to be a safe and efficient method for examination of the mid-small bowel. The significant therapeutic yield (42%) suggests that comparative studies with double-balloon and spiral enteroscopy are warranted.
Interpersonal Risk Profiles for Youth Depression: A Person-Centered, Multi-Wave, Longitudinal Study

Independent lines of research illustrate the benefits of social support and the negative consequences of conflict and emotional neglect across family and peer contexts with regard to depression. However, few studies have simultaneously examined negative and positive interactions across relationships. We sought to address this gap in the literature by utilizing a person-centered approach to a) understand empirical, interpersonal profiles in youth and b) understand how these profiles confer risk for prospective depression. At baseline, 678 youth (380 females; 298 males) 3rd (N = 208), 6th (N = 245), and 9th graders (N = 225) completed self-report measures for self-perceived negative/positive relationships across family and peers, anxiety symptoms, and depressive symptoms in a laboratory setting. Next, youth were called every 3 months for 18 months and completed self-report depressive and anxiety symptom forms. Two-step cluster analyses suggested that children and adolescents fell into one of three interpersonal clusters, labeled: Support, Conflict, and Neglect. Our analyses supported a convergence model in which the quality of relationship was consistent across peers and family. Furthermore, mixed-level modeling (MLM) findings demonstrated that youth in the Conflict cluster were at increased risk for prospective depressive symptoms, while the Supported and Neglected profiles demonstrated similar symptom levels. Findings were unique to depressive symptoms and consistent across sex and age. Conflict seemed to uniquely confer risk for depression as findings concerning anxiety were not significant. These findings influence our interpersonal conceptualization of depression as well as clinical implications for how to assess and treat depression in youth.
The State Connection in China's Rural- Urban Migration

This study explores the role of China's rural local state-owned and urban state-owned units in its rural-urban migration process. Most studies on Chinese migration have focused on migrants moving from rural to urban areas through informal mechanisms outside of the state's control. They therefore treat the Chinese state as an obstructionist force and dismiss its facilitative role in the migration process. By documenting rural local states' “labor export” strategies and urban state units' employment of millions of peasants, this article provides a corrective to the existing literature. It highlights and explains the state connection in China's rural-urban migration.
Torture in the Eye of the Beholder: Social Identity, News Coverage, and Abu Ghraib

This study compares how the 2004 Abu Ghraib prison story was defined by journalists in seven countries (Australia, Britain, Canada, Germany, Italy, Spain, and the United States). A content analysis of leading print news outlets from each country reveals a range of politically significant descriptive labels. At one extreme, American journalists overwhelmingly avoided torture to describe Abu Ghraib, emphasizing instead more ambiguous, and arguably more innocuous, terms such as abuse or mistreatment. At the other extreme, German, Italian, and Spanish journalists tended to define what happened at the prison as torture rather than as abuse or mistreatment. In between these emphases were Australian, British, and Canadian journalists, who fell somewhat closer to the characterizations employed by U.S. journalists. Our view is that these divergences in news coverage are best explained by social identity theory, though other potential explanations are also considered.
Energy Transfers between Sensitizer and Substrate. III. Sensitization by Thick Dye Films

Photoconductivity can be sensitized in cadmium sulfide films by specially prepared films of pinacyanole and kryptocyanine having a thickness ~1 micron. Preparations of this sort offer considerably more opportunity for experimentation than those sensitized by monolayers of dyes. Their properties are such as to support the validity of the electron-transfer mechanism in this case.
Effects on operations of highly adaptive missions

A nonadaptive operations strategy was used by the Magellan mission to Venus, whereas an adaptive strategy was used for the Spaceborne Imaging Radar-C mission to Earth. The operational strategies employed by these missions are described, along with overviews of both missions and a summary of their systems and capabilities. The effects of adaptivity on the operations systems are discussed, and a summary of advantages of each strategy is given.
Synthesized Speech Intelligibility in Sentences: A Comparison of Monolingual English-Speaking and Bilingual Children

Purpose: Research comparing the intelligibility of human and synthesized speech among both young children and adults has indicated that synthesized speech results in a degrading of intelligibility. The purpose of this study was to compare speech intelligibility of high-probability sentences produced using DECtalk® Perfect Paul and live speech among monolingual English-speaking and bilingual children. Method: Twenty typically developing children between the ages of 4;5 (years;months) and 6;2 participated. Ten children (6 boys and 4 girls) were monolingual English speakers. The remaining ten children (4 boys and 6 girls) were bilingual. Their reproduction of modeled sentences produced in English via live speech and synthesized speech were analyzed to determine the intelligibility of each speech type. Results: The results indicated that for both groups of children, performance was significantly better in the live speech condition. Results further revealed that the intelligibility decrement for synthesized sp...
Cerebrospinal fluid human immunodeficiency virus type 1 (HIV-1) p24 antigen levels in HIV-1–related dementia

Human immunodeficiency virus type 1 (HIV-1) p24 antigen, a putative marker of virus load, was assayed in 79 blood and 83 cerebrospinal fluid (CSF) samples from 90 HIV-1-seropositive individuals with or without dementia. Twenty-eight subjects had no evidence of neuropsychological impairment, 17 had mild impairment without objective evidence of dementia, and 45 were demented. HIV-1 p24 antigen was detected more frequently in CSF samples from demented (19/40) than normal (1/26) or mildly impaired (1/17) subjects and in 67% of individuals with significant dementia (MSK stages 2-4). p24 Antigen was detected less frequently in CSF from demented subjects on antiretroviral drugs than untreated demented individuals. Overall, the sensitivity of the antigen capture assay in CSF among demented individuals was 47.5%; the specificity, 95.0%; positive predictive value, 90.4%; negative predictive value, 66.1%; and the efficiency, 72.2%. A direct relationship was also noted between the degree of cognitive impairment and blood p24 antigen detection frequency and antigen concentration. CD4+ blood lymphocyte counts were lower for demented individuals, and HIV-1 p24 antigen was detected more frequently and p24 antigen concentration was higher in blood and CSF from individuals with low CD4+ blood lymphocyte counts. beta 2-Microglobulin levels were higher in CSF from demented subjects and correlated directly with CSF p24 antigen concentration. However, in contrast to CD4+ blood lymphocyte counts and beta 2-microglobulin levels, only p24 antigen concentration correlated with dementia severity. Therefore, p24 antigen can be a useful marker for dementia related to HIV-1 infection.
BCL3 and notis: An automated collection analysis project

The availability of the third edition of Books for College Libraries in machine-readable format opens up new possibilities for using computer technology for collection analysis, particularly if a library's holdings are also in machine-readable format. Preliminary results from a collection analysis project at the Kent State University Libraries are presented. The project features a database created from the Books for College Libraries file that includes local subject categories and holdings status. Initial automated matching of records from the database against the Libraries' holdings was performed by a microcomputer workstation wired to the online catalog. Nonmatching records are being searched manually as a follow-up.
Differences in the cyclic nucleotide mediation of luteinizing hormone-releasing hormone action on the rat and hamster anterior pituitary gland.

Abstract A continuous flow superfusion system which was previously developed in our laboratory was utilized to study the modulation of LH and FSH release by cyclic nucleotides and LHRH from anterior pituitary glands (APG) obtained from rats or hamsters. There was a transient increase in LH and FSH secretion from superfused rat APG in response to superfusion with 1 × 10 −3 M 1-methyl-3-isobutyl-xanthine (MIX), while 1 × 10 −4 MIX M had no effect. Furthermore, a dose of 5 × 10 −5 M MIX did not potentiate the gonadotrophin-releasing effect of 1 × 10 −10 M LHRH. Neither 1 × 10 −3 M 8-Br-cAMP nor 1 × 10 −3 M 8-Br-cGMP mimicked the gonadotrophin-releasing effects of 1 × 10 −9 M LHRH. In the experiments utilizing hamster APG, FSH release gradually increased during superfusion with 1 × 10 −3 M MIX or 1 × 10 −4 M MIX, while LH release was transient but significantly increased in response to superfusion with both doses of MIX. A dose of 5 × 10 −5 M MIX potentiated the effect of a low dose of LHRH (1 × 10 −10 M) upon both LH and FSH secretion. 1 × 10 −3 M 8-Br-cAMP mimicked the effect of LHRH upon LH and FSH released from superfused hamster APG, while 1 × 10 −3 M 8-Br-cGMP was inhibitory. These results suggest that cyclic nucleotides are involved in the mediation of the LHRH-induced release of gonadotropins from the anterior pituitary gland of the hamster, but do not mediate the LHRH-induced release of gonadotropins from the rat anterior pituitary gland.
Emotion Congruent Facilitation of Attention when Processing Anxious Stimuli

Researchers using spatial attention tasks have shown that anxious individuals are quick to orient to threatening information, but have difficulty disengaging attention from that location. We extended this line of research by investigating the influence of anxiety on attention across time rather than space. It was found that anxious words imbedded in a rapidly presented stream of distractors were correctly identified more often than neutral words, regardless of the emotional state of the participant. Having identified the first target in the stream, participants were able to detect a second target sooner when the first target was an anxious word and the participant was experiencing anxiety in comparison to conditions in which the first target was neutral or the participant was not anxious. The rapid recovery of the attentional system when there was emotional congruence between the state of the individual and the attended information, points to the unique influence that anxiety has on attention across time in comparison to its influence on spatial attention.
111Indium-tropolone labeled human PMNs A rapid method of preparation and evaluation of labeling parameters

Pure polymorphonuclear leukocytes (PMNs) have been isolated from a small amout of human blood by a single-step density gradiant centrifugation method using a commercially available Ficoll-Hypaque mixture of density 1.114. The cells were labelled with [111]Intropolone in both buffer and plasma. Cell viability, ability to generate superoxide anion, and chemotaxis were found to be unaltered both before and after labeling. The optimum tropolone concentration for labeling was found to be 1 × 10−4 M. Labeling efficiency was higher at 37°C than at room temperature. Compared to [111In]oxine, tropolone preparation both in buffer and plasma resulted in consistently higher yields. Preliminary experiments of in vivo cell viability of the labeled PMNs were carried out in rabbits. The ability of the cells to localize in experimentally produced inflammatory lesions was found to be intact. The method of cell separation and labeling described has been found to be simple and rapid and could easily be incorporated in routine nuclear medicine laboratory practice.
High tone spread in Ekegusii revisited: An optimality theoretic account

Abstract Ekegusii, a Kenyan Bantu language, exhibits a complex array of tonal patterns in the finite verbal system including bounded High displacement, bounded High spreading, and unbounded High spreading, each of which is ‘blocked’ from applying in certain configurations. Bickmore (1997) provided a derivational analysis of these facts, but found basic assumptions regarding adjacency and the OCP had to be abandoned to achieve descriptive adequacy. This paper re-analyzes the Ekegusii data within Optimality Theory and eschews the major problems found in the derivational account. It is shown that the surface tonal patterns are the result of a delicate interplay between the productivity of various tonal processes and the avoidance of certain tonal structures. Several theoretical proposals are made in the areas of: 1. (1) constraint sensitivity to lexical strata, 2. (2) tone and accent interaction in OT, 3. (3)bounded spreading as ‘minimal misalignment’, and 4. (4) underspecification of the edge parameter in an ALIGN constraint.
Opponent chromatic induction: experimental evaluation and theoretical account.

The concept of physiologically based, opponent chromatic induction is fundamental to the opponent-colors theory. A continued quantitative development of this theory to account for color perceptions, equations, and discriminations under various conditions of adaptation and illumination has emphasized the need for systematic quantification of induced color effects. Experiments are reported in which a color-matching technique was used to compare the chromatic responses to focal stimuli seen first in isolation and then in the presence of surrounding stimulus arrays of specified luminances and chromaticities and of various degrees of complexity. The results are analyzed in terms of the chromatic response processes of the opponent-colors theory. Chromatic inductions are shown to decrease systematically with decreasing contiguity of focal and surround stimulus areas. For given degrees of contiguity, induced chromatic responses are shown to be opponent to but proportional in magnitude to the mean chromatic activities of the inducing field, and the constant of proportionality decreases as a function of decreasing contiguity.
A soft-tissue calcification: differential diagnosis and pathogenesis.

: An autopsy of a 72-year-old white male revealed a 30.5 × 5.1 cm vertically aligned heterotopic ossification just deep to a 30.5 cm midline abdominal scar. The ossified mass was determined to be a heterotopic ossification or myostitis ossificans (MO) traumatica resulting from an abdominal surgical incision during life. While, MO traumatica is relatively common accounting for roughly 60–75% of patients with soft-tissue ossification, heterotopic ossification of abdominal incisions are relatively rare and thus infrequently reported. This article details the manifestation of this relatively large heterotopic bone and provides a comprehensive review of the literature and pathogenesis of this unusual ossification. A review of the English literature from 1920 to the present produced only a handful of articles for a total of 185 reported cases. All had bone formed within vertical incisions, usually within 1 year of surgery, and 89% were males. Knowledge of this phenomenon and the variable size at presentation is useful to both the autopsy pathologist and the anthropologist in generating a diagnosis for abnormal calcifications.
Optical Heterodyne Signal Power Obtained from Finite Sized Sources of Radiation

A general expression for the optical heterodyne signal power from a finite-sized radiation source is derived that is formally valid for an arbitrary degree of coherence of the source. The signal power is given explicitly in terms of those variables that describe the source of radiation (e.g., total radiated power, brightness distribution, and source size). Finite-sized incoherent and coherent sources are examined in detail, and analytic expressions are derived for various geometries of experimental interest. For a finite-sized incoherent source, we derive a generalization of Siegman’s results for an extended incoherent source, which states that the effective or capture area of the receiver integrated over its field of view is equal to the square of the optical wavelength. In addition, we derive an analytic expression for the heterodyne signal power for a coherent Gaussian laser source and a Gaussian local oscillator. In contrast to the case of an incoherent source, in which the heterodyne signal power increases in proportion to receiver area, the heterodyne signal power from a coherent source tends asymptotically to a constant with increasing receiver area. This implies that, in a shot-noise-limited system, the SNR tends to a constant or decreases inversely as the receiver area for incoherent or coherent sources, respectively.
KCNE3 Stabilizes the Voltage Sensor S4 of KCNQ1 Channel, KCNE1 Uncouples S4 and the Gate

KCNEs are single-span transmembrane β-subunits that assemble with and modulate the biophysical properties of voltage-gated K+ (Kv) channels. In the heart, the pore forming α-subunit KCNQ1 associates with KCNE1 to form the slowly-activating, voltage-gated IKs channels that contribute to the repolarization of the cardiac action potential. In tissues such as the colon, stomach and kidney, KCNQ1 coassembles with the β-subunit KCNE3 to form voltage-independent K+ channels important for K+ and Cl- secretion. KCNE3 has also been shown to be expressed in the human heart, although its physiological function remains unknown. Different mechanisms have been proposed to explain how different KCNE subunits alter KCNQ1 gating and permeation. For instance, KCNE3 is assumed to lock the voltage sensor (S4) of KCNQ1 channel in the activated state, resulting in a constitutively open channel. Here, we use voltage clamp fluorometry (VCF) to understand how KCNE3 affects the voltage sensor and the gate of KCNQ1 channel. We show that KCNE3, contrary to what was previously assumed, allows S4 movement in KCNQ1/KCNE3 channels. KCNE3 shifts the closing and S4 movement of KCNQ1 to extreme hyperpolarized potentials, such that at physiological voltage range (−80 mV to +40 mV), the channel is always open. By decoupling S4 and the gate, either by mutations or PIP2 depletion, we show that KCNE3 mainly affects S4 movement in KCNQ1. Two negatively charged residues in the N-terminus of KCNE3 (D54 and D55) are, at least partly, responsible for stabilizing S4 in an outward position, therefore stabilizing KCNQ1/KCNE3 channels in the activated open state. Further, we unitized a triple mutation of KCNE3, previously shown to convert KCNQ1/KCNE1 channel to a KCNQ1/KCNE1-like current, and observe a decoupling of S4 and the gate
On two set-systems with restricted cross-intersections

Abstract If A 1 , …, A m ; B 1 , …, B m are finite sets such that for l ⩾ t ⩾ 0 and any r , s , we have | A i | ⩽ r , | B i | ⩽ s and | i ∩ B i | ⩽ t for 1 ⩽ i ⩽ m and | A i ∩ B i | > l for 1 ⩽ i j ⩽ m , what is the maximum value that m can attain? In this paper we answer this question of Furedi and extend an inequality of Bollobas.im]0658.TIF
Neotectonics of Hispaniola: plate motion, sedimentation, and seismicity at a restraining bend

The question as to the extent to which earthquake mechanisms define plate motion is addressed in view of the pattern of Neogene faulting, volcanism, and sedimentation in Hispaniola. The structure of two fault systems that approximately define the northern and southern coasts of the island suggest an east-west trend in relative plate motion, which is consistent with previous findings. The intervening area consists of en echelon mountain ranges thrust up at the restraining bend from the early Miocene. A Pleistocene volcanic province within this area is interpreted as defining a diffuse extensional fault termination of the southern strike-slip fault zone.
Intestinal Absorption of Griseofulvin from a Triolein Digestion Mixture in Rats

The intestinal absorption rate of dissolved griseofulvin was determined from: (a) an aqueous phase, (b) an aqueous phase containing a micellar phase composed of taurodeoxycholate, monoolein, and oleic acid, and (c) an aqueous phase containing the micellar phase and emulsified triolein. The triolein digestion mixtures were recirculated through 20-cm segments of in situ rat jejunum. Lipid concentrations were maintained constant by infusing the lipids into the digestion mixture at the same rate as they disappeared. Griseofulvin distribution among the aqueous, micellar, and oil phases was determined by solubility and equilibrium dialysis experiments. Analysis with a linear kinetic model indicated that griseofulvin absorption from the micellar and oil phases was negligible compared to its absorption from the aqueous phase.
Optical crossbar switch based on total internal reflection: technology and applications

We begin by reviewing the likely evolution of long-haul optical networks, and the role of optical cross connects (OXCs) in this evolution. We examine technologies for the switch fabrics in these OXCS, and focus on a guided-wave optical crossbar matrix based on total internal reflection. We argue that the reliability, modularity and scalability of crossbar matrix switches make them attractive for many applications.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Compliance with antibiotic therapy: A comparison of deuterium oxide tracer, urine bioassay, bottle weights, and parental reports*

Objective : To compare three traditional measures of compliance with antiblotic therapy (parent report diary, preregimen and postregimen bottle-weight difference, and urine biosssay for antibiotic activity) with a deuterium oxide tracer measure of compliance. Methods : Clinical trial in which all four compliance measures were used for subjects participating in a comparison of the efficacy of azithromycin and penicillin in treating group A β-hemolytic streptococcal infection. Subjects were 41 children, aged 3 to 15 years (average age, 7.9 years), in a suburban pediatric private practice, who had positive rapid streptoccccal antigen test results. Results : Of the 41 subjects, 20 children were randomly assigned to receive azithromycin and 21 to receive penicillin. Compliance was uniformly high by all four measures. Parent diaries indicated that all doses were administered. Urine bioassays were obtained for 40 subjects, and all showed antibiotic activity. Differences in bottle weights were obtained for 27 subjects and showed that 142% of the prescribed medication was missing from the bottles at the end of the regimen. The deuterium oxide measure was obtained for 40 subjects and showed that 107% of the prescribed azithromycin and 92% of the prescribed penicillin were ingested. The correlation coefficient between measured and expected deuterium enrichment was 0.89. There was no significant correlation between the bottle-weight measure and the deuterium oxide tracer. Conclusions : The bottle-weight measure overestimates compliance; the deuterium oxide tracer is feasible for use in an office setting and produces a high correlation between the expected urinary enrichment and the measured enrichment. Increased use of this quantitative and direct measure would improve the accuracy of compliance measurement in trials of pediatric liquid medications.
Influences of sphingosine on two-stage skin tumorigenesis in Sencar mice

Sphingosine (SPH) was studied as an inhibitor of skin tumor promotion in skin cancer initiated by 7,12-dimethylbenz[a]-anthracene (DMBA) and promoted by 12-O-tetradecanoylphorbol-13-acetate (TPA). Two tumorigenesis studies were conducted using female Sencar mice treated with 10 nmol DMBA in 0.2 ml acetone at 8 weeks of age and promoted beginning 1 week later with 3.2 nmol TPA applied twice per week. In the high-dose study, 10 mumol SPH was applied 30 min before each TPA treatment. The low-dose study used 0.5, 0.05, or 0.01 mumol treatments with SPH 30 min before TPA. In the high-dose study SPH treatment alone following initiation by DMBA, and SPH treatment preceding TPA in DMBA-initiated mice accelerated the development of papillomas in comparison with the DMBA/TPA-treated group. The low-dose experiment showed no consistent alteration of tumorigenesis by SPH in the DMBA/TPA-treated groups, and low doses of SPH following DMBA did not promote skin tumorigenesis. SPH treatment did not alter body weight in either experiment.
The effect of variable magnesium intake on potential factors influencing endurance capacity.

Rats fed a magnesium (MG) deficient diet have a lower endurance capacity than rats fed Mg adequate diets. The current study evaluates the effects of marginal, moderate, and severe Mg deficiencies on physiological and biochemical changes that may contribute to the reduced endurance capacity of Mg deficient rats. Variable levels of dietary Mg (400, 200, 100, 50 μg/g) were fed for 23 d to 5-wk-old male Osborne-Mendel rats. Indirect blood pressure and heart rate were measured during dietary treatment. Forty-eight hours after an endurance test, rats were killed and sampled for plasma glucose, insulin, and triglyceride levels. Organ weights, mineral and trace element concentrations, and carcass composition were determined. Blood pressure was lower in rats fed 50 and 100 ppm Mg during the first half of the study than in controls (400 ppm Mg). There were no significant differences in blood pressure among groups at the end of the study. Heart rate was not affected by dietary Mg intake. Plasma insulin was lowered by decreasing dietary Mg; however, plasma glucose and triglyceride concentrations were not affected by dietary Mg intake. Rats fed 100 and 50 ppm Mg diets had significantly higher calcium concentrations in plasma and gastrocnemius muscle than controls. Dietary Mg variably affected tissue trace element (iron, zinc, copper, and manganese) concentrations but did not affect Mg concentrations in any organ studied. Body composition was significantly altered by dietary Mg intake. In conclusion, variable Mg intake differentially affects the parameters evaluated. Thus, the decreased endurance capacity of the Mg deficient rat is apparently not the result of a single biochemical lesion but is likely to be multifactorial.
Bioavailability of 1-nitropyrene from model coal fly ash and its uptake by alveolar macrophages.

Alveolar macrophage cultures exposed to coal fly ash vapor-coated with 1-nitropyrene were used as a model system to study the bioavailability and the uptake of a nitroaromatic hydrocarbon from coal-combustion emissions. Initially, 1-nitropyrene-coated fly ash and uncoated fly ash were examined for cytotoxicity using rabbit alveolar macrophages and for mutagenicity in the Salmonella typhimurium plate incorporation assay. The results were compared to determine the effects of vapor deposition. The distribution and recovery of 1-nitropyrene from macrophage cultures treated with coated fly ash were determined by using a reverse-phase high-performance liquid chromatography-fluorescence method. 1-Nitropyrene alone was not very toxic, nor did vapor deposition of 1-nitropyrene onto coal fly ash significantly affect the toxicity of the fly ash. Most toxicity resulted from the original, uncoated, fly ash particles, 1-Nitropyrene after being coated onto the particles was bioavailable in agar and aqueous culture medium. The coated fly ash showed mutagenic activity when the particles were tested directly; the uncoated fly ash did not show mutagenic activity. 1-Nitropyrene recovery from alveolar macrophage cultures exposed to the coated fly ash diminished as cell number increased. The rate of 1-nitropyrene loss was 2.7 ng/.000001 macrophages for medium and 4.1 ng/.000001 macrophages for the whole culture. Themore » mutagenic activity recovered from these macrophage cultures also decreased with increasing cell number.« less
Unification of two fractal families

Barnsley and Hurd classify the fractal images into two families: iterated function system fractals (IFS fractals) and fractal transform fractals, or local iterated function system fractals (LIFS fractals). We will call IFS fractals, class 2 fractals and LIFS fractals, class 3 fractals. In this paper, we will unify these two approaches plus another family of fractals, the class 5 fractals. The basic idea is given as follows: a dynamical system can be represented by a digraph, the nodes in a digraph can be divided into two parts: transient states and persistent states. For bilevel images, a persistent node is a black pixel. A transient node is a white pixel. For images with more than two gray levels, a stochastic digraph is used. A transient node is a pixel with the intensity of 0. The intensity of a persistent node is determined by a relative frequency. In this way, the two families of fractals can be generated in a similar way. In this paper, we will first present a classification of dynamical systems and introduce the transformation based on digraphs, then we will unify the two approaches for fractal binary images. We will compare the decoding algorithms of the two families. Finally, we will generalize the discussion to continuous-tone images.
Optimality of network coding with buffers

We analyze distributed and packetized implementations of random linear network coding (PNC) with buffers. In these protocols, nodes store received packets to later produce coded packets that reflect this information. We show the optimality of PNC for any buffer size; i.e., we show that PNC performs at least as good as any protocols with the same buffer size. In other words, a multicast task completes at exactly the first time in which in hindsight it was possible to route information from the sources to each receiver individually given the buffer constraint, i.e., that the buffer used at each node never exceeds its buffer size. This shows that PNC, even without any feedback or explicit buffer management, allows to keep minimal buffer sizes while maintaining its optimal performance.
The relative responsiveness of concrete operational seventh grade and college students to science instruction

Numerous persons have suggested that instruction should match the developmental level of the learner. Are “concrete operational” college students developmentally the same as “concrete operational” seventh grade students thus in need of identical instruction? Matched concrete operational seventh grade and college students were given identical classroom instruction in probabilistic and correlational reasoning. The college students performed significantly better on posttest measures which appeared to require greater processing of information while significant differences did not exist on less difficult items. Level of cognitive development, field independence, and fluid intelligence correlated moderately with posttest performance for the seventh grade students. Field independence and fluid intelligence correlated moderately with posttest performance for the college students but not pretest knowledge of specific biological concepts and cognitive level. It was concluded that college students are more responsive to instruction due either to (1) greater amount of experience or (2) greater information processing capacity. Implications for science teaching are discussed.
FROM POPULATION SOURCES TO SIEVES: THE MATRIX ALTERS HOST–PARASITOID SOURCE–SINK STRUCTURE

Field experiments that examine the impact of immigration, emigration, or landscape structure (e.g., the composition of the matrix) on the source–sink dynamics of fragmented populations are scarce. Here, planthoppers (Prokelisia crocea) and egg parasitoids (Anagrus columbi) were released among host-plant patches that varied in structural (caged, isolated, or in a network of other patches) and functional (mudflat matrix that impedes dispersal vs. brome-grass matrix that facilitates dispersal) connectivity. Planthoppers and parasitoids on caged patches exhibited density-dependent growth rates, achieved high equilibrium densities, and rarely went extinct. Therefore, experimental cordgrass patches were classified as population sources. Because access to immigrants did not result in elevated population densities, source populations were not also pseudosinks, i.e., patches whose densities occur above carrying capacity due to high immigration. Planthoppers and parasitoids in open patches in mudflat had dynamics similar to those in caged patches, but went extinct in 4–5 generations in open patches in brome. Brome-embedded patches leaked emigrants at a rate that exceeded the gains from reproduction and immigration; populations of this sort are known as population sieves. For species whose suitable patches are becoming smaller and more isolated as a result of increased habitat fragmentation, emigration losses are likely to become paramount, a condition favoring the formation of population sieves. An increase in the proportion of patches that are sieves is predicted to destabilize regional population dynamics.
Tissue distribution and developmental patterns of NADH‐dependent and ferredoxin‐dependent glutamate synthase activities in maize (Zea mays) kernels

Both NADH-dependent glutamate synthase (NADH-GOGAT, EC 1.4.1.14) and ferredoxin-dependent glutamate synthase (Fd-GOGAT, EC 1.4.7.1) activities were present in the endosperm, embryo, pedicel and pericarp of maize (Zea mays L. var. W64A × A619) kernels. The endosperm contained the highest proportions of each activity on a per tissue basis. In the endosperm, NADH-GOGAT and Fd-GOGAT activities increased 12- and 2.5-fold, respectively, during early zein accumulation. NADH-GOGAT and Fd-GOGAT activities were expressed in the upper, middle and lower portions of the endosperm in a manner that paralleled but preceded zein accumulation. Maize endosperm NADH-GOGAT was purified 159-fold using ammonium sulfate fractionation, anion exchange chromatography and dye-ligand chromatography. Apparent Km values for glutamine, α-ketoglutarate and NADH were 850, 19 and 1 μM, respectively. The results are consistent with endosperm GOGAT functioning to redistribute nitrogen from glutamine, the predominant nitrogenous compound delivered to the endosperm, into other amino acids needed for storage protein synthesis.
Sleep in premature and fullterm infants from 24-hour home recordings☆

Abstract The sleep/wake states of 20 premature and 22 fullterm infants were compared from 24-hour recordings obtained in the home. Using a nonintrusive home monitoring system, they were recorded once a week when they were 1 to 5 weeks postterm. Significant individual differences were found for both groups for all measures obtained. Developmental changes in Active Sleep and Quiet Sleep were found in both groups. Both groups showed more Waking during the day and more of the two sleep states at night. Both groups showed ultradian cyclicity from the first postterm week. The groups did not differ with respect to stability of their sleep patterns over weeks. However, the premature infants had more Quiet Sleep, longer Quiet Sleep bouts, and less Active Sleep, The state differences suggest a more uneven developmental course for states in prematures, and this may reflect compromise in their Central Nervous System status as a consequence of perinatal and early postnatal stress.