cssi/SciSciGPT-SciSciNet huggingface dataset:
The Salmonella typhimurium virulence plasmid encodes a positive regulator of a plasmid-encoded virulence gene.

Abstract The 90-kb virulence plasmid of Salmonella typhimurium is necessary for invasion beyond the Peyer's patches to the mesenteric lymph nodes and spleens of orally inoculated mice. Two Tn5 insertions located on the left side of a previously identified 14-kb virulence region (P. A. Gulig and R. Curtiss III, Infect. Immun. 58:3262-3271, 1988) and mapping 272 bp from each other exhibited opposite effects on splenic infection of mice after oral inoculation. spvR23::Tn5 decreased splenic infection by 1,000-fold, whereas a spv-14::Tn5 mutant outcompeted wild-type S. typhimurium for splenic infection by 27-fold in mice fed mixtures of mutated and wild-type S. typhimurium. spvR23::Tn5 was complemented by a virulence plasmid subclone with an insert sequence encoding only an 891-bp open reading frame specifying a 33,000-molecular-weight protein. The amino acid sequence of this open reading frame had significant homology to members of the LysR family of positive regulatory proteins; thus, the gene was named spvR (salmonella plasmid virulence). To examine the possible regulatory effects of spvR on other virulence genes, we constructed a lacZ operon fusion in a downstream virulence gene, spvB. When spvR subcloned behind the lac promoter was provided on a separate plasmid in trans to the spvB-lacZ operon fusion, transcription of spvB increased 15-fold. spv-14::Tn5, which conferred a competitive advantage to S. typhimurium, increased the expression of a spvR-lacZ operon fusion in cis. spvR is therefore a positive regulator of spvB and an essential virulence gene of S. typhimurium. As opposed to having spvR subcloned behind the lac promoter, the wild-type spvR gene present on the virulence plasmid did not function to positively regulate spvB-lacZ in trans when salmonellae were grown to the log phase in L broth, suggesting that this regulatory system is activated in vivo during infection.
Absorption processes on ice surfaces studied by second-harmonic generation

The surface sensitive laser technique second harmonic generation has been utilized to probe the adsorption of p-tolualdehyde (TA) at the ice/vacuum interface. The non-Langmurian adsorption behavior can be explained by a model in which the TA initially adsorbs as a weakly bound precursor species that is highly mobile and eventually settles to form a more strongly bound species. The relative sticking coefficient for p-tolualdehyde on the ice surface was found to be 40% smaller than that on a NaCl crystal.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Coagulation Abnormalities in Subarachnoid Hemorrhage

Coagulation and fibrinolytic studies were performed in 30 subarachnoid hemorrhage patients and 30 age-matched and sex-matched controls. Systemic abnormalities were detected in the following tests: recalcification time, fibrinogen, partial thromboplastin time, K value of thromboelastogram and euglobulin lysis time. The data suggest that subarachnoid hemorrhage patients with fibrinogen values over 400 mg% have a low probability of survival. Test abnormalities probably reflect tissue damage and/or meningeal reaction to the subarachnoid hemorrhage. Similar abnormalities can be noted in patients with cerebral trauma and in some patients with nonhemorrhagic cerebrovascular disease.1 Our data reveal that subarachnoid hemorrhage patients may exhibit simultaneously evidence suggesting increased coagulability and activation of fibrinolytic mechanisms. Under these circumstances administration of agents to suppress lytic activity might lead to disastrous consequences such as widespread intervascular coagulation (cons...
Sumoylation of Transcription Factor Tec1 Regulates Signaling of Mitogen-Activated Protein Kinase Pathways in Yeast

Tec1 is a transcription factor in the yeast mitogen-activated protein kinase (MAPK) pathway that controls invasive growth. Previously we reported that a fraction of Tec1 protein is sumoylated on residue lysine 54 in normally growing cells. Here we describe regulation and functional consequences of Tec1 sumoylation. We found that activation of Kss1, the MAPK that directly activates Tec1, results in a decrease in Tec1 sumoylation and a concurrent increase of Tec1 transcriptional activity. Consistent with a role of sumoylation in inhibiting Tec1 activity, specifically increasing sumoylation of Tec1 by fusing it to the sumoylating enzyme Ubc9 leads to a dramatic decrease of Tec1 transcriptional activity. Invasive growth is also compromised in Tec1-Ubc9. In contrast, fusing sumoylation-site mutant Tec1, i.e., Tec1K54R, to Ubc9 did not significantly alter transcriptional activation and had a less effect on invasive growth. Taken together, these findings provide evidence for regulated sumoylation as a mechanism to modulate the activity of Tec1 and validate Ubc9 fusion-directed sumoylation as a useful approach for studying protein sumoylation.
Peak coalescence, spontaneous loss of coherence, and quantification of the relative abundances of two species in the plasma regime: Particle-in-cell modeling of fourier transform ion cyclotron resonance mass spectrometry

Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is often limited by space-charge effects. Previously, particle-in-cell (PIC) simulations have been used to understand these effects on FTICR-MS signals. However, none have extended fully into the space-charge dominated (plasma) regime. We use a two-dimensional (2-D) electrostatic PIC code, which facilitates work at very high number densities at modest computational cost to study FTICR-MS in the plasma regime. In our simulation, we have observed peak coalescence and the rapid loss of signal coherence, two common experimental problems. This demonstrates that a 2-D model can simulate these effects. The 2-D code can handle a larger numbers of particles and finer spatial resolution than can currently be addressed by 3-D models. The PIC method naturally takes into account image charge and space charge effects in trapped-ion mass spectrometry. We found we can quantify the relative abundances of two closely spaced (such as 7Be+ and 7Li+) species in the plasma regime even when their peaks have coalesced. We find that the frequency of the coalesced peak shifts linearly according to the relative abundances of these species. Space charge also affects more widely spaced lines. Singly-ionized 7BeH and 7Li have two separate peaks in the plasma regime. Both the frequency and peak area vary nonlinearly with their relative abundances. Under some conditions, the signal exhibited a rapid loss of coherence. We found that this is due to a high order diocotron instability growing in the ion cloud.
Stem Cell Transplantation for Myelodysplastic Syndromes: The Lure of a Cure

Allogeneic stem cell transplantation is the only known curative therapy for myelodysplastic syndromes. However, the morbidity and mortality from this approach is high, especially in a population that tends to be elderly with comorbid conditions. In order to achieve a good outcome, the key is wise choice of the patient to undergo transplantation and appropriate timing of the therapy. Furthermore, consideration should be given to choosing whether the regimen should be fully myeloablative or reduced-intensity and whether marrow, peripheral-blood stem cells, or cord blood should be chosen for stem cell replacement. This article reviews the history of transplantation for this indication and the newer data driving decisions regarding the type of transplant and the optimal timing for best results.
Early Head Start: Investigations, insights, and promise

Les auteurs passent en revue la portee des recherches resumees dans ce numero special, y compris les activites qui contribuent a des partenariats couronnes de succes entre les universites et les communautes. Les promesses du Early Head Start (le Early Head Start etant un programme de prevention et d'aide gouvernementale a la petite enfance defavorisee aux Etats-Unis d'Amerique) seront tenues si les chercheurs mettent l'accent sur les moderateurs et les mediateurs des effets du programme, sur la qualite du programme et sur les liens entre le Early Head Start et les resources communautaires. Les facteurs cles qui doivent etre pris en compte dans l'analyse des resultats du programme EHS comportent l'evaluation des transitions des enfants allant a la petite maternelle, a la grande maternelle, et a l'ecole elementaire; les changements dans les resources personnelles et sociales de la famille; le role des peres dans le developpement de leur petit enfant, et l'impact du bilinguisme familial.
Theory of NMR field-gradient spectroscopy for anomalous diffusion in fractal networks

Abstract Theoretical predictions for the spin-echo amplitude attenuation in a field-gradient NMR experiment in a porous medium are presented for both continuous and pulsed spectroscopy. The diffusion is modelled by a random walk process on a fractal network and should correspond to observations in well-characterised real materials.
Regulation of cAMP‐specific phosphodiesterases type 4B and 4D (PDE4) splice variants by cAMP signaling in primary cortical neurons

This study examined the regulation of all known phosphodiesterase (PDE) type PDE4A, PDE4B and PDE4D splice variants in cortical neurons by cAMP signaling. Treatment with dibutyryl-cAMP (db-cAMP) caused the induction of two of the known splice variants, PDE4B2 and PDE4D1/PDE4D2. Although the splice variants PDE4A1, PDE4A5/PDE4A10, PDE4B3, PDE4B1, PDE4D3 and PDE4D4 were present in cortical neurons, their mRNA was not regulated at the transcriptional level by db-cAMP. To assess the increase in PDE4B2 and PDE4D1/D2 mRNA expression, the promoters containing these genes were characterized. Transcription from both promoters was stimulated by db-cAMP. Because chronic antidepressant treatment increases PDE4B, and not PDE4D, mRNA expression, we focused on the regulation of the PDE4B2 promoter by cAMP and CREB. Dominant negative mutants of CREB suppressed PDE4B2 promoter activity and a constitutively active form of CREB robustly stimulated it. These data demonstrate that in cortical neurons, a short PDE4B2 intronic promoter is regulated by CREB, confers cAMP responsitivity and directs PDE4B2 mRNA and protein expression.
Development and dynamics of regional specialization within the syncytial epidermis of the rat tapeworm, Hymenolepis diminuta.

The epidermis of the tapewormHymenolepis diminuta is a highly organized syncytium, composed of an outer layer of continuous cytoplasm, or ectocytoplasm, and an inner layer of nucleated cell bodies, or perikarya. The perikarya are in direct cytoplasmic continuity with the ectocytoplasm via narrow plasmalemma-bound bridges called internuncial process. Although distinct structural and functional differences are apparent between ectocytoplasm and perikarya, all of the perikarya along the body of the cestode are morphologically similar, as are all regions of ectocytoplasm. However, immunocytochemically distinct subpopulations of perikarya and regionally defined areas of ectocytoplasm were identified along the tapeworm strobila by the use of monoclonal antibodies raised against a preparation of isolated tegument. The different types of perikarya and the regionally specialized areas of ectocytoplasm were organized in a topographically precise manner along the body of the parasite. Examination of labeling patterns after colchicine treatment suggests that different types of perikarya are specialized for biosynthesis of specific tegumental molecules and for turnover or recycling of tegumental material. Furthermore, it appears that a 52 kDa polypeptide synthesized by one population of perikarya is transported through the syncytium and ultimately resorbed by a different population of tegumental perikarya. These data suggest that the syncytial epidermis of parasitic platyhelminthes exhibits a more complex organization of function than previously appreciated.
Caloric intake and expenditure of obese boys.

Caloric intake and expenditure of children in four families were assessed by nonparticipant observations of family dinners and school lunches. In each family there were one obese boy and one nonobese brother whose ages were within two years of each other. For family dinners the nonobese brother served as a control; for school lunches, a nonobese peer served as a control. The obese boys consumed more calories (766±290) than did their nonobese brothers at dinner (504±183) and far more (907±217) than their nonobese peers at lunch (500±386). The obese boys also ate faste (65.7±37.0 kcal/minute) than their brothers at dinner (31.7±13.8 kcal/minute) and far faster (103.5±40.9 kcal/minute) than their nonobese peers at lunch (46.2±22.5 kcal/minute). Time-sampled activity assessments showed the obese boys far less active than their controls inside the home, slightly less active outside the home, and equally active at school. When these activity values were converted into energy expenditure by measurement of oxygen consumption, obese boys expended more calories in moving than did their controls; as a results, there was no difference in energy expenditure between obese and nonobese boys at home and greater energy expenditure outside the home and at school. Increased intake, thus, and not decreased caloric output maintained the obesity of these four boys. In this respect, obesity in childhood may differ from obesity in adult life.
NMR studies of methylenebispyridinium derivatives

The methylene proton chemical shifts of the system appear to be affected by the synergistic interactions of a combination of various effects. Although it is difficult to single out the origin, transmission and magnitude of these effects, the synergistic interactions pervade the molecule, causing a net displacement of the chemical shifts. The substituent-produced chemical shifts show a clear trend in their dependence on the nature of the substituents and the Hammett parameters. Strong through-conjugation between the aromatic nitrogen and resonance donor substituents in the para-position is observed.
Why is CMP-ketodeoxyoctonate highly unstable?

CMP-ketodeoxyoctonate (CMP-KDO) and analogs, including CMP-5-deoxy-5-fluoro-KDO, CMP-5-deoxy-KDO, and CMP-5-epi-KDO, were prepared from CTP and the corresponding KDO sugars catalyzed by CMP-KDO syn...
Linguistic Purism in Cuzco, Peru: A Historical Perspective.

RESUMENPurismo linguistico en Cuzco, Peru: Perspectiva historicaEn Cuzco, Peru, un grupo de intelectuales mestizos afirma que Qhpaj'simi es el quechua que usaron los nobles incas hace muchos siglos y por lo tanto es la forma mas pura de la lengua. Con base en esta premisa se establece una jerarquia social en la cual el uso de la "lengua imperial" es el marcador que separa a sus usuarios de la gente comun, usuarios del runa simi. Puesto que las actitudes de purismo linguistico estan siempre ligadas a la idiosincracia cultural, las actitudes puristas en el Cuzco se estudian en el contexto de la historia del Indigenismo y su papel en la construction de la identidad regional.RESUMOLingva purismo en Cuzco, Peruo: Historia perspektivoEn Cuzco, Peruo, grupo de mestizaj intelektuloj pretendas, ke Qhpaj'simi konsistigas la keĉuan lingvon uzatan antaŭ jarcentoj de la inkaa nobelaro kaj tial estas la plej pura formo de la lingvo.Surbaze de tiu premiso, socia hierarkio establiĝis, tiel ke utiligo de tiu "imperia lingvo" farigis la marko apartiganta giajn utiligantojn disde la ordinaraj homoj, parolantoj de la runa simi. Ĉar sintenoj pri lingva purismo ciam ligiĝas al kulturaj apartaĵoj, la aŭtoro kuntekstigas la purismajn sintenojn de Cuzco en la historion de indiĝenismo kaj ties rolo en konstruado de regiona identeco.
COMPARISON OF HYPOTHALAMUS PITUITARY ADRENAL AXIS SUPPRESSION (HPAS) FROM TOPICAL STEROIDS BY STANDARD ENDOCRINE FUNCTION TESTING AND GAS CHROMATOGRAPHY MASS SPECTFOMETRY(GCMS)

COMPARISON OF HYPOTHALAMUS PITUITARY ADRENAL AXIS SUPPRESSION (HPAS) FROM TOPICAL STEROIDS BY STANDARD ENDOCRINE FUNCTION TESTING AND GAS CHROMATOGRAPHY MASS SPECTFOMETRY(GCMS)
A Simple Furnace for Obtaining High Temperature Raman Spectra

We have recently studied the Raman spectra of several fused salt systems using laser excitation. The materials to be studied in these experiments were sealed in small (4 to 5 mm o.d. × 5 cm long) glass or quartz tubes under vacuum. The sample tubes were then wrapped with lengths of nichrome or platinum wire spaced widely enough to allow passage of light between the turns. To observe the Raman spectra, a sample tube was clamped in the spectrometer in a position such that the laser beam penetrated the sample at right angles to the tube axis. The scattered light was collected at right angles to both the sample tube and the laser beam. To provide adequate temperature control, the heating wire was connected to several variacs in series.
High-efficiency molecular counting in solution: single-molecule detection in electrodynamically focused microdroplet streams.

We report fluorescence detection of individual rhodamine 6G molecules using a linear quadrupole to focus streams of microdroplets through the waist of a counterpropagating cw Ar+ laser. Since the terminal velocity scales as the square of the droplet diameter, the droplet−laser interaction time was “tunable” between 5 and 200 ms by using water samples spiked with a small, variable (2−5% v/v) amount of glycerol. Fluorescence bursts from droplets containing single molecules were clearly distinguished from the blanks in real time with an average signal-to-noise ratio of about 10, limited primarily by photobleaching and droplet size fluctuations ( 99% confidence) were obtained for 100 and 15 fM rhodamine 6G solutions, in good agreement with detailed theoretical c...
Sex differences and hormonal influences on response to mechanical pressure pain in humans.

Abstract Previous studies have demonstrated that sex differences in pain responsivity can be detected using various models of experimentally induced pain. The present study employed the mechanical pressure test in order to examine potential differences in pain report among men, normally menstruating women (NMW), and women taking monophasic oral contraceptives (OCW). Testing occurred during 5 phases of the menstrual cycle (menstrual, follicular, ovulatory, luteal, and late luteal) and all participants completed 10 sessions (2 sessions per phase). Menstrual-cycle phase was estimated for OCW based on their first day of menses. Men were tested at time points that roughly corresponded to the intervals during which the different phases occurred in NMW. During the mechanical pressure test, 4 different weights were placed on the fingers, one at a time, and ratings of pain were recorded for 30 seconds. The statistical decision-making model and a forced-choice procedure were used to analyze the response data. Two variables, based on signal detection theory, were thus generated: P(A), a measure of sensory pain, and B, a measure of response bias. P(A) is believed to be a measure of pain sensitivity while B measures stoicism. NMW tended to report lower P(A) values, indicating reduced ability to discriminate among different stimulus intensities, during the menstrual and late luteal phases compared to the luteal phase. OCW reported lower B values, indicating less stoicism, during the menstrual compared to the follicular and ovulatory phases. Men tended to have significantly lower B values than OCW, but not NMW. These results demonstrate subtle menstrual-cycle effects in NMW and OCW. Sex differences were few, with more group differences and trends emerging between OCW and men, as opposed to men and NMW. Perspective The lack of consistent differences between men and NMW underscores the subtle impact of sex and hormonal changes in pain report. In addition, the data obtained in NMW support the notion that changes in hormone levels during the menstrual cycle can lead to changes in pain responsivity as NMW had trends for better discrimination in menstrual phases when estradiol levels were highest.
Role of Glomerular Filtration Rate in the Impaired Sodium and Water Excretion of Patients With the Nephrotic Syndrome

Hemodynamic and hormonal factors were monitored in nine patients with nephrotic syndrome who were evaluated relative to their capacity to excrete a 20-mL/kg water load (normal greater than 80%). In five "nonexcretor" patients (37% of water load excreted in five hours), as compared to four normal excretors (105% of water load excreted in five hours; P less than .01 v nonexcretors), neither BP (131/88 v 119/79 mm Hg), pulse (74 v 77 beats/min), cardiac index (3.7 v 3.1 L/min/m2), pulmonary wedge pressure (9.3 v 7.3 mm Hg), systemic vascular resistance (1537 v 1254 dynes-sec-cm-5), nor plasma volume (41.3 v 40.1 mL/kg) were different. Similarly, plasma renin activity (2.6 v 3.7 ng/mL/h), plasma aldosterone (12 v 10.9 ng/dL), and plasma norepinephrine (403 v 312 pg/mL) were not different between nonexcretor v excretor patients with nephrotic syndrome. Plasma vasopressin concentrations were also similar both before (3.1 +/- 0.8 v 2.4 +/- 1.2 pg/mL) and during the water load (0.9 +/- 0.3 v 1.0 +/- 0.4 pg/mL). Inulin clearances, however, were lower in the nonexcretor v the excretor nephrotic patients (37 v 78 mL/min/1.73 m2; P less than .02) and correlated with water excretion (r = .68; P less than .05). Head-out water immersion increased sodium (40 to 110 microEq/min; P less than .01) and water excretion (37% to 82%; P less than .025) in the nonexcretors; the improvement correlated with the increase in inulin clearance during immersion (r = .70; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Timidity and fearfulness of laboratory mice: an illustration of problems in animal temperament.

Two inbred strains of mice and their derived generations were tested for home cage emergence and open field behavior under two levels of environmental stimulation. The least timid (fast emerging) genotype was found to be most fearful (high defecation in open field), whereas the most timid strain was least fearful. In addition, exposure to a loud noise during testing consistently resulted in a decrease in emergence latency and an increase in open field defecation, i.e., environmental stimulation sufficient to decrease timidity increased fearfulness. This apparent paradox illustrates a major problem in interspecific behavioral comparisons;a priori analogic reasoning from human theory to animal model, without regard for the meaning of constructs in the behavioral organization and evolutionary adaptation of the species studied, often results in rigorous investigation of operationally defined behavioral constructs devoid of meaning.
Reflex hypotension due regional activation of left ventricular mechanoreceptors to explain the hypotension noted in clinical myocardial ischaemia or reperfusion

To determine if regional increases in myocardial contractility, as may occur clinically in angina pectoris, myocardial infarction, or coronary thrombolysis, can initiate the reflex hypotension that sometimes accompanies these conditions, regional injections of positive inotropic agents were made into 32(3)% of the left ventricular myocardium in seven pneumonectomised dogs on total cardiac bypass. The coronary and systemic circulations were isolated and perfused separately. The systemic circulation was perfused at a constant rate so that changes in systemic pressure reflected changes in resistance. Regional injections of doses from 0.0001 to 1.0 μg noradrenaline in a 0.1 ml volume appreciably increased regional contractility, detected visually and by strain gauge arches, whereas global contractility (left ventricular peak dP/dt) was increased much less. This caused a fall in the systemic pressure (resistance) of 14(2)% below the control value of 78(5)mm Hg, at the largest dose. The decreases in resistance were abolished by bilateral vagotomy, proving their reflex nature. The smaller (0.0001–0.01 μg) doses of noradrenaline and the smallest (0.25 μg) dose of veratridine increased regional contractility almost without increasing global contractility, indicating that the increase in regional contractility was the major cause of the reflex decrease in systemic resistance. In one animal a decrease in contractility in a control myocardial region occurred simultaneously with the experimentally produced increase in regional left ventricular contractility. This decrease may be analogous to the increase in contractility in the non-ischaemic left ventricular myocardium that occurs simultaneously with the decrease in contractility in the ischaemic region in clinical or experimental myocardial infarction. Left ventricular mechanoreceptors in the region with increased contractility probably initiate the reflex hypotension that sometimes occurs in both circumstances. Thus in angina pectoris or acute myocardial infarction the reflex hypotension probably originates in the hyperactive non-ischaemic myocardial region, whereas in coronary arterial thrombolysis it probably originates in the newly reperfused, formerly ischaemic, region.
CHAINED VERSUS POST‐STRATIFICATION EQUATING IN A LINEAR CONTEXT: AN EVALUATION USING EMPIRICAL DATA

This study used real data to construct testing conditions for comparing results of chained linear, Tucker, and Levine-observed score equatings. The comparisons were made under conditions where the new- and old-form samples were similar in ability and when they differed in ability. The length of the anchor test was also varied to enable examination of its effect on the three different equating methods. Two tests were used in the study, and the three equating methods were compared to a criterion equating to obtain estimates of random equating error, bias, and root mean squared error (RMSE). Results showed that for most of the conditions studied, chained linear score equating produced fairly good equating results in terms of low bias and RMSE. In some conditions, Levine-observed score equating also produced low bias and RMSE. Although the Tucker method always produced the lowest random equating error, it produced a larger bias and RMSE than either of the other equating methods. Based on these results, it is recommended that either chained linear or Levine score equating be used when new- and old-form samples differ in ability and/or when the anchor-to-total correlation is not very high.
Logical and illogical errors made by apes and children on a cognitive task

The purpose of this study was to analyse changes in errors made by juvenile chimpanzees, mentally retarded human children, and human children of normal intelligence who were tested on a non-verbal, Piagetian-type multiple classification task. On this task the subjects were required to select the correct object from the response tray and place it inside the empty cell of the stimulus matrix that was formed by combining two different colors with two different forms. The data were analysed to determine the degree to which absolute error rate and patterns of logical and illogical errors, that occurred on the first and second trials of each problem, influenced the multiple classification performance of non-human and human primates. Logical errors were operationally defined as the selection of objects which had one or two stimulus dimensions incorrect on the first trial, and the selection of objects which had one or two stimulus dimensions correct on the second trial. Illogical errors were operationally defined as the selection of objects which only had one stimulus dimension correct on the first trial, and the selection of objects which had both stimulus dimensions incorrect on the second trial. It was found that there was an inverse relationship between absolute error rate and the selection of objects which were correct on both color and form on the first trial. The proportion of logical errors remained constant at about 80% for all groups tested, save for the normal children who had an absolute and relative error rate that approached a value of zero for the last part of testing. These results suggest that while absolute error rate may be influenced by the specific characteristics of the stimulus items used, logical errors indicate that a similar cognitive mechanism may permit non-human and human primates to utilize the two stimulus dimensions of color and form to solve a series of unique multiple classification problems. The implication of these results to the language-cognition
Receiver structures for underwater acoustical communications using chirp slope keying

This paper presents several receiver structures for Chirp Slope Keying (CSK), a digital broadband modulation scheme we propose to use for underwater acoustical communications. In its simplest form, the binary information modulates the slope of a linear chirp, with up-chirps representing ones and down-chirps representing zeros. A time-domain receiver and a novel time-frequency receiver structure based on the Wigner distribution and the Radon Transform are discussed and evaluated in terms of the probability of error versus Signal-to-Noise (SNR) performance. Simulation results and plots are presented for the Additive White Gaussian Noise (AWGN) channel. Results show that if the detector at the receiver operates directly on the slope of the received signal, performance is improved at the expense of computational complexity.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
NOSE TALK: Pheromones and Animal Behaviour; Communication by Smell and Taste

By Tristram D. Wyatt Cambridge University Press pp. 408. ISBN 052148068X (hbk)/0521485266 (pbk) $100 (hbk)/$40 (pbk) ![Figure][1] Wyatt's book Pheromones and Animal Behaviour is an excellently written account of the important, but often
Biomass and carbon data from blue oaks in a California oak savanna

Stem circumference at breast height (1.4 m above ground), tree height, distance from the ground to the base of the crown, and crown radii from the stem to the average drip line were measured for fourteen blue oak (Quercus douglasii) trees from a California site. The trees were felled, and we determined mass of stems, branches, twigs, and foliage; and analyzed carbon and nitrogen in branch and stem (0.44% N, 45.85% C) and leaf (2.13% N, 45.11% C) samples. Equations estimating biomass from diameter at breast height (dbh) or diameter at root collar (drc) were developed through regression. We applied our equations to blue oak data from the U.S. Department of Agriculture, Forest Service, Forest Inventory and Analysis Program (FIA) database. Our biomass and carbon estimates were generally comparable to but exceeded FIA's predictions by about 15% and 7%, respectively.
Effect of physical exercise prelabyrinthectomy on locomotor balance compensation in the squirrel monkey

This study examines the effectiveness of physical exercise, during a prepathology state, on locomotor balance compensation after subsequent unilateral labyrinthectomy in squirrel monkeys. An experimental group underwent 3 hr. of daily running exercise on a treadmill for 3 mo. prior to the surgery, whereas a control group was not exercised. Postoperatively, the locomotor balance function of both groups was tested for 3 mo. There was no significant difference in gait deviation counts in the acute phase of compensation. However, in the chronic compensation maintenance phase, the number of gait deviation counts was fewer in the exercise group, which showed significantly better performance stability.
On the biochemical similarities of ascorbic acid and interferon.

Abstract The anti-viral effects of ascorbic acid and interferon are proposed to result from the peroxy radical mediated biosynthesis of prostaglandins and from the direct attack of free radical species on unsaturated lipids in the cell membrane. These processes are proposed to lead to changes in fluidity of the host cell membrane which inhibit the fusogenicity of the attacking virus.
Two-dimensional robust spectrum estimation

Robust estimation is studied of two-dimensional (2-D) power spectra of signals which are adequately represented by Gaussian random field models but for which there are imperfect observations. Two situations of particular interest occur when the contaminating noise is additive and when the contaminating noise appears in the innovations. In these cases, the observed data are not Gaussian and conventional procedures are no longer efficient. To estimate the parameters of the signal model from the contaminated data, two procedures are described which were originally proposed for estimation of scale and location from independent data and adapted to one-dimensional autoregression parameter estimation by previous researchers. The first algorithm is a robustification of least squares and equivalent to an iterated weighted least-squares problem where the weights are data-dependent. The second algorithm is an iterative procedure known as a filter cleaner. Experiments using the robust procedures with synthetic data are reported and the results compared to a conventional method of model-based spectrum estimation. >
A User Interaction Model for NFC Enabled Applications

Near field communication (NFC) is a short-range wireless protocol that allows users to connect devices and access content and services by simply holding enabled devices near each other. This paper introduces a user interaction model for NFC enabled applications. Our model specifies that enabled devices take on the properties and context of the objects required in the interaction. This transformation leverages the existing knowledge users have about certain objects and thus can support a number of different applications tied together with simple, intuitive and repeatable interactions. In this paper, we present an overview of the model and the system we have implemented to enable evaluation. We also detail some research challenges we are pursuing
Categorization and analysis of text in computer mediated communication archives using visualization

Digital libraries (DLs) for online discourse contain large amounts of valuable information that is difficult to navigate and analyze. Visualization systems developed to facilitate improved CMC archive analysis and navigation primarily focus on interaction information, with little emphasis on textual content. In this paper we present a system that provides DL exploration services such as visualization, categorization, and analysis for CMC text. The system incorporates an extended feature set comprised of stylistic, topical, and sentiment related features to enable richer content representation. The system also includes the Ink Blot technique which utilizes decision tree models and text overlay to visualize CMC messages. Ink Blots can be used for text categorization and analysis across forums, authors, threads, messages, and over time. The proposed system's analysis capabilities were evaluated with a series of examples and a qualitative user study. Empirical categorization experiments comparing the Ink Blot technique against a benchmark support vector machine classifier were also conducted. The results demonstrated the efficacy of the Ink Blot technique for text categorization and also highlighted the effectiveness of the extended feature set for improved text categorization.
A Practical Scheme for the GC Analysis of Pyridine Hydrodenitrogenation Reaction Products

Abstract This paper outlines a fast and simple GC technique for on-line analysis of the products of hydrodenitrogenation of pyridine. Two separate columns, viz., Carbowax 1500/Chromosorb W, and n-Octane/Porasil C, which are sequenced with a 10-port sampling valve are used for this purpose. The 10-port valve is maneuvered so as to accomplish the separation of C1-C5 paraffins, C3-C5 olefins and pyridines in a single injection of sample.
M2 macrophages promote beta-cell proliferation by up-regulation of SMAD7.

Determination of signaling pathways that regulate beta-cell replication is critical for beta-cell therapy. Here, we show that blocking pancreatic macrophage infiltration after pancreatic duct ligation (PDL) completely inhibits beta-cell proliferation. The TGFβ superfamily signaling inhibitor SMAD7 was significantly up-regulated in beta cells after PDL. Beta cells failed to proliferate in response to PDL in beta-cell–specific SMAD7 mutant mice. Forced expression of SMAD7 in beta cells by itself was sufficient to promote beta-cell proliferation in vivo. M2, rather than M1 macrophages, seem to be the inducers of SMAD7-mediated beta-cell proliferation. M2 macrophages not only release TGFβ1 to directly induce up-regulation of SMAD7 in beta cells but also release EGF to activate EGF receptor signaling that inhibits TGFβ1-activated SMAD2 nuclear translocation, resulting in TGFβ signaling inhibition. SMAD7 promotes beta-cell proliferation by increasing CyclinD1 and CyclinD2, and by inducing nuclear exclusion of p27. Our study thus reveals a molecular pathway to potentially increase beta-cell mass through enhanced SMAD7 activity induced by extracellular stimuli.
Bone Formation During Distraction Osteogenesis Is Dependent on Both VEGFR1 and VEGFR2 Signaling

Introduction: Distraction osteogenesis (DO) is characterized by the induction of highly vascularized new bone formation through an intramembranous process largely devoid of the formation of cartilage. Materials and Methods: To test the hypothesis that DO is strictly dependent on vascualrization, we inhibited vascular endothelial growth factor (VEGF) activity by antibody blockade of both receptors VEGFR1 (Flt-1) and VEGFR2 (Flk-1) or only VEGFR2 (Flk-1) in a previously developed murine tibia DO model. During normal DO, VEGFR1 (Flt-1), VEGFR2 (Flk-1), VEGFR3 (Flt4) and all four VEGF ligand (A, B, C, and D) mRNAs are induced. Results: The expression of mRNA for the receptors generally paralleled those of the ligands during the period of active distraction. Bone formation, as assessed by μCT, showed a significant decrease with the double antibody treatment and a smaller decrease with single antibody treatment. Vessel volume, number, and connectivity showed progressive and significant inhibition in all of these of parameters between the single and double antibody blockade. Molecular analysis showed significant inhibition in skeletal cell development with the single and double antibody blockade of both VEGFR1 and 2. Interestingly, the single antibody treatment led to selective early development of chondrogenesis, whereas the double antibody treatment led to a failure of both osteogenesis and chondrogenesis. Conclusions: Both VEGFR1 and VEGFR2 are functionally essential in blood vessel and bone formation during DO and are needed to promote osteogenic over chondrogenic lineage progression.
The association of malrotation and Hirschsprung's disease

Malrotation and Hirschsprung's disease are common gastrointestinal abnormalities in neonates and infants. Four patients with the association of malrotation and Hirschsprung's disease are reported. A delay in diagnosis may be complicated by midgut volvulus or enterocolitis. The diagnostic and therapeutic implications of this important association are discussed.
Distant upstream regulatory sequences control the level of expression of the am (GDH) locus of Neurospora crassa

We have constructed deletions in the 5′ non-coding sequences of the cloned Neurospora crassa am gene. Vectors with a truncated fragment of the am gene were used in transformation experiments to introduce the deletions into the chromosome by homologous recombination. Analysis of glutamate dehydrogenase (GDH) expression by enzyme assay and immunoblots, as well as Northern and dot blots of poly (A)+ RNA, in the deletion strains indicates that there are two upstream regulatory sequences that control the level of gene expression. The closer of these two elements (URSamα) is at approximately 1.4 kb upstream of the transcriptional start site. The second elements (URSamβ) is located between 2.1 and 3.2 kb upstream of the transcription start site. Deletion of either of these two elements reduces am expression to about 50% of the wild-type level. Deletion of both elements reduce am expression to from 5–16% of the wild-type level. Deletion of 1.1 kb of sequence just downstream of URSamα, which brings this element to within 300 bp of the transcription start site, had no effect on am expression. Likewise, deletion of 3.5 kb of sequence upstream of URSamβ had no effect on expression. None of these deletions had any effect on the expression of usg-1, a gene of unknown function that is transcribed in the same direction as the am gene, and which terminates about 3.5 kb upstream of the URSamβ element.
Complex Segregation Analysis on Sib-Pairs Data

Using sib-pairs and parent-pairs data, a quantitative trait can be tested for the existence of a major locus under the mixed model of Morton and MacLean (1974). The basic idea is to obtain the two conditional likelihoods for sib-pair differences and parent-pair differences provided that it is known which sib-pairs or parent-pairs have the same effect at the major locus. Two conditions are introduced to obtain two recursive computer algorithms that distinguish the sib-pairs or parent-pairs having the same effect at the major locus. This method has the advantage of reducing complicated computations involving maximum likelihood estimates from nuclear families. A simulation experiment is performed to illustrate the method and its results are discussed.
A photometric coagulometer.

The reduction of transmitted light at 650 nm caused by scattering from fibrin polymers as they develop in a clotting plasma sample has proven effective for following the course of the coagulation. An instrument designed on this principle and using entirely solid-state electronics has yielded clotting time reproducible to within ±15%, and has enabled discrimination between induction and fibrin polymerisation times. Data on vapour-deposited and sputtered films of polytetrafluorethylene, under study as thromboresistant surfaces, are presented to illustrate the uses of this coagulometer.
Use of the latissimus dorsi flap in head and neck reconstructive microsurgery.

Reconstructive surgery of the head and neck has particularly benefited from the rapid developments in microsurgery. Resection of tumours from the head and neck which are associated with serious physical and psychological problems, or which often require multiple reconstructive procedures, can now be performed as a single-stage procedure with good oncological and functional results. The present series reports on the treatment of 12 primary or recurrent malignant tumours of the head and neck using the latissimus dorsi musculocutaneous free flap. Complications consisted of two venous thromboses which required revision of the anastomoses. The oncological and functional results were good, while the aesthetic outcome was fair. We conclude that the latissimus dorsi muscle or musculocutaneous free flap is the method of choice to repair wide defects of the head and neck following the resection of malignant tumours. © 1994 Wiley-Liss, Inc.
Mammary Blood Flow and Endocrine Changes During Parturition in the Ewe

The temporal relationship between changes in mammary blood flow (MBF) and changes in the concentrations of plasma prolactin, progesterone, estradiol-17β, and cortisol, was examined in chronic sheep preparations undergoing spontaneous labor (Group I) or labor induced by an infusion of dexamethasone (1 mg/24 h) to the fetus (Group II). In Group I, an increase in prolactin (45 to 489 ng/ml), a decrease in progesterone (15 to 4 ng/ml), and an increase in MBF (97 to 365 ml/min) occurred at about the same time, whereas increases in estradiol-17β (80 to 211 pg/ml) and cortisol (9 to 39 ng/ml) followed the change in MBF. A similar pattern of changes in MBF and hormonal concentrations occurred over a shorter time period when premature labor was induced in the animals in Group II. These findings suggest that changes in plasma prolactin and progesterone concentrations play an important role in the regulation of MBF at the time of parturition. (Endocrinology 98: 748, 1976)
Cobra polypeptide cytotoxin I and marine worm polypeptide cytotoxin A-IV are potent and selective inhibitors of phospholipid-sensitive Ca2+-dependent protein kinase

The effects of a number of polypeptide cytotoxins and neurotoxins on various protein kinases were examined. It was found that cobra cytotoxin I and marine worm cytotoxin A-IV effectively and specifically inhibited phospholipid-sensitive Ca2+-dependent protein kinase (PL-Ca-PK) relative to myosin light chain kinase and cyclic nucleotide-dependent protein kinases. Inhibition of PL-Ca-PK by these cytotoxins could be overcome by phosphatidylserine. Neurotoxins, in comparison, were much less effective inhibitors. The present findings indicated that these polypeptide cytotoxins, unlike other agents reported to date, were selective inhibitors of PL-Ca-PK and could be used to differentiate Ca2+-dependent events regulated by phospholipid or calmodulin.
Application of the Aza-Achmatowicz Oxidative Rearrangement for the Stereoselective Synthesis of the Cassia and Prosopis Alkaloid Family

cis-2-Methyl-6-substituted piperidin-3-ol alkaloids of the Cassia and Prosopis species are readily prepared by a combination of an aza-Achmatowicz oxidative rearrangement and dihydropyridone reduction followed by a stereoselective allylsilane addition to a N-sulfonyliminium ion. The stereochemical outcome of the reduction reaction can be attributed to steric hindrance between the pseudoaxially oriented 2,6-substituents and the equatorially approaching hydride reagent which explains the exclusive formation of the cis-alcohol by axial approach of the hydride. The unsaturation present in the (E)-methyl-pent-3-enoate side chain was removed by catalytic reduction, and the remaining ester group was converted to the corresponding Weinreb's amide. This key intermediate was utilized for the synthesis of azimic acid, deoxocassine, cassine, and spicigerine. The facile preparation of (S)-N-tosylamidofuran 16 and its conversion to the chiral Achmatowicz oxidation product 18 provide a formal chiral synthesis of these a...
Microstructural Engineering of Hydroxyapatite Membranes to Enhance Proton Conductivity

A new approach to enhancing proton conductivity of ceramics is demonstrated by aligning proton conductive pathways and eliminating resistive grain boundaries. Hydroxyapatite (HAP) membranes are synthesized by multistage crystallization onto palladium. The synthesis involves three steps: electrochemical deposition of HAP seeds, secondary hydrothermal crystallization onto the seed layer to promote c-axis growth normal to the substrate, and tertiary hydrothermal crystallization to promote a-axis growth to fill the gaps between the aligned crystals. The c-axis alignment with crystal domains spanning the membrane thickness significantly enhances proton conduction since protons are primarily transported along the c-axes of HAP crystals. The novel HAP membranes display proton conductivity almost four orders of magnitude higher than traditional sintered HAP ceramics. The HAP membranes on palladium hydrogen membrane substrates hold promise for use in intermediate-temperature fuel cells, chemical sensors, and other devices. The synthesis approach presented may also be applied to other ion-conducting membrane materials to enhance transport properties.