cssi/SciSciGPT-SciSciNet huggingface dataset:
New Methods for Chemical Protein Synthesis

Chemical protein synthesis is a useful tool to generate pure proteins which are otherwise difficult to obtain in sufficient amounts for structure and property analysis. Additionally, because of the precise and flexible nature of chemical synthesis, it allows for controllable variation of protein sequences, which is valuable for understanding the relationships between protein structure and function. Despite the usefulness of chemical protein synthesis, it has not been widely adopted as a tool for protein characterization, mainly because of the lack of general and efficient methods for the preparation and coupling of peptide fragments and for the folding of polypeptide chains. To address these issues, many new methods have recently been developed in the areas of solid-phase peptide synthesis, peptide fragment assembly, and protein folding. Here we review these recent technological advances and highlight the gaps needing to be addressed in future research.
Visual motion induces synchronous oscillations in turtle visual cortex

Abstract In mammalian brains, multielectrode recordings during sensory stimulation have revealed oscillations in different cortical areas that are transiently synchronous. These synchronizations have been hypothesized to support integration of sensory information or represent the operation of attentional mechanisms, but their stimulus requirements and prevalence are still unclear. Here I report an analogous synchronization in a reptilian cortex induced by moving visual stimuli. The synchronization, as measured by the coherence function, applies to spindle-like 20-Hz oscillations recorded with multiple electrodes implanted in the dorsal cortex and the dorsal ventricular ridge of the pond turtle. Additionally, widespread increases in coherence are observed in the 1- to 2-Hz band, and widespread decreases in coherence are seen in the 10- and 30- to 45-Hz bands. The 20-Hz oscillations induced by the moving bar or more natural stimuli are nonstationary and can be sustained for seconds. Early reptile studies may have interpreted similar spindles as electroencephalogram correlates of arousal; however, the absence of these spindles during arousing stimuli in the dark suggests a more specific role in visual processing. Thus, visually induced synchronous oscillations are not unique to the mammalian cortex but also occur in the visual area of the primitive three-layered cortex of reptiles.
Reply to Commentators

Professor Kitcher worries about the theory of veritistic value (V-value) advanced in KSW. His worry is that the theory gives no fully general way of measuring (fundamental) V-value, and therefore the project of assessing candidate practices according to their generation of V-value can't get started. KSW's account of V-value makes some appeal to interest, but it does not make sufficiently extensive appeal to interests, Kitcher argues, to yield clear preferences for certain practices over others. Kitcher considers a subject who is interested in three propositions, P, Q, and R, and supposes that one practice does veritistic good with respect to P while a second does similar veritistic good with respect to Q and R. If there were a weighting of interests, one might say which of these practices is preferable to the other. But in the absence of any such weighting, it is impossible to say which is preferable. In addition, he points out, we are often interested not in the epistemic consequences for any particular individual, but in the epistemic consequences for many people. Thus, V-value should not be a function of a single person's interest but of many people's interests. What we need, then, is a collective analogue of (individual) V-value; but no such collective analogue is presented. The sorts of problems Kitcher raises did indeed worry me in writing KSW, and I agree that they were not satisfactorily resolved.' However, some of the problems are not quite as serious as Kitcher suggests. Kitcher is right that if there is no determinate way to measure fundamental V-value, the project of
Percutaneous CT-guided Pulmonary Fiducial Marker Placement for Small Lesions in High-Risk Patients: Technical Considerations, Challenges, and Complications

FBCT, Ref-DTS-AIP, Ref-DTS-4DCT-Phase and Ref-DTS-4DCT-Amp with OBI-DTS are 5.62mm, 1.56mm, 1.22mm, and 1.20mm, respectively. In scenario 4, the corresponding errors are 4.46mm, 1.60mm, 1.56mm, and 1.00mm, respectively. In summary, Ref-DTS-FBCT has the worst registration accuracy among all the methods. Ref-DTS-4DCT-phase is more accurate than Ref-DTS-AIP for registering moving target position. Preliminary results indicated that the localization accuracy could be further improved with Ref-DTS-4DCT-Amp when breathing amplitude changes dramatically from CT scan to on-board DTS scan. Conclusions: Both Ref-DTS-4DCT-Amp and Ref-DTS4DCT-Phase are potentially very useful for moving target localization when used appropriately for different patient scenarios. Imaging dose can be significantly reduced using these methods compared to 3D or 4D CBCT.
Deuterated iodoacetanilide: a covalent protein label for neutron scattering studies.

Abstract A simple preparation of a deuterated alkylating reagent is described. Its reaction with the β93-SH groups of hemoglobin was used to illustrate the preparation of a protein derivative which contains 5 covalently attached non-exchangeble deuterium atoms at a unique locus on each β chain.
Atheroembolic renal disease: effect on morbidity and survival after revascularization for atherosclerotic renal artery stenosis.

AbstractPurpose: Atheroembolic renal disease is increasingly found in older patients with general atherosclerosis. We evaluated the impact of atheroembolic renal disease on morbidity and survival after surgical revascularization for atherosclerotic renal artery stenosis.Materials and Methods: The study group comprised 44 patients who underwent surgical revascularization for atherosclerotic renal artery stenosis and concomitant intraoperative renal biopsy. Renal biopsy specimens were reviewed by a pathologist and evaluated for the presence or absence of atheroemboli, and the presence and severity of arteriolar nephrosclerosis. Postoperative patient data were reviewed to evaluate survival, and the incidence of renal and systemic morbid events. Patients were followed for 1 to 14.5 years (median 6.2) after surgical revascularization.Results: Atheroembolic renal disease was identified in the intraoperative biopsy specimen in 16 patients (36%, group 1) and was absent in 28 (64%, group 2), termed groups 1 and 2....
Analysis of structures with saturated hydrogen bonding. Corrigendum

Corrected space groups for the paper by Loehlin & Okasako (2007), Acta Cryst. B63, 132–141 are given.
Thrombus formation with rehydrated, lyophilized platelets.

AbstractStored human platelets are frequently used in hemorrhagic emergencies, but have limited immediate utility for controlling bleeding due to storage lesion and are frequently contaminated with microorganisms. The development of paraformaldehyde-treated, lyophilized and rehydrated (RL) platelets, which are sterile and have a prolonged shelf life (years), ameliorate the efficacy and sterility problems with stored platelets. RL platelets have been shown to have many native functions of fresh platelets in vitro and to mediate hemostasis in vivo in large animal models of hemorrhagic shock and cardiopulmonary bypass induced platelet dysfunction. To further evaluate the functional properties of this transfusion product, we studied the role of RL platelets in three aspects of thrombus formation and lysis. First, the interaction between RL platelets and fibrinogen was investigated. The surface density of unligated GPIIb-IIIa on RL and fresh platelets were, respectively 30,000 and 70,000 molecules per cell as ...
Peptide antagonists of angiotensin-induced adrenal catecholamine release

Abstract The effect of analogs of angiotensin (modified with an Ile-substituted for Phe) was studied in the isolated, retrogradely perfused adrenal of the cat. Continuous differential analysis of norepinephrine and epinephrine output was quantified with an automated trihydroxyindole procedure. [Ile8]-angiotensin I and [Ile7]-angiotensin III exhibited negligible secretory activity, in contrast to the stimulatory effects of [Ile8]-angiotensin II (10–20% activity relative to angiotensin II). [Ile8]-angiotensin I blocked angiotensin II-induced catecholamine secretion and a pA2 value of 8.50 was obtained. [Ile7]-angiotensin III was an especially potent antagonist of angiotensin II and a pA2 value of 10.4 was calculated for this heptapeptide analog. The pA2 value for [Ile8]-angiotensin II, a partial agonist in the adrenal medulla was 9.33. These three analogs were equally effective against secretion induced by the corresponding unsubstituted homologs (Ang I and Ang III). These data suggest that all these angiotensin peptides interact with a common receptor. [Ile8]-angiotensin I and [Ile7]-angiotensin III had no effect on adrenal medullary responses induced by KCl, nicotine and bradykinin. These structural analogs of angiotensin are pure competitive antagonists of angiotensin in the cat adrenal chromaffin cell.
Tree-structured statistical modeling via convex optimization

We develop a semidefinite-programming-based approach to stochastic modeling with multiscale autoregressive (MAR) processes—a class of stochastic processes indexed by the vertices of a tree. Given a tree and the covariance matrix of the variables corresponding to the leaves of the tree, our procedure aims to construct an MAR process with small state dimensions at each vertex that approximately realizes the given covariance at the leaves. Our method does not require prior specification of the state dimensions at each vertex. Furthermore, we establish a large class of MAR processes for which, given only the index tree and the leaf covariance of the process, our method can recover a parametrization that matches the leaf-covariance and has the correct state dimensions. Finally we demonstrate, using synthetic examples, that given i.i.d. samples of the leaf variables our method can recover the correct state dimensions of an underlying MAR process.
The effect of substitution of the N -acetyl groups of N -acetylgalactosamine residues in chondroitin sulfate on its degradation by chondroitinase ABC

Chondroitinase ABC is a lyase that degrades chondroitin sulfate, dermatan sulfate and hyaluronic acid into disaccharides. The purpose of this study was to determine the ability of chondroitinase ABC to degrade chondroitin sulfate in which the N-acetyl groups are substituted with different acyl groups. The bovine tracheal chondroitin sulfate A (bCSA) was N-deacetylated by hydrazinolysis, and the free amino groups derivatized into N-formyl, N-propionyl, N-butyryl, N-hexanoyl or N-benzoyl amides. Treatment of the N-acyl or N-benzoyl derivatives of bCSA with chondroitinase ABC and analysis of the products showed that the N-formyl, N-hexanoyl and N-benzoyl derivatives are completely resistant to the enzyme. In contrast, the N-propionyl or N-butyryl derivatives were degraded into disaccharides with slower kinetics compared to that of unmodified bCSA. The rate of degradation of bCSA derivatives by the enzyme was found to be in the order of N-acetyl>N-propionyl>>N-butyryl bCSA. These results have important implications for understanding the interaction of N-acetyl groups of glycosaminoglycans with chondroitinase ABC.
The Navajo–U.S. Population Mortality Crossover since the Mid-20th Century

Mortality crossovers at older ages have been observed when comparing different populations, particularly disadvantaged populations with advantaged populations. A growing body of research indicates that mortality convergences to actual crossovers are real and not a result of overstating of age at the older ages. Only recently have the mortality experiences of Native Americans been compared with those of other Americans; specific Native American tribal populations have not been examined, however. Presented here are the mortality experiences of the Navajo and those of the total U.S. population and U.S. white population since the mid-20th century. Comparison provides further support to findings that convergences and crossovers actually occur between disadvantaged and advantaged populations.
Follicular morphology, oocyte diameter and localisation of fibroblast growth factors in the domestic dog ovary.

Remarkably little is known about folliculogenesis in the dog. Objectives were to characterise (1) changes in follicle/oocyte diameter and granulosa cell number and (2) localisation of fibroblast growth factor (FGF)-2 and FGF-7 during dog ovarian follicle development. Fourteen ovarian pairs were excised and processed for histological evaluation. Two to four serial sections/bitch were stained with hematoxylin, and follicle/oocyte diameters and granulosa cell number were determined at each developmental stage. Mean follicle and oocyte size were compared among stages by one-way analysis of variance. Relationships between follicle and oocyte size and granulosa cell number were determined using correlation and regression analysis, respectively. Another eight serial sections/bitch were processed for immunostaining to determine FGF-2 and FGF-7 localisation. Primordial and primary follicles were similar in size, but smaller than the progressively increasing (p 0.05) thereafter. Oocyte size and granulosa cell number increased (p < 0.01) with follicular diameter. Except during anoestrus, FGF-2 occurred in oocytes and granulosa cells of primordial to secondary follicles. In adult bitches, FGF-7 was localised in granulosa cells of primary and secondary follicles and also occurred in the theca layer of antral follicles during prooestrus and oestrus. In summary, folliculogenesis in the domestic dog occurs in two phases: pre-antral phase characterised by increasing follicle size in association with oocyte growth and granulosa cell proliferation and antral phase linked with marked granulosa cell proliferation and accumulation of antral cavity fluid. Finally, the temporal localisation pattern of FGF-2 implies its role in follicular activation, whereas FGF-7 activities appear related to later folliculogenesis.
Stage I palliation for hypoplastic left heart syndrome in low birth weight neonates: can we justify it?

Objective: Although the outcome of cardiac surgery in neonates with low birth weight (LBW) has improved, LBW remains a risk factor for surgical palliation. Few surgical series of LBW patients include those with hypoplastic left heart syndrome (HLHS). To identify variables associated with poor outcome in this group, we reviewed our experience with patients with HLHS and LBW who underwent Stage I Norwood palliation. Methods: Between January 1998 and December 2000, 20 consecutive LBW (,2500 g) neonates with HLHS ðn ¼ 13Þ or HLHS variant ðn ¼ 7Þ underwent surgical palliation. Retrospective review of all patient data and analysis to identify risk factors was performed. Results: Mean age at surgery was 5.1 ^ 4.6 days (range 1–17), mean weight was 1.98 ^ 0.44 kg (range 1.1–2.5), including nine patients under 2 kg. Ten patients were born at ,35 weeks gestation. Anatomic diagnosis included HLHS in 13 patients (10 with aortic atresia), unbalanced atrioventricular canal defect in two, double outlet right ventricle in two and other variants in three. Mean ascending aortic size was 4.0 ^ 1.8 mm (range 1.5–8). Associated cardiac defects were present in three patients, and a genetic syndrome and/or congenital anomaly was present in four of them. Mean circulatory arrest time was 60 ^ 10 min. Extracorporeal support was used perioperatively in 10 patients. Early mortality was 9/20 (45%). At a mean follow up at 22 ^ 10 months (range 8–38), six patients underwent stage II, and are awaiting stage III; four patients have completed their Fontan. Anatomic variant, ascending aortic size, prematurity, age at surgery, weight, duration of circulatory arrest, cardiopulmonary bypass time and associated non-cardiac anomalies were not risk factors for poor outcome whereas restrictive pulmonary venous drainage and coronary artery anomalies were associated with decreased survival. Conclusion: LBW newborns with HLHS and physiologic variants have an increased early surgical risk but have acceptable intermediate survival rates for subsequent palliation including Fontan. LBW and prematurity should not be contraindications to early surgical palliation. q 2002 Elsevier Science B.V. All rights reserved.
Variability of Spontaneous and Exercise-Induced Ventricular Arrhythmias in the Absence and Presence of Treatment With Acebutolol or Quinidine

A randomized double-blind crossover trial was undertaken in 20 volunteers to evaluate the effects of acebutolol and sustained release quinidine sulfate. The patients had an average of 10 or more premature ventricular complexes/hour on two 24 hour electrocardiographic recordings, or 10 or more/min during two cycle stress tests, or any number of complex forms of ventricular ectopic activity on either test. The 24 hour recordings yielded greater detection of complex forms than did stress tests and manifested similar relative variability in frequency of ventricular ectopic beats. The extent of variability from hour to hour within the 24 hour monitoring periods tended to have an increasing relation with frequency of ectopic beat activity regardless of the presence or absence of treatment. Within-patient variability among periods with equivalent treatment status also tended to have such an increasing relation with frequency of ectopic beat activity. About 35 percent of the variation was among subjects, 20 percent among months within subjects, 20 percent among days in months and 25 percent among hours in days. Acebutolol, 300 mg three times daily, produced effective beta receptor blockade and was better tolerated than sustained release quinidine sulfate in identical doses and had equal suppressant effects. The results of the variability studies provide guidelines for the design of adequate clinical trials testing suppressant interventions.
MAGNETOACOUSTIC EMISSION AND DISCONTINUOUS MAGNETOSTRICTION IN TERFENOL - D

This paper reports measurements of magnetostriction λ and magnetoacoustic emission MAE in a specimen of the most recent Tb0.3Dy0.7Fe1.9 produced at Ames Laboratory. This specimen was produced by float zone solidification and was then annealed at 950 °C for one hour. The magnetostriction in a field of 3,000 Oe, under a compressive stress of 14 MPa, reached 2, 200 x 10-6. Magnetoacoustic emission signals were found to exhibit peak activity close to the maxima in dλ / dH.
Vocally mediated reciprocity between neighbouring groups of mantled howling monkeys, Alouatta palliata palliata

Abstract The hypothesis that acoustic communication mediates spacing between groups of mantled howling monkeys, Alouatta palliata palliata, was tested experimentally in a Costa Rican forest. Previous work showed that reverberation increases with the distance sound propagates within the forest and thus could provide distance cues to monkeys. Two series of barks were therefore played back to test groups: the first series simulated the calls of a male withdrawing from the test group; the second series simulated the calls of an approaching male. In response, males approached the sounds of an apparently approaching male and withdrew from an apparently withdrawing male. Thus reverbration provided cues about distance to the howling monkeys. The direction in which the monkeys moved depended on the direction of movement simulated by the call sequence. Furthermore, the pattern of reciprocated movements, which exemplifies a form of the evolutionarily stable strategy ‘Tit-For-Tat’, helps to regulate relations between neighbouring males and hence spacing between neighbouring groups.
Solving the Pipe Network Analysis Problem Using Optimization Techniques

For more than forty years, approximate solutions for the classical pipe network analysis problem have been obtained by direct solution of the nonlinear stationary point conditions. We propose a revolutionary new approach involving optimization techniques for solving this well-known engineering problem. It is shown that the pipe network analysis problem may be described mathematically in terms of a nonlinear convex cost network flow problem. Three mathematical programming algorithms for solving this problem have been coded and are computationally compared with a code using the traditional Newton-Raphson technique. The computational experience demonstrates that this new approach provides an attractive alternative for solving this important problem.
URODYNAMIC PATTERN IN INFANTS WITH URINARY TRACT INFECTION

AbstractPurpose: We studied the urodynamic pattern in infants with urinary tract infection and evaluated the influence of the infection.Materials and Methods: Cystometry was combined with voiding cystourethrography (video cystometry) and 90 male and 68 female infants admitted to the hospital with first time urinary tract infection. Evaluation was performed 1 to 30 days (mean 11) and 32 to 78 days (mean 46) after diagnosis in 93 and 65 infants, respectively.Results: Bladder instability was found in two-thirds of male and female infants. Compared to older children male infants had high voiding detrusor pressure and low bladder capacity (hypercontractility). Female infants also had increased voiding pressure levels but they were significantly lower than those in male infants. The voiding detrusor pressure was even higher in both sexes when evaluation was delayed after the infection.Conclusions: Infants with urinary tract infection have bladder instability and hypercontractility compared to older children. Bl...
Kinetics of NH3 decomposition on single crystal planes of Pt

Abstract The rate of NH 3 decomposition on (111), (100), (110) and (210) planes of Pt have been measured between 600 and 1400 K and between 10 −2 and 1 Torr in a low conversion flow system with mass spectrometric gas analysis. Surfaces were in the form of thin discs which were heated by focussed light beams to achieve uniform temperatures. The open (210) plane has almost the same activity as polycrystalline wires or foils, and rates decrease in the order (210) > (110) > (111) > (100). Temperature and pressure dependences agree quite well with a Langmuir-Hinshelwood (LH) expression from which reaction and adsorption activation energies on each plane are obtained. On (100) and (111) the rate is 10 times less than on high activity planes and this rate may be largely due to reaction on the edges of the crystals. From AES analysis of surfaces and reproducibility of results it is suggested that surfaces are free of contaminants in these experiments.
Dependence of Ocean Heating on the Distribution of Spectral Irradiance in the North Atlantic

Subsurface heating rates from visible solar irradiance were computed for the North Atlantic for May 1979 during the period of the spring bloom. The visible spectrum between 400 and 700 nm accounts fora substantial fraction, about 43%, of the total solar irradiance at the sea surface, and comprises most of the solar irradiance that penetrates more than a meter into the sea. The mean monthly spectral diffuse attenuation coefficients and surface solar irradiance were used to compute heating rates at 390, 440, 490, 540, 590, 640, and 690 nm over depth increments of 0 - 5, 5 - 10, 10 - 15, 15 - 20, and 20 - 35 m. At low latitudes, in the North Atlantic, significant solar heating occurs at depth as a consequence of high solar irradiance and clear waters. In the northern latitudes the heating is confined near the surface at all wavelengths as a result of high turbidity. Significant spatial variation in the spectral heating rates is observed as a result of chlorophyll and aerosol patchiness.
Influences on the antenatal clinic attendance of Central Province women in Port Moresby, PNG.

Abstract Public antenatal health care services in the National Capital District (NCD) of Papua New Guinea are provided at some of the nurse operated urban satellite clinics and at a large outpatient clinic at Port Moresby General Hospital (PMGH). The major functions of the antenatal clinics are screening for high risk cases and giving routine medications. In this they are following the policy of the National Health Plan and the recommendations of the Public Health Department reports on which it was partially based. The purpose of this study was to examine some of the characteristics of a particular segment of the clientele at the PMGH antenatal clinic and to explore their motivation for attendance, especially the timing of their first visit. After an initial survey of the clinic record cards of all women attending the PMGH clinic in September 1980, interviews were conducted with a stratified sample of women attending clinic sometime between February and June 1981. Only women indigenous to the NCD and the surrounding province were included in the study. From clinic record cards, information was obtained on each woman's residence, birthplace, parity, gestational stage at first clinic visit, place of previous deliveries, clinical/laboratory measures and obstetric history. The interviews were conducted in a private room near the clinic in a language preferred by the interviewee. Their responses clarified some of the background data on their clinic cards and provided additional information on why they came to the clinic when they did. In general, the sample group was highly oriented toward Western-based medical care. They came to have themselves and their babies examined for possible problems, to receive the right amounts of the right medicines, and to get information. This was consistent with both policy and services. They also came because of the perceived effectiveness of the clinic and sometimes because it was the ‘proper thing to do’. Many factors influenced their choice of when and where to seek antenatal services, including advice from husbands as well as from traditional female sources. Their previous experiences with hospitals and clinics and with pregnancy in general were also important.
Producing biodiesel from cottonseed oil using Rhizopus oryzae ATCC #34612 whole cell biocatalysts: Culture media and cultivation period optimization

article i nfo The effect of culture medium composition and cultivation time on biodiesel production by Rhizopus oryzae ATCC #34612 whole cell catalysts, immobilized on novel rigid polyethylene biomass supports, was investigated. Supplementation of the medium with carbon sources led to higher lipase activity and increased the biomass immobilized on the BSPs. Statistical analysis indicates that a cultivation period of 72 h in a basal medium supplemented with both cottonseed oil and glucose is optimal for biodiesel production by R. oryzae ,r esulting in a fatty acid methyl ester (FAME) yield of 27.9 wt.% (228.2 g/L).
First-principles study of Cu/TiN and Al/TiN interfaces: weak versus strong interfaces

Using density functional theory based first-principles calculations, we show that the preferred interfacial plane orientation relationship is determined by the strength of bonding at the interface. The thermodynamic stability, and the ideal tensile and shear strengths of Cu(1 1 1)/TiN(1 1 1) and Al(1 1 1)/TiN(1 1 1) interfaces are calculated. While there is a strong orientation relation preference for the Al/TiN interface, there is no orientation relation preference for the Cu/TiN interface. Both the ideal tensile and shear strengths of Cu/TiN interfaces are lower than those of bulk Cu and TiN, suggesting such interfaces are weaker than their bulk components. By comparison, the ideal strengths of the Al/TiN interface are comparable to the constituents in the bulk form. Such contrasting interfaces can be a test-bed for studying the role of interfaces in determining the mechanical behavior of the nanolayered structures.
The 'Tuskegee Study' of syphilis: analysis of moral versus methodologic aspects

The background and course of the prospective investigation of the “natural history” of syphilis which was conducted by the U.S. Public Health Service in Macon County, Alabama from 1932 to 1972 (the “Tuskegee Study”) is reviewed. Unpublished correspondence is cited to illustrate some of the attitudes and problems of the investigators. The relevance of certain other studies of syphilis to the interpretation of the Tuskegee data which were not discussed by the investigators is shown. The study is analyzed by the application of some general principles of scientific investigation set forth at the beginning of the article.
IRONSIDES: DNS with no single-packet denial of service or remote code execution vulnerabilities

We describe the development of IRONSIDES, an implementation of DNS that is provably invulnerable to remote code execution exploits and single-packet denial of service attacks. Our experimental results show it to be over three times as fast as BIND, the most common implementation of DNS.
Space Variant Optical Pattern Recognition

Space variant optical processors using coordinate transformations are considered as advanced optical pattern recognition systems. A general formulation of the processing method used is provided together with seven examples of the use of this processing technique in both image and signal processing.© (1977) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Mechanism of Association and Reciprocal Activation of Two GTPases

The signal recognition particle (SRP) mediates the cotranslational targeting of nascent proteins to the eukaryotic endoplasmic reticulum membrane or the bacterial plasma membrane. During this process, two GTPases, one in SRP and one in the SRP receptor (named Ffh and FtsY in bacteria, respectively), form a complex in which both proteins reciprocally activate the GTPase reaction of one another. Here, we explore by site-directed mutagenesis the role of 45 conserved surface residues in the Ffh-FtsY interaction. Mutations of a large number of residues at the interface impair complex formation, supporting the importance of an extensive interaction surface. Surprisingly, even after a stable complex is formed, single mutations in FtsY can block the activation of GTP hydrolysis in both active sites. Thus, activation requires conformational changes across the interface that coordinate the positioning of catalytic residues in both GTPase sites. A distinct class of mutants exhibits half-site reactivity and thus allows us to further uncouple the activation of individual GTPases. Our dissection of the activation process suggests discrete conformational stages during formation of the active SRP•SRP receptor complex. Each stage provides a potential control point in the targeting reaction at which regulation by additional components can be exerted, thus ensuring the binding and release of cargo at the appropriate time.
Cumulant-based adaptive FIR filtering for frequency estimation

Proposes an alternative technique for adaptive line enhancers (ALE). The new technique uses the fourth order cumulant, which is insensitive to white or colored Gaussian noise. The conventional ALE relies on measurements of the autocorrelation and/or power spectrum of the observations, or on the assumption that the additive noise is white. The autocorrelation is affected by additive Gaussian noise, and in many practical situations, the noise is spatially or temporally correlated. The proposed technique is insensitive to additive Gaussian noise. This is the main advantage of this new technique. Computer simulation has been performed. >
Pedicled groin flaps for upper-extremity reconstruction in the elderly: A report of 4 cases

The pedicled groin flap is a useful, versatile flap for coverage of wounds of the hand and distal forearm. It produces predictable results with a procedure that is much less difficult to perform and takes less time than a free-tissue transfer. Contrary to the general belief that the groin flap should not be used in the elderly because of the risk of shoulder stiffness, we found satisfactory results with this procedure in 4 elderly patients (age range, 59-75 y) when immediate shoulder mobilization was instituted and physical therapy was continued during flap maturation and pedicle division.
Serum Levels of Carnitine in Chronic Fatigue Syndrome: Clinical Correlates

Carnitine is essential for mitochondrial energy production. Disturbance in mitochondrial function may contribute to or cause the fatigue seen in chronic fatigue syndrome (CFS) patients. One previous investigation has reported decreased acylcarnitine levels in 38 CFS patients. We investigated 35 CFS patients (27 females and 8 males); our results indicate that CFS patients have statistically significantly lower serum total carnitine, free carnitine and acylcarnitine levels, not only lower acylcarnitine levels as previously reported. We also found a statistically significant correlation between serum levels of total and free carnitine and clinical symptomatology. Higher serum carnitine levels correlated with better functional capacity. These findings may be indicative of mitochondrial dysfunction, which may contribute to or cause symptoms of fatigue in CFS patients.
Mortality among rubber chemical manufacturing workers.

Background A retrospective cohort mortality study evaluated ischemic heart disease (IHD) among workers in the “rubber chemicals” manufacturing department of a Western New York plant. A previous study at the plant found elevated chest pain and angina among workers in this department. Methods Mortality experience of workers employed from 1946–1988 was followed through December 31, 1994. Mortality was compared to U.S. population rates and to local Niagara county rates by using the NIOSH life table analysis system. Poisson regression was used to examine patterns of IHD within the cohort. Results The standardized mortality ratio (SMR) for IHD among workers in the rubber chemicals department was 1.51 (U.S. rates) and 1.19 (Niagara county rates). Increased mortality from IHD in the rubber chemicals department was most pronounced at younger ages (< 50, SMR = 2.4); workers in a second chemical production department also had an elevated (but not statistically significant) SMR of 1.5 for IHD. Conclusions IHD mortality among workers in the rubber chemicals department was elevated, particularly among those under 50 years of age. Potential occupational risk factors for IHD include the rotating shift pattern for employees assigned to two chemical production departments and chemical exposures present in the rubber chemicals department. Am. J. Ind. Med. 37:590–598, 2000. Published 2000 Wiley-Liss, Inc.
The effects of behavior rehearsal and feedback on the acquisition of problem-solving skills in distressed and nondistressed couples

Abstract Couples who were paid to participate in an experimental marital enrichment program were randomly assigned to one of four treatment conditions or to a control group. All groups received training in solving marital problems, but the groups differed according to how they were trained; some received feedback (FB) on their previous taped performances, some had the opportunity to practice the skills suggested by the therapist (BR), some had both (complete treatment), and some simply were presented with instructions. Changes in problem-solving skills were assessed by behavioral observations of the frequency of positive problem-solving behavior before and after treatment, and global ratings of problem-solving effectiveness made by trained raters. In general, the complete treatment condition produced greater changes from pre- to post-test than any other condition. Couples in this condition showed significantly greater increases in positive behavior than any other group, and on global ratings of problem-solving skills they evidenced the greatest improvement, although on this measure they did not improve significantly more than BR couples.
Issues and current applications of interspecies extrapolation of carcinogenic potency as a component of risk assessment.

The Life Sciences Research Office (LSRO) of the Federation of American Societies for Experimental Biology (FASEB) is conducting this symposium under contract with the Center for Food Safety and App...
Intestinal serotonin acts as a paracrine substance to mediate vagal signal transmission evoked by luminal factors in the rat

The vagus nerve conveys primary afferent information produced by a meal to the brainstem. Serotonin (5-HT), which abounds in intestinal enterochromaffin cells, is released in response to various stimuli. We have recently demonstrated that 5-HT released from intestinal enterochromaffin cells activates 5-HT3 receptors on vagal afferent fibres to mediate luminal non-cholecystokinin-stimulated pancreatic secretion. The present study was designed to evaluate the responses of vagal sensory neurons to intraluminal osmotic stimulation and luminal infusion of maltose, glucose or 5-HT. We investigated the role of endogenous 5-HT in signal transmission evoked by luminal stimuli to activate vagal sensory neurons. The discharges of vagal primary afferent neurons innervating the intestine were recorded from rat nodose ganglia. Luminal factors such as intestinal osmotic stimuli and perfusion of carbohydrates elicited powerful vagal nodose responses. Electrical subdiaphragmatic vagal stimulation activated 364 single units; 40 of these responded to intestinal mucosal stimuli. Of these 40, 30 responded to intraduodenal perfusion of hyperosmolar NaCl (500 mosmol l(-1)), 27 responded to tap water (5 mosmol l(-1)) and 20 and 19 responded to maltose (300 mM) and glucose (277.5 mM), respectively. The 5-HT3/4 antagonist tropisetron (ICS 205-930) or 5-HT3 antagonist granisetron abolished luminal stimuli-evoked nodose neuronal responses. Intraluminal infusion of 10(-5) and 10(-4) M 5-HT elicited increases in vagal afferent discharge in 25 and 31 units, respectively, by activating the 5-HT3 receptors. Acute subdiaphragmatic vagotomy, intestinal mucosal application of the local anaesthetic lidocaine (lignocaine) or administration of 5-HT3 antagonist each abolished the luminal 5-HT-induced nodose neuronal responses. In contrast, distension-sensitive neurons did not respond to duodenal infusion of 5-HT. Pharmacological depletion of 5-HT stores using p-chlorophenylalanine (PCPA), a 5-HT-synthesis inhibitor, abolished luminal factor-stimulated nodose neuronal responses. In contrast, pretreatment with 5,7-dihydroxytryptamine (5,7-DHT), a specific 5-HT neurotoxin that destroys 5-HT-containing neurons without affecting 5-HT-containing mucosal cells, had no effect on these responses. These results suggested that the nodose neuronal responses to luminal osmolarity and to the digestion products of carbohydrates are dependent on the release of endogenous 5-HT from the mucosal enterochromaffin cells, which acts on the 5-HT3 receptors on vagal afferent fibres to stimulate vagal sensory neurons.
Quasi-Static Cyclic Testing of a Large-Scale Hybrid Sliding-Rocking Segmental Column with Slip-Dominant Joints

This paper presents the findings of an experimental study that investigated the response properties of segmental cantilever columns incorporating internal unbonded posttensioning (PT) and slip-dominant (SD) joints. The SD joints exhibited controlled sliding that provided energy dissipation with low damage. All joints of these columns, except for the bottom one, were designed to be SD. The bottom joint was designed to be rocking dominant (RD) and exhibited rocking that offered self-centering to the system. Design objectives and equations are presented. These equations were used for the design of a large-scale cantilever column that was subjected to reverse lateral cyclic loading at its top end, reaching a maximum drift ratio of 14.9%. At small drift ratios (≤3%), the response was dominated by sliding of the SD joints that provided energy dissipation (damping). For medium drift ratios (between 3 and 10%), rocking at the bottom joint increased and provided self-centering properties to the system. For large drift ratios (>10%), the self-centering properties decreased, but the damping properties remained practically constant. Rocking at the SD joints remained small at all times. Minor spalling was observed in the SD joints, while concrete crushing was observed at the bottom joint.
Stable isotopic and petrological constraints on scapolitization of the Whitestone meta‐anorthosite, Grenville Province, Ontario*

The Whitestone Anorthosite (WSA), located in the Central Gneiss Belt of the south-western Grenville Province, Ontario, exhibits a nearly concentric metamorphic envelope characterized by an increase in modal scapolite, hornblende, epidote and garnet, developed around a core of granulite facies clinopyroxene ± orthopyroxene ± garnet meta-anorthosite. Scapolite- and hornblende-bearing assemblages develop mainly at the expense of plagioclase and pyroxene within the envelope. Stable isotopic and petrological data for scapolite-bearing mineral assemblages within meta-anorthosite constrain the source of carbon responsible for CO3-scapolite formation and the extent of fluid/rock interaction between the anorthosite and adjacent lithologies. Stable isotopic data indicate increasing δ18O and δ13C from core to margin of the meta-anorthosite and for samples from the southern extension of the WSA, where it is ductilely deformed within the Parry Sound Shear Zone (PSSZ). The average δ18OSMOW value (whole rock) for the WSA core is 6.9‰, increasing to 11.5‰ where the WSA is in tectonic contact with marble breccia. The average δ13CPBD value of scapolite in meta-anorthosite from the centre of the WSA is -3.4‰, increasing to -0.5‰ at the eastern (marble) contact. Average values of δ13C for scapolite and whole-rock δ18O for samples from the shear zone are -1.0 and 8.0‰, respectively. Marbles have average δ18O and δ13C values of 19.2 and -0.4‰, respectively. The sulphate content of texturally primary scapolite decreases from the core of the WSA (XSO4= 0.48) to the eastern contact (≤0.05). Texturally late scapolite after plagioclase and garnet tends to be CO3-rich relative to texturally primary scapolite, and some scapolite grains show zoning in the anion site with CO3-enriched rims. Scapolite composition may vary at any scale from a single grain to outcrop. The pattern of isotopic enrichment in 13C and 18O preserved in the eastern margin of the WSA is consistent with marble as the major source of fluid contributing to the formation of the metamorphic envelope. The decrease in XSO4 and increase in XCO3 in scapolite toward the margin of the WSA indicate that the volatile content was reset by, or developed from, a CO2-bearing fluid. Assuming derivation of fluid from marble, minimum fluid/rock values at the margin of the WSA range from 0.03 for the least enriched, to 0.30 for the most isotopically enriched samples. Although marble is not found in immediate contact with samples of sheared meta-anorthosite from the PSSZ, a marble source is also consistent with the C and O isotope composition and anion chemistry of scapolite within these samples.
Oscillations of neutral differential equations with variable coefficients

We obtain sufficient conditions for the oscillation of all solutions of the neutral differential equation d\dt [y(t) + P(t)y(t-T)] + Q(t)y(t-σ) = 0 where our results extend and improve several known results in the literature. These improvements and extensions are obtained by establishing and using some lemmas which are interesting in their own rights and which may have further applications in analysis.
Surface-to-surface missile guidance with passive homing

Most deployed , surface-to-surface, antitank missile systems do not use passive homing. These systems require an operator for target tracking and utilize guidance strategies that command the missile along the line- of-sight (LOS) to the heavily armored areas of the tank. The target kill probability, Pk, for these systems is limited by the LOS guidance strategy and operator error. Therefore, new approaches including passive homing and non-LOS guidance are being developed to increase Pk for future antitank missile systems. Passive homing removes operator error during flight, and non-LOS guidance (ie: top attack) yields warhead impacts on the top areas of tanks which have less armor. A passive, top attack, antitank missile has many advantages; however, it relies greatly on a passive seeker to provide correct target state information under a variety of battlefield conditions. This paper introduces effects of missile-to-target range and line-of-sight (LOS) on passive seeker performance in battlefield conditions for a surface-to-surface missile (SSM) using an imaging infrared (IIR) seeker. Using this analysis, an adaptive missile guidance concept based on several guidance strategies is proposed to maximize Pk. Fundamental considerations and challenges for the proposed missile guidance concept are mentioned.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A first look at the distribution of the stable isotopes of silicon in natural waters

The first data on the distribution of the stable isotopes of silicon in marine and freshwater systems are reported. Both marine and riverine δ30Si are more positive than δ30Si of igneous rocks, suggesting isotopic fractionation during weathering and clay formation and/or biomineralization. The δ30Si value for dissolved silicic acid from several ocean basins is +1.1 ± 0.3‰ (n = 69). More positive values are found in surface waters, due to discrimination against 30Si during biogenic opal formation by diatoms. The deep Pacific Ocean is depleted in 30Si relative to the deep Atlantic by roughly 0.4‰. δ30Si of riverine dissolved silicon averages +0.8 ± 0.3 (n = 8). The biologic fractionation of silicon isotopes coupled with effects associated with thermohaline circulation appears to play a significant role in controlling the distribution of silicon isotopes in the sea. The average δ30Si value of inputs of silicon to the ocean most likely falls between +0.3 and +0.9‰, and that of the outputs falls between +0.9 to +1.9‰, probably in the neighborhood of +1.0‰.
Normal cones to infinite intersections

Abstract For sets given as finite intersections A = ⋂ k = 1 K A k the basic normal cone N ( x ; A ) is given as ∑ k N ( x ; A k ) , but such a result is not, in general, available for infinite intersections. A comparable characterization of N ( x ; A ) is obtained here for a class of such infinite intersections.