cssi/SciSciGPT-SciSciNet huggingface dataset:
Wire-Array Z-Pinch Length Variations for K-Shell X-Ray Generation on Z

In developing stainless-steel (SS) and copper wire-array X-ray sources on the Z machine, we consider the optimization of K-shell yield as a function of load height. Theory, numerical modeling, and experimental data suggest that an optimum exists corresponding to a tradeoff between the increase in radiating mass and the decrease in coupled current with increasing pinch height. A typical load height of 20 mm used on many previous Z wire-array X-ray sources is found to be near optimal for K-shell yield production in SS and copper implosions. Electrical data, pinhole imaging, and spectroscopy are used to study plasma conditions in wire-array z pinches corresponding to the variation in K-shell power and yield per unit length as the pinch height is changed from 12 to 24 mm.
Services-oriented computing in a ubiquitous computing platform

Current telematics services platforms are tightly integrated, relatively fixed-function systems that manage the entire end-to-end infrastructure of devices, wireless communications, device management, subscriber management, and other functions. This closed nature prevents the infrastructure from being shared by other applications, which inhibits the development of new ubiquitous computing services that may not in themselves justify the cost of an entire end-to-end infrastructure. Services-oriented computing offers means to better expose the value of such infrastructures. We have developed a services-oriented, specification-based, ubiquitous computing platform called TOPAZ that abstracts common ubiquitous computing functions and makes them accessible to any application provider through Web-service interfaces. The nature of the TOPAZ services, as enabling long-running sessions between applications and remote clients, presents peculiar challenges to the generic issues of service metering and resource management. In this paper we describe these challenges and discuss the approach we have taken to them in TOPAZ. We first motivate and describe the TOPAZ application model and its service set. We then describe TOPAZ's resource management and service metering functions, and its three-party session model that forms the basis for them.
Affirmatively Furthering Fair Housing: The Search for Solutions That are Just Right

A federal False Claims Act action against Westchester County, New York launched a unique effort to explore whether zoning, subsidies, and advocacy could significantly Increase the percentage of minorities living in largely white communities. A Voluntary Cooperation Agreement entered into by Marin County, California raises a similar question. This article describes the legal background of the lawsuit brought against Westchester County, the Settlement Agreement that arose from it, and the attempt by Westchester County to carry out its obligations to affirmatively further fair housing. It traces the evolution of exclusionary zoning law in New York State courts, contrasts it to statutory approaches in New Jersey and Connecticut, and reviews the tepid efforts of the New York State legislature to tackle the problem of articulating the affordable housing obligations of local governments. The authors detail the progress made in Westchester County and explain their own initiative to use training, education, and technical assistance to further the efforts by communities to provide fair and affordable housing. The article also explains the significance of the implementation of the Settlement Agreement and that while Westchester County will probably meet most of the literal terms of the Settlement, the goal of achieving significant racial integration in largely white census tracts, and all the benefits of diversity that integration achieves, remains elusive. Finally, it considers what can be done at the state level to achieve integration goals, while still pursuing other state policies regarding smart growth, climate change mitigation, energy conservation, and housing equity in densely settled urban areas.
Conformational changes at the highly reactive cystein and lysine regions of skeletal muscle myosin induced by formation of transition state analogues

Myosin forms stable ternary complexes with Mg2+-ADP and phosphate analogues of aluminum fluoride (AlF4-), beryllium fluoride (BeFn), and scandium fluoride (ScFn). These complexes are distinct from each other and may mimic different transient states in the ATPase cycle [Maruta et al. (1993) J. Biol. Chem. 268, 7093-7100]. Regions of skeletal muscle myosin containing the highly reactive residues Cys 707 (SH1), Cys 697 (SH2), and lysine 83 (RLR) dramatically alter their local conformation when myosin hydrolyzes ATP, and these changes may reflect formation of a series of transient intermediates during ATP hydrolysis. We used the fluorescent probes 4-fluoro-7-sulfamoylbezofurazan, 2-(4'-maleimidylanilino)naphthalene-6-sulfonic acid, and trinitrobenzene-sulfonate, which bind to SH1, SH2, and RLR, respectively, to examine differences in local conformations within myosin.ADP.phosphate analogue (BeFn, Vi, AlF4-, and ScFn) complexes. It was observed that the ternary complexes had SH1 conformations similar to those seen on S-1 in the presence of ATP. In contrast, local conformations in the SH2 and RLR regions of S-1.ADP.BeFn were different from those in corresponding regions of S-1.ADP.AlF4- or ScFn. These results suggest that SH1 and SH2 move distinctly during ATP hydrolysis and that the local conformations of the SH2 and RLR regions more sensitively reflect different transient states.
Integration and Preliminary Shipboard Observations of an Embedded Piloting Expert System

Safe navigation in restricted waters continues to be a perennial concern for shipowners, operators, navigators, and citizens. Much research has been conducted in order to determine the most efficient and effective methods for improving the safety of navigation and for training ships' officers and pilots. Decision aids improving the safety of navigation and supporting the cognitive skills of piloting-maneuvering, collision avoidance, and the practice of good seamanship-are of substantial interest. These decision aids can be standalone systems or embedded within an integrated bridge system or electronic chart display and information system (ECDIS), and can exhibit the properties of a real time knowledge-based control system. Following the March 1989 Exxon Valdez oil spill, Rensselaer Polytechnic Institute (RPI) began the development of a real time expert system, the Shipboard Piloting Expert System (SPES). This real time expert system was developed as an embedded intelligent software module within the ExxBridge integrated bridge system developed for Exxon Shipping Company by Sperry Marine, Inc. This paper describes the Shipboard Piloting Expert System, its integration and installation aboard the Exxon Benicia, and preliminary results of a 20-month operational assessment aboard the Exxon Benicia. Finally, the paper concludes with a discussion of future directions for the system.
Comments in Reply

In his paper Professor Fitzgerald has attempted to "correct" and extend a number of the arguments made in my paper "Self-Interest or Altruism: What Difference?" (1974). From my perspective his efforts constitute a potentially useful clarification of several of the points. To further that clarification, I would like to comment briefly on his remarks. One of Fitzgerald's major emphases is the observation that altruistic behavior may do nothing whatsoever to narrow the scope of conflict between two parties. In support of this claim he offers two sets of cases in which altruism fails in this respect. One is represented in Figure 2, the other in Figure 3. In the first case he notes that an altruist may get vicarious utility rewards from bearing a burden for another, but that the reward may be lower than the cost of the help rendered. Under those circumstances the rational altruist would choose not to assume any of the other's burden. This is, alas, an all too common empirical phenomenon. I expect that each reader has experienced exactly this kind of situation personally. It is one in which there is a genuine desire to help a friend, to engage in a charitable act, and so forth, but in which the costs of doing so are viewed as prohibitive. Professor Fitzgerald is correct in asserting that in such
A thirty year old conjecture about promise problems

Even, Selman, and Yacobi [ESY84, SY82] formulated a conjecture that in current terminology asserts that there do not exist disjoint NP-pairs all of whose separators are NP-hard viaTuring reductions. In this paper we consider a variant of this conjecture--there do not exist disjoint NP-pairs all of whose separators are NP-hard via bounded-truth-table reductions. We provide evidence for this conjecture. We also observe that if the original conjecture holds, then some of the known probabilistic public-key cryptosystems are not NP-hard to crack.
Hemorrhage from peptic ulcer: an analysis of 223 cases.

Bleeding from the upper gastrointestinal tract has attracted the attention and aroused the interest of physicians for many years. In the period before the diagnosis of ulcer of the stomach or duodenum could be established by x-ray the existence of such lesions was suspected by certain clinicians and the role of ulcer as the cause of massive hemorrhage from the upper gastrointestinal tract was assumed. Abercrombie!, in 1820, wrote in his text book concerning hemorrhage as follows; "The quantity of blood brought up is often immense, so that the patient is reduced to the last degree of exhaustion; and yet the disease is not often fatal." This observation by such an early investigator de­ serves our particular attention since it is a viewpoint which is often expressed in some modification on the wards of our hospitals to this day. The purpose of reviewing our experience with cases of proven ulcers with gross and massive hemorrhage has been in part to shed light upon this very point. The prognosis of massive hemorrhage from peptic ulcer is still a debated subject. The material used in this review consists of 223 cases of bleeding peptic ulcer which were observed at the Indiana University Medical Center. The patients were hospitalized in either the Indianapolis General Hospital, the Indiana University Hospitals or the Indianapolis Veterans Administration Hospital. The cases were seen between 1940 and 1950 in the first two in­ stitutions and between 1946 and 1950 in the Veterans Hospital. Cases of peptic ulcer confirmed by x-ray, operation or autopsy only were included. SEVERITY OF HEMORRHAGE Table I shows a classification of all cases according to severity of hemorrhage. Nothing is thought to be more important in the prognosis of a case of bleeding from a peptic ulcer than some estimation of the severity of the hemorrhage. Some semblance of uniformity in classifying such cases in this important regard is necessary. We have accepted the criteria of Fisher and Zuckerman 2 dividing all cases into four classes on the basis of the lowest red blood count and hemo­ globin determination. Even this method allows certain errors, particularly
Aquaporin-4 Expression in Adult and Developing Mouse and Rat Kidney

Aquaporin-4 (AQP4) is a member of the aquaporin water-channel family. AQP4 is expressed primarily in the brain, but it is also present in the collecting duct of the kidney, where it is located in the basolateral plasma membrane of principal cells and inner medullary collecting duct (IMCD) cells. Recent studies in the mouse also have reported the presence of AQP4 in the basolateral membrane of the proximal tubule. The purpose of this study was to establish the pattern of AQP4 expression during kidney development and in the adult kidney of both the mouse and the rat. Kidneys of adult and 3-, 7-, and 15-d-old mice and rats were preserved for immunohistochemistry and processed using a peroxidase pre-embedding technique. In both the mouse and the rat, strong basolateral immunostaining was observed in IMCD cells and principal cells in the medullary collecting duct at all ages examined. Labeling was weaker in the cortical collecting duct and the connecting tubule, and there was no labeling of connecting tubule cells in the mouse. In adult mouse kidney, strong AQP4 immunoreactivity was observed in the S3 segment of the proximal tubule. However, there was little or no labeling in the cortex or around the corticomedullary junction in 3- and 7-d-old mice. Between 7 and 15 d of age, distinct AQP4 immunoreactivity appeared in the S3 segment of the mouse proximal tubule concomitant with the differentiation of this segment of the nephron. Labeling of proximal tubules was never observed in the rat kidney. These results suggest that there are differences in transepithelial water transport between mouse and rat or that additional, not yet identified water channels exist in the rat proximal tubule.
CD13 is a novel regulator of TLR4 endocytosis in dendritic cells (CAM5P.241)

Toll like receptors (TLRs) recognize antigens produced by infection or injury to induce innate immunity via cell surface or endocytic pathways. TLR4 sequentially triggers both pathways, leading to TLR4 activation of the pro-inflammatory NF-kB pathway from the cell surface followed by dynamin-mediated TLR4 endocytosis, activation of TRIF and production of anti-inflammatory IRF (Interferon Regulatory Factor)3-regulated genes. We found that myeloid cell surface peptidase CD13 regulates TLR4 signal transduction by controlling dynamin-dependent endocytosis. In response to LPS, CD13KO DCs showed enhanced activation of IRF3, increase in its target gene IFN-β and inducible nitric oxide activity in a dynamin dependent manner. Endogenous TLR4 ligands produced in response to ischemic injury provoked hyperactivation of pIRF3 and its target cytokines in CD13KO animals. CD13KO DCs internalize higher levels of cell-associated TLR4 ligands released by dying cells or the TLR4 ligand LPS, indicating that CD13 regulates inflammatory TLR4 responses in vivo by modulating DC antigen uptake. Our results further suggest that CD13 and the LPS binding protein, CD14, may potentially act as opposing regulators of TLR4 endocytosis in inflammation. We propose that in response to injury or infection, CD13 serves to balance the immune response by modulating TLR4 induced pro- and anti-inflammatory cytokine profiles and maintain inflammatory equilibrium that is critical to proper wound healing.
A convexity result for fractional differences

Abstract In this brief note we demonstrate that under certain conditions the positivity of the fractional difference Δ 0 μ y ( t ) , for a given function y : N 0 → R and a number μ ∈ ( 2 , 3 ) , implies the convexity of y . This is given as a special case of a more general result. Finally, as a concrete application of this result we demonstrate that a particular class of fractional boundary value problems has no nontrivial positive solutions.
Visual effects of opiates in pigeons: I. Target location in visual search.

Pigeons pecked at target forms, located in arrays of distractors. In experiment 1 the number of distractors and their similarity to the target varied. In experiment 2, similarity was varied over a more extended range. Drug tests used morphine in doses ranging from 1 to 6 mg/kg, naloxone (0.3–3 mg/kg) alone and combined with morphine. Morphine had relatively small effects on accuracy; however, it produced pronounced elevations in reaction time. Significant interactions with display variables indicated a visual component to the morphine effect. Naloxone alone had no effect; naloxone combined with morphine blocked the morphine effect.
Chemistry of sulfonyl isocyanates and sulfonyl isothiocyanates. X. Possible routes to substituted imidazolidinethiones and hexahydropyrimidinethiones

4-Toluenesulfonyl isocyanate (I) reacted with 2-aminoethanol and 3-amino-l-propanol to give 2:1 isocyanate/amino alcohol addition products. 1-Amino-2-propanol and I gave 1:1 and 2:1 adducts while 2-amino-2-methyl-l-propanol afforded only a 1:1 adduct. 4-Toluenesulfonyl isothio-cyanate (III) gave 1:1 adducts with 2-aminoethanol, l-amino-2-propanol and 3-amino-l-propanol, the first two of which were cyclized by concentrated sulfuric acid to 1-(4-toluenesulfonyl)-imidazoline-2-thiones and the third to 1-(4-toluenesulfonyl)hexahydropyrimidine-2-thione. A 1:2 adduct was obtained from III and 2-amino-2-methyl-l-propanol. Amino acids reacted with I and with 4-chlorobenzenesulfonyl isocyanate (II) to give N-(arylsulfonyl)-N1-(carboxylic acid)-ureas. N-(4-Toluenesulfonyl)-N1-(acetic acid)-urea (XVI) was converted to the methyl ester (XIX) by concentrated sulfuric acid and methanol and to water-soluble unrecoverable products by sulfuric acid alone. Glycine and III gave N-(4-toluenesulfonyl)-N1-(acetic acid)-thiourea (XX) which was converted to the methyl ester (XXII) by concentrated sulfuric acid/methanol and to the cyclic 1-(4-toluenesulfonyl)imidazolin-5-one-2-thione (XXI) by sulfuric acid alone.
Finite strain response, microstructural evolution and β→α phase transformation of crystalline isotactic polypropylene

Abstract An experimental study of the finite strain response of annealed α and β crystalline isotactic polypropylene (iPP) was conducted over a range of temperatures (25, 75, 110 and 135 °C) using uniaxial compression tests. Uniaxial compression results indicate nearly identical macroscopic stress vs. strain behavior for α-iPP and for β-iPP to true strains in excess of −1.1 at room temperature despite the different initial morphologies. At larger compressive strains (>1.2), β-iPP shows more rapid strain hardening. The orientation of crystalline planes during straining differs at room temperature from that at high temperature, indicating a change of slip mechanisms as temperature increases. In addition, strain-induced crystallization occurred at the highest temperature examined in α-iPP. A continuous transformation of β crystals to α crystals with inelastic deformation at room temperature was observed and it was facilitated at higher deformation temperatures. Scanning electron microscopy (SEM) observations of deformed β-iPP provide strong evidence that the transformation is achieved via a solid-to-solid mechanism despite the different helical hands in α and β crystal structures. Molecular simulations were used to investigate a conformational defect in the 3 1 helical chains of β-iPP, characterized by a 120° helical jump. The propagation of this conformational defect along molecular chains provides the reversal of helical hand required by the solid-to-solid transformation. The β→α phase transformation in iPP is proposed to be accomplished via a solid transformation that includes slip along β(110) and β(120) planes during shear of the crystal lattice.
Selectively retrofitting monitoring in distributed systems

Current distributed systems carry legacy subsystems lacking sufficient instrumentation for monitoring the end-to-end business transactions supported by these systems. In the absence of instrumentation, only probabilistic monitoring is possible by using time-stamped log-records. Retro fitting these systems with expensive monitoring instrumentation provides high-granularity, precise tracking of transactions. Given a limited budget, local instrumentation strategies which maximize the effectiveness of monitoring transactions throughout the system are proposed. The operation of the end-to-end system is modeled by a queuing network;each queue represents a subsystem which produces time-stamped log-records as transactions pass through it. Two simple heuristics for instrumentation are proposed which become optimal under certain conditions. One heuristic selects states in the transition diagram for local instrumentation in the decreasing order of the load factors of their queues. Sufficient onditions for this load-factor heuristic to be optimal are proven using the notion of stochastic order. The other heuristic selects states in the transition diagram based on the approximated tracking accuracy of probabilistic monitoring at each state, which is shown to be tight at low arrival rates.
Defect dynamics and the properties of amorphous silicon

Abstract It is shown that self-mobility of intrinsic defects is essential in describing the reactions that underlie a wide assortment of phenomena in a-Si. A set of basic reactions involving the primitive intrinsic defects (dangling and floating bonds), hydrogen, and dopant impurities are capable of describing all the observed phenomena that involve atomic rearrangements, e.g., defect creation and annealing, hydrogenation, hydrogen diffusion and evolution, coordination changes underlying doping, etc. Interconversion between the two primitive intrinsic defects leads to processes that are unique to the amorphous state.
Study of Inverse Isotope Dilution Analyses of Chlortetracycline

Chlortetracycline was quaternized using carbon14-labeled methyl iodide of known specific activity. The resulting radioactive chlortetracycline methiodide was diluted by the addition of a known amount of nonradioactive chlortetracycline methiodide. The specific activity of a purified portion of the mixture was then determined. From these data, the quantity of chlortetracycline originally present was calculated. The developed procedure was applied to the determination of microgram quantities of chlortetracycline in blood.
Spin Mount System - A Test System For An Infrared Sensor

The spin mount system for testing an infrared sensor assembly is a state-of-the-art test facility in which cryogen (gaseous helium at 5 K) is fed through a unique rotary coupling to a rotating infrared detector. The system is rotationally stable about its spin axis to less than +10 microradians while operating at 1500 rpm in air or vacuum, with cryogen flowing. Optical techniques are used to monitor the dynamic motion of the rotor. The project was sponsored by AEDC, Air Force System Command, USAF, Arnold Air Force Station, TN 27289, under Contract No. F40600-81-C-0015.© (1984) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Solution Structure of xDNA: A Paired Genetic Helix with Increased Diameter

We describe the structure in aqueous solution of an extended-size DNA-like duplex with base pairs that are approximately 2.4 A longer than those of DNA. Deoxy-lin-benzoadenosine (dxA) was employed as a dA analogue to form hydrogen-bonded base pairs with dT. The 10mer self-complementary extended oligodeoxynucleotide 5'-d(xATxAxATxATTxAT) forms a much more thermodynamically stable duplex than the corresponding DNA sequence, 5'-d(ATAATATTAT). NMR studies show that this extended DNA (xDNA) retains many features of natural B-form DNA, but with a few structural alterations due to its increased helical diameter. The results give insight into the structural plasticity of the natural DNA backbone and lend insight into the evolutionary origins of the natural base pairs. Finally, this structural study confirms the hypothesis that extended nucleobase analogues can form stable DNA-like structures, suggesting that alternative genetic systems might be viable for storage and transfer of genetic information.
Stabilization of neurofilaments by vincristine sulfate in low ionic strength media.

In vitro alterations of neurotubules and neurofilaments from rat peripheral nerve were studied following manipulations of the ionic content of the incubational media with and without the addition of mitotic spindle inhibitors. Immersion of fresh tissue in graded solutions of lowering ionic concentrations resulted in a progessive dissolution of neurotubules and neurofilaments and a corresponding increase of protein released from the tissue. Addition of vincristine to the incubational media induced formation of microtubular crystals and prevented the structural disruption of neurofilaments in low ionic strength media. Both vincristine-altered neurofilaments and microtubular crystals showed an affinity for heavy metallic stains and possessed similar stabilization characteristics. The similar physical properties exhibited by these structures suggested the presence of microtubular protein within the neurofilaments as well as in the microtubular crystals.
High strain rate deformation of Mo and Mo-33re by shock loading: Part II. Rates of defect generation and accumulation of plastic strain

The kinetics of plastic flow in Mo and Mo-33Re under shock loading conditions has been examined by characterizing the substructure quantitatively and relating these observations to defect generation rates and the dynamic strength of the materials. The finite dislocation generation rates, apparently limited to the order of 10 21 m−2 s−1 result in a maximum plastic strain rate on the order of 10 6 s−1 and a maximum dislocation velocity of ∼3 x 10 2 m s−1. The maximum shear stress imposed on the materials is estimated to be ∼µ/50, at short pulse durations. The estimated shear stresses, dislocation velocities, and production of dislocations as a function of strain are found to be consistent with conventional deformation mechanisms, and require no novel material behavior such as homogeneous nucleation of dislocations or supersonic dislocation velocities.
Distance Functions and Almost Global Solutions of Eikonal Equations

Consider a function u defined on  n , except, perhaps, on a closed set of potential singularities . Suppose that u solves the eikonal equation ‖Du‖ = 1 in the pointwise sense on  n \, where Du denotes the gradient of u and ‖·‖ is a norm on  n with the dual norm ‖·‖∗. For a class of norms which includes the standard p-norms on  n , 1 < p < ∞, we show that if  has Hausdorff 1-measure zero and n ≥ 2, then u is either affine or a “cone function,” that is, a function of the form u(x) = a ± ‖x − z‖∗.
A family study of psychiatric comorbidity in girls and boys with attention-deficit/hyperactivity disorder

Abstract Background: Because attention-deficit/hyperactivity disorder (ADHD) is relatively infrequent among girls, little is known about the nature and causes of psychiatric comorbidity in girls and the reason for gender differences in the prevalence of these comorbidities. Methods: Using blinded, structured psychiatric interviews, we studied two groups of boys: 140 ADHD probands and 120 non-ADHD comparisons. These groups had 454 and 368 first-degree biological relatives, respectively. We also studied two groups of girls: 140 ADHD probands and 122 non-ADHD comparisons. These groups had 417 and 369 first-degree biological relatives, respectively. Results: The co-occurrence of ADHD and comorbid psychopathology in families was the same for families ascertained through boy and girl probands. Conclusions: Our results suggest that boys and girls do not differ in the familial risk factors that mediate comorbid psychopathology and the familial aggregation of comorbid disorders in ADHD families. Although this is consistent with prior work suggesting more similarities than differences in the nature of psychiatric comorbidity in ADHD boys and girls, we cannot make strong conclusions, owing to the possibility of cohort effects.
Pearls From Bones: Relics, Chortens, Tertons and the Signs of Saintly Death in Tibet

Summary Although there has been much work, in recent years, on the sacrum of Christianity, and some important studies have appeared on Buddhist relic cults and related facets of Buddhism, so far very little has been written on Tibetan Buddhist relics. This paper, while offering some material for a historical perspective, mainly seeks to find a larger cultural pattern for understanding the interrelationships of a complex of factors active in Tibetan religious culture. Beginning with problems of relic-related terms and classifications, we then suggest a new assessment of the role of the Terton ('treasure revealer'). Then we discuss 'miracles' in Tibet, and the intersection of categories of 'signs of saintly death' and relics. Much of the remaining pages are devoted to those items that fall within both categories, specifically the 'pearls' that emerge miraculously from saintly remains and images that appear in bodily or other substances connected with cremations. After looking at a number of testimonials on these miraculous relics, we examine the possibility that these items might be 'deceitfully manufactured', looking at a few Tibetan polemical writings which raise this possibility. In the conclusion, we suggest that there are some critical links between three spheres of Tibetan religiosity: 1. sacrum which are not relics, 2. relics, and 3. signs of sainthood. Finally, we recommend an approach to religious studies that takes its point of departure in actual practices, and particularly the objects associated with popular devotional practice.
Structure and free energy of complex thermodynamic systems

Abstract Biological systems are intrinsically complex, involving many degrees of freedom, heterogeneity, and strong interactions among components. For the simplest of biological substances, e.g., biomolecules, which obey the laws of thermodynamics, we may try to investigate them by means of a statistical mechanical approach. Even for these simplest many-body systems, assuming all microscopic interactions are completely known, current physical and chemical methods of characterizing the overall structure and free energy face the fundamental challenge of an exponential amount of computations as the number of degrees of freedom of these systems increases. As a response to this problem, two general procedures have been developed to compute the structure (Monte Carlo-minimization method) and free energy (Monte Carlo recursion method) of a complex thermodynamic system. The Monte Carlo-minimization procedure has been applied to determine the structure of a pentapeptide Met-enkephalin, leading consistently to a stable β-bend structure, starting from random initial conformations. The Monte Carlo recursion method has been applied to a Lennard-Jones fluid, with results in agreement with previously published values of the free energy obtained from other procedures.
Incorporation of 14C-amino-acids by malaria (Plasmodium lophurae) IV. In vivo utilization of host cell haemoglobin

Abstract 1. 1. The avian malarjal parasite. Plasmodium lophurae , was grown in vivo through one asexual cycle m duck erythrocytes containing radioactive haemoglobin. 2. 2. Radioactivity was recovered in the parasite proteins (uncontaminated by host cell haemoglobin or malaria pigment), thus demonstrating the in vivo utilization of host cell haemoglobin by the malaria parasite for synthesis of plasmodial proteins.
The effect of calcium chloride on several α-chymotrypsin-catalyzed hydrolyses

Abstract The extent to which the reactivity of systems containing α-chymotrypsin and specific substrates of this enzyme may be enhanced by the presence of calcium chloride has been shown to be dependent not only upon the concentration of this salt but also upon the nature and/or concentration of several buffer components. An additional dependence upon the nature of the specific substrate has not been excluded.
Will We Hit a Wall? Forecasting Bottlenecks to Whole Brain Emulation Development

Whole brain emulation (WBE) is the possible replication of human brain dynamics that reproduces human behavior. If created, WBE would have significant impact on human society, and forecasts frequently place WBE as arriving within a century. However, WBE would be a complex technology with a complex network of prerequisite technologies. Most forecasts only consider a fraction of this technology network. The unconsidered portions of the network may contain bottlenecks, which are slowly-developing technologies that would impede the development of WBE. Here I describe how bottlenecks in the network can be non-obvious, and the merits of identifying them early. I show that bottlenecks may be predicted even with noisy forecasts. Accurate forecasts of WBE development must incorporate potential bottlenecks, which can be found using detailed descriptions of the WBE technology network. Bottlenecks identification can also increase the impact of WBE researchers by directing effort to those technologies that will immediately affect the timeline of WBE development.
Maternal health in developing countries

This is the first chapter in the ‘information for action issue paper’, ‘Improving Maternal Health in Developing Countries’, prepared for UNICEF by the World Federation of Public Health Associations. The remaining chapters in this paper are entitled: Program actions to improve maternal health, Access to Maternal Health Services, Planning and Monitoring Maternal Health Services. There are four appendices: Appendix A describes the value of training Traditional Birth Attendants; Appendix B reviews the maternal child birth record cards available in some countries; Appendix C describes the ‘Programmes to improve maternal health’ in developing countries; and Appendix D contains an annotated bibliography of 25 relevant books and papers, and a bibliography of 155 references. This issue paper is available from APHA Publication Sales, 1015 15th Street, NW Washington, DC 20005, USA at a cost of $9 (there are reductions for bulk orders).
Phenocrysts versus xenocrysts in the youngest Toba Tuff: Implications for the petrogenesis of 2800 km3 of magma

The petrogenesis of the 2800 km 3 of magma erupted as the youngest Toba Tuff has been investigated using experimental petrology and 40 Ar/ 39 Ar dating of biotite, sanidine, hornblende, and plagioclase from the tuff. We find that hornblende does not crystallize experimentally from the magma at temperatures and pressures indicated by the natural mineral assemblage. Hornblende is also not in isotopic equilibrium with biotite and sanidine, both of which grew experimentally. Hornblende thus appears xenocrystic, despite being a major phase in the tuff. Some plagioclase is also xenocrystic, on the basis of Ar isotopes, but others are probably phenocrystic, because plagioclase grew experimentally. Crystal clots of hornblende + plagioclase observed in the tuff suggest that the xenocrysts came from a common source, which was at least 1.5 Ma (the oldest hornblende 40 Ar/ 39 Ar age). Our results suggest that the Toba Tuff magma resided at nearly water-saturated pressures of 100–150 MPa and that xenocrysts were entrained as recently as 10 yr before the eruption. The ubiquitous presence of hornblende in the tuff indicates that entrainment occurred throughout the 2800 km 3 of magma.
Partial oxidation of alcohols to produce hydrogen and chemicals in millisecond-contact time reactors

We compare the autothermal partial oxidation of 1-propanol and 2-propanol with methanol and ethanol on Rh with several additives in short-contact time reactors. All alcohols could produce H2 at 70–90% selectivity, and Rh–Ce was superior to Rh in producing H2. Methanol produced high conversion and high selectivity to H2 even at high C/O where temperatures fell to <600 °C. 2-Propanol gave lower conversions and less H2 and CO than the other alcohols, but produced the most chemicals. Above C/O = 1.5, ∼70%∼70% of 2-propanol was converted into acetone or propylene. Up to 20% propylene was formed at C/O = 1.5. In contrast, 1-propanol gave <8% propylene and <15% propanal at any C/O and produced more ethylene than propylene. Much more oxygenates and olefins were formed on Rh than on Rh–Ce. These results show that different alcohols have very different selectivity in catalytic partial oxidation at short contact times even at high temperatures. Rapid adsorption of alcohols as alkoxy species leads to complete dissociation to H2 and CO. Our results suggest that acetone and olefins likely were produced primarily by homogeneous reactions after all O2 had been consumed in the catalyst. Although alkanes do not form significant oxygenates by partial oxidation at short contact times, alcohols can be made to produce predominantly oxygenates through suitable adjustments of C/O and catalyst.
Synthesis and Crystal Structure of a Dinuclear Palladium Complex Containing C,O-Bridging Ester−Enolato Moieties

Palladium ester enolates have been prepared and characterized using IR, NMR, and single-crystal X-ray diffraction techniques. The X-ray diffraction established a dimeric crystal structure for complex {[N∧N]PdCH2C(O)OCH3}2 (N∧N = 1-[1-(5-methylpyrrole-2-yl)ethylidne]amino-2,6-diisopropylbenzene), 2, which contains C,O-bridging enolato groups. Upon reaction with donor molecules (acetonitrile, phosphines), the dimeric 2 cleaves to form monometallic C-bound enolate complexes, 3‘ and 4.
Dynamics of sediment discharge in relation to land-use and hydro-climatology in a humid tropical watershed in Costa Rica

Abstract Hydrology in humid tropical regions is often characterized by considerable natural variability and uncertainty. Hydrologic and land-use data from the Terraba basin in Costa Rica are used to analyze dynamics in sediment discharge processes during the period 1971–1993. Time-series of log transformed sediment concentration and flow are analyzed with a Bayesian dynamic linear regression model (DLM) to detect changes in the sediment–flow relationship over time. Annual time-series of estimated sediment discharge based on the DLMs were regressed against various hydro-climatic variables based on the Southern Oscillation Index (SOI), rainfall, stream flow and rainfall erosivity. Hydro-climatic variables such as rainfall, stream flow and rainfall erosivity were also regressed against SOI. The results from the regression models, the presence of trends in the DLM slope and other hydro-climatic parameters for each sub-basin were used to compare the hydro-climatic and sediment response characteristics of the sub-basins. Over 60% of the variability in hydro-climatic variables like rainfall, rainfall erosivity and stream flow is explained by SOI but less than 40% for sediment discharge measured at the basin mouth. The clustering of stations and sub-basins with respect to sediment discharge responses is different from that based on hydro-climatic characteristics. Stations or sub-basins corresponding to areas with large rates of deforestation and/or agricultural intensification and earthquake related soil disturbance tend to fall in one cluster. These sub-basins are characterized by an increase in the sediment–flow regression slope over time, and weaker relationship between sediment discharge and hydro-climatic variables such as SOI, rainfall and flow. In sub-basins undergoing rapid land-surface changes, variability in sediment supplies accounted for an estimated 50–90% of the variability in annual sediment discharge. The methods described in this paper can be used to analyze many existing hydrologic time-series to detect land-use effects on watershed hydrology.
The role of antiarrhythmic drugs in sudden cardiac death

Antiarrhythmic drugs may either decrease or increase the likelihood of ventricular fibrillation. Although reliable data suggest reasonable mechanisms for the antiarrhythmic action of several drugs, much less information is available to indicate the mechanisms by which drugs are arrhythmogenic. Antiarrhythmic action may result from suppression of precipitating events such as inappropriately timed premature impulses or runs of excessively rapid impulses and from modification of the conditions predisposing to random reentry. Increases in the likelihood of fibrillation may result from opposite effects on precipitating events or from drug-induced increase in the likelihood of random reentry. One factor that very likely is involved in the latter is the presence of local differences in the electrical activity of myocardial cells that cause significant local differences in the tonic and use-dependent actions of antiarrhythmic drugs.
An observation of the gulf stream surface front structure by ship, aircraft, and satellite

Evaluation of observations of surface temperature and salinity along the western edge of the Gulf Stream made from a ship and of concurrent temperature observations obtained by instrumented aircraft at six altitudes. The major feature along a five-kilometer line normal to the Stream's edge is a temperature gradient of about 0.75 C/kilometer within which are embedded two abrupt temperature increases of about 1.5 C. Temperature variations were compensated by salinity variations, yielding nearly constant density through the frontal zone; a sharp lateral current shear was associated with the thermohaline mixing region between the steps. The attenuation of surface temperature measured by the airborne radiometer was compared with a theoretical model. The analysis supports the view that a two-part correction technique is required: one part for bulk-skin temperature differences, and another for atmospheric attenuation of sea surface emission due to the mass and temperature of interfering gases.
The development of discourse markers in peer interaction

Abstract Discourse markers are linguistic elements that signal relations between units of talk, relations at the exchange, action, ideational, and participation framework levels of the discourse (Schiffrin, 1987). To what extent do young children use markers in these ways, indexing their ability to differentiate these levels of talk? Four- and seven-year children were paired in best-friend dyads and observed interacting in two activity contexts: pretend play with a scenario toy, and story re-telling, in which one child was read a story and retold the story to the friend on another day. Different activity contexts promoted different uses of markers. Moreover, children at the two ages differed in the activity contexts they preferred and experienced in their social life with peers. These two factors help explain developmental changes in uses of markers.
Structure of the Substrate Binding Pocket of the Multidrug Transporter EmrE: Site-Directed Spin Labeling of Transmembrane Segment 1†

Site-directed spin labeling (SDSL) was used to explore the structural framework responsible for the obligatory drug-proton exchange in the Escherichia coli multidrug transporter, EmrE. For this purpose, a nitroxide scan was carried out along a stretch of 26 residues that include transmembrane segment 1 (TMS1). This segment has been implicated in the catalytic mechanism of EmrE due to the presence of the highly conserved glutamate 14, a residue absolutely required for ligand binding. Sequence-specific variation in the accessibilities of the introduced nitroxides to molecular oxygen reveals a transmembrane helical conformation along TMS1. One face of the helix is in contact with the hydrocarbon interior of the detergent micelle while the other face appears to be solvated by an aqueous environment, resulting in significant exposure of the nitroxides along this face to NiEDDA. TMS1 from two different subunits are in close proximity near a 2-fold axis of symmetry as revealed by the analysis of spin-spin interactions at sites 14 and 18. The limited extent of spin-spin interactions is consistent with a scissor-like packing of the two TMS1. This results in a V-shaped chamber which is in contact with the aqueous phase near the N-terminus. The spatial organization of TMS1, particularly the close proximity of E14, is consistent with a proposed mechanistic model of EmrE [Yerushalmi, H., and Schuldiner, S. (2000) Biochemistry 39, 14711-14719] where substrate extrusion is coupled to proton influx through electrostatic interactions and shifts of the glutamate 14 pK(a) during the cycle.
Equivalent radiolarian ages from ophiolitic terranes of Cyprus and Oman

Radiolarian biostratigraphy shows that umberiferous strata overlying the Troodos ophiolite in Cyprus are Turonian in age and are thus essentially contemporaneous with similar strata that overlie the Samail ophiolite in Oman. However, this radiolarian age is markedly older than Campanian isotopic ages measured on the underlying rocks of the Troodos ophiolite. The revised age for the umbers indicates that the Troodos lavas were formed no later than Turonian time. The presence of overlying autochthonous Maastrichtian chalks restricts the emplacement of the Troodos ophiolite to the Late Cretaceous (Santonian to early Maastrichtian).
The association between innate immunity gene (IRAK1) and C-reactive protein in the Diabetes Heart Study.

Evidence suggests that interleukin-1 receptor associated kinase-1 (IRAK1), fundamental in the toll-like receptor pathway (TLR), may play a more specific role in atherosclerosis. Methods Caucasian women (N=529) and men (N=467) from the Diabetes Heart Study (DHS) were genotyped at four loci within the IRAK1 gene located on the X chromosome. Generalized estimating equations (GEE1) were used to evaluate association with C-reactive protein (CRP) for both single SNP and haplotype analyses.
Fibronectin is deposited by injury-activated epicardial cells and is necessary for zebrafish heart regeneration

Unlike adult mammals, adult zebrafish vigorously regenerate lost heart muscle in response to injury. The epicardium, a mesothelial cell layer enveloping the myocardium, is activated to proliferate after cardiac injury and can contribute vascular support cells or provide mitogens to regenerating muscle. Here, we applied proteomics to identify secreted proteins that are associated with heart regeneration. We found that Fibronectin, a main component of the extracellular matrix, is induced and deposited after cardiac damage. In situ hybridization and transgenic reporter analyses indicated that expression of two fibronectin paralogues, fn1 and fn1b, are induced by injury in epicardial cells, while the itgb3 receptor is induced in cardiomyocytes near the injury site. fn1, the more dynamic of these paralogs, is induced chamber-wide within one day of injury before localizing epicardial Fn1 synthesis to the injury site. fn1 loss-of-function mutations disrupted zebrafish heart regeneration, as did induced expression of a dominant-negative Fibronectin cassette, defects that were not attributable to direct inhibition of cardiomyocyte proliferation. These findings reveal a new role for the epicardium in establishing an extracellular environment that supports heart regeneration.
Nickel-alumina interfacial fracture toughness: experiments and analysis of residual stress effects

The purpose of the present work is to account for the influence of residual stresses on the measured fracture toughness of a representative metal-ceramic system and, in conjuction with a maximum hoop stress criterion, to explain the observed increase in toughness with increasing mixity of loading. For the sandwich specimen geometry adopted in the current study, a simple argument yields a critical layer thickness below which residual stress effects are expected to be minimized. The measured fracture toughness is found to be independent of thickness for thicknesses below this threshold. For such specimens a general result is demonstrated: compared to the same loading without residual stresses present, the effect of residual stresses is to decrease the magnitude of the phase angle of the stresses which develop along the interface. It is argued that when small-scale yielding conditions hold, both the mixity and the critical hoop stress corresponding to fracture should be reported at a length which falls within the κ-dominant region in the sample. In this manner, good quantitative agreement between theory and experiment is demonstrated.
Utility of color flow imaging for visualizing shunt flow in atrial septal defect

Color flow imaging provides visualization of intracardiac blood flow. The usefulness of this technique was evaluated in 93 patients with atrial septal defect. Color flow imaging improves the sensitivity of two-dimensional Doppler echocardiography in the diagnosis of atrial septal defect. In addition, it enhances communication between the cardiologist and the cardiovascular surgeon.