cssi/SciSciGPT-SciSciNet huggingface dataset:
Rayleigh wave phase velocities for the path Addis Ababa-Nairobi

Abstract Rayleigh wave phase velocities have been obtained for the path Addis Ababa-Nairobi in the period range 20–125 sec. The phase velocities are low over the entire range when compared with most other parts of the world. The phase velocities are the same as for the Great Basin of the western United States. Inversion has been made by the “hedgehog” method. Probably the mantle has an S n velocity of between 4.25 to 4.45 km/sec extending to depths of perhaps 120–200 km below the crust. A thin high velocity veneer at the top of the mantle is not excluded by our data.
How Annealing Affects the Desorption Kinetics of CO on Ni(100)

The impact of annealing on the kinetic parameters for CO desorption from Ni(100) was investigated using isotopic mixing, temperature-programmed desorption (TPD), and work function Δφ measurements. ...
In Defense of the Playoff System

According to some philosophers of sport, the decision to use a playoff system in American sports is driven more by the desire to maximize profits than to determine the most talented player or team in a given sport. In “On Winning and Athletic Superiority,” for example, Nicholas Dixon claims that the playoff system is not the best measure of athletic excellence, even though it may be a good means for increasing the entertainment value of sports (1). According to Dixon, the best way to measure athletic excellence is to use a system, such as a season long championship, that “minimizes the impact of unjust results in individual games due to such factors as poor refereeing, cheating, gamesmanship, and bad luck” (1: p. 232). In a playoff system, as Dixon points out, it is quite possible that the “best” team does not actually win the championship since the result of any particular game may hinge on factors not directly related to athletic superiority. While a team might play better during postseason playoffs, this does not justify the claim that it is the best team of the year. Yet, in some sports, such as NFL football, the winner of the playoffs is dubbed the “best team of the year” even though it might not truly deserve the title. Playoff games, Dixon admits, can be very exciting and suspenseful, and therefore financially rewarding for sports organizations, but they are not the best measure of athletic excellence. Thus, Dixon suggests that we “reexamine our attitude toward the playoff system in American professional sport” (1: p. 231). Following Dixon’s lead, William Morgan argues that the desire for profit in American professional sports leads to a deterioration of athletic excellence. Speaking of the choice of a playoff system, Morgan infers that the primary motivation is financial because “the allure of the playoffs is that they attract large audiences and, in turn, large television revenues” (4: p. 28). If professional sports leagues, in other words, were concerned with improving the quality of play, they should choose a system that fosters athletic excellence rather than a system that produces fan excitement. In this paper, I offer a defense of the playoff system in response to the arguments of Dixon and Morgan. As I see it, Dixon and Morgan convincingly argue that our current attitudes toward the playoff system require adjustment and revision. However, when it comes to making institutional changes, whether on a professional or amateur level, their arguments fall short. More specifically, I argue that Dixon and Morgan have a too cynical view of the playoff system in that they believe that the choice to use a playoff system is motivated simply by the desire
Fourth Grade Students Reading Block-Based Programs: Predictions, Visual Cues, and Affordances

Visual block-based programming environments allow elementary school students to create their own programs in ways that are more accessible than in textual programming environments. These environments help students write code by removing syntax errors and reducing typing. Students create code by dragging, dropping, and snapping constructs together (e.g. blocks) that are organized by lists, colors, shape, images, etc. However, programming in visual block-based environments is not always simple; in fact, it can become complex quickly. In addition to elements that create code, the visual aspects of these environments provide readers information about what happens, when, and how. Here, we focus on how students used visual cues when reading programs in our block-based programming environment, LaPlaya, a variant of Scratch. Specifically we identified the visual cues students noticed and acted upon. These included not only those that were intended by designers (perceptible affordances), but also those that were not intended by designers (false affordances). Through a detailed content analysis of 13 focus groups with fourth graders we created an initial taxonomy of visual cues in our programming environment and explored how students used these cues to make predictions about provided code, and the types of affordances such cues offered students.
TGF-β Signaling, Tumor Suppression, and Acute Lymphoblastic Leukemia

Dr. James R. Downing describes the transforming growth factor β signaling pathway that supresses the early development of cancer cells. There is mounting evidence of a permissive role of TGF-β in t...
High Body Temperature of Pigeons and Sparrows As a Factor in Their Resistance to an Agent of the Psittacosis Group

It had been previously observed that large doses of a highly virulent, avian isolate of the psittacosis-LGV-trachoma (PLT) group of organisms originally recovered from turkeys failed to affect pigeons and sparrows while readily producing lethal infections in a variety of other birds and mammals (Page, 1965). On the suspicion that the unusually high normal body temperature (43 ± 0.5°C) of pigeons and sparrows might be a factor in the resistance of these birds to this PLT isolate, the in vitro rates of inactivation at 43 °C of the organisms infectivity for chicken embryos and the toxicity for mice were determined in comparison with an isolate of a strain normally found in pigeons and which causes disease in pigeons and sparrows. Growth rates of both isolates at 43 °C in cultures of mebryonic chicken tissues were also compared. The turkey isolate was inactivated in vitro at a consistently rapid rate at 43 °C while the pigeon isolate was relatively resistant to 43 °C inactivation. Both isolates failed to mult...
Resource allocation in a social wasp: effects of breeding system and life cycle on reproductive decisions

Organisms must make important decisions on how to allocate resources to reproduction. We investigated allocation decisions in the social wasp Vespula maculifrons to understand how social insects make reproductive choices. We first determined how annual colonies apportioned resources to growth and reproduction by analysing developing brood. In contrast to expectations, colonies invested in both growth (workers) and reproduction (males) simultaneously. In addition, colonies showed evidence of producing males in pulses and reversing their reproductive choices by decreasing investment in males late in the season. This reversal is consistent with theory suggesting that colonies decrease production in males if fitness of late emerging males is low. To further investigate reproductive decisions within colonies, we determined if the male mates of multiply-mated queens varied in their reproductive success over time. Sperm use by queens did vary over time suggesting that male success may depend on sperm clumping within the female reproductive tract. Finally, we tested if colony sex ratio conformed to expectations under kin selection theory that nestmate relatedness would positively correlate with investment in new queens if workers controlled sex allocation. Surprisingly, the proportion of queens produced by colonies was negatively correlated with nestmate relatedness, suggesting that allocation may be shaped by advantages arising from increased genetic diversity resulting from multiple mating by queens. Overall, our study suggests that the reproductive decisions of colonies are flexible and may depend both on environmental cues arising from energetic needs of the colony and genetic cues arising from mating behaviours of queens.
Chemoselective ligation reactions with proteins, oligosaccharides and cells

Traditional chemical synthesis does not lend itself to the easy, rapid construction of even moderately sized biomolecules, because it requires elaborate protection schemes. Furthermore, many biological studies would be aided by the ability to assemble biomolecules under physiological conditions. These challenges have motivated the development of chemoselective ligation, the selective covalent coupling of mutually and uniquely reactive functional groups under mild, aqueous conditions. This technique has attracted significant attention recently for the synthesis of biological macromolecules of defined homogeneous composition, the design of self-assembling drugs and the chemical remodeling of cell surfaces.
New insights on the functions of the guanylyl cyclase receptors

The discovery of at least 29 genes encoding putative guanylyl cyclases in Caenorhabditis elegans has raised the question as to whether there are numerous receptors yet to be discovered in the mammal. The nematode, however, not only seems ideal to study guanylyl cyclase receptor localization and function, given the large variety of isoforms, but also leads to possible identification of ligands for orphan guanylyl cyclases by the use of genetic and behavioral assays. A recent powerful approach to describe the function of different guanylyl cyclase isoforms in mammals has been the disruption of the corresponding genes in the mouse. A salt resistant elevation of blood pressure, which corresponds to the phenotype of 50% of all human patients with essential hypertension, is observed in mice lacking the GC-A-receptor. Mice missing the GC-C receptor have been shown to be resistant to STa, an E. coli heat-stable enterotoxin, which is largely responsible for travellers diarrhea in adults and mortality due to diarrhea in infants.
Instructed versus shaped human verbal behavior: Interactions with nonverbal responding.

Undergraduate students' presses on left and right buttons occasionally made available points exchangeable for money. Blue lights over the buttons were correlated with multiple random-ratio random-interval components; usually, the random-ratio schedule was assigned to the left button and the random-interval to the right. During interruptions on the multiple schedule, students filled out sentence-completion guess sheets (e.g., The way to earn points with the left button is to...). For different groups, guesses were shaped with differential points also worth money (e.g., successive approximations to "press fast" for the left button), or were instructed (e.g., Write "press slowly" for the left button), or were simply collected. Control of rate of pressing by guesses was examined in individual cases by reversing shaped or instructed guesses, by instructing pressing rates, and/or by reversing multiple-schedule contingencies. Shaped guesses produced guess-consistent pressing even when guessed rates opposed those characteristic of the contingencies (e.g., slow random-ratio and fast random-interval rates), whereas guesses and rates of pressing rarely corresponded after unsuccessful shaping of guesses or when guessing had no differential consequences. Instructed guesses and pressing were inconsistently related. In other words, when verbal responses were shaped (contingency-governed), they controlled nonverbal responding. When they were instructed (rule-governed), their control of nonverbal responding was inconsistent: the verbal behavior sometimes controlled, sometimes was controlled by, and sometimes was independent of the nonverbal behavior.
A Phantom Doctrine: The Origins and Effects of Just v. Marinette County

No branch of zoning law is more perplexing than the constitutional limits of the police power. How severely may the government reduce the value of land by regulation without compensating the owner? This issue has become particularly prominent during the last decade, as state and local governments have sought to preserve the landscape by novel and sometimes stringent land-use controls. Recently, some scholars have suggested that the familiar “diminution-of-value” test for determining when regulations become unconstitutional should be abandoned, even in cases where the prohibited use is not akin to a nuisance, and the effect of the regulation is to render the tract worthless. In Just v. Marinette County, the Wisconsin Supreme Court seemed to adopt this idea, declaring that development of a shoreland marsh may be forbidden irrespective of the economic impact on the landowner. Naturally, such decisions create the impression that property owners are regularly being sacrificed for the sake of environmental quality. But a study of Just's origins and effects reveals that in Wisconsin and Minnesota this impression of regulatory zeal is inaccurate. As a rule, all four of the counties studied allowed owners of shoreland marshes to fill enough of the marsh to make a remunerative use of the tract. Their main concern was not to preserve marshes but rather to attach erosion-control conditions to the fill permits. Cases in which a county, by denying a fill permit, drastically reduced the value of the land, have been extremely rare, even in the three Wisconsin counties studied, where under Just such denials are clearly constitutionally permissible. In these counties, it appears that ideology and politics, not constitutional law, are the major factors limiting the severity of conservancy zoning and consequently the extent to which this technique preserves open space. In jurisdictions where this is so, it seems likely that judicial decisions that permit the government to prohibit all remunerative uses are more likely to rationalize unjust treatment of an occasional landowner than to make a major contribution toward preserving environmental quality.
Influence of oxygen on the wear of silicon

Abstract The results of a series of wear tests on semiconductor silicon chips are presented. In these tests, hemispherical anodized aluminum sliders rubbed against flat silicon specimens with a small-amplitude oscillatory motion. The influence of several parameters, including the load, the slider roughness, the type of anodization, the contact geometry, the environment and the initial condition of the silicon surface, on the wear of the silicon was studied. Of these the influences of the environment and the initial condition of the silicon surface were most pronounced. It was concluded that oxide formation and growth on the silicon were important factors in the wear of the silicon and tended to increase the wear. It was also concluded that the primary wear mechanism of the silicon for low load is probably delamination or surface fatigue.
Indo‐guyanese migration: From plantation to metropolis

Like other themes in East Indian historiography in the Caribbean, migration since settlement has only recently begun to receive scholarly attention. This article examines Indo‐Guyanese migration and shows that although East Indians display a preference for residing in the countryside since their arrival into Guyana over a 150 years ago, migration has always been a continuous part of their experience. East Indians had to overcome tremendous odds in order to migrate such as the paternalistic structure of the plantation system, limited inter‐territorial opportunities, and marginalization under Forbes Burnham's cooperative socialism. The article concludes by stating that the obstacles to Indo‐Guyanese migration must be viewed as a major constraint on Indo‐Guyanese development.
The American dream of community: An unfinished agenda

Needless to say, I have thought for quite awhile about what I will want to say here this evening, mindful that the critical information of how best to do justice to an occasion such as this will not be available till the occasion has passed. We might call that ex-post facto socialization to distinguish it from its better known cousin. It is an interesting experience to stand before this audience, where fifty-six others before me have symbolically stood-an experience of community in a small way, a community that matters to many of us here, calling forth sentimental associations and reminders of larger goals (with regard to the discipline) and shared, if not common, purposes. It is a blend of individual striving and of a bond to our calling and to each other, a modern version of community if you will, that is the subject of my talk this evening. Ours is an age still in search of community. I say still because this search has been going on for a long time and has not, to judge from various soundings, abated. It is not always clear whether community here refers to a place or a state of mind or the two together, but the quest is real, earnest, and elusive. Nor is it particularly novel, having characterized utopian efforts throughout the ages, especially ages of anxiety such as ours. Indeed, the present search for community harks back to the nineteenth century when, in the face of rapid urbanization, one idea of community was dying and no other had yet emerged to take its place. This led human beings to construct an ideal (because lost) past or to design an ideal (because unrealized) future. What is new for our time is that the search for the good community has become second to the search for any community. For as we shall note at several points along the way, American society confronts a paradox. Historically, the culture has emphasized the language of individualism, laissez faire, and private property; it has valued the idea of
Statistical Analysis of Digital Phase-Locked Loops Fading Channiels

Statistical analyses of zero-crossing sampling first- and second order digital phase-locked loops in fading channls (DPLFC) are presented. A DPLFC is defined as one where the incoming signal is not only corrupted by additive Gaussian noise channel (AGN) but also by a fading communication channel. The three fading channels considered are the log-normal, Rayleigh, and Rician channels. The performance degradation of the DPLFC operation is characterized by the steady-state phase-error process probability density function and phase-error variance. Approximate analytic expressions for the phase-error statistics of a first-order DPLFC for both phase-step and frequency-step inputs are obtained by solving the Chapman-Kolmogorov equation associated with the phase-error process. The second-order DPLFC is analyzed for a frequency-step input. Numerical and simulation results are provided confirming the analyses presented for the three fading channels considered.
Emerging roles of health sciences librarians: academic library centrality

The emerging roles of health sciences librarians are considered within the context of changes and challenges facing both the profession of librarianship and the library. Suggests that the emerging – and increasingly relevant – roles of health sciences librarians contribute to the establishment of health sciences libraries’ centrality within their institutions. Rationale is provided for library and information science professionals outside the health sciences arena to maintain awareness of emerging roles, evolving status, and contributions of their colleagues.
Spectral Characteristics of Hayabusa 2 Near-Earth Asteroid Targets 162173 1999 JU3 and 2001 QC34

Reflectance spectra of C-type near-Earth asteroid 162173 1999 JU3 were acquired on UT 2007 July 11, September 10 and 11. An absorption feature centered near 0.7 μm, and associated with the presence of iron-bearing phyllosilicates, is seen in the 2007 July 11 spectrum. The 2007 September spectrum shows a shallow absorption feature centered near 0.6 μm. In contrast, the reflectance spectrum of 162173 1999 JU3 obtained during its discovery apparition has no absorption feature, suggesting that the asteroid's surface covers the conjunction of two different geological units. The variation in the presence and absence of these features in reflectance spectra of the surface material of C-type asteroids is observed among main-belt asteroids. As the target for the planned Japanese mission Hayabusa 2, 162173 1999 JU3 could represent a sample of aqueously altered early solar system material. An alternative target for Hayabusa 2, 2001 QC34, was observed spectrally for the first time. Its reflectance spectrum has characteristics of a Q-class or O-class asteroid.
Properties of the Intermediate State of Actin-Tropomyosin-Troponin

Troponin, tropomyosin and actin form an allosteric regulatory system. This regulated actin stimulates myosin ATPase activity only in the presence of positive effectors. Models of regulation often include 3 states of activity. Calcium causes partial activation and increases the fraction of the intermediate state (C state) to 50–70%. NEM labeled S1 stabilizes the active state (O state) and increases the rate beyond that observed without tropomyosin-troponin.Deleting 14 amino acid residues from the C-terminus of TnT renders regulated actin incapable of entering the inactive state. Thus regulated actin filaments containing Δ14TnT differ from wild type in the following ways: 1) S1-ADP binding is not cooperative. 2) Acrylodan-tropomyosin fluorescence levels in EGTA are uncharacteristic of the inactive state. 3) The normalized ATPase rate in calcium is 37% of the maximum rate compared with 17% for wild type troponin I. That is, filaments with the Δ14TnT mutation spend twice as much time in the active state as wild type actin filaments. 4) The rate of S1 binding is slightly faster in EGTA but not in calcium. In the absence of calcium such actin filaments exist almost totally in the intermediate state (C state) allowing that state to be studied.The lowest measured ATPase activity of S1 in the presence of regulated actin filaments was defined as zero. The fully activated rate in the presence of NEM-S1 was defined as 1. The activity in EGTA with actin filaments containing the Δ14TnT mutant was 1.4% of that of the fully active state. That is, the intermediate state had little ability to activate myosin S1 ATP hydrolysis. Furthermore, virtually all of the regulation of ATPase activity occurred in going from the active state to the intermediate state.
A mother's heart is weighed down with stones: a phenomenological approach to the experience of transnational motherhood.

Although recent scholarship on transnational mothers has rigorously examined the effect of migration on gender constructs and ideologies, it neglects analysis of the lived experience of separated mothers and children. In privileging the exploration of transnational separations through the single analytical lens of gender, such research reduces the embodied distress of mothers and children to mere “gender false consciousness.” This paper calls upon anthropologists to redress this oversight by undertaking a phenomenological analysis of the lived experience of transnational motherhood. Eschewing an analysis of mothers and children as isolated social roles, I show that the suffering of mothers and children is profoundly relational. Through analysis of the narratives of undocumented Salvadoran mothers residing in the U.S., I show how the strain of such mothers’ undocumented status is lived and shouldered within the intersubjective space of the family.
Inheritance of Resistance to Fusarium Wilt in Two Common Bean Races

Fusarium wilt in common bean (Phaseolus vulgaris L.) caused by Fusarium oxysporum Schlechtend. Fr. forma specialis phaseoli Kendrick and Snyder (Fop) occurs worldwide and can result in severe yield loss. Because cultural methods to control disease loss are not completely effective, cultivars with genetic resistance are needed. The objectives of this study were to determine whether genetic control of resistance to Fop race 4 differs between germplasm of races Durango and Mesoamerica of common bean and to estimate heritability of resistance found in race Mesoamerica. Resistant and susceptible lines of races Durango and Mesoamerica were crossed within races to produce F 2 and F 3 progeny. Reaction to Fop was evaluated using a root-dip inoculation method and scored using a CIAT disease severity scale from one to nine. F 2 populations derived from race Durango parents showed a 3:1 (resistant/susceptible) plant segregation ratio, and F 3 progeny tests confirmed that resistance was controlled by a single dominant gene. F 2 data from crosses between parents of race Mesoamerica had continuous distributions for reaction to Fop race 4, suggesting polygenic control of resistance. The narrow-sense heritability estimate derived from midparent-offspring regression of 10 F 2 populations derived from Mesoamerican parents was 0.85 ± 0.34, and realized heritability estimates ranged from 0.25 ± 0.19 to 0.60 ± 0.16 among five populations. The heritability estimates as well as the continuous variation in disease severity observed support the hypothesis that resistance to Fop race 4 among parents of race Mesoamerican is polygenic.
Optimal regulation provision by aluminum smelters

The industrial electrolysis process which is used to produce aluminum is a highly energy-intensive process. As it is possible to adjust the power consumption of this process on short notice without significantly affecting the quality of the aluminum, aluminum smelting plants are able to provide regulation to the electric power grid. In this paper, we focus on determining the optimal regulation capacity that such a manufacturing plant should provide to maximize the combined profit from producing aluminum and providing regulation. The approach is based on stochastic optimization and the stochastic variable is the regulation signal sent to the smelter. Using linear approximations of the high-resolution regulation signal as scenarios, we can reduce the computational burden to solve the associated optimization problem significantly. Simulations for a specific aluminum smelting plant provide insights into the optimal regulation provision by smelters with various cost and price parameters.
Effects of transient propellant dynamics on deployment of large liquid stages in zero-gravity with application to shuttle/centaur

Abstract A common requirement of the Space Station era will be deployment and docking of orbit transfer vehicles with large quantities of liquid propellants. The maneuver will typically start at zero gravity with short, transient accelerations applied to provide accurate vehicle positioning for clearance during deployment or engagement during docking. Since the propellant tanks are not always full and the initial zero-g position of liquid and ullage may not be known, transient fluid forces can have a major influence on vehicle motion. Until recently, this fluid dynamics problem could not be analyzed adequately. This paper describes the application of a recently developed computational fluid dynamics (CFD) program, HYDR-3D, to the analysis of separation of the Centaur G-Prime vehicle from the Space Shuttle Orbiter. The typical application presented illustrates a particularly difficult design task—deployment of a large, liquid-filled, densely packaged vehicle from a manned vehicle. Since it represents a potential catastrophic hazard, a vast number of conditions and parameters must be analyzed to ensure tolerance of at least two credible failures. Validation of the HYDR-3D program against zero- and low-gravity experimental data is also presented. Using the fluid dynamics program, this approach can be used confidently to analyze and determine design requirements for a variety of orbit transfer vehicle/space station deployment and docking problems.
Characterization of the Brassica campestris mitochondrial gene for subunit six of NADH dehydrogenase: nad6 is present in the mitochondrion of a wide range of flowering plants

We have isolated the Brassica campestris mitochondrial gene nad6, coding for subunit six of NADH dehydrogenase. The deduced amino-acid sequence of this gene shows considerable similarity to mitochondrially encoded NAD6 proteins of other organisms as well as to NAD6 proteins coded for by plant chloroplast DNAs. The B. campestris nad6 gene appears to lack introns and produces and abundant transcript which is comparable in size to a previously described, unidentified transcript (#18) mapped to the B. campestris mitochondrial genome. An alignment of NAD6 proteins (deduced from DNA sequences) suggests that B. campestris nad6 transcripts are edited. Southern-blot hybridization indicates that nad6 is present in the mitochondrial genome of all of a wide range of flowering plant species examined.
Atomic branching ratio data for nitrogen-like species

Abstract The branching ratio technique for radiometric calibrations in the vacuum ultraviolet spectral region is briefly reviewed. Lists of transitions suitable for use with the technique are given for nitrogen-like species (N I, O II, and Ne IV) along with pertinent data for their application.
Dynamic Wetting Behavior and Water Drops on Microgrooved Surfaces

The retention of water on the air-side surface of heat exchangers is important in air conditioning, refrigeration, and heat pumping applications. Recently, surfaces with grooves tens to hundreds of micrometers deep and wide have been proven highly effective in promoting water drainage from heat exchangers. Dynamic wetting behavior governs the motion of drops on such surfaces, and this work provides the first data on the dynamic wetting behavior on microgrooved metallic surfaces. Moving drops on microgrooved surfaces can be in a Wenzel or Cassie–Baxter wetting state. In a Wenzel wetting state, drops are elongated and have a tail; the length of the tail increases with Wenzel roughness. In a Cassie–Baxter wetting state, drops become more elongated as the Cassie–Baxter roughness increases. Drops in the Wenzel and Cassie–Baxter wetting states have dynamic advancing contact angles that increase with drop velocity and dynamic receding contact angles that decrease with velocity. In the Cassie–Baxter state, dynami...
Investigating scale-dependent stand heterogeneity with structure-area-curves

Abstract The creation of stands that exhibit characteristics similar to old-growth forests has become one of the most important objectives in forest management and structure has become the tool of choice for evaluating this condition. Attributes of forest structure, however, are extremely heterogeneous and differ considerably in spatial pattern and extent due to the patchy and variable nature of disturbances. Silvicultural research that aims to better understand structural outcomes of natural disturbances must be conducted at spatial scales that are appropriate to capture the variation in both the disturbance regimes and in these structures. Scale-dependent variation in structural attributes, including the index of old-growth ( I og ) and the structural complexity index (SCI), were evaluated in unmanaged mature, transitional, and old-growth Douglas-fir ( Pseudotsuga menziesii (Mirbel) Franco) forests in the south central Cascade Range of Oregon. Moving windows of 100, 500, 1000, 2500, 5000 m 2 were overlain onto stem maps of each of ten 1-ha stands and structural attributes evaluated at each spatial scale. Multiple iterations revealed that structural attributes and indices varied with subplot size, with variation stabilizing with subplots 2500 m 2 and larger. Structural heterogeneity across subplot sizes was consistently highest in old-growth stands. These findings have implications for minimum acceptable plot sizes for research projects that aim to characterize the effect of silvicultural treatments on these structural attributes. For instance, a quarter hectare may be a minimum acceptable plot size to evaluate these structural attributes and potentially even larger plot sizes may be necessary in more complex old-growth forests.
Mode formation and beating in the transverse pattern dynamics in a laser

Abstract Numerical studies of a model introduced by Lugiato, Oldano and Narducci for the interaction among transverse modes in a laser reveal time-dependent solutions in the region of “cooperative frequency locking” (CFL), which are unexpected from linear stability analysis. Spectral analysis reveals that time-dependent solutions are predominantly beating between two CFL solutions. Both CFL solutions and time-dependent solutions coexist stably with a stable plane wave solution in some regions.
Meaning in Movement: Adaptation and the Xiqu Body in Intercultural Chinese Theatre

Zhuli xiaojie (adapted from Strindberg's Miss Julie) and Xin bi tian gao (from Ibsen's Hedda Gabler) are two works in a recent series of intercultural xiqu productions by playwrights William Huizhu Sun and Faye Chunfang Fei. In these works, the xiqu body serves as a medium for theatrical expression, where music, costume, movement, and props come together in a super-expressive acting technique that foregrounds qing (情), or sentiment. In these adaptations, the xiqu body compensates for what is necessarily cut from the text in the transformation from spoken drama to xiqu performance.
Restoring plant species diversity and community composition in a ponderosa pine-bunchgrass ecosystem

Monitoring of ecological restoration treatments often focuses on changes in community structure and function. We suggest that long-term changes in community composition also need to be explicitly considered when evaluating the success of restoration treatments. In 1992, we initiated an experiment in a ponderosa pine-bunchgrass ecosystem to evaluate responses to restoration treatments: (a) thinning the overstory vegetation (‘thinning’), (b) thinning plus forest floor manipulation with periodic prescribed burning (‘composite’), and (c) untreated ‘control.’ Treatments were further stratified by forest patch type: presettlement tree clumps (trees that established prior to the onset of fire exclusion in 1876), patches of retained postsettlement trees, patches where all postsettlement trees were removed, and remnant grass openings. Species richness did not differ among treatments for 10 years, but was highest in the composite treatment in 11th and 12th year after initial treatment. Community composition diverged among treatments 5 years after initial treatment, and compositional changes were greatest in the composite treatment. Species richness and composition differed among patch types prior to treatment. Remnant grass patches were the most diverse and presettlement patches were the least diverse. Following treatment, species richness in the postsettlement removed and retained patches, gradually approached levels found in remnant grass patches. Compositional differences among patch types changed a little by 2005. Species richness at the 2 m2 scale increased only where the overstory was thinned and the understory was burned. However, these changes may not be detectable for many years, and can vary temporally in response to events such as severe droughts. Nonnative species establishment may be reduced by scheduling longer burn intervals or by refraining from burning where fuel loads are not hazardous, though these options may hinder goals of increasing diversity. Restoring species diversity and community composition continues to be more difficult than restoring ecosystem structure and function.
Temporal and spatial variability of SSTs in the tropical Atlantic and Indian Oceans

The objective of this study is to describe spatial and temporal patterns of sea-surface temperature (SST) variability in the Atlantic and Indian Oceans. The analysis domain extends from 40°S to 25°N and 50°W to 80°E, hence the tropical and most of the South Atlantic and central and western Indian Oceans. The investigation, covering the years 1948 to 1979, utilizes the COADS marine data set. Empirical orthogonal functions and spectral analysis are used to analyze SST fields. A major finding of this investigation is that SSTs vary coherently throughout most of the analysis domain. The greatest coherence is evident from ∼10°N to 30°S in the Atlantic and from ∼20°N to 35°S in the western Indian Ocean. Spectral analysis of regional time series shows that throughout this region the time scale of 5–6 years is the dominant one in the fluctuations; this is also the case for the Southern Oscillation and for equatorial rainfall. SST variations are roughly in-phase within each ocean and the two oceans are roughly in-phase with each other, i.e., the lags which exist are much smaller than the dominant time scale of the fluctuations. The SST anomalies appear to propagate eastward from NE Brazil; the eastern Atlantic lags the western by two to six months and the Indian Ocean lags the western Atlantic by four to eight months.
Knee stability and graft function after anterior cruciate ligament reconstruction : a comparison of a lateral and an anatomical femoral tunnel placement

BackgroundLocations of femoral tunnels for anterior cruciate ligament replacement grafts remain a subject of debate.HypothesisA lateral femoral tunnel placed at the insertion of the posterolateral bundle of the anterior cruciate ligament can restore knee function comparably to anatomical femoral tunnel placement.Study DesignControlled laboratory study.MethodsTen cadaveric knees were subjected to the following external loading conditions: (1) a 134-N anterior tibial load and (2) combined rotatory loads of 10-N.m valgus and 5-N.m internal tibial torques. Data on resulting knee kinematics and in situ force of the intact anterior cruciate ligament and anterior cruciate ligament graft were collected using a robotic/universal force-moment sensor testing system for (1) intact, (2) anterior cruciate ligament-deficient, (3) anatomical double-bundle reconstructed, and (4) laterally placed single-bundle reconstructed knees.ResultsIn response to anterior tibial load, anterior tibial translation and in situ force in t...
Met-Cars: a unique class of molecular clusters

Abstract Currently there is extensive interest in systems of finite size as they often give rise to unique properties that differ from those of an extended solid or the individual molecular constituents of which they are comprised. Particularly interesting are systems whose composition can be selectively chosen, and ones whose individual characteristics may be retained, thus allowing them to serve as the building blocks for nanostructured/cluster-assembled materials. In 1992 we discovered a new class of molecular clusters termed metallocarbohedrenes, or Met-Cars for short, which involve bonding between early transition metals and carbon with a stoichiometry of M 8 C 12 . Calculations, as well as recent experimental findings, suggest that these species exhibit considerable free electron behavior which becomes manifested through observations of changing electronic energy levels with the nature of the metal. Indications that it is possible to produce Met-Cars with various endohedral atoms, as well as the finding that other metals and non-metal atoms may also be substituted in the cage lattice, suggest that these cluster materials are valuable in the context of unraveling the properties of condensed matter of finite size. This also opens an avenue for exploring the prospect that they may provide building blocks for new materials. Their discovery, formation, and ionization dynamics are reviewed herein. To cite this article: B.D. Leskiw, A.W. Castleman, C. R. Physique 3 (2002) 251–272.
Control of Nutrient Concentrations in the Seekonk-Providence River Region of Narragansett Bay, Rhode Island

Six synoptic samplings of nutrient concentrations of the water column and point-source inputs (rivers, sewage treatment plants) were conducted in the Seekonk-Providence River region of Narragansett Bay. Concentrations of nutrients (NH4 +, NO2 −+NO3 −, PO4 −3, dissolved silicon, particulate N, particulate C) were predicted using a conservative, two-layer box model in order to assess the relative influence of external inputs and internal processes on observed concentrations. Although most nutrients were clearly affected by processes internal to the system, external input and mixing explained most of the variability in and absolute magnitude of observed concentrations, especially for dissolved constituents. In the bay as a whole, two functionally distinct regions can now be identified: the Seekonk-Providence River, where dissolved nutrient concentrations are externally controlled and lower Narragansett Bay where internal processes regulate the behavior of nutrients. A preliminary nitrogen budget suggests that the Seekonk-Providence River exports some 95% of the nitrogen entering the system via point sources and bottom water from upper Narragansett Bay.
Long-Memory versus Option-Implied Volatility Predictions

Volatility is a critical parameter in virtually all option pricing models. But the closer we look at volatility, the harder it seems to be to model it correctly. The constant volatility assumption of early pricing models is clearly inadequate. GARCH family models make volatility a function of the asset price process, and stochastic volatility models bring in a second stochastic factor that affects volatility movements. These approaches make sense in theory, but empirically volatility shocks seem to be too persistent to be consistent with them. A further confounding factor is that implied volatilities extracted from option prices in the market are widely thought to give more accurate predictions of future realized volatility, but don9t obey any of these models exactly. In this article, Li examines a volatility model with “long memory,” meaning that it can be made to fit the slow-decay feature of market volatilities. He also introduces a much more extensive data series, with intraday observations every five minutes. Using such a dense price series, realized volatility becomes observable, and the vast number of data points allows precise estimation of model parameters. For exchange rates on the deutsche mark, the yen and the British pound, the ARFIMA (“Autoregressive Fractionally Integrated Moving Average”) model is shown to give a better fit to volatility behavior than the alternative model, and it beats implied volatility substantially in the standard tests of forecasting performance.
Developing a public key infrastructure for use in a teaching laboratory

Founded on the principle of easy information interchange the Internet is an inherently unsafe communication medium. Despite this inherent insecurity electronic mail continues to grow as a key communication technology. Individuals and businesses both large and small have come to rely on electronic mail. Fortunately technologies have evolved that address the lack of security in the base Internet electronic mail standards. Through the use of Public Key Infrastructure (PKI) technologies it is possible to build and deploy a secure electronic mail system that addresses the three key areas of security: authentication, authorization, and non-repudiation.This paper presents an implementation plan for deploying a PKI infrastructure for use in teaching these technologies to students in a laboratory environment. The techniques implemented and problems encountered are representative of those likely to be experienced by students in a real world implementation.
Prevalence of Vitamin D Deficiency in Chronic Liver Disease

Vitamin D deficiency has been associated with cholestatic liver disease such as primary biliary cirrhosis. Some studies have suggested that cirrhosis can predispose patients to development of osteoporosis because of altered calcium and vitamin D homeostasis. The aim of this study was to determine the prevalence of vitamin D deficiency in patients with chronic liver disease. One hundred and eighteen consecutive patients (43 with hepatitis C cirrhosis, 57 with hepatitis C but no cirrhosis, 18 with nonhepatitis C-related cirrhosis) attending the University of Tennessee Hepatology Clinic had their 25-hydroxyvitamin D level measured. Severity of vitamin D deficiency was graded as mild (20–32 ng/ml), moderate (7–19 ng/ml) or severe ( 32 ng/ml. Of patients, 109/118 (92.4%) had some degree of vitamin D deficiency. In the hepatitis C cirrhosis group, 16.3% (7/43) had mild, 48.8% (21/43) had moderate, and 30.2% (13/43) had severe vitamin D deficiency. In the hepatitis C noncirrhotic group, 22.8% (19/57) had mild, 52.6% (30/57) had moderate, and 14% (8/57) had severe vitamin D deficiency. In the nonhepatitis C-related cirrhosis group, 38.9% (7/18) had mild, 27.8% (5/18) had moderate, and 27.8% (5/18) had severe vitamin D deficiency. Severe vitamin D deficiency (<7 ng/ml) was more common among patients with cirrhosis compared with noncirrhotics (29.5% versus 14.1%, P value = 0.05). Female gender, African American race, and cirrhosis were independent predictors of severe vitamin D deficiency in chronic liver disease. Vitamin D deficiency is universal (92%) among patients with chronic liver disease, and at least one-third of them suffer from severe vitamin D deficiency. African American females are at highest risk of vitamin D deficiency.
Direct mass spectrometry analysis of untreated samples of ultralow amounts using extraction nano-electrospray

Direct mass spectrometry analysis of untreated samples of volumes as low as 0.2 μL was achieved using fast extraction and nanoESI (electrospray ionization) in a combined fashion. The analytes in dried samples on paper substrates were extracted by an organic solvent in a nanoESI tube and ionized with a high voltage applied for generating a spray. The ionization source produced stable signals for different atmospheric pressure interfaces of triple quadrupole instruments. Analysis times more than 20 minutes were available with 10 μL solvent consumed for the entire analysis process. The performance in qualitative and quantitative analyses was characterized with a wide variety of samples. Limits of detection as low as 0.1 ng mL−1 (corresponding to an absolute amount of 0.05 pg) were obtained for analysis of atrazine in river water, thiabendazole in orange homogenate, and methamphetamine in blood.