cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluation of alkaline pre-treatment of PLLA fibers for biomimetic hydroxyapatite coating

Abstract A poly( l -lactic acid) (PLLA) and hydroxyapatite (HA) composite was formed via a biomimetic coating process. Before treatment in a modified-simulated body fluid (m-SBF), the surfaces of the PLLA fibers were etched with alkaline reagents to make the polymer surface easier for apatite to nucleate and grow. Several elements of this etching procedure (including the etching reagent, concentration, and length of pre-treatment) were varied to determine the optimal combination for producing a predictable HA coating with the desired properties of consistent coating distribution and thickness. The alkaline etching reagents used in this study were sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), calcium hydroxide (Ca(OH) 2 ), and calcium hypochlorite (Ca(OCl) 2 ). The weight gained through m-SBF coating, changes in the mechanical properties of the PLLA, and HA coating morphology were observed to determine the effects of different pre-treatment strategies on the biomimetic coating process. It was confirmed that the most effective etching reagents are Ca(OH) 2 and Ca(OCl) 2 . It was also found that decreased etching reagent concentration leads to a decrease in HA coating and increased etching time increases HA deposition.
Geothermal energy, site specificity, and resource reserves

The site specific nature of geothermal energy places a great emphasis on land use and land use planning. A survey of the operating geothermal generating stations around the world reveals many different approaches to this relationship. In Italy, agricultural use of the land proceeds concurrently with geothermal development. In Mexico, on the other hand, no multipurpose use of the geothermal field is attempted whatsoever. Just north of the primary Mexican site, in the Imperial Valley of California, land use considerations have long delayed tapping one of the largest geothermal fields in the US. In Japan, concern over development in national parks has threatened the future of geothermal development. In the largest field, The Geysers of Northern California, conflicts between desires to develop the land both for recreation and also for electricity have slowed development and raised costs. If geothermal energy is to meet its generating potential “Resource Reserves” must be established to protect the resource.
Supporting food and exercise monitoring for overweight and obese children

This technical paper summarizes the methodology used to design an interactive food and exercise reporting program, called CFC GetFit. The team designed the site for the Chilidren's Fiteness Clinic (CFC) in Charlottesville, VA, and the site includes health education, patient progress, and the ability to receive short message service (SMS) text messages from users. It is hypothesized that children who use CFC GetFit will more accurately track their health habits and be more motivated to achieve goals, leading to a more successful and sustained weight loss. This paper describes the technical solution to the CFC's problem after analyzing all possible scenarios.
The SOLARC off-axis coronagraph

A 0.5m aperture off-axis coronagraphic telescope is described. Its fabrication, imaging, and scattered light performance is discussed in the context of simple model expectations.
Spatially explicit, nano-mechanical models of the muscle half-sarcomere: Implications for biomechanical tuning in atrophy and fatigue

Abstract Astronaut biomechanical performance depends on a wide variety of factors. Results from computational modelling suggest that muscle function—a key component of performance—could be modulated by compliance of the contractile filaments in muscle, especially when force is low such as transient Ca 2 + activation in a twitch, reduced activation in muscle fatigue encountered during EVA, or perhaps atrophy during prolonged space flight. We used Monte-Carlo models to investigate the hypotheses that myofilament compliance influences muscle function during a twitch, and also modulates the effects of cooperative interactions between contractile proteins on force generation. Peak twitch force and the kinetics of force decay were both decreased, while tension cost was increased, when myofilament compliance was increased relative to physiological values. Both the apparent Ca 2 + sensitivity and cooperativity of activation of steady-state isometric force were altered by myofilament compliance even when there were no explicit interactions included between binding sites. The effects of cooperative interactions between adjacent regulatory units were found to be greater than either the effect of myofilament compliance on apparent cooperativity of activation or that due to myosin cross-bridge-induced cooperativity. These results indicate that muscle function may be “tuned” at the molecular level, particularly under conditions of reduced Ca 2 + activation.
PRENATAL ETHANOL EXPOSURE STIMULATES NEUROGENESIS IN HYPOTHALAMIC AND LIMBIC PEPTIDE SYSTEMS: POSSIBLE MECHANISM FOR OFFSPRING ETHANOL OVERCONSUMPTION

Exposure to ethanol during the prenatal period contributes to increased alcohol consumption and preference in rodents and increased risk for alcoholism in humans. With studies in adult animals showing the orexigenic peptides, enkephalin (ENK), galanin (GAL) and orexin (OX), to stimulate ethanol consumption, the question addressed here is whether prenatal ethanol alters the development in utero of specific neurons that express these peptides. With reports describing suppressive effects of high doses of ethanol, we examined the offspring of dams gavaged from embryonic day 9 to parturition with a control solution or lower ethanol doses, 1 and 3g/kg/day, known to promote ethanol consumption in the offspring. To understand underlying mechanisms, measurements were taken in postnatal offspring of the expression of ENK in the hypothalamic paraventricular nucleus (PVN) and nucleus accumbens (NAc), GAL in the PVN, and OX in the perifornical lateral hypothalamus (PFLH) using real-time qPCR and in situ hybridization, and also of the cell proliferation marker, 5-bromo-2-deoxyuridine (BrdU), and its double-labeling with either neuronal nuclei (NeuN), a marker of mature neurons, or the peptides. On postnatal day 15 (P15), after two weeks without ethanol, the offspring showed increased expression of ENK in the PVN and NAc core but not shell, GAL in the PVN, and OX in the PFLH. In these same areas, prenatal ethanol compared to control increased the density at birth (P0) of neurons expressing these peptides and at P0 and P15 of neurons double-labeling BrdU and NeuN, indicating increased neurogenesis. These BrdU-positive neurons were found to express ENK, GAL and OX, indicating that prenatal ethanol promotes neurogenesis in these specific peptide systems. There were no changes in gliogenesis or apoptosis. This increase in neurogenesis and density of peptide-expressing neurons suggests the involvement of these hypothalamic and accumbal peptide systems in mediating the increased alcohol consumption observed in prenatal ethanol-exposed offspring.
Bacterially preexposed T cells impair bacterial elimination by non-Th1/Th2 cell mechanisms in a model of intra-abdominal infection

Abstract Background: Escherichia coli preexposure in mice results in impaired elimination of subsequent intra-abdominal infections by a CD4+ T cell–dependent process. Certain gram-negative infections have been shown to induce T-helper–(Th)2-type CD4+ T-cell differentiation, which correlates with impaired elimination of infection and death. We hypothesized that E coli preexposure impairs subsequent bacterial elimination as a consequence of Th2 differentiation and that interleukin-12 (IL-12) treatment could reverse this differentiation and minimize the effects of E coli preexposure. Methods: After preexposure to E coli or other species, BALB/c mice or interferon-γ (IFN-γ)–deficient mice, treated with or without IL-12, were given a standard intra-abdominal infection (E coli, Bacteroides fragilis, and adjuvant). Cohorts were killed for abscess quantification, in vitro T-cell proliferative responsiveness, and cytokine secretory profiles. Splenic lymphocytes preexposed in vivo to other types of bacteria were transferred to naive mice before intra-abdominal infection to determine whether preexposure, eliciting the lymphocyte-dependent response, was species specific. Results: E coli preexposure alone caused no Th1 or Th2 shift; increased the proliferative responses of T cells; and, in combination with IL-12 therapy, caused markedly decreased IL-2 and IL-4 responses and an increased IFN-γ response. IL-12 therapy did not change the response to intra-abdominal infection despite its ability to cause marked Th1 polarization. IFN--γ-deficient mice responded to E coli preexposure no differently than did wild-type mice. Transfer of lymphocytes preexposed to Pseudomonas aeruginosa, Klebsiella pneumoniae, and hemolytic E coli but not other types of nosocomial pathogens caused the development of more abscesses just as transfer of E coli preexposed lymphocytes had. Conclusions: CD4+ T cells responsive to E coli preexposure regulate subsequent intra-abdominal abscess formation by a mechanism not explained by the Th1/Th2 paradigm. Preexposure to hemolytic E coli and other Enterobacteriaceae alters responses to intra-abdominal infection. (Surgery 1998;124:418-28.)
The macrosociology of paid domestic labor

This article poses the question: What explains variation in the proportion of the labor force employed in paid domestic labor? In contrast to an older, modernization-theory-based literature that argued that paid domestic labor declines and ultimately disappears in the course of economic development, the authors note the occupation's recent expansion in southern California and the wide variations among rich, developed countries in the proportion of the female workforce employed in it. The authors argue that a crucial, neglected factor in explaining such geographic variations is the extent of economic inequality. This factor is overlooked not only in the modernization-theory-based literature but also in recent microsociological studies of paid domestic labor, which highlight the ways in which race, ethnicity, and citizenship status are implicated in interactions between employers of domestics and the workers themselves, while ignoring the enduring significance of class in the employer/domestic relationship....
Connecting Curriculum Materials and Teachers: Elementary Science Teachers’ Enactment of a Reform-Based Curricular Unit

The purpose of this study was to describe how teachers used and adapted a set of curriculum materials that included opportunities for students to engage in scientific practices. Two-fourth-grade teachers in the same school were observed and interviewed. Findings revealed that teachers enacted almost every type of scientific practice in the curriculum, but in ways that varied from the written curriculum materials. Teacher interviews revealed ways in which the teachers understood the rationale for various scientific practices and how to enact them. These findings have implications for curriculum developers, professional development designers, and teacher educators. The study identifies the need to support teachers’ understanding of scientific practices and why and how to enact them with their students.
A study of control flow and data dependency interface (abstract)

The results described in this paper is motivated by the desire to study the interface between the structure of control flow and data dependencies. The complexity of the control flow and the complexity of the data dependencies are necessarily intertwined. An increase in the complexity of the data dependencies will result from an increase in control flow complexity. A control flow alternation construct can result in an increase in the number of variable definitions that may be referenced. This increase in the number of referable definitions may extend far beyond the range of the alternation construct.In order to study the interface between control structure and data dependencies, a general abstraction describing the static structure of software is developed. The abstraction proposed in this paper is called Generalized Program Graph (GPG) and is a synthesis of the control flow graph and data dependency graph. Various sources of data dependencies in a program and live definitions of variables are discussed. An algorithm for constructing a GPG from a given source program in imperative languages is included. Some results of the analysis of the GPG structures and the interface between control and data dependency complexity are also presented. It appears that the GPG can directly be applied in the studies of software module interconnection complexity. Other important theoretical and practical application of the GPG are discussed. Because the GPG includes both the control flow and data dependency information in one abstraction, it can be used as an implementation model for the development of measurement and analysis tools for empirical research.
Digital Computation Makes AFCS More Reliable

In airline service the reliability of a system is more than the confirmed failures for the system; it is the total removal experience of the system. Thus, the reliability of a system lies not only in the piece part failure rates, but also in the capability to verify and isolate failures. The application of digital technology brings several significant reliability improvements to automatic flight control systems (AFCS) when compared to contemporary analog systems. These advantages are demonstrated by the experience of the digital air data computer (DADC) of the DC-10 and the digital AFCS of the JA-37 Viggen. Experience with this equipment is reviewed, and the results are interpreted in terms of projections for airline DAFCS reliability. The digital system built-in test implemented by a stored program and the central processor gives a system integrity and dispatch reliability unequaled by analog systems. This high-integrity self-test reduces removal rates by giving line personnel a trustworthy tool and more complete automatic test processes for verifying maintenance actions. Digital circuit technology is directly suitable to largescale integrated circuits (LSIC) which reduce piece part counts and improve LRU reliability. Digital circuits are less subject to drift and the attendant difficulty to detect failures. These factors, coupled with the inherent high-integrity self-test, provide the basis for a significant improvement in reliability by the use of a digital automatic flight control system.
Morphometric variation in Plio‐Pleistocene hominid distal humeri

The magnitude and meaning of morphological variation among Plio-Pleistocene hominid distal humeri have been recurrent points of disagreement among paleoanthropologists. Some researchers have found noteworthy differences among fossil humeri that they believe merit taxonomic separation, while others question the possiblity of accurately sorting these fossils into different species and/or functional groups. Size and shape differ- ences among fossil distal humeri are evaluated here to determine whether the magnitude and patterns of these differences can be observed within large- bodied, living hominoids. Specimens analyzed in this study have been assigned to various taxa (Aus- tralopithecus afarensis, A. africanus, A. anamensis, Paranthropus, and early Homo) and include AL 288-1m, AL 288-ls, AL 137-48a, AL 322-1, Gombork IB 7594, TM 1517, KNM-ER 739, KNM-ER 1504, KMN-KP 271 (Kanapoi), and Stw 431. Five extant hominoid populations are sampled to provide a standard by which to consider differences found between the fossils, including two modern human groups (Native American and African American), one group ofPan troglodytes, and two subspecies of Gorilla gorilla (G. g. beringei, G. g. gorilla). All possible painvise d values (average Euclidean distances) are calculated within each of the reference populations using an exact random- ization procedure. This is done using both raw linear measurements as well as scale-free shape data created as ratios of each measurement to the geomet- ric mean. Differences between each pair of fossil humeri are evaluated by comparing their d values to the distribution of d values found within each of the reference populations. Principal coordinate analysis and an unweighted pair group method with arithmetic averages (UPGMA) cluster analysis are utilized to further assess similarities and differences among the fossils. Fi- nally, canonical variates analysis and discriminant analysis are employed using all hominoid samples in order to control for correlations among variables and to identify those variables that discriminate among groups; possible affinities of individual fossils with specific extant species are also examined. The largest size differences, those between the small Hadar specimens and the two largest fossils (KNM-ER 739, IB 7594), can be accommodated easily within the ranges of variation of the two Gorilla samples, but are extreme relative to the other reference samples. The d values between most of the fossils based on shape data, with the notable exception of those associated
First South American record of Isthmomys pirrensis (Goldman, 1912) (Rodentia: Cricetidae: Neotominae)

Information is provided about the only known South American specimens of the cricetid rodent species Isthmomys pirrensis , which is otherwise known only from eastern Panama.
Heterogeneity of ganglia of the guinea pig myenteric plexus: An in vitro study of the origin of terminals within single ganglia using a covalently bound fluorescent retrograde tracer

Experiments were done to test the hypothesis that individual ganglia of the myenteric plexus of the guinea pig small intestine are heterogeneous with respect to the location of the neurons that provide terminals to them. The myenteric plexus, attached to the longitudinal layer of smooth muscle, was maintained in vitro. Individual ganglia were injected with a variety of potential retrograde tracers by pressure microejection from the tip (20-micron diameter) of a glass micropipette. The fluorescent dye 4-acetoamido, 4'-isothiocyanostilbene-2,2'-disulphonic acid (SITS) was found to be an effective tracer, labeling neuronal perikarya, evidently by retrograde transport. SITS has previously been shown not to cross plasma membranes, but to be covalently bound to the outer surface of that membrane, and to be taken up by nerve terminals to be retrogradely transported to label neuronal cell bodies. SITS fluorescence was found in about 12% of the neurons within the ganglion into which it was injected and also in approximately ten times more neurons in discretely located distant ganglia. No labeling of neurons was found when SITS was injected into the bath or into the smooth muscle below the myenteric plexus. Damage to neural connectives obstructed the labeling of neurons in ganglia distal to the injection site. Individual SITS-injected myenteric ganglia were found to vary greatly in the ratios of intraganglionic SITS-labeled neurons to the total number of neurons within the injected ganglion. The ratios of the number of intraganglionic SITS-labeled neurons to SITS-labeled neurons in distant ganglia projecting to the injected ganglion from elsewhere in the myenteric plexus also varied greatly. More strikingly, individual ganglia differed over a wide range with respect to whether the neurons in distant ganglia that provided them with terminals were situated in the oral, anal, or circumferential direction. Although the majority of projections were found to be from orally located ganglia, individual ganglia were observed that received predominantly or exclusively anal or oral projections. Others received mixtures of terminals from ganglia that were anal, oral, or circumferential. This anatomical heterogeneity in the location of afferent inputs to individual myenteric ganglia is probably reflected in a functional heterogeneity as well and will have to be taken into account in further studies of the physiology of the myenteric plexus. Individual ganglia of the plexus can no longer be taken as anatomically and functionally equivalent to one another.
Derivation of general equations describing tracer diffusion in any two-compartment tissue with application to ionic diffusion in cylindrical muscle bundles.

Abstract A set of generalized diffusion equations have been derived which describe radioactive tracer movement in any tissue that can be modeled as a distributed two-compartment system. These equations have been applied to ionic tracer movement in cylindrical muscle bundles, and the boundary conditions used correspond to experimental conditions during various ionic tracer diffusion experiments on cardiac papillary muscles. Specifically, solutions were obtained for extra- and intracellular tracer washout as well as for the extra- and intracellular steady-state tracer diffusion experiments of Weidmann (1966) . These solutions are presented in series form as well as in graphical form and are compared with the corresponding experimental data. A comparison of these solutions with those obtained using simple exponential kinetics is presented, and it is shown that there is a marked discrepancy between these two methods of analysis for bundles of any appreciable diameter.
Process Over Product: An Artist's Journey to [re]Definitions and Inquiry-Based Teaching

ABSTRACT An actor/teaching artist argues for a redefinition of process/product as a key step toward deeper learning through work in the arts.
Homeostasis of Brain Dynamics in Epilepsy: A Feedback Control Systems Perspective of Seizures

In an effort to understand basic functional mechanisms that can produce epileptic seizures, some key features are introduced in coupled lumped-parameter neural population models that produce “seizure”-like events and dynamics similar to the ones during the route of the epileptic brain towards seizures. In these models, modified from existing ones in the literature, internal feedback mechanisms are incorporated to maintain the normal low level of synchronous behavior in the presence of coupling variations. While the internal feedback is developed using basic feedback systems principles, it is also functionally equivalent to actual neurophysiological mechanisms such as homeostasis that act to maintain normal activity in neural systems that are subject to extrinsic and intrinsic perturbations. Here it is hypothesized that a plausible cause of seizures is a pathology in the internal feedback action; normal internal feedback quickly regulates an abnormally high coupling between the neural populations, whereas pathological internal feedback can lead to “seizure”-like high amplitude oscillations. Several external seizure-control paradigms, that act to achieve the operational objective of maintaining normal levels of synchronous behavior, are also developed and tested in this paper. In particular, closed-loop “modulating” control with predefined stimuli, and closed-loop feedback decoupling control are considered. Among these, feedback decoupling control is the consistently successful and robust seizure-control strategy. The proposed model and remedies are consistent with a variety of recent observations in the human and animal epileptic brain, and with theories from nonlinear systems, adaptive systems, optimization, and neurophysiology. The results from the analysis of these models have two key implications, namely, developing a basic theory for epilepsy and other brain disorders, and the development of a robust seizure-control device through electrical stimulation and/or drug intervention modalities.
The information lens, an intelligent system for information sharing in organizations

This paper describes an intelligent system to help people share and filter information communicated by computer-based messaging systems. The system exploits concepts from artificial intelligence such as frames, production rules, and inheritance networks, but it avoids the unsolved problems of natural language understanding by providing users with a rich set of semi-structured message templates. A consistent set of “direct manipulation” editors simplifies the use of the system by individuals, and an incremental enhancement path simplifies the adoption of the system by groups.One of the key problems that arises when any group of people cooperates to solve problems or make decisions is how to share information. Thus one of the central goals of designing good “organizational interfaces” (Malone, 1985) should be to help people share information in groups and organizations. In this paper, we will describe a prototype system, called the Information Lens, that focuses on one aspect of this problem: how to help people share the many diverse kinds of qualitative information that are communicated via electronic messaging systems.It is already a common experience in mature computer-based messaging communities for people to feel flooded with large quantities of electronic “junk mail” (Denning, 1982; Palme, 1984; Wilson, 1984; Hiltz & Turoff, 1985), and the widespread availability of inexpensive communication capability has the potential to overwhelm people with even more messages that are of little or no value to them. At the same time, it is also a common experience for people to be ignorant of facts that would facilitate their work and that are known elsewhere in their organization. The system we will describe helps solve both these problems: it helps people filter, sort, and prioritize messages that are already addressed to them, and it also helps them find useful messages they would not otherwise have received.The most common previous approach to structuring information sharing in electronic messaging environments is to let users implicitly specify their general areas of interest by associating themselves with centralized distribution lists or conference topics related to particular subjects (e.g., Hiltz & Turoff, 1978). Since these methods of disseminating information are often targeted for relatively large audiences, however, it is usually impossible for all the information distributed to be of interest to all recipients.The Information Lens system uses much more detailed representations of message contents and receivers' interests to provide more sophisticated filtering possibilities. One of the key ideas behind this system is that many of the unsolved problems of natural language understanding can be avoided by using semi-structured templates (or frames) for different types of messages. These templates are used by the senders of messages to facilitate composing messages in the first place. Then, the same templates are used by the receivers of messages to facilitate constructing a set of rules to be used for filtering and categorizing messages of different types.
Theoretical quasar emission-line ratios. VII - Energy-balance models for finite hydrogen slabs

The present energy balance calculations for finite, isobaric, hydrogen-slab quasar emission line clouds incorporate probabilistic radiative transfer (RT) in all lines and bound-free continua of a five-level continuum model hydrogen atom. Attention is given to the line ratios, line formation regions, level populations and model applicability results obtained. H lines and a variety of other considerations suggest the possibility of emission line cloud densities in excess of 10 to the 10th/cu cm. Lyman-beta/Lyman-alpha line ratios that are in agreement with observed values are obtained by the models. The observed Lyman/Balmer ratios can be achieved with clouds whose column depths are about 10 to the 22nd/sq cm.
Inhibition of apatite formation by phosphorylated metabolites and macromolecules

Apatite formation from synthetic extracellular fluids is rate-limited both at the initial amorphous precursor deposition step and at the amorphous-crystalline transformation reaction. Nucleotide diphosphates and triphosphates and low molecular weight metabolites containing two attached ester phosphate groups all inhibited amorphous-crystalline conversion at concentrations of 10−5 to 10−6 M. Both native and synthetic polynucleotides as well as the phosphoproteins from rat dentin or egg yolk also inhibited crystal formation from amorphous calcium phosphate. In all cases, substantial amounts of inhibitor molecules were incorporated into the stabilized amorphous precipitates. Treatment of isolated, inhibitor-stabilized amorphous precipitates with hydrolytic enzymes such as alkaline phosphatase or papain reversed the inhibitory effect and permitted crystallization to proceed normally.
Cloning of Streptomyces griseus and Streptomyces lividans genes for glycerol dissimilation.

Abstract Streptomyces lividans gyl DNA (for glycerol utilisation) was cloned by complementation of a Streptomyces coelicolorgyl mutant. Restriction mapping showed that the cloned DNA was highly homologous (perhaps 99%) to S. coelicolor gyl DNA. Using phage-mediated mutational cloning, an internal fragment of the S. coelicolor gyl operon was used to generate a gyl mutant of S. lividans, which subsequently served as recipient in the cloning of gyl DNA from S. griseus. A 7.5-kb SstI-generated fragment of S. griseus DNA was obtained which, as judged by analysis of restriction sites, was only perhaps 87 % homologous with the S. coelicolor gyl operon. The cloned S. griseus DNA appears to contain intact gylA and gylB genes and probably also an upstream gene related to the putative gyl regulatory ‘0.9-kb’ gene of S. coelicolor. Cloning of the fragment on a high-copy-number vector in S. lividans did not lead to high levels of the enzymes encoded by gylA and gylB. The S. griseus gylA and gylB genes were not detectably expressed in Escherichia coli glp mutants.
Besicovitch Covering Lemma, Hadamard manifolds, and zero entropy

It is proved that if the Besicovitch Covering Lemma is true on either a Hadamard manifold or a simply connected surface without focal points that covers a compact quotient, then the manifold is the Euclidean space. As a corollary, the vanishing of the topological entropy of a compact manifold of nonpositive curvature or of a compact surface without focal points is equivalent to the validity of the Besicovitch Covering Lemma on the universal covering space of the manifold.
Thermal compensation of respiratory enzymes in tissues of the goldfish (Carassius auratus L.)

Abstract 1. 1. Cytochrome oxidase activity, determined over the range 10–40°C was higher at all assay temperatures in brain, gill and muscle homogenates of 10°C-acclimated goldfish than 30°C-acclimated fish, but was only higher in liver homogenates when assayed at 30 and 40°C. 2. 2. Thermal compensation of gill cytochrome oxidase did not appear to involve a significant increase in the mitochondrial content of the cells. 3. 3. Cytochrome oxidase, succinate-cytochrome-c reductase and NADH-cytochrome-c reductase activities were all higher in gill mitochondrial preparations from cold-acclimated fish. 4. 4. The concentration of cytochrome-c1 was reduced in gill mitochondria of cold- compared to warm-acclimated goldfish. However, the concentrations of cytochromes-aa3, -b and -c were similar in these two groups. 5. 5. It nis suggestes that mitochondrial electron transport systems compensate to the degree necessary to meet changing ATP demands of goldfish exposed to new environmental temperatures.
Tillage and Seeding Rate Effects on Wheat Cultivars

Tillage is declining in wheat production systems in the Great Plains. Our objective was to determine if a tillage × cultivar interaction occurred for grain yield, protein concentration, kernel weight, and test weight for hard red spring wheat (Triticum aestivum L. emend. Thell.) in a wheat-fallow monoculture. We also wanted to know if seeding rate × cultivar and tillage × seeding rate × cultivar interactions occurred for these grain traits. The cultivars AC Minto, Amidon, Bergen, Grandin, and Norm were seeded at 123, 247, and 371 live kernels m -2 in conventional-till (CONT), reduced-till (RT), and notill (NT) systems in a randomized complete block with a split split-plot arrangement in southwestern North Dakota during 1995-1998. Tillage X cultivar, seeding rate × cultivar, and tillage X seeding rate × cultivar interactions did not occur for any grain trait (P > 0.05). Grain yield, protein concentration, kernel weight, and test weight were unaffected by tillage system. A positive quadratic response in grain yield occurred as the seeding rate was increased. Grain test weight increased from 577 to 586 g m -3 as the seeding rate increased from 123 to 371 kernels m -2 , but grain protein concentration and kernel weight were unaffected. Grain yield ranged from 2473 to 3063 kg ha -1 , crude protein from 141 to 154 g kg -1 , kernel weight from 30 to 32 g (1000 kernels) -1 , and test weight from 572 to 590 g m -3 among the five cultivars. Results of this study suggest that cultivar recommendations under CONT can be extended to RT and NT systems in a wheat-fallow monoculture.
Joint Injury and Post-Traumatic Arthritis:

Our studies in this murine model of PTA suggest that the response of the joint to injury is an organ level, or possibly even systemic response, and not simply a response of the cartilage in isolation [11]. This knowledge may be helpful in understanding how to translate findings from in vivo investigations into future therapies. There is a great need to understand the human response to injury. At this time it is not clear whether the response to an articular fracture is similar in character to a response seen in other forms of osteoarthritis. The primary advantage of the intra-articular fracture model is a defined time point of disease onset. Focus on the articular fracture response may give clues to mechanisms that may be in play in other types of arthritis.
Amenity driven price effects and conservation reserve site selection: A dynamic linear integer programming approach

Most conservation reserve design models presented in the literature are static and ignore the dynamic economic aspects of site selection. Typically conservation programs operate under time-related (e.g. annual) budgets and purchase land over time in a sequential manner. The uncertainty of land development has been incorporated in a few dynamic reserve selection formulations using stochastic dynamic programming. However, the existing formulations do not explicitly deal with inter-temporal price and location linkages. We address this issue here and present a two-period linear integer programming model for conservation reserve design that incorporates amenity driven price feedback effects inherent in the reserve development problem. In addition, the model includes spatial and ecological criteria. We then use this model to answer the question “How suboptimal is ignoring amenity driven price effects in reserve design models?” We apply the model to artificially generated data sets and compare the results with the results of an iterated static model that considers only one period at a time. We find that the dynamic model with price feedback effects selects sites at a lower per-site cost. The policy implication of this finding is that conservation programs should avoid purchasing land in the same neighborhood over multiple time periods.
View Consistency in Architectures for Cyber-Physical Systems

Current methods for modeling, analysis, and design of cyber-physical systems lack a unifying framework due to the complexity and heterogeneity of the constituent elements and their interactions. Our approach is to define relationships between system models at the architectural level, which captures the structural interdependencies and some semantic interdependencies between representations without attempting to comprehend all of the details of any particular modeling formalism. This paper addresses the issue of defining and evaluating consistency between architectural views imposed by various heterogeneous models and a base architecture (BA) for the complete system. This notion of structural consistency ensures that the model elements adhere to the cyber and physical types and the connections between components present in the BA, which serves as the unifying framework for model-based development. Consistency checking between a model and the underlying system architecture is formulated as a typed graph matching problem between the connectivity graphs of the corresponding architectural view and the system's BA. The usefulness of the approach to check system modeling assumptions is illustrated in the context of two heterogeneous views of a quad rotor air vehicle.
Mortality among recent purchasers of handguns.

Background There continues to be considerable controversy over whether ownership of a handgun increases or decreases the risk of violent death. Methods We conducted a population-based cohort study to compare mortality among 238,292 persons who purchased a handgun in California in 1991 with that in the general adult population of the state. The observation period began with the date of handgun purchase (15 days after the purchase application) and ended on December 31, 1996. The standardized mortality ratio (the ratio of the number of deaths observed among handgun purchasers to the number expected on the basis of age- and sex-specific rates among adults in California) was the principal outcome measure. Results In the first year after the purchase of a handgun, suicide was the leading cause of death among handgun purchasers, accounting for 24.5 percent of all deaths and 51.9 percent of deaths among women 21 to 44 years old. The increased risk of suicide by any method among handgun purchasers (standardized mo...
Semikinetic and generalized transport models of the polar and solar winds

In order to gain a better understanding of the relative merits of the transport and kinetic approaches to modeling thermal space plasmas, a comparison is presented of a transport (bi-Maxwellian-based 16-moment equations) and a semikinetic description of supersonic flow in the solar wind and also of both supersonic and subsonic flows in the polar wind for 'steady state' conditions. The study shows: remarkable agreement between the two models for supersonic collisionless flows, even for the higher-order moments; the inadequacy of the semikinetic approach for modeling subsonic flows; and the superiority of the 16-moment transport over the semikinetic approach for modeling the solar wind. Further evidence that the bi-Maxwellian-based transport equations are a useful tool for studying 'thermal' space plasmas that develop non-Maxwellian features is provided.
Hybrid sketching: a new middle ground between 2- and 3-d

This thesis investigates the geometric representation of ideas during the early stages of design. When a designer's ideas are still in gestation, the exploration of form is more important than its precise specification. Digital modelers facilitate such exploration, but only for forms built with discrete collections of high-level geometric primitives; we introduce techniques that operate on designers' medium of choice, 2-D sketches. Designers' explorations also shift between 2-D and 3-D, yet 3-D form must also be specified with these high-level primitives, requiring an entirely different mindset from 2-D sketching. We introduce a new approach to transform existing 2-D sketches directly into a new kind of sketch-like 3-D model. Finally, we present a novel sketching technique that removes the distinction between 2-D and 3-D altogether. This thesis makes five contributions: point-dragging and curve-drawing techniques for editing sketches; two techniques to help designers bring 2-D sketches to 3-D; and a sketching interface that dissolves the boundaries between 2-D and 3-D representation. The first two contributions of this thesis introduce smooth exploration techniques that work on sketched form composed of strokes, in 2-D or 3-D. First, we present a technique, inspired by classical painting practices, whereby the designer can explore a range of curves with a single stroke. As the user draws near an existing curve, our technique automatically and interactively replaces sections of the old curve with the new one. Second, we present a method to enable smooth exploration of sketched form by point-dragging. The user constructs a high-level “proxy” description that can be used, somewhat like a skeleton, to deform a sketch independent of the internal stroke description. Next, we leverage the proxy deformation capability to help the designer move directly from existing 2-D sketches to 3-D models. Our reconstruction techniques generate a novel kind of 3-D model which maintains the appearance and stroke structure of the original 2-D sketch. One technique transforms a single sketch with help from annotations by the designer; the other combines two sketches. Since these interfaces are user-guided, they can operate on ambiguous sketches, relying on the designer to choose an interpretation. Finally, we present an interface to build an even sparser, more suggestive, type of 3-D model, either from existing sketches or from scratch. “Camera planes” provide a complex 3-D scaffolding on which to hang sketches, which can still be drawn as rapidly and freely as before. A sparse set of 2-D sketches placed on planes provides a novel visualization of 3-D form, with enough information present to suggest 3-D shape, but enough missing that the designer can ‘read into’ the form, seeing multiple possibilities. This unspecified information—this empty space—can spur the designer on to new ideas. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
The purification and properties of yeast isocitric lyase.

SUMMARY 1. Isocitric lyase, which catalyzes the reversible cleavage of L,-isocitrate to glyoxylate and succinate, has been identified in a number of molds, and has been purified 70-fold from yeast autolysates. 2. The purified yeast enzyme acts only on n.-isocitric acid and requires magnesium and cysteine for activity. Manganous ions are 40 per cent as active as magnesium, and reduced glu- tathione can replace cysteine. The enzyme is inhibited by low concentrations of copper, cadmium, zinc, p-chloromercuriben- zoate, and o-iodosobenzoate. 3. The biological function of isocitric lyase is discussed, and a possible mechanism for the cleavage of isocitrate involving chelation with magnesium is presented. Acknowledgments-The author appreciates the able assistance of Mr. Joseph Gonzalez in purifying the enzyme and in studying its characteristics, and the courtesy of Dr. Alfred Ritchie in carrying out electrophoretic analyses. He is also indebted to Professor E. B. Chain and Professor Domenico Marotta of the Istituto Superiore di Sanita, Rome, Italy, for encouragement during the initiation of this work. REFERENCES
Transvenous embolization of a dural arteriovenous fistula of the laterocavernous sinus through the pterygoid plexus

We present a novel access for transvenous embolization of a dural arteriovenous fistula of the laterocavernous sinus through the external jugular vein and the pterygoid plexus. The anatomy of the laterocavernous sinus is reviewed, and its clinical implications discussed in light of the case of a patient whose management was modified after identifying this anatomical variation.
Gain and cardiac E-C coupling: revisited and revised.

See related article, pages 590–597 A phenomenon that has fostered much experimental investigation and theoretical speculation is “gain” in cardiac E-C coupling. So-called “macroscopic” or “whole-cell” gain may be defined as the ratio of the total flux through the SR Ca2+ release channels (RyR) to that through the L-type Ca2+ channels (LCC). Experimentally, gain was found early on to be relatively high, and this observation, together with the seemingly incompatible fact that Ca2+-induced Ca2+ release (CICR) is normally tightly controlled in cardiac muscle, led to the development of the modern understanding of cardiac E-C coupling, the “local control” theory. Gain reflects not only the operation of the fundamental processes that underlie normal E-C coupling, but also those involved in important pathological conditions of the heart, particularly those produced by uncontrolled SR Ca2+ release, such as triggered arrhythmias.1 In the heart, it can be said that “not all Ca2+ currents ( I Ca) are created equal”; I Ca at negative potentials is much more efficacious in triggering SR Ca2+ release than is equivalent (peak) I Ca at positive potentials. Therefore, gain decreases as activating voltage is made more positive. The conventional and widely accepted explanation of this phenomenon is based on the voltage-dependence of the single-channel (unitary) Ca2+ current ( i Ca), and was stated succinctly by Stern and his colleagues,2 “gain decreases with voltage because the efficacy of the L-type current to trigger release from the RyR depends on the unitary current of the L-type channel, which decreases as the calcium reversal potential is approached”. Indeed this is a cornerstone of the local control theory of cardiac E-C coupling. However, early on it had been recognized3 (also by Stern) that “the discrepancy between these two curves (Ca2+ current …
Finger Movement Classification for an Electrocorticographic BCI

We study the problem of distinguishing between individual finger movements of one hand using electrocorticographic (ECOG) signals. In previous work, we have shown that ECOG signals have high predictive accuracy and spatial resolution for classifying hand versus tongue movements. In this paper, we significantly extend this paradigm by studying the first 5-class classification problem for ECOG, and show that an average 5-class accuracy of 23% across 6 subjects is possible using as little as 10min of training data. In addition to opening up possibilities for higher-bandwidth brain-computer interfaces, the use of finger movements for control may yield a more intuitive mapping from ECOG signals to control of a prosthetic. Although this study uses real movements, our results provide the foundation for understanding ECOG signal changes during finger movement.
RNA That Gets RAN in Neurodegeneration

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are devastating neuromuscular and cognitive diseases, respectively, with substantial clinical, genetic, and neuropathological overlap ( 1 ). Mutation in the gene C9orf72 is the most common genetic defect underlying these two diseases ( 2 , 3 ). On page 1335 of this issue, Mori et al. ( 4 ) report that a "repeat expansion" mutation in C9orf72 causes an unusual defect in RNA metabolism that may contribute to ALS, FTD, and other neurological disorders.
Reaction of ferric Caldariomyces fumago chloroperoxidase with meta-chloroperoxybenzoic acid: sequential formation of compound I, compound II and regeneration of the ferric state using one reactant

The mechanism of the reaction between ferric Caldariomyces fumago chloroperoxidase (CCPO) and meta-chloroperoxybenzoic acid (mCPBA) has been examined. It has previously been established that an Fe(IV)-oxo porphyrin radical species known as Compound I (Cpd I) is formed by two-electron oxidation of the native ferric enzyme by a variety of oxidants including organic peracids and hydroperoxides. Cpd I can return to the ferric state either by direct oxygen insertion into an organic substrate (e.g. a P450 oxygenase-like reaction), or by two consecutive one-electron additions, the first resulting in an intermediate Fe(IV)-oxo species known as Compound II (Cpd II). There has been much debate over the role of Cpd II and the details of its structure. In the present study, both CCPO Fe(IV)-oxo intermediates are formed, but unlike most CCPO reactions, Cpd I and Cpd II are formed using the same reactant, mCPBA. Thus, the peracid is used as an oxo donor to produce Cpd I and then as a reductant to reduce Cpd I to Cpd II, and finally, Cpd II to the ferric state. The observation of saturation kinetics with respect to mCPBA concentration for each step is consistent with the formation of CCPO-mCPBA complexes in each phase of the reaction. The original reaction mechanism for ferric CCPO with mCPBA was hypothesized to involve a scrambling mechanism with a unique Fe-OOO-C(O)R intermediate formed with no observed Cpd II intermediate. The data reported herein clearly demonstrate the formation of Cpd II in returning the oxidized enzyme back to its native ferric state.