cssi/SciSciGPT-SciSciNet huggingface dataset:
Tensile and fatigue properties of a 25 vol% SiC particulate reinforced 6090 Al composite at 300 °C

Discontinuously-reinforced metal matrix composites (MMCs) are attractive for many structural applications because the materials exhibit unusual combinations of structural, physical, and thermal properties. In this paper, the authors present the tensile and fatigue properties of a 25 vol% SiC particulate-reinforced 6090 Al composite at 300 C. Several conclusions can be drawn from this study: (1) The fatigue strength, [sigma][sub e], of 25 vol% SiC[sub p]-reinforced 6090 Al composite decreases from 195 MPa at room temperature to 63 MPa at 300 C. However, the endurance ratio, [sigma][sub e]/UTS, increases from 0.37 at room temperature to 0.50 at 300 C. (2) Fatigue cracks initiate primarily within the matrix or at random sites less than 1 [mu]m in size. However, they occasionally initiate from sites with SiC agglomeration. (3) At 300 C, test samples exhibit large ductility during high-cycle fatigue; deformation strain increases with increasing cycles-to-failure. (4) The macroscopic fatigue fracture mode at 300 C changes from slip band formation at low cycles to intergranular fracture at high cycles. (5) Crack growth occurs through plastic deformation of the matrix without particle fracture or particle/matrix decohesion. (6) The major change in fatigue response of 6090/SiC/25p (T6) with change in temperature from 20 C tomore » 3,000 C appears to be the mechanism of fatigue crack growth. Fatigue crack initiation mechanisms remain largely unchanged.« less
A framework for incorporating dynamic strategies in earth-moving simulations

Earthwork projects involve moving specific amounts of earth from a discrete set of source locations to a discrete set of destinations. Constructors use different methods and equipment to move earth depending primarily on haul distance and equipment availability. Successful earthwork projects involve successively refined cycles of constructio n plan preparation and evaluation. The construction plan includes the determination and sequencing of tasks as well as the strategies for allocation of resources among them. The ideal method of evaluating the plan is to simulate models that incorporate the details of the plan and that rely on fundamental engineering analysis and estimated performance, cost and availability of resources. Current research at Virginia Tech focuses on the development of technology that accurately captures, models, and evaluates the strategic plan envisioned by the planner. This paper presents a framework for the integration of project-level and process-level simulations with the dynamic strategies that form the core of the plan. Obvious benefits that result from implementin g this framework include more accurate cost estimation and improved construction performance. The paper illustrates essential concepts with a project involving the extension of an airport runway.
Characteristics of the Armstrong-Frederick type plasticity models

Abstract The ability to model inelastic deformation is of practical interest in many design applications, with the current emphasis on lighter weight structures and components. Incremental plasticity algorithms are often employed to model the plastic deformation. Some of the questions raised with both theoretical and engineering ramifications include, how are the material constants determined and how sensitive is the model to the choice of the constants? The characteristics of a category of Armstrong-Frederick hardening rules are examined, invoking both theoretical and experimental considerations. Depending on the complexity of the model, phenomena such as ratchetting rate decay can be modeled with these algorithms. The model is shown to be insensitive to the yield stress chosen. Numerical extrapolation of the cyclic stress-strain curve is shown to enhance modeling without any penalty. The additional material constants employed to model ratchetting have a minimal influence on either proportional or nonproportional balanced loadings, hence these terms can be considered to be decoupled. Behavior of the predicted deformation becomes asymptotic for all loadings investigated with approximately ten terms in the backstress expansion. All these factors indicate the engineering potential of the Armstrong-Frederick type models, which include the Chaboche and Ohno-Wang enhancements. Furthermore, the basic structure of the model is amenable to incorporation of other material behaviors such as non-Masing, cyclic hardening or softening, and nonproportional hardening.
Gauge-invariant cosmological perturbation theory with seeds.

Gauge-invariant cosmological perturbation theory is extended to handle perturbations induced by seeds. A calculation of the Sachs-Wolfe effect is presented. A second-order differential equation for the growth of density perturbations is derived and the perturbation of Liouville's equation for collisionless particles is also given. The results are illustrated by a simple analytic example of a single texture knot, where we calculate the induced perturbations of the energy of microwave photons, of baryonic matter, and of collisionless particles.
Fractal growth in hydrodynamic dispersion through random porous media

Results from the numerical simulation of hydrodynamic dispersion in model random porous media are presented. The morphology of a spreading dye (or tracer), as a function of Peclet number, is studied. In the limit of infinite Peclet number, the dye pattern formed is fractal with fractal dimension close to that observed in diffusion-limited aggregation (DLA) in both two and three dimensions. Also, as in DLA, multifractal behavior is exhibited. At moderately high Peclet numbers the pattern formed by the dispersing dye in a two-dimensional porous medium is fractal over the width of the front as observed in experiment. In the low Peclet number regime contours of equal concentration are self-affine with an anomalously large roughness exponent. By comparison, we show that the pattern formed by a dilute ion concentration driven by an electric field, rather than a flow field, is also self-affine but with the usual roughness exponent of 0.5.
Providing the requisite knowledge via software documentation

Software documentation should be useful to the programmer trying to understand a program. The key in that sentence was the word should: by and large documentation has a very bad reputation. We have been working on trying to improve documentation, in order that it may realize its potential. In this case study, we examine a programmer's use of documentation constructed along some specific guidelines. These guidelines, developed from our previous studies of documentation, are intended to help programmers draw causal connections between non-contiguous portions of programming plans in the program. This documentation appears to be helpful to a particular class of programmers, i.e., those who come to a program without the requisite background knowledge.
The Larval Development of the Tropical Land Hermit Coenobita Clypeatus (Herbst) in the Laboratory 1)

[Le pagure terrestre Coenobita clypeatus a ete eleve en laboratoire a partir de l'oeuf ; quatre, cinq ou six stades zoe ont ete obtenus, suivis de la metamorphose en glaucothoe. L'auteur decrit et illustre la morphologie externe, appendices inclus, pour cinq stades zoe et pour la glaucothoe. Le nombre des stades est variable suivant les individus dans les conditions de laboratoire et les variations dans la setation des appendices s'accroissent progressivement au cours du developpement. Dans la famille des Coenobitidae les premieres zoes de Birgur latro et de deux especes de Coenobita au moins presentent un caractere commun: une epine postero-medio-dorsale et une paire d'epines laterales sur le cinquieme somite abdominal. Les premieres zoes des deux especes de Coenobita ont en commun la presence d'epines medio-postero-dorsales sur les somites abdominaux deux, trois et quatre. Les stades glaucothoe de Coenobita clypeatus et de C. rugosus montrent les caracteres distinctifs suivants : un flagelle antennaire de sept segments avec une soie distale extremement longue sur le segment terminal, et un telson legerement plus large que long, portant sur le bord posterieur neuf longues soies plumeuses et trois paires de soies plus courtes. Les comparaisons detaillees des stades larvaires de C. clypeatus avec ceux d'autres especes de la meme famille ou d'autres familles necessitent des etudes detaillees complementaires., Le pagure terrestre Coenobita clypeatus a ete eleve en laboratoire a partir de l'oeuf ; quatre, cinq ou six stades zoe ont ete obtenus, suivis de la metamorphose en glaucothoe. L'auteur decrit et illustre la morphologie externe, appendices inclus, pour cinq stades zoe et pour la glaucothoe. Le nombre des stades est variable suivant les individus dans les conditions de laboratoire et les variations dans la setation des appendices s'accroissent progressivement au cours du developpement. Dans la famille des Coenobitidae les premieres zoes de Birgur latro et de deux especes de Coenobita au moins presentent un caractere commun: une epine postero-medio-dorsale et une paire d'epines laterales sur le cinquieme somite abdominal. Les premieres zoes des deux especes de Coenobita ont en commun la presence d'epines medio-postero-dorsales sur les somites abdominaux deux, trois et quatre. Les stades glaucothoe de Coenobita clypeatus et de C. rugosus montrent les caracteres distinctifs suivants : un flagelle antennaire de sept segments avec une soie distale extremement longue sur le segment terminal, et un telson legerement plus large que long, portant sur le bord posterieur neuf longues soies plumeuses et trois paires de soies plus courtes. Les comparaisons detaillees des stades larvaires de C. clypeatus avec ceux d'autres especes de la meme famille ou d'autres familles necessitent des etudes detaillees complementaires.]
Stochastic excitation and delayed oscillation of a micro-oscillator

Stochastic processes in the form of the classical Brownian motion or internal phonon fluctuations may be studied by the use of a microcantilever. We present certain dynamic aspects of the behavior of the noise and the delayed fluctuations exhibited by a microcantilever. In particular, we present an analytic solution describing the transient response of the oscillator and discuss how self-excitation may determine the presence of small delays and, conversely, how delay-induced excitation may provide sensory information. As an application of the analysis, we present dynamic measurement of surface displacement with a preliminary sensitivity of 2 Hz/m in the chosen frequency window, which may effectively be extended to the nanometer regime.
A fast two-dimensional median filtering algorithm

We present a fast algorithm for two-dimensional median filtering. It is based on storing and updating the gray level histogram of the picture elements in the window. The algorithm is much faster than conventional sorting methods. For a window size of m × n, the computer time required is 0(n).
Salivary gland function in phenol oxidase production in Drosophila melanogaster

Abstract Of the five protein components that have been shown to be involved in phenol oxidase production in extracts of Drosophila melanogaster, component S is rate limiting in the activation process. By means of sectioning of whole animals and dissection of specific tissues it has been established that S is initially localized in the larval salivary gland where it is apparently produced and secreted. The S component appears to be released in the haemolymph in late third-instar larvae but it is not present in an active form in early prepupae. A procedure is given for the purification of and the measurement of the activity of the S component.
Vertical fiscal imbalances and fiscal performance in advanced economies

The paper examines empirically, using a measure of “vertical fiscal imbalances” (VFI), the relationship between overall fiscal performance and the financing structure of subnational governments. It presents stylized facts regarding the size, evolution, and components of measured VFI using data from 28 OECD countries. On average, the general government fiscal balance is found to improve by 1 percent of GDP for each 10 percentage point reduction in VFI.
Computed tomography screening for lung cancer

The development of CT technology reopened the lung cancer screening debate. Computed tomography screening for lung cancer certainly meets all the criteria required for an appropriate screening test. First and perhaps most importantly, the disease for which the screening is being performed should have a significant prevalence in the population being studied and be a significant health risk for those afflicted with it. Lung cancer is the leading cause of cancer death in both men and women, and one of the most lethal of all cancers.
Administering agricultural exchanges

Abstract Exchanges of agricultural scientists are an effective means of advancing agricultural science and technology for both developed and developing countries. Three key factors need to be addressed during the planning and administration of agricultural exchanges, as they often determine the final success or failure of an agricultural exchange. The three factors essential to a successful exchange program are: (1) clarity and mutual understanding of goals and objectives; (2) understanding in dealing with the unique characteristics of the country involved, its people, and its institutions; and (3) monitoring and feedback from participants and other interested parties.
Diadenosine Tetraphosphate (Ap4A) and Triphosphate (Ap3A) Signaling of Human Sperm Motility

The ubiquitous dinucleotide poly phosphate, diadenosine tetraphosphate (Ap4A), has been shown to be a signal molecule for DNA replication in mammalian cells. In this study, Ap4A and a related compound, diadenosine triphosphate (Ap3A), were tested for possible signaling functions in human spermatozoa. A computerized automated semen analyzer was used to detect changes in spermatozoa motil-ity parameters. Cryopreserved-thawed donor spermatozoa were washed and incubated in 0.1 mM Ap4A, 0.1 mM Ap3A, or control medium. The data indicated that both Ap4A and Ap3A decreased the percentage of motile spermatozoa after 4 or more hours of incubation in vitro. The two dinucleotide polyphosphates caused an increase in the amplitude of lateral spermatozoa head displacement parameter only at the start of incubation. The other spermatozoa kinematic parameters were unaffected. No opposing ying-yang dual actions of Ap4A to Ap3A were seen. From the results, Ap4A and Ap3A were observed to be potential inhibitory signals of spe...
An extremal region for harmonic measure

We begin with an extremal length problem which can be considered as a generalization of a problem of J. Hersch. To this problem there is associated an extremal region analogous to the extremal regions of Grotzsch, Teichmuller, and Mori. When the extremal length invariant is related to the harmonic measure invariant we obtain an inequality for harmonic measure which was first found by A. Ostrowski using a different definition of harmonic measure. We also show that our result implies Ostrowski's result.
Stylus-laser surface calibration system

Abstract A stylus-laser surface calibration system was developed to calibrate the NIST sinusoidal roughness Standard Reference Materials (SRM) 2071-2075. Step height standards are used to calibrate the stylus instrument in the vertical direction, and a laser interferometer is mounted on the traversing unit of the stylus instrument to calibrate the instrument in the horizontal direction. The calibration uncertainty (±2δ) for SRM 2075 is ±1.2% for roughness calibrations (( R a = 1 μ m), and ±0.06% for spatial wavelength calibrations ( S m = 800 μ m).
Infrared response of chemisorbed CO to femtosecond metal substrate heating

Time resolved IR spectroscopy is used to monitor the stretch mode of CO on Cu(111) following femtosecond visible excitation. A time dependent shift in the stretch mode complex frequency is observed and is attributed to low frequency adsorbate-like modes becoming excited via coupling to substrate electrons and phonons. At low levels of excitation it is found that the frustrated translation is coupling to the bulk electron reservoir with a rate (gamma) eequals167(24) GHz, and to the bulk phonon reservoir with a rate (gamma) Lequals145(56) GHz. At higher excitation levels deviations from the model are observed.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Deformation Quantization of Heisenberg Manifolds

ForM a smooth manifold equipped with a Poisson bracket, we formulate aC*-algebra framework for deformation quantization, including the possibility of invariance under a Lie group of diffeomorphisms preserving the Poisson bracket. We then show that the much-studied non-commutative tori give examples of such deformation quantizations, invariant under the usual action of ordinary tori. Going beyond this, the main results of the paper provide a construction of invariant deformation quantizations for those Poisson brackets on Heisenberg manifolds which are invariant under the action of the Heisenberg Lie group, and for various generalizations suggested by this class of examples. Interesting examples are obtained of simpleC*-algebras on which the Heisenberg group acts ergodically.
From Oppression to Hope: Freire's Journey toward Utopia

Despite those who want to relegate him exclusively to the ranks of adult educators, Freire's conclusions are pertinent to learning throughout one's life. Because his philosophy of education is eclectic and his interests are universal, the influence of his thought affects progressive educators from preschool to the Gray Panthers. In particular, those who believe in the implications of hands-on, experiential learning are fascinated with Freire's insight into the phenomenon of oppressed consciousness and the need for adequate pedagogies to respectfully address marginated populations. This article tries to answer the question "Why would people in the United States study educational philosophy and pedagogy originating in Brazil?" by pointing out the relevance and affinity of Freire's pedagogy of the oppressed to U.S. pragmatic and existential thinking about schools. It also intends to provide new readers of Freire an overview of his major works, along with helpful summaries of key books. This is especially appropriate now in light of Freire's death in April 1997. He is already greatly missed, but the struggle to attain the societal goals he identified as the purposes of liberationist education will continue to need his vision, counsel, and strategies. The many and complex dimensions of that struggle he describes as follows: Just as I could never accept that the fight for liberation could be restricted to the struggle of individuals, I could never accept that it could be reduced to the fight of women against men, of blacks against whites. ... The fight is not, as I said in the previous letter, for a democratic society so perfect it suppresses sexism, racism, and class exploitation once and for all. The fight is for the
The 1998 Neuroendocrine Workshop on Stress: a Report on the American Neuroendocrine Society Annual Workshop.

The existence of non-peptide CRH antagonists causes one to focus on the clinical usefulness of these molecules in melancholia, obesity or cancer. However, the diverse array of potential functions of CRH in humans first requires closer scrutiny. For example, knocking out CRH gene expression in experimental animals causes a preservation of basal ACTH secretion and a compromised but functional adrenal cortex. The presence of a functional cortex is the result of chromaffin cells residing in the cortex (S. Bornstein, Bethesda, MD, USA). These cells secrete catecholamines that act in a paracrine manner to elicit cortisol synthesis and release. The presence of chromaffin cells in the cortex might account for adrenal tumor release of cortisol in situations where ACTH action is blocked. Further studies are necessary to understand the pathophysiological significance of cortical chromaffin cells. Obesity is characterized by insulin resistance, overactivity of the HPA axis and inhibition of the hypothalamic–pituitary–gonadal axis. The newly described adipose tissue hormone, leptin, is a central player in obesity. Many obese individuals are resistant to the actions of leptin or lack this hormone completely. Leptin also inhibits the HPA axis by acting on hypothalamic targets. The interplay between leptin and the HPA axis is important in understanding the metabolic regulation of the HPA axis (J. Flier, Boston, MA, USA). Finally, a large literature supports the notion that depressed patients have dysfunctional HPA axis activity. However, closer scrutiny of depressed patients over a longer period reveals that the hypersecretion of cortisol in these patients occurs for only several days out of each nine days. Nevertheless, the ACTH increment may be markedly increased. Sampling blood in depressed individuals does not indicate adrenal insensitivity or a pituitary ACTH defect. Therefore, the primary defect in depressed patients might reside at CRH producing CNS loci other than the hypothalamus (J. Licinio, Bethesda, MD, USA).While our understanding of the regulation of the stress response has advanced considerably since the discovery of CRH in 1981, a number of questions about the interplay between the HPA axis and the function of the brain remain to be addressed. For example, what is the molecular basis for aging-induced cognitive decline and how do CRH mechanisms in the amygdala participate in anxiety behaviors? Hopefully, by the time the next Neuroendocrine Workshop on Stress takes place the answers to these questions will be available.
Tachykinins can partly explain the link within the neuroendocrine‐immune‐hematopoietic axis: novel role for mesenchymal stem cells

The tachykinins are among major regulators of bone marrow (BM) functions. The BM is resident to two stem cells: hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). The adult BM has a finite number of HSCs that are required to replenish the immune system throughout life. MSCs surround BM vasculature, while HSCs are located close to the endosteal regions. The mechanisms by which the tachykinins regulate hematopoiesis require further research. Innervated fibers in the BM form synapse-like structures with MSCs. We propose that tachykinin-mediated effects on MSCs are relevant to hematopoiesis, because MSCs: 1) generate hematopoietic supporting stromal cells, 2) regulate the movement of cells in and out of the BM, and 3) regulate inflammatory responses in the BM. This study focuses on the truncated tachykinin receptor (NK-1-Tr). Its expression and regulation on MSCs mirrors the brain, but contrasts BM stroma. NK-1-Tr is predominantly expressed on MSCs. Because of limited receptor desensitization, we propose that NK-1-Tr on MSCs could allow rapid responses to the tachykinins so as to maintain the vascular/barrier functions of the BM, regulate immune responses to infectious agents that could be threat to BM failure, and respond to rapid loss of blood. Part of the mechanisms by which the tachykinins regulate MSCs functions involve novel interactions between IFN-γ and MHC class II. The findings described in this study hold clues to the role of tachykinins on hematopoiesis and adult stem cell functions in the BM. This report adds to an understanding of the crosstalk within the neural-immune-hematopoietic axis.
Chronic insulin administration elevates blood pressure in rats.

To examine the relative contribution of dietary glucose and infused insulin on blood pressure, we administered a 4% glucose supplement (in drinking water) with and without insulin infusion (15.8 nmol [2.2 U]/d via osmotic minipump) to male Sprague-Dawley rats (n = 6). We also tested the effect of the sympatholytic agent clonidine on rats receiving glucose and insulin. Blood pressure and heart rate were recorded via a novel radio telemetry system. Experiments were performed using a crossover design with three animals receiving treatment and three receiving vehicle for 10 days. After a 10-day washout period, the groups were reversed, and the experiment was repeated. Blood samples for insulin and glucose were drawn throughout the study. Systolic and diastolic blood pressures increased (by 6.0 +/- 1.2 and 2.2 +/- 1.3 mm Hg, respectively) in the animals given glucose alone in association with an increase in plasma insulin. However, blood pressure increased more rapidly and to a greater extent, systolic by 8.6 +/- 0.7 mm Hg and diastolic by 2.9 +/- 1.1 mm Hg, during the insulin treatment that raised plasma insulin above the levels observed during glucose feeding alone. Heart rate increased equally during both treatments. The average change in blood pressure and average plasma insulin during the infusion were correlated (r = .72, P = .009). Blood pressure dropped during the week following discontinuation of the insulin infusion. On rechallenge with insulin and glucose, blood pressure again rose and then decreased after termination of the insulin and glucose administration. Clonidine prevented the rise in blood pressure and heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)
Facile synthesis of optically active 2-hydroxymethyl-4-methylene-cyclohexanol. De novo synthesis of dideoxycarbocyclic sugars☆

Treatment of the olefinic epoxy alcohol 4 with diethylaluminum fluoride gives the hydroxymethyl methylenecyclohexanol 5 in yields of 60–75% rather than the other possible epoxide opening product 6 presumably due to a geometrical constraint similar to that in Baldwin's rules for ring closure.
Role of Brachytherapy in Treatment of Head and Neck Malignancy

Brachytherapy is an important armament available to the radiation oncologist treating cancers occurring in the head and neck region. It is all the more important in this era of organ preservation and improving quality of life (1,2). There are very few sites in the body where locoregional control is so vital to ultimate quality of life, organ function, and survival as in head and neck cancer. Brachytherapy permits dose intensification specifically to the tumor site while minimizing damage to the surrounding normal tissue and organs (3,4). This leads to an increased therapeutic ratio, while the patient also stands to gain functionally, psychologically, and cosmetically.
Congenital Scoliosis of a Bottlenose Dolphin

There are many reports of cetaceans with deformed and twisted bodies. Skeletal pathology descriptions have shown changes to axial skeletons because of injury, trauma, or disease. We present a bottlenose dolphin (Tursiops truncatus) that shows characteristic patterns of congenital skeletal deformity, including malformed vertebrae, ribs, and sternum. These malformations were consistent with segmentation and formation defects arising during early embryonic development, with a resulting cascade of deformity and compensatory pathology. In spite of severe deformities, the dolphin lived 18 yr, raised two calves, and likely would have lived longer had she not succumbed to sepsis and the piercing of the aorta caused by a stingray barb.
SELECTIVE GUIDE TO CURRENT REFERENCE SOURCES ON TOPICS DISCUSSED IN THIS ISSUE

(2000). SELECTIVE GUIDE TO CURRENT REFERENCE SOURCES ON TOPICS DISCUSSED IN THIS ISSUE. Journal of Addictive Diseases: Vol. 19, No. 4, pp. 85-98.
A distributed omnidirectional vision sensor

We describe an omnidirectional vision sensor for vehicle applications such as driver assist systems. The system is composed of four hyperbolic mirrors and uses a single camera to image the 360/spl deg/ scene around the vehicle. This is achieved by having each of the hyperbolic mirrors image about one third of the field of view, and having all four of them sharing one common focal point, where an imaging device is positioned. Several constraints and requirements were taken into consideration in the design of the distributed omnidirectional system. First, the design that we present can practically be mounted on a commercial vehicle. Second, it satisfies - to an approximation - the single viewpoint constraint. Third, it requires a single camera to image the whole field of view. A simulation was also done to plot the field of view as a function of the various system parameters.
Encoding variability in mediated transfer

The encoding variability (EV) of the B terms (mediators) was varied in an attempt to contrast the mechanisms of unlearning and mediation in the three-stage chaining paradigm, i.e., A-B, B-C, A-C, and the corresponding pseudomediation groups. It was thought that the pseudomediation hypothesis might apply only for low-EV B terms, where unlearning might be more likely. Test-list performance indicated mediated facilitation, and there was a difference of comparable magnitude for the pseudomediation groups, but neither was influenced by the EV of the mediating terms.
Late Holocene dispersal and accumulation of terrigenous sediment on Poverty Shelf, New Zealand

We use coupled numerical models (HydroTrend and SedFlux) to investigate the dispersal and accumulation of sediment on Poverty Shelf, North Island, New Zealand, during the past 3 kyr. In this timeframe, we estimate that the Waipaoa River system delivered � 10 Gt of sediment to Poverty Shelf, 5^10% of which was transported to the outer shelf and continental slope.The domain of the two -dimensional model (SedFlux) is representative of a 30 km traverse across the shelf. Comparing the model output with seismic re£ection data and a core obtained from the middle shelf shows that, without extensively modifying the governing equations or imposing unrealistic conditions on the model domain, it is possible to replicate the geometry, grain size and accumulation rate of the late Holocene mud deposit.The replicate depositional record responds to naturally and anthropogenically induced vegetation disturbance, as well as to storms forced by long-period climatic events simulated entirely within the model domain.The model output also suggests that long-term £uctuations in the amount and caliber of river sediment discharge, promoted by wholesale changes in the catchment environment, may be translated directly to the shelf depositional record, whereas short-term £uctuations conditioned by event magnitude and frequency are not.Thus on Poverty Shelf, as well as in depocenters on other active continental margins which retain a much smaller proportion of the terrigeneous sediment delivered to them, £ood-generated event beds are not commonplace features in the high-resolution sedimentary record.This is because the shelf sedimentary record is in£uenced more by the energy available to the coastal ocean which helps keep the sediment in suspension and facilitates its dispersal, than by basin hydrometeorology which determines the turbidity and velocity of the river plume.
Management of node-positive melanoma in the era of sentinel node biopsy

Regional lymph node metastasis is a powerful predictor of decreased overall survival from malignant melanoma. However, the therapeutic value of elective node dissections and the role of adjuvant therapy for node-positive disease have been highly controversial. Sentinel lymph node biopsy has reshaped the debate by allowing for staging of the regional lymph nodes with less morbidity and greater accuracy. This review summarizes the current consensus on the management of node-positive melanoma in the era of sentinel lymph node biopsy.
Presynaptic inhibition compared with homosynaptic depression as an explanation for soleus H-reflex depression in humans

The H-reflex is depressed for seconds if elicited following a single H-reflex or train of H-reflexes. Presynaptic inhibition from flexor afferents (tibialis anterior) onto soleus Ia afferents elicited by either single or trains of stimuli had no effect on the soleus H-reflex on a time scale of seconds. Postsynaptic inhibition was also excluded by magnetic stimulation tests that showed that the excitability of the motoneuron pool was not changed at latencies within a range of seconds. Homosynaptic depression localized at the presynaptic terminal seems to be the mechanism behind the H-reflex depression in humans.
THE CAJON PASS SCIENTIFIC DRILLING EXPERIMENT: OVERVIEW OF PHASE 1

The Cajon Pass Scientific Drilling Project is a broad, interdisciplinary experiment involving over two dozen principal scientists. Phase I of drilling, coring and downhole experimentation began Dec. 8, 1986 and ended April 2, 1987 with the hole at a depth of 2115 m, 82 m of core recovered and a wide range of downhole experiments successfully completed. In this paper we briefly outline the scientific motivation for the project and provide an overview of the scientific program. We also indicate some of the varied research areas in the earth sciences where data obtained in this experiment will provide unique and important insight into active in situ processes, regional geologic structure, and rock and fluid composition and origin.
One day vs. two days of prophylactic antibiotics in patients undergoing major head and neck surgery.

Thirty patients undergoing major head and neck sugery were prospectively randomized to receive moxalactam (30 mg/kg) before surgery and for either 3 or 6 doses total postoperatively. Wound infection criteria were carefully specified and serum drug levels were monitored. Overall infection rate was 3%; the single infection occurred in a patient randomized to the 3 dose protocol. There was no statistically significant difference in infection rates between the two groups. Drug serum levels between the groups did not differ and none of the patients developed significant drug side effects. We conclude that short course prophylaxis is equally effective as more prolonged therapy. Our wound infection rate compares favorably with previous studies and supports the use of moxalactam as a prophylactive antibiotic in major head and neck surgery.
Evolution of hemostatic agents in surgical practice.

Objective : Topical hemostatic agents are used in a wide variety of surgical settings, and the evolution of this class of surgical tools is an interesting topic. We reviewed and outlined the historical progress of topical hemostats into present day surgery and urology, and highlight opportunities for future research. Materials and Methods : A MEDLINE search of all available literature concerning several classes of topical hemostatic agents was performed. Fibrins sealants, Gelatin sponge hemostatics, cyanoacrylate adhesives, oxidized regenerated cellulose, and microfibrillar collagen were included. References were chosen from a broad range of surgical literature. Results : Topical hemostatic agents have historically taken advantage of a wide variety of mechanisms for hemostasis. Fibrin sealants have a rich history and large potential for further applications. Gelatin sponge hemostatics have been widely used since their introduction, but have changed little. Cyanoacrylate adhesives have a unique mechanism and opportunity for novel applications of existing products. Oxidized cellulose was original in the use of plant-based components. Microfibrillar collagen hemostats have evolved to a wide variety of formats. Conclusions : A review of the evolution of topical hemostatic agents highlights opportunities for potential novel research. Fibrin sealants may have the most opportunity for advancement, and understanding the history of these products is useful. With the drive in urology for minimally invasive surgical techniques, adaptation of topical hemostatic agents to this surgical approach would be valuable and offers an opportunity for novel contributions.
UNIFIED DESCRIPTION OF INCONGRUENT REACTIONS AND MINERAL SOLUBILITIES AS A FUNCTION OF BULK COMPOSITION AND SOLUTION pH IN HYDROTHERMAL SYSTEMS

Depiction of mineral solubilities on isobaric isothermal bulk composition - pH diagrams facilitates considerably the conelation of the consequences of irreversible reactions with the solubilities of incongruent reaction products. The reaction-progress (f) is related to the bulk composition variable (r1", which has units of moles (kg HzO)-r) by the stoichiometries of the irreversible reactions and the relative rates of reaction of the reactant minerals. To illustrate the advantages of using diagrams of this kind to describe simultaneously mineral solubilities, phase relations, and mass transfer resulting from reaction of minerals with hydrothermal fluids in both open and closed systems, equilibrium solubilities of stable minerals in the system K2O-Na2O-AI2O3-SiO2H2O were computed as a function of pH in NaCl-HClNaOH-H2O solutions in which r1?Nacl = 0.01 or 1.0 at various pressures and temperatures of geological interest. These solubilities were then plotted together with representative reaction paths on ,?AI2Si2O5(OH)4 - pH' 4KAIlsi?orn(OH)? - PH, 4retsiron - PH' and 45*tt',ot pH dialgrdms. Considerationbf these diagrams indicates that kaolinite, muscovite, and K-feldspar dissolve congruently only over relatively narrow langes of solution pH. Above and below the pH limits of these ranges, the rninerals dissolve incongruently to form quartz, diaspore, or aluminosilicates. Albite dissolves incongruently over the entire range of solution pH from zero to 12. Changes in solution composition and the identities and number of moles of minerals that precipitate and dissolve along incongruent reaction paths can be assessed directly from bulk composition - pH diagrams, which can also be used
Living in Harmony with Nature: Complication of Climate Change and Governance

Climate change, a coupled natural and human system, is perhaps the greatest challenge facing society as it is global, but it will affect regions and localities in different ways. Anthropogenic activities have altered the natural climate system. Changing climate alters human activities. This feedback loop is nonlinear and effects are amplified in unknown ways that may lead to unexpected tipping points both in global climate and viability of society. We must find ways, and soon, to adapt to changing climate to sustain social systems. Human systems are coupled to, and indeed dependent upon, natural systems; we need to conduct climate change research that integrates studies of both systems. And we need to apply what we learn about these systems to decisions that get made.
Structure, Expression, and Evolution of Growth Hormone Genes

Publisher Summary This chapter discusses the structure, expression, and evolution of growth hormone genes. Growth hormone is a member of a family of polypeptide hormones that share both sequence homology and some biological activities. In humans, growth hormone, which is synthesized by the somatotrophs of the anterior pituitary, is very homologous to chorionic somatomammotropin, which is synthesized by the syncitio-trophoblast layer of the placenta. These two are much more distantly related to the third member of the family, prolactin, which is synthesized by the mammotrophs of the anterior pituitary. The synthesis and release of these peptide hormones is regulated by a variety of factors. Synthesis of growth hormone is stimulated by steroid hormones and thyroid hormones. The rGH gene is unique in the haploid rat genome, but there are approximately seven hGH related genes in the haploid human genome. Only two protein products, hGH and hCS, are known to be encoded by these multiple human genes. The rGH gene has been examined in various functional states. In both the pituitary and the brain, the gene shows a lowered level of methylated cytosine residues, a state which has been correlated with active transcription in other gene systems.
Lymph node targeting and therapy in breast cancer: A novel intralymphatic drug delivery system for treatment of locally metastatic breast cancer

C123 Overview: Early breast cancer initially metastasizes to the axillary lymph nodes; we hypothesized that lymphatically targeted cisplatin carriers will increase the localized dose in lymph metastases and decrease systemic toxicities. Background: Breast cancer is the second leading cause of cancer deaths in women today (after lung cancer). Since breast cancers spread initially to regional lymph nodes prior to systemic spread, adequate evaluation and treatment of the axillary lymph nodes is paramount in early stage disease. One significant problem with current therapy is the side effects chemotherapy agents create systemically either alone or in combination. To date no chemotherapy strategy is targeted to treating intralymphatic spread alone. There is, therefore, a critical need to develop novel drug delivery methods allowing chemotherapeutic agents to remain intralymphatically at therapeutic levels for their duration of action. Methods: Hyaluronan (HA) is a highly biocompatible and nonimmunogenic polymer that follows lymphatic drainage from the interstitial spaces. We formed complexes of HA and cisplatin by a non-covalent conjugate. We determined in vitro release rate of cisplatin from conjugates and cytotoxicity against MDA-MB-231 and MCF7 human breast cancers in cell culture. Complexes were injected subcutaneously into the right upper mammary gland of female Sprague-Dawley rats and the distribution of conjugates determined by atomic absorption spectometry. Results: Conjugates of cisplatin and HA contained up to 26% w/w of cisplatin and released drug with pseudo first order kinetics with a half-life of 10 hours in saline. Cisplatin-HA conjugates had high anti-tumor activity similar to the free drug: HA-cisplatin IC50 7 mcg/mL (cisplatin basis) in MCF7 and MDA-MB-231 cells (free cisplatin IC50 7 mcg/mL). HA-cisplatin conjugates were well tolerated in rodents with no signs of injection site morbidity or major organ toxicity after 24 hours and significantly increased localization compared to cisplatin in saline controls. Conclusions: Cisplatin-HA conjugates demonstrate antiproliferative efficacy similar to standard cisplatin formulation in a breast cancer model in vitro. While toxicity profiles of this nanoparticle delivery conjugate are promising, further evaluation of antitumor efficacy and survival in an in vivo model will be required to validate the benefit of this novel therapy. This contribution is expected to be significant in providing a novel intralymphatic drug delivery method in breast cancer to preferentially treat at-risk regional lymph nodes and avoid systemic toxicities.
Structural organization of GABAergic circuitry in ectotherm retinas.

Publisher Summary This chapter discusses visualizing gamma-aminobutyric acid–releasing (GABAergic) neurons, the scope of GABAergic organization throughout all vertebrates, and the general principles of GABAergic control throughout the retina. The first step in describing GABAergic circuits is to provide compelling evidence that GABAergic neurons themselves can be characterized with high functional and structural fidelity. There are three main cell biological mechanisms underlying the rapidity, sustainability, and potency of GABAergic neurotransmission: (1) the abilities of neurons to synthesize and mobilize GABA for release, (2) the precise and rapid control of extracellular neurotransmitter levels by potent pre-synaptic neurotransmitter/Na+ symporters, and (3) the mediation of rapid postsynaptic conductance or synaptic efficacy changes by specific GABA receptors. Each of these features can theoretically be associated with visualization techniques. GABA immunoreactivity has been mapped to many vertebrate retinas, but the general patterns of organization in non-mammalians/ectotherms are easily demonstrated. A clear population of GABA immunoreactive horizontal cells can be seen in most species.
Hypertension and Related Cardiovascular Disease Burden in China

Abstract Background With rapid economic development, urbanization, and an aging population, cardiovascular diseases (CVDs) have become the leading cause of death in China. Objectives The aim of this study was to provide a comprehensive review on the prevalence, awareness, treatment, and control of hypertension (HTN) as well as blood pressure (BP)-related morbidity and mortality of CVD in Chinese adults over time. Findings The prevalence of HTN in China is high and increasing. Recent estimates are variable but indicate 33.6% (35.3% in men and 32% in women) or 335.8 million (178.6 million men and 157.2 million women) of the Chinese adult population had HTN in 2010, which represents a significant increase from previous surveys. BP-related CVD remains the leading cause of death in Chinese adults, with stroke being the predominant cause of cardiovascular deaths. Of those with HTN, 33.4% (30.4% in men and 36.7% in women) were aware of their condition, 23.9% (20.6% in men and 27.7% in women) were treated, and only 3.9% (3.5% in men and 4.3% in women) were controlled to the currently recommended target of BP Conclusions The prevalence of HTN is high and increasing, while the control rate is low in Chinese adults. Combatting HTN and BP-related morbidity and mortality will require a comprehensive approach at national and local levels. The major challenge moving forward is to develop and implement effective, practical, and sustainable prevention and treatment strategies in China.
Wave Polymerization During Vapor Deposition of Porous Parylene-N Dielectric Films

Parylene-N films vapor deposited near liquid nitrogen temperature (77 K) undergo a unique ‘wave’ polymerization process in which a rapidly moving reaction front is apparent as the film changes from translucent to optically opaque. This moving reaction front produces a highly porous polymer film. The porosity of these films is approximately 80%. By capturing the wave process on video we have quantified the moving ‘wave’ velocity, which averages 11 cm/s. Timeaveraged deposition rates of the resulting opaque, porous films are more than 8 μm/min. This rate is more than two orders of magnitude greater than the measured deposition rates of nonporous films that are deposited at higher temperatures, at otherwise fixed conditions of monomer delivery rate and deposition chamber pressure.
The Impact of Chylothorax on Nutrition and Growth in Neonates Following Congenital Diaphragmatic Hernia Repair

Infants with congenital diaphragmatic hernia (CDH) have prolonged respiratory failure, loss of lean body mass, and failure to thrive. Chylothorax is an uncommon complication after CDH repair. The purpose of this study was to determine whether the presence of chylothorax predisposes infants with CDH to worse nutritional outcomes. We performed a retrospective cohort study of 164 newborns with …
Hatching of Sod Webworm Eggs in Relation to Low Temperatures

Eggs of Chrysoteuchia topiaria (Zeller), Crambus pascuellus floridus (Zeller), and Pediasia trisecta (Walker) were exposed to temperatures of 25, 15, 10, 4, and 10°C. Only those of P. trisecta hatched after exposure to 4°C for 30 days, while none hatched after exposure to –10°C. Eggs of none of the species hatched after exposure to 4 and 10°C for 60 days. Pre-exposure and postexposure conditioning had no significant effect on percent hatch of P. trisecta eggs, while length of exposure period had a significant effect.