cssi/SciSciGPT-SciSciNet huggingface dataset:
Chapter 9 – PWAS Resonators

This chapter discusses PWAS resonators. The chapter starts with linear PWAS resonators for which a detailed 1-D analysis is performed for both mechanical and electrical responses. The associated resonances are identified. Closed-form solutions are derived for the electromechanical (E/M) impedance and admittance and compared with experiments. The circular PWAS resonators are discussed next; a detailed 2-D analysis of the mechanical and electrical responses is performed in cylindrical coordinates. Axisymmetric closed-form solutions are derived in terms of Bessel functions. The associated resonances of a circular PWAS resonator are identified. Formulae for the E/M impedance and admittance of circular PWAS resonators are derived and compared with experiments. Numerical solutions based on the coupled-field (multi-physics) finite-element method (FEM) are also developed. Rectangular and circular PWAS resonators are analyzed and compared with experimental results. The last part of the chapter deals with constrained PWAS resonators having a complex-valued frequency-dependent structural stiffness at the boundary. Analytical formulae for the E/M impedance and admittance are derived for both linear (1-D) and circular (2-D) geometries with the complex-valued dynamic stiffness ratio as parameters. The analysis of constrained PWAS resonators paves the road for the analysis, in later chapters, of structurally bonded PWAS transducers that act as in situ modal sensors through the E/M impedance technique.
A Scientific Basis for Designation of the Northeast Canyons and Seamounts Marine National Monument

The Northeast Canyons and Seamounts Marine National Monument (NEC&SMNM) was designated by President Barack Obama in 2016, using his authority under the Antiquities Act of 1906. The Act allows a President to proclaim as national monuments “historic landmarks, historic and prehistoric structures, and other objects of historic or scientific interest” that are “upon the lands owned or controlled” by the United States but to reserve each designation to “the smallest area compatible with the proper care and management of the objects to be protected.” Protection in general excludes commercial scale extraction and is in perpetuity. Analyses of physiographic and ecological data sets facilitated assessment of the conservation benefits of protections for the NEC&SMNM and syntheses of the ecological literature describe processes that operate in continental margin and deep-sea settings. Results indicate that the current monument designation is an area of high diversity and ecological connectivity across depths and along the continental margin. The monument boundaries contain hot spots (areas of high abundance and species richness) for seafloor communities (inclusive of benthic invertebrate and demersal fish) as well as marine mammals in the epipelagic. Many species are sensitive to disturbance and vulnerable to human activities (e.g., deep-sea corals, sponges) with very long recovery times and extremely low resilience. The monument contains at least nine exemplars of offshore northwest Atlantic marine wildlife communities and habitats (e.g., deep shelf invertebrates, shelf fish, deep sea corals and sponges in canyons and on seamounts, deep sea fish, chemosynthetic communities, deep sea soft sediment, shelf edge cetaceans & seabirds). The region is relatively undisturbed and can serve as a reference site to focus future research on ecological processes in an increasingly industrialized ocean and one subject to the synergies of regional climate effects. These results suggest that there is great potential for discovery and novel research in this first Atlantic Ocean Marine National Monument.
Convergent and discriminant validity of the Emotional Eating Scale Adapted for Children and Adolescents (EES-C) Short-Form.

Abstract Background Emotional eating is associated with a number of negative outcomes in children and adolescents, including higher levels of loss of control eating (i.e., the inability to control the amount of food consumed). There is a need for psychometrically sound and feasible measures that assess emotional eating in children and adolescents. The purpose of the current study was to evaluate the convergent and discriminant validity of the 10-item Emotional Eating Scale Adapted for Children and Adolescents (EES-C) Short-Form in a community sample of adolescents. We also sought to assess the reliability and structural validity of this measure. Methods Participants were 128 adolescents ages 13 to 19 years (mean age = 15.10 years; SD = 2.09; 53.9% female). Most participants fell within the healthy BMI range (58.6%). Participants completed the EES-C Short-Form, the loss of control eating section of the Questionnaire on Eating and Weight Patterns-Adolescent Version 5, the Gratitude Questionnaire-Six-Item Form, and a demographic questionnaire. Results Convergent validity of the EES-C Short-Form was supported in that adolescents who endorsed loss of control eating reported significantly greater levels of emotional eating (mean = 24.37; SD = 8.94) compared to adolescents who did not endorse loss of control eating (mean = 19.42; SD = 7.33; p ≤ .01; d = 0.61). The EES-C Short-Form was significantly correlated with a subjective measure of loss of control eating (rs = −0.255; p = .004), further demonstrating convergent validity. The EES-C Short-Form exhibited discriminant validity as demonstrated by a small, non-significant correlation with the Gratitude Questionnaire-Six-Item Form (rs = 0.086; p = .347). The EES-C Short-Form demonstrated acceptable reliability (Cronbach's alpha = 0.84; Ordinal alpha = 0.88; Coefficient omega = 0.85) and a unidimensional factor structure (CFI = 0.98; NNFI = 0.98; RMSEA = 0.08). Conclusions These data contribute to the existing research that support the EES-C Short-Form as a reliable and valid measure for assessing emotional eating in children and adolescents.
Power and sample size for observational studies of point exposure effects

Inverse probability of treatment weights (IPTWs) are commonly used to control for confounding when estimating causal effects of point exposures from observational data. When planning a study that will be analyzed with IPTWs, determining the required sample size for a given level of statistical power is challenging because of the effect of weighting on the variance of the estimated causal means. This paper considers the utility of the design effect to quantify the effect of weighting on the precision of causal estimates. The design effect is defined as the ratio of the variance of the causal mean estimator divided by the variance of a naive estimator if, counter to fact, no confounding had been present and weights were not needed. A simple, closed-form approximation of the design effect is derived that is outcome invariant and can be estimated during the study design phase. Once the design effect is approximated for each treatment group, sample size calculations are conducted as for a randomized trial, but with variances inflated by the design effects to account for weighting. Simulations demonstrate the accuracy of the design effect approximation, and practical considerations are discussed.
Diverse, culturally rich approaches to family care in the United States

Abstract Caregivers and caregiving needs are growing and diversifying in the United States (US). However, the health system is not prepared to accommodate this diversity. Interventions and supports often are not adequately tailored to meet the cultural needs of older adults and their caregiving teams. The limited interventions available and tested with racial/ethnic minority populations often fail to capture and report culturally tailored perspectives. The purpose of this chapter is to describe how culture influences caregiving. Cultural domains such as norms, values, and cultural meaning are discussed and case examples from the African American, Hispanic/Latino, and immigrant communities are presented to demonstrate how these cultural domains interact with the sociocultural environment to impact care. Examples of culturally tailored programs in the US are given to demonstrate how such strategies can benefit families. Although cultural tailoring of interventions is necessary and recommended, culture itself is dynamic and varied, which makes it impossible to identify all the unique characteristics of a specific culture. The practice of cultural humility and fluidity is offered as an approach to facilitate cultural understanding and awareness in everyday care experiences.
Identification and characterization of a new 34 kDa MORN motif-containing sporozoite surface-exposed protein, Cp-P34, unique to Cryptosporidium.

Abstract Despite the public health impact of childhood diarrhea caused by Cryptosporidium, effective drugs and vaccines against this parasite are unavailable. Efforts to identify vaccine targets have focused on critical externally exposed virulence factors expressed in the parasite s invasive stages. However, no single surface antigen has yet been found that can elicit a significant protective immune response and it is likely that pooling multiple immune targets will be necessary. Discovery of surface proteins on Cryptosporidium sporozoites is therefore vital to this effort to develop a multi-antigenic vaccine. In this study we applied a novel single-domain camelid antibody (VHH) selection method to identify immunogenic proteins expressed on the surface of Cryptosporidium parvum sporozoites. By this approach, VHHs were identified that recognize two sporozoite surface-exposed antigens, the previously identified gp900 and an unrecognized immunogenic protein, Cp-P34. This Cp-P34 antigen, which contains multiple Membrane Occupation and Recognition Nexus (MORN) repeats, is found in excysted sporozoites as well as in the parasite s intracellular stages. Cp-P34 appears to accumulate inside the parasite and transiently appears on the surface of sporozoites to be shed in trails. Identical or nearly identical orthologs of Cp-P34 are found in the Cryptosporidium hominis and Cryptosporidium tyzzeri genomes. Except for the conserved MORN motifs, the Cp-P34 gene shares no significant homology with genes of other protozoans and thus appears to be unique to Cryptosporidium spp. Cp-P34 elicits immune responses in naturally exposed alpacas and warrants further investigation as a potential vaccine candidate.
Tentativa II | Attempt II

Trata-se de um ensaio visual onde o autor nos convida para com ele embarcar em uma viagem/meditacao entre imagens e discursos, depois de sermos, junto dele, confrontados com o punctum de post-its e cartoes postais de sua parede. As diminutas notas para si mesmo e as pinceladas sinuosas de uma pintura de Van Gogh descortinam uma investigacao tateante sobre o problema da nao-figuracao (que Salomao designa como abstracao) nas artes e sobre o trabalho psiquico do sintoma: cerne da subjetividade, deiscencia existencial e origem do discurso, conforme pensou Lacan. Nesse sentido, os artistas e escritores loucos seriam, na melhor tradicao artistica holderliniana, aqueles capazes de capturar um pequeno brilho/acontecimento na realidade que teima em se apagar.
Y572 is a functionally important amino acid for autoinhibition of the FLT3 receptor tyrosine kinase

1458 FLT3 is a member of the receptor tyrosine kinase III subfamily and shares strong sequence and structural similarities with c-Kit, FMS, PDGFRα and PDGFRβ. FLT3 plays an important role in hematopoiesis, and is also involved in the pathogenesis of hematopoietic malignancies. Mutations of FLT3 gene have been found in about 35% of acute myeloblastic leukemia (AML) patients, most commonly as in frame insertions of variable length (internal tandem duplications, or ITDs) in the juxtamembrane (JM) domain. These mutations result in receptor autophosphorylation without ligand stimulation, which then leads to the constitutive activation of many down stream targets/signaling pathways. It is likely that these ITD mutations cause the receptor to adopt an “active configuration” despite the absence of ligand. Studies from the crystal structure of the FLT3 cytoplasmic domain (Griffith et al, 2004. Molecular Cell. 13:169-178) have suggested the JM domain interacts with the kinase domain and plays a critical role in maintaining the kinase in an inactive configuration in the absence of ligand. These studies further suggested that the first amino acid of the JM domain, Y572, is a key element for the kinase autoinhibition by forming a stable network with the surrounded kinase subdomains. To test this hypothesis, two different FLT3 cDNAs harboring mutations at Y572, Y572N or Y572V, were each introduced into the growth factor IL3 dependent murine Ba/F3 cells, and stable, polyclonal cell lines were generated. These Ba/F3 cells could proliferate in the absence of IL3, and the mutated receptors were auto-phosphorylated in the absence of FLT3 ligand stimulation, with resulting constitutive activation of STAT5 and ERK kinases. Exposure to the FLT3 inhibitor PKC412 (Novartis Pharma AG), resulted in an inhibition of the growth of both Ba/F3- FLT3-Y572N and Ba/F3- FLT3-Y572V cells with an IC50 of 5 nM; reduced autophosphorylation of the mutant receptors, and inhibited STAT5 and ERK phosphorylation. These results demonstrate that, like ITD mutations in the JM domain, the mutations of Y572 are sufficient to confer constitutive kinase activity to the receptor, and suggest that any mutation that interferes with the ability of FLT3 to maintain an inactive configuration of the JM/kinase domain is likely to be transforming.
“Visual” Binaries in the Twenty-First Century

For thirty years, speckle interferometry has continued and extended the work of the visual binary star observers of the past century. What does it offer as we look to the future? Because of the rise of space astrometry and the much more precise parallaxes that these satellites are likely to achieve, one of the most difficult aspects of determining reliable stellar masses from visual orbits (i.e. the system distance) will most likely fall in the next decade. In addition, Hipparcos has discovered more than 3400 new double star systems, some fraction of which is certainly gravitationally bound. These and other recently discovered systems give us a chance to significantly improve our knowledge of stellar masses, the mass-luminosity relation, and binary statistics, if their orbits can be determined in sufficient detail. Regular speckle and spectroscopic observations at smaller telescopes, in combination with ultra-precise parallaxes, therefore hold the promise of providing the fundamental empirical calibration of stellar structure and evolution theory that the first visual binary star observers had envisioned.
Chapter 24. Neutrophil Elastase

Publisher Summary This chapter discusses the biochemical properties, roles in normal physiology, and possible involvement in pathological states of the elastase from human neutrophils. Human leukocyte elastase (HLE) is a serine proteinase,as evidenced by its inhibition by diisopropyl fluorophosphate, phenylmethyl sulfonyl fluoride, and alpha-1-proteinase inhibitor. It catalyzes the hydrolysis of substrate esters and amides, according to a mechanism, involving the formation and subsequent hydrolysis of a covalent acyl-enzyme. The importance of human leukocyte elastase as a pathogenic agent in a variety of disease states in man has been recognized. This has resulted in a surge of interest in defining the substrate specificity and designing potent synthetic inhibitors of HLE. α 1 -Proteinase inhibitor (α 1 -PI, α 1 -antitrypsin) is the most abundant serum proteinase inhibitor. In recent years, a variety of synthetic peptidic compounds have been reported as simple competitive and reversible inhibitors of HLE. Ultrastructural, cytochemical, and immunofluorescence studies of human neutrophils have demonstrated the presence of elastase primarily in the azurophilic granules and, also, in the nuclear envelope, golgi complex, endoplasmic reticulum, and mitocondria. In general, proteinases and esterases present in the cytoplasm and membranes of the leukocyte play an important role in the generation of and response to chemotactic stimuli. Elastase is one of the major fibrinolytic proteinases of the leukocyte. Early events in blood coagulation induce the active secretion of elastase from leukocytes. Neutrophil elastase has been implicated as a pathogenic agent in a number of disease states in man, most notably, pulmonary emphysema. Moreover, HLE is thought to play a causative role to the pathogenesis of rheumatoid arthritis, adult respiratory distress syndrome, glomerulonephritis, and cystic fibrosis.
Role of p53 and Rb in Ovarian Cancer

Ovarian cancer remains a major health concern worldwide, primarily in postmenopausal women. Among the most common genetic alterations in human sporadic epithelial ovarian cancer (EOC) are p53 mutations, defective retinoblastoma (RB) pathway (p16INK4a/RB) and activation of oncogenes such as c-myc, K-ras and Akt. Although these alterations are frequently associated with poor clinical prognosis, their specific contributions to EOC formation remain unclear. In order to gain a better understanding of the roles of these proteins in vivo, a number of mouse models have been generated, largely based upon inducing specific genetic lesions in the ovarian surface epithelium from which the majority of carcinomas are thought to arise in humans. Here, we review the role of tumor suppressor p53 and the Rb pathway in EOC with particular attention to association of p53 to high grade serous carcinomas as opposed to low grade and benign tumors. We also provide an overview of the utility and application of genetically engineered mouse models, in particular towards rational drug design and development of improved imaging techniques in ovarian cancer.
Channel noise scan by using simulations of voltage regulator noise to signals

In this paper, channel noise scan approach (CNS) is proposed to efficiently analyze the potential VR-signal coupling issue in the pre-silicon design and the post-silicon debug of the platform development. CNS is based on a new simulation methodology that includes the whole PCB with signals, voltage regulator (VR) networks, and the interaction between the two. The goal of this simulation methodology is to help platform developer to quantify the VR-signal coupling risk and find the outliers of the victim signal nets according to the board layout and the VR design. This methodology can also provide the ability for the designer to do performance/cost tradeoff, layout optimization. To systematically analyze the VR-signal coupling problems, both the frequency and time domain approaches have been developed to characterize the VR-signal coupling in different levels. The frequency domain approach can quickly point out potential issues and the time domain approach is proved to be consistent with the frequency domain but with more detail and intuitive information. A design flow is given to efficiently identify the outliers of victim signals by VR noise coupling impact. Designers can improve the layout based on channel noise scan results from the simulations.
Spontaneous non-rdar mutations increase fitness of Salmonella in plants

Proliferation of human enteric pathogens within alternate hosts, like plants, leads to temporal changes in gene expression and also selects for the phenotypic variants of the enterics that are presumed to be more fit within plants. Human enteric pathogens recovered from produce-borne outbreaks exhibit peculiar phenotypes, for example many of them do not display the rdar (red dry and rough) phenotype. The non-rdar phenotype results from mutations in cellulose and/or curli synthesis or regulation. How often these mutants arise, and whether they are more fit within plants is not entirely clear. We addressed this hypothesis by sequentially passaging the type strain of Salmonella enterica sv. Typhimurium ATCC14028 through tomatoes. Two spontaneous mutants defective in their ability to form red dry and rough colonies were further characterized. Even though attachment of the mutants to tomato surfaces was modestly reduced, they were 5- to 50-fold more competitive than the wild-type inside tomato fruits. Because the mutants were outcompeted by the wild-type on common laboratory media, and not in tomatoes, the lack of the rdar phenotype is probably beneficial within tomatoes. Recombinase-based in vivo expression tests indicate that the agfB and yihT genes were regulated differently in the mutants, although the corresponding mutations cannot fully account for the increased competitive fitness of the mutants. One of the variants has a mutated rpoS, which also reduced the expression of a SPI-5 effector encoded by sopB. A survey of the Salmonella strains recovered from produce outbreaks revealed that some were similarly non-rdar, likely containing rpoS mutations. This report indicates that the 'perfect storm' scenario, typically used to model outbreaks of produce-borne gastroenteritis, needs to account for the ability of the pathogen to rapidly evolve and adapt to the crop production environments.
Chronically Administered Acetaminophen and the Ischemia/Reperfused Myocardium

Male and female Hartley strain guinea pigs weighing 280 ± 10 g were given acetaminophen-treated water ad libitum for 10 days. Sham-treated control animals were given similar quantities of untreated tap water (vehicle-treated control group). On Day 10, hearts were extracted, instrumented, and exposed to an ischemia (low-flow, 20 min)/reperfusion protocol. Our objective was to compare and contrast ventricular function, coronary circulation, and selected biochemical and histological indices in the two treatment groups. Left ventricular developed pressure in the early minutes of reperfusion was significantly greater in the presence of acetaminophen, e.g., at 1 min, 40 ± 4 vs 21 ± 3 mmHg (P < 0.05). Coronary perfusion pressure was significantly less from 3 to 40 min of reperfusion in the presence of acetaminophen. Creatine kinase release in vehicle-treated hearts rose from 42 ± 14 (baseline) to 78 ± 25 units/liter by the end of ischemia. Corresponding values in acetaminophen-treated hearts were 36 ± 8 and 44 ±...
Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77E and N37E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies.
A Majority in the Lifeboat

In recent work, Ronald Dworkin has used a simple hypothetical to discredit the principle of majority decision. He imagines a lifeboat, overloaded, in which one passenger must be chosen to be thrown overboard in order to save the rest. Dworkin says that 'it would not be fair to hold a vote so that the least popular among them, for whatever reason, would be drowned. It would obviously be fairer to draw lots.' He thinks this shows that the principle of majority decision is not intrinsically fair and that it adds nothing to the legitimacy of a decision. He concludes from this that a definition of democracy which ties it tightly to majority-decision is misconceived. In this paper, I argue that Dworkin's example shows very little, and certainly not that. Majoritarians favor the use of the majority principle to decide general policy and legislation, not life and detah for partiuclar cases. If the passengers in the lifeboat disagreed about the principle to use to decide who should go overboard - some favoring decision by lot, some favoring the sacrifice of those who are so weakened they will die anyway - it would not be unfair or inappropriate to use majority-decision to determine that issue of principle. Dworkin makes no convincing argument against this, and his use of the lifeboat example fails to touch any of the moral considerations that democrats have thought made majority-decision attractive. Maybe there are other good arguments in Professor Dworkin's work against majoritarian democracy, but they are not found here.
Testing for Occupational Crowding in Eighteenth-Century British Agriculture

In the unskilled labor market of Industrial Revolution Britain, there was a distinct division of labor between the sexes. This occupational sorting may have been caused by gender discrimination, but, because men and women had different comparative advantages, it could also have been produced by a competitive market. This paper attempts to determine whether the division of labor resulted from discrimination in the form of occupational crowding by testing whether men and women were substitutes. Data on the employment of English farm servants in 1770 indicate that employers were willing to substitute male and female workers, which implies that the division of labor between the sexes was influenced by economic motivations, and was not determined by gender ideology alone.
Arithmetical problems and recursively enumerable predicates

It is an immediate consequence of results of Church and Godel that there exist arithmetical recursively unsolvable problems, that is, recursively unsolvable problems of the form [M](P = Q) where P and Q are polynomials and [M] is some finite sequence of existential and universal quantifiers. A question which is immediately raised by this result is whether there exist unsolvable problems of this form where [M] is some finite sequence of existential quantifiers only. As a matter of fact this question is easily seen to be closely related to the tenth problem in the famous list proposed by Hilbert in 1900.In this paper, we prove the existence of recursively unsolvable problems of the formwhere P and Q are polynomials with non-negative integral coefficients. As a matter of fact we show that every recursively enumerable predicate is of the form (1), and conversely that every predicate of the form (1) is recursively enumerable. While our result does not yield the recursive unsolvability of Hilbert's tenth problem, it is easily seen that any considerable improvement of our result would yield this unsolvability.The author wishes to take this opportunity to express his gratitude to Professors Alonzo Church and E. L. Post with whom he has had the privilege of discussing some of the questions involved in this paper. He also wishes to thank his friends Melvin Hausner and Jacob Schwartz who have made valuable suggestions.
Comment on "Nonequilibrium nozzle flow of a nitrogen-hydrogen mixture"

Clarence J. Harris* General Electric Company, Philadelphia, Pa. Ebrahim, N.A. and Hornung, H.G., "Nonequilibrium Nozzle Expansion of Carbon Dioxide from a High Enthalpy Reservior," AIAA Journal, Vol. 11, Oct. 1973, pp. 1369-1370. MacDermott, W.N. and Dix, R.E., "Mass Spectrometric Analysis of Nonequilibrium Airflows," AIAA Journal, Vol. 10, April 1972, pp. 494-499. Young, W.S., "Correlation of Chemical Freezing in a Freejet Expansion, "AIAA Journal, Vol. 13, Nov. 1975, pp. 1478-1482.
Protective effect of fibrin on tumour metastasis

Abstract As a potential explanation for the association between metastatic characteristics of tumour cells and their ability to induce fibrin formation, we hypothesize that fibrin deposition around tumour cells might prevent their recognition and lysis by natural killer (NK) or other cytotoxic effector cells. As the hypothesis predicts, we find that both anticoagulants (heparin or warfarin) and immune system stimulants (poly LC) inhibit formation of metastatic nodules in lungs of mice injected with tumour cells through the tail vein. Anticoagulants have no protective effect, however, in mice whose NK cells have been depleted by pretreatment with anti-asialo GM1 serum. Measurement of the elimination of freshly injected radiolabelled tumour cells from the lungs show that this rate is increased by both anticoagulants and immune system stimulation. Again, however, anticoagulants have no effect in NK-depleted animals. That this is due to fibrin deposition, not other blood elements, is confirmed by in vitro experiments: The ability of NK cells to kill tumour cells is inhibited when either cell type is premixed with fibrinogen and thrombin 20 min before the other cell type is added.
Isozyme variation in tropical trees: patterns of genetic organization

Tropical forests have long been of interest to biologists because of their high species diversity and their complicated patterns of community organization. The traditional notion of the rain forest as an ancient, unvarying archive of species has been challenged by a host of recent ecological studies which have demonstrated that tropical trees are diverse in their reproductive biology and dynamic in their population structure.
Servicing operations for the SIRTF Observatory at the Space Station

This paper describes the servicing requirements, plans, and proposed Space Station-based servicing operations for the Space Infrared Telescope Facility (SIRTF) Observatory. SIRTF is a cryogenically-cooled, long-life, one meter class space telescope which will be operated by NASA as a free-flying observatory for infrared astronomy, in the mid-1990's. To achieve its 5-year lifetime requirement (10 year goal), SIRTF must be replenished periodically with cryogenic helium and have its life-limited modular subsystems replaced; capability for contingency repair of warm components will also be provided in the Observatory design. A general description of the SIRTF Observatory is given, including options for the support systems (spacecraft). The overall servicing philosophy and plans are addressed with scheduling and needed support elements described. A proposed Space Station-based servicing scenario is described, including orbital transfer, servicing and checkout operations. A detailed description and timeline for liquid helium replenishment operations is provided, including a conceptual design and technology development program for the cryogenic helium transfer dewar (tanker). Finally, a preliminary SIRTF spares/logistics philosophy is outlined, including tradeoffs to be considered.
Crystalline Cellulose and Cotton Fiber Strength

The variation in the bundle fiber strength measurements of cotton (Gossypium hirsutum L.) fibers due to differences in cellulose crystallinity and chain length have not been examined. This study was conducted to determine the length of the cellulose chains (expressed as the weight-average molecular weight, M w ) in the crystalline microfibrillar fragments isolated from different cotton fiber and to relate these values to bundle fiber strength. Crystalline microfibrillar fragments were isolated by treating cotton fibers with acetic acid/nitric acid reagent. The crystalline cellulose was dissolved in a lithium chloride solution of N,N-dimethylacetamide
Relapsing post-transfusion purpura. A preventable disease

Post-transfusion purpura is an isoimmune disorder that can recur if unrecognized. A 56-year-old woman is described who had her third episode of post-transfusion purpura 17 years after her last exposure to the inciting antigen. Clinical and immunologic features are reviewed, and specific preventive measures are proposed.
Characterization of an outward K+ current in freshly dispersed cerebral arterial muscle cells.

This study was carried out to define some of the cellular ionic mechanisms controlling cerebral arterial muscle. Muscle cells were enzymatically dispersed from cat cerebral arteries. Cells were dialyzed and voltage-clamped using patch pipettes and whole-cell currents measured. Using pipette solutions allowing us to record K+ currents we identified an outward current elicited by depolarizing voltage steps beyond −20 mV. This outward current exhibited properties of delayed outward rectification having a peak macroscopic current at +90 mV of 504±236 pA. The current was sensitive to 4-aminopyridine, but was sensitive to tetraethylammonium only at very high doses. When CsCl was in the recording pipette, macroscopic outward currents could not be recorded. Variations in the extracellular Ca2+ concentration from 0.5 to 5.0 mM had no effect on current amplitude or voltage dependence; similarly the Ca2+ channel blockers nifedipine and Mn2+ were without effect on this outward current. The current inactivated slowly with no decay seen even with 3-s command pulses. Repetitive voltage pulses from −60 to +90 mV at a frequency of 1 Hz resulted in “cumulative reduction”, depressing peak current by 60% after ten pulses. Upon reduction of pH from 7.43 to 7.20 we observed a 350% increase in peak outward current in 7 of 12 cells studied in this regard. Thus, the cellular mechanism responsible for cerebral vascular dilation to acidosis and/or hypercapnia may involve an increase in outward K+ current.
Narrow hybrid zone between two subspecies of big sagebrush, Artemisia tridentata (Asteraceae). III. Developmental instability

Stable hybrid zones are believed to occur because gene dispersal is opposed by selection, but the nature of this selection remains unclear. The dynamic equilibrium model postulates that hybridization disrupts coadapted gene complexes, leading to alterations in development and subsequent hybrid unfitness. Alternatively, the bounded hybrid superiority model assumes that selection is due to exogenous factors. Here, we examine the developmental instability of sagebrush across a narrow hybrid zone. The results show no difference among the parental and hybrid taxa for the majority of comparisons examined. When significant differences in developmental instability were observed, one of the parental taxa (mountain big sagebrush) was typically the least developmentally stable. Hybrids were found to be the least developmentally stable for only two of the 28 comparisons studied. Interestingly, for some comparisons, hybrids were the most developmentally stable. These results contradict predictions of the dynamic equilibrium model. The sagebrush hybrid zone does not appear to be maintained by endogenous selection, as there is little indication that development is disrupted by hybridization.
The use of a controlled wireless testbed in courses

Wireless networking has become a popular topic in both undergraduate and graduate courses. However, putting together good assignments in wireless networking is difficult because the behavior of the wireless network depends strongly on the physical environment. We have used a wireless networking testbed based on signal propagation emulation in a number of wireless networking courses. The wireless emulator supports highly realistic experiments, while also offering a high degree of control and repeatability. This combination is very useful in a teaching context. In this paper we give an overview of the wireless emulator and we describe how it was used to support assignments and open-ended projects in several courses.
Distribution and morphology of large submarine sediment slides and slumps on Atlantic continental margins

Abstract Numerous large sediment slides and slumps have been discovered and surveyed on the continental margins of Northwest Africa, Southwest Africa, Brazil (Amazon Cone), the Mediterranean, the Gulf of Mexico, and North America over the past 10 years. The mass movements are of two primary types: (1) translational slides, and (2) rotational slumps. Translational slides are characterized by a slide scar and a downslope zone of debris flows, after traveling in some areas for several hundreds of kilometers on slopes of less than 0.5°. Rotational slumps are bounded by steep scarps, but they do not involve large‐scale translation of sediments, although seismic records indicate disturbance in the down‐dropped block. Many of the slides and slumps have occurred in water depths greater than 2000 m on initial slopes of less than 1.5°. The largest slide so far discovered is off Spanish Sahara; in this case, the slide scar is 18,000 km2 in area, at least 600 km3 in volume of translated sediments. No apparent consist...
Climate Change Bandwagoning: The Impacts of Strategic Linkages on Regime Design, Maintenance, and Death

The entree of climate change politics to the center stage of international relations has been accompanied by broad range of strategic linkages, which have produced various institutional interactions. This special issue takes stock of the wide range of ways that international regimes are strategically linked to climate change politics. We do this with a view to better understand both how climate change is shaping the global environmental political landscape, and is being shaped itself through strategic linkages to regimes both within (i.e. forests, biodiversity, fisheries, and desertification) and beyond (i.e. security and human rights) the environmental realm. The contributions that make up this special issue explore when, how, and by whom regime linkages should be pursued, how linkage politics are affecting regime development and function, and in turn how these changes are shaping the evolution of global environmental politics and problem solving writ large.
Population Health Measurement: Applying Performance Measurement Concepts in Population Health Settings

Introduction: Whether the focus of population-health improvement efforts, the measurement of health outcomes, risk factors, and interventions to improve them are central to achieving collective impact in the population health perspective. And because of the importance of a shared measurement system, appropriate measures can help to ensure the accountability of and ultimately integrate the efforts of public health, the health care delivery sector, and other public and private entities in the community to improve population health. Yet despite its importance, population health measurement efforts in the United States are poorly developed and uncoordinated. Collaborative Measurement Development: To achieve the potential of the population health perspective, public health officials, health system leaders, and others must work together to develop sets of population health measures that are suitable for different purposes yet are harmonized so that together they can help to improve a community’s health. This begins with clearly defining the purpose of a set of measures, distinguishing between outcomes for which all share responsibility and actions to improve health for which the health care sector, public health agencies, and others should be held accountable. Framework for Population Health Measurement: Depending on the purpose of the analysis, then, measurement systems should clearly specify what to measure—in particular the population served (the denominator), what the critical health dimensions are in a measurement framework, and how the measures can be used to ensure accountability. Building on a clear understanding of the purpose and dimensions of population health that must be measured, developers can then choose specific measures using existing data or developing new data sources if necessary, with established validity, reliability, and other scientific characteristics. Rather than indiscriminately choosing among the proliferating data streams, this systematic approach to measure development can yield measurement systems that are more appropriate and useful for improving population health.
Management of Patients with Decompensated HBV Cirrhosis

Patients with decompensated hepatitis B virus (HBV) cirrhosis have a poor prognosis due to the development of progressive liver failure and hepatocellular carcinoma. Lamivudine appears to be a safe and effective antiviral agent, which may improve or stabilize liver disease in selected patients with advanced cirrhosis and active HBV replication. However, viral resistance can develop with prolonged treatment and some patients with advanced cirrhosis may not experience any discernible benefit. The use of hepatitis B immunoglobulin prophylaxis with or without lamivudine has resulted in excellent survival and a low rate of graft reinfection in patients who undergo liver transplantation for decompensated HBV cirrhosis. Adefovir and entecavir are newer antiviral agents that have activity against both wild-type and lamivudine-resistant HBV. Additional studies of individual or combination antiviral agents are urgently needed to improve further the prospects for the large number of patients worldwide with decompensated HBV cirrhosis.
Recognition of Authors in Blind Review of Manuscripts

Some scientists claim that blind review is rarely possible. Since referees of journal articles are supposed to be experts in a particular field, they are expected to know all about the current work being carried out by important investigators. The results of this study show that the major source of information tipping off the identity of authors is the manuscript itself, not the expert knowledge of referees. Almost all referees who guessed the identity of an author felt capable of setting the information aside when judging the manuscript.
Use of continuous culture for internal pH determination of lactic acid bacteria

Abstract The response of cytoplasmic pH to external cellular pH was shown to be influenced by the growth phase forLeuconostoc mesenteroides, but not forLactobacillus plantarum. A continuous culture system was shown to reduce growth phase effects, and offer the advantage of more consistency in internal pH values. Oxygen, manganese, cell density, external pH, and organic acid production were shown not to influence the internal pH of these bacteria when grown in continuous culture.
Integrating nanowires with substrates using directed assembly and nanoscale soldering

This paper describes a new methodology for integrating nanowires with micropatterned substrates using directed assembly and nanoscale soldering. Nanowires containing ferromagnetic nickel segments were fabricated by electrodeposition in nanoporous membranes. The nanowires were released by dissolution of the membrane and subsequently aligned relative to micropatterned substrates using magnetic field-directed assembly. After assembly, the wires were permanently bonded to the substrates using solder reflow to form low-resistance electrical contacts. This is the first demonstration of the use of nanoscale solder reflow to form low-resistance electrical interconnects between nanowires and substrates, and we demonstrated the utility of the strategy by fabricating a nanowire-based functional analog integrator.
Structural and Functional Impact of Amino Acid Substitution on Calmodulin Binding in Cardiac Myocytes

Calmodulin (CALM) is an important protein involved in numerous signaling processes, acting through induced conformational changes in response to local calcium concentration. In the cardiac myocyte, CALM binds to several important components involved in excitation, in particular L-type Calcium Channels (LTCC), Cardiac Ryanodine Receptors (RYR2), and Calcium/Calmodulin-dependent protein Kinase II (CaMKII). CALM plays a role in LTCC and RYR2 channel dynamics through direct binding interactions and through CaMKII-dependent phosphorylation. Recent studies into the impact of specific single nucleotide polymorphisms (SNPs) in CALM have been linked to specific changes in the behavior of LTCC's and RyR2's and also to various cardiac disease states (e.g. Long QT Syndrome and Catecholaminergic Polymorphic Ventricular Tachycardia). In addition, additional CALM SNPs have been observed in publicly available genomic databases based upon genomic sequencing of the general human population and these SNPs that have not yet been functionally classified. Using a computational mutagenesis approach based on Delaunay tessellation and statistical geometry, the impact of specific SNPs on the structural stability of CALM-binding interactions has been predicted. These predictions indicate the likelihood that a specific SNP mutation alters CALM structure and thereby its function. Results indicate certain SNP mutations have a differential impact on CALM binding stability to its various targets. Deeper analysis of CALM structure suggests the possible underlying mechanism by which these mutations can cause cardiac disease and may explain why certain mutations correlate with a particular disease state.
Polymer multilayers loaded with antifungal β-peptides kill planktonic Candida albicans and reduce formation of fungal biofilms on the surfaces of flexible catheter tubes

Candida albicans is the most common fungal pathogen responsible for hospital-acquired infections. Most C. albicans infections are associated with the implantation of medical devices that act as points of entry for the pathogen and as substrates for the growth of fungal biofilms that are notoriously difficult to eliminate by systemic administration of conventional antifungal agents. In this study, we report a fill-and-purge approach to the layer-by-layer fabrication of biocompatible, nanoscale 'polyelectrolyte multilayers' (PEMs) on the luminal surfaces of flexible catheters, and an investigation of this platform for the localized, intraluminal release of a cationic β-peptide-based antifungal agent. We demonstrate that polyethylene catheter tubes with luminal surfaces coated with multilayers ~700nm thick fabricated from poly-l-glutamic acid (PGA) and poly-l-lysine (PLL) can be loaded, post-fabrication, by infusion with β-peptide, and that this approach promotes extended intraluminal release of this agent (over ~4months) when incubated in physiological media. The β-peptide remained potent against intraluminal inoculation of the catheters with C. albicans and substantially reduced the formation of C. albicans biofilms on the inner surfaces of film-coated catheters. Finally, we report that these β-peptide-loaded coatings exhibit antifungal activity under conditions that simulate intermittent catheter use and microbial challenge for at least three weeks. We conclude that β-peptide-loaded PEMs offer a novel and promising approach to kill C. albicans and prevent fungal biofilm formation on surfaces, with the potential to substantially reduce the incidence of device-associated infections in indwelling catheters. β-Peptides comprise a promising new class of antifungal agents that could help address problems associated with the use of conventional antifungal agents. The versatility of the layer-by-layer approach used here thus suggests additional opportunities to exploit these new agents in other biomedical and personal care applications in which fungal infections are endemic.