cssi/SciSciGPT-SciSciNet huggingface dataset:
Fusion activity of HIV gp41 fusion domain is related to its secondary structure and depth of membrane insertion in a cholesterol-dependent fashion.

Abstract The human immunodeficiency virus (HIV) gp41 fusion domain plays a critical role in membrane fusion during viral entry. A thorough understanding of the relationship between the structure and the activity of the fusion domain in different lipid environments helps to formulate mechanistic models on how it might function in mediating membrane fusion. The secondary structure of the fusion domain in small liposomes composed of different lipid mixtures was investigated by circular dichroism spectroscopy. The fusion domain formed an α-helix in membranes containing less than 30 mol% cholesterol and formed β-sheet secondary structure in membranes containing ≥ 30 mol% cholesterol. EPR spectra of spin-labeled fusion domains also indicated different conformations in membranes with and without cholesterol. Power saturation EPR data were further used to determine the orientation and depth of α-helical fusion domains in lipid bilayers. Fusion and membrane perturbation activities of the gp41 fusion domain were measured by lipid mixing and contents leakage. The fusion domain fused membranes in both its helical form and its β-sheet form. High cholesterol, which induced β-sheets, promoted fusion; however, acidic lipids, which promoted relatively deep membrane insertion as an α-helix, also induced fusion. The results indicate that the structure of the HIV gp41 fusion domain is plastic and depends critically on the lipid environment. Provided that their membrane insertion is deep, α-helical and β-sheet conformations contribute to membrane fusion.
Palmitoylation Plays a Role in Targeting Vac8p to Specific Membrane Subdomains

Vac8p is a multifunctional yeast protein involved in several distinct vacuolar events including vacuole inheritance, vacuole homotypic fusion, nucleus-vacuole junction formation and the cytoplasm to vacuole protein targeting pathway. Vac8p associates with the vacuole membrane via myristoylation and palmitoylation. Vac8p has three putative palmitoylation sites, at Cys 4, 5 and 7. Here, we show that each of these cysteines may serve as a palmitoylation site. Palmitoylation at Cys 7 alone provides partial function of Vac8p, whereas palmitoylation at either Cys 4 or Cys 5 alone is sufficient for Vac8p function. In the former mutant, there is a severe defect in the localization of Vac8p to the vacuole membrane, while in the latter mutants, there is a partial defect in the localization of Vac8p. In addition, our studies provide evidence that palmitoylation targets Vac8p to specific membrane subdomains.
The Changing Geoepidemiology of Food Allergies

The science of food allergy has been rapidly evolving before our eyes in the past half century. Like other allergic disorders, the prevalence of food allergies has dramatically increased, and coupled with the increased public awareness of anaphylaxis due to food allergy, this has driven an explosion in basic and clinical research in this extremely broad subject. Treatment of food allergies has evolved and practices such as food challenges have become an integral part of an allergy practice. The impact of the increase of food allergy has driven package labeling laws, legislation on emergency treatment availability in schools and other public places, and school policy. But to this day, our knowledge of the pathogenesis of food allergy is still incomplete. There are the most obvious IgE-mediated immediate hypersensitivity reactions, but then multiple previously unidentified conditions such as eosinophilic esophagitis, food protein-induced enterocolitis syndrome, milk protein allergy, food-induced atopic dermatitis, oral allergy syndrome, and others have complicated the diagnosis and management of many of our patients who are unable to tolerate certain foods. Many of these conditions are not IgE-mediated, but may be T cell-driven diseases. The role of T regulatory cells and immune tolerance and the newly discovered immunological role of vitamin D have shed light on the variable clinical presentation of food allergy and the development of new methods of immunotherapy in an example of bench-to-bedside research. Component-resolved diagnostic techniques have already begun to allow us to more precisely define the epitopes that are targeted in food allergic patients. The development of biological modulators, research on genomics and proteomics, and epigenetic techniques all offer promising avenues for new modes of therapy of food allergy in the twenty-first century.
Retention/Promotion Decisions: Selective Use of Data?

Summary.-The ucility of using psychomenic data to facilitate decisions about retention/promotion for 58 kindergarten and first-grade children was investigated. Analyses suggested that members of decision-making teams may use data selectively and that recommendations to retain or promote may be subject to bias. Teachers of children in kindergarten and primary grades, as well as other educational professionals (e.g., principals, consultants, school psychologists), frequently face decisions about retention and promotion. These decisions may be especially difficult because research on this topic is equivocal. For example, in a comprehensive review, Jackson (1975) concluded that neither the beneficial nor the detrimental effects of retention on academic performance and social/emotional adjustment had been clearly demonstrated. In contrast, others (Lieberman, 1980; Light, 1977) suggested that research results have been obscured by the heterogeneous nature of samples. The major irnplication is that particular subgroups of young children may benefit from retention rather than promotion. Ic is important for teachers and other educational professionals to base such decisions on data associated with the best predictive accuraq. The purpose of this study was to investigate the utiliry of several sources of data for the facilitation of decisions on retention and promotion. Three hypotheses were formulated: (1) Aptitude: Because children with substantially above-average or below-average learning aptitudes are less likely to benefit from retention (Light, 1977), a psychometric measure of learning aptitude (conceptual rcaturity) was predicted to discriminate children referred for consideration of retencion and actually retained from those eventually promoted. (2) Prereading Skills: Given the emphasis on phonetic approaches to reading instruction within the school district in which the study was conducted, it was predicted that among referred kindergarteners psychometric measures of prereading phonics skills would discriminace berween the two groups. (3) Readiness: It was predicted that among referred kindergarteners psychometric measures of general readiness for first grade would discriminate those actually retained from those eventually promoted.
FLUORESCENCE OF PYRENYL AND CARBAZOLYL DERIVATIVES IN LIQUID SOLUTION AND SOLID FILM

A systematic investigation of the effects of stereochemistry and solid-state morphology on emission characteristics were performed using glass-forming pyrenyl and carbazolyl derivatives as neat films in PMMA and cholesteric liquid crystalline glass. At high dilution in tetrahydrofuran, pyrenyl derivatives were prone to form intramolecular excimers whereas carbazolyl derivatives showed no evidence for excimers. Both pyrenyl and carbazolyl derivatives at 10-3 to 10-2 M in isotropic and ordered solid hosts exhibited mostly monomer emission. In neat films, intermolecular excimers prevailed in pyrenyl derivatives whereas carbazolyl derivatives showed evidence for monomer emission as well. One feature that distinguishes carbazolyl derivatives from poly(N-vinylcarbazole) is the observed fine structures in the fluorescence spectra of thin films. Order parameters characterizing the helical alignment of pyrenyl and carbazolyl pendants with a cholesteric host were determined with circularly polarized fluorescence sp...
The biopolitics of needle exchange in the United States.

Needle exchange began in the United States as a fragmented and illegal practice initiated by actors at the grassroots level; since the late 1980s, needle exchange has achieved increasing yet variable levels of institutional support across the country, receiving official sanction and funding from state and municipal governments. In turn, the practice(s) and discourse(s) of needle exchange have shifted significantly in many locales, becoming the purview of professional administration that advocates needle exchange as a necessary public health measure. This article is interested in the ways in which needle exchange has become implicated in and appropriated by networks of power seeking to discipline and regulate injection drug use. Drawing theoretically on Michel Foucault's writings concerning biopower and governmentality, it will examine the proliferation of discourses, knowledges, and rules surrounding needle exchange in the United States. At the same time, this article will avoid a characterization of need...
The RNA world: Approaches to the prebiotic synthesis of RNA

It has been proposed that the main biopolymers in the first life on earth was composed of RNA and that the protein-DNA world evolved from it. The concept of the RNA world is based on the observations that RNA can store information and can catalyze chemical reactions. In vitro evolution studies have demonstrated that RNA can catalyze a number of chemical reactions. It remains to be demonstrated that RNA can be formed from monomers that may have been present on the the primitive earth and that these RNAs possess catalytic activity. Experimental studies directed towards the prebiotic synthesis of RNA will be described. Plausible and not so plausible steps in the currently proposed prebiotic pathways will be identified.1 Possible steps in the process will be presented including the formation of pyrimidine and purine bases and ribose or ribose analogs. Experiments describing the formation of nucleotides will then be outlined followed by approaches to the activation of their phosphate groupings. Progress made in the mineral-catalyzed polymerization of activated nucleotides will be outlined. Speculation will be presented suggesting how these polymers may have initiated the RNA world.
The carboxyl-terminal tridecapeptide of platelet factor 4 is a potent chemotactic agent for monocytes.

Abstract The carboxyl-terminal tridecapeptide of platelet factor 4, Pro-Leu-Tyr-Lys-Lys-Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser, was synthesized and found to have chemotactic activity towards monocytes at concentrations 1 30 that of the parent molecule, while eliciting the migration of cells comparable in number to that seen using the parent and the control C5a. In an α-helical conformation the tridecapeptide would be amphiphilic, making it a good candidate for binding to membrane surfaces. Indeed, addition of sodium dodecyl sulfate, an amphiphile, induces an increase in the peptide's α-helicity, as shown by the circular dichroism spectrum. Pro-Leu-Tyr methyl ester was found to be inactive, indicating that the N-terminal region is not the recognition site of the tridecapeptide. These results suggest that the tridecapeptide incorporates the active site of human platelet factor 4 for monocyte chemotaxis.
Recovery of contrast sensitivity during optic nerve regeneration in fish

Psychophysical experiments on goldfish and sunfish studied the recovery time course of visual contrast detection during optic nerve regeneration. The results showed delayed recovery of detection of positive as compared to negative contrasts, and of high as compared to low spatial frequencies. The findings are related to previous electrophysiological and anatomical results in the fish retinotectal system.
Atypical atrial tachycardias in patients with congenital heart disease

a c i c o d a p p a c f w ohn. Patients with congenital heart disease (CHD) have a high revalence of atrial tachycardia, particularly after they have ndergone reparative or palliative surgical procedures. These rrhythmias are predominantly, although not exclusively, he clinical expression of macroreentrant circuits that are imilar in many ways to atrial flutter. Anatomical factors romoting macroreentry include the idiosyncrasies of the nderlying cardiac anatomy and the effects of surgical inervention, resulting in anatomical barriers to impulse propgation. More subtle changes in the electrophysiological roperties of the atrial myocardium itself are also implicated y the pathological observation of myocellular hypertrophy nd fibrosis, the frequent co-occurrence of sinus node dysunction, the recording of a diffusely low amplitude of endoardial electrograms in arrhythmia mapping studies, and the pidemiological observation that time—often decades—is a articularly significant risk factor for development of such achycardias. The analysis of surgical models of atrial arrhythmia and he subsequent application of various mapping technologies o this patient group has revealed the particular importance f cardiac anatomy in the development and propagation of trial reentrant circuits. Mirroring observations made in dults without CHD, the single most common form of atrial achycardia among patients with CHD appears to be isthus-dependent atrial flutter, particularly in patients with impler anatomical lesions (e.g., tetralogy of Fallot, atrial nd ventricular septal defects). In these patients, the essenial anatomical relations of the four-chambered heart are reserved, and factors such as an atriotomy or atrial fibrosis nd hypertrophy serve as promoters for early development f the typical form of atrial flutter. In complex CHD paients, however, that isthmus may occur in dextrocardia, on he pulmonary venous side of an intra-atrial baffle, or beween the inferior vena cava and the right-sided mitral valve n the case of ventricular inversion—or all three simultaeously! Additionally, the occurrence of a variety of more
Cardiovascular Pharmacology of N,N′-Bis-[α-(2-pyridyl)ethyl]-ethylenediamine Dimaleate

N , N ′-Bis-[ α - (2-pyridyl)ethyl]-ethylenediamine dimaleate (JB 5058), a substituted polymethylene diamine with hypotensive action, was noted to have alpha adrenergic blocking activity, as demonstrated in the cat superior cervical ganglion nictitating membrane preparation. It did not produce a centrally mediated hypotensive response in the dog cross-circulation preparation. JB 5058 produced only a transient decrease in cardiac output while increasing femoral blood flow. The hypotensive activity of JB 5058 appears to be caused by a decrease in peripheral vascular resistance primarily due to alpha adrenergic blockade. It also appears to produce a modest antagonism of angiotensin II on vascular smooth muscle.
Nine new species of Licaria (Lauraceae) from tropical America

Abstract. Nine species of the neotropical genus Licaria from South America, Panama, and Costa Rica are described and illustrated. The new species are Licaria agglomerata, L. clarensis, L. cogolloi, L. colombiana, L. comata, L. deltoidea, L. nitida, L. sclerophylla, and L. terminalis. Their relationships within the genus are discussed.
NEUROID TRANSMISSION IN CILIATED EPITHELIUM

Evidence from several sources indicates that there is present in certain types of ciliated tissue a primitive form of conduction regulating the rate of beat of the cilia. (Kraft, 1890; Engelmann, 1898). A similar type of conduction has been observed by Parker (1910) in the sponge Stylotella. In the foregoing experiments a study was made of such conduction in the ciliated tissue of the gills of the clam Unio. Observations were made on the effects of temperature changes on the rate of beat of cilia adjacent to areas not themselves directly influenced. The following results were obtained. 1. The transmission through the gill of the effects of warmth applied locally is apparent through increased rate of ciliary beat on adjacent gill tissue in all directions from the region of application. Effects are not observed laterally at a distance greater than 9 to 11 mm. from the nearest edge of the stimulated area. The narrowness of the gill makes it impossible to determine the vertical limits of the transmission. 2. Effects of low temperatures are not observable beyond the limits of the region of direct application. These results differ from those of Kraft in tissue from the frog's pharynx, where conduction was shown to take place only down a row of beating cilia. On the other hand they agree with his results in indicating that the effects of warmth only are transmitted. The phenomenon might be explained by the stimulating effect of the action current of the directly excited cilia on the neighboring relatively quiet cilia. A similar explanation has been offered by Lillie for waves of coordinated beating in the rows of swimming plates of ctenophores. Such an explanation, though in accord with the work on Unio, is inconsistent with certain of the observations of Kraft on the tissue from the frog's pharynx.
Laryngotracheal reconstruction with resorbable microplate buttressing.

Objectives/Hypothesis: In patients undergoing laryngotracheal reconstruction (LTR), malacic segments of trachea can pose challenges to successful reconstruction. Malacic segments may inadequately support cartilage grafts used in augmentation surgery, sometimes requiring cricotracheal or tracheal resections. We describe a novel technique of LTR with resorbable microplate buttressing of malacic lateral tracheal segments. Study Design: Retrospective case series. Methods: Review of technique, treatment outcomes, and complications of seven children with subglottic stenosis and tracheomalacia requiring a microplate-augmented LTR technique. Results: Seven infants ranging from 26 months to 9 years of age successfully underwent LTR for subglottic stenosis. Six children had a grade III subglottic stenosis. The seventh child had grade II subglottic stenosis, bilateral vocal fold paralysis, an elliptical cricoid, and an obstructing giant suprastomal fibroma. Five children underwent a double-stage LTR with resorbable microplates sutured bilaterally to support severely malacic lateral tracheal segments. A cricotracheal resection would not have been feasible in one child due to the resection length and inadequate tracheal mobilization. Two children underwent a single-stage LTR with unilateral application of a microplate. Six children were decannulated within 3 months and continue without airway symptoms or complications. One child, who is just over 2 months from reconstructive surgery, is being setup for decannulation. No complications were encountered. Conclusions: LTR with resorbable microplate buttressing of malacic lateral tracheal segments is technically feasible, safe, and can avoid more extensive surgery requiring tracheal resection. Further experience may support the use of this technique in challenging airway reconstructions. Laryngoscope, 2012
The action of phospholipase C and lipase on black film bilayer membranes.

Abstract Phospholipase C(C. perfringens) added to one side of a phosphatidyl choline—phosphatidyl serine—cholesterol (0.7: 0.3: 1.0, w/w/w) bilayer membrane resulted in a rapid decrease in membrane resistance which leveled off after several minutes at about one-half its initial value. Pancreatic lipase added at this time resulted in a rapid increase in membrane resistance to a value somewhat higher than the initial. This effect was independent of the side to which the lipase was added, indicating that diglyceride is rapidly equilibrated across both sides of the membrane. When both phospholipase C and lipase were added at zero time to the same or opposite sides, the resistance decreased slightly and then increased to a value higher than the initial. Replacement of phosphatidyl choline by 2-hexadecoxy-3-octadecoxypropyl-phosphonylcholine, a phosphonate analog, resulted in an inhibition of the phospholipase C reaction which was equal to the percent analog. The analog, thus, seemed to act only as inert lipid and did not inhibit hydrolys of the active lipid.
The magnetic field of complex partial seizures agrees with intracranial localizations

The magnetoencephalogram (MEG) was recorded during 63 complex partial seizures in 4 patients. The MEG showed large biomagnetic signals occurring at the same time as discharges recorded from scalp electroencephalogram (EEG). These MEG signals had the same morphology and frequency as the discharges from the EEG. The location of the seizure focus was verified by depth electrode recordings in 2 patients and by lesions shown on computed tomographic scan and magnetic resonance imaging in the other 2. In each patient, MEG localization estimates were consistent with the location of the seizure focus shown by other methods. When seizures were recorded repeatedly and mapped with a single-channel magnetometer placed at different scalp locations in a single patient, the MEG localization agreed with the electrographic seizure focus localized from depth electrodes. In the maps, the MEG resolved an ambiguity in the scalp EEG and therefore increased the confidence of localization. MEG recordings of seizures may help localize epileptic foci noninvasively.
BPrevention of Cutaneous Tissue Contracture During Removal of Craniofacial Implant Superstructures for CT and MRI Studies.

Head and neck cancer patients who have lost facial parts following surgical intervention frequently require craniofacial implant retained facial prostheses for restoration. Many craniofacial implant patients require computed tomography and magnetic resonance imaging scans as part of their long-term follow-up care. Consequently removal of implant superstructures and peri-abutment tissue management is required for those studies. The purpose of the present paper was to describe a method for eliminating cranial imaging artifacts in patients with craniofacial implants.
Abstract B38: Unveiling the mechanisms of melanoma metastasis using a chick embryo neural crest model system

In an attempt to elucidate the mechanisms of melanoma metastasis, our laboratory has recently performed a molecular comparison between melanoma and the embryonic neural crest. The neural crest is a multi-potent and highly invasive cell population, and represents the ancestral cell type of melanocytes. We report that melanoma cells exploit portions of the embryonic neural crest development program to facilitate invasion. In particular, Eph receptor tyrosine kinases and their cognate ligands, the ephrins, are dynamically regulated by C8161 melanoma cells to facilitate migration. We noted that the purported metastasis suppressor EphB6 was significantly reduced in invasive melanoma cells compared to poorly invasive melanoma cells and primary human melanocytes. In the current study, we have utilized the chick embryo transplant model system to examine the effects of EphB6 re-expression in C8161 melanoma cells. EphB6 over-expression significantly alters cell directionality of migrating melanoma cells within the embryo. We confirmed the anti-metastatic effect of EphB6 in melanoma cells using a chick CAM metastasis assay, which demonstrated a significant decrease in metastatic potential. Importantly, tumor formation appeared unaffected. These results suggest that EphB6 acts specifically as a metastasis suppressor, likely at the metastatic step of intravasation. Our studies also demonstrate the chick embryo as a powerful tool with which to compare and dissect the complex mechanisms of metastasis in vivo that are similar or distinct from normal developmental processes. Citation Format: Caleb M. Bailey, Paul M. Kulesa. Unveiling the mechanisms of melanoma metastasis using a chick embryo neural crest model system. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B38.
Diagnostic Procedures for Isolation and Characterization of Clostridium Difficile Associated with Enterocolitis in Foals

Microbiological examination of diarrheic feces is frequently an unproductive exercise for diagnostic laboratories. The low yield of positive results can be caused by poor specimen selection and quality, the need for specialized detection methods for various microorganisms, or the inability to detect and recognize unknown pathogens. Consequently, the cau foal diarrhea remains unknown. se of many cases of
Production of new antigens in phage-infected Escherichia coli K12 (λ)

Abstract Antisera prepared against crude extracts and fractions of Escherichia coli K12 (λ) infected with phage T4 have been completely absorbed with extracts of uninfected K12 (λ). These sera no longer give a positive precipitin reaction or agar diffusion test with extracts of uninfected bacteria, but they still react weakly with intact T4 phage and strongly with both disrupted phage and extracts of T4-infected K bacteria. However, these absorbed antisera, after absorption with intact and disrupted phage particles, exhibit positive precipitin and agar diffusion tests only with extracts of infected bacteria. These results suggest that the residual activity in the serum absorbed with extracts of uninfected bacteria and of phage is due to antibodies produced against new antigens, which are present in the infected cell but are not found in purified phage particles.
Delayed-choice quantum cryptography

Quantum cryptography is a method of communicating securely, the secrecy of which is guaranteed by the laws of physics and information theory. Current implementations suffer from relatively short ranges and low data rates. We are developing a system that modifies the usual protocol by incorporating elements of special relativity. The result is that in principle, every detected photon can be used in the final key, thus doubling or tripling the possible data rate. Our delayed-choice quantum cryptography (DCQC) system works by storing the photon sent to Bob in a low-loss optical delay line until a classical signal from Alice informs him which measurement basis to use.
Magnetic properties of oceanic pillow basalts from Macquarie Island

WE summarise here the results of a combined palaeomagnetic, hysteresis, thermomagnetic, and electron microprobe analysis of late Tertiary oceanic pillow basalts from Macquarie Island, which indicate that pillow basalts from a significant depth in the oceanic lithosphere have suffered burial metamorphism during the crustal accretion process. This metamorphism results in an intensity of natural remanent magnetisation (NRM) of ∼10−3 gauss, a substantial component of viscous remanent magnetisation (VRM), and an order of magnitude decrease in the Koenigsberger ratio relative to unaltered pillow basalts. Since a pillow lava layer with such a low NRM intensity is insufficient to account for the observed amplitude of marine magnetic anomalies, we conclude that in the case of Macquarie Island the underlying basaltic and doleritic dyke complex must also contribute to the observed anomalies.
Solution processing of composite fibers containing rodlike and thermoplastic polymers

The solution processing and mechanical properties made from blends of the rodlike polymer poly(p-phenylene benzobisthiazole) with either poly(ether ether ketone) or nylon 6,6 is described. The concentration dependence of the isotropic-nematic phase transition for solutions of these polymers in methane sulfonic acid is in qualitative agreement with a theory of Flory. The mechanical properties of fibers that were wet spun from isotropic solutions of poly(ether ether ketone) and poly(p-phenylene benzobisthiazole) are very sensitive to the concentration of the spinning solution. Fibers spun at concentrations near the isotropic-nematic phase boundary have poor mechanical properties, resulting from phase separation during coagulation. However, when the solution concentration is significantly below the critical value, stiff and strong fibers are produced. In contrast, when nylon 6,6 is used as the thermoplastic component, the mechanical properties are good and are insensitive to the solution concentration. We attribute the solution concentration effects to two factors. The first is the difference in the solubility of poly(ether ether ketone) and nylon 6,6 in methane sulfonic acid-water mixtures. The second is the connectivity of the nematic phase, which also depends on concentration and has a major impact on the mechanical properties of the resulting fiber.
Susceptibility of intact germinating Arabidopsis thaliana to human fungal pathogens Cryptococcus neoformans and C. gattii.

ABSTRACT The fungus Cryptococcus contributes a large global burden of infectious death in both HIV-infected and healthy individuals. As Cryptococcus is an opportunistic pathogen, much of the evolutionary pressure shaping virulence occurs in environments in contact with plants and soil. The present studies investigated inoculation of intact seeds of the common weed Arabidopsis thaliana with fungal cells over a 21-day period. C. gattii was the more virulent plant pathogen, resulting in disrupted germination as well as increased stem lodging, fungal burden, and plant tissue colocalization. C. neoformans was a less virulent plant pathogen but exhibited prolonged tissue residence within the cuticle and vascular spaces. Arabidopsis mutants of the PRN1 gene, which is involved in abiotic and biotic signaling affecting phenylalanine-derived flavonoids, showed altered susceptibility to cryptoccocal infections, suggesting roles for this pathway in cryptococcal defense. The fungal virulence factor laccase was also implicated in plant pathogenesis, as a cryptococcal lac1Δ strain was less virulent than wild-type fungi and was unable to colonize seedlings. In conclusion, these studies expand knowledge concerning the ecological niche of Cryptococcus by demonstrating the pathogenic capacity of the anamorphic form of cryptococcal cells against healthy seedlings under physiologically relevant conditions. In addition, an important role of laccase in plant as well as human virulence may suggest mechanisms for laccase retention and optimization during evolution of this fungal pathogen.
Theoretical study of the nitrogen‐atom hyperfine coupling constant. II

The N hyperfine coupling constant has been computed using multireference configuration interaction (MRCI) and averaged coupled pair functional (ACPF) treatments in very large one‐particle basis sets. Unlike previous calculations, no selection of configurations has been performed. The calculations again illustrate the difficulty of computing the N hyperfine coupling constant accurately. The best MRCI result of 10.7 MHz is larger than the accurate experimental value of 10.4509 MHz, while the best ACPF result (10.3 MHz) is smaller than experiment. The difference between this work and previous calculations is discussed.
A boundary perturbation method for circularly periodic plates with a core

Fundamental frequencies of vibrating circularly periodic plates with a circular core have been determined analytically. A boundary perturbation method is developed to extract the fundamental eigenvalue of the governing biharmonic boundary value problem. The method is then applied to wavy and polygonal plates with clamped and simply supported outer boundary conditions. Clamped, simply supported, and free circular cores are considered. Approximate analytical formulations of the fundamental frequency for such plates with core are obtained.
Choosing a System of Unemployment Income Support: Guidelines for Developing and Transition Countries

Mounting evidence suggests that excessive job protection reduces employment and labor market flows, hinders technological innovations, pushes workers into the informal sector, and hurts vulnerable groups by depriving them of job opportunities. Flexible labor markets stimulate job creation, investment, and growth, but they create job insecurity and displace some workers. How can the costs of such insecurity and displacements be minimized while ensuring that the labor market remains flexible? Each of the main unemployment income support systems (unemployment insurance, unemployment assistance, unemployment insurance savings accounts, severance pay, and public works) has strengths and weaknesses. Country-specific conditions, chief among them labor market and other institutions, the capacity to administer each type of system, and the size of the informal sector, determine which system is best suited to developing and transition countries.
Diaspora, cyberspace and political imagination: the Eritrean diaspora online

In this article I analyse the Eritrean diaspora and its use of cyberspace to theorize the ways transnationalism and new media are associated with the rise of new forms of community, public spheres and sites of cultural production. The struggle for national independence coincided with the rise of the Internet and the Eritrean diaspora has been actively involved in the new state. Eritreans abroad use the Internet as a transnational public sphere where they produce and debate narratives of history, culture, democracy and identity. Through the web the diaspora has mobilized demonstrators, amassed funds for war, debated the formulation of the constitution, and influenced the government of Eritrea. Through their web postings, 'Internet intellectuals' interpret national crises, rearticulate values and construct community. Thus, the Internet is not simply about information but is also an emotion-laden and creative space. More than simply refugees or struggling workers, diasporas online may invent new forms of citizenship, community and political practices. Identity is not a constant and is something that is renegotiated on (a) regular basis, be it at the individual or at the national level. This is especially prob- lematic for those of us living in the diaspora, we deal with so many identities and our existence is literally schizophrenic. We want to remain actively interested in the affairs of the homeland, at the same time we live in countries that (are) careless about our internal struggles and hence our miserable dependence on mediums like Dehai for a sense of belonging and for the illusion of home that it creates. I would even venture to say that the various cyber shoutings and negative exchanges we are accustomed to in Dehai are a necessary and unavoidable aspects of being a part of such a community.
Redesigning the data structures course with user-constructed resizable arrays

There is currently a disconnect between the way in which five of the basic data structures are taught, in a data structures course, and the way in which they are increasingly used. The five data structures are stacks, queues, strings, hash tables, and matrices. Clearly all these data structures must be initially taught without reference to resizing, because the non-resizable versions of these are all very commonly used. Most teachers of data structures, however, do not go on to teach students how to write the resizable versions themselves (as opposed to using prewritten classes). We argue that this is unfortunate, from both theoretical and practical aspects.
New constructions of divisible designs

Abstract A construction is given for a ( p 2 a ( p +1), p 2 , p 2 a +1 ( p +1), p 2 a +1 , p 2 a ( p +1)) ( p a prime) divisible difference set in the group H × Z 2 pa +1 where H is any abelian group of order p +1. This can be used to generate a symmetric semi-regular divisible design; this is a new set of parameters for λ 1 ≠0, and those are fairly rare. We also give a construction for a ( p a −1 + p a −2 +…+ p +2, p a +2 , p a ( p a + p a −1 +…+ p +1), p a ( p a −1 +…+ p +1), p a −1 ( p a +…+ p 2 +2)) divisible difference set in the group H × Z p 2 × Z a p . This is another new set of parameters, and it corresponds to a symmetric regular divisible design. For p =2, these parameters have λ 1 = λ 2 , and this corresponds to the parameters for the ordinary Menon difference sets.
Nitroxyl Activates SERCA in Cardiac Myocytes via Glutathiolation of Cysteine 674

Nitroxyl (HNO) exerts inotropic and lusitropic effects in myocardium, in part via activation of SERCA (sarcoplasmic reticulum calcium ATPase). To elucidate the molecular mechanism, adult rat ventricular myocytes were exposed to HNO derived from Angeli’s salt. HNO increased the maximal rate of thapsigargin-sensitive Ca2+ uptake mediated by SERCA in sarcoplasmic vesicles and caused reversible oxidative modification of SERCA thiols. HNO increased the S-glutathiolation of SERCA, and adenoviral overexpression of glutaredoxin-1 prevented both the HNO-stimulated oxidative modification of SERCA and its activation, as did overexpression of a mutated SERCA in which cysteine 674 was replaced with serine. Thus, HNO increases the maximal activation of SERCA via S-glutathiolation at cysteine 674.
The BKCa channel's Ca2+-binding sites, multiple sites, multiple ions.

In this issue, Zeng et al. report results from a series of elegant experiments that, among other contributions, provide new evidence in support of the hypothesis that the BKCa channel contains two types of high-affinity Ca2+-binding sites. Those that work with this channel will quickly recognize the
Johnson v. United States and the Future of the Void-for-Vagueness Doctrine

Last Term, in Johnson v. United States, the U.S. Supreme Court struck down a portion of the Armed Career Criminal Act as unconstitutionally vague. The Johnson opinion is certain to have a large impact on federal criminal defendants charged with unlawfully possessing a firearm. But it is also likely to have other important consequences. The language deemed vague in Johnson is similar or identical to language in the Federal Sentencing Guidelines and other statutes. What is more, the Johnson opinion elaborates on the void-for-vagueness doctrine in important ways. Those elaborations ought to make vagueness challenges easier to win in the future.This Commentary examines the implications of Johnson. It also briefly discusses Justice Thomas’s concurrence. Justice Thomas refused to join the majority opinion, instead opting to decide the case in Johnson’s favor on statutory construction grounds. In addition to his statutory construction analysis, Justice Thomas questioned the constitutional basis of the void-for-vagueness doctrine. Justice Thomas’s approach to the vagueness doctrine, if adopted by other members of the Court, could eviscerate the notice function of the doctrine.
Creep behavior of a polycrystalline nickel aluminide: Ni-23.5 at.% A1-0.5 at.% Hf-0.2 at.% B

The creep behavior of a poly crystalline nickel aluminide with the composition Ni-23.5 at.% Al-0.5 at. % Hf-0.2 at. % B has been measured as a function of stress, temperature, and grain size. At high stresses, of the order of 100 MPa, the strain rate is nonlinear in the stress, with a stress exponent greater than two. Below approximately 10 MPa, at 1033 K, the steady-state strain rate is almost proportional to the stress, indicating that diffusional creep is rate controlling. Calculations of expected Nabarro—Herring and Coble creep rates did not answer whether diffusive mass transport through the grains, or along the grain boundaries, is rate controlling. The grain-size dependence of the strain rate, however, indicates predominance of volume diffusion control, i.e., Nabarro—Herring creep, for our experimental conditions.
New Structure Sheds Light on Selective HIV-1 Genomic RNA Packaging

Two copies of unspliced human immunodeficiency virus (HIV)-1 genomic RNA (gRNA) are preferentially selected for packaging by the group-specific antigen (Gag) polyprotein into progeny virions as a dimer during the late stages of the viral lifecycle. Elucidating the RNA features responsible for selective recognition of the full-length gRNA in the presence of an abundance of other cellular RNAs and spliced viral RNAs remains an area of intense research. The recent nuclear magnetic resonance (NMR) structure by Keane et al. [1] expands upon previous efforts to determine the conformation of the HIV-1 RNA packaging signal. The data support a secondary structure wherein sequences that constitute the major splice donor site are sequestered through base pairing, and a tertiary structure that adopts a tandem 3-way junction motif that exposes the dimerization initiation site and unpaired guanosines for specific recognition by Gag. While it remains to be established whether this structure is conserved in the context of larger RNA constructs or in the dimer, this study serves as the basis for characterizing large RNA structures using novel NMR techniques, and as a major advance toward understanding how the HIV-1 gRNA is selectively packaged.
All Bad Things Do Not Go Together: A Comment on Echeverri-Gent

John Echeverri-Gent's ( 2009 ) fine article in this symposium makes a compelling case for a greater focus on the study of inequality by political scientists. A topic we have too often neglected, its dynamics go to the core of our disciplinary concerns and we clearly should have more to offer to its understanding. APSA is to be commended for supporting the work of the Task Force on Difference, Inequality, and Developing Societies (2008), which Echeverri-Gent led, and which, in large part, informs his article in these pages. It should generate a renewed focus by political scientists on international inequality and on the role of domestic inequality in the development process.
FUTURE HISTORIANS : THEIR QUEST FOR INFORMATION

This paper examines how history graduate students at one research university seek information and how they use the university library in their information-seeking process. The general question framing the study was whether graduate students in history demonstrate the same information-seeking behavior as established scholars. Related questions explored the use of new technologies and the reliance that history graduate students place on reference librarians and librarians in special collections.
From Central Places to Network Bases: A Transition in the U.S. Urban Hierarchy, 1900–2000

The notion of a hierarchy among cities has long been part of the theoretical tool kit of urban sociologists, geographers, and economists. Reviewing the evolution of the urban hierarchy concept, thi...
Covariant Derivatives and Geodesics

Throughout this chapter, by a manifold, we shall mean a C∞ manifold, for simplicity of language. Vector fields, forms and other objects will also be assumed to be C∞ unless otherwise specified. We let X be a manifold. We denote the R-vector space of vector fields by ΓT(X). Observe that ΓT(X) is also a module over the ring of functions \( \mathfrak{F} = \mathfrak{F}^\infty (X). \) We let π:TX →X be the natural map of the tangent bundle onto X.
Sorting Out a Sore Spot.

A 6-year-old child living in Nebraska presented with a 6-month history of a sore on the left arm. Treatment with a 10-day course of oral cephalexin was unsuccessful, and the lesion gradually increased to the size of a quarter with mild itching and tenderness. The child was afebrile throughout the course and was able to pursue normal activities. On examination, the lesion was a shallow 2 × 2 cm moist ulcer with no bleeding, minimal tenderness, and a few tiny satellite lesions surrounding the ulcer (Figure 1A). There was no associated palpable lymphadenopathy. No other skin lesions or other abnormal findings were noted in physical examination. Skin (punch) biopsies were sent to the Centers for Disease Control and Prevention (CDC) for bacterial, mycobacterial, and fungal cultures. Histological sections stained with hematoxylin-eosin showed a hyperkeratotic epidermis in 1 biopsy and an ulcerated epidermis in another. A diffuse dense mixed granulomatous dermal inflammatory infiltrate of lymphocytes, histiocytes, plasma cells, neutrophils, and multinucleated giant cells was present throughout the biopsies (Figure 1B). Inflammation extended into the epidermis. Multiple intracellular oval 2–4 μm in size organisms were identified inside macrophages (Figure 2A) on high-power light microscopy. Giemsastained touch preparations demonstrated round to oval organisms measuring 2–4 μm with a 1 μm round nucleus and a smaller bar-shaped paranuclear kinetoplast (Figure 2B). A microbe was isolated in culture.
Total synthesis of the ionophore antibiotic X-206. Studies relevant to the stereoselective synthesis of the C(17)–C(26) synthon.

Abstract A stereoselective synthesis of the keto-aidehyde 4, which embodies the structural features of the C(17)–C(26) section of the polyether X-206, is described.
Direct and indirect effects of anthropogenic bird food on population dynamics of a songbird

Anthropogenic bird foods are frequently credited with affecting avian population dynamics, but few studies have tested this assertion over broad spatial scales. Human-derived foods could directly impact population sizes or indirectly affect them by mediating the influence of another factor, such as disease. In 1994, a novel disease outbreak (mycoplasmal conjunctivitis) substantially reduced populations of the house finch (Haemorhous mexicanus) in the eastern United States, creating an opportunity to test whether bird feeding indirectly exacerbated or ameliorated the impacts of the disease. We assessed the effects of bird food availability on house finch populations using data from the National Survey on Fishing, Hunting, and Wildlife-associated Recreation and the Christmas Bird Count. House finch densities were positively related to the density of people providing food for birds prior to the spread of mycoplasmal conjunctivitis, suggesting that the availability of bird seed can limit the size of finch populations. Following the disease epidemic, house finch declines were greatest where the density of people feeding birds also fell dramatically. This pattern suggests that bird food could have a positive indirect effect on disease-related mortality. Our findings suggest that the collective actions of individual people have the potential to influence resource availability and population dynamics of wildlife in human-modified landscapes.
Perspectives on formal verification (invited talk)

I will discuss the importance, uses, and future directions of formal verification from the point of view of a mathematical foundationalist. These include issues of certainty, proof structure, and (finitary) completeness and decidability.
Significance of Wing Vibration in Male Nasonia vitripennis (Hymenoptera: Pteromalidae) during Courtship

Precopulatory behavior in male Nasonia vitripennis (Walker) while mounted on a female shows pulses of wing vibration of 435 Hz, averaging .46 s duration, with resting intervals averaging .33 s. In mating receptivity tests, absence of wings in males results in most females producing only male offspring. These results indicate that the vibration may act as a tactile stimulus to induce sexual receptivity in the female. Recordings of wing vibrations of male Pteromalus puparum (L.) mounted on a female reveal pulses of 280–400 Hz, averaging .39 s.
Quantification of Adipocytes Development in a Micro-Fluidic Reactor, Using 2-Photon Fluorescence Microscopy Imaging

Intrinsic fluorescence based redox ratio calculations are used to assess the differentiation of adipocytes that are grown in an innovative micro-fluidic reactor and they are subject to a gradient of adipogenic hormone cocktail supply.
Collagenase-labile polyurethane urea synthesis and processing into hollow fiber membranes.

As a means to stimulate wound healing, a hollow fiber membrane system might be placed within a wound bed to provide local and externally regulated controlled delivery of regenerative factors. After sufficient healing, it would be desirable to triggerably degrade these fibers as opposed to pulling them out. Accordingly, a series of enzymatically degradable thermoplastic elastomers was developed as potential hollow fiber base material. Polyurethane ureas (PUUs) were synthesized based on 1, 4-diisocyanatobutane, polycaprolactone (PCL) diol and polyethylene glycol (PEG) at different molar fractions as soft segments, and collagenase-sensitive peptide GGGLGPAGGK-NH2 as a chain extender (defined as PUU-CLxEGy-peptide, where x and y are the respective molar percents). In these polymers, PEG in the polymer backbone decreased tensile strengths and initial moduli of solvent-cast films in the wet state, while increasing water absorption. Collagenase degradation was observed at 75% relative PEG content in the soft seg...