cssi/SciSciGPT-SciSciNet huggingface dataset:
The Average-Case Complexity of Counting Cliques in Erdős-Rényi Hypergraphs

The complexity of clique problems on Erdős-Renyi random graphs has become a central topic in average-case complexity. Algorithmic phase transitions in these problems have been shown to have broad connections ranging from mixing of Markov chains and statistical physics to information-computation gaps in high-dimensional statistics. We consider the problem of counting k-cliques in s-uniform Erdős-Renyi hypergraphs G(n, c, s) with edge density c and show that its fine-grained average-case complexity can be based on its worst-case complexity. We prove the following: •Dense Erdős-Renyi hypergraphs: Counting k-cliques on G(n, c, s) with k and c constant matches its worst-case complexity up to a polylog(n) factor. Assuming ETH, it takes n^Ω(k) time to count k-cliques in G(n, c, s) if k and c are constant. • Sparse Erdős-Renyi hypergraphs: When c = Θ(n^-α), for each fixed α our reduction yields different average-case phase diagrams depicting a tradeoff between runtime and k. Assuming the best known worst-case algorithms are optimal, in the graph case of s = 2, we establish that the exponent in n of the optimal running time for k-clique counting in G(n, c, s) is ωk/3 - C α (k/2) + O_k, α (1), where ω/9 ≤ C ≤ 1 and ω is the matrix multiplication constant. In the hypergraph case of s ≥ 3, we show a lower bound at the exponent of k - α (k/s) + O_k, α (1) which surprisingly is tight against algorithmic achievability exactly for the set of c above the Erdős-Renyi k-clique percolation threshold. Our reduction yields the first known average-case hardness result on Erdos-Renyi hypergraphs based on a worst-case hardness assumption. We also analyze several natural algorithms for counting k-cliques in G(n, c, s) that establish our upper bounds in the sparse case c = Θ(n^-α).
Evidentialism and belief polarization

Belief polarization occurs when subjects who disagree about some matter of fact are exposed to a mixed body of evidence that bears on that dispute. While we might expect mutual exposure to common evidence to mitigate disagreement, since the evidence available to subjects comes to consist increasingly of items they have in common, this is not what happens. The subjects’ initial disagreement becomes more pronounced because each person increases confidence in her antecedent belief. Kelly (2008a) aims to identify the mechanisms that underlie this phenomenon and assess whether these processes undermine the justification of polarized beliefs. He concludes that given evidentialism, justification is not undermined by the polarizing mechanisms. I take on board Kelly’s description of the polarizing mechanisms, but challenge his conclusion. I argue that on plausible versions of evidentialism, the beliefs that result from these routes to polarization are not justified.
10 – Climate Dynamics

Publisher Summary The term “climate” refers to the mean state of the atmosphere and related components of the Earth system and is also used in reference to atmospheric variability on timescales longer than the 2- to 3-week limit of most deterministic atmospheric predictability. The distinction between climate variability and climate change is largely semantic: if the variations of interest take place within some specified interval, they are referred to as the variability of the climate within that interval, whereas if the variations involve differences between two successive epochs, they are referred to as the “change in climate from one epoch to the next.” This chapter describes the present-day climate and the processes that shape it. The chapter discusses the nature and causes of climate variability on various timescales and relates it to the history of past climate. The chapter also discusses the climate sensitivity and climate feedbacks. It concludes by summarizing some of the scientific issues related to greenhouse warming.
In situ friction and wear behavior of rubber materials incorporating various fillers and/or a plasticizer in high-pressure hydrogen

Abstract Polymers are used routinely for equipment and infrastructure in hydrogen vehicle refueling stations, but significant gaps remain in understanding their hydrogen compatibility. The tribological properties of these materials in a high-pressure hydrogen environment is important in preventing component failure and the need for frequent replacement. We present in situ tribological studies on model rubbers, which include common fillers and plasticizer, using an in situ tribometer developed previously. Results suggest a clear, yet complicated, combined effect of the high-pressure hydrogen and the additives on the tribological performance of the chosen materials, as compared to matching experiments performed in ambient air. We find that the additives improved wear resistance in EPDM but deteriorated that in NBR due to disparate additive-polymer interactions.
Gender Differences Among Milestone Assessments in a National Sample of Pediatric Emergency Medicine Fellowship Programs

Background Understanding gender gaps in trainee evaluations is critical because these may ultimately determine the duration of training. Currently, no studies describe the influence of gender on the evaluation of pediatric emergency medicine (PEM) fellows. Objective The objective of our study was to compare milestone scores of female versus male PEM fellows. Methods This is a multicenter retrospective cohort study of a national sample of PEM fellows from July 2014 to June 2018. Accreditation Council for Medical Education (ACGME) subcompetencies are scored on a 5-point scale and span six domains: patient care (PC), medical knowledge, systems-based practice, practice-based learning and improvement, professionalism, and interpersonal and communication skills (ICS). Summative assessments of the 23 PEM subcompetencies are assigned by each program's clinical competency committee and submitted semiannually for each fellow. Program directors voluntarily provided deidentified ACGME milestone reports. Demographics including sex, program region, and type of residency were collected. Descriptive analysis of milestones was performed for each year of fellowship. Multivariate analyses evaluated the difference in scores by sex for each of the subcompetencies. Results Forty-eight geographically diverse programs participated, yielding data for 639 fellows (66% of all PEM fellows nationally); sex was recorded for 604 fellows, of whom 67% were female. When comparing the mean milestone scores in each of the six domains, there were no differences by sex in any year of training. When comparing scores within each of the 23 subcompetencies and correcting the significance level for comparison of multiple milestones, the scores for PC3 and ICS2 were significantly, albeit not meaningfully, higher for females. Conclusion In a national sample of PEM fellows, we found no major differences in milestone scores between females and males.
Corrosion behavior of boronized nickel-based alloys in the molten chloride Salt

Abstract The study investigates the effects of diffusion coating by boronization on the corrosion behavior of IN718 and C276 in molten KCl-MgCl2-NaCl salt at 800 °C. The boride layer was uniform and non-porous comprising of an outermost (nickel-silicide and metal-borides) layer, the middle "compound" (metal-borides), and inner "dispersed" or "diffusion" layer (intermixture of metal-borides). Both the boronized alloys exhibited better corrosion resistance. The average mass-loss (mg/cm2) was in the increasing order of boronized C276
The Effect of Image Resolution on Automated Classification of Chest X-rays

Deep learning models have received much attention lately for their ability to achieve expert-level performance on the accurate automated analysis of chest X-rays. Although publicly available chest X-ray datasets include high resolution images, most models are trained on reduced size images due to limitations on GPU memory and training time. As compute capability continues to advance, it will become feasible to train large convolutional neural networks on high-resolution images. To verify that this will lead to increased performance, we perform a systematic evaluation to measure the effect of input chest X-ray image resolution on accuracy. This study is based on the publicly available MIMIC-CXR-JPG dataset, comprising 377,110 high resolution chest X-ray images, and provided with 14 labels to the corresponding free-text radiology reports. Our original hypothesis that increased resolution would lead to higher accuracy held true for some but not all of the tasks. We find, interestingly, that tasks that require a large receptive field are better suited to downscaled input images, and we verify this qualitatively by inspecting effective receptive fields and class activation maps of trained models. Finally, we show that stacking an ensemble across resolutions outperforms each individual learner at all input resolutions while providing interpretable scale weights, suggesting that multi-scale features are crucially important to information extraction from high-resolution chest X-rays.
Re-examining chemically defined liquid diets through the lens of the microbiome

Trends in nutritional science are rapidly shifting as information regarding the value of eating unprocessed foods and its salutary effect on the human microbiome emerge. Unravelling the evolution and ecology by which humans have harboured a microbiome that participates in every facet of health and disease is daunting. Most strikingly, the host habitat has sought out naturally occurring foodstuff that can fulfil its own metabolic needs and also the needs of its microbiota, each of which remain inexorably connected to one another. With the introduction of modern medicine and complexities of critical care, came the assumption that the best way to feed a critically ill patient is by delivering fibre-free chemically defined sterile liquid foods (that is, total enteral nutrition). In this Perspective, we uncover the potential flaws in this assumption and discuss how emerging technology in microbiome sciences might inform the best method of feeding malnourished and critically ill patients. Humans and their microbiota are intrinsically linked. Owing to dynamic interactions within the gut, nutritional science needs to incorporate the microbiome. This Perspective re-examines the history, rationale and future prospects of chemically defined diets (enteral or parenteral) in relation to the burgeoning understanding of the human microbiota.
The mRNA-LNP platform's lipid nanoparticle component used in preclinical vaccine studies is highly inflammatory.

SUMMARY Vaccines based on mRNA-containing lipid nanoparticles (LNPs) are a promising new platform used by two leading vaccines against COVID-19. Clinical trials and ongoing vaccinations present with varying degrees of protection levels and side effects. However, the drivers of the reported side effects remain poorly defined. Here we present evidence that Acuitas’ LNPs used in preclinical nucleoside-modified mRNA vaccine studies are highly inflammatory in mice. Intradermal and intramuscular injection of these LNPs led to rapid and robust inflammatory responses, characterized by massive neutrophil infiltration, activation of diverse inflammatory pathways, and production of various inflammatory cytokines and chemokines. The same dose of LNP delivered intranasally led to similar inflammatory responses in the lung and resulted in a high mortality rate, with mechanism unresolved. Thus, the mRNA-LNP platforms’ potency in supporting the induction of adaptive immune responses and the observed side effects may stem from the LNP’s highly inflammatory nature.
Software Receiver Design: Build your Own Digital Communication System in Five Easy Steps

Have you ever wanted to know how modern digital communications systems work? Find out with this step-by-step guide to building a complete digital radio that includes every element of a typical, real-world communication system. Chapter by chapter, you will create a MATLAB realization of the various pieces of the system, exploring the key ideas along the way, as well as analyzing and assessing the performance of each component. Then, in the final chapters, you will discover how all the parts fit together and interact as you build the complete receiver. In addition to coverage of crucial issues, such as timing, carrier recovery and equalization, the text contains over 400 practical exercises, providing invaluable preparation for industry, where wireless communications and software radio are becoming increasingly important. A variety of extra resources are also provided online, including lecture slides and a solutions manual for instructors.
Observations on the Making of a Police Officer

Like most graduate students, I entered the Ph.D. program pretty clueless. Because I love cities, I wanted to study something urban related. In sociology, that generally means race, education, or immigration. I’m not certain exactly when I started thinking about police as an academic field, but something odd was happening in 1995, my first year of sociology graduate school at Harvard. Crime was plummeting, and nobody knew why.
Theoretical modeling and analysis of the emission spectra of a ChemCam standard: Basalt BIR-1A

Abstract We report on efforts to perform theoretical modeling of the emission spectrum measured from a basalt sample. We compare our calculations with measurements that were made to provide standards for the ChemCam instrument on the Mars Science Laboratory. We find that to obtain good agreement between modeling and the measurement, it is necessary to determine atomic and ionic level populations via a multi-element approach in which the free electron density that is created influences all the species within the plasma. Calculations that consider each element separately are found to be in poorer agreement with the measured spectrum, indicating that the ‘matrix effect’ term often used to describe the influence of other species on the emission spectrum from a given element is due to the influence of the global electron density of the plasma. We explore the emission features in both the visible and near-infrared wavelength ranges, and also examine radiation transport effects for some of the most intense features found in the basalt spectrum. Finally, we also provide comparisons of the ChemCam measurement with new high-resolution spectral measurements.
Purification and properties of the elastase from Aspergillus fumigatus.

Elastase, a potential virulence factor from the opportunistic pathogen Aspergillus fumigatus, was purified 220-fold from culture broth by fast-performance liquid chromatography employing anion exchange (Q Sepharose fast flow), cation exchange (S Sepharose fast flow), and gel filtration (Superose 12). Purified to near homogeneity, the elastase had an apparent molecular mass of 32 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (silver stain) but a mass of about 19.1 kDa as determined by gel filtration on Superdex 75. The elastase is not glycosylated and is positively charged at neutral pH, having a pI of 8.75. Inhibition by 0.2 mM phenylmethylsulfonyl fluoride (100%) and 0.21 mM leupeptin (60%) implies that the elastase is a serine protease. However, the enzyme is also inhibited by 5 mM EDTA (100%) and 10 mM 1,10-orthophenanthroline (30%), suggesting a requirement for divalent cations. The enzyme acts optimally at pH 7.4 and 45 degrees C in 50 mM sodium borate buffer, but in Tris HCl, the pH optimum shifts to 8.8. Images
The problem of coincidences

This paper deals with the origin, history and various appearances of the problem of coincidences (matches, rencontres) in the theory of probability.
The Syntax of Early English.

The Syntax of Early English Olga Fischer. Ans van Kemenade, Willem Koopman, and Wim van der Wurff. Cambridge: Cambridge University Press, 2000 xviii. 341 pp.
Cranial nerve pathology in multiple system atrophy (MSA): Implications for the in vivo evaluation of disease (P1.271)

OBJECTIVE: To assess alpha-synuclein (AS) pathology at the entry (Redlich-Obersteiner) zone of the glossopharyngeal/vagus nerves (CNs IX/X) in MSA, Parkinson disease (PD) and Lewy body disease (LBD), as well as AS deposition in olfactory bulb and tract (OB/CN I) and the optic pathway in MSA. BACKGROUND: Patients with PD and LBD may have AS lesions in extra-CNS tissues and OB/CN I, offering potential for in vivo biopsy confirmation of disease. Involvement of cranial nerves in MSA is less well known. DESIGN/METHODS: AS-immunoreactive lesions across the entry zone of CNs IX/X were evaluated in pathologically confirmed autopsied patients, including 16 with MSA (median age 67 years) and 9 with PD or LBD (median age 82 years). OB/CN I involvement was evaluated in 6 MSA patients (median age 63 years). Glial cytoplasmic inclusions (GCIs) were assessed in the optic chiasm and tract of 18 MSA patients (median age 67 years). RESULTS: Seven of 9 PD/LBD cases (77.8[percnt]) showed AS lesions at the CN IX/X entry zone, typically as multiple strongly immunoreactive axons; this was not seen in MSA (Fisher exact p = 0.00002). In contrast, MSA patients demonstrated AS pathology in the OB/CN I as GCIs (100[percnt]), neuronal inclusions (83.3[percnt]) and LB-like inclusions and neurites (33.3[percnt]). GCIs in optic pathway were frequent in MSA (88.9[percnt]), ranging from 1-9 GCIs per 10x microscopic field, and GCI density was independent of disease duration. CONCLUSIONS: The entry zone of CNs IX/X lacks AS pathology in MSA, suggesting that extra-CNS tissues subserved by these peripheral nerves would not harbor diagnostic AS lesions on premortem biopsy. MSA patients have pathologic involvement of OB/CN I, including LB-like inclusions and neurites. Further, GCIs are present in the optic pathway of many MSA patients suggesting the possibility of AS deposition in the retinal ganglion cell layer. Disclosure: Dr. Cykowski has nothing to disclose. Dr. Coon has nothing to disclose. Dr. Low has received personal compensation for activities with Chelsea Therapeutics, Pfizer Inc., and WR Medical Electronics Company as a consultant. Dr. Benarroch has received personal compensation in an editorial capacity for Neurology. Dr. Powell has nothing to disclose. Dr. Parisi has nothing to disclose.
Beyond Preemption: The Federal Law and Policy of Intellectual Property Licensing

Proposed Uniform Commercial Code article 2B, which will govern transactions in information, will remake the law of intellectual property licensing in a radical way. But federal and state intellectual property policies impose significant limits on the ability of states to change these rules by contract law. One such limit is preemption, but preemption is unlikely to provide sufficient protection for the established rules of intellectual property law. Three other sets of doctrines will limit the ability of parties to set their terms by contract, even in the UCC 2B world. The first doctrine is copyright misuse, which has been applied against restrictive licensing provisions. The second set of doctrines provides that a number of licensing rules are decided as questions of federal, not state, law. The third doctrines are state public policies that cannot be overriden by contract. Taken together, these doctrines create a patchwork federal policy of intellectual property law that UCC 2B cannot alter.
Installation of Site‐Specific Methylation into Histones Using Methyl Lysine Analogs

Chromatin structure is influenced by post-translational modifications on histones, the principal basic protein component of chromatin. In order to study one of these modifications, lysine methylation, in the context of reconstituted chromatin, this unit describes the installation of analogs of methyl lysine residues into recombinant histones. The modification site is specified by mutating the lysine of interest to cysteine. The mutant histones are expressed and purified, and the cysteine residue alkylated to produce N-methyl aminoethylcysteine, an isosteric analog of methyl lysine. Using different alkylating reagents, it is possible to install analogs of mono-, di-, or trimethyl lysine. While these analogs are not identical to methyl lysine residues, they show similar biochemical properties to their natural counterparts. The ease of synthesis of methyl lysine analog (MLA) histones, especially on a large scale, makes them particularly useful reagents for studying the effects of histone lysine methylation on chromatin structure, biophysics and biochemistry.
Curricula and State of the Profession

The business simulation provides an interesting opportunity for incorporating quantitative methods and techniques into marketing management courses. The simulation model can be used to generate a realistic data bank of information on the costs and results of the firm's marketing efforts. Rather than beginning without a history of company operations and results, the simulation becomes an ongoing one where student managers employ data from past simulated operations as inputs to quantitative analyses to support current decisions. Meaningful data is provided in a context that encourages student learning and discovery of the benefits and limitations of decision science techniques.
Characterization of Organic Soil Nitrogen in a Hutton Series Soil from the Kwazulu‐Natal Midlands

Abstract The labile soil organic nitrogen pool and the effect of old kraal manure on the pools of labile organic N in a Hutton series soil from Cedara in the Midlands of KwaZulu‐Natal in South Africa were determined. Four levels of kraal manure (0, 5, 10, and 15 t ha−1 oven dry basis) were applied in the field in a randomized complete block design with three replicates. Total soil N, microbial biomass N, and anaerobic mineralizable N were determined on soil samples taken a month after manure application. All three pools of soil organic N showed significant (p 10 t ha−1. Considering the work involved in measuring each pool and the variability among replicates it was apparent that anaerobic mineralizable N was the best pool for monitoring small changes in soil fertility. In addition, approximately 13% of the total soil organic N in the soil studied was potentially avai...
Relationship between DNA repair and cell recovery: importance of competing biochemical and metabolic processes.

The relationship between the inhibition of repair of radiation-induced DNA damage and the inhibition of recovery from radiation-induced potentially lethal damage (PLD) by hypertonic treatment was compared in 9L/Ro rat brain tumor cells. Fed plateau phase cultures wereγ-irradiated with 1500 rad and then immediately treated for 20 min with a 37° C isotonic (0.15 M) or hypertonic (0.50 M) salt solution. The kinetics of repair of radiation-induced DNA damage as assayed using alkaline filter elution were compared to those of recovery from radiation-induced PLD as assayed by colony formation. Hypertonic treatment of unirradiated cells produced neither DNA damage nor cell kill. Post-irradiation hypertonic treatment inhibited both DNA repair and PLD recovery, while post-irradiation isotonic treatment inhibited neither phenomenon. However, by 2 h after irradiation, the amount of DNA damage remaining after a 20 min hypertonic treatment was equivalent to that remaining after a 20 min isotonic treatment. In contrast, cell survival after hypertonic treatment remained 2 logs lower than after isotonic treatment even at times up to 24 h. These results suggest that the repair of radiation-induced DNA damageper se is not causally related to recovery from radiation-induced PLD. However, the data are consistent with the time of DNA repair as an important parameter in determining cell survival and, therefore, tend to support the hypothesis that imbalances in sets of competing biochemical or metabolic processes determine survival rather than the presence of a single class of unrepaired DNA lesions.
INTERNAL-EXTERNAL CONTROL AND BLACK COLLEGE STUDENTS' ATTRIBUTIONS OF CAUSALITY FOR OWN AND OTHERS' PERFORMANCE

Forty-three black college students, classified as internal of external on Rotter's I-E Scale, were presented hypothetical situations in which their and a black male's semester grade point average was an A. Thereafter subjects made attributions of causality for their own and others' performance. Internal attributions (ability or effort) for own and others' school performance were more frequently made by subjects who were external on the ideological dimension of control (belief in the general role that society plays in controlling outcomes) and internal on the personal dimension of control (belief in own competence in controlling outcomes). Conversely a greater proportion of external attributions (luck or difficulty of task) for own and others' school performance were made by subjects who were internal on the ideological dimension but external on the personal level of control. Internality on both levels of control yielded more internal attributions. Externality on both dimensions of control resulted in more...
A Semiempirical Transition State Structure for the First Step in the Alkaline Hydrolysis of Cocaine. Comparison between the Transition State Structure, the Phosphonate Monoester Transition State Analog, and a Newly Designed Thiophosphonate Transition State Analog

Semiempirical molecular orbital calculations have been performed for the first step in the alkaline hydrolysis of the neutral benzoylester of cocaine. Successes, failures, and limitations of these calculations are reviewed. A PM3 calculated transition state structure is compared with the PM3 calculated structure for the hapten used to induce catalytic antibodies for the hydrolysis of cocaine. Implications of these calculations for the computer–aided design of transition state analogs for the induction of catalytic antibodies are discussed.
A virus DNA gate: Zipping and unzipping the packed viral genome

Tailed bacterial viruses (bacteriophages) are ubiquitously distributed in nature and are likely the most abundant organisms on the biosphere (1). Spending most of their time outside of the host, a bacterial cell, in often hostile external environments, they come to “life” upon encountering the receptor molecules on the host cell surface. The virus consists of a head (capsid) into which the DNA (genome) is packaged and a tail that delivers the genome into the bacterium. The capsid is pressurized because of packing of highly negatively-charged, relatively rigid dsDNA to near-crystalline density (≈500 μg/mL). The internal capsid pressure, ≈6 MPa or >10 times that of bottled champagne (2), provides a driving force for delivery of viral genome into host cell. One of the longstanding questions in phage biology has been how these viruses contain the DNA pressure and trigger release only upon recognition of a specific host cell. In this issue of PNAS, a study by Lhuillier et al. (3) describes the pseudoatomic structure of a DNA gate from the Bacillus subtilis bacteriophage SPP1, which “zips” the capsid after the genome is packaged and unzips it when the virus is ready to infect the host. It is a compelling story, which began with the first in vitro virus assembly experiments described by Edgar and Wood >40 years ago (4) and is applicable not only to phages but also to large eukaryotic viruses such as herpes viruses.
Abstract LB-495: Myeloid-derived suppressor cells promote cancer-associated fibroblast migration and carcinoma cell invasion

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Metastasis the most devastating part of cancer, yet we know very little about the earliest steps of metastasis. Myeloid-Derived Suppressor Cells (MDSC) are CD11b+, Gr-1+ bone marrow-derived cells that have been shown to promote tumor development by suppressing T cells. In addition to immune suppression, MDSC can promote metastasis. MDSC localize to the invasive edges of primary tumors and promote breast cancer lung metastasis. Localized invasion of cancer cells is the earliest step of metastasis and fibroblasts are required for breast cancer cell invasion. Fibroblasts remodel the ECM and leave tracks for collective migration of carcinoma cells. These studies seek to identify the mechanism of MDSC promotion of metastasis by determining if MDSC can stimulate fibroblast migration and lead localized carcinoma invasion. Freshly isolated MDSC from a mammary tumor-bearing mouse increase fibroblast migration. TGFβRII-/- fibroblasts demonstrate a further increase in migration in response to MDSC, suggesting that TGFβ signaling is not required for MDSC promotion of fibroblast migration. MDSC secretions act directly on fibroblasts since conditioned medium from MDSC increases fibroblast migration to the same extent as live MDSC. Antibody array analysis identified several MDSC secreted proteins, including CXCL11, CXCL15, FGF2, IGF-I, IL-4 and Shh. MDSC increase carcinoma cell invasion through Matrigel, but only when fibroblasts are present. MDSC treatment of fibroblasts stimulates Akt and ERK1/2 phosphorylation and loss of secreted proteins, including SDF-1, TIMP-1, TNFα and VEGF. Analysis of subsets of MDSC identified that monocytic MDSC (CD11b+, Ly6Chi, Ly6G-) increase fibroblast migration more than other myeloid cell populations. Tumor-derived MDSC promote fibroblast migration more that splenic MDSC. These studies show that MDSC can lead fibroblasts to stimulate carcinoma invasion and suggest that perivascular MDSC may be the earliest stimulus for localized invasion during metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-495. doi:1538-7445.AM2012-LB-495
Search for ultraviolet shuttle glow

In January 1986, the Space Shuttle Columbia carried two ultraviolet experiments (UVX) in an attempt to observe very weak diffuse emission from various astronomical sources at wavelengths below 3200 A with moderate spectral resolution. The experiment attested to the feasibility of low cost astronomy from the Space Shuttle using Get Away Special canisters. Emissions from O2, O, and NO were detected and shown to be consistent with an atmospheric origin.
Chunking by a pigeon in a serial learning task.

A basic principle of human memory is that lists that can be organized into memorable 'chunks' are easier to remember. Memory span is limited to a roughly constant number of chunks and is to a large extent independent of the amount of information contained in each chunk1,2. Depending on the ingenuity of the code used to integrate discrete items into chunks, one can substantially increase the number of items that can be recalled correctly. Newly developed paradigms3 for studying memory in non-verbal organisms allow comparison of the abilities of human and non-human subjects to memorise lists. Here I present two types of evidence that pigeons 'chunk' 5-element lists whose components (colours and achromatic geometric forms) are clustered into distinct groups. Those lists were learned twice as rapidly as a homogeneous list of colours or heterogeneous lists in which the elements are not clustered. The pigeons were also tested for knowledge of the order of two elements drawn from the 5-eIement lists. They responded in the correct order only to those subsets that contained a chunk boundary. Thus chunking can be studied profitably in animal subjects; the cognitive processes that allow an organism to form chunks do not presuppose linguistic competence.
The responses of African American women firefighters to gender harassment at work

The purpose of the present study is to describe the responses of African American women firefighters to sexual and gender harassment. Surveys and interviews of 22 firefighters nationwide uncovered universal exposure to harassment. Contrary to prior studies, most of which involved white college students and white collar workers, all these firefighters used externally focused, direct response strategies. Nineteen women directly confronted the harasser; of these, ten responded aggressively, including four women who countered physical harassment in kind. Their stories suggested that most found their strategy to be effective at stopping the present harassment and deterring future occurrences. While few firefighters reported positive work relations, these may have been a precursor to, rather than a result of, their direct response patterns.
Cross sections for ionization of water vapor by 7-4000-keV protons.

Cross sections for production of electrons and positive ions by proton impact on water vapor have been measured from 7\char21{}4000 keV by the transverse-field method.
A New Approach for Computing Pressure Derivative in Well Test Analysis

Abstract Analysts commonly use the pressure derivative to identify flow regimes and well test interpretation models in pressure-transient test analysis. This article developed a novel adaptive smoothing algorithm by recursive differentiation–integration to improve the pressure derivative calculation. Our method can efficiently suppress measurement errors and produce smooth pressure derivatives from well test data. Equally important, it can prevent oversmoothing of the data by avoiding inappropriate use of large window size, and it can preserve the characteristic behavior of the pressure derivative. We validate our approach with a synthetic case and demonstrate its applicability to actual field examples.
The harmonic vibration models in centerless grinding

Abstract Several studies on the work-rounding mechanism in centerless grinding have been made so far. But how the harmonic of the spectrum of the roundness profile of the workpiece is generated in centerless grinding is not detailed. In this paper the harmonic vibration models are established corresponding to the spectrum analysis of the roundness profile. Based on the magnification factor of vibration equations why the amplitudes of the 2nd and 3rd harmonics are always greater in the spectra of the roundness profiles is explained. Then the instantaneously unstable characters of the harmonic vibration models are introduced. Finally the principles of the distribution of the local maximum harmonics in the spectrum are given.
Fragmentation and cultural landscapes: tightening the relationship between human beings and the environment

Abstract Fragmentation is a research concept properly belonging to the biosciences and agriculture, yet it is one finding application in the planning and design fields. Cultural landscapes, on the other hand, is a concept uniquely rooted in landscape architecture and resource management. This paper links the two as a means of better grounding each in the decisions and processes affecting countryside planning and rural landuse, although both concepts have applications in urban settings, as well. However, in theory and in practice, both concepts are impacted by the man versus nature paradigm, in which planners and designers are challenged to consider whether human actions are “natural” actions, or whether they belong in a separate philosophical category. This position paper was developed as a keynote speech for the 2000 ISOMUL Conference at the Wageningen University and Research Center in The Netherlands.
Ballistic conductance calculation of atomic-scale nanowires of Au and Co

Ballistic conductance calculations on infinite one-atom zigzag chains of Co and Au, and multi-atom Au nanowires, were computed using the Landauer?B?ttiker formalism within the local-density approximation (LDA). In the cobalt case, the majority spin channel exhibits quantized conductance, but because of the close spacing of the d levels, the minority channel does not. The calculated conductance is somewhat larger than what is observed. We suggest that the discrepancy is an indication that the Landauer?B?ttiker formalism breaks down in this narrow d band material. In contrast, Au (which was determined not to be spin polarized) does show well-behaved quantization in the case of the infinite zigzag chain. By increasing the dimension of the cross section of the chain, we find that quantization is lost once the lateral dimensions of the wire exceed two or so atoms. Finally, we show that the zigzag chain of Au can have a Peierls instability, making the chain insulating.
The influence of methanol on the interactions of calcium with the pyridine nucleotides.

Abstract The interactions of calcium with NAD + , NADH, NADP + and NADPH in a 50% (by volume) methanol/water mixture (pH 7, 25°C) were studied by calorimetry. The association constants for 1:1 complex formation were found to be 6.6±0.2, 270±76, 18±3 and 98±10 for NAD + , NADH, NADP + and NADPH, respectively. Comparing these to the association constants for an aqueous system reveals that as the polarity of the solvent system is decreased the interactions involving NAD + , NADP + and NADPH are all decreased. In contrast, the interaction involving NADH is markedly increased. All the interactions were found to be endothermic.
Correlation and toxicological inference of trace elements in tissues from stranded and free-ranging bottlenose dolphins (Tursiops truncatus)

Abstract The significance of metal concentrations in marine mammals is not well understood and relating concentrations between stranded and free-ranging populations has been difficult. In order to predict liver concentrations in free-ranging dolphins, we examined concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, total Hg (THg), V, Zn) in skin and liver of stranded bottlenose dolphins (Tursiops truncatus) from the South Carolina (SC) coast and the Indian River Lagoon, Florida (FL) during 2000–2008. Significantly higher concentrations of Zn, Fe, Se, Al, Cu and THg were found in skin while liver exhibited significantly higher Cu, Fe, Mn and THg concentrations for both study sites. Mean skin concentrations of Cu and Mn were significantly higher in SC dolphins while higher concentrations of THg and V were found in FL dolphins. In addition, liver tissues in SC dolphins exhibited significantly higher As concentrations while higher Fe, Pb, Se, THg, and V levels were found in FL dolphins. Two elements (Cu and THg) showed significant age-related correlations with skin concentration while five elements (Cu, Se, THg, Zn and V) showed age-related correlations with liver concentrations. Geographic location influenced age-related accumulation of several trace elements and age-related accumulation of THg in hepatic tissue was observed for both sites to have the highest correlations (r2 = 0.90SC; r2 = 0.69FL). Mean THg concentration in liver was about 10 times higher in FL dolphins (330 μg g−1 dw) than those samples from SC dolphins (34.3 μg g−1 dw). The mean molar ratio of Hg to Se was 0.93 ± 0.32 and 1.08 ± 0.38 for SC and FL dolphins, respectively. However, the Hg:Se ratio varied with age as much lower ratios (0.2–0.4) were found in younger animals. Of the 18 measured elements, only THg was significantly correlated in skin and liver of stranded dolphins and skin of free-ranging dolphins from both sites suggesting that skin may be useful in predicting Hg concentrations in liver tissue of free-ranging dolphins. Results indicate that 33% of the stranded and 15% of the free-ranging dolphins from FL exceed the minimum 100 μg g−1 wet weight (ww) (∼400 dw) Hg threshold for hepatic damage while none from SC reached this level. Hepatic concentrations of As in SC dolphins and V in FL dolphins were also highly correlated with skin concentrations which may have some regional specificity predictive value. The present study provides the first application of trace element concentrations derived from stranded bottlenose dolphins to predict liver concentrations in free-ranging populations.
Clinical and cytogenetic features of familial erythroleukaemia.

Summary. A family is described in which six members developed acute nonlymphocytic leukaemia (ANLL) over the past 1 5 years, all morphologically FAB M6. Five affected individuals (ages 54-73) are members of a single sibship, the sixth (age 31) was the son of one of the affected sibs. The family lives in a rural area, and no environmental hazard has been identified. One of the six patients never resided in the same geographic area as the others. Three patients with leukaemia died without chemotherapy, two died shortly after the initiation of chemotherapy and the most recent patient never achieved remission, surviving 10 months. Bone marrow specimens from the two most recent patients were analysed for cytogenetic abnormalities using chromosome banding techniques. In addition, skin fibroblasts were examined in a single patient. The fibroblasts had a normal karyotype. Bone marrow cells from both patients had complex abnormalities. Some similarities were observed, including: (1) hypodiploidy; (2) loss of one chromosome 20; (3) the presence of multiple marker chromosomes. In each case one marker appeared to involve the‘missing’no. 20 with an alteration of the long arm—loss (20q —) in one patient and gain (20q +) in the other. Peripheral blood lymphocytes were grown in folate deficient medium, but no evidence for folate sensitive fragile sites was found. Marrow chromosomes from a third leukaemic sibling were examined without banding techniques in 1976 and the karyotype was 45.XY, — 18, — F(19 or 20), -I-marker. No specific cytogenetic finding was common to the three patients studied except for the loss of an F group chromosome. This family is unique in the literature with six cases of familial leukaemia of the same morphologic subtype, and the cytogenetic findings suggest that loss or rearrangement of part of the long arm of a single chromosome 20 may have occurred in each of the three patients examined.
Volume assessment of the normal female cervix with MR imaging: Comparison of the segmentation technique and two geometric formulas

Rationale and Objectives. The purpose of this study was to determine the volume of the normal female cervix and to determine the geometric formula that yields the best estimate. Materials and Methods. Magnetic resonance images of the pelvis in 30 young women were reviewed retrospectively. The volume of the cervix was estimated by using the formulas for an ellipse and a cylinder. Manual labeling and segmentation of the cervix were also performed, and the volume was calculated on the basis of the number and size of the voxels. Comparison of these methods was then performed by using a two-tailed Student t test. Results. No statistically significant difference was found ( P = .7) between the volume calculated with the segmentation technique (25.3 mL) and that estimated with the formula for a cylinder (24.8 mL). A statistically significant difference ( P Conclusion. The normal volume of the cervix in this population of young women was approximately 25 mL. The volume of the cervix should be estimated with the formula for a cylinder.
Implications of a selective acknowledgment scheme on satellite performance

Data link response time is becoming more of a concern today with the onset of satellite transmissions of computer data. The long propagation delay inherent to satellite communications may lead to a degradation in data link response time as compared to the same transmission over purely terrestrial links. Furthermore, data link errors need be considered in any such study of response time of satellite data links. A model has been developed to study data link response time under a selective acknowledgment retransmission protocol. The model not only calculates mean link response time, but also the second moment of the response time. This model is then applied to various interactive data transmission schemes over a half-duplex (HDX) satellite link with terrestrial tails, although modifications can easily be made to analyze pure terrestrial or satellite links. The model parameters include bit error rate (BER), terrestrial as well as satellite propagation delay, modem transit delay, MAXOUT (maximum number of unacknowledged data frames), frame size (bits), and message size (bits).
α-Conotoxin BuIA, a Novel Peptide from Conus bullatus, Distinguishes among Neuronal Nicotinic Acetylcholine Receptors

Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels. α Subunits, together with β2 and/or β4 subunits, form ligand-binding sites at α/β subunit interfaces. Predatory marine snails of the genus Conus are a rich source of nAChR-targeted peptides. Using conserved features of the α-conotoxin signal sequence and 3′-untranslated sequence region, we have cloned a novel gene from the fish-eating snail, Conus bullatus; the gene codes for a previously unreported α-conotoxin with unusual 4/4 spacing of amino acids in the two disulfide loops. Chemical synthesis of the predicted mature toxin was performed. The resulting peptide, α-conotoxin BuIA, was tested on cloned nAChRs expressed in Xenopus oocytes. The peptide potently blocks numerous rat nAChR subtypes, with highest potency for α3- and chimeric α6-containing nAChRs; BuIA blocks α6/α3β2 nAChRs with a 40,000-fold lower IC50 than α4β2 nAChRs. The kinetics of toxin unblock are dependent on the β subunit. nAChRs with a β4 subunit have very slow off-times, compared with the corresponding β2 subunit-containing nAChR. In each instance, rat αxβ4 may be distinguished from rat αxβ2 by the large difference in time to recover from toxin block. Similar results are obtained when comparing mouse α3β2 to mouse α3β4, and human α3β2 to human α3β4, indicating that the β subunit dependence extends across species. Thus, α-conotoxin BuIA also represents a novel probe for distinguishing between β2- and β4-containing nAChRs.
Determination modified enthalpy of formation of straight alkyl-chained carboxylic acids and esters

Abstract A test set of 35 straight alkyl-chained carboxylic acids and esters was examined to elucidate theoretically their enthalpies of formation by performing density-functional theory (DFT) and ab initio calculations. The calculated error for the straight structure monotonically increases with the number of methylene groups in the main alkyl chain. All calculated data were modified using a three-parameter calibration equation and the least-squares approach, to determine accurate enthalpies of formation (ΔHf). This work studied that the atomization energies of all compounds exhibited an average absolute relative error of 0.03%, and a ΔHf with a mean absolute error (M.|AE|) of just 3.1 kJ/mol (0.7 kcal/mol), according to DFT calculations.
Clinical and Neurobiological Aspects of Narcolepsy

Abstract Narcolepsy is characterized by excessive daytime sleepiness (EDS), cataplexy and/or other dissociated manifestations of rapid eye movement (REM) sleep (hypnagogic hallucinations and sleep paralysis). Narcolepsy is currently treated with amphetamine-like central nervous system (CNS) stimulants (for EDS) and antidepressants (for cataplexy). Some other classes of compounds such as modafinil (a non-amphetamine wake-promoting compound for EDS) and γ-hydroxybutyrate (GHB, a short-acting sedative for EDS/fragmented nighttime sleep and cataplexy) given at night are also employed. The major pathophysiology of human narcolepsy has been recently elucidated based on the discovery of narcolepsy genes in animals. Using forward (i.e., positional cloning in canine narcolepsy) and reverse (i.e., mouse gene knockout) genetics, the genes involved in the pathogenesis of narcolepsy (hypocretin/orexin ligand and its receptor) in animals have been identified. Hypocretins/orexins are novel hypothalamic neuropeptides also involved in various hypothalamic functions such as energy homeostasis and neuroendocrine functions. Mutations in hypocretin-related genes are rare in humans, but hypocretin-ligand deficiency is found in many narcolepsy–cataplexy cases. In this review, the clinical, pathophysiological and pharmacological aspects of narcolepsy are discussed.