cssi/SciSciGPT-SciSciNet huggingface dataset:
Studies of the Acetyl Coenzyme A Synthetase Reaction IV. THE REQUIREMENT FOR MONOVALENT CATIONS

Abstract The monovalent cation requirement for a highly purified acetyl coenzyme A synthetase derived from bovine heart mitochondria was investigated. When removal of stimulatory cations from the reaction components was accomplished, no catalytic activity was detected. Adding chloride salts of rubidium, ammonium, potassium, tris(hydroxymethyl)aminomethane, sodium, or lithium to a final concentration of 5 to 10 mm stimulated the over-all reaction maximally. Stimulating monovalent cations acted catalytically and all of their apparent Km values fell into a range of 1 to 3 mm. Activating monovalent cations could be separated into two groups on the basis of their kinetic behavior in the over-all reaction. Cations in the first group (Rb+, NH4+, K+) gave optimal rates of acetyl coenzyme A formation at concentrations of 10 to 200 mm, showed atypical kinetics at elevated concentrations of acetate (10 to 40 mm), but failed to show altered Km values in the presence of increasing magnesium ion concentrations (3 to 27 mm). In contrast, cations in the second group (Na+ and Li+) inhibited the reaction at concentrations greater than 10 mm, had this inhibition partially reversed by monovalent cations in the first group, did not have their kinetics effected by acetate, but did show decreasing Km values as the magnesium ion concentration was increased from 3 to 27 mm. Two different activating cations, each at a concentration of 60% of its apparent Km, produced an appreciably greater reaction rate than a single cation at twice this concentration. Yet the maximal velocity obtainable with a single species was not exceeded by various combinations of activating alkali metal ions. Activating monovalent cations were also shown to be necessary for formation of enzyme-bound acetyladenylate, either from acetate and adenosine triphosphate or from acetyl coenzyme A and adenosine monophosphate. Substrate quantities of enzyme were used to demonstrate this product of both partial reactions under equilibrium conditions. Optimal yields of acetyladenylate were obtained with 5 mm rubidium or sodium chloride. Sodium chloride at 10 mm decreased this yield, whereas rubidium ions did not. These observations suggest that activating monovalent cations participate in the catalytic mechanism of acetyl coenzyme A synthetase.
MicroRNA-513 Regulates B7-H1 Translation and Is Involved in IFN-γ-Induced B7-H1 Expression in Cholangiocytes

Biliary epithelial cells (cholangiocytes) respond to proinflammatory cytokines such as IFN-gamma and actively participate in the regulation of biliary inflammatory response in the liver. B7-H1 (also known as CD274 or PD-L1) is a member of the B7 costimulatory molecules and plays a critical immunoregulatory role in cell-mediated immune responses. In this study, we show that resting human cholangiocytes in culture express B7-H1 mRNA, but not B7-H1 protein. IFN-gamma induces B7-H1 protein expression and alters the microRNA (miRNA) expression profile in cholangiocytes. Of those IFN-gamma-down-regulated miRNAs, we identified microRNA-513 (miR-513) with complementarity to the 3'-untranslated region of B7-H1 mRNA. Targeting of the B7-H1 3'-untranslated region by miR-513 results in translational repression. Transfection of cholangiocytes with an antisense oligonucleotide to miR-513 induces B7-H1 protein expression. Additionally, transfection of miR-513 precursor decreases IFN-gamma-induced B7-H1 protein expression and consequently influences B7-H1-associated apoptotic cell death in cocultured Jurkat cells. Thus, miR-513 regulates B7-H1 translation and is involved in IFN-gamma-induced B7-H1 expression in human cholangiocytes, suggesting a role for miRNA-mediated gene silencing in the regulation of cholangiocyte response to IFN-gamma.
Stability Boundaries of the Dynamic States in Pulsating and Cellular Flames

A flat, premixed flame stabilized on a circular porous plug burner at low pressure appears as a luminous disk. As the control parameters are adjusted, methaneair and methane-oxygen mixtures produce pulsating flames that exhibit both traveling-wave and standing-wave dynamic states, and isobutane-air and propane-air flames form ordered patterns of concentric luminous rings of cells that bifurcate into dynamics states in which the cells move in collective motion. In this paper the measurement and presentation of stability boundaries are discussed for representative examples of pulsating and cellular flames.
Maintenance management systems: a human factors issue

The author discussed some issues concerning the application of human-factors analysis to the design and implementation of maintenance management systems in nuclear power stations. He suggests that applying human factors at the function and task levels is the most cost-effective way of improving the way the system works. By way of illustration, he presents a few examples of problems together with approaches to understanding the problem and implementing solutions. >
Enhancing Kepler Usability and Performance

Kepler is an attempt to bridge the gap between established, organization-backed digital libraries and groups of researchers that wish to publish their findings under their control, anytime, anywhere yet have the advantages of an OAI-compliant digital library. We describe an architecture and implementation of the Kepler system that allows an archivelet to be installed in the order of minutes by an author on a personal machine and a group server in less than an hour. The group server will harvest from all archivelets and make the union of all published papers available for search to a community. We describe how a group administrator can provide an XML schema for the metadata and how the Kepler engine will validate against them when an author publishes a paper and completes the metadata. We have demonstrated that we can surmount the technical difficulties for authors to publish as easy as to a website yet produce OAI-compliant digital libraries.
A statistical approach to threshold selection in temporal video segmentation algorithms

Almost all temporal video segmentation algorithms employ thresholds. Although the selection of thresholds considerably affects the algorithm performance a framework to choose them effectively does not exist. This paper introduces a framework for selecting statistically optimal thresholds in temporal video segmentation algorithms. Statistics for various temporal video events, such as shot boundary, zoom and pan events, are collected. Then, optimal thresholds are estimated so as to minimize a statistical cost function defined in terms of the complied statistics. Results with several real video sequences containing over 150,000 frames show improvements ranging from 5%-20% in true detection and false alarm rates.
Tamara S. Wagner, Ed. Antifeminism and the Victorian Novel: Rereading Nineteenth-Century Women Writers

Tamara S. Wagner's edited collection, Antifeminism and the Victorian Novel, attempts to complicate the positions of “antifeminist” Victorian women writers, often by locating female agency in places...
Multiuser chaos communication through polyphase spreading for overlay cognitive radio

Chaos communication systems have received strong interest due to its performance and security advantages such as robustness in multi-path fading environments, resistance to jamming, and low probability of interception. With recent advances in cognitive radio, it is highly desired to combine the security advantages of chaos communication with the flexibility of cognitive radio to create a chaos based cognitive radio communication system that improves the spectrum usage while maintaining high security features. In this paper, we propose a multi-user non-continuous orthogonal frequency division multiplexing (NC-OFDM) based chaotic communication system employing orthogonal polyphase spreading codes. Specifically, a polyphase spreading code called carrier interferometry code is layered onto the frequency domain chaotic waveform to create multi-user support. The proposed system not only maintains the capability of operating over multiple non-contiguous spectrum holes, but also offers security features by chaos sequence modulation. For comparison purposes, we develop two benchmark schemes using both NC-OFDM and chaos modulation. Simulation results show significant performance advantage of the proposed scheme than the benchmark schemes. Finally, we point out that the proposed scheme allows flexible access control for different users and groups, in broadcast, multicast and unicast services.
Selected designs: note on further research.

Additional research with the Selected Designs, a screening device for detection of cerebral dysfunction, is described. Reported results for adolescents and adults over 61 yr. of age.
CONTAGIOUS ECTHYMA IN AN ADULT DALL SHEEP (Ovis dalli dalli) IN ALASKA

One of 73 wild Dall sheep (Ovis dalli dalli) captured at Sheep Creek, Alaska, had crusty lesions on mammary glands and teats compatible with contagious ecthyma (CE). A paravaccinia virus, indistinguishable from CE virus was cultured from the crusted scabs removed from the mammary gland. This is the first report of CE in free-ranging Dall sheep.
4. Idiopathic Acquired Melanosis

Acquired melanosis is the clinical term used to describe a slowly enlarging, diffusely pigmented lesion of the conjunctiva which may also involve the lids, caruncle or cornea. The controversial histologic classifications are reviewed and suggestions made regarding useful and accurate terminology. In acquired melanosis, development of malignant melanoma may occur. Previous work indicates that the prognosis of the resulting melanoma may be assessed by histopathologic staging as is done in cutaneous melanoma. The suggested management of acquired melanosis is close observation with excisional biopsies of areas clinically suggestive of invasive melanomas. Examination of the entire biopsy by serial or staged sections is essential for accurate histopathologic diagnosis. Invasive melanomas have been conventionally treated by local excision or exenteration. Radiation therapy may be a beneficial adjunct.
Selenium retention and inhibition of cell growth in mouse mammary epithelial cell lines in vitro.

The steady state levels of growth inhibitory doses of inorganic selenium were examined in five different mammary epithelial cell lines: MOD, COMMA-D, COMMA-F, COMMA-T, and YN-4. The retention of selenium was monitored using a radioactive isotope,75Se. Growth inhibition correlated with high levels of selenium in the cell. Generally, the retention of intracellular selenium was not dependent upon cell density, cell number, net growth rate, or tumorigenicity of the mammary cell lines. One cell line, COMMA-D, exhibited an unique response wherein the amount of selenium retained was low and the growth inhibitory effects of selenium were negligible when the cells were exposed to selenium at low density. However, at high cell densities, the COMMA-D cells responded like the other four cell lines. The growth inhibitory effect of selenium was reversible; upon removal of selenium from the medium, cells start synthesizing DNA within 24h. The retention of selenium was influenced by constituents in the growth medium. In particular, cysteine, but not methionine, purines, or pyrimidines altered selenium retention and counteracted the growth inhibitory effects of selenium. These results indicated that the mammary cell lines, particulary COMMA-D and MOD are good model systems to examine the uptake, retention, localization, and function of inorganic selenium under conditions where it acts as a growth inhibitory agent.
End-of-Life Decision Making for Nursing Home Residents with Dementia

Purpose: To describe families' decision-making processes, both cognitive and affective, regarding end-of-life treatments for nursing home residents with moderately severe to very severe dementia. Design: Naturalistic inquiry provided the framework for this descriptive, qualitative study. Methods: Four focus groups were conducted in selected nursing homes, in the central part of the United States for a qualitative study. Twenty-eight family members of residents with moderately severe to severe dementia shared their decision-making experiences. Open-ended questions were asked in each focus group. Data were analyzed using content analysis. Findings: Five themes were identified that describe the context of decision making: emotional effect, insult-to-life story, two faces of death, values and goals regarding end-of-life treatments, and the unrecognized trajectory of dying. Family members made decisions in an emotional climate of overwhelming burden and guilt, because their loved one's life had been robbed of personhood, the changes associated with decline from a dementia-related illness were unrecognized as part of a trajectory of dying, death was both a tragedy and a blessing. Conclusions: Family members had poignant, unresolved emotional needs stemming from their loved one's illness and nursing home placement. Participants were unprepared to make end-of-life treatment decisions and lacked the informational and emotional support of a consistent provider to help with decisions. Family members need assistance in processing difficult and painful emotions, understanding the trajectory of disease, what decisions might impede a natural death, and comfort or palliative care options.
Sensitivity and selectivity in protein structure comparison

Seven protein structure comparison methods and two sequence comparison programs were evaluated on their ability to detect either protein homologs or domains with the same topology (fold) as defined by the CATH structure database. The structure alignment programs Dali, Structal, Combinatorial Extension (CE), VAST, and Matras were tested along with SGM and PRIDE, which calculate a structural distance between two domains without aligning them. We also tested two sequence alignment programs, SSEARCH and PSI-BLAST. Depending upon the level of selectivity and error model, structure alignment programs can detect roughly twice as many homologous domains in CATH as sequence alignment programs. Dali finds the most homologs, 321–533 of 1120 possible true positives (28.7%–45.7%), at an error rate of 0.1 errors per query (EPQ), whereas PSI-BLAST finds 365 true positives (32.6%), regardless of the error model. At an EPQ of 1.0, Dali finds 42%–70% of possible homologs, whereas Matras finds 49%–57%; PSI-BLAST finds 36.9%. However, Dali achieves >84% coverage before the first error for half of the families tested. Dali and PSI-BLAST find 9.2% and 5.2%, respectively, of the 7056 possible topology pairs at an EPQ of 0.1 and 19.5, and 5.9% at an EPQ of 1.0. Most statistical significance estimates reported by the structural alignment programs overestimate the significance of an alignment by orders of magnitude when compared with the actual distribution of errors. These results help quantify the statistical distinction between analogous and homologous structures, and provide a benchmark for structure comparison statistics.
MMP inhibition in abdominal aortic aneurysms. Rationale for a prospective randomized clinical trial.

ABSTRACT: Abdominal aortic aneurysms (AAAs) represent a chronic degenerative condition associated with a life-threatening risk of rupture. The evolution of AAAs is thought to involve the progressive degradation of aortic wall elastin and collagen, and increased local production of several matrix metalloproteinases (MMPs) has been implicated in this process. We have previously shown that tetracycline derivatives and other MMP inhibitors suppress aneurysm development in experimental animal models of AAA. Doxycycline also reduces the expression of MMP-2 and MMP-9 by human vascular wall cell types and by AAA tissue explants in vitro. To determine whether this strategy might have a role in the clinical management of small AAA, we examined the effect of doxycycline on aortic wall MMP expression in vivo. Patients were treated with doxycycline (100 mg p.o. bid) for 7 days prior to elective AAA repair, and aneurysm tissues were obtained at the time of surgery (n= 5). Tissues obtained from an equal number of untreated patients with AAA were used for comparison. By reverse transcription-polymerase chain reaction and Southern blot analysis, MMP-2 and MMP-9 were both found to be abundantly expressed in the aneurysm wall. Preoperative treatment with doxycycline was associated with a 3-fold reduction in aortic wall expression of MMP-2 and a 4-fold reduction in MMP-9 (p < 0.05 compared to untreated AAA). These preliminary results suggest that even short-term treatment with doxycycline can suppress MMP expression within human AAA tissues. Given its pleiotropic effects as an MMP inhibitor, doxycycline may be particularly effective in suppressing aortic wall connective tissue degradation. While it remains to be determined whether MMP inhibition will have a clinically significant impact on aneurysm expansion, it is expected that this question can be resolved by a properly designed prospective randomized clinical trial.
Development of the Iowa bone nutrient food frequency questionnaire based on data from the US Department of Agriculture Continuing Survey of the Food Intake by Individuals.

Abstract An easily-administered food frequency questionnaire (FFQ)/dietary screener was developed for current (adult) and retrospective (adolescent) intakes of nutrients important for bone development and maintenance. This tool quantified serving sizes and nutrients from foods using gender- and age-specific techniques. Nutrients of interest were calcium, vitamin D, caffeine and alcohol, and 15 categories of foods were selected for inclusion based on frequency of intake and nutrient density. Calcium-contributing foods were selected from published dietary intake assessment tools. Foods contributing vitamin D, caffeine and alcohol were selected based on nutrient density and Midwest consumption practices. Serving sizes were quantified in standard serving units or as small, medium and large servings. Food items selected for the FFQ/dietary screener were matched to foods from the United States Department of Agriculture (USDA) Continuing Survey of Food Intakes by Individuals (CSFII). Calcium, caffeine and alcohol values were assigned using CSFII data files at median values per 100 g intake. CSFII midpoint tertile frequency of intake values for males and females 14–18 and 25–45 years old were used to establish serving weights for small, medium and large servings. CSFII data files provide an efficient way for estimating typical intakes, serving sizes and nutrient values for target groups. Age- and gender-derived data provided realistic estimates of nutrient intakes when using FFQ/dietary screener assessment method.
PCOS: a process control extension to operating system/360

This paper discusses the design and implementation of an extension to IBM Operating System/360 that is called PCOS and is intended specifically for use in "real-time" control of IBM manufacturing processes and testing. The most important part of PCOS is a Real-Time Control Program (RTCP) which is initiaatte sdy stem start-up time as a "never-ending" task. The RTCIP controls the execution of application programs and permits system response to requests for their execution within a time on the order of 100 msec. Other contributions are an "express path" for handling input /output operations, an "interpartition communication" program that provides common core storage for use during the execution of application programs, and an appendage to the OS/360 supervisor program to serve a specially designed high-speed multiplexor called the "transmission control unit."
Extracellular proteins needed for C. elegans mechanosensation

The mec-5 and mec-9 genes encode putative extracellular proteins that allow a set of six touch receptor neurons in C. elegans to respond to gentle touch. MEC-5 is a collagen made by the epidermal cells that surround the touch cells. Mutations causing touch insensitivity affect the Gly-X-Y repeats of this collagen. mec-9 produces two transcripts, the larger of which is expressed in the touch cells and two PVD neurons. This transcript encodes a protein with 5 Kunitz-type protease inhibitor domains, 6 EGF-like repeats (2 of the Ca(2+)-binding type), and a glutamic acid-rich region. Missense mutations causing touch insensitivity affect both the EGF-like and Kunitz domains. Since mec-9 loss of function mutations dominantly enhance the touch insensitive phenotype of several mec-5 mutations, MEC-5 and MEC-9 may interact. We propose that these proteins provide an extracellular attachment point for the mechanosensory channels of the touch cells.
Combinatorial regulation of tissue specification by GATA and FOG factors

The development of complex organisms requires the formation of diverse cell types from common stem and progenitor cells. GATA family transcriptional regulators and their dedicated co-factors, termed Friend of GATA (FOG) proteins, control cell fate and differentiation in multiple tissue types from Drosophila to man. FOGs can both facilitate and antagonize GATA factor transcriptional regulation depending on the factor, cell, and even the specific gene target. In this review, we highlight recent studies that have elucidated mechanisms by which FOGs regulate GATA factor function and discuss how these factors use these diverse modes of gene regulation to control cell lineage specification throughout metazoans.
A method of using Hoelder exponents to monitor tool-edge wear in high-speed finish machining

Tool condition monitoring is increasingly important as a widespread application of automated, computer numerically controlled machining in a variety of modern industries. Although a significant amount of research on tool condition monitoring in machining has been conducted during the past few decades, the research is primarily focused on tool flank wear. Less attention is paid to tool-edge wear, which is a critical issue in high-speed finish machining where the feed rate is in the same magnitude as tool edge dimensions, and thus, the tool cutting edge is subjected to extensive mechanical and thermal deformation. The present study fills this important research gap in tool condition monitoring. This paper presents a method of monitoring tool-edge wear in the high-speed finish machining of an aerospace superalloy Inconel 718 by extracting Hoelder exponents from wavelet transform analysis of cutting vibrations. A total of 60 cutting experiments were conducted, covering a range of cutting speed and feed rate conditions. The experimental results show that cutting vibrations increase as tool-edge wear develops. Wavelet transform analysis can be employed to identify single local maxima of the cutting vibration signals. As tool-edge wear develops, the values of Hoelder exponents vary from 0.55 to 0.90. It is suggested that under the cutting conditions tested in the present study, 0.8 can be used as the threshold value of Hoelder exponents to differentiate severe and normal tool-edge wear.
Administrator career paths and decision processes

Purpose – The purpose of this paper is to present qualitative evidence on the processes and forces that shape school administrator career paths.Design/methodology/approach – An embedded case study approach is used to understand more than 100 administrator career transitions within the Delaware education system. Semi‐structured interview data were collected from 48 principals and assistant principals. Coding and analysis occurred through an iterative process, revealing patterns in processes and forces influencing the careers of school administrators.Findings – While some career decisions are self‐initiated, most are influenced in part or entirely by other actors in the system, described as recruiting/tapping, requesting, reassigning, passing over, and removing. In self‐initiated decisions to move or stay, a number of “pushes” and “pulls” are identified. Findings also suggest the decision to stay‐equilibrium is driven by relationships with students and by district support.Research limitations/implications –...
Redshift data and statistical inference

Frequency histograms and the 'power spectrum analysis' (PSA) method, the latter developed by Yu & Peebles (1969), have been widely employed as techniques for establishing the existence of periodicities. We provide a formal analysis of these two classes of methods, including controlled numerical experiments, to better understand their proper use and application. In particular, we note that typical published applications of frequency histograms commonly employ far greater numbers of class intervals or bins than is advisable by statistical theory sometimes giving rise to the appearance of spurious patterns. The PSA method generates a sequence of random numbers from observational data which, it is claimed, is exponentially distributed with unit mean and variance, essentially independent of the distribution of the original data. We show that the derived random processes is nonstationary and produces a small but systematic bias in the usual estimate of the mean and variance. Although the derived variable may be reasonably described by an exponential distribution, the tail of the distribution is far removed from that of an exponential, thereby rendering statistical inference and confidence testing based on the tail of the distribution completely unreliable. Finally, we examine a number of astronomical examples wherein these methods have been used giving rise to widespread acceptance of statistically unconfirmed conclusions.
ON-LINE PROCESSING IN CANDIDATE EVALUATION: The Effects of Issue Order, Issue Importance, and Sophistication

This article reports the results of a study that replicates and extends the impression-driven model of candidate evaluation reported in Lodge, McGraw, and Stroh (1989). This model holds that evaluations are formed and updated on-line as information is encountered, and that as a result, citizens need not rely on specific information available from memory to form their candidate evaluations. In the present work we explore whether the order in which information is encountered, as well as whether information that is personally important, influences the weight accorded to evidence in on-line processing. In addition, differences in information-processing strategies due to political sophistication are examined. The results indicate that important information receives more weight than unimportant information. In addition, the evidence suggests that political sophisticates are more efficient on-line processors than are less sophisticated individuals. The implications of these results for models of candidate evaluation are discussed.
The Federal-State Tempest of Medical Marijuana Taxation: Seeking a Bridge over Troubled Waters

ABSTRACT: Presently, federal income taxation of medical marijuana is the same as for cocaine or heroin; the only permitted adjustment to gross revenues in calculating federal taxable income is cost of goods sold. Where medical marijuana has been legalized, however, state income taxation falls primarily into two groups, with some states permitting nonprofit treatment of dispensaries for state purposes, although they will not receive such treatment for federal tax purposes. Other states make no requirement of nonprofit status, such that state taxation of these enterprises generally follows federal treatment. This disparity in federal-state taxation, although simply stated, has earth-shaking economic implications to the producers, distributors, and users of medical marijuana. Despite recent developments, a potentially extreme federalism problem remains; one that has been characterized as a “war” between the federal government and some states over medical marijuana policy. This “war” has two fronts, due to th...
Optimization, cointegration and diversification gains from international portfolios: an out-of-sample analysis

This study investigates comparative performance of iShares and their underlying market indices in a portfolio context from the perspective of U.S. investors. Two aspects are important. First, portfolios based on standard optimization procedures and a portfolio based on cointegration procedures are created and out-of-sample performance is compared. The portfolio utilizing cointegration inputs shows superior out-of-sample performance. Second, portfolio performance measurement is extended to different holding periods. The findings do not differ.
Recent developments in actinide–ligand multiple bonding

In the last few years, considerable progress has been made in the synthesis and characterization of complexes containing actinide–ligand multiple bonds, especially in regards to isolation of terminal oxo, nitrido and carbene-containing complexes. This review summarizes the synthesis, structure, and reactivity of these complexes, from 2010 until present. These complexes are of interest for a variety of reasons, including their potential use in novel catalytic transformations and their ability to engage the 5f orbitals in metal–ligand bonding. Of particular note are the recent syntheses of the first isolable complex containing the nitride-substituted uranyl ion, [NUO]+, and the first report of an isolable terminal uranium nitride. Considerable progress has also been made toward the syntheses of actinide carbenes and thorium complexes containing metal–ligand multiple bonds.
Limits to Liberalization: Local Culture in a Global Marketplace

Limits to Liberalization: Local Culture in a Global Marketplace. By Patricia M. Goff. Ithaca, NY: Cornell University Press, 2007. 208p. $35.00.To what extent has globalization limited national policy autonomy and eroded national identity? Conventional dialogue on this question has proven unsatisfying and even extreme, emphasizing either the supposed infallibility of markets or the evil of the World Trade Organization. Patricia Goff's book injects much-needed focus and clarity by examining the evolution of efforts by the Canadian government and the European Union to regulate international trade in the culture industries: film, radio, television, publishing, and sound recording.
Astrophysics: Less greedy galaxies gulp gas.

The cool molecular gas from which stars form has been detected in relatively ordinary faraway galaxies. The results point to a continuous fuelling of gas into the star-forming guts of assembling galaxies.
Brain β-spectrin phosphorylation : Phosphate analysis and identification of threonine-347 as a heparin-sensitive protein kinase Phosphorylation site

Phosphorylation of brain spectrin was studied by a combination of in vivo and in vitro approaches. Chemical analysis of phosphate groups on electrophoretically purified mouse brain beta-spectrin yielded a stoichiometry of 3.2 +/- 0.18 mol of PO4/mol of beta-spectrin. The spectrin isolated by chromatographic methods from mouse brain, pig brain, and human erythrocytes yielded 4.1, 5.6, and 3.2 mol of PO4/mol of spectrin heterodimer, respectively. The 32P labeling of spectrin in retinal ganglion cell neurons or NB 2a/d1 neuroblastoma cells with [32P]orthophosphate showed phosphorylation of only beta-spectrin in vivo. Two-dimensional phosphopeptide map analyses showed that most of the in vivo sites on beta-spectrin were phosphorylated by either a heparin-sensitive endogenous cytoskeleton-associated protein kinase or protein kinase A. Phosphoamino acid analysis of in vivo and in vitro phosphorylated beta-spectrin showed that [32P]phosphate groups were incorporated into both serine (>90%) and threonine residues. In vitro, phosphate groups were incorporated into threonine residues by the heparin-sensitive endogenous protein kinase. The amino acid sequence VQQQLQAFNTY of an alpha-chymotryptic 32P-labeled peptide phosphorylated by the heparin-sensitive cytoskeleton-associated endogenous protein kinase corresponded to amino acid residues 338-348 on the beta1 repeat of beta-spectrinG (betaSPIIa) gene. These data suggest that phosphorylation of Thr347, which is localized on the presumptive synapsin I binding domain of beta-spectrinG, may play a role in synaptic function by regulating the binding of spectrin to synaptic vesicles.
A new system for high-resolution DNA sequence mapping in interphase pronuclei ☆

Cosmid clones containing human or hamster inserts have been hybridized in situ and localized with fluorescent reporter molecules in interphase nuclei (pronuclei) obtained after fusion of hamster eggs with either human or hamster sperm. Hamster egg cytoplasm processes the tightly packaged sperm DNA into large diffuse networks of chromatin fiber bundles, providing hybridization targets more extended than those available in somatic interphase cell nuclei. Pronuclear physical distances between hybridization signals were measured in micrometers and correlated to genomic distances determined by restriction fragment analyses, using cosmids from the Chinese hamster DHFR region and from the human Factor VIII/color vision pigment gene region (Xq28). The mean pronuclear distances between hybridization sites were about three times as large as those measured in somatic interphase cells for equivalent genomic distances. The relationship between physical and genomic distances was linear from less than 50 kb to at least 800 kb. The results show that physical distance in the sperm-egg system promises to extend the mapping range obtainable in somatic interphase nuclei below 50 kb and up to at least 800 kb.
Evaluation of a Confinement System for Growout of Channel Catfish Ictalurus punctatus

Rising costs of inputs have created a need to improve catfish production efficiencies. An inexpensive confinement system was evaluated for channel catfish Ictalurus punctatus foodfish production. Barriers were constructed in five 0.1-ha earthen ponds to partition ponds into 1/3 and 2/3 sections. Large fingerling (136 g) catfish were stocked at 11,115 fish/ha in the smaller 1/3 section (shallow end) of the confinement ponds or in open ponds (control). Seining efficiency was significantly greater for the confinement system. Yield and daily growth of food fish were significantly lower and feed conversion ratio higher in the confinement system compared to open ponds. Partial budget analysis showed a net loss of –$313/ha. Additional work is needed to develop inexpensive production systems to capture efficiencies of confinement without decreasing production.
The demonisation of pan-Arab nationalism

Although the denigration and misrepresentation of pan-Arab nationalism existed long before recent attempts to portray Saddam Hussein’s regime as exceptionally heinous, threatening and a major source of terrorism, the demonisation of this profoundly important and evolving political force has been given further impetus by the imperative to justify current US Middle Eastern policy. The fallacies that inform reductionist and hostile approaches to pan-Arabism, including the assumption that it is inherently racist and totalitarian, are here dissected and contextualised, and the evolution of pan-Arab nationalist thought is illuminated in the process.
The multiple traumas of Hurricane Katrina as witnessed by a psychoanalytic first responder

The most disadvantaged New Orleans residents were stranded in the city when the levees broke in the wake of Hurricane Katrina. The author, a psychoanalytic clinician, encountered some of these victims as a first responder in the Red Cross shelters in Dallas, TX. Psychological first aid in such situations involves shoring up defenses and promoting resilience. Clinical and organizational vignettes demonstrate a psychoanalytic approach to psychological first aid and disaster response. Three trauma theories (Bowlby's attachment theory, Hobfoll's conservation of resources theory and Strozier's “ground zero” theory) are used to understand the trauma experienced by those in Dallas shelters.
Teaching Sociology at a Tribal College: Navajo Philosophy as a Pedagogy

This article begins with a brief history of Dine College, the first tribally controlled college in the nation. I then provide an overview of Dine College’s educational philosophy, called Sa’ah Naaghai Bik’eh Hozhoon, and give examples that demonstrate how I apply this SNBH philosophy in my teaching. I discuss my own Dine identity, and explain how that fosters a greater understanding among the students I teach. I also introduce a concept called “the Navajo time bind” that illuminates the challenges I face in teaching sociology to a Navajo population. Overall, this article provides insights about the unique aspects of teaching sociology in a tribally controlled college.
Incidence and characteristics of spinal decompression surgery after the onset of symptoms of amyotrophic lateral sclerosis.

Objective The high incidence of spondylosis in patients at the mean age of onset (55.7 yr) of amyotrophic lateral sclerosis (ALS) can make recognition of ALS as a cause of weakness difficult. Methods To assess the impact of this diagnostic dilemma on neurosurgical practice, we performed a retrospective analysis of a database of more than 1500 patients with motor neuron disease. Results Of 1131 patients with typical, sporadic ALS, 47 (4.2%) underwent decompressive spinal surgery after the onset of retrospectively recognized symptoms of ALS. Among 55 operations in 47 ALS patients, 86% yielded no improvement, 9% produced minor improvement, and only 5% provided significant benefit. Cervical decompression was performed in 56%, lumbar in 42%, and thoracic in 2%. Foot drop was a symptom prompting surgery in 11 patients, and in 10, this finding was subsequently attributed solely to ALS. No differences between ALS patients who underwent spinal decompression and other ALS patients were noted regarding age at symptom onset, severity of impairment at time of diagnosis, or rate of disease progression. Not surprisingly, patients who had spinal surgery tended to have a longer interval between retrospectively recognized symptom onset and diagnosis of ALS. Conclusion A small but significant number of patients with unrecognized ALS undergo spinal surgery that in retrospect may be inappropriate. The possibility of ALS must be considered in the evaluation of patients with weakness even in the presence of radiographic evidence of spondylosis and nerve root or spinal cord impingement.
The geochemistry of Ca, Sr, Ba and Ra sulfates in some deep brines from the Palo Duro Basin, Texas

Abstract The geochemistry of Ca, Sr, Ba and Ra sulfates in some deep brines from the Palo Duro Basin of north Texas, was studied to define geochemical controls on radionuclides such as 90Sr and 226Ra. Published solubility data for gypsum, anhydrite, celestite, barite and RaSO4 were first reevaluated, in most cases using the ion interaction approach of Pitzer, to determine solubility products of the sulfates as a function of temperature and pressure. Ionic strengths of the brines were from 2.9 to 4.8 m, their temperatures and pressures up to 40°C and 130 bars. Saturation indices of the sulfates were computed with the ion-interaction approach in one brine from the arkosic granite wash fades and four from the carbonate Wolfcamp Formation. All five brines are saturated with respect to gypsum, anhydrite and celestite, and three of the five with respect to barite. All are undersaturated by from 5 to 6 orders of magnitude with respect to pure RaSO4. 226Ra concentrations in the brines, which ranged from 10−11.3 to 10−12.7 m, are not controlled by RaSO4 solubility or adsorption, but possibly by the solubility of trace Ra solid solutions in sulfates including celestite and barite.
Isolation of a mutant cell line derived from ICR 2A frog cells hypersensitive to the induction of nondimer DNA damage by solar ultraviolet radiation

A mutant cell line DRP 36, hypersensitive to nondimer DNA damage induced by exposure of cells to the Mylar-filtered solar ultraviolet (UV) radiation produced by a fluorescent sunlamp plus photoreactivating light (PRL) was isolated from the haploid ICR 2A frog cell line. The D0 for mutant cells exposed to this solar UV source was 3.3 kJ/m2 compared with a D0 of 7.3 kJ/m2 for the parental ICR 2A cells. In contrast, DRP 36 and ICR 2A cells exhibited similar levels of survival following 254-nm irradiation which causes the induction primarily of pyrimidine dimers. The cross-sensitivity to additional DNA damaging agents was examined, and it was determined that the DRP 36 cells are also hypersensitive to treatment with γ-rays, ethyl methane sulfonate (EMS), cis-dichlorodiammine platinum (II) (DDP), and 4-nitroquinoline oxide (4-NQO) while exhibiting normal sensitivity tol-phenylalanine mustard (L-PAM), 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) and mitomycin C (MMC).
SU‐E‐T‐799: Improvement in Chest Wall Dose with Volumetric Modulated Arc Therapy for the Treatment of SBRT Lung Lesions

Purpose: This study evaluates the use of volumetric arc therapy (VMAT) for hypo‐fractionated lungtreatments to improve plan conformality and reduce chest wall dose. Methods: Ten patients treated with hypo‐fractionated lungSBRT were retrospectively planned with 270 to 360 degree arc VMAT and results were compared to the 4 – 5 field IMRT plans used for treatment. Prescription doses were 45, 48 or 54Gy in 5, 4 or 3 fractions, respectively. To compare plan quality, various dose‐volume statistics were assessed for the PTV, spinal cord, esophagus, lungs, distal and mainstem bronchi. Conformity index (V(95%Rx)/ V_PTV(95%Rx)) was also evaluated. Monitor units were compared to evaluate plan efficiency. Results: Patient‐averaged PTV D(99%), D(95%), and Dmax were 97.9, 101.2, and 107.8% respectively for VMAT and 98.6, 101.6, and 106.4% respectively for IMRT. Average conformity index was 1.79 for VMAT and 1.96 for IMRT (p<0.01). The most significant normal tissue dose improvement using VMAT was for the chest wall where the average D(30cc) was 24.5 Gy, 19% lower than IMRT (p < 0.01). The average total lung V(20Gy) fell from 5.6% with IMRT to 5% with VMAT but other total lung statistics (V(10Gy), mean dose ) were virtually identical. Average contralateral lung mean dose increased with VMAT (1.5 vs 1.1Gy, p<0.01). VMAT and IMRT maximum doses to cord, esophagus, mainstem and distal bronchi did not differ significantly. On average, MU required for VMAT delivery were 32% less than IMRT. Conclusions: PTV coverage and most normal tissue doses were similar for VMAT and IMRT. Conformity index and chest wall D(30cc) improved with VMAT. Although total lung dose was similar for both plans, mean contralateral lung dose on average was higher for VMAT. The VMAT plans showed improved conformality and reduced chest wall D(30cc) at a cost of increased contralateral lung mean dose. Research agreement with Varian Corporation
Photon spectral characteristics of dissimilar 6 MV linear accelerators

This work measures and compares the energy spectra of four dosimetrically matched 6 MV beams, generated from four physically different linear accelerators. The goal of this work is twofold. First, this study determines whether the spectra of dosimetrically matched beams are measurably different. This study also demonstrates that the spectra of clinical photon beams can be measured as a part of the beam data collection process for input to a three-dimensional (3D) treatment planning system. The spectra of 6 MV beams that are dosimetrically matched for clinical use were studied to determine if the beam spectra are similarly matched. Each of the four accelerators examined had a standing waveguide, but with different physical designs. The four accelerators were two Varian 2100C/Ds (one 6 MV/18 MV waveguide and one 6 MV/10 MV waveguide), one Varian 600 C with a vertically mounted waveguide and no bending magnet, and one Siemens MD 6740 with a 6 MV/10 MV waveguide. All four accelerators had percent depth dose curves for the 6 MV beam that were matched within 1.3%. Beam spectra were determined from narrow beam transmission measurements through successive thicknesses of pure aluminum along the central axis of the accelerator, made with a graphite Farmer ion chamber with a Lucite buildup cap. An iterative nonlinear fit using a Marquardt algorithm was used to find each spectrum. Reconstructed spectra show that all four beams have similar energy distributions with only subtle differences, despite the differences in accelerator design. The measured spectra of different 6 MV beams are similar regardless of accelerator design. The measured spectra show excellent agreement with those found by the auto-modeling algorithm in a commercial 3D treatment planning system that uses a convolution dose calculation algorithm. Thus, beam spectra can be acquired in a clinical setting at the time of commissioning as a part of the routine beam data collection.
High‐frequency instability of the sheath–plasma resonance

Coherent high frequency oscillations near the electron plasma frequency (omega approx. less than omega sub p) are generated by electrodes with positive dc bias immersed in a uniform Maxwellian afterglow plasma. The instability occurs at the sheath-plasma resonance and is driven by a negative RF sheath resistance associated with the electron inertia in the diode-like electron-rich sheath. With increasing dc bias, i.e., electron transit time, the instability exhibits a hard threshold, downward frequency pulling, line broadening and copious harmonics. The fundamental instability is a bounded oscillation due to wave evanescence, but the harmonics are radiated as electromagnetic waves from the electrodes acting like antennas. Wavelength and polarization measurements confirm the emission process. Electromagnetic waves are excited by electrodes of various geometries (planes, cylinders, spheres) which excludes other radiation mechanisms such as orbitrons or beam-plasma instabilities. The line broadening mechanism was identified as a frequency modulation via the electron transit time by dynamic ions. Ion oscillations at the sheath edge give rise to burst-like RF emissions. These laboratory observations of a new instability are important for antennas in space plasmas, generation of coherent beams with diodes, and plasma diagnostics.
Pulmonary hypertension in glycogen storage disease type I.

Glycogen storage disease type I (GSD I) is caused by a deficiency in one of the components of the glucose-6-phosphatase (G-6-Pase) system. Most patients have deficient G-6-Pase activity (GSD Ia) or deficient G-6-Pase translocase activity (GSD Ib). Both of these disorders result in hypoglycaemia, hepatomegaly, lactic acidaemia, hyperlipidaemia and hyperuricaemia, with additional findings of neutropenia in GSD Ib. Long-term complications include growth retardation, gout, hepatic adenomas, osteoporosis and renal disease (Chen and Burchell 1995). A female patient with GSD Ia identified with pulmonary hypertension, adding to the five previously described in the literature, prompted us to conduct a prospective study of the incidence of pulmonary hypertension in these patients.