cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic structural correlation via nonlinear programming techniques

A solution to the correlation between structural dynamic test results and finite element analyses of the same components is presented in this paper. Basically, the method can be categorized as a Levenberg-Marquardt type Gauss-Newton method which requires only the differences between FE modal analyses and test results and their first derivatives with respect to preassigned design variables. With proper variable normalization and equation scaling, the method has been made numerically better-conditioned and the inclusion of the Levenberg-Marquardt technique overcomes any remaining difficulty encountered in inverting singular or near-singular matrices. An important feature is that each iteration requires only one function evaluation along with the associated design sensitivity analysis and so the procedure is computationally efficient.
Changes in the optical quality of the normal eye with age

Average high order wavefront error of the eye increases with age and average pupil size decreases. Consequently the higher order wavefront error is less for older eyes under low luminance levels than younger eyes.
OBSERVATIONS ON THE GROWTH, ECOLOGY AND USES OF MINQUARTIA GUIANENSIS, A HUMID TROPICAL TREE

SUMMARY The ecology, growth behaviour and development of Minquartia guianensis Aubl. (Olacaceae) in light-limiting understorey conditions in the tropical moist forests of Costa Rica is described. It grows well in often impoverished acid soils, on steep terrain and in high rainfall areas. Parasitism may explain its successful regeneration. There is increasing local and foreign demand for its timber, which is hard and extremely durable.
In situ NMR observations of the photolysis of cymantrene and methylcymantrene in supercritical fluids. A new technique using high-pressure NMR

The in situ photolytic exchange of ethylene and hydrogen for carbon monoxide on cymantrene (CpMn(CO)3 , Cp = η5-cyclopentadienyl) and methylcymantrene (MeCpMn(CO)3, MeCp = monomethyl-η5-cyclopentadienyl) dissolved in subcritical and supercritical solvents (CO2 and ethylene) was investigated by high-resolution, high-pressure 1H NMR over the temperature range from −40 to 150 °C and a pressure range from 35 to 2600 bar. Photolytic substitution of ethylene for CO proceeded to completion under all conditions investigated, and only one ethylene was observed to substitute for CO on the manganese complexes even in neat ethylene under extreme conditions of pressure and temperature. Only small amounts of dihydrogen were observed to substitute for CO on cymantrene at 35 °C in a binary solvent mixture of CO2/H2 during photolysis. The 1H chemical shifts of the manganese complexes and their ethylene substituted products were found to be linearly dependent on density with temperature and solvent dependence also observed...
Noncovalent Interactions of Long-Chain Perfluoroalkyl Acids with Serum Albumin

Preferential distribution of long-chain perfluoroalkyl acids (PFAAs) in the liver, kidney, and blood of organisms highlights the importance of PFAA-protein interactions in PFAA tissue distribution patterns. A serum protein association constant may be a useful parameter to characterize the bioaccumulative potential and in vivo bioavailability of PFAAs. In this work, association constants (Ka) and binding stoichiometries for PFAA-albumin complexes are quantified over a wide range of PFAA:albumin mole ratios. Primary association constants for perfluorooctanoate (PFOA) or perfluorononanoate (PFNA) with the model protein bovine serum albumin (BSA) determined via equilibrium dialysis are on the order of 106 M−1 with one to three primary binding sites. PFNA was greater than 99.9% bound to BSA or human serum albumin (HSA) at a physiological PFAA:albumin mole ratio ( 4). Nanoelectrospray ionization mass spectrometry (nanoESI-MS) data ...
Bloch–Ogus properties for topological cycle theory

Abstract We reformulate and extend “morphic cohomology” developed by the author and H.B. Lawson so that, together with “Lawson homology”, it satisfies the axioms of S. Bloch and A. Ogus for a “Poincare duality theory with supports” on complex quasi-projective varieties.
Adherence to antiretroviral medications in HIV/AIDS care: a narrative exploration of one woman's foray into intentional nonadherence.

Intentional nonadherence occurs when patients deliberately do not take their medications. This phenomenon has not been studied within HIV/AIDS care, a significant omission due to the difficulty of adherence to antiretroviral medications for HIV/AIDS patients and the severe risks associated with nonadherence. The purpose of this study was to explore, using HIV-positive women’s own recollections collected in diary format, how and why women living with HIV/AIDS intentionally fail to adhere to their antiretroviral medications. We examined the journal entries of 20 HIV-positive women written during a 1-month period. Although three participants wrote about their intentional nonadherence, the journal entries of only one woman are presented in detail. This woman’s story highlights the complex reasons for intentional nonadherence and the social/emotional ramifications of such nonadherence. Results suggest that intentional nonadherence is emotionally trying for patients and that patients’ adherence decisions are co...
Thermoelastic plastic metals with mass diffusion

In this paper we develop new governing equations for contact stresses in metals. They include the coupled effects of thermal elastic-plastic theory, including balance and constitutive laws. While the results are quite general, this work had it origins in describing the metal cutting process. As one example, the resulting equations can be applied to precision and ultraprecision cutting.
A project centered programming language course

A programming language course is difficult to organize because of the diversity of languages and concepts discussed. A Lisp-based project described here provides a unifying context within which to demonstrate programming language features such as data abstraction, packages, and overloading. This approach has proven to be a successful strategy in organizing a programming language course.
City, identity and dystopia: Writing Lagos in contemporary Nigerian novels 1

This article aims to explore the poetics and politics of urban spaces and identities in an African metropolis by studying how novels such as Chris Abani's Graceland (2004), Sefi Atta's Everything Good Will Come (2005), Helon Habila's Waiting for an Angel (2002), and Okey Ndibe's Arrows of Rain (2000) map the geography of the city and portray its people and the myriad of ways they negotiate selves and identities in the spaces they inhabit. The article demonstrates how the novels of the city configure urban identities as woven not only through the rich cultural textualities that people live in but also through emerging subjectivities of crisis that configure responses to contemporary realities experienced as dystopian. Within these dystopian spaces, shaping identities becomes fundamentally political: the article traces how, across the range of the novels studied, disillusionment with received imaginings of postcolonial nationhood and identity engenders a mood of inertia and complacency, but also contains a ...
Dynamic analysis of large datasets with animated and correlated views: VAST 2012 Mini Challenge # award: Honorable mention for good use of coordinated displays

In this paper, we introduce a GPU-accelerated visual analytics tool, AVIST. By adopting the in-situ visualization architecture on the GPUs, AVIST supports real-time data analysis and visualization of massive scale datasets, such as VAST 2012 Challenge dataset. The design objective of the tool is to identify temporal patterns from large and complex data. To achieve this goal, we introduce three unique features: automatic animation, disjunctive data filters, and time-synced visualization of multiple datasets.
Numerical studies of electrode plasma formation and expansion in high power charged particle beam diodes

High-power diodes that generate intense electron beams are useful in many applications such as generating intense microwave radiation, pumping lasers for driving inertial fusion targets, and producing bremsstrahlung x-rays for flash radiography and nuclear weapon effects simulations. The core component of a high-power diode consists of a two-electrode acceleration gap in which a high voltage pulse is applied between the anode and the cathode, causing surface emission of electrons, which initially follow the electric field lines toward the anode. Electron energy deposition on the anode eventually leads to desorption and ionization of gases from the anode surface, forming a plasma and allowing for space charge limited flow of ions. Expansion of the unconfined anode plasma into the gap region can ultimately lead to a short circuit, a phenomenon known as “gap closure”, which limits the pulse length and ultimately limits the production of radiation. NRL is beginning a multi-year research effort to study these surface plasmas both experimentally [R. J. Allen, this Conference] and numerically. It is hoped that this effort will produce a better understanding of these plasmas and lead to improved models for particle-in-cell (PIC) codes.
Optical lens compression via transformation optics

Transformation optics is widely associated with the design of unconventional electromagnetic devices, such as electromagnetic cloaks or concentrators. However, a wide range of conventional optical devices with potentially advantageous properties can be designed by the transformation optical approach. For example, a coordinate transformation can be introduced that compresses a region of space, resulting in an overall decrease in the thickness of an optical instrument such as a lens. The optical properties of a transformed lens, such as Fresnel reflection or aberration profile, are equivalent to those of the original lens, while the transformed lens and the bounding transformation optical material are thinner than the original lens. This approach to flattening the profile of a lens represents an advantage over the use of a higher dielectric material because it does not introduce greater Fresnel reflections or require a redesign of the basic optic. Though transformation optical media are generally anisotropic, with both electric and magnetic response, it is possible to arrive at a dielectric-only transformation optical distribution for a lens interacting with transverse-magnetic (TM) polarized light. The dielectric-only distribution can be implemented using broad-band, low-loss metamaterials. Lens designs for both a full transformation and a dielectric-only implementation are discussed and confirmed via finite-element simulations.
Active control of laminated cylindrical shells using piezoelectric fiber reinforced composites

Abstract This paper deals with the analysis of active constrained layer damping (ACLD) of laminated thin composite shells using piezoelectric fiber reinforced composite (PFRC) materials. The constraining layer of the ACLD treatment is considered to be made of the PFRC materials. A finite element model of the smart composite shells integrated with the patches of such ACLD treatment has been developed to demonstrate the performance of these patches on enhancing the damping characteristics of thin symmetric and antisymmetric cross-ply and anti-symmetric angle ply laminated composite shells. The effect of variation of piezoelectric fiber orientation in the constraining PFRC layer on the control authority of the patches has also been investigated.
Pulsed carbon dioxide and erbium-YAG laser resurfacing: a comparative clinical and histologic study

BACKGROUND: The recent introduction of pulsed erbium-YAG (Er:YAG) laser technology has been accompanied by relatively few clinical studies with widely varying claims regarding post-operative healing, clinical side effects and efficacy. OBJECTIVE: The aim was to evaluate comparatively pulsed CO 2 and Er:YAG lasers with regard to clinical side effects, post-operative healing and efficacy when equivalent depths of histologic damage were produced. METHODS: Bilateral periocular or perioral sites were treated using a pulsed CO 2 laser on one side and a pulsed Er:YAG laser on the opposite side. Attempts were made to produce equivalent depths of coagulation (CO 2 ) and ablation (erbium). RESULTS: Results showed almost equivalent post-operative healing. However, the pulsed CO 2 laser proved more effective in the treatment of moderate and deep rhytids. CONCLUSION: When equivalent depths of coagulation and ablation are compared, the healing time is similar. CO 2 proved to be more efficacious in the treatment of peri...
Turbulent decay of a passive scalar in the Batchelor limit: Exact results from a quantum-mechanical approach

We show that the decay of a passive scalar \ensuremath{\theta} advected by a random incompressible flow with zero correlation time in the Batchelor limit can be mapped exactly to a certain quantum-mechanical system with a finite number of degrees of freedom. The Schr\"odinger equation is derived and its solution is analyzed for the case where, at the beginning, the scalar has Gaussian statistics with correlation function of the form ${e}^{\ensuremath{-}|x\ensuremath{-}y{|}^{2}}.$ Any equal-time correlation function of the scalar can be expressed via the solution to the Schr\"odinger equation in a closed algebraic form. We find that the scalar is intermittent during its decay and the average of $|\ensuremath{\theta}{|}^{\ensuremath{\alpha}}$ (assuming zero mean value of \ensuremath{\theta}) falls as ${e}^{\ensuremath{-}{\ensuremath{\gamma}}_{\ensuremath{\alpha}}\mathrm{Dt}}$ at large $t,$ where $D$ is a parameter of the flow, ${\ensuremath{\gamma}}_{\ensuremath{\alpha}}=\frac{1}{4}\ensuremath{\alpha}(6\ensuremath{-}\ensuremath{\alpha})$ for $0l\ensuremath{\alpha}l3,$ and ${\ensuremath{\gamma}}_{\ensuremath{\alpha}}=\frac{9}{4}$ for $\ensuremath{\alpha}g~3,$ independent of \ensuremath{\alpha}.
S-phase feedback control in budding yeast independent of tyrosine phosphorylation of p34cdc28.

IN somatic cells, entry into mitosis depends on the completion of DNA synthesis. This dependency is established by S-phase feed-back controls that arrest cell division when damaged or unreplicated DNA is present1. In the fission yeast Schizosaccharomyces pombe, mutations that interfere with the phosphorylation of tyrosine 15 (Y15) of p34cdc2, the protein kinase subunit of maturation promoting factor, accelerate the entry into mitosis and abolish the ability of unreplicated DNA to arrest cells in G2 (ref. 2). Because the tyrosine phosphorylation of p34cdc2 is conserved in S. pombe3, Xenopus4, chicken5 and human6cells, the regulation of p34cdc2-Y15 phosphorylation could be a universal mechanism mediating the S-phase feedback control and regulating the initiation of mitosis7,8. We have investigated these phenomena in the budding yeast Saccharomyces cerevisiae. We report here that the CDC28 gene product (the S.cerevisiae homologue of cdc2) is phosphorylated on the equivalent tyrosine (Y19) during S phase but that mutations that prevent tyrosine phosphorylation do not lead to premature mitosis and do not abolish feedback controls. We have therefore demonstrated a mechanism that does not involve tyrosine phosphorylation of p34 by which cells arrest their division in response to the presence of unreplicated or damaged DNA. We speculate that this mechanism may not involve the inactivation of p34 catalytic activity.
Corticosterone Regulation of Insulin-Like Growth Factor I, IGF-Binding Proteins, and Growth in Streptozotocin-Induced Diabetic Rats

The experiments reported herein were conducted to determine how corticosterone regulates growth and plasma insulin-like growth factor (IGF) I and IGF-binding protein (IGFBP) concentrations in normal and streptozotocin (STZ)-induced diabetic rats. Males were bilaterally adrenalectomized (Ax) or sham Ax and given intravenous injections of 0, 30, or 65 mg STZ per kg body wt (0, 30, or 65 STZ) to induce varying degrees of insulin deficiency and implanted with 100-mg pellets containing 0, 40, or 80% corticosterone in cholesterol. Changes in plasma IGFBP concentrations were determined by Western ligand blotting or immunoblots. Neither IGFBP-5 nor IGFBP-6 was detected in anyof the treatment groups. Plasma IGFBP-2 was elevated and IGF-I was reduced in the nondiabetic Ax rats compared with sham Ax controls, but plasma IGFBP-3 and -4 were not significantly changed. Adrenalectomy had no affect on tibial growth or plasma IGFBP-1 in these animals. Plasma IGF-I, IGFBP-1and -3, and tibial growth were equal among 0, 30, and 65 STZ Ax rats that did not receive corticosterone. Plasma IGFBP-4 was inversely related to the amount of STZ injected in these animals, and IGFBP-2 was elevated in those given the high dose of STZ. In the 0 STZ Ax rats, plasma IGF-I and IGFBP-3 increased in proportion to the corticosterone implant dose, but IGFBP-1 was unaffected. By contrast, IGF-I and IGFBP-3 were unaltered by corticosterone in the 30 STZ Ax rats, and IGFBP-1 increased in proportion with the dose of corticosterone. In the 65 STZ rats given 40% corticosterone, IGFBP-3 was elevated, but IGF-I was not changed. However, both of these parameters were reduced considerably in the 80% corticosterone rats. Plasma IGFBP-1 increased in direct proportion to the corticosterone implant dose in the 30 and 65 STZ rats but was relatively unchanged inthe 0 STZ rats. These results indicate that elevated corticosterone production is largely responsible for the reduced growth and changes in plasma concentrations of IGF-I and IGFBPs associated with IDDM. Plasma IGF-I and tibial growth are normally correlated in nondiabetic rats but were not inthe corticosterone-treated animals; thus, corticosterone contributes to IGF-I resistance in vivo. The effect of corticosterone on the plasma IGFBPs was most striking in the insulin-deficient rats, suggesting that the ability of corticosterone to modify circulating concentrations of IGFBPs is enhanced by insulin deficiency. The rise in plasma IGFBP-1 and the reduction in IGFBP-4 in rats withIDDM is due in part to corticosterone. However, IGFBP-2 was reduced to nearly nondetectable levelsby both doses of corticosterone. The rise in IGFBP-2 in the Ax 65 STZ rats and the decrease in IGFBP-4 in both groups of STZ-injected Ax rats not given corticosterone appears to be due to insulin deficiency per se, rather than to corticosterone. In all groups, plasma IGFBP-4 and tibial growth were inversely related to the corticosterone implant dose, suggesting that IGFBP-4 may have a growth-promoting role in vivo.
The Effect of a Meal and Water Loading on Heart Rate Variability in Children with Functional Dyspepsia

Background Alteration in autonomic function has been implicated as a possible pathophysiologic mechanism in functional dyspepsia (FD) in adults.
Estimation of magnesium and purification of chlorophyll from Chlorobium thiosulphatophilum.

Chlorobium thiosulphatophilum was grown under conditions similar to those described by Larsen1. ‘Chlorobium chlorophyll’ (bacterioviridin) was extracted from the cells with 80 per cent methanol, transferred to ether, washed with water and dried over anhydrous sodium sulphate. The volume of the solution was reduced by evaporation under nitrogen, and the bulk of the chlorophyll precipitated by the addition of petroleum ether (b.p. 60–90). The chlorophyll was collected on talcum and washed with petroleum ether (b.p. 30–60) until the washings were colourless. The chlorophyll was removed from the talcum with acetone, transferred to ether, and washed with water. After drying, the solution was concentrated under vacuum, an equal volume of petroleum ether (b.p. 60–90) containing 4 per cent tetrahydrofuran added, and the solution adsorbed on to a sucrose column. The tetrahydrofuran was employed as a means of preventing precipitation of the chlorophyll in the column2. The column was developed by stepwise elution with isopropyl alcohol (0.75–2.0 per cent) in petroleum ether (b.p. 60–90 °) containing 2 per cent tetrahydrofuran. The chlorophyll zone was cut out, dissolved in ether, and chromatographed as before. The absorption spectrum of the chlorophyll in ether was obtained on a Cary recording spectrophotometer. Peaks at 650, 575, 530, 425, and 406 mµ, indicated that this chlorophyll was the ‘650’ type described by Stanier and Smith3, and that the organism studied was similar to or identical with Chlorobium thiosulphatophilum, strain L.
Comparison of Treatment Results Between Adult and Juvenile Nasopharyngeal Carcinoma

Purpose Nasopharyngeal carcinoma (NPC) has a bimodal age distribution. In contrast to the adult variant, little is known about the juvenile form. This study examined the treatment results between adult (aNPC) and juvenile NPC (jNPC) patients for future treatment considerations in jNPC. Methods and Materials The jNPC population included 53 patients treated at two institutions between 1972 and 2004. The aNPC population included 84 patients treated at one institution. The patients had received a median dose of 66 Gy of external beam radiotherapy and 72% underwent chemotherapy. The mean follow-up for surviving patients was 12.6 years for jNPC and 6.6 years for aNPC. Results The jNPC patients presented with more advance stages than did the aNPC patients (92% vs. 67% Stage III-IV, p = .006). However, jNPC patients had significantly better overall survival (OS) than did aNPC patients. The 5-year OS rate was 71% for jNPC and 58% for aNPC ( p = .03). The jNPC group also demonstrated a trend for greater relapse-free survival than the aNPC group (5-year relapse-free survival rate, 69% vs. 49%; p = .056). The pattern of failure analysis revealed that the jNPC patients had greater locoregional control and freedom from metastasis but the differences were not statistically significant. Univariate analysis for OS revealed that age group, nodal classification, and chemotherapy use were significant prognostic factors. Age group remained significant for OS on multivariate analysis, after adjusting for N classification and treatment. Conclusion Despite more advance stage at presentation, jNPC patients had better survival than did aNPC patients. Future treatment strategies should take into consideration the long-term complications in these young patients.
Enantioselective synthesis of (+)-cleomeolide, the structurally unique diterpene lactone constituent of Cleome viscosa

Abstract The first total synthesis of (+)-cleomeolide has been accomplished in enantioselective fashion from optically pure Wieland-Miescher ketone.
Distribution and Community Structure of Estuarine Copepods

Distribution, abundance, and community structure were studied over a 30 month period in the planktonic copepod community of the estuaries near Beaufort, North Carolina. Many of the copepod species showed a demersal distribution during the day and entered the surface waters at night. Several species were largely confined to vegetated littoral areas during the day. The copepod community showed consistent trends of seasonal abundance and succession of dominant species which differed greatly from those found by previous workers, whose methods were inadequate to sample quantitatively the small, demersal copepods which dominated the community. Copepod abundances were higher than found in previous studies and were correlated with water temperature. Species composition changed from a winter community dominated byCentropages spp., to a spring community dominated byAcartia tonsa, to a summer community jointly dominated byParacalanus crassirostris andOithona spp. Copepods were much more important grazers in these estuaries than previous studies had concluded.
Stable Ga–Mg–Zn quasi-periodic crystals with pentagonal dodecahedral solidification morphology

The discovery in 1984 by Shechtman and co-workers of an Al–Mn alloy phase that exhibited a sharply peaked diffraction pattern with icosahedral point symmetry (m) was a major development in crystallography1. It was the first demonstration that quasi-periodic structures with fivefold symmetry axes, which had been described in the mathematical literature and whose sharp reciprocal lattice peaks could be indexed with two sets of incommensurate basis vectors, did actually occur in nature. This discovery has been followed by intense experimental and theoretical work; many more icosahedral and decagonal crystals have been discovered, and the theory describing the quasi-periodic lattices and their defects was greatly developed2–4. With one exception, all quasi-periodic crystals that have been discovered until now are metastable; they are produced by non-equilibrium methods, such as melt quenching, ion-beam mixing and sputtering, and upon heating they transform to phases with a periodic crystal structure. The only stable quasi-periodic crystal that was known is found in the Al–Li–Cu system, and has a striking rhombic triacontahedral solidification morphology5–7. We report here the discovery in the Ga–Mg–Zn system of a second stable quasi-periodic crystal with a pentagonal dodecahedral solidification morphology.
Racial and ethnic differences in physical activity and bone density: National Health and Nutrition Examination Survey, 2007-2008.

Introduction Participation in regular physical activity (PA) may help maintain bone health as people age. However, most American adults do not engage in the recommended minimum levels of PA, and there are racial/ethnic differences in PA participation. This study aimed to determine whether current physical activity is related to bone density in a racially/ethnically diverse sample after controlling for age, sex, body mass index, poverty–income ratio, tobacco use, vitamin D and calcium intake, and use of osteoporosis medications.
Signal-anticipating in local voltage control in distribution systems

In this paper, we consider the signal-anticipating behavior in local volt/var control in distribution systems. We define a voltage control game, and show that the signal-anticipating voltage control is the best response algorithm of the voltage control game. We further show that the voltage control game has a unique Nash equilibrium, characterize it as the optimum of a global optimization problem, and establish its asymptotic global stability. We then introduce the notion of the price of signal-anticipating (PoSA) to characterize the impact of the signal-anticipating in local voltage control, and use the gap in cost between the network equilibrium in the signal-taking voltage control and the Nash equilibrium in the signal-anticipating voltage control as the metric for PoSA. We characterize how the PoSA scales with the size, topology, and heterogeneity of the power network for a few special cases. We find that the stronger the coupling between different buses is, the larger the PoSA is; the linear network gives the largest PoSA among all possible topologies, but as the size of the network increases, the PoSA will saturate.
The Resource-Based View of the Firm: Does It Go Far Enough in Shedding the Assumptions of the S-C-P Paradigm?

In this essay, the authors discuss the link between the new resource-based view of the firm and the old structure-conduct-performance (S-C-P) paradigm. The authors find that the resource-based view...
Optimizing LC-MS-MS determination of microcystin toxins in natural water and drinking water supplies

The performance of a solid phase extraction (SPE) LC-MS-MS procedure for determining microcystins (MC) in water was investigated. Six MC, MCRR, MCYR, MCLR, MCLA, MCLF and MCLW, were determined using positive ion electrospray (+ESI) with separation on a C8 column eluted with a methanol–water gradient containing 15 mM ammonium formate and 0.006% acetic acid. Each MC, as well as the internal standard and surrogate, were detected by two transitions. Isocratic and gradient separations were examined to increase the resolution of MCRR and MCLF as all known naturally occurring MC elute between these two variants. Analysis of fortified laboratory reagent water as well as bloom samples from northern California provided performance information. Cell lysis, accomplished by freeze-thawing samples, was required to determine total sample toxins as 93 to 99% of the toxins were intracellular. Up to 98% of dissolved MC were lost by sorption in filter cartridges, but satisfactory recoveries were obtained with polypropylene filters after the filtrate was combined with a methanol rinse. C18 SPE required elution with trifluoroacetic acid (TFA) for acceptable recoveries of the arginine-containing MC. Freezing was required to preserve MC which degraded rapidly by microbial metabolism at 4 °C after an approximate 10 day lag period. With the optimized method the experimental Method Detection Limits (MDL) for both quantitation and confirmation transitions for the arginine-containing MC ranged from 0.03 to 0.04 μg L−1. Laboratory reporting limits (or LOQ) of 0.1 and 0.2 μg L−1 were confirmed by analyzing surface water samples where accuracy averaged 65 to 70%. Measurement of total MC in bloom samples was reproducible with relative standard deviations of 8.3 to 12%. The study demonstrates the importance of sample preservation, sample workup and quality control procedures in reliable MC determination using modern LC-MS-MS instruments.
Necrolytic migratory erythema as the only presenting sign of a glucagonoma.

Abstract We describe a 39-year-old man with a 3-year history of a recalcitrant psoriasiform eruption that was accentuated in the intertriginous areas. Hsitopathology was consistent with psoriasis. A glucagon level was 744 pg/mL with the upper limit of normal being 130 pg/mL. Computed tomographic scan of the abdomen revealed a 5-cm mass in the tail of the pancreas. The tumor was removed and found to be a glucagonoma (pancreatic islet tumor). The clinical eruption resolved promptly with surgical excision. Neither the clinical eruption nor the tumor has recurred for 6 months. The course of disease confirms the diagnosis of necrolytic migratory erythema associated with a glucagonoma.
How Cytokines Signal Messages Wityhin Cells

The intracellular signaling pathways used by cytokines to modulate the activity of immune effector cells have been the focus of intensive research. Cytokines interact with specific receptors on the plasma membrane, and this information is transduced into internal signals, often involving a cascade of kinases. These signals activate substrate proteins that serve as effectors within the cell. A number of protein kinase C substrates have been characterized. The function of one of these substrates, known as MARCKS (myristoylated alanine-rich C kinase substrate), appears to be important to the control of macrophage and neutrophil motility and may partially explain the modes of action of tumor necrosis factor and interleukin-8
Replica Exchange Statistical Temperature Molecular Dynamics Simulations of Peptide Dimerization

We present a new computer simulation algorithm called Replica Exchange Statistical Temperature Molecular Dynamics that combines the multicanonical sampling technique of Statistical Temperature Molecular Dynamics with temperature replica exchange. This algorithm is related to Wang-Landau sampling but uses a dynamical update of the density of states to achieve flat energy sampling within a replica-dependent temperature range. This algorithm is used to investigate the thermodynamics of dimerization of two polypeptide chains. Three two-peptide systems are investigated: two hydrophobic peptides, two hydrophilic peptides, and one of each. Each monomer is modeled using a coarse-grained peptide model that has an α-helix as the lowest energy configuration. For each dimer system, interesting folding behavior is observed. It is found that at low temperatures, both peptides are helical and the lowest-energy configuration maximizes inter-peptide contact; at high temperatures, both peptides are random coils; and at intermediate temperatures, one peptide is folded and the other unfolded. Formation of the peptide dimer causes one peptide to fold at a higher temperature than an isolated monomer and the other to fold at a lower temperature than an isolated monomer. Dimerization causes one peptide to become more stable and the other peptide to become less stable. It is also shown that at intermediate temperatures, neither peptide adopts a random coil configuration: the helical peptide induces a conformational change in the unfolded peptide. The Potential Energy Surface (PES) is also determined for each dimer and the effect of hydrophobic/hydrophilic nature of the peptide on the PES is discussed.
BMP signaling in axon regeneration

Neuronal competence to re-extend axons and a permissive environment that allows growth cone navigation are two major determinants for successful axon regeneration. Here, we review the roles of bone morphogenetic protein (BMP) signaling in mediating both neuronal and glial injury responses after CNS injury. BMPs can activate a pro-regenerative transcription program in neurons through Smad-mediated canonical pathway, or act locally on cytoskeleton assembly at distal axons via non-canonical pathways. Emerging evidence implicates retrograde BMP signalosomes in connecting the cytoskeletal and nuclear responses. In addition, BMP/Smad signaling modulates neurotrophin-mediated axonal outgrowth, and interacts with the epigenetic machinery to initiate epigenetic reprogramming for axon regeneration. Besides their influences on neurons, BMPs also regulate astrogliosis, inflammatory processes, and neural progenitor cell differentiation at the injury site, all of which can either positively or negatively modify the injury microenvironment. Lastly, an increasing number of BMP signaling partners, sensitizers, and downstream effectors collectively fine-tune the signaling intensity and spatiotemporal dynamics of BMP activity in an integrated signaling network during axon regeneration.
Organizational size, rules, and surveillance☆

Abstract Direct surveillance and the development of formal rules (including record keeping to evaluate participant performance) are two important mechanisms of bureaucratic control. The hypothesis that as organization size increases, formal rules increasingly replace organizational surveillance is advanced. By using data from the 1960 census, Occupations by Industry, and the 1958 United States Census of Manufactures, the hypothesis is tested on two groupings of industrial organizations. Data on both groups support the hypothesis. Theoretical implications of the results are discussed.
The Designability Hypothesis and Protein Evolution

The usage of protein folds in nature is known to be non-uniform: a few folds are used often, while most others are used relatively rarely. What makes one fold more successful than another? The designability explanation, which posits that successful folds have an exponentially larger number of compatible sequences, is critically reviewed, and compared with other structural and functional explanations. It is argued that designability is one component of fold fitness, but most likely not a dominant one.
THE ELIMINATION OF DISCREPANCIES BETWEEN OBSERVED AND CALCULATED P.D. OF PROTEIN SOLUTIONS NEAR THE ISOELECTRIC POINT WITH THE AID OF BUFFER SOLUTIONS

1. It had been noticed in the previous experiments on the influence of the hydrogen ion concentration on the P.D. between protein solutions inside a collodion bag and aqueous solutions free from protein that the agreement between the observed values and the values calculated on the basis of Donnan's theory was not satisfactory near the isoelectric point of the protein solution. It was suspected that this was due to the uncertainty in the measurements of the pH of the outside aqueous solution near the isoelectric point. This turned out to be correct, since it is shown in this paper that the discrepancy disappears when both the inside and outside solutions contain a buffer salt. 2. This removes the last discrepancy between the observed P.D. and the P. D. calculated on the basis of Donnan's theory of P.D. between membrane equilibria, so that we can state that the P.D. between protein solutions inside collodion bags and outside aqueous solutions free from protein can be calculated from differences in the hydrogen ion concentration on the opposite sides of the membrane, in agreement with Donnan's formula.
Control of solvent evaporation in hen egg white lysozyme crystallization

An investigation of the role of solvent evaporation in tetragonal lysozyme crystallization was preformed with a device that employs N2(g) to control the evaporation of solvent from a micro-volume crystallization hanging drop. The number of crystals was found to vary with the rate at which the final supersaturation level was achieved. It was found that the more rapid the approach to supersaturation the larger the number of crystals. Accordingly, the crystals reached a smaller terminal size. Elongation of the (110) face parallel to the four-fold axis was observed with the slower evaporation rates.
Amino-terminal Deletions Enhance Aggregation of β-Amyloid Peptides in Vitro

beta-Amyloid protein, which assembles into pathological aggregates deposited in Alzheimer's disease brain tissue, exhibits N-terminal heterogeneity both in vitro and in vivo. To investigate the effects of this N-terminal heterogeneity on the assembly characteristics and biophysical properties of beta-amyloid, we synthesized a series of peptides with progressively shortened N termini (initial residues at positions beta 1, beta 4, beta 8, beta 12, and beta 17) and C termini extending to residue beta 40 or beta 42. We report that peptides with N-terminal deletions exhibit enhanced peptide aggregation relative to full-length species, as quantitatively assessed by sedimentation analyses. Overall, sedimentation levels were greater for peptides terminating at residue beta 42 than for those terminating at residue beta 40. To determine if established biophysical features of the full-length protein were maintained in the truncated peptides, structural and bioactive properties of these peptides were examined and compared. Full-length and truncated peptides exhibiting aggregation showed circular dichroism spectra consistent with predominant beta-sheet conformation, fibrillar morphology under transmission electron microscopy, and significant toxicity in cultures of rat hippocampal neurons. These data demonstrate that N-terminal deletions enhance aggregation of beta-amyloid into neurotoxic, beta-sheet fibrils and suggest that such peptides may initiate and/or nucleate the pathological deposition of beta-amyloid.
Indicators of Hospital Closure Under PPS and Blue Cross/Blue Shield Cost-Based Reimbursements

Abstract Using an adaptation of discriminant analysis on a sample of 120 hospitals in the state of Alabama, this paper illuminates characteristics of hospitals closed due to financial failure under PPS and cost-based Blue Cross/Blue Sliield reimbursement systems. The results show high debt levels, poor revenue and cost ratios, poor utilization management, and the inability to collect effectively on outstanding accounts in the year prior to hospital failure.
Elevated blood glucose levels and satiety in the rat

Thirteen rats were placed on a feeding schedule of two 3 hr periods of food availability daily. blood glucose levels of the experimental animals were altered by intraperitoneal injection of 8 ml of 2, 5, 8, 12, 16, 20 and 25 percent glucose solutions and by intragastric loading of 8 ml of 25, 50 and 65 percent glucose solutions in 10 different feeding experiments. In 4 additional experiments, experimental animals received intraperitoneal injections of 8 ml of 12, 16, 20 and 25 percent solutions of mannitol, a non-metabolizable sugar-alcohol. Controls always received identical quantities of mammalian Ringer's solution administered via the same route as in the experimentals. Another set of 20 rats was used to determine glucose tolerance curves for each concentration of glucose and mannitol administered. No food intake depression occurred following intraperitoneal injections of 2, 5, 8 and 12 percent glucose, 12 percent mannitol and following intragastric loading of 25, 50 and 65 percent glucose. However, intraperitoneal injections of 16, 20 and 25 percent glucose and mannitol caused depression of food intake. No depression of food intake occurred following intragastric loading of 50 and 65 percent glucose solutions which raised blood glucose levels a minimum of 43 mg percent and 55 mg percent above basal, respectively, for the duration of the 3 hr feeding period. These minimum blood glucose levels greatly exceed normal values following a meal. It was concluded that blood glucose level per se is not an important feedback parameter in the long-term control of food intake, and the depression in food intake following intraperitoneal injections of 16, 20 and 25 percent glucose and mannitol solutions was due to an abnormal physiological condition.
Structural ceramic composites

Abstract Major recent advances: Near-stoichiometric, small-diameter SiC fibers with excellent properties are now available. A new polycrystalline oxide fiber offers significantly improved temperature limits. Oxide fiber coatings to substitute for C and BN for deflecting cracks and promoting distributed damage appear feasible. Two show substantial low-temperature plasticity in constrained loading. Properties of SiC–BN–SiC and coatingless oxide composites have been improved markedly, but combustion atmospheres have proven more problematic than thought for the former.
Effects of opiates on neuronal development in the rat cerebral cortex

Quantitative morphological characteristics of cells in the primary somatosensory cortex of 6-day-old rats were examined following continuous maternal administration of morphine (10 mg/kg/day), naltrexone (10 mg/kg/day), or saline vehicle from gestation day 12. Naltrexone reduced neuronal packing density and significantly increased cortical thickness but had not effect on neuronal number, while morphine reduced neuronal packing density and the number of neurons without affecting cortical thickness. These results suggest that blockade of endogenous opioid function during development enhances neuronal maturation in this brain region, while perinatal morphine administration might act to restrict cortical cell proliferation and maturation. Thus, the effect of ontogenetic activation of opioid receptors by endogenous opioid compounds could be similar to but less severe than the effect of exogenous opiate exposure on cortical cell development.
Lobbying and advocacy for the public's health: what are the limits for nonprofit organizations?

Nonprofit organizations play an important role in advocating for the public's health in the United States. This article describes the rules under US law for lobbying by nonprofit organizations. The 2 most common kinds of non-profits working to improve the public's health are "public charities" and "social welfare organizations." Although social welfare organizations may engage in relatively unlimited lobbying, public charities may not engage in "substantial" lobbying. Lobbying is divided into 2 main categories. Direct lobbying refers to communications with law-makers that take a position on specific legislation, and grassroots lobbying includes attempts to persuade members of the general public to take action regarding legislation. Even public charities may engage in some direct lobbying and a smaller amount of grassroots lobbying. Much public health advocacy, however, is not lobbying, since there are several important exceptions to the lobbying rules. These exceptions include "non-partisan analysis, stud...
On the solution of large, structured linear complementarity problems: The block partitioned case

This paper delineates the underlying theory of an efficient method for solving a class of specially-structured linear complementarity problems of potentially very large size. We propose a block-iterative method in which the subproblems are linear complementarity problems. Problems of the type considered here arise in the process of making discrete approximations to differential equations in the presence of special side conditions. This problem source is exemplified by the free boundary problem for finite-length journal bearings. Some of the authors' computational experience with the method is presented.
Factors Affecting Perceptions of Procedural Fairness of Downsizing: A Policy Capturing Approach

Subjects read 67 scenarios about downsizing events in which process improvements suggested by HRD researchers were manipulated, and then rated the degree to which the organization was acting in a fair manner. Factors or cues manipulated in scenarios based on HRD practices and literature included (a) whether the victims were given notice and explanation of the layoffs by management, (b) whether the company provided career training and outplacement assistance to victims, (c) whether the layoff decisions were performance-based or based on earnings, (d) whether the company was currently nonprofitable or downsizing because of decrease in profitability, (e) whether the company implemented other HRD strategies before considering downsizing, and (f) the size of the organization. Regression analyses found that a majority of subjects based fairness on (a) whether the downsizing decision was performance-based, (b) whether notice and explanation was given by management, and (c) whether the organization provided career counseling and outplacement assistance. Further, cluster analysis revealed three groups of subjects who utilized cues similarly. Between-group analyses found that levels of cognitive moral reasoning were related to the amount of variance explained by the cues overall and to the beta weights for several cues. Implications for the field of HRD are discussed.
Direct fatty acid profiling of complex lipids in intact algae by fast-atom-bombardment mass spectrometry

Abstract Fast-atom-bombardment mass spectrometry (FABMS) is used for the semiquantitative determination of the fatty acids of complex lipids directly from intact algal cells, crude algal lipid extracts, and vegetable oils. Carboxylate ions, RCOO − , corresponding to the fatty acid moieties of the complex lipids are detected. The relative abundances of the carboxylate fatty acid ions in the FAB mass spectra agreed with the relative percentages found by gas chromatography of the fatty acid methyl esters derived from the extracted lipids. Chemical ionization/fast-atom-bombardment mass spectrometry (CI/FABMS) is discussed with respect to enhancing the molecular ions of the fatty acids and triacylglycerols from these materials. The use of FABMS requires little sample preparation, and FABMS enables rapid fatty acid screening, directly from crude biological materials.
INHALATION EXPOSURE TO VOLATILE CHEMICALS IN DRINKING WATER

Inhalation of volatile chemicals released during household water use is a recognized exposure pathway. Models previously developed to estimate inhalation exposure to radon gas, radon progeny, and volatile organic compounds (VOCs) were limited in their ability to predict exposure to compounds of low volatility due to a lack of appropriate experimental data. Recently, a comprehensive series of experimental studies has been completed in which mass-transfer coefficients for a shower, bath, faucet, washing machine, and dishwasher have been measured, making more detailed and accurate predictions possible. In this paper, the theoretical basis for mass transfer between water and air is reviewed and then extended to include the pH-dependent transfer of volatile compounds that participate in rapid acid/base reactions. This class of compound has not previously been considered in exposure assessment models. The evolution of inhalation exposure models is briefly reviewed and an improved version is developed. Sample ca...