cssi/SciSciGPT-SciSciNet huggingface dataset:
Protein S enhances C4b binding protein interaction with neutrophils

Protein S, an inhibitor of coagulation, interacts reversibly with C4b binding protein (C4bBP). The physiologic role of this complex formation remains unknown. In this study we examined the possibility that protein S would facilitate C4bBP binding to the surface of neutrophils where, in turn, this complex could help protect the cell from complement- mediated damage at the site of inflammation. Neutrophils bind approximately 60,000 protein S molecules per cell (kd = 140 nmol/L) in a Ca(2+)-dependent fashion. C4bBP also binds to neutrophils (23,000 sites per cell at physiologic C4bBP concentration), but this binding is not Ca2+ dependent. Protein S approximately doubled C4bBP binding, but protein S only influenced C4bBP binding in the presence of Ca2+. Protein S binding to neutrophils decreased approximately twofold in the presence of saturating concentrations of C4bBP. Neutrophil activation had only minor effects on the affinity and number of sites for protein S or the protein S-C4bBP complex. These results indicate that the protein S-C4bBP complex binds to the neutrophil surface where it can presumably modulate complement assembly on the cell surface.
Stockholders, Stakeholders, and Bagholders (or How Investor Diversification Affects Fiduciary Duty)

The traditional wisdom is that management should serve the interests of the corporation and the stockholders who own it by maximizing stockholder wealth. But a significant number of legal scholars argue that management duty should be more broadly construed to include other constituencies (stakeholders), such as employees, creditors, customers, suppliers, and the community at large. The broader view of management duty means that management has more discretion and that stockholders will seldom have recourse if management fails to maximize profits. Nevertheless, many states have adopted so-called other constituency statutes permitting management to consider such other interests. The difference between the two views of management duty depends on how one defines a reasonable stockholder. If management duty is measured by the interests of a diversified stockholder, management's duty is to maximize profits even at the risk of bankrupting the firm. If management duty is measured by the interests of an undiversified stockholder, the duty is to maximize profits and to minimize risk. Because rational investors diversify, most commentators have assumed that fiduciary duty should be construed as if owed to a diversified stockholder. The thesis here, however, is that (i) it is impractical to measure fiduciary duty by reference to diversified stockholders because management itself is often a significant undiversified investor in the business, and (ii) diversified stockholders will, in any event, prefer management to behave as if it owes its duty to undiversified stockholders. Thus, in practice, management duty should be seen as owed to the corporation but not necessarily to the stockholders.
Speaking Graffiti: Imaging Human Rights from Belfast to the West Bank:

The human rights conditions of Northern Ireland and Palestine have been analyzed up, down, and sideways by a robust scholarly literature, this article provides a fresh approach to the analysis of m...
Hazardous Connections: Conflictual Ties, Common Intermediary, and Tie Dissolution

Although the positive role of a common third-party organization in the formation and the maintenance of relationships between two organizations is well documented, recent studies reveal that connec...
SU-F-207-12: Optimal CT Scan Mode and Reconstruction Kernel Selection for Bone Fracture Detection Task Under Both Centered and Off-Centered Conditions

Purpose: Hi-Res(olution) mode was introduced in some state-of-the-art CT systems to reduce aliasing and improve spatial resolution. The Hi-Res data can be reconstructed using either the conventional kernels or HD kernels. Since high spatial resolution is often associated with a tremendous increase in image noise, the introduction of Hi-Res has confounded the scan protocol optimization. This work investigated how to use the task-driven optimization framework to optimize the selection of Hi-Res mode and reconstruction kernel for bone fracture detection tasks. Methods: The dependence of spatial resolution on scan mode, reconstruction kernel and off-center position was quantified via MTF measurements. For certain edge enhancing Hi-Res kernels, accuracy of the measurements was confounded by both high image noise and potential CT number saturations. These challenges were addressed by a combined use of repeated scanning and thick-slice reconstructions. Similarly, the NPS was measured under different conditions from repeated scans. The frequency-dependent detectability analysis was used to combine imaging task, MTF, and NPS to quantify the dependence of the overall imaging performance and optimize scan mode and reconstruction kernel selection. Results: (1) For a conventional kernel, the use of Hi-Res significantly improved the MTF at off-centered position. (2) The combined use of Hi-Res mode and HD kernel improved MTF at both the centered and off-centered positions. (3) The use of HD kernels increased noise magnitude and pushed the NPS to higher frequencies, and a model-observer analysis demonstrated that the optimal kernel and scan mode strongly depends on patient position and the nature of the task. This was confirmed by ex vivo animal (bovine bone) experiment. Conclusion: Optimal use of the Hi-Res mode and its associated HD kernels depends on patient positioning and the imaging task. Optimal decision making for its use can be achieved based on the framework developed in this work. J. P. Cruz Bastida, D. Gomez-Cardona, K. Li: Nothing to disclose. T. P. Szczykutowicz: Equipment support, General Electric Company Research Grant, Siemens AG. G.-H. Chen: Research funded, GE Healthcare; Research funded, Siemens AX.
The Pursuit of the Perak Regalia: Islam, Law, and the Politics of Authority in the Colonial State

Islamic law changed radically in the last century and a half. It was codified and limited to the domain of personal and family law in almost all majority and minority Muslim states. The argument of this article is that this remarkable change in Islamic law began in the colonial state. Islamic law, as it functions within postcolonial Muslim states, is a product of negotiations between colonial and local elites over law, religion, culture, ethnicity, and the identity of the Muslim subject. In the case of colonial Malaya, this resulted in a codified, institutionalized legal system within a colonial state, which was critical in constructing Malay ethnic and religious identities and interpretations of Islam that prevail today.
Study on the Microstructure Changes of Hypereutectic Aluminum Casting Alloy Using Ultrasonic Vibration Process

The microstructure changes using the ultrasonic vibration process method and Al-P refiner on permanent mold castings of hypereutectic aluminum alloy (Al-20Si) were studied using optical microscopy. The Al-P refiner refined the primary silicon phase from a large polyhedral shape to a smaller polyhedral shape, but had no effects on the morphology of the eutectic silicon phase. However, in samples subjected to ultrasonic vibration during the solidification process, both primary and eutectic silicon phases were significantly refined and modified respectively. Furthermore, the aluminum phase was also significantly changed. Small polyhedral silicon particles and globular aluminum grains were formed in the region near the probe (zone one). In the region far away from the probe (zone two), the primary silicon refined as in zone one, while the partly eutectic phase changed to globular alpha aluminum phase and polyhedral silicon phase.
Do Changes in the Minimum Wage Impact Obesity in the U.S.

We investigate how changes in federal and state minimum wages affect body mass index and the probability of obesity using data from the 1990 through 2008 waves of the Behavioral Risk Factor Surveillance System. After controlling for unobserved trends at the state level we find that, in contrast to previous work that only accounts for state and year fixed effects, there is a positive relationship between the minimum wage and both mean body mass index and the probability of being obese. Further, we offer the first comprehensive analysis of the price and income components of the minimum wage effect.
Modeling historical and future spatio-temporal relationships of moving objects in databases

Moving object databases have recently found large interest in the data-base community, geographical information systems, and geosciences. So far, moving object models have focused exclusively either on past or future movements. The so-called Balloon Model is the first attempt to treat past and future movements of moving objects in a consistent and integrated manner. Based on a new set of spatio-temporal data types and operations as well as former research, in this paper, we propose a design of spatio-temporal predicates on Balloon objects. These predicates explore the topological relationships of Balloon objects over time and take into account both past and future movements. We present new kinds of queries to demonstrate the use of these predicates.
POST‐POLLINATION PHENOMENA IN ORCHID FLOWERS

Summary Applications of ABA to Cymbidium flowers induce some, but not all, post-pollination symptoms. Anthocyanin levels in sepals, petals, columns and labella are raised; flowers wilt; dorsal sepals become hooded; calli develop colouration while losing turgidity; columns do not swell, lose very little curvature; and stigmas do not close. Combinations of ABA and NAA induce all post-pollination phenomena, but lower anthocyanin content than treatments with ABA only. ABA plus GA3 have effects which are similar to those of ABA alone, except that anthocyanin levels are reduced. The same is essentially true of ABA-kinetin mixtures but intensities of the effects are different and with some concentration ratios, stigmatic closure also occurs. The effects of ABA and its interactions with GA3, kinetin or NAA are explained in terms of the roles these hormones may play in synthesis of nucleic acids and enzymes.
Common problems experienced by adults with osteoarthritis.

Functional status and noncompliance were assessed at baseline in 327 patients with osteoarthritis (OA), 96% of whom were interviewed again later either by telephone or at their next scheduled primary care visit. One-third of the sample reported noncompliance at baseline. During the follow-up interviews, commonly identified problems included having an inadequate supply of medicines to last until their next physician visit (47%), experiencing gastrointestinal complaints (36%), and reporting barriers to primary care (32%). For OA patients with hypertension or heart disease (N = 241), 75% reported clinically important symptoms. Patients with poorer functional status at baseline generally reported more subsequent problems. We conclude that patients frequently have correctable problems (e.g., medication noncompliance and side effects, barriers to care). These patients may be identified prospectively by their poor functional status. Arthritis health care professionals may wish to consider patient-oriented interventions to obviate these problems when evaluating functional status.
Potts model on a fractal lattice

The authors consider the dilute Potts model on the Sierpinski carpet. The model has a phase transition at a finite temperature and both critical and tricritical behaviour are observed for qqc (where q is the number of Potts states). They use Migdal-Kadanoff type recursion relations to obtain the value of qc and of critical and tricritical exponents and investigate their dependence on various geometrical characteristics of the fractal.
Cytoplasmic hydrogen ion diffusion coefficient

The apparent cytoplasmic proton diffusion coefficient was measured using pH electrodes and samples of cytoplasm extracted from the giant neuron of a marine invertebrate. By suddenly changing the pH at one surface of the sample and recording the relaxation of pH within the sample, an apparent diffusion coefficient of 1.4 +/- 0.5 x 10(-6) cm2/s (N = 7) was measured in the acidic or neutral range of pH (6.0–7.2). This value is approximately 5x lower than the diffusion coefficient of the mobile pH buffers (approximately 8 x 10(-6) cm2/s) and approximately 68x lower than the diffusion coefficient of the hydronium ion (93 x 10(-6) cm2/s). A mobile pH buffer (approximately 15% of the buffering power) and an immobile buffer (approximately 85% of the buffering power) could quantitatively account for the results at acidic or neutral pH. At alkaline pH (8.2–8.6), the apparent proton diffusion coefficient increased to 4.1 +/- 0.8 x 10(-6) cm2/s (N = 7). This larger diffusion coefficient at alkaline pH could be explained quantitatively by the enhanced buffering power of the mobile amino acids. Under the conditions of these experiments, it is unlikely that hydroxide movement influences the apparent hydrogen ion diffusion coefficient.
Four New Species of Mexican Castilleja (Subgenus Castilleja, Scrophulariaceae) and Their Relatives

Castilleja subgenusCastilleja in the northern half of Mexico consists of nine species, which are treated here. The subgenus is characterized by a conspicuously colored calyx that is much more deeply cleft in front (abaxially) than in back (adaxially).Castilleja rhizomata,C. linifolia,C. mcvaughii, andC. pterocaulon are described as new, and are illustrated and mapped. The first three are compared toC. patriotica and C.tenuiflora, their closest relatives in the Tenuiflorae group, and the fourth is compared toC. ortegae, with which it constitutes the Ortegae group.Castilleja roei andC. tenuifolia of the Epichroma group are included in order to complete the census of subgenusCastilleja as encountered in the region of the new species. A key to the nine species of subgenusCastilleja from the northern half of Mexico is provided.
A-scalability and an integrated computational technology and framework for non-linear structural dynamics. Part 1: Theoretical developments and parallel formulations

For large-scale problems and large processor counts, the accuracy and efficiency with reduced solution times and attaining optimal parallel scalability of the entire transient duration of the simulation for general non-linear structural dynamics problems poses many computational challenges. For transient analysis, explicit time operators readily inherit algorithmic scalability and consequently enable parallel scalability. However, the key issues concerning parallel simulations via implicit time operators within the framework and encompassing the class of linear multistep methods include the totality of the following considerations to foster the proposed notion of A-scalability: (a) selection of robust scalable optimal time discretized operators that foster stabilized non-linear dynamic implicit computations both in terms of convergence and the number of non-linear iterations for completion of large-scale analysis of the highly non-linear dynamic responses, (b) selecting an appropriate scalable spatial domain decomposition method for solving the resulting linearized system of equations during the implicit phase of the non-linear computations, (c) scalable implementation models and solver technology for the interface and coarse problems for attaining parallel scalability of the computations, and (d) scalable parallel graph partitioning techniques. These latter issues related to parallel implicit formulations are of interest and focus in this paper. The former involving parallel explicit formulations are also a natural subset of the present framework and have been addressed previously in Reference 1 (Advances in Engineering Software 2000; 31: 639–647). In the present context, of the key issues, although a particular aspect or a solver as related to the spatial domain decomposition may be designed to be numerically scalable, the totality of the aforementioned issues simultaneously play an important and integral role to attain A-scalability of the parallel formulations for the entire transient duration of the simulation and is desirable for transient problems. As such, the theoretical developments of the parallel formulations are first detailed in Part 1 of this paper, and the subsequent practical applications and performance results of general non-linear structural dynamics problems are described in Part 2 of this paper to foster the proposed notion of A-scalability. Copyright © 2003 John Wiley & Sons, Ltd.
Presynaptic dopamine receptors as mediators of dopamine-induced inhibition of neurogenic vasoconstriction

Abstract I.v. infusion of dopamine (10 μg/kg/min) caused significant attenuation of renal vasoconstrictor responses to sympathetic nerve stimulation in pentobarbital-anesthetized dogs, whereas renal vasoconstrictor responses to exogenously administered norepinephrine were unaffected. Desipramine treatment significantly potentiated the inhibitory effect of dopamine on neurogenic vasoconstriction. Pretreatment with pimozide, a dopamine receptor blocking agent, prevented the inhibitory influence of dopamine on renal sympathetic nerve function. These results demonstrate that dopamine can inhibit neurogenic vasoconstriction by activating presynaptic dopamine receptors present on renal sympathetic nerves.
Structure of the ammonia dimer studied by density functional theory

Self-consistent Kohn–Sham density functional calculations have been carried out to study the structure of the ammonia dimer. The local-density approximation yields unusually large binding energy and short internitrogen distance compared with the experimental and more accurate theoretical data. The results from the Becke–Perdew gradient-corrected functionals are generally in good agreement with those at the SCFMP2 level when the geometry is fully optimized with various large basis sets. With our best estimation, the staggered quasi-linear structure (Cs) is 0.6 kcal/mol lower in energy than the symmetric cyclic one (C2h). The hydrogen-bonded N—H bond in the staggered quasi-linear structure is found to be 0.008 A longer than the N—H bond in ammonia. In our calculations, we could not find the minima on the energy surface corresponding to the two asymmetric cyclic structures suggested by microwave spectra and coupled pair functional calculations. © 1994 John Wiley & Sons, Inc.
Yield Responses of Alfalfa to Simulated Alfalfa Weevil Injury and Development of Economic Injury Levels

Although the alfalfa weevil Hypera postica (Gyllenhal)] is an important alfalfa (Medicago sativa L.) pest, relatively little is known about how defoliation at specific plant developmental stages affects yield. This study was conducted to characterize yield responses of alfalfa to simulated alfalfa weevil injury when injury was initiated at the early hud stage of the first growth cycle and to develop economic injury levels for the alfalfa weevil. The study was conducted on a silty clay loam (fine, montmorillonitic, mesic Typic Argiudoll) in a 3.6-ha alfalfa (cv. Haymaker) field near Walton, NE [...]
Cloning and Characterization of the Ravidomycin and Chrysomycin Biosynthetic Gene Clusters

The gene clusters responsible for the biosynthesis of two antitumor antibiotics, ravidomycin and chrysomycin, have been cloned from Streptomyces ravidus and Streptomyces albaduncus, respectively. Sequencing of the 33.28 kb DNA region of the cosmid cosRav32 and the 34.65 kb DNA region of cosChry1-1 and cosChryF2 revealed 36 and 35 open reading frames (ORFs), respectively, harboring tandem sets of type II polyketide synthase (PKS) genes, D-ravidosamine and D-virenose biosynthetic genes, post-PKS tailoring genes, regulatory genes, and genes of unknown function. The isolated ravidomycin gene cluster was confirmed to be involved in ravidomycin biosynthesis through the production of a new analogue of ravidomycin along with anticipated pathway intermediates and biosynthetic shunt products upon heterologous expression of the cosmid, cosRav32, in Streptomyces lividans TK24. The identity of the cluster was further verified through cross complementation of gilvocarcin V (GV) mutants. Similarly, the chrysomycin gene cluster was demonstrated to be indirectly involved in chrysomycin biosynthesis through cross-complementation of gilvocarcin mutants deficient in the oxygenases GilOII, GilOIII, and GilOIV with the respective chrysomycin monooxygenase homologues. The ravidomycin glycosyltransferase (RavGT) appears to be able to transfer both amino- and neutral sugars, exemplified through the structurally distinct 6-membered D-ravidosamine and 5-membered D-fucofuranose, to the coumarin-based polyketide derived backbone. These results expand the library of biosynthetic genes involved in the biosyntheses of gilvocarcin class compounds that can be used to generate novel analogues through combinatorial biosynthesis.
Critical properties of viscoelasticity of gels and elastic percolation networks.

Two superelastic percolation models are proposed to explain the observed behavior of the viscosity \ensuremath{\eta} of gels near the gel point. The elastic moduli G of one model diverge at the percolation threshold ${\mathit{p}}_{\mathit{c}}$ with a critical exponent \ensuremath{\tau} given by \ensuremath{\tau}=\ensuremath{\nu}-${\mathrm{\ensuremath{\beta}}}_{\mathit{p}}$/2, where \ensuremath{\nu} and ${\mathrm{\ensuremath{\beta}}}_{\mathit{p}}$ are the critical exponents of percolation correlation length and the strength of the infinite cluster, respectively. We propose that this system can model the behavior of \ensuremath{\eta} in the Zimm limit. In the second model, which we propose to be appropriate for the Rouse limit, G diverge at ${\mathit{p}}_{\mathit{c}}$ with an exponent \ensuremath{\tau}'=2\ensuremath{\tau}. Large-scale simulations confirm these scaling laws. The experimentally observed deviations from these scaling laws are also discussed.
Structurally Ordered FePt Nanoparticles and Their Enhanced Catalysis for Oxygen Reduction Reaction

We report the structure-controlled synthesis of FePt/MgO NPs and their catalysis for oxygen reduction reaction (ORR) in 0.5 M H(2)SO(4) solution. The synthesis yields fcc-FePt/MgO and fct-FePt/MgO NPs with the MgO coating being readily removed for catalytic studies. The fct-FePt NPs show higher activity and durability than the fcc-FePt in the ORR condition. The results indicate that the fully ordered fct-FePt could serve as a practical Pt-based catalyst for fuel cell applications.
Cloning and expression of the human myeloid cell nuclear differentiation antigen: Regulation by interferon α

The human myeloid cell nuclear differentiation antigen (MNDA) is a protein of 406 amino acids that is expressed specifically in granulocytes, monocytes and earlier stage cells of these lineages. Degenerate oligonucleotides that could encode regions of MNDA amino acid sequence were used to amplify the MNDA cDNA sequence using the polymerase chain reaction. The amplified cDNA product was sequenced to confirm that it encoded the MNDA protein. It was then used as a probe to isolate five clones from a human bone marrow lambda gt10 cDNA library. A clone containing a 1,672 base pair cDNA insert was sequenced and found to encode the entire MNDA open reading frame, as well as 5' and 3' untranslated regions. The primary structure of the MNDA contains extensive regions of sequence similarity with the protein products of the interferon-inducible genes: 204 and interferon regulatory factor 2. In addition, a 12-base sequence matching the interferon-stimulated response element consensus sequence [GAAAN(N)GAAA] is located in the 5' untranslated region of the MNDA cDNA. The 1.8 kb MNDA mRNA was detected only in cells that express the antigen and the level of MNDA mRNA was elevated in cells treated with either recombinant or natural interferon alpha. The MNDA mRNA was not induced by interferon alpha in cells that do not exhibit a constitutive level of the MNDA mRNA. The MNDA contains sequence motifs found in gene regulatory proteins. The expression and the primary structure of the MNDA indicates that it plays a role in the granulocyte/monocyte cell-specific response to interferon.
Universal model for the surface energy of solids

The surface energy $\ensuremath{\sigma}$ is considered as the work done in reversibly cleaving a bulk solid. Let $F(z)$ be the force per unit area required to increase the spacing between the end planes from $a$ to $a+z$. For small $z$, $F(z)=Az$, where we show how $A$ can be determined from the bulk phonon spectrum, and for large $z$, $F(z)=\frac{C}{{z}^{3}}$, where $C$ can be determined from the bulk frequency-dependent dielectric constant. We assume that, apart from scale, the function $F(z)$ has a universal shape ${f}^{*}(z)$. It then follows that $\ensuremath{\sigma}={\ensuremath{\alpha}}^{*}{(\mathrm{AC})}^{\frac{1}{2}}$ where ${\ensuremath{\alpha}}^{*}$ is a universal constant. Preliminary comparison with experiment gives good results with ${\ensuremath{\alpha}}^{*}=0.476$.
Novel peptides secreted from human neuroblastoma: useful clinical tools?

Abstract Background Differentially expressed neuroblastoma (NB) proteins are vital for the development of new diagnostics and therapeutics. For example, secretory NB peptides (neuron-specific enolase and chromogranins) are clinically useful. We investigated polypeptide secretion by employing proteomic technologies to analyze proteins released from cultured NB cells. Methods Neuroblastoma cell lines (SK-N-AS, SK-N-DZ, and SK-N-FI) were grown in serum-free media. Conditioned media from each cell line was analyzed for secreted proteins by 2-dimensional polyacrylamide gel electrophoresis. Selected polypeptides were identified by liquid chromatography–linked tandem mass spectrometry. Results We identified 5 polypeptides that were secreted or shed by NB. Ubiquitin, β 2 -microglobulin, insulin-like growth factor binding protein–2, superoxide dismutase (copper and zinc), and heat shock cognate 70-kd proteins were secreted from NB cells, as compared with control media. Elevated levels of these proteins have been described in serum/tissues under intracellular stress and malignancies, including NB. Conclusion These novel secretory polypeptides may contribute to NB growth. The proteins may reveal additional tumor markers and permit putative use in the diagnosis and treatment of NB. Detection of these proteins in serum of children with NB vs controls (using 2-dimensional polyacrylamide gel electrophoresis and mass spectrometry techniques) is currently in progress.
Competition between antiferromagnetic order and spin-liquid behavior in the two-dimensional periodic Anderson model at half filling.

We study the two-dimensional periodic Anderson model at half filling using quantum Monte Carlo (QMC) techniques. The ground state undergoes a magnetic order-disorder transition as a function of the effective exchange coupling between the conduction and localized bands. Low-lying spin and charge excitations are determined using the maximum entropy method to analytically continue the QMC data. At finite temperature we find a competition between the Kondo effect and antiferromagnetic order which develops in the localized band through Ruderman-Kittel-Kasuya-Yosida interactions.
Wet and dry deep cavity preparations compared by a novel odontoblast culture technique.

The human odontoblast’s unique cellular extension within dentin does not easily allow culturing by traditional methods. This study leaves these cells in their natural position in the dentin. Deep preparations were made through the occlusal surfaces of extracted human third molars. The crowns were separated from the roots and the pulps gently teased from the chambers, leaving the odontoblast layer intact. These inverted pulp chambers were then incubated in cell culture medium for 2 to 4 days. Trypan blue staining was used to detect nonvital odontoblasts, and the differentiation between vital and nonvital cells was verified by SEM and toluidine vital staining. Control teeth and areas not adjacent to the preparation showed no blue staining, indicating intact cells. Areas of nonvital cells were greatest with wider preparation. Irrigation decreased odontoblast death with wide preparations. No difference due to irrigation was detected in narrow preps. A comparison of wet preparations to which heat was applied versus dry preparations showed statistically similar results. This study provides a simple in vitro method for the study of odontoblasts with their processes intact within dentin.
Correlates of Turbulent Noise Production for Speech

Intraoral air pressure, volume rate of airflow, and sound pressure level were measured during /∫/ and /s/ productions of two speakers. In addition numerical estimates of the loudness of the product...
Molecular Mechanotransduction in Human CD4

HIV-1 infection initiates when the viral envelope glycoprotein gp120 interacts with two receptors on the surface of the T lymphocytes, CD4 and a chemokine co-receptor (CCR5 or CXCR4). Upon binding, a cascade of conformational changes in CD4 triggers viral fusion to the cell membrane. However, the key factors that originate the structural alterations in CD4 are unclear. Here, we use single-molecule force spectroscopy to study the mechanochemical properties of the two more external domains of human CD4 (D1 and D2). The application of mechanical forces to the CD4 domains reveals that they can be unfolded in a time-dependent manner within a biological range of forces. Similarly to other tandem repeats proteins such as titin or tenascin, mechanical unfolding of CD4 modules might be an important process occurring in vivo acting as a shock absorber. This phenomenon would help to prevent viral detachment. Furthermore, we show that mechanical exposition of internal disulfide bonds in CD4 is required for redox regulation by thioredoxin enzymes, a process that has been suggested to occur during viral infection. In addition, we perform numerical calculations using suitable models for polymer elasticity to correlate viral infectivity (Freeman et al. Structure 18(12):163241) with mechanical extensibility of CD4 modules. The role of mechanical forces in HIV-1 infection is yet to be considered, but it might represent a new view to better understand viral infection.
A Comment on the Aries Observations

Dr Swallow’s observations of the vertical profile of currents show how different a view of the deep ocean is now emerging. The tendency of currents to increase with depth below the permanent thermocline is so striking that it seems timely to point out that just this possibility was suggested recently by linearized theory (Rhines 1970). The work showed how short, yet quasi geostrophic, Rossby-topographic waves have a dominant mode that ceases to be independent of depth, and instead has faster currents near the bottom, due to the combined action of rotation, stratification and bottom slopes. This comment is not the first (nor probably the last) application of linear theory to such observations, for both Longuet-Higgins (1965) and Phillips (1966) have suggested their interpretation as Rossby waves of a constant-depth ocean model. Noting this vertical shear, Phillips was forced to invoke a mixture of the familiar baroclinic and barotropic modes. There are, however, objections to this, since those baroclinic modes are exceedingly slowly propagating, and cannot be expected to persist with such strong currents. Also, as Dr Swallow points out, the current directions do not vary greatly in the vertical, suggesting an explanation as a single mode rather than a mixture. The bottom slopes, however, can greatly alter both horizontal propagation and vertical stucture. In particular the presence of vertical shear no longer implies impossibly small frequencies.
Heifer growth and fermentation analyses of tylosin-preserved hay-crop silage.

Abstract Six alfalfa silages preserved with tylosin (2.2 or 11.0 mg/kg) were compared with six control silages over a 3-yr period involving feeding trials with 100 heifers fed only silage and minerals. Tylosin preservation inhibited secondary fermentation of lactic acid to acetic acid and increased the average daily gain with three of the six paired silages. In two failures there were only small depressions in gain associated with tylosin preservation and, in the other case of depression, the silage had been inoculated with a tylosin-resistant culture. Excluding this inoculated silage, tylosin preservation increased gains 17%.
Spatial Diffusion of Management Practices in Urban and Rural Areas

Data on production and management practices across firms are scarce.Therefore studies of rural and urban industrial development have usually abstracted from this issue or have invoked product cycle theory to explain comparative urban and rural productive ingenuity. Several qualitative studies of rural production have contradicted the product cycle hypotheses, but attempts to generalize these results have not succeeded. An attempt is made here to test the product cycle explanation of industrial location using the registry of firms with ISO 9000 certification in nine southern states. These data suggest a bifurcation of rural counties. Urban and rural counties containing certified firms have been much more likely to increase the number of such firms, but in those counties without certified firms the probability of new certified firms has declined
Biophysical Analysis of a Novel Drug Delivery Vector: ELP[V5G3A2-150]

Elastin-like Polypeptides (ELPs) are genetically engineered biopolymers that are derived from the endogenous protein Tropoelastin. ELPs are structurally disordered and soluble at low temperatures but transition to a β-spiral and aggregate at a Transition Temperature (TT). This aggregation is being explored as a novel drug delivery vector by thermally targeting systemically delivered ELP-drug conjugates. We are investigating the biophysical properties of ELP[V5G3A2-150] as a means of understanding and predicting the behavior in vivo. We have investigated the hydrodynamic, structural and thermodynamic properties of ELP[V5G3A2-150] through the use of CD, turbidity, DLS, DSC and SV. DLS and SV analyses suggest that ELP[V5G3A2-150] experiences small amounts of weak association below the TT that increase with temperature. CD analyses further indicate that below the TT ELP[V5G3A2-150] consists of both disordered (≈75%) and β-conformation (≈25%) and as the temperature and concentration is increased the % β-conformation increases. The temperature & concentration dependence of β-conformation suggests that the weak association can be attributed to heterogeneous β-sheets. SV revealed that above the TT ELP[V5G3A2-150] exhibits a temperature dependent critical concentration (CC). This CC is consistent with the TT and suggests that the TT may be described as a solubility constant.Assembly in serum raises the TT by ≈ 2.5°C. This is opposite to the expected effect of macromolecular crowding and suggests that certain serum proteins may be associating with ELP[V5G3A2-150]. Investigation of this effect through SV was greatly complicated by the presence of the Johnston-Ogston (J-O) effect. Further investigation suggested additional complexity in systems exhibiting the J-O effect than previously reported. Two of the additional complexities already determined are cross-term hydrodynamic non-ideality and high-concentration convection. Additional research into the effects of attaching CPPs to ELP[V5G3A2-150] will be presented. Work supported by NSF ARRA 0959211 grant.
Legume cyclotides shed light on the genetic origin of knotted circular proteins

Cyclotides are fascinating circular proteins ranging from 28 to 37 aa residues that are naturally expressed in plants. They exhibit antimicrobial, insecticidal, antihelmintic, cytotoxic, and antiviral activities (1), and protease inhibitory activity (2), and can exert uterotonic effects (3). They all share a unique head-to-tail circular knotted topology of three disulfide bridges, with one disulfide bond penetrating through a macrocycle formed by the other two disulfides bonds and interconnecting peptide backbones, forming what is called a cystine knot topology (Fig. 1) (1). This cyclic cystine knot framework gives cyclotides a compact, highly rigid structure (4), which confers exceptional resistance to thermal/chemical denaturation and enzymatic degradation (5), thereby making cyclotides a promising molecular scaffold for drug discovery (6, 7). So far, cyclotides have been discovered in plants from the Rubiaceae (coffee), Violaceae (violet), and Cucurbitaceae (squash) families (8, 9), and more recently in the Fabaceae (legume) family (Fig. 1) (10). The discovery of cyclotides in the Fabaceae family of plants represents an important new development because this family of plants is the third largest on Earth, comprising approximately 18,000 different species. Some of these species are widely used as crops in human nutrition and food supply. This opens the intriguing possibility of using these plants for the large-scale production of cyclotides with pharmaceutical or agrochemical properties by using transgenic crops. The key to accomplishing that, however, is to have a better understanding of the mechanism that produces these interesting microproteins in this family of plants.
Activation of Mauthner neurons during prey capture

The Mauthner (M-) cells, a bilateral pair of medullary neurons in fish, initiate the characteristic “C-start” predatory escape response of teleosts. Similar movements have been described during hatching, social interactions, and feeding. M-cell firing, however, has not been correlated directly with these other behaviors. The objective of this study was to determine whether the M-cell, in addition to escape, plays a role in feeding. 1. Goldfish were chronically implanted with electrodes positioned near the axon cap of one of the two M-cells. Subsequently, M-cell activity was monitored for up to 8 days while fish were surface feeding on live crickets. 2. The M-cell fires and the fish performs a C-shaped flexion in association with the terminal phase of prey capture. Thus, the M-cell is active in the context of at least two behaviors, predator escape and prey capture, and may be considered a part of behaviorally shared neural circuitry. 3. For the goldfish, Mauthner-initiated flexions during feeding rapidly remove the prey from the water's surface and minimizes the fish's own susceptibility to surface predation. Other species may possess a diverse repertoire of Mauthner-mediated feeding behaviors that depend on their adaptive specializations for predation. Moreover, group competition between predators and their prey may have facilitated a “neural arms race” for M-cell morphology and physiology.
All's well that begins Wells: Celebrating 60 years of Animal Behaviour and 36 years of research on anuran social behaviour

The scientific study of frogs and toads as important systems in behavioural ecology traces its roots to an influential review published in this journal 36 years ago ( Wells 1977a , ‘The social behaviour of anuran amphibians’, Animal Behaviour, 25, 666–693). In just 28 pages, Wells summarized the state of knowledge on important behaviours associated with anuran breeding and introduced an evolutionary framework ‘for understanding the relationship between social behaviour and ecology’ (page 666) that was largely lacking in earlier treatments of this group. Not only is Wells's review one of the most cited papers ever published in Animal Behaviour, it is also responsible for setting broad research agendas and shaping much of our current thinking on social behaviour in an entire order of vertebrates. As such, it is entirely appropriate that we honour Wells's review and its contributions to the study of animal behaviour in this inaugural essay celebrating 12 papers selected by the community as the most influential papers published in the 60-year history of Animal Behaviour. In our essay, we place Wells's review in historical context at the dawn of behavioural ecology, highlight the field's progress in answering some major research questions outlined in the review, and provide our own prospectus for future research on the social behaviour of anuran amphibians.
Facilitated stimulus-response associative learning and long-term memory in mice lacking the NTAN1 amidase of the N-end rule pathway

Abstract The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. Inactivation of the NTAN1 gene encoding the asparagine-specific N-terminal amidase in mice results in impaired spatial memory [26] . The studies described here were designed to further characterize the effects upon learning and memory of inactivating the NTAN1 gene. NTAN1-deficient mice were found to be better than wild-type mice on black–white and horizontal–vertical discrimination learning. They were also better at 8-week Morris maze retention testing when a reversal trial was not included in the testing procedures. In all three tasks NTAN1-deficient mice appeared to use a strong win–stay strategy. It is concluded that inactivating the asparagine-specific branch of the N-end rule pathway in mice results in impaired spatial learning with concomitant compensatory restructuring of the nervous system in favor of non-spatial (stimulus-response) learning.
5' Guanylyl-imidodiphosphate actions on adenylate cyclase in homogenates of rat cerebral cortex plus neuronal and capillary fractions.

Abstract A variety of neurohumoral agents activate adenylate cyclase in homogenates of rat frontal cortex (norepinephrine, isoproterenol, dopamine, apomorphine, histamine, 4-Me-histamine and prostaglandins E 1 , E 2 and A 2 ). The enzyme in homogenates of isolated cortical neurons is likewise sensitive to norepinephrine, isoproterenol, dopamine, apomorphine, histamine, 2-Me- and 4-Me-histamine, and prostaglandin F 2α . Capillary-enriched fractions from the cortex possess an enzyme that is activated by norepinephrine, isoproterenol and dopamine. Addition of 5′-guanylyl-imidodiphosphate (Gpp(NH)p) to the cortical homogenates and neuronal fractions resulted in enhanced enzyme responses to norepinephrine, isoproterenol, dopamine, 2-Me- and 4-Me-histamine and the prostaglandins E 1 and E 2 . The actions of histamine and apomorphine were not increased by the GTP analog. The sensitivity of the catecholamine-induced adenylate cyclase activation in cortical capillaries was augmented by Gpp(NH)p. Thus various cellular types within the cerebral cortex may possess different receptor characteristics with respect to stimulation of adenylate cyclase by neurohormones.
Correlations Between Forest Layers in the Swan Valley, Montana

Compositional patterns of forest layers (tree, shrub, herb, bryoid, and epiphyte) are weakly correlated in the Swan Valley. While one can roughly predict the composition of one layer based upon the composition of another layer, different strata do not change composition across environmental gradients at the same rate or in the same pattern. The relative position of two or more stands in species space is different for different layers. Evidence in support of this conclusion was derived from: (1) correlation of dissimilarity matrices, (2) correlation of stand placement on ordination axes, and (3) comparison of stand groups defined by cluster analysis. See full-text article at JSTOR
Sleep Hygiene Practices and Bedtime Resistance in Low-Income Preschoolers: Does Temperament Matter?

This study examined sleep hygiene practices and bedtime resistance and tested whether associations differed by child temperament. Parents of Head Start preschoolers (n = 374, 56% non-Hispanic white) completed the Going to Bed subscale of the Children's Sleep-Wake Scale (GTB; higher score reflects less bedtime resistance), Children's Sleep Hygiene Scale (CSHS; higher score reflects better sleep hygiene), and Child Behavior Questionnaire (Anger, Activity, Impulsivity subscales indicated difficult temperament). Monte Carlo simulation adjusted for demographic covariates tested associations of CSHS with GTB in children with more- vs. less-difficult temperaments. Children with more- vs. less-difficult temperaments experienced worse sleep hygiene (p < .0001) and had more bedtime resistance (p < .0001). Among children with more difficult temperaments, better sleep hygiene was linearly associated with less bedtime resistance (β = 1.28, 95% CI 0.77, 1.78). Among children with less difficult temperaments, the associ...
The Medical School Admission Interview: Perspectives on Preparation.

The admission interview is the primary means that medical schools use to determine whether applicants possess the personal characteristics suitable for medical practice. In preparation for the interview, prospective students should be able to explain why they chose medicine as a profession and relate experiences that helped them confirm their interests. They should be aware of the economic and ethical atmosphere in which medicine is practiced and should recognize challenges that this environment presents to the profession. Applicants should display good communication skills in their interactions with the interviewers and convey interest in, familiarity with, and enthusiasm about the school where they are interviewing.
Rhetoric and political process in the Hill‐Thomas hearings

The Senate Judiciary Committee hearings on Clarence Thomas' nomination to the Supreme Court in October 1991 provided Thomas and other Americans with something to criticize: the political process. At a time when the Judiciary Committee and the nation might have focused on the general issue of sexual harassment and the specific issue of whether Professor Anita Hill was harassed by Clarence Thomas, proceduralist rhetoric served to divert attention elsewhere. The process proved a convenient object for criticism; it functioned as scapegoat for American frustration.
Halogen NQR spectroscopy in nonahalodiantimonate(III) ions, Sb2X93−, and it's implications regarding the “inert pair effect”

Abstract Bromine NQR spectra in Sb 2 Br 9 3− salts of CH 3 NH 3 + and iodine data in the Sb 2 I 9 3− salt of CH 3 NH 3 + are reported. There clearly exists two sets of resonance frequencies assignable to bridged and terminal halogen atoms. The results are best understood in terms of distortion of the Sb(III) kernal to increase electron density in the region of the bridging halogen atoms. Iodine data in Sb 2 I 9 3− suggest that the bridged halogen asymmetry parameter is quite large.
Modeling of radio-frequency effects on a microcontroller

The ability to understand and predict the effects on electronic systems that might result from an intentional EMI attack is crucial to defending critical electronic systems against such a threat. To address this need we are building a predictive model for effects on digital electronics, based on combining electromagnetic coupling models with an investigation of the response of electronics at the device, circuit and system level. As a critical part of this work we have focused our research on understanding and predicting the response of a microcontroller to a high-power electromagnetic waveform. Our approach is to expose the microcontroller to electromagnetic pulses with carefully controlled onset times and durations, while making use of software implemented in assembly language to exercise various functional areas and hence various physical regions of the microcontroller, with the aim of developing fundamental insight into the upset mechanism. In this paper we address how the effect of an electromagnetic pulse on a specific microcontroller varies with pulse duration. In particular we explore how the system responds to two pulses injected at various times while the microcontroller is executing a specified instruction, and investigate the question of when these pulses may be considered as independent events. We present the results from our experiments, as well as summarizing some of our recent work aimed at building a general predictive model.