cssi/SciSciGPT-SciSciNet huggingface dataset:
Phase equilibria and solidification in Ti-Al alloys

High temperature phase equilibria and microstructure evolution during solidification were investigated for Ti-Al alloys in the range 40–55 at.%Al. In situ high temperature X-ray diffraction was used to study the phases present at elevated temperatures. It was found that a hexagonal close-packed α-phase exists close to the melting point for alloys containing 46–50 at.%Al, while leaner alloys (<44%Al) are in a cubic β-phase field at similar temperatures. Examination of dendritic morphologies in arc-button shrinkage cavities revealed the crystallography of the primary solidification phase. These observations were coupled to TEM analysis of the final microstructures to deduce phase sequencing during solidification and solid-state transformations. For alloys in the range 40–49 at. %Al, β was found to be the primary phase in local equilibrium with the liquid, and from 49 to 55 at.%Al, the primary phase was a. α. γ-segregate was first observed at 46 at.%Al and its fraction increased with Al content. Both β and α dendrites transformed in the solid-state to a lath structure consisting of layers of α2 and γ. The γ-segregate did not transform further. A revised phase diagram is proposed, for the composition range studied, incorporating two peritectics L + β → α, and L + α → γ, together with a high temperature α-phase field.
Nigericin and hexylamine effects on localized proton gradients in thylakoids

Low concentrations of nigericin and amines such as hexylamine have been suggested to convert chloroplast thylakoid membrane localized proton gradients to a delocalized mode by transferring H + ions into the lumen (De Kouchkovsky, Y. et al. (1986) VII Int. Congr. Photosynth. III, 169). Experiments to test that hypothesis have been done using two assay systems that provide robust indicators of a shift from localized to delocalized energy coupling. Thylakoids stored in low salt medium normally show localized coupling (lumen pH remains considerably more alkaline than the p K a of pyridine (5.44) in both assays and storage in high salt medium yields a delocalized coupling pattern (lumen pH drops to values close to the p K a of pyridine). Therefore, applying those assays to low-salt-stored thylakoids, with and without nigericin or hexylamine, provided the test for whether those compounds caused delocalization of the H + gradient. The assays were: (A) the effect of pyridine (a membrane-permeable buffer) on the ATP formation onset lag in flashing light; (B) permeable buffer (pyridine or hydroxyethylmorpholine) effects on H + uptake into the lumen in steady illumination under coupled compared to basal conditions. By both criteria, it was found that 1–3 nM nigericin caused much more acidification of the lumen compared to the control (absence of nigericin) in low-salt-stored thylakoids. The apparent delocalization of domain H + gradients into the lumen occurred at nigericin concentrations noted by earlier work to cause stimulation of both electron transport and ATP formation (Giersch, G. (1983) Biochim. Biophys. Acta 725, 309–319). In contrast, hexylamine at 50–100 μM did not cause acidification of the lumen, although it clearly had perturbing effects on the membrane domain metastable H + pool. At hexylamine concentrations less than 100 μM there may be transfer of protonated hexylamine into the lumen, although we could not detect it. The high p K a (10.2) of hexylamine would keep the amine in the protonated form and not contribute to lumen acidification.
Growth retardation and reduced growth hormone secretion in a boy with achalasia

A 15-year-old boy with achalasia of the oesophagus is described in whom growth retardation was the presenting and misleading symptom. Growth hormone (GH) and insulin-like growth factor-I secretion were decreased but GH therapy was unsuccessful. After pneumatic dilatation of the oesophageal sphincter catch up growth occurred.
Stereospecific Polymerization of Chiral Oxazolidinone-Functionalized Alkenes

Acryloyl and vinyl monomers functionalized with a chiral oxazolidinone auxiliary have been successfully polymerized in a stereospecific fashion to highly isotactic, optically active polymers, through either the previously established isospecific coordination polymerization (for acryloyl monomers) or a novel isospecific cationic polymerization (for vinyl monomers). Specifically, conjugated chiral acryloyloxazolidinones, N-acryloyl-(R or S)-4-phenyl-2-oxazolidinone [(R or S)-AOZ], are readily polymerized by chiral ansa-zirconocenium coordination catalysts, (R,R-, S,S-, or R,R/S,S)-[C2H4(η5-Ind)2]Zr+(THF)[OC(OiPr)═CMe2][MeB(C6F5)3]− (1), in an isospecific manner through a catalyst-site-controlled mechanism, producing the corresponding optically active chiral polymers, (R or S)-PAOZ. Owing to the nature of stereocontrol dictated by the chiral catalyst site, even the coordination polymerization of the parent AOZ, without the chiral side group, also affords PAOZ with nearly quantitative isotacticity. A series o...
A theory of the organization of state and local government employees

Expansion of public employee labor organizations has brought considerable change in a sector previously considered outside the domain of the trade union movement. A model to explain this phenomenon among state and local government employees is developed and tested using data from the1977 Census of Governments. The percentage of employees organized is determined by a number of factors which affect the costs and benefits of membership and may be influenced by the level of employees’ earnings. Empirical evidence indicates that a higher level of organization is a product of government size, legal provisions, unionization in the private sector, and, in some government functions, the unemployment rate, and level of income.
UDP-glucose pyrophosphorylase synthesis in myxamoebae of Dictyostelium Discoideum

Abstract A mixture of [14C] amino acids and [35S] methionine are rapidly incorporated into the UDP-glucose pyrophosphorylase of myxamoebae of the cellular slime mold over a period of differentiatin in which a significant change in the amount of enzyme does not occur. There is no evidence for a change in the rate of enzyme synthesis prior to or during the initiation of enzyme accumulation. Therefore, there is no evidence for the involvement of specific periods of transcription or translation in controlling the synthesis of this enzyme prior to or during differentiation.
Differential responses of a mine tailings Pseudomonas isolate to cadmium and lead exposures

We examined cadmium and lead resistance in Pseudomonas sp. S8A, an isolate obtained from mine tailings-contaminated soil. Resistant to soluble metal concentrations up to 200 mg l−1 cadmium and 300 mg l−1 lead, S8A produced both exopolymer and biosurfactant. Upon growth, this pseudomonad diverged into two morphologically distinct colony subtypes; small and round or large and flat. In the presence of lead and in the no metal control the large morphotype appeared only in late stationary phase. With cadmium the large morphotype appeared immediately following exposure. Results show that the large morphotype produced greater amounts of surfactant than the small morphotype, suggesting a unique subpopulation response to cadmium toxicity. Results also indicate that an unidentified 28 kDa protein was expressed following exposure to >10 mg l−1 cadmium. This study demonstrates new links between surfactant production, differential subpopulation response and metal exposure.
Concerns of college students regarding business ethics: A replication

In 1984 we reported the results of surveying a nationwide sample of college students about selected business ethics issues. We concluded that (a) college students were in general concerned about the issues investigated and (b) female students were relatively more concerned than were male students. The present study replicated our earlier study and not only corroborated both of its conclusions, but also found a higher level of concern than had been observed previously.
Using Objective Structured Clinical Evaluation for Simulation Evaluation: Checklist Considerations for Interrater Reliability

Abstract Background Reliability of simulation outcome measurements is infrequently reported in nursing education. The purpose of this study was to establish interrater reliability of a checklist for a pediatric medication administration objective structured clinical evaluation. Method Two raters scored 207 videotaped nursing student objective structured clinical evaluation performances using a 14-item checklist. Item interrater reliability statistics were calculated. Results Adequate interrater reliability was obtained on six items from the cognitive and psychomotor domains of learning. Unacceptable interrater reliability was obtained on four items from the affective domain. Conclusion Results verified the difficulty of quantitatively measuring affective domain behaviors and the need for consistency in rater roles.
Cigarette ash as a possible source of environmental contamination

Abstract The ash remaining from machine smoking of 12 different American cigarette brands has been examined by instrumental neutron activation analysis. The mean concentrations are (element concentration in μg g−1): Al 6070; Ba 375; Br 420; Ca 161 500; Ce 11·1; Cl 23 000; Co 3·58; Cr 21·2; Cs 0·653; Eu 0·154; Fe 3040; Hf 1·33; K 151 000; La 10·3; Mg 12 800; Mn 1250; Na 3460; Ni 24·7; Rb 82·1; Sb 0·741; Sc 0·894; Se 0·361; Sr 373; Th 1·06; Ti 1910; V 11·1; and Zn 221. Arsenic was not detected in all the samples examined. The chemical composition of cigarette wrapping paper has been found to affect the elemental concentration in the ash examined. The possible source of the elements of interest in cigarette ash is discussed and the results are compared with the literature values.
Critical role for Nef in HIV-1–induced podocyte dedifferentiation

Critical role for Nef in HIV-1–induced podocyte dedifferentiation. The notable glomerular feature of human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is the collapse of the capillary tuft with marked glomerular epithelial cell hyperplasia. These data suggest a loss of normal podocyte function, which is associated with a loss of the podocyte differentiation markers, Wilm's tumor (WT-1), synaptopodin, podocalyxin, and common acute lymphoblastic leukemia antigen (CALLA). We have previously shown that HIV-1 expression can induce these changes in HIV-1 transgenic mice. To identify which HIV-1 gene product(s) are responsible for the phenotypic changes in podocytes, we created multiple mutated HIV-1 constructs and then pseudotyped them with vesticular stomatitis virus glycoprotein (VSVG) envelope to enhance the tropism of these mutant viruses. In addition to gag/pol, the mutant viruses lacked one of the following, env, nef, rev, vif, vpr, or vpu. In addition, we generated single gene expressing pseudotyped viruses to complement the scanning mutation approach of our viral parental construct. Murine podocytes were then infected with one of the viral constructs either lacking or expressing the various HIV-1 genes. We found that HIV-1 nef was necessary and sufficient for proliferation of podocytes and down-regulation of synaptopodin and CALLA. These data suggest that Nef induces many of the changes we observe in HIV transgenic model and, as a result, this now defines the pathway for exploration of host responses to HIV-1 infection.
Asbestos fiber concentrations resulting from the installation, maintenance and removal of vinyl-asbestos floor tile

This paper presents the results of a systematic study to measure the exposure to asbestos fiber concentrations associated with occupational use of asbestos-containing floor tile. Specifically, air measurements were made during floor tile installation, maintenance and removal. The procedures for these tests are outlined and the results of the air sampling and analysis are discussed.
Misleading textbook illustrations of simple harmonic motion.

A sinusoidal wave is generated by the projection of simple harmonic motion onto a Cartesian plane (typically, the x axis is denoted as ‘time’). Five leading textbooks on sensation mislead their rea...
Sensitivity to platelet aggregation appears related to the lipoprotein profile and atherosclerosis risk in humans and across species

Platelet aggregation sensitivity was assessed in nine species of animals, including humans, with disparate susceptibility to atherosclerosis and a wide range in their LDL/HDL profiles. Platelet aggregation sensitivity between species varied almost 20-fold. The most sensitive platelets were found in humans and rabbits, followed by squirrel and rhesus monkeys with the most resistant platelets in cats, hamsters, rats, cebus monkeys, and gerbils. Species platelet aggregation sensitivity correlated well with relative susceptibility to atherosclerosis. The relationship between LDL/HDL ratio and platelet aggregation was significant, both across species (r = 0.76, without cebus) and within species (r = 0.50 for humans).
Assessment of usual dietary intake in population studies of gene-diet interaction.

Abstract Aims Dietary intake is a critical environmental exposure when considering the effect of many genetic factors on disease risk. However, dietary intake is a complex and changing measure that requires particular care in assessment. Data synthesis Although weighed diet records can theoretically provide the most accurate assessment of intake, they are usually not realistic in large population studies due to heavy respondent burden, likelihood of poor compliance, and the cost of data entry. Multiple 24-h dietary recalls can provide excellent detail, allowing for diverse dietary practices, but they are costly and require multiple contacts with participants. Food frequency questionnaires are the most cost-effective tool for assessing usual intake, particularly for micronutrients with high day-to-day variability. However, they have limitations for diverse populations and recent studies have questioned their ability to measure macronutrient intakes for assessing diet and disease relationships. Conclusion At the present time, food frequencies remain the most cost-effective tool for large population studies. However, their limitations must be fully appreciated and demonstration of validity for nutrients of concern in the populations under study is essential. When macronutrients are of key interest, consideration should be given to the use of multiple recalls. Records may be used only in educated and compliant populations. Continued efforts to improve dietary assessment methodology must be investigated.
Effect of α-actinin on actin structure viscosity studies

The effect of ATP on ability of alpha-actinin to increase viscosity of F-actin was measured in three different solutions: 100 mM KCl; 100 mM KCl/l mM Mg2+; and Mg2+ alone at concentrations of 1-6 mM. When ATP and Mg2+ are added at equimolar ratios or at added [ATP] to added [Mg2+] greater than equimolar, alpha-actinin has no effect on F-actin viscosity in the absence of KCl. ATP decreases viscosity of alpha-actinin/F-actin mixtures by 20% even in the presence of KCl, evidently because ATP affects the alpha-actinin-F-actin interaction. Molar ratios of 1 alpha-actinin to 49 actins increase specific viscosity of F-actin approx. 2-fold at 37 degrees C in the presence of 1 mM ATP, so ATP does not prevent the alpha-actinin-F-actin interaction.
Transcriptional Regulation of β-Secretase by p25/cdk5 Leads to Enhanced Amyloidogenic Processing

Cyclin-dependent kinase 5 (cdk5) has been implicated in Alzheimer's disease (AD) pathogenesis. Here, we demonstrate that overexpression of p25, an activator of cdk5, led to increased levels of BACE1 mRNA and protein in vitro and in vivo. A p25/cdk5 responsive region containing multiple sites for signal transducer and activator of transcription (STAT1/3) was identified in the BACE1 promoter. STAT3 interacts with the BACE1 promoter, and p25-overexpressing mice had elevated levels of pSTAT3 and BACE1, whereas cdk5-deficient mice had reduced levels. Furthermore, mice with a targeted mutation in the STAT3 cdk5 responsive site had lower levels of BACE1. Increased BACE levels in p25 overexpressing mice correlated with enhanced amyloidogenic processing that could be reversed by a cdk5 inhibitor. These data demonstrate a pathway by which p25/cdk5 increases the amyloidogenic processing of APP through STAT3-mediated transcriptional control of BACE1 that could have implications for AD pathogenesis.
"The sound of one paw clapping" isn't sound.

The data and analyses presented by Collins in his recent paper, “The Sound of One Paw Clapping”, are shown to provide no information regarding the relative roles of genes and environment in determining human hand preference. Arguments are given which establish that Collins misinterprets the sibling-sibling correlation and fails to test its significance. The genetic component of laterality is demonstrated to be very much underestimated by an analysis based on twin data. It is proved that a single environmental factor which produces parentoffspring resemblance necessarily yields a positive correlation between siblings and that Collins' “nongenetic model for the inheritance of handedness” is a tautology.
On the symmetric treatment of an asymmetric approach to factor analysis

On the assumption that a partitioning can be found such that three mutually exclusive test vector configurations span the same factor space, a procedure is derived whereby symmetric parts of the correlation matrix are estimated from functions of asymmetric parts treated symmetrically. This yields an explicit matrix formula for communality estimation which generalizes earlier work by Albert. Conventional factoring methods, with all their computational and fitting advantages, can be applied once the symmetric portions of the correlation matrix have been estimated. Extension to four subgroups of test vectors allows for a matrix generalization of the old tetrad difference criterion to the multiple-factor case.
MANDATED CUSTODY EVALUATIONS AND THE LIMITS OF JUDICIAL POWER

Kelly and Ramsey are clearly correct that a shift from a “how to” approach to custody evaluations to one that asks the more fundamental question “why” is long overdue. However, in addition to assessing the efficacy of custody evaluations (which Kelly and Ramsey propose), the legal system must also clarify the justification for imposing this extensive—and often expensive—intrusion into the privacy of parents. Three possible justifications for these intrusions are examined in this article: privilege, harm, and voluntariness. Is divorce a privilege, rather than a right, and can qualifications (including intrusive and expensive ones) be attached to requesting that privilege? Are custody evaluations instead justified as a means of avoiding harm to children? If a harm justification is asserted, exactly what harm do evaluations prevent, and how do they accomplish this harm avoidance? Finally, given the high value placed on parental cooperation by the family courts, is it simply too perilous for a parent to oppose a custody evaluation if one is suggested, either by the other parent or by the court? If so, are consents to custody evaluations truly voluntary?
Construction of an internal standard for semi-quantitative polymerase chain reaction analysis of heat shock proteins

We describe a simple and effective method for generating competitive cDNA fragments for use as an internal standard in semi-quantitative polymerase chain reaction (PCR). The use of a nested composite primer to a region slightly within the expected amplicon but with heat shock protein 60 kDa (hsp60) primer sequence appended to the 5' terminus of the primer produces a "mimic" DNA that will model the PCR kinetics of the target template in sequence context, and PCR primer site, and that will be similar in size. This ensures that both competitor and target template are subjected to similar PCR kinetics and so allows more meaningful quantitation.
Extraction of biofuels and biofeedstocks from aqueous solutions using ionic liquids

Abstract The production from biomass of chemicals and fuels by fermentation, biocatalysis, and related techniques implies energy-intensive separations of organics from relatively dilute aqueous solutions, and may require use of hazardous materials as entrainers to break azeotropes. We consider the design feasibility of using ionic liquids as solvents in liquid–liquid extractions for separating organic compounds from dilute aqueous solutions. As an example, we focus on the extraction of 1-butanol from a dilute aqueous solution. We have recently shown ( Chapeaux et al., 2008 ) that 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide shows significant promise as a solvent for extracting 1-butanol from water. We will consider here two additional ionic liquids, 1-(6-hydroxyhexyl)-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide and 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, as extraction solvents for 1-butanol. Preliminary design feasibility calculations will be used to compare the three ionic liquid extraction solvents considered. The ability to predict the observed ternary liquid–liquid equilibrium behavior using selected excess Gibbs energy models, with parameters estimated solely using binary data and pure component properties, will also be explored.
FRICTION AND MOLECULAR DEFORMATION IN THE TENSILE REGIME

Recent molecular level studies of energy dissipation in sliding friction have suggested a contribution from adhesive forces. In order to observe this directly, we have constructed a scanning force microscope with decoupled lateral and normal force sensors to simultaneously observe the onset of both friction and attractive forces. Measurements made on self-assembling alkanethiol films with chemically different tail groups show that friction can increase with stronger adhesive intermolecular forces and from the associated tensile deformation and collective motion of the thiol chains. {copyright} {ital 1999} {ital The American Physical Society}
THE CRISIS OF HERMENEUTICAL CONSCIOUSNESS IN MODERN CHINA

L'A. montre la necessite de redefinir une nouvelle conscience hermeneutique parmi les intellectuels chinois, afin de decouvrir la signification de la tradition chinoise face a un monde moderne desenchante qui s'impose la tâche de sa propre reconstruction philosophique
Design of long period pseudo-random sequences from the addition of m -sequences over F p

Pseudo-random sequence with good correlation property and large linear span is widely used in code division multiple access (CDMA) communication systems and cryptology for reliable and secure information transmission. In this paper, sequences with long period, large complexity, balance statistics, and low cross-correlation property are constructed from the addition of m- sequences with pairwise-prime linear spans (AMPLS). Using m-sequences as building blocks, the proposed method proved to be an efficient and flexible approach to construct long period pseudo-random sequences with desirable properties from short period sequences. Applying the proposed method to F2, a signal set ((2n - 1)(2m - 1),(2n + 1)(2m + 1), (2(n+1)/2 + 1)(2(m + 1)/2 + 1)) is constructed.
Rendering expressions to improve accuracy of relevance assessment for math search

Finding ways to help users assess relevance when they search using math expressions is critical for making Mathematical Information Retrieval (MIR) systems easier to use. We designed a study where participants completed search tasks involving mathematical expressions using two different summary styles, and measured response time and relevance assessment accuracy. The control summary style used Google's regular hit formatting where expressions are presented as text (e.g. in LaTeX), while the second summary style renders the math expressions. Participants were undergraduate and graduate students. Participants in the rendered summary style (n=19) had on average a 17.18% higher assessment accuracy than those in the non-rendered summary style (n=19), with no significant difference in response times. Participants in the rendered condition reported having fewer problems reading hits than participants in the control condition. This suggests that users will benefit from search engines that properly render math expressions in their hit summaries.
Comparison of the Adjoint and Influence Coefficient Methods for Solving the Inverse Hyperthermia Problem

An adjoint formulation is derived and used to determine the elements in the Jacobian matrix associated with the inverse problem of estimating the blood perfusion and temperature fields during hyperthermia cancer treatments. This method and a previously developed influence coefficient method for obtaining that matrix are comparatively evaluated by solving a set of numerically simulated inverse hyperthermia problems. The adjoint method has the advantage of requiring fewer solutions of the bioheat transfer equation to estimate the Jacobian than does the influence coefficient method when the number of measurement sensors is significantly smaller than the number of unknown parameters. Thus, it could be a preferable method to use in hyperthermia applications where the number of sensors is strictly limited by patient considerations. However, the adjoint method requires that CPU time intensive convolutions be numerically evaluated. Comparisons of the performance of the adjoint formulation and the influence coefficient method show that, first, there is a critical ratio of the number of measurement sensors to the number of unknown parameters at which the CPU time per iteration required to calculate the Jacobian matrix is the same for both methods. The adjoint method is faster than the influence coefficient method only when the value of the ratio is less than that critical value. For the hyperthermia problems investigated in the present study, this only occurs for cases with a very small number of measurement sensors. This presents a potential problem for clinical applications because the fewer measurement sensors used, the less information that can be gathered to correctly solve the inverse problem.(ABSTRACT TRUNCATED AT 250 WORDS)
High Performance Materials by Laser Deposition

Additive Manufacturing using laser deposition has a great deal of attractiveness as a fabrication technique for metals and alloys. The combination of a high heat input, small molten volume, and incremental addition also is well suited for the production of high performance alloys and composites. The high cooling rates inherent in the process produces refined microstructures, leading to excellent as-deposited mechanical properties in conventional alloys. The high heating rates and cooling rates potentially lends itself to structurally amorphous alloys, functionally gradient materials, and nanostructured materials, among other more exotic metallic materials. By monitoring the process a map of the quality of the build can be recorded for quality assurance and validation. Flaws detected during fabrication can then be repaired in-situ. Realizing this potential will require a combination of modeling, experimental validation, and new design paradigms. Together this will lead to the greatest properties and functionalities in future products.
COMPETITION AND COOPERATION: LOCAL GOVERNMENT JOINT VENTURES FOR ECONOMIC DEVELOPMENT

ABSTRACT:Voluntary cooperative arrangements are increasingly being established among local governments for economic development purposes. This article extends the institutional collective action fr...
LRE Policy The Leadership Challenge

This article describes colorado's approach to implementation of least restrictive environment (lre) policy, specifically focused on the recent reform initiative of inclusive education. progress toward full implementation of lre is discussed and barriers presented. the authors describe how leadership from the state department of education, in partnership with other key constituents, has resulted in major change with regard to integrated placements through the special education process. because state leaders believed that the traditional identification—placement process for accessing special education services did not provide for appropriate services, they began to plan strategically for movement toward more integrated environments in the general education setting. this effort is discussed, and the partnerships that facilitated this change are highlighted. finally, emerging policy initiatives and questions about the merger of school reform with inclusive practices are explored, as well as the impact of stan...
FORCE: a fast and easy-to-implement variable-ordering heuristic

The MINCE heuristic for variable-ordering [1] can successfully reduce the size of BDDs and accelerate SAT-solving. Applications to reachability analysis have also been successful [12]. The main drawback of MINCE is its implementation complexity - the authors used a pre-existing min-cut placer [6] that is several times larger than any existing SAT solver. Tweaking MINCE is difficult.In this work we propose a replacement heuristic, FORCE which is easy to implement from scratch and tweak. It is dramatically faster than MINCE in practice. While FORCE may produce seemingly inferior variable orderings, the difference with MINCE orderings does not affect subsequent SAT-solving.
Crystal Structure of Thermus aquaticus Gfh1, a Gre-factor Paralog that Inhibits rather than Stimulates Transcript Cleavage

Transcription elongation in bacteria is promoted by Gre-factors, which stimulate an endogenous, endonucleolytic transcript cleavage activity of the RNA polymerase. A GreA paralog, Gfh1, present in Thermus aquaticus and Thermus thermophilus, has the opposite effect on elongation complexes, inhibiting rather than stimulating transcript cleavage. We have determined the 3.3 A-resolution X-ray crystal structure of T. aquaticus Gfh1. The structure reveals an N-terminal and a C-terminal domain with close structural similarity to the domains of GreA, but with an unexpected conformational change in terms of the orientation of the domains with respect to each other. However, structural and functional analysis suggests that when complexed with RNA polymerase, Gfh1 adopts a conformation similar to that of GreA. These results reveal considerable structural flexibility for Gfh1, and for Gre-factors in general, as suggested by structural modeling, and point to a possible role for the conformational switch in Gre-factor and Gfh1 regulation. The opposite functional effect of Gfh1 compared with GreA may be determined by three structural characteristics. First, Gfh1 lacks the basic patch present in Gre-factors that likely plays a role in anchoring the 3′-fragment of the backtracked RNA. Second, the loop at the tip of the N-terminal coiled-coil is highly flexible and contains extra acidic residues compared with GreA. Third, the N-terminal coiled-coil finger lacks a kink in the first α-helix, resulting in a straight coiled-coil compared with GreA. The latter two characteristics suggest that Gfh1 chelates a magnesium ion in the RNA polymerase active site (like GreA) but in a catalytically inactive configuration.
The ORPHAN Copyright Act: Open Door or a Deluge?

Despite the legislative rush to address the financial crisis of 2008, Congress nearly passed the most substantial rewrite of the copyright system in 30 years. However, organized protests by photography groups, artists, and other image-makers convinced members of the House of Representatives to take a second look at the legislation. While Congress did not pass the Shawn Bentley Orphan Copyright Act, its proponents expect to bring it up again. If enacted, the Orphan Works Act would place original, creative, and professional works in the public domain if potential users cannot find the copyright owner as long as they conduct a “reasonably diligent search” and that search fails. Researchers, archivists, and historians see the Orphan Copyright Act as a way to gain access to inaccessible archives, material, and information that have little commercial use. Artists, musicians, photographers, and other copyright holders see the act as a threat to their ability to protect their intellectual property, and therefore ...
Transient Analysis of an Overlay Multicast Protocol

This paper presents the transient performancestudy on the adaptability of an application layer multicastprotocol, namely Adaptive Overlay Multicast (AOM). The studyfocuses on how the application layer multicast tree structure adapts to network dynamics and faults by using efficient tree management and adaptation algorithms, thus reducing the adverse effects of network faults on the application performance. We present extensive simulation studies as well as studies using real Internet data The results show that AOM is highly adaptive to network dynamics while incurring low overhead.
State-of-the-art timber harvest in an Arizona mixed conifer forest has minimal effect on overland flow and erosion

Abstract When the Thomas Creek, Arizona, USA, watershed was logged for the first time, the latest state-of-the-art harvesting was applied. Trees were cut in patches and by group selection, and logs skidded by crawler tractor. Although overland flow and sediment delivery, measured on small sub-drainages of the watershed, were inconsequential, sediment deliveries from severely disturbed areas and undisturbed forest floor were significantly different (41 and 6 kg ha−1 year−1, respectively). The highest erosion rates (128 kg ha−1 year−1) were created by monitoring activities which entailed the use of over-snow vehicles and trail bikes. Nearly instantaneous rises in the hydrograph at the start of storms were caused by pipe flows. Significant increases of flow volumes and peak flows after timber harvest increased magnitudes of channel adjustment processes (erosion) that had existed already before logging. This development was judged positively, because it suggests more rapid attainment of a new dynamic equilibr...
Conserving Latin American and Caribbean mangroves: issues and challenges

This is a literature review of the distribution, salient features, uses, and conservation of mangroves in the Caribbean and Latin America. These ecosystems have played a vital role in the development of the region and their value increases as tropical countries develop and commercialize their coastal zones. Unfortunately, markets ignore or underestimate the value of products and non-market services from mangroves. Science informs and improves the effectiveness of the conservation of mangroves. Professional management with participation of all sectors of society also benefits the conservation of mangroves. Understanding mangrove ecosystems requires consideration of multiple spatial and temporal scales and attention to paradoxes that can lead to ineffective conservation measures. The review includes guidelines for mangrove restoration and conservation.
Identification of water-soluble organic carbon in non-urban aerosols using ultrahigh-resolution FT-ICR mass spectrometry: organic anions

Water-soluble organic carbon (WSOC) is a complex mixture of thousands of organic compounds which may have significant influence on the climate-relevant properties of atmospheric aerosols. An improved understanding of the molecularcompositionofWSOCisneededtoevaluatetheeffectofaerosol compositionuponaerosolphysicalproperties. Inthiswork,ultrahigh-resolutionFouriertransform-ioncyclotronresonancemassspectrometry(FT-ICRMS)wasusedto characterise aerosol WSOC collected during the summer of 2010 at the Storm Peak Laboratory (3210m ASL) near Steamboat Springs, CO. Approximately 4000 molecular formulas were assigned in the mass range of 100-800Da after negative-ion electrospray ionisation and more than 50% of them contained nitrogen or sulfur. The double bond equivalents (DBEs) of the molecular formulas were inversely proportional to the O:C ratio, despite a relatively constant H:C ratio of ,1.5. Despite the range of DBE values, the elemental ratios and the high number of oxygen atoms per formula indicate that a majority of the compounds are aliphatic to olefinic in nature. These trends indicate significant non-oxidative accretion reaction pathways for the formation of high molecular weight WSOC components. In addition, a significant number of molecular formulas assigned in this work matched those previously identified as secondary organic aerosol components of monoterpene and sesquiterpene ozonolysis. Additional keywords: atmospheric organic matter, electrospray ionisation, FT-ICR MS, high-resolution MS, humic- like substances, nitrooxy organosulfates, organonitrates, organosulfates, secondary organic aerosol.
Detection of intrauterine illicit drug exposure by newborn drug testing

Identification of intrauterine drug-exposed newborns with toxicological screening may have benefits including close follow-up of the infant by both medical and social services. Applying specific written guidelines to select newborns for drug testing decreases bias and protects the physicians and hospitals involved. All drugs reported as positive should be confirmed by an appropriate second test. Urine and meconium testing are the best current options for identifying drug-exposed neonates. Urine testing sensitivity is low because of problems encountered in urine collections and the high thresholds used in current urine assays. The disadvantage to meconium testing is the increased labor and time required to work with this material. Testing of newborn hair is unlikely to be widely used until technically less demanding assays become available. Testing of amniotic fluid or gastric lavage is still in the developmental stages. Adopting lower urine assay thresholds for newborn samples would increase sensitivity and would be an appropriate modification of current methodologies.
Implementation of vascular‐space‐occupancy MRI at 7T

Vascular-space-occupancy (VASO) MRI exploits the difference between blood and tissue T1 to null blood signal and measure cerebral blood volume changes using the residual tissue signal. VASO imaging is more difficult at higher field because of sensitivity loss due to the convergence of tissue and blood T1 values and increased contamination from blood-oxygenation-level-dependent (BOLD) effects. In addition, compared to 3T, 7T MRI suffers from increased geometrical distortions, e.g., when using echo-planar-imaging, and from increased power deposition, the latter especially problematic for the spin-echo-train sequences commonly used for VASO MRI. Third, non-steady-state blood spin effects become substantial at 7T when only a head coil is available for radiofrequency transmit. In this study, the magnetization-transfer-enhanced-VASO approach was applied to maximize tissue-blood signal difference, which boosted signal-to-noise ratio by 149% ± 13% (n = 7) compared to VASO. Second, a 3D fast gradient-echo sequence with low flip-angle (7°) and short echo-time (1.8 ms) was used to minimize the BOLD effect and to reduce image distortion and power deposition. Finally, a magnetization-reset technique was combined with a motion-sensitized-driven-equilibrium approach to suppress three types of non-steady-state spins. Our initial functional MRI results in normal human brains at 7T with this optimized VASO sequence showed better signal-to-noise ratio than at 3T.
The influence of head tracking and stereo on user performance with non-isomorphic 3D rotation

We present an experimental study that explores how head tracking and stereo viewing affect user performance when rotating 3D virtual objects using isomorphic and non-isomorphic rotation techniques. Our experiment com- pares isomorphic with non-isomorphic rotation utilizing four different display modes (no head tracking/no stereo, head tracking/no stereo, no head tracking/stereo, and head tracking/stereo) and two different angular error thresh- olds for task completion. Our results indicate that rotation error is significantly reduced when subjects perform the task using non-isomorphic 3D rotation with head tracking/stereo than with no head tracking/no stereo. In addition, subjects performed the rotation task with significantly less error with head tracking/stereo and no head tracking/stereo than with no head tracking/no stereo, regardless of rotation technique. The majority of the subjects tested also felt stereo and non-isomorphic amplification was important in the 3D rotation task.
Meta-analysis: increased mortality associated with hepatitis C in HIV-infected persons is unrelated to HIV disease progression.

the risk ratio was 1.12 (95% CI, 0.82‐1.51) for AIDS-defining events and 1.35 (95% CI, 1.11‐1.63) for overall mortality among coinfected patients, compared with that among patients with HIV monoinfection. Conclusions. HCV coinfection did not increase mortality among patients with HIV infection before the introduction of HAART. In contrast, in the HAART era, HCV coinfection, compared with HIV infection alone, increases the risk of mortality, but not the risk of AIDS-defining events. Future studies should determine whether successful treatment of HCV infection could reduce this excess risk of mortality in coinfected patients.
The cost of reproduction: the devil in the details

The cost of reproduction is of fundamental importance in life-history evolution. However, our understanding of its mechanistic basis has been limited by a lack of detailed functional information at all biological levels. Here, we identify, evaluate and integrate recent studies in five areas examining the proximate mechanisms underlying the cost of reproduction. Rather than being alternate explanations, hormonal regulation and intermediary metabolism act in concert and have an overarching influence in shaping the cost of reproduction. Immune function is compromised by reproduction, as is resistance to environmental stress. These studies not only provide new information about mechanisms that comprise 'the cost', but also hint at an underlying evolutionarily conserved causal mechanism.
Simulation of pavement roughness and IRI based on power spectral density

The international roughness index (IRI) for evaluating pavement surface roughness is simulated using the power spectral density (PSD) of pavement surface fluctuation. Quarter-car models recommended by the World Bank for measuring pavement roughness are adopted to simulate vehicle response. Surface roughness in time domain is generated based on 36 known PSDs of roughness. Newmark sequential integration method is employed to conduct the simulation of quarter-car motion. Statistical analysis of system output shows that the IRI is linearly correlated with the standard deviation of relative vertical velocity between the axle and sprung mass. A linear regression equation is obtained, based on which further analysis is conducted to represent the IRI in terms of PSD roughness. It is found that if PSD roughness is expressed as a polynomial function, the IRI can be simply calculated by means of the square root of the sum of the weighted regression coefficients of PSD roughness. The weighting coefficients are provided and can be conveniently used in practice.
Effects of vitamins C and E on carcinogen formation and action, and relationship to human cancer.

To introduce this subject, I will briefly review the inhibition by vitamins C and E of the formation of carcinogenic nitrosamines and nitrosamides (N-nitroso compounds), as well as effects of these vitamins on carcinogenesis and human cancer. I have previously reviewed the inhibition by vitamins C and E of N-nitroso compound formation (4, 5) and hope shortly to publish a more complete review on the subject (7).
Neutrality regulation mechanisms in rats receiving sulfonic ion exchange resin.

SummaryRats receiving sulfonic acid resin respond by increasing their urinary output of acid phosphate and ammonia, but not in amounts sufficient to compensate for their fecal alkali loss. Those receiving moderate amounts of potassium resin show little change in acid-base balance, while those on high potassium resin intakes show a partially compensated alkali retention. The net fecal alkali loss amounts to 2.4 meq per g resin fed, but a large part of this represents increased phosphate absorption, presumably due to the binding of calcium and/or magnesium by the resin. There is suggestive evidence that some of the extra alkali appearing in the feces as a result of resin ingestion is not in direct combination with the resin, and this may have some bearing on the problem of neutrality regulation.
A New Bioinspired Perchlorate Reduction Catalyst with Significantly Enhanced Stability via Rational Tuning of Rhenium Coordination Chemistry and Heterogeneous Reaction Pathway.

Rapid reduction of aqueous ClO4– to Cl– by H2 has been realized by a heterogeneous Re(hoz)2–Pd/C catalyst integrating Re(O)(hoz)2Cl complex (hoz = oxazolinyl-phenolato bidentate ligand) and Pd nanoparticles on carbon support, but ClOx– intermediates formed during reactions with concentrated ClO4– promote irreversible Re complex decomposition and catalyst deactivation. The original catalyst design mimics the microbial ClO4– reductase, which integrates Mo(MGD)2 complex (MGD = molybdopterin guanine dinucleotide) for oxygen atom transfer (OAT). Perchlorate-reducing microorganisms employ a separate enzyme, chlorite dismutase, to prevent accumulation of the destructive ClO2– intermediate. The structural intricacy of MGD ligand and the two-enzyme mechanism for microbial ClO4– reduction inspired us to improve catalyst stability by rationally tuning Re ligand structure and adding a ClOx– scavenger. Two new Re complexes, Re(O)(htz)2Cl and Re(O)(hoz)(htz)Cl (htz = thiazolinyl-phenolato bidentate ligand), significant...
The ‘Popular Economy’: Laboring Peasants and Markets Without Capitalists, 1895–1904

In the 1880s and early 1890s government policy reinforced communal institutions and estate segregation in an effort to protect peasants from new economic forces and the purportedly dangerous influence of other estates. The ultimate aim of these policies was social stability, and from the early 1890s confidence in this approach waned in the wake of a highly publicized famine, the perception of steady peasant impoverishment, and, at the turn of the century, fears of imminent peasant rebellion.1 In this context, a new group of officials concentrated in the Ministry of Finance argued that economic change was natural and inevitable, and that peasants should be drawn into an integrated economy through state-supervised credit and rational trading mechanisms. Such conceptions presumed increased contact among the estates, and officials revived discussion of cooperatives as institutions that were formally all-estate in composition. Their deliberations culminated in the Statute of Small Credit of 1904 and new state sponsorship of agricultural arteli.
Risk Factors for Refractory Epilepsy

The factors associated with a poor seizure response to therapy were evaluated in 525 patients, children and adults, followed at The Epilepsy Unit, Western Infirmary, Glasgow, Scotland.
The Special Sensor Ultraviolet Limb Imager instruments

The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors flying on the United States Air Force Defense Meteorological Satellite Program (DMSP) Block 5D-3 satellites. The SSULIs cover the 800-1700 A wavelength range at 18 A spectral resolution. This wavelength range contains spectral signatures of all the dominant neutral and ionized species in the thermosphere and F-region ionosphere. The instruments view ahead of the spacecraft and operate as limb imagers covering the 100-750 km altitude range at 10-15 km resolution with a 90-second scan cadence. We describe these instruments and summarize their calibration and on-orbit performance. Day-to-day variability of the nighttime ionosphere at low-latitudes and longer-term variability of the global mean exospheric temperature are highlighted.