cssi/SciSciGPT-SciSciNet huggingface dataset:
Steric and electronic effects on arylthiolate coordination in the pseudotetrahedral complexes [(TpPh,Me)Ni–SAr] (TpPh,Me = hydrotris{3-phenyl-5-methyl-1-pyrazolyl}borate)

Synthesis and characterization of several new pseudotetrahedral arylthiolate complexes [(TpPh,Me)Ni–SAr] (TpPh,Me = hydrotris{3-phenyl-5-methyl-1-pyrazolyl}borate; Ar = Ph, 2,4,6-iPr3C6H2, C6H4-4-Cl, C6H4-4-Me, C6H4-4-OMe) are reported, including X-ray crystal structures of the first two complexes. With prior results, two series of complexes are spanned, [(TpPh,Me)Ni–S–2,4,6-R′′3C6H2] (R′′ = H, Me, iPr) plus the xylyl analogue [(TpPh,Me)Ni–S–2,6-Me2C6H3], as well as [(TpPh,Me)Ni–S–C6H4–4-Y] (Y = Cl, H, Me, OMe), intended to elucidate steric and/or electronic effects on arylthiolate coordination. In contrast to [(TpMe,Me)Ni–SAr] analogues that adopt a sawhorse conformation, the ortho-disubstituted complexes show enhanced trigonal and Ni–S–Ar bending, reflecting the size of the 3-pyrazole substituents. Moreover, weakened scorpionate ligation is implied by spectroscopic data. Little spectroscopic effect is observed in the series of para-substituted complexes, suggesting the observed effects are primarily steric in origin. The relatively electron-rich and encumbered complex [(TpPh,Me)Ni–S–2,4,6-iPr3C6H2] behaves uniquely when dissolved in CH3CN, forming a square planar solvent adduct with a bidentate scorpionate ligand, [(κ2-TpPh,Me)Ni(NCMe)(S–2,4,6-iPr3C6H2)]. This adduct was isolated and characterized by X-ray crystallography. Single-point DFT and TD-DFT calculations on a simplified [(κ2-Tp)Ni(NCMe)(SPh)] model were used to clarify the electronic spectrum of the adduct, and to elucidate differences between Ni–SAr bonding and spectroscopy between pseudotetrahedral and square planar geometries.
Functional proteolytic complexes of the human mitochondrial ATP-dependent protease, hClpXP.

Human mitochondrial ClpP (hClpP) and ClpX (hClpX) were separately cloned, and the expressed proteins were purified. Electron microscopy confirmed that hClpP forms heptameric rings and that hClpX forms a hexameric ring. Complexes of a double heptameric ring of hClpP with hexameric hClpX rings bound on each side are stable in the presence of ATP or adenosine 5′-(3-thiotriphosphate) (ATPγS), indicating that a symmetry mismatch is a universal feature of Clp proteases. hClpXP displays both ATP-dependent proteolytic activity and ATP- or ATPγS-dependent peptidase activity. hClpXP cannot degrade λO protein or GFP-SsrA, specific protein substrates recognized by Escherichia coli (e) ClpXP. However, eClpX interacts with hClpP, and, when examined by electron microscopy, the resulting heterologous complexes are indistinguishable from homologous eClpXP complexes. The hybrid eClpX-hClpP complexes degrade eClpX-specific protein substrates. In contrast, eClpA can neither associate with nor activate hClpP. hClpP has an extra C-terminal extension of 28 amino acids. A mutant lacking this C-terminal extension interacts more tightly with both hClpX and eClpX and shows enhanced enzymatic activities but still does not interact with eClpA. Our results establish that human ClpX and ClpP constitute a bone fide ATP-dependent protease and confirm that substrate selection, which differs between human and E. coli ClpX, is dependent solely on the Clp ATPase. Our data also indicate that human ClpP has conserved sites required for interaction with eClpX but not eClpA, implying that the modes of interaction with ClpP may not be identical for ClpA and ClpX.
Canine exposure to Borrelia burgdorferi and prevalence of Ixodes dammini (Acari: Ixodidae) on deer as a measure of Lyme disease risk in the northeastern United States.

Surveillance programs that identify areas where both the vector (Ixodes dammini) and etiologic agent (Borrelia burgdorferi) are present may identify the risk of Lyme disease and its spread earlier and more accurately than do programs relying on any single method, particularly human case reports. Hunter-killed deer ( n = 1,204) from 22 counties in Maryland, Massachusetts, New Hampshire, New York, and Pennsylvania were examined in fall 1989 and all ectoparasites were identified. The following spring, canine sera ( n = 884) were obtained from these sites, which included known endemic areas and those where Lyme disease is uncommon, and tested by enzyme-linked immunosorbent assay. Regression analysis of canine seroprevalence versus tick prevalence on deer from the same counties demonstrate a significant positive linear relationship. Sites were designated as low-, moderate-, or high-risk counties based upon their position on the regression curve. The geographic distribution of the sites correlated well with the distribution of known Lyme disease endemic and nonendemic areas. Locations were also identified where Lyme disease may be emerging. The positive relationship between measures of vector and pathogen abundance determined in this study permits public health workers to identify endemic and potentially endemic areas independently of human case reports.
Transferring learning from external to internal weights in echo-state networks with sparse connectivity.

Modifying weights within a recurrent network to improve performance on a task has proven to be difficult. Echo-state networks in which modification is restricted to the weights of connections onto network outputs provide an easier alternative, but at the expense of modifying the typically sparse architecture of the network by including feedback from the output back into the network. We derive methods for using the values of the output weights from a trained echo-state network to set recurrent weights within the network. The result of this “transfer of learning” is a recurrent network that performs the task without requiring the output feedback present in the original network. We also discuss a hybrid version in which online learning is applied to both output and recurrent weights. Both approaches provide efficient ways of training recurrent networks to perform complex tasks. Through an analysis of the conditions required to make transfer of learning work, we define the concept of a “self-sensing” network state, and we compare and contrast this with compressed sensing.
Door-to-balloon time: performance improvement in the multidisciplinary treatment of myocardial infarction.

: The treatment of ST-elevation myocardial infarction with primary percutaneous coronary intervention is a time-sensitive process, with outcomes correlated with the speed with which the healthcare team can make the diagnosis, start preliminary treatment, and successfully perform the intervention. This requires multidisciplinary teamwork involving Emergency Medical Services, Emergency Medicine and Nursing, the cardiac catheterization laboratory team, and interventional cardiology. The success of effectively delivering treatment is enhanced through focused analysis of key steps within the care process to identify systems problems and implement quality improvement initiatives. This article reviews the process whereby our institution achieved top decile performance in this multidisciplinary treatment.
SU‐GG‐T‐276: Comparison of the Epson Perfection V700 Photo Flatbed and the Vidar VXR‐16 Dosimetry PRO AdvantageTM Film Scanners for Use with Radiochromic Film

Purpose: The purpose of this study was to compare the performance and utility of a commercially available flatbed scanner with that of a widely‐used medical film scanner for use with radiochromic film. Method and Materials: This project compares the Vidar VXR Dosimetry Pro and the Epson Perfection V700 Photo flatbed scanner. Using radiochromic EBT film irradiated to a known range of doses 0–512 cGy using eight 3×3 cm fields on a single film, both scanners were characterized for scan repeatability, orientation effects, uniformity, and scanner noise. RIT V5.0 was used to determine pixel value (PV) of Vidar scans, while ImageJ software was used for the Epson scans. Results: For the range of doses measured, average pixel values of a central 1.5×1.5 cm region of interest (ROI) were reproducible within 0.1% standard deviation with Vidar and approximately 0.2% with Epson. Epson mean PV differed by up to 18% for all dosed regions from landscape to portrait orientation, while only up to 5% for Vidar. From 0 to 512 cGy, identical films showed a 10% wider PV range for Vidar than Epson. Scanner noise was minimal; Epson showed a maximum SD of 1.00% from the mean of the central ROI, Vidar showed 1.14%. In both systems, cross profiles for an unirradiated film showed deviations in PV no more than 2% of the mean. Conclusion: No clear significant accuracy advantage was noted in either system, provided the leading and trailing 1 cm film edges were neglected with the Vidar system. Although the Epson scanner is a relatively inexpensive method for analyzing radiochromic film, the lack of commercially available software for it could be a major disadvantage. Hence, an institution already having a Vidar system may find its use with radiochromic film attractive.
A Novel Form of the G Protein β Subunit Gβ5 Is Specifically Expressed in the Vertebrate Retina

The G protein β subunit, Gβ_5, is predominantly expressed in the central nervous system. In rodent brain, Gβ_5 is expressed as a protein with an apparent molecular mass of 39,000 daltons (39 kDa). We have identified an additional Gβ_5 immunoreactive protein of apparent size 44 kDa in the vertebrate retina. Molecular cloning and sequencing of polymerase chain reaction products revealed that the cDNA encoding the larger species of Gβ_5 (Gβ_(5L)) was identical to the shorter form with the addition of 126 base pairs of 5′ DNA sequence potentially encoding an in-frame 42-amino acid extension. Sequencing of mouse Gβ_5 genomic clones demonstrated that the 126-base pair of retinal-specific coding material is derived from a hitherto undetected 5′ exon. During sucrose density gradient fractionation of bovine retinas, the 44-kDa Gβ_(5L) protein co-purified with rod outer segment membranes. Incubation of rod outer segment membranes with the nonhydrolyzable guanine nucleotide, GTPγS (guanosine 5′-3-O-(thio)triphosphate), which released the Gβ subunit of transducin (Gβ_1), failed to remove Gβ_(5L). The 39-kDa Gβ_5 protein displayed differential association with retinal and brain membranes. In the retina, Gβ_5 was present as a soluble protein and was undetectable in the membrane fraction, whereas in the brain approximately 70% of Gβ_5 was associated with cellular membranes. In transient COS-7 cell expression experiments, Gβ_(5L) formed functional Gβγ dimers and Gαβγ heterotrimers, and activated phosphoinositide-specific phospholipase Cβ_2 in a manner indistinguishable from the 39-kDa Gβ_5 protein. The cloning of the retinal-specific Gβ_(5L) cDNA suggests the existence of potentially novel G protein-mediated signaling cascades in photoreception.
Charting the Landscape of Children's Rights

This issue of the Journal of Social Issues presents current theory, research, and methodological considerations pertaining to “Young People's Perspectives on the Rights of the Child.” The following brief introduction charts the landscape of children's rights by outlining the purpose and goals of the issue, provides a short historical overview on the topic, sets the context for the individual articles, and highlights the recurring themes making up this issue of JSI. The authors of the articles in this issue extend current knowledge and thinking on the topic of children rights and also set the foundation for future empirical work, practice, and policy pertaining to children's rights and rights-focused research.
Properties and origin of the transducing particles in low frequency transduction by bacteriophage λ

Abstract From a culture of the lysogenic gal+ strain C600 (λ) substrains can be isolated which liberate more gal+-transducing particles per cell than the parent culture. During growth these substrains revert rapidly to the original condition. The transducing phage particles derived from a single substrain are not homogeneous in density. This indicates that each substrain does not carry a defective phage of predetermined density, as is true in the case of a heterogenote strain carrying a λdg prophage. Equilibrium centrifugation analyses of the density distribution of LFT lysates reveal two classes of LFT particles: one class of homogeneous density, like that of active phage λb1+, and one of particles less dense than λ, which vary widely in density. This suggests the possibility that there are two mechanisms of determination of the final density. Differences are observed in the transducing properties of LFT particles as compared with HFT particles. The LFT particles have an absolute requirement for the presence of an active phage genome in the recipient cell in order to carry out transduction, whereas the HFT particles can transduce at a low rate without active phage. If LFT lysates of one immunity type are used to transduce gal− cells that carry active phage of another immunity type, the resulting clones segregate out transduced cells in which the immunity character of the defective prophage has been changed to that of the prophage carried by the recipient cell. They also segregate out gal+ cells which no longer carry any defective phage. Both of these types are exceptional among segregants of gal− cells transduced by HFT lysates. Because of the presence of a density marker b1 closely linked to or included in the c region of one of the two phage strains studied, it was possible to test for the presence or absence of this density marker in the LFT transducing particles that comprise the peak of higher density. This marker appears to be missing in these LFT particles, suggesting a defect in the c region. The b1 marker reappears in the HFT particles, presumably because these are formed by recombination of an LFT particle with an active phage.
Active Control for a Distributed Mass Damper System

AbstractRecent developments of a distributed mass damper (DMD) system integrate structural and environmental control systems for buildings. This system simultaneously improves building safety and sustainability by using external shading fins as mass dampers, controlling the amount of sunlight coming into the building for energy efficiency, and reducing structural movements during strong motions. Unlike traditional mass dampers, which are usually placed at the tops of structures, the shading fin mass dampers (SFMDs) are distributed throughout structures because fins are placed along the entire heights of buildings. A recent paper by the authors shows that the passive DMD system is as effective in response mitigation as a conventional tuned mass damper (TMD). In this paper, active control strategies for mass damper control are analyzed and simulated to show further response reductions. Nonpassive controls are of interest for the SFMD system because actuators are already needed to control the positions of th...
Electron microscopic study of the rodent “Picodnavirus” X14

Abstract The fine structure of the rat virus X14 has been studied in the electron microscope by negative staining and ultra-thin sectioning techniques. The virion appears to be a member of the T = 3 icosadeltahedral series with a markedly concave image in the electron microscope. The virus develops first in the nucleus of the infected cell and cannot be detected in the electron microscope until 3 days after inoculation. This investigation was supported in part by Public Health Service research grant CA 04600 from the National Cancer Institute and grant AI 05382 from the National Institute for Allergy and Infectious Diseases, National Institutes of Health. The authors are grateful to Dr. J. L. Melnick for his continuing support and very helpful criticism of this manuscript.
Modes of Speech as a Developmental Hierarchy: A Descriptive Study.

The purpose of the present study was to (1) determine whether a developmental hierarchy exists for communicative competence in much the same way that it exists for linguistic competence and to test whether the modes of speech continuum adequately accounts for this hierarchy, (2) investigate the interaction of form and function by examining whether a relationship exists between the child's mastery of linguistic forms and his/her ability to meet complex functional demands. Two separate instruments were used to gather speech samples from 86 children from three preschools. In order to describe the linguistic competence of the children in three age groups, a picture elicitation technique was employed to collect utterances which were then linguistically analyzed and categorized as simple and generalized transformations. Results indicated that communicative competence increased with age and suggested a hierarchy from context‐centered probes through topic‐centered probes. Linguistic competence, characterized as s...
Graphical Representations of Speed: Obstacles Preservice K-8 Teachers Experience.

This study examines the difficulties college students experience when creating and interpreting graphs in which speed is one of the variables. Nineteen students, all preservice elementary or middle school teachers, completed an upper-level course exploring algebraic concepts. Although all of these preservice teachers had previously completed several mathematics courses, including calculus, they demonstrated widespread misconceptions about the variable speed. This study identifies four cognitive obstacles held by the students, provides excerpts of their graphical constructions and verbal interpretations, and discusses potential causes for the confusion. In particular, misconceptions arose when students interpreted the behavior and nature of speed within a graphical context, as well as in situations where they were required to construct a graph involving speed as a variable. The study concludes by offering implications for the teaching and learning of speed and its interpretation within a graphical setting.
Infrared Dispersion of Some Organic Liquids

The dispersion of carbon tetrachloride, carbon disulfide, chloroform, cyclohexane, tetrachloroethylene, methylene iodide, acetone, and perfluoro 1,3,5-trimethylcyclohexane has been measured in the 2–15 μ region using an interferometric method. The problem of assigning the proper orders of interference to the observed fringe system has been solved by studying the compounds of interest dissolved in carbon disulfide and carbon tetrachloride. Since the orders of interference can be reliably determined for these two solvents one can follow the shift in order as the concentration of the solute is increased in a stepwise fashion from 0 to 100%.
Spacecraft attitude dynamics and control - A personal perspective on early developments

Introduction W some trepidation I accepted the invitation to join the ranks of better authorities who have chronicled the history of key technologies in a series' published in the Journal of Guidance, Control, and Dynamics. My experience is more limited than that of the other contributors to this interesting collection of articles, arid iny narrative should be recognized as no more than the personal perspective of one observer and participant in the evolution of the field of spacecraft attitude dynamics, stabilization, and control.
Computational study of the addition of OH radical to SCS

Abstract Two addition products of OH with CS2 have been studied with modified G1 theory. The addition of OH to a sulfur atom is predicted to be exothermic by 5.9 kcal/mol while the addition to a carbon atom is exothermic by 30.3 kcal/mol. However, better agreement with experiment is obtained if it is assumed that the sulfur atom adduct is the major product formed under experimental conditions. The saddle points for OH additions were also calculated at modified Gl theory and it was found that OH added to a sulfur atom without activation and to a carbon atom with an activation barrier of 7.0 kcal/mol. Thus, the product formed by addition of OH to CS2 is the kinetic product rather than the thermodynamic product.
Assessing Public Preferences for Forest Biomass Based Energy in the Southern United States

This article investigated public preferences for forest biomass based liquid biofuels, particularly ethanol blends of 10% (E10) and 85% (E85). We conducted a choice experiment study in three southern states in the United States: Arkansas, Florida, and Virginia. Reducing atmospheric CO(2), decreasing risk of wildfires and pest outbreaks, and enhancing biodiversity were presented to respondents as attributes of using biofuels. Results indicated that individuals had a positive extra willingness to pay (WTP) for both ethanol blends. The extra WTP was greater for higher blends that offered larger environment benefits. The WTPs for E10 were $0.56 gallon(-1), $0.58 gallon(-1), and $0.48 gallon(-1), and for E85 they were $0.82 gallon(-1), $1.17 gallon(-1), and $1.06 gallon(-1) in Arkansas, Florida, and Virginia, respectively. Although differences in WTP for E10 were statistically insignificant among the three states, significant differences were found in the WTP for E85 between AR and FL and between AR and VA. Preferences for the environmental attributes appeared to be heterogeneous, as respondents' were willing to pay a premium for E10 in all three states to facilitate the reduction of CO(2) and the improvement of biodiversity but were not willing to pay more for E85 in order to enhance biodiversity.
Independent regulation of Hsp70 and Hsp90 chaperones by Hsp70/Hsp90-organizing protein Sti1 (Hop1)

Hsp70 and Hsp90 protein chaperones cooperate in a protein-folding pathway required by many "client" proteins. The co-chaperone Sti1p coordinates functions of Hsp70 and Hsp90 in this pathway. Sti1p has three tetratricopeptide repeat (TPR) domains. TPR1 binds Hsp70, TPR2a binds Hsp90, and the ligand for TPR2b is unknown. Although Sti1p is thought to be dedicated to the client folding pathway, we earlier showed that Sti1p regulated Hsp70, independently of Hsp90, in a way that impairs yeast [PSI+] prion propagation. Using this prion system to monitor Sti1p regulation of Hsp70 and an Hsp90-inhibiting compound to monitor Hsp90 regulation, we identified Sti1p mutations that separately affect Hsp70 and Hsp90. TPR1 mutations impaired Sti1p regulation of Hsp70, but deletion of TPR2a and TPR2b did not. Conversely, TPR2a and TPR2b mutations impaired Sti1p regulation of Hsp90, but deletion of TPR1 did not. All Sti1p mutations variously impaired the client folding pathway, which requires both Hsp70 and Hsp90. Thus, Sti1p regulated Hsp70 and Hsp90 separately, Hsp90 is implicated as a TPR2b ligand, and mutations separately affecting regulation of either chaperone impair a pathway that is dependent upon both. We further demonstrate that client folding depended upon bridging of Hsp70 and Hsp90 by Sti1p and find conservation of the independent regulation of Hsp70 and Hsp90 by human Hop1.
Clinical and electrophysiologic recovery in Arnold-Chiari malformation.

Abstract The case of a 16-year-old boy with occipital headache, diplopia, ataxia, and weakness in the lower extremities of 1-month duration is reported. Slowness of mentation, speech, and motor action was also present. Massive chronic hydrocephalus was indicated by an enlarged head. The prominent clinical features suggested involvement of the brainstem, and contrast studies showed compression of the brainstem and a filling defect posteriorly at C1–2. Brainstem auditory evoked potential latency suggested bilateral lesions of the brainstem. Posterior fossa decompression confirmed the presence of an Arnold-Chiari malformation, with the cerebellar tonsils as low as C-3. The fourth ventricle was microdissected and opened. Remarkable clinical and evoked potential recovery ensued over several months. Clinical-anatomic and anatomic-physiologic correlations in Arnold-Chiari malformation are discussed.
Nitric oxide mediates C5a-induced vasodilation in the small intestine.

Objective: This study was designed to investigate the microvascular responses of the small intestine to complement C5a and to define the role of nitric oxide in the C5a-induced response.Methods: Male Sprague–Dawley rats were anesthetized with pentobarbital, and a loop of small intestine was exteriorized and suffused with Krebs solution. The diameters of large and small arterioles of the small intestinal wall were measured with in vivo videomicroscopy following the application of experimental mediators. Four 1-hr C5a dose-response trials were performed (10−14 M, 10−12 M, 10−10 M, and 10−8 M). Then, we completed acetylcholine dose-response curves with and without Nω-nitro-L-arginine (N-Arg) to document the adequacy of nitric oxide synthase inhibition. The microvascular response to the topical application of C5a (10−12 M) was recorded in the presence of 2 × 10−4 M N-Arg. Additionally, experiments of C5a-induced response with N-Arg were repeated in the presence of L-arginine (L-Arg; the precursor of nitric ox...
Mid-Cenozoic high-K calc-alkalic and alkalic volcanism in eastern Chihuahua, Mexico: Geology and geochemistry of the Benavides-Pozos area

The Benavides-Pozos area of eastern Chihuahua, Mexico, is composed of a field of mid-Tertiary lavas and ash-flow tuffs with a composite thickness of ∼1 km. This volcanic field contains some of the easternmost, arc-related volcanic rocks in northern Mexico. The oldest volcanic rocks in Benavides-Pozos are volumetrically minor, undated, alkalic basalts that are interbedded with Tertiary clastic sedimentary rocks. Calc-alkalic rocks ranging in age from ∼34 to 30 m.y. overlie these basalts. Rocks of the calc-alkalic suite are predominantly silicic in composition, although intermediate and mafic rocks are also present. In areas adjacent to Benavides-Pozos, the calc-alkalic rocks are overlain by a chemically distinct, “ferroaugite-rhyolite,” ash-flow tuff ∼28 m.y. old. This unit is in turn overlain by extension-related alkalic basalts dated between 26 and 17 Ma. The volumetrically dominant calc-alkalic-suite rocks are high-K (K 57.5 = 3.2), and rocks have initial 87 Sr/ 86 Sr ratios that range from 0.7036 to 0.7070 and e Nd of about +1.5 to −2.2. Petrogenetic processes inferred for generation of the calc-alkalic basalt to rhyolite series include fractionation of mantle-derived basalts coupled with minor to moderate amounts of assimilation of lower crust, magma mixing (especially among intermediate magmas), low-pressure fractional crystallization, and possible upper-crustal interaction. The andesitic and dacitic lavas show considerably more mineralogic and isotopic evidence for mixing and crustal interaction than do the voluminous rhyolitic ash-flow tuffs. Isotopic, trace-element, and mineralogic data demonstrate that mixing of basalt and rhyolite was not the process responsible for genesis of the intermediate calc-alkalic rocks. Assimilation-fractional crystallization modeling of 87 Sr/ 86 Sr suggests that the most contaminated andesites and dacites contain ∼25% crustal component.
PRIMAL FATHERHOOD AND PRIMAL RAGE

Fatherhood may unconsciously activate repudiated identifications with patriarchal primal fathers in men with progressive social values. These men may consciously cultivate an image of themselves as rebellious nonconformists. These men may wish to raise children who are fiercely independent just like them. Yet when these rambunctious children challenge paternal authority, these men may become enraged because their unconscious identification with the primal father has been threatened. These men may be referred to treatment for problems of anger management. They tend to unconsciously re-create and enact their conflicted and enraging relationship with the primal father in their relationship with the therapist.
The Impact of a Medical Procedure Service on Patient Safety, Procedure Quality and Resident Training Opportunities

BACKGROUND At some academic hospitals, medical procedure services are being developed to provide supervision for residents performing bedside procedures in hopes of improving patient safety and resident education. There is limited knowledge of the impact of such services on procedural complication rates and resident procedural training opportunities.
Signaling by wingless in Drosophila

Wingless, a member of the Wnt gene family, is an essential gene for segmentation in Drosophila, and is also involved in many other patterning events. The gene encodes a secreted protein that can regulate gene expression in adjacent cells. Recently, significant progress has been made in elucidating the signal transduction pathway of wingless, mainly by genetic experiments but increasingly also at the biochemical level. While many components of wingless signaling, in particular a receptor, remain to be identified, our current understanding of wingless pathway is more advanced than that of other Wnt genes. We will give an overview of the various roles of wingless in development, and we will then summarize the wingless signaling pathway as it has emerged from genetic and biochemical studies. Where appropriate, wingless signaling will be compared to the activity of vertebrate Wnt proteins.
Is Mercury Increasing in the Atmosphere? The Need for an Atmospheric Mercury Network (Amnet)

Mercury uses in human endeavors will lead to a general, though variable, volatilization of Hg. Current estimates for anthropogenic interferences range from about 50 to 75% of the total annual Hg emissions to the atmosphere. Recent modeling suggests that the present atmospheric Hg burden has increased by a factor of 3 during the last 100 years with a current rate of increase of about 0.6% yr-1 (ca. 0.0 lng m-3yr-1). This impact, which is significant, can be examined and assessed empirically. To date, however, atmospheric Hg programs have not employed an experimental design sufficient to account for short time scale atmospheric Hg variations of natural and anthropogenic origin, and to resolve the long term temporal pattern. I am proposing an international research program, AMNET, or Atmospheric Hg Network, to address the important question, “Is Hg increasing in the atmosphere?” AMNET would examine temporal and spatial variations in atmospheric Hg and assess the influence of natural and anthropogenic sources on the global atmospheric Hg cycle. This program requires international support and cooperation. The experimental design of AMNET would follow the successful Atmospheric Lifetime Experiment Program (ALE), which examined the contemporary temporal changes in the atmospheric concentrations of the freons, methyl chloroform, carbon tetrachloride, and nitrous oxide. Following the ALE design, AMNET sampling stations would be maintained in both hemispheres and at sites free from strong local pollution sources of Hg (e.g., remote islands). Measurements would be made for a period of three to five years. The precision and accuracy of the Hg° determinations must be ≥ 1%. The accurate resolution of the variability and secular trends in the atmospheric Hg burden can provide: (1) a direct quantitative assessment of the scale to which anthropogenic processes are affecting the natural biogeochemical cycling of Hg; (2) an essential refinement and constraint currently lacking in mass balance models; (3) an enhanced knowledge of the behavior of Hg in the atmosphere, and (4) an accurate data base required for global circulation atmospheric chemical Hg models.
Stationary, dynamical, and chaotic states of the two-dimensional damped Kuramoto-Sivashinsky equation

The long-time behavior of the two-dimensional damped Kuramoto-Sivashinsky equation is studied numerically in the large-aspect-ratio limit. The equation is shown to lead to three states depending on the magnitude of a damping parameter $\ensuremath{\alpha}$. At large, intermediate, and small values of $\ensuremath{\alpha}$, the equation leads respectively to hexagonal, breathing hexagonal, and disordered states. The disordered phase is chaotic in both space and time, consistent with spatiotemporal chaos. The transitions between these states are examined using standard statistical measures.
Toward an Emancipation of the “Weaker Sense”:

Listening: An introduction to the perception of auditory events, by Stephen Handel. Cambridge, MA: MIT Press, 1989. 597 pp. $39.95. Auditory scene analysis: The perceptual organization of sound, by Albert S. Bregman. Cambridge, MA: MIT Press, 1990. 773 pp. $55.00. Cognitive foundations of musical pitch, by Carol L. Krumhansl. New York: Oxford University Press, 1990. 307 pp. $45.00 PSYCHOLOGICAL SCIENCE
Insulin resistance is associated with a modest increase in inflammation in subcutaneous adipose tissue of moderately obese women

Aims/hypothesis We have previously described differences in adipose cell size distribution and expression of genes related to adipocyte differentiation in subcutaneous abdominal fat obtained from insulin-sensitive (IS) and -resistant (IR) persons, matched for degree of moderate obesity. To determine whether other biological properties also differ between IR and IS obese individuals, we quantified markers of inflammatory activity in adipose tissue from overweight IR and IS individuals.
A fluxless fabrication process producing Sn-rich Bi–Sn joints with high melting temperature

Abstract A fluxless bonding process to produce tin-rich bismuth–tin solder joints is presented. The process was designed using Sn–Bi multilayer structure deposited in high vacuum to inhibit oxidation and to achieve the fluxless feature. The composition was chosen to be tin-rich, 95.0 wt.% Sn and 5.0 wt.% Bi, to achieve a solidus temperature significantly higher the 139 °C eutectic temperature of the 57Bi–43Sn eutectuic alloy. The resulting joints were imaged with a scanning acoustic microscope (SAM) and shown to be nearly void-free. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy were used to study the microstructure and compositions of the joints. The measured joint thickness was 4.1 μm. SAM and EDX results indicate that the solder joint consists of (β-Sn) matrix embedded with small grains of (Bi) solid solution phase. The melting temperature of the joint was measured to be 210–215 °C, as expected from the designed composition. The fluxless feature of this process gives the packaging community another process to consider for use in devices and packages where the use of flux is prohibited, such as some biomedical, MEMs, fiber optical and photonic devices.
Can there be science-based precaution?

'Science-based precaution' is possible in logic if not in politics, and should be a normal part of risk management. It should balance the risks and benefits of innovation, or equivalently, specify the price one is willing to pay to avoid risk. The Precaution Principle states that the absence of scientific proof does not preclude precautionary action—or, in its stronger version, that it requires such action. This principle is a useful counterweight to the insistence on rigorous scientific proof, but focuses on costs and risks to the exclusion of benefits. It expresses 'look before you leap', but not 'nothing ventured, nothing gained'. To facilitate adaptive management, we propose a complementary principle: 'precautionary action should not unreasonably interfere with innovation that promises major benefits, until its dangers and benefits are well understood'. In international trade law, we propose that scientific evidence presented in support of discriminatory measures that would otherwise violate the world trade regime—such as the de facto European Union moratorium on importing genetically modified crops—be required to suffice to support a 'reasonable belief' of danger to human health or the environment.
Breast Surgery: Minimally Invasive Diagnosis and Treatment

The increasingly large proportion of elderly women in the United States population carries a disproportionate burden of breast cancer. The advent of minimally invasive surgical techniques applicable to breast disease has brought new opportunities to diagnose and treat breast cancer in the older population. This article reviews issues important to the evolving field of breast cancer management in older women: cancer risk and screening considerations, diagnosis and biopsy approaches, and surgical treatment options based on current studies and recommendations.
Skimmilk as a feed for dairy cows.

In the butter-producing areas of the United States the proper utilization of the by-products is an important economic question. M~nnesota, for example, with a total butter production of approxlmately 290,000,000 pounds annually has a total of over six billion pounds of skimmilk and buttermilk available for use on the farms and in the factories. The recommendations of agricultural authorities have been to use the dairy by-products for feeding livestock and the excellent results following this general practice are well known. In recent years the production of cream for butter manufacture has developed in regions where it is not practical to produce sufficient grain to make swine production profitable on a large scale. The farmer uses all the sl~immilk he can as feed for his pigs, calves, and chickens and still often has milk on hand. A calculation based upon census figures shows that after allowing for all the sl~immilk that can be used economically by the pigs, calves, and poultry in this state a surplus of over a billion pounds remains. Most of this is not entirely wasted but is used in excessive amounts as feed for livestock. I t is well established that the special efficiency of sl~immilk in the diet of the growing pig is due to the excellent quality of the protein which supplements the rather low quality proteins of cereals, and to a lesser extent to the mineral and vitamins content. The value per unit of
Global Electrosensory Oscillations Enhance Directional Responses of Midbrain Neurons in Eigenmannia

Eigenmannia, a genus of weakly electric fish, exhibits a specialized behavior known as the jamming avoidance response (JAR). The JAR results in a categorical difference between Eigenmannia that are...
A BACKPROJECTION-BASED ESTIMATION METHOD FOR REDUCING THE CONE-BEAM ARTIFACTS IN CIRCULAR TRAJECTORIES

Circular trajectories are commonly used in cone-beam (CB) CT. Insufficient data measurement in such a geometry induces CB artifacts in CT images. Development of an efficient algorithm to reduce this problem remains a major challenge. A backprojection-based method is proposed here. Each CB projection is analyzed in radon space via Grangeat's formula. Assuming the CB projection is taken from a parallel geometry, we extract those data in the unmeasured radon region. These data are then backprojected as in a parallel geometry to calculate a correction term, which is added to the FDK result with Hu's correction (H-FDK) to form a final reconstruction. Using a parallel geometry, this algorithm can be implemented efficiently on a projection-by-projection basis. The algorithm is evaluated using computer simulations, and the result shows that the proposed method greatly reduces the CB artifacts in the H-FDK reconstructions
Unsupervised Identifying Diagnostic Genes and Specific Phenotypes from Microarray Data

In this paper, we explore a new problem of simultaneously mining diagnostic genes and specific phenotypes from microarray data using unsupervised method. A novel type of cluster called LC-Cluster is proposed to address this problem. The idea behind the solution is motivated by recent biological discovery and origins from current bicluster model or emerging pattern, but differs substantially from either of them. We also design two efficient tree-based algorithms, namely FALCONER and E-FALCONER, to mine all such maximal clusters. Extensive experiments conducted on both several real and synthetic datasets show: (1) our approaches are efficient and effective, (2) our approaches out-perform the existing enumeration tree-based algorithm, and (3) our approaches can discover an amount of LC-Clusters, which are potentially of high biological significance.
Mastery learning of thoracentesis skills by internal medicine residents using simulation technology and deliberate practice.

BACKGROUND Thoracentesis has been identified as a core competency for hospitalists. Residency training may not provide adequate preparation to perform this procedure. OBJECTIVE Our aim was to use a thoracentesis simulation to assess graduating residents' proficiency in thoracentesis procedural skills and to evaluate the impact of an educational intervention on skill development to mastery standards. DESIGN This was a pretest–posttest mastery learning design without a control group. SETTING Participants were 40 third-year internal medicine residents in a university-affiliated program. INTERVENTION Using an observational checklist, each resident underwent baseline assessment of thoracentesis skill using a standardized clinical history, radiograph, and thoracentesis simulation. After baseline testing, residents received two 2-hour education sessions featuring a videotaped presentation and deliberate practice with the thoracentesis simulator. MEASUREMENTS Residents were retested after the intervention. Skill mastery was defined as meeting or exceeding the minimum passing score (MPS) set by an expert panel at thoracentesis posttest. Those who did not achieve the MPS had additional deliberate practice and were retested until the MPS was reached. RESULTS Performance improved 71% from pretest to posttest on the clinical skills examination. All residents met or exceeded the mastery standard. The amount of practice time needed to reach the MPS was the only predictor (negative) of posttest performance. The education program was rated highly. CONCLUSIONS A curriculum featuring deliberate practice dramatically increased the skills of residents in thoracentesis. Residents enjoy training and receiving evaluation and feedback in a simulated clinical environment. This mastery program illustrates a feasible and reliable mechanism to achieve procedural competency. Journal of Hospital Medicine 2008;3:48–54. © 2008 Society of Hospital Medicine.
Limiting attrition in longitudinal research on homeless adolescents: what works best?

The effectiveness of five tracking strategies (collateral contacts, Internet databases, driver's records, letters, and community visits) used in attempting to locate homeless and housed adolescents 4.5 years after they were first contacted was examined and compared. The study sample comprised 401 adolescents (252 homeless and 149 matched housed) from 8 counties in Southeast Michigan. Homelessness was defined as sleeping in a shelter, at a friend's home without parental permission, or on the streets for at least 1 night within 1 month before initial contact. We successfully located and interviewed 85% (n=340) of our sample at the 4.5-year time point. The most effective tracking procedure was collateral contact, which was important in locating 43% of participants in this study, followed by Internet databases (18%), community visits (11%), driver's records (6%), and letters (6%). © 2011 Wiley Periodicals, Inc.
Propagation of double Rydberg wave packets

Double Rydberg wave packets for He electronic states are propagated in time using fully quantum mechanical calculations. The wave packets are constructed so that the two electrons are simultaneously excited up to nRyd ~ 15 states and coupled to total orbital angular momentum equal to zero and to total spin equal to zero. We attempt to construct a wave packet to isolate symmetric stretch motion. Classical and quantum ideas are used to interpret several features of the time-dependent wave function. We briefly discuss some of the interesting problems that can be addressed.
On the Efficiency of Provenance Queries

While models for data provenance have been extensively studied in the literature, the efficient evaluation of the resulting provenance queries remains an open problem. Traditional query optimization techniques, like the use of general-purpose indexes, or the materialization of provenance data, fail on different fronts to address the problem. Provenance-specific optimization techniques, like the use of customized indexes, similarly prove inadequate since the techniques are bound to specific provenance models. Therefore, the need to develop generic provenance-aware techniques quickly becomes apparent.In this paper, we argue for such a generic technique in the form of a provenance index structure that can be used to efficiently evaluate provenance queries ina variety of contexts. By highlighting the limitations of existing techniques, we identify the set of key properties of the generic index, including a novel property called duality which guarantees that the single index can evaluate both backward provenance queries (which data items from a set I are associated with an item from set O) and forward provenance queries (which items from O are associated with an item from I).
Re‐imagining Leviathan: Schmitt and Oakeshott on Hobbes and the problem of political order

Both Michael Oakeshott and Carl Schmitt were deeply preoccupied with what Oakeshott called ‘the experience of living in a modern European state’; both felt that the state's proper origins and trajectory had not been grasped, that proper statehood had profoundly been put into doubt in the twentieth century, and that state authority and legitimacy needed to be shored up in an age of ‘mass politics’. Not surprisingly, then, both developed their conception of political association with and sometimes against Hobbes. Both profoundly disagreed with conventional readings of Hobbes as propounding a materialist or ‘scientistic’ philosophy. Most importantly, both consistently de‐emphasized, or entirely discounted, Hobbes's contractualism – they cut off any possible route from Hobbes's thought to liberal theories of explicit or tacit consent. Instead, both stressed a concern with the cultural preconditions of political order. Oakeshott's civil association turned out to be an idealized picture of modern European indiv...
Organizational Corruption as Theodicy

This paper draws on Weber’s theodicy problem to define organizational corruption as the emerging discrepancy between experience and normative expectation. Theodicy describes the attempts to explain this discrepancy. The paper presents four normative principles enlisted by observers to respond to perceived corruption: moral dilemma, detachment, systematic regulation, and normative controls. Consistent with social construction, these justifications work to either reaffirm or challenge prevailing social norms in the face of confusing events. An exemplar case involves perceived corruption in the business of mountain climbing as represented through the 1996 Mt. Everest climbing disaster. The events illustrate how theodicy informs descriptive accounts of corruption and expose two limitations of normative models of ethics.