cssi/SciSciGPT-SciSciNet huggingface dataset:
Hidden Symmetries in Real and Theoretical Networks

Abstract Symmetries are ubiquitous in real networks and often characterize network features and functions. Here we present a generalization of network symmetry called latent symmetry, which is an extension of the standard notion of symmetry on networks, which can be directed, weighted or both. They are defined in terms of standard symmetries in a reduced version of the network. One unique aspect of latent symmetries is that each one is associated with a size, which provides a way of discussing symmetries at multiple scales in a network. We are able to demonstrate a number of examples of networks (graphs) which contain latent symmetry, including a number of real networks. In numerical experiments, we show that latent symmetries are found more frequently in graphs built using preferential attachment, a standard model of network growth, when compared to non-network like (Erdős–Renyi) graphs. Finally we prove that if vertices in a network are latently symmetric, then they must have the same eigenvector centrality, similar to vertices which are symmetric in the standard sense. This suggests that the latent symmetries present in real-networks may serve the same structural and functional purpose standard symmetries do in these networks. We conclude from these facts and observations that latent symmetries are present in real networks and provide useful information about the network potentially beyond standard symmetries as they can appear at multiple scales.
Boundary-Spanning in Social Movements: Antecedents and Outcomes

Social movement scholarship has increasingly sought to understand the relational dynamics of internal movement activity, from investigating the factors that enable movement coalitions to analyzing the trade-offs of organizational hybridity. We bring these and other related phenomena together under the label of boundary-spanning processes. Specifically, we organize research on boundary-spanning in social movements by identifying three types of boundaries that have symbolic significance as categorical demarcations: (a) issue and identity boundaries, (b) organizational boundaries, and (c) tactical boundaries. We then elucidate the tension in work that has examined how each form of boundary-spanning either promotes or hinders the realization of three important movement outcomes: (a) mobilization, (b) internal movement solidarity and scope, and (c) external social and political change. We relate our three types of boundary-spanning to these three types of outcomes in an organizing framework to locate future op...
Three-dimensional Cardiomyocytes Structure Revealed by Diffusion Tensor Imaging and Its Validation Using a Tissue-Clearing Technique

We characterized the microstructural response of the myocardium to cardiovascular disease using diffusion tensor imaging (DTI) and performed histological validation by intact, un-sectioned, three-dimensional (3D) histology using a tissue-clearing technique. The approach was validated in normal (n = 7) and ischemic (n = 8) heart failure model mice. Whole heart fiber tracking using DTI in fixed ex-vivo mouse hearts was performed, and the hearts were processed with the tissue-clearing technique. Cardiomyocytes orientation was quantified on both DTI and 3D histology. Helix angle (HA) and global HA transmurality (HAT) were calculated, and the DTI findings were confirmed with 3D histology. Global HAT was significantly reduced in the ischemic group (DTI: 0.79 ± 0.13°/% transmural depth [TD] and 3D histology: 0.84 ± 0.26°/%TD) compared with controls (DTI: 1.31 ± 0.20°/%TD and 3D histology: 1.36 ± 0.27°/%TD, all p < 0.001). On direct comparison of DTI with 3D histology for the quantitative assessment of cardiomyocytes orientation, significant correlations were observed in both per-sample (R2 = 0.803) and per-segment analyses (R2 = 0.872). We demonstrated the capability and accuracy of DTI for mapping cardiomyocytes orientation by comparison with the intact 3D histology acquired by tissue-clearing technique. DTI is a promising tool for the noninvasive characterization of cardiomyocytes architecture.
Design of a Three-Dimensional Global Atmospheric Prediction Model by a Variational Method

ABSTRACT Kasahara, A., 1985. Design of a three-dimensional global atmospheric prediction model by a variational method. Proc. Int. Symp. on Variational Methods in Geosciences This paper presents the formulation of a three-dimensional global atmospheric prediction model, in which the dependent variables are expressed in terms of the three—dimensional normal mode functions and the Galerkin method is applied to obtain a set of ordinary differential equations with respect to time for the expansion coefficients.
Structural and Functional Polarity of The Blood-Brain Barrier

The blood-brain barrier has often been considered a simple membrane that forms an impermeable wall to polar solutes while permitting lipid-soluble compounds to pass. Over the past two decades, our understanding of blood-brain barrier function has been advanced by recognition of the importance of carrier-mediated transport processes which facilitate the permeation of selected polar compounds across this lipid barrier. In most cases, however, kinetic models of these transport systems have considered only a single transport step in the movement of a compound from blood to brain. These single-membrane models are obviously oversimplifications since the structure which forms the blood-brain barrier, the brain capillary endothelium, is a monolayer of interconnected cells with separate membrane surfaces facing the blood and the brain. The two opposing plasma membranes of the endothelial cell need not have identical permeability properties. Thus, a comprehensive representation of the blood-brain barrier must take into account the two separate membranes that solutes encounter as they move between blood and brain as well as the cytoplasm of the endothelial cell which may contain enzymes capable of reacting with the solutes while they are in transit through the cell.
Adolescents and Asthma

Adolescence is a time of rapid development where children undergo marked physical, intellectual, and psychosocial growth. This transitional period between childhood and adulthood usually encompasses the second decade of life, although its onset and duration can vary. In children with chronic illness including asthma, adolescence is an important period for establishing proper self-management and coping skills. In fact, asthma is the most common chronic illness of adolescence (Mannino et al. 1998; 2002). The capacity to manage one’s disease is an essential component of asthma care and is influenced by adolescents’ increasing maturity; growing need for independence and engagement in health risk behaviors. Consequently, effective communication between the adolescent patient, their family, school and health care provider is essential to achieve optimal control. This chapter will review these influences on asthma self-management and discuss their implications for effective patient-provider communication.
Chapter 9 – Sky-Imaging Systems for Short-Term Forecasting

This chapter discusses the use of ground-based visible wavelength imagery for short-term forecasting of solar-power output. It begins with selected applications of short-term forecasting to both transmission- and distribution-scale generation. The hardware used in sky-imaging systems is next presented, providing technical and historical information on system optics and sensory equipment (e.g., charge-coupled devices). A high-quality sky-imaging system designed by the authors (the USI) is then briefly examined. The core of the chapter consists of describing sky-imagery analysis techniques, followed by their application to a large solar-power plant. The techniques used to detect clouds, determine their height, and estimate their motion are explained. Application of these methods to generate a power forecast is presented in a case study of a 48 MW solar-power plant, for which a week of data was analyzed. The results are discussed and ideas for improvement are presented. Finally, recommendations for advancing ground-based visible-wavelength imagery and forecast performance are presented.
The Influence of Isomeric States on Independent Fission Product Yields

A simple one-parameter model is presented for calculating the distribution of independent yield strength between ground and isomeric states of primary fission products formed by neutron-induced fission of actinide nuclei. Yield branching ratios are calculated as a function of neutron energy (thermal, fast, and 14-MeV) for 33 cases that span 144 fission product nuclei having isomeric states with known spins.
Evaluating the Effect of the Within-Flock Disease Transmission Rate on Premovement Active Surveillance in Low Pathogenicity Avian Influenza-Infected Flocks.

Premovement active surveillance for low pathogenicity avian influenza (LPAI) may be a useful risk management tool for producers during high-risk periods, such as during an LPAI outbreak, or in areas where there is a recognized high risk for LPAI spread. The effectiveness of three active-surveillance protocols in mitigating LPAI spread risk related to the movement of spent broiler breeders to processing was evaluated in this study. Each protocol differed in the amount of real-time reverse transcription polymerase chain reaction (RRT-PCR) and serology testing conducted. The protocols were evaluated with the use of disease transmission and active surveillance simulation models parametrized specifically for broiler breeders to estimate the probability of detecting a current or past infection and the mean proportion of infectious birds at the time of sampling in houses where the infection remains undetected at the time of movement after exposure to the virus. The two values were estimated considering flock infection for 1–28 days prior to the day of scheduled movement. A distribution for the adequate contact rate, a parameter that controls the rate of within-house spread in the disease transmission model, was estimated for this study by a novel forward simulation approach with the use of serology data from three LPAI-infected broiler breeder flocks in the United States. The estimated distribution suggests that the lower contact-rate estimates from previously published studies were not a good fit for the serology results observed in these U.S. flocks, though considerable uncertainty remains in the parameter estimate. The results for the probability of detection and mean proportion of infectious, undetected birds suggest that RRT-PCR testing is most beneficial during the early stages of infection postexposure, and serology testing is most beneficial during the later stages of infection, results that are expected to hold for flocks outside the United States as well. Thus, protocols that combine RRT-PCR and serology testing can offer a more balanced approach with good performance over the disease course in a flock.
Idioms: Humans or Machines, It’s All About Context

Expressions can be ambiguous between idiomatic and literal interpretation depending on the context they occur in (“sales hit the roof” vs “hit the roof of the car”). Previous studies suggest that idiomaticity is not a binary property, but rather a continuum or the so-called “scalar phenomenon” ranging from completely literal to highly idiomatic. This paper reports the results of an experiment in which human annotators rank idiomatic expressions in context on a scale from 1 (literal) to 4 (highly idiomatic). Our experiment supports the hypothesis that idioms fall on a continuum and that one might differentiate between highly idiomatic, mildly idiomatic and weakly idiomatic expressions. In addition, we measure the relative idiomaticity of 11 idiomatic types and compute the correlation between the relative idiomaticity of an expression and the performance of various automatic models for idiom detection. We show that our model, based on the distributional semantics ideas, not only outperforms the previous models, but also positively correlates with the human judgements, which suggests that we are moving in the right direction toward automatic idiom detection.
The Supreme Court and Freedom of Speech, 2003–2004

(2004). The Supreme Court and Freedom of Speech, 2003–2004. Free Speech Yearbook: Vol. 41, No. 1, pp. 142-150.
Characterization of methylation of rat liver cytosolic glutathione S-transferases by using reverse-phase h.p.l.c. and chromatofocusing.

Glutathione S-transferase (GST) subunits in rat liver cytosol were separated by reverse-phase h.p.l.c.; five major proteins were isolated and identified as subunits 1, 2, 3, 4 and 8. F.p.l.c. chromatofocusing resolved the affinity-purified GST pool into nine different isoenzymes. The five basic (Alpha class) dimeric peaks of GST activity were 1-1, 1-2a, 1-2b, 2-2a and 2-2b. Reverse-phase h.p.l.c. analysis revealed that subunit 8 was also present in the protein peaks designated 1-1, 1-2a and 1-2b. The four neutral (Mu class) isoenzymes were 3-3, 3-4, 3-6 and 4-4. The GST pool was methylated in vitro before reverse-phase h.p.l.c. or f.p.l.c. chromatofocusing. Chromatofocusing indicated that the Mu class isoforms (3-3, 3-4 and 4-4) were the primary GSTs methylated, and h.p.l.c. analysis confirmed that subunits 3 and 4 were the major methyl-accepting GST subunits. The addition of calmodulin stimulated the methylation in vitro of GST isoenzymes 3-3, 3-4 and 4-4 by 3.0-, 7.5- and 9.9-fold respectively. Reverse-phase h.p.l.c. also indicated that only the methylation of GST subunits 3 and 4 was stimulated by calmodulin. Basic GST isoenzymes were minimally methylated and the methylation was not enhanced by calmodulin. Investigation of the time course of methylation of GST subunits 3 and 4 indicated that at incubation times less than 4 h the methylation of both Mu class subunits was stimulated by calmodulin, and that under such conditions subunit 4 was the preferred substrate. In contrast, there was essentially no calmodulin-stimulated methylation at incubation times of 4 or 6 h, and the methylation of subunit 3 was predominant. Kinetic parameters at 2 h of incubation were determined in the presence and in the absence of calmodulin. The addition of calmodulin doubled the Vmax. for methylation of both subunits 3 and 4 and decreased the Km of subunit 4 for S-adenosyl-L-methionine 3.6-fold. Finally, methylation was substoichiometric and after 6 h of incubation ranged from 2.8 to 7.6% on a mole-to-mole basis for subunits 4 and 3 respectively.
EDUCATION AND GOOD GOVERNANCE: A PSYCHO-POLITICAL ANALYSIS

Nigeria today is facing a serious psycho-political and economic crisis. The time demands that scholars and practitioners should think a loud and come out with suggestions regarding the possible solutions to our problems. This paper is design to review the present psycho-political and economical conditions in the country and then goes on to argue that for a quick recovery from the depression there is the need for all Nigerians to develop what has been called the mind of good governance and this type of mind can only be effectively inculcated through the educational system in the country. It goes on to state in this direction that the school curriculum and the method of imparting any desirable knowledge and skill should have built in challenges. So that the products of the system would be able to face more squarely the hard problems of existence as are witnessed today in the country.
Step 3 of EBP: Part 3—Meta-analysis and Systematic Reviews, Aggregating Research Results

Step 3 of the EBP process centers on evaluating the quality and relevance of research results. This chapter examines the aggregation and evaluation of multiple research studies using a method called the systematic review. Systematic reviews locate and combine the results of multiple studies using clearly defined and transparently reported standards. The statistical results of studies are aggregated and compared using a set of techniques called meta-analysis. As terminology has evolved in this area, the shared and distinct features of systematic reviews and meta-analyses are carefully defined and distinguished. The standards for Cochrane Collaboration quality reviews are identified. A Cochrane systematic review is analyzed in detail to show the strength and limitations of such publications.
Artificial Intelligence, Artists, and Art: Attitudes Toward Artwork Produced by Humans vs. Artificial Intelligence

This study examines how people perceive artwork created by artificial intelligence (AI) and how presumed knowledge of an artist's identity (Human vs. AI) affects individuals’ evaluation of art. Drawing on Schema theory and theory of Computers Are Social Actors (CASA), this study used a survey-experiment that controlled for the identity of the artist (AI vs. Human) and presented participants with two types of artworks (AI-created vs. Human-created). After seeing images of six artworks created by either AI or human artists, participants (n = 288) were asked to evaluate the artistic value using a validated scale commonly employed among art professionals. The study found that human-created artworks and AI-created artworks were not judged to be equivalent in their artistic value. Additionally, knowing that a piece of art was created by AI did not, in general, influence participants’ evaluation of art pieces’ artistic value. However, having a schema that AI cannot make art significantly influenced evaluation. Implications of the findings for application and theory are discussed.
Racial disparities and outcomes of left ventricular assist device implantation as a bridge to heart transplantation

AIMS This study investigated outcomes after continuous flow left ventricular assist device (CF-LVAD) implantation as bridge to heart transplantation (BTT) in advanced heart failure patients stratified by race. METHODS AND RESULTS De-identified data from the United Network for Organ Sharing database was obtained for all patients who had a CF-LVAD as BTT from 2008 to 2018. Patients were stratified into four groups on the basis of ethnicity [Caucasian, African American (AA), Hispanic, and others (Asian, Pacific Islanders, and American Indian)]. Outcomes investigated were waitlist mortality or delisting and post-transplant 5 year survival. Cox proportional hazards modelling was used to identify independent predictors of waitlist mortality or delisting and post-transplant survival. We used Kaplan-Meier survival curves and the log-rank test to estimate and compare survival among groups. A total of 14 234 patients who had CF-LVADs as BTT were identified. Of these, 64% (n = 9058) were Caucasians, 26% (n = 3677) were AA, 7% (n = 997) were Hispanic, and 3% (n = 502) had a different race. Compared with Caucasian, AA, and Hispanic patients had higher body mass indexes and a lower level of education and are more likely to be public health insurance beneficiaries. There was a significantly lower incidence of transplantation in AAs compared with Caucasians, Hispanics, and others at 12, 24, and 60 months, respectively (Gray's test, P < 0.001). The AA race was a significant predictor of waitlist mortality or delisting owing to worsening clinical status [hazard ratio, 95% confidence interval: 1.10 (1.01 to 1.16; P < 0.001)]. Among those who were successfully BTT, risk-adjusted post-transplant survival was similar among the four groups (log-rank test: P = 0.589). CONCLUSIONS Disparities exist among different races that receive a CF-LVAD as a BTT. These disparities translate into increased waitlist morbidity and mortality but not long-term post-transplant survival among those who successfully reach transplant.
When Actions Speak Louder Than Words - Racism and Sickle Cell Disease.

Racism and Sickle Cell Disease As medical leaders around the United States issue statements denouncing racial injustice and calling for the dismantling of racism, we must ensure that these pledges ...
Impacts of insect consumption on human health

Edible insects represent an understudied food resource that may promote human health. They characteristically contain ample protein, healthy fatty acids, minerals, and vitamins, and have been toute...
Verbal Ability, Behavior Problems, and Mother-Child Relationship Quality in Autism Spectrum Disorder.

This study examined differences in mother–child relationship quality and parent-rated child behavior problems based on child verbal status (i.e., minimally verbal versus verbal) in mothers and their adolescent and adult children with autism spectrum disorder (n = 219 dyads; child Mage = 25.38 years, SD = 10.22). Relationship quality was assessed via parent-reported maternal burden and mother–child closeness, and coded speech samples ascertaining maternal critical and positive remarks regarding the child. Groups did not differ in relationship quality. The verbal group was more likely to display disruptive and socially inappropriate behaviors, but otherwise the groups did not differ in behavior problems. Verbal status moderated the relationship between behavior problems and negative (maternal burden, critical remarks) but not positive (mother–child closeness, positive remarks) aspects of relationship quality.
Teaching Antenatal Counseling Skills via Video Conference

Neonatologists provide counseling to expectant parents to prepare them for the birth and subsequent medical care that their extremely preterm, or otherwise medically complex newborn may require. The skills required to conduct these sensitive conversations are often taught to neonatology trainees via direct observation or simulated scenarios in advance of counseling actual patients. This technical report details how we taught antenatal counseling skills to junior neonatal-perinatal medicine (NPM) fellows via video conferencing during the coronavirus disease 2019 (COVID-19) pandemic. This approach could be used to effectively prepare future trainees to perform antenatal counseling.
Impact of COVID-19 Among Immigrant and Communities of Color Living with HIV in Oregon, 2020: Two Pandemics Rooted in Racism.

Over 8100 people living with HIV (PLWH) in Oregon are at risk of acquiring COVID-19, and communities of color are disproportionately impacted by both COVID-19 and HIV. This study identifies factors associated with a positive COVID-19 test among PLWH in Oregon, with the goal of promoting health equity. We probabilistically linked COVID-19 laboratory results with laboratory-confirmed HIV cases. Crude and adjusted risk ratios of having a COVID-19 diagnosis were calculated for each covariate. Almost 6% of the 2390 PLWH tested for COVID-19 had a positive COVID-19 result. PLWH with positive results tended to identify as American Indian/Alaska Native or Hispanic/Latinx. Younger (age < 50) immigrant PLWH were more than twice as likely to have a positive COVID-19 result than did older (age ≥ 50) US-born PLWH. The pandemic has magnified disparities among American Indian/Alaska Native, Latinx, and younger immigrant PLWH. Dismantling institutional racism and redistributing power are strategies that could be considered to help reduce health disparities.
Influence of Pre-Season Antibodies against Influenza Virus on Risk of Influenza Infection among Health Care Personnel.

BACKGROUND The association of hemagglutination inhibition (HAI) antibodies with protection from influenza among healthcare personnel (HCP) with occupational exposure to influenza viruses has not been well-described. METHODS The Respiratory Protection Effectiveness Clinical Trial was a cluster-randomized, multi-site study that compared medical masks to N95 respirators in preventing viral respiratory infections among HCP in outpatient healthcare settings for 5,180 participant-seasons. Serum HAI antibody titers before each influenza season and influenza virus infection confirmed by polymerase chain reaction were studied over four study years. RESULTS In univariate models, the risk of influenza A(H3N2) and B virus infections was associated with HAI titers to each virus, study year, and site. HAI titers were strongly associated with vaccination. Within multivariate models, each log base 2 increase in titer was associated with 15%, 26% and 33-35% reductions in the hazard of influenza A(H3N2), A(H1N1) and B infections, respectively. Best models included pre-season antibody titers and study year, but not other variables. CONCLUSIONS HAI titers were associated with protection from influenza among HCP with routine exposure to patients with respiratory illness and influenza season contributed to risk. HCP can be reassured about receiving influenza vaccination to stimulate immunity.
Characterization of intracellular survival of Mycobacterium avium subspecies paratuberculosis in J774 murine macrophages

Mycobacterium avium subspecies paratuberculosis (M. a. ptb) is the causative agent of Johne's disease, a progressive diarrheal disease of wild and domestic ruminants. One mechanism developed by several pathogenic species of mycobacteria for intracellular survival is inhibition of acidification of the phagosomal compartment in which they reside. We hypothesize that following phagocytosis M a. ptb resides within a phagosomal compartment that has reduced ability to acidify. To test this hypothesis, macrophages containing live M. a. ptb were compared to macrophages containing killed M a. ptb. Zymosan A, or the non-pathogenic species Mycobacterium smegmatis {M. smegmatis) in J774 monolayers at 2, 6, and 24 hours postinfection periods. Colocalization of fluorescent signals generated by direct conjugation of bacteria with fluorescein isothiocyanate (FITC) and labeling acidified compartments within macrophages with Lysotracker Red, was identified by laser confocal microscopy. Colocalization was also evaluated after addition of the specific V-ATPase inhibitor Bafilomycin Ai. In addition, acidification of the phagosome containing M. a. ptb was evaluated by transmission electron microscopy following labeling of acidified compartments with the weakly basic amine (3-(2,4-dinitroanilino)-3 '-amino-Nmethyldipropylamine (DAMP) with subsequent inununogold labeling. The results of this
Detection and Clinical Associations of Autoantibodies to Myeloid Granular Proteins

At the end of the third International ANCA Workshop in Washington D.C., USA, in 1990 it was concluded, that antineutrophil cytoplasmic autoantibodies (ANCA), that produce a cytoplasmic fluorescence pattern on ethanol fixed granulocytes (c-ANCA) usually react with proteinase 3 (PR 3), whereas ANCA that produce a nuclear to perinuclear fluorescence pattern on ethanol fixed granulocytes (p-ANCA) usually react with myeloperoxidase (MPO) (1). p-ANCA, however, may also -infrequently-react with human leukocyte elastase (HLE), lactoferrin (LF), and/or cathepsin G (CG) (1). Therefore, a positive p-ANCA test should always be followed by antigen-specific assays (2).
FLOWS THROUGH SEQUENTIAL ORIFICES WITH HEATED SPACER-RESERVOIRS

Flow rates and pressure thermal profiles for two phase choked flows of fluid nitrogen were studied theoretically and experimentally in a four sequential orifice configuration. Both theory and experimental evidence demonstrate that heat addition in the first spacer-reservoir adjacent to the inlet orifice is most effective in reducing the flow rate and that heat addition in the last spacer-reservoir is least effective. The flows are choked at the exit orifice for large spacings and at the inlet orifice for small spacings. The moderate addition of heat available for this experiment did not materially alter this result for large spacings; however, significant heat addition for the small spacings tended to shift the choke point to the exit orifice. Nitrogen is used as the working fluid over a range of states from liquid to gas with a reduced inlet stagnation pressure range to P sub r, o = 2.
Dynamic Stereo Triangulation for Robot Juggling

We have devised a nonlinear state estimator to recover the position and velocity of falling balls directly from the image plane measurements of a stereo camera pair. Avoiding an explicit triangulation step in the estimation procedure allows the continued use of one camera's data even when the other camera may be occluded. This paper presents a rudimentary analysis, some simulation results, and data from a working implementation that suggest the potential utility of the idea.
Antibody class switch recombination : Roles for switch sequences and mismatch repair proteins

Mechanisms and targeting of antibody class switch DNA recombination are reviewed. Particular emphasis is on the roles for the DNA sequences comprising switch (S) regions, including the S-region tandem repeats, and on the roles of proteins that are involved in both DNA mismatch repair and in class switch recombination.
Bacteriophage T4 head morphogenesis. V. The role of DNA synthesis in maturation of an intermediate in head assembly.

Abstract On the basis of metabolic-inhibitor studies it was found that maturation of T4 head intermediates, which had accumulated in tsC9 (gene 49) mutant infected cells, was apparently dependent on continued DNA synthesis. This requirement for DNA synthesis in head maturation was confirmed by using a gene 43 mutant (tsP36) blocked in the enzyme, T4 DNA polymerase. In temperature shift-up experiments with tsP36-infected cells it was found as previously reported ( Luftig and Ganz, 1972 ) that 300s particles accumulated when enzyme synthesis was halted. These latter structures appear identical to the gene 49-defective intermediates since, when isolated, they both: (i) had an average sedimentation coefficient of 310 ± 20s and a nucleoprotein density of 1.34 g/cc; (ii) had the major capsid polypeptide in a cleaved state; (iii) were quantitatively rescued (to a >50% level in 40 min) after the mutant-blocked function was recovered, and (iv) showed a reduced ability to convert to phage when an inhibitor of DNA synthesis such as fluorodeoxyuridine (FUdR) was added at the time the function was rescued. The maturation of rapidly labeled 300s wild-type (T4D+) head intermediates was also found to be sensitive to inhibitors of DNA synthesis. Upon isolation these heads had the same properties as the above gene 49 and gene 43 mutant-defective intermediates. This strongly suggests that DNA synthesis is a normal requirement for maturation of a T4 capsid intermediate, whose properties are defined above.
Ultrafast Chemical Exchange Seen with 2D Vibrational Echoes

Chemical exchange of species among different molecules occurs in many reactions. For solvent reactions, this exchange can occur on a time scale of picoseconds and is impossible to follow with conventional methods such as nuclear magnetic resonance. In his Perspective, [Dlott][1] discusses results reported in the same issue by [ Zheng et al. ][2] in which infrared laser pulses were used to observe chemical exchange reactions as phenol molecules formed solvent complexes in benzene liquid on a time scale of picoseconds. The method opens the possibility of a general method for studying fast chemical exchange in aqueous solvents and biomolecules. [1]: http://www.sciencemag.org/cgi/content/full/309/5739/1333 [2]: http://www.sciencemag.org/cgi/content/short/309/5739/1338
Demixing of water and ethanol causes conformational redistribution and gelation of the cationic GAG tripeptide.

The cationic tripeptide GAG undergoes three conformational changes in binary mixtures of water and ethanol. At 17 mol% of ethanol conformational sampling is shifted from pPII towards β-strands. A more pronounced shift in the same direction occurs at 40 mol%. At ca. 55 mol% of ethanol and above a peptide concentration of ca. 0.2 M the ternary peptide–water–ethanol mixture forms a hydrogel which is comprised of unusually large crystalline like non-β sheet fibrils forming a sample spanning matrix.
Feature-based alignment of volumetric multi-modal images

This paper proposes a method for aligning image volumes acquired from different imaging modalities (e.g. MR, CT) based on 3D scale-invariant image features. A novel method for encoding invariant feature geometry and appearance is developed, based on the assumption of locally linear intensity relationships, providing a solution to poor repeatability of feature detection in different image modalities. The encoding method is incorporated into a probabilistic feature-based model for multi-modal image alignment. The model parameters are estimated via a group-wise alignment algorithm, that iteratively alternates between estimating a feature-based model from feature data, then realigning feature data to the model, converging to a stable alignment solution with few pre-processing or pre-alignment requirements. The resulting model can be used to align multi-modal image data with the benefits of invariant feature correspondence: globally optimal solutions, high efficiency and low memory usage. The method is tested on the difficult RIRE data set of CT, T1, T2, PD and MP-RAGE brain images of subjects exhibiting significant inter-subject variability due to pathology.
Distal Lobe of the Pilifer: An Ultrasonic Receptor in Choerocampine Hawkmoths

Evidence is presented for a novel mechanism mediating the auditory sense in the Choerocampinae (Lepidoptera: Sphingidae). Vibrations in the scale-free medial wall of the enlarged labial palp segment are transmitted by contact to the distal lobe of the pilifer, a derivative of the labrum, and are there transduced into afferent impulses in the labral nerve.
Surfactant Effects on Residual Water and Oil Saturations in Porous Media

A series of soil column tests was performed to determine surfactant effects on residual water and oil saturations in porous media. In particular, these tests focused on the impact of submicellar surfactant solutions and the potential application of these low concentration systems to light nonaqueous phase liquid (LNAPL) contamination in the vadose zone. One set of tests involved surfactant flushing in soil-filled columns followed by drainage to residual water saturation and LNAPL injection to determine the subsequent residual LNAPL saturation. Another set of tests involved surfactant application to a soil-filled column already holding residual LNAPL saturation to promote the release of the previously trapped LNAPL. Test results showed surfactant systems could reduce both residual water and oil saturations by up to 50%. In addition, submicellar surfactant systems were equally effective as supramicellar solutions in reducing residual water saturations and potentially more effective at reducing residual oil saturations. Submicellar surfactant applications to a medium-grained (0.85–0.425 mm) soil containing residual LNAPL saturations were effective at releasing up to 50% of the previously trapped residual LNAPL. These applications were less successful in a fine-grained soil as full drainage of water and LNAPL was unachievable due to high capillary pressures. Overall, observations suggest low concentration surfactant solutions may have the ability to release significant amounts of previously trapped LNAPL in the vadose zone, potentially increasing free-product recovery rates and lowering LNAPL saturations to levels more favorable for biodegradation. The decrease in overall saturations (both water and oil) in a contaminated vadose zone could also present an increase in air permeability, thus enhancing other vadose zone treatment technologies such as bioventing or soil vapor extraction.
Urinary retention after operations for benign anorectal diseases

PURPOSE: This study was undertaken to determine the incidence and risk factors for urinary retention after operations for benign anorectal diseases. METHODS: We reviewed 1,026 consecutive operations for benign anorectal diseases from 1989 to 1994. Risk factor analysis was done for patients undergoing hemorrhoidectomy (Group I) and other procedures (Group II) using logistic regression analysis. RESULTS: The number of procedures and urinary retention rate was as follows: 344 (34 percent) hemorrhoidectomies, 159 (2 percent) fistulotomies, 95 (5 percent) incision/drainage, 247 (4 percent) lateral internal sphincterotomy, 181 (17 percent) combinations of the above four procedures, and overall 1,026 (16 percent). In Group I, four-quadrant excision (odds ratio, 3.3;P=0.0004), three quadrant excision (odds ratio, 2.4;P=0.003), morphine equivalents >33 (odds ratio, 1.8;P=0.01), and male gender (odds ratio, 1.7;P=0.02) were independent risk factors. In Group II, more than one operation (odds ratio, 3.0;P=0.004), older age (odds ratio, 3.1;P=0.005), intraoperative fluids (odds ratio, 2.6;P=0.03), and postoperative fluids (odds ratio, 2.7;P=0.02) were independent risk factors. Urinary obstructive symptoms for both groups and perioperative fluids for Group I were NOT independent risk factors. Hospital stay was prolonged significantly in patients with urinary retention (P=0.0001). CONCLUSIONS: Urinary retention is a common postoperative complication that increases hospital stay. It is most common after hemorrhoidectomy. Disease severity (quadrants excised and analgesia requirement for Group I and number of operations for Group II) is an important risk factor for both groups studied. Older age in Group I and perioperative fluid in Group II may be important risk factors.
Combining morphometric evidence from multiple registration methods using dempster-shafer theory

In tensor-based morphometry (TBM) group-wise differences in brain structure are measured using high degreeof- freedom registration and some form of statistical test. However, it is known that TBM results are sensitive to both the registration method and statistical test used. Given the lack of an objective model of group variation is it difficult to determine a best registration method for TBM. The use of statistical tests is also problematic given the corrections required for multiple testing and the notorius difficulty selecting and intepreting signigance values. This paper presents an approach to address both of these issues by combining multiple registration methods using Dempster-Shafer Evidence theory to produce belief maps of categorical changes between groups. This approach is applied to the comparison brain morphometry in aging, a typical application of TBM, using the determinant of the Jacobian as a measure of volume change. We show that the Dempster-Shafer combination produces a unique and easy to interpret belief map of regional changes between and within groups without the complications associated with hypothesis testing.
008 Molecular tools

Abstract not available. Source of funding: None declared. Conflict of interest: None declared. mtoner@hms.harvard.edu
Development of an In Vitro Compartmentalization Screen for High-Throughput Directed Evolution of [FeFe] Hydrogenases

Background [FeFe] hydrogenase enzymes catalyze the formation and dissociation of molecular hydrogen with the help of a complex prosthetic group composed of common elements. The development of energy conversion technologies based on these renewable catalysts has been hindered by their extreme oxygen sensitivity. Attempts to improve the enzymes by directed evolution have failed for want of a screening platform capable of throughputs high enough to adequately sample heavily mutated DNA libraries. In vitro compartmentalization (IVC) is a powerful method capable of screening for multiple-turnover enzymatic activity at very high throughputs. Recent advances have allowed [FeFe] hydrogenases to be expressed and activated in the cell-free protein synthesis reactions on which IVC is based; however, IVC is a demanding technique with which many enzymes have proven incompatible. Methodology/Principal Findings Here we describe an extremely high-throughput IVC screen for oxygen-tolerant [FeFe] hydrogenases. We demonstrate that the [FeFe] hydrogenase CpI can be expressed and activated within emulsion droplets, and identify a fluorogenic substrate that links activity after oxygen exposure to the generation of a fluorescent signal. We present a screening protocol in which attachment of mutant genes and the proteins they encode to the surfaces of microbeads is followed by three separate emulsion steps for amplification, expression, and evaluation of hydrogenase mutants. We show that beads displaying active hydrogenase can be isolated by fluorescence-activated cell-sorting, and we use the method to enrich such beads from a mock library. Conclusions/Significance [FeFe] hydrogenases are the most complex enzymes to be produced by cell-free protein synthesis, and the most challenging targets to which IVC has yet been applied. The technique described here is an enabling step towards the development of biocatalysts for a biological hydrogen economy.
Issues in Evaluating Importance Weighting in Quality of Life Measures

For most empirical research investigating the topic of importance weighting in quality of life (QoL) measures, the prevailing approach has been to use (1) a limited choice of global QoL measures as criterion variables (often a single one) to determine the performance of importance weighting, (2) a limited option of weighting methods to develop importance weighting, and (3) a limited number of domains to construct the (formative-indicator) measures. Although limitations resulted from a limited choice of global QoL measures as criterion variables to determine the performance of importance weighting and a limited option of weighting methods to develop importance weighting have been recognized previously, little attention has been paid to the impact of non-comprehensive domains in QoL measures constructed based on the formative-indicator approach. Using empirical data, this article revealed the potential impacts of non-comprehensive domains on the evaluation of importance weighting in QoL measures. Results presented in this article showed that both of the two most popular methods of evaluating the performance of importance weighting in QoL measures, correlation and moderated regression analysis, could produce misleading results in the situation when QoL measures constructed using the formative-indicator approach did not include comprehensive domains. Issues discussed in this article are of great importance to research in the field of QoL, especially on the topic of importance weighting in QoL measures.
Molecular genetic mapping of dwarfing genes in oat

Restriction fragment length polymorphism (RFLP) analysis provides a valuable tool for characterizing and understanding relationships among genes for useful traits in crop species, particularly in ones with complex genomes such as the hexaploid cultivated oat Avena sativa L. (2n=6x=42). Using Bulked Segregant Analysis (BSA) and F2 RFLP linkage data, we mapped three dominant oat dwarfing loci to different regions of the oat genome. Dw6, in oat line OT207, is 3.3±1.3 cM from the Xumn145B locus, which has not been placed on the hexaploid oat linkage map. Dw7, in line NC2469-3, is 4.3±2.3 cM from Xcdo1437B and 33±4.1 cM from Xcdo708B. This places Dw7 to linkage group 22. Dw8, in the Japanese lines AV17/3/10 and AV18/2/4, mapped 4.9±2.2 cM from Xcdo1319A in an AV17/3/10×‘Kanota’ F2 population and 6.6±2.6 cM from it in an AV18/2/4×‘Kanota’ population. This places Dw8 to linkage group 3. Aneuploid analysis of markers linked to the dwarfing genes located Dw6 on the smallest oat chromosome (chromosome 18) and Dw7 on the longest satellited chromosome (chromosome 19). The RFLP markers closely linked to the three dwarfing genes identify distinct regions of the oat genome that contribute to plant height and they should be useful in characterizing new genetic sources of dwarfness in oat.
Rational choice and the framing of decisions

Alternative descriptions of a decision problem often give rise to different preferences, contrary to the principle of invariance that underlines the rational theory of choice. Violations of this theory are traced to the rules that govern the framing of decision and to the psychological principles of evaluation embodied in prospect theory. Invariance and dominance are obeyed when their application is transparent and often violated in other situations. Because these rules are normatively essential but descriptively invalid, no theory of choice can be both normatively adequate and descriptively accurate.
Taking Relationship Seriously in Psychotherapy: Radical Relationality

Psychologists who have historically focused on relationships have tended to underestimate the radical nature of human relationship. A “serious” or an ontological relationality would change the nature of psychotherapy. We describe this change in a discussion of two approaches to relationship, weak and strong relationality. We argue that weak relationality, the general conception of relationship in mainstream psychology, does not ultimately take even the therapeutic relationship seriously. We then discuss and illustrate ten practical implications that a strong relationality would have for psychotherapy.
Toward a Relevant Agenda for a Responsive Public Administration

The relevance of the concept “bureaucratic responsiveness” has been questioned in recent years. One reason for the questioned relevance is the apparent environmental changes that are occurring in public administration. Globalization and devolution have infiltrated the halls of bureaucracies. Public agencies are being asked to collaborate with actors in other sectors of society, including, and especially, citizens and citizen associations. In addition to these environmental changes, administrators are being confronted with potentially competing ethical obligations that make decisions regarding responsiveness challenging. This article uses these evolving environments and competing ethical obligations to formulate a set of six variants of bureaucratic responsiveness: dictated, constrained, purposive, entrepreneurial, collaborative, and negotiated. It is argued that to be relevant, writers and researchers in public administration need to consider each of these variants and how they potentially collide with each other to shape administrator thought and behavior, particularly in the collaborative context. In conclusion, it is suggested that calls for the abandonment of “responsiveness” as a central concept in public administration are premature, and emerging research questions are offered.
A Large Area Imaging Gas Scintillation Proportional Counter For Use In X-Ray Astronomy

A large area (200 sq cm), broad bandwidth (0.1-70 keV), imaging gas scintillation proportional counter (IGSPC) has been constructed for use in X-ray astronomy. The IGSPC consists of a high pressure xenon gas scintillation proportional counter (GSPC) coupled to a multi-wire proportional counter (MWPC) via a calcium fluoride window. THe MWPC, filled with a mixture of argon, methane, and tetrakis (dimethylamino) ethylene, detects the UV photons emitted by the xenon gas in the GSPC. The detector has a measured energy resolution of 8.0 percent (FWHM) and 4.3 percent (FWHM) at 5.9 keV and 22.1 keV, respectively. The predicted spatial resolution of the detector is less than 1 mm (FWHM) between 3-22 keV and 37-60 keV. A method to determine the three-dimensional location of detected X-rays is described. In addition, a combination of discrimination schemes designed to reduce the non-X-ray background in the IGSPC by more than two orders of magnitude is discussed.
Feedback, Subjective Time Estimates, and User Satisfaction

This experiment investigates the effects of three types of feedback, static, dynamic and cumulative progress, designed to keep the user apprised while a computer completes a transaction. Using a simulated online movie store, participants chose movies for various audiences and then were required to wait 15 or 30 seconds for the computer to process their order. Participants perceived the transactions using the dynamic feedback indicators and cumulative progress bars to be more reasonable than transactions using the static feedback display, even though the transaction times were identical. However, there was no difference in the perception of processing time reasonableness between the dynamic display and the cumulative progress indicator. Despite this, cumulative progress bars were preferred to both dynamic and static feedback indicators.