cssi/SciSciGPT-SciSciNet huggingface dataset:
Fetal Outcomes Associated with the Sequence of Doppler Deterioration in Severely Growth-Restricted Fetuses.

Objectives Various patterns of Doppler deterioration exist in fetal growth restriction (FGR). However, the factors that differentiate these patterns are still unknown. The purpose of this study was to clarify the perinatal outcomes and factors to determine the pattern of Doppler deterioration in severe FGR. Materials and methods We conducted a retrospective cohort study of preterm severe FGR with Doppler abnormality, wherein the clinical features, including maternal characteristics, medical history, and sonographic findings, were compared between the patterns of Doppler deterioration. We used the multivariable logistic regression analyses to identify the factors associated with the pattern of Doppler deterioration. Results Of 322 eligible fetuses, 143 had Doppler abnormalities. Fetuses with Doppler deterioration from ductus venosus uniquely featured fetal and placental-umbilical abnormalities detected after birth. Gestational age (GA) at diagnosis of FGR and at the first diagnosis of Doppler abnormality in fetuses with Doppler deterioration from middle cerebral artery (MCA) were later than those from umbilical artery. In addition, the factor associated with Doppler deterioration from MCA was 31-week GA at the first diagnosis of Doppler abnormality (adjusted odds ratio [aOR]: 26.7; 95% CI: 8.35-103), not GA at diagnosis of FGR (aOR: 1.82; 95% CI: 0.50-5.96). Conclusions Characteristics of each Doppler deterioration pattern might reflect FGR etiology. Undetectable anomalies and umbilical-placental abnormalities were found in fetuses with Doppler deterioration from the ductus venosus. Doppler deterioration from the MCA was observed after 31 weeks of gestation not only in the late-onset FGR but also in the early-onset FGR with normal umbilical artery Doppler findings.
Testimony before the House Financial Services Committee; Hearing on 'Examining Corporate Priorities: The Impact of Stock Buybacks on Workers, Communities, and Investors'

In this testimony I discuss the causes and consequences of the rise of stock buybacks. Stock buybacks may sound like a technical matter of corporate finance: Why should it matter whether or not corporations repurchase their own stock? When a company executes a stock buyback, they raise the price of that company’s shares for a period of time, but the funds spent on buybacks are then unavailable to be spent on the types of corporate activities that could make the company more productive over the long term: investments in future productivity and in the workforce. Stock buybacks are one of the drivers of our imbalanced economy, in which corporate profits and shareholder payments continue to grow while wages for typical workers stay flat. Stock buybacks are virtually unregulated, even though Congress has recognized their potential for market manipulation. Importantly, there are currently no meaningful limits to stop executives from using corporate money on stock buybacks to raise share prices for their own short-term gain. Executives are not required to disclose that they have conducted a buyback until the next quarter’s filing; meanwhile, there are no substantive limits to stop them from selling their own personal shares in the same quarter as they are conducting buybacks.
The Functional Operation of Workers’ Compensation COVID Presumptions

During 2020, a number of U.S. states implemented workers' compensation COVID-19 presumptions. This short informal paper defines and explains legal presumptions generally and then discusses the workers' compensation presumptions. The paper contends that at this juncture it is not clear whether states intended to enact "Thayer-Wigmore" or "Morgan" presumptions; but if they operate as Thayer-Wigmore presumptions they will not do workers' compensation claimants much good in the context of non-jury proceedings presided over by administrative law judges..
From colonial subjects to post-colonial citizens? Considerations for a contemporary study of Black México

The Mexican government is currently attempting to incorporate Black Mexicans into the national cultural landscape. However, the centring of whiteness through mestizaje limits the possibilities of B...
Experimental and computational kinetics study of the liquid-phase hydrogenation of CC and CO bonds

Abstract Solvent effects on adsorption equilibrium and reaction kinetics are evaluated for hydrogenation reactions catalyzed by Pd/alumina in a series of different solvents. Three reactants – cyclohexene, benzene and benzaldehyde – and three solvents – n-heptane (HEP), methylcyclohexane (MCHA), decalin (DL) – have been investigated. Kinetic analysis of hydrogenation of cyclohexene reveals that hydrogen adsorbs on different sites from those where cyclohexene and the solvents adsorb; however, the presence of hydrogen on these separate sites affects the heats of adsorption of the hydrocarbons. When the solvent is a weakly interacting linear alkane (HEP), the rate determining step of the reaction is the first hydrogenation of adsorbed cyclohexene. This conclusion is supported by DFT calculations that show a higher enthalpy barrier for the first hydrogenation than for the second, while statistical thermodynamics analysis validates the physical significance of the entropy of adsorption parameters derived from the kinetic fitting of experimental data. By contrast, with solvents such as MCHA and DL, which interact more strongly with the metal surface and compete for active sites with the reactant and the surface intermediate, the rate limiting step seems to shift to the second hydrogenation step. One of the main conclusions of the study is that the effects observed with non-polar solvents are mostly due to competitive adsorption of the solvent, which causes a decrease in surface coverage of reactants and surface intermediates. Indeed, under identical conditions, the hydrogenation rates of C C bonds in cyclohexene (or the aromatic ring in benzene) follow the order HEP > MCHA > DL, which is consistent with the strongest solvent/metal interaction for DL and the weakest for HEP. Further, binary solvent mixtures of DL-HEP exhibit non-idealities that are clearly evident in the fitting of hydrogenation rates. It is proposed that the higher activity coefficient of liquid DL in the liquid mixture enhances its surface coverage, competing more effectively with the reactant, which causes a decrease in catalytic activity larger than that predicted assuming an ideal mixture of solvents. Likewise, large drops in benzene hydrogenation rates are observed in water-organic co-solvent mixtures due to the competitive adsorption of water on the Pd surface. Water adsorption is further enhanced by the non-ideality of the water-organic mixture. By contrast, in the hydrogenation of the C O bond of benzaldehyde, the presence of water provides a favorable alternative reaction path with lower activation barrier, resulting in higher hydrogenation activity when the reactant is a carbonyl-containing molecule, such as benzaldehyde. In this system, the H-bonded water network assists shuttling a proton from the Pd surface to the hydrophilic O atom in C O, assisted by surface charge separation. Since this H transfer pathway cannot take place with C C bonds or aromatic rings, only site inhibition occurs for these reactions.
Performance of Cellular Concrete under Low-Velocity Impact and Penetration

Cellular concrete, also known as foamed concrete, has been widely used in different geotechnical and nonstructural applications owing to a unique geometric nature that results in low density and high flowability and its low construction cost. The behavior of cellular concrete under impact or penetration has also drawn attention in applications such as engineered material arrestor systems, emergency escape ramps, and crash barriers. The high void content inside cellular concrete allows it to undertake large deformation, which could lead to high energy absorption. However, there is still a lack of fundamental understanding of the energy absorption of the material and response of the material under impact or penetration. This paper carries out an investigation of the response of cellular concrete subjected to low-velocity impact and penetration. Cellular concretes with different foaming agents and with fibers were prepared and evaluated. Experimental results demonstrated the superior ability of cellular concrete in absorbing and dissipating impact and penetration energies compared with conventional concrete. The paper shows that through steadily deforming the internal void structure, cellular concrete can diminish the reaction force caused by a collision and dissipate penetration energy. Results of the study can help to better understand the mechanism of energy absorption of cellular concrete so as to better tailor it for different applications.
Shifting loads as a result of chair articulations and associated perfusion responses in the context of pressure injuries: An investigation with able-bodied individuals

Abstract Wheelchair users with spinal cord injuries experience pressure injuries at high rates, causing a decrease in quality of life and an increased financial burden. The soft tissue in the buttocks (beneath the ischial tuberosities) and lower back (behind the sacrum) experience large interface pressures over long periods while seated, putting them at high risk of pressure injury development. The goals of this research were to evaluate the ability of an articulating chair design to redistribute pressures on the body and to affect blood perfusion in the buttocks tissue over the ischial tuberosities. Using a unique, custom-designed chair developed for this research, pressure and blood perfusion were obtained for numerous seated positions that included recline, seat pan tilt, and back articulations. Reclining the chair back increased maximum pressures in the buttocks and lower back regions, while it decreased maximum pressures in the upper back and thigh regions. Increasing seat pan tilt, or rotating the anterior edge of the seat pan above the posterior edge, decreased maximum pressures in the buttocks and lower back regions and increased perfusion in the buttocks. Results suggested that using back recline and seat pan tilt together to create a whole-body tilt increased pressures in the back and decreased pressures in the buttocks. Changes in back articulation redistributed pressure in all back regions. Thus, the articulating chair design redistributed pressures in all areas of the body and promoted blood perfusion in the buttocks while seated. Pressure redistribution and perfusion promotion are fundamental to reducing pressure injury risk.
Submicron Microscopy and Microprobes

Having built a device consisting of elements made to submicron tolerances, it is often necessary to examine it to see whether the device was built as specified and whether the components are of the required materials with the desired physical properties.
Nanoscale reduction of graphene oxide under ambient conditions

Abstract Localized voltage-induced reduction, initiated by a conductive atomic force microscope probe under ambient conditions, is used to pattern electrically conductive reduced graphene oxide (rGO) regions in electrically insulating graphene oxide (GO). This method is shown to reduce single and multiple layer GO on ultra-flat Au substrates with feature sizes as small as 4.0 nm, with the reduction resolution depending strongly on humidity and number of GO layers. In situ current levels during reduction are used to track reaction kinetics, which follow a rate-limited process where the generation and transport of hydrogen ions are the primary rate limiting steps. Tip-enhanced Raman spectroscopy is used to map the nanoscale structure and local disorder in voltage-reduced GO and rGO single sheets. It is found that reduction of GO causes a decrease in tip-enhanced Raman scattering intensity in both the D-band and G-band, but the D/G intensity ratio remains unchanged following reduction, indicating that defects are not introduced by the reduction process.
The use of bootstrap in computer-intensive Bayesian methods

The use of computer-intensive methods in signal processing becomes more frequent as the power of computers continues to increase. Two classes of such methods are Bayesian Monte Carlo sampling and the bootstrap. In general, these types of methods are used in different settings. The Bayesian methods are usually applied in situations where parametric assumptions are made about the densities that generate the observed data, and the bootstrap, in cases where such assumptions are absent. We explore the possibility of combining these methods. The role of the bootstrap is to provide samples for constructing density functions needed for drawing samples which would allow for more accurate integration or optimization carried out by the Bayesian methods.
Group actions and the topology of nonnegatively curved $4$-manifolds

We consider nonnegatively curved $4$-manifolds that admit effective isometric actions by finite groups and from that draw topological conclusions about the manifold. Our first theorem shows that if the manifolds admits an isometric $Z_{p} \times Z_{p}$, for $p$ large enough that the manifold has Euler characteristic less than or equal to five. Our second theorem requires no hypothesis on the structure of the group other then that it be large but it does require the manifold to be $\delta$-pinched, in which case we can then again conclude that the Euler characteristic is less than or equal to five.
Spectral Energy Distribution Fitting: Application to Lyman Alpha-Emitting Galaxies

Spectral Energy Distribution (SED) fitting is a well-developed astrophysical tool that has recently been applied to high-redshift Lyman Alpha-emitting galaxies. If rest-frame ultraviolet through near-infrared photometry is available, it allows the simultaneous determination of the star formation history and dust extinction of a galaxy. Lyman Alpha-emitter SED fitting results from the literature find star formation rates ~3 M_sun/yr, stellar masses ~10^9 M_sun for the general population but ~10^10 M_sun for the subset detected by IRAC, and very low dust extinction, A_V < 0.3, although a couple of outlying analyses prefer significantly more dust and higher intrinsic star formation rates. A checklist of 14 critical choices that must be made when performing SED fitting is discussed.
What Drives Waves in Information Systems: The Organizing Vision Perspective

Waves of fashionable ideas shape the practice and research of information systems (IS). What forces drive idea waves in IS? This research takes the first step to empirically study IS idea waves in inter-organizational communities through the lens of organizing visions. Introduced by Swanson and Ramiller (1997), an organizing vision is a focal community idea for applying information technologies in organizations. Each organizing vision is produced and sustained through a discourse whose popularity often runs a wave-like lifecycle. By studying the discourse promoting enterprise resource planning (ERP), I examine the influence of four forces on the upswing phase of an organizing vision discourse wave: (1) a business problematic highlighted by discourse, (2) the early market for an IS innovation, (3) core technologies, and (4) the collapse of old organizing visions in a problem domain. A better understanding of the relationship between key forces and organizing vision development will help both practitioners and researchers monitor and relate to the exciting waves in our field.
Production and nutrient dynamics of a Syringodium filiforme Kütz. Seagrass bed in Indian River Lagoon, Florida

A year-long analysis of the characteristics of the seagrassSyringodium filiforme and the associated dynamics of the nutrient pool in the sediment pore water was done to assess co-variation. Changes in seagrass growth rate and standing stock throughout the year were accompanied by seasonal changes in the nutrient pools. The link between plant production and morphometrics and the sediment nutrient pool was found to be predominantly physiological, with the plant balancing the ability to photosynthesize with the nutrients needed for maintaining production. Measurements of whole plant growth for this seagrass, rather than the more typical leaf growth measurements, show that the production of new shoots and rhizome elongation for these plants represents as substantial amount of growth that usually goes unmeasured. Further, these whole plant growth measures demonstrate the rapid lateral rhizome spread of this species, exceeding one meter per plant per year. The primary cause of seasonal variation in the yearly seagrass cycle was investigated. Correlation analysis supported the hypothesis that the major factor controlling seasonal variation in this seagrass was light. During the peak growing season, however, growth was not regulated by light but by nitrogen. Depletion of the sediment ammonium pool and reduction in pore water ammonium relative to adsorbed ammonium, as well as changes in N content of seagrass leaves, support our hypothesis of peak growing season nitrogen limitation. Our results forSyringodium filiforme in terrigenous sediments are in contrast to our recent findings of phosphorus limitation in this same species occurring in carbonate sediments.
Negative running can prevent eternal inflation

Current data from the Planck satellite and the BICEP2 telescope favor, at around the 2 σ level, negative running of the spectral index of curvature perturbations from inflation. We show that for negative running α < 0, the curvature perturbation amplitude has a maximum on scales larger than our current horizon size. A condition for the absence of eternal inflation is that the curvature perturbation amplitude always remain below unity on superhorizon scales. For current bounds on nS from Planck, this corresponds to an upper bound of the running α < −9 × 10−5, so that even tiny running of the scalar spectral index is sufficient to prevent eternal inflation from occurring, as long as the running remains negative on scales outside the horizon. In single-field inflation models, negative running is associated with a finite duration of inflation: we show that eternal inflation may not occur even in cases where inflation lasts as long as 104 e-folds.
Protein binding microarrays for the characterization of DNA-protein interactions.

A number of important cellular processes, such as transcriptional regulation, recombination, replication, repair, and DNA modification, are performed by DNA binding proteins. Of particular interest are transcription factors (TFs) which, through their sequence-specific interactions with DNA binding sites, modulate gene expression in a manner required for normal cellular growth and differentiation, and also for response to environmental stimuli. Despite their importance, the DNA binding specificities of most DNA binding proteins still remain unknown, since prior technologies aimed at identifying DNA–protein interactions have been laborious, not highly scalable, or have required limiting biological reagents. Recently a new DNA microarray-based technology, termed protein binding microarrays (PBMs), has been developed that allows rapid, high-throughput characterization of the in vitro DNA binding site sequence specificities of TFs, other DNA binding proteins, or synthetic compounds. DNA binding site data from PBMs combined with gene annotation data, comparative sequence analysis, and gene expression profiling, can be used to predict what genes are regulated by a given TF, what the functions are of a given TF and its predicted target genes, and how that TF may fit into the cell's transcriptional regulatory network.
La cosmovisión romántica: siete síntomas y cinco metáforas

La vivencia psicologica del romanticismo tanto para los escritores romanticos como para sus lectores estriba en el efecto unido de siete sintomas y cinco metaforas de hondo sentido humano. Los siete sintomas son: el predominio del sentimiento sobre el pensamiento; la fusion del alma del poeta con la de la naturaleza; la seudo-divinidad del romantico; la sensacion de la soledad; la actitud de superioridad; el fastidio universal; y el goce en el dolor. Las cinco metaforas son: la perdida de la juventud; el satanismo del alma inocente; el amor; la lagrima solitaria y la contemplacion del suicidio. Abundan los ejemplos en textos literarios espanoles producidos entre 1770 y 1870, con lo cual se refuta la nocion de que el romanticismo espanol sea tardio y de poca duracion.
Informed consent to e-therapy

E-therapy, the provision of mental health treatment through the Internet, poses many risks as well as benefits. This article addresses some relevant risks and benefits of e-therapy and discusses the practicality of using computers in the informed consent process. Although e-therapy has numerous proponents, no clinical trials have assessed its long-term effectiveness. To limit liability and to protect patients, e-therapy providers should disclose material risks as well as possible benefits and engage patients in an active dialogue. A thorough informed consent procedure enables patients to make an educated decision about whether e-therapy is right for them. In the future, e-therapy and informed consent online may become more common; in the mean time, clinicians must be prepared for e-therapy's uncertain legal status and allow patients to decide for themselves whether or not to seek counseling on the Internet.
The phenylalanine ammonia lyase (PAL) gene family shows a gymnosperm-specific lineage

Background Phenylalanine ammonia lyase (PAL) is a key enzyme of the phenylpropanoid pathway that catalyzes the deamination of phenylalanine to trans-cinnamic acid, a precursor for the lignin and flavonoid biosynthetic pathways. To date, PAL genes have been less extensively studied in gymnosperms than in angiosperms. Our interest in PAL genes stems from their potential role in the defense responses of Pinus taeda, especially with respect to lignification and production of low molecular weight phenolic compounds under various biotic and abiotic stimuli. In contrast to all angiosperms for which reference genome sequences are available, P. taeda has previously been characterized as having only a single PAL gene. Our objective was to re-evaluate this finding, assess the evolutionary history of PAL genes across major angiosperm and gymnosperm lineages, and characterize PAL gene expression patterns in Pinus taeda.
The Hand Injury Severity Scoring System and Workers’ Compensation Cases in Wisconsin, USA

The Hand Injury Severity Score was retrospectively applied to a group of workers’ compensation cases in Wisconsin, USA. A statistically significant correlation was found between the score and the time interval between injury and the end of healing. These results are comparable to the findings in the original study of Campbell and Kay (1996). We provide some suggestions for further development of this scoring system.
A Novel Fusion Power Concept Based on Molten-Salt Technology: PACER Revisited

This paper discusses modifications to an old concept for using peaceful nuclear explosions to achieve practical fusion power. With this concept, useful energy and materials are obtained by repetitively setting off nuclear explosions in an underground cavity. This proposal, which is based on molten-salt technology, involves two modifications: line the cavity with steel to make it engineerable and predictable rather than relying on an unsupported earthen cavity such as a cavity excavated in a salt dome; and use molten salt rather than steam. More than 70% of the energy released is then absorbed by liquid-salt evaporation, and the pressure to be contained for a given yield can be reduced by a factor of 3 or more. These modifications result in several improvements in the safety and feasibility of the contained fusion concept which includes: the tritium produced, being insoluble in the molten salt, can easily be pumped away and purified when all the vaporized salt condenses, rather than being mixed with steam; the tritium inventory is substantially reduced, effectively reducing the large hazard in case of accidental venting to the atmosphere; and reducing the yield used in the older studied could reduce the cost of the cavity considerably.
Gender difference in interactions between MAOA promoter uVNTR polymorphism and negative familial stressors on body mass index among Chinese adolescents.

What is already known about this subject Initial evidence from recent studies indicated a relationship between the high-activity MAOA uVNTR polymorphism and lower risk of obesity even though findings were varied across populations, and hence replication studies with population-based samples are clearly warranted. What this study adds Our findings confirmed the genetic effects of MAOA uVNTR polymorphism on body mass index in a Chinese adolescent population. This study demonstrated a significant gene–environment interaction with negative familial stressors in girls only, which provides a new insight on the causes of obesity, and thus, potential avenues of prevention. Summary Objectives Monoamine oxidase A (MAOA) modulates metabolism of serotonin and dopamine metabolism, neurotransmitters involved in regulation of appetite and food intake. The gene coding for MAOA contains a 30-bp tandem repeat (uVNTR) polymorphism in its promoter region that has been previously identified to be associated with obesity with mixed findings in the literature. Our goals were to replicate the population effects of this functional polymorphism on obesity risk, and to further explore gender differences and interaction effects with negative stressors. Methods Analyses were conducted with data on genotypes, measured weight and height, and self-reported behavioural characteristics among 1101 Chinese adolescents 11–15 years old living in Wuhan, China. Results Girls with the high-activity allele had significantly lower body mass index (BMI; β = −0.25 ± 0.98, P = 0.011) compared to those with the low activity allele. Experience of negative familial stressors (e.g., death or illness of family members, hit or scolded by parents and increased quarrelling with parents, parents argued frequently) significantly weakened this protective genetic effect on BMI (P for interaction = 0.043). Stratified analyses showed a significant protective genetic effect on BMI only within the stratum of low stress level (β = −0.44 ± 0.14, P = 0.002). No similar effect was observed among boys. Conclusions Our findings confirm the genetic effects of MAOA uVNTR polymorphism on BMI in a Chinese adolescent population and suggest potential genetic interactions with negative familial stressors.
Hyaluronic acid-based clinical biomaterials derived for cell and molecule delivery in regenerative medicine.

The development of injectable and biocompatible vehicles for delivery, retention, growth, and differentiation of stem cells is of paramount importance for regenerative medicine. For cell therapy and the development of clinical combination products, we created a hyaluronan (HA)-based synthetic extracellular matrix (sECM) that provides highly reproducible, manufacturable, approvable, and affordable biomaterials. The composition of the sECM can be customized for use with progenitor and mature cell populations obtained from skin, fat, liver, heart, muscle, bone, cartilage, nerves, and other tissues. This overview describes the design criteria for “living” HA derivatives, and the many uses of this in situ crosslinkable HA-based sECM hydrogel for three-dimensional (3-D) culture of cells in vitro and translational use in vivo. Recent advances allow rapid expansion and recovery of cells in 3-D, and the bioprinting of engineered tissue constructs. The uses of HA-derived sECMs for cell and molecule delivery in vivo will be reviewed, including applications in cancer biology and tumor imaging.
Development of LBP110 expression by neural crest-derived enteric precursors: migration and differentiation potential in ls/ls mutant mice.

Neural crest-derived cells acquire a 110-kD laminin-binding protein (LBP110) when they colonize the murine bowel. Laminin stimulates LBP110-expressing cells to develop as neurons. We have followed the development of LBP110 by neural crest-derived cells as they enter the gut of control and ls/ls mutant mice. The expression of neurofilament and choline acetyltransferase was used as markers of a neuronal phenotype. Tyrosine hydroxylase was used as a marker for the mash-1-dependent lineage of enteric precursors, while calcitonin gene-related peptide was used as a marker for the mash-1-independent lineage of crest-derived cells. A subset of cells expressing LBP110 was located along the vagi at E10 at cervical and thoracic levels. At E12, cells expressing LBP110 extended from the foregut to the midgut. The expression of neurofilament protein lagged behind that of LBP110 by about 0.5 day and then became coincident with LBP110 immunoreactivity. By E15, cells doubly labeled with antibodies to LBP110 and neurofilament protein were located along the entire extent of the bowel up to but not including the terminal colon. By E16, both the proximal and terminal colon contained cells expressing LBP110 and neurofilaments. The pattern of immunoreactivity could not be distinguished between ls/ls and control animals prior to E16. By E16, when the terminal colon of control animals contained many cells expressing LBP110 and neurofilaments, the terminal colon of ls/ls animals lacked cells expressing these proteins; nevertheless, structures outside of the terminal colon were heavily endowed with cells expressing LBP110 and neurofilaments. These ectopically located cells derived from both mash-1-dependent and -independent lineages of crest-derived precursors. © 1998 John Wiley & Sons, Inc. J Neurobiol 35: 341–354, 1998
Pharmacists' Perceptions of Barriers to Implementing Medication Therapy Management and the Role of Pharmacy Technicians in Overcoming the Barriers

Background:Recent literature supports the value of clinical pharmacy services in the outpatient setting, but pharmacists must overcome barriers to the implementation of clinical services to establish an effective and efficient program.Objective:To identify pharmacists' perceptions of barriers to the implementation of medication therapy management (MTM) and perceptions of collaboration with pharmacy technicians.Methods:Surveys were sent to all 415 community pharmacists in a supermarket pharmacy chain marketing area in Ohio. Pharmacists completed the anonymous survey to indicate their opinions regarding a series of potential barriers to the implementation of MTM, including education and training, current and desired roles of pharmacy technicians, and support from store management.Results:Of responding pharmacists, 16.2% reported that they had personally participated in an MTM encounter, with an average number of encounters per pharmacist of 1.4. Pharmacists reported a desire for additional training in disea...
STRUCTURE OF BACTERIORHODOPSIN and in situ ISOMERIZATION OF RETINAL: A MOLECULAR DYNAMICS STUDY*

– Henderson's model of the structure of bacteriorhodopsin has been completed by adding the missing loop regions and by subsequent energy minimization and equilibration (for about 100 ps) at 300 K. Analysis of the structure during a later 20 ps molecular dynamics run showed no significant deviations from the Henderson model. In situ isomerization reactions of the retinal chromophore in bacteriorhodopsin have then been simulated to investigate the chromophore protein interaction for the three isomerization reactions: (i) all-trans 13-cis; (ii)all-trans 13,14-dicis; and (iii) all-trans 13,15-dicis. We find that reaction (iii) which accompanies dark-adaptation of bacteriorhodopsin can proceed in the binding site without any sterical hinderance and involves negligible motions of the covalently bound Lys-216 and other side groups. Reaction (ii) exhibits a somewhat larger but still small energy barrier and involves little rearrangement of Lys-216 and the protein backbone. Reaction (i) experiences a sterical impediment amounting to more than 10 kT at physiological temperatures and also induces significant structural changes at the binding site. Our simulations also reveal that reaction (ii) as a photo-isomerization process can be completed within about 400 fs, whereas reaction (i) requires longer times for completion. Reaction (i) is also accompanied by a co-rotation of the 14–15 bond by 150° (even when a torsional barrier of 20 kcal/mol is imposed to impede rotation of the 14–15 bond) such that photoreactions (i) and (ii), in effect, lead to very similar final geometries. Isomerization (ii) can readily explain the pump mechanism of bacteriorhodopsin: the sequential, thermal back-reaction 13,14-dicis 13-cisall-trans can be acid-base catalyzed, i.e., coupled to deprotonation and reprotonation of retinal's Schiff base nitrogen. The orientation of retinal is such that Asp-85 can act as the acceptor and Asp-96 as the (indirect) donor. The thermal back-reaction 13,14-dicis all-trans can be coupled to vectorial Cl− ion transport as well.
A ventrally localized protease in the Drosophila egg controls embryo dorsoventral polarity.

Drosophila embryo dorsoventral (DV) polarity is defined by serine protease activity in the perivitelline space (PVS) between the embryonic membrane and the inner layer of the eggshell. Gastrulation Defective (GD) cleaves and activates Snake (Snk). Activated Snk cleaves and activates Easter (Ea), exclusively on the ventral side of the embryo. Activated Ea then processes Spatzle (Spz) into the activating ligand for Toll, a transmembrane receptor that is distributed throughout the embryonic plasma membrane. Ventral activation of Toll depends upon the activity of the Pipe sulfotransferase in the ventral region of the follicular epithelium that surrounds the developing oocyte. Pipe transfers sulfate residues to several protein components of the inner vitelline membrane layer of the eggshell. Here we show that GD protein becomes localized in the ventral PVS in a Pipe-dependent process. Moreover, ventrally concentrated GD acts to promote the cleavage of Ea by Snk through an extracatalytic mechanism that is distinct from GD's proteolytic activation of Snk. Together, these observations illuminate the mechanism through which spatially restricted sulfotransferase activity in the developing egg chamber leads to localization of serine protease activity and ultimately to spatially specific activation of the Toll receptor in the Drosophila embryo.
The rise of the cosmetic nation: plastic governmentality and hybrid medical practices in Brazil.

In this article, I trace the historical and sociopolitical construction of plastic surgery as a basic health need in Brazil. I argue that plastic surgeons deploy “plastic governmentality” in order to portray their work in public settings as humanitarian in nature, while simultaneously using poor patients as experimental subjects to train new surgeons and develop new techniques. This seemingly contradictory positioning is only possible because aesthetic surgeries are relabeled as reconstructive surgeries, producing a pliable form of statecraft that uses statistics and medical discourse to reinforce the support of the state and civil society for the practice. The form of governance I describe elucidates how the state can become instrumentalized in the benefit of private interests under neoliberalism, and how unprofitable public health needs are rendered invisible by the very biopolitical forms of governance that claim to address those needs.
Spitzer Observations of The H II Region NGC 2467: An Analysis of Triggered Star Formation

We present new Spitzer Space Telescope observations of the region NGC 2467, and use these observations to determine how the environment of an H II region affects the process of star formation. Our observations comprise IRAC (3.6, 4.5, 5.8, and 8.0 μm) and MIPS (24 μm) maps of the region, covering approximately 400 arcmin2. The images show a region of ionized gas pushing out into the surrounding molecular cloud, powered by an O6V star and two clusters of massive stars in the region. We have identified as candidate young stellar objects (YSOs) 45 sources in NGC 2467 with infrared excesses in at least two mid-infrared colors. We have constructed color-color diagrams of these sources and have quantified their spatial distribution within the region. We find that the YSOs are not randomly distributed in NGC 2467; rather, over 75% of the sources are distributed at the edge of the H II region, along ionization fronts driven by the nearby massive stars. The high fraction of YSOs in NGC 2467 that are found in proximity to gas that has been compressed by ionization fronts supports the hypothesis that a significant fraction of the star formation in NGC 2467 is triggered by the massive stars and the expansion of the H II region. At the current rate of star formation, we estimate at least 25%-50% of the total population of YSOs formed by this process.
Motion-enhanced, differential interference contrast video microscopy using a GPU and CUDA

Optical video microscopy is widely used to observe living cells and their moving parts. The smaller moving parts of the cells, such as vesicles, have low contrast and are often obscured by membranes and cell walls. Large images (1k x 1k) showing many cells are most helpful to the microscopist; limited memory prohibits storing such images for the entire life of a cell. As a result, it is imperative that image enhancement calculations be performed in real time, so that the researcher can observe moving vesicles immediately, rather than by post-processing.The MEDIC algorithm uses background subtraction to remove or at least minimize the effects of the immobile parts of the cell, including the cell wall. With MEDIC, moving objects are visible to the naked eye. In this paper, we extend the MEDIC algorithm to take advantage of fast computing on GPUs.Current mainstream CPUs are not fast enough to execute the MEDIC algorithm in real time with fast cameras. Dedicated image processing boards, made by companies like Matrox Imaging, are faster, but they are also expensive. GPUs, which are designed for rendering video game graphics, are made to perform calculations in parallel, and they can be obtained for a few hundred dollars. While not as fast, they are still well suited to executing the MEDIC algorithm in real time. The GPU can provide a significant speedup over CPU computations, making real time imaging possible with fast cameras for a fraction of the price of dedicated image processing boards.
A GENOMIC PERSPECTIVE ON PROTEIN FAMILIES

In order to extract the maximum amount of information from the rapidly accumulating genome sequences, all conserved genes need to be classified according to their homologous relationships. Comparison of proteins encoded in seven complete genomes from five major phylogenetic lineages and elucidation of consistent patterns of sequence similarities allowed the delineation of 720 clusters of orthologous groups (COGs). Each COG consists of individual orthologous proteins or orthologous sets of paralogs from at least three lineages. Orthologs typically have the same function, allowing transfer of functional information from one member to an entire COG. This relation automatically yields a number of functional predictions for poorly characterized genomes. The COGs comprise a framework for functional and evolutionary genome analysis.
Perceptions of Singles and Single Parents: A Laboratory Experiment1

Two hundred forty undergraduates rated their perceptions of an individual for ajob rrquiring relocation using a 2 x 3 (Gender: Single Male, Single Female Child: No Child, 3Ycar-Old, 6-Year-Old) between-subjects experimental design. Findings indicate that singlc parents are perceived as having a more difficult time adjusting to a move but are also perceived to be more mature than childless singles. Single parents are also more likely to be offered a job that did not require relocation and are more likely to be awarded a meritbased stipend than childless singles. Support was also found for the hypothesized mediating role of perceptions of adjustment and maturity in understanding actions taken toward single parents. The results are discussed in ternis of implications for future research and applied practice.
ITALIAN COLONIZATION OF TRIPOLITANIA

Italian policymakers conceived of vast, empty, “cultivable,''steppe lands in northern Tripolitania which were available for colonization, although Libyans were using them for cereal cultivation and pastoralism. The Italians adapted the principle of state land grants from Islamic law to their colonial land codes, and proceeded to build a colonial domain reserved for Italians. Dispossession of the Libyans was considered in the public interest. They were excluded from even larger areas as Italian settlement expanded.
Experimental and Theoretical Comparison of Pressure Effects on Lipid Bilayer Fluctuations

Cell membrane fluctuations play crucial roles in membrane protein function and cell signaling, yet the specific biophysical mechanisms that control these fluctuations remain poorly understood. Solid-state 2H NMR is a powerful spectroscopic technique that has been used to quantify the free energy penalty of bilayer deformation, as well as the effect of increased osmotic pressure on bilayer properties including the surface area per lipid [1]. These experimental quantities are essential to force-field development and validation for the purpose of accurately modeling lipid bilayers at an atomistic or coarse-grained level. Our hypothesis is that a reformulation of the model used for calculation of segmental order parameters [2] will assist in examination and development of more accurate lipid force fields. This increase in accuracy will in turn lead to more realistic simulations that can provide invaluable insights about membrane bilayer behavior unattainable using other techniques. We carried out a series of concurrent solid-state 2H NMR and molecular dynamics (MD) studies on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayers, a classical lipid model system, to examine the effect of applied surface tension (from −3 to 5 mJ m−2) on membrane behavior. For both experiment and simulation, as surface tension increased, the surface area per lipid decreased. Segmental order parameters were in general agreement between the two techniques. However, we found that MD simulations using the CHARMM c36 lipid force field tend to underestimate the increase in surface area per lipid with increased surface tension compared to 2H NMR-based results. Interestingly, the MD results match well with previous NMR studies that pre-date the mean-torque model used in our work, demonstrating the interplay between experiment and theory necessary for accurate force field development. [1] K.J. Mallikarjunaiah (2011) BJ 100, 98-107. [2] H.I. Petrache (2000) BJ 79, 3172-3192.
A Monte Carlo/simulated annealing algorithm for sequential resonance assignment in solid state NMR of uniformly labeled proteins with magic-angle spinning.

Abstract We describe a computational approach to sequential resonance assignment in solid state NMR studies of uniformly 15 N, 13 C-labeled proteins with magic-angle spinning. As input, the algorithm uses only the protein sequence and lists of 15 N/ 13 C α crosspeaks from 2D NCACX and NCOCX spectra that include possible residue-type assignments of each crosspeak. Assignment of crosspeaks to specific residues is carried out by a Monte Carlo/simulated annealing algorithm, implemented in the program MC_ASSIGN1. The algorithm tolerates substantial ambiguity in residue-type assignments and coexistence of visible and invisible segments in the protein sequence. We use MC_ASSIGN1 and our own 2D spectra to replicate and extend the sequential assignments for uniformly-labeled HET-s(218–289) fibrils previously determined manually by Siemer et al. (J. Biomol. NMR, 34 (2006) 75–87) from a more extensive set of 2D and 3D spectra. Accurate assignments by MC_ASSIGN1 do not require data that are of exceptionally high quality. Use of MC_ASSIGN1 (and its extensions to other types of 2D and 3D data) is likely to alleviate many of the difficulties and uncertainties associated with manual resonance assignments in solid state NMR studies of uniformly labeled proteins, where spectral resolution and signal-to-noise are often sub-optimal.
Ultrafast Picosecond Chronography

The electron-optical streak camera is one of the few instruments capable of directly measuring a picosecond optical signal both linearly and in real time. The goal of this research has been the development of a synchronously operating streak camera system suit-able for use with mode-locked dye laser sources. The major accomplishments of this research are threefold: 1) A complete single-event streak camera system was constructed. The laser source was a mode-locked dye laser and amplifier system producing picosecond pulses with gigawatt powers. The camera was based on a Photochron II streak tube and microchannel plate intensifier. An optical Multichannel Analyzer was used to generate a real-time digital and graphic representation of the picosecond optical event. The system provides a powerful tool for future research in picosecond high excitation and nonlinear processes. 2) A synchronously operating streak camera system was constructed for use with an actively mode-locked R6G dye laser producing tunable picosecond pulses at a repetition rate of 82 MHz. The streak camera was operated at the laser repetition rate by employing a sinusoidal high-voltage RF deflection signal. The high data-accumulation rate was shown to yield a substantial increase in sensitivity and dynamic range over conventional single-event streak cameras. Time resolution was ≈25 ps and appeared to be limited by laser jitter rather than by the streak camera technical time resolution. 3) The viability of the synchronous streak camera for picosecond spectroscopy of solids was demonstrated by performing the first direct time-resolved measurement of bound exciton luminescence in CuCl. Single crystals at 8°K were excited by the frequency-doubled dye laser. The lifetime of the bound exciton of I line was typically ≈130 ps with a formation time of ≈ 10 ps. Excellent signal-to-noise ratios were obtained with excitation energies even as low as 10-13 J per pulse.
Overview: Replication of porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus that causes significant losses in the pig industry, is one of the most important animal pathogens of global significance. Since the discovery of the virus, significant progress has been made in understanding its epidemiology and transmission, but no adequate control measures are yet available to eliminate infection with this pathogen. The genome replication of PRRSV is required to reproduce, within a few hours of infection, the millions of progeny virions that establish, disseminate, and maintain infection. Replication of the viral RNA genome is a multistep process involving a replication complex that is formed not only from components of viral and cellular origin but also from the viral genomic RNA template; this replication complex is embedded within particular virus-induced membrane vesicles. PRRSV RNA replication is directed by at least 14 replicase proteins that have both common enzymatic activities, including viral RNA polymerase, and also unusual and poorly understood RNA-processing functions. In this review, we summarize our current understanding of PRRSV replication, which is important for developing a successful strategy for the prevention and control of this pathogen.