cssi/SciSciGPT-SciSciNet huggingface dataset:
Formation and evolution of protostellar accretion discs - I. Angular-momentum budget, gravitational self-regulation, and numerical convergence

We investigate the formation and early evolution of a protostellar disc from a magnetized pre-stellar core using non-ideal magnetohydrodynamic (MHD) simulations including ambipolar diffusion and Ohmic dissipation. The dynamical contraction of the pre-stellar core ultimately leads to the formation of a first hydrostatic core, after ambipolar diffusion decouples the magnetic field from the predominantly neutral gas. The hydrostatic core accumulates angular momentum from the infalling material, evolving into a rotationally supported torus; this `first hydrostatic torus' then forms an accreting protostar and a rotationally supported disc. The disc spreads out by gravitational instability, reaching $\sim$30 au in diameter at $\sim$3 kyr after protostar formation. The total mass and angular momentum of the protostar-disc system are determined mainly by accretion of gas from an infalling pseudo-disc, which has low specific angular momentum because of magnetic braking; their removal from the protostar-disc system by outflow and disc magnetic braking are negligible, in part because the magnetic field is poorly coupled there. The redistribution of angular momentum within the protostar-disc system is facilitated mainly by gravitational instability; this allows formation of relatively large discs even when the specific angular momentum of infalling material is low. We argue that such discs should remain marginally unstable as they grow (with Toomre $Q\sim 1$-$2$), an idea that is broadly consistent with recent observational estimates for Class 0/I discs. We discuss the numerical convergence of our results, and show that properly treating the inner boundary condition is crucial for achieving convergence at an acceptable computational cost.
Molecular storytelling for online structural biology outreach and education

Knowledge about the structure and function of biomolecules continues to grow exponentially, enabling us to “see” structural snapshots of biomolecular interactions and functional assemblies. At PDB-101, the educational portal of the RCSB Protein Data Bank, we have taken a storytelling approach to make this body of knowledge accessible and comprehensible to a wide community of students, educators, and the general public. For over 20 years, the Molecule of the Month series has utilized a traditional illustrated storytelling approach that is regularly adapted for classroom instruction. Similar visual and interactive storytelling approaches are used to present topical subjects at PDB-101 and full curricular materials and case studies for building a detailed narrative around topics of particular interest. This emphasis on storytelling led to the Video Challenge for High School students, now in its 8th year. In this Article, we will present some of the lessons we have learned for teaching and communicating structural biology using the PDB archive of biomolecular structures.
Toward a National Agenda for Supported Employment

Community-based supported employment programs, as an alternative to traditional facility-based day programs, have changed the nature of vocational services for adults with mental retardation. Numerous demonstrations over the past two decades have unequivocally documented the employment potential of people with mental retardation. Despite these accomplishments, problems persist that may threaten the ultimate effectiveness of the program. In this article a national agenda for supported employment is delineated. Emphasis is placed on expanding the number of individuals in supported employment, promoting consumer choice, implementing the Americans with Disabilities Act, con­ verting segregated day programs, and expanding the number of qualijied personnel.
Increasing the Biological Inspiration of Neural Networks

We describe three extensions of current neural network models in the direction of increasing their biological inspiration. Unlike "classical" connectionism, Artificial Life does not study single disembodied neural networks living in a void but it studies evolving populations of neural networks with a physical body and a genotype and living in a physical environment. Another extension of current models is in the direction of richer, recurrent network structures which allow the networks to self-generate their own input, including linguistic input, in order to reproduce typically human "mental life" phenomena. A third extension is the attempt to reproduce the noncognitive aspects of behavior (emotion, motivation, global psychological states, behavioral style, psychogical disorders, etc.) by incorporating other aspects of the nervous system in neural networks (e.g., sub-cortical structures, neuro-modulators, etc.) and by reproducing the interactions of the nervous system with the rest of the body and not only with the external environment.
Discrete Model Regulation for Systems with Uncertain Dynamics

A Model Regulation approach for contol systems with significant uncertain dynamics is studied. The proposed approach regulates the behavior of the actual control plant to its nominal model so that desirable dynamic performance may be achieved by conventional controllers based on the nominal model in spite of the existence of significant uncertain dynamics. Analysis shows that the success of this approach is guaranteed in low frequency range and depends on the delay angle as well as the natural of the model uncertainty in high frquency range. The stability of the compensated system is also determined by the delay angle and the model uncertainty. A DC servomotor system is chosen as an example to demonstrate the effectiveness of the proposed approach. Computer simulations and experimental results prove that both linear (payload variation) and nonlinear (friction force) uncertain dynamics are compensated by the model regulation approach.
Medico-legal issues in HIV/AIDS in the 21st century.

This chapter focuses on some of the key legal elements relating to human immunodeficiency virus (HIV) infection and AIDS. The AIDS Drug Assistance Program is one of the key government-funded programs that provide AIDS-related drugs to those who could otherwise not afford them. A recent study found that HIV therapies reduce infectivity by 60%. Access to HIV therapies reduces the viral load (or the amount of HIV present in a person’s bloodstream)—a key factor in curbing infectivity and in reducing the ability to transmit HIV. There is now evidence that AIDS, if untreated, affects the cognitive functioning of patients, sometimes quite early in the disease process. AIDS patients should be educated about the common neurological complications of HIV infection, including peripheral neuropathy as well as neurocognitive disorder. The American Medical Association has stated that physicians have an ethical obligation to provide care for patients with HIV infection and AIDS. AIDS has affected all aspects of family life. Injection drug use is responsible for over 30% of the transmission of HIV/AIDS in certain parts of this country, like New York City. It emphasized the need to protect human rights and human dignity in the context of the HIV/AIDS pandemic. Efforts to prevent the spread of HIV have helped decrease the transmission in developed countries. It is learned from experience that coercion in the form of threats, penalty, and discrimination is not an effective tool to prevent the spread of an epidemic such as AIDS.
Plant-soil interactions associated with acid, weathered soils

Plant-soil interactions in weathered soils are so complex that unqualified statements about a suitable pH for plants are risky. Conventional experimental designs and statistical methods may not be appropriate for investigating such complexities. Lime experiments using continuous function designs and observation of plant response to indigenous variability in soil pH permit detailed observations of plant-soil interactions that are frequently not detected. A graphical boundary-line approach to interpreting data can make good sense out of apparent confusion.
Accelerated direct reconstruction of PET parametric images using augmented Lagrangian optimization

Direct estimation of physiologically or biochemically important parameters from raw projection data is challenging in dynamic positron emission tomography (PET) due to the coupling between tomographic image reconstruction and nonlinear kinetic parameter estimation. Optimization transfer algorithms have been previously developed to solve the complex optimization problem. These algorithms, however, can suffer from slow convergence rate. This paper proposes an accelerated iterative algorithm for direct reconstruction of kinetic parameters through variable splitting under the framework of augmented Lagrangian optimization. Similar to the optimization transfer algorithms, the proposed algorithm splits each iteration of direct reconstruction into two separate steps: dynamic image reconstruction and pixel-wise nonlinear least squares kinetic fitting. The unique advantage of the new algorithm is its flexibility to employ any existing reconstruction algorithms in the reconstruction step, which can substantially accelerate the convergence speed. Computer simulations show that the proposed direct algorithm can be efficiently implemented and achieve much faster convergence speed than the optimization transfer algorithm.
Cluster identification in AA5754 aluminium sheets using mathematical morphology analysis.

Summary Quantitative image analysis of particle distribution in the microstructure of continuous cast (CC) and direct chill cast (DC) AA5754 aluminium alloy sheets have been conducted. This information can be used as an input for modelling mechanical deformation and instability in these materials. The quantitative analysis reveals that there are significant differences in the microstructure of the two materials even though the total content of second-phase particles is statistically similar. Qualitative observation shows the second-phase particles to be arranged in the form of streaks parallel to the rolling direction in the CC sheets and in a uniform random manner in the DC sheets. The main difference in the geometric microstructure of the CC and DC material is the spatial arrangement of the second-phase particles. A new mathematical technique called proximity analysis is developed to identify clusters and group of particles belonging to a cluster. Quantification through proximity analysis reveals that the particle clusters in CC sheet are in the form of long clusters (streaks) parallel to the rolling direction and are significantly longer than those in DC sheets (with the largest cluster in CC being four times larger than DC), and also have anisotropic angular orientation parallel to the rolling direction. The lower value of fracture strain observed in the CC sheets compared to DC sheets is attributed to a combination of large sizes of clusters and their preferential alignment along the rolling direction in the CC microstructure.
Using Suffix Trees for Gapped Motif Discovery

Gibbs sampling is a local search method that can be used to find novel motifs in a text string. In previous work [8], we have proposed a modified Gibbs sampler that can discover novel gapped motifs of varying lengths and occurrence rates in DNA or protein sequences. The Gibbs sampling method requires repeated searching of the text for the best match to a constantly evolving collection of aligned strings, and each search pass previously required θ(nl) time, where l is the length of the motif and n the length of the original sequence. This paper presents a novel method for using suffix trees to greatly improve the performance of the Gibbs sampling approach.
Visual Processing in the Primate Brain

The visual system is the most widely studied and perhaps the best understood mammalian sensory system. Not only have the details of its anatomical features been well described, but the behavior of it neurons have also been characterized at many stages of the neural pathway. This chapter focuses on the visual system of nonhuman primates and deals with the way the primate visual system performs the analysis of various attributes of the visual image and then integrates these attributes into a percept of a visual scene. It shows how such fundamental dimensions of visual stimuli as spatial and temporal variations in luminance and chromaticity are first encoded at the level of the retina, and the manner in which the encoding of other more complex stimulus features, such as motion, complex form and depth, emerge at the level of visual cortex. Finally, modulation of visual cortical activity by such cognitive phenomena as memory and attention are discussed. Keywords: dorsal visual stream; lateral geniculate nucleus; neurophysiology; nonhuman primates; parietal cortex; retina; striate cortex; temporal cortex; ventral visual stream
Manufacturing and applications of polymer and ceramic MEMS from a novel material process for harsh environments

This paper summarizes very recent developments in the MEMS application of a novel material-class, manufactured by new processing methods. This technology has two unique aspects: (1) The materials form a continuum from high temperature polymers to ultrahigh temperature ceramics. We call them polymer-derived-ceramics (PDCs). In addition to being mechanically robust and chemically inert, the PDCs can be functionalized to embody electronic, optical and magnetic properties. (2) PDC-MEMS are processed from liquid precursors by a simple UV photolithographic photo-curing process. Multilayer structures can be made by stereo lithography or by simple bonding of the polymer structures. The PDC-MEMS technology will be demonstrated by two examples: an optical grating made from the transparent polymer version of the PDC, and a microigniter operating at 1300-1500°C made from the ceramic version. A special feature of the Colorado work is the development of a real-time human-machine-interface (HMI) along-side the design and testing of the MEMS devices. For example, a live HMI for the microigniter gives information such as tip temperature, remaining life and damage accumulation. Finally, the PDC-MEMS technology is inexpensive.
Limits of National Discourse on a Transnational Phenomenon A Case Study of Immigration Framing in the BBC Online

/ Although global migration is a complex transnational issue, media and policy discussions in wealthy regions often isolate immigration discourse within national frameworks. Using a Special Report on the BBC Online as a case study (and a ‘best case’ example of immigration reporting), this article illustrates the problems that are masked by ‘objective’ language used within the realm of national identity, and calls for media and policy researchers dealing with immigration to take a transnational view of societal transformations related to migration. In conducting a qualitative analysis that tests media frames against an established goal, this case study suggests the value of adding a normative aspect to framing research.
Early Evolution of the Assumption of Non-satiation

The paper explores the mostly tacit transmission of the assumption of non-satiation from the outset of classical political economy to the advent of marginal analysis in Great Britain. The evolution of the assumption is traced back to contributions to the philosophy of mind in the early British enlightenment, which provided scientific ground not only to the economic agent's insatiable nature but also to a delusional dynamic of association that challenges the causality between acquisitiveness and pleasure. The paper claims that, because there is evidence that such delusional aspect was known to the early political economists, the assumption of non-satiation might have become a mainstay in economics not only for its scientific status but also as a result of a strategic choice that can only be explained within the political, cultural, and social context in which it was made. Had this been the case, the exportability of the assumption through time and space must be further questioned. The consistent inclusion ...
Abstract 2184: Analysis of human polynucleotide phosphorylase function in human melanoma

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Human polynucleotide phosphorylase (hPNPaseold-35) is an evolutionarily conserved 3′, 5′ exoribonuclease predominantly involved in mRNA degradation. It is a type I IFN-inducible early response gene that was identified as a gene upregulated in terminally differentiated and senescent fibroblasts. Overexpression of hPNPaseold-35 via a replication incompetent adenovirus (Ad.hPNPaseold-35) arrests multiple cancer cell types in the G1 phase of the cell cycle, with cells eventually undergoing apoptosis. A potential mechanism of this growth inhibition and eventual apoptosis induction is the ability of hPNPaseold-35 to selectively degrade c-myc mRNA. This was further proven by the overexpression of c-myc that partially but significantly protects human melanoma cells from Ad.hPNPaseold-35-mediated growth inhibition, indicating that c-myc down-regulation might directly mediate the growth-inhibitory properties of Ad.hPNPaseold-35. Since the protection offered by c-myc overexpression was incomplete, additional targets of hPNPaseold-35 are likely to exist that may play a role in mediating its growth-inhibitory effects. The goal of the present study was to identify these additional candidate genes that may be directly or indirectly regulated by hPNPaseold-35, which would help us better understand the physiological implications of this interesting enzymatic protein. In order to identify the target genes a whole genome cDNA microarray was performed to assess gene expression changes that occur when hPNPaseold-35 was silenced in HO-1 melanoma cells. The genes that are upregulated in the hPNPaseold-35 knockdown cell line might be potential direct degradation targets of hPNPaseold-35 according to our current hypothesis. Finally, validation of these targets may provide us a unique opportunity for defining specific molecules and pathways that may represent new targets of hPNPaseold-35 contributing to its growth-inhibitory effects, which may be further used for developing approaches to enhance its therapeutic efficacy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2184. doi:1538-7445.AM2012-2184
The Evolution of Practice Changes in the Use of Special Observations

In acute psychiatric settings, it is common practice to increase the intensity of observations of patients who present with self-injurious thoughts, who are at risk of injuring others, or who exhibit behaviors that adversely impact the overall milieu. These intense observations are intrusive and may result in untoward stimulation of the patient. Nurses at an urban academic medical center addressed the problem of intrusive and overstimulating levels of observation by developing two practice changes using intuitive knowledge combined with input from current nursing literature. The first change was designed to move from observation to engagement. The second change was designed to decrease patient agitation related to intense observation. This article discusses the potential adverse consequences associated with the use of intense levels of observation and describes two protocols that have contributed to a reduction in the use of seclusion and restraints, as well as staff members' reported perceptions of feeling safer and experiencing improved job satisfaction.
TU‐F‐18A‐08: Effect of Quantum Detection Efficiency and Energy Bin Selection On Contrast‐To‐Noise‐Ratio for Energy‐Resolved Photon‐Counting Detectors

Purpose: Energy-resolved photon-counting detectors have the capability to discriminate photons according to their energies. By using optimal energy weighting factors, the contrast-to-noise-ratio (CNR) of the reconstructed image can be improved. In this work, we investigate how quantum detection efficiency (QDE) affects the determination of the optimal energy threshold bins, and therefore the CNR improvement of photon-counting detectors. Methods: In this simulation study a photon-counting detector, based on Silicon (Si), was investigated. A task-oriented algorithm was used to determine the optimal energy bin setting in order to maximize CNR. Projection-based and Image-based energy weighting techniques were implemented. A 13 mm PMMA phantom with two contrast materials, hydroxyapatite (HA) and iodine (I), at different concentrations (100, 200, and 300 mg/mL for HA and 2, 4, and 8 mg/mL for I) was used. TASMIP algorithm was used to generate the spectrum with 2.7 mm Al filter. Different tube voltages, number of energy bins, and bin widths were investigated. Different thicknesses of Si were also investigated to determine the QDE effect on CNR. Results: CNR increased as the detector material thickness increased until it reached 30 mm for Si thickness such that the CNR value was near to the value predicted by an idealmore » detector. Also, the results indicated that the improvement of CNR due to the QDE is task-dependent when comparing weighted images to photon-counting images. For hydroxyapatite the improvement is approximately 20%, whereas for iodine it is less than 10%. Conclusion: The results showed that the improvement of CNR for an energy-resolved photon-counting detector is highly task-dependent when QDE is taken into account.« less
The effect of strain rate on dislocation multiplication in polycrystalline molybdenum

Abstract Dislocation densities were measured as a function of plastic strain in recrystallized molybdenum tested at strain rates of 2 × 10−5 and approximately 2 × 103 sec−1. Only a small difference in total dislocation density was observed for the two rates, indicating that an increase in strain rate by 108 was accommodated mainly by an increase in the average dislocation velocity rather than in the number of mobile dislocations.
The Royal Geographical Society, E. G. Ravenstein, and a map of eastern equatorial Africa—1877–1883∗

(1992). The Royal Geographical Society, E. G. Ravenstein, and a map of eastern equatorial Africa—1877–1883. Imago Mundi: Vol. 44, No. 1, pp. 106-119.
Prospective Evaluation of Surgeon Physical Examination for Detection of Incisional Hernias

Background Surgeon physical examination is often used to monitor for hernia recurrence in clinical and research settings, despite a lack of information on its effectiveness. This study aims to compare surgeon-reviewed CT with surgeon physical examination for the detection of incisional hernia. Study design General surgery patients with an earlier abdominal operation and a recent viewable CT scan of the abdomen and pelvis were enrolled prospectively. Patients with a stoma, fistula, or soft-tissue infection were excluded. Surgeon-reviewed CT was treated as the gold standard. Patients were stratified by body mass index into nonobese (body mass index Results One hundred and eighty-one patients (mean age 54 years, 68% female) were enrolled. Hernia prevalence was 55%. Mean area of hernias was 44.6 cm(2). Surgeon physical examination had a low sensitivity (77%) and negative predictive value (77%). This difference was more pronounced in obese patients, with sensitivity of 73% and negative predictive value 69%. Conclusions Surgeon physical examination is inferior to CT for detection of incisional hernia, and fails to detect approximately 23% of hernias. In obese patients, 31% of hernias are missed by surgeon physical examination. This has important implications for clinical follow-up and design of studies evaluating hernia recurrence, as ascertainment of this result must be reliable and accurate.
Fast Scan Cyclic Voltammetry as a Novel Method for Detection of Real-Time Gonadotropin-Releasing Hormone Release in Mouse Brain Slices

Pulsatile gonadotropin-releasing hormone (GnRH) release is critical for the central regulation of fertility. There is no method allowing real-time GnRH detection in brain slices. We developed fast-scan cyclic voltammetry (FSCV) using carbon-fiber microelectrodes (CFME) to detect GnRH release and validated it using a biologically relevant system. FSCV parameters (holding potential, switching potential, and scan rate) were determined for stable GnRH detection in vitro , then optimized for GnRH detection in mouse brain slices. Placement of CFMEs in the median eminence (ME) near GnRH terminals allowed detection of both KCl-evoked and spontaneous GnRH release. GnRH release was also detected from GnRH fibers passing near GnRH soma and near fiber–fiber appositions in the preoptic area. No GnRH signal was detected from CFMEs in the ME of hpg mice, which lack GnRH, or in regions not containing GnRH neurons in wild-type mice; application of exogenous GnRH produced a signal similar to that observed for spontaneous/evoked endogenous GnRH release. Using an established mouse model that produces diurnal variations in GnRH neuron activity, we demonstrated corresponding changes in spontaneous GnRH release in the median eminence. These results validate FSCV to detect GnRH in brain slices and provide new information on the sites and amounts of GnRH release, providing insight into its neuromodulatory functions.
Neutron interferometry in a gravity field

Abstract Quantitative understanding of the effects of external forces in three-crystal neutron interferometry is achieved by realizing that the three-crystal system is in fact an eight-path interferometer and not the two-path interferometer of previous descriptions. The approach explains damping of the interferometer oscillations with increasing applied force, even for an ideal unbent crystal and a monochromatic beam.
Distribution of trace elements in streambed sediment associated with mining activities in the upper colorado river basin, colorado, USA, 1995-96

Streambed-sediment samples were collected in the Southern Rocky Mountains physiographic province in the Upper Colorado River Basin in Colorado to characterize the occurrence and distribution of trace elements in mined and nonmined areas of the basin. During October 1995 and September 1996, streambed sediment was collected at 37 sites, and the samples were analyzed for trace elements. The ranges in concentrations of As, Cd, Cu, Pb, and Zn at mining sites generally were orders of magnitude higher than the ranges of concentrations at nonmining sites. Sampling sites located in two predominant rock types in mining areas were not significantly different (p > 0.05) for concentrations of As, Cd, Pb, and Zn. Cu was significantly different (p 0.05) between main-stem sites and tributary sites. Concentrations of As, Cd, Cu, Pb, and Zn exceeded established guidelines for adverse effects on aquatic biota at some sites in the study area. The patterns in concentrations of Cd and Zn, Cd and Pb, and Pb and Zn were highly correlated to one another in this study. Concentrations of trace elements in the <63-μm fraction were higher than in the total particle-size fraction analysis. Comparison of reference sites to sites affected by a mine source indicated that trace-element concentrations initially increased downstream of the source and then gradually decreased in concentration with distance from the source.
Children's concepts: Tools for transforming science teachers' knowledge

This study examined the roles that students' science concepts play in promoting teachers' professional growth. Two cohorts of teachers (N = 26 and 30) participated in the study as part of a constructivist-based graduate course on elementary and middle school science methods. A modified learning cycle was used during course instruction as a framework for teachers to explore sound, light, and electricity. Data on teachers' pedagogical and conceptual growth was obtained from pre- and postconcept maps, journal reflections, and portfolios. Results of the concept map analysis showed that teachers' maps became more integrated and cohesive as seen in the increase of crosslinks, hierarchies, and relationships drawn for each science topic. The journals and portfolios showed that students' science knowledge served as discrepant events that evoked teachers' dissatisfaction with their own content knowledge and motivated them to reconsider their pedagogical practices. Students' concepts also served as change agents, resulting in changes in teachers' views of their roles and instructional behaviors. © 1999 John Wiley & Sons, Inc. Sci Ed83:545–557, 1999.
On the Progenitor of the Type II‐Plateau Supernova 2003gd in M74*

ABSTRACT Hubble Space Telescope (HST) WFPC2 archival F606W and F300W images obtained within 1 year prior to the explosion of the nearby Type II supernova (SN) 2003gd in M74 (=NGC 628) have been analyzed to isolate the progenitor star. The SN site was located using precise astrometry applied to the HST images. Two plausible candidates are identified within 0 \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\farcs$\end{document} 6 of the SN position in the F606W image. Neither candidate was detected in the F300W image. SN 2003gd ap...
Preparation, Structure and Properties of VOx and TiO2 Thin Films By MOCVD

Titanium and vanadium oxide thin films have been prepared in a cold wall low pressure MOCVD system for the study of MOCVD processing of epitaxial oxide films. Films were deposited on Si(111) and sapphire (0001) and (1120) at temperatures from 400 to 800°C. Processing parameter-structureproperty relationship was examined in detail and the result is presented.
Ultra-compact, 0.5-Tb/s parallel-WDM optical interconnect

We discuss a 12-fiber /spl times/ 4-wavelength /spl times/ 10.4-Gbit/s short-distance parallel-wavelength-division-multiplexed optical interconnect. The 0.5-Tbit/s transmitter and receiver assemblies each have a 5 /spl times/ 8-mm footprint and together consume 2.95 W.
Estradiol regulation of thymic lymphocyte function in the rat: Mediation by serum thymic factors

Abstract Estradiol (E 2 ) can depress the function of the thymic lymphocytes. To determine if this response to a gonadal steroid is regulated directly or indirectly, thymic lymphocytes were incubated in vitro for 3 days in the presence of the mitogens concanavalin A (Con A) or phytohaemagglutinin (PHA) + tissue culture media + 20% specific rat serum fractions and pulse labelled with tritiated thymidine. Rat serum fractions were prepared from control, castrate, thymectomized (Tx) and castrate-Tx animals as well as from similar groups of animals treated in vivo for three days with physiological doses of E 2 . It was found that there was a significant enhancement of thymocyte blastogenesis in cultures incubated with castrate rat serum + Con A or PHA vs. control serum cultures ( P 2 to castrate sera in vitro at physiological concentrations failed to depress thymocyte blastogenesis to noncastrate levels. Sera prepared from castrate animals treated with E 2 at physiological concentrations was successful in depressing the blastogenic response to noncastrate levels. Sera from Tx animals did not enhance Con A induced blastogenesis, but the PHA response was significantly increased ( P 2 . It is concluded that thymocyte function is regulated by serum factors which have their origin in the thymus, and that these factors are modulated by the gonadal steroid estradiol.
Airway compromise from nasal obstruction in neonates and infants

Nasal obstruction in neonates can cause significant airway compromise and even be life-threatening. In general, otolaryngologists are familiar with management of the neonate born with choanal atresia but there have been few reports and there are no guidelines for management of the neonate or young infant who presents with nasal obstruction and airway compromise but who does not have choanal atresia (NOWCA). This study demonstrates the difficulty in diagnosis, variability in severity of airway compromise, and delineates the problematic aspects of management.
Comparative hydrolysis behavior of the rare earths and yttrium: the influence of temperature and ionic strength

Abstract In this work two techniques are used to determine hydrolysis constants (β1*(M)) of yttrium and the rare earths (YREEs), where β1*(M)=[MOH2+][H+][M3+]−1. Potentiometric experiments were conducted on time scales as long as 15 min and spectrophotometric experiments were complete on time scales much shorter than 500 ms. The stability constant patterns produced by both procedures are in excellent agreement. Potentiometric results obtained over a temperature range between 25 and 55°C indicate that enthalpies appropriate to YREE hydrolysis can be reasonably approximated as ΔH0(M)=11.3 kcal mol−1 for all YREEs. The dependence of YREE hydrolysis constants on temperature (T), ionic strength (I), and YREE identity (M) can be expressed as log β 1 * M = log 0 β 1 * M − 2.044I 1/2 1+5.52I 1/2 +1.84×10 −3 I −2446 K T+8.204 where the log 0β1*(M) values, appropriate at 25°C and zero ionic strength, are given as follows: log 0β1*(Y)=−7.80, log 0β1*(La)=−8.81, log 0β1*(Ce)=−8.34, log 0β1*(Pr)=−8.32, log 0β1*(Nd)=−8.18, log 0β1*(Sm)=−7.84, log 0β1*(Eu)=−7.76, log 0β1*(Gd)=−7.83, log 0β1*(Tb)=−7.64, log 0β1*(Dy)=−7.59, log 0β1*(Ho)=−7.56, log 0β1*(Er)=−7.52, log 0β1*(Tm)=−7.39, log 0β1*(Yb)=−7.24, log 0β1*(Lu)=−7.27.
S-adenosyl-L-methionine-dependent methyl transfer: observable precatalytic intermediates during DNA cytosine methylation.

S-Adenosyl-l-methionine- (AdoMet-) dependent methyltransferases are widespread, play critical roles in diverse biological pathways, and are antibiotic and cancer drug targets. Presently missing fro...
Morphology of the internal reproductive system of the male and female two-spotted stink bug, Perillus bioculatus (F.) (Heteroptera: Pentatomidae) and the transfer of products during mating

Summary The reproductive systems of male and female Perillus bioculatus are typical for the Pentatomidae. A detailed examination of the spermatheca revealed that the duct assembly acts as a valve. When the valve is open, male secretions pass into the spermathecal pouch, but in the closed position sperm pass through the spermathecal duct extension and enter the spermathecal bulb. Males have a composite ejaculatory bulb that is composed of dorsal and ventral units. The dorsal ejaculatory bulb is formed by tissues that are continuous with the walls of the outer ejaculatory duct. Extensions from the dorsal bulb form the medial and lateral ejaculatory pouches. Ectadenia open into the dorsal bulb and their secretions fill the ejaculatory pouches which increase in volume from 3.5 days post-emergence as the male matures. The ventral ejaculatory bulb is muscular and receives the seminal vesicles. Mesadenia open into the seminal vesicles and their secretions, along with sperm, pass through the ventral ejaculatory b...
Metabolic level and size scaling of rates of respiration and growth in unicellular organisms

Summary 1. Metabolic rate is conventionally assumed to scale with body mass to the 3/4-power, independently of the metabolic level of the organisms being considered. However, recent analyses in a variety of animals and plants indicate that the power (log–log slope) of this relationship varies significantly with metabolic level, ranging from c. 2/3 to 1. 2. Here I show that the scaling slopes of rates of respiration and growth are related to the metabolic level of a variety of unicellular organisms, as similarly occurs for respiration rates in multicellular organisms. 3. The recently proposed ‘metabolic-level boundaries hypothesis’ provides insight into these effects of metabolic level. As predicted, the scaling slopes for resting (endogenous) respiration rate in prokaryotes, algae and protozoans are negatively related to metabolic level; and in protozoans, the scaling slope increases with starvation. Also as predicted, the scaling slopes of growth rate in algae and protozoans are negatively related to growth level. Unexpectedly, opposite effects of starvation on the metabolic scaling slopes of unicellular prokaryotes (compared to that of eukaryotes) may be a spurious result of respiration measurements that did not adequately consider the effects of rapid cell multiplication in prokaryotes with extremely short generation times. 4. Analyses of both unicellular and multicellular organisms show that there is no universal metabolic scaling relationship, and that variation in metabolic scaling relationships is systematically and possibly universally related to metabolic level.
Lack of selectivity of protoporphyrin IX fluorescence for basal cell carcinoma after topical application of 5-aminolevulinic acid: implications for photodynamic treatment

Clinical trials of topical ALA in photodynamic therapy (PDT) of basal cell carcinoma (BCC) show significant recurrence rates. Exogenous 5-aminolevulinic acid (ALA) is converted by intracellular enzymes to photoactive protoporphyrin IX (PpIX) in human tissues. PpIX generates cytotoxic singlet oxygen when irradiated with visible light in the 400–640 nm range. To evaluate variability and heterogeneity in PpIX production by tumors in such trials, and to assess the usefulness of PpIX for marking skin tumors, we measured PpIX fluorescence distribution in BCC after topical application of 20% ALA cream. ALA cream was applied under occlusion for periods ranging from 3 to 18 h (average 6.9 h, SD 4 h) to 16 BCCs. ALA conversion to PpIX in the BCCs was assessed by in vivo photography, ex vivo video fluorescence imaging, and fluorescence microscopy. External macroscopic PpIX fluorescence, as assessed by in vivo and ex vivo imaging, correlated with the clinical presence of BCC. Examination by a digital imaging fluorescence microscope revealed inter- and intratumor fluorescence variability and heterogeneity. PpIX fluorescence corresponding to full tomor thickness was found in six superficial and four nodular tumors, and partial-thickness fluorescence was observed in five nodular tumors, but no PpIX fluorescence was observed in some areas of superficial, nodular and infiltrating tumors. In a significant number of nodular and infiltrating BCCs, topical ALA appeared to provide little or no PpIX in deep tumor lobules. In addition, no selectivity for tumor tissue versus normal epidermis was seen. The grossly brighter external PpIX fluorescence over tumors may be due, therefore, to enhanced penetration through tumor-reactive stratum corneum and to the tumor thickness. The absence of reproducible fluorescence marking of nodular and infiltrating BCC suggests that topical ALA, at least under the present delivery protocols, may not be a reliable regimen for photodynamic treatment of these BCCs.
COMBINATORIAL VECTOR FIELDS AND DYNAMICAL SYSTEMS

In this paper we introduce the notion of a combinatorial dynamical system on any CW complex. Earlier in [Fo3] and [Fo4], we presented the idea of a combinatorial vector field (see also [Fo1] for the one-dimensional case), and studied the corresponding Morse Theory. Equivalently, we studied the homological properties of gradient vector fields (these terms were defined precisely in [Fo3], see also Sect. 2 of this paper). In this paper we broaden our investigation and consider general combinatorial vector fields. We first study the homological properties of such vector fields, generalizing the Morse Inequalities of [Fo3]. We then introduce various zeta functions which keep track of the closed orbits of the corresponding flow, and prove that these zeta functions, initially defined only on a half plane, can be analytically continued to meromorphic functions on the entire complex plane. Lastly, we review the notion of Reidemeister Torsion of a CW complex (introduced in [Re], [Fr]) and show that the torsion is equal to the value at $z=0$ of one of the zeta functions introduced earlier. Much of this paper can be viewed as a combinatorial analogue of the work on smooth dynamical systems presented in [P-P], [Fra], [Fri1, 2] and elsewhere.
The Effect of Music Instruction on Phonemic Awareness in Beginning Readers

The purpose of this study was to determine whether music instruction was related to significant gains in the development of young children's phonemic awareness, particularly in their phoneme-segmentation fluency. Beginning in January 2004 and continuing through the end of April 2004, each of four intact classrooms of kindergarten children (n= 43) from one elementary school were taught music by one of four advanced music-methods students from a nearby university. Kindergarten children (n= 60) at a second elementary school served as the control group. An analysis of the data revealed that kindergarten children who received 4 months of music instruction showed significantly greater gains in development of their phoneme segmentation fluency when compared to children who did not receive music instruction, t=−3.52, df= 101, p= .001. The results support a near-transfer hypothesis that active music-making and the association of sound with developmentally appropriate symbols may develop cognitive processes similar...
A RING-H2 zinc-finger protein gene RIE1 is essential for seed development in Arabidopsis.

RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. A novel gene, RIE1, encoding a RING-H2 zinc-finger protein was identified in Arabidopsis thaliana and is characterized in this paper. RIE1 encodes a predicted protein product of 359 amino acids residues with a molecular mass of 40 kDa, with a RING-H2 zinc-finger motif located at the extreme end of the C-terminus. Characterization of a Dissociation (Ds) insertion line (SGT4559) and a T-DNA insertion line (SRIE1) demonstrated that disruption of RIE1 is embryo-lethal. SGT4559 heterozygous plants produced seeds with embryo development arrested from globular to torpedo stages. Some mutant seeds were rescued by embryo culture, and the mutant (rie1) plants seemed to grow normally compared to wild-type plants, except that the mutants produced only abnormal seeds. However, RIE1 was expressed in different tissues throughout the whole plant as revealed by northern blot analysis and gene fusion assay of RIE1 promoter with the β-glucuronidase (GUS) gene. Our results indicated that RIE1 plays an essential role in seed development.
Statistical Analysis of Piloted Simulation of Real Time Trajectory Optimization Algorithms

This short paper describes a simulation of time-optimal intercept algorithms designed for on-board computation of control commands. The simulation tests the effect of three different display modes and two different computation modes on the pilots' ability to intercept a moving target in minimum time.
The Religious Basis of Culture: T. S. Eliot and Simone Weil

When T. S. Eliot wrote his preface to Simone Weil's The Need for Rootsin 1952 his own fame helped launch the book to a prominent place in the Englishspeaking world. The preface despite its warm admiration for Simone Weil, however, says little about the content of the book. What it does do is praise Weil as a balanced thinker who is ‘more truly a lover of order and hierarchy than most of those who call themselves conservative, and more truly a lover of the people than most of those who call themselves Socialist’. Since Eliot's stated intention in the preface was merely to get the reader to hold his prejudices in check and to be patient with those of Weil what he wrote was perhaps sufficient. Yet one wishes that he had said more; not to tease out further comments from one so celebrated but because Eliot himself had spent a certain amount of time thinking and writing on many of the problems which The Need for Roots addresses. His efforts are found in two monographs. The Idea of a Christian Society and Notes Towards the Definition of Culture which have been collected and published as Christianity and Culture.
Synthetic simultaneity – natural and artificial

Abstract In control loops, each element introduces time delays. If those time delays are larger than the critical times for control of the system, a problem exists. I show a simple approach to mitigating this problem by basing the controller's decisions not on the observations themselves but on our projections as to what the observations will be at the time our controls reach the controlled system. Finally, in the appendix, I argue that synthetic simultaneity explains Libet's results better than Libet's explanation.
Calculation of the Ionization Potentials and Electron Affinities of Bacteriochlorophyll and Bacteriopheophytin via ab Initio Quantum Chemistry

Ionization potentials (IP) and electron affinities (EA) are calculated for bacteriopheophytin (BPh) and bacteriochlorophyll (BChl) in the photosynthetic reaction center utilizing density functional methods implemented in a parallel version of the JAGUAR electronic structure code. These quantities are studied as a function of basis set size and molecular geometry. The results indicate the necessity of using large basis sets with diffuse functions in order to obtain reliable IP and EA in the gas phase. The relative reduction potentials of BChl and BPh in dimethylformamide solution are also calculated and compared with experimental results. Excellent agreement between theory and experiment is obtained when ligand binding of solvent molecules to the central Mg atom of BChl is incorporated in the calculations.
“I Go to Fight for Social Justice”: Children as Revolutionaries in the Mexican Revolution, 1910–1920

The Mexican Revolution of 1910 was the explosive culmination of decades of economic transformation under the modernization program of Porfirio Diaz. Governmental policies intended to “modernize” Mexico led to tragic results for the majority of the population, especially the rural poor. Paradoxically, along with its often indiscriminate violence and destruction, the revolution also served as a creative force, planting in the era's children, for instance, the seeds of a deeply held belief in social justice. The youngsters shared with their elders a sense that the revolution would ultimately bring about a more just and equitable society. In addition, the revolution left a legacy of symbols and myths that constructed a national archetype—the child as revolutionary and the revolutionary as child.
Genetic variation of capsule/LPS biogenesis in two serogroup O31 Vibrio cholerae isolates

Both NRT36S and A5 are NAG-ST-producing, serogroup O31 Vibrio cholerae. NRT36S is encapsulated and causes diarrhea when administered to volunteers; A5 is unencapsulated and does not colonize or cause illness in humans. The capsule/LPS (CPS/LPS) biogenesis regions in these two isolates were similar except that a 6.5-kb fragment in A5 has replaced a 10-kb fragment in NRT36S in the middle of the CPS/LPS gene cluster. Although the genes of the replaced region were homologous to genes from other CPS/LPS, they had little similarity to NRT36S and were not homologous to genes from other Vibrios. Data of this study highlight the apparent mobility within the CPS/LPS region that would provide a basis for the large number of observed V. cholerae serogroups and the emergence of novel epidemic strains.