cssi/SciSciGPT-SciSciNet huggingface dataset:
Improving Techniques in Statically Equivalent Serial Chain Modeling for Center of Mass Estimation

Any articulated system of rigid bodies defines a statically equivalent serial chain (SESC). The SESC is a virtual chain that terminates at the center of mass (CoM) of the original system of bodies. An SESC may be generated experimentally without knowing the mass, CoM, or length of each link in the system given that its joint angles and overall CoM may be measured. This paper presents three developments toward recognizing the SESC as a practical modeling technique. Two of the three developments improve utilizing the technique in practical applications where the arrangement of the joints impacts the derivation of the SESC. The final development provides insight into the number of poses needed to create a usable SESC in the presence of data collection errors. First, modifications to a matrix necessary in computing the SESC are proposed, followed by the experimental validation of SESC modeling. Second, the problem of generating an SESC experimentally when the system of bodies includes a mass fixed in the ground frame are presented and a remedy is proposed for humanoid-like systems. Third, an investigation of the error of the experimental SESC versus the number of data readings collected in the presence of errors in joint readings and CoM data is conducted. By conducting the method on three different systems with various levels of data error, a general form of the function for estimating the error of the experimental SESC is proposed.
Three Dimensional Structure of the MqsR:MqsA Complex: a Novel TA Pair Comprised of a Toxin Homologous to RelE and an Antitoxin with Unique Properties

One mechanism by which bacteria survive environmental stress is through the formation of bacterial persisters, a sub-population of genetically identical quiescent cells that exhibit multidrug tolerance and are highly enriched in bacterial toxins. Recently, the Escherichia coli gene mqsR (b3022) was identified as the gene most highly upregulated in persisters. Here, we report multiple individual and complex three-dimensional structures of MqsR and its antitoxin MqsA (B3021), which reveal that MqsR:MqsA form a novel toxin:antitoxin (TA) pair. MqsR adopts an α/β fold that is homologous with the RelE/YoeB family of bacterial ribonuclease toxins. MqsA is an elongated dimer that neutralizes MqsR toxicity. As expected for a TA pair, MqsA binds its own promoter. Unexpectedly, it also binds the promoters of genes important for E. coli physiology (e.g., mcbR, spy). Unlike canonical antitoxins, MqsA is also structured throughout its entire sequence, binds zinc and coordinates DNA via its C- and not N-terminal domain. These studies reveal that TA systems, especially the antitoxins, are significantly more diverse than previously recognized and provide new insights into the role of toxins in maintaining the persister state.
Fabrication of a stable record base for severe soft tissue undercuts in the edentulous patient

Severe soft tissue undercuts in the edentulous patient present a challenge when trying to fabricate a stable record base (Fig. 1). Traditionally, these undercuts are blocked out with wax and the resulting record base is unstable in the mouth once the wax is lost. When treating cases with severe soft tissue undercuts, some means of block out must be used to allow the rigid record base to go on and off of the master cast without damaging the stone surface.1 This article describes a procedure to block out undercuts with a resilient material that becomes part of the record base and engages the undercuts in the mouth to provide a more stable record base. This procedure is compatible with both old and new record base materials. PROCEDURE 1. Paint the master cast with a separating medium (Al-Cote, Dentsply/Trubyte, York, Pa.) to prevent
SU-FF-T-399: Characterizing Secondary Gamma Fluence From a Scanned Beam Proton Therapy Nozzle

Purpose: Recently, several studies have investigated the use of secondary prompt gamma‐ray emission as a method for dose verification. The purpose of this study was to characterize the secondary prompt gammas produced within a scanned beam proton therapy nozzle. Characterizing the scattered gammas will help determine the prompt gamma fluence created within the treatment nozzle and its proportion to that created within the patient. Method and Materials:Monte Carlo simulations were performed using a model of a clinical scanned‐beam treatment nozzle to investigate the gamma fluence at the end of the nozzle. Energy spectrums were calculated for low, medium and high proton beam energies at the isocenter and several points off‐axis. The energy peaks from the spectrum were used to identify specific nozzle elements responsible for the scatteredphotons. The simulations were also performed with a tissue phantom placed at the isocenter to estimate the ratio of scatteredgammas radiation from the nozzle to scatteredradiation from the patient. Results: Calculated results show that the gamma fluence created in the nozzle is 1% of the gamma fluence created by the patient at isocenter. The gamma fluence from the tissue phantom falls off more quickly than the nozzle gamma fluence as you move laterally away from isocenter, resulting in up to 7% of the total gamma fluence coming from the nozzle. Conclusion: Based on the proportion of gamma production by the nozzle and the significant oxygen and carbon emission lines from the nozzle, we think that in order to isolate the spectrum emitted from the patient from that emitted from the nozzle, it would be necessary to shield the detector from the prompt gamma produced in the nozzle.
Disruption of auditory spatial working memory by inactivation of the forebrain archistriatum in barn owls

Barn owls not only localize auditory stimuli with great accuracy, they also remember the locations of auditory stimuli and can use this remembered spatial information to guide their flight and strike. Although the mechanisms of sound localization have been studied extensively, the neurobiological basis of auditory spatial memory has not. Here we show that the ability of barn owls to orient their gaze towards and fly to the remembered location of auditory targets is lost during pharmacological inactivation of a small region in the forebrain, the anterior archistriatum. In contrast, archistriatal inactivation has no effect on stimulus-guided responses to auditory targets. The memory-dependent deficit is evident only for acoustic events that occur in the hemifield contralateral to the side that is inactivated. The data demonstrate that in the avian archistriatum, as in the mammalian frontal cortex, there exists a region that is essential for the expression of spatial working memory and that, in the barn owl, this region encodes auditory spatial memory.
IMPACT OF ACID FOG AND OZONE ON COASTAL RED SPRUCE

High levels of ozone and acidic fog have been measured along the coast of Maine, U.S.A. Some of the ozone and nitrate are a consequence of direct transport from East Coast metropolitan centers, but we discuss evidence supporting N2O5, and perhaps ozone, generation at forested sites from NOx precursors. Fogs with pH below 3.3 occur with greatest frequency in the mid-coast region. Ozone is consistently highest along the southwest coast, but peak hourly averages are often highest in the mid-coast. Historical evidence suggests an increase in fog acidity and nitrate levels, but no change in sulphate within the past 48 years. Red spruce with decline symptoms can be observed from the south-coast to mid-coast region, with the greatest symptom development in the mid-coast. Trees in the mid-coast on soils with high base saturation and Ca/Al ratios develop symptoms of late winter injury (reddening and casting of current year needles in late winter and spring). Trees on poorer soils develop chlorosis on upper surfaces of older needles. Nutrient analysis of soils and foliage reveals differences between stressed and unstressed sites. Scanning electron microscopy of needle surfaces also reveals response differences between pollutant stressed and unstressed trees. Hypotheses and research directions are discussed.
Regulation of Protein Function and Signaling by Reversible Cysteine S-Nitrosylation

NO is a versatile free radical that mediates numerous biological functions within every major organ system. A molecular pathway by which NO accomplishes functional diversity is the selective modification of protein cysteine residues to form S-nitrosocysteine. This post-translational modification, S-nitrosylation, impacts protein function, stability, and location. Despite considerable advances with individual proteins, the in vivo biological chemistry, the structural elements that govern the selective S-nitrosylation of cysteine residues, and the potential overlap with other redox modifications are unknown. In this minireview, we explore the functional features of S-nitrosylation at the proteome level and the structural diversity of endogenously modified residues, and we discuss the potential overlap and complementation that may exist with other cysteine modifications.
Engineering direct conversion of CO 2 to biofuel

Genetically engineered cyanobacteria harvest light energy to directly produce isobuteraldehyde and isobutanol.
Horizontal transition from fast to slow structures at the core-mantle boundary; South Atlantic

Recent tomographic studies of the deep mantle have revealed large-scale low-velocity zones beneath Africa and relatively fast velocity zones beneath South America. Here we conduct a concentrated core–mantle boundary (CMB) study across this transition zone from fast to slow beneath the South Atlantic. Deep South American earthquakes recorded in Africa provide S and ScS waveform data at core-grazing distances of 85–105°. The waveform interference pattern produced at these ranges provides an excellent sample of the CMB structure in the vicinity of the ScS bounce point which can be used to map out regions of low-velocity zones ( 10% reductions). The strongest anomalies occur at the western edge roughly beneath the Tristat Plateau with weaker structures to the east beneath the so-called ‘Great Africa Plume’. These results agree with dynamic models where strong local upwellings develop at the edges of D″ (fast) structures.
A Pneumatic Muscle-Actuated Transfemoral Prosthesis

Providing powered joint actuation has been the latest trend in transfemoral prosthesis research. The capability of actively powering the joints enables the prosthesis to meet the energetic requirements of locomotion, and thus provides higher performance in restoring the lost lower limb functions in comparison with traditional passive prostheses. In this paper, a powered transfemoral prosthesis is presented, in which the knee and ankle are powered with pneumatic artificial muscle actuators, leveraging the multiple advantages of this unique actuator (such as large force output and high power density). To address the issue of uneven force capacity, a new variable-radius pulley-based mechanism is utilized, which enables the adjustment of the available actuation torque curve to better match the desired torque curve as dictated by the locomotive requirements. The design details of the prosthesis are presented, and the prosthesis is expected to provide sufficient torque for an 85 kg user in various locomotion modes, including level walking at slow/normal cadence and stair ascent/descent.Copyright © 2012 by ASME
Molecular Structure of P2Y Receptors: Mutagenesis, Modeling, and Chemical Probes.

There are eight subtypes of P2Y receptors (P2YRs) that are activated, and in some cases inhibited, by a range of extracellular nucleotides. These nucleotides are ubiquitous, but their extracellular concentration can rise dramatically in response to hypoxia, ischemia, or mechanical stress, injury, and release through channels and from vesicles. Two subclasses of P2YRs were defined based on clustering of sequences, second messengers, and receptor sequence analysis. The numbering system for P2YR subtypes is discontinuous; i.e., P2Y1–14Rs have been defined, but six of the intermediate-numbered cloned receptor sequences (e.g., P2y3, P2y5, and P2y7–10) are not functional mammalian nucleotide receptors. Of these two clusters, the P2Y12–14 subtypes couple via Gαi to inhibit adenylate cyclase, whereas the remaining subtypes couple through Gαq to activate phospholipase C. Collectively, the P2YRs respond to both purine and pyrimidine nucleotides in the form of 5′-mono- and dinucleotides and nucleoside-5′-diphosphosugars. In recent years, the medicinal chemistry of P2YRs has advanced significantly to provide selective agonists and antagonists for many but not all of the subtypes. Ligand design has been aided by insights from structural probing using molecular modeling and mutagenesis. Currently, the molecular modeling of the receptors is effectively based on the X-ray structure of the CXCR4 receptor, which is the closest to the P2YRs among all the currently crystallized receptors in terms of sequence similarity. It is now a challenge to develop novel and selective P2YR ligands for disease treatment (although antagonists of the P2Y12R are already widely used as antithrombotics). WIREs Membr Transp Signal 2012, 1:815–827. doi: 10.1002/wmts.68 For further resources related to this article, please visit the WIREs website.
Analysis of C3b/C4b receptor (CR1) polymorphic variants by tryptic peptide mapping☆

The human C3b/C4b receptor (CR1) binds the major activation and opsonic fragments of the third (C3) and fourth (C4) components of complement. CR1 is a single chain integral membrane glycoprotein widely distributed on peripheral blood cells. Four codominantly inherited allelic variants with Mrs of 160,000, 190,000, 220,000 and 250,000 have been described. To address the structural basis for this unusual polymorphism, CR1 from donors expressing three of the four allelic variants was purified from surface labeled (125I) erythrocytes by iC3-Sepharose affinity chromatography and the variants compared by tryptic peptide mapping (TPM). The TPMs of each variant contained the same major peaks and minor peak areas and were nearly identical to one another. Tryptic peptide mappings of the 190,000 Mr erythrocyte CR1, which was purified prior to iodination, were similar to those derived from surface iodinated CR1. The TPMs of erythrocyte and granulocyte CR1 from the same donor differed by a single peak of increased prominence in the granulocyte map. These results indicate a conservation in amino acid sequence for those peptides detected. In view of these data and those of other studies of the structure and genetics of CR1 and related proteins, it is suggested in this paper that the allelic variation relates to CR1, being composed of repeating amino acid sequences.
BLACK OCCUPATIONAL CHANGE AND EDUCATION

A study of census data shows that differences in the occupational distribution of the male and nonwhite male labor force in the United States have declined slightly between 1950 and 1970, both overall and within educational groups. However, differences in level of schooling or test achievement between whites and nonwhites cannot explain the underrepresentation of nonwhites in managerial, sales, and skilled manual occupations. The proportionate representation of nonwhites in occupations, instead, is a function of the income of the occupation relative to its educational prerequisites. Equal recruitment of educationally qualified nonwhites into skilled crafts and managerial jobs would significantly upgrade the occupational and income status of about fifteen percent of the nonwhite male labor force.
The neuroscience of investing: fMRI of the reward system

Functional magnetic resonance imaging (fMRI) has proven a useful tool for observing neural BOLD signal changes during complex cognitive and emotional tasks. Yet the meaning and applicability of the fMRI data being gathered is still largely unknown. The brain's reward system underlies the fundamental neural processes of goal evaluation, preference formation, positive motivation, and choice behavior. fMRI technology allows researchers to dynamically visualize reward system processes. Experimenters can then correlate reward system BOLD activations with experimental behavior from carefully controlled experiments. In the SPAN lab at Stanford University, directed by Brian Knutson Ph.D., researchers have been using financial tasks during fMRI scanning to correlate emotion, behavior, and cognition with the reward system's fundamental neural activations. One goal of the SPAN lab is the development of predictive models of behavior. In this paper we extrapolate our fMRI results toward understanding and predicting individual behavior in the uncertain and high-risk environment of the financial markets. The financial market price anomalies of "value versus glamour" and "momentum" may be real-world examples of reward system activation biasing collective behavior. On the individual level, the investor's bias of overconfidence may similarly be related to reward system activation. We attempt to understand selected "irrational" investor behaviors and anomalous financial market price patterns through correlations with findings from fMRI research of the reward system.
Paper disc estimation of radioactive RNA: studies on the presence and elimination of metabolically generated artifacts from labeled purine and pyrimidine precursors.

Abstract Conventional usage of the filter-paper disc technique following in vivo hepatic incorporation of certain labeled pyrimidine and purine RNA precursors resulted in the presence of radioactivity on the filter disc in species other than RNA. Thus the filter paper disc technique, conventionally conducted, may be misleading. To eliminate artifacts, it is proposed that replicate filter discs be processed, one group passing through the usual cold TCA washings only, while a parallel group of replicate discs are heated for 20 min at 90°C in 5% TCA to remove RNA. True RNA radioactivity is the difference of counts from the cold TCA precipitable material and the radioactivity remaining after hot TCA extraction.
Anomalous X-ray pulsars and soft gamma-ray repeaters – the connection with supernova remnants

Abstract Many of the properties of anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are still a matter of much debate, as is the connection (if any) between these two groups of sources. In cases where we can identify the supernova remnant (SNR) associated with an AXP or SGR, the extra information thus obtained can provide important constraints as to the nature of these exotic objects. In this paper, I explain the criteria by which an association between a SNR and an AXP/SGR should be judged, review the set of associations which result, and discuss the implications provided by these associations for the ages, environments and evolutionary pathways of the AXPs and SGRs. There are several convincing associations between AXPs and SNRs, demonstrating that AXPs are young neutron stars with moderate space velocities. The lack of associations between SGRs and SNRs implies that the SGRs either represent an older population of neutron stars than do the AXPs, or originate from more massive progenitors.
Information technology and the university: integration strategies for the 21st century

The revolution in information technology requires that universities integrate information technology with their traditional missions of teaching, research, and public service. To this end, universities must address ethical and legal issues and restructure themselves to better meet the needs of today's learners. In addition, new information technologies are creating new patterns in the research enterprise, with networks enhancing information sharing and data transmittal. Leadership and service are critical to strategies for tomorrow
The effect of fabric structure and yarn-to-yarn liquid migration on liquid transport in fabrics

Wicking experiments were carried out on a range of cotton and polyester fabrics, which exhibited differences in terms of yarn size, thread spacing, and yarn type. Wicking coefficients in the warp and weft direction as well as for the constituent warp and weft yarns were determined using image analysis technique in which height of liquid front was measured as a function time. Results showed that the wicking in fabrics is determined by the wicking behavior of the yarns, the thread spacing, and, more importantly, the rate at which liquid migrates from longitudinal to transverse threads and again from transverse threads back to longitudinal threads. This yarn migration phenomenon, which has not received significant attention in the past, was studied by measuring the gain in wicking coefficient and the equilibrium wicking height and by actual visualization of the wicking process. Fabric wicking rates were found to be directly associated with yarn wicking behavior. Inter-yarn spaces were found to exert a major ...
Evaluation of η in Wilson's Incomplete-Integration Method: Independence of Cutoff Parameters to Order ε 2

The expression for the coefficient of ${\ensuremath{\epsilon}}^{2}$ in the $\ensuremath{\epsilon}$ expansion for the critical exponent $\ensuremath{\eta}$ of the Ising model has been obtained by Shukla and Green within the incomplete-integration method of Wilson. It was left by them in the form of an unevaluated integral, which appears to depend on parameters characterizing details of the renormalization-group procedure. The integral is evaluated here and found to equal $\frac{1}{54}$, regardless of the values of those parameters.
The Unstructured Clinical Interview

In mental health, family, and community counseling settings, master's-level counselors engage in unstructured clinical interviewing to develop diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR; American Psychiatric Association, 2000). Although counselors receive education about diagnosis and the DSM classification system, the majority of them are not specifically trained in clinical interviewing. This article provides information about using the unstructured clinical interview to make a DSM-IV-TR diagnosis for adult clients with Axis I and Axis II disorders.
Exploring “Meka's method” to achieve effective teaching and training outcomes

Purpose – The purpose of this paper is to explore Meka's method – an innovative teaching and training tool to teach and train students and trainees effectively to achieve desired teaching and training takeaways. Design/methodology/approach – The methodology is gleaned from the author's 31 years of practical experience in industry, teaching, training, research and consultancy. It places emphasis on the need to take feedback from students through their body language and mould their teaching style accordingly during the teaching session to create a compatibility and chemistry with the students. It explains humor quotient and elaborates Just a minute (JAM) session. It enlightens 80:20 teaching based on Pareto's Principle. Findings – The paper unveils tools to inspire students and unfolds teaching techniques. It implores teachers to unlearn, relearn and learn to remain relevant and competent in the current context. Research limitations/implications – Qualitative/action research inevitably needs to be backed up...
In vivo measures of dopaminergic radioligands in the rat brain: Equilibrium infusion studies

The application of an equilibrium infusion method for measuring specific in vivo radioligand binding in the conscious rat brain was evaluated for two ligands of the dopaminergic system, (+)-α-[11C]dihydrotetrabenazine (DTBZ) and d-threo-[11C]methylphenidate (MePhen). Both radioligands can be successfully utilized to reach equilibrium distributions in rat brain within 1 h; combinations of tritiated and carbon-11-labeled radiotracers can furthermore be used to obtain simultaneous measures of the neuronal membrane dopamine transporter (using [3H]MePhen) and vesicular monoamine transporter (using [11C]DTBZ) in the same animal. These studies provided quantitative measures of distribution volume ratios, which represent specific radioligand binding. Stereospecificity of in vivo binding was demonstrated using equilibrium infusions of the low-affinity isomers of each ligand, (−)-α-[11C]dihydrotetrabenazine (DTBZ) and l-threo-[11C]methylphenidate, both of which produced uniform brain distributions and no specific binding. Specific binding of (+)-α-[11C]dihydrotetrabenazine was blocked by co-infusion of tetrabenazine, but was unaffected by administration of methylphenidate, haloperidol, or apomorphine. Specific binding of d-threo-[11C]methylphenidate, conversely, was blocked with unlabeled methylphenidate but not affected by tetrabenazine or the dopamine receptor ligands. Equilibrium measures of in vivo radioligand binding, as utilized in this study, offer a quantitative means to evaluate acute and chronic drug effects on in vivo radioligand binding in the rat brain. Synapse 43:188–194, 2002. © 2002 Wiley-Liss, Inc.
Stimulant use among African American and Latino MSM social networking users.

High stimulant-using and at-risk HIV populations, such as African American and Latino men who have sex with men (MSM), are increasingly using social networking technologies. However, no known research has explored associations between stimulant use, sexual risk behaviors, and social networking among these populations. Participants were recruited using the Facebook Connect software application, which narrowed the sample to 118 (primarily African American and Latino MSM) active Facebook users. Participants completed demographic, Internet and social media use, and drug use survey items. Participants reported high rates of cocaine and methamphetamine use (both more than 15% within the past 12 months). More than 70% of participants reported using social networking technologies to meet people, and more than 30% used them to find sexual partners. A multivariate logistic regression showed that (1) participants using social networks to find sexual partners were more likely to have used methamphetamines within the ...
Reduction potentials of heterometallic manganese–oxido cubane complexes modulated by redox-inactive metals

Understanding the effect of redox-inactive metals on the properties of biological and heterogeneous water oxidation catalysts is important both fundamentally and for improvement of future catalyst designs. In this work, heterometallic manganese–oxido cubane clusters [MMn3O4] (M = Sr2+, Zn2+, Sc3+, Y3+) structurally relevant to the oxygen-evolving complex (OEC) of photosystem II were prepared and characterized. The reduction potentials of these clusters and other related mixed metal manganese–tetraoxido complexes are correlated with the Lewis acidity of the apical redox-inactive metal in a manner similar to a related series of heterometallic manganese–dioxido clusters. The redox potentials of the [SrMn3O4] and [CaMn3O4] clusters are close, which is consistent with the observation that the OEC is functional only with one of these two metals. Considering our previous studies of [MMn3O2] moieties, the present results with more structurally accurate models of the OEC ([MMn3O4]) suggest a general relationship between the reduction potentials of heterometallic oxido clusters and the Lewis acidities of incorporated cations that applies to diverse structural motifs. These findings support proposals that one function of calcium in the OEC is to modulate the reduction potential of the cluster to allow electron transfer.
Beyond the Many Faces of Price: An Integration of Pricing Strategies:

The author reviews the field of pricing strategy and constructs a unifying taxonomy of the many strategies described in the literature. The taxonomy is based on the simple proposition that all the ...
Field Emission from Bismuth and Tungsten in a Magnetic Field

Detailed calculations of magnetic-field-induced quantum effects in bismuth are described. In agreement with previous calculations, it is found that 10% fluctuations in the field-emission current can be expected at moderate fields if only the conduction electrons contribute to the field-emitted current. The magnitude of the fluctuations decreases significantly if other bands contribute to the field-emission current. In particular, when the contribution from the hole band is included in the calculations for a magnetic field parallel to the trigonal axes, the magnitude of the magnetic-field-induced fluctuations is reduced to 0.23%. Two experimental attempts to observe quantum effects are described. In the first, the current was measured as a function of magnetic field for fields up to 45 kG. In the second, the magnetic field was modulated and the in-phase fluctuations of the field-emission current were measured. No dc magnetic-field-induced quantum effects larger than 0.5% were observed from bismuth or tungsten and no fractional current changes larger than 2 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}4}$ were observed for a 40-G-rms field modulation. Both techniques had sufficient sensitivity to measure effects had the conduction band been the only contributor to the field-emission current. These null experimental results support the theoretical prediction that other bands besides the conduction band would reduce the relative magnitude of the magnetic-field-induced effects. Another experimental technique in which the magnetic-field-induced fluctuations would be enhanced to measureable values is proposed.
Nanostructure Dependence of Field-Effect Mobility in Regioregular Poly(3-hexylthiophene) Thin Film Field Effect Transistors

Low polydispersity regioregular polythiophenes with number average molecular weights ranging from 2 to 13 kDa were cast under the same conditions from solution to form a series of field effect transistors (FETs). Tapping mode AFM and grazing incidence small-angle X-ray scattering revealed that in all cases the polymers formed regular nanofibrillar morphologies with the width of nanofibrils proportional to the weight average contour length of polymer chains, indicating that conjugated backbones were oriented perpendicular to the nanofibril axes. FET charge carrier mobilities exhibited exponential dependence on nanofibril width, pointing to the decisive role of extended conjugated pathways in charge transport.
The Stability Behavior of Sol-Emulsion Systems

Abstract The stability characteristics of mixed aqueous dispersions of titanium dioxide and mineral oil emulsion droplets are examined as a function of pH and emulsifier type and content. Knowledge of such behavior is important to strategies for conversion from solvent-based to water-based coatings. The practical goal is to determine conditions leading to selective coagulation between the oil droplets (binder) and pigment particles. Zeta potentials of both the titanium dioxide and the mineral oil particles are measured under all conditions to identify regions of expected heterocoagulation and to quantify the electrostatic boundary conditions. The latter are used in the numerical solution of the pair interaction potentials based on the recent theory of McCormacket al.(J. Colloid Interface Sci.169,177, 1995). The potential functions are used in a modified version of the stability model of Hogg, Healy, and Fuerstenau (Trans. Faraday Soc.62,1638, 1966) to calculate early-stage aggregation rates. Photon correlation spectroscopy is used to determine stability ratios for homo- and heterocoagulation, and initial results indicate good agreement between experiments and computations.
Ploidal level and stomatal size in the American hickories

The chromosome numbers of two diploid species—Cary a aquatica (n = 16), andC. illinoensis (n = 16)—and one tetraploid—C. texana (2n = 64)—are recorded for the first time. Counts ofn = 16 and 2n = 32 forC. cordiformis and2n = 64 forC. tomentosa confirm earlier reports. Positive correlations were validated between ploidal level and stomatal size. All species with small stomata were diploids, and all species with large stomata proved to be tetraploids. Sect.Apocarya C.DC. contains only known or suspected diploids, whereas Sect.Eucarya includes both diploids and tetraploids. The diploids (Caryalaciniosa, C. ovata, andC. carolinaeseptentrionalis) in Sect.Eucarya have several features in common with species in both sections of the genusCarya. Ultimately, it may be shown that these diploids have contributed genomes to the tetraploid species and thus furthered the evolutionary advancement of the genus.
Large-Scale Study Suggests Specific Indicators for Combined Cognitive Therapy and Pharmacotherapy in Major Depressive Disorder

By contrast, combined treatment provided no advantage over pharmacotherapy alone for the subsets of patients with milder depressions and with more chronic depressions, who did as well with pharmacotherapy alone. Combined treatment also offered no particular added benefit for patients with personality disorders, although this group showed slower recoveries regardless of study treatment. These findings illustrate how the results of a larger-scale RCT can complement those derived from meta-analyses of smaller studies. For example, whereas the relatively modest overall advantage of combined treatment is comparable with the findings of meta-analyses of earlier studies, 2,3 meta-analyses of grouped data were not able to identify the clinically important moderating effects of symptom severity and chronicity. Conversely, whereas an earlier pooled analysis of data from 6 smaller studies of MDD by Thase and colleagues 4 similarly found that benefit of combined treatment was much larger for patients with more severe depressive symptoms, the results of the current prospective study provide much stronger evidence of this clini
Thyroid and pituitary hormone responses to TRH in advanced nonalcoholic liver disease

Basal T4, T3, TSH, prolactin and growth hormone levels were determined in several groups: patients with postnecrotic cirrhosis with hepatocellular carcinoma (n = 14); patients with postnecrotic cirrhosis but without hepatocellular carcinoma (n = 26); cholangiolar carcinoma (n = 9); and normal controls age-matched to within 5 yr of the liver disease subjects studied. In addition, TRH stimulation (400 μg TRH) was performed; TSH, prolactin and growth hormone responses over a 180-min time interval were evaluated for each subject. The responses observed varied between liver disease groups. The presence or absence of hepatocellular carcinoma was found to determine, at least in part, the type of response observed. Similarly, the presence or absence of hepatic encephalopathy determined, and/or reflected, at least in part, the type of response observed. Finally, for purposes of continuity, basal and TRH-stimulated levels of TSH, prolactin, growth hormone, T4 and T3 are compared in 3 settings of cirrhosis: alcoholic, nonalcoholic postnecrotic cirrhosis, and postnecrotic cirrhosis with hepatocellular carcinoma.
Secretory and humoral immunologic response of atopic and non‐atopic individuals to intranasally administered antigen

Groups of twelve asymptomatic atopic and fourteen non-atopic individuals were immunized with tetanus toxoid 7.5 Lf units X 2 by means of nasal droplets. Serum and nasal secretion samples were collected on days 1, 15 and 36. Protein content of dialysed secretions was determined by the Lowry method and 1.0 mg/ml samples used for specific antibody assays by passive haemagglutination (PHA) and radioimmunosorption (RISA) employing cyanogen bromide activated Sephadex G-25. IgG, IgA, IgM, and IgD were quantitated by single radial diffusion (SRD), and IgE by the RISA technique. Mean PHA secretion titres rose significantly in both groups during the course of the study. Serum and nasal secretion RISA IgA anti-toxoid levels were higher in the non-atopic group throughout the course of immunization but both groups showed a significant increase in mean levels following immunization (P less than 0.05). Conversely nasal secretion IgE-anti-toxoid levels were significantly higher in the atopic group throughout the course of immunization although no quantitative increase in levels was noted. Total IgG, IgD, IgE, and IgM levels in serum and secretions did not rise during the course of immunization but nasal wash IgA levels rose in both groups. IgD levels were significantly higher in serum and nasal secretions of the atopic group. Our results suggest that atopic and non-atopic individuals differ quantitatively in Ig class specific antibody production following topical mucous membrane immunization.
Solute structure-permeability relationships in human stratum corneum.

Abstract The permeability coefficients (k p ) of a series of methyl-substituted p -cresols were determined in human stratum corneum along with their partition coefficients (PC) between water and untreated stratum corneum, delipidized stratum corneum, octanol, and heptane. The PC values were identical in untreated and delipidized stratum corneum, suggesting that the stratum corneum/water PC data reflect the protein domain rather than the lipids. Although uptake into human stratum corneum was relatively insensitive to solute lipophilicity, reflecting the predominant role of proteins in the uptake, permeability coefficients were found to be more sensitive to lipophilicity, suggesting that transport is by a lipid pathway. A log-log plot of k p versus stratum corneum/ water PC within the phenol series is linear, but with a slope of 3.6, indicating that k p is not directly proportional to PC. Functional group contributions to the free energy of the transfer process reflected in permeability or partitioning experiments were compared with group contribution data generated previously for the same substituents attached to the chain terminus of 21-esters of hydrocortisone. Within experimental error, a given functional group altered permeability by the same factor in either series of compounds. Group contributions of polar, hydrogen bonding substituents obtained from k p data were similar to those from octanol/water PC data, suggesting that the barrier microenvironment resembles that of a hydrogen bonding organic solvent. Comparison of the k p values of substituted p -cresols with those of hydrocortisone esters having similar lipophilicities also indicated a steep dependence of k p on molecular weight (log k p = constant + ψ log PC - n log MW, n=4.6) similar to the dependence observed in other biomembranes and isolated lipid bilayers.
Image feature extraction for mass detection in digital mammography: Influence of wavelet analysis

Rationale and objectives. The objective of this work is to evaluate the importance of image preprocessing, using multiresolution and multiorientation wavelet transforms (WTs), on the performance of a previously reported computer assisted diagnostic(CAD) method for breast cancer screening, using digital mammography.Method: An analysis of the influence of WTs on image feature extraction for mass detection is achieved by comparing the discriminant ability of features extracted with and without the wavelet-based image preprocessing using computed ROC. Three indexes are proposed to assess the segmentation of the mass area with comparison to the ground truth. Data was analyzed on the region-of-interest (ROI) database that included mass and normal regions from digitized mammograms with the ground truth. Results: The metrics for the measurement of segmentation of the mass clearly demonstrated the importance of image preprocessing methods. Similarly, the relative improvement in performance was observed in feature extraction based on the evaluation of the ROC curves, where the Az values are increased, for example, from 0.71 to 0.75 for a pixel intensity feature and from 0.72 to 0.85 for a morphological feature of the Normalized Deviation of Radial Length. The improvement, therefore, depends on the feature characteristics, being large for boundary-related features while small for intensity-related features. Conclusion: The use of image preprocessing modules using wavelet transforms results in a significant improvement in feature extraction for the previously proposed CAD detection method. We are therefore exploring additional improvement in wavelet-based image preprocessing methods, including adaptive methods, to achieve a further improvement in performance and an evaluation on larger imagedatabases.
Regulation of GH secretion in acromegaly: reproducibility of daily GH profiles and attenuated negative feedback by IGF-I.

GH hypersecretion is a hallmark of acromegaly. It is unknown whether the secretory activity of somatotroph adenoma is autonomous or is still governed by central or peripheral mechanisms. In this study we investigated whether GH secretion in acromegaly 1) has a reproducible circadian pattern and 2) is inhibited by exogenous IGF-I. Eleven patients with newly diagnosed acromegaly were studied in 2 protocols. In protocol 1, peripheral blood was sampled every 10 min for 48 h in 6 patients for the determination of concordance between 24-h GH profiles. There was no significant day to day variability in mean 24-h output. There was, however, a significant time effect, and the 24-h GH secretion pattern was maintained between days. In protocol 2, 5 patients were sampled for GH every 10 min twice, once during infusion of normal saline and once during iv infusion of recombinant human IGF-I (10 microg/kg x h). The recombinant human IGF-I infusion increased plasma IGF-I to approximately 230% of the baseline concentration. This resulted in GH suppression (4220 +/- 1950 vs. 3223 +/- 1472 microg/liter.min; P = 0.001), but did not alter GH secretion pattern. There were highly significant cross-correlations for 10 of the 11 of the subjects in the two protocols when the lag was 0 min. By harmonic analysis, nocturnal augmentation of GH was maintained, and maximum daily GH occurred at approximately 2300 h. These data demonstrate that the pattern of GH secretion in acromegaly is not random, but is highly preserved with 24-h periodicity. In addition, negative feedback regulation by IGF-I is preserved, although the degree of negative feedback is grossly attenuated. Thus, secretory activity of somatotroph adenomas is not autonomous or haphazard, but is still subject to both feedback and feedforward regulatory mechanisms.
Theoretical Study of a Nonpeptidic Polydisulfide α-Helix

A carbon–sulfur molecule has been designed as a mimic of peptides. Density functional theory calculations showed that the oxidation of 10 moles of methanedithiol led to a polydisulfide oligomer, HS (CH 2SS)9CH 2SH. The polydisulfide can adopt an α -helix type of secondary structure, where the chain is coiled. Unlike proteins, the S–S bonds in the polydisulfide function as secondary rather than tertiary structural elements. The helix contains 8 non-hydrogen atoms per turn, 2.7 A methylenes per turn, a pitch distance of 8.6 A, and a radius of 1.00 A. The methylene sites could carry R group residues similar to amino acids.
Coping with intergenerational family conflict among Asian American college students

Two coping strategies-problem solving and social support seeking-were hypothesized to differentially moderate the effects of intergenerational family conflict on well-being and adjustment in a college sample of 117 Asian American young adult children. Results indicated that social support served as a protective-stabilizing factor that buffered the effects of family conflict on positive affect and somatic distress. Problem-solving coping served as a protective-reactive factor that had a positive effect on positive affect when family conflict was low and a negative effect when family conflict was high. The potential implications of these findings for counseling and conducting research on Asian American college students are discussed.
Life on a Pixel: Challenges in the Development of Digital Methods Within an “Interpretive” Landscape Archaeology Framework

This paper provides a personal account of the challenges of developing digital methods within an interpretive landscape archaeology framework. It reviews current criticisms leveled against the use of model-based tools, e.g., GIS-based, within this framework. Currently, the absence of, or distance between, methods and theory is considered to be an important limitation when adopting such orientation. This gap is largely due to the particular nature of the theoretical sources informing this framework. This paper suggests the need for middle ground/bridging concepts, i.e., concepts that enable the instantiation within concrete archaeological contexts of various aspects discussed within an interpretative framework, as a way to shorten this gap. It also highlights the importance of the nature of representations when applying digital methods and their key role when producing new archaeological information. Finally, it attempts to elevate the role that model-based methods and simulations can play within an interpretive landscape framework, and to insist on the development of new middle ground solutions (methods and concepts) when existing tools do not meet our theoretical challenges.
Expert Systems in a Social Environment—Human Factors Concerns

There is an abundance of promises for Expert Systems with user-friendly and intelligent interfaces providing cloned expertise for augmented job performance. A closer look reveals that very few systems are in operation, and that there is a serious gap between claims and reality. Basically, “Knowledge Engineering” is a modern form of “Work Study Engineering”, and yet job and organizational design issues are rarely addressed in the literature on designing Expert Systems. This serious gap is discussed.
Non-abelian vortices on surfaces and their statistics

We discuss the physics of topological vortices moving on an arbitrary surface M in a YangMills-Higgs theory in which the gauge group G breaks to a finite subgroup H. We concentrate on the case where M is compact and/or non-orientable. Interesting new features arise which have no analog on the plane. The consequences for the quantum statistics of vortices are discussed, particularly when H is non-abelian.
A phosphatase from chloroplast stroma of Nicotiana tabacum hydrolyses 2′-carboxyarabinitol 1 -phosphate, the natural inhibitor of Rubisco to 2′-carboxyarabinitol

An enzyme has been identified in the stroma of tobacco chloroplasts that degrades the natural inhibitor of Rubisco, 2′-carboxyarabinitol 1-phosphate (2CA1P). The products of the catalysis, determined by HPLC and phosphate analysis are 2′-carboxyarabinitol and inorganic phosphate indicating that the enzyme is a phosphatase. The only other phosphate esters found to be degraded by the enzyme were the branched-chain carboxylic sugar bisphosphates, 2′-carboxyarabinitol and ribitol 1,5-bisphosphates that were converted to the corresponding 5-monophosphates. Other intermediary metabolites of the photosynthetic cycle were essentially unaffected by the phosphatase. The kinetic parameters of the enzyme are consistent with those required to relieve the inhibition of rubisco in vivo.
Simple repeat replacements support similar functions of distinct repeats in inter-species mRNA homologs

Simple repeats are ubiquitous in metazoan genomes, but function has been elusive. We reported that distinct, short tandem repeats (STRs) were coupled with rigorous polarity and register, suggesting order in simple repeat usage. Several STRs that lacked internal, canonical base pairs were associated with mRNAs encoding membrane functions and transcription factors. We hypothesized that diverse, simple repeats, such as (AC)n, (GU)n, (AG)n, (CU)n and (CUUU)n, had similar functions. The hypothesis predicts that closely related mRNAs would sometimes exhibit STR replacements. Comparing aquaporin 3 mRNAs, in rodents and humans, (GU)20 replaced (AG)29. Comparing biglycan mRNAs, (GU)25 replaced (CA)12. Comparing immunoglobulin superfamily member 9 mRNAs, the STR-couple, (CU)17(GU)9 replaced the STR-couple, (GU)19(GC)4. Comparing tumor necrosis factor receptor-21 mRNAs, (GU)24 replaced (CUUU)16. In a collection of 52 rodent–H. sapiens homologous mRNAs that had STRs, six (11.5%) STR–STR replacements occurred, significantly more than expected based on an STR frequency of 0.13% in all reported UTRs (p<0.001). Database studies and the observation of STR replacements among transcript homologs independently support the hypothesis that diverse repeat sequences, such as (AG)n, (AC)n, (GU)n, (CU)n and (CUUU)n, have similar usage that is consistent with analogous functions.