cssi/SciSciGPT-SciSciNet huggingface dataset:
The Perishability of Online Grocers

In this article we explore the profitability of different operations models used by online grocers and develop a linear demand model in a competitive setting to better understand the trade-offs made by two competing online grocers in choices for distribution strategy (leverage or direct) and product focus (perishable or nonperishable). We find that the results derived in the duopoly setting are different from those in a monopolistic setting. Specifically, we determine that there is a threshold value for the secondary competitive effects in the demand function that determines how the prices and profitability of an online grocer will be affected by the supply chain length of its competitor. There is also a threshold value for the ratio of supply chain lengths of the two competitors that determines whether product perishability increases or decreases profits. We demonstrate that the existence of this threshold is robust when considering capacity constraints. Further, we show, assuming that supply chain length can be optimized, how the relative size of the infrastructure change cost (when compared with that of the competitor) coupled with the perishability of the product determines the profitability of an investment leading to a shorter supply chain.
Autoradiographic localization of hormone-concentrating cells in the brain of an amphibian, Xenopus laevis. I. Testosterone

Autoradiographic techniques for light microscopic examination of sex steroid retention were applied to the brains of male and female Xenopus laevis, an anuran amphibian, after 3H-estradiol administration. Estrogen was concentrated by cells in three telencephalic areas (the ventral striatum, the ventral-lateral septum and the amygdala), the anterior preoptic area, the ventral thalamus, the ventral infundibular nucleus, and in the torus semicircularis. The anterior preoptic area and the ventral infundibular nucleus contained the greatest number of labelled cells. The topography of estrogen-concentrating cells was the same in male and female brains. This fact and comparisons of 3H-estradiol with 3H-testosterone retention in Xenopus suggest that the sex steroid itself, and not the genetic sex of Xenopus determines the pattern of uptake by cells in the brain. The distribution of hormone-concentrating cells in Xenopus has many similarities to that found in birds and mammals. Preoptic, hypothalamic (tuberal), limbic forebrain and specific mesencephalic sites in all these forms contain labelled cells following radioactive sex steroid administration. Findings in Xenopus add to the argument for a phylogenetically stable system of hormone-concentrating nerve cells in limbic, hypothalamic and mesencephalic structures.
Recognizing the Threat Posed by an Incestuous Parent to the Victim's Siblings: Part I-- Appraising the Risk.

Despite unmistakable evidence that incest offenders rarely stop with one child, courts routinely fail to protect an incest victim's siblings. Many courts simple deny that a parent's sex act with one child signals risk to others. Nevertheless, even those courts that acknowledge a sibling's risk reach wildly different results when confronting similar cases. Courts are split over whether a parent who molests his stepchild is equally likely to victimize biological offspring or whether a father who violates a daughter will also victimize sons. There is a substantial body of research about incest that can aid courts to better gauge a sibling's risk. Because the first act of incest creates a corresponding risk to some—but not necessarily all—children in the family, Part I of this 2 part series argues in favor of a presumption of risk that offenders may rebut. Part II examines whether a sibling's gender, genetic ties to the offender, or the offender's treatment mitigate the threat and, consequently, should serve as a basis for rebutting the presumption. Ultimately, this article concludes that the law can safeguard children only if guided by substantial evidence of how abusive families function.
Lifetimes of alkali-metal—atom Rydberg states

We report a comprehensive set of calculations of the lifetimes of Rydberg states in alkali-metal atoms, using realistic potentials to represent the atomic core. The effects due to core polarizability, spin-orbit interaction, and blackbody radiation are explicitly included. A complete cross reference listing of all available experimental lifetimes is also attempted. The results compare well with experiment for all principal quantum numbers $n$ examined and should provide guidance for future experimental investigations. The relation of the present approach to other works is discussed.
Predictors of risk for adolescent childbearing.

The purpose of this research was to develop a predictive model that identifies young women at risk for adolescent motherhood. A stratified sample of 357 adolescents was drawn from public health units and public schools in six randomly selected counties in North Central Florida. Data were collected regarding the environmental context (social and family), individual perceptions of self and trajectory, and adolescent motherhood status. A stepwise logistic regression was used to investigate the combined effects of these variables for identification of risk for adolescent motherhood. Using the combination of these variables, practitioners can identify adolescents at highest risk for early motherhood (97.66%) and those with the least risk of adolescent motherhood (approximately 1%).
Botanical aspects of oregano

The condiment name “oregano” should be understood to refer, not to any one species but to a particular spice flavor, furnished by plants of several genera in different parts of the world. About one-half of the amount used in the United States comes chiefly from Mexico as dried leaves and flowers of Lippia graveolens; the rest from several species of Origanum in several European countries.
Microscopic nuclear structure on a parallel platform

Abstract Numerical techniques, used to solve a system of stiff nonlinear partial differential equations in a Hartree-Fock mean field description of the structure of the nucleus, are described in detail. A full three-dimensional discrete representation is obtained using a collocation basis-spline spatial lattice, which provides a superior method as compared to traditional approaches. The set of Hartree-Fock equations reduce, in this case, to various matrix vector multiplications and other elementary operations. Parallelization is achieved by mapping the state vectors onto the nodes, using the Intel Paragon and iPSC/860. Procedures used to perform global operations and broadcasts, and a discussion on increasing the vectorization efficiency are presented. Special attention is given to reduce the communication overhead. An algorithm to pipeline the message passing procedures within the Gram-Schmidt orthogonalization routine is discussed in detail.
Structure of friedel-crafts crosslinked polystyrene and sulfonated resins thereof

A new method of crosslinking of polystyrene using difunctional chloromethylated crosslinking agents is reported. The solution crosslinking took place in dichloroethane with SnCl4 as a catalyst at 80°C and with molar ratios of polystyrene to crosslinking agent ranging from 1∶2 to 12∶1. The crosslinked networks prepared by this method had thermal transitions considerably affected by the degree of crosslinking. Ion-exchange resins were prepared by sulfonation of these networks. Water swelling ratios as high as 16.2 were measured leading to indications about the physical structure of these networks.
Discrete Radon transforms and applications to ergodic theory

We prove Lp boundedness of certain non-translation-invariant discrete maximal Radon transforms and discrete singular Radon transforms. We also prove maximal, pointwise, and Lp ergodic theorems for certain families of non-commuting operators.
Implementation of multiple-instance learning in drug activity prediction

In the context of drug discovery and development, much effort has been exerted to determine which conformers of a given molecule are responsible for the observed biological activity. In this work we aimed to predict bioactive conformers using a variant of supervised learning, named multiple-instance learning. A single molecule, treated as a bag of conformers, is biologically active if and only if at least one of its conformers, treated as an instance, is responsible for the observed bioactivity; and a molecule is inactive if none of its conformers is responsible for the observed bioactivity. The implementation requires instance-based embedding, and joint feature selection and classification. The goal of the present project is to implement multiple-instance learning in drug activity prediction, and subsequently to identify the bioactive conformers for each molecule. We encoded the 3-dimensional structures using pharmacophore fingerprints which are binary strings, and accomplished instance-based embedding using calculated dissimilarity distances. Four dissimilarity measures were employed and their performances were compared. 1-norm SVM was used for joint feature selection and classification. The approach was applied to four data sets, and the best proposed model for each data set was determined by using the dissimilarity measure yielding the smallest number of selected features. The predictive abilities of the proposed approach were compared with three classical predictive models without instance-based embedding. The proposed approach produced the best predictive models for one data set and second best predictive models for the rest of the data sets, based on the external validations. To validate the ability of the proposed approach to find bioactive conformers, 12 small molecules with co-crystallized structures were seeded in one data set. 10 out of 12 co-crystallized structures were indeed identified as significant conformers using the proposed approach. The proposed approach was proven not to suffer from overfitting and to be highly competitive with classical predictive models, so it is very powerful for drug activity prediction. The approach was also validated as a useful method for pursuit of bioactive conformers.
Two-State Feedback Loop Adaptive Arrays for Pulsed Interference Signals

A two-state feedback loop is presented which increases the effectiveness of an adaptive array in the presence of pulsed interference signals. In the case of the two-state feedback loop, one state permits the maximum adpative response, consistent with the loop stability, and is activated in the presence of an interfering pulse. During the other state, which is activated when the interfering pulse is off, the weights are frozen at the values reached at the end of the last interfering pulse and are maintained until the next disturbance occurs. It is shown that an adaptive array with the proposed two-state loops steers permanent minima in the direction of the interfering signals, irrespective of their duty cycle. The performance of a communication system protected by such an adaptive array improves significantly over one protected by a conventional adaptive array.
Feasibility Study of Ion-Cut InP Photoconductor Devices on Glass Substrates

Photoconductive devices, prefabricated on semi-insulating InP, were integrated on glass substrates using hydrogen-induced layer transfer (ion-cut) combined with adhesive bonding. The prefabricated photodetectors were implanted through by hydrogen ions and transferred twice to achieve device-up configuration. The transferred devices exhibited both higher photocurrent and dark current when compared with bulk devices. Transient response measurement showed a long-lived tail that persisted after the initial "fast" response, indicative of trap-mediated transport due to the implant-related localized states. Our study showed that the ion-cutting layer transfer process yielded functional photodetectors. The residual defects remain a challenging issue for the ion-cut process.
Monosynaptic projections from the nucleus retroambiguus region to laryngeal motoneurons in the rhesus monkey.

Abstract Vocalization and straining-related activities require the activation of laryngeal muscles. The control of laryngeal muscles during these activities is thought to be mediated by a pathway from the periaqueductal gray via premotor neurons in the nucleus retroambiguus to laryngeal motoneurons in the nucleus ambiguus. However, direct contacts between the nucleus retroambiguus and laryngeal motoneurons have never been demonstrated anatomically. Moreover, data in primates about the nucleus retroambiguus–nucleus ambiguus pathway are lacking. Therefore, the present study examines the projection from the nucleus retroambiguus region to laryngeal motoneurons in the rhesus monkey at the light and electron microscopic levels. Injections with wheat germ agglutinin–horseradish peroxidase were made into the nucleus retroambiguus in five rhesus monkeys to anterogradely label fibers in the nucleus ambiguus. In two of these animals, the cricothyroid muscle was injected with cholera toxin subunit b to identify the motoneurons that supply it. The results show that the nucleus retroambiguus region most densely projects to the compact formation of the nucleus ambiguus, whereas cricothyroid motoneurons, which surround the compact formation, receive a moderate projection. The projections are bilateral, with a contralateral predominance. Ultrastructurally, anterogradely labeled terminal profiles from the nucleus retroambiguus contact cholera toxin subunit b-labeled dendrites of cricothyroid motoneurons. The terminal profiles contain primarily spherical vesicles and form asymmetrical contacts with cricothyroid motoneurons. This study demonstrates that the nucleus retroambiguus region projects to the nucleus ambiguus in the primate. Some of these projections include monosynaptic connections to laryngeal motoneurons. This pathway is important for the control of the vocal folds during vocalization and straining-related activities.
Estimating vignetting function from a single image for image authentication

Vignetting is the phenomenon of reduced brightness in an image at the peripheral region compared to the central region. As patterns of vignetting are characteristics of lens models, they can be used to authenticate digital images for forensic analysis. In this paper, we describe a new method for model based single image vignetting estimation and correction. We use the statistical properties of natural images in the discrete derivative domains and formulate the vignetting estimation problem as a maximum likelihood estimation. We further provide a simple and efficient procedure for better initialization of the numerical optimization. Empirical evaluations of the proposed method using synthesized and real vignetted images show significant gain in both performance and running efficiency in correcting vignetting from digital images, and the estimated vignetting functions are shown to be effective in classifying different lens models.
A symbolic computation method of analytic solution of the mixed Direchlet-Neumann-Robin problem for LaPlace's equation

The authors show how to use symbolic computing methods to obtain an analytic representation of the solution ofLaplace's equation (in R2 or R3) satisfying boundary conditions of a very general type, viz., involving conditions of Dirichlet, Neumann and Robin's type on disjoint subsets of the boundary of the solution domain.
Probes for narcotic receptor mediated phenomena. Part 31: Synthesis of rac-(3R,6aS,11aS)-2-methyl-1,3,4,5,6,11a-hexahydro-2H-3,6a-methanobenzofuro[2,3-c]azocine-10-ol, and azocine-8-ol, the ortho-c and the para-c oxide-bridged phenylmorphan isomers

Abstract Two of the 12 possible oxide-bridged phenylmorphans, were synthesized, rac-(3R,6aS,11aS)-2-methyl-1,3,4,5,6,11a-hexahydro-2H-3,6a-methanobenzofuro[2,3-c]azocine-10-ol ( 7 ) (the ortho-c compound), and rac-(3R,6aS,11aS)-2-methyl-1,3,4,5,6,11a-hexahydro-2H-3,6a-methanobenzofuro[2,3-c]azocine-8-ol ( 8 ) (the para-c compound). Single-crystal X-ray diffraction studies indicated that the dihedral angle between the least squares planes through the phenyl ring and the atoms C1, C11a, C12, and C3 in the piperidine ring in both 7 ·CHCl3 and 8 ·HBr was 6.9°. The C12–C6a–C6b–C10a torsion angle was found to be 139.3° for both compounds. The angular relationship between the phenolic ring and the piperidine ring in phenylmorphans that interact with specific opioid receptors as agonists or antagonists is of considerable theoretical interest.
Effects of viscosity on ship waves

The effect of viscosity on the trailing-wave system well downstream of a uniformly moving surface disturbance is determined. Solutions are obtained by series expansions in inverse powers of a Reynolds number and coefficients in the viscous exponential decay-factor found. It is seen that the diverging wave pattern is much more heavily damped than the transverse waves.
Staff‐inmate bargaining tactics in long‐term treatment institutions

The field notes of four studies of long-term treatment institutions are examined for patterns of staff-inmate bargaining. The main focus is on the conditions which enhance the bargaining power of staff and of inmates in relation to each other. A list of such conditions with examples is provided.
New markets, old struggles: Large and small farmers in the export agriculture of coastal Peru

Although the output of high-value crops in Peru has increased during the era of ‘globalization’, producers still tend to contextualize this development in relation to the 1969 agrarian reform. Considered here is how large and small farmers in the Canete region perceive the changes that have occurred in agriculture since a generation ago, with particular reference to market competition and the implications of the new economic conditions for environmental sustainability. Despite the fact that farmers located at each end of the rural hierarchy experience the economic impact of globalization differently, small cultivators exporting their produce to the international market being particularly vulnerable to its laissez faire regime, they nevertheless share a common belief in the importance of agriculture for the well-being of the nation. The latter, it is suggested, is a discourse that reproduces much of the ideology associated historically with the agrarian and foundation myths.
Immunogenicity of two recombinant hepatitis B vaccines in older individuals

Abstract purpose: Currently available hepatitis B vaccines are recombinant, yeast-derived preparations given in 10-μg or 20-μg doses. The optimum dose remains controversial. We sought to assess the relative immunogenicity of two hepatitis B vaccines, given in different doses, in older individuals. patients and methods: In a multicenter, double-blind, randomized clinical trial, a total of 460 healthy subjects between 39 and 70 years of age were screened and immunized with either Engerix-B 20 μg or Recombivax HB 10 μg in standard, intramuscular, 3-dose regimens. Of these, 397 subjects were eligible to continue vaccination. Immunogenicity was measured by determination of antibody to hepatitis B surface antigen (anti-HBs). Seroconversion and seroprotection rates, and geometric mean titers of anti-HBs were calculated at 1, 3, 6, and 8 months after the initial dose of vaccine. results: Seroprotection rates for subjects receiving the 20-μg dose of vaccine were slightly, but not significantly, greater than for subjects receiving the 10-μg dose, at each time point. However, at 3 months, males receiving the higher dose had significantly higher seroprotection rates than males receiving the lower dose: 63% versus 37% (p conclusions: Immunization with the 20-μg dose of recombinant hepatitis B virus vaccine appeared to result in more rapid development of seroprotective anti-HBs titers in older men and in higher titers of anti-HBs at the completion of vaccination when compared to the 10-μg dose. The latter data suggest that the 20-μg dose may result in a longer duration of seroprotective anti-HBs titers.
The Use of a Fish‐Eye Lens to Study Nest Placement in Franklin's Gulls

A Franklin's Gull colony in northwestern Minnesota was sampled to determine if there is a correlation between closeness of adjacent nests and visibility. A method of vegetation analysis using a fish—eye lens in presented. Franklin's Gulls select nest sites which are least visible to neighboring gulls. See full-text article at JSTOR
A classic examination of fluvial processes and forest patterns: Victor Ernest Shelford’s (1954) ‘Some Lower Mississippi Valley Flood Plain Communities: Their Age and Elevation’. Ecology 35(2): 126–142.1

The study of the interaction between fluvial processes and forest community patterns owes elements of its origins to the research of Shelford (1954) on the Mississippi River valley. Shelford (1954) is a classic for many reasons; three highlighted here are its role of establishing a methodology for applying historical resources for long-term research studies, its influence on developing conceptual models of forest succession relative to multiple controlling factors, and its recognition of the rapid and extensive impact of human activities on altering natural land-cover patterns and the important role of analog forests for management and conservation. References to Shelford (1954) within the literature have increased every year since its publication and I believe its presence among varied disciplines will continue.
Structure of Poly(ethylene oxide) Surfactant Polymers at Air−Water and Solid−Water Interfaces

The surface active properties of novel poly(ethylene oxide) (PEO) containing surfactant polymers were investigated at the air−water and graphite−water interfaces. The surfactant polymers are combli...
Analysis of Mopc‐315 Plasmacytoma By Elutriation and Flow Cytometry

Intravenously transplanted murine plasmacytoma MOPC-315 cells were separated from normal spleen cells from a tumour-bearing mouse by elutriation and characterized according to morphology, immunologic properties and clonogenicity. Morphologically, both lymphocytoid and plasmacytoid cells were separable by elutriation. Flow cytometry correlated DNA content and intracytoplasmic IgA content and demonstrated two distinct populations, both in cell cycle, but with markedly different cellular IgA levels. Density gradient separation characterized the lower-density cells with lower IgA content and higher clonogenicity. From these studies a model of cellular differentiation is proposed.
Nearly degenerate time-resolved Faraday rotation in an interacting exciton system

We report experimental studies of nearly degenerate time-resolved Faraday rotation (TRFR) of electron spin precession in an interacting exciton system. We show that many-body interactions between excitons strongly modify the TRFR response through the coupling of the spin coherence to two-exciton states. The striking difference between TRFR and transient differential absorption (DA) further reveals that exciton-exciton interactions play crucial but qualitatively different roles in TRFR and DA.
Some conditions under which tri-quotient or compact-covering maps are inductively perfect

Abstract We solve two problems posed by E. Michael (1981) concerning whether certain compact-covering maps are inductively perfect, we generalize a theorem of A. Ostrovsky on a condition under which tri-quotient maps are inductively perfect and we present an example which answers a more recent question of Michael in the same general area.
Affection as a separate dimension of meaningfulness

Abstract The meaningfulness of affectively significant (liked) materials has been shown to be separate from traditional explanations of meaningfulness, such as familiarity and rehearsal, in the verbal learning laboratory. The present investigation studied affective meaningfulness in the learning of course materials. Before the course began, students rated summaries of the study units of their course for affection. As predicted, subjects obtained higher examination grades on liked topics than on disliked topics, independently of perhaps the most prominent “rehearsal” explanation, amount of study on the various units. Also as expected, poor students showed a greater reliance on affective meaningfulness in their learning than did good students. Greater awareness of the role of affection in learning is recommended. Present findings suggest that considering this dimension of meaningfulness to be merely a by-product of familiarity or rehearsal may be the most detrimental to the students with the most learning difficulty.
Duration of intubation attempts during neonatal resuscitation.

Abstract Objective Since the American Academy of Pediatrics Neonatal Resuscitation Program recommends that intubation should be completed in approximately 20 seconds, we measured the duration of neonatal intubation attempts by different operators, using video recordings of neonatal resuscitations. Study design We used an ongoing quality improvement program to measure the duration of intubation attempts. Results The mean duration for the 50 successful intubations, including 6 for meconium, was 27.3 seconds compared with 29.8 seconds for unsuccessful attempts (not significant). Fifteen infants were successfully intubated on each of the first and second attempts, 10 on the third attempt, and 10 required more than 3 attempts. The mean duration of successful intubation was 31.9 seconds for PL-1's, 27.5 seconds for PL-2/3's, and 23.6 seconds for fellows. Overall intubations were more successful for a duration of 30 seconds or less compared with 20 seconds or less (72% vs 38%; χ 2 =10.3, P =.001). No infant decompensated between 20 and 30 seconds. Ten successful and 12 failed attempts took longer than 40 seconds. Conclusions We recommend that a duration of 30 seconds is a reasonable guideline for neonatal intubation during resuscitation.
Perception of HIV and Safer Sexual Behaviors among Lesbians

There is little data on female-to-female transmission of HIV. Some women who have sex with women (WSW) have other high-risk behaviors that could lead to HIV infection. The belief that WSW are at no risk maylead to unsafe sexual practices. In this study, a convenience sample of 78 women was surveyed in order to explore the perception of HIV risk among lesbians, their sexual behaviors, and their sources of information about safer sex. Fifty-three percent reported theywer e at low risk for contracting HIV. Women reported knowledge of barrier methods (89% to 99%) and no sex during menstruation (92%). However, 35% to 40% reported no knowledge of less common safer sex practices. Women reported their source of knowledge as media (36%), workshops (22%), and friends (12%). Eighty-five percent stated that their health care provider knew theywer e lesbian, but only 15% reported receiving safer sex education. Nurses and nurse practitioners are aptlypoised to provide critical HIV education and health care for this population.
Minireview: Cellular Redox State Regulates Hydroxysteroid Dehydrogenase Activity and Intracellular Hormone Potency

Hydroxysteroid dehydrogenases (HSDs) interconvert potent and relatively inactive forms of individual steroid hormones using nicotinamide cofactors NADPH/NADP(+) and NADH/NAD(+) [nicotinamide adenine dinucleotide (phosphate), reduced/oxidized forms]. Although reactions with purified enzymes in vitro may be driven in either direction depending on the assay conditions, HSD enzymes appear to function in one direction or the other in intact cells. At least for some of these enzymes, however, the apparent unidirectional metabolism actually reflects bidirectional catalysis that reaches a pseudoequilibrium state with a strong directional preference. This directional preference, in turn, derives from intracellular concentration gradients for the nicotinamide cofactors and the relative affinities of each HSD for these cofactors. Because the concentrations of free cofactor exceed those of steroids by many orders of magnitude, the activities of these enzymes are predominantly driven by cofactor abundance, which is linked to intermediary metabolism. Consequently, the amount of active steroids in cells containing HSDs may be modulated by cofactor abundance and, hence, intracellular redox state. We will review the evidence linking cofactor handling and HSD activity, speculate on additional ways that intracellular metabolism can alter HSD activity and, thus, hormone potency, and discuss fruitful avenues of further investigation.
Fabrication and Performance of Diffractive Optics for Quantum Well Infrared Photodetectors

Diffractive optical elements (microlenses) for quantum well infrared photodetectors (QWIPs) were fabricated by two techniques: (1) standard lithography of a binary optical structure and (2) PMMA pattern transfer for an analog diffractive optic structure. The binary lenses were fabricated by sequential contact lithography and etching using two binary masks. The analog diffractive lenses were fabricated in PMMA by direct-write e-beam lithography followed by acetone development. The resulting PMMA surface relief profile was transferred into the GaAs by dry etching. Both types of lenses were etching into GaAs using an electron cyclotron resonance (ECR) microwave plasma etching system. Although the lenses were fabricated accurately, the performance of the QWIPs was not improved as much as expected due to the angle-of-incidence sensitivity of the QWIP light-coupling grating. The lenses would have likely improved the performance of detectors capable of absorbing normally incident light.
Giant proteins that move DNA: bullies of the genomic playground

As genetic material DNA is wonderful, but as a macromolecule it is unruly, voluminous and fragile. Without the action of DNA replicases, topoisomerases, helicases, translocases and recombinases, the genome would collapse into a topologically entangled random coil that would be useless to the cell. We discuss the organization, movement and energetics of these proteins that are crucial to the preservation of a molecule that has such beautiful biological but challenging physical properties.
Insights into Methyltransferase Specificity and Bioactivity of Derivatives of the Antibiotic Plantazolicin

Peptide antibiotics represent a class of conformationally constrained natural products of growing pharmaceutical interest. Plantazolicin (PZN) is a linear, polyheterocyclic natural product with highly selective and potent activity against the anthrax-causing bacterium, Bacillus anthracis. The bioactivity of PZN is contingent on dimethylation of its N-terminal Arg residue by an S-adenosylmethionine-dependent methyltransferase. Here, we explore the substrate tolerances of two homologous PZN methyltransferases by carrying out kinetic analyses of the enzymes against a synthetic panel of truncated PZN analogs containing the N-terminal Arg residue. X-ray cocrystal structures of the PZN methyltransferases with each of these heterocycle-containing substrates provide a rationale for understanding the strict substrate specificity of these enzymes. Kinetic studies of structure-guided, site-specific variants allowed for the assignment of residues governing catalysis and substrate scope. Microbiological testing further revealed that upon dimethylation of the N-terminal Arg, a pentaheterocyclized PZN analog retained potent anti-B. anthracis activity, nearly equal to that of full-length PZN. These studies may be useful in the biosynthetic engineering of natural product analogs with different bioactivity profiles, as demonstrated by our identification of a truncated plantazolicin derivative that is active against methicillin-resistant Staphylococcus aureus (MRSA).
Information Processing In Single Yeast Cells: Homogeneous Signal Transduction Result In Heterogeneous Gene Expression

How cells sense their environment using signal transduction pathways and respond to environmental changes by regulating gene expression is a key problem in systems biology. The mitogen-activated protein kinase (MAPK) pathways, which are evolutionarily conserved from yeast to mammals, provide an excellent model to study how signal transduction is coupled to gene expression. Our research focus on the high-osmolarity glycerol (HOG) MAPK pathway in single, Saccharomyces cerevisiae yeast cells. During the last few decades, the components and regulatory network of this pathway have been elucidated via genetic and biochemical assays performed on large populations of yeast cells. However, surprisingly little is known about the detailed coupling dynamics of signal transduction and gene expression in individual cells. After osmotic shock, homogeneous Hog1 kinase dynamics were measured in all cells. In the subsequent gene expression of STL1, a gene that encodes for a glycerol proton symporter of the plasma membrane, we observed that one subpopulation of cells exhibits no gene expression at all (OFF-population), whereas another subpopulation of cells show gene expression over a wide range of expression levels (ON-population). Further, the ratio of the two subpopulations of cells remained constant despite changes in osmolyte concentration from 0.3 M to 0.6 M NaCl. To identify the origin of the bi-modality in gene expression, we over expressed specific transcription factors that regulate STL1 - gene expression. After over expression of one specific transcription factor, we observed a mono modal gene expression distribution for STL1. Furthermore, single cell time-lapse experiments, indicate that switching between gene expression levels after subsequent osmotic shocks was random and uncorrelated. These results indicate, that at least one transcription factor is responsible for the bi-modality and stochasticity in gene expression.
An Impedance Transformation Method for Finding the Load Impedance of a Two-Port Network

An unknown load impedance terminating a lossy two-port junction can be calculated if the input impedance and junction parameters are known. It is to be shown that there exists a linear relationship, dependent upon two calibration constants, between the input reflection coefficient and a modified reflection coefficient of the load. Applying the linear transformation to the junction input impedance permits evaluation of the unknown load impedance. Calibration is accomplished by terminating the transmission line in at least three different reactance and measuring the corresponding input reflection coefficients. These data plot into the usual circular configuration on a Smith chart from which the necessary calibration data is obtained. When several load reactances are used, the calibration accuracy can be considerably increased, since the averaging advantage of plotting a mean straight line is utilized. Furthermore, once the junction has been calibrated, its equivalent T-network impedances and scattering coefficients may be found.
Determination of the Strain Source in Mo/Ni Multilayers

Structural characterization and strain measurements were conducted on Mo/Ni multilayers, with bilayer periods between 10 A and 200 A, utilizing symmetric, asymmetrin, and grazing incidence x-ray diffraction techniques. The structural difference between the 15 A and 20 A modulation wavelength samples, evident in the symmetric high angle diffraction spectra, is attributed to the absence of crystalline registry in the early stages of sputter deposition, yielding crystalline order only when the bilayer deposition thickness exceeded 15 A. The dominant mechanism for the observed modulation wavelength dependent strain behavior, both in the growth direction and in the plane of the film, is consistent with a coherency strain model. The orientation relationship predicted for the Mo/Ni system, based on their atomic radii ratio is the Nishiyama-Wasserman relationship, (110)BCC//(111 )FCC and [001]BCC//[101]FCC. This relationship would provide the source for the observed coheency strain.
Mirror self-recognition in a gorilla (gorilla gorilla gorilla)

Chimpanzees (Pan troglodytes) and orangutans (Pongo pygmaeus) pass the mirror self-recognition test (MSR) with limited mirror training or exposure, but the evidence suggesting that gorillas do so is unclear. This project examined a male gorilla (G. gorilla gorilla) named Otto in a modified mark test. During the test trials, Otto was marked, without anesthesia, with odorless and tasteless dye by his trainer. A video-camera recorded his behavior, which was later scored by observers who did not know whether or not the trials were in front of the mirror. The results showed that Otto touched the marked area more when he was in front of the mirror than in other conditions. These results are interpreted in terms of current theory of MSR.
Behavioral and endocrine dynamics associated with infanticide in a black and white colobus monkey (Colobus guereza)

Infanticide has been observed in several colobines, but only one infanticide has previously been documented for black and white colobus monkeys (Colobus guereza). This report describes an infanticide observed in Kibale National Park, Uganda, in the summer of 2001. An adult male from a neighboring group attacked and killed a young infant whose mother subsequently remained in her own group and was observed mating 10 days later. She engaged in two mating periods of several days each, separated by approximately 1 month, during which she copulated frequently with the dominant male within her group. Urinary estrogen (EC) and progesterone metabolite (PdG) excretion patterns demonstrated that the female resumed ovarian cycling soon after the infanticide. Because the infanticidal male did not attempt to mate with the victim's mother, his actions were not consistent with the predictions of the sexual-selection hypothesis. We speculate that infanticide associated with intergroup aggression may help secure access to high-quality resources for the infanticidal male's group.
Shapemaker: A game-based introduction to programming

As emphasis on Science, Technology, Engineering, and Math (STEM) initiatives increase, students are at a fragile point in their education. It is imperative that students learn core skills like computer programming and procedural logic necessary to living in today's increasingly digital society. Our new game Shapemaker solves these problems in game-based learning that incorporates an engaging augmented reality interface. ShapeMaker utilizes a table-based tactile interface that bridges physical actions with digital results, allowing players to learn basic concepts in programming by playing a card game. Shapemaker aims to transform the process of introducing new students to the world of programming and create a new, wider demographic of computer programmers. This article is a preliminary study of Shapemaker, documenting its concept, current design, and directions for development.
Determining source contribution in integration systems

Owners of sources registered in an information integration system, which provides answers to a (potentially evolving) set of client queries, need to know their contribution to the query results. We study the problem of deciding, given a client query Q and a source registration R, whether R is (i) "self-sufficient" (can contribute to the result of Q even if it is the only source in the system) or (ii) "now complementary" (can contribute, but only in cooperation with other specific existing sources), or (iii)"later complementary" (can contribute if in the future appropriate new sources join the system). We consider open-world integration systems in which registrations are expressed using source-to-target constraints, and queries are answered under "certain answer" semantics.
Pheochromocytoma and adrenal cortical adenoma; report of a case with both tumors and discussion of their relation.

INTRODUCTION THE independent investigations of Vogt (1, 2) and Long (3, 4) from 1944 to 1947 firmly established in laboratory animals a secretory relationship between the adrenal medulla and cortex. Epinephrine released by splanchnic stimulation or injected intravenously is followed by increased cortical secretion. This action of epinephrine has been demonstrated by Long to take place via the anterior pituitary. The epinephrine stimulates the anterior pituitary to release corticotropic hormone (ACTH) which, in turn, stimulates the adrenal cortex. Clinical confirmation of these laboratory studies has been obtained by Thorn et al. (5), who have demonstrated that epinephrine causes a depression in circulating eosinophils comparable to that following administration of ACTH (6). In view of this physiologic relationship between the medulla and cortex of the adrenal gland, now apparently well established, it is curious that patients with a hypersecreting tumor of the adrenal medulla, i.e., a pheochromocytoma, do...
Distributions of Z-DNA and nuclear factor I in human chromosome 22: a model for coupled transcriptional regulation

An analysis of the human chromosome 22 genomic sequence shows that both Z-DNA forming regions (ZDRs) and promoter sites for nuclear factor-I (NFI) are correlated with the locations of known and predicted genes across the chromosome and accumulate around the transcriptional start sites of the known genes. Thus, the occurrence of Z-DNA across human genomic sequences mirrors that of a known eukaryotic transcription factor. In addition, 43 of the 383 fully annotated chromosomal genes have ZDRs within 2 nucleosomes upstream of strong NFIs. This suggests a distinct class of human genes that may potentially be transcriptionally regulated by a mechanism that couples Z-DNA with NFI activation, similar to the mechanism previously elucidated for the human colony stimulation factor-I promoter [Liu et al. (2001) Cell, 106, 309–318]. The results from this study will facilitate the design of experimental studies to test the generality of this mechanism for other genes in the cell.
How Listeners Compensate for Disfluencies in Spontaneous Speech

Listeners often encounter disfluencies (like uhs and repairs) in spontaneous speech. How is comprehension affected? In four experiments, listeners followed fluent and disfluent instructions to select an object on a graphical display. Disfluent instructions included mid-word interruptions (Move to the yel- purple square), mid-word interruptions with fillers (Move to the yel- uh, purple square), and between-word interruptions (Move to the yellow- purple square). Relative to the target color word, listeners selected the target object more quickly, and no less accurately, after hearing mid-word interruptions with fillers than after hearing comparable fluent utterances as well as utterances that replaced disfluencies with pauses of equal length. Hearing less misleading information before the interruption site led listeners to make fewer errors, and fillers allowed for more time after the interruption for listeners to cancel misleading information. The information available in disfluencies can help listeners compensate for disruptions and delays in spontaneous utterances.
A clumped-foliage canopy radiative transfer model for a Global Dynamic Terrestrial Ecosystem Model II: Comparison to measurements.

Abstract In a previous paper, we developed an analytical clumped two-stream model (ACTS) of canopy radiative transfer from an analytical geometric-optical and radiative transfer (GORT) scheme ( Ni-Meister et al., 2010 ). The ACTS model accounts for clumping of foliage and the influence of trunks in vegetation canopies for modeling of photosynthesis, radiative fluxes and surface albedo in dynamic global vegetation models (DGVMs), and particularly for the Ent Dynamic Global Terrestrial Ecosystem Model (DGTEM). This study evaluates the gap probability and transmittance estimates from the ACTS model by comparing the modeled results with ground-based data, as well as with the original full GORT model and a layered Beer's law scheme. The ground data used in this study include vertical profile measurements of incident photosynthetically active radiation (PAR) in (1) mixed deciduous forests in Morgan-Monroe State Forest, IN, USA, (2) coniferous forests in central Canada, (3) mixed deciduous forests in Harvard Forest, MA, and (4) ground lidar measurements of the canopy gap fraction in woodland in Australia. The model comparisons with these measurements demonstrate that the ACTS model achieves better or similar performance compared to the full GORT and the layered Beer's law schemes with regard to agreements with field measurements and computational cost. The ACTS model has excellent accuracy and flexibility to model the canopy gap probability and transmittance for various forest scenarios. Also, it has advantages relative to the currently widely used two-stream scheme through better radiation estimation for photosynthesis by accounting for the impact of both vertical and horizontal structure heterogeneity of complex vegetation on radiative transfer. Currently the ACTS is being implemented in Ent and will be further tested for how it improves surface energy balance and carbon flux estimates.
Please forget democracy and justice: Eritrean politics and the powers of humor

Parody possesses a kind of power that realist critique sometimes lacks. I explore why humor is sometimes used as a medium for addressing tragic circumstances and why parody in particular may be especially suited to communicating about dictatorship. The research presented here draws on a long-term project on Eritrean politics and on websites devoted to Eritrean politics created by Eritreans in diaspora. The core of the analysis dissects an online political parody of conditions under the regime of President Isaias Afewerki. So much of what is known and written about Eritrean history and current realities, whether by scholars, journalists, international organizations, or Eritreans online, is earnest, serious, and even heartbreaking. The uses of humor in this context seem to call for an explanation, and the analysis presented here sheds light on the mechanisms through which humor accomplishes important political work and fosters the development of new subjectivities.
Alcohol abuse and job hazards

Do hazardous working conditions encourage heavy drinking and/or does heavy drinking contribute to job-related injuries and deaths? Simultaneous equations probit and least squares models are constructed to answer these questions. Samples of employed persons are drawn from the National Health and Nutrition Examination Survey II (NHANES II; n = 8,477), and the Quality of Employment Survey (QES; n = 1,393). Heavy total alcohol use is alternatively defined as drinking any alcoholic beverage at least once a day, or frequently drinking three or more drinks at a time. In the QES, heavy use is also defined as drinking on-the-job. Heavy beer, wine, or liquor use is separately defined in the NHANES II as drinking four or more times per week. The endogenous variables reflecting job hazards include subjects' evaluations of the hazardous nature of the job and fatality rates within occupations and industries. Exogenous variables include age, gender, race, marital status, wages or family income, rural residence, Southern residence, years of schooling, union membership, percent of industry unionized, minimum legal drinking age for beer, religion variables, smoking status, and beer tax. Only one robust alcohol finding emerged: Heavy beer use was found to be strongly correlated with the fatality rates within occupations and industries. In a related finding, a disproportionately high number of smokers were found employed in dangerous jobs. Separate analyses of beer, wine, and liquor (spirits) appeared essential to explaining correlations between dangerous jobs and heavy alcohol use. Evidence for a simultaneous relationship between beer abuse and job-related deaths suggests that prior estimates of the effect of alcohol abuse on job-related accidental deaths have been exaggerated.