cssi/SciSciGPT-SciSciNet huggingface dataset:
A User's Guide to Section 230, and a Legislator's Guide to Amending It (or Not)

Section 230 of the Communications Decency Act, which immunizes online service providers from liability for user content, is key to the business models of some of the nation’s largest online platforms. For two decades, the 1996 statute was mostly unknown outside of technology law circles. This changed in recent years, as large social media companies have played an increasingly central role in American life and have thus faced unprecedented scrutiny for their decisions to allow or remove controversial user content. Section 230 has entered the national spotlight as a topic of national media coverage, congressional hearings, and presidential campaign rallies. Unfortunately, not all this attention has accurately portrayed why Congress passed Section 230 or how the statute works. The misunderstandings of the law are particularly troubling as Congress is considering dozens of proposals to amend or repeal it. This Article attempts to set the record straight and provide a “user’s guide” to the statute, along with principles for legislators to consider as they evaluate amendments to this vital law.
Relationship of fat metabolism to health and performance in dairy cattle

Rapid mobilization of adipose fat accompanied by hyperketonemia and fatty liver (FL) is extremely common in peripartum dairy cows. Previous reports indicate an inverse relationship between liver fat concentration and disease resistance. Such a relationship could be mediated through a hyperketonemic suppression of cellular immunity, altered serum lipoprotein concentrations or other effects associated with negative energy balance. Appetite reduction may be associated with fat mobilization and this could be due to FL and the direct effects of the liver on food-intake centers of the brain. Reproductive efficiency is reduced in association with FL; such an association could be due to FL-associated hypolipoproteinemia and the need for serum lipoproteins to support maximal progesterone synthesis by the ovary.
Water Flow in Saturated Soil

The flow through soil pores is limited by numerous constrictions. Therefore, flow through a complex porous medium, such as a soil, is generally described in terms of a macroscopic flow-velocity vector, which is the overall average of the microscopic velocities over the total volume considered. The Darcy's law implies where flow is unsteady (the flux changes with time) or the soil is nonuniform, the hydraulic head may not decrease linearly along the direction of flow. Where the hydraulic head gradient or the conductivity is variable over time and space, the instantaneous localized gradient, flux, and conductivity values are considered rather than the average values for the soil system as a whole. The Darcy's law, by itself, is sufficient only to describe steady flow processes. Unsteady, or transient, flow processes, in which the magnitude and possibly even the direction of the flux and potential gradient vary in time, require the inclusion of an additional law—namely, the law of conservation of matter.
Optimal Dynamic Range Searching in Non-replicating Index Structures

In this paper, we examine the complexity of multi-dimensional range searching in non-replicating index structures. Such nonreplicating structures achieve low storage costs and fast update times due to lack of multiple copies. We first obtain a lower bound for range searching in non-replicating structures. Assuming a simple tree structure model of an index, we prove that the worst-case time for a query retrieving t out of n data items is Ω((n/b)(d-1)/d + t/b), where d is the data dimensionality and b is the capacity of index nodes. We then propose a new index structure, called the O-tree, that achieves this query time in dynamic environments. Updates are supported in O(logb n) amortized time and exact match queries in O(logb n) worst-case time. This structure improves the query time of the best known non-replicating structure, the divided k-d tree, and is optimal for both queries and updates in non-replicating tree structures.
The site of auramine O binding to horse liver alcohol dehydrogenase.

Abstract In agreement with an earlier report (Conrad, R. H., Heitz, J. R., and Brand, L., Biochemistry, 9, 1540 (1970)), auramine O was found to bind to horse liver alcohol dehydrogenase at two equivalent noninteracting sites per enzyme molecule, with an intrinsic dissociation constant Kr = 1.65 x 10-5 m in 0.05 m phosphate buffer at pH 7.0 at 25°. The dye was displaced competitively from the enzyme by substrates (ethanol and 1-butanol), substrate inhibitors (decanoic acid, imidazole, and pyrazole), and by inhibitors binding to the zinc ion presumed to be at the active site (1,10-phenanthroline and 2,2-bipyridine). The dye forms ternary complexes, with comparable affinity, with the binary complexes of the enzyme with NAD+, NADH, and adenosine diphosphoribose. In all three cases, the dissociation constant of auramine O from the ternary complex is significantly lower than the dissociation constant for the enzyme-auramine O binary complex. On the basis of the noncompetitive inhibition of liver alcohol dehydrogenase by auramine O in initial rate studies, Conrad et al. suggested that the dye binding site is distinct from the coenzyme and substrate binding sites. This interpretation is incompatible with the data summarized above. The apparent noncompetitive inhibition kinetic data are shown here to be the consequence of the unique ability of the dye to form ternary complexes with the enzyme-NAD+ and enzyme-NADH binary complexes. Thus, the auramine O-alcohol dehydrogenase interaction offers an additional case to the general correlation that most dyes which bind tightly to enzymes interact at regions overlapping binding sites for the normal ligands.
Prostaglandins and cannabis--IX. Stimulation of prostaglandin E2 synthesis in human lung fibroblasts by delta 1-tetrahydrocannabinol.

Abstract Preliminary data [S. Burstein and S. A. Hunter, Biochem. Pharmac . 27 ,1275 (1978)]showed that cannabinoids at levels of 1 μM or greater elevated the concentrations of prostaglandins in cell culture models. Further study [S. Burstein and S. A. Hunter, J. clin. Pharmac. 21 , 240S (1981)]led to the suggestion that this effect was due to a stimulation of phospholipase A 2 resulting in the release of free arachidonic acid which was then partly converted into the prostaglandin(s) normally synthesized by the particular target system. The present report gives detailed data on the cannabinoid-induced synthesis of prostaglandin E 2 by the WI-38 fibroblast derived from human lung. The effect could be blocked by pretreatment with mepacrine, a phospholipase inhibitor, and aspirin, a cyclooxygenase inhibitor. These findings lend support to the hypothesis that some of the in vivo actions of the cannabinoids are due to modulations in prostaglandin synthesis at various tissue sites.
Sources of Error in the Metaphysics of Time

L'A. cherche a cerner les sources d'erreur dans la pratique de la metaphysique du temps. A cette fin, il se fonde sur les travaux de Wittgenstein dans ce domaine, et notamment sur son ouvrage Recherches Philosophiques. L'A. formule donc dans les termes suivants sa problematique : comment peut-il y avoir un usage veritable du langage factuel qui ne decrive pas quelque fait present ? Comment peut-il y avoir une verite sans faits ? Et s'il existe des faits passes, existent-ils maintenant ? Car s'ils existent, il ne sont plus vraiment passes ! L'A. pense que les methodes de Wittgenstein ont la clef de la comprehension et de la solution de ce probleme
A novel graphical technique for analysis of runtime cache behavior

A novel technique is introduced to graphically analyze the runtime behavior of block replacement algorithms used in cache controllers. The new method allows a behavioral comparison of two or more algorithms, previously impossible due to the vast amount of data involved in cache simulations. Absolute and relative comparisons are demonstrated and the application in the development of a modified LRU is shown.
Tight Lower Bounds for Multi-pass Stream Computation Via Pass Elimination

There is a natural relationship between lower bounds in the multi-pass stream model and lower bounds in multi-round communication. However, this connection is less understood than the connection between single-pass stream computation and one-way communication. In this paper, we consider data-stream problems for which reductions from natural multi-round communication problems do not yield tight bounds or do not apply. While lower bounds are known for some of these data-stream problems, many of these only apply to deterministic or comparison-based algorithms, whereas the lower bounds we present apply to any (possibly randomized) algorithms. Our results are particularly relevant to evaluating functions that are dependent on the ordering of the stream, such as the longest increasing subsequence and a variant of tree pointer jumping in which pointers are revealed according to a post-order traversal. Our approach is based on establishing "pass-elimination" type results that are analogous to the round-elimination results of Miltersen et al. [23] and Sen [29]. We demonstrate our approach by proving tight bounds for a range of data-stream problems including finding the longest increasing sequences (a problem that has recently become very popular [22,16,30,15,12] and we resolve an open question of [30]), constructing convex hulls and fixed-dimensional linear programming (generalizing results of [8] to randomized algorithms), and the "greater-than" problem (improving results of [9]). These results will also clarify one of the main messages of our work: sometimes it is necessary to prove lower bounds directly for stream computation rather than proving a lower bound for a communication problem and then constructing a reduction to a data-stream problem.
Comparison of seven liver allocation models with respect to lives saved among patients on the liver transplant waiting list

The patients with end-stage liver disease (ESLD) on the liver transplant waiting list are prioritized for transplant based on the model for end-stage liver disease (MELD) score. We developed and used an innovative approach to compare MELD to six proposed alternatives with respect to waiting list mortality. Our analysis was based on United Network for Organ Sharing data of patients with ESLD on the waiting list between January 2006 and June 2009. We compared six allocation models to MELD. Two models were based on reweighting the variables used by MELD: an "updated" MELD, and ReFit MELD. Four models also included serum sodium: MESO, MeldNa, UKELD, and ReFit MELDNa. We estimated that UKELD and the updated MELD would result in significantly fewer lives saved. There were no significant differences between the other models. Our new approach can supplement standard methods to provide insight into the relative performance of liver allocation models in reducing waiting list mortality. Our analysis suggests that UKELD and the updated MELD score would not be optimal for reducing waiting list mortality in the United States.
The 'elephant trunk' manipulator, design and implementation

Over that last several years, research in the area of hyper-redundant robots and those robots based on tentacle/trunk type manipulators has become of great interest. Though much progress has been obtained in both the areas of robot construction and robot kinematics, there has been little progress in the implementation of a kinematic model for motion on a physical robot. We review both our 'elephant trunk' robot's construction and our previously designed kinematic model. We provide experimental results verifying not only the legitimacy of our kinematic model, but also the real time implementation of the model on the physical robot.
Negative affect as a mediator of the relationship between weight-based teasing and binge eating in adolescent girls

Previous research has established a link between weight-based teasing and binge eating, though the precise mechanisms that drive this relationship remain unknown. This study examined negative affect as a mediator of the relationship between weight-based teasing and binge eating. Participants included 265 adolescent female twins (aged 10-15 years). Self-report measures assessed binge eating, weight-based teasing, and negative affect. Mediation was tested within hierarchical linear models to control for the non-independence of the twin data. Significant positive associations were observed between binge eating, teasing, and negative affect. In the regression analyses, negative affect partially mediated associations between weight-based teasing and binge eating. Results suggest that increases in negative affect are one way in which weight-based teasing leads to binge eating in girls. Future studies should examine additional mediators and assess possible clinical applications of these findings.
The compactness of first-order logic:from gödel to lindström

Though regarded today as one of the most important results in logic, the compactness theorem was largely ignored until nearly two decades after its discovery. This paper describes the vicissitudes of its evolution and transformation during the period 1930-1970, with special attention to the roles of Kurt Godel, A. I. Maltsev, Leon Henkin, Abraham Robinson, and Alfred Tarski
Numerical modeling of unsaturated flow in wastewater soil absorption systems

It is common practice in the United States to use wastewater soil absorption systems (WSAS) to treat domestic wastewater. WSAS are expected to provide efficient, long-term removal of wastewater contaminants prior to ground water recharge. Soil clogging at the infiltrative surface of WSAS occurs due to the accumulation of suspended solids, organic matter, and chemical precipitates during continued wastewater infiltration. This clogging zone (CZ) creates an impedance to flow, restricting the hydraulic conductivity and rate of infiltration. A certain degree of clogging may improve the treatment of wastewater by enhancing purification processes, in part because unsaturated flow is induced and residence times are significantly increased. However, if clogging becomes excessive, the wastewater pond height at the infiltrative surface can rise to a level where system failure occurs. The numerical model HYDRUS-2D is used to simulate unsaturated flow within WSAS to better understand the effect of CZs on unsaturated flow behavior and hydraulic retention times in sandy and silty soil. The simulations indicate that sand-based WSAS with mature CZs are characterized by a more widely distributed flow regime and longer hydraulic retention times. The impact of clogging on water flow within the silt is not as substantial. For sand, increasing the hydraulic resistance of the CZ by a factor of three to four requires an increase in the pond height by as much as a factor of five to achieve the same wastewater loading. Because the degree of CZ resistance directly influences the pond height within a system, understanding the influence of the CZ on flow regimes in WSAS is critical in optimizing system design to achieve the desired pollutant-treatment efficiency and to prolong system life.
The mechanical behavior of β-LiAl

Abstract The plastic deformation of β phase LiAl has been studied through compression tests. Polycrystalline LiAl is brittle at temperatures below 0.7Tm where Tm is the melting temperature). The ductile-to-brittle transition temperature increases with increasing lithium content. The isotherms of the yield strength showed an increase in strength with increasing lithium content. The compositional dependence of the ductile-to-brittle transition temperature and the yield strength are correlated with the defect structure of β-LiAl. Strain-rate-cycling tests were performed to obtain the activation volumes of plastic deformation of LiAl. The magnitude of the activation volumes is quite small and independent of lithium content. The rate-controlling deformation mechanism may be associated with the nucleation of dislocation kink pairs over a Peierls-Nabarro barrier.
The Russo–American dispute over the invasion of Iraq: international status and the role of positional goods

The war in Iraq will have a significant effect on the psychological and political climate in Russia. … The American–Iraqi conflict seems to have brought to light a public demand that we regain our ...
Anatomic relationships of the human arcuate nucleus of the medulla : A diI-labeling study

The arcuate nucleus (ARC) at the ventral surface of the human medulla has been historically considered a precerebellar nucleus. More recently, it has been implicated in central chemoreception, cardiopulmonary coupling and blood pressure responses. A deficiency of the ARC has been reported in a subset of putative human developmental disorders of ventilatory function. To investigate anatomic relationships of the ARC with brainstem regions involved in cardiorespiratory control, we applied crystals of DiI, a lipophilic dye which labels cells and cell processes by lateral diffusion along cell membranes, to 23 paraformaldehyde-fixed human fetal brainstems at 19 to 22 weeks postconceptional age. After 7 to 15.5 months diffusion, serial frozen sections were examined by florescence microscopy. DiI diffusion from the ARC labeled fibers and cell bodies in the medullary raphe labeled the reticular formation, medullary raphe, and the ARC. Diffusion from the pyramid and the basis pontis (negative control) labeled the corticospinal tract, with no labeling of the medullary raphe or ARC. The results suggest the existence of cellular connections between the ARC and the caudal raphe, a region implicated in cardiorespiratory control.
Dissecting the streptavidin-biotin interaction by phage-displayed shotgun scanning

Shotgun scanning the streptavidin-biotin interaction identifies long-range hydrophobic interactions that contribute to one of the strongest naturally occurring noncovalent protein-ligand interactions. The femtomolar dissociation constant for this interaction makes it a useful model system to dissect the forces that govern high-affinity molecular recognition between proteins and small molecules. Shotgun scanning combines the diversity and in vitro binding selection of phage-displayed libraries with a binomial mutagenesis strategy. Libraries consist of proteins with the residues in multiple positions mutated to give a 1:1 ratio of alanine:wild type. Here, we use shotgun scanning to determine the functional contribution of the 38 C-terminal residues of streptavidin to the high-affinity interaction with biotin. The library pools were subjected to three rounds of selection for functional streptavidin variants that bind biotin and statistical analysis was used to assess side-chain contributions to biotin binding. The results demonstrate the utility of shotgun scanning for the dissection of receptor-small-molecule interactions. While shotgun scanning results were largely consistent with previous single-point, site-directed mutagenesis studies for residues in direct contact with biotin, residues distant from the biotin binding site have not previously been explored. Key streptavidin residues identified by shotgun scanning as contributors to the interaction with biotin include those with side chains that fill the beta barrel, residues at the tetramer interface, and second-sphere residues, which are reinforced by long-distance propagation of hydrophobic interactions.
Stochastic end-user model for forecasting load statistics

Abstract A stochastic end-user model of utility load is presented. The model is used to develop statistics of the daily load based upon readily available weather data. A detailed procedure is presented for the residential sector.
An observer-based piezoelectric control of flexible Cartesian robot arms: theory and experiment

An observer-based control strategy is proposed for regulating problem of a Cartesian robot arm, which is modeled as a flexible cantilever beam with a translational base support. The base motion is controlled utilizing an electrodynamic shaker, while a piezoelectric (PZT) patch actuator is bonded on the surface of the flexible beam for suppressing residual arm vibrations. Taking into account both electrical and mechanical fields for the PZT patch actuator, a full-order model is developed using assumed mode model expansion and the Lagrangian approach. Utilizing three measurable quantities (i.e., the base displacement, arm tip deflection and the strain at the root end of the arm), a reduced-order observer is designed to estimate the velocity related variables, which are not directly measurable for the truncated model. A simple PD controller is selected for the moving base regulation, while a Lyapunov-based controller is utilized for the PZT input voltage to make the closed-loop system energy dissipative and hence stable. The PZT input voltage control uses the velocity related signals estimated by the reduced-order observer, which simplifies the control implementation in practice. The feasibility of the controller is validated through both numerical simulations and experimental testing. Significant matching between experimental results and numerical simulation is observed.
Exogenous control of mammalian gene expression via modulation of translational termination

Here, we describe a system for the exogenous control of gene expression in mammalian cells that relies on the control of translational termination. To achieve gene regulation, we modified protein-coding sequences by introduction of a translational termination codon just downstream from the initiator AUG codon. Translation of the resulting mRNA leads to potent reduction in expression of the desired gene product. Expression of the gene product can be controlled by treating cells that express the mRNA with either aminoglycoside antibiotics or several nonantibiotic compounds. We show that the extent of regulation of gene expression can be substantial (60-fold) and that regulation can be achieved in the case of a variety of different genes, in different cultured cell lines and in primary cells in vivo. This gene regulation strategy offers significant advantages over existing methods for controlling gene expression and should have both immediate experimental application and possible clinical application.
ACTH Secretion Due to Hypothalamo-Pituitary Effects of Adenosine-3′5′-monophosphate and Related Substances

Adenosine-3′,5′-monophosphate (cAMP) and related substances were tested for their ability to cause ACTH release upon stereotaxic microinjection into brain or adenohypophysis of dexamethasone-pretreated rats. Intrapituitary injections of the dibutyryl analog of cAMP (DBcAMP) resulted in increased ACTH secretion as indicated by plasma corticosterone levels. Significant increases in ACTH release were also seen in response to theophylline, but not to caffeine. cAMP itself in the pituitary was effective only if preceded by theophylline. Solutions containing high potassium concentrations were also effective only in theophylline- primed pituitaries. Adenosine-5′-monophosphate had no effect on ACTH secretion. Injections of theophylline and DBcAMP into the basal hypothalamus evoked responses similar to those due to the pituitary injections. All doses used had no effect on ACTH secretion when administered intravenously. Responses to both pituitary and hypothalamic injections of these substances were decreased by pr...
cDNA Cloning and Characterization of Murine Transcriptional Enhancer Factor-1-related Protein 1, a Transcription Factor That Binds to the M-CAT Motif

The M-CAT motif is a cis-regulatory DNA sequence that is essential for muscle-specific transcription of several genes. Previously, we had shown that both muscle-specific (A1) and ubiquitous (A2) factors bind to an essential M-CAT motif in the myosin heavy chain β gene and that the ubiquitous factor is transcriptional enhancer factor (TEF)-1. Here we report the isolation of mouse cDNAs encoding two forms (a and b) of a TEF-1-related protein, TEFR1. The TEFR1a cDNA encodes a 427-amino acid protein. The coding region of TEFR1b is identical to 1a in both nucleotide and predicted amino acid sequence except for the absence of 43 amino acids downstream of the TEA DNA-binding domain. Three TEFR1 transcripts (∽7, ∽3.5, and ∽2 kilobase pairs) are enriched in differentiated skeletal muscle (myotubes) relative to undifferentiated skeletal muscle (myoblasts) and non-muscle cells in culture. In situ hybridization analysis indicated that TEFR1 transcripts are enriched in the skeletal muscle lineage during mouse embryogenesis. Transient expression of fusion proteins of TEFR1 and the yeast GAL4 DNA-binding domain in cell lines activated the expression of chloramphenicol acetyltransferase (CAT) reporter constructs containing GAL4 binding sites, indicating that TEFR1 contains an activation domain. An anti-TEFR1 polyclonal antibody supershifted the muscle-specific M-CAT•A1 factor complex in gel mobility shift assays, suggesting that TEFR1 is a major component of this complex. Our results suggest that TEFR1 might play a role in the embryonic development of skeletal muscle in the mouse.
Selective activation of group II mGluRs with LY354740 does not prevent neuronal excitotoxicity

Abstract Recent reports have suggested a role for group II metabotropic glutamate receptors (mGluRs) in the attenuation of excitotoxicity. Here we examined the effects of the recently available group II agonist (+)-2-Aminobicyclo[3.1.0]hexane-2-6-dicarboxylic acid (LY354740) on N -methyl- d -aspartate (NMDA)-induced excitotoxic neuronal death, as well as on hypoxic-ischemic neuronal death both in vitro and in vivo. At concentrations shown to be selective for group II mGluRs expressed in cell lines (0.1–100 nM), LY354740 did not attenuate NMDA-mediated neuronal death in vitro or in vivo. Furthermore, LY354740 did not attenuate oxygen-glucose deprivation-induced neuronal death in vitro or ischemic infarction after transient middle cerebral artery occlusion in rats. In addition, the neuroprotective effect of another group II agonist, ( S )-4-carboxy-3-phenylglycine (4C3HPG), which has shown injury attenuating effects both in vitro and in vivo, was not blocked by the group II antagonists (2 S )-α-ethylglutamic acid (EGLU), ( RS )-α-methyl-4-sulphonophenylglycine (MSPG), or the group III antagonist ( S )-α-methyl-3-carboxyphenylalanine (MCPA), suggesting that this neuroprotection may be mediated by other effects such as upon group I mGluRs.
Oxygen sensing for in-vivo imaging by photoacoustic lifetime probing

We have developed a new method to perform local measurements of fluorophore excited state lifetimes in turbid media without collecting the fluorescence emission. The method is based on a double pulse illumination where a first laser pulse excites the dye and then a second laser is used for photoacoustic probing of the transient absorption. The photoacoustic response generated by the probe pulse is recorded by an ultrasound receiver. Varying the time delay between excitation and probing allows for tracking the relaxation dynamics of the excited state. The method was validated by measuring the lifetime of an oxygen sensitive dye (Pt(II) octaethylporphine) solution at different concentrations of dissolved oxygen. The dye was excited with a 532 nm pulsed laser and the transient absorption at 740 nm was probed using a second pulsed laser system. The photoacoustics based results coincide with those obtained from simultaneous time-resolved fluorescent measurements. The method can be extended to photoacoustic lifetime imaging by using a receiver array instead of a single receiver. This opens unique possibilities for non-invasive, clinical functional imaging. For example, combined with oxygen sensitive dye, 3D imaging of tissue oxygenation could be developed for accurate diagnosis of cancer tumors, better planning of radiation therapy, and monitoring efficacy of treatment. Other potential applications include: in-vivo mapping of ion (e.g. Ca) concentration and dynamics and imaging of enzymes activity and metabolic functions, as well as environmental studies in turbid media.
Phylogenetic relationships of Mesoamerican spider monkeys (Ateles geoffroyi): Molecular evidence suggests the need for a revised taxonomy

Mesoamerican spider monkeys (Ateles geoffroyi sensu lato) are widely distributed from Mexico to northern Colombia. This group of primates includes many allopatric forms with morphologically distinct pelage color and patterning, but its taxonomy and phylogenetic history are poorly understood. We explored the genetic relationships among the different forms of Mesoamerican spider monkeys using mtDNA sequence data, and we offer a new hypothesis for the evolutionary history of the group. We collected up to ∼800 bp of DNA sequence data from hypervariable region 1 (HV1) of the control region, or D-loop, of the mitochondrion for multiple putative subspecies of Ateles geoffroyi sensu lato. Both maximum likelihood and Bayesian reconstructions, using Ateles paniscus as an outgroup, showed that (1) A. fusciceps and A. geoffroyi form two different monophyletic groups and (2) currently recognized subspecies of A. geoffroyi are not monophyletic. Within A. geoffroyi, our phylogenetic analysis revealed little concordance between any of the classifications proposed for this taxon and their phylogenetic relationships, therefore a new classification is needed for this group. Several possible clades with recent divergence times (1.7-0.8 Ma) were identified within Ateles geoffroyi sensu lato. Some previously recognized taxa were not separated by our data (e.g., A. g. vellerosus and A. g. yucatanensis), while one distinct clade had never been described as a different evolutionary unit based on pelage or geography (Ateles geoffroyi ssp. indet. from El Salvador). Based on well-supported phylogenetic relationships, our results challenge previous taxonomic arrangements for Mesoamerican spider monkeys. We suggest a revised arrangement based on our data and call for a thorough taxonomic revision of this group.
Public relations education: Where is pedagogy?

Abstract The year 1998 was a significant time for public relations education. Data for the Public Relations Education Survey were collected and analyzed and public relations educators met in suburban Washington, D.C. for the National Communication Association's Summer Conference on Public Relations Education to discuss the survey and its implications for public relations education. Pedagogy was one of the four major discussion topics at the conference. This article synthesizes results from the survey and discussions of the Pedagogy Task Team at the conference. A hopeful picture of public relations pedagogy emerged from the data and discussions. Current pedagogy places an emphasis on active learning, an important strength in the delivery of course material. But the picture includes weaknesses, too. Public relations educators are rather slow to utilize new technology in the classroom. Moreover, public relations as a field has not given enough attention to pedagogy. Research of public relations pedagogy is sparse, pedagogical tools are weak and teacher training is minimal. Placing more emphasis on public relations pedagogy will help to overcome these weaknesses and build on its strengths.
Investigations of static properties of model bulk polymer fluids

The static properties of continuum, multichain systems are investigated by a ’’reptation’’ Monte Carlo algorithm. All beads interact via a repulsive (shifted) Lennard‐Jones potential. In addition, nearest neighbors along chains are linked by a quasiharmonic potential which permits limited pair extensions. Chain lengths of 5, 10, 20, 32, 50, and 70 beads have been studied. Studies at densities of 0.1, 0.3, and 0.5 demonstrate that chain dimensions are compressed as the concentration is increased. Both the mean square end‐to‐end distance, 〈R2〉, and the mean square radius of gyration, 〈S2〉, have a power law dependence upon l‐1, the number of bonds, with exponent approximately 1.16 for ρ=0.1 and 1.07 for ρ=0.3 and 0.5. 〈R2〉 and 〈S2〉 scale with density as ρ−γ where γ∼−0.22±0.02 for long chains, in reasonable agreement with the scaling prediction of −0.25. The asphericity ratios, the pair correlation functions of the center of masses, and the extent of chain overlaps indicate the nonideal behavior of these systems.
Future land-use scenarios and the loss of wildlife habitats in the southeastern United States

Land-use change is a major cause of wildlife habitat loss. Understanding how changes in land-use policies and economic factors can impact future trends in land use and wildlife habitat loss is therefore critical for conservation efforts. Our goal here was to evaluate the consequences of future land-use changes under different conservation policies and crop market conditions on habitat loss for wildlife species in the southeastern United States. We predicted the rates of habitat loss for 336 terrestrial vertebrate species by 2051. We focused on habitat loss due to the expansion of urban, crop, and pasture. Future land-use changes following business-as-usual conditions resulted in relatively low rates of wildlife habitat loss across the entire Southeast, but some ecoregions and species groups experienced much higher habitat loss than others. Increased crop commodity prices exacerbated wildlife habitat loss in most ecoregions, while the implementation of conservation policies (reduced urban sprawl, and payments for land conservation) reduced the projected habitat loss in some regions, to a certain degree. Overall, urban and crop expansion were the main drivers of habitat loss. Reptiles and wildlife species associated with open vegetation (grasslands, open woodlands) were the species groups most vulnerable to future land-use change. Effective conservation of wildlife habitat in the Southeast should give special consideration to future land-use changes, regional variations, and the forces that could shape land-use decisions.
Glacier Geophysics: Dynamic response of glaciers to changing climate may shed light on processes in the earth's interior.

From physical measurements on glaciers and experimental studies of ice properties a framework of concept and theory is being built which bids fair to place glaciers among the more quantitatively understandable phenomena in the earth sciences. Measurements of flow velocity, deformation and stress, ice thickness and channel configuration, temperature, internal structure of theice, mass and energy balance, and response to meteorological variables all contribute to this understanding, as do still other measurements hardly discussed here, such as electrical properties, radioactive age measurements, and detailed studies of chemical and isotopic composition. The obvious goals of this work—the interpretation of past and present glacier fluctuations in terms of changes in world climate, and the prediction of glacier behavior—remain elusive, even though a good conceptual groundwork has been laid for dealing with the more tractable aspects of these problems. Intriguing recent discoveries have been made about such matters as the way in which glaciers react dynamically to changing conditions, the inter-relations between thermal regime and ice motion, the structural mechanisms of glacier flow, and the changes produced in ice by flow. One can recognize in these developments the possibility that concepts derived from the study of glacier flow may be applicable to phenomena of solid deformation deep in the earth. In this way glacier geophysics may have a useful impact beyond the study of glaciers themselves.
Prey size, prey abundance, and temperature as correlates of growth in stream populations of cutthroat trout

Growth and maximum size of stream fishes can be highly variable across populations. For salmonid fishes in streams, individuals from populations confined to headwater streams often exhibit small size at maturity in comparison to populations with access to main-stem rivers. Differences in prey size, prey availability, and metabolic constraints based on temperature may explain patterns of maximum size and growth. In this study, cutthroat trout from headwater stream populations that were isolated above a waterfall were compared to individuals from populations in similar sized streams without a movement barrier and from large main-stem rivers. Cutthroat trout from smaller streams with or without a movement barrier were significantly smaller at a given age than fish from main-stem rivers, where individuals were able to achieve a much larger maximum size. Comparisons of invertebrate drift abundance and size in the three types of streams revealed that drift size did not differ between stream categories, but was highest per volume of water in large main-stem rivers. Across all stream types, prey abundance declined from summer to fall. Temperature declined over the course of the season in a similar manner across all stream types, but remained relatively high later in the season in main-stem river habitats. Prey availability and temperature conditions in main-stem rivers may provide more optimal growing conditions for fish as individuals increase in size and become constrained by prey availability and temperature conditions in small streams. Maintaining connectivity between small spawning and rearing tributary streams and main-stem river habitats may be critical in maintaining large-bodied populations of stream salmonids.
Recent developments in aircraft protection systems for laser guide star operations

The astronomical community's use of high power laser guide star adaptive optics (LGS-AO) systems presents a potential hazard to aviation. Historically, the most common and trusted means of protecting aircraft and their occupants has been the use of safety observers (aka spotters) armed with shut-off switches. These safety observers watch for aircraft at risk and terminate laser propagation before the aircraft can be adversely affected by the laser. Efforts to develop safer and more cost-effective automated aircraft protection systems for use by the astronomical community have been inhibited by both technological and regulatory challenges. This paper discusses recent developments in these two areas. Specifically, with regard to regulation and guidance we discuss the 2011 release of AS-6029 by the SAE as well as the potential impact of RTCA DO-278A. With regard to the recent developments in the technology used to protect aircraft from laser illumination, we discuss the novel Transponder Based Aircraft Detection (TBAD) system being installed at W. M. Keck Observatory (WMKO). Finally, we discuss our strategy for evaluating TBAD compliance with the regulations and for seeking appropriate approvals for LGS operations at WMKO using a fully automated, flexibly configured, multi-tier aircraft protection system incorporating this new technology.
Estimating the effect of biofuel on land cover change using multi-year MODIS land cover data

There has been a growing debate on the effects of the increase in demands of biofuels on land use land cover (LULC) change with apprehension in some quarters that the growing demand forf bioenergy as a clean fuel will result in widespread direct and indirect LULC change. However estimating both direct and indirect LULC change is challenging and will require development of accurate high frequency, high resolution (temporal and spatial) land use land cover data as well as new LULC models which can be used to locate, quantify and predict these changes. To assess whether the demand for biofuel has caused LULC we used MODIS land cover data (MCD12Q1) from 2001 to 2008 along with cropland data layer (CDL) to estimate cropland and grassland changes in United States for the years 2002–2008 as well as its correlation with biofuel growth.
Pubertal Timing and Early Sexual Intercourse in the Offspring of Teenage Mothers

Early puberty is associated with stressful family environments, early sexual intercourse, and teenage pregnancy. We examined pubertal timing and sexual debut among the 14-year-old offspring of teenage mothers. Mothers (71% Black, 29% White) were recruited as pregnant teenagers (12–18 years old). Data were collected during pregnancy and when offspring were 6, 10 and 14 years old (n = 318). Adolescents (50% male) compared the timing of their pubertal maturation to same-sex peers. There was a significant 3-way interaction effect of race, sex, and pubertal timing on sexual debut (n = 305). This effect remained significant in a model controlling for maternal age at first intercourse, substance use, exposure to trauma, authoritative parenting, and peer sexual activity (n = 255). Early maturation was associated with early sex in daughters, and may be one pathway for the inter-generational transfer of risk for teenage pregnancy among daughters of teenage mothers.
Three Dimensional Tomography of Heliospheric Features Using Global Thomson Scattering Data

Abstract Images of the heliosphere will become available from the Air Force/NASA Solar Mass Ejection Imager (SMEI), and from the all-sky cameras proposed for the NASA missions STEREO, Solar Probe and Solar Polar Sail. To optimize the information available from these instruments, their 2-dimensional images need to be interpreted in three dimensions. We have developed a Computer Assisted Tomography (CAT) program that modifies a three-dimensional heliospheric model to fit Thomson scattering solar minimum observations from the Helios spacecraft photometers. The tomography program iterates to a least-squares solution fit of observed brightness data using spacecraft and solar wind motion to provide perspective views of each point in space accessible to the observations. We plot the optimized models as Carrington maps in density for the Helios data sets. The results to date are commensurate with resolutions available from the original data. At solar minimum, longitudinally segmented dense structures emanate from near the solar equator. We explore the location of these dense structures with respect to the heliospheric current sheet and regions of activity on the solar surface.
Online detection of unusual events in videos via dynamic sparse coding

Real-time unusual event detection in video stream has been a difficult challenge due to the lack of sufficient training information, volatility of the definitions for both normality and abnormality, time constraints, and statistical limitation of the fitness of any parametric models. We propose a fully unsupervised dynamic sparse coding approach for detecting unusual events in videos based on online sparse re-constructibility of query signals from an atomically learned event dictionary, which forms a sparse coding bases. Based on an intuition that usual events in a video are more likely to be reconstructible from an event dictionary, whereas unusual events are not, our algorithm employs a principled convex optimization formulation that allows both a sparse reconstruction code, and an online dictionary to be jointly inferred and updated. Our algorithm is completely un-supervised, making no prior assumptions of what unusual events may look like and the settings of the cameras. The fact that the bases dictionary is updated in an online fashion as the algorithm observes more data, avoids any issues with concept drift. Experimental results on hours of real world surveillance video and several Youtube videos show that the proposed algorithm could reliably locate the unusual events in the video sequence, outperforming the current state-of-the-art methods.
Using Student-Generated UV-Induced Escherichia coli Mutants in a Directed Inquiry Undergraduate Genetics Laboratory

We report a thematic sequence of directed inquiry-based labs taking students from bacterial mutagenesis and phenotypic identification of their own self-created mutant, through identification of mutated genes by biochemical testing, to verification of mutant alleles by complementation, and finally to mutant allele characterization by DNA sequence analysis. The lab utilizes UV mutagenesis with wild-type Escherichia coli and a UV-sensitive isogenic derivative optimized for undergraduate use. The labs take advantage of the simplicity of E. coli in a realistic genetic investigation using safe UV irradiation methods for creation and characterization of novel mutants. Assessment data collected over three offerings of the course suggest that the labs, which combine original investigation in a scientifically realistic intellectual environment with learned techniques and concepts, were instrumental in improving students' learning in a number of areas. These include the development of critical thinking skills and understanding of concepts and methods. Student responses also suggest the labs were helpful in improving students' understanding of the scientific process as a rational series of experimental investigations and awareness of the interdisciplinary nature of scientific inquiry.
Genetic versus environmental influence on pigment variation in the ephippia of Daphnia pulicaria

SUMMARY 1. The dormant eggs of Daphnia (Crustacea: cladocera) are encased in a protective, chitonous casing known as an ephippium. Ephippia are pigmented with melanin, and the degree of pigmentation ranges from transparent to opaque. Variation in pigmentation exists within and across populations and species, raising questions about the factors that influence the natural distribution of pigmentation. 2. We used image analysis to quantify pigmentation in ephippial casings of Daphnia pulicaria that were produced both in the field and in the laboratory. The percentage of the surface area of ephippia that is darkly pigmented ranged from 0.5 to 99.5%. The range, mean and variance of ephippial pigmentation varied across our 11 study lakes. 3. Laboratory experiments compared clonal variation (five clones/lake) and population variation (five lakes) at three temperatures (15 � C, 20 � C and 25 � C). The degree of pigment variation between clones was much greater than pigment variation between temperatures, indicating that there is a genetic component to pigmentation in the ephippia which is stronger than the effect of temperature. 4. Comparisons of pigment levels and lake characteristics were used to identify physical and biological factors associated with ephippial pigmentation. Investment in ephippial production was the strongest predictor with darker ephippia occurring more often in lakes with the highest ephippial production.
Quantification of bound and free enzymes during enzymatic hydrolysis and their reactivities on cellulose and lignocellulose

Enzymatic hydrolysis of insoluble biomass is a surface reaction. Part of the enzyme adsorb on the surface of biomass, whereas the others stay in the liquid phase. In this study, three substrates (Avicel cellulose, bleached hardwood pulp, and green-liquor pretreated hardwood pulp) were used to study the reactivity of bound and free enzyme. In a continuous enzymatic hydrolysis, 35-65% initially added enzymes became bound enzymes, which were primarily responsible for enzymatic hydrolysis. The contribution from free enzymes became insignificant after a certain period of reaction time. SDS-PAGE analysis showed that CBH I was significantly decreased in the free enzyme, which might be the reason for the low digestibility of free enzymes due to the loss of synergistic effect. When Tween 80 was added during enzymatic hydrolysis, the digestibility of free enzyme on Avicel was greatly enhanced. However, the benefit of surfactant was not noticeable for lignocellulosic pulps, comparing to Avicel.