cssi/SciSciGPT-SciSciNet huggingface dataset:
Peptide deformylase: a target for novel antibiotics?

Peptide deformylase (PDF) catalyses the hydrolytic removal of the N-terminal formyl group from nascent ribosome-synthesised polypeptides. Its activity is essential and it is present in all eubacteria. It is also present in the organelles of some eukaryotes. PDF represents a novel class of mononuclear iron protein, utilising an Fe2+ ion to catalyse the hydrolysis of an amide bond. Due to its extreme lability, isolation and characterisation of PDF was not possible until very recently. This review will discuss the recent progress in the elucidation of the the structure and function of PDF, evaluating its suitability as a target for antibiotic design and summarising the current approaches to designing drugs that target PDF.
Pelleted beet pulp substituted for high-moisture corn: 1. Effects on feed intake, chewing behavior, and milk production of lactating dairy cows.

Abstract The effects of increasing concentrations of dried, pelleted beet pulp substituted for high-moisture corn on intake, milk production, and chewing behavior were evaluated using eight ruminally and duodenally cannulated multiparous Holstein cows in a duplicated 4 × 4 Latin square design with 21-d periods. Cows were 79 ± 17 (mean ± SD) d in milk at the beginning of the experiment. Experimental diets with 40% forage (corn silage and alfalfa silage) and 60% concentrate contained 0, 6.1, 12.1, or 24.3% beet pulp substituted for high-moisture corn on a dry matter basis. Diet concentrations of neutral detergent fiber (NDF) and starch were 24.3 and 34.6% (0% beet pulp), 26.2 and 30.5% (6% beet pulp), 28.0 and 26.5% (12% beet pulp), and 31.6 and 18.4% (24% beet pulp), respectively. Increasing beet pulp in the diet caused a linear decrease in dry matter intake (DMI). Time spent eating per day and per kilogram of DMI increased, and sorting against NDF tended to increase, with added beet pulp. Substituting beet pulp for corn caused a quadratic response in milk fat yield, with the highest yield for the 6% beet pulp treatment. A tendency was detected for a similar quadratic response in 3.5% fat-corrected milk yield. Lower plasma insulin concentration may have resulted in lower body condition gain for cows fed diets with higher beet pulp concentration. Partial substitution of pelleted beet pulp for high-moisture corn decreased intake but also may have permitted greater fat-corrected milk yield.
Feedback regulation of cholesterol synthesis: sterol-accelerated ubiquitination and degradation of HMG CoA reductase

3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase produces mevalonate, an important intermediate in the synthesis of cholesterol and essential nonsterol isoprenoids. The reductase is subject to an exorbitant amount of feedback control through multiple mechanisms that are mediated by sterol and nonsterol end-products of mevalonate metabolism. Here, I will discuss recent advances that shed light on one mechanism for control of reductase, which involves rapid degradation of the enzyme. Accumulation of certain sterols triggers binding of reductase to endoplasmic reticulum (ER) membrane proteins called Insig-1 and Insig-2. Reductase-Insig binding results in recruitment of a membrane-associated ubiquitin ligase called gp78, which initiates ubiquitination of reductase. This ubiquitination is an obligatory reaction for recognition and degradation of reductase from ER membranes by cytosolic 26S proteasomes. Thus, sterol-accelerated degradation of reductase represents an example of how a general cellular process (ER-associated degradation) is used to control an important metabolic pathway (cholesterol synthesis).
Cloning of a second Arabidopsis peptide transport gene.

Previously, we reported the isolation of a peptide transport gene designated AtPTR2 from Arabidopsis thaliana by functional complementation of a yeast peptide transport mutant. We now report the isolation of a second peptide transport gene (AtPTR2-B) from Arabidopsis using the same approach. Similar to the effects of transferring AtPTR2-A (previously called AtPTR2), transfer of AtPTR2-B to yeast peptide transport mutants restored the ability to grow on di- and tripeptides but not peptides four residues or longer. However, unlike yeast mutants complemented with either the yeast PTR2 gene or the AtPTR2-A gene, transformants expressing AtPTR2-B were only partially sensitive to toxic peptides. Northern analysis showed that AtPTR2-B was constitutively expressed in all plant organs. Studies of the kinetics indicated that AtPTR2-A and AtPTR2-B have Km values of 47 and 14 [mu]M, respectively, with Vmax values of 0.061 and 0.013 nmol mg-1 cell dry weight s-1, respectively, when dileucine was used as a substrate. AtPTR2-B is encoded on a 2.0-kb cDNA corresponding to a 585-amino acid protein (64.4 kD). Hydropathy analysis indicates that the protein is highly hydrophobic and suggests that there are 12 putative transmembrane segments. AtPTR2-B, like AtPTR2-A, shares significant similarity to a number of other proteins involved in transport of peptides into cells.
Children’s use of multiple and variable addition strategies in a game context

Developmental and contextual effects on children’s addition strategies were assessed in preschool, kindergarten and first-grade children’s strategy use while playing a board game (‘Chutes and Ladders’), using one or two dice to compute moves. Children of all ages displayed multiple- and variable-strategy use, and there was a progression toward more sophisticated strategy use with age. Different patterns of strategy use in the two-dice condition were observed as a function of whether children began the game with one versus two dice and for children who could recognize (as opposed to having to count) die roles of ‘5’ and ‘6’ in the one-die condition. An examination of latencies indicated that more noncounting (start-up) time was required to execute the MIN than the SUM strategy. Children showed significantly greater speed and accuracy when adding numbers during the game than in the math problems that followed. The findings reflect young children’s flexible use of strategies and extend Siegler’s adaptive strategy choice model to the development of simple addition strategies in an everyday context.
Female spadefoot toads compromise on mate quality to ensure conspecific matings

When high-quality conspecifics resemble heterospecifics, females may be unable to engage effectively in both species recognition (identification of conspecifics) and mate-quality recognition (identification of high-quality mates). Consequently, females that engage primarily in mate-quality recognition may risk heterospecific matings, and females that engage primarily in species recognition may risk mating with low-quality mates. I examined the evolutionary consequences of this conflict between species and mate-quality recognition in spadefoot toads, Spea multiplicata. I compared mate preferences and the fitness consequences of these preferences in spadefoot toad populations that did and did not overlap with congeners. In non-overlapping populations, S. multiplicata females preferred an extreme call character resembling that of heterospecifics, and they had more eggs fertilized. In overlapping populations, S. multiplicata females preferred those call characteristics that were closest to the norm for their population, and they did not receive the benefit of enhanced fertilization success. Thus, S. multiplicata females appear to trade off species and mate-quality recognition, such that those co-occurring with heterospecifics forgo the benefits of high-quality matings to ensure conspecific matings. These results suggest that the interaction between species and mate-quality recognition may influence mate choice decisions in important and nonintuitive ways. Key words: mate choice, mate-quality recognition, species recognition, Scaphiopus couchii, Spea bombifrons, Spea multiplicata. [Behav Ecol 11:220–227 (2000)]
Glossary of Biomechanical Terms, Concepts, and Units

In the last decade, physical therapists have recognized that the field of biomechanics has become an area of study that can contribute significantly to the profession; therefore, it has become a part of most curricula. Biomechanics represents an amalgamation of several different fields including mechanics, physics, engineering, anatomy, physiology, and mathematics. More recently, elements of computer science and electronics have also become integral components. The breadth of knowledge required is therefore substantial, and we are not surprised about the lack of precision concerning terminology in certain areas. A lack of formal background during professional preparation may lead to the misuse of some terms because of the relative infancy of biomechanics. The simultaneous inclusion of biomechanics into the body of knowledge of other fields such as orthopedics, ergonomics, prosthetics, and podiatry have sometimes led to disagreement over basic definitions and concepts, which have developed different meanings in different fields.
Influence of I-E expression on induction of neonatal transplantation tolerance.

Neonatal transplantation tolerance was one of the first experimental systems to reveal that tolerance could be achieved to non-self antigens in living animals. Functional and direct evidence (obtained by the use of monoclonal antibodies directed at T cell receptors specifically reactive with I-E molecules) confirm that tolerance is achieved, at least in part, via clonal elimination of developing thymocytes. In this report, we show that induction of tolerance of class I alloantigens in neonatal mice is governed by expression of I-E molecules. Neonatal I-E non-expressor mice proved to be highly resistant to the acquisition of class I tolerance if the donor inoculum expressed disparate class I antigens as well as I-E molecules. The spleens of the few class I-tolerant, I-E non-expressor mice that were generated were found to be depleted of I-E-reactive (RR315+) T cells, whereas no such depletion was observed in their neonatally injected, but non-tolerant littermates. By contrast we found no resistance to tolerance of I-A alloantigens when neonatal I-E non-expressor mice received injections of I-A-disparate, I-E-bearing donor cells. In these tolerant mice, splenic I-E-reactive T cells were readily detected in apparently normal amounts. These results indicate that lack of I-E expression in newborn mice confers resistance to tolerance induction to class I alloantigens, especially when the latter are expressed on donor cells that also display I-E molecules. The possible mechanisms operating to produce resistance to tolerance induction in neonatal mice are discussed, including the possibilities that (a) I-E may act as a restricting element during tolerance induction (an ontogenic process), and (b) the expression of I-E on H-2-disparate, I-E-expressing test skin allografts may provide a source of “help” for CD8+ cytotoxic T cell precursors, leading to graft rejection.
Making service learning accessible to computer scientists

Service learning can play an important role in computer science education: it can address declining enrollments and increase current student satisfaction. Although computer science poses some serious problems for effectively implementing service learning, these can be surmounted by reconfiguring a course to include a substantial treatment of accessibility. I describe such a course, explain how it overcomes the problems, and discuss the results of the course from a student perspective.
The rhetoric of architecture in the Byzantine context: The case study of the Holy Sepulchre

This paper examines the rhetorical capacity of architecture, and in particular, “the rhetoric of architecture” rather than the usually examined “rhetoric about architecture.” In this work, the rhetoric of architecture is understood as codified visual and architectural conventions as a series of transpositions that frame specific meanings other than and beyond visible and spatial. Here the proposed “rhetoric of architecture” is also more about its capacity as a “mnemonic tool” and about the “craft of composition” rather than about persuading others or about representation based on exact likeness. This concept is particularly significant in the creation of the sacred. By focusing on the architecture of the critical building of the Holy Sepulchre that enclosed the Tomb Shrine in Jerusalem as described by Patriarch Photios in the ninth and Abbot Daniel in the early twelfth centuries, this paper argues for the recognition of the mnemonic links that the Byzantines may have used not only for remembering the Tomb of Christ, but also for their several reconstructions of the Holy Sepulchre in Jerusalem as well as for embedding the meaning of Jerusalem and New Jerusalem in their churches built elsewhere.
The Use of Prior Information in Regression Analysis

For the past five years the author has been serving as a consultant to the Technical Staff of the Missile Division of Pan-American World Airways at Patrick Air Force Base, Florida. One of the major tasks of the Technical Staff is the analysis of missile trajectory data. For the past decade, one of the most intriguing problems has been that of determining the Best Estimate of Trajectory (BET) based on pooling information obtained from a number of range instrumentation systems, simultaneously tracking a given missile. Pooling these observations is complicated by three problems: (1) Differential weighting is required, because the variance of the random variation is not constant from one system to another; in addition, it is not constant for a given system throughout a given flight and from flight to flight. (2) Observations for different systems may be correlated. (3) Each system has a number of systematic calibration biases which change from flight to flight, but which may be more or less stable for a given flight. Since the systems usually have entirely different electronic components, different systematic biases must be determined for each system.
Optimal Seeding of a Class of Self-Reproducing Systems

This paper is motivated by the need to minimize the payload mass required to establish an extraterrestrial robotic colony. One approach for this minimization is to deploy a colony consisting of individual robots capable of self-reproducing. An important consideration for the establishment of such a colony is the identification of a seed. Since self-reproduction is achieved by the actions of a robot on available resources, a seed for the colony consists of a set of robots and a set of resources. Previous approaches to the seeding problem included certain restrictive assumptions about the self-reproducing system under consideration, possibly yielding seeds with an excessive number of resources. The algorithms were also incapable of seeding self-reproducing systems where the production of copies of progenitor robots required the assistance of their offspring. This paper outlines a novel algorithm to determine an optimal seed for a more general class of self-reproducing systems. Here, optimality is understood as the minimization of a cost function of the resources and robots, and the class of self-reproducing systems is more general because it allows the generation of a copy of a robot to depend on the assistance of its offspring. Illustrations of the algorithm are provided.
In vitro Tumorsphere Formation Assays

A tumorsphere is a solid, spherical formation developed from the proliferation of one cancer stem/progenitor cell. These tumorspheres (Figure 1a) are easily distinguishable from single or aggregated cells (Figure 1b) as the cells appear to become fused together and individual cells cannot be identified. Cells are grown in serum-free, non-adherent conditions in order to enrich the cancer stem/progenitor cell population as only cancer stem/progenitor cells can survive and proliferate in this environment. This assay can be used to estimate the percentage of cancer stem/progenitor cells present in a population of tumor cells. The size, which can vary from less than 50 micrometers to 250 micrometers, and number of tumorspheres formed can be used to characterize the cancer stem/progenitor cell population within a population of in vitro cultured cancer cells and within in vivo tumors (Lo et al., 2012; Liu et al., 2009). While several cell lines can be used for tumorsphere formation assay (e.g. primary mammary tumor cells from Her2/neu-transgenic mice, MCF7, BT474 and HCC1954), some cell lines may not form typical tumorsphere structures and may be difficult to count or classify definitively as tumorspheres.
Who Owns Work Product

This article addresses scenarios in which a lawyer and client might disagree about the potential disclosure of attorney work product. The recent Restatement of the Law Governing Lawyers takes the emphatic position that work product is the client's to waive, or not, entirely at the client's discretion. The Restatement barely acknowledges the position several jurisdictions have taken, at the other extreme, that the work product privilege is designed to protect the ability of lawyers to operate freely and therefore belongs to the lawyer who produced it. The article explores the issue of who has, or who should have, the power to control or waive the work product privilege. Case law has thoroughly identified and vetted the theoretical justifications for the privilege itself. But, as in many other areas of the law, scant attention has been paid to the theoretical justifications for waiver. The failure of scholars, courts, and rulemakers to distinguish issues regarding control of the privilege from the substantive underpinnings for the privilege has led to rules that are both simplistic and inadequate. The article sets forth five possible theoretical approaches to delineating an appropriate control and waiver principle, some reconcilable only with the Restatement rule, others with the contrary position. It then highlights the ways in which the existing rules mesh with, and diverge from, the alternative theories and identifies a series of situations in which the choice of rule becomes significant. The article illustrates why blind application of either extreme approach fails to account for important considerations underlying the work-product principle. The article therefore proposes an alternative approach that more directly serves the reasons why work product privilege developed.
Lower Jaw and Dentition of the Hemphillian Bear, Agriotherium (Ursidae), with the Description of a New Species

Agriotherium is known in North America only from middle to late Hemphillian age deposits. The permanent molars of Agriotherium were retained in the jaw until the animal reached full size, and then erupted simultaneously or in swift sequence. In Ursus the first molar erupts when the cub is scarcely old enough to leave the den, and the second and third molars in sequence thereafter. The premasseteric fossa separates Agriotherium from Indarctos and Ursus but is shared by modern to Pleistocene Tremarctos and Arctodus . The lower permanent dentition of Agriotherium has a reduced premolar pattern: P1 is present, P2 is absent, P3 is present in middle Hemphillian A. coffeyi as a two-rooted tooth but absent in the late Hemphillian A. schneiden Sellards. A. gregoryi (Frick) is poorly characterized and may be a synonym of A. schneiden. Agriotherium is not closely related to Indarctos . No known species of Agriotherium appears to have been ancestral to Arctodus or Tremarctos .
Automated Simultaneous Leukocyte Counting and Hemoglobin Determinations Using the Coulter Counter and the AutoAnalyzer

The standard (Model A) Coulter Counter has been automated for counting leukocytes by presenting it with blood specimens processed by a modified Technicon AutoAnalyzer manifold and Sampler II. An interference-free counting chamber allows each sample to be aspirated and counted in duplicate. The results are printed automatically. The overall process is controlled by a solid state electronic device. The samples can be simultaneously analyzed for hemoglobin by a standard automated cyanmethemoglobin method. Cell sedimentation is prevented by simultaneous magnetic stirring of as many as 40 blood samples, without cross-contamination. This device is capable of counting 30 separate specimens per hour after initial priming. The new device costs significantly less than other automated instruments performing similar functions.
Seismic Data Compression And Regularization Via Wave Packets

Seismic data compression and regularization are crucial, faced with large data volumes and incomplete data measurements in the oil industry. In this research, we present a comprehensive method of utilizing wave packets to perform seismic data compression and regularization. Wave packets, which can be regarded as symmetric “curvelets”, are viewed as optimally localized plane waves. With its intrinsic multi-scale and multiazimuth properties, we show that wave packet achieves a high compression rate for a sparse representation of seismic data volume. Besides, we demonstrate that via an iterative thresholding algorithm, irregular data can be regularized in wave packet domain without creating artifacts or losing original dipdependent information. Compared with regularization methods based on τ − p transform and wave atom transform, wave packet achieves the best result, demonstrated by some numerical examples.
Anxiety and attribution as predictors of non-completion of a course.

16 non-persisters in an individualized mastery approach of introductory psychology in a community college had significantly higher initial state anxiety than 26 persisters, but there was no signifi...
Compact Laser Source for Metal Deposition

For the past few years, there has been considerable interest in using lasers for the directed deposition of metal [1,2,3,4]. Part of this interest is driven by technological applications in microelectronics. In particular, this includes the rapid interconnection of gate arrays [5] and the repair of defects in photomasks [6]. The techniques used for the laser patterning of metal include Laser Chemical Vapor Deposition (LCVD) [7], and the decomposition of spin-coated organometallic inks [8]. In the first process, LCVD, a laser with a power of several hundred milliwatts or more is used to irradiate a substrate in the presence of an organometallic vapor. The substrate is chosen so that it absorbs the the incident laser radiation while, in general, the organometallic vapor is transparent at the laser wavelength. The absorption of the laser energy by the substrate results in a temperature rise which depends on the thermal properties of the substrate. If the temperature rise is sufficient, organometallic molecules impinging on the irradiated area decompose. Non-volatile components (such as metal fragments) remain on the surface and form a deposit. In the second process, decomposition of organometallic films, a substrate which was previously spin coated with an organometallic ink is irradiated wherever metal patterns are desired. The ink decomposes in these areas leaving a film of metal. The unirradiated areas of the ink are then washed away with a suitable solvent. Such processes have been extensively studied and developed using primarily argon, krypton, and CO 2 lasers [1,2,3,4]. In general these lasers are large, expensive, require maintenance, and raise reliability concerns. These characteristics add to the challenge of introducing laser deposition processes into the manufacturing environment.
Mortality Costs in Retail Trades

THE business man of today is increasingly concerned with an economic philosophy which was almost unheard of fifteen or twenty years ago. Perhaps best expressed in recent publications of the Brookings Institution,1 this philosophy embodies the idea that America's capacity to consume is far beyond present consumption; that productive facilities are waiting to be extended for the satisfaction of this capacity to consume, with the result that unemployment as a problem will virtually disappear. The crux of the whole problem lies in directing into the hands of the mass of people sufficient purchasing power to command the use of our productive capacity to its fullest extent. Purchasing power is determined as much by the prices of commodities and services as by the amount of the money income. Prices, in turn, are the resultant of a number of factors, but inherent in every price is the element of cost. These costs are both direct and indirect. In the hope that the results would throw some light upon those costs arising out of high mortality in the retail trades, a study was made of approximately ten thousand cases in the City of Pittsburgh for the period 1925 to 1934 inclusive. Some of the costs involved are most important in price determination, others are factors in establishing profit differentials but all have their effect in limiting total consumer purchasing power. Relatively little has been done to analyze business mortality. However, several studies dealing with mortality in retail trades are worthy of mention. One of the first is that of Paul Nystrom, covering a period from
DEMOLITION OF TWO SHELL STRUCTURE COOLING TOWERS BY CONTROLLED BLASTING

Two 69m high cooling towers with bottom diameter 56.75m under complicated circumstances were demolished successfully by controlled blasting.The cooling towers were hyperbolic thin-walled shell structures which were made of reinforced concrete precast slabs.Blasting scheme was designed elaborately,blasting cut and blasting parameters were chosen reasonably,no electric compound blasting network which combined cross connection with group units was adopted,and blasting safety check and security protective measures were strengthen.A good effect of blasting was achieved.
The Impact of Estimation Error on Latent Factor Model Forecasts of Portfolio Risk

In this article, the authors measure the impact of estimation error on latent factor model forecasts of portfolio risk and factor exposures. In markets simulated with a Gaussian return-generating process, the authors measure errors in forecasts for equally weighted and long-only minimum-variance portfolios constructed from a universe of 500 securities. They find that an estimation period of 250 days may be adequate to accurately forecast risk and factor exposures for an equally weighted portfolio. In contrast, the risk of a long-only minimum-variance portfolio is substantially underforecasted, even with an estimation period of 1,000 days. This underscores the importance of testing risk models on optimized portfolios.
Colloidal processing of polymer ceramic nanocomposites for integral capacitors

Polymer ceramic composites form a suitable material system for low temperature fabrication of embedded capacitors appropriate for the MCM-L technology. Improved electrical properties such as permittivity can be achieved by efficient filling of polymers with high dielectric constant ceramic powders such as lead magnesium niobate-lead titanate (PMN-PT) and barium titanate (BT). Photodefinable epoxies as the matrix polymer allow fine feature definition of the capacitor elements by conventional lithography techniques. The optimum weight percent of dispersant is tuned by monitoring the viscosity of the suspension. The dispersion mechanism (steric and electrostatic contribution) in a slightly polar solvent such as propylene glycol methyl ether acetate (PGMEA) is investigated from electrophoretic measurements. A high positive zeta potential is observed in the suspension, which suggests a strong contribution of electrostatic stabilization. By optimizing the particle packing using a bimodal distribution and modified processing methodology, a dielectric constant greater than 135 was achieved in PMN-PT/epoxy system. Suspensions are made with the lowest PGMEA content to ensure the efficiency of the dispersion and efficient particle packing in the dried film. Improved colloidal processing of nanoparticle-filled epoxy is a promising method to obtain ultra-thin capacitor films (<2/spl mu/m) with high capacitance density and improved yield. Capacitance of 35 nF/cm/sup 2/ was achieved with the thinnest films (2.5-3.0 /spl mu/m).
Strategic directions in computer security research

As a society we are becoming ever more dependent on computing and communications technologies. Yet the technologies we are using are fragile. We need to develop technologies for a robust and secure information infrastructure. These technologies should be affordable, verifiable, and scalable. In addition to fundamentally new technologies, we also need to develop strategies for strengthening legacy systems that form part of the critical information infrastructure.
The Last Hindu Emperor: Prithviraj Chauhan and the Indian Past, 1200-2000

This fascinating new study traces traditions and memories relating to the twelfth-century Indian ruler Prithviraj Chauhan; a Hindu king who was defeated and overthrown during the conquest of Northern India by Muslim armies from Afghanistan. Surveying a wealth of narratives that span more than 800 years, Cynthia Talbot explores the reasons why he is remembered, and by whom. In modern times, the Chauhan king has been referred to as 'the last Hindu emperor', because Muslim rule prevailed for centuries following his defeat. Despite being overthrown, however, his name and story have evolved over time into a historical symbol of India's martial valor. The Last Hindu Emperor sheds new light on the enduring importance of heroic histories in Indian culture and the extraordinary ability of historical memory to transform the hero of a clan into the hero of a community, and finally a nation.
Models for Sustainability

As one of the major methodologies used in the modeling of sustainability, Life Cycle Assessment (LCA) is widely used to evaluate the environmental impacts of emerging technologies and to enhance decision making towards sustainable development. However, most of the current LCA models are static and deterministic. More insights could be generated when LCA models are coupled with higher-resolution techniques in a prospective fashion. Instead of trying to accurately predict the future, the purpose and value of integrated prospective models are to explore the boundaries of possibility and to shed light on directions that can lead to sustainable pathways. The biggest challenge is to determine the appropriate model resolution so that both big-picture insights and critical details are included. This challenge is hard to address, especially for interdisciplinary models that try to incorporate more than one dimension related to sustainability. However, improvements can be made continually through efforts from a growing population of interdisciplinary researchers.
Unusual features of ethylene copolymerization reactions with binary metallocene catalysts

ABSTRACTEthylene/1-hexene copolymers produced with MAO-activated binary metallocene catalysts, such as combinations Cp2ZrCl2 + (Me5Cp)2ZrCl2, (Ind-H4)2ZrCl2 + (Me5Cp)2ZrCl2, Cp2ZrCl2 + Cp2TiCl2, etc., contain three types of components. Two of the components can be attributed to active centers derived from each individual metallocene complex, and one or two materials are produced with different types of active center. Some of the binary catalysts generate the three components in comparable proportions, whereas other catalysts produce copolymers with one dominant component, which does not resemble the copolymers produced with the individual complexes. A mechanism is proposed for the formation of the “new” copolymer materials.
Synthetically engineered microbes reveal interesting principles of cooperation

Cooperation is ubiquitous in biological systems. However, if natural selection favors traits that confer an advantage to one individual over another, then helping others would be paradoxical. Nevertheless, cooperation persists and is critical in maintaining homeostasis in systems ranging from populations of bacteria to groupings of mammals. Developing an understanding of the dynamics and mechanisms by which cooperation operates is critical in understanding ecological and evolutionary relationships. Over the past decade, synthetic biology has emerged as a powerful tool to study social dynamics. By engineering rationally controlled and modulatable behavior into microbes, we have increased our overall understanding of how cooperation enhances, or conversely constrains, populations. Furthermore, it has increased our understanding of how cooperation is maintained within populations, which may provide a useful framework to influence populations by altering cooperation. As many bacterial pathogens require cooperation to infect the host and survive, the principles developed using synthetic biology offer promise of developing novel tools and strategies to treat infections, which may reduce the use of antimicrobial agents. Overall, the use of engineered cooperative microbes has allowed the field to verify existing, and develop novel, theories that may govern cooperative behaviors at all levels of biology.
Learning to notice important student mathematical thinking in complex classroom interactions

Abstract Noticing students' mathematical thinking is a key element of effective instruction, but novice teachers do not naturally engage in this practice. Prospective secondary school mathematics teachers were engaged in an intervention grounded in analysis of minimally edited video from local secondary school mathematics classrooms; the goal was to support their ability to notice important student thinking within the complexity of instruction. Evidence of participants' learning in five iterations of the intervention is discussed, including their focus on student mathematical thinking, their ability to discuss the mathematics in that thinking, and their ability to notice particular high-leverage instances of student thinking.
Implications from distinct sulfate-reducing bacteria populations between cattle manure and digestate in the elucidation of H2S production during anaerobic digestion of animal slurry.

Biogas produced from the anaerobic digestion of animal slurry consists mainly of methane (CH4) and carbon dioxide (CO2), but also includes other minor gases, such as hydrogen sulfide (H2S). Since it can act as a potent corrosive agent and presents a health hazard even at low concentrations, H2S is considered an undesirable by-product of anaerobic digestion. Sulfate-reducing bacteria (SRBs) have been identified as the main biological source of H2S in a number of natural, biological, and human-made habitats, and thus represent likely candidate microorganisms responsible for the production of H2S in anaerobic manure digesters. Phylogenetically, SRBs form a divergent group of bacteria that share a common anaerobic respiration pathway that allows them to use sulfate as a terminal electron acceptor. While the composition and activity of SRBs have been well documented in other environments, their metabolic potential remains largely uncharacterized and their populations poorly defined in anaerobic manure digesters. In this context, a combination of in vitro culture-based studies and DNA-based approaches, respectively, were used to gain further insight. Unexpectedly, only low to nondetectable levels of H2S were produced by digestate collected from a manure biogas plant documented to have persistently high concentrations of H2S in its biogas (2000-3000 ppm). In contrast, combining digestate with untreated manure (a substrate with comparatively lower sulfate and SRB cell densities than digestate) was found to produce elevated H2S levels in culture. While a 16S rRNA gene-based community composition approach did not reveal likely candidate SRBs in digestate or untreated manure, the use of the dsrAB gene as a phylogenetic marker provided more insight. In digestate, the predominant SRBs were found to be uncharacterized species likely belonging to the genus Desulfosporosinus (Peptococcaceae, Clostridiales, Firmicutes), while Desulfovibrio-related SRBs (Desulfovibrionaceae, Desulfovibrionales, Proteobacteria) were the most highly represented in untreated manure. Intriguingly, the same species-level OTUs with a similar pattern of opposite relative abundance were also found in two other digesters with lower H2S levels in their biogas. Together, our results suggest that elevated H2S production in anaerobic digesters requires the combination of biological and nutritional factors from both untreated manure and digestate.
Rapid and high throughput fabrication of high temperature stable structures through PDMS transfer printing

We report on a facile and low cost fabrication approach for structures—gratings and enclosed nanochannels, through simple solution processed chemistries in conjunction with nanotransfer printing techniques. The ink formulation primarily consisting of an organosilicate polymeric network with a small percentage of added 3-aminopropyl triethoxysilane crosslinker allows one to obtain robust structures that are not only stable towards high temperature processing steps as high as 550 °C but also exhibit exceptional stability against a host of organic solvent washes. No discernable structure distortion was observed compared to the as-printed structures (room temperature processed) when printed structures were subjected to temperatures as high as 550 °C. We further demonstrate the applicability of this technique towards the fabrication of more complex nanostructures such as enclosed channels through a double transfer method, leveraging the exceptional room temperature cross-linking ability of the printed structures and their subsequent resistance to dissolution in organic solvent washes. The exceptional temperature and physico-chemical stability of the nanotransfer printed structures makes this a useful fabrication tool that may be applied as is, or integrated with conventional lithographic techniques for the large area fabrication of functional nanostructures and devices.
Parenting the Dispossessed: Raising the Children of “Stop, Question, and Frisk”

In the early 2000s, the New York City Police Department implemented policies that called for the aggressive use of “Stop, Question, and Frisk,” in neighborhoods deemed “high crime.” Drawing from ap...
Smartphone chloridometer for point-of-care applications

Chloride level in sweat is a major diagnostic criterion for cystic fibrosis (CF) and many other health conditions. In an effort to develop a low cost, point-of-care sweat diagnostics system for chloride concentration measurement, we demonstrated a smartphone-based chloridometer to measure sweat chloride by using our recently developed fluorescence chloride sensor. We characterized the performance of our device to validate its clinical potential. The study indicates that our smartphone-based chloridometer may potentially advance the point-of-care diagnostic system by reducing cost and improving diagnostic accuracy.
Dysregulation of the autophagic-lysosomal pathway in Gaucher and Parkinson's disease

The finding that mutations in the Gaucher's Disease (GD) gene GBA1 are a strong risk factor for Parkinson's Disease (PD) has allowed for unique insights into pathophysiology centered on disruption of the autophagic-lysosomal pathway. Protein aggregations in the form of Lewy bodies and the effects of canonical PD mutations that converge on the lysosomal degradation system suggest that neurodegeneration in PD is mediated by dysregulation of protein homeostasis. The well-characterized clinical and pathological relationship between PD and the lysosomal storage disorder GD emphasizes the importance of dysregulated protein metabolism in neurodegeneration, and one intriguing piece of this relationship is a shared phenotype of autophagic-lysosomal dysfunction in both diseases. Translational application of these findings may be accelerated by the use of midbrain dopamine neuronal models derived from induced pluripotent stem cells (iPSCs) that recapitulate several pathological features of GD and PD. In this review, we discuss evidence linking autophagic dysfunction to the pathophysiology of GD and GBA1-linked parkinsonism and focus more specifically on studies performed recently in iPSC-derived neurons.
Is ST segment elevation non–Q- wave myocardial infarction after thrombolytic therapy a new clinical entity that requires an invasive management strategy?∗

The Veterans Affairs Non–Q-Wave Infarction Strategies in Hospital (VANQWISH) trial compared a strategy of early diagnostic coronary angiography (followed by revascularization, if necessary) to a conservative ischemia-guided approach (for spontaneous or inducible ischemia) in 920 patients with
Survey of Illinois Law: Stepparent Childcare

In Illinois, the “liberty interests of parents” are reflected in the “superior rights doctrine,” which holds, as elsewhere, that parents have superior rights regarding the care of their children. This doctrine is necessitated by U.S. Supreme Court decisions, including Troxel v. Granville in 2000. The superior rights doctrine is incorporated into some Illinois statutes, as when childcare may be afforded to a nonparent “only if” the child “is not in the physical custody” of a parent and as when “reasonable visitation privileges” may only be afforded a stepparent who has lived with the child for at least five years. The Illinois superior rights doctrine was employed in 2012 to deny childcare opportunities to a former stepfather over maternal objection in the case of In re Marriage of Mancine. There, the stepfather allegedly assumed, with the mother, “a caregiving role over a significant period of time.” There was an explicit rejection of the de facto parent doctrine. In reviewing Troxel and Mancine, as well as other American state precedents, this article urges broader stepparent childcare opportunities be recognized in Illinois, especially where there is only one parent under law. It prefers expansion via new special statutes on stepparents, but recognizes expansion could also come via new general statutes expanding the definitions of legal parenthood or of those nonparents who are eligible to seek childcare. Without imminent General Assembly action, the article urges incremental common law expansions of stepparent childcare opportunities in Illinois.
The Iron Chelator L1 Potentiates Oxidative DNA Damage in Iron-Loaded Liver Cells

Iron-mediated carcinogenesis is thought to occur through the generation of oxygen radicals. Iron chelators are used in attempts to prevent the long term consequences of iron overload. In particular, 1,2-dimethyl-3-hydroxypyrid-4-one (L1), has shown promise as an effective chelator. Using an established hepatocellular model of iron overload, we studied the generation of iron-catalyzed oxidative DNA damage and the influence of iron chelators, including L1, on such damage. Iron loading of HepG2 cells was found to greatly exacerbate hydrogen peroxide-mediated DNA damage. Desferrithiocin was protective against iron/hydrogen peroxide-induced DNA damage; deferoxamine had no effect. In contrast, L1 exposure markedly potentiated hydrogen peroxide-mediated oxidative DNA damage in iron-loaded liver cells. However, when exposure to L1 was maintained during incubation with hydrogen peroxide, L1 exerted a protective effect. We interpret this as indicating that L1's potential toxicity is highly dependent on the L1:iron ratio. In vitro studies examining iron-mediated ascorbate oxidation in the presence of L1 showed that an L1:iron ratio must be at least 3 to 1 for L1 to inhibit the generation of free radicals; at lower concentrations of L1 increased oxygen radical generation occurs. In the clinical setting, such potentiation of iron-catalyzed oxidative DNA damage at low L1:iron ratios may lead to long-term toxicities that might preclude administration of L1 as an iron chelator. Whether this implication in fact extends to the in vivo situation will have to be verified in animal studies.
A High-Capacity Annular Centrifugal Contactor

A centrifugal contactor of unique design has been developed for solvent extraction processing of high-plutonium-content fuels. The unit has a vertically suspended rotor that has a 4-in. inside diam...
Sediment control on subduction plate speeds

Abstract Tectonic plate velocities predominantly result from a balance between the potential energy change of the subducting slab and viscous dissipation in the mantle, bending lithosphere, and slab–upper plate interface. A range of observations suggest that slabs may be weak, implying a more prominent role for plate interface dissipation than previously thought. The shallow thrust interface is commonly assumed to be weak due to an abundance of fluids and near-lithostatic pore fluid pressures, but little attention has been paid to the influence of the deeper, viscous interface. Here we show that the deep interface viscosity in subduction zones is strongly affected by the relative proportions of sedimentary to mafic rocks that are subducted to depth. Where sediments on the down-going plate are sparse, the deep interface is dominated by mafic lithologies that metamorphose to eclogites, which exhibit viscosities 1–2 orders of magnitude higher than the asthenospheric mantle, and reduce subduction plate speeds. In contrast, where sediments are abundant and subducted to depth, the deep interface viscosity is 1–2 orders of magnitude lower than the asthenospheric mantle, thus allowing significantly faster plate velocities. This correlation between subduction plate speed and deep sediment subduction may help explain dramatic accelerations (or decelerations) in convergence rates, such as the acceleration documented for India–Asia convergence during the mid-Cenozoic.
Free Software without a Free Lunch or Free Beer

Economists like to say that there are no free lunches. How does that attitude apply to free software and services?
Imperative Instruction for Pressurized Metered-Dose Inhalers: Provider Perspectives.

BACKGROUND: Reports show that many patients do not use their pressurized metered-dose inhalers (pMDIs) effectively. The National Heart, Lung, and Blood Institute recommends that health-care providers educate and assess patients9 pMDI technique at each opportunity. However, limited data exist regarding how often pediatric primary care providers perform assessments and which methods they use. We sought to (1) identify instructional methods used to teach pMDI use, (2) describe how pMDI use is reassessed at follow-up visits, and (3) describe primary care provider attitudes and barriers to in-office pMDI instruction. METHODS: A 34-item electronic survey was distributed from August to December 2016 via E-mail to local pediatric primary care providers. Descriptive statistics were used for analysis. RESULTS: Sixty two of 223 potential primary care providers (28%) responded. Physicians and nurse practitioners were identified most often as the providers of pMDI education (53%). When first prescribing a pMDI, only 10% reported having the patient practice inhaler use in the office and receive feedback. Only 19% “always” reassessed the technique, even for patients with poorly controlled asthma. Among those who reassessed the technique, most (76%) did so verbally, and only 42% asked the patients to demonstrate pMDI use. Only 32% reported that typical patient education in their setting was adequate to ensure proper pMDI use. Commonly cited barriers included time (84%) and access to demo pMDIs (67%). Provider solutions included video tutorials and access to demo inhalers. CONCLUSIONS: Many pediatric primary care providers did not demonstrate or have patients practice pMDI use when teaching or assessing pMDI technique, and the reassessment rate was low even for patients with poorly controlled asthma. Identifying and training a consistent pMDI educator and obtaining demo pMDIs may abate some barriers. Respiratory therapists could appropriately fulfill this educator role. Brief, repeated pMDI practice for motor learning could promote more stable pMDI mastery.