cssi/SciSciGPT-SciSciNet huggingface dataset:
Storied identities and teacher candidates’ developing practices

While many studies have investigated the relationship between teachers’ identity work and developing practice, few have examined teacher candidates’ developing practice through a storied identity lens. Drawing upon narrative inquiry methodology and a storied identity analytic framework, I examined how the storied identities of learning science, choosing to become a science teacher, and becoming a science teacher shaped teacher candidates’ learning to teach. In particular, I examined the stories of two interns by focusing on their experiences as science learners, and transitions to becoming science teachers. Also, I examined the influence and implications of their identity on their instructional practice while learning to teach. This study suggests that a storied identity lens can provide a better understanding of the different practices that teachers enact under the same teaching context. The results have implications for teacher education programs to consider providing more opportunities for beginning teachers to tell their stories of science learning and learning to teach, and to be aware of how the social cultural context plays a role in shaping teachers’ practice.
Physicians Who Disseminate Medical Misinformation: Testing the Constitutional Limits of Professional Disciplinary Action

There have been increasing calls in the medical community for revoking the licenses of physicians who disseminate medical misinformation, such as false claims about the safety of vaccines or the effectiveness of nonpharmaceutical measures to prevent COVID-19. While no licensing board has yet imposed penalties on physicians for disseminating medical misinformation, there is evidence that boards are using the threat of disciplinary action to exert pressure on physicians who make public statements that conflict with professional standards of care. This Essay argues that, in most cases, imposing disciplinary penalties on physicians for speech that takes place outside a physician-patient relationship would have dangerous policy implications and would almost certainly be unconstitutional. However, drawing on examples from the regulation of the legal profession, it argues that disciplinary actions would be appropriate under one set of circumstances: if a board can establish that a physician has disseminated information that she knows to be false or with reckless disregard as to whether it is true—i.e., with the “actual malice” standard applied to defamation cases brought by public officials and public figures. The Essay considers the implications of this standard for different factual scenarios.
Understanding long-term (1982–2013) multi-decadal change in the equatorial and subtropical South Atlantic climate

High-resolution observations along with atmospheric and oceanic reanalyses are diagnosed to understand how and why southeastern Atlantic SSTs have changed over the 1982–2013 period. Multiple datasets are used to evaluate confidence. Results indicate significant SST warming trends (0.5–1.5 K per 32-years) along the Guinean and Angolan/Namibian Coasts, and a cooling trend (−0.10 to −0.60 K per 32-years) over the subtropical South Atlantic between 18°S and 28°S. SST trends are shown to vary over the annual cycle with the greatest changes occurring during November–January. Analysis of the ocean surface heat balance reveals that the austral summer SST warming trend along the Angolan/Namibian Coast is associated with an increase in the net downward atmospheric heat flux. In addition, there is a decrease in coastal upwelling due to circulation changes related to a poleward shift of the South Atlantic subtropical anticyclone and an intensification of the southwestern African thermal low. The cooling trend over the subtropical South Atlantic is also associated with the poleward shift of the South Atlantic anticyclone, as stronger surface winds enhance latent heat loss from the ocean over this region. Positive SST trends along the Guinean coast are found to be primarily associated with changes internal to the ocean, specifically, reduced coastal upwelling, diffusion, and enhanced horizontal transport of warmer water. These results highlight the need to better understand South Atlantic subtropical anticyclone and the continental thermal low interactions and their implications for present day climate variability and future climate change.
Simultaneous Detection of Multiplex-Amplified Human Immunodeficiency Virus Type 1 RNA, Hepatitis C Virus RNA, and Hepatitis B Virus DNA Using a Flow Cytometer Microsphere-Based Hybridization Assay

The feasibility of performing a multiplex assay for the detection of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) RNAs and hepatitis B virus (HBV) DNA is demonstrated. This assay is based (i) on the coamplification of a 142-bp fragment from the gag region of the HIV-1 genome and a 142-bp HIV-1 quantitation standard fragment, a 244-bp fragment from the 5' noncoding region of the HCV genome, and a 104-bp fragment from the pre-C and C gene regions of the HBV genome, using three sets of specific primers; (ii) on the capacity of these four biotinylated PCR products to hybridize to their specific oligonucleotide probe-coated microspheres; and (iii) on the ability of the flow cytometer to discriminate between distinct fluorescent-microsphere categories. Absence of cross-hybridization between the unrelated oligonucleotide probes and PCR products generated by the multiplex reverse transcription-PCR (RT-PCR) and the highly sensitive detection method allowed us to assess unambiguously the HIV-1 viral load and the infectious status of 35 serologically well-established clinical samples and 20 seronegative blood donor plasma samples tested. The results indicate that multiplex RT-PCR and flow cytometer microsphere-based hybridization assays, when combined, provide a rapid, sensitive, and specific method for the quantitation and detection of the major viral agents of infectious diseases in a single plasma sample.
Understanding of the effectiveness of diesel fuel flow improvers

The diesel fuel cold filterability test has been developed to predict fuel filter plugging by diesel fuels containing flow improver additives, and to understand how flow improvers interact with diesel fuels to affect low-temperature operation of diesel vehicles. Mechanisms are proposed to explain the effectiveness of flow improvers on the basis of these factors. 19 refs.
Orexin A in the ventrolateral preoptic area increases feeding and spontaneous physical activity (1126.1)

The brain regulates behaviors influencing energy balance such as arousal, feeding and spontaneous physical activity (SPA), which is all activity excluding formal exercise yet mechanisms are unclear...
Dr. Powell Replies

Our original design in planning this study was to assess three areas: (1) the efficacy of nasoduodenal tube feeding as a technique of providing adequate caloric intake to the very-low-birth-weight infant, (2) the efficiency of these calories in promoting weight gain, (3) the complication rate of this feeding method. To answer our first two questions, we chose the most rigorous control available to us, which was nasogastric continuous drip feeding, rather than the standard gavage,
Early and Profound Human Impact

Plows, Plagues, and Petroleum . How Humans Took Control of Climate. By William F. Ruddiman . Princeton University Press, Princeton, NJ, 2005. 216 pp. $24.95, £15.95. ISBN 0-691-12164-8. The author argues for his controversial thesis that preindustrial human societies--through their release of carbon dioxide and methane--changed Earth's climate to the extent that a minor glaciation was averted.
Do the Benefits of Fixed Exchange Rates Outweigh Their Costs? The Franc Zone in Africa

A primary reason for structural adjustment in agriculture is the wide fluctuation in the world prices of agricultural commodities, which causes sharp swings in the terms of trade of countries that rely on these commodities for their export earnings. A key instrument in structural adjustment is the exchange rate. How, and whether, this instrument is used, however, depends on the ‘rules of the game’ – that is, the particular exchange rate regime the country is in. This paper addresses the question of how small, open economies that are subject to sharp swings in their terms of trade should select an appropriate exchange rate regime. We develop a framework to clarify the trade-offs involved, and apply it to the CFA Zone countries in Africa, which have maintained a fixed parity with the French franc since independence. Thanks to the predominance of a few agricultural products and natural resources in their exports, CFA member countries have suffered frequent shocks in their terms of trade. A flexible exchange rate could have possibly alleviated some of the output costs of these external shocks. On the other hand, a fixed exchange rate has enabled these countries to maintain lower inflation levels than their neighbours. Our framework provides a way of weighing these costs and benefits. Using our model as a guide, we investigate whether their choice of a fixed exchange rate was (and remains) a wise one.
The Origins of Status Hierarchies: A Formal Theory and Empirical Test

This article offers a formal theoretical model of the emergence of hierarchy that bridges the division between individualistic and structuralist accounts of inequality. In the model, actors reproduce status hierarchies by adjusting their own status‐conferring gestures according to collective attributions. These collective attributions are just the aggregate of individual gestures, leading to a self‐reinforcing status ranking. Winner‐take‐all hierarchies are discouraged, however, when people prefer reciprocation of their status‐conferring actions. The model therefore depicts a status ranking as an equilibrium resulting from individual responses to the trade‐off between social influence and the distaste for making unreciprocated gestures. Analysis of the model generates several precise predictions about the patterns that social networks should exhibit at equilibrium. Data on interaction in task groups, friendship ratings in a fraternity, and play in a set of infant quintuplets is used to show that the forma...
IBM alternate work schedules (AWS)

In early 1990, the IBM Microelectronics Division Semiconductor Manufacturing facility in Essex Junction, Vermont was operating eight-hour shifts around-the-clock. To reduce cost and fulfill an ever increasing demand for its products, it became imperative that this traditional three-shift operation be refocused to more efficiently maximize the use of the facility's physical assets and the effectiveness of its people. After studying the work schedules of numerous companies in the United States and Europe, it was determined that a 12-hour shift schedule would result in a significant reduction in overtime and increased productivity, both key goals of site management. To implement such a dramatic change of schedules, however, would require an in-depth understanding of its effect on employees and their families. To achieve such an understanding, manufacturing employees were asked to participate in round table discussions, opinion surveys and discussions with middle and first-level managers. Some of the areas examined were travel time to work, arrangements for child care, spousal work schedules, sleeping habits and the overall status of an individual's health. A pilot program was launched before actually changing schedules. Compensation adjustments were reviewed during this program to determine the most flexible and attractive approach for employees, one that: also contributed to overall savings for the corporation. This approach to compensation has been changed only once since its inception. During the first half of 1990, IBM's semiconductor fabricators began their migration to the 12-hour, alternate work schedules (AWS). Productivity improvements and overall benefits of an alternate work schedule relative to the IBM manufacturing community will also be reviewed.
Multi-path variational transition state theory for chiral molecules: the site-dependent kinetics for abstraction of hydrogen from 2-butanol by hydroperoxyl radical, analysis of hydrogen bonding in the transition state, and dramatic temperature dependence of the activation energy

The goal of the present work is modeling the kinetics of a key reaction involved in the combustion of the biofuel 2-butanol. To accomplish this we extended multi-path variational transition state theory (MP-VTST) with the small curvature tunneling (SCT) approximation to include multistructural anharmonicity factors for molecules with chiral carbons. We use the resulting theory to predict the site-dependent rate constants of the hydrogen abstraction from 2-butanol by hydroperoxyl radical. The generalized transmission coefficients were averaged over the four lowest-energy reaction paths. The computed forward reaction rate constants indicate that hydrogen abstraction from the C-2 site has the largest contribution to the overall reaction from 200 K to 2400 K, with a contribution ranging from 99.9988% at 200 K to 88.9% at 800 K to 21.2% at 3000 K, while hydrogen abstraction from the oxygen site makes the lowest contribution at all temperatures, ranging from 2.5 × 10−9% at 200 K to 0.65% at 800 K to 18% at 3000 K. This work highlights the importance of including the multiple-structure and torsional potential anharmonicity in the computation of the thermal rate constants. We also analyzed the role played by the hydrogen bond at the transition state, and we illustrated the risks of (a) considering only the lowest-energy conformations in the calculations of the rate constants or (b) ignoring the nonlinear temperature dependence of the activation energies. A hydrogen bond at the transition state can lower the enthalpy of activation, but raise the free energy of activation. We find an energy of activation that increases from 11 kcal mol−1 at 200 K to more than 36 kcal mol−1 at high temperature for this radical reaction with a biofuel molecule.
Cross-Examining the Defendant about Other Witnesses

This article examines United States v. Schmitz, 634 F.3d 1247 (11th Cir. 2011) to illustrate how a court addressed the fairness of singling out the testifying defendant for cross-examination about his/her belief that the government's witnesses are lying or not.
The MMP2 gene may be associated with longissimus dorsi muscle area in the pig (Sus scrofa).

The matrix metalloproteinase-2 gene (MMP2) was found to be associated with hip structure in pigs. Recently three quantitative trait loci (QTLs) for loin muscle area were found on chromosome 6, to whichMMP2 was mapped. In the present study, association analyses were conducted in two pig populations for a single-nucleotide polymorphism (SNP) c.-1959C>G present at a putative promoter region of theMMP2 gene. The association results showed that the animals with the C allele have a significantly larger loin muscle area than that of the animals with the G allele (P < 0.05). To confirm the present results, further functional studies and an additional causative SNP discovery in pigs with various genetic backgrounds are necessary.
A Unifying Formulation of Material Dispersion in Finite-Difference Time-Domain Simulations of Optical Problems

Methods of solving Maxwell’s equations on a discrete grid in space and time show promise in predicting the time-evolution of ultrashort pulse propagation in optical devices [1,2]. Finite-Difference Time-Domain (FDTD) algorithms developed for microwave problems [3,4] discretize Maxwell’s curl equations and consider the permittivity e and permeability μ of a material to be constant. Over the bandwidth of short optical pulses, the material dispersion cannot be ignored. Recently, various authors [5-11] have attempted to model this dispersion by adding finite-difference approximations of the constitutive equations to the algorithm. Two competing approaches with very different motivations have emerged; comparisons between them have been in the form of lengthy numerical simulations. We formulate the problem of modeling dispersive materials as a filter design problem in signal processing. The formalism of discrete-time linear systems then enables us to examine the difference equation as an approximation to the desired continuous filter, and to equate the design of an optimal filter to the solution of a constrained minimization problem. We show that the previously used methods of approximating dispersion are analogous to the matched and bilinear approximation methods of discrete filter design theory. We compare the exact frequency response of existing discretizations to the desired response for Debye and Lorentzian media.
Everything Unique or Unusual about Scale Insects (Homoptera: Coccoidae)

This Article is compiled from observations and research on selected literature about a fascinating insect group. Roughly 6,000 species of scale insects comprise the superfamily Coccoidae, also known in European literature as the suborder Coccinae. Some workers recognize 16 families, others up to 24. In this article, I use the terms “scale insects” or “coccoids” as synonyms referring to all members of Coccoidae. Because of a basic unfamiliarity with this group, the study of scale insects has often been neglected by biology and entomology departments at universities. Although some of the unusual features discussed here are not unique, scale insects combine so many of them that no other insect group compares.
RecA-mediated Achilles' heel cleavage

The specific protection of only one of many restriction sites in a genome from inactivation by a cognate methyltransferase (MTase) creates a unique cleavage site - an Achilles' heel cleavage (AC) site. In the RecA-AC, or RARE, technique, such specific protection is provided by a synaptic complex composed of RecA protein, a gamma-S analog of ATP and a 30-60 nucleotide long oligodeoxynucleotide complementary or identical to the sequence-targeted site in which the protected restriction site is embedded. Upon methylation and the subsequent removal of the protective complex and MTase, the protected site is the only site cut by the cognate restriction enzyme. Two such targeted cuts permit the excision of a unique DNA fragment from the genome. Recent advances include the calibration of DNA clones, the mapping of gaps, and the determination of the sizes of excised fragments by pulsed-field gel electrophoresis, which allows one to measure distances between any two neighboring sequence-targeted sites, in the range of a few kilobases to 10 megabases, with the purpose of physically mapping the genome.
Chemical weathering and landscape development in mid-latitude alpine environments

Abstract This paper attempts to assess the role of chemical processes in the weathering, erosion, and denudation of periglacial alpine environments. It draws primarily from detailed chemical studies in the alpine zones of the Colorado Rocky Mountains, the Jotunheimen of Norway, and northwest Swedish Lapland. The nature or kind of chemical weathering processes has been found to be the same in periglacial environments as elsewhere. Comparison of weathering rates among various environments reveals periglacial chemical weathering to be generally slower than that in the tropical and temperate latitudes, but overlapping with the lower values reported from such environments. In broad terms, this statement is valid whether assessment is based on bedrock or regolith weathering estimates. Chemical weathering is found to be a substantial, sometimes the dominant, agent of mass removal in periglacial environments. Assessment of the role of chemical processes in denudation is complicated by the differing, sometimes conflicting, definitions of the term. It is important to view chemical processes primarily as a component of geomorphic work, rather than as an important land-forming agent, in periglacial environments. Given the intrinsic attribute of long distance transport out of a drainage basin implicit to denudation, chemical solute loads in periglacial river systems must be ranked highly in comparison to the, often dramatic, but nearly always highly localized contribution from alpine mass wasting.
Historical biogeography of the widespread spider wasp tribe Aporini (Hymenoptera: Pompilidae)

Aim Our aim was to determine the age and area of origin of the genera of the Aporini tribe of spider wasps by studying its historical biogeography. We also tested the fit of several hypotheses concerning the processes underlying the widespread distribution of this group. Location The Holarctic and Neotropics. Methods A phylogeny of 44 Aporini taxa was produced through Bayesian inference using four nuclear molecular markers (elongation factor-1 α F2 copy, long-wavelength rhodopsin, wingless and the D2–D3 regions of the 28S ribosomal RNA). A lognormal relaxed molecular clock, calibrated with ages from three fossils, was used to estimate lineage divergence times. Biogeographical processes were studied using three methods: statistical dispersal–vicariance analysis (S-DIVA), dispersal–extinction cladogenesis (DEC) analysis and Bayesian binary Markov chain Monte Carlo (BBM) analysis. Results Our data suggest an origin for the most recent common ancestor of extant Aporini in the Nearctic region in the early Miocene, 22.6 Ma, with a confidence interval (CI) of 17.40–28.83 Ma. All genera originated in the Miocene, four in the Nearctic region. A constrained DEC analysis, where only dispersal to adjacent regions was allowed, produced the highest likelihood and was mostly congruent with the BBM results. Main conclusions Dispersal from the Nearctic region to the Palaearctic region probably occurred across the Bering land bridge in the early Miocene, 15–18 Ma (CI = 11.14, 23.52), while three dispersal events to South America from Mesoamerica took place independently. These dispersals to South America occurred after 18 Ma through the Isthmus of Panama or across the Panama seaway. Three independent over-water dispersal events to the Antilles occurred from Mesoamerica and the Nearctic for two Aporini genera. The patterns inferred within the biogeographical history of Aporini agree with several scenarios proposed for other unrelated taxa.
Peri‐implant soft‐tissue health surrounding cement‐ and screw‐retained implant restorations: a multi‐center, 3‐year prospective study

OBJECTIVE The purpose of this prospective clinical study was to evaluate peri-implant soft-tissue conditions and esthetic fulfillment during a 3-year follow-up period following prosthetic rehabilitation. MATERIAL AND METHODS As part of a prospective multi-center study, 152 ITI dental implants were placed in 80 patients in the maxillary anterior region. Fifty-nine crowns (38.82%) were cement retained, while 93 (61.18%) crowns were screw retained. At loading and 3, 6, 12 and 36 months post-loading, modified plaque index (MPI), sulcus bleeding index (SBI), keratinized mucosa (KM), gingival level (GL), and esthetic fulfillment were recorded. RESULTS All patients completed the study and no complications were reported. While statistically not significant at all time points, cement-retained crowns seemed to present a worsening trend in MPI and SBI scores. Interestingly, screw-retained crowns seemed to present an opposite picture, their MPI and SBI scores improved over time. While plaque accumulation, prophylaxis and depth of crown margin significantly affected levels of sulcus bleeding, prophylaxis alone played a key role in reducing plaque accumulation. No soft tissue recession was observed in either cement- or screw-retained crowns up to 3 years post-loading. Esthetic fulfillment survey revealed that patients did not have a preference for crown types; however, dentists favored cement-retained over screw-retained crowns. CONCLUSIONS Peri-implant soft tissues responded more favorably to screw-retained crowns when compared with cement-retained crowns. However, no soft-tissue recession was observed in either type of crowns. Cement-retained crowns were preferred by dentists, while patients were equally satisfied with either type of crowns they received.
Dolomitization, Dolomite Distribution, Reservoir Rocks: ABSTRACT

Approximately 80% of the hydrocarbon reserves in carbonate rocks in North America are found in rock that is essentially pure dolomite. In many reservoirs the field limits are determined by the distribution of dolomite, because the dolomitization process is conducive to the production of a favorable reservoir rock. The distribution of dolomite may be determined by (1) those rocks that were within the flow path of a dolomitizing fluid (water-controlled dolomitization) and (2) the susceptibility of a rock within the flow path of a dolomitizing fluid to dolomitization (rock-controlled dolomitization). The second factor may be controlled by permeability at the time of dolomitization, particle size, or solubility of the original particles. The identification of the cause of the location of an individual dolomite body is significant to understanding its size and distribution. Paleozoic carbonate rocks containing abundant crinoids commonly illustrate the idea of rock-control dolomitization. The significant parameter appears to be the original fabric of the sediment and is related to the ratio of carbonate mud to carbonate sand-size grains. The hydrology of hypersaline brine on Bonaire in the Netherlands Antilles provides a model from the Holocene that illustrates water-controlled dolomitization. In this model, access to hypersaline brine determines whether a sediment or rock will have the opportunity for dolomitization. End_of_Article - Last_Page 862------------
615 EGF-MEDIATED BREAST MILK-ENHANCED INTESTINAL GROWTH IN NEONATAL RATS

We recently showed that newborn rats handfed rat breast milk for 40 hours demonstrated greater intestinal growth than animals handfed an isocaloric formula. (Clin Res 31: A132, 1983) It was postulated that Epidermal Growth Factor (EGF) present in rat breast milk may be partly responsible for mediating this trophic response. 87 neonatal rats who never suckled were fed artificial formula containing 0, 1.2, 3.0, or 6.0 mcg/ml EGF for 40 hours. All 4 groups of rats gained weight by 40 hours, but there were no differences in whole body weight among the groups. Animals fed 3.0 and 6.0 mcg/ml of EGF-supplemented formula had significantly heavier whole intestines (p<.05 and p<.01, respectively); however, there were no significant differences in stomach or liver weight. Rats fed formula containing 3.0 and 6.0 mcg/ml EGF demonstrated significantly greater incorporation of 3H Thymidine into DNA in the proximal (p<.01) and distal bowel (p<.01) compared to animals fed 0 EGF. Additionally, animals fed 3.0 and 6.0 mcg/ml EGF had greater intestinal DNA content (p<.05).
A MODEL FOR THE ENZYME-SUBSTRATE COMPLEX OF DNA PHOTOLYASE AND PHOTODAMAGED DNA

The three-dimensional structure of Escherichia coli DNA photolyase and molecular dynamics simulations using the AMBER force field were used to construct a model of the enzyme−substrate complex. Three different dinucleotides with cyclobutane pyrimidine dimers (T T, T U, and U T), two conformations of a single-stranded DNA nonamer, and a duplex DNA dodecamer containing the T T lesion were studied. The results are in good agreement with available experimental data and provide a structural rationalization for the results of ethylation studies, the measurement of the relative rates of electron transfer for different dinucleotides complexed to the enzyme, and the similar binding constants for T T containing single stranded and duplex DNA. The results support the base-flipping mechanism suggested earlier. The proposed active-site model reveals three types of interactions: (i) ion-pair interactions at the rim of the active site between the positively charged residues on the enzyme surface (Arg226, Arg342, A...
Distribution of and insights from soil protozoa of the Olympic coniferous rain forest

Abstract Decomposition occurs in the surface litter and soil to support temperate rainforests, but little is known about the protozoa that stimulate bacterial activity and turnover. I examined surface litter and top soils, fallen logs, and epiphytes within 2 m from the soil surface in Olympic National Park, USA, of the Pacific Northwest Temperate Coniferous Rain Forest. Ciliates in surface litter numbered 180–580 g−1 dry weight, but were reduced by 20–60% in the underlying soils. Testate amoebae numbered 18,000–77,000 g−1 dry weight in both litter and soil although they were often more abundant in underlying soils. Rotting logs, essential for tree regeneration, supported similar numbers of ciliates, but twice the numbers of testate amoebae. In three epiphytic soils, ciliates numbered 350–550, and testate amoebae 35,000–195,000 g−1 dry weight of soil. In these soils, 26 species of gymnamoebae, 64 species of ciliates, and 113 species of testate amoebae were found. About 65% of the individuals in ciliate and 45% in testate amoebae populations were small, r-selected taxa. Rain forest soil protozoa have distinct testate amoebae populations, and are characterized by enormous biodiversity, the dominance of acrostome species, the proliferation of Euglypha and Nebela species, and the appearance of aquatic taxa. Ecological succession of ciliates and testate amoebae follows an additive (non-replacement) pattern according to a neutral model. The large numbers of persistent r-selected species respond to ecosystem disturbances by mobilizing quickly to resume the bacterivory necessary to help restore the recovering above-ground plant community.
Control of Transfer RNA Maturation by Phosphorylation of the Human La Antigen on Serine 366

Conversion of a nascent precursor tRNA to a mature functional species is a multipartite process that involves the sequential actions of several processing and modifying enzymes. La is the first protein to interact with pre-tRNAs in eukaryotes. An opal suppressor tRNA served as a functional probe to examine the activities of yeast and human (h)La proteins in this process in fission yeast. An RNA recognition motif and Walker motif in the metazoan-specific C-terminal domain (CTD) of hLa maintain pre-tRNA in an unprocessed state by blocking the 5'-processing site, impeding an early step in the pathway. Faithful phosphorylation of hLa on serine 366 reverses this block and promotes tRNA maturation. The results suggest that regulation of tRNA maturation at the level of RNase P cleavage may occur via phosphorylation of serine 366 of hLa.
Designing opportunistic user interfaces to support a collaborative museum exhibit

This research explores how to support collaborative learning practices when science museum visitors employ their own personal mobile devices as Opportunistic User Interfaces (O-UIs) to manipulate a simulation-based museum exhibit. The sophisticated graphical capabilities of modern mobile devices have the potential to distract visitors, a phenomenon known as the heads-down effect. To study the impact of O-UI design on collaboration, a highly-dynamic "complex" O-UI was contrasted against more simplistic, "remote-control" OUI design, in the context of a cancer-treatment simulation. As expected, when groups used the "complex" O-UI, there was less visitor-visitor interaction, but unexpectedly, their conversations were of higher quality. They also engaged in better task division and displayed better task performance. The increased attention "simple" O-UI users were able to devote to monitoring one another's actions seemed to encourage emergent competitive behaviors, which disproportionately affected the engagement of female visitors. "Complex" groups showed no gender-related differences in engagement.
Influence of summer marine fog and low cloud stratus on water relations of evergreen woody shrubs ( Arctostaphylos : Ericaceae) in the chaparral of central California

Mediterranean-type climate (MTC) regions around the world are notable for cool, wet winters and hot, dry summers. A dominant vegetation type in all five MTC regions is evergreen, sclerophyllous shrubland, called chaparral in California. The extreme summer dry season in California is moderated by a persistent low-elevation layer of marine fog and cloud cover along the margin of the Pacific coast. We tested whether late dry season water potentials (Ψmin) of chaparral shrubs, such as Arctostaphylos species in central California, are influenced by this coast-to-interior climate gradient. Lowland coastal (maritime) shrubs were found to have significantly less negative Ψmin than upland interior shrubs (interior), and stable isotope (δ13C) values exhibited greater water use efficiency in the interior. Post-fire resprouter shrubs (resprouters) had significantly less negative Ψmin than co-occurring obligate seeder shrubs (seeders) in interior and transitional chaparral, possibly because resprouters have deeper root systems with better access to subsurface water than shallow-rooted seeders. Unexpectedly, maritime resprouters and seeders did not differ significantly in their Ψmin, possibly reflecting more favorable water availability for shrubs influenced by the summer marine layer. Microclimate and soil data also suggest that maritime habitats have more favorable water availability than the interior. While maritime seeders constitute the majority of local Arctostaphylos endemics, they exhibited significantly greater vulnerability to xylem cavitation than interior seeders. Because rare seeders in maritime chaparral are more vulnerable to xylem cavitation than interior seeders, the potential breakdown of the summer marine layer along the coast is of potential conservation concern.
Enterobacter cloacae is an endophytic symbiont of corn

The bacterium Enterobacter cloacae is presently used for biocontrol of postharvest diseases of fruits and vegetables and as a preplant seed treatment for suppression of damping-off. This bacterium has apparent affinities for several grass species, but it is not considered to be an endophyte. While screening corn for fungi and bacteria with potential for biocontrol of various corn diseases, the surface-sterilized kernels of one unknown Italian corn cultivar produced fungus-free corn seedlings with roots endophytically infected by E. cloacae. This paper describes the microscopic nature of E. cloacae RRC 101 with corn, and the in vitro control of Fusarium moniliforme and other fungi with this bacterium. Light and electron microscopy determined that this isolate of E. cloacae was biologically associated with corn seedling roots, where it was distributed intercellularly within the cortex and stele. This is a first report of a strain of this bacterium as an endophytic symbiont of roots. Following a topical application of E. cloacae to kernels, and upon germination this bacterium readily infected roots of two other corn cultivars. The bacterium was observed within the endosperm of germinating corn seedling, but germination was not affected. Further, the bacterium was isolated from leaves and stems of 3- to 6-week-old seedlings indicating that the above ground portions of corn were also colonized. There was no evidence of damage to cells of the root during a three to four week observation period. This bacterium was antagonistic to several isolates of the corn pathogen Fusarium moniliforme, and to two other species of fungi, all of which produce mycotoxins on corn.
Blood oxygen affinity in high- and low-altitude populations of the deer mouse.

Abstract There is little solid evidence for specific genetic adaptations in animal populations native to high altitude. There is also continuing debate over what oxygen transport characteristics are truly adaptive at high altitude. We have attempted to elucidate both problems through population genetic and physiological studies of the deer mouse, Peromyscus maniculatus . That species is noteworthy because it inhabits the widest range of altitudes of any North American mammal, and it shows a high degree of genetic variation in hemoglobins. Deer mice were collected from 35 populations representing ten nominal subspecies covering a broad geographical range of the United States. The mice were acclimated to low altitude (340 m); then a mixing method was used to determine P 50 and other blood gas parameters on samples pooled from individuals of representative hemoglobin genotypes. When the data from all subspecies were combined, there was a highly significant negative correlation between P 50 and the native altitude of the population. Tests on progeny reared at low altitude indicated that the differences in P 50 were primarily genetic. Part of the clinal variation in P 50 could be attributed to 2,3-DPG effects; high-altitude populations showed lower baseline DPG/Hb ratios. Surprisingly, within those subspecies which inhabit a wide range of altitudes, there was no correlation between P 50 and native altitude. Our tentative conclusion from these data and data presented elsewhere is that deer mouse populations do show genetic adaptations to high altitude. However, because of gene exchange between populations, the genetic characteristics of a population reflect the average altitude over a relatively broad geographic area.
Decreased vulnerability to ventricular fibrillation by vasodilator-induced baroreceptor sensitisation

Vulnerability to ventricular fibrillation (VF) is affected by changes in systemic arterial blood pressure which are mediated through the sympathetic nervous system. We determined that small doses of a vasodilator drug can abolish the enhanced ventricular vulnerability induced by norepinephrine infusion. Noradrenaline (0.5 μg·kg−l·min−1) caused a fall in ventricular fibrillation threshold from 30 to 20 mA (P<0.001). Pretreatment with prostaglandin E1, I2 or nitroglycerin at doses which reduced mean arterial blood pressure by 0.7 to 1.3 kPa (5 to 10 mmHg) abolished the enhanced vulnerability produced by noradrenaline. Following baroreceptor denervation, these agents no longer afforded protection against the profibrillatory action of noradrenaline. We conclude that small doses of vasodilator agents can augment ventricular electrical stability. The mechanism for this protective action appears to be a decrease in cardiac sympathetic tone resulting from vasodilatation of baroreceptor areas.
A model of the firm in time and space

Abstract We consider a multi-plant monopoly that sells to markets which are geographically separated and which stores product over time via an inventory capability. It is assumed that plant average production cost is U-shaped and that, if the output of a plant's production run were sold to a single market at only one point in time, the plant would operate on the falling portion of its average cost curve. Hence, it is in the interest of the firm to aggregate markets, both spatially and temporally, to lower average production cost. We develop the optimal joint interplant spacing-inventory policy. We also consider the effects changes in freight costs, storage costs, and interest charges have on the firm's optimal policy.
Mining community structure of named entities from free text

Although community discovery has been studied extensively in the Web environment, limited research has been done in the case of free text. Co-occurrence of words and entities in sentences and documents usually implies connections among them. In this paper, we investigate the co-occurrences of named entities in text, and mine communities among these entities. We show that identifying communities from free text can be transformed into a graph clustering problem. A hierarchical clustering algorithm is then proposed. Our experiment shows that the algorithm is effective to discover named entity communities from text documents.
Comment on ``Modal expansion approach to optical-frequency-comb generation with monolithic whispering-gallery-mode resonators''

Authors of a recent paper [Y. K. Chembo and N. Yu, Phys. Rev. A 82, 033801 (2010)] claimed to have developed a general framework for description of nonlinear effects in whispering-gallery-mode resonators with particular focus on optical-frequency-comb generation. In this Comment we demonstrate that the author's approach contains mathematical errors affecting some of the results of the paper. Fortunately, analysis of this phenomenon using a mathematically more rigorous approach shows that the main conclusions of that paper remain intact.
Large-Size Liftable Inverted-Nanobowl Sheets as Reusable Masks for Nanolithiography

A low-cost procedure is introduced for fabricating large-area, liftable, ordered TiO2 nanobowl sheets. The sheet is made using the template of self-assembled polystyrene spheres, followed by atomic layer deposition (ALD), ion milling, and etching. By introducing a thin organic layer between the nanobowls and the substrate, the whole sheet can be lifted-off in full size. The dimension of the holes at the bottom of the nanobowls is controlled by additional ALD; thus, the sheet has been applied as a reusable mask for producing nanodot patterns with designed sizes. This technique demonstrates a simple and economic nanolithiography approach for producing various designed patterns without using a clean room, and it has a great potential for scale-up, mass production, and commercial applications.
SQUID detected NMR in microtesla magnetic fields

Abstract We have built an NMR system that employs a superconducting quantum interference device (SQUID) detector and operates in measurement fields of 2–25 μT. The system uses a pre-polarizing field from 4 to 30 mT generated by simple room-temperature wire-wound coils that are turned off during measurements. The instrument has an open geometry with samples located outside the cryostat at room-temperature. This removes constraints on sample size and allows us to obtain signals from living tissue. We have obtained 1 H NMR spectra from a variety of samples including water, mineral oil, and a live frog. We also acquired gradient encoded free induction decay (FID) data from a water-plastic phantom in the μT regime, from which simple projection images were reconstructed. NMR signals from samples inside metallic containers have also been acquired. This is possible because the penetration skin depth is much greater at the low operating frequencies of this system than for conventional systems. Advantages to ultra-low field NMR measurements include lower susceptibility artifacts caused by high strength polarizing and measurement fields, and negligible line width broadening due to measurement field inhomogeneity, reducing the burden of producing highly homogeneous fields.
Applications of isoparametric three-dimensional hybrid-stress finite elements with least-order stress fields

Abstract This paper investigates the factors relating to element stability, coordinate invariance and optimality in 8- and 20-noded three-dimensional brick elements in the context of hybrid-stress formulations with compatible boundary displacements and both a priori and a posteriori equilibrated assumed stresses. Symmetry group theory is used to guarantee the essential non-orthogonality of the stress and strain fields, resulting in a set of least-order selections of stable invariant stress polynomials. The performance of these elements is examined in numerical examples providing a broad range of analytical stress distributions, and the results are favourably compared to those of the displacement formulation and a stress-function based complete stress approach with regard to displacements, stresses, sampling, convergence and distortion sensitivity.
Learning to Translate Sequence and Structure to Function: Identifying DNA Binding and Membrane Binding Proteins

A protein's function depends in a large part on interactions with other molecules. With an increasing number of protein structures becoming available every year, a corresponding structural annotation approach identifying such interactions grows more expedient. At the same time, machine learning has gained popularity in bioinformatics providing robust annotation of genes and proteins without sequence homology. Here we have developed a general machine learning protocol to identify proteins that bind DNA and membrane. In general, there is no theory or even rule of thumb to pick the best machine learning algorithm. Thus, a systematic comparison of several classification algorithms known to perform well is investigated. Indeed, the boosted tree classifier is found to give the best performance, achieving 93% and 88% accuracy to discriminate non-homologous proteins that bind membrane and DNA, respectively, significantly outperforming all previously published works. We also attempted to address the importance of the attributes in function prediction and the relationships between relevant attributes. A graphical model based on boosted trees is applied to study the important features in discriminating DNA-binding proteins. In summary, the current protocol identified physical features important in DNA and membrane binding, rather than annotating function through sequence similarity.
Heavisidian monopoles and quantization of gravitational charge

On the other hand, in case of gravi tat ion, some a t tempts have been made for the quant izat ion of the gravi ta t ional charge (4,6). MOTZ has obtained a similar quantization condition (4) for gravi ta t ional charge by quantizing one of the angular-momentum components in the general relat ivist ic equation of motion of two bodies. However, because of the recent in teres t shown in the l inear equations for gravi ta t ional field (ez), in this paper I would l ike to obtain a gravi ta t ional charge quantizat ion condit ion from the l inear equations for gravi ta t ional field. The postulat ion of Heavisidian monopoles (s.8) has increased the s tructural symmetry between the l inear equations for gravi ta t ional field and the extended Maxwell 's equa-
The determination of stochastic loads on horizontal axis wind turbine blades

The FAST Code which is capable of determining structural loads of a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data are given at two wind speeds for the ESI-80. The FAST Code models a two-bladed HAWT with degrees-of-freedom for blade bending, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffnesses, and weights to differ and the code models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting occurrence histograms, and azimuth averaged bin plots. It is concluded that agreement between the FAST Code and test results is good.
Internal calibration techniques for quadrature receiver mismatch errors

The performance of systems requiring the use of quadrature receivers is significantly degraded in the presence of mismatch errors between the In-phase (I) and Quadrature (Q) branches. This paper discusses the mismatch problem and introduces promising solutions. These solutions are independent of communication format, which improves the generality and flexibility of the techniques.Current literature emphasizes estimation of either local oscillator (LO) mismatch or frequency dependent path mismatch using an external calibration signal. This paper develops techniques to estimate both LO mismatch and path mismatch using internally generated calibration signals derived from the system local oscillator. Once the mismatch errors are obtained, LO mismatch can be corrected by analog adjustment and path mismatches are corrected digitally.