cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of CO2 flux through hollow-fiber membranes using pH modeling

Abstract CO2 must be delivered efficiently during large-scale microalgal cultivation. Bubbleless mass-transfer via diffusion through hollow-fiber membranes (HFM) can achieve much higher CO2-transfer efficiency than traditional sparging systems. This study developed and used a model to compute accurate values for the CO2 flux ( J C O 2 ), overall mass-transfer coefficient (KL), and overall volumetric mass-transfer coefficient (KLa) based on the rate of change of pH in batch experiments. A composite HFM comprised of two macroporous polyethylene layers and a nonporous polyurethane layer was tested for CO2 transfer to a sodium carbonate solution using a range of total pressures, inlet CO2 concentrations, and open-end versus closed-end modes of operation. The model accurately computed JCO2 and KLa for pH values above 8. Key trends are that (i) JCO2 and KLa increased with increasing average inlet CO2 partial pressure; (ii) open-end HFMs performed better than closed-end HFMs when the supplied CO2 was less than 100%; and (iii) the available membrane area used for CO2 mass-transfer decreased as the inlet CO2 partial pressure decreased due to depletion of CO2 inside the membrane, especially for closed-end HFMs, since inert gases could not be vented.
Cracking open the DNN black-box: Video Analytics with DNNs across the Camera-Cloud Boundary

Advancements in deep neural networks (DNNs) and widespread deployment of video cameras have fueled the need for video analytics systems. Despite rapid advances in system design, existing systems treat DNNs largely as "black boxes'' and either deploy models entirely on a camera or compress videos for analysis in the cloud. Both these approaches affect the accuracy and total cost of deployment. In this position paper, we propose a research agenda that involves opening up the black box of neural networks and describe new application scenarios that include joint inference between the cameras and the cloud, and continuous online learning for large deployments of cameras. We present promising results from preliminary work in efficiently encoding the intermediate activations sent between layers of a neural network and describe opportunities for further research.
GOES-R Series Spacecraft and Instruments

Abstract The Geostationary Operational Environmental Satellites (GOES)-R Series is the new generation of geostationary environmental satellites replacing satellites from the previous generation GOES-N Series (GOES-13,-14,-15), which entered service in 2010. The GOES-R Series provides dramatic upgrades in sensor technology, improving on both the GOES-N Series and the GOES-IM (GOES-8–12) Series, which entered service in 1994. Six new remote sensing instruments were designed for each of the four spacecraft in the GOES-R Series and they provide significant improvements in spectral, temporal, and spatial resolution and coverage and introduce wholly new observational capabilities including the first operational lightning mapper.
Understanding Students' Computational Fluency: Synechistically Using Test Scores and Interviews for a Richer Picture

Mathematics education researchers are tasked with solving practical research problems involving complex constructs in complex settings. The effective integration of quantitative and qualitative data allows researchers to draw more nuanced conclusions about these complex phenomena. This article describes the use of a convergent parallel mixed methods design to integrate two seemingly conflicting data sources that measured six second-grade students' development of computational fluency. The mixed methods analysis of students' computational fluency assessments and interviews showed that there was variation in students' assessment scores, strategy use, and engagement of number sense. Within these variations, the quantitative and qualitative data converged or diverged at various measurement points, and the results highlight the importance of merging the two data sets to capture a richer picture of students' computational fluency. Implications for using mixed methods in understanding how mathematics learning occurs in classrooms are discussed.
4-Hour postoperative PTH level predicts hypocalcemia after thyroidectomy in children.

Abstract Background Hypocalcemia occurs frequently after a total thyroidectomy in pediatric patients. Four hour postoperative PTH monitoring predicts the need for calcium supplementation in the adult thyroidectomy population. We evaluated the role of the 4 h postoperative PTH level in determining the need for calcium supplementation after thyroidectomy in the pediatric population. Methods This is a retrospective review of children undergoing total thyroidectomy by a single pediatric surgeon from July 2011 through July 2018. Intact PTH obtained four hours postoperatively determined the need for calcium supplementation for patients beginning in November 2014 onward. Serum total calcium levels were monitored concurrently with serum intact PTH levels. Serum calcium levels were followed in our Multispecialty Pediatric Endocrine Surgery clinic within the month following thyroidectomy. Results From July 2011 through July 2018, there were a total of 56 total thyroidectomies at our institution. Prior to November 2014, all pediatric total thyroidectomies received calcium supplementation per our institutional protocol. Based on ionized calcium levels, 26.3% (5/19) of children developed hypocalcemia. From November 2014 to July 2018, 37 pediatric patients required total thyroidectomies. 29.7% (11/37) had low 4-h postoperative PTH levels. 72.7% (8/11) patients with low 4-h postoperative PTH levels had corresponding postoperative day 1 total calcium levels less than 8.5 or ionized calcium levels less than 1.12, and five children (45.5%) developed symptomatic hypocalcemia. 70% (26/37) of children had normal 4-h postop PTH levels, with only 5 (19%) ever developing hypocalcemia. No patients with a normal postop PTH level developed symptomatic hypocalcemia or required IV calcium repletion. A single 4-h postoperative PTH Conclusion The 4-h postoperative serum PTH level can help determine the need for calcium supplementation in pediatric patients undergoing total thyroidectomy, thereby reducing unnecessary calcium supplementation and serial lab draws to monitor for postoperative hypocalcemia. Level of evidence Level II.
The interdependence of mammary-specific super-enhancers and their native promoters facilitates gene activation during pregnancy

Lineage-specific genetic programs rely on cell-restricted super-enhancers, which are platforms for high-density transcription factor occupation. It is not known whether super-enhancers synergize specifically with their native promoters or provide autonomous and independent regulatory platforms. Here, we investigated the ability of the mammary Wap super-enhancer to activate the promoter of the juxtaposed and ubiquitously expressed Tbrg4 gene in the mouse mammary gland. The Wap super-enhancer was fused, alone or in combination with the Wap promoter, to the Tbrg4 gene. While the super-enhancer increased the expression of the Tbrg4 promoter five-fold, the combination of the super-enhancer and promoter resulted in 80-fold gene upregulation, demonstrating lineage-specific promoter-enhancer synergy. Employing ChIP-seq profiling to determine transcription factor binding and identify activating histone marks, we uncovered a chromatin platform that enables the high-level expression of the native promoter-enhancer but not the heterologous promoter. Taken together, our data reveal that lineage-specific enhancer-promoter synergy is critical for mammary gene regulation during pregnancy and lactation.
Functional characterization of human Heschl's gyrus in response to natural speech

Heschl9s gyrus (HG) is a brain area that includes the primary auditory cortex in humans. Due to the limitations in obtaining direct neural measurements from this region during naturalistic speech listening, the functional organization and the role of HG in speech perception remains uncertain. Here, we used intracranial EEG to directly record the neural activity in HG in eight neurosurgical patients as they listened to continuous speech stories. We studied the spatial distribution of acoustic tuning and the organization of linguistic feature encoding. We found a main gradient of change from posteromedial to anterolateral parts of HG. Along this direction, we observed a decrease in frequency and temporal modulation tuning, and an increase in phonemic representation, speaker normalization, speech-sensitivity, and response latency. We did not observe a difference between the two brain hemispheres. These findings reveal a functional role for HG in processing and transforming simple to complex acoustic features and informs neurophysiological models of speech processing in the human auditory cortex.
Development and Psychometric Testing of the Mealtime Engagement Scale in Direct Care Providers of Nursing Home Residents with Dementia

BACKGROUND AND OBJECTIVES Mealtime engagement is defined as verbal and nonverbal assistance provided by caregivers to guide and motivate care recipients in eating. Quality mealtime engagement is critical to improve mealtime difficulties and intake among older adults with dementia requiring eating assistance. Few tools are feasible and valid to measure mealtime engagement. This study developed and tested the Mealtime Engagement Scale (MES). RESEARCH DESIGN AND METHODS Items were developed based on literature review and expert review and finalized based on content validity and corrected item-total correlation. A secondary analysis of 87 videotaped observations capturing 18 nursing home staff providing mealtime care to residents with dementia was conducted. Internal consistency, interrater reliability, and intrarater reliability were assessed. Concurrent and convergent validity were examined through correlation (rs) with the Relational Behavior Scale (RBS) and the Mealtime Relational Care Checklist (M-RCC), respectively. RESULTS The 18-item MES was developed with adequate content validity (Scale-content validity index [CVI] = 1.00; Scale-CVI/Average = 0.962-0.987). Each item is scored from 0 (never) to 3 (always). The total scale score ranges from 0 to 54. Higher scores indicate greater mealtime engagement. The MES had very good internal consistency (Cronbach's α = 0.837), outstanding interrater reliability (interclass correlation = 0.920), outstanding intrarater reliability (interclass correlation = 0.956), adequate concurrent validity based on strong correlation with the RBS (rs = 0.821, p < .001), and fair convergent validity based on weak correlation with the M-RCC (rs = 0.219, p = .042). DISCUSSION AND IMPLICATIONS Findings provide preliminary psychometric evidence of MES to measure mealtime engagement. Future testing is needed among more and diverse samples in different care settings to accumulate psychometric evidence.
Quantum-light shaping and quantum spectroscopy in semiconductors

Abstract Ultrafast spectroscopy can be extended to quantum spectroscopy if quantum correlations of light, including entanglement become freely adjustable for light pulses having an arbitrary wave form and intensity. The consequences of this important step are overviewed by focusing on light-to-matter mapping to directly detect and control many-body states as a new, high-precision resource for quantum-information science. Both theoretical and experimental approaches are developed to realize all-experimental quantum spectroscopy with semiconductors. In this context, a quantum-light shaping methodology is introduced and experimentally demonstrated using pulse-to-pulse weighted postselection, without altering the ultrafast light pulses themselves. This conditional measurement technique meets the stringent criteria for realizing direct, user-defined quantum-optical excitations of many-body states.
Distributed Federalism: The Transformation Of Younger

For decades federal courts have remained mostly off-limits to civil rights cases challenging the constitutionality of state criminal proceedings. Younger abstention, which requires federal courts to abstain from suits challenging the constitutionality of pending state prosecutions, has blocked plaintiffs from bringing meritorious civil rights cases and insulated local officials and federal courts from having to defend against or decide them. Younger’s reach is broad. It has forced political protestors (from the Vietnam era to Black Lives Matter) to challenge the constitutionality of their arrests and prosecutions within their state criminal prosecution. And it has made it difficult to challenge in federal court the constitutionality of serious, routine, widespread practices impacting indigent criminal suspects and defendants. Only recently have civil rights litigants dared to test Younger. And, lo and behold, federal courts are pivoting away from Younger abstention, granting relief in some cases, and opening the possibility that federal courts could become an important venue for criminal justice reform. This article argues that courts are rejecting Younger abstention and instead distributing federalism concerns throughout the litigation. This “distributed federalism” approach was modeled decades ago in Gerstein v. Pugh, which powerfully showed that by rejecting Younger abstention, federal courts do not reject federalism. Today federalism is baked into the civil procedure infrastructure and courts’ reluctance—institutional, doctrinal, and federalism-based––to order injunctive relief against state courts. As litigants get past Younger abstention, the new battleground will be the degree to which federalism shapes the scope of constitutional rights and injunctive and declaratory relief. In this new terrain, Younger’s non-interference principle will transform from an abstention doctrine to a remedial tool that helps courts justify the manner and degree of relief that will protect individual rights in state criminal proceedings.
Incorporating rain-on-snow into the SWAT model results in more accurate simulations of hydrologic extremes

Abstract In many cold climates, rain-on-snow (ROS) events are associated with severe snowmelt and flooding. ROS events also rapidly deplete snowpacks, reducing the potential for subsurface water storage later in the year. We incorporated a simple, easily transferable energy-balance ROS model into the Soil and Water Assessment Tool (SWAT) to assess how ROS melt affects winter floods and summer hydrological drought over a large area such as the North American Great Lakes Basin, where ROS is associated with severe snowmelt events. Using 504 random parameter sets, the modification consistently improved simulations and led to higher winter flows and lower summer flows compared with the unmodified SWAT. The SWAT ROS model also had improved performance for simulating daily streamflow in 501 (99.4%) of the 504 random parameter sets and improved performance for simulating daily snowpack in 504 (100%) of the sets, compared to the unmodified SWAT. We then used streamflow and snow water equivalent as the objectives in a multivariable, multi-site calibration to compare SWAT ROS with the unmodified SWAT. The SWAT ROS model simulated 51% larger peak (0.95 quantile) daily flows during winter and spring and 58% lower daily summer low (0.05 quantile) flows across the Great Lakes Basin, compared to the unmodified SWAT. We also used observed snowpack data to demonstrate how the unmodified SWAT can miss daily ROS melt events, delaying snowmelt to later in the season. Thus, the unmodified SWAT model appears to be misrepresenting the streamflow distribution in areas where ROS events occur, which is particularly important for modeling extreme events. When simulating conditions in cold climates at diverse scales up to large basins or continents, hydrological models such as SWAT must incorporate ROS, as many other models already do. This has implications for water resources management confronted with hydrological extremes in ROS-prone areas around the world, especially where climate change is altering ROS melt events.
Four Minutes to Midnight: The World in 1980

The year 1980 brought several crises that severely revived superpower tensions. These included the ongoing effects of the Islamic revolution in Iran and the Soviet invasion of Afghanistan. The Soviets too faced an alarming situation in Eastern Europe with the threat of revolution in Poland, and the armed invasion that might follow such a development. Nuclear tensions ran very high, focused especially on the development of new nuclear missiles in Europe. Nuclear war plans suggested that any armed conflict in Europe would lead to the massive deployment of nuclear armaments. Also in 1980, the election of US President Ronald Reagan brought a new hardline vision to the center of that country’s policymaking.
Duplo Bricks Sorting by PR2

Parts sorting is a very old field of research and very accurate vibration-based parts feeders have been designed in industries ([1], [3]). A parts feeder can not only sort but also position and orient bulk parts before they are fed to an assembly station and thus, help in micro-assembly. Work has also been done on sorting parts by shapes using Bayesian techniques and parallel-jaw grippers ([2], [4]). However, these methods assume availability of very specific equipment or require parts to be fed to the feeder one by one. Our goal is to use manipulation as a tool to aid perception in a household environment to understand it better. Sorting duplo bricks, a parts-sorting of a very specific kind, has been demonstrated as an example.
Health information technology: A key ingredient of the patient experience

In this exploration to understand the linkages of health information technology (HIT) and patient experience, a comprehensive literature search was conducted patient satisfaction, and technology”, on the MEDLINE, PubMed, and EMBASE databases citations. Eventually, 35 of the most relevant articles were reviewed beginning to explore the question, as the transformation of hea return on investment to a patients’ perception of their care in an organization patient experience? The results reveal there is in fact more questions than answers th opportunities for exploration and research are encouraged. That noted, the literature and examples emerging in practices across healthcare are showing that technology and the patient experience are moving closer to one anothe passes. HIT is truly evolving as a key ingredient in the patient experience conversation.
Passive stabilization of MHD instabilities at high {beta}n in the HBT-EP Tokamak

The HBT-EP Tokamak has been designed, built, and is now fully operational in the Columbia University Plasma Physics Laboratory. One of the primary purposes of this facility is to study the effects of a conducting wall on the MHD modes that lead up to plasma disruptions. Of particular interest are the types of instabilities that are driven by the kinetic pressure of the plasma, because these instabilities are believed to be responsible for the present limit to plasma {beta} with {beta} {proportional_to} /B{sup 2}, where the is the volume averaged pressure and B is the magnetic field. To this end, a movable conducting wall has been installed inside the HBT-EP vacuum chamber. The primary result of this thesis are the initial results from experiments that study the effect of this wall on plasma instabilities. The experiment shows that the conducting wall significantly reduces the growth rate of instabilities that precede a plasma disruption that occurs when the value of {beta} is near the Troyon limit. The location of the wall required for significant stabilization is b/a {approximately}1.2 where a is the minor radius of the plasma and b is the minor radial location of the wall. Moving the wall closer than b/a = 1.2 slightly degrades the stabilizing effect, which is consistent with recent theories.
Comment on Money Market Funds for SEC

This letter offers a specific proposal for the regulation of Money Market Funds (MMFs). The proposal responds to comments made at the Commission’s Roundtable Discussion on May 10, 2011 and the public comments on the President’s Working Group report on Money Market Fund Reform, per Investment Company Act Release No. IC-29497. I respectfully request that this correspondence be included in the record of the Commission’s rule-making in this area.
Image-Schemata-Based Spatial Inferences: The Container-Surface Algebra

Algebras over spatial relations have become an important aspect of spatial reasoning for retrieving and handling large and complex spatial data sets. While such spatial relations play a fundamental role in specifying constraints in a spatial query language, there has been little concern as to whether existing spatial-relation algebras are cognitively plausible. In order to construct more intuitive and easier-to-use spatial query languages, this work pursues an alternative approach to spatial reasoning based on a small set of operators derived from concepts closely related to human thinking. The work focuses on a set of operators that are associated with the behavior of image schemata—recurrent patterns that people learn through bodily experiences and use for understanding the meaning of objects and situations. A study of a small-scale space, involving the surface and container schemata, describes objects in this space and the possible spatial relations among them. The informal description of these configurations are translated into a formal algebraic specification and generalized for spatial relations in a scene that involves surface and container schemata. This formalization axiomatizes spatial inferences that are then applied and compared to a larger geographic space. As a result, a small set of spatial operators are defined that apply to small- and large-scale spaces; however, these operators show discrepancies when applied to a combination of objects belonging to different scales. Interactive spatial query languages and spatial inference engines may be built on such basic spatial concepts as image schemata if they account for the differences in types, nature, and sizes of objects.
Place, Poverty, and Algebra: A Statewide Comparative Spatial Analysis of Variable Relationships

Place matters in moderating variable relationships between algebra performance and educational variables because there are differences on the socioeconomic (SES) poverty-affluence continuum that shape local contexts. This article examines relationships between variables for school district demographic composition, teaching and financial contexts, student behavior variables, and Algebra I performance as measured by a statewide test aggregated at the district level. The purpose is to investigate how these relationships vary across 471 districts within a state using spatial mapping. Local R2’s from geographically weighted regressions (GWR) are mapped using a geographic information system (GIS) to demonstrate variation in relationships across districts. Results show the importance of allowing relationships to “vary” between local contexts and that using a global measure of variable relationships based on aggregated data fails to capture important local variation. This analysis suggests that policy focused on addressing the influence of poverty on algebra performance should be targeted based on region specific models.
Essay Tests: Use, Development, and Grading

(1992). Essay Tests: Use, Development, and Grading. The Clearing House: A Journal of Educational Strategies, Issues and Ideas: Vol. 65, No. 3, pp. 175-177.
Higher Vulnerable Elders Survey Scores Predict Death and Functional Decline in Vulnerable Older People

OBJECTIVES: To examine whether the Vulnerable Elders Survey (VES-13) score predicts risk of death and functional decline in vulnerable older adults. DESIGN: Longitudinal evaluation with mean follow-up of 11 months (range 8–14 months). SETTING: Two managed care organizations in the United States. PARTICIPANTS: Four hundred twenty community-dwelling older people identified as having moderate to high risk of death and functional decline based on a VES-13 score of 3 or higher. These older people were enrolled in the Assessing Care of Vulnerable Elders observational study. MEASUREMENTS: Baseline: VES-13 score, sex, income, cognitive score, and number of medical diagnoses. Outcome measures: functional decline and death. RESULTS: VES-13 scores strongly predicted death and functional decline (P<.001, area under the receiver operating curve=0.66). The estimated combined risk of death and decline rose with VES-13 score, increasing from 23% for older people with a VES-13 score of 3 to 60% for those with a score of 10. Other measures (sex, comorbidity) were not significant predictors of death or decline over this period after controlling for VES-13 score. CONCLUSION: The VES-13 score is useful as a screening tool to detect risk of health deterioration in already vulnerable older populations, and higher scores reflect greater risk over a short follow-up period.
Life Events as Stressors in Childhood and Adolescence

Children, in the process of growing up, frequently encounter a range of life experiences or events that may result in changes in their lives and that necessitate varying degrees of coping and adaptation. They often experience the birth of siblings. They must adapt to school entry and often to change from one school to another. In our mobile society, these school changes are often associated with a change in residence, which may in turn, be correlated with a host of other changes that require additional coping efforts. Parental separation and divorce, serious illness or injury to family members, deaths in the family, and illnesses experienced by the children themselves are among other life events that affect the lives of children. Although children vary in the extent to which they experience significant life changes, such events are a potential source of stress to which all children are exposed to a greater or lesser degree.
Micrometeorologic Methods for Measuring the Post-Application Volatilization of Pesticides

A wide variety of micrometeorological measurement methods can be used to estimate the postapplication volatilization of pesticides from treated fields. All these estimation methods require that the entire study area have the same surficial characteristics, including the area surrounding the actual study site, and that the pesticide under investigation be applied as quickly and as uniformly as possible before any measurements are made. Methods such as aerodynamic profile, energy balance, eddy correlation, and relaxed eddy accumulation require a large (typically 1 or more hectare) study area so that the flux measurements can be made in a well developed atmospheric boundary-layer and that steady-state conditions exist. The area surrounding the study plot should have similar surficial characteristics as the study plot with sufficient upwind extent so the wind speed and temperature gradients are fully developed. Mass balance methods such as integrated horizontal flux and trajectory simulations do not require a large source area, but the area surrounding the study plot should have similar surficial characteristics.
A Framework for Long Distance Face Recognition Using Dense - and Sparse-Stereo Reconstruction

This paper introduces a framework for long-distance face recognition using both dense- and sparse-stereo reconstruction. Two methods to determine correspondences of the stereo pair are used in this paper: (a) dense global stereo-matching using maximum-a-posteriori Markov Random Fields (MAP-MRF) algorithms and (b) Active Appearance Model (AAM) fitting of both images of the stereo pair and using the fitted AAM mesh as the sparse correspondences. Experiments are performed regarding the use of different features extracted from these vertices for face recognition. A comparison between the two approaches (a) and (b) are carried out in this paper. The cumulative rank curves (CMC), which are generated using the proposed framework, confirms the feasibility of the proposed work for long distance recognition of human faces.
Justice and the Outsider: Jurisdiction Over Nonmembers in Tribal Legal Systems

Over the last quarter century, the Court has progressively limited tribal jurisdiction over both non-Indians and Indians who are not members of the tribe. The Article examines these decisions to show that they owe less to established Indian law doctrine than to two assumptions: first, that tribal courts will be unfair to outsiders and second, that jurisdiction over outsiders has little to do with tribal self-government. It then tests these assumptions against an examination of all cases decided by the Navajo Nation appellate courts over the last thirty-five years and the history and contemporary situation of tribal legal systems. This investigation reveals that with respect to the first assumption, the Navajo appellate courts are remarkably balanced in hearing cases involving outsiders. Non-Navajos win 47.4 percent and lose 52.6 percent of the cases in which they appear before the courts. The decisions, moreover, appear to be qualitatively balanced, even with respect to cases and issues that might appear particularly vulnerable to bias. This latter finding is supported by a more limited review of decisions by other tribal courts. In contrast with the second assumption, cases involving non-members appear to be crucial for tribal self-government. They comprise a disproportionately large number of cases before the appellate courts, and form an equally disproportionate role in maintaining judicial legitimacy and fairness. This is particularly true given the origin of tribal courts as tools both of non-Indian acculturation and control and tribal resistance, and the current struggle of tribes to thrive under radically changed circumstances without losing their cohesion as distinct communities.
Miniaturized-element frequency selective surfaces with narrowband, higher-order bandpass responses

The selectivity and response type of the frequency response of a frequency selective surface (FSS) are important factors that determine the suitability of an FSS for a given application. A common application of FSSs is to use them to shield sensitive electronic devices form unwanted interference or jamming signals with frequencies close to the main transmission band of the device. In such situations, spatial filters with highly-selective and narrowband transmission windows are required. FSSs with higher-order bandpass or bandstop responses acts similar to coupled-resonator filters. Therefore, their operational bandwidths are inversely related to quality factors of their resonators. Thus, to achieve a narrow-band response, higher quality factors are needed. For the case of traditional FSSs, these resonators are created using resonant elements within a unit cell. Miniaturized-element frequency selective surfaces (MEFSSs), on the other hand, use the combination of non-resonant reactive surfaces with capacitive and inductive surface impedances to create distributed-type resonators. For both approaches, the minimum-attainable feature sizes used in the metallic patterns of the structures are the bottleneck of achieving high quality-factor resonators. In practice, the minimum gap spacing and trace widths are determined by the minimum feature size that can be reliably fabricated using standard PCB lithography techniques. Therefore, achieving very high-quality factors and accordingly narrowband frequency responses for both configurations is rather challenging.
Temperature Controlled Dispersion of Carbon Nanotubes in Water with Pyrene-Functionalized Poly(N-cyclopropylacrylamide)

Despite their immense potential, the ability to control the dispersion and microstructure of carbon nanotubes remains a hurdle for their widespread use. Poly(N-cyclopropylacrylamide), containing 5 mol % pyrene-bearing repeat units (p-PNCPA), is shown to vary the dispersion state of single-walled carbon nanotubes (SWNTs) in water. This is a thermo-responsive polymer whose conformation changes with temperature, which in turn leads to changes in the nanotube dispersion state. Cryo-TEM micrographs show that SWNTs stabilized using p-PNCPA transitions from a more exfoliated to a more bundled state as the aqueous suspension temperature is raised above the lower critical solution temperature (LCST) of the polymer (approximately 30 degrees C). Viscosity measurements on SWNT/p-PNCPA aqueous suspensions show shear thinning and near Newtonian behavior at 10 and 50 degrees C, respectively. Drying of these suspensions produces composites whose microstructure and electrical conductivity vary with drying temperature. This behavior has significant implications for the processing of carbon nanotubes and tailoring of composite properties. Such stimuli-controlled dispersion of carbon nanotubes could have a variety of applications in nanoelectronics, sensing, and drug and gene delivery systems.
Mutagenesis of the Regulatory Subunit (RIIβ) of cAMP-dependent Protein Kinase IIβ Reveals Hydrophobic Amino Acids That Are Essential for RIIβ Dimerization and/or Anchoring RIIβ to the Cytoskeleton

In neurons cAMP-dependent protein kinase II beta (PKAII beta) is sequestered in the dendritic cytoskeleton because the regulatory subunit (RII beta) of the enzyme is tightly bound by A Kinase Anchor Proteins (AKAPs). The prototypic neuronal anchor protein AKAP75 has a COOH-terminal 22-residue RII beta binding (tethering) site. A key feature of the tethering site is that several amino acids with large aliphatic side chains mediate the high-affinity binding of RII beta. Mutagenesis, recombinant protein expression, and physicochemical characterization were used to investigate the structural basis for the homodimerization and AKAP75 binding activities of RII beta. Several crucial residues are located in an NH2-terminal region that encompasses amino acids 13-36. Substitution of Ala for Leu13 or Phe36 generates monomeric RII beta subunits that cannot bind AKAP75. The results are not due to general misfolding since mutant RII beta monomers bind cAMP and inhibit the catalytic subunit of PKAII beta with the same affinity and efficacy as wild-type RII beta dimers. Moreover, substitution of Ala for Leu12, Val20, Leu21, Phe31, Leu33, or Leu39 and replacement of Leu13 with Ile or Val did not impair the dimerization reaction. Evidently, large hydrophobic side chains of Leu13 and Phe36 play pivotal roles in stabilizing RII beta-RII beta interactions. A secondary consequence of destabilizing RII beta dimers is the loss of intracellular targeting/anchoring capacity because monomers fail to bind AKAP75. Other NH2-terminal residues directly modulate the affinity of RII beta dimers for the AKAP75 tethering site. Replacement of Val20-Leu21 with Ala-Ala produced a dimeric RII beta protein that binds AKAP75 approximately 4% as avidly as wild-type RII beta. It is possible that the aliphatic side chains of Val20 and Leu21 interact with the essential Leu and Ile residues in the AKAP75 tethering region.
An improved counterselectable marker system for mycobacterial recombination using galK and 2-deoxy-galactose

Counterselectable markers are powerful tools in genetics because they allow selection for loss of a genetic marker rather than its presence. In mycobacteria, a widely used counterselectable marker is the gene encoding levan sucrase (sacB), which confers sensitivity to sucrose, but frequent spontaneous inactivation complicates its use. Here we show that the Escherichia coli galactokinase gene (galK) can be used as a counterselectable marker in both Mycobacterium smegmatis and Mycobacterium tuberculosis. Expression of E. coli galK, but not the putative M. tuberculosis galK, conferred sensitivity to 2-deoxy-galactose (2-DOG) in both M. smegmatis and M. tuberculosis. We tested the utility of E. coli galK as a counterselectable marker in mycobacterial recombination, both alone and in combination with sacB. We found that 0.5% 2-DOG effectively selected recombinants that had lost the galK marker with the ratio of galK loss/galK mutational inactivation of approximately 1:4. When we combined galK and sacB as dual counterselectable markers and selected for dual marker loss on 0.2% 2-DOG/5% sucrose, 98.6-100% of sucrose/2-DOG resistant clones had undergone recombination, indicating that the frequency of mutational inactivation of both markers was lower than the recombination frequency. These results establish a new counterselectable marker system for use in mycobacteria that can shorten the time to generate unmarked mutations in M. smegmatis and M. tuberculosis.
Confronting the Environmental Kuznets Curve

T he environmental Kuznets curve posits an inverted-U relationship between pollution and economic development. Kuznets's name was apparently attached to the curve by Grossman and Krueger (1993), who noted its resemblance to Kuznets's inverted-U relationship between income inequality and development. In the first stage of industrialization, pollution in the environmental Kuznets curve world grows rapidly because people are more interested in jobs and income than clean air and water, communities are too poor to pay for abatement, and environmental regulation is correspondingly weak. The balance shifts as income rises. Leading industrial sectors become cleaner, people value the environment more highly, and regulatory institutions become more effective. Along the curve, pollution levels off in the middle-income range and then falls toward pre-industrial levels in wealthy societies. The environmental Kuznets curve model has elicited conflicting reactions from researchers and policymakers. Applied econometricians have generally accepted the basic tenets of the model and focused on measuring its parameters. Their regressions, typically fitted to cross-sectional observations across countries or regions, suggest that air and water pollution increase with development until per capita income reaches a range of $5000 to $8000. When income rises beyond that level, pollution starts to decline, as shown in the "conventional EKC" line in Figure 1. In developing countries, some policymakers have interpreted such results as conveying a message about priorities: Grow first, then clean up. Numerous critics have challenged the conventional environmental Kuznets curve, both as a representation of what actually happens in the development process and as a policy prescription. Some pessimistic critics argue that crosssectional evidence for the environmental Kuznets curve is nothing more than a
Twenty Four-Hour PC-BOSS Air-Monitoring Results from the NETL Fine-Particulate Sampling Site in Pittsburgh, Pennsylvania: An Annual Perspective

The concentration and composition of PM 2.5 from May to September of 2000 and monthly trends in ambient fine-particulate material concentrations from October 1999 through December 2000 at the National Energy Technology Laboratory's airmonitoring site in Pittsburgh are reported. Twenty four-hour integrated samples were collected using the Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS), a multichannel integrated diffusion denuder sampler designed for routine determination of the chemical composition of ambient particulate matter. The fine-particulate pollutants determined were sulfate estimated as ammonium sulfate, nonvolatile organic material, semivolatile organic material lost from particles during sampling, elemental carbon, nitrate estimated as ammonium nitrate, including ammonium nitrate lost from particles during sampling and elemental content determined by PIXE (for a limited number of samples). Episodes with elevated sulfate and organic material (both semivolatile a...
STEROID EFFECTS ON LUNG COLLAGEN (C) AND ELASTIN (E) ARE DEPENDENT ON GESTATIONAL AGE

C and E, the major lung structural proteins, increase as a fraction of dry lung weight throughout development. Since connective tissue metabolism is known to be effected by corticosteroids, we sought to determine the effect of antenatal exposure to betamethasone (B) on the C and E content of the lungs of prematurely delivered fetal rabbits. Pregnant does were injected with either saline (control) or B (0.2 mg/kg) at 48 and 24 hours prior to sacrifice which was at 24, 27, or 29 days gestation (term = 31). Fetuses were delivered by hysterotomy and weighed, after which their lungs were removed and lyophilized. E was isolated from aliquots of dried lungs by hot alkali digestion. Total lung hydroxyproline (OH-PRO) and E OH-PRO were determined by a colorometric assay and expressed as ug OH-PRO/100 mg dry lung. The difference between these two values was taken as a measure of lung C. C (ug OH-PRO/100 tag dry lung) in control fetuses increased from a mean of 262 at 24 days to 375 at 29 days (p<.01). Over the same period, E (ug OH-PRO/100 mg dry lung) increased from a mean of 4 to 11 (p<.01). Note that a steroid effect was demonstrated at 24, 27, and 29 days by a decrease in body weight (vs. controls) of 25%, 34%, and 33% respectively. At 24 days B increased C by 25% and E by 100%; at 27 days B increased C by 20% but had little effect on E; at 29 days B had little effect on C or E. These preliminary results suggest that steroid effects on lung connective tissue are significant but only at certain gestational ages.
Nebular versus Stellar Wind Abundances in NGC 6543

An early analysis of Chandra observations of the planetary nebula NGC 6543 suggested that the location and the derived temperature for the X‐ray–emitting region are inconsistent with the abundances measured for this object. We revisit Chandra observations of this source (following significant updates to both the reprocessing and extraction software) in order to propose a resolution to this apparent anomaly. Our reanalysis using abundances found from observations in the infrared, optical, and ultraviolet suggests that the location and temperature of the X‐ray emission from NGC 6543 is consistent with nebular abundances expected for the source.
Photolabile micropatterned surfaces for cell capture and release

A method for capture and release of cells was developed using a photolabile linker and antibody-attached glass surface with a poly(ethylene glycol) (PEG)-pattern.
Analysis of diurnal patterns in winter precipitation across the conterminous United States

Abstract Hourly winter (November–March) precipitation data were assembled for nearly 5000 stations in the conterminous United States over the period 1948–98. Despite a potential observation bias in the 24th hour, a general tendency for winter precipitation events was found to occur more frequently near sunrise than for any other time of the day. Based on the standardized amplitude of the first harmonic wave, the pattern is most pronounced in Texas and in an area surrounding Colorado and Wyoming. The pattern also appears significant in the southeastern United States and in northern California based on the variance explained by the first harmonic fit. It is suggested that the diurnal patterns seen in the conterminous United States are related to increased relative humidity values occurring near sunrise and increased wind speeds in the warm sector of cyclonic storms.
EFFECT OF CAVERNOUS NERVE FREEZING ON PROTEIN AND GENE EXPRESSION OF NITRIC OXIDE SYNTHASE IN THE RAT PENIS AND PELVIC GANGLIA

AbstractPurpose: Cryoablation of the prostate has been reported to induce impotence as a result of cavernous nerve injury. This study is designed to investigate the early and late effects of cavernosal nerve cryoablation on erectile function and nitric oxide synthase (NOS) containing nerves in the rat penis and pelvic ganglia.Materials and Methods: Forty male rats were divided into two groups (n = 20 each). The first group underwent unilateral cavernous nerve freezing (experimental group). Before their euthanization at 1 and 3 months (10 rats each), erectile function was assessed by electrostimulation of the cavernous nerves. The second group served as a control and was euthanized at the same time points. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was used to identify NOS in the penile nerve fibers of the mid-shaft segment and neurons of the pelvic ganglia. Western blot, RT-PCR and immunostaining techniques were used to identify protein and gene expression of eNOS, iNOS, and n...
A note on computing graph closures

Abstract This note shows that the k -closure of a graph can be computed in time proportional to the size of the output, improving on previous O( n 3 ) algorithms.
Effect of uncompensated resistance on the cyclic voltammetric response of an electrochemically reversible surface-attached redox couple: Uniform current and potential across the electrode surface

Abstract The effect of uncompensated resistance, Ru, on the cyclic voltammetric response of an electrochemically reversible surface-attached redox couple is quantified using simulation. When current density and interfacial potential are uniform across the electrode surface, the shift in the peak potential, Epeak − E0′, the peak current, ipeak, and uncompensated resistance, Ru, can be correlated by a simple, general, empirical expression: E peak - E 0 ′ i peak R u ≅ 2 - exp - 2.61 2 nF RT E peak - E 0 ′ - 0.764 . When the value of (nF/RT)∣Epeak − E0′ ∣ ⇒ 0, (Epeak − E0′)/ipeakRu ⇒ 2; when the value of (nF/RT)∣Epeak − E0′∣ ⇒ ∞ the value of (Epeak − E0′)/ipeakRu ⇒ 1.0; these limiting values are independent of the double layer capacitance, Cdl. For intermediate values this expression is adequately accurate as long as RTCdl/n2F2Γ total ⩽ 0.1.
μ-Opioid agonist-stimulated [35S]GTPγS binding in guinea pig hypothalamus: effects of estrogen

Abstract μ-Opioid receptors play a critical role in the regulation of the female reproductive cycle, and estrogen modulates the coupling of μ-opioid receptors to a potassium channel in the basal hypothalamus (BH) of the female guinea pig. Therefore, we ascertained the distribution of μ-opioid receptors in the BH with autoradiography using the μ-opioid selective agonist [ 3 H ]DAMGO. In addition, we investigated the effects of estrogen on DAMGO- or the GABAB receptor agonist baclofen-stimulated [ 35 S ]GTPγS binding in the BH. Based on the high density of μ-opioid receptors, but the lack of effects of estrogen on [ 35 S ]GTPγS binding, we conclude that μ-opioid receptor interaction with its G-protein is not the target of estrogen's actions.
Demonstration of proteins in electrophoresis gels using radioactive stains

We describe the use of 35S-labelled stains for the detection of submicrogram amounts of protein in SDS polyacrylamide gels. Many stains used to detect protein can be rendered radioactive, and proteins can be detected by radiofluorography due to stain binding in the absence of visible color. Of the stains tested. [35S]Ponceau Red S and [35S]Serva Blue R gave the best results. The potential utility of protein detection with radioactive stains is discussed.