cssi/SciSciGPT-SciSciNet huggingface dataset:
Mining Ribozyme-Based Insulators for Incorporation into Genetic not Gates

A synthetic transcriptional circuit is assembled from individually well-characterized genetic circuit parts. The combined behavior, however, is still hard to predict from the functions of individual parts. One reason is that neighboring genetic sequences can affect part function. Ribozymes are self-cleaving RNAs, and can be used to insulate the interference that occurs at promoter/5′-UTR junctions in post-transcriptional stages. We mined ribozyme-based insulators that consist of two parts: a ribozyme that insulates the promoter/5′-UTR junction and an additional hairpin located immediately downstream from the ribozyme that insulates the 5′-UTR/RBS. Ribozymes are considered to be good insulators if they make circuit element function independent from upstream as well as downstream components. We tested two genes, GFP and CI-GFP, transcribed by two different promoters, pTac and pLlacO-1. We show promoter-independence from downstream elements by the linearized relationship between GFP expression and CI-GFP expression under the same promoter. Subsequently, we observe overlapping linearized relationships for two different promoters, indicating that the circuit is decoupled from upstream elements. With this assay, we mined 16 effective ribozyme-based insulators. To incorporate them into genetic circuits, we assign unique combinations of ribozymes, repressors, and terminators to generate unique NOT gates. We then characterized the input-output relationship for these insulated NOT gates.
Impulsivity and substance abuse: What is the connection?

The role of impulsivity in substance abuse has recently received increased attention from both researchers and clinicians. Although past studies and treatment primarily focused on compulsive aspects of substance use associated with craving, it is becoming apparent that impulsivity is also a factor i
Two basic wave propagation problems for the non-uniform motion of displacement discontinuities across a bimaterial interface

Abstract The splitting of laminated materials is often achieved by, in effect, moving more rigid solids through the material or by causing a shear tearing characterized by the relative slip of adjacent material points. Both processes may take place across the bimaterial interfaces of the laminate. Moreover, both processes involve the motion of displacement discontinuities. This article examines basic wave propagation problems for the non-uniform motion of two arbitrary displacement discontinuities in perfectly-bonded half-planes along paths normal to the interface. The discontinuities impose relative displacements which are, respectively, normal to and along the path. Complete solutions are derived in forms which allow identification of each component of the reflection and transmission-complicated wave pattern. The dependence of these components on specific aspects of the discontinuity behavior can be noted. Finally, two physical examples, the motions of a rigid wedge and an edge dislocation across the interface are studied. It is found that the singularity order and direction of characteristic stresses can be affected by crossing the interface.
Interference analysis status and plans for aeronautical mobile airport communications system (AeroMACS)

• Need to establish practical limits on AeroMACS transmissions from airports so that the threshold of interference into MSS and other C-band systems is not exceeded • Enable the development of standards under RTCA SC-223 • Analyses have been started with Visualyse, a powerful and flexible interference analysis software tool. • Visualyseresults with omni-directional antenna transmitters agree very well with results from MITRE-CAASD. • Near term plans to improve model realism with multi-sector antennas and subscriber stations.
Effect of Temperature on Crossingover in Heterozygous T5-6c With Homozygous Inversion in Chromosome 5 in Maize

1. Heterozygous T5-6c with homozygous inversion in chromosome 5 has been used to study the effect of exposure to 36±2°F on crossingover.2. Crossingover frequency has been calculated by ascertaining directly the frequency of the crossover quartet.3. Data on the effect of exposure of heterozygous T5-6c with homozygous inversion in chromosome 5 to 36±2°F have been presented.4. The presence of an inversion increased the frequency of chains from 40% to 60%.5. The period of maximum response to the influence of low temperature exposures is 4-6 day period in the 5th week. The increase in crossover frequency is from 10.6% to 12.9% almost approaching the maximum limit of 13.2%.6. It has been suggested that the effect of low temperature on crossingover is through its influence on interference.The writer wishes to express his deep appreciation of Dr. C. R. Burnham for his continued interest, kind criticism and many helpful suggestions during the earlier course of this investigation. He is thankful to him for the stocks he made available for research. To Dr. A. O. Dahl of the Department of of Botany, University of Minnesota the writer is indebted for constructive crticism during the later course of this investigation.
An Isolated Data Acquisition System for High Voltage Applications

This report describes the design and operation of a microcomputer controlled system for acquisition of both analog and binary data within the high voltage stages of a linac modulator. The system is comprised of a microprocessor Controller which communicates with the remote data Acquisition circuits via an optical bus. The bus, which uses a 1 MHz Manchester II format, is configured as a loop, starting at the Controller, daisy-chaining the remote cards and terminating back at the Controller. Upon receiving a linac timing pulse, the Controller sends addressed commands to the individual remote cards and receives data back. It then passes this data to the linac control system through a Multibus connection. Each remote circuit can return 16 binary sense and 7 (12 bit) analog parameters within 270 us. This speed is possible because of a pipelined design where one word is transmitted while another is being converted. A data conversion cycle is initiated when a remote data acquisition card receives the proper command and address from the controller.
Derivation Of Requirements For Calibrating The Advanced X-Ray Astrophysics Facility (AXAF) Telescope

The Advanced X-ray Astrophysics Facility (AXAF) will be a 15-year lifetime observatory, intended to investigate the nature of celestial objects and physical processes, and to study the history and evolution of the universe. We are investigating how to translate the requirements for scientific measurements (e.g., fluxes, spectra and sizes of sources) into operational requirements for the calibration of the AXAF X-ray mirrors and scientific instruments. We carry out a complete simulation of the process of acquiring data from an X-ray source, and analyze the data using various calibration errors. We generate an ideal spectrum of an X-ray source and convolve it with hypothetical "true" mirror and instrument responses to simulate an expected spectrum. This spectrum may be randomized, independently, a large number of times to simulate the effects of photon statistics. These data are analyzed as if they were actual flight data. We introduce controlled perturbations in the mirror and instrument responses used in the analysis. Such perturbations may include: the neglect of extended X-ray absorption fine structure (EXAFS), errors in the jump of absorption coefficients across atomic shell energies, changes in the optical constants of mirror coatings, effects of dust contamination, or arbitrary calibration measurement errors. We perform x2 fits, and assess the changes in the fitted results from those resulting when the data are analyzed with the "true" mirror and instrument responses. In this paper we discuss an initial study of exponential energy spectra with galactic absorption. We assume perfect detector response and consider only the effects of errors in the on-axis effective area of the mirror.
Five-year neurodevelopmental outcome of neonatal dehydration.

Objective To determine the long-term outcome of neonatal dehydration. Study design We identified 182 newborns who were rehospitalized with dehydration (weight loss ≥12% of birth weight and/or serum sodium ≥150 mEq/L) and 419 randomly selected controls from a cohort of 106,627 term and near-term infants with birth weight ≥2000 g born between 1995 and 1998 in northern California Kaiser Permanente hospitals. Outcomes data were obtained from electronic records, interviews, questionnaire responses, and neurodevelopmental evaluations performed in a masked fashion. Results Follow-up data to age at least 2 years were available for 173 of 182 children with a history of dehydration (95%) and 372 of 419 controls (89%) and included formal evaluation at a mean age (±standard deviation) of 5.1 ± 0.12 years for 106 children (58%) and 168 children (40%), respectively. None of the cases developed shock, gangrene, or respiratory failure. Neither crude nor adjusted scores on cognitive tests differed significantly between groups. There was no significant difference between groups in the proportion of children with abnormal neurologic examinations or neurologic diagnoses. Frequencies of parental concerns and reported behavior problems also were not significantly different in the 2 groups. Conclusions Neonatal dehydration in this managed care setting was not associated with adverse neurodevelopmental outcomes in infants born at or near term.
An introduction to geocatalysis

Abstract Heterogeneous catalysis at mineral surfaces, or geocatalysis, may be important in natural systems. This contribution reviews how catalyst may influence reactions and several examples, mostly taken from the geochemical literature, are presented to illustrate the most important concepts. Two key characteristics that define a catalyst are activity and selectivity. Activity is the extent to which the catalyst can facilitate the rate of conversion of reactant to product. The selectivity of the catalyst refers to the ability of a catalyst to facilitate a specific reaction pathway where a reaction may proceed via multiple pathways. Photocatalysis is presented as a separate class of catalysis because reactions are only catalyzed when the system is illuminated with light of suitable wavelength. Three mechanisms of photocatalysis (photolysis, photoelectrochemical reaction, and charge injection) are discussed. Geocatalysis is particularly important for reactions with high activation energies, such as isotopic exchange reactions involving SO 4 –H 2 S, H 2 O–SO 4 , H 2 O–PO 4 , CO 2 –CH 4 and transformations of humic acids and kerogen. While photocatalysis is limited to surficial aquatic environments, it may be of great importance in regulating the concentrations of redox-sensitive elements in the photic zones of lakes, streams, hot spring, and oceans. Photoelectrochemical reactions, such as the reduction of dinitrogen and carbon dioxide are thought to have been important in the origin of life on Earth. Geocatalysis may also prove to be useful in designing new environmental remediation technologies. For example, it is shown that sphalerite and ilmenite are capable of degrading chlorinated carbon compounds via a photocatalytic mechanism.
Balloon angioplasty of coarctation of the aorta evaluated with intravascular ultrasound imaging

Abstract Intravascular ultrasound images were employed to evaluate aortic coarctation before and after balloon angioplasty. Measurements obtained with use of an ultrasound imaging catheter correlated well with measurements made with digital aortography, both in the area of coarctation and in areas proximal and distal to it. The intravascular ultrasound images dramatically revealed dissection of the aortic wall and an intimal flap that was not appreciated on cineaortography or digital subtraction angiography. Intravascular ultrasound imaging may yield important morphologic information unavailable by other imaging techniques. Such information may allow more precise definition of the results of intravascular procedures and improve understanding of lesion characteristics predictive of a successful outcome.
Spectral Intensity and Lineshape Measurements in the First Overtone Band of HF Using Tunable Diode Lasers.

Abstract High-resolution absorption lineshapes for theP(3) andP(6) transitions of the first overtone (v= 2–0) band of HF at 296 K have been measured using a pair of distributed feedback diode lasers operating near 1.31 and 1.34 μm, respectively. Spectral line intensities and self-broadening parameters were determined by fitting the measured spectra with Voigt, Galatry, and Rautian lineshape models. Voigt profiles fit the low-pressure (
Biomass and decay rates of roots and detritus in sediments of intermittent Coastal Plain streams

Biomass and breakdown of tree roots within streambed sediments were compared with leaf and wood detritus in three Coastal Plain headwater intermittent streams. Three separate riparian forest treatments were applied: thinned, clearcut, and reference. Biomass of roots (live and dead) and leaf/wood was significantly higher in stream banks than in the channel and declined with depth strata (0–10 > 10–20 > 20–30 cm). Riparian roots (live and dead combined) contributed on average 24 and 42% of coarse particulate organic matter (CPOM) biomass within the top 30 cm of channel and streambank sediments, respectively. Estimated mean surface area of live riparian roots within sediments was 1084 cm2 m−3. Streambed temperatures showed greater fluctuation at the clearcut site compared to thinned and reference treatments. However, breakdown rates among buried substrate types or riparian treatments did not differ after 1 y. Slow decay rates were associated initially with anaerobic conditions within sandy sediments and later with dry sediment conditions. Riparian roots represent a direct conduit between streamside vegetation and the hyporheic zone. In addition to contributing to organic matter storage, the abundance of riparian roots within streambed sediments suggests that roots play an important role in biogeochemical cycling within intermittent headwater streams of the Coastal Plain.
Collision-induced decay of metastable baby Skyrmions

Many extensions of the standard model predict heavy metastable particles which may be modeled as solitons (Skyrmions of the Higgs field), relating their particle number to a winding number. Previous work has shown that the electroweak interactions admit processes in which these solitons decay, violating the standard model baryon number. We motivate the hypothesis that baryon-number-violating decay is a generic outcome of collisions between these heavy particles. We do so by exploring a $(2+1)$-dimensional theory which also possesses metastable Skyrmions. We use relaxation techniques to determine the size, shape, and energy of static solitons in their ground state. These solitons could decay by quantum-mechanical tunneling. Classically, they are metastable: only a finite excitation energy is required to induce their decay. We attempt to induce soliton decay in a classical simulation by colliding pairs of solitons. We analyze the collision of solitons with varying inherent stabilities and varying incident velocities and orientations. Our results suggest that winding-number violating decay is a generic outcome of collisions. All that is required is sufficient (not necessarily very large) incident velocity; no fine-tuning of initial conditions is required.
Random Mating before Selfing in Maize BC1 Populations

In maize (Zea mays L.) inbred development programs, F 2 and BC 1 populations between two inbreds are usually not random-mated before selfing. Previous results suggest random mating is not useful in F 2 populations. A one-locus model, however, suggests random mating increases the genetic variance by 50% in a BC 1 population without affecting the population means. The objective of this study was to determine the effect of random mating on the testcross means and variances of BC 1 populations. Random-mated and nonrandom-mated backcross populations were developed for two genetic backgrounds, Iowa Stiff Stalk Synthetic (BSSS) and non-BSSS. Testcrosses of these four populations were evaluated at five locations in Minnesota and Wisconsin in 2002. For grain yield, grain moisture, plant height, ear height, root lodging, and stalk lodging, the differences between testcross means of random-mated and nonrandom-mated populations were not significant (P = 0.05), as expected. Testcross variances tended to increase with random mating for most traits in the two genetic backgrounds, but none of these differences was significant. Testcross means of the best 10% families did not differ significantly between random-mated and nonrandom-mated populations. Overall, the results indicated that random mating before selfing in BC 1 populations is not useful in applied breeding programs.
Immunization Policy in Korea

accepted 12 February, 2008 Correspondence : Jong Koo Lee, M.D., Ph.D. Korea Centers for Disease Control and Prevention, Seoul, Korea, 194. Tongul Lo, Eunpyung-Go, Seoul, 122-701 Tel : 82-2-380-2600, Fax : 82-2-388-4601 E-mail : docmohw@mohw.go.kr 으로 인식되어 각국에서는 일정 수준의 예방접종률을 유 지하기 위해 강제성을 가지고 예방접종을 실시하고 있으 며, 최근에는 전세계적인 두창, 조류 인플루엔자의 위협으 로 인해 백신의 비축, 확보 등을 국가 안보의 측면에서 중요하게 다루고 있다. 그러나 이러한 백신 정책의 수립 및 수행에는 체계적 이고 종합적인 접근이 필요하다. 즉, 필수적인 백신의 생 산, 조달, 분배와 이를 위한 시설 및 장비, 효과적인 예방 접종, 취약계층의 접종, 예방접종을 위한 재원 조달, 예방 접종을 위한 인력 및 조직, 체계의 개발과 그 운영, 예방 접종률의 산출과 예방접종 대상 전염병의 발생 등 여러 분야에 있어서 다양한 정책이 요구되는 것이다. 이에 본고에서는 우리나라 예방접종의 역사, 예방접종 의 각 단계별 국내 현황 및 정책 방향 등에 대해 기술하 였다. 종 설
Genetic characterization of feline calicivirus strains associated with varying disease manifestations during an outbreak season in Missouri (1995–1996)

Feline calicivirus (FCV) is a common cause of mild to severe upper respiratory tract disease (URTD) in cats. FCV strain 21223 was isolated from a kitten with severe pneumonia in a disease outbreak with unusually high mortality (35 %) that occurred in a Missouri feline colony in 1995–1996. Phylogenetic analysis of the genome sequence of strain 21223 indicated the emergence of a new FCV strain. Analysis of the full-length genome sequence of a closely related (99.5 % nucleotide identity) strain, 3786, obtained from an asymptomatic animal in the same colony four months later, showed the presence of seven amino acid substitutions, with six of them located in the VP1 capsid sequence encoded by ORF2. Comparative analysis of the E-region sequences (426–521 aa ORF2) presumably involved in virus-host cell receptor interactions did not identify amino acid substitutions unique to the virulent strain. We determined the complete genome sequences of four virus isolates that were collected in regional catteries in the months following the outbreak that were associated with different manifestations of the disease (URTD, chronic stomatitis, and gingivitis). We show that genetically distinct FCV strains were cocirculating in the area, and no apparent correlation could be made between overall sequence and observed disease.
Targeted Therapy in Gliomas

The survival outcome of patients with malignant gliomas is still poor, despite advances in surgical techniques, radiation therapy and the development of novel chemotherapeutic agents. The heterogeneity of molecular alterations in signaling pathways involved in the pathogenesis of these tumors contributes significantly to their resistance to treatment. Several molecular targets for therapy have been discovered over the last several years. Therapeutic agents targeting these signaling pathways may provide more effective treatments and may improve survival. This review summarizes the important molecular therapeutic targets and the outcome of published clinical trials involving targeted therapeutic agents in glioma patients.
Solving fractional packing problems in Oast(1/ε) iterations

We adapt a method proposed by Nesterov [16] to design an algorithm that computes e-optimal solutions to fractional packing problems by solving O*(e-1 √Kn) separable convex quadratic programs, where K is the maximum number of non-zeros per row and n is the number of variables. We also show that the quadratic program can be approximated to any degree of accuracy by an appropriately defined piecewise-linear program. For the special case of the maximum concurrent flow problem on a graph G =(V,E) with rational capacities and demands we obtain an algorithm that computes an E-optimal flow by solving O*(e-1K3/2|E| √|V| (log 1/e+ LU + LD)) shortest path problems, where K is the number of commodities, and LU, LD are, respectively, the number of bits needed to store the capacities and demands. We also show that the complexity of computing a maximum multicommodity flow is O*(1/elog2(1/e)). In contrast, previous algorithms required Ω(e-2) iterations.
Phylogenetic diversity of drinking water bacteria in a distribution system simulator

Aims: To characterize the composition of microbial populations in a distribution system simulator (DSS) by direct sequence analysis of 16S rDNA clone libraries. Methods and Results: Bacterial populations were examined in chlorinated distribution water and chloraminated DSS feed and discharge water. Bacterial strains isolated from DSS discharge water on R2A medium were identified using 16S rDNA sequence analysis. The majority of the bacteria identified were α-proteobacteria, ranging from approx. 34% in the DSS discharge water to 94% of the DSS isolates. Species richness estimators Chao1 and ACE (abundance-based coverage estimators) indicated that the chlorinated distribution water sample was representative of the total population diversity, while the chloraminated DSS feed water sample was dominated by Hyphomicrobium sp. sequences. The DSS discharge water contained the greatest diversity of α-, β-, γ-proteobacteria, with 36% of the sequences being operational taxonomic units (OTUs, sequences with >97·0% homology). Conclusions: This work demonstrated the dominance of α-proteobacteria in distribution system water under two different disinfectant residuals. The shift from chlorine to monochloramine residual may have played a role in bacterial population dynamics. Significance and Impact of the Study: Accurate identification of bacteria present in treated drinking water is needed in order to better determine the risk of regrowth of potentially pathogenic organisms within distribution systems.
Unramified elements in cycle modules

Let X be an algebraic variety over a field F. We study the functor taking a cycle module M over F to the group of unramified elements M(F(X))nr of M(F(X)). We prove that this functor is represented by a cycle module. The existence of pull-back maps on M(F(X))nr for rational maps (under a mild condition) is established. An application to the R-equivalence on classifying varieties of algebraic groups is given.
Spin microscopy's heritage, achievements, and prospects.

Achieving 3-dimensional, in-depth, atomic-resolution biological microscopy of undenatured specimens is one of the oldest dreams of science, and for good reason: it unites the thrilling prospect of opening vast new scientific frontiers with cutting-edge technical challenges from every domain of mathematics, science, and engineering.
Insights from the Crop Insurance Reform Act of 1994

A survey was conducted to study the factors affecting crop insurance purchase and coverage, to identify the sources of risk in farming, and to determine the impact of policy changes on risk management for designing new educational programs. The survey results show that the new 1994 crop insurance program has been effective in increasing the insured pool of farmers, though it has not yet gained wide acceptance among the farming communities in Nebraska. Risks associated with price uncertainties turned out to be very important in the opinion of farmers. Knowledge of farmers about the futures market influenced the selection of appropriate marketing tools and aid in managing price risks. The new crop insurance program has been effective in communicating to the farming community that future ad hoc disaster payments are unlikely. © 1997 John Wiley & Sons, Inc.
On the proof of the reciprocity law for arithmetic Siegel modular functions

Earlier we obtained a new proof of Shimura’s reciprocity law for the special values of arithmetic Hilbert modular functions. In this note we show how from this result one may derive Shimura’s reciprocity law for special values of arithmetic Siegel modular functions. To achieve this we use Shimura’s classification of the special points of the Siegel space, Satake’s classification of the equivariant holomorphic imbeddings of Hilbert-Siegel modular spaces into a larger Siegel space, and, finally, a corrected version of some of Karel’s results giving an action of the Galois group Gal(Qab/Q) on arithmetic Siegel modular forms.
Banking lessons from the past: The 1938 regulatory Agreement interpreted

We show that the interagency 1938 Uniform Agreement on Bank Supervisory Procedures set the precedent for dynamically varying supervisory standards to conform to national macroeconomic policies and political agendas. Our evidence indicates that the conferences leading to the Agreement were motivated and dominated by the Federal Reserve. Contrary to the goals of the other banking agencies, the Fed sought greater leniency in bank examination in order to stimulate bank credit creation. This precedent for softening examination standards was paralleled in 1991–1992 when the administration and regulatory agencies attempted to offset a proclaimed “credit crunch” by subordinating bank examinations to the perceived need for more bank credit. The implied risk of trading off bank safety for short-lived economic policies merits more open national debate.
Modeling the Effects of Fire Severity and Spatial Complexity on Small Mammals in Yosemite National Park, California

We evaluated the impact of fire severity and related spatial and vegetative parameters on small mammal populations in 2 yr- to 15 yr-old burns in Yosemite National Park, California, USA. We also developed habitat models that would predict small mammal responses to fires of differing severity. We hypothesized that fire severity would influence the abundances of small mammals through changes in vegetation composition, structure, and spatial habitat complexity. Deer mouse (Peromyscus maniculatus) abundance responded negatively to fire severity, and brush mouse (P boylii) abundance increased with increasing oak tree (Quercus spp.) cover. Chipmunk (Neotamias spp.) abundance was best predicted through a combination of a negative response to oak tree cover and a positive response to spatial habitat complexity. California ground squirrel (Spermophilus beecheyi) abundance increased with increasing spatial habitat complexity. Our results suggest that fire severity, with subsequent changes in vegetation structure and habitat spatial complexity, can influence small mammal abundance patterns.
Nuclear actin-related proteins as epigenetic regulators of development

Complex regulatory networks control cell fate and the development of organs and tissues in multicellular organisms. But what mechanisms initiate the necessary global changes in patterns of gene expression? What regulates the regulators of organismal development? The nuclear actin-related proteins (
Fibrin sheaths and central venous catheter occlusions: diagnosis and management.

Central venous catheter malfunction diagnosis and treatment is a growing component of the field of interventional radiology. A thorough understanding of the causes of catheter malfunction and the technical skills needed to treat these problems are necessities to appropriate management. In long-standing central venous catheters, the formation of a fibrin sheath can and often does contribute to catheter malfunction. Differentiating a sheath from thrombus is imperative to appropriate therapy. The purpose of this article is to provide an understanding of the causes of fibrin sheaths and how to treat them.
A template RNA entry channel in the fingers domain of the poliovirus polymerase.

Positive-strand RNA viruses within the Picornaviridae family express an RNA-dependent RNA polymerase (3Dpol) that is required for viral RNA replication. Structures of 3Dpol from poliovirus, coxsackievirus, human rhinoviruses, and other picornaviruses reveal a putative template RNA entry channel on the surface of the enzyme fingers domain. Basic amino acids and tyrosine residues along this entry channel are predicted to form ionic and base stacking interactions with the viral RNA template as it enters the polymerase active site. We generated a xseries of alanine substitution mutation sat these residues in the poliovirus polymerase and assayed their effects on template RNA binding, RNA synthesis initiation, rates of RNA elongation, elongation complex stability, and virus growth. The results show that basic residues K125, R128, and R188 are important for template RNA binding while tyrosines Y118 and Y148 are required for efficient initiation of RNA synthesis and for elongation complex stability. Alanine substitutions of tyrosines 118 and 148 at the tip of the 3Dpol pinky finger drastically decreased the rate of initiation as well as elongation complex stability, but without affecting template RNA binding or RNA elongation rates. Viable poliovirus was recovered from HeLa cells transfected with mutant RNAs; however, mutations that dramatically inhibited template RNA binding (K125A-K126A and R188A), RNA synthesis initiation (Y118A, Y148A), or elongation complex stability (Y118A, Y148A) were not stably maintained in progeny virus. These data identify key residues within the template RNA entry channel and begin to define their distinct mechanistic roles within RNA elongation complexes.
Global Climate Change and Local Action: Understanding the Connecticut Policy Trajectory

Climate change is the signature global issue of our time. This is not just because of climate change itself, but also because of the host of socioeconomic and physical impacts that will result from rising temperatures globally. But fundamentally for scholars of international relations, climate change confronts the policy limitations of sovereignty and its implications for global action directly. Because of the lack of effective global and even national climate change policy action, policy initiatives to confront climate change must focus on levels below the global, even though economic models suggest that global policy provision might be the most efficient way to target the implications of climate change. Thus, this study centers on the complexity of climate change policymaking by focusing attention on the evolution of climate change policy action in the New England region, the State of Connecticut, and its municipalities.
Who Visits a National Park and What do They Get Out of It?: A Joint Visitor Cluster Analysis and Travel Cost Model for Yellowstone National Park

Yellowstone National Park visitor data were obtained from a survey collected for the National Park Service by the Park Studies Unit at the University of Idaho. Travel cost models have been conducted for national parks in the United States; however, this study builds on these studies and investigates how benefits vary by types of visitors who participate in different activities while at the park. Visitor clusters were developed based on activities in which a visitor participated while at the park. The clusters were analyzed and then incorporated into a travel cost model to determine the economic value (consumer surplus) that the different visitor groups received from visiting the park. The model was estimated using a zero-truncated negative binomial regression corrected for endogenous stratification. The travel cost price variable was estimated using both 1/3 and 1/4 the wage rate to test for sensitivity to opportunity cost specification. The average benefit across all visitor cluster groups was estimated at between $235 and $276 per person per trip. However, per trip benefits varied substantially across clusters; from $90 to $103 for the “value picnickers,” to $185–$263 for the “backcountry enthusiasts,” $189–$278 for the “do it all adventurists,” $204–$303 for the “windshield tourists,” and $323–$714 for the “creature comfort” cluster group.
Observational estimates of detrainment and entrainment in non-precipitating shallow cumulus

Abstract. Vertical transport associated with cumulus clouds is important to the redistribution of gases, particles, and energy, with subsequent consequences for many aspects of the climate system. Previous studies have suggested that detrainment from clouds can be comparable to the updraft mass flux, and thus represents an important contribution to vertical transport. In this study, we describe a new method to deduce the amounts of gross detrainment and entrainment experienced by non-precipitating cumulus clouds using aircraft observations. The method utilizes equations for three conserved variables: cloud mass, total water, and moist static energy. Optimizing these three equations leads to estimates of the mass fractions of adiabatic mixed-layer air, entrained air and detrained air that the sampled cloud has experienced. The method is applied to six flights of the CIRPAS Twin Otter during the Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) which took place in the Houston, Texas region during the summer of 2006 during which 176 small, non-precipitating cumuli were sampled. Using our novel method, we find that, on average, these clouds were comprised of 30 to 70 % mixed-layer air, with entrained air comprising most of the remainder. The mass fraction of detrained air was usually very small, less than 2 %, although values larger than 10 % were found in 15 % of clouds. Entrained and detrained air mass fractions both increased with altitude, consistent with some previous observational studies. The largest detrainment events were almost all associated with air that was at their level of neutral buoyancy, which has been hypothesized in previous modeling studies. This new method could be readily used with data from other previous aircraft campaigns to expand our understanding of detrainment for a variety of cloud systems.
Synarchy and the Chinese People: A Plea for Internationalization in Warlord China

In the wake of a major mutiny by warlord forces in 1921 that left much of the Yangzi port city of Yichang in ruins, a group of Chinese citizens appealed to the foreign diplomatic community to turn the city into a foreign concession under foreign protection. In a statement that seems shocking in the context of the burgeoning anti-imperialist sentiment that followed the May 4th incident of 1919, the petitioners concluded that if their wish was granted, “they would make no complaint, even if we become slaves without nationality.” This incident suggests that in at least some cases many Chinese did not hesitate to make common cause with the foreigners in their midst against a mutual threat. The article seeks to retrofit John King Fairbank’s concept of synarchy to explain how the Chinese people may have both perceived and negotiated the uneven and interpenetrated power relations of the central government, warlord authorities, and foreign powers in the Republican era.
Magnesium hydroxide: new insights into the mechanism of its laxative effect and the potential involvement of prostaglandin E2.

The mechanism by which Mg(OH)2 acts as a laxative is unknown. To explore the mechanism, six volunteers more than 55 years old, with normal bowel habits, were enrolled in a dose-response, randomized, placebo-controlled, double-blind, crossover design study. Each subject was studied for four inpatient periods of 5 days each on a metabolic ward with 9 days off of all medication between studies. In the hospital, all patients were on a diet fixed in calories, fluid volume, Na+, fiber, and Ca2+. At 8 p.m. on each study day, each subject took 45 ml containing either placebo or 1,200, 2,400, or 3,600 mg of Mg(OH)2 plus 240 ml of water. On the fourth and fifth hospital days of each period, 24-h stool output was quantified and analyses performed. Compared to placebo, Mg(OH)2 caused the following dose-dependent results: (a) increased number of bowel movements; (b) increased percentage of stool water; (c) increased stool volume; (d) increased stool Mg2+; and (e) increased total stool 24-h prostaglandin E2 (PGE2), with mean 24-h excretions as follow: placebo, 95 +/- 18 pg/24 h; 1,200 mg Mg(OH)2, 260 +/- 100; 2,400 mg Mg(OH)2, 357 +/- 117; and 3,600 mg Mg(OH)2, 525 +/- 196. There was a significant correlation between stool PGE2 excretion and stool water consistent with a causative relationship. However, the concentration of stool prostaglandin was lower than the concentration found to alter intestinal electrolyte transport in vitro. In summary, the laxative effect of Mg(OH)2 is associated with increased output of stool PGE2. The contribution of the stool PGE2 to the laxative effect of Mg(OH)2 is unknown.
THE COMPLEXITY OF RIEMANN SURFACES AND THE HURWITZ EXISTENCE PROBLEM

\noindent The \emph{complexity} of a branched cover of a Riemann surface $M$ to the Riemann sphere $S^2$ is defined as its degree times the hyperbolic area of the complement of its branching set in $S^2$. The \emph{complexity} of $M$ is defined as the infimum of the complexities of all branched covers of $M$ to $S^2$. We prove that if $M$ is a (connected, closed, orientable) Riemann surface of genus $g \geq 1$, then its complexity equals $2\pi(m_{\text{min}}+2g-2)$, where $m_{\text{min}}$ is the minimum total length of a branch datum realizable by a branched cover $p \colon M \to S^2$. DOI: 10.1017/S0004972712000469
Dynamic indices of methamphetamine dependence and HIV infection predict fluctuations in affective distress: a five-year longitudinal analysis.

Background Methamphetamine (METH) use and human immunodeficiency virus (HIV) infection are highly comorbid, and both are associated with increased prevalence of affective distress. Delineating the trajectory of affective distress in the context of METH dependence and HIV infection is important given the implications for everyday functional impairment, adverse health behaviors, and increased risk for adverse health outcomes.
Examining the Nature and Magnitude of Intradistrict Resource Disparities in Mid‐Size School Districts

While a growing research base has examined resource disparities across schools within large school districts, the literature has largely overlooked resource allocation in the mid-size school districts that a large portion of the nation's children attend. In this paper, we measure disparities in teacher resources within four New York State districts and conclude that intradistrict equity is not just a big city problem. We also explore the budgeting processes and mechanisms leading to these disparities, including fund-based budgeting, grant-based allocation rules, class size formulae, and ad-hoc mechanisms. We conclude with policy implications and recommendations for improving intradistrict resource equity.
Design of spectrally tailored fusion reactor materials experiments in the HFIR RB∗ capsule irradiation facility☆

Design of four spectrally tailored capsules to irradiate magnetic fusion energy (MFE) materials specimens in the new High Flux Isotope Reactor (HFIR) removable beryllium (RB∗) facility at temperatures of 60, 200, 330 and 400°C, is described. These designs incorporate provisions for removal, examination and reencapsulation of the specimens at intermediate exposure levels en route to a target exposure level of 30 displacements per atom (dpa). With the exception of the 60°C capsule, where the test specimens are in direct contact with the reactor cooling water, the specimen temperatures (monitored by 21 thermocouples) are controlled by varying the thermal conductance of a small gap region between the specimen holder and the containment tube. Hafnium shields are used to tailor the neutron spectrum to closely match the helium production-to-atom displacement ratio (14 appmdpa) expected in an austenitic stainless steel fusion reactor first wall. These MFE capsule irradiations will begin in early 1988.
Identification and characterization of a hunchback orthologue, Lzf2, and its expression during leech embryogenesis.

Abstract Lzf1andLzf2are leech zinc finger (Lzf) genes that are shown to be orthologues to theDrosophilagap genehunchback(hb). Neitherin situhybridization nor RT–PCR detectedLzf1transcripts in leech embryos or adults.Lzf2expression was examined in leech embryos at various stages byin situhybridization.Lzf2is expressed continually throughout the early embryonic cleavage divisions, including the period during which the embryo forms stem cells that will give rise to the segmented tissues of the adult. At the time of segmental pattern formation,Lzf2RNA is expressed uniformly along the length of the segmented trunk in both the ectodermal and mesodermal tissues. This is in contrast to the anteriorly restricted gradient ofhbRNA shown to be critical to the normal anteroposterior (AP) patterning of the insect embryo. Thus, this leech orthologue ofhbdoes not appear to play a comparable role in the patterning of the AP axis. In addition,Lzf2is expressed during organogenesis in segmentally restricted patterns in the central nervous system, the gut, and epidermally derived structures.Lzf2is the firsthborthologue to be characterized in detail outside of insects and its expression pattern suggests thathbmay have acquired a gap gene function in arthropods or insects after their phyletic separation from the annelids.
Educating New York's Bilingual Children: Constructing a Future from the Past.

This paper describes the ways in which New York City schools have responded to the multilingualism of its children in the last 40 years, and suggests changes needed in order to accommodate the greater linguistic heterogeneity of the city. In the predominantly Puerto Rican community of the 1960s and 1970s, traditional bilingual education programs were the best way to educate language minority children. But in the twenty-first century, with the demographic shifts and the technological advances of a globalized world, other understandings of bilingualism in education are needed. The paper ends by suggesting ways in which traditional bilingual education may exist alongside other more dynamic approaches of bilingualism in education that consider the city's growing linguistic heterogeneity, thus constructing a future from the past.
Lowest Singlet and Triplet States of Copper, Silver, and Gold Trihydrides: an ab Initio Study

The lowest singlet and triplet electronic states of CuH3, AgH3, and AuH3 were studied. The molecular parameters were optimized at the coupled cluster singles doubles level augmented with perturbative correction for connected triple excitation (CCSD(T)). The equilibrium geometric structures of the lowest singlet states are Y-shaped, with very small values for the valence HMH angle. The T-shaped and linear conformations are found to be transition structures. The electronic density and vibrational mode analysis indicates that these molecules can be considered as adducts of a H2 molecule to the corresponding monohydrides. The lowest triplet states lie ∼25 000−29 000 cm-1 above the minimum of the singlet state. The equilibrium geometry structures of the lowest triplet states are pyramidal with small inversion barriers.
Quantitative studies of nonlinear second sound in superfluid 4He.

Experimental studies of the nonlinear evolution in time of planar second-sound pulses in superfluid $^{4}\mathrm{He}$ have been carried out at temperatures 2 to 25 mK below ${\mathit{T}}_{\ensuremath{\lambda}}$. The pulse evolution in helium is compared to solutions of the Burgers equation, and corrections for the effect of the heater and bolometer substrates are made by numerical integration of the heat-diffusion equation with appropriate boundary conditions. Agreement between measured and calculated pulse shapes is found to be excellent. Fits to the data of the model are used to obtain the linear second-sound velocity. A new method for studying the critical behavior of second sound very close to ${\mathit{T}}_{\ensuremath{\lambda}}$, where nonlinear effects are always important, is suggested.
Hydroxyapatite films on silicon single crystals by a solution technique: texture, supersaturation and pH dependence

Thick films of hydroxyapatite (HA) were deposited on silicon single crystal wafers placed in close proximity to a plate of apatite- and wollastonite-containing glass and dipped into a simulated physiological solution at 36°C. Amorphous calcium phosphate phase present in the glass leached into the solution, causing supersaturation of Ca2+ and PO4 3- ions. Spherical cap-like islands of calcium phosphate nucleated on Si crystals and grew in size with time. The thickness of the film grown on Si (111) in a solution having a composition similar to that of human blood plasma, and maintained at pH of 7.2, reached 7.1 μm in 336 h, compared with a thickness of 12.7 μm when the ion concentrations of the solution were doubled. HA films grown on Si (111) showed strong (102) texture. In contrast, hardly any HA film could be grown on Si (100). With increasing pH value of the solution the Ca/P ratio of the film increased. At a pH of 7.2 the as-grown and annealed (at 800°C for 3 h in argon) films had Ca/P ratios of 1.10 and 1.72, respectively. The Vickers hardness and the adhesion strength of the film increased upon annealing. Our results suggest that the driving force for formation of apatite films arises from the lowering of free energy of the supersaturated solution by deposition of ions (Ca, P, O, H) in certain crystallographic arrangements on suitable substrates with low interface energies.
The current that kills: Some shocking facts about electricity that deserve notice

Statistics show that over one thousand people are killed in electrical accidents every year in the United States. Approximately 15 percent of these accidents occur in industry. A larger percentage are electrocuted in the home.
Tackling adaptive corruptions in multicast encryption protocols

We prove a computational soundness theorem for symmetric-key encryption protocols that can be used to analyze security against adaptively corrupting adversaries (that is, adversaries who corrupt protocol participants during protocol execution). Our soundness theorem shows that if the encryption scheme used in the protocol is semantically secure, and encryption cycles are absent, then security against adaptive corruptions is achievable via a reduction factor of O(n ċ (2n)l), with n and l being (respectively) the size and depth of the key graph generated during any protocol execution. Since, in most protocols of practical interest, the depth of key graphs (measured as the longest chain of ciphertexts of the form Ɛk1 (k2), Ɛk2 (k3), Ɛk3 (k4), ...) is much smaller than their size (the total number of keys), this gives us a powerful tool to argue about the adaptive security of such protocols, without resorting to non-standard techniques (like non-committing encryption). We apply our soundness theorem to the security analysis of multicast encryption protocols and show that a variant of the Logical Key Hierarchy (LKH) protocol is adaptively secure (its security being quasi-polynomially related to the security of the underlying encryption scheme).