cssi/SciSciGPT-SciSciNet huggingface dataset:
Software Quality Attributes

Software quality has many facets, including verifiability, robustness, maintainability, reusability, and understandability. One concern of requirements engineering is the ranking of these quality attributes in order of importance for the particular software system under consideration, keeping in mind that the most important quality attribute is user acceptance. Special emphasis is given to software performance estimation.
Always on the Edge of the Next Big Storm, the Next Big Spill, Always Vulnerable: An Interview With Bayou Interfaith Shared Community Organizing.

In this interview, Sharon and David Gauthe of Bayou Interfaith Shared Community Organizing (Thibodaux, Louisiana) document their personal experiences with adverse health outcomes that seem connecte...
Paleoindian Colonization by Boat? Refining the Coastal Model

Many archaeologists now generally accept the idea that Paleoindians initially entered the Americas traversing the northwestern coastline possibly in conjunction with an ice-free corridor, and arriv...
Assessment of a quantitative mammographic imaging marker for breast cancer risk prediction

The purpose of this study is to assess feasibility of applying a new quantitative mammographic imaging marker to predict short-term breast cancer risk. An image dataset involving 1,044 women was retrospectively assembled. Each woman had two sequential “current” and “prior” digital mammography screenings with a time interval from 12 to 18 months. All “prior” images were originally interpreted negative by radiologists. In “current” screenings, 402 women were diagnosed with breast cancer and 642 remained negative. There is no significant difference of BIRADS based mammographic density ratings between three case groups (p >0.6). A new computer-aided image processing scheme was applied to process negative mammograms acquired from the “prior” screenings and compute image features related to the bilateral mammographic density or tissue asymmetry between the left and right breasts. A group of 30 features related to GLCM texture features and a conventional computer-aided detection scheme generated results are extracted from both CC and MLO views. Using a leave-one-case-out cross-validation method, a support vector machine model was developed to produce a new quantitative imaging marker to predict the likelihood of a woman having mammography-detectable cancer in the next subsequent (“current”) screening. When applying the model to classify between 402 positive and 642 negative cases, area under a ROC curve is 0.70−0.02 and the odds ratios is 6.93 with 95% confidence interval of [4.80,10.01]. This study demonstrated feasibility of applying a quantitative imaging marker to predict short-term cancer risk, which aims to help establish a new paradigm of personalized breast cancer screening.
Online Content-Focused Coaching to Improve Classroom Discussion Quality.

In this article, the authors report results from two pilot studies (n = 15 teachers total) investigating the effectiveness of the Online Content-Focused Coaching (CFC) programme for increasing clas...
NgAgo-enhanced homologous recombination in E. coli is mediated by DNA endonuclease activity

ABSTRACT Prokaryotic Argonautes (pAgos) have been proposed as more flexible tools for gene-editing as they do not require sequence motifs adjacent to their targets for function, unlike popular CRISPR/Cas systems. One promising pAgo candidate, from the halophilic archaeon Natronobacterium gregoryi (NgAgo), however, has been subject to intense debate regarding its potential in eukaryotic systems. Here, we revisit this enzyme and characterize its function in prokaryotes. NgAgo expresses poorly in non-halophilic hosts with the majority of protein being insoluble and inactive even after refolding. However, we report that the soluble fraction does indeed act as a DNA endonuclease. Structural homology modelling revealed that NgAgo shares canonical domains with other catalytically active pAgos but also contains a previously unrecognized single stranded DNA binding domain (repA). Both repA and the canonical PIWI domain participate in DNA cleavage activities. We also found that these endonuclease activities are essential for enhanced NgAgo-guided homologous recombination, or gene-editing, in E. coli. Collectively, our results provide insight into the poorly characterized NgAgo for subsequent gene-editing tool development and sheds new light on seemingly contradictory reports.
The load as a controllable energy asset in dc microgrids

In a traditional power grid system, the operator had total control of generation and distribution assets while the load was viewed as a disturbance. Thus, planning and operation necessitated always being prepared for unforeseen changes in the load consumption. The result is that the US power grid is amazingly resilient, robust, and expensive. As we consider a new paradigm of dc microgrid systems, overcapacity may not be feasible for technological and/or economic reason. Yet, high power quality and availability is more important than ever particularly to support the digital economy and information age. This is compounded as renewable sources become increasingly utilized, and the system operator no longer has total and arbitrary control of the generation. In this chapter, we introduced a framework for load control in a LAPES. In this paradigm, the load is considered to be an energy asset which can be controlled not just by the end user but also by the system. As such, a new degree of freedom is introduced in the control problem of balancing electrical supply and demand. Key to implementing any of these concepts is to strike the balance between the opportunity and cost, which would provide the techno-economic trade-off needed to implement these concepts practically. Important application-specific design considerations are the desired energy availability and the price willing to be paid for that availability as well as the tolerable amount of control relinquished. Optimizing this is not straightforward and may lead to solutions that change with time and conditions. To anticipate this, the chapter discussed the concept of load prioritization and a method to change the allowable control of the load.
Conditional Recurrence-Free Survival after Resection of Colorectal Liver Metastases: Persistent Deleterious Association with RAS and TP53 Co-Mutation.

Background Conditional recurrence-free survival (RFS) probability, that is, the probability of remaining recurrence-free after a given interval without recurrence, has not been reported after resection of colorectal liver metastases (CLMs). We aimed to estimate conditional RFS and identify factors affecting conditional RFS. Study Design Patients undergoing initial resection of CLMs during 2000-2016 with mutation data were identified. The RFS and risk factors for recurrence were evaluated at the time of resection for all patients and at 1 year and 2 years after resection for patients who remained recurrence-free. Results Of 2,118 patients, 485 met the inclusion criteria, of which 225 were recurrence-free at 1 year and 109 were recurrence-free at 2 years. The 5-year RFS rates were 17.3%, 36.8%, and 70.7% for all patients and the 1-year and 2-year recurrence-free groups, respectively, when assessed from the time of initial CLM resection. RAS/TP53 co-mutation was the only factor independently associated with increased risk of recurrence for all groups (all patients, hazard ratio 1.47; 95% CI 1.19 to 1.82; p Conclusions Conditional RFS is useful for updating prognosis after a given time interval without recurrence after CLM resection. Importantly, RAS/TP53 co-mutation has a persistent deleterious association with recurrence.
A Process of Transitioning to the New ABET Criterion 3: An IT Degree Program's Approach

This talk discusses an effective and efficient process that a BSIT program has undergone for transitioning to the new ABET Student Outcomes and some preliminary results, which may benefit other computing programs in preparation for an ABET accreditation visit in 2019 or beyond.
In Vivo Anterior Cruciate Ligament Deformation During a Single-Legged Jump Measured by Magnetic Resonance Imaging and High-Speed Biplanar Radiography.

Background:The in vivo mechanics of the anterior cruciate ligament (ACL) and its bundles during dynamic activities are not completely understood. An improved understanding of how the ACL stabilizes...
An approximate solution of the interferon-dependent viral kinetics model of influenza

Abstract The analysis of viral kinetics models is mostly achieved by numerical methods. We present an approach via a Magnus expansion that allows us to give an approximate solution to the interferon-dependent viral infection model of influenza which is compared with numerical results. The time of peak viral load is calculated from the approximation and stays within 10% in the studied range of interferon (IFN) efficacy ϵ ∈ [0, 1000]. We utilize our solution to interpret the effect of varying IFN efficacy, suggesting a competition between virions and interferon that can cause an additional peak in the usually exponential increase in the viral load.
5 – Belief Systems

Publisher Summary This chapter describes the belief systems. It presents the work on naive physics, everyday reasoning, and decision theory, and discusses the borderline status that belief occupies between the cognitive and affective domains. It presents a characterization of pure empiricism based on a collection of empirical axioms and a model for predicting the sequence of hypotheses students would test on simple straightedge-and-compass construction problems. Though the model captured the students' actions fairly well at the behavioral level, its description of the causes for the students' behavior was far too simplistic; the model was based on an avowed empiricism, and there is not compelling evidence to believe that students openly and actively reject the value of mathematical argumentation. The chapter explains such behavior, that is, called as naive empiricism. In principle, the development of naive empiricism in geometry is similar to the development of, for example, naive physics. Naive empiricism is just one example of the ways that people's behavior is shaped by their beliefs about the nature of mathematics. This is an issue of some generality, with broad implications.
Nicola Hoggard Creegan and Andrew Shepherd (eds.), Creation and Hope: Remections on Ecological Anticipation and Action from Aotearoa New Zealand

Nicola Hoggard Creegan and Andrew Shepherd (eds.), Creation and Hope: Remections on Ecological Anticipation and Action from Aotearoa New Zealand (Eugene: Pickwick Publications, 2018), 230pp., $22.40 (pbk), ISBN: 978153260973.
Valid Statistical Analysis for Logistic Regression with Multiple Sources

Considerable effort has gone into understanding issues of privacy protection of individual information in single databases, and various solutions have been proposed depending on the nature of the data, the ways in which the database will be used and the precise nature of the privacy protection being offered. Once data are merged across sources, however, the nature of the problem becomes far more complex and a number of privacy issues arise for the linked individual files that go well beyond those that are considered with regard to the data within individual sources. In the paper, we propose an approach that gives full statistical analysis on the combined database without actually combining it. We focus mainly on logistic regression, but the method and tools described may be applied essentially to other statistical models as well.
Voluntary Turnover in Nonprofit Human Service Organizations: The Impact of High Performance Work Practices

Voluntary turnover in nonprofits can present a significant cost, reducing the performance of a nonprofit and challenging its sustainability over time. This study examines voluntary turnover in a sample of human service (HS) nonprofit organizations in eight states, exploring the relationship between the implementation of high performance work practices (HPWP) and voluntary turnover. The findings demonstrate that certain HPWPs, including onboarding, leadership development, compensation, and employee relations, are associated with lower voluntary turnover. The results suggest that human service nonprofits seeking to improve retention should invest more time and resources in developing employees as future leaders and cultivating a positive working environment.
Non–High-Density Lipoprotein Cholesterol Versus Apolipoprotein B in Cardiovascular Risk Stratification : Do the Math

With the emergence of new lipid risk markers and a growing cardiometabolic risk burden in the United States, there is a need to better integrate residual risk into cardiovascular disease (CVD) risk stratification. In anticipation of the Adult Treatment Panel IV (ATP IV) guidelines from the National Cholesterol Education Program (NCEP), there exists controversy regarding the comparative performance of the 2 foremost markers, apolipoprotein B (apoB) and non–high-density lipoprotein cholesterol (non–HDL-C), as they relate to the current standard of risk assessment and treatment: low-density lipoprotein cholesterol (LDL-C). Although some emerging markers may demonstrate better performance compared with LDL-C, certain fundamental characteristics intrinsic to a beneficial biomarker must be met prior to routine use. Collectively, studies have found that non–HDL-C and apoB perform better than LDL-C in CVD risk prediction, both on- and off-treatment, as well as in subclinical CVD risk prediction. The performance of non–HDL-C compared with apoB, however, has been a point of ongoing debate. Although both offer the practical benefits of accuracy independent of triglyceride level and prandial state, non–HDL-C proves to be the better marker of choice at this time, given established cutpoints with safe and achievable goals, no additional cost, and quick time to result with an easy mathematical calculation. The purpose of this review is to assess the performance of these parameters in this context and to discuss the considerations of implementation into clinical practice.
Self-retaining barbed suture for parenchymal repair during laparoscopic partial nephrectomy; initial clinical experience.

Objectives To evaluate the efficacy of a self-retaining barbed suture (SRBS) in achieving a secure and haemostatic renorrhaphy during laparoscopic partial nephrectomy (LPN). To compare perioperative outcomes for LPN with SRBS with those for LPN with conventional polyglactin suture, with specific attention to warm ischaemia time, blood loss and need for postoperative bleeding interventions. Patients and methods Patients who underwent LPN between June 2007 and October 2010 were identified through an Institutional Review Board approved registry of oncological patients. Before July 2009, parenchymal repair after tumour excision was performed using absorbable polyglactin suture (Group 1), and subsequently, using SRBS (Group 2). Demographic, clinical, intraoperative and postoperative outcomes were compared for each group. Results LPN was performed in 49 patients in Group 1 and 29 in Group 2. Baseline demographic and clinical features, estimated blood loss, and transfusion and embolization rates were statistically similar for the cohorts. Mean warm ischaemia time (±SD) was significantly shorter for the SRBS group (26.4 ± 8.3 vs 32.8 ± 7.9; P= 0.0013). Bleeding requiring intervention (open conversion or transfusion ± embolization) was more common for Group 1 (9/49, 18.4% vs 1/29, 3.4%; P= 0.06). Conclusions The use of SRBS for parenchymal repair during LPN in humans is safe and is associated with a significant reduction in warm ischaemia time. SRBS use during LPN may also reduce rates of clinically significant bleeding. Prospective, larger studies to confirm the value of SRBS use in minimally invasive partial nephrectomy are warranted.
Performance analysis of a receiver directed CDMA packet radio network

A multihop packet radio network using receiver-directed code-division multiple access (CDMA) is considered. The network is modeled as a system of interacting queues, and sufficient conditions for the stability of the queueing system model are obtained. Under an independence assumption, approximate results for the mean packet delay in a symmetric network are given. The results are used to characterize the throughput-delay performance of a symmetric network using frequency-hop spread-spectrum signalling. >
Ethanol production from sorghum by a microwave-assisted dilute ammonia pretreatment.

Abstract The efficiency of a batch microwave-assisted ammonia heating system was investigated as pretreatment for sweet sorghum bagasse and its effect on porosity, chemical composition, particle size, enzymatic hydrolysis and fermentation into ethanol evaluated. Sorghum bagasse, fractionated into three particle size groups (9.5–18, 4–6 and 1–2 mm), was pretreated with ammonium hydroxide (28% v/v solution) and water at a ratio of 1:0.5:8 at 100, 115, 130, 145 and 160 °C for 1 h. Simon’s stain method revealed an increase in the porosity of the biomass compared to untreated biomass. The most lignin removal (46%) was observed at 160 °C. About 90% of the cellulose and 73% of the hemicellulose remained within the bagasse. The best glucose yields and ethanol yields (from glucose only) among all different pretreatment conditions averaged 42/100 g dry biomass and 21/100 g dry biomass, respectively with 1–2 mm sorghum bagasse pretreated at 130 °C for 1 h.
An application of membrane inlet mass spectrometry to measure denitrification in a recirculating mariculture system.

The detrimental effects of aquaculture waste discharges require development of recirculating and/or pretreatment systems. Denitrification, in combination with nitrification, removes fixed nitrogen from culture water in recirculating systems. Three experiments were conducted to measure denitrification rates in biofilter media (“bioballs”) and sediments from a recirculating mariculture system. In this case, “sediments” refer to solids accumulated at the bottom of the biofilter. Bioballs and sediments were collected from the biofilter attached to a 3.7 m diameter shrimp culture tank. Dissolved dinitrogen and oxygen concentrations were calculated from N2/Ar and O2/Ar ratios measured with a membrane inlet mass spectrometer (MIMS) optimized for high precision analysis of dissolved gases in water. Denitrification and oxygen flux were calculated from concentration changes as culture water passed through experimental chambers containing bioballs or sediments. Rates are reported per liter of inflow water flowing through the chambers, rather than per hour, because flow rates and biofilter design vary among aquaculture systems. Mean denitrification rates were 22.5±3.8 and 93.6±2.9 μmol N l−1 (n=6) in bioball and sediment chambers, respectively. Denitrification removed 1.0±0.4% and 3.9±0.3% of the total nitrogen (less N2) passing through bioball and sediment chambers, respectively. Ammonium accumulated in sediment chambers at 27.0±5.4 μmol N l−1, but ammonium flux in bioball chambers was not different from zero. Nitrite accumulation rates in bioball and sediment chambers were 20.8±7.8 and 24.0±2.4 μmol N l−1, respectively. The nitrate removal rate from sediment chambers was 115±35.4 μmol N l−1, but nitrate accumulated in bioball chambers at a rate of 76.8±16.6 μmol N l−1. The data showed that sediments accumulated in biofilters were important sites of nitrogen removal in this system. However, ammonium accumulation and nitrate removal in sediment chambers suggest that dissimilatory nitrate reduction to ammonium (DNRA) may be an important process in sediments accumulated in biofilters. The occurrence of DNRA in biofilters would result in less efficient removal of fixed N. MIMS technology has been used in many analytical chemistry applications but recently was identified as a useful tool for measuring denitrification in natural systems. This work is the first known application of MIMS technology to aquaculture issues and offers advantages over other methods to estimate denitrification in aquaculture systems.
Making compiler design relevant for students who will (most likely) never design a compiler

Compiler Design courses are a common component of most modern Computer Science undergraduate curricula. At the same time, however, compiler design has become a highly specialized topic, and it is not clear that a significant number of Computer Science students will find themselves designing compilers professionally. This paper argues that the principles, techniques, and tools discussed in compiler design courses are nevertheless applicable to a wide variety of situations that would generally not be considered to be compiler design. Generalizing the content of compiler design courses to emphasize this broad applicability can make them more relevant to students.
Thermomechanical Analytical 3D Thermal/Stress Estimation Sidewall Grinding Model

A general three-dimensional thermal/stress grinding model, based on thermal and elastic/plastic classical analytical solutions, has been developed in this paper. The thermal model can predict the temperature distribution of surface and cylindrical external/internal creep-feed or conventional grinding for vertical or inclined sidewall surface grinding. This paper deals with a grinding burn problem that is widespread in the aerospace and automotive industries. The thermal model is compared with sidewall surface grinding experiments. The comparison of the temperature distribution results is expected. The general stress model has been developed, which combines both spherical and cylindrical coordinates. In addition, the 3D thermal/stress model is compared with four cases of external cylindrical grinding experiments. The residual stresses agree reasonably.
High-speed multispectral fluorescence lifetime imaging implementation for in vivo applications

Fluorescence lifetime imaging microscopy (FLIM) offers a noninvasive approach for characterizing the biochemical composition of biological tissue. In recent years, there has been an increasing interest in the application of multispectral FLIM for medical diagnosis. Central to the clinical translation of FLIM technology is the development of robust, fast, and cost-effective FLIM instrumentation suitable for in vivo tissue imaging. Unfortunately, the predominant multispectral FLIM approaches suffer from limitations that impede the development of high-speed instruments for in vivo applications. We present a cost-effective scanning multispectral FLIM implementation capable of achieving pixel rates on the order of tens of kilohertz, which will facilitate the evaluation of FLIM for in vivo applications.
Mathematical Prediction of Dynamic Tire Behavior

The subject of the problems and progress in predicting the mechan- ical behavior of tires subjected to dynamic loading is treated in two parts. The difficulties associated with this problem and various methods that have been pro- posed for its treatment are first discussed. The application of finite element tech- niques is emphasized, both with respect to current success and future potential. The second part presents a detailed analysis of this same problem using classical membrane theory. Although the model is developed using the same basic considera- tions employed by earlier investigators, its final formulation provides for greater generality and flexibility in application. It has the capability of defining meridian profiles and, consequently, cord strains under a condition of inflation and centrifugal loading as a function of geometric and cord load parameters designated at any point on the tire carcass. The result is a method of analysis which can be easily applied to study the effects of a variety of tire design and constructional constraints on carcass shape and cord tensions.
Effect of piezoelectric grain size on magnetoelectric coefficient of Pb(Zr0.52Ti0.48)O3–Ni0.8Zn0.2Fe2O4 particulate composites

This study investigates the variation of magnetoelectric (ME) coefficient as a function of the piezoelectric grain size in the composite system of 0.8 Pb(Zr0.52Ti0.48)O3–0.2 Ni0.8Zn0.2Fe2O4. It was found that as the piezoelectric-phase grain size increases the overall resistivity, piezoelectric, dielectric, and ferroelectric property of the composite increases and saturates above 600 nm. Below 200 nm average grain size, piezoelectric and dielectric properties decrease rapidly. The ferroelectric Curie temperature was found to decrease from 377 to 356 °C as the average grain size decreases from 830 to 111 nm. ME coefficient of the composite showed a rapid change below grain size of 200 nm and was found to saturate above 600 nm to a value of 155 mV/cm.Oe.
Adhesion effects in material transfer in mechanical contacts

Abstract A series of molecular dynamics simulations of the contact and separation of a surface with an asperity (material A) and a flat substrate (material B) are performed, in which the A/B interfacial energies vary (leaving other properties unchanged). When the work of adhesion Γ is large, substantial plastic deformation occurs on separation, and some material is transferred to the opposing substrate. When Γ is small, separation of the materials occurs at a critical force, with no material transfer and no plastic deformation. A theory is developed, based upon a capillary equilibrium argument, that accurately predicts when material transfer from one surface to another will occur. When separation occurs without plastic deformation, the separation process can be described by Johnson, Kendal and Roberts (JKR) adhesive contact theory. The simulation results and theory clarify how interfacial adhesion can be manipulated to control surface roughening, material transfer and surface alloying in contacts.
Issue Salience and Bill Introduction in the House and Senate

I propose that many if not most bills introduced in the House and Senate represent electoral position taking on the part of members. Thousands of bills are introduced every year, only a fraction of which are passed into law, much less seriously considered in the chamber. Moreover, bills are very good position-taking devices in that they can appear to voters to be a credible step in the electoral process. I search for electoral motivations by examining the content of the bills members introduce. For five different policy areas, and in both the House and the Senate, I find strong correlations between indicators of issue salience in members’ districts and the number of bills the member introduces within the policy area. In addition, in the House the relationship between salience and bill introduction is strongest among vulnerable members, although in the Senate vulnerability does not influence the relationship.
The oxidation state of DJ-1 regulates its chaperone activity toward α-synuclein

DJ-1 has been reported to have chaperone activity by preventing the aggregation of some proteins, and by structural analogy to Hsp31. The L166P mutation has been linked to a familial early onset form of Parkinson's disease (PD). Since the aggregation of α-synuclein is believed to be a critical step in the etiology of PD, we have investigated the interaction of wild-type DJ-1 and its oxidized forms with α-synuclein. Native (unoxidized) DJ-1 did not inhibit α-synuclein fibrillation, and no evidence for stable interactions between α-synuclein and native DJ-1 was observed. However, DJ-1 is very susceptible to oxidation by the addition of two oxygen atoms to form the sulfinic acid of Cys106 (2O DJ-1) (no 1O oxidized state is detectable). 2O DJ-1 was readily prepared by the addition of H2O2 at concentrations up to a 20-fold molar excess. The oxidation of Cys106 to the sulfinic acid had minimal effect on the structural properties of DJ-1. However, 2O DJ-1 was very effective in preventing the fibrillation of α-synuclein, and only this form of DJ-1 appears to have significant anti-aggregation properties against α-synuclein. Further oxidation of DJ-1 leads to loss of some secondary structure, and to loss of the ability to inhibit α-synuclein fibrillation. Our observations confirm the suggestion that DJ-1 may act as an oxidative-stress-induced chaperone to prevent α-synuclein fibrillation. Since oxidative stress has been associated with PD, this observation may explain why mutations of DJ-1 could be a contributing factor in PD, and also indicates that excess oxidative stress could also lead to enhanced α-synuclein aggregation and hence PD.
Optimization of MALDI-TOF MS Detection for Enhanced Sensitivity of Affinity-Captured Proteins Spanning a 100 kDa Mass Range

Analysis of complex biological samples by MALDI-TOF mass spectrometry has been generally limited to the detection of low-mass protein (or protein fragment) peaks. We have extended the mass range of MALDI-TOF high-sensitivity detection by an order of magnitude through the combined optimization of instrument parameters, data processing, and sample preparation procedures for affinity capture. WCX, C3, and IMAC magnetic beads were determined to be complementary and most favorable for broad mass range protein profiling. Key instrument parameters for extending mass range included adjustment of the ADC offset and preamplifier filter values of the TOF detector. Data processing was improved by a combination of constant and quadratic down-sampling, preceded by exponential baseline subtraction, to increase sensitivity of signal peaks. This enhancement in broad mass range detection of protein signals will be of direct benefit in MS expression profiling studies requiring full linear range mass detection.
Torsional vibration control with an MR fluid brake

Analytical and experimental work has been performed on the use of a magneto-rheological (MR) fluid brake for controlling torsional vibrations in rotating systems. In this paper, two different strategies are examined for controlling the MR brake in such applications. First, implementation of the MR fluid brake as a passive friction damper with a variable friction torque is presented. In that application, fixed currents were applied to the electromagnets in the MR brake. As a result, the dominant behavior of the brake was as a dry friction damper whose friction was a function of applied current. The second approach was the implementation of the MR brake in a modified skyhook damping control approach. In that application, the friction in the MR brake was adjusted according to a comparison between the sign of absolute velocity of the primary system and the sign of the relative velocity between the MR brake and the primary system in order to add effective damping to the system. Characterization of the MR brake was an essential part of both control strategies. This work includes the results of system identification performed on the MR fluid brake, along with experimental performance results of the system under the different control strategies.
Yellow–Green Luminosity accompanying the Injection of Triethylborane into the Upper Atmosphere

VALUABLE information about the state and motion of the upper atmosphere can be obtained by the release of various rocket-borne materials which emit light on reaction with the gaseous surroundings at high altitudes. Previously, experimenters have produced luminous clouds by injecting materials such as sodium (ref. 1 and unpublished results of Smith), nitric oxide2,3, aluminium2,4,5 and trimethyl aluminium (TMA) (refs. 6 and 7 and unpublished results of Hoffman and Smith) into the atmosphere at altitudes above 80 km, either at night or during twilight. Injections of aluminium and TMA at twilight have been particularly fruitful because it has been possible to record well resolved spectra of the bluish-green light emitted by AlO molecules formed in the presence of sunlight. Analyses of the spectra have provided estimates of the vibration al temperatures of the gases in the upper atmosphere5.
Transition state structure of 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase from Escherichia coli and its similarity to transition state analogues.

Methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) catalyzes reactions linked to polyamine metabolism, quorum sensing pathways, methylation reactions, and adenine salvage. It is a candidate target for antimicrobial drug design. Kinetic isotope effects (KIEs) were measured on the MTAN-catalyzed hydrolysis of 5‘-methylthioadenosine (MTA) to determine the transition state structure. KIEs measured at pH 7.5 were near unity due to the large forward commitment to catalysis. Intrinsic KIEs were expressed by increasing the pH to 8.5. Intrinsic KIEs from MTAs labeled at 1‘-3H, 1‘-14C, 2‘-3H, 4‘-3H, 5‘-3H, 9-15N, and Me-3H3 were 1.160 ± 0.004, 1.004 ± 0.003, 1.044 ± 0.004, 1.015 ± 0.002, 1.010 ± 0.002, 1.018 ± 0.006, and 1.051 ± 0.002, respectively. The large 1‘-3H and small 1‘-14C KIEs indicate that the Escherichia coli MTAN reaction undergoes a dissociative (DN*AN) (SN1) mechanism with little involvement of the leaving group or participation of the attacking nucleophile at the transition state, causin...
Crystallization and processing behaviour of the polyamide J-1 polymer and composites reinforced with Kevlar fibre

Abstract The influence of thermal processing on the crystalline behaviour of J-1 polymer, a PACM-based polyamide homopolymer used as a matrix for advanced composites, was studied using differential scanning calorimetry (DSC), cross polarized microscopy, wide angle X-ray scattering (WAXS), and dynamic mechanical analysis (DMA). A double melting peak appears in DSC thermograms of neat polymer processed at cooling rates above 60°C min −1 , accompanied by an additional crystallization peak above the glass transition. As the cooling rate is decreased, only a single melting peak occurs. This single peak corresponds to the lower temperature peak of two appearing in fast cooled J-1 polymer. Slower cooling rates produce a more ordered semicrystalline structure in the neat polymer, providing higher tensile strength and greater solvent resistance than the rapidly quenched material. WAXS patterns show the slow cooled J-1 polymer to have higher crystallinity than the quenched material. The equilibrium extent of crystallinity was determined to be about 20%, and the heat of fusion for 100% crystalline material is 150 J g −1 . The density of the crystalline and non-crystalline phases are approximately 1.09 and 1.04 g cm −3 respectively. In order to study the behaviour of the composite, Kevlar fibre tows melt impregnated with J-1 polymer were wound into sheets and laminated into unidirectional composites in an autoclave process. Cracks due to internal stresses appeared in thin composite panels cooled at 10°C min −1 . A thermal expansion differential was determined to be the primary cause of these stresses. By cooling the laminates slowly from the melt temperature, thin, crack-free composite panels were produced by permitting greater stress relaxation of the polymer and decreasing thermal gradients in the laminates.
Distribution of solution in the epidural space: examination by cryomicrotome section.

Abstract Background and Objectives: The routes of distribution and barriers to flow of solutions in the epidural space are incompletely determined. This study examined macroscopic details of epidural injectate spread in postmortem humans by cryomicrotome imaging. Methods: Soon after death, 3 nonembalmed adult human subjects were injected with ink through epidural catheters inserted by standard techniques. Following freezing, microtome sectioning was performed to reveal anatomic features down to 100 [mu ]m. To control for effects of death, an adult baboon was injected during general anesthesia and subsequently examined in the same fashion. Results: Injected ink was readily evident and showed spread as rivulets through numerous small channels rather than as a unified advancing front. The fascia that extends laterally from the posterior longitudinal ligament is an important barrier restricting solution flow. Solution preferentially traveled along the nerve root sheath through the intervertebral foramen. Conclusions: Distribution of solution in the epidural space is nonuniform. Rather than a uniform advancing front, spread is directed among paths between structures according to pressures by which they are compressed. No structural barriers block flow through the intervertebral foramina or spinal canal other than the fascia of the posterior longitudinal ligament. Reg Anesth Pain Med 2002;27:150-156.
DEVIATIONS FROM FERMI-LIQUID BEHAVIOR ABOVE TC IN 2D SHORT COHERENCE LENGTH SUPERCONDUCTORS

We show that there are qualitative differences between the temperature dependence of the spin and charge correlations in the normal state of the 2D attractive Hubbard model using quantum Monte Carlo simulations. The one-particle density of states shows a pseudogap above {ital T}{sub {ital c}} with a depleted {ital N}(0) with decreasing {ital T}. The susceptibility {chi}{sub {ital s}} and the low frequency spin spectral weight track {ital N}(0), which explains the spin-gap scaling: 1/{ital T}{sub 1}{ital T}{similar_to}{chi}{sub {ital s}}({ital T}). However, collective excitations contribute to the charge channel, and the compressibility {ital dn}/{ital d}{mu} is {ital T} independent. This anomalous ``spin-charge separation`` is shown to exist even at intermediate {vert_bar}{ital U}{vert_bar} where the momentum distribution {ital n}(k) gives evidence for a degenerate Fermi system.
Empirical Determination of Rational Method Runoff Coefficients

The rational method for determining peak flood discharges has been used for the design of hydraulic structures for decades. Despite the popularity of the method, little attention has been paid to improving guidance for selection of the runoff coefficient. This study determined rational runoff coefficients (the rational C ) for 72 gauged rural watersheds in Kansas ranging in size from 0.45 to 76.6 km2 using a frequency-based approach. The median rational C values for Kansas ranged from 0.17 for the 2-year recurrence interval in western Kansas up to 0.97 for the 100-year recurrence interval in eastern Kansas. This paper investigates the spatial variation in runoff coefficients and documents the dependence of the rational C on recurrence interval. The rational C values determined in this study do not exhibit dependence on drainage area, indicating that the method is acceptable for use on much larger basins than is typically assumed.
Efficiency differentials in peasant agriculture and their implications for development policies

This paper reviews the theoretical and empirical work on allocative efficiency in traditional agriculture and presents a new study of technical efficiency among Tanzanian cotton farmers. The theoretical arguments are shown to apply primarily in a competitive context that differs significantly from that in which peasant farms operate. Re‐analysis of earlier empirical studies shows that, on average, the marginal value products of inputs differ by more than 40 per cent from the marginal factor costs to which they should be equated under allocative efficiency. Our own study among Tanzanian cotton farmers in Geita District reveals that output could be increased by 51 per cent if all farmers achieved those levels of technical efficiency that were in fact achieved by the best farmers in the sample using the same inputs and technologies that the less efficient used. These results indicate that the efficiency hypothesis may not be applicable to much of peasant agriculture and that development policies might fruitf...
Ca2+ release and contraction induced by IP3 and contractile agonists in mammalian gastric smooth muscle

The source, time course and stoichiometry of cytosolic free Ca2+ ([Ca2+]i) during contraction were examined in smooth muscle cells isolated from the guinea pig and human stomach. Contraction by receptor-linked agonists (eg, acetylcholine, cholecystokinin octapeptide and Met-enkephalin) was preceded by stoichiometric increases in [Ca2+]i and net 45Ca2+ efflux that were maintained in the absence of extracellular Ca2+ or in the presence of a Ca2+ channel blocker (13600). The intracellular Ca2+ store could be depleted by repeated stimulation with all agonists in Ca2+-free medium or in the presence of 13600 resulting in loss of contractile response; response was restored by re-exposure of the cells to Ca2+. The source of intracellular Ca2+ an the signal for its release were examined in saponin-permeabilized muscle cells. The cells retained their ability to contract in response to receptor-linked agonists and developed an ability to contract in response to inositol trisphosphate (IP3). The cells accumulated Ca2+ to the same extent as intact muscle cells, but only in the presence of ATP. IP3 caused a prompt, concentration-dependent increase in contraction, [Ca2+]i and net 45Ca2+ efflux. These effects were maximally similar to those produced by CCK-8 alone or in combination with IP3: Depletion of the Ca2+ store by repeated stimulation of single muscle cells in Ca2+-free medium with IP3, acetylcholine or CCK-8 separately resulted in loss of contractile response to all three agents; the response was restored by re-exposure of the muscle cell to a cytosol-like perfusate (Ca2+ 180 nM). The studies demonstrate that a product of membrane phosphoinositide hydrolysis is capable of mobilizing Ca2+ from a depletable, non-mitochondrial intracellular store that is utilized by receptor-linked agonists. The magnitude of IP3-induced Ca2+ release is correlated with contraction.
Use of cortical circuits during focal penicillin seizures: an autoradiographic study with [14C]deoxyglucose.

Abstract Autoradiography with [ 14 C]deoxyglucose was used to study the architectural pattern of glucose utilization in the motor cortex of rats during focal penicillin seizures. The seizure focus was characterized by a well circumscribed area whose metabolic activity was increased 2–3 times normal. This was tightly surrounded by cortex that was normal or slightly depressed. The posterior third of the focus showed an increase in glucose utilization in a columnar pattern with particular accentuation of activity in lamina V. There was a loss of normal activity in lamina IV within the focus and in somatosensory and occipital cortex far behind the focus. This depression was particularly prominent in the ipsilateral barrel field. Increased metabolic activity was found in a small area in contralateral homotopic cortex, in lamina Vb with columns extending above this from lamina IV to the surface. Glucose utilization was accentuated 1.2–1.8 fold in the ipsilateral secondary somatosensory area, but was normal in the contralateral cortex. The intensity of focal seizures was increased by the intracortical injection of more penicillin or by giving intravenous metrazol. Both of these methods resulted in an increase in the size of the focus as determined with [ 14 C]deoxyglucose. This was most prominent on the lateral border in lamina I–II and V. In addition, there was an accentuation of the columnar pattern in the posterior part of the focus, ipsilateral somatosensory cortex, and contralateral motor cortex. The architectural pattern of glucose utilization in the cortex during focal seizures is discussed with reference to corticocortical, commissural, and corticothalamic circuits that have been identified by others in anatomical studies. Superimposed on this structure are physiological principles of recurrent excitation, lateral spread, and surround inhibition that characterize basic electrophysiological mechanisms of epilepsy, and influence the intensity of activity within the architectural design.
The chemical ecology of Diabroticites and Cucurbitaceae

The coevolutionary association between plants of the family Cucurbitaceae and beetles of the tribe Luperini (Coleoptera: Chrysomelidae; Galerucinae) is mediated to a large extent by chemicals of the host plants. The kairomones involved in host selction by the rootworm beetles are the oxygenated tetracyclic triterpenoid cucurbitacins that act as arrestants and feeding stimulants and a number of volatile cyclic plant blossom components that act as long-range orientation cues. The complex ecological and evolutionary factors regulating the chemical ecology of host-plant selection are discussed.
Reactions of organocopper reagents derived from chloroprene. Conjugate addition and nucleophilic substitution

Abstract Organocopper reagents derived from 2-(1,3-butadienyl) magnesium chloride react regiospecifically with α,β-unsaturated carbonyl compounds to give 1,4-addition products of 2-substituted-1,3-butadienes.
Punishing Images Jail Cam and the Changing Penal Enterprise

This article explores the use of web cameras inside a local penal facility in Phoenix, Arizona through which jail detainees’ daily routines were broadcast on the Internet over a two-year period. I ...
Constructing an organ: the Drosophila salivary gland as a model for tube formation.

Abstract Tubes are required in metazoans to transport the liquids and gases that sustain life. The conservation of molecules and mechanisms involved in tube formation suggests that what we learn by studying simple systems will apply to related processes in higher animals. Studies over the past 10 years have revealed the molecules that specify cell fate in Drosophila salivary gland and the cellular events that mediate tube morphogenesis. Here, we discuss how anterior–posterior and dorsal–ventral patterning information specifies both the position of salivary-gland primordia and how many cells they contain. We examine the transformation of a polarized epithelial sheet into an elongated, unbranched tube, and the intrinsic and extrinsic factors that influence the final position of the salivary gland.
Correlating observations of deformation microstructures by TEM and automated EBSD techniques

The evolution of the deformed microstructure as a function of imposed plastic strain is of interest as it provides information on the material hardening characteristics and mechanism(s) by which cold work energy is stored. This has been extensively studied using transmission electron microscopy (TEM), where the high spatial and orientational resolution of the technique is used in advantage to study local phenomenon, such as dislocation core structures and interactions of dislocations. With the recent emergence of scanning electron microscope (SEM)-based automated electron backscatter diffraction (EBSD) techniques, it has now become possible to make mesoscale observations that are statistical in nature and complement the detailed TEM observations. Correlations of such observations will be demonstrated for the case of Ni-base alloys, which are typically non-cell forming solid solution alloys when deformed at ambient temperatures. For instance, planar slip is dominant at low-strain levels but evolves into a microstructure where distinct crystallographic dislocation-rich walls form as a function of strain and grain orientation. Observations recorded using both TEM and EBSD techniques are presented and analyzed for their implication on subsequent annealing characteristics.