cssi/SciSciGPT-SciSciNet huggingface dataset:
The origin of selectivity in the conversion of glucose to fructose and mannose in Sn-BEA and Na-exchanged Sn-BEA zeolites

Abstract We investigate the isomerization and epimerization of glucose to fructose and mannose in Sn-BEA and Na-exchanged Sn-BEA using density-functional theory calculations on periodic BEA crystals. We compare reaction pathways both in the absence and presence of water molecules in the vicinity of the active site and find that water effectively determines the selectivity in Na-Sn-BEA. We identify two competing epimerization pathways, one involving direct 1,2-carbon shift and the other involving 1,2-hydride shift via fructose. In Sn-BEA, the isomerization to fructose is the kinetically dominant pathway, while mannose is formed via the indirect 1,2-hydride shift epimerization pathway. In Na-Sn-BEA, the kinetically dominant pathway is epimerization to mannose via the direct 1,2-carbon shift pathway (Bilik mechanism) only in the presence of water solvent in the vicinity of the active site, whereas isomerization is preferred in the absence of water. We argue that polar water molecules that coordinate around the Na cation screen strong electrostatic interactions between Na+ and the glucose backbone that are responsible for the strong inhibition of the 1,2-carbon shift mechanism in the absence of water. In Sn-BEA, the presence of water does not influence the selectivity. Our calculations resolve for the first time the role of water and Na cations in the catalytic activity of Sn-BEA, and rationalize the experimental data.
Investigating the Effect of Bioirrigation on In Situ Porewater Concentrations and Fluxes of Polychlorinated Biphenyls Using Passive Samplers

Polychlorinated biphenyl (PCB) fluxes from contaminated sediments can be caused by mechanisms including diffusion, bioirrigation, and resuspension, but it is often unclear which mechanisms are important. In the Lower Duwamish Waterway (Seattle, Washington), the presence of abundant benthic macrofauna suggests that porewater bioirrigation may be an important mechanism for PCB transport from the bed into the overlying water column. In this field study, the fluxes of PCBs due to bioirrigation were quantified by using (a) polyethylene (PE) samplers to quantify in situ and ex situ (i.e., equilibrium) PCB porewater concentration profiles and (b) measurements of the geochemical tracer 222Rn to quantify the rate of porewater exchange with overlying water. The results showed that bioirrigation caused sorptive disequilibrium with the surrounding sediment, which led to lower in situ porewater concentrations than expected from sediment concentrations. The combined fluxes of seven PCB congeners (Σ7PCBs) were 1.6–26 ng...
Interarea Oscillation Damping Control Using High-Voltage DC Transmission: A Survey

High-voltage direct current (HVDC) transmission lines are increasingly being installed in power systems around the world, and this trend is expected to continue with advancements in power electronics technology. These advancements are also bringing multiterminal direct current (MTDC) systems closer to practical application. In addition, the continued deployment of phasor measurement units makes dynamic information about a large power system readily available for highly controllable components, such as HVDC lines. All these trends have increased the appeal of modulating HVDC lines and MTDC systems to provide grid services in addition to bulk power transfers. This paper provides a literature survey of HVDC and MTDC damping controllers for interarea oscillations in large interconnected power systems. The literature shows a progression from theoretical research to practical applications. There are already practical implementations of HVDC modulation for lines in point-to-point configuration, although the modulation of MTDC systems is still in the research stage. As a conclusion, this paper identifies and summarizes open questions that remain to be tackled by researchers and engineers.
Transient Kinetics and Quantum Yield Studies of Nanocrystalline α-Phenyl-Substituted Ketones: Sorting Out Reactions from Singlet and Triplet Excited States

Recent work has shown that diarylmethyl radicals generated by pulsed laser excitation in nanocrystalline (NC) suspensions of tetraarylacetones constitute a valuable probe for the detailed mechanistic analysis of the solid-state photodecarbonylation reaction. Using a combination of reaction quantum yields and laser flash photolysis in nanocrystalline suspensions of ketones with different substituents on one of the α-carbons, we are able to suggest with confidence that a significant fraction of the initial α-cleavage reaction takes place from the ketone singlet excited state, that the originally formed diarylmethyl-acyl radical pair loses CO in the crystal with time constants in the sub-nanosecond regime, and that the secondary bis(diarylmethyl) triplet radical pair has a lifetime limited by the rate of intersystem crossing of ca. 70 ns.
Primary unifocalization for the absence of intrapericardial pulmonary arteries in the neonate.

The management of the neonate with absence of intrapericardial pulmonary arteries in association with complex intracardiac anomalies presents a challenging surgical problem. The more traditional approach of palliation with unilateral or bilateral systemic–pulmonary artery shunts may result in peripheral pulmonary artery stenoses and uneven distribution of pulmonary blood flow. In addition, this approach may lead to complicated reconstructive procedures necessitating reconstruction of the branch pulmonary artery with prosthetic material, which restricts pulmonary artery growth and often complicates reoperation. To avoid these potential limitations, we have performed primary unifocalization for absence of intrapericardial pulmonary arteries in eight consecutive neonates (median age 9 days) between May 1990 and December 1991. Absence of intrapericardial pulmonary arteries occurred in association with tetralogy of Fallot (n = 4), truncus arteriosus (n = 2), and transposition of the great arteries with pulmonary atresia (n = 2). Four patients had unilateral absence of the right (n = 1) or left (n = 3) intrapericardial pulmonary artery. In the remaining four patients, there was complete absence of both intrapericardial pulmonary arteries. Wide mobilization and excision of all ductal tissue before anastomosis was performed from a midline approach in seven patients. In one patient, a preliminary right thoracotomy was required. Primary unifocalization was performed simultaneously with complete repair in five patients. In the remaining three patients, unifocalization was part of a staged repair and included insertion of a systemic–pulmonary artery shunt to the reconstructed central pulmonary artery confluence. No operative or late cardiac deaths occurred, although one death occurred during subsequent repair of a tracheoesophageal fistula. Three patients underwent reoperation, and only one patient required revision of an anastomotic pulmonary artery stenosis. All survivors were growing normally at 2 to 22 months after operation (mean follow-up 10 months). Our experience suggests that primary reconstruction for the absence of intrapericardial pulmonary arteries can be successfully accomplished in the neonate. This approach provides uniform bilateral pulmonary blood flow, avoids prosthetic material in the branch pulmonary arteries, and may eliminate, or at least simplify, future reconstructive procedures.
Long-Term Studies on the Persistence and Movement of TCDD in A Natural Ecosystem

Field studies of the persistence and movement of 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD) were conducted during 1973- 1979 on a unique 3.0 km2 military test area (Test Area C-52A, Eglin Air Force Base, Florida) that was aerially sprayed with 73,000 kg 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) during the period 1962–1970. Analysis of archived samples of the formulations indicated that approximately 2.8 kg TCDD were applied as a contaminant of the herbicide. However, 2.6 kg of this TCDD were applied to a 37 ha test grid (Grid I) from June 1962 through July 1964. Levels of 10 to 1,500 parts-per-trillion (ppt) could be found in the top 15 cm of soil 14 years after the last application of herbicide on this site. Nevertheless, analysis of 61 soil samples suggested that less than one percent of the TCDD remained on the test area. Photodegradation at the time of and immediately after aerial application probably accounted for much of the disappearance of TCDD, although volatilization, wind and water erosion, and biological removal may have also contributed to its disappearance.
Efficacy experiments involving avian pest control materials: Design considerations imposed by the scientific method

Managers and researchers alike often incorrectly discuss efficacy of an avian pest control material. However, a material cannot be universally efficacious. Instead, efficacy can be established only for particular treatment forms of the control material where the treatment form is completely and uniquely specified by the product that is used to carry the material to the pest and the method of delivery of this product. The scientific method requires that experiments be conducted to evaluate the efficacy of treatment forms. This paper emphasizes that design is the appropriate vehicle through which a researcher attempts to ensure that an experiment will yield data pertinent to the hypothesis under investigation. The design process is discussed as it applies to field evaluation of avian pest control materials. Evaluation of efficacy of a treatment form of an avian pest control material and field measurements for efficacy are considered.
Passive Acoustic Tracking of Minke Whales

Abstract : This project developed model-based 3D passive acoustic tracking methods for minke whales. It was conducted in support of ONR Award N000140910489 in which T. Norris (Bio-Waves) conducted visual surveys at PMRF and S. Martin (SPAWAR) collected acoustic data on the PMRF bottom-mounted hydrophones. In this project, these data were analyzed to detect, characterize, and track minke whale calls. A minke boing detector and 3D model-based tracker was implemented. Acoustically derived positions were compared with SPA WAR position estimates (using the MM3 2D time-of-arrival tracking method). The MM3 2D tracker gave similar boing position estimates to the 3D model-based tracker. The localized boings were within the range for which direct paths exit and for which the constant-SSP TOA method (used by MM3 2D) is expected to give reasonable position estimates. The importance of using model-based tracking to get accurate position estimates increases with the range of the animal from the hydrophones, with hydrophone spacing, and with increasing complexity of sound speed profiles.
The Influence of Site Design and Resource Conditions on Outdoor Recreation Demand: A Mountain Biking Case Study

We investigated the influence of several choice variables on the demand for six mountain biking sites in the Research Triangle area, North Carolina. In combining on-site data collected from users a...
The challenges of automation in the automobile.

This commentary responds to the article by Peter Hancock, ‘Some Pitfalls in the Promises of Automated and Autonomous Vehicles’ (Hancock 2018). Hancock points out that the vehicle will need to funct...
If You Do Not Care About It, Sell It: Trading Location Privacy in Mobile Crowd Sensing

Mobile crowd sensing (MCS) is a technique where sensing tasks are outsourced to a crowd of mobile users. Since most of sensing tasks are location-dependent, workers are required to embed their locations into sensing reports, which incurs location privacy vulnerabilities. Realizing that workers perceive their location privacy differently, in this work we construct an auction-based trading market, facilitating location privacy trading between workers and the platform. Each worker can decide how much location privacy to disclose to the platform based on its own location privacy leakage budget $\xi$. The higher $\xi$ is, the less secrecy its reported location preserves. As a result, it receives higher payment from the platform as a compensation to its privacy loss. Besides, our mechanism enables the platform to select a suitable set of winning workers to achieve desirable service accuracy. For this purpose, a heuristic algorithm is devised, with polynomial-time complexity and bounded optimality gap. As formally proved in this manuscript, our proposed mechanism guarantees a series of nice properties, including $\xi$-privacy, $(\alpha,\beta)$accuracy, and budget feasibility.
Apocynin and Tempol ameliorate dietary sodium-induced declines in cutaneous microvascular function in salt-resistant humans

High-sodium diets have deleterious effects on vascular function, likely mediating, in part, the increased cardiovascular risk associated with a high sodium intake. Local infusion of apocynin and Te...
The Objectivity of Science

(1977). The Objectivity of Science. Bulletin of the Atomic Scientists: Vol. 33, No. 2, pp. 55-60.
Dermatologic Conundrum: A Cardiac Condition Masqueraded as a Dermatologic Distraction

A 38-year-old male presented to the emergency department (ED) complaining of extreme pain and a petechial rash on the left ankle for two weeks associated with generalized fatigue, intermittent fevers, and weight loss. He was discharged home from the ED on pain medications. He returned a few days later with a progressive rash that involved the entire left lower extremity to the level of the knee. He was diagnosed with herpes zoster (shingles) and was prescribed acyclovir and steroids. After several days, the patient presented for the third time to the ED. He developed a right lower extremity discomfort this time. The pain in bilateral lower extremities had become unbearable. His cardiac examination revealed a systolic murmur at the apex and a faint diastolic murmur at the left sternal border. Ultimately, he had an echocardiogram that demonstrated both a bicuspid aortic valve and large vegetation on the anterior leaflet of the mitral valve, and his blood culture grew Streptococcus mitis and Streptococcus oralis. The patient was subsequently diagnosed with subacute bacterial endocarditis thought to be sourced from his poor dentition. The diagnosis of infective endocarditis is often delayed due to its nonspecific clinical presentations. Our case displays an unusual skin manifestation of IE that may be present in the absence of other signs and symptoms of the disease.
Multi-task learning for natural language processing in the 2020s: where are we going?

Abstract Multi-task learning (MTL) significantly pre-dates the deep learning era, and it has seen a resurgence in the past few years as researchers have been applying MTL to deep learning solutions for natural language tasks. While steady MTL research has always been present, there is a growing interest driven by the impressive successes published in the related fields of transfer learning and pre-training, such as BERT, and the release of new challenge problems, such as GLUE and the NLP Decathlon (decaNLP). These efforts place more focus on how weights are shared across networks, evaluate the re-usability of network components and identify use cases where MTL can significantly outperform single-task solutions. This paper strives to provide a comprehensive survey of the numerous recent MTL contributions to the field of natural language processing and provide a forum to focus efforts on the hardest unsolved problems in the next decade. While novel models that improve performance on NLP benchmarks are continually produced, lasting MTL challenges remain unsolved which could hold the key to better language understanding, knowledge discovery and natural language interfaces.
Swipe Right: a Comparison of Accuracy of Plant Identification Apps for Toxic Plants.

Plant identification applications for use on smartphones have been increasing in availability, accuracy, and utilization. We aimed to perform an introductory study to determine if a plant identification application (ID app) used on a smartphone could identify toxic plants, and to compare apps to determine which is most reliable. We compared three popular iPhone plant ID apps, PictureThis (PT), PlantSnap (PS), and Pl@ntNet (PN), used to identify 17 commonly encountered toxic plants. Apps were used to photograph the entire plant, leaves, and flowers of ≥ 10 different plants for each species. Two toxicologists performed plant identification with confirmation of identification performed by a botanist, and inter-researcher agreement was confirmed. For each plant species, scores for accuracy of app identification of leaves, flowers, and whole plant were combined to create an overall composite score used to compare accuracy of each app (95% C.I.). PictureThis had the best performance with 10/17 (59% [36 to 78]) plant species identified 100% correctly, as opposed to 8/17 (47% [26 to 69]) for Pl@ntNet and 1/17 for PlantSnap (5.8% [1.1 to 27]). A plant identification app may be a useful tool to assist healthcare providers and the public in identifying toxic plants.
HB 544 and the Freedom of Religion

This essay comments on a proposed bill in New Hampshire that would prevent the teaching of "divisive concepts" in public schools (at least). The text of the bill is available here: https://legiscan.com/NH/text/HB544/id/2238380. This essay comments on the bill from the perspective of state constitutional law and the freedom of religion. It does so, in part, because the legal rights surrounding freedom of religion in the United States, and in the various states, appear to this scholar to be a domain where some available legal and discursive defenses of liberalism reside.
The role of hydropower reservoirs in deep decarbonization policy

Abstract This paper analyzes the role of hydropower reservoirs in the deep decarbonization of power systems. Extending previous work, this study models the impact of hydro reservoirs on optimal planning decisions. It further provides a more holistic assessment of the role and economic value of hydro reservoirs through the use of a detailed capacity expansion and dispatch model. Our model is parameterized based on the power system of New England, U.S. and the hydro-based system of Quebec, Canada. We find that expanding transmission access to hydro reservoirs reduces the need for fossil-fuel power plants that may otherwise be deployed to balance renewable intermittency. Our results show that hydro access can accelerate decarbonization by decreasing optimal gas plant capacity and generation. At levels of very deep decarbonization, reservoir hydro reduces the need for Carbon Capture and Storage. Our modeling shows how hydro reservoirs accomplish this by serving as both a short- and long-term energy storage resource. We further show that, by reducing the need for more expensive balancing technologies and by enabling a more efficient utilization of variable renewables, hydro access lowers the cost of decarbonization, and that this benefit grows non-linearly with the decarbonization target.
Minimizing water consumption for sugar and lignin recovery via the integration of acid and alkali pretreated biomass and their mixed filtrate without post-washing.

Abstract Excessive post-washing of pretreated biomass leads to huge water consumption and chemical loss. To address this issue, parallel HOAc and NaOH pretreatments of biomass followed by integration of their biomass and filtrate were investigated. Pretreatment effectiveness including morphology, crystallinity, and component recovery, were elucidated. Results showed that HOAc and NaOH in the mixed filtrate were neutralized to achieve a pH of around 4.80 prompting the alkali lignin precipitation. Lignin (46.01 and 48.38 g/kg-biomass for hemp and poplar, respectively) exhibiting comparable FTIR characteristics with the commercial alkali lignin was recovered. Compared to sodium acetate buffer as a control, integrating HOAc and NaOH pretreated biomass and their mixed filtrate for enzymatic hydrolysis boosted total sugar concentration (hemp: 42.90 vs. 38.27 g/L; poplar: 43.18 vs. 38.76 g/L) without compromising glucose yield (hemp: 70.86 vs. 70.69%; poplar: 66.48 vs. 69.48%) but improving xylose yield (hemp: 60.10 vs. 35.92%; poplar: 56.90 vs. 29.39%).
Exploring the Application of Interpretive Description in Chronic Illness: A Scoping Review.

BACKGROUND AND PURPOSE Chronic illness is a complex condition that affects over one billion people. To develop a deeper insight of the needs of this patient population, interpretive description uses disciplinary knowledge as the source of understanding. This methodology is a pragmatic approach to research without focusing on a strict methodological directive. The aims of this scoping review are twofold, (a) to describe the findings of studies that have used Thorne's interpretive description to research chronic illness and (b) to discuss the application of interpretive description in clinical research. Thereby, showing interpretive description as a valuable tool to advance nursing knowledge and patient care. METHODS The methodological framework for this review was based on the Johanna Briggs Institute guidelines for scoping reviews. RESULTS To develop an understanding of interpretive description, it is essential to examine the results of studies which have applied the methodology. Our scoping review showed that researchers utilizing interpretive description identified four common challenges experienced by individuals living with chronic illness: symptom management, education and knowledge, supportive care, and cultural disadvantages. By demonstrating how interpretive description is applied, it shows how it can be used to understand and interpret clinical phenomena to improve practice. IMPLICATION FOR PRACTICE This scoping review demonstrates how interpretive description was used to develop knowledge about chronic illness. The premise of interpretive description is that disciplinary knowledge offers a sufficient foundation to develop meaningful research to support health practices. By approaching research from a disciplinary perspective, new knowledge can be discovered to complex health problems.
Why ex post peer review encourages high-risk research while ex ante review discourages it.

Peer review is an integral component of contemporary science. While peer review focuses attention on promising and interesting science, it also encourages scientists to pursue some questions at the expense of others. Here, we use ideas from forecasting assessment to examine how two modes of peer review -- ex ante review of proposals for future work and ex post review of completed science -- motivate scientists to favor some questions instead of others. Our main result is that ex ante and ex post peer review push investigators toward distinct sets of scientific questions. This tension arises because ex post review allows an investigator to leverage her own scientific beliefs to generate results that others will find surprising, whereas ex ante review does not. Moreover, ex ante review will favor different research questions depending on whether reviewers rank proposals in anticipation of changes to their own personal beliefs, or to the beliefs of their peers. The tension between ex ante and ex post review puts investigators in a bind, because most researchers need to find projects that will survive both. By unpacking the tension between these two modes of review, we can understand how they shape the landscape of science and how changes to peer review might shift scientific activity in unforeseen directions.
A Glance of the Layered Transition Metal Oxide Cathodes in Sodium and Lithium-ion Batteries: Difference and Similarities.

The fast-growing demand of energy storage devices has prompted diverse battery techniques, while the state-of-the-art Li-ion batteries (LIBs) continue to flourish, Na-ion batteries (SIB) have been identified to be a promising alternative to share the burden with LIBs, particularly for large scale grid storage applications. Both LIBs and SIBs techniques work based on similar fundamental mechanisms, with a heavy focus on intercalation chemistry of layered transition metal (TM) oxides. However, the differences between Li-ion and Na-ion in terms of their size and Lewis acidity induce many different behaviors when crystallizing or diffusing in layered cathode materials. This minireview summarizes some typical cases where Li and Na-ion differ in layered cathode materials and discusses potential approaches to leverage their similarities and dissimilarities for future developments of high-performance Na-ion batteries.
Disentangling Administrative Searches

Everyone who has been screened at an international border, scanned by an airport metal detector, or drug tested for public employment has been subjected to an administrative search. Since September 11th, the government has increasingly invoked the administrative search exception to justify more checkpoints, unprecedented subway searches, and extensive wiretaps. As science and technology advance, the frequency and scope of administrative searches will only expand. Formulating the boundaries and requirements of administrative search doctrine is therefore a matter of great importance. Yet the rules governing administrative searches are notoriously unclear. This Article seeks to refocus attention on administrative searches and contends that much of the current mischief in administrative search law can be traced to the Supreme Court’s conflation of two distinct types of searches within one doctrinal exception – namely “dragnet searches” of every person, place, or thing in a given area or involved in a particular activity and “special subpopulation searches” of individuals deemed to have reduced expectations of privacy. Dragnets came first, and special subpopulation searches came later. As the category of administrative searches tried to accommodate both kinds of searches, it gradually lost the ability to impose meaningful limitations on either one. To bring clarity and sense to this area of the law, this Article proposes that we disentangle these two kinds of administrative searches.
Hewlett-Packard's self-assessment procedure for product stewardship

This paper provides an overview of the objectives, scope, content and results "lessons learned" from pilot testing of Hewlett-Packard's self-assessment procedure for product stewardship. The procedure has been designed to facilitate further integration of product stewardship into HP's mainstream businesses by enabling all HP business entity managers to: (1) clarify product stewardship's business significance to their entity specifically, and BP overall; and, (2) establish that their entity's actions taken and planned are adequate to meet the entity's and HP's emerging business needs in this area. The chief value is the increased insight and awareness that the entity general manager and their functional management team should gain from actively reviewing their situation, needs, status and actions with their division product steward. The procedure is being deployed at all of HP's worldwide divisions during 1996.
Structure of the rgRGs domain of p115RhoGEF

p115RhoGEF, a guanine nucleotide exchange factor for Rho GTPase, is also a GTPase activating protein (GAP) for G12 and G13 heterotrimeric Gα subunits. Near its N-terminus, p115RhoGEF contains a domain (rgRGS) with remote sequence identity to RGS (regulators of G protein signaling) domains. The rgRGS domain is necessary but not sufficient for the GAP activity of p115RhoGEF. The 1.9 A resolution crystal structure of the rgRGS domain shows structural similarity to RGS domains but possesses a C-terminal extension that folds into a layer of helices that pack against the hydrophobic core of the domain. Mutagenesis experiments show that rgRGS may form interactions with Gα13 that are analogous to those in complexes of RGS proteins with their Gα substrates.
A bridge to reality: Utilization of a clinical skills and simulation center in a large college of pharmacy

This article describes the implementation and assessment of simulation activities at a College of Pharmacy, including strategies to incorporate simulation for large class sizes without undergoing major curricular revision. The activities were developed to create a simulated environment for students to apply clinical skills and knowledge to enhance learning prior to advanced pharmacy practice experiences. Preliminary assessment suggests a positive impact of the activities on students’ confidence in their knowledge and skills. This report is intended to offer other Schools or Colleges of Pharmacy considerations for use of a clinical skills and simulation center.
Microdroplet temperature calibration via thermal dissociation of quenched DNA oligomers.

The development of microscale analytical techniques has created an increasing demand for reliable and accurate heating at the microscale. Here, we present a novel method for calibrating the temperature of microdroplets using quenched, fluorescently labeled DNA oligomers. Upon melting, the 3′ fluorophore of the reporter oligomer separates from the 5′ quencher of its reverse complement, creating a fluorescent signal recorded as a melting curve. The melting temperature for a given oligomer is determined with a conventional quantitative polymerase chain reaction (qPCR) instrument and used to calibrate the temperature within a microdroplet, with identical buffer concentrations, heated with an infrared laser. Since significant premelt fluorescence prevents the use of a conventional (single-term) sigmoid or logistic function to describe the melting curve, we present a three-term sigmoid model that provides a very good match to the asymmetric fluorescence melting curve with premelting. Using mixtures of three oligomers of different lengths, we fit multiple three-term sigmoids to obtain precise comparison of the microscale and macroscale fluorescence melting curves using “extrapolated two-state” melting temperatures.
Federal Family-Friendly Workplace Policies Barriers to Effective Implementation

Women's work experiences continue to be characterized by metaphors such as glass ceilings, glass walls, sticky floors, and trap doors (Guy, 1995) To what extent do the implementation of flexble wor...
Oxidation of Paraffins by Plant Tissues

Paraffins are found in almost every organism, plants (2), animals (13), and microorganisms (14). The most common biological source of paraffins appears to be the surface lipids of plants (2), the chain length of the most abundant paraffin being most often C,9 or C31. These natural paraffins can be readily catabolized by soil organisms (5) and to a limited extent by anlimals (6). The mechanism of paraffin oxidation was elucidated with bacteria (12) and with enzymes isolated from them (4,15,16). Young leaves of many plants readily synthesize paraffins from fatty acids (8). Experiments on the time course of incorporation of labeled substrates into paraffins of Brassica oleracea failed to show any turnover, possibly because the paraffins are ejected onto the surface of the leaves as soon as they are synthesized (7). Attempts to show catabolism by providing Co, paraffin to excised leaves, leaf tissue slices, or leaf homogenates failed. The extremely low solubility of these very long paraffins, and the resulting lack of uptake made it almost impossible to find out whether plants possess the capacity to oxidize their natural paraffins. In order to circumvent these problems a much smaller paraffin, hexadecane-l-14C, was used as substrate. This communication describes experimental results which show that plants do possess the ability to oxidize the terminal methyl carbon of this paraffin to a carboxyl group. Hexadecane-l-'4C (47.2 mc/mmole, Nuclear-Chicago) contained polar impurities and was therefore purified by column chromatography on activated SilicAR cc-4 100 to 200 mesh (Mallinckrodt Chemical Works. St. Louis, Missouri) with hexane as the solvent (9). The purified hexadecane-l-14C contained no radiochemical impurity as determined by thin-layer chromatography. A sample of this labeled paraffin (50 juc) was dissolved in 4 to 5 ml ethyl ether and 3 (rops of Tween-20 were added. The ether was evaporated with a stream of nitrogen, and the residue shaken with 10 ml of water to give a stable emulsion of the paraffin. Young leaves of broccoli, pea and tobacco, second from the apex and not fully expanded, were sliced (2 X 10 mm) with a razor blade. These slices when incubated with the purified hexadecane, produced radioactive lipids more polar than paraffin as shown in table I. Although Table I. Oxidation of Hexadecane-1-l4C by Leaf Slices of Broccoli, Pea, and Tobacco In experiment 1, 1 g of leaf slices was incubated with 2 X 106 cpm hexadecane-l-14C for 4 hr at 30° in 3 ml water. In experiment 2, 3 g of pea hypocotyl slices were incubated with 4 X 106 cpm hexadecane-l-14C for the periods indicated at 30° in 3 ml water. At the end of the incubation period, tissue slices were ground in a 2:1 mixture of chloroform and methanol, and the total lipids extracted as described before (9). Aliquots of the total lipids were chromatographed on silica gel G plates with hexane as the developing solvent in an unlined tank. Only paraffins migrated with the solvent front. The oxidation products such as fatty alcohols, acids and phospholipids remained at the origin. The radioactivity in this fraction is shown in the table.
Vesicles bearing MHC class II molecules mediate transfer of antigen from antigen-presenting cells to CD4+ T cells.

Previous studies have provided evidence that myelin basic protein (MBP)-specific rat T cells acquire antigen via transfer of preformed peptide / MHC class II complexes from splenic antigen-presenting cells (APC). The purpose of the present study was to determine how T cells acquire peptide / MHC class II complexes from APC in vitro. Our results show that a MHC class II+ T cell line, R1-trans, released MHC class II-bearing vesicles that directly stimulated MBP-specific CD4+ T cells. Vesicles expressing complexes of MHC class II and MBP were also specifically cytotoxic to MBP-specific T cells. Surviving T cells acquired MHC class II / antigen complexes from these vesicles by a mechanism that did not require protein synthesis but depended on specific TCR interactions with peptide/self MHC complexes. Furthermore, MBP / MHC class II-bearing vesicles enabled T cells to present MBP to other T cell responders. These studies provide evidence that APC release vesicles expressing preformed peptide / MHC class II complexes that interact with clonotypic TCR, allowing MHC class II acquisition by T cells. Vesicular transport of antigen / MHC class II complexes from professional APC to T cells may represent an important mechanism of communication among cells of the immune system.
Role of NO in inhibiting CO oxidation over alumina-supported rhodium

The inherent rate of the COO2 reaction over alumina-supported Rh is much higher than that of the CONO reaction. Rate measurements in CONOO2 mixtures have shown, however, that the presence of even small amounts of NO in the reactant stream prevents the occurrence of the CO O2 reaction until the extent of the CONO reaction becomes significant, resulting in the simultaneous onset of both the COO2 and CONO reactions near the lightoff temperature for the CONO reaction itself (i.e., in the absence of O2). This indicates that the overall kinetic behavior of RhAl2O3 in CONOO2 mixtures is dominated by the features characteristic of the CONO reaction rather than by those of the COO2 reaction. These kinetic interactions among the reactant species, including the NO inhibition effect on the CO oxidation rate, can be interpreted on the basis of a mechanism involving the blocking of the reactive sites by molecularly adsorbed NO. Similar experiments with a ptal2o3 catalyst have shown that its CO oxidation activity is much less affected by the presence of NO than is the CO oxidation rate over RhAl2O3.
The Role of the Federal Government in Promoting Health Through the Schools: Report from the Division of Adolescent and School Health, Centers for Disease Control

Statement of Lloyd J. Kolbe, PhD, Director, Division of Adolescent and School Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, before the Subcommittee on Oversight of Government Management, Committee on Governmental Affairs, U.S. Senate, November 14, 1991.
Discrimination of time intervals marked by brief acoustic pulses of various intensities and spectra

Experienced observers were asked to identify, in a four-level 2AFC situation, the longer of two unfilled time intervals, each of which was marked by a pair of 20-msec acoustic pulses. When all the markers were identical, high-level (186-dB SPL) bursts of coherently gated sinusoids or bursts of band-limited Gaussian noise, a change in the spectrum of the markers generally did not affect performance. On the other hand, for 1-kHz tone-burst markers, intensity decreases below 25 dB SL were accompanied by sizable deterioration of the discrimination performance, especially at short (25-msec) base intervals. Similarly large changes in performance were observed also when the two tonal markers of each interval were made very dissimilar from each other, either in frequency (frequency difference larger than 1 octave) or in intensity (level of the first marker at least 45 dB below the level of the second marker). Time-difference thresholds in these two latter cases were found to be nonmonotonically related to the base interval, the minima occurring between 40- and 80-msec onset separations.
INFLUENCE OF PARA-HYDROXYBENZOIC ACID ESTERS ON THE GROWTH AND TOXIN PRODUCTION OF Clostridium botulinum 10755A

The effect of the methyl and propyl esters of para-hydroxybenzoic acid (parabens) on growth and toxin formation by C. botulinum 10755A spores was studied. Pre-reduced anerobically sterilized media and strict anerobic techniques were employed. The addition of 200 ppm of propylparaben to a thiotone-yeast extract-glucose (TYG) growth medium inhibited germination and toxin production of C. botulinum 10755A for up to 120 hr at 37°C. Growth and toxin production were delayed when 100 ppm propylparaben was added to TYG. When 1200 ppm of methylparaben was added to TYG, germination and toxin production were inhibited, while 1000 ppm delayed growth and toxin production, and 400 ppm slightly delayed growth and toxin production.
Kraft lignin as fiber treatment for natural fiber‐reinforced composites

Pine kraft lignin was sedimented from an aqueous NaOH solution (pH 13) onto flax fibers by submerging flax fiber mats in the alkaline solution for 5 min. This treatment has been used to improve the interfacial interactions between the hydrophilic flax and a hydrophobic soy-oil-based liquid molding resin. The flax fiber mat weight increase as a function of the lignin content in the alkaline treatment solution was determined and visualized using electron microscopy. Lignin sedimentation was found to decrease the contact angle between the resin and the treated flax fibers. Tensile and flexural properties of the composite samples showed an increase in mechanical properties with increasing lignin sedimentation, with a positive deviation for low lignin sedimentation. These results are in line with previous published data with hemp fiber composites [Thielemans et al. (2002), J. Appl. Polym. Sci., 83, 323]. Improved properties are attributed to the improved wettability, while the low lignin content deviation is due to small lignin deposits protruding from the surface and thus improving mechanical interlocking. Features on the fracture surfaces, visualized by electron microscopy, are consistent with these findings. The soy-oil-based resin behaves similar to existing petroleum-based unsaturated polyester and vinylester resins and its use is not inherent to the success of the lignin treatment. POLYM. COMPOS., 26:695–705, 2005. © 2005 Society of Plastics Engineers
EPL mask fabrication

The next generation lithography, either electron or photon based, will be first introduced on critical levels for device manufacture. These levels have different requirements for difficulty of meeting image size uniformity, image placement, and patterning requirements on masks. Membrane masks are needed for electron projection lithography (EPL), and the fabrication of membrane masks generates new requirements such as the need for complementary mask pairs for stencil masks. In this paper, we discuss experiments for fabricating EPL masks for device levels.
Helmet-mounted display human factor engineering design issues: past, present, and future

An often overlooked area of helmet-mounted display (HMD) design is that of good human factors engineering. Systems which pass bench testing with flying colors can often find less enthusiastic acceptance during fielding when good human factors engineering principles are not adhered to throughout the design process. This paper addresses lessons learned on the fielding of the AH-64 Apache Integrated Helmet and Display Sight System (IHADSS) and the Aviator's Night Vision Imaging System (ANVIS). These lessons are used to develop guidance for future HMDs in such diverse areas as: user adjustments, anthropometry, fit and comfort, manpower and personnel requirements, and equipment compatibility.
Three Faces of Deference

Deference - the substitution by a decision maker of someone else's judgment for its own - is a pervasive tool of constitutional doctrine. But although it has been studied at more abstract levels of jurisprudence and at very specific doctrinal levels, it has received surprisingly little general attention in constitutional scholarship. This Article aims to fill that gap. This Article makes three primary contributions to the literature. First, it provides a careful examination of deference as a doctrinal tool in constitutional law, and offers a taxonomy of deference. In particular, it suggests that deference can best be understood as relying on two separate but overlapping grounds: deference on the basis of the legal authority of the deferee, and deference on the basis of the deferee's epistemic, or knowledge-based, authority. Importantly, this Article suggests that deference cannot be examined from the standpoint of the deferring institution - usually, the courts - alone. Rather, we must also consider the obligations of deferees, which should invoke deference only for those decisions reached in the full and fair exercise of their legal or epistemic authority. Second, the Article demonstrates the practical benefits of this richer understanding of deference by applying it to a recent case in which the Supreme Court confronted competing claims of deference: Rumsfeld v. Forum for Academic and Institutional Rights ("FAIR"), in which the Supreme Court rejected a challenge to the Solomon Amendment, which requires law schools to provide access to campus for military recruiters. In FAIR, the Court faced claims of deference from Congress, acting pursuant to its military powers, and from the law schools, which invoked deference both as expressive associations and as universities. The Court's treatment of these competing claims to deference was unsatisfactory. The Court gave too much deference to Congress, and too little to the law schools. In particular, it failed to accord them the deference they deserved as universities, which serve as vital "First Amendment institutions" in the universe of public discourse. The Court's failure to soundly address these competing claims of deference bespeaks a larger failure to theorize the nature of deference and the occasions on which courts should defer. Thus underequipped, the Court was left at sea when confronting multiple institutions competing for deference in the same case. At the same time, the law schools themselves may have fallen short in meeting their own obligations as deferees. Finally, the Article shows that its examination of deference, and of universities as First Amendment institutions, lies at the intersection of two developing areas of constitutional scholarship: the study of constitutional decision rules, and the study of institutionally oriented approaches to the First Amendment. It argues that these two emerging fields are linked by the concept of deference, and might learn a good deal from each other.
Hydrocarbon Accumulation in Pennsylvanian-Age Tensleep Sandstone: Trapper Creek Deposit, Wyoming: ABSTRACT

Preliminary investigations indicate a potential hydrocarbon accumulation in the Trapper Creek, Wyoming, deposit of more than 2.13 million tons of mineralized material with a yield of 0.92 bbl per ton of 5.2° API oil for an approximate resource of 1.96 million bbl of recoverable petroleum. Remote sensing data suggest that the accumulation is in part controlled by two major and four minor lineaments which traverse the area. Stratigraphic and lithologic criteria can be used to infer a "Minnelusa-type" model of occurrence. Ancillary stream sediment and outcrop geochemistry yield locally anomalous, but uneconomic concentrations of magnesium, calcium, titanium, manganese, silver, copper, molybdenum, vanadium, potassium, and silicon, which may have significance in the ident fication of similar hydrocarbon accumulations along the west flank of the Bighorn Mountains. End_of_Article - Last_Page 1330------------
The Culture of Methamphetamine: Reframing Gay Men's Methamphetamine Use

Most often, methamphetamine researchers examine the biological and psychological outcomes of chronic methamphetamine use and problems leading toward relapse. Consequently, the current intervention models tend to sidestep the salience of socio-cultural environments that influence methamphetamine use. In line with the person-in-environment framework of social work, we submit that understanding these facets can illuminate the dynamic processes that initiate and support methamphetamine use and the subsequent risky sexual behaviors among gay and bisexual men. To that end, this article is a review and synthesis of existing literature on methamphetamine use in the men who have sex with men community. We also provide some recommendations for practitioners.
Synthesis and fate of o-carboxybenzophenones in the biosynthesis of aflatoxin.

o-Carboxybenzophenones have long been postulated to be intermediates in the oxidative rearrangement of anthraquinone natural products to xanthones in vivo. Many of these Baeyer−Villiger-like cleavages are believed to be carried out by cytochrome P450 enzymes. In the biosynthesis of the fungal carcinogen, aflatoxin, six cytochromes P450 are encoded by the biosynthetic gene cluster. One of these, AflN, is known to be involved in the conversion of the anthraquinone versicolorin A (3) to the xanthone demethylsterigmatocystin (5) en route to the mycotoxin. An aryl deoxygenation, however, also takes place in this overall transformation and is proposed to be due to the requirement that an NADPH-dependent oxidoreductase, AflM, be active for this process to take place. What is known about other fungal anthraquinone → xanthone conversions is reviewed, notably, the role of the o-carboxybenzophenone sulochrin (25) in geodin (26) biosynthesis. On the basis of mutagenesis experiments in the aflatoxin pathway and these ...