cssi/SciSciGPT-SciSciNet huggingface dataset:
Myopic defocus in the evening is more effective at inhibiting eye growth than defocus in the morning: Effects on rhythms in axial length and choroid thickness in chicks

Animal models have shown that myopic defocus is a potent inhibitor of ocular growth: brief (1-2 h) daily periods of defocus are sufficient to counter the effects of much longer periods of hyperopic defocus, or emmetropic vision. While the variables of duration and frequency have been well-documented with regard to effect, we ask whether the efficacy of the exposures might also depend on the time of day that they are given. We also ask whether there are differential effects on the rhythms in axial length or choroidal thickness. 2-week-old chickens were divided into 2 groups: (1) "2-hr lens-wear". Chicks wore monocular +10D lenses for 2 h per day for 5 days at one of 3 times of day: 5:30 a.m. (n = 11), 12 p.m. (n = 8) or 7:30 p.m. (n = 11). (2) "2-hr minus lens-removal". Chicks wore monocular -10D lenses continually for 7 days, except for a 2-hr period when lenses were removed; the removal occurred at one of 2 times: 5:30 a.m. (n = 8) or 7:30 p.m. (n = 8). Both paradigms exposed eyes to brief myopic defocus that differed in its magnitude, and in the visual experience for the rest of the day. High frequency A-scan ultrasonography was done at the start of the experiment; on the last day, it was done at 6-hr intervals, starting at noon, over 24-hr, to assess rhythm parameters. Refractive errors were measured using a Hartinger's refractometer at the end. In both paradigms, myopic defocus in the evening was significantly more effective at inhibiting eye growth than in the morning ("2-hr lens-wear": X-C: -149 vs -83 μm/5d; "2-hr lens-removal": X-C: 91 vs 245 μm/7d; post-hoc Bonferroni test, p < 0.01 for both). Data for "noon" was similar to that of "evening". In general, the refractive errors were consistent with the eye growth. In both paradigms, a 2-way ANOVA showed that "time of day" accounted for the differences between the morning versus evening groups ("2-hr lens-wear": p = 0.0161; "2-hr lens-removal": p = 0.038). In the "plus-lens" morning exposure, the rhythm in axial length could not be fit to a sinusoid. In both paradigms, the rhythm in axial length for the evening group was phase-advanced relative to noon or morning ("2-hr lens-wear": evening vs noon; 1:24 p.m. vs 6:42 p.m.; "2-hr lens-removal": evening vs morning: 12:15 p.m. vs 6:18 p.m.; p < 0.05 for both). Finally, the amplitude of the rhythm as assessed by the "day vs night" maximum and minimum respectively, was larger in the "evening" than in the "morning" group ("2-hr lens-wear": 88 vs 38 μm; "2-hr lens-removal": 104 vs 48 μm; p < 0.05 for both). For the choroidal rhythm, there was no effect on phase, however, the amplitude was larger in most, but not all, experimental groups. These findings have potential translational applications to myopia prevention in schoolchildren, who are exposed to extended periods of hyperopic defocus during reading sessions, due to the nearness of the page. We propose that bouts of such near-work might best be scheduled later in the day, along with frequent breaks for distance vision.
Iterative optimization of xylose catabolism in Saccharomyces cerevisiae using combinatorial expression tuning

A common challenge in metabolic engineering is rapidly identifying rate-controlling enzymes in heterologous pathways for subsequent production improvement. We demonstrate a workflow to address this challenge and apply it to improving xylose utilization in Saccharomyces cerevisiae. For eight reactions required for conversion of xylose to ethanol, we screened enzymes for functional expression in S. cerevisiae, followed by a combinatorial expression analysis to achieve pathway flux balancing and identification of limiting enzymatic activities. In the next round of strain engineering, we increased the copy number of these limiting enzymes and again tested the eight-enzyme combinatorial expression library in this new background. This workflow yielded a strain that has a ∼70% increase in biomass yield and ∼240% increase in xylose utilization. Finally, we chromosomally integrated the expression library. This library enriched for strains with multiple integrations of the pathway, which likely were the result of tandem integrations mediated by promoter homology. Biotechnol. Bioeng. 2017;114: 1301-1309. © 2017 Wiley Periodicals, Inc.
Genie: Input Retargeting on the Web through Command Reverse Engineering

Most web applications are designed as one-size-fits-all, despite considerable variation in people's expertise, physical abilities, and other factors that impact interaction. For example, some web applications require the use of a mouse, precluding use by many people with severe motor disabilities. Other applications require laborious manual input that a skilled developer could automate if the application were scriptable. This paper presents Genie, a system that automatically reverse engineers an abstract model of the underlying commands in a web application, then enables interaction with that functionality through alternative interfaces and other input modalities (e.g., speech, keyboard, or command line input). Genie comprises an abstract model of command properties, behaviors, and dependencies as well as algorithms that reverse engineer this model from an existing web application through static and dynamic program analysis. We evaluate Genie by developing several interfaces that automatically add support for speech, keyboard, and command line input to arbitrary web applications.
Chemoselective ligation reaction of N-acetylglucosamine (NAG) with hydrazide functional probes to determine galactosyltransferase activity by MALDI mass spectrometry.

Quantification of β-1,4-galactosyltransferase (β-1,4-GT) activity is of considerable significance in the diagnosis of various cancers including lung and ovarian cancer. We report here the use of synthetic β-N-acetylglucosamine (NAG) ligands that contain hydrazide functional groups to determine galactosyltransferase activity by mass spectrometry. With hydrazide-linked β-D-NAG as the acceptor, the activity of β-1,4-GT is quantified by matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF) mass spectrometry (MS) with high efficiency. Using the disulfide moiety in a 3,3′-dithiodipropionic acid dihydrazide (DTP)-linked β-D-NAG probe, Au nanoparticles (AuNPs) are employed for enriching DTP-linked β-D-NAG after enzymatic reaction, and the ligand-bound AuNPs are subsequently deposited on a MALDI plate for analysis. In addition, we have demonstrated that a perfluorocarbon (PF) labeled β-NAG-ligand can be useful for surface-based enzymatic reaction with a perfluorooctadecanethiol (PFDT)-covered gold surface. Using the ratiometric method, the conversion rate of β-1,4-GT is determined to be 0.83 ± 0.03, which shows a high level of activity. This is the first work that uses hydrazide-linked β-D-NAG for activity analysis, providing a new surface-based MS approach to determine enzyme activity in a potentially high-throughput manner.
The influence of public transportation on housing values

ABSTRACTTransit-oriented development (TOD) is becoming an increasingly common development strategy with potential consequences on property values. This study explores the potential relationship between the proximity to public transportation and housing values. The objective is achieved by performing a hedonic regression using the 2013 American Housing Survey (AHS) sample, which includes 25 metro areas. In 2013, the AHS added a topical supplement addressing public transportation issues which makes understanding public transportation impacts on housing values more feasible. In this study, being located within half a mile of a public transportation stop was a significant factor in explaining housing values for 6 out of 25 metro areas. This research is important to real estate practitioners operating within TODs as proximity to public transportation may significantly influence property values.
Evolution of Simplified Frozen Elephant Trunk Repair for Acute DeBakey Type I Dissection: Midterm Outcomes.

Background A modified technique for frozen elephant trunk (FET) repair of acute DeBakey type I dissection has evolved. Procedural modifications are described and midterm outcomes evaluated. Methods From 2009 to 2016, 72 patients with DeBakey type I dissection underwent emergency simplified FET. Mean age was 59 ± 15 years. Presentation included malperfusion (n = 22, 31%), rupture (n = 12, 16%), and aortic insufficiency (n = 42, 58%). Concomitant procedures included valve replacement (n = 9), root replacement (n = 11; valve sparing n = 6), cusp repair (n = 11), and valve resuspension (n = 21). The first 39 were treated by modifying an early generation stent graft. The next 16 received newer modified stent grafts, and the latest 17 underwent branched single anastomosis technique with left subclavian stent grafting. Results Operative mortality was 4.2% (n = 3 of 72). Two presented comatose without recovering, the other died from coagulopathy complications. Morbidity included stroke (n = 3, 4.2%), spinal injury (n = 3, 4.2%; 1 permanent), tracheostomy (n = 7, 9.7%), and renal failure (n = 2, 2.8%). Median follow-up was 28 ± 25 months. Survival was 92% at 6 months, 92% at 1 year, 89% at 3 years, and 80% at 5 years. Among 69 survivors, follow-up imaging was available in 63 (91%). Of these, 58 (92%) patients thrombosed the treated false lumen, with shrinkage in 37(54%) patients from 42 ± 8 mm to 37 ± 7 mm. Ten patients underwent 14 late reinterventions for growth and incomplete thrombosis (7 endo extension, 4 left subclavian embolization, 1 bypass, 2 false lumen embolization). Freedom from reintervention was 93% at 6 months, 87% at 1 year, 77% at 3 years, and 72% at 5 years. Conclusions Simplified FET for treating acute DeBakey type I dissection has evolved and remained safe. It promotes aortic remodeling, and simplifies management of chronic aortic complications.
Early Placental Development

For many years, it was thought that the understanding of placental pathology required only a limited knowledge of implantation and early placental development, as disturbances of these early steps of placentation seemed to cause abortion, rather than affecting placental structure and function. Increasing experience with assisted reproductive technology (ART), as well as clinicopathologic correlation of placental pathology with fetal well-being, however, has taught us that improper conditions during implantation can handicap early development and result in inappropriate functioning of the fetoplacental unit and impaired outcome. For this reason, basic understanding of early placental development has become increasingly important.
Definition, Epidemiology, Pathophysiology, Clinical Classification, and Differential Diagnosis of Diarrhea

Diarrhea continues to be a challenge despite developments in science and remains a considerable source of morbidity and mortality. A wide variety of differential diagnoses need to be considered when evaluating patients with diarrhea. Diarrhea can be classified based on the duration into acute, persistent, and chronic diarrhea and this classification is important for diagnostic and treatment considerations. The epidemiological settings where diarrhea is seen help the clinician to narrow down the differential causes of diarrhea and to investigate appropriately. Acute diarrhea can happen in the setting of the community or it can be hospital acquired or acquired during travel. The etiologies and the diagnostic algorithms are different for each of these settings. The pathophysiolgy of diarrhea can be classified based on the mechanism into secretory, osmotic, inflammatory, iatrogenic/drug related, and functional/motility-related diarrhea. The differential diagnosis and the clinical classification depend on the basic pathophysiology with which diarrhea presents and can be inflammatory, watery encompassing osmotic and secretory, and fatty diarrhea. Gaining a better understanding of the pathophysiology of diarrhea will help us to initiate better preventive and treatment measures to improve the quality of life of these patients.
The Comparative Approach to Counterterrorism

Community policing has become a common theme when discussing how a democratic society maintains law and order without jeopardizing the freedoms and rights of its citizens.1 Ferreira (1996). The definition of community policing varies among scholars and researchers, and an agreement of universal definition has yet to be established. Depending on the definition being utilized, confusion and difficulty may occur when attempting to determine whether or not community policing is actually being implemented within a police department.2 Maguire and Mastrofski (2000). However, the broad concept of community policing, which typically indicates problem solving and community involvement as key components for effective policing, seems to remain somewhat consistent among the majority of definitions.
Applied Behavior Analysis and the Solution of Environmental Problems

In 1970, Wohlwill described the emerging field of environmental psychology and suggested that its emergence was due partly to a general concern with the deteriorating quality of our physical environment. A good deal of research and writing has appeared since Wohlwill’s paper, and as the titles of the chapters in this and the previous volume of the Human Behavior and Environment series attest, the interests of persons in the discipline are quite varied. Surprisingly, only a few of the titles suggest concern with the quality of the physical environment itself.
Role of interferons in demyelinating diseases

IFNβ-1b reduces the frequency of major multiple sclerosis attacks by 50 percent. Serial MRI scanning over the course of the clinical trial that led to approval of the agent revealed a significant lessening both in disease activity and in accumulating burden of disease in IFNβ-1b-treated patients compared to placebo-treated controls.
Negative Differential Resistance Devices and Circuits

This chapter presents a broad overview of negative differential resistance (NDR) devices and their operation, including intraband and interband tunneling topologies. The materials science issues and tradeoffs considered for their synthesis as well as how each impacts overall NDR performance are also discussed. It also explores circuit opportunities for digital and radio frequency towards compact low-power memory and logic and energy-efficient mixed-signal circuits. Further, extreme challenges for ultra-scaled complementary metal–oxide semiconductor (CMOS), coupled with advances of NDR devices compatible with Si CMOS processing, are bringing NDR junctions back to the forefront and guiding the path toward steep subthreshold transistors.
Cardiac and Cerebrovascular Response to Exercise in the Setting of Mechanical Circulatory Support among Individuals with Advanced Heart Failure

Purpose To characterize cardiovascular and cerebrovascular responses to exercise among individuals with continuous-flow left ventricular assist devices (CF-LVAD). Methods 9 CF-LVAD subjects, 11 patients with advanced heart failure with reduced ejection fraction (HFrEF, all New York Heart Association IIIB-IV with left ventricular ejection fraction Results Demographics are reported in Table 1. As demonstrated in Figure 1, workload and VO2 were similar between HFrEF and CF-LVAD groups, and significantly less than levels observed among HCs. Similarly, the increase in MAP and Qc throughout exercise was blunted among HFrEF and CF-LVAD groups in comparison to HCs. MCAV increased throughout exercise among HCs, but was relatively unchanged among HFrEF and CF-LVAD groups. Conclusion Despite restoration of resting Qc, CF-LVAD implantation is associated with a blunted cardiovascular and cerebrovascular response to exercise compared to healthy individuals, with exertional hemodynamics that are similar to individuals with advanced HFrEF.
Imposición efectiva a las empresas en Ecuador

This document aims to estimate the effective tax rate for corporate income tax in Ecuador, broken down by company size and economic sector. For this purpose, the annual returns for 2006, 2011 and 2016 filed by companies with the Internal Revenue Service are used. In addition, static simulations are performed to determine the modification in the effective tax rate if the tax incentives used by the firms do not exist and thus quantify the possible tax gains for the Treasury if the effective tax rates for companies are increased by eliminating tax incentives. The results show that large firms cover most of the incentives, that withdrawing tax benefits would generate additional revenue of more than 1% of GDP, and that there is no relationship between productivity and incentives.
Young African American women’s participation in an m-Health study in cardiovascular risk reduction: Feasibility, benefits, and barriers:

Background:Young black women have an increased risk of cardiovascular disease, and thus identifying innovative prevention strategies is essential. A potential preventive strategy is mobile health; ...
Solutions and Mixtures

We have discussed the flow and transport properties of homogeneous fluids consisting of a single chemical species, allowing for spatial density variations. In the remainder of this book, we turn out attention to inhomogeneous fluids consisting of two or more chemical species, including the effect of a chemical reaction. Preliminary concepts and the notion of diffusion are introduced in this chapter and then discussed further and elaborated in subsequent chapters.
Physician workforce in the United States of America: forecasting nationwide shortages.

Physicians play a critical role in healthcare delivery. With an aging US population, population growth, and a greater insured population following the Affordable Care Act (ACA), healthcare demand is growing at an unprecedented pace. This study is to examine current and future physician job surplus/shortage trends across the United States of America from 2017 to 2030. Using projected changes in population size and age, the authors developed demand and supply models to forecast the physician shortage (difference between demand and supply) in each of the 50 states. Letter grades were then assigned based on projected physician shortage ratios (physician shortage per 100 000 people) to evaluate physician shortages and describe the changing physician workforce in each state. On the basis of current trends, the number of states receiving a grade of “D” or “F” for their physician shortage ratio will increase from 4 in 2017 to 23 by 2030, with a total national deficit of 139 160 physician jobs. By 2030, the West is forecasted to have the greatest physician shortage ratio (69 physician jobs per 100 000 people), while the Northeast will have a surplus of 50 jobs per 100 000 people. There will be physician workforce shortages throughout the country in 2030. Outcomes of this study provide a foundation to discuss effective and efficient ways to curb the worsening shortage over the coming decades and meet current and future population demands. Increased efforts to understand shortage dynamics are warranted.
Project-Level Sustainable Asphalt Roadway Treatment Selection Framework Featuring a Flowchart and Analytic Network Process

AbstractSustainable development is one of the most widely studied contemporary issues in the transportation sector. However, few of the existing project-level, sustainability-oriented decision tool...
The tripartite model of relational efficacy beliefs in sport: a scoping review

This scoping review is focused on sport research activity stemming from Lent and Lopez’s (2002), tripartite relational efficacy model. The purpose was to (1) summarize the research findings with re...
Acculturation Experiences of Syrian Muslim Refugee Women in the United States: Intersectionality of Nationality, Religion, Gender, and Refugee Status:

Honoring the voices needing to be heard, the research investigated the lived experiences of six Syrian Muslim refugee women who resettled in the United States after the 2011 Syrian War. Data analys...
Demonstration of a Three-Dimensionally Structured Betavoltaic

In this work, we present a demonstration of a high-aspect ratio, three-dimensionally structured betavoltaic device. High-aspect ratio silicon PIN diodes were used as the semiconductor absorber and 147PmCl3 was used as the beta emitter. Three devices were fabricated with 147Pm activities of 2.4 mCi, 7.4 mCi, and 29.5 mCi. The device with the highest activity produced an initial power output of 200 nW and was monitored over a period of 8 months to observe the current–voltage behavior over time, during which time the output current decreased in accordance with the radioactive half-life of 147Pm. Small deviations in the output current of a few percent during the long-term measurement were found to be attributable to the humidity in the room where the experiment was done. The output current generated from the devices was 68–77% of the theoretical maximum, indicating significant infiltration of the radioisotope into the ridged structures.
DXA2: An Automated Program for Extraction of Dual-Energy X-Ray Absorptiometry Data.

Abstract Introduction/Background: Since the 1970s imaging devices have been rapidly advancing to provide researchers, clinicians, radiologists, and practitioners greater capabilities to image bone. Today, dual-energy X-ray absorptiometry (DXA) has emerged as the gold standard for the assessment of bone and body composition. Despite recent improvements in DXA image quality and reduced radiation dosages and scan times, the data extraction process has yet to be streamlined. The objective of this study was to design an application to allow DXA users to quickly and accurately transfer DXA report data directly into a user-friendly format. Methodology: Initial development of the DXA Data Xtraction Assistant (DXA2) included processing 485 DXA reports from a previous study. Using Python script, numeric data from these DXA reports were converted to .csv files and then merged into one file, effectively compiling and organizing all table data from each report, by participant and visit number. A graphical user interface was then developed and beta tested using multiple DXA manufacturers, models, and software versions. To compare the effectiveness of the DXA2 to the current standard of manual extraction, all 485 reports were manually transcribed into Microsoft Excel. The time required per report and the error rates were compared. Results: Manual transcription, by an experienced researcher, took over 10 h with an error rate of 0.6% and average error magnitude of 51%. Data extraction from DXA2 took less than 25 min to retrospectively reformat all DXA reports for the DXA2 and transcribe all 485 reports with 100% accuracy. Conclusion: The DXA2 application automates DXA report data extraction and aggregation for clinical, research, and applied settings and drastically reduces manual data entry time and eliminates transcription errors.
Modern Tort Law: Preventing Harms, Not Recognizing Wrongs

Part I of my review of John Goldberg and Benjamin Zipursky’s (GZ), Recognizing Wrongs (Harv. U. Press 2020) reframes the book as, first and foremost, a sustained critique of the law-and-economics, deterrence-focused view of tort law, rather than (as GZ set forth) the affirmative case for the “wrongs and redress” account of tort law. “Cheapest cost avoider” tort theory (as my chosen stand-in for instrumentalist, deterrence-based theories) plays the role of an antagonist, against which GZ construct their theory of wrongs and redress. Part II inverts the role of “cheapest cost avoider” as the protagonist of some of the most significant developments in contemporary tort law, focusing on its central role in the rise of strict products liability in tort and especially its extension to cover bystanders. Part III argues that law-and-economics deterrence-based theory holds the most promise for judges facing two primary challenges of modern torts: (1) containing modern risks at the cutting edge of the regulatory state; and (2) addressing widespread harms.
Abstract MP15: Promoting Lifestyle Change Via Real-time Feedback: Short-term Weight Loss Outcomes In The Smarter Trial

Background: Obesity is a major risk factor for CVD. Standard behavioral treatment (SBT) typically requires face-to-face sessions, is expensive, has limited evidence for sustained weight loss, and c...
Correlation of LINE-1 Hypomethylation With Size and Pathologic Extent of Dysplasia in Colorectal Tubular Adenomas.

INTRODUCTION Conventional adenomas (tubular adenoma [TA] or tubulovillous adenoma) and sessile serrated lesions (SSLs) are neoplastic precancerous lesions frequently detected in patients undergoing average risk screening colonoscopy and polyp surveillance. Metachronous risk stratification of adenomas is currently limited to histologic features and size of polyps. We report long interspersed nucleotide element-1 (LINE-1) methylation levels in SSL in comparison to TA and the impact of TA size and presence of high-grade dysplasia (HGD) on LINE-1 methylation. METHODS LINE-1 methylation was assessed by pyrosequencing of bisulfite-converted DNA. We compared LINE-1 methylation between TA and SSL, among varying sizes of TA, and between TA with HGD and low-grade dysplasia (LGD). RESULTS LINE-1 methylation declined with increasing polyp size in TA when comparing those <5 mm (72.31 ± 6.11), 5 to <10 mm (67.50 ± 7.00), and ≥10 mm (66.75 ± 11.89). There were lower LINE-1 methylation levels in TA with LGD (n = 119) compared with SSLs (n = 29) (69.11 ± 8.62 vs 81.41 ± 2.43, P < 0.001). TA containing HGD (n = 26) had lower LINE-1 methylation levels than those with LGD (n = 119) (59.86 ± 7.93 vs 69.11 ± 8.62, P < 0.001). DISCUSSION HGD and increasing size of TA/tubulovillous adenoma were associated with lower LINE-1 methylation. This supports a hypothesis that LINE-1 hypomethylation in TAs indicates advancement along the CRC tumorigenesis pathway. Lower LINE-1 methylation and greater variance of global DNA methylation was seen in TA compared with SSL. LINE-1 methylation in adenomas correlates with polyp size and degree of dysplasia and deserves further study as a predictor of metachronous colorectal cancer risk.
Induction of mammalian somatic cell hybridization by polyethylene glycol.

Publisher Summary This chapter discusses the induction of mammalian somatic cell hybridization by polyethylene glycol (PEG). The hybridization of somatic cells is a technique for the study of the organization and regulation of the mammalian genome. PEG induces mammalian cell hybridization and procedures have been developed for treating cells with PEG that are simple, rapid, and effective. The chapter outlines experiments to optimize the conditions of PEG-induced hybridization of cells attached in monolayers. Among the parameters considered were: (1) PEG molecular weight, (2) PEG concentration, (3) cell density, (4) pH, (5) length of exposure to PEG, (6) temperature, (7) volume of residual medium at the time of PEG addition, and (8) the method of removing the PEG. The experience with PEG-induced hybridization of cells in suspension is less extensive than with cells in monolayer; however a simple procedure giving consistent success with certain cell combinations has been developed. Although only a few variables have been examined for hybridization in suspension, it seems apparent that the principles established with monolayer fusions cannot be extrapolated to suspension fusions without some modification.
The regulation of fatty acid biosynthesis in human skin fibroblasts.

Fatty acid biosynthesis has been studied using primary cultures of human skin fibroblasts. Acetyl coenzyme A carboxylase activity of cells incubated in medium containing 15% fetal calf serum was 0.17 ± 0.01 nmole of malonyl coenzyme A formed per mg of protein per min whereas in cells incubated for 2 to 3 days in a medium with 15% lipid-deficient fetal calf serum acetyl-CoA carboxylase activity increased to a level of 0.29 ± 0.02 nmole of malonyl-CoA formed per mg of protein per min. Equivalence point determinations using an antibody against acetyl-CoA carboxylase indicate that the increase in enzyme activity results from increased enzyme content in the cells rather than from activation of preformed enzyme. The effect of lipid-deficient medium on acetyl-CoA carboxylase activity was reversed by the addition of normal fetal calf serum or by the addition of any of a number of different albumin-bound free fatty acids to the lipid-deficient medium. When cells originally incubated in medium containing normal fetal calf serum were switched to medium containing lipid-deficient fetal calf serum, an 8-fold increase in the rate of acetate incorporation into lipid was observed in the first 7 hours, whereas cells switched from lipid-deficient to normal serum-containing medium or medium supplemented with free fatty acids showed an almost immediate decrease in the rate of acetate incorporation. The changes in acetate incorporation occurred before any change in enzyme activity was seen, indicating that two types of control are exerted on fatty acid biosynthesis in these cells.
T2r + bacteriophage-induced enzymes. II. The subunit structure of deoxycytidylate deaminase.

Abstract The molecular weight of the T2r+ bacteriophage-induced deoxycytidylate deaminase was determined by sedimentation equilibrium to be 124,000 ± 1,800. Sedimentation of the enzyme in 6 m guanidine hydrochloride containing 0.1 m 2-mercaptoethanol yielded a homogeneous species with a molecular weight of 20,200 ± 100. Additional evidence that the enzyme is composed of six subunits, possibly identical, was obtained from sodium dodecyl sulfate-polyacrylamide gel electrophoresis studies before and after dimethyl suberimidate treatment and also by Sephadex G-200 chromatography. The molecular weight of the deaminase obtained by the latter procedure varied directly with the protein concentration; the lowest molecular weight approximated that of the monomer and the highest that of the hexamer. Intermediate values were considered weight average quantities resulting from the rapid equilibrium of monomer and hexamer. When deoxycytidine 5'-triphosphate was included in the elution buffers, the concentration dependence of molecular weight was eliminated and only the hexamer was evident. Most of the data suggest that the hexamer is the active form of deoxycytidylate deaminase, but that conformation is also important as evidenced by the finding that 0.5 m guanidine hydrochloride can reduce the enzyme activity by 50% with little apparent change in the s20,w. Guanidine hydrochloride at concentrations of 1 m, however, effects an almost complete loss in activity accompanied by disaggregation of the enzyme protein to a form with an s20,w of 3.0. Studies on the rate and extent of deaminase reactivation following denaturation by 6 m guanidine hydrochloride reveal that the renaturation process is a complex function of many parameters.
On Fixed Order Controllers for Delay Systems: Discrete Time Case

In this short paper we present-our preliminary results on the problem of finding fixed order stabilizing controllers for SISO discrete time finite dimensional plants. We assume that the controller has a computational time delay which increases with its dimension. This time delay is appended to the plant, and a fixed order stabilizing controller is investigated for the modified plant. We obtain necessary and sufficient conditions on the structure of fixed order controllers stabilizing a given plant with a time delay depending on the order of the controller.
Observation of high current effects in high energy linear accelerators

The acceleration and transport of electron beams with high currents and low emittances are subjects studied very carefully for many operating accelerators and most future accelerators. For a example, several Free Electron Lasers (FEL) and the Stanford Linear Collider (SLC) presently operate with high energy intense beams. The next generation of synchrotron light sources and future linear colliders require a much higher degree of component precision and beam control. In this note the basic concepts governing the effects of high currents in accelerators are explored, including observations of high currents in present accelerators. The effects of longitudinal wakefields on acceleration and energy spreads are studied first. Then, the transverse equations of motion are developed including the technique of BNS damping to control wakefield growth. These wakefield effects are investigated to characterize their influence on the control and observation of beam oscillations. Finally, the reduction of transverse wakefield effects is important for maintaining the emittance of intense beams. 49 refs., 48 figs.
Nasotracheal Intubation in Epiglottitis

Significant numbers of patients with epiglottitis have been treated using nasotracheal intubation. Evidence is accumulating that this procedure is safe, effective and reliable when used in this disease. Nasotracheal intubation should be considered a suitable alternative to tracheostomy in epiglottitis.
Radiofrequency field surveys in hospitals

We are undertaking a survey of Philadelphia-area hospitals for levels of radiofrequency (RF) fields in the frequency range 0.1-1000 MHz, to obtain background information related to the possible interference of radiofrequency fields with medical equipment. To date, three hospitals have been surveyed: two large center city hospitals, and a regional county hospital. Measurements were performed at 6-12 sites in each hospitals, selected to include areas in which high RF levels might be expected to exist, and at other representative sites in the hospitals. The average levels of radiofrequency signals in each of these hospitals were quite low (median value about 0.03 V/m); however sites could be identified with levels of RF fields exceeding 1-2 V/m. The maximum field strength was measured in the top floor of one hospital, near a window overlooking a paging antenna mounted on the roof of an adjacent wing.
Uneasy locations: complexities from a high school for formerly incarcerated men and women

The first part of this article situates and describes the conceptualization, implementation and ‘success’ of a project—an alternative high school for formerly incarcerated men and women—within the flourishing prison industrial complex in the United States, a structure that disproportionately impacts poor people and/or people of colour. The second part, snapshots/stories to break your heart offers two anecdotal “emotional striptease” (Fusco 2001) moments from the start of this project to illustrate the complexities that have arisen, or, simply, the need to do more. Finally, a brief postcript, outstanding in our field? that queries how I (and others in this project) struggle with negotiating the university/community relationships and the ‘hero’ trap.
Accelerated thermokarst formation in the McMurdo Dry Valleys, Antarctica

Thermokarst is a land surface lowered and disrupted by melting ground ice. Thermokarst is a major driver of landscape change in the Arctic, but has been considered to be a minor process in Antarctica. Here, we use ground-based and airborne LiDAR coupled with timelapse imaging and meteorological data to show that 1) thermokarst formation has accelerated in Garwood Valley, Antarctica; 2) the rate of thermokarst erosion is presently ~ 10 times the average Holocene rate; and 3) the increased rate of thermokarst formation is driven most strongly by increasing insolation and sediment/albedo feedbacks. This suggests that sediment enhancement of insolation-driven melting may act similarly to expected increases in Antarctic air temperature (presently occurring along the Antarctic Peninsula), and may serve as a leading indicator of imminent landscape change in Antarctica that will generate thermokarst landforms similar to those in Arctic periglacial terrains.
Catalytic and noncatalytic nucleotide binding sites of the Escherichia coli F1 ATPase Amino acid sequences of β‐subunit tryptic peptides labeled with 2‐azido‐ATP

Under appropriate conditions tight, noncovalent binding of 2-azido-adenine nucleotides to either catalytic or noncatalytic binding sites on the E. coli F1-ATPase occurs. After removal of unbound ligands, UV-irradiation results primarily in the covalent incorporation of nucleotide moieties into the β-subunit in both catalytic and noncatalytic site labeling experiments. Minor labeling of the α-subunit was also observed. After trypsin digestion and purification of the labeled peptides, microsequencing studies identified two adjacent β-subunit tryptic peptides labeled by 2-azido-ADP or -ATP. These β-subunit peptides were labeled on tyrosine-331 (catalytic sites) and tyrosine-354 (noncatalytic sites) in homology with the labeling patterns of the mitochondrial and chloroplast enzymes.
The cost of useful knowledge and collective action in three fisheries

article In a complex environment knowledge is valuable and its acquisition is costly; as a result people are careful about what to learn and how to learn it. We suggest that the dynamics of the "local" environment strongly influences the method that individuals choose to acquire useful knowledge and is one of the principal determinants of the waytheycompeteandcooperate.Wefocusonthewaydifferentenvironmentsleadtodifferentcosts,especiallythe relative opportunitycosts, of searchand communicationand,consequently,totheemergenceof different patternsof persistent cooperation and competition. In predictably regular and in predictably random environments, the cost of autonomous search is low and little social structure emerges. In complex environments, the relative costs of communication are high, leading to persistent social structure. Our presumption is that the characteristics of the emergent, or informal, social structure are a major determinant of successful collective action. We investigate the hypothesis through a comparison of three fisheries in which the costs of acquiring useful knowledge are different. Because of these differences, fishers' acquisition of useful knowledge leads to different social structure and different preconditions for successful collective action in each fishery. The lobster fishery is characterized by strong collective action and appears sustainable; the urchin and groundfisheries, worked by the same communities, are not even though almost all their participants are familiar with and often participate in the lobster fishery.
Teenagers' use of tobacco and their perceptions of tobacco control initiatives.

Background:Tobacco use leads to more deaths each year than any other single factor. This research examined teenagers' perceptions of anti-tobacco messages to determine which campaigns and educational approaches were most effective in preventing tobacco use among youth.Methods:Students from five rural high schools in western Pennsylvania were included in this survey-based study (N = 204).Results:A total of 30% of the study population reported current tobacco use. Tobacco users held more negative perceptions of anti-tobacco messages than non-users. A majority of students held supportive views about anti-tobacco education programs that were facilitated by peer leaders.Conclusions:Existing anti-tobacco campaigns and education are essential components of tobacco control initiatives. Students' perspectives provide novel insights that educators and campaign designers should consider as they develop anti-tobacco programs.
Apomorphine and dopamine D1 receptor agonists increase the firing rates of subthalamic nucleus neurons

The present study investigated the regulation of spontaneous neuronal activity in the subthalamic nucleus by dopamine receptors using in vivo extracellular single unit recording techniques. Subthalamic nucleus neuronal firing rates were doubled by systemic administration of the nonselective dopamine receptor agonist apomorphine. The response to apomorphine was attenuated in animals anesthetized with chloral hydrate or ketamine. The dopamine D(2)/D(3) receptor agonist quinpirole did not alter subthalamic nucleus neuronal firing rates. Firing rates were increased by the D(1) receptor agonists SKF 38393 and SKF 82958 two- to three-fold; these increases were reversed by the D(1) receptor antagonist, SCH 23390. Autoradiographic studies using [(125)I]SCH 23982 indicated that D(1) family receptors were located along the ventral edge of the subthalamic nucleus and the dorsal aspect of the cerebral peduncle. Local administration of SKF 82958 into the subthalamic nucleus doubled neuronal firing rates; these increases were reversed by systemic administration of SCH 23390. Infusion of SCH 23390 into the subthalamic nucleus prevented systemic SKF 38393 from increasing the firing rates of subthalamic nucleus neurons. These results indicate that apomorphine and D(1) receptor agonists exert an excitatory influence on subthalamic nucleus neuronal activity. In addition, the excitation induced by D(1) receptor agonists appears to be mediated, at least in part, by D(1) receptors located in the vicinity of the subthalamic nucleus. The data suggest that basal ganglia output under conditions of increased dopamine receptor stimulation is influenced by the activation of excitatory subthalamic efferent pathways, as opposed to suppression of these pathways as predicted by current models of basal ganglia function.
Chemical structure of phospholipids in the lungs and airways of sheep

Abstract Experiments on phospholipids from the alveolar lining, bronchi and trachea were conducted to support the concept that different lipid complexes are synthesized and released at different sites in the pulmonary system. Tracheal, bronchial and bronchioalveolar lavages were obtained from healthy adult Merino breed ewes following euthanasia and a structural analysis of the phospholipid fraction made by fast atom bombardment mass spectrometry. The major components in tracheal lavage were: 72% phosphatidylcholines (PC), 8% phosphatidylethanolamines (PE) and 11% phosphatidylglycerols (PG) compared to 78% PC, 13% PE and 3% PG in bronchioalveolar lavage. The fatty acid profile of tracheal lavage showed that 73% of the PG contained an arachidonic acid side chain. These species were not found in bronchioalveolar lavage. The nearly four-fold increase in PG, and the different molecular species identified in tracheal compared to bronchioalveolar lavage, suggest local synthesis and release of phospholipids by tracheal epithelia. The distribution of these phorpholipids may have functional properties desirable for normal mucociliary function and are consistent with published measurements from cultured tracheal epithelia cells.
Hypothalamic control of ovulation and behavioral estrus in the cat

Abstract The estrous cat ordinarily ovulates only after a complex mating behavior pattern which involves an elaborate afterreaction. The present experiments were designed to determine whether identical or separate hypothalamic areas control mating behavior and the release of an ovulatory surge of pituitary gonadotropin. With stereotaxic methods under chloralose anesthesia the hypothalamic of naturally estrous or estrogen-gonadotropin-primed queens were stimulated bilaterally in one of the following regions: medial basal hypothalamus including the premamillary area (MBH) and the anterior hypothalamus including both medial and lateral divisions (AH, MAH, LAH). At the end of the stimulation period (5 V, 30 c/s, 5 ms duration, 30 s on and 30 s off for 30 min) bilateral anodal electrolytic lytic lesions were made at the stimulation sites (3 mA for 30 s) with the central tips of the bipolar electrodes. Characteristically, ovulation was induced by stimulating the MBH but not the AH. Furthermore, the MBH lesions usually caused ovarian atrophy which led to anestrus, but the cats mated normally if supplied with exogenous estrogen. The anterior lesions left the ovaries in good trophic condion, and they could be ovulated by stimulating the MBH. However, the cats with anterior hypothalamic lesions in either the medial or lateral position repeatedly refused to accept the male even primed with exogenous estrogen. The results from these combined stimulation and lesion experiments in the female cat indicate that a hypothalamic sex behavioral area lies rostral to and discrete from a tubero-mamillary area controlling the release of pituitary gonadotropin.
Assignment of proximal histidine proton nmr peaks in myoglobin and hemoglobin

Summary The proton nmr spectra of model compounds of deoxy myoglobin and hemoglobin have yielded the assignment of the axial imidazole resonances. The information leads directly to an assignment of all three proximal histidyl imidazole proton resonances in sperm whale deoxy myoglobin, and the two non-equivalent proximal histidyl imidazole NH signals of the α and β chains in deoxy hemoglobin A. The NH peaks are expected to serve as valuable probes for the T ⇌ R transition in hemoglobins.
Determination of oxygen permeation kinetics in a ceramic membrane based on the composition SrFeCo0.5O3.25−δ

The oxygen permeation through an oxide ceramic membrane with bulk composition SrFeCo0.5O3.25−δ has been measured as a function of both temperature and the oxygen pressure gradient across the membrane. The form of the pressure gradient dependence of the permeation indicates that the oxygen transport in the membrane is dependent primarily on the bulk diffusion rate. Although the permeation experiments were carried out at temperatures within, or very close to, the range where SrFeCo0.5O3.25−δ is stable as a pure single phase in air, the membrane was found to consist of SrFe1.5−xCoxO3.25−δ (x=∼0.42) together with fractions of Sr(Co1−xFex)O2.5−δ perovskite and Co–Fe oxide. Phase stability experiments indicate these phases formed as a stable assemblage when the membrane was densified at high temperature (1090°C) during final processing. The assemblage persists at the lower temperatures of the permeation experiments most likely because of slow re-equilibration kinetics.
An adaptive routing protocol based on connectivity prediction for underwater disruption tolerant networks

Underwater Sensor Networks (UWSNs) are a desirable networking technique to facilitate various aquatic applications. However, the adverse characteristics of underwater communications and high cost of underwater sensor nodes limit UWSNs to sparse deployment, resulting in intermittent connectivity and therefore calling for techniques for Delay/Disruption Tolerant Networks (DTNs). To cope with disruptions, extra efforts have to be made in the routing protocol to provide transparent and robust end-to-end connections to upper-layer applications. In this paper, we propose a novel adaptive and energy-efficient routing protocol for underwater DTNs. By exploiting underwater node mobility patterns with adaptive filters, sensor nodes are able to estimate future contact events with other nodes in addition to the average contact probabilities over a prediction window. The proposed protocol is based on a distributed machine learning technique, Q-learning, which aims to select the most promising forwarders so as to minimize the end-to-end delay. Extensive simulations of the proposed protocol are carried out, and the results have shown that our protocol yields significantly better network performances and energy efficiency compared to other existing DTN routing protocols.