cssi/SciSciGPT-SciSciNet huggingface dataset:
Intraspecific variation of leaf pubescence and drought response in Encelia farinosa associated with contrasting desert environments

SUMMARY Traits associated with leaf energy balance are especially important for desert plants because decoupling leaf and ambient temperatures can be critical for maximizing productivity and survival in these hot, dry regions. Deserts are also one of the most climatically unpredictable and heterogeneous biomes; thus, variation of energy balance characters due either to plasticity or genetic differentiation might also be crucial to the success of desert plant species. In a common garden environment we examined variation in the traits associated with energy balance and productivity in Encelia farinosa A. Gray (brittlebush) plants. Comparing two populations from contrasting rainfall and drought climates, we found that plants from the wetter site (Superior, Arizona) always maintained higher leaf absorptances than plants from the more xeric region (Oatman, Arizona) when at similar water potentials. Superior plants also increased stomatal conductance and photosynthesis in response to mid-spring rainfall, whereas Oatman plants did not. Oatman plants, however, tended to have greater leaf areas and continuous spring growth, which made them larger than Superior plants, yet both populations produced the same number of flower heads. The differences for these traits, and the associations among them, agree with predictions based on the contrasting drought and rainfall environments of these two populations. Our results suggest that the differences might represent alternative suites of characters of selective importance for maximizing carbon gain over the climatically variable range of this widespread species. Furthermore, these differences, detected in common environment conditions, might have a genetic basis, which might contribute to a greater potential for local adaptation in this species.
Comment on "Dynamically maintained steady-state pressure gradients"

Sheehan [Phys. Rev. E 57, 6660 (1998)] recently discussed the possibility of establishing a dynamically maintained, steady-state pressure gradient in a gas filling a cavity. In this Comment it is pointed out that the pressure gradients in such a system, if attainable in the laboratory, could be used to violate the second law of thermodynamics.
STM study of CuCl2 intercalated in graphite

Abstract The surfaces of the CuCl2 graphite intercalation compounds (GIC's), uniform stage 1, were investigated in air using a scanning tunneling microscope. The carbon site asymmetry observed in STM images of pristine graphite is absent in the images of these GIC samples. For all samples we find no evidence for the STM bias voltage polarity affecting the images, contrary to reports in the literature. Furthermore, images provide no direct evidence of the intercalate islands associated with GIC's.
FEASIBILITY OF AN OPTICAL FREQUENCY MODULATION SYSTEM FOR FREE-SPACE OPTICAL COMMUNICATIONS

We consider a free-space communication system based on optical frequency modulation (FM), where the information is encoded by a time-variable wavelength. As is well known, broadband FM systems use a transmission bandwidth that is larger than the signal's information bandwidth, thus enabling an enhancement of the signal-to-noise ratio (SNR) and hence the effective information rate per unit transmitter power. Because of the atmospheric conditions, any optical free-space communication system, contemplated at a terrestrial level, must operate at mid-infrared wavelengths in the range λ = 2.5 2.8 μm. Development of rapidly tunable single-frequency lasers in this wavelength range is quite feasible, based on the current experience with tunable telecom lasers at 1.5 μm. Nevertheless, there is no currently available optical FM system. The main difficulty is associated not so much with the tunable optical sources, as with the implementation of a wavelength-discriminating receiver system that would take advantage of the enhanced SNR. In our view, the key enabling solution is optical superheterodyne with a local oscillator implemented as a tunable mid-infrared laser similar to that at the source. The intermediate frequency can be tuned to lie either in a frequency range directly accessible to electronic limiting amplifier and frequency discriminator or, in a multichannel system, to a second heterodyne in the terahertz range.
Deterioration behavior of thermomechanical refiner plates

Abstract To make paper from wood raw materials, wood chips must be processed to turn them into individual fibers or fiber bundles. In mechanical pulping this is accomplished by introducing energy into the wood chip or fiber bundles as the wood chips are passed between a set of counter-rotating plates; these are up to 1.5 m in diameter and operate with a plate clearance on the order of 0.1 mm and plate peripheral velocity of 130 m s −1 . The working life of refiner plates is sufficient for the paper industry; however, the deterioration of the fine surface detail of the plates reduces refining efficiency. This research was focused on the behavior of the plate materials in the refining environment, with the emphasis on understanding the deterioration behavior of the refiner plates. It combined wear analysis of normally used plates obtained from the paper mills, of plates used in designed trials in paper mills, and evaluation of plate materials in a broad range of laboratory tests. The laboratory tests were selected and suitably modified to reproduce phenomena observed on worn plates. The laboratory tests included cavitation erosion, dry-sand-rubber-wheel abrasion, and particulate erosion with high pressure water or steam as carrier fluids. Plate materials tested included 25Cr and 20Cr2Mo1Cu (both wt.%) high chromium white cast irons, Ni-hard white cast irons, and 440C and 17-4 PH stainless steels. Plate failure analysis revealed a variety of wear processes which varied with plate location and plate running time in the refiner. Cavitation erosion was clearly identified in the center of the plates where water was definitely present. Damage patterns with the same appearance as cavitation erosion were observed along plate bar edges near the periphery of the refiner plates where water is not thought to exist in a liquid form. Cavitation erosion tests in the laboratory duplicated the observed phenomena on the bar edges. Abrasion tests and erosion tests lacked such a close correlation to the observed phenomena. For all observed wear phenomena the role of the microstructure appears to be more important than the bulk hardness and for pitting-type damage such as that produced by cavitation erosion, the microstructure has a major influence on the wear process.
On Optimal Kernel Size for Integrated CPU-GPUs — A Case Study

Integrated CPU-GPU architectures with a fully addressable shared memory completely eliminate any CPU-GPU data transfer overhead. Since such architectures are relatively new, it is unclear what level of interaction between the CPU and GPU attains the best energy efficiency. Too coarse grained or larger kernels with fairly low CPU — GPU interaction could cause poor utilization of the shared resources while too fine grained kernels could cause frequent interrupts of GPU computation and performance degradation. Also larger kernels require larger shared resources causing increase in area and parasitics which affect the latency sensitive CPU cores. In this paper, we show the effect of granularity on the overall system's energy efficiency using a synthetic workload. We describe how our framework models a truly unified shared memory in integrated architectures with frequent CPU — GPU communication.
An artificial neural network-based approach to identifying mammalian fossil localities in the Great Divide Basin, Wyoming

Successful identification of fossil-bearing sedimentary deposits in the field typically requires expert knowledge in geology and anatomy and some degree of luck. One way to reduce the role of serendipity is to develop an empirical model that increases the likelihood of locating productive fossil-bearing deposits by identifying combinations of geological, geospatial and spectral features that are common to productive localities. In this example, a neural network classifier successfully identified Eocene mammalian fossil localities in the Great Divide Basin, Wyoming. This approach has broad implications for many other types of anthropological field research that also involve unique geospatially distributed phenomena.
Two independent retrotransposon insertions at the same site within the coding region of BTK.

Insertion of endogenous retrotransposon sequences accounts for approximately 0.2% of disease causing mutations. These insertions are mediated by the reverse transcriptase and endonuclease activity of long interspersed nucleotide (LINE-1) elements. The factors that control the target site selection in insertional mutagenesis are not well understood. In our analysis of 199 unrelated families with proven mutations in BTK, the gene responsible for X-linked agammaglobulinemia, we identified two families with retrotransposon insertions at exactly the same nucleotide within the coding region of BTK. Both insertions, an SVA element and an AluY sequence, occurred 12 bp before the end of exon 9. Both had the typical hallmarks of a retrotransposon insertion including target site duplication and a long poly A tail. The insertion site is flanked by AluSx sequences 1 kb upstream and 1 kb downstream and an unusual 60 bp sequence consisting of only As and Ts is located in intron 9, 60 bp downstream of the insertion. The occurrence of two retrotransposon sequences at exactly the same site suggests that this site is vulnerable to insertional mutagenesis. A better understanding of the factors that make this site vulnerable will shed light on the mechanisms of LINE-1 mediated insertional mutagenesis. © 2005 Wiley-Liss, Inc.
Magnetization transfer imaging with pulsed off‐resonance saturation: Variation in contrast with saturation duty cycle

Magnetization transfer contrast (MTC) can be generated in magnetic resonance images of water-containing macromolecular structures. Results obtained with the pulsed off-resonance saturation technique for achieving MTC are presented, allowing comparison of this technique with others. The magnetization transfer effect is demonstrated in newborn piglet brain and bovine muscle tissue, as well as in human subjects. MTC increases nonlinearly with the duty cycle of the off-resonance irradiation, approaching a maximum value corresponding to continuous irradiation. However, approximately half of the available contrast can be obtained at a given saturation offset frequency, with 16% irradiation duty cycle. Examples of MTC in various human tissues demonstrate the specificity of this technique at power levels within U.S. Food and Drug Administration guidelines. Plots of MTC versus the irradiation offset frequency demonstrate the effects of magnetization transfer and are compared with the curve generated by a control phantom that does not show magnetization transfer. Magnetization transfer imaging with pulsed off-resonance saturation is effective and easily implemented and may be useful in the investigation of saturation transfer phenomena in tissue.
Symbolic integration and autonomous state estimation: Building blocks for an intelligent power grid

This paper presents how symbolic computational approaches can be combined with advanced power system algorithms in order to implement advanced smart grid applications that will enable the modernization and the automation of the grid. We initially present a method for symbolically defining and integrating complex nonlinear dynamical systems in order to automatically compute the model of the devices that are connected to the power system, independently of their complexity. This generic form of the device model as computed by the “symbolic integrator” is then used as an input to numerous advanced real time power system applications. In this paper, an autonomous state estimator is presented as a demonstrative application. The proposed operational scheme is based on the combination of advanced state estimation algorithms that enable robotic (autonomous) power system operation. A laboratory setup is also presented to demonstrate the applicability of the proposed scheme.
Self-reported barriers to colorectal cancer screening in a racially diverse, low-income study population.

Colorectal cancer (CRC) screening is underutilized, especially in low income, high minority populations. We examined the effect test-specific barriers have on colonoscopy and fecal immunochemical test (FIT) completion, what rationales are given for non-completion, and what “switch” patterns exist when participants are allowed to switch from one test to another. Low income adults who were not up-to-date with CRC screening guidelines were recruited from safety-net clinics and offered colonoscopy or FIT (n = 418). Follow up telephone surveys assessed test-specific barriers. Test completion was determined from patient medical records. For subjects who desired colonoscopy at baseline, finding a time to come in and transportation applied more to non-completers than completers (p = 0.001 and p < 0.001, respectively). For participants who initially wanted FIT, keeping track of cards, never putting stool on cards, and not remembering to mail cards back applied more to non-completers than completers (p = 0.003, p = 0.006, and p < 0.001, respectively). The most common rationale given for not completing screening was a desire for the other screening modality: 7 % of patients who initially preferred screening by FIT completed colonoscopy, while 8 % of patients who initially preferred screening by colonoscopy completed FIT. We conclude that test-specific barriers apply more to subjects who did not complete CRC screening. As a common rationale for test non-completion is a desire to receive a different screening modality, our findings suggest screening rates could be increased by giving patients the opportunity to switch tests after an initial choice is made.
Atomic-resolution structures of horse liver alcohol dehydrogenase with NAD(+) and fluoroalcohols define strained Michaelis complexes.

Structures of horse liver alcohol dehydrogenase complexed with NAD+ and unreactive substrate analogues, 2,2,2-trifluoroethanol or 2,3,4,5,6-pentafluorobenzyl alcohol, were determined at 100 K at 1....
Applied sport psychology in an age of accountability

(1989). Applied sport psychology in an age of accountability. Journal of Applied Sport Psychology: Vol. 1, No. 2, pp. 166-180.
Immunolocalization of the keratinocyte growth factor in benign and neoplastic human prostate and its relation to androgen receptor.

BACKGROUND Growth and development of the prostate are androgen-dependent. Keratinocyte growth factor (KGF), widely expressed by mesenchymal cells, is thought to act like an andromedin between stroma and epithelium of the prostate. Since KGF has recently emerged as an autocrine mediator in prostate cancer, we investigated the role KGF plays in the human prostate and its relationship to androgen receptor (AR). METHODS Normal (n = 13), benign hyperplastic (n = 5), and neoplastic (n = 14) human prostate tissues as well as cultured epithelial and stromal cells were analyzed using polymerase chain reaction (PCR), Western blot analysis, and immunohistochemistry. RESULTS Reverse transcriptase polymerase chain reaction and Western blotting showed KGF expression in stromal cultured cells of the normal prostate but not in epithelial cells. Using immunohistochemistry, KGF was found to be localized in fibroblasts and smooth muscle cells, independent of prostate disease. There was KGF expression in epithelial cells of BPH and prostate cancer. Human androgen receptor was uniformly expressed in the same secretory glandular cells that were positive for KGF in BPH and prostate cancer. CONCLUSIONS Our results provide evidence that KGF is a stromal-derived mediator, recently shown to act in a paracrine manner in normal prostate but now detected in epithelial cells in prostate cancer and BPH. These findings support the hypothesis that KGF might act as an autocrine factor in prostate cancer and BPH. Prostate 41:233–242, 1999. © 1999 Wiley-Liss, Inc.
Recent incidence and secular trends in Hodgkin's disease and its histologic subtypes

Incidence data from national cancer surveys (1947, 1969-71, 1973-80) in selected regions of the United States were used to describe the epidemiology of Hodgkin's disease (HD) in whites over all regions by age, sex and Rye histologic subtype in the 1970s, and time trends for HD overall. Before 1971, rates increased in young adults, notably men, and in older persons. During the 1970s, rates in children were stable, but young adult rates were high and rose slightly, particularly among women; both trends reflected elevated incidence of Nodular Sclerosis, the only subtype with increasing rates. For adults over 40, rates of all subtypes declined after 1969-71. Thus HD incidence in this country is not static, even over the last decade. Rate stability in younger children may indicate disappearance of environmentally caused HD. Incidence declines for older persons suggest a cohort effect, depletion of young adult susceptibles, or improvements in diagnostic accuracy.
Synergy among agents inhibiting granulocyte aggregation.

Recent evidence suggests complement (C) -stimulated granulocytes (PMNs) are important in a variety of diseases, including shock and myocardial infarction (MI). Corticosteroids inhibit PMN response to C and show promise in some studies of shock and MI, but their use has not become routine for several reasons. Synergy was sought among agents inhibiting PMN aggregation in vitro in response to activated C: methylprednisolone (MP), with a 50% inhibitory dose (AD50) of 0.6 mg/ml; ibuprofen (IBU), with AD50 of 1.0 mg/ml, and betahistine (BH), with AD50 of 1.6 mg/ml. Simultaneous use of all three agents produced 3.4-fold synergy; 3-fold synergy obtained between IBU + MP and IBU + BH, while 1.5-fold synergy was noted between MP + BH. Further, MP and IBU were at least additive in inhibiting · O 2 − a generation by FMLP-stimulated PMNs and in blocking directed migration. In a preliminary in vivo test of this finding, cats were given MP and IBU—in known individually ineffective doses—immediately prior to coronary artery ligation. Neither MP nor the low dose of IBU chosen limited the size of the resultant MI, while both agents together reduced MI size by 42%. Synergy among these agents suggests that they inhibit PMN function of distinct cellular mechanisms (as yet not elucidated). Further, early in vivo results encourage speculation that such synergy might ultimately be exploited clinically, although such speculation must presently be regarded as preliminary.
Variables related to graduate students' Willingness to forgive a job-related transgression

43 graduate students' willingness, within a hypothetical situation, to forgive a friend whose negligent actions negatively affected their chances of getting a job was examined. Self-actualization, age, and general interpersonal closeness were proposed as possible variables related to these students' ratings of willingness to forgive while controlling for sex. A hierarchical multiple regression analysis showed this model predicted 23% of the variability in Forgiveness scores using self-actualization and age as significantly related to forgiveness in a positive direction, but with sex and general interpersonal closeness showing no significant relation.
Adolescent mental health consumers' self-stigma: associations with parents' and adolescents' illness perceptions and parental stigma

Currently, little is known about adolescents' self-stigma experiences as mental health (MH) treatment recipients. Hence, this study addresses the following two questions: (a) what are adolescents' and parents' perceptions of stigma and perceptions of the cause, controllability, and anticipated outcome (illness perceptions) of adolescents' MH problems? (b) to what extent do illness perceptions (adolescents and parents) and parents' own stigma experiences relate to adolescents' self-stigmatization? The results, based on data from separate interviews with a voluntary sample of 60 adolescent–parent dyads, clients of MH wraparound services, suggest that approximately 20% of adolescents and parents reported significant concerns related to self-stigmatization. Using multivariate analyses, we found that the three most prominent factors associated with adolescents' self-stigma ratings included adolescents' perceptions of social skill deficits and trauma as causal factors pertaining to their mental health challenges, as well as parents' inclination to conceal their child's MH problems from others. © 2010 Wiley Periodicals, Inc.
The photometric titration of nickel in the presence of cobalt

A spectrophotometric titration of nickel in the presence of cobalt is described using disodium ethylene diaminc tetraacetic acid as a titrant The end-point was obtained by plotting the corrected absorbancy against ml of titrant added Nickel concentrations of 2.5 to 25 mg were determined in the presence of up to 8 mg of cobalt with an error of 112% or less depending upon the concentration of Versenate used A 0.03M and 0.1M versenate was used The effects of pH, concentrations of nickel And cobalt, accuracy of the method, presence of interfering elements, and limitations of the method are discussed.
Polycrystalline Anatase Micro-Ring Resonators at Telecommunication Wavelengths

We fabricate and characterize integrated polycrystalline anatase TiO2 micro-ring resonators at around l = 1550 nm. We obtain quality factors of 1.5t10^4 and calculate a propagation loss of 8.0 p 1.3 dB/cm.
The Caribbean Carretera: Race, Space and Social Liminality in Costa Rica

A single highway connects the Caribbean province of Limon to mainstream society in the highlands of Costa Rica. This paper explores the ways in which that highway affects the status hierarchy of mainstream society in Costa Rica, and how the construction of whiteness as an unexamined racial qualifier for total social incorporation constrains the perception of blacks as social liminars and blackness as a state of communitas. The argument elaborates the work of Victor Turner on ritual liminality to suggest the structural ambiguity of Afro-Latin Americans in the context of Costa Rica.
Phylogenetic diversity among low-virulence newcastle disease viruses from waterfowl and shorebirds and comparison of genotype distributions to those of poultry-origin isolates

Low-virulence Newcastle disease viruses (loNDV) are frequently recovered from wild bird species, but little is known about their distribution, genetic diversity, or potential to cause disease in poultry. NDV isolates recovered from cloacal samples of apparently healthy waterfowl and shorebirds (WS) in the United States during 1986 to 2005 were examined for genomic diversity and their potential for virulence (n = 249). In addition 19 loNDV isolates from U.S. live bird markets (LBMs) were analyzed and found to be genetically distinct from NDV used in live vaccines but related to WS-origin NDV. Phylogenetic analysis of the fusion protein identified nine novel genotypes among the class I NDV, and new genomic subgroups were identified among genotypes I and II of the class II viruses. The WS-origin viruses exhibited broad genetic and antigenic diversity, and some WS genotypes displayed a closer phylogenetic relationship to LBM-origin NDV. All NDV were predicted to be lentogenic based upon sequencing of the fusion cleavage site, intracerebral pathogenicity index, or mean death time in embryo assays. The USDA real-time reverse transcription-PCR assay, which targets the matrix gene, identified nearly all of the class II NDV tested but failed to detect class I viruses from both LBM and WS. The close phylogenetic proximity of some WS and LBM loNDV suggests that viral transmission may occur among wild birds and poultry; however, these events may occur unnoticed due to the broad genetic diversity of loNDV, the lentogenic presentation in birds, and the limitations of current rapid diagnostic tools.
Geodynamics and Ore Deposit Evolution in Europe.D. Blundell, N. Arndt, P. R. Cobbold, and C. Heinrich, Editors. Elsevier. 2005. 360 Pp. ISBN: 0-444-52233-6. Price $135.

The aim of this volume, as emphasized in the preface and introduction, is to relate the major ore deposits of Europe to the geodynamic evolution of their host region. The editors hope such material will provide the explorationist with a new way of viewing and understanding regional metallogeny. Most of the research results presented in the book have been supported since 1996 by the European Science Foundation’s program on Geodynamics and Ore Deposit Evolution (GEODE). The program successfully brought together leading economic geologists as well as workers in other fields of the earth sciences from throughout the European community to jointly research and author the eight chapters on five of the most economically significant metallogenic provinces in Europe. Obviously these are major, long-term collaborative efforts between workers from many different countries; however, I was surprised to find that none of the eight major chapters have any coauthors listed with affiliations in industry, despite the statement in the preface (written by a steering committee from industry) that these reflect academia-industry collaborations. The first three chapters of the book are focused on the metallogeny of the highly prospective Alpine-Balkan-Carpathian-Dinaride (ABCD) geodynamic province. Neubauer et al. describe the important epithermal, porphyry, and skarn deposits in the northern part to the province, which include those of the South Apuseni Mountains, Baia Mare (eastern Carpathians), Central Slovakia, and Styrian (eastern Alps) districts. The Neogene ores and associated magmatism are related to processes of slab subduction, roll-back, and detachment. Marchev et …
Structures for handling high heat fluxes

Abstract The divertor is reconized as one of the main performance limiting components for ITER. This paper reviews the critical issues for structures that are designed to withstand heat fluxes > 5 MW/m2. High velocity, sub-cooled water with twisted tape inserts for enhanced heat transfer provides a critical heat flux limit of 40–60 MW/m2. Uncertainties in physics and engineering heat flux peaking factors require that the design heat flux not exceed 10 MW/m2 to maintain an adequate burnout safety margin. Armor tiles and heat sink materials must have a well matched thermal expansion coefficient to minimize stresses. The divertor lifetime from sputtering erosion is highly uncertain. The number of disruptions specified for ITER must be reduced to achieve a credible design. In-situ plasma spray repair with thick metallic coatings may reduce the problems of erosion. Runaway electrons in ITER have the potential to melt actively cooled components in a single event. A water leak is a serious accident because of steam reactions with hot carbon, beryllium, or tungsten that can mobilize large amounts of tritium and radioactive elements. If the plasma does not shutdown immediately, the divertor can melt in 1–10 s after a loss of coolant accident. Very high reliability of carbon tile braze joints will be required to achieve adequate safety and performance goals. Most of these critical issues will be addressed in the near future by operation of the Tore Supra pump limiters and the JET pumped divertor. An accurate understanding of the power flow out of edge of a DT burning plasma is essential to successful design of high heat flux components.
Science Professional Learning Communities: Beyond a singular view of teacher professional development

Professional Learning Communities (PLCs) are frequently being used as a vehicle to transform science education. This study explored elementary teachers' perceptions about the impact of participating in a science PLC on their own professional development. With the use of The Science Professional Learning Communities Survey and a semi-structured interview protocol, elementary teachers' perceptions of the goals of science PLCs, the constraints and benefits of participation in PLCs, and reported differences in the impact of PLC participation on novice and experienced teachers were examined. Sixty-five elementary teachers who participated in a science PLC were surveyed about their experiences, and a subsample of 16 teachers was interviewed. Results showed that most of the teachers reported their science PLC emphasized sharing ideas with other teachers as well as working to improve students' science standardized test scores. Teachers noted that the PLCs had impacted their science assessment practices as well as...
Advice from Multiple Experts: A Comparison of Simultaneous, Sequential, and Hierarchical Communication

In this paper, I analyze an example in which two perfectly informed experts advise a decision maker. Each expert has private information about her own bias. I show that consulting two experts is better than consulting just one. I compare the efficiency of information transmission between simultaneous, sequential, and hierarchical forms of communication. I show that simultaneous communication achieves the highest efficiency, followed by sequential and hierarchical communication. However, hierarchical communication, in which a second expert chooses whether to block the first expert's message, achieves a moderate level of efficiency, even though the decision maker receives only one message. Finally, there are preference settings in which both sequential and hierarchical communication are superior to simultaneous communication.
Artificial intelligence techniques for tuning linear induction accelerators

An expert system has been developed that acts as an intelligent assistant for tuning particle beam accelerators. This system is called MAESTRO-Model and Expert System Tuning Resource for Operators. MAESTRO maintains a knowledge base of the accelerator containing not only the interconnections of the beamline components, but also their physical attributes such as measured magnetic tilts, offsets, and field profiles. MAESTRO incorporates particle trajectory and beam envelope models which are coupled to the knowledge base permitting large number of real-time orbit and envelope calculations in the control-room environment. This capability has been used (1) to implement a tuning algorithm for minimizing transverse beam motion, (2) to produce a beam waist with arbitrary radius at the entrance to a brightness diagnostic, and (3) to measure beam energy along the accelerator by fitting orbits to focusing and steering sweeps. >
Uniform magnetic fields and double-wrapped coil systems: Improved techniques for the design of bioelectromagnetic experiments

A common mistake in biomagnetic experimentation is the assumption that Helmholtz coils provide uniform magnetic fields; this is true only for a limited volume at their center. Substantial improvements on this design have been made during the past 140 years with systems of three, four, and five coils. Numerical comparisons of the field uniformity generated by these designs are made here, along with a table of construction details and recommendations for their use in experiments in which large volumes of uniform intensity magnetic exposures are needed. Double-wrapping, or systems of bifilar windings, can also help control for the non-magnetic effects of the electric coils used in many experiments. In this design, each coil is wrapped in parallel with two separate, adjacent strands of copper wire, rather than the single strand used normally. If currents are flowing in antiparallel directions, the magnetic fields generated by each strand will cancel and yield virtually no external magnetic field, whereas parallel currents will yield an external field. Both cases will produce similar non-magnetic effects of ohmic heating, and simple measures can reduce the small vibration and electric field differences. Control experiments can then be designed such that the only major difference between treated and untreated groups is the presence or absence of the magnetic field. Double-wrapped coils also facilitate the use of truly double-blind protocol, as the same apparatus can be used either for experimental or control groups.
Research Note: In Ovo Administration of a Competitive Exclusion Culture Treatment to Broiler Embryos

Abstract Exposure of chicks to salmonellae in the hatchery and hatchery environment limits the effectiveness of a competitive exclusion (CE) culture treatment. Therefore, in an attempt to apply treatment before chicks are exposed to salmonellae, the CE culture was introduced in ovo to unhatched embryos. An undefined, anaerobically grown CE culture, derived from cecal contents of healthy adult chickens, was diluted 1:1,000 or 1:1,000,000 and inoculated either into the air cell or beneath the inner air cell membrane of 17-day-old incubating hatching eggs. The treated chicks were more resistant than untreated chicks to varying challenge levels of Salmonella typhimurium, indicating that it may be possible to initiate protection of chicks to salmonellae challenge prior to hatching into a contaminated environment.
Reovirus Induction of and Sensitivity to Beta Interferon in Cardiac Myocyte Cultures Correlate with Induction of Myocarditis and Are Determined by Viral Core Proteins

Reovirus-induced acute myocarditis in mice serves as a model to investigate non-immune-mediated mechanisms of viral myocarditis. We have used primary cardiac myocyte cultures infected with a large panel of myocarditic and nonmyocarditic reassortant reoviruses to identify determinants of viral myocarditic potential. Here, we report that while both myocarditic and nonmyocarditic reoviruses kill cardiac myocytes, viral myocarditic potential correlates with viral spread through cardiac myocyte cultures and with cumulative cell death. To address the role of secreted interferon (IFN), we added anti-IFN-a/b antibody to infected cardiac myocyte cultures. Antibody benefited nonmyocarditic more than myocarditic virus spread (P < 0.001), and this benefit was associated with the reovirus M1 and L2 genes. There was no benefit for a differentiated skeletal muscle cell line culture (C2C12 cells), suggesting cell type specificity. IFN-b induction in reovirus-infected cardiac myocyte cultures correlated with viral myocarditic potential (P 5 0.006) and was associated with the reovirus M1, S2, and L2 genes. Sensitivity to the antiviral effects of IFN-a/b added to cardiac myocyte cultures also correlated with viral myocarditic potential (P 5 0.004) and was associated with the same reovirus genes. Several reoviruses induced IFN-b levels discordant with their myocarditic phenotypes, and for those tested, sensitivity to IFN-a/b compensated for the anomalous induction levels. Thus, the combination of induction of and sensitivity to IFN-a/b is a determinant of reovirus myocarditic potential. Finally, a nonmyocarditic reovirus induced cardiac lesions in mice depleted of IFN-a/b, demonstrating that IFN-a/b is a determinant of reovirus-induced myocarditis. This provides the first identification of reovirus genes associated with IFN induction and sensitivity and provides the first evidence that IFN-b can be a determinant of viral myocarditis and reovirus disease.
Summary of Paper on Future of Braille

Although the population of blind persons is increasing, the use of braille as a reading, writing, and communication medium is declining. The reasons for this curious situation lie not only in benign neglect of the medium, but also in poor teaching, inadequate mix of materials needed, long ignored difficulties in the braille code, and lack of national debate on the issues involved. This paper tracks the major consequences of difficulties resulting from the above causes, gives brief descriptions of the problems involved, and suggests one or more solutions to each of the problems. As a system analysis of the production, deployment, and use of the braille medium, the paper is intended to provoke discussion about the problems treated, not to provide unique solutions of them.
Cannabis Use during Adolescent Development: Susceptibility to Psychiatric Illness.

Cannabis use is increasingly pervasive among adolescents today, even more common than cigarette smoking.The evolving policy surrounding the legalization of cannabis reaffirms the need to understand the relationship between cannabis exposure early in life and psychiatric illnesses. cannabis contains psychoactive components, notably 9 D -tetrahydrocannabinol (THC), that interfere with the brain's endogenous endocannabinoid system, which is crit- ically involved in both pre- and post-natal neurodevelopment. Consequently, THC and related compounds could potentially usurp normal adolescent neurodevelopment, shift- ing the brain's developmental trajectory toward a disease-vulnerable state, predisposing early cannabis users to motivational, affective, and psychotic disorders. Numerous human studies, including prospective longitudinal studies, demonstrate that early cannabis use is associated with major depressive disorder and drug addiction. A strong association between schizophrenia and cannabis use is also apparent, especially when considering genetic factors that interact with this environmental exposure. These human studies set a foundation for carefully controlled animal studies which demonstrate similar pat- terns following early cannabinoid exposure. Given the vulnerable nature of adolescent neurodevelopment and the persistent changes that follow early cannabis exposure, the experimental findings outlined should be carefully considered by policymakers. In order to fully address the growing issues of psychiatric illnesses and to ensure a healthy future, measures should be taken to reduce cannabis use among teens.
The Dynamic Fracture Toughness of Carbon-Carbon Composites

The dynamic fracture toughness of two types of carbon-carbon com posites (filament wound and felt substrate) and ATJ-S graphite was deter mined from instrumented Charpy impact tests. The resistance to crack initiation from a pre-existing flaw (notch) was examined by investigating the dynamic fracture toughness, KD, a linear elastic fracture mechanics parameter. The resistance to crack initiation and propagation was deter mined using the dynamic work-of-fracture parameter, γfD. Testing was conducted over a range of impact velocities (4.0-202.8 in/sec), and the parameters KD and γfD were found to be strongly sensitive to impact velocity for all three materials. As expected, the dynamic fracture tough ness of the highly anisotropic filament wound carbon-carbon composite was dependent on filament orientation.
Application of empirical orthogonal functions to evaluate ozone simulations with regional and global models

[1] Empirical orthogonal functions are used together with standard statistical metrics to evaluate the ability of models with different spatial resolutions to reproduce observed patterns of surface ozone (O3) in the eastern United States in the summer of 1995. We examine simulations with the regional Multiscale Air Quality Simulation Platform model (horizontal resolution of 36 km2) and the global GEOS-CHEM model (2° × 2.5° and 4° × 5°). As the model resolution coarsens, the ability to resolve local O3 maxima (O3 ≥ 90 ppbv) is compromised, but the spatial correlation improves. This result shows that synoptic-scale processes modulating O3 concentrations are easier to capture in models than processes occurring on smaller scales. Empirical orthogonal functions (EOFs) derived from the observed O3 fields reveal similar modes of variability when averaged onto the three model horizontal resolutions. The EOFs appear to represent (1) an east-west pattern associated with frontal passages, (2) a midwest-northeast pattern associated with migratory high-pressure systems, and (3) a southeast stagnation pattern linked to westward extension of the Bermuda High. All models capture the east-west and southeast EOFs, but the midwest-northeast EOF is misplaced in GEOS-CHEM. GEOS-CHEM captures the principal components of the observational EOFs when the model fields are projected onto these EOFs, implying that it can resolve the contribution of the EOFs to the observed variance. We conclude that coarse-resolution global models can successfully simulate the synoptic conditions leading to high-O3 episodes in the eastern United States.
Performance Evaluation of Geometric Feature Descriptors With Application to Classification of Small-Size Lung Nodules in Low Dose CT

Object modeling is a multifaceted and active area of research in image analysis, manufacturing, and computational geometry. In image analysis, the focus of this paper, objects may be described in terms of their shape and appearance. Geometric features that are invariant to scale, rotation and translation are essential for proper modeling of shape. Deformable random objects, common in biomedical imaging, do not carry distinct features and suffer from multiple sources of uncertainty, including resolution, size, location and occlusion. Registration involves generating the transformation parameters for mapping a source to a target, while categorization involves matching entities into classes. Both processes, involve mapping attributes of objects with respect to each other, and robust features together with proper similarity measures are keys for good performance. This article examines the issues of features, similarity measures for registration and categorization of small-size deformable random objects; a case study of lung nodules in chest CT is used as an example. We show that feature descriptors capturing textural contents are more effective for these types of objects. The paper includes survey and evaluations of several modern feature descriptors that have been introduced in the computer vision and image analysis literature.
Higher radix floating-point representations for FPGA-based arithmetic

FPGA implementations of floating-point operators have historically been designed to use binary floating-point representations. The general computing world settled on binary floating-point representations over three decades ago, and more recently, the FPGA community followed their example. Binary representations were chosen to maximize numerical accuracy per bit of data, however, the unique nature of FPGA-based computation makes numerical accuracy per unit of FPGA resources a more important measure of the usefulness of a given floating-point representation. In this paper, we show that higher radix floating-point representations are well suited to FPGA-based computations, especially high precision calculations which require the support of denormalized numbers. Higher radix representations use FPGA resources more efficiently. For example, a hexadecimal floating-point adder has a 30% smaller area-time product than its binary counterpart, while still delivering equal worst-case and better average-case numerical accuracy. Contrary to established belief, higher radix representations are useful for FPGA applications requiring IEEE 754 compliance, since they can deliver superior numerical performance while still using less FPGA resources.
A comparison of culture-positive and culture-negative health-care-associated pneumonia.

Objective The aim of this study is to describe the initial antibiotic treatment regimens, severity of illness, and in-hospital mortality among culture-negative (CN) and culture-positive (CP) patients with health-care-associated pneumonia (HCAP). Methods We used a retrospective cohort study, examining adult patients with HCAP from Barnes-Jewish Hospital, a 1,200-bed urban teaching hospital. Results Eight hundred seventy patients with HCAP were identified over a 3-year period (January 2003 through December 2005) of whom 431 (49.5%) were CP. Among the non-CP patients, 290 (66.1%) had no respiratory cultures obtained, and 149 (33.9%) had no growth or nonpathogenic oral flora identified and were classified as CN. CN patients were more likely to have received an initial antibiotic regimen (ceftriaxone ± azithromycin or moxifloxacin) targeting community-acquired pneumonia pathogens compared with CP patients (71.8% vs 25.5%, P P P P P Conclusions In this analysis, patients with CN HCAP had lower severity of illness, hospital mortality, and hospital length of stay compared with CP patients. These data suggest that patients with CN HCAP differ substantially from patients with HCAP with positive microbiologic cultures.
3-d lung deformation and function from respiratory-gated 4-d x-ray ct images: application to radiation treatment planning

Many lung diseases or injuries can cause biomechanical or material property changes that can alter lung function. While the mechanical changes associated with the change of the material properties originate at a regional level, they remain largely asymptomatic and are invisible to global measures of lung function until they have advanced significantly and have aggregated. In the realm of external beam radiation therapy of patients suffering from lung cancer, determination of patterns of pre- and post-treatment motion, and measures of regional and global lung elasticity and function are clinically relevant. In this dissertation, we demonstrate that 4-D CT derived ventilation images, including mechanical strain, provide an accurate and physiologically relevant assessment of regional pulmonary function which may be incorporated into the treatment planning process. Our contributions are as follows: (i) A new volumetric deformable image registration technique based on 3-D optical flow (MOFID) has been designed and implemented which permits the possibility of enforcing physical constraints on the numerical solutions for computing motion field from respiratory-gated 4-D CT thoracic images. The proposed optical flow framework is an accurate motion model for the thoracic CT registration problem. (ii) A large displacement landmark-base elastic registration method has been devised for thoracic CT volumetric image sets containing large deformations or changes, as encountered for example in registration of pre-treatment and post-treatment images or multi-modality registration. (iii) Based on deformation maps from MOFID, a novel framework for regional quantification of mechanical strain as an index of lung functionality has been formulated for measurement of regional pulmonary function. (iv) In a cohort consisting of seven patients with non-small cell lung cancer, validation of physiologic accuracy of the 4-D CT derived quantitative images including Jacobian metric of ventilation, VJac and principal strains, ( Vl1,Vl2 ,Vl3 ), has been performed through correlation of the derived measures with SPECT ventilation and perfusion scans. The statistical correlations with SPECT have shown that the maximum principal strain pulmonary function map derived from MOFID, outperforms all previously established ventilation metrics from 4D-CT. It is hypothesized that use of CT-derived ventilation images in the treatment planning process will help predict and prevent pulmonary toxicity due to radiation treatment. It is also hypothesized that measures of regional and global lung elasticity and function obtained during the course of treatment may be used to adapt radiation treatment. Having objective methods with which to assess pre-treatment global and regional lung function and biomechanical properties, the radiation treatment dose can potentially be escalated to improve tumor response and local control.