cssi/SciSciGPT-SciSciNet huggingface dataset:
Gating of population flow in resonant multiphoton excitation

I discuss the flow of excitation probability along a multistate chain of resonant excitations as driven by coherent photoexcitation, in particular the gated interruption of this probability flow caused by a strongly coupled side branch. If the side branch is itself a chain, not a single transition, then flow inhibition occurs if the number of branch transitions is odd, but no inhibition occurs if the number is even. The inhibition provides a limiting bound on the intensity of amplified stimulated emission.
Early Activation of Mitogen-Activated Protein Kinase Kinase, Extracellular Signal-Regulated Kinase, p38 Mitogen-Activated Protein Kinase, and c-JunN-Terminal Kinase in Response to Binding of Simian Immunodeficiency Virus to Jurkat T Cells Expressing CCR5 Receptor

Abstract We have shown that the binding of simian immunodeficiency virus (SIV) to Jurkat T cells expressing CD4 receptor strongly induces mitogen-activated protein (MAP) kinase kinase (MEK) and extracellular signal-regulated kinases 1 and 2 (ERK1/2) and only weakly induces p38 MAP kinase and c-JunN-terminal kinase (JNK). Similarly, T-tropic NL4–3 virus, which uses both CD4 and CXCR4 receptors for entry, stimulated in these cells the MEK/ERK MAP kinase (MAPK) pathway in a CD4 receptor-dependent manner (Popik and Pitha, 1998). In contrast, both macrophage-tropic SIVmac316 and T cell-tropic SIVmac239, which in addition to CD4 require CCR5 coreceptor for entry, significantly enhanced early MEK/ERK, p38 MAPK, and JNK signaling in Jurkat cells expressing constitutively or transiently the CCR5 receptor. Together, this study provides the evidence that viruses using CXCR4 or CCR5 receptors for entry may differentially use signaling properties of their specific coreceptors to stimulate MAP kinase cascades. In addition, although SIVmac239 and SIVmac316 use different structural domains of the CCR5 receptor for entry, both viruses stimulate early phosphorylation of MEK, ERK, p38, and JNK independently of their tropism and replication.
The need for accuracy in modelling: An example

Abstract The need for accurate information in modelling depends on the objectives of the effort, but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key assumptions are not supported by biological evidence, and that inferences drawn from the mmodel could be dangerously misleading if they were used to guide the management of canvasback ducks.
Increased process stability for CVD tungsten via in-situ particle monitoring and upstream process control

Upstream control and in-situ defect monitoring have been successfully implemented to track and improve particle performance for CVD tungsten films. An in-situ 'dark field' particle sensor was used to monitor process defect levels during tungsten deposition. The sensor was mounted directly below the CVD tungsten deposition chamber on the foreline. Information from the in-situ particle sensor and the CVD system process parameter analog output were routed to a stand alone computer where the incoming signals were recorded. In-situ particle and process parameter signals were monitored using the standard production recipe for tungsten deposition. From this data the internal variables (process parameters) affecting in-situ particle levels were determined. The internal factors were varied over a selected operating range and the in-situ particle levels quantified for each factor. These results were used to define the CVD tungsten process operating window in terms of in-situ defectivity. Additionally, other external sources were identified as contributors to in-situ defectivity.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Magnetoemission experiments in Pb1−cSnxTe

Abstract Reduced effective masses and g -factor magnitudes inPb 1−x Sn x Te (0 ≤ x ≤0.27) are deduced from the dependence of the emission spectra on magnetic fields. Their band gap dependence is as expected if valence-conduction band interaction provides the primary contribution, with higher and lower lying bands having a lesser, but significant, effect.
A formal mentorship program for faculty development.

Objective. To describe the development, implementation, and evaluation of a formal mentorship program at a college of pharmacy. Methods. After extensive review of the mentorship literature within the health sciences, a formal mentorship program was developed between 2006 and 2008 to support and facilitate faculty development. The voluntary program was implemented after mentors received training, and mentors and proteges were matched and received an orientation. Evaluation consisted of conducting annual surveys and focus groups with mentors and proteges. Results. Fifty-one mentor-protege pairs were formed from 2009 to 2012. A large majority of the mentors (82.8%-96.9%) were satisfied with the mentorship program and its procedures. The majority of the proteges (≥70%) were satisfied with the mentorship program, mentor-protege relationship, and program logistics. Both mentors and proteges reported that the proteges most needed guidance on time management, prioritization, and work-life balance. While there were no significant improvements in the proteges’ number of grant submissions, retention rates, or success in promotion/tenure, the total number of peer-reviewed publications by junior faculty members was significantly higher after program implementation (mean of 7 per year vs 21 per year, p=0.03) in the college’s pharmacy practice and administration department. Conclusions. A formal mentorship program was successful as measured by self-reported assessments of mentors and proteges.
Superresolution and convergence properties of the expectation-maximization algorithm for maximum-likelihood deconvolution of incoherent images

Computational optical-sectioning microscopy with a nonconfocal microscope is fundamentally limited because the optical transfer function, the Fourier transform of the point-spread function, is exactly zero over a conic region of the spatial-frequency domain. Because of this missing cone of optical information, images are potentially artifactual. To overcome this limitation, superresolution, in the sense of band extrapolation, is necessary. I present a frequency-domain analysis of the expectation-maximization algorithm for maximum-likelihood image estimation that shows how the algorithm achieves this band extrapolation. This analysis gives the theoretical absolute bandwidth of the restored image; however, this absolute value may not be realistic in many cases. Then a second analysis is presented that assumes a Gaussian point-spread function and a specimen function and shows more realistic behavior of the algorithm and demonstrates some of its properties. Experimental results on the superresolving capability of the algorithm are also presented.
The influence of moisture on the electrical performance of XLPE/silica nanocomposites

Moisture is known to influence the electrical performance of polymers. The introduction of nano particulates creates numerous additional pathways which radically affect the migration of moisture in nanocomposite materials. In this paper, cross-linked polyethylene/silica nanocomposites at loadings of 5 wt% and 12.5 wt% of both unfunctionalized and vinylsilane-functionalized nano silica were exposed to humid environments at elevated temperature. Nanocomposites were found to have a much higher moisture uptake compared to cross-linked polyethylene base resin. The dielectric properties of these hydrothermal conditioned samples were characterized by breakdown strength measurements, pulsed electro-acoustic analysis, and dielectric spectroscopy. A close relationship between particle loading, moisture uptake and dielectric properties was found, which provides important evidence that determining the optimal particle loading of nanodielectrics should take moisture influence into account.
Genotypic investigation of multidrug-resistant Acinetobacter baumannii infections in a medical intensive care unit

Abstract Multi-resistant Acinetobacter baumannii isolates obtained from 13 hospitalized patients over a six-month period were evaluated. One patient had an isolate susceptible only to imipenem; the next three had isolates susceptible to imipenem and ampicillin/sulbactam; the next six patients had isolates which were susceptible to imipenem, amikacin, and ampicillin/ sulbactam; while the final three patients had isolates which were susceptible to imipenem and ampicillin/sulbactam. Ten patients died, five within 10 days of a positive culture. Five of six patients with bacteraemia succumbed to the infection. DNA extracted from all isolates was amplified by polymerase chain reaction using four random primers (RAPD). The resulting band patterns were compared and strains identified. In addition, all isolates were biotyped. RAPD analysis and biotyping showed that there were two distinct strains involved. The first four patients were infected with one strain (genotype ‘A', biotype 9), the subsequent nine patients were infected with a second strain (genotype ‘B', biotype 1). These results suggested that there was patient-to-patient spread of strains. Institution of, and strict adherence to, isolation procedure and other infection control practices controlled the spread of infection. These data emphasize the need for active surveillance for multidrug-resistant organisms in critically ill patients, and the value of molecular typing of strains in a hospital setting to investigate spread of infection.
Photonic Electric-Field Probe For Frequencies Up To 2 GHz

A photonic electric field probe using the Pockels effect in bulk LiNbO 3 is used to measure electromagnetic fields from 10 to 100 V/m. The observed frequency response is flat up to 1.6 GHz and extends beyond 2 GHz. Over the majority of the frequency range, field strengths down to about 6 V/m would be detectable above the noise floor when using a 3 kHz detection bandwidth. Present experimental results indicate a linear dynamic range of 30 dB for the probe. Increasing the optical carrier power and lowering the noise floor are expected to improve the dynamic range to above 50 dB.
Shear displacement of the K(110) surface.

A low-energy electron diffraction analysis of the clean K(110) surface has been performed at 25 K, providing a quantitative structural determination of a clean alkali-metal surface. The K(110) surface exhibits a novel surface phase consisting of a lateral shear displacement between the first two surface planes while preserving their two-dimensional periodicity. The atomistic description of this surface structure is related to that of the bulk martensitic phase transitions of the alkali metals.
Mucin-producing parathyroid carcinoma

A 67-year-old white male presented with symptomatic hypercalcemia (15.6 mg/dl) in December 1989. He had undergone thyroidectomy for removal of a mucin-producing adenocarcinoma of the thyroid in 1967, and after eight years of follow-up during which time no other neoplasms were detected, he was reported as a unique case of this syndrome. Mild hypercalcemia (less than 11.0 mg/dl) was first noted in 1987, and this had remained stable until shortly before the acute presentation. Multiple lung nodules were observed radiographically and presumed to be granulomatous until increased size was observed shortly before presentation. Serum intact PTH was 190 pg/ml (n 10-55), but at neck exploration no parathyroid tissue was found and surgery did not resolve the hypercalcemia. Serum PTHrP was undetectable. Biopsies from all three lobes of the right lung revealed numerous nodules of metastatic adenocarcinoma with cords of tumor cells surrounded by mucin. The histology was similar to that obtained 23 years earlier. Following left upper lobe resection with removal of a 3-cm nodule, hypercalcemia resolved. The tumor stained strongly positive with a peroxidase stain for PTH using a polyclonal antibody. Northern blot hybridization of total RNA from the tumor confirmed the presence of message for PTH but not PTHrP. The original diagnosis has been revised to that of a unique case of mucin-producing parathyroid cancer with an extraordinarily long latency period before recurrence.
The effects of interpersonal and concept compatibility on the encoding behavior and achievement of debate teams

This article presents the findings of a study designed to assess the effects of two types of colleague compatibility on the performance of debate teams.
P03.05. Creating an interprofessional curriculum in integrative medicine for medical, nursing, pharmacy, and dentistry students: curriculum mapping strategies

Purpose An increasing number of academic health institutions are committed to integrative medicine (IM) principles, including partnership between patient and practitioner; collaborative, interprofessional health care; and promotion of health and the prevention of illness. The objective of this five-year project is to develop, implement, evaluate, and disseminate a multidisciplinary, interprofessional curriculum in IM. Our first aim was to map the existing IM curricula to examine the content longitudinally within each school, as well as across schools. To do this, we added to traditional curriculum mapping methods by eliciting faculty and students’ perspectives through interviews.
Nonresponse Bias in Organizational Surveys: Evidence from a Survey of Groups and Organizations Working for Peace

Nonresponse bias is a major concern for scholars using survey research, as low response rates can lead to serious problems in the generalizability of survey results. Numerous studies have been made to estimate the effects of nonresponse bias on survey results, but these have typically considered only surveys treating individual respondents as the unit of analysis. Organizational theory should lead scholars, however, to expect important differences between individual and organizational survey designs in the sources and effects of nonresponse bias. In this article, the author compares characteristics of organizations responding to a survey of organizations working for peace with those of organizations that failed to respond. The analysis shows that organizational informants behave differently from individual survey targets and that a theory of nonresponse bias in organizational surveys is needed to improve organizational survey designs so as to minimize and account for nonresponse bias.
Diplopia After Topical Pharyngeal Anesthesia For Transesophageal Echocardiography

a. Pharyngeal topical anesthesia is widely used during transesophageal echocardiography (TEE). Although generally regarded as safe, topical anesthetic administration has been shown to have various complications, mostly reported during endoscopy and bronchoscopy procedures but also during TEE. Topical anesthesia can be complicated by toxic methemoglobinemia 1-3 and, when absorbed systemically, can result in severe, lifethreatening systemic toxicity. 4,5 Hypersensitivity reactions are rare and are usually attributed to preservatives and anesthetic components in the preparation. We report an unusual case of transient isolated diplopia in a patient who underwent TEE with topical anesthesia and mild conscious sedation. This case suggests local ophthalmologic effect of topical pharyngeal anesthesia that was not previously reported.
Short Pulse Laser Interaction With Solids

Intense, short duration laser pulses can be focused onto solids to produce high temperature, non-equilibrium, solid density plasmas. Electrons are heated within an optical skin depth in the target with little vaporization of the target during the laser pulse.
Low-temperature induction of starch degradation in roots of a biennial weed.

Abstract Decreasing temperatures were observed to induce starch degradation in roots of mullein, a biennial weedy species. Virtually no starch remains in the roots when the acclimation period of decreasing temperatures is followed by an extended period of exposure to 4 °C. The breakdown of starch which is presumed to occur in late autumn under field conditions may provide cryoprotective chemicals for the overwintering rosette. Such chemicals might also serve as an energy source for the bolting process which occurs during the following spring or early summer.
Companion animals in Indiana elementary schools

AbstractThis descriptive study examines data on the presence of pets in elementary classrooms in a sample of rural, suburban, and urban elementary school classrooms in Indiana, and suggests a rich area for researchers interested in human–animal interactions in school settings. A convenience sample of rural, suburban, and urban teachers was compiled from the state department of education's database, and surveys were sent to 2,149 teachers in 115 schools. More than 25% of the responding teachers' classrooms contained a variety of animals, mostly small vertebrates. Teachers used animals to provide enjoyment and hands-on educational experiences for students. This article extends similar classroom research by Zasloff, Hart and DeArmond (1999). The educational value of classroom animals is not often appreciated or studied, and the results of this study suggest this is a productive area for interdisciplinary research.
The prerequisites for strategic behaviour in bluegill sunfish, Lepomis macrochirus

Abstract Game theory often assumes that animals employ ‘strategies’ in which future behaviour is based on past interactions with known individuals. The question of whether animals have the cognitive ability to employ such strategies has seldom been examined empirically. In a laboratory experiment, bluegill sunfish, Lepomis macrochirus, were allowed to forage in pairwise association with five conspecifics to address two questions. (1) Do bluegill sunfish prefer to associate with individuals with whom they have foraged more successfully? (2) Do bluegill sunfish prefer familiar associates over unfamiliar associates? Results indicated that bluegill sunfish distinguish between known associates, and base their preference for such associates on relative success in prior foraging bouts. In addition, they are aware of a group member/non-group member dichotomy and choose to associate with known over unknown conspecifics.
Permittivity of ice and water at millimeter wavelengths

Measurements of reflectivity of water and ice at 100 GHz, 140 GHz, and 180 GHz are reported. Measurements on water covered the temperature range 0 C to 50 C. No anomalies in the dielectric properties of water due to the presence of either salts or organic matter were found. The reflectivity of water and its temperature dependence are consistent with recent dielectric property models derived from data at other wavelengths. The index of refraction of fresh ice is constant at 1.78 throughout this regions.
Differential Transcriptional Regulation of Aggregatibacter actinomycetemcomitans lsrACDBFG and lsrRK Operons by Integration Host Factor Protein

We previously showed that the Aggregatibacter actinomycetemcomitans lsrACDBFG and lsrRK operons are regulated by LsrR and cyclic AMP receptor protein (CRP) and that proper regulation of the lsr locus is required for optimal biofilm growth by A. actinomycetemcomitans. Here, we identified sequences that reside immediately upstream from both the lsrA and lsrR start codons that closely resemble the consensus recognition sequence of Escherichia coli integration host factor (IHF) protein. A. actinomycetemcomitans IHFα and IHFβ were expressed and purified as hexahistidine fusion proteins, and using electrophoretic mobility shift assays (EMSAs), the IHFα-IHFβ protein complex was shown to bind to probes containing the putative IHF recognition sequences. In addition, single-copy chromosomal insertions of lsrR promoter-lacZ and lsrA promoter-lacZ transcriptional fusions in wild-type A. actinomycetemcomitans and ΔihfA and ΔihfB mutant strains showed that IHF differentially regulates the lsr locus and functions as a negative regulator of lsrRK and a positive regulator of lsrACDBFG. Deletion of ihfA or ihfB also reduced biofilm formation and altered biofilm architecture relative to the wild-type strain, and these phenotypes were partially complemented by a plasmid-borne copy of ihfA or ihfB. Finally, using 5' rapid amplification of cDNA ends (RACE), two transcriptional start sites (TSSs) and two putative promoters were identified for lsrRK and three TSSs and putative promoters were identified for lsrACDBFG. The function of the two lsrRK promoters and the positive regulatory role of IHF in regulating lsrACDBFG expression were confirmed with a series of lacZ transcriptional fusion constructs. Together, our results highlight the complex transcriptional regulation of the lsrACDBFG and lsrRK operons and suggest that multiple promoters and the architecture of the lsrACDBFG-lsrRK intergenic region may control the expression of these operons.
Habituation of the GSR and of breathing disturbances in the cat

The habituation of the GSR and breathing disturbances elicited by a compound stimulus was observed in six cats over 12 daily sessions. Some recovery of response occurred between sessions. Presentation of two spaced shocks failed to produce disinhibition. The two responses were relatively independent.
Tolerance to Heterologous Erythrocytes

Injection of a water-soluble nonantigenic fraction obtained from lysed sheep red blood cells virtually abolishes the subsequent immune response to the red cells. The suppression is systemic and appears to be serum mediated.
Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr1+, Zr2+, and Zr3+ as non-equilibrium oxidation states, in addition to Zr4+ in the stoichiometric ZrO2. This finding resolves the long-debated question of whether it is possible to form any valence states between Zr0 and Zr4+ at the metal-oxide interface. The presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr.
Simulation of the estimation of ageing bias inside an integrated assessment of canary rockfish using age estimates from a bomb radiocarbon study

The stock of canary rockfish off the west coast of the continental US is currently assessed using an integrated statistical catch-at-age model. The functional form of an ageing bias detected in production ageing (large numbers of ages read for use in stock assessment) from a bomb radiocarbon study with small sample size (n = 16) was estimated externally and used to adjust the age data in the most recent stock assessment. Using simulation methods, the present study evaluated whether integrating the estimation of the ageing bias inside the assessment model would (1) influence the uncertainty in assessment results and (2) improve our ability to differentiate between competing functional forms (linear, linear with intercept and jointed) for specifying the ageing bias. Internal estimation of the ageing bias relationship increased the approximate 95% confidence interval width about the spawning biomass estimate by 1–10% depending on the functional form assumed. The assessment model was not able to reliably distinguish between all competing functional forms of the ageing bias tested, even with increased radiocarbon sample sizes. However, significant under-ageing at the youngest ages was found to be inconsistent with other sources of data in the assessment model. The question of ageing bias form remains important because it had moderate effects on estimates of spawning biomass and assessment model uncertainty.
Gel filtration of vitamin B12-binding materials from human gastric juice and gastric mucosa

Abstract 1. 1. In the course of experiments to isolate human intrinsic factor, its behavior on gel filtration through Sephadex G-100 at pH 7.3 was compared with that of the vitamin B12-intrinsic factor complex from human gastric juice and gastric mucosa, and with bovine serum albumin and human hemoglobin. 2. 2. The vitamin B12-binding materials of neutralized gastric juice showed the same elution pattern whether the vitamin B12 was added before or after gel filtration. This pattern was the same as that obtained from gastric mucosal homogenates with added vitamin B12. Two peaks of vitamin B12-binding material were found, a small initial one comprising some 15–20% of the total vitamin B12-binding activity of the specimen and a second peak representing 80–85% of the activity. 3. 3. The first peak gave no reaction in a specific radioimmunodiffusion assay for intrinsic factor. 4. 4. The second peak gave a strong reaction for intrinsic factor in the radioimmunodiffusion assay and its vitamin B12-binding activity could be completely abolished by specific antibody, indicating that it was composed entirely or almost entirely of intrinsic factor. 5. 5. The intrinsic factor showed a distribution coefficient of 0.198 in this column, the same as bovine serum albumin. Since deviation from sphericity of the intrinsic factor and the presence of carbohydrate in the molecule would produce an overestimation of the molecular weight, it is probable that the molecular weight of the intrinsic factor has an upper limit of 65000–70000. There was no evidence for the presence of any intrinsic factor material of higher molecular weight than this either in the gastric mucosa or neutralized gastric juice. 6. 6. Addition of vitamin B12 to the intrinsice factor did not alter its gel filtration behavior indicating that the binding of vitamin B12 did not produce any gross changes in the molecule. 7. 7. The gel filtration with Sephadex G-100 gave a 10-fold purification of the intrinsic factor from gastric juice which was obtained in a yield of 80%.
Aggregation and Alkylation of the Cesium Enolate of 2-p-Biphenylylcyclohexanone1

The cesium enolate of 2-biphenylylcyclohexanone (CsBPCH), generated by deprotonation of 2-biphenylylcyclohexanone with diphenylmethylcesium, is shown to be a mixture of monomer and dimer in THF, wi...
Democracy in the 21st century: can we be optimistic?

The prospects for the spread of democracy around the world in the 21st century appear to be bright, but there are also important reasons for pessimism. One is that politicians and constitution-writers in the democracies are not aware of, or choose to ignore, compelling social science evidence concerning the superiority of parliamentary systems of government and proportional representation (in contrast to presidential government and majoritarian electoral systems). The older democracies are not in danger of failing, but they are losing much of their democratic vitality, as seen in the decline of people's interest in politics, decreasing voter participation, and the serious weakening of political parties. For these problems, too, parliamentarism and proportional representation are at least partial remedies, but stronger measures (such as compulsory voting) also deserve to be considered seriously
Interplay of Acute and Persistent Infections Caused by Venezuelan Equine Encephalitis Virus Encoding Mutated Capsid Protein

Venezuelan equine encephalitis virus (VEEV) is a significant human and animal pathogen. The highlight of VEEV replication in vitro, in cells of vertebrate origin, is the rapid development of cytopathic effect (CPE), which is strongly dependent upon the expression of viral capsid protein. Besides being an integral part of virions, the latter protein is capable of (i) binding both the nuclear import and nuclear export receptors, (ii) accumulating in the nuclear pore complexes, (iii) inhibiting nucleocytoplasmic trafficking, and (iv) inhibiting transcription of cellular ribosomal and messenger RNAs. Using our knowledge of the mechanism of VEEV capsid protein function in these processes, we designed VEEV variants containing combinations of mutations in the capsid-coding sequences. These mutations made VEEV dramatically less cytopathic but had no effect on infectious virus production. In cell lines that have defects in type I interferon (IFN) signaling, the capsid mutants demonstrated very efficient persistent replication. In other cells, which have no defects in IFN production or signaling, the same mutants were capable of inducing a long-term antiviral state, downregulating virus replication to an almost undetectable level. However, ultimately, these cells also developed a persistent infection, characterized by continuous virus replication and beta IFN (IFN-beta) release. The results of this study demonstrate that the long-term cellular antiviral state is determined by the synergistic effects of type I IFN signaling and the antiviral reaction induced by replicating viral RNA and/or the expression of VEEV-specific proteins. The designed mutants represent an important model for studying the mechanisms of cell interference with VEEV replication and development of persistent infection.
Schubmehl-Prein essay competition: "What are the Potential Social and Ethical Implications of the $100 Laptop?"

The 2009 competition was the fifth year of the Schubmehl-Prein contest for the Best Essay on Social Impact of Computing. The competition is open to high school juniors each year, with a submission deadline at the end of May. The essay topic varies each year, with the 2009 topic being, "What are the potential social and ethical implications of the $100 laptop?" The 2009 competition attracted a number of essays that strongly engaged with the topic. The 2009 First Place winner is Katherine Heit (Saint Thomas Aquinas High School, Kansas), the Second Place winner is Danielle Harris (Mayfield Senior School, California), and the Third Place winner is David Purington (Damien High School, California). In addition, this year, for the first time, two Honorable Mention winners were also selected: Bryan Dongre (Brookfield Central High School, Wisconsin) and Erica Smith (St. Agnes Academy, Texas). Revised versions of the First, Second and Third Place essays appear in this issue of Computers and Society. Congratulations to all of this year's winners. Thanks to all of the students who prepared and submitted an entry to the competition. And thanks as well to all of the teachers and school counselors who worked with all of the students.
Effects of profound anemia on brain tissue oxygen tension, carbon dioxide tension, and pH in rabbits

This study sought to determine the maximum tolerable limit of anemia for the brain during halothane anesthesia. Using a multiparameter sensor, we continuously monitored brain tissue oxygen tension (PO2), carbon dioxide tension (PCO2), and pH during profound hemodilution and subsequent transfusion. Twelve New Zealand White rabbits were anesthetized, intubated, and mechanically ventilated at a fraction of inspired oxygen (FiO2) of 21% to produce an arterial carbon dioxide tension (PaCO2) of 35 to 40 mm Hg. The femoral artery was cannulated to continuously monitor arterial blood pressure and to intermittently measure arterial blood gases. The electroencephalogram (EEG) was recorded throughout the course of the study. A fiberoptic sensor was inserted into the brain for the continuous measurement of brain PO2, PCO2, pH, and temperature. Cerebral blood flow (CBF) was measured by the hydrogen clearance method. Severe anemia was induced by repeatedly withdrawing 50-mL aliquots of blood and infusing an equal volume of 6% hetastarch. This procedure was performed four times for each rabbit. After the forth blood draw and fluid infusion, a total of 60 mL of packed red blood cells were transfused. Upon completion of the hemodilution, the hemoglobin concentration was 2.4 +/- 0.3 g/dL (mean +/- SEM). Brain tissue PO2 decreased from 27 +/- 3 mm Hg to a minimum of 12 +/- 2 mm Hg. Brain tissue pH also decreased from 7.22 +/- 0.03 to 7.12 +/- 0.05 and returned to the baseline value with transfusion. Brain PCO2 did not change significantly during the experiment. Cerebral blood flow increased from 37 +/- 3 to 66 +/- 15 mL x 100 g(-1) x min(-1) during hemodilution and returned to baseline after infusion of red blood cells. There was some loss of EEG amplitude and the calculated cerebral metabolic rate (CMRO2) decreased from 4.3 +/- 0.6 to 1.9 +/- 0.3 mL x 100 g(-1) x min(-1) at the most profound level of anemia. This is the first report of which the authors are aware of continuous monitoring of brain tissue pH, PCO2, and PO2 during profound hemodilution and transfusion. Hemodilution results in a decrease in brain tissue PO2. Increases in CBF and oxygen extraction can only partially compensate for the decreased oxygen carrying capacity of the blood. Decreases in brain tissue PO2, pH, CMRO2, and a loss of EEG amplitude suggest that the maximum tolerable limit of hemodilution was achieved in this study.
International standardization of technical products

Abstract The literature on product adaptation in international markets has emphasized cultural, social, and political influences that necessitate a change in the product configuration. In contrast, this article's focus is on the international technical environment. A case study is used to illustrate international standardization of technical products and its management implications.
Sexually transmitted disease prevention campaigns in the 21st century: new frontiers in social media.

The assessment of the Get Yourself Tested (GYT) campaign presented by Friedman et al., in this issue of Sexually Transmitted Diseases, is important both for identifying the opportunities to use and integrate 21st century social media and mobile health (mHealth) tools into sexually transmitted disease (STD) prevention initiatives and for identifying the key areas where our field can improve to maximize the use of these tools. The GYT campaign offers an important perspective on 3 elements of health communication campaigns in the digital era including: (a) the use of multiple and diverse social media tools, (b) the role of social science theory, and (c) the integration of multiple and big data sources for evaluation. I will discuss each of these in turn.
Periodic increases in elongation rate precede increases in cytosolic Ca2+ during pollen tube growth.

Pollen tubes grown in vitro require an intracellular tip-high gradient of Ca 2+ in order to elongate. Moreover, after about 2 h in vitro both the tip Ca 2+ and the elongation rate of lily tubes begin to oscillate regularly with large amplitudes. This raises the question of the phase relation between these two oscillations. Previous studies lacked the temporal resolution to accurately establish this relationship. We have studied these oscillations with a newly developed, high temporal resolution system and the complementary use of both luminescent and fluorescent calcium reporters. We hereby show that the periodic increases in elongation rate during oscillatory growth of Lilium longiflorum pollen tubes clearly precede those in subtip calcium and do so by 4.1 ± 0.2 s out of average periods of 38.7 ± 1.8 s. Also, by collecting images of the light output of aequorin, we find that the magnitude of the [Ca 2+ ] at the tip oscillates between 3 and 10 μM, which is considerably greater than that reported by fluorescent indicators. We propose an explanatory model that features cyclic growth and secretion in which growth oscillations give rise to secretion that is essential for the subsequent growth oscillation. We also critically compile data on L. longiflorum stylar growth rates, which show little variation from in vitro rates of pollen tubes grown in optimal medium.
Synthesis and enzymatic cleavage of dual-ligand quantum dots

Site directed therapy promises to minimize treatment-limiting systemic effects associated with cytotoxic agents that have no specificity for pathologic tissues. One general strategy is to target cell surface receptors uniquely presented on particular tissues. Highly specific in vivo targeting of an emerging neoplasm through a single molecular recognition mechanism has not generally been successful. Nonspecific binding and specific binding to non-target cells compromise the therapeutic index of small molecule, ubiquitous cancer targeting ligands. In this work, we have designed and fabricated a nanoparticle (NP) construct that could potentially overcome the current limitations of targeted in vivo delivery. Quantum dots (QDs) were functionalized with a poly(ethylene glycol) (PEG) modified to enable specific cleavage by matrix metalloprotease-7 (MMP-7). The QDs were further functionalized with folic acid, a ligand for a cell surface receptor that is overexpressed in many tumors, but also expressed in some normal tissues. The nanomolecular construct is designed so that the PEG initially conceals the folate ligand and construct binding to cells is inhibited. MMP-7 activated peptide cleavage and subsequent unmasking of the folate ligand occurs only near tumor tissue, resulting in a proximity activated (PA) targeting system. QDs functionalized with both the MMP-7 cleavable substrate and folic acid were successfully synthesized and characterized. The proteolytic capability of the dual ligand QD construct was quantitatively assessed by fluorometric analysis and compared to a QD construct functionalized with only the PA ligand. The dual ligand PA nanoparticles studied here exhibit significant susceptibility to cleavage by MMP-7 at physiologically relevant conditions. The capacity to autonomously convert a biopassivated nanostructure to a tissue-specific targeted delivery agent in vivo represents a paradigm change for site-directed therapies.
Substrate specificity of caeruloplasmin indoles and indole isosteres.

Abstract Several indoles and indole isosteres have been examined as potential substrates for the oxidative enzyme caeruloplasmin. Amongst the indoles the presence of a hydroxy group on the aromatic ring of the indole nucleus is a necessary requirement for substrate activity; this hydroxy group may be at position 4, 5 or 6 of the indole nucleus. An aminoalkyi, or substituted aminoalkyi, chain attached to position 3 of the indole ring is necessary for high substrate activity; the distance separating the basic group of the side chain from the indole ring does not appear to be critical. Studies on indole isosteres (analogues of 5-hydroxytryptamme) have clearly shown that only the presence of an imino group, at position 1 of the bicyclic system, is compatible with substrate activity.
Epothilone C Macrolactonization and Hydrolysis Are Catalyzed by the Isolated Thioesterase Domain of Epothilone Polyketide Synthase

Epothilone C is produced by the combined action of one nonribosomal peptide synthetase (NRPS) and nine polyketide synthase (PKS) modules in a multienzyme system. The final step in the biosynthesis is the thioesterase (TE)-catalyzed cyclorelease of epothilone from the EpoF protein. It has been unclear whether isolated PKS TE domains could exhibit macrolactonization activity. Here we demonstrate that the excised epothilone TE domain can catalyze the efficient cyclization of the N-acetylcysteamine thioester of seco-epothilone C to generate epothilone C (kcat/KM = 0.41 ± 0.03 min-1 mM-1). The TE domain also catalyzes the hydrolysis of both the N-acetylcysteamine thioester of seco-epothilone C (kcat = 0.087 ± 0.005 min-1, KM = 291 ± 53 μM) and that of the epothilone C (kcat = 0.67 ± 0.01 min-1, KM = 117 ± 5 μM) to form seco-epothilone C.
Headache and temporomandibular disorders: evidence for diagnostic and behavioural overlap

To assess the diagnostic and behavioural overlap of headache patients with temporomandibular disorders (TMD), individuals recruited from the general population with self-described headaches were compared with non-headache controls. The examination and diagnostic procedures in the Research Diagnostic Criteria (RDC) for TMD were applied to both sets of subjects by a blinded examiner. Following their examination, subjects used experience sampling methods to obtain data on pain, tooth contact, masticatory muscle tension, emotional states and stress. Results showed that a significantly higher proportion of the headache patients received an RDC/TMD diagnosis of myofascial pain than non-headache controls. Headache patients also reported significantly more frequent and intense tooth contact, more masticatory muscle tension, more stress and more pain in the face/head and other parts of the body than non-headache controls. These results are similar to those reported for TMD patients and they suggest that headache patients and TMD patients overlap considerably in diagnosis and oral parafunctional behaviours.
What Healthcare Leaders Can Learn from Research on Dark Networks

In healthcare, if there is a problem that involves coordination of care, someone will surely suggest that a network is the solution to the lack of coordination. This in fact is the network value proposition. Because of this, we have tended to think of networks as the highest stage of organizing to solve collective problems like a strategy to better serve the needs of the mentally ill in a province or state. This article asserts that the assumption that networks are superior to organizations or markets as a means of coordination is wrong. If a problem can be dealt with effectively in a market or a single organization, healthcare leaders should do it, as it is much easier. Both organizations and markets have high-powered incentives like prices or commands to coordinate the activity. Networks should be reserved for problems that do not fit neatly into a market or organization, and because reciprocity based on trust is the adhesive that holds a network together, there must be adequate time for trust to emerge to facilitate the effective coordination of network activity. Leaders should choose networks when it is clear that markets and hierarchical organizations have failed and where there are problems that are complex and multifaceted and beyond the ability of a single organization or the price system to coordinate them effectively.
Diode-pumped monolithic Nd:YLF 1.053-μm minilaser and its application to injection seeding

The construction and operation of a diode-pumped Nd:YLF monolithic mini-laser operating at 1.053 μm is described along with its application of injection seeding a CW flashlamp pumped Nd:YLF Q-switched oscillator to produce single frequency pulses. Alignment of the mini-laser axis to the "c" axis of the Nd:YLF crystal allows lasing at 1.053 μm in a monolithic configuration. The Q-switched oscillator when seeded produces single frequency pulses 90% of the time.
A new method for calculating correction factors for near-field gain measurements

A new method is presented for calculating near-field antenna gain correction factors directly from measured far-field pattern data by using a spherical wave expansion of the pattern. This eliminates the need for any assumptions regarding antenna aperture field distributions. The only significant assumption in the new method is to neglect multiple scattering between the antennas. The method is applied to the case of a horn antenna. Calculated results are compared to direct measured results, demonstrating agreement to within 0.03 dB. The method is also compared to the method of Chu and Semplak, with similar agreement. The sensitivity of the results to truncation error and noise in the data is also investigated and contrasted to sensitivity of prior methods to errors in the assumed field distribution.
THE SOCIAL SECURITY PAYROLL TAX: SOME ALTERNATIVES FOR REFORM

IN FISCAL YEAR 1975 the social security payroll tax will amount to over $73 billion; this represents a six-fold increase just since fiscal 1960. In addition, its absolute growth has been accompanied by the growing importance of this tax as a federal revenue source. In 1960 the payroll tax accounted for only 12 per cent of total federal revenue. However, its share has doubled since then and in 1975 the payroll tax for social security will amount to about 25 per cent of total federal receipts. In contrast, the individual income tax will raise 44 per cent and the corporation income tax only 16 per cent of total federal revenue in fiscal 1975. Since the payroll tax is regressive and particularly burdensome for low-income workers, there has been growing interest in ways to make the tax more equitable in recent years. In this paper, I briefly review the evolution of social security and examine the payroll tax used to finance it. Next, I examine the aggregate and distributional effect of a specific plan to provide low-income tax relief through the existing payroll tax structure. This is then contrasted with providing relief through the use of general revenues or through total integration of the individual income and payroll taxes.
Absence Of Precore Stop Mutant In Chronic Dual (B And C) And Triple (B, C, And D) Hepatitis Virus Infection

Sequences of hepatitis B virus (HBV) precore regions from 7 patients with HBV and hepatitis C virus (HCV) dual infection and 2 with HBV, HCV, and hepatitis D virus (HDV) triple infection were analyzed. Two patients, 1 with only acute HBV infection and 1 with only chronic HBV infection, were also included for comparison. All patients had antibodies against HBV e antigen (anti-HBe) except 1 with chronic hepatitis B and C. No precore stop mutation at codon 28 (TGG to TAG mutation) was found in 21 cloned sequences from the 7 patients with HBV and HCV infection, nor in 11 cloned sequences from 2 patients with HBV, HCV, and HDV infection. However, mutations in other positions of the precore region were observed in 2 patients with hepatitis B and C. In both cases, precore sequences with mutations in different positions were obtained from the same serum sample. No mutations were observed in other positions of the precore region in the 2 patients with hepatitis B, C, and D. The presence of anti-HBe in these patients was probably due to the low level of HBV replication and not to the presence of the precore stop mutant.
Breeding density affects point-count accuracy in Missouri forest birds

Abstract We compared 50-m fixed-radius point-count detections for four bird species with density data from spot-mapping in order to evaluate the relationship between monitoring methodologies. We conducted this study in five Missouri oak-hickory forest study sites over eight years. There were significant positive correlations between monitoring methods, but the strength of these relationships varied for Acadian Flycatchers (Empidonax virescens), Ovenbirds (Seiurus aurocapilla), Worm-eating Warblers (Helmitheros vermivorus), and Wood Thrushes (Hylocichla mustelina). There was significant bias associated with the point-count detections for Acadian Flycatchers, Worm-eating Warblers, and Wood Thrushes. The direction and degree of bias varied; for example, Acadian Flycatchers and Worm-eating Warblers were on average significantly overestimated by point counts, whereas the Wood Thrush was significantly underestimated and Ovenbirds were slightly underestimated. The magnitude and direction of the bias error varied...