cssi/SciSciGPT-SciSciNet huggingface dataset:
Microglia induce neurogenic protein expression in primary cortical cells by stimulating PI3K/AKT intracellular signaling in vitro

Emerging evidence suggests that microglia can support neurogenesis. Little is known about the mechanisms by which microglia regulate the cortical environment and stimulate cortical neurogenesis. We used an in vitro co-culture model system to investigate the hypothesis that microglia respond to soluble signals from cortical cells, particularly following mechanical injury, to alter the cortical environment and promote cortical cell proliferation, differentiation, and survival. Analyses of cortical cell proliferation, cell death, neurogenic protein expression, and intracellular signaling were performed on uninjured and injured cortical cells in co-culture with microglial cell lines. Microglia soluble cues enhanced cortical cell viability and proliferation cortical cells. Co-culture of injured cortical cells with microglia significantly reduced cell death of cortical cells. Microglial co-culture significantly increased Nestin + and α-internexin + cortical cells. Multiplex ELISA and RT-PCR showed decreased pro-inflammatory cytokine production by microglia co-cultured with injured cortical cells. Inhibition of AKT phosphorylation in cortical cells blocked microglial-enhanced cortical cell viability and expression of neurogenic markers in vitro. This in vitro model system allows for assessment of the effect of microglial-derived soluble signals on cortical cell viability, proliferation, and stages of differentiation during homeostasis or following mechanical injury. These data suggest that microglia cells can downregulate inflammatory cytokine production following activation by mechanical injury to enhance proliferation of new cells capable of neurogenesis via activation of AKT intracellular signaling. Increasing our understanding of the mechanisms that drive microglial-enhanced cortical neurogenesis during homeostasis and following injury in vitro will provide useful information for future primary cell and in vivo studies.
Technical considerations for genicular nerve radiofrequency ablation: optimizing outcomes

Genicular nerve radiofrequency ablation has emerged as a treatment option for patients with painful knee osteoarthritis who have failed conservative management but who may not qualify or wish to avoid a surgical procedure. Radiofrequency ablation techniques targeting the genicular nerves have evolved as our understanding of the anatomy of the anterior knee joint capsule has become more defined. The article aims to review the basic anatomy of the anterior knee joint and both the traditional and revised approaches to nerve ablation.
The Legacy of Exploitation in Intercountry Adoptions from Ethiopia: “We Were under the Impression That Her Birth Parents Had Died”

Ethiopia legally banned intercountry adoption in 2018 following reports of corruption, illegal practices, and child trafficking. While the intercountry adoption program is now closed, the enduring ...
Abstract P686: Ischemic Stroke in Reversible Cerebral Vasoconstriction Syndrome

Introduction: Ischemic stroke is the cause for major morbidity and mortality in reversible cerebral vasoconstriction syndrome (RCVS). While there is evidence to suggest that ischemic stroke in RCVS...
Historical and cultural perspectives of oak trees in the American landscape

Over the course of history, oak trees have played a significant role in the natural landscape and built environment. While providing essential resources that sustain wildlife and even humans, they ...
Impact of Sustainability Consciousness on Slow Fashion Behavior

Based on the review of existing literature, we developed two primary research questions in this study: 1) what is the domain of slow fashion behavior? and 2)is the slow fashion behavior related to sustainability consciousness? To answer these questions, the present study aimed to 1) investigate slow fashion behaviors and develop a scale of slow fashion behavior and 2) examine the influence of sustainability consciousness, through the lenses of sustainability knowingness, attitudes and behaviors, on consumers’ slow fashion behaviors.
COVID-19 Serology Control Panel Using the Dried Tube Specimen Method

We used the dried tube specimen (DTS) procedure to develop the COVID-19 Serology Control Panel ( CSCP). The CSCP contains five well-characterized SARS-CoV-2 pooled plasma samples made available for labs around the world to compare test kits, use for external quality assurance, harmonize laboratory testing, and train laboratory workers.
Viral long terminal repeat substrate binding characteristics of the human immunodeficiency virus type 1 integrase.

Abstract A DNA binding assay was developed for the human immunodeficiency virus type 1 (HIV-1) integrase. The assay was capable of defining discrete complexes between the enzyme and the viral long terminal repeat (LTR) substrate. DNA binding reflected the sequence requirements previously demonstrated for the enzyme's 3'-end processing activity. Binding exhibited a nonlinear dependence on integrase concentration, suggesting that the enzyme functions as a multimer. The oligomeric state was investigated by UV-photo-cross-linking of integrase-LTR oligonucleotide complexes using DNA substrates substituted with 5-bromo-2'-deoxycytidine within the integrase recognition sequence. In the absence of divalent cation, integrase cross-linked to the LTR oligonucleotide as a single species whose mobility by SDS-polyacrylamide gel electrophoresis was consistent with the formation of tetramers. Using these techniques, analysis of the binding properties of integrase mutants demonstrated that the catalytic and sequence-specific DNA binding activities of the enzyme are distinct, involving residues within the conserved "DD(35)E" and zinc finger motifs, respectively.
Fluorescence resonance energy transfer microscopy: theory and instrumentation.

Publisher Summary This chapter outlines the basic principles of fluorescence resonance energy transfer (FRET), focusing on both steady-state and time-resolved methodologies. The focus is also on developing different kinds of FRET microscopes, emphasizing the specific pieces of equipment that are required for making the quantitative or qualitative determinations of molecular associations. Coupled with the advent of the development of new fluorescent probes such as the green fluorescent protein and other genetically engineered reporters, the future of this technology is likely to reveal molecular associations both within cells and on cell surfaces that were previously detected only using nonmicroscopic methods.
Campaign 2016—The First Words and Their Audiences

When do citizens begin to attend to election campaigns for the presidency? The timing is changing as the infrastructure of communication changes. What could be said in the days when television was dominant is no longer a full answer given the emergence of new media as a vehicle for political communication. This report addresses the question of when by examining the messages posted to Twitter after Jeb Bush said he would consider running for the nomination of the Republican party. What was the reaction in those first two weeks of the campaign?
Campaigns and the Mitigation of Framing Effects on Voting Behavior: A Natural and Field Experiment

There is a widely held belief that the way a ballot proposition title is framed (the way the issue is presented) has an effect on its eventual success or failure on Election Day. Prior to California’s 2010 General Election, the ballot language for two propositions was disputed and challenged in court. For both Proposition 22, intended to change the allocation of state and local tax revenues, and Proposition 23, intended to overturn California’s landmark global-warming law, Fresno County failed to make the court ordered changes. The election proceeded with the unchanged ballot language in Fresno County and the newly adjusted ballot language throughout the rest of the state. This paper takes advantage of this natural experiment to evaluate the potency of framing effects in direct democracy elections, as well as, the role that campaigns (high salience versus low salience) can play in limiting those effects. As a further test, survey data using identical language collected in an area where neither issue was of high salience is used as a comparison. This additional test serves as a mechanism to isolate any potential framing effect of campaigns. We conclude that the way a ballot measure is framed has an impact on its Election Day success so long as it is a relatively low-salience measure. For initiatives with vigorous campaign activity, such as Proposition 23, framing effects are less effective and not statistically significant in this instance.
Synthesis and properties of highly fluorescent indolizino[3,4,5-ab]isoindoles.

We report here the synthesis, X-ray structures, optical and electrochemical properties, fabrication of light-emitting devices, and density functional calculations for indolizino[3,4,5-ab]isoindole (INI) derivatives. Strongly luminescent heterocycles based on the INI unit were synthesized by 1,3-dipolar cycloaddition reactions between pyrido[2,1-a]isoindole (PIS) and acetylene or ethylene derivatives. They are indolizino[3,4,5-ab]isoindoles 2−9 and 14−15, benzo[1‘,2‘-1,2]indolizino[3,4,5-ab]isoindoles 10, pyridazino[4‘,5‘:1,2]indolizino[3,4,5-ab]isoindoles 12−13, and 2,3-hydropyridazino[4‘,5‘:1,2]indolizino[3,4,5-ab]isoindole-1,4-dione 11. The relative luminescence quantum yield can be as high as 90%. Their reduction and oxidation potentials and high luminescence can make these heterocycles possible alternatives to tris(8-hydroxyquinolinato)aluminum (Alq3). The brightness of the light-emitting device reached as high as 104 cd/m2 and indolizino[3,4,5-ab]isoindole 3 emits beautifully blue light. The X-ray cr...
Probing the influence of local coordination environment on the properties of Fe-type nitrile hydratase model complexes.

A series of four structurally related cis-dithiolate-ligated Fe(III) complexes, [FeIII(DITpy)2]Cl (1), [FeIII(DITIm)2]Cl (2), [FeIII(ADIT)2]Cl (3), and [FeIII(AMIT)2]Cl (4), are described. The structural characterization of 3 as well as the spectroscopic properties of 3 and 4 has been previously reported. Crystal data for 1, 2, and 4 are as follows: 1·3H2O crystallizes in the orthorhombic space group Pca21 with a = 19.800(4) A, b = 18.450(4) A, c = 14.800(3) A, and Z = 8. 2·1/2EtOH·1/2H2O crystallizes in the monoclinic space group Cc with a = 24.792(4) A, b = 14.364(3) A, c = 17.527(3) A, β = 124.91(2)°, and Z = 8. 4 crystallizes in the triclinic space group P1 with a = 8.0152(6) A, b = 10.0221(8) A, c = 11.8384(10) A, α = 73.460(3)°, β = 71.451(5) °, γ = 72.856(4)°, and Z = 2. Complexes 1−4 share a common S2N4 coordination environment that consists of two cis-thiolates, two trans-imines, and two cis-terminal nitrogen donors: Nterm = pyridine (1), imidazole (2), and primary amine (3 and 4). The crystal...
Valuing climate protection through willingness to pay for biomass ethanol

Abstract This study uses a multi-part, split-sample contingent valuation method (CVM) and fair share (FS) survey to better understand the public's valuation of mitigating global climate change through its willingness to pay for biomass or “cellulosic” ethanol. In addition to a basic CVM question, a related scenario was developed that asked half of the survey respondents to state their fair share cost to lessen a potential food shortage in the next decade, also through the expanded use of cellulosic ethanol. Three alternative biomass feedstocks were assessed: farming residues, forestry residues and paper mill wastes, and municipal solid wastes. Overall a slightly larger proportion of respondents were WTP extra for cellulosic ethanol in the basic CVM scenario than in the FS scenario, though no significant differences were found in the WTP for the different feedstocks. Bid curve lognormal regression results for the two models were similar, supporting the idea that asking a FS rather than a conventional WTP question may be justifiable in some circumstances, such as in cases of a national emergency.
Computed tomography—a reliable diagnostic modality in pulmonary asbestosis

Forty-six individuals with documented asbestos exposure were studied by computed tomography as part of their initial evaluation. CT sections were compared to standard chest radiographs and pulmonary function tests. The results showed computed tomography to be able to detect early signs of asbestosis in patients with inconclusive conventional radiographs or intact pulmonary function tests, the same as to demonstrate extensive pulmonary pathology in long-standing cases.
Serially heterotransplanted human prostate tumours as an experimental model

* Introduction * Serially heterotransplanted human tumours in immunosuppressed mice: similarity to the tumour of origin - Cytological and histological analysis - Karyotype - Marker expression - Other PC markers - Tumour cell proliferation and frequency of mitosis - Vasculature - Stromal compartment - Heterotransplant hormone dependency - Androgen dependent - Partially androgen dependent - Androgen independent - Metastases * Conclusions Preclinical research on prostate cancer (PC) therapies uses several models to represent the human disease accurately. A common model uses patient prostate tumour biopsies to develop a cell line by serially passaging and subsequent implantation, in immunodeficient mice. An alternative model is direct implantation of patient prostate tumour biopsies into immunodeficient mice, followed by serial passage in vivo. The purpose of this review is to compile data from the more than 30 years of human PC serial heterotransplantation research. Serially heterotransplanted tumours are characterized by evaluating the histopathology of the resulting heterotransplants, including cellular differentiation, karyotype, marker expression, hormone sensitivity, cellular proliferation, metastatic potential and stromal and vascular components. These data are compared with the initial patient tumour specimen and, depending on available information, the patient's clinical outcome was compared with the heterotransplanted tumour. The heterotansplant model is a more accurate preclinical model than older generation serially passaged or genetic models to investigate current and newly developed androgen-deprivation agents, antitumour compounds, anti-angiogenic drugs and positron emission tomography radiotracers, as well as new therapeutic regimens for the treatment of PC.
Blood Lactate During Exercise: Time Course of Training Adaptation in Humans

We determined the time course of adaptation in blood lactate concentration ([La]) during constant-load exercise in response to training. Thirteen healthy subjects (11 males, 2 females) exercised on a cycle ergometer for 30 min/day at a work rate calculated to elicit 70% of pre-training VO2max, 6 days/week for 3 weeks. VO2max and blood [La] during constant-load exercise (training work rate) were determined at the end of each week of training. Training increased VO2max 8.5% (from 48.2 +/- 1.5 ml.kg-1.min-1 pre-training to 52.3 +/- 1.4 ml.kg-1.min-1 post-training, P less than 0.01) and decreased constant-load blood [La] 53% (from 7.8 +/- 0.6 mM pre-training to 3.7 +/- 0.3 mM post-training, P less than 0.01). The training-induced reduction in exercise blood [La] was well fit to an exponential (5.5e (-t/2.2) + 2.3, r = 0.99) with a half-time of 10.7 days. However, this was not the case for the time course of VO2max adaptation. The absolute decrease in blood [La] was correlated with the initial blood [La] (r = 0.88, P less than 0.01), but changes in VO2max were not significantly correlated with initial blood [La] (r = -0.14) nor with changes in blood [La] (r = -0.02). We conclude that (1) blood [La] response to constant-load exercise decreases rapidly and exponentially with training, with a t1/2 of 10.7 days, (2) the magnitude of training adaptation is positively related to the initial blood [La], and (3) the time course and extent of the training-induced adaptations of blood [La] and VO2max appear to be independent of one another.
TβR-II Discriminates the High- and Low-Affinity TGF-β Isoforms via Two Hydrogen-Bonded Ion Pairs†

The TGF-beta isoforms, TGF-beta1, -beta2, and -beta3, share greater than 70% sequence identity and are almost structurally identical. TGF-beta2 differs from the others, however, in that it binds the TGF-beta type II receptor (TbetaR-II) with much lower affinity than either TGF-beta1 or -beta3. It has been previously shown that three conserved interfacial residues, Arg25, Val92, Arg94, in TGF-beta1 and -beta3 are responsible for their high-affinity interaction with TbetaR-II. In this study, the role of each of these residues was examined by creating single, double, and triple substitutions resulting in both TGF-beta3 loss-of-function and TGF-beta2 gain-of-function variants. One-dimensional 1H NMR spectra of the variants confirmed a lack of large structural perturbations. Affinities, kinetics, and thermodynamics for TbetaR-II binding were determined by surface plasmon resonance biosensor analysis. Double substitutions revealed that nearly all of the high-affinity binding is contributed by Arg25 and Arg94. Single site substitutions showed that Arg94 makes the greatest contribution. Substitution of Arg25 and Arg94 with alanine verified the requirement of the arginine guanidinium functional groups for the highly specific hydrogen-bonded ion pairs formed between Arg25 and Arg94 of TGF-beta1 and -beta3, and Glu119 and Asp32 of TbetaR-II. Further kinetic and thermodynamic analyses confirmed that Arg25 and Arg94 are primarily responsible for high-affinity binding and also revealed that noninterfacial longer range effects emanating from the TGF-beta structural framework contribute slightly to TbetaR-II binding. Growth inhibition assays showed that binding changes generally correlate directly with changes in function; however, a role Val92 in this cellular context was uncovered.
Using Sample Survey Weights in Multiple Regression Analyses of Stratified Samples

Abstract The rationale for the use of sample survey weights in a least squares regression analysis is examined with respect to four increasingly general specifications of the population regression model. The appropriateness of the weighted regression estimate depends on which model is chosen. A proposal is made to use the difference between the weighted and unweighted estimates as an aid in choosing the appropriate model and hence the appropriate estimator. When applied to an analysis of the familial and environmental determinants of the educational level attained by a sample of young adults, the methods lead to a revision of the initial additive model in which interaction terms between county unemployment and race, as well as between sex and mother's education, are included.
Resiliency to success: supporting novice urban teachers

Each year, the National Center for Educational Statistics, through the US Department of Education Institute of Educational Sciences, publishes information about the need for millions of new teachers in the USA. Many of these positions are in urban schools. What makes new teachers beat the odds and remain in challenging schools? This study considers existing research on the common characteristics found in resilient urban teachers and extends that research with interview data from 12 novice urban teachers who participated in a mentoring program designed to attract and retain quality urban educators. Using positioning theory, this study highlights seven characteristics common among the participants. Identifying these characteristics and the ways in which the novice teachers used them may help urban district administrators and teacher educators assist novice teachers in positioning themselves to feel successful – and ultimately to be retained – in urban classrooms.
Caste determination and differential diapause within the first brood of Halictus rubicundus in New York (Hymenoptera: Halictidae)

The partially bivoltine, primitively eusocial sweat bee Halictus rubicundus produces two female castes, gynes and non-gynes, in its first brood in New York. Castes in this brood differentiate within the first few days of adult life, with gynes leaving the population to overwinter as early as mid-June (non-gynes further differentiate into replacement queen and worker subcastes, with older females typically dominant). Analysis of possible mechanisms of caste determination reveals that although gynes average significantly larger than non-gynes within the first brood, this appears largely due to a late mean emergence data coupled with an increase in the size of emerging females over the course of brood emergence, rather than a causal relationship. A strong correspondence between male abundance (relative to newly-emerged females) and the pattern of gyne production, along with data from dissections, suggests that females that mate when young become diapausing gynes, while those that do not mate promptly become non-gynes and do not diapause even though many mate later. Although alternatives to this simple mechanism cannot be ruled out entirely, it nevertheless offers profound implications for theoretical and empirical understanding of the evolutionary origins of the worker caste.
The Fortran-P Translator: Towards Automatic Translation of Fortran 77 Programs for Massively Parallel Processors

Massively parallel processors (MPPs) hold the promise of extremely high performance that, if realized, could be used to study problems of unprecedented size and complexity. One of the primary stumbling blocks to this promise has been the lack of tools to translate application codes to MPP form. In this article we show how applications codes written in a subset of Fortran 77, called Fortran-P, can be translated to achieve good performance on several massively parallel machines. This subset can express codes that are self-similar, where the algorithm applied to the global data domain is also applied to each subdomain. We have found many codes that match the Fortran-P programming style and have converted them using our tools. We believe a self-similar coding style will accomplish what a vectorizable style has accomplished for vector machines by allowing the construction of robust, user-friendly, automatic translation systems that increase programmer productivity and generate fast, efficient code for MPPs.
“Quality” education: Exploring the value of bringing the quality approach to the communication classroom

Quality programs, from their early grounding in total quality management to today's modern forms, have become a mainstay in much of American business. Multiple sources suggest that more than half of American businesses have some type of quality program in place. By the late 1980s and early 1990s the quality philosophy had begun permeating the walls of higher education institutions. The primary venue for bringing the quality approach to higher education thus far has been through administrative channels and little has been done to explore its applicability in the classroom. This paper opens with a discussion of the core concepts embedded in the quality approach, considers the potential value of bringing this approach to higher education and specifically to the communication classroom, and concludes by offering suggestions for applications in introductory and upper level communication courses.
Auditory and visual recall of forward and backward digit spans

Increasingly, clinicians obtain data from tests across modalities. Little actual information, however, exists as to normal patterns. An example is auditory and visual recall of digit span. The effects of modality on recall of digit span, sequence, and order were examined with 80 subjects (M age 24.3 yr.). Subjects were given the Wechsler Adult Intelligence Scale-Revised, and a research version of MicroCog: Assessment of Cognitive Functioning. Both contain forward and backward digit spans. Recall for visual presentation was significantly stronger than for auditory presentation of backward digit span. Recall for visual backward digit span was also superior to auditory backward digit span when the sequence of presentation was controlled. The mean number of digits recalled was higher when visual digit span was preceded by auditory digit span.
The Diverse Solar Phase Curves of Distant Icy Bodies. I. Photometric Observations of 18 Trans-Neptunian Objects, 7 Centaurs, and Nereid

We have measured the solar phase curves in B, V, and I for 18 trans-Neptunian objects (TNOs), 7 Centaurs, and Nereid and determined the rotation curves for 10 of these targets. For each body we have made ~100 observations uniformly spread over the entire visible range. We find that all the targets except Nereid have linear phase curves at small phase angles (0.1°-2.0°) with widely varying phase coefficients (0.0-0.4 mag deg-1). At phase angles of 2°-3°, the Centaurs (54598) Bienor and (32532) Thereus have phase curves that flatten. The recently discovered Pluto-scale bodies (2005 FY9, 2003 EL61, and 2003 UB313—now known as 136199 Eris), like Pluto, have neutral colors compared to most TNOs and small phase coefficients (0.1 mag deg-1). Together, these two properties are a likely indication of large TNOs with high-albedo, freshly coated icy surfaces. We find several bodies with significantly wavelength-dependent phase curves. The TNOs (50000) Quaoar, (120348) 2004 TY364, and (47932) 2000 GN171 have unusually high I-band phase coefficients and much lower coefficients in the B and V bands. Their phase coefficients increase in proportion to wavelength by 0.5-0.8 mag deg-1 μm-1 . The phase curves for TNOs with small B-band phase coefficients (<0.1 mag deg-1) have a similar but weaker wavelength dependence. Coherent backscatter is the likely cause for the wavelength dependence for all these bodies. We see no such dependence for the Centaurs, which have visual albedos of ~0.05.
Effects of vibration on grip and push force-recall performance

Abstract Comprehensive assessments of health risks associated with the operation of vibratory tools should include evaluations of hand–tool coupling forces. The use of hand-force instrumentation in field applications can be difficult and expensive. A previous study (McDowell, T.W., Wiker, S.F., Dong, R.G., Welcome, D.E., Schopper, A.W., 2006. Evaluation of psychometric estimates of vibratory hand–tool grip and push forces. International Journal of Industrial Ergonomics 36(2), 119–128.) examined various combinations of handle vibration frequencies and grip and push force levels upon one's ability to recall those forces using psychophysical methods. The results of that study were promising. The present study is a follow-up experiment that further investigated the potential for using psychophysical force-recall methods to estimate grip and push forces when operating powered hand tools. In this experiment, 20 subjects (10 male, 10 female) grasped and pushed an instrumented handle for 45 s at one of three force levels while it vibrated sinusoidally at one of four frequencies (16, 31.5, 63, or 125 Hz) or with no vibration. Unlike the first study, two levels of vibration magnitude were examined along with gender differences. This study further clarifies relationships between vibration exposure characteristics and their effects on grip and push force-recall performance. Vibration exposure conditions and other influential factors can be accounted for in enhanced force-recall methodologies that can be incorporated into a variety of workplace exposure assessment applications. Relevance to industry Workers who are repeatedly exposed to intense hand-transmitted vibration are at risk of developing health problems. To better assess these health risks, hand–tool coupling forces should be evaluated. A refined psychophysical force-recall technique may be a practical alternative to expensive or fragile instrumentation. Before such a method is proposed for laboratory or field applications, an understanding of vibration effects upon force-recall performance must first be explored.
Band Series in Infra-Red Absorption Spectra of Organic Compounds. II

The absorption bands of secondary intensity occurring, in addition to the more pronounced members of the previously described C-H series, in the short wave-length infra-red spectra of methyl iodide, methylene chloride, methylene bromide, methylene iodide, chloroform and bromoform are accounted for on the basis of linear C-Cl, C-Br, and C-I series starting at 16.8\ensuremath{\mu}, 17.2\ensuremath{\mu} and 17.5\ensuremath{\mu} respectively; and on the basis of simple additive combinations between these frequencies and those of the C-H series.
Sensitivity of a Cloud Microphysical Model to an Urban Environment

Abstract Observations showed increased concentrations of cloud condensation nuclei (CCN) in air samples collected over and downwind of St. Louis when compared to upwind samples. Aircraft observations of urban clouds showed corresponding increased concentrations of cloud base droplets. In addition, observations indicated higher cloud bases and decreased elevations of average first echo base heights in the St. Louis/East St. Louis area as compared with similar clouds over rural areas. The purpose of this paper is to examine the possible role of CCN chemical composition and number concentration in producing the observed phenomena. A closed parcel model of condensation and collection was employed for this purpose. The results suggest that the observed differences of depth from cloud base to first echo height between urban and rural clouds do not result from concentration differences in any CCN size range. Results of model calculations also suggest that variations in chemical composition of the largest CCN (≥1...
Dynamic absorption effects in KrF * amplifiers

The results of transient loss measurements performed in a self-sustained discharge KrF* amplifier are reported. Analysis of these results gives a minimum value of 20 for the effective gain to loss ratiog 0/αeff, indicating that efficient extraction of energy in subpicosecond KrF* amplifiers in the ∼1 J range should be achievable.
Impacts of Aggregation on Relative Performances of Nonsurvey Updating Techniques And Intertemporal Stability of Input–Output Coefficients

In many instances, and for variety of reasons, input–output researchers are compelled to both employ mechanical techniques to update older survey-based tables as well as using more aggregated ones. This combination, however, gives rise to several concerns. The present paper is an attempt to investigate two such questions. First, the effects of aggregation on the accuracy ranking of selected updating methods, and second, the effects of aggregation on intertemporal stability of the input–output coefficients. To probe these issues, three updating methods were selected. These methods are NAIVE or constant coefficient hypothesis, RAS or biproportional method, and LaGrangian optimization technique. Two survey-based tables from the former Soviet Union along with the selected updating techniques are used to generate updated target year’s direct and inverse transaction matrices at four aggregation levels. Comparison of the resultant estimates at these four levels of aggregation with their counterparts in the actual benchmark table reveals that a higher level of aggregation neither affects the rankings of the updating methods nor does it universally and unequivocally leads to a higher degree of intertemporal stability of input–output coefficients.
Photoperiodic responses of a northern and southern ecotype of black cottonwood

Photoperiod is an important signal controlling the onset of dormancy in perennial plants. Short days typically induce growth cessation, the initiation of cold acclimation, the formation of a terminal bud. bud dormancy and other adaptive responses. Photoperiodic ecotypes have evolved in many species with large latitudinal distributions. The photoperiodic responses of two northern (53°35′ and 53°50′N) and two southern (34°10′ and 40°32′N) genotypes of black cottonwood (Populus trichocarpa Torr. & Gray) were characterized by growing trees under a range of photoperiods in the greenhouse and growth chamber. Short days induced bud set in both ecotypes. resulting in trees with fewer leaves and less height growth than trees grown under long days. Short days also enhanced anthocyanin accumulation in the northern ecotype and decreased branching of the southernmost genotype. Two aspects of the photoperiodic response were evaluated for each trail: critical photoperiod. which was defined as the longest photoperiod that elicited a short-day response, and photoperiodic sensitivity, which was defined as the change in response per unit change in photoperiod. For each of the traits analyzed, the northern ecotype had a longer critical photoperiod and greater photoperiodic sensitivity than did the southern ecotype. The short critical photoperiod and reduced photoperiodic sensitivity of the southern ecotype resulted in a significant delay in bud set compared to that of the northern ecotype, even under a 9-h photoperiod. Typically, photoperiodic ecotypes have been characterized as having different critical photoperiods. Ecotypic differences in photoperiodic sensitivity, however, indicate that differences in the photoperiodic response curves cannot be completely described by the critical photoperiod alone. These results also suggest that the critical photoperiod. photoperiodic sensitivity and speed of bud set have a common physiological basis. Bud set occurred earlier hi the northern ecotype primarily because bud scale leaves were initiated earlier. For one of the northern genotypes, leaf primordia that were initialed under long days subsequently differentiated into bud scale leaves after the trees were transferred to a 9-h photoperiod. This demonstrates that primordia initiated under long days are not necessarily committed to becoming foliage leaves. The response to photoperiod did not differ appreciably between the greenhouse and growth chamber conditions that were tested.
Bar synapses and gap junctions in the inner plexiform layer: Synaptic relationships of the interstitial amacrine cell of the retina of the cichlid fish, Astronotus ocellatus

The retina of the cichlid fish, Astronotus ocellatus, contains an unusual class of amacrine cell, the interstitial amacrine cell, which has its soma and processes restricted to a sublamina of the proximal inner plexiform layer. The interstitial amacrine cell is unique in making synapses which contain a presynaptic dense bar specialization. The interstitial amacrine cell makes reciprocal synapses with bipolar cell terminals and is presynaptic to other amacrine cells and to ganglion cell dendrites. Processes of interstitial amacrine cells are connected to each other by large gap junctions.
Recruiting pregnant smokers into a clinical trial: using a network-model managed care organization versus community-based practices.

Abstract Objectives Recruiting pregnant smokers into smoking cessation intervention trials is challenging. Changes in health care systems offer new opportunities to overcome many of the obstacles encountered by researchers attempting to address the significant harm from maternal smoking. Investigators could facilitate smoking cessation study recruitment by collaborating with health care systems that systematically collect patient smoking status and record it in a centralized, retrievable fashion. This paper reports the results of utilizing this novel approach and compares it with a typical decentralized practice-based recruitment strategy. Methods The study was conducted at Massachusetts General Hospital, in Boston, Massachusetts, from 2000 to 2005. Four hundred forty-two pregnant smokers were recruited for a randomized controlled trial of telephone-delivered smoking counseling from two sources: a network-model managed care health plan and community-based practices (CBP). At the health plan, study recruitment was built on an existing system that permitted pregnant smokers to be identified centrally. At the CBPs, identification and referral systems had to be developed at each practice specifically for the study. The two strategies were compared on the efficiency of recruitment, characteristics of enrollees, and study outcome and process measures. Results The health plan strategy generated referrals nearly twice as fast as the CBP strategy (30.4 vs. 17.0 per month), but because referrals were not timely, a large proportion of women from the plan were too advanced in pregnancy to be eligible to enroll in the study. As a result, the two strategies yielded a comparable enrollment rate. Participants from the health plan were older, better educated, less racially diverse, more likely to be living with the baby's father, and less likely to have smokers in their environment. These differences were largely explained by the socioeconomic diversity of women recruited from the CBPs. Smoking cessation outcomes did not differ by recruitment source. Conclusions A recruitment strategy using a health plan's centralized system was more efficient than a practice-based recruitment strategy at identifying potential study participants, but less efficient at generating study participants from the referrals received. Importantly, participants recruited by the two strategies differed by socioeconomic, but not cessation-related, characteristics. To date, recruiting pregnant smokers into intervention studies remains resource intensive and time consuming. Participant identification and recruitment will be greatly enhanced by health system innovations such as implementation of electronic medical records.
The continuity of increasing polynomial operators on ordered topological vector spaces

IN RECENT YEARS there have been many investigations of polynomial operators. On the one hand, they are the natural generalization of the classical polynomials of n variables to general vector spaces and hence fundamental to the study of the differential calculus and analytic functions in topological vector spaces (see, e.g., [l] and [13] respectively). Other classical properties also extend to polynomial operators, e.g., the Weierstrass approximation theorem in various versions (see [14] and [19]), Lagrange and Hermite interpolation [17], and solutions to polynomial equations (see, e.g., [16] and [18] for surveys and [S], [6], and [9] for more recent work). On the other hand, polynomial operators are one of the simplest generalizations of linear operators and share many of their basic properties. In this paper the following classical theorems on the continuity of positive linear maps on ordered topological vector spaces are generalized to increasing polynomial operators. The polynomial integral operators with positive kernels defined by the author in [4] give examples of a wide class of increasing polynomial operators. The theorems on linear operators are due to Nachbin, Namioka, and Schaefer and their statement is adapted from Peressini [15, p. 861, whose terminology we shall also follow.
Active heat transfer enhancement in air cooled heat sinks using integrated centrifugal fans

Abstract The enhancement of convective heat transfer in an air-cooled heat sink using integrated, interdigitated impellers was investigated. The experimentally investigated heat sink is representative of a subcomponent of an unconventional heat exchanger with a loop heat pipe, multiple parallel flat-plate condensers, and integrated, interdigitated centrifugal fans, designed to meet the challenges of thermal management in compact electronic systems. The close integration of impeller blades with heat transfer surfaces results in a decreased thermal resistance per unit pumping power compared to conventional forced convection heat sinks. The fan performance (i.e. fan curve and power consumption) and heat transfer of a single integrated fan heat sink were experimentally characterized for 12 impeller designs and modeled in terms of dimensionless correlations. Correlations were developed to give estimates of the dimensionless fan curve and the dimensionless power curve based on the fan geometry. Additionally, a two-parameter correlation was developed to estimate the dimensionless heat flux based on the fan’s operating point. The heat transfer in the integrated fans was observed to be a function of the operating point (i.e. the rotational speed of the impeller and the flow rate of air), with only a weak direct dependence on the fan geometry. The insensitivity of the heat transfer performance to the impeller geometry greatly simplifies the design process of integrated fan heat sinks because the fan design can be optimized independently of the heat transfer performance. Finally, the heat transfer enhancement (compared to pressure-driven flow at the same flow rate) appears to be due to turbulent flow structures induced by the impeller.
Infrared optics in an airborne environment.

The performance of airborne infrared systems is affected by limitations on weight, size, cost and the available aperture as well as by aerodynamic heating, rain erosion, icing, atmospheric turbulence and poor visibility. Their impact on the design and choice of materials for thermal imagers and seekers is discussed.© (1978) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Thermal conductivity and ballistic-phonon transport in the cross-plane direction of superlattices

Significant reductions in both the in-plane and cross-plane thermal conductivities of superlattices, in comparison to the values calculated from the Fourier heat conduction theory using bulk material properties, have been observed experimentally in recent years. Understanding the mechanisms controlling the thermal conductivities of superlattice structures is of considerable current interest for microelectronic and thermoelectric applications. In this work, models of the thermal conductivity and phonon transport in the direction perpendicular to the film plane of superlattices are established based on solving the phonon Boltzmann transport equation (BTE). Different phonon interface scattering mechanisms are considered, including elastic vs inelastic, and diffuse vs specular scattering of phonons. Numerical solution of the BTE yields the effective temperature distribution, thermal conductivity, and thermal boundary resistance (TBR) of the superlattices. The modeling results show that the effective thermal conductivity of superlattices in the perpendicular direction is generally controlled by phonon transport within each layer and the TBR between different layers. The TBR is no longer an intrinsic property of the interface, but depends on the layer thickness as well as the phonon mean free path. In the thin layer limit, phonon transport within each layer is ballistic, and the TBR dominates the effective thermal conductivity of superlattices. Approximate analytical solutions of the BTE are obtained for this thin-film limit. The modeling results based on partially specular and partially diffuse interface scattering processes are in reasonable agreement with recent experimental data on GaAs/AlAs and Si/Ge superlattices. From the modeling, it is concluded that the cross-plane thermal conductivity of these superlattices is controlled by diffuse and inelastic scattering processes at interfaces. Results of this work suggest that it is possible to make superlattice structures with thermal conductivity totally different from those of their constituting materials.
A status report on infrared detectors

Abstract Infrared photondetectors may be placed into two categories: intrinsic and impurity activated detectors. Intrinsic detectors include film detectors PbS, PbSe, PbTe, and single crystal detectors InSb and InAs. Their spectral response generally rises linearly to the spectral peak, then drops sharply. Typical PbS detectors operated at room temperature have a long wavelength threshold at 3 μ and a detectivity of 1011 cm c/s 1 2 W−1 at 2 μ., their spectral peak. Time constants are of the order of 100 μsec. PbSe and PbTe detectors when operated at liquid nitrogen temperature have a detectivity of about 2 x 1010 cm c/s 1 2 W−1 at their spectral peak between 4 and 6 μ. Time constants vary between 20 and 100 μsec. InSb detectors, when cooled to liquid nitrogen temperature, have a spectral peak in the vicinity of 5 μ and a detectivity of about 4 x 1010 cm c/s 1 2 W−1.Their time constants are of the order of 1 μsec. Impurity activated detectors include Ge and Ge-Si single crystals with impurities such as Au, Cu, Zn, Sb. The spectral response of Ge with the peak at 1.5μ and a cut-off at 1.8 μ is superimposed on the response characteristic of the impurity. Gold extends the response to 9μ, Cu to 30 μ, Zn to 40 μ., and Sb to 120μ. When these detectors are cooled until they are background limited, their detectivity is about 2 x 1010 cm c/s 1 2 W−1 atspectral peak. Time constants of Ge: Au and Ge: Zn detectors are less than 0.1 μsec. Evaluation of the theoretical limit of detectivity indicates that most currently available single crystal detectors approach the theoretical limit to within a factor of two-three; average film detectors, however, differ by a greater amount.
Friction Due to Elastic-Plastic Contact of Rough Surfaces

A three dimensional model based on CEB elastic-plastic contact leads to the derivation of two force components due to the shoulder-shoulder interaction of the asperities. A normal force component is resulted that upon summation of all possible interactions, in a statistical sense, obtains the normal force between the two surfaces. A second component of asperity force would be along the tangential plane (mean plane). When there is not net applied tangential force the tangential component of force on an asperity due to all its interactions would vanish. Upon impending motion, however, the tangential force can no longer cancel since the existence of a net tangential applied load would disrupt the symmetry of loading in the tangential direction. A three dimensional elastic-plastic model then furnishes a half-plane tangential elastic-plastic force term that would exist when relative movement of one surface on another occurs along an arbitrary axis in the tangential plane. This paper addresses an account of friction due to the elastic-plastic interaction of two surfaces by recognizing that the tangential half-plane elasto-plastic force term is the resisting force when two surfaces in elastic-plastic contact are made to slide.Copyright © 2007 by ASME
Scanning electron microscopy of post-ejaculatory spermiogenesis in the tick Ornithodoros moubata.

Abstract The final stages of spermiogenesis in ticks occur in the female genital tract. Scanning electron microscopy was used to follow the morphologic changes that occur in the sperm during this post-ejaculatory spermiogenesis in the African soft tick, Ornithodoros moubata , and to determine a time sequence for its occurrence in vivo . Characteristic features of the maturing and mature cell described include (1) differentiation and detachment of the operculum, (2) changes in cell shape corresponding to different developmental stages, (3) passive migration of the nucleus and acrosome from an anterior to a posterior position, and (4) eversion of that portion of the acrosomal canal containing the nucleus and acrosome. A possible fate for the remainder of the acrosomal canal is suggested by extrusion and detachment of spherical structures, the ‘posterior bubbles’, from the posterior end of the mature supermatozoon. A mechanism for cellular elongation resulting from contractions of the outer sheath is proposed.