cssi/SciSciGPT-SciSciNet huggingface dataset:
Inhibition of pancreatic cancer stem cells by Rauwolfia vomitoria extract

The poor treatment outcomes of pancreatic cancer are linked to an enrichment of cancer stem cells (CSCs) in these tumors, which are resistant to chemotherapy and promote metastasis and tumor recurrence. The present study investigated an extract from the root of the medicinal plant Rauwolfia vomitoria (Rau) for its activity against pancreatic CSCs. In vitro tumor spheroid formation and CSC markers were tested, and in vivo tumorigenicity was evaluated in nude mice. Rau inhibited the overall proliferation of human pancreatic cancer cell lines with a 50% inhibitory concentration (IC50) ranging between 125 and 325 µg/ml, and showed limited cytotoxicity towards normal epithelial cells. The pancreatic CSC population, identified using cell surface markers or a tumor spheroid formation assay, was significantly reduced, with an IC50 value of ~100 µg/ml treatment for 48 h and ~27 µg/ml for long-term tumor spheroid formation. The levels of CSC-related gene Nanog and nuclear β-catenin were decreased, suggesting suppression of the Wnt/β-catenin signaling pathway. In vivo, 20 mg/kg of Rau administered five times per week by oral gavage significantly reduced the tumorigenicity of PANC-1 cells in immunocompromised mice. Taken together, these data showed that Rau preferentially inhibited pancreatic cancer stem cells. Further investigation is warranted to examine the potential of Rau as a novel treatment for pancreatic cancer.
The Role of Government, Nonprofit, and Private Facilitation of the Impact Investing Marketplace

This article examines the public, private, and nonprofit facilitators at play in the growing field of impact investing, explores their roles, and proposes market rationales for their involvement. W...
Acute N-Acetylcysteine Administration Ameliorates Loss of Olfactory Neurons Following Experimental Injury In Vivo.

The olfactory epithelium (OE) is the peripheral organ for the sense of smell, housing primary sensory neurons that project axons from the nose to the brain. Due to the presence of a basal stem cell niche, the adult mammalian OE is a dynamic tissue capable of replacing neurons following their loss. Nonetheless, certain conditions, such as blunt head trauma, can result in persistent olfactory loss, thought to be due to shearing of olfactory nerve filaments at the skull base, degeneration, and failures in proper regeneration/reinnervation. The identification of new treatment strategies aimed at preventing degeneration of olfactory neurons is, therefore, needed. In considering potential therapies, we have focused on N-acetylcysteine (NAC), a glutathione substrate shown to be neuroprotective, with a record of safe clinical use. Here, we have tested the use of NAC in an animal model of olfactory degeneration. Administered acutely, we found that NAC (100 mg/kg, twice daily) resulted in a reduction of olfactory neuronal loss from the OE of the nose following surgical ablation of the olfactory bulb. At 1 week postlesion, we identified 54 ± 8.1 mature neurons per 0.5 mm epithelium in NAC-treated animals vs. 28 ± 4.2 in vehicle-treated controls (P = 0.02). Furthermore, in an olfactory cell culture model, we have identified significant alterations in the expression of several genes involved in oxidative stress pathways following NAC exposure. Our results provide evidence supporting the potential therapeutic utility for NAC acutely following head trauma-induced olfactory loss. Anat Rec, 303:626-633, 2020. © 2019 American Association for Anatomy.
Intravenous Fish Oil and Serum Fatty Acid Profiles in Pediatric Patients With Intestinal Failure-Associated Liver Disease.

BACKGROUND Intravenous fish oil (FO) treats pediatric intestinal failure-associated liver disease (IFALD). There are concerns that a lipid emulsion composed of ω-3 fatty acids will cause an essential fatty acid deficiency (EFAD). This study's objective was to quantify the risk for abnormal fatty acid concentrations in children treated with FO. METHODS Inclusion criteria for this prospective study were children with intestinal failure. Intravenous soybean oil (SO) was replaced with FO for no longer than 6 months. Serum fatty acids were analyzed using linear and logistic models, and compared with age-based norms to determine the percentage of subjects with low and high concentrations. RESULTS Subjects (n = 17) started receiving FO at a median of 3.6 months (interquartile range 2.4-9.6 months). Over time, α-linolenic, linoleic, arachidonic, and Mead acid decreased, whereas docosahexaenoic and eicosapentaenoic acid increased (P < 0.001 for all). Triene-tetraene ratios remained unchanged (P = 1). Although subjects were 1.8 times more likely to develop a low linoleic acid while receiving FO vs SO (95% CI: 1.4-2.3, P < 0.01), there was not a significant risk for low arachidonic acid. Subjects were 1.6 times more likely to develop high docosahexaenoic acid while receiving FO vs SO; however, this was not significant (95% CI: 0.9-2.6, P = 0.08). CONCLUSION In this cohort of parenteral nutrition-dependent children, switching from SO to FO led to a decrease in essential fatty acid concentrations, but an EFAD was not evident. Low and high levels of fatty acids developed. Further investigation is needed to clarify if this is clinically significant.
Oak Savannas in Western New York State, Circa 1795: Synthesizing Predictive Spatial Models and Historical Accounts to Understand Environmental and Native American Influences

This study models and maps oak savanna distribution ca. 1795 and determines how environmental conditions and Native American land use (NALU) shaped its distribution. Historical research has analyze...
Economics-Oriented Discourse Strategies in Environmental Advocacy

Scholars and practitioners are engaging in a fierce debate over the implications of using market-based discourse in communicating environmental problems and solutions. However, there has been less ...
Cultural Betrayal as a Dimension of Traumatic Harm: Violence and PTSS among Ethnic Minority Emerging Adults.

According to cultural betrayal trauma theory, within-group violence confers a cultural betrayal that contributes to outcomes, including symptoms of posttraumatic stress disorder (PTSS). Close relationship with the perpetrator, known as high betrayal, also impacts PTSS. The purpose of the current study is to examine cultural betrayal trauma, high betrayal trauma, and PTSS in a sample of diverse ethnic minority emerging adults. Participants (N = 296) completed the one-hour questionnaire online. Hierarchical linear regression analyses revealed that when controlling for gender, ethnicity, and interracial trauma, high betrayal trauma and cultural betrayal trauma were associated with PTSS. Clinical interventions can include assessments of the relationship with and in-group status of the perpetrator(s) in order to guide treatment planning with diverse survivors.
Value of Anti-Vascular Endothelial Growth Factor Gene Therapy for Neovascular Age-Related Macular Degeneration.

Purpose To use discounted cash flow (DCF) analysis to estimate the value creation associated with anti–vascular endothelial growth factor (VEGF) genetic therapy for neovascular age-related macular degeneration (nAMD). Design Economic analysis. Participants Adults undergoing serial intravitreal anti-VEGF injections in 1 eye for nAMD. Methods Discounted cash flow modeling with scenario analysis was used to derive a present value for a 1-time alternative treatment to lifelong anti-VEGF treatment for nAMD. Multiple sensitivity analyses were performed on the basis of patient age at time of first injection and frequency interval of intravitreal injection. Main Outcome Measures Present values of DCF and scenario analyses. Results Discounted cash flow analysis of intravitreal anti-VEGF treatment for nAMD resulted in a base-case valuation of $208 420.61, $219 093.31, and $17 379.41 for a 1-time alternative treatment to aflibercept, ranibizumab, and bevacizumab, respectively. This figure covaried significantly with anti-VEGF agent according to the patient age at first injection ($78 323.19–$292 449.87) and frequency of injections ($148 422.91–$388 096.81). In addition, for bevacizumab, variability was driven by the hypothetical degree of clinical superiority of 1-time therapy to repeated intravitreal injections due to reduction in adverse events ($17 379.41–$18 250.79) or reduction in direct or indirect costs associated with age-related macular degeneration ($17 379.41–$657 406.55). Conclusions Anti-VEGF gene therapy approaches can create significantly different value propositions based on the agent modeled, patient age at first injection, frequency of injections, and clinical profile of the medication. Although the use of aflibercept or ranibizumab as a comparative cost metric is logical from a bioequivalence perspective, the disparity in medication costs should not be the primary value driver in applied models. Instead, bevacizumab should be the base case ($17 379.41), with additional value driven from an improvement in quality of life through clinical superiority. A reduction in direct and indirect costs can be used to approximate the value from maintained visual acuity, which is elaborated in the DCF analysis approach described in this article. This model can serve as a basis for assessing the price ceiling of myriad gene therapy approaches. Given the high present values for these therapeutics, innovative costing and reimbursement mechanisms should be further explored, with contingencies for sustained efficacy.
Validation of the two-region Rossi-alpha model for reflected assemblies

Abstract Nuclear criticality safety, nonproliferation and safeguards, emergency response, and stockpile stewardship utilize estimates of the k eff multiplication factor. The value of k eff cannot be directly measured, but it can be inferred from the prompt neutron period. One modality of measuring the prompt neutron period is the Rossi-alpha method, which is predicated on fitting a histogram of detection time differences due to the nonrandom temporal distribution of same-fission-chain neutrons. Recent works have developed the motivation and theory to expand traditional one-region point kinetic models resulting in one-exponential histogram fits to two-region models that result in two-exponential fits. This paper validates the new two-region model using organic scintillator measurements of copper-reflected weapons-grade plutonium ( 0 . 83 ≤ k eff ≤ 0 . 94 ) and high-density-polyethylene-reflected highly enriched uranium ( 0 . 73 ≤ k eff ≤ 0 . 95 ). Furthermore, the results show that more thermal systems have shorter prompt neutron periods in the core region due to increased induced-fission probabilities for moderated neutrons. A new parameter introduced by the two-region model is also shown to be correlated to the amount of reflection, and may be used to infer assembly properties such as type and amount of reflector.
Romantic Relationship Conflict Due to the COVID-19 Pandemic and Changes in Intimate and Sexual Behaviors in a Nationally Representative Sample of American Adults

In early 2020, the novel coronavirus 2019 (COVID-19) spread across the United States and mitigation measures drastically affected the daily lives of Americans. In this study, we assessed the association between COVID-related relationship conflict and changes in intimate and sexual behaviors and experiences. Using data from an online nationally representative probability survey of 1,010 American adults in April 2020, we estimated the impact of coronavirus-related relationship conflict on changes in intimate and sexual behaviors among those in any type of romantic or sexual relationship (Nweighted=742). Further, we assessed the association between conflict and experience of orgasm and feeling emotionally close to partner. Among individuals in relationships, 34% reported some degree of conflict with their romantic partners due to the spread of COVID-19 and its related restrictions. Those experiencing frequent coronavirus-related conflict with their partner were significantly more likely to report decreased frequency of several solo and partnered intimate and sexual behaviors compared to those not experiencing any such conflict, exhibiting a dose-response trend among partnered sexual behaviors. Since the spread of coronavirus and associated social distancing measures in the United States, Americans have experienced escalations in conflict in their romantic partnerships, which was associated with changes to their intimate and sexual lives.
Ecological Psychology Meets Ecology: Apis mellifera as a Model for Perception-Action, Social Dynamics, and Human Factors

Previous ecological research on social dynamics has largely been conducted on human dyads; however, to provide support for Hume's touchstone, ecological psychologists must also investigate the perc...
The 2-Categorical Structure of Predicate Theories

The equivalence of formal languages with categories has long been expounded, notably by [10.1007/BFb0066201], relating coherent categories with predicate logic, where coherent functors serve as translations between predicate theories. This equivalence yielded remarkable results connecting syntax to semantics, but the formalism relied upon category theory. Work by [arXiv:1506.04675,arXiv:1507.02302,10.1017/9781316275603] proposed syntactical notions of equivalence and translation of theories. In this paper, we demonstrate that these syntactical notions are equivalent to the categorical formalism, allowing us to present Makkai and Reyes' conceptual completeness of coherent logic in a syntactical form and to explain and remove the required hypotheses of the translations in [10.1017/9781316275603]. Our equivalence elucidates the relation between categorical equivalence and Morita equivalence, and it reveals necessary and sufficient conditions for when a theory is intertranslatable with or Morita equivalent to a propositional theory.
Network Perspectives on Communities

Abstract: The application of network perspectives to communities requires some appreciation of the variety of ways people are now writing about communities. Some scholars and practitioners have drifted toward the view that a community is composed very largely of the personal networks of the individuals who are members of the community. But the whole community is more than the sum of those related parts, and the structure of a community must include not only those direct interpersonal relations but also the relations among the clusters and groups and corporate entities that interact in and about this whole. If scientific knowledge about these matters is to accumulate, we must be able to compare findings among various studies. From the 1940s well into the 1960s the local community was the recognized social unit that sociologists and anthropologists studied. Linton wrote of the necessity of the local group. Many sociologists and anthropologists gave their full attention to this local level of social integration through a field called “community studies.” The work of Conrad Arensberg, Sol Kimball, Carl Taylor, Robert Redfield, and others had views of communities that had a network cast to them. The category “community” includes a wide range of social formations, generally local systems of fairly densely connected persons in households and organizations, systems on a scale somewhere between those domestic households and the wider society -- state or nation. Recently scholarly focus has shifted to individuals and their personal networks, with less attention to the social structures in which they are embedded. The concept “community” really needs to be defined because it is used in many situations where what it means has real consequences. A network perspective suggests a whole complex social system organized in levels, from a household/family level, upward through a hierarchy of levels, to the national (nation-state) and even beyond that to a supranational (above-state) level. Within that complete social system are embedded several levels of networks that could be called community. The networks that form such a community must be sorted out from the entire complex system. A network perspective on communities – or on structures relating to communities – includes seeing groups both as networks of the individuals composing them and as nodes related to each other through their common members. Such “affiliation networks” are more complex than just the sum of the personal networks. Improved techniques of data collection and data analysis are bringing us closer to sorting subsystems in ways that permit their proper comparison. Gaps or seams between segments or clusters, structural equivalence, structural holes, regular equivalence, role analysis, and block modeling are improving our understanding of systems at all levels. We are approaching an understanding of the concept of community in network perspective.
CVT gear ratio control as an engine braking actuator for vehicle automatic deceleration

In this paper, engine braking control by Continuous Variable gear ratio Transmission (CVT) and its design method are proposed. This control enables to follow target vehicle deceleration in stable and good response. First, kinetic equations of vehicle deceleration are shown. Second, control design concept is derived from these equations. Next, the concept is embodied as H-infinity control problem, and controller is obtained from it. Finally, the controller is applied for Adaptive Cruise Control (ACC) and verified with experiment.
Steady state mRNA levels in tree shrew sclera with form-deprivation myopia and during recovery.

PURPOSE In tree shrews, visual form deprivation induces myopia and tissue remodeling in the sclera, characterized by decreased levels of collagen and glycosaminoglycans (GAGs) and increased levels of matrix metalloproteinases (MMPs). Removal of the visual deprivation allows recovery. This study investigated whether these changes are accompanied by changes in steady state mRNA levels in the sclera. METHODS Quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR) was used to measure steady state levels of mRNA for collagen (alpha1(I) chain), decorin (core protein), gelatinase-A (MMP-2), stromelysin-1 (MMP-3), and a tissue inhibitor of metalloproteinase (TIMP-1) in the scleras of tree shrews that received either 11 days of monocular form deprivation (MD) or 11 days of MD followed by 4 days of recovery. A group of age-matched normal animals was also measured. RESULTS After 11 days of MD, alpha1(I) collagen mRNA levels were 34% lower, and MMP-2 mRNA levels were 66% higher in the deprived eyes than in the control eyes. After 4 days of recovery, collagen mRNA levels were 33% higher, MMP-2 levels were 20% lower, and TIMP-1 levels were 43% higher in the recovering eyes than in the control eyes. Decorin and MMP-3 mRNA levels were not significantly different between the treated and control eyes after MD or after recovery. CONCLUSIONS The tissue remodeling in mammalian sclera induced by altering the visual environment is accompanied by modulation of mRNA levels in the sclera. The levels of collagen and MMP-2 mRNA were modulated in a pattern generally consistent with observed changes in protein levels, suggesting that visual regulation of the levels of these scleral proteins may involve modulation of gene expression at the transcriptional level.
X-ray Diffraction of Cotton Treated with Neutralized Vegetable Oil-based Macromolecular Crosslinkers:

Maleinized soybean oil (MSO) has been investigated as a flexible, macromolecular crosslinker for cotton fabrics. The ability of MSO to penetrate crystalline cellulose and crosslink aligned cellulose chains upon cure has been in question. This study compares the penetration capability of MSO to dimethyloldihydroxyethyleneurea (DMDHEU), which is the commercial standard for durable press finishing and is an efficient cellulose crosslinker. Xray diffraction was employed to characterize changes in the crystalline morphology upon heating unmercerized cotton fabrics treated with aqueous DMDHEU and soybean oil derivatives. Displacement of characteristic interplanar spacings and the genesis/elimination of diffraction intensities from quintessential planes were evidence of structural modification. The penetration of ammonia neutralized MSO (acid value 230.00 mg KOH/g) into the microstructure of cotton cellulose is similar to that of DMDHEU in terms of expanding the interplanar spacings of characteristic planes. Moreover, polymorphism of cotton and mercerized cotton occurred upon treatment with aqueous solutions of MSO. These findings suggest that macromolecular reagents can diffuse into cellulose fibrils if they are sufficiently hydrated or enshrouded by more favored penetrants.
Signing Statements as Bargaining Outcomes: Evidence from the Bush Administration

A number of recent studies have documented some of the reasons presidents issue signing statements (written pronouncements made by the president when signing a bill into law). I argue that signing statements help construct defenses – for example, for bureaucrats deciding how to implement a law, or for judges deciding whether a particular interpretation is consistent with the Constitution. I argue that presidents construct more detailed and complex defenses under certain conditions, including when his ideal point is distant from Congress. I test this hypothesis and others using data from the George W. Bush administration between 2001 and 2006. Both the number of objections applied to a given bill and their complexity increase when the president is distant from Congress. This result and others help explain when presidents use signing statements to construct defenses.
Solid-state 207Pb nuclear magnetic resonance studies of adducts of 1,10-phenanthroline with lead(II) halides

Experimental and predicted 207Pb nuclear magnetic resonance (NMR) parameters of solid-state coordination complexes of lead(II) bromide, lead(II) iodide, and lead(II) chloride with 1,10-phenanthroline are reported. Structural and electronic differences between the 1:1 and 1:2 adducts are reflected by the NMR parameters. The NMR chemical shieldings of the isostructural complexes indicate that the electronic state of the lead(II) center depends on the number of ligands and the halogen anion. The NMR results suggest that the 1:2 adduct may be more stereochemically active than the 1:1 adduct.
Effects of different design parameters on the stone-impact resistance of automotive windshields:

AbstractA constitutive model based on continuum damage mechanics is used to study the stone-impact resistance of automotive windshields. An axisymmetric finite element model is created to simulate the transient dynamic response and impact-induced damage tensors for laminated glass layers subject to stone-impact loading. The windshield glass consists of two glass outer layers laminated by a thin poly(vinyl butyral) (PVB) layer. The constitutive behaviour of the glass layers is simulated using the continuum damage mechanics model with linear damage evolution. The PVB layer is modelled with a linear viscoelastic solid. The model is used to predict and examine damage patterns on different glass surfaces for different windshield designs including variations in ply thickness and curvatures.
Maternal Sensitivity and the Visual Attentiveness of Children Who Are Deaf

Maternal sensitivity may be even more important for the development of deaf infants' social and cognitive competence than previous research has shown it to be for hearing children. We report ratings of mothers' sensitivity and infants' time in coordinated joint attention (CJA) during play interactions video-taped in a laboratory at 9,12 and 18 months. Participants include 80 dyads in four groups: two matched for hearing status (Deaf or Hearing mothers with deaf or hearing babies), two unmatched for hearing status (Deaf mothers/hearing babies and Hearing mothers/deaf babies). Mothers in matched dyads were rated more sensitive than mothers in unmatched dyads. Deaf infants with Deaf mothers showed more time in CJA compared to infants in unmatched dyads. However, significant correlations of sensitivity and attention were found only for the two unmatched hearing status groups at 18 months. These results are discussed in terms of dyadic hearing status differences, intuitive parenting and developmental stage. © 1996 John Wiley & Sons, Ltd.
Membrane adsorption of β2-microglobulin: Equilibrium and kinetic characterization

Membrane adsorption of β 2 -microglobulin: Equilibrium and kinetic characterization. Enhanced extracorporeal removal of β 2 -microglobulin (β 2 m) may prevent the development of dialysis-related amyloidosis (DRA). One mechanism of β 2 m removal is membrane adsorption. Therefore, we fundamentally characterized β 2 m adsorption to the highly permeable polyacrylonitrile (PAN) membrane. Porous and nonporous PAN fragments were incubated in buffer containing 125 I-β 2 m. Over a concentration range of 8 to 60 mg/liter, the equilibrium adsorption isotherm was linear (r = 0.99) for porous PAN while the isotherm for nonporous PAN suggested either multilayer binding or adsorption of proteins with differing orientations. In kinetic analyses, the approach to equilibrium versus (time) 1/2 was evaluated. For both porous and nonporous PAN, this relationship was linear (r = 0.99), consistent with a diffusion-controlled process. Adsorption reversibility was assessed by comparing the amount bound at varying residence times (0 to 4 hr) to the amount remaining adsorbed after a subsequent incubation in buffer. The fractions remaining bound at 60, 120, and 240 minutes (0.34 ± 0.02, 0.36 ± 0.06, and 0.44 ± 0.03; mean ± SEM) were significantly greater (P 2 m. This investigation permits the comparison of β 2 m adsorptive properties of PAN to those of other membrane-based and nonmembrane-based therapies designed to prevent DRA.
A trinuclear Fe-Fe-Ni complex formed by ligand reshuffling.

The title complex, dicarbonyl-3κ2 C-(μ3-3,6-dimethyl-3,6-diaza­octane-1,8-dithiol­ato-1:2:3κ7 S:S,N,N′,S′:S,S′)(μ2-3,6-di­methyl-3,6-diaza­octane-1,8-dithiol­ato-1:2κ5 S,N,N′,S′:S)-1,2-diiron(II)-3-nickel(0) [Fe2Ni(C8H18N2S2)2(CO)2], is the second example showing M(μ-SR)2Ni0(CO)2 coordination (M = any metal atom). Both FeII ions are five-coordinated in distorted trigonal–bipyramidal geometries by two N atoms and three S atoms. The Ni atom is four-coordinated in a distorted tetra­hedral geometry by two S atoms and two carbonyl ligands. One of the 3,6-dimethyl-3,6-diaza­octane-1,8-dithiol­ate ligands is disordered, the major component having a refined occupancy of 0.873 (2). The Fe⋯Fe distance is 3.0945 (3)A and the Ni⋯Fe distance is 2.8505 (3) A.
Design criteria of a fluidized bed oyster nursery

Abstract A fluidized bed oyster nursery is an innovative application of fluidization to the high-density culture of cultchless oysters, from 2–3 to 20–25 mm in size. Oysters are suspended in an upward flowing fluid. Feed water flow is uniformly distributed and feces are transported out of the system by the feed water. A critical design parameter for a fluidized bed oyster nursery is the fluid velocity at which minimum fluidization occurs, vmf. This velocity was found to be a function of the average height of the largest-sized 90% of the oysters in the bed. v mf = −4.0+1· H ave ,90 − 0·15 ( H ave ,90) 2 , r 2 =0·96 where vmf = velocity at minimum fluidization (cm/s), Have, 90 = average height of the largest-sized 90% of oysters (mm). Juvenile oysters, cultured in an experimental fluidized bed nursery and fed shrimp pond effluent, exhibited exponential growth. Growth rates compared well with those achieved for post-nursery oysters grown on strips and in trays at the same site.
Gifted Females: A Comparison of Attitudes by Male and Female Teachers.

(1984). Gifted females: A comparison of attitudes by male and female teachers. Roeper Review: Vol. 6, No. 3, pp. 164-167.
The role of radiation effects in SOI technology development

The technical development of radiation resistant CMOS/SOI technologies is reviewed. Inherent hardness of SOI to dose rate upset and latchup has leveraged major developments of SOI technologies. TID hardness for up to the 150nm node was addressed by process hardening. Inherent hardness of 45nm and 32nm technologies reduced the need for TID hardening. As technology is scaled to 28nm and 14nm nodes TID hardening is again required. SEU hardening is addressed by circuit design for a wide range of technologies with significant SEU improvement for 28nm and 14nm is observed.
Chemotherapy-induced cardiomyopathy

Improvement in cancer therapy has led to an increasing number of cancer survivors, some of whom may suffer from the cardiotoxic effects of chemotherapy. Cardiomyopathy can occur years after completion of the chemotherapy and it is important to recognize this early, as complete recovery of cardiac function is possible in some cases. In this article we will review chemotherapy-induced cardiomyopathy and discuss its treatment options.
Improving the effectivity of residual based a posteriori error estimates using a statistical approach

Abstract For the approximation of differential equations residual based error estimates provide upper bounds (usually gross over estimates) to the true error. In this paper we present a procedure for determining values for the constants in the a posteriori estimates which yield accurate estimates to the true error. Numerical experiments demonstrating the effectiveness of the method are given.
Protein Kinase C and Receptor Kinase Gene Expression in Olfactory Receptor Neurons

Recent biochemical evidence indicates that protein kinase C (PKC) and G-protein-coupled receptor kinases (GRKs) are involved in olfactory signal termination and desensitization. The polymerase chain reaction (PCR) was used to investigate the expression of PKC and GRK genes in olfactory tissue and in isolated olfactory receptor neurons from channel catfish (Ictalurus punctatus). Sequence analysis of cloned PKC PCR products showed that the alpha, beta, delta, epsilon, and theta isotypes were expressed in olfactory tissue. Sequence analysis of PCR products obtained from isolated olfactory receptor neurons showed that PKC beta and PKC delta were expressed in the receptor cells. A 600-bp GRK PCR product was obtained from isolated olfactory neurons that shared 86% and 92% amino acid sequence identity to the mammalian beta-adrenergic receptor kinase gene products beta ARK1 and beta ARK2, respectively. Go6976, a specific inhibitor of calcium-regulated PKC activity, completely inhibited odorant-stimulated PKC activity in isolated olfactory cilia. This result suggested that odorant-stimulated PKC activity is mediated by the calcium-sensitive PKC beta isotype. Taken together, these results are consistent with the conclusion that PKC beta and beta ARK mediate odorant receptor phosphorylation and olfactory signal termination.
Retransmission Delays With Bounded Packets: Power-Law Body and Exponential Tail

Retransmissions serve as the basic building block that communication protocols use to achieve reliable data transfer. Until recently, the number of retransmissions was thought to follow a geometric (light-tailed) distribution. However, recent work shows that when the distribution of the packet sizes have infinite support, retransmission-based protocols may result in heavy-tailed delays and possibly zero throughput even when the aforementioned distribution is light-tailed. In reality, however, packet sizes are often bounded by the maximum transmission unit (MTU), and thus the aforementioned result merits a deeper investigation. To that end, in this paper, we allow the distribution of the packet size $L$ to have finite support. Under mild conditions, we show that the transmission duration distribution exhibits a transition from a power-law main body to an exponential tail. The timescale to observe the power-law main body is roughly equal to the average transmission duration of the longest packet. The power-law main body, if significant, may cause the channel throughput to be very close to zero. These theoretical findings provide an understanding on why some empirical measurements suggest heavy tails. We use these results to further highlight the engineering implications of distributions with power-law main bodies and light tails by analyzing two cases: 1) the throughput of on–off channels with retransmissions, where we show that even when packet sizes have small means and bounded support the variability in their sizes can greatly impact system performance; 2) the distribution of the number of jobs in an $M/M/\infty$ queue with server failures. Here, we show that retransmissions can cause long-range dependence and quantify the impact of the maximum job sizes on the long-range dependence.
Surface Functionalization of Alkyl Monolayers by Free-Radical Activation: Gas-Phase Photochlorination with Cl2

We report the gas-phase photochlorination of methyl-terminated alkyl monolayers on silicon. We argue that this process proceeds by a free-radical mechanism, as is the case for homogeneous photochlorination. This is an example of what should be a family of convenient methods for the incorporation of various functional groups into simple alkyl monolayers by chlorine-radical activation. Monolayers prepared from 1-octadecene on Si(111) were exposed to Cl2 with illumination at 350 nm. We observe that a fraction of the carbon atoms on the surface become singly chlorinated and a smaller fraction become doubly chlorinated, as measured by the chemically shifted components of the C 1s X-ray photoelectron spectrum. The elemental composition of the resulting monolayers, film thickness, and contact angles are reported as a function of exposure. Under conditions that chlorinate only a fraction of the carbon atoms, IR spectroscopy reveals complete chlorination of the methyl groups, demonstrating a strong steric preferen...
The Antiherpetic Drug Acyclovir Inhibits HIV Replication and Selects the V75I Reverse Transcriptase Multidrug Resistance Mutation

The antiviral drug acyclovir is a guanosine nucleoside analog that potently inhibits herpes simplex virus (HSV) replication. Acyclovir treatment in patients coinfected with HSV and human immunodeficiency virus (HIV) has been observed to alter disease course and decrease HIV viral load, a finding that has been attributed to indirect effects of HSV suppression on HIV replication. Based on this hypothesis, several clinical studies have recently investigated the use of acyclovir for treatment of patients coinfected with HSV and HIV or for prophylaxis against HIV transmission. In this report, we use a single round HIV infectivity assay to show that acyclovir directly inhibits HIV infection with an IC50 of ∼5 μm. The target of acyclovir in HIV-infected cells is validated as HIV reverse transcriptase (RT) by the emergence of the RT variant V75I under the selective pressure of acyclovir. The V75I mutation is part of the multidrug resistance pathway that enhances viral resistance to many of the best RT inhibitors approved for the treatment of HIV. Biochemical analyses demonstrate that acyclovir triphosphate is a chain terminator substrate for HIV RT and can compete with dGTP for incorporation into DNA. Although acyclovir may prove a useful lead for development of new HIV treatments, the selection of resistant mutants raises a cautionary note to the use of acyclovir monotherapy in patients coinfected with HSV and HIV.
Quantitative calculations of temporomandibular joint reaction forces-II. The importance of the direction of the jaw muscle forces

The effect of measurement errors on quantitative calculation of temporomandibular joint reaction force was investigated in a two-dimensional, two-muscle model. A computer program using the model incremented the magnitude of the bite force and muscle forces and the lengths of their moment arms, and calculated the joint reaction force at each increment. Computation of the joint reaction force is most sensitive to the relative lengths of the bite force and muscle forces moment arms. Absolute values for each muscle force are not required and errors in the magnitudes of the muscle forces have only a minor effect on calculation of the total joint reaction force.
Evaluation of various methods of weed control for increasing rhubarb yields

Abstract Four herbicides, monthly handweeding and a 15 cm deep straw mulch were evaluated for weed control during 1982 to 1987 on rhubarb (Rheum rhabarbarum L. ≡ R. rhaponticum L. ‘Victoria Red’). The straw-mulched plots produced larger plants, provided higher yields and had fewer weeds than all other treatments during the five years of these field trials. Yields in 1987 were 29·42, 17·65 and 13·06 tonnes/hectare for straw, handweeded and herbicide treatments, respectively. Monthly handweeding produced large plants and high yields, but required much more hand labour than mulching, making straw mulch the most cost-effective treatment. The four herbicides evaluated (glyphosate, fluazifop, sethoxydim and propyzamide) provided weed control for up to 1 month and would require reapplication during the growing season.
The URCA process at high temperatures and densities

The URCA neutrino loss rate from a hot stellar environment is investigated. The results indicate that the loss rates for URCA type processes from even mass number nuclei are comparable to the rates from odd mass number nuclei at temperatures above about 109 K. Rates are calculated for some typical odd mass isobar pairs and for the even mass isobar fifty-six for temperatures between 5×108 K to 5×1010 K.
In vitro phosphorylation of BRCA2 by the checkpoint kinase CHEK2

Germline mutations in both BRCA2 and CHEK2 are associated with an increased risk for male breast cancer. To search for potential interactions between the products of these breast cancer susceptibility genes, we undertook systematic mapping of BRCA2 for potential phosphorylation sites by CHEK2. In vitro kinase assays and mass spectrometric analysis identified a 50 amino-acid fragment within the N-terminus of BRCA2 potentially targeted by CHEK2, containing two major phosphopeptides. Inducible overexpression of this peptide, but not a derivative with mutated phosphorylation sites, leads to increased chromosome fragmentation and suppression of cellular proliferation. These results suggest a link between CHEK2 and BRCA2 pathways, which may contribute to the spectrum of cancers associated with germline CHEK2 mutations.
Environmental performance of state-owned and privatized eastern European energy utilities

Abstract Privatization in Eastern Europe has helped in the transition of the region's economies from planned to free market. However, the effects of privatization on the environment are relatively unknown and many firms remain under state ownership today. We compare the environmental performance of state-owned and privatized energy utility plants in Eastern Europe utilizing a novel panel data that includes reported sulfur dioxide emissions, energy input, and ownership status. We find that state-owned plants emit more sulfur dioxide than privately owned plants; this is environmentally significant as privatization is associated with a reduction in emissions of about 55%.
Fluorescence-based zinc ion sensor for zinc ion release from pancreatic cells.

In this paper, we describe the synthesis and characterization of analytical properties of fluorescence-based zinc ion-sensing glass slides and their application in monitoring zinc ion release from beta pancreatic cells in cell cultures. To fabricate the sensors, the zinc ion indicator ZnAF-2 {6-[N-[N‘,N‘-bis(2-pyridinylmethyl)-2-aminoethyl]amino-3‘,6‘-dihydroxyspiro[isobenzofuran-1(3H),9‘-[9H]xanthene]-3-one} was modified to include a sufficiently long linking aliphatic chain with a terminal carboxyl functional group. The recently synthesized ZnAF-2 zinc ion indicator provided high zinc ion selectivity in physiological solutions containing millimolar levels of calcium and other possible interfering cations. The carboxyl-modified ZnAF-2 was conjugated to the activated surface of glass slides, which then served as zinc ion sensors. It was possible to grow pancreatic cells directly on the zinc-sensing glass slide or on a membrane placed on these glass slides. The sensors were used to monitor zinc ion release...
A Randomized Study of Phosphate Therapy in the Treatment of Diabetic Ketoacidosis

The use of phosphate therapy in the management of diabetic ketoacidosis (DKA) has been controversial, particularly with respect to the effect of phosphate intermediates on tissue oxygenation. In a prospective randomized study we evaluated the effect of phosphate (8.5 mmol/h or approximately 6 g phosphate/24 h) (experimental group) vs. no phosphate therapy (control group) in 30 DKA patients, 15 in each group. Various determinations including erythrocyte 2,3-diphosphoglycerate (2,3-DPG), oxyhemoglobin dissociation (p50), serum phosphate, calcium, lactate, pyruvate, electrolytes, and response time to reach predetermined values for glucose, bicarbonate, and pH were measured at frequent intervals during the first 24 h of therapy and daily for 5 days after metabolic control. Initial electrolytes, glucose, pH, erythrocyte 2,3-DPG, lactate, and p50 were not different in either group. Whereas the experimental group had a greater level of 2,3-DPG than the control group by 48 h, the difference was not statistically significant. Recovery indices, including hours to reach glucose of 250 mg/dl, bicarbonate greater than 15 meq/liter, pH greater than 7.3, and mental alertness, were not different in the two groups nor were the p50 or lactate measurements. The experimental group exhibited significantly lower plasma ionized calcium values during therapy. We conclude that phosphate therapy may accelerate regeneration of erythrocyte 2,3-DPG but in the relatively small number of patients studied it had no demonstrable influence on tissue oxygenation or clinical response to low dose insulin therapy of DKA. Furthermore, the exaggeration of hypocalcemia seen in phosphate-treated patients may be reason for caution in the use of such therapy.
A case study on the effects of a retrofitted dementia special care unit on resident behaviors

The need to demonstrate the efficacy of special care units (SCUs) is of primary concern to consumers who increasingly demand accountability for health delivery services. The present study describes...
The role of comprehension in remembering sentences

Abstract Most contemporary theories of sentence memory tacitly assume that a complete linguistic analysis of a sentence would provide all of the necessary and sufficient information for characterizing its memory representation. The present research was designed to show that the memory representation of a sentence can contain more information than was linguistically expressed, and that therefore a full linguistic description of the sentence cannot adequately characterize its memory representation. In each of five experiments, listeners recognized or recalled having heard not only sentences that were presented, but also similarly worded inferences derived therefrom. Thus, it is proposed, the inferences must have been embodied in the memory representations of the perceived sentences. These findings are interpreted within a constructive theory of sentence comprehension and memory.
Heat transfer to evaporating refrigerants in two‐phase flow

Flow regimes occurring during evaporation of Freon-12 (dichlorodifluoromethane) and Freon-22 (monochlorodifluoromethane) inside five tubes were investigated. Two flow models are proposed, one each for vertical and horizontal tube orientation. The limits of each flow regime were determined and heat transfer correlations obtained. The most significant flow regimes were found to be nucleate boiling, annular flow, and mist flow. A correlation for the transition between annular flow and mist flow was obtained.
Compendium of recurrent selection methods and their application

Recurrent selection is a breeding method that has been used for the genetic improvement of germplasm. Although recurrent selection methods were suggested over 40 years ago, there use has not been as extensive as the other classical plant breeding methods. Recurrent selection is used for the improvement of traits inherited in a quantitative manner, and the primary objective of the method is to gradually increase the frequency of favorable alieles and maintain genetic variability for future selection. Different methods of recurrent selection have been suggested, depending on the types of gene action considered important in the inheritance of the traits under selection, relative efficiency of selection, and the complexity of the trait under selection. Most methods of recurrent selection include three phases conducted in a repetitive manner; development of progenies, evaluation of progenies in replicated trials, and recombination of the superior progenies based on the evaluation trials. Most information sugge...
A direct Newton solver for the two-dimensional tokamak edge plasma fluid equations

Newton's method, finite volume discretization, and a staggered grid are used to compute the steady state profiles of the two-dimensional two-fluid Tokamak edge plasma fluid equations. In this set of fluid equations, the transport coefficients are highly nonlinear functions of the dependent variables, and mass and energy transfer due to atomic reactions is included. The techniques of an adaptive damped iteration, mesh sequencing, and reduced factorization are combined to increase the radius of convergence and to accelerate convergence. These techniques are illustrated through a model problem.
Continuing the means-ends discussion from the history of science.

The editor of this section invited me to reflect on clinical and laboratory relationships in a different way, freeing me from the usual considerations of specific procedures, molecules, tests, or pathophysiologic applications. I reluctantly accepted, and now invite the reader to share my ruminations of another kind, but a kind that I feel should inhabit the intellectual milieu of every scientist and clinician. When asked about myself, I have responded with many kinds of self-identification, but have never said "I am a scientist." Someone might judge me in error, arguing that "you have studied sciences; you have published articles that some might describe as scientific; you critique the science of others; you teach and practice dermatology using the vocabulary, insights, and tools of science and scientific work; how then are you not a scientist?" My answer would insist, gently, that No, I am primarily a user of science and one
Modifying speed of group decision making without awareness of group members

Contingent reinforcement successfully modified speed of decision making by two-person groups. Depending on the reinforcement contingency, groups either increased or decreased decision time relative to control groups given noncontingent reinforcement on matching schedules. As far as could be determined from post-experimental questionnaires and interviews, none of the Ss had insight into the reinforcement contingency. The results suggest that the basic operant conditioning paradigm may be applicable to the modification of interdependent behavior patterns in free-responding groups even though the members of the group are unaware that they are adjusting their interaction patterns to fit the external situation.