cssi/SciSciGPT-SciSciNet huggingface dataset:
Sildenafil Improves Small Artery Elasticity in Heart Transplant Recipients

Purpose Small artery elasticity (SAE) derived from radial artery pulse wave contour analysis is a measurement of endothelial function and a predictor of cardiovascular events in the general population. We have previously shown that SAE is reduced in heart transplant recipients (HTR) and is associated with cardiac allograft vasculopathy. In this study, we evaluated the effect of sildenafil on SAE in HTR. Methods and Materials We enrolled 11 stable HTR without recent history of rejection, infection, renal disease or CAV. SAE was measured prior to and one hour after administration of 50mg of oral sildenafil. Paired sample t-test was performed to compare SAE pre- and post-sildenafil. Results Median age was 62 yrs (range 44-72), 88% were male, median duration of transplant was 1 yr (range 1-3), and mean BMI was 26.5 ±3.72 kg/m2. 66% had prior ischemic cardiomyopathy. Mean baseline SAE was 3.7±1.1 ml/mmHgX10. One hour following administration of sildenafil, SAE increased significantly by 38% on average. The mean SAE after sildenafil was 5.2±2.3 ml/mmHgX10 (p= 0.032). [ figure 1 ] Conclusions Acute sildenafil treatment improves small artery elasticity in heart transplant recipients. Further studies are warranted to determine whether modification of endothelial function has clinical implications in heart transplant recipients.
Primary lung cancer producing α-fetoprotein

Reports of alpha-fetoprotein-producing lung tumors are rare. Only 24 such patients with these tumors have been previously studied. We report the case of a patient with a large cell carcinoma of the lung and a serum alpha-fetoprotein level of 9,300 ng/mL, with no evidence of hepatic or other systemic abnormalities. Serum levels of alpha-fetoprotein returned to normal postoperatively.
The regressive nature of civil penalties

FfC Bureau of Economics working papers are preliminary materials circulated to stimulate discussion and critical comment All data contained in them are in the public domain. This includes information obtained by the Commission which has become part of public record. The analyses and conclusions set forth are those of the authors and do not necessarily reflect the views of other members of the Bureau of Economics, other Commission staff, or the Commission itself. Upon reques single copies of the paper will be provided. References in public ations to FTC Bureau of Economics working papers by FrC economists (other than acknowledgement by a writer that he has access to such unpublished materials) should be cleared with the author to protect the tentative character of these papers.
Relation between age, education, and time to respond to questions in a computer-based medical interview

The time required for 458 women volunteers to respond to questions in a computer-based medical interview was related both to their age and to their formal education. When the analysis was restricted to the 220 women with a college degree, older women responded more slowly than their younger counterparts, and when the analysis was restricted to the 265 women between 18 and 30 years of age, women with less formal education took longer to respond. By contrast, the time required for the volunteers to record their responses was related only to age.
Data quality assurance and performance measurement of data mining for preventive maintenance of power grid

Ensuring reliability as the electrical grid morphs into the "smart grid" will require innovations in how we assess the state of the grid, for the purpose of proactive maintenance, rather than reactive maintenance; in the future, we will not only react to failures, but also try to anticipate and avoid them using predictive modeling (machine learning and data mining) techniques. To help in meeting this challenge, we present the Neutral Online Visualization-aided Autonomic evaluation framework (NOVA) for evaluating machine learning and data mining algorithms for preventive maintenance on the electrical grid. NOVA has three stages provided through a unified user interface: evaluation of input data quality, evaluation of machine learning and data mining results, and evaluation of the reliability improvement of the power grid. A prototype version of NOVA has been deployed for the power grid in New York City, and it is able to evaluate machine learning and data mining systems effectively and efficiently.
Photostable single-molecule nanoparticle optical biosensors for real-time sensing of single cytokine molecules and their binding reactions.

We synthesized tiny stable silver nanoparticles (2.6 ± 1.1 nm) and used its small surface area and functional groups to control single molecule detection (SMD) volumes on single nanoparticles. These new approaches allowed us to develop intrinsic single molecule nanoparticle optical biosensors (SMNOBS) for sensing and imaging of single human cytokine molecules, recombinant human tumor necrosis factor-α (TNFα), and probing its binding reaction with single monoclonal antibody (MAB) molecules in real-time. We found that SMNOBS retained their biological activity over months and showed exceptionally high photostability. Our study illustrated that smaller nanoparticles exhibited higher dependence of optical properties on surface functional groups, making it a much more sensitive biosensor. Localized surface plasmon resonance spectra (LSPRS) of SMNOBS showed a large red shift of peak wavelength of 29 ± 11 nm, as single TNFα molecules bound with single MAB molecules on single nanoparticles. Utilizing its LSPRS, we...
Food Safety and Sanitation in Hospitality Operations: Students' Perspectives

For six semesters, attitudes about food safety held by students in a sanitation course at one university (N = 229) were assessed. Types of food safety training received were identified. Attitudes were positive with overall semester's mean ratings to ten attitude statements (alpha reliability of 0.79) ranging from 4.0 to 5.0 on a 5.0 scale (5=Strongly Agree). The majority of students reported work experience in foodservice but only about half indicated food safety training had been received. Training was provided most frequently in quick service and institutional foodservices. Over the study's three-year period, no increase in food safety training was noted.
Change detection and classification of land cover in multispectral satellite imagery using clustering of sparse approximations (CoSA) over learned feature dictionaries

Neuromimetic machine vision and pattern recognition algorithms are of great interest for landscape characterization and change detection in satellite imagery in support of global climate change science and modeling. We present results from an ongoing effort to extend machine vision methods to the environmental sciences, using adaptive sparse signal processing combined with machine learning. A Hebbian learning rule is used to build multispectral, multiresolution dictionaries from regional satellite normalized band difference index data. Land cover labels are automatically generated via our CoSA algorithm: Clustering of Sparse Approximations, using a clustering distance metric that combines spectral and spatial textural characteristics to help separate geologic, vegetative, and hydrologie features. We demonstrate our method on example Worldview-2 satellite images of an Arctic region, and use CoSA labels to detect seasonal surface changes. Our results suggest that neuroscience-based models are a promising approach to practical pattern recognition and change detection problems in remote sensing.
Measurements of friction and adhesion for alkyl monolayers on Si(111) by scanning force microscopy

In this study, quantitative nanoscale frictional and pull-off forces were measured by scanning force microscopy for various C12 alkyl monolayers with different terminal groups ranging from hydrophobic (terminated by −CH3) to hydrophilic (terminated by −COOH) on atomically flat Si(111) surfaces at a variety of relative humidities. These monolayers were prepared and characterized by techniques such as scanning probe microscopy, contact angle goniometry, and X-ray photoelectron spectroscopy. The magnitude of the frictional force was found to decrease in the order SiO2/Si > −COOHSi > −COOCH3,Si > −CH3,Si ∼ −CH3,Au. On comparison to the native oxide silicon surface, the friction coefficient decreases dramatically when the surface is coated with different monolayers: by 20 times for hydrophobic monolayers and by 3 times for hydrophilic monolayers. Pull-off forces are generally larger for hydrophilic than for hydrophobic surfaces. For hydrophobic surfaces, frictional and pull-off forces are not sensitive to rel...
A small, Fast-Response Probe to Measure Composition of a Binary Gas Mixture

A probe to measure the concentration of the components in a binary mixture of gases is described. The probe is simple to construct and quite rugged. It samples from a very small volume, has a fast time response and can very easily detect 1% of helium in nitrogen. The explanation of the principle of operation is a good example of the power of dimensional analysis when applied to what may seem to be quite a complicated and unfamiliar problem. The analysis suggest several experiments which in turn lead to a more detailed understanding of the probe and improvements in its design.
How Investor Relations Contributes to the Corporate Bottom Line

Investor relations officers say that one of the biggest challenges of their work is proving to the senior management that investor relations contributes value to the organization. This study provides an initial step in evaluating investor relations' contribution to an organization's bottom line. The study first offers a theoretical overview of academic and professional literature dealing with the contribution of investor relations to the organizational bottom line. Second this theoretical overview serves as a starting point for an empirical investigation organized as a Delphi panel. Investor relations officers from corporations and investor relations agencies were recruited to participate in the panel and share their practical insights in response to the theoretically identified indicators of investor relations value. As a result, the study found 4 key areas of investor relations contribution: fair share price, improved liquidity of stock, enhanced analyst coverage, and building and maintaining investor r...
BENIGN AND MALIGNANT PEDIATRIC SCROTAL MASSES

The discovery of a scrotal mass by a parent, physician, or young patient can be an emotionally alarming event. The treating physician is confronted with a staggering list of possibilities as to the origin and cause of the mass (Table 1) . In the infant it may be a simple hydrocele, in the adolescent a varicocele or a testicular neoplasm. The key to solving the diagnostic dilemma is a systematic approach based on presence of symptoms, location of the mass, physical findings, and an understanding of the anatomic contents of the spermatic cord and scrotum. The clinical presentation of a painful scrotal mass requires immediate action because torsion of the spermatic cord is a urologic emergency. The clinical dictum that a painful scrotal mass is torsion until proven otherwise should be heeded. Other painful scrotal lesions include orchitis, epididymitis, torsion of appendix testis or appendix epididymis, acute bleeding into a testicular tumor, trauma, and incarcerated hernia. The diagnosis, evaluation, and treatment of painful scrotal masses is covered in detail in the article by Kass and Lundak. The child or adolescent with a painless scrotal mass may have a life-threatening testicular neoplasm. The most important step is to establish the exact location of the lesion (Fig. 1) . An intratesticular lesion should be considered a malignancy unless proven otherwise. When the results of the physical examination, including transillumination, fail to distinguish the exact location of the lesion, then scrotal sonography is of great value, especially when the testis is not palpable and a hydrocele is present. Scrotal sonography localizes the lesion and distinguishes a solid from a cystic mass. 5 It can be extremely helpful in detecting small lesions within the testis, but its findings are not specific and by itself cannot exclude malignancy. 29 Consequently, sonography has not altered the surgical approach to a painless testicular mass in adults or children.
Contribution of baroreflex sensitivity and vascular reactivity to variable haemodynamic responses to cocaine in conscious rats.

SUMMARY 1. Baroreflex function is critical for short-term arterial pressure regulation and decreased baroreflex responsivity may predict a predisposition to hypertension and sudden cardiac death. In the present study, we assessed whether baroreflex sensitivity (BRS) and/or vascular reactivity covary with haemodynamic responsiveness to cocaine in vascular and mixed responders. 2. We assessed the heart rate index of BRS in resting animals. We examined dose–response relationships to pressor and depressor agents to determine cardiovascular reactivity. Subsequently, rats were given cocaine (5 mg/kg, i.v.) to classify them as vascular or mixed responders. Vascular responders (n = 16) were defined as those rats with a substantial (> 8%) decrease in cardiac output in response to cocaine owing to a larger increase in systemic vascular resistance. The remaining rats (n = 8) were mixed responders because they had smaller increases in vascular resistance and little change or an increase in cardiac output. 3. The BRS determined with angiotensin (Ang) II, but not with phenylephrine, was impaired in mixed responders compared with vascular responders. At equipressor doses, there were significantly greater reductions in cardiac output in vascular responders compared with mixed responders in response to phenylephrine or AngII. Methacholine produced greater decreases in heart rate in vascular responders, suggesting greater muscarinic responsivity. 4. We conclude that differences in vascular reactivity to AngII may contribute to differences in haemodynamic response profiles to cocaine in individual rats. More importantly, the differences in vascular responsivity and BRS do not appear to be primary determinants of haemodynamic response variability.
Molecular and isotopic records of C4 grassland expansion in the late miocene

Abstract Siwalik paleosol and Bengal Fan sediment samples were analyzed for the abundance and isotopic composition ofn-alkanes in order to test for molecular evidence of the expansion of C4 grasslands on the Indian subcontinent. The carbon isotopic compositions of high-molecular-weight alkanes in both the ancient soils and sediments record a shift from low δ13C values (ca. −30‰) to higher values (ca. −22‰) prior to 6 Ma. This shift is similar in magnitude to that recorded by paleosol carbonate and fossil teeth, and is consistent with a relatively rapid transition from dominantly C3 vegetation to an ecosystem dominated by C4 plants typical of semi-arid grasslands. The n-alkane values from our paleosol samples indicate that the isotopic change began as early as 9 Ma, reflecting either a growing contribution of C4 plants to a dominantly C3 biomass or a decrease in water availability to C3 plants. Molecular and isotopic analyses of other compounds, including n-alcohols and low-molecular weightn-alkanes indicate paleosol organic matter contains contributions from a mixture of sources, including vascular plants, algae and/or cyanobacteria and microorganisms. A range of inputs is likewise reflected in the isotopic composition of the total organic carbon from these samples. In addition, then-alkanes from two samples show little evidence for pedegenic inputs and we suggest the compounds were derived instead from the paleosol’s parent materials. We suggest the record of vegetation in ancient terrestrial ecosystems is better reconstructed using isotopic signatures of molecular markers, rather than bulk organic carbon. This approach provides a means of expanding the spatial and temporal records of C4 plant biomass which will help to resolve possible tectonic, climatic or biological controls on the rise of this important component of the terrestrial biosphere.
Detection and molecular characterization of enteric viruses from poult enteritis syndrome in turkeys

ABSTRACT This study was conducted to detect and characterize enteric viruses [rotavirus, turkey astrovirus-2 (TAstV-2), reovirus, and turkey coronavirus] from cases of poult enteritis syndrome (PES) in Minnesota turkeys. Of the intestinal contents collected from 43 PES cases, 25 were positive for rotavirus and 13 for small round viruses by electron microscopy (EM). Of the enteric virus-positive cases by EM (n = 27), 16 cases had rotavirus or small round viruses alone and the remaining 11 cases had both viruses. None of the cases were positive for reovirus or coronavirus by EM. However, with reverse transcription-PCR (RT-PCR), 40 cases (93%) were positive for rotavirus, 36 (84%) for TAstV-2, and 17 (40%) for reovirus. None of the cases were positive for turkey coronavirus by RT-PCR. The viruses from all cases were detected either alone or in combination of 2 or 3 by RT-PCR. Thus, 8 (19%) cases were positive for a single virus, whereas a combination of viruses was detected in the remaining 35 (81%) cases. The rota-TAstV-2 combination was the most predominant (n = 18 cases). Fifteen cases were positive for all 3 viruses. The rotaviruses had sequence homology of 89.8 to 100% with previously published sequences of turkey rotaviruses at the nucleotide level. The TAstV-2 had sequence homology of 84.6 to 98.7% with previously published TAstV-2, whereas reoviruses had sequence homology of 91.6 to 99.3% with previously published sequences of turkey reoviruses. Phylogenetic analysis revealed that rota- and reoviruses clustered in a single group, whereas TAstV-2 clustered in 2 different groups. In conclusion, a larger number of PES cases was positive for rotavirus, TAstV-2, and reovirus by RT-PCR than with EM. The presence of more than one virus and changes at the genetic level in a virus may affect the severity of PES in turkey flocks.
Sequence of the putative LDL receptor binding regions of apolipoprotein B in mouse and hamster

Abstract The figures printed in our original publication have some errors, generated during computer alignment of the nt and aa sequences. The revised figures are presented here. The nt sequence corresponds to nt 8297-10647 in the human apoB cDNA. These changes do not alter any of the findings in the original publication.
A weak estimate of the fractal dimension of the Mandelbrot boundary

Abstract A technique to compute fractal dimension as defined by the Kolmogorov capacity is discussed. The method is used to compute fractal dimension for several standard curves and the boundary of the Mandelbrot set. This estimate of fractal dimension, although very rough, refutes Milnor's conjecture that the Hausdorff dimension of the Mandelbrot boundary is 2.
Antecedent event influence on benthic marine algal standing crops in Hawaii

Abstract In non-monsoonal tropical areas, such as Hawaii, the somewhat random effects of storm waves may be the most influential environmental factors regulating the size of the harvestable frondose marine algal crop. Seasonal factors, such as light and temperature, seem to be less important as judged by regression and correlation analysis. With increasing time prior to the measurement of standing crop, the influence of light steadily decreased, that of storm waves increased to within three weeks before the sampling period after which it decreased, while the effect of temperature increased throughout.
Unsupervised statistical segmentation of multispectral volumetric MRI images

This work presents a reliable automatic segmentation algorithm for multispectral MRI data sets. We propose the use of an automatic statistical region growing algorithm based on a robust estimation of local region mean and variance for every voxel on the image. The best region growing parameters are automatically found via the minimization of a cost functional. Furthermore, we propose a hierarchical use of relaxation labeling, region splitting, and constrained region merging to improve the quality of the MRI segmentation. We applied this approach to the segmentation of MRI images of anatomically complex structures which suffer signal fading and noise degradations.
The Porcine Ovarian Follicle. VI. Comparison of Fatty Acid Composition of Serum and Follicular Fluid at Different Developmental Stages

The free and esterified fatty acid composition of pig serum and pig ovarian follicular fluid (POFF) samples were determined at three different developmental stages of the follicle. The most striking difference between pig serum and POFF was that the contents of free arachidonic (20:4 w6) and free docosatetraenoic (22:4 w6) acids were â€˜?�\i4 times higher in POFF than in serum. The high content of 20:4 @6 in POFF may relate to the synthesis of prostaglandins. Free fatty acid (FFA) concentrations in POFF also decreased with follicular maturation. The concentration of POFF-FFA from large sized follicles was similar to that of pig serum. Variations in the esterified fatty acid profile with respect to follicle development were particularly noticeable in the phos phatidylchohine fraction. The decrease of palmitic (16:0) and oleic (18:1) acids and the increase of stearic (18:0) acid and polyunsaturated fatty acids (mainly 20:4 c6) in ovarian fluid as follicles increased in size from 6 mm suggest that fatty acid chain elongation and desaturation increase with follicular maturation.
Capping volcanic rocks: West central Nevada

Cenozoic capping volcanic rocks in the Nevada portion of the Basin and Range Province of the western United States belong to the high alumina calcalkaline igneous series. Varying proportions of plagioclase (An=85 to 45 percent), pyroxene (augite, pigeonite, and hypersthene), olivine, magnetite, biotite, and oxyhornblende indicate a modal range from olivine basalt to andesite.
To Scale or Not to Scale Seismic Ground-Acceleration Records

Current estimates of seismic structural fragilities are commonly made on the basis of finite collections of actual or virtual ground-acceleration records that are scaled to have the same scalar intensity measure, for example, peak ground acceleration or pseudospectral acceleration. This paper models seismic ground-acceleration records by samples of Gaussian processes X(t) and constructs scaled versions X˜(t) of X(t) by following current procedures. This analysis shows that X˜(t) and X(t) have different probability laws, so that fragilities on the basis of X˜(t) provide limited if any information on the seismic performance of structural systems, that is, fragilities on the basis of X(t). The usefulness of current fragility estimates on the basis of scaled seismic ground-acceleration records is questionable, and scaling ground motions is not recommended.
The Effects of Writing Therapy in Comparison to EMD/R on Traumatic Stress: The Relationship Between Hypnotizability and Client Expectancy to Outcome

Many psychologists encourage clients to engage in journal writing to supplement individual psychotherapy. Empirical evidence supports the use of writing when targeted at traumatic memories. The most thoroughly researched writing strategy, developed by J. Pennebaker (1989), suggests that writing is most effective when it targets a specific memory along with the emotional components of that memory. Effective writing therapy is thus procedurally similar to effective exposure therapy for fear and traumatic memories. This investigation examined structured writing as a self-contained treatment by comparing it to eye movement desensitization and reprocessing, and it was found to be effective.
Inhibition of SN-38 glucuronidation by ketoconazole

Background/Aims Ketoconazole has been shown to inhibit the glucuronidation of the UGT2B7 substrates AZT and lorazepam. Its effect on UGT1A substrates is unknown. A recent study (Kehrer et al, JClin Oncol, 2002) found that co-administration of irinotecan and ketoconazole led to a significant increase in the formation of SN-38. This study investigates whether ketoconazole contributes to the increase in SN-38 formation by inhibiting SN-38 glucuronidation. Methods SN-38 glucuronidation activities were determined by measuring the rate of SN-38 glucuronide (SN-38G) formation using pooled human liver microsomes (HLM) and cDNA transfected UGT1A isoforms (1A1, 1A3, 1A4, 1A6, 1A7, 1A8, 1A9) in the presence of ketoconazole. Indinavir, a known UGT1A1 inhibitor, was used as a positive control. SN-38G formation was measured by HPLC. Results A 20% reduction in SN-38G formation was observed after incubation of HLM with SN-38 and ketoconazole at 10 μM (p=0.001). Among the UGT1A isoforms screened, ketoconazole showed the highest inhibitory effect on UGT1A1 and UGT1A9, reducing SN-38 glucuronidation activities by 59% and 32% (p<0.05), respectively. The IC50 values (using UGT1A1 and UGT1A9) were 8.8 μM and 6.3 μM for ketoconazole, respectively. Conclusion These results suggest that ketoconazole is a potent UGT1A1 and UGT1A9 inhibitor. Further work is currently being undertaken to establish the possible mechanism of ketoconazole-mediated inhibition of SN-38 glucuronidation. Clinical Pharmacology & Therapeutics (2005) 77, P75–P75; doi: 10.1016/j.clpt.2004.12.176
A novel CDK5-dependent pathway for regulating GSK3 activity and kinesin-driven motility in neurons

Neuronal transmission of information requires polarized distribution of membrane proteins within axonal compartments. Membrane proteins are synthesized and packaged in membrane-bounded organelles (MBOs) in neuronal cell bodies and later transported to axons by microtubule-dependent motor proteins. Molecular mechanisms underlying targeted delivery of MBOs to discrete axonal subdomains (i.e. nodes of Ranvier or presynaptic terminals) are poorly understood, but regulatory pathways for microtubule motors may be an essential step. In this work, pharmacological, biochemical and in vivo experiments define a novel regulatory pathway for kinesin-driven motility in axons. This pathway involves enzymatic activities of cyclin-dependent kinase 5 (CDK5), protein phosphatase 1 (PP1) and glycogen synthase kinase-3 (GSK3). Inhibition of CDK5 activity in axons leads to activation of GSK3 by PP1, phosphorylation of kinesin light chains by GSK3 and detachment of kinesin from transported cargoes. We propose that regulating the activity and localization of components in this pathway allows nerve cells to target organelle delivery to specific subcellular compartments. Implications of these findings for pathogenesis of neurodegenerative diseases such as Alzheimer's disease are discussed.
Electronic structure of doped Sr2VO4

Abstract We report band structure calculations for the compound Sr 2 VO 4 . Calculations were also performed for the hypothetical compound, Tl 2 VO 4 , in the K 2 NiF 4 structure in order to determine the valence of substitutional Tl in Sr 2 VO 4 . For pure Sr 2 VO 4 we find a Stoner criterion, N ( E F ) I ( E F ), of 2.21 implying a magnetic instability. This is consistent with the antiferromagnetic state found. experimentally. Rigid band calculations of the Stoner criterion indicate that the magnetic instability of Sr 2 VO 4 may be removed by doping with either monovalent or trivalent ions the Sr sites. However, much smaller concentrations are required if monovalent dopants are used. The calculations for Tl 2 VO 4 show that substitutional Tl is effectively monovalent on the Sr site and thus provides an alternative to doping with group I elements. We have evaluate the electron-phonon interaction parameters η and find that they have much larger values than in La 2 CuO 4 .
Optimizing the simultaneous management of blood pressure and cholesterol for type 2 diabetes patients

Abstract We present a Markov decision process (MDP) model to determine the optimal timing of blood pressure and cholesterol medications. We study the use of our model for a high-risk population of patients with type 2 diabetes; however, the model and methods we present are applicable to the general population. We compare the optimal policies based on our MDP to published guidelines for initiation of blood pressure and cholesterol medications over the course of a patient’s lifetime. We also present a bicriteria analysis that illustrates the trade off between quality-adjusted life years and costs of treatment.
A comparison of compressive strengths of six cavity base materials

W hen choosing a cavity base it is necessary to consider the ability of the material to withstand the force of mastication and the pressure of insertion of the restoration. Studies have suggested that the minimum compressive strength required to support the insertion of a restoration is 100 to 170 psi.’ The newer calcium hydroxide bases and zinc oxide-eugenol materials have been found to withstand the force of condensation of direct gold.2 Several new or reformulated commercial calcium hydroxide products have become available for use as a cavity base. These products are NuCap (Coe Laboratories, Inc., Chicago, Ill.), Life Fast Set (Kerr/ Sybron, Romulus, Mich.), and Dycal Advanced Formula II (L.D. Caulk Co., Division of Dentsply International Inc., Milford, Del.). Some dentists prefer to use a zinc oxide-eugenol material for a cavity base. Cavitec (Kerr/ Sybron) and IRM (L.D. Caulk Co.) products were selected to be representatives of this type of base. Zinc phosphate cement has been used as a standard for comparing strengths of cement bases. Fleck’s (Mizzy, Inc., Clifton Forge, Va.) cement was chosen because it is the most popular commercially available product of this type.* Table I. Compressive strengths of six products at 7-minute and 24-hour periods
Difference in Calcium Requirements for Forskolin-Induced Release of Prolactin from Normal Pituitary Cells and GH4C1 Cells in Culture

We investigated the role of Ca++ in cAMPstimulated PRL release from 1) primary cultures of male rat pituitary glands, 2) primary cultures of estrogen-induced pituitary tumors from Fischer rats, and 3) the pituitary tumor cell line GH4C1. Forskolin, an activator of adenylate cyclase, increased intracellular cAMP concentrations in GH4C1 cells at least 20-fold within 15 min. This increase occurred in the presence or absence of added extracellular Ca++ or in the presence of D600 or Co++. Forskolin increased PRL release from the three types of cells. The three systems differed in the Ca++ sensitivity of forskolin-induced release, but showed little difference in the Ca++ sensitivity of K+-induced release. This was shown in two ways. The cells were incubated either 1) in a medium without added Ca++ or 2) in the presence of a Ca++ channel inhibitor, D600. In normal cells, K+- and forskolin-induced release were equally inhibited when extracellular Ca++ was removed or D600 was added. In GH4C1 cells, Ca++ removal or...
Membership Size, Communication Activity, and Sustainability: A Resource-Based Model of Online Social Structures

As telecommunication networks become more common, there is an increasing interest in the factors underlying the development of online social structures. It has been proposed that these structures are new forms of organizing which are not subject to the same constraints as traditional social structures. However, from anecdotal evidence and case studies it is difficult to evaluate whether online social structures are subject to the same problems as traditional social structures. Drawing from prior studies of traditional social structures and empirical analyses of longitudinal data from a sample of Internet-based groups, this exploratory work considers the role of size and communication activity in sustainable online social structures.A resource-based theory of sustainable social structures is presented. Members contribute time, energy, and other resources, enabling a social structure to provide benefits for individuals. These benefits, which include information, influence, and social support, are the basis for a social structure's ability to attract and retain members. This model focuses on the system of opposing forces that link membership size as a component of resource availability and communication activity as an aspect of benefit provision to the sustainability of an online social structure. Analyses of data from a random sample of e-mail-based Internet social structures (listservs) indicate that communication activity and size have both positive and negative effects on a structure's sustainability. These results suggest that while the use of networked communication technologies may alter the form of communication, balancing the opposing impacts of membership size and communication activity in order to maintain resource availability and provide benefits for current members remains a fundamental problem underlying the development of sustainable online social structures.
Volcano still poses threat

After 6 months of activity, Mount St. Helens still poses potential hazards to the surrounding region, according to a recent report from the U.S. Geological Survey. Among the hazards that remain are explosive lateral and vertical eruptions, flows of hot pyroclastic rock debris, and floods and mudflows triggered by heavy precipitation. Most explosive eruptions probably will be preceded by several hours of earthquake and other seismic activity, say USGS hazard coordinators Dwight R. Crandell and Donal R. Mullineaux. It is possible, however, for eruptions to begin with little or no warning, they caution. Seismic activity would allow time for issuing some warnings to the surrounding populace.
Flow routing for variable bit rate source nodes in energy-constrained wireless sensor networks

We consider a two-tier wireless sensor network and focus on the flow routing problem for the upper tier aggregation and forwarding nodes (AFNs). Assuming each AFN is equipped with directional antennas for transmission, we are interested in how to perform flow routing at each node such that the network lifetime is maximized. We present a flow routing algorithm that provably has the following properties: (1) when the average source rate of each AFN is known a priori, the flow routing algorithm is optimal and gives maximum network lifetime performance; (2) when the average source rate of each AFN is unknown but is within a fraction, /spl epsiv/, of an estimated rate value, then the network lifetime given by the proposed flow routing algorithm is no more than 2/spl epsiv//(1-/spl epsiv/) from optimal. As a result, the proposed flow routing algorithm can provide predictable lifetime performance, even when the source bit rate can be time-varying.
Differential expression of placental villous angiopoietin-1 and -2 during early, mid and late baboon pregnancy.

Although vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and Ang-2 have important roles in angiogenesis, very little is known about the regulation of these factors in the villous placenta during human pregnancy. In the present study, to investigate whether placental expression of Ang-1, Ang-2 and VEGF was altered in a cell-specific manner with advancing baboon gestation, the mRNA levels of these growth factors were determined by RT-PCR in cells isolated by Percoll gradient centrifugation from and protein localization assessed by immunocytochemistry in the villous placenta at early (day 60), mid (day 100) and late (day 170, term is 184 days) baboon gestation. Mean (± SE) Ang-1 mRNA levels, relative to 18S rRNA, in villous syncytiotrophoblast (3.92 ± 0.68) and cytotrophoblast (1.31 ± 0.31) cell fractions were highest on day 60 of gestation, then decreased by approximately 2.5-fold (P<0.05) to 1.39 ± 0.29 and 0.49 ±0.07, respectively, on day 170. Moreover, Ang-1 mRNA levels in the villous stromal cells and Ang-2 mRNA levels in all placental villous cell fractions were similar on days 60, 100, and 170 of gestation. In contrast to Ang-1 and Ang-2, placental villous cytotrophoblast VEGF mRNA levels were increased 2.94 fold (P<0.05) between mid (0.67 ± 0.15) and late (1.97 ± 0.49) gestation. A corresponding decrease in Ang-1, absence of change in Ang-2, and increase in VEGF protein immunocytochemical expression were exhibited in placental trophoblast with advancing baboon pregnancy. Ang-1/-2 and the angiopoietin Tie-2 receptor were expressed in vascular endothelial cells of the villous placenta, indicating that these blood vessel cells are a major site of ligand-receptor interaction for angiogenesis during primate pregnancy. We conclude that there is a cell-specific differential change in placental villous trophoblast expression of VEGF, Ang-1, and Ang-2 which we propose is important in regulating angiogenesis in the villous placenta during primate pregnancy.
Complementation and chief factors in finite groups

(1997). Complementation and chief factors in finite groups. Communications in Algebra: Vol. 25, No. 2, pp. 381-400.
Spreadsheets for physics

Modern spreadsheet programs can provide a remarkable capability for quick and easy solutions to a broad range of small—and possibly large—physics, engineering, and astronomy problems. This usage can go far beyond the original applications of spreadsheets as accounting aids. However, sharp instruments can cut both ways, and these programs can be dangerous to the unwary user in providing quick and pretty collections of incorrect answers. Several spreadsheet techniques are shown by example; advantages and drawbacks are discussed.
Effects of ethanol and acetaldehyde on reactive oxygen species production in rat hepatic stellate cells.

Background: Alcoholism is a common cause of cirrhosis. Hepatic stellate cells are the main source of collagen that ultimately leads to hepatic fibrosis and cirrhosis. Reactive oxygen species (ROS) enhance stellate cell activation and stimulate fibrogenesis. In this study, the acute effects of ethanol (ET) and acetaldehyde (AC) were determined on the production of ROS in isolated rat hepatic stellate cells. Methods: Rat stellate cells were isolated in situ by perfusion of the portal vein and cultured. Hydrogen peroxide (H 2 O 2 ) was determined by luminol-derived chemiluminescence (CL), while superoxide anion (O • 2 -) production was assessed by the fluorescent probe hydroethidine. Results: AC increased the formation of H 2O 2 and O • 2 -, and these effects were first detectable at AC concentrations of 5 and 10 μM, respectively, reaching a maximum at 50 to 75 μM. Reduction of glutathione (GSH) synthesis by 1-buthionine sulfoximide (BSO) or by GSH conjugation with dimethylmaleate (DEM) further enhanced the effects of AC on H 2 O 2 and O • 2 - formation, while N-acetylcysteine (NAC) decreased H 2 O 2 and eliminated the enhanced generation of O • 2 - caused by AC. Raloxifene, which inhibits O • 2 - production by NAD(P)H oxidase, reduced the effects of AC on H 2 O 2 and O • 2 - production. ET increased H 2 O 2 or O • 2 only in the presence of BSO or DEM. Conclusions: This study shows that concentrations of AC, which occur in vivo after the ingestion of alcoholic beverages, result in the formation of ROS in rat hepatic stellate cells. The increases in ROS are known to activate stellate cells promoting fibrogenesis.
Antipsychotic medications, glutamate, and cell death: A hidden, but common medication side effect?

We hypothesize the interaction between antipsychotic medications and regulation of extracellular glutamate which has gone largely unnoticed in the medical community has significant clinical importance. Typical antipsychotic medications such as haloperidol elevate extracellular glutamate because they exert antagonist effects on dopamine D2 and serotonin 5HT1A receptors. In contrast, serotonin 5HT2A receptor antagonists inhibit glutamate release. Glutamate is potentially excitotoxic through effects on ionotropic receptor channels and may exert synergistic effects with other neurotoxic pathways. In contrast to typical antipsychotic drugs, pharmacological properties of atypical antipsychotic medications at dopamine D2, serotonin 5HT1A and 5HT2A receptors limit extracellular glutamate and may theoretically be neuroprotective in certain clinical settings. In this review we discuss three common clinical settings in which typical antipsychotic medications may potentiate neurotoxicity by elevating extracellular glutamate. The most common clinical setting, hypoglycemia during combined use of antipsychotic medications and insulin, presents a theoretical risk for 35 million diabetic patients worldwide using antipsychotic medications. Antipsychotic medication treatment during hypoxic episodes in the intensive care unit and following traumatic brain injury are two other common clinical settings in which this interaction poses theoretical risk. Further study is needed to test hypothesized risk mechanisms, and determine clinical and epidemiological consequences of these exposures. 2012 Published by Elsevier Ltd.
A direct solution for the efficiency and gain of a CARM oscillator

Approximate analytic solutions for the resonant interaction of a relativistic electron beam interacting with a constant amplitude TEM wave, as in the cyclotron autoresonance maser (CARM) oscillator configuration, are presented. The approximation neglects force bunching relative to inertial bunching, which is usually valid for CARM parameter values of interest in many applications. >
Biological relations of Egyptian and eastern Mediterranean populations during Pre-dynastic and Dynastic times

Abstract During the migrations and population increases and decline in health accompanying the Eighth-Sixth millennia B.C. farming revolution spread of the new mutant falciparum malaria from Greece and Italy crossed the flow of genes from Africa northward, as indicated by porotic hyperostosis increase (abnormal hemoglobins and anemia) and Negroid traits (nose breadth, prognathism). Disease selection shaped slightly Negroid and paedomorphic Dynastic Upper Egyptians. Lower Egyptians share Eastern Mediterranean traits and population growth and communication steadily lessens contrast between groups down to the XXX Dynasty.
Finding finite-time invariant manifolds in two-dimensional velocity fields

For two-dimensional velocity fields defined on finite time intervals, we derive an analytic condition that can be used to determine numerically the location of uniformly hyperbolic trajectories. The conditions of our main theorem will be satisfied for typical velocity fields in fluid dynamics where the deformation rate of coherent structures is slower than individual particle speeds. We also propose and test a simple numerical algorithm that isolates uniformly finite-time hyperbolic sets in such velocity fields. Uniformly hyperbolic sets serve as the key building blocks of Lagrangian mixing geometry in applications.
Estimation of Dynamic Panel Data Sample Selection Models

This paper considers the problem of identification and estimation in panel data sample selection models with a binary selection rule, when the latent equations contain strictly exogenous variables, lags of the dependent variables, and unobserved individual effects. We derive a set of conditional moment restrictions which are then exploited to construct two-step GMM-type estimators for the parameters of the main equation. In the first step, the unknown parameters of the selection equation are consistently estimated. In the second step, these estimates are used to construct kernel weights in a manner such that the weight that any two-period individual observation receives in the estimation varies inversely with the relative magnitude of the sample selection effect in the two periods. Under appropriate assumptions, these "kernel-weighted" GMM estimators are consistent and asymptotically normal. The finite sample properties of the proposed estimators are investigated in a small Monte-Carlo study.
Visualization of irregular multivariate data

The authors discuss effective techniques for representing scalar and vector valued functions that interpolate to irregularly located data. Special attention is given to the situations where the sampling domain is a two-dimensional plane, 3-D volume, or a closed 3-D surface. The authors first discuss the multiquadric and thin-plate spline methods for interpolating scalar data sampled at arbitrary locations in a plane. Straightforward generalizations are then made to data sampled in 3-D volumetric regions as well as in higher dimensional spaces. The globally defined interpolants can be evaluated on a fine regular grid and they can then be visualized using conventional techniques. Triangular and tetrahedral based visualization techniques are also presented. >
Metabolic response to wind of downy chicks of Arctic-breeding shorebirds (Scolopacidae).

SUMMARY Wind is a significant factor in the thermoregulation of chicks of shorebirds on the Arctic tundra. We investigated the effect of wind at speeds typical of near-surface conditions (0.1-3 ms -1 ) on metabolic heat production, evaporative cooling and thermal conductance of 1- to 3- week-old downy scolopacid chicks (least sandpiper Calidris minutilla; short-billed dowitcher Limnodromus griseus ; whimbrel Numenius phaeopus ). Body mass ranged from 9 to 109 g. To accurately measure the interacting effects of air temperature and wind speed, we used two or more air temperatures between 15° and 30°C that produced cold stress at all wind speeds, but allowed chicks to maintain normal body temperature (approximately 39°C). Thermal conductance increased by 30-50% as wind speed increased from 0.1 to 3 ms -1 . Conductance in these chicks is somewhat lower than that of 1-day-old mallard ducklings of similar mass, but higher than values reported for downy capercaillie and Xantus9 murrelet chicks, as well as for adult shorebirds. Evaporative water loss was substantial and increased with mass and air temperature. We developed a standard operative temperature scale for shorebird chicks. The ratio of evaporative cooling to heat production varied with wind speed and air temperature.
Current status of prognostic profiling in breast cancer.

Breastcancerisaclinicallyheterogeneousdiseasethatcanaffectindividualswithseeminglyidenticalclinicopathologicparametersdifferently.Thisclinicalheterogeneityisdriventoa large extent by abnormal gene expression within tumors. Investigators now have the ability to identify the gene-expression fingerprint of an individual’s tumor. This information maybeusedtorationallydesigntherapeutictargetsinthefuture, and also to predict the clinical course of an individual’s disease, including response to a specific treatment. Genetic profiles of tumors are now being correlated with clinical outcome, and several prognostic and predictive indicators have emerged based on this research. There are at least four commerciallyavailablepredictiveorprognostictests,andseveral more are looming on the horizon. The data gathered from these tests augment standard diagnostic and prognostic information obtained from traditional clinical pathological variables. The advent of gene-profiling technologies started to change the conduct of clinical trials. In the not too distant future, prospective tissue collection for molecular analysis may become routine in order to stratify patients for treatment arms and to optimize treatment strategies based on molecular features of the cancer. Coordinated efforts among oncologists, pathologists, surgeons, laboratory scientists, statisticians, and regulators will be essential in the quest to incorporate genetic profiling and molecular hypotheses into clinical trial planning and conduct.The Oncologist 2008;13:350–360