cssi/SciSciGPT-SciSciNet huggingface dataset:
Mobile phase effects in reversed-phase chromatography : II. Acidic amine phosphate buffers as eluents

In order to meet the particular requirements with regard to the eluent in liquid chromatography of ionogenic substances on non-polar stationary phases, various buffers composed of phosphate and a vicinal diamine having a pKa value in acidic pH domain were examined and characterized by their physico-chemical properties. The heat of ionization for such amines is generally much greater than that of ac idic compounds having commensurable pKa values. Consequently changing temperaturre may strongly affect the degree of ionization of the buffer and as a result the temperature dependence of retention can be drastically altered for certain sample components. This caloric effect of the buffer on retention in reversed-phase chromatography was theoretically treated by taking into account the enthalpies for all processes involved, the constants of the protonic equilibria in solution and the limiting retentiion factors of both the fully ionized and the neutral of the eluite. Thus thermal analysis of a chromatographic system containing a buffer in the eluent and ionogenic solutes by using Van't Hoff plots of chromatographic data may not yield the enthalpy for solute transfer between mobile and stationary phases due to secondary equilibria. Experimental results did not always agree the theoretical predictions. The aberration was attributed to complex formation between sample molecules and buffer species, that is to a hetaeric effect of the buffer. Some dramatic changes were observed in retention behavior with concomitant improvement in peak shape and chromatographhic efficiency upon replacing sodium phosphate by piperazine or tetramethylethylene- diamine phosphate in the eluent at pH 6.0. The propitious buffer effect, however, was attributed, at least in part, to masking the silanol groups at the stationary phase surface by the weak amine component of the buffer. The results demonstrate that besides their classical static role to maintain the pH of a solution constant, buffers may play a variety of other roles and affect significantly the properties and efficiency of a chromatography system.
The upsilon steric parameter — definition and determination

The definition of steric parameters initially based on Van der Waals raddi (rv) is described. Tables of various sets of rv are given. These different types of rv are shown to be interrelated. The rv values of Bondi are chosen as the standard set. Substituents are classified according to the degree of conformational dependence of their steric effect. Values of the steric parameters v are obtained directly from rv whenever possible. For symmetric MZn groups they are obtained from calculated rv values. For planar π-bonded groups equations are derived which permit the calculation of both v and the corresponding delocalized electrical effect parameters. Values of v for other grups are based on kinetic data scaled by correlation with groups for which v is known. Over 300 values of v are reported.
Leveraging sex change in parrotfish to manage fished populations

Healthy parrotfish (family Scaridae) communities fulfill the essential ecosystem process of herbivory in coral reefs, but artisanal fisheries that target parrotfish have degraded their populations. Outright bans and gear restrictions that do not allow parrotfish capture can effectively protect and restore parrotfish populations. As these management actions would be unfeasible in many places, options that allow some fishing but still encourage population rebuilding need to be considered. The life history of parrotfish complicates management decisions because they transition from a mostly female “initial phase” to an all-male “terminal phase.” Size-selective fishing on the largest fish can lead to unnaturally low proportions of males in a population, potentially leading to losses in reproduction. At the same time, these visually distinct life phases could present an opportunity to employ a type of catch restriction that would be easy to understand and monitor. We built an agent-based model of the stoplight parrotfish, Sparisoma viride, which included three possible mechanisms of life-phase transitioning, to predict how this species and others like it might react to catch restrictions based on life phase. We found that restricting catch to only terminal-phase (male) fish typically led to populations of greater abundance and biomass and less-disturbed life-phase ratio, compared to a similar fishing mortality applied to the whole population. This model result highlights a potentially important lesson for all exploited protogynous hermaphrodites: a robust population of initial-phase fish may be key to maximizing reproductive potential when the size at life-phase transition compensates for changes in population structure.
Good Talk and an Aesthetics of Good Sounding in Madagascar

Over the past decades it has become less acceptable simply to acquire new musical knowledge and to present it judiciously, wisely, and authoritatively. The presentation, usually in the form of acad...
The Role of High Molecular Weight Kininogen in Lymphoma Microvascular Density and Growth

Abstract Background: Non-Hodgkin lymphoma (NHL) is a common malignancy in childhood and adolescence. The prognosis of relapsed and refractory NHL remains poor, and new approaches to therapy are needed. High molecular weight kininogen (HK) is a central component of the kallikrein-kinin system. Previous work has demonstrated that in vitro, the kallikrein-cleaved form of HK induces apoptosis of proliferating endothelial cells. Prior studies performed in our laboratory have demonstrated the increased angiogenesis and tumor growth in the absence of HK in B16F10 melanoma and Lewis lung carcinoma models. However, the role of endogenous kininogen in modulating the growth and of hematologic malignancy is unknown. To elaborate the role of HK in in the development and progression of a murine lymphomas, we assessed growth and vascularization of T-cell lymphoma xenografts in wild type (WT) and kininogen deficient (mKNG1-/-) mice. Methods: Murine T-cell lymphoma (EL-4) cells (1 x 10^6) were implanted into wild-type and mKNG1-/- mice. Tumor size was measured using calipers and tumor volume was calculated using the formula V = length x width^2 x 0.52. Fifteen days after cell implantation, tumors were harvested, processed and analyzed by immunofluorescent staining with anti-CD31 antibodies to determine microvascular density (MVD). Results: EL-4 lymphomas grew more rapidly and to larger sizes in mKNG1-/- mice compared to wild-type mice, with significant differences apparent by day 11 after tumor implantation (p Conclusion: These findings suggest that HK is an important endogenous regulator of angiogenesis and tumor growth in this T- cell Lymphoma model. Although the role of kininogen has been described in solid tumor models, this study is the first to demonstrate that kininogen specifically angiogenesis in a hematopoietic tumor. Further work is needed to understand the mechanisms underlying these findings and inform anti-angiogenic therapies to increase the options for patients with hematopoietic malignancies such as NHL. Download : Download high-res image (331KB) Download : Download full-size image Disclosures No relevant conflicts of interest to declare.
125 GeV Higgs boson mass from 5D gauge-Higgs unification

In the context of a simple gauge-Higgs unification (GHU) scenario based on the gauge group $SU(3)×U(1)'$ in a 5-dimensional flat space-time, we investigate a possibility to reproduce the observed Higgs boson mass of around 125 GeV. We introduce bulk fermion multiplets with a bulk mass and a (half) periodic boundary condition. In our analysis, we adopt a low energy effective theoretical approach of the GHU scenario, where the running Higgs quartic coupling is required to vanish at the compactification scale. Under this “gauge Higgs condition,” we investigate the renormalization group evolution of the Higgs quartic coupling and find a relation between the bulk mass and the compactification scale so as to reproduce the 125 GeV Higgs boson mass. Through quantum corrections at the one-loop level, the bulk fermions contribute to the Higgs boson production and decay processes and deviate the Higgs boson signal strengths at the Large Hadron Collider (LHC) experiments from the Standard Model (SM) predictions. Employing the current experimental data which show the the Higgs boson signal strengths for a variety of Higgs decay modes are consistent with the SM predictions, we obtain lower mass bounds on the lightest mode of the bulk fermions.
Delirium and Developmental Disability: Improving Specificity of a Pediatric Delirium Screen.

OBJECTIVES Children with developmental disabilities are at high risk for developing delirium when critically ill. However, existing pediatric delirium screening tools were designed for children with typical development. The objective of this study was to improve the specificity of the Cornell Assessment for Pediatric Delirium, to allow for accurate detection of delirium in developmentally delayed children admitted to the PICU. We hypothesized that the Cornell Assessment for Pediatric Delirium, when combined with fluctuation in level of awareness as measured by the Richmond Agitation-Sedation Scale, would be valid and reliable for the diagnosis of delirium in developmentally delayed children. DESIGN Prospective observational double-blind cohort study. SETTING Tertiary care academic PICU. PATIENTS Children with moderate to severe developmental delay. INTERVENTIONS Each child was evaluated by the bedside nurse with the Cornell Assessment for Pediatric Delirium once every 12 hours and the Richmond Agitation-Sedation Scale every 4 hours. Cornell Assessment for Pediatric Delirium (score ≥ 9) + Richmond Agitation-Sedation Scale fluctuation (change in Richmond Agitation-Sedation Scale score of at least 2 points during a 24-hr period) was compared with the criterion standard psychiatric evaluation for diagnosis of delirium. MEASUREMENTS AND MAIN RESULTS Forty children participated; 94 independent paired assessments were completed. The psychiatrists' diagnostic evaluations were compared with the detection of delirium by the Cornell Assessment for Pediatric Delirium and Richmond Agitation-Sedation Scale. Specificity of the Cornell Assessment for Pediatric Delirium + Richmond Agitation-Sedation Scale fluctuation was 97% (CI, 90-100%), positive predictive value of Cornell Assessment for Pediatric Delirium + Richmond Agitation-Sedation Scale fluctuation was 89% (CI, 65-99%); and negative predictive value remained acceptable at 87% (95% CI, 77-94%). In addition, to confirm interrater reliability of the criterion standard, 11 assessments were performed by two or more psychiatrists in a blinded fashion. There was perfect agreement (κ = 1), indicating reliability in psychiatric diagnosis of delirium in developmentally delayed children. CONCLUSION When used in conjunction with Richmond Agitation-Sedation Scale score fluctuation, the Cornell Assessment for Pediatric Delirium is a sensitive and specific tool for the detection of delirium in children with developmental delay. This allows for reliable delirium screening in this hard-to-assess population.
HPC4Mobilty w/ UCB

Author(s): Nugent, P; MACFARLANE, J | Abstract: The purpose of this project is to examine the energy impact of urban-scale traffic for the Los Angeles Basin by developing and implementing a scalable traffic assignment model. An energy optimization function will be posed and when integrated into the optimization code for travel assignment it can be mathematically proven to converge. The energy optimization function can then be compared to the typical travel time optimization that is traditionally used in traffic assignment models. The analysis will begin with static traffic assignment models with the routing for all origin and destinations computed in parallel on high performance computing facilities. Convergence of the numerical methods rely on the solution of convex programs (or extensions of these). This step will mostly consist of demonstrating the ability to parallelize the Frank Wolfe algorithm on various platforms. This work will contribute to LBNL’s efforts to develop new processes, analytical tools, program designs, and business models to advance the state of the art in next-generation sustainable transportation solutions.
Center for Progressive Reform Report: Protecting Workers In A Pandemic--What The Federal Government Should Be Doing

The "re-opening" of the American economy while the coronavirus that causes COVID-19 is still circulating puts workers at heightened risk of contracting the deadly virus. In some blue-collar industries, the risk is particularly acute because of the inherent nature of the work itself and of the workplaces in which it is conducted. And the risk, for a variety of reasons, falls disproportionately on people of color and low-income workers. With governors stay-at-home orders and other pandemic safety restrictions, Center for Progressive Reform Member Scholars Thomas McGarity, Michael Duff, and Sidney Shapiro examine the federal government's many missed opportunities to stem the spread of the virus in the nation's workplaces, and make recommendations for what needs to happen next to protect employees on the job.
An On-Demand Weather Avoidance System for Small Aircraft Flight Path Routing

Convective weather events pose a challenge to the burgeoning low altitude aviation industry. Small aircraft are sensitive to winds and precipitation, but the uncertainty associated with forecasting and the frequency with which impactful weather occurs require an active detect and response system. In this paper, we propose a dynamic, data-driven decision support system, with components of forecasting, realtime sensor observations, and route planning. We demonstrate our technology in the Dallas/Fort Worth metroplex, a large urban area with frequent thunderstorms which hosts the CASA Doppler radar network.
Unraveling high-energy hadron structures with lattice QCD

Parton distribution functions are key quantities for us to understand the hadronic structures in high-energy scattering, but they are difficult to calculate from lattice QCD. Recent years have seen...
Magnetic and Fluorescent Nanogels for Nanomedicine

The field of nanomedicine has been expanding rapidly in the recent decades that opened the current century. Specifically, nanogels comprise an interesting subset of the nanomedicine design space. A brief overview of the general field of nanotechnology will be introduced and discussion on the role of nanogels. A brief state of the start for applications of magnetic and fluorescent properties and the combination of both are discussed specifically as applied to nanogels. Finally, opinions on the current challenges and future opportunities are discussed with regard to nanogel applications in nanomedicine. Herein, this chapter summarizes some of the important fundamental fields related to this topic and how nanogels intersect other important areas specifically targeting healthcare applications.
Juvenile Retention Polyp in a Teenager

The proper management of a prolapsed rectal mass in a child or teenager is challenging. Given that the underlying etiology of a prolapsed rectal mass in this population is not always immediately clear, interdisciplinary assessment is often required. Juvenile polyps, more commonly presenting with bleeding than a prolapsed mass, can mimic the appearance of both hemorrhoids and the rectum itself - making a purely clinical diagnosis difficult. Presented here is a case of a prolapsed colorectal polyp in a teenage boy, who underwent manual reduction of the mass, followed by colonoscopy and endoscopic ligation. Further histological evaluation revealed it to be a juvenile retention polyp. Despite the rarity of polyp prolapse as a presenting symptom, this case underscores the importance of considering colonic polyps as the etiology of a prolapsed anorectal mass in a teenager.
What caused the tech bubble

According to the efficient market hypothesis, current stock prices precisely reflect all relevant risk and return information. This implies that near-term stock-price changes are random and independent. In a rational pricing environment, investing in the stock market is a “fair game” in which the expected excess return for each security is zero. This means that every stock at every point in time is an equally good buy or sell. In the present stock market environment, accounting misrepresentation and outright fraud at major corporations, the difficulty of assessing future growth prospects for emerging high-tech companies with scant historical experience, and stock market manipulation have all helped undermine the idea of perfect and free information in the stock market. As such, the basis for assuming that the stock market is always perfectly efficient has also been undermined. In such an imperfect environment, bubbles in the stock market can and do occur.
Modeling and Reasoning with Bayesian Networks

This book provides a thorough introduction to the formal foundations and practical applications of Bayesian networks. It provides an extensive discussion of techniques for building Bayesian networks that model real-world situations, including techniques for synthesizing models from design, learning models from data, and debugging models using sensitivity analysis. It also treats exact and approximate inference algorithms at both theoretical and practical levels. The author assumes very little background on the covered subjects, supplying in-depth discussions for theoretically inclined readers and enough practical details to provide an algorithmic cookbook for the system developer.
Aspirin and multiple sclerosis

Aspirin is widely used to lessen the risks of cardiovascular events. Some studies suggest that patients with multiple sclerosis have an increased risk for some cardiovascular events, for example, venous thromboembolism and perhaps ischemic strokes, raising the possibility that aspirin could lessen these increased risks in this population or subgroups (patients with limited mobility and/or antiphospholipid antibodies). However, aspirin causes a small increased risk of hemorrhagic stroke, which is a concern as it could potentially worsen a compromised blood-brain barrier. Aspirin has the potential to ameliorate the disease process in multiple sclerosis (for example, by limiting some components of inflammation), but aspirin also has the potential to inhibit mitochondrial complex I activity, which is already reduced in multiple sclerosis. In an experimental setting of a cerebral ischemic lesion, aspirin promoted the proliferation and/or differentiation of oligodendrocyte precursors, raising the possibility that aspirin could facilitate remyelination efforts in multiple sclerosis. Other actions by aspirin may lead to small improvements of some symptoms (for example, lessening fatigue). Here we consider potential benefits and risks of aspirin usage by patients with multiple sclerosis.
Exploitable molecular mechanisms in hibernation—III: Effects of ligand binding on aromatic circular dichroism of hamster and rat liver diphosphofructose phosphatase

Abstract 1. 1. Significant and specific changes in the aromatic circular dichroic spectrum of liver diphosphofructose phosphatase result upon binding of the substrate, fructose 1,6 diphosphate, of the inhibitor, 5'AMP, and of an activator, (ethylenedinitrilo)tetraacetate (EDTA). Such conformational transitions are of identical nature in the rat and hamster enzyme. However, the phosphatase derived from the rat exhibits a greater susceptibility to conformational transitions. 2. 2. The conformational transitions incited upon binding of 5'AMP are revealed primarily by a large increase in the rigidity of certain phenylalanyl residues. 3. 3. Substrate binding incites an alteration of the assymetric environment of certain tyrosyl residues. 4. 4. The activation of the enzyme by EDTA appears to be associated with an overall decrease in the rigidity of the protein molecule, an effect similar to that induced at alkali solution.
Chemistry and origin of zoned haüyne in tahitian phonolite, with implications for magmatic fractionation

Abstract Unusually fresh, unaltered, chemically zoned nosean and hauyne pheno-crysts found in eight samples of phonolite, nepehelinite and trachyte from Tahiti have been studied in detail. All samples have abundant normative nepheline and modal feldspathoid, both as groundmass phases and as euhedral phenocrysts, commonly quite large. All contain microphenocrysts of titanian clinopyroxene, titanite, apatite and variably titanian magnetite. Some contain small laths of sodic plagioclase or potassic feldspar and most have abundant interstitial groundmass glass. Feldspathoids may be either nosean or hauyne, based on proportions of Ca and Na, but all are rich in SO 4 relative to Cl. Ca and Na variations are sympathetic with variations in bulk rock chemistry. Phenocrysts in all samples show consistent core-to-rim decreases in Ca and K that record shifts in the composition of the melt, indicating crystal fractionation processes in the pre-eruptive magma. Slight Cl enrichment at nosean or hauyne rims and ubiquitous discontinuous, apparently epitaxial, annular rims of end-member sodalite surrounding these crystals indicate exhaustion of magmatic sulfate during feldspathoid phenocryst crystallization and a cessation of hauyne or nosean crystalliza-tion. Sufficient Cl was present in the remaining strongly ne-normative melt to allow the abrupt shift from hauyne to sodalite crystallization. Abundance of sulfate in these rocks (in nosean and hauyne crystals), coupled with absence of any trace of sulfide minerals or any S in ground-mass glass, indicates strong oxidation of magmatic sulfur and total deple-tion of sulfate in the melt during formation of feldspathoid phenocrysts. Cl enrichment in nosean and hauyne rims and the late shift from crystallization of nosean or hauyne to sodalite indicates a significant, probably syn-eruption increase in Cl/S ratio in the magma, possibly contamination by seawater but more likely related to sulfate depletion through feldspathoid crystallization. The bulk sulfur content of these rocks is high (1.5 to as much as 2 wt% SO 2 ), due to abundant sulfate feldspathoid phenocrysts, and probably is close to reasonable sulfur solubilities of such magmas, although data is sparse on S solubilities in phonolitic liquids. Model calculations of the potential effects of hauyne crystallization on residual melt compositions suggest that removal of 10 or 15 modal percent hauyne may significantly decrease magmatic Ca/Na ratio while dramatically increasing silica content, and may help to explain the unusual phonolite-trachyte trend observed in the Tahitian volcanic suite.
Photosynthetic Water‐Splitting for Hydrogen Production

This chapter emphasizes photobiological, H2 producing organisms and processes that are able to link photosynthetic water oxidation (reductant-generation) directly to [FeFe]-hydrogenase-catalyzed H2 production function. The biological catalysts involved in H2 metabolism are either nitrogenases or hydrogenases. Interestingly, the [NiFe], [FeFe], and FeS-cluster free types of hydrogenases are almost completely segregated within specific groups of organisms, suggesting convergent evolution. Two distinct H2 photoproduction pathways have been described in green algae, and there is evidence for a third, light-independent, fermentative H2 pathway coupled to starch degradation. A section summarizes the genetics, expression, maturation, structure, and modeling aspects of [FeFe]-hydrogenases, which catalyze H2 production in green algae. The hydrogenase structural genes that have been cloned and sequenced from species of Chlamydomonas, Chlorella, and Scenedesmus are homologues of the [FeFe]-hydrogenases from bacterial organisms. A majority of the [FeFe]-hydrogenase genes and proteins so far isolated exhibit complex structures that are organized into modular domains. Experimental investigations on the molecular engineering of O2 accessibility in [FeFe]-hydrogenase are currently under way. A better understanding of anaerobic metabolism in Chlamydomonas and metabolic fluxes associated with diurnal periods of light and dark will facilitate the development of physiological models able to predict metabolic fluxes under various environmental conditions. Photosynthesis and H2 production in unicellular green algae can in principle operate with a nearly 100% absorbed photon utilization efficiency. The rate of electron transport in the thylakoid membrane of photosynthesis is of importance for defining yield and efficiency of the overall process.
Design of distance learning presentations

That interactive distance learning (IDL) is becoming more and more popular is a fact; but the effort required to design and present an effective IDL course is almost a "trade secret". Like most tasks, the time and energy that one spends can vary from little to tremendous; so the aim of this paper is to outline the middle ground, and discuss the differences between traditional course and IDL preparations. For purposes of this paper, IDL is based on a system that allows students who are physically separated from the teacher, to interact in real time through both video and audio. This is a high-end system that requires a lot of design time.
Combining metformin therapy with caloric restriction for the management of type 2 diabetes and nonalcoholic fatty liver disease in obese rats

Weight loss is recommended for patients with nonalcoholic fatty liver disease (NAFLD), while metformin may lower liver enzymes in type 2 diabetics. Yet, the efficacy of the combination of weight loss and metformin in the treatment of NAFLD is unclear. We assessed the effects of metformin, caloric restriction, and their combination on NAFLD in diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Male OLETF rats (age 20 weeks; n = 6-8 per group) were fed ad libitum (AL), given metformin (300 mg·kg(-1)·day(-1); Met), calorically restricted (70% of AL; CR), or calorically restricted and given metformin (CR+Met) for 12 weeks. Met lowered adiposity compared with AL but not to the same magnitude as CR or CR+Met (p < 0.05). Although only CR improved fasting insulin and glucose, the combination of CR+Met was needed to improve post-challenge glucose tolerance. All treatments lowered hepatic triglycerides, but further improvements were observed in the CR groups (p < 0.05, Met vs. CR or CR+Met) and a further reduction in serum alanine aminotransferases was observed in CR+Met rats. CR lowered markers of hepatic de novo lipogenesis (fatty acid synthase, acetyl-CoA carboxylase (ACC), and stearoyl-CoA desaturase-1 (SCD-1)) and increased hepatic mitochondrial activity (palmitate oxidation and β-hydroxyacyl CoA dehydrogenase (β-HAD) activity). Changes were enhanced in the CR+Met group for ACC, SCD-1, β-HAD, and the mitophagy marker BNIP3. Met decreased total hepatic mTOR content and inhibited mTOR complex 1, which may have contributed to Met-induced reductions in de novo lipogenesis. These findings in the OLETF rat suggest that the combination of caloric restriction and metformin may provide a more optimal approach than either treatment alone in the management of type 2 diabetes and NAFLD.
Metformin reduces weight, centripetal obesity, insulin, leptin, and low-density lipoprotein cholesterol in nondiabetic, morbidly obese subjects with body mass index greater than 30.

We studied 31 nondiabetic, habitually (> or =5 years) morbidly obese subjects (mean +/- SD body mass index [BMI] 43 +/- 8.7, median 43). Our specific aim was to determine whether metformin (2.55 g/d for 28 weeks) would ameliorate morbid obesity and reduce centripetal obesity; lipid and lipoprotein cholesterol, insulin, and leptin levels; and plasminogen activator inhibitor activity (PAI-Fx), risk factors for coronary heart disease (CHD). The patients were instructed to continue their prestudy dietary and exercise regimens without change. After 2 baseline visits 1 week apart, the 27 women and 4 men began receiving metformin, 2.55 g/d, which was continued for 28 weeks with follow-up visits at study weeks 5, 13, 21, and 29. Daily food intake was recorded by patients for 7 days before visits then reviewed with a dietitian. Kilocalories per day and per week were calculated. At each visit, fasting blood was obtained for measurement of lipid profile, insulin, leptin, and PAI-Fx. The mean +/- SD kilocalories consumed per day, 1,951 +/- 661 at entry, fell by week 29 to 1,719 +/- 493 (P =.014) but did not differ at weeks 5, 13, and 21 from that at week 29 (P >.2). Weight fell from 258 +/- 62 pounds at entry to 245 +/- 54 pounds at week 29 (P =.0001). Girth was reduced from 51.8 +/- 6.2 to 49.2 +/- 4.5 inches (P =.0001). Waist circumference fell from 44.0 +/- 6.4 inches to 41.3 +/- 5.9 (P =.0001). The waist/hip ratio fell from 0.85 +/- 0.09 to 0.84 +/- 0.09 (P =.04). Fasting serum insulin, 28 +/- 15 microU/mL at entry, fell to 21 +/- 11 microU/mL at week 29 (P =.0001), and leptin fell from 79 +/- 33 ng/mL to 55 +/- 27 ng/mL (P =.0001). On metformin, there were linear trends in decrements in weight, girth, waist circumference, waist/hip ratio, insulin, and leptin throughout the study period (P 30, probably by virtue of its insulin-sensitizing action.
Sub-band detection of primary user emulation attacks in OFDM-based cognitive radio networks

This paper considers the primary user emulation attack (PUEA) problem in OFDM-based cognitive radio networks, and proposes a robust and efficient AES-based digital TV (DTV) scheme. In the proposed scheme, the existing reference sequence used to generate the pilot subcarriers in the DTV frames is encrypted using the Advanced Encryption Standard (AES) algorithm for accurate sub-band detection of the authorized primary user, as well as malicious user. For primary user detection, we investigate the cross-correlation between the received sequence and the AES-encrypted reference sequence over a specific frequency sub-band. The malicious user detection can be performed by investigating the auto-correlation of the received sequence. We analyze the effectiveness of the proposed approach through both theoretical derivation and simulation examples. It is shown that, with the AES-based DTV scheme, both the primary user and malicious user can be detected accurately under primary user emulation attacks.
Effect of 17β-estradiol, o,p′-DDT, octylphenol and p,p′-DDE on gonadal development and liver and kidney pathology in juvenile male summer flounder (Paralichthys dentatus)

Abstract The intent of this study was to compare histopathologically the effect of 17β-estradiol (E2), o,p′-DDT, octylphenol and p,p′-DDE on gonadal development and liver and kidney condition in sexually immature (juvenile) summer flounder (Paralichthys dentatus). The dorsal sinus of 2-year-old juvenile male summer flounder was injected with the appropriate amount of chemical incorporated in coconut oil. A second identical injection was administered 2 weeks later. Fish were sampled at 4, 6 and 8 weeks after the initial injection and observed histopathologically. In control fish, spermatogenesis was predominantly in mid to late maturation. In fish treated with 1.0 and 10.0 mg/kg E2 spermatogenesis regressed to primary spermatogonia or an immature functional state. Testicular atrophy and spermatogonial proliferation was also observed. An eosin-positive, hyaline material was found in the gonad, liver and kidney. This eosinophilic material also stained positive with Periodic Acid Schiff (PAS) stain. Treatment of 30 or 60 mg/kg o,p′-DDT elicited altered gonadal development similar to that observed with E2 treated fish. Octylphenol treatment of 100 mg/kg resulted in reduced testicular size, ducts full of sperm, numerous spermatogonia and PAS positive material in the testis with no developing sperm cysts. No effect on liver or gonad tissues was observed with p,p′-DDE at the concentrations tested. All chemicals tested, with exception of p,p′-DDE, altered gonadal development, whereas only E2 caused histopathological changes in the liver and kidney. Estrogenic activity induced the liver to produce a vitellogenin (VtG)-like substance and inhibited testicular maturation. As a result, both the lack of target cells for VtG and a continuous supply of VtG from the liver allowed the hyaline material to accumulate in the liver, testis and kidney causing histopathological changes.
A zero-setter and voltage reference unit for EEG amplifier systems.

This article describes a combined zero-setter and voltage reference unit employed by the authors in the measurement of EEG Averaged Evoked Responses. The sequential pulse generator that synchronously programs the required number of these units is outlined. The method could be of general use whenever an arbitarary zero voltage reference point or baseline is required on a signal waveform.
Path integration for velocity-dependent potentials

We extent the prodistribution definition of path integrals to include Lagrangians with velocity-dependent potentials. We use Cameron-Martin transformations to evaluate a large part of a path integral exactly and give techniques for evaluating the remaining terms of the semi-classical expansion of the path integral. The Fredholm determinants, associated with these transformations, are evaluated explicitly in terms of Jacobi matrices defined by the classical system.
Do persons living near a uranium processing site have evidence of increased somatic cell gene mutations? A first study

Abstract The objective of this study was to examine if individuals living near a uranium processing site have greater mutagenic damage, as measured by three mutagenicity assays, compared with subjects unexposed to any nuclear facilities. The design was a cross-sectional exploratory analysis of 112 subjects; 56 volunteer residents were from within a 5-mile radius of the Fernald Uranium Processing site and 56 ‘control’ subjects were from a geographically separate area unexposed to any known uranium emissions. The groups were constrained to be similar in age and sex composition. The main outcome measures were three human somatic gene mutation assays consisting of the HPRT T-lymphocyte cloning assay to measure 6-thioguanine resistant lymphocytes; the glycophorin A assay to detect the loss of expression of the M or N allele; and the micronucleus assay as a marker of chromosomal damage. The results showed no statistically significant or quantitatively important differences between groups for all three mutagenicity assays; only the unselected cloning efficiency was statistically significantly different between groups (0.42±0.16 for the Fernald versus 0.35±0.12 for the comparison groups). In both groups, age was significantly related to HPRT mutant frequency, with a 1.25% rate of increase in mutant frequencies for each 1-year gain of age in the Fernald group and a 1.12% rate of increase in mutant frequencies for each 1-year gain in the comparison group. For the micronucleus data, females had a greater mean micronucleus frequency than males. In addition, smokers had an increased mean ln (natural logarithm) HPRT mutant frequency (3.06±0.14 for current smokers compared with a mean of 2.72±0.05 for non-current (i.e. never plus former)smokers). Our results are consistent with the previously reported association between sex type and micronucleus frequency, the known relationship between age and T-lymphocyte cloning efficiency and age and HPRT mutant frequency, and verify the wide inter-subject variability for the latter. Finally, we conclude that at a population level, the relationhips between current cigarette use and HPRT mutant frequency, and sex type and micronucleus frequency, are stronger than is the association between geographic proximity to a uranium processing site and mutagenic abnormalities.
A Sociocultural Perspective on At-Risk Asian-American Students:

When discussions of at-risk students arise, Asian-American students are rarely mentioned. The stereotype of the model minority hurts at-risk Asian-American students. While their successful counterparts dominate honor rolls, at-risk Asian-American students are often overlooked and underserved. This paper discusses at-risk Asian-American students from a sociocultural perspective, addressing: (a) society's perceptions of Asian-American students, (b) teachers' perceptions of Asian-American students, (c) the Asian-American community's attitudes towards disabilities, and (d) the relationship of Asian-American students to special education. I conclude with suggestions for the field of education in addressing the needs of Asian-American students.
Laser in situ keratomileusis: Literature review of a developing technique

Abstract We reviewed papers published in peer-reviewed journals describing techniques and results of laser in situ keratomileusis (LASIK) and summarized the instruments used, nomograms, preoperative and postoperative refractions, predictability, outcome, safety, and complications. We performed a similar review of abstracts published in the abstract books of the 1996 meeting of the International Society of Refractive Surgery, the 1997 meeting of the Association for Research in Vision and Ophthalmology, and the 1997 meeting of the American Society of Cataract and Refractive Surgery. The number of LASIK and photorefractive keratectomy (PRK) patients described in the abstracts were sorted by city. Mean weighted latitudes were calculated and compared for each procedure. The mean preoperative refraction in the papers was −12.59 diopters (D), which was statistically higher than that in the abstracts, −8.71 D ( P
Counterion Condensation on Flexible Polyelectrolytes: Dependence on Ionic Strength and Chain Concentration

We give a simple scaling picture for dilute and semidilute solutions of flexible polyelectrolytes including counterion condensation. It is shown that below a critical temperature a fraction of the counterions condenses on the chain. This leads to a renormalization of the total charge of the macroions as well as to a condensation-induced intrachain attraction resulting in a shrinkage of the chain. The paper extends the scaling picture of Schiessel and Pincus [Macromolecules 1998, 31, 7953] for dilute solutions without extra salt to higher ionic strengths and higher chain concentrations. The diagram of states for the different cases is presented.
Philosophical aspects of program verification

Not least among the fascinating issues confronted by computer science is the extent to which purely formal methods are sufficient to secure the goals of the discipline. There are those, such as C. A. R. Hoare and Edsgar Dijkstra, who maintain that, in order to attain the standing of a science rather than of a craft, computer science should model itself after mathematics. Others, including Richard DeMillo, Richard Lipton, and Alan Perlis, however, deny that the goals of the discipline can be gained by means of purely formal methods.
The Extratropical Transition and Precipitation Distribution of Hurricane Floyd (1999)

Abstract Several recent landfalling tropical cyclones (e.g., Dennis, Floyd, and Irene 1999) have highlighted a need for a refinement in the forecasting paradigms and techniques in the area of quantitative precipitation forecasting. Floyd proved to be a particularly challenging forecast problem as it was accompanied by catastrophic flooding over large regions of the East Coast, in spite of its relatively quick northward movement. The extent and intensity of the precipitation distribution was strongly modulated by the storm's interaction with a midlatitude trough. In an attempt to better understand and quantify the relevant dynamics during this interaction, potential vorticity (PV) and quasigeostrophic perspectives are utilized. As Floyd approached the East Coast, precipitation shifted to the left of the storm track due to the presence of a deep midlatitude trough in the Ohio valley. The juxtaposition of a cold-core PV anomaly associated with the midlatitude trough and a warm-core PV anomaly associated with...
Neuroendocrine control of photoperiodically induced fat deposition in white-crowned sparrows.

Electrolytic lesions in the ventral hypothalamus of 28 adult male white-crowned sparrows interrupted photoperiodically induced hyperphagia and fat deposition. Lesions in posterior regions of the infundibular nuclear complex or median eminence (22 birds) eliminated both the fattening response and testicular recrudescence. Lesions restricted to the anterior division of the median eminence or the tractus hypophyseus (6 birds) eliminated the fattening response only.
The utilization of sexual fantasies by sexually experienced university students.

Abstract The purpose of this investigation was to determine the nature of and the gender differences in the situational contexts, preferences, and functions of sexual fantasies by sexually experienced, never-married university students. An anonymous questionnaire was administered to 187 never-married male and 235 never-married female undergraduate and graduate student volunteers at a midwestern commuter university. The data analyses for this investigation were limited to those 144 males and 166 females who had experienced sexual intercourse. Statistically significant differences were found with reference to the situational contexts of sexual fantasies by gender. Men were more likely than women to report sexual fantasies during masturbation, foreplay, sexual intercourse, and immediately prior to orgasm. In general, men also were more likely to fantasize about being the recipient of sexual activity whereas women were more likely to fantasize about past sexual experiences and romantic settings for sexual act...
Antigenically Distinct Populations of Neisseria gonorrhoeae: Isolation and Characterization of the Responsible Determinants

Two antigenically distinct populations of Neisseria gonorrhoeae, tentatively designated Gcl and Gc2, have been identified in 10 randomly selected gonococcal strains. The antigenic determinants responsible for this differentiation have been isolated by DEAE-cellulose chromatography from the alkali-digested phenolwater extract of these strains. Immunodiffusion, immunoelectrophoresis, and electrofocusing studies in acrylamide gel indicate that isolated antigen preparations contain essentially one component. Immunological analysis reveals that these antigens share a core determinant in addition to their respective population-specific determinants. Immunochemical and physicochemical studies demonstrate that the Gcl and Gc2 antigens are acidic polysaccharides with very similar charge and size characteristics.
Scheduling and Reliable Lead-Time Quotation for Orders with Availability Intervals and Lead-Time Sensitive Revenues

Motivated by applications in the manufacturing and service industries, we consider two models for coordinating scheduling with lead-time quotation: a basic model with a single customer type, and an enhanced model where an additional second customer type expects immediate service or production. In both models, revenues obtained from the customers are sensitive to the lead time, there is a threshold of lead time above which the customer does not place an order, and the quoted lead times are 100% reliable. These models are related to well-known scheduling problems, which have been studied in both offline and online settings. We introduce the immediate quotation case and study it with the traditional online version. We provide complexity results for the offline case, and perform competitive analysis for the online cases. A natural question of bridging the gap between the online and quotation models leads us to the delayed quotation model, which we study briefly. The analysis of these models provides useful qualitative insights as well.
Design considerations for monolithic beam formers based on electro-optic polymer phase modulators and strain-induced optical waveguides

The fabrication and characterization of a 1×4-element integrated beam former based on electro-optic (EO) polymer phase modulators (PM) is summarized including findings related to waveguide loss, near-, and far-field diffraction patterns. Based on this device, two alternate designs are proposed to improve performance: an unequally spaced 1×4- element and an equally spaced 1×8-element beam former both based on EO polymer PMs. Models of these alternative designs indicate that waveguide propagation loss and strong grating lobes, both of which degraded the performance of the initial device, can be substantially improved. The proposed approach explored by the 8-element beam former introduces novel components including strain-induced optical waveguides, hybrid integration of active and passive polymers, modified waveguide diffraction aperture, and directional coupler thermo-optic (TO) switches.
DETECTION OP ARRHYTHMIAS IN CHILDHOOD: USE OP TREAD-MILL AND DYNAMIC ECG

Graded treadmill exercise testing(GTET)to elicit and manage arrhytlimias in children with structural heart disease (SHD)was evaluated and compared with dynamic ECG recording(24 hour Holter Monitor (HM). Using the Bruce Protocol, 200 children with SIID and 150 without SHD were exercised with leads II, AVP and V6 monitored. Arrhythmias were present in 58 of 200 patients(pts)with SHD studied by GTET: Ventricular ectopy(VE)in 48, atrial ectopy(AE)or sick sinus syndrome(SSS)in 7, and complete heart block(CHB)in 3. Among the 30 pts with VE at rest, GTET suppressed the ectopy in 15, had no effect in 7 and exacerbated the ectopy in 8(episodes of ventricular tachycardia(VT)in 3). Three of 7 pts with AE or SSS developed short runs of atrial tachycardia and 1 pt with CHB developed three seconds of asystole. Ectopy not suspected before GTET was elicited in 10%(20/200) of pts with SHD, but only 2%(3/150)of those without SHD(X2=7.82P<.01). Serial GTET(N=14)performed in 5 pts with life threatening arrhythmias on therapy demonstrated a reduction in ectopy in 3. HM was obtained within 72 hours of GTET in 21 pts with SHD. Significant arrhythmias were identified by GTET in 4/21 pts(short runs of VT in 3 and 3 second asystole in 1)that wore not demonstrated on HM. No significant arrhythmias were found on HM that were missed by GTET. We conclude that GTET is an excellent method for detecting and inducing arrhythymias in children with SHD and may be useful in evaluating the response to antiarrhythmic therapy. GTET may also reveal serious arrhythmias that are not apparent during HM.
Effects of substituents on the photophysical properties of symmetrical porphyrins

Abstract Porphyrin compounds having groups that mimic the phenolic moiety of m- and p-isomers of 5,10,15,20-tetrakis(hydroxyphenyl) porphyrin (THPP) have been synthesized along with 5,10,15,20-tetrakis(heteroaryl) porphyrins bearing 2-thienyl and 5-thiazolyl groups. Absorption and fluorescence spectroscopy, including fluorescence lifetime (τf) and quantum yield (Φf) measurements, were employed to characterize the singlet excited state of all compounds, using 5,10,15,20-tetraphenylporphyrin (H2TPP) as a standard (Φf = 0.12 in DMF). The generation of singlet oxygen by each porphyrin photosensitizer was measured as the singlet oxygen quantum yield (ΦΔ), using H2TPP as a standard (ΦΔ = 0.64 in DMF). Partition coefficients were determined using 2-octanol as the organic phase and PBS solution as the aqueous phase. Fluorescence quantum yields ranged from 0.01 to 0.18 for all compounds, with heteroaryl porphyrins having the lowest values. Singlet oxygen quantum yields ranged from 0.40 to 0.65, with heteroaryl porphyrins having the highest values, showing them to be better sensitizers than m- and p-THPP. Log P values were all >1 showing higher solubility in the 2-octanol layer.
Modelling and simulating non-stationary arrival processes to facilitate analysis

This paper introduces a method to model and simulate non-stationary, non-renewal arrival processes that depends only on the analyst setting intuitive and easily controllable parameters. Thus, it is suitable for assessing the impact of non-stationary, non-exponential, and non-independent arrivals on simulated performance when they are suspected. A specific implementation of the method is also described and provided for download.