cssi/SciSciGPT-SciSciNet huggingface dataset:
Establishing links between single gold nanoparticles buried inside SiO 2 thin film and 351-nm pulsed-laser damage morphology

A model SiO 2 thin film system with nanoscale absorbing defects (gold nanoparticles) is employed with the goal of unraveling the connection between the pulsed-laser-energy absorption process inside a single nanoscale defect and the resulting film damage morphology. For this purpose, gold nanoparticles are lodged at a well-defined depth inside a SiO 2 monolayer film. Particle sites, as well as damage craters generated at these locations after 351-nm pulsed- laser irradiation, are mapped by means of atomic force microscopy. The results of this mapping confirm mechanism of damage that involves initiation in the nanoscale defect followed by absorption spreading out to the surrounding matrix. At low laser fluences (below optically detected damage onset), the probability of damage crater formation and the amount of the material vaporized is, to within +/- 25% of the average value, almost independent of the particle size. Inhomogeneities in the particle environment are held responsible for variances in the laser-energy absorption process and, consequently, for the observed particle/damage crater correlation behavior. The nanoscale damage threshold is introduced as a laser fluence causing localized melting without significant vaporization.
Synthesis of high specific activity tritium labeled (E)‐6‐(bromomethylene)‐tetrahydro‐3‐(1‐naphthalenyl)‐2H‐pyran‐2‐one as a selective probe for calcium‐independent phospholipase a2

The synthesis of (E)-6-(bromomethylene)-tetrahydro-3-([4-3H]-1-naphthalenyl)-2H-pyran-2-one at a specific activity of 24.0 Ci/mmol is described. This probe was synthesized to determine whether (E)-6-(bromomethylene)-tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one inhibits calcium-independent myocardial phospholipase A2 irreversibly via covalent modification. The material was synthesized in four steps from 1-naphthalene acetic acid via [4-3H]-1-naphthaleneacetic acid. The yield from [4-3H]-1-naphthaleneacetic acid was 29.7%. The radiochemical purity of the HPLC-purified final product was 99.5%.
Social disadvantage and adolescent stress

Abstract Purpose Low socioeconomic status (SES) and minority race/ethnicity are both associated with chronic stress and co-vary in American society. As such, these factors are often used synonymously, without clear theoretical conceptualization of their roles in the development of stress-related health disparities. This study theorized that race/ethnicity and SES reflect social disadvantage, which is the underlying factor in the development of stress-related illness, and examined how social disadvantage, defined in terms of both race/ethnicity and SES, influences adolescents' stress. Methods This is a cross-sectional school-based study of 1209 non-Hispanic black and white 7th–12th graders from a single Midwestern metropolitan public school district. Each student completed a questionnaire and a parent provided SES information. Race/ethnicity was obtained from school records. Linear regression analyses determined the influence of race/ethnicity and SES to stress. Race/ethnicity and presence or absence of at least one parent who graduated from college were used to define four subgroups for within-group analyses. Results Stress was higher among black students, those from lower SES families, and those with lower perceived SES. In subgroup analyses, neither race nor SES maintained their independent associations with stress among socially disadvantaged groups. Black race was not associated with stress among those without a college-educated parent, and parent education did not influence stress among black students. In contrast, among more socially advantaged groups, both SES and race explained variation in adolescents' stress. Conclusions Social disadvantage is associated with increased stress, regardless of whether disadvantage is defined in terms of race or SES. This suggests that race and SES measure adversity in the social environment, and therefore, serve as risk markers, rather than risk factors. Future research should focus on the experience of adversity, which is reflected by these social characteristics, and the processes by which it operates.
Atmospheric particulate matter size distribution and concentration in West Virginia coal mining and non-mining areas

People who live in Appalachian areas where coal mining is prominent have increased health problems compared with people in non-mining areas of Appalachia. Coal mines and related mining activities result in the production of atmospheric particulate matter (PM) that is associated with human health effects. There is a gap in research regarding particle size concentration and distribution to determine respiratory dose around coal mining and non-mining areas. Mass- and number-based size distributions were determined with an Aerodynamic Particle Size and Scanning Mobility Particle Sizer to calculate lung deposition around mining and non-mining areas of West Virginia. Particle number concentrations and deposited lung dose were significantly greater around mining areas compared with non-mining areas, demonstrating elevated risks to humans. The greater dose was correlated with elevated disease rates in the West Virginia mining areas. Number concentrations in the mining areas were comparable to a previously documented urban area where number concentration was associated with respiratory and cardiovascular disease.
The Allometry of Cranial Morphology and Gape Size in Red-Bellied Mudsnakes (Farancia abacura)

Abstract: For snakes, maximum gape size can determine the size and shape of consumable prey. Small body size may accentuate the limitations of gape; however, some evidence indicates that juvenile snakes may compensate for small body size by exhibiting negative gape allometry. In this study, we tested the hypothesis that Red-bellied Mudsnakes (Farancia abacura) display negative allometry for relative gape size. We measured five external head dimensions for each of 10 specimens and directly measured maximum gape circumference using either a ring or bracelet mandrel. Soft tissue was removed from each skull, after which we measured nine osteological features of the cranium. Maximum gape circumference exhibited negative allometry with snout–vent length, as did all cranial dimensions except quadrate length, which was isometric. All cranial bones exhibited positive allometry with skull length except for parietal width, which was isometric with skull length. Based upon a model of the external characteristics usi...
Individual and Mixture Effects of Selected Pharmaceuticals and Personal Care Products on the Marine Phytoplankton Species Dunaliella tertiolecta

Pharmaceuticals and personal care products (PPCPs) entering the environment may have detrimental effects on aquatic organisms. Simvastatin, clofibric acid, diclofenac, carbamazepine, fluoxetine, and triclosan represent some of the most commonly used and/or detected PPCPs in aquatic environments. This study analyzed the individual and mixture toxicity of these six PPCPs to the marine phytoplankton species Dunaliella tertiolecta using a standard 96-hour static algal bioassay protocol. All PPCPs tested had a significant effect on D. tertiolecta population cell density. However, of the six PPCPs tested, only triclosan yielded toxicity at typical environmental concentrations. The 96-hour EC50 values for triclosan, fluoxetine, simvastatin, diclofenac, and clofibric acid were 3.55 μg/L, 169.81 μg/L, 22,800 μg/L, 185,690 μg/L, and 224,180 μg/L, respectively. An EC50 value could not be determined for carbamazepine; however, the highest concentration tested (80,000 μg/L) reduced cell density by 42%. Both mixtures tested—simvastatin–clofibric acid and fluoxetine–triclosan—demonstrated additive toxicity. The presence of PPCP mixtures may decrease the toxicity threshold for phytoplankton populations. Detrimental effects on phytoplankton populations could ultimately impact nutrient cycling and food availability to higher trophic levels. The results of this study are a first step toward identifying the risk of PPCPs to estuarine organisms and may benefit environmental resource managers.
All-fiber mode-locking using a two concentric core fiber saturable absorber

An all-fiber mode-locking element which operates based on nonlinear switching in a novel two concentric core fiber structure is designed. This multicore cylindrically symmetric structure can be easily fabricated.
Counterinsurgency in El Salvador: the lessons and limits of the indirect approach

Following two frustrating counterinsurgency campaigns in Iraq and Afghanistan, there is a drive to find new and more viable ways of addressing irregular security challenges. In this effort, the 1980s' campaign in El Salvador has gained prominence, as it resulted in the defeat of the guerrilla adversary yet involved only a modest deployment of US personnel and resources. The use of history to search for models and precedents can be fruitful, but past conflicts must be understood on their own terms and not made to fit the preconceived ideas of the day. A deeper appreciation of what happened in El Salvador reveals not only the unique circumstances that shaped the campaign but also the limited results of the counterinsurgency program to which the war's outcome is now being ascribed. This article adopts a broader lens, focusing on the real yet undervalued factors that produced peace in El Salvador and whether the final outcome was truly quite as successful as is now commonly assumed.
Influence of antifungal polyenes on the adhesion of Candida albicans and Candida glabrata to human epithelial cells in vitro

Abstract Candidal adherence to mucosal surfaces is considered as the first step in the pathogenesis of oral candidiasis. We examined the effect of antifungal polyenes, amphotericin B, nystatin and natamycin, at sublethal and minimum inhibitory concentrations (MICs) on the adherence of Candida albicans and Candida glabrata to HeLa cervical carcinoma and HSC-3 oral squamous cell carcinoma cells. A total of six oral Candida isolates were used throughout the study. Two Candida strains, C. albicans (44990) and C. glabrata (MYA-275) were obtained from ATCC. Four Candida strains, C. albicans 19 and 24 and C. glabrata 15 and 21, were isolated from patients with documented Candida-associated denture stomatitis. Cells were either incubated with Candida in the presence of the drug, or pre-incubated with yeasts and exposed subsequently to the drug. In the drug-free controls, the mean number of C. albicans yeasts associated with HeLa cells obtained from all experiments (130.1±10.1 yeasts/mm2) was significantly greater than that for HSC-3 cells (114.7±10.1 yeasts/mm2; P 0.4). Candidal adherence was significantly reduced when the tested polyenes were present during the “adherence phase”. The obtained values were significantly different from the controls, except for the effect of nystatin at the MIC on the adherence of C. glabrata strain MYA-275 to HeLa cells (P
An Improved Upper Bound for Leo Moser's Worm Problem

Abstract. A wormω is a continuous rectifiable arc of unit length in the Cartesian plane. Let W denote the class of all worms. A planar region C is called a cover for W if it contains a copy of every worm in W . That is, C will cover or contain any member ω of W after an appropriate translation and/ or rotation of ω is completed (no reflections). The open problem of determining a cover C of smallest area is attributed to Leo Moser [7], [8]. This paper reduces the smallest known upper bound for this area from 0.275237 [10] to 0.260437.
Increasing telmisartan vs amlodipine dose in patients with hypertension, type 2 diabetes and microalbuminuria

Increasing telmisartan vs amlodipine dose in patients with hypertension, type 2 diabetes and microalbuminuria
Effects of As(III) Binding on α-Helical Structure

As(III) displays a wide range of effects in cellular chemistry. Surprisingly, the structural consequences of arsenic binding to peptides and proteins are poorly understood. This study utilizes mode...
The Einstein flow, the sigma-constant and the geometrization of 3-manifolds

For the problem of the Hamiltonian reduction of Einstein's equations on a (3 + 1) vacuum spacetime that admits a foliation by constant mean curvature (CMC) compact spacelike hypersurfaces M that satisfy certain topological restrictions, we introduce a dimensionless non-local time-dependent reduced Hamiltonian system where and Preduced is the reduced phase space. For this system, we establish the following properties: (1) Hreduced has a unique critical point at the hyperbolic point which is a strict local minimum; (2) Hreduced is a strictly monotonically decreasing function along the Einstein flow unless , in which case Hreduced is constant in time; and (3) the infimum of Hreduced is related to the -constant of M by Further applications and developments relating the Einstein flow to (M) and to the geometrization conjecture for 3-manifolds are discussed.
Quantum dot structures and devices with sharp adjustable electronic shells

Abstract Quantum-dot (QD) heterostructures with up to five well-defined electronic shells have been fabricated using self-assembled QDs grown by molecular beam epitaxy (MBE). Shape-engineered stacks of self-aligned QDs with improved uniformity have been used to increase the gain in the active region of laser diodes. Lasing is observed in the upper QD shells for small gain media, and progresses towards the QD ground states for longer cavity lengths. At 77 K thresholds of J th =15 A/cm 2 were obtained for a 2 mm cavity lasing in the first excited state (p-shell), and J th =125 A/cm 2 for a 1 mm cavity lasing in n =3 (d-shell). At 300 K for a 1 mm cavity, J th is 490 A/cm 2 with lasing in n =4 (f-shell). For an increased QD density, J th is smaller than 100 A/cm 2 at room temperature. State-filling spectroscopy is also used to study the effects of alloy intermixing in QD ensembles having well-defined electronic shells and with various densities. Rapid thermal annealing (RTA) is performed on QD samples grown with different intersublevel energy spacings. For InAs/GaAs QDs, the intersublevel is tuned between ∼90 and 25 meV. The intense and sharp shell structures observed in photoluminescence (PL) indicate unambiguously that the QDs retained their zero-dimensional (0D) density of states after the diffusion of the potential, which also causes strong blueshifts (over ∼200 meV) and a pronounced narrowing of the inhomogeneously broadened emission (down to ∼12 meV).
The flavor dependence of the QCD finite temperature phase transition

Abstract We present finite temperature full QCD simulations on 163 × Nt obtained with the 256-node Columbia Parallel processor during the last year. We see a first order transition with four flavors at Nt = 4 for mqa = 0.01, 0.025, 0.0375, and 0.05, and at Nt = 6 for mqa = 0.01 but not for mqa = 0.025, suggesting that the transition weakens as we move closer to the continuum limit. With two flavors at Nt = 4 we do not see a transition for mqa = 0.01 and 0.025. With three flavors at Nt = 4 we see a first order transition for mqa = 0.025; fixing mu, da = 0.025 and increasing the strange quark mass to msa = 0.1 we find no evidence of a transition and that mK/mp = 0.46(1), raising the possibility that in nature QCD may not undergo a finite temperature phase transition.
Posttraumatic Stress Disorder in Incarcerated Juvenile Delinquents

ABSTRACT Objective To assess the prevalence of posttraumatic stress disorder (PTSD) in severely delinquent subjects and to measure associated personality characteristics. Method Eighty-five incarcerated boys (mean age 16.6, SD=1.2) with mostly violent offenses were studied. The sample was representative of the California Youth Authority population. They received a standard psychiatric screen, a semistructured interview for PTSD, and self-report questionnaires measuring personality traits and defenses. A nonclinical sex- and age-matched group was used for comparing psychometrics. Results Subjects suffered from PTSD at higher rates than other adolescent community samples and at higher rates than those found in county probation camps. Thirty-two percent fulfilled criteria for PTSD, 20% partial criteria. One half of the subjects described the witnessing of interpersonal violence as the traumatizing event. Psychometric results converged in the predicted way: Subjects with PTSD showed elevated distress, anxiety, depression, and lowered restraint, impulse control, and suppression of aggression; they had high levels of immature defenses such as projection, somatization, conversion, dissociation, and withdrawal. Conclusions PTSD occurs at high rates in delinquents, and this finding has implications for management and treatment. Personality characteristics that might put individuals at risk for the development of PTSD were identified.
Role of Protein Kinase C in Mitochondrial KATP Channel–Mediated Protection Against Ca2+ Overload Injury in Rat Myocardium

Growing evidence exists that ATP-sensitive mitochondrial potassium channels (MitoKATP channel) are a major contributor to the cardiac protection against ischemia. Given the importance of mitochondria in the cardiac cell, we tested whether the potent and specific opener of the MitoKATP channel diazoxide attenuates the lethal injury associated with Ca2+overload. The specific aims of this study were to test whether protection by diazoxide is mediated by MitoKATP channels; whether diazoxide mimics the effects of Ca2+ preconditioning; and whether diazoxide reduces Ca2+ paradox (PD) injury via protein kinase C (PKC) signaling pathways. Langendorff-perfused rat hearts were subjected to the Ca2+ PD (10 minutes of Ca2+ depletion followed by 10 minutes of Ca2+ repletion). The effects of the MitoKATP channel and other interventions on functional, biochemical, and pathological changes in hearts subjected to Ca2+ PD were assessed. In hearts treated with 80 micromol/L diazoxide, left ventricular end-diastolic pressure and coronary flow were significantly preserved after Ca2+ PD; peak lactate dehydrogenase release was also significantly decreased, although ATP content was less depleted. The cellular structures were well preserved, including mitochondria and intercalated disks in diazoxide-treated hearts compared with nontreated Ca2+ PD hearts. The salutary effects of diazoxide on the Ca2+ PD injury were similar to those in hearts that underwent Ca2+ preconditioning or pretreatment with phorbol 12-myristate 13-acetate before Ca2+ PD. The addition of sodium 5-hydroxydecanoate, a specific MitoKATP channel inhibitor, or chelerythrine chloride, a PKC inhibitor, during diazoxide pretreatment completely abolished the beneficial effects of diazoxide on the Ca2+ PD. Blockade of Ca2+ entry during diazoxide treatment by inhibiting L-type Ca2+ channel with verapamil or nifedipine also completely reversed the beneficial effects of diazoxide on the Ca2+ PD. PKC-delta was translocated to the mitochondria, intercalated disks, and nuclei of myocytes in diazoxide-pretreated hearts, and PKC-alpha and PKC-epsilon were translocated to sarcolemma and intercalated disks, respectively. This study suggests that the effect of the MitoKATP channel is mediated by PKC-mediated signaling pathway.
Increased cell-cell contact stimulates the transcription rate of the tyrosine hydroxylase gene in rat pheochromocytoma PC18 cells

Cell aggregation is one of several environmental cues that influence the expression of neurotransmitter phenotype during development. The expression of the catecholaminergic phenotype is increased in rat pheochromocytoma cells cultured at high density. In the present study we have investigated whether this cell density-mediated effect on the catecholaminergic phenotype is due to the stimulation of the tyrosine hydroxylase gene. When rat pheochromocytoma PC18 cells are cultured at high density (2 x 10(5) cells/cm2), tyrosine hydroxylase enzymatic activity and tyrosine hydroxylase protein increase two- to threefold over that observed in cells cultured at low density (1 x 10(4) cells/cm2). This increase in tyrosine hydroxylase protein observed in high-density cultures is fully accounted for by a preceding increase in tyrosine hydroxylase mRNA levels. The relative transcription rate of the tyrosine hydroxylase gene, measured using a nuclear run on assay, is two- to threefold greater in PC18 cells cultured at high density than in cells cultured at low density. Using flow cytometry, we have determined that in high-density cultures, there are approximately twice as many cells in the G0-G1 phases of the cell cycle compared with the number of G0-G1 cells observed in low-density cultures. However, when G0-G1 cells are isolated by cellular elutriation, tyrosine hydroxylase gene transcription rate remains two- to threefold greater in G0-G1 cells from high-density cultures than in G0-G1 cells from low-density cultures. These results indicate that increased cell-cell contact stimulates the transcription rate of the tyrosine hydroxylase gene, resulting in the subsequent increased expression of tyrosine hydroxylase mRNA and protein.
Dynamics and state of lipid bilayer-internal water unraveled with solution state 1H dynamic nuclear polarization

The dynamics and state of lipid bilayer-internal hydration water of unilamellar lipid vesicles dispersed in solutions is characterized. This study was enabled by a recently developed technique based on Overhauser dynamic nuclear polarization (DNP)-driven amplification of 1H nuclear magnetic resonance (NMR) signal of hydration water. This technique can, in the full presence of bulk water, selectively quantify the translational dynamics of hydration water within ∼10 A around spin labels that are specifically introduced to the local volume of interest within the lipid bilayer. With this approach, the local apparent diffusion coefficients of internal water at different depths of the lipid bilayer were determined. The modulation of these values as a response to external stimuli, such as the addition of sodium chloride or ethanol and the lipid phase transitions, that alter the fluctuations of bilayer interfaces together with the activation energy values of water diffusivity shows that water is not individually and homogeneously solvating lipid's hydrocarbon tails in the lipid bilayer. We provide experimental evidence that instead, water and the lipid membrane comprise a heterogeneous system whose constituents include transient hydrophobic water pores or water structures traversing the lipid bilayer. We show how these transient pore structures, as key vehicles for passive water transport can better reconcile our experimental data with existing literature data on lipid bilayer hydration and dynamics.
Deterministic splitting of fluid volumes in electrowetting microfluidics

Conventional droplet generation approaches in digital microfluidics show ~10% variation in droplet volumes and are restricted to creating only small volumes. In this work, we demonstrate a new approach for splitting sample volumes precisely by gradually ramping down voltage, in place of abruptly switching off electrodes. This allows us to eliminate hydrodynamic instabilities responsible for variations in droplet volume. A simple visual method was developed for measuring sample volumes created on-chip. Our results show that generating and measuring arbitrary sample volumes accurately, with < 1% variation, is possible in electrowetting devices. The approach can be easily extended to existing digital microfluidic systems, and can potentially improve performance of applications requiring precise sample metering, such as immunoassays or DNA amplification.
Two sample distribution-free inference based on partially rank-ordered set samples

Abstract This paper develops distribution-free inference for a location shift model based on a partially rank-ordered set (PROS) sample. In a PROS sample, a small set of experimental units is judgment ranked without measurement by allowing ties whenever the units cannot be ranked with high confidence. These tied units are replaced in partially ordered judgment subsets from which a unit is selected at random for a full measurement. Based on this sampling design, we construct an estimator, a test and a confidence interval for the location shift parameter. It is shown that the new sampling design is robust against any possible ranking error and has higher efficiency than competitor designs in the literature.
Patients' attitudes toward the involvement of medical students in their care

Background Research has shown that medical students are generally accepted by patients, but specific details that elucidate patient perceptions of the advantages and disadvantages to student involvement have not been documented. This study was designed to determine variables that influence patient satisfaction with students. Patients and Methods Patients were interviewed by one of two faculty members using a questionnaire-style format that covered 12 variables regarding patient care. Patients were asked to rate the extent to which medical students helped or hindered their hospital stay, with regard to the 12 variables. Results Patients' attitudes were favorable regardless of the students' extent of clinical experience or clinical abilities or the patients' age or length of hospital stay. Patients reported that students spent time with them and answered their questions. Most patients stated that they would allow students to participate in their future hospital care. Conclusion Positive patient-student interactions can have important effects on patients' expectations and their acceptance of future encounters with students. This fact is becoming increasingly important due to the changes in health care and the decreasing incidence of inpatient surgical encounters.
Natural killer cell-dependent immunoglobulin G2a anti-bovine serum albumin (BSA) response elicited by high molecular weight dextran–BSA conjugates associated with dextran-mediated macrophage–natural killer cell interaction

The roles of the interferon-gamma (IFN-gamma) and interleukin-12 (IL-12) produced during natural killer (NK) cell interaction with macrophages (M phi) were investigated as the basis for the induction of immunoglobulin G2a (IgG2a) anti-bovine serum albumin (BSA) responses by high molecular weight dextran conjugated to BSA (HMW-DEX-BSA). BALB/c mice immunized with HMW-DEX-BSA produced significantly higher levels of both IgG1 and IgG2a anti-BSA than did mice immunized with BSA alone. Both IgG1 and IgG2a anti-BSA levels were higher in mice immunized with BSA conjugated to dextran of molecular weight (MW) 5 000 000-40 000 000 compared with dextran of MW 10,000-60,000. The enhancement of anti-BSA IgG2a levels but not of anti-BSA IgG1 levels was inhibited when free BSA was added to the HMW-DEX-BSA conjugate. NK cell depletion during HMW-DEX-BSA immunization of mice resulted in significantly lower anti-BSA IgG2a levels without affecting anti-BSA IgG1 levels. Naive splenocytes or M phi + NK cell co-cultures incubated with HMW-DEX or HMW-DEX-BSA produced higher IFN-gamma levels than splenocytes or co-cultures incubated with BSA alone. HMW-DEX stimulated both IFN-gamma and IL-12 production by M phi + NK cell co-cultures in a dose-dependent manner. DEX-induced IFN-gamma production by NK cells was dependent upon the presence of IL-12, and IL-12 production by M phi was dependent upon the presence of IFN-gamma in these co-cultures. Both M phi and NK cells bound DEX to their surfaces. These data demonstrate that BSA linked to HMW-DEX enhanced both T-helper-1- and T-helper-2-associated antibody responses to BSA. The results also indicate an IL-12-dependent positive feedback interaction between NK cells and M phi that supports a NK cell/IFN-gamma-dependent mechanism for enhancement of anti-BSA IgG2a antibody responses in mice immunized with HMW-DEX-BSA protein conjugates.
Effect of acute acid-base disturbances on ErbB1/2 tyrosine phosphorylation in rabbit renal proximal tubules

The renal proximal tubule (PT) is a major site for maintaining whole body pH homeostasis and is responsible for reabsorbing ∼80% of filtered HCO3−, the major plasma buffer, into the blood. The PT a...
Effect of 6-Mercaptopurine on Carbohydrate Metabolism of Human Cancer Cells

IN an investigation directed toward the evaluation of the relative effects of various chemotherapeutic chemicals or drugs on the carbohydrate metabolism of intact human cancer cells1, an unpredicted and unusual disappearance of glucose was noted when cells were incubated with 6-mercaptopurine. This effect was discernible under a variety of test conditions; incubation time varied from 1 to 3 hr.; cell concentrations varied from 60 × 106 to 230 × 106; chemical concentration varied from 5 to 50 µgm./106 cells. It was also discernible in all human cell types investigated; acute and chronic lymphatic leukaemia, acute and chronic myelogenous leukaemia, and in ascites cells from patients with carcinoma of the ovaries. It is also readily demonstrated with tumour cell suspension obtained from a transplantable (in Sprague–Dawley rats) chloromyeloid leukaemia2. In all, this effect has been found without exception in some 30 separate examinations of human cancer cells.
S14.1 Genital and oral human papillomavirus in adolescent males

Background Human papillomavirus is a common STI which causes genital warts and cancers in males. Studies of HPV in adult males are underway, but the epidemiology and natural history of HPV in adolescent males has not been investigated. The purpose of this study is to describe genital and oral HPV infections in young men. Methods A subset of young men was recruited from an ongoing study of the male adolescent penile and urethral microbiome and sexual behaviours. Participant consent and parental permission were obtained. This study was approved by the Institutional Review Board at Indiana University. Approximately every 3 months, genital swabs and an oral rinse sample were collected from each participant. Genital swabs were collected using saline wetted cotton swabs rubbed over the entire skin surface of the participant9s glans penis, penile shaft, and scrotum. Participants provided oral samples by a swish and spit method using 15 ml of mouthwash. Samples were tested for HPV using the 37 HPV type Linear Array HPV Genotyping Test (Roche). Participants completed daily cell phone diary entries and quarterly surveys about their sexual behaviours. Descriptive statistical analysis was performed using SPSS. Results A total of 34 adolescent males were recruited, ages 14–18 at enrolment (mean 15.8; SD 1.18). The racial/ethnic identity of participants was: 19 (55.9%) black, 12 (35.3%) white, and 3(8.8%) other. At the time of their first HPV sample collection, 19 participants (55.9%) reported ever having vaginal sex, 8 participants (23.5%) reported ever giving oral sex, 16 participants (47.1%) reported ever receiving oral sex, and 5 (14.7%) reported ever having anal sex. In their enrolment genital samples, HPV (high risk (HR) plus low risk (LR)) was detected in 13 of 34 participants (38.2%); HR types were detected in nine participants and LR types were detected in eight participants. Seven participants had >1 HPV type. HPV was detected in both sexually active participants and those denying prior sexual contact. One participant had trichomonas at enrolment; no participants had gonorrhoea or chlamydia. In the enrolment oral samples, HPV was detected in one participant (HPV 6). Conclusions This study provides the first information about HPV genital and oral infections in adolescent males. Genital HPV can be detected in adolescent males, and is not predicted by prior vaginal or oral sex. Oral HPV was infrequently detected in this small sample.
A novel projection approximation algorithm for the fast and accurate computation of molecular collision cross sections (III): Application to supramolecular coordination-driven assemblies with complex shapes

Abstract The temperature dependence of the cross sections of rectangular, cyclobis[(2,9-bis[ trans -Pt(PEt 3 ) 2 (PF 6 )]anthracene)(4,4′-dipyridyl)] and triangular cyclotris[(2,9-bis[ trans -Pt(PEt 3 ) 2 (PF 6 )]phenanthrene)(4,4′-dipyridyl)] supramolecular assemblies has been investigated by ion mobility mass spectrometry. Molecular dynamics simulations starting with published X-ray structures of both the rectangle and triangle are used to generate model structures. These model structures are used to generate cross sections for comparison with experiment using the simple projection approximation, the computer intensive trajectory method and the new projected superposition approximation (PSA). It is shown that the PSA method provides the best comparison with experiment for these molecules with unusual topographies but the shape factor needs to use a finer mesh in its calculation than for molecules with more regular shapes like folded proteins. Even so the PSA is nearly a factor of 10 faster than the trajectory method for a “small” system like the triangle with 410 atoms.
Migration-Directing Liquid Properties of Embryonic Amphibian Tissues

Deep ectoderm, mesoderm and endoderm excised from gastrulating amphibian embryos spontaneously undergo liquid-like movements in organ culture. Cell populations of these tissues on nonadhesive substrata will round up into spheres, spread over one another and segregate (sort out) from one another just as immiscible liquid droplets do. In ordinary liquids, movements like these are controlled by surface tensions; perhaps surface tensions also control the similar movements of liquid-like tissues. One necessary condition for tissue surface tension analysis is that the tissue must be able (just as ordinary liquids are able) to spontaneously relax internal stretching forces (shear stresses). When cellular aggregates of the germ layers were deformed by gentle compression between parallel glass plates, cells within the aggregates were initially stretched. However, the cells soon returned to their original undistorted shapes. Thus, cell stretching forces were gradually relaxed by cell rearrangements. The in vitro spreading movements of the deep germ layers imply that the surface tension of ectoderm should be greater than the surface tension of mesoderm which should be greater than the surface tension of endoderm. Quantitative measurements of tissue surface tensions made by parallel plate compression confirm precisely that relationship. Furthermore, the surface tensions of these tissues remain constant regardless of the amount of aggregate flattening—another necessary condition for valid surface tension measurements. These results demonstrate that amphibian deep germ layers possess fundamental liquid properties which are sufficient to direct their liquid-like rearrangements in organ culture. Furthermore, I also report that one of these properties, surface tension, displays a preliminary correlation with density of cell surface charge (assessed by electrophoretic mobility) and with the onset of in vivo mesodermal involution.
A rotating parallel hole collimator for high resolution imaging of medium energy radionuclides

A rotating parallel hole collimator has been designed and built for high resolution gamma camera imaging of medium energy radionuclides. This cast lead collimator has 2.0 mm thick septa and was designed for imaging 50-100 mCi I-131 radiolabeled monoclonal antibodies being administered intratumorally for brain tumor therapy. Projection data from different collimator rotation positions are summed to create a composite projection dataset with more dense spatial sampling than projection data at a single position. Measured single photon emission computed tomography (SPECT) resolution with I-131 was 5.5-7.5 mm full-width at half-maximum (FWHM) for a 13 cm radius of rotation compared with 9.9-13.9 mm with a conventional medium energy collimator. SPECT resolution for the rotating collimator was only slightly worse with I-131 than with Tc-99m, indicating good attenuation by the septa. Sensitivity was 56 counts/sec/mCi with a tight region of interest (ROI) around the projection of an I-131 line source 12 cm from the collimator surface and 64 counts/sec/mCi with a tight ROI around the projection of an 11 cm diameter I-131 disk source 10 cm from the collimator surface. SPECT studies of 3.7 cm and 6.2 cm diameter shell-core tumor phantoms filled with I-131 were made. The lower activity core and higher activity shell were well resolved in a SPECT study using the rotating hole collimator. SPECT shell to core activity concentration ratios were more accurate with the rotating collimator than with a medium energy collimator. These results show the potential of this rotating collimator for high resolution human tumor studies with I-131 tracers.
A Survey of Current Disability Management Practice: Emerging Trends and Implications for Certification

This article summarizes the results of a recent role and function study completed in 2004 to determine the prevailing domains of disability management practice. The study also sought to establish a...
Active Tobacco Smoking and Distant Metastasis in Patients With Oropharyngeal Cancer

Purpose: Distant metastasis is the site of first relapse in approximately one-third of patients with locally advanced oropharyngeal carcinoma, irrespective of human papillomavirus status. Yet the risk factors associated with distant metastasis are not well characterized. We sought to characterize the relationship between smoking status and distant metastasis. Methods and Materials: We evaluated the association between tobacco smoking status and distant metastasis in a retrospective cohort study of 132 patients who underwent definitive radiation therapy and chemotherapy for Stage III-IVA/B oropharyngeal cancer. Information on tobacco smoking was prospectively collected by patient questionnaires and physician notes at the time of diagnosis. Thirty-three percent of the patients were nonsmokers, 51% were former smokers, 16% were active smokers. The cumulative lifetime tobacco smoking in pack-years was 20 (range, 0-150). Results: With a median follow-up time of 52 months, the overall rate of distant metastasis at 4 years was 8%. Distant metastasis was the most common first site of relapse, occurring in 56% of the patients with recurrences. Active smokers had higher rates of distant metastasis than non-active smokers (including never- and former smokers; 31% vs. 4%, p 20 and {<=}20 (10% vs. 4%, p = 0.19). In univariate analysis, active smoking (p = 0.0004) and N category (p = 0.009) were predictive of increased risk of distant metastasis. In multivariate analysis, active smoking was the most significant predictive factor for increased risk of distant metastasis (hazard ratio, 12.7, p < 0.0001). Conclusions: This study identified a strong association between active smoking and distant metastasis in patients with oropharyngeal cancer.« less
Optimal Rates of Convergence of Parameter Estimators in the Binary Response Model with Weak Distributional Assumptions

The smoothed maximum score estimator of the coefficient vector of a binary response model is consistent and, after centering and suitable normalization, asymptotically normally distributed under weak assumptions [5]. Its rate of convergence in probability is N−h/(2h+1), where h ≥ 2 is an integer whose value depends on the strength of certain smoothness assumptions. This rate of convergence is faster than that of the maximum score estimator of Manski [11,12], which converges at the rate N−1/3 under assumptions that are somewhat weaker than those of the smoothed estimator. In this paper I prove that under the assumptions of smoothed maximum score estimation, N−h/(2h+1) is the fastest achievable rate of convergence of an estimator of the coefficient vector of a binary response model. Thus, the smoothed maximum score estimator has the fastest possible rate of convergence. The rate of convergence is defined in a minimax sense so as to exclude superefficient estimators.
Methodology for a comparative evaluation of two air–quality models

This paper presents a methodology for conducting an objective comparative evaluation of two air–quality models using several datasets. This methodology is designed to be simple to implement and understand, to reliably discern improvement in performance, and to accommodate the use of datasets from a variety of field studies of varying quality. The reliability of the comparison is enhanced by the segregation of the data into stability and distance regimes. The application of the methodology to compare two air–quality models, using four datasets, demonstrates its use as a practical means for comparing model performance.
HyperSource: bridging the gap between source and code-related web sites

Programmers frequently use the Web while writing code: they search for libraries, code examples, tutorials, documentation, and engage in discussions on QA a novel source document format that maps visited pages to individual characters; and a user interface that enables interaction with these histories.
Relations of Friends’ Activities to Friendship Quality

Two studies were conducted to examine age and sex differences in friends’ activities and relations of participation in these activities to perceived friendship quality. In Study 1, 52 fourth and eighth graders were asked open-ended questions about activities they do with their best friends. In Study 2, 105 fourth and eighth graders reported both on perceived friendship quality and frequency of participation in 40 activities mentioned in Study 1. Eighth graders participated in more school, maintenance, media, and socializing activities with friends than fourth graders did. Boys participated in more sports and media activities with friends than girls did. Students who did more socializing, school, and maintenance activities with friends perceived more positive features in their friendships. These results suggest that engaging in some but not all types of activities with friends may enhance the development of high-quality friendships.
Responses of plants and invertebrate assemblages to water-level fluctuation in headwater wetlands

AbstractFlood-pulsing is a key environmental factor that structures biotic communities in large-order river systems, but we focused our study on the effects of flood-pulsing in headwater systems. We used 10 mesocosm wetlands (10 m × 20 m) to test 2 treatments: a flood-pulse regimen in which natural flood events caused water levels to fluctuate and a static regimen in which water levels remained artificially stable. Abiotic characteristics, plants, and aquatic invertebrate communities were monitored from 2002 through 2005 in permanent pools, nonflooded banks in static wetlands, and intermittently flooded banks in flood-pulse wetlands. The flood-pulse treatment had minimal effects on environmental conditions of permanent pools, and submersed plant and aquatic invertebrate communities in permanent pools were similar in both treatments. This result suggested that resource subsidies from the floodplain to the pools were minimal. However, flood-pulsing caused observable changes to plant communities in the inter...
Face-related ERPs are modulated by point of gaze

This study examined the influence of gaze fixation on face-sensitive ERPs. A fixation crosshair presented prior to face onset directed visual attention to upper, central, or lower face regions while ERPs were recorded. This manipulation modulated a face-sensitive component (N170) but not an early sensory component (P1). Upper and lower face fixations elicited enhanced N170 amplitude and longer N170 latency. Results expand upon extant hemodynamic research by demonstrating early effects at basic stages of face processing. These findings distinguish attention to facial features in context from attention to isolated features, and they inform electrophysiological studies of face processing in clinical populations.
Evidence for Reversible Anodic Stripping of Gallium Potentially Useful for the Rapid Assay Of Gallium

Abstract Electrolyte compositions known to promote reversible a.c. polaro-graphic reduction of Ga(III) at the D.M.E. were examined for use in the ohase-selective anodic stripping [PSAS] of trace gallium using the micrometer hanging mercury drop electrode. Rapidly obtained, sharp gaussian peaks were recorded in the range < 1.0 p. p. m. Ga. These peaks which apparently are manifest only at high ionic strengths could serve as a convenient monitor of tissue-sequestered gallium.
Experience This¡ The Experiential Approach to Teaching Environmental Issues

Experiential education has been promoted by John Dewey and Paulo Freire since the first half of the twentieth century. Freire called the type of teaching where students are passive “banking education.” In this first person account I describe my shift from teaching environmental issues in the traditional style to teaching in an experiential style. As a result of this shift, which involves no lecturing or “banking” on my part, students have rated me as a more outstanding instructor.
Rapid Plasma Exchange with the Continuous Flow Centrifuge

Four cases are described in which rapid exchange of large volumes of plasma (3.8–7.1 liters) was performed with the continuous flow centrifuge and unmodified fresh frozen plasma. Emphasis of this report is on the procedures used and the laboratory evaluation of the effects of plasma exchange. The patients received from 1,000 to 4,900 units of heparin and 628 to 1,299 ml of ACD during the procedure but no hemorrhagic complications were encountered. Supplementary calcium was administered to two patients and no clinical complications caused by hypocalcemia were observed. Serum potassium, chloride and bicarbonate were slightly decreased following plasma exchange, and hypernatremia did not occur. With careful evaluation and monitoring of patients, rapid plasma exchange with the continuous flow centrifuge appears to be practical and safe for the patient.
A SAS Based System for Reporting Laboratory Data from Clinical Trials

A SAS-based laboratory data processing system has been developed to provide reports including patient profiles, abnormality incidences and distribution, safety data summaries, and data edits. Patient profiles display lab data across time with relevant dosing, demographic, concomitant disease and therapy information. Incidence and distribution tables summarize the occurrence of lab abnormalities by drug treatment while safety data summaries provide box plots, bar charts and listings by visit for individual parameters. Data edits allow identification of outliers, errors and missing data. Clinical monitors and data management personnel use these reports for review of on going drug trials. The system has well defined input-interfaces, and is used with data from a variety of laboratories and clinical data processing systems.
Novel piezoelectric actuators for tuning an optical fiber Bragg grating

A method of stretching optical fiber holds interest for measur- ing strain in smart structures where the physical displacement may be used to tune optical fiber lasers. A small, lightweight, tunable fiber laser is ideal for demodulating strain in optical fiber Bragg gratings (FBGs) at- tached to smart structures such as the reusable launch vehicle that is being developed by NASA. A method is presented for stretching optical fibers using the thin-layer composite unimorph ferroelectric driver and sensor (THUNDER) piezoelectric actuators invented at NASA Langley Research Center. THUNDER actuators use a piezoelectric layer bonded to a metal backing to enable the actuators to produce displacements larger than the unbonded piezoelectric material. The shift in reflected optical wavelength resulting from stretching the FBG is presented. Means of adapting THUNDER actuators for stretching optical fibers are discussed, including ferrules, ferrule clamp blocks, and plastic hinges made with stereo lithography. © 2002 Society of Photo-Optical Instrumentation En- gineers. (DOI: 10.1117/1.1504723)