cssi/SciSciGPT-SciSciNet huggingface dataset:
25.1 A highly-digital frequency synthesizer using ring-oscillator frequency-to-digital conversion and noise cancellation

Digital fractional-N PLLs are increasingly used in place of analog fractional-N PLLs as frequency synthesizers in wireless applications, because they avoid large analog loop filters and can tolerate device leakage and low supply voltages, which makes them better-suited to highly-scaled CMOS technology [1-6]. However, the phase noise and spurious tone performance of previously published digital PLLs is inferior to that of the best analog PLLs. This is because all fractional-N PLLs introduce quantization noise, and in prior digital PLLs this noise has higher power or spurious tones than in comparable analog PLLs. Digital PLLs based on ΔΣ frequency-to-digital conversion (FDC-PLLs) offer a potential solution to this problem in that their quantization noise ideally is equivalent to that of analog PLLs, but prior FDC-PLLs incorporate charge pumps and ADCs that have so far limited their performance and minimum supply voltages [7,8]. This paper presents an FDC-PLL that avoids these limitations by implementing the functionality of a charge pump and ADC with a simple dual-mode ring oscillator (DMRO) and digital logic. Also demonstrated is a new quantization noise cancellation (QNC) technique that relaxes the fundamental bandwidth versus quantization noise tradeoff inherent to most fractional-TV PLLs. The new techniques enable state-of-the-art spurious tone performance and very low phase noise with a lower power dissipation and supply voltage than previously published state-of-the-art PLLs in the same class shown in Fig. 25.1.6.
Game-based admission control for wireless systems

Much previous work has examined the wireless power control problem using tools from game theory, an economic concept which describes the behavior of interdependent but non-cooperative users. In this paper, we expand these ideas to the antecedent process of deciding which users may participate in the network, i.e. the admission control problem. In particular, we propose three distinct pricing schemes for influencing users as they make their participation decisions. We fully characterize the equilibria induced by each and then test their performance in a simulated, wireless environment. Our preliminary results show that these schemes have the potential to produce high quality outcomes in an incentive-compatible way.
Digital circles with non-lattice point centers

Digitization of a real circle is defined as the set of closest pixels (integer lattice points) to the circle. These pixels form a digital circle. First, this paper defines the term “closest pixels” and provides an algorithm to digitize an arbitrary circle, i.e., one whose radius is not necessarily an integer, and whose center is not necessarily a lattice point. This digitizing algorithm is simplified to the case of integer radius and integer-coordinate center so that it can be compared to two well-known algorithms: the Bresenham algorithm and an algorithm using the Digital Differential Analyzer (DDA) technique. As a result, the new algorithm consumes only 77% and 40% of the time required for Bresenham and DDA algorithms, respectively. Second, we investigate the problem of finding, for a given digital circle and center, the set of possible real radii that generate that digital circle. For some integerr, we look at all digital circles centered at the origin with real radius in the interval [r−0.5,r+0.5) and determine the paritions of this interval into sub-intervals of real radii generating the same digital circles. Third, we study fixing the digital circle and radius, and finding the set of possible centers. For some pixel (x c,y c), we find the partitions of the unit square [x c −0.5,x c +0.5)×[y c −0.5,y c +0.5) such that for each partition each center in that partition generates the same digital circle. The partition boundaries can be constructed by compass and ruler. Finally, the paper uses these results to determine whether or not a given finite set of pixels is a digital circle segment and if so, shows how to construct its region of possible centers by ruler and compass. We also present an algorithm to detect whether a closed digital are is a digital circle.
Modeling, characterizing, and enhancing user experience in Cloud Mobile Rendering

Cloud Mobile Rendering (CMR), where compute intensive rendering is performed on cloud servers instead of on mobile devices, can be a promising approach to enable rich rendering based multimedia applications on battery and CPU constrained mobile devices. However, since the video rendered in the cloud has to be transmitted to the mobile device over a wireless network with fluctuating and constrained bandwidth, the resulting user experience can be impacted. In [9], an adaptive rendering approach was proposed, wherein multiple rendering factors can be adapted such that the bit rate of the encoded rendered video is compatible with the available network bandwidth. However, changing the rendering factors may itself have adverse impact on user experience, which has not been studied earlier. In this paper, we analyze the impairment of rendering factors on the quality of user experience, and combine the rendering impairments with impairments due to video encoding factors (like bit rate and frame rate) and network factors (like bandwidth and delay) to formulate a model to measure the user experience during a Cloud Mobile Rendering session. We term this model CMR-UE in this paper. We describe our method to derive the CMR-UE model, and demonstrate its accuracy through subjective testing using participants at UCSD. We use the CMR-UE model to study the trade-off between the impact of rendering and video encoding factors on user experience, and find the optimal rendering settings that maximize CMR-UE for any given network condition. Next, we use the CMR-UE model to measure user experience during CMR sessions on a live cellular network. We demonstrate how user experience can be significantly enhanced by using appropriate rendering settings under fluctuating network bandwidth conditions.
Memory and Perfection in Ferroelastic Inclusion Compounds

In a series of ferroelastic urea inclusion compounds (UICs), in which domain reorientation occurs upon application of an external anisotropic force, introduction of a relaxive impurity that disrupts a specific hydrogen-bonding network transforms a plastic (irreversible) domain-switching process into one that exhibits a striking memory effect and 'rubber-like behavior', a form of pseudoelasticity. As expected for a highly cooperative process, the ferroelastic response to the impurity concentration exhibits a critical threshold. Through synchrotron white-beam X-ray topography (SWBXT) of crystals under stress, videomicroscopy of spontaneous repair during crystal growth, acoustomechanical relaxation of daughter domains, kinetic measurements of spontaneous domain reversion, and solid-state {sup 2}H NMR of labeled guests, this work shows how relaxive impurities lower the barrier to domain switching and how differences in perfection between mother and daughter domains provide the driving force for the memory effects. Although the interfacial effects implicated here are different from the volume effects that operate in certain shape memory materials, the twinning and defect phenomena responsible for the rubber-like behavior and memory effects should be generally applicable to domain switching in ferroelastic and ferroelectric crystals and to other solid-state processes.
Complex Formation during SID and Its Effect on Proton Mobility

Surface-induced dissociation (SID) of protonated peptides is a vibrant, active field of study. Significant focus has been placed on understanding the mechanism of dissociation, with most approaches using equilibrium thermodynamic arguments. Here, we explore the dynamics of SID using atomistic simulations. We find that it is common for complexes of peptide fragments to form following dissociation. An important consequence of complexation is that excess protons are not isolated following initial fragmentation and can participate in subsequent chemical reactions. Our work reveals an alternate mechanism for proton mobility that, to our knowledge, has not been previously observed in simulations.
Plant biotechnology: Zinc fingers on target

The existing methods of creating genetically modified plants are inefficient and imprecise. Zinc-finger technology offers the prospect of opening up a swifter and more exact route for crop improvement.
Null-hypothesis tests are not completely stupid, but Bayesian statistics are better

Unfortunately, reading Chow's work is likely to leave the reader more confused than enlightened. My preferred solutions to the “controversy” about null- hypothesis testing are: (1) recognize that we really want to test the hypothesis that an effect is “small,” not null, and (2) use Bayesian methods, which are much more in keeping with the way humans naturally think than are classical statistical methods.
Characterization of immune complexes in progressive rubella panencephalitis

In two patients with the slow virus disease progressive rubella panencephalitis, high levels of immune complexes were found in serum and, in one case, spinal fluid. These complexes contained immunoglobulin G. Serum complexes sedimented over a wide density range compared with the more homogeneous spinal fluid complexes. Complexes from both serum and spinal fluid contained antibody directed against rubella virus. Serum complexes were also shown to contain rubella antigen (or antigens) that appeared to differ between the two patients.
Prospective and longitudinal patient self-assessment of health-related quality of life following radical perineal prostatectomy.

ABSTRACT Purpose: We provide a comprehensive, longitudinal assessment of health related quality of life (HRQOL) following radical perineal prostatectomy (RPP). Materials and Methods: We report the results of a prospective cohort study of 109 patients with at least 3 months of followup who underwent RPP between January 2001 and July 2003. A validated patient self-assessment questionnaire, the Expanded Prostate Cancer Index Composite, was administered preoperatively, and 1, 3, 6, 9, 12 and 18 months postoperatively. Mean domain specific HRQOL scores were calculated as well as the proportion of patients achieving an individual baseline by each interval. The Cox proportional hazards model was used to identify predictors of a successful return to baseline of disease specific HRQOL scores. Results: HRQOL scores were lowest 1 month postoperatively and they increased with time. By 6 months a majority of patients had recovered baseline summary scores in urinary (65.1%), bowel (93.6%) and hormonal (91.7%) domains at a median of 5.8 (95% CI 3.6 to 6.2), 1.3 (95% CI 1.1 to 1.5) and 1.3 (95% CI 1.2 to 1.8) months, respectively. One in 4 patients recovered the sexual summary score by 18 months. Significant independent predictors for the recovery of domain summary scores were younger age in urinary (p = 0.001), individual surgeon in bowel (p = 0.022), and older age (p = 0.017) and absent medical comorbidities (p = 0.012) in hormonal domains. Conclusions: A majority of patients undergoing RRP experience an early recovery of individual urinary, bowel and hormonal HRQOL. Future studies should establish the benefit of bilateral nerve sparing RPP on the recovery of sexual domain HRQOL.
Antigen-specific CD4 T-cell help rescues exhausted CD8 T cells during chronic viral infection

CD4 T cells play a critical role in regulating CD8 T-cell responses during chronic viral infection. Several studies in animal models and humans have shown that the absence of CD4 T-cell help results in severe dysfunction of virus-specific CD8 T cells. However, whether function can be restored in already exhausted CD8 T cells by providing CD4 T-cell help at a later time remains unexplored. In this study, we used a mouse model of chronic lymphocytic choriomeningitis virus (LCMV) infection to address this question. Adoptive transfer of LCMV-specific CD4 T cells into chronically infected mice restored proliferation and cytokine production by exhausted virus-specific CD8 T cells and reduced viral burden. Although the transferred CD4 T cells were able to enhance function in exhausted CD8 T cells, these CD4 T cells expressed high levels of the programmed cell death (PD)-1 inhibitory receptor. Blockade of the PD-1 pathway increased the ability of transferred LCMV-specific CD4 T cells to produce effector cytokines, improved rescue of exhausted CD8 T cells, and resulted in a striking reduction in viral load. These results suggest that CD4 T-cell immunotherapy alone or in conjunction with blockade of inhibitory receptors may be a promising approach for treating CD8 T-cell dysfunction in chronic infections and cancer.
PROGINS Alu insertion and human genomic diversity

A polymorphic Alu element belonging to the young Ya5 subfamily of Alu repeats located in the progesterone receptor gene has been characterized. Using a polymerase chain reaction (PCR)-based assay, the genetic diversity associated with the PROGINS Alu repeat was determined in a diverse array of human populations. The level of insertion polymorphism associated with PROGINS suggests that it will be a useful marker for the study of human evolution. In addition, we determined the distribution of the PROGINS Alu insertion in two groups of women from greater New Orleans, LA with breast cancer. The PROGINS Alu insertion was not associated with breast cancer in the populations tested.
Losing the war against cancer: who's to blame and what to do about it.

In 1971, the U.S. Congress launched a War on Cancer. Eighteen years and billions of dollars later, the United States is still in the grips of a cancer epidemic--and the number of victims grows every year. Much of the money has been squandered on a fruitless search for cancer "cures." Little has been done to prevent exposure to carcinogenic chemicals in the environment, despite ample evidence that chemical pollution of our air, water, food, and the workplace is the major cause of cancer. On the contrary, government, industry, and a small coterie of scientists have combined to stymie efforts to introduce preventive measures, such as strict pollution control standards. But cancer remains a preventable disease. It is up to citizens to push for action.
Computer modeling of environmental chamber measurements of maximum incremental reactivities of volatile organic compounds

Abstract A detailed atmospheric photochemical mechanism which had been previously used in model calculations for developing ozone reactivity scales for volatile organic compounds (VOCs) was evaluated by comparing its predictions with measurements of incremental reactivities in an environmental chamber system. An updated version of this mechanism is also described and evaluated. The experiments consisted of determining the effects of adding representative alkanes, alkenes, aromatic hydrocarbons, aldehydes or CO on NO oxidation, ozone formation and radical levels in a simplified model photochemical smog system representing; conditions where ozone formation is most sensitive to VOCs. The published mechanism correctly simulated the observed qualitative reactivity trends, but overpredicted the effect of adding formaldehyde early in the experiments, performed poorly in simulating reactivities of branched alkanes, tended to underpredict the reactivities of alkenes, and did not simulate differences in reactivities of aromatic isomers. The updates to the mechanism improved the simulation results for the branched alkanes and the alkenes, but not for formaldehyde and the aromatics. The implications of these results concerning the development of atmospheric mechanisms for VOCs are discussed.
Jaw-muscle architecture and mandibular morphology influence relative maximum jaw gapes in the sexually dimorphic Macaca fascicularis

Abstract Maximum jaw gape is a performance variable related to feeding and non-feeding oral behaviors, such as canine gape displays, and is influenced by several factors including jaw-muscle fiber architecture, muscle position on the skull, and jaw morphology. Maximum gape, jaw length, and canine height are strongly correlated across catarrhine primates, but relationships between gape and other aspects of masticatory apparatus morphology are less clear. We examine the effects of jaw-adductor fiber architecture, jaw-muscle leverage, and jaw form on gape in an intraspecific sample of sexually dimorphic crab-eating macaques ( Macaca fascicularis ). As M. fascicularis males have relatively larger maximum gapes than females, we predict that males will have muscle and jaw morphologies that facilitate large gape, but these morphologies may come at some expense to bite force. Male crab-eating macaques have relatively longer jaw-muscle fibers, masseters with decreased leverage, and temporomandibular joint morphologies that facilitate the production of wide gapes. Because relative canine height is correlated with maximum gape in catarrhines, and males have relatively longer canines than females, these results support the hypothesis that male M. fascicularis have experienced selection to increase maximum gape. The sexes do not differ in relative masseter physiologic cross-sectional area (PCSA), but males compensate for a potential trade-off between muscle excursion versus muscle force with increased temporalis weight and PCSA. This musculoskeletal configuration is likely functionally significant for behaviors involving aggressive canine biting and displays in male M. fascicularis and provides additional evidence supporting the multifactorial nature of the catarrhine masticatory apparatus. Our results have implications for the evolution of craniofacial morphology in catarrhine primates and reinforce the importance of evaluating additional factors other than feeding behavior and diet in analyses of masticatory apparatus form, function, and evolution.
Association Between Family Composition and the Well-Being of Vulnerable Children in Nairobi, Kenya

The objective of this study is to examine the relationship between a vulnerable child’s family composition (family size and primary caregiver) and three child well-being indicators (immunization status, access to food, educational security). Using 2006–2009 intake data from a Kenyan non-governmental aid agency, this cross-sectional study evaluated a population of 1,424 children in two urban slum settlements in Nairobi. Logistic regression was used to obtain adjusted odds ratios and 95% confidence intervals to examine the relationship between family composition measures and child well-being. Multivariate results were also stratified by orphan status. Vulnerable children who live in household sizes of 4–6 members and vulnerable children who live with non-relatives had greater odds of inadequate immunization (OR = 1.51, 95% CI: 1.13–2.01, OR = 9.02, 95% CI: 4.62–17.62). Paradoxically, vulnerable children living with non-relative caregivers were at lower risk for inadequate food (OR = 0.19, 95% CI 0.07–0.33). Single orphans with an HIV positive parent were less likely to be fully immunized than single orphans with an HIV negative parent. The results provide information on specific groups which could benefit from increased attention related to childhood immunization education and intervention programs. The findings also underscore the need for policies which support families as a means of supporting vulnerable children. Finally, findings reinforce the wisdom of programs which target vulnerable children based on needs, rather than orphan status. These findings can be useful for informing future program and policy development designed to meet needs of vulnerable children.
Use of Tandem Double J Stents in the Management of Recurrent and Recalcitrant Ureteral Stenosis After Kidney Transplantation

Objective To evaluate the use of tandem double J stents in recalcitrant ureteral stenosis after kidney transplant. Methods We reviewed patients who underwent tandem double J stent placement after kidney transplant, assessing demographics (gender, age, cause of renal failure, recipient implantation site, blood pressure, donor status), renal function, biopsy results, site of stenosis, dilations, time with tandem stents, and outcome. Success was defined as ureteral patency without reconstructive surgery. Student t test was used for creatinine levels. Multivariate survival analysis identified risk factors for failure. Results A total of 19 patients (mean age 36.6 years) were included. The most common site of ureteral stenosis was distal (79%). Average number of biopsies before tandem stents was 1.8 (0-5) and, pathology results showed acute rejection in 16%. Percutaneous nephrostomy was performed after 66.8 ± 140.8 weeks from transplantation date. Dilations averaged 2 ± 1.1 (0-4) before tandem placement. Renal function improved after tandem stents ( P P = .147). The patency success rate was 58% with a mean of 48.7 ± 48 weeks with tandem in place. The failure rate was 26%, with a mean of 16 ± 7 weeks for tandem time. No perioperative complications were identified. Number of dilations before tandem was the only factor associated with failure (hazard ratio=2.61; confidence interval=1.150-5.908, P P = .072) and renal function ( P = .067) were associated with a trend for tandem stent failure. Conclusions Tandem stents can treat recurrent and recalcitrant ureteral stenosis after kidney transplantation that failed previous balloon dilation or ureteral reconstruction.
Identification of acquired thermotolerance deficiency within the ditelosomic series of 'Chinese spring' wheat.

Abstract The relative contribution of individual heat shock proteins to acquired thermotolerance was evaluated through analysis of chromosomal deletions in a ditelosomic series of the hexaploid wheat ( Triticum aestivum L.) cultivar `Chinese Spring'. This study describes the identification of a line within this ditelosomic series that exhibited a reduced level of acquired thermotolerance. Changes in the temperature sensitivity of chlorophyll accumulation were used as an indicator of acquired thermotolerance. The temperature providing maximum chlorophyll accumulation was 30 °C in leaves under continuous light. A 30-min challenge temperature of 48 °C prior to the light exposure was shown to inhibit subsequent chlorophyll accumulation. Preincubation at 40 °C for 4 h before the 30-min 48 °C challenge triggered the acquired thermotolerance system of the plant resulting in chlorophyll accumulation upon exposure to light. Evaluation of the ditelosomic series revealed reductions in acquired thermotolerance levels in the DT7DS line relative to controls. Two-dimensional SDS polyacrylamide gel analysis was used to identify reduction in the level of two low molecular mass heat shock proteins in DT7DS.
Classic pyomyositis of the extremities as an unusual manifestation of Blastomyces dermatitidis: a report of two cases.

Summary Pyomyositis is an infection of skeletal muscle that, by definition, arises intramuscularly rather than secondarily from adjacent infection. It is usually associated with bacterial infection, particularly Staphylcococcus aureus. Fungi are rare causes, and Blastomyces dermatitidis has not been reported previously. In this case series, we report two cases of pyomyositis caused by B. dermatitidis. Cases were prospectively identified through routine clinical care at a single academic referral hospital. Two patients with complaints of muscle pain and subacute cough were treated at our hospital in 2007. Both patients were found to have pyomyositis caused by B. dermatitidis– in the quadriceps muscles in one patient, and in the calf muscle in another – by radiological imaging and fungal culture. Both were also diagnosed with pneumonia caused by B. dermatitidis (presumptive in one, confirmed in the other). There was no evidence of infection of adjacent structures, suggesting that the route of infection was likely direct haematogenous seeding of the muscle. A review of the literature confirmed that although B. dermatitidis has been described as causing axial muscle infection secondary to adjacent infection such as vertebral osteomyelitis, our description of isolated muscle involvement (classic pyomyositis) caused by B. dermatitidis, particularly of the extremity muscles, is unique. We conclude that B. dermatitidis is a potential cause of classic pyomyositis.
The pH of body fluids of marine invertebrates

Abstract 1. 1. The pH of anaerobically handled blood and other body fluids from seventeen species of marine invertebrates was measured at temperatures to which the animals were acclimated. 2. 2. At midsummer temperatures the blood pH of the holothurian Thyone briareus is considerably lower than the mammalian value of 7·4, which has been widely assumed to prevail in poikilothermic animals. Values in a number of decapod crustaceans and gastropod molluscs are considerably higher than 7·4. 3. 3. These values would be expected to increase in other seasons.
Reaction-Map of Organic Chemistry

The Reaction-Map of Organic Chemistry has been designed to give organic chemistry students an overview of most of the reactions needed for the organic chemistry course. The chart has been partially organized according to the periodic table on the horizontal axis and according to carbon oxidation level on the vertical axis. In addition the carboxyls are grouped vertically according to decreasing reactivity, and carbon–carbon bond forming reactions are emphasized with bold arrows. The chart provides a study aid for students and should help students develop synthetic routes from one functional group to another. The chart should be especially useful for students studying for the final examination for the two-semester organic chemistry course. In addition to the chart, three keys are available that organize the reactions according to mechanism, functional group preparations, and functional group reactions. Chemistry can be thought of as a search for order in matter and this chart attempts to provide some insig...
TheQuality Evaluator—A computer application for LANs

WHAT is the most effective way to evaluate the work of students in your classes? Traditionally, an instructor, temporarily assuming the role of “supreme arbiter of quality and judgment,” applies the mental image of “excellent” as a touchstone, then assigns to each submission a letter grade that is calibrated from that standard. Students rarely understand the mental image. Nor do they regularly experience the contrasts between their own work, the work of peers, and their teacher's standard of judgment, all of which account for differences in perceived quality. What students can neither see nor understand, they rarely reach for or achieve.
The application of a.c. impedance technique for detecting glycol contamination in engine oil

Abstract A few hundred ppm of ethylene glycol (a major component in antifreeze) can cause detrimental changes m engine oil. In this work, the a.c. impedance technique has been employed to measure the bulk-layer resistance of engine oil containing glycol. It is found that the bulk-layer resistance declines abruptly as the glycol concentration increases from 50 to 150 ppm. In addition, the bulk-layer resistance for glycol-contaminated engine oil remains constant during a 10-day time span, indicating that the measured resistance is not affected by the formation of micelles between glycol and detergents/dispersants. However, commercial engine oils contain different amounts of detergents, and the bulk-layer resistance for fresh oils varies. Therefore, a software program is necessary to compare the bulk-layer resistance measured from fresh and glycol-contaminated engine oil in order to determine precisely the extent of glycol contamination.
Stability properties of the electron return current for intense ion beam propagation through background plasma

When an intense ion beam propagates through a dense background plasma, its current is partially neutralized by the electron plasma return current. Due to the non-uniformity of the background plasma electrons longitudinal velocity profile (r), the flow can be unstable. The instability is similar to the Kelvin-Helmholz instability for the non-uniform flow of an incompressible neutral fluid, with the electrostatic potential playing the role of pressure. For the case of electron return current flow, the significant new feature is the presence of the partially self-neutralized magnetic field of the ion beam, which significantly affects the evolution of small-amplitude excitations. In this paper the stability properties of the flow of electrons making up the plasma return current is investigated using the macroscopic cold-fluid-Maxwell equations. It is shown that this flow may become unstable, but the instability growth rates are exponentially small. This unstable body mode is qualitatively different from previously studied surface-mode excitations of the electron plasma return current for an intense ion beam with a sharp radial boundary, which is found to be stable due to the stabilizing influence of the partially neutralized magnetic field of the ion beam.
Induction of Activated Lymphocyte Killing by Bacteria Associated with Periodontal Disease

Complex interactions occur among host defense cells during bacterial infection. Bacteria and bacterial products may enhance or inhibit the effector and regulatory activity of human lymphocytes. Accordingly, we tested the ability of human periodontal pathogens to activate peripheral blood lymphocytes using standard 51chromium-release assays to measure lymphocyte-mediated cytolysis. Human adherent-cell depleted peripheral blood lymphocytes (PBL) with the addition of glutaraldehyde-fixed bacteria at a 5:1 bacteria:lymphocyte ratio were incubated at 37°C for 24 hr in RPMI 1640 medium. Six of eight bacteria tested significantly augmented lymphocyte killing of the natural killer (NK) cell-sensitive human erythroleukemia cell line K562. E. corrodens, representing activating bacteria, was also able to induce the killing of NK-resistant targets (M14, Raji), comparable with induction by interleukin-2. Lipopolysaccharides extracted from A. actinomycetemcomitans strains, when incubated with PBL, were able to enhance ...
Nondeterministic polynomial time factoring in the tile assembly model

Formalized study of self-assembly has led to the definition of the tile assembly model, Previously I presented ways to compute arithmetic functions, such as addition and multiplication, in the tile assembly model: a highly distributed parallel model of computation that may be implemented using molecules or a large computer network such as the Internet. Here, I present tile assembly model systems that factor numbers nondeterministically using @Q(1) distinct components. The computation takes advantage of nondeterminism, but theoretically, each of the nondeterministic paths is executed in parallel, yielding the solution in time linear in the size of the input, with high probability. I describe mechanisms for finding the successful solutions among the many parallel executions and explore bounds on the probability of such a nondeterministic system succeeding and prove that the probability can be made arbitrarily close to 1.
A fiber probe for CMM measurements of small features

We report on performance of a new form of fiber probe, which can be used in conjunction with a coordinate measuring machine (CMM) for microfeature measurement. The probe stylus is a glass fiber with a small ball (≈75 μm diameter) glued to the end. When the ball is brought into contact with a surface, the fiber bends, and this bending is measured optically. The fiber acts as a cylindrical lens, focusing transmitted light into a narrow stripe that can be magnified by a microscope and detected by a camera, providing position resolution under 10 nm. In addition to the high resolution, the primary advantage of this technique is the large aspect ratio attainable. (Measurements 5 mm deep inside a 100 μm diameter hole are practical.) Another potential advantage of the probe is that it exerts exceptionally low forces, ranging from a few micronewtons down to hundreds of nanonewtons. Furthermore, the probe is relatively robust, capable of surviving more than 1-mm over-travel, and the probe stylus should be inexpensive to replace if it is broken. To demonstrate the utility of the probe, we have used it to measure the internal geometry of a small glass hole and a fiber ferrule. Although the intrinsic resolution of the probe is better than 10 nm, there are many potential sources of error that could cause larger errors, and many of these errors are discussed in this paper. Our practical measurement capabilities for the hole geometry are currently limited to about 70 nm uncertainty. Hole measurements only require a twodimensional probe, but we have now extended the use of the probe from 2-d to 3-d measurements. Measurements of the z-height of a surface can be carried out by detecting buckling of the stylus when it is brought down into a surface.
Orbital-Mediated Tunneling, Inelastic Electron Tunneling, and Electrochemical Potentials for Metal Phthalocyanine Thin Films

Orbital-mediated electron tunneling through both occupied and unoccupied orbitals of metal phthalocyanines imbedded in metal−insulator−metal tunnel junctions is reported and discussed in terms of transient oxidation and reduction of the molecular species. Electrochemical oxidation and reduction potentials for the solution phase molecular systems are compared to the orbital-mediated tunneling spectroscopy (OMTS) data and a strong correlation is observed. These results are consistent with a simple model. It is demonstrated that different redox sites and states within a given molecule within a thin film will shift in unique ways relative to the equivalent processes in solution. Inelastic scattering from phthalocyanine π−π* transitions and metal centered d−d transitions are also observed.
System to maximize the return signal of ground-penetrating radars

ABSTRACT We examine a ground-penetrating radar system that uses two antennas with their boresight direction maintained at or nearthe Brewster angle for the air-soil interface. For signals going to and returning from the buried target, this arrangementminimizes reflections from the air-soil interface for TM waves and can be used for both ground-based and aircraft-mounted systems. A major problem associated with reliable detection of mines is the weak return signal from the target. This system maximizes signal return from the target by minimizing all reflections except the desired signal reflection from thetarget. We analyzed some soil samples to measure their complex permittivity versus frequency. The real part of the complexpermittivity ranged from 3 to 8 times that of free space, thus, the Brewster angle is between 60 and 70.5 degrees. Forrelatively dry soil and for damp soil, we present calculations of transmission loss versus frequency, due to reflection andabsorption, from transmitter to receiver for both TM and TB waves.Keywords: Brewster angle, mine detection, ground penetration, soil permittivity, radar.
Characterization of antioxidant properties of natural killer-enhancing factor-B and induction of its expression by hydrogen peroxide.

Natural killer-enhancing factor B (NKEF-B) belongs to a highly conserved family of recently discovered antioxidants. The role of NKEF-B as an antioxidant was demonstrated by its protection of transfected cells to oxidative damage by hydrogen peroxide. To further characterize the antioxidant properties of NKEF-B, we compared the sensitivity of a human endothelial cell line ECV304 and its transfectant, B/1 that hyperexpresses NKEF-B, to various oxidants. In addition, we investigated the changes in the expression of NKEF-B mRNA upon oxidative stress. We found that B/1 was significantly more resistant than the control cells to the oxidative stresses caused byt-butyl hydroperoxide (t-BHP) and methyl mercury (MeHg). In contrast, there was no difference in the sensitivity of B/1 and the control cells to sulfhydryl reactive agents, diethyl maleate and diamide. B/1 was also as sensitive as the control cells to buthionine sulfoximine. The expression of NKEF-B mRNA was induced when the parental cell line ECV304 was treated with 2 mmHP. The induction reached a maximum level around 2 hr and decreased to the basal level around 4 hr. NKEF-A mRNA was not induced by HP. These results demonstrate antioxidant activities of NKEF-B toward prooxidants such as alkyl hydroperoxide and MeHg. Together with its antioxidant activity, the induction of NKEF-B by HP indicates that NKEF-B is an important oxidative stress protein providing protection against a variety of xenobiotic toxic agents.
EXPERIMENTAL STUDIES OF THE EVOLUTIONARY SIGNIFICANCE OF SEXUAL REPRODUCTION II. A TEST OF THE DENSITY-DEPENDENT SELECTION HYPOTHESIS

This study tests the hypothesis that one evolutionary advantage of sexual reproduction is that it produces genetically variable progeny with a density-dependent advantage mediated by resource partitioning or pest pressure. Our experimental approach involved planting separate plots of sexually-derived and asexually-derived tillers of the grass Anthoxanthum odoratum in density gradients at the two natural sites from which the source material was taken. The sexual progeny displayed a significant fitness advantage compared to the asexual progeny. But, in contrast to the expectations of the density-dependent selection hypothesis, the advantage of the sexually produced progeny is most marked at lower densities. Thus, the results of this experiment and our previous report (Antonovics and Ellstrand, 1984) seem to best support the frequency-dependent selection hypothesis for the advantage of sexual reproduction.
Lithium ion and electronic conductivity in 3-(oligoethylene oxide)thiophene comb-like polymers

Abstract The Li-ion and electronic conductivities of a series of p-doped poly(thiophene)s with oligo-ethylene oxide side chains have been determined at room temperature as functions of side-chain length and concentration of LiOTf dissolved in the polymers in order to assess their utility as binders in Li-ion batteries. The lithium triflate concentration was varied from 0.23 to 2.26 mmol LiOTf/g –C 2 H 4 O– (100 O:Li to 10 O:Li), and the concentration of dissociated Li + was determined from the IR spectra of the polymer solutions. The greatest ionic conductivity, 2 × 10 −4 S cm −1 , was attained with intermediate concentrations of added salt that corresponded with the greatest degree of LiOTf dissociation. Li-ion mobilities of 5 × 10 −7 cm 2 (Vs) −1 were measured for poly(thiophene)s (PT) with short oligo(ethylene oxide) side-chains ( E n ), PE 2 T and PE 3 T, whereas the polymers with longer side chains, PE 7 T and PE 15 T, had Li-ion mobilities about an order of magnitude greater, 5 × 10 −6 cm 2 (Vs) −1 . The electronic conductivity of the polymers heavily doped with NOBF 4 was near 0.1 S cm −1 for PE 2 T and PE 3 T, but was orders of magnitude smaller for the polymers with longer side-chains. Addition of LiOTf caused the electronic conductivity of PE 2 T and PE 3 T to drop to that of the longer chain polymers whose conductivities were insensitive to the LiOTf concentration.
Electrochemical Behavior of Tennantite in Chloride Solutions

Electrochemical oxidation of tennantite was investigated in this study. Cyclic voltammetry, potential sweep, and potential step techniques were employed for the study. Based on the experimental results, a reaction mechanism of internal diffusion of H 2 O through a sulfur film was proposed to describe the effect of H + , Cu 2+ , Cl - , and temperature. The relatively small value of charge-transfer coefficient of the reaction, which was obtained from the Tafel slope, and the irreversibility of the reaction could also be explained by this mechanism. Different sulfur allotropes with various porosities and thicknesses contribute to an unusual temperature effect on tennantite oxidation in conditions of below 60°C and a potential range of 0.8-1.2 V.
Exercise affects both ovarian follicular dynamics and hormone concentrations in mares.

The objectives were to evaluate the effects of exercise on ovarian folliculogenesis and related hormones in mares. Mares (n = 11) were randomly assigned into a control (non-exercised) or treatment (exercised) group. Treatment mares (n = 5) were moderately exercised for 30 min, 6 d/wk. All mares underwent daily transrectal ultrasonographic examinations and ovarian follicles > 6 mm were measured. Blood samples were collected during the first (Cycle 1) and last (Cycle 4) cycle, and serum concentrations of cortisol, LH, and FSH were determined. Mean cortisol concentrations were elevated (P 20 mm following deviation. The dominant and largest subordinate follicle in exercised mares had a greater (P < 0.05) mean diameter on the day of deviation, suggesting delayed deviation. Exercised mares also tended (P = 0.06) to have an increased number of cycles with at least two dominant follicles compared to control (62 vs 36%, respectively), indicating a decreased ability of the largest follicle to assert dominance. Under the conditions of this study, moderately exercising mares induced higher cortisol concentrations, lowered peak LH concentrations, and altered ovarian follicular dynamics.
107 Epidemiologic methods and the tobacco debate

Abstract PURPOSE: Ronald Aylmer Fisher and Joseph Berkson remain infamous today for their stand in the debate over the emerging evidence on the health effects of tobacco during the 1950s and 1960s. However, throughout this period there were a substantial number of senior statisticians and epidemiologists, including Caroll Palmer, Jacob Yerushalmy, Donald Mainland, Herbert Lombard, KA Brownlee, Edwin Wilson, George Saiger, Alexander Gilliam, and others, who were critical of claims that cigarette smoking had been demonstrated to be a cause of lung cancer. We sought to characterize the scientific arguments of these skeptics and to understand the historical context that contributed to their concerns. METHODS: We identified research articles, commentaries, and reviews on the epidemiology of smoking and lung cancer between 1950 and 1968. We also reviewed textbooks from this period on epidemiology, survey design, and experimental statistics. We searched for additional documents, conference transcripts, and unpublished papers by key names in electronic tobacco industry document repositories. RESULTS: Epidemiologists and biostatisticians expressed concerns about widespread abuses of statistical methods in the literature, particularly an excessive emphasis on statistical significance tests to find differences between groups of patients. Epidemiologists and statisticians on both sides of the tobacco debate described themselves as methodological reformers at a time when statistical thinking was still working its way into medicine. CONCLUSION: The methodological arguments expressed by Berkson and Fisher were shared by many of their colleagues, including those who argued that the case against cigarettes was sufficient for taking action. However, the adversarial nature of the public debate and the industry's aggressive public relations campaign exaggerated methodological differences that were often quite subtle. This case provides useful lessons for epidemiologists today involved in methodological debates with implications for policy and financial interests.
Vitalizing the Group—And Me

Abstract Emotional liveliness in a psychotherapy group can take various forms. Maintaining this liveliness can be a challenging task in a group, particularly when both the patients and the therapist face deeply rooted inhibitions, including fears about competition, being judged, and being destructive. The author of this paper, a candidate and group member in a postdoctoral group psychotherapy training program, recounts some of her experiences as the leader of a newly formed and developing group, particularly as they relate to her efforts to become and remain a “libidinal” (i.e., life or vital force) leader, despite the impact of the group members' and her own anxieties. Clinical anecdotes and insights about the author's own growth, both personally and professionally, as they relate to establishing and maintaining vitality are presented.
Parkin: a multifaceted ubiquitin ligase.

Mutations in the parkin gene are a common cause of autosomal recessive early-onset parkinsonism. Parkin functions as an E3 ubiquitin ligase where it can polyubiquitinate a number of its protein substrates, thus targeting them for degradation by the 26 S proteasomal complex. Recent studies have demonstrated that alternative modes of parkin-mediated ubiquitination may serve other non-degradative regulatory roles. In addition, parkin appears to function as a multipurpose neuroprotectant in a number of toxic paradigms. Coupled with these observations, parkin may integrate other gene products associated with parkinsonism, including α-synuclein, LRRK2 (leucine-rich repeat kinase 2), DJ-1 and PINK1 [PTEN (phosphatase and tensin homologue deleted on chromosome 10)-induced putative kinase 1], into a common biochemical pathway of potential relevance to disease pathogenesis. Parkin therefore represents a unique multifaceted ubiquitin ligase consistent with an important housekeeping role in maintaining the integrity or survival of dopaminergic neurons.
Differences in Psychological Need Hierarchy between Program Completers and Dropouts from a Drug Abuse Treatment Program

Psychological need patterns among 116 drug addicts in treatment were measured with the Adjective Checklist. Compared to program completers, program dropouts had higher needs for autonomy and aggression and lower needs for deference, nurturance, and affiliation. This personality style may form the basis of dropping out, among certain types of addicts in certain types of programs, when faced with situational, environmental, or interactional stress. Results also suggest that we may be able to identify a personality pattern at risk for premature termination before the person experiences the impulse to leave.
Agricultural chemical export dynamics in a watershed

[1] Understanding how agricultural chemicals filter through a catchment is important for managing water quality. Using a concept of the catchment as a physicochemical filter, Guan et al. examined nitrate, phosphate, and atrazine loads in the Little Vermillion River watershed, a tile-drained watershed in Illinois. They analyzed a 10-year data set using mathematical signal processing to investigate spatial and temporal patterns in chemical concentrations and discharge rate. They found that export of these chemicals had a linear relationship with streamflow at annual scales—the higher the streamflow, the more these chemicals were exported from the watershed. The researchers' approach helps identify the roles of different hydrological flow paths in controlling chemical export at different spatial and temporal scales and reveals that chemical inputs overwhelm normal biogeochemical processing in these agricultural systems, leading to high long-term average rates of export. (Water Resources Research, doi:10.1029/2010WR009997, 2011)