cssi/SciSciGPT-SciSciNet huggingface dataset:
Incremental mechanism design

Mechanism design has traditionally focused almost exclusively on the design of truthful mechanisms. There are several drawbacks to this: 1. in certain settings (e.g. voting settings), no desirable strategy proof mechanisms exist; 2. truthful mechanisms are unable to take advantage of the fact that computationally bounded agents may not be able to find the best manipulation, and 3. when designing mechanisms automatically, this approach leads to constrained optimization problems for which current techniques do not scale to very large instances. In this paper, we suggest an entirely different approach: we start with a naive (manipulable) mechanism, and incrementally make it more strategy proof over a sequence of iterations. We give examples of mechanisms that (variants of) our approach generate, including the VCG mechanism in general settings with payments, and the plurality-with-runoff voting rule. We also provide several basic algorithms for automatically executing our approach in general settings. Finally, we discuss how computationally hard it is for agents to find any remaining beneficial manipulation.
Hamilton-type principles applied to ice-sheet dynamics: new approximations for large-scale ice-sheet flow

Ice-sheet modelers tend to be more familiar with the Newtonian, vectorial formulation of continuum mechanics, in which the motion of an ice sheet or glacier is determined by the balance of stresses acting on the ice at any instant in time. However, there is also an equivalent and alternative formulation of mechanics where the equations of motion are instead found by invoking a variational principle, often called Hamilton's principle. In this study, we show that a slightly modified version of Hamilton's principle can be used to derive the equations of ice-sheet motion. Moreover, Hamilton's principle provides a pathway in which analytic and numeric approximations can be made directly to the variational principle using the Rayleigh-Ritz method. To this end, we use the Rayleigh-Ritz method to derive a variational principle describing the large-scale flow of ice sheets that stitches the shallow-ice and shallow-shelf approximations together. Numerical examples show that the approximation yields realistic steady-state ice-sheet configurations for a variety of basal tractions and sliding laws. Small parameter expansions show that the approximation reduces to the appropriate asymptotic limits of shallow ice and shallow stream for large and small values of the basal traction number.
Beam path toxicities to non-target structures during intensity-modulated radiation therapy for head and neck cancer.

Background Intensity-modulated radiation therapy (IMRT) beams traverse nontarget normal structures not irradiated during three-dimensional conformal RT (3D-CRT) for head and neck cancer (HNC). This study estimates the doses and toxicities to nontarget structures during IMRT. Materials and Methods Oropharyngeal cancer IMRT and 3D-CRT cases were reviewed. Dose–volume histograms (DVH) were used to evaluate radiation dose to the lip, cochlea, brainstem, occipital scalp, and segments of the mandible. Toxicity rates were compared for 3D-CRT, IMRT alone, or IMRT with concurrent cisplatin. Descriptive statistics and exploratory recursive partitioning analysis were used to estimate dose “breakpoints” associated with observed toxicities. Results A total of 160 patients were evaluated for toxicity; 60 had detailed DVH evaluation and 15 had 3D-CRT plan comparison. Comparing IMRT with 3D-CRT, there was significant (p ≤ 0.002) nonparametric differential dose to all clinically significant structures of interest. Thirty percent of IMRT patients had headaches and 40% had occipital scalp alopecia. A total of 76% and 38% of patients treated with IMRT alone had nausea and vomiting, compared with 99% and 68%, respectively, of those with concurrent cisplatin. IMRT had a markedly distinct toxicity profile than 3D-CRT. In recursive partitioning analysis, National Cancer Institute's Common Toxicity Criteria adverse effects 3.0 nausea and vomiting, scalp alopecia and anterior mucositis were associated with reconstructed mean brainstem dose >36 Gy, occipital scalp dose >30 Gy, and anterior mandible dose >34 Gy, respectively. Conclusions Dose reduction to specified structures during IMRT implies an increased beam path dose to alternate nontarget structures that may result in clinical toxicities that were uncommon with previous, less conformal approaches. These findings have implications for IMRT treatment planning and research, toxicity assessment, and multidisciplinary patient management.
Confirmatory Factor Analysis of Scores on the Clinical Experience Rubric: A Measure of Dispositions for Preservice Teachers

This study examines the underlying structure of the Clinical Experience Rubric (CER), which is designed to assess preservice teachers’ dispositions during the clinical experiences. Dispositions wer...
Two- and three-grating resonators for high-power pulsed CO(2) lasers.

Development of broadly tunable narrow-linewidth CO2 lasers is critical to the continued development of tunable far-infrared Raman lasers and could also improve many other optical pumping experiments. Here we extend the use of multiple intracavity gratings, a widely used dye laser technique, to multiatmosphere continuously tunable CO2 lasers. We analyze the angular dispersion, wavelength tuning performance, and grating size requirements for several different grating configurations. Experimentally, by double passing each of two gratings worked near grazing incidence in a three-mirror 10-atm laser resonator, we have produced ∼200-mJ pulses with < 600-MHz linewidth, and our analysis shows that operation in a single longitudinal mode (SLM) should be possible at somewhat reduced output levels. The simpler experimental task of producing SLM operation in a two-grating CO2 transversely excited atmospheric laser has also been accomplished.
Viability and function of platelets frozen at 2 to 3 C per minute with 4 or 5 per cent DMSO and stored at -80 C for 8 months.

Each of 15 healthy male volunteers was treated with 650 mg of aspirin 24 hours before the autologous transfusion of one unit of freeze-preserved platelets. Freeze-thaw-wash recovery values in vitro, viability and function in vivo, and the bleeding time and platelet aggregation response were measured. The platelets were frozen with 4 or 5 per cent dimethylsulfoxide (DMSO) at an overall rate of 2 to 3 C per minute and were stored at −80 C in a mechanical freezer for up to eight months. They were washed by dilution/centrifugation. The mean recovery in vitro of platelets frozen with 4 per cent DMSO was 76 ± 16 per cent; the value was 64 ± 16 per cent for platelets frozen with 5 per cent DMSO. The mean in vivo 51Cr recovery of autologous platelets frozen with 4 per cent DMSO was 34 ± 6 per cent, and for platelets frozen with S per cent DMSO it was 33 ± 7 per cent. In both groups the platelet lifespan was normal. There was a significant reduction in bleeding time after the transfusion of a single unit of autologous platelets preserved with either 4 or 5 per cent DMSO, but no improvement in the aspirin-induced platelet aggregation pattern.
Asymmetric Information, Managerial Opportunism, Financing, and Payout Policies

We examine corporate issuance and payout policies in the presence of both adverse selection (in capital markets) and managerial opportunism. Our results establish the importance of the locus of decision control in the firm. When shareholders determine policies, debt financing is always optimal in the presence of either adverse selection or managerial opportunism. However, when both of these problems are simultaneously present, equity issuance can become an optimal signaling mechanism. Shareholders' most preferred signaling mechanism is restricting dividends, followed by equity financing, and finally underpricing securities. When managers determine policies, a reversed hierarchy may be obtained.
Interrelationships between asthma and pregnancy: a literature review.

Abstract Pregnancy can affect the course of asthma, and asthma can affect pregnancy outcomes. Asthma course may improve, worsen, or remain unchanged during pregnancy. The mechanisms involved have not been defined, and the course in an individual woman is largely unpredictable. Therefore pregnant women with asthma must be followed up particularly closely so that any change in course can be matched by an appropriate change in therapy. The data also suggest that asthma is associated with increased frequencies of adverse pregnancy outcomes. The mechanisms of this are not totally clear either, but some data support the hypothesis that improved pregnancy outcomes are associated with well-controlled disease. The risk of using medications to control asthma during pregnancy appears to be much less than the risk of adverse outcomes related to severe uncontrolled asthma. (J Allergy Clin Immunol 1999;103:S330-6.)
Measured Diffusion Capacity versus Prediction Equation Estimates in Blacks without Lung Disease

Background: Lung volumes in African-Americans are on average 10–15% less than in Caucasians for the same height and are race corrected accordingly. Despite this fact, prediction equ
Sex Stereotypes in Language Intervention Materials for Children

The two major purposes of the current study were: (1) to develop a procedure for use in analyzing the extent to which sex-stereotyping is present in language intervention materials, and (2) to utilize this analytic procedure to measure the amount of sex-stereotyping in ten sets of materials frequently employed in the management of language disordered children. Twenty judges rated 243 common activities and situations on a seven-point masculinity-femininity scale. The mean ratings of the judges were then utilized in analyzing the language intervention materials. Evidence of sex-stereotyping was found, including underrepresentation of females and depiction of both males and females in roles reflecting traditional sex-stereotyping. Some sets of materials displayed more sex-stereotyping than others. Ways in which speech-language pathologists might reduce the influence of sex-stereotyping in materials are discussed.
Renal autotransplantation: a reappraisal

Renal autotransplantation has become the treatment of choice for selected patients with difficult urological problems such as extensive ureteral loss, complicated renovascular disease, renal malignancy requiring nephron-sparing surgery, the loin pain-hematuria syndrome, and severe renal trauma. This approach offers specific advantages in each of these categories, including the option to carry out extracorporeal repair of the kidney if necessary. This is also often the only available technique for achieving reconstruction and salvage of the involved kidney. The long-term results with renal autotransplantation are excellent and support its continued application in appropriate clinical conditions.
Tree-ring reconstructed megadroughts over North America since a.d. 1300

Tree-ring reconstructed summer Palmer Drought Severity Indices (PDSI) are used to identify decadal droughts more severe and prolonged than any witnessed during the instrumental period. These “megadroughts” are identified at two spatial scales, the North American continental scale (exclusive of Alaska and boreal Canada) and at the sub-continental scale over western North America. Intense decadal droughts have had significant environmental and socioeconomic impacts, as is illustrated with historical information. Only one prolonged continent-wide megadrought during the past 500 years exceeded the decadal droughts witnessed during the instrumental period, but three megadroughts occurred over the western sector of North America from a.d. 1300 to 1900. The early 20th century pluvial appears to have been unmatched at either the continental or sub-continental scale during the past 500 to 700 years. The decadal droughts of the 20th century, and the reconstructed megadroughts during the six previous centuries, all covered large sectors of western North America and in some cases extended into the eastern United States. All of these persistent decadal droughts included shorter duration cells of regional drought (sub-decadal ≈ 6 years), most of which resemble the regional patterns of drought identified with monthly and annual data during the 20th century. These well-known regional drought patterns are also characterized by unique monthly precipitation climatologies. Intense sub-decadal drought shifted among these drought regions during the modern and reconstructed multi-year droughts, which prolonged large-scale drought and resulted in the regimes of megadrought.
A surgical operating apparatus for fish and its use in the pinealectomy of salmonids

A surgical operating apparatus for fish that is effective for cranial surgery is described. The fishes are secured with clamp-arms which extend against the pectoral and pelvic girdles. The head is held by a plexiglass mouthpiece, designed specifically for the fish species under investigation. The mouthpiece is also responsible for gill irrigation. The use of the apparatus for the surgical pinealectomy of salmonids is described.
Singular quasilinear and Hessian equations and inequalities

We solve the existence problem in the renormalized, or viscosity sense, and obtain global pointwise estimates of solutions for quasilinear and Hessian equations with measure coefficients and data, including the following model problems: −Δpu=σuq+μ,Fk[−u]=σuq+μ,u⩾0, on Rn, or on a bounded domain Ω⊂Rn. Here Δp is the p-Laplacian defined by Δpu=div(∇u|∇u|p−2), and Fk[u] is the k-Hessian, i.e., the sum of the k×k principal minors of the Hessian matrix D2u (k=1,2,…,n); σ and μ are general nonnegative measurable functions (or measures) on Ω.
Sizing up portal hypertension: Better noninvasive methods are needed

The “congestion index” is used to mean the ratio between the cross-sectional area (cm2) and the blood flow velocity (cm/sec) of the portal vein, as determined by a duplex Doppler system. The indices as determined in normal subjects and patients with liver disease were as follows: normal subjects (n = 85), 0.070 ± 0.029 cm × sec; acute hepatitis (n = 11), 0.071 ± 0.014 cm × sec; chronic active hepatitis (n = 42), 0.119 ± 0.084 cm × sec; cirrhosis (n = 72), 0.171 ± 0.075 cm × sec; and idiopathic portal hypertension (n = 11), 0.180 ± 0.107 cm × sec. There was a statistically significant difference between the congestion indices from the normal subject group and indices obtained from patients with chronic hepatitis, cirrhosis, and idiopathic portal hypertension. A weak positive correlation was obtained between the congestion index and the portal venous pressure, measured simultaneously through a percutaneously placed catheter (n = 64, r = 0.45, p < 0.01). It is suggested that the congestion index reflects the pathophysiological hemodynamics of the portal venous system in portal hypertension.
Drugs and Diseases Interacting with Cigarette Smoking in US Prescription Drug Labelling.

The US Food and Drug Administration (FDA) draft guidance for industry on drug interaction studies recommends, but does not mandate, that both cigarette smokers and non-smokers can be used to study drug metabolism in clinical trials, and that important results related to smoking should be included in drug labelling to guide medication usage. This study aimed to provide a comprehensive review of drugs or diseases interacting with smoking, as presented in all US drug labelling. The 62,857 drug labels deposited in the FDA Online Label Repository were searched using the keywords ‘smoke’, ‘smoker(s)’, ‘smoking’, ‘tobacco’ and ‘cigarette(s)’ on 19 June 2014. The resultant records were refined to include only human prescription drug labelling, for manual examination. For 188 single-active-ingredient drugs and 36 multiple-active-ingredient drugs, the labelling was found to contain smoking-related information. The pharmacokinetics of 29 and 21 single-active-ingredient drugs were affected and unaffected, respectively, by smoking. For the remaining drugs, the provided information related to smoking affecting efficacy, safety or diseases but not pharmacokinetics. Depending on the nature of specific drugs, the perturbation in pharmacokinetic parameters in smokers ranged from 13 to 500 %, in comparison with non-smokers. Dosage modifications in smokers are necessary for four drugs and may be necessary for six drugs, but are unnecessary for seven drugs although the pharmacokinetic parameters of four of them are affected by smoking. Cigarette smoking is a risk factor for 16 types of diseases or adverse drug reactions. For one single-active-ingredient contraceptive drug and 10 multiple-active-ingredient contraceptive drugs, a black box warning (the FDA’s strongest safety warning) is included in the labelling for increased risks of heart attacks and strokes in female smokers, and “women are strongly advised not to smoke” when using these drugs. This study presents the first comprehensive overview of cigarette smoking interacting with drugs and/or diseases, as presented in US drug labelling.
Radiochemical tests of double beta decay

We discuss the feasibility of radiochemical and geochemical measurements of the rates for two double beta decay reactions, /sup 238/U..-->.. /sup 238/Pu and /sup 232/Th..-->.. /sup 232/U, that produce unstable daughter nuclei.
Bison trails and their geologic significance

Bison trails are conspicuous on aerial photographs of many parts of the mid-continent grasslands. Bison trails have been mistaken for glacial disintegration trenches, joints, and faults. The trails probably had an influence on the present drainage pattern of the Great Plains.
The role of nutrition in Alzheimer's disease: epidemiological evidence.

The prevalence of Alzheimer’s disease (AD) increases exponentially with age but there is limited knowledge of the modifiable risk factors for AD. However, there is growing evidence for possible dietary risk factors in the development of AD and cognitive decline with age, such as antioxidant nutrients, fish, dietary fats, and B-vitamins. Numerous animal and laboratory studies have shown that antioxidant nutrients can protect the brain from oxidative and inflammatory damage, but there are limited data available from epidemiological studies. There is more substantial epidemiological evidence from a number of recent studies that demonstrate a protective role of omega-3 fatty acids, such as docosahexaenoic acid, in AD and cognitive decline. This review will focus on epidemiological evidence investigating the relationship between nutrition and AD, focusing particularly on the roles of dietary fats and antioxidants.
Some observations on the c-wave of the electroretinogram in the intact frog eye

Abstract The electroretinogram of the intact, circulated frog eye was recorded d.c. with a total drift of less than 100 μV/hr. The time to peak of the c-wave is linearly related to the log relative energy of a flash delivered to a dark-adapted eye over at least 4 decades. In response to a stepofillumination, a slow vitreal positivity develops until the d.c.-electroretinogram attains a plateau voltage. When the light is extinguished, the voltage falls slowly in the dark, possibly reflecting the regeneration of bleached rhodopsin. These slow voltage changes (shifts in the “standing potential”) share conditions in common with the c-wave, namely, they are present only under conditions of apposition between photoreceptors and pigment epithelium. It is suggested that the c-wave in the frog eye is the slowly-rising phase of the standing potential which decrements because the light has been extinguished. Simultaneous recordings of the d.c.-electroretinogram and single dimming fibres (class IV ganglion cells) show a close correlation between the c-wave and the activity of these units. Experiments are described in support of the hypothesis that the transretinal current flow generated by means of an interaction between photoreceptors and pigment epithelium can transmit through the retina information related to photoreceptor sensitivity.
Morphology of the granular secretory glands in skin of poison-dart frogs (Dendrobatidae)

The granular glands of nine species of dendrobatid frogs were examined using light and electron microscopy. The glands are surrounded by a discontinuous layer of smooth muscle cells. Within the glands proper the secretory cells form a true syncytium. Multiple flattened nuclei lie at the periphery of the gland. The peripheral cytoplasm also contains mitochondria, rough surfaced endoplasmic reticulum, the Golgi apparatus, and an abundance of smooth endoplasmic reticulum. Centrally, most of the gland is filled with membrane-bound granules surrounded by amorphous cytoplasm. Few other organelles are found in this region. Early in the secretory cycle, the central part of the gland is filled with flocculent material which appears to be progressively partitioned off by membranes to form the droplet anlage. As granules form, the structure of the contents becomes progressively more vesicular. Dense vesicles, which bud off from the Golgi apparatus, fuse with the granular membrane during the development of granules, and might contain enzymes involved in toxin synthesis. The granules at this point resemble multivesicular bodies. Their structure is similar in all species of dendrobatid frogs even though the different frogs secrete substances of different chemical structure and toxicity.
TH‐A‐18C‐07: Noise Suppression in Material Decomposition for Dual‐Energy CT

Purpose: A general problem of dual-energy CT (DECT) is that the decomposition is sensitive to noise in the two sets of dual-energy projection data, resulting in severely degraded qualities of decomposed images. We have previously proposed an iterative denoising method for DECT. Using a linear decomposition function, the method does not gain the full benefits of DECT on beam-hardening correction. In this work, we expand the framework of our iterative method to include non-linear decomposition models for noise suppression in DECT. Methods: We first obtain decomposed projections, which are free of beam-hardening artifacts, using a lookup table pre-measured on a calibration phantom. First-pass material images with high noise are reconstructed from the decomposed projections using standard filter-backprojection reconstruction. Noise on the decomposed images is then suppressed by an iterative method, which is formulated in the form of least-square estimation with smoothness regularization. Based on the design principles of a best linear unbiased estimator, we include the inverse of the estimated variance-covariance matrix of the decomposed images as the penalty weight in the least-square term. Analytical formulae are derived to compute the variance-covariance matrix from the measured decomposition lookup table. Results: We have evaluated the proposed method via phantom studies. Using non-linear decomposition, our method effectively suppresses the streaking artifacts of beam-hardening and obtains more uniform images than our previous approach based on a linear model. The proposed method reduces the average noise standard deviation of two basis materials by one order of magnitude without sacrificing the spatial resolution. Conclusion: We propose a general framework of iterative denoising for material decomposition of DECT. Preliminary phantom studies have shown the proposed method improves the image uniformity and reduces noise level without resolution loss. In the future, we will perform more phantom studies to further validate the performance of the purposed method. This work is supported by a Varian MRA grant.
Getting Ready for School: Piloting Universal Prekindergarten in an Urban County

Investments in high-quality early care and education have been shown to reap societal benefits across the lives of the children served. A key intervention point is in the lives of 3- to 5-year olds during the period prior to entering kindergarten. Many jurisdictions have developed broad-based prekindergarten initiatives. This study reports on a pilot universal prekindergarten program in 24 sites in the Cleveland, Ohio area. Child assessment data were collected on 204 children from early care classrooms for 3- to 5-year olds across 3 time points by trained observers using 2 standardized instruments. Changes in achievement scores were shown to be significantly predicted by race, parental education level, and whether the family spoke English as a second language, with largest gains shown among children who were most behind at baseline. The findings serve to illuminate the developmental trajectory of children before kindergarten and how data can be used to inform practice and policy.
Gravitational lens theory

‘… imagine an observer, an isolated galaxy acting as a lens, and a quasar, nearly in a line. Two images would be formed on either side of the lens, and a third one would be formed near the center of the galaxy because the bending for central rays will be small.’ [Jerome Christian, in Physics Today, September 1980. ] This is an explanation of the gravitational lens effects that have been observed within the past year or so in images of a pair of quasars: 0957+561 A and B. The long-known Einsteinian idea of gravity bending light could presumably apply to the formation of a gravitational lens in space, so that light waves reaching a viewer on earth would be slightly bent and form secondary images that would fall on either side of the primary one, and thus there would only be an odd number of images.
Using formal specifications for functional validation of hardware designs

Formal specifications can help resolve both ambiguity issues and correctness problems in verifying complex hardware designs. This new methodology shows how specifications can also help design productivity by automating many procedures that are now done manually. Input sequences, output assertions, and a simulation coverage metric for the design under verification are all generated directly from the specification.
Mathematical theory for plant-herbivore systems

The interactions of host plants with herbivores can be mediated by factors other than population sizes or biomass alone. Recent evidence indicates that features of the vegetation (loosely termed “plant quality”) may change in response to herbivory and may, in turn, influence the performance of herbivores (i.e. by affecting survivorship, fecundity, or growth rates). A model which incorporates the effect of plant quality is presented. First it is shown that the frequency distribution of plant quality in the vegetation (p(q, t)) satisfies an equation of conservation. Then, qualitative aspects of the system are discussed in three situations: (1) mobile herbivores interacting with all plants; (2) sessile herbivores feeding exclusively on single plants; (3) intermediate situations in which mobility is moderate to low.
Outbreak investigation in a neonatal intensive care unit.

Outbreaks of healthcare-acquired infection can be devastating in neonatal intensive care units. Neonates are especially susceptible hosts because of prematurity of organ systems, low birth weight, and the use of invasive devices. This article outlines methodologies for infection surveillance and recognition of outbreak events. Principles of infection control in the neonatal intensive care unit are reviewed in reference to an outbreak setting, and a multidisciplinary team approach to developing a plant of action to halt the outbreak and find the source is discussed. Epidemiologic methods for determining the geographical extent and timeline of an outbreak, potential reservoirs or a common source of infection are reviewed.
Racial and ethnic differences in health insurance coverage for adults with diabetes.

OBJECTIVE: To evaluate the extent and types of health insurance coverage in a representative sample of adults with diabetes in the U.S. RESEARCH DESIGN AND METHODS: The Third National Health and Nutrition Examination Survey included national samples of non-Hispanic whites, non-Hispanic blacks, and Mexican-Americans aged > or = 20 years. Information on medical history and treatment of diabetes was obtained to determine subjects who had been diagnosed with diabetes by a physician before the survey (n = 1,503) and subjects without diagnosed diabetes (n = 17,319). Information on health insurance coverage was obtained via a structured questionnaire for 96% of participants. RESULTS: A total of 93% of all adults with diabetes had some form of health insurance. Of these subjects, 73% had private insurance, 48% had Medicare coverage, 15% had Medicaid coverage, and 5% had Champus/Veterans Affairs coverage. Approximately 52% of adults with diabetes had multiple types of health insurance, and 54% had health care coverage through one or more government-sponsored programs. A greater proportion of non-Hispanic whites (91%) and non-Hispanic blacks (89%) than Mexican-Americans (66%) had health insurance among subjects aged 20-64 years. For those aged > or = 65 years, coverage was virtually 100% for all racial and ethnic groups. Non-Hispanic whites had the highest rate of coverage through private insurance (81%), with non-Hispanic blacks having an intermediate rate (56%) and Mexican-Americans having the lowest rate (45%). Rates of coverage were similar for adults with and without diabetes in each racial and ethnic group for any type of insurance and for private insurance. CONCLUSIONS: There are marked racial and ethnic differences in health insurance coverage for adults with diabetes, although these differences are similar to those for adults without diabetes. Whether these racial and ethnic disparities influence access to care, quality of care, or health outcomes for people with diabetes remains to be determined.
Semistability at infinity, simple connectivity at infinity and normal subgroups

Abstract In this paper we prove the following two theorems about the behavior of the fundamental group near ∞ for certain group extensions. Theorem 1. If N ⩽ A ⩽ G are groups with A one-ended, finitely presented and of infinite index in G, G finitely presented, and N a non-locally finite normal subgroup of G, then G is semistable at ∞ . This is a technical result that should provide a useful tool in conjunction with semistability results already in the literature. Theorem 2. If 1 → H → G → K → 1 is a short exact sequence of infinite finitely generated groups with G finitely presented, K one-ended and H contained in a finitely presented subgroup L of infinite index in G then G is simply connected at ∞ . This is a generalization of a theorem of B. Jackson. Several applications of this result are discussed in the Introduction. Finally we construct a negative solution to a long standing problem in the form of a group extension 1 → H → G → K → 1 where H is a one-ended finitely generated group, G is the non-simply connected at ∞ group ( Z n ∗ Z ) × ( Z n ∗ Z ) and K is the (( n − 2)-connected at ∞) group Z n .
THE LIVING ARRANGEMENTS OF SEPARATED, WIDOWED, AND DIVORCED MOTHERS

When her marriage is disrupted a woman must make some decision about where to live. A basic component of residential choice is the decision whether to live alone as the head of a household, to move in with other relatives, or to share a household with nonrelatives. Such a choice is constrained by the availability of relatives, and by whether or not the woman can afford to live alone. The question of living arrangements is one important component of the economic status of women experiencing marital disruption, and the choice between heading a household or sharing someone else’s household influences the differential incidence among population subgroups of the female-headed family.
A computational framework for identifying design guidelines to increase the penetration of targeted nanoparticles into tumors

Targeted nanoparticles are increasingly being engineered for the treatment of cancer. By design, they can passively accumulate in tumors, selectively bind to targets in their environment, and deliver localized treatments. However, the penetration of targeted nanoparticles deep into tissue can be hindered by their slow diffusion and a high binding affinity. As a result, they often localize to areas around the vessels from which they extravasate, never reaching the deep-seeded tumor cells, thereby limiting their efficacy. To increase tissue penetration and cellular accumulation, we propose generalizable guidelines for nanoparticle design and validate them using two different computer models that capture the potency, motion, binding kinetics, and cellular internalization of targeted nanoparticles in a section of tumor tissue. One strategy that emerged from the models was delaying nanoparticle binding until after the nanoparticles have had time to diffuse deep into the tissue. Results show that nanoparticles that are designed according to these guidelines do not require fine-tuning of their kinetics or size and can be administered in lower doses than classical targeted nanoparticles for a desired tissue penetration in a large variety of tumor scenarios. In the future, similar models could serve as a testbed to explore engineered tissue-distributions that arise when large numbers of nanoparticles interact in a tumor environment.
Hybrid Speciation: Evolution under the microscope

Detailed genetic maps of three related sunflower species support the view that one species originated relatively recently from the other two by hybrid speciation, providing the first good evidence for this theory of speciation.
The 3D stress field at the intersection of a hole and a free surface

The author in this paper investigates the analytical stress field in the neighborhood of the intersection of a hole and a free boundary. Utilizing the form of a general 3D solution, which was constructed in a previous paper, he recovers the explicit displacement and stress fields in this neighborhood. Moreover, the analysis shows the complementary solution to be proportional to ϱα−-2, where α is independent of the Poisson's ratio ν. Interestingly enough the first root is exactly that obtained by the William's solution for a 90 deg corner with free-free of stress boundaries.
Measurement of kaonic X-rays from Al, Si, Ni and Cu☆

Abstract We have identified X-rays associated with stopped negative kaons in Al, Si, Ni and Cu. We report relative intensities, strong interaction energy shifts and strong interaction line broadenings. The measurements are found to be in good agreement with those predicted on the basis of a simple phenomenological potential except for the Ni (5 → 4) transition width.
Enveloping an iteration scheme

The problem of determining the optimal values of relaxation parameters for a linear iteration is solved. The optimal iteration scheme is achieved by a second-order linear iteration method.
Heterosis associated with regional crossbreeding between captive groups of rhesus macaques.

The lengths and weights of male and female Chinese-Indian hybrid rhesus macaques were compared with those of age- and sex-matched non-hybrid (Indian) controls to assess the occurrence of heterosis (hybrid vigor). Hybrid males and females had higher average, age-adjusted values of weight than nonhybrids. Hybrid males, but not females, also had a higher average, age-adjusted length than nonhybrids. These results are consistent with the hypothesis that regional crossbreeding of rhesus monkeys fosters heterosis.
Picosecond time-resolved fluorescence spectroscopy of phytochrome and stentorin

Phytochrome is a tetrapyrrole chromoprotein. It serves as a sensitive photosensor for red lightmediated gene expression and other developmental/morphological responses in plants. In this paper photochemical dynamics of the phytochrome molecule have been described in terms of photoisomerization of the tetrapyrrole chromophore in its singlet excited state and subsequent thermal processes in the Pr Pfr phototransformation of phytochrome. Stentorin acts as the photosensor molecule in the ciliate Stentor coeruleus. This unicellular protozoan is most sensitive to red light (610-620 urn). Stentor also senses the direction of light propagation as evidenced by their light-avoiding and negative phototactic swimming behaviors. This aneural photosensory phenomenon is triggered by the photoreceptor stentorin. The possible involvement of a light-induced transient proton release from the photoreceptor as the primary mechanism of light-signal processing has been discussed on the basis of picosecond fluorescence decays and time-resolved fluorescence spectra of stentorin in solution. An initial sensory signal generated by the primary photoprocess of stentorin then triggers subsequent transduction steps that include calcium ion influx from the extracellular medium. Calcium ion influx from the extracellular medium to the cytosol causes the Stentor cell to reverse its ciliary beating and subsequently steer away from the light trap. II.
On optimal strategies for a betting game

Abstract The game n-bet is to bet n times with each bet between 0 and 1 inclusive. To win the game means to have a specified positive integer m as the final result. If the probability of winning any bet is a constant p, then the strategy N(n,m) of betting 1 every time untilm is obtained is optimal when 0 1 2 , and is not always optimal when 1 2 .
Rates of manganese oxidation in aqueous systems

The rate of crystal growth of Mn3O4 (hausmannite) and βMnOOH (feitknechtite) in aerated aqueous manganous perchlorate systems, near 0.01 M in total manganese, was determined at pH levels ranging from 7.00 to 9.00 and at temperatures from 0.5 to 37.4°C. The process is autocatalytic, but becomes psuedo first-order in dissolved Mn2+ activity when the amount of precipitate surface is large compared to the amount of unreacted manganese. Reaction rates determined by titrations using an automated pH-stat were fitted to an equation for precipitate growth. The rates are proportional to surface area of oxide and degree of supersaturation with respect to Mn2+. The oxide obtained at the higher temperature was Mn3O4, but at 0.5° C only βMnOOH was formed. At intermediate temperatures, mixtures of these solids were formed. The rate of precipitation of hausmannite is strongly influenced by temperature, and that of feitknechtite much less so. The difference in activation energy may be related to differences in crystal structure of the oxides and the geometry of polymeric hydroxy ion precursors.
Counterexamples to a result of broemeling on simultaneous inferences for variance ratios of some mixed linear models

In a recent paper5 Broemeling (1978) extended his earlier work on one-sided confidence regions for the variance ratios of balanced random-effects models to the two-sided case. The extension depends on a probability Inequality which was claimed to be tru We show here that it is false, hence the proof of the main result given in Ms parer is in error W also show Lhat the ntatement of his result remains true in certain special cases.
Multiplexed assays for evaluation of Y-SNP markers in US populations

Abstract Genetic markers located on the Y chromosome are of increasing importance in human identity testing. In an effort to evaluate the forensic utility of Y chromosome single nucleotide polymorphism (SNP) markers, we constructed several novel multiplex allele-specific primer extension (ASPE) assays and utilized a new commercial allele-specific hybridization (ASH) multiplex kit to examine 50 Y-SNP markers in 229 males from two US Caucasian and African American populations. The novel ASPE assays covered 18 Y-SNP markers in three multiplex reactions while a commercial ASH kit was used to type 42 Y-SNPs plus amelogenin for sex-typing purposes. There were 10 overlapping loci between the ASPE and ASH methods permitting an evaluation of concordance on over 2000 allele calls. The 50 Y-SNP markers examined in this study define 45 of the 159 possible Y Chromosome Consortium (YCC) haplogroups. Only 18 different haplogroups were observed in our samples.
Banded matrix iterative approach to Monte-Carlo simulations of scattering of waves by large-scale random rough surface problems: TM case

A banded matrix iterative approach is applied to study the scattering of a TM incident wave from a perfectly conducting one-dimensional random rough surface. It is accurate and is much faster than the full matrix inversion approach or the conjugate gradient method. Applications of this method to large-scale rough surface problems are illustrated.
Dynamic Integration of Task-Relevant Visual Features in Posterior Parietal Cortex

Summary The primate visual system consists of multiple hierarchically organized cortical areas, each specialized for processing distinct aspects of the visual scene. For example, color and form are encoded in ventral pathway areas such as V4 and inferior temporal cortex, while motion is preferentially processed in dorsal pathway areas such as the middle temporal area. Such representations often need to be integrated perceptually to solve tasks that depend on multiple features. We tested the hypothesis that the lateral intraparietal area (LIP) integrates disparate task-relevant visual features by recording from LIP neurons in monkeys trained to identify target stimuli composed of conjunctions of color and motion features. We show that LIP neurons exhibit integrative representations of both color and motion features when they are task relevant and task-dependent shifts of both direction and color tuning. This suggests that LIP plays a role in flexibly integrating task-relevant sensory signals.
Unsteady Hydrofoils: Theoretical and Computational Analysis

In this paper the computational problem examined is the impulsive start of a two-dimensional flat-plate hydrofoil at a fixed angle of attack. The method applied is an equally-spaced lumped-vortex panel method. The results from a lumped-vortex wake model and a shed-vortex sheet wake model are reported. Comparisons with the linear theory of Wagner (1925), the theoretical results associated with the single lumped-vortex wake model and the full wake model are presented. In addition, it is shown that the computational predictions are consistent with results reported by Katz and Plotkin (2001); they applied a distribution of vortices to model the wake. In the present paper the importance of resolving the chordwise pressure distribution in unsteady hydrofoil problems is elucidated. New predictions of both the evolution of lift and induced drag are reported for the instantaneously started flat plate. The computational predictions are compared with theorecticalpredictions also discussed in this paper.Copyright © 2013 by ASME
Effect of wave boundary layer on sea-to-air dimethylsulfide transfer velocity during typhoon passage

Abstract A full-spectral third-generation ocean wind–wave model (Wavewatch-III) implemented in the South China Sea is used to investigate the effects of the wave boundary layer on the drag coefficient and the sea-to-air transfer velocity of dimethylsulfide (DMS) during passage of Typhoon Wukong (September 5–11, 2000) with a maximum sustained wind speed of 38 m s− 1. The model is driven by the reanalyzed surface winds (1° × 1°, four times daily) from the National Centers for Environmental Prediction. It is found that the wave boundary layer evidently enhances (16.5%) the drag coefficient (in turn increases the momentum flux across the air–sea interface), and reduces (13.1%) the sea-to-air DMS transfer velocity (in turn decreases the sea-to-air DMS flux). This indicates the possibility of important roles of wave boundary layer in atmospheric DMS contents and global climate system.
Simultaneous LC–MS/MS quantification of P-glycoprotein and cytochrome P450 probe substrates and their metabolites in DBS and plasma

Background: An LC–MS/MS method has been developed for the simultaneous quantification of P-glycoprotein (P-gp) and cytochrome P450 (CYP) probe substrates and their Phase I metabolites in DBS and plasma. P-gp (fexofenadine) and CYP-specific substrates (caffeine for CYP1A2, bupropion for CYP2B6, flurbiprofen for CYP2C9, omeprazole for CYP2C19, dextromethorphan for CYP2D6 and midazolam for CYP3A4) and their metabolites were extracted from DBS (10 µl) using methanol. Analytes were separated on a reversed-phase LC column followed by SRM detection within a 6 min run time. Results: The method was fully validated over the expected clinical concentration range for all substances tested, in both DBS and plasma. The method has been successfully applied to a PK study where healthy male volunteers received a low dose cocktail of the here described P-gp and CYP probes. Good correlation was observed between capillary DBS and venous plasma drug concentrations. Conclusion: Due to its low-invasiveness, simple sample collection and minimal sample preparation, DBS represents a suitable method to simultaneously monitor in vivo activities of P-gp and CYP.
The Social Context of Middle School: Teachers, Friends, and Activities in Montessori and Traditional School Environments.

Abstract This study compared the time use and perceptions of schools, teachers, and friends of approximately 290 demographically matched students in Montessori and traditional middle schools. We used the Experience Sampling Method (ESM) and questionnaires and conducted multivariate analyses showing that the Montessori students (a ) reported more positive perceptions of their school environment and their teachers, and (b ) more often perceived their classmates as friends while at school. ESM time estimates suggested that the 2 school environments were also organized in different ways: Montessori students spent more time engaged with school‐related tasks, chores, collaborative work, and individual projects; traditional students spent more time in social and leisure activities and more time in didactic educational settings (e.g., listening to a lecture, note taking, watching instructional videos). These results are discussed in terms of current thought on motivation in education and middle school reform.
Field-flow fractionation: analysis of macromolecular, colloidal, and particulate materials

Field-flow fractionation (FFF) is a family of flexible elution techniques capable of simultaneous separation and measurement. Its sample domain extends across a broad macromolecular-colloidal-particulate continuum from about 1 nanometer to more than 100 micrometers and incorporates both simple and complex macromaterials of biological, biomedical, industrial, and environmental relevance. Complex materials are separated into components to simplify measurement. Component properties measurable by FFF include mass, size, density, charge, diffusivity, and thickness of adsorbed layers. When characterization by these properties is inadequate, other measurement tools can be readily coupled to FFF, either off-line or on-line, by virtue of its flow-elution operation. This article describes the principles and major subtechniques of the FFF family along with application of its measurement and separative capabilities.
Effect of optical phonon scattering on the performance limits of ultrafast GaN transistors

As GaN HEMTs are scaled down to push performance into 100's of GHz range, it is timely to investigate their performance limits. Unlike Si MOSFETs and most other III–V semiconductor based HEMTs, the electron - polar optical phonon interaction is exceptionally strong in GaN. As a result, the mean free path of hot electrons in GaN is λ op ∼ 3.5nm, far shorter than typical HEMT gate lengths (L g ). Thus while Si MOSFETs and other III-V HEMTs can approach near ballistic behavior by reduction of parasitic delays and L g , the situation is starkly different for GaN HEMTs. Here, we investigate the intrinsic performance limits of GaN HEMTs by incorporating the effect of polar optical phonon backscattering into a quasi-ballistic model. Then, we include parasitic elements and quantitatively investigate the degradation in performance. The method used is semi-analytical, and will prove very helpful in designing future generations of devices. The work not only sets a roadmap for scaling to high speeds, it also offers clear physical reasons for a number of unexplained features observed in state-of-the-art GaN HEMTs.