cssi/SciSciGPT-SciSciNet huggingface dataset:
Amarts: A class of asymptotic martingales a. Discrete parameter

A sequence (Xn) of random variables adapted to an ascending (asc.) sequence Fn of σ-algebras is an amart iff EXτ converges as τ runs over the set T of bounded stopping times. An analogous definition is given for a descending (desc.) sequence Fn. A systematic treatment of amarts is given. Some results are: Martingales and quasimartingales are amarts. Supremum and infimum of two amarts are amarts (in the asc. case assuming L1-boundedness). A desc. amart and an asc. L1-bounded amart converge a.e. (Theorem 2.3; only the desc. case is new). In the desc. case, an adapted sequence such that (EXτ)τ∈T is bounded is uniformly integrable (Theorem 2.9). If Xn is an amart such that supnE(Xn − Xn−1)2 < ∞, then Xnn converges a.e. (Theorem 3.3). An asc. amart can be written uniquely as Yn + Zn where Yn is a martingale, and Zn → 0 in L1. Then Zn → 0 a.e. and Zτ is uniformly integrable (Theorem 3.2). If Xn is an asc. amart, τk a sequence of bounded stopping times, k ≤ τk, and E(supk |Xτk − Xk−1|) < ∞, then there exists a set G such that Xn → a.e. on G and lim inf Xn = −∞, lim sup Xn = +∞ on Gc (Theorem 2.7). Let E be a Banach space with the Radon-Nikodym property and separable dual. In the definition of an E-valued amart, Pettis integral is used. A desc. amart converges a.e. on the set {lim sup ‖Xn‖ < ∞}. An asc. or desc. amart converges a.e. weakly if supT E‖Xτ‖ < ∞ (Theorem 5.2; only the desc. case is new).
Blood is thicker than lymph

Growth of blood and lymphatic vessels is essential in the developing embryo and in the pathogenesis of human diseases such as cancer, but the signaling pathways that regulate vessel growth and function are not yet well characterized. In this issue of the JCI, studies by Fritz-Six et al. and Ichikawa-Shindo et al. demonstrate that loss of signaling by the adrenomedullin peptide results in embryonic edema and death (see the related articles beginning on pages 40 and 29, respectively). Remarkably, this phenotype is attributed to defects in lymphatic vessels by one group and to defects in blood vessels by the other. In addition to defining what I believe to be a novel angiogenic signaling pathway, these studies demonstrate the intricate molecular, genetic, and physiologic relationships between blood and lymphatic vessels that must be considered by investigators of vascular biology.
On logarithmic Sobolev constant for diffusion semigroups

Abstract This paper is concerned with estimates for the constant in the logarithmic Sobolev inequality. As an application, we show that for the Laguerre semigroup with the generator xD 2 − ( x − λ ) D , the logarithmic Sobolev constant α λ satisfies log (3 + 6 λ )/ log 3 ⩽ α λ ⩽ 16 log (3 + 6 λ ) for 0 1 2 and α λ = 4 for 1 2 ⩽ λ .
Level of in utero cocaine exposure and neonatal ultrasound findings.

Whether in utero cocaine exposure among term infants is associated independently with a higher risk of brain lesions visible on perinatal ultrasound is not clearly established. Dixon and Bejar1 reported a sevenfold increase of ultrasound lesions in general and a twofold increase of subependymal hemorrhage in the caudothalamic groove at the level of the head of the caudate when term, African-American, cocaine-exposed infants were compared with Hispanic unexposed infants. These findings were partially confirmed by others in samples of unspecified ethnicity.2,3 Investigators working with predominantly African-American samples have not found increased risk of any ultrasound findings associated with in utero cocaine exposure.4–7 Women who use cocaine during pregnancy are more likely (than those who do not) to use cigarettes, alcohol, marijuana, and other illicit drugs8 that also may be associated with ultrasound-detected lesions.9 None of the studies correlating cocaine exposure with neonatal ultrasound-detected lesions have controlled for more than one of these substances;1–3 therefore, misattribution to cocaine of the effects of other psychoactive substances has not been ruled out. Before perinatal cocaine use became epidemic, Hayden and colleagues10 noted that nearly 5% of clinically well, term infants show sonographic abnormalities, of which subependymal hemorrhage in the caudothalamic groove is the most common. Vaginally delivered, small for gestational age, African-American infants were at greater risk for these lesions in that sample. Because illegal drug use during pregnancy is detected disproportionately by clinicians among African-American women11 and often is associated with infants who are small for gestational age,12 an increase in lesions associated with cocaine use is difficult to interpret without controlling for ethnicity and birth weight for gestational age. Finally, the issue of possible effects of the level of prenatal cocaine exposure has emerged recently in work demonstrating a dose-response relationship of heavier exposure to less optimal neonatal anthropometric parameters and infant behaviors.13–17 The goal of the current analysis was to assess whether there is an association between the level of in utero cocaine exposure and findings on neonatal cranial ultrasound, when potentially confounding variables are controlled statistically.
Representation of ideal figure size in Ebony magazine: a content analysis.

Abstract Studies examining trends over time in mainstream magazines observe decreases in women's figure size, and increases in figure exposure and amount of diet/exercise content. Little is known, however, regarding the content of African American magazines. Utilizing methods from classic studies, this investigation examined content in Ebony , a magazine with wide African American readership, from 1969 to 2008. We included the full content of N = 462 issues, with a total of N = 539 cover images of women, of which N = 208 were full-body shots. Analyses indicated a curvilinear relationship between time and figure exposure, with a recent trend toward more full-body shots, similar to mainstream magazines. Contrary to previous studies, however, the majority of figures across time were average size, and a curvilinear relationship between time and diet/exercise content showed peak content in the early 1990s. Results are considered in context of research indicating African American women show less body dissatisfaction than other racial/ethnic groups.
Resident physicians' knowledge of breastfeeding and infant growth.

Background: It is well documented that breastfed infants grow differently from formula-fed infants. The purpose of this study was to assess resident physicians' knowledge of breastfeeding and infant growth.Methods: A cross-sectional, self-adminis- tered survey was administered to family medicine and pediatric resident physicians from three large, hospital-based public and private programs in North Carolina. Results: One hundred and seven (46%) of 235 residents completed the study, representing 55 percent of family medicine residents and 39 percent of pediatric residents. Ninety-nine percent of participants reported frequently or always plotting infant growth at well-child visits. None reported plotting breastfed babies on a chart specific to breastfeeding. Only 5 percent of participants knew that breastfed infants grew at a slower velocity than formula-fed infants after 4 months of age. This knowledge was not significantly related to specialty, year of training, or gender; it was significantly related to breastfeeding experience ( p < 0.04). Of the residents who did not have personal experience with breastfeeding, 99 percent answered incorrectly compared with 88 percent of those who had some personal experience in breastfeeding. Conclusions: In this sample of family medicine and pediatric residents, almost all were unaware that breastfed infants grow at slower rates after 4 months of age. Since the frequency of breastfeeding is increasing in the United States, it is important that physicians be able to monitor the growth of breastfed infants accurately and provide expert counseling for breastfeeding mothers. (BIRTH 27:1, March 2000)
Disability Prototypes in the United States and the Russian Federation: An International Comparison

The purpose of this cross-cultural research is to examine prototypical perspectives about disability groups in the United States and Russia by extending the research on disability prototypes that w...
Quantum Dynamics of a Nonlinear Birefringent Model with Anticorrelated Field States

Abstract In this paper, anticorrelated field states with a binomial distribution over orthogonal polarizations, interacting with a nonlinear birefringent medium, are discussed. The field states are the SU(2) coherent states, where the angular momentum operators are realized as bilinear products of the boson operators associated with the two polarizations. The system discussed here provides an optical realization of a nonlinear rotator. We study the quantum dynamics of the statistical properties of the field and the evolution of the degree of polarization.
Double-pulse defibrillation using pulse separation based on the fibrillation cycle length.

Double-Pulse Defibrillation Using FCL, Introduction: We investigated a method of defibrillation in which two shocks were delivered to the same electrodes with a separation hazed on the cycle length of the fibrillation event (FCL). Methods and Results: In pentobarbital anesthetized dogs, a computerized system determined the FCL from the fibrillation event, computed the desired double-pulse (DP) shock separation, and immediately delivered the DP shocks. In group 1, energy for 50% success at defibrillation (E50) was measured using separations from 55% to 95% of the FCL and remeasured after administration of flecainide, clofilium, or vehicle to change the FCL. Both drugs increased 1(1 by = 25%. Plots of E50 versus %FCL aligned before and after drug showed that the optimum pulse separation followed the FCL. In group 2, E50s were measured for 55% to 185% FCL separations in clofilium or vehicle-treated animals. The optimum DP £50 was at 85% FCL and was not significantly different from the single-shock E50. In group 3, no differences were found when comparing the probability of success versus total energy relationships for single and optimum DP shocks. Group 4 compared E50s for single and DP shocks using a single-catheter configuration and three-electrode configurations (catheter-subdermal patch). E50s for single and DP shocks were equal using the single-catheter configuration but DP shocks required = 20% more energy in the three-electrode configurations. Conclusion: In single-pathway lead configurations, two shocks with 85% FCL separation can be reliably combined to defibrillate using the same total energy as a larger single shock. Since the energy is unchanged but the total duration is doubled, DP shock currents are reduced by 20% to 30%.
Asymptotics for Analysis of Variance When the Number of Levels is Large

Abstract We study asymptotic results for F tests in analysis of variance models as the number of factor levels goes to ∞ but the number of observations for each factor combination is fixed. Asymptotic derivations of the type discussed in this article would be relevant whenever both the numerator and denominator degrees of freedom go to ∞ (at the same rate). We consider null and alternative distributions of F, the usual F statistic, for fixed-effects and random-effects, balanced and unbalanced, one-way and two-way, and normal and nonnormal analysis of variance (ANOVA) models. The results may be most relevant for random-effects and mixed models. For example, we may have an agricultural experiment in which the number of cows is quite large but the number of measurements on each cow is small. The results would also be relevant for fixed-effects models in which there are many factor levels but not many observations for each factor level.
Mobile cloud computing service models: a user-centric approach

Mobile devices are rapidly becoming the major service participants nowadays. However, traditional client-server based mobile service models are not able to meet the increasing demands from mobile users in terms of services diversity, user experience, security and privacy, and so on. Cloud computing enables mobile devices to offload complex operations of mobile applications, which are infeasible on mobile devices alone. In this article, we provide a comprehensive study to lay out existing mobile cloud computing service models and key achievements, and present a new user-centric mobile cloud computing service model to advance existing mobile cloud computing research.
Mitochondrial dysfunction is a common phenotype in aging and cancer

An interesting clue with regard to molecular mechanisms underlying age-associated cancers is the apparent defect in mitochondrial function. Recent studies demonstrate a progressive decline in mitochondrial function during aging. Studies have established that the decline in mitochondrial function is due to the accumulation of mutations in mitochondrial DNA. These observations suggest that the mitochondrial dysfunction that accompanies aging may exert a major influence on carcinogenesis.
Effect of oral and intravenous heparin tetrasaccharide on allergic airway responses: critical role of N-sulfation.

We have shown that inhaled heparin (hep) oligosaccharides attenuate allergic airway responses in sheep and that this anti-allergic activity resides in a tetrasaccharide sequence. Here we determined: (a) the anti-allergic activity of oral and intravenous hep-tetrasaccharide on allergic airway responses in the sheep model of asthma; and (b) the role of N-sulfation in mediating this anti-allergic activity. Ascaris suum-induced early (EAR) and Late (LAR) airway responses and airway hyperresponsiveness (AHR) to carbachol were measured in allergic sheep without and after treatment with different doses of oral or intravenous hep-tetrasaccharide. At doses of 0.06 mg/kg, 0.125 mg/kg, and 0.25 mg/kg, oral hep-tetrasaccharide caused a dose-dependent inhibition of EAR and LAR. Post-antigen AHR was also inhibited dose dependently. The same doses of intravenous hep-tetrasaccharide yielded comparable inhibition of EAR, LAR and AHR, confirming that orally delivered hep-tetrasaccharide has good bioavailability. The protection by hep-tetrasaccharide on EAR and LAR was dependent on N-sulfation, as N-desulfated/N-acetylated tetrasaccharide had a markedly reduced effect. However, inhibition of the post-antigen AHR was independent of N-sulfation. These results demonstrate that orally administered hep-tetrasaccharide inhibits allergic airway responses in the sheep model of asthma. Hep-tetrasaccharide has good oral bioavailability and its anti-allergic activity is critically dependent on N-sulfation of the glucosamine ring.
Microtubule Involvement in the Adaptation to Altered Mechanical Load in Developing Chick Myocardium

Mechanical load regulates ventricular growth, function, and structure from the earliest stages of cardiac morphogenesis through senescence. Dramatic changes in cardiac form and function have been defined for developing cardiovascular systems, and changes in mechanical loading conditions can produce structural malformations such as left heart hypoplasia. To date, relatively little is known regarding the interactions between changes in mechanical load, morphogenesis, and the material properties of the embryonic heart. We tested the hypothesis that passive material properties in the embryonic heart change in response to altered mechanical load and that microtubules play an important role in this adaptive response. We measured biaxial passive stress-strain relations in left ventricular (LV) myocardial strips in chick embryos at Hamburger-Hamilton stage 27 following left atrial ligation (LAL) at stage 21 to reduce LV volume load and create left heart hypoplasia. Following LAL, myocardial stresses at given strains and circumferential stiffness increased versus control strips. Western blot analysis of LAL embryos showed an increase in both total and polymerized β-tubulin and confocal microscopy confirmed an increase in microtubule density in the LV compact layer versus control. Following colchicine treatment, LV stresses and stiffness normalized in LAL specimens and microtubule density following colchicine was similar in LAL to control. In contrast, Taxol treatment increased myocardial stresses and stiffness in control strips to levels beyond LAL specimens. Thus, the material properties of the developing myocardium are regulated by mechanical load and microtubules play a role in this adaptive response during cardiac morphogenesis.
Quantitative analysis of follicle‐stimulating hormone receptor in ovarian epithelial tumors: A novel approach to explain the field effect of ovarian cancer development in secondary mullerian systems

The role of FSHR expression in ovarian cancer development is not clear. We examined quantitative expression of FSHR in different types of OET, presumed precursor lesions and peritoneal implants and further discussed FSH as a key growth-promotion factor for the process of ovarian epithelial tumorigenesis. Thirty-five primary OET specimens, including 5 serous cystadenomas, 4 papillary serous cystadenomas, 9 SBTs and 17 serous carcinomas, were examined for quantitative FSHR expression. Ten paired samples (3 benign cystadenomas, 5 SBTs and 2 carcinomas) were obtained from several morphologically different areas, including benign-looking, borderline and cancerous areas in the same OETs, and from the remaining ovarian tissue and contralateral ovaries. Competitive RT-PCR was performed to measure the quantitative expression of FSHR in each tissue sample. FSHR expression levels were compared among nonpaired samples and within paired samples. We found that OSE had the lowest FSHR expression, whereas antral follicles had the highest level. Within benign OETs, papillary serous cystadenomas have 4.9-fold higher FSHR levels than nonpapillary serous cystadenomas. SBTs had the highest level of FSHR expression, which was 12.8-fold, 2.7-fold and 2.4-fold higher than that of serous cystadenomas, papillary serous cystadenomas and grade 1 carcinomas, respectively. A similarly high level of FSHR mRNA was found in peritoneal implants, which were associated with SBTs. FSHR levels among serous carcinomas decreased with an increase in carcinoma grade. Grade 3 carcinomas had the lowest FSHR level, which was similar to that of serous cystadenomas, while grade 1 carcinomas had 6.5-fold higher FSHR levels than those in serous cystadenomas. Our results suggest that not only serum FSH but also FSHR in ovarian epithelium may play important roles in ovarian OET development. Both the receptor and ligand may act in a synergistic way to promote tumor growth. The observation that high FSHR levels are present in peritoneal implants suggests that FSH may also play a similar role in the development of peritoneal serous tumors. From this perspective, circulating FSH may be considered a driving force in the field effect theory for the development of both ovarian neoplasms and their associated peritoneal implants. However, the exact role of FSH and/or FSHR in the development of epithelial tumors arising in both the ovary and peritoneum needs further investigation.
Mother knows best

New findings confirm the transforming potential of KSHV and pinpoint the active components of hCG used to treatKaposi's sarcoma (pages 428–440).
Electron-Rich Oxoruthenium(IV) Cleavage Agents: A Zero-Order Rate Law for DNA Catalysis.

A new family of oxoruthenium(IV) complexes based on [(DAMP)(L)RuO]2+ have been prepared where DAMP = 2,6-bis((dimethylamino)methyl)pyridine and L = 2,2‘-bipyridine (bpy), 1,10-phenanthroline (phen), or dipyridophenazine (dppz). The structures of [(DAMP)(bpy)RuO]2+ and [(DAMP)(phen)RuO]2+ were determined by X-ray crystallography. The Ru−O bond lengths (1.805(3) and 1.814(4) A, respectively) are indicative of multiple bonding, as expected for oxoruthenium(IV), and clear steric protection of the RuO moiety is provided by the DAMP ligand. Cyclic voltammetry shows that the tertiary amine functionalities of the DAMP ligand stabilize both the RuIVO2+ and RuIIIOH2+ redox forms relative to other (polypyridyl)oxoruthenium(IV) complexes. As a result, the oxidations of both sec-phenylethanol and trans-stilbene are ∼100 times slower for [(DAMP)(bpy)RuO]2+ than for [(bpy)2(py)RuO]2+. Accordingly, the reaction mechanisms involve oxidation of substrate only by the RuIVO2+ form with no contribution from direct oxidation b...
Interactions of a streamwise-oriented vortex with a finite wing

A canonical study is developed to investigate the unsteady interactions of a streamwise-oriented vortex impinging upon a finite surface using high-fidelity simulation. As a model problem, an analytically defined vortex superimposed on a free stream is convected towards an aspect-ratio-six ( ) plate oriented at an angle of and Reynolds number of in order to characterize the unsteady modes of interaction resulting from different spanwise positions of the incoming vortex. Outboard, tip-aligned and inboard positioning are shown to produce three distinct flow regimes: when the vortex is positioned outboard of, but in close proximity to, the wingtip, it pairs with the tip vortex to form a dipole that propels itself away from the plate through mutual induction, and also leads to an enhancement of the tip vortex. When the incoming vortex is aligned with the wingtip, the tip vortex is initially strengthened by the proximity of the incident vortex, but both structures attenuate into the wake as instabilities arise in the pair’s feeding sheets from the entrainment of opposite-signed vorticity into either structure. Finally, when the incident vortex is positioned inboard of the wingtip, the vortex bifurcates in the time-mean sense with portions convecting above and below the wing, and the tip vortex is mostly suppressed. The time-mean bifurcation is actually a result of an unsteady spiralling instability in the vortex core that reorients the vortex as it impacts the leading edge, pinches off, and alternately attaches to either side of the wing. The increased effective angle of attack inboard of impingement enhances the three-dimensional recirculation region created by the separated boundary layer off the leading edge which draws fluid from the incident vortex inboard and diminishes its impact on the outboard section of the wing. The slight but remaining downwash present outboard of impingement reduces the effective angle of attack in that region, resulting in a small separation bubble on either side of the wing in the time-mean solution, effectively unloading the tip outboard of impingement and suppressing the tip vortex. All incident vortex positions provide substantial increases in the wing’s lift-to-drag ratio; however, significant sustained rolling moments also result. As the vortex is brought inboard, the rolling moment diminishes and eventually switches sign as the reduced outboard loading balances the augmented sectional lift inboard of impingement.
An evaluation of the solubility of sulfide sulfur in silicate melts from experimental data and natural samples

Abstract An evaluation of the solubility of sulfur in silicate melts from experimental data obtained under a wide variety of experimental conditions has been undertaken. Under reducing conditions (fO2 below QFM), sulfur is present as sulfide (−II oxidation state), and precipitates as pyrrhotite or an FeSO sulfide phase when the sulfur concentration in the silicate melt is sufficiently high. The basic solubility reaction is: 1 2 S 2(g) +O 2− (silicate melt) ⇌ 1 2 O 2(g) +S 2− ( silicate melt) For silicate melts with high FeO contents (> 10 wt.% FeO), sulfur dissolves as an Fe3SO2 (or 2FeO·FeS) species. When saturated with pyrrhotite: FeS (sulfide melt) +2FeO (silicate melt) ⇌Fe 3 SO 2(silicate melt) log K=log X s − 21ogX FeO =−0 .8 (at 1200°C, 1 bar) Under saturated and unsaturated conditions: 1 2 S 2(g) +3FeO (silicate melt) ⇌Fe 3 SO 2(silicate melt) +> 1 2 O 2(g) log K=log X s + 1 2 1og ƒ O 2 − 3 log X FeO − 1 2 logƒ S 2 =−4.1 (at 1200°C, 1 bar) log K also shows a positive pressure dependence (= +0.1 per kbar). For silicate melts with low FeO contents ( FeS (sulfide melt) + O 2− (silicate melt) ⇌FeO (silicate melt) + S 2− (silicate melt) log K=log X s + log X FeO = −5.8 (9007ndash;1000°C, 1–6 kbar) For silicate melts with intermediate FeO contents (1–10 wt% FeO), the behavior of sulfur is more complex, with sulfur probably present as an FeS species: FeS (sulfide melt) ⇌FeS (silicate melt) log K=log X s = −1.05–3000/T (K) (850–1200°C, 1 bar–2.2 kbar) The effects of temperature, pressure, melt composition and other experimental conditions have been assessed. The ability to predict the solubility of sulfur in silicate melts has implications for the formation of ore deposits associated with igneous systems. Application of the results to natural systems shows that some samples have a concentration of sulfur higher than that which could have been dissolved in the silicate melt, indicating that the magma carried excess sulfur, and/or sulfur has been added after crystallization of the magma.
Strategies for addressing climate change: Policy perspectives from around the world

Abstract The greenhouse effect is intrinsically global. Accordingly, effective responses require global coordination. While limited policies have been adopted, notably for phasing out chlorofluorocarbons, there is no clear consensus as to what to do about other greenhouse gases. In this paper, we survey attitudes and policy responses among the nations of the world. Public opinion surveys are consistent in showing that considerable sensitivity to environmental issues exists virtually everywhere. On the other hand, there is acute awareness that other issues, especially economic development, can conflict with global climate-change mitigation goals. In such a state of uncertainty there is a strong argument to be made for implementing policies which are good ideas independent of greenhouse-gas considerations. There is also good reason to expand research. What is feasible depends strongly on present and changing attitudes of the citizens of the world, and of their governments. It is thus critical to follow closely the evolution of attitudes. The kind of work summarized in this paper needs to be updated on a continuing basis, and the results made available routinely to the global policy community. We conclude our review with several recommendations for research designed specifically to reduce uncertainty about costs and institutional issues relating to responses to global climate change.
Cytoprotective Effects of a Cyclic RGD Peptide in Steatotic Liver Cold Ischemia and Reperfusion Injury

The serious need for expanding the donor population has attracted attention to the use of steatotic donor livers in orthotopic liver transplantation (OLT). However, steatotic livers are highly susceptible to hepatic ischemia–reperfusion injury (IRI). Expression of fibronectin (FN) by endothelial cells is an important feature of hepatic response to injury. We report the effect of a cyclic RGD peptide with high affinity for the α5β1, the FN integrin receptor, in a rat model of steatotic liver cold ischemia, followed by transplantation. RGD peptide therapy ameliorated steatotic IRI and improved the recipient survival rate. It significantly inhibited the recruitment of monocyte/macrophages and neutrophils, and depressed the expression of pro-inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and interferon (IFN)-γ. Moreover, it resulted in profound inhibition of metalloproteinase-9 (MMP-9) expression, a gelatinase implied in leukocyte migration in damaged livers. Finally, we show that RGD peptide therapy reduced the expression of the 17-kDa active caspase-3 and the number of apoptotic cells in steatotic OLTs. The observed protection against steatotic liver IRI by the cyclic RGD peptides with high affinity for the α5β1 integrin suggests that this integrin is a potential therapeutic target to allow the successful utilization of marginal steatotic livers in transplantation.
Smoke, Wind, and That Journey Upwards: Augustinian Reflections on the Role of Humility in Virtue Formation.

Augustine’s training in pagan rhetoric, his classical education, and the productive tensions he experienced between pagan and Christian exemplars played a formative role in his spiritual journey. An examination of the generative aspects of these encounters with otherness yields insights for our own understanding, not just of the importance to ethical formation of loyalty to community and tradition, but also of reason-giving practices that extend across communities—practices that thrive when cultivated with Augustinian humility. Turning to Augustine can help us transcend the divide between traditionalist defenders of ‘‘character education’’ and liberal defenders of critical reflection and autonomy.
Age and diet of fossil California condors in Grand Canyon, Arizona

A dozen new radiocarbon dates, together with a thorough review of its fossil distribution, shed new light on the time and probable cause of extinction of the California condor, Gymnogyps californianus, in Grand Canyon, Arizona. The radiocarbon data indicate that this species became extinct in Grand Canyon, and other parts of the inland West, more than 10,000 years ago in coincidence with the extinction of megafauna (proboscidians, edentates, perissodactyls). That condors relied on the megafauna for food is suggested by the recovery of food bones from a late Pleistocene nest cave in Grand Canyon. These fossil data have relevance to proposed release and recovery programs of the present endangered population of California condors.
Edge Weight Reduction Problems in Directed Acyclic Graphs

LetGbe a weighted directed acyclic graph in which edge weights are not static quantities, but can be reduced for a certain cost. In this paper we consider the problem of determining which edges to reduce so that the length of the longest paths is minimized and the total cost associated with the reductions does not exceed a given cost. We consider two types of edge reductions, linear reductions and 0/1 reductions, which model different applications. We present efficient algorithms for different classes of graphs, including trees, series?parallel graphs, and directed acyclic graphs, and we show other edge reduction problems to be NP-hard.
Response of neoplastic and normal vasculature to acetylcholine.

Abstract Intravascular acetylcholine causes vasodilatation and an increase in normal tissue blood flow and could reasonably be expected to increase blood flow in malignant neoplasms. In this study using the microsphere reference sample technique, however, blood flow of V2 carcinoma, implanted in several organ sites in rabbits, was found to decrease after both an intra-arterial bolus and infusion of acetylcholine chloride. Cardiac output was not significantly changed. These observations may explain the recent report by Marincek et al. of a decrease in CT X-ray absorption in renal neoplasms after acetylcholine and previous reports of the lack of utility of vasodilators in improving the diagnosis of malignant neoplasms after arteriography.
PBL 2.0: enhancing problem-based learning through increased student participation

Purpose: The purpose of this study was to test a new problem-based learning (PBL) method to see if it reinvigorated the learning experience. Method: A new PBL format called PBL 2.0, which met for 90 min two times per week, was introduced in 2009 into an 11-week integrated neuroscience course. One hundred second-year medical students, divided into 10 groups of 10, who had completed their first year of medical school using a traditional PBL format, participated in PBL 2.0. Students were prohibited from using computers during the first session. Learning objectives were distributed at the end of the first day to the small groups, and students were assigned to pairs/trios responsible for leading an interactive discussion on specific learning objectives the following day. Student-led ‘lectures’ were prohibited. All students were responsible for learning all of the learning objectives so that they could participate in their discussions. Results: One hundred and six students were surveyed and 98 submitted answers (92% response). The majority of groups adhered to the new PBL method. Students invested more time preparing the learning objectives. Students indicated that the level of interaction among students increased. The majority of students preferred the new PBL format. Conclusions: PBL 2.0 was effective in increasing student interaction and promoting increased learning. Keywords: problem-based learning; learning strategies; medical education; problem solving; critical thinking; problem-based curriculum (Published: 11 June 2012) Citation: Med Educ Online 2012, 17 : 17375 - http://dx.doi.org/10.3402/meo.v17i0.17375
Pregnancy testing in women of reproductive age in US emergency departments, 2002 to 2006: assessment of a national quality measure.

Study objective We assess performance and explore definitions for a new emergency department (ED) quality measure: the proportion of women aged 14 to 50 years who have abdominal pain and receive pregnancy testing (aimed at detecting ectopic pregnancy). Methods We analyzed data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) (2002 to 2006) to test trends and predictors of the new measure, using both restrictive and broad definitions from the International Classification of Diseases, Ninth Revision (ICD-9) and reason-for-visit codes, and determine the proportion of women with ectopic pregnancy who had undergone pregnancy testing. For comparison, we conducted a detailed chart review in 4 US hospitals among patients who visited the ED in 2006. Results Using a broad ICD-9 definition for inclusion in NHAMCS, 2.13 million women aged 14 to 50 years with abdominal pain visited an ED annually between 2002 and 2006. Of those, 33.0% (95% confidence interval [CI] 30.5% to 35.5%) received pregnancy testing. Testing rates were materially stable, regardless of the definition used (broad or restrictive ICD-9 or reason-for-visit code). Among women with an ICD-9 diagnosis of ectopic pregnancy, 55.6% (95% CI 43.7% to 67.6%) had a documented pregnancy test. In the chart review, among 200 women aged 14 to 50 years and with abdominal pain, 89.4% (95% CI 85.0% to 94.0%) were eligible for the measure; of those, 93.9% (95% CI 90.3% to 97.4%) received testing. Conclusion Analysis of national ED survey data demonstrated a large performance gap for a new pregnancy testing quality measure, whereas focused chart review at 4 sites showed a smaller gap. Given these discrepancies, additional study is recommended before the widespread implementation of the pregnancy testing measure as an assessment of ED performance.
Comprehensive volumetric confocal microscopy with adaptive focusing

Comprehensive microscopy of distal esophagus could greatly improve the screening and surveillance of esophageal diseases such as Barrett’s esophagus by providing histomorphologic information over the entire region at risk. Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal microscopy technology that can be configured to image the entire distal esophagus by helically scanning the beam using optics within a balloon-centering probe. It is challenging to image the human esophagus in vivo with balloon-based SECM, however, because patient motion and anatomic tissue surface irregularities decenter the optics, making it difficult to keep the focus at a predetermined location within the tissue as the beam is scanned. In this paper, we present a SECM probe equipped with an adaptive focusing mechanism that can compensate for tissue surface irregularity and dynamic focal variation. A tilted arrangement of the objective lens is employed in the SECM probe to provide feedback signals to an adaptive focusing mechanism. The tilted configuration also allows the probe to obtain reflectance confocal data from multiple depth levels, enabling the acquisition of three-dimensional volumetric data during a single scan of the probe. A tissue phantom with a surface area of 12.6 cm2 was imaged using the new SECM probe, and 8 large-area reflectance confocal microscopy images were acquired over the depth range of 56 μm in 20 minutes. Large-area SECM images of excised swine small intestine tissue were also acquired, enabling the visualization of villous architecture, epithelium, and lamina propria. The adaptive focusing mechanism was demonstrated to enable acquisition of in-focus images even when the probe was not centered and the tissue surface was irregular.
Flexure of the Indian plate and intraplate earthquakes

The flexural bulge in central India resulting from India's collision with Tibet has a wavelength of approximately 670 km. It is manifest topographically and in the free-air gravity anomaly and the geoid. Calculations of the stress distribution within a flexed Indian plate reveal spatial variations throughout the depth of the plate and also a function of distance from the Himalaya. The wavelength (and therefore local gradient) of stress variation is a function of the effective elastic thickness of the plate, estimates of which have been proposed to lie in the range 40–120 km. The imposition of this stress field on the northward moving Indian plate appears fundamental to explaining the current distribution of intraplate earthquakes and their mechanisms. The current study highlights an outer trough south of the flexural bulge in central India where surface stresses are double the contiguous compressional stresses to the north and south. The Bhuj, Latur and Koyna earthquakes and numerous other recent reverse faulting events occurred in this compressional setting. The N/S spatial gradient of stress exceeds 2 bars/km near the flexural bulge. The overall flexural stress distribution provides a physical basis for earthquake hazard mapping and suggests that areas of central India where no historic earthquakes are recorded may yet be the locus of future damaging events.
Decomposition and litter production in a northern bald cypress swamp

. Primary production as measured by annual mean litter fall in the Lower Cache near Perks, Illinois, was the lowest recorded for cypress swamps (2345.5 kg/ha/yr). This swamp is continuously flooded with a low input of phosphorus (< 0.24 mg 1). Rates of leaf litter decomposition were higher in the Lower Cache for Taxodium distichum than in swamps to the south of the region. The winter rates of leaf litter decomposition in the Lower Cache were slower than summer rates for Cephalanthus occidentalis, Echinochloa muricata, Polygonum pensylvanicum, Jussisaea repens, Taxodium distichum, and Eleocharis obtusa, but not for Typha latifolia. Because the 99% turnover rates for these species (0.69–5.10 years) often exceeds one year, undecomposed litter can be expected to accumulate or be exported from the system. Most leaves are shed in the autumn (October through December; 83.6%).
Equilibrium and natural frequencies of cable structures (a nonlinear finite element approach)

Abstract This paper concerns the finite element method as applied to cable structures. A family of nonlinear elements is developed. The class of elements developed retains all geometric nonlinearities and allows for any elastic deformation. The problems of static deflection and natural frequency determination for small oscillations about the nonlinear equilibrium position are investigated for single-span cables.
Identifying the causes of differences in ozone production from the CB05 and CBMIV chemical mechanisms

Abstract. An investigation was conducted to identify the mechanistic differences between two versions of the carbon bond gas-phase chemical mechanism (CB05 and CBMIV) which consistently lead to larger ground-level ozone concentrations being produced in the CB05 version of the National Air Quality Forecasting Capability (NAQFC) modeling system even though the two parallel forecast systems utilize the same meteorology and base emissions and similar initial and boundary conditions. Box models of each of the mechanisms as they are implemented in the NAQFC were created and a set of 12 sensitivity simulations was designed. The sensitivity simulations independently probed the conceptual mechanistic differences between CB05 and CBMIV and were exercised over a 45-scenario simulation suite designed to emulate the wide range of chemical regimes encountered in a continental-scale atmospheric chemistry model. Results of the sensitivity simulations indicate that two sets of reactions that were included in the CB05 mechanism, but which were absent from the CBMIV mechanism, are the primary causes of the greater ozone production in the CB05 version of the NAQFC. One set of reactions recycles the higher organic peroxide species of CB05 (ROOH), resulting in additional photochemically reactive products that act to produce additional ozone in some chemical regimes. The other set of reactions recycles reactive nitrogen from less reactive forms back to NO2, increasing the effective NOx concentration of the system. In particular, the organic nitrate species (NTR), which was a terminal product for reactive nitrogen in the CBMIV mechanism, acts as a reservoir species in CB05 to redistribute NOx from major source areas to potentially NOx-sensitive areas where additional ozone may be produced in areas remote from direct NOx sources.
A realistic appraisal of weather control

Verschiedene Methoden der Wolkenbeeinflussung werden im Lichte ihrer moglichen Anwendung zur Wetterkontrolle untersucht. Die Studie ergibt, dass nur wenige Techniken praktisch brauchbare Resultate versprechen.
Rumen-protected amino acids for dairy cattle: Progress towards determining lysine and methionine requirements

Abstract Progress has been made in determining lysine (Lys) and methionine (Met) requirements of the lactating dairy cow. Dose-response relationships for both amino acids (AA) have been obtained by increasing postruminal supplies of Lys and Met in graded fashion via abomasal infusion while production responses and AA flows to the duodenum are measured and by an indirect dose-response approach. From the established dose-response relationships, it is concluded that for cows fed conventional diets, Lys must contribute 14.7–16.7% and Met 5.3–5.6% of total essential AA in duodenal digesta (7.0–8.0% and 2.5–2.7% of total AA, respectively) for maximum content and yield of milk protein. However, further research must be directed toward the refinement of these requirements, particularly for the early lactation cow. The attention given to Lys and Met thus far also must be given to other potentially limiting AA and rumen undegradable intake protein sources appropriately balanced for them if the maximum benefits of optimizing Lys and Met nutrition are to be realized. Because the production response to graded levels of an AA is one of diminishing returns, the “practical” requirements to which one formulates will be governed by economic considerations. Production studies that are designed to determine the value of optimizing intestinal AA balance must be initiated at or before parturition. Only in this way can the full effects on herd health and lactational performance be realized.
The anxiety spectrum and the reflex physiology of defense: from circumscribed fear to broad distress.

Guided by the diagnostic nosology, anxiety patients are expected to show defensive hyperarousal during affective challenge, irrespective of the principal phenotype. In the current study, patients representing the whole spectrum of anxiety disorders (i.e., specific phobia, social phobia, panic disorder with or without agoraphobia, obsessive-compulsive disorder, generalized anxiety disorder (GAD), posttraumatic stress disorder(PTSD)), and healthy community control participants, completed an imagery-based fear elicitation paradigm paralleling conventional intervention techniques. Participants imagined threatening and neutral narratives as physiological responses were recorded. Clear evidence emerged for exaggerated reactivity to clinically relevant imagery—most pronounced in startle reflex responding. However, defensive propensity varied across principal anxiety disorders. Disorders characterized by focal fear and impairment (e.g., specific phobia) showed robust fear potentiation. Conversely, for disorders of long-enduring, pervasive apprehension and avoidance with broad anxiety and depression comorbidity (e.g., PTSD secondary to cumulative trauma, GAD), startle responses were paradoxically diminished to all aversive contents. Patients whose expressed symptom profiles were intermediate between focal fearfulness and broad anxious-misery in both severity and chronicity exhibited a still heightened but more generalized physiological propensity to respond defensively. Importantly, this defensive physiological gradient—the inverse of self-reported distress—was evident not only between but also within disorders. These results highlight that fear circuitry could be dysregulated in chronic, pervasive anxiety, and preliminary functional neuroimaging findings suggest that deficient amygdala recruitment could underlie attenuated reflex responding. In summary, adaptive defensive engagement during imagery may be compromised by long-term dysphoria and stress—a phenomenon with implications for prognosis and treatment planning. Depression and Anxiety 29:264–281, 2012.
Auger electron contribution to bromodeoxyuridine cellular radiosensitization

Halogenated thymidine analogs become incorporated into the DNA of proliferating cells during S-phase and may be used clinically to radiosensitize tumors that are otherwise poorly responsive to radiation. Although radiosensitization has been studied for years, mechanisms of radiosensitization are poorly understood. One possible mechanism involves the release of short range, high-LET, Auger electrons following photoelectric absorption of an X ray by the K-shell of the incorporated halogen. Such absorption occurs only with X ray energies slightly greater than the K-shell binding energy. We report the results of an experiment designed to measure this effect, in which cultured monolayers of Chinese hamster V79 cells, with 32% replacement of thymidine by bromodeoxyuridine (BUdR), were exposed to monoenergetic X rays just below (13.450 KeV) or above (13.490 KeV) the K-edge (13.475 KeV) of bromine. Enhancement ratios calculated in five different ways were slightly increased (3-12%) above the K-edge compared to below. However, only a calculation using a linear-quadratic fit to the data and a surviving fraction of 0.01 demonstrated a statistically significant increased enhancement ratio (12%) above the K-edge. We conclude that Auger electrons produced following photoelectric absorption of X rays by the K-shell of bromine contribute minimally to observed BUdR cellular radiosensitization.
Corporal punishment by parents and associated child behaviors and experiences: A meta-analytic and theoretical review.

Although the merits of parents using corporal punishment to discipline children have been argued for decades, a thorough understanding of whether and how corporal punishment affects children has not been reached. Toward this end, the author first presents the results of meta-analyses of the association between parental corporal punishment and 11 child behaviors and experiences. Parental corporal punishment was associated with all child constructs, including higher levels of immediate compliance and aggression and lower levels of moral internalization and mental health. The author then presents a process– context model to explain how parental corporal punishment might cause particular child outcomes and considers alternative explanations. The article concludes by identifying 7 major remaining issues for future