cssi/SciSciGPT-SciSciNet huggingface dataset:
More precisely defining and measuring the order-irrelevance principle ☆

Abstract R. Gelman and C. Gallistel (1978 , Young Children's Understanding of Number, Cambridge, MA: Harvard Univ. Press) use two definitions of the order-irrelevance principle interchangeably: (1) count tags do not have to be assigned in a fixed order and (2) the order in which elements of a set are enumerated does not affect the cardinal designation of the set. A study involving 107 kindergarten and first grade children indicates that the two are actually distinct concepts. Apparently, a willingness to arbitrarily assign tags is a developmentally less sophisticated ability than—and hence does not necessarily imply—an ability to predict that differently ordered counts produce the same cardinal designation. Thus it appears that evidence of the second ability is necessary to infer a full understanding of the order-irrelevance principle. The first ability alone implies what might better be termed an “order-indifferent tagging scheme”. Suggestions for measuring and further researching the order-irrelevance principle are discussed.
Humic acids as electron acceptors in wetland decomposition

Decomposition of organic matter in inundated wetland soils requires a number of interdependent microbial processes that ultimately generate CO2 and CH4. Largely as the result of anaerobic decomposition, wetland soils store globally significant amounts of organic carbon and are currently net sources of CH4 to the atmosphere. Given the importance of wetlands in the global carbon cycle, it is important to understand controls on anaerobic decomposition in order to predict feedbacks between wetland soils and global climate change. One perplexing pattern observed in many wetland soils is the high proportion of CO2 resulting from anaerobic decomposition that cannot be explained by any measured pathway of microbial respiration. Recent studies have hypothesized that humic substances, and in particular solid-phase humic substances in wetland soils, can support anaerobic microbial respiration by acting as organic electron acceptors. Humic substances may thus account for much of the currently unexplained CO2 measured during decomposition in wetland soils. Here we demonstrate that humic acids extracted from a variety of wetland soils act as either electron donors or electron acceptors and alter the ratio of CO2:CH4 produced during anaerobic laboratory incubations. Our results suggest that soil-derived humic substances may play an important, and currently unexplored, role in anaerobic decomposition in wetland soils.
ON THE DEVELOPMENT AND STRUCTURE OF THE CELL WALL IN NITELLA

THE INTERNODE CELLS of the aquatic alga Nitella axillaris Braun provide unusually interesting material for the study of cell wall development. In about two weeks these cylindrical cells grow from microscopic size to a mature length greater than 2 cm. The final diameter is about 0.3 mm. Throughout this growth the cylindrical surface of the cell is freely exposed to the aqueous medium; contact with the rest of the plant is made only at the ends of the internode cell (fig. 4). This report will present structural information about these walls and relate this information to other descriptive facts of wall development in Nitella. The growth pattern of the cell surface has been described (Green, 1954). If a longitudinal row of small evenly-spaced marks is placed on a young cell, the marks will be displaced by the growth of the cell. The marks become distant from each other in a way which demonstrates an essentially even distribution of elongation. Since the wall is at all times a right cylinder, increase in girth must also be evenly distributed along the cell axis. The row of marks, while maintaining its regularity, is transformed into a helical configuration as the wall elongates, hence a type of "spiral" growth is found in this cell. The twisted state of any cell may be quantitatively determined from an examination of the two striations which are representative lines of twist. The striations are visible in the living cell as colorless streaks in an otherwise uniform green layer of stationary chloroplasts just interior to the wall. These striations are 1800 apart on the cell surface and each forms a regular "Z-spiral" helix (the striation en the near surface of an upright cell being parallel to the diagonal of an upright letter Z). This helix is also termed "dextral." Each striation is almost parallel to the cell axis in the very young cell; the angle between a striation and the cell axis can become as great as 30? during the middle stages of development; the angle with the cell axis (/3) decreases to about 5? as maturity is reached. This normal development is diagrammed in fig. 4. Cells which cease to grow while in the highly twisted form maintain their twist permanently. Compressing or stretching such cells does not noticeably alter the twist. Further, growing walls in the twisted state show only a barely detectable
ERYTHROPOIETIN (EPO) MAY PROMOTE NEURONAL SURVIVAL FOLLOWING HYPOXIA, BY REPRESSING APOPTOSIS • 1734

We previously demonstrated the presence of erythropoietin receptors (Epo-R) on neurons in the developing human fetus (Peds Res, 40:376-380, 1996) but their function is unknown. A mechanism by which Epo promotes erythropoiesis is by decreasing apoptotic cell death of red cell precursers via the BCL2 and BLX pathways. Serum Epo concentrations increase with hypoxic stimuli, and neuronal Epo mRNA expression increases following hypoxia. We hypothesized that a physiologic role for Epo and Epo-R on human neurons involves protecting neurons from apoptotic cell death following hypoxia, using mechanisms similar to those utilized in the hematopoietic pathway. To test this hypothesis we first determined that Epo-R were present on NT2 cells and HNT cells, (a human neuronal cell line, and its mature neuronal counterpart) by RT-PCR. These cells were then incubated in 1% O2, 5% CO2, 94% N2 for 24, or 48 hours in the presence of rEpo (0 U/mL, 0.1 U/mL, 1.0 U/mL or 10 U/ml) followerd by 24 hours of normoxia. Evidence of apoptosis was determined by measurement of nuclear matrix proteins (NMP) from the conditioned media by ELISA. Nuclear matrix apparatus proteins are released into the media when cell death by occurs by apoptosis, but not by necrosis. Epo decreased the effect of hypoxia in a dose dependent manner in both NT2 cells and HNT cells at 24 and 48 hours. After 24 hours of hypoxia, NMP release by mature neurons incubated in the presence of 10 U/mL rEpo was reduced by 30%, to a level below that measured in normoxic controls. After 48 hours of hypoxia, NMP release by NT2 cells incubated with 1 U/mL rEpo was 43% the amount released by cells in hypoxia alone. We speculate that Epo-R expressed on human fetal neurons might constitute a previously undescribed physiologic mechanism for neuro-protection during fetal hypoximic episodes.
Regulatory science: what it is and why we need it

“Regulatory science” could be interpreted as the “brand” of science pursued by regulatory agencies such as the US Food and Drug Administration (FDA). The discipline enhances the science base of such agencies, and offers an incentive to sponsors to accelerate understanding of the spectrum of action of therapeutics in ways pertinent to the personalization of medicine. The development of expertise in translational medicine and therapeutics (TMAT) in academia and industry enhances the benefit for public health. Clinical Pharmacology & Therapeutics (2011) 89 2, 291–294. doi:10.1038/clpt.2010.276
Progress toward a national union list of newspapers

Nearly two decades ago, discussions took place between the National Endowment for the Humanities (NEH) and the American Council of Learned Societies (ACLS) concerning the establishment by the Endowment of a long-term program to support the preparation of research tools for scholars. The ACLS, in response, surveyed its constituent societies to determine projects worthy of such support. One of those societies, the Organization of American Historians (OAH), had for the two years prior to this survey listed a revision of American Newspapers, 1821-1936; a Union List of Files Available in the United States and Canada, edited by Winifred Gregory, as a high priority. 1 This work was published in 1937 and though sorely out -of-date remained the most comprehensive guide to newspaper holdings in North America. In 1973 the OAH applied for and received a grant from NEH to carry out further study before taking on such a project. As might be expected, the study was expanded; the broader needs for newspaper access were studied as well, and the entire period of newspaper publishing in the United States was included. The expanded survey was designed to include the titles listed in the earlier reference work, History and Bibliography of American Newspapers, 1690-1820, 9 prepared by Clarence Brigham, as well as the Library of Congress publication, Newspapers in Microform, s and the growing number of state bibliographies that had been produced since 1937. It should be clear immediately that the original plan to produce a revision of Gregory that would
Effect of estrogen on mammary gland growth of immature male rats.

SummaryThe normal growth of the mammary glands of male rats of the Sprague-Dawley-Rolfsmeyer strain was compared to that induced by 1 μg/day of estradiol benzoate (EB) from 40 to 80 days by the DNA method. The mean DNA/100 g BW of the normal male rat at 40 days of age was 2.25 mg, at 60 days, 2.90 mg, an increase of 28.8%, and at 80 days, 2.87 mg. The rats injected with EB from 20 to 40 days had a mean DNA/100 g BW of 1.92 mg, 0.33 mg less than the controls. After 40 days of EB (age 60 days), the mean DNA was 2.33 mg still, 0.57 mg less than the control group. After 60 days of EB (age 80 days), the mean DNA was 3.0 mg, the same as the controls, and 28.7% greater than the previous level. This level of DNA is equal to that present in mature ovariectomized female rats.
Immigrant businesses, place-making, and community development: a case from an emerging immigrant gateway

Immigrant businesses have become an increasingly important component in the US economy. However, very few studies have systematically examined the role of immigrant businesses in community development, except for some cases in established immigrant gateways such as New York and Miami. In this study, we explore how immigrant businesses are shaping physical, cultural, social, economic, and political landscapes in their local communities in the emerging immigrant gateway of Charlotte, North Carolina. Focusing on the case of a multiethnic retail corridor, we find that, as active place-makers, immigrant businesses have transformed deteriorating and abandoned street fronts into vibrant and well-frequented urban environments conducive for further development. Through a systematic approach to understanding the place-making process of immigrant businesses, findings from this study call for more in-depth integration of immigrant and ethnic economies in local policies and planning strategies for neighborhood revital...
A Study of Polarization Capacity over a Wide Frequency Band

The polarization capacity of platinum electrodes in sulphuric acid and also of gold electrodes in sulphuric acid has been studied from 200 to 200,000 cycles per second. An alternating current bridge was used to make the measurements in the audible range and a bridge with heterodyne detector for the higher frequencies. If the relation connecting capacity and frequency is put in the form $C=\frac{{C}_{0}}{{f}^{P}}$ where ${C}_{0}$ and $P$ are constants then at the lower frequencies $P$ is nearly equal to.3 while at the higher frequencies it approaches.5. At the same time, the phase angle of the capacity shifts from about 20 to about 40 degrees. Voltage measurements made to determine the limiting value of the initial capacity show that it is of the same order of magnitude for alternating current as for direct charge. When two harmonic alternating currents of differing frequencies are simultaneously impressed on a cell, the polarization capacity measured by means of either one is independent of the presence of the other.
Trans-world identification and stipulation

Soulevant le probleme de l'identification trans-mondaine dans le domaine de la philosophie de la modalite, l'A. examine la these haeccetiste de S. Kripke selon laquelle les mondes possibles sont stipules et non pas decouverts. Distingant la version de l'haeccetisme extreme du reductionnisme et de l'anti-haeccetisme, l'A. montre que la formulation du probleme en termes de survenance modale s'apparente a la recherche essentialiste d'un principe metaphysique d'individuation
IN THE SHADOW OF THE CONCENTRATION CAMP: DAVID ROUSSET AND THE LIMITS OF APOLITICISM IN POSTWAR FRENCH THOUGHT

In 1949, French intellectual David Rousset publicly called on Nazi camp survivors to bear witness to the existence of a “concentration camp universe” in the Soviet Union. Rousset, a former Buchenwald internee and an influential author, demanded that his fellow survivors identify in unqualified terms with the suffering of Soviet prisoners. Even as he colluded with Cold War governmental agencies, Rousset claimed that the imperative to oppose concentration camps existed “beyond” political or ideological commitments. This essay analyzes the arguments about suffering, politics, and memory made by Rousset and his contemporary critics, notably Jean-Paul Sartre. It responds to Rousset's admirers who have overlooked distinctive aspects of his project: his rhetoric of apoliticism, his demand for complete identification with victims, his exclusive interest in limit-case abjection as opposed to injustice in general, his interpretation of the Nazi camps that centered on forced labor rather than on genocide, and his avoidance of the language of human rights.
"Ambivalent Conversions" in Nayarit: Shifting Views of Idolatry

The Jesuit and Franciscan mission periods in New Spain's western province of Nayarit claimed numerous converts to Christianity, principally Cora Indians. Despite the efforts of missionaries and presidial soldiers, the indigenous residents of this rugged mountainous region persisted in clandestine non-Christian religious rituals. The extirpation of this "idolatry" was uneven, and the Coras emerged from the nineteenth century with a uniquely forged ceremonial tradition that fuses Catholic and indigenous practice and belief.
What Makes for a Good Day? Competence and Autonomy in the Day and in the Person

This diary study examined the proposal that satisfaction of two psychological needs, competence and autonomy, leads to daily well-being. Between-subjects analyses indicated that participants higher in trait competence and trait autonomy tended to have "better" days on average. Independently, within-subject analyses showed that good days were those in which participants felt more competent and autonomous in their daily activities, relative to their own baselines. Other predictors of daily well-being included gender, whether the day fell on a weekend, and the amount of negative affect and physical symptomatology felt the day before. Although past diary studies have tended to focus on threats to daily well-being, the authors suggest that psychological need concepts offer promise for understanding its positive sources.
Course on the simulation of optical components and systems

At Georgia Tech the course on Optical Fabrication was dropped from the catalog because the equipment was obsolete in comparison with current technology. In addition, maintenance was becoming difficult and costly. However, there was still a need to provide students with a feel for the design decisions that must be made when specifying a component. We have designed a course to provide students experience in the use of design and simulation programs for optical systems and components. Three types of simulations were explored by the students: lens design, thin film design, and physical optics simulations. This combined lecture and laboratory introduced the student to commercial design packages and provide the background on the theory used in the simulations. A number of problems and projects have been devised to provide practice in the use of these programs. This paper is a report on the first offering and evaluations of the course by the students.
Effect of the Corn Breaking Method on Oil Distribution between Stillage Phases of Dry-Grind Corn Ethanol Production

The majority of fuel ethanol in the United States is produced by using the dry-grind corn ethanol process. The corn oil that is contained in the coproduct, distillers' dried grains with solubles (DDGS), can be recovered for use as a biodiesel feedstock. Oil removal will also improve the feed quality of DDGS. The most economical way to remove oil is considered to be at the centrifugation step for separating thin stillage (liquid) from coarse solids after distilling the ethanol. The more oil there is in the liquid, the more it can be recovered by centrifugation. Therefore, we studied the effects of corn preparation and grinding methods on oil distribution between liquid and solid phases. Grinding the corn to three different particle sizes, flaking, flaking and grinding, and flaking and extruding were used to break up the corn kernel before fermentation, and their effects on oil distribution between the liquid and solid phases were examined by simulating an industrial decanter centrifuge. Total oil contents were measured in the liquid and solids after centrifugation. Dry matter yield and oil partitioning in the thin stillage were highly positively correlated. Flaking slightly reduced bound fat. The flaked and then extruded corn meal released the highest amount of free oil, about 25% compared to 7% for the average of the other treatments. The freed oil from flaking, however, became nonextractable after the flaked corn was ground. Fine grinding alone had little effect on oil partitioning.
New patrons: new challenges

The information age has brought libraries an entire new group of potential patrons, the so‐called “print disabled”. For many librarians, retooling to keep up with the invasion of digitized information seems frightening and overwhelming. The thought of having to take that a further step and become familiar with the specialized hardware and software that people with disabilities use to adapt the computer seems like asking too much. The goal of this column is to persuade librarians that taking on this new task will be a challenge and opportunity rather than another burden. A number of tools and products are discussed. This time the focus is on IBM’s Home Page Reader.
Median frequency — a new parameter for predicting defibrillation success rate

Study hypothesis: Current American Heart Association guidelines recommend immediate defibrillation of ventricular fibrillation. When this is unsuccessful, there are no guidelines to help determine the optimum time at which to defibrillate after the administration of an a-adrenergic agonist. Previous studies have shown that the median frequency of the ventricular fibrillation ECG signal correlates with myocardial perfusion during CPR. We hypothesized that median frequency could predict the success of defibrillation and thus accurately determine the most appropriate time at which to defibrillate during ventricular fibrillation. Study population: Twenty-two mixed-breed swine weighing more than 15 kg were studied. Methods: Ventricular fibrillation was induced electrically, and the ventricular fibrillation ECG signal was analyzed using fast Fourier analysis. After ten minutes of ventricular fibrillation, mechanical CPR was begun. After three minutes of CPR, the animals received one of three α-adrenergic agonists and CPR was continued. Defibrillation was attempted three and one-half minutes after drug administration. The average median frequency 20 seconds before defibrillation was calculated. Sensitivity and specificity of median frequency with respect to defibrillation success were determined. Results: A median frequency of 9.14 Hz had a sensitivity of 100% and a specificity of 92.31% in predicting the results of defibrillation in this model. Conclusion: The median frequency may serve as a valuable parameter to guide defibrillation therapy during ventricular fibrillation.
The lower atmosphere of the polar regions

Alfred Wegener initiated the study of the free polar atmosphere with more than 100 kite and tether balloon soundings to above 3000 m at Danmarkshavn, North Greenland, during 1906–09. From this beginning polar aerology advanced through a series of similar point studies to the first full upper air network during the IGY (1957/8). While its replacement by satellite remote sensing is gradually taking shape, the accumulated polar information has been thoroughly analyzed; a series of comprehensive accounts is referenced. The aspects singled out for this review are themes that would have been of special interest to Wegener — the surface energy balance and the polar inversion, the katabatic winds and snow drift, and the aerosols of the polar atmosphere.
Regularization of Two-Phase Flow Models

This paper illustrates the dominant role that numerical damping plays in the regularization of the two-phase flow models used in the RELAP5 and CATHARE codes. Dispersion analysis for a practical range of wave-number is used to examine the stability characteristics of both differential and numerical implementations of the two models. In this study it was found that numerical damping overshadows the effect of differential terms when they were added specifically to achieve a well-posed differential model such as is done for some flow regimes in the CATHARE code. Furthermore the added terms can result in non-physical dynamic behavior of the model.
Subspace analysis for characterizing dynamic functional brain networks

Human brain is known to be one of the most complex biological systems and understanding the functional connectivity patterns to distinguish between normal and disrupted brain behavior still remains a challenge. Previous studies focus on analyzing functional connectivity averaged over a certain time and frequency window which is generally not sufficient to address the time-varying evolution of the connectivity patterns. In this paper, we propose a framework to describe the dynamic properties of functional connectivity in the brain. The proposed approach is based on constructing time-varying connectivity graphs from multichannel electroencephalogram (EEG) data, using subspace analysis to detect network-wide changes, identifying key event intervals and then extracting representative networks that describe the connectivity in each event interval. This framework is evaluated for EEG data, containing error-related negativity (ERN) component related to cognitive control. For each time interval, the statistically significant connectivity patterns are presented to illustrate the dynamic nature of functional connectivity.
TRANSPLANTATION: PAST, PRESENT AND FUTURE.

!1. INTRODUCTION It is a great privilege to give this, the third Herman Beerman Lecture, on “Transplantation: Past, Present and Future” in honor of a man to whom biologists and clinicians alike owe a great debt for his invaluable services to the cause of both experimental and investigative dermatology.
Ambulatory pediatric otolaryngologic procedures in the United States: characteristics and perioperative safety.

Objectives/Hypothesis: Determine the prevalence and safety of pediatric ambulatory otolaryngologic procedures in the United States. Study Design: Historical cohort study. Methods: All cases of pediatric otolaryngologic surgery were extracted from the National Survey of Ambulatory Surgery 2006 release. The population was characterized according to age, sex, and individual procedures performed. Rates of immediate perioperative complications were determined for arrest, malignant hyperthermia, hemorrhage, blood transfusion, and postoperative nausea/vomiting. Discharge status and unexpected medical return visits were tabulated. Complication rates for patients younger than 3 years were compared to the remaining cohort. Results: An estimated 1,410,546 ± 246,009 (± standard error) children underwent one or more pediatric otolaryngologic procedures in 2006 (mean age, 6.23 ± 0.19 years; 50.9% ± 2.2% male). The most common primary procedures performed were myringotomy and tube (551,222 cases), tonsillectomy with adenoidectomy (480,343 cases), adenoidectomy (81,048 cases), tonsillectomy (56,606 cases), myringotomy alone (27,691 cases), tympanostomy tube removal (21,446 cases), and close reduction of nasal fracture (15,230 cases). There were no reported cases of cardiac arrest, malignant hyperthermia, or blood transfusion. Postoperative nausea, vomiting, and perioperative bleeding occurred in 1.4%, 0.9%, and 0.2% of cases, respectively. Children younger than 4 years undergoing tonsillectomy were more likely to return to the surgery center (2.5%, P < .001) or have an unplanned admission (9.28%, P = .011) than older children. Conclusions: Pediatric otolaryngologic surgery is not only common but very safe in the ambulatory setting, with relatively minor complications occurring at rates of approximating 1%. Life-threatening complications are exceedingly rare. Ambulatory tonsillectomy in children younger than 4 years requires careful selection. Laryngoscope, 2010
The tech hotlist: grid computing and P2P

The article is a review of the book: From P2P to Web Services and Grids: Peers in a Client Server World by I.J. Taylor and published by Springer, 2004. The book provides a comprehensive, updated review of the new and improved distributed computing technology formed by the union of computing and communications. The author wrote the book primarily for university students. It's written like a textbook, and very well, too. You need a computing foundation and some familiarity with grid computing to grasp all the concepts. The book does, however, give a good overview of the technology before delving too deeply into the details. Each chapter builds the technical knowhow needed for the next one.
Reducing the toxicity of castor seed meal through processing treatments

Abstract The castor plant produces a seed that is high in oil content and composed of approximately 90% ricinoleate. Due to the numerous uses of castor oil and ricinoleate, the oil is in high demand. However, the presence of a protein toxin in the seed meal is a key concern about processing the castor seed to obtain the oil and to utilize the meal. We have addressed this issue by identifying approaches for reducing or eliminating toxin activity during seed processing through proteolytic treatment or microwave pretreatment. Treatment with the protease papain apparently eliminates coomassie stainable proteins corresponding to ricin bands. Microwave pretreatment to heat seeds internally reduced ricin bands slightly as reflected on SDS–PAGE, but the ricin activity was 86% inactivated.
Retinal and choroidal blood flows in hypoxic and hypercarbic newborn lambs

Summary: We studied the effect of changes in the arterial tensions of oxygen and carbon dioxide on blood flow to the retinal (RBF) and choroidal (ChBF) capillary beds in 20 lambs. One to three days after placement of catheters in the left ventricle, abdominal aorta, and brachiocephalic artery, different gas mixtures were delivered to a bag enclosing the lamb's head. One group of lambs was studied at normal and low oxygen tensions while normocarbic, and another group was studied at normal and high carbon dioxide tensions while normoxic. RBF and ChBF were measured using the radioactive microsphere technique. RBF increased as PaO2 and, thus, arterial oxygen content ([O2]a) fell; in contrast, ChBF was not related to [O2]a. Oxygen delivery to the capillary bed of the retinal artery (i.e., RBF × [O2]a) was independent of arterial oxygen content because the change in [O2]a was balanced by a reciprocal change in RBF. Oxygen delivery to the choroidal capillary bed, however, rose with [O2]a because there was no reciprocal decrease in ChBF. Both RBF and ChBF increase as arterial carbon dioxide tension rose. Although an increase in arterial carbon dioxide tension produced an increase in RBF with no change in [O2]a, oxygen delivery to the retinal capillaries rose. Similarly, oxygen delivery to the capillaries of the choroid rose with carbon dioxide tension. Oxygenation of retinal tissue, which depends on oxygen diffusion from both the retinal and choroidal capillary beds, may change with variations in arterial oxygen content (increase in oxygen delivered to the choroidal capillary bed) or arterial carbon dioxide tension (increase in oxygen delivered to both the retinal and choroidal capillary beds).
Sunlight, melanogenesis and radicals in the skin.

Melanocytes are cells of neural crest origin residing at the dermal-epidermal juncture. They produce specialized organelles called melanosomes within which the biochemical processes of melanization occurs. UV radiation is capable of inducing melanogenesis and, during the biosynthesis of melanins, several of the putative precursors “leak out” of the melanosome and can be detected in the skin, serum and urine of individuals undergoing active melanogenesis. Most notable are the cysteinyldopas (formed by nucleophilic addition of cysteine to dopaquinone) and several dihydroxyindoles (formed by intramolecular cyclization of dopaquinone). These catechols often are methylated in the melanocyte to afford a mixture of the monomethoxy derivatives and, in some cases, the dimethoxy species.
Testing for shared biogeographic history in the lower Central American freshwater fish assemblage using comparative phylogeography: concerted, independent, or multiple evolutionary responses?

A central goal of comparative phylogeography is determining whether codistributed species experienced (1) concerted evolutionary responses to past geological and climatic events, indicated by congruent spatial and temporal patterns (“concerted-response hypothesis”); (2) independent responses, indicated by spatial incongruence (“independent-response hypothesis”); or (3) multiple responses (“multiple-response hypothesis”), indicated by spatial congruence but temporal incongruence (“pseudocongruence”) or spatial and temporal incongruence (“pseudoincongruence”). We tested these competing hypotheses using DNA sequence data from three livebearing fish species codistributed in the Nicaraguan depression of Central America (Alfaro cultratus, Poecilia gillii, and Xenophallus umbratilis) that we predicted might display congruent responses due to co-occurrence in identical freshwater drainages. Spatial analyses recovered different subdivisions of genetic structure for each species, despite shared finer-scale breaks in northwestern Costa Rica (also supported by phylogenetic results). Isolation-with-migration models estimated incongruent timelines of among-region divergences, with A. cultratus and Xenophallus populations diverging over Miocene–mid-Pleistocene while P. gillii populations diverged over mid-late Pleistocene. Approximate Bayesian computation also lent substantial support to multiple discrete divergences over a model of simultaneous divergence across shared spatial breaks (e.g., Bayes factor [B10] = 4.303 for Ψ [no. of divergences] > 1 vs. Ψ = 1). Thus, the data support phylogeographic pseudoincongruence consistent with the multiple-response hypothesis. Model comparisons also indicated incongruence in historical demography, for example, support for intraspecific late Pleistocene population growth was unique to P. gillii, despite evidence for finer-scale population expansions in the other taxa. Empirical tests for phylogeographic congruence indicate that multiple evolutionary responses to historical events have shaped the population structure of freshwater species codistributed within the complex landscapes in/around the Nicaraguan depression. Recent community assembly through different routes (i.e., different past distributions or colonization routes), and intrinsic ecological differences among species, has likely contributed to the unique phylogeographical patterns displayed by these Neotropical fishes.
Critical points and manifolds of the Lamb vector field in swirling jets

The Lamb vector field in a swirling jet flow at a Reynolds number in the transitional regime is computed for kinematic analysis. The vector lines for the Lamb vector and streamlines and vortex lines are analyzed in detail. The main result is that the set of critical points of the Lamb vector field contains stable and unstable manifolds characterizing high shear regions. Lamb surfaces do not exist in these regions.
Atomic force microscope tip spontaneous retraction from dielectric surfaces under applied electrostatic potential.

Abstract A time-resolved method for tip’ retraction at μs-scale away from dielectric surfaces has been developed. Analysis of the forces in the system comprising AFM tip, water meniscus, and polymer film suggests that an electrostatic repulsion of the tip from the surface in the double-layered (water and polymer) system, and water condensation in the tip–surface junction are the dominant factors enabling the mechanical work for tip retraction. Nanostructures of 5–80 nm height are formed in polymeric surfaces as a result. This interesting physical phenomenon could be used for nanostructures patterning in polymeric materials at enhanced aspect ratio.
Numerical study of inhomogeneity effects on Hall measurements of graphene films

Abstract This paper presents a two-dimensional model calculation of inhomogeneous graphene films which incorporates a random distribution of dopants (leading to electron and hole puddles) for analysis of Hall measurements. The model predicts significant effects of inhomogeneity on the Hall coefficient, which can lead to an underestimate of carrier mobility. We investigate the effect of parameters including size of puddles, local charge density deviation, and device sizes. The inhomogeneity of epitaxial graphene generated by steps and terraces of SiC substrates is also discussed. The simulation results quantify possible statistical errors in Hall mobility measurements, Dirac point estimation and non-uniformity of scaled devices over wafers.
Linking Learners: Structuring a Mentoring via Telecommunications Course.

To provide college writers with a rich experience in detecting, diagnosing, and analyzing writers' problems, we designed a mentoring via telecommunications course. Via telecommunications technology, secondary-school students sent university mentors copies of writing assignments and mentors provided feedback on how the writing and the students' writing processes could be improved. In this article, we provide a model for designing similar courses by discussing our course design and goals, the technology and logistics of the course, mentor training, and mentor strategies. From our experiences, we suggest that future mentoring courses should consider the power struggles that occur between secondary-school and university environments.
Home cage activity and behavioral performance in inbred and hybrid mice.

Locomotor activity is a key component in many behavioral tests, suggesting that genetic differences in activity levels may be a critical consideration when comparing mouse strains. In order to assess the relationship between activity and performance, we recorded home cage activity, and locomotion and defecation, a non-activity-linked behavior, in tests of anxiety in inbred (C57BL/6J (B6), n = 25; BALB/cJ (C), n = 24; DBA/2J (D2), n = 28) and hybrid (CB6F1/6J (CB6: B6 x C) n = 19) mice. Under our test conditions, the strains showed significant differences in home cage activity levels: C > B6 > D2. The CB6 mice were similar to the B6 mice in horizontal activity and were intermediate between the parental strains in vertical movement. Based on measures of locomotion and defecation in the open field, emergence and novel object tests, and the elevated zero maze, the C mice appeared to be the most anxious and the B6 were the least anxious. The D2 mice were intermediate on some measures but more similar to B6 mice on others, making ranking them more difficult. In addition, the CB6 mice displayed characteristics of both parental strains. They had greater similarity to B6 mice in measures of horizontal movement in the home cage and locomotion in the open field and emergence tests, but exhibited defecation responses similar to those of C mice in the novel object test and elevated zero maze. The results suggest that strain differences in spontaneous locomotion should be considered when interpreting strain differences in behavioral tests, and that home cage activity may be a useful interpretive aid.
A Method to Infer In Situ Reaction Rates from Push‐Pull Experiments

A method to evaluate first-order and zero-order in situ reaction rates from a push-pull test is presented. A single-well push-pull test starts with the rapid injection of a well-mixed slug containing a known quantity of a conservative tracer and a reactive solute into the saturated zone. The slug is then periodically extracted and sampled from the same well. For zero- or first-order reactions, in the absence of sorption and assuming negligible background concentrations, these measurements can be used to evaluate reaction rate coefficients directly. The method does not involve computer-based solute transport models and requires no knowledge of regional ground water flow or hydraulic parameters. The method performs well when the dominate processes are advection, dispersion, and zero- or first-order irreversible reactions. Regional flow velocities must be sufficiently low such that the slug stays within the area of the well during the sampling phase. In the case of zero-order reactions, results using the method proposed here are compared with those obtained through the traditional method of calibrating a computer-based transport model. The two methods give similar estimates of the reaction rate coefficient. The method is general enough to work with a broad range of push-pull experiment designs and sampling techniques.
Northwest outlet channels of Lake Agassiz, isostatic tilting and a migrating continental drainage divide, Saskatchewan, Canada

Lake cores obtained from the northwest outlet of glacial Lake Agassiz in northwest Saskatchewan, Canada, provide a minimum date for the cessation of the flood from the northwest outlet, and a chronology for abandonment of mid-Holocene channels that presently straddle the Mackenzie and Churchill drainage divide. The stratigraphy of a vibracore taken from Long Lake consists of a lower pebble gravel fining to massive sand, silty-clay and then fibrous peat. Wood fragments from the base of the clay yielded an accelerator mass spectrometry (AMS) date of 9120 BP. Because the lake is scour in origin and is in the head of the spillway, the date is considered to be a minimum estimate for cessation of the flood from the northwest outlet at the beginning of the Emerson Phase. A vibracore taken at Haas Lake in an abandoned channel surrounded by muskeg with no influent streams, consists of 0.8 m of stratified, pebble gravel containing abundant shell and wood fragments, overlain by 1.62 m of gyttja with a sharp, conformable lower contact. AMS dates range from 5590 BP from the topmost gravel to 3080 BP within the gyttja. The gravel is interpreted as fluvial, recording a river draining Wasekamio Lake north into the Clearwater River across the present-day drainage divide. Today, a drop of 2 m occurs from Wasekamio Lake southeast to Lac Ile-a-la-Crosse, along 150 km of lake basins parallel to the Cree Lake Moraine. The dates from Haas Lake suggest that before 5200 BP, the drainage divide was about 100 km further southeast, implying that during the Emerson Phase, lake level was controlled by a sill near Flatstone Lake at about 430 m instead of between Wasekamio Lake and the Clearwater River, as was previously proposed. Holocene differential isostatic uplift caused the flow reversal in the upper Churchill basin. Anastomosed channels at the mouth of rivers flowing north into lakes indicate that uplift is still active in the area today.
Heat-Flux Measurements with Temperature-Sensitive Paint in a Mach-6 Quiet Tunnel

A procedure based on an analytical inverse method is developed to calculate heat-flux distributions on a model using a time sequence of temperature-sensitive-paint images acquired in the Purdue qui...
The human Penumbra gene is mapped to a region on chromosome 7 frequently deleted in myeloid malignancies

We previously cloned the murine Penumbra gene based on its differential expression in proerythroblasts/erythroblasts. Subsequently, we identified human Penumbra cDNA from a human bone marrow cDNA library and the human Penumbra gene from a BAC library. Penumbra is a new member of the tetraspanin protein family and exhibits growth-suppressive activity in vitro. In this study, we designed a human Penumbra probe contig and used fluorescent in situ hybridization (FISH) to analyze seven cases of myeloid malignancies with 7q deletions. Five patients with cytogenetic deletions involving 7q31.2∼q32 also showed deletions of Penumbra by FISH; these were not present in two patients with cytogenetic deletions not involving 7q31.2∼q32. Our findings provide the first FISH evidence supporting the mapping of human Penumbra to 7q31.2∼q32 and demonstrate the potential of the Penumbra probe in the detection of 7q31∼q32-related deletions in myeloid malignancies.
Effects of lipid and urea extraction on δ 15 N values of deep-sea sharks and hagfish: Can mathematical correction factors be generated?

Abstract Stable isotope analysis is broadly employed to investigate diverse ecological questions. In order to make appropriate comparisons among multiple taxa, however, it is necessary to standardize values to account for interspecific differences in factors that affect isotopic ratios. For example, varying concentrations of soluble nitrogen compounds, such as urea or trimethylamine oxide, can affect the analysis and interpretation of δ15N values of sharks or hagfish. The goal of this study was to assess the effects of a standard chloroform/methanol extraction on the stable isotope values of muscle tissue obtained from 10 species of sharks and three species of hagfish collected from poorly-known deep-water (>200 m) communities. We detected significant differences in δ15N, %N, and C:N values as a result of extractions in 8 of 10 shark and all three hagfish species. We observed increased δ15N values, but shifts in %N and C:N values were not unidirectional. Mathematical normalizations for δ15N values were successfully created for four shark and two hagfish species. However, they were not successful for two shark species. Therefore, performing extractions of all samples is recommended.
The Performance of Economics Graduates over the Entire Curriculum: The Determinants of Success

Most studies of the determinants of understanding in economics focus on performance in a single course or standardized exam. Taking advantage of a large data set available at the U.S. Naval Academy (USNA), the authors examined the performance of economics majors over an entire curriculum. They found that gender was not a significant predictor of grade point average in economics courses, but grades of male minority students were lower than their counterparts'. The USNA dataset also provides information on Scholastic Aptitude Test scores and personality variables, allowing exploration of their influence on performance. Students characterized as "judging types" (described as decisive, organized, and self-regimented) generally performed better than did students characterized as "perceiving types" (described as curious, adaptable, and spontaneous).
The solubility parameter concept applied to disperse dyeing of polymers

The solubility parameter concept offers a logical link between the theory of solutions and of nonionic (disperse) dyeing. An attempt has been made to apply the concept to correlate the solubility of several disperse dyes in secondary cellulose acetate, cellulose triacetate, and polypropylene with the calculated solubility parameters of both the polymers and the dyes. When the dyes are applied on hydrophilic polymers from an aqueous dispersion, the correlation between the solubility parameter concept and the dye solubility is not close. One of the reasons for this may be the fact that dyeing of the fibers is, in fact, not a solution in the dry fibers, but consists essentially either in displacement of water molecules from the water swollen fibers and/or, perhaps, in additional swelling by the dye. Consideration of this fact and also correcting for the contribution of hydrogen bonding and dipole interactions to the cohesive energy density brings the disperse dye solubility data into a better agreement with the concept. The concept should be applicable without complications to the dyeing of nonpreswollen fibers, such as polypropylene from aqueous dispersion, or any fiber by the Thermosol process and particularly to dyeing from the vapor phase. The few data available appear to support this view.
Characterization of a prototype tabletop x-ray CT breast imaging system

Planar X-ray mammography is the standard medical imaging modality for the early detection of breast cancer. Based on advancements in digital flat-panel detector technology, dedicated x-ray computed tomography (CT) mammography is a modality under investigation that offers the potential for improved breast tumor imaging. We have implemented a prototype half cone-beam CT breast imaging system that utilizes an indirect flat-panel detector. This prototype can be used to explore and evaluate the effect of varying acquisition and reconstruction parameters on image quality. This report describes our system and characterizes the performance of the system through the analysis of Modulation Transfer Function (MTF) and Noise Power Spectrum (NPS). All CT reconstructions were made using Feldkamp's filtered backprojection algorithm. The 3D MTF was determined by the analysis of the plane spread function (PlSF) derived from the surface spread function (SSF) of reconstructed 6.3mm spheres. 3D NPS characterization was performed through the analysis of a 3D volume extracted from zero-mean CT noise of air reconstructions. The effect of varying locations on MTF and the effect of different Butterworth filter cutoff frequencies on NPS are reported. Finally, we present CT images of mastectomy excised breast tissue. Breast specimen images were acquired on our CTMS using an x-ray technique similar to the one used during performance characterization. Specimen images demonstrate the inherent CT capability to reduce the masking effect of anatomical noise. Both the quantitative system characterization and the breast specimen images continue to reinforce the hope that dedicated flat-panel detector, x-ray cone-beam CT will eventually provide enhanced breast cancer detection capability.
An electrode for the determination of glutamine.

Abstract An enzyme electrode specific for glutamine is described. The electrode is prepared by entrapping glutaminase on a nylon net between a layer of cellophane and a Beckman 39137 or Thomas 4923-Q10 cation electrode. The electrode responds to glutamine over the concentration range l0-1–l0-4M with a response time of only 1–2 min. The electrode can be used continuously for about 12 h.
Some numerical methods for limit analysis in continuum mechanics

Abstract A class of nonlinear optimization problems arises in various fields of continuum physics with a common mathematical structure. The problems are governed by a linear partial differential equation subjected to a quadratic inequality constraint. A linear objective function is minimized or maximized over the set of feasible solutions. The problem is approximated in a finite dimensional space in the form of a special nonlinear programming problem. Several techniques for solving the structured nonlinear programming problem are presented and compared with computational results for a sample problem in plasticity.