cssi/SciSciGPT-SciSciNet huggingface dataset:
Showing that Neighborhoods Matter

A long-standing contradiction has posed a critical puzzle to urban sociologists: On the one hand, a wealth of ethnographic studies make the point that the kinds of neighborhoods people inhabit profoundly shape their fortunes; on the other hand, statistical analyses of “neighborhood effects” have often failed to confirm that claim. From the earliest studies of the Chicago School, through classic works such as Whyte’s (1943) Street Corner Society and Suttles’ (1968) description of defended turfs, up to, for example, Harding’s (2010) recent interviews of young boys in Boston, the message, repeatedly, is: neighborhoods have consequences. Yet, ruling out individual-level explanations for variations among places has proven difficult; econometric studies find that experiential and behavioral differences across neighborhoods largely derive from the different kinds of people who “select in” to them. Some scholars have therefore rejected the idea that neighborhoods matter (e.g., Mayer and Jencks 1989) and even the idea’s defenders struggle to find the evidence (e.g., Sharkey 2012). The question of whether contexts such as neighborhoods matter matters to sociologists far beyond the students of the city. Rob Sampson, in his magisterial book, Great American City: Chicago and the Enduring Neighborhood Effect, is fully aware of this controversy’s broadest implications for sociology (see, e.g., Ch. 15; pp. 435–6) and his book is a major contribution to that debate.1 I will discuss how after reviewing the state of play in neighborhood effects. (This contribution to the symposium is thus more focused on basic theory and research than are those of my fellow contributors.) Sociologists assume that contexts—workplaces, schools, organizations, nations, families, and personal networks, as well as neighborhoods—substantially shape individual experience and action. The general public also believes this. Parents, for example, try hard to access the “best” contexts they can find for their children, particularly the “best” neighborhoods, schools, and peer groups. Sociologists have increasingly focused their attention—in part, thanks to Sampson’s Chicago project itself—on whether and how neighborhoods really matter. The number of studies on neighborhood effects grew exponentially since 1990.2 But urban sociologists’ and the public’s assumption that neighborhoods matter may be wrong or may be right only in small ways. Variations across places in individuals’ experiences and actions may be satisfactorily explainable by the personal tastes, resources, and habits that the individuals bring with them. The first direct assault in sociology on the contextual assumption was, I believe, Robert Hauser’s 1970 article on whether the gender composition of schools affects students’ aspirations. He concluded that the “contextual interpretation [in general] is . . . speculative,
Speaker identification improvement using the usable speech concept

Most signal processing involves processing a signal without concern for the quality or information content of that signal. In speech processing, speech is processed on a frame-by-frame basis, usually only with concern that the frame is either speech or silence. However, knowing how reliable the information is in a frame of speech can be very important and useful. This is where usable speech detection and extraction can play a very important role. The usable speech frames can be defined as frames of speech that contain higher information content compared to unusable frames with reference to a particular application. We have been investigating a speaker identification system to define usable speech frames and then to determine a method for identifying those frames as usable using a different approach. We present a simple and intuitive definition and two methods to identify the defined usable speech frames, which have resulted 78% and 68% success rates.
Low-pressure phase equilibria of anhydrous anorthite-bearing mafic magmas

[1] One of the most persistent questions regarding the phase equilibria of mid-ocean ridge basalts (MORB) pertains to the petrogenesis of the anorthitic plagioclase phenocrysts (>An90) that are characteristic of the more primitive members of such suites. Anorthitic phenocrysts are present in many if not most MORB suites in spite of the fact that no naturally occurring MORB glasses have ever been discovered to be in equilibrium with plagioclase more calcic than An85. We have addressed this paradox by attempting to saturate natural basalts with anorthite in a series of 1 atm experiments using three different natural basaltic starting compositions: an N-MORB, an E-MORB, and a continental high-alumina basalt. To ensure duplication of the olivine and anorthite saturation observed in natural anorthite-bearing basalt, the experiments were run in An93-6 capsules with Fo92 olivine added to the starting glass. The compositions of experimental liquids are generally colinear with the trends observed in the lava suites used as the source material for the starting glasses. Significantly, aluminous spinel (Al2O3 contents of 61–68 wt%) was produced at 1290°C in all compositions and chromites (Al2O3 contents of 33–42 wt%) at lower temperatures in N-MORB-derived liquids despite no spinel having been added to the starting mixture. In addition, the experiments produced basaltic liquid in equilibrium with both >Fo89 olivine and >An85 feldspar at temperatures of 1230° and 1210°. These liquids have compositions with Mg# (at% Mg/Mg + FeT*100) that range from 63 to >85. The TiO2-MgO correlation indicates large (∼16–23%) amounts of crystallization for each percent decrease in MgO. These results suggest the possibility that dry, anorthite-bearing basaltic magmas are the product of the interaction between primary melt and Al-spinel-bearing upper mantle. In addition, the results indicate that MORB magmas can undergo a large amount (>50%) of crystallization prior to reaching 8% MgO. Further, although anorthite-bearing magmas have characteristics consistent with their being a significant volumetric component of MORB “parent” magmas, the reaction mechanism suggested for their petrogenesis indicates that they are not necessarily primary magmas.
Alternative Processing as a Mechanism for Regulating Gene Expression

Alternative splicing (AS) is widely accepted to play an important role in the regulation of gene expression in higher organisms and to be responsible for the protein diversity necessary to maintain the complexity of life. The unexpected observation that the number of human genes was not in the hundreds of thousands, but in the range of ca. 25,000, created an apparent discrepancy between gene numbers and organismal complexity. It was difficult to explain how such a simple worm like Caenorhabditis elegans could have almost 20,000 genes compared to the relatively low number in highly complex humans. Although there are other mechanisms that generate protein diversity, AS is the most important (Grabowski and Black, 2001) because it can modulate transcript expression levels by marking transcripts for degradation via nonsensemediated decay (NMD), and modify the structure of gene products by inserting or deleting protein domains (Stamm et al., 2005). Even though, in most cases, a direct link between AS and its function in regulating a specific pathway or process is not known, it is clear that AS is essential for guaranteeing the complexity of an organism and for insuring proper organ functioning, as well. A global analysis of human genes indicates that the majority of AS is involved in transmission, reception and response to cellular signals, with prevalence seen in immune and nervous systems which are involved in processing a large amount of information (Moderek et al., 2001).
Crop yield and tree-leaf production in three planting patterns of temperate-zone alley cropping in Oregon, USA

The objective of this study was to determine crop and tree productivity in several alley cropping planting patterns. The four- year study was conducted in western Oregon, United States and involved irrigated sweet corn (Zea mays) intercropped between hedgerows of red alder (Alnus rubra) and black locust (Robina pseudoacacia). Three alley cropping planting patterns with variable plant populations and tree-crop proximity were tested with each tree species in a randomized block design. Space available to trees and crops determined yield of both plant components. High crop yield coincided with low pruning yield, and vice versa. Compared to monocropping, yield reductions in traditional alley cropping planting patterns with widely spaced, double tree rows ranged from 5% to 15%. A. rubra and R. pseudoacacia coppiced readily and produced 0.9 to 4.7 tons of dry matter pruning biomass per growing season, depending on planting pattern and year. A. rubra yield continually increased during the trial, while the ability of R. pseudoacacia to produce green manure after frequent coppicing appeared to weaken. After four years, soil organic matter was 4 to 7% higher in the topsoil of an alley cropping system compared to a monocropping system. However, continuous growing of sweet corn resulted in decreased soil organic matter levels in both cropping systems compared to original levels. Crop yield reductions and the need for additional management inputs constrain the implementation of alley cropping in temperate climates. Only if benefits other than minor soil fertility improvements are realized is alley cropping a feasible alternative in temperate climate regions.
Moisture availability influences the effect of ultraviolet-B radiation on leaf litter decomposition

Altered surface ultraviolet-B (UV-B) radiation resulting from a combination of factors that include changes in stratospheric ozone concentrations, cloud cover, and aerosol conditions may affect litter decomposition and, thus, terrestrial nutrient cycling on a global scale. Although litter decomposition rates vary across biomes, patterns of decomposition suggest that UV-B radiation accelerates litter decay in xeric environments where precipitation is infrequent. However, under more frequent precipitation regimes where litter decay rates are characteristically high, the effect of UV-B radiation on litter decomposition has not been fully elucidated. To evaluate this association between moisture regime and UV-B exposure, a litter decomposition experiment was designed for aspen (Populus tremuloides) leaf litter, where conditions that influence both abiotic (photodegradation) and biotic (microbial) processes could be manipulated quantitatively. We found that experimentally increasing UV-B exposure (0, 7.4, and 11.2 kJ m ―2 day ―1 , respectively) did not consistently increase litter decomposition rates across simulated precipitation frequencies of 4, 12, and 24 days. Instead, a UV-B exposure of 11.2 kJ m ―2 day ―1 resulted in a 13% decrease in decomposition rates under the 4-day precipitation frequency, but an increase of 80% under the 24-day frequency. Furthermore, the same UV-B dose increased litter decomposition rates under the 24-day precipitation frequency by 78% even in conditions where microbial activity was suppressed. Therefore, under more xeric conditions, greater exposure to UV-B radiation increased decomposition rates, presumably through photodegradation. In contrast, when decomposition was not moisture-limited, greater UV-B exposure slowed decomposition rates, most likely from the resulting inhibition of microbial activity. Ultimately, these experimental results highlight UV-B radiation as a potential driver of decomposition, as well as indicate that both the direction and magnitude of the UV-B effect is dependent on moisture availability, a factor that may change according to future patterns in global precipitation.
Design of a Helmholtz coil for susceptibility testing using variational calculus and experimental verification

Helmholtz coils are used for high quality susceptibility testing. In this paper a mathematical model is developed which predicts optimum design. The model is compared to experimental results. The model uses a specific area of variational calculus called Lagrangian multipliers. In Lagrangian multipliers we minimize or maximize a function with constraints. We can maximize the Helmholtz resonance frequency with constraints on the magnetic field (magnetic flux density), the electric field, current and impedance. This model will tell us how to design Helmholtz coils to maximize the magnetic field, maximize the self resonance, minimize the electric field, and minimize the number of turns. This model will save designer and builder of Helmholtz coils much time and labor.
Identification of elastic properties of homogeneous, orthotropic vascular segments in distension

Characterization of the constitutive behavior of normal and pathological blood vessel segments could provide the clinician with a means to predict the onset and assess the severity of certain vascular maladies. Many of the constitutive models that have been proposed to date either fail to properly consider certain features of the anatomic structure and function of vascular tissue or are so mathematically complex that their utilization is intractable. We have developed a material identification technique that first required the adaptation and validation of a constitutive law describing the nonlinear, three-dimensional behavior of orthotropic, compressible, hyperelastic vascular sgements. By coupling a nonlinear finite element program and experimental data with a robust nonlinear least-squares regression algorithm, a set of elastic parameters (moduli) is obtained. Regressions on data for a canine carotid artery and rabbit infrarenal aorta yielded coefficients of variation of 0.21 and 0.08, respectively. The estimated moduli demonstrated certain trends found by other investigators: both the canine carotid artery and rabbit aorta were found to be stiffer radially than circumferentially, and the former was found to be stiffer circumferetially than longitudinally. Using these material constants and measured arterial pressures, the stress distribution was computed for each specimen. The predicted radial stress was consistent with a transmural variation of approximately - p (applied luminal pressure) to approximately zero in both specimens, while the circumferential stresses ranged from 2.2p to 0.7p for the canine carotid, and from 6.4p to 3.7p for the rabbit arota. The stress distributions qualitatively agreed with those reported in previous investigations, as well as with certain physiologic observations. Based on the results of our two sample cases, we believe that our technique could be beneficial to the assessment of the three-dimensional, anisotropic behavior of vascular tissue.
Addressing First- and Second-Order Barriers to Change: Strategies for Technology Integration

Although teachers today recognize the importance of integrating technology into their curricula, efforts are often limited by both external (first-order) and internal (second-order) barriers. Traditionally, technology training, for both preservice and inservice teachers, has focused on helping teachers overcome first-order barriers (e.g., acquiring technical skills needed to operate a computer). More recently, training programs have incorporated pedagogical models of technology use as one means of addressing second-order barriers. However, little discussion has occurred that clarifies the relationship between these different types of barriers or that delineates effective strategies for addressing different barriers. If pre- and inservice teachers are to become effective users of technology, they will need practical strategies for dealing with the different types of barriers they will face. In this paper, I discuss the relationship between first- and second-order barriers and then describe specific strategies for circumventing, overcoming, and eliminating the changing barriers teachers face as they work to achieve technology integration.
Intramolecular diels‐alder cyclization into the thiophene ring

Trans-3-(2- and 3-thienyl)allyl alcohols have been prepared from the corresponding acroleins. The esters of these alcohols with phenylpropiolic acid underwent intramolecular Diels-Alder reactions to give the substituted dihydrothianaphthene lactones Va and Vb, respectively.
From dragon to goose: has the Chinese dragon lost its fire?

The state of the world economy is something of a moving feast. Each week, news from the USA, Europe and now China registers a new development, with a growing appreciation of the interconnectedness of the world economy. ‘Understandings’ are often confounded with ‘happy talk’ (what used to be called ‘ideology’) where economic and political actors attempt to manipulate their market standing, agency rating etc., for their own parochial interests. France and England’s recent struggles to ‘dodge the bullet’ of a rating’s agency downgrade are a case in point. Happy talk about China is the latest shoe to drop. The West is beginning to realise that the Chinese Dragon is sicker than we realised.
Biexcitons or drop embryos in CdS, CdSe

The transition probabilityP(K, n) of the reaction $$\left( {\begin{array}{*{20}c} {biexciton} \\ K \\ \end{array} } \right)\begin{array}{*{20}c} \to \\ \leftarrow \\ \end{array} \left( {\begin{array}{*{20}c} {exciton} \\ {K,n} \\ \end{array} } \right) + \left( {\begin{array}{*{20}c} {photon} \\ {q \simeq 0} \\ \end{array} } \right)$$ has been computed in direct-gap semiconductors for several final states of the exciton (1s or 2p)vs. the biexciton kinetic energy. The probabilityP(K, n) is found to decrease strongly withK, whereas it is usually assumed thatP(K, n) is constant in the analysis of many experiments (luminescence of biexcitons, induced formation of biexcitons, gain measurement of the biexciton light) on the basis of a simple calculation. The line shape theory used in the preceding experiments is, therefore, incorrect, especially in semiconductors with exciton of small binding energy (such as CdSe or CdS). The previously proposed interpretation of the so-calledM s band in terms of biexcitons in CdS or CdSe is very questionable on the basis of this calculation and recent picosecond-time-resolved luminescence experiments which cannot be analysed in the biexciton model. We support the interpretation of thisM s band in terms of bound polyexcitons and drop embryo luminescence.
Becoming a Habitual Voter: Inertia, Resources, and Growth in Young Adulthood

This paper reframes our inquiry into voter turnout by making aging the lens through which the traditional resource and cost measures of previous turnout research are viewed, thereby making three related contributions. (1) I offer a developmental theory of turnout. This framework follows from the observation that most citizens are habitual voters or habitual nonvoters (they display inertia). Most young citizens start their political lives as habitual nonvoters but they vary in how long it takes to develop into habitual voters. With this transition at the core of the framework, previous findings concerning costs and resources can easily be integrated into developmental theory. (2) I make a methodological contribution by applying latent growth curve models to panel data. (3) Finally, the empirical analyses provide the developmental theory with strong support and also provide a better understanding of the roles of aging, parenthood, partisanship, and geographic mobility.
On deformation of associative algebras and graph homology

Abstract Deformation theory of associative algebras and in particular of Poisson algebras is reviewed. The role of an “almost contraction” leading to a canonical solution of the corresponding Maurer–Cartan equation is noted. This role is reminiscent of the Homotopical Perturbation Lemma, with the infinitesimal deformation cocycle as “initiator.” Applied to star-products, we show how Moyal's formula can be obtained using such an almost contraction and conjecture that the “merger operation” provides a canonical solution at least in the case of linear Poisson structures.
The photo-oxidation of propionaldehyde

Abstract C2H5CHO vapor was photolyzed with 313 nm radiation at 22 °C in the presence of O2 and O2He, O2N2, O2NO and O2cis-2-C4H8 mixtures. The contents of the reaction mixture were allowed to bleed through a pinhole into a quadrupole mass spectrometer providing for continous monitoring of the C2H5OH and C2H5C(O)O2H produced. CO, CO2, C2H4 and CH3CHO concentrations were determined by gas chromatography. From CO quantum yield determinations we found that the only photolytic process of importance is the following: The CO quantum yields also indicate that the reactive state of C2H5CHO is pressure quenched, and the half-quenching pressures for the various reactant gases were measured. The primary quantum yield in 1 atm of air is 0.30 ± 0.05. The data suggest that the reacting state is a vibrationally excited triplet state which consists of levels which are quenched with different efficiencies by any quenching gas. The more rapidly quenched leves account for about 40% of the total, while the less rapidly quenched levels account for about 60% of the total. Large quantum yields were measured for CO2, C2H5OH and C2H5C(O)O2H indicating a chain reaction initiated by abstraction of the aldehydic hydrogen of C2H5CHO by C2H5O radicals. The C2H4 quantum yields are dependent on the total pressure, and we believe that C2H4 is produced from the decomposition of vibrationally excited C2H5CO3 radicals: The deactivated C2H5CO3 radicals will either react with HO2 or C2H5CHO or at the walls to produce C2H5CO3H, or ultimately decompose to CO2 + C2H5. We found that the following reactions are unimportant at 22 °C:
Henry (Hank) J. Moore (1928–1998)

Henry (Hank) J. Moore, a member of the AGU Planetary Sciences section, died of a heart attack on September 21, 1998. He was in Utah while on a family trip to visit his daughter. His 70th birthday occurred just 3 weeks before his death. Henry, who was born in Albuquerque, New Mexico, took great pride in having found and visited the small town of Albuquerque in the Extremadura region of Spain, noting the geologic similarities between that part of Spain and his birthplace in America. Henry, known for his contributions to the Apollo,Viking, Magellan, and Mars Pathfinder missions, attributed his career to a chance encounter with Gene Shoemaker in 1960. Henry was completing his Ph.D. work in geology at Stanford University and Gene obviously had spotted Henry's keen analytical mind. I suspect this pivotal meeting was far from a chance encounter.
Automatic generation of analytical matrix elements for electron-atom scattering

Abstract A code which can be used to automatically generate entire sets of analytical matrix elements of the instantaneous electrostatic interaction potential between the projectile electron and the target atom is described. The code can be used at present for both hydrogen and helium target atoms. In the case of hydrogen, the present code Vij generalizes and extends an earlier code of Jamison [1]; while in the case of helium, Hartree-Fock frozen-core wave-functions are used to represent the two-electron wavefunctions. When an entire set of matrix elements is generated, a complete set of FORTRAN subroutines is produced which can be directly incorporated into the code MET_cross used to solve the multichannel eikonal theory (see accompanying paper). A principal application of the code Vij is to aid the elucidation of the systematic trends observed in transitions among metastable states in electron-atom collisions by studying the functional form of the underlying interaction matrix elements.
Educating primary care chiropractic physicians

The Council on Chiropractic Education (CCE), the U.S.Department of Education’s specialized accreditingagency for chiropractic education, has established stan-dards for education of chiropractic physicians that in-clude specific reference to primary care. In the Forwardto the Standards, the following statement appears: “Adoctor of chiropractic is a primary care physician andclinician whose purpose, as a practitioner of the healingarts, is to help meet the health needs of individualpatients and of the public, giving particular attention tothe structural and neurological aspects of the body....Asagatekeeper for direct access to the health de-livery system, the doctor of chiropractic’s responsibilitiesas a primary care physician include wellness promotion,health assessment, diagnosis and the chiropractic man-agement of the patient’s health care needs. When indi-cated, the doctor of chiropractic consults with, co-manages, or refers to other health care providers” (1).Section H of the CCE standards charge the educationalprograms with the following responsibility: “DCPs ac-credited by the COA of the CCE prepare students to beprimary care chiropractic physicians serving as a portalof entry for patients to access illness and wellness-related care” (1). The CCE Standards for accreditationensure that all doctor of chiropractic degree programsmeet the minimum educational expectations of a pri-mary care provider curriculum. The adoption of the“primary care physician and clinician” status by the CCEhas been a relatively new development and the manychiropractic institutions and programs within the U.S.are at varying levels of implementation. In some cases,there has been marked resistance to the primary carestatus.As has been indicated by other speakers at this summitmeeting, there are many different definitions of primarycare. The Institute of Medicine (IOM) definition is prob-ably the simplest: “Primary care is the provision ofintegrated, accessible health care services by clinicianswho are accountable for addressing a large majority ofpersonal health care needs, developing a sustained part-nership with patients, and practicing in the context offamily and community” (2). The IOM definition doesnot stipulate which health-care providers can be classi-fied as primary-care clinicians. This can be contrastedwith the definition provided by the American Academyof Family Physicians, which differentiates between pri-mary-care physicians (M.D. and D.O. only) and limitedprimary-care providers (which include nurse practitio-ners, physician assistants, or health-care providersworking in close consultation with a primary-care phy-sician (3). In this paper, no attempt will be made todefine a primary-care clinician, but instead we will lookat the educational needs of training these providers.
What is DIPNECH

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare disorder that is being diagnosed more frequently with the increasing availability of advanced imaging and more accurate histopathology. It occurs most commonly in nonsmoking, middle-aged women. High-resolution computed tomography (HRCT) findings include mosaic attenuation due to constrictive bronchiolitis and small (<5 mm) randomly distributed pulmonary nodules. It is important to recognize this condition as it is considered a precursor of peripheral carcinoid tumors. This article will present a case of this uncommon condition with review of the literature, imaging findings, and clinical presentation.
Theoretical considerations of biaxial stretching of viscoelastic fluid sheets with application to plastic sheet forming

A theoretical analysis of biaxial stretching of viscoelastic fluid sheets has been carried out. In the first part of the paper emphasis is placed on the transient buildup of stress in an initially virgin material when it is subjected to constant deformation rate stretching. At low deformation rates the stress builds up slowly to a steady state value. At higher deformation rates, the stress rises to infinity. The influence of the detailed form of the constitutive equation of the stress buildup is described. Stress buildup under other deformation conditions and stress relaxation following deformation are also considered. In the second part of the paper, the possibility of growth of defects originating as either geometric or material property nonhomogeneities is investigated.
LUPRON TREATMENT OF PRECOCIOUS PUBERTY (CPP) HAS NOT PRODUCED LOSS OF BONE MINERAL

We tested the hypothesis that GnRH agonist treatment of CPP is associated with loss of bone mineral density (BMD) and content (BMC) after young women treated with GnRH agonists were reported to lose up to 6% BMD in the first treatment year similar to that seen during menopause. We determined lumbar spine (L1-L4) BMD (g/cm2) and BMC (g) by dual photon absorptiometry and measured growth parameters and blood Ca (mg/dl), alk. phos. (AP, mU/ml) and integrated growth hormone (GH, ng/ml) on CPP patients before and after (3 of our 6 patients to date) six months treatment with the GnRH agonist LUPRON (TAP Pharm., 4-8 ug/kg SC qD). Our patients (3 girls 5-8 yr, 9-10 yr bone age [BA]; 3 boys 3-8 yr, 7-10 yr BA) were Stage 3-4 upon entering the study with informed consent. All 6 had similar basal BMD (.724±.05, SEM). Despite reduction of V or T toward prepubertal levels, growth rates and BMC did not decline and GH and BMD increased while Ca and AP decreased. We conclude that early, partial suppression of CPP with LUPRON is not associated with loss of BMD or BMC. Followup with further suppression of CPP should help to distinguish between variable time courses of end organ responses or therapeutic selectivity.
Serotonin is necessary for short-term modulation of the exercise ventilatory response

The exercise ventilatory response is augmented during conditions of increased respiratory dead space (delta Vd), a phenomenon that we refer to as short term modulation (STM). To test the hypothesis that serotonin is necessary in the mechanism underlying STM, experiments were conducted on ten awake goats. Ventilation, CO2 production and PaCO2 were measured at rest and during treadmill exercise (4 km/h, 5% grade), with and without delta Vd (0.25 L), before and after systemic administration of the serotonin receptor antagonist, methysergide maleate (n = 6; 1 mg/kg, i.v.), or the tryptophan hydroxylase inhibitor, p-chlorophenylalanine (PCPA; n = 4; 100 mg/kg, i.v.). Pre-methysergide: (1) PaCO2 decreased from rest to exercise to a similar degree with (-1.9 mmHg) and without (-1.8 mmHg) delta Vd; (2) the exercise ventilatory response increased 59% +/- 13% (P < 0.01) with delta Vd, accounting for similar exercise PaCO2 regulation and demonstrating STM; and (3) effects of delta Vd on exercise tidal volume and frequency responses were inconsistent. Post-methysergide: (1) there were no significant effects on ventilation or PaCO2 at rest or during exercise in control (mask) conditions; (2) the exercise ventilatory response was unaffected by delta Vd, thereby allowing PaCO2 to increase 4.1 +/- 3.0 mmHg from rest to exercise (P < 0.05); and (3) with delta Vd during exercise, the tidal volume response was increased, but was offset by a decreased frequency response. Following PCPA (16-24 h): (1) hyperventilation was evident at rest and during exercise; (2) the exercise ventilatory response was augmented, indicating STM; and (3) the exercise ventilatory response with delta Vd was not affected further, allowing PaCO2 to increase from rest to exercise and indicating an inability to elicit further STM. These data suggest that serotonin is necessary for short term modulation of the exercise ventilatory response with increased respiratory dead space, although the location of relevant serotonin receptors is not yet clear.
Robot arm‐wrist coordination. Part 2. Design guidelines

In the companion article (Part 1), we developed a mathematical framework that provides for the analysis and quantitative rating of arm-wrist coordination. The objective of this article is to exploit this framework and formulate manipulator design guidelines for effective arm-wrist coordination and task execution. We explore various arm and wrist designs and quantify their performance in terms of meeting the two design objectives of efficient arm-wrist coordination and robot flexibility. Numerical simulation experiments highlight the measurable effects of both the fixed manipulator geometry and changing robot configuration on arm-wrist coordination and demonstrate the impact of the design guidelines on robot performance.
Potential of microalgae oil from Dunaliella tertiolecta as a feedstock for biodiesel

Abstract Alternative, non-food based biomass fuel feedstock development is vital for our national security, economy and the environment. Microalgae are among the most promising of these alternatives. Microalgal cell growth rates and metabolic products are affected by a combination of environmental parameters. In this work, the influences of light source, light intensity, CO2 concentration, and photoperiod on the growth of Dunaliella tertiolecta (D. tertiolecta) were studied. The effects of these environmental parameters on the lipid content and fatty acid composition of D. tertiolecta were also investigated. Red light-emitting diodes (LEDs), white LEDs, and fluorescent lights were all found to be effective for algal growth. Increasing light intensity resulted in significantly more rapid algal growth, and increasing the period of light also significantly increased biomass productivity. Similar growth rates were observed for 2%, 4%, and 6% CO2-concentrations. The different light sources and intensities were found to have no significant effect on FAME composition of D. tertiolecta. Methyl linolenate and methyl palmitate were found to be the major components of FAME produced from D. tertiolecta oil. D. tertiolecta and its derived oils should be a suitable feedstock for biofuel production.
Spin-poiarized EELS of surfaces

Abstract The spin dependence of electron energy loss processes in Ni is studied in detail by spin polarized electron energy loss spectroscopy (SPEELS). Exchange scattering plays a dominant role for small energy losses with a large contribution due to Stoner excitations. The angle and energy dependence of spin asymmetries can be described by the superposition of nearly isotropic impact scattering and largely spin independent dipole losses, strongly peaked around specular. The absence of a significant temperature dependence in the spin asymmetry spectrum is consistent with the persistence of local magnetic moments and a spin-split electronic structure at (and above) T C . It is suggested that the observed spin asymmetries give rise to a spin-dependent electron mean-free-path at low energies and play a role in the spin polarization enhancement and the surface sensitivity of low-energy secondary electrons.
Infertility and forager demography

A model of the effects of infectious sterility on reproductive histories of women was presented to criticize the recent treatment of comparative forager population statistics in which Blurton Jones et al. suggest that Hadza fertility is higher than ]Kung fertility because the Hadza have more food and a lighter workload. Infectious infertility in the ]Kung is a better explanation of the difference. Mean length of the reproductive span is a better indicator of the presence of infectious infertility than the primary sterility rate. A Markov chain model of reproduction had 4 states: at risk pregnant lactating and sterile. The probability that a woman becomes sterile before she has a birth is in fair agreement with Howells suggestion that 10% of ]Kung women never had a live birth. This agreement suggests that there was little exposure to sterility before the onset of full fecundity in this population. It is likely that the sexual partners of young ]Kung women were age mates rather than older men who would be more likely to transmit infection. The ]Kung share their land in Botswana with the Herero who suffered severe infertility before antibiotics became available in the 1960s. In older Herero cohorts primary sterility was only 15% while sterility at every parity above zero was 25%. The cumulative effect of infertility in the Herero was severe: completed family size in older cohorts was less than 3 and the mean age at last birth was 27. The Herero example shows that the overall effects of sterility on reproduction and the level of primary sterility are not simply related.
Design of concurrent error detectable current-mode A/D converters for real-time applications

Analog MOS circuits are becoming increasingly sophisticated in terms of checking and correcting themselves. Self-correcting, self-compensating, or self-calibrating techniques eliminate errors traditionally associated with analog circuits. For real-time applications, however, it is rather difficult to achieve validation of the data generated from analog-to-digital (A/D) converters in the presence of faulty switching element(s). Conventionally, the validation is accomplished by using a high resolution and high accuracy D/A converter and a window comparator; i.e., the validation must highly depend on the reliability of both the D/A converter and the window comparator. In this paper, a novel current-mode A/D converter design with concurrent error detection (CED) capability is presented. The A/D converter does not need well-matched components and high-gain amplifiers. Results show that the proposed design can detect all the transient faults and most of the permanent faults. The proposed design allows users to easily switch to the normal operation mode where CED capability is not used, without causing any performance degradation.
Weak and strong ignition. II. Sensitivity of the hydrogenoxygen system

Abstract This paper identifies the physical and chemical mechanisms which cause certain mixtures of hydrogen, oxygen, and argon to be very sensitive to sound wave and entropy (temperature) perturbations. Detailed simulations of the effects of sound waves in typical mixtures are used to show explicitly the effects of such fluctuations on the chemical induction time. A quantity, τmax, is defined which represents the maximum variation produced in the chemical induction time of a system, given the amplitude and frequency of a perturbation. It is observed that these perturbations may cause ignition to occur unevenly in such mixtures and this leads to ignition which appears spotty. Using detailed numerical simulations and a generalized induction parameter model derived from it, τmax is evaluated and a criterion is developed for spotty and smooth ignition behind reflected shock waves. These effects are related to weak and strong ignition observed in shock tube experiments.
Infantile tibia vara.

We studied the applicability of Langenskiold's classification to a predominantly nonwhite population with infantile tibia vara. Age at presentation was younger than that in previously published studies. Forty-seven tibiae averaging 6 years 7 months of follow-up had 66% good results. Poor results increased in proportion to stage at presentation. Brace treatment for early lesions was only 50% effective. Single tibial osteotomy before 4 years of age gave good results in 85% of tibiae, and multiple osteotomies gave good results between 4 and 8 years of age. One-half of tibiae treated with osteotomy developed recurrent varus. This review documents earlier stages at presentation, a more malignant course, and poorer results than Langenskiold's series would suggest. We question the accuracy of Langenskiold's estimate of prognosis when applied to this patient group.
"Sternberg-reed" giant cells of Hodgkin's Disease: cultivation in vitro, heterotransplantation, and characterization as neoplastic macrophages.

Cells from the involved spleens of 25 patients with Hodgkin's disease have been grown in long-term culture and compared with normal spleen macrophage cultures from control cases. The Hodgkin's spleen cell culture contained mono-, bi-, and multi-nucleate giant cells, many closely resembling Sternberg-Reed cells, which were adherent, phagocytically active and neoplastic by the dual criteria of aneuploidy and heterotransplantability. Lysozyme secretion was consistently observed in all Hodgkin's cultures tested. The giant cells possessed both Fc and complement (c3b) receptors, and lacked lymphocyte markers such as (c3b) receptors, surface IgM, and the capacity to form E-rosettes. Binucleate and multinucleate cells, as well as mononuclears, were capable of active DNA synthesis, and binuclear mitotic figures were observed. It is concluded that these cells are the in vitro descendants of the Sternberg-Reed and Hodgkin neoplastic cell population, and that they are derived from macrophages or closely related cells of the mononuclear phagocyte system.
Automation Process in Nigerian Academic Libraries

Automation process in Nigerian libraries has been the subject of discussion. this paper discussed the automation process in Nigerian academic libraries in regards to information and communication technologies in libraries, benefits of library automation, automation in library, need of library automation, areas of library automation, scope of system integration, choice of hardware, constraints and how the library can cope with the new trend in librarianship.
Synthesis and Characterization of Aplysinopsin Analogs

Three aplysinopsin analogs were synthesized by reacting 5-bromo-5-fluoro- and 6-bromoindole-3-carboxaldehyde with either creatinine or 2-imino-1,3-dimethyl-imidazolidin-4-one or 2-imino-1-methyl-3-ethylimidazolidin-4-one Single crystal structures on 5-bromo-4′-de-N-methylaplysinopsin DMF solvate [from creatinine, space group P21/n, lattice parameters a = 13.117(3) A, b = 8.6663(15) A, c = 14.743(3) A, β = 99.538(10)° at 173 K], 5-fluoroaplysinopsin DMF solvate [from 2-imino-1,3-dimethyl-imidazolidin-4-one, space group P21/c, lattice parameters a = 11.114(3) A, b = 19.118(2) A, c = 8.503(2) A, β = 112.290(7)°], and 6-bromoindole-3-carboxaldehyde (space group P21/n, lattice parameters a = 7.657(2) A, b = 7.933(2) A, c = 13.521(3) A, β = 99.046(13)°) have been determined. Characterizations include spectrometric identifications employing IR, UV, HRMS, and 1H and 13C NMR. 5-Bromo-4′-de-N-methylaplysinopsin and 5-fluoroaplysinopsin exist in the E configuration. Single crystal X-ray structural analyses were carried out on 5-bromo-4′-de-N-methylaplysinopsin, 5-fluoroaplysinopsin, and 6-bromoindole-3-carboxaldehyde.
Diatom communities along stream longitudinal gradients

SUMMARY 1. Summer diatom communities on artificial substrates were sampled weekly for a month in three first- to sixth-order tributaries of the Kentucky River to determine how community structure varied with stream size. 2. Diatom cell abundances were generally higher in the headwaters. Species diversity increased in a downstream direction in two of the streams, and in an upstream direction in the third. However, diversity in general seemed more closely related to current regimes than to stream size per se, with highest species diversity at intermediate current velocities. 3. Variation in diatom accumulation rates was greater in downstream communities than in the headwater assemblages of two streams, suggesting that downstream communities may experience greater fluctuations in abundance, at least under low-flow conditions. 4. Patterns of species distributions suggested a relationship between morphological growth forms (guilds) and stream size, as well as the influence of current. Achnanthes spp., Eunotia spp., erect, and stalked taxa were more commonly associated with headwater assemblages. Filamentous and centric diatoms occurred with greater frequency downstream.
A revised picture of the structure of the “monsoon” and land ITCZ over West Africa

This article presents an overview of the land ITCZ (Intertropical Convergence Zone) over West Africa, based on analysis of NCAR–NCEP Reanalysis data. The picture that emerges is much different than the classic one. The most important feature is that the ITCZ is effectively independent of the system that produces most of the rainfall. Rainfall linked directly to this zone of surface convergence generally affects only the southern Sahara and the northern-most Sahel, and only in abnormally wet years in the region. A second feature is that the rainbelt normally assumed to represent the ITCZ is instead produced by a large core of ascent lying between the African Easterly Jet and the Tropical Easterly Jet. This region corresponds to the southern track of African Easterly Waves, which distribute the rainfall. This finding underscores the need to distinguish between the ITCZ and the feature better termed the “tropical rainbelt”. The latter is conventionally but improperly used in remote sensing studies to denote the surface ITCZ over West Africa. The new picture also suggests that the moisture available for convection is strongly coupled to the strength of the uplift, which in turn is controlled by the characteristics of the African Easterly Jet and Tropical Easterly Jet, rather than by moisture convergence. This new picture also includes a circulation feature not generally considered in most analyses of the region. This feature, a low-level westerly jet termed the African Westerly Jet, plays a significant role in interannual and multidecadal variability in the Sahel region of West Africa. Included are discussions of the how this new view relates to other aspects of West Africa meteorology, such as moisture sources, rainfall production and forecasting, desertification, climate monitoring, hurricanes and interannual variability. The West African monsoon is also related to a new paradigm for examining the interannual variability of rainfall over West Africa, one that relates changes in annual rainfall to changes in either the intensity of the rainbelt or north–south displacements of this feature. The new view presented here is consistent with a plethora of research on the synoptic and dynamic aspects of the African Easterly Waves, the disturbances that are linked to rainfall over West Africa and spawn hurricanes over the Atlantic, and with our knowledge of the prevailing synoptic and dynamic features. This article demonstrate a new aspect of the West Africa monsoon, a bimodal state, with one mode linked to dry conditions in the Sahel and the other linked to wet conditions. The switch between modes appears to be linked to an inertial instability mechanism, with the cross-equatorial pressure gradient being a critical factor. The biomodal state has been shown for the month of August only, but this month contributes most of the interannual variability. This new picture of the monsoon and interannual variability shown here appears to be relevant not only to interannual variability, but also to the multidecadal variability evidenced in the region between the 1950s and 1980s.
Transformation of Solanum brevidens using Agrobacterium tumefaciens

Leaf pieces of in vitro-cultured plantlets of the wild potato species Solanum brevidens Phil. were cocultivated with Agrobacterium tumefaciens that contained nptII and uidA genes on the disarmed plasmid pBI121. Independent transgenic shoots were regenerated from solidified and liquid medium that contained 50 mg l−1 kanamycin. Two Agrobacterium strains were investigated for transformation efficiency. GV2260, which contained p35SGUSINT, resulted in a 11% transformation frequency, compared with 1% using LBA4404. Transformation rates were 7% in liquid culture and 3% on solidified medium. All kanamycinresistant, putatively transformed plantlets were confirmed positive by histochemical GUS assays. GUS activity in 22 independently transformed plants was quantified by fluorometric assay. Southern analysis of randomly selected transgenic plants showed that each transgenic plant contained at least one copy of the uidA gene.
Knowledge management: how to foster creation and flow

The purpose of this article is to help managers and scholars understand the state‐of‐the‐art in knowledge management (KM) and how it is likely to develop further. The paper draws on many examples and original research to outline a conceptual framework describing the evolution of KM. KM is presently limited because the nature of knowledge makes it difficult to actually “manage.” Instead, the field is moving toward an organic form of management focusing on three main concepts: “e‐organizations” that automatically integrate all information and knowledge, “self‐organizing systems” composed of small entrepreneurial units that draw out creative knowledge from the bottom up, and “corporate communities” that use stakeholder knowledge to improve strategy. Managers should develop these organic organizational forms because they encourage the natural creation and flow of knowledge more effectively.