cssi/SciSciGPT-SciSciNet huggingface dataset:
The Oxidation Kinetics of Continuous Carbon Fibers in a Cracked Ceramic Matrix Composite

Experimental observations and results suggest two primary regimes as a function of temperature, i.e., diffusion and reaction controlled kinetics. Thermogravimetric analysis of carbon fiber in flowing oxygen gave an activation energy of 64.1 kJ/mol in the temperature range of 500 to 600 C and an apparent activation energy of 7.6 kJ/mol for temperatures from 600 to 1400 C. When C/SiC composite material was unstressed, matrix effects at temperatures from 900 to 1400 C protected the internal fibers. When under stress, self-protection was not observed. Increasing the stress from 10 to 25 ksi caused a 67 to 82 percent reduction in times to failure at temperatures from 750 to 1500 C. Based on experimental results, observation, and theory, a finite difference model was developed, which simulates the diffusion of oxygen into a matrix crack that is bridged by carbon fibers. The model allows the influence of important variables on oxidation kinetics to be studied systematically, i.e., temperature, reaction rate constant, diffusion coefficient, environment, and sample geometry.
Aggregating predictions from experts: A review of statistical methods, experiments, and applications

Forecasts support decision making in a variety of applications. Statistical models can produce accurate forecasts given abundant training data, but when data is sparse or rapidly changing, statistical models may not be able to make accurate predictions. Expert judgmental forecasts-models that combine expert-generated predictions into a single forecast-can make predictions when training data is limited by relying on human intuition. Researchers have proposed a wide array of algorithms to combine expert predictions into a single forecast, but there is no consensus on an optimal aggregation model. This review surveyed recent literature on aggregating expert-elicited predictions. We gathered common terminology, aggregation methods, and forecasting performance metrics, and offer guidance to strengthen future work that is growing at an accelerated pace.
Electron paramagnetic resonance study of type-II silicon clathrate with low sodium guest concentration

An electron paramagnetic resonance (EPR) study of type-II silicon (Si) clathrate with low sodium (Na) guest concentration provides insights into the properties of this cagelike Si allotrope and into Na as an $n$-type dopant. An EPR line arising from unterminated Si bonds in a disordered Si phase is identified in the system. The presence of this amorphouslike component helps explain the thermally activated, hopping-related conductivity that has long been observed in the system but which has been poorly understood. This study also identifies ``superhyperfine'' lines surrounding each Na hyperfine line due to interactions of the donor electron with a $^{29}\mathrm{Si}$ nucleus on the cage and confirms the identification of hyperfine lines due to interactions of two neighboring Na nuclei. Analysis of the strength of these interactions shows that the electron wave function associated with the Na donor extends onto surrounding cages consistent with identification of Na as a shallow donor, and provides quantitative evidence of Na clustering.
A Microneedle Technology for Sampling and Sensing Bacteria in the Food Supply Chain

Food quality monitoring, particularly, the detection of bacterial pathogens and spoilage throughout the food supply chain, is critical to ensure global food safety and minimize food loss. Incorporating sensors into packaging is promising, but it is challenging to achieve the required sampling volume while using food‐safe sensor materials. Here, by leveraging water‐based processing of silk fibroin, a platform for the detection of pathogenic bacteria in food is realized using a porous silk microneedle array; the microneedle array samples fluid from the interior of the food by capillary action, presenting the fluid to polydiacetylene‐based bioinks printed on the backside of the array. Through the colorimetric response of bioink patterns, Escherichia coli contamination in fish fillets is identified within 16 h of needle injection. This response is distinct from spoilage measured via the increase in sample pH. It is also shown that the microneedles can pierce commercial food packaging, and subsequently sample fluid and present it to the sensor, enabling the adaptation of the technology downstream in food supply chains such as in stores or at home. This study highlights that regenerated structural biopolymers can serve as safe materials for food contact and sensing with robust mechanical properties and tailored chemistry.
Exploring the development of humble leaders in the context of agriculture

The complexity of the world today requires leadership that is interconnected rather than self-serving. This is particularly important within the context of agriculture, a field at the forefront of the complex problems associated with the impact of climate change. In recent years, the role virtues play in effective leadership has gained a significant amount of attention. One particular virtue that has seen increased attention in the leadership research is humility. Humility has been identified as a way to counteract the negative outcomes of self-serving leadership, namely, unethical practices and leader narcissism. Over the past several decades, researchers and scholars have begun to shed light on the many benefits this elusive virtue brings to leadership, however, many questions remain, notably, “How do humble leaders develop their leadership?” The present qualitative study found that humble agriculture leaders develop their leadership style through (a) the development of strong personal values, (b) investments in human and social capital, and (c) supportive feedback. The findings from this research provide recommendations for agricultural leadership educators to consider when building leadership programs that have the goal of developing humble leaders ready to address complex problems in the context of agriculture and natural resources.
Elucidating the Relationship Between Insomnia, Sex, and Cardiovascular Disease:

Sex differences in cardiovascular disease (CVD) mortality have been attributed to differences in pathophysiology between men and women and to disparities in CVD management that disproportionately a...
Effect of weight cycling on progression of knee joint degenerative disease in overweight and obese individuals: 4-year mri data from the osteoarthritis initiative

Author(s): Joseph, GB; Ramezanpour, S; McCulloch, CE; Nevitt, MC; Lynch, JA; Lane, NE; Pedoia, V; Majumdar, S; Link, TM
Thermal management of electronics during continuous and intermittent operation mode employing phase change material-based heat sinks – Numerical study

Transient numerical studies are performed for the effective medium of phase change material filled with thermal conductivity enhancers for passive thermal management applications during continuous and intermittent operation. Phase change material melting and solidification was modeled using a simplified model assuming conduction-dominated heat transfer. n-eicosane is used as the phase change material, and copper is the thermal conductivity enhancer. Effect of aspect ratio is discussed for a continuous mode of operation. Different parameters like aspect ratio, power input, power on and OFF-time during intermittent operation are studied and discussed. We demonstrate the effect of these parameters on the thermal performance of the composite medium both during continuous and intermittent operation and discussion on the optimum volume fraction in different scenarios. Our results elucidate that, for any aspect ratio of the composite, the optimal PCM composite design in terms of volume fraction is primarily a function of the magnitude and duration of the pulsed load. Furthermore, a PCM usefulness merit is defined to understand the minimum amount of PCM required for safe operation under intermittent loading conditions.
Affective Aggression: The Role of Stress, Pain, and Negative Affect

Publisher Summary This chapter provides a brief outline of the cognitive neoassociationistic framework. The activated flight-associated syndrome (or network) is consciously experienced (perceived) as fear, whereas the activated fight-linked syndrome is felt as annoyance or irritation at relatively weak levels or anger at more intense levels. The best known analysis of the effects of frustrations was spelled out in 1939 by a team of social scientists at Yale University led by John Dollard, Leonard Doob, and Neal Miller. They defined frustration as an obstacle to the attainment of an expected gratification rather than as an emotional reaction. They also advanced two general propositions regarding the relationship between thwartings and the instigation to aggression: every frustration produces instigation to aggression, an urge to harm someone, principally but not only the perceived source of the goal blocking; and every aggressive action supposedly can be traced back to prior frustrations. However, soon after the theory was first published, Miller amended the first proposition, acknowledging that the inability to reach an expected goal can have nonaggressive as well as aggressive consequences.
Developmental biology: The worm keeps turning

The roundwormCaenorhabditis elegans is a unique and useful model for studying animal development. The formation of the roundworm's 558 cells from a few embryonic parent cells is a process that does not vary from embryo to embryo. A new report shows that the gene lit-1helps to maintain this remarkable invariance by maintaining the correct anterior and posterior fates of embryonic cells.
A New Method of Designing Time-varying, Linear Feedback Systems†

ABSTRACT A method of employing a new transform technique in the design of discrete-time, time-varying, linear feedback systems is presented. The chief advantage of this design method is that it allows much of the insight already developed for time-invariant linear systems to be carried over to time-varying linear systems. The design method presented complements the one previously presented by Naylor and Waltz (1966).
A SAW-based liquid sensor with identification for wireless applications

The development of a shear horizontal surface acoustic wave (SH-SAW) liquid sensor with identification (ID) for wireless applications is described. Moreover, a novel feature of "write capability" for this sensor is proposed. The SH-SAW passive sensor has a delay line configuration with a sensing area. The sensor is fabricated on a lithium tantalate (LiTa03) substrate, which is Y-cut with rotations specified between about 36° around the X-axis. The principle of detection is based on the attenuation and time delay between the signals. The sensor is encoded according to partial reflections of an interrogation signal by metal reflectors placed on both side of the interdigital transducers (IDT). The structure of the sensor, the principle of the wireless communication, the detection process and testing results are presented.
Magnetotransport properties of antiferromagnetic YBa2Cu3O6.25 single crystals

Abstract In-plane Δρ ab / ρ ab and out-of-plane Δρ c / ρ c magnetoresistivities of antiferromagnetic YBa 2 Cu 3 O 6.25 single crystals were measured in magnetic fields H applied along the ab -plane. Δρ ab / ρ ab is a superposition of two components: The first component is strongly in-plane anisotropic, changing sign from negative when H ∥ I to positive when H ⊥ I . The second component is positive, quadratic in H , and isotropic in the ab -plane. Δρ c / ρ c displays a fourfold symmetry upon in-plane rotation of the magnetic field, with maxima along the easy axes of antiferromagnetic spin ordering and minima along unfavorable directions of spin orientation (45° from the Cu–O–Cu bonds).
Hammersley's interacting particle process and longest increasing subsequences

In a famous paper [8] Hammersley investigated the lengthL n of the longest increasing subsequence of a randomn-permutation. Implicit in that paper is a certain one-dimensional continuous-space interacting particle process. By studying a hydrodynamical limit for Hammersley's process we show by fairly “soft” arguments that limn ′1/2 EL n =2. This is a known result, but previous proofs [14, 11] relied on hard analysis of combinatorial asymptotics.
Update on Imaging of the Lacrimal Drainage System

Epiphora is a common problem seen by the ophthalmologist. There are numerous etiologies of a watering eye, and the underlying diagnosis is not always clear. A variety of in-office examination techniques and procedures exist to aid with diagnosis and determination of appropriate therapy, but sometimes the diagnosis remains elusive, or an instituted therapy fails. Lacrimal imaging, particularly in these cases, can be helpful in assessing the function and anatomy of the lacrimal drainage system. This review serves to examine the literature of the last 10 years concerning imaging of the lacrimal drainage system.
Heat transfer analysis of fuel assemblies in a heterogeneous gas core nuclear rocket

Heat transfer problems of a heterogeneous gaseous core nuclear rocket were studied. The reactor core consists of 1.5-m long hexagonal fuel assemblies filled with pressurized uranium tetrafluoride (UF4) gas. The fuel gas temperature ranges from 3500 to 7000 K at a nominal operating condition of 40 atm. Each fuel assembly has seven coolant tubes, through which hydrogen propellant flows. The propellant temperature is not constrained by the fuel temperature but by the maximum temperature of the graphite coolant tube. For a core achieving a fission power density of 1000 MW/cu m, the propellant core exit temperature can be as high as 3200 K. The physical size of a 1250 MW gaseous core nuclear rocket is comparable with that of a NERVA-type solid core nuclear rocket. The engine can deliver a specific impulse of 1020 seconds and a thrust of 330 kN.
An educational strategy for teaching standardized nursing languages.

PURPOSE. The aim of this paper is to describe an educational strategy for teaching standardized nursing languages (SNL) used in both the classroom and clinical components of a psychiatric–mental health nursing course at the associate degree level. DATA SOURCES. Data included a review of the relevant literature, teaching experiences, and faculty and student experiences. DATA SYNTHESIS. Enhancing associate degree student nurses' competency regarding diagnosis and interventions is essential to influence positive health outcomes. Use of diagnostic, outcome, and intervention classifications for learning nursing care promotes critical thinking, individualization of nursing care, and students' fluency with SNL. One possible teaching strategy to assist students to learn and use SNL was implemented through the use of a faculty-developed Student Nurse Documentation Packet. CONCLUSIONS. The educational strategy provided students opportunities to enhance their experience with the SNL to plan and document care of individuals experiencing psychiatric–mental health problems. IMPLICATIONS FOR NURSING. The educational strategy used in this program was judged to be successful. Research is needed to provide empirical evidence of the efficacy of this pedagogical strategy for increasing knowledge and enhancing students' competency.
On the “Slow Mode” Mechanism in ENSO-Related Coupled Ocean–Atmosphere Models

Abstract A linear perturbation, coupled ocean–atmosphere model is revisited for further insights into the El Nino–Southern Oscillation phenomenon. The model oscillates as a slow, eastward propagating mode interpreted as a divergence mode, whose energetics are controlled by the ocean. Growth requires that the work performed by the wind stress minus the work required to effect the ocean divergence exceeds the loss terms. The intrinsic scale of the atmosphere relative to the basin width is important. For sustainable oscillations, the ocean basin must be large enough so that oppositely directed divergence can develop on opposite sides of the basin. The global aspect of the atmospheric pressure field suggests that continental heating may provide either a direct source affecting adjacent oceans, or a connection between oceans. The important model parameters are the coupling and warming coefficients and the ocean Kelvin wave speed. The importance of the Kelvin wave speed derives from its specification of the bac...
Cross section and asymmetry in the deuteron pickup reaction C12(p, d)C11 at 145 MeV

Abstract A carbon target was bombarded with polarized protons of average energy 145 MeV and cross sections and asymmetries were measured for deuterons emerging at angles between 5° and 40° to the incident beam. The asymmetry is small at angles less than 15°, but rises rapidly to become nearly 100% at 40°. The results for the cross sections are in agreement with recent calculations including multiple scattering corrections to the impulse approximation. They show that multiple scattering effects dominate at large angles and prevent a search for high momentum components by this method.
Adsorption and reorientation kinetics of lysozyme on hydrophobic surfaces

Using total internal reflectance fluorescence (TIRF), we observe that lysozyme adsorption onto hydrophobic surfaces can exhibit kinetic overshoots at some conditions, while, at lower free solution concentrations or flow rates over the surface, the coverage monotonically approaches its final value. This behavior is explained by an interfacial relaxation from an end-on to a side-on orientation, which occurs by rollover and not by the displacement of end-on adsorbed proteins by side-on adsorbing proteins. Rollover and displacement models are compared with data to prove this point. Ultimately, we quantitatively predict the kinetic traces for a variety of different adsorption histories (free solution concentration, flow rate, interruption of adsorption by flowing solvent) using a rollover model with reversible transport-limited adsorption of end-on oriented lysozyme and a single rollover rate constant.
Hybridization and its influence on the electronic properties of UA12

Abstract Doping experiments in UA1 2− x M x , with MGa, Si or Mn, have been carried out, and the single-phase samples were characterized by magnetic susceptibility, χ, and low temperature specific heat, C . The parameter important for the relatively large γ and the T 3 ln T spin fluctuation term in the specific heat appears to be the interatomic spacing rather than either coherence on the Al sublattice or the particular electronic character of the dopant atom.
Management of a floating sternum after repair of pectus excavatum

Abstract Purpose: The aim of this study was to examine the authors' experience with patients who have floating sternum after correction of pectus excavatum via the classical Ravitch procedure. A floating sternum is defined as a sternum in which the only attachment to the chest wall is its superior (cranial) border, and in which the body is secured only by the manubrium and whatever lateral and inferior fibrous bands are present. Typically, a floating sternum is caused by either extensive resection of the costal cartilages and perichondrium during correction of pectus excavatum or failure of proper regrowth of these cartilages. Methods: The authors retrospectively assessed the charts of all patients diagnosed with a floating sternum noting age at original correction of pectus excavatum, time from original correction of pectus excavatum to diagnosis of floating sternum, age at correction of floating sternum, complaints before stabilization of the sternum, methods of repair, and postoperative complications. Results: Between July 1993 and June 1999, floating sternum was diagnosed in 7 patients. The mean age of patients who underwent operative correction of a floating sternum was 28.9 years (range, 16 to 42 years). The mean time interval between original correction of pectus excavatum, or "redo," and diagnosis of a floating sternum was 9.9 years (range, 2 to 20 years). Complaints before correction of the floating sternum included sternal pain and instability, exercise intolerance, and difficulty breathing. Operative repair consisted of mobilizing the lateral and inferior edges of the sternum, detaching the fibrous perichondrium, performing anterior sternal osteotomies, and finally supporting the sternum with substernal Adkins struts. All 7 patients had successful stabilization of the sternum. Two of 7 patients underwent 2 procedures to successfully stabilize the sternum. One patient has Adkins struts still in place because of hematopoetic malignancy. Six of 7 patients are now without symptoms. Conclusions: A floating sternum is a morbid phenomenon that may manifest many years after the original procedure. It can cause significant sternal pain, chest wall instability, and respiratory dysfunction, which are the hallmark indications for correction. Repair of a floating sternum can be accomplished successfully. J Pediatr Surg 36:159-164. Copyright © 2001 by W.B. Saunders Company.
Organizational Size, Complexity, and the Administrative Component in Occupational Associations

(1970). Organizational Size, Complexity, and the Administrative Component in Occupational Associations. The Sociological Quarterly: Vol. 11, No. 4, pp. 435-451.
DkkL1 (Soggy), a Dickkopf family member, localizes to the acrosome during mammalian spermatogenesis.

Dickkopf-like 1 (DkkL1) is related to the Dickkopf gene family, a group of proteins that are characterized as secreted antagonists of Wingless (Wnt) signal transduction proteins. DkkL1 mRNA is found in preimplantation mouse embryos and in developing neural tissue, but in adults it is found primarily in the testes. In an effort to elucidate its function, the distribution of DkkL1 protein in mouse testis and mature sperm was analyzed by immunohistochemistry and immuno-blotting techniques. DkkL1 first appeared in the developing spermatocytes in seminiferous tubules as early as Stage XII, coincident with the appearance of DkkL1 mRNA. Surprisingly, however, DkkL1 localized to the developing acrosome in spermatocytes and spermatids and to the acrosome in mature sperm. Furthermore, DkkL1 was N-glycosylated in the testis, but it did not appear to be excreted, and the DkkL1 in mature sperm was no longer N-glycosylated, suggesting that additional post-translational modifications occurred during the final stages of spermatogenesis. These results identify a member of the Dickkopf family as a novel acrosomal protein that may be involved in acrosome assembly or function, a unique role for a secreted signaling molecule.
Relation of Canopy Area and Volume to Production of Three Woody Species

Shrub canopy area, which more closely resembled an ellipse than a circle, shrub volume, and numbers of twigs per plant were highly correlated with weight of current leaves and twigs in aspen (Populus tremuloides), beaked hazel (Corylus cornuta), and pussy willow (Salix discolor). Lower correlations were obtained for shrub height with weight of current leaves and twigs. No appreciable change in correlations was obtained by using logarithmic regressions instead of linear regressions, except for weight versus height. Canopy area of shrub volume—weight relationships may be most applicable where floristics and production studies are combined. See full-text article at JSTOR
Optical studies of IV-VI quantum dots

PbS microcrystallites show strong quantum confinement effects on account of the fact that the particle size is much smaller than the exciton Bohr radius, leading to large blue shifts of the optical absorption edge and the transverse optical phonon frequencies. In addition, femtosecond pump-probe experiments find a transient absorption with tetrahertz oscillatory behavior, due to vibrational quantum beats. The frequency of the tetrahertz response agrees with the fundamental infrared absorption of the PbS microcrystallites, suggesting that the vibrational mode to which the photoexcited carriers couple is a transverse optical phonon.
Alternative power laws for ratio scaling.

To take account of the observed lack of fit of the power law near thresh-old intensities, two different modifications of the power law have been proposed by various investigators. In this paper, both of these two laws are derived as a special case of a generalized power function for ratio scaling. A method is presented for discriminating between the special laws which provides (i) a prescription for the manipulation of independent variables, and (ii) specification of theoretical curves to which empirical curves are to be compared. Maximum-likelihood estimators are derived for the exponents of the special laws under the assumption that the observed subjective ratios are log normal.
Thermomagnetic recording: Physics and materials

Thermomagnetic recording is the production of a remanent magnetization in a material by cooling it from a critical temperature in a small magnetic field. The most prominent applications for thermomagnetic recording presently under consideration are high density information storage and tape copying; other applications, e.g., display and magnetic printing, can also be envisioned. In this review of the field, we discuss the proposed applications of thermomagnetic recording, the physical principles of the various magnetic phenomena that can be used for this purpose, and the degree to which specific materials meet the requirements for thermomagnetic recording.
Changes in production and turnover of surface components labeled with [3H]mannose in amoebae exposed to a general anesthetic

Abstract Amoebae were exposed to the general anesthetic, Althesin, following injection with [ 3 H]mannose, a precursor to cell surface material [17]. The distribution of silver grains over organelles of treated and control cells was studied in electron microscope radioautographs prepared at intervals between 1 and 24 h after the injection of precursor. The normally high incorporation of [ 3 H]mannose into the Golgi apparatus was greatly reduced in anesthetic-treated cells. The rough endoplasmic reticulum of treated amoebae accumulated luminal material, and was maximally labeled much later than in normal cells. Labeling of the cell surface in amoebae exposed to the anesthetic did not attain as high a relative level as controls. In contrast to the peak labeling of the cell surface in controls 12 h after administration of precursor, radioactivity of the surface of treated cells increased throughout the experiment. Labeling of ‘fringed’ vacuoles, believed to be involved in endocytosis, and of ‘polymorphous’ Vacuoles, which are probably a form of lysosome, was also diminished in the presence of anesthetic. The results indicate that glycosylation of glycoproteins, including components of the cell surface, was reduced in the Golgi apparatus. Changes in both morphology and the pattern of labeling suggested that transport of products from the endoplasmic reticulum to the Golgi apparatus was also impaired. The turnover of mannose-containing components of the cell surface appeared to be reduced, perhaps in response to a decline in production by intracellular organelles.
Kinetics of Formation of Vesicles from Lecithin/Sodium Xylenesulfonate Micelles from Stopped-Flow Measurements

The kinetics of vesicle formation from hydrotrope/lecithin micelles in the system of lecithin, sodium xylenesulfonate (SXS), and water were studied via the stopped-flow process in conjunction with light scattering. The essential phases in the system are a micellar (L1) phase and a lamellar liquid-crystalline (LLC) phase. Based upon light scattering and conductance measurements in the L1 phase, the ratio of SXS to lecithin molecules in the micelles was approximately 1. The results of the stopped-flow process showed the mechanism of formation for the vesicles, which lie in equilibrium between the L1 and LLC phases, to be by the agglomeration of fragments.
Poster: Volume Cracker: A bimanual 3D interaction technique for analysis of raw volumetric data

Volume data analysis often involves finding structures inside the volume. Segmentation is the standard method, but it is quite time-consuming. Alternate approaches remove context, assume prior definition of ROI or segments, or distort part of the volume. We propose a new bimanual 3D interaction technique, called Volume Cracker (VC), which allows the user to crack open a volume like a book to analyze the internal structures. VC preserves context by always displaying all the voxels, and by connecting the sub-volumes with curves joining the cracked faces. We discuss the various design choices that we made, based on observations from our prior user studies with volume datasets, inputs from domain scientists, and numerous design studios and brainstorming sessions. We also report the results of a user study comparing VC with a standard desktop interaction technique and a standard 3D bimanual interaction technique. The study used tasks from two categories of a volume analysis task taxonomy that we are designing in consultation with domain scientists. We found VC had significant advantages over the other two techniques for search and pattern recognition tasks.
Aggression in temporal lobe epilepsy and limbic psychotic trigger reaction implicating vagus kindling of hippocampus/amygdala (in sinus abnormalites on MRIs)

Abstract Five aspects associated with potentially aggressive partial limbic seizures are interrelated: (1) Five out of six unselected (consecutively referred) White, male out-of-character aggressive felons (mean age 33) had histories of recurrent nasopharyngeal infections, four with congruent MRIs, two of these MRIs also showed cortical atrophy, three men had histories of various seizures, and one scalp EEG was “congruent with seizures in the temporal regions.” All men had histories of head injuries. The diagnoses of their bizarre acts during a brief psychosis were partial limbic seizures in an “exhibitionist” with temporal lobe epilepsy (TLE) and proposed limbic psychotic trigger reaction (LPTR) in four “murderers”, based on 13 specific symptoms and signs. (2) The men's nasopharyngeal (medical) conditions are hypothesized to be associated with intermittent mild stimulation of the vagus nerve. Supportive evidence shows that (3) experimental vagus stimulation has the most excitatory impact on hippocampus and amygdala, which are also (4) the most susceptible to limbic seizure kindling (by intermittent subthreshold stimuli). (5) even by contrast, high-voltage energy level and frequently applied vagus nerve stimulation (VNS), which is used as an antiepileptic treatment; however, VNS has elicited seizures in some patients.
γ-aminobutyric acid in the central nervous system of metamorphosing and mature Manduca sexta

Abstract We have begun to examine the factors controlling the accumulation of the neurotransmitter γ-aminobutyric acid (GABA) in the central nervous system (CNS) of the sphinx moth Manduca sexta. Analysis of soluble amino acids in CNS structures from mature moths outlines the regional distribution of GABA. Analysis of amino acids in the antennal lobes (the primary olfactory centres) of Manduca during metamorphosis reveals that GABA accumulates gradually and continuously through most of adult development until eclosion; within 18 hr after eclosion, levels of GABA abruptly increase 27–50%. The activity of the biosynthetic enzyme glutamic acid decarboxylase (EC 4.1.1.15), assayed in extracts of antennal lobes from developing moths, does not change after eclosion. Extracts of hemolymph from mature moths contain low levels of glutamate (
Onset of unsteady flow in wavy walled channels at low Reynolds number

Using computational modeling, we examine the development of an unsteady laminar flow of a Newtonian fluid in a channel with sinusoidal walls. The flow is driven by a constant pressure gradient. The simulations reveal two types of unsteady flows occurring in sinusoidal channels. When the amplitude of the wavy walls is relatively small, vortices forming in the channel furrows are shed downstream. For larger wall wave amplitudes, vortices remain inside the furrows and exhibit periodic oscillations and topological changes. We present a phase diagram in terms of wall amplitude and driving pressure gradient separating different flow regimes. Our simulations establish the optimum wall amplitude and period leading to an unsteady flow at the minimum pressure gradient. The results are important for designing laminar heat/mass exchangers utilizing unsteady flows for enhancing transport processes.
Part I: Columns and Blogs: Making Sense of Merging Worlds

ABSTRACT The newspaper and magazine column, key sources for news comment and analysis prior to the Internet, is being challenged by a powerful new contender—the blog. Has the column's importance diminished, even been rendered obsolete, by new e-venues such as the blog? The author, appreciative of the value and history of both columns and blogs, first defines these venues of publication, gives a brief history of each, and then outlines similarities and differences between the two. With this foundation in place, the author then discusses how the boundaries between new modes of online discussion, such as blogs, and traditional modes of journalistic commentary, such as columns, are blurring. The author looks at how blogs are changing professional and academic communication, calling for discussion on how blogs and columns can serve complementary purposes. This paper was the basis for the author's presentation at a panel entitled “Column People: The Future of Columns in a World of Blogs” (with Bob Nardini) at t...
Wage subsidy and full-employment in a dual economy with open unemployment and surplus labor

Abstract This paper deals with an alternative version of a model with open unemployment and surplus labor. When agricultural workers are individual utility maximizers getting average product as wages, a manufacturing wage subsidy may reduce surplus labor while increasing open unemployment; a typical characteristic of lots of developing countries. This paper shows that no subsidy other than an optimum manufacturing wage subsidy can lead the economy toward full-employment.
Loading Drosophila nerve terminals with calcium indicators

Calcium plays many roles in the nervous system but none more impressive than as the trigger for neurotransmitter release, and none more profound than as the messenger essential for the synaptic plasticity that supports learning and memory. To further elucidate the molecular underpinnings of Ca2+-dependent synaptic mechanisms, a model system is required that is both genetically malleable and physiologically accessible. Drosophila melanogaster provides such a model. In this system, genetically-encoded fluorescent indicators are available to detect Ca2+ changes in nerve terminals. However, these indicators have limited sensitivity to Ca2+ and often show a non-linear response. Synthetic fluorescent indicators are better suited for measuring the rapid Ca2+ changes associated with nerve activity. Here we demonstrate a technique for loading dextran-conjugated synthetic Ca2+ indicators into live nerve terminals in Drosophila larvae. Particular emphasis is placed on those aspects of the protocol most critical to the technique's success, such as how to avoid static electricity discharges along the isolated nerves, maintaining the health of the preparation during extended loading periods, and ensuring axon survival by providing Ca2+ to promote sealing of severed axon endings. Low affinity dextran-conjugated Ca2+-indicators, such as fluo-4 and rhod, are available which show a high signal-to-noise ratio while minimally disrupting presynaptic Ca2+ dynamics. Dextran-conjugation helps prevent Ca2+ indicators being sequestered into organelles such as mitochondria. The loading technique can be applied equally to larvae, embryos and adults.
Partial structure, chromosome localization, and expression of the mouse Girk4 gene.

Abstract The G protein-gated potassium channel IKAChconstitutes part of a signaling pathway that mediates the negative chronotropic and inotropic effects of acetylcholine on cardiac physiology. Similar or identical ion channels regulate the excitability of many neurons in response to neurotransmitters. IKAChis composed of two homologous subunits, GIRK1 and GIRK4. Here we describe a partial genomic structure of the mouseGirk4gene. Two exons containing the complete protein-coding sequence were identified.Girk4was mapped to mouse chromosome 9 (13 cM), consistent with the mapping of humanGIRK4to chromosome 11q23–ter. GIRK4 mRNA was found mainly in mouse heart, with trace levels detected in brain, kidney, lung, and spleen. No detectable levels were observed in skeletal muscle, liver, and testis. The onset of GIRK4 mRNA expression in the developing mouse occurs between Embryonic Days 7 and 11, consistent with the appearance and function of the mouse heart.
Predictors of Extradyadic Sexual Involvement in Unmarried Opposite-Sex Relationships

Using a sample of unmarried individuals in opposite-sex romantic relationships that was representative of the United States (N = 933), the current study prospectively evaluated predictors of extradyadic sexual involvement (ESI) over 20 months (from 2007-2010). Data were collected with self-report questionnaires via U.S. mail. Participants were 18 to 35 years old, and 34.9% were male. Variables tested as predictors included involved-partner factors such as demographic characteristics, sexual history, and mental health, as well as relationship-related factors including communication, sexual dynamics, and aspects of commitment. Future ESI was significantly predicted by lower baseline relationship satisfaction, negative communication, aggression, lower dedication, absence of plans to marry, suspicion of partners' ESI, and partners' ESI. It was not predicted by sexual frequency, sexual dissatisfaction, or cohabitation status. Although more problems with alcohol use, more previous sex partners, and having parents who never married one another predicted future ESI, there were many involved-partner demographic factors that did not predict later ESI (e.g., gender, age, education, religiosity, having divorced parents, and having children). None of the results were moderated by gender. These results suggest that compared to demographic characteristics, relationship dynamics and negative interactions are more strongly predictive of future ESI. Implications for future research are discussed.
Leapfrogging, Urban Sprawl, and Growth Management: Phoenix, 1950–2000

Through a case study of Phoenix, Arizona, this paper examines how urban sprawl is linked to opportunities for capital gains. It focuses on “leapfrogging,” in which developers skip over properties to obtain land at a lower price further out despite the existence of utilities and other infrastructure that could serve the bypassed parcels. The paper examines patterns of growth since 1950 and planners' efforts to structure that growth. It discusses two programs that addressed consequences of leapfrogging: development impact fees to help pay for infrastructure costs of new development and an Infill Housing Program to encourage residential development on vacant land. It concludes with a brief discussion of the future of growth management in Phoenix.
Westward-propagating SST Anomaly Features in the Sargasso Sea, 1982–88

Abstract Sea surface temperature (Ts) maps of the region from 59.5° to 75.5°W, 22.5° to 33.5°N containing the western North Atlantic Subtropical Convergence Zone (STCZ) were derived from AVHRR/2 images. The 7- year mean annual cycle was removed and the maps were filtered in space and time to represent anomaly variability with wavelengths ≥ 220 km and periods ≥ 50 days. Warm and cold anomaly features were observed cast of 71°W between 26° and 32°N that propagated westward at 3–4 km day−1 and that occasionally exceeded ±1°C in amplitude. They are generally strong and persistent from fall to spring and are only marginally detectable during summer. During 1981–82, 1982–83, and 1985–86, individual features could be followed through the entire fall-spring interval. During 1983–84,1986–87,and 1987–88,they could typically be followed for 2–4 months, and during 1984–85, for only 1–2 months. The features were anisotropic during all fall-spring intervals except 1986–87, and they had characteristic wavelengths of ∼80...
The lymphatic system in human embryos, with a consideration of the morphology of the system as a whole

In this article Florence Sabin discusses in detail her observations about the development of the lymphatic system, and argues that the lymphatic structures are derived from the veins, not from mesenchyme (the undifferentiated connective tissue in the embryo, from which connective tissues, blood vessels, and other structures develop).
Variables affecting bond strength of resin-bonded bridge cements.

Abstract In vitro tensile bond strengths of an etched Ni-Cr-Be alloy to enamel were measured using 5 two-paste and 2 paste-primer resin cements. Bond strengths of 2 cements tested were 50–60% higher to rough than to smooth enamel. Increasing the film thickness of a paste-primer cement from complete seating to 0.51 mm decreased the bond strength by 73%. Bond strengths of the 7 cements ranged from 7.3 to 12.0 MN/m 2 and all failures occurred at the cement-enamel interface for samples completely seated to rough enamel.
An intraoperative skin-stretching device to close wounds in Mohs defects.

BACKGROUND A skin-stretching device takes advantage of the viscoelastic properties of the skin by exerting incremental traction to aid in dosing complex wounds. OBJECTIVE To evaluate the effectiveness of a skin-stretching device and determine the cosmetic results available when this device is used in Mohs surgery. METHODS We applied a skin-stretching device to seven patients, each of whom had a large, complex wound defect following Mohs surgery. All of the patients had basal cell carcinomas. In one patient the carcinoma was on an upper extremity, and in the others the carcinoma was located on broad facial surfaces, including the temple and forehead. RESULTS Complete primary closure was accomplished in six patients. A maximum of three cycles of tissue stretching were applied during the period of tissue processing between Mohs layers. In one patient the defect was reduced in size by more than 75%, with final healing by secondary intention. In two patients minor complications developed: focal wound dehiscence occurred in one patient and in the second patient, an inconsequential hypertrophic scar developed. In both cases, the problems resolved with acceptable cosmetic results. The remaining patients experienced no complications and the cosmetic results were excellent. CONCLUSION The skin-stretching device accomplishes effective primary closure of large skin defects by dramatically reducing the size of the defect. It allows a simpler closure where a full-thickness graft or local flap would have otherwise been utilized. The device is convenient to use with minimal complications, reduces operative time, and aids greatly in preserving tissue integrity.
Neuropsychological screening in the psychiatric emergency room.

Abstract In a pilot study, a neuropsychological minibattery of tests consisting of Trail-Making Test A (TMA), Trail-Making Test B (TMB), and the Visual Reproduction subtest (VR) of the Wechsler Memory Scale was administered to patients with common psychiatric diagnoses in a psychiatric emergency room (ER). Patients with adjustment disorders were not distinguish-able from normal controls, while patients with affective disorders and schizophrenia were more impaired than both of these samples. It is suggested that this or a similar minibattery of tests can be of use as an adjunct screening device for differential diagnosis of adjustment disorder versus more serious psychopathology in psychiatric ERs.
Potential soil carbon sequestration in a semiarid Mediterranean agroecosystem under climate change: Quantifying management and climate effects

Climate change is projected to significantly impact vegetation and soils of managed ecosystems. In this study we used the ecosystem Century model together with climatic outputs from different atmosphere-ocean general circulation models (AOGCM) to study the effects of climate change and management on soil organic carbon (SOC) dynamics in semiarid Mediterranean conditions and to identify which management practices have the greatest potential to increase SOC in these areas. Five climate scenarios and seven management scenarios were modeled from 2010 to 2100. Differences in SOC sequestration were greater among management systems than among climate change scenarios. Management scenarios under continuous cropping yielded greater C inputs and SOC gain than scenarios under cereal-fallow rotation. The shift from rainfed conditions to irrigation also resulted in an increase of C inputs but a decrease in the SOC sequestered during the 2010-2100 period. The effects of precipitation and temperature change on SOC dynamics were different depending on the management system applied. Consequently, the relative response to climate and management depended on the net result of the influences on C inputs and decomposition. Under climate change, the adoption of certain management practices in semiarid Mediterranean agroecosystems could be critical in maximizing SOC sequestration and thus reducing CO2 concentration in the atmosphere.
Organizational Knowledge Creation in the Chinese Context

This paper elaborates theories of organizational knowledge creation by exploring the implications of institutional change for organizational knowledge creation in Chinese organizations of different ownership forms. Using a dynamic institutional perspective, we discuss prominent characteristics of the Chinese context and develop propositions about knowledge creation patterns in different organizational forms. We also theorize about the effects of increasing institutionalization on patterns of organizational knowledge creation in China and the consequent implications for innovation. We conclude with a discussion of the theoretical implications of this model and suggestions for further research.
Bone mineral density and mass by total-body dual-photon absorptiometry in normal white and asian men

Total body bone mineral density, total body bone mineral mass (TBBM), and bone mineral densities (BMD) in seven different regions of the body were measured in 238 normal men (154 Whites and 84 Asians), age 22-94, using dual-photon absorptiometry. Although Asian men had lower TBBM and BMD in all regions (p less than 0.05) except the arms, when multiple regression was done with body weight, height, and age, no significant differences were found between Asians and Whites for bone measurements. Thus lower bone mineral densities and bone mineral mass in Asian males compared to White males appear to be due to differences in height and weight rather than to ethnic differences. The two groups were combined to derive multiple regression equations for TBBM, total-body BMD, and regional BMD. Age, weight, and height were significant in the multiple regression equations for TBBM, ribs BMD, and legs BMD. Age and weight, but not height, were significant for total-body BMD, trunk BMD, spine BMD, arm BMD, and pelvis BMD. Weight, but neither height nor age, was significant for head BMD. These reference normal bone mineral density and bone mineral mass standards are appropriate for both Asian and White males when adjusted for weight, height, and age.