cssi/SciSciGPT-SciSciNet huggingface dataset:
Optical line narrowing by nuclear spin decoupling in Pr3+: LaF3

Abstract We have applied the technique of nuclear spin decoupling to the optical regime. In these experiments we selectively eliminated the role of 19F spin fluctuations as the dominant source of dephasing in the 5925A (1D2 / 3H4)Pr3+ optical transition in 0.05% Pr3+: LaF3 at 2K. The homogeneous optical linewidth (FWHM), measured by photon echoes, was reduced from 56 kHz to 6 kHz by on-resonance nutation of 19F in an external magnetic field of 375G. Further reduction of the linewidth to 4.1 kHz was observed by off-resonance irradiation of the fluorines such that their effective field in the rotating frame was at the ‘magic angle’ ( cos -1 1 3 ) with respect to the external field.
Neurologic symptoms in licensed private pesticide applicators in the agricultural health study.

Exposure to high levels of many pesticides has both acute and long-term neurologic consequences, but little is known about the neurotoxicity of chronic exposure to moderate levels of pesticides. We analyzed cross-sectional data from 18,782 white male licensed private pesticide applicators enrolled in the Agricultural Health Study in 1993–1997. Applicators provided information on lifetime pesticide use and 23 neurologic symptoms typically associated with pesticide intoxication. An indicator of more symptoms (≥10 vs. 500 days, compared with never users. A modest association for fumigants [> 50 days, 1.50 (1.24–1.81)] and weaker relationships for herbicides [> 500 days, 1.32 (0.99–1.75)] and fungicides [> 50 days, 1.23 (1.00–1.50)] were observed. Pesticide use within the year before enrollment was not associated with symptom count. Only associations with insecticides and fumigants persisted when all four pesticide groups were examined simultaneously. Among chemical classes of insecticides, associations were strongest for organophosphates and organochlorines. Associations with cumulative exposure persisted after excluding individuals who had a history of pesticide poisoning or had experienced an event involving high personal pesticide exposure. These results suggest that self-reported neurologic symptoms are associated with cumulative exposure to moderate levels of fumigants and organophosphate and organochlorine insecticides, regardless of recent exposure or history of poisoning.
The Structure of Empathy in Social Work Practice

This article presents a detailed theoretical framework demonstrating how empathy is used in the practice of social work. This consists of affective, cognitive, and behavioral dimensions of empathy and delineates six latent constructs that make up these dimensions. These constructs are (1) caring, (2) congruence, (3) interpersonal sensitivity, (4) perspective taking, (5) altruism, and (6) the therapeutic relationship. Evolutionary, sociological, and neuroscience theories are used to describe empathy's origins as a historically adaptive and interactional process, and social work theories emphasize empathy as an interpersonal helping strategy and organizing principle essential to the practice of social work.
Perioperative heart-type fatty acid binding protein levels in atrial fibrillation after cardiac surgery

Background Postoperative atrial fibrillation (POAF) is common and associated with poor outcomes. Perioperative ischemia can alter arrhythmic substrate. Objective To demonstrate an association between perioperative measurements of heart-type fatty acid binding protein (HT-FABP), a sensitive marker of ischemic myocardial injury. Methods Blood samples from 63 inpatients undergoing coronary artery bypass surgery, valve surgery, or both were obtained before and up to 4 days after surgery. Continuous telemetry monitoring was used to detect POAF. Fifty-nine patients had at least 3 HT-FABP measurements. The relationship of enzyme-linked immunosorbent assay-measured HT-FABP with POAF was assessed by using joint logistic regression adjusted for age and surgery type. Results Thirty-five patients (55%) developed POAF; these were, on average, older (69.3±10 years vs 60±11 years; P = .0019), with a higher prevalence of heart failure (43% vs 17%; P = .034), chronic obstructive lung disease (26% vs 4%; P = .017), preoperative calcium channel blocker use (29% vs 7%; P = .031), and more likely to undergo combined surgery (21% vs 11%, P = .049). The joint age- and coronary artery bypass surgery-adjusted model revealed that postoperative but not preoperative HT-FABP levels predicted POAF (coefficient 1.9±0.87; P = .03). Longer bypass time, prior infarction, and worse renal function were all associated with higher postoperative HT-FABP . Conclusions A greater rise of HT-FABP is associated with atrial fibrillation after cardiac surgery, suggesting that ischemic myocardial damage is a contributing underlying mechanism. Interventions that decrease perioperative ischemic injury may also decrease the occurrence of POAF.
Psychophysical studies of pigeon color vision--II. The spectral photochromatic interval function.

Abstract A two-choice operant discrimination procedure was used to determine the spectral photochromatic interval function for the red field of the pigeon visual system under light adaptation. The interval is largest at about 600 nm. and falls to very low values at the spectral extremes. The data are consistent with a proposed model of the visual system which assumes that achromatic spectral sensitivity is determined by an additive combination of responses from cones containing a 562-nm pigment (iodopsin) and from cones containing a postulated pigment with a peak absorption at 415 nm: and that chromatic sensitivity arises from opponent interactions between responses from these same cones.
Factors affecting radiologist inconsistency in screening mammography.

Abstract Rationale and Objectives Although research has successfully documented variability in radiologists' interpretation of mammograms, it has failed to determine the relative contributions of case-specific features and reader inconsistency. Training interventions to improve consistency will be ineffectual if they do not target the principal determinants of disagreement among radiologists. The current study assessed the relative contributions of the case and the interpreter to the problem of inconsistent interpretation. Materials and Methods One hundred ten radiologists independently interpreted mammograms from the same 148 screening cases (43% with biopsy-proved cancers) and reported the presence or absence of calcifications, mass, architectural distortion, and asymmetric density in each of 296 breasts. The radiologists were blinded to disease status (established at biopsy or follow-up). Results Case-related differences accounted for a greater proportion of interpretation disagreement than did differences between interpreters. The presence of cancer was associated with increased disagreement, perhaps because of the multiplicity of findings. Patient age was also associated with increased disagreement in the reporting of calcifications. Conclusion For screening mammography, increased consistency between radiologists in their recognition and reporting of clinically important findings will best be achieved by reducing disagreement in difficult cases. Current training in the United States addresses difficult cases only as they have been defined intuitively or experientially. The authors' population-based method provides an objective metric to measure case difficulty and basis from which to identify difficult cases for targeted training.
Psychodynamic aspects of delayed abortion decisions.

Multiple regression analysis of a wide range of variables for a sample of 58 women obtaining elective abortion identified psychodynamic factors as the only statistically significant explanations for seeking abortion at later gestational ages. Delay among these women was associated with greater disturbance in the basic sense of self as noted in indications of gender/sexual conflict on their drawings of a human figure, and lower achievement orientation (‘striving’) as expressed by lower levels of striving attributed to parents or other primary (early) caretakers. These findings are discussed as an active taking charge of an unintended pregnancy for women who present early for abortion; for those who delay, attempts to affirm a deficient feminine identification and/or reunite psychologically with the early caretaker are discussed as underlying dynamics.
Cool Companions to White Dwarfs from the Two Micron All-Sky Survey Second Incremental Data Release

We present near-infrared (IR) magnitudes for all white dwarfs (selected from the catalog of McCook & Sion) contained in the Two Micron All-Sky Survey second incremental data release (2MASS 2IDR). We show that the near-IR color-color diagram is an effective means of identifying candidate binary stars containing a WD and a low-mass, main-sequence star. The loci of single WDs and WD+red dwarf binaries occupy distinct regions of the near-IR color-color diagram. We recovered all known unresolved WD+red dwarf binaries located in the 2IDR sky coverage and also identified as many new candidate binaries (47 new candidates out of 95 total). Using observational near-IR data for WDs and M-L dwarfs, we have compared a sample of simulated WD+red dwarf binaries with our 2MASS data. The colors of the simulated binaries are dominated by the low-mass companion through the late M to early L spectral types. As the spectral type of the companion becomes progressively later, however, the colors of unresolved binaries become progressively bluer. Binaries containing the lowest mass companions will be difficult to distinguish from single WDs solely on the basis of their near-IR colors.
Prolactin stimulates transcription of aspartate aminotransferase in prostate cells.

Abstract Prolactin (PRL) has been reported to stimulate citrate production and the activity of mitochondrial aspartate aminotransferase (mAAT) and its precursor form pmAAT in prostate epithelial cells. The phorbol ester 12- O -tetra-decanoylphorbol 13-acetate (TPA) caused the same result as PRL, which suggests that the PRL effect on mAAT activity might be mediated by protein kinase C (PKC) stimulation of pmAAT gene transcription. Both PRL and TPA increased the level of pmAAT mRNA by 2.5- to 3-fold in pig prostate cells. The PKC inhibitor gossypol completely inhibited the PRL and TPA induced increases. In addition, the effects of both PRL and TPA were inhibited by down-regulation of prostate PKC. Nuclear run-off assays indicated that PRL and TPA induction of pmAAT occurred primarily at the transcriptional level. The stimulation of pmAAT transcription by TPA suggests that the pmAAT gene contains a TPA response element. Thus, these results are consistent with our previous observation that PRL directly induces pmAAT and that the mechanism of this PRL effect might involve stimulation of PKC.
Chamber technology concepts for inertial fusion energy—three recent examples

Abstract The most serious challenges in the design of chambers for inertial fusion energy (IFE) are: (1) protecting the first wall from fusion energy pulses on the order of several hundred megajoules released in the form of X-rays, target debris, and high energy neutrons; and (2) operating the chamber at a pulse repetition rate of 5–10 Hz (i.e. re-establishing the wall protection and chamber conditions needed for beam propagation to the target between pulses). In meeting these challenges, designers have capitalized on the ability to separate the fusion burn physics from the geometry and environment of the fusion chamber. Most recent conceptual designs use gases or flowing liquids inside the chamber. Thin liquid layers of molten salt or metal and low pressure, high-Z gases can protect the first wall from X-rays and target debris, while thick liquid layers have the added benefit of protecting structures from fusion neutrons thereby significantly reducing the radiation damage and activation. The use of thick liquid walls is predicted to: (1) reduce the cost of electricity by avoiding the cost and down time of changing damaged structures; and (2) reduce the cost of development by avoiding the cost of developing a new, low-activation material. Various schemes have been proposed to assure chamber clearing and renewal of the protective features at the required pulse rate. Representative chamber concepts are described, and key technical feasibility issues are identified for each class of chamber. Experimental activities (past, current and proposed) to address these issues and technology research and development needs are discussed.
Parametric adjustment to a shifting target alternating with saccades to a stationary reference point

The oculomotor system can progressively improve the accuracy of repeated saccades to a target that shifts in midsaccade, by utilizing retinal feedback to diminish the induced error. The present study investigated whether this parametric adjustment compromises S’s ability to fixate the stationary reference point on alternating saccades to the other side of his visual field. Fixation of the reference point on shifting-target runs was sometimes even more accurate than fixation on stationary-target runs. The capacity of the parametric adjustment mechanism to adapt to specific targets was thereby demonstrated.
Stereotactic radiosurgery for recurrent central neurocytoma: case report.

OBJECTIVE AND IMPORTANCE: Neurocytomas are typically benign tumors that have high local control rates after gross total resection. Nevertheless, tumor recurrence is possible, and some patients have aggressive tumors. CLINICAL PRESENTATION: A 26-year-old woman had a recurrent, asymptomatic neurocytoma 3 years after gross total resection. INTERVENTION: The patient underwent stereotactic radiosurgery for the tumor recurrence. Thirty-four months later, the patient remained neurologically intact, and the tumor had decreased significantly in size. CONCLUSION: Radiosurgery may be a viable treatment option for patients with recurrent neurocytomas or for patients whose tumor resections were subtotal.
A simple micromethod for rapid kinetic analyses of yeast enzymes in situ

Abstract A simple approach for rapid assay of enzymes in large numbers of samples of whole cells of yeast is described. The technique involves treatment of yeast cells with toluene dissolved in ethanol (1:4, v/v; TE), rendering them selectively permeable to small molecules, while letting the enzymes remain intracellular and catalytically active but accessible to exogenously added assay reagents. The permeated cell preparations permit rapid assay of nitrate reductase activity in situ [ P. V. Choudary and G. Ramananda Rao (1976) Current Sci. 45 , 324–327]. Investigation of enzyme kinetic parameters such as pH optima, temperature dependence, and substrate saturation, which involves several samples and needs to be investigated very rapidly and accurately, is greatly facilitated by permeated cells prepared from a very small culture of cells, eliminating the need for elaborate preparations of cell extracts. By using permeabilized cell preparations, the need to supplement the reaction mixture with expensive cofactors can also be obviated to a large extent. Further, the enzyme activity displays a broader range of tolerance in situ to variations in reaction conditions compared to that in vitro . Permeabilized cell preparations thus seem to present the enzymes in the form of relatively less disintegrated functional complexes, making them a valuable tool in biochemical and cell biological investigations, and facilitate the correlation of in vitro data with the in vivo phenomena more confidently.
American Adults' Knowledge of Exercise Recommendations

Abstract Physical inactivity is a major risk factor for cardiovascular disease, stroke, hypertension, diabetes, obesity, osteoporosis, and some cancers. Approximately 950,000 Americans die annually from cardiovascular diseases. The purpose of this study was to determine whether American adults know which traditional and lifestyle physical activities affect health and how they should be physically active to achieve a health benefit. Secondary purposes were to determine whether this knowledge is a function of gender, ethnicity, education, or age and if those who are sufficiently active for a health benefit possess different knowledge levels than those not sufficiently active for a health benefit. Items based on the Centers for Disease Control and Prevention/American College of Sports Medicine principles included knowledge of exercise guidelines and traditional and lifestyle physical activities. This information was obtained from 20 questions that were part of a national random telephone survey of 2,002 Amer...
Field-theoretical interpretation of the holographic renormalization group

A quantum-field theoretical interpretation is given to the holographic RG equation by relating it to a field-theoretical local RG equation which determines how Weyl invariance is broken in a quantized field theory. Using this approach we determine the relation between the holographic C theorem and the C theorem in two-dimensional quantum field theory which relies on the Zamolodchikov metric. Similarly we discuss how in four dimensions the holographic C function is related to a conjectured field-theoretical C function. The scheme dependence of the holographic RG due to the possible presence of finite local counterterms is discussed in detail, as well as its implications for the holographic C function. We also discuss issues special to the situation when mass deformations are present. Furthermore we suggest that the holographic RG equation may also be obtained from a bulk diffeomorphism which reduces to a Weyl transformation on the boundary.
Strategies for retaining land in agriculture: An analysis of Virginia's agricultural district policy

Abstract As the competition between agricultural and non-agricultural uses of prime land intensifies, land-use policies designed to retain land in agricultural use are gaining wider acceptance at the state and local level. This paper presents an analysis of one farmland retention policy currently in use in the United States: formation of agricultural districts. The formation of agricultural districts, a voluntary policy for retaining land in agriculture, is traditionally thought to be an ineffective strategy for preserving the agricultural land near urban areas. In Virginia however, formation of agricultural districts has been concentrated around the state's growth corridor. After a review of alternative strategies for retaining land in agriculture, this paper focuses on information gained through a land-use survey of 410 Virginia landowners and analysis of their farmland retention policy participation behavior. The empirical results of a logit analysis of policy participation behavior are presented and discussed in terms of characteristics of policy design and implementation that influence participation. Based on conclusions drawn from this study, policy-oriented suggestions are offered for the development of farmland retention strategies which better meet the demands of local land-use decision makers.
Suppression of Gene Expression by Targeted Disruption of Messenger RNA: Available Options and Current Strategies

At least three different approaches may be used for gene targeting including: A) gene knockout by homologous recombination; B) employment of synthetic oligonucleotides capable of hybridizing with DNA or RNA, and C) use of polyamides and other natural DNA-bonding molecules called lexitropsins. Targeting mRNA is attractive because mRNA is more accessible than the corresponding gene. Three basic strategies have emerged for this purpose, the most familiar being to introduce antisense nucleic acids into a cell in the hopes that they will form Watson-Crick base pairs with the targeted gene's mRNA. Duplexed mRNA cannot be translated, and almost certainly initiates processes which lead to its destruction. The antisense nucleic acid can take the form of RNA expressed from a vector which has been transfected into the cell, or take the form of a DNA or RNA oligonucleotide which can be introduced into cells through a variety of means. DNA and RNA oligonucleotides can be modified for stability as well as engineered to contain inherent cleaving activity. It has also been proven that because RNA and DNA are very similar chemical compounds, DNA molecules with enzymatic activity could also be developed. This assumption proved correct and led to the development of a "general-purpose" RNA-cleaving DNA enzyme. The attraction of DNAzymes over ribozymes is that they are very inexpensive to make and that because they are composed of DNA and not RNA, they are inherently more stable than ribozymes. Although mRNA targeting is impeccable in theory, many additional considerations must be taken into account in applying these strategies in living cells including mRNA site selection, drug delivery and intracellular localization of the antisense agent. Nevertheless, the ongoing revolution in cell and molecular biology, combined with advances in the emerging disciplines of genomics and informatics, has made the concept of nontoxic, cancer-specific therapies more viable then ever and continues to drive interest in this field.
The effect of erythropoietin on the growth and development of spleen colony-forming cells

The progressive growth and development of spleen colonies was studied in heavily irradiated host mice in which erythropoiesis was modified by various procedures. Erythropoietic activity in non-polycythemic hosts bearing spleen colonies was not increased by injections of exogenous erythropoietin. Detectable levels of erythropoietin were found in the heavily irradiated host mice suggesting that the failure of exogenous erythropoietin to modify erythropoiesis was because the host mice were already maximally stimulated by the high endogenous erythropoietin levels. Spleen colonies do not become erythroid in polycythemic mice. The injection of exogenous erythropoietin into heavily irradiated polycythemic hosts did not decrease the total number of spleen colonies produced by a given bone marrow transplant, as would be expected if erythropoietin acted directly on the colony-forming cells. Comparison of growth curves for colony-forming cells in the spleens of polycythemic hosts either receiving or not receiving erythropoietin indicated that the overall doubling time of colony-forming cells during the first ten days after transplantation was not changed by the daily injection of erythropoietin. These experiments are consistent with the concept that erythropoietin is necessary for the development of erythroid colonies. Erythropoietin acts upon some progeny of the colony-forming cell rather than the colony-forming cell itself.
Cognitive processes based on a molecular memory mechanism

The reference neuron model of memory is predicted on a molecular mechanism which allows a pattern of neural activity to be controlled by a single (reference) neuron. This control is established through simultaneous activity of a reference neuron and neurons whose activity reflects environmental input. A computer simulation of a system navigating in an environment is used to explore the capabilities provided by memory processing based on the reference neuron. Simple manipulation of the memory structures demonstrates cognition corresponding to very-short-, short-, and long-term memory. >
Design of an enhanced access point to optimize TCP performance in Wi-Fi hotspot networks

In the last years, the number of Wi-Fi hotspots at public venues has undergone a substantial growth, promoting the WLAN technologies as the ubiquitous solution to provide high-speed wireless connectivity in public areas. However, the adoption of a random access CSMA-based paradigm for the 802.11 MAC protocol makes difficult to ensure high throughput and a fair allocation of radio resources in 802.11- based WLANs. In this paper we evaluate extensively via simulations the interaction between the flow control mechanisms implemented at the TCP layer and the contention avoidance techniques used at the 802.11 MAC layer. We conducted our study considering initially M wireless stations performing downloads from the Internet. From our results, we observed that the TCP downlink throughput is not limited by the collision events, but by the inability of the MAC protocol to assign a higher chance of accessing the channel to the base station. We propose a simple and easy to implement modification of the base station's behavior with the purpose of increasing the TCP throughput reducing useless MAC protocol overheads. With our scheme, the base station is allowed to transmit periodically bursts of data frames towards the mobile hosts. We design a resource allocation protocol aimed at maximizing the success probability of the uplink transmissions by dynamically adapting the burst length to the collision probability estimated by the base station. By its design, our scheme is also beneficial to achieve a fairer allocation of the channel bandwidth among the downlink and uplink flows, and among TCP and UDP flows. Simulation results confirm both the improvement in the TCP downlink throughput and the reduction of system unfairness.
Backbone assignment and dynamics of human α-synuclein in viscous 2 M glucose solution.

We present 1HN, 15N, 13Cα, 13Cβ and 13C′ assignments and 15N transverse relaxation rates (R2) of a Parkinson’s disease-related intrinsically disordered protein, α-synuclein, in the presence of 2 M (360 g/l) glucose solution.
Electroplasticity in metals and ceramics

Abstract The influence of an electric field or corresponding current on the plastic deformation of metals and ceramics is reviewed. Regarding metals, the following are considered: (a) the effects of high density electric current pulse on the flow stress at low to intermediate homologous temperatures; and (b) the effects of an external electric field on superplasticity at high temperatures. The major effect of the current pulses was to reduce the thermal component of the flow stress. This resulted from the combined action of an electron wind force, a decrease in the activation enthalpy for plastic deformation and an increase in the pre-exponential, the last making the largest contribution. Besides giving a reduction in the flow stress during superplastic deformation, an external electric field reduced cavitation and grain growth. The influence of the external field appears to be on the migration of vacancies or solute atom-vacancy complexes along grain boundaries to the charged surface. In the case of ceramics, the effects of an internal electric field on the plastic deformation of polycrystalline NaCl at 0.28–0.75TM and on the superplasticity of fine-grained oxides (MgO, Al2O3 and ZrO2) at T>0.5TM are considered. Regarding NaCl, at T≤0.5TM an electric field E≥10 kV cm−1 is needed to enhance dislocation mobility in single crystals. However, a field of only 1 kV cm−1 significantly reduced the flow stress in polycrystals, which is concluded to result from an enhancement of cross slip. At T>0.5TM, there occurred a decrease in the flow stress of polycrystalline NaCl along with a reduction in the rate-controlling diffusion activation energy. Regarding the fine-grained oxides at T>0.5TM, an internal electric field E≤0.3 kV cm−1 gave an appreciable, reversible, reduction in the flow stress by an enhancement of the rate-controlling diffusion process. Limited work suggests that a field may also retard grain growth and cavitation in ceramics.
Role of multiple binding sites in the inhibition of NADH oxidase by piericidin and rotenone

Abstract Scatchard plots indicate that 14C-piericidin A and -rotenone bind at 2 specific sites per mole of NADH dehydrogenase in ETP, but the titer found for complex I or mersalyl-treated ETP more closely approximates 1. The curves for inhibition of NADH oxidase by piericidin and rotenone are sigmoidal; this results from an unequal contribution of the 2 specific sites to the inhibition. An unspecific binding site also contributes to the inhibition in a manner reversed by washing the particles with bovine serum albumin (BSA). In contrast, inhibition of NADH-CoQ reductase activity is due entirely to binding at specific site(s) because BSA does not restore activity.
An Evaluation of Use of Multimedia Case Studies to Improve an Introduction to Information Technology Course

For college graduates to be successful in today's global economy there has been an increasing demand for them to possess business knowledge as well as technical knowledge. To meet the demand, curriculum designers have sought to integrate new technologies, applications, data, and business functions into classrooms so that non-information technology IT majors can realize the benefits of IT. This paper discusses the results of research conducted on the use of multimedia case studies to address the curriculum designers' challenge. The authors have found that students, who are taught using multimedia case studies, perceived a comparatively greater improvement in their higher-order cognitive skills, ease of learning, team working skills, attitude toward information technology, and self-efficacy. This suggests a need for further research into adopting such instructional materials for teaching non-IT majors and for developing other innovative instructional materials.
Mathematical modelling of a "post-Northridge" steel connection

A robust mathematical model to capture the behaviour of an attractive "post-Northridge" type, Partially Restrained (PR) steel connection is proposed. The proposed procedure captures the loading behaviour for this type of connection reasonably well. It is suggested that the unloading and reloading parts of M ? θ curves required for seismic analysis can be theoretically generated by using the Masing Rule. This study confirms some of the important desirable features of the connection. Although it is a PR connection, its initial stiffness is similar to that of bolted, a single web angle with top and seat connection, generally considered to be a Fully Restrained (FR) connection. Thus, a steel frame with the connection studied is not expected to show weakness in satisfying serviceability requirements. Furthermore, the beam develops full plastic moment and the ductility of the connection and its seismic energy dissipation characteristics are expected to be significantly improved.
The capacity of MIMO wireless systems with mutual coupling

MIMO wireless systems employing antenna arrays with close inter-element spacings exhibit a high degree of mutual coupling. In this case, the channel transfer matrix is a function of the matching network employed for transmitting and receiving. Existing capacity expressions are inappropriate, since the maximum mutual information will depend on antenna element loading. This paper develops a new expression for capacity that includes the effect of mutual coupling and antenna matching. Two simple noise models for realistic high-frequency circuits are introduced. Capacity is computed by maximizing the mutual information in these models subject to a new radiated power constraint. Numerical simulations of realistic two-element arrays demonstrate the basic technique.
THE DEVELOPMENT OF PHRASE STRUCTURE RULES

The development of phrase structure (PS) rules is observed from grammars written for ten children of increasing linguistic sophistication. The simplified PS rules described by Rosenbaum (1967) provide the grammatical framework. The results suggest five stages of development, during which subject noun phrases and verb phrases become obligatory, and complements and relative clauses appear.
Pseudotumor cerebri following spontaneous internal jugular vein thrombosis

A 45-year-old man with a history of nasopharyngeal carcinoma with metastasis to the right side of the neck, who was treated with radiotherapy for cure, developed spontaneous left internal jugular vein thrombosis. Within a few days, the patient showed signs of increasing intracranial pressure, and a diagnosis of pseudotumor cerebri secondary internal jugular vein thrombosis was made. A review of the literature revealed no other case of pseudotumor cerebri in association with spontaneous internal jugular vein thrombosis. The etiology, pathogenesis, clinical presentation, and treatment of pseudotumor cerebri is presented.
Progressive loss of desiccation tolerance in germinating pea (Pisum sativum) seeds

Loss of desiccation tolerance during germination has been described in general terms for many orthodox seeds and has been used as a framework to elucidate the mechanisms that confer tolerance to quiescent embryos. A more detailed description of the time course during which desiccation tolerance is lost will allow us to build a more comprehensive picture of the events that contribute to the loss of tolerance. To more thoroughly characterize the loss of desiccation tolerance, we monitored the viability of germinating pea (Pisum sativum L. cv. Alaska) seeds after drying them to a range of moisture contents. Desiccation tolerance is lost in different embryonic tissues at different times during germination. Thus, we looked separately at the effects of drying on radicle and epicotyl survival and on electrolyte leakage from the whole embryonic axis. Using statistical and graphical analysis, we calculated the moisture content at which the population of germinating seeds began to be damaged by dehydration (threshold moisture content, TMC) and at which dehydration damaged the majority of the population (critical moisture content, CMC). CMCs and TMCs differed for each tissue and increased as germination progressed. TMCs appeared at 18 h of imbibition for radicle survival and electrolyte leakage and at 24 h for epicotyl survival. CMCs appeared at 21 h for radicle survival and electrolyte leakage. Among the axis tissues, epicotyls were the least sensitive to dehydration during germination. CMCs for epicotyl survival did not appear until 30 h of imbibition and did not increase to the extent that they did for either radicle survival or electrolyte leakage. Results from these experiments can be used as a framework to correlate the progression of biochemical and anatomical changes to the progressive loss of desiccation tolerance in germinating pea embryos.
Determination of Neurotransmitter Levels in Models of Parkinson’s Disease by HPLC-ECD

Parkinson's disease (PD) is a neurological disorder caused by progressive degeneration of dopaminergic neurons in the nigrostriatal area of the brain. The decrease in dopamine (DA) neurotransmitter levels in the striatum and substantia nigra pars compacta is a neurochemistry hallmark of PD. Therefore, determination of dopamine and its metabolites levels in biological samples provides an important key to understanding the neurochemistry profile of PD. This chapter describes the use of reversed-phase HPLC with electrochemical detection (ECD) for simultaneously measuring monoamine neurotransmitters, including dopamine and its metabolites, norepinephrine as well as serotonin and its metabolite. ECD provides an ultrasensitive measurement, which detects at the picogram level. One run for each sample finishes within 18 min, shows clear chromatographic peaks and a complete separation, and produces excellent precision and reproducibility. Once set up, HPLC-ECD is economic and efficient for analyzing a large number of samples. This method has been broadly used for analyzing a variety of biological samples, such as cerebrospinal fluids, plasma, microdialysis elutes, tissues, and cultured cells. In recent days, it has been reported to be able to detect the dopamine level in a single drosophila head.
Rapid growth rates of chironomids in three habitats of a subtropical blackwater river and their implications for P:B ratios

Growth rates of chironomids from communities characteristic of three major stream habitats were examined at a field laboratory on the 6th-order Ogeechee River in the lower Coastal Plain of Georgia. Artificial systems that simulated environmental conditions of snags, sand, and backwater habitats were used to compare growth rates of members from these different communities. Three or more growth trials were PHI in each system for between 9 and 16 d. The average daily biomass growth rate for individuals across all trials was highest in the snag community (0.50 d-l) followed by the backwater (0.25 d-l) and sand (0.16 d-l). The low rate in sand was attributed primarily to psammophilous taxa, Lopescladius sp. and Rheos~nittia sp. For taxa found in more than one habitat, we did not find significant differences in growth among habitats. Taxon-specific growth rates were linearly and negatively related with the natural logarithm of mass for Corynoneura taris and groups of related taxa within the Tanytarsini and Polyped&0?2 spp. Size-specific growth rates were applied to quantitative field data from summer 1982 to calculate daily productivity of selected chironomids from the sand habitat. Daily biomass turnover (P : B = g) ranged from 0.13 to 0.5 1. The mean growth rate for selected sand taxa (0.3 1) translates into a 6-month P: B ratio (with temperatures >2O”C) of - 57. With the exception of the psammophilous taxa, annual P: B ratios for most taxa in all three habitats approach or exceed 100.
The Design of Manufacturing Systems

The manufacture of products in the modern industrial world requires the combined and coordinated efforts of people, machinery, and equipment. Thus, a manufacturing system can be defined as a combination of humans, machinery and equipment that are bound by a common material and information flow. The materials input to a manufacturing system are raw materials and energy. Information is also input to a manufacturing system, in the form of customer demand for the system’s products. The outputs of a manufacturing system can likewise be divided into materials, such as finished goods and scrap, and information, such as measures of system performance.
The influence of the surface boundary layer on evolutionary models of Jupiter.

A recent theoretical study of the structure and evolution of Jupiter (Graboske et al.,1974b) is based on a three-stage model of Jovian evolution. The central phase, gravitational contraction of an adiabatic, homogeneous convective fluid system, begins early in solar system evolution and lasts for times of the order of 2 × 109 yr. Good agreement with observed radius and luminosity is achieved for a model with a solar mixture composition. The surface boundary layer has a dominant influence on the evolutionary timescale. Surface boundary factors which are important are the solar energy input, a function of the solar luminosity and the planetary albedo, and the detailed physics of the superadiabatic zone, which depends on the variation of opacity and ∇ad with depth. The evolutionary study demonstrates that the current planet cannot be an adiabatic homogeneous fluid throughout. The inclusion of a superadiabatic zone is necessary, and the existence of a heterogeneous (gravitationally layered) fluid interior is possible.
Native Historical Traditions of Nuclear America and the Problem of Their Archeological Correlation

ica and the relevant local archeological sequences, with emphasis on certain basic methodological considerations of general application; (2) a brief review and critique of some of the leading correlation schemes which have been advanced by various area specialists; and (3) some suggestions for a more systematic procedure of inquiry in this general problem area. It should be regarded as essentially a preliminary methodological analysis; no attempt will be made to offer substitute regional schemes. I hope to follow up this preliminary analysis in the future with some positive working hypotheses.
On the Grammar of Silence: The Structure of My Undocumented Immigrant Writer's Block

In this reflective essay, Alberto Ledesma explores how being undocumented can produce a particular form of writer's block. He argues that there is a pattern of predictable silences and obfuscations...
Cerebral glycolysis: a century of persistent misunderstanding and misconception.

Since its discovery in 1780, lactate (lactic acid) has being blamed for almost any illness outcome in which its levels were elevated. Beginning in the mid 1980s, studies, both on muscle and brain tissues, have suggested that lactate plays a role in bioenergetics. However, great skepticism and, at times outright antagonism was exhibited by many to any perceived role of this monocarboxylate in energy metabolism. The present review attempts to trace the negative attitudes about lactate to the first four or five decades of research on carbohydrate metabolism and its dogma by which lactate is a useless anaerobic end-product of glycolysis. The main thrust here is the review of dozens of scientific publications, many by the leading scientists of their times, through the first half of the 20th century. Consequently, it is concluded that there exists a barrier, described by Howard Margolis as “habit of mind,” that many scientists find impossible to cross. The term suggests “entrenched responses that ordinarily occur without conscious attention and that, even if noticed, are hard to change.” Habit of mind has undoubtedly played a major role in the above mentioned negative attitudes toward this lactate. As early as the 1920s, scientists investigating brain carbohydrate metabolism had discovered that lactate can be oxidized by brain tissue preparations, yet their own habit of mind redirected them to believe that such an oxidation is simply a disposal mechanism of this “poisonous” compound. The last section of the review invites the reader to consider a postulated alternative glycolytic pathway in cerebral and, possibly, in most other tissues, where no distinction is being made between aerobic and anaerobic glycolysis; lactate is always the glycolytic end product. Aerobically, lactate is readily shuttled and transported into the mitochondrion, is converted to pyruvate via a mitochondrial lactate dehydrogenase (mLDH) and then entered the tricarboxylic acid (TCA) cycle.
Gene Expression Analysis Reveals Chemical-Specific Profiles

The articles highlighted in this issue are "Gene Expression Analysis Reveals Chemical-Specific Profiles" by Hisham K. Hamadeh, Pierre R. Bushel, Supriya Jayadev, Karla Martin, Olimpia DiSorbo, Stella Sieber, Lee Bennett, Raymond Tennant, Raymond Stoll, J. Carl Barrett, Kerry Blanchard, Richard S. Paules, and Cynthia A. Afshari (pp. 219-231) and "Prediction of Compound Signature Using High Density Gene Expression Profiling" by Hisham K. Hamadeh, Pierre R. Bushel, Supriya Jayadev, Olimpia DiSorbo, Leping Li, Raymond Tennant, Raymond Stoll, J. Carl Barrett, Richard S. Paules, Kerry Blanchard, and Cynthia A. Afshari (pp. 232-240).
Ethnicity, Race, and Nationalism

This article traces the contours of a comparative, global, cross-disciplinary, and multiparadigmatic field that construes ethnicity, race, and nationhood as a single integrated family of forms of cultural understanding, social organization, and political contestation. It then reviews a set of diverse yet related efforts to study the way ethnicity, race, and nation work in social, cultural, and political life without treating ethnic groups, races, or nations as substantial entities, or even taking such groups as units of analysis at all.
Larval Surveys Indicate Low Levels of Endangered Pallid Sturgeon Reproduction in the Middle Mississippi River

Abstract The pallid sturgeon Scaphirhynchus albus is an endangered riverine species that is less abundant than the sympatric shovelnose sturgeon S. platorynchus with which it hybridizes. The two species are morphologically similar, and due to morphological variation within species, allometry, and the occurrence of morphological intermediates, morphological identification of specimens can be problematic. When the pallid sturgeon was listed under the U.S. Endangered Species Act in 1990, perceived threats included habitat loss due to habitat alteration (dams and channelization), hybridization, and commercial harvest. Previous studies estimated the ratio of adult pallid sturgeon to adult shovelnose sturgeon to be approximately 1:77 in the middle Mississippi River (MMR; the reach between the Missouri River confluence and the Ohio River confluence). One study using morphological identification estimated that 8–26% of Scaphirhynchus larvae collected in the MMR during May and June were pallid sturgeon. Given that...
Transgenic Mice Overexpressing Neuregulin-1 Model Neurofibroma-Malignant Peripheral Nerve Sheath Tumor Progression and Implicate Specific Chromosomal Copy Number Variations in Tumorigenesis

Patients with neurofibromatosis type 1 (NF1) develop benign plexiform neurofibromas that frequently progress to become malignant peripheral nerve sheath tumors (MPNSTs). A genetically engineered mouse model that accurately models plexiform neurofibroma–MPNST progression in humans would facilitate identification of somatic mutations driving this process. We previously reported that transgenic mice overexpressing the growth factor neuregulin-1 in Schwann cells (P 0 -GGFβ3 mice) develop MPNSTs. To determine whether P 0 -GGFβ3 mice accurately model human neurofibroma–MPNST progression, cohorts of these animals were monitored through death and were necropsied; 94% developed multiple neurofibromas, with 70% carrying smaller numbers of MPNSTs. Nascent MPNSTs were identified within neurofibromas, suggesting that these sarcomas arise from neurofibromas. Although neurofibromin expression was maintained, P 0 -GGFβ3 MPNSTs exhibited Ras hyperactivation, as in human NF1-associated MPNSTs. P 0 -GGFβ3 MPNSTs also exhibited abnormalities in the p16 INK4A –cyclin D/CDK4–Rb and p19 ARF –Mdm–p53 pathways, analogous to their human counterparts. Array comparative genomic hybridization (CGH) demonstrated reproducible chromosomal alterations in P 0 -GGFβ3 MPNST cells (including universal chromosome 11 gains) and focal gains and losses affecting 39 neoplasia-associated genes (including Pten , Tpd52 , Myc , Gli1 , Xiap , and Bbc3/PUMA ). Array comparative genomic hybridization also identified recurrent focal copy number variations affecting genes not previously linked to neurofibroma or MPNST pathogenesis. We conclude that P 0 -GGFβ3 mice represent a robust model of neurofibroma-MPNST progression useful for identifying novel genes driving neurofibroma and MPNST pathogenesis.
Diamond heteroepitaxy: pattern formation and mechanisms

Pattern formation that occurs during the initial condensation of diamond can provide insights into the physical mechanisms responsible for crystal growth. From a practical perspective, it can be exploited to develop reliable heteroepitaxial growth processes. Using (001) Ir on sapphire (α-Al 2 O 3 ) or strontium titanate (SrTiO 3 ) as substrate, and a methane-hydrogen plasma in the presence of d.c. bias, we reproducibly generate dense arrays, 10 12 cm -2 , of orientationally-ordered (001) diamond nanocrystallites. They appear on the Ir substrate after the rapid quench brought about by abrupt bias termination. The crystallite sizes are highly monodisperse, with typical lateral size below 10 nm. Under the appropriate conditions, the nascent diamond crystals self-organize into a lattice with six-fold coordination and correlation lengths of several lattice parameters. The regularity of the patterns raises the possibility of a collective instability of the excited carbon condensate. Since the crystallite density is so high, subsequent growth leads to rapid coalescence within a few minutes, resulting in a smooth, continuous film that covers the substrate. When the growth step is extended in time, thick single crystal plates have been grown over areas approaching 1 cm 2 . Particular emphasis is placed on the time evolution of emergent patterns during the bias stage, early coarsening of diamond grains, and the textures during extended growth. These results are placed in the context of dynamical systems driven far from equilibrium.