cssi/SciSciGPT-SciSciNet huggingface dataset:
Mapping Alzheimer's disease progression in 1309 MRI scans: Power estimates for different inter-scan intervals

Neuroimaging centers and pharmaceutical companies are working together to evaluate treatments that might slow the progression of Alzheimer’s disease (AD), a common but devastating late-life neuropathology. Recently, automated brain mapping methods, such as tensor-based morphometry (TBM) of structural MRI, have outperformed cognitive measures in their precision and power to track disease progression, greatly reducing sample size estimates for drug trials. In the largest TBM study to date, we studied how sample size estimates for tracking structural brain changes depend on the time interval between the scans (6–24 months). We analyzed 1309 brain scans from 91 probable AD patients (age at baseline: 75.4±7.5 years) and 189 individuals with mild cognitive impairment (MCI; 74.6±7.1 years), scanned at baseline, 6, 12, 18, and 24 months. Statistical maps revealed 3D patterns of brain atrophy at each follow-up scan relative to the baseline; numerical summaries were used to quantify temporal lobe atrophy within a statistically-defined region-of-interest. Power analyses revealed superior sample size estimates over traditional clinical measures. Only 80, 46, and 39 AD patients were required for a hypothetical clinical trial, at 6, 12, and 24 months respectively, to detect a 25% reduction in average change using a two-sided test (α=0.05, power=80%). Correspondingly, 106, 79, and 67 subjects were needed for an equivalent MCI trial aiming for earlier intervention. A 24-month trial provides most power, except when patient attrition exceeds 15–16%/year, in which case a 12-month trial is optimal. These statistics may facilitate clinical trial design using voxel-based brain mapping methods such as TBM.
The influence of initial outlines on manual segmentation.

Purpose: Initial outlines are often presented as an aid to reduce the time-cost associated with manual segmentation and measurement of structures in medical images. This study evaluated the influence of initial outlines on manual segmentation intraobserver and interobserver precision. Methods: Three observers independently outlined all pleural mesothelioma tumors present in five computed tomography (CT) sections in each of 30 patient scans. After a lapse of time, each observer was presented with the same series of CT sections with the outlines of each observer superimposed as initial outlines. Each observer created altered outlines by altering the initial outlines to reflect their perception of the tumor boundary. Altered outlines were compared to original outlines using the Jaccard similarity coefficient (J). Intraobserver and interobserver precision of observer outlines were calculated by applying linear mixed effects analysis of variance models to the J values. The percent of minor alterations (alterations that resulted in only slight changes in the initial outline) was also recorded. Results: The average J value between pairs of observer original outlines was 0.371. The average J value between pairs of observer outlines when altered from an identical initial outline was 0.796, indicating increased interobserver precision. The average difference between J values of an observer’s segmentation created by altering their own initial outline and when altering a different observer’s initial outline was 0.476, indicating initial outlines strongly influence intraobserver precision. Observers made minor alterations on 74.5% of initial outlines with which they were presented. Conclusions: Intraobserver and interobserver precision were strongly dependent on the initial outline. These effects are likely due to the tendency of observers to make only minor corrections to initial outlines. This finding could impact observer study design, tumor growth assessment, computer-aided diagnosis system validation, and radiation therapy target volume definition when initial outlines are used as an observer aid.
Fossil Tachyine Beetles from Mexican and Baltic Amber

Two new species and one new genus are described and placed within the Tribe Tachyini. A discussion of hypothetical relationships is given for these species. And, a synonymy among names applied to extant groups of tachyines is pointed out and corrected.
A utility-production model of union behavior

This paper expands the scope of the economic analysis of unions by presenting a model that is unusually general with regard to both union leadership objectives and the constraints placed on their behavior and by applying this model to a wide-ranging set of political and economic issues regarding unions. The model assumes that union leadership maximizes an objective function containing both political and economic goals and is constrained by the membership and the firm, as well as by a set of technological constraints. The latter constraints are based on the assumption that union power can be modeled as a partially exogenous production process. After defining the Lagrangian and first-order conditions, the model is compared to previous models of leadership objectives and applied to the analysis of union wage concessions and internal union democracy.
The Use of Unfiltered Light in Determining Particle Radius by the Polarization Ratio of the Scattered Light

The light scattering technique of determining the radius of small spherical particles by measurement of the polarization ratio is extended to the case of nonmonochromatic light. The new method is applied to sulfur and dibutyl phthallate aerosols irradiated by an unfiltered beam from a mercury vapor lamp. The radii obtained with the unfiltered light are in agreement with those obtained when monochromatic light is used.
All-optical fluorescence image recovery using modulated stimulated emission depletion

Fluorescence modulation for selective recovery of desired fluorescence signals has to date required careful fluorophore selection combined with repeated optical recovery from long-lived photoinduced dark states. Adapting an all-optical scheme, modulated stimulated emission depletion (STED) generalizes such modulation schemes by eliminating the need for dark state residence by directly optically depopulating the emissive state at any externally applied frequency. Using two overlapped Gaussian laser spots with the depletion beam being intensity-modulated, fluorescence modulation is readily achieved with a depletion ratio governed by the intensity of the depleting laser. Selective image recovery of otherwise unmodulatable fluorophore signals is directly achieved through this all-optical modulation, and common STED-degrading multiphoton-excited background is readily discriminated against. Both beads and dyes in solution, as well as fluorophores bound within fixed cells are readily imaged in this manner.
On the consistency of CERES longwave flux and AIRS temperature and humidity profiles

[1] In this paper, the temperature and humidity profiles from the Atmospheric Infrared Sounder (AIRS) are evaluated with outgoing longwave radiation (OLR) from the Clouds and the Earth's Radiant Energy System (CERES) measurements. Using collocated CERES and AIRS measurements from A-train observations, the temperature and humidity profiles from the AIRS are evaluated by using them in a radiative transfer model and comparing the modeled OLR with that from the CERES. Both the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) measurements are used to ensure a strict clear-sky condition over the CERES fields-of-view (FOVs) in the evaluation. The paper shows that model-computed OLRs using the AIRS temperature and humidity profiles and surface skin temperature agree well with CERES data for daytime oceans, indicating good accuracies of both the AIRS and the CERES products. However, it is found that a certain discrepancy exists between OLR from the modeling with the AIRS atmospheric profiles and that from the CERES measurements. For nighttime oceans, the AIRS temperature and humidity profiles and surface skin temperature likely have significant bias errors in tropical and subtropical areas that are due to undetected thin cirrus clouds. The inconsistency of the CERES and the AIRS product in OLR needs to be understood for reliable earth radiation studies.
Quality of Graduate Productivity in Sociology as Measured by the Citation Index: A Longitudinal Overview.

The discipline of sociology generally has not analyzed the differential productivity among graduates of doctoral programs. When such productivity has been assessed, quantity rather than quality of publications has been the basis for comparisons. The present study uses data compiled from the Social Science Citation Index to measure the differential contributions to sociology by the graduates of a number of long established and prestigious doctoral programs in the field. Based on these data, a number of interesting patterns emerge concerning the quality of graduates' productivity, both across departments and within various alumni cohorts of the same department.
Some Atomic Effects of an Electronic Electric Dipole Moment

A parity-violating perturbation, corresponding physically to a permanent electric dipole moment of an electron parallel to its spin, is introduced into the Dirac equation for an electron. For positrons two choices of the relative sign of electric moment and spin are considered. Some numerical consequences of such a perturbation for hydrogenic atoms and for positronium are calculated.From various experiments carried out previously, rough upper limits are obtained for $\ensuremath{\xi}$, the electric dipole moment expressed in units of $\frac{e\ensuremath{\hbar}}{\mathrm{mc}}$: From the numerical value of the Lamb shift, $\ensuremath{\xi}l0.004$; from the metastability of the $2s$-state in hydrogen, $\ensuremath{\xi}l0.03$. From the absence of $K\ensuremath{\rightarrow}{L}_{\mathrm{I}}$ x-ray transitions in the heaviest atoms, the upper limit for $\ensuremath{\xi}$ is about 0.005 or, probably, even smaller. From the value of the hyperfine splitting of the positronium ground state, $\ensuremath{\xi}l0.02$.
Complex biological responses to the experimental acidification of Little Rock Lake, Wisconsin, USA

Abstract Acidification can affect aquatic organisms directly through hydrogen ion toxicity, and indirectly through disrupted food web dynamics and altered abiotic conditions. Field populations from selected taxa were studied during the Little Rock Lake whole-basin acidification experiment to illustrate patterns whose timing suggests direct (i.e. immediate) or indirect (i.e. delayed or non-uniform) responses to pH change. As the treatment basin was acidified to pH 5·6, 5·2 and 4·7, immediate changes consistent with a direct pH response were observed for species representing several trophic levels. For other taxa (e.g. littoral invertebrates associated with filamentous algal mats, several species of pelagic zooplankton), indirect mechanisms induced by food web changes were more likely explanations for abundance patterns. The results presented here suggest that the responses of aquatic ecosystems to acidification involve a complex interplay between direct pH effects and subsequent indirect interactions.
Suicide and Educational Attainment in a Transitional Society

The sociological evidence available to date has not firmly established the relationship between suicide and social status. It is postulated here that societies in different stages of development ma...
A rational method for relating as-built quality to pavement performance and value

Highway construction specifications routinely use adjusted-payment provisions to award payment in proportion to the level of quality received. Work that meets the level of quality defined as acceptable is eligible for 100 percent payment, whereas work that fails to meet the desired quality level but that is not sufficiently deficient to warrant removal and replacement typically receives some degree of pay reduction. More recently, many agencies have begun to offer monetary incentives in the form of bonus provisions for work that substantially exceeds the desired level of quality. Although the pay-adjustment approach to highway quality assurance is now widely used, there is not yet a consistency of practice regarding the magnitude of pay adjustment judged appropriate for varying levels of as-built quality. To achieve consistency and make this approach more effective and defensible, there is need for a method to relate as-built quality to expected performance, which can then be related to value by engineeri...
Molecular engineering towards safer lithium-ion batteries: a highly stable and compatible redox shuttle for overcharge protection

Overcharge abuse is one of the most common and dangerous safety issues with state-of-the-art lithium-ion batteries. Thus, incorporation of overcharge prevention into the lithium-ion battery pack is key to its practical application. Redox shuttle molecules that can be reversibly oxidized and reduced at specific potentials (redox potential) provide an effective and economic method to prevent overcharge abuse for lithium-ion batteries. We have developed a novel oligo(ethylene glycol)-functionalized redox shuttle, 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene (DBBB), that is not only capable of providing efficient and long-lasting overcharge protection to lithium-ion batteries (capable of withstanding over 180 cycles of 100% overcharge at the C/2 rate), but is also compatible with the state-of-the-art lithium-ion cell system. Density functional theory calculations provided an understanding of the stability properties of this new redox shuttle.
The effect of specimen geometry on the tensile strength of graphite

Abstract An investigation of the effect of specimen geometry on the tensile strengths of two nuclear graphites using seven different tensile specimen shapes has been conducted. The design of some samples gave rise to stress concentrations where the fillet met the gage section. Evidence has been obtained that geometry effects can reduce the apparent tensile strength of graphite by as much as 34%. The most satisfactory designs, determined by reference to the strength, were the streamline fillet and the straight, cylindrical sample. A simple method of fastening the straight, cylindrical samples to a steel grip using an epoxy resin has been tested and proven satisfactory.
A Computational Intelligence Approach to System-of-Systems Architecting Incorporating Multi-Objective Optimization

Abstract A computational intelligence approach to system-of-systems architecting is developed using multi-objective optimization. Such an approach yields a set of optimal solutions (the Pareto set) which has both advantages and disadvantages. The primary benefit is that a set of solutions provides a picture of the optimal solution space that a single solution cannot. The primary difficulty is making use of a potentially infinite set of solutions. Therefore, a significant part of this approach is the development of a method to model the solution set with a finite number of points allowing the architect to intelligently choose a subset of optimal solutions based on criteria outside of the given objectives. The approach developed incorporates a meta-architecture, multi-objective genetic algorithm, and a corner search to identify points useful for modeling the solution space. This approach is then applied to a network centric warfare problem seeking the optimum selection of twenty systems. Finally, using the same problem, it is compared to a hybrid approach using single-objective optimization with a fuzzy logic assessor to demonstrate the advantage of multi-objective optimization.
Characterizing complex chemosensors: information-theoretic analysis of olfactory systems

Abstract The mechanisms that underlie a wine lover's ability to identify a favorite vintage and a dog's ability to track the scent of a lost child are still deep mysteries. Our understanding of these olfactory phenomena is confounded by the difficulty encountered when attempting to identify the parameters that define odor stimuli, by the broad tuning and variability of neurons in the olfactory pathway, and by the distributed nature of olfactory encoding. These issues pertain to both biological systems and to newly developed ‘artificial noses' that seek to mimic these natural processes. Information theory, which quantifies explicitly the extent to which the state of one system (for example, the universe of all odors) relates to the state of another (for example, the responses of an odor-sensing device), can serve as a basis for analysing both natural and engineered odor sensors. This analytical approach can be used to explore the problems of defining stimulus dimensions, assessing strategies of neuronal processing, and examining the properties of biological systems that emerge from interactions among their complex components. It can also serve to optimize the design of artificial olfactory devices for a variety of applications, which include process control, medical diagnostics and the detection of explosives.
Extraskeletal and Skeletal Myxoid Chondrosarcoma: A Multiparameter Analysis of Three Cases Including Cytogenetic Analysis and Fluorescence In Situ Hybridization.

Background: Myxoid chondrosarcoma (MCS) is a rare, low-grade, indolent tumor that can occur in soft tissue and bone. It is, however, capable of distant metastases. Previous cytogenetic data include a translocation, t(9;22)(q22-31;q12), occurring in 6 of 14 cases of the extraskeletal variant of the disease. Recently, rearrangement of the EWS gene has been reported in MCS. Methods and Results: Three cases of MCS, two skeletal and one extraskeletal, were examined to identify primary cytogenetic changes and correlate these with immunohistochemical, ultrastructural, and flow-cytometric analysis. The extraskeletal variant of MCS revealed a clonal translocation, t(9;22)(q22;q12), and trisomy for chromosomes 5, 7, 8, 12, 18, and 19. Our two cases of skeletal MCS showed complex karyotypes. In one skeletal tumor, a cryptic translocation involving chromosome 6p21.3 was identified by fluorescence in situ hybridization analysis, using chromosome-specific libraries. Conclusions: Thus far, 50% of cases of extraskeletal MCS, including our cases, have demonstrated a specific translocation, t(9;22)(q22-31;q12). Identifying this translocation is useful in confirming the diagnosis of MCS. Additional cytogenetic and molecular analysis is useful for detecting this translocation, and is also essential to determine other regions of possible diagnostic importance, such as the 6p21.3 breakpoint demonstrated in the present study. These techniques may be most useful for the skeletal lesions, in light of their heterogeneous cell populations and karyotypic variability.
Three-dimensional cranking at finite temperature.

The rotation of hot triaxial nuclei is studied with the {ital i}{sub 13/2} model. A single {ital j}=13/2 shell in the presence of a triaxial quadrupole potential is rotated in three dimensions and at finite-temperature to calculate statistical fluctuations in the orientation of the intrinsic nuclear shape relative to the rotation axis. Calculations are performed with the cranking model under two alternative constraints: (i) the rotational frequency is held constant as the rotation axis is varied, and (ii) the average spin is held constant as the rotation axis is varied. The thermal dependence of the orientation probability distribution is studied for each constraint. The existence of ``tilted`` yrast state solutions is demonstrated at zero-temperature for even particle number. These solutions correspond to stable uniform rotation about an axis that lies in a principal plane of the quadrupole potential. The possibility of observing stable tilted solutions in the extended Landau theory of hot rotating nuclei is discussed.
Both BRAF V600E mutation and older age (≥ 65 years) are associated with recurrent papillary thyroid cancer.

Purpose This study was designed to examine the aggressive features of BRAF-positive papillary thyroid cancer (PTC) and association with age.
The Role of Developmental Histories in the Screening and Diagnosis of Autism Spectrum Disorders

The incidence of diagnosed cases of autism spectrum disorder (ASD) has increased dramatically over the past decade. This may indicate a larger population of individuals with ASD, and may also be the result of better diagnostic definitions and procedures. Early accurate diagnosis is particularly important for children with ASD because of the documented benefits of early educational interventions. One very important component of an ASD screening and diagnostic process is a developmental history. Not only can this type of information assist with diagnosis, but the process of interviewing parents and primary caretakers can provide opportunities for establishing a working alliance with the family, inform further assessment decisions, and facilitate treatment and intervention for coexisting and comorbid disorders. Both structured and semi-structured formats are available for obtaining developmental histories. Personnel who are assigned to obtain developmental histories need strong interviewing skills and extens...
Mre11: roles in DNA repair beyond homologous recombination

The Mre11 protein has well-documented functions in the repair of DNA double-strand breaks via homologous recombination. Now, several new studies reveal that Mre11 also has a role in mammalian DNA double-strand break repair by nonhomologous end joining.
Epidermal growth factor excretion and receptor binding in diabetic rats

Urinary epidermal growth factor (EGF) excretion was calculated as ng EGF per mg creatinine and ng EGF per 24 hr. It was increased 4-9 fold in rats with genetic (BB) or streptozotocin-induced diabetes. It decreased to 2-3 fold control values in insulin-treated animals. In contrast, EGF concentration in serum was lower in diabetic than in control rats (360 +/- 72 vs 524 +/- 150 pg/ml, P .086); EGF level in plasma was unchanged (319 +/- 67 vs 313 +/- 96 pg/ml). In diabetic rats EGF content was increased in submaxillary glands (1018 +/- 259 vs 738 +/- 122 pg/mg protein, P .060) but unchanged in the kidneys (70 +/- 18 vs 65 +/- 6 pg/mg protein in controls). EGF binding to the liver microsomes in diabetic rats was decreased by 30-40% and was not restored by insulin therapy. Binding to the kidneys also showed a tendency to decrease in diabetic animals. The EGF excretion and receptor binding were normal in obese normoglycemic Zucker fa/fa rats. We suggest that hyperglycemia and/or glucosuria may affect EGF synthesis and/or excretion in the kidneys and EGF synthesis or accumulation in the megakaryocytes. The mechanism of decreased EGF receptor binding remains to be clarified.
Neutralization of hyperthermal Ne+ on metal surfaces

Abstract Relative ion yields of low energy (320 eV) Ne+ ions scattered off a number of elemental surfaces are compared. Ion survival probabilities are seen to change significantly from one element to another depending on the surface work function, suggesting that resonant charge exchange between the metal conduction band and Ne 3s atomic level may be just as important as Auger neutralization processes. The observed yield dependence on work function is qualitatively explained using a description of resonant neutralization (RN) based on the Anderson model of an atomic level near a surface. Auger processes are found to be important in determining the final charge state of outgoing ions, while quasi-resonant interactions between the core atomic levels are seen to be nonexistent.
Body Dissatisfaction and Patterns of Media Use Among Preadolescent Children

This study examined school-age children's satisfaction/dissatisfaction with their body sizes and their media consumption and image perception patterns. A sample of preadolescent children at the ages between 8 and 11 (N = 50) was recruited for in-depth individual interviews from a university-sponsored child care facility in a mid-Atlantic state. Results suggested that boys and girls were significantly different in their ideal body preferences. Similar to the results from previous studies on young adults and older teens, preadolescent boys desired to have a heavier body size, whereas girls desired to be thinner than their perceived actual body size. For the pattern of media use, boys showed a greater attraction toward and recall of muscular appearances and athletic ability in all media venues, whereas girls' responses indicated a greater proclivity toward beauty and looks. Results suggest a need to address the development and maintenance of healthy body images among children.
Triode amplifiers for the infrared

Recent progress with diodes operating at infrared wavelengths Suggests the possibility of triode amplifiers for this frequency range. The potential of such devices is considered theoretically; An analysis based on a specific model device is carried out. The results indicate that power gain greater than unity is possible at \lambda = 10\mu . Although the model device is difficult to construct, it is an assemblage of components which are today individually within the state of the art. Infrared triode oscillators appear also to be possible.
Acrylic ampholytic ionomers

Abstract In a continuing study of the preparation of ampholytic ionomers from the polymerization of ion-pair comonomers (cationic-anionic monomer pairs) with nonionic comonomers, the preparation of such ionomers from methyl methacrylate and n-butyl acrylate is described. For both systems, ionomers of varying ion contents were obtained. In the n-butyl acrylate system, a linear relationship of Tq vs. mol % ion content was found, but this did not occur for the methyl methacrylate ionomers. The solubilities of these materials in a wide variety of solvents is discussed. It appears that for n-butyl acrylate ionomers of high ion content in aqueous solution, a new form of polymeric surfactant is obtained.
Allelopathy of Sorghum on Wheat under Several Tillage Systems

Allelopathy by grain sorghum [Sorghum bicolor (L.) Moench] frequently harms wheat (Triticum aestivum L.) when the crops are grown in rotation. Responses of seven wheat cultivars to different methods of tilling sorghum stover were investigated to determine if the problem might be remedied by genetic resistance or improved management of the stover. Field trials on Kahola silt loam soil (fine-silty, mixed mesic Cumulic Hapludolls) compared effects of fallow, tilled sorghum stover, and no-till sorghum stover during the first season and the same treatments plus no-till millet [Pennisetum glaucum (L.) R. Br.] stover the second season. The seven wheat cultivars were planted after the sorghum and millet were harvested and tilled, and their emergence, stand density, and yield components were measured. Tilled sorghum residue often delayed development of the following wheat crop but did not affect grain yields, probably because allelopathic compounds degraded in the soil. No-till sorghum stover had little effect on stand establishment but frequently reduced grain yields of wheat, possibly because allelopathic compounds leached slowly. Wheat grain yields (means of all seven cultivars) were 3.3, 2.8, and 2.3 Mg/ha in fallow, tilled sorghum residue, and no-till sorghum residue, respectively, during 2 yr and 3.1 Mg/ha in no-till millet residue in the second year. Selection of resistant wheat cultivars is probably impractical, because differences were small and inconsistent. However, if erosion of soil is not a concern, allelopathy might be reduced by prompt tillage and other practices that promote rapid decomposition of sorghum stover.
Accumulation, release and retention of petroleum hydrocarbons by the oyster Crassostrea virginica

Two Crassostrea virginica populations, differing in fat content, were experimentally exposed to a complex petroleum-hydrocarbon fraction. The hydrocarbons in this mixture were accumulated by both groups of oysters, and their lipid content, as well as the concentration of hydrocarbon in the water, were found to affect the rate and extent of accumulation. Hydrocarbons accumulated were rapidly, although incompletely, discharged when the oysters were transferred to an uncontaminated system. Amounts of hydrocarbons discharged and amounts retained after discharge are probably related to the level of contamination. The data can be interpreted as indicating that equilibration and the occurrence of multiple compartments where hydrocarbons can reside are factors involved in the uptake and retention of nonbiogenic hydrocarbons by oysters. The petroleum hydrocarbons contained in the oysters differed from the contaminating oil by displaying a greater aromatic content. In addition, gas-liquid chromatograms of aliphatic fractions of the hydrocarbons in the oysters rapidly showed a degraded appearance; the possibility that the oysters themselves are modifying the oil cannot be excluded.
Do Corporate Global Environmental Standards Create or Destroy Market Value

Arguments can be made on both sides of the question of whether a stringent global corporate environmental standard represents a competitive asset or liability for multinational enterprises (MNEs) investing in emerging and developing markets. Analyzing the global environmental standards of a sample of U.S.-based MNEs in relation to their stock market performance, we find that firms adopting a single stringent global environmental standard have much higher market values, as measured by Tobin'sq, than firms defaulting to less stringent, or poorly enforced host country standards. Thus, developing countries that use lax environmental regulations to attract foreign direct investment may end up attracting poorer quality, and perhaps less competitive, firms. Our results also suggest that externalities are incorporated to a significant extent in firm valuation. We discuss plausible reasons for this observation.
Measurement of the low-current base and emitter resistances of bipolar transistors

A new ac method is proposed to measure the emitter and base resistances of bipolar transistorsat low current levels at which the effective transistor geometry is given by the processing and is unaffected by the changes induced by high currents. The technique is based on a measurement of the input impedance at frequencies below about 50 MHz. It is particularly suited for the measurement of the physical emitter resistance of scaled transistors. The method is illustrated on microwave transistors with metal contacts and on self-aligned digital transistors with polysilicon contacts. A comparison of the results obtained using this method with those from dc methods operating at high currents can be used to explore the current dependencies of the resistances. The technique is applicable both for homojunction and heterojunction transistors.
Effects of long-term organ culture on neurotransmitter metabolism in the ganglia of Aplysia californica

The abdominal and pedal-pleural ganglia of Aplysia californica were maintained in organ culture for periods up to 45 days. Neurophysiological examination of abdominal ganglia indicated that synaptic activity could be evoked in ganglia cultured for 21 days and action potentials and spontaneous postsynaptic potentials persisted for 45 days. The effects of long-term culture on neurotransmitter metabolism were studied by measuring the activities of ChAc, AChE, AAD, and COMT in both cultured abdominal and pedal-pleural ganglia. G-6-PD and CarnAc activities were also measured. In general, the stabilities of the enzymes in abdominal ganglia to in vitro conditions were similar to those in pedal-pleural ganglia. None of the enzymes studied were markedly affected by culture conditions for at least fourteen days. After this time, enzymes involved in neurotransmitter synthesis, AAD and ChAc, exhibited fairly abrupt decreases in activity. The degradative enzymes studied, AChE and COMT, showed more gradual decreases in activity. The changes occurring in the neurotransmitter metabolizing enzymes after prolonged periods of time in culture are discussed in relation to the neurophysiological changes which were observed.
Improving SRAM Vmin and yield by using variation-aware BTI stress

We propose a novel method that exploits BTI to partially offset variation and thus improve SRAM Vmin and yield. We show correlation between a bitcell's power-up state and its static noise margin. By applying stress with periodic re-power-up, device mismatch can be compensated by BTI induced changes. The proposed method has no extra design and area cost. It can be applied during burn-in test to offset manufacturing variation and/or used during the lifetime of the chip to offset variation from real-time aging and hence continue to improve the margins. Simulations in 45nm show that write, read, and hold Vmin at 6σ can be reduced by 128, 75, and 91 mV, respectively. Measurements from a 16Kb 45nm SRAM demonstrate the improvement of Vmin and yield.
Identification of biomarkers of whole Coxiella burnetii phase I by MALDI-TOF mass spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) specific biomarkers have been shown to be an effective tool for identifying microorganisms. In this study, we demonstrate the feasibility of using this technique to detect the obligate intracellular bacterium Coxiella burnetii, a category B bioterrorism agent. Specific biomarkers were detected in C. burnetii Nine Mile phase I (NMI) strain purified from embryonated egg yolk sac preparations. Whole organisms were applied directly to the MALDI target. MALDI-TOF MS analysis of C. burnetii NMI grown and purified at different times and places revealed a group of unique, characteristic, and reproducible spectral markers in the mass range of 1000−25 000 Da. Statistical analysis of the averaged centroided masses uncovered at least 24 peptides or biomarkers. Three biomarkers observed in the MALDI-TOF MS spectrum consistently matched proteins that had been previously described in C. burnetii, one of them being the small cell ...
Medical Evaluation for Driver Qualification for Patients With Cardiovascular Disorders

BACKGROUND: Primary care physicians commonly care for patients whose disabilities caused by cardiovascular diseases result in difficulty driving an automobile. Patients often seek their physician's advice as to whether they can continue to drive safely. METHODS: A MEDLINE literature search was performed from 1966 to 2000, using the query terms "automobile driving" and "automobile driving and cardiac." Selected articles were reviewed, as well as additional articles found through review of the references. In some cases articles were found by searching the Internet using the above key words and new query terms guided by the results of the original search. RESULTS AND CONCLUSIONS: The most important factor determining eligibility is whether the patient reports manifestations of cerebral hypoxia. Laboratory procedures are available for patients in whom the decision is difficult. Sometimes a referral to a specialist is needed. Many patients with a known cardiovascular disorder can continue to drive safely. Some conditions require a waiting period before driving can be resumed, while others call for a complete cessation of driving. Several guidelines from the literature are listed that can be helpful to primary care physicians when dealing with questions from their patients on this important topic. Language: en
Increased prevalence of obesity and obesity-related postoperative complications in male patients with meningiomas

Objective The female preponderance of meningiomas may reflect hormonal influences on meningioma growth. We hypothesized that because obesity affects male steroid hormone synthesis, male patients with meningiomas might exhibit a high obesity rate, which, in turn, might increase their frequency of postoperative complications. Methods We retrospectively reviewed male patients who underwent craniotomy for benign meningiomas at our institution between 2001 and 2005 (n = 32) and used male patients undergoing craniotomy for aneurysms (n = 32) or glioblastomas (n = 32) from 2001 to 2005 as control subjects. Body mass index (BMI) greater than 30 kg/m was considered obese. Results Male patients with meningiomas had a higher average BMI (30.2 kg/m) than male patients with aneurysms (BMI = 27.5 kg/m) or gliomas (BMI = 25.9 kg/m) (P = 0.04). The obesity rate in men with meningiomas (47%) exceeded that in men with aneurysms (19%) or gliomas (3%) (P = 0.2). The median age-normalized BMI percentile was greater in men with meningiomas (67 th percentile) than in men with aneurysms (49th percentile) or gliomas (52 nd percentile) (P = 0.02). Deep vein thrombosis/pulmonary embolus was more common in men with meningiomas (19%) than in men with aneurysms (0%) or gliomas (3%) (P = 0.002). Wound infections were more common in men with meningiomas (6%) than in men with aneurysms (3%) or gliomas (0%) (P = 0.2). The 53% of obese patients with meningiomas who were readmitted with postoperative complications exceeded the 18% of nonobese patients with meningiomas who were readmitted (P = 0.03); complications included deep vein thrombosis and pulmonary embolus (27 and 12%, respectively, in obese and nonobese patients with meningiomas) and postoperative fever (53 and 35%, respectively, in obese and nonobese patients with meningiomas). Conclusion We found that many men with meningiomas are obese, suggesting a hormonal influence on meningiomas in men as well as women. Our results also underscore the high risk of postoperative complications in obese male patients with meningiomas.
Alarm call responsivity of mallard ducklings: I. The acoustical boundary between behavioral inhibition and excitation.

Mallard (Anas platyrhynchos) maternal assembly calls have fast repetition rates (noteslsec,) which promote behavioral excitation in ducklings (i.e., vocalizing, approaching). On the other hand, maternal alarm calls have slow repetition rates, which promote behavioral inhibition (i.e., cessation of vocalizations, “freezing”). This study assesses the nature of the acoustical boundary separating these 2 behavioral states. Maternally naive ducklings were tested to 1 of 2 series of altered alarm calls that either increased or decreased in repetition rate every minute by 2/10 sec. Ducklings in control groups were exposed to a constant repetition rate for comparable periods of time. The inhibitory and disinhibitory responses of ducklings revealed that a relatively sharp acoustical boundary between inhibitory and excitatory repetition rates exists around 2.6 to 2.8 noteslsec. This transitional region happens to coincide with the range within which neither maternal assembly nor maternal alarm calls occur. Thus, there is a genuine match along this acoustical dimension between auditory perception of ducklings and the 2 major species-typical maternal vocalizations of mallards.
Objective and subjective preoperative refraction techniques for wavefront-optimized and wavefront-guided laser in situ keratomileusis

Purpose To determine which of 3 methods for measuring preoperative refractive error yields the best refractive outcomes after wavefront-guided (Visx Star S4) or wavefront-optimized (WaveLight Allegretto Wave) excimer laser in situ keratomileusis (LASIK). Setting Emory Eye Center and Emory Vision, Emory University, Atlanta, Georgia, USA. Methods This retrospective analysis of LASIK, performed from June to December 2007, analyzed sphere, cylinder, and spherical equivalent (SE) refractions generated from 3 methods (manifest refraction, aberrometer autorefraction [CustomVue WaveScan], corneal analyzer autorefraction [Nidek ARK-10000 OPD]), actual programmed treatment, and absolute deviation from ideal treatment (deviation) for each technique. Results In the wavefront-guided group (63 eyes, 33 patients), manifest refraction and aberrometer autorefraction generated similar deviation for sphere and SE; both were significantly better than corneal analyzer autorefraction (P = .02 and P = .03, respectively). Aberrometer autorefraction generated less cylinder deviation than the other methods (both P = .003). In the wavefront-optimized group (61 eyes, 36 patients), manifest refraction generated less deviation for sphere and SE than aberrometer autorefraction or corneal analyzer autorefraction (sphere: P = .005 and P = .009, respectively; SE: P = .005 and P = .002, respectively). Manifest refraction and aberrometer autorefraction cylinder generated similar deviation, while aberrometer autorefraction was less than corneal analyzer autorefraction (P = .041). Conclusions Overall, manifest refraction was most accurate in generating postoperative emmetropia with both laser treatments; however, aberrometer autorefraction produced the least cylinder deviation for wavefront-guided treatment. Corneal analyzer autorefraction produced the least accurate results with both lasers.
A model for analyzing the effect of moving target defenses on enterprise networks

This paper presents an analytical model for determining the effectiveness of moving target defense (MTD) systems in an enterprise network environment. The goal of our model is not to predict the exact probabilities involved with a MTD system, but to provide insight to designers that allows them to make better design decisions when designing their enterprise networks. We validate the model using a simulation-based of attackers and the MTD system.
Apolitical politics: GOP efforts to foster identification from Latinos, 1984–2000

The growth and youth of the U.S. Latino population at the close of the 20th century makes them a desired constituency for both major political parties. Intriguingly, the party organization which has long resisted the recognition of internal voting blocs—the GOP—allocated unprecedented resources between 1980 and 2000 to inspire identification from Latinos. This study investigates the nature of these invitations. Specifically, it reveals how a party, whose organizational identity opposes acknowledging individuals as ethnic group members, appeals to an ethnic group. By examining (a) English and Spanish language television advertisements and (b) elite interview data with Republican Latino strategists, we argue that these ads depict satisfied Latino citizens, emphasize Latino family connections, and eschew traditional political issues. These identification strategies are notable for they may have considerable effects on the American polity at the dawn of, and well into, the 21st century.
The effect of septal lesions on ethanol consumption by rats

The effect of septal lesions on consumption of a sucrose solution containing 4.75% ethanol was assessed using two-bottle and one-bottle tests. Septal and control rats showed very similar levels of alcohol consumption in both tests. During two-bottle testing, both groups demonstrated a clear preference for sucrose solution. During the 15-min one-bottle test, alcohol intake was substantial (means = 2.93 and 2.95 ml/kg) and produced obvious symptoms of inebriation. It is concluded that self-administration of ethanol under these conditions is an appropriate method for brief studies of septal-ethanol interactions.
Detection of plutonium hydride using X-ray photoelectron spectroscopy

Abstract Methods to distinguish trivalent plutonium hydride from trivalent plutonium oxide with X-ray photoelectron Spectroscopy (XPS) were investigated. Spectra were recorded for a black surface hydride film that was prepared on clean plutonium metal by hydrogen exposure. The hydride cannot be differentiated from the trivalent oxide by measurements of the Pu4 f binding energy alone, since the Pu4 f 7 2 binding energies of PuH 2 and Pu 2 O 3 are 425.0 and 424.8 eV, respectively. The peak width (FWHM) ofPuH 2 (3.6eV) was found to be broader than the peak width of Pu 2 O 3 (2.6 eV). Data for chemical state plots were recorded. Although the energy shift of the Pu (83 eV) Auger peak for hydride and oxide was small, its chemical state information is helpful in distinguishing between oxide and hydride compounds. Additional information useful in distinguishing hydride from oxide can be obtained from the peak position of the Pu4 f 7 2 and from a calculation of the surface oxygen concentration. If no oxygen is present and plutonium is in the Pu(III) state, the presence of hydride can be inferred (in the absence of other elemental impurities). Hydride is also detectable when significant oxygen contamination is present. Data on the effect of oxygen on the Pu(0) state, metallic plutonium, showed that the metallic state can easily be detected at oxygen concentrations less than 40 at.%. Thus, in the absence of the metallic state and when the oxygen concentration is less than 40 at.%, hydride is implicated as the surface component. The detection of hydride in the presence of oxygen contamination was confirmed by examination of a hydrided surface that was subsequently oxidized. After sputter etching through the outer oxide layer, the spectral information indicated that hydride was present on the surface.
Student achievement and attitude in a satellite‐delivered high school science course

Abstract This study investigated the effect of satellite‐delivered instruction on student achievement and attitude in a high school anatomy and physiology course. The experimental group included students from seven high schools enrolled in the satellite‐delivered course. The control group consisted of students from seven high schools in which classroom teachers provided instruction. An experimental versus control matched‐pair design was used in the study. Two hypotheses were tested using the t test for dependent samples. The findings show that there was no significant difference between the experimental group and control group in attitude toward anatomy and physiology. However, on the achievement test, the mean post‐test score of the experimental group was significantly higher than that of the control group.
A Post-processing Technique for the Four-step Travel Demand Modeling Executed Through a Feedback Loop

The four-step travel demand model (FSTDM) is the most widely used technique in practice for estimating traffic flow pattern in the transportation network. Traffic assignment problem (TAP) is a key step of the four-step process that determines the flow pattern which forms the basis for scenario analysis of a transportation improvement project. In many cases, different scenarios may differ by little, but FSTDM may lead to network flows which differ significantly or suggest improvements which are inconsistent with the network situation. This inconsistency arises due to solution noise. There are two main sources of this noise; first, the interdependency between the trip distribution and trip assignment steps of FSTDM, and second, the lower level of convergence in the traffic assignment step. This paper presents a methodology to address the aforementioned two issues by a post-processing technique incorporated through a feedback mechanism in the FSTDM. The post-processing technique consists of SMPA-hybrid, perturbation assignment and Origin-Destination (O-D) prioritization schemes. SMPA- hybrid is an improved implementation of traffic assignment algorithm labeled slope-based multi-path algorithm (SMPA) developed by Kumar and Peeta (2010). There are three methodological contributions of this paper. First, the paper presents an enhanced travel demand modeling framework, second, it formulates a hybrid approach by combining the merits of sequential approach and simultaneous approach of solution algorithms for the TAP, and third, it provides a methodology for the O-D prioritization in TAP. The results of computational experiments suggest that the SMPA-hybrid has a superior rate of convergence compared to the SMPA. The results further reveal that a warm start using perturbation assignment and O-D prioritization has significant benefits over the base case of cold start and non-prioritized implementation of the SMPA-hybrid.