cssi/SciSciGPT-SciSciNet huggingface dataset:
Polarization-independent phase modulators enabled by two-photon polymerization

A double-layer polarization-independent liquid crystal (LC) phase modulator is demonstrated and characterized. Using two-photon polymerization process, an ultra-thin partition polymeric film to separate the LC cell into two layers with orthogonal alignment directions is fabricated. Such a thin partition film also helps to reduce the voltage shielding effect. Using a high birefringence and low viscosity LC mixture, 2π phase change at merely 10 V for a He-Ne laser beam is achieved, while keeping a fast response time. Simulation result agrees reasonably well with experimental data.
Humanoid navigation in uneven terrain using learned estimates of traversability

In this paper we explore discrete search-based contact space planning for humanoids using both palm and foot contact in complex unstructured environments. With a high branching factor and sparse contactable regions, it is challenging for the planner to find a contact sequence in such environments quickly. Therefore, we propose to learn a function which predicts traversability — a measure of how quickly the contact space planner can generate contact sequences to traverse a certain region. By including a learned traversability estimate into the heuristic function of the contact space planner, we can bias the planner to search the areas with more contactable regions, and thus find contact sequences more efficiently. In this paper we propose and evaluate two kinds of feature vectors for estimating traversability: Exact Contact Checking (ECC) and Approximate Contact Checking (ACC), which make different trade-offs between speed and accuracy. The experimental results show that the proposed approach using ACC outperforms both ECC and the baseline heuristic for contact space planning; ACC increases the planning success rate by 19% and reduces average planning time by 24% compared to the baseline in difficult environments with uneven terrain.
Gaps in Advertising and Public Relations Education: Perspectives of Agency Leaders:

Just as the advertising and public relations industries are evolving due to the development of new technology and communication tools, so are the demands of education. Through in-depth interviews w...
X-ray Emission Spectroscopy as an in Situ Diagnostic Tool for X-ray Crystallography of Metalloproteins Using an X-ray Free-Electron Laser

Serial femtosecond crystallography (SFX) using the ultrashort X-ray pulses from a X-ray free-electron laser (XFEL) provides a new way of collecting structural data at room temperature that allows for following the reaction in real time after initiation. XFEL experiments are conducted in a shot-by-shot mode as the sample is destroyed and replenished after each X-ray pulse, and therefore, monitoring and controlling the data quality by using in situ diagnostic tools is critical. To study metalloenzymes, we developed the use of simultaneous collection of X-ray diffraction of crystals along with X-ray emission spectroscopy (XES) data that is used as a diagnostic tool for crystallography, by monitoring the chemical state of the metal catalytic center. We have optimized data analysis methods and sample delivery techniques for fast and active feedback to ensure the quality of each batch of samples and the turnover of the catalytic reaction caused by reaction triggering methods. Here, we describe this active in situ feedback system using Photosystem II as an example that catalyzes the oxidation of H2O to O2 at the Mn4CaO5 active site. We used the first moments of the Mn Kβ1,3 emission spectra, which are sensitive to the oxidation state of Mn, as the primary diagnostics. This approach is applicable to different metalloproteins to determine the integrity of samples and follow changes in the chemical states of the reaction that can be initiated by light or activated by substrates and offers a metric for determining the diffraction images that are used for the final data sets.
Undesign: Future consideration on end-of-life of driver cars

The number of autonomous cars operating on the road increases rapidly. What is the effect of autonomous cars on the future of traditional (driver) cars on the short and long term? In this paper, we talk about the possible future of driver and driverless cars as they continue to affect each other. Moving from driver car to driverless car could be a long and hard process or could happen smoothly, if at all. While technology was able to strongly assert itself in this domain by providing robust and reliable performance of autonomous vehicle, little else has been done in evaluating social and cultural aspects. Diver-less vehicles could have significant impact on diverse jobs. Recycling driver cars could be a big challenge. The interplay of driver and driverless cars on the street is not well studied. If the majority of cars on the street became autonomous, their effect on the few remaining driver cars could be a challenge. Can we force all people to use driverless car or do car companies need to continue producing both types of cars, and for how long?
The school of tomorrow: promoting electronic multimedia education in the 1960s

There is one question that joins together nearly all histories of educational film, radio and television: why, in each instance, did these media fail to take hold in the classroom?1 Most often, sch...
“We’re Here to Learn to Speak French”: An Exploration of World Language Teachers’ Beliefs About Students and Teaching

The purpose of this qualitative study was to explore five world language teachers’ beliefs about their students, their attributions about student enrollment, and their reported teaching practices. ...
Plane-Wave Transmission Through an Array of Dielectric-Loaded Slots in a Thick Metallic Screen: Normal Incidence

In this paper, we derive an analytical model for plane-wave transmission through a periodic array of dielectric-loaded slots in an infinite metallic screen of finite thickness (a metagrating). We show the existence of (Fano) resonances associated with the presence of higher order modes in the slots, in addition to the well-known (Fabry–Perot) resonances associated with the dominant mode in the slots. The Fano resonances arise from a physical mechanism distinct from that which is responsible for so-called extraordinary transmission through a grating, which is strongly dependent on the coupling among the slots. Comparison of the analytical model with the results of full-wave simulations shows excellent agreement when the characteristic dimensions of the grating are small compared with a free-space wavelength.
Strategies for Selecting Routes through Real-World Environments: Relative Topography, Initial Route Straightness, and Cardinal Direction.

Previous research has demonstrated that route planners use several reliable strategies for selecting between alternate routes. Strategies include selecting straight rather than winding routes leaving an origin, selecting generally south- rather than north-going routes, and selecting routes that avoid traversal of complex topography. The contribution of this paper is characterizing the relative influence and potential interactions of these strategies. We also examine whether individual differences would predict any strategy reliance. Results showed evidence for independent and additive influences of all three strategies, with a strong influence of topography and initial segment straightness, and relatively weak influence of cardinal direction. Additively, routes were also disproportionately selected when they traversed relatively flat regions, had relatively straight initial segments, and went generally south rather than north. Two individual differences, extraversion and sense of direction, predicted the extent of some effects. Under real-world conditions navigators indeed consider a route’s initial straightness, cardinal direction, and topography, but these cues differ in relative influence and vary in their application across individuals.
Coordinating multi-robot systems through environment partitioning for adaptive informative sampling

As robotic platforms have become more capable and autonomous, they have increasingly been utilized in time sensitive applications such as search and rescue. To that end, we have developed a system for teams of robots to efficiently explore an environment while taking sensor measurements. The system utilizes an information seeking algorithm that generates high priority points of interest based on the highest expected information gained per distance travelled. In order to coordinate multiple robots, the system partitions the area into different regions according to the effort needed to explore each region. Robots are assigned different regions to measure in order to minimize repetition of work and reduce interference between each robot.We present an information rate adaptive sampling approach for tasking robots within an environment to gather sensor measurements. We evaluated our approach within a simulation environment with one to four robots. Multiple robots are coordinated through our region segmentation approach. The data shows efficiency gains through the use of adaptive information gain rate tasking above a naive closest point approach. We also see positive results from using the region segmentation technique. We further the experimentation by testing the algorithm on real world robots and verify the results in real world experimentation.
The Untapped Potential of Preschool Classroom Volunteers in Language–Literacy Instruction: A Feasibility Study

Purpose This pretest–posttest study examined the effects of a professional development training on five volunteer instructors' (VIs) utilization of language and literacy facilitation strategies wit...
Closed-loop Control of Sacral Neuromodulation for Bladder Function using Dorsal Root Ganglia Sensory Feedback in an Acute Feline Model

Overactive bladder patients suffer from a frequent and uncontrollable urge to urinate, which can lead to a poor quality of life. Current sacral neuromodulation therapy uses open-loop electrical stimulation to alleviate symptoms, which limits battery life and can lead to neural habituation. In this study, we aim to improve therapy by developing a conditional stimulation paradigm using neural recordings from dorsal root ganglia (DRG) as sensory feedback. Experiments were performed in 5 non-survival, anesthetized felines, in which the sacral-level DRG and spinal roots were exposed bilaterally. A bipolar cuff electrode was placed on a S1 root distal to the DRG for stimulation. Microelectrode arrays were implanted in the same or opposite S1 and/or S2 DRG. We implemented a Kalman filter-based algorithm to estimate the bladder pressure in real-time using DRG neural recordings. The Medtronic Summit Research Development Kit was used to control sacral root stimulation when the algorithm detected an increase in bladder pressure. Closed-loop neuromodulation was performed during continuous cystometry and compared to bladder fills with continuous and no stimulation. Overall, closed-loop stimulation with DRG sensory feedback increased bladder capacity by 13.8% over no stimulation (p
Complexity bounds for approximately solving discounted MDPs by value iterations

Abstract For an infinite-horizon discounted Markov decision process with a finite number of states and actions, this note provides upper bounds on the number of operations required to compute an approximately optimal policy by value iterations in terms of the discount factor, spread of the reward function, and desired closeness to optimality. One of the provided upper bounds on the number of iterations has the property that it is a non-decreasing function of the value of the discount factor.
Evaluation of cognitive function in patients with severe anorexia nervosa before and after medical stabilization

The purpose of this study was to quantify cognitive deficits in severe anorexia nervosa (AN) before and after medical stabilization. This was a prospective study of 40 females between the ages of 18 and 50 admitted to a medical stabilization unit with severe AN (%IBW < 70). The primary outcome of the study was change in test scores on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) at baseline and after medical stabilization. There were no statistically significant differences in baseline RBANS scores between AN patients overall and controls (p = 0.0940). There was a statistically significant change in RBANS from baseline 94.1 + 12.7 to medical stabilization 97.1 + 10.6 (p = 0.0173), although notably both mean values fell within the average range. There were no significant differences in baseline RBANS scores between controls and AN-BP patients (p = 0.3320) but significant differences were found between controls and AN-R patients (p = 0.0434). No baseline deficits in cognition were found in this sample of women with severe AN.
Early impact of the 2018 AHA/ACC/multisociety cholesterol guideline on lipid monitoring after statin initiation

Background The 2018 AHA/ACC/multisociety cholesterol guideline emphasizes the need for lipid monitoring more strongly than the previous 2013 guideline to ensure patients reach recommended percent low-density lipoprotein cholesterol reductions. Real-world compliance to monitoring recommendations is currently unknown. Objectives This study examined the proportion of patients with a lipid panel measured within 3 months of statin initiation. Methods This retrospective cohort study evaluated University of Colorado Health primary care patients aged 18 to 89 years with a new statin prescription identified via the Epic Clarity database. Patients initiated on a statin during January 1, 2018 to June 30, 2018 and January 1, 2019 to June 30, 2019 were included in the pre-2018 guideline cohort and the post-2018 guideline cohort, respectively. Patients with active liver disease, pregnancy, or missing demographic data were excluded. Results A total of 13,726 patients were included, 7476 in the preguideline cohort and 6250 in the postguideline cohort. A total of 13.9% of patients in the preguideline cohort had a lipid panel completed within 3 months of statin initiation compared with 16.2% in the postguideline cohort (adjusted P Conclusion In a large integrated health system, lipid monitoring increased among patients newly started on statin therapy soon after release of the 2018 guideline but remains low. Clinical interventions are needed to improve lipid monitoring to optimize low-density lipoprotein cholesterol–lowering therapy and ensure that guideline-recommended goals are achieved.
Start low, go fast? Antipsychotic titration patterns at an inpatient psychiatric hospital.

Introduction Antipsychotics are commonly used to treat psychotic symptoms and severe mental illnesses. Treatment guidelines recommend antipsychotics be titrated quickly to therapeutic effect in the acute setting but acknowledge that determining the optimal dose is complicated by a delay between treatment initiation and therapeutic response. The purpose of this study was to evaluate antipsychotic titration patterns in an inpatient psychiatric hospital. Methods This study is a retrospective chart review of adult patients admitted to a teaching hospital and initiated on an antipsychotic for treatment of psychosis between January and December 2018. Patients were excluded if they had substance-induced psychosis, delirium, were prescribed >1 antipsychotic, or had no antipsychotic dose changes. The primary outcome was the average titration rate of the newly initiated antipsychotic. Secondary outcomes included differences in titration rate between involuntary and voluntary admissions and other antipsychotic characteristics. Results Of 149 patients included, the majority had a primary diagnosis of schizophrenia. Antipsychotics were titrated on average every 2 days regardless of admission type. Eighteen percent of patients were titrated to guideline-recommended maximum doses, and it took, on average, 3 days for patients to reach their final dose during hospitalization. Average length of stay was 9 days, and 43.6% of patients were readmitted within 1 year. Discussion Antipsychotics are titrated rapidly in the inpatient setting despite a lack of evidence regarding the impact of titration rate on clinical outcomes. Further studies comparing slow versus rapid titration strategies are needed to elucidate the impact of this on patient outcomes.
Re-appraising the potential of naringin for natural, novel orthopedic biotherapies.

Naringin is a naturally occurring flavonoid found in plants of the Citrus genus that has historically been used in traditional Chinese medical regimens for the treatment of osteoporosis. Naringin modulates signaling through numerous molecular pathways critical to musculoskeletal development, cellular differentiation, and inflammation. Administration of naringin increases in vitro expression of bone morphogenetic proteins (BMPs) and activation of the Wnt/β-catenin and extracellular signal-related kinase (Erk) pathways, thereby promoting osteoblastic proliferation and differentiation from stem cell precursors for bone formation. Naringin also inhibits osteoclastogenesis by both modifying RANK/RANKL interactions and inducing apoptosis in osteoclasts in vitro. In addition, naringin acts on the estrogen receptor in bone to mimic the native bone-preserving effects of estrogen, with few systemic side effects on other estrogen-sensitive tissues. The efficacy of naringin therapy in reducing the osteolysis characteristic of common musculoskeletal pathologies such as osteoporosis, degenerative joint disease, and osteomyelitis, as well as inflammatory conditions affecting bone such as diabetes mellitus, has been extensively demonstrated in vitro and in animal models. Naringin thus represents a naturally abundant, cost-efficient agent whose potential for use in novel musculoskeletal biotherapies warrants re-visiting and further exploration through human studies. Here, we review the cellular mechanisms of action that have been elucidated regarding the action of naringin on bone resident cells and the bone microenvironment, in vivo evidence of naringin's osteostimulative and chondroprotective properties in the setting of osteolytic bone disease, and current limitations in the development of naringin-containing translational therapies for common musculoskeletal conditions.
Toward Using Twitter for Tracking COVID-19: A Natural Language Processing Pipeline and Exploratory Data Set.

Background: In the United States, the rapidly evolving COVID-19 outbreak, the shortage of available testing, and the delay of test results present challenges for actively monitoring its spread based on testing alone. Objective: The objective of this study was to develop, evaluate, and deploy an automatic natural language processing pipeline to collect user-generated Twitter data as a complementary resource for identifying potential cases of COVID-19 in the United States that are not based on testing and, thus, may not have been reported to the Centers for Disease Control and Prevention. Methods: Beginning January 23, 2020, we collected English tweets from the Twitter Streaming application programming interface that mention keywords related to COVID-19. We applied handwritten regular expressions to identify tweets indicating that the user potentially has been exposed to COVID-19. We automatically filtered out “reported speech” (eg, quotations, news headlines) from the tweets that matched the regular expressions, and two annotators annotated a random sample of 8976 tweets that are geo-tagged or have profile location metadata, distinguishing tweets that self-report potential cases of COVID-19 from those that do not. We used the annotated tweets to train and evaluate deep neural network classifiers based on bidirectional encoder representations from transformers (BERT). Finally, we deployed the automatic pipeline on more than 85 million unlabeled tweets that were continuously collected between March 1 and August 21, 2020. Results: Interannotator agreement, based on dual annotations for 3644 (41%) of the 8976 tweets, was 0.77 (Cohen κ). A deep neural network classifier, based on a BERT model that was pretrained on tweets related to COVID-19, achieved an F1-score of 0.76 (precision=0.76, recall=0.76) for detecting tweets that self-report potential cases of COVID-19. Upon deploying our automatic pipeline, we identified 13,714 tweets that self-report potential cases of COVID-19 and have US state–level geolocations. Conclusions: We have made the 13,714 tweets identified in this study, along with each tweet’s time stamp and US state–level geolocation, publicly available to download. This data set presents the opportunity for future work to assess the utility of Twitter data as a complementary resource for tracking the spread of COVID-19.
Incessant Atrial Tachycardia as First Presentation of Cardiac Angiosarcoma.

Abstract Primary cardiac angiosarcomas are rare malignant tumors with a very poor prognosis. We present a case of a 48-year-old man with no previous cardiac history who developed an incessant focal atrial tachycardia complicated by tachycardia-mediated cardiomyopathy as a consequence of cardiac angiosarcoma. (Level of Difficulty: Beginner.)
Corn Response to Sulfur Fertilization when Grown on Irrigated Sandy Soil

Materials and Methods Soil type was a Fruitfield coarse sand soil with approximately 1.5 percent organic matter and soil pH of 6.0 (buffer pH of 7.0). A spring soil test reported 134 ppm P (very high), 98 ppm K (low), and 11 ppm S (low/medium) in the topsoil. Spring tillage included chisel plowing and disking. Pioneer P1324 hybrid corn seed was planted on May 7. Plant emergence was uniform and final stand counts averaged 31,000 plants/acre. Weed control was achieved by applying s-metolachlor + atrazine + mesotrione herbicide crop pre-emergence on May 13 and a post emergence application of glufosinate + atrazine on June 11. Potash (0-0-60) fertilizer was broadcast at a rate of 200 lb/acre on April 4. Total N (nitrogen) application for the season was 200 lb/acre and applied in split applications as dry urea broadcast on May 24 and liquid UAN through irrigation on July 2 and July 20. Plots were arranged in a randomized complete block design with four replications. A treatment plot consisted of six rows 50 ft long. Calcium sulfate (21% Ca, 17% S) was used as the sulfur source and banded between plot rows at rates equal to 10, 20, and 40 lb/acre sulfur on May 29. An irrigation water sample was collected in July for quality analysis by Texas A&M Water Testing Laboratory, College Station, Texas. Plant tissue sampling occurred on July 19 when corn was at the R1 growth stage by collecting leaves that were opposite and below the primary ear. Plant samples were sent to A&L Analytical Laboratories, Memphis, Tennessee, for nutrient concentration analysis. Yield determinations were made on October 16 by harvesting the center two rows of each plot.
Vertical Integration and the Restructuring of the U.S. Electricity Industry

Debates on restructuring of the U.S. electricity industry are often about the degree to which market relationships should replace transactions that formerly took place within regulated, vertically integrated utilities. Markets for the purchase of energy by vertically unintegrated distribution utilities are clearly feasible, but vertical deintegration of existing systems may entail foregoing some operational and reliability benefits that are important in light of electricity's unique characteristics. Research and policy on restructuring have almost totally disregarded a large econometric literature on the savings from vertical integration. At the same time, policy makers have accepted the results of flawed studies that purport to estimate the benefits of switching to a market regime. A review of California's restructuring history shows that vertical integration was viewed primarily as a tool that incumbent utilities might use to perpetuate their market power. The disregard of its benefits led to questionable divestitures that produced superficially competitive market structures, and to the institution of Independent System Operators whose costs have yet to be compared to their benefits.
Implementation Issues of Loop-Level Speculative Run-Time Parallelization

Current parallelizing compilers cannot identify a significant fraction of parallelizable loops because they have complex or statically insufficiently defined access patterns. We advocate a novel framework for the identification of parallel loops. It speculatively executes a loop as a doall and applies a fully parallel data dependence test to check for any unsatisfied data dependencies; if the test fails, then the loop is re-executed serially. We will present the principles of the design and implementation of a compiler that employs both run-time and static techniques to parallelize dynamic applications. Run-time optimizations always represent a tradeoff between a speculated potential benefit and a certain (sure) overhead that must be paid. We will introduce techniques that take advantage of classic compiler methods to reduce the cost of run-time optimization thus tilting the outcome of speculation in favor of significant performance gains. Experimental results from the PERFECT, SPEC and NCSA Benchmark suites show that these techniques yield speedups not obtainable by any other known method.
Economic benefits of hydraulic-electric hybrid wind turbines

As wind turbines increase to multi-megawatt power ratings and move offshore, the costs associated with maintenance, support structure and infrastructure will escalate. The proposed hydraulic-electric hybrid turbine design with compressed air energy storage (CAES) can meet these concerns. This study considers the cost implications of this design, both with and without CAES. The model uses the National Renewable Energy Laboratory 5 MW offshore reference turbine as a baseline and is validated with existing correlations and industry data. The results show that a hybrid system without CAES eliminates the gearbox and reduces tower mass by 36%, leading to capital expenditure (CAPEX) reduction of 6%. Adding CAES substantially reduces generator size by 65% and electrical infrastructure by 55%, yielding a total CAPEX reduction of 17%, but also reducing total energy output by about 10%. Additional cost reductions are expected but need to be quantified with a full lifecycle cost assessment.
The Functional Forecast Model of Emotion Expression Processing

Fleeting nonverbal emotion expressions trigger a variety of spontaneous responses in human observers. To account for these effects, we introduce a functional forecast model (FFM) of emotion expression processing. The FFM assumes that emotion expressions provide timely forecasts of impending events. Responses to these forecasts are adaptive and may be learned or innately prepared, but in either case, observers need not infer mental states to exhibit immediate responses to emotion expressions. We postulate a diffuse route that operates pre-attentively and activates appetitive and defensive motivational systems in response to gross affective meaning relevant to imminent environmental threats and available or scarce survival resources. We postulate a focal route that requires attention to efficiently and spontaneously activate specific, though tacit behavioral expectations. We explain how the FFM accounts for a variety of responses to emotion expressions, including physiological responses, affective responses, behavioral responses, trait attributions, and emotion recognition. Lastly, we describe how the FFM relates to other models of emotion, and describe future directions based on the model.
Implementing Efficient Dynamic Formal Verification Methods for MPI Programs

We examine the problem of formally verifying MPI programs for safety properties through an efficient dynamic (runtime) method in which the processes of a given MPI program are executed under the control of an interleaving scheduler. To ensure full coverage for given input test data, the algorithm must take into consideration MPI's out-of-order completion semantics. The algorithm must also ensure that nondeterministic constructs (e.g., MPI wildcard receive matches) are executed in all possible ways. Our new algorithm rewrites wildcard receives to specific receives, one for eachsender that can potentially match with the receive. It then recursively explores each case of the specific receives. The list of potential senders matching a receive is determined through a runtime algorithm that exploits MPI's operation ordering semantics. Our verification tool ISP that incorporates this algorithm efficiently verifies several programs and finds bugs missed by existing informal verification tools.
Enzymatic digestion of proteins on PVDF membranes.

Enzymatic digestion of membrane-bound proteins is one of the most widely used procedures for determining the internal amino acid sequence of proteins that either have a blocked amino terminus or require two or more stretches of sequence data for DNA cloning or confirmation of protein identification. Because the final step of protein purification is usually SDS-PAGE, electroblotting to either polyvinylidene difluoride (PVDF) or nitrocellulose is the simplest and most common procedure for recovering protein free of contaminants (e.g., SDS or acrylamide) with a high yield. As described in this unit, PVDF is preferred over nitrocellulose because it can be used for a variety of other structural analysis procedures, such as amino-terminal sequence analysis and amino acid analysis. In addition, peptide recovery from PVDF membranes is higher than from nitrocellulose, particularly from higher-retention PVDF (e.g., ProBlott, Transblot, Westran, or Immobilon P(sp)). Finally, PVDF-bound protein can be stored dry, as opposed to nitrocellulose-bound protein, which must remain wet during handling and storage to prevent loss of peptides during digestion.
Pathogenicity Studies on Trichomonas gallinarum in Domestic Poultry

Abstract A STUDY of the pathogenicity of Trichomonas gallinarum was initiated following reports of low egg production due to trichomoniasis in laying flocks in the Southeastern United States. Several diagnosticians had reported trichomonads of the lower digestive tract as the primary pathogenic agents detected in these flocks. They have generally followed the standard textbooks on poultry disease (Barger et al., 1958; and Biester and Schwarte, 1959) in ascribing pathogenicity to these organisms. Becker, who reviews this subject in the latter text, is the author most frequently quoted. In this section Allen’s publications (1936, 1940, 1941) and Olsen and Allen (1942) together with other quotations give the impression that the organism is a pathogen. Allen described (1941) elevated, cheesy, cream-colored hepatic lesions which she claimed could be differentiated from the depressed lesions caused by Histomonas meleagridis. In reviewing Allen’s work Stabler (1947) indicated that confirmatory experiments were required. Among others who have…
Calcium-Activated SK Channels Influence Voltage-Gated Ion Channels to Determine the Precision of Firing in Globus Pallidus Neurons

Globus pallidus (GP) neurons fire rhythmically in the absence of synaptic input, suggesting that they may encode their inputs as changes in the phase of their rhythmic firing. Action potential afterhyperpolarization (AHP) enhances precision of firing by ensuring that the ion channels recover from inactivation by the same amount on each cycle. Voltage-clamp experiments in slices showed that the longest component of the GP neuron's AHP is blocked by apamin, a selective antagonist of calcium-activated SK channels. Application of 100 nm apamin also disrupted the precision of firing in perforated-patch and cell-attached recordings. SK channel blockade caused a small depolarization in spike threshold and made it more variable, but there was no reduction in the maximal rate of rise during an action potential. Thus, the firing irregularity was not caused solely by a reduction in voltage-gated Na(+) channel availability. Subthreshold voltage ramps triggered a large outward current that was sensitive to the initial holding potential and had properties similar to the A-type K(+) current in GP neurons. In numerical simulations, the availability of both Na(+) and A-type K(+) channels during autonomous firing were reduced when SK channels were removed, and a nearly equal reduction in Na(+) and K(+) subthreshold-activated ion channel availability produced a large decrease in the neuron's slope conductance near threshold. This change made the neuron more sensitive to intrinsically generated noise. In vivo, this change would also enhance the sensitivity of GP neurons to small synaptic inputs.
Attenuation of nucleus basalis of Meynert lesion-induced cholinergic deficits by nerve growth factor

Abstract Nerve growth factor (NGF) was administered into either the lateral ventricle or into the basal forebrain of n. basalis of Meynert (nbM) lesioned rats. Rats received either continuous infusion of 5 μg of 7S NGF per day for 28 days, or 5 μg of 7S NGF on 4 occasions distributed evenly during the first two post-lesion weeks. The administration of NGF reduced lesion-induced cortical cholinergic marker deficits by approximately 50%, irrespective of the locus or mode of NGF administration. Thus NGF is able to attenuate lesion-induced cholinergic deficits across a range of treatment and lesion conditions.
Cell biology: a new view of photoreceptors.

The light-gathering structures in our eyes are specialized membranes found on cells known as photoreceptors. Two studies show that a protein called Crumbs is crucial for the development of these membranes.
PARAMETERS OF TEXTURE CHANGE IN PROCESSED FISH: CROSS-LINKAGE OF PROTEINS

Soluble myosin and insoluble protein (i. e., soluble only in 5 % sodium dodecyl sulfate) were obtained from fresh and processed Sacramento blackfish and analyzed for the existence of possible cross-links. Free sulfhydryl groups decreased somewhat in freezing and more in frozen storage. None were present after dehydration or cooking nor in any insoluble fractions, so that presumably these were oxidized in the formation of cross-links. Ester bonds were much more numerous in insoluble protein than in soluble myosin, but their relative content was not clearly related to processing. Aldehyde groups decreased in myosin after cooking and dehydration, and were absent from insoluble protein. The presumptive Schiff base content was somewhat greater in soluble protein than in myosin and appeared to increase upon freezing and dehydration.
President's report: Tides of change--Teachers at the helm

That monumental report, while startling to some, served only to strengthen the resolve of mathematics educators in the United States and Canada. We realMary M. Lindquist ized that no longer could we each sail our own ship without direction. We had to chart a new course. We realized that if we are to enhance our education system, we must raise our standards. If we are to prepare our students for the future, we must use the technology of today. If we are charged with laying a foundation for students' success, we must teach mathematics with real-world applications, mathematics that makes sense, mathematics that instills in our students the confidence to say "I can." Out of this situation was born NCTM's Curriculum and Evaluation Stan-
The extraction of nitric acid and thorium nitrate by tri-n-octylphosphine oxide in cyclohexane

Abstract The distribution of nitric acid and thorium(IV) nitrate between aqueous solutions and solutions of tri-n-octylphosphine oxide in cylcohexane has been examined as a function of temperature and various extraction variables at constant aqueous ionic strength. Up to a maximum concentration of 0·4 M, the distribution behaviour of nitric acid was found to be consistent with first power dependency on the organic reagent concentration. In the case of acidic thorium nitrate solutions, provided the concentration of both thorium(IV) and hydrogen ion are maintained below 0·01 M, the extraction of the metal as Th(NO 3 ) 4 ·3TOPO is indicated. At higher concentrations the formation of organic adducts containing both the metal nitrate and nitric acid takes place. The temperature dependency of the extraction is very small in the case of the acid extraction and too slight in the case of thorium nitrate to be observed by the analytical methods used. During the course of these studies the solubility and density of saturated tri-n-octylphosphine oxide solutions in cyclohexane in the temperature range of 6·5–35°C was also measured.
Enhanced acquisition of reversal training in a spatial learning task in rats treated with chronic nimodipine.

Abstract Nimodipine levels we were measured in blood and brain of rats implanted SC with sustained-release pellets of nimodipine (0, 10, 20, or 40 mg). Dose-dependent levels of nimodipine were detected in both plasma and brain. These results indicated the possible usefulness of these pellets in behavioral studies where long-term treatment is required. Therefore, the effects of chronic nimodipine, using 40-mg pellets, were examined on the performance of young, middle-aged, and aged rats in the Morris water maze. Following implantation of either nimodipine or placebo pellets, rats were trained for 6 days (three sessions/day) followed by 6 days of reversal training. During both initial and reversal training, every sixth trial was a probe trial. During initial training, there were clear age-related acquisition deficits in place training, with no effects of chronic nimodipine. Nimodipine did, however, enhance performance of rats during the first and second probe trials of reversal training. Time spent in the training quadrant by nimodipine-treated ratswas approximately 30% longer on the first reversal probe and 35% longer on the second reversal probe than time spent in this quadrant by placebo-treated animals. These results indicate that chronic nimodipine enhances the performance of normal animals in reversal training on a spatial learning task.
Reply: Missing ligand model in autologous stem cell transplantation

Sir, We agree with Stern et al that missing KIR-ligand does not imply inhibitory KIR–HLA receptor–ligand mismatch. In fact, 2 out of our 16 patients (13%) would have been misclassified using the analytic approach of Stern et al (one for KIR3DL1–Bw6/6 and the other for KIR2DL1–HLA-CAsn80/Asn80). The statistical implication for misclassification and exclusion of patients missing Bw4 cannot be overemphasised. For example, previous publication studying the effects of HLA mismatch has already demonstrated the statistical effect (bias towards null) with misclassification involving only 2–3 patients among 130 individuals (Leung et al, 2001). Furthermore, exclusion of KIR3DL1–Bw4 from any examination of KIR–HLA interaction will have similar statistical effect. For instance in our study, a prominent KIR3DL1 mismatch effect was observed: six out of the seven patients (86%) with mismatch involving KIR3DL1 were alive, whereas only two out of the nine patients (22%) without KIR3DL1 mismatch were alive (P=0.01, Figure 1). If the analytic approaches of Stern et al were used on our cohort, we would have concluded erroneously that neither inhibitory KIR–HLA receptor–ligand mismatch nor the number of mismatch pairs had any effect on clinical outcome (HR for relapse=0.49 (95% CI: 0.1–2.8), P=0.43). Therefore, we agree with Stern et al that our intriguing findings should be confirmed in large studies, which use biologically appropriate model, prospective design, uniform conditioning regimen and graft processing, analyses accounting for confounders such as disease type or status, and direct assessment of KIR expression on NK cells providing proof that all patients who are assumed to possess and express all relevant inhibitory KIRs indeed do so (Leung et al, 2004, 2005). Figure 1 Event-free survival (EFS) of patients with receptor–ligand mismatch involving KIR3DL1 and of those with no mismatch.
Interleukin-1 potentiation of β-endorphin secretion and the dynamics of interleukin-1 internalization in pituitary cells

Abstract 1. This study demonstrates that human recombinant Interleukin-1 (IL-1) stimulates β-endorphin release and potentiates the secretion of β-endorphin in both a mouse anterior pituitary cell line AtT-20 and rat pituitary cell cultures. 2. In pituitary cell cultures, prolonged treatment with phorbol ester had no effect on IL-1-induced β-endorphin release, but abolished the potentiating effects of IL-1 on vasopressin-induced β-endorphin secretion. 3. The enhancement of CRF-stimulated β-endorphin release by IL-1 was also reduced in normal pituitary cell cultures following depletion of protein kinase C. 4. The late IL-1-induced secretion of β-endorphin does not require the continuous presence of the cytpkine. 5. Incubation of monolayers with 125 I-IL-1α (10 −9 M) at 8°C and then at 37°C for various times revealed that IL-1α was internalized. There was a progressive increase in the ratio of cytoplasmic to cell-surface-associated 125 I-IL-1α. 6. These results indicate that the IL-1-induced β-endorphin release and its potentiation of β-endorphin secretion involves internalization of this cytokine, perhaps via cell surface IL-1 receptors.
Nitrogen Transformations and Microbial Communities in Soil Aggregates from Three Tillage Systems

Quantifying N transformation processes in soil aggregates is relevant since microbial communities central to the N cycle may differ among aggregate size fractions. Our objective was to test the hypothesis that variations in microbial community composition of aggregate size fractions influence N transformation rates of soil from three long-term (22-yr) tillage systems (no-till, chisel plow, and moldboard plow). Aggregate size fractions (2-4, 0.5-1, and <0.25 mm) were obtained by dry sieving. Nitrogen transformation rates were estimated by analysis of 15 N pool dilution data with the FLUAZ model, and microbial community composition by phospholipid fatty acid (PLFA) profiles. Aggregate size fraction and tillage system had significant (P < 0.01) effects on total and microbial biomass C and N, gross N mineralization rate (GNMR), gross nitrification rate (GNR), and gross N immobilization rate (GIR). No-till soils and the 0.5- to 1.0-mm aggregate size fraction had the highest N transformation rates. Net N mineralization rates were greater for no-till than for tilled soils. Multiple response permutation analysis of PLFA data revealed that microbial community composition did not differ with aggregate size fraction. Stepwise regression analysis indicated that microbial community composition (nonmetric multidimensional scaling Axis 1) accounted for 89% of the variation in GIR, soil C and N concentrations accounted for 88% of the variation in GNMR, and microbial biomass C concentration accounted for 81% of the variation in GNR. These results indicate that greater N transformation rates in no-till than tilled soil were due primarily to increased microbial biomass (i.e., microbial population size) rather than altered microbial community composition.
Lichens and bryophytes of the alpine and subalpine zones on Katahdin, Maine, II: Lichens

Abstract A total of 293 different lichens (and lichenicolous fungi) were found above an elevation of 884 m on Katahdin during fieldwork from 2000 to 2004 and from study of previously collected herbarium specimens. Thirteen of these are new to North America, 39 additional lichens are new to northeastern United States and 26 additional ones are new to Maine; three additional taxa are almost certainly new to science but are not formally described in this study. We identified eight distinct lichen habitats on Katahdin: (1) A1, exposed alpine tundra and fellfields; (2) A2, high elevation alpine sites protected from northwest winds; (3) A3, east-facing alpine late-snow areas; (4) A4, alpine krummholz; (5) A5, cirque headwalls facing east and north; (6) A6, cirque headwall facing southeast; (7) B1, exposed low-altitude tundra, talus and krummholz; and (8) B2, subalpine forests. Each habitat except A4 had numerous lichens (10–56 taxa) found in none of the others, and each differed statistically from two to six ot...
Method to generate true random numbers in HDD without additional hardware

A novel method is provided for true random number generation in a hard disc drive (HDD). The method is based on the back electromotive force (BEMF) of voice coil motor (VCM) of a HDD with actuator vibrating on the ramp, whose value is dominated by electrical noise from PCB, electrical components parameters change with environment and servo-mechanical system. With this phenomenon, a BEMF value is used to generate a bit of the random number by determining whether the value is odd or even. The multi-dimensional chi-squared test method is used to verify the randomness of the data. The method is to use just the existing HDD hardware thus without any additional cost, and it can be applied for the application where HDD is not required to spin up during system boot up.
An economical method to calculate eigenvalues of the Schrödinger equation

A method is presented which is an extension to negative energies of a spectral integral equation method to solve the Schroedinger equation, developed previously for scattering applications. One important innovation is a re-scaling procedure in order to compensate for the exponential behaviour of the negative energy Green's function. Another is the need to find approximate energy eigenvalues, to serve as starting values for a subsequent iteration procedure. In order to illustrate the new method, the binding energy of the He–He dimer is calculated, using the He–He TTY potential. In view of the small value of the binding energy, the wavefunction has to be calculated to a distance of 3000 au. Two hundred and twenty mesh points were sufficient to obtain an accuracy of three significant figures for the binding energy, and with 320 mesh points the accuracy increased to six significant figures. An application to a potential with two wells, separated by a barrier, is also made.