cssi/SciSciGPT-SciSciNet huggingface dataset:
A Current-fed High Gain Multilevel DC-DC Converter for BESS Grid Integration Applications

This paper presents a new high gain, multilevel, bidirectional DC-DC converter for interfacing battery energy storage systems (BESS) with the distribution grid. The proposed topology employs a current-fed structure on the low-voltage (LV) BESS side to obtain high voltage gain during battery-to-grid mode of operation without requiring a large turns ratio isolation transformer. The high-voltage (HV) side of the converter is a voltage-doubler network comprising two half-bridge circuits with an intermediary bidirectional switch that re-configures the two bridges in series connection to enhance the boost ratio. A seamless commutation of the transformer leakage inductor current is ensured by the phase-shift modulation of HV side devices. The modulating duty cycle of the intermediary bidirectional devices generates a multilevel voltage of twice the switching frequency at the grid-side dc link, which significantly reduces the filter size. The presented modulation strategy ensures zero current switching (ZCS) of the LV devices and zero voltage switching (ZVS) of the HV devices to achieve a high power conversion efficiency. Design and operation of the proposed converter is explained with modal analysis, and further verified by detailed simulation results.
In defense of Direct Care: Limiting access to military hospitals could worsen quality and safety.

OBJECTIVE Ongoing health care reforms within the US Military Health System (MHS) are expected to shift >1.9 million MHS beneficiaries from military treatment facilities (MTFs) into local civilian hospitals over the next 1-2 years. The objective of this study was to examine how such health care reforms are likely to affect the quality of MHS care. DATA SOURCES Adult MHS beneficiaries, aged 18-64 years, treated in MTFs (under a program known as Direct Care) were compared against (1) MHS beneficiaries treated in locally available civilian hospitals (under a program known as Purchased Care) and (2) similarly-aged adult civilian patients across the United States. MHS beneficiaries in Direct and Purchased Care were identified from fiscal-year 2016-2018 MHS inpatient claims. National inpatients were identified in the 2017 Nationwide Readmissions Database. STUDY DESIGN Retrospective cohort. DATA COLLECTION Differences in quality were compared using two sets of quality metrics endorsed by the US Agency for Healthcare Research and Quality (AHRQ): Inpatient Quality Indicators, 19 quality metrics that look at differences in in-hospital mortality, and Patient Safety Indicators, 18 quality metrics that look at differences in in-hospital morbidity and adverse events. Among MHS beneficiaries (Direct and Purchased Care), we further simulated what changes in quality indicators might look like under various proposed scenarios of reduced access to Direct Care. PRINCIPAL FINDINGS A total of 502,252 MHS admissions from 37 MTFs and surrounding civilian hospitals were included (326,076 Direct Care, 179,176 Purchased Care). Nationwide, 9.34 million adult admissions from 2453 hospitals were included. On average, MHS beneficiaries treated in MTFs experienced better inpatient quality and improved patient safety compared with MHS beneficiaries treated in locally available civilian hospitals (e.g., summary observed-to-expected ratio for medical mortality: 0.98 vs. 1.03, p < 0.001) and adult patients across the United States (0.98 vs. 1.02, p < 0.001). Simulations of proposed changes resulted in consistently worse outcomes for MHS patients, whether reducing MTF access by 10%, 20%, or 50% nationwide; limiting MTF access to active-duty beneficiaries; or closing MTFs with the worst performance on patient safety (p < 0.001 for overall quality indicators for each). CONCLUSIONS Reducing access to MTFs could result in significant harm to MHS patients. The results underscore the importance of health-policy planning based on evidence-based evaluation and the need to consider the consequential downstream effects caused by changes in access to care.
Sustainable City Regions: Mega-Projects in Balance with the Earth’s Carrying Capacity

The issue of sustainability is becoming the basis of a massive global project for the transformation of the existing human-made environment to operate within the capacities of the natural environment. Such a project requires the balancing of resource and energy use at every scale from the scale of the individual dwelling to the scale of the globe. Imbalances in a sustainable system can persist at a given scale only when the accountability for that imbalance is negotiated with some agency at the next larger scale. The master scale for adjusting these numerous balances is the town-region, where the major balance-seeking activities required to practice sustainability will be carried out. This paper presents a design for a town-region that is well suited for the carrying out of such a balance-seeking process. The project is an entry in a competition to design a new administrative town for South Korea. This entry presents a new urban form, a MegaForm, the Sustainable Town-as-a-Hill. The Town-as-a-Hill is uniquely designed to support both the technical processes of sustainability as well as provide an urban environment that supports and is supported by strong civil society processes. The project’s processes are grounded in a principle called the Sustainable Area Budget (SAB). The SAB is an equitable, land-based budget from which, on a net basis, all the town-region’s energy and resource needs are to be met. An ongoing, participatory, multiple alternative scenario-building design process engages citizen stakeholders to negotiate how they will afford to live in an equitable, regenerative relationship with nature – that is, within the carrying capacity of their Sustainable Area Budget.
Vision and action in the language-ready brain: from mirror neurons to SemRep

The general setting for our work is to locate language perception and production within the broader context of brain mechanisms for action and perception in general, modeling brain function in terms of the competition and cooperation of schemas. Particular emphasis is placed on mirror neurons - neurons active both for execution of a certain class of actions and for recognition of a (possibly broader) class of similar actions. We build on the early VISIONS model of schema-based computer analysis of static scenes to present SemRep, a graphical representation of dynamic visual scenes designed to support the generation of varied descriptions of episodes. Mechanisms for parsing and production of sentences are currently being implemented within Template Construction Grammar (TCG), a new form of construction grammar distinguished by its use of SemRep to express semantics.
When is it safe to forgo abdominal CT in blunt-injured children?

Introduction CT is the standard modality to diagnose solid organ injury after blunt trauma; however, the associated radiation carries a risk of cancer. We hypothesized that there are patient-specific factors that can identify those children who require abdominal CT. Methods We reviewed all children admitted to 2 pediatric trauma centers after blunt trauma with liver or spleen injury from January 2009 to December 2013. The low-risk group was defined as a Glasgow Coma Scale (GCS) of 15 with normal pediatric age-adjusted shock index (heart rate/systolic blood pressure; SIPA) on presentation, and injury attributable to a single, nonmotorized, blunt force to the abdomen. The at-risk group did not meet these criteria. Results We identified 206 children with blunt liver or spleen injury, 101 of whom met the low-risk criteria. Among these 101 children who met the low-risk criteria, there were no deaths, no children required laparotomy, only 1 child required a packed red cell transfusion, and no children required discharge to a rehabilitation facility. Conclusion Children who present to the emergency department after blunt abdominal trauma by a nonmotorized force with a normal GCS and SIPA are unlikely to have a solid organ injury that will require intervention.
A study of the impact of the growing international dimensions of technology on career development at a National Aerospace Laboratory

It is pointed out that the United States leadership in the aerospace industry is being threatened by mounting global competition. The National Aeronautics and Space Administration's Langley Research Center must deal with complex issues regarding technology transfer with increasing frequency as foreign governments, venture partners, subcontractors, and suppliers force US firms to involve them in ways that require new and sophisticated technology in exchange for sharing development risk and providing a market for the product. Further career development for NASA Langley engineers being contemplated to maximize the US benefit of technology flow includes increased emphasis on technology assessment during participation in foreign travel and international conferences, enhancement of skills in foreign technology monitoring, and increased support for early career exposure to the broader industry/world view through formal training and domestic international assignments. >
Coprolites Associated with Archaeolemur Remains in North-Western Madagascar Suggest Dietary Diversity and Cave Use in a Subfossil Prosimian

Subfossil fecal pellets associated with Archaeolemur cf. edwardsi skeletal material from Anjohikely Cave in north-western Madagascar were probably derived from this large extinct lemur. Pellets were photographed, measured, and dissected. One of the pellets dates to 830 ± 60 years BP. Pellets contain a wide variety of items indicative of omnivory, including fibrous fruit exocarps and seeds; bat, rodent, frog, and lizard bone; gastropod shell; and crustacean and arthropod exoskeletons—all within a matrix of comminuted vegetation. Pollen contents from inside intact pellets support other paleoecological evidence that recent feeding had taken place in wooded grassland habitat. This diet is consistent with ethnohistorical data and anatomical studies that indicate hard-object feeding in Archaeolemur. Archaeolemur may have deliberately entered caves to forage, although caves would also have offered water, abundant shade, cool conditions, cryptic sleeping sites, and refuge from predators. Cave-exploring behavior is rare in primates, but consistent with anatomical evidence that Archaeolemur was well adapted for terrestrial locomotion as well as arboreal climbing.
Zoopharmacognosy: The Use of Medicinal Plants by Animals

The last years of the twentieth century offer both challenges and opportunities for phytochemists. The AIDS epidemic is still expanding and to date medical science has not been able to find effective treatments. Resistance to antibiotics, antimalarials, and other drugs occurs with increasing frequency. Crisis like these have created a new demand for phytochemical screening programs to detect antiviral plant products. Consequently the attention of phytochemists has turned to the tropical rain forests that contain most of the world’s species of plants and animals.
Simple Games in a Complex World: A Generative Approach to the Adoption of Norms

Uncovering the boundaries of legal rules and defining their proper limits have traditionally vexed students of the law. When must we regulate? When will behavior coalesce in an appropriate way without the intervention of law? These are big questions, as the recent explosion of norms literature makes clear. I do not try to answer these questions here. Instead, I introduce a particular approach to examining these questions, stepping beyond the formal tools that law professors often use. Applying this methodology could ultimately produce a much richer feel for the possibilities and risks in these situations.
Beyond CTLA-4 and PD-1, the Generation Z of Negative Checkpoint Regulators

In the last two years, clinical trials with blocking antibodies to the negative checkpoint regulators CTLA-4 and PD-1 have rekindled the hope for cancer immunotherapy. Multiple negative checkpoint regulators protect the host against autoimmune reactions but also restrict the ability of T cells to effectively attack tumors. Releasing these brakes has emerged as an exciting strategy for cancer treatment. Conversely, these pathways can be manipulated to achieve durable tolerance for treatment of autoimmune diseases and transplantation. In the future, treatment may involve combination therapy to target multiple cell types and stages of the adaptive immune responses. In this review, we describe the current knowledge on the recently discovered negative checkpoint regulators, future targets for immunotherapy.
Magsat scientific investigations

The Magsat spacecraft is providing the first global, vector magnetic survey. Investigations using the Magsat data are being carried out by scientists at NASA's Goddard Space Flight Center, at the U.S. Geological Survey of the Department of the Interior and by 32 selected investigators. Nineteen of the investigators are from the United States and 13 are from various foreign nations. The investigations described fall into four categories; (1) geomagnetic field modeling; (2) crustal magnetic anomaly studies; (3) investigations of the inner Earth: the core, mantle and core-mantle interface; and (4) studies of external current systems.
Application of Self-Efficacy Theory to the Transition from School to Work.

The main emphasis of school-to-work transition programs has been on having students with disabilities develop meaningful life and work skills. Typically, transition curriculums have focused on providing skill training in the following three areas: (1) employment skills; (2) independent living skills; and (3) social skills (West, 1995). However, with the primary emphasis of transition curriculum being placed on skill development, little attention has been given to the psychological factors that may be important to the success of transitioning individuals from school to work. The purpose of this article is to provide rehabilitation counselors with the necessary information and strategies to integrate Bandura's theory of self-efficacy into the transition curriculum. Specifically, this article will focus on how Bandura's four sources of efficacy information (performance accomplishments, vicarious experiences, verbal persuasion, and emotional arousal) can be used to increase the successful participation, persistence, and motivation of students with disabilities in transitioning from school to work. © 1998 Elsevier Science Ireland Ltd. All rights reserved.
Adjuvant Therapy for Positive Nodes After Induction Therapy and Resection of Esophageal Cancer

Background The value of adjuvant chemotherapy for patients with positive lymph nodes (+LNs) after induction therapy and resection of esophageal cancer is controversial. This study assesses survival benefit of adjuvant chemotherapy in this cohort. Methods We analyzed our single-institution database for patients with +LNs after induction therapy and resection of primary esophageal cancer between 2000 and 2013. Factors associated with survival were analyzed using a Cox proportional hazards model. Results A total of 101 of 764 esophagectomy patients received induction and had +LNs on final pathologic examination. Forty-five also received adjuvant therapy: 37 of 45 (82%) received chemotherapy alone, 1 of 45 (2%) received radiation alone, and 7 of 45 (16%) received both. Pathologic stage was IIB in 21 (47%), IIIA in 19 (42%), and IIIB in 5 (11%). In 56 node-positive patients with induction but not adjuvant therapy, pathologic stage was IIB in 28 (50%), IIIA in 18 (32%), IIIB in 7 (13%), and IIIC in 3 (5%). Neither age nor comorbidity score differed between cohorts. Adjuvant patients experienced a shorter hospital length of stay (mean, 10 days [range, 6 to 33 days] versus 11 days [range, 7 to 67 days]; p = 0.03]. Median survival favored the adjuvant group: 24.0 months (95% confidence interval, 16.6 to 32.2 months) versus 18.0 months (95% confidence interval, 11.1 to 25.0 months); p = 0.033). Multivariate Cox regression identified adjuvant therapy, length of stay, and number of +LNs as influential for survival. Conclusions Optimal management of node-positive patients after induction therapy and esophagectomy remains unclear, but in this series, adjuvant therapy, length of stay, and number of +LNs impacted survival. A prospective trial may reduce potential bias and guide the evaluation of adjuvant therapy in this patient population.
Emergency department screening for syphilis in pregnant women without prenatal care

Study objective: To determine if there is a high seroprevalence of syphilis in pregnant women without prenatal care presenting to an urban emergency department. Design: Prospective, nonblinded sampling of pregnant women without prenatal care with a comparison group of pregnant women with prenatal care from the obstetrics clinic. Patients in the ED setting were asked about such associated risk factors as previous syphilis and drug use. Setting: Urban ED. Type of participants: Pregnant women without prenatal care. Intervention: Patients were screened for syphilis using the automated reagin test. Reactive automated reagin tests were confirmed by the fluorescent treponemal antibody absorption. In addition, 44 patients with nonreactive automated reagin tests had confirmatory tests done. New cases were verified by the state health department. Measurements and main results: Seventy-two patients were included in the study. The average age was 25 years. Eight patients (11.1%) were diagnosed with previously undetected syphilis. Four patients (5.6%) had previously treated syphilis. The laboratory cost of screening was $248 per new case of syphilis detected. The study group was compared with 118 patients matched for age and race who presented to the obstetrics clinic for routine prenatal care. Two new cases of syphilis were discovered in the clinic population (1.7%). Conclusion: A high rate of syphilis infection was detected in this inner-city ED population presenting without prenatal care. This was higher than that found in the patients presenting for obstetrics care in the clinic. Patients can be screened effectively in the ED.
Green functions of vortex operators

Abstract We study the euclidean Green functions of the 't Hooft vortex operator, primarily for abelian gauge theories. The operator is written in terms of elementary fields, with emphasis on a form in which it appears as the exponential of a surface integral. We explore the requirement that the Green functions depend only on the boundary of this surface. The Dirac veto problem appears in a new guise. We present a two-dimensional “solvable model” of a Dirac string, which suggests a new solution of the veto problem. The renormalization of the Green functions of the abelian Wilson loop and abelian vortex operator is studied with the aid of the operator product expansion. In each case, an overall multiplication of the operator makes all Green functions finite; a surprising cancellation of divergences occurs with the vortex operator. We present a brief discussion of the relation between the nature of the vacuum and the cluster properties of the Green functions of the Wilson and vortex operators, for a general gauge theory. The surface-like cluster property of the vortex operator in an abelian Higgs theory is explored in more detail.
Physiotherapists' perceptions and use of medical imaging information in practice.

Background and Purpose. Physiotherapists must take responsibility for all aspects of patient care. Information from medical imaging studies can influence clinical decisions. The purpose of the present study was to gather information about physiotherapists' perceptions and use of medical imaging information in clinical practice. Method. A survey questionnaire was developed, validated and pilot tested. Subjects were randomly selected from a pool of licensed physiotherapists practising in four California Physical Therapy Association Districts. The survey was sent to 500 physiotherapists. Data gathered from the survey were transcribed to spreadsheets for analysis. Results. One hundred and twenty participants completed and returned the survey. Information from radiographs was most frequently available, followed by MRI and CT scan information, respectively. Respondents reported more use of information from reports than from images. Respondents also indicated that it was important to be able to review medical imaging information (70%), that they use medical imaging information in their practice when it is available (83.4%), that physiotherapists have the necessary knowledge and skills to use this type of information (77.3%), and that medical imaging should be covered in entry-level educational programmes (84.2%). Respondents additionally indicated that medical imaging information could be used to understand a patient's disease process (85%), improve communication about patient care (90%), improve diagnosis, prognosis and interventions for patients (81.6%), and identify contraindications to examination and interventions (87.5%). Conclusions. Physiotherapists have access to some medical imaging information and perceive that this information could be valuable in patient care; however, not all therapists are confident in their ability to interpret this information. Curricula in entry-level physiotherapist educational programmes should include information about medical imaging. Copyright © 2006 John Wiley & Sons, Ltd.
The LCROSS Cratering Experiment

As its detached upper-stage launch vehicle collided with the surface, instruments on the trailing Lunar Crater Observation and Sensing Satellite (LCROSS) Shepherding Spacecraft monitored the impact and ejecta. The faint impact flash in visible wavelengths and thermal signature imaged in the mid-infrared together indicate a low-density surface layer. The evolving spectra reveal not only OH within sunlit ejecta but also other volatile species. As the Shepherding Spacecraft approached the surface, it imaged a 25- to-30-meter-diameter crater and evidence of a high-angle ballistic ejecta plume still in the process of returning to the surface--an evolution attributed to the nature of the impactor.
U-Th-Pb systematics in lunar highland samples from the Luna 20 and Apollo 16 missions

Abstract Luna 20 and Apollo 16 soils which represent two highland sites contain Pb which has206Pb/204Pb of from 53 to 277 andradiogenic207Pb/206Pb of from 0.78 to 0.83. The soils yield very discordant ages which range from 4.91 up to 6.08 AE. A few of the results on soils can be discussed in terms of a simple two-stage model in which the lunar crust is generated by the addition of magmatic material enriched in Pb relative to both U and Th (without U-Th fractionation). The fractionation factor (Pb/U)magma/(Pb/U)source is commonly ∼ 2.5 or more. In no way can the soil model ages give a direct determination of the age of the Moon. The highland anorthosite 60025 gave a Pb concentration of 6.9 ppb and appears distinctly radiogenic with206Pb/204Pb= 25.4. The207Pb-206Pb age is 6.64 AE but the U concentration of 0.79 ppb is sufficient to account for the radiogenic Pb. This result is distinctly different from ancient and highly radiogenic initial Pb in 14310, 14053 and 15415. The extent to which various rock types ofdifferent ages and undetermined exotic materials contribute unsupported initial Pb to lunar soil is not yet established. The complexity of the Pb-U-Th data on the soils is remarkable in comparison with the simple behavior of the Rb-Sr results.
The secular behavior of aggregate retirement flows

This paper has presented estimated time-series of retirement flows from the labor force for men and women aged 55–64 and 65 and over. These results are a useful addition to labor force participation rates as a means of studying secular trends of aggregate labor market behavior of older workers. Because retirement rates are independent of people who have not been in the labor force, they are better suited to secular studies of aggregate retirement behavior than are labor force participation rates.
Sets with few Intersection Numbers from Singer Subgroup Orbits

Using a Singer cycle in Desarguesian planes of order q? 1(mod3), q a prime power, Brouwer 2 gave a construction of sets such that every line of the plane meets them in one of three possible intersection sizes. These intersection sizes x, y, and z satisfy the system of equationsformulaBrouwer claimed that this system has a unique solution in integers. Further, Brouwer noted that for q a perfect square, this system has a solution for which two of the variables are equal, ostensibly implying that when q is a square the constructed set has only two intersection numbers. In this paper, we perform a detailed analysis which shows that this system does not in general have a unique solution. In particular, the constructed sets when q is a square might have three intersection numbers. The cases for which this occurs are completely determined.
The Expected Number of Visits to State k before a Total System Failure of a Complex System with Repair Maintenance

This paper investigates the stochastic behavior before a total system failure for a standby redundant system with repair maintenance. It derives the expected number of visits to state k before a total system failure and other measures explicitly by considering "taboo" probabilities for an imbedded Markov chain generated by the system. The transition probabilities and the first-passage distributions are also discussed. Numerical examples are presented.
Improved assays for the assessment of ϰ- and δ-properties of opioid ligands

Abstract The highly selective non-equilibrium μ-antagonist β-funaltrexamine (β-FNA) produced a maximal 20-fold shift in the IC 50 for the μ-agonist morphine on the guinea-pig ileum preparation, whilst producing no significant change in the IC 50 for the ϰ-agonist ethylketazocine. On preparations pretreated with β-FNA, the pA 2 values for the interaction of morphine and ethylketazocine with naloxone were similar. These values were similar to the pA 2 value for the interaction of ethylketazocine and naloxone determined on control tissues, but significantly different from the pA 2 value for morphine-naloxone on control tissues, indicating that the agonist actions of morphine on preparations pretreated with high concentrationsof β-FNA are mediated by ϰ-, rather than μ-receptor interaction. On the mouse was deferens preparation, co-incubation with the highly selective δ-agonist Tyr-D-Ser-Gly-Phe-Leu-Thr (DSLET) and the non-selective non-equilibrium opiate antagonist β-chlornaltrexamine (β-CNA) resulted in marked inhibition of the agonist actions of morphine but had no effect upon the agonist actions of the δ-agonist leucine-enkephalin. The pA 2 values for the interactions of naloxone with leucine-enkephalin and etorphine were unaltered by pretreatment with β-CNA and DSLET. In similarly pretreated tissues, the agonist actions of ethylketazocine were markedly inhibited. It is concluded that manipulation of the guinea-pig ileum and mouse vas deferens preparations in the described manner results in assay systems that possess a largely homogeneous receptor population, and as such are valuable tools with which to evaluate opioid activity.
Velocity dispersions of low luminosity ellipticals - L approximately equal to sigma-cubed

A complete sample of elliptical galaxies in the core of the Virgo cluster is used to derive a relation between stellar velocity dispersion and luminosity. L is found to approximately equal sigma to the nth power, where n = 3.2 + or - 0.2 over two decades of luminosity, with a scatter of 0.38 mag. The possibility of curvature in the relation or rotational support of the galaxies is examined, and a derivation of a law of slope 3 is presented and compared with the derivation for a slope of 4. It is concluded that the lack of increased scatter as the points deviate from a slope of 4 implies that rotation is not important.
X-ray edge singularities of relaxed-out bound states and relaxed-in band states☆

Abstract Anomalous X-ray edge singularity exponents are obtained in the two cases of (i) relaxed-out bound states and (ii) relaxed-in band states, where the number of conduction band states is changed, and simple phase-shift arguments are given which consistently explain all the exponents.
A cotyledon screen for resistance to scab (Cladosporium cucumerinum) in cucumber (Cucumis sativus) seedlings

Summary An efficient protocol for differentiating cucumber (Cucumis sativus) seedlings resistant and susceptible to scab (Cladosporium cucumerinum) has been developed by examining the interacting factors of spore density and cotyledon growth stage. The procedure permitted both resistant and susceptible plants to be recovered. Seedlings were grown at 20°C and inoculated 1 day after emergence by placing a 5 μl inoculum droplet (2 × 106 spores/ml) on the newly expanded cotyledons. Seedlings were incubated in a darkened dew chamber for 48 h at 20°C and 100% r.h., and then grown for 6 days at 20°C. Plants could be rated as resistant or susceptible 8 days after inoculation.
The evolution of understanding: Positioning evaluation within a comprehensive performance management system

Although performance management has become a common organizational practice, in many cases it has not resulted in substantial program improvement or organizational learning. The author discusses two issues related to performance management systems that are of key concern to evaluators: (a) evaluation is often excluded from these systems in favor of monitoring data, and (b) performance management systems tend to focus on the creation of data rather than its use. The author discusses the complementary roles of evaluation and monitoring data, and highlights some ways in which evaluation can help improve performance management systems. © Wiley Periodicals, Inc., and the American Evaluation Association
A SIMPLE WAY TO UNDERSTAND THE ELECTRONIC STRUCTURES OF THE Tl–Ba–Ca–Cu–O HIGH Tc SUPERCONDUCTORS

The extended Huckel tight-binding method is used to analyze the electronic structures of two families of superconductors, TlBa2Can−1CunO2n+3 and Tl2Ba2Can−1CunO2n+4. Three members from each family are examined. All of them appear to be conductors with σ antibonding half-filled bands crossing the Fermi levels. The band structures suggest that the oxidation states of Cu and Tl are around +2 and +3, respectively. The calcium and barium atoms, apart from acting as electron donors, have little effect on the dispersion of the bands near the Fermi level. However, the calcium atoms do produce a small splitting of the half-filled bands. One of the proposed superconducting mechanisms, involving oxidation of Cu2+ by Tl3+ is discussed. So is the role of vacancies. If there is an oxygen vacancy in TlBa2Ca3Cu4O11, it should prefer the equatorial or basal position in the Cu-O layer. The oxygen-oxygen repulsions may play a crucial role in determining the unit cell parameters.
Diapause in monogonont rotifers

This review focuses on more recent findings on the diapause in Monogonont rotifers, since the major reviews by Pourriot & Snell (1983, Hydrobiologia 104: 213–224) and Gilbert (1992, Rotifera. In Adiyodi, K. G. & R. G. Adiyodi (eds), Reproductive Biology of Invertebrates, Vol. 5 – Sexual Differentiation and Behaviour. IBH Publishing Co., Oxford: 115–136; Vol. 6A – Asexual Propagation and Reproductive Strategies. IBH Publishing Co., Oxford: 231–263.). It covers diapausing egg formation, diapausing egg survival, and diapausing egg hatching as well as possible strategies involved in these processes. Data from laboratory and field studies exist, but little information is available on diapausing egg hatching in the field. Resting or diapausing egg production can be mictic and in some cases amictic. Mictic diapausing egg production depends on the balance between cues promoting and inhibiting mictic female production. Such cues can be either environmental or endogenous. Our knowledge on factors inducing mixis is still limited to a few species, but effects of crowding on mixis induction may be more widespread. Recent results also show that male mating behavior may play an important role in the successful production of diapausing eggs. Hatching may be induced by factors related to temperature and light conditions; also desiccation may have a role. However, desiccation of temporary habitats may also be damaging to diapausing stages. Although few data are available, those existing point to distinct differences between populations and the importance of clonal variation within populations regarding the initiation as well as the termination of diapause.
Alternative schemes of butyrate production in Butyrivibrio fibrisolvens and their relationship to acetate utilization, lactate production, and phylogeny

Butyrivibrio fibrisolvens strains D1 and A38 produced little lactate, but strain 49 converted as much as 75% of its glucose to lactate. Strain 49 had tenfold more lactate dehydrogenase activity than strains D1 or A38, this activity was stimulated by fructose 1,6-bisphosphate, and had a pH optimum of 6.25. A role for fructose 1,6-bisphosphate or pH regulation of lactate production in strain 49 was, however, contradicted by the observations that very low concentrations (< 0.2 mM) of fructose 1,6-bisphosphate gave maximal activity, and continuous cultures did not produce additional lactate when the pH was decreased. The lactate production of strain 49 was clearly inhibited by the presence of acetate in the growth medium. When strain 49 was supplemented with as little as 5 mM acetate, lactate production decreased dramatically, and most of the glucose was converted to butyrate. Strain 49 did not possess butyrate kinase activity, but it had a butyryl-CoA/acetate CoA transferase that converted butyryl-CoA directly to butyrate, using acetate as an acceptor. The transferase had a low affinity for acetate (Km of 5 mM), and this characteristic explained the acetate stimulation of growth and butyrate formation. Strains D1 and A38 had butyrate kinase but not butyryl-CoA/acetate CoA transferase, and it appeared that this difference could explain the lack of acetate stimulation and lactate production. Based on these results, it is unlikely that B. fibrisolvens would ever contribute significantly to the pool of ruminal lactate. Since relatives of strain 49 (strains Nor37, PI-7, VV1, and OB156, based on 16S rRNA sequence analysis) all had the same method of butyrate production, it appeared that butyryl-CoA/acetate CoA transferase might be a phylogenetic characteristic. We obtained a culture of strain B835 (NCDO 2398) that produced large amounts of lactate and had butyryl-CoA/acetate CoA transferase activity, but this strain had previously been grouped with strains A38 and D1 based on 16S rRNA sequence analysis. Our strain B835 had a 16S rRNA sequence unique from the one currently deposited in GenBank, and had high sequence similarity with strains 49 and Nor37 rather than with strains A38 or D1.
Global inorganic source of atmospheric bromine.

A few bromine molecules per trillion (ppt) causes the complete destruction of ozone in the lower troposphere during polar spring and about half of the losses associated with the “ozone hole” in the stratosphere. Recent field and aerial measurements of the proxy BrO in the free troposphere suggest an even more pervasive global role for bromine. Models, which quantify ozone trends by assuming atmospheric inorganic bromine (Bry) stems exclusively from long-lived bromoalkane gases, significantly underpredict BrO measurements. This discrepancy effectively implies a ubiquitous tropospheric background level of ∼4 ppt Bry of unknown origin. Here, we report that I- efficiently catalyzes the oxidation of Br- and Cl- in aqueous nanodroplets exposed to ozone, the everpresent atmospheric oxidizer, under conditions resembling those encountered in marine aerosols. Br- and Cl-, which are rather unreactive toward O3 and were previously deemed unlikely direct precursors of atmospheric halogens, are readily converted into I...
Flame temperature measurements by spectral remote sensing

Abstract The usefulness of spectral emission measurements in determining line-of-sight temperature and/or concentration distributions in high temperature gaseous systems is investigated. An analytical model was constructed which relates the emitted spectral intensity to the local temperature and radiating species concentration within the gas. The mathematical statement of the model leads to a series of integral equations, one for each frquency at which data are taken. The profiles within the gas are determined by inverting these integral equations through the use of a parameter estimation inversion technique. Analytical experiments performed indicate that parameter estimation is a workable approach to the inversion problem. For the case of temperature determination, random error in emission data and errors in an assumed concentration distribution were deamplified in the final result. In analogous studies for concentration, errors in input data were not reduced in the determined profile. The technique is applied in an experimental system using a flat laminar CH 4 air diffusion flame. In the heated gas envelope produced by the flame, temperatures varied from ambient to about 2000 K in less than 1 cm. Carbon dioxide could be added to the flame to provide a wider range of optical thicknesses. For the case where spectral data points were available at which the flame was not optically thin, the temperature distribution in the region above 1000 K was determined within the accuracy of the independent thermocouple probe measurement (with emission data taken from both sides of the flame and approximating the concentration profile based on gas sampling). When CO2 was not added to the flame, the reduced information content in the spectral measurements resulted in poorer temperature results.
The anomalous diffusion of meteor trails

Radars frequently detect meteor trails created by the ablation of micro-meteoroids between 70 and 120 km altitude in the atmosphere. Plasma simulations show that density gradients at the edges of meteor trails drive gradient-drift instabilities which develop into waves with perturbed electric fields often exceeding hundreds of mV/m. These waves create an anomalous cross-field diffusion that can exceed the cross-field (⟂ B) ambipolar diffusion by an order of magnitude. The characteristics of the instabilities and anomalous diffusion depend on the trail altitude, latitude, and density gradient. A simple relation defines the minimum altitude at which meteor trail density gradients drive plasma instabilities and anomalous diffusion. These results impact a number of meteor radar studies, including those that use diffusion rates to determine trail altitude, and atmospheric temperature.
Prediction of material erosion and lifetime during major plasma instabilities in tokamak devices

Abstract Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the tokamak reactor concept. The deposited plasma energy during major disruptions, edge-localized modes (ELMs), and vertical displacement events (VDEs) causes significant surface erosion, possible structural failure, and frequent plasma contamination. Surface damage consists of vaporization, spallation, and liquid splatter of metallic materials. Structural damage includes large temperature increases and high thermal stresses in structural materials and at the interfaces between surface coatings and structural members. To evaluate the lifetimes of plasma-facing materials and nearby components and to predict the various forms of damage that they experience, comprehensive models (contained in the heights computer simulation package) are developed, integrated self-consistently, and enhanced. Splashing mechanisms such as bubble boiling and various liquid magnetohydrodynamic (MHD) instabilities and brittle destruction mechanisms of nonmelting materials can be serious erosion mechanisms and are being studied in detail. The ejected macroscopic particles (MPs) will interact with incoming plasma particles and with the vapor cloud above the surface. Therefore, the dynamic behavior of MPs in the vapor cloud and their influence on total erosion rate is important. Results of self-consistent MHD calculations are presented in which the dynamics of both the vapor cloud and MP interaction are coupled with incoming plasma ions and electrons from the scrape-off layer during a disruption. The design requirements and implications of plasma facing and nearby components are discussed, along with recommendations to mitigate and reduce the effects of plasma instabilities on reactor components.
Slowing and stopping photons using backward frequency conversion in quasi-phase-matched waveguides

A tunable scheme for slowing down and stopping light using the backward frequency conversion in the quasi-phase-matched waveguides is proposed. It is shown that delay time ranging from a nanosecond to hundreds of microseconds can be obtained in few-centimeter-long GaAs-based structures with up to ten GHz bandwidths at moderate (few W) peak powers of coupling light. The proposed scheme also allows one to continuously change the frequency of the signal.
Avian cardiac tropomyosin gene produces tissue-specific isoforms through alternative RNA splicing

We have isolated a quail cardiac tropomyosin gene which encodes three distinct isoforms through the use of alternative exon splicing. Characterization of cDNA clones produced by this gene indicate that the gene encodes a unique 284 amino acid cardiac tropomyosin isoform, along with a 248 amino acid cytoskeletal and 284 amino acid smooth muscle isoforms. Northern analyses indicate that the gene is primarily expressed in cardiac muscle, with only minor expression of the cytoskeletal and smooth muscle transcripts.
Residual-stress determination by single-axis holographic interferometry and hole drilling—Part I: Theory

A method is described for the rapid, accurate determination of residual stresses from a holographic interference fringe pattern. The pattern is generated by the displacement field caused by localized relief of residual stresses via the introduction of a small, shallow hole into the surface of a component or test specimen. The theoretical development of the holographic method is summarized. An example is given showing how the method can be applied to a typical experimentally observed fringe pattern to determine principal residual stresses and directions.
Evaluation technology in instructional development

The instructional development model described in this paper was deliberately constructed to eliminate the boxes and arrows commonly used to illustrate how development works. Many of my colleagues and training associates view this as a maturing of the field. Just as computer scientists have all but eliminated the flowchart from the programing process—a result caused by sophistication of ideas and operations—so instructional developers are establishing conceptual systems that cannot simply be reduced to several boxes with connecting lines and arrows. A well-organized development system would be too complex to diagram, and if it were diagramed, no one could follow it.
Computationalism and the problem of other minds

Abstract In this paper I discuss Searle's claim that the computational properties of a system could never cause a system to be conscious. In the first section of the paper I argue that Searle is correct that, even if a system both behaves in a way that is characteristic of conscious agents (like ourselves) and has a computational structure similar to those agents, one cannot be certain that that system is conscious. On the other hand, I suggest that Searle's intuition that it is “empirically absurd” that such a system could be conscious is unfounded. In the second section I show that Searle's attempt to show that a system's computational states could not possibly cause it to be conscious is based upon an erroneous distinction between computational and physical properties. On the basis of these two arguments, I conclude that, supposing that the behavior of conscious agents can be explained in terms of their computational properties, we have good reason to suppose that a system having computational properti...
Precision alignment and assembly of a Fourier transform microspectrometer

Integrating optics with MEMS presents numerous challenges in assembly and joining of heterogeneous components, stringent alignment of parts, packaging of the device to protect it, etc. Microspectrometers are examples of MOEMS devices where these issues play a significant role to the performance of the device. The motivation behind miniaturization of the spectrometer is strong, because traditional spectrometers are table-top instruments, and they are generally too large, and too costly to be ported outside of lab environments. Micro-Electro-Mechanical-Systems (MEMS) technology combined with microassembly offers promising possibilities to achieve compact and cost-effective miniaturization in such instruments. In this paper, we present a fiber-coupled Fourier-Transform microspectrometer with a nominal size of 3cmx3cmx3cm, constructed using 3D hybrid microassembly and targeting wavelengths in the visible and NIR spectra. We use modular micro scale parts, including minimum energy compliant MEMS fasteners to configure a die-sized microoptical bench. Light coupling, miniature electronics and power are included in a spectrometer package. In order to achieve the required precision on the microoptical bench we employ automated assembly of microcomponents. We present a systematic two-step assembly & alignment scheme (coarse and fine) using an image-based spot Jacobian algorithm. In this paper we present details related to design, tolerance analysis, calibration, microassembly and visual servoing techniques as well as spectrum data recovery for a completed prototype.
Turbidimetric studies of the in vitro assembly and disassembly of porcine neurotubules.

Abstract Turbidity measurements have been used to study the in vitro assembly and disassembly of porcine neurotubules. All measurements were carried out with tubulin with a purity higher than 80%. Tubules formed by in vitro assembly of this protein are so long that the turbidity is insensitive to length and is a function only of the total mass of high molecular weight material. Porcine tubulin shows a critical concentration for assembly of about 0.2 mg/ml under optimal conditions, pH 6.6, 0.1 m -2-( N -morpholino)ethane sulfonic acid, 26 to 37 °C. Under these conditions assembly and disassembly are essentially fully reversible in the presence of excess GTP. The kinetics of assembly show an initial lag and initial rates which are strongly temperature dependent. Our samples show a concentration dependence of no more than second order. The apparent activation enthalpy of assembly is 25 kcal/mol; the apparent reaction enthalpy of assembly for the chain propagation step is 21 kcal/mol. Disassembly kinetics show an apparent negative activation enthalpy of −28 kcal/mol. They are independent of tubule length implying a slow activation step followed by rapid depolymerization. At 20 °C, cycles of polymerization and depolymerization show hysteresis effects in the assembly kinetics though not in disassembly rates or final states. This is most easily explained by postulating a slow reversible inactivation at 4 °C of the initiation complex for tubule assembly. Conditions are reported for producing tubulin in a state which cannot assemble in aqueous buffer unless nucleotides are added. GTP, ATP and ADP, but not GDP, are effective in promoting tubule assembly. An adenylate kinase impurity in our preparation may be the cause of this unusual effect. Whether or not it is actually associated with tubulin or tubules is unknown.