cssi/SciSciGPT-SciSciNet huggingface dataset:
The Conceptual Speed-Bump: Losing Potential STEM Students in the Transition From Elementary School to Middle School

Many educators in the science, technology, engineering and math (STEM) disciplines hope to improve the number of students interested in and prepared for these more difficult disciplines through innovative teaching, demonstrations and hosted camps. Research has shown that motivation is a much smaller part of the issue; student learning outcomes are much more sensitive to fundamental academic ability. Current curriculum design fails most students miserably in helping them bridge the gap from concrete learning to abstract thought and understanding in the middle school years. Thus, they are ill-prepared to engage in the more advanced learning required to pursue the STEM disciplines, a result that no amount of innovative teaching can correct. This paper will review the performance data from industrial nations at the 4th Grade and 8th Grade levels and illustrate curriculum differences between industrial countries producing higher percentages of STEM graduates. Examination of the performance effects of many variables, including number and sequencing of topics studied, time spent on homework, teacher credentials, access to technology, class size and dollars allocated per student, yields some surprising results. The problem is not as sensitive to many of these variables as one might expect. However, the variables that seem to provide promise for significant improvement from the current state of STEM education are related to topic coverage and manner of presentation. Final recommendations include reduction in the number of topics introduced in any given year with a corresponding reorganization of the curricula, to allow STEM teachers in the middle school to focus on the transitional learning that must occur to prepare for more advanced studies.© 2010 ASME
Micromechanical modeling of softening behavior in steel fiber reinforced cementitious composites

Abstract The fracture of cementitious materials is governed by its softening behavior. When steel fibers are incorporated into concrete to improve its toughness, the softening behavior can be predicted in terms of the composite micro-parameters including the properties of fiber, matrix and interface as well as fiber size, length, distribution and volume fraction. In this paper, the bridging force provided by a steel fiber at any arbitrary angle to the crack is first modeled in terms of the micro-parameters. For a given fiber distribution, the averaged crack bridging force is then derived and employed to obtain the composite softening behavior. The model is verified at both the microscopic and macroscopic levels with experimental results from the fiber pull-out test and the four-point beam bending test. With the model, numerical simulations are carried out to study the effect of various parameters on the tensile softening behavior. These simulations can facilitate the choice of micro-parameters for the most cost-effective material design.
Towards 40% efficiency with BMEP exceeding 30 bar in directly injected, turbocharged, spark ignition ethanol engines

Abstract Current flexi fuel gasoline and ethanol engines have efficiencies generally lower than dedicated gasoline engines. Considering ethanol has a few advantages with reference to gasoline, namely the higher octane number and the larger heat of vaporization, the paper explores the potentials of dedicated pure ethanol engines using the most advanced techniques available for gasoline engines, specifically direct injection, turbo charging and variable valve actuation. Computations are performed with state-of-the-art, well validated, engine and vehicle performance simulations packages, generally accepted to produce accurate results when targeting major trends in engine developments. The higher compression ratio and the higher boost permitted by ethanol allows larger than gasoline top engine brake thermal efficiencies and peak power and torque, while the variable valve actuation produces smaller penalties in efficiency changing the load than in conventional throttle controlled engines.
Critical Assessment of Issues Applicable to Development of Antimicrobial Susceptibility Testing Breakpoints

Antimicrobial susceptibility testing (AST) interpretive criteria (breakpoints and cutoffs) serve to translate numerical data (zones of inhibition and MIC values) into textual categories that provide direction to clinicians as to whether a microbial isolate is likely to respond to a given antibiotic
Laparoscopic conversion of failed gastric bypass to duodenal switch: technical considerations and preliminary outcomes

Abstract Background Weight loss failure after Roux-en-Y gastric bypass (RYGB) is a challenging problem facing bariatric surgeons today. Conversion from RYGB to biliopancreatic diversion with duodenal switch (BPD-DS) might provide the most durable weight loss of all revision procedures currently available. Revision to BPD-DS can be done laparoscopically in 1 or 2 stages and involves 4 anastomoses: gastrogastrostomy, duodenoileostomy, ileoileostomy, and jejunojejunostomy (to reconnect the old Roux limb). This study reports on our early outcomes after laparoscopic conversion from RYGB to BPD-DS. Methods The data from all patients undergoing conversion from failed RYGB to BPD-DS were retrospectively reviewed. The data analyzed included age, body mass index, excess weight loss, method of gastrogastrostomy, and morbidity/mortality. Results Twelve patients were identified for analysis. The mean age and body mass index before conversion was 41 years and 41 kg/m 2 , respectively. Of these 12 patients, 4 (33%) had undergone revision surgery (lengthening of the Roux limb, resizing the gastric pouch, adjustable band on pouch, or distal gastric bypass) before conversion; 8 (66%) had obesity-related co-morbidities; 7 (58%) underwent conversion to BPD-DS in 1 stage. Most gastrogastrostomies were performed using the 25-mm circular stapler. No patient died and no leaks developed. One patient required laparotomy, and 4 developed stricture at the gastrogastrostomy. The patients lost a dramatic amount of weight after conversion to BPD-DS, with a mean body mass index and excess weight loss of 31 kg/m 2 and 63%, respectively, at 11 months postoperatively. All co-morbidities resolved completely with the weight loss. Conclusion Our preliminary results indicate that laparoscopic conversion to BPD-DS from failed RYGB is highly effective with an acceptable morbidity. Using a linear stapler to construct the gastrogastrostomy might reduce the stricture rate.
The Dynamic Impacts of State Revenue Capacity on Highway Investment

This study investigates the short-term effects of state-highway EARs (EARs) and federal-grant expenditure on present-year state revenue sources and highway investment, when another state-highway source, general revenue, is controlled for. In the dynamic framework, this article argues that general revenue interacts with highway EAR and federal-grant reimbursements since these revenue sources are substitutable. The results from the panel vector auto regression (PVAR) indicate that (a) EAR and federal grants are inversely related to general revenues used in highway programs, (b) when controlled for simultaneity, autocorrelation, and omitted-variable bias, EAR and federal grants are not significant for state-investment decisions, and (c) general revenue inversely relates to state investment because there is competition for public resources between highway and general-revenue programs. Language: en
Monoclonal anti-K14 and anti-K2.

. Mouse hybridoma clones have produced monoclonal antibodies directed against the K:14 and K:2 high-incidence antigens of the Kell blood group system. Two examples of anti-K14 were isolated, each arising from a separate fusion procedure. All three monoclonal antibodies are of the immunoglobulin class IgGl. Serological activity is consistent with that seen with human antibodies to high-incidence Kell system antigens, and their epitopes are destroyed, as usual, by 2-aminoethylisothiuronium bromide treatment. Specificity was further confirmed by adsorption and elution studies. Tests against nonhuman primate red cells demonstrated the expression of K:14 only by the great apes, whereas K:2 was present on all red cells tested. These findings emphasize the usefulness of monoclonal antibodies to elucidate the evolutionary patterns of blood group variants.
Can glomerulosclerosis be reversed

Even advanced sclerotic glomeruli show ongoing cell turnover, indicating that there is potential for modulation of the progressive renal scarring seen in chronic kidney disease. Agnes Fogo examines the mechanisms of glomerulosclerosis, with a particular focus on the pivotal role of angiotensin, and considers the potential reversibility of the processes involved.
Thrombotic Potential of a Prosthetic Vein Valve

Over seven million Americans suffer from chronic venous insufficiency, secondary to valvular dysfunction, with few effective clinical therapies. Chronic Venous Insufficiency (CVI) is a painful and debilitating disease that affects the superficial and deep veins of the legs. After deep venous thrombosis, the vein valves leaflets become adherent, fold over, or are absorbed into the vein wall. Incompetent valves allow reflux and subsequent pooling of blood in the legs. The resultant CVI causes severe leg edema, skin breakdown, and possible gangrene. Current clinical therapies are only modestly effective and include vein stripping and ligation, valvuloplasty, vein valve transposition, and vein valve transplantation. Valvuloplasty is the most definitive of CVI treatment, though this surgical treatment is rarely performed due to its difficulty. The quest for a better solution continues.Copyright © 2007 by ASME
Stable reinforcement learning with recurrent neural networks

In this paper, we present a technique for ensuring the stability of a large class of adaptively controlled systems. We combine IQC models of both the controlled system and the controller with a method of filtering control parameter updates to ensure stable behavior of the controlled system under adaptation of the controller. We present a specific application to a system that uses recurrent neural networks adapted via reinforcement learning techniques. The work presented extends earlier works on stable reinforcement learning with neural networks. Specifically, we apply an improved IQC analysis for RNNs with time-varying weights and evaluate the approach on more complex control system.
Student perceptions of questionable personal selling practices

This paper reports the findings of a study which identify student ethical evaluation of questionable yet common personal selling practices. The results suggest generally that students' perceptions may not be as negative toward personal selling as reported in earlier studies dealing with perceptions of business generally. There are, however, differences in student perceptions between business and nonbusiness students suggesting that course of study, curriculum and exposure to professors may have an effect on ethical perceptions. Differences between male and female students are also reported.
Polysomnography in hypnic headache syndrome.

Hypnic headache syndrome is an unusual chronic headache that usually begins after age 60 years and occurs exclusively during sleep. Despite the relationship between the headache and sleep, no formal sleep evaluation with overnight polysomnography has been reported for this syndrome. Three patients with long-standing hypnic headache underwent overnight polysomnography. The results were quite variable, ranging from normal to marked sleep insufficiency. A hypnic headache was captured in one patient arising out of rapid eye movement sleep at a time of severe oxygen desaturation. Formal sleep evaluation should be considered in patients with hypnic headache because there may be pathophysiologic and therapeutic implications.
Pathogenicity of Geographic Isolates of Fusarium oxysporum from Crucifers on a Differential Set of Crucifer Seedlings

Pathogenicity tests with 103 isolates of Fusarium oxysporum from crucifers worldwide were conducted using a standard set of six differential crucifer cultivars. Based on their reaction to the standard differentials, all isolates could be grouped into the five major pathotypes in the three formae speciales, f. sp. conglutinans. f. sp. raphani and f. sp. matthioli. When two additional crucifers, Brassica nigra and B. campestris were added to the differe, ntial set, and the reactions of the host differentials were analyzed, an increased range of virulence profiles was observed, implying the existence of more virulence factors in the F. oxysporum population. An isolate from the U.S.S.R., was identified with virulence capable of overcoming dominant monogenic “type A” resistance in Brassica oleracea suggestive of a potentially new location for this pathotype.
Heat Transfer and Friction in Channels With Very High Blockage 45° Staggered Turbulators

Heat transfer and friction coefficients have been measured within a rectangular passage of aspect ratio 0.4 containing 45-degree staggered turbulators of very high blockage. Using a constant pitch-to-height ratio of 10 for all geometries, turbulator height-to-channel hydraulic diameter ratios from 0.193 to 0.333 were investigated. This range of e/D creates actual channel blockage ratios e/H from 0.275 to 0.475, presenting significant flow area restrictions. A liquid crystal test technique is used to obtain both detailed heat transfer behavior on the surfaces between turbulators, as well as averaged fully developed heat transfer coefficients. Reynolds numbers from 20000 to 100000 were tested. Nusselt number enhancements of up to 3.6 were obtained over that of a smooth channel, with friction coefficient enhancements of as much as 65. In contrast to low-blockage turbulated channels, the 45-degree turbulated Nu is found to be lower than that at 90-degree orientation, given very similar e/D and e/H values.Copyright © 2003 by ASME
The Discourse of Computer‐Assisted Language Learning: Toward a Context for Descriptive Research

Understanding how the speed, power, and flexibility of computers can facilitate second language acquisition is an intriguing challenge faced by instructors, researchers, and theorists. Progress in this area, however, does not appear to be forthcoming from current research on computer-assisted language learning (CALL), which suffers from the same limitations as early research on classroom instruction: Little detail is provided to describe the interaction among participants during instruction (Long, 1980). Moreover, descriptions of CALL activities included in reported research are not empirically based: They fail to describe what subjects actually do while working with CALL. A third problem is that the terms used to describe CALL activities have been developed specifically for that purpose, and are therefore not comparable to those used for classroom activities. At the same time, these descriptors are not sufficiently uniform and formally stated to allow specific comparisons among CALL activities. Toward a solution to these problems, this paper proposes a discourse analysis of student-computer interaction enabled by viewing the student and the computer as two participants in a dialogue. It argues that the discourse analysis system of classroom interaction developed by Sinclair and Coulthard (1975) provides the necessary elements and structures to describe CALL discourse, analyze data from student-computer interaction, and compare CALL activities with other (classroom) activities.
Plasma ignition in free standing gas bubbles

Summary form only given. Achieving efficient plasma production in water is limited by two main factors: (1) the high breakdown strength of water, which increases the required voltage or energy input to produce plasma and (2) the high permittivity of water, which limits the penetration of the applied electric field. A recent approach used to circumvent these issues is to ignite plasma in gas bubbles injected into the water. These bubbles provide the high reduced fields (E/N) needed to maintain the discharge. To date, such discharges have been restricted to bubbles in contact with the electrode. In this study we investigate the formation of plasma inside free standing gas bubbles that are completely isolated from the driving electrode. Observation of discharge mechanisms in this geometry has yielded a host of new, complex phenomena. Chief among them is a multi-phase streamer that originates in the liquid but later makes contact with the bubble, igniting a secondary discharge inside the gas. Accompanying this interaction is an intense transfer of energy that destabilizes the bubble's shape. We also report on the successful ignition of plasma that is confined solely within the isolated gas bubble. In our experimental approach, the gas bubble, air or helium, is isolated by trapping it in the node of an ultrasonic acoustic wave. A pair of electrodes are positioned around the bubble using a 3-D translation stage. The electrodes are pulsed at 13.6 kV with a 1 us pulse length. Images of the resulting plasma formation are captured using a PIMAX ICCD camera with gate times in the 50-500 ns range.
Quantitative Assessment of Lesion Detection Accuracy, Resolution, and Reconstruction Algorithms in Neutron Stimulated Emission Computed Tomography

We present a quantitative analysis of the image quality obtained using filtered back-projection (FBP) with Ram-Lak filtering and maximum likelihood-expectation maximization (ML-EM)-with no postreconstruction filtering in either case-in neutron stimulated emission computed tomography (NSECT) imaging using Monte Carlo simulations in the context of clinically relevant models of liver iron overload. The ratios of pixel intensities for several regions of interest and lesion shape detection using an active-contours segmentation algorithm are assessed for accuracy across different scanning configurations and reconstruction algorithms. The modulation transfer functions (MTFs) are also computed for the cases under study and are applied to determine a minimum detectable lesion spacing as a form of sensitivity analysis. The accuracy of NSECT imaging in measuring relative tissue concentration is presented for simulated clinical liver cases. When using the 15th iteration, ML-EM provides at least 25% better resolution than FBP and proves to be highly robust under low-signal high-noise conditions prevalent in NSECT. However, FBP gives more accurate lesion pixel intensity ratios and size estimates in some cases; due to advantages provided by both reconstruction algorithms, it is worth exploring the development of an algorithm that is a hybrid of the two. We also show that NSECT imaging can be used to accurately detect 3-cm lesions in backgrounds that are a significant fraction (one-quarter) of the concentration of the lesion, down to a 4-cm spacing between lesions.
2005 Emil Thomas Kaiser Award

Collagen is the most abundant protein in animals. The conformational stability of the collagen triple helix is enhanced by the hydroxyl group of its prevalent (2S,4R)-4-hydroxyproline residues. For 25 years, the prevailing paradigm had been that this enhanced stability is due to hydrogen bonds mediated by bridging water molecules. We tested this hypothesis with synthetic collagen triple helices containing 4-fluoroproline residues. The results have unveiled a wealth of stereoelectronic effects that contribute markedly to the stability of collagen, as well as other proteins. This new understanding is leading to synthetic collagens for a variety of applications in biotechnology and biomedicine.
Suppression of 2-deoxy-d-glucose-augmented gastric secretion by hypothalamic lesions producing hyperphagia.

2-Deoxy-d-glucose (2-DG) at 100 mg./kg. administered subcutaneously to gastric fistula rats produced a pronounced augmentation of acid and pepsin secretion. The stimulatory effect of 2-DG on gastric function was abolished in rats which were rendered hyperphagic by ventromedial nuclear hypothalamic lesions. These studies provide further evidence that the ventromedial nuclei function either as centers or pathways in the mechanism by which an alteration in glucose metabolism within the central nervous system leads to augmented vagal activity.
Modulation of flavonoid biosynthetic pathway genes and anthocyanins due to virus infection in grapevine ( Vitis vinifera L.) leaves

Symptoms of grapevine leafroll disease (GLRD) in red-fruited wine grape (Vitis vinifera L.) cultivars consist of green veins and red and reddish-purple discoloration of inter-veinal areas of leaves. The reddish-purple color of symptomatic leaves may be due to the accumulation of anthocyanins and could reflect an up-regulation of genes involved in their biosynthesis. We examined six putative constitutively expressed genes, Ubiquitin, Actin, GAPDH, EF1-a, SAND and NAD5, for their potential as references for normalization of gene expression in reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). Using the geNorm program, a combination of two genes (Actin and NAD5) was identified as the stable set of reference genes for normalization of gene expression data obtained from grapevine leaves. By using gene-specific RT-qPCR in combination with a reliable normalization factor, we compared relative expression of the flavonoid biosynthetic pathway genes between leaves infected with Grapevine leafroll-associated virus 3 (GLRaV-3) and exhibiting GLRD symptoms and virus-free green leaves obtained from a red-fruited wine grape cultivar (cv. Merlot). The expression levels of these different genes ranged from two- to fifty-fold increase in virus-infected leaves. Among them, CHS3, F3'5'H, F3H1, LDOX, LAR1 and MybA1 showed greater than 10-fold increase suggesting that they were expressed at significantly higher levels in virus-infected symptomatic leaves. HPLC profiling of anthocyanins extracted from leaves indicated the presence of cyanidin-3-glucoside and malvidin-3-glucoside only in virus-infected symptomatic leaves. The results also showed 24% higher levels of flavonols in virus-infected symptomatic leaves than in virus-free green leaves, with quercetin followed by myricetin being the predominant compounds. Proanthocyanidins, estimated as total tannins by protein precipitation method, were 36% higher in virus-infected symptomatic leaves when compared to virus-free green leaves. The results, the first example to our knowledge, showed that modulation of the flavonoid biosynthetic pathway occurred in GLRaV-3-infected leaves of a red-fruited wine grape cultivar (cv. Merlot) leading to de novo synthesis of two classes of anthocyanins. These anthocyanins have contributed to the expression of reddish-purple color of virus-infected grapevine leaves exhibiting GLRD symptoms.
Exploring folding free energy landscapes using computational protein design

Recent advances in computational protein design have allowed exciting new insights into the sequence dependence of protein folding free energy landscapes. Whereas most previous studies have examined the sequence dependence of protein stability and folding kinetics by characterizing naturally occurring proteins and variants of these proteins that contain a small number of mutations, it is now possible to generate and characterize computationally designed proteins that differ significantly from naturally occurring proteins in sequence and/or structure. These computer-generated proteins provide insights into the determinants of protein structure, stability and folding, and make it possible to disentangle the properties of proteins that are the consequence of natural selection from those that reflect the fundamental physical chemistry of polypeptide chains.
On vacancy condensation and the origin of dislocations in growth from the melt

Abstract The formation of dislocations from condensed vacancies has been reexamined. Conditions for transformation of vacancy clusters into dislocation loops are analysed, taking into account an entropy contribution of atoms in the dislocation core. New evidence in the literature for a vacancy concentration beyond that of equilibrium at the advancing solid-liquid interface is used to calculate an excess vacancy concentration trapped in the solid as a function of freezing velocity. This excess leads to an estimation of the nucleation frequency of loops and supports the condensation mechanism as the source for dislocations. The critical stage for dislocation formation in growing crystals is also shown to depend upon the temperature distribution in the solid. Results of this analysis are applied to the formation of dislocations in a general f.c.c. metal, and specifically in lead, aluminium and copper, for which experimental information is available. Striation formation is discussed for these metals; it is co...
Nicotinic systems in central nervous systems disease: degenerative disorders and beyond.

Advances in the understanding of the structure, function, and distribution of central nervous system (CNS) nicotinic receptors has provided the impetus for new studies examining the role(s) that these receptors and associated processes may play in CNS functions. Further motivation has come from the realization that such receptors are changed in degenerative neurologic diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Ongoing investigations of the molecular substructure of CNS nicotinic receptors and their pharmacology have begun to open up new possibilities for novel CNS therapeutics with nicotinic agents. Exploiting these possibilities will require understanding of the role(s) that these receptor systems play in human cognitive, behavioral, motor, and sensory functioning. Clues from careful studies of human cognition and behavior are beginning to emerge and will provide direction for studies of potentially therapeutic novel nicotinic agents. Modulation of these receptors with the ultimate goal of producing therapeutic benefits is the goal of these investigations and drug development. This paper will review studies from our laboratory and others that point to the importance of CNS nicotinic mechanisms in normal human cognitive and behavioral functioning as well as their role in disease states. In addition, this paper will examine potential clinical applications of nicotine and/or nicotinic agonists in a variety of CNS disorders with particular emphasis on structural brain disease including: movement disorders such as Parkinson's disease and Tourette's syndrome, cognitive/behavioral disorders such as Alzheimer's disease, attention deficit/hyperactivity disorder, and schizophrenia, and other more speculative applications. Important results from early therapeutic studies of nicotine and/or nicotinic agonists in these disease states are presented. For example, recent studies with nicotine and novel nicotinic agonists such as ABT-418 by our group in AD patients suggest that nicotinic stimulation can improve the acquisition and retention of verbal information and decrease errors. Preliminary results from a series of studies examining the acute and subchronic quantitative effects of nicotine on cognitive and motor functioning in Parkinson's disease suggest that acute nicotine administration and stimulation improves some aspects of cognitive and motor performance and may improve the processing speed of more complex tasks. The most likely near-term applications of novel nicotinic agonists in CNS disorders are likely to be in those disorders that are degenerative in nature, e.g. Parkinson's disease and Alzheimer's disease, or other movement disorders such as Tourette's syndrome. The most likely direct therapeutic role for nicotinic agonists is as augmentation therapy in combination with other agents rather than as monotherapy, except early in disease states or as a prophylactic or preventative treatment.
The Medicare hospice benefit's influence on dying in nursing homes.

For dying nursing home residents, the prevalence of symptoms and care utilization prior to death has yet to be empirically described for a population-based sample. Yet, related work has suggested that the quality of care for dying nursing home residents is less optimal. The provision of Medicare hospice care in nursing homes offers a means for improving terminal care in nursing homes. However, other than controversial findings emanating from the U.S. Office of Inspector General's (OIG's) hospice studies, there is a dearth of evaluative research on the comparative costs and the benefits of Medicare hospice care in nursing homes. In this article, we discuss current knowledge concerning the dying experience of nursing home residents and of the influence of the Medicare hospice benefit in nursing homes. In doing so, we critique the OIG's study of hospice care in nursing homes and we raise concerns regarding access to the Medicare hospice benefit in nursing homes. We conclude by delineating the research needed...
Do Human Rights Have Religious Foundations

AbstractDo human rights have religious foundations? Among philosophers and theologians, the question tends to invite two standard replies. Some accept the boundary between the secular and the religious, and say that the universal protection of freedoms, possessions, and duties associated with human rights extend beyond any religious system. Others are impressed by arguments suggesting that the moral standards within human rights are inherently religious. In this paper I propose a third position. By taking the perspective of relative universalism, I draw a distinction between the conceptualization and implementation of human rights. The former is a historical process that is arguably bereft of religion, while the latter is a dynamic process that often embraces it. This distinction motivates my central thesis: although religion is absent from the normative and historical foundations of human rights, the realization of human rights in some regions of the world today often requires it.
Variability of Total Oil Content in Peanut Across the State of Texas

The state of Texas has three major regions with a history of peanut production: South Texas, Central Texas, and West Texas. The Texas A&M AgriLife peanut breeding program conducts replicated advanced yield trials at multiple locations within each of these regions annually. This study was initiated using entries from these same advanced line tests to determine if there were inter-regional and/or intra-regional differences in total oil content. The study was comprised of five cultivars used as checks in our yield tests and five advanced breeding lines. Three replications of each entry were tested for two South Texas, two West Texas, and two Central Texas locations. All of the samples were tested using nuclear magnetic resonance (NMR), which is a non-destructive test to determine the total oil content. A significant genotype by environment interaction was observed in both years of the study. Significant genotype differences were observed in all locations except the Stephenville location, which was inoculated...
Dications of 3-phenylindenylidenefluorenes: evaluation of antiaromaticity of indenyl and fluorenyl cations by magnetic measures.

Dications of p-substituted 3-phenylindenylidenefluorenes were prepared to examine the response of the resulting indenyl and fluorenyl cationic systems to magnetic measures of antiaromaticity. All measures, 1H NMR shifts, nucleus independent chemical shifts (NICS(1)zz), and magnetic susceptibility exaltation, Λ, supported the antiaromaticity of the dications 3a−f2+. The 1H NMR shifts and NICS(1)zz showed that the indenyl ring system was less antiaromatic than the fluorenyl ring system, contrary to the antiaromaticity of indenyl monocations compared to fluorenyl monocations. The presence of a phenyl substituent in the 3-position was able to stabilize the indenylidene cation through resonance, decreasing its antiaromaticity, but even in the absence of the 3-phenyl substituent, the indenyl system of indenylidenefluorene dications was less antiaromatic than the fluorenyl system. The decreased antiaromaticity of the 3-phenylindenylidenefluorene dications over the unsubstituted indenylidenefluorene dication was ...
THE EFFECT OF ELEVATION ON THE DISTRIBUTION OF SIBLING SPECIES IN THE SIMULIUM ARCTICUM COMPLEX (DIPTERA: SIMULIIDAE)

Abstract At least 5 sibling species and an additional 11 cytotypes of the Simulium arcticum complex occur in Montana. Consequently, this speciose complex might allow study of environmental correlates with genetic differentiation. We used conventional methods of collection and cytogenetic analysis to study 1128 male larvae of the Simulium arcticum complex at 15 sites within 5 drainages in western Montana to test the hypothesis that distribution of siblings is associated with elevation. We sampled at the mouth, at the headwaters, and at an intermediate site to span the range of elevations within each drainage. We restricted our analyses to the most abundant taxa of the S. arcticum complex within our study area and observed a statistically significant presence of S. apricarium at low-elevation sites. Simulium arcticum IIL-18 appeared more frequently than expected at high elevation sites. Simulium brevicercum and S. arcticum sensu strictu appeared to be distributed randomly. We suggest potential causal reason...
Large magnetostriction in Terfenol-D particulate composites with preferred [112] orientation

Terfenol-D particulate composites have been fabricated with and without a preferred crystal orientation of the particles. A 25% volume fraction polymer matrix composite was fabricated in a magnetic field using geometric anisotropy to orient needle shaped particles with long axis [112] orientation along the length of the composite. Results demonstrate that the magnetostriction of a [112] oriented particle composite saturates near 1600 ppm. This is a significant increase when compared to composites without preferential orientation (1200 ppm). The oriented particle composite exhibits the largest reported magnetostriction for a particulate composite material. The magnetization-strain measurements indicate that the strain in the oriented composite is proportional to the (lambda) 112 saturation magnetostriction while the non-oriented composite is proportional to the polycrystalline saturation magnetostriction, (lambda) pc. In addition, the fields necessary for equivalent magnetostriction in the oriented particle composite are reduced when compared to the non-oriented composite, though both require higher fields than commercially available monolithic Terfenol-D.
A Potential Outcomes View of Value-Added Assessment in Education.

There has been substantial interest in recent years in the performance and accountability of teachers and schools, partially due to the No Child Left Behind legislation, which requires states to develop a system of sanctions and rewards to hold districts and schools accountable for academic achievement. This focus has lead to an increase in “high-stakes” testing with publicized school rankings and test results. The papers by Ballou et al. (2004), McCaffrey et al. (2004) and Tekwe et al. (2004) approach the estimation of school and teacher effects through a variety of statistical models, known as “value-added” models in the education literature. There are many complex issues involved, and we applaud the authors for addressing this challenging topic.
Prolonged charge-separated states of starburst tetra(diphenylaminofluoreno)[60]fullerene adducts upon photoexcitation.

Construction of starburst C 60 (>DPAF-C 9 ) 4 pentads was coupled with the use of highly fluorescent diphenylaminofluorene-C9 (DPAF-C 9 ) addends as donor components in conjunction with the fullerene acceptor during single-photon excitation processes. High quantum yields (Φ CS ) of charge-separation processes in the range 0.83-0.90 for C 60 (>DPAF-C 9 ) n (n = 1, 2, or 4) were obtained in the formation of C 60 • - (>DPAF• + -C 9 )(>DPAF-C 9 ) n-1 transient states. The lifetime of the radical ion-pairs (TRIP) was found to be 900 ns for starburst C 60 (>DPAF-C 9 ) 4 (3) samples, which is 6-fold longer than that of the linear analogue C 60 (>DPAF-C 9 ) (1), with a ca. 2 times increase of the charge-separation rate (kcs) compared to that of 1. These data implied the important role of sterically hindered DPAF-C 9 pendants arranged in a starburst-like environment that encapsulates the central C 60 core on extending the TRIP. We interpreted the phenomena by the occurrence of intramolecular migration or exchange of electron or positive charge among multiple DPAF-C 9 pendants of C 60 •-(>DPAF• + -C9)(>DPAF-C9)n-1, which gives an increased rate in charge generation and delayed charge recombination.
Giant heterometallic Cu17Mn28 cluster with Td symmetry and high-spin ground state

Reaction of copper powder with Mn(OAc)2·4H2O and triethanolamine in DMF solution in air yields a high nuclearity, mixed-valent CuI4CuII13MnII4MnIII12MnIV12 cluster. X-ray crystallography shows that 1 contains an unprecedented adamantane-like Mn28 core connected wholly by Mn4O4 cubane units. Magnetic susceptibility data indicate a S = 51/2 ground state in low magnetic field with a S = 63/2 excited state only 5 K in energy above the ground state.
Thermalization of the muonic tritium atom in deuterium-tritium mixtures.

Thermalization of hot t\ensuremath{\mu} atoms formed in ${\mathrm{D}}_{2}$-DT-${\mathrm{T}}_{2}$ mixtures and relaxation of the triplet hyperfine state of t\ensuremath{\mu} are treated by Monte Carlo simulation. The cross sections for collisions with molecular targets are derived from cross sections for collisions with the component atoms. The statistical histograms for the time-dependent velocity distributions are fitted by sums of two Maxwellian functions, and the coefficients and temperatures are tabulated for tritium fractions of 10%, 50%, and 90% and mixture temperatures of 30, 100, and 300 K. The results provide a basis for analyzing some previously puzzling aspects of the observed cycling rate in recent muon-catalyzed-fusion experiments. In particular, thermalization is found to be very incomplete for some low-temperature targets. Also, the relative rates of kinetic thermalization and hyperfine-state relaxation depend strongly on the target tritium fraction, and hyperfine effects may be observable. The velocity distribution of t\ensuremath{\mu} atoms at times of molecular dt\ensuremath{\mu} formation is shown to depend only rather weakly on the initial velocity distribution, which is not well known.
The Viking Field, Blocks 49/12a, 49/16, 49/17, UK North Sea

Abstract First production from the Viking Fields began in 1972 and at its peak a total of 13 platforms produced at rates up to 950 MMSCF/D from 20 wells. This supplied around 10% of the United Kingdom9s natural gas requirements, 27 years on, that rate had declined to approximately 40 MMSCF/D. However following an extremely successful infield drilling programme in the mid 1990s, significant volumes of new gas have been discovered and new technology has facilitated the development of accumulations previously considered non-commercial. This has led to three new developments within the Viking area: the Vampire Field on the eastern margin; Kx to the south of the Philips9 Alison Field; and four previously non-producing fields, captured within the Phoenix Development. The major change since Morgan (1991) has primarily been the re-negotiation of the gas sales contract and the removal of the Gas Levy in 1992. This provided favourable marketing conditions for the development of additional Viking gas production and initiated an appraisal programme for remaining reserves. This programme, which will be the focus of this paper, began with the acquisition of a 3D seismic survey in 1993 and has concluded in the development of the Viking Extensions in 1998, now known as the Phoenix Development. The Leman Sandstone Formation forms the reservoir and consists of aeolian and fluvial sandstones, which are interbedded in the north of the area with silty shales deposited within a sabkha environment. Hydrocarbons were sourced from the underlying Carboniferous Westphahan coals and carbonaceous shales, and migration into the Rotliegendes Group probably occurred during the Late Cretaceous to Early Tertiary. The average daily production from the original Viking A and B fields and associated satellites had declined to 196 MMSCF/D by March 1989, peaking to over 300 MMSCF/D with seasonal demand. By October 1999, this had further reduced to around 40 MMSCF/D. Production from the Phoenix wells is currently at around 290 MMSCF/D, with further development wells planned. Cumulative production to date is approximately 2880 BCF.
Advances in open-channel hydraulics after V.T. Chow's book

Abstract Although Ven Te Chow was more well known for his scholarly contributions in the field of hydrology and water resources, his book entitled Open-Channel Hydraulics, published in 1959, has unquestionably been established as a classic book in hydraulics. In terms of thoroughness and extensiveness in coverage and information, it has not been surpassed by any of the open-channel hydraulics books published after 1959. Even today, nearly a quarter of a century after its publication, most of the material presented in Open-Channel Hydraulics still remains current and fresh. Nevertheless, within one generation, considerable advances have been made in the field of open-channel hydraulics. As expected, there have been numerous investigations into various aspects of open-channel flows, especially through the use of high-speed digital computers. Some of the significant advances in open-channel flow are briefly reviewed in this article, including: fundamental derivation of the basic, general open-channel flow equations; flow resistance over rigid boundaries; fluvial hydraulics (alluvial bed forms and sediment transports); mathematical models for steady and unsteady gradually varied flows; flood routing for dam breaks; hydraulic jumps; environmental hydraulics; and secondary currents in open-channel flows. The purpose of this article is to list some of the advances in open-channel flow, published since Dr. Chow's text: Open-Channel Hydraulics. This article does not attempt to comprehensively review all the advances made in this area of study. Although over 150 articles have been listed, the remarkable fact is that the content that comprises the main theme of Dr. Chow's book has not been surpassed. This clearly indicates that the great majority of his book still remains current and valid after 23 years of intensive research. Great advances in the study of fluvial hydraulics and mathematical modeling through the use of digital computers, the two major areas discussed in this article, have occurred since the publication of Dr. Chow's book in 1959. It was certainly a great pleasure for the writers to have known this giant in the field of water resources, hydrology, and hydraulics.
THE TOXICOLOGY OF MOISTURIZERS

AbstractMoisturizers are applied to dry skin on such a frequent and daily basis that key toxicologic questions must be asked regarding exposure to these emollients and their ingredients. The toxicologic variables are the composition of the moisturizers themselves, how long the moisturizer is in contact with the skin, how frequently the moisturizer is applied and reapplied, the area and skin site of the application, the skin's physiological response to such products, occasional responses of the body itself, and measuring and interpreting results from various prognostic tests on moisturizers. The actual skin condition and misuse of moisturizers are also important to know. Patients' reactions to moisturizers include, but are not limited to, irritant and allergic contact dermatitis, photocontact dermatitis from sunscreen-containing moisturizers, and, occasionally, contact urticaria. Dermatologists are recently describing reactions that can be called cumulative subclinical irritation to such products as well. ...
Isolation of lamellar bodies from neonatal mouse epidermis by selective sequential filtration

Isolation of epidermal lamellar bodies has presented a challenge because pressures required to homogenize keratinocytes can destroy these organelles and because the lamellar body readily releases its contents during prolonged isolation procedures. In an attempt to isolate lamellar bodies, sheets of intact stratum corneum and stratum granulosum were obtained from neonatal mice with highly purified staphylococcal epidermolytic toxin, disrupted, and passed through a series of filters. The final filtrate was rich in intact lamellar bodies and contained variable amounts of ribosomes and other vesicular structures. Availability of a highly purified lamellar body preparation from postnatal epidermis should help to clarify the role of this organelle in epidermal function. The technique of selective, sequential filtration represents a new approach to cell fractionation that may have wide applications in cell biology and biochemistry.
Identification of primary aromatic amines in mutagenically active subfractions from coal liquefaction materials

Abstract Gas-chromatographic mass spectral (GCMS) analyses were performed on mutagenically active components from the basic, basic tar and neutral tar subfractions of a coal-derived liquid heavy distillate. The latter material is a component fraction of an experimental oil produced in a solvent refined coal process (SRC II) pilot plant. Mutagenicity was determined with the Ames/Salmonella assay system. Thin-layer chromatography (TLC) was used to separate mutagenically active components of the basic, basic tar and neutral tar fractions from some of the other compounds contained in these complex materials. For the 3 fractions tested, mutagenic activity was localized in approx. the same TLC regions, with relative mobilities (R f ) ranging from 0.1 to 0.3. GCMS analysis of the TLC regions showed that the concentrations of primary aromatic amines, as obtained by measuring peak areas for the (M + 1) + ion as formed in the chemical ionization mode, followed essentially the same distribution as the mutagenic activity. Primary aromatic amines identified in the active regions included aminonaphthalenes, aminoanthracenes, aminophenanthrenes, aminopyrenes and aminochrysenes. With the exception of small amounts of aminonaphthalene, primary aromatic amines were not found in TLC regions that lacked mutagenic activity.
Calcium Requirements of Turkey Breeder Hens

Abstract LITTLE information is available on the effects of excess calcium on breeder chickens or turkeys, although Berg et al. (1962) have shown that 2.75 or 3.25% calcium in the diets of young chicken hens significantly depressed hatchability of eggs as compared with eggs from pullets fed 1.75 or 2.25% calcium. March and Biely (1961) reported increased mortality involving renal dysfunction in chicken hens fed 3 or 4% calcium, compared with that of hens fed diets containing 2% calcium. The National Research Council (1960) recommends 2.25% of calcium in turkey breeder diets, but Jensen et al. (1963) have reported that optimal performance, as measured by hatchability of eggs, was obtained with Broad Breasted Bronze hens fed diets containing 1.75% calcium. Higher levels, 2.5 and 3.25%, depressed hatchability but did not affect egg fertility, or growth and viability of progeny. Since many turkey breeder hens are fed oyster shell free-choice, resulting in…