cssi/SciSciGPT-SciSciNet huggingface dataset:
Stress in the Single Ventricle: Old Concepts, New Tools

See Article by Ghelani et al Functionally univentricular congenital heart disease, in which only 1 ventricle is fully developed, is fatal without treatment. It has an incidence of 0.08 to 0.4 per 1000 births.1 In patients with these types of congenital heart disease, the current treatment strategy (the Fontan operation) has reduced the mortality to the point where a large number of patients survive into adulthood. Using the Fontan strategy, the single ventricle provides the energy needed to provide blood flow through the systemic and the pulmonary vascular bed and is subjected to increased afterload. Other characteristics of the highly abnormal Fontan circulation include increased central venous pressures, a loss of pulsatility in the pulmonary arteries, and preload insufficiency of the single ventricle. Currently, early surgical mortality is ±1%.2 Ten-year survival among patients discharged with recent modifications of the Fontan circulation is ≈95% to 97%.3 Cardiac complications are frequent after this series of operations. The most common event is cardiac arrhythmia.4 Failure of the Fontan circulation is common (2% to 13% of patients).5 Extracardiac complications, also relating to the highly abnormal circulatory state, include coagulation abnormalities, resulting in thromboembolic events that have been reported to account for 8% of Fontan deaths.6 Other extracardiac complications include liver function abnormalities, cirrhosis and even hepatocellular carcinoma, protein-losing enteropathy, plastic bronchitis, and chronic kidney disease. Clearly, identification of patients at risk for poor ventricular function contributing to life-threatening events is key in this population. In this issue, Ghelani et al7 present their work aiming to assess whether the single ventricle with right ventricular (RV) morphology results in differences in ventricular fiber stress and strain compared with single ventricles of left …
Utility of prostate specific antigen doubling time (PSA-DT) at the start of androgen independent prostate cancer (AIPC) and immediately before chemotherapy in predicting efficacy of taxane chemotherapy

4640 Background: PSA-DT has been used to predict efficacy of various treatments for prostate cancer. No study has evaluated the ability of PSA-DT to predict efficacy of taxane chemotherapy, the sta...
A History of the Scientific Study of Sleep

Sleep research emerged in the stream of the life sciences in the late 1860s. Three historical reviews summarize the research through the early 1950s. This article focuses on the last 50 years of sleep research. A gathering of some 30 active sleep researchers responded to an invitation from Nathaniel Kleitman in 1961 that led to the formation of a sleep research society. It was around the annual meetings of the Association of the Psychophysiological Study of Sleep (APSS) that the organizational needs of the field were planned and discussed, which led to the development of standards of measurement, sleep journals, and bibliographic reviews. In the 1960s and early 1970s, sleep research was primarily focused on rapid eye movement (REM) sleep. Neurophysiological sleep research was a search for the locus and mechanisms underlying REM sleep. Animal and biological rhythm research reported on REM characteristics. Pharmaceutical studies tracked REM repression and rebound levels. Studies of REM sleep deprivation in both animals and humans were manifold. In the late 1970s, a decline in neurophysiological studies occurred as the field of sleep disorders medicine emerged. Three areas of substantial research – sleep deprivation effects, biological rhythms of sleep, and theories of sleep – are discussed in some detail. Lastly, the dominant place of sleep medicine research is noted.
Primary Cardiac Lymphoma: Importance of Tissue Diagnosis

Primary cardiac lymphoma (PCL) is a rare disease entity that can present with severe cardiac and cardioembolic symptoms. We present a 79-year-old male with history of polymalgia rheumatica on chronic prednisone who presented with a two-week history of progressively worsening dyspnea, cough, and a 10 pound weight loss. Transthoracic echocardiogram (TTE) and computed tomography (CT) of the chest showed a large mediastinal mass with invasion of the pericardium. A biopsy of an abdominal soft-tissue mass confirmed the diagnosis of PCL. The patient was treated with two cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) which was complicated by progressive heart failure requiring substitution of liposomal doxorubicin. The epidemiology, presentation, diagnosis, and treatment options of PCL are discussed.
Forest imageries and political practice in colonial coastal Kenya

ABSTRACTThis article explores the transforming meanings of kaya forests in coastal Kenya during first half of the twentieth century. It focuses on the deployment of the kaya–indicating lowland coastal forests with a linguistic connotation of “home” – as discursive tool in the political practices of elder Mijikenda men in their interactions with the colonial state. From the mid-nineteenth- to early-twentieth century, kaya forests were assigned a variety of meanings, including as historical settlements, ancestral graveyards, and ritual sites. By the late-colonial period, the forests and forest authorities – or kaya elders – were central categories of political practice on the Kenya coast. The article argues that elder Mijikenda men and colonial officials generated novel ideas about the significance of the kaya forests as they collaborated to establish bodies of legitimate authority and demarcate lands for colonial forestry projects and development schemes. In the process, they reworked and standardized the ...
Perovskite nickelates as bio-electronic interfaces.

Functional interfaces between electronics and biological matter are essential to diverse fields including health sciences and bio-engineering. Here, we report the discovery of spontaneous (no external energy input) hydrogen transfer from biological glucose reactions into SmNiO3, an archetypal perovskite quantum material. The enzymatic oxidation of glucose is monitored down to ~5 × 10−16 M concentration via hydrogen transfer to the nickelate lattice. The hydrogen atoms donate electrons to the Ni d orbital and induce electron localization through strong electron correlations. By enzyme specific modification, spontaneous transfer of hydrogen from the neurotransmitter dopamine can be monitored in physiological media. We then directly interface an acute mouse brain slice onto the nickelate devices and demonstrate measurement of neurotransmitter release upon electrical stimulation of the striatum region. These results open up avenues for use of emergent physics present in quantum materials in trace detection and conveyance of bio-matter, bio-chemical sciences, and brain-machine interfaces. Functional materials that act as bio-sensing media when interfaced with complex bio-matter are attractive for health sciences and bio-engineering. Here, the authors report room temperature enzyme-mediated spontaneous hydrogen transfer between a perovskite quantum material and glucose reactions.
Tetraplegia to Overground Stepping Using Non-Invasive Spinal Neuromodulation

Paralysis of the upper extremity (UE) and lower extremity (LE) following cervical spinal cord injury (SCI) significantly impairs the individual’s ability to live independently. While improvement in hand function is considered one of the most desired functions in tetraplegics, few therapies have been successfully developed. Spinal cord stimulation have been shown to be effective in enabling UE and LE function individually. However, improvement of both UE and LE function concomitantly, using the same therapeutic modality has not been demonstrated. This study demonstrates that noninvasive neuromodulation of the spinal cord can improve hand function and stepping abilities in an individual with severe chronic paralysis. The improvements in UE and LE function were accompanied by improvement in autonomic function and sensation below the level of the lesion. Regaining these functions in the individual with severe, chronic paralysis had dramatic impacts functionally and psychologically.
The association between Food and Alcohol Disturbance (FAD), race, and ethnic identity belonging.

A growing body of literature has established that food and alcohol disturbance (FAD: decreasing one’s caloric intake in preparation for alcohol consumption) is a specific health risk that endangers health and wellbeing. Recent research on trends in FAD has revealed ethno-racial disparities. A sociological analysis is helpful to center race and examine the role of ethnic identity in reproducing health disparities. The current study is guided by theories of socialization into ideal body types by race. Study uses data from a cross-sectional survey conducted among college students. The sample includes White and Black American college students, ages 18–25, and uses ordinal logistic regression to test for the impact of race and ethnic identity on engagement in FAD using the Compensatory Eating and Behaviors in Response to Alcohol Consumption Scale (CEBRACS). FAD prevalence was lower among Black Americans than among White Americans in the sample. Results from ordered logistic regression models indicate that stronger ethnic ties reduce likelihood of FAD among Black Americans but have the opposite effect among White Americans. This modification effect provides evidence that ethnic identity belonging protects against FAD for Black Americans but acts as a risk factor for FAD among White Americans. Findings shed light on the documented racial disparities in FAD and weight control behavior more broadly. Ethnic identity modifies the relationship between race and FAD in our sample. Level V, cross-sectional descriptive study
Treatment of depressive symptoms in breast cancer patients undergoing adjuvant therapy.

9631 Background: Studies have shown a high prevalence of depression in patients with cancer. Women with breast cancer may have a high risk of depression particularly in a post-menopausal or estroge...
The History of the Nineteenth-Century American Peace Reform Press: Some Research Issues and Directions

Throughout American history, journalism has played an Instrumental role in movements for peace. From the Friend of Peace, the Calumet, and the Peacemaker In the nineteenth century to World Affairs, Friends Journal, and the Catholic Worker In the twentieth century, peace periodicals have been a significant channel of communication both within peace movements and beyond. Since colonial days, countless individuals and organizations have embraced peace as their first principle of social action and reformation; indeed, historians have established the centrality of the peace reform In the American reform tradition (Footnote 1). Peace advocates have expressed their commitment in diverse ways: through religious forms (e.g., the historic peace churches: the Quakers, the Mennonites, and the Brethren); through nonsectarian forms (e.g., the peace reforms of the antebellum American Peace Society and the post-Civil War Universal Peace Union); and through secular forms (e.g., the twentieth-century Women’s International League for Peace and Freedom).
Problems with automating translation of movie/TV show subtitles.

We present 27 problems encountered in automating the translation of movie/TV show subtitles. We categorize each problem in one of the three categories viz. problems directly related to textual translation, problems related to subtitle creation guidelines, and problems due to adaptability of machine translation (MT) engines. We also present the findings of a translation quality evaluation experiment where we share the frequency of 16 key problems. We show that the systems working at the frontiers of Natural Language Processing do not perform well for subtitles and require some post-processing solutions for redressal of these problems
Modeling Scattering Differences between Sea Ice Ridges

Sea ice ridges pose some of the greatest threats to navigation in polar and sub-polar regions and it is important to characterize ridges using remote sensing data. First year (FY) ridges and multi-year (MY) ridges may be present in the same region, but MY ridges are stronger and have the potential to cause greater damage to vessels and structures. A new approach has been developed to model electromagnetic (EM) scattering from sea ice ridges. Ridges are represented as having a rough surface over horizontally stratified and isotropic layers. The total scatter from the ridge is the sum of the scatter from the surface and the layers. This paper provides an overview of the modeling process and provides some initial simulation results showing the impacts of radar frequency and ice salinity on the scattered wave. Ice ridge surface and structure characteristics affect the nature of the scattered signal and additional work is required to determine if it is possible to reliably distinguish between ridge types. Future work will involve simulations using more detailed modeling of ice ridge profiles to better determine how radar frequency and ice ridge structure and phenology affect ice discrimination.
Sleep and GER

Gastroesophageal reflux (GER) occurs during sleep. During sleep time, GER events are caused by transient lower esophageal sphincter (LES) relaxations occurring during arousals from sleep. Sleep-related GER events occur more commonly out of arousals from stage N2 NREM sleep, especially during the first 2 h of the sleep period, and esophageal refluxate clearance is delayed during sleep. Prevalence of sleep-related GER approximates 79 % in GER patients and 25 % of the adult population. Symptoms of sleep-related GER include heartburn, regurgitation, arousals, awakenings, insomnia, unrefreshing sleep, daytime sleepiness, and fatigue. Patients with obstructive sleep apnea commonly have sleep-related GER, and treatment with nasal CPAP improves sleep-related GER. The diagnosis of sleep-related GER is made on clinical grounds; however, esophageal testing is useful in selected patients. Treatment of sleep-related GER includes behavioral techniques and proton pump inhibitors (PPIs). There are less data available that address the role of surgical fundoplication and long-term medical therapy outcomes in sleep-related GER. Hopefully, future research will provide better insight.
SOME FURTHER THOUGHTS ON CULTURE AND ENVIRONMENT

I begin with a recent book Culture, Architecture, and Design that summarizes my work on culture environment relations. Three of its important general points are discussed and some possible misconceptions clarified (e.g. that culture is the only, or most important, variable). Some other points are elaborated and developed, and a number of important new developments, concepts, findings and ideas introduced from a number of relevant sciences. In this connection I reiterate the importance of Environment Behavior Studies-EBS being a science, hence developing explanatory theory and, consequently the importance of keeping up with a large number of disciplines beyond those with which EBS started. The relevance of those may not be apparent at first, but becomes apparent at some level of abstraction. Among new topics introduced are the potential role of culture in nonresidential environments (so far not much discussed), the question of cultural identity and the possible role of scale in both. The utility of dismantling for a number of the topics introduced is re-emphasized. Among important new concepts I emphasize human universals, the evolution of culture, the role of niche construction and the handicap principle (costly signaling), rule systems (and simulation) and their implications for studying culture-environment relations.
Transfusion‐Related Immunomodulation

SUMMARY Allogeneic blood transfusion (ABT) has been claimed to cause deleterious clinical effects, including the recurrence of resected malignancies, postoperative bacterial infection, and virus activation. These purported adverse effects of ABT have been attributed to transfusion-related immunomodulation (TRIM). However, the mechanism(s) of the TRIM effect(s) remains or remain to be defined, and the blood constituent(s) that might mediate TRIM effect(s) is or are unknown. Randomized, controlled trials (RCTs) have been conducted to investigate the TRIM effect(s), based on the assumption that the transfusion of autologous or leukoreduced allogeneic red blood cells is immunologically neutral. The findings of these RCTs have been highly contradictory, and the long-standing hypothesis of a deleterious TRIM effect of ABT remains unresolved. This review examines the clinical evidence as to whether a deleterious TRIM effect exists and can be abrogated by leukoreducing transfused cellular blood components.
Phospholipids of Clostridium butyricum III. FURTHER STUDIES ON THE ORIGIN OF THE ALDEHYDE CHAINS OF PLASMALOGENS

Abstract 1. The phosphatide plasmalogens of Clostridium butyricum, mainly ethanolamine and N-methylethanolamine plasmalogens, have been catalytically reduced and the resulting saturated glycerol ethers isolated as diacetate derivatives. Nuclear magnetic resonance spectra showed that the linkage of the ether chain was 1(3)-glycerol. Hydrolysis of the diacetates followed by periodate oxidation yielded close to an equivalent amount of formaldehyde, in confirmation of the 1(3)-linkage. 2. The aldehyde chains released from the phosphatide plasmalogens were analyzed by gas-liquid chromatography and shown to be similar in composition to the published composition of the 1-linked fatty acids of phosphatidylethanolamine from the same organism. 3. A study of the kinetics of incorporation of 1-14C-acetate into the phospholipid fraction of growing C. butyricum showed that the fatty acids had specific activities 5 to 6 times higher than those of the corresponding aldehydes after 5 to 10 min, and 2 to 3 times higher after 45 min. In the neutral lipid fraction, the esterified fatty acids had higher specific activities than the aldehydes up to 45 min after addition of 1-14C-acetate; subsequently, the ratios were reversed. Pathways from acetate to aldehydes to acids are not consistent with the data. The results are consistent with a derivation of the long chain aldehydes from the corresponding fatty acids. 4. Growing cells of C. butyricum incorporated 1-3H-1-14C-palmitaldehyde into fatty acids of plasmalogens with loss of 98% of the tritium, and into the aldehydes of plasmalogens with loss of about 85% of the tritium. Most, but not all, of the labeled palmitaldehyde appeared to have undergone oxidation prior to incorporation into plasmalogen-bound aldehyde.
A theory of average-case compilability in knowledge representation

Compilability is a fundamental property of knowledge representation formalisms which captures how succinctly information can be expressed. A l though many results concerning compilability have been obtained, they are all "worst-case" results. We develop a theory of average-case compilability which allows for the formal comparison and classification of knowledge representation formalisms "on average."
Solution of Euler's equations on adaptive grids using a fast unstructured grid second order Godunov solver (FUGGS)

We describe a new technique for solving Euler's gasdynamic equations on unstructured triangular grids with arbitrary connectivity. The formulation is based on the second order Godunov method. The use of data structure with only one level of indirectness leads to an easily vectorized and parallelized code with a low level of overhead in memory requirement and high computational efficiency. The performance and accuracy of the algorithm has been tested for a very wide range of Mach numbers starting from very low subsonic to high hypersonic flows, without the need to adjust any code parameters. The algorithm was implemented in a vertex based and triangle based scheme. The computational results produced by the triangle based version showed an extremely low level of artificial viscosity.
Quantitative compositional analysis of sedimentary materials using thermal emission spectroscopy: 1. Application to sedimentary rocks

Thermal emission spectroscopy is used to determine the mineralogy of sandstone and mudstone rocks as part of an investigation of linear spectral mixing between sedimentary constituent phases. With widespread occurrences of sedimentary rocks on the surface of Mars, critical examination of the accuracy associated with quantitative models of mineral abundances derived from thermal emission spectra of sedimentary materials is necessary. Although thermal emission spectroscopy has been previously proven to be a viable technique to obtain quantitative mineralogy from igneous and metamorphic materials, sedimentary rocks, with natural variation of composition, compaction, and grain size, have yet to be examined. In this work, we present an analysis of the thermal emission spectral (~270–1650 cm−1) characteristics of a suite of 13 sandstones and 14 mudstones. X-ray diffraction and traditional point counting procedures were all evaluated in comparison with thermal emission spectroscopy. Results from this work are consistent with previous thermal emission spectroscopy studies and indicate that bulk rock mineral abundances can be estimated within 11.2% for detrital grains (i.e., quartz and feldspars) and 14.8% for all other mineral phases present in both sandstones and mudstones, in comparison to common in situ techniques used for determining bulk rock composition. Clay-sized to fine silt-sized grained phase identification is less accurate, with differences from the known ranging from ~5 to 24% on average. Nevertheless, linear least squares modeling of thermal emission spectra is an advantageous technique for determining abundances of detrital grains and sedimentary matrix and for providing a rapid classification of clastic rocks.
The Mental Health of the Older Homeless Population: Provider-Perceived Issues Related to Service Provision:

In this article I discuss providers of homeless services' perceptions of the mental health needs of individuals who are homeless and aged 50 to 64 as they relate to service provision.1 To accomplish this task, I analyzed fifty-six interviews conducted with providers of homeless services in the city of Chicago. These interviews were completed as part of a larger study conducted in collaboration with the coordinating body of the local homeless service system in an effort to better understand the unique issues affecting the older homeless population and to develop appropriate policy and programmatic responses to these issues. Issues providers most readily point to are important to understand when developing policy and programming because they are likely to represent problems providers most frequently encounter or that providers find to be the most difficult to resolve in their daily work. Qualitative analysis of interviews pointed to six recognizable issues providers were concerned with regarding this older ...
Efficient segmentation of large-area skin images: an overview of image processing.

Background/aims: This paper is the first of a series describing research and development performed by the SPOTS project towards automating the process of monitoring pigmented lesions for change over time. A comprehensive overview of digital image processing techniques used for the systematic approach to segmentation of large-area skin images, including the description and classification of skin features, is presented. Methods: The multiresolution hierarchical segmentation technique, which makes use of image pyramid data structures and cooperative computation with unforced linking, was used to group pixels with similar color properties. This technique was further enhanced to enforce contiguity of segments by determining connected components. The resulting segmentation was then classified by using representative properties of pyramid nodes as input to a cascade of multilayer perceptron neural networks trained using the classical backpropagation algorithm. In order to make our system more resistant to imaging distortions, a technique was developed to grow regions based upon the resulting classification. Conclusions: This system produces a segmentation at multiple resolutions based upon color, where each segment is a contiguous group of pixels on the image. The classification makes use of both spatial and color properties, as well as parent-child relationships within the pyramid. The addition of classification-driven region growing reduces the change in lesion area where the boundary fades into surrounding skin. Furthermore, the system contains parameters that can be tuned to provide desirable results.
Cryogenic Silicon Photoconductive Switches For High Power Lasers

Silicon photoconductive switches have the potential to replace such plasma discharge switches as sparkgaps and thyratrons that are commonly found in pulsed laser drive circuits. This offers the possibility of developing advanced modulators that are all solid-state, and which enjoy the advantages of improved efficiency, compactness, and life expectancy. Silicon operating at liquid nitrogen temperature is especially attractive as a power switch because at 77K it displays an extremely low coefficient of thermal expansion, a large optical absorption depth for 1.06um light, and a large thermal conductivity. These factors allow low temperature silicon to switch power levels an order of magnitude greater than at 300K, and an experimental cyrogenic silicon switch has been made to switch pulses of 15kV, 1.2kA, 0.5uS duration at 100Hz recurrent frequency. It is shown that silicon switches compare favorably with thyratrons in terms of electrical ratings and energy transfer efficiency, and should be considered in advanced pulser designs for both terrestrial and space applications.
New Insights into the Evolutionary Links Relating to the 3-Deoxy-D-arabino-heptulosonate 7-Phosphate Synthase Subfamilies

Abstract Bacterial 3-deoxy-d-arabino-heptulosonate 7-phosphate synthases (DAHPSs) have been divided into either of two classes (Class I/Class II) or subfamilies (AroAIα/AroAIβ). Our investigation into the biochemical properties of the unique bifunctional DAHPS from Bacillus subtilis provides new insight into the evolutionary link among DAHPS subfamilies. In the present study, the DAHPS (aroA) and chorismate mutase (aroQ) activities of B. subtilis DAHPS are separated by domain truncation. Detailed enzymatic studies with the full-length wild-type protein and the truncated domains led to our hypothesis that the aroQ domain was fused to the N terminus of aroA in B. subtilis during evolution for the purpose of feedback regulation and not for the creation of a bona fide bifunctional enzyme. In addition, examination of aroA and aroQ fusion proteins from Porphyromonas gingivalis, in which the aroQ domain is fused to the C terminus of aroA, further supports the hypothesis. These results, along with sequence structure analysis of the DAHPS families suggest that “feedback regulation” may indeed be the evolutionary link between the two classes/subfamilies. It is likely that DAHPSs evolved from a primitive unregulated member of the AroAIβ subfamily. During evolution, some members of the AroAIβ subfamily remained unregulated, whereas other members acquired an extra domain for feedback regulation. The AroAIα subfamilies, however, evolved in a more complex manner to acquire insertions/extensions in the (β/α)8 barrel to function as regulatory elements.
Erythema multiforme: Report of two cases and speculation on immune mechanisms involved in the pathogenesis

Abstract It has been postulated that an immunological mechanism may play an important role in the pathogenesis of erythema multiforme. In this report the immunological studies of two patients with clinical and histological evidence of erythema multiforme bullosa are presented. The complement components (C1q, C2, C3, C4) were shown to be markedly reduced in the blister fluid. The cleavage of more than 90% of C3, C4 and factor B was observed. Using the C1q I 125 deviation test, elevated levels of immune complexes were present in the blister fluid but not in the serum samples. IgG antibody was increased in both the serum and blister fluid. These findings strongly suggest that immune complexes are activating complement components via the classical pathway in the blister fluid of patients with erythema multiforme bullosa. Reduction in the number of T lymphocytes and decrease in the lymphocyte transformation responses to mitogens and antigens seen in one patients probably suggests why patients with erythema multiformed are more susceptible to various infections in the course of their disease.
Characterization of the myoglobin of the lamprey Petromyzon marinus

Myoglobin has been identified in the myocardium of the lampreyPetromyzon marinus, one of the most primitive of all vertebrates. This protein was isolated by ammonium sulphate fractionation and purified by successive chromatography on Ultrogel AcA 54, DEAE-Sephadex and CM-23 cellulose. The molecule differs substantially from the monomeric hemoglobins found in the lamprey as evidenced by its elution profile on DEAE-Sephadex and the fingerprint pattern of its enzymically-produced peptides. The functional significance of this protein in Agnatha is discussed.
Radical-mediated photoreduction of manganese(II) species in UV-irradiated titania suspensions

Abstract New data are reported on the radical-mediated photoreduction of Mn(II) species in UV-irradiated TiO 2 suspensions. The influence of organic co-additives on the fate of Mn(II) ions in these media is the major focus of this study. It is also shown that some of these co-additives (formate, acetate or oxalate) induce the initial adsorption of Mn 2+ ions on the TiO 2 particle surfaces in the dark. The influence of co-additive level, suspension pH, and TiO 2 particle dose on the photoreduction kinetics, is described. Experiments seeking the product identity and general conclusions that can be made from this study are finally presented.
Preparing for a “Big One”: The Great Southern California ShakeOut:

The Great Southern California ShakeOut was a week of special events featuring the largest earthquake drill in United States history. On November 13, 2008, over 5 million Southern Californians prete...
Error analysis of numerical schemes for the wave equation in heterogeneous media

Abstract A family of finite difference schemes for the acoustic wave equation in heterogeneous media is introduced. The precision and computational cost are analyzed in two cases. First, a two-layered medium is considered. The order of convergence at the interface is derived for each scheme. Given an a priori accuracy on the solution, the computational cost is studied as a function of the order of accuracy of the finite difference scheme. It is demonstrated that this function has a minimum. The previous results are extended to the case of random media by a numerical study. Similar conclusions about precision and cost are found.
Stereoselectivity in the metal complex catalyzed hydrolysis of amino acid esters — III Distribution equilibria

Abstract A study of the equilibria involving nickel(II) and equimolar amounts of different optically active amino acids shows that in such systems the mixed complexes, MAB, are favored to a greater extent than would be predicted from statistical considerations alone. Insofar as mixtures of optical isomers of a given amino acid are concerned, stereoselectivity in the stability constants of nickel(II) complexes was found only in the case of histidine. When optical isomers of a pair of amono acids were involved, no stereoselectivity was observed for the stability constants of any of the mixtures examined. These results correlate rather closely with most stereoselectivity studies involving the metal-complex catalyzed hydrolysis of amino acid esters. An anomaly exists, however, in the case of the tryptophan-histidine data, that suggests a more complicated relationship between the thermodynamic and kinetic stereoselectivities.
All-optical latches based on two-photon absorption in semiconductor optical amplifiers

The design and performance of two optical latches, the set–reset (S-R) latch and D flip-flop have been studied. These latches are the building blocks of large optical processors. The latches are built using two optical logic operations NAND and NOT. Both NAND and NOT operations are realized by using the ultrafast phase response during two-photon absorption process in semiconductor optical amplifiers. Rate equations for semiconductor optical amplifiers, for input data signals with high intensity, configured in the form of a Mach–Zehnder interferometer, have been solved. The input intensities are high enough that the two-photon induced phase change is larger than the regular gain induced phase change. Results show that this scheme can realize the functions of the S-R latch and D flip-flop at high speeds (∼250 Gb/s) with good signal-to-noise ratio.
Flexible vision-based navigation system for unmanned aerial vehicles

A critical component of unmanned aerial vehicles in the navigation system which provides position and velocity feedback for autonomous control. The Georgia Tech Aerial Robotics navigational system (NavSys) consists of four DVTStinger70C Integrated Vision Units (IVUs) with CCD-based panning platforms, software, and a fiducial onboard the vehicle. The IVUs independently scan for the retro-reflective bar-code fiducial while the NavSys image processing software performs a gradient threshold followed by a image search localization of three vertical bar-code lines. Using the (x,y) image coordinate and CCD angle, the NavSys triangulates the fiducial's (x,y) position, differentiates for velocity, and relays the information to the helicopter controller, which independently determines the z direction with an onboard altimeter. System flexibility is demonstrated by recognition of different fiducial shapes, night and day time operation, and is being extended to on-board and off-board navigation of aerial and ground vehicles. The navigation design provides a real-time, inexpensive, and effective system for determining the (x,y) position of the aerial vehicle with updates generated every 51 ms (19.6 Hz) at an accuracy of approximately +/- 2.8 in.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Role of glutathione S-transferases A1-1, M1-1, and P1-1 in the detoxification of 2-phenylpropenal, a reactive felbamate metabolite.

GSTA1-1. Given that electrophilic substrates such as 2-propenal have been shown to inhibit GSTs, we also examined the inhibition of GSTM1-1, GSTP1-1 and GSTA1-1 by 2-phenylpropenal. The enzyme inhibition studies demonstrate that 2-phenylpropenal inhibits GSTP1-1 and GSTM1-1. The inhibition of GSTP1-1 was completely reversible upon filtration and reconstitution in buffer containing 10 mM GSH. However, 2-phenylpropenal inhibition of GSTM1-1 was irreversible under the same conditions. The irreversible inhibition of GSTM1-1 may be important in understanding the toxicities associated with felbamate. Given that 2-phenylpropenal is both a substrate and irreversible inhibitor for GSTM1-1, GSTM1-1 represents a potential target for 2-phenylpropenal haptenization in vivo, which may in turn mediate the observed idiosyncratic reactions.
IBM journal of research and development: information for authors

This paper combines background information about the IBM Journal of Research and Development with guidelines for the preparation of Journal manuscripts. The purpose is to acquaint authors with the Journal as a primary, professional publication and to present suggestions to ease the work of author and editor in preparing clear, concise, and useful manuscripts.
TAKING ADVANTAGE OF HOMOGENEITY: A UNIFIED FRAMEWORK FOR OUTPUT FEEDBACK CONTROL OF NONLINEAR SYSTEMS

Abstract A unified framework is presented for global output feedback stabilization of a family of uncertain systems with low- and high-order nonlinearities. By taking advantage of homogeneity, together with a domination-based observer/controller design, this framework not only incorporates a number of results proposed recently in the literature, but also yields new results for more general classes of non-uniformly observable and non-smoothly stabilizable systems, whose global stabilization problem cannot be addressed by existing output feedback control schemes. The novelty of this paper lies in the development of a reduced order observer-based output feedback design method, making it possible to compensate simultaneously low-order nonlinearities that dominate near the origin, and high-order nonlinearities that dominate far away from the origin.
Comparison of dantrolene sodium with erythromycin estolate using primary cultures of rat hepatocytes.

ABSTRACTUsing primary cultures of parenchymal hepatocytes as a model system, the cytotoxic potential of dantrolene sodium (DS) was compared with that of erythromycin estolate (EE)—a known hepatotoxin. Parallel morphological and functional comparisons were made, following 4-, B-, or 24-h exposures of hepatocyte cultures, using phase contrast microscopy and lactate dehydrogenase (LOH) leakage, respectively. Four-hour exposures of cultures to rather low concentrations of EE (i. e. 50 μM) resulted in cellular necrosis and significantly elevated LDH release. As the concentration of this hepatotoxin was increased, the changes were more pronounced. However, even 4-or 8-h exposures of cultures to a maximum of 100 μM DS did not affect LDH leakage or morphological integrity, although marginally detectable morphological changes did occur at the highest concentration after 24-h. The value of using primary parenchymal hepatocyte cultures as a model system for the assessment of xenobiotic-induced hepatotoxicity was con...
Discriminative stimulus and response rate-decreasing effects of kappa opioids: Antagonism by naloxone

Abstract The present study examined the discriminative stimulus and response rate-decreasing effects of kappa opioids in pigeons trained to discriminate a 0.017 mg/kg dose of bremazocine from saline. Bremazocine, spiradoline, C1977, U69, 593 and U50, 488 substituted completely for the bremazocine stimulus in a dose-dependent and naloxone-reversible manner. Apparent pA 2 values (range, 6.01–6.81) of naloxone against the descriminative stimulus effects of these kappa opioids were smaller than those reported previously in the pigeon for naloxone against the discriminative stimulus effects of various mu opioids. Bremazocine, C1977, soiradoline and U69, 593 also decreased rate of responding in a dose-dependent and naloxone-reversible manner. The apparent pA 2 values (range, 6.25–6.44) for naloxone against the rate-decreasing effects of bremazocine, C1977 and U69, 593 were not different from the apparent pA 2 values for naloxone against their discriminative stimulus effects. An apparent pA 2 for naloxone against the rate-decreasing effects of spiradoline could not be determined due to the shallow slope of the Schild plot. Although the rate-decreasing effects of U50, 488 were antagonized by naloxone, the degree of antagonism was small and not dose-dependent. These findings indicate that the discriminative stimulus and rate-decreasing effects of some kappa opioids are mediated by similar mechanisms and that a non-opioid mechanism may contribute to the rate-decreasing effects of spiradoline and U50, 488.
The effect of glucagon on spontaneous contractility of isolated pregnant uterine muscle.

Objective To determine whether glucagon has relaxant effects on the spontaneous contractions of term pregnant human uterine smooth muscle in an isolated preparation. Methods Myometrial specimens were excised from the upper incisional surface of the lower uterine segment in seven women during elective cesarean delivery. The muscle strips were suspended in tissue baths and isometric tension was recorded. After establishing rhythmic spontaneous contractions, glucagon reconstituted with distilled water or the accompanying diluent was added directly to the bath in a cumulative manner. In the second phase of the study, the effect of the diluent (1.6% glycerin with 0.2% phenol) alone on muscle contractility was evaluated. Results Glucagon had no effect on uterine muscle concentrations when reconstituted with distilled water. However, glucagon reconstituted with the diluent decreased the contractile amplitude by 27 ± 11% (mean ± standard deviation, P P μ g/mL. At a cumulative concentration of 40 μ g/mL, the reductions in amplitude and frequency were 65 ± 13% ( P P P > .2, power 90%, α = .05). Conclusion These results suggest that relaxation of contractions was likely caused by the diluent rather than by glucagon. We conclude that glucagon does not have a direct relaxant effect on spontaneous contraction of isolated uterine muscle obtained from term pregnant uteri.
Small changes in polymer chemistry have a large effect on the bone–implant interface:: evaluation of a series of degradable tyrosine-derived polycarbonates in bone defects

In a series of homologous, tyrosine-based polycarbonates, small changes in the chemical structure of the polymer pendent chain were found to affect the bone response in a long-term (1280 d) implantation study. Identically sized pins, prepared from poly(DTE carbonate), poly(DTB carbonate), poly(DTH carbonate), and poly(DTO carbonate) were implanted transcortically in the proximal tibia and the distal femur of skeletally mature New Zealand White Rabbits. The tissue response at the bone-implant interface was characterized in terms of the absence of a fibrous capsule (direct bone apposition, indicative of a bone bonding response) or the presence of a fibrous capsule (referred to as the encapsulation response). The relative frequency of direct bone apposition versus encapsulation was recorded for each polymer throughout the entire period of the study. While all four polymers were tissue compatible, there was a correlation between the chemical structure of the pendent chain and the type of bone response observed, with poly(DTE carbonate) having the highest tendency to elicit direct bone apposition. Based on in vivo degradation data and the ability of model polymers with carboxylate groups at their surface to chelate calcium ions, it is proposed that the ability of poly(DTE carbonate) to bond to bone is caused by the facile hydrolysis of the pendent ethyl ester groups which creates calcium ion chelation sites on the polymer surface. The incorporation of calcium chelation sites into the chemical structure of an implant material appears to be a key requirement if direct bone apposition/bone bonding is desired. This study demonstrates that very subtle changes in the chemical composition of an implant material can have significant effects on the long-term tissue response in a clinically relevant model.
Practical design of optical diagnostics for chirped-pulse free-electron lasers

Abstract In recent years there have been several proposals to operate rf-linac-driven FELs with chirped electron and optical micropulses for use in fast time-resolved experiments. We have been actively pursuing this application on the Mark-III infrared FEL at Duke University, and have designed and procured an apparatus to achieve broad-band compression of chirped optical pulses between roughly 2.5 μm and 4.1 μm, with subsequent measurement of pulse widths as short as 200 fs. The principles of design for this experiment will be reviewed, and extensions of the design to other wavelengths will be considered.
Recent results for excitonic processes in the spectra of metals and alloys

Over the past year our understanding of optical and other excitation processes which create electron-hole pairs in metals and alloys has been completely revised. It is now clearly established that the Coulomb interaction between the electron and hole carriers freshly created in the optical event plays a major role in determining the response of the metal. This article describes the experimental and theoretical developments which underlie the new understanding of these processes. The new work concerns: (i) shallow excitations in alloys; (ii) excitonic processes which modify interband transitions in pure polyvalent metals and (iii) deep interband transitions which occur in the famous “x-ray edge” problem for metals and alloys.
Potential role of high-power laser diode in manufacturing

We present examples of manufacturing applications like solid freeform fabrication by sintering metal/ceramic powders, and drilling using semiconductor laser diodes. From the stand point of energy requirements, these demonstration indicates that many other laser manufacturing functions like cutting, soldering, marking, printing, etc. can be carried out by currently available commercial laser diodes. Most of these applications are currently being done by the inefficient and bulky lasers like CO2, Nd:YAG and Excimer. These are 30 years matured technologies and still costs over $DOL150/Watt. We believe the price of semiconductor laser diode chips, like computer chips, will come down rapidly, as volume market opens up, from $DOL300/Watts today to less than $DOL10/Watt in 5 years. The paper begins with some market survey indicating economic opportunities for high power diode companies.
Advocacy Issues and Strategies for the 21st Century Key Informant Interviews

The authors conducted key informant interviews with 16 disability advocacy and research leaders; half of the interviews were with leaders in shaping national disability policy during and after pass...
Sequence analysis of cDNA encoding follicle-stimulating hormone and luteinizing hormone β-subunits in the Mongolian gerbil (Meriones unguiculatus)

To examine the molecular basis for efficient superovulation in the Mongolian gerbil, the cDNA sequences of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) beta-subunits were determined and compared with those of other mammals. FSHbeta and LHbeta cDNAs were 1637 and 507bp long, respectively, from the 5'-end to putative polyA sites. The deduced sequences of the FSHbeta and LHbeta precursor proteins were 129 and 141 amino acids in length, respectively. The amino acid sequences of both Mongolian gerbil hormone subunits showed overall similarity to those of other rodents, confirming that the combination of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) should be effective for induction of superovulation in Mongolian gerbils, as in mice and rats. However, the use of hCG might need to be re-evaluated owing to its low homology to rodent LH.
Nonlinear Spatial Evolution of Small Disturbances from Boundary Conditions in Flat Inclined‐Channel Flow

The asymptotic behavior of small disturbances as they evolve spatially from boundary conditions in a flat inclined channel is determined. These small disturbances develop into traveling waves called roll waves, first discussed by Dressler in 1949. Roll waves exist if the Froude number F exceeds 2, which consist of a periodic pattern of bores, or discontinuities. After confirming the instability condition for F > 2 for the linearized equations in the boundary value case, the nonlinear boundary value problem for the weakly unstable region of F slightly larger than 2 is studied. Multiple scales and the Fredholm alternative theorem are applied to determine the evolution of the solution in space. It is found that the solution is dominated by the evolution of the disturbance along one characteristic. The shock conditions governing the asymptotic solution are determined and these conditions are used to determine the approximate shape of the resulting traveling wave from the solution. Both asymptotic and numerical results for periodic disturbances are presented.