cssi/SciSciGPT-SciSciNet huggingface dataset:
Understanding the spread of COVID-19 misinformation on social media: The effects of topics and a political leader's nudge

Abstract The spread of misinformation on social media has become a major societal issue during recent years. In this work, we used the ongoing COVID-19 pandemic as a case study to systematically investigate factors associated with the spread of multi-topic misinformation related to one event on social media based on the heuristic-systematic model. Among factors related to systematic processing of information, we discovered that the topics of a misinformation story matter, with conspiracy theories being the most likely to be retweeted. As for factors related to heuristic processing of information, such as when citizens look up to their leaders during such a crisis, our results demonstrated that behaviors of a political leader, former US President Donald J. Trump, may have nudged people's sharing of COVID-19 misinformation. Outcomes of this study help social media platform and users better understand and prevent the spread of misinformation on social media.
FEMA, Media, or Search Engine? Rumor Validation on Social Media during Hurricanes Harvey and Irma.

Based on data collected from a representative sample of American adults, this study explores social cognitive variables that motivate Americans to validate rumors about Hurricane Harvey and Hurricane Irma on social media. Results indicate that risk perception and negative emotions are positively related to systematic processing of relevant risk information, and systematic processing is significantly related to rumor validation through search engines. In contrast, trust in information is significantly related to validation through official sources and news outlets. These results suggest that ordinary citizens may be motivated to validate rumors on social media, which is an increasingly important issue in contemporary societies. This article is protected by copyright. All rights reserved.
Advanced magnetic X-ray spectro-microscopies to characterize mesoscopic magnetic materials

Abstract This article provides a brief overview of advanced magnetic X-ray spectro-microscopies that are widely used in characterizing mesoscopic magnetic materials. Common to those techniques are various X-ray magnetic dichroism effects that are used as magnetic contrast mechanism. A particular interest is to use those techniques to image the underlying microscopic spin structures in magnetic materials with high spatial resolution and to ultimately resolve their full 3D mesoscale characteristics with elemental sensitivity, as well as their ultrafast dynamics upon excitations with field and current pulses. Recent research examples using various magnetic X-ray spectro-microscopies are presented to showcase their specific features with a focus on imaging novel topological spin textures, such as vortices, skyrmions and Hopfions, which are considered as potential building blocks towards low power, high-speed and high-density magnetic devices that could transform information technologies and potentially be used in biomedical applications. Future developments with magnetic X-ray spectro-microscopies harness the full coherence of next generation X-ray sources and could open the path towards single shot imaging with spatial and temporal resolutions down to fundamental magnetic length and time scales.
Electrophysiological evidence for a general auditory prediction deficit in adults who stutter

We previously found that stuttering individuals do not show the typical auditory modulation observed during speech planning in nonstuttering individuals. In this follow-up study, we further elucidate this difference by investigating whether stuttering speakers' atypical auditory modulation is observed only when sensory predictions are based on movement planning or also when predictable auditory input is not a consequence of one's own actions. We recorded 10 stuttering and 10 nonstuttering adults' auditory evoked potentials in response to random probe tones delivered while anticipating either speaking aloud or hearing one's own speech played back and in a control condition without auditory input (besides probe tones). N1 amplitude of nonstuttering speakers was reduced prior to both speaking and hearing versus the control condition. Stuttering speakers, however, showed no N1 amplitude reduction in either the speaking or hearing condition as compared with control. Thus, findings suggest that stuttering speakers have general auditory prediction difficulties.
Static analyzer of vicious executables (SAVE)

Software security assurance and malware (Trojans, worms, and viruses, etc.) detection are important topics of information security. Software obfuscation, a general technique that is useful for protecting software from reverse engineering, can also be used by hackers to circumvent the malware detection tools. Current static malware detection techniques have serious limitations, and sandbox testing also fails to provide a complete solution due to time constraints. In this paper, we present a robust signature-based malware detection technique, with emphasis on detecting obfuscated (or polymorphic) malware and mutated (or metamorphic) malware. The hypothesis is that all versions of the same malware share a common core signature that is a combination of several features of the code. After a particular malware has been first identified, it can be analyzed to extract the signature, which provides a basis for detecting variants and mutants of the same malware in the future. Encouraging experimental results on a large set of recent malware are presented.
Towards self-managing qos-enabled peer-to-peer systems

Peer-to-peer systems that dynamically interact, collaborate and share resources are increasingly being deployed in wide-area environments. The inherent ad-hoc nature of these systems makes it difficult to meet the Quality of Service (QoS) requirements of the distributed applications, thus having a direct impact on their scalability, efficiency and performance. In this paper we propose adaptive algorithms to meet applications QoS demands and balance the load across multiple peers. These comprise (a) resource management mechanisms to monitor resource loads and application latencies and (b) self-organization algorithms to dynamically select peers that maximize the probability of meeting the applications' soft real-time and QoS requirements. Our algorithms use only local knowledge and therefore scale well with respect to the size of the network and the number of executing applications.
Outcome after Local Recurrence of Osteosarcoma: The St. Jude Children's Research Hospital Experience (1970-2000)

BACKGROUND Despite improvements in therapy for osteosarcoma, approximately 4–10% of patients experience a local recurrence and have a poor prognosis. METHODS The authors analyzed prognostic factors for survival in 26 patients with a local recurrence of osteosarcoma who were treated between 1970 and 2000. RESULTS The initial surgical procedure was amputation in 20 patients (76.9%) and limb salvage in 6 patients (23.1%). The median time from the diagnosis of osteosarcoma to local recurrence was 1.2 years (range, 1.2 months–6.1 years). Eleven patients (42.3%) developed an isolated local recurrence and 15 patients (57.7%) developed local and distant recurrence. The 5-year estimate of postrecurrence survival (PRS) (± 1 standard error) for the 26 patients was 19.2% ± 7.7%. Recurrence ≥ 2 years from the time of diagnosis was found to predict a better outcome (5-year PRS of 50.0% ± 20.4%) compared with earlier recurrence (10.0% ± 5.5%) (P = 0.037). Patients with negative margins after initial surgery were found to have improved survival (5-year PRS of 33.3% ± 13.6%) compared with patients with positive margins (7.1% ± 4.9%) (P = 0.015). Patients who underwent complete surgical resection at the time of recurrence were found to have a better PRS (5-year PRS of 41.7% ± 14.2%) compared with patients who did not undergo surgery (0% ± 0%) (P < 0.001). CONCLUSIONS The prognosis for patients after local recurrence of osteosarcoma is poor. Complete surgical resection at the time of recurrence is essential for survival. Positive margins at the time of initial surgical resection and early recurrence appear to be poor prognostic factors. Cancer 2004. © 2004 American Cancer Society.
Application of Zernike Moments, Independent Component Analysis, and Rough and Fuzzy Classifier for Hand-Written Character Recognition

The paper presents an application of of complex Zernike moments, independent component analysis, rough sets to feature selection and data reduction and rough and fuzzy sets to classifier design.
Language Issues in Mobile Program Security

Many programming languages have been developed and implemented for mobile code environments. They are typically quite expressive. But while security is an important aspect of any mobile code technology, it is often treated after the fundamental design is complete, in ad hoc ways. In the end, it is unclear what security guarantees can be made for the system. We argue that mobile programming languages should be designed around certain security properties that hold for all well-formed programs. This requires a better understanding of the relationship between programming language design and security. Appropriate security properties must be identified. Some of these properties and related issues are explored.
One Path Through Los Alamos

J. Robert Oppenheimer and the American Century . by David C. Cassidy. Pi Press, New York, 2004. 480 pp. $27.95, C$39.95. ISBN 0-13-147996-2. The author offers an account of Oppenheimer's rise and fall accompanied by considerations of social, cultural, and political aspects of the explosive expansion of science in the 20th-century United States.
11 – RNA-Based Disorders of Muscle and Brain

The RNA-based disorders of muscle and brain include myotonic dystrophy type 1 and type 2 (dystrophia myotonica, DM) and fragile X–associated tremor/ataxia syndrome (FXTAS). These disorders reflect an emerging concept in the pathogenesis of genetic disease, namely, that an expanded repeat element within a noncoding portion of an RNA transcript can be directly responsible for a disease phenotype. DM is an autosomal-dominant disorder and the most common form of muscular dystrophy in adults. The DM protein kinase gene (DMPK) and the zinc-finger protein 9 gene ( ZNF9 ) are responsible for DM type1 and DM type 2 respectively. The discovery of the second gene ( ZNF9 ) on a separate chromosome from the DMPK gene, which gives rise to many of the same clinical features, considerably strengthened the argument for an RNA-based mechanism for DM pathogenesis. FXTAS is caused by an RNA-based pathogenesis due to an expanded (noncoding) trinucleotide repeat in the fragile X mental retardation 1 (FMR1) gene. Abnormal expression of the fragile X mental retardation 1 (FMR1) gene leads to both the neurodegenerative FXTAS and fragile X syndrome. FXTAS is a movement disorder that affects some carriers of premutation alleles of the FMR1 gene. The disorder generally presents with progressive intention tremor and/or gait ataxia and Parkinsonism.
Self-organizing thermal fluid flow in fractured crystalline rock: a geochemical and theoretical approach to evaluating fluid flow in the southern Idaho batholith, USA

Thermal springs in the Idaho batholith (USA) discharge at discrete locations along a 50+ km reach of the Middle Fork of the Boise River (MFBR). Recharge water flows through Basin and Range extension fractures where it is heated by the geothermal gradient and ultimately discharges from the damage zone of the trans-Challis faults located near the bottom of the MFBR. Stable isotopes of water, 14C groundwater ages, fracture and fault orientations, fracture volume changes due to chemical evolution, and recharge area calculations suggest that the thermal springs issue from individual hydrothermal systems and that they are self-organizing. Water evolves chemically along flow paths, dissolving feldspars and precipitating secondary minerals. Secondary minerals accumulate in less-efficient fractures and are flushed from the more efficient ones. Flow-area calculations using heat-flow, exponential decay-of-porosity, and curve-intersection methods show that many of the thermal systems extend beyond their immediate topographic watershed, and that some capture water from adjacent watersheds. Geochemical/flow feedback loops that provide a mechanism for self-organization are modeled using PHREEQC, and positive and negative fracture volume changes are calculated. Criteria for identifying self-organizing granitoid thermal groundwater systems are suggested.
Semi-automated patient-specific scalp EEG seizure detection with unsupervised machine learning

Epilepsy is a debilitating neurological disorder for which millions of people worldwide experience seizures. To diagnose these seizures for treatment, a patient typically stays in the hospital for days while a clinical staff must manually screen hours of electroencephalograph (EEG) data for electroencephalographic and behavioral seizures, a very time-consuming, tedious, and subjective process for humans. While decades of research have been dedicated to algorithms for alleviating this clinical procedural burden, there is still room for improvement in seizure detection techniques. Moreover, most seizure detection strategies use supervised machine learning, which requires subjective human involvement for training data. This research examines seizure detection performance for 24 patients using k-means, k-mediod, and hierarchical clustering, a Gaussian mixture model, and a hidden Markov model after using principal component analyses to reduce 45 measures to 2 measures. This work differs from past unsupervised methods, which were tested using very experimentally controlled seizure and non-seizure EEG signals: analyzing continuous EEG spanning 60 seconds pre-seizure to 60 seconds post-seizure in overlapping sliding windows rather than a single point for each seizure and non-seizure epoch. The ‘best’ combination of classifier accuracy, sensitivity, specificity, selectivity, and rejectivity is found with k-means and k-mediod algorithms.
The diagnosis and management of intradiaphragmatic extralobar pulmonary sequestrations: A report of 4 cases

Abstract Background/Purpose Intradiaphragmatic extralobar pulmonary sequestrations (IDEPSs) are a rare subset of bronchopulmonary sequestrations (BPS). We report the largest series of patients with IDEPS and describe the diagnostic and operative challenges associated with this condition. Methods We retrospectively reviewed our experience with fetal and pediatric BPS from 1995 to 2010 to identify patients with IDEPS. Results We identified 27 patients with BPS and 4 patients in whom the masses were within the diaphragm. In 1 patient, the prenatal ultrasound correctly identified the mass as being within the diaphragm itself, whereas the remaining cases were thought to be intraabdominal or had discordant preoperative imaging findings. The diagnosis of an IDEPS proved challenging to make prospectively using prenatal ultrasound, computed tomography, or magnetic resonance imaging. All patients underwent attempted resection. Two cases required a combined laparoscopic and thoracoscopic approach to accurately localize the mass. The postoperative recovery of these patients was uneventful. Conclusions We present the largest reported experience of IDEPS. Because preoperative imaging studies cannot always determine whether a sequestration is intraabdominal, intrathoracic, or intradiaphragmatic, operative planning may pose a challenge. However, the use of minimally invasive approaches can allow exploration of both the thoracic and abdominal cavities with low morbidity.
Autoradiographic study of the effects of pulsed electromagnetic fields on bone and cartilage growth in juvenile rats

Summary-Application of pulsed electromagnetic fields (PEMF) has been used in growth and repair of non-union bone fractures. The similarities between the fibrocartilage callus in non-union bone fractures and the secondary cartilage in the mandibular condyle, both histologically and functionally, lead naturally to study the effects of PEMFs on growth in the condyle. The purposes of this study were: (1) to describe the effects of PEMFs on the growth of the condyle using autoradiography, [‘HI-proline and [3H]thymidine, and (2) to differentiate between the effects of the magnetic and electrical components of the field. Male pre-adolescent Sprague-Dawley rats (28 days old) were divided into three experimental groups of five animals each: (1) PEMF-magnetic (M), (2) PEMF-electrical (E) and (3) control, and were examined at three different times-3, 7 and 14 days of exposure. Each animal was exposed to the field for 8 h per day. Histological coronal sections were processed for quantitative autoradiography to determine the mitotic activity of the condylar cartilage and the amount of bone deposition. The PEMF (magnetic or electrical) had statistically significant effects only on the thickness of the articular zone, with the thickness in the PEMF-M group being the most reduced. Length of treatment was associated with predictable significant changes in the thickness of the condylar cartilage zones and the amount of bone deposition. As the animals aged, less condylar growth was observed and generally the highest mean thicknesses were found in the 3- and 7-day groups; likewise as more bone was deposited, the ‘I-day measurements of proline-band thickness were significantly greater than the 3-day measurements. Thus, the PEMF-M had a negative effect on the chondrogenic layer of the articular zone, but no other chondrogenic or osteogenic effects were noted.
Ernst Kris The Objects of Memory

In 1956, the year before his death, Ernst Kris published a trilogy of papers on memory--"The Personal Myth," "On Some Vicissitudes of Insight in Psychoanalysis," and "The Recovery of Childhood Memories"--and was planning to publish a monograph on the subject. In his papers on memory, by juxtaposing his clinical work with adult patients and his research on very young children, Kris sketched a trajectory of the dynamic relationship between preoedipal ego development and object relations, against the backdrop of psychosexual stages and the defenses that mediate memory. Kris was firmly committed to the premise that "the development of ego functions and object relations . . . are of equal and intrinsic importance." This paper explores how Kris's papers on memory may also be read as delineating his thinking on the role of object relations in infants and young children. In his last paper, the posthumously published "Decline and Recovery in the Life of a Three-Year-Old" (1962), his interest in ego development and object relations shifts to object relations, but the role of memory remains crucial. The paper concludes with some observations about the omissions and distortions that characterize how the history of psychoanalysis is recalled, orally transmitted, and written.
Verification of Selective Adsorption of Polymer on Filler Surface in a Binary Immiscible Polymer Solution Blend Based on Nanoconfinement: Changing the Aggregate Structure and the Surface Character of Carbon Black

The limiting cause of nanoconfinement of rubber molecules for their selective adsorption onto filler surface has been examined by changing: (1) the void size of carbon black aggregates, (2) the ato...
In vivo 13C NMR studies of compartmentalized cerebral carbohydrate metabolism

Localized 13C nuclear magnetic resonance (NMR) spectroscopy provides a unique window for studying cerebral carbohydrate metabolism through, e.g. the completely non-invasive measurement of cerebral glucose and glycogen metabolism. In addition, label incorporation into amino acid neurotransmitters such as glutamate (Glu), GABA and aspartate can be measured providing information on Krebs cycle flux and oxidative metabolism. Given the compartmentation of key enzymes such as pyruvate carboxylase and glutamine synthetase, the detection of label incorporation into glutamine indicated that neuronal and glial metabolism can be measured in vivo. The purpose of this paper is to provide a critical overview of these recent advances into measuring compartmentation of brain energy metabolism using localized in vivo 13C NMR spectroscopy. The studies reviewed herein showed that anaplerosis is significant in brain, as is oxidative ATP generation in glia and the rate of glial glutamine synthesis attributed to the replenishment of the neuronal Glu pool and that brain glycogen metabolism is slow under resting conditions. This new modality promises to provide a new investigative tool to study aspects of normal and diseased brain hitherto unaccessible, such as the interplay between glutamatergic action, glucose and glycogen metabolism during brain activation, and the derangements thereof in patients with hepatic encephalopathy, neurodegenerative diseases and diabetes.
Implantable biohybrid artificial organs

Biohybrid artificial organs encompass all devices which substitute for an organ or tissue function and incorporate both synthetic materials and living cells. This review concerns implantable immunoisolation devices in which the tissue is protected from immune rejection by enclosure within a semipermeable membrane. Two critical areas are discussed in detail: (i) Device design and performance as it relates to maintenance of cell viability and function. Attention is focussed on oxygen supply limitation and how it is affected by tissue density and the development of materials that induce neovascularization at the host tissue-membrane interface; and (ii) Protection from immune rejection. Our current knowledge of the mechanisms that may be operative in immune rejection in the presence of a semipermeable membrane barrier is limited. Nonetheless, recent studies shed light on the role played by membrane properties in preventing immune rejection, and many studies demonstrate substantial progress towards clinically useful implantable immunoisolation devices.
Campus Greening: Behind the Headlines

(2008). Campus Greening: Behind the Headlines. Environment: Science and Policy for Sustainable Development: Vol. 50, No. 1, pp. 6-17.
A possible meiotic function of the peculiar patterns of gene expression in mammalian spermatogenic cells

Abstract This review focuses on the striking differences in the patterns of transcription and translation in somatic and spermatogenic cells in mammals. In early haploid cells, mRNA translation evidently functions to restrict the synthesis of certain proteins, notably protamines, to transcriptionally inert late haploid cells. However, this does not explain why a substantial proportion of virtually all mRNA species are sequestered in translationally inactive free-messenger ribonucleoprotein particles (free-mRNPs) in meiotic cells, since most mRNAs undergo little or no increase in translational activity in transcriptionally active early haploid cells. In addition, most mRNAs in meiotic cells appear to be overexpressed because they are never fully loaded on polysomes and the levels of the corresponding protein are often much lower than the mRNA and are sometimes undetectable. A large number of genes are expressed at grossly higher levels in meiotic and/or early haploid spermatogenic cells than in somatic cells, yet they too are translated inefficiently. Many genes utilize alternative promoters in somatic and spermatogenic cells. Some of the resulting spermatogenic cell-altered transcripts (SCATs) encode proteins with novel functions, while others contain features in their 5′-UTRs, secondary structure or upstream reading frames, that are predicted to inhibit translation. This review proposes that the transcriptional machinery is modified to provide access to specific DNA sequences during meiosis, which leads to mRNA overexpression and creates a need for translational fine-tuning to prevent deleterious consequences of overproducing proteins.
Educational Inequality Between Brothers and Sisters in the United States

For most of the 20th century, American women had, on average, lower educational attainment than men. Researchers often theorize that differential treatment by parents based on children’s genders played a role in this result, but they rarely examine directly whether siblings from the same family were unequally affected. This paper redresses this lacuna by asking two questions: (1) Is the gender gap in educational attainment in the population at large as evident within families? (2) Does parental socioeconomic status (SES) attenuate or exacerbate education differences between sons and daughters? Using the Study of American Families, fixed effects regressions initially suggest that families did favor sons over daughters, but upon closer examination, only high SES families generated higher-educated sons than daughters; low SES families produced equally-educated sons and daughters. These results are contrary to the predictions of gender egalitarianism theory. Additionally, this paper uncovers that if a father had more education than his wife, their son was more likely to surpass his sister educationally, net of family SES; this highlights the reproduction of gendered relations of educational advantage across generations.
Insulin Resistance in Chronic Heart Failure: Relation to Severity and Etiology of Heart Failure

Abstract Objectives. We attempted to assess insulin sensitivity in patients with chronic heart failure (CHF) and its relation to disease severity. Background. Peripheral muscular changes influence the progression of heart failure. This effect may be due to chronic disturbances of insulin and glucose metabolism that affect the energy status of skeletal and myocardial muscle. Methods. We investigated insulin sensitivity in 79 men—38 patients with CHF, 21 patients with angiographic evidence of coronary artery disease without CHF and 20 healthy control subjects—and assessed its relation to disease severity, etiology and hormonal status (all subjects had a similar age and body mass index). Insulin sensitivity was estimated by minimal modeling analysis of the glucose and insulin and profiles during a 0.5-g/kg body weight intravenous glucose tolerance test. Results. Compared with control subjects, patients with CHF had similar mean fasting glucose but increased insulin levels (67 vs. 29 pmol/liter, p Conclusions. CHF is associated with marked insulin resistance, characterized by both fasting and stimulated hyperinsulinemia. Advanced heart failure (in terms of reduced peak Vo2) is related to increased insulin resistance, but this is not directly mediated through ventricular dysfunction or increased catecholamine levels.
Measurement of the properties of single aerosol drops using a new means of suspension

Abstract A new method of suspending a single charged aerosol particle is developed and employed to measure particle parameters including mass, electric charge, composition, radius, molecular kinetic theory effects, etc. The method involves a “Millikan oil drop” phenomenon coupled with an elevation dependent gradient of relative humidity and temperature. The Millikan “balance condition” is stabilized by a “restoring force” based on growth and evaporation. Many specialized experimental problems had to be solved before useful operation of the method could be achieved. These solutions are described in the paper. Application of the method includes studies of the interaction of aerosol particles with a cloud, and bubble bursting mechanisms. Additional phenomena such as aerosol particle discharge mechanisms, diffusiophoretic effects, and drop growth mechanisms might be studied by this method but have not yet been attempted.
Microsurgical Resection of Brainstem, Thalamic, and Basal Ganglia Angiographically Occult Vascular Malformations

Objective To evaluate the clinical results for patients who underwent resection of angiographically occult vascular malformations (AOVMs) of the brainstem, thalamus, or basal ganglia, successfully resected after it exhibited rebleeding and presented to a pial surface. Methods Between January 1990 and May 1998, 56 patients with 57 deep AOVMs underwent 63 operations, at Stanford University Medical Center, to treat AOVMs of the brainstem (42 AOVMs), thalamus (5 AOVMs), or basal ganglia (10 AOVMs). The surgical approach was suboccipital midline (27 operations), far lateral suboccipital (10 operations), transsylvian (9 operations), interhemispheric transcallosal or infracallosal (8 operations), infratentorial supracerebellar (6 operations), or subtemporal (3 operations). Four patients experienced recurrent bleeding from the same lesion after surgical resection, requiring a second operation. One patient required a planned second operation, using a different approach, to completely resect the lesion, and one patient underwent two surgical procedures to resect two separate brainstem AOVMs. One patient initially underwent exploration but not resection of her AOVM, because it did not present to a pial or ependymal surface. The AOVM was successfully resected after it exhibited rebleeding and presented to a pial surface. Results The immediate outcomes after surgery were unchanged for 31 patients (55%), worsened for 16 (29%), and improved for 9 (16%). The long-term outcomes were unchanged for 24 patients (43%), compared with their presenting grade, worse for 3 (5%), and improved for 29 (52%). Patients who had undergone previous radiotherapy or radiosurgery to treat these lesions experienced more difficult postoperative courses, and radiation necrosis was observed for two patients. Conclusion AOVMs of the brainstem, thalamus, and basal ganglia can be safely removed, with a long-term neurological morbidity rate of only 5% and a complete lesion resection rate of 93% after the initial planned resection. The use of cranial base surgical approaches and intraoperative electrophysiological monitoring contributes to successful clinical outcomes.
Pseudogap and incommensurate magnetic fluctuations in YBa2Cu3O6.6

Unpolarized inelastic neutron scattering is used to study the temperature and wave vector dependence of the dynamical magnetic susceptibility, chi "(q, omega), of a well-characterized single-crystal YBa2Cu3O6.6 (T-c = 62.7 K). We find that a pseudogap opens in the spin-fluctuation spectrum at temperatures well above T-c. We speculate that the appearance of the low-frequency incommensurate fluctuations is associated with the opening of the pseudogap. To within the error of the measurements, a gap in the spin-fluctuation spectrum is found in the superconducting state. (C) 1998 Published by Elsevier Science B.V. All rights reserved.
Bremsstrahlung Cross Section of 60-Mev Electrons in Lead

Sixty-Mev electrons from a pulsed betatron passed through lead foils of thicknesses 0.001, 0.005, and 0.015 inch placed in a magnetic cloud chamber. Measurements of approximately 1100 large energy losses gave the differential bremsstrahlung cross section as a function of x-ray energy for the high energy portion of the x-ray spectrum. Corrections were applied for instrumental discrimination and for multiple radiation and ionization energy losses in the foils. While the shape of the top 30 percent of the x-ray spectrum agreed with the theory within experimental uncertainty, the magnitude of the cross section was about 7 percent lower than theory.
Balancing Engagement/Detachment in AIDS‐related Multiple Losses

The process gay persons use to manage the multiple losses and cumulative grief from losing lovers, friends, colleagues and clients to AIDS was explored. Interviews with gay individuals (n = 19) in a large urban area in the West provided data for conceptual coding and comparative analysis. Balancing engagement and detachment was identified as the basic social-psychological process that described how gay individuals struggled to reach an optimal balance in their involvement in the needs of individuals and the community. Four conceptual categories were identified: dysfunctional engagement, functional engagement, functional detachment and dysfunctional detachment. These four categories occur within the contexts of previous life style and redefinition of personal values.
Miniature excitatory postsynaptic currents in bipolar cells of the tiger salamander retina

Abstract The synapse between photoreceptor and bipolar cell is important for at least three reasons: (1) it is the first synapse in the visual pathway; (2) it is the best-known tonic chemical synapse; (3) it has perhaps the most complex and highly organized synaptic morphology in the entire brain. Yet little is known about how neurotransmitter is released from this synapse. We present in this report evidence which suggests that the release of photoreceptor neurotransmitter, presumably glutamate, is probably mediated by clusters of synaptic vesicles which give rise to discrete miniature excitatory postsynaptic currents (MEPSCs) in bipolar cells. The MEPSCs are Ca2+-, osmotic- and CNQX-sensitive, and they share the same reversal potential (near − 3mV) as the glutamate-induced postsynaptic current. The frequency of MEPSCs increases upon presynaptic depolarization, and the mean peak conductance is about 54 pS. MEPSCs exhibit wide variations of amplitudes and durations, probably resulting from random variations of number of synaptic vesicles and the degree of synchronization in individual release clusters.
The highly stereoselective oxidation of polyunsaturated fatty acids by cytochrome P450BM-3

Cytochrome P450BM-3 catalyzes NADPH-dependent metabolism of arachidonic acid to nearly enantiomerically pure 18(R)-hydroxyeicosatetraenoic acid and 14(S),15(R)-epoxyeicosatrienoic acid (80 and 20% of total products, respectively). P450BM-3 oxidizes arachidonic acid with a rate of 3.2 ± 0.4 µmol/min/nmol at 30°C, the fastest ever reported for an NADPH-dependent, P450-catalyzed reaction. Fatty acid, oxygen, and NADPH are utilized in an approximately 1:1:1 molar ratio, demonstrating efficient coupling of electron transport to monooxygenation. Eicosapentaenoic and eicosatrienoic acids, two arachidonic acid analogs that differ in the properties of the C-15-C-18 carbons, are also actively metabolized by P450BM-3 (1.4 ± 0.2 and 2.9 ± 0.1 µmol/min/nmol at 30°C, respectively). While the 17,18-olefinic bond of eicosapentaenoic acid is epoxidized with nearly absolute regio- and stereochemical selectivity to 17(S),18(R)-epoxyeicosatetraenoic acid (≥99% of total products, 97% optical purity), P450BM-3 is only moderately regioselective during hydroxylation of the eicosatrienoic acid Ω-1, Ω-2, and Ω-3 sp3 carbons, with 17-, 18-, and 19-hydroxyeicosatrienoic acid formed in a ratio of 2.4:2.2:1, respectively. Based on the above and on a model of arachidonic acid-bound P450BM-3, we propose: 1) the formation by P450BM-3 of a single oxidant species capable of olefinic bond epoxidation and sp3 carbon hydroxylation and 2) that product chemistry and, thus, catalytic outcome are critically dependent on active site spatial coordinates responsible for substrate binding and productive orientation between heme-bound active oxygen and acceptor carbon bond(s).
The role of meniscal root pathology and radial meniscal tear in medial meniscal extrusion

The purpose of our study was twofold: to better understand the relationship between medial meniscal extrusion (MME) and degenerative joint disease (DJD), and to determine whether a relationship exists between MME and medial meniscal root (MMR) pathology, radial tear and joint effusion. Two hundred and five consecutive MR imaging examinations of the knee were prospectively evaluated, regardless of indication, for the presence and degree of MME, medial compartment marginal osteophytes, medial compartment articular cartilage loss, joint effusion, medial meniscal tear and MMR pathology. MME ≥3 mm was considered abnormal. All studies were performed using a 1.5 T GE Signa MR unit with a quadrature knee coil. The standard protocol included oblique sagittal, coronal and axial imaging. We found a strong association (P<0.0001) between ≥3 mm MME and medial joint line osteophytosis (77%), medial compartment articular cartilage loss (69%), MMR pathology (64%) and radial tear (58%) when compared with knees without these findings. Fifty-one percent of cases with a moderate/large joint effusion had <3 mm MME. We found that 20% (31/155) of patients with minimal or no evidence of DJD had ≥3 mm MME. Of this group, 62% (19/31) had either MMR pathology and/or radial tear, 13% (4/31) had joint effusion as their only abnormality and 6% (2/31) had a normal examination (other than the presence of MME). The remaining 19% consisted of three cases of different types of meniscal tear and three cases of small joint effusions but no other detectable pathology. MME ≥3 mm is strongly associated with DJD, MMR pathology and radial tear. A significant number of cases with no or minimal evidence of DJD (20%) had ≥3 mm MME, suggesting that MME precedes, rather than follows, the development of DJD. We also found that joint effusion was not strongly associated with ≥3 mm MME.
Student Characteristics Related to Achievement in Introductory Psychology Courses.

Summary. Three studies of prediction of academic achievement in introductory psychology courses are reported. The Achiever Personality scale of Fricke's Opinion, Attitude and Interest Survey and Brown and Holtzman's Survey of Study Habits and Attitudes made independent contributions beyond intelligence in the prediction of course grades in two studies. In a third study the Achievement via Independence scale of Gough's California Psychological Inventory was found to contribute to grade prediction.
INTRALUMINAL CHEMOTHERAPY WITH NITROGEN MUSTARD IN SIMULATED CANCER OF THE COLON IN THE RAT.

Summary o 1. Implantation of Walker 256 carcinosarcoma in the cecal pouch of the rat has produced a simulated cecal cancer. 2. Intraluminal use of HN2 as an adjuvant to resection of the cecal pouch Walker 256 carcinosarcoma in the rat has resulted in a reduction from 42 per cent to 20 per cent in the incidence of local suture line recurrence.
The inverse problem in electrocardiography on a spherical model

An inverse problem in electrocardiography, that computes potential distribution on the surface of the heart from potential distribution on the body surface, is studied analytically on concentric spheres model. No symmetry on potential distribution is assumed. The solution to the inverse problem is unique, but inherently very unstable. This paper focuses on two aspects of the inverse problem. First, the magnitude of the instability of the inverse solution is demonstrated by using the exact form of the inverse solution, a regularization method based on parameters directly related to measurable variables is presented, and upper and lower bounds on the error estimate of regularized solution are derived for specific choice of the regularization parameters. Second, the optimal selection of measurements sites for approximation of body surface potentials by means of spherical quadrature is considered. In particular, the problem of optimal distribution of nodes that lead to a quadrature of highest possible degree of exactness is investigated. The study implies that commonly used uniform distributions of nodes are not optimal. Furthermore, it is shown that in certain cases increasing the number of measurements does not improve the accuracy of the inverse solution. This result has been verified by experimental studies published in the literature.
Developmental changes in p-nitrophenol glucuronidation in the gunn rat.

Abstract Non-icteric heterozygous Gunn rats conjugated p-nitrophenol more readily than icteric homozygous rats at 2, 14 and 28 days of age. Heterozygous females, 65–70 days old, also formed the glucuronide more readily than homozygous recessives of the same age, but the results for males were not statistically significant. Both genotypes had comparatively low levels of enzyme activity at birth, with absolute levels and rate of maturation lowest in the icteric homozygous recessives.
Adsorption and surface energy (I): The effect of adsorption on the γ-plot

Abstract Based on the idea that an adsorbing gas atom can interact with any of three different types of surface sites—surface, single ledge, and double ledge sites—each being characterized by discretely different adsorption free energies—a phenomenological theory is developed, governing the shape alterations of the γ-plot due to adsorption from the gas phase. When single and double ledges are preferred sites for adsorption, the theory predicts that an appreciable increase in the curvature of γ-plot can occur as the pressure of the system approaches the characteristic pressures of these sites. At some higher pressure, depending on the relative adsorption energies of single and double ledge sites, a marked decrease in the slope of the γ-plot at the origin of the cusp will occur. When the surface sites are preferred for adsorption the curvature of the γ-plot decreases, and the slope at the origin of the cusp increases as the system pressure approaches the characteristic pressure of the surface site. In addition to, and simultaneously with these changes, each point of the γ-plot will shrink towards the origin of the γ-plot.
AN EXERCISE IN GROUND-WATER MODEL CALIBRATION AND PREDICTION

Abstract. For a classroom exercise, nine groups of graduate students calibrated a numerical ground-water flow model to a set of perfectly observed hydraulic head data for a hypothetical phreatic aquifer. All groups used exactly the same numerical model and identical sets of observed data. After calibration, the students predicted the hydraulic head distribution in the aquifer resulting from a modification in one boundary condition. A quantitative analysis of the results of this calibration-prediction exercise vividly demonstrates some of the difficulties in parameter identification for ground-water flow models. Group predictions differed significantly. Successful prediction was strongly correlated with successful estimation of conductivity values, and was essentially unrelated to successful estimation of aquifer bottom elevations or with the number of trial-and-error simulations required for calibration. Most importantly, success in prediction was unrelated to success in matching observed heads under premodification conditions. In this sense, good calibration did not lead to good prediction.
THE USE OF SURVEYS OF SATISFACTION FOR EVALUATIONS

The use of surveys by cities for planning or evaluation requires attention to several problems identified by users. An assessment of the impact of these issues was made using three surveys by the city of Dallas. It was determined that surveys may be particularly valuable in evaluating service delivery patterns for services which offer delivery agents a high level of discretion. For these services, non-whites reported higher levels of dissatisfaction than whites, a pattern not evident when low discretion services are evaluated. The study also allowed development of specific suggestions regarding the structure of survey questions and the evaluation of services by non-users.
Speed-dependent collisional width and shift parameters in spectral profiles

Derivation of an expression for the spectral profile, termed a speed-dependent Voigt profile (SDVP), taking into account speed-dependent shift and width parameters which are calculated on the basis of an active atom-perturber interaction. It is shown that an analysis of line shapes in terms of simple Voigt profiles (rather than the SDVP) may lead to considerable errors in the determination of characteristic atomic parameters, especially in systems where the perturber to active atom mass ratio is large. It is also noted that the speed-dependent shift leads to an asymmetrical profile, and such a profile is displayed.
A quantitative electron microscopic study of synaptogenesis in the dentate gyrus of the rat

Abstract Synapse development was studied by electron microscopy in the molecular layer of the dentate gyrus of the rat at 4 different ages: 4, 11, 25, and at least 90 days after birth. At 4 days after birth, less than 1% of the synapses seen in the adult are present. Even by 11 days the total number of synapses is still less than 5% of those in the molecular layer of the adult. Synaptogenesis is most active between 4 and 11 days when the total number of synapses approximately doubles every day. Between 4 days and adult the total number of synapses increases by nearly 100-fold in the dendate gyrus.
SU‐E‐T‐67: A Simple Tool for Evaluation of Fiducial Placement for CyberKnife SRS/SBRT Treatment

Purpose: To develop a simple software tool to help determine whether a fiducial placement meets the Spacing and Collinearity criteria for CyberKnife 6D target tracking. Methods: An Excel spreadsheet has been developed for this purpose. The spreadsheet calculates distances and angles for all possible combinations of fiducial triplets based on the fiducial coordinates entered. In general, a group of 4 fiducials forms 4 triplets; a group of 6 fiducials forms 20 triplets. Distance between any two points in 3D space can be calculated easily. Angles formed by lines joining a fiducial triplet are calculated by using the law of cosines. Calculations using scalar product of vectors method are also implemented and used as a redundancy check. Fiducial placement and CyberKnife treatment data from 78 prostate patients were analyzed. Results: The spreadsheet checks each fiducial triplet against the Spacing & Collinearity Thresholds. Distances or angles failed to meet the thresholds are flagged. If none of the fiducial triplets meet the criteria, extra fiducials need to be implanted. Of the 78 patients studied, most patients were implanted with 4 fiducials; seven patients had 3, and twenty patients had 6 fiducials. A total of the 345 fiducials and 600+ triplets were analyzed. The study showed that 72% of the fiducial distances exceeded the 20‐mm Spacing Threshold, and 99% of the fiducial angles exceeded the 15‐degree Collinearity Threshold. Conclusions: We have developed an Excel spreadsheet to verify that a fiducial placement meets the Cyberknife 6D tracking criteria before patient treatment.Analyzing past patient data helps provide guidance on how fiducial placement may be improved. It is important that least one of the fiducial triplets exceed both Spacing and Collinearity Thresholds, as the study has found that there were cases where a fiducial triplet met the Spacing criteria but failed Collinearity criteria, and vice versa.
ERK activation and monosomy 3 are associated with Src expression in uveal melanoma and may serve as biomarkers for Dasatinib treatment

Purpose Uveal melanoma (UM) leads to metastasis in up to 50% of the patients. Patients at risk are readily identified using an array of prognostic markers but an effective treatment is lacking. We recently identified Src as an important tyrosine kinase that conveys MAPK activation in UM. GNAQ/GNA11 mutations are the common denominators of oncogene signalling in UM and Src is a likely downstream kinase. We describe the preclinical analysis of Dasatinib, a known inhibitor or Src kinase, in UM. Methods Eight tumours were removed, cultured and exposed to Dasatinib treatment. proliferation and MAPK signalling were evaluated. Additionally, 36 UM samples were analyzed for Src/ERK signalling, GNAQ/GNA11 mutation status, chromosome 3 and known histological prognostic parameters. Results Growth arrest was observed in 5 of 8 UM cultures and molecular analysis indicated that Dasatinib inhibited MAPK via Src. Treatment efficacy associated with MAPK and Src kinase activity as UM cells with the highest Src activity and MAPK activation displayed the strongest growth inhibition. Furthermore, treatment responses tended to be better in UM cultures with monosomy 3. In the cohort of primary UM, Src expression was highly correlated with MAPK activation and monosomy 3. Conclusion We identified the Src family kinase inhibitor, Dasatinib, as a treatment option for UM. Dasatinib inhibits UM proliferation and may also inhibit UM progression as an association between Src and monosomy 3 was revealed. Consequently, monosomy 3 analysis in tumour tissue may suffice both the prognosis and choice of treatment.