cssi/SciSciGPT-SciSciNet huggingface dataset:
Rapidly Progressive Demyelinating Lesions in a patient with Intravascular B Cell Lymphoma: A Diagnostic Dilemma (P6.110)

Objective: We report a challenging case of intravascular B cell lymphoma(IVBCL) with rapid cerebral demyelination mimicking Acute hemorrhagic encephalomyelitis(AHEM). Background: IVBCL is a rare, fatal disease, often diagnosed on autopsy. It commonly causes multi organ failure involving skin, CNS, Kidneys, GI tract and essentially any organ of the body via infiltration. CNS involvement is rare and can manifest as strokes or demyelinating lesions. Design/Methods: Case Report Results: A 69-year-old African American male presented with altered mental status and frequent falls. His history was significant for ulcerative colitis, hypertension and pulmonary emboli. He was initially worked up for a stroke and found to have small scattered areas of restricted diffusion on MRI brain, suspicious for subacute embolic phenomena. His clinical course progressively worsened and was complicated by seizure like activity, worsening kidney function, fever of unknown origin and anemia. Extensive work up for embolic strokes, acute kidney failure and infection were negative. His lumbar puncture revealed elevated white cell count with lymphocytic predominance and cytology with scant atypical small lymphocytes; viral studies negative. Repeat brain MRI’s showed worsening flair hyper intensities in bilateral white matter, corpus callosum and cortex with micro-hemorrhages. He failed a trial of intravenous steroids for possible immune medicated process. He continued to deteriorate and was made comfort care. Ultimate diagnosis was obtained on brain autopsy, showing lesions in the white matter resembling multiple sclerosis plaques and atypical large lymphoid cells in lumen of small-medium sized blood vessels; immunohistochemically found to be CD20 positive. Conclusions: We should keep a high index of suspicion for possible IVBCL in patient with progressive encephalopathy with multi organ failure and no definite diagnostic results. Early consideration of tissue biopsy and treatment with chemotherapy can improve the clinical outcomes of the patient, however IVBCL has a poor prognosis and is essentially fatal. Disclosure: Dr. Hameed has nothing to disclose. Dr. Kumbham has nothing to disclose. Dr. Gundogdu has nothing to disclose.
Synthesis of telechelic perfluorocarbon functionalized polystyrene and polybutylmethacrylate and characterization of their blends

Abstract Telechelic (T) and end-functionalized (E) perfluorocarbon (RF = C7F15 and C13F27) polystyrene with molecular weights (MWs) of about 15 k and 30 k and the corresponding isobaric polybutylmethacrylate (PS/PBMA) were synthesized by a combination of ATRP and Cu (I) catalyzed click-coupling reactions. Blends (1/1 w/w) of the E− and T-type PS and PBMA having nearly identical MWs of 15 and 30 kDa and RF contents were compared using TEM, AFM, DSC and optical transmittance. The TEMs and AFMs of the isobaric E− and T-type blends showed large increases in compatibility of the T-polymer blends as indicated by its much smaller domain sizes. For instance, at MW of about 30 k the blend of T-type C7F15 functionalized PS and PBMA showed well-defined TEM domains whereas the blend of the C13F27 end-functionalized polymers only showed ill-defined μ-sized domains.
SU-E-T-683: Robustness Analysis of Multiple Filed Optimized IMPT Plans for Head & Neck Patients Treated at MD Anderson Cancer Center

Purpose: Our center’s clinical outcome data so far indicated that excellent local control for the head and neck patients treated using multiple field optimized (MFO) IMPT technique have been achieved. The purpose is to determine the robustness of those IMPT plans and provide the clinician the knowledge of the degree of the robustness which will not compromise the local control and is safe for the normal tissue. Methods: A fast and approximate dose calculation method is developed to calculate the dose for the IMPT plan under different setup and range uncertainties. The dosimetric index evaluated using this method are compared with those calculated using the dose calculation model in TPS. A worst case scenario robustness analysis method is implemented using the fast dose calculation method. 100 head neck plans treated using MFO IMPT were retrospectively analyzed using implemented robustness analysis method. The lowest dose received by 95% target (D95) and the highest dose received by 5% target (D5) of GTV, CTV1, CTV2, CTV3, mean dose of parotid glands, cochlea and brain and the minimum dose in the most radiated 1 cm3 volume (D1cc) of spinal cord and brain stem were compared between nominal plans and plans in the worst case scenario. Results: For GTV, CTV1 CTV2 and CTV3, D95 in worst scenario are lower by 2.08, 4.59, 5.25 and 5.46 Gy than nominal plan, while D5 are higher by 1.14, 0.98, 0.85 and 1.21 Gy. D1cc of brain stem and spinal in worst scenario are higher by 3.37 and 1.95 Gy than nominal plan. The mean dose of parotid glands, cochlea and brain are higher by 3.52, 3.69 and 0.64 Gy respectively. Conclusion: The robustness analysis data from the clinically treated patients enables the clinician to gauge the degree of robustness in their clinical practice when adopting MFO IMPT technique for patient treatment.
THz polarization difference imaging of aqueous targets

This paper describes the basic design, implementation, and testing of a polarization difference imaging system for use on aqueous targets. The ultimate performance limitation of THz imaging in many active areas of research is clutter from surface geometry. While the signal to nose ratio (SNR) of standard THz imaging systems is quite large, the signal to clutter ratio (SCR) often faced in an imaging application is orders of magnitude lower and, in many cases, lower than the contrast to noise (CNR) resulting in imagery where the contrast mechanism of interest does not significantly contribute to the overall observed contrast. To overcome these limitations we develop a system that uses a circularly polarized source and linearly polarized detectors to acquire images of transverse electric (TE) and transverse magnetic (TM) reflectivities of the target over the same field of view. Geletin based tissue mimicking phantoms are fabricated with spatially varying water content and modified with a range of surface topologies and surface roughness. TE and TM images are combined to yield self-calibrated clutter-suppressed images. The resulting image indicates that the imaging field clutter affected both polarization channels nearly equally allowing the system to resolve differences in phantom water content. This design is a step toward windowless THz imaging capability critical for clinical translation where patient imaging is dominated by clutter.
Suppression of literal meanings in L2 idiom processing: Does context help?

Most current idiom processing models acknowledge, after Gernsbacher and Robertson (1999) that deriving an idiomatic meaning entails suppression of contextually inappropriate, literal meanings of idiom constituent words. While embedding idioms in the rich disambiguating context can promote earlier suppression of incompatible literal meanings, idioms embedded in the neutral context, favoring neither their literal nor figurative reading, are likely to become disambiguated much later in the course of their comprehension. The study reported in this paper investigates the role of context in suppressing irrelevant, literal meanings of idioms in the course of their processing by Polish proficient speakers of English. Ambiguous (literally plausible) English idioms were embedded in sentences which were either neutral (i.e., did not bias either the literal or figurative reading of the idiom, e.g., There was no need to add fuel to the fire) or figurative-biased (e.g., The chairman is in a bad mood so do not say anything, as this will only add fuel to the fire) and followed by targets related literally (e.g., HEAT) or figuratively (e.g., WORSE) to idiom meanings and displayed either immediately at idiom offset (0 ms) or after 300 ms. The self-paced reading paradigm was employed, in which participants first read the idiomatic sentences at their own pace and then made a lexical decision, i.e., decided if the displayed target string is a legitimate English word or not. Context was shown to play an important role in suppressing irrelevant meanings, but its effects were modulated by salience (prominence) of idioms’ literal meanings as well as the time that elapsed from the end of the sentence to the display of the target stimulus.
FIx controller : An instrument to automatically adjust inspired oxygen fraction using feedback control from a pulse oximeter

Objective. To develop an instrument to help prevent pulmonaryO2 toxicity, a syndrome that manifests itself in adultintensive care patients. Methods. We designed, built, and tested adevice that controls FIO2 exposure using oxygensaturation measured with a pulse oximeter (SpO2) in a negativefeedback control system. A target SpO2 is designated by theclinician and the system adjusts the FIO2 from amechanical ventilator so as to minimize the difference between the measuredSpO2 and the target. Important elements of the system includea conservative artifact rejection algorithm, a gain-scheduled sampled-dataproportional-integral-derivative (PID) controller, and a safety system toprevent inspired mixtures with undesirably low FIO2 dueto device failure. Results. The control system was tuned in a series ofanimal experiments. Acceptable clinical response of the system was obtainedusing a gain-scheduled controller algorithm whereby the gain of theproportional term of a PID controller was adjusted based on the error signaland measured minute ventilation. Also, the artifact rejection algorithm andsafety systems were successfully tested using simulation. Conclusions.Testing the effectiveness of this instrument will require comparison withmanual control of FIO2 in an appropriately designedtrial.
Effective treatment of refractory intracranial hypertension after traumatic brain injury with repeated boluses of 14.6% hypertonic saline.

Object Normal intracranial pressure (ICP) and cerebral perfusion pressure (CPP) have been identified as favorable prognostic factors in the outcome of patients with traumatic brain injuries (TBIs). Osmotic diuretics and hypertonic saline (HTS) are commonly used to treat elevated ICP in patients with TBI; however, sustained effects of repeated high-concentration HTS boluses for severely refractory ICP elevation have not been studied. The authors' goal in this study was to determine whether repeated 14.6% HTS boluses were efficacious in treating severely refractory intracranial hypertension in patients with TBI. Methods In a prospective cohort study in a neurocritical care unit, adult TBI patients with sustained ICP > 30 mm Hg for more than 30 minutes after exhaustive medical and/or surgical therapy received repeated 15-minute boluses of 14.6% HTS over 12 hours through central venous access. Results Response to treatment was evaluated in 11 patients. Within 5 minutes of bolus administration, mean ICP decrea...
Soil and Water Contamination by Heavy Metals

Soil and water contamination by heavy metals has a major adverse environmental impact. Concern has long existed over the threat of contamination of soil and water resources by heavy metals but has heightened in recent years as more knowledge has been gained about the negative and potentially serious affects that chronic exposure to heavy metals may have on the health of humans and other living organisms. Long-term exposure to lead affects human cognition; cadmium affects kidney, liver, and gastrointestinal tract functioning; and arsenic affects the skin, kidneys, and central nervous system. This article will address terminology, sources, mobility, risk assessment, and management and remediation alternatives for heavy metals in the environment that may contaminate soil and water resources. Keywords: heavy metals; soil; groundwater; environment; contamination; redox potential; sources; mobility; risk assessment
Beliefs About the Etiology of Homosexuality and About the Ramifications of Discovering Its Possible Genetic Origin

Homosexuality is viewed by many as a social problem. As such, there is a keen interest in elucidating the origins of homosexuality among many scholars, from anthropologists to zoologists, from psychologists to theologians. Research has shown that those who believe sexual orientation is inborn are more likely to have tolerant attitudes toward gay men and lesbians, whereas those who believe it is a choice have less tolerant attitudes. The current qualitative study used in-depth, open-ended telephone interviews with 42 White and 44 Black Americans to gain insight into the public's beliefs about the possible genetic origins of homosexuality. Along with etiological beliefs (and the sources of information used to develop these beliefs), we asked respondents to describe the benefits and dangers of scientists discovering the possible genetic basis for homosexuality. We found that although limited understanding and biased perspectives likely led to simplistic reasoning concerning the origins and genetic basis of homosexuality, many individuals appreciated the complex and interactive etiological perspectives. These interactive perspectives often included recognition of some type of inherent aspect, such as a genetic factor(s), that served as an underlying predisposition that would be manifested after being influenced by other factors such as choice or environmental exposures. We also found that beliefs in a genetic basis for homosexuality could be used to support very diverse opinions including those in accordance with negative eugenic agendas.
Vaginal Cuff Recurrence of Endometrial Cancer Treated by Laparoscopic-Assisted Vaginal Hysterectomy

Abstract Background. Laparoscopic-assisted vaginal hysterectomy (LAVH) has been suggested as an alternative to total abdominal hysterectomy (TAH) for the treatment of early endometrial cancer. Although studies have reported good results with equivalent rates of recurrence and survival, the need for use of intrauterine manipulators during the LAVH raises the concern for operative dissemination of tumor cells. Cases. We report three patients with stage I, noninvasive or superficially invasive endometrial cancer with vaginal cuff recurrence within 9 months of treatment by LAVH. Conclusion. While LAVH may be a technically acceptable alternative to TAH for the management of early-stage endometrial cancer, its routine use should be undertaken with caution, as the long-term risks for recurrence and survival have yet to be defined in a randomized, controlled fashion.
Oral recrudescent herpes simplex virus infection

Abstract Objective. The objective of this study is to determine the frequency of involvement of different intraoral sites by oral recrudescent herpes simplex virus in immunocompromised patients and whether keratinized intraoral sites are always affected by this virus. Study design. The records of 30 hospitalized patients who had oral ulcers culture positive for herpes simplex virus were reviewed for the location of oral ulcers, febrile episodes, and medical diagnoses. Results. The data revealed that oral recrudescent herpes simplex virus may involve any intraoral site in immunocompromised patients with nonkeratinized sites representing approximately half of all sites; this is more frequent than has been previously reported. Twenty-six (86.7%) of 30 patients had no evidence of herpes labialis, and 13 (43.3%) of 30 patients were afebrile. Conclusion. It is recommended that all oral ulcers, in immunocompromised patients should be cultured for herpes simplex virus regardless of their location. Early diagnosis reduces patient morbidity because effective treatment in the form of acyclovir is readily available.
Generation and Stability Characterization of Fiber-Based Difference Frequency Generation Tuned Through Controlled Soliton Self-Frequency-Shifting

We present a soliton-tuned source of mid-infrared (MIR) ultrafast laser pulses. Characterization of the source stability is presented through measurements of intensity noise and timing jitter of the pulses used for frequency conversion.
Human Bed Nucleus of the Stria Terminalis Indexes Hypervigilant Threat Monitoring

Background Though a key symptom underlying many anxiety disorders is hypervigilant threat monitoring, its biological bases in humans remain poorly understood. Animal models suggest that anxious processes such as hypervigilant threat monitoring are distinct from cued fear-like responses and mediated by the bed nucleus of the stria terminalis (BNST). Here, we applied psychophysiological and neuroimaging methodologies sensitive to sustained arousal-based responses to test the role of the human BNST in mediating environmental threat monitoring, a potential experimental model for sustained anxiety symptoms. Methods Healthy participants (n = 50) with varying trait anxiety performed an environmental threat-monitoring task during functional magnetic resonance imaging where a stimulus line continuously fluctuated in height, providing information relevant to subsequent risk for electric shocks. Skin conductance was collected in a separate cohort (n = 47) to validate task-evoked modulation of physiological arousal. Results A forebrain region consistent with the BNST showed greater overall recruitment and exaggerated tracking of threat proximity in individuals with greater anxiety. The insular cortex tracked threat proximity across all participants, showed exaggerated threat proximity responding with greater anxiety, and showed enhanced recruitment when threat proximity was ostensibly controllable. Conclusions Activity in the BNST and insula continuously monitored changes in environmental threat level and also subserved hypervigilant threat-monitoring processes in more highly trait anxious individuals. These findings bridge human and animal research informing the role of the BNST in anxious-related processes. In addition, these findings suggest that continuous functional magnetic resonance imaging paradigms offer promise in further elucidating the neural circuitries supporting sustained anticipatory features of anxiety.
FATIGUE LIFE PREDICTION OF MICROSTRUCTURES

The formation and early growth of fatigue cracks in the high cycle fatigue regime is influenced by microstructuctural features such as grain size and morphological and crystallographic texture. However, most fatigue models do not predict the influence of the microstructure on early stages of crack formation, or they employ parameters that should be calibrated with experimental data from specimens with microstructures of interest. These post facto strategies are adequate to characterize materials, but they are not fully appropriate to aid in the design of fatigue-resistant engineering alloys. This paper presents a modeling framework that facilitates relative assessment of fatigue resistance among different microstructures. The scheme employs finite element simulations that explicitly render the microstructure and a methodology that estimates transgranular fatigue growth for microstructurally small cracks on a grain-by-grain basis, including consideration of growth within grains (embedded analytically) and stress redistribution as the cracks extend. The methodology is implemented using a crystal plasticity algorithm in ABAQUS and calibrated to study fatigue crack initiation of a bimodal grain size distribution found in RR1000 powder processed Ni-base superalloys for turbine disk applications.Copyright © 2012 by ASME
Neocortex Patterning by the Secreted Signaling Molecule FGF8

A classic model proposes that the mammalian neocortex is divided into areas early in neurogenesis, but the molecular mechanisms that generate the area map have been elusive. Here we provide evidence that FGF8 regulates development of the map from a source in the anterior telencephalon. Using electroporation-mediated gene transfer in mouse embryos, we show that augmenting the endogenous anterior FGF8 signal shifts area boundaries posteriorly, reducing the signal shifts them anteriorly, and introducing a posterior source of FGF8 elicits partial area duplications, revealed by ectopic somatosensory barrel fields. These findings support a role for FGF signaling in specifying positional identity in the neocortex.
Neighborhood quality and climate as factors in U.S. net migration patterns 1974-76

Two determinants of net migration into [U.S.] Standard Metropolitan Statistical Areas in 1974-76 are established. First using objective indices of the quality of neighborhoods (NQL) such as crime rates earlier research failed to find a significant relation between NQL and migration. Using OLS regressions [the authors] find that variations in perceived NQL have a significant effect on net migration. [The] measure of perceived NQL is based on newly available Census survey data. An appendix contains...NQL indices for 57 SMSAs. Second [the authors] find summer humidity in addition to winter temperature has a highly significant effect on migration patterns. (EXCERPT)
On the welfare effects of allowing unlimited renegotiation in agency relationships

We study renegotiation in an agency setting where the number of offers and accept/reject decisions parties can make is potentially unlimited. Thus any contract, either on or off the equilibrium path, may be subject to possible renegotiation. We first show that the principal will not be able to gain complete access to the agent’s private information with unlimited renegotiation, unlike when the potential number of renegotiations is finite. Rather the agent either employ a randomized reporting strategy or do not to report at all. We then identify conditions under which expected allocations are most efficient with the contract that induces no agent communication. More significantly, by doing so we also identify conditions under which the parties are made strictly worse off by committing to end renegotiation after a fixed number of rounds.
Blanchot/Levinas: Interruption (On the Conflict of Alterities)

Etude de la question heideggerienne du lien entre le langage et l'alterite chez Levinas et Blanchot. Definissant le rapport a autrui dans l'experience du langage comme une interruption de l'identite de soi, l'A. montre que la relation ethique etablie par Levinas, a partir de l'idee d'une pluralite de langages, correspond chez Blanchot a la place pre-originale du langage poetique qui ouvre la voie a cet entre-temps de l'amitie
Fat, hydration condition, and moult of Steppe Buzzards Buteo buteo vulpinus on spring migration

Physical condition of migrating Steppe Buzzards Buteo buteo vulpinus was determined during spring migration at Elat, southern Israel, 1984–1988. An index based on measurements of body mass, wing-length and culmen was used to estimate fat content, based on fat extraction from nine buzzards. In addition, hydration condition was measured in 1988 and moult was checked in 1985–1988. More immatures (1001) than adults (459) were trapped, and a greater percentage of immatures (19.8%) than adults (8.4%) was retrapped during the same season. Adults had significantly greater fat reserves (4.5% of body mass) than immatures (3.8%). Most adults were in some stage of interrupted moult: however, active primary moult was noted only in immatures (10%). These findings suggest that different age groups use different migration strategies. Most of the buzzards trapped in this study could not have completed their entire migration using only stored fat: thus, hunting was probably necessary to replenish their energy reserves. No indication of water stress was found in the spring of 1988.
Teaching Privacy: What Every Student Needs to Know (Abstract Only)

Although frequent stories in the popular media have raised awareness about online privacy, most young people do not have a very good handle on what the specific issues are, nor the practical steps they can take to manage them. Teachers recognize that all their students' from future engineers to those totally bored by science need a realistic understanding of how online privacy works, so they can protect themselves online. In fact, the latest CS curricular recommendations include privacy but there is no comprehensive set of field-tested teaching materials. To address this, we are developing TROPE (Teachers' Resources for Online Privacy Education), a set of classroom-ready teaching materials (teachingprivacy.org). TROPE will provide educators with lesson modules, interactive demonstrations, and a teachers' guide, so they can readily integrate privacy into high school and college classes. Our goal for this workshop is twofold. First, we will introduce educators to TROPE and provide guidance on how they can cover privacy-related topics in their classrooms without being subject-matter experts. Second, we will solicit feedback and on-the-ground stories; by gaining a better understanding of specific problems faced by educators and students, we can increase TROPE's utility to teachers. We will provide teachers with up-to-date technical information about online privacy, including relevant highlights from our research; hands-on activities illustrating principles of online privacy; and an overview of the materials we are creating for TROPE. This will be an interactive workshop, driven by participants' questions, experiences, and interests. For CS educators at all levels; laptop or tablet recommended.
Mutant SOD1 causes motor neuron disease independent of copper chaperone–mediated copper loading

Mutant SOD1 causes motor neuron disease independent of copper chaperone–mediated copper loading
Turning towards the novel in a post-planetary moment

There was a man and a dog too this time. Two beasts, counting Old Ben, the bear, and two men, counting Boon and Hoggenbeck, in whom some of the same blood ran which ran in Sam Fathers, even though ...
The INGRES Tutorial as a tool in teaching database theory (or, I can't believe it's not training)

The course in database principles is an example of a course in the computer science curriculum in which a balance is sought between theory and applications. With some exceptions, most computer science majors at the author's university prefer material which is oriented towards what they view as practical applications. At best, they tolerate the theoretical component of their courses. In particular, many who enroll in the database course hope to acquire expertise in particular software. One of the course projects has managed to finesse this prejudice by hiding some theoretical ideas in the benign cloak of an application.
The Cockroaches of Paterson: A Study of Labor Conflict and Technological Change:

A technological innovation based on a revival of the seventeenth century putting-out system dominated the Paterson broad-silk weaving industry during the 1920s and 1930s in the form of the family s...
Single stage near total resection of massive pediatric head and neck plexiform neurofibromas

Summary Objective Plexiform neurofibromas of the head and neck in neurofibromatosis type 1 (NF 1) carry a significant morbidity with substantial loss of function as well as significant cosmetic problems. We describe our experience with early aggressive surgical intervention in such patients in order to avert these problems. Methods Retrospective review of four consecutive pediatric patients with massive head and neck plexiform neurofibromas who underwent single stage near total or sub-total tumor resections. Results All four patients were referred for obstructive airway symptoms. Each patient experienced complete relief of symptoms and return of function without additional neurological deficits. There were two minor complications and no major complications of surgical resection. There have been no recurrences to date, with follow-up ranging from 15 months to 5 years. Conclusions Early surgical intervention of NF 1 patients with plexiform neurofibromas of the head and neck with a goal of near total resection avoids the loss of function associated with these tumors, such as tracheostomy dependence, swallowing difficulty, and speech problems, and prevents the inexorable progression of substantial cosmetic deformity. Successful management of these complex lesions requires detailed preoperative planning, advanced surgical techniques, and vigilant postoperative care.
On ergodic theorem for a Banach valued random sequence

In this paper we shall deal with a probability space ( S , Σ, P ), a separable Banach space X having its strong dual X* and a strictly stationary random sequence defined as in [7], where are X -valued, Gelfand-Pettis (weakly) integrable [6], [9], and strongly measurable random variables. In the case when Y k 's are Bochner (strongly) integrable random variables one can find the ergodic theorem for such a sequence and, with respect to strong convergence in X , in the papers [7], [8].
Nicotine discrimination and self-administration in humans as a function of smoking status

Nicotine’s discriminative stimulus effects may be critical to understanding reinforcement of tobacco smoking. It is not known whether regular nicotine exposure produces tolerance or sensitivity to these effects. In this study, male and female smokers (n = 11) and never-smokers (n = 10) were trained to discriminate 20 μg/kg nicotine by nasal spray from placebo (0) on day 1. On day 2, both groups were tested on generalization of this discrimination across intermittent presentations of 0, 3, 6, 12, and 20 μg/kg nicotine in random order. Quantitative and quantal behavioral discrimination tasks, used in previous research, were employed. On day 3, subjects were instructed to self-administer sprays from the 20 μg/kg nicotine versus 0 bottles in a concurrent-choice procedure. All but one subject (female smoker) learned reliably to discriminate 20 μg/kg nicotine from placebo (≥ 80% correct) on day 1. Nicotine-appropriate responding on day 2 was attenuated in smokers versus never-smokers at 20 μg/kg on the quantitative task and at 12 μg/kg on the quantal task, suggesting tolerance. There was no difference in responding at other doses. Smokers also showed attenuated responses on the subjective measure of “head rush”, which was associated with discrimination responding in both groups. Nicotine self-administration was significantly greater in smokers versus never-smokers, who self-administered nicotine below chance levels, and was inversely related to discrimination behavior in never-smokers but unrelated in smokers. Women smokers showed less change in nicotine-appropriate responding across generalization doses, reported less confidence in discriminating training doses during acquisition on day 1, and tended to self-administer less nicotine on day 3. These results indicate that smokers may become tolerant to the discriminative stimulus effects of nicotine, perhaps promoting increased use.
Site of conduction delay and electrophysiologic significance of first-degree atrioventricular block in children with heart disease.

Abstract Associated electrophysiologic abnormalities and site of delay were studied in 20 patients, aged 1.5 to 16.5 years, with congenital heart disease and first-degree atrioventricular (AV) block (PR interval above the 98th percentile for age and heart rate). Eight of the 20 patients with first-degree AV block were studied after 1 or more cardiovascular operations. Refractory periods of the atrium, AV node, His-Purkinje system and ventricle were determined. As a further test for AV nodal integrity, rapid atrial pacing was performed and the cycle at which Wenckebach periodicity occurred was noted. Four groups were identified. Group I included 4 patients (20%) with intraatrial conduction delay (long PA interval). Three patients had depressed sinus nodal function and 1 had depressed AV nodal function. Group II included 7 patients (35%) with AV nodal delay (long AH interval). One patient had sinus nodal depression and 2 had AV nodal depression (prolonged AV nodal refractory period or Wenckebach at a long paced cycle length). Group III included 3 patients (15%) with His-Purkinje delay (long HV interval). Measured functions were normal in all patients. Group IV included 6 patients (30%) with normal or high normal intracardiac intervals with long PR. One patient had sinus nodal dysfunction, 2 patients had long atrial refractory periods, 1 had AV nodal depression; 2 had long refractory period of the His-Purkinje system, and 1 had long ventricular refractory period. Atrial flutter was induced in 1 patient. In this heterogenous group of children, the most frequent single site of delay causing first-degree AV block was the AV node, but almost as many had a long PR interval as a result of high normal values at various sites (PA, AH and HV). There was poor correlation with other electrophysiologic abnormalities and the site of conduction delay. Sinus nodal dysfunction was found almost exclusively in patients with intraatrial delay (group I). There was a greater frequency of abnormalities, particularly AV nodal dysfunction, among patients who had undergone operation. Despite first-degree AV block and associated electrophysiologic abnormalities, these patients had no clinical progression of conduction disease during a mean follow-up of 32 months (range 1 month to 5.5 years).
Do cysteine 230 and lysine 238 of biotin carboxylase play a role in the activation of biotin

Biotin carboxylase from Escherichia coli catalyzes the ATP-dependent carboxylation of biotin and is one component of the multienzyme complex acetyl-CoA carboxylase, which catalyzes the committed step in long-chain fatty acid synthesis. For the carboxylation of biotin to occur, biotin must be deprotonated at its N1' position. Kinetic investigations, including solvent isotope effects and enzyme inactivation by N-ethylmaleimide, suggested a catalytic role for a cysteine residue and led to the proposal of a mechanism for the deprotonation of biotin. The proposed pathway suggests a catalytic base removes a proton from a nearby cysteine residue, forming a thiolate anion, which then abstracts the proton from biotin. Inactivation studies of pyruvate carboxylase, which has an analogous mode of action to biotin carboxylase, suggests the catalytic base in this reaction is a lysine residue. Using the crystal structure of biotin carboxylase, cysteine 230 and lysine 238 were identified as the likely active-site residues that act as this acid-base pair. To test the hypothesis that cysteine 230 and lysine 238 act as an acid-base pair to deprotonate biotin, site-directed mutagenesis was used to mutate cysteine 230 to alanine (C230A) and lysine 238 to glutamine (K238Q). Mutations at either residue resulted in a 50-fold increase in the K(m) for ATP. The C230A mutation had no effect on the formation of carboxybiotin, indicating that cysteine 230 does not play a role in the deprotonation of biotin. However, the K238Q mutation resulted in no formation of carboxybiotin, which showed that lysine 238 has a role in the carboxylation reaction. N-Ethylmaleimide was found to inactivate the C230A mutant but not the K238Q mutant, suggesting that N-ethylmaleimide is reacting with lysine 238 and not cysteine 230. The pH dependence of N-ethylmaleimide inactivation revealed that the pK value for lysine 238 was 9.4 or higher, suggesting lysine 238 is not a catalytic base. Thus, the results suggest that cysteine 230 and lysine 238 do not act as an acid-base pair in the deprotonation of biotin.
Electron–phonon induced pairing and its limits for superconducting systems

Abstract The role of electron–phonon induced pairing is discussed with emphasis on its successes and failures when used within conventional theoretical frameworks/approaches to explain the existence of superconductivity. A historical background will be given followed by examples of applications for specific material systems using recent theoretical methods. A broad range of superconductors will be considered including the systems based on Fe.
Cooperative Courtship: Helping Friends Raise and Raze Relationship Barriers

Do people help each other form romantic relationships? Research on the role of the social environment in relationship formation has traditionally focused on competition, but this article investigates novel patterns of cooperation within courtship interactions. Drawing on a functional/evolutionary perspective, women are predicted to cooperate primarily in building romantic thresholds and barriers; men are predicted to cooperate primarily in achieving romantic access. In support of these predictions, four studies reveal that people consistently perceive cooperation, report cooperative behavior, and make cooperative decisions in romantic situations. People also provide the opposite pattern of help to opposite-sex friends from that provided to same-sex friends, suggesting that assistance is flexibly tuned to differences in the romantic selectivity of recipients. Cooperative courtship is revealed to be a commonly used set of mating strategies by which people functionally tailor aid to promote both their own an...
LASER CHEMISTRY IN MOLECULAR CRYSTALS

AbstractThe use of mixed molecular crystals at low temperatures as systems in which to study laser inducedphotochemistry is discussed. As specific examples the photochemistry of s- tetrazine and its dimethylderivative is treated. These molecules have previously been used as guests in host molecular crystals toillustrate solid state laser isotope separation and photochemical hole burning. The results presented hereindicate that the low temperature tetrazine photochemistry may involve the sequential absorption of two photons. With this in mind, we are able to suggest a useful method of finding other materials for isotopeseparation and photochemical hole burning.IntroductionMolecular crystals provide ideal host systems for high resolution spectroscopic studies of substitutionallyincorporated guest molecules. Absorption and emission spectra at liquid helium temperatures can be verysharp,(1) and in many cases the molecules assume known orientations with respect to the host crystal axes.(2)These features of mixed molecular crystal spectra have been successfully exploited to investigate the excitedstates of a variety of organic molecules.In this paper we will discuss a mixed molecular crystal system in which the sharp spectral lines areselectively excited with the intense monochromatic radiation from a tunable dye laser, with the intent ofinvestigating the resulting photochemistry. Laser induced chemistry in mixed molecular crystals, as we willillustrate, promises to yield much valuable information on the mechanisms of photochemical reactions.
Economic and demographic factors affecting US demand for lunch meats

AbstractConsumer demand analyses of meats have seldom included processed meats, particularly lunch meats. In this study, we examine retail lunch meat data from Nielsen 2006 Homescan. The objective of this study is to determine the impact of retail prices, expenditure, and demographic variables on eight lunch meat products. A censored AIDS model is used to estimate the demand for lunch meat products. Results reveal that own-price elasticities are elastic for all lunch meat categories. The expenditure elasticities are elastic for four lunch meat products and inelastic for the remaining products and demographic variables have statistically significant impacts on lunch meat purchases.
A crossed molecular beams study of the reaction of dicarbon molecules with benzene

Abstract We conducted the reaction of dicarbon molecules in their electronic ground, C 2 ( X 1 Σ g + ) , and first excited state, C 2 (a 3 Π u ), with benzene, C 6 H 6 (X 1 A 1g ). The phenylethynyl radical (C 6 H 5 CC; X 2 A′) and atomic hydrogen were inferred to be the reaction products under single collision conditions. The reactions were indirect via short-lived C 8 H 6 intermediates which decomposed via atomic hydrogen elimination without exit barrier (singlet surface) and via a tight exit transition state (triplet surface). Our experiments suggest that the phenylethynyl radical can be likely formed via bimolecular reactions involving dicarbon molecules with benzene in extreme environments such as circumstellar envelopes of carbon stars, planetary nebulae, and combustion flames.
Interaction, Reported and Observed: The Case of One Local Union

The observation is neither profound nor original that, over the past two to three decades, behavioral scientists have placed increasingly heavy reliance on the questionnaire survey as a principal means of data collection. The reasons for this are obvious and compelling. The method is relatively inexpensive; once the questionnaire is constructed, no great skills are involved in its administration; by means of questionnaires, data may be rapidly, efficiently, and uniformly gathered from large and representative populations. And, most important, the combination of the standard stimulus, accurate sampling procedures, and ever more sophisticated techniques for analysis of quantitative data, offers behavioral scientists their most reasonable approximation, for large numbers of respondents, to the classic experimental model, without which, no researcher may lay claim to hard and fast "proof" of any scientific proposition.
Duplication of the A17L Locus of Vaccinia Virus Provides an Alternate Route to Rifampin Resistance

Specific gene duplications can enable double-stranded DNA viruses to adapt rapidly to environmental pressures despite the low mutation rate of their high-fidelity DNA polymerases. We report on the rapid positive selection of a novel vaccinia virus genomic duplication mutant in the presence of the assembly inhibitor rifampin. Until now, all known rifampin-resistant vaccinia virus isolates have contained missense mutations in the D13L gene, which encodes a capsid-like scaffold protein required for stabilizing membrane curvature during the early stage of virion assembly. Here we describe a second pathway to rifampin resistance involving A17, a membrane protein that binds and anchors D13 to the immature virion. After one round of selection, a rifampin-resistant virus that contained a genomic duplication in the A17L-A21L region was recovered. The mutant had both C-terminally truncated and full-length A17L open reading frames. Expression of the truncated A17 protein was retained when the virus was passaged in the presence of rifampin but was lost in the absence of the drug, suggesting that the duplication decreased general fitness. Both forms of A17 were bound to the virion membrane and associated with D13. Moreover, insertion of an additional truncated or inducible full-length A17L open reading frame into the genome of the wild-type virus was sufficient to confer rifampin resistance. In summary, this report contains the first evidence of an alternate mechanism for resistance of poxviruses to rifampin, indicates a direct relationship between A17 levels and the resistance phenotype, and provides further evidence of the ability of double-stranded DNA viruses to acquire drug resistance through gene duplication. IMPORTANCE The present study provides the first evidence of a new mechanism of resistance of a poxvirus to the antiviral drug rifampin. In addition, it affirms the importance of the interaction between the D13 scaffold protein and the A17 membrane protein for assembly of virus particles. Resistance to rifampin was linked to a partial duplication of the gene encoding the A17 protein, similar to the resistance to hydroxyurea enabled by duplication of the gene encoding the small subunit of ribonucleotide reductase and of the K3L gene to allow adaptation to the antiviral action of protein kinase R. Gene duplication may provide a way for poxviruses and other DNA viruses with high-fidelity DNA polymerases to adjust rapidly to changes in the environment.
A three-dimensional WKB approximation for the dirac equation

A three-dimensional semiclassical approximation is developed and used to describe the precession of the polarization of a Dirac particle in an electromagnetic field and the dynamical and kinematical origin of the precession clearly exhibited. The rate of change of the longitudinal polarization is calculated and shown to arise entirely from that change in orientation of the classical trajectory due to the influence of the electric field alone. The effect of the anomalous moment is exhibited by consideration of the Dirac equation modified by inclusion of a Pauli moment term.
Invariants, Boolean algebras and ACA$_{0}^{+}$

The sentences asserting the existence of invariants for mathematical structures are usually third order ones. We develop a general approach to analyzing the strength of such statements in second order arithmetic in the spirit of reverse mathematics. We discuss a number of simple examples that are equivalent to ACA 0 . Our major results are that the existence of elementary equivalence invariants for Boolean algebras and isomorphism invariants for dense Boolean algebras are both of the same strength as ACA + 0 . This system corresponds to the assertion that X (ω) (the arithmetic jump of X) exists for every set X. These are essentially the first theorems known to be of this proof theoretic strength. The proof begins with an analogous result about these invariants on recursive (dense) Boolean algebras coding 0 (ω) .
The neutrino: from poltergeist to particle

The historical aspects leading to the discovery of the neutrino are discussed. {copyright} 1996 The Novel Foundation.
Polynomial-time algorithm for the orbit problem

The accessibility problem for linear sequential machines [12] is the problem of deciding whether there is an input x such that on x the machine starting in a given state q1 goes to a given state q2. Harrison shows that this problem is reducible to the following simply stated linear algebra problem, which we call the "orbit problem":Given (n, A, x, y), where n is a natural number and A, x, and y are nxn, nx1, and nx1 matrices of rationals, respectively, decide whether there is a natural number I such that Aix=y.He conjectured that the orbit problem is decidable. No progress was made on the conjecture for ten years until Shank [22] showed that if n is fixed at 2, then the problem is decidable. This paper shows that the orbit problem for general n is decidable and indeed decidable in polynomial time. The orbit problem arises in several contexts; two of these, linear recurrences and the discrete logarithm problem for polynomials, are discussed, and we apply our algorithm for the orbit problem in these contexts.