cssi/SciSciGPT-SciSciNet huggingface dataset:
A Tool for Evaluating Session-Level Integration in Medical Education

Integration in medical education is generally defined as a multidisciplinary approach to the delivery of the basic and applied sciences. In medical education, the number of integrated curricula reported has steadily increased, yet the degree of integration often varies. The purpose of this study was to evaluate a tool for medical educators to assess and improve the level of trans-disciplinary integration within an individual academic session. The Session Integration Tool (SIT) is an analytic, developmental rubric that allows the user to assess session-level integration given three criteria: development, delivery, and outcomes. To evaluate the tool, participants utilized the SIT to assess two exemplar case studies, and then their own educational session. A survey was administered to assess user satisfaction along with the instrument’s usefulness and impact on practice. Statistical analysis demonstrated a significant difference between user scores of the exemplar case studies for each paired set of criteria (p < 0.000) and for total scores (p = 0.043). Users also successfully used the instrument to assess their own session. The SIT was highly rated by users in terms of satisfaction, usefulness, and impact on practice, with average scores for each category ranging from agree to strongly agree. The SIT has statistical validity in its ability to discriminate between varied levels of integration. Users found the SIT to be useful and impactful for medical education practice and believe it to support peer- and self-assessment of curricular integration. The SIT is a useful, evidence-based, theory grounded tool for assessing session-level integration.
Investigating Viewership of Season 3 of 13 Reasons Why" and the Mental Wellness of Adolescents: Partially Randomized Preference Trial."

Background: A conflicting body of research suggests that additional investigation is needed to understand how globally watched television shows featuring social and mental health issues, such as 13 Reasons Why, might affect adolescents’ mental wellness. Objective: This study aims to investigate adolescents’ viewership of the third season of the Netflix drama 13 Reasons Why (13RW-3) and their engagement with show-related content, paying special attention to mental health outcomes and conversational partners. Methods: A panel-based research platform operated by the National Opinion Research Center at the University of Chicago recruited 157 adolescents aged 13 to 17 years from its nationally representative pool of participants. Participants answered questions about how they discussed and learned about social and mental health issues portrayed in 13RW-3 (eg, masculine role pressure and sexual assault) and questions about mental wellness (eg, mental health self-efficacy and depression). After the participants completed the survey (T1), they were directed to either watch 13RW-3 as it aired for the first time (intervention group) or not watch 13RW-3 (control group). Approximately one month later (T2), all the participants were asked to complete the postsurvey. Additional survey questions about conversational partners, information seeking because of watching the show, and use of show-related content were included in the intervention postsurvey. Results: Our sample (N=157) was 52.2% (n=82) female and 54.8% (n=86) White, with a mean age of 14.99 (SD 1.4) years. At T2, viewers of 13RW-3 spoke about suicide significantly more frequently than nonviewers (P=.007). From T1 to T2, viewers increasingly discussed issues explored by 13RW-3 (P=.002), especially suicide, mental health, and bullying. Adolescent viewers were most likely to speak with friends, and parents were the second most commonly named. Two variables emerged as consistent moderators of conversational choices—having depressive symptoms and being impacted by sexual assault. There was no association between conversational frequency and information seeking around social and mental health issues, and neither mental health self-efficacy scores nor masculine role pressure scores significantly differed between viewers and nonviewers at T2. Conclusions: Viewing 13RW-3, a globally watched television show featuring social and mental health issues, led to adolescent conversations and information searches about topics explored by the show. Depressive symptoms and the impact of sexual assault moderated several relationships, guiding participants toward engaging with certain issues and seeking out specific conversational partners. As 13RW-3’s stories drove conversations—and story-driven conversations can raise awareness, reduce stigma, shift attitudes, normalize certain behaviors, and strengthen supportive relationships—potential wellness implications for television shows featuring social and mental health issues are considerable.
Postoperative respiratory complications after adenotonsillectomy in children with obstructive sleep apnea.

Abstract Objective Children with obstructive sleep apnea are considered high risk for postoperative respiratory complications, but opinions differ regarding the polysomnography (PSG) criteria that suggest the need for postoperative admission. Our objective was to determine if otherwise healthy children age ≥3 years with an apnea-hypopnea index (AHI) Methods Case series with chart review of children age 2) who underwent adenotonsillectomy (T&A) between January 2013 and August 2019. Data collected included patient demographics, medical history, comorbidities, PSG results, operative details, length of stay, intraoperative and postoperative respiratory complications and management. Potential predictors of respiratory complications were evaluated using chi-square/Fisher's exact test and 2-tailed unpaired t tests with the Bonferroni adjustment for multiple comparison artifact. The percentages of healthy children age ≥3 years who were discharged on the day of surgery at various PSG cutoffs were calculated. Results Of the 560 children, mean (SD) age was 6.4 (3.7) years, 318 (56.8%) were male, 438 (78.2%) were African American, 243 (43.4%) were obese, 16 (2.9%) had Down Syndrome and 12 (2.1%) had sickle cell disease. Median (range) AHI was 12.3 (2–145). Fifteen children (2.7% [95% CI 1.3, 4.0]) had an intraoperative or postoperative respiratory complication. Minor complications including mild desaturation, stridor, croupy cough, and laryngospasm occurred in 9 patients and did not prolong the planned ambulatory or hospital stay. Of the 6 children with more severe complications including prolonged desaturation, tachypnea, atelectasis, intercostal retraction and obstructive apnea requiring continuous positive airway pressure, all were planned admissions based on age, severe sleep study indices (AHI ≥ 24 or oxygen saturation nadir Conclusions This study demonstrates a low risk of respiratory complications after T&A. Otherwise healthy children age ≥3 years with AHI
What the Jackson Heart Study Has Taught Us About Diabetes and Cardiovascular Disease in the African American Community: a 20-year Appreciation.

The burden of cardiometabolic diseases such as cardiovascular disease (CVD) and type 2 diabetes (T2D) is pronounced among African Americans. Research has shown that behavioral, social, metabolic, psychosocial, and genetic risk factors of CVD and T2D are closely interwoven. Approximately 20 years ago, the Jackson Heart Study (JHS) was established to investigate this constellation of risk factors. Findings from neighborhood studies emphasize the importance of social cohesion and physical environment in the context CVD and T2D risk. Socioeconomic status factors such as income and education were significant predictors for CVD and T2D. Behavioral studies indicate that modifiable risk factors such as smoking, physical inactivity, lack of sleep, and poor nutrition are associated with CVD risk and all-cause mortality. Mental health also was found to be associated with CVD and T2D. Genetic influences are associated with disease etiology. This review summarizes the joint contributions of CVD and cardiometabolic risk factors in an African American population.
Hirschsprung Disease and Eating Disorders

Hirschsprung disease (HD) is a congenital disease which occurs in about 1 in 5000 births and is most commonly diagnosed shortly after birth. True incidence of HD in adulthood is unknown, because the illness is often undiagnosed or misdiagnosed in the adult population. A variety of nonspecific gastrointestinal complains (constipation, abdominal discomfort, and abdominal pain), which can be characteristic for HD, also commonly occur in eating disorders (ED). This chapter will discuss the symptomatic overlap between the two conditions across the lifespan and will present some clinical considerations promoting their thorough diagnosis and treatment.
Real-world comorbidities of atopic dermatitis in the U.S. adult ambulatory population.

Abstract Background Atopic dermatitis (AD) is a pruritic inflammatory skin disease associated with various comorbidities. However, comprehensive analyses of real-world comorbidities in adult AD patients are limited. Objective To characterize the real-world comorbidities associated with adult AD in an ambulatory population. Methods We queried the MarketScan Commercial Claims and Encounters database from January 1, 2017 to December 31, 2017. Multivariable logistic regressions were performed to compare comorbidities in adult AD patients vs. age- and sex-matched controls. Results A total of 39,779 AD patients and 353,743 controls were identified. Increased odds of psychiatric conditions including anxiety (OR 1.44) and mood disorders (OR 1.31) were observed in AD. AD patients had higher likelihood of autoimmune diseases including vitiligo (OR 4.44) and alopecia areata (OR 6.01). Adult AD was also associated with infections including impetigo (OR 9.72), MRSA (OR 3.92), and cellulitis (OR 2.52). AD patients were more likely to have systemic conditions including lymphoid/hematopoietic malignancy (OR 1.91), atherosclerosis (OR 1.69), and metabolic syndrome (OR 1.47). For all the above, p Limitations Retrospective analysis of healthcare claims data Conclusions Adult AD is associated with various psychiatric and systemic comorbidities, emphasizing the systemic nature of AD and the need for collaborative management of these patients.
Canyon-filling debrite indicates that canyon erosion and large-scale mass movement off Georges Bank, USA, are unrelated processes

Large-scale mass movement has occurred along the lower continental slope off Georges Bank, USA. Some of the mass movement debris has intercepted and partly filled Veatch Canyon; proximal debris chokes the canyon on the lower slope and a distal debris tongue crosses the canyon on the upper rise. These relations show that the canyon was formed prior to the mass movement and that debris flow plugged the channel rather than enlarged it or further eroded it. Canyon erosion and debris flow are therefore not necessarily genetically related.
Going for the jugular in public diplomacy: How adversarial publics using social media are challenging state legitimacy

Abstract Traditionally, nations have viewed other nations as their primary competitors in public diplomacy (PD). In a quest to increase their effectiveness, states are applying relationship management and pursuing a more relational PD approach with publics. However, present understanding of relationships may be one-sided, focusing primarily on the state's relationship-building activities and overlooking the public's agency in defining relations. This paper uses relationalism as an analytical lens to construct a 4-quadrant model of public diplomacy based on the relational dynamics between a state and publics. The model reveals a parallel evolution of communication technology and public diplomacy initiatives that move from assumptions of no relations with publics, to favorable relations, to adversarial relations. A case study from Turkey is used to illustrate how diverse groups can use social media to form unlikely alliances to become a fluid, adversarial public capable of ‘going for the jugular’ and challenging state legitimacy. Aggressive separation tactics by the state to counter adversarial publics can inadvertently create a ‘relational paradox’ that leaves the two parties more politically divided and yet more relationally intertwined. The study implications stress the need for states to monitor their relational dynamic with publics as a precursor for developing reflective strategies.
Autostimulation of growth by human myelogenous leukemia cells (HL-60)

We have studied the effects of medium conditioned by the human progranulocytic leukemia cell line, HL-60, on the subsequent growth of new inocula of HL-60 cells. When HL-60 cells were cultured at high cell density, optimal growth rate occurred in liquid suspension and confluent colony growth was observed in viscous medium without the addition of conditioned medium. However, when cells were cultured at lower cell density, growth rate was reduced and colony growth was nil unless conditioned medium from HL-60 culture was added. All HL-60 populations studied, including the earliest available passage, 9, both elaborated and responded to HL-60 CM. HL-60 CM did not stimulate normal human or mouse granulocyte-monocyte colony-forming cell (CFU-GM) growth. Conditioned media from other human cell lines varied in the ability to stimulate HL-60 cell and CFU-GM proliferation. Some, such as GCT CM, stimulated both HL-60 cells and normal CFU-GM, whereas others, like HL-60 CM, stimulated only HL-60 growth. The majority of cell line CMs tested did not stimulate either HL-60 or CFU-GM. Chromatography of HL-60 CM on Ultrogel AcA54 showed a single peak of HL-60 stimulating activity of apparent molecular weight 13,000. The ability of HL-60 cells to elaborate this activity provides a possible explanation for their proliferation at higher cell densities. Autostimulation may prove to be important in the high growth potential of other cell populations that undergo unrepressed proliferation.
The Magnitude of Secondary Electron Contributions in Photon Stimulated Desorption

Recent reports on the extent of secondary electron contributions in electron/photon stimulated desorption (ESD/PSD) appear to be contradictory. JAEGER et al. [1] suggested that secondary electrons provide the dominant contribution to the H+ yield from NH3/Ni and called the process x-ray induced ESD (XESD). Others have concluded that the XESD process is the dominant mechanism in the PSD of N+ and O+ ions from mixed condensed gases such as N2 and O2 [2] and in the PSD of H+ ions from OH/YbO-Sm [3]. On the other hand, considerable evidence exists in the literature for the dominance of the direct photon excitation mechanisms. This evidence usually comes from observed differences between the ion yield and the secondary electron yield or from the absence of any clear structure or “turn on” at certain core levels [4].
“Dangerous” Youth: Tourism Space, Gender Performance, and the Policing of Havana Street Hustlers

Resumen El desarrollo del sector turismo salvo a la economia cubana del colapso economico en la decada de las 1990s, pero tambien produjo nuevos problemas de control social. Frente a estos ultimos, la re-especializacion de la vida social fue obligatoria y las instituciones existentes resultaron insuficientes. La migracion hacia La Habana sobrecargo la infraestructura urbana; los turistas extranjeros introdujeron ideas, valores y comportamientos que eran incompatibles con las normas revolucionarias; y la imagen turistica se vio amenazada por estafadores, ladrones de poca monta y trabajadores sexuales. La solucion fue la creacion de una nueva fuerza policial que opera en y alrededor de las zonas turisticas y se especializa en el control de las interacciones entre cubanos jovenes y los turistas. Los oficiales de la “Policia Especializada” acosan constantemente a los jovenes de la calle; sin embargo, los datos etnograficos indican que los jovenes y los oficiales comparten una logica de genero que a veces los vuelve semejantes. Ambos ocupan un lugar complejo e incierto en relacion con las cambiantes fronteras socio-culturales de la nacion y el estado. El analisis convoca a la geografia critica y la teoria de genero como performance para comprender palabras y experiencias de los pingueros.
Wave propagation in prestrained polyethylene rods: Continuous-wave and pulse-propagation techniques are used to investigate the effect of moderate quasistatic tensile prestrain upon the dynamic mechanical properties of low-density polyethylene

The influence of prestrain on the propagation of mechanical waves along a slender rod of low-density unoriented polyethylene was experimentally investigated. The investigation consisted of two major parts: first, a uniaxial continuous-wave technique was used to determine the dynamic mechanical properties of the polyethylene in the form of the frequency-dependent phase velocity and damping factor for frequencies spanning the audio spectrum and for levels of uniaxial static prestrain up to 10 percent. A linear incremental dynamic viscoelastic behavior about a state of finite-static prestrain was shown to obtain over the range of strains and frequencies used.
Yeasts producing exopolysaccharides with drag-reducing activity

Abstract A search was conducted for yeast strains that could be cultured on methanol, ethanol, or glucose and that produce exopolysaccharides which reduce friction in turbulent liquid flows. Five yeast strains and one yeast-like fungus produced drag-reducing exopolysaccharides when grown on glucose and/or ethanol: Candida boidinii, Cryptococcus laurentii, Hansenula capsulata, Lipomyces starkeyii, Rhinocladellia elatior , and Rhodotorula glutinis . Polysaccharides with specific drag-reducing activities comparable to commercial xanthan gum were isolated from C. laurentii, R. glutinis , and R. elatior , but only when grown on glucose or ethanol. The exopolysaccharide from C. boidinii reduced drag when grown on methanol. A preliminary characterization of this previously unreported exopolysaccharide revealed that it is composed of glucose and mannose in an approximately 1:1 ratio. It is a relatively homogeneous polymer with a molecular weight of about 850 Kd and its production is favored by inclusion of ≥0.11% tryptone in the growth medium.
Needs and scientific opportunities for research on substance abuse treatment among Hispanic adults.

The results of a focused search of the literature on empirical studies of substance abuse treatment outcomes with Hispanic adults are reviewed. Also provided are key research opportunities and recommendations on substance abuse treatment for Hispanics. The paper is divided into two major sections: the first focuses on behavioral drug treatment studies on Hispanic adults, and the second identifies published original articles in pharmacotherapy for substance abuse disorders in Hispanic populations. The authors found a common theme that appears to cut across research on behavioral treatment and pharmacotherapy, namely that more empirical research is needed to determine which treatments are efficacious with Hispanic populations. For treatment modalities not associated with promising effect sizes with Hispanic samples, cultural modifications may be needed to improve the compatibility of the treatment with Hispanic culture. For those treatments found to have promising effect sizes with Hispanic populations, follow-up analyses and/or studies should be conducted to ascertain whether the treatment is differentially efficacious with various Hispanic subgroups, with Hispanics at different levels of acculturation, and with Hispanics from various socioeconomic backgrounds. The authors stress the need for theory-driven interventions to be developed specifically for well-characterized Hispanic subgroups (e.g., suburban, middle-income Puerto Ricans living in the Northeast).
STUDIES ON THE RELATIVE SENSITIVITY FOR ANDROGEN FEEDBACK INHIBITION IN RATS DURING SEXUAL MATURATION

This set of experiments was designed to see : (1) the relative sensitivity of a number of androgens on the feedback inhibition of gonadotropins, (2) if there is any alteration in the magnitude of feedback inhibition with sexual maturation. Testosterone, dihydrotestosterone, 3α-androstanediol and androstenedione were given in one injection s.c. as 250 μg/100 g body weight at the ages 16, 23, 26, 35, 56, 65 and 90 days. 24 hrs later LH and FSH were measured. The results suggest, that(1) The 2 adrenal androgens DHA and Δ 4 have no suppressive action on the gonadotropins, (2) All potent androgens as T,DHT,3α-Adiol suppressed LH secretion the order being 3α-Adiol, DHT, T at the period of 26–35 days where maximum suppression was observed, (3) T and DHT both inhibited FSH in all ages in male rats, whereas 3α-Adiol was ineffective, (4) The inhibition of the gonadotropins was found to be age dependent with the same dose administered, (5) The same dose of androgens suppressed LH maximally at days 26 and 35. In younger animals the suppression was not as marked but significantly lower than seen in the older age groups, (6) For FSH the situation is not as clear as that for LH, but still comparable. T and DHT had bigger inhibition in premature animals than in adults.
Two-step synthesis of multivalent cancer-targeting constructs.

Selective targeting of constructs to pathological cells by conjugating one or more ligands for an overexpressed receptor has been proposed to enhance the delivery of therapeutics to and imaging of specific cells of interest. Previous work in our lab has demonstrated the efficacy of targeting glioblastoma cells with a multivalent, biomacromolecular construct targeted to the α6β1-integrin. However, solid-phase synthesis of this construct was inefficient in terms of cost and number of steps. Here we show proof-of-concept of a two-step synthesis that can be used to create similar constructs targeted to glioblastoma cells. Specifically, a well-defined aldehyde side chain polymer was synthesized and oxime chemistry was employed to conjugate ligands specific for the α6β1-integrin. These constructs were then tested in competitive binding, fluorescence binding, and toxicity assays, through which we demonstrate that constructs are multivalent, preferentially target glioblastoma cells, and are nontoxic. Rapid, poten...
Inhibition of endothelial cell activation by the homeobox gene Gax

Abstract Background. Angiogenesis is critical to tumor growth. Gax, a homeobox transcription factor whose expression in the adult is restricted mainly to the cardiovascular system, strongly inhibits growth factor-stimulated phenotypic modulation of vascular smooth muscle cells in vitro and in vivo. The function of Gax in vascular endothelium is unknown, but we hypothesized that it may play a similar role there. We therefore studied Gax expression in vascular endothelial cells and its effects on proliferation and tube formation. Materials and methods. Gax expression in normal endothelial cells was examined in vitro by Northern blot and reverse transcriptase polymerase chain reaction and in vivo by immunohistochemistry. A replication-deficient adenovirus was then used to express Gax in human umbilical vein endothelial cells (HUVECs). HUVEC proliferation, 3H-thymidine uptake, p21 expression, and tube formation on reconstituted basement membrane were measured at different viral multiplicities of infection. Results. Gax mRNA was detected in HUVECs by reverse transcriptase polymerase chain reaction and Northern blot analysis and in normal vascular endothelium by immunohistochemistry. Compared with controls transduced with a virus expressing β-galactosidase, Gax strongly inhibited HUVEC proliferation and mitogen-stimulated 3H-thymidine uptake. p21 expression in HUVECs transduced with Gax was increased up to 5-fold as measured by Northern blot, and p21 promoter activity was activated by 4- to 5-fold. Tube formation on Matrigel was strongly inhibited by Gax expression. Conclusions. Gax is expressed in vascular endothelium and strongly inhibits endothelial cell activation in response to growth factors and tube formation in vitro. These observations suggest that Gax inhibits endothelial cell transition to the angiogenic phenotype in response to proangiogenic growth factors and, as a negative regulator of angiogenesis, may represent a target for the antiangiogenic therapy of cancer.
Resorufin as a probe for the dynamics of solvation by hydrogen bonding

Abstract Resorufin is shown to be good probe solute for the direct measurement of the rates of formation and breaking of solvent—solute hydrogen bonds. In ethanol, a hydrogen-bond equilibration time of 40 ps is found for both the ground and excited states. Deuteration of the solvent has no effect on the equilibration time. The same is also found in more viscous ehtylene glycol solutions, indicating that hydrogen-bond breaking requires only local motion of the bonding moiety.
Vadose zone microbial biobarriers remove nitrate from percolating groundwater.

Microbial biobarriers are an established technique for cleansing contaminants from aquifers. This study evaluated their use under well-drained conditions within the vadose or unsaturated zone. Three sets of sand filled columns, the positive control, field-capacity, and sub-field-capacity groups, contained biobarriers formed by mixing sand with sawdust and soybean oil. The biobarriers were positioned 1 m from the top of the 145 cm columns. A fourth set of column, the negative control, contained no biobarrier. The positive control group’s biobarriers were saturated while biobarriers in the other groups were allowed to drain. At intervals water containing 20 mg l−1 NO 3 − –N was applied to the columns, the water was allowed to percolate through the columns, and the effluents were collected and analyzed. The biobarriers were highly effective at removing NO 3 − . NO 3 − –N in the effluents from the field-capacity, sub-field-capacity, and positive control groups averaged 0.4 ± 0.1, 0.6 ± 0.1, and 0.8 ± 0.1 mg l−1, respectively, during the final weeks of the study while effluents from the negative control group averaged 17.9 ± 0.4 mg l−1. The barriers removed NO 3 − even when the water content was in the 20–40% pore filled space range. During the 12-week study the field-capacity barriers lost 5.6% of their organic content while those in the sub-field-capacity group lost no detectable organic matter indicating that the barriers contained sufficient substrate to last for several years. Vadose zone biobarriers could provide a useful means of protecting surface waters and aquifers from NO 3 − .
Learning with digital texts

Readers now encounter many texts used for learning in digital formats.Tested relationships among navigation, comprehension, prior knowledge and learning.No significant relationship between comprehension ability and navigation behaviors.No significant relationships between prior knowledge and navigation or learning.Goal-related concept visits were positively related to coherent page transitions. Currently of great significance to the study of reading and text comprehension is the fact that learners now encounter many texts in digital formats. While making navigation decisions during reading digital texts, readers need to comprehend both the individual texts and the relationships among sources in the overall structure of the digital text environment. Prior knowledge and reading comprehension ability may impact the ways in which students are able to utilize the structure of the digital text system in order to navigate through the text content. This study further investigated the relationships among reading comprehension ability, prior content knowledge, navigation behaviors in a system of digital texts, and learning outcomes. We found no significant relationship between comprehension ability and navigation behaviors. Further, there were no significant relationships between prior knowledge and navigation or learning. Goal-relevant concept visits were positively related to coherent page transitions, and the proportion of time spent reading about goal-relevant concepts was significantly positively related to learning outcomes. We discuss these results in relation to some key areas for instruction, such as helping students to reflect on prior knowledge and plan their navigation strategies, and further research in terms of utilizing digital text structures to improve comprehension.
Dopamine Levels in Hypophysial Stalk Blood in the Rat are Sufficient to Inhibit Prolactin Secretion In Vivo

Much evidence indicates that dopamine can inhibit PRL secretion. However, it is still unclear whether dopamine acts on hypothalamic neurons to stimulate PRL-inhibiting factor (PIF) release or whether dopamine is itself PIF, acting directly on the pituitary. This study was designed to determine if PRL secretion is inhibited by dopamine infusions producing plasma dopamine levels which mimic those found in hypophysial stalk plasma. Stalk plasma dopamine concentration in urethane-anesthetized diestrus-1 rats was 6.0 ± 1.1 ng/ml (mean ± SE; n = 10). During a dopamine infusion, stalk plasma dopamine levels were 70% of arterial levels. Therefore, dopamine was infused at a rate which achieved arterial levels of 9–10 ng/ml and the effect on PRL secretion in urethane-anesthetized female rats was measured. In diestrus rats, dopamine did not inhibit PRL secretion. In rats pretreated with α-methyl-p-tyrosine to elevate serum PRL levels, dopamine suppressed PRL secretion 70%. In rats with PRL levels elevated by median ...
Small Angle X-Ray Scattering (Saxs) Study of Coarsening Kinetics in an Aluminum-Lithium Alloy*

Coarsening kinetics was studied in a Al/sub 90.6/Li/sub 9.14/ alloy aged at 100/sup 0/C, 128/sup 0/C, 165/sup 0/C, 178/sup 0/C, and 209/sup 0/C. The time-dependent behavior of the average precipitate radius followed t/sup 1/3/ behavior. The precipitate/matrix interfacial energy obtained from analysis of the kinetic constant was 0.015 J/M/sup 2/ and was largely independent of temperature. The scattering curves exhibit interparticle interference which prevents calculating a particle size distribution. 12 references, 3 figures, 3 tables.
Estimation of the dissolution rates of andesitic glass, plagioclase and pyroxene in a flank aquifer of Poás Volcano, Costa Rica

The dissolution rates of andesitic glass, plagioclase and pyroxene have been calculated for andesitic lava and volcanoclastic material present in a flank aquifer receiving inputs of highly acidic brine from the summit hydrothermal system of Poas Volcano, Costa Rica. Bulk release rates for Na, Ca, Mg and Al along the flow path were calculated by use of solute compositions of acid-chloride-sulfate spring waters located in the Rio Agrio watershed on the NW flank of the volcano, tritium-based residence times and geometric estimates of the reactive surface areas of aquifer rocks. Petrographic data on the composition of interstitial glass and major-mineral phases were used in the mass-balance model NETPATH to calculate individual contributions of glass, plagioclase and pyroxene to the observed mass transfers of Na, K, Ca, Mg, Fe, Al and Si. By assuming that no secondary Al phases were precipitated along the flow path, and assuming a plagioclase composition close to An38, we calculate that solution chemistry of the acid-chloride-sulfate waters of the Rio Agrio watershed is due to dissolution of approximately equal amounts of glass and plagioclase, with most of the Mg and Fe coming from pyroxene dissolution. Calculated rates are typically within one order of magnitude of experimentally-derived rates measured at similar pH and temperatures. In addition, the relative order of mineral reactivity was similar between field- and laboratory-based estimates: pyroxene > plag ⩾ andesitic glass. The good agreement between the field- and laboratory-based estimates is attributed to the interaction of relatively fresh andesite and volcano-clastic material with low-pH fluids of the NW flank aquifer. The largest uncertainty in our calculation is estimation of reactive mineral surface area.
Canavan's spongiform leukodystrophy: a clinical anatomy of a genetic metabolic CNS disease

Canavan disease (CD) is a globally distributed early-onset leukodystrophy. It is genetic in nature, and results from an autosomally inherited recessive trait that is characterized by loss of the axon’s myelin sheath while leaving the axons intact, and spongiform degeneration especially in white matter. There is also a buildup of N-acetyl-l-aspartate (NAA) in brain, as well as NAA acidemia and NAA aciduria. The cause of the altered NAA metabolism has been traced to several mutations in the gene for the production of aspartoacylase, located on chromosome 17, which is the primary enzyme involved in the catabolic metabolism of NAA. In this review, an attempt is made to correlate the change in NAA metabolism that results from the genetic defects in CD with the processes involved in the development of the CD syndrome. In addition, present efforts to counter the results of the genetic defects in this disease are also considered.
Portal vein thrombosis after laparoscopic cholecystectomy.

ABSTRACT Introduction: Portal vein thrombosis (PVT) is a relativelyuncommon complication after abdominal surgery. Case Report: We report an even more unusual case ofPVT 10 days after an uncomplicated laparoscopic chole-cystectomy, believed to be only the fourth reported casein the literature of this rare complication. Conclusion: Albeit extremely rare, PVT should be in-cluded in the differential diagnosis for abdominal symp-toms and/or elevated hepatic function tests after laparo-scopic cholecystectomy. Key Words: Portal vein, Thrombosis, Cholecystectomy,Laparoscopic surgery. INTRODUCTION Portal vein thrombosis (PVT) is an extremely rare compli-cation after abdominal surgery. We report what is be-lieved to be the fourth reported case and youngest re-ported patient with left PVT after laparoscopiccholecystectomy (LC). PVT after laparoscopic surgery isextremely rare but should be included in the differentialdiagnosis of unexplained abdominal pain after laparo-scopic cholecystectomy. CASE REPORT
Light Scattering by Hexagonal Ice Crystals

Abstract A complete and traceable geometric ray-tracing solution for finite hexagonal columns and plates arbitrarily oriented in space has been developed by means of analytic geometry. In addition, an analytic expression for the cross-sectional area for arbitrarily oriented hexagons also has been derived based on which Fraunhofer diffraction and extinction and scattering cross sections in the limit of geometric optics can be computed exactly. The program involving geometrical reflection and refraction and Fraunhofer diffraction was used to compute the scattered intensities corresponding to two components of polarization for randomly oriented columns and plates in a horizontal plane and three-dimensional space. The scattered intensities were subsequently normalized to yield the nondimensional phase function commonly used in radiative transfer analyses. Numerical computations have been performed to study the effects of size, shape, orientation, and absorption on the scattering phase function and linear pola...
Differential protective effects of varying degrees of hypoxia on the cytotoxicities of etoposide and bleomycin

Oxygen is thought to be involved both directly and indirectly in the mechanisms of action of several anticancer agents. We studied the effects of various oxygen concentrations on the cytotoxicities of the following drugs: bleomycin (BLM), etoposide (VP-16), doxorubicin (DOX), and mitomycin C (MMC). Human sarcoma cells, MESSA, were exposed to drug for 1 h at one of several oxygen concentrations: less than 1%, 2.5%, 5%, 21%, and 95%. Cytotoxicity was assessed by cellular incorporation of 3H-thymidine into DNA 5 days after drug exposure. Control experiments varying oxygen concentration without drugs demonstrated toxicity only at the highest concentration (95%). Three different responses of drug sensitivity to varying oxygen tensions were observed. BLM, which has been shown to utilize oxygen as a substrate in generating free radicals and producing DNA scission, demonstrated a progressive increase in cytotoxicity over the entire range of increasing oxygen concentrations. This is consistent with the model of a BLM-cation-oxygen complex and catalytic reduction of oxygen. VP-16, which also produces DNA strand breakage but by interaction with topoisomerase II, exhibited a threshold response. VP-16 toxicity was ameliorated by anoxic conditions (less than 1% O2), but not by oxygen concentrations of 2.5%–95%. The reason for this protective effect of anoxia with VP-16 is not clear. In contrast, acute anoxia had no effect on the cytotoxicities of DOX and MMC. We conclude that acute hypoxia protects cells from both BLM and VP-16 but that the nature of that protection is different. VP-16 toxicitiy is blunted only by severe anoxia, wheaeas BLM exhibits a dose response effect over the entire range of oxygen concentrations.
Gene Transfer Into Normal and Atherosclerotic Human Blood Vessels

Abstract—Gene transfer to blood vessels is a promising new approach to the treatment of the vascular diseases, but the feasibility of gene transfer to adult human vessels has not been explored. We introduced an adenovirus vector encoding a marker gene human placental alkaline phosphatase into normal and atherosclerotic human vessels in organ culture. In the normal vessels, recombinant gene was expressed preferentially in the endothelial cells (≈100%), intimal smooth muscle cells (1.3±0.4%, 1.4±1.0%, and 3.8±0.8% in the internal mammary arteries, saphenous veins, and normal coronary arteries, respectively), and various adventitial cells. Advanced, complicated atherosclerotic plaques demonstrated a similar efficiency of recombinant gene expression (3.1±0.5% and 3.8±0.3% of nonendothelial intimal cells in the coronary artery and carotid artery plaques, respectively). Of these intimal cells, macrophages and smooth muscle cells expressed a transgene, identifying them as targets for gene transfer. Areas of plaq...
Substitution of the conserved Arg-Tyr dyad selectively disrupts the hydrolysis phase of the IMP dehydrogenase reaction.

Inosine 5‘-monophosphate dehydrogenase (IMPDH) catalyzes the oxidation of IMP to XMP via the covalent E−XMP* intermediate (E−XMP*), with the concomitant reduction of NAD+. Hydrolysis of E−XMP* is rate-limiting, and the catalytic base required for this step has not been identified. An X-ray crystal structure of Tritrichomonas foetus IMPDH with mizoribine monophosphate (MZP) reveals a novel closed conformation in which a mobile flap occupies the NAD+/NADH site [Gan, L., Seyedsayamdost, M. R., Shuto, S., Matsuda, A., Petsko, G. A., and Hedstrom, L. (2003) Biochemistry 42, 857−863]. In this complex, a water molecule is coordinated between flap residues Arg418 and Tyr419 and MZP in a geometry that resembles the transition state for hydrolysis of E−XMP*, which suggests that the Arg418-Tyr419 dyad activates water. We constructed and characterized two point mutants, Arg418Ala and Tyr419Phe, to probe the role of the Arg418-Tyr419 dyad in the IMPDH reaction. Arg418Ala and Tyr419Phe decrease kcat by factors of 500 a...
Slow Neutron Velocity Spectrometer Studies of O 2 , N 2 , A, H 2 , H 2 O, and Seven Hydrocarbons

The slow neutron cross sections of free atoms of O, N, and A have been determined to be; O:3.73, N:9.96, A:0.68 barn. Between 1 and 15 ev the ${\mathrm{N}}_{2}$ curve shows an ${E}^{\ensuremath{-}\frac{1}{2}}$ slope of 0.34 barn\ifmmode\times\else\texttimes\fi{}${(\mathrm{ev})}^{\mathrm{\textonehalf{}}}$ per atom. Measurements on these elements have been extended to over 10,000 ev with no resonances observed. Dependence of cross section upon neutron energy from 1 ev to 0.003 ev is presented for ${\mathrm{O}}_{2}$, ${\mathrm{N}}_{2}$, ${\mathrm{H}}_{2}$, ${\mathrm{H}}_{2}$O, methane, ethane, propane, $n$-butane, cetane, ethylene, 1,3-butadiene, and liquid$n$-butane. At the lowest energies, the large observed ${\mathrm{H}}_{2}$ cross section is attributed largely to thermal translational motion of the molecule. The measurements on the hydrocarbons show the effect of the binding of H in various molecules. Comparison with the theories of Bethe and Arley is made. No difference has been detected in cross-section measurements on gaseous and liquid $n$-butane.
Single- and Double-Resonance Experiments of Quadrupolar Nuclei in Solids Using Sensitivity Enhancement of the Central Transition

Abstract Population enhancement for NMR of the central transition of quadrupolar nuclei in solids is performed by using adiabatic radiofrequency sweeps of the satellite transitions. Single-resonance experiments are reported for 17 O, 23 Na, 27 Al, and 93 Nb nuclei in powders of Al 2 O 3 , NaNbO 3 , and LiNbO 3 , and in Pyrex glass. Experimental techniques using single-coil probe circuits capable of both wideband frequency sweeps and narrowband detection are presented. The combination of population enhancement with cross polarization from 27 Al to 17 O in α-Al 2 O 3 (corundum) powder is demonstrated. The sensitivity-enhancement technique is robust, with no critical parameters.
Physical properties of type I collagen in solution: structure of alpha-chains and beta- and gamma-components and two-component mixtures.

The structure of thermally denatured Type I collagen has been studied using laser light scattering. The results indicate that the diffusion coefficients of α-chains and β- and γ-components are 1.550 ± 0.08 × 10−7, 1.000 ± 0.05 × 10−7, and 0.835 ± 0.04 × 10−7 cm2/sec, respectively, at temperatures between 20 and 40°C. It is concluded from diffusion data that these species have hydrodynamic radii of about 13.8 nm (α-chain), 21.5 nm (β-component), and 25.7 nm (γ-component), consistent with previous studies of thermal denaturation by light scattering. It is also concluded, based on volume calculations, that a large volume increase occurs when the triple helix unfolds. Homodyne correlation functions for two component mixtures of α-chains and β-and γ-components appeared to decay exponentially. In all but one case discussed the correlation function could be fitted with a single component having a translational diffusion coefficient which was an intensity weighted average of the diffusion coefficient of each component present.
Serum CK-BB isoenzyme in preterm infants with periventricular hemorrhage

Periventricular hemorrhage in the preterm infant kills or injures thousands annually. Because of the relatively recent emergence of PVH as a major problem, the pathophysiology of this disorder is not yet known. This study was performed to examine the relationship between brain origin creatine kinase and the occurrence of PVH, both prior to the time of the hemorrhage and after. Twenty-six preterm infants were studied. Serum CK-BB levels were obtained at birth, if possible, and twice daily thereafter for four to seven days. The PVH was proven by either CT scan or autopsy. Infants with PVH had significantly higher average serum levels of CK-BB when compared to infants without, both immediately after birth and during the follow-up period.
ON CONSENSUS, COLLAPSIBILITY, AND CLADE CONCORDANCE

Consensus in cladistics is reviewed. Consensus trees, which summarize the agreement in grouping among a set of cladograms, are distinguished from compromise trees, which may contain groups that do not appear in all the cladograms being compared. Only a strict or Nelson tree is an actual consensus. This distinction has implications for the concept of support for cladograms: only those branches supported under all possible optimizations are unambiguously supported. We refer to such cladograms as strictly supported, in contrast to the semistrictly (ambiguously) supported cladograms output by various current microcomputer programs for cladistic analysis. Such semistrictly supported cladograms may be collapsed, however, by a variety of options in various programs. Consideration of collapsibility and optimization on multifurcations leads to some conclusions on the use of consensus. Consensus tree length provides information about character conflict that occurs between, not within, cladograms. We propose the clade concordance index, which employs the consensus tree length to measure inter-cladogram character conflict for all characters among a set of cladograms. “On the surface, the story was not complex.” Hunter S. Thompson,Songs of the Doomed, p.194
A Co-Mentoring Project: An Intergenerational Service-Learning Experience.

Intergenerational service-learning between college students and older adults is a commonly used in educational gerontology. Service-learning is believed to enhance student learning through an equivalent focus on service and learning, reflection, and linking course content with the service experience. This article describes a comentoring project (CMP), an intergenerational service-learning program that links older adult volunteers and students enrolled in an undergraduate lifespan developmental psychology course. The researcher conducted a comprehensive evaluation of the project's impact on students, including a pre- and post-assessment using the Facts on Aging Quiz ([FAQ1]; Palmore, 1998), structured project evaluation feedback, and qualitative data analysis. Results indicated students were more knowledgeable about older adults after the service-learning experience. Consistent with previous service-learning literature, students often reported intrapersonal development and establishment of a deep relations...
A new method for assessment of cultured cardiac myocyte contractility detects immune factor-mediated inhibition of beta-adrenergic responses.

BACKGROUND Potentially reversible congestive heart failure accompanies disease states associated with an immune cell myocardial infiltrate such as cardiac allograft rejection and inflammatory myocarditis. We therefore examined the hypothesis that immune cells can produce noncytotoxic alterations in cardiac function. METHODS AND RESULTS A novel system to evaluate cultured cardiac myocyte contractility was developed using neonatal rat cardiocytes grown on human amniotic membrane segments. Spontaneous synchronous cell beating produced macroscopic distortion of these membranes. Movement of free-floating membranes anchored within a perfusion chamber was visualized under low-power microscopy and measured from recordings of the rhythmic displacement of membrane-adherent markers. Additions of graded concentrations of isoproterenol to the perfusate produced up to threefold increases in the initial contractile phase velocity (contractile index), with an EC50 of 10(-7) M. When the extracellular Ca2+ concentration was increased from 0.9 to 3.6 mM, 2.43-fold increases in this index occurred. Myocytes incubated for 72 hours in the presence of dilutions of medium conditioned by activated rat splenic macrophages and lymphocytes exhibited an isoproterenol contractile index inhibited by 62% compared with control cells. In contrast, responses of supernatant-exposed and control cells to increased extracellular Ca2+ concentrations were not significantly different. Parallel studies of increases in myocyte intracellular adenosine 3':5'-cyclic monophosphate concentrations in response to isoproterenol stimulation demonstrated correlative inhibition that was specific for exposure to medium conditioned by immune cells. CONCLUSION Thus, a new method of in vitro cardiac contractility assessment that has significant advantages over existing systems has been developed and characterized. This new method has enabled description of an inhibitor of cardiac contractile function produced by activated immune cells.
Water Metabolism with Prolonged Ethanol Consumption in the Rat

18 rats were maintained on an alternate day presentation schedule in which one of three alcohol concentrations was substituted for water. An apparently adequate fluid balance was attained for 6 and 12, but not for 24% alcohol.