cssi/SciSciGPT-SciSciNet huggingface dataset:
Factors Affecting the Implementation of Argument in the Elementary Science Classroom. A Longitudinal Case Study

This longitudinal case study describes the factors that affect an experienced teacher’s attempt to shift her pedagogical practices in order to implement embedded elements of argument into her science classroom. Research data was accumulated over 2 years through video recordings of science classes. The Reformed Teacher Observation Protocol (RTOP) is an instrument designed to quantify changes in classroom environments as related to reform as defined by the National Research Council (National science education standards. Washington, DC: National Academy Press, 1996b) and the National Research Council (Fulfilling the promise: Biology education in the nation’s schools, Washington, DC: National Academy Press, 1990) and was used to analyze videotaped science lessons. Analysis of the data shows that there was a significant shift in the areas of teacher questioning, and student voice. Several levels of subsequent analysis were completed related to teacher questioning and student voice. The data suggests a relationship between these areas and the implementation of scientific argument. Results indicate that the teacher moved from a traditional, teacher-centered, didactic teaching style to instructional practices that allowed the focus and direction of the lesson to be affected by student voice. This was accomplished by a change in teacher questioning that included a shift from factual recall to more divergent questioning patterns allowing for increased student voice. As student voice increased, students began to investigate ideas, make statements or claims and to support these claims with strong evidence. Finally, students were observed refuting claims in the form of rebuttals. This study informs professional development related to experienced teachers in that it highlights pedagogical issues involved in implementing embedded elements of argument in the elementary classroom.
Noninvasive cardiac output monitoring with bioreactance as an alternative to invasive instrumentation for preclinical drug evaluation in beagles.

Abstract Introduction Non-invasive measurement of cardiac output (CO) using bioreactance signals (NICOM) was recently validated in swine and human adults. The present study was designed to test the hypothesis that NICOM flow measurements can accurately measure CO and detect acute drug-induced changes in aortic blood flow (AoQ) ≥ 10% in beagles. Methods Data from 5 anesthetized, open chest beagles used for preclinical screening of novel neuromuscular blocking drugs were analyzed for the study. AoQ was measured beat-to-beat with a probe on the aortic root and averaged over 30 s intervals. NICOM CO measurements were simultaneously obtained every 30 s. NICOM precision (random variation) and accuracy relative to AoQ were assessed from individual segments of steady-state data. The ability of NICOM to detect acute alterations in AoQ ≥ 10% was determined from other segments with dynamic change. Results 516 simultaneous CO measurements between 826 and 2436 mL/min were analyzed. Steady-state measurements (20% of the dataset) revealed an average AoQ − NICOM difference (bias) of 63 ± 38 mL/min, a percent error of 6.1%, and a NICOM precision of 6.1%. Within the acute change dataset, 21/23 events reflecting a ≥ 10% change in beat-to-beat AoQ were detected by the NICOM (sensitivity of 0.91). In none of 10 instances where drug or fluid injection altered AoQ Discussion Continuous, non-invasive measurement of CO by bioreactance provides data that satisfactorily approximates invasive measurement of aortic blood flow in beagles. In addition, despite a 30 s interval between measurements, the NICOM appears to have sufficient fidelity to detect and quantify acute, drug-induced changes in CO. These data suggest that the NICOM may represent an alternative to open chest instrumentation for CO measurement in preclinical drug evaluation studies.
New amino-acids in bacterial hydrolysates.

As part of the programme in this Laboratory of studying the relation between a bacteriophage and its host organism, analyses have been made of the amino-acid contents of hydrochloric acid and barium hydroxide digests of E. coli. The methods used for this have been the partition chromatography of Consdon, Gordon and Martin1 as modified2 to yield quantitative results. The following known amino-acids have been identified in these hydrolysates : aspartic and glut-amic acids, serine, glycine, alanine, threonine, valine, isoleucine, leucine, methionine, tryptophane, phenylalanine, tyrosine, proline, arginine, lysine and histidine. In addition, three weak spots, indicated by the letters a, b, c in Fig. 1, have been noticed which do not correspond to known naturally occurring amino-acids. Spots b and c have only been visible when concentrated hydrolysates containing c. 40 mgm. N/c.c. have been applied to the paper.
Control of middle ear inflammatory and ion homeostasis genes by transtympanic glucocorticoid and mineralocorticoid treatments.

Hypothesis Transtympanic steroid treatment will induce changes in ion homeostasis and inflammatory gene expression to decrease middle ear inflammation due to bacterial inoculation. Background Otitis media is common, but treatment options are limited to systemic antibiotic therapy or surgical intervention. Systemic glucocorticoid treatment of mice decreases inflammation and improves fluid clearance. However, transtympanic delivery of glucocorticoids or mineralocorticoid has not been explored to determine if direct steroid application is beneficial. Methods Balb/c mice received transtympanic inoculation of heat-killed Haemophilus influenzae (H flu), followed by transtympanic treatment with either prednisolone or aldosterone. Mice given PBS instead of steroid and untreated mice were used as controls. Four hours after steroid treatment, middle ears were harvested for mRNA extraction and 24 hours after inoculation middle ears were harvested and examined for measures of inflammation. Results H flu inoculation caused the increased expression of nearly all inflammatory cytokine genes and induced changes in expression of several genes related to cellular junctions and transport channels. Both steroids generally reversed the expression of inflammatory genes and caused ion and water regulatory genes to return to normal or near normal levels. Histologic evaluation of middle ears showed improved fluid and inflammatory cell clearance. Conclusion Improvement in middle ear inflammation was noted with both the glucocorticoid prednisolone and the mineralocorticoid aldosterone. This was due to reversal of inflammation-induced changes in middle ear cytokine genes, as well as those involved in ion and water homeostasis. Because glucocorticoids bind to the mineralocorticoid receptor, but not the reverse, it is concluded that much of the reduction of fluid and other inflammation measures was due to these steroids impact on ion and water transport channels. Further research is necessary to determine if this alternative mineralocorticoid treatment for otitis media will be clinically effective with fewer side effects than glucocorticoids.
The origins of sex differences in human behavior: Evolved dispositions versus social roles

The origins of sex differences in human behavior can lie mainly in evolved dispositions that differ by sex or mainly in the differing placement of women and men in the social structure. The present article contrasts these 2 origin theories of sex differences and illustrates the explanatory power of each to account for the overall differences between the mate selection preferences of men and women. Although this research area often has been interpreted as providing evidence for evolved dispositions, a reanalysis of D. M. Buss's (1989a) study of sex differences in the attributes valued in potential mates in 37 cultures yielded cross-cultural variation that supports the social structural account of sex differences in mate preferences.
Complete bony syngnathia: Report of a case and review.

Congenital fusion of the mandible and maxilla is a rare phenomenon. Cases can be broadly classified as bony fusion or soft tissue synechiae. The more rare bony fusion can be further classified as partial or complete and then as syndromic and nonsyndromic. Although theories as to its etiology exist, the cause of the abnormal joining of the mandible and maxilla remains unknown. Because of the paucity of cases, treatment has been individualized.
Inhibition of E2F1/CDK1 pathway attenuates neuronal apoptosis in vitro and confers neuroprotection after spinal cord injury in vivo.

Apoptosis of post-mitotic neurons plays a significant role in secondary tissue damage following traumatic spinal cord injury (SCI). Activation of E2F1-dependent transcription promotes expression of pro-apoptotic factors, including CDK1; this signal transduction pathway is believed to represent an important mechanism for the physiological or pathological neuronal cell death. However, a specific role for this pathway in neuronal apoptosis induced by SCI has not yet been reported. Here we demonstrate up-regulation of the E2F1/CDK1 pathway that is associated with neuronal apoptosis following impact SCI in rats. Expression of E2F1 and CDK1 were robustly up-regulated as early as 15 min after injury and sustained until 3 days post-injury. CDK1 activity and E2F1 downstream targets bim and c-Myb were significantly increased after SCI. Activation of E2F1/CDK1 signaling also was associated with death of neurons in vitro; this was attenuated by shRNA knockdown or pharmacological inhibition of the E2F1/CDK1 pathway. CR8, a novel and potent CDK1 inhibitor, blocked apoptosis of primary cortical neurons at low-micromolar concentrations. Moreover, SCI-induced up-regulation of E2F1/CDK1 and associated neuronal apoptosis was significantly attenuated by systemic injection of CR8 (1 mg/kg, i.p.) at 5 min after injury. CR8 significantly decreased posttraumatic elevation of biochemical markers of apoptosis, such as products of caspase-3 and α–fodrin cleavage, as well as neuronal cell death, as indicated by TUNEL staining. Importantly, CR8 treatment also increased the number of surviving neurons at 5 weeks after injury. Together, these findings indicate that activation of the E2F1/CDK1 pathway contributes to the pathophysiology of SCI and that selective inhibition of this signaling cascade may represent an attractive therapeutic strategy.
RANGE–Robust autonomous navigation in GPS-denied environments

This paper addresses the problem of autonomous navigation of a micro air vehicle (MAV) in GPS-denied environments. We present experimental validation and analysis for our system that enables a quadrotor helicopter, equipped with a laser range finder sensor, to autonomously explore and map unstructured and unknown environments. The key challenge for enabling GPS-denied flight of a MAV is that the system must be able to estimate its position and velocity by sensing unknown environmental structure with sufficient accuracy and low enough latency to stably control the vehicle. Our solution overcomes this challenge in the face of MAV payload limitations imposed on sensing, computational, and communication resources. We first analyze the requirements to achieve fully autonomous quadrotor helicopter flight in GPS-denied areas, highlighting the differences between ground and air robots that make it difficult to use algorithms developed for ground robots. We report on experiments that validate our solutions to key challenges, namely a multilevel sensing and control hierarchy that incorporates a high-speed laser scan-matching algorithm, data fusion filter, high-level simultaneous localization and mapping, and a goal-directed exploration module. These experiments illustrate the quadrotor helicopter's ability to accurately and autonomously navigate in a number of large-scale unknown environments, both indoors and in the urban canyon. The system was further validated in the field by our winning entry in the 2009 International Aerial Robotics Competition, which required the quadrotor to autonomously enter a hazardous unknown environment through a window, explore the indoor structure without GPS, and search for a visual target. © 2011 Wiley Periodicals, Inc. © 2011 Wiley Periodicals, Inc.
A SINGLE-STAGE, LIQUID-PHASE DIMETHYL ETHER SYNTHESIS PROCESS FROM SYNGAS II. COMPARISON OF PER-PASS SYNGAS CONVERSION, REACTOR PRODUCTIVITY AND HYDROGENATION EXTENT

ABSTRACT In part I of this series on the development of a single-stage, liquid-phase dimethyl ether (DME) synthesis process from syngas, the process feasibility and the process variable effects on the dual catalyst activity were discussed. This part focuses on the comparison of the single-stage reactor productivity of liquid phase methanol synthesis to that of the co-production of methanol and DME. It is experimentally demonstrated that the single-stage reactor productivity for the co-production of methanol and DME could be as much as 60% higher than that for liquid phase methanol synthesis alone. Along with this, a 50% increase in the syngas conversion is also obtained. Further, this approach is shown to co-produce methanol and DME in any fixed proportion, ranging from 5% DME to 95% DME, at significant synthesis rates of DME.
One-stage versus two-stage amputation for wet gangrene of the lower extremity: A randomized study *

Although the two-stage amputation technique entails an additional operation, several authors have advocated this approach to deal with wet gangrene because it allows primary wound closure with a reduced chance of wound infection. To examine this issue, 47 patients with necrotizing wet gangrene of the foot were randomized prospectively to receive either a one-stage amputation (definitive below- or above-knee amputation with delayed secondary skin closure in 3 to 5 days) or a two-stage amputation (open ankle guillotine amputation followed by definitive, closed below- or above-knee amputation). Antibiotic coverage was standardized with clindamycin and gentamicin used in all patients. Preoperative blood cultures and intraoperative foot cultures were obtained, as well as cultures from the deep muscle and lymphatic area along the saphenous vein to determine the presence of bacteria at the level of initial amputation. Twenty-four patients (11 diabetic and 13 nondiabetic) were randomized to the one-stage procedure. Twenty-three patients (14 diabetic and nine nondiabetic) were randomized to the two-stage procedure. Five of 24 patients in the one-stage group (21%) had positive muscle cultures vs 10 of 23 patients in the two-stage group (43%). Two of 24 patients in the one-stage group (8%) had positive lymphatic cultures vs 7 of 23 patients in the two-stage group (30%). Five of 24 patients in the one-stage group (21%) had wound complications attributable to the amputation technique vs none of 23 patients in the two-stage group (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
The capacitated maximal covering location problem with backup service

The maximal covering location problem has been shown to be a useful tool in siting emergency services. In this paper we expand the model along two dimensions — workload capacities on facilities and the allocation of multiple levels of backup or prioritized service for all demand points. In emergency service facility location decisions such as ambulance sitting, when all of a facility's resources are needed to meet each call for service and the demand cannot be queued, the need for a backup unit may be required. This need is especially significant in areas of high demand. These areas also will often result in excessive workload for some facilities. Effective siting decisions, therefore, must address both the need for a backup response facility for each demand point and a reasonable limit on each facility's workload. In this paper, we develop a model which captures these concerns as well as present an efficient solution procedure using Lagrangian relaxation. Results of extensive computational experiments are presented to demonstrate the viability of the approach.
Numerical Simulations of Dynamics of a Tunnel Fire

Study of fire in a tunnel is very important for fire safety. Increasing concerns over terrorism put a lot of focus on the fires in tunnels as they are used extensively in mass transit systems all over the world. A lot of experiments have been carried out to study the fire hazard, smoke movement, and the effects of ventilation on fire behavior. In this paper, dynamics of a ventilated tunnel fire have been simulated using Computational Fluid Dynamics (CFD) Software, CFX 5.6, from Ansys Inc. Simulations considers different models of turbulence and radiation heat transfer. Combustion of methane is modeled using the chemical reaction schemes available in the CFX software. Two turbulent models, k–e and Shear Stress Transport, are considered. Radiant heat exchange between the species is modeled using P1 model available in CFX 5.6. The results of the simulation have highlighted the effects of ventilation on the fire and movement of harmful gases such as carbon monoxide and nitrogen oxide. Comparison of simulated temperature fields and flame shape with the experimental data has shown good agreement.Copyright © 2004 by ASME
An Analysis of Helicopter Rotor Modulation Interference

In satellite-to-helicopter communications, interference exists on the incoming signal when the receiving antenna is located below the rotor blades. A bound is established for the performance of a coherent fixed-tone ranging system operating at L band in this interference environment. The scalar diffracted field beneath the rotating blades, at L band and above, is found to satisfy the criterion of Fresnel diffraction, and is computed using the techniques of Fourier optics. The diffracted field is expressed in terms of a narrow-band signal. The amplitude and phase components are calculated from a Fourier Series expansion using the FFT algorithm. The significant harmonics of the phase component of the interference combine with the baseband of the narrow-band, phase-modulated ranging signal. This results in CW interference, and in rearrangement of the first-order, sideband, ranging-tone channel powers. The degradation in ranging accuracy is evaluated by computing the signal-to-interference (SIR) ratio for a set of ranging tones. The post-detection (SIR)PD at the output of the correlator is shown to be a function of the amplitude of the phase harmonics of the interference, the relative difference between the ranging tone and interference center frequencies (a function of rotor speed), the rangetone modulation indices, and the post-detection filter noise bandwidth.
New Research Results for Electronic Voting

Voting systems have become controversial in the years following the multiple election disasters that occurred in the United States during and after 2000. Of particular note were the electronic voting (e-voting) systems that were widely deployed to replace the pre-scored punch-card systems, systems that had have been frequently judged to be central to the problem in the 2000 Florida general election. The (premature) deployment of e-voting machines stimulated a new field of security and privacy research around the subject of elections, a subject that has turned out to be more complex and deeper than anyone would have predicted a decade ago. Here we present a sample of some of the finest recent work on election technology from authors on three continents.
When family members go to war--a systemic perspective on harm and healing: comment on Dirkzwager, Bramsen, Adèr, and van der Ploeg (2005).

The article by A. J. E. Dirkzwager, I. Bramsen, H. Ader, and H. M. van der Ploeg (2005; see record 2005-06518-006) provides compelling evidence of trauma transmission of posttraumatic stress symptoms (PTSS) from male peacekeepers to their female partners. Given the rise in troop deployment throughout the globe and increased exposure of soldiers to combat violence, the investigation is highly relevant, important and timely, illustrating the broad systemic emotional toll on couples when partners go to war. The purpose of this comment is to recommend future research directions (a) to reveal the characteristics of those individuals, couples, and family members that may be predictive of vulnerability and resiliency to PTSS and its sequelae; (b) to understand the interrelationship of PTSS and secondary trauma, relationship adjustment, and social support; and (c) to develop and test intervention methods that may be effective in reducing PTSS and other psychosocial problems among peacekeepers, their partners, and other family members.
Modeling the Engineering Information Professional

Summary This paper proposes a basic model for educating an information professional. Its premise is that there are three requirements that underlie all information service: (i) academic preparation in digital librarianship, (ii) education and practice to cultivate change management and interpersonal skills, and (iii) a practicum to develop technological perspective and to provide a future orientation. The paper also builds on the basic model to lay out a design for educating the engineering information professional. These additional elements include coursework in: (i) understanding the engineering literature and user community, and (ii) learning about the physical library systems and virtual information services and systems which underlie the practice of engineering.
Molecular Polymorphism of Kaposi's Sarcoma—Associated Herpesvirus (Human Herpesvirus 8) Latent Nuclear Antigen: Evidence for a Large Repertoire of Viral Genotypes and Dual Infection with Different Viral Genotypes

Molecular polymorphism was found in Kaposi's sarcoma-associated herpesvirus (KSHV) latent nuclear antigen (LNA), mapped to the internal repeat domain of the encoding orf73 gene, and used to develop a novel genotyping technique, KSHV LNA genotyping (KVNAtyping). KVNAtype was stable during latent and lytic viral replication in cell culture and in humans. Diverse KVNAtypes were identified in 43 specimens: 6 KSHV cell lines and 6 Kaposi's sarcoma (KS) and 4 primary effusion lymphoma (PEL) tumor samples from the United States, 15 KS tumor samples from Italy, and 12 KS tumor samples from Zambia. A single KVNAtype was detected in each of 41 specimens, and 2 KVNAtypes were detected in each of 2 KS specimens. Multifocal KS from 3 patients showed the same single KVNAtype at all sites in each patient. These results demonstrate a large repertoire of KSHV genotypes and suggest that the development of most KSs and PELs is associated with a single viral genotype.
The ligand effect on the isomer stability of Au24(SR)20 clusters

A key challenge in nanocluster research in particular and nanoscience in general is structure prediction for known compositions. Usually a simple ligand such as a methyl group is used to replace complex ligands in structure prediction of ligand-protected nanoclusters. However, how ligands dictate the energy landscape of such a cluster remains unclear. Here we elucidate the role of the ligand effect on the isomer stability of Au24(SR)20 nanoclusters by computing the relative energy of two isomers (one from the experiment, denoted as the “J” isomer; the other is the best theoretical model, denoted as the “P” isomer) of Au24(SR)20 with dispersion-corrected density functional theory. We find that when R = –CH3, the two isomers are equally stable (within 0.13 eV), but for R = –CH2CH2Ph the P isomer is more stable by 1.6 eV and for R = –CH2Ph-tBu the J isomer is more stable by 1.0 eV. Partition of the total energy into DFT and vdW contributions indicates that the higher stability of the P isomer in the case of R = –CH2CH2Ph stems from the stronger vdW interactions among –CH2CH2Ph groups, while the higher stability of the J isomer in the case of R = –CH2Ph-tBu is due to its better capacity to respond to the steric effect of the larger –CH2Ph-tBu groups. This finding confirms that the ligand plays a crucial role in dictating the isomer stability.
Numerical solution of non-linear Volterra integral equations

This paper deals with non-linear Volterra integral equations of the type y(x) = f(x) + ʃ0x H[t, x, y (t), y (x)] dt. Convergence criteria are given (in the same sense of the maximum and Ca norms) for the numerical solution of this type of Volterra integral equation. Several numerical methods are compared.
Constructing ρ/γ approximations for systems with No exogenous inputs

We consider discrete-time plants that interact with their controllers via fixed discrete alphabet sets, and that are not subject to exogenous inputs. For this class of systems, we propose a general procedure for constructing (finite state) ρ/γ approximations from input-output signals.
Modeling binocular vision: loss of 3-D in the presence of rivalry requires a new approach

In a dichoptic stimulus, where one feature in one eye could participate in both rivalry and stereopsis with features in the other eye, 3D perception was lost intermittently. The periods of loss of 3D percept were positively correlated with the periods of rivalrous suppression, and the degree of difference in rivalrous suppression between the eyes, due to variable eye dominance, was positively correlated with the degree of loss of 3D percept. This suggested that because differential luminance between the eyes affects their dominance in rivalry, stereopsis in the presence of rivalry would be similarly affected, and we now suggest that it is. These results are not predicted by any of the presently popular accounts of how rivalry and 'fusion' coexist. Instead, it seems that rivalry and 'fusion' are not two modular processes and that rivalry and stereopsis are affected by the same factors within an interactive network.
Engaging Field-Based Professionals in a Qualitative Assessment of Barriers and Positive Contributors to Breastfeeding Using the Social Ecological Model

Despite broad recognition of benefits associated with breastfeeding, rates in the United States continue to be below targets established by Healthy People 2020, especially for economically disadvantaged women. This study engaged field-based professionals through a focus group process to collect perceptions on factors that determine a woman's decision to breastfeed. Field-based professionals participated in one of six focus groups. Following the social ecological model (SEM), focus group questions addressed barriers and contributors to breastfeeding at the individual, interpersonal, community, organizational, and public policy levels. Thematic content analysis was used in identifying, analyzing, and reporting on themes within the focus group data. Commonly reported themes were identified that negatively influence a mother's decision to breastfeed such as modesty/general discomfort to breastfeed in front of others, negative breastfeeding perceptions of family members, friends, boyfriends and co-workers, breastfeeding not being viewed as the societal "norm", and the availability of free formula samples. Despite identified barriers, commonly reported themes that positively influence a mother's decision to breastfeed included general knowledge on the benefits, positive breastfeeding perceptions of family members, friends, boyfriends, and co-workers, the availability of "mom and baby" groups, and Baby Friendly hospital practices. The findings provide field-based perspectives that identify opportunities to support breastfeeding through the lens of the SEM. Opportunities to better support breastfeeding include educating mothers and their social support systems on the specific benefits of breastfeeding, challenging existing breastfeeding norms, and working with hospitals on establishing policy to not provide free formula samples.
The analysis of surface treatment of PDMS on prostate cancer and smooth muscle cells

The analysis of cellular activity when exposed to polydimethylsiloxane (PDMS) is necessary as this material has been used in various applications such as tissue engineering and microfluidic devices for cellular studies due to the polymer's unique mechanical properties. In this particular study, we investigated the effects of corona surface treated PDMS with different cross-linker ratios on cellular activities by analyzing prostate cancer cell (PC-3) and vascular smooth muscle cell (VSMC) adhesion and proliferation. Both cell lines were subjected to a thin PDMS layer immediately after and 24 hours after corona treatment. The results indicated steady cell adhesion and proliferation rates for both smooth muscle and prostate cancer cells when seeded onto PDMS 24 hours after corona surface treatment, but significantly less cell adhesion when seeded immediately after activation and controls (PDMS without any treatment). These results would allow future PC-3 and VSMC experiments to be performed in a PDMS environment that is not detrimental for adhesion and proliferation.
HEPATITIS C VIRUS INFECTION IN PEDIATRIC PATIENTS

In contrast to our understanding of hepatitis C virus infection in adults, relatively little is known about the evolution and treatment of HCV infection in pediatric patients. Children at risk for HCV infection include recipients of multiple blood-product transfusions, organ transplantation and infants born to HCV-infected mothers. A proportion of HCV-infected pediatric patients do not have an identifiable risk factor. HCV infection is commonly detected in children previously presumed to have non-A, non-B hepatitis and cryptogenic liver disease. HCV infection usually leads to mild chronic liver disease in children but is also associated with chronic active hepatitis and cirrhosis. Interferon therapy is effective in a proportion of patients with chronic hepatitis C.
Foundations and the Discourse of Philanthropy

Foundations make up a small but important segment of the nonprofit sector. Previous research has explored their contributions to social change and their relationships to grassroots organizations. The present research is concerned with how the foundations that fund such organizations contribute to the discourse of philanthropy. Using a discourse analysis to examine foundation documents and study text in context, this research finds that foundations are not ideologically invested in supporting the sociopolitical order, as critics claim, but are interested in preserving and promoting philanthropy's role in society, a finding with important ramifications for practice.
North Pacific climate response to freshwater forcing in the subarctic North Atlantic: oceanic and atmospheric pathways.

Abstract Sudden changes of the Atlantic meridional overturning circulation (AMOC) are believed to have caused large, abrupt climate changes over many parts of the globe during the last glacial and deglacial period. This study investigates the mechanisms by which a large freshwater input to the subarctic North Atlantic and an attendant rapid weakening of the AMOC influence North Pacific climate by analyzing four different ocean–atmosphere coupled general circulation models (GCMs) under present-day or preindustrial boundary conditions. When the coupled GCMs are forced with a 1-Sv (Sv ≡ 106 m3 s−1) freshwater flux anomaly in the subarctic North Atlantic, the AMOC nearly shuts down and the North Atlantic cools significantly. The South Atlantic warms slightly, shifting the Atlantic intertropical convergence zone southward. In addition to this Atlantic ocean–atmosphere response, all of the models exhibit cooling of the North Pacific, especially along the oceanic frontal zone, consistent with paleoclimate recons...
VALUE OF TRAFFIC ASSIGNMENT AND FLOW PREDICTION IN MULTIATTRIBUTE NETWORK DESIGN: FRAMEWORK, ISSUES, AND PRELIMINARY RESULTS

The well-defined concept of value of perfect information (VOPI) was used to assess the value of improving flow prediction and the relative value of improving components of the prediction system. The concept is introduced with a simplified example of choosing whether to build a highway segment in a corridor, and then the example is extended to a network and more realistic components are incorporated. The examples are worked through to illustrate the general approach, the types of results that could be obtained, and the issues that arise. The probability distributions of the attributes—cost, time, fuel consumption, and vehicle emissions—used to summarize uncertainty in prediction are important components when calculating VOPI. An approach to modeling these distributions and the flow distributions on which they are conditioned is presented. Unlike traditional approaches, the present one recognizes uncertainty in the model itself and not only in the inputs and parameters of the model. The VOPI of arc flows is...
Extratrigeminal Episodic Paroxysmal Hemicrania. Further Clinical Evidence of Functionally Relevant Brain Stem Connections

A woman, aged 59 years, developed a constant, left, occipital headache associated with episodes of discrete exacerbations occurring three to five times daily for 3 days, each lasting 15 to 20 minutes, and associated with left ptosis, conjunctival injection, and redness of the left ear. Pain-free remissions, which usually lasted 2 weeks, ceased after a mild neck injury, but the headaches responded promptly to indomethacin. This case, illustrating a transition from an occipital episodic to chronic paroxysmal hemicrania, is discussed as a variation of the trigeminal-autonomic cephalalgias.
Lin-28B transactivation is necessary for Myc-mediated let-7 repression and proliferation

Direct control of microRNA (miRNA) expression by oncogenic and tumor suppressor networks results in frequent dysregulation of miRNAs in cancer cells and contributes to tumorigenesis. We previously demonstrated that activation of the c-Myc oncogenic transcription factor (Myc) broadly influences miRNA expression and in particular leads to widespread miRNA down-regulation. miRNA transcripts repressed by Myc include several with potent tumor suppressor activity such as miR-15a/16–1, miR-34a, and let-7 family members. In this study, we have investigated mechanisms downstream of Myc that contribute to miRNA repression. Consistent with transcriptional down-regulation, Myc activity results in the decreased abundance of multiple miRNA primary transcripts. Surprisingly, however, primary transcripts encoding several let-7 miRNAs are not reduced in the high Myc state, suggesting a posttranscriptional mechanism of repression. The Lin-28 and Lin-28B RNA binding proteins were recently demonstrated to negatively regulate let-7 biogenesis. We now show that Myc induces Lin-28B expression in multiple human and mouse tumor models. Chromatin immunoprecipitation and reporter assays reveal direct association of Myc with the Lin-28B promoter resulting in transcriptional transactivation. Moreover, we document that activation of Lin-28B is necessary and sufficient for Myc-mediated let-7 repression. Accordingly, Lin-28B loss-of-function significantly impairs Myc-dependent cellular proliferation. These findings highlight an important role for Lin-28B in Myc-driven cellular phenotypes and uncover an orchestration of transcriptional and posttranscriptional mechanisms in Myc-mediated reprogramming of miRNA expression.
Cognitive theory and the SMSG program

Kilpatrick describes the curriculum program of the School Mathematics Study Group and its philosophy. Mathematical structure, rather than psychological theory, has played the instrumental role in shaping the program. An interesting issue is joined, essentially the same issue provoked by the Karplus paper, i.e., the issue of spontaneous aevelopment in children's thinking versus acceleration of this development through formal instruction and altering the child's experience. The compatibility of certain features of the SMSG curriculum with the results of Piaget's studies are enumerated. The paper concludes with a discussion of the National Longitudinal Study of Mathematical Abilities.
Evidence that DNA repair may not be modified by age or chronic caloric restriction

Pretreatment of animals with mixed-function oxidase inducers has been shown to increase the metabolic activation capacity of isolated hepatocytes resulting in an apparent increase in DNA repair. We recently reported decreases in chemically-induced DNA repair, measured as unscheduled DNA synthesis (UDS), in hepatocyte cultures isolated from aging ad libitum (AL) and caloric restricted (CR) diet-fed animals. In the present study, we evaluated the effects of pretreatment with Aroclor 1254 (ARO) on the genotoxicity of 4 carcinogens, from different chemical classes, in primary hepatocytes isolated from male Fischer 344 rats. ARO-induced old AL- and CR-derived cultures, treated with 2-acetylaminofluorene (2-AAF), aflatoxin B1 (AFB1), 7,12-dimethylbenz[a]anthracene (DMBA), and dimethylnitrosamine (DMN), exhibited significant induction-related increases in DNA repair in comparison to uninduced old AL and CR animals. These data indicate that the constitutive levels of specific cytochrome P450 decline with age and chronic caloric restriction, while the ability to respond to exogenous inducers is retained, and suggest that DNA repair may not be modified with age or diet restriction.
Autocrine-Controlled Formation and Function of Tissue-Like Aggregates by Primary Hepatocytes in Micropatterned Hydrogel Arrays

The liver carries out a variety of essential functions regulated in part by autocrine signaling, including hepatocyte-produced growth factors and extracellular matrix (ECM). The local concentrations of autocrine factors are governed by a balance between receptor-mediated binding at the cell surface and diffusion into the local matrix and are thus expected to be influenced by the dimensionality of the cell culture environment. To investigate the role of growth factor and ECM-modulated autocrine signaling in maintaining appropriate primary hepatocyte survival, metabolic functions, and polarity, we created three-dimensional cultures of defined geometry using micropatterned semisynthetic polyethylene glycol–fibrinogen hydrogels to provide a mechanically compliant, nonadhesive material platform that could be modified by cell-secreted factors. We found that in the absence of exogenous peptide growth factors or ECM, hepatocytes retain the epidermal growth factor (EGF) receptor ligands (EGF and transforming growt...
Undergraduate and graduate students' attitudes towards AIDS.

Since its discovery in 1981, Acquired Immune Deficiency Syndrome (AIDS) has been the source of great fear and controversy. Fear stems from uncertain risks of contagion and almost certain death once the syndrome has fully developed. AIDS has produced a number of social issues because the majority of A~S victims have been homosexual men, parenteral drug users, and minorities such as Haitian refugees (McLeod & Miller, 1985). Rights have been denied to its vinms (to maintain employment or to go to school, for instance), and misinformation appears to be influencing attitudes towards blood donation and the gay lifestyle. With no known cure for AIDS and medical consensus that a vaccine is several ycars away, human service professionals will continue to have important roles in directly serving and advocating for ADS victims, as well as educating the ill-informed. Several authors have delineated the roles of helping professionals with regard to Ams (Furstenberg & Olson, 1984; Lopez & Geael, 1984; Caputo, 1985; Baumgartner, 1985). However, wich the exception of a study which essentially explored homophobia among physicians and nurses (Douglas, Kalman, & Kalman, 1985) there is practically no research on the attitudes of professionals or professionals in training regarding AIDS victims. The purpose of this research was to explore how fear of ADS may be associated with knowledge about AIDS and empathy towards AIDS victims, using an available sample of undergraduate and graduate students enrolled at the University of Kentucky. The effects of age, sex, race, and years of education on fear of AIDS were also examined. In the sample of 219 respondents 86 (39%) were undergraduate social work majors and 79 (36%) were graduate students in social work. The balance of the respondents (54) had other undergraduate majors. The mean age of the respondents was 27.8 yr. (range, 19 to 59 yr.). The majority were white (86%) and women (74%) A questionnaire using a >-point Likert-type response scale was consuucted from 3. review of salient issues appearing in the popular press. Three scales, a Knowledge Scale, a Fear Scale, and an Empathy Scale were devised from items on the instrument. The Knowledge Scale was created by summing the responses to three items (a = 66). These items asked whether the respondent agreed or disagreed with statements regarding the possibility of getting A~S from toilet seats in public restrooms or from gay employees of restaurants. The third item asked the respondents to rate their agreement or disagreement with the statement, "Over-all, I think I am well-informed about AIDS." Scores ranged from the possible 3 to 15 (M = 10.4, SD = 2.5). The Fear Scale had six items (a = .67) on which the respondent agreed or disagreed chat persons having AIDS should be quarantined, registered with the local health
Allopurinol and lodoxamide in complement-induced hepatic ischemia☆

Intravascular complement activation with either zymosan or cobra venom factor (CVF) impairs hepatic blood flow. Oxygen radical scavengers given at the time of complement activation attenuate the resulting hepatic ischemia. It is not clear whether complement-stimulated phagocytes or transiently ischemic then reperfused endothelial and parenchymal cells generate the toxic oxygen radicals. In this study, a group of rats were given allopurinol (50 mg/kg/day postoperatively × 3 days plus 100 mg/kg iv at t = 0), a specific inhibitor of xanthine oxidase, prior to complement activation with CVF (20 units/kg iv at t = 30 and 60 min) to determine whether xanthine oxidase-derived oxygen radicals contributed significantly to the hepatic perfusion abnormalities. Additional rats received lodoxamide tromethamine (10 mg/kg iv bolus at t = 0 followed by 20 mg/kg/hr iv infusion), a novel and potent inhibitor of mast cell release and inhibitor of xanthine oxidase, prior to the same CVF challenge to determine whether mast cell mediators were involved in the flow disturbance. Thermodilution cardiac output, mean arterial pressure, heart rate, hematocrit, and effective hepatic blood flow (EHBF) by galactose clearance were determined at t = 2 hr. The percentage change in total hemolytic complement activity (% ΔCH50) was determined between serum obtained prior to sacrifice and at t = 0. Systemic hemodynamics and HCT were for the most part unaffected regardless of pretreatment group or challenge with CVF or saline. CVF challenge produced a 25% reduction (P < 0.05) in EHBF in vehicle-pretreated rats compared to saline challenge. Neither allopurinol nor lodoxamide tromethamine significantly improved EHBF when given prior to CVF challenge. In phagocytes, the NADPH oxidase system generates superoxide anions during a respiratory burst. Neither neutrophil superoxide production nor degranulation is affected by allopurinol. Endothelial and parenchymal cell superoxide formation is coupled to xanthine oxidase-dependent purine metabolism. Because superoxide dismutase plus catalase, but not allopurinol, improves hepatic perfusion after intravascular complement activation, we can infer that phagocytes are the likely cells of origin of the pathogenic oxygen radicals.
Molecular modulation of allergic responses

Abstract The pathophysiology of allergic diseases involves an intricate network of molecular and cellular interactions. Elevated levels of serum IgE– and T H2 cytokine–associated eosinophilic inflammation characterize allergic diseases and provide potential targets for immunomodulation. Recent evidence that antigen-induced allergic responses can be modulated in rodents by mucosal transfer of T H1 -cytokine genes or by immunization with plasmid DNAs encoding the sensitizing antigens suggests promising new prophylactic or therapeutic approaches. Innovative research in mapping the regulatory pathways that typify the atopy network will provide a deeper understanding of the molecular mechanisms underlying these diseases and facilitate the design of more specific and efficacious modulation strategies. (J Allergy Clin Immunol 1998;102:887-92.)
Indexing in video databases

A video database provides content based access to video. This is achieved by organizing or indexing video data based on some set of features. This paper defines the problem of video indexing based on video data models. The procedure required to index video data is outlined. The use of semi-automatic techniques to speed up the indexing processes are explored. These techniques use image motion features to aid in the indexing process. The techniques developed have been applied to video data from cable television feed.
On the Microscopic Conditions for Linear Macroscopic Laws

We have investigated the conditions which must be imposed on the microscopic equations of motion to obtain exact linear laws for macroscopic (phase averaged) variables. The starting point in this study has been the lowest order master equation (Pauli equation) which is a linear microscopic equation in the state probabilities with a time‐independent transition matrix. Discrete and continuous variable master equations as well as their multivariate generalizations have been considered. In the case of continuum state variables, we have used various Fokker‐Planck equations and their corresponding Langevin equations as our starting microscopic equation of motion. In each case the conditions which must be imposed to obtain linear macroscopic transport equations have been derived and discussed. The problem of the derivation of linear macroscopic laws from microscopic laws which are nonlinear in the dynamical variables has been discussed in the context of our results. We find that exact linear macroscopic laws can...
Initial comparison of robotic-assisted laparoscopic versus open pyeloplasty in children

Abstract Objectives To compare the initial results of robotic-assisted laparoscopic versus open pyeloplasty in children with ureteropelvic junction obstruction. Methods From June 2002 to July 2004, 8 pediatric patients underwent robotic-assisted laparoscopic pyeloplasty and were matched by age group with patients undergoing conventional open pyeloplasty. The mean age was 11.5 years (range 6.4 to 16.5) in the robotic-assisted group and 9.8 years (range 6.0 to 15.6) in the open group. A four-port transperitoneal technique was used to perform the Anderson-Hynes pyeloplasty with the da Vinci Surgical System. Results The mean operative time and estimated blood loss was 363 minutes (range 255 to 522) and 13.1 mL (range 5 to 25) in the robotic-assisted group versus 248 minutes (range 144 to 375) and 53.8 mL (range 5 to 200) in the open group, respectively. The mean length of hospitalization and pain medication use was 2.4 days (range 1 to 5) and 7.4 mg morphine (range 0 to 23) in the robotic-assisted group compared with 3.3 days (range 1 to 8) and 22.0 mg morphine (range 0 to 100) in the open group, respectively. At a mean follow-up of 14.7 months (range 2 to 24), all robotic procedures were successful as determined by subjective data using pain scales and radiologic data. Conclusions Robotic-assisted laparoscopic pyeloplasty appears to decrease the length of hospitalization and use of pain medication, but has a longer operative time. Additional clinical experience is required to determine the long-term efficacy of this method.