cssi/SciSciGPT-SciSciNet huggingface dataset:
Kauffman's abstract model of phase transitions

According to Kauffman's abstract model (1995), a phase transition occurs when free nodes become interconnected through random linking. Despite the randomness of the process, the general patterns that it produces are idiosyncratic and highly predictable, demonstrating the universality of the phase transition phenomenon and its independence of the physical interpretation of the nodes and links. To make it more representative of real materials, the model was modified by introducing rules that restrict the distance between the nodes that are allowed to connect. This produced transition patterns that were very similar to those produced by allowing any pair of nodes to connect, and with a very similar cluster size distribution. The model does not account for all the specific mechanisms of phase transitions that cause the hardening of foods. But it does offer at least a partial explanation as to why certain consistent patterns emerge regardless of a food's variability at the molecular and microstructural levels, and it emphasizes the random character of the interactions between its components.
Unique transforming gene in carcinogen-transformed mouse cells

Observations from various biological systems suggest that chemical carcinogens transform cells by causing somatic mutations through interacting with DNA1–5. These observations raise several fundamental questions regarding the nature of the transforming genes that are the target of the carcinogens. For example, are there unique target gene(s) for chemical carcinogens, or are there multiple potential targets, any of which, when altered, can induce the transformed phenotype? This problem has been approached previously by comparing the rate of transformation by chemical carcinogens with the rate of appearance of dominant mutations in unique cellular genes encoding selectable markers. The results suggested a limited number of targets for transformation, since transformation occurred at a rate that was only 10–100 times greater than the appearance of ouabain-resistant mutants6–8. These results, however, are only rough estimates, because the optimal conditions for induction of transformation and the induction of mutations are known to differ6. In addition, lesions other than point mutations caused by carcinogens, such as frame-shifts, may induce transformation efficiency but not ouabain resistance. We now present an alternative experimental approach to estimating the number of targets for chemical carcinogens, based on the fact that DNAs of certain chemically transformed cell lines can induce the appearance of foci when transferred on to NIH3T3 cells9. These DNAs were treated with a variety of restriction endonucleases before testing their transforming activities by DNA transfer. We have found the same pattern of sensitivity and resistance to inactivation by different endonucleases in all DNAs studied, suggesting that the same transforming gene is being transferred in all cases.
Physicians' attitudes about referring their type 2 diabetes patients for bariatric surgery.

Abstract Background Despite increasing evidence about the beneficial effects of bariatric surgery, little is known about physicians' attitudes toward it as a treatment of type 2 diabetes. Our objective was to investigate physicians' attitudes about referring patients with type 2 diabetes for bariatric surgery. Methods Physicians were identified from the Pennsylvania Integrated Clinical and Administrative Research Database and other databases. Physicians at an academic medical center (n = 142) and community-based physicians (n = 197) in the Philadelphia area in specialties likely to treat type 2 diabetes were sent a survey about their perceptions of the safety and efficacy of bariatric surgery as a treatment for obesity and type 2 diabetes. Results Of the physicians, 93 returned the survey, for a combined response rate of 27.4%. Respondents reported having positive impressions of bariatric surgery as a treatment for obesity and type 2 diabetes (79.6% and 67.4%, respectively). Only 20.8% of respondents indicated that they would be likely to refer their patients with type 2 diabetes with a body mass index of 30–34.9 kg/m 2 to a randomized research trial of bariatric surgery. Conclusion In general, physicians who treat patients with type 2 diabetes had favorable impressions about bariatric surgery as a treatment for obesity and type 2 diabetes. However, only a few were willing to refer their patients with type 2 diabetes and a body mass index of 30–34.9 kg/m 2 to randomized research trials of bariatric surgery. This reluctance to refer patients represents an important barrier to the successful completion of studies of the efficacy of bariatric surgery for those with type 2 diabetes and a body mass index 2 .
Seasonal and interannual variability of the characteristics of Scotia-Sea front based on the satellite measurements of sea-surface temperature

We determine the characteristic features of the space structure of the Scotia-Sea Front and study the variations of its characteristics on the seasonal and interannual scales. It is shown that, in the climatic seasonal cycle, the Scotia-Sea Front is intensified in the warm period of the year when the temperature contrast between the cold waters formed as a result of thawing of ice and warmer waters transported by the South Branch of the Antarctic Circumpolar Current becomes more pronounced. The maximum seasonal variations of the intensity of this front are observed in the region of minimum intraannual displacements of the boundary of drift ice. The interannual variations of the characteristics of the front are observed in the form anomalous variations of its intensity and latitudinal displacements. A significant relationship is established between the interannual anomalies of the characteristics of the front and the areas of warm tropical waters in the Pacific Ocean caused by the events of El Nino.
Expression of alu and 7SL RNA in Alzheimer's and control brains

Abstract We investigated whether changes in expression of RNA polymerase III (pol III) or heterodisperse RNA polymerase II (pol II) transcripts hybridizing to Alu could be detected in Alzheimer's disease (AD). RNA samples obtained from AD and control brain tissues were examined by Northern analysis for Alu and 7SL RNA expression. All RNA samples contained a prominent band of approximately 300 nucleotides which corresponds to 7SL RNA, the Alu-homologous RNA component of the signal recognition particle. In addition, three small (i.e.
Intermolecular Dehydrative Coupling Reaction of Arylketones with Cyclic Alkenes Catalyzed by a Well-Defined Cationic Ruthenium-Hydride Complex: A Novel Ketone Olefination Method via Vinyl C–H Bond Activation

The cationic ruthenium−hydride complex [(η6-C6H6)(PCy3)(CO)RuH]+BF4− was found to be a highly effective catalyst for the intermolecular olefination reaction of aryl ketones with cycloalkenes. The preliminary mechanistic analysis revealed that an electrophilic ruthenium−vinyl complex is the key species for mediating both vinyl C−H bond activation and the dehydrative olefination steps of the coupling reaction.
What are the most common title words in technical communication publications

While titles are an important component of scholarly and trade publications, they have been understudied within the field of professional and technical communication. In particular, the field has not empirically analyzed the titles of publications within our discipline. Such empirical study can present a clearer picture of how our field has evolved and what are the theoretical and practical tenets of our discipline. In this study, we begin to explore these issues. First, in a corpus that includes the title of every article published in the five major technical communication scholarly publications and the one trade publication between 1996 and 2013, we determine what the most common words used within titles are. We then determine what words are unique to scholarly publications or trade publications. Finally, we explore how the common words have changed over time.
Strategic planning for video-assisted thoracic surgery

As with any operative procedure, careful preoperative and intraoperative planning are vital to achieving a safe and effective video-assisted thoracic surgical intervention. We outline some of our basic strategies for enhancing the success of this approach in the management of thoracic surgical problems.
Conceptual Styles, Culture Conflict, and Nonverbal Tests of Intelligence

Conceptual styles are rule-sets for the selection and organization of sense data. Two mutually incompatible conceptual styles are identified—relational and analytic. Relational and analytic methods of conceptual organization appear to have been developed and reinforced in shared-function and formally organized primary groups, respectively, as socialization settings. Each style affects its carrier's ability to deal effectively with the alternate kind of group process requirements. A distinction is drawn between culture conflict and related notions of deprivation and culture difference. When the conceptual styles used between individuals and groups are mutually incompatible, culture conflict may be said to exist, whether or not the other phenomena are also present. It is found that highly relational pupils in the analytic school environment represent this type of culture conflict regardless of their native ability or the variety and relevance of their experience backgrounds. This difficulty is not obviated by developing context-free situations. Item solution requirements for common nonverbal tests of intelligence, for instance, focus directly on expertise in using the analytic rule-set as a measure of intelligence. Their culture bias has, thus, not been reduced but has been moved to a higher level of abstraction. Conceptual rule-sets also affect the assimulation of experience content. They determine to a great extent the number and nature of contextual attributes that will appear relevant to individuals. In addition, because a wide variety of social and psychological behaviors are meaningful only when they follow from these rule-sets, conceptual styles contribute to the formation of logically derived normative systems.
New Satellite Technologies Enhance Study of Terrestrial Biosphere

Since 1984, when global observations of terrestrial vegetation were first made using the Advanced Very High Resolution Radiometer (AVHRR), Earth scientists have developed a host of new techniques for studying the biosphere. Many recent papers have used the Normalized Difference Vegetation Index (NDVI) to quantify large-scale changes in global vegetation from the early 1980s through the present. Global NDVI time series data have even provided evidence that spring vegetation growth is occurring earlier and enhancing the carbon sink of temperate latitudes in the Northern Hemisphere
Isotopic investigation of niche partitioning among native carnivores and the non-native coyote (Canis latrans).

We employed stable carbon (δ13C) and nitrogen (δ15N) isotopes within a hypothetico-deductive framework to explore potential resource partitioning among terrestrial mammalian carnivores. Isotope values were acquired using guard hair samples from bobcat (Lynx rufus), coyote (Canis latrans), gray fox (Urocyon cinereoargenteus), and red fox (Vulpes vulpes) in the Adirondack Park, NY, USA. Enrichment along the δ13C axis was expected to reflect the use of human sources of food (reflecting a corn subsidy), and by extension tolerance for human-modified environments, whereas enrichment along the δ15N axis was expected to reflect a higher level of carnivory (i.e. amount of animal-based protein in the diet) – two mechanisms by which these now sympatric species may achieve a dynamic coexistence. Although bobcats were the only obligate carnivore, all four species shared a similar δ15N space. In contrast, bobcat had a lower and distinct δ13C signature compared to foxes, consistent with the a priori expectation of bobca...
Film Morphology of High Efficiency Solution‐Processed Small‐Molecule Solar Cells

Morphological control over the bulk heterojunction (BHJ) microstructure of a high-efficiency small molecule photovoltaic system is demonstrated using both thermal treatment and solvent additive processing. Single crystal X-ray diffraction is utilized to understand molecular interactions in the solid state and the BHJ morphology is examined using bright field, high-resolution, and cross-section transmission electron microscopy techniques. Controlling the domain size, while maintaining good molecular order within the semiconducting donor material, is found to be crucial in achieving high performance and over 90% internal quantum efficiency exhibited under the optimized conditions.
Fast and Globally Convergent Nonlinear System Model for 3D Magnetostrictive Systems

A globally convergent and fully coupled magnetomechanical model for 3D magnetostrictive systems is presented. In magnetostrictive actuators, magnetic field and stress inputs generate magnetic flux density and strain. We refer to models that follow this scheme as direct models (no relation to the direct magnetomechanical effect). In certain design and control situations, inverse models are necessary in which the magnetic field and stress are found from specified magnetic flux density and strains. This inversion typically involves an iterative procedure, which may be prone to convergence issues. An inverse model approach is proposed for arbitrary magnetostrictive materials. The inversion requirement is a continuous and second order differentiable direct model for any chosen magnetostrictive material. The approach is globally convergent, which makes it ideal for use in finite element frameworks. The premise of the proposed iterative system model is to constitute a recursive correction formula based on second order approximations of a novel scalar error function which allows to achieve a faster convergence rate. A continuation approach is then used to achieve global convergence for arbitrary input parameters. To illustrate, Galfenol is chosen as the magnetostrictive material, and analytical derivations of the Jacobian and Hessian matrices are presented. Finally, the computational efficiency of the proposed approach is shown to compare favorably against existing models.Copyright © 2014 by ASME
Emerging molecular markers of cancer

Alterations in gene sequences, expression levels and protein structure or function have been associated with every type of cancer. These 'molecular markers' can be useful in detecting cancer, determining prognosis and monitoring disease progression or therapeutic response. But what is the best way to identify molecular markers and can they be easily incorporated into the clinical setting?
The Value of an Integrated Information System: A Case of an Out-Patient Clinic

Outpatient clinics are demanding environments. It's crucial to provide with patients with safe, high-quality care. It's important that clinics run effectively and efficiently. This research proposed an integrated information system within the context of outpatient clinic, including both the DB and the user interface design. We will also compare the existed clinic system with the proposed system, and expose the value of this integrated system using collected data.
Use of phosphorothioate analogs of poly(dA‐dT) · poly(dAdT) to study steroidal‐diamine induced conformational change in poly(dA‐dT) · poly(dA‐dT)

Introduction of phosphorothioate groups into the backbone of poly(dA-dT) allows one to label the d(ApT) and d(TpA) phosphate resonances in the 31P NMR spectrum. Upon binding the steroidal diamine dipyrandenium to poly d(AsT) and poly d(TsA), 31P NMR shows that it is the d(ApT) phosphodiester bond which is most perturbed. Other work has shown that 2 M Cs+ causes the same 31P shift. The DNA conformational change induced by both cations probably involves a narrowing of the minor groove.
Nonlinear response of a beam under distributed moving contact load

Abstract In this paper, the nonlinear behavior of a one-dimensional model of the disc brake pad is examined. The contact normal force between the disc brake pad lining and rotor is represented by a second order polynomial of the relative displacement between the two elastic bodies. The frictional force due to the sliding motion of the rotor against the stationary pad is modeled as a distributed follower-type axial load with time-dependent terms. By Galerkin discretization, the equation governing the transverse motion of the beam model is reduced to a set of extended Duffing system with quasi-periodically modulated excitations. Retaining the first two vibration modes in the governing equations, frequency response curves are obtained by applying a two-dimensional spectral balance method. For the first time, it is predicted that nonlinearity resulting from the contact mechanics between the disc brake pad lining and rotor can lead to a possible irregular motion (chaotic vibration) of the pad in the neighborhood of simple and parametric resonance. This chaotic behavior is identified and quantitatively measured by examining the Poincare maps, Fourier spectra, and Lyapunov exponents. It is also found that these chaotic motions emerge as a result of successive Hopf bifurcations characterized by the torus breakdown and torus doubling routes as the excitation frequency varies. Various aspects of the numerical difficulties in the solution of the nonlinear equations are also discussed.
Lithium intolerance in a medical-psychiatric population.

This pilot study was designed to explore the tolerance and efficacy of lithium as an adjunctive prophylactic agent when added to maintenance antidepressant regimens following an episode of depression in an older medical-psychiatric population. In a randomized controlled trial, 27 depressed patients had either lithium carbonate or placebo added to their maintenance antidepressant (AD) regimen following an index episode of depression. Of 17 patients who received lithium carbonate, 76% (13/17) were unable to tolerate this agent for the duration of the study because of side effects (e.g., gastrointestinal disturbances or tremor). The four patients who tolerated lithium were monitored for relapse of depression over a 15-month follow-up period, and one relapsed (after a 49-week remission), whereas 60% (6/10) of the placebo patients relapsed. Cognitive functioning was stable in the lithium-treated patients who remained on therapy. The high rate of lithium intolerance in this study indicates that lithium dosing and serum levels must be conservatively managed in this clinical population.
MicroRNA‐34a is an important component of PRIMA‐1‐induced apoptotic network in human lung cancer cells

Restoration of p53 function in tumor cells would be an attractive strategy for lung cancer therapy because p53 mutations are found in more than 50% of lung cancers. The small molecule PRIMA-1 has been shown to restore the tumor suppression function of p53 and to induce apoptosis in human tumor cells. The mechanism of apoptosis induced by PRIMA-1 remains unclear. We investigated the effects of PRIMA-1 in apoptosis with Western immunoblot analysis, TaqMan microRNA real-time PCR, cell viability analysis and flow cytometry using human lung cancer cell lines containing mutant (H211 and H1155), wild-type (A549) or null (H1299) p53. PRIMA-1 induced massive apoptosis in the H211 and H1155 cells, but was less toxic to the A549 and H1299 cells. Western immunoblot analysis showed cleavage of PARP in H211 and H1155 cells but not in A549 and H1299 cells following treatment with PRIMA-1. In addition, p53 protein was also phosphorylated in H211 and H1155 cells. TaqMan microRNA assay showed that the expression of microRNA-34a was increased in the H211 and H1155 cells posttreatment. Knockdown microRNA-34a decreased the rate of apoptosis caused by PRIMA-1. The above results suggest that microRNA-34a is one of the important components of PRIMA-1-induced apoptotic network in the cancer cells harboring mutant p53.
Transhepatic hemodialysis catheters: functional outcome and comparison between early and late failure.

Abstract Purpose To describe the authors' experience with transhepatic placement of catheters, highlighting early and late complications, and to determine if this procedure is a viable option in patients in whom central venous occlusions present a significant challenge. Materials and Methods The records of all the patients who underwent placement of transhepatic hemodialysis from January 2003 to October 2008 were retrospectively reviewed. Selected patients were dialysis-dependent, having undergone multiple access procedures and revisions. Kaplan-Meier analysis was used to estimate primary and secondary patency. Results Twenty-two patients (mean age 42 years, range 22–70 years, 59% women) underwent a total of 127 transhepatic catheter placements at 24 transhepatic access sites; technical success was achieved in all cases. There were no hepatic injuries (bleeding or fistula formation). There were 105 exchanges in 14 patients, with a mean of 7.5 exchanges, a median of 5 exchanges (range 1–18 exchanges), and a catheter migration rate of 0.39 per 100 catheter-days. The sepsis rate was 0.22 per 100 catheter-days, and the catheter thrombosis rate was 0.18 per 100 catheter-days. The mean cumulative catheter duration in situ was 506.2 days, and the mean time catheter in situ was 87.7 days. The mean total access site interval was 1,046 catheter-days (range of 423–1,413 catheter-days). Conclusions Transhepatic hemodialysis catheter placement is associated with low rates of morbidity. In this series, transhepatic catheters provided the possibility of long-term functionality, despite associated high rates of catheter-related maintenance, provides a potentially viable access for patients with exhausted access options.
Chromosomal domains of chimpanzee are diverged from human as revealed by in situ hybridization using human genomic probe

Utilization of repetitive DNA probes to assess the taxonomic affinity between related species has become the most powerful tool in evolutionary biology today. Consequently, tremendous strides have recently been made towards establishing the phylogenetic relationship of humans with chimpanzee. We employed human genomic proe (P5080 B.5) to identify the degree of divergence of chimpanzee genome from humans. A small protion of structurally distinct genomic areas in chimpanzee could be identified by fluorescencein situ hybridization (FISH) technique when compared to human DNA. The genomic divergence is confined mainly to the chromosomal ends in chimpanzee and may be an important phylogenetic characteristic in human evolution.
Gestational diabetes: Does the presence of risk factors influence perinatal outcome?

Abstract Objective: Our purpose was to determine whether gestational diabetics with risk factors for gestational diabetes have worse glucose tolerance and poorer birth outcomes than those without risk factors. Study Design: We conducted a nonconcurrent cohort study of gestational diabetics identified by universal screening and delivered from Jan. 1, 1990, to Dec. 31, 1992. Multiple gestations and patients with chronic medical conditions were excluded. The following risk factors for gestational diabetes mellitus were abstracted: obesity (> 80 kg), family history of diabetes, previous gestational diabetes mellitus, and previous macrosomic, stillborn, or anomalous fetus. Patients with one or more risk factors were compared with those without risk factors. A group of low-risk nondiabetic patients served as controls. The incidences of A 2 diabetes mellitus, cesarean section, neonatal macrosomia, and shoulder dystocia were the outcome variables of interest. Results: Selective screening would have failed to detect 43% of gestational diabetics. Twenty-eight percent of the missed gestational diabetics would have required insulin (class A 2 ). When compared with controls, patients with gestational diabetes mellitus were at increased risk for macrosomia (26% vs 11 %, p p p Conclusion: Gestational diabetics are at increased risk for adverse birth outcomes compared with low-risk controls. Class A 2 diabetes mellitus and fetal macrosomia with its attendant risks are equally prevalent among patients with and without risk factors for gestational diabetes mellitus. Because>40% of cases ill be missed with selective screening, universal screening should be favored for detection of gestational diabetes mellitus.
Abstract 1324: Modulation of IR induced NFKB activity by manipulation of NOS coupling

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC The transcriptional activity of NFκβ is in part regulated by nitric oxide (NO) and reactive nitrogen species (RNS). Previously we demonstrated that low doses of ionizing radiation (IR) activate constitutive, Ca2+ dependent NO Synthases (NOS) and the generation of RNS, resulting in protein Tyr nitration and/or Cys s-nitrosylation. Previous studies in our lab demonstrated that nitration of IκBα is critical for the IR-induced activation of NFκβ whereas others have shown that s-nitrosylation of the p65 subunit leads to the inhibition of NFκβ. Here we show that exposing MCF-7 cells to 5Gy IR results not only in Tyr nitration of IκBα but also Cys s-nitrosylation of NFκβ both with a maximum at 30min. post IR. One explanation for the discordant results is that NOS activity is uncoupled, resulting in the production of increased levels of superoxide anion as opposed to NO. Tetrahydrobiopterin (BH4) is a necessary cofactor that stabilizes the enzyme and allows the generation of NO through oxidation of L-arginine. However, if BH4 levels become limiting as found in chronic inflammatory or oxidative conditions, electron transfer is instead shuttled to molecular oxygen resulting in the production of superoxide anion, a scenario in which NOS is described as “uncoupled.” When NOS is uncoupled the resulting increase in superoxide can lead to enhanced levels of peroxynitrite formation, resulting in enhanced IκBα Tyr nitration and NFκβ activity. This evidence has led to the hypothesis that by altering cellular levels of BH4, the levels of Tyr nitration and Cys s-nitrosylation can be manipulated, leading to changes in NFκβ activity. To determine the effects of exogenous BH4 on IκBα nitration in MCF-7 cells, cells were treated with varying concentrations of cell permeable sepiapterin (SP), a precursor of BH4, and exposed to 5Gy IR. The results show that between 100nM-500nM IκBα nitration is all but completely eliminated, resulting in decreased NFκβ activity as assessed by luciferase assay. Initial experiments looking at the effects of SP on p65 s-nitrosylation have been variable. At a minimum, levels of s-nitrosylation remain the same as untreated cells; however, enhancement of s-nitrosylation is seen in some experiments. Studies are ongoing to clarify SP's effects on p65 s-nitrosylation as well as studies to determine SP's effects on tumor cell survival post IR. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1324.
The balance of care: Trends in the wages and employment of immigrant nurses in the US between 1990 and 2000

Abstract Recently, the transnational migration of nurses from developing countries to developed countries has received heightened attention from policymakers, health-care practitioners, and the media. In this article, the 1990 and 2000 Census Public Use Micro Survey (PUMS) data files are used to address the issue of nurse migration. I examine changes in the number, location, wages, countries of origin, and other economic and demographic variables for foreign-born nurses and nurses' aides and US born nurses and nurses' aides over the time period 1990 to 2000. I find that foreign-born nurses and nurses' aides increasingly come from developing countries and, specifically, from Africa. This raises important ethical issues, as Africa faces a severe shortage of nurses in the context of the AIDS crisis. Foreign-born nurses are shown to have higher levels of education and higher levels of labor force attachment than US-born nurses.
Mosquito Gonotrophic Cycle and Multiple Feeding Potential: Contrasts Between Anopheles and Aedes (Diptera: Culicidae)

Two aedine and three anopheline species were allowed to blood-feed to repletion, and their host-seeking behavior was measured with an olfactometer at intervals afterward. Both Aedes aegypti (L.) and Ae. albopictus (Skuse) were inhibited from subsequently seeking a host during the gonotrophic cycle, but Anopheles gambiae Giles, An. albimanus Wiedemann, and An. freeborni Aitken, all showed varying degrees of host-seeking behavior while their eggs matured. Continued host-seeking by some anophelines during the gonotrophic cycle has important implications for some assumptions commonly made about mosquito behavior and parasite transmission.
Contrast-agent-enhanced magnetic resonance imaging: early detection of neoplastic lesions of the CNS

Even though the intrinsic soft tissue contrast sensitivity of magnetic resonance imaging (MRI) affords excellent visualization of anatomic detail, certain pathologic processes may be diagnosed earlier with the administration of a contrast-enhancing agent. At present there is one agent, gadopentetate dimeglumine, GdDTPA, that has received FDA approval for use in the MR scanning of the brain and spine in human patients. This paramagnetic chelate distributes throughout the extracellular fluid space as dictated by capillary permeability so that abnormal vascularity and sites of blood-CNS barrier breakdown are highlighted. Primary neoplastic disease, metastases, meningeal extension, residual and recurrent tumor have been found to be better distinguished in MR images acquired after administration of GdDTPA. Routine administration of GdDTPA for cranial imaging has resulted in the discovery of otherwise occult lesions in approximately 3 of patients. Although the clinical utility and high therapeutic safety index of the first approved magnetic resonance contrast agent, GdDTPA, have been well established, other contrast agents, having different physical, chemical and biological properties, may offer improved sensitivity and bio-specificity. Agents currently being evaluated in vivo include: low osmolal paramagnetic chelates, superparamagnetic particles, metalloporphyrins, liposome encapsulated agents, perfluorocarbons, intravascular macromolecular chelate complexes and labeled monoclonal antibodies. Concurrent with advances in the development of new compounds, innovations in scanning hardware, pulse sequence design and image post-processing are helping to extend the efficacy of contrast media. Additional clinical experience will indicate which contrast agents and which MR techniques can best facilitate the early detection of specific neoplastic lesions.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
System Theory on Group Manifolds and Coset Spaces

The purpose of this paper is to study questions regarding controllability, observability, and realization theory for a particular class of systems for which the state space is a differentiable manifold which is simultaneously a group or, more generally, a coset space. We show that it is possible to give rather explicit expressions for the reachable set and the set of indistinguishable states in the case of autonomous systems. We also establish a type of state space isomorphism theorem. Our objective is to reduce all questions about the system to questions about Lie algebras generated from the coefficient matrices entering in the description of the system and in that way arrive at conditions which are easily visualized and tested.
Partial Randomization of the Four Sequential Amidation Reactions Catalyzed by Cobyric Acid Synthetase with a Single Point Mutation

Cobyric acid synthetase (CbiP) from Salmonella typhimurium catalyzes the glutamine and ATP-dependent amidation of carboxylates b, d, e, and g within adenosyl cobyrinic acid a,c-diamide. After each round of catalysis the partially amidated intermediates are released into solution and the four carboxylates are amidated in the sequential order of e, d, b, and g for the wild type enzyme. In the presence of [gamma-18O4]-ATP and adenosyl cobyrinic a,c-diamide the enzyme will catalyze the positional isotope exchange of the betagamma-bridge oxygen with the two beta-nonbridge oxygens. These results support the proposal that ATP is used to activate the carboxylate groups via the formation of a phosphorylated intermediate. CbiP catalyzes the hydrolysis of glutamine in the absence of ATP or adenosyl cobyrinic acid a,c-diamide, but the rate of glutamine hydrolysis is enhanced by a factor of 60 in the presence of these two substrates together. This result suggests that the formation of the phosphorylated intermediate is coupled to the activation of the site utilized for the hydrolysis of glutamine. However, the rate of glutamine hydrolysis is approximately 2.5 times the rate of ADP formation, indicating that the two active sites are partially uncoupled from one another and that some of the ammonia from glutamine hydrolysis leaks into the bulk solution. The mutation of D146 to either alanine or asparagine results in a protein that is able to catalyze the formation of cobyric acid. However, the strict amidation order observed with the wild type CbiP is partially randomized with carboxylate b being amidated last. With the D146N mutant, the predominant pathway occurs in the sequence d, e, g, and b. It is proposed that this residue enforces the amidation order in the wild type enzyme via charge-charge repulsion between the side chain carboxylate and the carboxylates of the substrate.
A confidence-prioritisation approach for learning noisy data

In a number of real-world applications, there is a range of noise associated with individual data points. Some points are extracted under relatively clear and defined conditions, while others may be affected by a variety of known or unknown confounding factors, which may decrease those points' validity. These points may or may not remain useful for training, depending on how much uncertainty they contain. We submit that in situations where some variability exists in the clarity or confidence associated with individual data points, an approach that takes this confidence into account during the training phase is beneficial. We propose a methodological framework for assigning confidence to individual data records and augmenting training with that information. We test the methodology on two separate datasets, a simulated dataset and a streamflow diel signals dataset. Results indicate that applying and utilising confidence in training improves performance.
SPLAYED, a Novel SWI/SNF ATPase Homolog, Controls Reproductive Development in Arabidopsis

Background: The plant-specific transcriptional activator LEAFY (LFY) is a central regulator of the transition to reproductive development in Arabidopsis. LFY has a second, later role in the induction of floral homeotic gene expression. Available data suggests that, while LFY activity is controlled via interaction with tissue-specific coactivators, other mechanisms exist that regulate LFY activity, the identity of which are not known. Results: We have identified a novel component in the temporal control of the switch from vegetative to reproductive development in Arabidopsis thaliana. The SPLAYED (SYD) gene product acts with LFY to regulate shoot apical meristem identity. SYD is also involved in the regulation of floral homeotic gene expression. In addition, mutations in SYD cause LFY-independent phenotypes that indicate that SYD is necessary for meristem maintenance during reproductive development and that SYD is required for proper carpel and ovule development. SYD encodes a presumptive Arabidopsis homolog of the yeast Snf2p ATPase, which is implicated in transcriptional control via chromatin remodeling. Conclusions: SYD acts as a LFY-dependent repressor of the meristem identity switch in the floral transition, most likely by altering the activity of the LFY transcription factor. That SYD regulates flowering in response to environmental stimuli suggests that the effect of environmental cues on plant development may be achieved in part by regulating transcription factor activity via alteration of the chromatin state.
Tryptophan side chain electrostatic interactions determine edge-to-face vs parallel-displaced tryptophan side chain geometries in the designed β-hairpin trpzip2

The interaction geometries of the four tryptophan (Trp) side chains in the 12-residue designed β-hairpin trpzip2 are investigated using all-atom explicit-solvent molecular dynamics simulations. The experimentally observed edge-to-face (EtF) pairwise interaction geometries are stable on a time scale of 10 ns. However, removing the electrostatic multipoles of the Trp side chains while retaining the dipoles of the side chains' NH moieties induces a conformational change to a geometry in which three of the four side chains interact in a parallel-displaced (PD) manner. Free energy simulations of the Etf to PD conformational change reveal that, with the side chain multipole moments intact (+MP), the EtF conformation is preferred by 5.79 kcal/mol. Conversely, with only the dipole moments of the side chain NH moieties intact (−MP), the PD conformation's free energy is more favorable by 1.71 kcal/mol. In contrast to energetic similarities for Trp side chain−water electrostatic and Trp side chain−Trp side chain and...
Visual Testing: A Viable Instructional Variable.

The primary purpose of this study was to investigate the instructional effects of externally controlled pacing of multiple-choice questions on the achievement of students when tested by means of projected slides. Two 50-item multiple choice criterion measures were developed. Students were evaluated twice during a five-week period. Results of the investigation indicated that: (1) projected-slide tests are as effective as a means of presenting and measuring student achievement as are conventionally printed tests, (b) an item exposure time of 30 seconds is adequate for effective student interaction, (c) two exposures to a multiple-choice test item is no more effective than one exposure, and (d) altering the pacing, item exposure time, or number of times an item is presented, does not significantly affect the reliability of the test. Prior research has concluded that the use of a visual medium to complement conventional classroom instruction, can, in fact, improve student achievement (Gropper, 1962; Twyford et al, 1964; Dwyer, 1972). A majority of these studies were comparative in nature comparing conventional methods of classroom instruction with conventional instruction complemented by media. In these studies media were not utilized as a testing device to evaluate student achievement. The major thrust toward the use of media for testing purposes occurred at the time of World War II when there was a real need to train and test large groups of men in the military service. Additional research studies (Gross, 1969; Hill, 1976; Torrence, 1976) however, have established the feasibility of employing visualized testing to assess student achievement. Specifically, this study was designed to compare student achievement scores on a standard paper-pencil test with the following. 1 The achievement scores of students taking a 50-item multiple choice test on projected-slides with an exposure time consisting of one 30-second viewing of each test item. 2 The achievement scores of students taking a 50-item multiple choice test on projected-slides with an exposure time consisting of two separate viewings. During all viewings students were exposed to each test item for 30 seconds. 3 The achievement scores of students taking a 50-item multiple choice test on projected-slides with an exposure time consisting of one 60-second viewing of each test item. 4 The study also measured the achievement scores of students tested under one set of conditions and tested again under the exact same set of conditions five weeks later on different content relating to the course (internal consistency).
A Measure of Psychological Realism on a Visual Simulator

A FUNDAMENTAL question of simulation technology is how to determine if an aircraft simulation is creating the proper psychological space necessary to assess manned-system performance. The standard approach to this problem for visual simulators is to measure how well pilots can make approaches and landings on the simulator. Experiments of this type generally show that simulator performance is worse than actual landing performance and that there is an excessive amount of training required to reach acceptable performance. Unfortunately, in these experiments it is difficult to sort out the inadequacies of the visual subsystem from possible inadequacies in other simulator subsystems, such as the motion subsystem. This synoptic presents the results from one of a series of five experiments which attempted to provide direct measures of the psychological realism on a computer graphics night visual flight attachment. These experiments used experimental procedures and methodologies that psychologists have developed in their attempts to determine how people perceived visual space in the real world.
Role of adipocytokines in obesity-associated insulin resistance

The rapid increase of obese population in the United States has made obesity into epidemic proportion. Obesity is a strong risk factor for metabolic syndrome, type 2 diabetes mellitus, cardiovascular diseases, cancer and other diseases. Compelling evidence has demonstrated that increased adipose tissue mass is not only the consequence of obesity, but also plays a central role in the development of obesity-associated diseases. Recent studies have profoundly changed the concept of adipose tissue from being an energy depot to an active endocrine organ. The development of obesity alters adipocyte-derived hormones or cytokines expression, which provide a link between obesity and impaired insulin sensitivity and metabolic defects in other tissues. This review summarizes the current knowledge on how major adipose-derived hormones or adipocytokines influence insulin sensitivity.
Specificity proteins Sp1 and Sp3 interact with the rat GTP cyclohydrolase I proximal promoter to regulate transcription.

The role of the proximal promoter GC-box in regulating basal and cAMP-dependent GTP Cyclohydrolase I gene transcription was investigated using a variety of cell lines and techniques. These studies show that the GC-box is composed of a triad of cis-elements that in vitro bind specificity proteins Sp1 and Sp3. Sp1 and Sp3 were found associated with the native proximal promoter in PC12 cells but were not recruited to the promoter during cAMP-dependent transcription. Studies using Drosophila SL2 cells showed that Sp3 occupies two sites within the GC-box and enhances transcription when acting alone and synergistically when combined with nuclear factor-Y (NF-Y) and CCAAT/Enhancer-Binding Protein (C/EBP)β, cognate binding proteins for the adjacent cAMP response element (CRE) and CCAAT-box cAMP response elements. In contrast, Sp1 bound only one site within the GC-box and did not enhance transcription unless combined with NF-Y and C/EBPβ. Studies in SL2 cells also showed that Sp1 and Sp3 do not co-occupy the GC-box, and accordingly Sp1 competes for Sp3 binding to repress Sp3-dependent transcription. In PC12 cells, complete mutation of the GC-box reduced basal but not cAMP-dependent transcription, resulting in an overall increase in the cAMP response and demonstrating that formation of this enhanceosome does not require Sp1 or Sp3. Experiments in which the GC-box was replaced with a Gal4 element and the promoter challenged with Gal4 fusion proteins support this conclusion and a role for Sp3 in maintaining high levels of basal transcription in PC12 cells. Equivalent amounts of Sp1 and Sp3 were found associated with the native proximal promoter in PC12 and Rat2 cells, which differ 10-fold in basal transcription. Similar levels of methylation of CpG dinucleotides located within the GC-box were also observed in these two cells lines. These results suggest that Sp1 and Sp3 bound to the GC-box might help to preserve an open chromatin configuration at the proximal promoter in cells which constitutively express low levels of GTP Cyclohydrolase I.
Kinetic energies of fragment ions produced by dissociative photoionization of NO

The kinetic energies of ions produced by dissociative photoionization of NO have been measured at the discrete resonance lines of He (584A) and Ne (736A), and with undispersed synchrotron radiation. O sup + ions were identified with energies from 0 to approximately 0.5 eV and two groups of N sup + ions one with energy of 0.36 eV and another with energies between 0.9 and 1.5 eV, apparently produced by predissociation of the C sup 3 P 1 and B'1 sigma states respectively.
Hormone Changes Affecting Energy Homeostasis after Metabolic Surgery

Worldwide, there is an epidemic of obesity and its associated diseases. The past decade of research has brought about a paradigm shift in our understanding of both the mechanisms underlying energy homeostasis and the multiple factors contributing to the pathophysiology of obesity. Metabolic surgery is currently far more effective than diet and exercise or pharmacotherapy in achieving durable weight loss. Moreover, the remarkable results of surgery in achieving a rapid remission of type 2 diabetes mellitus has sparked tremendous excitement and research into the mechanisms through which metabolic surgery has its dramatic effect. As opposed to the traditional understanding of “restriction” and “malabsorption,” current evidence suggests that metabolic surgery alters the expression of multiple hormones that affect both short-term and long-term signals of energy balance. We review the hormonal changes following the most common types of metabolic operations currently being performed. The profile of hormonal changes provides a guide to tailor the choice of operation for each individual patient toward achieving the desired metabolic result. In the future, individualized metabolic surgery alone or modulated by targeted pharmacological therapy may achieve the most reliable and effective results with the highest safety and lowest side effect profile. Mt Sinai J Med 77:446–465, © 2010 Mount Sinai School of Medicine
Tem Studies of Cosputtered Tisi 2 Films Containing Excess Silicon.

ABSTRACTThe effect of excess silicon on the growth and microstructure of cosputtered TiSi 2 was investigated. Cosputtered films, with Si/Ti ratios between 2.5 and 4.5, were deposited on (100) Si substrates and reacted at temperatures from 650° to 1050°C. Excess Si in the asdeposited films formed a layer of epitaxial Si on the Si substrate. In addition, Si and SiO2 precipitates formed within the grains. The films became discontinuous when reacted at 1050°C.