cssi/SciSciGPT-SciSciNet huggingface dataset:
Resolution of Methyl Nonactate by Rhodococcus erythropolis under Aerobic and Anaerobic Conditions

An efficient resolution of methyl nonactate is reported by biotransformation in shake flask cultures of Rhodococcus erythropolis. The equilibrium of the reaction redox system can be manipulated by switching from aerobic to anaerobic growth, thereby generating both enantiomers of the target in excellent yield and enantiomeric purity.
Understanding the pH dependence of silicon etching: the importance of dissolved oxygen in buffered HF etchants

Abstract Dissolved O2 is found to have a profound effect on the morphology of Si(1 1 1) surfaces etched in buffered hydrofluoric acid (BHF). Atomically smooth surfaces were exposed to BHF containing varying amounts of dissolved O2 and the resulting changes in etch morphology were measured with scanning tunneling microscopy. These morphological changes were correlated with spectral changes in the infrared absorption spectrum. Surfaces etched in BHF containing dissolved O2 are much rougher than those etched in O2-free BHF. This effect is explained by kinetic competition between O2-induced and etchant-induced oxidation reactions which are followed by rapid etching of the oxidized species. Dissolved O2 alters the net site-specific reactivity of low pH BHF and leads to the production of rougher surfaces. The previously observed pH dependence of Si(1 1 1) etch morphology is also explained by this kinetic competition.
Application and accuracy of the parallel diagonal dominant algorithm

The Parallel Diagonal Dominant (PDD) algorithm is an efficient tridiagonal solver. In this paper, a detailed study of the PDD algorithm is given. First the PDD algorithm is extended to solve periodic tridiagonal systems and its scalability is studied. Then the reduced PDD algorithm, which has a smaller operation count than that of the conventional sequential algorithm for many applications, is proposed. Accuracy analysis is provided for a class of tridiagonal systems, the symmetric and skew-symmetric Toeplitz tridiagonal systems. Implementation results show that the analysis gives a good bound on the relative error, and the PDD and reduced PDD algorithms are good candidates for emerging massively parallel machines.
Anistreplase versus alteplase in acute myocardial infarction: Comparative effects on left ventricular function, morbidity and 1-day coronary artery patency

Objectives. This double-blind, randomized, multicenler trial was designed to compare the effects of treatment with anistreplase (APSAC) and alteplase (rt-PA) on convalescent left ventricular function, morbidity and coronary artery patency at 1 day in patients with acute myocardial infarction. Background. Anistreplase (APSAC) is a new, easily administered thrombolytk agent recently approved for treatment of acute myocardial infarction. Alteplase (rt-PA) is a rapidly acting, relatively fibrin-specific thrombolytic agent that is currently the most widely used agent in the United States. Methods. Study entry requirements were age ≤ 75 years, symptom duration ≤ 4 h, ST segment elevation and no contraindications. The two study drugs, APSAC, 30 U/2 to S min, and rt-PA, 100 mg/3 h, were each given with aspirin (160 mg/day) and intravenous heparin. Prespecified end points were convalescent left ventrkular function (rest/exercise), clinical morbidity and coronary artery patency at 1 day. A total of 325 patients were entered, stratified into groups with anterior (37%) or inferior or other (63%) acute myocardial infarction, randomized to receive APSAC or rt-PA and followed up for 1 month. Results. At entry, patient characteristics in the two groups were balanced. Convalescent ejection fraction at the predischarge study averaged 51.3% in the APSAC group and 54.2% in the rt-PA group (p < 0.05); at 1 month, ejection fraction averaged 50.2% versus 54.8%, respectively (p < 0.61). In contrast, ejection fraction showed similar augmentation with exercise at 1 month after APSAC (+4.3% points) and rt-PA (+4.6% points), and exercise times were comparable. Coronary artery patency at 1 day was high and similar in berth groups (APSAC 89%, rt-PA 86%). Mortality (APSAC 6.2%, rt-PA 7.9%) and the incidence of other serious clinical events, including stroke, ventricular tachycardia, ventricular fibrillation, heart failure within 1 month, recurrent ischemia and reinfarelion were comparable in the two groups; and mechanical interventions were applied with equal frequency. A combined clinical morbidity index was determined and showed a comparable overall outcome for the two treatments. Conclusions. Convalescent rest ejection fraction was high after both therapies but higher after rt-PA; other clinical outcomes, including exercise function, morbidity index, and 1-day coronary artery patency, were favorable and comparable after APSAC and rt-PA.
AN ECONOMIC MODELING APPROACH FOR THE DETERMINATION OF MATERIALITY IN AUDITING

The concept of materiality pervades the audit process. Typically, materiality is determined as a percentage of the total book value of an account or as a percentage of net income. We propose an economically based model that determines that materiality level which minimizes the economic consequences of the audit decision. The proposed model is examined for materiality sensitivity to prior information concerning the quality of the accounting process and to costs incurred as a consequence of the audit decision.
Introduction: Computer-Mediated Collaborative Practices

This special thematic section of the Journal of Computer-Mediated Communication brings together seven articles that consider what it takes to collaborate around and through information and communication technologies. The authors consider how processes co-evolve between practices and technical systems, how knowledge is shared across organizational, cultural and geographic boundaries, how conversation via the informal medium of Instant Messaging is being adopted into organizational practices, what motivates participation in large distributed computing projects, and how computer media can change the nature of interactivity in classrooms. The articles cover a range of applications and settings; as a collection, they draw our attention to the broad interpretation that can be giving to the meaning of collaboration.
Binding of β-Lactam Antibiotics to Penicillin-Binding Proteins in Methicillin-Resistant Staphylococcus aureus

Binding affinity of penicillin-binding proteins (PBP) of Staphylococcus aureus for several beta-lactam antibiotics was examined in a methicillin-susceptible strain and in two methicillin-resistant strains, one heterogeneous and one homogeneous, to determine relationships between PBP binding and expression of resistance. PBPs 1-4 had similar affinities in all three strains. PBP 2a affinities were similar in both resistant strains. For the susceptible strain and for the susceptible subpopulation of cells in the heterogeneous strain, growth inhibition correlated with binding to PBPs 1-3, suggesting that these PBPs mediate susceptibility in both. For resistant cells, growth inhibition correlated only with binding to PBP 2a, suggesting that this is the target in resistant cells. Determination of binding affinity for PBP 2a or the concentration that inhibits growth of the most resistant subpopulation of cells should be included in evaluation of beta-lactam antibiotics for potential activity against methicillin-resistant strains of S. aureus.
Dynamic Scapulohumeral Rhythm: The Effects of External Resistance During Elevation of the Arm in the Scapular Plane

The purpose of this study was to characterize the scapulohumeral rhythm in the normal shoulder during dynamic elevation of the arm in the scapular plane and to compare the scapulohumeral rhythm during three different states of loading: 1) arm completely unloaded and passively elevated, 2) light load consisting of active elevation against the weight of the limb, and 3) heavy loading against maximal resistance. Electromagnetic tracking was used to record three-dimensional scapular and humeral kinematics on 25 normal subjects. Cardan angles were calculated to assess the dynamic relationship of humeral elevation to scapular upward rotation. The results show that during dynamic humeral elevation the scapulohumeral rhythm changes depending on the phase of elevation and the external load on the arm. During passive range of motion, the scapulohumeral rhythm decreased from 7.9:1 to 2.1:1 as the arm was elevated. Light shoulder loads caused an increase of the scapulohumeral rhythm from 3.1:1 to 4.3:1 as the arm was...
Don't interrupt me! Task interruption depletes the self's limited resources

It is a common occurrence in daily life to be interrupted prior to completing a task. Such interruptions may have deleterious effects for limited self-resources, especially if they occur just prior to task completion. This hypothesis was tested in three experiments. In the first two, participants initially engaged in a card sorting task, and then subsequently performed a self-control task. In Experiment 3, participants first engaged in a word search task and then worked on an executive function task. In all instances, participants who were interrupted just prior to attaining their goal of completing the initial task, but not those who were stopped earlier in the task or who were allowed to finish, showed evidence of impairment on the subsequent measures. The findings suggest that the desire to pursue a goal increases as goal attainment draws nearer, and that the amount of self-control needed to stop working on a task is modified by situational variables such as goal distance.
Applied-Information Technology in a Kind of SF6 Gas Density On-Line Monitoring System

The SF6 gas is popular used in high voltage switchgear because it has some advantages such as the electrical disruptive strength or the electric light arc quenching capability. This means that the functional safety of the entire system is strongly depend on the density of SF6 gas which is why it must be monitored. This paper presents a design of the on-line monitoring system of the density of SF6 gas of electronic transformer. The monitoring system, which base on Virtual Instrument, enhances both the flexibility of digital signal processing and the computing speed. On the other hand, the software exploitation, debugging and improving are easier, compared with the hardware circuit. The realization with virtual instrument is flexible and with low fabrication costs and shorten the period.
Immunohistochemical detection of polycyclic aromatic hydrocarbon-DNA damage in human blood vessels of smokers and non-smokers

Abstract The presence of cigarette smoking-related polycyclic aromatic hydrocarbon (PAH)-DNA adducts was investigated in human arterial tissue using an immunoperoxidase staining method with a monoclonal antibody that recognizes benzo(a)pyrene and structurally related PAH diol epoxide-DNA adducts. This is the first time that immunohistochemical methods for detection of PAH-DNA damage have been applied to human endothelial and smooth muscle cells of blood vessels. Internal mammary artery specimens from a total of 37 smokers and non-smokers were tested. Positive nuclear staining was observed in both endothelial and smooth muscle cells, with higher staining in the endothelium. The correlation between smoking status, available for 33 subjects, and detectable PAH-DNA adducts in endothelium did not reach statistical significance (odds ratio=3.38, 95% confidence interval is 0.47–27.60) in this small series. While no causal role can be inferred from our results, they support the theory that endothelial injury caused by cigarette smoking and other environmental exposures may be an early event in the process of atherosclerosis.
The half sky effect: competitive Chinese females

Long considered to be compliant wives and dedicated mothers, Chinese women in this study demonstrate competitiveness equal to that evidenced by Chinese and American males. In a prisoner's dilemma task, Chinese and American males and females are paired cross-culturally and in mixed or same gender pairs. Trust is manipulated across three stages in building, breaking, and repairing trust. Preliminary results suggest that Chinese females were more competitive than American females and as competitive as American and Chinese males.
"Acute myelogenous leukemia like" translocations in CML blast crisis: two new cases of inv(16)/t(16;16) and a review of the literature.

Abstract We describe two patients with CML blast crisis with clonal evolution affecting 16q22 (t(16;16)(p13;q22) and inv(16)(p13;q22), abnormalities of core binding factor, usually found in de novo acute myeloid leukemia (AML)). The bone marrow of both cases showed myelomonocytic (M4) differentiation and eosinophilia. Both patients had prominent extramedullary disease and had poor response to treatment. A literature search focused on patients with CML and additional chromosome changes more typical of AML, revealed that the morphology of the blasts correlated with the finding typical of the underlying “AML” cytogenetic abnormality and an overall very poor clinical outcome, even in the groups with “favorable” AML type translocations.
Fusiform aneurysms of the lenticulostriate artery

Lenticulostriate artery aneurysms are rare, can be difficult to diagnoze, and when they rupture they are often associated with deep intraparenchymal hemorrhages. In particular, fusiform, dissecting aneurysms of a distal lenticulostriate artery are extremely rare. Typically, they are usually associated with underlying systemic conditions such as systemic lupus erythematosus, moyamoya disease, and substance abuse. Given their usual small size and location, these aneurysms may be difficult to detect with angiography and can be challenging to treat with either endovascular or microsurgical techniques. We provide background information, review the existing treatment experiences reported in the literature, and present a discussion regarding the optimal management using an illustrative clinical vignette. Parent artery obliteration can be a safe and effective treatment in these rare aneurysms.
Monoclonal antibodies used in the detection and treatment of epithelial ovarian cancer

Conventional therapy for epithelial ovarian cancer, including aggressive cytoreductive surgery followed by combination chemotherapy regimens, has failed to reduce the number of deaths caused by this disease, which remains the most lethal of gynecologic malignancies. Monoclonal antibodies, which offer the promise of high selectivity for detection and therapy, may be targeted to tumor-associated antigens, growth factors, receptors, or oncogenes. They may be used alone as immunotherapeutic agents or conjugated to chemotherapeutic drugs, toxins, or radionuclides. Radioimmunoconjugates may also be used for preoperative or intraoperative tumor localization. The authors focused on the clinical utility, technical limitations, and potential of monoclonal antibodies in the detection and treatment of epithelial ovarian cancer with emphasis on radioimmunodetection and radioimmunotherapy.
The ultrastructure of the principal cells and intraepithelial leucocytes in the initial segment of the rat epididymis.

The ultrastructure of the principal cells and intraepithelial leucocytes in the initial segment of the rat caput epididymidis was examined with the electron microscope. Specializations of the principal cells associated with absorption include numerous endocytic invaginations of the cell surface, numerous coated vesicles and multivesicular bodies in the apical cytoplasm. It was demonstrated that particulate tracers are taken into the cells and sequestered in secondary lysosomes and multivesicular bodies. Morphological features consistent with secretory activity are also found in the principal cells and include numerous cisternae of rough endoplasmic reticulum with a flocculent grey content and an extremely well-developed Golgi apparatus. The speculation that the principal cells are actively secretory despite the absence of secretory granules formed in the Golgi and of a visible mechanism for release of the product at the cell surface is discussed. The “halo cells” in the epididymal epithelium were also examined and it is shown that many of these cells are not typical migratory lymphocytes. Chief among the differences are their granule-containing multivesicular bodies and more abundant endoplasmic reticulum. Nonetheless, it is conceivable that the halo cells are lymphocytes and that the conditions they encounter as they leave the circulation and enter the epididymal epithelium may stimulate morphological changes. The possible immunological significance of these observations is discussed.
Stereospecificity of Retinol Saturase: Absolute Configuration, Synthesis, and Biological Evaluation of Dihydroretinoids

Retinol saturase carries out a stereospecific saturation of the C13−C14 double bond of all-trans-retinol to generate (13R)-all-trans-13,14-dihydroretinol. This compound is found in cells expressing mouse or zebrafish retinol saturase and in the livers of mice fed retinyl palmitate. All-trans-13,14-dihydroretinol is oxidized in vivo to all-trans-13,14-dihydroretinoic acid, a highly selective agonist of the retinoic acid receptor. The naturally occurring (13R)-all-trans-13,14-dihydroretinoic acid is a weaker agonist than the (13S) enantiomer, indicating enantioselective recognition by the ligand-binding pocket of this receptor. Consequently the (13S) enantiomer, acting through the retinoic acid receptor, also inhibits adipose differentiation more potently than the (13R) enantiomer.
Teaching about the aesthetics of biology: A case study on rhythm

This article is an investigation of the role the aesthetic plays in biological inquiry and in the appreciation of the concepts of biology. A case-study approach is used focussing on the role of rhythm in biological process and in aesthetic experience. The purpose of this examination is to provide teachers with background in the aesthetics of biology so that they are better able to include the aesthetic aspects of this science in their teaching.
Sequence-specific binding of HMG-I(Y) to the proximal promoter of the gp91-phox gene.

Abstract Screening of a cDNA expression library with a CCAAT-box element derived from the myelomonocyte-specific gp91-phox promoter resulted in the isolation of three independent HMG-I(Y) cDNA clones. Filter binding competition studies reveal that HMG-Y binds to this promoter element in a sequence-specific manner and exhibits a gradient of binding affinities for various A T -rich sequences. Two adjacent A T -rich regions within the gp91-phox promoter CCAAT-box element are required for maximal binding. In addition, competition experiments demonstrate that the binding affinity of HMG-Y is influenced by sequences that flank A T -rich core binding sites.
Experience in monitoring domestic water sources and process waters for trace organics

Synopsis A strategy for monitoring municipal drinking water sources, process waters, and distribution waters for the presence of selected organic compounds, both volatile and non‐volatile, is described. The monitoring strategy and associated analytical procedures evolved in conjunction with organic monitoring investigations completed by the author for several cities in Indiana and Kentucky. The need, basis, strengths and limitations of the organic monitoring (screening) approach is described. A brief description is also given for the gas Chromatographie methods which were used to measure the presence of volatile and non‐volatile “indicator”; organic compounds. Water utility officials initiating a testing program for organic contaminants may benefit from the experience described herein.
Analysing disequilibrium interest-rate systems in developing countries

Abstract Under equilibrium conditions, monetary policy measures to raise institutional interest rates are contractionary. When interest rates are held below their free-market equilibrium levels, however, an increase can be expansionary. Higher institutional interest rates may deter savings in the form of unproductive inflation hedges and encourage savings in the form of financial claims issued to finance productive investment. In most developing countries, money is the predominant financial repository of savings and bank loans are a major source of investible funds. Hence, attention is focused here on models which analyse the effects of binding interest-rate ceilings on financial intermediation. Empirical evidence reported in this paper is consistent with the view that binding institutional interest-rate ceilings can have a substantial growth-reducing impact.
Cancer-testis antigen expression and immunogenicity in AL amyloidosis

Light-chain amyloidosis (AL) is a plasma cell dyscrasia closely related to multiple myeloma. In multiple myeloma, the cancer-testis antigens (CTAs) CT7 (MAGE-C1), CT10 (MAGE-C2) and MAGE-A CTAs are expressed in up to 80% of cases. In this study, we investigated the expression and immunogenicity of several CTAs in patients with AL amyloidosis in a total of 38 bone marrow specimens by employing standard immunohistochemistry techniques on paraffin-embedded archival tissues. Plasma samples from 35 patients (27 with matched bone marrow samples) were also analyzed by ELISA for sero reactivity to a group of full-length CTA proteins. CT7 was present in 25/38 (66%) while CT10 was demonstrated in 3/38 and GAGE in 1/38 AL amyloid cases. The expression pattern was mostly focal. There were no significant differences with regard to organ involvement, response to treatment, or prognosis in CTA positive compared to negative cases. None of the specimens showed spontaneous humoral immunity to CT7, but sero reactivity was observed in individual patients to other CTAs. This study identifies CT7 as the prevalent CTA in plasma cells of patients with AL amyloidosis. Further analyses determining the biology of CTAs in AL amyloidosis and their value as potential targets for immunotherapy are warranted.
Nonlinear scaling analysis of glucose metabolism in normal and cancer cells

Cancer progression is commonly accompanied by an altered glucose metabolism. In general, spatially resolved imaging of glucose metabolism and its subtle alterations might provide valuable diagnostic information in vivo. A classical example is positron emission tomography that exploits this feature in obtaining preferential accumulation of fluorescent analog of glucose in tumors, thereby achieving an imaging contrast. We report a novel scaling analysis of glucose metabolism in mammary epithelial (NMuMG) cells by detrended fluctuation analysis of Cerulean (cyan fluorescent protein variant) fluorescence. Fluorescence fluctuations of Cerulean are reasoned to be indicative of dynamic pH changes associated with glucose metabolism. Normal parental cells and the spontaneously transformed (cancerous) NMuMG cells displayed robust scaling exponent that reflects nonrandom fluctuations in Cerulean fluorescence. Acute dependence of cancer cells on glycolysis as compared with normal cells is exploited to yield a statistically significant difference in scaling exponent, thereby providing discrimination between normal and cancer cells in vitro. By careful design of experiments in vivo, the proposed scaling approach might even have diagnostic potential for early detection of cancer lesions in small animal models.
Feast and famine

A staple food is defined as a main element of a diet. It is determined by the climate, the level of technical development, the culture and social conditions of the country. How does the role of staple foods compare in such dissimilar countries as the United Kingdom and Uganda?
NMR-based stable isotope resolved metabolomics in systems biochemistry

An important goal of metabolomics is to characterize the changes in metabolic networks in cells or various tissues of an organism in response to external perturbations or pathologies. The profiling of metabolites and their steady state concentrations does not directly provide information regarding the architecture and fluxes through metabolic networks. This requires tracer approaches. NMR is especially powerful as it can be used not only to identify and quantify metabolites in an unfractionated mixture such as biofluids or crude cell/tissue extracts, but also determine the positional isotopomer distributions of metabolites derived from a precursor enriched in stable isotopes such as 13C and 15N via metabolic transformations. In this article we demonstrate the application of a variety of 2-D NMR editing experiments to define the positional isotopomers of compounds present in polar and non-polar extracts of human lung cancer cells grown in either [U–13C]-glucose or [U–13C,15N]-glutamine as source tracers. The information provided by such experiments enabled unambiguous reconstruction of metabolic pathways, which is the foundation for further metabolic flux modeling.
Ischemia of postmastectomy skin after infiltration of local anesthetic with epinephrine: a case report and review of the literature

The goals of this study were to review the literature regarding the use of local anesthetic with epinephrine and to report an observation of prolonged ischemia and necrosis in postmastectomy skin. A PubMed literature review was performed and the patient’s medical record was reviewed. Prior skin necrosis with epinephrine use in acral areas was often due to physician or manufacturing overdose. Many large studies have confirmed subsequently epinephrine’s safety in acral areas. There are reports of prolonged ischemia in the dermatology literature when used in areas with impaired venous and lymphatic drainage. Our case report suggests that the impaired clearance mechanisms in postmastectomy skin with an underlying implant can lead to ischemia when using local anesthetic with epinephrine. The addition of epinephrine to local anesthetic increases the duration of analgesia and provides for a relatively bloodless operating field. In the past many surgeons were reluctant to use it because of concerns about arterial vasospasm and tissue necrosis. However, perceptions have recently changed as large reviews have documented its safe use in acral areas. Based on our review of the literature and this case, epinephrine use may not be appropriate in patients with compromised venous and lymphatic drainage.
A microprogram simulator and compiler for an enhanced version of Tanenbaum's MIC-1 machine

One of the objectives of a course in computer organization is to show how the machine language of a computer (with which students are already familiar through an assembly language course) is actually implemented. This is normally accomplished by first gaining familiarity with digital logic (gates, flip-flops, registers, multiplexer, etc.) and then proceeding to design a simple machine. The last stage of this design process is to design the control unit, either by hardwired control or microprogramming. Thus, microprogramming is a central topic in the study of computer organization, tying together the study of digital logic with the implementation of the machine language of a computer. It follows that laboratory experience in microprogramming should be an important part of the computer organization course. In most cases, however, access to microprogrammable hardware is not available. Although some instructors have utilized commercially available microprogrammable processors [1] or actually built microprogrammable hardware for classroom use [2], the most common approach has been to rely on software simulation of hardware at the microprogramming level [3-12]. The simulation approach allows students to carry out a variety of exercises involving the implementation of a conventional machine language. The most popular target architecture for classroom simulators has been the Mic-1 machine described in the Computer Organization text of Tanenbaum [13]. The Mic-1 is a microprogrammable architecture which Tanenbaum uses to implement a simple machine instruction set for a single-accumulator machine called the Mac1.
Calculation of Velocity in Three Space Dimensions from Hydraulic Head Measurements

This paper describes a systematic and straightforward method for the estimation of velocity components in three dimensions from hydraulic head data. Groups of four measurement points are connected to form tetrahedrons, and a linear interpolation scheme is used to obtain a head gradient estimate for each tetrahedron. Application of Darcy's law then yields the desired velocity component values. A sample calculation and comparison between this method and a two-dimensional approach are also included.
Cost of locomotion of a dynamic hexapedal robot

In this work we analyze the cost of transport of in-plane hexapedal robots. The robots are modeled as a rigid body with six massless legs, each having two compliant degrees of freedom and the contact is modeled using Coulomb's model. We start our analysis by formulating the cost of transport for rigid legged robots as a function of their geometry, friction coefficients, actuation velocities and slope angle and compare it to the results of a dynamic multibody numeric simulation. In the second part, we estimate the cost of transport in the more general case when the legs and surface are compliant. We evaluate the energy consumptions factors, sliding, work against gravity, elastic losses of the legs and the surface, and kinetic energy and compare them to the total energy input of the actuators. This analysis allows us to evaluate the work range of the robots and determine the optimum locomotion paths for improved battery performance.
Electrolocation in the presence of jamming signals: behavior

Electrolocation behavior of Apteronotus leptorhynchus was studied by monitoring the animal's ability to maintain orientation to a variety of moving electrolocation targets. The primary goal of this study was to determine the relative effectiveness of various types of electrical 'jamming signals' in disrupting electrolocation performance. 1. Two measures of electrolocation performance were used: The latency between the electrolocation target motion and the fish's following response, and the minimum distance separating the fish from the target during the target movement sequence. Latency increased and minimum fish-target distance decreased as target size was decreased, and when large diameter ceramic targets were used as control stimuli the fish were less able to avoid, and frequently collided with, these 'electrically transparent' objects. 2. Four types of jamming signals were used in attempts to mask the electrosensory input used for electrolocation. Broad-band noise and sinusoidal signals, different in frequency by a few Hz from the animal's personal electric organ discharge (DF stimuli), were used to jam the tuberous electroreceptors. Five Hz and 50 Hz sinusoidal signals were used to jam the low-frequency or ampullary receptor system. Both the noise and the DF stimuli were effective in reducing electrolocation performance, and the threshold intensity for behavior deterioration was about three-fold lower for DF stimuli as compared to the noise. The rate of change of response deterioration as a function of increasing jamming intensity was, however, not different for these two types of stimuli. Neither the 50 Hz nor the 5 Hz jamming signals caused electrolocation deterioration when presented alone. However, 5 Hz jamming, when added to either the noise or DF jamming, did result in significant increments in response deterioration. This suggests that the ampullary receptors can provide supplementary information for electrolocation. 3. Electrolocation performance deterioration was also studied with various difference frequencies between an animal's EOD and the sinusoidal jamming stimulus. Increasing DF results in decreased electrolocation deterioration, but even at the highest DF frequencies used (128 Hz) significant response degradation was observed. 4. The apparent differences in the effectiveness of noise and DF stimulation in reducing electrolocation performance are largely accounted for by the differential effects of the tuberous electroreceptor filter characteristics on these two types of signals.
The location problem for color subjectivism.

According to color subjectivism, colors are mental properties, processes, or events of visual experiences of color. I first lay out an argument for subjectivism founded on claims from visual science and show that it also relies on a philosophical assumption. I then argue that subjectivism is untenable because this view cannot provide a plausible account of color perception. I describe three versions of subjectivism, each of which combines subjectivism with a theory of perception, namely sense datum theory, adverbialism, and the virtual color proposal, and argue that each version faces serious objections. Considering these three theories of perception to be exhaustive of those available to the subjectivist, I conclude that subjectivism is untenable and that the scientifically motivated argument for this view is unsound. I then offer the diagnosis that the philosophical assumption on which this argument relies is mistaken.
Taking stock, moving forward: the Internet, social networks and civic engagement in Chinese societies

The Internet in China reflects many contradictions and complexities of the society in which it is embedded. Despite the growing significance of digital media and technologies, research on their contingent, nonlinear, and sometimes paradoxical impact on Chinese citizens' civic engagement remains theoretically underdeveloped and empirically understudied. As importantly, many studies on the Internet implications in the Chinese societies have centered on China. This essay introduces seven articles that draw on a variety of theoretical and methodological approaches to advance a balanced and context-rich understanding of the implications of digital media and technologies in China, Taiwan, and the global Chinese diaspora. It further discusses venues for future research, especially studies that take into account the evolving Chinese media landscape and the rise of the mobile Internet, civic and political participation across multiple platforms and their interactions, as well as organizational and interpersonal ne...
Concreteness of Depressive Rumination and Trauma Recall in Individuals with Elevated Trait Rumination and/or Posttraumatic Stress Symptoms

The present study sought to compare the cognitive characteristics of depressive rumination and trauma recall in participants with high trait rumination and/or high levels of posttraumatic stress symptoms (PTSS), as well as in participants with normative levels of these variables. Specifically, we sought to compare the degree to which periods of depressive rumination and trauma recall were characterized by verbal-linguistic versus imagery-based activity and abstract versus concrete thought. We also explored whether these characteristics differed between participants with high trait rumination and/or high levels of PTSS, as well as participants with normative levels of trait rumination and PTSS. We found that for all participants, depressive rumination was characterized by increased verbal-linguistic activity, whereas trauma recall was characterized by increased imagery-based activity. We also found that individuals with both high trait rumination and high levels of PTSS evidenced lower levels of imagery-based activity during all repetitive thinking periods, as well as lower levels of concreteness during depressive rumination. Theoretical and clinical implications of these findings are discussed.
A molecular phylogeny of the New World orioles (Icterus): the importance of dense taxon sampling.

We sequenced 2005 bp of the mitochondrial ND2 and cytochrome b genes from the 25 recognized species of New World orioles (Icterus). Our data confirmed the monophyly of Icterus and produced a well-resolved phylogeny showing three main clades of orioles. We also sequenced multiple subspecies for most polytypic taxa. Our findings demonstrated the importance of dense taxon sampling below the species level in two ways. First, we found evidence that two species are polyphyletic, I. galbula (Northern oriole) and I. dominicensis (Black-cowled oriole). Choosing different subspecies from either of these taxa would lead to different species-level phylogenies. Second, adding subspecies even to monophyletic groups produced a bootstrap tree with significantly more support. Of the two genes that we used, ND2 provided more resolution than did cytochrome b. ND2 evolved up to 40% faster than cytochrome b, yet shows a higher saturation threshold. Our findings suggest that ND2 may be superior to cytochrome b for resolving species-level phylogenies in passerine birds.
Parallel Implementation of Boltzmann Transport Simulation of Carbon Nanotubes

This works treats electronic transport in SWNTs in the Boltzmann Transport equation (BTE) formalism. The BTE is solved self-consistently with the Poisson equation and iterated in time using an upwinding finite-difference scheme until a steady-state is reached. Phonon scattering is included through a relaxation time based on experimental values reported in the literature. The problem is parallelized by dividing the real space into strips, where each strip is assigned to one processing element to minimize communication overhead. The implementation was tested on a many-processor cluster and shows good speed-up over the serial code. This demonstrates that the code is capable of excellent scaling to large supercomputing machines for large-scale parallel simulation of nanotubes, as well as other similar 1-dimensional materials like nanoribbons and nanowires.
A Participant-Informed Model for Preventing Teen Pregnancy in a Rural Latino Community

Recognizing the need for health prevention efforts that are tailored to the needs of Latinos in rural communities, the researchers utilized focus groups to ascertain the perspectives of Latino children and their parents who participated in a teen pregnancy prevention program. This article presents a Latino-driven conceptual design of an evidence-informed comprehensive, community-based, and culturally sensitive teen-pregnancy prevention program. The new model, called the Family-Festival Prevention Model, (1) used culturally relevant and experiential learning activities, (2) promoted community connections, (3) incorporated strategies that engaged fathers, and (4) engaged important faith-based and community stakeholders to involve the whole community in prevention efforts.
Quantitative measurements of capillary transport in human brain tumors by computed tomography.

The rate at which water-soluble chemotherapeutic drugs enter brain tumors can be extremely variable. The ability to measure or predict the rate of drug entry may have an important role in treatment. We have developed a method that uses information from contrast-enhanced computed tomographic scans to measure quantitatively the rate of transcapillary transport of iodinated compounds in brain tumors. In a group of 10 patients with brain tumors, we obtained serial measurements of tissue (Am) and arterial plasma (Cp) iodine concentration from timed computed tomographic scans done over 30 minutes, after intravenous infusion of meglumine iothalamate (Conray-60). These measurements were analyzed with a two-compartment pharmacokinetic model and nonlinear least-squares regression methods to obtain K1, a blood-to-tissue transfer constant; k2, a tissue-to-blood rate constant; and Vp, tissue plasma vascular volume. Images of K1, k2, and Vp were reconstructed after calculating these values for each 0.8 × 0.8 × 5-mm volume element of the original data. Mean whole tumor K1 values varied from 2.0 μl gm−1 min−1 in a thalamic astrocytoma to 33.9 μ1 gm−1 min−1 in a glioblastoma multiforme. The value of k2 varied from 0.034 to 0.108 min−1, and Vp varied from 2.4 to 7.9 ml 100 gm−1. In tumor-free brain, the K1 of meglumine iothalamate was 2.9 μ1 gm−1 min−1; k2 was 0.058 min−1; and Vp was 2.1 ml 100 gm−1. There was pronounced variability in transcapillary transport values between different malignant brain tumors, as well as regional variability within individual tumors, with focal increases in K1 up to 50-fold normal brain values. This approach provides a quantitative method to measure the rate of transcapillary transport of passively distributed iodinated compounds in human brain tumors. These types of measurements can be used to study serial changes of capillary permeability in individual patients that occur as a result of therapeutic manipulation and may, potentially, be used to individualize chemotherapy.
Using Web-Based Foreign Advertisements in International Marketing Classes

The author examines the use of the Web-based foreign advertisements for enhancing the international awareness of undergraduate marketing students. An analysis compares the adaptation of advertisements for identical products to the cultural perceptions and values of consumers in different countries. In a sample of 110 international marketing students, 41% rated the analysis of foreign advertisements as “useful” and 41% “highly useful”; 71% of students observed highly significant differences between foreign and domestic advertisements, 29% perceived moderate differences.
Estrogen inhibits hypothalamic pro-opiomelanocortin gene expression in hypothalamic neuronal cultures

Abstract Many in vitro studies show estrogen regulation of the hypothalamic pro-opiomelanocortin (POMC) system, including a decrease in hypothalamic POMC mRNA after estradiol treatment. Because such in vivo experiments do not allow one to determine whether peripheral, interacting systems or extra-hypothalamic brain regions are involved in this regulation, we sought to establish whether estrogen acts directly in hypothalamus to decrease POMC mRNA. Using an in vitro approach, we studied effects of estradiol (E 2 ) on POMC/cyclophilin mRNA concentrations (RNAse protection assays) in neuronal cultures derived from day 17 fetal rat hypothalamus. Chemically defined medium was deprived of progesterone for 2 days prior to E 2 treatment and for the duration of the study. E 2 (10 −13 –10 −9 M) dose-dependently decreased POMC mRNA concentrations during a 2-day treatment. Whereas the lowest dose (10 −13 M) of E 2 resulted in a statistically significant 44% decrease in POMC mRNA concentrations relative to control cultures, this inhibitory effect was lost because higher doses (10 −11 and 10 −9 M) did not produce statistically significant decrements (22 and 16%, respectively) in POMC mRNA concentrations. Additional time course studies revealed that this decrease in POMC mRNA can be seen as early as 4 h after E 2 (10 −13 M) treatment. We conclude that E 2 inhibition of POMC mRNA concentrations in hypothalamic neuronal cultures indicates that this inhibition can occur directly in hypothalamus. © 1997 Elsevier Science B.V. All rights reserved.
LCVR-based polarimetry: calibration issues

Changes in the structural organization of biological tissue can be indicative of disease. The ability to measure and associate changes in structural organization with disease-related cellular architecture has significant diagnostic value. Here we present a spectral imaging polarimeter to probe the local structural organization of tissue. The system is based on liquid crystal technology, and is comprised of two modules, a Stokes generator and a polarimeter. The Stokes generator uses a pair of Liquid Crystal Variable Retarders (LCVRs) to generate a set of Stokes vectors incident on a sample, while the polarimeter utilizes a separate pair of LCVRs to analyze the scattered Stokes vectors. Characterization of the system is in terms of a data reduction matrix that relates the polarimeter measurements to the incident Stokes vector. Calibration of the polarimeter (calculation of the elements of this data reduction matrix) is performed by presenting a series of known Stokes vectors to the device. The resulting over-determined system of equations is solved using the Singular Value Decomposition. We discuss the construction and calibration of the system.
Homocysteine prevents apomorphine-induced decreases in dopamine metabolites.

Abstract Low doses of apomorphine reduced dopamine (DA) metabolite concentrations in mouse and rat striata. These reductions were prevented by pretreatment with homocysteine at a dosage which had been shown to inhibit protein car☐yl and other methylation reaction in brain. By itself, homocysteine did not alter DA metabolite concentrations. These findings are discussed with regard to the possible role of cerebral methylation reactions in mediating DA autoreceptor functions.
The Simplest Axiom System for Plane Hyperbolic Geometry

We provide a quantifier-free axiom system for plane hyperbolic geometry in a language containing only absolute geometrically meaningful ternary operations (in the sense that they have the same interpretation in Euclidean geometry as well). Each axiom contains at most 4 variables. It is known that there is no axiom system for plane hyperbolic consisting of only prenex 3-variable axioms. Changing one of the axioms, one obtains an axiom system for plane Euclidean geometry, expressed in the same language, all of whose axioms are also at most 4-variable universal sentences. We also provide an axiom system for plane hyperbolic geometry in Tarski's language L B≡ which might be the simplest possible one in that language.
Improvements to the quantitative assay of nonrefractory minerals for Fe(II) and total Fe using 1,10-phenanthroline

Abstraet--A method using 1,10-phenanthroline (phen) to quantify Fe(II) and total Fe in nonrefractory minerals was modified to improve the accuracy and precision and to eliminate the inconvenience of performing much of the analysis under darkroom conditions. Reagents were combined to minimize solution-handling errors, volumes of the reagent additions were determined gravimetrically and the acidmatrix solution was preheated to near-boiling before sample contact. The darkness requirement, which stems from the photoreduction of Fe(III) to Fe(II) in the presence of phen, was eliminated by the use of opaque amber-colored high-density-polyethylene bottles during the digestion step and for storage of the digestate and subsequent dilutions before Fe(II) analysis. Reduction of Fe(III) for total-Fe analysis was accomplished either by exposure to light from a Hg-vapor lamp or by reaction with hydroxylamine, NH2OH. Although the minimum periods required for adequate reduction ranged from 1.5 to 4 h, the optimum reduction periods were between 6 and 10 h. When standard samples containing Fe(II) and MnC12 were digested and analyzed for total-Fe using the light treatment (with incidental heating to 35-45 ~ significant decreases and in some instances, oscillations, in absorptivity were obtained. Similar experiments with NH2OH, or with CrC13 showed no effect. The absorptivity of most digestates stored in opaque bottles was stable for at least 2 weeks, although digestates with Mn concentrations above 3 ~g mL showed proportional decreases in absorptivity. Analysis of 8 geochemical reference materials by the modified method (using NH2OH) yielded excellent agreement with published values and a mean relative standard deviation of 0.6%. Total-Fe results obtained using the light treatment, however, were generally lower (-2% relative) than the NH2OH values, although this difference decreased with longer irradiation periods. Use of NH2OH was deemed preferable because it was simpler, faster, minimized interferences from Mn and eliminated the need for specialized apparatus. Lastly, MICA Fe was shown to be unreliable as a primary reference material for Fe(II) determinations.