cssi/SciSciGPT-SciSciNet huggingface dataset:
Testing On Computers

Russell and Haney (1997) reported that open-ended test items administered on paper may underestimate the achievement of students accustomed to writing on computers. This study builds on Russell and Haney's work by examining the effect of taking open-ended tests on computers and on paper for students with different levels of computer skill. Using items from the Massachusetts Comprehensive Assessment System (MCAS) and the National Assessment of Educational Progress (NAEP), this study focuses on language arts, science and math tests administered to eighth grade students. In addition, information on students' prior computer use and keyboarding speed was collected. Unlike the previous study that found large effects for open-ended writing and science items, this study reports mixed results. For the science test, performance on computers had a positive group effect. For the two language arts tests, an overall group effect was not found. However, for students whose keyboarding speed is at least 0.5 or one-half of a standard deviation above the mean, performing the language arts test on computer had a moderate positive effect. Conversely, for students whose keyboarding speed was 0.5 standard deviations below the mean, performing the tests on computer had a substantial negative effect. For the math test, performing the test on computer had an overall negative effect, but this effect became less pronounced as keyboarding speed increased. Implications are discussed in terms of testing policies and future research.
Calcium-dependent control of temporal processing in an auditory interneuron: a computational analysis.

Sensitivity to acoustic amplitude modulation in crickets differs between species and depends on carrier frequency (e.g., calling song vs. bat-ultrasound bands). Using computational tools, we explore how Ca2+-dependent mechanisms underlying selective attention can contribute to such differences in amplitude modulation sensitivity. For omega neuron 1 (ON1), selective attention is mediated by Ca2+-dependent feedback: [Ca2+]internal increases with excitation, activating a Ca2+-dependent after-hyperpolarizing current. We propose that Ca2+ removal rate and the size of the after-hyperpolarizing current can determine ON1’s temporal modulation transfer function (TMTF). This is tested using a conductance-based simulation calibrated to responses in vivo. The model shows that parameter values that simulate responses to single pulses are sufficient in simulating responses to modulated stimuli: no special modulation-sensitive mechanisms are necessary, as high and low-pass portions of the TMTF are due to Ca2+-dependent spike frequency adaptation and post-synaptic potential depression, respectively. Furthermore, variance in the two biophysical parameters is sufficient to produce TMTFs of varying bandwidth, shifting amplitude modulation sensitivity like that in different species and in response to different carrier frequencies. Thus, the hypothesis that the size of after-hyperpolarizing current and the rate of Ca2+ removal can affect amplitude modulation sensitivity is computationally validated.
Detection and identification of biological materials through their optical activity using the Mueller matrix

The study of the interaction of polarized light with biological materials such as human tissue has applications in medical diagnosis and medicine. Polarized light that is reflected or transmitted through biological specimens can also be used to detect and identify biological and chemical threat agents. The determination of the silent foot prints of the chiral properties of the biological materials on scattered polarized light, is the basis for these investigations. The polarization states of electromagnetic waves which in general are elliptical, are represented by its Stokes vector. Scattered light is completely characterized by the 4 x 4 Mueller matrix that relates the scattered Stokes vector to the incident Stokes vector. It is of primary importance to identify which of the sixteen elements of the Mueller matrix for reflected and for transmitted light are most sensitive to the chiral properties of the biological materials. The explicit analytical dependence of these specific elements of the Mueller matrix, upon the angles of incidence and scatter, upon the wavelength and upon the type of chirality has the potential to provide experimentalists with guidance in determining the optimum use of optical polarimetric scatterometers to detect and identify biological materials through their chiral properties.
Aversive cigarette smoking as a smoking cessation procedure.

Aversive cigarette smoking that consisted of rapid smoking, warm smoky air, and handling of cigarette litter was investigated. Prior to treatment, all Ss were screened to minimize risks inherent in rapid smoking. Three male and 9 female Ss completed 6 weeks of treatment. After treatment the mean smoking rate was 16% of baseline. At 3-, 6-, and 9-month follow-ups, the mean average was 38%, 50% and 50% of baseline, respectively. Aversive smoking appears to be a promising behavioral approach to smoking cessation.
Effects of prolonged exposure of Oryzopsis hymenoides to SO2

Oryzopsis hymenoides, a desert grass, was exposed to low concentrationsof SO2 ranging from 0.03 to 1.00 ppm for six week fumigation periods. Deleterious effects were noted only at atmospheric SO2 concentrations of 0.13 ppm and above. These effects included necrotic lesions and reduced net primary productivity. At concentrations below 0.13 ppm, the SO2 appeared to have a beneficial effect on productivity. The deleterious effects noted at the higher concentrations have ecological implications if pollutant sources are located in desert environments.
Erythromycin resistance in mouse L cells.

The sensitivity of mouse cell lines in culture to the macrolide antibiotic, erythromycin stearate, was investigated. Both resistant and sensitive lines were found. Experiments indicated that in sensitive cells erythromycin stearate inhibits mitochondrial protein synthesis. Mutants resistant to erythromycin stearate were selected from the line LM(TK−), and these are also less sensitive to other macrolide antibiotics such as carbomycin and spiramycin. Attempts to transfer the erythromycin resistance of either the mutants or naturally resistant lines by fusion of cytoplasts with sensitive cells were unsuccessful, and it is concluded that resistance to erythromycin stearate is controlled by nuclear genetic factors.
An analysis of alcoholics' perception of hostility before and after treatment

Volunteer alcoholics being treated in a chemical dependency unit (CDU) were administered the Paired Hands Test-Adult to assess their perceptions of others before and after three weeks of treatment. This test assessed the perception of others along a friendliness-hostility dimension. Test data were compared to a non-alcoholic control group who were not receiving any form of therapeutic services. The main hypothesis tested was that alcoholics experience more hostility than non-alcoholics and project this hostility through perceptual defenses. A secondary hypothesis tested was that traditional short-term therapy reduces the alcoholic's perception of hostility. Neither hypothesis was supported.
Prediction of functional engrailed homology-1 protein motif from sequence

Prediction of functional peptide motifs from sequences is an important problem in bioinformatics. Experimental discovery of functional sequences is laborious. Searches for specific motifs within the increasing number of proteins available in public databases often involve extensive computer calculations. Short peptide motifs are especially hard to identify via currently available methods. Presented here is a simple and effective procedure to identify a short functional motif. The procedure is based on devising a scoring function using sequence properties. The procedure was applied on short engrailed homology-1 (eh1)-like motif. Eh1-like motif provides repressive functions by binding to the WD domain of the Gro/TLE transcriptional corepressors. Interactions of known eh1-like variants and the WD domain were modeled and studied. Sequence features crucial for the interactions, and thus the motif's functionality, were identified. A scoring function was devised based on the observed sequence features. The ability of the scoring function to discriminate between functional and nonfunctional sequences was tested on known eh1-like sequences, random sequences, and eh1-like sequences predicted by others using various bioinformatics tools. The scoring function expressed well a general relationship between sequences and their functionalities. It gave about 20% false positive findings. However, the scoring function reliably identified sequences that were not functional eh1-like motif. The procedure presented here may prove useful for predicting functional sequences of other short motifs. Given the importance of transcriptional regulation, this study on identification and evaluation of functional eh1-like sequences should facilitate further research on their transcriptional roles.
Scope of the Two-Step, One-Pot Palladium-Catalyzed Borylation/Suzuki Cross-Coupling Reaction Utilizing Bis-Boronic Acid

The use of bis-boronic acid for the direct synthesis of boronic acids has greatly facilitated the two-step, one-pot borylation/Suzuki cross-coupling reaction between aryl and heteroaryl halides. With use of Buchwald’s second-generation XPhos preformed catalyst, high yields of cross-coupled products were obtained for most substrates. The method also allows an efficient two-step, one-pot synthesis, providing access to three distinct cross-coupled products after column chromatography. The method also provides a rapid and convenient route to teraryl compounds.
Indocyanine Green Dye Enhanced Vascular Welding With the Near Infrared Diode Laser

For vascular anastomosis, use of topical photosensitizing dye enhances selec tive delivery of laser energy to target tissue, thus reducing the amount of collat eral thermal injury and threshold power required for welding. The authors compared the threshold power density needed to weld abdominal aortotomies in rabbits with and without photosensitizing dye. With continuous wave diode la ser energy, the threshold for welding using the dye indocyanine green (ICG) was 150 mW (power density 4.8 watts/cm2 at spot diameter of 2 mm). Without dye enhancement, tissue effects were not observed even at the highest energy output available from the laser (300 mW, power density 9.6 watts/cm2). Immediately after welding, the mean bursting pressure for the welds was 260 mm Hg. In survival studies, no anastomotic ruptures, thomboses, or aneurysms were iden tified. Use of photosensitizing dyes for tissue welding is feasible and may allow arterial welding with lower power laser systems and cause less thermal trauma by lowerin...
Noncoherent Detection of Sinusoidal Signals in Sinusoidal Clutter

Probability density expressions associated with the noncoherent detection of a sinusoidal signal have been obtained. The signal is assumed to be imbedded in sinusoidal clutter at the same frequency and narrow-band Gaussian noise. The density expressions are shown to be a function of the signal-to-noise power ratio and the clutter-to-noise power ratio. The expressions have been numerically evaluated for a number of conditions, and the results under each reception hypothesis are presented graphically. Under large-sample conditions, the probability density for a multisample test statistic is shown to be Gaussian, and the probability of detection expression is written such that commonly available tabulated data can be utilized to determine the probabilities.
Congenital Blepharoptosis, Anisometropia, and Amblyopia

A review of the records of 65 patients who had surgery for congenital blepharoptosis of the upper eyelid during a three-year period revealed the preoperative presence of anisometropia, strabismus, or amblyopia in 19 patients. Postoperatively, ten of the 65 patients developed or increased their astigmatism in the operated eye. In four of these patients amblyopia attributed to this postoperative astigmatism developed. The results of our study suggest that blepharoptosis surgery done in the first few years of life may contribute to the development of astigmatism and amblyopia in some patients.
Predicting metastasis of pheochromocytomas using DNA flow cytometry and immunohistochemical markers of cell proliferation: A positive correlation between MIB-1 staining and malignant tumor behavior.

BACKGROUND In the absence of metastases, there are no reliable microscopic features that distinguish malignant from benign pheochromocytomas. Because a common feature of malignancy is the loss of cell cycle regulation and normal growth arrest, the authors hypothesized that analysis of the cell cycle could be used to aid in the diagnosis of malignant pheochromocytoma. METHODS Cell cycle analysis of archival samples of 51 pheochromocytomas (40 sporadic, 11 familial) from 45 patients, including 6 malignant and 45 benign tumors, was conducted. Flow cytometry data and immunohistochemistry for markers of cell proliferation (proliferating cell nuclear antigen [PCNA] and MIB-1 [Ki-67]) were correlated with the authors' clinical data base records, with a mean follow-up of 66 months. RESULTS No correlation of DNA ploidy, S-phase fraction by flow cytometry, or PCNA with malignancy was observed. Staining for the MIB-1 nuclear proliferation marker was positive in 3 of 6 (50%) of the malignant pheochromocytomas and negative in all 45 benign tumors (P< 0.01). CONCLUSIONS Contrary to some previous reports, a diploid DNA pattern does not necessarily predict benign behavior of pheochromocytoma. In this study, cell cycle analysis and, in particular, assessment of the MIB-1 nuclear proliferation marker was useful in the histologic evaluation of pheochromocytoma, as MIB-1 was expressed only in malignant tumors. Cancer 1999;86:1583–9. © 1999 American Cancer Society.
Should we measure dyspnoea in everyone

Dyspnoea is defined as “breathing discomfort” [1]. The paper by GrOnseth et al. [2] in this issue of European Respiratory Journal ( ERJ ) reports the prevalence of dyspnoea in 15 countries throughout the world. There are few studies of dyspnoea in the general population available, so this added information is welcome. The overall prevalence of dyspnoea in their study population was 27%, which is not far out of line with several other studies dating from 1964 to the present [3–5]. Some studies, based on review of medical records, have reported much lower prevalence [6]. However, patients may neglect to report dyspnoea to their clinician because they think it does not reach a sufficient level of importance, or clinicians may fail to record what their patients say. Requiring patients to scale their symptoms can result in more uniform reporting, because the patient does not have to decide how much is reportable, it takes very little time and it facilitates uniform documentation. Busy clinicians may ask “is dyspnoea worth documenting?” One powerful argument for routine assessment is the need to reduce suffering, as with pain. A second argument is the emerging predictive value of dyspnoea in forecasting medical needs. In addition to being prevalent, “dyspnoea” is a powerfully aversive sensation [7] and patients deserve adequate management of this symptom, as passionately argued by Currow et al. [8]. Effective interventions exist and should be used [9–11]; assessing dyspnoea is the first step in managing it. Dyspnoea is frequently overlooked despite its prevalence and the severity of distress it causes [12]. For example, despite having had dyspnoea for months a majority of advanced cancer patients had not received any treatment for it [ …
Inactivation of thromboxane synthase with hydroperoxy-fatty acids.

Abstract Bovine lung thromboxane synthase was immobilized on phenyl-Sepharose beads by adsorption. The immobilized enzyme was catalytically active and synthesized both TXA 2 and HHT. The structure-activity relationship of several hydroperoxy fatty acids and their ability to inactivate thromboxane synthase was investigated. Millimolar quantities of hydrogen peroxide and tert-butylperoxide were required to inactivate the enzyme; whereas micromolar quantities of C 18 and C 20 hydroperoxy fatty acids inactivated the enzyme. Pretreatment of the enzyme with long chain hydroperoxy-fatty acids resulted in a decreased synthesis of both TXB 2 and HHT.
Inhibition of rat liver sulfotransferases SULT1A1 and SULT2A1 and glucuronosyltransferase by dietary flavonoids

1. Dietary flavonoids including kaempferol, quercetin, genistein and daidzein were tested for their ability to alter the conjugation of oestradiol (E2) via rat liver sulfotransferases and glucuronosyltransferase.2. All four flavonoids inhibited the sulfonation of E2 via phenol sulfotransferase, SULT1A1 with IC50s ranging from 0.29 to 4.61 µM. Sulfonation of dehydroisoandrosterone (DHEA) via hydroxysteroid sulfotransferase, SULT2A1, was inhibited by higher amounts of the flavonoids (IC50s ranging from 34 to 116 µM).3. All flavonoids inhibited the formation of E2-β-glucuronides (at carbon atoms 3 and 17) with IC50s ranging from 43 to 260 µM. Glucuronidation of 4-methylumbelliferone (4-MU) was inhibited by high amounts of the flavonoids (IC50s ranging from 860 to 1550 µM).4. Hydrolysis of sulfonated oestrogens via arylsulfatase-c (ARSC) or 4-methylumbelliferone β-glucuronidate (MUG) were not inhibited by the flavonoids.5. It is concluded that SULT1A1 but not SULT2A1 or glucuronosyltransferase is highly sensi...
Portal hypertension and bleeding esophageal varices

Bleeding from esophageal varices exacts a high mortality and extraordinary societal costs. Prophylaxis--medication, sclerotherapy, or shunt surgery to prevent an initial bleeding episode--is ineffective. In patients who have bled from varices, endoscopic injection sclerotherapy can control acute bleeding in more than 90% of patients. Because recurrent bleeding frequently occurs and survival without definitive therapy is dismal, selection of a permanently effective treatment is mandatory once variceal bleeding has been controlled. Long-term injection sclerotherapy can be performed in compliant patients; it is relatively safe but is associated with a 30-50% rebleeding rate. Beta-blockers significantly reduce portal pressure and recurrent bleeding but have not been shown to diminish mortality from BEV. Portal decompressive surgery permanently halts bleeding in more than 90% of patients; the risk of operative mortality is high in decompensated cirrhotics, and long-term complications of encephalopathy and accelerated liver failure may limit indications for shunt surgery to good-risk cirrhotics who are not liver transplant candidates. Devascularization procedures have a low operative mortality and encephalopathy rate but unacceptably high rates of recurrent bleeding. Liver transplantation is curative therapy for bleeding esophageal varices and the associated underlying hepatic dysfunction; cost and availability of donor organs generally limit its use in this setting to variceal bleeders with end-stage liver disease not associated with active alcoholism.
Distributed vibration control and identification of coupled elastic/piezoelectric systems: Finite element formulation and applications

Abstract Recent development of large and flexible structural systems has emphasised the importance of distributed structural identification and vibration control of these high-performance distributed parameter systems (DPSs). In this paper, distributed piezoelectric sensors and actuators are used for structural identification and vibration control of DPSs. The distributed piezoelectric layers can respond to structural oscillation and generate output voltages due to the direct piezoelectric effect; and they can also separately produce control forces/moments due to the converse piezoelectric effect. An improved piezoelectric finite element with internal degree of freedom is first formulated. Then structural identification and control using the piezoelectric finite element is derived. State variable transformation of the dynamic equation is also presented. Distributed structural identification and control of DPSs are studied using theoretical, experimental, and finite element techniques.
Reasoning Under Uncertainty With Dependency Information

Current techniques for dealing with uncertainty in expert systems do not adequately handle dependency information. In fact, most schemes make routine independence assumptions. These assumptions lead to serious questions as to the validity of the conclusions reached by systems which employ such schemes. This paper introduces a technique for reasoning with dependency information in expert systems that acquire probabilistic evidence. This technique relies on a modified version of Dempster-Shafer Theory. In particular, a new support function and updating scheme are used. Examples of several different types of situations are given to show that this modified technique deals with dependency in both an intuitive and reasonable way.
Total synthesis of 2'-deoxytoyocamycin, 2'-deoxysangivamycin and related 7-β-D-arabinofuranosylpyrrolo[2,3-d]pyrimidines via ring closure of pyrrole precursors prepared by the stereospecific sodium salt glycosylation procedure

Abstract A stereospecific high-yield glycosylation of a fully aromatic pyrrole, 2-bromo-(or ethylthio)-5-ethoxymethyleneamino-pyrrole-3, 4-dicarbonitrile( 14a and 14b ) has been accomplished for the first time. Treatment of the sodium salt of 14a or 14b with 1-chloro-2-deoxy-3.5-di- O - p -toluoyl-α- D -erythro-pentofuranose( 5 ) gave exclusively the corresponding blocked nucleosides with β-anomeric configuration ( 15a and 15b ),which on ring closure and further functional group transformation provided the total synthesis of 2'-deoxytoyocamycin ( 3a ) and 2'-deoxysangivamycin ( 3b ). Similar glycosylation of the sodium salt of 14a with 1-chloro-2,3,5-tri- O -benzyl-α- D -arabinofuranose ( 8 ) furnished the corresponding blocked nucleoside ( 17 ), which on ring closure, debromination/debenzylation gave 4-amino-7-β- D -arabinofuranosylpyrrolo[2,3- d ]pyrimidine-5-carboxamide ( 21b ). The synthetic utility of this glycosylation procedure for other saturated pyrroles, pyrrole-3-carbonitrile ( 11 ) and diethyl 3,4-pyrroledicarboxylate ( 4 ) has been demonstrated.
Quick response replenishment: a case study

We document a case study based upon an ongoing analysis for a U.S. fiber/fabric manufacturer who is expanding its operations vertically to include cut and sew operations in Mexico. We refer to this vertically integrated manufacturer as VIM. While some of the data have been changed to protect the sources, the story and results themselves are unchanged. More detail on this case can be found in Moon (1999).
Nano materials for microelectronic packaging

This paper addresses the state-of-the-art nano science and technology regarding next generation high density microelectronics packaging applications, including carbon nanotubes (CNTs) for electrical/thermal interface materials, nano alloys for low temperature surface mount assembly and molecular wires for electrical interconnects.
Humor as Violation and Deprecation: A Cognitive Anthropological Account

Over the past few centuries, scholars have expressed a number of models of humor which are divergent, but potentially complementary. Specifically, the Incongruity Hypothesis posits that humor is our confrontation with a stimulus that is surprising or inconsistent with the way we normally view the world. The Hermetic Hypothesis maintains that the incongruity of humorous statements or events exploits shared cultural (i.e., schematic) knowledge. The Deprecation Hypothesis suggests that humor involves lowering the status of a target individual, group, or object. This paper tests a number of predictions derived from these approaches using statements that isolate the types of violations in both form (i.e., schematic or ontological template violations) and content (i.e., deprecating or non-deprecating). Using cognitive anthropological approaches to the mind, the present results suggest that the most effective forms of humor are deprecating, schematic violations.
Non-adrenergic exploratory behavior induced by moxonidine at mildly hypotensive doses.

Moxonidine is a centrally-active imidazoline compound with preferential affinity for imidazoline receptors (IR) over alpha(2)-adrenoceptors (alpha(2)AR). Clinically, moxonidine has proven advantageous for treating hypertension over pure alpha(2)-adrenergic agonists (i.e., guanabenz) due to its lowered incidence of sedative side effects. The present experiments reveal divergent behavioral effects of low doses of moxonidine and guanabenz in C57Bl/6 mice in an exploratory arena. Low-dose moxonidine (0.05 mg kg(-1) i.p.) elicited an increase in novel object contacts (+36%) and more movement into central space (+56%; P<0.01) compared to saline-injected controls; whereas guanabenz induced only dose-responsive sedative-like behaviors in the same paradigm. Yet, the two agonists were indistinguishable in terms of blood pressure changes over a similar dose range (0.025-0.1 mg kg(-1) i.p.) in consciously free-moving mice (Delta mean+/-S.E.M.=-12.3+/-3.2 mm Hg for moxonidine versus -13.5+/-1.9 mm Hg for guanabenz). As expected of alpha(2)AR involvement, the sedative-like effects of guanabenz were completely blocked by pretreatment with the non-imidazoline alpha(2)AR-antagonist, SKF86466 (0.5 or 1.0 mg kg(-1) i.p.). However, the pro-exploratory effects of low doses of moxonidine (0.05 or 0.1 mg kg(-1)) were not antagonized by SKF86466. These results suggest that moxonidine acts preferentially through a non-adrenergic mechanism, possibly IR-mediated, to elicit pro-exploratory behavior.
The Heparin-coated Vascular Shunt for Thoracic Aortic and Great Vessel Procedures: A Ten-Year Experience

From 1966 to 1976 a flexible, heparin-coated shunt was used for operative procedures on the thoracic aorta and great vessels in 25 patients aged 15 to 78 years. Twenty patients had resection of aneurysms of the descending thoracic aorta. There was 1 death in 15 patients undergoing elective resection and 2 deaths (both from rupturing aneurysms) in 5 patients having emergency resection. The shunt was used in 5 patients who had procedures involving involving the great vessels. There have been no complications attributable to the shunt in either group. The advantages of this shunt include elimination of the need for systemic heparin, avoidance of hypertension during cross-clamping, and adequate perfusion of the distal cirulation without an interposed pump. Because of the ease of handling, low risk, and versatility, we consider the use of this shunt the preferred method for support in elective procedures of the thoracic aorta and great vessels.
Granular Damping in Forced Vibration: Qualitative and Quantitative Analyses

Granular damping is a passive vibration suppression technique which attenuates the response of a vibrating structure by the use of a granule-filled enclosure attached to or embedded in the structure. While promising in many applications especially under harsh conditions, the granular damping mechanism is very complicated and highly nonlinear. In this paper, we perform correlated analytical modeling and numerical studies to evaluate qualitatively and quantitatively the energy dissipation in granular damping. First, an improved analytical model based on the multiphase flow theory is developed for the description of granular motion inside the damper, which accounts for the complete effects of collisions/impacts and dynamic frictions among the granules and between the granules and the enclosure. This model can efficiently characterize the damping effect with high fidelity over a very wide range of parameters, and thus can be used to develop guidelines for parametric studies. With this as a basis, detailed numerical studies using the discrete element method are also carried out to analyze the underlying mechanisms and then provide mechanistic insight for granular damping. In this paper, we focus our attention on the granular damping effect on forced vibrations, which has potential application to a variety of systems.
Effects of dichloroacetate on the lactate/pyruvate ratio and on aspartate and leucine metabolism in cultured rat skeletal muscle cells.

Abstract Dichloroacetate accelerates pyruvate and lactate metabolism in many tissues and has often been shown to increase the lactate/pyruvate (L/P) ratio, which is assumed to be in equilibrium with the cytosolic NADH/NAD + ratio. The cause of the drug-induced increase in L/P ratio is not known, but abnormalities in the malate-aspartate hydrogen shuttle have been implicated in perfused skeletal muscle. In addition, indirect studies in perfused skeletal muscle suggest that dichloroacetate inhibits branched chain amino acid oxidation. In the present studies, cultured rat skeletal muscle cells were used to examine the effect of dichloroacetate on the L/P ratio and on the metabolism of aspartate and of leucine. Dichloroacetate increased the L/P ratio after only 60 min of incubation, and the process was saturable with an ED 50 of 1.0 mM. Drug treatment resulted in marked decreases in cell lactate, pyruvate, and alanine, but no significant differences were observed in cell ATP or in cell levels of compounds of the malate-aspartate shuttle (e.g. malate, aspartate, glutamate or α-ketoglutarate). In addition, dichloroacetate had no consistent effect on aspartate oxidation or on aspartate conversion into glutamate. However, action of the drug did result in an inhibition of leucine oxidation, an effect which contrasts with dichloroacetate action in heart or liver, wherein the drug stimulates leucine oxidation. These results confirm other studies showing that dichloroacetate raises the L/P ratio in skeletal muscle, but do not provide evidence for drug-induced alterations of the malate-aspartate cycle, the principal cytosolic hydrogen shuttle system.
Distribution of fish in the Virgin River, a tributary of the lower Colorado River

The Virgin River, a major tributary of the lower Colorado River, contains a unique, though impoverished, native ichthyofauna (six species) that is largely intact despite the introduction of exotic fishes (13 species) and alterations of the river. The main conclusions of the study are: (1) The longitudinal distribution pattern of the native species does not follow theoretical expectations of a downstream increase in species richness; (2) for the size of the basin (>15,000 km2), the native ichthyofauna is extremely depauperate; and (3) most of the exotic fish are not established in the river, but persist through repeated invasions from downstream reservoirs.
819: Is operative vaginal delivery safe in the preterm fetus?

Tania Esakoff, Yvonne Cheng, Jonathan Snowden, Aaron Caughey Cedars Sinai Medical Center, Obstetrics and Gynecology, Los Angeles, CA, University of California, San Francisco, Obstetrics and Gynecology, San Francisco, CA, Oregon Health and Science University, Obstetrics and Gynecology, Portland, OR OBJECTIVE: Operative vaginal delivery is reported to increase the risk of intracranial hemorrhage in term singletons compared to spontaneous vaginal delivery. There is very limited data on the safety of operative vaginal delivery in preterm fetuses. Our objective was to determine if vacuum assisted vaginal delivery (VAVD) increases the risk of various degrees of neonatal head bleeds compared to forceps assisted vaginal delivery (FAVD) and spontaneous vaginal delivery (SVD) in the preterm cohort. STUDY DESIGN: This was a retrospective cohort study of 111,246 singleton, non-anomalous pregnancies between 32 0 and 36 6 weeks using the California Birth Registry. The cohort consisted of pregnancies undergoing SVD (105,742), VAVD (5,072) and FAVD (432). Outcomes studied included subgaleal hematoma, intracranial hemorrhage and scalp injury which included cephalohematoma. Chi squared tests and Fisher exact test were used for statistical analysis. RESULTS: In the cohort 32 0 to 36 6 weeks, VAVD was associated with an increased risk of subgaleal hematoma (0.16% vs 0.01%) and an increased risk of scalp injury (9.78% vs 2.33%) compared to SVD. FAVD did not appear to increase the risk of subgaleal hematoma (0%) and had an intermediate risk of scalp injury (6.25%). There was no difference in intracranial hemorrhage between groups. (Table 1) When the cohort was further subdivided into an earlier preterm group of 32 0 to 34 6 weeks, similar relationships were seen (Table 2). CONCLUSION: VAVD appears to be associated with an increased risk of subgaleal hematoma and scalp injury compared to SVD and FAVD in the preterm cohort. This should be considered when choosing the mode of delivery in a preterm fetus.
What do rapidity gaps say about clustering

The sensitivity of the rapidity gap-length distribution to the degree of clustering among the secondaries in hadronic final states is investigated in several models. It is concluded that, without further theoretical assumptions, an adequate account of the data can be obtained from a wide range of models. The analysis of rapidity gaps in exclusive channels is also discussed.
The effects of temperature on the physiology of crustacean nerves and muscles

Abstract 1. 1.|The effects of temperature on crustacean motor nerve, muscle and synaptic physiology have been reviewed in terms of passive properties, threshold potentials and response characteristics. 2. 2.|The generation of additional spikes in the peripheral branches of certain axons has been discussed. 3. 3.|Temperature effects on behaviour have been reviewed.
Ultra-Short Pulies of Heavy Ions

The bunching requirements for a heavy-ion tandemlinac accelerator are defined and a bunching system to satisfy these requirenents is outlined. This discussion introduces an experimrent on the bunching of 45 MeV 16O ions by means of a ?/2 superconducting-helix resonator. The measured ion-bunch width is 64 psec, a value daminated by the resolution width of the ion detector. By correcting for the detector-resolution width one infers that the ion bunch itself is <40 psec wide.
Relation of Sleep-Entrained Human Prolactin Release to REM-NonREM Cycles

ABSTRACT Human plasma prolactin (hPRL) concentrations were measured by radioimmunoassay in samples drawn at 20-min intervals from 14 normal male subjects during 58 nights of polygraphically monitored sleep. The hPRL-sleep histogram plots often showed a cyclic relation between recurrent REM periods and hPRL nadirs and between subsequent nonREM (Stage 2–4) segments and hPRL rises and peaks. The hPRL data were then tabulated as REM, nonREM or Wake values. To allow comparison between subjects and between sleep cycles of different lengths, sleep onset and the ends of REM periods were used as reference points within each sleep pattern. Backward from these reference points at 20-min intervals were tabulated pre-sleep Wake and REM values, respectively. Forward from these points, at 20-min intervals, were tabulated nonREM values. Thus, these tabular hPRL data now represented release patterns within sequential sleep onset and REM–nonREM cycles across sleep. Subject and group averages of these data clearly evidenced...
Sadat's Open Door: Opposition from Within

The divisive social consequences of the open door policy, combined with dissatisfactions generated by the blocked Sadat peace initiative, produce broad if still inchoate domestic opposition to the fundamental policies of the Sadat regime. In such a changed climate the weakened welfare dimension of Free Officer rule and the coalescence of elements from a wide spectrum of opposition opinion may prove crucial in diminishing the ability of Egypt's present ruler to carry the country with him in his economic and foreign policy reorientations.
Migration calculations for water in the exosphere of the Moon: Dusk-dawn asymmetry, heterogeneous trapping, and D/H fractionation

Water ice is trapped in permanently shadowed craters near the lunar poles, where it is thought to have arrived from an exogenic or endogenic source via ballistic hops. We use a model of the migration of water molecules in the lunar exosphere to investigate three problems: (1) A strong continuous source would lead to an enhanced concentration of H2O at the morning terminator but not at the evening terminator. Hence, spectral features observed at both terminators do not suggest that there is diurnal migration of volatiles. (2) Cold trapping after a comet impact leads to an unequal partitioning between the two hemispheres depending on the latitude of the impact but to nearly equal partitioning with respect to longitude. (3) The D/H fractionation as the water molecules migrate toward the poles is small. Hence, the isotopic composition of ice deposits in the cold traps can be related to that of the source.
Assessing Mental Health Needs in the Rural Community: A Critique of Assessment Approaches

The subject of rural mental health has received increased attention over the past two decades. Numerous studies have revealed unique problems and assets particular to rural communities. To receive federal funding, mental health needs of a particular area must be demonstrated, yet the government has never prescribed just how needs assessments should be accomplished. Largely due to a lack of direction, many approaches and instruments have been used with varying degrees of success. This lack of consistency makes the comparison of studies very dificult. In order to serve these areas better, a reliable method for assessing mental health needs requires development. In general, there are five busic approaches that can be used in assessing mental health needs: key informant, community forum, social indicators, rates-under-treatment, and survey. lke nature of needs assessment combined with the particular needs and characteristics of rural communities made these five approaches more or less desirable. In order to evaluate each approach critically, a number of criteria were selected from the literature and then systematically applied to each approach. Each approach was then evaluated from the perspective of the appropriateness of its utilization in a rural community. It is recommended that before undertaking a comprehensive mental health needs assessment, the nurse planner first evaluate the agency’s request for a needs assessment. It is essential to determine how specific the needs assessment information should be.
Manipulating the graphical representation of query results in geographic information systems

An investigation into how the properties of spatial data, in particular their graphical representation, influence the interaction between user and system is presented. Of particular interest are the concepts humans have about spatial data and the operations that allow them to manipulate and examine the graphical representation of spatial data. An overview of the architecture of spatial information systems is given, concentrating on user interfaces for spatial data handling. An investigation into how users manipulate the representation of spatial data is given, followed by the introduction of the corresponding operations necessary to examine the representation. A series of interface snapshots is given to demonstrate these ideas in a simulated user interface. >
Photon-counting solid-state photomultiplier

The solid state photomultiplier is a silicon device capable of continuous detection of individual photons in the wavelength range from 0.4 to 28 mu m. Operated with an applied bias near 7 V the device responds to the absorption of an incident photon with a submicrosecond-risetime current pulse with a narrow amplitude distribution well above the electronic readout noise levels. Optimal photon-counting performance occurs between 6 and 10 K and for count rates less than 10/sup 10/ counts/s/cm/sup 2/ of detector area. A 60% counting quantum efficiency has been demonstrated at 20 mu m, and near 60% was observed in the visible light region. The underlying mechanism involves extremely fast internal charge amplification by impact ionization of impurity-band electrons and results in a pulse for each photoelectrically or thermally induced free carrier. The thermally induced dark pulse rate at 7 K is sufficiently low that background-limited detector performance is obtained at a background of less than 10/sup 6/ photons/cm/sup 2/ s. >
Glypican-3–Targeted 89Zr PET Imaging of Hepatocellular Carcinoma: Where Antibody Imaging Dares to Tread

Recently we have seen an increase in PET imaging of 89Zr-radiolabeled antibodies in preclinical and clinical investigations, particularly in oncology. 89Zr-antibodies are examples of the immuno-PET imaging class, in which antibodies equipped with a PET isotope are detected and quantified in vivo.
A new model-based estimation of ellipses for object representation

Fitting geometric models to objects of interest in images is one of the most classical problems studied in computer vision field. As a result of its strong representation power and flexibility, conic is one of the geometric primitives widely used in a large number of image analysis applications, in practice. As opposed to most existing conic fitting methods minimizing the fitting error with the use of the second order polynomial representation, in this paper, we propose a new method that formulates the geometric fitting problem as a process of seeking for the optimal mapping to a bivariate normal distribution model. As a result, some critical disadvantages tightly coupled with those methods following the routine polynomial representation can be well overcome. To demonstrate this, a set of carefully designed comparison experiments is conducted to show the superiority of the newly proposed method to a representative method using the polynomial representation. Additionally, the practical effectiveness of the proposed method is further manifested using a set of real image data with a promising accuracy.
Interpolation for ambulatory ECG measurements

The application of local interpolation techniques to improve the measurement of ambulatory electrocardiogram (ECG) parameters is discussed. The method allows the processing of the ambulatory ECG data using low sampling rates and obtains reasonably accurate measurements of the QRS complex. The ECG parameters were measured using both uninterpolated and interpolated data. it was found that the results obtained with local interpolation were closer to the actual values. The added execution time per beat was 16 mu s, which is about 12% of the average time to analyze a beat at the normal heart rate of 72 and a playback speed of 100 times the real time. The improvement in classification accuracy is believed to justify the added processing time. >
A simple one-pot synthesis of cyclopropane [11C]carbonyl chloride. Synthesis and biodistribution of [11C]cyclorphan

A rapid, one-pot, synthesis of cyclopropane [11C]carbonyl chloride was developed. This synthesis proceeded in 80% radiochemical yield (EOB) in a synthesis time of 10 minutes. This acid chloride was then used to synthesize a model compound, [11C]cyclorphan, by alkylation of norlevorphanol followed by reduction of the intermediate [11C]amide in an overall synthesis time of 55 minutes and a radiochemical yield of 15% (EOB). The biodistribution of [11C]cyclorphan in control and naloxone pretreated mice showed non-specific binding and rapid clearance from brain.
Molecular Mechanisms of Magnetosome Formation

Magnetotactic bacteria are a diverse group of microorganisms with the ability to use geomagnetic fields for direction sensing. This unique feat is accomplished with the help of magnetosomes, nanometer-sized magnetic crystals surrounded by a lipid bilayer membrane and organized into chains via a dedicated cytoskeleton within the cell. Because of the special properties of these magnetic crystals, magnetotactic bacteria have been exploited for a variety of applications in diverse disciplines from geobiology to biotechnology. In addition, magnetosomes have served as a powerful model system for the study of biomineralization and cell biology in bacteria. This review focuses on recent advances in understanding the molecular mechanisms of magnetosome formation and magnetite biomineralization.
Review of the Genus Paria (Coleoptera: Chrysomelidae) of North America

New distribution records are given for the Northern Plains species Paria thoracica (Melsheimer), P. opacicollis LeConte, P. quadrinotata (Say), P. sexnotata (Say), P. quadriguttata LeConte, P. scutellaris (Notman), and the strawberry rootworm, P. fragariae Wilcox, in North Dakota, South Dakota, and Minnesota, with some remarks on their morphological variation. New distribution records also are included for P. frosti Wilcox, P. virginiae Wilcox, P. aterrima (Olivier), P. blatchleyi Wilcox, P. sexnottata (Say), and P. opacicollis LeConte. P. fragariae kirki is described as a new subspecies which occurs chiefly in southeastern United States and has been recorded on Rosa sp. P. pratensis , the host of which is Rosa setigera Michaux, is described as a new species, primarily occurring in the Northern Plains States, and P. wilcoxi is described as a new species from Alabama, its host being Taxodium distichum (L.). These newforms are incorporated into a key to species.
Natural Hydrocarbon Seepage in the Gulf of Mexico

ABSTRACT The Department of Oceanography at Texas AM and survivors of DeSoto's group used tar found along the Texas-Louisiana coast to caulk their boats. From 1902-1909 heavy oil slicks were noted in an area about 100 miles south of the Louisiana coast and the locations plotted on charts issued by the United States Coast and Geodetic Survey. Oil spouting into the air was reported in the same area in 1909, as well as oil ponds off the Sabine Pass area. Reports of seeps in the Gulf of Mexico are numerous, and the Department's study has located several general areas of seepage within and around the Gulf. Tar samples from these areas have been collected and analyzed chemically, as well as samples found floating in the Gulf. The seep sites have been studied geologically and geophysically, and pertinent chemical, biological, and physical oceanographic characteristics have been determined.
Nonbehavioral Selection for Pawns, Mutants of PARAMECIUM AURELIA with Decreased Excitability

The reversal response in Paramecium aurelia is mediated by calcium which carries the inward current during excitation. Electrophysiological studies indicate that strontium and barium can also carry the inward current. Exposure to high concentrations of barium rapidly paralyzes and later kills wild-type paramecia. Following mutagenesis with nitrosoguanidine, seven mutants which continued to swim in the ;high-barium' solution were selected. All of the mutants show decreased reversal behavior, with phenotypes ranging from extremely non-reversing (;extreme' pawns) to nearly wild-type reversal behavior (;partial' pawns). The mutations fall into three complementation groups, identical to the pwA, pwB, and pwC genes of Kunget al. (1975). All of the pwA and pwB mutants withstand longer exposure to barium, the pwB mutants surviving longer than the pwA mutants. Among mutants of each gene, survival is correlated with loss of reversal behavior. Double mutants (A-B, A-C, B-C), identified in the exautogamous progeny of crosses between ;partial' mutants, exhibited a more extreme non-reversing phenotype than either of their single-mutant (;partial' pawn) parents.---Inability to reverse could be expected from an alteration in the calcium-activated reversal mechanism or in excitation. A normal calcium-activated structure was demonstrated in all pawns by chlorpromazine treatment. In a separate report (Schein, Bennett and Katz 1976) the results of electrophysiological investigations directly demonstrate decreased excitability in all of the mutants, a decrease due to an altered calcium activation. The studies of the genetics, the survival in barium and the electro-physiology of the pawns demonstrate that the pwA and pwB genes have different effects on calcium activation.