cssi/SciSciGPT-SciSciNet huggingface dataset:
Social and professional issues: online naturally

IT 2008 calls for social and professional issues to be infused throughout the curriculum, noting that it is appropriate to also cover them in a separate course. Our technique for helping students get the most out of this area of the body of knowledge is to use provocative student led discussions to promote a lively and interactive exchange of ideas. Examples of discussion starters that have been successful in stimulating lively and thoughtful topical discussions in the online course Social and Professional Issues in IT/IS are shared as well as lessons learned.
Test of the assumption of the scaling law for polymer monolayers.

The assumption of the scaling law, that the monomer structure remains constant as the polymer concentration changes from the dilute to semidilute regime, has been tested by use of optical second-harmonic generation. The monomer orientation does not change as the polymer concentration is increased. This observation is the first confirmation of the basic assumption of the scaling law which describes polymer behavior in two-dimensional space.
Role of Neuropeptide-Y in Episodic Luteinizing Hormone Release in Ovariectomized Rats: An Excitatory Component and Opioid Involvement*

We tested the hypothesis that hypothalamic neuropeptide-Y (NPY) is an excitatory signal in the episodic secretion of LH in ovariectomized (ovx) rats and that the suppression of LH secretion that consistently follows intracerebroventricular administration of NPY is due to concurrent release of opioids or CRH, both previously shown to readily inhibit LH release. In the first experiment, ovx rats received continuous intraventricular infusion of either serum containing NPY antibodies (NPY-Ab) or normal rabbit serum (control) at dilutions of 1:5 or 1:1. NPY-Ab infusion at a 1:5 dilution significantly decreased mean plasma LH levels and LH pulse amplitude without affecting LH pulse frequency over a 3-h period of observation. However, infusion of relatively more concentrated NPY-Ab (1:1) markedly decreased not only mean plasma LH levels and LH pulse amplitude, but also the frequency of LH episodes. In the next experiment, we observed that intraventricular administration of NPY (0.2 nmol) suppressed LH release fo...
Comparison of Reconstruction Algorithms for an Electronically Collimated Gamma Camera

The performance of different iterative algorithms has been studied for reconstructing emission images of single gamma emitters, using a new gamma camera based upon an electronic method of collimation. Adaptations of the ART, SIRT, and Iterative Least Squares algorithms have been studied. The algorithms have been compared via simulation with respect to the rate of convergence, sensitivity to noise, resolution, and contrast of the reconstructed image. Results have also been obtained with experimentally measured data from a point source of Tc-99m.
Increased AT1 receptors in adrenal gland of AT2 receptor gene-disrupted mice

Abstract Angiotensin II (Ang II) AT2 receptor-gene disrupted mice have increased systemic blood pressure and response to exogenous Angiotensin II. To clarify the mechanism of these changes, we studied adrenal AT1 receptor expression and mRNA by receptor autoradiography and in situ hybridization in female AT2 receptor-gene disrupted mice (agtr 2−/−) and wild-type controls (agtr 2+/+). We found high expression of AT1 receptor binding and mRNA in adrenal zona glomerulosa of female wild-type mice. AT2 receptors and mRNA were highly expressed in adrenal medulla of wild-type mice, but were not detected in zona glomerulosa. There was no AT2 receptor binding or mRNA in adrenal glands of AT2 receptor-gene disrupted mice. In these animals, AT1 receptor binding and mRNA were increased in adrenal zona glomerulosa and AT1 receptor mRNA was increased in the adrenal medulla when compared with wild-type animals. The present data support the hypothesis of an interaction or cross talk between AT2 and AT1 receptors in adrenal gland. The significant increase in AT1 receptor expression in the absence of AT2 receptor transcription may be partially responsible for the increased blood pressure and for the enhanced response to exogenously administered Angiotensin II in this model.
Service Oriented Architecture for VoIP Conferencing

Most current Voice/Video over IP (VoIP) systems are either highly centralized or dependent on IP multicast. We propose the Global Multimedia Collaboration System as a scalable, integrated and service-oriented VoIP conferencing system, based on a SOAP-based collaboration framework and advanced messaging oriented middleware. This system can provide media and session services to heterogeneous endpoints including H.323, SIP, Access Grid, and RealPlayer as well as accommodating diverse clients such as cellular phones. We suggest that our approach opens up new opportunities for extending classic VoIP systems by using these new technologies designed for scalable Internet based service-oriented computing. Copyright © 2006 John Wiley & Sons, Ltd.
A novel compliant linear-motion mechanism based on parasitic motion compensation

Abstract In this paper, the center shift of the generalized cross-spring pivot is taken advantage of to compensate for the inherent parasitic motion of the compliant parallel four-bar mechanism. So the rectilinear motion of a linear-motion mechanism, which is constructed by several leaf springs or cartwheel flexural pivots, is improved. The compliant linear-motion mechanism is firstly modeled by making use of the building block method. Then the compensation condition for the parasitic motion is obtained. Meanwhile, the approach to large stroke and small parasitic error is proposed, for the sake of achieving a high performance rectilinear mechanism. Furthermore, the validity and effectiveness are verified by finite element analysis (FEA). Finally, both the qualitative and quantitative analyses show that the advantages of this linear-motion mechanism are remarkable, and the application prospect in precision engineering is promising.
Strengthening Effective Parenting Practices Over the Long Term: Effects of a Preventive Intervention for Parentally Bereaved Families

This study tested the effect of the Family Bereavement Program (FBP), a preventive intervention for bereaved families, on effective parenting (e.g., caregiver warmth, consistent discipline) 6 years after program completion. Families (n = 101; 69% female caregivers; 77% Caucasian, 11% Hispanic) with children between ages 8 and 16 who had experienced the death of one parent were randomized to the FBP (n = 54) or a literature control condition (n = 47). Multiple regression analyses conducted within a multilevel framework indicated that the FBP had a significant positive impact on a multirater, multimeasure assessment of parenting at 6-year follow-up, controlling for pretest levels of parenting and child mental health problems. Mediation analyses showed that short-term program effects on parenting, including caregiver warmth and effective discipline, significantly mediated the impact of the FBP on effective parenting 6 years later. These findings indicate that a relatively cost-effective brief intervention fo...
Are bacterial ‘autotransporters’ really transporters?

Autotransporters are bacterial outer membrane proteins that consist of a large N-terminal extracellular domain ('passenger domain') and a C-terminal beta-barrel domain ('beta domain'). The beta domain was originally proposed to function as a channel that transports its own passenger domain across the outer membrane. Results of recent structural, biochemical and molecular genetic studies, however, have challenged this idea. Here I describe an alternative model in which translocation of the passenger domain is mediated by an exogenous factor (possibly a newly identified factor necessary for assembly of outer membrane proteins called 'Omp85/YaeT'), whereas the beta domain only targets the protein to the outer membrane and serves as a membrane anchor.
15(S)-hydroxyeicosatetraenoic acid–induced angiogenesis requires Src-mediated Egr-1–dependent rapid induction of FGF-2 expression

To understand the mechanisms underlying 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE]–induced angiogenesis, we studied the role of Egr-1. 15(S)-HETE induced Egr-1 expression in a time-dependent manner in human dermal microvascular endothelial cells (HDMVECs). Blockade of Egr-1 via forced expression of its dominant-negative mutant attenuated 15(S)-HETE–induced HDMVEC migration and tube formation as well as Matrigel plug angiogenesis. 15(S)-HETE–induced Egr-1 expression requires Src activation. In addition, adenovirus-mediated expression of dominant-negative mutant of Src blocked 15(S)-HETE's effects on migration and tube formation of HDMVECs and Matrigel plug angiogenesis. 15(S)-HETE induced fibroblast growth factor-2 (FGF-2) expression rapidly via Src-mediated production of Egr-1. Cloning and mutational analysis of FGF-2 promoter revealed that Egr-1 binding site proximal to transcription start site is required for 15(S)-HETE–induced FGF-2 expression. Neutralizing antibody-mediated suppression of FGF-2 function also attenuated the effects of 15(S)-HETE on HDMVEC migration and tube formation as well as Matrigel plug angiogenesis. Furthermore, in contrast to wild-type mice, 12/15-LOX−/− mice exhibited decreased Matrigel plug angiogenesis in response to AA, which was rescued by 15(S)-HETE. On the basis of these observations, we conclude that 15(S)-HETE–induced angiogenesis requires Src-mediated Egr-1–dependent rapid induction of FGF-2. These findings may suggest that 15(S)-HETE could be a potential endogenous regulator of pathologic angiogenesis associated with atherosclerosis and restenosis.
Detector development for Jefferson Lab’s 12 GeV Upgrade

Abstract Jefferson Lab will soon finish its highly anticipated 12 GeV Upgrade. With doubled maximum energy, Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) will enable a new experimental program with substantial discovery potential, addressing important topics in nuclear, hadronic and electroweak physics. In order to take full advantage of the high energy, high luminosity beam, new detectors are being developed, designed and constructed to fit the needs of different physics topics. The paper will give an overview of various new detector technologies to be used for 12 GeV experiments. It will then focus on the development of two solenoid-based spectrometers, the GlueX and SoLID spectrometers. The GlueX experiment in Hall D will study the complex properties of gluons through exotic hybrid meson spectroscopy. The GlueX spectrometer, a hermetic detector package designed for spectroscopy and the associated partial wave analysis, is currently in the final stage of construction. Hall A, on the other hand, is developing the SoLID spectrometer to capture the 3D image of the nucleon from semi-inclusive processes and to study the intrinsic properties of quarks through mirror symmetry breaking. Such a spectrometer will have the capability to handle very high event rates while still maintaining a large acceptance in the forward region.
Effect of cholesterol incorporation on the sensitivity of liposomes to the polyene antibiotic, filipin

Abstract 1. 1. A simple spectrophotometric assay has been developed by which the effect of lytic agents on liposomes can be conveniently determined. This method is based on the change in absorbance at 340 mμ which occurs when trapped glucose is liberated in the presence of hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49). Because the spectrophotometric assay is more sensitive (requiring lower concentrations of liposomes), it possesses several advantages over alternative procedures which have been used to study the release of trapped markers. 2. 2. It has been reported that the polyene antibiotic, filipin, did not produce a greater release of marker when cholesterol was incorporated into the liposomes. This problem has been re-examined with the spectrophotometric assay. Our results indicate that the presence of sterol does increase the sensitivity of the liposomes to the antibiotic. These observations are consistent with previous lipid monolayer and bilayer experiments and the known biological properties of the polyene antibiotics.
Self-healing polymers: Sticky when wet.

Inspired by the chemistry of adhesive proteins in mussels, hydrogels can now be made to self-heal in water without the aid of metal chelates.
Does the Presence of Preoperative LUTS Affect Urinary Outcomes after Radical Prostatectomy

Urinary incontinence is one of the most common adverse effects after radical prostatectomy (RP). Preoperative lower urinary tract symptoms (LUTS), which increase in prevalence with advancing age, have been hypothesized to be related to postoperative urinary continence. We review the literature on the role of preoperative LUTS on postoperative urinary function after RP in patients with clinically localized prostate cancer. The precise role of preoperative LUTS on postoperative urinary continence after RP is unclear due to conflicting conclusions from numerous reports. However, correlating preoperative LUTS to postoperative urinary incontinence may be particularly relevant in three instances: in patients with preoperative voiding or emptying LUTS, in predicting early postoperative urinary continence, and in patients with preoperative urinary incontinence. Also, RP in patients with moderate to severe preexisting LUTS may improve postoperatively as a result of relief of obstruction.
First Report of Plectosporium Blight on Pumpkin Caused by Plectosporium tabacinum in Alabama

In October of 2001, Plectosporium tabacinum (van Beyma) M.E. Palm, W. Gams, & H.I. Nirenberg (formerly known as Microdochium tabacinum (von Arx, 1984) and Fusarium tabacinum (Gams & Gerlagh, 1968)) was observed in field plantings of pumpkin (Cucurbita pepo L.) in Cullman and Jackson counties in north Alabama. Symptoms were white or tan, spindle-shaped lesions on the stems and leaf petioles and slightly raised, corky, white or light brown lesions on pumpkin fruit and fruit stems. Pumpkin symptoms were identical to a previous description of P. tabacinum (published as M. tabacinum) on pumpkin, zucchini, and yellow summer squash (1). Disease severity ranged from less than 10% stem tissue damage on pumpkins in Cullman County to 40 to 45% stem tissue damage on pumpkins in Jackson County. A field section of pumpkins in Jackson County sprayed with azoxystrobin (Quadris 2.08F, 0.20 kg a.i./ha) alternated weekly with chlorothalonil (Bravo Ultrex, 2.44 kg a.i./ha) beginning at vine-run had stem damage of approximately 5% compared to approximately 45% stem damage on pumpkins in an unsprayed field section. A 50% reduction in marketable fruit due to P. tabacinum was observed in the unsprayed field section compared to the section sprayed weekly with fungicides. When thin slices of lesions were taken from stem and fruit surfaces using a scalpel and examined microscopically, one- or two-celled, hyaline, bilaterally symmetric spores, 7.0 to 8.5 × 2.8 to 3.0 μm were observed. The ends of the spores were slightly narrowed and rounded. Spore characteristics were identical to previous descriptions of P. tabacinum produced in culture and on diseased pumpkins and squash (2,3). Surface-sterilized tissue from fruit lesion margins was plated on potato dextrose agar and incubated under light (Sylvania Gro-Lux, 40w) with a light/dark cycle of 12 h at 23°C. After 10 days, spores were observed that were similar to those from fruit except they were multiguttulate and had a phialide arrangement. The fungal mycelium was pale pink to pale orange and closely appressed to the agar. Fungal characteristics in culture agree with a previous description of P. tabacinum in culture (2). To our knowledge, this is the first report of P. tabacinum in Alabama. References: (1) S. C. Bost and C. A. Mullins. Plant Dis. 76:861, 1992. (2) M. E. Palm et al. Mycologia 87(3):397, 1995; (3) T. A. Zitter. Microdochium blight. Page 28 in: Compendium of Cucurbit Diseases. T. A. Zitter, D. L. Hopkins, and C. E. Thomas, eds. The American Phytopathological Society, St. Paul, MN, 1996.
Non-metastatic squamous cell carcinoma within a Rathke's cleft cyst.

Primary intracranial and sellar squamous cell carcinoma is an extremely rare entity, usually caused by malignant transformation of epidermoid cysts, or very rarely other non-malignant epithelial cysts. Malignant transformation of a Rathke’s cleft cyst has never been described. We present a 49-year-old male patient who presented with a 3-month history of progressive frontotemporal headaches. Imaging revealed a 1.2 cm cystic pituitary mass consistent with a hemorrhagic Rathke’s cleft cyst. The patient underwent trans-sphenoidal resection of the pituitary cyst, and pathologic analysis revealed a squamous cell carcinoma lining a Rathke’s cleft cyst. Extensive imaging and otorhinolaryngologic evaluation revealed no primary source for metastasis. We feel this represents the first case of a patient with a pituitary lesion in which presentation and MRI imaging were consistent with Rathke’s cleft cyst, yet histology revealed squamous cell carcinoma in situ.
Review Article: Nerve Conduction Studies in Infants and Children:

The electrophysiologic evaluation of peripheral nerves may provide critically important information, both with respect to diagnosis and prognosis, in the child with a suspected neuromuscular disord...
PRO-C4 OF HUMAN PLASMA: ISOLATION AND DESCRIPTION OF CHEMICAL AND ANTIGENIC PROPERTIES*

The fourth component of complement (C4) occurs in human plasma as a protein with a three polypeptide chain structure. Lately a single-chain form of C4 has been purified from human plasma by sequential steps of immunoadsorbent chromatography, gel filtration in 6 M guanidine hydrochloride, and gel filtration in 6 M guanidine hydrochloride and 0.015 M dithiothreitol. Single-chain C4, referred to as pro-C4, behaved as a protein of approximately 200,000 daltons upon gel filtration, and was separated from the three chains of C4 on the basis of molecular size. Pro-C4 could be isolated from each of five human plasmas examined and was found to constitute approximately 2% of total, immunoreactive C4. Replicate amino acid analyses of pro-C4 and C4 agreed within 0.5 mol % for all residues except glycine and threonine, which agreed within 0.7 mol percent. Polyacrylamide gel electrophoresis of pro-C4 in the presence of sodium dodecyl sufate in 5% gels under reducing conditions indicated an approximate molecular weight of 202,000. The sum of the molecular weights of the alpha-, beta-, and gamma-chain of C4 is 205,000. After gel electrophoresis, pro-C4 stained positively with periodic acid-Schiff reagent, suggesting the presence of covalently-bound carbohydrate. Competitive inhibition radioimmune assays with pro-C4, purified alpha-, beta-, or gamma-chain, and chain-specific antisera demonstrated the existence of antigenic sites on pro-C4 that are assignable to common determinants on each of the alpha-, beta-, and gamma-chains of C4.
Review: Preoperative brain natriuretic peptide level is an independent predictor of adverse cardiovascular events after noncardiac surgery

Source Citation Karthikeyan G, Moncur RA, Levine O, et al. Is a pre-operative brain natriuretic peptide or N-terminal pro-B-type natriuretic peptide measurement an independent predictor of adverse ...
Subject pool sign-up procedures: A threat to external validity

The extent to which introductory psychology students' self-selection into experiments produced biased samples was assessed in two experiments. As part of the normal sign-up procedure, students chose between apparently different experiments with quite different descriptions and between individual and group sign-up slots. Upon arriving at the laboratory, all students filled out personality questionnaires. Results demonstrated that students sorted themselves into experiments as well as into individual group sign-up slots in relation to personality dimensions. The resulting samples in each experiment were thus non-representative of even the restricted introductory psychology subject population. Implications and recommendations for the use of such populations were discussed.
Differential Roles of Hyperglycemia and Hypoinsulinemia in Diabetes Induced Retinal Cell Death: Evidence for Retinal Insulin Resistance

Diabetes pathology derives from the combination of hyperglycemia and hypoinsulinemia or insulin resistance leading to diabetic complications including diabetic neuropathy, nephropathy and retinopathy. Diabetic retinopathy is characterized by numerous retinal defects affecting the vasculature and the neuro-retina, but the relative contributions of the loss of retinal insulin signaling and hyperglycemia have never been directly compared. In this study we tested the hypothesis that increased retinal insulin signaling and glycemic normalization would exert differential effects on retinal cell survival and retinal physiology during diabetes. We have demonstrated in this study that both subconjunctival insulin administration and systemic glycemic reduction using the sodium-glucose linked transporter inhibitor phloridzin affected the regulation of retinal cell survival in diabetic rats. Both treatments partially restored the retinal insulin signaling without increasing plasma insulin levels. Retinal transcriptomic and histological analysis also clearly demonstrated that local administration of insulin and systemic glycemia normalization use different pathways to counteract the effects of diabetes on the retina. While local insulin primarily affected inflammation-associated pathways, systemic glycemic control affected pathways involved in the regulation of cell signaling and metabolism. These results suggest that hyperglycemia induces resistance to growth factor action in the retina and clearly demonstrate that both restoration of glycemic control and retinal insulin signaling can act through different pathways to both normalize diabetes-induced retinal abnormality and prevent vision loss.
Air embolus following pulmonary interstitial emphysema in hyaline membrane disease.

Two cases of hyaline membrane disease are presented complicated by severe, interstitial emphysema and resulting in death from air embolus. This is consistent with the experimental evidence of other investigators that shows that such an air embolus may be a more common complication of hyaline membrane disease than previously expected.
Unsupervised Multilingual Learning for POS Tagging

We demonstrate the effectiveness of multilingual learning for unsupervised part-of-speech tagging. The key hypothesis of multilingual learning is that by combining cues from multiple languages, the structure of each becomes more apparent. We formulate a hierarchical Bayesian model for jointly predicting bilingual streams of part-of-speech tags. The model learns language-specific features while capturing cross-lingual patterns in tag distribution for aligned words. Once the parameters of our model have been learned on bilingual parallel data, we evaluate its performance on a held-out monolingual test set. Our evaluation on six pairs of languages shows consistent and significant performance gains over a state-of-the-art monolingual baseline. For one language pair, we observe a relative reduction in error of 53%.
Interleukin-6 Stimulates Placental Lactogen Expression by Human Trophoblast Cells*

Interleukin-6 (IL-6) stimulates the release of hCG from syncytiotrophoblast cells, but the effects of IL-6 and other cytokines on the release of placental lactogen (hPL) are unknown. To determine the effect of IL-6 on hPL release, we exposed an enriched fraction of trophoblast cells (prepared by the isopycnic centrifugation of enzymatically dispersed term placenta) continuously to IL-6 (500 U/ml) for up to 6 days. The amounts of hPL released by the IL-6-exposed cells during days 3 and 6 were 177.6 +/- 2.4% and 267.5 +/- 12.6% that of control cells, respectively (P < 0.0001 in each instance). In addition, the hPL messenger RNA (mRNA) contents of the IL-6-exposed cells after 3 and 6 days of exposure were 2.2- and 4.7-fold that of control cells. The stimulatory effect of IL-6 on hPL release and hPL mRNA levels was dose dependent, with a minimal effective dose of 50 U/ml. IL-1 beta, which is known to stimulate IL-6 production by human trophoblast cells, also stimulated dose-dependent increases in hPL release and hPL mRNA levels. IL-6 (500 U/ml) had no effect on trophoblast differentiation, but stimulated a 20-fold increase in hPL promoter activity in BeWo choriocarcinoma cells transfected transiently with a plasmid containing 2.3 kilobases of the hPL promoter coupled to the chloramphenicol acetyltransferase gene. In addition, BeWo cells exposed to IL-6 (500 U/ml) for 3 and 6 days contained 2.4- and 3.2-fold more hPL mRNA levels than control cells. Because placental macrophages and syncytiotrophoblast cells release IL-6, these results strongly suggest an autocrine/paracrine role for IL-6 in the regulation of hPL release. The increase in hPL release appears to be due at least in part to an increase in hPL gene expression.
DNA Immunization Against Amyloid beta 42 has High Potential as Safe Therapy for Alzheimer’s Disease as it Diminishes Antigen-Specific Th1 and Th17 Cell Proliferation

The pathogenesis of Alzheimer’s disease (AD) has been strongly associated with the accumulation of amyloid beta (Aβ) peptides in brain, and immunotherapy targeting Aβ provides potential for AD prevention. A clinical trial in which AD patients were immunized with Aβ42 peptide was stopped when 6% of participants showed meningoencephalitis, apparently due to an inflammatory Th1 immune response. Previously, we and other have shown that Aβ42 DNA vaccination via gene gun generates a Th2 cellular immune response, which was shown by analyses of the respective antibody isotype profiles. We also determined that in vitro T cell proliferation in response to Aβ42 peptide re-stimulation was absent in DNA Aβ42 trimer-immunized mice when compared to Aβ42 peptide-immunized mice. To further characterize this observation prospectively and longitudinally, we analyzed the immune response in wild-type mice after vaccination with Aβ42 trimer DNA and Aβ42 peptide with Quil A adjuvant. Wild-type mice were immunized with short-term (1–3× vaccinations) or long-term (6× vacinations) immunization strategies. Antibody titers and isotype profiles of the Aβ42 specific antibodies, as well as cytokine profiles and cell proliferation studies from this longitudinal study were determined. Sufficient antibody titers to effectively reduce Aβ42, but an absent T cell proliferative response and no IFNγ or IL-17 secretion after Aβ42 DNA trimer immunization minimizes the risk of inflammatory activities of the immune system towards the self antigen Aβ42 in brain. Therefore, Aβ42 DNA trimer immunization has a high probability to be effective and safe to treat patients with early AD.
SIGNATURE OF SURFACE STATES ON NMR CHEMICAL SHIFTS : A THEORETICAL PREDICTION

We show with an {ital ab initio} calculation that electronic surface states have a strong effect on NMR chemical-shift spectra. For the hydrogen-chemisorbed diamond (111) surface, we find that the atomic layers close to the surface experience a variation of the chemical shift, which is proportional to the density of empty surface states. This effect could be used as a direct probe of the surface-state density profile, by measuring experimentally the NMR chemical shift resolved for each atomic layer. {copyright} {ital 1999} {ital The American Physical Society}
■REVIEW : The Nuclear Magnetic Resonance Revolution in Basic and Clinical Neuroscience

Nuclear magnetic resonance (NMR) methods for the noninvasive, chemically specific investigation of living tissue have proliferated in number and advanced greatly in power since the first NMR images of anatomy appeared in the 1970s. By 1994, about 50 different NMR measurements had become available for the study of normal and pathological brain. These include aspects of biochemistry, angiography, perfusion, activation- sensitive metabolic rates for glucose and oxygen, monitoring of function through activation-induced changes in blood flow and water diffusion, and normal and pathological anatomy with submillimeter resolution. At least as many more measurements of biomedical importance are under development. Neuroscience research and management of neurological illness will be profoundly affected by NMR methods as they mature and become routine. The Neuroscientist 1:84-94, 1995
Identification of a new chloroplast carbonic anhydrase in Chlamydomonas reinhardtii

Carbonic anhydrases (CA) are zinc-containing metalloenzymes that catalyze the reversible hydration of CO2. The three evolutionarily unrelated families of CAs are designated α-, β-, and γ-CA. Aquatic photosynthetic organisms have evolved different forms of CO2 concentrating mechanisms (CCMs) to aid Rubisco in capturing CO2 from the surrounding environment. One aspect of all CCMs is the critical roles played by various specially localized extracellular and intracellular CAs. Five CAs have previously been identified in Chlamydomonas reinhardtii, a green alga with a well-studied CCM. Here we identify a sixth gene encoding a β-type CA. This new β-CA, designated Cah6, is distinct from the two mitochondrial β-CAs in C. reinhardtii. Nucleotide sequence data show that the Cah6 cDNA contains an open reading frame encoding a polypeptide of 264 amino acids with a leader sequence likely targeting the protein to the chloroplast stroma. We have fused the Cah6 open reading frame to the coding sequence of maltose-binding protein in a pMal expression vector. The purified recombinant fusion protein is active and was used to partially characterize the Cah6 protein. The purified recombinant fusion protein was cleaved with protease Factor Xa to separate Cah6 from the maltose-binding protein and the purified Cah6 protein was used to raise an antibody. Western blots, immunolocalization studies, and northern blots collectively indicated that Cah6 is constitutively expressed in the stroma of chloroplasts. A possible role for Cah6 in the CCM of C. reinhardtii is proposed.
A factor from Trypanosoma cruzi induces repetitive cytosolic free Ca2+ transients in isolated primary canine cardiac myocytes.

An unusual 120-kDa alkaline peptidase contained in a trypomastigote soluble fraction (TSF) of Trypanosoma cruzi is associated with the induction of repetitive Ca2+ transients and subsequent invasion by the parasite of a number of mammalian cell lines, including tissue culture L6E2 myoblasts (B. A. Burleigh and N. W. Andrews, J. Biol. Chem. 270:5172-5180, 1995; S. N. J. Moreno, J. Silva, A. E. Vercesi, and R. Docampo, J. Exp. Med. 180:1535-1540, 1994; A. Rodriguez, M. G. Rioult, A. Ora, and N. W. Andrews, J. Cell Biol. 129:1263-1273, 1995; I. Tardieux, M. H. Nathanson, and N. W. Andrews, J. Exp. Med. 179:1017-1022, 1994). Using single cell spectrofluorometry and whole-cell patch clamping, we show that TSF produces rapid repetitive cytosolic Ca2+ transients (each associated with cell contraction) in primary cardiac myocytes isolated from dogs. The response of myocytes to TSF was dose dependent in that increasing numbers of cells responded to increasing concentrations of TSF. The TSF-induced Ca2+ transients could be obliterated when TSF was heated or treated with trypsin or the protease inhibitor leupeptin. Aprotinin, pepstatin A, and E-64 did not affect TSF activity. The TSF-induced Ca2+ transients and trypomastigote cell invasion could not be inhibited by alpha (prazosin)- or beta (propanolol)-adrenergic blockers or L-type Ca2+ channel blockers (verapamil, nisoldipine, or cadmium) or by removal of extracellular Ca2+. However, inhibition of pertussis toxin-sensitive G proteins and Ca2+ release from the sarcoplasmic reticulum (with thapsigargin or ryanodine) prevented the TSF-induced Ca2+ transients and cell invasion by trypomastigotes. These data suggested that cardiac myocyte pertussis toxin-sensitive G proteins are associated with the regulation of TSF-induced Ca2+ transients and myocyte invasion by trypomastigotes but are independent of Ca2+ entry into the cytosol via L-type Ca2+ channels. The Ca2+ transients are dependent on release of Ca2+ from sarcoplasmic reticulum Ca2+ stores, but this release is not dependent on extracellular Ca2+ or on the classic model of Ca2+ -induced Ca2+ release in cardiac myocytes. Further, subthreshold depolarizations, together with cell contraction as demonstrated by whole-cell patch clamping, occurred with each Ca2+ transient. However, the depolarizations were of magnitude insufficient to generate an action potential, providing further evidence for a lack of dependence on L-type Ca2+ channels and other voltage-dependent channels (Na+ and K+ channels) in the generation of TSF-induced Ca2+ transients. Our findings suggest that primary canine cardiac myocytes respond to TSF and parasite invasion in ways similar to those of the in vitro cell lines studied to date. Since cardiac myocytes are primary targets for T. cruzi in the vertebrate host, our study indicates that TSF may play a role in the pathogenesis of Chagas' disease in humans.
Black Clergy and Urban Regimes: The Role of Atlanta’S Concerned Black Clergy

ABSTRACT:This study examines the involvement of black ministers in urban regimes through a case study of Atlanta’s Concerned Black Clergy organization. In the early years of black political leadership, the black clergy were promoters of racial solidarity, oftentimes against the interests of low income residents. With black political leadership secure, the clery emerged as frequent critics of development policies during Andrew Young’s years as mayor. More recently, the Concerned Black Clergy have become active regime participants helping to influence policy decisions on behalf of the city’s poorer citizens. Through their organizational efforts, the Concerned Black Clergy have become part of the process of regime change in the city.
Gendered Difference, Violent Imagination Blood, Race, Nation

Racism, misogyny, and the propagation of politicomilitary violence are analyzed as an integral part of the construction of Western modernity. With a focus on German public culture, the author emphasizes the interplay of gender and race against the background of medical models, documenting how fears of natural disasters (women, Jews, refugees) and medical pathologies such as dirt and infection (bodily infestations) are continuously recycled to reinforce a racialist postmodern culture.
Evaluation of a psychophysiologically controlled adaptive automation system, using performance on a tracking task.

Three experiments were conducted to evaluate the performance of a psychophysiologically controlled adaptive automation system. Subjects were asked to perform a compensatory tracking task while their electroencephalogram (EEG) was recorded and an engagement index was derived from the EEG, using the alpha, beta, and theta bandwidths: β/(α + θ) and β/θ. In Experiment I, EEG was recorded from three different sites: frontal, parietal, and temporal. Although tracking performance did not differ as a function of site, the number of task mode allocations was greater under a negative feedback contingency than under a positive feedback contingency. This effect was seen primarily from frontal sites. Experiments II and III evaluated the adaptive automation system, using extended runs under positive and negative feedback with either a slope (Experiment II) or absolute (Experiment III) criterion used to drive the system. Using either criterion, performance was found to be significantly better under negative feedback. Future evaluation and use of psychophysiologically controlled adaptive automation systems are discussed.
The changed leadership landscape: what matters today

Purpose – The purpose of this paper is to present challenges in leadership performance today, as well as leadership styles that have potential, given the contemporary shifts in performance climate. Design/methodology/approach – This paper is based on empirical research, obtained through methodological triangulation, partly through critical literature review, and partly through the author’s ongoing leadership studies during the past ten years, to be subdivided in three phenomenological studies, and 72 structured leadership interviews. Findings – There is a multitude of factors that keep changing the leadership landscape, and there is a series of leadership skills that suffice well given the parameters of today’s work environments. Nine of these leadership styles are presented, including their main characteristics and contemporary usefulness. Research limitations/implications – The studies reviewed, although in-depth, applied to a limited set of options. Because leadership is such a broad and dynamic topic,...
A profile-driven statistical analysis framework for the design optimization of soft real-time applications

Soft real-time applications lack a formal methodology for their design optimization. Well-established techniques from hard real-time systems cannot be directly applied to soft real-time applications, without losing key benefits of the soft real-time paradigm. We introduce a statistical analysis framework that is well-suited for discovering opportunities for optimization of soft real-time applications. We demonstrate how programmers can use the analysis provided by our framework to perform aggressive soft real-time design optimizations on their applications. The paper introduces the Context Execution Tree (CET) representation for capturing the statistical properties of function calls in the context of their execution in the program. The CET is constructed from an offline-profile of the application. Statistical measures are coupled with techniques that extract runtime distinguishable call-chains. This combination of techniques is applied to the CET to find statistically significant patterns of activity that i) expose slack in the execution of the application with respect to its soft real-time requirements, and ii) can be predicted with low overhead and high reliability during the normal execution of the application.
Myosin Binding Protein C in the Heart

See related article, pages 1290–1298 Myocardial force generation is initiated on the release of calcium ions from the sarcoplasmic reticulum and subsequent activation of the contractile apparatus.1 A schematic of the cardiac sarcomere and some of its component proteins is shown in the Figure.2 Contractile activation involves binding calcium to Tn-C, redistribution of the affinity of Tn-I for Tn-C away from Tn-T, and movement of tropomyosin on the thin filament, thereby exposing binding sites on actin. Binding of the myosin S1 domain to actin leads to cross-bridge force development. However, this simple two state model of muscle contraction is not sufficient to explain many features of muscle contraction.2 For example, the rate of force development critically depends on the activation state of the thin filament.2 Also, binding of a modified myosin (NEM-S1 which cannot hydrolyze ATP) has been shown to abolish this phenomenon.3 This, and other structural evidence, has led to the hypothesis that the thin filament must have at least three states: a blocked state (top left), where tropomyosin sterically blocks S1 binding; a closed state, induced by calcium binding to Tn-C, where tropomyosin has shifted away somewhat allowing weak interaction with the S1 domain; and an open state, where tropomyosin has moved away fully allowing for a strong interaction with S1 and force generation (bottom).2 One interesting aspect of this theory is that the binding of myosin to actin by itself induces further activation of the thin filament, thus facilitating S1 domain binding along the filament; an elegant, yet simple molecular model of cooperative activation. Cardiac muscle activation is highly cooperative, even though calcium binding to isolated cardiac troponin-C itself is not cooperative.2,4 However, it is less clear how modulation of cross-bridge cycling rate could be accommodated by such a …
Replication and segregation of a miniF plasmid during the division cycle of Escherichia coli

Replication of the miniF plasmid pML31 was examined during the division cycle of Escherichia coli growing with doubling times between 40 and 90 min at 37 degrees C and compared to the replication of plasmid pBR322 and the minichromosome pAL70. The replication pattern of pML31 was indistinguishable from that of pBR322 at all growth rates and very different from the cell-cycle-specific replication of the minichromosome. It is concluded that both pML31 and pBR322 plasmids can replicate at all stages of the division cycle, with a probability of replication that increases gradually, but perhaps not exponentially, during the cycle. In contrast, the modes of segregation of pML31 and pBR322 plasmids into daughter cells at division appeared to differ, raising the possibility that pML31 may segregate in a nonrandom fashion similar to that of chromosomes and minichromosomes.
Prediction of the Three‐Dimensional Structure for the Rat Urotensin II Receptor, and Comparison of the Antagonist Binding Sites and Binding Selectivity between Human and Rat Receptors from Atomistic Simulations

Urotensin-II (U-II) has been shown to be the most potent mammalian vasoconstrictor known. Thus, a U-II antagonist might be of therapeutic value in a number of cardiovascular disorders. However, interspecies variability of several nonpeptidic ligands complicates the interpretation of in vivo studies of such antagonists in preclinical animal disease models. ACT058362 is a selective antagonist for the human U-II receptor (hUT2R) with a reported K_d value of ∼4 nM in a molecular binding assay, but it is reported to bind weakly to rat UT2R (rUT2R), with a K_d value of ∼1 500 nM. In contrast, the arylsulphonamide SB706375 is a selective antagonist against both hUT2R (K_d=∼9 nM) and rUT2R (K_d=∼21 nM). To understand the species selectivity of the UT2R, we investigated the binding site of ACT058362 and SB706375 in both hUT2R and rUT2R to explain the dramatically lower (∼400-fold) affinity of ACT058362 for rUT2R and the similar affinity (∼10 nM) of SB706375 for both UT2Rs. These studies used MembStruk and MSCDock to predict the UT2R structure and the binding site of ACT058362 and SB706375. Based on binding energies, we found two binding modes each with D130^(3.32) as the crucial anchoring point (Ballesteros–Weinstein numbering given in superscript). We predict that ACT058362 (an aryl–amine–aryl or ANA ligand) binds in the transmembrane (TM) 3456 region, while SB706375 (an aryl–aryl–amine or AAN ligand) binds in the TM 1237 region. These predicted sites explain the known differences in binding of the ANA ligand to rat and human receptors, while explaining the similar binding of the AAN compound to rat and human receptors. Moreover the predictions explain currently available structure–activity relationship (SAR) data. To further validate the predicted binding sites of these ligands in hUT2R and rUT2R, we propose several mutations that would help define the structural origins of differential responses between UT2R of different species, potentially indicating novel UT2R antagonists with cross-species high affinity.
Evaluation of Error Metrics for Image Registration of Multiple Images

When two or more images of a scene are joined, one would like to know the accuracy of the joined image. In this paper we carry out a comparison of several different error metrics which are computed directly from the given images and their join (i.e., no "ground truth" value is assumed). We compare the error metrics by correlating them with a map registration error which we regard as a "ground truth" or "gold standard." The goal is to have a notion of reliability of the different error metrics which will be valid when ground truth reference is not available. This analysis should be a useful tool for quantifying aspects of image registration algorithms and for tuning the parameters of the registration algorithm.
Performing thoractomy in the emergency center

The acutely injured patient may require emergency thoracotomy as an integral part of his resuscitation. Thoracotomy in the emergency center for control of hemorrhage, cardiac compression, preservation of available fluid volume, and direct repair of critical injuries can be lifesaving. Between January of 1970 and December of 1972, over 5,000 emergency operations were performed for blunt and penetrating trauma at Ben Taub General Hospital. Emergency thoracotomy was required in approximately 300 cases. In 106 patients the urgency of their condition required thoracotomy in the emergency center. Among these 106 patients, 67% of those who arrived with discernible vital signs and whose injuries were limited to the intrathoracic organs, were resuscitated. There were 33 initial survivors, eight of whom had both intrathoracic and extrathoracic injuries. Long term survivors, discharged from the hospital, totaled 27. Cardiac wounds were successfully controlled in 20 patients. Thoracotomy in the emergency center for cardiac resuscitation was rarely successful when injuries were limited to extrathoracic organs. Urgent thoracotomy in the emergency center environment is an adjunct to resuscitation and allows control of reversible intrathoracic injuries. Autotransfusion, emergency cardiopulmonary bypass, fine screen filtration of transfused blood, and intravascular shunts have been applied as extensions of this life saving measure.
Twitch-dependent SR Ca accumulation and release in rabbit ventricular myocytes

Using caffeine-induced contractures (Ccaf) and thapsigargin (TG), we estimated the fraction of sarcoplasmic reticulum (SR) Ca released at one twitch and also the number of twitches required to reload a Ca-depleted SR. Similar results were obtained for twitches or intracellular Ca (Cai) transient with the fluorescent indicator, indo 1. Sustained exposure to 10 mM caffeine completely depletes the SR of Ca in < 5 s (as assessed by a second Ccaf). After such Ca depletion, four to five twitches are necessary to reload the SR to the steady-state level (with a twitch constant, tau = 1.6 twitches). We also determined the time required for complete inhibition of the SR Ca-adenosinetriphosphatase (ATPase) by TG. After SR Ca depletion, 5 microM TG was applied for different periods of time before a train of "reloading" twitches. A TG exposure period of 90 s was sufficient to completely prevent Ccaf after these reloading twitches. When SR is Ca depleted, the twitch is larger in the presence of TG, indicating that the SR Ca-ATPase can limit the ability of Ca influx to activate contraction. To assess SR Ca released at one twitch in cells with normally Ca-loaded SR, 5 microM TG was applied for 90 s to prevent SR Ca reuptake. Then one or several twitches were activated (causing SR Ca release, but with reuptake completely blocked). After the twitch (or train), a Ccaf was used to assess remaining SR Ca.(ABSTRACT TRUNCATED AT 250 WORDS)
Toward More Gender Diversity in CS through an Artificial Intelligence Summer Program for High School Girls

The field of computer science suffers from a lack of diversity. The Stanford Artificial Intelligence Laboratory's Outreach Summer (SAILORS), a two-week non-residential free summer program, recruits high school girls to computer science, specifically to Artificial Intelligence (AI). The program was organized by graduate student and professor volunteers. The goals of the pilot program are to increase interest in AI, contextualize technically rigorous AI concepts through societal impact, and address barriers that could discourage 10th grade girls from pursuing computer science. In this paper we describe the curriculum designed to achieve these goals. Survey results show students had a statistically significant increase in technical knowledge, interest in pursuing careers in AI, and confidence in succeeding in AI and computer science. Additionally, survey results show that the majority of the students found new role models, faculty support, and a sense of community in AI and computer science.