cssi/SciSciGPT-SciSciNet huggingface dataset:
ORIGINS AND CONSEQUENCES OF SERPENTINE ENDEMISM IN THE CALIFORNIA FLORA

Habitat specialization plays an important role in the creation and loss of biodiversity over ecological and evolutionary time scales. In California, serpentine soils have a distinctive flora, with 246 serpentine habitat specialists (i.e., endemics). Using molecular phylogenies for 23 genera containing 784 taxa and 51 endemics, we infer few transitions out of the endemic state, which is shown by an analysis of transition rates to simply reflect the low frequency of endemics (i.e., reversal rates were high). The finding of high reversal rates, but a low number of reversals, is consistent with the widely hypothesized trade-off between serpentine tolerance and competitive ability, under which serpentine endemics are physiologically capable of growing in less-stressful habitats but competitors lead to their extirpation. Endemism is also characterized by a decrease in speciation and extinction rates and a decrease in the overall diversification rate. We also find that tolerators (species with nonserpentine and serpentine populations) undergo speciation in serpentine habitats to give rise to new serpentine endemics but are several times more likely to lose serpentine populations to produce serpentine-intolerant taxa. Finally, endemics were younger on average than nonendemics, but this alone does not explain their low diversification.
Circular dichroism studies—I

Abstract The CD spectra of a number of rigid aromatic compounds containing an asymmetric center adjacent to the aromatic ring are reported. From the CD spectra of compounds of known absolute configuration it has been possible to devise a quadrant rule which predicts the absolute configuration of molecules possessing an asymmetric center adjacent to the aromatic ring. The rule has been tested with representative members of the indole, Amaryllidaceae, morphine, and isoquinoline type alkaloids of known absolute configuration.
Regulating Telecommunications in Developing Countries: Outcomes, Incentives, and Commitment

The private sector invests heavily in infrastructure, makes reasonable returns, and improves productivity when regulators reduce the firm?s information advantage, induce the firm (through pricing) to operate efficiently, and institute safeguarding mechanisms to protect the firm against expropriation of assets or quasi-rents. In response to the recent wave of privatizing and regulating monopolies in developing countries, Galal and Nauriyal evaluate the impact of different regulatory schemes on private sector behavior in the telecommunications sector in seven countries. They find that regulation is most effective - meaning, it results in substantial investment by the private sector, reasonable returns on this investment, and greater productivity - where the government/regulators reduce the firm's information advantage, induce the firm (through pricing) to operate efficiently, and institute safeguarding mechanisms to protect the firm against expropriation of assets or quasi-rents. Conversely, where the government/regulators fail to resolve information, incentive, and commitment problems, private sector returns are relatively high, and investment and productivity are relatively low. This paper - a product of the Finance and Private Sector Development Division, Policy Research Department - is part of a larger effort in the department to investigate the influence of institutions on policy outcomes.
A counterexample concerning smooth approximation

We answer a question of Smith, Stanoyevitch and Stegenga in the negative by constructing a simply connected planar domain Q with no twosided boundary points and for which every point on QC is an m2-limit point of QC and such that C' (Q) is not dense in the Sobolev space Wk,P(Q).
Locating the first nodal linein the Neumann problem

The location of the nodal line of the first nonconstant Neumann eigenfunction of a convex planar domain is specified to within a distance comparable to the inradius. This is used to prove that the eigenvalue of the partial differential equation is approximated well by the eigenvalue of an ordinary differential equation whose coefficients are expressed solely in terms of the width of the domain. A variant of these estimates is given for domains that are thin strips and satisfy a Lipschitz condition.
Improving Lattice Based Cryptosystems Using the Hermite Normal Form

We describe a simple technique that can be used to substantially reduce the key and ciphertext size of various lattice based cryptosystems and trapdoor functions of the kind proposed by Goldreich, Goldwasser and Halevi (GGH). The improvement is significant both from the theoretical and practical point of view, reducing the size of both key and ciphertext by a factor n equal to the dimension of the lattice (i.e., several hundreds for typical values of the security parameter.) The efficiency improvement is obtained without decreasing the security of the functions: we formally prove that the new functions are at least as secure as the original ones, and possibly even better as the adversary gets less information in a strong information theoretical sense. The increased efficiency of the new cryptosystems allows the use of bigger values for the security parameter, making the functions secure against the best cryptanalytic attacks, while keeping the size of the key even below the smallest key size for which lattice cryptosystems were ever conjectured to be hard to break.
A wideband wavelength discriminator using 3/spl times/3 directional coupler

Fiber interferometers have been widely used as wavelength discriminators of fiber Bragg grating sensors. The positive and negative slopes of the interferometer's transfer function can be used as an effective sensors wavelength discriminator, which convert Bragg wavelength shift to variations of the transmitted optical intensity. However due to its periodicity, the dynamic range of measurement is limited by the quasi-linear range in the slopes. The fluctuating phase bias, which is temperature dependent, is also a limiting factor of interferometric measurement because it leads to the variation in the system sensitivity. To solve the problems while maintaining high-resolution, a newly developed quadrature signal processing is applied to the photodetector signals.
Mg2+-dependent compaction and folding of yeast tRNAPhe and the catalytic domain of the B. subtilis RNase P RNA determined by small-angle X-ray scattering.

We apply synchrotron-based small-angle X-ray scattering to investigate the relationship between compaction, metal binding, and structure formation of two RNAs at 37 °C: the 76 nucleotide yeast tRNAPhe and the 255 nucleotide catalytic domain of the Bacillus subtilis RNase P RNA. For both RNAs, this method provides direct evidence for the population of a distinct folding intermediate. The relative compaction between the intermediate and the native state does not correlate with the size of the RNA but does correlate well with the amount of surface burial as quantified previously by the urea-dependent m-value. The total compaction process can be described in two major stages. Starting from a completely unfolded state (4−8 M urea, no Mg2+), the major amount of compaction occurs upon the dilution of the denaturant and the addition of micromolar amounts of Mg2+ to form the intermediate. The native state forms in a single transition from the intermediate state upon cooperative binding of three to four Mg2+ ions....
Conservation of Pathogenic TCR Homology across Class II Restrictions in Anti-Ribonucleoprotein Autoimmunity: Extended Efficacy of T Cell Vaccine Therapy

T cells have been shown to mediate aspects of anti-ribonucleoprotein (RNP) autoimmunity, and are a potential target of therapy in lupus and related diseases. In this study, we assessed the relevance of a conserved class of anti-RNP T cells to autoimmune disease expression and therapy. Our data show that anti-RNP T cell selection induced a limited set of homologous CDR3 motifs at high frequency. Homologous CDR3 motifs have been reported in other autoimmune diseases. Vaccination with irradiated anti-RNP (but not anti–tetanus toxoid) CD4 + cells induced remission of anti-RNP–associated nephritis in ≥80% of treated mice, even with donor/recipient MHC class II mismatch, and in both induced and spontaneous autoimmunity. Vaccine responder sera inhibited anti-70k T cell proliferation and bound hybridomas expressing the conserved CDR3 motifs. Our data indicate that a limited set of TCR CDR3 motifs may be important for the pathogenesis of anti-RNP lupus and other autoimmune diseases. The ability to target a consistent set of pathogenic T cells between individuals and across class II restrictions may allow for the more practical development of a standardized anti-RNP T cell vaccine preparation useful for multiple patients.
Toward the Creation of an Electrophysiological Atlas for the Pre-operative Planning and Intra-operative Guidance of Deep Brain Stimulators (DBS) Implantation

In current practice, optimal placement of deep brain stimulators (DBSs) is an iterative procedure. A target is chosen pre-operatively based on anatomical landmarks identified on MR images. This point is used as an initial position that is refined intra-operatively using both micro-electrode recordings and macro-stimulation. We hypothesize that boundaries of nuclei and sub-nuclei not visible in the anatomic images can be resolved in atlases that include electrophysiological information, thus improving both pre- and intra-operative guidance. In this work we report on our current progress toward creating such an atlas. We also present results we have obtained in creating an atlas of optimal target points that can be used for automatic pre-operative selection of the targets. We demonstrate that initial points selected with this atlas are closer to the final points than the initial points chosen manually.
Neurochemical and cellular reorganization of the spinal cord in a murine model of bone cancer pain

The cancer-related event that is most disruptive to the cancer patient's quality of life is pain. To begin to define the mechanisms that give rise to cancer pain, we examined the neurochemical changes that occur in the spinal cord and associated dorsal root ganglia in a murine model of bone cancer. Twenty-one days after intramedullary injection of osteolytic sarcoma cells into the femur, there was extensive bone destruction and invasion of the tumor into the periosteum, similar to that found in patients with osteolytic bone cancer. In the spinal cord, ipsilateral to the cancerous bone, there was a massive astrocyte hypertrophy without neuronal loss, an expression of dynorphin and c-Fos protein in neurons in the deep laminae of the dorsal horn. Additionally, normally non-noxious palpation of the bone with cancer induced behaviors indicative of pain, the internalization of the substance P receptor, and c-Fos expression in lamina I neurons. The alterations in the neurochemistry of the spinal cord and the sensitization of primary afferents were positively correlated with the extent of bone destruction and the growth of the tumor. This "neurochemical signature" of bone cancer pain appears unique when compared to changes that occur in persistent inflammatory or neuropathic pain states. Understanding the mechanisms by which the cancer cells induce this neurochemical reorganization may provide insight into peripheral factors that drive spinal cord plasticity and in the development of more effective treatments for cancer pain.
Sleep: An Expanding Field of Practice and Research

exposure to Information about sleep and remain unaware of the relation ship between sleep and the clinical is sues of depression, erectile dysfunc tion, alcoholism, and anxiety.2 Domi nated by psychiatry and psychology, a quiet revolution in sleep research and treatment has begun.3 Social work can benefit from this new knowledge and, because so many social work clients suffer from sleep disorders, workers can help advance practice and research in this area.
The 22-kD Peroxisomal Integral Membrane Protein in Zellweger Syndrome—Presence, Abundance, and Association with a Peroxisomal Thiolase Precursor Protein

The 22-kD Peroxisomal Integral Membrane Protein in Zellweger Syndrome—Presence, Abundance, and Association with a Peroxisomal Thiolase Precursor Protein
Estimate of the attenuation coefficient using a clinical array transducer for the detection of cervical ripening in human pregnancy

Premature delivery is the leading cause of infant mortality in the United States. Currently, premature delivery cannot be prevented and new treatments are difficult to develop due to the inability to diagnose symptoms prior to uterine contractions. Cervical ripening is a long period that precedes the active phase of uterine contractions and cervical dilation. The changes in the microstructure of the cervix during cervical ripening suggest that the ultrasonic attenuation should decrease. The objective of this study is to use the reference phantom algorithm to estimate the ultrasonic attenuation in the cervix of pregnant human patients. Prior to applying the algorithm to in vivo human data, two homogeneous phantoms with known attenuation coefficients were used to validate the algorithm and to find the length and the width of the region of interest (ROI) that achieves the smallest error in the attenuation coefficient estimates. In the phantom data, we found that the errors in the attenuation coefficients estimates are less than 12% for ROIs that contain 40 wavelengths or more axially and 30 echo lines or more laterally. The reference phantom algorithm was then used to obtain attenuation maps of the echoes from two human pregnant cervices at different gestational ages. It was observed that the mean of the attenuation coefficient estimates in the cervix of the patient at a more advanced gestational age is smaller than the mean of the attenuation coefficient estimates in the cervix of the patient at an earlier gestational age which suggests that ultrasonic attenuation decreases with increasing gestational age. We also observed a large variance between the attenuation coefficient estimates in the different regions of the cervix due to the natural variation in tissue micro-structures across the cervix. The preliminary results indicate that the algorithm could potentially provide an important diagnostic tool for diagnosing the risk of premature delivery.
Evaluation of information retrieval systems: A decision theory approach

The Swets model of information retrieval, based on a decision theory approach, is discussed, with the overall performance measure being the crucial element reexamined in this paper. The Neyman-Pearson criterion from statistical decision theory, and based on likelihood ratios, is used to determine an optimal range of Z, the variable assigned to each document by the retrieval system in an attempt to discriminate between relevant and nonrelevant documents. This criterion is shown to be directly related to both precision and recall, and is equivalent to the maximization of the expected value of the retrieval decision for a specific query and a given document under certain conditions. Thus, a compromise can be reached between those who advocate precision as a measure, due partially to its ability to be easily measurable empirically, and those who advocate consideration of recall. Several cases of the normal and Poisson distributions for the variable Z are discussed in terms of their implications for the Neyman-Pearson decision rule. It is seen that when the variances are unequal, the Swets rule of retrieving a document if its Z value is large enough is not optimal. Finally, the situation of precision and recall not being inversely related is shown to be possible under certain conditions. Thus, this paper attempts to extend the understanding of the theoretical foundations of the decision theory approach to information retrieval.
Tethyan heritage in the development of the Neogene Umbria‐Marche fold‐and‐thrust belt, Italy: a 3D approach

The Umbria-Marche fold-and-thrust belt (Northern Apennines, Italy), provides excellent opportunities to evaluate the structural heritage of the opening of the Mesozoic Tethys Ocean in the 3D geometry of the Neogene compressional structures related to the Alpine Orogeny. The structure and evolution of a portion of the southernmost belt, between the Nera River and the Rieti Basin, are described as a field example, and the kinematics along well-exposed Mesozoic extension structures are provided. Cross-section restoration shows a close coincidence between these extension structures and the Neogene thrust ramps, thus suggesting that the geometry of the latter was controlled by the map distribution of the former. Sequential balancing also allows for the definition of the geometrical pattern of pre-existing normal faults, which were produced in response to a unidirectional or a two-directional extension stress field. The inferred direction of principal extension, corrected for the effects of late deformation, is consistent with that proposed for the northern margin of the Adria Promontory in global-scale plate tectonic reconstructions.
Meta-analysis of preoperative placement of pancreatic stents to prevent postoperative leaks after distal pancreatectomy

Abstract Background Pancreatic leaks and fistulae are common after distal pancreatectomy. The aim of this study was to determine effectiveness of prophylactic pancreatic duct (PD) stents on leak rate following distal pancreatectomy. Methods A meta-analysis of five studies including 218 patients. PD stents were placed endoscopically in two studies and intraoperatively in three studies. Octreotide was given postoperatively in one study. Results No significant difference in leak rates was seen with PD stents; however, when the study that also used Octreotide was removed, PD stents were favorable. Conclusion Placement of PD stents for prevention of PD leaks and fistulae following distal pancreatectomy cannot be routinely recommended.
SMAD7 directly converts human embryonic stem cells to telencephalic fate by a default mechanism

Human embryonic stem cells (hESCs) provide a valuable window into the dissection of the molecular circuitry underlying the early formation of the human forebrain. However, dissection of signaling events in forebrain development using current protocols is complicated by non-neural contamination and fluctuation of extrinsic influences. Here, we show that SMAD7, a cell-intrinsic inhibitor of transforming growth factor-β (TGFβ) signaling, is sufficient to directly convert pluripotent hESCs to an anterior neural fate. Time course gene expression revealed downregulation of MAPK components, and combining MEK1/2 inhibition with SMAD7-mediated TGFβ inhibition promoted telencephalic conversion. Fibroblast growth factor-MEK and TGFβ-SMAD signaling maintain hESCs by promoting pluripotency genes and repressing neural genes. Our findings suggest that in the absence of these cues, pluripotent cells simply revert to a program of neural conversion. Hence, the "primed" state of hESCs requires inhibition of the "default" state of neural fate acquisition. This has parallels in amphibians, suggesting an evolutionarily conserved mechanism.
The effects of sodium alginate and other untested polymers on radiostrontium retention in the rat.

SummaryAt levels of 1, 5, and 10%, sodium alginate, guar gum, carboxymethyl guar gum, and Questran were tested in diets fed to rats to determine their effects on radiostrontium skeletal retention. Alginate was the only effective agent against radiostrontium retention, approaching, at the 10% level, 70% less 89Sr skeletally retained than radio-control animals and a 3-fold improvement over natural biological strontium-calcium discrimination. The strontium-binding ability shown by alginate was probably clue to its functional carboxyl groups.
Language Revival in France: The Regional Idioms

RESUMOLingva revivigo en Francio: La regionaj idiomojPer akceptiĝo de la Rezolucio Kuijper en 1987, la eŭropaj regionaj lingvoj ŝoviĝis en la unuan vicon. Analizo de la situacio en Francio bone ilustras la demandon, ĉar tiu lando entenas ene de siaj limoj ne malpli ol sep regionajn lingvojn, kaj montriĝis aparte malema agnoski la rajtojn de regionaj lingvoj. Tiu sinteno kontraŭas la francan politikon antaŭ-enigi sian lingvon eksterlande kaj samtempe denunci la negativan influon de la angla. Efektive, ne nur temas pri tio, ke la bretona, cataluna, okcitana, vaska kaj korsika, kaj la germanaj kaj nederlandaj dialektoj, restis sen akceptigo en Francio, sed, ke ili submetiĝis al severa persekuto tra la jaroj kaj ĝenerale suferis la negativan influon de la franca.La artikolo prezentas historian superrigardon de franca regionlingva leĝfarado kaj analizon de la nuna stato de la regionaj idiomoj en edukado, la amasmedioj kaj la regis-taro. La aŭtoro ekzamenas la naciajn kaj internaciajn organizajojn kreitajn por antaŭenigi la malpli uzatajn lingvojn, kaj esploras la regionlingvan demandon en la kunteksto de la translima merkato proponita por la jaro 1992.SOMMAIRELa reprise des langues en France: Les langues regionalesL'adoption de la Resolution Kuijper par le Parlement europeen, en 1987, a mis au premier plan les langues regionales de l'Europe. Nous examinerons la situation en France pour illustrer cette question du fait que ce pays compte non moins de sept langues regionales, et qu'il se montre particulierement peu dispose a reconnaitre les droits de ses minorites linguistiques ce qui est en contradiction avec sa politique de promouvoir le francais a l'etranger en meme temps que ses dirigeants declament l'influence nefaste qu'exerce l'anglais sur la langue nationale. Non seulement le breton, l'occitan, le catalan, le basque, le corse, le flamand, l'alsacien et le francique n'ont pas ete pleinement acceptees par le gouvernement central mais elles ont egalement ete soumises a une persecution terrible au fil des ans et ont ete largement contaminees par l'influence de la langue dominante, c'est-a-dire du francais.Nous presenterons donc un survol historique de la legislation adoptee en France au sujet des langues regionales et une analyse de la situation actuelle de ces dernieres au sein du systeme educatif, des media et des niveaux gouvernementaux. Les organisations nationales et internationales creees aux fins de promouvoir les soi-disantes "langues moins repandues" et la question des langues regionales dans le contexte de l'Europe de 1992 seront egalement examinees.
O Sujeito, Ele Está Aqui! A Posição Variável dos Sujeitos Preverbais

This paper analyzes preverbal overt subjects, comparing Brazilian Portuguese to (other) null-subject languages, especially within Romance. It explores syntactic and semantic properties, including resumption, ellipsis, quantifiers and scope, variable binding, ordering restrictions, pronominal distinctions, minimality violations, bare nouns and definiteness. It concludes that preverbal subjects in Brazilian Portuguese can be realized both in argumental positions (Specifier of the Inflectional or Tense Phrase) and non-argumental positions (Topic Phrase specifiers), with the possibility that both types of positions are filled by the subject in the same clause, incorporating properties that have been argued not to be found together in other languages.
Prostaglandin E2 Induces Matrix Metalloproteinase 9 Expression in Dendritic Cells through Two Independent Signaling Pathways Leading to Activator Protein 1 (AP-1) Activation

Dendritic Cells (DCs) play an important role in the initiation of the immune response by migrating to regional lymph nodes and presenting antigen processed at the inflammatory site to antigen-specific naive T cells. Prostaglandin E2 (PGE2) has been reported to play an essential role in DC migration. We reported previously that PGE2 induces matrix metalloproteinase 9 (MMP-9) expression in DCs and that PGE2-induced MMP-9 is required for DC migration in vivo and in vitro. In this study, we investigated the signaling mechanisms involved in PGE2-induced MMP-9 expression in DCs. We show that PGE2-induced MMP-9 expression is mediated primarily through the EP2/EP4 → cAMP → protein kinase A (PKA)/PI3K → ERK signaling pathway, leading to c-Fos expression, and through JNK-mediated activation of c-Jun in a PKA/PI3K/ERK-independent manner. EP2 and EP4 receptor agonists, as well as cAMP analogs, mimic the up-regulation of MMP-9 by PGE2. PKA, PI3K, and ERK inhibitors abolished PGE2- and cAMP-induced c-Fos and MMP-9 up-regulation, and ERK activation was required for the binding of activator protein 1 (AP-1) transcription factor to the MMP-9 promoter. Our results describe a new molecular mechanism for the effect of PGE2 on MMP-9 production in DCs that could lead to future therapeutic approaches using ERK inhibitors to regulate DC migration.
Characteristics of regions suspicious for pulmonary nodules at chest radiography

Rationale and Objectives. This study was performed to determine physical characteristics of areas on chest radiographs that are suspicious but not definitive for the presence of a pulmonary nodule and the characteristics of areas that contain an obvious nodule. Materials and Methods. Two groups of patients were identified: those who had an area at plain radiography that was suspicious for a pulmonary nodule and underwent fluoroscopy for further evaluation (138 patients, 142 areas) and those who had an obvious nodule at plain radiography who underwent computed tomography for further evaluation (72 patients, 97 areas). The measured characteristics of the region of interest included size, circularity, compactness, contrast, and location. Results. A comparison of the data show that while there was some difference between these groups of patients with regard to location of the nodules, there were essentially no differences with regard to size, circularity, compactness, and contrast of the regions of interest. Conclusion. Size, circularity, compactness, contrast, and location are not sufficient to distinguish pulmonary nodules from other suspicious regions on the chest radiograph.
Blending a Middle School Magnet Program for Gifted Students with A Regular Middle School Program

A gifted program can be a part of a regular school program without sacrificing excellence for the gifted students or lessening the quality of the regular school program. A gifted program that is planned for widespread effect can benefit all the students in a school, not just the identified gifted students.
Unified theory on the pathogenesis of Randall’s plaques and plugs

Kidney stones develop attached to sub-epithelial plaques of calcium phosphate (CaP) crystals (termed Randall’s plaque) and/or form as a result of occlusion of the openings of the Ducts of Bellini by stone-forming crystals (Randall’s plugs). These plaques and plugs eventually extrude into the urinary space, acting as a nidus for crystal overgrowth and stone formation. To better understand these regulatory mechanisms and the pathophysiology of idiopathic calcium stone disease, this review provides in-depth descriptions of the morphology and potential origins of these plaques and plugs, summarizes existing animal models of renal papillary interstitial deposits, and describes factors that are believed to regulate plaque formation and calcium overgrowth. Based on evidence provided within this review and from the vascular calcification literature, we propose a “unified” theory of plaque formation—one similar to pathological biomineralization observed elsewhere in the body. Abnormal urinary conditions (hypercalciuria, hyperoxaluria, and hypocitraturia), renal stress or trauma, and perhaps even the normal aging process lead to transformation of renal epithelial cells into an osteoblastic phenotype. With this de-differentiation comes an increased production of bone-specific proteins (i.e., osteopontin), a reduction in crystallization inhibitors (such as fetuin and matrix Gla protein), and creation of matrix vesicles, which support nucleation of CaP crystals. These small deposits promote aggregation and calcification of surrounding collagen. Mineralization continues by calcification of membranous cellular degradation products and other fibers until the plaque reaches the papillary epithelium. Through the activity of matrix metalloproteinases or perhaps by brute physical force produced by the large sub-epithelial crystalline mass, the surface is breached and further stone growth occurs by organic matrix-associated nucleation of CaOx or by the transformation of the outer layer of CaP crystals into CaOx crystals. Should this theory hold true, developing an understanding of the cellular mechanisms involved in progression of a small, basic interstitial plaque to that of an expanding, penetrating plaque could assist in the development of new therapies for stone prevention.
Regulation of hydrogenase biosynthesis by nickel in Bradyrhizobium japonicum

The addition of 5 μM nickel to heterotropically growing hydrogen uptake constitutive mutants resulted in up to a 10-fold increase in hydrogen uptake activity. Strain SR wild type cells required nickel for the derepression of hydrogenase in media treated to remove contaminating nickel and produced increasing levels of hydrogenase activity as a function of increasing nickel concentration. Immunoblots of SR wild type cultures derepressed with various concentrations of nickel revealed that the amount of anti-hydrogenase cross-reactive material synthesized is dependent on the amount of nickel in the media. Studies using chloramphenicol demonstrated that protein synthesis, in addition to nickel, was required for the synthesis of hydrogenase; inactive (nickel-free) hydrogenase protein does not accumulate during derepression in the absence of nickel. Thus the acquisition of hydrogenase activity by adding nickel during the course of derepression is not the result of nickel being inserted into pre-formed hydrogenase. Rifampicin inhibition studies suggested that nickel is required for the transcription of hydrogenase related genes. It is proposed that nickel, in addition to its structural role in the enzyme, plays a role in the regulation of hydrogenase expression in Bradyrhizobium japonicum.
Cited2 modulates TGF- β -mediated upregulation of MMP9

Cited (CBP/p300-interacting transactivators with glutamic acid (E)/aspartic acid (D)-rich C-terminal domain) 2, which is a CBP/p300-binding transcription co-activator without typical DNA-binding domains, has been implicated in control of cell growth and malignant transformation in Rat1 cells. In this report, we provide evidence that Cited2 is an important regulator of transforming growth factor (TGF)-β signaling. Overexpression of Cited2 enhanced TGF-β-mediated transcription of a Smad-Binding Element-containing luciferase reporter construct, SBE4-Luc. This may occur through a direct physical association of Cited2 with Smads 2 and 3, as supported by co-immunoprecipitation, mammalian two-hybrid and glutathione S-transferase-pull down assays. The transcription factor p300, which binds to Smad3, was shown to further enhance the interaction between Cited2 and Smad3, and the transcriptional responses of Smad3 by Cited2 in reporter assays. Cited2 enhances TGF-β-mediated upregulation of matrix metalloproteinase 9 (MMP9) in Cited2 inducible mouse embryo fibroblasts. Overexpression of Cited2 enhanced TGF-β-mediated MMP9 promoter reporter activity. Moreover, knockdown of Cited2 in MDA-MB-231 cells attenuated TGF-β-mediated upregulation of MMP9 and TGF-β-mediated cell invasion. Chromatin immunoprecipitation showed that Cited2 and Smad3 were recruited to MMP9 promoter upon TGF-β stimulation. This is the first demonstration that Cited2 functions as a Smad3/p300-interacting transcriptional co-activator in modulating the expression of MMP9, which could affect tumor cell invasion mediated by TGF-β.
Neurological, microscopic and enzyme-histochemical assessment of zinc pyrithione toxicity.

Abstract Male rats were given an ad lib. diet containing 250 ppm zinc pyrithione (ZPT) for 9 or 14 days and were then given untreated food during recovery. Each animal was matched to a pair-fed control. Clinical signs observed in all treated rats included progressive hind-limb weakness, motor incoordination, spinal kyphosis with muscle atrophy, and penile prolapse. Electrophysiological recording in vivo from purely sensory sural nerves showed a significant decrease in peak-to-peak potential amplitudes but no reduction in conduction velocity. The sensory nerve-evoked potential amplitudes remained significantly reduced after 4-wk recovery although no clinical signs of toxicity persisted. Similarly, recording in vitro from sections of the mixed sensory and motor sciatic nerves also showed significantly lower potential amplitudes with no reduction in nerve conduction velocity. Histological and enzyme-histochemical studies failed to reveal any abnormal muscle morphology. Light- and electron-microscopic examination of spinal roots, sciatic and sural nerves failed to reveal any pathological effects in the acutely affected rats. However, accumulations of dense granular axoplasmic deposits and accumulations of tubulo-vesicular profiles were noted in the axons of sural nerves and intramuscular lumbrical nerves. These studies and others recently completed (Sahenk & Mendell, J. Neuropath. exp. Neurol. 1979, in press) suggest an intracellular mechanism of ZPT toxicity involving axonal terminal structures. The distal concentration of membrane-associated proteins in treated animals is indicative of a fast axoplasmic transport neuropathy leading to defective maintenance of axon terminal structures and loss of function. Whether this is due to a specific enzyme deficiency, altered vitamin metabolism or some other biochemical process remains to be determined.
Mobile, High-Wind, Balloon-Launching Apparatus

In order to place instruments for measuring meteorological and electrical parameters into thunderstorms, an inexpensive apparatus has been developed which makes it possible to inflate, transport, and launch balloons in high winds. The launching apparatus is a cylinder of bubble plastic that is made by joining the sides of the cylinder together with a velcro rip strip. A balloon is launched by pulling the rip strip rapidly. This allows the balloon to pop upward into the ambient low-level wind and carry its instrumentation aloft. Different-sized launch tubes are constructed to accommodate particular sizes of balloons. Balloons have been launched in winds of about 20 m/s.
Characterization of foam cells in experimental atherosclerosis.

. A series of biochemical and morphological studies has focused on the properties and origins of lipid laden foam cells in experimentally induced atherosclerosis in rabbits. Lipid inclusions present in these cells occupy half or more of the cytoplasmic volume and are of two kinds: cytoplasmic lipid droplets composed predominantly of cholesteryl esters and lysosomes in which substantial quantities of free cholesterol have accumulated. The foam cells exhibit some properties of macrophages but not others. They possess high levels of acid hydrolases and catalase and Fc membrane receptors can be detected on their surface. Only about one third of the foam cells, however, exhibit C3 receptors and few if any of the cells appear to contain or to secrete lysozyme.
Sequential SNARE Assembly Underlies Priming and Triggering of Exocytosis

Changes in SNARE conformations during MgATP-dependent priming of cracked PC12 cells were probed by their altered accessibility to various inhibitors. Dominant negative soluble syntaxin and, to a much lesser extent, VAMP coil domains inhibited exocytosis more efficiently after priming. Neurotoxins and an anti-SNAP25 antibody inhibited exocytosis less effectively after priming. We propose that SNAREs partially and reversibly assemble during priming, and that the syntaxin H3 domain is prevented from fully joining the complex until the arrival of the Ca2+ trigger. Furthermore, we find that mutation of hydrophobic residues of the SNAP25 C-terminal coil that contribute to SNARE core interactions affects the maximal rate of exocytosis, while mutation of charged residues on the surface of the complex affects the apparent affinity of the coil domain for the partially assembled complex.
Higher Cerebrospinal Fluid MHPG in Subjects With Dementia of the Alzheimer Type: Relationship With Cognitive Dysfunction

The authors sought to determine the relationships between cerebrospinal fluid (CSF) levels of three neurotransmitter monoamine metabolites and cognitive function. CSF was collected from subjects with dementia of the Alzheimer's type ([DAT] n = 28) and control subjects (n = 10) for determination of CSF 5-hydroxyindole acetic acid (5-HIAA), 3-methoxy-4-hydroxy-phenylglycol (MHPG), and homovanillic acid (HVA) levels. All subjects underwent systematic assessment to determine cognitive function. Subjects with DAT had higher concentrations of CSF MHPG. In the overall sample, cognitive function was inversely correlated with CSF levels of MHPG but not with 5-HIAA or HVA. Within the DAT sample, these correlations did not achieve significance.
Altitude Dependence of the Longitudinal Distribution of Atmospheric Čerenkov Radiation

The longitudinal distribution of the Cherenkov radiation generated by the electron component of extensive cosmic ray air showers interacting with the earth's atmosphere is measured at -46 and 3801 m elevation. Although the two distributions are similar, a somewhat larger number of showers with small Cherenkov radiation thickness at 3801 m suggests that those showers contain substantial light contributions from elevations where electron scattering is small. (auth)
The effect of water vapor on fatigue crack tip stress and strain range distribution and the energy required for crack propagation in low-carbon steel

The formation of a subgrain structure by the passage of a fatigue crack in low-carbon steel has been detected by backscattered electron imaging in the SEM. The distribution of subgrain sizes has been measured as a function of cyclic stress intensity and environment, and from this data the cyclic stress and strain range distributions have been determined, as has the energy dissipated during propagation of the fatigue crack. These results are compared to theoretical and other experimental findings. The energy equivalent (per unit area of incremental crack advance) of the environment is found to be 106 times the surface energy of iron. In an inert environment, the maximum cyclic stress range developed at the crack tip is found to be approximately 2.3 times the yield stress, independent of cyclic stress intensity. Water vapor effectively lowers this stress range, and causes it to assume a dependence upon cyclic stress intensity.
Detoxification of aristolochic acid I by O‐demethylation: Less nephrotoxicity and genotoxicity of aristolochic acid Ia in rodents

Ingestion of aristolochic acids (AA) contained in herbal remedies results in aristolochic acid nephropathy (AAN), which is characterized by chronic renal failure, tubulointerstitial fibrosis and urothelial cancer. AA I and AA II, primary components in AA, have similar genotoxic potential, whereas only AA I shows severe renal toxicity in rodents. AA I is demethylated to form 8-hydroxy-aristolochic acid I (AA Ia) as a major metabolite. However, the nephrotoxicity and genotoxicity of AA Ia has not yet been determined. AA Ia was isolated from urine collected from rats treated with AA I and characterized by NMR and mass spectrometry. The purified AA Ia was administered intraperitoneally to C3H/He male mice for 9 days and its toxicity was compared with AA I. Using (32)P-postlabeling/polyacrylamide gel electrophoresis, the level of AA Ia-derived DNA adducts in renal cortex was approximately 70-110 times lower than that observed with AA I, indicating that AA Ia has only a limited genotoxicity. Supporting this result, when calf thymus DNA was reacted with AA Ia in a buffer containing zinc dust, the formation of AA Ia-DNA adducts was two-orders of magnitude lower than that of AA I. Histopathologic analysis revealed that unlike AA I, no significant changes were detected in the renal cortex of mice treated with AA Ia. Therefore, the contribution of AA Ia to renal toxicity is minimum. We conclude the metabolic pathway of converting AA I to AA Ia functions as the detoxification of AA I.
Global Imbalances and the Key Currency Regime: The Case for a Commodity Reserve Currency

This paper considers Kaldor's 1964 proposal for a commodity reserve currency (CRC) as a serious alternative to the current system, which has the US dollar as the world reserve currency. It argues that the reserve-currency status of the US dollar helped to create global imbalances and financial fragility pre-empting the current crisis. The primary goal of the CRC was to resolve the 1960 Triffin dilemma, which remains a problem today. Following a brief history of alternative monetary reform proposals, the CRC is outlined. Backed by a basket of 30 or so commodities, the CRC would fix their price index in terms of the international reserve and reduce the disorderly swings in individual commodity prices. Sovereign governments would be free to fix or float their national currencies to the CRC. With growing fears over global warming and national resource security, particularly in the world's poorest countries, the introduction of a CRC could reduce supply constraints, stabilize costs of production, promote globa...
Tissue buffering capacity: Its role in the prevention of isoproterenol induced necrosis

Abstract Rats treated for three weeks with Tris buffer showed an increased resistance to isoproterenol induced necrosis. Comparison of titration curves of heart homogenates from treated and control rats indicated an increased tissue buffering capacity of myocardial tissue after treatment.
Diffusion in several materials relevant to Cu interconnection technology

Knowledge of copper diffusion in conducting, dielectric and diffusion barrier thin films relevant to the upcoming Cu interconnection technology is important in order to understand electromigration and prevent degradation of the active devices in Si. Copper diffusion in several thin films considered essential for substitution of Al with Cu interconnects to reduce RC delays is discussed, and the available data are compiled. Fast diffusion of Cu has been observed through inorganic and organic dielectric films, so that the conducting Cu films will require encapsulation. Diffusion of Cu through CVD-W, TiAl3-0.5%Cu, TiCu and β-Ta diffusion barriers has also been studied in a comparative manner.
Particle-hole bound states in Mott-Hubbard insulators.

I present results that indicate the existence of strongly bound particle-hole excitations below the edge of the upper Hubbard band in a single-band, large-[ital U] Hubbard model in two dimensions, at half-filling. The appearance of these exciton states is due to correlation effects between a vacancy and a doubly occupied site induced by the antiferromagnetic background, in contrast to the conventional mechanism of exciton formation via long-range Coulomb attraction. I argue that in the insulating parent compounds of the high-temperature superconducting cuprates these correlation effects are of the same order of magnitude as particle-hole attraction due to longer-range Coulomb interactions.
Interoceptive “satiety” signals produced by leptin and CCK

The present studies assessed the extent to which the adiposity signal leptin and the brain-gut hormone cholecystokinin (CCK), administered alone or in combination, give rise to interoceptive sensory cues like those that are produced by a low (1 hr) level of food deprivation. Rats were trained with cues arising from1-hr and 24-hr food deprivation as discriminative stimuli. For one group, 24-hr food deprivation predicted the delivery of sucrose pellets, whereas 1-hr food deprivation did not. Another group received the reversed deprivation level-sucrose contingency. After asymptotic performance was achieved, the effects of leptin and CCK on food intake and on discrimination performance were tested under 24-hr food deprivation. In Experiment 1a, leptin administered into the third cerebroventricle (i3vt) at 3.5 or 7.0 μg doses had little effect, compared to saline on food intake or discriminative responding. In Experiment 1b, leptin (7.0 μg, i3vt) combined with CCK-8 (2 μg/kg, i.p.) reduced food intake significantly, but the findings indicated that CCK-8 alone produces interoceptive discriminative cues more like those produced by 1- than 24-hr food deprivation. Experiment 2a tested rats with i.p. leptin (0.3 and 0.5 mg/kg). Although neither dose suppressed intake, the 0.3 mg/kg dose produced interoceptive cues like 1-hr food deprivation. Experiment 2b tested two doses of CCK-8 (2 and 4mg/kg ,i.p.) and found significant intake suppression and generalization of discrimination with both doses of CCK-8. These findings suggest a role for both leptin and CCK in the production of sensory consequences that correspond to “satiety”.
The Use of Foreign Exchange Swaps by Central Banks

The paper discusses the use of foreign exchange swaps by central banks. Such use has aimed at affecting domestic liquidity, managing foreign exchange reserves, and stimulating domestic financial markets. The discussion is illustrated using selected countries. The paper cautions about the use of foreign exchange swaps to defend a particular exchange rate at a time when foreign exchange reserves are under pressure. It notes, finally, that use of foreign exchange swaps by central banks has been losing importance.
Sequence of retrovirus provirus resembles that of bacterial transposable elements

The nucleotide sequences of the terminal regions of an infectious integrated retrovirus cloned in the modified λ phage cloning vector Charon 4A have been elucidated. There is a 569-base pair direct repeat at both ends of the viral DNA. The cell–virus junctions at each end consist of a 5-base pair direct repeat of cell DNA next to a 3-base pair inverted repeat of viral DNA. This structure resembles that of a transposable element and is consistent with the protovirus hypothesis that retroviruses evolved from the cell genome.
Smart Money, Noise Trading and Stock Price Behaviour

This paper estimates an equilibrium model of stock price behaviour in which changes in exponentially de-trended dividends and prices are normally distributed and exogenous "noise traders" interact with "smart-money" investors who have constant absolute risk aversion. The model can explain the volatility and predictability of U.S. stock returns in the period 1871-1986 using either a low discount rate (4% or below) and a large constant risk discount on the stock price, or a higher discount rate (5% or above) and noise trading correlated with fundamentals. The data are not well able to distinguish between these explanations.