Miracle-dz/UniFAR-FTUs huggingface dataset:
Cyclooxygenase-2 (COX-2) Expression in Solid Pseudopapillary Tumor of the Pancreas: A Pilot Study

To the Editor: W e read with great interest the article by Bhandari et al recently published in Pancreas. They showed that galanin plays an important role in the pathogenesis of cerulein-induced pancreatitis. Acute pancreatitisYinduced hyperenzynemia in the plasma was approximately 50% to 60%, pancreatic myeloperoxidase activity was about 50%, and acinar cell necrosis was about 70% less in galanin gene knockout versus wild-type mice. In addition, administration of the galanin receptor antagonist, galantide, ameliorated acute pancreatitis. That exogenous galanin alone had no effect in wild-type mice with pancreatitis suggests that endogenous, but not exogenous, galanin exacerbates the disease. However, the mechanisms underlying the toxic effect of galanin during acute pancreatitis is unknown. It has been suggested that galanin can contribute to acute pancreatitis by decreasing pancreatic vascular perfusion, enhancing neurogenic inflammation, and inhibiting pancreatic enzyme secretion. We have shown earlier that galanin is a strong inhibitor of both endogenous and exogenous cholecystokininYstimulated pancreatic protein and volume secretion (20%Y30%) in vivo, whereas others have published that galanin inhibits ceruleininduced amylase secretion by 15% to 20% in vitro. However, it is almost completely forgotten that galanin inhibits basal pancreatic bicarbonate secretion in the innervated pancreas by approximately 90%. The data provided by Brodish et al8 suggest that in the innervated pancreas, galanin inhibits pancreatic ductal bicarbonate secretion much stronger than enzyme secretion (Fig. 1). However, in a chronic denervated pancreas model, the inhibitory effect of galanin was decreased by approximately 40%, suggesting an important role of neural factors on galanin-induced inhibition of pancreatic bicarbonate secretion. Galanin dose-dependently inhibited secretin-, cholecystokinin, and meal-induced bicarbonate outputs in both innervated and denervated pancreas. These data suggest that galanin inhibits bicarbonate secretion by different mechanisms such as inhibition of acetylcholine release from parasympathetic nerves and/or inhibition of insulin release from A cells and/or galanin release from sympathetic nerves. Furthermore, a direct effect of galanin on pancreatic ductal cells cannot be excluded. Taken together, the aforementioned data clearly suggest that galanin is a potent inhibitor of pancreatic ductal volume and bicarbonate secretion. Pancreatic ductal fluid and bicarbonate secretion have been shown to be crucially important for maintaining the integrity of the pancreas. The main function of this bicarbonate-rich isotonic solution is to transport digestive enzymes into the duodenum and to neutralize gastric acid. Of note, decreased ductal fluid secretion in patients with cystic fibrosis
The Effect of Maquiladora Employment on the Monthly Flow of Mexican Undocumented Immigration to the U.S., 1978–1982

Some controversy has surrounded the extent to which employment in maquiladoras (assembly plants located along the Mexican border) has stimulated undocumented immigration to the United States. This study uses monthly data of maquiladora employment and INS apprehensions in a “push-pull” migration framework to study the association between these two variables during the April 1978 to January 1982 period. The findings suggest that there is a significantly negative relationship between the one month lag of maquiladora employment and INS apprehensions. Employment growth in the maquiladora sector tends to be followed by a reduction of apprehensions one month later. The study also finds that male and female apprehensions appear to respond to relatively similar economic factors.
Modeling Two Types of Peace

A growing body of applied research on political violence employs split-population models to address problems of zero inflation in conflict event counts and related binary dependent variables. Nevertheless, conflict researchers typically use standard ordered probit models to study discrete ordered dependent variables characterized by excessive zeros (e.g., levels of conflict). This study familiarizes conflict scholars with a recently proposed split-population model—the zero-inflated ordered probit (ZiOP) model—that explicitly addresses the econometric challenges that researchers face when using a “zero-inflated” ordered dependent variable. We show that the ZiOP model provides more than an econometric fix: it provides substantively rich information about the heterogeneous pool of “peace” observations that exist in zero-inflated ordinal variables that measure violent conflict. We demonstrate the usefulness of the model through Monte Carlo experiments and replications of published work and also show that the substantive effects of covariates derived from the ZiOP model can reveal nonmonotonic relationships between these covariates and one’s conflict probabilities of interest.
Tunneling electroresistance in multiferroic heterostructures

We demonstrate the room temperature polar switching and tunneling in PbZr0.52Ti0. 48O3 (PZT) ultra-thin films of thickness 3–7 nm, sandwiched between platinum metal and ferromagnetic La0.67Sr0. 33MnO3 (LSMO) layers, which also shows magnetic field dependent tunnel current switching in Pt/PbZr0.52Ti0. 48O3/La0.67Sr0. 33MnO3 heterostructures. The epitaxial nature, surface quality and ferroelectric switching of heterostructured films were examined with the help of x-ray diffraction patterns, atomic force microscopy, and piezo force microscopy, respectively. The capacitance versus voltage graphs show butterfly loops above the coercive field (> ±3 V) of PZT for small probe area (∼16 μm2). The effect of ferroelectric switching was observed in current density versus voltage curves with a large variation in high-resistance/low-resistance (HRS/LRS) ratio (2:1 to 100:1), however, these effects were more prominent in the presence of in-plane external magnetic field. The conductance is fitted with Brinkman’s model, and the parabolic conductance upon bias voltage implies electron tunneling governs the transport.
The ε Subtype of Protein Kinase C Is Required for Cardiomyocyte Connexin-43 Phosphorylation

Abstract —Gap junctions (GJs), composed of connexins, are intercellular channels ensuring electric and metabolic coupling between cardiomyocytes. We have shown previously that an endogenous mitogenic and cardioprotective protein, fibroblast growth factor-2 (FGF-2), decreases cardiomyocyte GJ permeability by stimulating phosphorylation of connexin-43 (Cx43). Identifying the kinase(s) phosphorylating cardiac Cx43 may thus provide a way of modulating cardiac intercellular communication. Because FGF-2 activates receptors linked to protein kinase C (PKC) and mitogen-activated protein kinase, we first investigated participation of these enzymatic systems in Cx43 phosphorylation. The inhibitor PD98059 blocked activation of mitogen-activated protein kinase, but it did not prevent the FGF-2 effects on GJs. In contrast, the PKC inhibitor chelerythrine blocked the effects of FGF-2 on Cx43 phosphorylation and permeability. Because the e-isoform of PKC localizes to plasma membrane sites, we examined whether it is directly involved in the FGF-2–induced Cx43 phosphorylation. In nonstimulated myocytes, PKCe displayed a discontinuous pattern of localization at intercellular contact sites and partial colocalization with Cx43. Treatment with FGF-2 or phorbol 12-myristate 13-acetate induced a more continuous pattern of PKCe distribution, whereas the anti-Cx43 staining appeared to overlap extensively with that of PKCe. In immunoprecipitation experiments using specific anti-Cx43 antibodies, PKCe but not PKCα coprecipitated with Cx43. FGF-2 increased levels of coprecipitated PKCe, suggesting increased association between PKCe and Cx43 on stimulation. Transient gene transfer and overexpression of cDNAs coding for truncated or mutated dominant-negative forms of PKCe decreased cardiomyocyte Cx43 phosphorylation significantly. We conclude that PKC mediates the FGF-2–induced effects on cardiac GJs and that PKCe likely interacts with and phosphorylates cardiac Cx43 at sites of intercellular contact.
Molecular characterization of the clumping factor (fibrinogen receptor) of Staphylococcus aureus

Four mutants of Staphylococcus aureus strain Newman that were defective in the fibrinogen receptor (clumping factor) were isolated by transposon Tn917 mutagenesis. Southern hybridization analysis of the mutants identified transposon‐host DNA junction fragments, one of which was cloned and used to generate a probe to identify and clone the wild‐type clumping factor locus (clfA). The mutants failed to form clumps in soluble fibrinogen and adhered poorly to polymethylmethacrylate (PMMA) coverslips coated with fibrinogen. A single copy of the clfA gene, when introduced into the chromosome of the mutant strains, fuily compiemented the ciumping deficiency of these strains and restored the ability of these mutants to adhere to fibrinogen‐coated PMMA. in addition, the cloned clfA gene on a shuttle plasmid aiiowed the weakiy ciumping strain 8325‐4 to form clumps with the same avidity as the wild‐type strain Newman and also significantly enhanced the adherence of 8325‐4 strains. Thus the formation of clumps in soluble fibrinogen correlated with adherence of bacteria to solid‐phase fibrinogen. The clfA gene encodes a fibrinogen‐binding protein with an apparent molecular mass of c. 130 kDa. The amino acid sequence of the protein was deduced from the DNA sequence; it was predicted that a 896 residue protein (molecular mass 92 kDa) would be expressed. The putative ClfA protein has features that suggest that it is associated with the ceil surface. Furthermore it contains a novel 308 residue region comprising dipeptide repeats predominantly of Asp and Ser ending 28 residues upstream from the LPXTG motif common to wall‐associated proteins. Significant homology was found between the ClfA protein and the fibronectin‐binding proteins of S. S. aureus, particularly in the N‐and C‐termini.
Temporal changes in a Chihuahuan Desert rodent community

We used time series analysis of ten years of monthly census data to assess the responses of both individual species and an entire community of rodents to a fluctuating desert environment. Autocorrelation analysis revealed different patterns of intra-annual fluctuation among the It species: Dipodomys spectabilis and Perognathus Jarus had pronounced annual cycles: D. ordii, D. merriaini, Chaetodipus penicillutu~, Onvchomys torridus, 0. leucogusrer, and Neotoma alhigula exhibited annual cycles modified by interannual variation; and Feromyscus eremicus, Pm. maniculatus, and Reithrodontornys megalofis showed little evidence of annual periodicity. The timing af annual cycles and the pattern of inter-annual fluctuations also differed among species. However. two results suggest that several species responded similarly to long-term environmental variation: 1)population densities of four species and total rodent biomass and numbers were positively correlated with the densities of annual plants; and 2) many pairs of species exhibited positively correlated population dynamics over the ten years, Clustering of painvise cross-correlation coefficients was used to identify sets of species with similar population dynamics. These clusters did not necessarily contain closely related or ecologically similar species. Detrended Correspondence Analysis identified three independent patterns of variation in species composition: a long-term trend; a four- to five-year repeated pattern that appeared to correspond to the climatic effects of the El Nifio Southern Oscillation: and an annual cycle. In general. species appeared to respond individualistically to environmental variation. There was no evidence of an equilibrium community composition or of alternative stable configurations, Some competing species had negatively correlated population dynamics, but the majority of competitors exhibited positive correlations that apparently reflected similar responses to fluctuating resources.
FACTORS CONTRIBUTING TO THE SOIL SEED BANK SIZE OF TWO OBLIGATE SEEDING CEANOTHUS SPECIES IN NORTHERN CALIFORNIA

ABSTRACT In fire-prone vegetation, non-sprouting, obligate-seeding species depend on a persistent seed bank to reestablish post-fire populations. Thus, for such seeds, seed development and survival in the soil are critical life history stages. The objectives of our study were to examine the structure and composition of Ceanothus seed banks, analyze the viability of seeds in the soil, and determine rates of predation before and after seed dispersal. This study focused on populations of Ceanothus jepsonii var. albiflorus (J. Howell), which is restricted to serpentine soils. We also included data on Ceanothus cuneatus (Hook.) Nutt. , a widespread, non-restricted species, for comparison. We found that the seed bank of C. jepsonii loses seeds due to destruction or removal at several stages of development. Pre-dispersal seed predators attacked 37% of inflorescences included in experimentation and up to 50% of shrubs from which fruits were collected, post-dispersal predators removed over 70% of seeds in the litter. There was a 30% reduction in viability of older intact C. jepsonii seeds in the soil compared to seeds collected from plants during the study. A beetle in the genus Zabrotes, not previously known to oviposit on Ceanothus, was determined to be a causal agent of pre-dispersal seed predation, with other pre-dispersal predators and parasites also possible. These findings suggest that Ceanothus seed banks are quite dynamic and subject to a variety of seed losses during several stages prior to germination, which may ultimately be responsible for soil seed banks remaining relatively constant rather than building up over time.
β-Catenin induces T-cell transformation by promoting genomic instability

Significance Understanding molecular mechanisms that underlie genomic instability will remove a major obstacle to effective treatment of cancer. Here we characterize a unique animal model that allows insight into mechanisms of genomic instability leading to oncogenic translocations. We show that thymocyte-specific activation of β-catenin induces genomically unstable lymphomas with Tcra/Myc translocations, reminiscent of human leukemia. Tcf-1, the partner of β-catenin, colocalized throughout the genome with the RAG2 recombinase at DNA sites thought to be vulnerable to illegitimate recombination. Pretransformed thymocytes showed increased DNA damage at the translocating loci and altered DNA repair. These cells survived despite DNA damage. These surprising observations show that activated β-catenin promotes genomic instability and cancer by compromising DNA repair and enhancing cell survival. Deregulated activation of β-catenin in cancer has been correlated with genomic instability. During thymocyte development, β-catenin activates transcription in partnership with T-cell–specific transcription factor 1 (Tcf-1). We previously reported that targeted activation of β-catenin in thymocytes (CAT mice) induces lymphomas that depend on recombination activating gene (RAG) and myelocytomatosis oncogene (Myc) activities. Here we show that these lymphomas have recurring Tcra/Myc translocations that resulted from illegitimate RAG recombination events and resembled oncogenic translocations previously described in human T-ALL. We therefore used the CAT animal model to obtain mechanistic insights into the transformation process. ChIP-seq analysis uncovered a link between Tcf-1 and RAG2 showing that the two proteins shared binding sites marked by trimethylated histone-3 lysine-4 (H3K4me3) throughout the genome, including near the translocation sites. Pretransformed CAT thymocytes had increased DNA damage at the translocating loci and showed altered repair of RAG-induced DNA double strand breaks. These cells were able to survive despite DNA damage because activated β-catenin promoted an antiapoptosis gene expression profile. Thus, activated β-catenin promotes genomic instability that leads to T-cell lymphomas as a consequence of altered double strand break repair and increased survival of thymocytes with damaged DNA.
Effect of Secondary Electron Emission on Electron Cross-Field Current in $E \times B$ Discharges

This paper reviews and discusses recent experimental, theoretical, and numerical studies of plasma-wall interaction in a weakly collisional magnetized plasma bounded with channel walls made from different materials. A low-pressure E ×B plasma discharge of the Hall thruster was used to characterize the electron current across the magnetic field and its dependence on the applied voltage and the electron-induced secondary electron emission (SEE) from the channel wall. The presence of a depleted anisotropic electron energy distribution function with beams of secondary electrons was predicted to explain the enhancement of the electron cross-field current observed in experiments. Without the SEE, the electron cross-field transport can be reduced from anomalously high to nearly classical collisional level. The suppression of the SEE was achieved using an engineered carbon-velvet material for the channel walls. Both theoretically and experimentally, it is shown that the electron emission from the walls can limit the maximum achievable electric field in the magnetized plasma. With nonemitting walls, the maximum electric field in the thruster can approach a fundamental limit for a quasi-neutral plasma.
THE RELATIONSHIP BETWEEN SELF-ESTEEM AND ACHIEVEMENT MOTIVATION AMONG SUCCESSFUL AND UNSUCCESSFUL ATHLETES IN EAST AZARBAIJAN PROVINCE

Introduction : The aim of this study was to investigate the relationship between self-esteem and achievement motivation among successful and unsuccessful athletes in West Azerbaijan Province. Methods : Two-hundred athletes were divided into two groups of successful athletes (n=100, 50 males and 50 females) and unsuccessful athletes (n=100, 50 males and 50 females) while the term «successful» means that the subject has win medals at national and international official competitions and «unsuccessful» means he/she has not been able to do so. Gill and Deter's sport orientation scale (SOQ) (1998) and revised self-esteem questionnaire (Cupper-Smith, 1968) were the assessment instruments used in this study. Pearson Correlation and t-test (α<0.05) were applied for the statistical analysis of data. Results : The results showed that there is a significant correlation between self-esteem and achievement motivation in both studied groups. Moreover, successful and unsuccessful athletes significantly differed in terms of self-esteem and achievement motivation so that self-esteem and achievement motivation were significantly higher in successful athletes compared to unsuccessful athletes. Conclusion : It seems that athletes’ beliefs interfere with their performance. Therefore equal attention must be paid to fitness and sport skills and motivational variables through appropriate physical education and providing conditions in which athletes feel competence and motivation and experience success. Coaches are advised to provide timely feedback, necessary support and constructive criticism in order to give their students the opportunity to be aware of their capabilities and increase their achievement motivation accordingly. Keywords: self-esteem, achievement motivation, successful athletes , unsuccessful athletes
Differential induction and repair of ultraviolet damage leading to true revesions and external suppressor mutations of an ochre codon in Escherichia coli B-r WP2.

UCH of the published work on the mechanisms by which radiation-induced lesions result in genetic mutations in bacteria has involved the reversion to prototrophy of amino-acid requiring strains, in particular the tryptophan auxotroph Escherichia coli B/r WP2 isolated by WITKIN. It has been realised for some time that mutant prototrophs are not all true reversions to ‘wild type. HILL (1963), for example, foiund that some spontaneous and ultraviolet-induced prototrophs of B/r WP2 grew more slowly and were unstable. She suggested that they might be suppressor mutants. WITKIN (1963) also gave evidence that suppressor mutations, capable of cvvercoming at a single step auxotrophies at several loci, were induced by ultraviolet light (UV) under certain conditions. Unfortunately the difficulty in performing genetic analysis in the B family of E. coli has hitherto precluded a study of the involvement of true reversion and suppressor mutation in the several phenomena associated with radiation mutagenesis. Recently BRIDGES, DENNIS and PVIuNsoN (1967) showed that many prototrophs derived from B/r WP2 contain’ed suppressors capable of suppressing chain terminating codons in T4 phage, and a simple way of distinguishing suppressor mutants from true revertants was described. (Chain terminating codons UGA, UAG (“amber”) and UAA (“ochre”) appear to code for no amino acid and thus prevent the assembly of the polypeptide chain beyond the point at which they are situated in the messenger RNA. ) In this paper we show that the suppressors in B/r WP2 are all ochre suppressors from which we infer thLat the parent B/r WP2 has an ochre (UAA) codon at a tryptophan locus. A sindar conclusion has been drawn by OSBORN and PERSON (1967). We also investigate the induction of true and suppressor mutations by UV under different conditions, and compare their relative susceptibility to various processes which have been described for the removal (or bypassing) of genetic damage.
Are Auditory-Evoked Frequency and Duration Mismatch Negativity (MMN) Deficits Endophenotypic for Schizophrenia? High-Density Electrical Mapping in Clinically Unaffected First-Degree Relatives, First-Episode and Chronic Schizophrenia.

Background— Mismatch negativity (MMN) is a negative-going event-related potential (ERP) component that occurs in response to intermittent changes in constant auditory backgrounds. A consistent finding across a large number of studies has been impaired MMN generation in schizophrenia, which has been interpreted as evidence for fundamental deficits in automatic auditory sensory processing. The aim of this study was to investigate the extent to which dysfunction in MMN generation might represent an endophenotypic marker for schizophrenia. Methods— We measured MMN to deviants in duration (25 msec, 1000Hz) and deviants in pitch (50 msec, 1200Hz) relative to standard tones (50 msec, 1000Hz) in 45 chronic schizophrenia patients, 25 of their first-degree unaffected biological relatives, 12 first-episode patients, and 27 healthy control subjects. Results— In line with previous work, MMN amplitudes to duration deviants (but not to pitch deviants) were significantly reduced in patients with chronic schizophrenia compared to control subjects. However, both duration and pitch MMNs were completely Conclusions— These findings suggest that the MMN deficit seen in schizophrenia patients is most likely a consequence of the disease and that MMN, at least to basic auditory feature deviants, is at best only weakly endophenotypic for schizophrenia.
p57kip2 is useful in the classification and differential diagnosis of complete and partial hydatidiform moles

Aims: To determine the utility of p57kip2 in the diagnosis of hydatidiform mole. p57kip2 protein is a cyclin‐dependent kinase inhibitor (CDKI) and is strongly paternally imprinted, being expressed from the maternal allele. It has been hypothesized that complete mole (CHM) with only the paternal genome would display reduced or nearly absent expression of p57kip2 compared to partial mole (PHM) having both paternal and maternal genomes.