How disinformation operations against Russian opposition leader Alexei Navalny influence the international audience on Twitter.

Previous research dedicated a lot of effort to investigation of the activities of the Internet Research Agency, a Russia-based troll factory, as well as other information operations. However, those studies are mostly focused on the 2016 U.S. presidential election, Brexit, and other major international political events. In this study, we have attempted to analyze how narratives about a domestic issue in Russia are used by malicious actors to promote harmful discourses globally and persuade an international audience on Twitter. We have identified bot and troll activities related to the Twitter discussions of a Russian opposition leader Alexei Navalny using social network analysis and bot detection. We have also implemented the BEND framework to find persuasion maneuvers that are used by bots in conversations about Navalny and found attempts to manipulate the opinion of the international audience on Twitter. Our findings have demonstrated that there is a significant presence of bot activities in information operations against Alexei Navalny as one of the leaders of the Russian opposition. We have observed how the Russian domestic issue is framed in the context of Russian confrontation with the West and how it is used to promote hostile narratives either against Navalny, an opposition movement, or democratic values. Many agents that we have identified pretend to be English speakers, who exhibit hostile attitudes towards Navalny and the Western democracies, express skepticism and distort the facts, promote a lack of trust in the democratic institutions as well as spread disinformation and conspiracy theories.

Computational approaches to understanding interaction and development.

Audio-visual recording and location tracking produce enormous quantities of digital data with which researchers can document children's everyday interactions in naturalistic settings and assessment contexts. Machine learning and other computational approaches can produce replicable, automated measurements of these big behavioral data. The economies of scale afforded by repeated automated measurements offer a potent approach to investigating linkages between real-time behavior and developmental change. In our work, automated measurement of audio from child-worn recorders-which quantify the frequency of child and adult speech and index its phonemic complexity-are paired with ultrawide radio tracking of children's location and interpersonal orientation. Applications of objective measurement indicate the influence of adult behavior in both expert ratings of attachment behavior and ratings of autism severity, suggesting the role of dyadic factors in these "child" assessments. In the preschool classroom, location/orientation measures provide data-driven measures of children's social contact, fertile ground for vocal interactions. Both the velocity of children's movement toward one another and their social contact with one another evidence homophily: children with autism spectrum disorder, other developmental disabilities, and typically developing children were more likely to interact with children in the same group even in inclusive preschool classrooms designed to promote interchange between all children. In the vocal domain, the frequency of peer speech and the phonemic complexity of teacher speech predict the frequency and phonemic complexity of children's own speech over multiple timescales. Moreover, children's own speech predicts their assessed language abilities across disability groups, suggesting how everyday interactions facilitate development.

RNA Imaging with Multiplexed Error-Robust Fluorescence In Situ Hybridization (MERFISH).

Quantitative measurements of both the copy number and spatial distribution of large fractions of the transcriptome in single cells could revolutionize our understanding of a variety of cellular and tissue behaviors in both healthy and diseased states. Single-molecule fluorescence in situ hybridization (smFISH)-an approach where individual RNAs are labeled with fluorescent probes and imaged in their native cellular and tissue context-provides both the copy number and spatial context of RNAs but has been limited in the number of RNA species that can be measured simultaneously. Here, we describe multiplexed error-robust fluorescence in situ hybridization (MERFISH), a massively parallelized form of smFISH that can image and identify hundreds to thousands of different RNA species simultaneously with high accuracy in individual cells in their native spatial context. We provide detailed protocols on all aspects of MERFISH, including probe design, data collection, and data analysis to allow interested laboratories to perform MERFISH measurements themselves.

E2f3 in tumor macrophages promotes lung metastasis.

The Rb-E2F axis is an important pathway involved in cell-cycle control that is deregulated in a number of cancers. E2f transcription factors have distinct roles in the control of cell proliferation, cell survival and differentiation in a variety of tissues. We have previously shown that E2fs are important downstream targets of a CSF-1 signaling cascade involved in myeloid development. In cancer, tumor-associated macrophages (TAMs) are recruited to the tumor stroma in response to cytokines secreted by tumor cells, and are believed to facilitate tumor cell invasion and metastasis. Using the MMTV-Polyoma Middle T antigen (PyMT) mouse model of human ductal carcinoma, we show that the specific ablation of E2f3 in TAMs, but not in tumor epithelial cells, attenuates lung metastasis without affecting primary tumor growth. Histological analysis and gene expression profiling suggest that E2f3 does not impact the proliferation or survival of TAMs, but rather controls a novel gene expression signature associated with cytoskeleton rearrangements, cell migration and adhesion. This E2f3 TAM gene expression signature was sufficient to predict cancer recurrence and overall survival of estrogen receptor (ER)-positive breast cancer patients. Interestingly, we find that E2f3b but not E2f3a levels are elevated in TAMs from PyMT mammary glands relative to controls, suggesting a differential role for these isoforms in metastasis. In summary, these findings identify E2f3 as a key transcription factor in TAMs, which influences the tumor microenvironment and tumor cell metastasis.

Adverse physicochemical properties of tripalmitin in beta cells lead to morphological changes and lipotoxicity in vitro.

AIMS/HYPOTHESIS: Long-term exposure of beta cells to lipids, particularly saturated fatty acids in vitro, results in cellular dysfunction and apoptosis (lipotoxicity); this could contribute to obesity-related diabetes. Our aims were to relate cell death to intracellular triglyceride concentration, composition and localisation following incubation of INS1 cells in saturated and unsaturated NEFA in high and low glucose concentrations. MATERIALS AND METHODS: Insulin-producing INS1 cells were cultured (24 h; 3 and 20 mmol/l glucose) with palmitic, oleic or linoleic acids and the resulting intracellular lipids were analysed by gas chromatography and microscopy. Cell death was determined by quantitative microscopy and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and glucose-stimulated insulin secretion by ELISA. RESULTS: All NEFA (0.5 mmol/l, 0.5% albumin) inhibited glucose-stimulated (20 mmol/l) insulin secretion. Cytotoxicity was evident only with palmitic acid (p<0.05), in which case intracellular triglyceride consisted largely of tripalmitin in angular-shaped dilated endoplasmic reticulum. Cytotoxicity and morphological disruption were reduced by addition of unsaturated NEFA. Triglyceride content (control cells; 14.5 ng/mug protein) increased up to 10-fold following incubation in NEFA (oleic acid 153.2 ng/mug protein; p<0.05) and triglyceride and phospholipid fractions were both enriched with the specific fatty acid added to the medium (p<0.05). CONCLUSIONS/INTERPRETATION: In INS1 cells, palmitic acid is converted in the endoplasmic reticulum to solid tripalmitin (melting point >65 degrees C), which could induce endoplasmic reticulum stress proteins and signal apoptosis; lipid-induced apoptosis would therefore be a consequence of the physicochemical properties of these triglycerides. Since cellular triglycerides composed of single species of fatty acid are not likely to occur in vivo, destruction of beta cells by saturated fatty acids could be predominantly an in vitro scenario.

Fire ant venom alkaloid, isosolenopsin A, a potent and selective inhibitor of neuronal nitric oxide synthase.

Massive, multiple fire ant, Solenopsis invicta, stings are often treated aggressively, particularly in the elderly, despite limited evidence of systemic toxicity due to the venom. Over 95% of the S. invicta venom is composed of piperidine alkaloid components, whose toxicity, if any, is unknown. To assess a possible pharmacological basis for systemic toxicity, an alkaloid-rich, protein-free methanol extract of the venom from whole ants was assayed for inhibitory activity on the following nitric oxide synthase (NOS) isoforms, rat cerebellar neuronal (nNOS), bovine recombinant endothelial (eNOS), and murine recombinant immunologic (iNOS). Cytosolic NOS activity was determined by measuring the conversion of [(3)H]arginine to [(3)H]citrulline in vitro. Rat nNOS activity was inhibited significantly and in a concentration-dependent manner by the alkaloid-rich venom extract. For nNOS, enzyme activity was inhibited by approximately 50% with 0.33 +/- 0.06 microg of this venom extract, and over 95% inhibition of the three isoforms, nNOS, eNOS, and iNOS, was found with doses of 60 microg in 60 microl reaction mixture. These results indicate that the alkaloid components of S. invicta venom can produce potent inhibition of all three major NOS isoforms. Isosolenopsin A (cis-2-methyl-6-undecylpiperidine), a naturally occurring fire ant piperidine alkaloid, was synthesized and tested for inhibitory activity against the three NOS isoforms. Enzyme activities for nNOS and eNOS were over 95% inhibited with 1000 microM of isosolenopsin A, whereas the activity of iNOS was inhibited by only about 20% at the same concentration. The IC(50) for each of three NOS isoforms was approximately 18 +/- 3.9 microM for nNOS, 156 +/- 10 microM for eNOS, and >1000 microM for iNOS, respectively. Kinetic studies showed isosolenopsin A inhibition to be noncompetitive with L-arginine (K(i) = 19 +/- 2 microM). The potency of isosolenopsin A as an inhibitor of nNOS compares favorably with the inhibitory potency of widely used nNOS inhibitors. Inhibition of NOS isoforms by isosolenopsin A and structurally similar compounds may have toxicological significance with respect to adverse reactions to fire ant stings.

Apolipoprotein E genotype, islet amyloid deposition and severity of Type 2 diabetes.

Islet amyloid is found in 90% of patients with Type 2 (non-insulin-dependent) diabetes at post-mortem. More extensive amyloidosis is associated with decreased islet function and requirement for insulin therapy. Severity of cerebral amyloidosis in Alzheimer's disease (AD) is increased in subjects with the apolipoprotein E (ApoE) epsilon 4 allele. To determine if ApoE genotype was associated with severity of islet amyloidosis and diabetes, samples were genotyped from 32 specimens of post-mortem pancreas and from patients classified by disease progression. DNA was extracted from blood samples from Caucasian patients diagnosed with Type 2 diabetes, at age >40 years, classified according to disease progression: group 1 on oral therapy for at least 10 years from diagnosis, (n=147) and group 2, requiring insulin within 6 years from diagnosis, (n=187). ApoE genotype was determined by restriction-fragment length polymorphism analysis. DNA in pancreatic extracts (23 diabetic; 9 non-diabetic subjects) showed no association of ApoE polymorphisms with either degree of islet amyloidosis or disease severity. The distributions of ApoE epsilon 2, epsilon 3 and epsilon 4 were similar in both clinical patient groups and in the non-diabetic group and unrelated to progression of disease. It is unlikely that the common polymorphisms for the ApoE gene are linked to amyloid formation or progression of islet dysfunction in Type 2 diabetes.

Regulation of sympathetic nervous system function after cardiovascular deconditioning.

Humans subjected to prolonged periods of bed rest or microgravity undergo deconditioning of the cardiovascular system, characterized by resting tachycardia, reduced exercise capability, and a predisposition for orthostatic intolerance. These changes in cardiovascular function are likely due to a combination of factors, including changes in control of body fluid balance or cardiac alterations resulting in inadequate maintenance of stroke volume, altered arterial or venous vascular function, reduced activation of cardiovascular hormones, and diminished autonomic reflex function. There is evidence indicating a role for each of these mechanisms. Diminished reflex activation of the sympathetic nervous system and subsequent vasoconstriction appear to play an important role. Studies utilizing the hindlimb-unloaded (HU) rat, an animal model of deconditioning, evaluated the potential role of altered arterial baroreflex control of the sympathetic nervous system. These studies indicate that HU results in blunted baroreflex-mediated activation of both renal and lumbar sympathetic nerve activity in response to a hypotensive stimulus. HU rats are less able to maintain arterial pressure during hemorrhage, suggesting that diminished ability to increase sympathetic activity has functional consequences for the animal. Reflex control of vasopressin secretion appears to be enhanced following HU. Blunted baroreflex-mediated sympathoexcitation appears to involve altered central nervous system function. Baroreceptor afferent activity in response to changes in arterial pressure is unaltered in HU rats. However, increases in efferent sympathetic nerve activity for a given decrease in afferent input are blunted after HU. This altered central nervous system processing of baroreceptor inputs appears to involve an effect at the rostral ventrolateral medulla (RVLM). Specifically, it appears that tonic GABAA-mediated inhibition of the RVLM is enhanced after HU. Augmented inhibition apparently arises from sources other than the caudal ventrolateral medulla. If similar alterations in control of the sympathetic nervous system occur in humans in response to cardiovascular deconditioning, it is likely that they play an important role in the observed tendency for orthostatic intolerance. Combined with potential changes in vascular function, cardiac function, and hypovolemia, the predisposition for orthostatic intolerance following cardiovascular deconditioning would be markedly enhanced by blunted ability to reflexly activate the sympathetic nervous system.

Spontaneous resolution of profound hypogammaglobulinemia.

A 3-month-old, full-term female infant was hospitalized with pneumonia and bronchiolitis. Laboratory studies revealed a profoundly low level of IgG (41 mg/dL) and low level of IgA (< 6.67 mg/dL). Other causes of immunodeficiency were ruled out, and there was no evidence of protein loss to account for the low immunoglobulin levels. The immunoglobulin levels normalized over time. Our patient had a transient hypogammaglobulinemia of infancy, with severely low IgG and low IgA levels. We found no other reports of cases with such low values of IgG that proved to be transient.

Expanding habitat of the imported fire ant (Solenopsis invicta): a public health concern.

Residents in the southeastern United States would hardly describe life with the aggressive imported fire ant as peaceful coexistence. The continued spread of these insects has produced agricultural problems, changes in the ecosystem, and increasing numbers of subjects with sting sequelae, including hypersensitivity reactions, secondary infections, and rare neurologic sequelae. Evolutionary changes have facilitated their expansion northward into Virginia and westward into California, and increasing urbanization will likely permit further expansion. Recent reports of building invasion with sting attacks inside occupied dwellings, including health care facilities, heighten public health concerns. This article reviews the medically important entomology, clinical aspects of stings, and the current approaches to chemical control of fire ants. We also propose directions for future research and treatment.

Altered central nervous system processing of baroreceptor input following hindlimb unloading in rats.

The effect of cardiovascular deconditioning on central nervous system processing of baroreceptor afferent activity was evaluated following 14 days of hindlimb unloading (HU). Inactin-anesthetized rats were instrumented with catheters, renal sympathetic nerve electrodes, and aortic depressor nerve electrodes for measurement of mean arterial pressure, heart rate, renal sympathetic nerve activity (RSNA), and aortic depressor nerve activity (ADNA). Baroreceptor and baroreflex functions were assessed during infusion of phenylephrine and sodium nitroprusside. Central processing of baroreceptor afferent input was evaluated by linear regression relating RSNA to ADNA. The maximum baroreflex-elicited increase in RSNA was significantly reduced in HU rats (122 +/- 3.8 vs. 144 +/- 4.9% of baseline RSNA), whereas ADNA was not altered. The slope (-0.18 +/- 0.04 vs. -0.40 +/- 0.04) and y-intercept (121 +/- 3.2 vs. 146 +/- 4.3) of the linear regression relating increases in efferent RSNA to decreases in afferent ADNA during hypotension were significantly reduced in HU rats. There were no differences during increases in arterial pressure. Results demonstrate that the attenuation in baroreflex-mediated increases in RSNA following HU is due to changes in central processing of baroreceptor afferent information rather than aortic baroreceptor function.

Long-term outcome of infants at the margin of viability.

The outcome of babies at extremely short gestational age (22 to 26 weeks) effects our clinical decisions regarding their care. We looked at survival and presence of disability at 25 +/- 11 months of age in 246 of these infants born at our hospital between 1992 and 1996 who were average weight for gestational age. Babies were evaluated in our follow up clinic by a pediatrician, and a physical therapist for cerebral palsy, blindness and deafness, and by a psychologist with the Bayley II. Chances for survival without disability exceeded 50% of live born infants at 25 weeks gestation or a birth weight of 700 to 800 grams. Chances for survival exceeded 50% of live born infants at 24 weeks gestation or a birth weight of 600 to 700 grams. Chances for intact survival reached 50% of survivors at 23 weeks gestation or a birth weight of 400 to 500 grams.

Glutamate in the nucleus of the solitary tract activates both ionotropic and metabotropic glutamate receptors.

Glutamate is the proposed neurotransmitter of baroreceptor afferents at the level of the nucleus of the solitary tract (NTS). Blockade of ionotropic glutamate receptors with kynurenic acid blocks the arterial baroreflex but, paradoxically, does not abolish the response to exogenous glutamate. This study tested the hypothesis that exogenous glutamate in the NTS activates both ionotropic and metabotropic glutamate receptors (mGluRs). In urethan-anesthetized rats, unilateral microinjections of glutamate into the NTS decreased mean arterial pressure, heart rate, and lumbar sympathetic nerve activity. The cardiovascular response to injection of glutamate was not altered by NTS blockade of mGluRs with alpha-methyl-4-carboxyphenylglycine (MCPG). Blockade of ionotropic glutamate receptors with kynurenic acid attenuated the response to glutamate injection. After combined NTS injection of MCPG and kynurenic acid, the response to glutamate was blocked. These data suggest that exogenous glutamate microinjected into the NTS acts at both ionotropic glutamate receptors and mGluRs. In addition, blockade of both classes of glutamate receptors is required to block the cardiovascular response to microinjection of glutamate in the NTS.

Attenuated baroreflex control of sympathetic nerve activity after cardiovascular deconditioning in rats.

The effect of cardiovascular deconditioning on baroreflex control of the sympathetic nervous system was evaluated after 14 days of hindlimb unloading (HU) or the control condition. Rats were chronically instrumented with catheters and sympathetic nerve recording electrodes for measurement of mean arterial pressure (MAP) and heart rate (HR) and recording of lumbar (LSNA) or renal (RSNA) sympathetic nerve activity. Experiments were conducted 24 h after surgery, with the animals in a normal posture. Baroreflex function was assessed using a logistic function that related HR and LSNA or RSNA to MAP during infusion of phenylephrine and nitroprusside. Baroreflex influence on HR was not affected by HU. Maximum baroreflex-elicited LSNA was significantly reduced in HU rats (204 +/- 11.9 vs. 342 +/- 30.6% baseline LSNA), as was maximum reflex gain (-4.0 +/- 0.6 vs. -7.8 +/- 1.3 %LSNA/mmHg). Maximum baroreflex-elicited RSNA (259 +/- 10.8 vs. 453 +/- 28.0% baseline RSNA), minimum baroreflex-elicited RSNA (-2 +/- 2.8 vs. 13 +/- 4.5% baseline RSNA), and maximum gain (-5.8 +/- 0.5 vs. -13.6 +/- 3.1 %RSNA/mmHg) were significantly decreased in HU rats. Results demonstrate that baroreflex modulation of sympathetic nervous system activity is attenuated after cardiovascular deconditioning in rodents. Data suggest that alterations in the arterial baroreflex may contribute to orthostatic intolerance after a period of bedrest or spaceflight in humans.

Management of imported fire ant allergy: results of a survey.

BACKGROUND: Fire ant allergy is a significant health problem in the southern United States. Management of fire ant allergy is less clearly defined than management of allergy to the winged Hymenoptera. OBJECTIVE: To determine how fire ant allergy is managed by practicing allergists. METHODS: A survey form was developed and distributed to American College of Allergy, Asthma & Immunology members practicing in fire ant endemic states. Completed forms were returned to the American College of Allergy, Asthma & Immunology central office and forwarded to the authors for analysis. RESULTS: Three hundred twenty-nine of 879 (37.4%) surveys were returned; 81% of respondents have evaluated patients with imported fire ant allergy. Immunotherapy is used by 96.7% of respondents to treat fire ant allergy. A wide range of maintenance dosages are prescribed. Skin testing is the most common diagnostic method. Systemic reactions to stings while on maintenance immunotherapy were reported by 19%. Allergists utilize different criteria in consideration for stopping immunotherapy; 19% continue it indefinitely. CONCLUSIONS: There are many areas of general uniformity and other areas of divergence in how allergists manage imported fire ant allergy. These findings suggest continued need for further investigation regarding the efficacy, dosage, and duration of immunotherapy, as well as further elucidation of the natural history of fire ant allergy.

Candida endocarditis in a child with hyperimmunoglobulinemia E syndrome.

Hyperimmunoglobulin E syndrome (HIE) is a disorder characterized by extremely elevated serum levels of IgE and recurrent infections. Patients are particularly predisposed to have staphylococcal abscesses, usually involving skin, lungs, and joints; but they are also at risk for infections with other bacteria and fungi. We report the case of a 46-month-old boy with HIE who had Candida endocarditis and sepsis with a large fungal mass extending through the tricuspid valve and into the surrounding heart tissue, requiring surgical excision and replacement with a prosthetic valve. He had an indwelling central line for previous antibiotic therapy and had oral thrush for a month before presentation, which had been treated with oral nystatin. He was first seen with very dark urine, a new murmur, petechial rash, in shock, and disseminated intravascular coagulation. The white blood cell count was 38,700 with 70% segmented neutrophils, 9% banded neutrophils, 15% lymphocytes, 4% monocytes, and 2% eosinophils. Hemoglobin was 7.1, and platelet count was 14,000. Prothrombin time was 15.5, and partial thromboplastin time was 31; fibrinogen level was 110 mg/ml, and fibrin degradation products were greater than 40 mg/ml. Serum IgE was 38,664 and 44,510 on repeat measurement. He has had recurrent staphylococcal pneumonias with pneumatoceles, twice requiring segmental lung resection. Blood and tricuspid valve cultures grew Candida albicans. He was treated with amphotericin and flucytosine, and later switched to fluconazole, with good response to therapy. A literature search revealed no other reported case of Candida endocarditis in patients with HIE. Fungai endocarditis is a rare complication, which may occur in patients with HIE and indwelling central catheters.

Management of asthma in children.

Management of chronic asthma has changed significantly in recent years. Most of the changes in management are the result of an increased recognition of the importance of the inflammatory component in the pathogenesis and treatment of asthma. The National Heart, Lung, and Blood Institute issued guidelines for the management of asthma in 1991. Beta agonists, cromolyn and nedocromil are mainstays of treatment in patients with mild to moderate asthma. Inhaled steroids are useful in the treatment of patients with moderate to severe asthma. Nonpharmacologic management of asthma includes avoidance of allergens and irritants, the use of peak flow meters, and patient and family education.

Allergy to insect stings. A need for improved preventive management.

Allergy to insect venom is a major health problem for a significant number of people. Immunotherapy can reduce the risk of subsequent reaction from about 60% to less than 5%. Standard preventive care should include (1) advice concerning avoidance of insects, (2) prescription of an epinephrine kit or syringe for self-administration (unless medically contraindicated), and (3) referral for evaluation. Results of several studies from various regions of the country raise concern about the preventive care and advice given these patients and suggest a need for continuing medical education to improve preventive management of allergy to insect stings.