654 research outputs found

    Child Anxiety Sensitivity in Juvenile Adolescent Twins

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    Child Anxiety Sensitivity in Juvenile Adolescent Twins. Researched by Laura Hazlett from the VCU Psychology Department. Help from faculty mentors Dr. John Hettema, Psychiatry and Dr. Roxann Roberson-Nay, Psychology. Anxiety sensitivity (AS) is a dispositional trait where one is fearful of anxiety symptoms, and is distinguishable from the trait of anxiety itself. (Eke & McNally, 1996). These fears of anxiety-related sensations are an important factor in predicting the emergence and severity of panic symptoms (McNally, 2002). The Child Anxiety Sensitivity Index (CASI) is the child version of an 18-item self-report questionnaire commonly used to measure anxiety sensitivity. Zinbarg et al. (1997) demonstrated that the ASI has three first-order factors: Physical Concerns (i.e. “It scares me when my heart beats fast “), Mental Incapacitation Concerns (i.e. “When I am afraid, I worry that I might be crazy”), and Social Concerns (i.e. “Other kids can tell when I feel shaky “). The aim of the current study is to examine the relationship between scores on the CASI and responses during a low-dose carbon dioxide breathing task designed to induce panic-related sensations. The participants in our study were monozygotic and dizygotic twin pairs ranging from ages nine to thirteen. Twins’ responses throughout the task were measured using the Subjective Units of Distress Scale (SUDS) and the Diagnostic Symptom Questionnaire (DSQ), which measures cognitive and physical panic symptoms. We hypothesize that there is a positive relationship between the CASI and anxious responding during the carbon dioxide breathing task, such that as CASI scores increase, so do scores on the DSQ and SUDS. The results support the hypothesis and show significant evidence of a relationship between the CASI and subjectively experienced distress and panic symptoms. So, the more fearful an individual is of panic symptoms, the more severely they experience those symptoms, which in turn causes greater subjective distress. This study contributes to identifying the overall relationship between the CASI, DSQ, and SUDS scores when looking at physical, mental, and social concerns that contribute to the fear of experiencing subjective anxious symptoms.https://scholarscompass.vcu.edu/uresposters/1058/thumbnail.jp

    Subcutaneous Administration of D-Luciferin is an Effective Alternative to Intraperitoneal Injection in Bioluminescence Imaging of Xenograft Tumors in Nude Mice

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    Currently, intraperitoneal (IP) injection of D-luciferin is the preferred method of providing substrate for bioluminescence imaging (BLI); however it has a failure rate of 3–10% due to accidental intestinal injection. The present study evaluates the quality of BLI after subcutaneous (SC) injection of D-luciferin and demonstrates the effectiveness of SC injection in anatomically disparate tumor models. Mice bearing luciferase-expressing tumors underwent BLI after SC or IP injection of D-luciferin. The average time to maximal luminescence was 6 min (range 5–9 min) after SC injection and 8 min (range 5–8 min) after IP injection. Within 7 minutes of injection, SC and IP routes yielded similar luminescence in subcutaneous, intracranial, tongue, and lung xenograft tumor models. In a model of combined subcutaneous and intracranial xenografts, SC injection resulted in proportional luminescence at all sites, confirming that preferential delivery of substrate does not occur. While tumors were occasionally not visualized with IP injection, all tumors were visualized reliably with SC injection. Thus, SC injection of D-luciferin is a convenient and effective alternative to IP injection for BLI in nude mice. It may be a preferable approach, particularly for tumors with weaker signals and/or when greater precision is required

    “Never Say Never?”: Heterosexual, bisexual, and lesbian women’s accounts of being childfree

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    Feminist scholars have identified a “motherhood imperative” in Western cultures, where heterosexual women are understood to both want, and have, children. However, social shifts have resulted in a decrease in pronatalism as well as an increase in social recognition of the parenting desires of same-sex parents. Despite a resurgence of interest in childfree identities, research to date has predominantly focused on heterosexual women’s explanations for being childfree and their experiences of marginalisation. Our aim in the current study was to explore how childfree heterosexual, lesbian, bisexual, and queer women negotiate their childfree lives and identities in the context of their personal and social relationships within changing cultural contexts. Data from 23 interviews with women in the United Kingdom, who responded to a call for childfree participants, were thematically analysed. We constructed two themes: 1) Never say never? Negotiating being childfree as ever precarious, shows how women constructed being childfree as requiring constant revisiting and renegotiating to maintain; 2) An ordinary life: Constructing being childfree as rational and reasonable, in which we identify the rhetorical efforts of participants to establish their being childfree as an ordinary, reasonable, and rational position. We conclude that for these women, childfreedom was constantly in flux and that maintaining a positive childfree identity required considerable identity work in order to manage intimate personal relationships and wider friendships

    PNAS plus: plasmodium falciparum responds to amino acid starvation by entering into a hibernatory state

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    The human malaria parasite Plasmodium falciparum is auxotrophic for most amino acids. Its amino acid needs are met largely through the degradation of host erythrocyte hemoglobin; however the parasite must acquire isoleucine exogenously, because this amino acid is not present in adult human hemoglobin. We report that when isoleucine is withdrawn from the culture medium of intraerythrocytic P. falciparum, the parasite slows its metabolism and progresses through its developmental cycle at a reduced rate. Isoleucine-starved parasites remain viable for 72 h and resume rapid growth upon resupplementation. Protein degradation during starvation is important for maintenance of this hibernatory state. Microarray analysis of starved parasites revealed a 60% decrease in the rate of progression through the normal transcriptional program but no other apparent stress response. Plasmodium parasites do not possess a TOR nutrient-sensing pathway and have only a rudimentary amino acid starvation-sensing eukaryotic initiation factor 2α (eIF2α) stress response. Isoleucine deprivation results in GCN2-mediated phosphorylation of eIF2α, but kinase-knockout clones still are able to hibernate and recover, indicating that this pathway does not directly promote survival during isoleucine starvation. We conclude that P. falciparum, in the absence of canonical eukaryotic nutrient stress-response pathways, can cope with an inconsistent bloodstream amino acid supply by hibernating and waiting for more nutrient to be provided

    The Influence of Hypoxia and pH on Bioluminescence Imaging of Luciferase-Transfected Tumor Cells and Xenografts

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    Bioluminescence imaging (BLI) is a relatively new noninvasive technology used for quantitative assessment of tumor growth and therapeutic effect in living animal models. BLI involves the generation of light by luciferase-expressing cells following administration of the substrate luciferin in the presence of oxygen and ATP. In the present study, the effects of hypoxia, hypoperfusion, and pH on BLI signal (BLS) intensity were evaluated in vitro using cultured cells and in vivo using a xenograft model in nude mice. The intensity of the BLS was significantly reduced in the presence of acute and chronic hypoxia. Changes in cell density, viability, and pH also affected BLS. Although BLI is a convenient non-invasive tool for tumor assessment, these factors should be considered when interpreting BLS intensity, especially in solid tumors that could be hypoxic due to rapid growth, inadequate blood supply, and/or treatment

    Evidence That Hepatitis C Virus Resistance to Interferon Is Mediated through Repression of the PKR Protein Kinase by the Nonstructural 5A Protein

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    AbstractHepatitis C virus (HCV) is the major cause of non-A non-B hepatitis and a leading cause of liver dysfunction worldwide. While the current therapy for chronic HCV infection is parenteral administration of type 1 interferon (IFN), only a fraction of HCV-infected individuals completely respond to treatment. Previous studies have correlated the IFN sensitivity of strain HCV-1b with mutations within a discrete region of the viral nonstructural 5A protein (NS5A), termed the interferon sensitivity determining region (ISDR), suggesting that NS5A may contribute to the IFN-resistant phenotype of HCV. To determine the importance of HCV NS5A and the NS5A ISDR in mediating HCV IFN resistance, we tested whether the NS5A protein could regulate the IFN-induced protein kinase, PKR, a mediator of IFN-induced antiviral resistance and a target of viral and cellular inhibitors. Using multiple approaches, including biochemical, transfection, and yeast genetics analyses, we can now report that NS5A represses PKR through a direct interaction with the protein kinase catalytic domain and that both PKR repression and interaction requires the ISDR. Thus, inactivation of PKR may be one mechanism by which HCV avoids the antiviral effects of IFN. Finally, the inhibition of the PKR protein kinase by NS5A is the first described function for this HCV protein

    Genetics and the Archaeology of Ancient Israel

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    This paper is a call for DNA testing on ancient skeletal materials from the southern Levant to begin to database genetic information of the inhabitants of this crossroads region. Archaeologists and biblical historians view the earliest presence in the region of a group that called itself Israel in the Iron I period, traditionally dated to ca. 1200-1000 BCE. These were in villages in the varied hill countries of the region, contemporary with urban settlements in the coastal plains, inland valleys, and central Hill Country attributed to varied indigenous groups collectively called Canaanite. The remnants of Egyptian imperial presence in the region lasted until around 1150 BCE, postdating the arrival of an immigrant group from the Aegean called the Philistines ca. 1175 BCE. The period that follows the Iron I in the southern Levant is marked by the development of territorial states throughout the region, ca. 1000-800 BCE. These patrimonial kingdoms, including the United Kingdom of Israel and the divided kingdoms of northern Israel and Judah, coalesced varied peoples under central leadership and newly founded administrative and religious bureaucracies. Ancient DNA testing will give us a further refined understanding of the individuals who peopled the region of the southern Levant throughout its varied archaeological and historic periods, and put forward scientific data that will support, refute, or nuance our socio-historic reconstruction of ancient group identities. These social identities may or may not map onto genetic data, and without sampling of ancient DNA we may never know. A database of ancient DNA will also allow for comparisons with modern DNA samples collected throughout the greater region and the Mediterranean littoral, giving a more robust understanding of the long historical trajectories of regional human genetics and the genetics of varied ancestral groups of today’s Jewish populations and other cultural groups in the modern Middle East and Mediterranean
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