Search

Foraging honeybees (Apis mellifera) were trained individually to choose between 2 identical targets set close together on a large table in a heterogeneous surround. Discrimination was facilitated by the introduction of a small object that was nearer to 1 target than the other. It was also facilitated by the introduction of a longer object or a curved shield that was not differentially placed with respect to the targets but designed to encourage a fixed orientatio to them. The results support a distinction between place learning and position learning in honeybees.

High affinity attachment occurs between human immunodeficiency virus 1 (HIV-1) Tat protein and dipeptidyl aminopeptidase IV, CD26, a T-cell activation molecule. This Tat protein negatively regulates antigen-stimulated human T cell activity. The CD26 molecule, which contributes to recall antigen response, is found on CD4+ cell surfaces.

Abstract Background In 2006, a novel gammaretrovirus, XMRV (xenotropic murine leukemia virus-related virus), was discovered in some prostate tumors. A more recent study indicated that this infectious retrovirus can be detected in 67% of patients suffering from chronic fatigue syndrome (CFS), but only very few healthy controls (4%). However, several groups have published to date that they could not identify XMRV RNA or DNA sequences in other cohorts of CFS patients, while another group detected murine leukemia virus (MLV)-like sequences in 87% of such patients, but only 7% of healthy controls. Since there is a high degree of similarity between XMRV and abundant endogenous MLV proviruses, it is important to distinguish contaminating mouse sequences from true infections. Results DNA from the peripheral blood of 112 CFS patients and 36 healthy controls was tested for XMRV with two different PCR assays. A TaqMan qPCR assay specific for XMRV pol sequences was able to detect viral DNA from 2 XMRV-infected cells (~ 10-12 pg DNA) in up to 5 μg of human genomic DNA, but yielded negative results in the test of 600 ng genomic DNA from 100,000 peripheral blood cells of all samples tested. However, positive results were obtained with some of these samples, using a less specific nested PCR assay for a different XMRV sequence. DNA sequencing of the PCR products revealed a wide variety of virus-related sequences, some identical to those found in prostate cancer and CFS patients, others more closely related to known endogenous MLVs. However, all samples that tested positive for XMRV and/or MLV DNA were also positive for the highly abundant intracisternal A-type particle (IAP) long terminal repeat and most were positive for murine mitochondrial cytochrome oxidase sequences. No contamination was observed in any of the negative control samples, containing those with no DNA template, which were included in each assay. Conclusions Mouse cells contain upwards of 100 copies each of endogenous MLV DNA. Even much less than one cell's worth of DNA can yield a detectable product using highly sensitive PCR technology. It is, therefore, vital that contamination by mouse DNA be monitored with adequately sensitive assays in all samples tested.

This study explores the individual- and country-level factors that influence how getting news from social media relates to people's beliefs about anthropogenic climate change. Concepts of psychological distance and motivated reasoning are tested using multilevel analysis with survey data in 20 countries (N  = 18,785). Results suggest that using social media for news is associated with a decrease in climate skepticism across the sample. However, social context at the individual-level (conservative political ideology and low trust in science) and at the macro-level (high gross domestic product and individualism) moderate the effect, and therefore reduce social media's potential to inform the public about climate change. This study contributes to conversations about the ability of emerging media to address science issues, particularly in developing countries. [ABSTRACT FROM AUTHOR]

Today, people are exposed to vast information flows while online or on social media. This abundance has led some people to believe that they no longer have to actively seek the news to be well informed about public affairs and that important news will find them through social media or other online channels. Recently, academics have offered a first theoretical account, capturing this belief as the "news finds me" perception (NFM). Initial studies have been conducted in the U.S. and Austria, indicating deleterious effects between NFM and both traditional news use and political predispositions and behaviors. This study seeks to expand this line of research, exploring the proliferation of NFM in 10 societies around the world. Findings give further insights into the degree of NFM proliferation in diverse contexts. Across societies, NFM is associated with age, social media news use, and other meaningful democratic variables such as political interest, political knowledge, and voting behavior. [ABSTRACT FROM AUTHOR]

Since introduced by Professor McLeod and the Wisconsin School at the turn of the century, a large body of research has employed the communication mediation model. Yet, most of these studies rely on cross-sectional and individual-level survey data collected in the United States. This paper seeks to address these shortcomings by testing a specification of the model—the citizen communication mediation model—across cultures. Relying on panel survey data from 19 countries, this study advances a multilevel citizen communication mediation model. Our findings indicate that discussion remains a strong mediating predictor of political participation across countries and political contexts, though the relationship is moderated by macro-level repressive democratic expressive norms. [ABSTRACT FROM AUTHOR]