Origins of sinister rumors: A preference for threat-related material in the supply and demand of information

Many rumors convey information about potential danger, even when these dangers are very unlikely. In four studies, we examine whether micro-processes of cultural transmission explain the spread of threat-related information. Three studies using transmission chain protocols suggest a) that there is indeed a preference for the deliberate transmission of threat-related information over other material, b) that it is not caused by a general negativity or emotionality bias, and c) that it is not eliminated when threats are presented as very unlikely. A forced-choice study on similar material shows the same preference when participants have to select information to acquire rather than transmit. So the cultural success of threat-related material may be explained by transmission biases, rooted in evolved threat-detection and error-management systems, that affect both supply and demand of information.     

Experiences and attitudes towards dependence among students in Vukovar, Croatia

The sample consisted of 104 students (male and female) from Croatian town of Vukovar, which was heavily destroyed during the Homeland war in 1991. Through self-report, author researches their experiences and attitudes towards different dependences, from so-called light to so-called heavy dependences. The conclusions of the survey are as following: a) experiences of Vukovar' students differ a lot depending on potential danger of particular dependence, so students prefer so-called light dependences than so-called heavy dependences b) Vukovar' students attitudes towards noxiousness/ usefulness also differ according the potential danger of particular dependence and, again, so-called light dependences are more acceptable for students. c) Students have the same attitudes and experiences towards dependences, apart from gender or educational program. Suggesting the practical preventive usefulness, author stresses that basic conclusion of the survey is that students have positive attitude towards so-called light dependences, which should be changed by better information and education of students.     

An Unknown Determinant of a Sex-specific Altruism

Great tit (Parus major) males, when confronted with a source of danger that is either classifiable or inclassifiable and close to their brood, mob more than females. By staying near the source of danger longer, by mobbing it longer and more vigorously, and by approaching it more closely, males incur a greater risk than females do and therefore, appear to behave more altruistically. Since the only two accepted functional explanations, i.e. kin selection theory and self-estimation of reproductive value, fail to account for the extent and nature of this sexual difference, a new, as yet unknown determinant is postulated. It is conceivable that this cost factor operates in conjunction with self-estimation of reproductive value.     

Spatial Attention Effects of Disgusted and Fearful Faces

Effective processing of threat-related stimuli is of significant evolutionary advantage. Given the intricate relationship between attention and the neural processing of threat-related emotions, this study manipulated attention allocation and emotional categories of threat-related stimuli as independent factors and investigated the time course of spatial-attention-modulated processing of disgusting and fearful stimuli. The participants were instructed to direct their attention either to the two vertical or to the two horizontal locations, where two faces and two houses would be presented. The task was to respond regarding the physical identity of the two stimuli at cued locations. Event-related potentials (ERP) evidences were found to support a two-stage model of attention-modulated processing of threat-related emotions. In the early processing stage, disgusted faces evoked larger P1 component at right occipital region despite the attention allocation while larger N170 component was elicited by fearful faces at right occipito-temporal region only when participants attended to houses. In the late processing stage, the amplitudes of the parietal P3 component enhanced for both disgusted and fearful facial expressions only when the attention was focused on faces. According to the results, we propose that the temporal dynamics of the emotion-by-attention interaction consist of two stages. The early stage is characterized by quick and specialized neural encoding of disgusting and fearful stimuli irrespective of voluntary attention allocation, indicating an automatic detection and perception of threat-related emotions. The late stage is represented by attention-gated separation between threat-related stimuli and neutral stimuli; the similar ERP pattern evoked by disgusted and fearful faces suggests a more generalized processing of threat-related emotions via top-down attentional modulation, based on which the defensive behavior in response to threat events is largely facilitated.     

Protein-protein interactions: making sense of networks via graph-theoretic modeling

The emerging area of network biology is seeking to provide insights into organizational principles of life. However, despite significant collaborative efforts, there is still typically a weak link between biological and computational scientists and a lack of understanding of the research issues across the disciplines. This results in the use of simple computational techniques of limited potential that are incapable of explaining these complex data. Hence, the danger is that the community might begin to view the topological properties of network data as mere statistics, rather than rich sources of biological information. A further danger is that such views might result in the imposition of scientific doctrines, such as scale-free-centric (on the modeling side) and genome-centric (on the biological side) opinions onto this area. Here, we take a graph-theoretic perspective on protein-protein interaction networks and present a high-level overview of the area, commenting on possible challenges ahead.     

Decoding defensive systems

Our understanding of the neuronal circuits and mechanisms of defensive systems has been primarily dominated by studies focusing on the contribution of individual cells in the processing of threat-predictive cues, defensive responses, the extinction of such responses and the contextual modulation of threat-related behavior. These studies have been key in establishing threat-related circuits and mechanisms. Yet, they fall short in answering long-standing questions related to the integrative processing of distinct threatening cues, behavioral states induced by threat-related events, or the bridging from sensory processing of threat-related cues to specific defensive responses. Recent conceptual and technical developments has allowed the monitoring of large populations of neurons, which in addition to advanced analytic tools, have improved our understanding of how collective neuronal activity supports threat-related behaviors. In this review, we discuss the current knowledge of neuronal population codes within threat-related networks, in the context of aversive motivated behavior and the study of defensive systems.     

A predatory mechanism dramatically increases the efficiency of lateral gene transfer in Streptococcus pneumoniae and related commensal species

Bacteria that are competent for natural genetic transformation, such as pneumococci and their commensal relatives Streptococcus mitis and Streptococcus oralis , take up exogenous DNA and incorporate it into their genomes by homologous recombination. Traditionally, it has been assumed that genetic material leaking from dead bacteria constitutes the sole source of external DNA for competent streptococci. Here we describe a mechanism for active acquisition of homologous DNA that dramatically increases the efficiency of gene exchange between and within the streptococcal species mentioned above. This mechanism gives competent streptococci access to a common gene pool that is significantly larger than their own genomes, a property representing a considerable advantage when these bacteria are subjected to external selection pressures, such as vaccination and treatment with antibiotics.     

基于GIS的辽河干流饮用水源地生态安全演变趋势

在调查辽河干流饮用水源地生态安全隐患因素并进行生态安全状态评价的基础上,选取辽宁省境内辽河干流饮用水源地共59个县市区,运用安全风险评价理论,借助GIS格网赋值技术,完成饮用水源地的生态安全演变趋势评价.结果表明:生态安全高隐患区(安全得分≤0.3)有19个,安全状态恶化演变趋势较大;生态安全中等隐患区(0.3<安全得分≤0.7)有32个,安全状态恶化演变趋势不大;生态安全低隐患区(安全得分>0.7)有8个,安全状态恶化演变趋势较小.根据评价结果提出了相应的生态保护措施.     

Everyday contact spread of viral hepatitis B

The results obtained in the study of the characteristic features of the spread of viral hepatitis B under the conditions of family foci are presented. Children with viral hepatitis B have been found to infect 4-5 persons per 1,000 contacts, while adults infect not more than 1 person per 1,000 contacts. The results of the study have led to the conclusion that the idea of the potential danger of hepatitis B patients as the source of infection depends on the forms of the infectious process taken into account in evaluating its epidemiological significance. Latent cases of hepatitis B virus infection appear more frequently among the contacts of sick children than among those of sick adults, but the manifest forms of the disease are more frequently caused by infection contacted from sick adults.     

Social learning of fear and safety is determined by the demonstrator's racial group

Social learning offers an efficient route through which humans and other animals learn about potential dangers in the environment. Such learning inherently relies on the transmission of social information and should imply selectivity in what to learn from whom. Here, we conducted two observational learning experiments to assess how humans learn about danger and safety from members (‘demonstrators'') of an other social group than their own. We show that both fear and safety learning from a racial in-group demonstrator was more potent than learning from a racial out-group demonstrator.     

Flights of fear: a mechanical wing whistle sounds the alarm in a flocking bird

Animals often form groups to increase collective vigilance and allow early detection of predators, but this benefit of sociality relies on rapid transfer of information. Among birds, alarm calls are not present in all species, while other proposed mechanisms of information transfer are inefficient. We tested whether wing sounds can encode reliable information on danger. Individuals taking off in alarm fly more quickly or ascend more steeply, so may produce different sounds in alarmed than in routine flight, which then act as reliable cues of alarm, or honest ‘index’ signals in which a signal''s meaning is associated with its method of production. We show that crested pigeons, Ocyphaps lophotes, which have modified flight feathers, produce distinct wing ‘whistles’ in alarmed flight, and that individuals take off in alarm only after playback of alarmed whistles. Furthermore, amplitude-manipulated playbacks showed that response depends on whistle structure, such as tempo, not simply amplitude. We believe this is the first demonstration that flight noise can send information about alarm, and suggest that take-off noise could provide a cue of alarm in many flocking species, with feather modification evolving specifically to signal alarm in some. Similar reliable cues or index signals could occur in other animals.     

Relationship between Distance to Cover,Vigilance and Group Size in Staging Flocks of Semipalmated Sandpipers

Cover can be either a source of protection or a source of danger for foragers. Distance to cover creates a gradient in predation risk that allows examining adjustments in anti‐predator behaviour such as group size and vigilance. As distance to obstructive cover increases, both group size and vigilance are expected to decrease given that individuals have more time to react to a more distant source of danger. I provide an empirical test of these predictions in staging semipalmated sandpipers (Calidris pusilla) in a system controlling for many confounding factors that have marred earlier research. Controlling for food density, forager density and phenotypic attributes often correlated with distance to cover, I found that as distance to obstructive cover increased, sandpipers foraged in sparser groups, were less flighty and to some extent less vigilant. Such controlled studies are needed to re‐assess the relationship between distance to cover and anti‐predator behaviour.     

The Emerging Role of Cytoskeletal Proteins as Reliable Biomarkers

Cytoskeletal proteins are essential building blocks of cells. More than 100 cytoskeletal and cytoskeleton‐associated proteins are known and for some, their function and regulation are understood in great detail. Apart from cell shape and support, they facilitate many processes such as intracellular signaling and transport, and cancer related processes such as proliferation, migration, and invasion. During the last decade, comparative proteomic studies have identified cytoskeletal proteins as in vitro markers for tumor progression and metastasis. Here, these results are summarized and a number of unrelated studies are highlighted, identifying the same cytoskeletal proteins as potential biomarkers. These findings might indicate that the abundance of these potential markers of tumor progression is associated with the biological outcome and are independent of the cancer origin. This correlates well with recently published results from the Cancer Genome Atlas, indicating that cancers show remarkable similarities in their analyzed molecular information, independent of their organ of origin. It is postulated that the quantification of cytoskeletal proteins in healthy tissues, tumors, in adjacent tissues, and in stroma, is a great source of molecular information, which might not only be used to classify tumors, but more importantly to predict patients’ outcome or even best treatment choices.     

The debate over risk-related standards of competence

This discussion paper continues the debate over risk-related standards of mental competence which appears in Bioethics 5. Dan Brock there defends an approach to mental competence in patients which defines it as being relative to differing standards, more or less rigorous depending on the degree of risk involved in proposed treatments. But Mark Wicclair raises a problem for this approach: if significantly different levels of risk attach, respectively, to accepting and refusing the same treatment, then it is possible, on this account, for a patient to be considered competent to accept, but not refuse, the treatment, or vice versa. I argue that this puzzle does not constitute a genuine problem for a risk-related standard.
To this end I focus on the situation where, of two mutually exclusive options, one is riskier, but offering more pronounced benefit, while the other is safer, but offering less benefit. I argue for this proposition: it can take far less insight to know that the safe option is good than to know that the risky option is better. Now say one is actually informed enough to know that the safe option is good, but not enough to know whether the risky option is better; in such a case one is competent to say yes to that first option (the safe one), but not to say yes to the other. (I argue in passing that Pascal's Wager can be interpreted as having precisely this deliberative structure.)
I thus conclude that cases do indeed exist where one can be competent to say yes but not no, or vice versa; and that it is thus not an anomaly in the risk-related standard that it entails the existence of such cases.     

Avoidance of potentially harmful food cannot be socially transmitted between rats

The social transmission of food preferences(STFP) is a behavioural task of olfactory memory, in which an observer rat learns safe food odours from a demonstrator rat, and shows preference for this odour in a subsequent choice test. However, previous studies have failed to detect the transmission of information about food of potential danger and food aversion using STFP test. In this study, we tested how demonstrators' health affects the exchange of odour information and whether observers can learn danger information from an unhealthy demonstrator. As expected, the observer rat formed an odour preference after interacting with a demonstrator rat that had just eaten food containing a new odour, however, odour preference rather than aversion was also formed after interacting with a demonstrator rat injected with LiCl(used to induce gastric malaise). Furthermore, anaesthetized demonstrator rats and half-anaesthetized demonstrator rats, which showed obvious motor deficits suggesting an unhealthy state, also socially transmitted food preferences to observers. These results suggest that the social transmission of food preferences task is independent of a demonstrators' health, and that information about dangerous foods cannot be transmitted using this behavioural task.     

Effect of deer density on tick infestation of rodents and the hazard of tick-borne encephalitis. II: population and infection models

Tick-borne encephalitis is an emerging vector-borne zoonotic disease reported in several European and Asiatic countries with complex transmission routes that involve various vertebrate host species other than a tick vector. Understanding and quantifying the contribution of the different hosts involved in the TBE virus cycle is crucial in estimating the threshold conditions for virus emergence and spread. Some hosts, such as rodents, act both as feeding hosts for ticks and reservoirs of the infection. Other species, such as deer, provide important sources of blood for feeding ticks but they do not support TBE virus transmission, acting instead as dead-end (i.e., incompetent) hosts. Here, we introduce an eco-epidemiological model to explore the dynamics of tick populations and TBE virus infection in relation to the density of two key hosts. In particular, our aim is to validate and interpret in a robust theoretical framework the empirical findings regarding the effect of deer density on tick infestation on rodents and thus TBE virus occurrence from selected European foci. Model results show hump-shaped relationships between deer density and both feeding ticks on rodents and the basic reproduction number for TBE virus. This suggests that deer may act as tick amplifiers, but may also divert tick bites from competent hosts, thus diluting pathogen transmission. However, our model shows that the mechanism responsible for the dilution effect is more complex than the simple reduction of tick burden on competent hosts. Indeed, while the number of feeding ticks on rodents may increase with deer density, the proportion of blood meals on competent compared with incompetent hosts may decrease, triggering a decline in infection. As a consequence, using simply the number of ticks per rodent as a predictor of TBE transmission potential could be misleading if competent hosts share habitats with incompetent hosts.     

Bio-surfactants

Interest in microbially produced biosurfactants has increased recently, due mainly to their potential as agents in enhanced oil recovery. A variety of microbes and their products have been assessed for their surface-active properties, and it has been suggested that biosurfactants may prove useful in a broad spectrum of potential applications which presently utilise synthetic surfactants. The most commonly produced biosurfactants tend to be glycolipids, usually a mono- or di-saccharide attached to a fatty acid, but more complex molecules such as lipopeptides, lipoproteins, and lipo-heteropoly-saccharides have been isolated and studied. Biosurfactant production by microbes is often but not invariably enhanced by the addition of hydrocarbon to the growth medium, and needs to be optimised by controlling such factors as carbon source, nitrogen source and concentrations, aeration and metal ions. Biosurfactants have been shown to be as effective, if not more so, than many conventional synthetic surfactants and their future utilisation may depend utilimately upon the prevailing economics for their production.     

Incorporating functional inter-relationships into protein function prediction algorithms

Background  

Functional classification schemes (e.g. the Gene Ontology) that serve as the basis for annotation efforts in several organisms are often the source of gold standard information for computational efforts at supervised protein function prediction. While successful function prediction algorithms have been developed, few previous efforts have utilized more than the protein-to-functional class label information provided by such knowledge bases. For instance, the Gene Ontology not only captures protein annotations to a set of functional classes, but it also arranges these classes in a DAG-based hierarchy that captures rich inter-relationships between different classes. These inter-relationships present both opportunities, such as the potential for additional training examples for small classes from larger related classes, and challenges, such as a harder to learn distinction between similar GO terms, for standard classification-based approaches.     

Raised Middle-Finger: Electrocortical Correlates of Social Conditioning with Nonverbal Affective Gestures

Humans form impressions of others by associating persons (faces) with negative or positive social outcomes. This learning process has been referred to as social conditioning. In everyday life, affective nonverbal gestures may constitute important social signals cueing threat or safety, which therefore may support aforementioned learning processes. In conventional aversive conditioning, studies using electroencephalography to investigate visuocortical processing of visual stimuli paired with danger cues such as aversive noise have demonstrated facilitated processing and enhanced sensory gain in visual cortex. The present study aimed at extending this line of research to the field of social conditioning by pairing neutral face stimuli with affective nonverbal gestures. To this end, electro-cortical processing of faces serving as different conditioned stimuli was investigated in a differential social conditioning paradigm. Behavioral ratings and visually evoked steady-state potentials (ssVEP) were recorded in twenty healthy human participants, who underwent a differential conditioning procedure in which three neutral faces were paired with pictures of negative (raised middle finger), neutral (pointing), or positive (thumbs-up) gestures. As expected, faces associated with the aversive hand gesture (raised middle finger) elicited larger ssVEP amplitudes during conditioning. Moreover, theses faces were rated as to be more arousing and unpleasant. These results suggest that cortical engagement in response to faces aversively conditioned with nonverbal gestures is facilitated in order to establish persistent vigilance for social threat-related cues. This form of social conditioning allows to establish a predictive relationship between social stimuli and motivationally relevant outcomes.     

Chemical-based fecal source tracking methods: current status and guidelines for evaluation

Fecal source tracking is a rapidly evolving field for which there have been a number of method evaluation studies, workshops, review articles and a book that synthesize information about method efficacy. Chemicals that are specific to human wastewater offer several potential advantages over biologically based methods, but have received less scrutiny. More than 35 chemical analytes have been found to consistently occur in human waste streams and here we review these potential human-origin indicators in context of seven evaluation criteria. Some chemical methods offer advantages over microbial methods: they are generally faster to prepare and analyze, more source-specific because they are not confounded by regrowth in the environment, and some may be more geographically and temporally stable. However, they often require specialized equipment and are usually more expensive regarding sample preparation and analysis. Additionally, most chemicals that are specific to human waste-streams occur at concentrations low enough to be diluted below detection limits once the waste-stream enters the ambient environment. These two factors will likely result in chemical measures being used more often as cross-validation supplements or initial screening approaches, rather than replacements for microbial measures. Cross-validation supplements include several chemicals that are highly specific to human sources and can be important contributors when certainties about human sources are critical, such as in drinking water applications. At least one set of chemicals, fecal sterols and stanols, may have potential for identification of other sources in addition to humans. Of all the chemicals examined to date, optical brighteners (OBs) in detergents have shown considerable promise, especially for screening purposes. Optical brighteners are not as sensitive as most microbial assessments, but can be measured with a hand-held fluorometer, providing near real-time and relatively inexpensive tracking of signals in the field, if the human fecal source contains an OB concentration large enough to produce a measurable signal.