1,121 research outputs found

    Mothers influence offspring body size through post-oviposition maternal effects in the redbacked salamander, Plethodon cinereus

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    In the terrestrial salamander ( Plethodon cinereus ), previous work has shown that mother’s body size is positively correlated to offspring size at the time of hatching even after controlling for the effects of egg size. This study was designed to determine whether maternal body size affects offspring size via pre-oviposition factors (e.g., yolk quality, jelly coat composition, or maternal genes) or post-oviposition factors (e.g., parental care behaviors, parental modification of environment). Gravid females were captured and induced to lay eggs in experimental chambers in which the environment was standardized. Fifteen clutches were exchanged, or cross-fostered, between female pairs differing in body size. Ten females whose eggs were taken away and then returned served as controls for the crossing treatment. Foster mothers did not significantly differ from control mothers in the time spent with eggs, body position, or number of egg movements during brooding. Average egg mass measured midway through development was not significantly correlated to the body size of either the genetic or foster mother, but was correlated to pre-oviposition oocyte size. At hatching, offspring body length was positively correlated to egg size and the foster mother’s body size. This correlation suggests that in P. cinereus post-oviposition maternal effects have a greater impact on offspring size than other maternal factors incorporated into the egg prior to oviposition. While our study showed that larger mothers moved their eggs less often and tended to spend more time in contact with their eggs, further work needs to be done to identify the specific mechanisms through which larger mothers influence the body size of their offspring. This is the first experimental demonstration of post-oviposition maternal effects for any amphibian with parental care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47699/1/442_2003_Article_1410.pd

    Tsunami 2004

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    The Tsunami after the sea quake in Southeast Asia at the 26th of December 2004 represents one of the largest disasters in the modern World. Approximately 228,000 people from the countries surrounding the Indian Ocean have died. A large number of visitors from different European countries staying for their Christmas holidays in Thailand and Sri Lanka became victims of the natural disaster. The large number of foreign victims in these countries required additional forensic investigations which were organized by internationally working DVI (Disaster Victim Identification) teams. Victim identification was a great challenge due to the environmental conditions rapidly leading to heavily decomposed bodies. Thus the forensic medical investigations were very important to identify the victims. The different steps of forensic medical, odonto-stomatological and molecular genetic investigations beginning at the end of 2004 with the identification of a small number of victims and ending with the closing of the TTVI IMC (Thai Tsunami Victim Identification Information Management Center) in Phuket one year later are described and critically discussed. Up to 31 international DVI Teams worked in the TTVI IMC during 2005

    Revealing the origin of the vertical hysteresis loop shifts in an exchange biased Co/YMnO3_3 bilayer

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    We have investigated exchange bias effects in bilayers composed by the antiferromagnetic o-YMnO3_3 and ferromagnetic Co thin film by means of SQUID magnetometry, magnetoresistance, anisotropic magnetoresistance and planar Hall effect. The magnetization and magnetotransport properties show pronounced asymmetries in the field and magnetization axes of the field hysteresis loops. Both exchange bias parameters, the exchange bias field HE(T)H_{E}(T) as well as the magnetization shift ME(T)M_E(T), vanish around the N\'eel temperature TN45T_N \simeq 45 K. We show that the magnetization shift ME(T)M_E(T) is also measured by a shift in the anisotropic magnetoresistance and planar Hall resistance having those a similar temperature dependence as the one obtained from magnetization measurements. Because the o-YMnO3_3 film is highly insulating, our results demonstrate that the ME(T)M_E(T) shift originates at the interface within the ferromagnetic Co layer. To show that the main results obtained are general and not because of some special characteristics of the o-YMO3_3 layer, similar measurements were done in Co/CoO micro-wires. The transport and magnetization characterization of the micro-wires supports the main conclusion that these effects are related to the response of the ferromagnetic Co layer at the interface.Comment: 16 Figures, in press at J. Phys.: Condensed Matter 201

    Architectures of control in consumer product design

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    Copyright @ 2005 Social Services Research GroupThe idea of architectures of control is introduced through examples ranging from urban planning to digital rights management, and the intentions behind their use in consumer products are examined, with reference to case studies of printer cartridges and proposed 'optimum lifetime products.' The reactions of the technical community and consumers themselves are also explored, along with some wider implications for society

    Creating the collective: social media, the Occupy Movement and its constitution as a collective actor

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    This paper examines the process through which Occupy activists came to constitute themselves as a collective actor and the role of social media in this process. The theoretical framework combines Melucci's (1996) theory of collective identity with insights from the field of organizational communication and particularly from the ‘CCO’ strand – short for ‘Communication is Constitutive of Organizing’. This allows us to conceptualize collective identity as an open-ended and dynamic process that is constructed in conversations and codified in texts. Based on interviews with Occupy activists in New York, London and other cities, I then discuss the communication processes through which the movement was drawing the boundaries with its environment, creating codes and foundational documents, as well as speaking in a collective voice. The findings show that social media tended to blur the boundaries between the inside and the outside of the movement in a way that suited its values of inclusiveness and direct participation. Social media users could also follow remotely the meetings of the general assembly where the foundational documents were ratified, but their voices were not included in the process. The presence of the movement on social media also led to conflicts and negotiations around Occupy's collective voice as constructed on these platforms. Thus, viewing the movement as a phenomenon emerging in communication allows us an insight into the efforts of Occupy activists to create a collective that was both inclusive of the 99% and a distinctive actor with its own identity

    Distilling Privacy Requirements for Mobile Applications

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    As mobile computing applications have become commonplace, it is increasingly important for them to address end-users’ privacy requirements. Privacy requirements depend on a number of contextual socio-cultural factors to which mobility adds another level of contextual variation. However, traditional requirements elicitation methods do not sufficiently account for contextual factors and therefore cannot be used effectively to represent and analyse the privacy requirements of mobile end users. On the other hand, methods that do investigate contextual factors tend to produce data that does not lend itself to the process of requirements extraction. To address this problem we have developed a Privacy Requirements Distillation approach that employs a problem analysis framework to extract and refine privacy requirements for mobile applications from raw data gathered through empirical studies involving end users. Our approach introduces privacy facets that capture patterns of privacy concerns which are matched against the raw data. We demonstrate and evaluate our approach using qualitative data from an empirical study of a mobile social networking application

    Net neutrality discourses: comparing advocacy and regulatory arguments in the United States and the United Kingdom

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    Telecommunications policy issues rarely make news, much less mobilize thousands of people. Yet this has been occurring in the United States around efforts to introduce "Net neutrality" regulation. A similar grassroots mobilization has not developed in the United Kingdom or elsewhere in Europe. We develop a comparative analysis of U.S. and UK Net neutrality debates with an eye toward identifying the arguments for and against regulation, how those arguments differ between the countries, and what the implications of those differences are for the Internet. Drawing on mass media, advocacy, and regulatory discourses, we find that local regulatory precedents as well as cultural factors contribute to both agenda setting and framing of Net neutrality. The differences between national discourses provide a way to understand both the structural differences between regulatory cultures and the substantive differences between policy interpretations, both of which must be reconciled for the Internet to continue to thrive as a global medium

    Net neutrality discourses: comparing advocacy and regulatory arguments in the United States and the United Kingdom

    Get PDF
    Telecommunications policy issues rarely make news, much less mobilize thousands of people. Yet this has been occurring in the United States around efforts to introduce "Net neutrality" regulation. A similar grassroots mobilization has not developed in the United Kingdom or elsewhere in Europe. We develop a comparative analysis of U.S. and UK Net neutrality debates with an eye toward identifying the arguments for and against regulation, how those arguments differ between the countries, and what the implications of those differences are for the Internet. Drawing on mass media, advocacy, and regulatory discourses, we find that local regulatory precedents as well as cultural factors contribute to both agenda setting and framing of Net neutrality. The differences between national discourses provide a way to understand both the structural differences between regulatory cultures and the substantive differences between policy interpretations, both of which must be reconciled for the Internet to continue to thrive as a global medium
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