Search results for "Spring"
showing 10 items of 600 documents
Infanticide and effectiveness of pup protection in bank voles: does the mother recognise a killer?
2002
Infanticide, the killing of conspecific young, has been documented in numerous species of mammals, especially rodents. In that infanticide is costly to the victim mother, natural selection should favour counter-strategies by females to protect their pups. We studied the frequency of infanticide by male and female bank voles (Clethrionomys glareolus) and the effectiveness of dams in recognising and deterring infanticide. In trials in which unprotected pups were exposed to voles of both sexes, one third of male and female intruders killed pups. When mothers were present at the nest site, not a single female and only 2 of 25 males were able to commit infanticide. Females acted aggressively tow…
Do female leaf beetles Galerucella nymphaeae choose their mates and does it matter?
1998
The role of active female choice in sexual selection is frequently difficult to ascertain, and this is particularly the case for many insect species. Also, it is uncertain whether choosing between males would affect offspring viability. We designed an experiment to investigate the presence of female choice in a Coleoptera species (Galerucella nymphaeae). We also estimated whether mate choice would have any effect on offspring performance. Females were first placed with two males in a test arena to see which of the males copulated with the virgin female, and how quickly. Subsequently the loser male was offered a new virgin female to test for any change in latency time until mating. The two-m…
Influence of male mating history on female reproductive success among monandrous Naryciinae (Lepidoptera: Psychidae)
2011
1. Multiple male copulations can have detrimental effects on female fitness due to sperm limitation. 2. Monandrous Naryciinae females are immobile while the males are short-lived and do not feed. Multiple male mating is therefore expected to lead to sperm limitation in females. Sperm limitation and male limitation are hypothesised as causes of the repeated evolution of parthenogenetic reproduction in the Psychidae. 3. In this study, the effects of multiple male mating on female reproduction are investigated in several species of Naryciinae by allowing males multiple copulations. The results for two species, Siederia listerella and Dahlica lichenella, are compared. The sex ratios of 53 natur…
A microeconometric analysis of the springboard subsidiary: The case of Spanish firms
2015
Abstract This paper provides a microeconometric analysis of the distinctive characteristics of springboard subsidiaries that have a positive impact on the subsidiaries’ performance. Based on panel data estimations for subsidiaries of European multinational companies with a presence in Spain, the authors found that if the subsidiary is located in the springboard country, then the performance improvement (increase in profit margin) of the subsidiary is about 49 percentage points. When the Spanish subsidiary is considered a springboard subsidiary, its performance is 7.7 percentage points higher than the performance of other subsidiaries that are not springboard subsidiaries. If the subsidiary …
Applying Spring Security Framework with KeyCloak-Based OAuth2 to Protect Microservice Architecture APIs: A Case Study
2022
In this study, we implemented an integrated security solution with Spring Security and Keycloak open-access platform (SSK) to secure data collection and exchange over microservice architecture application programming interfaces (APIs). The adopted solution implemented the following security features: open authorization, multi-factor authentication, identity brokering, and user management to safeguard microservice APIs. Then, we extended the security solution with a virtual private network (VPN), Blowfish and crypt (Bcrypt) hash, encryption method, API key, network firewall, and secure socket layer (SSL) to build up a digital infrastructure. To accomplish and describe the adopted SSK solutio…
High cognitive sensitivity to activational effects of testosterone in parents of offspring with autism spectrum disorders
2014
Abstract The existence of mild forms of autistic-like characteristics in parents of children with autism spectrum disorders (ASDs) has been defined as a broader autistic phenotype (BAP). Excessive prenatal exposure to testosterone (T) seems to play a role in its development. The aims of this study were to characterize whether ASD parents show masculinized brains or high T prenatal exposure compared to a normative population, using cognitive questionnaires, and also to examine the T level changes in response to different cognitive tasks. ASD parents were found to present higher autistic and lower empathic trait scores than controls. They also have higher T levels and magnitude of T response …
Evidence for a teratogenic risk in the offspring of health personnel exposed to ionizing radiation?!
2016
Background The evidence concerning safety of occupational exposure to ionizing radiation on teratogenic effects mainly relies on animal models, disaster epidemiology and experience in cancer etiology. Following an explorative result on maternal exposure in medical occupations we conducted a feasibility study, addressing congenital anomalies (CA) in the offspring of health workers potentially exposed to radiation. Methods In a prospective follow-up study, we enrolled women, identified by mandatory registration at the office of radiation protection as wearing a dosimeter. The participating women answered a questionnaire and if pregnant agreed to an examination of their infant. CA were diagnos…
New customized elbow orthosis made by additive manufacturing
2019
Orthoses are additional devices that help people with disabilities. The focus of this work is the design and manufacture of a new customized elbow orthosis completely made by Additive Manufacturing (AM). One of the innovative characteristic of the device is the use of torsion springs that simulate the action of physiotherapists during exercises for patient rehabilitation. Parametric modeling approach based on generative algorithms was used to design the device. Finally, FEM analyses have been performed to validate the design.
Investigation of thick sheet AHSS springback in combined bending under tension
2012
In this paper, we investigate the springback behavior of several advanced high-strength sheet steels (TRIP, Dual-Phase, ferrite-bainite) with thicknesses up to 4 mm. Samples were tested by means of the bending-under-tension (BUT) test. The BUT has been extensively applied, in the literature, to relatively thin (1 mm and thinner) sheet metals for automotive applications; the applicability of several guidelines from the literature was investigated in this work in the context of thick advanced high strength steel (AHSS) sheets and using a sample width of 12 mm. The monotonic decrease of springback as back force increased was confirmed for this category of sheet steels, and a general trend for …
Network Arches: The World's Lightest Arch Bridges
2012
Summary Network arches have a tensile and a compressive flange with a web consisting of crossing hangers. Some of the hangers cross each other twice. The network can be seen as a very light, simply supported beam. There is little bending. There is a lot of tension in tie and hangers. The arches are well supported by hangers and wind bracing. Thus the buckling strength of the arch is high as long as few hangers relax. That is easiest to prevent when a concrete tie gives extra weight in the tie. The optimal shape of network arches is discussed. In two lane and two track network arches the biggest bending in the tie is usually the transverse bending half way between the arches. The optimal sha…