A Laboratory Experiment Using Nanoindentation to Demonstrate the Indentation Size Effect

A laboratory experiment using nanoindentation to demonstrate the indentation size effect is described. This laboratory introduces students to sophisticated instrumentation at low cost and low risk and utilizes recent research in the materials community as its foundation. The motivation, learning objectives, experimental details, data, and data analysis are presented. This experiment is intended for use in an upper-division materials science elective at the university level and has been successfully used in laboratory courses for senior undergraduates and first-year graduate students at Stanford University and Santa Clara University.

Friendship as a relationship infiltration tactic during human mate poaching.

Previous research has characterized human mate poaching as a prevalent alternative mating strategy that entails risks and costs typically not present during general romantic courtship and attraction. This study is the first to experimentally investigate friendship between a poacher and his/her target as a risk mitigation tactic. Participants (N = 382) read a vignette that differed by whether the poacher was male/female and whether the poacher and poached were friends/acquaintances. Participants assessed the likelihood of the poacher being successful and incurring costs. They also rated the poacher and poached on several personality and mate characteristics. Results revealed that friendship increased the perceived likelihood of success of a mate poaching attempt and decreased the perceived likelihood of several risks typically associated with mate poaching. However, friend-poachers were rated less favorably than acquaintance-poachers across measures of warmth, nurturance, and friendliness. These findings are interpreted using an evolutionary perspective. This study complements and builds upon previous findings and is the first experimental investigation of tactics poachers may use to mitigate risks inherent in mate poaching.

Friendship as a Relationship Infiltration Tactic during Human Mate Poaching

Previous research has characterized human mate poaching as a prevalent alternative mating strategy that entails risks and costs typically not present during general romantic courtship and attraction. This study is the first to experimentally investigate friendship between a poacher and his/her target as a risk mitigation tactic. Participants (N = 382) read a vignette that differed by whether the poacher was male/female and whether the poacher and poached were friends/acquaintances. Participants assessed the likelihood of the poacher being successful and incurring costs. They also rated the poacher and poached on several personality and mate characteristics. Results revealed that friendship increased the perceived likelihood of success of a mate poaching attempt and decreased the perceived likelihood of several risks typically associated with mate poaching. However, friend-poachers were rated less favorably than acquaintance-poachers across measures of warmth, nurturance, and friendliness. These findings are interpreted using an evolutionary perspective. This study complements and builds upon previous findings and is the first experimental investigation of tactics poachers may use to mitigate risks inherent in mate poaching.

The Design of XML-Based Model and Experiment Description Languages for Network Simulation

The Simulation Automation Framework for Experiments (SAFE) is a project created to raise the level of abstraction in network simulation tools and thereby address issues that undermine credibility. SAFE incorporates best practices in network simulationto automate the experimental process and to guide users in the development of sound scientific studies using the popular ns-3 network simulator. My contributions to the SAFE project: the design of two XML-based languages called NEDL (ns-3 Experiment Description Language) and NSTL (ns-3 Script Templating Language), which facilitate the description of experiments and network simulationmodels, respectively. The languages provide a foundation for the construction of better interfaces between the user and the ns-3 simulator. They also provide input to a mechanism which automates the execution of network simulation experiments. Additionally,this thesis demonstrates that one can develop tools to generate ns-3 scripts in Python or C++ automatically from NSTL model descriptions.

Formation of Phosphatidylethanol and Its Subsequent Elimination During an Extensive Drinking Experiment Over 5 Days

BACKGROUND: For almost 30 years, phosphatidylethanol (PEth) has been known as a direct marker of alcohol consumption. This marker stands for consumption in high amounts and for a longer time period, but it has been also detected after 1 high single intake of ethanol (EtOH). The aim of this study was to obtain further information about the formation and elimination of PEth 16:0/18:1 by simulating extensive drinking. METHODS: After 3 weeks of alcohol abstinence, 11 test persons drank an amount of EtOH leading to an estimated blood ethanol concentration of 1 g/kg on each of 5 successive days. After the drinking episode, they stayed abstinent for 16 days with regular blood sampling. PEth 16:0/18:1 analysis was performed using liquid chromatography-tandem mass spectrometry (high-performance liquid chromatography 1100 system and QTrap 2000 triple quadrupole linear ion trap mass spectrometer. Values of blood alcohol were obtained using a standardized method with headspace gas chromatography flame ionization detector. RESULTS: Maximum measured concentrations of EtOH were 0.99 to 1.83 g/kg (mean 1.32 g/kg). These values were reached 1 to 3 hours after the start of drinking (mean 1.9 hours). For comparison, 10 of 11 volunteers had detectable PEth 16:0/18:1 values 1 hour after the start of drinking, ranging from 45 to 138 ng/ml PEth 16:0/18:1. Over the following days, concentrations of PEth 16:0/18:1 increased continuously and reached the maximum concentrations of 74 to 237 ng/ml between days 3 and 6. CONCLUSIONS: This drinking experiment led to measurable PEth concentrations. However, PEth 16:0/18:1 concentrations stayed rather low compared with those of alcohol abusers from previous studies.

Brain infiltration of leukocytes contributes to the pathophysiology of temporal lobe epilepsy

Clinical and experimental evidence indicates that inflammatory processes contribute to the pathophysiology of epilepsy, but underlying mechanisms remain mostly unknown. Using immunohistochemistry for CD45 (common leukocyte antigen) and CD3 (T-lymphocytes), we show here microglial activation and infiltration of leukocytes in sclerotic tissue from patients with mesial temporal lobe epilepsy (TLE), as well as in a model of TLE (intrahippocampal kainic acid injection), characterized by spontaneous, nonconvulsive focal seizures. Using specific markers of lymphocytes, microglia, macrophages, and neutrophils in kainate-treated mice, we investigated with pharmacological and genetic approaches the contribution of innate and adaptive immunity to kainate-induced inflammation and neurodegeneration. Furthermore, we used EEG analysis in mutant mice lacking specific subsets of lymphocytes to explore the significance of inflammatory processes for epileptogenesis. Blood-brain barrier disruption and neurodegeneration in the kainate-lesioned hippocampus were accompanied by sustained ICAM-1 upregulation, microglial cell activation, and infiltration of CD3(+) T-cells. Moreover, macrophage infiltration was observed, selectively in the dentate gyrus where prominent granule cell dispersion was evident. Unexpectedly, depletion of peripheral macrophages by systemic clodronate liposome administration affected granule cell survival. Neurodegeneration was aggravated in kainate-lesioned mice lacking T- and B-cells (RAG1-knock-out), because of delayed invasion by Gr-1(+) neutrophils. Most strikingly, these mutant mice exhibited early onset of spontaneous recurrent seizures, suggesting a strong impact of immune-mediated responses on network excitability. Together, the concerted action of adaptive and innate immunity triggered locally by intrahippocampal kainate injection contributes seizure-suppressant and neuroprotective effects, shedding new light on neuroimmune interactions in temporal lobe epilepsy.

[Musculoskeletal puncture, injection and infiltration: swiss rheumatologists' point of view]

Arthrocentesis, injection and infiltration of joints and soft tissues belong to the basic procedures in rheumatology. The indications and the practical performance are based on experience and tradition. Nowadays, a crucial reappraisal and adaption of indications and technical aspects appear important in the light of new evidence and technical developments. The main indications for puncture remain the search of an infectious arthritis and reduction of intra-articular pressure due to effusion. Good indications for the injection of glucocorticoids are inflammation in sterile joints and activated osteoarthritis. The local infiltration with corticosteroids in mechanically induced enthesopathies at the lateral epicondyle of the humerus or at the plantar fascia have to be questioned in the light of recent publications which show that this common practice is associated with a poorer outcome than without injection.

Production and characterization of a custom-made 228Th source with reduced neutron source strength for the Borexino experiment

A custom-made 228Th source of several MBq activity was produced for the Borexino experiment for studying the external background of the detector. The aim was to reduce the unwanted neutron emission produced via (alpha,n) reactions in ceramics used typically for commercial 228Th sources. For this purpose a ThCl4 solution was converted chemically into ThO2 and embedded into a gold foil. The paper describes the production and the characterization of the custom-made source by means of gamma-activity, dose rate and neutron source strength measurements. From gamma-spectroscopic measurements it was deduced that the activity transfer from the initial solution to the final source was >91% (at 68% C.L.) and the final activity was (5.41+-0.30) MBq. The dose rate was measured by two dosimeters yielding 12.1 mSv/h and 14.3 mSv/h in 1 cm distance. The neutron source strength of the 5.41 MBq 228Th source was determined as (6.59+-0.85)/sec.