A piezoelectric micropump based on micromachining of silicon

The design and realization of two pumps based on micromachining of silicon are described. The pumps, which are of the reciprocating displacement type, comprise one or two pump chambers, a thin glass pump membrane actuated by a piezoelectric disc and passive silicon check valves to direct the flow. Chambers, channels and valves are realized in a silicon wafer by wet chemical etching. The results of mechanical calculations and simulations show good agreement with the actual behaviour of the pumps. It is possible to design pumps having a specific yield and pressure dependence, and which are fail-safe (the flow is blocked while the pump is switched off)

Producing sons reduces lifetime reproductive success of subsequent offspring in pre-industrial Finns

Life-history theory states that reproductive events confer costs upon mothers. Many studies have shown that reproduction causes a decline in maternal condition, survival or success in subsequent reproductive events. However, little attention has been given to the prospect of reproductive costs being passed onto subsequent offspring, despite the fact that parental fitness is a function of the reproductive success of progeny. Here we use pedigree data from a pre-industrial human population to compare offspring life-history traits and lifetime reproductive success (LRS) according to the cost incurred by each individual's mother in the previous reproductive event. Because producing a son versus a daughter has been associated with greater maternal reproductive cost, we hypothesize that individuals born to mothers who previously produced sons will display compromised survival and/or LRS, when compared with those produced following daughters. Controlling for confounding factors such as socio-economic status and ecological conditions, we show that those offspring born after elder brothers have similar survival but lower LRS compared with those born after elder sisters. Our results demonstrate a maternal cost of reproduction manifested in reduced LRS of subsequent offspring. To our knowledge, this is the first time such a long-term intergenerational cost has been shown in a mammal species

Media Roles in the Online News Domain: Authorities and Emergent Audience Brokers

This article empirically tests the role of legacy and digital-born news media, mapping the patterns of audience navigation across news sources and the relationship between news providers. We borrow tools from network science to bring evidence that suggest legacy news media retain control of the most central positions in the online news domain. Great progress has been made in discussing theoretically the impact of the Internet on the news media ecology. Less research attention, however, has been given to empirically testing changes in the role of legacy media and the rising prominence of digital-born outlets. To fill this gap, in this study we use the hyperlink-induced topic search algorithm, which identifies authorities by means of a hyperlink network, to show that legacy media are still the most authoritative sources in the media ecology. To further substantiate their dominant role, we also examine the structural position of news providers in the audience network. We gather navigation data from a panel of 30,000 people and use it to reproduce the network of patterns of news consumption. While legacy news media retain control of the brokerage positions for the general population, our analysis - focused on patterns of young news consumers - reveals that new digital outlets also occupy relevant positions to control the audience flow. The results of this study have substantive implications for our understanding of news organizations’ roles and how they attain authority in the digital age

Two-dimensional non-commutative Yang-Mills theory: coherent effects in open Wilson line correlators

A perturbative calculation of the correlator of three parallel open Wilson lines is performed for the U(N) theory in two non-commutative space-time dimensions. In the large-N planar limit, the perturbative series is fully resummed and asymptotically leads to an exponential increase of the correlator with the lengths of the lines, in spite of an interference effect between lines with the same orientation. This result generalizes a similar increase occurring in the two-line correlator and is likely to persist when more lines are considered provided they share the same direction.Comment: 22 pages, 1 figure, typeset in JHEP styl

How does the general public balance convenience and cognitive pharmaceutical services in community pharmacy practice

Background: Community pharmacy is shifting its focus from traditional, product-focused roles to the provision of cognitive pharmaceutical services (CPS). Previous research has indicated that community pharmacists predominantly want to devote their capacity to CPS. Ideally, services provided also address users' needs. The general public's preferences regarding the services provided by community pharmacists are currently less understood. Aim: This study investigates the general public's preferences and perceived importance of CPS versus convenience in community pharmacy practice. Method: An online survey of 1.500 members of the Dutch Health Care Consumer Panel containing questions regarding preferences for CPS and convenience was distributed. Descriptive statistics and linear regression analysis were performed to investigate the relationship between preferences and participant characteristics. Results: 516 panel members completed all questions regarding preferences and importance of the availability of services. The majority preferred convenience (68.2%) and a smaller proportion preferred CPS (27.7%). However, participants considered it important from a societal viewpoint that CPS is provided (45.0%). Participants who preferred CPS over convenience were generally older (p < 0.001) and used more medicines (p < 0.001). Conclusion: Convenience of community pharmacy services is most preferred by the general public. However, CPS is perceived as important, especially for elderly who use more medicines. Elderly patients who use more medicines more often rate CPS as more important than convenience. These findings suggest that community pharmacists should ensure that pharmacy logistics are organized efficiently before focusing on the provision of CPS

Distributed Branching Bisimulation Minimization by Inductive Signatures

We present a new distributed algorithm for state space minimization modulo branching bisimulation. Like its predecessor it uses signatures for refinement, but the refinement process and the signatures have been optimized to exploit the fact that the input graph contains no tau-loops. The optimization in the refinement process is meant to reduce both the number of iterations needed and the memory requirements. In the former case we cannot prove that there is an improvement, but our experiments show that in many cases the number of iterations is smaller. In the latter case, we can prove that the worst case memory use of the new algorithm is linear in the size of the state space, whereas the old algorithm has a quadratic upper bound. The paper includes a proof of correctness of the new algorithm and the results of a number of experiments that compare the performance of the old and the new algorithms