Viscous Decoupling Transitions for Individually Dragged Particles in Systems with Quenched Disorder

We show that when an individual particle is dragged through an assembly of other particles in the presence of quenched disorder, a viscous decoupling transition occurs between the dragged particle and the surrounding particles which is controlled by the quenched disorder. A counterintuitive consequence of this transition is that the velocity of the dragged particle can be increased by increasing the strength or density of the quenched disorder. The decoupling transition can also occur when the external drive on the dragged particle is increased, and is observable as a clear signature in the velocity-force response.Comment: 4 pages, 3 postscript figure

Magnetic Response of Magnetospirillum Gryphiswaldense

In this study we modelled and measured the U-turn trajectories of individual magnetotactic bacteria under the application of rotating magnetic fields, ranging in ampitude from 1 to 12 mT. The model is based on the balance between rotational drag and magnetic torque. For accurate verification of this model, bacteria were observed inside 5 m tall microfluidic channels, so that they remained in focus during the entire trajectory. From the analysis of hundreds of trajectories and accurate measurements of bacteria and magnetosome chain dimensions, we confirmed that the model is correct within measurement error. The resulting average rate of rotation of Magnetospirillum Gryphiswaldense is 0.74 +- 0.03 rad/mTs.Comment: 17 pages, 12 figure

The Impact of Corruption on Firm Tax Compliance in Transition Economies: Whom Do You Trust?

Tax compliance is an important issue for governments and the public alike. To meet public needs and fund public mandates, firms around the world are expected to comply with tax laws. Factors that are related to organizational (firm) tax compliance have not been sufficiently examined in the literature. Due to the increasing global influence of transition economies, factors associated with firm tax compliance in transition economies are particularly of interest. Based on a sample of over 5,000 firms from 22 former Soviet Bloc transition economies, we find that higher levels of corruption and higher levels of particularized trust (reliance on friends and family) are associated with lower levels of tax compliance. Interestingly, we also find that the negative relationship between corruption and tax compliance is weakened in situations of higher generalized trust (trust in strangers). Overall, our study’s results suggest that institutional factors play an important role and are related to firm tax compliance behavior in transition economies

Presentation Basics: Skills, Techniques, and Learning Styles

When designing an instructional session, librarians need to consider what information, resources, and techniques need to be included to make the session memorable and part of the learning experience. The opening and closing should be developed, and goals and objectives for the presentation should be set. Break up the session into “teachable chunks” to fit the attention span of the attendees. “Active learning” techniques can be included in designing the session and as methods of evaluating the presentation. Activities should be based on the presentation objectives, and can include icebreakers, games and exercises. Consider various learning styles, and think about ways to reach the individuals in the audience. Methods of assessing the presentation should be developed to evaluate whether the students are grasping the concepts covered in the session. There are many methods of evaluating during an instructional session. These include the T-chart (identifying the pros and cons of a topic); index cards (what the students liked best/least); a wish list (used at the beginning of the session, then checked at the end); “Dear Instructor” (students record what they would stop doing, start doing, or continue to do because of what they learned in the session); contests, games, and puzzles; and discussion groups. By examining adult learning styles and combining that knowledge with various presentation techniques, the instruction session can be interesting and retain the attention of attendees

Paediatric admissions to hospitals in the Cape Town Metro district: A survey

A point prevalence survey of 381 paediatric medical inpatients in the 11 public hospitals in Cape Town in November 2007 showed that 70% of them were in central hospitals, with 39.4% requiring level 3 (sub-specialist) care. Numbers of children in hospital and their levels of health care requirement did not vary by sub-district of residence. Seventy-seven per cent of patients were under 5 years of age; 5% were teenagers. Few patients changed level of care during admission, but 10% did not need to be in hospital at the time of review. Median length of stay was 4 days, with children with level 3 needs having the longest lengths of stay. An under-provision of level 1 beds was demonstrated. HIV infection had been identified in 12% of admissions. While children with level 3 problems were well catered for in terms of bed provision, level 1 and step-down/home care provision were deficient or inefficiently utilised

La réception du théâtre de Voltaire dans les Provinces-Unies au XVIIIème siècle

The Reception of Voltaire’s theater in the Netherlands during the eighteenth century. Nowadays, when you think about Voltaire, you think about his “Tales”. Who does not know Candide or Zadig? However, in the XVIIIth century, he was famous and wanted to be celebrated for his theater. A few specialists already studied the reception of his theater in France. But what happened outside France? It seems that Voltaire as a dramatist was very appreciated in the Europe of the Enlightment. He is in the “United Provinces”, today the Netherlands, seen as the main figure of Classicism. Moreover, some aspects of his plays were found of particular interest: the exoticism of some of them, and specifically the patriotism often intensified in the translations. We talk about his tragedies like Zaïre, the best known, but we forget his comedies most of the time. However, the public loved them have been in a country, where despite the critics, the French culture has kept her Glory.LEI Universiteit LeidenMedieval and Early Modern Studie

Wharton’s jelly or bone marrow mesenchymal stromal cells improve cardiac function following myocardial infarction for more than 32 weeks in a rat model: a preliminary report

The therapeutic effect of mesenchymal stromal cells (MSCs) following myocardial infarction (MI) is small. This may be due to differences in cellular sources and donor age, route of administration, in vitro cellular manipulations and the short time course of follow up in many animal studies. Here, we compared MSCs from two different sources (adult bone marrow or Wharton’s jelly from umbilical cord) for their long-term therapeutic effect following MI in a rat model to evaluate the effect of donor age. MSCs (or control infusions) were given intravenously 24-48 hr after myocardial ischemia (MI) induced by coronary artery ligation. Cardiac function was assessed by ultrasound at time points starting from before MSC infusion through 68 weeks after MI. A significant improvement in ejection fraction was seen in animals that received MSCs in time points 25 to 31 wks after treatment (p <0.01). These results support previous work that show that MSCs can cause improvement in cardiac function and extend that work by showing that the beneficial effects are durable. To investigate MSCs’ cardiac differentiation potential, Wharton’s jelly MSCs were co-cultured with fetal or adult bone-derived marrow MSCs. When Wharton’s jelly MSCs were co-cultured with fetal MSCs, and not with adult MSCs, myotube structures were observed in two-three days and spontaneous contractions (beating) cells were observed in fiveseven days. The beating structures formed a functional syncytium indicated by coordinated contractions (beating) of independent nodes. Taken together, these results suggest that MSCs given 24-48 hr after MI have a significant and durable beneficial effect more than 25 weeks after MI and that MSC treatment can home to damaged tissue and improve heart function after intravenous infusion 24-48 hrs after MI, and that WJCs may be a useful source for off-the-shelf cellular therapy for MI

Planar manipulation of magneto-tactic bacteria using unidirectional magnetic fields

We show for the first time that an alternating unidirectional magnetic field generated by a magnetic erase head allows planar manipulation of magneto-tactic bacteria (MTB), and is not restricted to parallel directions only. We used squared-shaped magnetic fields of approximately 4 mT while sweeping from 0.25 to 10 Hz, and found that at frequencies of over 3 Hz the mean orthogonal velocity becomes constant. The erase head offers a significant reduction in size and complexity over conventional manipulators

Protective chromosome 1q32 haplotypes mitigate risk for age-related macular degeneration associated with the CFH-CFHR5 and ARMS2/HTRA1 loci

Background: Single-variant associations with age-related macular degeneration (AMD), one of the most prevalent causes of irreversible vision loss worldwide, have been studied extensively. However, because of a lack of refinement of these associations, there remains considerable ambiguity regarding what constitutes genetic risk and/or protection for this disease, and how genetic combinations affect this risk. In this study, we consider the two most common and strongly AMD-associated loci, the CFH-CFHR5 region on chromosome 1q32 (Chr1 locus) and ARMS2/HTRA1 gene on chromosome 10q26 (Chr10 locus). Results: By refining associations within the CFH-CFHR5 locus, we show that all genetic protection against the development of AMD in this region is described by the combination of the amino acid-altering variant CFH I62V (rs800292) and genetic deletion of CFHR3/1. Haplotypes based on CFH I62V, a CFHR3/1 deletion tagging SNP and the risk variant CFH Y402H are associated with either risk, protection or neutrality for AMD and capture more than 99% of control- and case-associated chromosomes. We find that genetic combinations of CFH-CFHR5 haplotypes (diplotypes) strongly influence AMD susceptibility and that individuals with risk/protective diplotypes are substantially protected against the development of disease. Finally, we demonstrate that AMD risk in the ARMS2/HTRA1 locus is also mitigated by combinations of CFH-CFHR5 haplotypes, with Chr10 risk variants essentially neutralized by protective CFH-CFHR5 haplotypes. Conclusions: Our study highlights the importance of considering protective CFH-CFHR5 haplotypes when assessing genetic susceptibility for AMD. It establishes a framework that describes the full spectrum of AMD susceptibility using an optimal set of single-nucleotide polymorphisms with known functional consequences. It also indicates that protective or preventive complement-directed therapies targeting AMD driven by CFH-CFHR5 risk haplotypes may also be effective when AMD is driven by ARMS2/HTRA1 risk variants