Engineered mosquitoes to fight mosquito borne diseases: not a merely technical issue

Malaria, dengue and other mosquito-borne diseases pose dramatic problems of public health, particularly in tropical and sub-tropical countries. Historically, vector control has been one of the most successfully strategies to eradicate some mosquito-borne diseases, as witnessed by malaria eradication in Mediterranean regions such as Italy and Greece. Vector control through insecticides has been used worldwide; unfortunately, it is losing effectiveness due to spread of resistances. Control of mosquito-borne diseases through field-releases of genetically engineered mosquitoes is an innovative and now feasible approach. Genetically modified mosquitoes have already been released into the wild in some regions, and protocols for this release are on hand in others. Local authorities are vigilant that transgenic insects in the field are safe for human and animal populations, and the public engagement in every control program is assuming a central role

Study of the beam-cavity interaction in the PS 10 MHz RF system

The eleven main accelerating cavities of the Proton Synchrotron (PS) at CERN consist of two ferrite-loaded coaxial lambda/4 resonators each. Both resonators oscillate in phase, as their gaps are electrically connected by short bars. They are in addition magnetically coupled via the bias loop used for cavity tuning. The cavities are equipped with a wide-band feedback system, limiting the beam loading, and a further reduction of the beam induced voltage is achieved by relays which short-circuit each half-resonator gap when the cavity is not in use. Asymmetries of the beam induced voltage observed in the two half-cavities indicate that the coupling between the two resonators is not as tight as expected. The total cavity impedance coupling to the beam may be affected differently by the contributions of both resonators. A dedicated measurement campaign with high-intensity proton beam and numerical simulation have been performed to investigate the beam-cavity interaction. This paper reports the result of the study and the work aiming at the development of a model of the system, including the wide-band feedback, which reproduces this interaction

An Inventory of Student Recollections of Their Past Misconceptions as a Tool for Improved Classroom Astronomy Instruction

My Ph.D. research is about examining the persistence of 215 common misconceptions in astronomy. Each misconception is based on an often commonlyheld incorrect belief by college students taking introductory astronomy. At the University of Maine, the course is taught in alternating semesters by Prof. Neil F. Comins and Prof. David J. Batuski. In this dissertation, I examine the persistence of common astronomy misconceptions by the administration of a retrospective survey. The survey is a new instrument in that it permits the student to indicate either endorsement or rejection of each misconception at various stages in the student’s life. I analyze data from a total of 639 students over six semesters. I compare the survey data to the results of exams taken by the students and additional instruments that assess students’ misconceptions prior to instruction. I show that the consistency of the students’ recollection of their own misconceptions is on par with the consistency of responses between prelims and the final exam. I also find that students who report higher increased childhood interest in astronomy are more likely to have accurate recalls of their own past recollections. I then discuss the use of principal components analysis as a technique for describing the extent to which misconceptions are correlated with each other. The analysis yields logical groupings of subtopics from which to teach. I then present a brief overview of item response theory, the methodology of which calculates relative difficulties of the items. My analysis reveals orders to teach the associated topics in ways that are most effective at dispelling misconceptions during instruction. I also find that the best order to teach the associated concepts is often different for high school and college level courses

Ned-19 inhibition of parasite growth and multiplication suggests a role for NAADP mediated signalling in the asexual development of plasmodium falciparum

BACKGROUND: Although malaria is a preventable and curable human disease, millions of people risk to be infected by the Plasmodium parasites and to develop this illness. Therefore, there is an urgent need to identify new anti-malarial drugs. Ca2+ signalling regulates different processes in the life cycle of Plasmodium falciparum, representing a suitable target for the development of new drugs. RESULTS: This study investigated for the first time the effect of a highly specific inhibitor of nicotinic acid adenine dinucleotide phosphate (NAADP)-induced Ca2+ release (Ned-19) on P. falciparum, revealing the inhibitory effect of this compound on the blood stage development of this parasite. Ned-19 inhibits both the transition of the parasite from the early to the late trophozoite stage and the ability of the late trophozoite to develop to the multinucleated schizont stage. In addition, Ned-19 affects spontaneous intracellular Ca2+ oscillations in ring and trophozoite stage parasites, suggesting that the observed inhibitory effects may be associated to regulation of intracellular Ca2+ levels. CONCLUSIONS: This study highlights the inhibitory effect of Ned-19 on progression of the asexual life cycle of P. falciparum. The observation that Ned-19 inhibits spontaneous Ca2+ oscillations suggests a potential role of NAADP in regulating Ca2+ signalling of P. falciparum

The PS 10 MHz High Level RF System Upgrade

In view of the upgrade of the injectors for the High Luminosity LHC, significantly higher bunch intensity is required for LHC-type beams. In this context an upgrade of the main accelerating RF system of the Proton Synchrotron (PS) is necessary, aiming at reducing the cavity impedance which is the source of longitudinal coupled-bunch oscillations. These instabilities pose as a major limitation for the increase of the beam intensity as planned after LS2. The 10 MHz RF system consists in 11 ferrite loaded cavities, driven by tube-based power amplifiers for reasons of radiation hardness. The cavity-amplifier system is equipped with a wide-band feedback that reduces the beam induced voltage. A further reduction of the beam loading is foreseen by upgrading the feedback system, which can be reasonably achieved by increasing the loop gain of the existing amplification chain. This paper describes the progress of the design of the upgraded feedback system and shows the results of the tests on the new amplifier prototype, installed in the PS during the 2015-16 technical stop. It also reports the first results of its performance with beam, observed in the beginning of the 2016 run

Data Analysis Using Item Response Theory Methodology: An Introduction to Selected Programs and Applications.

There are two approaches to psychometrics. Classical test theory is the traditional approach, focusing on test-retest reliability, internal consistency, various forms of validity, and normative data and standardization. Modern test theory or item response theory (IRT) focuses on how specific test items function in assessing constructs. IRT makes it possible to scale test items for difficulty, to design parallel forms of tests, and to provide for adaptive computerized testing (DeMars, 2010). “(T)he basic concepts of item response theory rest upon the individual items of a test rather than upon some aggregate of the item responses such as a test score” (Baker, 1985/2001, p. 6). Using IRT methodology in data analysis can be challenging because “IRT programs are still much more traditional and ‘user-unfriendly’ than many commercially-available statistical packages” (Kline, 2005, p. 107). This paper outlines some of the basic procedures involved in using two representative programs: MULTILOG (du Toit, 2003; Thissen, Chen, & Bock, 2003) and PARSCALE (du Toit, 2003; Muraki & Bock, 2003). A third program, WINSTEPS (Bond & Fox, 2007; Linacre, 2006), is also noted briefly. Also provided is some of the essential background material on IRT theory and rationale, and on its requirements and assumptions. Readers are encouraged to consult the software manuals, books, chapters, and articles in the reference list for more detailed information on technique and for authoritative and definitive theoretical coverage