Do Campaign Contribution Limits Curb the Influence of Money in Politics?

Over 40% of countries around the world have adopted limits on campaign contributions to curb the influence of money in politics. Yet, we have limited knowledge on whether and how these limits achieve this goal. With a regression discontinuity design that uses institutional rules on contribution limits in Colombian municipalities, we show that looser limits increase the number and value of public contracts assigned to the winning candidate’s donors. The evidence suggests that this is explained by looser limits concentrating influence over the elected candidate among top donors and not by a reduction in electoral competition or changes in who runs for office. We further show that looser limits worsen the performance of donor-managed contracts: they are more likely to run over costs and require time extensions. Overall, this paper demonstrates a direct link between campaign contribution limits, donor kickbacks, and worse government contract performance

Autonomía docente: ¿logra el sistema educativo español el efecto deseado?

A pesar de que el currículo español para la educación primaria establece asignaturas troncales y específicas para promover la autonomía docente, la gestión curricular está logrando el efecto contrario según el profesorado. El objetivo de este estudio es comparar estadísticamente la autonomía de maestras y maestros que imparten asignaturas troncales y de quienes enseñan solo asignaturas específicas. El método comprende un diseño cuantitativo no experimental, estableciendo una muestra aleatoria estratificada que tiene representatividad nacional. Los resultados demuestran que el profesorado que solo imparte asignaturas específicas percibe mayor satisfacción hacia la actividad pedagógica que el otro grupo. En conclusión, es razonable poner bajo escrutinio el currículo español porque su efectividad para fomentar la autonomía docente queda cuestionada.Despite the Spanish curriculum for primary education establishes compulsory and elective subjects in order to promote teacher autonomy; curricular management is achieving the opposite of the desired effect according to teachers. This study aims statistically comparing the autonomy of educators who teach compulsory subjects and who only impart elective subjects. The method comprises a nonexperimental quantitative research design, establishing a random cluster sampling that has statistical representativeness from national standpoint. Results demonstrate that teachers who only impart elective subjects perceive a greater enjoyment toward pedagogical activity than the other group. In conclusion, it is reasonable to put the Spanish curriculum under scrutiny because its effectiveness for fostering the teacher autonomy is questioned.The first author expresses his gratitude to the CONICYT PFCHA/DOCTORADO BECAS CHILE/2015 for the granted doctoral scholarship. In addition, this study was supported by the I+D+i State Programme oriented towards Challenges of the Society (grant number EDU2017-84979-R)

Ac magnetic susceptibility of a molecular magnet submonolayer directly patterned onto a microSQUID sensor

We report the controlled integration, via Dip Pen Nanolithography, of monolayer dots of ferritin-based CoO nanoparticles (12 Bohr magnetons) into the most sensitive areas of a microSQUID sensor. The nearly optimum flux coupling between these nanomagnets and the microSQUID improves the achievable sensitivity by a factor 100, enabling us to measure the linear susceptibility of the molecular array down to very low temperatures (13 mK). This method opens the possibility of applying ac susceptibility experiments to characterize two-dimensional arrays of single molecule magnets within a wide range of temperatures and frequencies.Comment: 4 pages 3 figure

Additive manufacturing of mode converters in Ku and Q bands by selective laser sintering: experience and results

In recent years, Additive Manufacturing (AM) has turned out as a disruptive technology [1]. Fast production, rapid prototyping or adaptability, are essential concepts in sectors such as automotive, aerospace, biotech, etc. [2], [3]. In microwave engineering, the main advantages of AM are the possibility to produce customized items and the complexity of the implemented geometries compared with other technologies such as Computer Numerical Control (CNC) machining, injection moulding, casting or Electrical Discharge Machining (EDM). Nowadays, AM technologies are focused on the development of the next generation of microwave and millimetrewave devices. Regarding high-frequency circuits, and more specifically in the case of waveguide technology devices, the impact has been very relevant [4]. The initial efforts have been focused on filters, couplers, feed components and antennas. However, in this work the experience and results with other sort of devices, i.e., the mode converters, will be exposed. These broadband devices without resonant behaviour and strong electromagnetic fields are especially well-suited to cope with the two main problems of AM, i.e., the manufacturing accuracy and the surface roughness. Two different mode converters have been designed and manufactured by means of Selective Laser Sintering technology using aluminium alloy powder. The first one is a TE10 rectangular mode to TM01 circular mode converter in Ku-band and the second one is a TE10 rectangular mode to TE01 circular mode flared-type converter in Q-band. The experimental results obtained in both cases will be presented in detail. In addition, the issues related to the orientation of the parts inside the building chamber and other undesirable effects such as spikes due to manufacturing asymmetries, will be shared with the scientific community

Metodología de estudio del aprendizaje de niños con parálisis cerebral en el uso de un ratón por movimientos de cabeza

This paper presents a methodology designed to evaluate the learning process for people with cerebral palsy (CP) who are asked to control a computer through an inertial interface. The interface allows users to control the mouse pointer and click with head movements. The metric proposed in order to objectively measure the process of learning is the “throughput”. This parameter has been widely used for the evaluation of pointing devices and is now applied for the first time to people with CP. The results obtained show that the metric can be used to quantify how the user is learning and therefore to assess the usability of the inertial device.[EN]Este artículo presenta un estudio piloto que introduce una metodología para valorar el aprendizaje de una persona con parálisis cerebral (PC) en el manejo del computador con una interfaz inercial, que permite el control del cursor y el clic mediante movimientos de cabeza. Se propone el uso de una métrica denominada rendimiento para medir objetivamente el proceso de aprendizaje. La métrica, ampliamente utilizada para la evaluación de dispositivos apuntadores, se aplica por primera vez en usuarios con PC. Los resultados obtenidos muestran cómo la métrica propuesta permite cuantificar el proceso de aprendizaje del usuario con PC, con lo que puede ser empleada para valorar la usabilidad del dispositivo inercial.[ES]Peer reviewe

Time-expanded FOTDR based on Orthogonal Polarization Frequency Comb generation

Phase-sensitive Optical Time-Domain Reflectometry (ΦOTDR) has emerged as an effective and high-performance solution within the realm of Distributed Optical Fiber Sensing (DOFS) technologies, which has promoted its use in an ever-growing number of fields. The challenges arisen by new operation fields demand surpassing the historical trade-offs in this technology, specially aiming for higher resolution without jeopardizing the system simplicity and cost-effectiveness. In this context, time-expanded (TE-)ΦOTDR has been recently proposed as a DOFS solution delivering cm-range resolution with sub-MHz detection and acquisition bandwidths. It is based on the use of an interferometric scheme that employs a dual frequency comb (DFC), consisting of two mutually coherent optical frequency combs with dissimilar repetition rates. In this paper, we present a novel DFC generation scheme for TE-ΦOTDR that exploits the polarization orthogonality. In particular, our approach considerably increases the common path followed by the two frequency combs, thus reducing instability and noise as compared to the conventional generation scheme. Additionally, we employ an IQ modulation scheme with two PRBS generators that increases the scalability of the interrogator while severely reducing its cost and complexity. Results show a reduction in the noise amplitude spectral density especially at low frequency values, which corroborates the stability enhancement of this proposed architecture as compared to the conventional scheme

Geminivirus replication protein decreases PCNA sumoylation at two acceptor sites

Geminiviruses are plant viruses with circular, single-stranded DNA (ssDNA) genomes that infect a broad range of plants causing substantial crop diseases worldwide. They replicate in nuclei of infected cells by using host DNA replication machinery and an essential protein encoded in their genome designated Rep (replication-associated protein). This multifunctional protein induces the accumulation of the host factors involved in replication and it is capable of interacting with a lot of plant proteins including PCNA (Proliferating Cell Nuclear Antigen), a processivity factor that coordinates a wide range of processes involved in maintenance, duplication and transmission of the genome, and the sumoylation enzyme that conjugates SUMO to target proteins (SUMO-conjugating enzyme- SCE). PCNA modification by SUMO, and also ubiquitin, has long been known to be of key importance for determining how DNA damage is processed by the replisome and for maintenance of overall genome integrity. In yeast, PCNA sumoylation has been associated to DNA repair involving homologous recombination (HR). Previously, we reported that Rep ectopic expression does not result in broad changes in the sumoylation pattern of plant cells, but it modifies the sumoylation state of selected host proteins. In this work, we show, using a reconstituted sumoylation system in Escherichia coli, that tomato PCNA is sumoylated at two residues, K254 and K164, and that co-expression of the Rep protein suppresses PCNA sumoylation at these lysines. Finally, we confirm that PCNA is sumoylated and that Rep also interferes with PCNA sumoylation in planta.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Food Chemistry: Food quality and new analytical approaches

Peer Reviewe