Effect of crowding on the electron transfer process from plastocyanin and cytochrome c6 to photosystem I: a comparative study from cyanobacteria to green algae

Plastocyanin and cytochrome c 6, the alternate donor proteins to photosystem I, can be acidic, neutral or basic; the role of electrostatics in their interaction with photosystem I vary accordingly for cyanobacteria, algae and plants. The effect of different crowding agents on the kinetics of the reaction between plastocyanin or cytochrome c 6 and photosystem I from three different cyanobacteria, Synechocystis PCC 6803, Nostoc PCC 7119 and Arthrospira maxima, and a green alga, Monoraphidium braunii, has been investigated by laser flash photolysis, in order to elucidate how molecular crowding affects the interaction between the two donor proteins and photosystem I. The negative effect of viscosity on the interaction of the two donors with photosystem I for the three cyanobacterial systems is very similar, as studied by increasing sucrose concentration. Bovine serum albumin seems to alter the different systems in a specific way, probably by means of electrostatic interactions with the donor proteins. Ficoll and dextran behave in a parallel manner, favouring the interaction by an average factor of 2, although this effect is somewhat less pronounced in Nostoc. With regards to the eukaryotic system, a strong negative effect of viscosity is able to overcome the favourable effect of any crowding agent, maybe due to stronger donor/photosystem I electrostatic interactions or the structural nature of the eukaryotic photosystem I-enriched membrane particles.Spanish Ministry of Innovation and Science BFU2006-01361Andalusian Government PAI BIO-02

Pulsed light inactivation of mushroom polyphenol oxidase: a fluorometric and spectrophotometric study

Polyphenol oxidase (PPO) is one of the most important food enzymes, it is responsible for the browning of many foods. Pulsed light (PL) is a non-thermal method of food preservation that is able to inactivate PPO. The aim of this work was to gain insight into the mechanism of PPO inactivation by PL. To this, the kinetics of PPO inactivation by PL was measured, together with associated changes in tryptophan fluorescence, KI fluorescence quenching and turbidity; and results were analysed by parameter A and phase diagram methods. Enzyme inactivation followed the Weibull model. Tryptophan fluorescence decreased during PL treatment, as well as the parameter A, while Stern-Volmer constants increased and turbidity was constant. The phase diagram showed only two populated states. There was a high correlation between the loss of activity and parameter A. Results indicate that under the experimental conditions, the inactivation of PPO by PL is an all-or-none process where the enzyme progressively unfolds with no evidence of aggregation.Fundación Universitaria San Antonio de CartagenaCiencias de la Alimentació

Effects of Cyclodextrin Type on Vitamin C, Antioxidant Activity, and Sensory Attributes of a Mandarin Juice Enriched with Pomegranate and Goji Berries

The effects of the addition of cyclodextrins (CDs), β-CD, or HP-β-CD (1%), on the protection of antioxidant compounds of mandarin juices enriched with pomegranate extract and goji berries juice, was studied. Juices were prepared and after their thermal treatment (98 ◦C, 30 s) they were stored at 4 ◦C during 75 d. Vitamin C content, CIE L∗a∗b∗ color, antioxidant capacity, retinol equivalents, and sensory properties were studied. Losses on vitamin C were higher (6%) for juices with β-CD than juices with HP-β-CD. Retinol equivalents degradation was lower (3.4%) in juices with HP-β-cyclodextrins than in those treated with β-CD. Lower losses were observed for the instrumental and sensory color intensity in juices with HP-β-CD addition. Finally, the antioxidant capacity was also higher in juices treated with HP-β-CD. Finally, the overall sensory quality of juices with HP-β-CD was the best one after 30 d of cold storage. Even though β-CD addition did not cause any improvement compared with control juice (without CD addition), the benefits of adding HP-β-CD to this particular juice were shown in almost all parameters under study.Ciencias de la Alimentació

Retinal ganglion cell software and FPGA model implementation for object detection and tracking

This paper describes the software and FPGA implementation of a Retinal Ganglion Cell model which detects moving objects. It is shown how this processing, in conjunction with a Dynamic Vision Sensor as its input, can be used to extrapolate information about object position. Software-wise, a system based on an array of these of RGCs has been developed in order to obtain up to two trackers. These can track objects in a scene, from a still observer, and get inhibited when saccadic camera motion happens. The entire processing takes on average 1000 ns/event. A simplified version of this mechanism, with a mean latency of 330 ns/event, at 50 MHz, has also been implemented in a Spartan6 FPGA.European Commission FP7-ICT-600954Ministerio de Economía y Competitividad TEC2012-37868-C04-02Junta de Andalucía P12-TIC-130

Spatial spillovers in public expenditure on a municipal level in Spain

A key function of local governments is to provide a wide array of public services. The supply of these services has been found to create spatial spillovers among neighbouring municipalities. Although it is generally agreed that spillovers are present in models that explain government expenditures, their type—whether endogenous, exogenous or residual—and sign—whether positive or negative—remain ambiguous. In most cases, a subjective process is used to select the type of spatial regression model used in analysis, with mixed results. Per capita expenditures of ten subprogrammes (Security, Housing, Welfare, Environment, Social services, Employment promotion, Health, Education, Culture and Sport) are analysed for all Spanish municipalities with more than 5000 inhabitants in the 2010–2012 period. A Spatial Seemingly Unrelated Regression methodology in a panel framework is used to incorporate correlation between different subprogrammes and spatial dependence. Our results show that the three types of spatial effects are present. Furthermore, substantive dependence is positive in most cases, while negative residual dependence is observed in some.We gratefully acknowledge the contribution of three anonymous reviewers in helping us improve the quality of this paper. Prof. Fernando A. López , grateful for the financial support offered by the projects from Programa de Ayudas a Grupos de Excelencia de la Región de Murcia, Fundación Seneca (#19884-GERM-15) and Ministry of Economy and Competiveness (ECO2015-651758)

Live Demonstration: Retinal ganglion cell software and FPGA implementation for object detection and tracking

This demonstration shows how object detection and tracking are possible thanks to a new implementation which takes inspiration from the visual processing of a particular type of ganglion cell in the retina

Geochemical evolution of groundwater in an evaporite karst system: Brujuelo area (Jaén, Spain)

Chemical evolution of groundwater along two main flowpaths was studied in Brujuelo area, an evaporite plateau characterized by the presence of wetlands and drained by hyper-saline springs. Major ions were analyzed, saturation indexes of the main mineral species were computed, and inverse geochemical modeling was performed. Results show a relationship between elevation and water mineralization, indicating that drainage at higher altitude (brackish water) may be associated to gravity-driven flows while lower altitude springs could drain regional groundwater flows (brine water). Modeling results strongly support the hypothesis that most of the selected springs geochemically evolve in a common (S-N) flowpath.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Academic performance, class attendance and seating location of university students in practical lectures

[EN] The question of where students sit in a classroom has been widely studied under different approaches since the beginning of the 20th century. In this study, the data related to the seating location of the students in the computer-aided design practice lecture at the university were recorded and arranged, to analyse their seating preferences, their consistency throughout the course and their relationship with several factors related to academic performance, class attendance, and punctuality. In general, it was observed that students are reluctant to seat on the first row, and that the most punctual students chose to occupy the places in the first rows, closer to the lecturer (r = 0.35, p = 0.015), although this had no impact on academic performance. While the following was indeed correlated with the attendance rate: those students who attended the most class achieved a better academic performance which was reflected in the final mark (r = 0.38, p = 0.007). No difference was observed in any aspect between male and female students.Navarro Jover, JM.; Martínez Ramírez, JA. (2018). Academic performance, class attendance and seating location of university students in practical lectures. Journal of Technology and Science Education (Online). 8(4):337-345. https://doi.org/10.3926/jotse.353S3373458

Efficient DMA transfers management on embedded Linux PSoC for Deep-Learning gestures recognition: Using Dynamic Vision Sensor and NullHop one-layer CNN accelerator to play RoShamBo

This demonstration shows a Dynamic Vision Sensor able to capture visual motion at a speed equivalent to a highspeed camera (20k fps). The collected visual information is presented as normalized histogram to a CNN accelerator hardware, called NullHop, that is able to process a pre-trained CNN to play Roshambo against a human. The CNN designed for this purpose consist of 5 convolutional layers and a fully connected layer. The latency for processing one histogram is 8ms. NullHop is deployed on the FPGA fabric of a PSoC from Xilinx, the Zynq 7100, which is based on a dual-core ARM computer and a Kintex-7 with 444K logic cells, integrated in the same chip. ARM computer is running Linux and a specific C++ controller is running the whole demo. This controller runs at user space in order to extract the maximum throughput thanks to an efficient use of the AXIStream, based of DMA transfers. This short delay needed to process one visual histogram, allows us to average several consecutive classification outputs. Therefore, it provides the best estimation of the symbol that the user presents to the visual sensor. This output is then mapped to present the winner symbol within the 60ms latency that the brain considers acceptable before thinking that there is a trick.Ministerio de Economía y Competitividad TEC2016-77785-