Effect of hydrostatic high-pressure treatment on proteins, lipids and nucleotides in chilled farmed salmon (Oncorhynchus kisutch) muscle

The effect of a previous hydrostatic high-pressure (HHP) treatment on hydrolysis, breakdown and aggregation events in chemical constituents of chilled farmed coho salmon (Oncorhynchus kisutch) was studied. Three different HHP conditions were applied (135 MPa-30 s; 170 MPa-30 s; 200 MPa-30 s; treatments T-1, T-2 and T-3, respectively) and compared to untreated fish for a 20-day chilled storage. Nucleotide degradation was important during the chilled storage in all kinds of samples; however, the K value did not afford differences related to previous pressure applied. HHP treatment led to an increased free fatty acid (FFA) formation (day 0 values); on the contrary, an inhibitory effect on FFA formation could be observed at the end of the storage (15–20 days) in T-3-treated fish as a result of microbial activity inhibition. A marked decrease in sarcoplasmic protein content was evident in samples corresponding to T-2 and T-3 treatments; the SDS–PAGE analysis of such protein fraction showed a partial loss of a band corresponding to 29 kDa. This band was excised, digested with trypsin, analysed by tandem mass spectrometry and identified as phosphoglycerate mutase.     

Technicalities of endoscopic biopsy

Despite the wealth of biopsy forceps currently available, it is obvious that there are sufficient drawbacks and shortcomings to reconsider the overall design of the endoscopic biopsy depth, the short lifespan of reusable forceps, damage to the working channel, excessive time consumption, cleaning and disinfection difficulties, etc. Improvements should be possible that approach the same degree of sophistication as is currently available in endoscopic equipment. Fully-automated, repetitive, quickly targeted biopsy sampling should be possible, but it will require the utmost technical ingenuity and expertise to achieve.     

Assessing the Usability of a Science Gateway for Medical Knowledge Bases with TRENCADIS

Biomedical applications are often built on top of knowledge bases that contain medical images and clinical reports. Currently, these bases are being used to improve diagnosis, research and teaching, but in many cases, the infrastructure required has a prohibitive cost for many medical centres. However, resources can be attached from existing e-Science infrastructures. Therefore, many efforts have been made to establish best practices that allow the use of such infrastructures. However, e-Science relies on open, distributed, collaborative environments, built on top of very specialized technologies, such as Grid and Cloud computing, which require reasonable technical skills for their usage. Therefore, science gateways have become essential tools that assist users in interacting with e-Science applications. This paper describes TRENCADIS, a technology that supports the creation and operation of virtual knowledge bases. To this end, it provides developers with components and APIs for building secure data services that can be annotated and queried through ontology templates, based on DICOM and DICOM-SR. This technology was used in this paper to build a gateway for assisting diagnosis and research in breast cancer. We also present here the results of a study conducted to evaluate the gateway, from the point of view of the usability perceived by a group of physicians and radiologists.     

Advanced neural network systems for solving complex real problems

Neural Processing Letters -     

Nonparametric estimation of conditional ROC curves: Application to discrimination tasks in computerized detection of early breast cancer

A local linear method for estimating the conditional ROC curve under the presence of continuous and categorical covariates is introduced. A data driven smoothing parameter selector based on the bootstrap is proposed. The methods are illustrated with real data from a discrimination problem emerging in the context of computer-aided diagnosis. The bootstrap approach is also used to construct pointwise confidence intervals for the area under the ROC curve.     

NADPH-diaphorase activity in the superficial layers of the superior colliculus of rats during aging

Neurons in the superficial layers of the superior colliculus are key elements in the visual system of rodents since they receive extensive afferent projections from retinal ganglion cells. The NADPH-diaphorase histochemical technique was used to detect differences in neuronal nitric oxide synthase (nNOS) in the superficial layers of the superior colliculus (sSC) of young adult (3 months) and aged (24 and 26 months) rats. The orientation of the dendritic processes of NADPH-diaphorase-positive neurons, cross-sectional area, and number of neurons per mm2 were analyzed. NADPH-d histochemistry revealed a high number of NADPH-d-positive cells in the stratum zonale and stratum griseum superficiale in adult and aged animals. NADPH-d-positive neurons were classified into the following morphological types: marginal, horizontal, pyriform, narrow-field vertical, wide-field vertical, and stellate. During aging, narrow field vertical and wide field vertical neurons present somatic atrophy and an increase in dendritic processes with dorsoventral orientation, whereas wide field vertical neurons show a decrease in those with lateromedial orientation. Marginal neurons undergo somatic hypertrophy at 26 months when compared with those at 3 months. The remaining types of neurons do not undergo size changes. Finally, the number of NADPH-d-positive neurons per mm2 in the various types of morphology does not significantly change with age. It is suggested to be likely that the aging process in the nitrergic neurons of the sSC does not lead to significant changes in the synthesis of NO from the constitutive NOS isoforms.     

Alleviating the new user problem in collaborative filtering by exploiting personality information

The new user problem in recommender systems is still challenging, and there is not yet a unique solution that can be applied in any domain or situation. In this paper we analyze viable solutions to the new user problem in collaborative filtering (CF) that are based on the exploitation of user personality information: (a) personality-based CF, which directly improves the recommendation prediction model by incorporating user personality information, (b) personality-based active learning, which utilizes personality information for identifying additional useful preference data in the target recommendation domain to be elicited from the user, and (c) personality-based cross-domain recommendation, which exploits personality information to better use user preference data from auxiliary domains which can be used to compensate the lack of user preference data in the target domain. We benchmark the effectiveness of these methods on large datasets that span several domains, namely movies, music and books. Our results show that personality-aware methods achieve performance improvements that range from 6 to 94 % for users completely new to the system, while increasing the novelty of the recommended items by 3–40 % with respect to the non-personalized popularity baseline. We also discuss the limitations of our approach and the situations in which the proposed methods can be better applied, hence providing guidelines for researchers and practitioners in the field.     

Classical versus quantum communication in XOR games

We introduce an intermediate setting between quantum nonlocality and communication complexity problems. More precisely, we study the value of XOR games when Alice and Bob are allowed to use a limited amount (c bits) of one-way classical communication compared to their value when they are allowed to use the same amount of one-way quantum communication (c qubits). The key quantity here is the ratio between the quantum and classical value. We provide a universal way to obtain Bell inequality violations of general Bell functionals from XOR games for which the previous quotient is larger than 1. This allows, in particular, to find (unbounded) Bell inequality violations from communication complexity problems in the same spirit as the recent work by Buhrman et al. (PNAS 113(12):3191–3196, 2016). We also provide an example of a XOR game for which the previous quotient is optimal (up to a logarithmic factor) in terms of the amount of information c. Interestingly, this game has only polynomially many inputs per player. For the related problem of separating the classical versus quantum communication complexity of a function, the known examples attaining exponential separation require exponentially many inputs per party.     

Using association rules to mine for strong approximate dependencies

In this paper we deal with the problem of mining for approximate dependencies (AD) in relational databases. We introduce a definition of AD based on the concept of association rule, by means of suitable definitions of the concepts of item and transaction. This definition allow us to measure both the accuracy and support of an AD. We provide an interpretation of the new measures based on the complexity of the theory (set of rules) that describes the dependence, and we employ this interpretation to compare the new measures with existing ones. A methodology to adapt existing association rule mining algorithms to the task of discovering ADs is introduced. The adapted algorithms obtain the set of ADs that hold in a relation with accuracy and support greater than user-defined thresholds. The experiments we have performed show that our approach performs reasonably well over large databases with real-world data.     

Reservoir Management in the Duero Basin (Spain): Impact on River Regimes and the Response to Environmental Change

The climatic conditions of the Iberian Peninsula result in an imbalance between water availability and demand, which is largely managed through the many dams that were built during the 20th century. However, dam operations modify the natural functioning of rivers and related subsystems. In this study we investigated the effect of reservoirs on river regimes in the Duero basin, which is one of the largest river basins in Spain. This involved calculation of a modified impoundment ratio index, and assessment of the correlations between monthly inflows and outflows. Water resources in the basin have decreased markedly during the last five decades, so we also studied how patterns of management have adapted to less water availability in the region. A significant correlation was found between the level of impoundment and the alteration of river regimes by dams. The degree of regulation was highly dependent on annual inflows into the reservoir, and consequently alterations to river regimes were more intense during dry years. The basic pattern of flow regulation involved the storage of water during winter and spring in preparation for high water demand in summer, when natural flows are low. A combination of trend and cluster analyses revealed three responses of reservoir managers to decreasing inflows during the study period: (i) for several reservoirs the level of storage was reduced; (ii) for many reservoirs, particularly those for hydropower production, the storages were increased; and (iii) for the remainder the storage levels were maintained by adjusting the outflows to the decreasing inflows. The results suggest the absence of a common approach to reservoir management, and the dominance of other interests over environmental concerns, particularly in the context of hydrological change in the basin.