Stairs in the Architecture Notebook of Juan de Portor y Castro: An Insight into Ruled Surfaces

Historic treatises on stonecutting of the sixteenth and seventeenth centuries contributed to progress in the study and understanding of properties of the different surfaces and the intersections between them. One of the topics that contributed most towards the development of knowledge of the geometry of surfaces was the practical use of ruled surfaces. Defining the geometry of a piece of stone by surfaces that can be cut using a ruler as a guide and a check has always been considered very interesting in the field of stonecutting. This present study focuses on stairs in two Spanish treatises to illustrate how warped surfaces were treated.     

Dietary phenolics against colorectal cancer—From promising preclinical results to poor translation into clinical trials: Pitfalls and future needs

Colorectal cancer (CRC) remains a major cause of cancer death worldwide. Over 70% of CRC cases are sporadic and related to lifestyle. Epidemiological studies inversely correlate CRC incidence with the intake of fruits and vegetables but not with their phenolic content. Preclinical studies using in vitro (cell lines) and animal models of CRC have reported anticancer effects for dietary phenolics through the regulation of different markers and signaling pathways. Herein, we review and contrast the evidence between preclinical studies and clinical trials (patients with CRC or at risk, familial adenopolyposis or aberrant crypt foci) investigating the protective effects of curcumin, resveratrol, isoflavones, green tea extracts (epigallocatechin gallate), black raspberry powder (anthocyanins and ellagitannins), bilberry extract (anthocyanins), ginger extracts (gingerol derivatives), and pomegranate extracts (ellagitannins and ellagic acid). To date, curcumin is the most promising polyphenol as possible future adjuvant in CRC management. Overall, the clinical evidence of dietary phenolics against CRC is still weak and the amounts needed to exert some effects largely exceed common dietary doses. We discuss here the possible reasons behind the gap between preclinical and clinical research (inconsistence of results, lack of clinical endpoints, etc.), and provide an outlook and a roadmap to approach this topic.     

Dietary deprivation of fermented foods causes a fall in innate immune response. Lactic acid bacteria can counteract the immunological effect of this deprivation

Extrinsic factors such as maternal microbiota, bacterial load of the environment, diet and medication modulate the intestinal microbiota. Maturation and function of the immune system is influenced by established gut microbiota. In this work we describe the immunological effects of the dietary deprivation of fermented foods of healthy volunteers. Significant decreases in faecal lactobacillus and total aerobes counts and concentration of short chain fatty acids were observed following deprivation of fermented food of the normal diet. Moreover, a decrease in phagocytic activity in leukocytes was observed after two weeks of restricted diet. Therefore, the dietary deprivation of fermented foods could induce a decrease in innate immune response that might affect the capacity to respond against infections. The ingestion of a probiotic product containing the strains Lactobacillus gasseri CECT5714 and Lactobacillus coryniformis CECT5711 or a standard yogurt containing a conventional starter Lactobacillus delbrueckii sp. bulgaricus counteracted the fall in the immune response, although the probiotic product was more effective than the standard yogurt.     

Investigation on the aroma of wines from seven clones of Monastrell grapes

 Analysis of the volatile compounds of wines from seven clones of Monastrell grapes was performed using ultrasound extraction of the compounds. Significant differences were found for some of the compounds and these compounds were used in order to characterize and differentiate among the clones. Linear discriminant analysis allowed some grouping of the clones, showing that differentiation among clones of a neutral grape variety is possible. Received: 21 April 1998 / Revised version: 19 November 1998     

Volatile Metabolites of Goat Cheeses Determined by Ion Mobility Spectrometry. Potential Applications in Quality Control

Headspace sampling coupled with multi-capillary column-ion mobility spectrometry (HS-MCC-IMS) has been used for extraction and identification of some volatile metabolites from different types of goat cheese samples. The only manual operation carried out in this method was the introduction of samples into vials; the following steps (headspace generation, injection of the volatiles compounds into MCC and IMS detection) were fully automated. The analysis by MCC-IMS allowed rapid and simple differentiation of goat cheeses made with raw and pasteurized milk. MCC-IMS produced multidimensional ion mobility spectra with different retention times and intensity information different for some individual metabolites. A total of six metabolites were identified in goat cheeses including 1 alcohol (1-hexanol), 1 ketone (2-nonanone), 2 aldehydes (octanal, trans-2-heptanal) and 2 esters (ethyl butanoate and propyl butanoate). Furthermore, the evolution of one targeted metabolite (ethyl butanoate) was monitored through different ripening times (60, 150, 180, 210, 240, 270 days). These preliminary results showed that this volatile compound increased during cheese ageing according to biochemical and microbial dynamic of the matrix, and therefore ethyl butanoate could be a potential marker of ripening time in these kinds of cheese samples. Therefore, the method could be used for quality control purposes in goat cheese producers.     

A fully integrated 23.2 dBm P1 dB CMOS power amplifier for the IEEE 802.11a with 29% PAE

A two-stage fully integrated power amplifier (PA) for the 802.11a standard is presented. The PA has been fabricated using UMC 0.18 μm CMOS technology. Measurement results show a power gain of 21.1 dB, a P_1 dB of 23.2 dBm and a P_SAT of 26.8 dBm. The PAE is 29% and it is kept high by means of several integrated inductors. These inductors present low-DC resistance and high Q characteristics. The inductors must include extra design considerations in order to withstand the high-current levels flowing through them, so that they have been called power inductors.     

The Role of Parametric Assumptions in Adaptive Bayesian Estimation.

Variants of adaptive Bayesian procedures for estimating the 5% point on a psychometric function were studied by simulation. Bias and standard error were the criteria to evaluate performance. The results indicated a superiority of (a) uniform priors, (b) model likelihood functions that are odd symmetric about threshold and that have parameter values larger than their counterparts in the psychometric function, (c) stimulus placement at the prior mean, and (d) estimates defined as the posterior mean. Unbiasedness arises in only 10 trials, and 20 trials ensure constant standard errors. The standard error of the estimates equals 0.617 limes the inverse of the square root of the number of trials. Other variants yielded bias and larger standard errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early slip detection with a tactile sensor based on retina

The interest in tactile sensors is increasing as their use in complex unstructured environments is demanded, like in telepresence, minimal invasive surgery, robotics etc. The array of pressure data provided by these devices can be treated with different image processing algorithms to extract miscellaneous information. However, as in the case of vision chips or artificial retinas, problems arise when the size of the array and the computational complexity increase. Having a look at the skin, the information collected by every mechanoreceptor is not sent to the brain for its processing, but some complex pre-processing is performed to fit the limited throughput of the nervous system. This is specially important for high bandwidth demanding tasks, as the case of slip detection with tactile sensors, which is demanding in computing requirements. Here we show some results from a tactile processor based on circuitry proposed for an artificial retina that has been modified to mimic the way the biological skin works.     

Impact of pre-selected autochthonous starter cultures on the flavor quality of Iberian dry-fermented "salchichón" sausage with different ripening processes

The purpose of this study was to investigate the impact on flavor quality of 2 autochthonous starter cultures in the manufacture of Iberian dry-fermented "sálchichón." A total of 2 strains of Pediococcus acidilactici (MS200 and MS198) were combined individually with a strain of Staphylococcus vitulus (RS34) to obtain 2 starter cultures: P200S34 and P198S34. The ability of both starter cultures to implant during 2 different manufacturing procedures of "salchichón" was evaluated by 16S rRNA gene sequence analysis. Changes due to starter culture inoculations on volatile compounds were determined by gas chromatography/mass spectrometry, and the impact on flavor quality evaluated by sensorial analysis. The implantation of starter cultures was adequate and did not significantly modify the flavor of the traditional Iberian dry-fermented "salchichón," while modulating the volatile compound profile with respect to that found in sausages with wild microbial populations. The influence of the starter cultures studied was more evident in the shorter sausage processing time. P198S34 was related with the increase in some volatile compounds deriving from lipid degradation. P200S34 contributed to the formation of several volatile compounds arising from lipid degradation, amino acid catabolism, and microbial esterase activity. PRACTICAL APPLICATION: P200S34 and P198S34 are autochthonous starter cultures for specific use in the processing of Iberian dry-fermented sausages. The application of these starters allows obtaining Iberian dry-fermented sausages with sensorial characteristics standardized. It is greatly interesting for processing and marketing industry of these high-quality meat products.     

A dynamic analysis of strategies for increasing energy efficiency of refrigerators in Colombia

A dynamic model for refrigerators’ stock and replacement is proposed to analyze the evolution of refrigerators’ stock efficiency in Colombia. The model simulates changes on energy consumption of refrigerators’ stock as inefficient refrigerators are replaced at their end of life, and also voluntarily, as a result of energy efficiency strategies. Replacement rates are estimated using a diffusion model, while a discrete choice model that considers upfront and use costs is used to represent impact of energy efficiency on consumers’ decisions. The proposed model is useful for ex-ante policy analysis and design. Results from the base case scenario indicate that the current energy efficiency policy achieves a 75% penetration of high-efficiency refrigerators by 2032. The replacement of inefficient refrigerators can be accelerated by increasing access to credit to consumers; a 25% increase in households with access to credit increases voluntary replacements by 16%. Other financial incentives, such as price discounts and lower financial rates, also increase voluntary replacements, although at lower rates. To maximize the energy efficiency gains of refrigerators’ substitution, higher energy standards and removal and scrapping of old refrigerators are needed.