Design of predictive tools to estimate freshness index in farmed sea bream (Sparus aurata) stored in ice

This research studied sea bream freshness evolution through storage time in ice by determining different quality parameters and sensory profiles. Predictive models for freshness index, storage time, and microbial counts were designed from these data. Physico-chemical parameters were assessed to evaluate the quality of fish; microbial growth was controlled to ensure food safety, and sensory analyses were carried out to characterize quality deterioration. Predictive models were developed and improved with the aim of being used as tools for quality management in the seafood industry. Validation was conducted in order to establish the accuracy of models. There was a good relationship between the physico-chemical and microbiological parameters. Sensory analysis and microbial counts allowed for the establishment of a shelf-life of 10 days, which corresponded to a poor quality (according to the European Community''s system of grading fish for marketing purposes), with a freshness index lower than 50%. Sensory profiles showed that gill and flesh texture were the most vulnerable attributes during storage in ice related to spoilage. The predictive models for the freshness index (%) and ice storage time (h) exhibited an accuracy close to 90% following practical validation

FluorMODleaf: A new leaf fluorescence emission model based on the PROSPECT model

A new model of chlorophyll a fluorescence emission by plant leaves, FluorMODleaf, is presented. It is an extension of PROSPECT, a widely used leaf optical properties model that regards the leaf as a pile of N absorbing and diffusing elementary plates. In FluorMODleaf, fluorescence emission of an infinitesimal layer of thickness dx is integrated over the entire elementary plate. The fluorescence source function is based on the excitation spectrum of diluted isolated thylakoids and on the emission spectra of isolated photosystems, PSI and PSII, which are the main pigment-protein complexes involved in the initial stages of photosynthesis. Scattering within the leaf is produced by multiple reflections within and between elementary plates. The input variables of FluorMODleaf are: the number of elementary plates N, also called leaf structure parameter, the total chlorophyll content Cab, the total carotenoid content Ccx, the equivalent water thickness Cw, and the dry matter content Cm (or leaf mass per area), as in the new PROSPECT-5, plus the σII/σI ratio referring to the relative absorption cross section of PSI and PSII, and the fluorescence quantum efficiency of PSI and PSII, τI and τII, that are introduced here as mean fluorescence lifetimes. The model, which considers the reabsorption of emitted light within the leaf, allows good quantitative estimation of both upward and downward apparent spectral fluorescence yield (ASFY) at different excitation wavelengths from 400 nm to 700 nm. It also emphasizes the role of scattering in fluorescence emission by leaves having high chlorophyll content

Influencia de los parámetros nutricionalesen cirugía de cadera

Bajo la hipótesis de que los parámetros nutricionales influyen en el desarrollo perioperatorio de la cirugía de cadera realizamos un estudio prospectivo observacional de tipo clínico sobre 100 pacientes con una edad media de 76 años. Realizamos una evaluación clínica al ingreso: talla, peso, pliegue cutáneo, circunferencia braquial y muscular. Medición de proteínas plasmáticas y linfocitos totales al ingreso, en el postoperatorio y cada 7 días. Definimos los pacientes según los valores nutricionales analíticos y clínicos. El 51% de nuestros pacientes presentaban desnutrición caloricoproteica. La media transfusional en malnutridos fue 600 c.c. frente a 350 c.c. del grupo nutrido (p < 0,05). El 73% de las complicaciones se presentaron en pacientes malnutridos. No hallamos diferencias en los períodos de sedestación y deambulación, aunque sí en la estancia hospitalaria, 15 días frente a 18,5 días (p < 0,01). La prealbúmina mostró variaciones de forma más precoz ante el acto quirúrgico.A prospective observation was conducted with the hypothesis that the nutritional situation has influence in postoperative development of hip surgery [n = 100; age 76 years (55-95)]. A nutritional evaluation was performed before surgery through the evolution of height, body weight, skin fold and braquial and muscular circunference. Serie proteins and lymphocytes levels were measured during hospital admission, in postoperative and each seven days. A 51% of patients showed protein-energy malnutrition (PEM). Transfusional haematic requirements were 600 c c . in malnutrition patients and 350 c.c. in the rest (p < 0.05). Complications appeared in PEM patients in 73% cases. The hospital stay was longer in those patients who presented PEM upon admittance (p < 0.01). Postoperatively, the prealbumin was the protein whose serie level had faster changes

Crab-meat-isolated psychrophilic spore forming bacteria inactivation by electron beam ionizing radiation

The present work was performed to evaluate the potential of electron beam ionizing radiation for the inactivation of three psychrophilic spore forming bacteria (Bacillus mycoides, Bacillus weihenstephanensis and Psychrobacillus psychrodurans) isolated from ready-to-eat brown crab (Cancer pagurus). Inactivation curves for the three spores were performed in both types of crab meat, brown and white. Also the effect of pH and water activity (aw) on the lethal efficacy of ionizing radiation, for the three different psychrophilic spore forming bacteria, was evaluated. The effects of pH, aw and their possible interactions were assessed in citrate-phosphate buffers of different pH, ranging between 7 and 4, and aw, ranging from 0.99 and 0.90, while an aw reduction from 0.90 to 0.80 had a minor impact on their resistance. In contrast to aw, the effect of pH showed a greater variability depending on the spore species. While pH did not affect the resistance of B. weihenstephanensis at any aw, B. mycoides showed slightly higher resistance at pH 5.5¿at aw of 0.90 and 0.80. pH showed a significant effect on the resistance of P. psychrodurans. For the two types of crab meat, slightly differences were observed in 6D values. B. weihenstephanensis was the most resistant, requiring 7.3–7.6¿kGy to inactivate 6 Log10-cycles of this spore forming bacterium, while for B. mycoides and P. psychrodurans 6.1–6.3 and 5.4–5.3¿kGy respectively were necessary to reach the same inactivation level in crab meat. An agreement between spore resistance in crab meats and lab media, with similar characteristics in pH and aw, was also observed. The results obtained in this research demonstrated the potential for ionizing radiation to achieve an appropriate inactivation level of spores naturally present in brown crab with the application of doses lower than 10¿kGy

Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range

An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectroradiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330-1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth

Pancreas agenesis mutations disrupt a lead enhancer controlling a developmental enhancer cluster.

Sequence variants in cis-acting enhancers are important for polygenic disease, but their role in Mendelian disease is poorly understood. Redundancy between enhancers that regulate the same gene is thought to mitigate the pathogenic impact of enhancer mutations. Recent findings, however, have shown that loss-of-function mutations in a single enhancer near PTF1A cause pancreas agenesis and neonatal diabetes. Using mouse and human genetic models, we show that this enhancer activates an entire PTF1A enhancer cluster in early pancreatic multipotent progenitors. This leading role, therefore, precludes functional redundancy. We further demonstrate that transient expression of PTF1A in multipotent progenitors sets in motion an epigenetic cascade that is required for duct and endocrine differentiation. These findings shed insights into the genome regulatory mechanisms that drive pancreas differentiation. Furthermore, they reveal an enhancer that acts as a regulatory master key and is thus vulnerable to pathogenic loss-of-function mutations