74 research outputs found
Generalized Henneberg Stable Minimal Surfaces
We generalize the classical Henneberg minimal surface by giving
an infinite family of complete, finitely branched, non-orientable, stable
minimal surfaces in R3. These surfaces can be grouped into subfamilies
depending on a positive integer (called the complexity), which essentially
measures the number of branch points. The classical Henneberg surface
H1 is characterized as the unique example in the subfamily of the simplest
complexity m = 1, while for m ≥ 2 multiparameter families are given.
The isometry group of the most symmetric example Hm with a given
complexity m ∈ N is either isomorphic to the dihedral isometry group
D2m+2 (if m is odd) or to Dm+1 × Z2 (if m is even). Furthermore, for m
even Hm is the unique solution to the Bj¨orling problem for a hypocycloid
of m + 1 cusps (if m is even), while for m odd the conjugate minimal
surface H
∗
m to Hm is the unique solution to the Bj¨orling problem for a
hypocycloid of 2m + 2 cusps.Universidad de Granada/CBUA CEX2020-001105-M/AEI/10.13039/501100011033Ministry of Science and Innovation, Spain (MICINN)
Spanish GovernmentEuropean Commission PID2020-117868GB-I00
Junta de Andalucia P18-FR-4049
A-FQM-139-UGR1
A short version of the amyloid-like protein TasA fibrillates and supports biofilm formation in Bacillus cereus
The formation of bacterial biofilms is a doable thanks to the assembly of an extracellular matrix that provides to the entire
community with i) an outstanding architectonic structure and ii) protection to the cells from external aggressions. In
Bacillus subtilis, a structural element dedicated to the formation of the extracellular matrix is the amyloid-like protein TasA.
To form fibers, TasA needs the participation of the protein TapA. Indeed, a tapA mutant resembles phenotypically to a
tasA mutant, which is wrinkle-less pellicles or colonies with no distinguishable morphological features. tasA is widely
spread within the Bacillus genus, but tapA is absent in the heterogeneous group of Bacillus cereus which includes
environmental and pathogenic members; some of them are responsible for important food intoxication outbreaks. Then,
we asked whether TasA would still retain functionality in biofilm formation in B. cereus. Comparative genomic analysis
showed a region in B. cereus containing two orthologous of tasA, tasA and calY, and the orthologous of sipW, that
encodes a signal peptidase. Our mutagenic studies revealed that the entire region was relevant for biofilm formation, and
electron microscopy proved the major propensity of TasA than CalY to form fibers in the cell surfaces. These findings also
indicated that in B. cereus as opposed to B. subtilis, an accessory TapA protein is not necessary for the fibrillation of
TasA. Indeed, the heterologous expression of this region of B. cereus restored the capacity of a B. subtilis tasA operon
mutant or a single tasA mutant to form pellicles. These pellicles stained with the amyloid dye Congo Red and the cells
were decorated with fibers, both findings suggestive of an amyloid-like nature of the B. cereus TasA. Intriguingly, in a B.
subtilis tapA mutant, only the entire region of B. cereus fully rescued pellicle formation, fibrillation or Congo Red staining,
to a lesser extent did sipw-tasA, and no restoration was observed with sipW-calY. These observations led us to speculate
that TapA might cross seed the fibrillation of TasA or CalY in B. subtilis. In summary, TasA is relevant for biofilm formation
in these two bacterial species, which appears to be governed by its polymerizing nature. The fact that we count with two
bacterial species containing versions of TasA with subtle differences will be of great value in our studies of the
mechanistic of polymerization of these bacterial amyloid-like fibers and their contribution to the assembly of the
extracellular matrix.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Interacción del patógeno humano Bacillus cereus con plantas de interés agronómico
Uno de los grandes retos de la industria agroalimentaria es reducir los continuos casos de intoxicaciones alimentarias causadas por el consumo de frutas y verduras contaminadas con patógenos de humanos, y las consecuentes pérdidas económicas. Bacillus cereus es una bacteria patógena de humanos responsable de intoxicaciones alimentarias que en ocasiones pueden ser letales.
El ciclo de vida de esta bacteria se caracteriza por la formación de biopelículas y la esporulación. Las biopelículas son comunidades de bacterias difíciles de erradicar, y para su formación las bacterias ensamblan una matriz extracelular formada principalmente por exopolisacáridos y proteínas. En este trabajo, nos planteamos estudiar las bases moleculares que dirigen la formación de biopelículas en B. cereus, y su posible implicación en la interacción con diferentes plantas hortofrutícolas. Para ello, nos hemos centrado en el análisis de los componentes estructurales de la matriz extracelular, y más concretamente en posibles adhesinas de naturaleza proteica.
B. cereus tiene dos ortólogos del gen tasa de B. subtilis que codifica para una proteína que polimeriza en la forma de fibras amiloides y es indispensable para la formación de las biopelículas. Mediante estudios de expresión heteróloga demostramos que el alelo de tasA de B. cereus rescata la formación de biopelículas de una cepa de B. subtilis que carece de su propio tasA. De la misma forma, un mutante de B. cereus en este alelo presenta un fenotipo defectuoso en la formación de biopelículas tanto in vitro como en la interacción con plantas. Finalmente estudios bioquímicos y morfológicos preliminares de esta proteína apuntan a su naturaleza tipo amiloide como su ortólogo de B. subtilis.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Un locus ampliamente distribuido en el grupo B. cereus se encuentra implicado en la formación de biofilms
Bacillus cereus es un patógeno humano implicado en una serie de intoxicaciones alimentarias debido al consumo de verdura o comida procesada contaminada. La producción de esporas y la formación de comunidades denominadas biopelículas, son dos factores claves en la contaminación de los alimentos, la transmisión y la producción de toxinas perjudiciales para el consumidor. Durante su ciclo de vida, B. cereus es capaz de sobrevivir como saprófito, así como en asociación con una gran variedad de hospedadores: humanos, plantas e insectos.
Se piensa que la formación de comunidades bacterias posee un importante papel en la supervivencia bacteriana y adhesión a superficies. En estudios previos se han identificado dos componentes proteicos de la matriz extracelular, TasA y CalY, implicados en la formación de biopelículas en B. cereus. La región cromosómica localizada entre estas dos proteínas contiene el locus bc_1280, que se encuentra ampliamente distribuido en el grupo de B. cereus y especies relacionadas. Estudios transcriptómicos y proteómicos han demostrado que bc_1280 se encuentra sobreexpresado en células de biofilm en comparación con células plantónicas. La deleción del gen bc_1280 en las cepas B. cereus ATCC14579 y AH187 presenta un fenotipo deficiente en la formación de comunidades bacterianas. El posible papel de esta proteína en la formación de biopelículas, y su amplia distribución a lo largo del grupo B. cereus, nos ha llevado a realizar un estudio en mayor detalle para determinar la funcionalidad de este locus en la multicelularidad y la interacción con hospedadores.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Adhesin proteins in Bacillus cereus biofilms
The human pathogen Bacillus cereus is responsible for many recurrent outbreaks of food poisoning. Spores and biofilms are considered the most important reservoirs of B. cereus in contaminated fresh vegetables and fruits. Bacterial biofilms are difficult to eradicate specially due to the presence of a protective extracellular matrix made of exopolysaccharides, proteins, and other components. Amyloid-like proteins are essential for the integrity of biofilms of the related bacteria species Bacillus subtilis.
Objectives:
To investigate the presence of amyloid-like fibers in biofilms of B. cereus.
Methods:
We identified two genomic loci in B. cereus, which encode two orthologues of the amyloid-like protein TasA and a SipW signal peptidase of B. subtilis. Mutagenesis in B. cereus or heterologous expression of alleles in B. subtilis mutants combined with crystal violet staining served to evaluate the formation of biofilm. Electron microscopy let us visualize the presence of fibers on cells.
Conclusions:
We demonstrate that the proteins TasA and CalY are necessary for B. cereus biofilm formation: i) as pellicle on the air-liquid interphase or ii) adhesion to abiotic surfaces. TasA and to a lesser extent CalY polymerizes in the form of fibers in the cell surface. Our findings of heterologous expression in B. subtilis let us propose an amyloid-like nature of the B. cereus TasA-based fibersUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Efficacy of Sabila (Aloe Vera) in Electromagnetic Absorption in Households
A documentary review was carried out on the production and publication of research papers related to the study of the variables Aloe Vera and Radiation Absorption. The purpose of the bibliometric analysis proposed in this document was to know the main characteristics of the volume of publications registered in the Scopus database during the period 2012-2022, achieving the identification of 18 publications. The information provided by this platform was organized through graphs and figures categorizing the information by Year of Publication, Country of Origin, Area of Knowledge and Type of Publication. Once these characteristics have been described, the position of different authors towards the proposed theme is referenced through a qualitative analysis. Among the main findings made through this research, it is found that India, with 11 publications, was the country with the highest scientific production registered in the name of authors affiliated with institutions of that nation. The Area of Knowledge that made the greatest contribution to the construction of bibliographic material referring to the study of the variables Aloe Vera and the absorption of radiation, was Pharmacology, Toxicology and Pharmaceutical with 6 published documents, the same presented under the theories of Chemistry. The most used Type of Publication during the period indicated above were Journal Articles with 61% of the total scientific production
Profiles for identifying problematic dietary habits in a sample of recreational Spanish cyclists and triathletes
This work was supported by the research project Stance4Health funded by the European Union ' s Horizon 2020 research and innovation program (Grant Reference No. 816303) and by the Plan Propio de Investigacion y Transferencia of the University of Granada under the "Intensificacion de la Investigacion, modalidad B" program.There is a lack of sufficient information on the dietary intake and nutritional supplementation of
recreational endurance athletes throughout the year. The present observational study sought
to assess the dietary intake and nutritional supplementation habits of recreational cyclists and
triathletes from Spain. 4,037 cyclists and triathletes completed self-report measures. Nutritional
profiles were developed and differences were examined according to sporting discipline and gender.
Differences between groups were compared using the Mann–Whitney U or chi-squared test. Next,
micro- and macro-nutrients were grouped according to whether or not guideline intake amounts were
met. The clustering of dietary habits was then examined via K-means cluster analysis. Triathletes
took more supplements than cyclists (X2 = 36.489; p value = .000) and females took more supplements
than males (X2 = 5.920; p value = .017). Females and triathletes reported greater protein and CHO
consumption than males and cyclists, respectively. Triathletes also reported a higher consumption
of total fat, MUFA, PUFA, EPA, DHA and fibre. Females and triathletes tended to consume more
vitamins and minerals than males and cyclists, respectively. Two main dietary habit clusters
emerged which may be used to inform nutritional interventions targeting recreational athletes not
meeting nutritional requirements. There is an imbalance in the main nutrients making up the diet of
recreational Spanish athletes, characterised by insufficient CHO and excessive protein.research project Stance4Health - European Union 816303Plan Propio de Investigacion y Transferencia of the University of Granada under the "Intensificacion de la Investigacion, modalidad B" progra
Nutritional Habits of Professional Cyclists during Pre-Season
The first aim of the present study was to assess the dietary intake of professional cyclists during pre-season. The second aim was to assess the dietary habits of this population during a complete season. Fifteen elite male (age: 23.2 +/- 5.4 years) and twenty-three elite female (age: 20.1 +/- 7.0 years) cyclists volunteered to participate in the study. Dietary nutrient intake during pre-season was assessed using a 72 h dietary recall interview, and a 136-item food frequency questionnaire was used to assess dietary habits during the year. Protein intake exceeded the PRI's recommendation of 0.83 g/kg/day for all cycling groups. Fat exceeded RI recommendations in females in both road (43.3%) and CXO (39.8%) cycling groups, whilst males were found to follow recommendations for fat intake. CHO intake was below recommendations in all groups. Intake of all vitamins exceeded recommendations, with the exception of B9 in female road cyclists (77.8% RDA) and vitamin D in all groups. With regards to mineral intake, consumption exceeded RDA/AI recommendations in all groups except for iodine in male XCO cyclists (61.6%), female road cyclists (61.6%), and female XCO cyclists (58%) and potassium in female road cyclists (74.6%). Males consumed greater amounts of eggs and non-processed foods than females. Road cyclists consumed greater amounts of fish and seafood and had a lower intake of coffee and tea than XCO cyclists. Better knowledge of food guidelines in terms of serving and food variety is important for professional cyclists at may impact health and performance
Retos de la sociedad digital: regulación y fiscalidad en un contexto internacional
Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.Localização na estante: 336.2:004.8 R438
Development of a food composition database of different food contaminants CONT11 and estimation of dietary exposure in children of southern Spain
This work was supported by the “Plan propio de Investigaci´on y
Transferencia” of the University of Granada under the program
“Intensificaci´on de la Investigaci´on, modalidad B′′ granted to Jos´e A.
Rufi´an-Henares. This work is part of the doctoral thesis of Daniel
Hinojosa-Nogueira conducted within the context of the “Program of
Nutrition and Food Sciences” at the University of Granada.Increasing food security is one of the Sustainable Development Goals. One of the main risks in food is the increase in food contaminants. Processing methods, such as the addition of additives or heat treatment, influence contaminant generation and increase their levels in food. The aim of the present study was to create a database using a methodology similar to that of food composition databases but with a focus on potential food contaminants. CONT11 collects information on 11 contaminants: hydroxymethyl-2-furfural, pyrraline, Amadori compounds, furosine, acrylamide, furan, polycyclic aromatic hydrocarbons, benzopyrene, nitrates, nitrites and nitrosamines. This is collected for more than 220 foods obtained from 35 different data sources. A food frequency questionnaire validated for use with children was used to validate the database. Contaminant intake and exposure in 114 children aged 10–11 years were estimated. Outcomes were within the range of values described by other studies, confirming the usefulness of CONT11. This database will allow nutrition researchers to go a step further in assessing dietary exposure to some food components and the association of this with disease, whilst also informing strategies to reduce exposure.Universidad de Granad
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