Polygenic analysis of ammonia-oxidizing bacteria using 16S rDNA, amoA, and amoB genes

Finding a unique molecular marker capable of quickly providing rigorous and useful phylogenetic information would facilitate assessing the diversity of ammonia-oxidizing bacteria in environmental samples. Since only one of several available markers can be used at a time in these kinds of studies, the 16S rDNA, amoA and amoB genes were evaluated individually and then compared in order to identify the one that best fits the information provided by the composite dataset. Distance-based neighbor-joining and maximum parsimony trees generated using the sequences of the three mentioned genes were analyzed with respect to the combined polygenic trees. Maximum parsimony trees were found to be more accurate than distance-based ones, and the polygenic topology was shown to best fit the information contained in the sequences. However, the taxonomic and phylogenetic information provided by the three markers separately was also valid. Therefore, either of the functional markers (amoA or amoB ) can be used to trace ammonia oxidizers in environmental studies in which only one gene can be targeted. [Int Microbiol 2005; 8(2):103-110

The molar extinction coefficient of bacteriochlorophyll e and the pigment stoichiometry in Chlorobium phaeobacteroides

We have determined the molar extinction coefficient of bacteriochlorophyll (BChl) e, the main light-harvesting pigment from brown-coloured photosynthetic sulfur bacteria. The extinction coefficient was determined using pure[Pr,E]BChl eF isolated by reversed-phase HPLC from crude pigment extracts of Chlorobium (Chl.) phaeobacteroides strain CL1401. The extinction coefficients at the Soret and Qy bands were determined in four organic solvents. The extinction coefficient of BChl e differs from those of other related Chlorobium chlorophylls (BChl c and BChl d) but is similar to that of chlorophyll b. The determined extinction coefficient was used to calculate the stoichiometric BChl e to BChl a and BChl e to carotenoids ratios in whole cells and isolated chlorosomes from Chl. phaeobacteroides strain CL1401 using the spectrum-reconstruction method (SRCM) described by Naqvi et al. (1997) (Spectrochim Acta A Mol Biomol Spectrosc 53: 2229–2234). In isolated chlorosomes, BChl a content was ca. 1% of the total BChl content and the stoichiometric ratio of BChl e to carotenoids was 6. In whole cells,however, BChl a content was 3–4%, owing to the presence of BChl a-containing elements, i.e. FMO protein and reaction centre. An average of 5 BChl e molecules per carotenoid was determined in whole cells.EU(Contract No FMRX–CT96–0081). Ministerio de Educación y Ciencia (Ref. BIO96–1229–002–01)Peer reviewe

Frequency response of Valencia oranges to selective harvesting by vibration

Citrus mechanical harvesting has been investigated since the 1960’s. Even though mechanical harvesting could significantly lower production costs, the implementation by the private sector has been slow. The current harvesting technologies detach the fruits with trunk, canopy or branch vibration. For late-season sweet orange varieties which simultaneously bear mature fruit, immature fruitlets and flowers shaker harvesting decreases the subsequent year’s yield. This study, investigated the frequency response of mature fruits and immature fruitlets to determine the optimum frequency range for an efficient and selective harvest. Laboratory vibration transmission tests were conducted with 14 branches bearing 76 mature fruits and 151 immature ‘Valencia’ fruitlets. The fruit and branch response to the forced vibration was measured by several sets of five triaxial accelerometers with a dynamic signal analyser. Three frequency ranges with the highest vibration transmission values were identified for mechanical harvesting lower than 10 Hz. The first frequency range (1.5-2.5 Hz) corresponded best with the most efficient vibration transmission, involving more than 90% of fruit. The second frequency range (4.5-5 Hz) successfully discriminated between mature fruit and immature fruitlets. In this frequency range, 53.4% of mature fruit amplified the acceleration a mean value of 2.2 times, while only 7.3% of immature fruitlets amplified the acceleration with a mean value of 4.4 times. The lowest third frequency range had a vibration transmission value of 7-8 Hz. The frequency response of mature citrus fruits, and their markedly higher fruit mass, were significant factors in efficient selective mechanical harvesting

Nanosecond laser photolysis studies of chlorosomes and artificial aggregates containing bacteriochlorophyll e: Evidence for the proximity of carotenoids and bacteriochlorophyll a in chlorosomes from Chlorobium phaeobacteroides strain CL1401

Time-resolved, laser-induced changes in absorbance, ΔA(λ; t), have been recorded with a view to probing pigment–pigment interactions in chlorosomes (control as well as carotenoid-depleted) and artificial aggregates of bacteriochlorophyll e (BChle). Control chlorosomes were isolated from Chlorobium phaeobacteroides strain CL1401, whose chromophores comprise BChle, bacteriochlorophyll a (BChla) and several carotenoid (Car) pigments; Car-depleted chlorosomes, from cells grown in cultures containing 2-hydroxybiphenyl. Artificial aggregates were prepared by dispersing BChle in aqueous phase in the presence of monogalactosyl diglyceride. In chlorosomes ΔA(λ; t) shows, besides a signal attributable to triplet Car (with a half-life of about 4 μs), signals in the Qy regions of both BChl. The BChla signal decays at the same rate as the Car signal, which is explained by postulating that some Car are in intimate contact with some baseplate BChla pigments, and that when a ground-state Car changes into a triplet Car, the absorption spectrum of its BChla neighbors undergoes a concomitant change (termed transient environment-induced perturbation). The signal in the Qy-region of BChle behaves differently: its amplitude falls, under reducing conditions, by more than a factor of two during the first 0.5 μs (a period during which the Car signal suffers negligible diminution), and is much smaller under nonreducing conditions. The BChle signal is also attributed to transient environment-induced perturbation, but in this case the perturber is a BChle photoproduct (probably a triplet or a radical ion). The absence of long-lived BChle triplets in all three systems, and of long-lived BChla triplets in chlorosomes, indicates that BChle in densely packed assemblies is less vulnerable to photodamage than monomeric BChle and that, in chlorosome, BChla rather than BChle needs, and receives, photoprotection from an adjacent Car.Research Council of Norway. EU (contract FMRX-CT96-0081)Peer reviewe

Determination of field capacity and yield mapping in olive harvesting using remote data acquisition

Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked in Spain and Chile using remote and autonomous equipment to determine their time efficiency and field capacity. An experimental methodology for analyzing the data to determine the field capacity and efficiency is proposed, which, along with a conventional methodology, was used to analyze the data to determine field capacity and efficiency. The results of both methodologies are compared to validate the suitability of the experimental methodology. Furthermore, a yield monitor was developed and evaluate using one of the tested olive harvesters. The results show that yield monitoring of olives is possible, but further research is needed to archieve a more reliable methodology

Olive Crown Porosity Measurement Based on Radiation Transmittance: An Assessment of Pruning Effect

Crown porosity influences radiation interception, air movement through the fruit orchard, spray penetration, and harvesting operation in fruit crops. The aim of the present study was to develop an accurate and reliable methodology based on transmitted radiation measurements to assess the porosity of traditional olive trees under different pruning treatments. Transmitted radiation was employed as an indirect method to measure crown porosity in two olive orchards of the Picual and Hojiblanca cultivars. Additionally, three different pruning treatments were considered to determine if the pruning system influences crown porosity. This study evaluated the accuracy and repeatability of four algorithms in measuring crown porosity under different solar zenith angles. From a 14 to 30 solar zenith angle, the selected algorithm produced an absolute error of less than 5% and a repeatability higher than 0.9. The described method and selected algorithm proved satisfactory in field results, making it possible to measure crown porosity at different solar zenith angles. However, pruning fresh weight did not show any relationship with crown porosity due to the great differences between removed branches. A robust and accurate algorithm was selected for crown porosity measurements in traditional olive trees, making it possible to discern between different pruning treatments

Differences in dry eye questionnaire symptoms in two different modalities of contact lens wear: silicone-hydrogel in daily wear basis and overnight orthokeratology

Purpose. To compare the ocular surface symptoms and signs in an adult population of silicone-hydrogel (Si-Hy) contact lens (CL) wearers with another modality of CL wear, overnight orthokeratology (OK). Materials and Methods. This was a prospective and comparative study in which 31 myopic subjects were fitted with the same Si-Hy CL and 23 underwent OK treatment for 3 months. Dry eye questionnaire (DEQ) was filled in at the beginning of the study and then after 15 days, 1 month, and 3 months using each CL modality. The tear quality was evaluated with noninvasive tear break-up time. Tear production was measured with Schirmer test. Tear samples were collected with Schirmer strips being frozen to analyze the dinucleotide diadenosine tetraphosphate (Ap4A) concentration with High-Performance Liquid Chromatography (HPLC). Results. After refitting with ortho-k, a reduction in discomfort and dryness symptoms at the end of the day ( < 0.05, 2 ) was observed. No significant changes were observed in Ap4A concentration in any group. Bulbar redness, limbal redness, and conjunctival staining increased significantly in the Si-Hy group ( < 0.05, Kruskal–Wallis test). Conclusion. Discomfort and dryness symptoms at the end of the day are lower in the OK CL group than in the Si-Hy CL group.The authors thank Paragon Vision Science and CooperVision for donating the lenses. This work was partially supported by the Xunta de Galicia by a predoctoral grant of the Plan I2C 2011–2015 and the Spanish SAF2013-44416-R and RETICS RD12/0034/0003. It was also partially supported by Portuguese Foundation for Science and Technology (FCT) in the framework of projects PTDC/SAU-BEB/098391/2008 and PTDC/SAU-BEB/098392/2008

Congruencia en conocimientos y educación afectivo-sexual en personas con DI

En la educación de las personas con diversidad funcional intelectual (DFI) es importante que los principales agentes implicados (usuarios/as, padres y profesionales que trabajan con ellos) posean criterios comunes acerca de los objetivos educativos en general, y especialmente, en el área de la sexualidad. Sin embargo, las tres perspectivas no siempre son coincidentes con las consecuencias que se derivan de ello. Teniendo en cuenta la importancia de la identificación de necesidades y metas comunes, planteamos este trabajo con el objetivo de conocer el grado de concordancia entre: 1) los conocimientos que los usuarios tienen sobre sexualidad y la que los padres y profesionales les atribuyen y 2) la opinión de padres, profesionales y usuarios/as sobre la necesidad de proveer/recibir educación afectivo-sexual. Para ello, 92 adultos con DI (45.6% mujeres, 54.4% hombres) con edades entre los 19 y 67 años (M=37.5) y sus padres y profesionales, completaron un instrumento donde se les preguntaba acerca del conocimiento sobre sexualidad y sobre el interés de recibir formación en educación afectivo-sexual. Los resultados señalan una concordancia respecto a los conocimientos sobre sexualidad del 36.7% entre padres y usuarios/as y del 58.4% entre profesionales y usuarios. En cuanto a la concordancia respecto a la necesidad de recibir formación en educación afectivo-sexual, ésta fue 75.5% entre padres y usuarios/as y del 88.5% entre profesionales y usuarios. La concordancia entre los tres respecto a esta cuestión resultó alta (74.7%). A partir de estos resultados podemos concluir que los profesionales son mejores conocedores de las necesidad, capacidades y conocimientos de los/as usuarios/as de lo que lo son sus propios padres pero que todos tienen en común el identificar la necesidad de introducir de forma normalizada la educación afectivo-sexual en este colectivo.In education of people with intellectual disability (ID) it is important that the main agents involved (users, parents and professionals working with them) have common criteria about educational objectives in general, and especially, in sexuality. However, the three perspectives do not always coincide with the consequences of it. Taking into account the importance of identifying common needs and goals, we propose this work with the objective of knowing the degree of agreement between: 1) the knowledge that users have about sexuality and the attribution their parents and professionals made about them and 2) the opinion of parents, professionals and users on the need to provide/receive affective-sexual education. For this, 92 adults with ID (45.6% women, 54.4% men) with ages between 19 and 67 year old (M=37.5) and their parents and professionals, completed an instrument where they were asked about knowledge about sexuality and the interest of receiving training in affective-sexual education. Results indicate agreement respect to sexuality knowledge of 36.7% between parents and users and 58.4% between professionals and users. Regarding the agreement of the need to receive training in affective-sexual education, this was 75.5% between parents and users and 88.5% between professionals and users. The agreement between the three regarding this issue was high (74.7%). From these results we can conclude that professionals are better aware of the needs, skills and knowledge of the users than their own parents are but, all have in common the identification of the need to introduce in a standardized way affective-sexual education in this group

Prevalence of and Risk Factors for Biliary Carriage of Bacteria Showing Worrisome and Unexpected Resistance Traits

Data on biliary carriage of bacteria and, specifically, of bacteria with worrisome and unexpected resistance traits (URB) are lacking. A prospective study (April 2010 to December 2011) was performed that included all patients admitted for<48 h for elective laparoscopic cholecystectomy in a Spanish hospital. Bile samples were cultured and epidemiological/clinical data recorded. Logistic regression models (stepwise) were performed using bactobilia or bactobilia by URB as dependent variables. Models (P< 0.001) showing the highest R2 values were considered. A total of 198 patients (40.4% males; age, 55.3 17.3 years) were included. Bactobilia was found in 44 of them (22.2%). The presence of bactobilia was associated (R2 Cox, 0.30) with previous biliary endoscopic retrograde cholangiopancreatography (ERCP) (odds ratio [OR], 8.95; 95% confidence interval [CI], 2.96 to 27.06; P< 0.001), previous admission (OR, 2.82; 95% CI, 1.10 to 7.24; P 0.031), and age (OR, 1.09 per year; 95% CI, 1.05 to 1.12; P< 0.001). Ten out of the 44 (22.7%) patients with bactobilia carried URB: 1 Escherichia coli isolate (CTX-M), 1 Klebsiella pneumoniae isolate (OXA-48), 3 high-level gentamicin-resistant enterococci, 1 vancomycin-resistant Enterococcus isolate, 3 Enterobacter cloacae strains, and 1 imipenem-resistant Pseudomonas aeruginosa strain. Bactobilia by URB (versus those by non-URB) was only associated (R2 Cox, 0.19) with previous ERCP (OR, 11.11; 95% CI, 1.98 to 62.47; P 0.006). For analyses of patients with bactobilia by URB versus the remaining patients, previous ERCP (OR, 35.284; 95% CI, 5.320 to 234.016; P<0.001), previous intake of antibiotics (OR, 7.200; 95% CI, 0.962 to 53.906; P 0.050), and age (OR, 1.113 per year of age; 95% CI, 1.028 to 1.206; P 0.009) were associated with bactobilia by URB (R2 Cox, 0.19; P<0.001). Previous antibiotic exposure (in addition to age and previous ERCP) was a risk driver for bactobilia by URB. This may have implications in prophylactic/therapeutic measures

Antifungal activity of extracts, essential oil and constituents from Petroselinum crispum against Colletotrichum acutatum

The effect of extracts, essential oil, and their major constituents from parsley (Petroselinum crispum (Mill.) Fuss.) against the phytopathogenic fungus Collectotrichum acutatum was evaluated by the poisoned agar method. Results showed that all extracts, along with the essential oil, significantly inhibit the radial growth of C. acutatum at concentrations higher than 100 μg mL-1. The higher activity was found for the essential oil followed by the n-hexane extract. Analysis by gas chromatography with mass spectroscopy (GC-MS) of n-hexane extract and the essential oil of P. crispum showed that the major components correspond to the phenylpropanoids myristicin and parsley-apiole. Both compounds were isolated by conventional chromatographic techniques and their structures elucidated by spectroscopicmethods. Myristicin and parsley-apiole displayed a significant inhibitory effect against C. acutatum. The highest fungistatic activity was found to parsley-apiole with IC50 value of 40 μg mL-1. In conclusion, parsley may be a good source of antifungal compounds to control C. acutatum.Se evaluó el efecto de extractos, el aceite esencial y los componentes principales del perejil (Petroselinum crispum (Mill.) Fuss.) contra el hongo fitopatógeno Collectotrichum acutatum mediante el método del agar envenenado. Los resultados mostraron que todos los extractos, junto con elaceite esencial, inhibieron significativamente el crecimiento radial de C. acutatum en concentraciones superiores a 100 μg mL-1. La mayor actividad se encontró para el aceite esencial, seguido por el extracto de n-hexano. El análisis por cromatografía de gases con espectroscopia de masas (CG-EM)del extracto de n-hexano y el aceite esencial de P. crispum mostró que los componentes principales corresponden a los fenilpropanoides miristicina y parsley-apiol. Ambos compuestos fueron aislaron por técnicas cromatográficas convencionales y sus estructuras elucidadas por métodos espectroscópicos. La miristicina y el parsley-apiol mostraron un efecto inhibidor significativo contra C. acutatum. La actividad fungistática más alta se encontró para parsley-apiol con un valor CI50 de 40 μg mL-1. Enconclusión, el perejil puede ser una buena fuente de compuestos antimicóticos para controlar el C. acutatum