Work scheme to isolate the different micro-organisms found in hydrogen-producing reactors: a study of effectiveness by pyrosequencing analysis.

AIM: The aim of this research was to create a work scheme for the isolation of the different micro-organisms commonly found in hydrogen-producing reactors and to test its effectiveness. METHODS AND RESULTS: Methods were selected to isolate anaerobic spore-forming fermenters, anaerobic fermenters that do not form spores, facultative aerobic fermenters and lactic acid bacteria. The methods were tested in two samples taken from a hydrogen-producing reactor fed with cheese whey. 16S rRNA gene sequences from isolates were compared with pyrosequencing analysis from the same samples. The isolates represented more than 88% of the abundance detected by pyrosequencing. Organisms from the genera Clostridium, Rahnella, Megasphaera, Lactobacillus, Propionibacterium, Bifidobacterium, Chryseobacterium and Acetobacter were isolated. Hydrogen-producing capacity was confirmed for the Clostridium, Rahnella and Megasphaera isolates. Coculture experiments indicate that Megasphaera prevented the total inhibition of Clostridium by Lactobacillus. CONCLUSION: The work scheme proposed was effective to isolate most of the micro-organisms detected by pyrosequencing analysis. Physiological studies suggested a key role of Megasphaera. SIGNIFICANCE AND IMPACT OF THE STUDY: We showed the high culturability of the microbial communities from hydrogen-producing bioreactors. The isolates can be used to perform physiological studies to understand the H2 -producing process.

Effect of puerperal metritis on reproductive and productive performance in dairy cows in Argentina.

The objectives of this study were to evaluate the reproductive and productive performance of dairy cows with and without puerperal metritis and to evaluate the effectiveness of using a long-acting ceftiofur preparation. Dairy cows in one dairy farm, calving from July 2009 to January 2010, were examined between 3 and 14 days postpartum and classified on the basis of vaginal discharge into three groups: cows with normal discharge (control; C); cows with a bloody mucus purulent or pathologic nonfetid discharge (PnFD), and cows with bloody mucopurulent or purulent fetid discharge (PFD). Cows in C and PnFD groups were not treated, whereas those in the PFD group were randomly allocated to receive 2.2 mg/kg of ceftiofur subcutaneously behind the ear (PFD-T) or remain untreated (PFD-No T). From the 640 cows examined, 58.2% formed the C group, 13.4% formed the PnFD group, and 28.4% formed the PFD group. Survival curves differed between cows in the C group and PFD-No T group (P = 0.0013) and between PFD-No T versus PFD-T group (P = 0.0006). Survival curves of PnFD were intermediate and did not differ from those in the C group (P = 0.2) and PFD-T group (P = 0.1) but tended to be different from the PFD-No T group (P = 0.056). The postpartum interval to achieve a 25% pregnancy rate was 72 days for cows in the C group, 73 days for the PFD-T group, 83 days for PnFD group, and 95 days for the PFD-No T group. The chance of pregnancy in a cow in the C group was 1.98 times higher (95% confidence interval = 1.33, 3.08) and in cows in the PFD-T group was 2.16 times higher (95% confidence interval = 1.37, 3.50) than that in the PFD-No T group. Finally, the chance of pregnancy in cows in the PnFD group tended to be higher (P = 0.08) than that in the PFD-No T group but did not differ from the other two groups. Cumulative 305-day milk production was higher (P < 0.0001) in C group than those with vaginal discharge, regardless of fetidness and regardless of treatment. It is concluded that puerperal metritis affects the reproductive and productive performance of dairy cows and the treatment with ceftiofur was effective in reducing the adverse effects on reproductive performance but not on milk production.

Valorization of artichoke wastewaters by integrated membrane process.

In this work an integrated membrane system was developed on laboratory scale to fractionate artichoke wastewaters. In particular, a preliminary ultrafiltration (UF) step, based on the use of hollow fibre membranes, was investigated to remove suspended solids from an artichoke extract. The clarified solution was then submitted to a nanofiltration (NF) step. Two different 2.5 × 21 in. spiral-wound membranes (Desal DL and NP030) with different properties were investigated. Both membranes showed a high rejection towards the phenolic compounds analysed (chlorogenic acid, cynarin and apigenin-7-O-glucoside) and, consequently, towards the total antioxidant activity (TAA). On the other hand, the Desal DL membrane was characterized by a high rejection towards sugar compounds (glucose, fructose and sucrose) (100%) when compared with the NP030 membrane (4.02%). The performance of selected membranes in terms of permeate flux, fouling index and water permeability recovery was also evaluated. On the base of experimental results, an integrated membrane process for the fractionation of artichoke wastewaters was proposed. This conceptual process design permitted to obtain different valuable products: a retentate fraction (from the NP030 membrane) enriched in phenolic compounds suitable for nutraceutical, cosmeceutical or food application; a retentate fraction (from the Desal DL membrane), enriched in sugar compounds, of interest for food applications; a clear permeate (from the Desal DL membrane) which can be reused as process water or for membrane cleaning.

Microbial community composition and reactor performance during hydrogen production in a UASB reactor fed with raw cheese whey inoculated with compost.

This study investigated the microbial community developed in a UASB reactor for hydrogen production and correlated it to reactor performance. The reactor was inoculated with kitchen waste compost and fed with raw cheese whey at two organic loading rates, 20 gCOD/Ld and 30 gCOD/Ld. Hydrogen production was very variable, using an OLR of 30 gCOD/Ld averaged 1.0 LH(2)/Ld with no methane produced under these conditions. The hydrogen yield was also very variable and far from the theoretical. This low yield could be explained by selection of a mixed fermentative population with presence of hydrogen producing organisms (Clostridium, Ruminococcus and Enterobacter) and other non-hydrogen producing fermenters (Lactobacillus, Dialister and Prevotella). The molecular analysis of the raw cheese whey used for feeding revealed the presence of three predominant organisms that are affiliated with the genera Buttiauxella (a low-yield hydrogen producer) and Streptococcus (a lactic acid-producing fermenter). Although these organisms did not persist in the reactor, the continuous addition of these fermenters could decrease the reactor's hydrogen yield.

Recovery and concentration of polyphenols from olive mill wastewaters by integrated membrane system.

The purpose of this work was to analyse the potentialities of an integrated membrane system for the recovery, purification and concentration of polyphenols from olive mill wastewater (OMW). The proposed system included some well-known membrane operations such as microfiltration (MF) and nanofiltration (NF), as well as others not yet investigated for this specific application, such as osmotic distillation (OD) and vacuum membrane distillation (VMD). The OMW was directly submitted to a MF operation without preliminary centrifugation. This step allowed to achieve a 91% and 26% reduction of suspended solids and total organic carbon (TOC), respectively. Moreover, 78% of the initial content of polyphenols was recovered in the permeate stream. The MF permeate was then submitted to a NF treatment. Almost all polyphenols were recovered in the produced permeate solution, while TOC was reduced from 15 g/L to 5.6 g/L. A concentrated solution enriched in polyphenols was obtained by treating the NF permeate by OD. In particular, a solution containing about 0.5 g/L of free low molecular weight polyphenols, with hydroxytyrosol representing 56% of the total, was produced by using a calcium chloride dihydrate solution as brine. The obtained solution is of interest for preparing formulations to be used in food, cosmetic and pharmaceutical industry. Besides the OD process, VMD was applied as another way for concentrating the NF permeate and the performance of both processes was compared in terms of evaporation fluxes.

Parasites as fish population tags and pseudoreplication problems: the case of striped red mullet Mullus surmuletus in the Spanish Mediterranean.

Studies of parasites as fish population tags often apply a single round of sampling to identify potential stocks or predict harvest localities. However, the lack of replication generates pseudoreplication, implicitly assuming that infection levels are more similar between samples from the same locality than between samples from different localities. We evaluated this assumption in the case of the striped red mullet Mullus surmuletus in three localities of the Spanish Mediterranean separated by c. 300 km. Samples of 25 fish of similar size were collected in each locality in the summer and autumn of two consecutive years. Prevalence and abundance of three long-lived parasite taxa differed significantly among localities, indicating their potential as stock indicators. However, a cluster analysis (for prevalence) and a MANOVA (for abundance) indicated strong inter-sample variability, even within the same locality, with poor spatial segregation among samples. A linear discriminant analysis (LDA) based on the abundance of 17 parasite taxa correctly assigned over 80% of fish to their locality, and 95% bootstrap confidence intervals of percent classified fish per locality were narrow, indicating good and stable predictive power. However, when a LDA based on data from the first year was used to predict the locality of fish from the second year, predictive power dropped drastically (46% of correct allocation). Overall, we interpret that parasite communities of mullets change at a much lower spatial scale than that adopted in this study. This finding strongly suggests the need for proper replication to make reliable inferences about stock structure in fish populations based on parasitological data.

[The MMPI-2 test in the evaluation of the mobbing syndrome]. / Il test MMPI-2 nella valutazione della sindrome da mobbing.

MMPI-2 test is widely used in psychodiagnostic evaluation as well as in the evaluation of psychic pathologies related to psychosocial adversative events in working activities. A more efficacious use of MMPI-2 test in the working context can be achieved by the individuation of indexes able to facilitate the evaluation of mobbing syndrome. This work is based on the analysis of 150 cases (39.7% women and 60.7% men, 30 to 60 years of age), evaluated through an accurate examination of working history and a series of clinic conversations, followed by psychodiagnostic evaluation. The average of T-scores on the clinical scale, the content scale, the PK addition scale and the validation scale were calculated from tests. Pathologic high T-scores on the scales Hs, D. Hy e Pa were found in subjects having positive mobbing anamnesis. These results strongly indicate the presence of clinical specificities in workers exposed to working harassments, and that these specificities can be efficaciously evidenced by the MMPI-2 test.

Obras de estabilización de procesos erosivos en suelos loéssicos (Cárcavas) / Infraestructure for stabilization of gully erosion in loess

En el sur de la provincia de Córdoba (región central de Argentina) se encuentran numerosos arroyos afectados por procesos erosivos de carcavamiento. En este artículo en particular se presenta en caso de estudio del arroyo "El Gato", el cual cruza la Ruta Nacional Nº 8 cerca del pueblo de Sampacho. Allí se observa un severo proceso de incisión de su cauce como consecuencia del fenómeno de erosión en cárcava al que se encuentra sometido. Este fenómeno se materializa mediante la formación de un escalón en el lecho fluvial sobre el cual se desarrolla una cascada de aproximadamente 13 m de altura; presentando una fosa de socavación debido al impacto del agua. El impacto de este proceso es altamente significativo, ya que afecta negativamente su área cercana, reduciendo áreas de uso agrícola y dañando las obras de infraestructura existentes (caminos, ferrocarriles, puentes y poliductos). Asimismo, el impacto ambiental es altamente negativo, fundamentalmente por las consecuencias asociadas a la incisión del cauce, el descenso del nivel freático y el incremento del transporte de sedimentos hacia aguas abajo. En este trabajo se presentan los estudios básicos realizados para caracterizar el fenómeno y se describe la solución adoptada para estabilizar el cauce de este arroyo. Además, se presentan las modificaciones realizadas en la etapa de obra y los detalles del seguimiento durante la operación y mantenimiento de la misma (AU)

Gabapentin but not vigabatrin is effective in the treatment of acquired nystagmus in multiple sclerosis: How valid is the GABAergic hypothesis?

Acquired nystagmus occurs frequently in patients with multiple sclerosis and is often the cause of illusory motion of the environment (oscillopsia), and blurring of vision. Based primarily on the beneficial effect of gabapentin on acquired pendular nystagmus (APN), a GABAergic mechanism in controlling nystagmus has been hypothesised. If increasing GABA concentrations in the CNS are critical for the treatment of nystagmus, then a selective GABAergic drug should be highly successful. However, as gabapentin is not a selective GABAergic agent, vigabatrin, a "pure" GABAergic medication, and gabapentin, were compared in a single blind cross over trial in eight patients with definite multiple sclerosis. Patients were randomly assigned to begin with gabapentin (1200 mg daily) or vigabatrin (2000 mg daily). Neuro-ophthalmological and electro-oculographic (EOG) evaluations were performed four and three times, respectively. Treatment efficacy was based on improving visual acuity and EOG indices (amplitude or frequency of nystagmus, or both) by at least 50% of pretreatment values. Three out of eight patients dropped out due to adverse effects. In the remaining five patients gabapentin improved symptomatic pendular or gaze evoked jerk nystagmus in four. Three patients decided to continue gabapentin therapy. Importantly, vigabatrin proved useful in only one out of five patients, suggesting that gabapentin effectiveness may be related to additional non-GABAergic mechanisms of action. Interaction with cerebral glutamate transmission by inhibition of NMDA receptor might be an alternative hypothesis for the therapeutic action of gabapentin.