Long-distance distribution of genuine energy-time entanglement

Any practical realization of entanglement-based quantum communication must be intrinsically secure and able to span long distances avoiding the need of a straight line between the communicating parties. The violation of Bell's inequality offers a method for the certification of quantum links without knowing the inner workings of the devices. Energy-time entanglement quantum communication satisfies all these requirements. However, currently there is a fundamental obstacle with the standard configuration adopted: an intrinsic geometrical loophole that can be exploited to break the security of the communication, in addition to other loopholes. Here we show the first experimental Bell violation with energy-time entanglement distributed over 1 km of optical fibres that is free of this geometrical loophole. This is achieved by adopting a new experimental design, and by using an actively stabilized fibre-based long interferometer. Our results represent an important step towards long-distance secure quantum communication in optical fibres.

Aerobic granular SBR systems applied to the treatment of industrial effluents

Four lab scale sequencing batch reactors (SBRs) were operated to remove organic matter and nitrogen from four different industrial wastewaters. The biomass grew in the reactors in the form of aerobic granules characterized by good settling properties. The high biomass concentrations achieved inside the reactors allowed reducing the solids concentration in the effluent down to 0.2 g VSS L(-1). The organic loading rates (OLR) applied to reactors ranged between 0.7 and 5.0 g CODL(-1)d(-1) with removal efficiencies of 60-95%. The nitrogen loading rates (NLR) applied varied between 0.15 and 0.65 g NH(4)(+)-NL(-1)d(-1) with variable removal efficiencies in the four systems (between 15% and 76%).

Evaluation of natural zeolite as microorganism support medium in nitrifying batch reactors: influence of zeolite particle size

An evaluation of natural zeolite as a microorganism carrier in nitrifying reactors operated in batch mode was carried out. Specifically, the influence of zeolite particle sizes of 0.5, 1.0 and 2.0 mm in diameter on microorganism adherence to zeolite, ammonium adsorption capacity and the identification of microbial populations were assessed. The greatest amount of total biomass adhered was observed for a zeolite particle size of 1 mm (0.289 g) which was achieved on the 12th day of operation. The highest ammonium adsorption capacity was observed for a zeolite particle size of 0.5 mm, which was 64% and 31% higher than that observed for particle sizes of 1.0 and 2.0 mm, respectively. The maximum de-sorption values were also found for a zeolite particle size of 0.5 mm, although when equilibrium was reached the ammonium concentrations were similar to those observed for a zeolite particle size of 1.0 mm. It was also found that the experimental data on ammonium adsorption fitted very well to the Freundlich isotherm for the three particle sizes studied. Finally, the nitrifying reactors showed similar microbial populations independently of the particle size used as microorganism carrier. The dominant bacterial community was Gammaproteobacteria making up 80% of the total population found. Betaproteobacteria were also identified and made up 12% approx. of the total population. Ammonium Oxidant Betaproteobacteria and Nitrobacter were also detected.

Aerobic granulation in a mechanical stirred SBR: treatment of low organic loads

Aerobic granular sludge was produced in a sequencing batch reactor (SBR) characterized by a height to diameter ratio of 2.5 and the use of mechanical stirring. Compact and regular aerobic granules of up to 1.75 mm of average diameter were formed in the reactor with an organic loading rate of 1.75 kg COD/(m3 d). Settling properties of the obtained aggregates were: sludge volumetric index of 30-40 mL/g VSS and settling velocity higher than 8 m/h. The effects of different carbon to nitrogen ratios (TOC/N) in the feeding on the organic matter oxidation and nitrification process were studied. The concentration of organic matter in the feeding was stepwise reduced (from 190.0 to 37.5 mg TOC/L) and ammonium increased (from 25 to 50 mg NH4+ -N/L). TOC/N ratios of 7.50, 3.00, 1.50 and 0.75 g/g in the feeding were tested. The TOC removal percentage was around 80-95% during the whole operational period and the N removal percentages obtained in the reactor were up to 40%, however, physical properties of the granules were not maintained.

Treatment of high loaded swine slurry in an aerobic granular reactor

Aerobic granular sludge grown in a sequential batch reactor was proposed as an alternative to anaerobic processes for organic matter and nitrogen removal from swine slurry. Aerobic granulation was achieved with this wastewater after few days from start-up. On day 140 of operation, the granular properties were: 5 mm of average diameter, SVI of 32 mL (g VSS)(-1) and density around 55 g VSS (L(granule))(-1). Organic matter removal efficiencies up to 87% and nitrogen removal efficiencies up to 70% were achieved during the treatment of organic and nitrogen loading rates (OLR and NLR) of 4.4 kg COD m(-3) d(-1) and of 0.83 kg N m(-3) d(-1), respectively. However, nitrogen removal processes were negatively affected when applied OLR was 7.0 kg COD m(-3) d(-1) and NLR was 1.26 kg N m(-3) d(-1). The operational cycle of the reactor was modified by reducing the volumetric exchange ratio from 50 to 6% in order to be able to treat the raw slurry without dilution.

Poverty-associated risk factors for wheezing in the first year of life in Honduras and El Salvador

BACKGROUND

Risk factors for wheezing specifically during the first year of life have been studied in well-developed countries, but the information from developing countries is very scarce. There are no such studies focusing on factors derived from poverty. The aim of the present study was to determine if risk factors related to poverty are associated to wheezing during the first year of life in infants from Honduras and El Salvador.

METHODS

A survey, using a validated questionnaire, was carried out in the metropolitan area of San Pedro Sula (Honduras) and in La Libertad (El Salvador) in centres where infants attended for a scheduled vaccination shot or a healthy child visit at 12 months of age. Fieldworkers offered questionnaires to parents and helped the illiterate when necessary. The main outcome variable was wheezing during the first year of life, as reported by parents.

RESULTS

A total of 1047 infants in El Salvador and 780 in Honduras were included in the analysis. The prevalence of wheeze in the first year was higher in El Salvador (41.2%) than in Honduras (27.7%), as was recurrent wheezing defined as three or more episodes (18.4% vs. 11.7%). Wheezing and recurrent wheezing was associated to unpaved floor in the household (summary odds ratios for both countries 1.55, p=0.036 and 1.72, p=0.054 for any wheeze and recurrent wheezing, respectively); dust entering from streets (1.30, p=0.052 and 1.67, p=0.008); living in a heavily polluted area (1.33, p=0.037 and 1.52, p=0.033); and having mould stains on the household walls (1.36, p=0.072 and 1.76, p=0.007). Furthermore, marginal associations were found for additional person at home and use of kerosene as cooking fuel. University studies in the mother (0.34, p=0.046 and 0.32, p=0.022) and a professional occupation in the father (0.34, p=0.046 and 0.26, p=0.047) were associated to a lower risk.

CONCLUSIONS

The prevalence of wheezing and recurrent wheezing is notoriously high in El Salvador and Honduras. In those populations factors related to poverty are associated to a higher prevalence of wheezing and recurrent wheezing, whereas higher maternal education and paternal professional occupation behave as protective factors.

Treatment of anaerobic sludge digester effluents by the CANON process in an air pulsing SBR

The CANON (Completely Autotrophic Nitrogen removal Over Nitrite) process was successfully developed in an air pulsing reactor type SBR fed with the supernatant from an anaerobic sludge digester and operated at moderately low temperatures (18-24 degrees C). The SBR was started up as a nitrifying reactor, lowering progressively the dissolved oxygen concentration until reaching partial nitrification. Afterwards, an inoculation with sludge containing Anammox biomass was carried out. Nitrogen volumetric removal rates of 0.25 g NL(-1)d(-1) due to Anammox activity were measured 35 d after inoculation even though the inoculum constituted only 8% (w/w) of the biomass present in the reactor and it was poorly enriched in Anammox bacteria. The maximal nitrogen removal rate was of 0.45 g NL(-1)d(-1). By working at a dissolved oxygen concentration of 0.5 mg L(-1) in the bulk liquid, nitrogen removal percentages up to 85% were achieved. The reactor presented good biomass retention capacity allowing the accumulation of 4.5 g VSS L(-1). The biomass was composed by ammonia oxidizing bacteria (AOB) forming fluffy structures and granules with an average diameter of 1.6mm. These granules were composed by Anammox bacteria located in internal anoxic layers surrounded by an external aerobic layer where AOB were placed.

Population dynamics of nitrite oxidizers in nitrifying granules

The competition between Nitrospira and Nitrobacter species was analyzed in this work under conditions of excess of nitrite. A population of nitrite oxidizing bacteria (NOB) was developed from nitrifying biomass grown as granules with a mean diameter of 0.8 mm, whose feed was switched from ammonium to nitrite. The initial population distribution of the granules was: 60% Nitrosomonas and 30% Nitrospira and it evolved to 45% Nitrobacter and 40% Nitrospira measured 177 days after the change in the feeding. The disappearance of Nitrosomonas allowed the development of an important population of Nitrobacter demonstrating that these organisms, characterized by being r strategists NOB, are poor competitors when oxygen is the limiting substrate. Interestingly, the physical structure of the granules was not altered by the change of its microbial composition during the 220 days of operation.

Post-treatment of effluents from anaerobic digesters by the Anammox process

The application of the Anammox process was studied under two different approaches for the post-treatment of anaerobic digester supernatants: two independent units, the combined SHARON-Anammox system, performed in a chemostate and a SBR, respectively, and, a single unit system composed by an air pulsing SBR to carry out the CANON process. The technology based on the combination of the SHARON-Anammox process was used to treat the effluent of an anaerobic digester from a fish canning industry. The presence of organic matter in the influent caused fluctuations in the efficiency of the SHARON unit and an optimal nitrite to ammonium ratio was not achieved in this system to feed the Anammox reactor. Nevertheless an overall percentage of nitrogen removal of 40-80% was obtained when the Anammox reactor operated at nitrite limited conditions. In those periods when the effluent from the SHARON unit contained a NO2(-)-N/NH4(+)-N molar ratio higher than 1.3 the Anammox process lost its stability due to nitrite accumulation. The effluent from an anaerobic digester placed at a WWTP was treated by a CANON system operated at room temperature (20-24 degrees C). This system was developed from a nitrifying air pulsing reactor working at limiting dissolved oxygen conditions which was inoculated with Anammox biomass. A quick start-up of the system was observed and the reactor reached a nitrogen removal rate of 0.25 g N/(L d) 40 days after inoculation. The maximum nitrogen removal rate reached 0.5 g N/(L d). These results indicate the feasibility of the treatment of effluents from psychrophilic anaerobic digesters using the Anammox process.

Influence of gas flow-induced shear stress on the operation of the Anammox process in a SBR

The start up and performance of the Anammox process were tested in sequencing batch reactors with two different configurations: a bubble column (SBR-B) and a gas-lift reactor (SBR-G). Different off-gas upflow velocities were tested (3.53-12.3 cm min(-1)) in order to expose the biomass to different shear conditions and to study their effects on both efficiency and physical properties of the Anammox granular biomass. For the SBR-B the minimum gas upflow velocity needed to achieve biomass suspension inside the reactor was 12.3 cm min(-1). Such velocity made impossible the stable operation of the process. The fluidization of biomass for the SBR-G was reached at a gas upflow velocity of 3.52 cm min(-1). This system maintained an efficiency of nitrite removal around 98% at values up to 5.29 cm min(-1) but when the gas upflow velocity was increased from 5.29 to 9.70 cm min(-1) a significant decrease of the specific Anammox activity of the biomass from 0.35 to 0.05 g Ng(-1) VSS d(-1) was measured. The system lost 85% of its nitrogen removal efficiency which was not restored in spite of returning the gas upflow velocity to its initial value.

Treatment of saline wastewater in SBR aerobic granular reactors

Fish canning effluents characterized by their salt content, up to 30 g NaCl/L, were treated, previously diluted to desired concentration, in a SBR where aerobic granular sludge was produced. The formation of mature aerobic granules occurred after 75 days of operation with 3.4 mm of diameter, SVI of 30 mL/g VSS and density around 60 g VSS/L-granule. Treated organic loading rates were up to 1.72 kg COD/(m3.d) with fully organic matter depletion. Ammonia nitrogen was removed via nitrification-denitrification up to 40% when nitrogen loading rates were of 0.18 kg N/(m3.d). The presence of salt in the treated effluent did not cause a detrimental effect on the operation of the reactor once the aerobic granules were formed.

A double-blind placebo controlled trial of etanercept in patients with giant cell arteritis and corticosteroid side effects

OBJECTIVE

Open label studies have suggested that tumour necrosis factor (TNF) antagonists led to sustained improvement and corticosteroid sparing effect in patients with giant cell arteritis (GCA). To confirm these observations, we conducted a randomised, double-blind, placebo controlled trial with etanercept in patients with biopsy-proven GCA with side effects secondary to corticosteroids.

METHODS

We randomly assigned patients with GCA to receive etanercept (n = 8) or placebo (n = 9) over 1 year together with corticosteroids that were reduced according to a predefined schedule. The primary outcome was the ability to withdraw the corticosteroid therapy and control the disease activity at 12 months.

RESULTS

Baseline characteristics were similar in the two groups, although patients in the etanercept group showed higher levels of basal glycaemia (p = 0.02) and a higher erythrocyte sedimentation rate (ESR) (p = 0.01). After 12 months, 50% of the patients in the etanercept group and 22.2% in the placebo group were able to control the disease without corticosteroid therapy (p value not significant). Patients in the etanercept group had a significant lower dose of accumulated prednisone during the first year of treatment (p = 0.03). There were no differences in the number and type of adverse events.

CONCLUSION

The limited number of patients included in this study does not allow us to draw definitive conclusions. Etanercept therapy was well tolerated in this aged population. The therapeutic role of etanercept in patients with GCA should be evaluated in studies with a larger number of patients.

[Colostomy morbidity in children with anorectal malformations (ARM)]

OBJECTIVE

To describe the incidence and type of complications presented in the patients with ARM treated with a colostomy.

MATERIAL AND METHODS

The patients data with diagnostic of ARM and colostomy beetween 1994 and 2005 were revised.

RESULTS

The colostomy was carried out in other centers in 185 patients (75.2%) and in our institution in 61 (24.8%). Two hundred eleven (85.8%) had a sigmoid colostomy. Only 124 patients had a diverting colostomy. Sigmoid colon was erroneously used as transverse in 2 cases. The space among the ostomies was very scarce in 10 and excessive in 5. The colostomy complications were retraction in 7, prolapse in 7, closure of the distal opening in 5, proximal stenosis in 3, ostomy necrosis in 1 and the paraostomal hernia in 2. Complications related to the colostomy closure were intestinal occlusion in 1, abscess of abdominal wall in 1 and incisional hernia in 2.

CONCLUSIONS

The colostomy morbidity in patients with ARM is flashy. This procedure should not be considered a procedure of little complexity by the implications that has in the treatment of the patients with ARM.

[Ladd laparoscopic procedure in the neonate]

The treatment of the intestinal malrotation with or without midgut volvulus with the Ladd procedure for laparoscopic way has been proposed by several authors since 1995. We carry out this treatment in a patient of 15 days old with intestinal malrotation and midgut volvulus. After clinical and radiologic diagnosis, the procedure consisted in the careful counterclock reduction of the volvulus, division of the Ladd's bands, incision of the common mesentery and appendectomy. The jejunum and ileum was positioned on the rigth and the colon on the left in the abdominal cavity. The postoperative evolution was appropiate. We recommend the laparoscopic Ladd's procedure like an alternative in the patients with midgut volvulus that fulfill minimum approaches during the preoperative study that allow to carry out the surgery with security.