Exoplanet detection. A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary

Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

Irreversible fouling of membrane bioreactors due to formation of a non-biofilm gel layer

Extra-cellular polymeric substances (EPS), known to contribute to fouling in membrane bio-reactors (MBRs), are generally divided into bound and free EPS. The free EPS are able to form a gel layer on the membrane active surface. The mechanisms involved in formation of such layer and its effects on performance of the MBR membranes were studied. The free EPS, extracted by centrifugation and microfiltration, contained a significant amount of humic-like substances. Under static contact to the membrane, adsorption of humic-like substances to the membrane occurred and could be explained by conventional adsorption kinetics. Due to static adsorption, surface roughness of the membrane declined significantly, indicating that adsorbed matters to the membrane filled the cavities of the membrane surface. Filtration of the free EPS caused 50% water flux decline. The fouling resistance linearly increased with the amount of the humic-like substances retained during filtration as predicted by gel growth theory. A low pressure backwash could re-establish the water flux only up to 70%.

Influence of shear on nitrification rates in a membrane bioreactor

Grundfos BioBooster (GBB) installed and operated a membrane bioreactor (MBR) test plant in 2012. During the period it became evident that the nitrification rate was lower than expected and a study was carried out to investigate the possible reasons for the observed low-nitrification rate. Tests were conducted at a pilot plant and the effect of shear from the BioBooster membrane system and the pressure reduction component on the nitrification rate was investigated. The possible effect of selection of microbial communities caused by the filtration unit was also investigated. The results revealed an unchanged nitrification rate when exposed to shear from the filtration unit and the pressure reduction component. When testing the effect of selection, the nitrification rate was also unchanged.

Comparison of nutrient-removing microbial communities in activated sludge from full-scale MBRs and conventional plants

The composition of nutrient-removing microbial communities in five full-scale membrane bioreactors (MBRs) was investigated using fluorescence in situ hybridization and 16S rRNA pyrosequencing and compared to similar analyses of conventional activated sludge (CAS) communities. The communities were highly similar but some genera that are always present in enhanced biological phosphorus removal (EBPR) (core groups) were absent in the MBRs. The overall phylogenetic similarity of the communities indicated that these differences were primarily closely related groups. More research is needed to establish the operational significance of the observed differences between MBR and CAS sludge.

The Microbial Database for Danish wastewater treatment plants with nutrient removal (MiDas-DK) - a tool for understanding activated sludge population dynamics and community stability

Since 2006 more than 50 Danish full-scale wastewater treatment plants with nutrient removal have been investigated in a project called 'The Microbial Database for Danish Activated Sludge Wastewater Treatment Plants with Nutrient Removal (MiDas-DK)'. Comprehensive sets of samples have been collected, analyzed and associated with extensive operational data from the plants. The community composition was analyzed by quantitative fluorescence in situ hybridization (FISH) supported by 16S rRNA amplicon sequencing and deep metagenomics. MiDas-DK has been a powerful tool to study the complex activated sludge ecosystems, and, besides many scientific articles on fundamental issues on mixed communities encompassing nitrifiers, denitrifiers, bacteria involved in P-removal, hydrolysis, fermentation, and foaming, the project has provided results that can be used to optimize the operation of full-scale plants and carry out trouble-shooting. A core microbial community has been defined comprising the majority of microorganisms present in the plants. Time series have been established, providing an overview of temporal variations in the different plants. Interestingly, although most microorganisms were present in all plants, there seemed to be plant-specific factors that controlled the population composition thereby keeping it unique in each plant over time. Statistical analyses of FISH and operational data revealed some correlations, but less than expected. MiDas-DK (www.midasdk.dk) will continue over the next years and we hope the approach can inspire others to make similar projects in other parts of the world to get a more comprehensive understanding of microbial communities in wastewater engineering.

XOMA 052, a potent, high-affinity monoclonal antibody for the treatment of IL-1β-mediated diseases

Interleukin-1β (IL-1β) is a potent mediator of inflammatory responses and plays a role in the differentiation of a number of lymphoid cells. In several inflammatory and autoimmune diseases, serum levels of IL-1β are elevated and correlate with disease development and severity. The central role of the IL-1 pathway in several diseases has been validated by inhibitors currently in clinical development or approved by the FDA. However, the need to effectively modulate IL-1β-mediated local inflammation with the systemic delivery of an efficacious, safe and convenient drug still exists. To meet these challenges, we developed XOMA 052 (gevokizumab), a potent anti-IL-1β neutralizing antibody that was designed in silico and humanized using Human Engineering™ technology. XOMA 052 has a 300 femtomolar binding affinity for human IL-1β and an in vitro potency in the low picomolar range. XOMA 052 binds to a unique IL-1β epitope where residues critical for binding have been identified. We have previously reported that XOMA 052 is efficacious in vivo in a diet-induced obesity mouse model thought to be driven by low levels of chronic inflammation. We report here that XOMA 052 also reduces acute inflammation in vivo, neutralizing the effect of exogenously administered human IL-1β and blocking peritonitis in a mouse model of acute gout. Based on its high potency, novel mechanism of action, long half-life, and high affinity, XOMA 052 provides a new strategy for the treatment of a number of inflammatory, autoimmune and metabolic diseases in which the role of IL-1β is central to pathogenesis.

Carbon Nanotube Free-Standing Membrane of Pt/SWNTs as Catalyst Layer in Hydrogen Fuel Cells

A simple and promising fuel-cell architecture is demonstrated using a carbon nanotube free-standing membrane (CNTFSM) made from Pt supported on purified single-walled carbon nanotubes (Pt/SWNT), which act as the catalyst layer in a hydrogen proton exchange membrane fuel cell without the need for Nafion in the catalyst layer. The CNTFSM made from Pt/SWNT at a loading of 0.082 mg Pt cm–2 exhibits higher performance with a peak power density of 0.675 W cm–2 in comparison with a commercially available E-TEK electrocatalyst made of Pt supported on XC-72 carbon black, which had a peak power density of 0.395 W cm–2 at a loading of 0.084 mg Pt cm–2 also without Nafion in the catalyst layer.

Three-dimensional analysis of mandibular growth and tooth eruption

Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth and tooth eruption in three dimensions based on computer tomography (CT) scans, extending the principles of mandibular growth analysis proposed by Björk in 1969 from two to three dimensions. As longitudinal CT data from normal children are not available (for ethical reasons), CT data from children with Apert syndrome were employed, because it has been shown that the mandible in Apert syndrome is unaffected by the malformation, and these children often have several craniofacial CT scans performed during childhood for planning of cranial and midface surgery and for follow-up after surgery. A total of 49 datasets from ten children with Apert syndrome were available for study. The number of datasets from each individual ranged from three to seven. The first CT scan in each of the ten series was carried out before 1 year of age, and the ages for the 49 scans ranged from 1 week to 14.5 years. The mandible and the teeth were segmented and iso-surfaces generated. Landmarks were placed on the surface of the mandible, along the mandibular canals, the inner contour of the cortical plate at the lower border of the symphysis menti, and on the teeth. Superimposition of the mandibles in the longitudinal series was performed using the symphysis menti and the mandibular canals as suggested by Björk. The study supported the findings of stability of the symphysis menti and the mandibular canals as seen in profile view previously reported by Björk & Skieller in 1983. However, the mandibular canals were, actually, relocated laterally during growth. Furthermore, the position of tooth buds remained relatively stable inside the jaw until root formation started. Eruption paths of canines and premolars were vertical, whereas molars erupted in a lingual direction. The 3D method would seem to offer new insight into jaw growth and tooth eruption, but further studies are needed.

Floc-forming properties of polyphosphate accumulating organisms in activated sludge

The physico-chemical characteristics of polyphosphate-accumulating organisms (PAO) involved in enhanced biological phosphorus removal (EBPR) was investigated in order to find a novel method for phosphorus recovery. If the physico-chemical characteristics of PAO are different from those of other main floc components, it may be possible to enrich PAO in bulk water or in the floc material for improved recovery of phosphorus. A combination of shear tests, chemical manipulation, and quantification of PAO by fluorescence in situ hybridization was applied. The microcolony strength of both Rhodocyclus-related PAO and Actinobacteria-related PAO was generally high as no treatment could break up more than 20% of all PAO in microcolonies. In contrast, it was possible to remove 20-40% of the organic matter and other bacterial cells by applying a high pH value or adding EDTA. With that a selective enrichment of PAO in the remaining floc material was possible. The feasibility of applying this selective PAO enrichment in flocs remains to be evaluated in full-scale plants for P-recovery.