Upgrading of Existing Municipal Wastewater Treatment Plants with the “Non‐Conventional Low MLSS MBR Technology”

In the future, upgrading of existing wastewater treatment plants (wwtps) will be more important than the erection of entirely new plants, as most of the plants necessary in Germany already exist. Thus far, membrane bioreactor (MBR) technology is not used as an alternative for plant upgrading in Germany. However, at several locations the preconditions indicate that the application of the MBR technology for upgrading of plants may be favorable. These preconditions include the need for a substantial enlargement of the aeration tank volume and/or the need to improve the efficiency of the final sedimentation tanks, and also require that the existing tanks be in a good state, so that the tanks can be used in the future. The relevant preconditions and the basic upgrading concept using the MBR technology were presented earlier. Depending on the local preconditions regarding the existing tank volume, a specific aspect of this application can be an operation mode using “non‐conventional low MLSS (mixed liquor suspended solids) concentrations” (5 kg MLSS/m³ through 7 kg MLSS/m³) due to the amount of the existing tank volume. Two research projects were carried out covering the operation of five pilot plants on a cubic meter scale to demonstrate the feasibility of this kind of MBR process. This paper presents the core results of this research work.     

Effectiveness of Various Small‐Scale Constructed Wetland Designs for the Removal of Iron and Zinc from Acid Mine Drainage under Field Conditions

A system of planted and unplanted small‐scale subsurface flow (SSF) and surface flow (SF) constructed wetlands together with hydroponic systems (HP) were installed to compare the removal efficiencies of Fe and Zn from acid mine drainage (AMD) under long‐term field conditions. Maximum removal of 94–97 % (116–142 mg/m² d) for Fe and 69–77 % (6.2–7.9 mg/m² d) for Zn was calculated for the planted soil systems. The planted SSF was most sensitive to heavy rain fall. Short‐term increases of the metal concentration in the outflows, short‐term breakdowns of the Fe removal and continual long‐term breakdowns of the Zn removal were observed. In contrast to Zn removal, all wetland types are applicable for Fe removal with maximum removal in the range of 60–98 %. Most of the removed Fe and Zn was transformed and deposited inside the soil bed. The amount absorbed by the plants (0.03 to 0.3 %) and gravel‐associated soil beds (0.03 to 1.7 %) of the total input were low for both metals. The response of the planted SSF to rainfall suggests a remobilization of metals accumulated inside the rhizosphere and the importance of buffering effects of the surface water layers of SF systems. The importance of plants for metal removal was shown.     

Effectiveness of Differently Designed Small‐Scale Constructed Wetlands to Decrease the Acidity of Acid Mine Drainage under Field Conditions

Constructed wetlands are a near‐natural method for the treatment of acid mine drainages (AMD). Because of the different site‐specific wastewater qualities and the variability of the used constructed wetlands regarding design, it is difficult to compare their efficiencies on the basis of literature data (often specific removal rates are missing). The AMD treatment efficiencies (pH, acidity) of differently designed planted and unplanted small‐scale constructed wetlands (subsurface flow – SSF, surface flow – SF, and hydroponic – HP systems with an area of 0.55 m² each) were compared under long‐term field conditions. The planted SF was found to be most effective, reaching mean acidity removal in the range of 80–90 %, and most resistant in view of external influences (i.e., heavy rain events). The planted SSF also showed high efficiency (50–90 %), but much more sensitivity to rain events. In both systems, the pH increased from 3.3 (mean of the inflows) to above 4.5 in the outflows. The efficiencies of the unplanted SF were insufficient and in the range of the (planted and unplanted) HP, i.e., smaller than 40 %. In general, the importance of plants for the success of the neutralization processes could be concluded.     

“Active” and “passive” ecological restoration strategies in meta‐analysis

One of the means of creating a more robust methodology for ecological restoration involves reducing the gap between ecological theory and restoration practices. A common strategy to do so is using meta‐analysis to understand key drivers of restoration outcomes. “Active” and “passive” is a dichotomy often used to separate restoration strategies in such meta‐analyses. We investigate previously raised concerns about selection bias and subjective categorization of strategies. We promote a paired experimental design in future empirical research and propose the use of three categories of restoration strategy in lieu of “passive” and “active” to alleviate inconsistency in definitions and categorization.     

A critique of the “ultra‐high risk” and “transition” paradigm

The transdiagnostic expression of psychotic experiences in common mental disorder (anxiety/depression/substance use disorder) is associated with a poorer prognosis, and a small minority of people may indeed develop a clinical picture that meets criteria for schizophrenia. However, it appears neither useful nor valid to observe early states of multidimensional psychopathology in young people through the “schizo”‐prism, and apply misleadingly simple, unnecessary and inefficient binary concepts of “risk” and “transition”. A review of the “ultra‐high risk” (UHR) or “clinical high risk” (CHR) literature indicates that UHR/CHR samples are highly heterogeneous and represent individuals diagnosed with common mental disorder (anxiety/depression/substance use disorder) and a degree of psychotic experiences. Epidemiological research has shown that psychotic experiences are a (possibly non‐causal) marker of the severity of multidimensional psychopathology, driving poor outcome, yet notions of “risk” and “transition” in UHR/CHR research are restrictively defined on the basis of positive psychotic phenomena alone, ignoring how baseline differences in multidimensional psychopathology may differentially impact course and outcome. The concepts of “risk” and “transition” in UHR/CHR research are measured on the same dimensional scale, yet are used to produce artificial diagnostic shifts. In fact, “transition” in UHR/CHR research occurs mainly as a function of variable sample enrichment strategies rather than the UHR/CHR “criteria” themselves. Furthermore, transition rates in UHR/CHR research are inflated as they do not exclude false positives associated with the natural fluctuation of dimensional expression of psychosis. Biological associations with “transition” thus likely represent false positive findings, as was the initial claim of strong effects of omega‐3 polyunsatured fatty acids in UHR samples. A large body of UHR/CHR intervention research has focused on the questionable outcome of “transition”, which shows lack of correlation with functional outcome. It may be more productive to consider the full range of person‐specific psychopathology in all young individuals who seek help for mental health problems, instead of “policing” youngsters for the transdiagnostic dimension of psychosis. Instead of the relatively inefficient medical high‐risk approach, a public health perspective, focusing on improved access to a low‐stigma, high‐hope, small scale and youth‐specific environment with acceptable language and interventions may represent a more useful and efficient strategy.     

Restoring Intertidal Boulder‐Fields as Habitat for “Specialist” and “Generalist” Animals

Restoration is important in urban areas where habitat destruction is greatest. It incorporates many levels of intervention, with creation of new habitat the most extreme form. Most research on habitat creation has been terrestrial, or in marine habitats dominated by large structuring biota, such as mangroves. Intertidal boulder‐fields in urban areas are vulnerable to disturbances and habitat loss, which adversely affect numerous habitat specialists. This study describes experiments in which quarried stones were used to create new habitat outside natural boulder‐fields as a practical approach to restoring habitat. Colonization by specialist fauna and by common algae and invertebrates was measured for a year after deployment. Despite sessile assemblages on new boulders differing from those on natural boulders, common and rare animals rapidly colonized the new habitat. There was no clear succession, but colonization was variable and patchy at all scales examined, although diversities and abundances of some species in this novel habitat matched those of natural boulders within a few months. Rare and common animals generally colonized the new habitat as adults moving in from surrounding areas. Creating new boulder‐fields using quarried rocks is a successful approach to restoration and conservation of fauna where natural boulder‐fields are threatened.     

Various strategies for obtaining artificial hemoproteins: From “hemoabzymes” to “hemozymes”

The design of artificial hemoproteins that could lead to new biocatalysts for selective oxidation reactions of organic compounds presents a huge interest especially in pharmacology, both for a better understanding of the metabolic profile of drugs and for the synthesis of enantiomerically pure molecules that could be involved in the design of drugs.The present results show that the so-called “host-guest strategy” that involves the non-covalent incorporation of anionic water-soluble iron-porphyrins into xylanase A from Streptomyces lividans, a low cost protein, leads to such an artificial hemoprotein that is able to perform the stereoselective oxidation of sulfides.     

“Inflammatory” Cytokines

If cytokines are constitutively expressed by and act on neurons in normal adult brain, then we may have to modify our current view that they are predominantly inflammatory mediators. We critically reviewed the literature to determine whether we could find experimental basis for such a modification. We focused on two "proinflammatory" cytokines, interleukin (IL)-1 and tumor necrosis factor-alpha (TNFalpha) because they have been most thoroughly investigated in shaping our current thinking. Evidence, although equivocal, indicates that the genes coding for these cytokines and their accessory proteins are expressed by neurons, in addition to glial cells, in normal brain. Their expression is region- and cell type-specific. Furthermore, bioactive cytokines have been extracted from various regions of normal brain. The cytokines' receptors selectively are present on all neural cell types, rendering them responsive to cytokine signaling. Blocking their action modifies multiple neural "housekeeping" functions. For example, blocking IL-1 or TNFalpha by several independent means alters regulation of sleep. This indicates that these cytokines likely modulate in the brain behavior of a normal organism. In addition, these cytokines are likely involved in synaptic plasticity, neural transmission, and Ca2+ signaling. Thus, the evidence strongly suggests that these cytokines perform neural functions in normal brain. We therefore propose that they should be thought of as neuromodulators in addition to inflammatory mediators.     

Dynamics of Arsenic Species in Laboratory‐Scale Horizontal Subsurface‐Flow Constructed Wetlands Treating an Artificial Wastewater

Knowledge regarding the dynamics of arsenic species and their interactions under gradient redox conditions in treatment wetlands is still insufficient. The aim of this investigation was to gain more information on the biotransformation of As and the dynamics of As species in horizontal subsurface‐flow constructed wetlands. Experiments were carried out in laboratory‐scale wetland systems, two planted with Juncus effusus and one unplanted, using an As‐containing artificial wastewater under defined organic C‐ and SO₄^2–‐loading conditions. Immobilization of As was found in all systems under conditions of limited C, mainly due to adsorption and/or co‐precipitation. The removal efficiencies were substantially higher in the planted systems (60–70 %) as compared to the unplanted system (37 % on average). Immobilization under the conditions mentioned above appeared to decrease over time in all systems. At the beginning, the dosage of organic carbon immediately caused intensive microbial dissimilatory sulfate reduction in all systems (in the range of 85–95 %) and highly efficient removal of total arsenic (81–96 % on average). Later on, in this operation period, the intensity of sulfate reduction and simultaneous removal of As decreased, particularly in the planted wetlands (ranging from 30–46 %). One reason could be the re‐oxidation of reduced compounds due to oxygenation of the rhizosphere by the emergent wetland plants (helophytes). A significant amount of reduced As [As(III)] was found in the planted systems (> 75 % of total As) during the period of efficient microbial sulfate reduction, compared to the unplanted system (> 25 % of total As). The immobilization of arsenic was found to behave more stably in the planted beds than in the unplanted bed. Both systems (planted and unplanted) were suitable to treat wastewater containing As, particularly under sulfate reducing conditions. The unplanted system seemed to be more efficient regarding the immobilization of As, but the planted systems showed a better stability of immobilized As.     

Sorting out “non‐canonical” autophagy

Canonically, LC3 lipidation has been associated with autophagy pathways but it becomes increasingly clear that this modification can also occur during autophagy‐unrelated processes. In this issue, Florey and colleagues find that the WD40 domain of ATG16L1 is dispensable for LC3 lipidation during starvation‐induced autophagy but required for its lipidation during several other membrane‐based processes that are different from autophagy. This finding opens the door for the analysis of the functions of LC3 lipidation in these pathways.     

“Laughter” and “Smile” in Barbary Macaques (Macaca sylvanus)

In an observational study on semi-free Barbary macaques it was investigated whether the phylogenetic roots of human laughter and smile can be traced back to the genus Macaca. On the basis of morphological similarity a ‘relaxed open-mouth display’ as the phylogenetic precursor of the laughter, and a ‘silent bared-teeth display’ as the possible ancestor of the smile can be distinguished in the repertory of the Barbary macaque. Behavioural sequences from focal animal protocols were analyzed in order to establish message and meaning of both displays. Relaxed open-mouth display is regularly observed in the play interactions of juveniles. It is associated with partner-directed behaviour, it is frequently answered by a relaxed open-mouth display of the receiver, and accompanied by a special vocalization. Although up to 50% of the juvenile's play partners were higher ranking than themselves voluntary participation was the rule. Most characteristically, the behaviour patterns shown by both play partners are highly symmetrical and synchronized. Silent bared-teeth display is typically accompanied by evasive or submissive body movements, and occurs primarily in dyadic interactions, mainly by the lower ranking individual. It is not an unidirectional sign of a linear dominance hierarchy, though. Silent bared-teeth display is a frequent answer to aggressive behaviour shown by the receiver. After its performance, an increase of body contact between sender and receiver was observed. Behavioural sequences of senders and receivers are complementary, but lose their asymmetry after occurrence of the display. It is concluded that these results further support Van Hooff 's (1972) view that human laughter and smile have different phylogenetic roots: while silent bared-teeth display is a signal of submission and appeasement, relaxed open-mouth display is rightly called the ‘play face’, and is an expression of fun.     

Heterogeneous Single Atom Electrocatalysis,Where “Singles” Are “Married”

There is an intensive search for heterogeneous single atom catalysts (SACs) of high activity, efficiency, durability, and selectivity for a wide variety of electrocatalytic conversion and chemical reactions, such as the hydrogen evolution reaction (HER), oxygen evolution/reduction reaction (OER and ORR), CO₂ reduction reaction (CO₂ RR), and nitrogen reduction reaction (NRR). With the downsizing from nanoparticles and clusters to single atoms, there are steady changes in the bond and coordination environment for each and every atom involved. Indeed, the single atoms in these electrocatalysts are not “singles”; they are “married” to the supporting surfaces, and their performance is controlled by the bonding and coordination with the substrate surfaces. Herein, an overview is presented on the brief history leading to the rapid development of SACs and their current status, by focusing on their synthesis, control of composition, strategies to realize single atoms with the desired bonds and coordination, and targeted performance in selected reactions. Their applications in the selected spectrum of energy conversion and chemical reactions are discussed, in relation to their structures at varying length scales down to the atomic level. A particular emphasis is placed on on‐going research activities, together with the future perspectives and particular challenges for SACs.     

Microbial Processes of Heavy Metal Removal from Carbon‐Deficient Effluents in Constructed Wetlands

This paper reviews the main microbial processes involved when toxic metals are removed from wastewater in constructed wetlands. Microbial activity is thought to play a key role in the detoxification of these metals. The paper concentrates on the microbial processes which affect the mobility, the toxicity and bioavailability of metals, namely biosorption, metal sulfide precipitation by sulfate reducers, redox transformations, and methylation, as well as microbe‐plant interactions. These reactions result in either the precipitation and accumulation of metals in wetland soils, or their volatilization and emission into the atmosphere. The possibilities of optimizing the microbially mediated reactions for the development of wetland technology are discussed as a long‐term metal retention strategy.     

Influence of Plants and Organic Matter on the Nitrogen Removal in Laboratory‐Scale Model Subsurface Flow Constructed Wetlands Inoculated with Anaerobic Ammonium Oxidizing Bacteria

Anaerobic oxidation of ammonium has become an alternative for the treatment of wastewater with high ammonium loads, and it was also suggested to be involved in the nitrogen removal process in constructed wetlands. Nonetheless, its role has not been well evaluated as yet. In this paper, results of a lab‐scale study are presented focusing on the evaluation of the role of Anammox bacteria, plants, applied ammonia, nitrite nitrogen loads, and the presence of organic matter in nitrogen transformation processes in subsurface‐flow constructed wetlands. The inoculation of the experimental model wetlands with active Anammox biomass increased the total nitrogen and ammonium removal rates to values up to 5.7 g N/m² d, which is almost 10 times higher than those values reported for subsurface flow constructed wetlands. Although the presence of plants caused a higher removal rate, the role of the plants became less important with high nitrite influent concentration. Because the unplanted experimental system without the addition of any organic carbon source showed also high nitrogen removal rates, it can be concluded that beside the potential for “conventional” denitrification in the planted systems the main mechanism for explaining the high nitrogen removal rates obtained during the experiments was the anaerobic ammonia oxidation. The assay of the formation of hydrazine from hydroxylamine and the findings of the molecular biology tests fitted with the positive results for potential Anammox activity obtained in the bottle test. The addition of organic carbon, specifically acetate, apparently had no great influence on Anammox activity, which is in agreement with the findings reported by other authors. Nevertheless, the addition influenced the redox potential. Some questions are still left open, which are mainly associated with the scaling up of these results and the inoculation of Anammox biomass in full‐scale systems.     

Tumor microenvironment as the “regulator” and “target” for gene therapy

In this review, we focus on strategies for designing functional nano gene carriers, as well as choosing therapeutic genes targeting the tumor microenvironment. Gene mutations have a great impact on the occurrence of cancer. Thus, gene therapy plays a major role in cancer therapy and has the potential to cure cancer. Well‐designed gene therapy largely relies on effective gene carriers, which can be divided into viral carriers and non‐viral carriers. A gene carrier delivers functional genes to their intracellular target and avoids nucleic acids being degraded by nucleases in the serum. Most conventional cancer gene therapies only target cancer cells and do not appear to be sufficintly efficient to pass clinical trials. Accumulating evidence has shown that extending the therapeutic strategies to the tumor microenvironment, rather than the tumor cell itself, can allow more options for achieving robust anti‐cancer efficiency. In addition, unusual features between tumor microenvironment and normal tissues, such as a lower pH, higher glutathione and reactive oxygen species concentrations, and overexpression of some enzymes, facilitate the design of smart stimuli‐responsive gene carriers regulated by the tumor microenvironment. These carriers interact with nucleic acids and then form stable nanoparticles under physiological conditions. By regulation of the tumor microenvironment, stimuli‐responsive gene carriers are able to change their properties and achieve high gene delivery efficiency. Considering the tumor microenvironment as the “regulator” and “target” when designing gene carriers and choosing therapeutic genes shows significant benefit with respect to improving the accuracy and efficiency of cancer gene therapy.