Greener rivers in a changing climate?—Effects of climate and hydrological regime on benthic algal assemblages in pristine streams

Excessive biomass development of benthic algae is often considered undesirable, but understanding the causes is confounded by complex interactions among driving factors. Pristine rivers allow a benchmark where human interference should be limited to climate change. In this study a time series comprising >20 years of annual benthic algae surveys from two pristine, soft water, boreal stream sites is used to determine whether year-to-year variations in benthic algal assemblages and cover were related to climate (temperature, precipitation, North Atlantic Oscillation) or hydrological regime. Total benthic algal cover ranged from 6 to 100% at Atna (the outflow of the Atna River from Lake Atnasjø), and from 3 to 50% at the headwater stream Li. Climate and hydrological regime explained 18 - 74% of the variability in benthic algal assemblages and cover. Generally, more variance was explained at Li than at Atna, possibly because (i) aquatic bryophytes blurred nutrient-mediated effects of climate and hydrology at Atna, and (ii) the upstream lake buffered hydrological variation. Temperature was more important for explaining benthic algal assemblages and cover at Atna, while hydrology was more important at Li. Climate and hydrological regime had no major impact on benthic algal taxon richness. High temperatures were associated with high benthic algal cover, particularly at Atna, while high suspended particle concentrations were associated with reduced benthic algal cover at Li, possibly due to scouring. Cover of the cyanobacterium Phormidium sp. increased at Li with increasing temperature, and decreased with prolonged periods of high discharge. Current predictions of climate change would lead to a “greener” Atna (increased cover of benthic algae), while Li would become more “bluegreen” (more Phormidium sp. but less filamentous green algae). It would also lead to a slightly more “eutrophic” algal assemblage at Atna (as indicated by the PIT-index for ecological status assessment), while a possible drift of the PIT-index is less clear at Li. The differences between Atna and Li likely reflect differences among river types, and it seems possible to make some generalizations: climate will likely affect benthic algae in lake outlets primarily via temperature, while headwater streams will primarily be affected via altered hydrology and particle concentrations.acceptedVersio

HR Policies and Maternal Labor Supply

The author asks how far the extension of employer-supported childcare serves as a driver for higher maternal labor supply. She addresses this question by categorizing employer-supported childcare as an efficiency wage introduced by the employer to increase the working volume of mothers. Applying various impact evaluation techniques in an econometric analysis, the author concludes that the availability of employer-supported childcare has a positive impact on the length and working volume of mothers who return back to work after giving birth. Furthermore, the usage of employer-supported childcare by mothers with pre-school age children influences the amount of agreed and actual working hours positively. </P

Ecological status assessment of clay rivers with naturally enhanced water phosphorus concentrations

The species composition of benthic algae changes as water phosphorus concentrations increase, and these changes can be used for ecological status assessment according to the Water Framework Directive. Natural background phosphorus concentrations in rivers and streams that are unaffected by anthropogenic impacts are usually low. Running waters draining catchments with deposits of marine clay, however, may have enhanced phosphorus concentrations, because the clay is naturally rich in apatite. Almost all clay rich areas have been cultivated for centuries, however, and fertilization has increased the soil phosphorus levels. It has, therefore, been difficult to disentangle natural from anthropogenically enhanced phosphorus in streams draining clay rich areas. We compared water phosphorus concentrations, and the Periphyton Index of Trophic Status PIT, between clay and non-clay, impacted and unimpacted rivers in Norway. We found that water phosphorus concentrations and the PIT index were higher in unimpacted clay rivers than in unimpacted non-clay rivers, indicating that natural phosphorus concentrations in clay rivers are indeed enhanced compared to rivers without deposits of marine clay. In addition, phosphate-P contributed 18–23% to total phosphorus in unimpacted clay rivers, but 33–37% in unimpacted and impacted non-clay rivers and clay rivers affected by agriculture. This indicates that the total phosphorus in unimpacted clay rivers is less bioavailable than in non-clay rivers and in impacted clay rivers. Water total phosphorus concentrations in unimpacted clay rivers significantly increased with catchment clay cover. Based on these findings, we derived new status class boundaries for the PIT index in clay rivers. Clay rivers are suggested to be assessed in only two status classes, i.e., “good or better” or “moderate or worse”, respectively. The good/moderate status class boundary for the PIT index was shown to increase with increasing catchment clay cover.publishedVersio

Metabolic engineering of the purine biosynthetic pathway in Corynebacterium glutamicum results in increased intracellular pool sizes of IMP and hypoxanthine

Background: Purine nucleotides exhibit various functions in cellular metabolism. Besides serving as building blocks for nucleic acid synthesis, they participate in signaling pathways and energy metabolism. Further, IMP and GMP represent industrially relevant biotechnological products used as flavor enhancing additives in food industry. Therefore, this work aimed towards the accumulation of IMP applying targeted genetic engineering of Corynebacterium glutamicum. Results: Blocking of the degrading reactions towards AMP and GMP lead to a 45-fold increased intracellular IMP pool of 22 mumol gCDW-1. Deletion of the pgi gene encoding glucose 6-phosphate isomerase in combination with the deactivated AMP and GMP generating reactions, however, resulted in significantly decreased IMP pools (13 mumol gCDW-1). Targeted metabolite profiling of the purine biosynthetic pathway further revealed a metabolite shift towards the formation of the corresponding nucleobase hypoxanthine (102 mumol gCDW-1) derived from IMP degradation. Conclusions: The purine biosynthetic pathway is strongly interconnected with various parts of the central metabolism and therefore tightly controlled. However, deleting degrading reactions from IMP to AMP and GMP significantly increased intracellular IMP levels. Due to the complexity of this pathway further degradation from IMP to the corresponding nucleobase drastically increased suggesting additional targets for future strain optimization

Precision medicine in Parkinson’s disease: emerging treatments for genetic Parkinson’s disease

In recent years, numerous clinical trials for disease modification in Parkinson’s disease (PD) have failed, possibly because of a “one-size-fits all” approach. Alternatively, a precision medicine approach, which customises treatments based on patients’ individual genotype, may help reach disease modification. Here, we review clinical trials that target genetic forms of PD, i.e., GBA-associated and LRRK2-associated PD. In summary, six ongoing studies which explicitely recruit GBA-PD patients, and two studies which recruit LRRK2-PD patients, were identified. Available data on mechanisms of action, study design, and challenges of therapeutic trials are discussed. Parkinson’s disease (PD) is the second most common neurodegenerative disorder, affecting more than 6 million people worldwide [1]. Numerous drugs for the treatment of PD are avilable on the market. While drugs targeting the dopaminergic pathway treat motor symptoms, there is no evidence that they modify disease progression. This “one-size-fits all” approach may very well explain why clinical trials for disease modification in PD have failed. Treatments that target the underlying pathophysiology are required. Since the pathophysiology of PD may be different in different patients, studies should be designed that assess PD treatment on a more individual basis. Therefore, a precision medicine approach in PD is very timely

A Taxonomy of Web Personalization

Web personalization has become an important way to provide individualized user experiences. As a fragmented use of the term “Web personalization” and a lack of a common framework potentially hinder the establishment of a cumulative body of research, we develop a taxonomy of Web personalization. Bringing together research from information systems, computer science, and marketing, we develop a taxonomy focusing on the meta-characteristics user modeling (with the dimensions type of data, acquisition method, and life span of data) and system adaptation (with the dimensions object, volatility, scope, and control of adaptation). We demonstrate an application of our taxonomy by analyzing a sample of articles published in premier information systems journals and present some exemplary use cases to demonstrate how the taxonomy could be applied in practical contexts

Wissenschaft in den Medien: Das Fernsehinterview

https://scholarship.law.bu.edu/clark_speakers/1072/thumbnail.jp

Procalcitonin- ein diagnostischer Parameter bei Infektionen chronisch Nierenkranker

Patienten mit chronischer Niereninsuffizienz sind einem erhöhten Infektionsrisiko ausgesetzt. Durch unterschiedliche Entzümndungsreaktionen im Organismus (durch Hämodialyse, Autoimmunerkrankung, Abstossungsreaktion) kann es schwierig sein, eine bakterielle Infektion von einem anderen Entzündungszustand abzugrenzen. Procalcitonin (PCT), ein neuer Parameter zur Diagnostik bakterieller Infektionen, zeigte sich in der vorliegenden Studie durch eine eingeschränkte Nierenfunkton nicht beeinfliusst. Lediglich die Hämodialyse bewirkte einen leichten Anstieg des Parametes. Bei systemischer bakterieller Infektion liess sich, unabhängig von der Grunderkrankung der Patienten, eine vermehrte Freisetzung von PCT nachweisen. Bei Patienten mit Autoimmunerkrankung wurden erhöhte PCT-Werte nur gefunden, wenn zusätzlich eine bakterielle Infektion bestand. Im Gegensatz dazu konnte bei autoimmunerkrankten Patienten ein kontinuierlich erhöhtes CRP beobachtet werden. PCT erwies sich als ein nützlicher Parameter für eine frühzeitige Diagnose und die Verlaufskontrolle von bakteriellen Infektionen und deren Therapie bei Patienen mit renalen Erkrankungen