Global Dam Watch: curated data and tools for management and decision making

Dams, reservoirs, and other water management infrastructure provide benefits, but can also have negative impacts. Dam construction and removal affects progress toward the UN sustainable development goals at local to global scales. Yet, globally-consistent information on the location and characteristics of these structures are lacking, with information often highly localised, fragmented, or inaccessible. A freely available, curated, consistent, and regularly updated global database of existing dams and other instream infrastructure is needed along with open access tools to support research, decision-making and management needs. Here we introduce the Global Dam Watch (GDW) initiative (www.globaldamwatch.org ) whose objectives are: (a) advancing recent efforts to develop a single, globally consistent dam and instream barrier data product for global-scale analyses (the GDW database); (b) bringing together the increasingly numerous global, regional and local dam and instream barrier datasets in a directory of databases (the GDW directory); (c) building tools for the visualisation of dam and instream barrier data and for analyses in support of policy and decision making (the GDW knowledge-base) and (d) advancing earth observation and geographical information system techniques to map a wider range of instream structures and their properties. Our focus is on all types of anthropogenic instream barriers, though we have started by prioritizing major reservoir dams and run-of-river barriers, for which more information is available. Our goal is to facilitate national-scale, basin-scale and global-scale mapping, analyses and understanding of all instream barriers, their impacts and their role in sustainable development through the provision of publicly accessible information and tools. We invite input and partnerships across sectors to strengthen GDW’s utility and relevance for all, help define database content and knowledge-base tools, and generally expand the reach of GDW as a global hub of impartial academic expertise and policy information regarding dams and other instream barriers

Associations between aerobic fitness, negative symptoms, cognitive deficits and brain structure in schizophrenia - a cross-sectional study

Negative symptoms and cognitive deficits are common in individuals with schizophrenia, greatly affect their outcome, and have been associated with alterations in cerebral gray and white matter volume (GMV, WMV). In the last decade, aerobic endurance training has emerged as a promising intervention to alleviate these symptoms and improved aerobic fitness has been suggested as a key moderator variable. In the present study, we investigated, whether aerobic fitness is associated with fewer cognitive deficits and negative symptoms and with GMVs and WMVs in individuals with schizophrenia in a cross-sectional design. In the largest study to date on the implications of fitness in individuals with schizophrenia, 111 participants at two centers underwent assessments of negative symptoms, cognitive functioning, and aerobic fitness and 69 underwent additional structural magnetic resonance imaging. Multilevel Bayesian partial correlations were computed to quantify relationships between the variables of interest. The main finding was a positive association of aerobic fitness with right hippocampal GMV and WMVs in parahippocampal and several cerebellar regions. We found limited evidence for an association of aerobic fitness with cognitive functioning and negative symptoms. In summary, our results strengthen the notion that aerobic fitness and hippocampal plasticity are interrelated which holds implications for the design of exercise interventions in individuals with schizophrenia

Association between aerobic fitness and the functional connectome in patients with schizophrenia

BACKGROUND: Schizophrenia is accompanied by widespread alterations in static functional connectivity associated with symptom severity and cognitive deficits. Improvements in aerobic fitness have been demonstrated to ameliorate symptomatology and cognition in people with schizophrenia, but the intermediary role of macroscale connectivity patterns remains unknown. OBJECTIVE: Therefore, we aim to explore the relation between aerobic fitness and the functional connectome in individuals with schizophrenia. Further, we investigate clinical and cognitive relevance of the identified fitness-connectivity links. METHODS: Patients diagnosed with schizophrenia were included in this cross-sectional resting-state fMRI analysis. Multilevel Bayesian partial correlations between aerobic fitness and functional connections across the whole brain as well as between static functional connectivity patterns and clinical and cognitive outcome were performed. Preliminary causal inferences were enabled based on mediation analyses. RESULTS: Static functional connectivity between the subcortical nuclei and the cerebellum as well as between temporal seeds mediated the attenuating relation between aerobic fitness and total symptom severity. Functional connections between cerebellar seeds affected the positive link between aerobic fitness and global cognition, while the functional interplay between central and limbic seeds drove the beneficial association between aerobic fitness and emotion recognition. CONCLUSION: The current study provides first insights into the interactions between aerobic fitness, the functional connectome and clinical and cognitive outcome in people with schizophrenia, but causal interpretations are preliminary. Further interventional aerobic exercise studies are needed to replicate the current findings and to enable conclusive causal inferences. TRIAL REGISTRATION: The study which the manuscript is based on is registered in the International Clinical Trials Database (ClinicalTrials.gov identifier [NCT number]: NCT03466112) and in the German Clinical Trials Register (DRKS-ID: DRKS00009804). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00406-022-01411-x

Gelöste organische Substanz in Wäldern mit unterschiedlichem Management

Dissolved organic matter (DOM) represents one of the most dynamic fractions of organic matter. It plays an important role in the biogeochemical cycles of carbon and nutrients, which in turn is strongly affected by its chemical quality. This thesis aims to improve the understanding of DOM quality and its changes along the water flow path through forested Mid-European ecosystems, as they are influenced by forest management. I hypothesized that (i) the composition and (ii) the biodegradability of DOM changes systematically along the water flow path through different compartments (throughfall, stemflow, litter leachate, mineral topsoil and subsoil solution), whereby DOM quality as well as the direction and magnitude of its changes depend on forest management practice. These include vegetation cover and intensity of management activity. These hypotheses were tested using samples from forest plots of the German “Biodiversity Exploratories”, which were located in three different regions of Germany (Schwäbische Alb, Hainich-Dün and Schorfheide-Chorin) and comprised age-class coniferous stands as well as age-class and unmanaged beech forests. The chemical and optical DOM properties were investigated with UV-vis and fluorescence spectroscopy as well as FT-ICR MS measurements, while DOM bioavailability was examined with an incubation experiment. These investigations were accompanied by an evaluation of the effects of sample preservation on dissolved organic carbon (DOC) concentration and DOM composition, which showed that freezing and thawing affected the DOC concentration, as well as spectral absorption and fluorescence DOM properties of all compartments. However, since all sample types were equally affected, it was possible to consider the under- or overestimations, caused by the storage protocol, when interpreting the results of DOM quality characterization. Throughfall showed the highest amount of protein-related substances and contained the lowest amounts of aromatic compounds. Decreasing amounts of protein-related constituents and increasing shares of aromatic compounds were detected when following the water via stemflow to litter leachate. Results of the biodegradability experiment confirmed that the increase of aromaticity was due to microbial processing, i.e. the preferential degradation and assimilation of non-aromatic compounds. After percolating further downward and passing organic soil layers, DOM of subsoil solution showed decreasing DOC concentration and decreasing amounts of aromatic components, likely due to preferential adsorption of the latter. The remaining DOM was characterized by an accumulation of products of microbial lignin degradation and other refractory compounds. DOM quality and DOC concentration differed between coniferous and beech forest stands for above ground samples. Following the water flow path below ground, DOM properties converged and vegetation-related differences disappeared. Apart from this tree-species effect, management categories like unmanaged and age-class beech forests, as well as established indices of forest management intensity had no statistically significant influence on DOM properties and DOC concentration. This thesis confirmed that DOM composition and bioavailability of forested ecosystems changes systematically along the water flow path from the canopy through organic soil layers to the subsoil. While properties of DOM in throughfall and stemflow samples differ between dominant tree species (coniferous trees versus beech trees), these differences disappear along the flow path belowground most likely as a consequence of microbial processing and interactions with the mineral soil. Hence, a better quantitative understanding of microbial generation and processing as well as sorption of DOM fractions in different soils might be necessary to identify effects of a management intensity on DOM quality and quantity. The suitability of DOM as indicator of management effects on carbon cycling in forests is limited by the multitude of factors that affect its quantity and quality.Gelöste organische Substanz (DOM) repräsentiert eine der dynamischsten Fraktion von organischem Material. Sie spielt eine wichtige Rolle im biogeochemischen Kreislauf von Kohlenstoff und anderen Nährstoffen. Diese Rolle wird wiederum durch die DOM Qualität, also ihre chemische Zusammensetzung und Bioverfügbarkeit, beeinflusst. Ziel dieser Arbeit ist es, unser Verständnis über die Qualität von gelöster organischer Substanz und deren Änderung entlang des Wasserpfades in einem europäischen Waldökosystem zu vertiefen, sowie den Einfluss, den das Waldmanagement darauf ausübt, zu untersuchen. Es wurden die folgenden Hypothesen getestet: i) Die Zusammensetzung und ii) die Bioverfügbarkeit von DOM ändert sich systematisch entlang des Wasserweges durch unterschiedliche Schichten des Waldes, über Bestandsniederschlag und Stammabfluss, durch die Streuschicht hin durch mineralischen Ober- und Unterboden, wobei nicht nur die Qualität, sondern auch die Richtung und das Ausmaß der Änderung vom Waldmanagement abhängen. Dieses umfasst sowohl die Auswahl verschiedener Baumarten, als auch die Intensität der Bewirtschaftung. Die Proben zur Prüfung der Hypothesen wurden auf ausgewählten Waldflächen der „Exploratorien zur funktionellen Biodiversitätsforschung“ der DFG gewonnen. Diese befinden sich in drei Regionen Deutschlands und umfassen sowohl Altersklassenwälder als auch unbewirtschaftete Buchenwälder. Die chemischen und optischen Eigenschaften von DOM wurden mittels UV-vis - und Fluoreszenzsspektrometrie, sowie mit hochauflösender FT-ICR Massenspektrometrie untersucht, während zur Bestimmung der Bioverfügbarkeit ein Inkubationsversuch durchgeführt wurde. Begleitend zu der Charakterisierung wurde der Einfluss der Probenlagerung auf die DOM Zusammensetzung und Konzentration untersucht. Diese Methodenvalidierung zeigte, dass das Einfrieren der Proben die Konzentration sowie die Absorptions- und Fluoreszenzeigenschaften der DOM in allen untersuchten Proben beeinflusste. Da jedoch alle untersuchten Variablen unabhängig von der Waldschicht in gleicher Weise beeinflusst wurden, ist es möglich die Über- oder Unterschätzungen der einzelnen Parameter durch das Einfrieren bei der Interpretation von Änderungen der DOM-Qualität zu berücksichtigen. Der Bestandsniederschlag zeigte den höchsten Anteil proteinhaltiger und den geringsten Anteil an aromatischer DOM. Entlang des Wasserfließpfades über den Stammabfluss in die Streuschicht nahm der Anteil der Ersteren ab und der Zweiteren zu. Der Inkubationsversuch mit inokulierten Lösungsproben zeigt, dass die Zunahme der Aromatizität des DOM auf einem präferenziellen biologischen Abbau nicht-aromatischer Verbindungen beruht. Nach dem Bodeneintritt und dem Durchfließen von organischen Bodenschichten, zeigte die Mineralbodenlösung wieder eine Abnahme von aromatischen DOM-Bestandteilen, was wahrscheinlich auf deren selektiver Sorption an mineralischen Bodenbestandteilen zurückzuführen ist. Die verbleibende DOM zeigte eine Anreicherung von Lignin-Abbauprodukten und anderen refraktären Bestandteilen. Die DOM-Qualität und –Konzentration unterschied sich zwischen Nadel- und Buchenwäldern für oberirdische Probentypen. Im Boden verschwanden diese Unterschiede wieder. Statistisch signifikante Unterschiede zwischen der Zusammensetzung von DOM aus unterschiedlich bewirtschafteten Wäldern einer Baumart konnten nicht festgestellt werden. Diese Arbeit bestätigt, dass sich Quantität und Qualität von DOM entlang des Wasserfließweges durch Waldökosysteme systematisch verändern. Während die Qualität und Konzentration von DOM in Bestandsniederschlag und Stammabfluss signifikant durch die Hauptbaumart (Nadelbaum versus Buche) beeinflusst wird, verschwinden diese Unterschiede auf dem Weg durch den Boden, wahrscheinlich aufgrund der mikrobiellen Umsetzung und der Interaktion von DOM mit dem Mineralboden. Ein besseres Verständnis der mikrobiellen Produktion und Umsetzung aber auch der Sorption von DOM in verschiedenen Böden scheint eine Voraussetzung zur Aufklärung des Effektes von Management auf DOM zu sein. Die Eignung von DOM als Indikator für Managementeffekte auf den Kohlenstoffkreislauf von Wäldern wird durch die Vielzahl von Faktoren begrenzt, die seine Konzentration und Zusammensetzung beeinflussen.DFG, SPP 1374, Elementkreisläufe in Wäldern und Grünländern der Biodiversitäts-Exploratorien: Reaktion auf Managementintensität und Biodiversität/BECycle

Analysis: Leitidee Zuordnung und Veränderung

vom Hofe R, Lotz J, Salle A. Analysis: Leitidee Zuordnung und Veränderung. In: Bruder R, Hefendehl-Hebeker L, Schmidt-Thieme B, Weigand H-G, eds. Handbuch der Mathematikdidaktik. 1st ed. Berlin, Heidelberg: Springer Berlin Heidelberg; 2015: 149-184.Das Denken in Zuordnungen und Veränderungen durchzieht die gesamte Mathematik vom Kindergarten bis zur Universität. Es findet seine wichtigste Konkretisierung im Funktionsbegriff und sein interessantestes Anwendungsfeld in der Analysis. Die Idee des funktionalen und die des infinitesimalen Denkens bilden daher die Leitlinien dieses Kapitels. Im ersten Teil – Historische und epistemologische Grundlagen – geben wir einen kurzen Einblick in die geschichtliche Entwicklung der Analysis, stellen die Genese des Funktionsbegriffs als Leitidee des Mathematikunterrichts dar und zeigen die Rolle epistemologischer Hürden bei der Entwicklung des infinitesimalen Denkens auf. Im zweiten Teil – Funktionales Denken im Lernprozess – betrachten wir die kognitiven Aspekte funktionalen Denkens im Prozess der mathematischen Begriffsentwicklung. Im dritten Teil – Analysisunterricht – befassen wir uns mit den Kernbegriffen der Analysis und ihrer unterrichtlichen Vermittlung

More efficient aboveground nitrogen use in more diverse Central European forest canopies

We hypothesized that biodiversity improves ecosystem functioning and services such as nutrient cycling because of increased complementarity. We examined N canopy budgets of 27 Central European forests of varying dominant tree species, stand density, and tree and shrub species diversity (Shannon index) in three study regions by quantifying bulk and fine particulate dry deposition and dissolved below canopy N fluxes. Average regional canopy N retention ranged from 16% to 51%, because of differences in the N status of the ecosystems. Canopy N budgets of coniferous forests differed from deciduous forest which we attribute to differences in biogeochemical N cycling, tree functional traits and canopy surface area. The canopy budgets of N were related to the Shannon index which explained 14% of the variance of the canopy budgets of N, suggesting complementary aboveground N use of trees and diverse understorey vegetation. The relationship between plant diversity and canopy N retention varied among regional site conditions and forest types. Our results suggest that the traditional view of belowground complementarity of nutrient uptake by roots in diverse plant communities can be transferred to foliar uptake in forest canopies

Morphological Alterations in Gastrocnemius and Soleus Muscles in Male and Female Mice in a Fibromyalgia Model

<div><p>Background</p><p>Fibromyalgia (FM) is a chronic musculoskeletal pain disorder, characterized by chronic widespread pain and bodily tenderness and is often accompanied by affective disturbances, however often with unknown etiology. According to recent reports, physical and psychological stress trigger FM. To develop new treatments for FM, experimental animal models for FM are needed to be development and characterized. Using a mouse model for FM including intermittent cold stress (ICS), we hypothesized that ICS leads to morphological alterations in skeletal muscles in mice.</p><p>Methods</p><p>Male and female ICS mice were kept under alternating temperature (4°C/room temperature [22°C]); mice constantly kept at room temperature served as control. After scarification, gastrocnemius and soleus muscles were removed and snap-frozen in liquid nitrogen–cooled isopentane or fixed for electron microscopy.</p><p>Results</p><p>In gastrocnemius/soleus muscles of male ICS mice, we found a 21.6% and 33.2% decrease of fiber cross sectional area (FCSA), which in soleus muscle concerns the loss of type IIa and IIx FCSA. This phenomenon was not seen in muscles of female ICS mice. However, this loss in male ICS mice was associated with an increase in gastrocnemius of the density of MIF⁺ (8.6%)-, MuRF⁺ (14.7%)-, Fbxo32⁺ (17.8%)-cells, a 12.1% loss of capillary contacts/muscle fiber as well as a 30.7% increase of damaged mitochondria in comparison with male control mice. Moreover, significant positive correlations exist among densities (n/mm²) of MIF⁺, MuRF⁺, Fbxo32⁺-cells in gastrocnemius/ soleus muscles of male ICS mice; these cell densities inversely correlate with FCSA especially in gastrocnemius muscle of male ICS mice.</p><p>Conclusion</p><p>The ICS-induced decrease of FCSA mainly concerns gastrocnemius muscle of male mice due to an increase of inflammatory and atrogenic cells. In soleus muscle of male ICS and soleus/gastrocnemius muscles of female ICS mice morphological alterations seem to occur not at all or delayed. The sex-specificity of findings, which is not easily reconciled with the epidemiology of FM (female predominance), implicate that gastrocnemius muscle of male ICS mice should preferentially be used for future investigations with FM. Moreover, we suggest to investigate morphological and/or molecular alterations at different time-points (up to two weeks) after ICS.</p></div

Density (n/mm²) of MIF⁺ cells of gastrocnemius and soleus muscles.

<p>Representative images of cross sections of male (♂) gastrocnemius muscle immunostained for MIF (<b>A, C</b>) are shown. Furthermore quantification of MIF⁺ cells of gastrocnemius (E) and soleus (F) muscles are shown. Male control (<b>A, B</b>), male ICS (<b>C, D</b>); Hoechst 33342 was used as a nuclear counterstain (<b>B, D</b>). MIF⁺ immunoreaction is indicated by black arrows (A, C) Values are given as mean + SEM; ⁺⁺<i>P</i> <0.01 significance vs male ICS mice. N = 7–9 animals per group. Bar = 50 μm.</p

Fiber density (n/mm²) and fiber cross sectional area (μm²) of gastrocnemius (Gastro.) muscle.

<p>Representative images of gastrocnemius muscle cross sections stained for myofibrillar ATPase after pre-incubation at pH 4.6 of male (♂) control (<b>A</b>) and ICS (<b>B</b>) are shown. Quantification of fiber type density (<b>C</b>) and fiber cross sectional area (<b>D</b>) are shown. Type IIa (white cross); Values are given as mean + SEM; *<i>P</i> ≤ 0.05, significance vs control and ⁺<i>P</i> ≤ 0.05 vs male mice. N = 8–9 animals per group. Bar = 50 μm.</p

Density (n/mm²) of MuRF1⁺ and Fbxo32⁺ cells in mouse gastrocnemius and soleus muscles.

<p>Representative images of cross sections of male (♂) gastrocnemius muscle immunostained for MuRF1 (<b>A-D</b>) and Fbxo32 (<b>E-H</b>) are shown. Furthermore, quantification of MuRF1⁺ and Fbxo32⁺ cells in gastrocnemius (<b>I, K</b>) and soleus (<b>J, L</b>), muscles are shown. MuRF1⁺ male control (<b>A, B</b>) and male ICS (<b>C, D</b>); Fbxo32⁺ male control (<b>E, F</b>) and male ICS (<b>G, H</b>). Hoechst 33342 was used as a nuclear counterstain (<b>B, D, F, H</b>). MuRF1⁺ and Fbxo32⁺ cells are indicated by black arrows. Values are given as mean + SEM; **<i>P</i> < 0.01, significance vs control and ⁺<i>P</i> ≤ 0.05, ⁺⁺<i>P</i> < 0.01 and ⁺⁺⁺<i>P</i> <0.001 vs male mice. N = 7–9 animals per group. Bar = 50 μm.</p