TY - JOUR A1 - Beisner, Beatrix E. A1 - Grossart, Hans-Peter A1 - Gasol, Josep M. T1 - A guide to methods for estimating phago-mixotrophy in nanophytoplankton JF - Journal of plankton research N2 - Growing attention to phytoplankton mixotrophy as a trophic strategy has led to significant revisions of traditional pelagic food web models and ecosystem functioning. Although some empirical estimates of mixotrophy do exist, a much broader set of in situ measurements are required to (i) identify which organisms are acting as mixotrophs in real time and to (ii) assess the contribution of their heterotrophy to biogeochemical cycling. Estimates are needed through time and across space to evaluate which environmental conditions or habitats favour mixotrophy: conditions still largely unknown. We review methodologies currently available to plankton ecologists to undertake estimates of plankton mixotrophy, in particular nanophytoplankton phago-mixotrophy. Methods are based largely on fluorescent or isotopic tracers, but also take advantage of genomics to identify phylotypes and function. We also suggest novel methods on the cusp of use for phago-mixotrophy assessment, including single-cell measurements improving our capacity to estimate mixotrophic activity and rates in wild plankton communities down to the single-cell level. Future methods will benefit from advances in nanotechnology, micromanipulation and microscopy combined with stable isotope and genomic methodologies. Improved estimates of mixotrophy will enable more reliable models to predict changes in food web structure and biogeochemical flows in a rapidly changing world. KW - flow cytometry KW - phagotrophy KW - phytoplankton KW - methods KW - fluorescence KW - microscopy KW - FISH KW - isotopic methods KW - phylotypes KW - carbon flows KW - gene sequencing Y1 - 2019 U6 - https://doi.org/10.1093/plankt/fbz008 SN - 0142-7873 SN - 1464-3774 VL - 41 IS - 2 SP - 77 EP - 89 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Ekkekakis, Panteleimon A1 - Brand, Ralf T1 - Affective responses to and automatic affective valuations of physical activity BT - Fifty years of progress on the seminal question in exercise psychology JF - Psychology of sport and exercise N2 - Objective: To critically review developments over the first fifty years of research (1967-2017) on (a) how people feel when they participate in exercise and physical activity, and (b) the implications of these responses for their willingness to become and remain active. Design: Non-systematic narrative review. Method: Representative sources were selected through a combination of computer searches and cross-referencing. Results: For over three decades, exercise psychology exhibited a fixation on the idea that exercise and physical activity make people feel better. This notion, however, seemed to contrast with evidence that most adults in industrialized countries exhibit low levels of activity. In the last two decades, a critical examination and overhaul of the methodological platform resulted in the delineation of a dose-response pattern that encompasses positive as well as negative affective responses, and revealed marked interindividual differences. An emerging literature is aimed at refining and testing integrative dual-process models that can offer specific predictions about the behaviors that may result from the interaction of automatic processes (theorized to be heavily influenced by past affective experiences) and deliberative processes (such as cognitive appraisals). Conclusions: Affective responses to exercise and physical activity are more complex than the long-popularized "feel-better" effect, encompassing both pleasant and unpleasant experiences and exhibiting marked inter individual variation. The potential of affective experiences to influence subsequent behavior offers an opportunity for an expanded theoretical perspective in exercise psychology. KW - Pleasure KW - Displeasure KW - Ventilatory threshold KW - Automatic affective valuation Y1 - 2019 U6 - https://doi.org/10.1016/j.psychsport.2018.12.018 SN - 1469-0292 SN - 1878-5476 VL - 42 SP - 130 EP - 137 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Langhammer, Maria A1 - Thober, Jule A1 - Lange, Martin A1 - Frank, Karin A1 - Grimm, Volker T1 - Agricultural landscape generators for simulation models BT - a review of existing solutions and an outline of future directions JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - There is an increasing need for an assessment of the impacts of land use and land use change (LUCC). In this context, simulation models are valuable tools for investigating the impacts of stakeholder actions or policy decisions. Agricultural landscape generators (ALGs), which systematically and automatically generate realistic but simplified representations of land cover in agricultural landscapes, can provide the input for LUCC models. We reviewed existing ALGs in terms of their objectives, design and scope. We found eight ALGs that met our definition. They were based either on generic mathematical algorithms (pattern-based) or on representations of ecological or land use processes (process-based). Most ALGs integrate only a few landscape metrics, which limits the design of the landscape pattern and thus the range of applications. For example, only a few specific farming systems have been implemented. We conclude that existing ALGs contain useful approaches that can be used for specific purposes, but ideally generic modular ALGs are developed that can be used for a wide range of scenarios, regions and model types. We have compiled features of such generic ALGs and propose a possible software architecture. Considerable joint efforts are required to develop such generic ALGs, but the benefits in terms of a better understanding and development of more efficient agricultural policies would be high. KW - Agricultural landscape KW - Field pattern KW - Agricultural landscape generator KW - Landscape simulator KW - Neutral landscape model KW - Process-based model Y1 - 2019 U6 - https://doi.org/10.1016/j.ecolmodel.2018.12.010 SN - 0304-3800 SN - 1872-7026 VL - 393 SP - 135 EP - 151 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jeglinski-Mende, Melinda A. T1 - Alcohol in the aging brain BT - the interplay between alcohol consumption, cognitive decline and the cardiovascular system JF - Frontiers in neuroscience N2 - As our society grows older new challenges for medicine and healthcare emerge. Age-related changes of the body have been observed in essential body functions, particularly in the loco-motor system, in the cardiovascular system and in cognitive functions concerning both brain plasticity and changes in behavior. Nutrition and lifestyle, such as nicotine intake and chronic alcohol consumption, also contribute to biological changes in the brain. This review addresses the effect of alcohol consumption on cognitive decline, changes in brain plasticity in the aging brain and on cardiovascular health in aging. Thus, studies on the interplay of chronic alcohol intake and either cognitive decline or cognitive preservation are outlined. Because of the inconsistency in the literature of whether alcohol consumption preserves cognitive functions in the aging brain or whether it accelerates cognitive decline, it is crucial to consider individual contributing factors such as culture, health and lifestyle in future studies. KW - cognitive decline KW - neuroplasticity KW - AUD KW - alcohol consumption KW - aging brain Y1 - 2019 U6 - https://doi.org/10.3389/fnins.2019.00713 SN - 1662-453X VL - 13 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Schulze-Gabrechten, Lena T1 - An organizational approach to public governance BT - understanding and design JF - Public administration N2 - In this volume, Egeberg and Trondal put forward an ‘organizational approach to public governance’ (p. 1) that, in their view, complements existing explanations for organizational change and behaviour in governance processes (‘Understanding’) and produces relevant advice for practitioners, specifically anyone involved in reorganizing public administration (‘Design’). Following the authors’ introduction of the theoretical reasoning behind their approach (chapter 1), they present supporting findings that are based on new material (chapters 2 and 9), but mainly draw on six previously published research articles (chapters 3–8). Egeberg and Trondal conclude with possible ‘design implications’ of said findings (chapter 9). Their ‘organizational approach’ focuses on the impact of selected organizational characteristics on decision‐making in and on behalf of government organizations in policy‐making generally (‘public governance’) and administrative politics more specifically (‘meta‐governance’). The authors concentrate on three sets of ‘classical’ organizational characteristics: structure (mainly vertical and horizontal specialization), demography (personnel composition), and locus (geographical location). The conceptual part of the volume convincingly summarizes ‘formal organization matters’—arguments from the literature for each of the individual organizational factors. Their main, already well‐established argument is that the way an organization is formally set up makes some (reform) decisions more likely than others—a line of reasoning that the authors present as neglected in governance literature. In the following five empirical chapters, the authors show that aspects of horizontal and vertical specialization—mainly operationalized by Gulicks’ principles of horizontal specialization and the idea of primary versus secondary affiliation of staff—affect organizational behaviour. Readers learn that whether government levels are organized according to a territorial or non‐territorial principle impacts the power relationship between levels: non‐territorial organization at the supranational level tends to empower the centre against lower levels of government. There are two chapters on the decision‐making behaviour of commissioners and officials in the European Commission, both showing that organizational affiliation trumps demographic background factors such as nationality, even with temporary staff. Chapter 5 addresses coordination dynamics in the European multi‐level system and finds that coordination at the territorially organized national level thwarts non‐territorially organized coordination at the supranational level, resulting in the phenomenon of ‘direct’ national administration bypassing their national executives. Further, the authors show that vertical specialization—while controlling for other factors such as issue salience—has an effect on officials’ behaviour at the national level: agency officials in Norway report significantly less sensitivity towards political signals from the political executive than their colleagues in ministries. Chapter 7 discusses the relevance of geographical location for the relationship between subordinated organizations and their political executive. The authors find that the site of Norwegian agencies does not significantly affect their autonomy, influence, or inter‐institutional coordination with the superior ministry. The last empirical chapter focuses on the effect of formal organization on meta‐governance, that is, administrative politics. Based on a qualitative case study of a reorganization process in Norway in 2003 involving the synchronized relocation of several agencies after many failed attempts, the authors conclude that administrative reforms can be politically steered and controlled through the organization of the reform process. They argue that amongst other factors the strategic exclusion of opposing actors from the reform process as well as the deliberate increase in situations demanding quick decisions (‘action rationality’, p. 119) by political leaders helps explain the reform's unexpected success. The last chapter is dedicated to the synthesis of the results and to design implications. Supported by new data from a 2016 survey among Norwegian public officials, the authors conclude that organizational position is the most important influencer of decision‐making behaviour, with educational background and previous job experience also playing a large role (p. 135). Consequently, their suggestions for practitioners involved in meta‐governance processes concentrate on aspects of the deliberate crafting of organizational specialization to shape organizational positions, and spend less time discussing location and employee demographics. The authors illustrate and contextualize their recommendations with the help of three empirical examples: organizing good governance by balancing political control and independence in the case of agencification, organizing for coping with boundary‐spanning challenges such as climate change through inter‐organizational structural arrangements, and designing permanent organizational structures for innovative reforms in the public sector (pp. 137 ff.). This volume is an excellent compilation of theoretically informed applications of the all too often undefined ‘organization matters’ argument. It juxtaposes—particularly in the theory chapter and in the last chapter on design implications—organizational arguments against other explanations of organizational change like historical institutionalism or the garbage can model of decision‐making. However, two major aspects of the book's approach are less convincing. First, supplementary explanations such as the garbage can model that are discussed in the reflections on meta‐governance are neither argumentatively nor empirically applied to public governance; why should, for example, the ‘solutions in search of a problem’ idea only be applicable to decisions on reform policy, but not to decisions in all other policy areas? Similarly, it would have been nice to read more on the authors’ idea on the interaction between organizational factors and between them and other explanations in the empirical cases on public governance—this would have allowed the reader to get a better idea about how much formal organization matters. The view on bureaucrats’ demographic background is slightly confusing: it is presented as a competing approach (p. 7), but also as one of the main organizational factors (p. 12). Second, as the authors themselves state, the concept of governance is about ‘steering through collective action’ (p. 3) and focuses on interactive processes, and explicitly includes non‐governmental actors in the policy‐making equation. Against this background it seems unfortunate that most of the work presented in the book takes an exclusively governmental perspective and the justification for it remains rather superficial. It would be preferable and even necessary to see the organizational arguments—at least theoretically or through discussing appropriate literature—applied to interactive governance processes involving other actors and/or to non‐bureaucratic organizations. Regarding its methodology, the specifics of the proposed approach deserve to be addressed more systematically and critically in the book. Except for chapters 2, 3 and 5 (literature‐based studies) as well as chapter 8 (single case study), the empirical studies follow a quantitative logic and are informed by data on self‐reported behaviour through large‐N panel surveys with public officials. In terms of analysis, descriptive statistics or basic inferential statistics (linear regression) are employed. Certainly, the authors are aware of the limitations of their data sources, such as the results being possibly affected by social desirability, and they discuss and justify them in the chapters individually (e.g., on pp. 47, 89). Still, their approach could be strengthened with a more cautious account on the extent to which their choice of data and methods is able to uncover the ‘causal impact of organizational factors in public governance processes’ (p. 131, emphasis added) and with some suggestions for widening their methodological toolbox in the future. On this note, the survey method presented as new on p. 135 is not a particularly convincing choice. The authors do not lay out a research agenda; a surprising omission. This is, however, somewhat made up for by the concluding chapter's stimulating discussion of the possible real‐world implications of their findings and perspective, skilfully using organization theory as a ‘craft’ (p. 29). Y1 - 2019 U6 - https://doi.org/10.1111/padm.12590 SN - 0033-3298 SN - 1467-9299 VL - 97 IS - 2 SP - 483 EP - 485 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Hargis, Hailey A1 - Gotsch, Sybil G. A1 - Porada, Philipp A1 - Moore, Georgianne W. A1 - Ferguson, Briana A1 - Van Stan, John T. T1 - Arboreal epiphytes in the soil-atmosphere interface BT - how often are the biggest "buckets" in the canopy empty? JF - Geosciences N2 - Arboreal epiphytes (plants residing in forest canopies) are present across all major climate zones and play important roles in forest biogeochemistry. The substantial water storage capacity per unit area of the epiphyte "bucket" is a key attribute underlying their capability to influence forest hydrological processes and their related mass and energy flows. It is commonly assumed that the epiphyte bucket remains saturated, or near-saturated, most of the time; thus, epiphytes (particularly vascular epiphytes) can store little precipitation, limiting their impact on the forest canopy water budget. We present evidence that contradicts this common assumption from (i) an examination of past research; (ii) new datasets on vascular epiphyte and epi-soil water relations at a tropical montane cloud forest (Monteverde, Costa Rica); and (iii) a global evaluation of non-vascular epiphyte saturation state using a process-based vegetation model, LiBry. All analyses found that the external and internal water storage capacity of epiphyte communities is highly dynamic and frequently available to intercept precipitation. Globally, non-vascular epiphytes spend <20% of their time near saturation and regionally, including the humid tropics, model results found that non-vascular epiphytes spend similar to 1/3 of their time in the dry state (0-10% of water storage capacity). Even data from Costa Rican cloud forest sites found the epiphyte community was saturated only 1/3 of the time and that internal leaf water storage was temporally dynamic enough to aid in precipitation interception. Analysis of the epi-soils associated with epiphytes further revealed the extent to which the epiphyte bucket emptied-as even the canopy soils were often <50% saturated (29-53% of all days observed). Results clearly show that the epiphyte bucket is more dynamic than currently assumed, meriting further research on epiphyte roles in precipitation interception, redistribution to the surface and chemical composition of "net" precipitation waters reaching the surface. KW - precipitation KW - interception KW - bromeliad KW - vascular epiphyte KW - non-vascular epiphyte KW - lichens KW - bryophytes KW - water storage capacity Y1 - 2019 U6 - https://doi.org/10.3390/geosciences9080342 SN - 2076-3263 VL - 9 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - König, Jeannette A1 - Grune, Tilman A1 - Ott, Christiane T1 - Assessing autophagy in murine skeletal muscle: current findings to modulate and quantify the autophagic flux JF - Current opinion in clinical nutrition and metabolic care N2 - Purpose of review In addition to the currently available lysosomotropic drugs and autophagy whole-body knockout mouse models, we provide alternative methods that enable the modulation and detection of autophagic flux in vivo, discussing advantages and disadvantages of each method. Recent findings With the autophagosome-lysosome fusion inhibitor colchicine in skeletal muscle and temporal downregulation of autophagy using a novel Autophagy related 5-short hairpin RNA (Atg5-shRNA) mouse model we mention two models that directly modulate autophagy flux in vivo. Furthermore, methods to quantify autophagy flux, such as mitophagy transgenic reporters, in situ immunofluorescent staining and multispectral imaging flow cytometry, in mature skeletal muscle and cells are addressed. To achieve clinical benefit, less toxic, temporary and cell-type-specific modulation of autophagy should be pursued further. A temporary knockdown as described for the Atg5-shRNA mice could provide a first insight into possible implications of autophagy inhibition. However, it is also important to take a closer look into the methods to evaluate autophagy after harvesting the tissue. In particular caution is required when experimental conditions can influence the final measurement and this should be pretested carefully. KW - autophagy flux KW - in vivo KW - skeletal muscle Y1 - 2019 U6 - https://doi.org/10.1097/MCO.0000000000000579 SN - 1363-1950 SN - 1473-6519 VL - 22 IS - 5 SP - 355 EP - 362 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Dai, Xiaolin A1 - Böker, Alexander A1 - Glebe, Ulrich T1 - Broadening the scope of sortagging JF - RSC Advances N2 - Sortases are enzymes occurring in the cell wall of Gram-positive bacteria. Sortase A (SrtA), the best studied sortase class, plays a key role in anchoring surface proteins with the recognition sequence LPXTG covalently to oligoglycine units of the bacterial cell wall. This unique transpeptidase activity renders SrtA attractive for various purposes and motivated researchers to study multiple in vivo and in vitro ligations in the last decades. This ligation technique is known as sortase-mediated ligation (SML) or sortagging and developed to a frequently used method in basic research. The advantages are manifold: extremely high substrate specificity, simple access to substrates and enzyme, robust nature and easy handling of sortase A. In addition to the ligation of two proteins or peptides, early studies already included at least one artificial (peptide equipped) substrate into sortagging reactions - which demonstrates the versatility and broad applicability of SML. Thus, SML is not only a biology-related technique, but has found prominence as a major interdisciplinary research tool. In this review, we provide an overview about the use of sortase A in interdisciplinary research, mainly for protein modification, synthesis of protein-polymer conjugates and immobilization of proteins on surfaces. Y1 - 2019 U6 - https://doi.org/10.1039/c8ra06705h SN - 2046-2069 VL - 9 IS - 9 SP - 4700 EP - 4721 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Tarasova, Larisa A1 - Merz, Ralf A1 - Kiss, Andrea A1 - Basso, Stefano A1 - Blöchl, Günter A1 - Merz, Bruno A1 - Viglione, Alberto A1 - Plötner, Stefan A1 - Guse, Björn A1 - Schumann, Andreas A1 - Fischer, Svenja A1 - Ahrens, Bodo A1 - Anwar, Faizan A1 - Bárdossy, András A1 - Bühler, Philipp A1 - Haberlandt, Uwe A1 - Kreibich, Heidi A1 - Krug, Amelie A1 - Lun, David A1 - Müller-Thomy, Hannes A1 - Pidoto, Ross A1 - Primo, Cristina A1 - Seidel, Jochen A1 - Vorogushyn, Sergiy A1 - Wietzke, Luzie T1 - Causative classification of river flood events JF - Wiley Interdisciplinary Reviews : Water N2 - A wide variety of processes controls the time of occurrence, duration, extent, and severity of river floods. Classifying flood events by their causative processes may assist in enhancing the accuracy of local and regional flood frequency estimates and support the detection and interpretation of any changes in flood occurrence and magnitudes. This paper provides a critical review of existing causative classifications of instrumental and preinstrumental series of flood events, discusses their validity and applications, and identifies opportunities for moving toward more comprehensive approaches. So far no unified definition of causative mechanisms of flood events exists. Existing frameworks for classification of instrumental and preinstrumental series of flood events adopt different perspectives: hydroclimatic (large-scale circulation patterns and atmospheric state at the time of the event), hydrological (catchment scale precipitation patterns and antecedent catchment state), and hydrograph-based (indirectly considering generating mechanisms through their effects on hydrograph characteristics). All of these approaches intend to capture the flood generating mechanisms and are useful for characterizing the flood processes at various spatial and temporal scales. However, uncertainty analyses with respect to indicators, classification methods, and data to assess the robustness of the classification are rarely performed which limits the transferability across different geographic regions. It is argued that more rigorous testing is needed. There are opportunities for extending classification methods to include indicators of space-time dynamics of rainfall, antecedent wetness, and routing effects, which will make the classification schemes even more useful for understanding and estimating floods. This article is categorized under: Science of Water > Water Extremes Science of Water > Hydrological Processes Science of Water > Methods KW - flood genesis KW - flood mechanisms KW - flood typology KW - historical floods KW - hydroclimatology of floods Y1 - 2019 U6 - https://doi.org/10.1002/wat2.1353 SN - 2049-1948 VL - 6 IS - 4 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Spahn, Frank A1 - Sachse, Manuel A1 - Seiss, Martin A1 - Hsu, Hsiang-Wen A1 - Kempf, Sascha A1 - Horanyi, Mihaly T1 - Circumplanetary Dust Populations JF - Space science reviews N2 - We summarize the current state of observations of circumplanetary dust populations, including both dilute and dense rings and tori around the giant planets, ejecta clouds engulfing airless moons, and rings around smaller planetary bodies throughout the Solar System. We also discuss the theoretical models that enable these observations to be understood in terms of the sources, sinks and transport of various dust populations. The dynamics and resulting transport of the particles can be quite complex, due to the fact that their motion is influenced by neutral and plasma drag, radiation pressure, and electromagnetic forcesall in addition to gravity. The relative importance of these forces depends on the environment, as well as the makeup and size of the particles. Possible dust sources include the generation of ejecta particles by impacts, active volcanoes and geysers, and the capture of exogenous particles. Possible dust sinks include collisions with moons, rings, or the central planet, erosion due to sublimation and sputtering, even ejection and escape from the circumplanetary environment. KW - Circumplanetary dust KW - Planetary rings and tori KW - Dust sources and sinks KW - Dust dynamics Y1 - 2019 U6 - https://doi.org/10.1007/s11214-018-0577-3 SN - 0038-6308 SN - 1572-9672 VL - 215 IS - 1 PB - Springer CY - Dordrecht ER -