Run-of-River hydropower and salmonids: potential effects and perspective on future research

2017 ◽  
Vol 74 (7) ◽  
pp. 1135-1149 ◽  
Author(s):  
P. Gibeau ◽  
B.M. Connors ◽  
W.J. Palen

The spatial footprint of individual run-of-river (RoR) hydropower facilities is smaller than reservoir-storage hydroelectric projects and their impacts to aquatic ecosystems are often assumed to be negligible. However, these effects are poorly understood, especially for salmonids whose freshwater habitat often overlaps with RoR hydropower potential. Flow regulation for RoR hydropower is unique in how it influences the seasonality and magnitude of flow diversion and because low-head dams can be overtopped at high flows. Based on a review of the primary literature, we identified three pathways of effects by which RoR hydropower may influence salmonids: reduction of flow, presence of low-head dams impounding rivers, and anthropogenic flow fluctuations. We synthesized empirical evidence of effects of RoR hydropower on river ecosystems from 31 papers, of which only 10 explicitly considered salmonids. We identified key research gaps including impacts of extended low-flow periods, anthropogenic flow fluctuations, and cumulative effects of multiple RoR projects. Filling these gaps is necessary to help manage and conserve salmonid populations in the face of the growing global demand for small-scale hydropower.

2021 ◽  
pp. 003232172110072
Author(s):  
Ramon van der Does ◽  
Vincent Jacquet

Deliberative minipublics are popular tools to address the current crisis in democracy. However, it remains ambiguous to what degree these small-scale forums matter for mass democracy. In this study, we ask the question to what extent minipublics have “spillover effects” on lay citizens—that is, long-term effects on participating citizens and effects on non-participating citizens. We answer this question by means of a systematic review of the empirical research on minipublics’ spillover effects published before 2019. We identify 60 eligible studies published between 1999 and 2018 and provide a synthesis of the empirical results. We show that the evidence for most spillover effects remains tentative because the relevant body of empirical evidence is still small. Based on the review, we discuss the implications for democratic theory and outline several trajectories for future research.


2015 ◽  
Vol 112 (43) ◽  
pp. 13207-13212 ◽  
Author(s):  
David J. Yu ◽  
Murad R. Qubbaj ◽  
Rachata Muneepeerakul ◽  
John M. Anderies ◽  
Rimjhim M. Aggarwal

The use of shared infrastructure to direct natural processes for the benefit of humans has been a central feature of human social organization for millennia. Today, more than ever, people interact with one another and the environment through shared human-made infrastructure (the Internet, transportation, the energy grid, etc.). However, there has been relatively little work on how the design characteristics of shared infrastructure affect the dynamics of social−ecological systems (SESs) and the capacity of groups to solve social dilemmas associated with its provision. Developing such understanding is especially important in the context of global change where design criteria must consider how specific aspects of infrastructure affect the capacity of SESs to maintain vital functions in the face of shocks. Using small-scale irrigated agriculture (the most ancient and ubiquitous example of public infrastructure systems) as a model system, we show that two design features related to scale and the structure of benefit flows can induce fundamental changes in qualitative behavior, i.e., regime shifts. By relating the required maintenance threshold (a design feature related to infrastructure scale) to the incentives facing users under different regimes, our work also provides some general guidance on determinants of robustness of SESs under globalization-related stresses.


2011 ◽  
Vol 34 (2) ◽  
pp. 241-282 ◽  
Author(s):  
Elyse Amend ◽  
David M. Secko

The qualitative literature related to health and science journalism often states that little is known about the perspectives of journalists. This is, in part, because of individual studies being like scattered pieces of a jigsaw puzzle. In this article, the authors report the results of a qualitative metasynthesis aimed at reassembling the qualitative literature involving health and science journalists. Comprehensive literature searches gave a data set of 21 studies whose synthesis produced 14 metathemes and four taxonomic groupings. This synthesis is used to show the state of qualitative knowledge and the potential for future research.


2018 ◽  
Vol 314 (5) ◽  
pp. F921-F925 ◽  
Author(s):  
Di Feng ◽  
Clark DuMontier ◽  
Martin R. Pollak

Focal segmental glomerulosclerosis (FSGS) is a histologically defined form of kidney injury typically mediated by podocyte dysfunction. Podocytes rely on their intricate actin-based cytoskeleton to maintain the glomerular filtration barrier in the face of mechanical challenges resulting from pulsatile blood flow and filtration of this blood flow. This review summarizes the mechanical challenges faced by podocytes in the form of stretch and shear stress, both of which may play a role in the progression of podocyte dysfunction and detachment. It also reviews how podocytes respond to these mechanical challenges in dynamic fashion through rearranging their cytoskeleton, triggering various biochemical pathways, and, in some disease states, altering their morphology in the form of foot process effacement. Furthermore, this review highlights the growing body of evidence identifying several mutations of important cytoskeleton proteins as causes of FSGS. Lastly, it synthesizes the above evidence to show that a better understanding of how these mutations leave podocytes vulnerable to the mechanical challenges they face is essential to better understanding the mechanisms by which they lead to disease. The review concludes with future research directions to fill this gap and some novel techniques with which to pursue these directions.


2021 ◽  
Vol 07 ◽  
Author(s):  
Wei Li

: Exploring low-cost, green and safe technologies to provide an alternative to the conventional selective catalytic reduction process is key to the control of NOx emitted from small-scale boilers and other industrial processes. To meet the demand, the chemical absorption-biological reduction integrated system has been developing recently. chemical absorption-biological reduction integrated system applies Fe(II)EDTA for NO absorption and iron-reducing and denitrifying bacteria for absorbent regeneration. Many studies have focused on the enhancements of mass transfer and biological reaction, among which the biological processes were the rate-limiting steps. This review summarizes the current researches on the biological processes in the CABR system, which focuses on the mechanism and enhancement of biochemical reactions, and provides the possible directions of future research.


Author(s):  
Xiaoli Tian ◽  
Qian Li

With more social interactions shifting to online venues, the different attributes of major social media sites in China influence how interpersonal interactions are carried out. Despite the lack of physical co-presence online, face culture is extended to online spaces. On social media, Chinese users tend to protect their own face, give face to others, and avoid discrediting the face of others, especially when their online and offline networks overlap. This chapter also discusses the different methods used to study facework online and offline and how facework is studied in different parts of the world. It concludes with a brief discussion of how sociological research has contributed to the study of social media in China and directions for future research.


2010 ◽  
Vol 365 (1542) ◽  
pp. 901-914 ◽  
Author(s):  
Kristy L. Gould ◽  
Debbie M. Kelly ◽  
Alan C. Kamil

Many animals use cues for small-scale navigation, including beacons, landmarks, compasses and geometric properties. Scatter-hoarding animals are a unique system to study small-scale navigation. They have to remember and relocate many individual spatial locations, be fairly accurate in their searching and have to remember these locations for long stretches of time. In this article, we review what is known about cue use in both scatter-hoarding birds and rodents. We discuss the importance of local versus global cues, the encoding of bearings and geometric rules, the use of external compasses such as the Sun and the influence of the shape of experimental enclosures in relocating caches or hidden food. Scatter-hoarding animals are highly flexible in how and what they encode. There also appear to be differences in what scatter-hoarding birds and rodents encode, as well as what scatter-hoarding animals in general encode compared with other animals. Areas for future research with scatter-hoarding animals are discussed in light of what is currently known.


2017 ◽  
Vol 7 (4) ◽  
pp. 24
Author(s):  
Vida Dehnad

Adaptation to change is not an easy process and sometimes does not happen at all. When people perceive that theirfreedom is going to be altered due to an unwanted change, they outwardly exhibit some symptomatic reactivebehaviors such as inertia, resistance, skepticism, and aggression. No matter how intense people’s reactance is, only afew of them may manage to examine the unwanted change more deeply and find a way to conform or adapt. Knowingthis, the current article focuses on a theoretical proactive model or a solution. The model mainly works on the idea ofrecognizing the symptomatic behavioral reactance of learners. In other words, in the face of the reactance-inducedbehaviors depicted in the model, the instructors can apply four proactive strategies of brainstorming, open transparentconversation, small scale project assignment and triple “c” rule by means of which they can walk learners safelytowards mutual trust, classroom stability and learner commitment. In the end, as the model is new, there is still enoughroom for further experimental researches on different aspects of the model in actual classroom settings.


2015 ◽  
Vol 23 (3) ◽  
pp. 257-262 ◽  
Author(s):  
John Gichimu Mbaka ◽  
Mercy Wanjiru Mwaniki

The downstream ecological effects of large impoundments have previously been reviewed; however, little is known about the downstream ecological effects of small man-made impoundments. In this review, we examine 94 papers focusing on the effects of small impoundments on stream habitat conditions and macroinvertebrates. Most studies (89.3%) address the effects of small impoundments on physical and chemical habitat conditions, while fewer studies (48.9%) address the effects on macroinvertebrates. In general, most studies report no significant downstream effects of small impoundments on physico-chemical variables, whereas macroinvertebrates richness and abundance increased or decreased. Mean effect sizes (as Cohen’s d) for physico-chemical variables range from −0.82 to 0.68 (small weir: −0.21 to 0.35; run-of-river dam: −0.82 to 0.64; low head dam: −0.49 to 0.68), and from −0.03 to 0.63 for macroinvertebrates abundance and richness. Our assessment of the published literature demonstrates the advantage of combining qualitative and quantitative analyses, and that, while small impoundments may have minimal significant effects on most physico-chemical variables, macroinvertebrates’ richness and density may be affected. This review is relevant for management and scientific communities to identify potential alterations of stream habitats and biota by small impoundments.


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