Temporal dynamics of large woody debris in small streams of the Alberta foothills, Canada

2009 ◽  
Vol 39 (6) ◽  
pp. 1159-1170 ◽  
Author(s):  
S.R. Powell ◽  
L.D. Daniels ◽  
T.A. Jones

Large woody debris (LWD) is a key link between riparian forests and streams; however, the temporal dynamics of in-stream wood remains poorly quantified. Using dendrochronology, we evaluated the dynamics of five Pinus -dominated and five Picea -dominated riparian forests in the foothills of Alberta and cross-dated the ring widths of 186 pieces of LWD. Time since death of LWD ranged from 2 to 143 years, with maximums of 86 and 143 years for Pinus and Picea, respectively. Recruitment of Pinus LWD was influenced by stand-replacing fires followed by self-thinning about 40 years after stand establishment. In uneven-aged Picea-dominated forests, tree mortality and LWD recruitment were due to fine-scale disturbances. Time since death increased significantly with decay and position classes, which resulted in changes in LWD function through time. LWD persisted in the bridge position for about 30 years. Bridged LWD was least decayed, was significantly longer, and had greater volume than LWD in other positions. LWD remained in partial bridge and loose positions about 15 years and >80 years when submerged in water and buried in sediment. Given the persistence of LWD, we conclude that management that alters wood abundance and recruitment has short- and long-term implications for the structure and function of small streams.

Author(s):  
Bryan Romito ◽  
Joseph Meltzer

The primary goal of this chapter is to provide the reader with an overview of basic renal physiology and function and to review the identification, pathogenesis, and treatment of acute kidney injury following cardiac surgery. Particular focus will be directed toward the diagnostic criteria for acute kidney injury, short- and long-term impacts on patient outcomes, role of novel biomarkers, mechanisms of acute renal injury, general management principles, preventative strategies, and the influence of anesthetic and surgical techniques on its development. The content of this chapter will serve to underscore a particularly harmful but likely underappreciated problem affecting patients in the cardiothoracic critical care setting.


2010 ◽  
Vol 1 (2) ◽  
pp. 146-151 ◽  
Author(s):  
John A. Sweka ◽  
Kyle J. Hartman ◽  
Jonathan M. Niles

Abstract In this study, we resurveyed stream habitat and sampled brook trout Salvelinus fontinalis populations 6 y after large woody debris additions to determine long-term changes in habitat and brook trout populations. In a previous study, we added large woody debris to eight streams in the central Appalachians of West Virginia to determine whether stream habitat could be enhanced and brook trout populations increased following habitat manipulation. The large woody debris additions had no overall effect on stream habitat and brook trout populations by 6 y after the additions. The assumption that a lack of large woody debris is limiting stream habitat and brook trout populations was not supported by our results. In high-gradient streams, habitat complexity may be governed more by the abundance of boulders and large woody debris may have a lesser influence on trout populations.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 92 ◽  
Author(s):  
Jan Dörrie ◽  
Niels Schaft ◽  
Gerold Schuler ◽  
Beatrice Schuler-Thurner

Over the last two decades, dendritic cell (DC) vaccination has been studied extensively as active immunotherapy in cancer treatment and has been proven safe in all clinical trials both with respect to short and long-term side effects. For antigen-loading of dendritic cells (DCs) one method is to introduce mRNA coding for the desired antigens. To target the whole antigenic repertoire of a tumor, even the total tumor mRNA of a macrodissected biopsy sample can be used. To date, reports have been published on a total of 781 patients suffering from different tumor entities and HIV-infection, who have been treated with DCs loaded with mRNA. The majority of those were melanoma patients, followed by HIV-infected patients, but leukemias, brain tumors, prostate cancer, renal cell carcinomas, pancreatic cancers and several others have also been treated. Next to antigen-loading, mRNA-electroporation allows a purposeful manipulation of the DCs’ phenotype and function to enhance their immunogenicity. In this review, we intend to give a comprehensive summary of what has been published regarding clinical testing of ex vivo generated mRNA-transfected DCs, with respect to safety and risk/benefit evaluations, choice of tumor antigens and RNA-source, and the design of better DCs for vaccination by transfection of mRNA-encoded functional proteins.


2020 ◽  
Vol 55 (10) ◽  
pp. 927-943 ◽  
Author(s):  
Giovanni Marasco ◽  
Matteo Serenari ◽  
Matteo Renzulli ◽  
Luigina Vanessa Alemanni ◽  
Benedetta Rossini ◽  
...  

Abstract Changes in body composition are associated with poor outcomes in cancer patients including hepatocellular carcinoma (HCC). Sarcopenia, defined as the loss of skeletal muscle mass, quality and function, has been associated with a higher rate of complications and recurrences in patients with cirrhosis and HCC. The assessment of patient general status before HCC treatment, including the presence of sarcopenia, is a key-point for achieving therapy tolerability and to avoid short- and long-term complications leading to poor patients’ survival. Thus, we aimed to review the current literature evaluating the role of sarcopenia assessment related to HCC treatments and to critically provide the clinicians with the most recent and valuable evidence. As a result, sarcopenia can be predictive of poor outcomes in patients undergoing liver resection, transplantation and systemic therapies, offering the chance to clinicians to improve the muscular status of these patients, especially those with high-grade sarcopenia at high risk of mortality. Further studies are needed to clarify the predictive value of sarcopenia in other HCC treatment settings and to evaluate its role as an additional staging tool for identifying the most appropriate treatment. Besides, interventional studies aiming at increasing the skeletal muscle mass for reducing complications and increasing the survival in patients with HCC are needed.


2005 ◽  
Vol 35 (5) ◽  
pp. 1213-1223 ◽  
Author(s):  
David P Kreutzweiser ◽  
Kevin P Good ◽  
Trent M Sutton

The inputs, characteristics, and function of large woody debris (LWD) were assessed in 16 mid-order (average channel widths of 3–7 m), moderate-gradient (approx. 1%–5% channel slopes) streams in mixedwood forests of the Boreal Shield in Ontario. Three of the streams were adjacent to clearcuts, with the remainder in areas that have not been logged or recently (>70 years) burned. The average frequency (19.9 pieces·100 m–1) and size (mean diameter 16.7 cm) of LWD in these streams were less than reported in most other regions and forest types. Averaged across sites, input sources were undetermined for about 50% of the LWD owing to fluvial displacement from the points of origin. Natural mortality (24%) and windthrow (15%) were primary input sources of the remaining LWD. Windthrow was highly variable and mostly associated with nearby clear-cut logging. At the three sites near clearcuts, windthrow contributed 34%–62% of LWD in streams. In study reaches where active beaver colonies were observed, beaver-felled trees accounted for up to 47% of LWD inputs. The average frequency of debris dams (2.4 dams·100 m–1) was less than those reported from studies in other areas and was positively correlated with an index of bottom substrate size (r = 0.72). Less than 15% of the pools in these streams were formed or influenced by LWD. Most wood pieces appeared to be ineffective as pool-forming agents because of their relatively small size and instability. In these Boreal Shield forests, it appears that most riparian trees do not live long enough or grow to sufficient size to contribute functional LWD and influence stream morphology or pool formation.


1995 ◽  
Vol 52 (8) ◽  
pp. 1789-1802 ◽  
Author(s):  
Ann D. Richmond ◽  
Kurt D. Fauseh

Large woody debris has been well studied in coastal forests of the Pacific Northwest, but little is known of its role in Rocky Mountain streams. Large woody debris was measured in 11 undisturbed streams draining subalpine old-growth forests in north central Colorado to assess abundance, characteristics, and function. Although large woody debris in Colorado had smaller diameter, length, and volume than in the Pacific Northwest, its abundance and function were similar. The majority of pools (76%) were plunge and dammed pools formed by large woody debris, most of which spanned the channels perpendicular to stream flow. Smaller streams had a greater proportion of such perpendicular pool-forming pieces than larger streams. Four disturbed streams had significantly less and smaller large woody debris than undisturbed streams. Flows in larger undisturbed streams were capable of moving large woody debris, so pieces were more often located at the stream margins, oriented diagonally, or distributed in clumps than in smaller streams. Individual pools were larger and deeper in larger streams, but their size was not related to the size of large woody debris pieces forming them. Therefore, the function of large woody debris in forming fish habitat in small Rocky Mountain streams is strongly influenced by the stream's location within the watershed.


2019 ◽  
Vol 78 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Emilie Combet ◽  
Stuart R. Gray

The Nutrition Society Spring Conference 2018, held in Glasgow, brought together experts focusing on the interaction between different nutrients and how this impacts absorption, metabolism and health from biochemical and physiological perspectives. This cross-cutting theme was examined from a range of perspectives, bringing together experts on topics ranging from food processing to the impact of inflammation on nutrient status. Two plenary lectures provided a food landscape and lifecourse background to the proceedings, with on the first day a focus on processed/ultra-processed foods and their nutrient composition and, on the second day, a plenary lecture exploring the role that nutrient–nutrient interactions within the maternal diet have for the lifelong health of the offspring. The meeting was framed around three symposia, examining the competition and bioavailability of dietary components, nutrient–nutrient interactions and their role in protection from chronic diseases and the mechanisms of nutrient–nutrient interactions. The meeting ended with a round table, and an overall conclusion highlighting the opportunities to derive further understanding of the short- and long-term implications of diets through the study of nutrient–nutrient interactions.


2021 ◽  
pp. 204138662110064
Author(s):  
Belinda S. Cham ◽  
Alexandra A. Boeing ◽  
Michael David Wilson ◽  
Mark A. Griffin ◽  
Karina Jorritsma

Extreme work environments are inherently stressful and involve challenging working and living conditions. In contexts ranging from space exploration to disaster response, people must sustain performance under pressure, and function with limited resources. In this paper we develop the concept of endurance for extreme work environments, which we define as the capacity to sustain performance at high levels for safe and effective operations over extended durations (e.g., a mission, operation, deployment, or expedition). We integrate diverse streams of literature (e.g., work stress, recovery, and sleep) to describe endurance in terms of short- and long-term energy management processes as individuals interact with their work-life system (i.e. work, non-work, and sleep environment). We conclude with theoretical and practical implications for a better understanding of endurance, such as considering multiple time perspectives, and the role that researchers, practitioners, and organizations can play in optimizing endurance in the field.


1990 ◽  
Vol 20 (10) ◽  
pp. 1593-1601 ◽  
Author(s):  
John Van Sickle ◽  
Stanley V. Gregory

A probabilistic model predicts means and variances of the total number and volume of large woody debris pieces falling into a stream reach per unit time. The estimates of debris input are based on the density (trees/area), tree size distribution, and tree-fall probability of the riparian stand adjacent to the reach. Distributions of volume, length, and orientation of delivered debris pieces are also predicted. The model is applied to an old-growth coniferous stand in Oregon's Cascade Mountains. Observed debris inputs from the riparian stand exceeded the inputs predicted from tree mortality rates typical of similar nonriparian stands. Debris pieces observed in the stream were generally shorter, with less volume per piece, than those predicted by the model, probably because of bole breakage during tree fall. As a second application, predicted debris inputs from riparian management zones of various widths are compared with the input expected from an unharvested stand.


2005 ◽  
Vol 210 (1-3) ◽  
pp. 363-373 ◽  
Author(s):  
Niklas Dahlström ◽  
Karin Jönsson ◽  
Christer Nilsson

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