scholarly journals Unexpected large evasion fluxes of carbon dioxide from turbulent streams draining the world’s mountains

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Åsa Horgby ◽  
Pier Luigi Segatto ◽  
Enrico Bertuzzo ◽  
Ronny Lauerwald ◽  
Bernhard Lehner ◽  
...  
Keyword(s):  
Regional Scale ◽  
Carbon Fluxes ◽  
Global Scale ◽  
Swiss Alps ◽  
Mountain Streams ◽  
River Networks ◽  
Active Components ◽  
Boreal Streams ◽  
Global Carbon

Abstract Inland waters, including streams and rivers, are active components of the global carbon cycle. Despite the large areal extent of the world’s mountains, the role of mountain streams for global carbon fluxes remains elusive. Using recent insights from gas exchange in turbulent streams, we found that areal CO2 evasion fluxes from mountain streams equal or exceed those reported from tropical and boreal streams, typically regarded as hotspots of aquatic carbon fluxes. At the regional scale of the Swiss Alps, we present evidence that emitted CO2 derives from lithogenic and biogenic sources within the catchment and delivered by the groundwater to the streams. At a global scale, we estimate the CO2 evasion from mountain streams to 167 ± 1.5 Tg C yr−1, which is high given their relatively low areal contribution to the global stream and river networks. Our findings shed new light on mountain streams for global carbon fluxes.

scholarly journals Role of Continental Arcs in Global Carbon Dioxide Emissions

Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Erik Klemetti
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Global Scale ◽  
Continental Arcs ◽  
Major Player ◽  
Global Carbon

Continental arcs are a major player in global carbon dioxide emissions, but quantifying that relationship is hard. A new study accepts the challenge on a global scale over 750 million years.

Optical analysis of ink and other contaminants in process waters

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI
Keyword(s):  
Optically Active ◽  
Process Water ◽  
Paper Machine ◽  
Optical Analysis ◽  
Direct Process ◽  
Active Components ◽  
Water Contaminants ◽  
Dependent Measurement ◽  
Measurement Methodology

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.

Are local losses of biodiversity causing degraded ecosystem function?

2017 ◽  
Author(s):  
Mark Vellend
Keyword(s):  
Ecosystem Function ◽  
Species Interactions ◽  
Regional Scale ◽  
Temporal Trends ◽  
Biodiversity Loss ◽  
Large Degree ◽  
Global Scale ◽  
Degraded Ecosystem ◽  
Biodiversity Change ◽  
Local Extirpation

This chapter highlights the scale dependence of biodiversity change over time and its consequences for arguments about the instrumental value of biodiversity. While biodiversity is in decline on a global scale, the temporal trends on regional and local scales include cases of biodiversity increase, no change, and decline. Environmental change, anthropogenic or otherwise, causes both local extirpation and colonization of species, and thus turnover in species composition, but not necessarily declines in biodiversity. In some situations, such as plants at the regional scale, human-mediated colonizations have greatly outnumbered extinctions, thus causing a marked increase in species richness. Since the potential influence of biodiversity on ecosystem function and services is mediated to a large degree by local or neighborhood species interactions, these results challenge the generality of the argument that biodiversity loss is putting at risk the ecosystem service benefits people receive from nature.

Innovatory role of nanomaterials as bio-tools for treatment of cancer

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Khuram Shahzad Ahmad ◽  
Muntaha Talat ◽  
Shaan Bibi Jaffri ◽  
Neelofer Shaheen
Keyword(s):  
Cancer Treatment ◽  
Cancer Therapeutics ◽  
Physicochemical Characteristics ◽  
Global Scale ◽  
Current Review ◽  
Anti Cancer ◽  
Different Types ◽  
Cancerous Cells

AbstractConventional treatment modes like chemotherapy, thermal and radiations aimed at cancerous cells eradication are marked by destruction pointing the employment of nanomaterials as sustainable and auspicious materials for saving human lives. Cancer has been deemed as the second leading cause of death on a global scale. Nanomaterials employment in cancer treatment is based on the utilization of their inherent physicochemical characteristics in addition to their modification for using as nano-carriers and nano-vehicles eluted with anti-cancer drugs. Current work has reviewed the significant role of different types of nanomaterials in cancer therapeutics and diagnostics in a systematic way. Compilation of review has been done by analyzing voluminous investigations employing ERIC, MEDLINE, NHS Evidence and Web of Science databases. Search engines used were Google scholar, Jstore and PubMed. Current review is suggestive of the remarkable performance of nanomaterials making them candidates for cancer treatment for substitution of destructive treatment modes through investigation of their physicochemical characteristics, utilization outputs and long term impacts in patients.

scholarly journals Setting the Flow Accumulation Threshold Based on Environmental and Morphologic Features to Extract River Networks from Digital Elevation Models

2021 ◽  
Vol 10 (3) ◽  
pp. 186
Author(s):  
HuiHui Zhang ◽  
Hugo A. Loáiciga ◽  
LuWei Feng ◽  
Jing He ◽  
QingYun Du
Keyword(s):  
Spatial Scales ◽  
Digital Elevation Models ◽  
Regional Scale ◽  
Drainage Density ◽  
River Network ◽  
Landscape Patterns ◽  
Estimation Methods ◽  
River Networks ◽  
Flow Accumulation ◽  
Digital Elevation

Determining the flow accumulation threshold (FAT) is a key task in the extraction of river networks from digital elevation models (DEMs). Several methods have been developed to extract river networks from Digital Elevation Models. However, few studies have considered the geomorphologic complexity in the FAT estimation and river network extraction. Recent studies estimated influencing factors’ impacts on the river length or drainage density without considering anthropogenic impacts and landscape patterns. This study contributes two FAT estimation methods. The first method explores the statistical association between FAT and 47 tentative explanatory factors. Specifically, multi-source data, including meteorologic, vegetation, anthropogenic, landscape, lithology, and topologic characteristics are incorporated into a drainage density-FAT model in basins with complex topographic and environmental characteristics. Non-negative matrix factorization (NMF) was employed to evaluate the factors’ predictive performance. The second method exploits fractal geometry theory to estimate the FAT at the regional scale, that is, in basins whose large areal extent precludes the use of basin-wide representative regression predictors. This paper’s methodology is applied to data acquired for Hubei and Qinghai Provinces, China, from 2001 through 2018 and systematically tested with visual and statistical criteria. Our results reveal key local features useful for river network extraction within the context of complex geomorphologic characteristics at relatively small spatial scales and establish the importance of properly choosing explanatory geomorphologic characteristics in river network extraction. The multifractal method exhibits more accurate extracting results than the box-counting method at the regional scale.

scholarly journals CO2 dynamics and heterogeneity in a cave atmosphere: role of ventilation patterns and airflow pathways

2021 ◽  
Author(s):  
Lovel Kukuljan ◽  
Franci Gabrovšek ◽  
Matthew D. Covington ◽  
Vanessa E. Johnston
Keyword(s):  
Temporal Variations ◽  
Observation Point ◽  
Spatially Distributed ◽  
Combined Action ◽  
Karst Systems ◽  
The Relationship ◽  
Co2 Dynamics ◽  
Global Carbon

AbstractUnderstanding the dynamics and distribution of CO2 in the subsurface atmosphere of carbonate karst massifs provides important insights into dissolution and precipitation processes, the role of karst systems in the global carbon cycle, and the use of speleothems for paleoclimate reconstructions. We discuss long-term microclimatic observations in a passage of Postojna Cave, Slovenia, focusing on high spatial and temporal variations of pCO2. We show (1) that the airflow through the massif is determined by the combined action of the chimney effect and external winds and (2) that the relationship between the direction of the airflow, the geometry of the airflow pathways, and the position of the observation point explains the observed variations of pCO2. Namely, in the terminal chamber of the passage, the pCO2 is low and uniform during updraft, when outside air flows to the site through a system of large open galleries. When the airflow reverses direction to downdraft, the chamber is fed by inlets with diverse flow rates and pCO2, which enter via small conduits and fractures embedded in a CO2-rich vadose zone. If the spatial distribution of inlets and outlets produces minimal mixing between low and high pCO2 inflows, high and persistent gradients in pCO2 are formed. Such is the case in the chamber, where vertical gradients of up to 1000 ppm/m are observed during downdraft. The results presented in this work provide new insights into the dynamics and composition of the subsurface atmosphere and demonstrate the importance of long-term and spatially distributed observations.

scholarly journals Broken Worlds: Towards an Archaeology of the Shatter Zone

2021 ◽  
Author(s):  
Ben Raffield
Keyword(s):  
Eighteenth Century ◽  
Global Scale ◽  
Physical Geography ◽  
Trigger Factors ◽  
Eastern Woodlands ◽  
Term Change ◽  
Anthropological Research ◽  
Historic Change

AbstractIn recent years, archaeological studies of long-term change and transformation in the human past have often been dominated by the discussion of dichotomous processes of ‘collapse’ and ‘resilience’. These discussions are frequently framed in relatively narrow terms dictated by specialist interests that place an emphasis on the role of single ‘trigger’ factors as motors for historic change. In order to address this issue, in this article I propose that the study of the ‘shatter zone’—a term with origins in physical geography and geopolitics that has been more recently harnessed in anthropological research—has the potential to facilitate multi-scalar, interdisciplinary analyses of the ways in which major historical changes unfold across both space and time, at local, regional, and inter-regional levels. This article unpacks the concept of the shatter zone and aligns this with existing archaeological frameworks for the study of long-term adaptive change. I then situate these arguments within the context of recent studies of colonial interaction and conflict in the Eastern Woodlands of North America during the sixteenth to eighteenth century. The study demonstrates how a more regulated approach to the shatter zone has the potential to yield new insights on the ways in which populations mitigate and react to instability and change while also facilitating comparative studies of these processes on a broader, global scale.

scholarly journals Surveying Potential Vectors of Apple Proliferation Phytoplasma: Faunistic Analysis and Infection Status of Selected Auchenorrhyncha Species

Insects ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Stefanie Fischnaller ◽  
Martin Parth ◽  
Manuel Messner ◽  
Robert Stocker ◽  
Christine Kerschbamer ◽  
...  
Keyword(s):  
New Records ◽  
Regional Scale ◽  
Insect Vectors ◽  
Infection Status ◽  
Apple Proliferation ◽  
Population Densities ◽  
South Tyrol ◽  
Candidatus Phytoplasma Mali ◽  
Cacopsylla Melanoneura

Apple proliferation (AP) is one of the economically most important diseases in European apple cultivation. The disease is caused by the cell-wall-less bacterium ’ Candidatus Phytoplasma mali’, which is transmitted by Cacopsylla picta (Foerster) and Cacopsylla melanoneura (Foerster) (Hemiptera: Psylloidea). In South Tyrol (Italy), severe outbreaks were documented since the 1990s. Infestation rates of AP do not always correlate with the population densities of the confirmed vectors, implying the presence of other, so far unknown, hemipterian vectors. By elucidating the species community of Auchenorrhyncha (Insecta: Hemiptera) at a regional scale, more than 31,000 specimens were captured in South Tyrolean apple orchards. The occurrence of 95 species was confirmed, whereas fourteen species are new records for this territory. Based on the faunistical data, more than 3600 individuals out of 25 species were analyzed using quantitative PCR to assess the presence of AP phytoplasma. The pathogen was sporadically detected in some individuals of different species, for example in Stictocephala bisonia Kopp and Yonk (Hemiptera: Membracidae). However, the concentration of phytoplasma was much lower than in infected C. picta and C. melanoneura captured in the same region, confirming the role of the latter mentioned psyllids as the main insect vectors of AP- phytoplasma in South Tyrol.

scholarly journals Post-Translational Modifications Drive Success and Failure of Fungal–Host Interactions

2021 ◽  
Vol 7 (2) ◽  
pp. 124
Author(s):  
Charmaine Retanal ◽  
Brianna Ball ◽  
Jennifer Geddes-McAlister
Keyword(s):  
Fungal Pathogens ◽  
Fungal Infections ◽  
Treatment Options ◽  
Global Scale ◽  
Host Cells ◽  
Candida Spp ◽  
Post Translational Modifications ◽  
Fungal Host ◽  
Resistant Species

Post-translational modifications (PTMs) change the structure and function of proteins and regulate a diverse array of biological processes. Fungal pathogens rely on PTMs to modulate protein production and activity during infection, manipulate the host response, and ultimately, promote fungal survival. Given the high mortality rates of fungal infections on a global scale, along with the emergence of antifungal-resistant species, identifying new treatment options is critical. In this review, we focus on the role of PTMs (e.g., phosphorylation, acetylation, ubiquitination, glycosylation, and methylation) among the highly prevalent and medically relevant fungal pathogens, Candida spp., Aspergillus spp., and Cryptococcus spp. We explore the role of PTMs in fungal stress response and host adaptation, the use of PTMs to manipulate host cells and the immune system upon fungal invasion, and the importance of PTMs in conferring antifungal resistance. We also provide a critical view on the current knowledgebase, pose questions key to our understanding of the intricate roles of PTMs within fungal pathogens, and provide research opportunities to uncover new therapeutic strategies.

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