Low-Cost Long-Term Monitoring of Global Climate Forcings and Feedbacks

AbstractSubtropical ocean gyres play a key role in modulating the global climate system redistributing energy between low and high latitudes. A poleward displacement of the subtropical gyres has been observed over the last decades, but the lack of long-term monitoring data hinders an in-depth understanding of their dynamics. Paleoceanographic records offer the opportunity to identify meridional changes in the subtropical gyres and investigate their consequences to the climate system. Here we use the abundance of planktonic foraminiferal species Globorotalia truncatulinodes from a sediment core collected at the northernmost boundary of the South Atlantic Subtropical Gyre (SASG) together with a previously published record of the same species from the southernmost boundary of the SASG to reconstruct meridional fluctuations of the SASG over last ca. 70 kyr. Our findings indicate southward displacements of the SASG during Heinrich Stadials (HS) 6-4 and HS1, and a contraction of the SASG during HS3 and HS2. During HS6-4 and HS1, the SASG southward displacements likely boosted the transfer of heat to the Southern Ocean, ultimately strengthening deep-water upwelling and CO2 release to the atmosphere. We hypothesize that the ongoing SASG poleward displacement may further increase oceanic CO2 release.

Download Full-text

Long-Term Monitoring of Atrazine Contamination in Soil by ELISA

Journal of AOAC International ◽

10.1093/jaoac/84.1.150 ◽

2001 ◽

Vol 84 (1) ◽

pp. 150-155 ◽

Cited By ~ 4

Author(s):

Karl Kramer ◽

Johann Lepschy ◽

Bertold Hock

Keyword(s):

Low Cost ◽

Threshold Value ◽

Soil Samples ◽

Sample Throughput ◽

Atrazine Contamination ◽

Long Term Monitoring ◽

Term Monitoring ◽

Selection Of ◽

Hplc Data

Abstract An enzyme-linked immunoassay (ELISA) was used for screening atrazine residues in soil. Samples were annually collected in Southern Germany between 1993 and 1998. An average of 419.5 samples was analyzed per year amounting to 2517 samples. The fraction of positive samples defined by atrazine concentrations >100 μg/kg soil decreased successively from 8% (corresponding to 33 samples) in 1993 to 0.6% (corresponding to 2 samples) in 1998. All positive samples and a selection of negative samples were subsequently validated by HPLC. Comparison of ELISA and HPLC data yielded correlation coefficient values of r= 0.958–0.981 (n= 18–47), except for 1995 when only a correlation of r= 0.864 (n= 18) was obtained. Four samples were overestimated and another 4 were underestimated with respect to the atrazine threshold value of 100 μg/kg soil as revealed by HPLC validation. Thus, 99.68% of 2517 analyzed samples were correctly evaluated. The precision and reproducibility of the ELISA were adequate for a prescreening tool. The low cost per sample and the high sample throughput are not yet achievable by conventional analytical methods. The described combination of ELISA and HPLC has the potential to take advantage of both methods and to restrict determination errors to a minimum.

Download Full-text

Diversity of Biological Communities Along the Major Rivers of Sundarbans in Bangladesh

Asian Fisheries Science ◽

10.33997/j.afs.2021.34.2.002 ◽

2021 ◽

Vol 34 (2) ◽

Author(s):

MD. NAGIM UDDIN ◽

ISRAT JAHAN TUMPA ◽

ZAKIR HOSSAIN ◽

Keyword(s):

Global Climate ◽

Monsoon Season ◽

Diversity Indices ◽

Biological Communities ◽

Fisheries Resources ◽

Post Monsoon Season ◽

Long Term Monitoring ◽

Zooplankton Communities ◽

Term Monitoring

Despite recent unexpected and irreversible changes in the environment brought on by global climate change, the largest mangrove forest of Sundarbans is still considered a biodiversity hotspot in Bangladesh. This study aimed to assess the abundance, diversity indices and richness of plankton and fisheries resources of the four major rivers (Pasur, Sela, Sibsa, and Kapotakkho) in Sundarbans. During the study period (July 2017 to November 2018), the range of pH, temperature, salinity and dissolved oxygen values were from 7.1 to 8.7, 25 °C to 32.8 °C, 1.5 ‰ to 23 ‰ and 4.3 mg.L-1 to 7.7 mg.L-1 , respectively. Phytoplankton and zooplankton communities were represented by 29 and 18 species, respectively. The number of plankton per litre was highest in the Pasur River during both pre-monsoon and post-monsoon season. A total of 186 species of fish and crustaceans were recorded in the rivers of Sundarbans. The plankton, fish and crustacean diversity indices were as follows: Shannon-Wiener diversity (1.22 ± 0.27 to 3.48 ± 0.22), Margalef’s richness (1.29 ± 0.33 to 4.56 ± 0.45) and Pielou’s evenness (0.94 ± 0.04 to 1.02 ± 0.04). The results of the present study underscore new insight on riverine biological communities of the Sundarbans and emphasise the need for long-term monitoring in this ecologically fragile ecosystem.

Download Full-text

Comparison of low cost measurement techniques for long-term monitoring of atmospheric ammonia

Journal of Environmental Monitoring ◽

10.1039/b102303a ◽

2001 ◽

Vol 3 (5) ◽

pp. 446-453 ◽

Cited By ~ 35

Author(s):

M. A. Sutton ◽

B. Miners ◽

Y. S. Tang ◽

C. Milford ◽

G. P. Wyers ◽

...

Keyword(s):

Low Cost ◽

Measurement Techniques ◽

Atmospheric Ammonia ◽

Cost Measurement ◽

Long Term Monitoring ◽

Term Monitoring

Download Full-text

Meridional Changes in The South Atlantic Subtropical Gyre During Heinrich Stadials

10.21203/rs.3.rs-115324/v1 ◽

2020 ◽

Author(s):

Tainã Pinho ◽

Cristiano Chiessi ◽

Rodrigo Portilho-Ramos ◽

Marília Campos ◽

Stefano Crivellari ◽

...

Keyword(s):

Global Climate ◽

South Atlantic ◽

Subtropical Gyre ◽

Climate System ◽

The South ◽

Foraminiferal Species ◽

Ocean Gyres ◽

Long Term Monitoring ◽

Term Monitoring

Abstract Subtropical ocean gyres play a key role in modulating the global climate system redistributing energy between low and high latitudes. A poleward displacement of the subtropical gyres has been observed over the last decades, but the lack of long-term monitoring data hinders an in-depth understanding of their dynamics. Paleoceanographic records offer the opportunity to identify meridional changes in the subtropical gyres and investigate their consequences to the climate system. Here we use the abundance of planktonic foraminiferal species Globorotalia truncatulinodes from a sediment core collected at the northernmost boundary of the South Atlantic Subtropical Gyre (SASG) together with a previously published record of the same species from the southernmost boundary of the SASG to reconstruct meridional fluctuations of the SASG over last ca. 70 kyr. Our findings indicate southward displacements of the SASG during Heinrich Stadials (HS) 6-4 and HS1, and a contraction of the SASG during HS3 and HS2. During HS6-4 and HS1, the SASG southward displacements likely boosted the transfer of heat to the Southern Ocean, ultimately strengthening deep-water upwelling and CO2 release to the atmosphere. We hypothesize that the ongoing SASG poleward displacement may further increase oceanic CO2 release.

Download Full-text

Development of an Inverted Epifluorescence Microscope for Long-Term Monitoring of Bacteria in Multiplexed Microfluidic Devices

Sensors ◽

10.3390/s20154140 ◽

2020 ◽

Vol 20 (15) ◽

pp. 4140

Author(s):

Amaro Torres-Simón ◽

María Henar Marino ◽

Clara Gómez-Cruz ◽

Marina Cañadas ◽

Miguel Marco ◽

...

Keyword(s):

Single Cell ◽

Bacterial Resistance ◽

Single Cell Analysis ◽

Low Cost ◽

Microfluidic Devices ◽

Cell Analysis ◽

Antibiotic Development ◽

Long Term Monitoring ◽

Term Monitoring

Developing more efficient methods for antibiotic susceptibility testing is a pressing issue in novel drug development as bacterial resistance to antibiotics becomes increasingly common. Microfluidic devices have been demonstrated to be powerful platforms that allow researchers to perform multiplexed antibiotic testing. However, the level of multiplexing within microdevices is limited, evidencing the need of creating simple, low-cost and high-resolution imaging systems that can be integrated in antibiotic development pipelines. This paper describes the design and development of an epifluorescence inverted microscope that enables long-term monitoring of bacteria inside multiplexed microfluidic devices. The goal of this work is to provide a simple microscope powerful enough to allow single-cell analysis of bacteria at a reduced cost. This facilitates increasing the number of microscopes that are simultaneously used for antibiotic testing. We prove that the designed system is able to accurately detect fluorescent beads of 100 nm, demonstrating comparable features to high-end commercial microscopes and effectively achieving the resolution required for single-cell analysis of bacteria. The proposed microscope could thus increase the efficiency in antibiotic testing while reducing cost, size, weight, and power requirements, contributing to the successful development of new antibiotic drugs.

Download Full-text