Feasibility of Passive Integrated Transponder Technology to Study In Situ Movements of Larval Sea Lamprey

2014 ◽  
Vol 6 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Heather A. Dawson ◽  
Danielle D. Potts ◽  
Alexander C. Maguffee ◽  
Lisa M. O'Connor

Abstract In the Laurentian Great Lakes, sea lamprey Petromyzon marinus is an invasive species controlled primarily through application of selective toxicants (lampricides) to tributaries expected to contain the most large larvae (>100 mm). Current assessment techniques make the assumption that larvae occupy all stream habitats in the same proportion irrespective of size or life history stage. Testing this assumption relies on the availability of a marking method to determine individual animal movement between habitats over time. To evaluate the feasibility of using passive integrated transponder (PIT) technology to detect sea lamprey larvae in situ, we implanted two sizes of PIT tags (8 and 9 mm) in larvae of less than 120-mm average length to assess survival, tag loss, behavior, and detectability in situ. Larval mortality and tag loss were lower when smaller tags were used, but mortalities were still high (60%) due to the small body cavity severely restricting internal tag implantation. Burrowing performance of 8-mm PIT-tagged larvae and untagged larvae was compared, and tagged larvae spent significantly more time moving (35 vs. 21 s) and more total time (71 vs. 31 s) to completely burrow into the substrate than untagged larvae. Detectability of those 8- and 9-mm PIT-tagged larvae in situ was evaluated by releasing them in a simulated stream and using a portable PIT tag antenna on three occasions to relocate them at a detection rate that ranged from 47 to 100%. Feasibility of tracking individual larval sea lamprey movements was evaluated by tagging larvae with either 9-mm PIT tags, visible implant alpha tags, or visible implant elastomer tags; releasing them in a natural stream; and relocating them by PIT antenna or recapturing them by electrofishing. In the natural stream, a total of 36% of 9-mm PIT-tagged larvae were relocated in situ during the study period, whereas less than 7% of larvae tagged with other tag types were recaptured. The smallest currently available PIT tags are not suitable for tracking movements of individual sea lamprey larvae less than 120 mm in average length because of the significant effects of tagging on behavior and survival rates. We are unaware of other tagging technologies currently available to track individual sea lamprey larvae of this size range in situ over time.

2021 ◽  
Vol 13 (3) ◽  
pp. 1505
Author(s):  
Ignacio Menéndez Pidal ◽  
Jose Antonio Mancebo Piqueras ◽  
Eugenio Sanz Pérez ◽  
Clemente Sáenz Sanz

Many of the large number of underground works constructed or under construction in recent years are in unfavorable terrains facing unusual situations and construction conditions. This is the case of the subject under study in this paper: a tunnel excavated in evaporitic rocks that experienced significant karstification problems very quickly over time. As a result of this situation, the causes that may underlie this rapid karstification are investigated and a novel methodology is presented in civil engineering where the use of saturation indices for the different mineral specimens present has been crucial. The drainage of the rock massif of El Regajal (Madrid-Toledo, Spain, in the Madrid-Valencia high-speed train line) was studied and permitted the in-situ study of the hydrogeochemical evolution of water flow in the Miocene evaporitic materials of the Tajo Basin as a full-scale testing laboratory, that are conforms as a whole, a single aquifer. The work provides a novel methodology based on the calculation of activities through the hydrogeochemical study of water samples in different piezometers, estimating the saturation index of different saline materials and the dissolution capacity of the brine, which is surprisingly very high despite the high electrical conductivity. The circulating brine appears unsaturated with respect to thenardite, mirabilite, epsomite, glauberite, and halite. The alteration of the underground flow and the consequent renewal of the water of the aquifer by the infiltration water of rain and irrigation is the cause of the hydrogeochemical imbalance and the modification of the characteristics of the massif. These modifications include very important loss of material by dissolution, altering the resistance of the terrain and the increase of the porosity. Simultaneously, different expansive and recrystallization processes that decrease the porosity of the massif were identified in the present work. The hydrogeochemical study allows the evolution of these phenomena to be followed over time, and this, in turn, may facilitate the implementation of preventive works in civil engineering.


Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 551-558 ◽  
Author(s):  
G. A. Ridge ◽  
S. N. Jeffers ◽  
W. C. Bridges ◽  
S. A. White

The goal of this study was to develop a procedure that could be used to evaluate the potential susceptibility of aquatic plants used in constructed wetlands to species of Phytophthora commonly found in nurseries. V8 agar plugs from actively growing cultures of three or four isolates of Phytophthora cinnamomi, P. citrophthora, P. cryptogea, P. nicotianae, and P. palmivora were used to produce inocula. In a laboratory experiment, plugs were placed in plastic cups and covered with 1.5% nonsterile soil extract solution (SES) for 29 days, and zoospore presence and activity in the solution were monitored at 2- or 3-day intervals with a rhododendron leaf disk baiting bioassay. In a greenhouse experiment, plugs of each species of Phytophthora were placed in plastic pots and covered with either SES or Milli-Q water for 13 days during both summer and winter months, and zoospore presence in the solutions were monitored at 3-day intervals with the baiting bioassay and by filtration. Zoospores were present in solutions throughout the 29-day and 13-day experimental periods but consistency of zoospore release varied by species. In the laboratory experiment, colonization of leaf baits decreased over time for some species and often varied among isolates within a species. In the greenhouse experiment, bait colonization decreased over time in both summer and winter, varied among species of Phytophthora in the winter, and was better in Milli-Q water. Zoospore densities in solutions were greater in the summer than in the winter. Decreased zoospore activities for some species of Phytophthora were associated with prolonged temperatures below 13 or above 30°C in the greenhouse. Zoospores from plugs were released consistently in aqueous solutions for at least 13 days. This procedure can be used to provide in situ inocula for the five species of Phytophthora used in this study so that aquatic plant species can be evaluated for potential susceptibility.


2021 ◽  
Vol 13 (9) ◽  
pp. 1846
Author(s):  
Vivek Kumar ◽  
Isabel M. Morris ◽  
Santiago A. Lopez ◽  
Branko Glisic

Estimating variations in material properties over space and time is essential for the purposes of structural health monitoring (SHM), mandated inspection, and insurance of civil infrastructure. Properties such as compressive strength evolve over time and are reflective of the overall condition of the aging infrastructure. Concrete structures pose an additional challenge due to the inherent spatial variability of material properties over large length scales. In recent years, nondestructive approaches such as rebound hammer and ultrasonic velocity have been used to determine the in situ material properties of concrete with a focus on the compressive strength. However, these methods require personnel expertise, careful data collection, and high investment. This paper presents a novel approach using ground penetrating radar (GPR) to estimate the variability of in situ material properties over time and space for assessment of concrete bridges. The results show that attributes (or features) of the GPR data such as raw average amplitudes can be used to identify differences in compressive strength across the deck of a concrete bridge. Attributes such as instantaneous amplitudes and intensity of reflected waves are useful in predicting the material properties such as compressive strength, porosity, and density. For compressive strength, one alternative approach of the Maturity Index (MI) was used to estimate the present values and compare with GPR estimated values. The results show that GPR attributes could be successfully used for identifying spatial and temporal variation of concrete properties. Finally, discussions are presented regarding their suitability and limitations for field applications.


Author(s):  
Stephanie A. Getty ◽  
Jason P. Dworkin ◽  
Daniel P. Glavin ◽  
Mildred Martin ◽  
Yun Zheng ◽  
...  

Author(s):  
Justin A. Atchison ◽  
Ryan H. Mitch ◽  
Clint Apland ◽  
Calvin L. Kee ◽  
Ken W. Harclerode
Keyword(s):  

2021 ◽  
Vol 50 (1) ◽  
pp. 125-143
Author(s):  
Ronald J. Clarke ◽  
Travis Rayne Pickering ◽  
Jason L. Heaton ◽  
Kathleen Kuman

The earliest South African hominids (humans and their ancestral kin) belong to the genera Australopithecus, Paranthropus, and Homo, with the oldest being a ca. 3.67 million-year-old nearly complete skeleton of Australopithecus (StW 573) from Sterkfontein Caves. This skeleton has provided, for the first time in almost a century of research, the full anatomy of an Australopithecus individual with indisputably associated skull and postcranial bones that give complete limb lengths. The three genera are also found in East Africa, but scholars have disagreed on the taxonomic assignment for some fossils owing to historical preconceptions. Here we focus on the South African representatives to help clarify these debates. The uncovering of the StW 573 skeleton in situ revealed significant clues concerning events that had affected it over time and demonstrated that the associated stalagmite flowstones cannot provide direct dating of the fossil, as they are infillings of voids caused by postdepositional collapse.


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