Fluctuating asymmetry in fishes inhabiting acidified and unacidified lakes

1985 ◽  
Vol 63 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Charles H. Jagoe ◽  
Terry A. Haines
Keyword(s):  
Fluctuating Asymmetry ◽  
Brook Trout ◽  
Bilateral Symmetry ◽  
Causal Link ◽  
Morphometric Characters ◽  
Ph Values ◽  
Random Deviation ◽  
Wide Range ◽  
Left And Right ◽  
Decreasing Ph

Fluctuating asymmetry, the random deviation from perfect bilateral symmetry owing to developmental perturbation, has been used in a number of studies to quantify stress during early life. Decreasing pH and related changes in aquatic environments owing to input of anthropogenic acids have been demonstrated to be physiologically stressful to many fish species. Therefore, a link between environmental acidification and fluctuating asymmetry was postulated. Brook trout (Salvelinus fontinalis), white sucker (Catostomus commersoni), and lake chub (Couesis plumbeus) were collected from lakes over a wide range of pH values. Use of several species allowed separate consideration of environmental and genetic effects. Depending on species, 15 to 20 paired meristic and morphometric characters were scored for the left and right sides of each individual. Differences between sides were calculated and analyzed by a variety of statistical methods. Most characters examined were not significantly more asymmetric in acidified lakes. However, one or two characters in each species were more asymmetric in lakes of lower pH. Relative overall asymmetry in brook trout was related to parameters that changed with acidification. The small number of locations sampled precluded such an analysis in the other two species. The results are consistent with the hypothetical link between environmental stress by acidification and increased fluctuating asymmetry, but the connection is much weaker than expected. This finding, the need for large sample sizes, and the lack of a definite causal link, severely limits the utility of this type of analysis in assessing the level of stress in fish populations.

Developmental stability in perch (Perca fluviatilis) in acidic aluminium-rich lakes

1997 ◽  
Vol 75 (6) ◽  
pp. 919-928 ◽  
Author(s):  
Kjartan Østbye ◽  
Sigurd A. Øxnevad ◽  
Leif Asbjørn Vøllestad
Keyword(s):  
Fluctuating Asymmetry ◽  
Age Groups ◽  
Perca Fluviatilis ◽  
Bilateral Symmetry ◽  
Developmental Instability ◽  
Management Tool ◽  
Meristic Characters ◽  
Morphometric Characters ◽  
Perch Perca Fluviatilis ◽  
Developmental Noise

Fluctuating asymmetry is defined as random deviation from perfect bilateral symmetry resulting from environmental or genetic disturbances (termed developmental noise) during early embryonic development. Developmental instability is defined as the inability of an organism to follow the a priori defined growth trajectory that results in perfect bilateral symmetry, owing to insufficient buffering of the disruptive effects of developmental noise during development. Fluctuating asymmetry has been proposed for use as a measure of developmental instability. In this study we tested whether fluctuating asymmetry can be an early indication of acidification stress. Samples were taken from 10 perch (Perca fluviatilis) populations exposed to varying pH levels and aluminium concentrations. We scored 13 bilateral meristic and morphometric characters to assess fluctuating asymmetry. The level of fluctuating asymmetry in the mandibular pores and one index summarizing three of the meristic characters were significantly correlated with the acidification level. When the lakes were split into two groups, "acidified" and "control," each consisting of five lakes, the same pattern emerged. The variance of fluctuating asymmetry estimates was larger in the acidified lakes than in the control lakes. These findings imply that perch in acidic environments experience developmental perturbations during early embryogenesis, resulting in deviating bilateral morphology. The variation in fluctuating asymmetry among lakes was at the same level as previously found among age groups within one acidified lake. Based on these findings, the use of fluctuating asymmetry as a management tool to evaluate the viability of fish populations in acidified waters is of limited value unless a more comprehensive approach is used.

scholarly journals Otolith fluctuating asymmetry: a misconception of its biological relevance?

2015 ◽  
Vol 72 (7) ◽  
pp. 2079-2089 ◽  
Author(s):  
Carlos Díaz-Gil ◽  
Miquel Palmer ◽  
Ignacio A. Catalán ◽  
Josep Alós ◽  
Lee A. Fuiman ◽  
...  
Keyword(s):  
Fluctuating Asymmetry ◽  
Bilateral Symmetry ◽  
Field Studies ◽  
Experimental Designs ◽  
Wild Populations ◽  
Negative Results ◽  
Individual Fitness ◽  
Wide Range ◽  
Hard Structures ◽  
Shed Light

Abstract For decades, disruption of the bilateral symmetry of body structures has been related to underperformance and, hence, to fitness. In fish, this concept coupled with the claimed evidence for increased fluctuating asymmetry (FA) of pairs of hard structures, such as otoliths under conditions of stress, has led to the use of otolith FA (OFA) as a proxy for individual fitness and population success. Interpreting those significant differences in OFA in relation to stress-inducing environments and using them to identify suboptimal conditions for survival is especially appealing in the context of, for example, assessing climate change using historical otolith collections. Despite several works that give evidence to support the usefulness of OFA approach, we report on a number of unpublished and published datasets from a wide range of both, wild populations and experimental designs that show no correlation between OFA and any of the usual indicators of fitness or between OFA and expected stress gradients. Our results suggest that there may be a strong bias in the published literature towards positive relationships, despite the enormous importance of negative results for understanding the significance of OFA. These results might shed light on the interpretability of OFA in both laboratory and field studies.

Nitrogen Removal from Anaerobically-Treated Leachate

1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis
Keyword(s):  
Nitrogen Removal ◽  
Air Flow ◽  
Operating Conditions ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Anaerobic Filter ◽  
Ph Values ◽  
Wide Range ◽  
Ammonia Desorption ◽  
Effects Of Ph

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.

scholarly journals Changes in Water Quality of the River das Antas as It Passes through Rural and Urban Areas

Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Valdemir Antoneli ◽  
Manuel Pulido-Fernández ◽  
João Anésio Bednarz ◽  
Leonardo Brandes ◽  
Michael Vrahnakis ◽  
...  
Keyword(s):  
Rural Area ◽  
Urban Areas ◽  
Human Consumption ◽  
Rural And Urban Areas ◽  
Ph Values ◽  
Rural And Urban ◽  
Feasible Option ◽  
Decreasing Ph ◽  
The City

The catchment area of River das Antas (Irati, Paraná, Brazil) is of high importance both for human consumption and irrigation. Within Irati, this river passes through a rural area and through the city of Irati, crossing both poor and rich neighbourhoods. We selected three study areas downstream (a rural area, poor community, and rich neighbourhood) in which we measured turbidity, the concentration of sediments and pH during rainy days. Our results showed downstream trends of increasing turbidity and concentrations of sediments with decreasing pH. The values of turbidity and of concentration of sediments were significantly different in the rural area, while the pH values were significantly different between the three study areas. These findings highlight the effect of agricultural activities in the generation of sediments and turbidity. The—presumably expected—effects of organic urban waste from the poor neighbourhood were also detected in the pH values. We conclude that efforts should be made to ensure that land planning and training/education programmes on sustainable farming practices are undertaken by the authorities to reduce water pollution and its effects on water bodies during rainfall events, since paving streets is not a feasible option in the short term due to the high costs associated with this measure.

scholarly journals Syllabification of the Divine Comedy

2021 ◽  
Vol 14 (3) ◽  
pp. 1-26
Author(s):  
Andrea Asperti ◽  
Stefano Dal Bianco
Keyword(s):  
Text Processing ◽  
Solution Space ◽  
Generative Models ◽  
Divine Comedy ◽  
Point Of View ◽  
Computer Assisted ◽  
Wide Range ◽  
The Divine Comedy ◽  
Left And Right ◽  
Assisted Analysis

We provide a syllabification algorithm for the Divine Comedy using techniques from probabilistic and constraint programming. We particularly focus on the synalephe , addressed in terms of the "propensity" of a word to take part in a synalephe with adjacent words. We jointly provide an online vocabulary containing, for each word, information about its syllabification, the location of the tonic accent, and the aforementioned synalephe propensity, on the left and right sides. The algorithm is intrinsically nondeterministic, producing different possible syllabifications for each verse, with different likelihoods; metric constraints relative to accents on the 10th, 4th, and 6th syllables are used to further reduce the solution space. The most likely syllabification is hence returned as output. We believe that this work could be a major milestone for a lot of different investigations. From the point of view of digital humanities it opens new perspectives on computer-assisted analysis of digital sources, comprising automated detection of anomalous and problematic cases, metric clustering of verses and their categorization, or more foundational investigations addressing, e.g., the phonetic roles of consonants and vowels. From the point of view of text processing and deep learning, information about syllabification and the location of accents opens a wide range of exciting perspectives, from the possibility of automatic learning syllabification of words and verses to the improvement of generative models, aware of metric issues, and more respectful of the expected musicality.

scholarly journals Searching for Z′ bosons at the P2 experiment

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
P. S. Bhupal Dev ◽  
Werner Rodejohann ◽  
Xun-Jie Xu ◽  
Yongchao Zhang
Keyword(s):  
Parity Violation ◽  
Z Bosons ◽  
Gauge Coupling ◽  
New Physics ◽  
Polarized Electrons ◽  
Mixing Angles ◽  
Charge Assignment ◽  
Wide Range ◽  
Discovery Potential ◽  
Left And Right

Abstract The P2 experiment aims at high-precision measurements of the parity-violating asymmetry in elastic electron-proton and electron-12C scatterings with longitudinally polarized electrons. We discuss here the sensitivity of P2 to new physics mediated by an additional neutral gauge boson Z′ of a new U(1)′ gauge symmetry. If the charge assignment of the U(1)′ is chiral, i.e., left- and right-handed fermions have different charges under U(1)′, additional parity-violation is induced directly. On the other hand, if the U(1)′ has a non-chiral charge assignment, additional parity-violation can be induced via mass or kinetic Z-Z′ mixing. By comparing the P2 sensitivity to existing constraints, we show that in both cases P2 has discovery potential over a wide range of Z′ mass. In particular, for chiral models, the P2 experiment can probe gauge couplings at the order of 10−5 when the Z′ boson is light, and heavy Z′ bosons up to 79 (90) TeV in the proton (12C) mode. For non-chiral models with mass mixing, the P2 experiment is sensitive to mass mixing angles smaller than roughly 10−4, depending on model details and gauge coupling magnitude.

scholarly journals Hybrid Acrylated Chitosan and Thiolated Pectin Cross-Linked Hydrogels with Tunable Properties

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 266
Author(s):  
Shaked Eliyahu ◽  
Alexandra Galitsky ◽  
Esther Ritov ◽  
Havazelet Bianco-Peled
Keyword(s):  
Electrostatic Interactions ◽  
Profile Analysis ◽  
Hybrid Hydrogel ◽  
Texture Profile ◽  
Ph Values ◽  
X Ray Scattering ◽  
Wide Range ◽  
Michael Type Addition ◽  
Physical And Chemical ◽  
Hydrogel System

We developed and characterized a new hydrogel system based on the physical and chemical interactions of pectin partially modified with thiol groups and chitosan modified with acrylate end groups. Gelation occurred at high pectin thiol ratios, indicating that a low acrylated chitosan concentration in the hydrogel had a profound effect on the cross-linking. Turbidity, Fourier transform infrared spectroscopy, and free thiol determination analyses were performed to determine the relationships of the different bonds inside the gel. At low pH values below the pKa of chitosan, more electrostatic interactions were formed between opposite charges, but at high pH values, the Michael-type addition reaction between acrylate and thiol took place, creating harder hydrogels. Swelling experiments and Young’s modulus measurements were performed to study the structure and properties of the resultant hydrogels. The nanostructure was examined using small-angle X-ray scattering. The texture profile analysis showed a unique property of hydrogel adhesiveness. By implementing changes in the preparation procedure, we controlled the hydrogel properties. This hybrid hydrogel system can be a good candidate for a wide range of biomedical applications, such as a mucosal biomimetic surface for mucoadhesive testing.

scholarly journals In Vitro Incorporation of Helicobacter pylori into Candida albicans Caused by Acidic pH Stress

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 489 ◽  
Author(s):  
Kimberly Sánchez-Alonzo ◽  
Cristian Parra-Sepúlveda ◽  
Samuel Vega ◽  
Humberto Bernasconi ◽  
Víctor L. Campos ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Candida Albicans ◽  
Pcr Amplification ◽  
Growth Curves ◽  
Acidic Ph ◽  
Ph Values ◽  
16S Gene ◽  
Wide Range ◽  
H Pylori

Yeasts can adapt to a wide range of pH fluctuations (2 to 10), while Helicobacter pylori, a facultative intracellular bacterium, can adapt to a range from pH 6 to 8. This work analyzed if H. pylori J99 can protect itself from acidic pH by entering into Candida albicans ATCC 90028. Growth curves were determined for H. pylori and C. albicans at pH 3, 4, and 7. Both microorganisms were co-incubated at the same pH values, and the presence of intra-yeast bacteria was evaluated. Intra-yeast bacteria-like bodies were detected using wet mounting, and intra-yeast binding of anti-H. pylori antibodies was detected using immunofluorescence. The presence of the H. pylori rDNA 16S gene in total DNA from yeasts was demonstrated after PCR amplification. H. pylori showed larger death percentages at pH 3 and 4 than at pH 7. On the contrary, the viability of the yeast was not affected by any of the pHs evaluated. H. pylori entered into C. albicans at all the pH values assayed but to a greater extent at unfavorable pH values (pH 3 or 4, p = 0.014 and p = 0.001, respectively). In conclusion, it is possible to suggest that H. pylori can shelter itself within C. albicans under unfavorable pH conditions.

Two-Color Probe to Monitor a Wide Range of pH Values in Cells

2013 ◽  
Vol 52 (24) ◽  
pp. 6206-6209 ◽  
Author(s):  
Min Hee Lee ◽  
Ji Hye Han ◽  
Jae Hong Lee ◽  
Nayoung Park ◽  
Rajesh Kumar ◽  
...  
Keyword(s):  
Ph Values ◽  
Wide Range ◽  
In Cells

scholarly journals Phosphatase synthesis in Klebsiella (Aerobacter) aerogenes growing in continuous culture

1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Continuous Culture ◽  
Activity Profile ◽  
Glucose Effect ◽  
Ph Values ◽  
Nitrophenyl Phosphate ◽  
Wide Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.

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