scholarly journals Nutrient Regulation of Relative Dominance of Cylindrospermopsin-Producing and Non-cylindrospermopsin-Producing Raphidiopsis raciborskii

2021 ◽  
Vol 12 ◽  
Author(s):  
Lamei Lei ◽  
Minting Lei ◽  
Nan Cheng ◽  
Zhijiang Chen ◽  
Lijuan Xiao ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Field Survey ◽  
Global Scale ◽  
Field Investigation ◽  
Culture Conditions ◽  
Cylindrospermopsis Raciborskii ◽  
Nutrient Regulation ◽  
Relative Dominance ◽  
The Relationship ◽  
Natural Water Bodies

Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) can produce cylindrospermopsin (CYN) which is of great concern due to its considerable toxicity to human and animals. Its CYN-producing (toxic) and non-CYN-producing (non-toxic) strains co-exist commonly in natural water bodies, while how their relative dominance is regulated has not been addressed. In this study, we combined field investigation with laboratory experiments to assessed the relationship between toxic and non-toxic R. raciborskii abundances under different nutrient levels. The rpoC1- and cyrJ-based qPCR was applied for quantifying total and toxic R. raciborskii abundances, respectively. The field survey showed that toxic R. raciborskii was detected in 97 of 115 reservoirs where its proportion ranged from 0.3% to 39.7% within the R. raciborskii population. Both total and toxic R. raciborskii abundances increased significantly with trophic level of these reservoirs, consistent with our monoculture and co-culture experiments showing in an increase in R. raciborskii growth with increasing nitrogen (N) or phosphorus (P) concentrations. In the monoculture experiments, growth rates of non-toxic and toxic strains from Australia or China were not significantly different under the same culture conditions. On the other hand, in the co-culture experiments, the toxic strains displayed a significantly faster growth than non-toxic strains under nutrient-replete conditions, resulting in an obvious shift toward the dominance by toxic strains from day 3 to the end of the experiments, regardless of the strain originating from Australia or China. The reverse was found under N- or P-limited conditions. Our results indicated that the toxic strains of R. raciborskii have a competitive advantage relative to the non-toxic strains in a more eutrophic world. In parallel to an increase in dominance, both toxic strains grown in the mixed population significantly increased CYN production under nutrient-replete conditions as compared to nutrient-limited conditions, suggesting that CYN may be of significance for ecological advantage of toxic R. raciborskii. These results highlight the importance of nutrient availability in regulating abundances and strain dominance of two genotypes of R. raciborskii. Our findings demonstrated that elevated nutrients would favor the growth of CYN-producing R. raciborskii and CYN production, leading to more blooms with higher toxicity at global scale.

Behaviour of Coli Phages in Oxidation Ponds

1985 ◽  
Vol 17 (10) ◽  
pp. 219-227 ◽  
Author(s):  
T. Omura ◽  
H. K. Shin ◽  
A. Ketratanakul
Keyword(s):  
Laboratory Experiments ◽  
Field Investigation ◽  
Host Cells ◽  
Coliform Bacteria ◽  
Alkaline Ph ◽  
Viral Inactivation ◽  
Effects Of Temperature ◽  
Oxidation Ponds ◽  
Incubation Temperatures ◽  
Inactivation Efficiency

Coliphages are among the most promising indicators of viral inactivation efficiency of wastewater treatment. Therefore, it is important to investigate the behaviour of coliphages in oxidation ponds from the viewpoint of predicting the inactivation of infectious viruses. In this study, numbers of coliphages were measured in oxidation ponds consisting of a series of facultative and maturation ponds. In parallel with this investigation, the effects of temperature and pH on the behaviour of coliphages were examined in the laboratory, employing three species of coliform bacteria as host cells. The field investigation showed that there was positive correlation between counts of coliphages and those of coliform bacteria, and that more than 99% of coliphages were inactivated. The inactivation efficiency of coliphages in the facultative pond was much higher than in the maturation pond. The results of the laboratory experiments indicated that at 30°C more than 99% of the coliform group were destroyed in 7 days of incubation and that coliphages counts increased from 105/100 ml to 107/100 ml with a lag time of 3 days. Greater reduction of the coliform count was obtained at higher incubation temperatures. It was observed that the coliphages possessed greater ability to attack coliform bacteria at acidic rather than alkaline pH.

Consistency of patterns between laboratory experiments and field collected fish in otolith chemistry: an example and applications for salinity reconstructions

2005 ◽  
Vol 56 (5) ◽  
pp. 609 ◽  
Author(s):  
T. S. Elsdon ◽  
B. M. Gillanders
Keyword(s):  
Environmental Variables ◽  
Laboratory Experiments ◽  
Juvenile Fish ◽  
Otolith Chemistry ◽  
Ambient Water ◽  
Elemental Concentrations ◽  
Adequate Knowledge ◽  
Black Bream ◽  
Environmental Histories ◽  
The Relationship

Elemental concentrations within fish otoliths can track movements and migrations of fish through gradients of environmental variables. Tracking the movements of fish relies on establishing links between environmental variables and otolith chemistry, with links commonly made using laboratory experiments that rear juvenile fish. However, laboratory experiments done on juvenile fish may not accurately reflect changes in wild fish, particularly adults. We tested the hypotheses that: (1) the relationship between ambient (water) and otolith chemistry is similar between laboratory-reared black bream (Acanthopagrus butcheri) and wild black bream; and (2) ontogeny does not influence otolith chemistry. Field-collected and laboratory-reared fish showed similar effects of ambient strontium : calcium (Sr : Ca) on otolith Sr : Ca concentrations. However, ambient and otolith barium : calcium concentrations (Ba : Ca) differed slightly between laboratory-reared and field-collected fish. Importantly, fish reared in stable environmental variables showed no influence of ontogeny on Sr : Ca or Ba : Ca concentrations. Natural distributions of ambient Sr : Ca showed no clear relationship to salinity, yet, ambient Ba : Ca was inversely related to salinity. The distribution of ambient Sr : Ca and Ba : Ca in estuaries inhabited by black bream, suggest that these elements can answer different questions regarding environmental histories of fish. Reconstructing salinity histories of black bream using otolith Ba : Ca concentrations seems plausible, if adequate knowledge of Ba : Ca gradients within estuaries is obtained.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

Cationic Amino Acid Transporter-1 (CAT-1) Promotes Fibroblast-Like Synoviocytes Proliferation and Cytokine Secretion by Taking Up L-Arginine in Rheumatoid Arthritis

2021 ◽  
Author(s):  
Ying Lu ◽  
Chongbo Hao ◽  
Shanshan Yu ◽  
Zuan Ma ◽  
Xuelian Fu ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Amino Acid ◽  
Synovial Fluid ◽  
Culture Conditions ◽  
Cytokine Secretion ◽  
Cationic Amino Acid Transporter ◽  
Cationic Amino Acid ◽  
The Relationship ◽  
Fibroblast Like Synoviocytes

Abstract Background: Abnormal proliferation of fibroblast-like synoviocytes (FLSs) in the synovial lining layer is the primary cause of synovial hyperplasia and joint destruction in rheumatoid arthritis (RA). Currently, the relationship between metabolic abnormalities and FLS proliferation is a new focus of investigation. However, little is known regarding the relationship between amino acid metabolism and RA. Methods: The concentrations of amino acids and cytokines in the synovial fluid of RA (n=9) and osteoarthritis (OA,n=9) were detected by LC-MS/MS and CBA assay, respectively. The mRNA and protein expression of CAT-1 were determined in FLSs isolated from RA and OA patients by real-time PCR and western blotting. MTT assay, cell cycle, apoptosis, invasion and cytokine secretion were determined in FLSs knocked down of CAT-1 using siRNA or treated with D-arginine under normoxic and hypoxic culture conditions. A mouse collagen-induced arthritis (CIA) model was applied to test the therapeutic potential of blocking the uptake of L-arginine in vivo.Results: L-arginine was upregulated in the synovial fluid of RA patients and was positively correlated with elevation of the cytokines IL-1β, IL-6 and IL-8. Further examination demonstrated that cationic amino acid transporter-1 (CAT-1) was the primary transporter for L-arginine and was overexpressed on RA FLSs compared to OA FLSs. Moreover, knockdown of CAT-1 using siRNA or inhibition of L-arginine uptake using D-arginine significantly suppressed L-arginine metabolism, cell proliferation, migration and cytokine secretion in RA FLSs under normoxic and hypoxic culture conditions in vitro but increased cell apoptosis in a dose-dependent manner. Meanwhile, in vivo assays revealed that an L-arginine-free diet or blocking the uptake of L-arginine using D-arginine suppressed arthritis progression in CIA mice. Conclusion: CAT-1 is upregulated and promotes FLS proliferation by taking up L-arginine, thereby promoting RA progression.

Self-Interested Giving: The Relationship Between Conditional Gifts, Charitable Donations, and Donor Self-Interestedness

2021 ◽  
Author(s):  
Matthew Chao ◽  
Geoffrey Fisher
Keyword(s):  
Decision Analysis ◽  
Experimental Evidence ◽  
Laboratory Experiments ◽  
Self Report ◽  
Negative Effects ◽  
Charitable Donations ◽  
Prosocial Motives ◽  
The Gift ◽  
Other Regarding ◽  
The Relationship

Nonprofits regularly use conditional “thank you” gifts to entice prospective donors to give, yet experimental evidence suggests that their effects are mixed in practice. This paper uses multiple laboratory experiments to test when and why thank you gifts vary in effectiveness. First, we demonstrate that although gifts often increase donations to charities that donors did not rate highly, many of the same gifts had no effects or negative effects for charities that prospective donors already liked. We replicate these findings in a second experiment that uses a different range of charity and gift options as well as different measures of participant perceptions of a charity. We also find that making gifts optional, as is common in fundraising campaigns, does not eliminate these negative gift effects. In additional experiments, we directly test for donor motives using self-report and priming experiments. We find that thank you gifts increase (decrease) the weight that donors place on self-interested (prosocial) motives, leading to changes in donation patterns. Altogether, our results suggest that practitioners may find gifts more useful when appealing to donors not already familiar with or favorably inclined to their charity, such as during donor acquisition campaigns. They may be less useful when appealing to recent donors or others who already favor the charity, in part because the gift may activate mindsets or norms that emphasize self-interested motives instead of more prosocial, other-regarding motives. This paper was accepted by Yan Chen, decision analysis.

scholarly journals Diagnosing the transition layer at extratropical latitudes using MLS O<sub>3</sub> and MOPITT CO analyses

2013 ◽  
Vol 13 (14) ◽  
pp. 7225-7240 ◽  
Author(s):  
J. Barré ◽  
L. El Amraoui ◽  
P. Ricaud ◽  
W. A. Lahoz ◽  
J.-L. Attié ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Transition Region ◽  
Transition Layer ◽  
Transport Model ◽  
Global Scale ◽  
British Isles ◽  
Chemistry Transport Model ◽  
Free Model ◽  
The Relationship

Abstract. The behavior of the extratropical transition layer (ExTL) is investigated using a chemistry transport model (CTM) and analyses derived from assimilation of MLS (Microwave Limb Sounder) O3 and MOPITT (Measurements Of Pollution In The Troposphere) CO data. We firstly focus on a stratosphere–troposphere exchange (STE) case study that occurred on 15 August 2007 over the British Isles (50° N, 10° W). We evaluate the effect of data assimilation on the O3–CO correlations. It is shown that data assimilation disrupts the relationship in the transition region. When MLS O3 is assimilated, CO and O3 values are not consistent between each other, leading to unphysical correlations at the STE location. When MLS O3 and MOPITT CO assimilated fields are taken into account in the diagnostics the relationship happens to be more physical. We then use O3–CO correlations to quantify the effect of data assimilation on the height and depth of the ExTL. When the free-model run O3 and CO fields are used in the diagnostics, the ExTL distribution is found 1.1 km above the thermal tropopause and is 2.6 km wide (2σ). MOPITT CO analyses only slightly sharpen (by −0.02 km) and lower (by −0.2 km) the ExTL distribution. MLS O3 analyses provide an expansion (by +0.9 km) of the ExTL distribution, suggesting a more intense O3 mixing. However, the MLS O3 analyses ExTL distribution shows a maximum close to the thermal tropopause and a mean location closer to the thermal tropopause (+0.45 km). When MLS O3 and MOPITT CO analyses are used together, the ExTL shows a mean location that is the closest to the thermal tropopause (+0.16 km). We also extend the study at the global scale on 15 August 2007 and for the month of August 2007. MOPITT CO analyses still show a narrower chemical transition between stratosphere and troposphere than the free-model run. MLS O3 analyses move the ExTL toward the troposphere and broaden it. When MLS O3 analyses and MOPITT CO analyses are used together, the ExTL matches the thermal tropopause poleward of 50°.

scholarly journals Rock art and the prehistoric landscape of Galicia: the results of field survey 1992–1994

1995 ◽  
Vol 61 ◽  
pp. 347-370 ◽  
Author(s):  
Richard Bradley ◽  
Felipe Criado Boado ◽  
Ramón Fábregas Valcarce
Keyword(s):  
Bronze Age ◽  
Field Survey ◽  
Rock Art ◽  
Outer Edge ◽  
Early Bronze Age ◽  
Copper Age ◽  
North West ◽  
Abrupt Changes ◽  
Ground Conditions ◽  
The Relationship

This paper discusses the relationship between the earlier prehistoric pattern of settlement in Atlantic Europe and the creation of rock art. It investigates the organisation of the Copper Age and Early Bronze Age landscape of north-west Spain using the evidence provided by the distribution, siting, and composition of rock carvings. It presents the results of field survey in three sample areas extending from the centre to the outer edge of their distribution. Although these drawings cannot be interpreted as illustrations of daily life, they may have helped to define rights to particular resources in an area which experienced abrupt changes of ground conditions over the course of the year.

scholarly journals Las políticas supranacionales de educación superior ante la «tercera misión» de la Universidad: el caso del aprendizaje-servicio

2020 ◽  
pp. 256
Author(s):  
Juan García-Gutiérrez ◽  
Carlos Corrales Gaitero
Keyword(s):  
Higher Education ◽  
Latin American ◽  
Global Scale ◽  
Third Mission ◽  
Social Commitment ◽  
Social Mission ◽  
The Social ◽  
American Citizenship ◽  
The University ◽  
The Relationship

The constant transformation that the institutions of higher education experiment and, particularly, the university assumes a re-consideration of their shapes, methodology, and missions, as well as the relationships established with society. Therefore, we shall consider that a “social mission” of the university or their “third mission” constitutes an umbrella that shelters a wide diversity of reflex conceptions, and at the same time, the relationship university – society. Additionally, take into consideration that this civic and social commitment in higher education should incorporate an integrator approach, involved with an idea of European or Latin-American citizenship, in any case, incorporated in the development of their supranational policies. Therefore, the objective of our work is double. On one side, to meet and analyze the notion of a “social mission” or “third mission” of the university and their conceptual network, to clarify the language and in which sense the different denominations are used, according to the different economical, sustainability or civic approaches to be adopted. Secondly, the treatment of these ideas will be addressed at the supranational policies of higher education both in Europe and Ibero America, according to what had been structured at the Higher Education European State and whether it has been promoted by the OEI. Also, it will be attended the way that this supranational policy aboard the civic and identity components, that linked to the social mission cooperate for the promotion of common citizenship. As a result of the analysis made we can affirm that the approach of the learning-service constitutes an emergent tendency on a global scale, appropriate to develop effectively the third mission or social mission of the university.

scholarly journals Evaluation of bacterial proliferation with a microfluidic-based device: Antibiochip

2019 ◽  
Author(s):  
Valentina Gallo ◽  
Alessia Ruiba ◽  
Massimo Zanin ◽  
Paolo Begnamino ◽  
Sabina Ledda ◽  
...  
Keyword(s):  
Laboratory Medicine ◽  
Culture Conditions ◽  
Inhibition Of Proliferation ◽  
Standard Methods ◽  
E Coli ◽  
Bacterial Proliferation ◽  
Microbial Cultures ◽  
Novel Approach ◽  
Microbial Strains ◽  
The Relationship

AbstractThe measurement of the proliferation (and the relevant inhibition of proliferation) of microbes is used in different settings, from industry to laboratory medicine. Thus, in this study, the capacity of the Antibiochip (ELTEK spa), a microfluidic-based device, to measure the amount of E. coli in certain culture conditions, was evaluated. An Antibiochip is composed of V-shaped microchannels, and the amount of microparticles (such as microbes) is measured by the surface of the pellet after centrifugation. In the present study, different geometries, volumes and times were analyzed. When the best conditions were identified, serial dilutions of microbial cultures were tested to validate the linearity of the results. Then, with the use of wild E. coli strains isolated from medical samples, the relationship between bacterial susceptibility to antibiotics (gentamicin, amikacin and ceftriaxone) measured by standard methods and that measured by the Antibiochip was evaluated. In this report, the good quality performances of the methods, their linearity and the capacity to identify susceptible microbial strains after 60 minutes of incubation are shown. These results represent a novel approach for ultrarapid antibiograms in clinics.

scholarly journals Analisis dan Perancangan Sistem Karcis Elektronik Pada Gerbang Masuk Busway Dengan Menggunakan RFID

2010 ◽  
Vol 1 (2) ◽  
pp. 942
Author(s):  
Suryadiputra Liawatimena
Keyword(s):  
Response Time ◽  
Data Security ◽  
System Performance ◽  
Research Laboratory ◽  
Laboratory Experiments ◽  
Field Survey ◽  
The Internet ◽  
Literature Study ◽  
Online Systems ◽  
Minimum System

The aim of this study is to use Radio Frequency technology to facilitate human activities, especially used in Busway entrances. In this research methodologies used include field survey to the BP Transjakarta; literature study by reading manuals, text books, journals, and articles on the Internet, and conduct laboratory experiments on the Bina Nusantara University Hardware Research Laboratory in designing and making the minimum system . Based on the results of an experiment and taking data on the minimum system, it can be concluded in general the performance of the system is running well, but the response time was not optimal. Some improvements to the system needed to improve system performance, such as raising response time, improved data security, and online systems. 

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