scholarly journals Enhanced trace element concentrations in tissues of the clam Ruditapes decussatus transplanted to areas influenced by human activities (Ria Formosa, Portugal)

2017 ◽  
Vol 81 (2) ◽  
pp. 229 ◽  
Author(s):  
Maria João Botelho ◽  
Sara T. Costa ◽  
Domitília Matias ◽  
Florbela Soares ◽  
Sandra Joaquim ◽  
...  
Keyword(s):  
Digestive Gland ◽  
Human Activities ◽  
Fish Farming ◽  
Condition Index ◽  
Small City ◽  
Ruditapes Decussatus ◽  
Ria Formosa ◽  
Minor Influence ◽  
A Minor ◽  
A Site

To examine the extent to which human activities near the Ria Formosa coastal lagoon influence the accumulation of trace elements (TE) in Ruditapes decussatus, individuals were transplanted from a natural bank located in the lower lagoon to three sites located in clam growth grounds under the influence of a small city (Faro), a fish farming centre (Olhão) and a site near the lagoon inlet (Lavajo). Concentrations were determined in substrate of the clam grounds and in the digestive gland, gills, mantle plus siphons, and remaining tissues of clams in four periods of the year. These measurements were accomplished with the monthly survey of the gametogenic stages, condition index, proteins, glycogen, total lipids, pH and osmolarity of hemolymph. Arsenic, Cu, Mn, V, Cr and Pb were preferentially linked to the digestive gland, while Cd was linked to the gills. TE concentrations in the digestive gland and remaining tissues were higher in winter, most likely reflecting additional inputs associated with rain. The lack of disruptions in biological parameters and the prolonged period of spawning and gonad recovery in clams suggest that the current TE availability in the lagoon has a minor influence on the reproductive cycle and hence on clam production.

scholarly journals Population dynamics and secondary production of Donax trunculus (Mollusca, Bivalvia) in the Gulf of Annaba (Northeast Algeria)

2016 ◽  
Vol 17 (3) ◽  
pp. 738 ◽  
Author(s):  
I. HAFSAOUI ◽  
B. DRAREDJA ◽  
R. LASOTA ◽  
S. COMO ◽  
P. MAGNI
Keyword(s):  
Population Dynamics ◽  
Secondary Production ◽  
Condition Index ◽  
Reproductive Period ◽  
Donax Trunculus ◽  
Accumulation Of Pollutants ◽  
One Year ◽  
June July ◽  
A Minor ◽  
A Site

The population dynamics and secondary production of the wedge clam Donax trunculus were studied in the Gulf of Annaba (Northeast Algeria) monthly for one year at a site close to the Annaba port and the Seybouse river, affected by industrial and agricultural pollution (Sidi Salem), and at a site more distant from major pollution sources, but exploited by fishery (Echatt). The number of individuals (N) was lower at Sidi Salem (36–148 ind m-2) than at Echatt (63–272 ind m-2) in most sampling dates, while the biomass was more variable from one date to another, with no consistent pattern of differences between sites. The condition index (CI), although slightly higher at Sidi Salem than at Echatt, showed at both sites a major increase in March/April, June/July and October, reflecting two main periods of gonads development and increase in the level of stored reserves at the end of the reproductive period. Consistently, the recruitment of D. trunculus ran from April to October with a major peak of abundance in spring and a minor one in early fall. The maximum age of D. trunculus was 3 years and the growth rate was highest in the first year. Annual somatic production (P) was lower at Sidi Salem (0.773 g AFDM m-2 yr-1) than at Echatt (1.262 g AFDM m-2 yr-1), possibly reflecting a lower mean annual biomass at Sidi Salem (1.642 AFDM m-2) than at Echatt (3.046 AFDM m-2), while the annual P/B ratio was similar between the two sites (i.e. 0.471 and 0.414 yr-1, respectively). Lower N and P at Sidi Salem compared to Echatt are consistent with the proximity of Sidi Salem to the industrial port of Annaba and low hydrodynamic conditions which may favor the accumulation of pollutants, such as hydrocarbons. On the other hand, moderate secondary production of D. trunculus at Echatt compared to other Mediterranean sites may be due to excessive harvesting. We suggest that the low secondary production described in this study should be taken into account for the development of sustainable strategies of clam exploitation in the Gulf of Annaba. In particular, effort should be made to reduce land-based pollution and to regulate the collection of D. trunculus according to the life cycle and production potential of this species.

Structure-activity relations and β-lactamase resistance

1980 ◽  
Vol 289 (1036) ◽  
pp. 197-205 ◽  
Keyword(s):  
Broad Spectrum ◽  
Product Inhibition ◽  
Sulphur Atom ◽  
Chemical Modifications ◽  
Gram Negative ◽  
Structure Activity ◽  
Broad Spectrum Resistance ◽  
Structure Activity Relations ◽  
Minor Influence ◽  
A Minor

β-Lactam antibiotics resistant to β-lactamase degradation can be produced by many chemical modifications, but often at the expense of antibacterial activity. Substitution onto several positions in the molecule produces different and often selective resistance; for instance, heavily sterically hindered acyl groups give staphylococcal P-lactamase resistance to penicillins, and resistance to some enzymes from Gram-negative pathogens to both penicillins and cephalosporins. 6-α- or 7-α-substituents respectively confer a broad spectrum of resistance (e.g. cefoxitin), but changes at positions 2 or 3 have only a minor influence on enzyme susceptibility. Changes in the ring condensed with the β-lactam, such as changing ceph-3-em to ceph-2-em may greatly enhance stability. Small improvements can occur when the nuclear sulphur atom is oxidized, but a much better effect is obtained when it is replaced by another atom such as oxygen, as in clavulanic acid. This compound appears to have broad spectrum resistance which is actually due to susceptibility and subsequent product inhibition.

Lubrication Properties of Aqueous Solutions with Polyethoxylated Ether (PEOE) Added

2011 ◽  
Vol 239-242 ◽  
pp. 1359-1363
Author(s):  
Chao Hui Zhang ◽  
Si Si Liu ◽  
Yue Tao Sun ◽  
Jun Ming Liu
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Metal Working ◽  
Functional Additives ◽  
Film Forming ◽  
Minor Influence ◽  
Forming Characteristics ◽  
Aqueous Surfactants ◽  
A Minor ◽  
Lubrication Properties

Aqueous solutions have found broad usages as lubricants, in conjunction with other possible utilizations, such as in metal working and other industries. Due to the inferior lubricity, functional additives are needed to improve their tribological performances among which aqueous surfactants are exclusively included. The film forming property of aqueous solution with polyethoxylated ether added (PEOE) is measured, taking consideration of the influences of the temperature and the concentration. The addition of PEOEs into aqueous solutions will largely increase the film forming capacity. But the concentration has only a minor influence on the lubrication property of the aqueous solutions with PEOEs. The cloud point will strongly alter the film forming characteristics.

scholarly journals Influence of Different Commercial Yeasts on Volatile Fraction of Sparkling Wines

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 247
Author(s):  
Valeriu V. Cotea ◽  
Mihai Cristian Focea ◽  
Camelia Elena Luchian ◽  
Lucia Cintia Colibaba ◽  
Elena Cristina Scutarașu ◽  
...  
Keyword(s):  
International Organization ◽  
Volatile Fraction ◽  
Chemical Parameters ◽  
Physical Chemical ◽  
Organoleptic Characteristics ◽  
Mass Spectrometry Technique ◽  
Minor Influence ◽  
Spectrometry Technique ◽  
A Minor ◽  
Aging Stage

The occurrence of aroma constituents in sparkling wines, with direct impact on their organoleptic characteristics, is affected by several factors, for example the base-wine particularities, grapes cultivar conditions, inoculated yeasts, the aging stage, and wine-making practices. This study evaluated the influence of different four commercial yeasts (IOC FIZZ™, IOC DIVINE™, LEVULIA CRISTAL™, and IOC 18-2007™) on the volatile composition of experimental sparkling wines. For this, five sparkling wines variants from the Muscat Ottonel grape variety were obtained. The base-wine was obtained through reverse osmosis and had a predetermined alcoholic concentration (10.5% vol.). In order to fulfill the proposed purpose, the experimental sparkling wines were characterized by the physical–chemical parameters (according to International Organization of Vine and Wine methods of analysis), volatile fraction (using gas-chromatography coupled with mass spectrometry technique), and sensory descriptors. Data showed a key impact on the concentration of the volatile constituents (p < 0.05), depending on the type of inoculated yeast for the second fermentation. Regarding the sensory analysis, important differences can be observed due to the type of inoculated yeast. Only a minor influence on the physical–chemical parameters was registered.

scholarly journals Phytoplankton thermal responses adapt in the absence of hard thermodynamic constraints

2018 ◽  
Author(s):  
Dimitrios - Georgios Kontopoulos ◽  
Erik van Sebille ◽  
Michael Lange ◽  
Gabriel Yvon-Durocher ◽  
Timothy G. Barraclough ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Thermal Sensitivity ◽  
Meta Analysis ◽  
Habitat Type ◽  
Performance Curve ◽  
Thermal Environments ◽  
Thermal Performance Curve ◽  
Performance Curves ◽  
Minor Influence ◽  
A Minor

AbstractTo better predict how populations and communities respond to climatic temperature variation, it is necessary to understand how the shape of the response of fitness-related traits to temperature evolves (the thermal performance curve). Currently, there is disagreement about the extent to which the evolution of thermal performance curves is constrained. One school of thought has argued for the prevalence of thermodynamic constraints through enzyme kinetics, whereas another argues that adaptation can—at least partly—overcome such constraints. To shed further light on this debate, we perform a phylogenetic meta-analysis of the thermal performance curves of growth rate of phytoplankton—a globally important functional group—, controlling for environmental effects (habitat type and thermal regime). We find that thermodynamic constraints have a minor influence on the shape of the curve. In particular, we detect a very weak increase of maximum performance with the temperature at which the curve peaks, suggesting a weak “hotter-is-better” constraint. Also, instead of a constant thermal sensitivity of growth across species, as might be expected from strong constraints, we find that all aspects of the thermal performance curve evolve along the phylogeny. Our results suggest that phytoplankton thermal performance curves adapt to thermal environments largely in the absence of hard thermodynamic constraints.

scholarly journals Study the effect of low pH on Ruditapes decussatus (Mollusca: Bivalvia)

2021 ◽  
Author(s):  
Anam Tsear
Keyword(s):  
Economic Value ◽  
Ammonia Excretion ◽  
Condition Index ◽  
Sandy Beaches ◽  
Ruditapes Decussatus ◽  
Average Value ◽  
Mediterranean Lagoons ◽  
Small Decline ◽  
Algal Feed ◽  
Response Testing

The grooved carpet shell clam (Ruditapes decussatus) is one of the most economically essential mollusks in Mediterranean lagoons and sandy beaches, with fisheries and aquaculture both contributing to its abundance. The goal of this research is to see how varying amounts of acidity affect this calcifying organism. 420 ppm (ambient control), 550 ppm, 750 ppm, and 1050 ppm were used to incubate juvenile clams in CO2  enriched saltwater. With increasing pCO2 , the biological parameters evaluated revealed a small decline. Differences, however, were not substantial. In terms of overall weight, the reduction was greatest at 550 and 1050 ppm. Furthermore, clams kept at 550 parts per million had the lowest condition index and the greatest mortality rate of 8%. Both the 550 ppm and the control 420 ppm groups demonstrated an increase in metabolic rate and ammonia excretion in the physiological response testing. With increasing acidification, the algal feed clearance rate declined, with the highest average value in the control (420 ppm) group and the lowest average value in the extremely high pCO2 (1050 ppm) group. Ocean acidification may put further strain on R. decussatus' health and economic value by the end of the century

scholarly journals Benthic foraminifera as ecological indicators in the Tunda Island Waters, Serang District, Banten Province, Indonesia

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
ISNI NURRUHWATI ◽  
FACHRI ARDIANSYAH ◽  
YUNIARTI ◽  
LINTANG PERMATA SARI YULIADI ◽  
Ruhyat Partasasmita
Keyword(s):  
Water Quality ◽  
Coral Reefs ◽  
Benthic Foraminifera ◽  
Human Activities ◽  
Ecological Factors ◽  
Ecological Indicators ◽  
Coastal Development ◽  
Mangrove Forests ◽  
Benthic Foraminifers ◽  
A Site

Abstract. Nurruhwati I, Ardiansyah F, Yuniarti, Yuliadi LPS, Partasasmita R. 2020. Benthic foraminifera as ecological indicators in the Tunda Island Waters Serang District, Banten Province, Indonesia. Biodiversitas 21: 3142-3148. Coral reef communities all across Southeast Asia are experiencing intense pressures from extensive tourism and massive coastal development. A prediction regarding coral reefs’ capacity to recover is a necessity since it is constantly exposed to damaging events such as mass bleaching and increased erosion. Tunda Island (which is highly rich in biodiversity and include coral reefs, mangrove forests, seagrass, and algae meadows) was sampled at 10 different sites in August 2019. Coral reefs are highly influenced by ecological factors such as temperature variability, salinity, DO, and pH. The assessments were conducted using the FORAM Index (FI) to accurately predict the capacity of coral reefs to recover based on relative abundances of symbiont-bearing larger benthic foraminifera in reef sediments. The FI values ranged from 3.7 to 7.9 with a median of 4.7 and the average of 5 indicates that the water quality should support the recovery of reefs by reef-building corals and symbiont-bearing larger benthic foraminifers. The lowest FI value sampled was recorded from a site with extensive human activities (FI=3.4), while the highest one was recorded from a site with minimal to none human activities (FI=7.9), which indicates that the deterioration of water quality is caused by wastes from tourism activities near the coastal area.

scholarly journals The Lithics and Fauna from Heidenschmiede, a Middle Paleolithic Rockshelter in Heidenheim an der Brenz (Swabian Jura)

2021 ◽  
Author(s):  
Susanne Münzel ◽  
Berrin Çep
Keyword(s):  
Human Activities ◽  
Minor Role ◽  
Middle Paleolithic ◽  
Archaeological Remains ◽  
Faunal Remains ◽  
Carnivore Species ◽  
Steppe Ecosystem ◽  
A Minor ◽  
Game Animals

Heidenschmiede is a Middle Paleolithic rockshelter located in Heidenheim an der Brenz. The site was excavated in 1930 by Eduard Peters, but the archaeological remains were never completely analyzed. The lithic and faunal remains have recently been re-analyzed by the authors. The general features of the lithics are indicative of a Middle Paleolithic technology that includes a non-Levallois blade technology. The faunal remains reflect a Mammoth Steppe ecosystem and include mammoth, horse, woolly rhino and reindeer. Carnivore species play a minor role, although some carnivore gnawing is present. The archeological assemblage of this rockshelter demonstrates clear evidence of human activities, such as flint knapping, butchering of game animals, maintaining of hearths (burnt bones) and preparation of organic tools (retouchers).

Meiofauna constitute a considerable portion of invertebrate drift among moss-rich patches within a karst hydrosystem

Biologia ◽  
2014 ◽  
Vol 69 (3) ◽  
Author(s):  
Mirela Perić ◽  
Tvrtko Dražina ◽  
Maria Špoljar ◽  
Ines Radanović ◽  
Biserka Primc ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Spatial Scale ◽  
Early Summer ◽  
Small Scale ◽  
Invertebrate Drift ◽  
Flow Conditions ◽  
Small Spatial Scale ◽  
Minor Influence ◽  
Drift Density ◽  
A Minor

AbstractAiming to establish the most frequent invertebrate taxa in drift at the small spatial scale within a moss-rich karst tufa-precipitating hydrosystem, we sampled drift among microhabitats differing in substratum type and flow conditions along a tufa barrier-cascading lotic reach. Additionally, we addressed the question of the contribution and the potential significance of meiofauna within the overall invertebrate drift at the small spatial scale. During the study period, a total of 60 invertebrate taxa were recorded in the drift. Six of these taxa belonged to the annelid/arthropod meiofauna and they represented 35% of total drift density. Macroinvertebrates found in drift were represented mainly by larval insects. The composition of the most abundant taxa in total drift was as follows: Alona spp. (Cladocera 26.7%), Riolus spp. (Coleoptera: Elmidae 13.2%), Simulium spp. (Diptera: Simuliidae 12.2%), Enchytraeidae (Oligochaeta 10.4%), Hydrachnidia (6.3%), Orthocladinae (Diptera: Chironomidae 3.9%) and Naididae (Oligochaeta 3.6%). Faunal drift densities and amounts of transported particulate matter (PM) were highest at the fast-flowing sites located at the barriers and lowest at the slow-flowing sites within pools. Similarly to the seasonal amounts of transported PM, faunal drift was lowest in winter, and peaked in autumn and in late spring/early summer. Correlation between flow velocity and PM-faunal drift densities suggested a significant effect of the dislodged PM, though a minor influence of discharge and flow velocity on faunal drift. We suggest that the small-scale habitat heterogeneity and the respective feeding and refugial strategies of the fauna, as well as faunal passive dislodgement initiated by the shear forces of the flow were the most important drivers of observed drift patterns.

scholarly journals Perspective determines the production and interpretation of pointing gestures

2020 ◽  
Author(s):  
Oliver Herbort ◽  
Lisa-Marie Krause ◽  
Wilfried Kunde
Keyword(s):  
Virtual Reality ◽  
Virtual Reality Environment ◽  
Observer Perspective ◽  
Minor Influence ◽  
Pointing Gestures ◽  
A Minor ◽  
The Relationship

Abstract Pointing is a ubiquitous means of communication. Nevertheless, observers systematically misinterpret the location indicated by pointers. We examined whether these misunderstandings result from the typically different viewpoints of pointers and observers. Participants either pointed themselves or interpreted points while assuming the pointer’s or a typical observer perspective in a virtual reality environment. The perspective had a strong effect on the relationship between pointing gestures and referents, whereas the task had only a minor influence. This suggests that misunderstandings between pointers and observers primarily result from their typically different viewpoints.

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