scholarly journals Ichthyofauna in an estuary of the Mataripe area, Todos os Santos Bay, Bahia, Brazil

2011 ◽  
Vol 59 (1) ◽  
pp. 75-95 ◽  
Author(s):  
June Ferraz Dias ◽  
Aline Mariane Gonçalves ◽  
Wellington Silva Fernandez ◽  
Helcy Lylian Nogueira Silbiger ◽  
Carla Bertolucci Fiadi ◽  
...  
Keyword(s):  
Great Majority ◽  
Population Level ◽  
Oil Refinery ◽  
Fishing Gear ◽  
Total Biomass ◽  
Study Region ◽  
Structure And Dynamics ◽  
Growth Area ◽  
Elasmobranch Species ◽  
Estuarine Region

The community structure and dynamics as well as some biological parameters of selected species of the ichthyofauna of the Mataripe estuarine region affected by the Landulfo Alves Oil Refinery (RLAM) were analyzed. Twenty stations were sampled with a gillnet in five different periods: August and December 2003, March and July/August 2004 and January 2005. Thirty-five actinopterygian species and one elasmobranch species were recorded, Oligoplites saurus, Diapterus rhombeus, Lutjanus synagris and Scomberomorus brasiliensis among them, on all the campaigns. A total of 1368 specimens, weighing 36.10 kg, were caught. The ichthyofauna total biomass was greater, in weight, on the eastern side of the study region, especially at the stations close to the shoals/reefs and the rocky bottom. A similar pattern was also observed for the diversity values. In general, low evenness and diversity were observed in the area studied, possibly as a result of the fishing gear used. D. rhombeus juveniles dominated in all but one of the samplings (July 2004), in which latter Cyclichthys spinosus was dominant. Carangids and species associated with consolidated bottoms were observed, although in small numbers, throughout the study period. In spite of the limitations imposed by the gear used for sampling, the estuarine area influenced by the RLAM was seen to play a role as a growth area for the great majority of species, especially the mojarra (D. rhombeus), but it offers no fishing potential due to the prevalence of young and small individuals. Evidence of imminent spawning was recorded for Pomadasys corvinaeformis in August 2003, and recent spawning in March 2004 for Oligoplites saurus. Further, mature individuals occurred in insufficient numbers to permit population level evaluation.

scholarly journals Fatal diseases and parasitoids: from competition to facilitation in a shared host

2016 ◽  
Vol 283 (1828) ◽  
pp. 20160154 ◽  
Author(s):  
Ann E. Hajek ◽  
Saskya van Nouhuys
Keyword(s):  
Fungal Pathogen ◽  
Parasite Species ◽  
Host Density ◽  
Population Level ◽  
Parasite Community ◽  
Parasitoid Species ◽  
Community Interactions ◽  
Structure And Dynamics ◽  
Fungal Entomopathogen ◽  
Emergent Pathogen

Diverse parasite taxa share hosts both at the population level and within individual hosts, and their interactions, ranging from competitive exclusion to facilitation, can drive community structure and dynamics. Emergent pathogens have the potential to greatly alter community interactions. We found that an emergent fungal entomopathogen dominated pre-existing lethal parasites in populations of the forest defoliating gypsy moth, Lymantria dispar . The parasite community was composed of the fungus and four parasitoid species that only develop successfully after they kill the host, and a virus that produces viable propagules before the host has died. A low-density site was sampled over 17 years and compared with 66 sites across a range of host densities, including outbreaks. The emergent fungal pathogen and competing parasitoids rarely co-infected host individuals because each taxa must kill its host. The virus was not present at low host densities, but successfully co-infected with all other parasite species. In fact, there was facilitation between the virus and one parasitoid species hosting a polydnavirus. This newly formed parasite community, altered by an emergent pathogen, is shaped both by parasite response to host density and relative abilities of parasites to co-inhabit the same host individuals.

scholarly journals Cetaceans and Marine Debris: The Great Unknown

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Mark Peter Simmonds
Keyword(s):  
At Risk ◽  
Population Level ◽  
Marine Debris ◽  
Fishing Gear ◽  
Important Habitat ◽  
Digestive Processes

Plastics and other marine debris have been found in the gastrointestinal tracts of cetaceans, including instances where large quantities of material have been found that are likely to cause impairment to digestive processes and other examples, where other morbidity and even death have resulted. In some instances, debris may have been ingested as a result of the stranding process and, in others, it may have been ingested when feeding. Those species that are suction or “ram” feeders may be most at risk. There is also evidence of entanglement of cetaceans in marine debris. However, it is usually difficult to distinguish entanglement in active fishing gear from that in lost or discarded gear. The overall significance of the threat from ingested plastics and other debris remains unclear for any population or species of cetaceans, although there are concerns for some taxa, including at the population level, and marine debris in the oceans continues to grow. Further research including the compilation of unpublished material and the investigation of important habitat areas is strongly recommended.

scholarly journals Fodder and Grain Yield in Native Maize (Zea mays L.)

2021 ◽  
Vol 13 (12) ◽  
Author(s):  
J.Alberto.S Escalante-Estrada ◽  
M.T. Rodríguez-González ◽  
Y. I. Escalante-Estrada
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Plant Height ◽  
Design Methodology ◽  
Zea Mays L ◽  
Total Biomass ◽  
Study Region ◽  
Maize Cultivars ◽  
Maize Genotypes ◽  
The Relationship

Objective: To quantify the grain yield, biomass, crop stubble, and leaf:stalk index in seven varieties of maize (Zea mays L.), as well as the relationship between biomass, stubble, and plant height. Design/Methodology/Approach: The process consisted in planting seven genotypes of native maize (Zea mays L.). The experimental design comprised randomized blocks with four repetitions. The plant’s height, total biomass, its accumulation in stalk, leaf, husk, cob, grain, and stubble (biomass of stalk?leaf?husk?cob) were evaluated. A varianceanalysis, the Tukey means comparison test, and a regression analysis were applied. Results: Significant differences were found between the native maize genotypes. Notable cases were the Ixtenco Yellow, followed in terms of biomass and stubble by the Texcoco White-Wide, then the Ixtenco White and Red. The plant height determined biomass in 67% and stubble in 77%. Study Limitations/Implications: The tendencies found could vary depending on the native cultivars studied and their management. Findings/Conclusions: In the study region, there are differences between native maize cultivars for the agronomic characteristics evaluated. With respect to the yield of grain, biomass, and stubble, the Ixtenco Yellow cultivar was outstanding, followed by the Texcoco White-Wide, and Ixtenco White and Red. The plant height determined biomass in 67%, and stubble quantity in 77%.

The Colorado River Delta and California’s Central Valley are critical regions for many migrating North American landbirds

The Condor ◽  
2021 ◽  
Vol 123 (1) ◽  
Author(s):  
William V DeLuca ◽  
Tim Meehan ◽  
Nat Seavy ◽  
Andrea Jones ◽  
Jennifer Pitt ◽  
...  
Keyword(s):  
Colorado River ◽  
Central Valley ◽  
Population Level ◽  
Breeding Population ◽  
River Delta ◽  
Colorado River Delta ◽  
Study Region ◽  
Continental Population ◽  
California's Central Valley ◽  
California’S Central Valley

Abstract Migration is an important component of some species full annual cycle. California’s Central Valley and the Colorado River Delta provide important riparian and wetland habitats for migrating waterbirds in the arid west of North America, but little is known about whether these locations are important at the population level to migrating landbirds. We used eBird Status and Trends abundance data to quantify the importance of the Central Valley and Colorado River Delta to landbirds by estimating the proportion of the breeding population of 112 species that use each site during migration. We found that ~17 million landbirds use the Colorado River Delta in the spring and ~14 million in the fall. Across 4 study regions in the Central Valley, up to ~65 million landbirds migrate through in the spring and up to ~48 million in the fall. In the spring and fall, respectively, up to 37 and up to 30 species had at least 1% of their continental population migrate through the study regions. We also quantified the spatial concentration of each species across latitudinal transects to determine the extent to which study regions were acting as migratory bottlenecks. Landbird abundances were spatially concentrated in study regions 29.4% of all migration weeks, indicating that each study region acts as a migratory bottleneck. This application of eBird data is a powerful approach to quantifying the importance of sites to migrating birds. Our results provide evidence of population-level importance of the Central Valley and Colorado River Delta for many migratory landbirds.

Abstract 248: Geographic Variability in Population Outcomes for Out-of-Hospital Cardiac Arrest

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Alexis Zebrowski ◽  
Douglas J Wiebe ◽  
David Karp ◽  
David G Buckler ◽  
Manqing Liu ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Population Level ◽  
Population Based ◽  
Regional Variability ◽  
Study Region ◽  
Discharge Rates ◽  
Novel Approach ◽  
Regional Cluster ◽  
Utilization Patterns ◽  
Zip Code

Introduction: Significant work has described patient and hospital level variability in survival after out-of-cardiac arrest (OHCA). OHCA requires a population based systems response in order to optimize regional outcomes, but no regional or systems level incentives exist. We used population based claims data to empirically describe geographic utilization patterns for OHCA and then benchmarked and compared population level outcomes. Methods: OHCA cases were identified from the Healthcare Cost and Utilization Project’s State Emergency Department Databases and State Inpatient Databases for 2011 in 3 states, (NY, NE, FL). Patient cohorts were identified using an ICD-9-CM code of 427.5 for the principal (outpatient) or admitting (inpatient) diagnosis. Exclusion criteria included living outside of the study area and no valid residential ZIP code. Geographic clusters were identified based on hospital utilization patterns at the ZIP code tabulation area level using hierarchical clustering. Boundary zip codes could belong to more than one regional cluster. Adjusted survival was calculated using multi-level logistic regression controlling for demographic, hospital, and community-level variables for each cluster. Results: In 2011, there were 17,086 OHCA treated in the study region, with a mean survival rate to admission of 18.2%; 5.1% to discharge. Hospitals and ZIP codes were grouped into 26 regions (OHCA cases per region: range 7-4,698). Regional unadjusted survival to admission ranged from 0-26.6% and adjusted from 2.8-25.0%. Crude survival to discharge rates ranged from 0-12.8%, and adjusted rates ranged from 1.7-7.6% (Figure 1). Conclusions: This novel approach demonstrates a method by which to measure regional variability in OHCA survival. Because the region is determined empirically based on a utilization based attribution method, population based incentives (or penalties) could be created by payers.

scholarly journals Degenerate PCR Primers to Reveal the Diversity of Giant Viruses in Coastal Waters

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 496 ◽  
Author(s):  
Yanze Li ◽  
Pascal Hingamp ◽  
Hiroyasu Watai ◽  
Hisashi Endo ◽  
Takashi Yoshida ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Population Level ◽  
Pcr Primers ◽  
Natural Environments ◽  
Specific Primers ◽  
Degenerate Pcr ◽  
Operational Taxonomic Units ◽  
Structure And Dynamics ◽  
Order Of Magnitude ◽  
Giant Viruses

“Megaviridae” is a proposed family of giant viruses infecting unicellular eukaryotes. These viruses are ubiquitous in the sea and have impact on marine microbial community structure and dynamics through their lytic infection cycle. However, their diversity and biogeography have been poorly characterized due to the scarce detection of Megaviridae sequences in metagenomes, as well as the limitation of reference sequences used to design specific primers for this viral group. Here, we propose a set of 82 degenerated primers (referred to as MEGAPRIMER), targeting DNA polymerase genes (polBs) of Megaviridae. MEGAPRIMER was designed based on 921 Megaviridae polBs from sequenced genomes and metagenomes. By applying this primer set to environmental DNA meta-barcoding of a coastal seawater sample, we report 5595 non-singleton operational taxonomic units (OTUs) of Megaviridae at 97% nucleotide sequence identity. The majority of the OTUs were found to form diverse clades, which were phylogenetically distantly phylogenetically related to known viruses such as Mimivirus. The Megaviridae OTUs detected in this study outnumber the giant virus OTUs identified in previous individual studies by more than an order of magnitude. Hence, MEGAPRIMER represents a useful tool to study the diversity of Megaviridae at the population level in natural environments.

scholarly journals Can microcystins affect zooplankton structure community in tropical eutrophic reservoirs?

2016 ◽  
Vol 76 (2) ◽  
pp. 450-460 ◽  
Author(s):  
T. A. S. V. Paes ◽  
I. A. S. Costa ◽  
A. P. C. Silva ◽  
E. M. Eskinazi-Sant’Anna
Keyword(s):  
Zooplankton Community ◽  
Population Level ◽  
Temporal Variations ◽  
Zooplankton Biomass ◽  
Total Biomass ◽  
Control Mechanisms ◽  
Calanoid Copepods ◽  
Negative Effects ◽  
Eutrophic Reservoirs ◽  
Allelopathic Compounds

Abstract The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcystins in water proved to be correlated with the cyanobacterial biovolume, indicating the contributions from colonial forms such as Microcystis in the production of cyanotoxins. At the community level, the total biomass of zooplankton was not correlated with the concentration of microcystin (r2 = 0.00; P > 0.001), but in a population-level analysis, the biomass of rotifers and cladocerans showed a weak positive correlation. Cyclopoid copepods, which are considered to be relatively inefficient in ingesting cyanobacteria, were negatively correlated (r2 = – 0.01; P > 0.01) with the concentration of cyanotoxins. Surprisingly, the biomass of calanoid copepods was positively correlated with the microcystin concentration (r2 = 0.44; P > 0.001). The results indicate that allelopathic control mechanisms (negative effects of microcystin on zooplankton biomass) do not seem to substantially affect the composition of mesozooplankton, which showed a constant and high biomass compared to the microzooplankton (rotifers). These results may be important to better understand the trophic interactions between zooplankton and cyanobacteria and the potential effects of allelopathic compounds on zooplankton.

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Spiny Dogfish ◽  
Total Biomass ◽  
Trawl Survey ◽  
Shark Species ◽  
Depth Range ◽  
The European Union ◽  
Northern Adriatic Sea ◽  
Western Basin ◽  
Elasmobranch Species ◽  
Elasmobranch Fishes

Abstract.—Data on two shark species, collected in the frame of the European Union program Mediterranean International Trawl Survey Program, are analyzed and reported. Indices of summer abundance per standardized area (per km2) in weight and number are available for both species since 1994 along the European Mediterranean coasts (from the Alboran to the Aegean seas). The studied area, with depths ranging from 10 to 800 m, was divided into five depth strata. Data of 10,000 hauls were analyzed and 44 elasmobranch species identified. The estimated comprehensive standing biomass of elasmobranch fishes within the explored area was 55,000 mt (mt); spiny dogfish <em>Squalus acanthias </em>was one of the most abundant species with an estimated biomass of 6,700 mt, while longnose spiny dogfish <em>S. blainvillei</em>, with about 1,500 mt, represents only 3% of the total biomass. The mean density of spiny dogfish was significantly different between the Mediterranean eastern basin (22.7 kg/km2) and western basin (only 0.8 kg/km2). On the contrary, longnose spiny dogfish shows higher density in the western basin (6.6 kg/km2) than in the eastern one (1.7 kg/km2). However, the spatial distribution of both species is fairly confined; spiny dogfish was caught in only 5% of the tows and longnose spiny dogfish in 3%. Even if the depth range of presence for both species spreads from less than 50 m to more than 700 m, the abundance indexes suggest a major presence in the coastal areas for spiny dogfish. This statement is based primarily on the high densities of the mentioned species in shallow waters of the northern Adriatic Sea; elsewhere the main concentrations are always positioned in the 200–500 m depth range.

scholarly journals On the Analysis of Intrahost and Interhost Viral Populations: Human Cytomegalovirus as a Case Study of Pitfalls and Expectations

2016 ◽  
Vol 91 (5) ◽  
Author(s):  
Nicholas Renzette ◽  
Susanne P. Pfeifer ◽  
Sebastian Matuszewski ◽  
Timothy F. Kowalik ◽  
Jeffrey D. Jensen
Keyword(s):  
Human Cytomegalovirus ◽  
Population Genetic ◽  
Great Majority ◽  
Population Level ◽  
Genomic Variation ◽  
Current View ◽  
Data Sets ◽  
Standard Population ◽  
Major Shift

ABSTRACT Intrahost and interhost assessments of viral diversity are often treated as measures of separate and distinct evolutionary processes, with numerous investigations reporting seemingly incompatible results between the two. For example, in human cytomegalovirus, the nucleotide diversity estimates are 10-fold higher for interhost data, while the number of segregating (i.e., polymorphic) sites is 6-fold lower. These results have been interpreted as demonstrating that sampled intrahost variants are strongly deleterious. In reality, however, these observations are fully consistent with standard population genetic expectations. Here, we analyze published intra- and interhost data sets within this framework, utilizing statistical inference tools to quantify the fitness effects of segregating mutations. Further, we utilize population level simulations to clarify expectations under common evolutionary models. Contrary to common claims in the literature, these results suggest that most observed polymorphisms are likely nearly neutral with regard to fitness and that standard population genetic models in fact well predict observed levels of both intra- and interhost variability. IMPORTANCE With the increasing number of evolutionary virology studies examining both intrahost and interhost patterns of genomic variation, a number of seemingly incompatible results have emerged, revolving around the far greater level of observed intrahost than interhost variation. This has led many authors to suggest that the great majority of sampled within-host polymorphisms are strongly deleterious. Here, we demonstrate that there is in fact no incompatibility of these results and, indeed, that the vast majority of sampled within-host variation is likely neutral. These results thus represent a major shift in the current view of observed viral variation.

Results of the Royal Society Indian Ocean Deep Slope Fishing Expedition, 1969

1970 ◽  
Vol 175 (1041) ◽  
pp. 367-404 ◽  
Keyword(s):  
Indian Ocean ◽  
Royal Society ◽  
Western Indian Ocean ◽  
Individual Species ◽  
Fishing Gear ◽  
Total Catch ◽  
Sea Floor ◽  
Elasmobranch Species ◽  
Geographical Position ◽  
The Individual

During a 6-week Royal Society Expedition in the western Indian Ocean 638 fishes were caught on drop lines worked chiefly at night at depths between 100 and 1000 m. Many of the species caught were rare or unrecorded from the area. The primary aim of the Expedition, to find specimens of the coelacanth Latimeria and thereby extend its known range, was not fulfilled. One teleost, the lutianid Etelis marshi , and a squaloid shark, Centrophorus sp., were particularly common, accounting for 60 % of the total catch; the remainder comprised 24 teleost and 11 elasmobranch species. Details are given of the itinerary, the fishing gear, fishing methods and the individual species caught, together with a brief discussion on the effect of depth, height of hooks above the sea floor and geographical position on the composition of the catches.

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