scholarly journals Occurrence of Cymbasoma longispinosum Bourne, 1890 (Copepoda: Monstrilloida) in the Curuçá River estuary (Amazon Littoral)

2010 ◽  
Vol 82 (3) ◽  
pp. 577-583 ◽  
Author(s):  
Natália R. Leite ◽  
Luci C.C. Pereira ◽  
Fernando Abrunhosa ◽  
Marcus A.B. Pires ◽  
Rauquírio M. da Costa
Keyword(s):  
River Estuary ◽  
Environmental Parameters ◽  
Reproductive Period ◽  
Subsurface Water ◽  
Dry Period ◽  
Rainy Period ◽  
Amazon Estuary ◽  
North Brazil ◽  
Number Of Individuals

The present work was carried out to verify the occurrence and distribution of Cymbasoma longispinosum Bourne, 1890 in a tropical Amazon estuary from North Brazil. Samplings were performed bimonthly from July/2003 to July/2004 at two different transects (Muriá and Curuçá rivers) situated along the Curuçá estuary (Pará, North Brazil). Samples were collected during neap tides via gentle (1 to 1.5 knots) 200 μm-mesh net tows from a small boat. Additional subsurface water samples were collected for the determination of environmental parameters. Males and females of Cymbasoma longispinosum were only observed during September and November/2003. The highest number of organisms was found in September/2003 at the Muriá River transect. The presence of C. longispinosum in samples obtained during September and November/2003 could probably be related to the reproductive period of this species in the studied estuary, which is directly related to the dry period in the region. The highest salinity values and the highest number of individuals observed in September/2003 corroborate with the previous assumption, since no C. longispinosum was found during the months comprising the rainy period (January to June).

scholarly journals Benthic Bacillariophyta of the Paripe River estuary in Pernambuco state, Brazil

2007 ◽  
Vol 67 (3) ◽  
pp. 393-401 ◽  
Author(s):  
AN. Moura ◽  
MC. Bittencourt-Oliveira ◽  
EC. Nascimento
Keyword(s):  
New Records ◽  
River Estuary ◽  
Benthic Diatom ◽  
Northeastern Brazil ◽  
Dry Period ◽  
Rainy Period ◽  
Infraspecific Taxa ◽  
Estuary Sediment

The aim of this study was to evaluate the benthic diatom composition from the estuary sediment in the Pernambuco State, based on 32 samples. Samples were collected monthly from September through December 1999 (dry period) and from April through July 2000 (rainy period) during four pre established sampling stations. Results indicated 19 families and 31 specific and infraspecific taxa. Eight new records were founded for Pernambuco State: Auliscus coelatus, Fallacia nummularia, Navicula algida, Plagiograma pulchellum, Terpsinoe americana, Triceratium antideluvianna and Tryblionella coarctata and one, Auliscus punctatus Bailey, in northeastern Brazil.

scholarly journals Periphytic algae dynamics in lentic ecosystems in the Brazilian semiarid

2016 ◽  
Vol 77 (3) ◽  
pp. 495-505 ◽  
Author(s):  
R. S. Cordeiro ◽  
J. E. L. Barbosa ◽  
G. Q. Lima Filho ◽  
L. G. Barbosa
Keyword(s):  
Aquatic Macrophytes ◽  
Soluble Reactive Phosphorus ◽  
Algal Community ◽  
Aquatic Communities ◽  
Dry Period ◽  
Rainy Period ◽  
Brazilian Semiarid ◽  
High Concentrations ◽  
Reactive Phosphorus ◽  
Reduced Density

Abstract The hydrological periods drive the structure and organization of aquatic communities in semiarid regions. We hypothesize that a decrease of the precipitation during the dry period will favor the development of the periphytic algal community, leading to higher richness and density in this period. To test this hypothesis, we investigated the changes in the periphytic algal community structure in three shallow and eutrophic ecosystems of the Brazilian semiarid. The sampling was performed between 2007 and 2010 at two-mensal intervals. The sampling of periphytic algal was performed in aquatic macrophytes and rocks. The abiotic variables were analyzed simultaneously. Dominance in diatoms, cyanobacteria and chlorophytes, respectively, was observed in two periods. In the dry period, waters were alkaline and had high concentrations of nitrate and total phosphorus associated with the highest densities of Bacillariophyceae. In the rainy period the water was warmer, oxygenated and high concentrations of ammonia and soluble reactive phosphorus with diatoms remained dominant but with reduced density, while cyanobacteria and chlorophytes increased. Overall, periphytic algal community composition no responded to changes in the hydrological periods. However, the hydrological periods altered the dynamics of periphytic algal community, supported by the alternation of the most representative classes (diatoms and cyanobacteria) between the hydrologic periods. Our data suggest that the morphometric and chemical and physical characteristics of lentic aquatic ecosystems studied were more important in the dynamics of periphytic algal community than the hydrological periods and types of substrates.

Is there a relation between serum methylarginine levels and infertility?

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yasin Saygın ◽  
Abdullah Sivrikaya ◽  
Turan Akdağ ◽  
Duygu Dursunoğlu ◽  
Mehmet Kaynar ◽  
...  
Keyword(s):  
Sperm Concentration ◽  
Reproductive Period ◽  
Healthy Individuals ◽  
Adma Level ◽  
Chromatography Tandem Mass Spectrometry ◽  
Potential Biomarker ◽  
Liquid Chromatography Tandem Mass ◽  
Arginine Residues ◽  
Dimethyl Arginine

Abstract Objectives Infertility is defined as the absence of pregnancy within the reproductive period despite regular sexual intercourse. Methylarginines are formed as a result of methylation of arginine residues in proteins and formed in three forms as asymmetric dimethyl arginine (ADMA), symmetrical dimethyl arginine (SDMA) and monomethylarginine (L-NMMA). So, here, we aimed to evaluate arginine and their derivatives levels in fertile and infertile individuals. Methods Present study were consist of 30 oligozoospermia patients (proven by spermiogram analysis) and 30 healthy individuals with normozoospermia group who were applied to the urology department. With blood samples taken from individuals, serum methylarginine and its derivatives levels were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Clinic data and demographic characteristics of individuals were also recorded at the same time. Results The serum ADMA level (0.38 ± 0.07) of the oligozoospermia group was found to be significantly higher than the normozoospermia group (0.35 ± 0.05) (p=0.046). A positive correlation were observed between ADMA and SDMA (r=0.686, p=0.000), HArg and SDMA (r=0.611, p=0.001), citrulline and L-NMMA (r=0.595, p=0.001) in patients with oligosospermia. The increase in SDMA, arginine and HArg levels and a decrease in L-NMMA and citrulline levels were not significant as statistically. Also, the ADMA level was found to be high in individuals with low sperm concentration. Conclusions Consequently, serum ADMA levels of individuals with oligozoospermia were statistically significantly higher than those with normozoospermia. As proposal, determination of ADMA levels may be a potential biomarker parameter in terms of early diagnosis of fertility and infertility.

scholarly journals Phytoplanktonic associations: a tool to understanding dominance events in a tropical Brazilian reservoir

2007 ◽  
Vol 21 (3) ◽  
pp. 641-648 ◽  
Author(s):  
Ariadne do Nascimento Moura ◽  
Maria do Carmo Bittencourt-Oliveira ◽  
Ênio Wocyli Dantas ◽  
João Dias de Toledo Arruda Neto
Keyword(s):  
Dissolved Oxygen ◽  
Trophic State ◽  
Nitrogen Concentration ◽  
Trophic State Index ◽  
Dry Period ◽  
Tropical Reservoir ◽  
Phytoplankton Assemblages ◽  
Reservoir Water ◽  
Rainy Period ◽  
State Index

The aim of this study was to characterize phytoplankton associations, as well as discuss controlling factors determining algal dominance in a eutrophic tropical reservoir, Mundaú, Pernambuco, Brazil. Water samples were collected during the dry period (January/2005) and the rainy period (June/2005). The samples were collected from both limnetic and littoral regions, and the phytoplankton assemblages identified from current literature after preservation in formaldehyde 4%. At the same time as sampling was done, in situ measurements of water temperature, transparency, dissolved oxygen, and pH were also taken. Total phosphorus, total nitrogen concentration and the Trophic State Index were subsequently determined in the laboratory. Phytoplankton density (ind. L-1) was estimated using an inverted Zeiss microscope. Grouping of the phytoplankton associations was carried out using the Reynolds phytosociological classification. During the dry period, reservoir water showed low dissolved oxygen concentrations, alkaline pH and was relatively turbid compared to the situation during the rainy season. Reservoir water is limited by nitrogen during both seasonal periods. The Trophic State Index is classified as determining eutrophic conditions. Phytoplankton was represented by 70 infrageneric taxa grouped in 16 functional associations, with the majority typical of eutrophic systems. This fact is supported by quantitative analysis, which shows the dominance of S associations comprising exclusively R-strategist cyanobacteria.

scholarly journals Mayfly diversity in the brazilian tropical headwaters of Serra do Cipó

2005 ◽  
Vol 48 (6) ◽  
pp. 983-996 ◽  
Author(s):  
Michael Goulart ◽  
Marcos Callisto
Keyword(s):  
Taxonomic Richness ◽  
Dry Period ◽  
Lotic Ecosystems ◽  
River Watershed ◽  
Rainy Period ◽  
Sao Francisco River ◽  
Serra Do Cipó ◽  
São Francisco River ◽  
Dry Seasons ◽  
Doce River

The objectives of this study were to evaluate spatial and seasonal distribution, assemblage structure and substrate associations of mayfly nymphs in five lotic ecosystems in the headwaters of the Doce River and São Francisco River watersheds, Brazil. Samples were taken in 24 sampling stations during rainy and dry seasons in 1998. In total, 7,066 organisms were collected, belonging to 27 genera and 6 families of Ephemeroptera. The dominant taxa were Americabaetis, Paracloeodes, Leptohyphes and Hagenulus. During the rainy period, the São Francisco River watershed showed higher taxonomic richness, diversity and evenness, while in the dry period, the taxonomic richness was higher in Doce River watershed. No significant differences were found in the taxonomic richness, diversity, evenness and density of mayfly assemblages between the two studied sampling periods. The results suggested that the diversity of the mayfly assemblages in tropical headwaters of Serra do Cipó would be probably due to ecosystem and watershed characteristics.

scholarly journals Longitudinal Study of Total and Pathogenic Vibrio parahaemolyticus (tdh+ and/or trh+) in Two Natural Extraction Areas of Mytilus chilensis in Southern Chile

2021 ◽  
Vol 12 ◽  
Author(s):  
Cristina Bacian ◽  
Cristobal Verdugo ◽  
Katherine García ◽  
Josu Perez-Larruscain ◽  
Ignacio de Blas ◽  
...  
Keyword(s):  
Water Temperature ◽  
Vibrio Parahaemolyticus ◽  
River Estuary ◽  
Environmental Parameters ◽  
Economic Losses ◽  
Pcr Analysis ◽  
Potential Hazard ◽  
Detection Rates ◽  
Pathogenic Vibrio ◽  
Interaction Factor

Vibrio parahaemolyticus is the leading cause of seafood-associated bacterial gastroenteritis worldwide. Although different studies have focused on its pattern of variation over time, knowledge about the environmental factors driving the dynamics of this pathogen, within the Chilean territory, is still lacking. This study determined the prevalence of total and pathogenic V. parahaemolyticus strains (tdh and/or trh genes) in mussels (Mytilus chilensis) collected from two natural growing areas between 2017 and 2018, using selective agar and PCR analysis. V. parahaemolyticus was detected in 45.6% (93/204) of pooled samples from the Valdivia River Estuary. The pathogenic strains carrying the tdh and/or trh gene were detected in 11.8% (24/204): tdh in 9.8% (20/204), trh in 0.5% (1/204), and 1.5% (3/204) presented both genes. In Reloncaví Fjord, V. parahaemolyticus was detected in 14.4% (30/209) of the samples, pathogenic V. parahaemolyticus carrying the trh gene was detected in 0.5% (1/209) of the samples, while the tdh gene was not detected in the samples from this area. The total count of mauve-purple colonies typical of V. parahaemolyticus on CHROMagar was positively associated by multivariate analysis with area, water temperature, and salinity. Similarly, V. parahaemolyticus detection rates by PCR had a positive correlation with the area and water temperature. The chances of detecting total V. parahaemolyticus in the Valdivia River Estuary are significantly higher than in the Reloncaví Fjord, but inversely, during spring-summer months, the interaction factor between the area and temperature indicated that the chances of detecting V. parahaemolyticus are higher in the Reloncaví Fjord. Interestingly, this period coincides with the season when commercial and natural-growing shellfish are harvested. On the other hand, pathogenic V. parahaemolyticus tdh+ was significantly correlated with an increase of water temperature. These environmental parameters could be used to trigger a warning on potential hazard, which would influence human health and economic losses in aquaculture systems.

scholarly journals Herpetofauna Distribution and Ecology in East Kutai District, East Kutai, East Kalimantan

2020 ◽  
Vol 5 (8) ◽  
pp. 279-284
Author(s):  
Sus Trimurti ◽  
Andi Sarina ◽  
Lariman .
Keyword(s):  
Diversity Index ◽  
Environmental Parameters ◽  
Microsoft Excel ◽  
Field Orientation ◽  
The Public ◽  
East Kalimantan ◽  
Recorded Data ◽  
Distribution And Ecology ◽  
Index Value ◽  
Number Of Individuals

Herpetofauna consisting of reptiles and amphibians is a group of fauna whose biodiversity potential is rarely known and is not well known by the public. The purpose of this study was to determine the distribution, ecology and diversity of herpetofauna in Mesangat Wetlands. The method used in this research is the Visual Encounter Survey (VES) search method by searching directly for the type of herpetofauna around the predetermined pathway. Field orientation is carried out to determine the location of the observation, the location of the observation is divided into 3 locations (Mesangat Hilir, Tengah and Hulu) in one observation location there are 5 stations (lanes) for herpetofauna observation. Observations were made in the morning starting at 09.00 - 12.00 WITA and at night starting at 20.00 - 23.00 WITA. Recorded data related to the number of individuals, activities, time found, environmental parameters and measured SVL if possible. Identified species were found using the identification key book Field Frogs of Borneo Inger and Stuebing (2014) and A Field Guide to the Snakes of Borneo Stuebing, Inger and Lardner (2014). The data were analyzed using Microsoft Excel 2010. The results showed that the distribution of herpetofauna in Mesangat Wetlands was fairly evenly distributed and the ecology of Mesangat Wetlands supported for herpetofauna life and the diversity index value obtained was 1.53 which was classified as medium category.

scholarly journals Methods Applied for Measurement and Visualization of Changes in Biodiversity

2015 ◽  
Vol 21 (4) ◽  
pp. 593-604 ◽  
Author(s):  
Grzegorz Łagód ◽  
Mariola Chomczyńska ◽  
Agnieszka Montusiewicz ◽  
Jacek Malicki ◽  
David Stransky
Keyword(s):  
Statistical Significance ◽  
Shannon Index ◽  
Taxon Richness ◽  
Profile Method ◽  
Maximum Value ◽  
Structural Capacity ◽  
The Monte Carlo Method ◽  
Number Of Individuals ◽  
Biological Differences

Abstract The article presents the possible methods for determining biological or statistically significant differences between taxocenoses compared with respect to biodiversity. To obtain a complete description of biological differences between the compared hypothetical communities, the following indices were calculated: S (taxon richness), H (the Shannon index), Hmax (the maximum value of the Shannon index for the richness of taxa represented by the same number of individuals), Vd (a percentage value of covering the structural capacity of community, “evenness deficiency”), E (the MacArthur index - a taxon number (S) in a community for which the observed value of H equals Hmax), and Ps (a taxon richness shortage in percents). Moreover, a graphic profile method (Дд, Tj, and Lj profiles) was used for comparing the diversity of the communities. To obtain information about statistically significant differences in biodiversity between the analysed communities, rarefaction curves were applied. The curves are based on the null models and the Monte Carlo method. The rarefaction method resulted in determination of the statistical significance of the differences between taxon richness and Shannon's index values for the compared communities. The Vd and Ps indices and the profile method allowed concluding about the significance of the biological differences between taxocenoses, even when their values of Shannon's H indices were numerically similar.

Sign in / Sign up

Export Citation Format

Share Document