scholarly journals Between-individual variation in nematode burden among juveniles in a wild host

Parasitology ◽  
2016 ◽  
Vol 144 (2) ◽  
pp. 248-258 ◽  
Author(s):  
H. M. V. GRANROTH-WILDING ◽  
F. DAUNT ◽  
E. J. A. CUNNINGHAM ◽  
S. J. BURTHE
Keyword(s):  
Experimental Studies ◽  
Natural Populations ◽  
Gastrointestinal Nematode ◽  
Hatch Date ◽  
Host Sex ◽  
Wild Host ◽  
Proxy Measure ◽  
Survival And Reproduction ◽  
Almost All

SUMMARYParasite infection in young animals can affect host traits related to demographic processes such as survival and reproduction, and is therefore crucial to population viability. However, variation in infection among juvenile hosts is poorly understood. Experimental studies have indicated that effects of parasitism can vary with host sex, hatching order and hatch date, yet it remains unclear whether this is linked to differences in parasite burdens. We quantified gastrointestinal nematode burdens of wild juvenile European shags (Phalacrocorax aristotelis) using two in situ measures (endoscopy of live birds and necropsy of birds that died naturally) and one non-invasive proxy measure (fecal egg counts (FECs)). In situ methods revealed that almost all chicks were infected (98%), that infections established at an early age and that older chicks hosted more worms, but FECs underestimated prevalence. We found no strong evidence that burdens differed with host sex, rank or hatch date. Heavier chicks had higher burdens, demonstrating that the relationship between burdens and their costs is not straightforward. In situ measures of infection are therefore a valuable tool in building our understanding of the role that parasites play in the dynamics of structured natural populations.

IN SITU AND PILOT ORGAN PERFUSION TECHNIQUES FOR THE STUDY OF METABOLIC DYNAMICS

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S9-S25 ◽  
Author(s):  
John Urquhart ◽  
Nancy Keller
Keyword(s):  
Cardiac Output ◽  
Large Fraction ◽  
Experimental Studies ◽  
Test Substance ◽  
Organ Perfusion ◽  
Systemic Blood ◽  
Experimental Control ◽  
Arterial Blood ◽  
Vascular Connections

ABSTRACT Two techniques for organ perfusion with blood are described which provide a basis for exploring metabolic or endocrine dynamics. The technique of in situ perfusion with autogenous arterial blood is suitable for glands or small organs which receive a small fraction of the animal's cardiac output; thus, test stimulatory or inhibitory substances can be added to the perfusing blood and undergo sufficient dilution in systemic blood after passage through the perfused organ so that recirculation does not compromise experimental control over test substance concentration in the perfusate. Experimental studies with the in situ perfused adrenal are described. The second technique, termed the pilot organ method, is suitable for organs which receive a large fraction of the cardiac output, such as the liver. Vascular connections are made between the circulation of an intact, anaesthetized large (> 30 kg) dog and the liver of a small (< 3 kg) dog. The small dog's liver (pilot liver) is excised and floated in a bath of canine ascites, and its venous effluent is continuously returned to the large dog. Test substances are infused into either the hepatic artery or portal vein of the pilot liver, but the small size of the pilot liver and its blood flow in relation to the large dog minimize recirculation effects. A number of functional parameters of the pilot liver are described.

scholarly journals Diversity of Biodeteriorative Bacterial and Fungal Consortia in Winter and Summer on Historical Sandstone of the Northern Pergola, Museum of King John III’s Palace at Wilanow, Poland

2021 ◽  
Vol 11 (2) ◽  
pp. 620
Author(s):  
Magdalena Dyda ◽  
Agnieszka Laudy ◽  
Przemyslaw Decewicz ◽  
Krzysztof Romaniuk ◽  
Martyna Ciezkowska ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Microbial Community Composition ◽  
Fungal Communities ◽  
Bacterial Strains ◽  
Microbial Biodiversity ◽  
Acidophilic Bacteria ◽  
Almost All ◽  
Generation Sequencing ◽  
King John

The aim of the presented investigation was to describe seasonal changes of microbial community composition in situ in different biocenoses on historical sandstone of the Northern Pergola in the Museum of King John III’s Palace at Wilanow (Poland). The microbial biodiversity was analyzed by the application of Illumina-based next-generation sequencing methods. The metabarcoding analysis allowed for detecting lichenized fungi taxa with the clear domination of two genera: Lecania and Rhinocladiella. It was also observed that, during winter, the richness of fungal communities increased in the biocenoses dominated by lichens and mosses. The metabarcoding analysis showed 34 bacterial genera, with a clear domination of Sphingomonas spp. across almost all biocenoses. Acidophilic bacteria from Acidobacteriaceae and Acetobacteraceae families were also identified, and the results showed that a significant number of bacterial strains isolated during the summer displayed the ability to acidification in contrast to strains isolated in winter, when a large number of isolates displayed alkalizing activity. Other bacteria capable of nitrogen fixation and hydrocarbon utilization (including aromatic hydrocarbons) as well as halophilic microorganisms were also found. The diversity of organisms in the biofilm ensures its stability throughout the year despite the differences recorded between winter and summer.

scholarly journals Olfactory processing in the lateral horn of Drosophila

2021 ◽  
Vol 383 (1) ◽  
pp. 113-123
Author(s):  
Sudeshna Das Chakraborty ◽  
Silke Sachse
Keyword(s):  
Functional Properties ◽  
Olfactory System ◽  
Cell Types ◽  
Specific Cell ◽  
Olfactory Behavior ◽  
Lateral Horn ◽  
Behavioral Decision ◽  
Animal Phyla ◽  
Survival And Reproduction ◽  
Almost All

AbstractSensing olfactory signals in the environment represents a crucial and significant task of sensory systems in almost all organisms to facilitate survival and reproduction. Notably, the olfactory system of diverse animal phyla shares astonishingly many fundamental principles with regard to anatomical and functional properties. Binding of odor ligands by chemosensory receptors present in the olfactory peripheral organs leads to a neuronal activity that is conveyed to first and higher-order brain centers leading to a subsequent odor-guided behavioral decision. One of the key centers for integrating and processing innate olfactory behavior is the lateral horn (LH) of the protocerebrum in insects. In recent years the LH of Drosophila has garnered increasing attention and many studies have been dedicated to elucidate its circuitry. In this review we will summarize the recent advances in mapping and characterizing LH-specific cell types, their functional properties with respect to odor tuning, their neurotransmitter profiles, their connectivity to pre-synaptic and post-synaptic partner neurons as well as their impact for olfactory behavior as known so far.

Photoinhibition of DCMU-Enhanced Fluorescence in Lake Ontario Phytoplankton

1987 ◽  
Vol 44 (12) ◽  
pp. 2144-2154 ◽  
Author(s):  
M. Putt ◽  
G. P. Harris ◽  
R. L. Cuhel
Keyword(s):  
Vertical Mixing ◽  
Natural Populations ◽  
Bright Light ◽  
Euphotic Zone ◽  
Lake Ontario ◽  
Enhanced Fluorescence ◽  
Low Light ◽  
Light Levels ◽  
Phosphorus Status

Measurement of 1-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) enhanced fluorescence (FDCMU) suggested that photoinhibition of photosynthesis was frequently an artifact of in situ bottle incubations in Lake Ontario phytoplankton. In a seasonal study, FDCMU of all populations was depressed by bright light in an incubator. However, when the euphotic zone did not exceed the depth of the mixed layer, vertical transport of phytoplankton into either low-light or dark regions apparently allowed reversal of photoinhibition of FDCMU. Advantages of FDCMU as a bioassay of vertical mixing include rapidity of response time, ease of measurement in the field, and insensitivity of this parameter to changes in phosphorus status of the population. Because of seasonal changes in the photoadaptive response of natural populations, the rate constants and threshold light levels required to cause the response must be determined at each use if the method is to be quantitative.

scholarly journals Genotypic diversity of S. mutans in dental biofilm formed in situ under sugar stress exposure

2007 ◽  
Vol 18 (3) ◽  
pp. 185-191 ◽  
Author(s):  
Rodrigo Alex Arthur ◽  
Cínthia Pereira Machado Tabchoury ◽  
Renata de Oliveira Mattos-Graner ◽  
Altair A. Del Bel Cury ◽  
Adriana Franco Paes Leme ◽  
...  
Keyword(s):  
Genotypic Diversity ◽  
Negative Control ◽  
Stress Exposure ◽  
Chain Reaction ◽  
Dental Biofilm ◽  
Polymerase Chain ◽  
Fermentable Carbohydrates ◽  
Almost All ◽  
Frequent Exposure

In situ dental biofilm composition under sugar exposure is well known, but sugar effect on the genotypic diversity of S. mutans in dental biofilm has not been explored. This study evaluated S. mutans genotypic diversity in dental biofilm formed in situ under frequent exposure to sucrose and its monosaccharide constituents (glucose and fructose). Saliva of 7 volunteers was collected for isolation of S. mutans and the same volunteers wore intraoral palatal appliances, containing enamel slabs, which were submitted to the following treatments: distilled and deionized water (negative control), 10% glucose + 10% fructose (fermentable carbohydrates) solution or 20% sucrose (fermentable and EPS inductor) solution, 8x/day. After 3, 7 and 14 days, the biofilms were colleted and S. mutans colonies were isolated. Arbitrarily primed polymerase chain reaction (AP-PCR) of S. mutans showed that salivary genotypes were also detected in almost all biofilm samples, independently of the treatment, and seemed to reflect those genotypes present at higher proportion in biofilms. In addition to the salivary genotypes, others were found in biofilms but in lower proportions and were distinct among treatment. The data suggest that the in situ model seems to be useful to evaluate genotypic diversity of S. mutans, but, under the tested conditions, it was not possible to clearly show that specific genotypes were selected in the biofilm due to the stress induced by sucrose metabolism or simple fermentation of its monosaccharides.

scholarly journals Comparative molecular cytogenetics in Melipona Illiger species (Hymenoptera, Apidae)

Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 696 ◽  
Author(s):  
Vanderly Andrade-Souza ◽  
Olivia Maria Pereira Duarte ◽  
Cinthia Caroline Cardoso Martins ◽  
Igor Silva Santos ◽  
Márcio Gilberto Cardoso Costa ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Number ◽  
Fluorescent In Situ Hybridization ◽  
Molecular Cytogenetics ◽  
Fluorochrome Staining ◽  
Rdna Sites ◽  
Cytogenetic Studies ◽  
Melipona Species ◽  
Almost All

Cytogenetic studies in Melipona are scarce with only 24 species analyzed cytogenetically. Of these, six species had the rDNA sites physically mapped and characterized by Fluorescent in situ Hybridization (fish). The aim of this study was to perform karyotype analyzes on Melipona species from different regions of Brazil, with a greater sampling representative of the Amazonian fauna and using conventional, fluorochrome staining and FISH with heterologous rDNA probes. The predominant chromosome number was 2n = 18, however, the subspecies M. seminigra abunensis and M. s. pernigra showed 2n = 22 chromosomes. The karyotypes were symmetrical, however M. bicolor, M. quadrifasciata, M. flavolineata, M. fuscopilosa, M. nebulosa presented the first pair heteromorphic in length. CMA3+ blocks also exhibited heteromorphism of size and in almost all cases coincided with rDNA sites, except for M. crinita and M. nebulosa, which presented additional non-coincident CMA3+ blocks. The CMA/ rDNA sites were terminal and interstitial in species with high heterochromatic content, and pericentromeric in those species with low heterochromatic content. In addition to pointing out cytogenetic features of cytotaxonomic importance, the reorganization of the genome in Melipona is discussed.

scholarly journals STATISTICAL STUDIES ON PROTEIN POLYMORPHISM IN NATURAL POPULATIONS II. GENE DIFFERENTIATION BETWEEN POPULATIONS

Genetics ◽  
1978 ◽  
Vol 88 (2) ◽  
pp. 367-390
Author(s):  
Ranajit Chakraborty ◽  
Paul A Fuerst ◽  
Masatoshi Nei
Keyword(s):  
Genetic Differentiation ◽  
Natural Populations ◽  
Drift Theory ◽  
Alternative Hypotheses ◽  
Mean And Variance ◽  
Statistical Studies ◽  
Different Populations ◽  
Using Data ◽  
Almost All ◽  
Good Agreement

ABSTRACT With the aim of testing the validity of the mutation-drift hypothesis, we examined the pattern of genetic differentiation between populations by using data from Drosophila, fishes, reptiles, and mammals. The observed relationship between genetic identity and correlation of heterozygosities of different populations or species was generally in good agreement with the theoretical expectations from the mutation-drift theory, when the variation in mutation rate among loci was taken into account. In some species of Drosophila, however, the correlation was unduly high. The relationship between the mean and variance of genetic distance was also in good agreement with the theoretical prediction in almost all organisms. We noted that both the distribution of heterozygosity within species and the pattern of genetic differentiation between species can be explained by the same set of genetic parameters in each group of organisms. Alternative hypotheses for explaining these observations are discussed.

scholarly journals Gaseous neurotransmitter nitric oxide: Its role in experimental models of epilepsy

2012 ◽  
Vol 64 (3) ◽  
pp. 1207-1216 ◽  
Author(s):  
D. Hrncic ◽  
Aleksandra Rasic-Markovic ◽  
Jelica Bjekic-Macut ◽  
Veselinka Susic ◽  
D. Mladenovic ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Experimental Studies ◽  
Experimental Models ◽  
Initiation And Propagation ◽  
Organ Systems ◽  
The Central Nervous System ◽  
Animal Models Of Epilepsy ◽  
Almost All ◽  
Gaseous Neurotransmitter ◽  
Models Of Epilepsy

Epilepsy is one of the leading neurological disorders and affects 1-2% of the world?s population. Generally, it is a result of an imbalance between excitatory and inhibitory phenomena in the central nervous system (CNS), but the mechanisms of its initiation and propagation still require further investigations. Experimental models represent one of the most powerful tools to better understand the mechanisms of epileptogenesis. Nitric oxide (NO) is gaseous molecule with pleiotropic physiological and pathological effects in almost all organ systems and intriguing biological relevance, especially in the CNS where it acts as a gaseous neurotransmitter. The role of NO in the generation of epilepsy is highly contradictory, since there is evidence of its anticonvulsive, as well as proconvulsive properties. Therefore, we will discuss in this review the involvement of NO-mediated signaling pathways in the mechanisms of epileptogenesis, taking into account the findings revealed in experimental studies on animal models of epilepsy.

scholarly journals Population and reproductive traits of a freshwater amphipod (Crustacea, Peracarida, Hyalellidae) from northwest of the state of Rio Grande do Sul, Brazil

2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Daniela da Silva Castiglioni ◽  
Marcio Limberger ◽  
Vanessa da Silva Castro ◽  
Francieli Ubessi
Keyword(s):  
No Reduction ◽  
Natural Populations ◽  
Reproductive Traits ◽  
Bimodal Distribution ◽  
Southern Brazil ◽  
Natural Pond ◽  
Males And Females ◽  
The Mean ◽  
Anthropic Influence ◽  
Almost All

Abstract The study of population and reproductive traits provides information about the ecological structure of natural populations. This study aimed to characterize dynamics and reproductive traits of Hyalella palmeirensis from a natural pond from southern Brazil. The amphipods were sampled monthly (August 2012 to July 2013) by a person with the aid of a hand net for 20 minutes. Ovigerous females and pre-copulatory pairs were individualized in the field. A total of 12,325 individuals were sampled, being 1,421 males, 6,983 females (including 215 ovigerous females) and 3,921 juveniles. Paired and unpaired males were significantly greater in size than females. There was a positive correlation between body size (CL) of paired males and females. Males and females showed bimodal distribution. Total sex ratio favored females, and these were more frequent in almost all months. Ovigerous females and precopulatory pairs were found throughout the year, but with high frequency in winter and autumn, respectively, characterizing a seasonal reproduction. Juveniles were sampled throughout the year, with greater intensity in the spring. The mean fecundity was 19.6 ± 4.34 eggs. No reduction in the number of eggs was observed during embryonic development. The results observed in H. palmeirensis demonstrate that this species has a population and reproductive dynamics very similar to other species of Hyalella already analyzed in southern Brazil. Moreover, it can be seen that although the H. palmeirensis occurs in an environment with anthropic influence (soy cultivation,) the population is managing to remain in the area, with reproduction and recruitment in most months of year.

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