scholarly journals Parasite-mediated microhabitat segregation between congeneric hosts

2018 ◽  
Vol 14 (2) ◽  
pp. 20170671 ◽  
Author(s):  
Olwyn C. Friesen ◽  
Robert Poulin ◽  
Clément Lagrue

Parasite-mediated competition can shape community structure and host distribution. If two species compete for resources, parasites may indirectly change the outcome of competition. We tested the role of a trematode parasite in mediating microhabitat use by congeneric isopods Austridotea annectens and Austridotea lacustris . Although both isopods share resources, they rarely co-occur in the same discrete microhabitats. We set up mesocosms with and without competition and/or parasites to examine the role of parasites in host distribution and habitat segregation. Austridotea annectens showed a clear preference for one microhabitat type regardless of competition or parasitic infection. By contrast, A. lacustris showed little habitat selection in the absence of competition, but favoured sandy habitats in the presence of uninfected A. annectens and rocky habitats when competing with infected A. annectens . Our results suggest that parasites in one species affect the distribution of another species, and mediate competition between these species. We demonstrated the impacts of a parasite on the microhabitat use of its host's competitor. This also represents an example of a super-extended phenotype, where a parasite affects the phenotype of a non-host.

1991 ◽  
Vol 18 (3) ◽  
pp. 333-362 ◽  
Author(s):  
MADELEINE LY-TIO-FANE

SUMMARY The recent extensive literature on exploration and the resulting scientific advances has failed to highlight the contribution of Austrian enterprise to the study of natural history. The leading role of Joseph II among the neutral powers which assumed the carrying trade of the belligerents during the American War of Independence, furthered the development of collections for the Schönbrunn Park and Gardens which had been set up on scientific principles by his parents. On the conclusion of peace, Joseph entrusted to Professor Maerter a world-encompassing mission in the course of which the Chief Gardener Franz Boos and his assistant Georg Scholl travelled to South Africa to collect plants and animals. Boos pursued the mission to Isle de France and Bourbon (Mauritius and Reunion), conveyed by the then unknown Nicolas Baudin. He worked at the Jardin du Roi, Pamplemousses, with Nicolas Cere, or at Palma with Joseph Francois Charpentier de Cossigny. The linkage of Austrian and French horticultural expertise created a situation fraught with opportunities which were to lead Baudin to the forefront of exploration and scientific research as the century closed in the upheaval of the Revolutionary Wars.


2020 ◽  
pp. 097300522096468
Author(s):  
Rajesh Gupta ◽  
Piyush Kumar Sinha ◽  
Akash Sahu ◽  
Vandana Sood

Craft industry is as much the mainstay of the rural economy after agriculture. It provides occupation to a large section of population. However, it is characterised by fragmented individual artisans on one side and dispersed customers on the other. It also suffers from market separations. Urban haats were set up with the objective to present artisans and buyer on one platform and reduce these separations. In this study urban haats have been conceptualised as marketplaces that bring artisans and customers at one place to optimise their respective values. They also serve as a tool for disintermediation and a social distribution initiative and represent a retailing initiative in the inclusive entrepreneurship domain. This study focusses on identifying drivers of success of urban haats. Using a mixed method approach, data was collected from Haat officials and NGO members through personal interviews. The data from artisans and customers was collected through a survey using a structured response format. The study was conducted at 18 haats in 10 states. The study highlights the factors that drive satisfaction of artisans and customers and the role of administrators in making the marketplace a success. Customer consider diversity of the products, quality of the products, behaviour of the salesperson, price parity with other markets, buying experience, parking space and aesthetics of the stalls as major influencing factors for the recommendation of the haats to other customers. Most important attributes of the haats in driving artisan satisfaction were stall allotment system, haat location, advertisements, product promotion and monitoring. It is also found that while the infrastructure is necessary, it is not sufficient in enhancing the performance and sustainability of haats. Administration of these haats plays a defining mediating role. Based on these findings, an approach is proposed for success of urban haats.


2021 ◽  
pp. 112972982110154
Author(s):  
Raffaella Mauro ◽  
Cristina Rocchi ◽  
Francesco Vasuri ◽  
Alessia Pini ◽  
Anna Laura Croci Chiocchini ◽  
...  

Background: Arteriovenous fistula (AVF) for hemodialysis integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes. Aim of this study is to determine the role of Ki67, a well-established proliferative marker, related to AVF, and its relationship with time-dependent histological morphologic changes. Materials and methods: All patients were enrolled in 1 year and stratified in two groups: (A) pre-dialysis patients submitted to first AVF and (B) patients submitted to revision of AVF. Morphological changes: neo-angiogenesis (NAG), myointimal thickening (MIT), inflammatory infiltrate (IT), and aneurysmatic fistula degeneration (AD). The time of AVF creation was recorded. A biopsy of native vein in Group A and of arterialized vein in Group B was submitted to histological and immunohistochemical (IHC) analysis. IHC for Ki67 was automatically performed in all specimens. Ki67 immunoreactivity was assessed as the mean number of positive cells on several high-power fields, counted in the hot spots. Results: A total of 138 patients were enrolled, 69 (50.0%) Group A and 69 (50.0%) Group B. No NAG or MIT were found in Group A. Seven (10.1%) Group A veins showed a mild MIT. Analyzing the Group B, a moderate-to-severe MIT was present in 35 (50.7%), IT in 19 (27.5%), NAG in 37 (53.6%); AD was present in 10 (14.5%). All AVF of Group B with the exception of one (1.4%) showed a positivity for Ki67, with a mean of 12.31 ± 13.79 positive cells/hot spot (range 0–65). Ki67-immunoreactive cells had a subendothelial localization in 23 (33.3%) cases, a myointimal localization in SMC in 35 (50.7%) cases. The number of positive cells was significantly correlated with subendothelial localization of Ki67 ( p = 0.001) and with NA ( p = 0.001). Conclusions: Native veins do not contain cycling cells. In contrast, vascular cell proliferation starts immediately after AVF creation and persists independently of the time the fistula is set up. The amount of proliferating cells is significantly associated with MIT and subendothelial localization of Ki67-immunoreactive cells, thus suggesting a role of Ki-67 index in predicting AVF failure.


2001 ◽  
Vol 12 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Ross W. Jamieson

As one of the most common artifact categories found on Spanish colonial sites, the wheel-made, tin-glazed pottery known as majolica is an important chronological and social indicator for archaeologists. Initially imported from Europe, several manufacturing centers for majolica were set up in the New World by the late sixteenth century. The study of colonial majolica in the Viceroyalty of Peru, which encompassed much of South America, has received less attention than ceramic production and trade in the colonial Caribbean and Mesoamerica. Prior to 1650 the Viceroyalty of Peru was supplied with majolica largely produced in the city of Panama Vieja, on the Pacific. Panama Vieja majolica has been recovered from throughout the Andes, as far south as Argentina. Majolica made in Panama Vieja provides an important chronological indicator of early colonial archaeological contexts in the region. The reproduction of Iberian-style majolica for use on elite tables was symbolically important to the imposition of Spanish rule, and thus Panamanian majolicas also provide an important indicator of elite status on Andean colonial sites.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 754
Author(s):  
Giulia Gaggi ◽  
Andrea Di Credico ◽  
Pascal Izzicupo ◽  
Giovanni Iannetti ◽  
Angela Di Baldassarre ◽  
...  

Parkinson’s disease (PD) is one of the most common neurodegenerative disease characterized by a specific and progressive loss of dopaminergic (DA) neurons and dopamine, causing motor dysfunctions and impaired movements. Unfortunately, available therapies can partially treat the motor symptoms, but they have no effect on non-motor features. In addition, the therapeutic effect reduces gradually, and the prolonged use of drugs leads to a significative increase in the number of adverse events. For these reasons, an alternative approach that allows the replacement or the improved survival of DA neurons is very appealing for the treatment of PD patients and recently the first human clinical trials for DA neurons replacement have been set up. Here, we review the role of chemical and biological molecules that are involved in the development, survival and differentiation of DA neurons. In particular, we review the chemical small molecules used to differentiate different type of stem cells into DA neurons with high efficiency; the role of microRNAs and long non-coding RNAs both in DA neurons development/survival as far as in the pathogenesis of PD; and, finally, we dissect the potential role of exosomes carrying biological molecules as treatment of PD.


Author(s):  
Lina Y Alkaissi ◽  
Martin E Winberg ◽  
Stéphanie DS Heil ◽  
Staffan Haapaniemi ◽  
Pär Myrelid ◽  
...  

Abstract Background The first visible signs of Crohn’s disease (CD) are microscopic erosions over the follicle-associated epithelium (FAE). The aim of the study was to investigate the effects of human α-defensin 5 (HD5) on adherent-invasive Escherichia coli LF82 translocation and HD5 secretion after LF82 exposure in an in vitro model of human FAE and in human FAE ex vivo. Methods An in vitro FAE-model was set up by the coculture of Raji B cells and Caco-2-cl1 cells. Ileal FAE from patients with CD and controls were mounted in Ussing chambers. The effect of HD5 on LF82 translocation was studied by LF82 exposure to the cells or tissues with or without incubation with HD5. The HD5 secretion was measured in human FAE exposed to LF82 or Salmonella typhimurium. The HD5 levels were evaluated by immunofluorescence, immunoblotting, and ELISA. Results There was an increased LF82 translocation across the FAE-model compared with Caco-2-cl1 (P < 0.05). Incubation of cell/tissues with HD5 before LF82 exposure reduced bacterial passage in both models. Human FAE showed increased LF82 translocation in CD compared with controls and attenuated passage after incubation with sublethal HD5 in both CD and controls (P < 0.05). LF82 exposure resulted in a lower HD5 secretion in CD FAE compared with controls (P < 0.05), whereas Salmonella exposure caused equal secretion on CD and controls. There were significantly lower HD5 levels in CD tissues compared with controls. Conclusions Sublethal HD5 reduces the ability of LF82 to translocate through FAE. The HD5 is secreted less in CD in response to LF82, despite a normal response to Salmonella. This further implicates the integrated role of antimicrobial factors and barrier function in CD pathogenesis.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 466
Author(s):  
Marie-Christine Carpentier ◽  
Cécile Bousquet-Antonelli ◽  
Rémy Merret

The recent development of high-throughput technologies based on RNA sequencing has allowed a better description of the role of post-transcriptional regulation in gene expression. In particular, the development of degradome approaches based on the capture of 5′monophosphate decay intermediates allows the discovery of a new decay pathway called co-translational mRNA decay. Thanks to these approaches, ribosome dynamics could now be revealed by analysis of 5′P reads accumulation. However, library preparation could be difficult to set-up for non-specialists. Here, we present a fast and efficient 5′P degradome library preparation for Arabidopsis samples. Our protocol was designed without commercial kit and gel purification and can be easily done in one working day. We demonstrated the robustness and the reproducibility of our protocol. Finally, we present the bioinformatic reads-outs necessary to assess library quality control.


2020 ◽  
Vol 9 (1) ◽  
pp. 71
Author(s):  
Julia Marente ◽  
Javier Avalos ◽  
M. Carmen Limón

Carotenoid biosynthesis is a frequent trait in fungi. In the ascomycete Fusarium fujikuroi, the synthesis of the carboxylic xanthophyll neurosporaxanthin (NX) is stimulated by light. However, the mutants of the carS gene, encoding a protein of the RING finger family, accumulate large NX amounts regardless of illumination, indicating the role of CarS as a negative regulator. To confirm CarS function, we used the Tet-on system to control carS expression in this fungus. The system was first set up with a reporter mluc gene, which showed a positive correlation between the inducer doxycycline and luminescence. Once the system was improved, the carS gene was expressed using Tet-on in the wild strain and in a carS mutant. In both cases, increased carS transcription provoked a downregulation of the structural genes of the pathway and albino phenotypes even under light. Similarly, when the carS gene was constitutively overexpressed under the control of a gpdA promoter, total downregulation of the NX pathway was observed. The results confirmed the role of CarS as a repressor of carotenogenesis in F. fujikuroi and revealed that its expression must be regulated in the wild strain to allow appropriate NX biosynthesis in response to illumination.


Author(s):  
Saubhagya Kumar Jena ◽  
Lipsa Mishra ◽  
Sushree Samiksha Naik ◽  
Shahnawaz Khan

AbstractObjectiveTo explore the perception on PCOS and its prevalence among adolescent and young women.MethodsThe study was conducted over 2 year period in a tertiary care teaching hospital from Eastern India. A pre-formed, validated questionnaire was used to record the details. Descriptive statistics was used to report the findings.ResultsOf 965 young patients with mean (SD) age 20.64 (2.1) years, 27 (2.79 %) were aware of an entity called PCOS. Awareness among adolescents with PCOS was 25.9 % (7/27). All aware patients belonged to the urban sector with professionals constituting around 48%, of which 11% were students. The major source of information among aware patients was from doctors (40.7%), and friends and Internet (25.9%); rest being from books, newspapers, and teachers. Majority (70%) were aware that diet restriction and exercise were the primary modalities of treatment, whereas, only 3.7% knew about the role of contraceptive pills in PCOS.ConclusionsAwareness regarding PCOS among the young women is very low mainly in the rural set up. Doctors and health staffs should play a major role in spreading awareness of the entity to prevent long term complications.


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