Galba truncatula (O.F. Müller, 1774) (Gastropoda, Lymnaeidae): the colonization of new stations on acid soil by low numbers of snails

2021 ◽  
Vol 57 ◽  
pp. 26
Author(s):  
Gilles Dreyfuss ◽  
Philippe Vignoles ◽  
Daniel Rondelaud
Keyword(s):  
Acid Soil ◽  
Galba Truncatula ◽  
Average Area ◽  
Number Of Individuals

Samples of 5, 10 or 20 adult Galba truncatula each were introduced into 25 slope rush beds and 24 road ditches on acid soil to study the colonization of these new sites by the snail. Surveys were conducted over the following eight years to determine the area where these G. truncatula colonized in these new stations and to count the number of overwintering snails in April or May. Snail populations were present in about 50% of the sites where samples of 5 snails each were introduced and in all sites when each sample included 10 or 20 snails. The average area of these habitats showed a peak before decreasing in the following years and this peak was all the more late as the sample introduced into the station increased in size. In contrast, snail abundance in all cases peaked in the second or third year after introduction and gradually decreased thereafter. In all cases, a concentration of snails was noted in the most upstream zone, whereas the number of individuals decreased gradually towards the downstream zone. These results demonstrate that a small number of snails (10 or 20 adults per sample) allow the development of a new population of G. truncatula in new acid soil stations.

Characteristics of Fasciola hepatica infections in Galba truncatula originating from riverbank populations

2010 ◽  
Vol 85 (1) ◽  
pp. 28-32 ◽  
Author(s):  
P. Vignoles ◽  
D. Rondelaud ◽  
G. Dreyfuss
Keyword(s):  
Fasciola Hepatica ◽  
Acid Soil ◽  
Spring Water ◽  
The Other ◽  
Breeding Method ◽  
Galba Truncatula ◽  
Post Exposure ◽  
Petri Dishes

AbstractFour geographical strains of Galba truncatula living on riverbanks (the first on a sedimentary soil and the other three on an acid soil) were subjected to bimiracidial exposures with Fasciola hepatica to study their aptitude for cercarial shedding and to count metacercariae in snails dissected at day 42 post-exposure. All snails were reared in 14-cm Petri dishes at 24°C, with the same spring water (60–73 mg/l of Ca2+) and the same diet (grass and lettuce leaves). Metacercariae of F. hepatica were noted in the four populations after a cercarial shedding or after snail dissection. However, in spite of the breeding method used, the characteristics of snail infections varied with the origin of each geographical strain. For example, the shell heights of infected snails at day 42 were close to those found for the corresponding adults in the field (6.8–8.0 mm for the population living on the sedimentary soil, but only 4.6–5.5 mm for another strain originating from the acid soil). This variability may be explained by assuming that the diet of these riverbank G. truncatula would be different from that of snails living in swampy meadows. However, another hypothesis based on the influence of snail habitat on the characteristics of snail life cannot be excluded.

Perceptual Learning of Vocoded Speech With and Without Contralateral Hearing: Implications for Cochlear Implant Rehabilitation

2020 ◽  
pp. 1-10
Author(s):  
Martin Chavant ◽  
Alexis Hervais-Adelman ◽  
Olivier Macherey
Keyword(s):  
Cochlear Implant ◽  
Perceptual Learning ◽  
Speech Signal ◽  
Training Phase ◽  
Monosyllabic Words ◽  
Low Pass ◽  
Contralateral Ear ◽  
Number Of Individuals ◽  
Insight Into ◽  
Vocoded Speech

Purpose An increasing number of individuals with residual or even normal contralateral hearing are being considered for cochlear implantation. It remains unknown whether the presence of contralateral hearing is beneficial or detrimental to their perceptual learning of cochlear implant (CI)–processed speech. The aim of this experiment was to provide a first insight into this question using acoustic simulations of CI processing. Method Sixty normal-hearing listeners took part in an auditory perceptual learning experiment. Each subject was randomly assigned to one of three groups of 20 referred to as NORMAL, LOWPASS, and NOTHING. The experiment consisted of two test phases separated by a training phase. In the test phases, all subjects were tested on recognition of monosyllabic words passed through a six-channel “PSHC” vocoder presented to a single ear. In the training phase, which consisted of listening to a 25-min audio book, all subjects were also presented with the same vocoded speech in one ear but the signal they received in their other ear differed across groups. The NORMAL group was presented with the unprocessed speech signal, the LOWPASS group with a low-pass filtered version of the speech signal, and the NOTHING group with no sound at all. Results The improvement in speech scores following training was significantly smaller for the NORMAL than for the LOWPASS and NOTHING groups. Conclusions This study suggests that the presentation of normal speech in the contralateral ear reduces or slows down perceptual learning of vocoded speech but that an unintelligible low-pass filtered contralateral signal does not have this effect. Potential implications for the rehabilitation of CI patients with partial or full contralateral hearing are discussed.

Optimal Experimental Design With Nesting of Persons in Organizations

2013 ◽  
Vol 221 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Gerard J. P. van Breukelen
Keyword(s):  
Repeated Measures ◽  
Optimal Number ◽  
Health Centers ◽  
Randomized Experiments ◽  
Optimal Sample ◽  
Treatment Conditions ◽  
Sampling Cost ◽  
Nested Designs ◽  
Simple Equations ◽  
Number Of Individuals

This paper introduces optimal design of randomized experiments where individuals are nested within organizations, such as schools, health centers, or companies. The focus is on nested designs with two levels (organization, individual) and two treatment conditions (treated, control), with treatment assignment to organizations, or to individuals within organizations. For each type of assignment, a multilevel model is first presented for the analysis of a quantitative dependent variable or outcome. Simple equations are then given for the optimal sample size per level (number of organizations, number of individuals) as a function of the sampling cost and outcome variance at each level, with realistic examples. Next, it is explained how the equations can be applied if the dependent variable is dichotomous, or if there are covariates in the model, or if the effects of two treatment factors are studied in a factorial nested design, or if the dependent variable is repeatedly measured. Designs with three levels of nesting and the optimal number of repeated measures are briefly discussed, and the paper ends with a short discussion of robust design.

Activation of regeneration of red and white pulp of the spleen after the combined transplantation of HSC and MSCS in terms of exposure to ionizing radiation

2017 ◽  
pp. 22-27
Author(s):  
И.Ю. Маклакова ◽  
Д.Ю. Гребнев ◽  
А.П. Ястребов
Keyword(s):  
Stem Cells ◽  
Ionizing Radiation ◽  
Hematopoietic Stem Cells ◽  
Morphometric Parameters ◽  
Hematopoietic Stem ◽  
Lymphoid Follicles ◽  
Average Area ◽  
Direct Technique ◽  
Average Size ◽  
Red Pulp

Цель - изучение влияния сочетанной трансплантации мультипотентных мезенхимальных стромальных (ММСК) и гемопоэтических стволовых клеток (ГСК), выделенных из плаценты, на регенерацию белой и красной пульпы селезенки в физиологических условиях и в условиях воздействия ионизующего излучения. Методика. Эксперименты выполнены белых лабораторных беспородных мышах-самцах. Облучение животных проводилось на гамма-терапевтической установке типа АГАТ-С с радионуклидным источником Co-60 типа ГИК-8-4, поглощенная доза составила 4,0 Гр, мощность поглощенной дозы 20 сГр/мин. Животным опытной группы внутривенно вводились аллогенные ММСК и ГСК соответственно в дозе 6 млн клеток/кг и 330 тыс. клеток/кг, суспендированные в 0,2 мл 0,9% раствора NaCl. Выделение гемопоэтических стволовых клеток осуществлялось методом прямой иммуномагнитной сепарации. Проводили морфометрию лимфоидных фолликулов селезенки (средняя площадь, средняя площадь В-зоны, средняя площадь герминативного центра, средняя площадь T-зоны), а также определялось среднее расстояние между центрами фолликулов и средняя клеточность красной пульпы. Результаты. Показано, что после воздействия ионизирующего излучения на фоне сочетанной трансплантации ММСК и ГСК происходит увеличение размеров лимфоидного фолликула за счет площади B-зоны фолликула, площади герминативного центра фолликула, восстановление содержания лимфобластов, пролимфоцитов и лимфоцитов до значений нормы. На фоне трансплантации ММСК и ГСК в условиях лучевой нагрузки установлено увеличение плотности клеток в красной пульпе селезенки и, как следствие, увеличение расстояния между центрами лимфоидных фолликулов. Увеличение плотности клеток в красной пульпе происходит как за счет увеличения содержания эритроидных клеток, так и за счет увеличения гранулоцитов. Заключение. Проведенные исследования свидетельствуют об эффективности сочетанной трансплантации ММСК и ГСК в отношении основных морфометрических показателей селезенки после воздействия ионизирующего излучения. The purpose of this work was to study the effect of combined transplantation of multipotent mesenchymal stromal (MSCS) and hematopoietic stem cells (HSCs) isolated from the placenta, on the regeneration of white and red pulp of the spleen under physiological conditions and in conditions of exposure to ionizing radiation. Methods. The experiments were performed with laboratory mice-males. We studied the influence of ionizing radiation dose of 4.0 Gy. Animals of the experimental group were intravenously infused into MMSC and GSK respectively at a dose of 6 million cells/kg and 330 thousand cells/kg, suspended in 0.2 ml of 0.9% NaCl solution. The selection of hematopoietic stem cells was carried out using the direct technique of immune magnetic separation. Were studied the following morphometric parameters of the spleen: the average area of lymphoid follicles, the average area of zone of lymphoid follicles, average size of germinal center of lymphoid follicles, average size T-zones of lymphoid follicles, the average distance between the centers of the follicles, the average cellularity of the red pulp. Results. As a result, of research obtained that after exposure to ionizing radiation on the background of combined transplantation of HSC and MSCS there is an increase in size of lymphoid follicle at the expense of area B-zone of the follicle, the area germinative center of the follicle, restoring the content of lymphoblasts and lymphoblasts and lymphocytes to normal values. On the background of transplantation MMSC and GSK in terms of radiation exposure changes and the red pulp of the spleen. The increase in the density of cells in the red pulp of the spleen and, as a consequence, of the increase of the distance between the centers of lymphoid follicles. The increase in the density of cells in the red pulp occurs due to the increase in the content of erythroid cells and by increasing granulocytes. Key words: ionizing radiation, multipotent mesenchymal stromal cells, hematopoietic stem cells, spleen, regeneration. Conclusion. Studies have shown the effectiveness of combined transplantation MSC and GSK in respect of the main morphometric parameters of the spleen after exposure to ionizing radiation.

Experience of using atraumatic ointment bandages based on peruvian balsam in the complex treatment of patients with chronic wound defects of the lower limbs

2020 ◽  
pp. 43-57
Author(s):  
Anna Tabuika
Keyword(s):  
Diabetes Mellitus ◽  
Staphylococcus Aureus ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Local Treatment ◽  
Lower Limbs ◽  
Complex Treatment ◽  
Average Area ◽  
Arterial Insufficiency ◽  
Significant Activation

The article reflects the results of a retrospective non-comparative study, the objects of which were 34 outpatient comorbid patients (15 of which are over 60 years old) with chronic wounds of the lower limbs developed against the background of varicosity, post-thrombotic disease, chronic arterial insufficiency of the lower limbs, diabetes mellitus or their combination. Their local treatment was carried out using atraumatic ointment dressing «Branolind N» containing Peruvian balsam. There were 23 women (67.6 %) and 11 men (32.4 %). In microbiological study prior to the beginning of treatment in 31 patients the growth of a pathogen of wound infection was revealed; in 19 patients — Staphylococcus aureus in monoculture and in various associations, in 6 patients — Pseudomonas aeruginosa in monoculture, in other cases — other pathogens. In 3 patients the pathogen was not detected. The average wound size was 34 cm2 . The phase of the wound process was additionally confirmed by cytological studies. After treatment the average area of the wound defect decreased by 10 cm2 and made 24 cm2 on average. Full healing of the wound defect occurred in 11 patients, the others had granulation and active marginal epithelization. There was also a decrease in bacterial semination of wounds, a change in composition of infection agents to less aggressive monoflora, and cytologically — a decrease in signs of inflammation against the background of significant activation of reparative processes.

Responses of Sunflower Genotypes to Aluminum in Acid Soil and Nutrient Solution 1

1974 ◽  
Vol 66 (2) ◽  
pp. 293-296 ◽  
Author(s):  
C. D. Foy ◽  
R. G. Orellana ◽  
J. W. Schwartz ◽  
A. L. Fleming
Keyword(s):  
Nutrient Solution ◽  
Acid Soil

The influence of lime application to the acid soil on bioavailability of phosphorus in runoff

1996 ◽  
Vol 33 (4-5) ◽  
pp. 297-301 ◽  
Author(s):  
Vít Sova
Keyword(s):  
Acid Soil ◽  
Simulated Rainfall ◽  
Laboratory Conditions ◽  
Lime Application ◽  
Runoff Sediment

The influence of lime application to the acid soil on the mobility of phosphorus (P) in runoff was investigated by simulated rainfall in laboratory conditions. The neutralization of the acid soil by appropriate amount of lime significantly increased the portion of loosely bound phosphates in runoff sediment This phenomenon influenced bioavailability of P in runoff which increased after the lime application.

Sign in / Sign up

Export Citation Format

Share Document