The morphology and life-cycle of Cephalochlamys namaquensis (Cohn, 1906) (Cestoda: Pseudophyllidea) from Xenopus muelleri and X. laevis

Parasitology ◽  
1967 ◽  
Vol 57 (1) ◽  
pp. 187-200 ◽  
Author(s):  
June P. Thurston
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Morphological Characteristics ◽  
Fish Farm ◽  
Makerere University ◽  
Egg Capsules ◽  
University College ◽  
The Many ◽  
The Cost ◽  
Research Grant

Some morphological characteristics of Cephalochlamys namaquensis from Xenopus muelleri collected at Kajansi, Kampala, are described.Specimens of cestodes from other localities in Africa are compared with those from Kajansi in order to assess the reliability of the characters of the proposed genus Pseudocephalochlamys Yamaguti, 1959. Reasons are given for rejecting the genus.The embryonated, non-operculate egg capsules hatch at once in water. The ciliated coracidium is eaten by cyclopid copepods and the oncosphere rapidly penetrates through the mid-gut wall into the haemocoel. The procercoid develops a cercomer which moves actively during development and which retains the six hooks of the oncosphere. The procercoid develops the scolex, osmoregulatory canals and calcareous corpuscles typical of the adult while within the copepod. It is enclosed within a membrane. The procercoid is infective to Xenopus toads 20 days after being ingested by the copepod. No other intermediate host has been found.Thermocyclops infrequens Kiefer is the intermediate host at Kajansi, Kampala. The maximum number of C. namaquensis recovered from one toad was 103; usually there are between 1 and 6 per toad. Between 22% and 100% of Xenopus muelleri and X. laevis from different localities are infected with C. namaquensis.I wish to express by thanks to the Fisheries Officers and fishermen of Kajansi Fish Farm who have willingly caught Xenopus for me whenever required, and also to the many other people who have assisted me in getting specimens with which to work.I am also indebted to Mr L. Rugema who prepared most of the histological preparations, to Dr J. Green, Westfield College, London, who kindly identified Thermocyclops infrequens, and to Dr G. Rees, University College of Wales, Aberystwyth, who gave me many useful comments during the course of this work.A research grant from Makerere University College contributed towards the cost of obtaining specimens.

scholarly journals Experimental infection in Notodiaptomus sp. (Crustacea: Calanoida) with larvae of Camallanus sp. (Nematoda: Camallanidae)

2007 ◽  
Vol 59 (2) ◽  
pp. 382-386 ◽  
Author(s):  
M.L. Martins ◽  
L. Ghiraldelli ◽  
F. Garcia ◽  
E.M. Onaka ◽  
R.Y. Fujimoto
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Experimental Infection ◽  
Fish Farm ◽  
Pasteur Pipette ◽  
Xiphophorus Maculatus ◽  
Adult Females ◽  
Nematode Larvae ◽  
Petri Dishes ◽  
Susceptibility Tests

This trial registered the experimental infection viability with nematode larvae Camallanus sp. in Notodiaptomus sp., a crustacean, which can be an intermediate host. Adult females of nematode were dissected from the intestines of Xiphophorus maculatus (Osteichthyes: Poeciliidae), at a fish farm in the State of São Paulo. Females were slightly compressed for larvae release, collected with Pasteur pipette and separated on Petri dishes with 9ml filtered water at 28.1ºC, from zooplankton culture. Treatments consisted of Petri dishes with 60 and 105 copepods, in which 120, 150 and 210 larvae of nematode were added in four replications. Twenty-four and 36h after exposition to the larvae, the copepods were fixed in 70% alcohol to record the amount of fixed larvae. Twenty four hours after exposition, 60 copepods group with 120 larvae showed significantly higher prevalence (46.5%) when compared to 105 copepods and 120 larvae (33.2%). Thus, these answers suggested that 120 larvae were enough for a successful infectivity. Experimental infection was available and so, it was used as a pattern to life cycle studies of camallanid nematodes and hosts susceptibility tests.

scholarly journals First Report of the Aecial State of Melampsora larici-populina on Larix spp. in North America

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1242-1242 ◽  
Author(s):  
J. Grondin ◽  
M. Bourassa ◽  
R. C. Hamelin
Keyword(s):  
Life Cycle ◽  
North America ◽  
Morphological Characteristics ◽  
Pcr Amplification ◽  
Eastern North America ◽  
Populus Balsamifera ◽  
Specific Primers ◽  
Complete Life Cycle ◽  
Pathogenic Variation ◽  
The Many

Melampsora larici-populina Kleb. was reported for the first time in eastern North America during 2002, on Populus spp., its telial host (1). M. larici-populina, a heteroecious rust, alternates between species of Populus and Larix. Since M. larici-populina was observed again in 2003, we investigated the possibility that its basidiospores may infect larch (Larix spp.) resulting in spermogonia and aecia. Identification of Melampsora species from aeciospore morphology is difficult but urediniospores are distinctive. This is important since the native M. medusae also alternates between Populus and Larix spp. During the spring of 2004, aecia were observed on needles of exotic (Larix decidua Mill. and L. leptolepis (Siebold and Zucc.) Gordon) and indigenous (L. laricina (K. Koch)) larch in an arboretum in Lotbinière (Quebec, Canada) where M. larici-populina has previously been found. Larch needles with yellow blister-like fructifications were collected in May 2004 and fixed on top of petri plates to allow aeciospore release onto leaves of Jackii poplar (Populus balsamifera L. × P. deltoides Marsh.). After approximately 10 days, uredinia appeared on the abaxial surface of the poplar leaves. Some of the many needles collected yielded uredinia cultures on Jackii poplars. The majority of these cultures were identified as being M. larici-populina; one was M. medusae. M. larici-populina urediniospores were 32 to 48 μm long and possessed a characteristic apical bald spot. DNA was extracted from aecia and uredinia, and the internal transcribed spacer (ITS) of the ribosomal RNA gene was amplified in real-time polymerase chain reaction (PCR) by specific primers for M. medusae or M. larici-populina created from sequences (GenBank Accession Nos. AY429656 and AY429657). The 120 base pairs target fragments amplified only with the M. larici-populina specific primers with the 14 samples that were identified as M. larici-populina by morphological characteristics of the urediniospores. No PCR amplification was obtained with M. medusae primers. These results were not unexpected since larch has been previously reported as an aecial host of M. larici-populina elsewhere (2). The ability of M. larici-populina to overwinter and complete its life cycle has important consequences since it proves that it is established and can go through sexual reproduction. A complete life cycle in eastern North America may allow M. larici-populina to generate pathogenic variation that will challenge poplar breeders in this region. References: (1) L. Innes et al. Plant Dis. 88:85, 2004. (2) G. Newcombe et al. Plant Dis. 78:1218, 1994.

An acanthocephalan parasite boosts the escape performance of its intermediate host facing non-host predators

Parasitology ◽  
2008 ◽  
Vol 135 (8) ◽  
pp. 977-984 ◽  
Author(s):  
V. MEDOC ◽  
J.-N. BEISEL
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Definitive Host ◽  
Complex Life Cycle ◽  
Escape Performance ◽  
Intermediate Hosts ◽  
Host Condition ◽  
Gammarus Roeseli ◽  
The Cost ◽  
Acanthocephalan Parasite

SUMMARYAmong the potential effects of parasitism on host condition, the ‘increased host abilities’ hypothesis is a counterintuitive pattern which might be predicted in complex-life-cycle parasites. In the case of trophic transmission, a parasite increasing its intermediate host's performance facing non-host predators improves its probability of transmission to an adequate, definitive host. In the present study, we investigated the cost of infection with the acanthocephalanPolymorphus minutuson the locomotor/escape performance of its intermediate host, the crustaceanGammarus roeseli. This parasite alters the behaviour of its intermediate host making it more vulnerable to predation by avian definitive hosts. We assessed the swimming speeds of gammarids using a stressful treatment and their escape abilities under predation pressure. Despite the encystment ofP. minutusin the abdomen of its intermediate host, infected amphipods had significantly higher swimming speeds than uninfected ones (increases of up to 35%). Furthermore, when interacting with the non-host crustacean predatorDikerogammarus villosus, the highest escape speeds and greatest distances covered by invertebrates were observed for parasitized animals. The altered behaviour observed among the manipulated invertebrates supported the ‘increased host abilities’ hypothesis, which has until now remained untested experimentally. The tactic of increasing the ability of infected intermediate hosts to evade potential predation attempts by non-host species is discussed.

Schistosomes fromHippopotamus amphibiusL. II. The morphology ofSchistosoma edwardiensesp.nov.

Parasitology ◽  
1964 ◽  
Vol 54 (1) ◽  
pp. 67-72 ◽  
Author(s):  
June P. Thurston
Keyword(s):  
Animal Ecology ◽  
National Park ◽  
University Of California ◽  
Blood Fluke ◽  
Makerere University ◽  
University College ◽  
Hippopotamus Amphibius ◽  
Research Grant

The morphology of the adult blood flukeSchistosoma edwardiensesp.nov. fromHippopotamus amphibiusL. is described and compared with that of other species ofSchistosoma.I wish to acknowledge the receipt of a research grant from Makerere University College towards expenses incurred during this work. I should like to thank Captain F. Poppleton, Warden of the Queen Elizabeth National Park, Dr R. M. Laws, Nuffield Unit for Tropical Animal Ecology, and Dr W. M. Longhurst, University of California, for helping me to get specimens from the hippopotami, also Mr L. Rugema, histologist, for sectioning the worms.

Evaluation Of The Functional Of Space-Planning Arrangement Of A Building

2019 ◽  
pp. 4-9
Keyword(s):  
Numerical Simulation ◽  
Life Cycle ◽  
Initial Data ◽  
Objective Assessment ◽  
Objective Evaluation ◽  
Point Of View ◽  
Shopping Centers ◽  
Space Planning ◽  
Planning Decisions ◽  
The Cost

The article focuses on the problem of the lack of objective evaluation of space-planning arrangement of buildings as a creative approach of the architect to the performing of functional tasks by the object. It is proposed to create a methodology for assessing the functional of space-planning solutions of buildings on the basis of numerical simulation of functional processes using the theory of human flows. There is a description of the prospects of using this method, which makes it possible to increase the coefficient of compactness, materials and works saving, more efficient use of space, reduce the cost of the life cycle of the building, save human forces and time to implement the functional of the building. The necessary initial data for modeling on the example of shopping and shopping-entertainment centers are considered. There are three main tasks for algorithmization of the functional of shopping centers. The conclusion is made about necessity of development of a method for objective assessment of buildings from the point of view of ergonomics of space-planning decisions based on the study of human behavior in buildings of different purposes.

scholarly journals Optimal Renovation Strategies through Life-Cycle Analysis in a Pilot Building Located in a Mild Mediterranean Climate

2021 ◽  
Vol 11 (4) ◽  
pp. 1423
Author(s):  
José Manuel Salmerón Lissen ◽  
Cristina Isabel Jareño Escudero ◽  
Francisco José Sánchez de la Flor ◽  
Miriam Navarro Escudero ◽  
Theoni Karlessi ◽  
...  
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Mediterranean Climate ◽  
Building Envelope ◽  
Economic Life ◽  
Hot Water ◽  
Optimal Solutions ◽  
Building Stock ◽  
Existing Building ◽  
The Cost

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels); (2) at least 32% share for renewable energy; and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%.

The cost of green roofs disposal in a life cycle perspective: Covering the gap

Energy ◽  
2012 ◽  
Vol 48 (1) ◽  
pp. 406-414 ◽  
Author(s):  
Giorgia Peri ◽  
Marzia Traverso ◽  
Matthias Finkbeiner ◽  
Gianfranco Rizzo
Keyword(s):  
Life Cycle ◽  
Green Roofs ◽  
Life Cycle Perspective ◽  
The Cost

The Output of First Stage Larvae by Cats Infested with Aelurostrongylus abstrusus

1968 ◽  
Vol 42 (3-4) ◽  
pp. 295-298 ◽  
Author(s):  
J. M. Hamilton ◽  
A. W. McCaw
Keyword(s):  
Life Cycle ◽  
Great Britain ◽  
Intermediate Host ◽  
World Wide ◽  
Wide Distribution ◽  
Clinical Disease ◽  
Complex Life Cycle ◽  
Patent Period ◽  
Aelurostrongylus Abstrusus

Aelurostrongylus abstrusus, the lungworm of the cat, has a world wide distribution and has been reported from countries as far apart as America, Great Britain and Palestine. It has a complex life cycle insofar as a molluscan intermediate host is essential and it is possible that auxiliary hosts also play an important part. In Britain, the incidence of active infestation of cats with the parasite has been recorded as 19·4% (Lewis, 1927) and 6·6% (Hamilton, 1966) but the latter author found that, generally, the clinical disease produced by the parasite was of a mild nature. It is known that the average patent period of the infestation in the cat is 8–13 weeks and it seems likely that, in that time, a considerable number of first stage larvae would be evacuated. Information on that point is not available and the object of the following experiment was to ascertain the number of larvae produced by cats during the course of a typical infestation.

Letter to the Editor

PEDIATRICS ◽  
1994 ◽  
Vol 93 (1) ◽  
pp. 151-152
Author(s):  
Caroline Breese Hall ◽  
Harold S. Margolis
Keyword(s):  
Public Health ◽  
Private Practice ◽  
Clinton Administration ◽  
Health Issues ◽  
Childhood Immunization ◽  
Letter To The Editor ◽  
The Many ◽  
The Cost

We appreciate the concerned letter of Dr Jacobs and his thoughtful questions arising both from his knowledge of the recommendations and public health issues, as well as those of private practice. The cost of vaccines is an issue with which we must all be concerned. By highlighting the importance of childhood immunization the Clinton administration has engendered interest and, thus, optimism that efforts toward reducing the cost will be successful. However, we should remember that the many excellent studies that have analyzed the reasons why children are not being vaccinated have shown that cost is not the major factor, but access, difficulties, and obstacles, real and perceived, to obtaining immunizations are.

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