Development of swim bladder nematodes (Cystidicola spp.) in their intermediate hosts

1979 ◽  
Vol 57 (9) ◽  
pp. 1736-1744 ◽  
Author(s):  
J. D. Smith ◽  
M. W. Lankester

It has been confirmed experimentally that Cystidicola farionis develops to the infective third-stage in amphipods. The third stage was reached more quickly in Gammarus fasciatus (5 weeks) than in Hyalella azteca (6 weeks) at 12–14 °C and required 7 weeks to develop in Pontoporeia affinis at 5–7 °C. Third-stage larvae were 437 μm long immediately after the second moult and grew up to 4.9 mm long. Cystidicola cristivomeri developed to the third stage in Mysis relicta but not in amphipods. Third-stage larvae were about 720 μm long after the second moult and grew up to 5.7 mm long. Third-stage larvae of C. cristivomeri up to 10.8 mm long were found in 0.8% of M. relicta from a lake where lake trout were infected with the parasite. Third-stage larvae of C. farionis and C. cristivomeri grew considerably in the intermediate hosts and the gonads became well developed. Similar development has been reported in other cystidicolids but suggestions that larvae moult to the fourth stage in the intermediate host cannot be accepted.

Parasitology ◽  
1970 ◽  
Vol 60 (1) ◽  
pp. 97-122 ◽  
Author(s):  
J. F. A. Sprent

Several species of Australian python, Morelia spilotes variegatus, Liasis amethy-stinus, L. fuscus and L. childreni, were experimentally infected with eggs of Ophidascaris moreliae and the development of the larvae described. The first moult occurred in the egg, which survived and remained infective for over 7 years in moist conditions. The first moult occurred in 12 days and the second-stage larva in the egg was infective to mice in 14–21 days. After ingestion the larvae migrated to liver and lungs and in 21 days were mainly distributed throughout the subcutaneous tissues, particularly in the neck region and behind the ears. Growth occurred to about 8 mm; the larvae attained their infectivity for pythons after 5 weeks and retained it for more than a year. The second moult was not observed but it was assumed that the third stage was infective for pythons. Development to about the same length occurred in guinea-pigs and indigenous and laboratory rats and in the bandicoot (Isoodon obesulus). In the possum (Tricho-surus sp.) a more rapid growth occurred to about the same length. No growth occurred in tadpoles.After ingestion by pythons larvae migrated to the lungs, where they remained for 3 months or more, grew to a length of 45 mm and underwent the third moult. Larvae removed from the lungs and reingested by pythons returned to the lungs if they had been in the first python for less than 60 days. After this time, they remained in the stomach of the second python. During the third moult larvae underwent a marked constriction of the anterior end, moved up the trachea and became attached in the upper oesophagus as fourth-stage larvae. In mouse-infected M. spilotes the third moult occurred at 117 days at a length of 23–45 mm; fourth-stage larvae measured 34–50 mm. The fourth moult occurred in the stomach at 318 days at a length of 37–55 mm. The smallest adult specimens found were a 55 mm male and a 63 mm female. Development to the adult stage was only observed in M. spilotes variegatus. In other python species only pre-adult forms were recovered. It appeared that development may be retarded at the fourth moult during the winter. The morphology of the larvae during the five stages of development is described. It is concluded that the main growth phases are the third stage in the lungs of the python and the adult stage in the stomach of the python. Encapsulated forms were found only in the tissues of intermediate hosts. The larvae from mouse tissues emerged from the capsules during putrefaction and survived for several weeks in water.Acknowledgement is made to the able technical assistance of Miss Marian Hollis. Financial assistance for this study was provided under grants from the Australian Research Grants Committee and the United States Department of Health, Education and Welfare no. A 107023–02.


Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 131
Author(s):  
Matteo Zucchini ◽  
Arash Khosravi ◽  
Veronica Giorgi ◽  
Adriano Mancini ◽  
Davide Neri

The growth of cherry fruit is generally described using a double sigmoid model, divided into four growth stages. Abiotic factors are considered to be significant components in modifying fruit growth, and among these, the vapor pressure deficit (VPD) is deemed the most effective. In this study, we investigated sweet cherry fruit growth through the continuous, hourly monitoring of fruit transversal diameter over two consecutive years (2019 and 2020), from the beginning of the third stage to maturation (forth stage). Extensometers were used in the field and VPD was calculated from weather data. The fruit growth pattern up to the end of the third stage demonstrated three critical steps during non-rainy days: shrinkage, stabilization and expansion. In the third stage of fruit growth, a partial clockwise hysteresis curve of circadian growth, as a response to VPD, appeared on random days. The pattern of fruit growth during rainy days was not distinctive, but the amount and duration of rain caused a consequent decrease in the VPD and indirectly boosted fruit growth. At the beginning of the fourth stage, the circadian growth changed and the daily transversal diameter vs VPD formed fully clockwise hysteresis curves for most of this stage. Our findings indicate that hysteresis can be employed to evaluate the initial phenological phase of fruit maturation, as a fully clockwise hysteresis curve was observable only in the fourth stage of fruit growth. There are additional opportunities for its use in the management of fruit production, such as in precision fruit farming.


Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.


2020 ◽  
Vol 2 (3) ◽  
pp. 301-320
Author(s):  
Muhamad Sidik Triadi ◽  
Irfan Sanusi ◽  
Lida Imelda Cholidah

ABSTRAK Penulisan ini bertujuan untuk mengetahui manajemen humas radio Rama FM Bandung dalam meningkatkan pemasang iklan dari mulai tahapan perencanaan, pengorganisasian, pelaksanaan sampai dengan pengawasan, metode penelitian ini menggunakan metode kualitatif untuk mengetahui karakteristik  dengan cara berinteraksi secara langsung dan mendalam mengenai sebuah program dan ringkasan yang digambarkan pada konteks di atas mendasari untuk menggali dan mendeskripsikan kegiatan-kegiatan yang dijalankan oleh radio Rama FM Bandung dalam meningkatkan pemasang iklan. Analisis penelitian ini menggunakan deskriptif kualittaif. Hasil penelitian menunjukan bahwa kegiatan manajemen humas radio Rama FM Bandung dalam meningkatkan pemasang iklan dimulai pada tahapan pertama yaitu perencanaan pembuatan proposal, inovasi program, pengemasan iklan dan penyampaian iklan. Tahapan kedua yaitu pengorganisasian dengan komunikasi, membentuk team, pertimbangan tugas, dan persetujuan dari pimpinan. Tahapan ketiga yaitu pelaksanaan sesuai tugas, presentasi, pelaksanaan tugas sesuai susunan, pelaksanaan kegiatan. Tahap keempat yaitu pengawasan koordinasi, kinerja team yang bertugas, program yang berlangsung, dan pengawasan proses sebagai bahan evaluasi. Kata Kunci : Manajemen Humas; Meningkatkan; Pemasang Iklan. ABSTRACT This writing aims to determine radio public relations management Rama FM Bandung in increasing advertisers from the stages of planning, organizing, implementation to supervision, this research method uses a case study method to determine the characteristics by interacting directly and deeply about a case and summary illustrated in the above context underlying to explore and describe the activities carried out by radio Rama FM Bandung in improving advertisers. The analysis of this study uses descriptive qualitative. The results showed that the radio public relations management activities of Rama FM Bandung in increasing advertisers began in the first stage, namely the planning of making proposals, program innovation, packaging of advertisements and delivery of advertisements. The second stage is organizing with communication, forming teams, considering assignments, and approval from the leadership. The third stage is the implementation of tasks, presentations, implementation of tasks according to the arrangement, implementation of activities. The fourth stage is monitoring coordination, the performance of the team in charge, the ongoing program, and monitoring the process as an evaluation material. Keywords : Management Public Relations; Improve; Advertiser.


1978 ◽  
Vol 56 (4) ◽  
pp. 688-694 ◽  
Author(s):  
Stephen R. Kearney ◽  
Frederick F. Gilbert

Terrestrial gastropods were collected within the 1220-ha Himsworth Game Preserve in central Ontario during 1974 to determine their abundance and habitat preference. Collections from systematically arranged plots occurred 23 May to 4 June, 6 July to 14 July, and 26 August to 5 September. In all 16 498 gastropods were collected; 4351, in the first, 5622 in the second, and 6525 in the third collection period. Sixteen species were represented with Discus cronkhitei and Zonitoides arboreus accounting for 69.3% of the specimens. Deroceras laeve and Pallifera dorsalis were the most common slugs. Gastropods (excluding slugs) showed a significant preference for mixed forest and a significant aversion to open habitat types during all collection periods. Slugs were significantly less abundant in mixed forest and more abundant in open habitat types during the third collection period.Eight of the 16 species collected (80.1% of the specimens) have previously been identified as intermediate hosts of Parelaphostrongylus tenuis. However, only 19 third-stage larvae of P. tenuis were obtained from the 16450 gastropods digested in pepsin. It is proposed that Zonitoides arboreus in association with Betula papyrifera may be important components in the transmission of P. tenuis to cervids on the Himsworth Game Preserve.


Author(s):  
Rafael Lucyk MAURER ◽  
Carlos GRAEFF-TEIXEIRA ◽  
José Willibaldo THOMÉ ◽  
Luís Antônio CHIARADIA ◽  
Hiroko SUGAYA ◽  
...  

Angiostrongylus costaricensis is a nematode parasitic of rodents. Man may become infected by ingestion of the third stage larvae produced within the intermediate hosts, usually slugs from the family Veronicellidae. An epidemiological study carried out in a locality in southern Brazil (western Santa Catarina State) where these slugs are a crop pest and an important vector for A. costaricensis has documented for the first time the natural infection of Deroceras laeve with metastrongylid larvae. This small limacid slug is frequently found amid the folds of vegetable leaves and may be inadvertently ingested. Therefore D. laeve may have an important role in transmission of A. costaricensis to man.


2021 ◽  
Vol 64 (2) ◽  
pp. 309-320
Author(s):  
Mihajlo P. Fejsa

In this paper, the author compares chromatic terms in Ruthenian and Serbian. He focuses on the basic colour terms according to Berlin and Kay: white, black, red, green, yellow, blue, brown, purple, pink, orange, and grey. They have equivalents in both languages: Ruthenian bila – Serbian bela, čarna – crna, červena – crvena, željena – zelena, žovta / žolta – žuta, belava – plava, braon – braon, lilova – ljubičasta, celova – roze, pomarančecova /poma- randžecova – narandžasta, šiva – siva. The criterion of one-morpheme word is not appli- cable to the terms lilova, celova, and pomarančecova /pomarandžecova in Ruthenian, and ljubičasta and narandžasta in Serbian. It is applicable to the terms bila, čarna, červena, željena, žovta / žolta, belava, braon, and šiva. With the exception of braon, all these terms are derived from the Proto-Slavic language (*bеlъ, *čьrnъ, *čьrvenъ, *zelenъ, *žltъ, *polvь, and *sivъ). As far as the Berlin–Kay’s universal of seven phases of colour formation is con- cerned, our study of chromatic terminology confirms it. In accordance with the supposed first stage of development, the Ruthenian language has bila and čarna; according to the second stage, Ruthenian has červena; in accordance with the third stage, Ruthenian has že- ljena or žovta / žolta; according to the fourth stage, Ruthenian has žovta / žolta or željena; in accordance with the fifth stage, Ruthenian has belava; according to the sixth stage, it has braon; and in accordance with the seventh stage (even if we leave aside the multi-mor- pheme terms lilova, celova, and pomarančecova /pomarandžecova), it has šiva. Generally speaking, the usage of the terms is identical in both investigated languages but there are several differences (e.g. cibulja – beli luk, željena pasulja – boranija). The most frequent suffixes are -asta and -ista in Ruthenian, and -asta in Serbian.Most of the chromatic terms are of Slavic origin but there are several borrowings used for nuance purposes in recent decades, e.g. azurna, teget, akvamarin, tirkizna, and others. Some borrowings remain unchanged, e.g. in both languages blond, braon, drap, krem, bež, and oker, and only in Serbian lila and roze. Hungarian was the official language until the first decades of the 20th century (until the collapse of the Austro-Hungarian Monarchy in 1918), during which Ruthenian–Hungarian bilingualism reigned. That is the reason why several Hungarian colour names are found, e.g. in surnames (the Ruthenian surname Barna comes from Hungarian barna ‘brown’, Fekete/Feketa is from fekete ‘black’, and Vereš is from vörös ‘red’) and in the names of domestic animals (the Ruthenian horse name pejka [Serbian riđan] comes from Hungarian pej ‘brown’ and šarga [Serbian žutalj] is from sár- ga ‘yellow’). The general name for ‘colour’ comes from the German language (Ruthenian farba is from German Farbe).


Author(s):  
s. A. Chun ◽  
V. Atluri

The government services needed by citizens or businesses often require horizontal integration across autonomous government agencies. The information and services needed are typically scattered over different agencies in diverse formats, and therefore are not interoperable. This results in the so-called “stove-pipe” service and information paradigm, which raises a number of challenges. First, the service consumers, both citizens and businesses, face the challenging task of locating relevant services and information from a large number of documents scattered at different locations on the Web. Therefore, it is beneficial to have a system to locate and integrate available services that are tailored to individual preferences and needs according to regulations. Second, due to the fact that information is not shared among the different agencies, service consumers are required to re-enter certain data repeatedly to obtain interagency services. Service integration should allow sharing among agencies. Digital governments have been evolving with different focuses in terms of information and transaction services. The evolution has shown at least four different stages. At the first stage, with the Internet and the WWW, governments digitized paper forms and started to disseminate information with static Web pages, electronic forms, and data displays. The focus of this initial stage has been to make information digitally available on the Web. The transaction services tended to resort to off-line paper-based traditional methods (e.g., by submitting the printed form with a payment) such as by credit cards. In the second stage, governments started to provide services for the citizens by developing applications for service delivery and databases to support the transactions. The citizens and businesses can “pull down” the needed services and information through “active” interaction with individual agency Web sites separately, as in self-services. In both of these stages, the digital government efforts did not consider what other government agencies have been doing and how their services may be related to other agencies’ services. The information and service consumers need to “visit” each agency separately and actively search for information and services. The digital government up to this stage mimics the physical government, and citizens and business entities navigate digital boundaries instead of physical boundaries for complex services, such as business registration or welfare benefits. When agency interactions are needed, data and forms are forwarded in batch mode to other agencies through paper or fax, where the data is re-entered, or the digital data captured from a form is forwarded in a file via CD-ROM or a floppy disk. The streamlining of business processes within individual agencies may have been achieved, but not the streamlining of business processes across agencies. In the third stage, digital government agencies strive to provide seamless, integrated services by different agencies with sharing necessary information. The services and documents are organized such that they are easily identified and the consumers do not have to scour large amounts of information for the right ones. This stage of digital government is characterized as one-stop portal stage. In the fourth stage, the governments create digital environments where citizens’ participation is encouraged to define government policies and directions. The services up to the third stage are often enforced by government regulations and policies. These very rules and policies can be modified by citizens’ participation. In this fourth stage, digital government efforts focus on developing collaborative systems that allow collaboration among government agencies and citizens in order to reflect the constituents’ inputs. Today’s digital governments characterized by “self-service” and “one stop portal” solutions, between stages two and three, need to provide front-end (citizen-facing) tools to deliver relevant, customized information and services, and a back-end (processing) infrastructure to integrate, automate, manage, and control the service delivery. The service integrations vary according to user requirements and need to be dynamically achieved in an ad-hoc manner with personalized processes as end results.


1980 ◽  
Vol 58 (11) ◽  
pp. 1997-2005 ◽  
Author(s):  
Geoff A. Black ◽  
Murray W. Lankester

Third-stage larvae of Cystidicola cristivomeri White, 1941, and C. farionis Fischer, 1798, migrated directly via the pneumatic duct to the swim bladder of lake trout, Salvelinus namaycush, and rainbow trout, Salmo gairdneri, respectively. Larvae reached the swim bladder as early as 16 h after fish were infected using a stomach tube. At 4–10 °C, mature male and female C. cristivomeri and C. farionis were first recovered 67 and 210 days, and 112 and 235 days, respectively, after infection. Cystidicola cristivomeri is probably long-lived; there was no evidence that any died in lake trout infected for up to 600 days.Large numbers of third-stage cystidicolid larvae accumulated without maturing in the swim bladder of naturally infected lake whitefish, Coregonus clupeaformis, from Lake Nipigon, northwestern Ontario. When given to rainbow trout, these larvae matured and the adult nematodes were identical to C. farionis. These results suggest that the swim-bladder nematode that matures in lake whitefish is a distinct species.


2009 ◽  
Vol 163 (4) ◽  
pp. 348-356 ◽  
Author(s):  
Emanuele Brianti ◽  
Salvatore Giannetto ◽  
Donato Traversa ◽  
Sharon R. Chirgwin ◽  
Krishna Shakya ◽  
...  

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