Observations on Scale Production in Pyramimonas Amylifera Conrad

1966 ◽  
Vol 1 (4) ◽  
pp. 429-438
Author(s):  
IRENE MANTON
Keyword(s):  
Developmental Stages ◽  
Basic Problem ◽  
Scale Production ◽  
Body Type ◽  
Primary Object ◽  
Large Numbers ◽  
Golgi Structure ◽  
Flagellar Scales ◽  
Duct Opening ◽  
Narrow Duct

Scale production has been studied after glutaraldehyde fixation with the primary object of tracing the source of flagellar scales which this species is known to possess (Manton, Oates & Parke, 1963). Large numbers of all types of flagellar scales, unmixed with body-type scales, are detectable at all times, stored in an orderly arrangement within a vesicular scale reservoir of characteristic morphology which is described. These scales are liberated through a narrow duct opening to the cell exterior near the flagellar bases. This duct is thought to be temporary and subject to reformation with minor change of site, since open ducts are more frequently encountered in darkness than by day; some putative developmental stages are illustrated. Observations on other details of scale production include demonstration of the formation of all types of body scales within the Golgi cisternae, sometimes together with a few flagella-type scales. The larger body-type scales are uniformly oriented within the Golgi cisternae in relation to the position of the subtending endoplasmic reticulum. This orientation is lost before liberation to the cell surface, which occurs from moderate-sized detached vesicles in an unknown manner. The implications of these findings for an understanding of Golgi structure and of the basic problem of scale arrangement on the receiving sites are discussed in a preliminary way.

scholarly journals Evaluation of Effective and Practical Euthanasia Methods for Larval African Clawed Frogs (Xenopus laevis)

2020 ◽  
Vol 59 (3) ◽  
pp. 269-274
Author(s):  
Ilana A Galex ◽  
Cameron M Gallant ◽  
Nicole D'Avignon ◽  
Lauren M Kuchenbrod ◽  
Craig A Fletcher ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Developmental Stages ◽  
Age Group ◽  
Research Model ◽  
Larval Stages ◽  
Large Numbers ◽  
Guidance Documents ◽  
Stock Solutions ◽  
Tricaine Methanesulfonate ◽  
Tank Water

Larval, or tadpole-stage Xenopus laevis frogs are a popular research model for developmental biology and disease studies. Existing euthanasia guidance documents offer recommendations for both eggs and adult stages, yet do not specifically address the larval stage. Data evaluating effective euthanasia methods for groups of X. laevis tadpoles would therefore be useful. The goal of the current study was to evaluate the efficacy of various immersion euthanasia procedures on tadpoles: tricaine methanesulfonate (MS222) at 6 g/L, eugenol at 800 μL/L and rapid chilling (2 to 4 °C). We also evaluated tadpoles at various developmental stages (NF stages 46, 47 and 49). Tadpoles (n = 70) were exposed to euthanasia solution for 15 min, and controls (n = 40) were placed in housing tank water for 15 min. All animals were then placed in recovery tanks containing housing tank water for 4 h to confirm irreversibility of each agent. Cessation of the heartbeat was assessed at the end of euthanasia solution exposure and at each hour thereafter. We found that immersion in a 6 g/L solution of MS222 resulted in 100% euthanasia of all larval stages tested. Conversely, eugenol produced variable euthanasia rates that were affected by both age group and batches of stock solutions. Rapid chilling was completely ineffective as a euthanasia method in our study. Based on our findings, we recommend MS222 as an effective and practical means of euthanizing large numbers of X. laevis tadpoles.

Observations on the gregarine Rotundula gammari (Diesing, 1859), Goodrich, 1949

Parasitology ◽  
1964 ◽  
Vol 54 (1) ◽  
pp. 195-199 ◽  
Author(s):  
C. C. Narasimhamurti
Keyword(s):  
Developmental Stage ◽  
Royal Society ◽  
Developmental Stages ◽  
Local Population ◽  
Gammarus Pulex ◽  
Taxonomic Relationship ◽  
Large Numbers ◽  
The Many ◽  
Relationship Of ◽  
Infected Material

1. A local population of Gammarus pulex, infected with Heliospora longissima and Rotundula gammari, was found to have an intracellular developmental stage.2. Experimental infections of G. pulex were made with the two species of gregarines. In the case of R. gammari infections, large numbers of intracellular developmental stages were found.3. The taxonomic relationship of the genera Cephaloidophora and Rotundula is discussed.Thanks are due to Dr P. Tate for constant encouragement and guidance during the course of this work and for the many helpful suggestions in the preparation of the manuscript. Thanks are also due to Mr D. W. T. Crompton for kindly giving me the infected material. The work was completed during the tenure of a Royal Society and Nuffield Foundation Commonwealth Bursary.

Vegetative propagation of Sitka spruce

1987 ◽  
Vol 93 (1-2) ◽  
pp. 197-203
Author(s):  
Allan John ◽  
Bill Mason
Keyword(s):  
Tissue Culture ◽  
Large Scale ◽  
Sitka Spruce ◽  
Scale Production ◽  
Stem Cuttings ◽  
Culture Techniques ◽  
Commercial Trial ◽  
Large Numbers ◽  
Large Scale Production ◽  
Tissue Culture Techniques

SynopsisA combination of two vegetative techniques is seen as a possibility for large-scale production of juvenile, rooted Sitka spruce cuttings of improved genotype. Tissue culture techniques, under development, would be used to produce large numbers of stock plants for stem cuttings production. Cuttings techniques, currently under commercial trial, would be used to produce the rooted plants for forest establishment.

scholarly journals Somatic Embryogenesis of the Cedars of Lebanon (Cedrus libani)

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 461G-462
Author(s):  
S.N. Talhouk ◽  
M. Shmoury ◽  
R. Baalbaki ◽  
S. Khuri
Keyword(s):  
Somatic Embryogenesis ◽  
Callus Induction ◽  
Embryogenic Callus ◽  
Large Scale ◽  
Developmental Stages ◽  
Zygotic Embryos ◽  
Scale Production ◽  
Cedrus Libani ◽  
Hormone Levels ◽  
Significant Difference

Somatic embryogenesis offers a great potential for large-scale production of Cedrus libani, which is important not only as a forest tree, but also for the development of a timber industry. In an attempt to optimize conditions for embryogenic callus induction, we used zygotic embryos at different developmental stages as explants, compared different media, and used several hormone levels and combinations. Results indicated that post-cotyledonary immature embryos had highest induction efficiency. Four different media namely 1/2 MS, Durzan, Litvay's, and Von Arnold supplemented with similar hormone levels showed no significant difference in efficiency of callus induction. Induction frequencies of embryogenic callus from explants subjected to different hormone levels and combinations were dependent on the developmental stage of the explant.

LABORATORY STUDIES ON THE TOXICITY OF INSECTICIDES TO THE BERTHA ARMYWORM (MAMESTRA CONFIGURATA) (LEPIDOPTERA: NOCTUIDAE)

1975 ◽  
Vol 107 (8) ◽  
pp. 865-872 ◽  
Author(s):  
C. R. Harris ◽  
S.A. Turnbull
Keyword(s):  
Direct Contact ◽  
Developmental Stages ◽  
Contact Toxicity ◽  
Mamestra Configurata ◽  
Larval Stages ◽  
Large Numbers ◽  
Third Stage ◽  
History Of ◽  
Dual Objectives ◽  
Bertha Armyworm

AbstractThis study had dual objectives: to select a series of insecticides toxic to the bertha armyworm, Mamestra configurata (Walk.), and to determine susceptibility of the various developmental stages to insecticides. Pupae were collected from infested rapeseed fields in Alberta and a laboratory rearing procedure suitable for production of large numbers of insects was devised. The direct contact toxicity of 50 insecticides to third-stage larvae was assessed. Methomyl and DDT were included as standard insecticides. None of the experimental insecticides was as toxic as methomyl but about one half were more toxic than DDT. Tests with representative organochlorine, organophosphorus, and carbamate insecticides indicated that all caused rapid knockdown of third-stage larvae. There was no evidence of subsequent recovery. After the life history of the bertha armyworm under controlled environmental conditions was determined, tests were conducted to ascertain the susceptibility of the various developmental stages to methomyl, chlorpyrifos, leptophos, and methidathion. Eggs and first and second stage larvae were more susceptible to direct contact applications of the insecticides than were the later larval stages, pupae, and adults.

Disruption of Golgi structure and function in mammalian cells expressing a mutant dynamin

2000 ◽  
Vol 113 (11) ◽  
pp. 1993-2002 ◽  
Author(s):  
H. Cao ◽  
H.M. Thompson ◽  
E.W. Krueger ◽  
M.A. McNiven
Keyword(s):  
Mammalian Cells ◽  
Living Cells ◽  
Dominant Negative ◽  
Coated Vesicle ◽  
Large Numbers ◽  
Golgi Structure ◽  
And Function ◽  
Golgi Network ◽  
Mutant Cells

The large GTPase dynamin is a mechanoenzyme that participates in the scission of nascent vesicles from the plasma membrane. Recently, dynamin has been demonstrated to associate with the Golgi apparatus in mammalian cells by morphological and biochemical methods. Additional studies using a well characterized, cell-free assay have supported these findings by demonstrating a requirement for dynamin function in the formation of clathrin-coated, and non-clathrin-coated vesicles from the trans-Golgi network (TGN). In this study, we tested if dynamin participates in Golgi function in living cells through the expression of a dominant negative dynamin construct (K44A). Cells co-transfected to express this mutant dynamin and a GFP-tagged Golgi resident protein (TGN38) exhibit Golgi structures that are either compacted, vesiculated, or tubulated. Electron microscopy of these mutant cells revealed large numbers of Golgi stacks comprised of highly tubulated cisternae and an extraordinary number of coated vesicle buds. Cells expressing mutant dynamin and GFP-tagged VSVG demonstrated a marked retention (8- to 11-fold) of the nascent viral G-protein in the Golgi compared to control cells. These observations in living cells are consistent with previous morphological and in vitro studies demonstrating a role for dynamin in the formation of secretory vesicles from the TGN.

Secondary Industries for Tropical Africa

Africa ◽  
1943 ◽  
Vol 14 (4) ◽  
pp. 170-176 ◽  
Author(s):  
Theresa Cahan
Keyword(s):  
Large Scale ◽  
Good Effect ◽  
Scale Production ◽  
Tropical Africa ◽  
Large Numbers ◽  
Large Scale Production ◽  
Initial Stage ◽  
The One ◽  
Opening Paragraph ◽  
Laborious Method

Opening ParagraphThere is a tendency in some quarters to regard secondary industries as a panacea for all the economic ills of tropical Africa. It would be well at this initial stage to sound a note of warning. In the past, the industrialization of agricultural countries has had two results: one good, one bad. On the one hand, the establishment in a country of labour-saving machinery and large-scale production in place of the old laborious method of making things by hand has led to a rise in the general standard of living within the country in terms of real incomes. On the other hand, the drift of workers to the towns and the herding together of large numbers of people in factories resulted in the sum of social evils associated with the ‘dark satanic mills’: overcrowding, sweated labour, destitution, unemployment, and many more. The problem for tropical Africa to-day is to combine the maximum of the first and good effect with a minimum of the second evil.

scholarly journals Influence of cold storage on survival and fitness of Mastrus ridens an ectoparasitoid of codling moth

2015 ◽  
Vol 68 ◽  
pp. 197-203 ◽  
Author(s):  
W.R.M. Sandanayaka ◽  
V.A. Davis ◽  
A. Chhagan ◽  
P.G. Connolly ◽  
J.G. Charles
Keyword(s):  
Cold Storage ◽  
Developmental Stages ◽  
Larval Mortality ◽  
Codling Moth ◽  
Oviposition Period ◽  
Optimum Temperature ◽  
Large Numbers ◽  
High Larval Mortality ◽  
Mastrus Ridens

The effects of cold storage on eclosion longevity and fecundity of adults of Mastrus ridens an ectoparasitoid of codling moth were investigated by holding different lifestages (4 6 8 10 and 12 weeks) Cold storage of eggs for 4 weeks resulted in high larval mortality The development periods after cold storage decreased and the immature mortality increased with advancing developmental stages before cold storage The longevity of females decreased with increasing cold storage of prepupae and pupae Neither fecundity nor oviposition period of females emerging from the seven selected treatments was different from the control (females reared at optimum temperature) Results indicated that 7 to 10dayold their survival or quality of adulthood Application of this finding will help with supply of the large numbers of parasitoids needed during the release programme

scholarly journals Field evidence of intra- and interspecific predation in rock-pool corixids (Heteroptera, Corixidae)

1992 ◽  
Vol 3 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Irmeli Pajunen ◽  
V. Ilmari Pajunen
Keyword(s):  
High Mortality ◽  
Developmental Stages ◽  
Field Conditions ◽  
Considerable Proportion ◽  
Rock Pool ◽  
Field Evidence ◽  
Large Numbers ◽  
Interspecific Predation

Small corixid larvae were introduced into a rock-pool containing large numbers of later developmental stages. High mortality of small larvae was observed. A considerable proportion of larval carcases recovered each had triangular holes on its upper surface. Similar holes are characteristic of carcases recovered in laboratory cannibalism experiments. The dimensions of the punctures in field and laboratory samples match closely. Predatory interactions between large and small rock-pool corixid larvae are thus common in field conditions.

scholarly journals A new species of Micrurapteryx (Lepidoptera, Gracillariidae) feeding on Thermopsis lanceolata (Fabaceae) in southern Siberia and its hymenopterous parasitoids

ZooKeys ◽  
2021 ◽  
Vol 1061 ◽  
pp. 131-163
Author(s):  
Natalia I. Kirichenko ◽  
Evgeny N. Akulov ◽  
Paolo Triberti ◽  
Sergey A. Belokobylskij
Keyword(s):  
New Species ◽  
Developmental Stages ◽  
Dna Barcode ◽  
Reference Sequence ◽  
Large Numbers ◽  
Leaf Mining ◽  
Morphological Diagnosis ◽  
The Republic ◽  
First Time ◽  
A New Species

A new species of leaf-mining moth described here as Micrurapteryx baranchikovi Kirichenko, Akulov & Triberti, sp. nov. was detected in large numbers feeding on Thermopsis lanceolata (Fabaceae) in the Republic of Khakassia (Russia) in 2020. A morphological diagnosis of adults, bionomics and DNA barcoding data of the new species are provided. The developmental stages (larva, pupa, adult), male and female genitalia, as well as the leaf mines and the infestation plot in Khakassia are illustrated; the pest status of the new species in the studied region is discussed. Additionally, parasitism rate was estimated, the parasitoid wasps reared from pupae of the new species were identified (morphologically and genetically) and illustrated . Among them, one ichneumonid, Campoplex sp. aff. borealis (Zetterstedt) and two braconids, Agathis fuscipennis (Zetterstedt) and Illidops subversor (Tobias et Kotenko), are novel records for the Republic of Khakassia. Furthermore, they are all documented as parasitoids of Gracillariidae for the first time. The DNA barcode of A. fuscipennis is newly obtained and can be used as a reference sequence for species identification.

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