Leptomonas capsularis n.sp. and other flagellates parasitic in Cletus ochraceus (Hemiptera)

Parasitology ◽  
1951 ◽  
Vol 41 (1-2) ◽  
pp. 128-133 ◽  
Author(s):  
Alfred J. Gibbs

It has recently been shown (Gibbs, 1950), in the case of Crithidia familiaris, parasitic in the digestive tract of Cenaeus carnifex (Hemiptera), that resistant, infective bodies are produced in the hind-gut by an unequal division leptomonads. One of the two daughter-cells fails to grow a flagellum but remains attachedm, by a thread, to the flagellum of the other. Laterm the non-flagellate body becomes more compact in form and finnaly becomes invested in a tough, protective periplast. It then becomes detached from the parent flagellate. Large numbers of these bodies are scattered in the faeces, and it has been shown that they are capable of infecting fresh insects when ingested. The purpose of the attachment of the non-motile, immature infective body to an active flagellate is apparently to prevent its being prematurely swept from the gut.

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Silvia Rizzi ◽  
Maarten J. Wensink ◽  
Rune Lindahl-Jacobsen ◽  
Lu Tian ◽  
Ying Lu ◽  
...  

Abstract Objective With the ongoing COVID-19 pandemic, large numbers of people will receive one of the several medications proposed to treat COVID-19, including patients of reproductive age. Given that some medications have shown adverse effects on sperm quality, there might be a transgenerational concern. We aim at examining the association between drugs proposed to treat COVID-19 when taken by the father around conception and any pre-term birth or major birth defects in offspring in a nation-wide cohort study using Danish registry data. Offspring whose father filled at least one prescription of the following medications in the 3 months preceding conception were considered exposed: chloroquine, hydroxychloroquine, losartan, azithromycin, naproxen, dexamethasone and prednisone. Results For azithromycin and naproxen, large numbers of offspring were exposed (> 1800 offspring), and we found no association with adverse birth outcomes. For chloroquine, losartan and dexamethasone, exposure was intermediate (~ 900 offspring), and there was no statistically significant association with birth defects. For hydroxychloroquine and prednisone, exposure was limited (< 300 offspring). Our evidence suggests that azithromycin and naproxen are safe with respect to pre-term birth and birth defects. For the other drugs investigated larger exposures are needed for conclusive statements.


2011 ◽  
Vol 85 (2) ◽  
pp. 234-249 ◽  
Author(s):  
Dirk Fuchs ◽  
Neal Larson

Morphologic analyses of a large collection of coleoid cephalopods from the Lebanese Upper Cretaceous yielded a much higher diversity than previously assumed and revealed numerous extraordinarily well-preserved, soft-part characters. An analysis of the Prototeuthidina, a gladius-bearing group with a slender torpedo-shaped body, revealed two species:Dorateuthis syriacaandBoreopeltis smithin. sp. Previously unknown soft-part characters, such as the digestive tract, the gills, and the cephalic cartilage considerably improved our knowledge ofD. syriaca.Since none of the investigated specimens show more than eight arms, similarities with modern squids are regarded as superficial.Boreopeltis smithin. sp. is erected on the basis of its comparatively wideParaplesioteuthis-like gladius. The latter species represents the first unambiguous record of this genus in Upper Cretaceous deposits. Phylogenetic analyses indicate that the prototeuthidid clade consists of two lineages. The plesioteuthidid lineage originates from early JurassicParaplesioteuthisand leads toPlesioteuthisandDorateuthis.The other lineage is morphologically more conservative and leads toBoreopeltis.


2021 ◽  
Vol 104 (8) ◽  
pp. 1389-1392

To summarize the recent trials and studies of the role of beta-blocker on the treatment for cancer patients treated with anthracycline to decrease morbidity and mortality rate. Good management of cancer will result in large numbers of cancer survivors. On the other hand, cancer therapy also has side effects, one of which is cardiotoxicity. Cardiotoxicity could reduce therapy effectiveness, hence, increase disease progression and mortality rate. Anthracyclines is one of the chemotherapy agents with cardiotoxicity as a side effect. Beta-blocker has the ability to reduce cardiotoxicity due to anthracyclines usage. Keywords: Beta-blocker; Cardiotoxicity; Anthracyclines


1995 ◽  
Vol 1995 ◽  
pp. 164-164
Author(s):  
B. McLean ◽  
A. Afzalzadeh ◽  
L. Bates ◽  
R.W. Mayes ◽  
F.D.DeB. Hovell

It is well established that the intake and digestibility of roughages by ruminants is positively correlated with rate of passage (ARC, 1980), presumably to enable as complete a microbial degradation of the poorer roughages as possible. On the other hand hind gut fermenters such as horses have been thought to have adopted the alternative strategy of using a high rate of passage to ‘cream’ off the rapidly degradable material of poor quality roughages so as to maintain adequate nutrient intakes. Surprisingly, there are remarkably few actual comparisons between ruminants and hindgut fermenters in the literature. Traditionally dried roughages (hay) and cereal and ‘by-product concentrates’ have been used as horse feeds (grains, brans sugar beet pulp). Recently there has been more interest in the use of silages with horses (eg Smoulders and Hobiers, 1988). However the information as to the utilisation of silages by horses is limited.


2018 ◽  
Vol 51 (2) ◽  
pp. 85-90 ◽  
Author(s):  
H.F. Abou-Shaara ◽  
M.E. Ahmad ◽  
J. Háva

Abstract Honey bees are very valuable to human. These social insects contribute in the pollination of many crops. Also, the products from honey bee colonies have many nutritional and medicinal benefits. Thus, keeping honey bees are very valuable and can be considered as source of income to many families. There are many diseases and pests that attack honey bee colonies. The pests attack bee colonies include: hornets, wax moths, bee-eater birds, and beetles. Such challenges can impact the survival and productivity of honey bee colonies. In this study, some beetle species belong to Fam. Nitidulidae, Dermestidae and Mycetophagidae were detected in honey bee colonies in Egypt, during spring. Despite the presence of many beetle species in the agricultural environment, only few species preferred the invasion of the colonies for feeding. These beetles do not attack stages of honey bees. They only feed on stored pollen or bee bread, especially those fallen on the bottom of the beehives. This is an alarm to follow the feeding behavior and distribution of these beetles. These beetles’ species can be considered as potential pests to weak honey bee colonies, housed in old or damaged beehives. The presence of large numbers of these beetles in weak colonies may disturb the activities of the bees and may passively impact the survival of the colonies. Listing these beetles is very important to better understanding the interaction between honey bees and beetles. On the other side, small hive beetles were not detected in the colonies. These beetles are currently one of the major problems facing honey bees in different parts of the world. This study confirms the absence of small hive beetles from Egypt.


2010 ◽  
Vol 192 (16) ◽  
pp. 4134-4142 ◽  
Author(s):  
Jennifer R. Juarez ◽  
William Margolin

ABSTRACT The Min system regulates the positioning of the cell division site in many bacteria. In Escherichia coli, MinD migrates rapidly from one cell pole to the other. In conjunction with MinC, MinD helps to prevent unwanted FtsZ rings from assembling at the poles and to stabilize their positioning at midcell. Using time-lapse microscopy of growing and dividing cells expressing a gfp-minD fusion, we show that green fluorescent protein (GFP)-MinD often paused at midcell in addition to at the poles, and the frequency of midcell pausing increased as cells grew longer and cell division approached. At later stages of septum formation, GFP-MinD often paused specifically on only one side of the septum, followed by migration to the other side of the septum or to a cell pole. About the time of septum closure, this irregular pattern often switched to a transient double pole-to-pole oscillation in the daughter cells, which ultimately became a stable double oscillation. The splitting of a single MinD zone into two depends on the developing septum and is a potential mechanism to explain how MinD is distributed equitably to both daughter cells. Septal pausing of GFP-MinD did not require MinC, suggesting that MinC-FtsZ interactions do not drive MinD-septal interactions, and instead MinD recognizes a specific geometric, lipid, and/or protein target at the developing septum. Finally, we observed regular end-to-end oscillation over very short distances along the long axes of minicells, supporting the importance of geometry in MinD localization.


Development ◽  
1993 ◽  
Vol 118 (4) ◽  
pp. 1267-1277 ◽  
Author(s):  
B. Goldstein

The gut of C. elegans derives from all the progeny of the E blastomere, a cell of the eight cell stage. Previous work has shown that gut specification requires an induction during the four cell stage (Goldstein, B. (1992) Nature 357, 255–257). Blastomere isolation and recombination experiments were done to determine which parts of the embryo can respond to gut induction. Normally only the posterior side of the EMS blastomere contacts the inducing cell, P2. When P2 was instead placed in a random position on an isolated EMS, gut consistently differentiated from the daughter of EMS contacting P2, indicating that any side of EMS can respond to gut induction. Additionally, moving P2 around to the opposite side of EMS in an otherwise intact embryo caused EMS's two daughter cells to switch lineage timings, and gut to differentiate from the descendents of what normally would be the MS blastomere. The other cells of the four cell stage, ABa, ABp, and P2, did not form gut when placed in contact with the inducer. To determine whether any other inductions are involved in gut specification, timed blastomere isolations were done at the two and eight cell stages. In the absence of cell contact at the two cell stage, segregation of gut fate proceeded normally at both the two and four cell stages. Gut fate also segregated properly in the absence of cell contact at the eight cell stage. A model is presented for the roles of lineage-dependent mechanisms and cell interactions in establishing gut fate in the E lineage.


Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 53-72
Author(s):  
C. F. Graham ◽  
Z. A. Deussen

The cell lineage of the mouse was studied from the 2-cell stage to the blastocyst. Lineage to the 8-cell stage was followed under the microscope. Each cell from the 2-cell stage divided to form two daughter cells which remained attached. Subsequently, these two daughters each produced two descendants; one of these descendants regularly lay deep in the structure of the embryo while the other was peripheral. Lineage to the blastocyst was followed by injecting oil drops into cells at the 8-cell stage, and then following the segregation of these drops into the inner cell mass and trophectoderm. Between the 8-cell stage and the blastocyst, the deep cells contributed more frequently to the inner cell mass than did the peripheral cells.


Author(s):  
Jaideep Prabhu

The global economy will face significant challenges over the next few decades. On the one hand, it must meet the needs of 7 billion consumers (growing to 9 billion by 2050), including the currently unmet basic needs of large numbers in developing countries in areas such as food, energy, housing and health. On the other hand, it must achieve this growth without exceeding the resources available on the planet or causing environmental devastation. This paper argues that such change is possible through a systemic shift to a frugal economy that involves radical, frugal innovation across sectors. Such a transformation will involve the participation of large and small firms, consumers and governments alike. The paper introduces the notion of frugal innovation—the creation of faster, better and cheaper solutions for more people that employ minimal resources—and discusses strategies and examples of such change already taking place in core sectors like manufacturing, food, automotive and energy in developing and developed economies. It also outlines the role of the interaction between large and small firms as well as between firms and consumers in making change possible, as well as the role of governments in driving change where market mechanisms alone will not suffice. This article is part of the themed issue ‘Material demand reduction’.


Parasitology ◽  
1929 ◽  
Vol 21 (1-2) ◽  
pp. 189-219 ◽  
Author(s):  
W. F. Harper

A large number of fresh-water Invertebrates has been examined and the parasites obtained from them include examples of the commoner groups to be met with in any area surveyed. Six larval Trematodes have been described in detail, and by means of direct animal experiment two of them have been definitely related to known adults. Of these two one is the larva of Notocotylus seineti Fuhr., and is doubtfully Cercaria monostomi v. Linst., while the other is the larva of Echinoparyphium recurvatum v. Linst., and is described here in detail for the first time. The four xiphidiocercariae described are new. Data relating to the activity, duration of free life, and process of encystment of cercariae within the bodies of secondary intermediate hosts is also given.Effect of the parasite on the host. The disruption of the tissues brought about by the presence of sporocysts or rediae in the liver of a mollusc injures the host, and in many cases brings about its death. The gonads also are often attacked and completely destroyed. This latter feature of parasitic castration has been observed by Giard (1888) among certain species of Limnaea, Planorbis and Paludina attacked by sporocysts. Brown (1926) states that the gonads are rarely infected. As regards the encysted stages of cercariae these appear to do very little harm to their hosts even when present in large numbers. These observations are in agreement with those of Lebour (1912) for the sporocyst, rediae, and encysted stages of marine Trematodes.Double infection. I have found no instance of a double infection among the species described. In the literature, several records show the parasitism of two or more species of cercariae, within one and the same host. The occurrence of two species is most commonly met with, and as a rule one is in predominance. Sewell (1922) states that double infection is not common in India. Faust (1917), on the other hand, has found as many as four trematode species within the same host individual (Planorbis trivolis). Hesse (1923) states that “every large Limnaea peregra examined was heavily infected with sporocysts of either of the two species, but it was rare to find both together.” Brown (1926) in the neighbourhood of Birmingham has found three examples of associated xiphidiocercariae and furcocercariae, one example of xiphidiocercariae and echinostome cercariae, and two examples of echinostome cercaria, all from Limnaea stagnalis L.


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