scholarly journals Efecto de la alternación de fuentes sanguíneas sobre la fecundidad y la fertilidad de Rhodnius prolixus Stal (Heteroptera: Reduviidae).

2009 ◽  
Vol 2 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Elis José Aldana ◽  
David Jácome ◽  
Eliézer Lizano

En este trabajo se evidencia que si el éxito reproductivo de Rhodnius prolixus Stal está relacionado a la fuente alimentaria, entonces las necesidades biológicas del insecto son satisfechas en modos diferentes según el tipo de alternancia entre dichas fuentes de alimentación; tales diferencias son reveladas mediante los cambios en fertilidad y fecundidad del insecto. Se realizaron nueve alternancias, en cada una se suministraron dos alimentaciones, en unas se alternó la fuente de alimentación y en los controles se suministraron dos alimentaciones con la misma fuente. Las fuentes alimentarias fueron paloma, gallina y humano, esta última mediante un aparato de alimentación artificial; estas fuentes se escogieron en el supuesto que son fuentes alimentarias encontradas en los ecotopos silvestre, peri-domicilio y domicilio respectivamente. En todos los tipos de alternancia se encontró una relación lineal entre la fecundidad y el tiempo de oviposición, que la relación entre cantidad de sangre ingerida y la fecundidad varían, que la tasa de fecundidad aumenta en la segunda alimentación respecto a la primera y que la fertilidad fue superior al 95 %.   Effects of alternating blood sources on fecundity and fertility of Rhodnius prolixus Stal (Heteroptera: Reduviidae) In this work it is argued that if the reproductive parameters of Rhodnius prolixus Stal are related to the blood source upon which it feeds, then the insects biological needs must be satisfied in different ways by the alternation between blood sources, reveled through changes in the fecundity and fertility of individuals of this insect species. Nine experiments were conducted, each one consisting of two feedings, in which the blood source were either alternated or remained the same. The meal sources used were pigeon, hen and human blood, selected according to the resources found in the sylvatic, peri-domestic and domestic ecotopes respectively. It was found that the quantity of blood ingested and the fecundity were differents according to alternation of blood sources offered in each meal. A linear relation was found between the fecundity and the time of oviposition in every alternation of meal sources. On the other hand there was a slope increase in the second feeding of every experiment. The fertility was above 95% in each experiment.   Efeito da alternação de fontes sanguíneas sobre fecundidade e fertilidade de Rhodnius prolixus Stal (Heteroptera Reduviidae) Neste trabalho evidencia-se que o sucesso reprodutivo de Rhodnius prolixus Stal esta relacionado à fonte alimentícia, então as necessidades biológicas do inseto são satisfeitas em modos diferentes segundo o tipo de alternância entre ditas fontes de alimentação; tais diferenças são reveladas mediante mudanças em fertilidade e fecundidade do inseto. Realizaram-se nove testes, em cada um foram subministradas duas alimentações, sendo que em alguns foi alternada a fonte de alimentação e nos controles foram subministradas duas alimentações com a mesma fonte. As fontes alimentícias foram pomba, galinha e humano, esta ultima mediante um aparelho de alimentação artificial; estas fontes foram escolhidas no suposto que são fontes alimentícias encontradas nos ecótopos silvestres, peridomicilio e domicilio respectivamente. Em todos os tipos de alternância foi encontrada uma relação lineal entre a fecundidade e o tempo de oviposição, que a relação entre quantidade de sangue ingerida e a fecundidade variam, que a taxa de fecundidade aumenta na segunda alimentação respeito à primeira e que a fertilidade foi superior ao 95%.

1955 ◽  
Vol 32 (4) ◽  
pp. 649-663
Author(s):  
V. B. WIGGLESWORTH

Moulting in Rhodnius is greatly delayed by the injection of trypan blue, indian ink or iron saccharate, which are taken up by the phagocytic blood cells (amoebocytes). This delay occurs only when the injections are made during the first 3 days after feeding, not on the fourth day or later. On the fourth day after feeding the amoebocytes become filled with secretory vacuoles which restrict the uptake of indian ink or iron saccharate. When the amoebocytes are blocked by such injections within a day after feeding, the secretory activity of the thoracic gland is greatly reduced. This is proved histologically and experimentally. On the other hand, moulting induced by implantation of a fully active thoracic gland is not delayed by blocking the haemocytes. It is therefore concluded that some substance secreted by the haemocytes is necessary for the full activity of the thoracic glands. The crystalline hormone isolated by Butenandt & Karlson from the silkworm will induce moulting in the decapitated Rhodnius larva and in the isolated abdomen. Its action is not inhibited or delayed by the injection of indian ink or iron saccharate. This supports the conclusion that it is the product of the thoracic gland. Sublethal high temperatures will inhibit moulting in Rhodnius even when it is provided with abundant hormone by injection of the crystalline material or by joining in parabiosis with a moulting larva.


1974 ◽  
Vol 52 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Ruth Perassi ◽  
José A. Cerisola

The antigenic composition of haemolymph from some reduviids was studied by means of immunochemical methods.No differences were detected between haemolymph from Triatoma infestans and Triatoma platensis. On the other hand, important qualitative and quantitative differences were observed in the antigenic composition of the haemolymph from Triatoma phyllosoma pallidipenis, Triatoma spinolai, Triatoma rubrovaria, Triatoma vitticeps, Rhodnius prolixus, and Rhodnius neglectus with respect to Triatoma infestans.


1959 ◽  
Vol 110 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Frank A. Kapral ◽  
Mehdi Gh. Shayegani

A tissue culture procedure is described which permits the quantitative evaluation of the intracellular survival of staphylococci within leucocytes. Staphylococcus aureus survived, but did not multiply, within neutrophils and monocytes of normal rabbits. The same was true of normal human blood leucocytes. Staphylococcus albus on the other hand was destroyed by these cells under the same conditions. Rat monocytes destroyed S. aureus and S. albus with equal facility. Although most experiments were carried out in the presence of 50 µg. streptomycin/ml., similar results were obtained without the use of this antibiotic. The applications of the tissue culture procedure with regard to studies on virulence and immunity in staphylococcal disease are discussed.


2016 ◽  
Vol 09 (02) ◽  
pp. 1650012 ◽  
Author(s):  
K. Karpienko ◽  
M. Gnyba ◽  
D. Milewska ◽  
M. S. Wróbel ◽  
M. Jędrzejewska-Szczerska

Preclinical research of biomedical optoelectronic devices is often performed with the use of blood phantoms — a simplified physical model of blood. The aim of this study is the comparison and distinction between blood phantoms as well as whole human blood measurements. We show how the use of such phantoms may influence the incorrect interpretation of measured signal. On the other hand, we highlight how the use of blood phantoms enables to investigate the phenomena that otherwise are almost impossible to be noticed.


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


Author(s):  
A. V. Crewe

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.


Author(s):  
K.H. Westmacott

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.


2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.


Author(s):  
Stefan Krause ◽  
Markus Appel

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.


2019 ◽  
Vol 50 (2) ◽  
pp. 80-93
Author(s):  
Jort de Vreeze ◽  
Christina Matschke

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.


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