Malaria parasites enhance blood-feeding of their naturally infected vector Anopheles punctulatus

Parasitology ◽  
1996 ◽  
Vol 113 (2) ◽  
pp. 105-109 ◽  
Author(s):  
J. C. Koella ◽  
M. J. Packer
Keyword(s):  
Plasmodium Falciparum ◽  
Papua New Guinea ◽  
Natural Population ◽  
Feeding Behaviour ◽  
Blood Feeding ◽  
The Other ◽  
Malaria Parasites ◽  
Anopheles Punctulatus ◽  
The Relationship ◽  
Natural Situation

SUMMARYWe investigated the blood-feeding behaviour of a natural population of the human-feeding mosquito Anopheles punctulatus in Iguruwe, Papua New Guinea. In particular we investigated the relationship between the mosquitoes' blood-feeding behaviour and their infection by the malaria parasites Plasmodium falciparum and P. vivax. Female mosquitoes were caught at 4 times of the night, the amount of blood they had obtained was measured and their status of infection was evaluated. Among uninfected mosquitoes the bloodmeal size steadily increased through the night, possibly because they were progressively less likely to be disturbed by human activity as the night drew on. Infected mosquitoes, on the other hand, tended to feed maximally at all times of the night. This suggests that infected mosquitoes were more tenacious in their blood-feeding behaviour, being either less readily disturbed during a bout of feeding (and thus feeding longer) or more likely to return to continue their feed following disturbance (and thus feeding several times). Either change would increase the parasites' rate of transmission. We conclude that in this natural situation the two species of malaria parasites modified the mosquitoes' behaviour with the effect of increasing their own transmission.

scholarly journals The Impact of Gravidity, Symptomatology and Timing of Infection on Placental Malaria

2020 ◽  
Author(s):  
Erin E Tran ◽  
Morgan Cheeks ◽  
Abel Kakuru ◽  
Mary K Muhindo ◽  
Paul Natureeba ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Blood Smear ◽  
Placental Malaria ◽  
Fold Increase ◽  
Preventive Therapy ◽  
Malaria Parasites ◽  
Increased Risk ◽  
Placental Blood ◽  
The Impact ◽  
The Relationship

Abstract Background : Placental malaria is associated with increased risk of adverse perinatal outcomes. While primigravidity has been reported as a risk factor for placental malaria, little is known regarding the relationship between gravidity, symptomatology and timing of Plasmodium falciparum infection and the development of placental malaria. Methods : Our aim was to investigate the relationship between the development of placental malaria and gravidity, timing of infection, and presence of symptoms. This is a secondary analysis of data from a double-blind randomized control trial of intermittent preventive therapy during pregnancy in Uganda. Women were enrolled from 12 to 20 weeks gestation and followed through delivery. Exposure to malaria parasites was defined as symptomatic (fever with positive blood smear) or asymptomatic (based on molecular detection of parasitemia done routinely every 4 weeks). The primary outcome was placental malaria diagnosed by histopathology, placental blood smear, and/or placental blood loop-mediated isothermal amplification. We performed subgroup analysis based on the presence of symptomatic malaria, gravidity, and timing of infection. Results : Of the 228 patients with documented maternal infection with malaria parasites during pregnancy, 101 (44.3%) had placental malaria. Primigravidity was strongly associated with placental malaria (aOR 8.90, 95% CI 4.34-18.2, p<0.001), and each episode of malaria was associated with over a 2-fold increase in placental malaria (aOR 2.35, 95% CI 1.69-3.26, p<0.001). Among multigravid women, the odds of placental malaria increased by 14% with each advancing week of gestation at first documented infection (aOR 1.14, 95% CI 1.02-1.27, p=0.02). When stratified by the presence of symptoms, primigravidity was only associated with placental malaria in asymptomatic women, who had a 12-fold increase in the odds of placental malaria (aOR 12.19, 95% CI 5.23-28.43, p<0.001). Conclusions : Total number of Plasmodium falciparum infections in pregnancy is a significant predictor of placental malaria. The importance of timing of infection on the development of placental malaria varies based on gravidity. In primigravidas, earlier asymptomatic infections were associated with placental malaria, whereas in multigravidas, parasitemias detected later in gestation were associated with placental malaria. Earlier initiation of an effective intermittent preventive therapy may help to prevent placental malaria and improve birth outcomes, particularly in primigravid women.

Characterisation of Behavioural Types in Pigs: The Relationship Between Feeding Behaviour and Social Rank

1993 ◽  
Vol 1993 ◽  
pp. 83-83
Author(s):  
H.A.M. Spoolder ◽  
J.A. Burbidge ◽  
A.B. Lawrence ◽  
P.H. Simmins ◽  
S.A. Edwards ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Food Restriction ◽  
Social Rank ◽  
Individual Characteristics ◽  
The Other ◽  
Abnormal Behaviour ◽  
Intensive Farming ◽  
Feeding Motivation ◽  
Behavioural Types ◽  
The Relationship

In intensive farming, it is Important to remember that each individual animal has its own needs (Hughes and Duncan, 1988). In pigs, close confinement and food restriction can result in the development of abnormal behaviour. Terlouw et al. (1990) suggest that an individual's temperament may influence the development of such behaviour and therefore how a pig copes with environmental stress. Individual differences in behaviour are consistent and measurable (e.g. Lyons et al.. 1988). By determining an animal's temperament using a characteristic profile, it may it may be possible to predict the response of a temperament “type” to certain conditions.This study is part of a larger project concerned with the effects of housing and feed level on the development of behaviours in group-housed gilts. All the pigs entered a series of tests to measure individual characteristics prior to the main experiment. Two of the tests, one measuring feeding motivation and the other social behaviour, are compared here.

scholarly journals The impact of gravidity, symptomatology and timing of infection on placental malaria

2020 ◽  
Author(s):  
Erin E Tran ◽  
Morgan Cheeks ◽  
Abel Kakuru ◽  
Mary K Muhindo ◽  
Paul Natureeba ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Blood Smear ◽  
Placental Malaria ◽  
Fold Increase ◽  
Preventive Therapy ◽  
Malaria Parasites ◽  
Increased Risk ◽  
Placental Blood ◽  
The Impact ◽  
The Relationship

Abstract Background Placental malaria is associated with increased risk of adverse perinatal outcomes. While primigravidity has been reported as a risk factor for placental malaria, little is known regarding the relationship between gravidity, symptomatology and timing of Plasmodium falciparum infection and the development of placental malaria. Methods The aim of this study was to investigate the relationship between the development of placental malaria and gravidity, timing of infection, and presence of symptoms. This is a secondary analysis of data from a double-blind randomized control trial of intermittent preventive therapy during pregnancy in Uganda. Women were enrolled from 12 to 20 weeks gestation and followed through delivery. Exposure to malaria parasites was defined as symptomatic (fever with positive blood smear) or asymptomatic (based on molecular detection of parasitemia done routinely every 4 weeks). The primary outcome was placental malaria diagnosed by histopathology, placental blood smear, and/or placental blood loop-mediated isothermal amplification. Multivariate analyses were performed using logistic regression models. Subgroup analysis was performed based on the presence of symptomatic malaria, gravidity, and timing of infection. Results Of the 228 patients with documented maternal infection with malaria parasites during pregnancy, 101 (44.3%) had placental malaria. Primigravidity was strongly associated with placental malaria (aOR 8.90, 95% CI 4.34-18.2, p<0.001), and each episode of malaria was associated with over a 2-fold increase in placental malaria (aOR 2.35, 95% CI 1.69-3.26, p<0.001). Among multigravid women, the odds of placental malaria increased by 14% with each advancing week of gestation at first documented infection (aOR 1.14, 95% CI 1.02-1.27, p=0.02). When stratified by the presence of symptoms, primigravidity was only associated with placental malaria in asymptomatic women, who had a 12-fold increase in the odds of placental malaria (aOR 12.19, 95% CI 5.23-28.43, p<0.001). Conclusions Total number of Plasmodium falciparum infections in pregnancy is a significant predictor of placental malaria. The importance of timing of infection on the development of placental malaria varies based on gravidity. In primigravidas, earlier asymptomatic infections were more frequently identified in those with placental malaria, whereas in multigravidas, parasitemias detected later in gestation were associated with placental malaria. Earlier initiation of an effective intermittent preventive therapy may help to prevent placental malaria and improve birth outcomes, particularly in primigravid women.

Blood-feeding and resting behaviour in theAnopheles punctulatusDönitz complex (Diptera: Culicidae) from coastal Papua New Guinea

1985 ◽  
Vol 75 (3) ◽  
pp. 463-476 ◽  
Author(s):  
J. D Charlwood ◽  
H. Dagoro ◽  
R. Paru
Keyword(s):  
Papua New Guinea ◽  
Electrophoretic Pattern ◽  
New Guinea ◽  
Blood Feeding ◽  
Resting Behaviour ◽  
Mark Release Recapture ◽  
Tests Of Association ◽  
Allelic Type ◽  
Anopheles Punctulatus ◽  
Outdoor Resting

AbstractSamples of engorged outdoor-resting females of the complex ofAnopheles punctulatusDönitz, primarilyA. farautiLaveran, were obtained from villages in Madang Province, Papua New Guinea, in 1981–83 and their blood-meal sources identified. The proportion of the population feeding on man varied considerably from village to village according to the number of animals, particularly pigs, available as alternative hosts. Using a unique host in a mark–release–recapture experiment, the distance flown by engorged females ofA. farautiwas found to be generally less than 50 m. In one village, the gonotrophic age of a subsample of 1523 females ofA. farautiwas obtained and in 503 of these the electrophoretic pattern of the enzyme phosphoglucomutase (PGM) determined. Tests of association were per formed on the data. However, no significant relationship was found between host source, gonotrophic age and allelic type of PGM. Thus, separate subpopulations ofA. farautiwere not identified within this village. The relevance of the results to the epidemiology of malaria is discussed.

The effects of sublethal doses of hexaflumuron on the feeding behaviour of mosquitoes (Diptera: Culicidae)

1992 ◽  
Vol 82 (4) ◽  
pp. 535-538 ◽  
Author(s):  
V. Vasuki
Keyword(s):  
Aedes Aegypti ◽  
Feeding Behaviour ◽  
Anopheles Stephensi ◽  
Feeding Activity ◽  
Sublethal Effect ◽  
Blood Feeding ◽  
Insect Growth Regulator ◽  
The Other ◽  
Lower Blood ◽  
Sublethal Doses

AbstractThis paper presents the first report on the sublethal effect of an insect growth regulator (IGR), hexaflumuron, on the feeding behaviour of vector mosquitoes, Culex quinquefasciatus Say, Aedes aegypti (Linnaeus) and Anopheles stephensi Liston. Percentage engorgement and feeding behaviour of the adults of the three species emerged after sublethal exposures at the larval and pupal stages were markedly affected. Depression in blood feeding was significantly higher in Aedes aegypti with lower blood engorgement ratio. The proportion of females that failed to take a blood meal was higher in A. aegypti (30.2%) than in the other species when pupae had been exposed to 0.05 mg/1 hexaflumuron. Depression in blood feeding was probably due to abnormalities in the functioning of the mouth parts and feeding behaviour. No adverse effect on the feeding activity was noticed in the F1 generation of the treated species.

The Relationship Between Suicidal Thinking and Dating Violence in a Sample of Adolescent Abortion Patients

Crisis ◽  
2011 ◽  
Vol 32 (5) ◽  
pp. 246-253 ◽  
Author(s):  
Gretchen E. Ely ◽  
William R. Nugent ◽  
Julie Cerel ◽  
Mholi Vimbba
Keyword(s):  
Unintended Pregnancy ◽  
Dating Violence ◽  
Young Women ◽  
Psychosocial Problems ◽  
The Other ◽  
Assessment Scale ◽  
Adolescent Dating Violence ◽  
Adolescent Relationships ◽  
Suicidal Thinking ◽  
The Relationship

Background: The relationship between suicidal thinking and adolescent dating violence has not been previously explored in a sample of adolescent abortion patients. Aims: This paper highlights a study where the relationship between dating violence and severity of suicidal thinking was examined in a sample of 120 young women ages 14–21 seeking to terminate an unintended pregnancy. Methods: The Multidimensional Adolescent Assessment Scale and the Conflict in Adolescent Relationships Scale was used to gather information about psychosocial problems and dating violence so that the relationship between the two problems could be examined, while controlling for the other psychosocial problems. Results: The results suggest that dating violence was related to severity of suicidal thinking, and that the magnitude of this relationship was moderated by the severity of problems with aggression. Conclusions: Specifically, as the severity of participant’s general problems with aggression increased, the magnitude of the relationship between dating violence and severity of suicidal thinking increased. Limitations of the study and implications for practice are discussed.

Emotional Impact Feedback Changes How We Remember Negative Autobiographical Experiences

2010 ◽  
Vol 57 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange
Keyword(s):  
Well Being ◽  
The Other ◽  
Personal Perspective ◽  
Emotional Impact ◽  
Potential Mechanism ◽  
Negative Experiences ◽  
Negative Memory ◽  
The Relationship ◽  
Negative Memories ◽  
Over Time

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.

Haematocrit: Relationships with Blood Lipids, Blood Pressure and other Cardiovascular Risk Factors

1994 ◽  
Vol 72 (01) ◽  
pp. 058-064 ◽  
Author(s):  
Goya Wannamethee ◽  
A Gerald Shaper
Keyword(s):  
Physical Activity ◽  
Risk Factors ◽  
Blood Pressure ◽  
Body Mass Index ◽  
Cardiovascular Risk ◽  
Cardiovascular Risk Factors ◽  
Alcohol Intake ◽  
Blood Lipids ◽  
The Other ◽  
The Relationship

SummaryThe relationship between haematocrit and cardiovascular risk factors, particularly blood pressure and blood lipids, has been examined in detail in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns. The analyses are restricted to the 5494 men free of any evidence of ischaemic heart disease at screening.Smoking, body mass index, physical activity, alcohol intake and lung function (FEV1) were factors strongly associated with haematocrit levels independent of each other. Age showed a significant but small independent association with haematocrit. Non-manual workers had slightly higher haematocrit levels than manual workers; this difference increased considerably and became significant after adjustment for the other risk factors. Diabetics showed significantly lower levels of haematocrit than non-diabetics. In the univariate analysis, haematocrit was significantly associated with total serum protein (r = 0*18), cholesterol (r = 0.16), triglyceride (r = 0.15), diastolic blood pressure (r = 0.17) and heart rate (r = 0.14); all at p <0.0001. A weaker but significant association was seen with systolic blood pressure (r = 0.09, p <0.001). These relationships remained significant even after adjustment for age, smoking, body mass index, physical activity, alcohol intake, lung function, presence of diabetes, social class and for each of the other biological variables; the relationship with systolic blood pressure was considerably weakened. No association was seen with blood glucose and HDL-cholesterol. This study has shown significant associations between several lifestyle characteristics and the haematocrit and supports the findings of a significant relationship between the haematocrit and blood lipids and blood pressure. It emphasises the role of the haematocrit in assessing the risk of ischaemic heart disease and stroke in individuals, and the need to take haematocrit levels into account in determining the importance of other cardiovascular risk factors.

Structuralism as a Pamphlet (On the Book by E. Reinert “How Rich CountriesGot Rich... And Why Poor Countries Stay Poor”. 2nd ed.)

2014 ◽  
pp. 147-153
Author(s):  
P. Orekhovsky
Keyword(s):  
Economic Theory ◽  
Economic Development ◽  
Structural Analysis ◽  
Increasing Returns ◽  
The Other ◽  
Static Theory ◽  
Poor Countries ◽  
Historical School ◽  
Socio Economic Development ◽  
The Relationship

The review outlines the connection between E. Reinert’s book and the tradition of structural analysis. The latter allows for the heterogeneity of industries and sectors of the economy, as well as for the effects of increasing and decreasing returns. Unlike the static theory of international trade inherited from the Ricardian analysis of comparative advantage, this approach helps identify the relationship between trade, production, income and population growth. Reinert rehabilitates the “other canon” of economic theory associated with the mercantilist tradition, F. Liszt and the German historical school, as well as a reconside ration of A. Marshall’s analysis of increasing returns. Empirical illustrations given in the book reveal clear parallels with the path of Russian socio-economic development in the last twenty years.

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