Parasitism, immune response, and egg production of the spearhead bluet (Coenagrion hastulatum) damselfly

2017 ◽  
Vol 95 (5) ◽  
pp. 367-372
Author(s):  
Kari M. Kaunisto ◽  
Pipsa Kaunisto ◽  
Jaakko J. Ilvonen ◽  
Jukka Suhonen

Theoretical models predict that parasites reduce reproductive success of their hosts, but very few empirical studies have given support to this. Using the spearhead bluet (Coenagrion hastulatum (Charpentier, 1825)) damselfly, we tested how immune response, wing length, and the number of both endo- and ecto-parasites affect egg production of host damselflies. The study was conducted with four different populations in southwest Finland. We found a negative association between endoparasitic gregarines and number of host eggs. Furthermore, immune response increased with the number of water mites, but decreased with the number of eggs. Contrary to previous studies with other damselfly species, the number of ectoparasitic water mites did not affect the number of eggs. Moreover, wing length, used as an indicator of individual size, was not associated with egg numbers. The negative effect of gregarine parasites on egg numbers is likely to affect the composition of host populations, i.e., damselflies that show higher resistance to these endoparasites will have more of their offspring represented in subsequent generations. In future, more experimental research on the varying effects of different parasite species on the number of eggs is needed.

2018 ◽  
Vol 45 (4) ◽  
pp. 339-357
Author(s):  
Talknice Saungweme ◽  
Nicholas M. Odhiambo

This article provides a detailed survey of existing theoretical and empirical literature on the impact of public debt on economic growth in both developing and developed economies. The aim of the article is to add to the existing debate on the relationship between public debt and economic growth in world economies. The survey finds diverse and, in some cases, inconsistent evidence on the relative impact of public debt on economic growth. Although the majority of the surveyed literature supports the negative effect of public debt on economic growth, several other studies have found a long-run positive impact of public debt on economic growth through the fiscal multiplier effect. The article also found that a few other studies support the Ricardian Equivalence Hypothesis (REH), which states that the relationship between public debt and economic growth is nonexistent. On balance, the article also found that there is a growing body of empirical evidence, which supports the presence of threshold effects in the relationship between public debt and economic growth. Overall, it concludes that theoretical models and empirical studies yield inconclusive results depending on a set of heterogeneous factors, including the level of development of the sampled countries, data coverage, methodology used, and the researchers’ choice of control variables, among other factors. This literature survey differs predominantly from other earlier studies in that it provides a comprehensive review of the linkage between government debt and economic growth, in addition to disentangling public debt into two components, domestic and foreign, and expounding on their relative effects on economic growth.


Author(s):  
Kelly C. Allison ◽  
Jennifer D. Lundgren

The Diagnostic and Statistical Manual, fifth edition, of the American Psychiatric Association (2013) has designated several disorders under the diagnosis of otherwise specified feeding and eating disorder (OSFED). This chapter evaluates three of these, night eating syndrome (NES), purging disorder (PD), and atypical anorexia nervosa (atypical AN). It also reviews orthorexia nervosa, which has been discussed in the clinical realm as well as the popular press. The history and definition for each is reviewed, relevant theoretical models are presented and compared, and evidence for the usefulness of the models is described. Empirical studies examining the disorders’ independence from other disorders, comorbid psychopathology, and, when available, medical comorbidities, are discussed. Distress and impairment in functioning seem comparable between at least three of these emerging disorders and threshold eating disorders. Finally, remaining questions for future research are summarized.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2231
Author(s):  
István Kiss ◽  
Krisztina Szigeti ◽  
Zalán G. Homonnay ◽  
Vivien Tamás ◽  
Han Smits ◽  
...  

Piglets from a porcine circovirus type 2 (PCV2) stable farm of low and high levels of maternally derived antibodies (MDA) against PCV2 were vaccinated either with a whole virus type or a PCV2 ORF2 antigen-based commercial subunit vaccine at three weeks of age. Two non-vaccinated groups served as low and high MDA positive controls. At four weeks post vaccination, all piglets were challenged with a PCV2d-2 type virus strain and were checked for parameters related to vaccine protection over a four-week observation period. MDA levels evidently impacted the outcome of the PCV2d-2 challenge in non-vaccinated animals, while it did not have a significant effect on vaccine-induced protection levels. The humoral immune response developed faster in the whole virus vaccinates than in the subunit vaccinated pigs in the low MDA groups. Further, high MDA levels elicited a stronger negative effect on the vaccine-induced humoral immune response for the subunit vaccine than for the whole virus vaccine. The group-based oral fluid samples and the group mean viraemia and faecal shedding data correlated well, enabling this simple, and animal welfare-friendly sampling method for the evaluation of the PCV2 viral load status of these nursery piglets.


Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1041
Author(s):  
Mohammad Tarek ◽  
Hana Abdelzaher ◽  
Firas Kobeissy ◽  
Hassan A. N. El-Fawal ◽  
Mohammed M. Salama ◽  
...  

The virus responsible for the COVID-19 global health crisis, SARS-CoV-2, has been shown to utilize the ACE2 protein as an entry point to its target cells. The virus has been shown to rely on the actions of TMPRSS2 (a serine protease), as well as FURIN (a peptidase), for the critical priming of its spike protein. It has been postulated that variations in the sequence and expression of SARS-CoV-2’s receptor (ACE2) and the two priming proteases (TMPRSS2 and FURIN) may be critical in contributing to SARS-CoV-2 infectivity. This study aims to examine the different expression levels of FURIN in various tissues and age ranges in light of ACE2 and TMPRSS2 expression levels using the LungMAP database. Furthermore, we retrieved expression quantitative trait loci (eQTLs) of the three genes and their annotation. We analyzed the frequency of the retrieved variants in data from various populations and compared it to the Egyptian population. We highlight FURIN’s potential interplay with the immune response to SARS-CoV-2 and showcase a myriad of variants of the three genes that are differentially expressed across populations. Our findings provide insights into potential genetic factors that impact SARS-CoV-2 infectivity in different populations and shed light on the varying expression patterns of FURIN.


2003 ◽  
Vol 77 (2) ◽  
pp. 99-109 ◽  
Author(s):  
J.M. Behnke ◽  
F. Iraqi ◽  
D. Menge ◽  
R.L. Baker ◽  
J. Gibson ◽  
...  

AbstractThe host-protective immune response to infection with gastrointestinal (GI) nematodes involves a range of interacting processes that begin with recognition of the parasite's antigens and culminate in an inflammatory reaction in the intestinal mucosa. Precisely which immune effectors are responsible for the loss of specific worms is still not known although many candidate effectors have been proposed. However, it is now clear that many different genes regulate the response and that differences between hosts (fast or strong versus slow or weak responses) can be explained by allelic variation in crucial genes associated with the gene cascade that accompanies the immune response and/or genes encoding constitutively expressed receptor/signalling molecules. Major histocompatibility complex (MHC) genes have been recognized for some time as decisive in controlling immunity, and evidence that non-MHC genes are equally, if not more important in this respect has also been available for two decades. Nevertheless, whilst the former have been mapped in mice, only two candidate loci have been proposed for non-MHC genes and relatively little is known about their roles. Now, with the availability of microsatellite markers, it is possible to exploit linkage mapping techniques to identify quantitative trait loci (QTL) responsible for resistance to GI nematodes. Four QTL for resistance to Heligmosomoides polygyrus, and additional QTL affecting faecal egg production by the worms and the accompanying immune responses, have been identified. Fine mapping and eventually the identification of the genes (and their alleles) underlying QTL for resistance/susceptibility will permit informed searches for homologues in domestic animals, and human beings, through comparative genomic maps. This information in turn will facilitate targeted breeding to improve resistance in domestic animals and, in human beings, focused application of treatment and control strategies for GI nematodes.


Author(s):  
H. Ensaff

Populations' diets typically fall short of recommendations. The implication of this on ill health and quality of life is well established, as are the subsequent health care costs. An area of growing interest within public health nutrition is food choice architecture; how a food choice is framed and its influence on subsequent food selection. In particular, there is an appeal to manipulating the choice architecture in order to nudge individuals' food choice. This review outlines the current understanding of food choice architecture, theoretical background to nudging and the evidence on the effectiveness of nudge strategies, as well as their design and implementation. Interventions emphasising the role of nudge strategies have investigated changes to the accessibility, availability and presentation of food and the use of prompts. Empirical studies have been conducted in laboratories, online and in real-world food settings, and with different populations. Evidence on the effectiveness of nudge strategies in shifting food choice is encouraging. Underpinning mechanisms, not yet fully explicated, are proposed to relate to salience, social norms and the principle of least effort. Emerging evidence points to areas for development including the effectiveness of choice architecture interventions with different and diverse populations, and the combined effect of multiple nudges. This, alongside further examination of theoretical mechanisms and guidance to engage and inspire across the breadth of food provision, is critical. In this way, the potential of choice architecture to effect meaningful change in populations' diets will be realised.


2021 ◽  
Vol 17 (3) ◽  
pp. 47-55
Author(s):  
Jane Kaboro ◽  
Naftaly Mose

Abstract Macroeconomic convergence is critical for member states to achieve the level of harmonization required for establishing a stable and resilient monetary union. The East African Community (EAC) member states, therefore, established set targets for macroeconomic convergence, intending to eliminate exchange rate uncertainty within the bloc and reduce the costs of the monetary union. However, recent empirical studies indicate that the rate of convergence of the member states to the set macroeconomic targets has been very slow, resulting in high exchange rate uncertainty within the region. It is against this backdrop that this research was conceptualized to examine the influence of convergence in macroeconomic variables on the exchange rate uncertainty of EAC states using secondary panel data. The study made use of standard deviation and the Levin Lin Chu (LLC) test to determine convergence and unit root respectively. The panel ordinary least squares (OLS) regression findings showed that all the explanatory variables had a negatively significant effect on exchange rate uncertainty. This implies that convergence in macroeconomic variables among the member countries slows exchange rate uncertainty. Thus, policy should be made towards controlling this negative effect resulting from macroeconomic variables as East Africa bids for monetary union.


Author(s):  
Mosab Nouraldein Mohammed Hamad ◽  
Sufian Khalid M. Noor ◽  
Awadalla H. Kashif ◽  
Mohammed Medani Eltayeb ◽  
Bader Saud Alotaibi ◽  
...  

Both malaria and leishmania  are most widespread protozoon parasitic diseases, certainly in tropical countries of the world. Malaria leishmania coinfection is common in leishmaniasis endemic areas which is mostly endemic to malaria too. Researchers notice that in cases of malaria leishmania coinfection , leishmania species find the some extent the outcome of malaria infection , but also behavior of malaria parasite species play a significant role to figure the consequences of it. While L. donovani protect from severe malaria complications by suppression of major histocompatibility class Ⅱ , so it diminish the clinical severity of malaria but not malaria parasite density due to dysfunction of major histocompatibility class I, which controlled by suppressed one, In another side L. mexicana tends to sequester in macrophages and lead to severe clinical outcomes when it coexisted with malaria parasite at same host. Experimental studies required to know more information about coinfection of different malaria and leishmania species to establish clinical research. Leishmania infection excluded when studies aim to assess the immune response to only malaria parasite, experimental studies required involving different species of malaria and leishmania.


Children ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 895
Author(s):  
Catarina Perpétuo ◽  
Eva Diniz ◽  
Manuela Veríssimo

Sleep is a biological process that impacts nearly every domain of a child’s life. Sleep-wake regulation influences and it is highly influenced by developmental variables related to parent-child relationships, such as attachment. The main goal of the present systematic review is to analyze and integrate the findings of empirical studies investigating the relations between attachment and sleep in preschool age, a period marked by important developmental changes that challenge both attachment system and sleep-wake regulation. A database search was performed using a combination of relevant keywords, leading to the identification of 524 articles, with 19 manuscripts assessed for eligibility; finally, seven studies (2344 children) were included. Overall, the findings were not consistent, with some studies reporting significant associations between attachment security and sleep quality, as well as between attachment insecurity and sleep problems, whereas others did not find significant associations. The results are discussed in light of the available theoretical models and integrated in the context of measurement approaches to attachment and sleep heterogeneity, aiming to guide future research on the topic.


2017 ◽  
Vol 44 (3) ◽  
pp. 535-545
Author(s):  
Luis R. Martínez-Córdova ◽  
Teresa Gollas-Galván ◽  
Estefanía Garibay-Valdez ◽  
Rocío Valenzuela-Gutiérrez ◽  
Marcel Martínez Porchas ◽  
...  

The physiological and immune responses of adult shrimp (Litopenaeus vannamei) undergoing the acute phase of the necrotizing hepatopancreatitis (NHP) disease and the efficiency of oxytetracycline (OXI) and florfenicol (FF) to eliminate the pathogen were evaluated. Four shrimp groups were considered: three groups infected with necrotizing hepatopancreatitis bacteria (NHP-B) (two treated with antibiotics and a positive control) and one group non-infected (negative control). Hemolymph concentration of glucose, lactate, acylglycerides, cholesterol, total protein, aminotransferases, superoxide dismutase, and the transcriptional expression of several immune related genes were monitored at the acute phase of the disease, and at 15 and 20 days after administration of antibiotics (daa). Shrimp from the positive control registered a mortality of 100%. NHP-B infection affected the immu-nophysiological response of shrimp; herein, most of the parameters were significantly up regulated in infected shrimp before the use of antibiotics, compared to the negative control. Increased transcriptional levels of clotting protein, lipopolysaccharide and β-1-3-glucan binding protein (LGBP), serine protease, peroxinectin, lysozyme, heat shock proteins (HSP) 60 and 70 were detected in shrimp treated with OXI. At 20 daa NHP-B was still detected in FF-treated shrimp, but not in OXI-treated shrimp. It is hypothesized that despite none of the antibiotics per se eliminated the bacterium, both had a negative effect on its virulence. OXI seems to have a greater effect, allowing shrimp to integrate a better immune response at 15 daa.


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