scholarly journals Symbiont infection affects aphid defensive behaviours

2011 ◽  
Vol 7 (5) ◽  
pp. 743-746 ◽  
Author(s):  
Emilie Dion ◽  
Sarah Erika Polin ◽  
Jean-Christophe Simon ◽  
Yannick Outreman
Keyword(s):  
Bacterial Symbiont ◽  
Buchnera Aphidicola ◽  
Behavioural Changes ◽  
Wide Range ◽  
Hamiltonella Defensa ◽  
Defensive Behaviours ◽  
Induced Changes ◽  
Aphid Populations

Aphids harbour both an obligate bacterial symbiont, Buchnera aphidicola , and a wide range of facultative ones. Facultative symbionts can modify morphological, developmental and physiological host traits that favour their spread within aphid populations. We experimentally investigated the idea that symbionts may also modify aphid behavioural traits to enhance their transmission. Aphids exhibit many behavioural defences against enemies. Despite their benefits, these behaviours have some associated costs leading to reduction in aphid reproduction. Some aphid individuals harbour a facultative symbiont Hamiltonella defensa that provides protection against parasitoids. By analysing aphid behaviours in the presence of parasitoids, we showed that aphids infected with H. defensa exhibited reduced aggressiveness and escape reactions compared with uninfected aphids. The aphid and the symbiont have both benefited from these behavioural changes: both partners reduced the fitness decrements associated with the behavioural defences. Such symbiont-induced changes of behavioural defences may have consequences for coevolutionary processes between host organisms and their enemies.

scholarly journals Drivers of Infectious Disease Seasonality: Potential Implications for COVID-19

2021 ◽  
pp. 074873042098732
Author(s):  
N. Kronfeld-Schor ◽  
T. J. Stevenson ◽  
S. Nickbakhsh ◽  
E. S. Schernhammer ◽  
X. C. Dopico ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Infectious Diseases ◽  
Multidisciplinary Approach ◽  
Preliminary Assessment ◽  
Epidemiological Evidence ◽  
Wide Range ◽  
Human Coronaviruses ◽  
Induced Changes ◽  
And Behavior ◽  
Timing Phase

Not 1 year has passed since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19). Since its emergence, great uncertainty has surrounded the potential for COVID-19 to establish as a seasonally recurrent disease. Many infectious diseases, including endemic human coronaviruses, vary across the year. They show a wide range of seasonal waveforms, timing (phase), and amplitudes, which differ depending on the geographical region. Drivers of such patterns are predominantly studied from an epidemiological perspective with a focus on weather and behavior, but complementary insights emerge from physiological studies of seasonality in animals, including humans. Thus, we take a multidisciplinary approach to integrate knowledge from usually distinct fields. First, we review epidemiological evidence of environmental and behavioral drivers of infectious disease seasonality. Subsequently, we take a chronobiological perspective and discuss within-host changes that may affect susceptibility, morbidity, and mortality from infectious diseases. Based on photoperiodic, circannual, and comparative human data, we not only identify promising future avenues but also highlight the need for further studies in animal models. Our preliminary assessment is that host immune seasonality warrants evaluation alongside weather and human behavior as factors that may contribute to COVID-19 seasonality, and that the relative importance of these drivers requires further investigation. A major challenge to predicting seasonality of infectious diseases are rapid, human-induced changes in the hitherto predictable seasonality of our planet, whose influence we review in a final outlook section. We conclude that a proactive multidisciplinary approach is warranted to predict, mitigate, and prevent seasonal infectious diseases in our complex, changing human-earth system.

scholarly journals Morphometric and Molecular Analyses of Ostertagia leptospicularis Assadov, 1953 from Ruminants: Species Diversity or Host Influence?

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 182
Author(s):  
Anna Wyrobisz-Papiewska ◽  
Jerzy Kowal ◽  
Elżbieta Łopieńska-Biernat ◽  
Paweł Nosal ◽  
Iwona Polak ◽  
...  
Keyword(s):  
Host Species ◽  
Roe Deer ◽  
Bos Taurus ◽  
Capreolus Capreolus ◽  
Nematode Species ◽  
Molecular Techniques ◽  
Systematic Classification ◽  
Morphological Variations ◽  
Wide Range ◽  
Induced Changes

Ostertagia leptospicularis Assadov, 1953 was formally described in roe deer Capreolus capreolus and has been reported in a wide range of ruminants, including other Cervidae, as well as Bovidae. Nematode specimens derived from various host species exhibit morphological similarity; however, some differences can be observed. It is unclear if this is due to the differential reaction of one nematode species in different host species (i.e., host-induced changes) or because of distinct nematode species in these hosts (i.e., species complex). This paper focuses on specimens resembling O. leptospicularis f. leptospicularis and its closely related species (Ostertagia ostertagi f. ostertagi) collected from various hosts. Morphometric and molecular techniques were applied to assess host-induced changes in nematode morphology and to clarify its systematic classification. There was an overall effect of host species on measurements of nematodes resembling O. leptospicularis (both males and females), but the distinctiveness of the specimens from cattle Bos taurus were highlighted. The results obtained may suggest that the specimens of O. leptospicularis from cattle in Germany and cervids in central Europe belong to different strains. Furthermore, nematodes from the cervid strain appear to circulate within particular host species, which can be seen in the stated morphological variations.

Influence of Cotton Fiber Strength and Fineness on Fiber Damage during Lint Cleaning

1988 ◽  
Vol 58 (8) ◽  
pp. 433-438 ◽  
Author(s):  
J. K. Dever ◽  
J. R. Gannaway ◽  
R. V. Baker
Keyword(s):  
Significant Relationship ◽  
Cotton Fiber ◽  
Fiber Length ◽  
Fiber Strength ◽  
Fiber Breakage ◽  
Fiber Damage ◽  
Fiber Properties ◽  
Fiber Fineness ◽  
Wide Range ◽  
Induced Changes

Seven sources of cotton representing a wide range of fiber properties were roller ginned, saw ginned, or saw ginned plus processed through tandem saw lint cleaners or through an aggressive carding-type cleaner (Cottonmaster1). Lint cleaner induced changes in fiber length and nep count were compared to fiber property measurements from roller ginned samples. Fiber length deterioration from saw ginning was negatively correlated with fiber strength. Fiber breakage in lint cleaning was positively correlated with fiber fineness. Resistance to fiber length damage in ginning was explained best by fiber strength and fineness, or an estimate of individual fiber strength. Initial and final nep level were related to fineness, nonlint content, and upper quartile length, but an increase in neps due to lint cleaning had no significant relationship to fiber properties.

Abstract 196: Involvement of Peroxynitrite Formation in Angiotensin II Induced Changes in Na+K+ATPase Activity in HK2 Cells

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Arpan K Maiti ◽  
Mohammed T Islam ◽  
Ryosuke Satou ◽  
Dewan S Majid
Keyword(s):  
Angiotensin Ii ◽  
Colorimetric Assay ◽  
Renin Angiotensin System ◽  
Human Kidney ◽  
Protective Role ◽  
Renal Tubules ◽  
Proximal Tubule Cell ◽  
Wide Range ◽  
Induced Changes ◽  
Hk2 Cells

Angiotensin II (AngII) induces both superoxide (O 2 - ) and nitric oxide (NO) generation forming peroxynitrite (ONOO - ) in biological systems. To determine the role of ONOO - in AngII induced sodium excretory responses, we examined Na + K + ATPase (NKA) activity in cultured HK2 cells (human kidney proximal tubule cell line) incubated for 30 min with a wide range (10 pM to 200 μM) of AngII concentrations (conc) in the presence or absence of a ONOO - scavenger, mercapto-ethyl-guanadine (MEG; 200μM). Post incubation HK2 cellular membrane fractions were used for measurement of NKA activity via colorimetric assay capable of detecting inorganic phosphate (Pi). Baseline value of NKA activity in these HK2 cells was measured as 10.3 ±0.7 μmoles of Pi liberated/mg protein/hr (n=12). AngII exerts dose-dependent differential effects on NKA activity. Compared to the baseline value, NKA activity was increased at lower conc (13.7±1.3% at 10 pM to 19.6±1.5% at 100nM) and decreased at higher conc (-6.0±0.8% at 1 μM to -38±2.1% at 200 μM ) without any significant effect at 500 nM conc (-1.2±0.6%) of AngII. Interestingly, MEG treatment markedly attenuated these AngII induced changes in NKA activity, both at lower conc (activity increased only to 7.8±0.67% at 10 pM and to 8.9±0.57% at 100nM; an average reduction of 33.2±2.4% in stimulatory effects) and at higher conc (activity decreased to -3.0±0.7% at 1 μM and to -20±0.57% at 200 μM; an average reduction of 54.4±4.1% in inhibitory effects). Co-incubation with O 2 - scavenger, tempol (1 mM) or NO synthase inhibitor, nitro-L-arginine methyl ester (100 μM) did not alter these AngII induced responses in HK2 cells indicating that neither O 2 - , nor NO, was directly involved in mediating these responses. AT 1 receptor (AT 1 R) blocker, losartan (10μM) treatment prevented these AngII induced changes on NKA activity confirming the involvement of AT 1 R signaling in these responses. These findings demonstrate a direct contributory role for concomitant ONOO - generation in mediating AngII induced changes in NKA activity in the proximal tubular cells. These data also suggest a reno-protective role for ONOO - in minimizing sodium retaining action of AngII by the renal tubules, particularly in the conditions associated with enhanced renin-angiotensin system.

Diet selection in broiler chickens with corticosterone-induced changes in body composition

1997 ◽  
Vol 20 ◽  
pp. 121-123
Author(s):  
A. Sahin ◽  
J. M. Forbes
Keyword(s):  
Body Composition ◽  
Broiler Chickens ◽  
Diet Selection ◽  
Protein Concentrate ◽  
Male And Female ◽  
Protein Deposition ◽  
Macronutrient Selection ◽  
Wide Range ◽  
Corticosterone Treatment ◽  
Induced Changes

Birds attempt to compensate for an E : P (energy: protein) imbalance by increasing their intake of protein or energy from selected foods and this is related to changes in the birds’ body composition caused by corticosterone treatment.Corticosterone injections increase fatness despite increasing nitrogen and energy excretion (Bartov, 1985). More recently corticosterone has been used to modulate macronutrient selection in rats (Devenport et al., 1991; Bligh et al., 1993; Tempel et al., 1993) and chickens (Covasa and Forbes, 1995). The intake of high protein concentrate was decreased by corticosterone treatment in young chickens but not in older chickens (Covasa and Forbes, 1995). The previous results suggest that more information on corticosterone’s effect on diet selection will be obtained by using foods which can offer a wide range of choices to compose a proper diet (Covasa and Forbes, 1995). Therefore, two experiments were conducted to detect changes in protein preference in relation to reduced protein deposition and enhanced fattening induced by corticosterone in male and female growing broiler chickens.

scholarly journals Sulfate geoengineering: a review of the factors controlling the needed injection of sulfur dioxide

2017 ◽  
Vol 17 (6) ◽  
pp. 3879-3889 ◽  
Author(s):  
Daniele Visioni ◽  
Giovanni Pitari ◽  
Valentina Aquila
Keyword(s):  
Sulfur Dioxide ◽  
Lower Stratosphere ◽  
Effective Means ◽  
Atmospheric Models ◽  
Radiative Effects ◽  
Stratospheric Water Vapor ◽  
Wide Range ◽  
Volcanic Aerosols ◽  
Aerosol Effects ◽  
Induced Changes

Abstract. Sulfate geoengineering has been proposed as an affordable and climate-effective means to temporarily offset the warming produced by the increase of well-mixed greenhouse gases (WMGHGs). This technique would likely have to be applied while and after global intergovernmental measures on emissions of WMGHGs are implemented in order to achieve surface temperature stabilization. The direct radiative effects of sulfur injection in the tropical lower stratosphere can be summarized as increasing shortwave scattering with consequent tropospheric cooling and increasing longwave absorption with stratospheric warming. Indirect radiative effects are related to induced changes in the ozone distribution; stratospheric water vapor abundance,;formation and size of upper-tropospheric cirrus ice particles; and lifetime of long-lived species, namely CH4 in connection with OH changes through several photochemical mechanisms. Direct and indirect effects of sulfate geoengineering both concur to determine the atmospheric response. A review of previous studies on these effects is presented here, with an outline of the important factors that control the amount of sulfur dioxide to be injected in an eventual realization of the experiment. However, we need to take into account that atmospheric models used for these studies have shown a wide range of climate sensitivity and differences in the response to stratospheric volcanic aerosols. In addition, large uncertainties exist in the estimate of some of these aerosol effects.

Altered balance of main vasopressor and vasodepressor systems in rats with genetic hypertension and hypertriglyceridaemia

2002 ◽  
Vol 102 (3) ◽  
pp. 269-277 ◽  
Author(s):  
Jaroslav KUNEŠ ◽  
Zdenka DOBEŠOVÁ ◽  
Josef ZICHA
Keyword(s):  
Renin Angiotensin System ◽  
No Synthase ◽  
Superoxide Anions ◽  
Angiotensin System ◽  
Genetic Hypertension ◽  
Wide Range ◽  
Sympathetic Nervous ◽  
Induced Changes ◽  
Precise Role

The precise role of nitric oxide (NO) in hypertension is still not fully understood, although this vasodilator system represents the main counterbalance of major pressor systems. The aim of our study was to determine the contributions of superoxide anions, the renin-angiotensin system (RAS), the sympathetic nervous system (SNS) and NO to the maintenance of blood pressure (BP) in Prague hereditary hypertriglyceridaemic (HTG) rats with genetic hypertension. Conscious chronically cannulated rats were subjected to the consecutive blockade of the RAS (losartan, 10mg/kg), the SNS (pentolinium, 5mg/kg) and NO synthase [Nω-nitro-l-arginine (l-NAME), 30mg/kg]. Some additional rats were pretreated with tempol (a membrane-permeable mimetic of superoxide dismutase). A subsequent genetic study in HTG×Lewis F2 hybrid rats (n = 284) was designed to reveal potential associations of particular BP components with baseline BP. The progenitor study indicated that BP elevation was more pronounced in male than female HTG rats (as compared with normotensive Lewis controls). Higher BP in HTG rats was due to the increased residual BP (measured after combined RAS and SNS blockade) and the augmentation of BP responses to tempol or losartan. In contrast, BP responses to pentolinium or l-NAME were similar in all experimental groups. It should, however, be noted that the baseline BP of progenitor animals was correlated positively with both residual BP and the magnitude of the BP response to pentolinium, but not with BP response to l-NAME. Similarly, the baseline BP of F2 hybrid rats was positively associated with residual BP, the BP response to pentolinium and the relative SNS contribution to BP maintenance [expressed as a percentage of baseline mean arterial pressure (MAP) values], as well as with the ratio of BP changes elicited by ganglion blockade and NO synthase inhibition (ΔMAPpentolinium/ΔMAPl-NAME ratio), reflecting the balance of main vasopressor and vasodepressor systems. Thus our studies, performed in progenitor and F2 hybrid rats, revealed that changes in BP induced by l-NAME do not keep pace with the progressive augmentation of pentolinium-induced changes in BP occurring over a wide range of increasing BP. The altered balance between enhanced SNS-dependent vasoconstriction and unchanged NO-dependent vasodilation (‘relative NO deficiency’ in rats with high BP) might result in BP elevation in this form of genetic hypertension.

scholarly journals Isolation of the Buchnera aphidicola flagellum basal body complexes from the Buchnera membrane

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0245710
Author(s):  
Matthew J. Schepers ◽  
James N. Yelland ◽  
Nancy A. Moran ◽  
David W. Taylor
Keyword(s):  
Basal Body ◽  
Gene Clusters ◽  
Cellular Membrane ◽  
Structure And Function ◽  
Bacterial Symbiont ◽  
Structural Proteins ◽  
Buchnera Aphidicola ◽  
Large Numbers ◽  
And Function ◽  
Aphid Host

Buchnera aphidicola is an intracellular bacterial symbiont of aphids and maintains a small genome of only 600 kbps. Buchnera is thought to maintain only genes relevant to the symbiosis with its aphid host. Curiously, the Buchnera genome contains gene clusters coding for flagellum basal body structural proteins and for flagellum type III export machinery. These structures have been shown to be highly expressed and present in large numbers on Buchnera cells. No recognizable pathogenicity factors or secreted proteins have been identified in the Buchnera genome, and the relevance of this protein complex to the symbiosis is unknown. Here, we show isolation of Buchnera flagellum basal body proteins from the cellular membrane of Buchnera, confirming the enrichment of flagellum basal body proteins relative to other proteins in the Buchnera proteome. This will facilitate studies of the structure and function of the Buchnera flagellum structure, and its role in this model symbiosis.

scholarly journals Mesenchymal stromal cell apoptosis is required for their therapeutic function

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Swee Heng Milon Pang ◽  
Joshua D’Rozario ◽  
Senora Mendonca ◽  
Tejasvini Bhuvan ◽  
Natalie L. Payne ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Clinical Utility ◽  
Multipotent Mesenchymal Stromal Cells ◽  
Bioactive Molecules ◽  
Therapeutic Effects ◽  
Wide Range ◽  
Therapeutic Function ◽  
Induced Changes ◽  
Reduce Disease Severity ◽  
Effective Translation

AbstractMultipotent mesenchymal stromal cells (MSCs) ameliorate a wide range of diseases in preclinical models, but the lack of clarity around their mechanisms of action has impeded their clinical utility. The therapeutic effects of MSCs are often attributed to bioactive molecules secreted by viable MSCs. However, we found that MSCs underwent apoptosis in the lung after intravenous administration, even in the absence of host cytotoxic or alloreactive cells. Deletion of the apoptotic effectors BAK and BAX prevented MSC death and attenuated their immunosuppressive effects in disease models used to define MSC potency. Mechanistically, apoptosis of MSCs and their efferocytosis induced changes in metabolic and inflammatory pathways in alveolar macrophages to effect immunosuppression and reduce disease severity. Our data reveal a mode of action whereby the host response to dying MSCs is key to their therapeutic effects; findings that have broad implications for the effective translation of cell-based therapies.

The design of a strategy to encourage voluntary travel behaviour change: a cap and save programme

2012 ◽  
pp. 11-30
Author(s):  
Italo Meloni ◽  
Erika Spissu
Keyword(s):  
Daily Activity ◽  
Travel Behaviour ◽  
Travel Patterns ◽  
Accurate Analysis ◽  
Behavioural Changes ◽  
Behavioural Strategy ◽  
Wide Range ◽  
Before And After ◽  
Reduce Emissions ◽  
The Individual

The objective of this work is to explore the contribution of daily activity-travel patterns to carbon emissions, and to define the steps for the implementation of an effective behavioural strategy to encourage voluntary travel behavioural changes. This work proposes an extensive review of the most relevant strategies implemented to achieve sustainable objectives. In particular, the focus is on those strategies aimed at changing human behaviour, debated both in transportation (Structural strategies) and in sociological and psychological (Cognitive-Motivational strategies) fields. Further, international experiences of Voluntary Travel Behavioural Changes programs, as opposed to compulsory measures (i.e. taxation, restrictions etc.), are investigated. Finally, the work describes the results of a pilot survey held in Cagliari (Italy) to test a behavioural strategy called "Cap and Save". The basic idea of the Cap and Save is that voluntary travel behavioural changes are more likely when the individuals are able to recognize a personal profit. The Cap and Save program combines a number of key aspects from behavioural strategies reviewed in the literature (i.e. Tradable Exploitation Rights, Personal Journey Planning etc.): first, individuals are free to modify their behaviour; second, a cognitive-motivational process is set forth to increase awareness of sustainable behaviours. Third, each individual receives an annual emissions limit (cap) and a monetary incentive (save) to reduce emissions; fourth, a set of personalized alternatives is tailored for the individual in order to reduce weekly mileage. Finally, the Cap and Save program relies on an accurate analysis of activity-travel behaviour before and after policy intervention. The initial test of the Cap and Save programme was conducted during a two-week survey (July-October 2009), which involved a group of students from the University of Cagliari (Italy). The first week, the students were invited to record their actual daily activity-travel patterns. The second week, they were asked to repeat the survey, this time they were challenged to maintain a weekly cap of kilometres travelled thereby saving the corresponding resources (i.e. environmental and monetary). Each student was provided with a set of personalized alternatives, which (if followed) would result in a 20% reduction of kilometres travelled. The comparison of before and after strategy implementation highlights the implications of Cap and Save on a wide range of individual daily activities and, specifically, on personal car usage.

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