Dynamics Of Components Research Articles

Bidirectional interactions between host social behaviour and parasites arise through ecological and evolutionary processes.

An animal's social behaviour both influences and changes in response to its parasites. Here we consider these bidirectional links between host social behaviours and parasite infection, both those that occur from ecological vs evolutionary processes. First, we review how social behaviours of individuals and groups influence ecological patterns of parasite transmission. We then discuss how parasite infection, in turn, can alter host social interactions by changing the behaviour of both infected and uninfected individuals. Together, these ecological feedbacks between social behaviour and parasite infection can result in important epidemiological consequences. Next, we consider the ways in which host social behaviours evolve in response to parasites, highlighting constraints that arise from the need for hosts to maintain benefits of sociality while minimizing fitness costs of parasites. Finally, we consider how host social behaviours shape the population genetic structure of parasites and the evolution of key parasite traits, such as virulence. Overall, these bidirectional relationships between host social behaviours and parasites are an important yet often underappreciated component of population-level disease dynamics and host-parasite coevolution.

Vegetation controls on surface energy partitioning and water budget over China

Understanding how biophysical processes respond to the surface energy partitioning and water budget is essential for modeling land surface processes. In general, evapotranspiration (ET) associated with vegetation dynamics can function as a vital nexus of the surface energy partitioning and water budget. Here, a dual-source ET model, the GIS-based Priestley-Taylor Jet Propulsion Laboratory (GIS-based PT-JPL) model, was constructed by incorporating a component of vegetation dynamics for quantifying the influences of vegetation greening on surface energy partitioning and water budget in mainland China from 1982 to 2015. To evaluate the effect of vegetation greening on evaporative water consumption, two simulation scenarios were compared: with and without revegetation. The results reveal that the increased Leaf Area Index led to a reduction in surface albedo by an average rate of −0.001 yr−2 from 1982 to 2015. The net terrestrial radiation exhibited a notable upward trend (at a rate of 0.0594 W·m−2·yr−2), which could be caused by the decrease in surface albedo and the positive greenhouse effect. The increase in net terrestrial radiation enhanced both sensible and latent heat flux, thus leading to a significant growing trend of ET (at a rate of 0.39 mm·yr−2) over mainland China. The results of two simulation scenarios show that the evaporative water consumption with revegetation was 5.1% higher than that without revegetation. And the ratio of water yield in 10 of 11 river basins decreased around 1.6–19.4% over the past three decades for revegetation. These findings broaden the current knowledge about how to ensure ecologically sustainable restoration and manage the long-term revegetation strategy.

Identification of possible dynamical drivers for long-term changes in temperature and rainfall patterns over Europe

This study looks into the question to what extent long-term change patterns of observed temperature and rainfall over Europe can be attributed to dynamical causes, in other words: Are the observed changes due to a change in frequency of the patterns or have the patterns’ dynamical properties changed? By using a combination of daily meteorological data and a European weather-type classification, the long-term monthly mean temperature and precipitation were calculated for each weather-type. Subsequently, the observed weather-type sequences were used to construct analogue time series for temperature and precipitation which only include the dynamical component of the long-term variability since 1961. The results show that only a fraction of about 20% of the past temperature rise since 1990, which for example amounted to 1 °C at the Potsdam Climate Station can be explained by dynamical changes, i.e. most of the weather-types have become warmer. Concerning long-term changes of seasonal rainfall patterns, a fraction of more than 60% is considerably higher. Moreover, the results indicate that for rainfall compared with temperature, the decadal variability and trends of the dynamical component follow the observed ones much stronger. Consequently, most of the explained seasonal rainfall variances can be linked to changes in weather-type sequences in Potsdam and over Europe. The dynamical contribution to long-term changes in annual and seasonal rainfall patterns dominates due to the fact that the alternation of wet and dry weather-types (e.g. the types Trough or High pressure over Central Europe), their frequencies and duration has significantly changed in the last decades.

An insight into the prey spectra and livestock predation by cheetahs in Kenya using faecal DNA metabarcoding

Dietary composition is a fundamental part of animal ecology and an important component of population dynamics. Therefore, obtaining accurate information on what an animal consumes is important for conservation planning, especially for wild large carnivores that exist in human-dominated landscapes where they are prone to direct conflicts with local people. We used faecal DNA metabarcoding to identify the vertebrate taxa commonly predated on by cheetahs (Acinonyx jubatus) with an emphasis on domestic taxa and determine the drivers of livestock predation by cheetahs residing in the Maasai Mara and Amboseli ecosystems which are important population strongholds in southern Kenya. From 84 cheetah faeces that we analysed, a total of 14 prey taxa were identified, including birds, wild and domestic mammals. The livestock taxa identified in cheetah faeces occurred at moderate frequency (12.8%) and the results showed that livestock predation was influenced neither by the sex of the cheetah nor by season. In general, our study shows that cheetahs prey on a diverse range of prey taxa including birds, wild ungulates of various sizes and occasionally on domestic animals, and that the faecal DNA metabarcoding approach represents a valuable complement to traditional dietary analysis methods.

Secondary production is an underutilized metric to assess restoration initiatives

Secondary production is an integrative measure of the accumulation of heterotrophic biomass through time and can be a valuable tool to design, implement, and assess restoration initiatives. To highlight applications of secondary production in restoration contexts, we identify recent papers from the literature, use these to make generalizations about how the concept is applied, and examine why it may not be utilized more commonly. We identified 21 papers that empirically quantified secondary production to compare pre/post-restoration or assess restored sites relative to reference ones. Every study was aquatic, suggesting that secondary production is an underutilized tool in terrestrial restoration studies. We discuss various ways that food web perspectives inform restoration secondary production outcomes, such as through shifts in aquatic basal resource pools and alleviation of nutrient limitation, changes which ripple through food webs supporting higher trophic level production. Despite challenges inherent to calculating secondary production, the approach holds much promise—it is a composite metric simultaneously reflecting components of ecosystem structure and dynamics that restoration initiatives target.

Smoke with Induced Rotation and Lofting (SWIRL) in the Stratosphere

AbstractThe Australian bushfires of 2019/20 produced an unusually large number of pyrocumulonimbus (pyroCb) that injected huge amounts of smoke into the lower stratosphere. The pyroCbs from 29 December 2019 to 4 January 2020 were particularly intense, producing hemispheric-wide aerosol that persisted for months. One plume from this so-called Australian New Year (ANY) event evolved into a stratospheric aerosol mass ~1000 km across and several kilometers thick. This plume initially moved eastward toward South America in January, then reversed course and moved westward passing south of Australia in February and eventually reached South Africa in early March. The peculiar motion was related to the steady rise in plume potential temperature of ~8 K day−1 in January and ~6 K day−1 in February, due to local heating by smoke absorption of solar radiation. This heating resulted in a vertical temperature anomaly dipole, a positive potential vorticity (PV) anomaly, and anticyclonic circulation. We call this dynamical component of the smoke plume “smoke with induced rotation and lofting” (SWIRL). This study uses Navy Global Environmental Model (NAVGEM) analyses to detail the SWIRL structure over 2 months. The main diagnostic tool is an anticyclone edge calculation based on the scalar Q diagnostic. This provides the framework for calculating the time evolution of various SWIRL properties: PV anomaly, streamfunction, horizontal size, vertical thickness, flow speed, and tilt. In addition, we examine the temperature anomaly dipole, the SWIRL interaction with the large-scale wind shear, and the ozone anomaly associated with lofting of air from the lower to the middle stratosphere.

“It’s The End of Bank Branching As We Know It (And We Feel Fine)”

Banks are closing branches at an unprecedented rate. In various countries up to four out of five branches have been closed, while in the US over 11,000 branches representing eleven percent of its peak stock in 2009 have been closed so far. To differentiate between various explanations for this fundamental transformation, we comprehensively study branching dynamics across 36 OECD countries, 2,744 US counties, and 84,494 US branches over up to 26 years. While technological factors explain some of the change in branch numbers across countries, counties, and individual banks, bank fragility and consolidation surprisingly determine an even larger component of branching dynamics. Interestingly, online banking capabilities play a less important role than internal processing technology. While large banks rely on technology to shed branches, small banks close branches when fragile or consolidating. No single factor by itself offers a universal explanation for the secular de-branching of banks.

Charge-State-Dependent Energization of Suprathermal Ions During Substorm Injections Observed by MMS in the Magnetotail.

Understanding the energization processes and constituent composition of the plasma and energetic particles injected into the near‐Earth region from the tail is an important component of understanding magnetospheric dynamics. In this study, we present multiple case studies of the high‐energy (40 keV) suprathermal ion populations during energetic particle enhancement events observed by the Energetic Ion Spectrometer (EIS) on NASA's Magnetospheric Multiscale (MMS) mission in the magnetotail. We present results from correlation analysis of the flux response between different energy channels of different ion species (hydrogen, helium, and oxygen) for multiple cases. We demonstrate that this technique can be used to infer the dominant charge state of the heavy ions, despite the fact that charge is not directly measured by EIS. Using this technique, we find that the energization and dispersion of suprathermal ions during energetic particle enhancements concurrent with (or near) fast plasma flows are ordered by energy per charge state (E/q) throughout the magnetotail regions examined (~7 to 25 Earth radii). The ions with the highest energies (300 keV) are helium and oxygen of solar wind origin, which obtain their greater energization due to their higher charge states. Additionally, the case studies show that during these injections the flux ratio of enhancement is also well ordered by E/q. These results expand on previous results which showed that high‐energy total ion measurements in the magnetosphere are dominated by high‐charge‐state heavy ions and that protons are often not the dominant species above ~300 keV.

Advanced risk-based event attribution for heavy regional rainfall events

Risk-based event attribution (EA) science involves probabilistically estimating alterations of the likelihoods of particular weather events, such as heat waves and heavy rainfall, owing to global warming, and has been considered as an effective approach with regard to climate change adaptation. However, risk-based EA for heavy rain events remains challenging because, unlike extreme temperature events, which often have a scale of thousands of kilometres, heavy rainfall occurrences depend on mesoscale rainfall systems and regional geographies that cannot be resolved using general circulation models (GCMs) that are currently employed for risk-based EA. Herein, we use GCM large-ensemble simulations and high-resolution downscaled products with a 20-km non-hydrostatic regional climate model (RCM), whose boundary conditions are obtained from all available GCM ensemble simulations, to show that anthropogenic warming increased the risk of two record-breaking regional heavy rainfall events in 2017 and 2018 over western Japan. The events are examined from the perspective of rainfall statistics simulated by the RCM and from the perspective of background large-scale circulation fields simulated by the GCM. In the 2017 case, precipitous terrain and a static pressure pattern in the synoptic field helped reduce uncertainty in the dynamical components, whereas in the 2018 case, a static pressure pattern in the synoptic field provided favourable conditions for event occurrence through a moisture increase under warmer climate. These findings show that successful risk-based EA for regional extreme rainfall relies on the degree to which uncertainty induced by the dynamic components is reduced by background conditioning.

Water availability drives fine root dynamics in a Eucalyptus woodland under elevated atmospheric CO2 concentration

Abstract Fine roots are a key component of carbon and nutrient dynamics in forest ecosystems. Rising atmospheric [CO2] (eCO2) is likely to alter the production and activity of fine roots, with important consequences for forest carbon storage. Yet empirical evidence of the role of eCO2 in driving root dynamics is limited, particularly for grassy woodlands, an ecosystem type of global importance. We sampled fine roots across seasons over a 2‐year period to examine the effects of eCO2 on their biomass, production, turnover and functional traits in a native mature grassy Eucalyptus woodland in eastern Australia (EucFACE). Fine root biomass, production and turnover varied greatly through time, increasing as soil water content declined. Despite a lack of consistent effects of eCO2 on fine root biomass, production or turnover across the 2‐year sampling period, we found enhanced production pulses under eCO2 between 10‐ and 30‐cm soil depth. In addition, eCO2 led to greater carbon and phosphorus concentrations in fine roots and increased root diameter, but no detectable effects on other morphological traits. Synthesis. We found minor quantitative effects of eCO2 on fine root biomass dynamics that were largely driven by temporal variations in soil water availability. Our results suggest that in this mature grassy woodland, and perhaps also in other similar forested ecosystem types, eCO2 effects are small and transient. This also implies a limited ability of these systems to mitigate climate change through below‐ground mechanisms. A free Plain Language Summary can be found within the Supporting Information of this article.

Population dynamics model and analysis for bacteria transformation and conjugation

We present a two-species population model in a well-mixed environment where the dynamics involves, in addition to birth and death, changes due to environmental factors and inter-species interactions. The novel dynamical components are motivated by two common mechanisms for developing antibiotic resistance in bacteria: plasmid transformation, where external genetic material in the form of a plasmid is transferred inside a host cell; and conjugation by which one cell transfers genetic material to another by direct cell-to-cell contact. Through analytical and numerical methods, we identify the effects of transformation and conjugation individually. With transformation only, the two-species system will evolve towards one species’ extinction, or a stable co-existence in the long-time limit. With conjugation only, we discover interesting oscillations for the system. Further, we quantify the combined effects of transformation and conjugation, and chart the regimes of stable co-existence, a result with ecological implications.

A note on the effects of epidemic forecasts on epidemic dynamics.

The purpose of a forecast, in making an estimate about the future, is to give people information to act on. In the case of a coupled human system, a change in human behavior caused by the forecast can alter the course of events that were the subject of the forecast. In this context, the forecast is an integral part of the coupled human system, with two-way feedback between forecast output and human behavior. However, forecasting programs generally do not examine how the forecast might affect the system in question. This study examines how such a coupled system works using a model of viral infection—the susceptible-infected-removed (SIR) model—when the model is used in a forecasting context. Human behavior is modified by making the contact rate responsive to other dynamics, including forecasts, of the SIR system. This modification creates two-way feedback between the forecast and the infection dynamics. Results show that a faster rate of response by a population to system dynamics or forecasts leads to a significant decline in peak infections. Responding to a forecast leads to a lower infection peak than responding to current infection levels. Inaccurate forecasts can lead to either higher or lower peak infections depending on whether the forecast under-or over-estimates the peak. The direction of inaccuracy in a forecast determines whether the outcome is better or worse for the population. While work is still needed to constrain model functional forms, forecast feedback can be an important component of epidemic dynamics that should be considered in response planning.

Thoracic Quantitative Dynamic MRI to Understand Developmental Changes in Normal Ventilatory Dynamics

A database of normative quantitative measures of regional thoracic ventilatory dynamics, which is essential to understanding better thoracic growth and function in children, does not exist. How to quantify changes in the components of ventilatory pump dynamics during childhood via thoracic quantitative dynamic MRI (QdMRI)? Volumetric parameters were derived via 51 dynamic MRI scans for left and right lungs, hemidiaphragms, and hemichest walls during tidal breathing. Volume-based symmetry and functional coefficients were defined to compare left and right sides and to compare contributions of the hemidiaphragms and hemichest walls with tidal volumes (TVs). Statistical analyses were performed to compare volume components among four age-based groups. Right thoracic components were significantly larger than left thoracic components, with average ratios of 1.56 (95%CI, 1.41-1.70) for lung TV, 1.81 (95%CI, 1.60-2.03) for hemidiaphragm excursion TV, and 1.34 (95%CI, 1.21-1.47) for hemichest wall excursion TV. Right and left lung volumes at end-expiration showed, respectively, a 44%and 48%increase from group 2 (8≤ age< 10) to group 3 (10≤ age< 12). These numbers from group 3 to group 4 (12≤ age≤ 14) were 24%and 28%, respectively. Right and left hemichest wall TVs exhibited, respectively, 48%and 45%increases from group 3 to group4. Normal right and left ventilatory volume components have considerable asymmetry in morphologic features and dynamics and change with age. Chest wall and diaphragm contributions vary in a likewise manner. Thoracic QdMRI can provide quantitative data to characterize the regional function and growth of the thorax as it relates to ventilation.

Running vacuum in quantum field theory in curved spacetime: renormalizing rho _{vac} without sim m^4 terms

The Lambda -term in Einstein’s equations is a fundamental building block of the ‘concordance’ Lambda CDM model of cosmology. Even though the model is not free of fundamental problems, they have not been circumvented by any alternative dark energy proposal either. Here we stick to the Lambda -term, but we contend that it can be a ‘running quantity’ in quantum field theory (QFT) in curved space time. A plethora of phenomenological works have shown that this option can be highly competitive with the Lambda CDM with a rigid cosmological term. The, so-called, ‘running vacuum models’ (RVM’s) are characterized by the vacuum energy density, rho _{vac}, being a series of (even) powers of the Hubble parameter and its time derivatives. Such theoretical form has been motivated by general renormalization group arguments, which look plausible. Here we dwell further upon the origin of the RVM structure within QFT in FLRW spacetime. We compute the renormalized energy-momentum tensor with the help of the adiabatic regularization procedure and find that it leads essentially to the RVM form. This means that rho _{vac}(H) evolves as a constant term plus dynamical components {{mathcal {O}}}(H^2) and mathcal{O}(H^4), the latter being relevant for the early universe only. However, the renormalized rho _{vac}(H) does not carry dangerous terms proportional to the quartic power of the masses (sim m^4) of the fields, these terms being a well-known source of exceedingly large contributions. At present, rho _{vac}(H) is dominated by the additive constant term accompanied by a mild dynamical component sim nu H^2 (|nu |ll 1), which mimics quintessence.

Recruitment of coral reef fishes along a cross-shelf gradient in the Red Sea peaks outside the hottest season

Knowledge on the early life history, ecology, and biology of marine species is crucial for future projections of the resilience of coral reef ecosystems and for adequate management strategies. A fundamental component of population dynamics is the recruitment of new individuals, and in some marine populations, this may be a limiting factor. Recruitment peaks of coral reef fishes commonly occur during the warmer months of the year in many subtropical and temperate locations worldwide. In the Red Sea, very little is known about the influence of temperature on reproductive patterns of coral reef fishes and studies on recruitment are missing. The Red Sea is one of the hottest and most isolated tropical seas in the world. We hypothesized that sea surface temperatures (SSTs) during the Red Sea’s hottest season may exceed the optimum for successful recruitment of some coral reef fishes, which therefore has to occur during other, cooler seasons, unlike recruitment among coral reef ecosystems around the world. We identified taxa among fish recruits by matching mitochondrial DNA sequences (using COI, commonly known as “barcoding”) and assessed potential biological and environmental drivers of recruitment. We studied three reefs located along a cross-shelf gradient for 12 consecutive months in the central Red Sea to capture seasonal changes in biotic and abiotic parameters along this gradient. Our results indicated that recruitment peaks did not occur during the hottest SSTs for most taxa, especially at the hottest inshore and mid-shelf reefs, and identified fish recruitment to be mainly and strongly correlated with the biomass of planktonic invertebrates. Moreover, temporal patterns of fish recruitment differed within and among taxonomic families among the reefs.

Survival rates on pre-weaning European hares (Lepus europaeus) in an intensively used agricultural area

The primary cause of the long-term decline in European hares’ (Lepus europaeus) population throughout Europe is widely assumed to be the intensification of agriculture. A critical component in this population dynamics is seen in the survival of leverets from birth to reproductive age. In European hares, the first stage of life until weaning has been sparsely studied, in particular habitat selection, movements and survival rate, as juveniles’ precocial lifestyle is dominated by any kind of anti-predation behaviour. In the present study, free-living and pre-weaning European hares were detected systematically by thermography (n = 394), being radio-tagged or marked (n = 229) from birth until the fifth week of life to research the early juvenile survival and proximate causes of mortality. Kaplan-Meier survival curves were computed overall and in relation to the strata of season, sex and type of daytime resting place. The survival rate of radio-tagged leverets was 0.35 in the first month of life, and 0.63, 0.52 and 0.44 for the first, second and third week of life, respectively. Approximately 21.6% and 50% of all confirmed deaths occurred during the first 7 and 13 days after birth. By the end of the 4th week of life, the mortality rate caused by predation, suspected predation, agricultural practices and unexplained cases was 41.7%, 36.7%, 11.7% and 10.0%, respectively. There was no significant difference in survival between the sexes and seasons. In contrast, young hares died more frequently as a consequence of choosing a hiding place without shelter during the daytime.

Changes in Tropical Precipitation Intensity With El Niño Warming

AbstractMesoscale convection generates the majority of extreme precipitation in tropical regions. Changes to these precipitation intensities, P, with long‐term modes of climate variability have been hard to assess because they are not well represented in current climate models. Here we stratify a satellite climatology of convective systems by El Niño phase and cloud top temperature. We find that gains (losses) in high precipitation intensity ( 10 mm hr−1) are largest for the deepest (least deep) systems during El Niño relative to La Niña. The surface temperature and wind changes that define El Niño manifest as surface flux changes but are not sufficient to explain these trends. We explore also the dynamical component of precipitation generation with a vertical momentum budget. Midtropospheric drying in the vicinity of the deepest systems boosts instability and ascent rates during El Niño, while the strengthened large‐scale ascent minimizes the drag force on their updrafts.

A Novel Application of Elliptic Curves in the Dynamical Components of Block Ciphers

The proposed work deals with a distinguished application of complex algebraic-geometric structure in nonlinear dynamical components of block ciphers. Due to the complex algebraic structure of the elliptic curves, their application in public-key cryptography has gained immense importance in recent years. The presented study introduces an effective application of elliptic curves in the nonlinear components, used in a symmetric-key cryptosystem. We propose that the group law defined on the rational points of an elliptic curve, over the binary field, offers extra-ordinary technical advantages, when used in the byte substitution process in block ciphers. For this purpose a specific elliptic curve over the Galois field $${\mathbb {F}}_{2^{4}}$$ is selected that is special as its elliptic group is of the same order as that of $${\mathbb {F}}_{2^{4}}$$ . This feature helps us defining a bijective map between the two structures that renders highly increased level of perplexity and confusion in data. The cryptographic forte of the proposed method is tested through most significant analyses and when compared with one of the most recent schemes, it shows outstanding results.

Default count-based network models for credit contagion

Interconnectedness between economic institution and sectors, already recognised as a trigger of the great financial crisis in 2008–2009, is assuming growing importance in financial systems. In this article, we study contagion effects between corporate sectors using financial network models, in which the significant links are identified through conditional independence testing. While the existing financial network literature is mostly focused on Gaussian processes, our approach is based on discrete data. We indeed test dependence in the conditional mean (and volatility) of default counts in different economic sector estimated from Poisson autoregressive models, and in their shocks. Our empirical application to Italian corporate defaults in the 1996–2018 period reveals evidence of a high inter-sector vulnerability, especially at the onset of the global financial crisis in 2008 and in the following years. Many contagion effects between corporate sectors are indeed found in the shock component of the default count dynamics.

Age-structured vectorial capacity reveals timing, not magnitude of within-mosquito dynamics is critical for arbovirus fitness assessment

BackgroundTransmission dynamics of arboviruses like Zika virus are often evaluated by vector competence (the proportion of infectious vectors given exposure) and the extrinsic incubation period (EIP, the time it takes for a vector to become infectious), but vector age is another critical driver of transmission dynamics. Vectorial capacity (VC) is a measure of transmission potential of a vector-pathogen system, but how these three components, EIP, vector competence and vector age, affect VC in concert still needs study.MethodsThe interaction of vector competence, EIP, and mosquito age at the time of infection acquisition (Ageacquisition) was experimentally measured in an Aedes aegypti-ZIKV model system, as well as the age-dependence of probability of survival and the willingness to bite. An age-structured vectorial capacity framework (VCage) was then developed using both EIPMin and EIPMax, defined as the time to first observed minimum proportion of transmitting mosquitoes and the time to observed maximum proportion of transmitting mosquitoes.ResultsThe within-mosquito dynamics of vector competence/EIP were not significant among treatments where mosquitoes were exposed at different ages. However, VCage revealed: (i) age-dependence in vector-virus interactions is important for transmission success; (ii) lower vector competence but at shorter EIPs was sufficient for transmission perpetuation; and (iii) R0 may be overestimated by using non-age-structured VC.ConclusionsThe results indicate that ultimately the temporal component of the virus-vector dynamics is most critical, especially when exposure occurred at advanced mosquito age. While our study is limited to a single virus-vector system, and a multitude of other factors affect both vector competence and mosquito mortality, our methods can be extrapolated to these other scenarios. Results indicate that how ‘highly’ or ‘negligibly’ competent vectors are categorized may need adjustment.