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Context: Various patterns of dynamic routing architectures are used in service- and cloud-based environments, including sidecar-based routing, routing through a central entity such as an event store, or architectures with multiple dynamic routers. Objective: Choosing the wrong architecture may severely impact the reliability or performance of a software system. This article’s objective is to provide models and empirical evidence to precisely estimate the reliability and performance impacts. Method: We propose an analytical model of request loss for reliability modeling. We studied the accuracy of this model’s predictions empirically and calculated the error rate in 200 experiment runs, during which we measured the round-trip time performance and created a performance model based on multiple regression analysis. Finally, we systematically analyzed the reliability and performance impacts and trade-offs. Results and Conclusions: The comparison of the empirical data to the reliability model’s predictions shows a low enough and converging error rate for using the model during system architecting. The predictions of the performance model show that distributed approaches for dynamic data routing have a better performance compared to centralized solutions. Our results provide important new insights on dynamic routing architecture decisions to precisely estimate the trade-off between system reliability and performance.

Funding: The field study was funded mainly by NERC (NE/R011109/1 and NE/R016801/1) and the ERC (AdG 250098) funded much of the SNP genotyping. The SNP genotyping was carried out at the Wellcome Trust Clinical Research Facility Genetics Core, Edinburgh and Jisca Huisman carried out the pedigree reconstruction. Life history trade-offs are ubiquitous across species and place constraints on the timing of life history events, including the optimal age at first reproduction. However, studies on lifetime breeding success of male mammals are rare due to sex-biased dispersal and the requirement for genetic paternity inferences. We studied the correlates and apparent fitness consequences of early life reproduction among males in a free-living population of Soay sheep (Ovis aries) on St Kilda, Scotland. We investigated the factors associated with early breeding success and the apparent consequences of early success for survival and future reproduction. We used genetic paternity inferences, population data, and individual morphology measurements collected over 30 years. We found that individuals born in years with low-density population size had the highest early life breeding success and singletons were more likely to be successful than twins. Individuals that bred successfully at 7 months were more likely to survive their first winter. For individuals that survived their first winter, early breeding success was not associated with later breeding success. As individual heterogeneity affects breeding success, we believe that variation in individual quality masks the costs of early reproduction in this population. Our findings provide no evidence for selection for delayed age at reproduction in male Soay sheep. Publisher PDF

Epiphyte communities comprise important components of many forest ecosystems in terms of biomass and diversity, but little is known regarding trade-offs that underlie diversity and structure in these communities or the impact that microclimate has on epiphyte trait allocation. We measured 22 functional traits in vascular epiphyte communities across six sites that span a microclimatic gradient in a tropical montane cloud forest region in Costa Rica. We quantified traits that relate to carbon and nitrogen allocation, gas exchange, water storage, and drought tolerance. Functional diversity was high in all but the lowest elevation site where drought likely limits the success of certain species with particular trait combinations. For most traits, variation was explained by relationships with other traits (trait co-variance), rather than differences in microclimate across sites. Although there were significant differences in microclimate, epiphyte abundance, and diversity, we found substantial overlap in multivariate trait space across five of the sites. We found significant correlations between functional traits, many of which related to water storage, drought tolerance, and carbon allocation. This suite of trait correlations suggests that the epiphyte community has evolved functional strategies along a drought avoidance versus drought tolerance continuum where leaf succulence emerged as a pivotal overall trait.

Differences in ecosystem service (ES) priorities often lead to conflicts between stakeholders. While differences in priorities have often been described, the sociocultural factors, including differences in cultural worldview, which drive them have not. We propose that the cultural theory of risk and its ‘grid‐group’ typology, which classifies people as individualists, hierarchists, egalitarians and fatalists, can provide a conceptual framework for doing this. We examined the relationship between ES prioritisation by stakeholders and underlying cultural (cultural worldviews, and related environmental nature and risk perceptions), sociocultural (region, stakeholder group, political party preference) and socio‐demographic factors. This was achieved by applying multivariate statistics to data from a survey with 321 respondents, conducted across 14 stakeholder groups in three German regions. Results show that most stakeholders prioritised many services but gave the highest priority to services linked to their stakeholder group. We identified four ‘ES priority bundles’: cultural services, open‐land provisioning services, environmental protection services and forest provisioning services. Each ES priority bundle was consistently associated with particular cultural worldviews, perceptions of nature and sociocultural factors, meaning that we could identify ‘cultural types’. Two of these associations were particularly strong: Prioritisation of open‐land provisioning ES was high for the agriculture stakeholder group, associated with individualism, a perception of nature as durable but unpredictable, and support for economic liberal, conservative political parties. In contrast, those who prioritised environmental protection tended to hold egalitarian cultural worldviews and perceive nature as tolerant and sensitive. They also often belonged to the research and nature conservation stakeholder groups, with a mostly left‐leaning political party preference. The identification of cultural types of stakeholder with consistent ES priorities and cultural worldviews may provide a useful construct in the future ES research. Furthermore, it may allow communications regarding ES to be tailored to improve their effectiveness, potentially aiding the promotion of sustainable management strategies. A free Plain Language Summary can be found within the Supporting Information of this article.

Negotiating parties to an environmental agreement can manage uncertainty by including flexibility clauses, such as escape and withdrawal clauses. This article investigates a type of uncertainty so far overlooked by the literature: the uncertainty generated by the creation of a Conference of the Parties (COP) in a context of sharp power asymmetry. When negotiating an agreement, it is difficult for powerful states to make a credible commitment to weaker states, whereby they will not abuse their power to influence future COP decision-making. Flexibility clauses provide a solution to this credibility issue. They act as an insurance mechanism in case a powerful state hijacks the COP. Thus we expect that the creation of a collective body interacts with the degree of power asymmetry to make flexibility clauses more likely in environmental agreements. To test this argument, we draw on an original data set of several specific clauses in 2,090 environmental agreements, signed between 1945 and 2018. The results support our hypothesis and suggest that flexibility clauses are an important design feature of adaptive environmental agreements.

Privatizations of state-owned enterprises are associated with significant gains in efficiency post-privatization, born from both exposure to product market competition and improved managerial incen...

Legionella pneumophila are bacteria that when inhaled cause Legionnaires' disease (LD) and febrile illness Pontiac fever. As of 2014, LD is the most frequent cause of waterborne disease outbreaks due to drinking water exposure in the United States. The optimal temperature for the bacteria's growth is between 25–45 °C, and water heaters that are set within this range can become an environment for L. pneumophila to grow. The recommended water heater temperature varies across organizations, from 60 °C to kill L. pneumophila bacteria to 49 °C to prevent scalding and minimize energy costs. To evaluate these trade-offs, we have developed a computational framework for evaluating an optimal water heater temperature set point for reducing cost and health risks. This framework uses a quantitative microbial risk assessment (QMRA) to assess the risk of infection from a single shower aerosol exposure in terms of disability-adjusted life years (DALY) and costs. The model demonstrated that the optimal water heater temperature set point for reducing cost and health risks was 55 °C or 48 °C for a common configuration of an electric water heater used in a hospital setting, using a subclinical infection or clinical severity infection dose response model, respectively. Based on these preliminary results, we expect this modeling framework will be able to provide useful insight into the optimal water heater temperature set point for hospitals based on their specific premise plumbing system configurations and constraints and can inform computational tools used to make site-specific decisions.

This research aimed to study the approach of the community toward the decision to grow rice and economic crops, including appropriate resource allocation for use on a farm under a large plot agricultural system. The study areas were in Phan district, Chiang Rai province, Thailand, and the data were collected from a sampling of 400 field agriculturalists. The method used was to develop a mathematical model for growing crops with multi-objectives and in multi-periods, together with an agriculturist representative and experts in multiple-criteria decision-making (MCDM). This was to prioritize the importance of alternative crops and find the appropriate allocation of the resources to achieve the targeted goal. The results showed that agriculturists prioritized most toward the criteria for growing Japanese rice with a weight of 0.179 Kg., followed by transplanted rice, transplanted glutinous rice, garlic, sown paddy rice, and sown glutinous paddy rice, respectively. The study’s results also showed that the price fluctuation of the crop products resulted in more use of land and labor in order to increase the production to compensate for the low price, and this also resulted in the higher opportunity cost of growing transplanted rice. Therefore, growing transplanted rice during in season planting was considered the most effective way, while during the off season, either garlic or Japanese rice could be grown. A collective pattern for planning for using resources together in large plot agricultural areas, together with a clear marketing target would bring about effective use of the resources and reduce the risk in revenue from the fluctuation in prices and uncertainty of yields from drought. Moreover, technology development to solve the problem of the lack of labor would be deemed an important approach toward the enhancement of the competitiveness of agriculturists in the future as well.

Ecosystem managers confronted with newly invasive species may respond with a program of suppression or eradication. Suppression of an invasive species refers to management of a species such that its effect on other biota in the local ecosystem is acceptable. Eradication is the removal of all individuals of a species from a defined region. We examine the cost and benefit trade-offs between suppression and eradication of Laurentian Great Lakes sea lampreys (Petromyzon marinus) based on discussions at the 3rd Sea Lamprey International Symposium (held in 2019). Substantial effort has been expended annually since the 1960s to suppress sea lampreys in the Great Lakes basin. Choosing between suppression and eradication is a value judgement, ideally made jointly by scientists, decision-makers, stakeholders, and society. Successful large-scale eradications have been limited to a small number of cases for which the cost to human society justified and supported the long-term commitment necessary for success. The greatest challenge to successful eradication of sea lampreys from the Great Lakes may be a suitable social, political, legal, and institutional environment. Preparations could be made now for a transition in which public pushback on current control methods (pesticide applications and barriers to fish passage) leads to more extensive use of an alternative control method, such as genetic control.

Little is known about limits to reproduction in plants, especially as to how their other life history functions (growth and defense) may constrain reproductive investment. Understanding these constraints can help researchers refine best practices for cultivating species like Rubus (Rosaceae) that produce nutritious fruits as well as for controlling invasive species. Here, we sought to elucidate potential trade-offs between growth, defense, and reproduction in native Rubus allegheniensis Porter (common blackberry) and invasive Rubus phoenicolasius Maxim. (wineberry) while accounting for the effects of varying insect herbivory and resource availability levels. We observed traits related to physical defense (e.g., prickle intensity), growth (e.g., cane length), and floral reproduction (e.g., ripe fruits), as well as carbon availability (e.g., canopy cover). We then used multiple regressions to characterize relationships between these variables for both species. We found potential evidence for 2 induced defenses in the invasive wineberry. Also, 5 models returned significant results indicative of trade-offs between reproduction and growth, reproduction and defense, and defense and growth in a single or both species. Our results highlight the importance of understanding the defensive strategies utilized by these species because inducible defenses may result in trade-offs that could reduce yields and (or) increase the invasive potential of Rubus species.

Life-history theory posits that investment into reproduction might occur at the expense of investment into somatic maintenance, including immune function. If so, reduced or curtailed reproductive effort might be expected to increase immunity. In support of this notion, work in Caenorhabditis elegans has shown that worms lacking a germline exhibit improved immunity, but whether the antagonistic relation between germline proliferation and immunity also holds for other organisms is less well understood. Here, we report that transgenic ablation of germ cells in late development or early adulthood in Drosophila melanogaster causes elevated baseline expression and increased induction of Toll and Imd immune genes upon bacterial infection, as compared to fertile flies with an intact germline. We also identify immune genes whose expression after infection differs between fertile and germline-less flies in a manner that is conditional on their mating status. We conclude that germline activity strongly impedes the expression and inducibility of immune genes and that this physiological trade-off might be evolutionarily conserved.

Modelling fertility decline in post-industrial populations in the context of life history theory has allowed us to better understand the environmental pressures that shape reduced family size. One such pressure, which has received relatively little attention from ecologists, is the movement of women into the labour market. Analyses of effects of employment on fertility in contemporary developing or post-demographic transition populations are limited by the widespread use of modern contraceptives: while uptake of these methods may be a mechanism by which reduced fertility is enacted, their use may obscure effects of employment on fertility. Here, we investigated the impact of women’s employment on family size during a period of the movement of women into the workforce but prior to the use of modern contraceptives. We analysed the effects of women’s employment on family size using census records from 1901 for a regional-level analysis of parishes in Scotland, and for 1851–1901 for an individual-level analysis of the Scottish city of Dundee. Women in employment had fewer children than those not in employment. Income was inversely related with family size, and this was independent of the effects of women’s employment on family size. We suggest that female employment contributes to the evolution of smaller family sizes and that this takes place in the context of prevailing and emerging gender roles, and in interaction with opportunities for employment and wealth.

Coaching is an increasingly used professional development approach involving ongoing, individualized teacher-coach exchanges hypothesized to drive immediate changes in teachers’ practices with students. Examining this hypothesis, the present study quantifies marginal changes after individual coaching cycles in a set of commonly considered, high-quality teacher practices using a teacher fixed effects approach. It draws on panel data from 169 early childhood educators participating in a 9-month coaching intervention using the MyTeachingPartner approach intended to improve practices outlined in the Teaching Through Interactions framework. Results indicated that emotional support and classroom organization practices improved immediately after any coaching cycle, whereas others, like instructional support and literacy focus practices, only changed after cycles focused on those specific practices. Some immediate postcycle differences in practices endured over time, whereas others dissipated quickly.

The Cauvery basin in southern India is experiencing transboundary issues due to increasing water demand. This study analysed water balance components and the impact of agricultural water management (AWM) interventions in the upper Cauvery catchment of the Cauvery basin. Results showed that the study catchment receives an average of 1280 mm of annual rainfall. Of this, 29% (370 mm) flows downstream, 54% (700 mm) contributes to evapotranspiration (ET) and 17% (215 mm) contributes to groundwater recharge and surface storage. Rainfall varies from 700 to 5400 mm and the Western Ghats (mountain pass) are the main source of freshwater generation. The estimated ET in different catchments ranged from 500 to 900 mm per annum. An increase in the allocation of fresh water supplied by all three reservoirs (Hemavathi, Harangi and KRS) was observed in the canal command areas, from 1450 million cubic metres (MCM) yr‾¹ in 1971–1980 to 3800 MCM yr‾¹ in 2001–2010. AWM interventions harvested 140–160 MCM (13–20 mm) of surface runoff upstream of the upper Cauvery and reduced inflow into the Krishnaraja Sagar reservoir by 2–6%. The study findings are useful for designing and planning suitable water management interventions at basin scale.

The trade-offs between tree growth and mortality are important indicators of the life-history strategies of species and have been demonstrated to be maintained by inherent fitness differences among species. There is a growing consensus that functional traits which inflect the ecological performances of individuals may be correlated with growth–mortality trade-offs within communities. In this study, the aforementioned trade-offs were detected and their relationships with the functional traits were examined, based on data collected in a typical temperate forested area in northeastern China. Principal components analyses were performed for growth–mortality trade-off relationships. The factor scores on the first principal component were used to represent the species’ positions at an axis of life-history variations among different species. Correlation and multiple regression analyses were performed for the purpose of detecting the relationships between functional traits and the growth–mortality trade-off. The results showed that there were significant trade-offs between the tree growth and mortality rates in the examined plot. Among the six functional traits which were considered, the Hmax was found to have the strongest effects on the demographic rates and trade-offs. The observed negative effects on the tree growth and mortality rates suggested that the large species often grow more slowly and living longer, while species at small adult size grow fast but die easily. It was also observed that the specific leaf area and the leaf carbon content level were also very important to the growth and mortality trade-offs. The traits considered in this study explained 68% of interspecific variations in the species positions in the growth–mortality trade-off. In addition, wood density was found to show no effect on the trade-off. This was likely due to the fact that the density of the wood may influence the demographic rates more strongly during the early life stages of the trees. The results of discrimination analysis further confirmed the explanations abilities of the functional traits on the variations of life-history strategies among the species. Due to the fact that the relationships between the functional traits and the trade-offs were found to be relatively variable, it will be necessary to further consider other traits which are more closely and mechanistically linked to individual performances in future investigations, such as leaf life span, leaf tissue density, photosynthetic capacity, and dark respiration rates.

In this short article, I summarize recent research in economic history that suggests long-run institutional trade-offs in public health that affect both health and economic outcomes. These trade-offs suggest that a long timespan is necessary to fully measure the consequences of heavy-handed public health interventions. This timespan means that those who have declared “victory” or “defeat” in the wake of COVID policy are premature. Modesty in terms of policy evaluation and prescription is still warranted.

We see stunning morphological diversity across the animal world. Less conspicuous but equally fascinating are the sensory and cognitive adaptations that determine animals’ interactions with their environments and each other. We discuss the development of the fields of sensory and cognitive ecology and the importance of integrating these fields to understand the evolution of adaptive behaviors. Bats, with their extraordinarily high ecological diversity, are ideal animals for this purpose. An explosion in recent research allows for better understanding of the molecular, genetic, neural, and behavioral bases for sensory ecology and cognition in bats. We give examples of studies that illuminate connections between sensory and cognitive features of information filtering, evolutionary trade-offs in sensory and cognitive processing, and multimodal sensing and integration. By investigating the selective pressures underlying information acquisition, processing, and use in bats, we aim to illuminate patterns and processes driving sensory and cognitive evolution.

Our objective was to study performance trade-offs in elite athletes competing in a multi-event sport requiring a combination of aptitudes that might conflict each other. Swimmers competing in the individual medley, in particular, might face trade-offs as they have to swim (in this specific order) a quarter of the distance in butterfly, backstroke, breaststroke, and freestyle within a single race. We applied multivariate mixed models to analyse 28 years (1991–2019) of publicly available data on men (N = 121) and women (N = 131) swimmers competing for the 200 m individual medley in the semi-final and final rounds of Olympics and world championships. At the among-individual level, performance in the backstroke and breaststroke were negatively correlated in both men (rind = −0.264 ± 0.126) and women (rind = −0.453 ± 0.103). At the within-individual level, there was a negative correlation between performance in the first and final 50 m of the race in men (re = −0.181 ± 0.055), but not in women (re = 0.001 ± 0.058). To our knowledge, this is the first demonstration of a trade-off between backstroke and breaststroke swimming styles. Such a trade-off might be caused by various extrinsic (e.g., allocation of training time across the four strokes) and intrinsic (e.g., body morphology and muscle physiology) constraints on human performance. The difference in the pattern of within-individual correlations between men and women aligns with pacing strategies described in the literature. Further research is required to better understand the nature of the trade-offs detected here, which could potentially help improving training strategies for the “generalist” individual medley swimmer.

We propose two analytical models to characterize the relationship between technological upgrading and innovation in the oil & gas industry. The first one is an “optimization model” which focuses on the trade-offs between profit maximization and environmental compliance cost. The other has been developed based on “predator-prey” model which captures the dynamics of biological systems. Our study contributes to the strategic planning process for sustainable development by providing the insight that optimal allocation process is determined by multiple operational factors, including a firm’s competitive ranking among its industrial competitors, industrial consent on the concurrent rate of return on capital investment, the projected demand of oil & gas in future, and a change in environmental compliance cost. Further, we add to the robustness of the optimal allocation process by providing binding conditions of the set of solutions.

Purpose Fears over public accounting becoming increasingly concentrated have inspired several attempts to study the relationship between competition and audit quality. These studies have yielded conflicting results without a clear reason as to why. This paper aims to propose a new approach and empirically demonstrate a non-monotonic association between competition and audit quality. Design/methodology/approach Using metropolitan statistical area level data from the USA over the period of 2000–2014, the author shows that the effect that changes in the competition will have on audit quality depends upon the current competitive state of the market. Findings Audit quality is at its highest level when competition is neither too high nor too low. In addition, the point of inflection at which competition turns from being helpful to harmful is influenced by the saturation of the Big 4 auditors in the market. Practical implications These findings can help explain the mixed results of the literature and provide insight into the role that regulators can play in modulating competition. Originality/value This is the first paper to document a non-monotonic relationship between competition and audit quality. By introducing and exploring the validity of a non-monotonic component in the audit quality equation, the authors can better determine, which competitive structures generate desired levels of audit quality.

In a recent paper, "Environmental DNA: What's behind the term? Clarifying the terminology and recommendations for its future use in biomonitoring," Pawlowski et al. argue that the term eDNA should be used to refer to the pool of DNA isolated from environmental samples, as opposed to only extra-organismal DNA from macro-organisms. We agree with this view. However, we are concerned that their proposed two-level terminology specifying sampling environment and targeted taxa is overly simplistic and might hinder rather than improve clear communication about environmental DNA and its use in biomonitoring. This terminology is based on categories that are often difficult to assign and uninformative, and it overlooks a fundamental distinction within eDNA: the type of DNA (organismal or extra-organismal) from which ecological interpretations are derived., Molecular Ecology, 30 (19), ISSN:0962-1083, ISSN:1365-294X

Non-orthogonal multiple access (NOMA) and full-duplex (FD) have recently emerged as a potential candidate for the fifth-generation and beyond (B5G) cellular networks with the target of increasing s...

Brokers play a critical role in the evolution of innovation systems by accessing and diffusing external knowledge. However, while brokers’ activity allows benefits for the entire system, it entails costs for those who play the broker role. Using patent data to analyse inter-city networks in Latin America, we identify broker cities and estimate the effects of brokerage on patenting outcomes between 2006 and 2017. Our findings reveal that cities holding a central position in the network show higher patenting activity; however, being a broker, particularly connecting Latin American cities with the rest of the world, negatively influences patenting outcomes.

Background: Home care workers help older individuals and those with disabilities with a variety of functional tasks. Despite their core role providing essential care to vulnerable populations, home care workers are often an invisible sector of the healthcare workforce. The transmission of COVID-19 and the nature of home care work raise several questions about the overall safety of these workers during the pandemic. Objective: To examine the experiences of home care workers during COVID-19, particularly their access to information about infection status, to testing, and to personal protective equipment (PPE); their understanding of guidelines; and trade-offs associated with protecting workers’ safety. Methods: A mixed methods study including qualitative analysis of guided discussion questions and quantitative analysis of multiple-choice survey questions was conducted. Eleven virtual focus groups in October and November 2020 involved 83 home care workers who care for clients/consumers in Massachusetts. Thirty-nine participants worked as personal care attendants (PCAs) employed directly by a consumer and 44 participants worked for an agency. Ninety percent self-identified as female and 54% had worked in home care for more than five years. Qualitative data was analyzed using thematic analysis, with identification of major and minor themes. Likert scale survey question data on perceptions of COVID-19 exposure, access to resources to prevent transmission, and perceptions of safety at work were dichotomized into agree or disagree. Results: PCAs and agency-employed home care workers were regularly faced with trade-offs between meeting client/consumer needs and protecting themselves from COVID-19 exposure. Twenty-five percent of participants reported serving a client/consumer who had COVID-19, 75% reported worrying about getting COVID-19 at work, and 29% reported thinking about stopping their work in home care. Despite a low pay structure, participants reported opting to risk exposure rather than to leave their clients/consumers without essential care. However, workers often lacked the resources (e.g., PPE, testing) to feel truly protected. This scarcity of resources combined with insufficient guidance and policies specific to home care settings led many workers to informally collaborate with clients/consumers to assess exposure risks and agree upon safety protocols. Focus group participants expressed uncertainty as to whether workers were truly empowered to ask for changes if conditions seemed unsafe. The burden of determining safety protocols was felt more strongly by PCAs who operate more independently than agency-employed workers who have supervisors to consult. Conclusions: Home care workers expressed deep commitment to continuing to care for their clients/consumers during COVID-19, but often had to operate with insufficient resources and under conditions that made their work environments feel unsafe. Their ability to identify exposure risks and make decisions on how to protect themselves often hinged on a transparent and trusting relationship with their clients/consumers. These relationships were particularly important for PCAs who did not have access to safety guidance from a home care agency.

Medium-density housing (MDH) is posited as a solution to providing greater housing affordability. Yet, higher-density housing is often considered unsuitable for children. Our study investigates the...

Environmental threats increasingly entail important risks from government responses. In considering the risks of a new vector-borne disease, for example, decision-makers must also grapple with potential risks from responses such as the aerial spraying of pesticides. In communicating about these complex risks, public officials often choose different “frames” that promote different conceptualizations of the issue. Yet prior research has paid limited attention to how public officials frame the related risks of the environmental threat and the public response. This paper starts to fill that gap by conducting a content analysis of statements by public officials regarding risks from the threat of a local outbreak of the Zika virus in South Florida in 2016, as well as risks from the response of aerial pesticide spraying. Based on limited prior research, we hypothesize that public officials are likely to have adopted a “risk maximization” frame that stressed the high risks from exposure to Zika, but a “risk trade-off” frame when discussing aerial spraying. In actuality, we find that officials strongly favored a “reassurance” frame that downplayed both types of risks. Based on this analysis, we suggest framing strategies for disease outbreaks and other threats with potentially risky government responses may vary significantly depending on local contexts and that the South Florida experience was a missed opportunity to test the strategy of trade-off framing.

This work is partially supported by the Hong Kong Research Grants Council (project numbers AoE/P-02/12 and C6023-19G) and the William Mong Institute of Nano Science and Technology (project number WMINTST19/SC04). A.S. also acknowledges the support from King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No: OSR-2019-CARF/CCF-3079.

Bacterial spot is an endemic seedborne disease responsible for recurring outbreaks on tomato and pepper around the world. The disease is caused by four diverse species, Xanthomonas gardneri, Xanthomonas euvesicatoria, Xanthomonas perforans, and Xanthomonas vesicatoria. There are no commercially available disease-resistant tomato varieties, and the disease is managed by chemical/biological control options, although these have not reduced the incidence of outbreaks. The disease on peppers is managed by disease-resistant cultivars that are effective against X. euvesicatoria but not X. gardneri. A significant shift in composition and prevalence of different species and races of the pathogen has occurred over the past century. Here, I attempt to review ecological and evolutionary processes associated with the population dynamics leading to disease emergence and spread. The goal of this review is to integrate the knowledge on population genomics and molecular plant–microbe interactions for this pathosystem to tailor disease management strategies.

Background A paucity of research addresses breast cancer screening strategies for women at lower-than-average breast cancer risk. The aim of this study was to examine screening harms and benefits among women aged 50-74 years at lower-than-average breast cancer risk by breast density. Methods Three well-established, validated Cancer Intervention and Surveillance Network models were used to estimate the lifetime benefits and harms of different screening scenarios, varying by screening interval (biennial, triennial). Breast cancer deaths averted, life-years and quality-adjusted life-years gained, false-positives, benign biopsies, and overdiagnosis were assessed by relative risk (RR) level (0.6, 0.7, 0.85, 1 [average risk]) and breast density category, for US women born in 1970. Results Screening benefits decreased proportionally with decreasing risk and with lower breast density. False-positives, unnecessary biopsies, and the percentage overdiagnosis also varied substantially by breast density category; false-positives and unnecessary biopsies were highest in the heterogeneously dense category. For women with fatty or scattered fibroglandular breast density and a relative risk of no more than 0.85, the additional deaths averted and life-years gained were small with biennial vs triennial screening. For these groups, undergoing 4 additional screens (screening biennially [13 screens] vs triennially [9 screens]) averted no more than 1 additional breast cancer death and gained no more than 16 life-years and no more than 10 quality-adjusted life-years per 1000 women but resulted in up to 232 more false-positives per 1000 women. Conclusion Triennial screening from age 50 to 74 years may be a reasonable screening strategy for women with lower-than-average breast cancer risk and fatty or scattered fibroglandular breast density.

We consider a heterogeneous distributed service system, consisting of $n$ servers with unknown and possibly different processing rates. Jobs with unit mean and independent processing times arrive as a renewal process of rate $\lambda n$, with $0, Comment: arXiv admin note: text overlap with arXiv:1807.02882