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Response to animal disease has importance for domestic supply and demand, trade implications, and other economic factors. Stamping out is effective at eradicating disease but requires resource investments that may be prohibitive in large-scale animal production systems. Alternative management strategies in a 50,000-head cattle feedlot are examined. Sample feedlot and epidemiological data are utilized for a discrete programming model. We analyze 14 scenarios across five management strategies under stochastic cattle prices and static disease management costs. Results show that targeted depopulation is a preferred method for the overall feedlot. [ABSTRACT FROM AUTHOR]

We study an avascular spherical solid tumour model with cell physiological age and resource constraints in vivo. We divide the tumour cells into three components: proliferating cells, quiescent cells and dead cells in necrotic core. We assume that the division rate of proliferating cells is nonlinear due to the nutritional and spatial constraints. The proportion of newborn tumour cells entering directly into quiescent state is considered, since this proportion can respond to the therapeutic effect of drug. We establish a nonlinear age-structured tumour cell population model. We investigate the existence and uniqueness of the model solution and explore the local and global stabilities of the tumour-free steady state. The existence and local stability of the tumour steady state are studied. Finally, some numerical simulations are performed to verify the theoretical results and to investigate the effects of different parameters on the model.

Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Resource demand by soil microorganisms critically influences microbial metabolism and then influences ecosystem resilience and multifunctionality. The ecological remediation of abandoned tailings is a topic of broad interest, yet our understanding of microbial metabolic status in restored soils, particularly at the aggregate scale, remains limited. This study investigated microbial resources within soil aggregates from revegetated tailings and applied a vector model of ecoenzymatic stoichiometry to examine how different vegetation patterns (grassland, forest, or bare land control) impact microbial resource limitation. Five-year vegetation restoration significantly elevated carbon (C) and nitrogen (N) concentrations and their stoichiometric ratios in soil aggregates (approximately 2-fold), although these increases were not translated to in the microbial biomass and its stoichiometry. The activities of C- and phosphorus (P)-acquiring extracellular enzymes in these aggregates increased substantially postvegetation, with the most pronounced escalation in macroaggregates (>0.25 mm). The vector model results indicated soil microbial metabolism was colimited by C and P, most acutely in microaggregates (<0.25 mm). This colimitation was exacerbated by monotypic vegetation cover but mitigated under diversified vegetation cover. Soil nutrient stoichiometric ratios in vegetation restoration controlled microbial resource limitation, overshadowing the impact of heavy metals. Our findings underscore that optimizing resource allocation within soil aggregates through strategic revegetation can enhance microbial metabolism in tailings, which advocates for the implementation of diverse vegetation covers as a viable strategy to improve the ecological development of degraded landscapes.

Breast cancer care is a costly global health issue where effective management depends on early detection and treatment. A breast cancer diagnosis can result in financial catastrophe especially in low- and middle-income countries (LMIC). Large inequities in breast cancer care are observed and represent a global challenge to caregivers and patients. Strategies to improve early diagnosis include awareness and clinical breast examination in LMIC, and screening in high-income countries (HIC). The use of clinical guidelines for the management of breast cancer is needed. Adapted guidelines from HIC can address disparities in populations with limited resources. Locally developed strategies still provide effective guidance in improving survival. Integrated practice units (IPU) with timely multidisciplinary breast care conferences and patient navigators are required to achieve high-value, personalized breast cancer management in HIC as well as LMIC. Breast cancer patient care should include a quality of life evaluation using ideally patient-reported outcomes (PROM) and experience measurements (PREM). Evaluation of breast cancer outcomes must include the financial cost of delivered care. The resulting value perspective should guide resource allocation and program priorities. The value of care must be improved by translating the findings of social and economic research into practice and resolving systemic inequity in clinical breast cancer research. Cancer survivorship programs must be put in place everywhere. The treatment of patients with metastatic breast cancer must require more attention in the future, especially in LMIC., (© The Author(s) 2024. Published by Oxford University Press.)

Healthcare provision takes place in a variety of contexts, with variations of resources available to practitioners and their patients. Effects from the COVID-19 pandemic superimposed on existing system demands have driven increasing concern about resource limitations, particularly in rural and remote settings. This article explores the legal liability of medical practitioners and healthcare services with respect to actions in negligence arising from harm to patients suffered, either partly or wholly, as a result of resource limitations., (© 2024 The Author(s). Internal Medicine Journal published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Physicians.)

Currently, more than 600 million people worldwide are diagnosed with COVID-19, while the implication of Tuberculosis cannot be ignored. The combination of COVID-19 and Tuberculosis exacerbates the catastrophe, dealing a serious blow to the healthcare system. This paper addresses how to develop effective and reasonable programs to combat the spread of COVID-19 and Tuberculosis in the absence of Tuberculosis medical resources, as well as exploring the impact of medical resources on optimal control implementation. Therefore, a co-infection dynamic of COVID-19 and Tuberculosis is constructed and analyzed. In order to investigate approaches to mitigate the disease transmission, a comprehensive and integrated study including sensitivity analysis, optimal control design and cost-effectiveness analysis is then performed. The simulation results illustrate that, the combination of the three control measures effectively achieves a win-win result in economic and epidemiological terms. In addition, the impact of Tuberculosis medical resources is highlighted, and the study shows that an appropriate increase in the medical resource supply for Tuberculosis during optimal control can have a stronger inhibitory effect on co-infection. Finally, based on the actual data, the model is validated by fitting the cumulative confirmed case curves of the two diseases. [ABSTRACT FROM AUTHOR]

This research was conducted with the aim of providing a chicken supply chain model based on challenges, success factors and human resource limitations. The information required for the research was collected from 15 experts and managers of poultry farms of Behparvor Group in the whole country and their opinions were obtained through interpretive structural modeling (ISM) interviews with a qualitative approach. In this research, using interpretive structural modeling, an integrated model for the chicken supply chain based on challenges, success factors and human resource limitations was designed. The results of interpretative structural modeling in this research showed the challenges of human resources with the dimensions of not paying attention to employee training, competitors' attempts to attract the company's experts, the nature of hard work, the inability to retain the company's experts, employees' resistance to change and leaving the job. Expert employees of the company as negative factors of the optimal supply chain of chicken production and also, the success factors of human resources with the dimensions of employee training, employee empowerment, employee welfare, job justice, financial justice and attracting and retaining employees as positive factors of the optimal supply chain of chicken production, along with the limitations of human resources with the dimensions of the lack of specialized labor in the labor market, the supply of labor by non-specialists and the lack of financial resources to attract specialized labor as negative factors of the optimal supply chain of chicken production constitute the integrated model of the chicken supply chain based on human resources. [ABSTRACT FROM AUTHOR]

While scholars have explored how focal firms harness demand-side value through ecosystem development, less emphasis has been placed on understanding how peripheral complementors become competitive. Unlike focal firms, complementors can seldom set value extraction rules. How can complementors lacking critical supply-side resources establish themselves as ecosystem leaders? We conducted a longitudinal analysis of Xiaomi, which began life as a smartphone software complementor within the Android ecosystem but ultimately gained architectural control by orchestrating the creation of a derivative ecosystem. We elucidate how these resource-disadvantaged firms may begin with fueling an "identity movement" among underserved users centered around a pivotal "foothold resource." This movement serves as their entry point into an ecosystem and enables them to build a demand-side community. They then employ "demand pull" as concrete evidence to substantiate their vision, coalesce supply-side resources, and ultimately become an orchestrator. While conventional strategy research emphasizes supply-side resources as drivers of value creation, we explore the synergy between demand-side mobilization and supply-side orchestration. Finally, we illustrate how firms lacking resources craft compelling visions in conjunction with substantive actions to engage evolving target audiences. This approach allows them to secure more advantageous positions within the ecosystem, thereby transforming its structure over time. [ABSTRACT FROM AUTHOR]

Organism growth is often determined by multiple resources interdependently. However, growth models based on the Droop cell quota framework have historically been built using threshold formulations, which means they intrinsically involve single-resource limitations. In addition, it is a daunting task to study the global dynamics of these models mathematically, since they employ minimum functions that are non-smooth (not differentiable). To provide an approach to encompass interactions of multiple resources, we propose a multiple-resource limitation growth function based on the Droop cell quota concept and incorporate it into an existing producer–grazer model. The formulation of the producer’s growth rate is based on cell growth process time-tracking, while the grazer’s growth rate is constructed based on optimal limiting nutrient allocation in cell transcription and translation phases. We show that the proposed model captures a wide range of experimental observations, such as the paradox of enrichment, the paradox of energy enrichment, and the paradox of nutrient enrichment. Together, our proposed formulation and the existing threshold formulation provide bounds on the expected growth of an organism. Moreover, the proposed model is mathematically more tractable, since it does not use the minimum functions as in other stoichiometric models.

Decision making within the context of resource limitations requires balancing the short-term benefits of obtaining a resource and the long-term consequences of depleting those resources. The present manuscript focuses on four types of tasks that share this tradeoff to develop a taxonomy that will encourage a deeper understanding of the psychological processes at play. The four types considered are foraging, common pool traps, deterioration traps, and a novel designation referred to as resource cliffs. All four will be shown to include two opposite processes - depletion of the resource and its replenishment over time. By considering the unique and shared features of these tasks, a taxonomy of features emerges that can be combined to not only create novel tasks but also to shift the research focus to task features rather than specific tasks. The paper closes with a consideration of current theoretical frameworks previously applied to one or more of these resource-limitation tasks as well as the promise of reinforcement learning as a unifying theory., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Fimbristylis miliacea is becoming a major rice weed in South and Southeast Asia. An understanding of how this weed species competes with rice and how to manage this weed under multiple resource limitations the development of cultural methods is important. Therefore, a study was conducted in greenhouse to determine the effect of varying rice seeding densities (0, 8, and 32 plants pot−1), nitrogen (N) rates (100 and 150 kg ha−1), and water regimes (aerobic and saturated) on rice and F. miliacea growth characteristics and competitiveness under multiple resource limitations under dry-seeded conditions. Both rice and weed were taller in saturated conditions than in aerobic conditions, whereas rice plants were taller than F. miliacea in both water regimes. F. miliacea grown alone had lower leaf and tiller number and less leaf, stem, shoot, root and inflorescence, biomass under saturated conditions than in aerobic conditions. However, when F. miliacea was grown with competition of rice, water regimes did not affect its growth parameters and inflorescence biomass production. N rates affected Rice growth but F. miliacea was not affected. Regardless of water regime and N rate, F. miliacea height (56 and 82%), tiller number (87 and 87%), leaf number (68 and 88%), shoot biomass (98 and 99%), inflorescence biomass (95 and 99.5%), and whole plant biomass (95 and 96%) decreased at rice densities of 160 and 640 plants m−2, compared with F. miliacea grown alone. The results suggest that growth and seed production of F. miliacea can be greatly declined by increasing rice planting density. [ABSTRACT FROM AUTHOR]

Abstract Nutrient and water limitations contribute to yield losses in semi-arid regions. Therefore, crop rotations incorporating nitrogen-fixing legumes and drought-tolerant sorghum varieties offer a strategy to improve the utilization of scarce soil resources. Under semi-arid, field-like conditions, sorghum crop rotations with either cowpea pre-crop or fallow, including two early and three late maturing genotypes, were tested to identify stress adaptation traits of sorghum to water and phosphorus limitations. Morphological and physiological parameters were evaluated on a single-plant basis. Lower soil P content significantly delayed flowering compared to higher P levels. However, improved P availability arising from pre-crop residues reduced this effect. Mycorrhizal infection rates and root-to-shoot ratios were positively correlated with panicle N and P content at anthesis under low P conditions. Although drought significantly impacted yield, early maturing genotypes with the highest reduction in shoot biomass and reduced water use before flowering, could sustain yield production. Early-maturing genotypes characterized by high root-to-shoot ratios, rapid AMF establishment, and reduced water use before flowering exhibit a strong potential for maintaining yield and biomass production on nutrient-poor soils in semi-arid regions. Such genotypes conserve water before flowering and thus can alleviate post-flowering water stress, ensuring adequate P uptake despite low soil P availability.

Assessing the limitations of microbial metabolic resources is crucial for understanding plantation soil quality and enhancing fertility management. However, the variation of microbial resource limitations at the aggregate level in response to changes in stands remains unclear. This research explores carbon (C), nitrogen (N), and phosphorus (P) limitations affecting microbial metabolism in bulk soils and aggregates in two mixed and one pure Chinese fir stands in subtropical China, analyzing resource limitations concerning soil carbon, nutrients, and microbial indicators. The results revealed that microbes in all aggregates of the pure stands and in the micro aggregates (<0.25 mm) of the three stands were relatively limited by C and P. In contrast, microbial metabolism was more N-limited in macroaggregates (>2 mm) and small aggregates (2–0.25 mm) in the mixed stands. Additionally, in the mixed stands the proportion of soil macroaggregates increased, and that of micro aggregates decreased, resulting in a shift from C and P limitation to N limitation for bulk soil microbial metabolism. Redundancy analysis identified soil aggregate organic carbon and nutrient content as the main factors affecting microbial resource limitation, rather than their stoichiometric ratios. Pathway analysis further confirmed that soil nutrients and their stoichiometric ratios indirectly influenced soil microbe resource limitation by regulating microbial biomass, microbial respiration, and extracellular enzyme activities. Thus, the impact of mixed plantations on soil nutrients and microbial activity at the aggregate level may be crucial for maintaining land fertility and achieving sustainability. [ABSTRACT FROM AUTHOR]