Efficient assembly and long-term stability of defensive microbiomes via private resources and community bistability

Understanding the mechanisms that promote the assembly and maintenance of host-beneficial microbiomes is an open problem. Empirical evidence supports the idea that animal and plant hosts can combine ‘private resources’ with the ecological phenomenon known as ‘community bistability’ to favour some microbial strains over others. We briefly review evidence showing that hosts can: (i) protect the growth of beneficial strains in an isolated habitat, (ii) use antibiotics to suppress non-beneficial, competitor strains, and (iii) provide resources that only beneficial strains are able to translate into an increased rate of growth, reproduction, or antibiotic production. We then demonstrate in a spatially explicit, individual-based model that these three mechanisms act similarly by selectively promoting the initial proliferation of preferred strains, that is, by acting as a private resource. The faster early growth of preferred strains, combined with the phenomenon of ‘community bistability,’ allows those strains to continue to dominate the microbiome even after the private resource is withdrawn or made public. This is because after a beneficial colony reaches a sufficiently large size, it can resist invasion by parasites without further private support from the host. We further explicitly model localized microbial interactions and diffusion dynamics, and we show that an intermediate level of antibiotic diffusion is the most efficient mechanism in promoting preferred strains and that there is a wide range of parameters under which hosts can promote the assembly of a self-sustaining defensive microbiome. This in turn supports the idea that hosts readily evolve to promote host-beneficial defensive microbiomes

An Analysis of Distributed Systems Syllabi With a Focus on Performance-Related Topics

We analyze a dataset of 51 current (2019-2020) Distributed Systems syllabi from top Computer Science programs, focusing on finding the prevalence and context in which topics related to performance are being taught in these courses. We also study the scale of the infrastructure mentioned in DS courses, from small client-server systems to cloud-scale, peer-to-peer, global-scale systems. We make eight main findings, covering goals such as performance, and scalability and its variant elasticity; activities such as performance benchmarking and monitoring; eight selected performance-enhancing techniques (replication, caching, sharding, load balancing, scheduling, streaming, migrating, and offloading); and control issues such as trade-offs that include performance and performance variability.Comment: Accepted for publication at WEPPE 2021, to be held in conjunction with ACM/SPEC ICPE 2021: https://doi.org/10.1145/3447545.3451197 This article is a follow-up of our prior ACM SIGCSE publication, arXiv:2012.0055

Weak-type boundedness of the Fourier transform on rearrangement invariant function spaces

We study several questions about the weak-type boundedness of the Fourier transform ℱ on rearrangement invariant spaces. In particular, we characterize the action of ℱ as a bounded operator from the minimal Lorentz space Λ(X) into the Marcinkiewicz maximal space M(X), both associated with a rearrangement invariant space X. Finally, we also prove some results establishing that the weak-type boundedness of ℱ, in certain weighted Lorentz spaces, is equivalent to the corresponding strong-type estimates

Comparison of a proprioceptive training program on stable base and unstable base

The aim is to compare two proprioceptive training programs on a stable (G1) and an unstable (G2) base in terms of balance and stability. During a 5 week period, 18 professional football players underwent a proprioceptive training program, 9 in G1 and the other 9 in G2. The Standard Excursion Balance Test was applied before and after the intervention program. Significant intragroup differences were found in the variables LEFT FRONT, ANTEROLATERAL LEFT (ANTLAT.LEFT), BACK RIGHT and ANTEROMEDIAL RIGHT (ANTMED.RIGHT) (p<0,005) for the G1, and FRONT RIGHT, FRONT LEFT, POSTMED.RIGHT, POSTMED.LEFT and MED.RIGHT (p <0,005) for G2. We conclude that there are no significant differences between the unstable base training and training stable base regarding improvement in balance and stability.Actividad Física y Deport

Restrictive ID policies: implications for health equity

We wish to thank Synod Community Services for their critical work to develop, support, and implement a local government-issued ID in Washtenaw County, MI. We also thank Yousef Rabhi of the Michigan House of Representatives and Janelle Fa'aola of the Washtenaw ID Task Force, Lawrence Kestenbaum of the Washtenaw County Clerk's Office, Sherriff Jerry Clayton of the Washtenaw County Sherriff's Office, and the Washtenaw ID Task Force for their tireless commitment to developing and supporting the successful implementation of the Washtenaw ID. Additionally, we thank Vicenta Vargas and Skye Hillier for their contributions to the Washtenaw ID evaluation. We thank the Curtis Center for Research and Evaluation at the University of Michigan School of Social Work, the National Center for Institutional Diversity at the University of Michigan, and the University of California-Irvine Department of Chicano/Latino Studies and Program in Public Health for their support of the Washtenaw ID community-academic research partnership. Finally, we thank the reviewers for their helpful comments on earlier drafts of this manuscript. (Curtis Center for Research and Evaluation at the University of Michigan School of Social Work; National Center for Institutional Diversity at the University of Michigan; University of California-Irvine Department of Chicano/Latino Studies; Program in Public Health)https://link.springer.com/content/pdf/10.1007/s10903-017-0579-3.pdfPublished versio

Acción de la protoveratrina en la producción láctea de cabras de raza granadina en stress térmico estival

Se estudia la acción de la protoveratina adicionada al pIenso en ca­bras granadinas en stress térmico estival. La técnica seguida es la de valor leche en tres lotes estabulados totalmente, con una ración basal de 650 g de veza y dos kilos de paja de habas. La dosis de alcaloide se adiciona en lres niveles, 5, 7 Y 10 mg por animal y día. Se concluye que la acción de a protoveratrina a la dosis de 10 mg diaria es muy significativa para combatir la disminución en la pro­ducción láctea debida a las altas temperaturas estivales. Esta signifi­cación se da tanto para el volumen de leche como para la cantidad de grasa de la misma.The action of protoveratin added to feed is studied in grenadine goats under summer heat stress. The technique followed is that of milk value in three batches fully housed, with a basal ration,? E 650 g vetch and two kilos of broad bean straw. The alkaloid dose is added in three levels, 5, 7 and 10 mg per animal and day. It is concluded that the action of a protoveratrin at the dose of 10 mg. daily is very significant to combat the decrease in milk production due to high summer temperatures. This significance is given both for the volume of milk and for the amount of fat in it

On Implementing Autonomic Systems with a Serverless Computing Approach: The Case of Self-Partitioning Cloud Caches

The research community has made significant advances towards realizing self-tuning cloud caches; notwithstanding, existing products still require manual expert tuning to maximize performance. Cloud (software) caches are built to swiftly serve requests; thus, avoiding costly functionality additions not directly related to the request-serving control path is critical. We show that serverless computing cloud services can be leveraged to solve the complex optimization problems that arise during self-tuning loops and can be used to optimize cloud caches for free. To illustrate that our approach is feasible and useful, we implement SPREDS (Self-Partitioning REDiS), a modified version of Redis that optimizes memory management in the multi-instance Redis scenario. A cost analysis shows that the serverless computing approach can lead to significant cost savings: The cost of running the controller as a serverless microservice is 0.85% of the cost of the always-on alternative. Through this case study, we make a strong case for implementing the controller of autonomic systems using a serverless computing approach

Valor leche de la urea en la cabra de raza granadina (I)

Del tratamiento estadístico de nuestros resultados se deduce: que la urea disminuye la producción de leche y grasa de la misma. Esta disminución es proporcional a la dosis de urea utilizada en el caso del volumen de la leche, mientras que en la producción de grasa, el mayor descenso se obtiene con la ración que contiene el 30 % de urea. El costo de los alimentos necesarios para producir un litro de leche, disminuye el sustituir la veza por la urea, siendo esta disminución más marcada en los animales que consumieron raciones con 30 % de urea.The statistical treatment of our results it follows: the urea decreased milk production and fat of it. This decrease is proportional to the doses used in urea If the volume of milk, whereas in the production of fat, greatest decrease is obtained with ration containing 30% of urea. The cost of food needed to produce a liter of milk, vetches decreases replace the urea, this being more marked decrease in animals consuming diets with 30% urea.Cátedra de Fisiología Animal (Prof. Dr. G. Varela