Online Coalition Formation under Random Arrival or Coalition Dissolution

Coalition formation considers the question of how to partition a set of $n$ agents into disjoint coalitions according to their preferences. We consider a cardinal utility model with additively separable aggregation of preferences and study the online variant of coalition formation, where the agents arrive in sequence and whenever an agent arrives, they have to be assigned to a coalition immediately. The goal is to maximize social welfare. In a purely deterministic model, the greedy algorithm, where an agent is assigned to the coalition with the largest gain, is known to achieve an optimal competitive ratio, which heavily relies on the range of utilities. We complement this result by considering two related models. First, we study a model where agents arrive in a random order. We find that the competitive ratio of the greedy algorithm is $\Theta\left(\frac{1}{n^2}\right)$, whereas an alternative algorithm, which is based on alternating between waiting and greedy phases, can achieve a competitive ratio of $\Theta\left(\frac{1}{n}\right)$. Second, we relax the irrevocability of decisions by allowing to dissolve coalitions into singleton coalitions, presenting a matching-based algorithm that once again achieves a competitive ratio of $\Theta\left(\frac{1}{n}\right)$. Hence, compared to the base model, we present two ways to achieve a competitive ratio that precisely gets rid of utility dependencies. Our results also give novel insights in weighted online matching.Comment: Appears in the 31st Annual European Symposium on Algorithms (ESA 2023

Herbal Remedies for Breast Cancer Prevention and Treatment

Breast cancer is among the most common type of cancer in women around the globe. Prevention of breast cancer is better than its treatment. Because of the molecular variation and complexity underlying breast cancer occurrence, its treatment by using chemotherapy and/or radiotherapy is very complicated and often leads to undesirable side effects. Plants and their extracts have been used for centuries for the treatment of almost every disease and breast cancer is not an exception. Herbal products can be trusted for cancer treatment because of their low toxicity. Besides, herbal remedies are easily accepted by the majority of woman suffering from breast cancer because of their easy availability and affordability. In the last decade, a large number of plants and their compounds were reported to show promising anticancerous effects against breast cancer cells in both in vivo and in vitro models. However, their beneficial effects on breast cancer treatment are still doubtful due to the lack of randomized clinical trials. This chapter is dedicated to reporting the potential of some herbal products for the prevention and/or treatment of breast cancer. Besides, it focused on the anticarcinogenic mechanism of those phytocompounds to report their potential chemotherapeutic role

Procedimiento de preparación de derivados de tipo arilo-heteroarilo y arilo-arilo y compuestos obtenidos

El objeto de la presente invención es un procedimiento de preparación de derivados de tipo arilo — heteroarilo y arilo - arilo a partir de anilinas o sales de diazonio y de compuestos aromáticos, que pueden ser arilos o heteroarilo, en el cual se utilizan materiales que aportan ácido ascórbico o sus derivados como catalizadores. Constituyen igualmente un objeto de la presente invención los compuestos obtenidos mediante el referido procedimiento.Peer reviewedConsejo Superior de Investigaciones CientíficasA1 Solicitud de adición a la patent

La protección del derecho del propietario de la vivienda frente a la okupación

The Spanish Constitution recognizes the right of home, but this right does not entail a legal obligation for the owners to bear the dispossession of their property to guarantee the right against those who do not have any, and much less, in an illegitimate way as it is happening, frequently, in this country with the so-called squatting phenomenon. Each year exceeds the previous one, with respect to the number of properties that have been squatted, that is, the owner's possession was taken from the squatter, illegally. Faced with this, the owner can defend himself both through civil and criminal proceedings, either through actual actions, filing a lawsuit, or through a complaint, if the way in which the squatting was carried out constitutes a crime. However, and despite some legislative improvements to protect the rights of the owners, squatting continues increasing, and even more so, after the last legislative change and as a consequence of the pandemic. All of this, and in the face of instability that generates social discontent, has created the ideal conditions for the emergence of private undocking companies that try to provide a solution that, legislatively, does not always arrive.La Constitución Española reconoce el derecho a una vivienda, pero este derecho no conlleva una obligación legal para los propietarios de soportar el despojo de su inmueble para garantizar el derecho frente a quien no ostenta ninguno, y mucho menos, de una manera ilegítima como está sucediendo, de forma frecuente, en este país con el denominado fenómeno okupa. Cada año supera al anterior, respecto al número de inmuebles que han sido okupados, es decir, arrebatada la posesión del propietario por parte del okupa, ilegalmente. Ante ello, el propietario puede defenderse tanto por la vía civil, como por la vía penal, ya sea mediante acciones reales, interponiendo demanda, o mediante querella, si el modo en que la okupación fue llevada a cabo, constituye delito. No obstante, y a pesar de algunas mejoras legislativas para proteger los derechos de los propietarios, la okupación sigue aumentando, y más aún, tras la última modificación legislativa y como consecuencia de la pandemia. Todo ello, y ante una inestabilidad que genera descontento social, ha propiciado las condiciones idóneas para la aparición de empresas privadas de desokupación que intentan dar una solución que, legislativamente, no siempre llega