Collaborative Delivery with Energy-Constrained Mobile Robots

We consider the problem of collectively delivering some message from a specified source to a designated target location in a graph, using multiple mobile agents. Each agent has a limited energy which constrains the distance it can move. Hence multiple agents need to collaborate to move the message, each agent handing over the message to the next agent to carry it forward. Given the positions of the agents in the graph and their respective budgets, the problem of finding a feasible movement schedule for the agents can be challenging. We consider two variants of the problem: in non-returning delivery, the agents can stop anywhere; whereas in returning delivery, each agent needs to return to its starting location, a variant which has not been studied before. We first provide a polynomial-time algorithm for returning delivery on trees, which is in contrast to the known (weak) NP-hardness of the non-returning version. In addition, we give resource-augmented algorithms for returning delivery in general graphs. Finally, we give tight lower bounds on the required resource augmentation for both variants of the problem. In this sense, our results close the gap left by previous research.Comment: 19 pages. An extended abstract of this paper was published at the 23rd International Colloquium on Structural Information and Communication Complexity 2016, SIROCCO'1

Autoimmune neurological conditions associated with Zika virus infection

Zika virus (ZIKV) is an emerging flavivirus rapidly spreading throughout the tropical Americas. mosquitoes is the principal way of transmission of the virus to humans. ZIKV can be spread by transplacental, perinatal, and body fluids. ZIKV infection is often asymptomatic and those with symptoms present minor illness after 3 to 12 days of incubation, characterized by a mild and self-limiting disease with low-grade fever, conjunctivitis, widespread pruritic maculopapular rash, arthralgia and myalgia. ZIKV has been linked to a number of central and peripheral nervous system injuries such as Guillain-Barré syndrome (GBS), transverse myelitis (TM), meningoencephalitis, ophthalmological manifestations, and other neurological complications. Nevertheless, mechanisms of host-pathogen neuro-immune interactions remain incompletely elucidated. This review provides a critical discussion about the possible mechanisms underlying the development of autoimmune neurological conditions associated with Zika virus infection

Estudio comparativo de las herramientas MetaCASE bajo consistencia y refinamiento*

Las herramientas MetaCASE surgieron como una evolución de la tecnología CASE, para superar algunas de las limitaciones identificables en este tipo de tecnologías. Estas herramientas poseen mecanismos que permiten la creación y modificación de paradigmas de metamodelamiento, además de la adición de restricciones que se pueden emplear en chequeos de consistencia o transformaciones de refinamiento. En el artículo que aquí se presenta, se realiza un estudio comparativo de cinco herramientas MetaCASE (AToM3, DOME, GME, MetaEdit+ y UN-MetaCASE), tomando en cuenta dos puntos de vista: características generales y capacidades para la realización de chequeos de consistencia y transformaciones de refinamiento. El artículo concluye con un análisis comparativo de dichas herramientas

Development of Ceramic Water Filter Clay Selection Criteria

Ceramic water filters (CWFs) are point-of-use drinking water treatment systems that are manufactured and used in under-served communities around the world. The clayey material (CM) used to manufacture CWFs is a locally sourced mixture of clay, sand, slit and amorphous material (usually dug near the CWF factory). CM varies in composition and purity depending on the geographical location and geological setting. In this study, a set of 13 CM samples collected from around the world were analyzed using grain size analysis, as well as liquid and plastic limit tests. Mineralogical composition was determined using X-ray diffraction. A selection of three CM samples (Guatemala, Canada, and Guinea Bissau) with a range of compositions were used to study biofilm growth on CM before and after firing. Biofilm coverage was studied on CM (before firing) and CWF material (after firing) using Pseudomonas fluorescens Migula. The average biofilm coverages for Guatemala, Canada, and Guinea Bissau CM were 20.03 ± 2.80%, 19.28 ± 0.91%, and 9.88 ± 4.02%, respectively. The average biofilm formation coverages for Guatemala, Canada, and Guinea Bissau CWF were 13.08 ± 1.74%, 10.36 ± 3.41%, and 8.66 ± 0.13%, respectively. The results presented here suggest that CM can be manipulated to manufacture better performing CWFs by engineering the soil characteristics, such as grain size, liquid and plastic limits, and mineralogy. This could improve the durability and biofilm resistance of CWFs

Localization and Capacitance Fluctuations in Disordered Au Nano-junctions

Nano-junctions, containing atomic-scale gold contacts between strongly disordered leads, exhibit different transport properties at room temperature and at low temperature. At room temperature, the nano-junctions exhibit conductance quantization effects. At low temperatures, the contacts exhibit Coulomb-Blockade. We show that the differences between the room-temperature and low temperature properties arise from the localization of electronic states in the leads. The charging energy and capacitance of the nano-junctions exhibit strong fluctuations with applied magnetic field at low temperature, as predicted theoretically.Comment: 20 pages 8 figure

First case of sterility associated with sex chromosomal abnormalities in a jenny

Chromosomal abnormalities are one of the main causes of genetic infertility in horses. Currently, their detection rate is rising due to the use of new diagnostic tools employing molecular markers linked to the sex chromosome pair. Despite genetic similarities, there are no previous reports of sterility associated with chromosomal abnormalities in the domestic donkey (Equus asinus). Hereby, we determined the presence of a chromosomal mosaicism in a female donkey with reproductive problems using molecular methodologies developed for horses. A two-and- a- half- year- old jenny characterized by morphological abnormalities of the reproductive tract was cytogenetically analysed using conventional and fluorescent techniques and a group of microsatellite markers (short tandem repeat, STR). At the same time, five ultrasound measures of the reproductive tract were taken and compared with eight contemporary jennies of the same breed. After slaughter, morphological examinations showed that the case study had a blind vaginal vestibule defining an empty pouch that covered the entrance of the cervical os. Histopathological studies demonstrated that this abnormal structure was compatible with a remnant hymen. Molecular markers, STR and fluorescent in situ hybridization determinations revealed that the animal was a 62, XX/61,X mosaic and, therefore, the first case of chromosomal abnormalities in the sex pair reported in donkeys.Instituto de Genética Veterinari