Performance enhancement of WLAN IEEE 802.11 for asymmetric traffic

Most studies about the performance of IEEE 802.11 consider scenarios of ad-hoc topology and networks where all stations have the same traffic load (symmetric traffic conditions). This paper presents a study of performance parameters of more realistic networks. We focus the attention on WLAN with infrastructure networks, where the traffic distribution is asymmetric. In this case, the traffic load at the access point is much heavier than that at user stations. These studies are more realistic because most nowadays installed WLAN are infrastructure topology type, due to the fact that they are used as access networks. In this case, the access point has to retransmit all incoming traffic to the basic service set and therefore its traffic load is higher. Finally, the paper presents the tuning of the contention window, taken from IEEE 802.11e, used to increase the system performance under asymmetric traffic conditions, and the proposal of an adaptive algorithm to adapt the MAC layer settings to the system traffic load.Peer Reviewe

Performance enhancement of outdoor IEEE 802.11 cellular networks

Most studies about the performance of IEEE 802.11 are limited to a single cell environment. Nevertheless, the idea of designing an outdoor cellular network based on WLAN IEEE 802.11 results very attractive, due to the several advantages that this technology presents: the low cost of the equipment, its operation in unlicensed spectrum and its higher data rates. If we compare the system performance in a cellular environment with its behavior in a single cell environment, we observe that its performance decreases considerably with the growth of the transmission data rate employed and due to co-channel interference. In this paper, we propose some enhancement mechanisms, in order to reduce the interference influence on network performance. Moreover, we study the viability of using sectorised antennas at the access points. We present its performance under different load conditions and compare this behavior with the results obtained in an isolated single cell environment, which has no interference.Peer Reviewe

Análisis del protocolo IEEE 802.11b en un entorno celular

In this paper we present an analysis of the protocol IEEE 802.11b in different environments. Its performance in an indoor environment is evaluated, in terms of throughput and transmission delay, and the influence of the beacon period is analyzed. On the other hand, a possible technique to improve the throughput and transmission delay is exposed, and the importance of the contention windows value is studied to improve performance in presence of asymmetric data traffic. Finally the protocols characteristics in outdoors environments are explained and its performance is studied, in terms of throughput and transmission delay.Peer Reviewe

Las Prácticas Preprofesionales: espacio para ratificar la apropiación de saberes integrados (Original).

The preprofesional practices constitute the moment where students reach the formation of habits, abilities, moral values, social and labor rules of conduct and are trained in the solution of the various professional problems of his specialty. For this purpose, the need to seek and apply ways and new forms where the limits between the subjects and their contends are   eliminated from the complexity in which we are submerged is evident. The elaboration of a methodology is proposed, to contribute to the appropriation of integrated knowledge in the Veterinary Zootechny specialty, it´s a descriptive investigation that is carried out in the specialty of the same name at the Carmelo Noa Gil Mixed Center of the Bayamo municipality, Granma province. We work with a population made up four professors who attend Preprofessional Practices and 30 students.The appropriation of integrated knowledges is achieved to the extent that students solve  professional teaching problems of a higher level of complexity in the polytechnic school and in the jobs of the labor entity .  Las Prácticas Preprofesionales constituyen el momento en que los estudiantes alcanzan la formación de hábitos, habilidades, valores, normas de conducta social y laboral y se adiestran en la solución de los diversos problemas profesionales de su especialidad. Para este propósito se  evidencia la necesidad de buscar y aplicar vías y nuevas formas en las que se eliminen los límites entre las asignaturas y  sus contenidos a partir de la complejidad en que están sumergidos. Se propone la elaboración de una metodología para contribuir a la apropiación de saberes integrados en la especialidad Zootecnia Veterinaria; la investigación es de tipo descriptiva y se lleva a cabo en la especialidad de igual nombre en el Centro Mixto “Carmelo Noa Gil” del municipio Bayamo, provincia Granma. Se trabaja con una población constituida por 12 profesores que imparten asignaturas de base zootécnica y 126 estudiantes, y la muestra está conformada por cuatro profesores que atienden las Prácticas Preprofesionales y 30 estudiantes. La apropiación de saberes integrados se logra en  la medida en que los estudiantes resuelven problemas docentes profesionales de mayor nivel de complejidad en la escuela politécnica y en los puestos de trabajo de la entidad laboral.&nbsp

The effectiveness of cognitive-behavioral therapy for emotional distress in breast cancer

En los últimos años, el cáncer de mama se ha constituido como una enfermedad crónica con alta prevalencia y costes económicos asociados elevados. El presente estudio examina la efectividad de un tratamiento protocolizado cognitivoconductual sobre las principales variables psicosociales (calidad de vida, estrategias afrontamiento, ansiedad, depresión e ira) en el contexto clínico real. Siete mujeres diagnosticadas de cáncer de mama siguieron un tratamiento psicológico completo. Los resultados mostraron incrementos estadísticamente significativos en su calidad de vida, especialmente en las dimensiones de rol y emocional. Por otro lado, se observó una reducción significativa en la estrategia de afrontamiento de refrenar emoción, así como una reducción significativa de sintomatología ansiosa, depresiva, niveles de ira rasgo junto con un aumento significativo de control ira interna. Dichos resultados se acompañaron de tamaños del efecto grandes

Comparing assembly strategies for third-generation sequencing technologies across different genomes

The recent advent of long-read sequencing technologies, such as Pacific Biosciences (PacBio) and Oxford Nanopore technology (ONT), has led to substantial accuracy and computational cost improvements. However, de novo whole-genome assembly still presents significant challenges related to the computational cost and the quality of the results. Accordingly, sequencing accuracy and throughput continue to improve, and many tools are constantly emerging. Therefore, selecting the correct sequencing platform, the proper sequencing depth and the assembly tools are necessary to perform high-quality assembly. This paper evaluates the primary assembly reconstruction from recent hybrid and non-hybrid pipelines on different genomes. We find that using PacBio high-fidelity long-read (HiFi) plays an essential role in haplotype construction with respect to ONT reads. However, we observe a substantial improvement in the correctness of the assembly from high-fidelity ONT datasets and combining it with HiFi or short-reads.Funding for open access charge: Universidad de Málaga / CBU

Whole-Genome Assembly: An Experimental Study of Computational Costs and Architectural Opportunities

Whole-genome sequencing (WGS) pro- vides a huge amount of reads from which a comple- te genome could be assembled. The recent advent of long read sequencing technologies, such as PacBio and Oxford Nanopore, and the subsequent appearance of high quality long reads (single molecule high-fidelity, or HiFi) have improved the scaffolding of the genome. However, both biology and computing communities still face great challenges in terms of computational cost. Thus, it is essential a high precision characte- rization of the methods for a correct identification of the main computing bottlenecks. This study will allow us to design new methods to mitigate compu- tational costs without losing accuracy and to adapt such methods to fully exploit new architectures that provide support to handle big amounts of data. In this paper, we experimentally study and characterize the most used whole-genome assemblers in order to design new approaches in this field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Condiciones biológicas, sociales y familiares asociadas al afrontamiento familiar ante el nacimiento de pretérminos en la ciudad de Cartagena – Colombia

CONTEXTO: El nacimiento de un hijo es un acontecimiento de vital trascendencia que genera cambios y ocasiona crisis, modificando la rutina cotidiana tanto de los padres como de la familia, dicho evento requiere de un despliegue de estrategias que ayuden a afrontar el estrés generado por la situación vivida. A esas estrategias se les conocen como afrontamiento, que no es más que una respuesta al cambio así como la producción de nuevas conductas que le permitan a la familia hacer frente a las diversas problemáticas vividas. El nacimiento de niño pretérmino es uno de los principales generadores de crisis, estrés y tensiones familiares debido a que el recién nacido por no cumplir con las semanas completas en el vientre materno, presenta inmadurez en sus órganos y sistemas y por ello necesita cuidados especiales. Hay diferentes características que presentan las familias, (edad, baja escolaridad, pobre apoyo social, disfunción familiar, bajos ingreso etc.) las cuales determinan la forma en que cada familia afronta la situación de prematurez de su nuevo miembro. OBJETIVO: Determinar la asociación entre las condiciones biológicas, familiares, sociales y el afrontamiento familiar de padres ante el nacimiento de un niño pretérmino. METODOLOGÍA: estudio transversal realizado durante el 2009; la población estuvo constituida por 1 980 padres de los recién nacidos pretérminos de las Unidades de cuidados intensivos de la ciudad de Cartagena, y la muestra la integraron 277 padres. Confianza del 95%, un error del 5% y una prevalencia de afrontamiento del 50%. Los padres fueron seleccionados por muestreo por conglomerados. Los instrumentos utilizados fueron el APGAR FAMILIAR, FICHA SOCIODEMOGRÁFICA, y F-COPES. Para estimar la asociación entre las variables se utilizó el programa SPSS 16.0. RESULTADOS: el 85.9% de los padres de los niños pretérminos tienen un afrontamiento eficaz; entre las variables que se asocian significativamente con el afrontamiento familiar ante el nacimiento de un niño pretérmino se encontraron: el estado civil OR: 0.342 (0,120 - 0,976) y los ingresos económicos OR: 3,905 (1,682- 9,068). CONCLUSIÓN: el afrontamiento familiar ante el nacimiento de un niño pretérmino se asoció con condiciones sociales tales como: el estado civil y los ingresos económicos. Las condiciones biológicas y familiares no mostraron asociación. (DUAZARY 2011 No. 2, 150 - 158

3,4-Methylenedioxy methamphetamine, synthetic cathinones and psychedelics: From recreational to novel psychotherapeutic drugs

The utility of classical drugs used to treat psychiatric disorders (e.g.,antidepressants, anxiolytics) is often limited by issues of lack of efficacy, delayed onset of action or side effects. Psychoactive substances have a long history of being used as tools to alter consciousness and as a gateway to approach the unknown and the divinities. These substances were initially obtained from plants and animals and more recently by chemical synthesis, and its consumption evolved toward a more recreational use, leading to drug abuse-related disorders, trafficking, and subsequent banning by the authorities. However, these substances, by modulation of certain neurochemical pathways, have been proven to have a beneficial effect on some psychiatric disorders. This evidence obtained under medically controlled conditions and often associated with psychotherapy, makes these substances an alternative to conventional medicines, to which in many cases the patient does not respond properly. Such disorders include post-traumatic stress disease and treatment-resistant depression, for which classical drugs such as MDMA, ketamine, psilocybin and LSD, among others, have already been clinically tested, reporting successful outcomes. The irruption of new psychoactive substances (NPS), especially during the last decade and despite their recreational and illicit uses, has enlarged the library of substances with potential utility on these disorders. In fact, many of them were synthetized with therapeutic purposes and were withdrawn for concrete reasons (e.g., adverse effects, improper pharmacological profile). In this review we focus on the basis, existing evidence and possible use of synthetic cathinones and psychedelics (specially tryptamines) for the treatment of mental illnesses and the properties that should be found in NPS to obtain new therapeutic compounds

Synergistic effect of antimetabolic and chemotherapy drugs in triple-negative breast cancer

The triple-negative breast cancer (TNBC) subtype comprises approximately 15% of all breast cancers and is associated with poor long-term outcomes. Classical chemotherapy remains the standard of treatment, with toxicity and resistance being major limitations. TNBC is a high metabolic group, and antimetabolic drugs are effective in inhibiting TNBC cell growth. We analyzed the combined effect of chemotherapy and antimetabolic drug combinations in MDA-MB-231, MDA-MB-468 and HCC1143 human TNBC cell lines. Cells were treated with each drug or with drug combinations at a range of concentrations to establish the half-maximal inhibitory concentrations (IC50). The dose-effects of each drug or drug combination were calculated, and the synergistic or antagonistic effects of drug combinations were defined. Chemotherapy and antimetabolic drugs exhibited growth inhibitory effects on TNBC cell lines. Antimetabolic drugs targeting the glycolysis pathway had a synergistic effect with chemotherapy drugs, and antiglycolysis drug combinations also had a synergistic effect. The use of these drug combinations could lead to new therapeutic strategies that reduce chemotherapy drug doses, decreasing their toxic effect, or that maintain the doses but enhance their efficacy by their synergistic effect with other drugsMaría I. Lumbreras-Herrera and Andrea Zapater-Moros are supported by Consejería de Educación e Investigación de la Comunidad de Madrid (IND2018/BMD-9262). Elena López-Camacho is supported by the Spanish Economy and Competitiveness Ministry (PTQ2018–009760). This work is supported by an unrestricted grant from Roch