Integrated approach to assignment, scheduling and routing problems

This research considers a real life case study that determines the minimum number of sellers required to attend a set of customers located in a certain region taking into account the weekly schedule plan of the visits, as well as the optimal route. The problem is formulated as a combination of assignment, scheduling and routing problems. In the new formulation, case studies of small size subset of customers of the above type can be solved optimally. However, this subset of customers is not representative within the business plan of the company. To overcome this limitation, the problem is divided into three phases. A greedy algorithm is used in Phase I in order to identify a set of cost-effective feasible clusters of customers assigned to a seller. Phase II and III are then used to solve the problem of a weekly program for visiting the customers as well as to determine the route plan using MILP formulation. Several real life instances of different sizes have been solved demonstrating the efficiency of the proposed approach

Integrated Approach to Assignment, Scheduling and Routing Problems in a Sales Territory Business Plan

AbstractThis paper considers a real life case study that determines the minimum number of sellers required to attend a set of customers located in a certain region taking into account the weekly schedule plan of the visits, as well as the optimal route. The problem is formulated as a combination of assignment, scheduling and routing problems. In the new formulation, case studies of small size subset of customers of the above type can be solved optimally. However, this subset of customers is not representative within the business plan of the company. To overcome this limitation, the problem is divided into three phases. A greedy algorithm is used in Phase I in order to identify a set of cost-effective feasible clusters of customers assigned to a seller. Phase II and III are then used to solve the problem of a weekly program for visiting the customers as well as to determine the route plan using MILP formulation. Several real life instances of different sizes have been solved demonstrating the efficiency of the proposed approach

Emerging planetary nebulae within 3D spiral patterns

We present the first 3D radiation-hydrodynamic simulations of the formation of planetary nebulae (PNe) emerging from 3D spiral patterns. We use the GUACHO code to create 3D spiral structures as a consequence of the distortions on the geometry of the intrinsically isotropic wind of an asymptotic giant branch (AGB) star produced by a companion star in a circular orbit. We found that the orbital period of the binary producing the 3D spiral pattern has consequences on the formation and shaping of the PN itself. Stellar systems with longer period create less entwined 3D spirals, producing PNe with rounder inner cavities, and prevent the expansion of jet towards the polar directions. The spiral fitting procedure used in the literature to predict the binary's orbital period may be misleading in the case of proto-PNe and PNe as spiral patterns are diluted by their own thermal expansion down to the average AGB density profile within a few hundred years and are further disrupted by the action of jets. By adopting a phase of jet ejections between the AGB and post-AGB stages, we are able to recover the morphologies of proto-PNe and PNe that exhibit ring-like structures in their halos.Comment: 12 pages, 12 figures, 1 table; Accepted to MNRA

Biomarkers of aging associated with past treatments in breast cancer survivors.

Radiation and chemotherapy are effective treatments for cancer, but are also toxic to healthy cells. Little is known about whether prior exposure to these treatments is related to markers of cellular aging years later in breast cancer survivors. We examined whether past exposure to chemotherapy and/or radiation treatment was associated with DNA damage, telomerase activity, and telomere length 3-6 years after completion of primary treatments in breast cancer survivors (stage 0-IIIA breast cancer at diagnosis). We also examined the relationship of these cellular aging markers with plasma levels of Interleukin (IL)-6, soluble TNF-receptor-II (sTNF-RII), and C-reactive protein (CRP). Ninety-four women (36.4-69.5 years; 80% white) were evaluated. Analyses adjusting for age, race, BMI, and years from last treatment found that women who had prior exposure to chemotherapy and/or radiation compared to women who had previously received surgery alone were more likely to have higher levels of DNA damage (P = .02) and lower telomerase activity (P = .02), but did not have differences in telomere length. More DNA damage and lower telomerase were each associated with higher levels of sTNF-RII (P's < .05). We found that exposure to chemotherapy and/or radiation 3-6 years prior was associated with markers of cellular aging, including higher DNA damage and lower telomerase activity, in post-treatment breast cancer survivors. Furthermore, these measures were associated with elevated inflammatory activation, as indexed by sTNF-RII. Given that these differences were observed many years after the treatment, the findings suggest a long lasting effect of chemotherapy and/or radiation exposure

Dental conditions in rheumatic diseases.

Objectives. Review oral manifestations of rheumatic diseases since these can be a diagnostic challenge.Procedures. We performed a PubMed search using terms of rheumatic diseases, autoimmune disease and oral manifestations and also reviewed related guidelines and classifications.Results. We describe the clinical presentations of rheumatic diseases, such as scleroderma, rheumatoid arthritis, Sjögren's syndrome, Systemic lupus erythematosus and others that present specific oral manifestations. We also review the association between periodontal disease and autoimmunity that has been recently described in the literature.Conclusions. The oral manifestations of rheumatic diseases are diverse and can represent a challenge for medical and dental professionals

Improved Performance of an Epoxy Matrix as a Result of Combining Graphene Oxide and Reduced Graphene

We present an easy and effective way to improve the mechanical properties of an epoxy matrix by reinforcing it with a combination of graphene oxide (GO) and reduced graphene oxide (RGO). These nanocomposites were prepared with different load of nanofillers: 0.1, 0.4, 0.7, 1.0 wt% and a neat epoxy. Ratios of graphene oxide and reduced graphene (GO : RGO) employed were: 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0. Results show that with only 0.4 wt% and a ratio 0.2 : 0.75 of GO : RGO, tensile strength and tensile toughness are 52% and 152% higher than neat epoxy while modulus of elasticity was improved ~20%. The obtained results suggest that it is possible achieve advantageous properties by combining graphene in oxidized and reduced conditions as it shows a synergic effect by the presence of both nanofillers

Association of immune responses of Zebu and Holstein-Friesian cattle and resistance to mycobacteria in a BCG challenge model

Mycobacterium bovis is the main cause of bovine tuberculosis (BTB) in cattle and can also infect humans. Zebu cattle are considered more resistant to some infectious diseases compared with Holstein‐Friesian (HF) cattle, including BTB. However, epidemiological studies may not take into account usage differences of the two types of cattle. HF cattle may suffer greater metabolic stress due to their more or less exclusive dairy use, whereas Zebu cattle are mainly used for beef production. In experiments conducted so far, the number of animals has been too small to draw statistically robust conclusions on the resistance differences between these cattle breeds. Here, we used a BCG challenge model to compare the ability of naïve and vaccinated Zebu and HF cattle to control/kill mycobacteria. Young cattle of both breeds with similar ages were housed in the same accommodation for the duration of the experiment. After correcting for multiple comparisons, we found no difference between naïve HF and Zebu (ρ = 0.862) cattle. However, there was a trend for vaccinated HF cattle to have lower cfu numbers than non‐vaccinated HF cattle (ρ = 0.057); no such trend was observed between vaccinated and non‐vaccinated Zebu cattle (ρ = 0.560). Evaluation of antigen‐specific IFNγ secretion by PBMC indicated that Zebu and HF cattle differed in their response to mycobacteria. Thus, whilst there may be difference in immune responses, our data indicate that with the number of animals included in the study and under the conditions used in this work, we were unable to measure any differences between Zebu and HF cattle in the overall control of mycobacteria. Whilst determination of different susceptibilities between Zebu and HF cattle using the BCG challenge model will require larger numbers of animals than the number of animals used in this experiment, these data should inform future experiments

The Neutrophil-Lymphocyte Ratio is an Independent Prognostic Factor for Overall Survival in Hispanic Patients with Gastric Adenocarcinoma

Introduction High values of neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are related with poor prognosis in patients with gastric cancer. However, this association has been rarely assessed in Hispanic populations that show important clinicopathological differences to Asian and Caucasian patients. In this study, we determined the prognostic value of these biomarkers in Hispanic patients from Costa Rica. Materials and Methods We retrieved data regarding pre-treatment NLR and PLR, as well as clinical variables from medical records of 381 consecutive gastric cancer patients treated in four major hospitals in Costa Rica between 2009 and 2012. Univariate and multiple Cox regression analyses were performed to assess the value of NLR and PLR as predictors of overall survival (OS) and disease-free survival (DFS). The best cutoff point was based on the maximization of the Log-rank test. Results Median follow-up was 13.21 months. In univariate analysis, a NLR ≥ 5 was associated with reduced DFS (hazard ratio (HR) 2.31; 95% confidence interval (CI) 1.78–3.00; p < 0.001) and poor OS (HR 2.24; 95% CI 1.72–2.92; p < 0.001). Similarly, a PLR ≥ 350 was associated with worse DFS (HR 2.28; 95% CI 1.70–3.06; p < 0.001) and poor OS (HR 2.33; 95% CI 1.73–3.13; p < 0.001). After adjustment for potential confounders, multivariate analysis revealed that only the NLR ≥ 5 was independently associated with worse DFS (HR 1.97; 95% CI 1.44–2.47) and OS (HR 1.59; 95%CI 1.15–2.28). Conclusions NLR ≥ 5 was independently associated with worse OS and DFS in Hispanic patients with gastric cancer.Universidad de Costa Rica/[817-B2-371]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones Farmacéuticas (INIFAR)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC

Transancestral mapping and genetic load in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions (P<5 × 10-8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE

Evolución del volcanismo submarino en el estrecho Bransfield: Relación de las emanaciones hidrotermales con la biodiversidad y el cambio climático - [Boletín M 1]

Las expediciones científicas peruanas a la Antártida se realizan desde el año 1988, fecha en la que se realizó la Primera Expedición Científica Peruana a la Antártida – ANTAR I. Esta expedición se realizó a bordo del BIC Humboldt. El Ingemmet, como ente rector de las geociencias en nuestro país, participa desde la segunda expedición antártica, primero como apoyo técnico y geológico en Punta Crepín, isla Rey Jorge, para la construcción y ampliación de la Estación Científica Machu Picchu. A partir del período 2018-2019 y con arribo de la moderna plataforma BAP Carrasco, se empiezan a desarrollar proyectos de investigación multidisciplinarios en geología marina y antártica, con colaboración de instituciones nacionales e internacionales. Siendo así, el Ingemmet, para el desarrollo de la XXVII Expedición Científica Peruana a la Antártida – ANTAR XXVII, presenta un proyecto multidisciplinario que busca relacionar el impacto de la geología en la distribución y biodiversidad del fondo marino Este proyecto se titula “Evolución del Volcanismo Submarino en el estrecho de Bransfield: Relación de las Emanaciones Hidrotermales con la Biodiversidad y el Cambio Climático” y se desarrolla en coordinación y cooperación entre el Instituto Geológico Minero y Metalúrgico (Ingemmet), la universidad Científica del Sur (Científica – Perú), la Facultad de Ciencias, Universidad de la República (Uruguay) y el Instituto de Investigaciones Marinas y Costeras José Benito Vives de Andréis (Invemar - Colombia). Este proyecto busca caracterizar la morfología y composición de los volcanes y emanaciones hidrotermales submarinas, así como identificar las comunidades biológicas, microbiológicas y características medioambientales del estrecho de Bransfield, Antártida. Siendo así, las actividades para cumplir este objetivo se desarrollan a través de la realización de cruceros de investigación geológica-oceanográfica, que se denominan cruceros multinacionales ORCA. La ejecución de las actividades se realiza a bordo de la plataforma científica BAP Carrasco, y son coordinadas por la Dirección de Asuntos Antárticos del Ministerio de Relaciones Exteriores. El crucero tuvo una duración de 15 días efectivos de trabajo y abarco 4 áreas de recolección de información: bahía Collins, bahía Almirantazgo, bahía Esperanza y estrecho de Bransfield. Así también, comprendió el levantamiento de información geológica, oceanográfica, biológica, microbiológica, radiológica y de microplásticos entre la isla Rey Jorge y la península antártica. El presente boletín tiene por objetivo mostrar toda la información recopilada durante el desarrollo del Crucero ORCA I, para que sea de disponibilidad de la comunidad científica