Analysis of judgmental adjustments in the presence of promotions

Sales forecasting is increasingly complex due to many factors, such as product life cycles that have become shorter, more competitive markets and aggressive marketing. Often, forecasts are produced using a Forecasting Support System that integrates univariate statistical forecasts with judgment from experts in the organization. Managers add information to the forecast, like future promotions, potentially improving accuracy. Despite the importance of judgment and promotions, the literature devoted to study their relationship on forecasting performance is scarce. We analyze managerial adjustments accuracy under periods of promotions, based on weekly data from a manufacturing company. Intervention analysis is used to establish whether judgmental adjustments can be replaced by multivariate statistical models when responding to promotional information. We show that judgmental adjustments can enhance baseline forecasts during promotions, but not systematically. Transfer function models based on past promotions information achieved lower overall forecasting errors. Finally, a hybrid model illustrates the fact that human experts still added value to the transfer function models

El decaimiento y muerte de encinas en tres dehesas de la provincia de Huelva

Oak decline affecting three holm oak plots in Huelva has been studied along the last two years. Syndromes of dieback and sudden death have been observed. In both cases, unspecific aerial symptoms were associated with root rot. Characterisation of fungal isolates from necrotic roots led us to identify Phytophthora cinnamomi A2 consistently associated with the disease. Optimum growth temperatures of these isolates were very high (30.2°C). Inoculation tests under controlled conditions demonstrated the pathogenicity of the isolates in holm and cork oak seedlings. Symptomatology associated with other biotic factors of oak decline were never recorded, so in this case, forest decline model has not been the best choice to explain the disease observed. In fact, oak defoliation and mortality can be well explained as a disease of single aetiology caused by P. cinnamomi. Nevertheless, some abiotic factors as drought or the alternancy of drought and wet periods in the region seem to play an important role.Durante dos años se ha estudiado la evolución del decaimiento de encinas en tres dehesas de la comarca del Andévalo (Huelva). Se ha observado tanto el síndrome de muerte lenta como el de muerte súbita, con una sintomatologia aérea inespecífica asociada a la podredumbre del sistema radical. La caracterización de los aislados fúngicos obtenidos a partir de las raíces necrosadas ha permitido su identificación como Phytophthora cinnamomi A2, con temperaturas óptimas de crecimiento elevadas (30.2° C). La patogenicidad de estos aislados en encina y alcornoque se ha puesto de manifiesto en experimentos de inoculación de plantones en condiciones controladas. En ningún caso fue posible localizar síntomas ni signos de otros agentes bióticos implicados en la seca de los Quercus, por lo que, en el caso de las dehesas estudiadas, el modelo de decaimiento forestal no ha resultado la mejor explicación para la enfermedad observada. La explicación del problema se podría reducir a una enfermedad de etiología simple, cuyo agente causal es P. cinnamomi, y en la que algunos factores, como la sequía o la alternancia de períodos secos y lluviosos, pueden tener una influencia decisiva

Caracterización morfológica y cultural de aislados de "Colletotrichum" spp. causantes de la Antracnosis del olivo

La Antracnosis del olivo, causada por especies fúngicas del género Colletotrichum, es una enfermedad grave ampliamente distribuida en todas la regiones del mundo donde se cultiva el olivo. La incidencia de la enfermedad varia marcadamente en función de la susceptibilidad varietal, las condiciones climáticas y la virulencia del patógeno. Uno de los aspectos menos conocido de la enfermedad es la identificación del patógeno. Recientemente, se ha indicado que son dos las especies de Colletotrichum (C. acutatum y C. gloeosporioides) responsables de la Antracnosis del olivo, en lugar de una única especie (C. gloeosporioides = Gloeosporium olivarum) como se había considerado hasta ahora. En este trabajo se presentan los resultados de la caracterización morfológica y cultural de una colección de aislados de Colletotrichum obtenidos de olivos afectados de Antracnosis en varias comarcas olivareras de Andalucía. Aunque se han estudiado numerosos caracteres morfológicos y culturales, ninguno permitió una separación clara entre grupos de aislados o especies. No obstante, la forma de los extremos de las conidias fue el carácter más importante para su diferenciación. Casi todos los aislados de Colletotrichum de olivo (96%) tuvieron la mayoría de las conidias con un extremo redondeado y el otro agudo, diferenciándose de las conidias de C. gloeosporioides, con los dos extremos redondeados, y de las de C. acutatum, con los dos extremos agudos. Otras características estudiadas, como la coloración y el crecimiento de la colonia, la presencia de setas en los acérvulos, la presencia y morfología de las clamidosporas, la longitud y anchura de las conidias, o la formación de apresónos y conidias secundarias, mostraron una amplia variabilidad. Atendiendo a los resultados obtenidos, los aislados de Colletotrichum causantes de la Antracnosis del olivo en Andalucía se clasificarían dentro del complejo C. acutatum / C. gloeosporioides. Si bien, han mostrado características morfológicas y culturales más próximas a la especie C. acutatum. Su identificación definitiva requerirá de estudios adicionales para la caracterización fisiológica, molecular y patogénica de los aislados

Non-Linear Identification of Judgmental Forecasts Effects at SKU-Level

Prediction of demand is a key component within supply chain management. Im- proved accuracy in forecasts affects directly all levels of the supply chain, reduc- ing stock costs and increasing customer satisfaction. In many application areas, demand prediction relies on statistical software which provides an initial forecast subsequently modified by the expert’s judgment. This paper outlines a new method- ology based on State Dependent Parameter (SDP) estimation techniques to identify the non-linear behaviour of such managerial adjustments. This non-parametric SDP estimate is used as a guideline to propose a non-linear model that corrects the bias introduced by the managerial adjustments. One-step-ahead forecasts of SKU sales sampled monthly from a manufacturing company are utilized to test the proposed methodology. The results indicate that adjustments introduce a non-linear pattern undermining accuracy. This understanding can be used to enhance the design of the Forecasting Support System in order to help forecasters towards more efficient judgmental adjustments

Cost-effectiveness of Alzheimer's disease CSF biomarkers and amyloid-PET in early-onset cognitive impairment diagnosis

This study aimed at determining the cost-effectiveness of amyloid-positron emission tomography (PET) compared to Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers (amyloid-?42, total-Tau and phosphorylated-Tau) for the diagnosis of AD in patients with early-onset cognitive impairment. A decision tree model using a national health care perspective was developed to compare the costs and effectiveness associated with Amyloid-PET and AD CSF biomarkers. Available evidence from the literature and primary data from Hospital Clínic de Barcelona were used to inform the model and calculate the efficiency of these diagnostic alternatives. Medical visits and diagnostic procedures were considered and reported in €2020. We calculated the incremental cost-effectiveness ratio to measure the cost per % of correct diagnoses detected and we perform one-way deterministic and probabilistic sensitivity analyses to assess the uncertainty of these results. Compared with AD CSF biomarkers, Amyloid-PET resulted in 7.40% more correctly diagnosed cases of AD, with an incremental total mean cost of €146,854.80 per 100 cases. We found a 50% of probability that Amyloid-PET was cost-effective for a willingness to pay (WTP) of €19,840.39 per correct case detected. Using a WTP of €75,000, the probability that it is cost-effective reached a maximum of 76.9%, thus leading to a conclusion that Amyloid-PET is not a cost-effective technique compared to AD CSF biomarkers, unless the funder is willing to pay a minimum of €19,840.39 to detect one more correct case. Furthermore, obtaining CSF provides simultaneous information on amyloid ? and tau biomarkers and allows other biomarkers to be analyzed at a relatively low cost.© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany

Evidence Against the Sciama Model of Radiative Decay of Massive Neutrinos

We report on spectral observations of the night sky in the band around 900 angstroms where the emission line in the Sciama model of radiatively decaying massive neutrinos would be present. The data were obtained with a high resolution, high sensitivity spectrometer flown on the Spanish MINISAT satellite. The observed emission is far less intense than that expected in the Sciama model.Comment: 9 pages, accepted to Ap

Soil temperature determines the reaction of olive cultivars to verticillium dahliae pathotypes

Development of Verticillium wilt in olive, caused by the soil-borne fungus Verticillium dahliae, can be influenced by biotic and environmental factors. In this study we modeled i) the combined effects of biotic factors (i.e., pathotype virulence and cultivar susceptibility) and abiotic factors (i.e., soil temperature) on disease development and ii) the relationship between disease severity and several remote sensing parameters and plant stress indicators. Methodology: Plants of Arbequina and Picual olive cultivars inoculated with isolates of defoliating and non-defoliating V. dahliae pathotypes were grown in soil tanks with a range of soil temperatures from 16 to 32°C. Disease progression was correlated with plant stress parameters (i.e., leaf temperature, steady-state chlorophyll fluorescence, photochemical reflectance index, chlorophyll content, and ethylene production) and plant growth-related parameters (i.e., canopy length and dry weight). Findings: Disease development in plants infected with the defoliating pathotype was faster and more severe in Picual. Models estimated that infection with the defoliating pathotype was promoted by soil temperatures in a range of 16 to 24°C in cv. Picual and of 20 to 24°C in cv. Arbequina. In the non-defoliating pathotype, soil temperatures ranging from 16 to 20°C were estimated to be most favorable for infection. The relationship between stress-related parameters and disease severity determined by multinomial logistic regression and classification trees was able to detect the effects of V. dahliae infection and colonization on water flow that eventually cause water stress. Conclusions: Chlorophyll content, steady-state chlorophyll fluorescence, and leaf temperature were the best indicators for Verticillium wilt detection at early stages of disease development, while ethylene production and photochemical reflectance index were indicators for disease detection at advanced stages. These results provide a better understanding of the differential geographic distribution of V. dahliae pathotypes and to assess the potential effect of climate change on Verticillium wilt development.Financial support for this research was provided by Project P08-AGR-03528 from ‘‘Consejería de Economía, Innovación y Ciencia’’ of Junta de Andalucía and the European Social Fund (JANC), and projects AGL-2012-37521 (JANC) and AGL2012-40053-C03-01 (PJZT) from the Spanish ‘‘Ministerio de Economia y Competitividad’’ and the European Social Fund. R. Calderón is a recipient of research fellowship BES-2010-035511 from the Spanish ‘‘Ministerio de Ciencia e Innovación’’ and C. Lucena was a recipient of a JAE-DOC postdoctoral contract from ‘‘Consejo Superior de Investigaciones Científicas’’ (CSIC) co-funded by the European Social Fund. TPeer Reviewe

Water Stress Enhances the Progression of Branch Dieback and Almond Decline under Field Conditions

Branch dieback and tree decline have been described as a common complex disease worldwide in woody crops, with Botryosphaeriaceae and Diaporthaceae being considered the most frequent fungi associated with the disease symptoms. Their behaviour is still uncertain, since they are considered endophytes becoming pathogenic in weakened hosts when stress conditions, such as water deficiency occur. Therefore, the main goal of this study was to determine if water stress enhances general decline on weakened almond trees subjected to different irrigation treatments under natural field conditions. In parallel, the occurrence of fungal species associated with almond decline was also determined in relation to disease progression by fungal isolation, and morphological and molecular based-methods. The symptoms of branch dieback and general decline were observed over time, mainly in the experimental plots subjected to high water deficiency. Botryosphaeriaceae were the most consistently isolated fungi, and Botryosphaeria dothidea was the most frequent. Collophorina hispanica was the second most frequent species and Diaporthe and Cytospora species were isolated in a low frequency. Most of them were recovered from both asymptomatic and symptomatic trees, with their consistency of isolation increasing with the disease severity. This work reveals the need to elucidate the role of biotic and abiotic factors which increase the rate of infection of fungal trunk pathogens, in order to generate important knowledge on their life cycle

Genetic diversity and population structure of Ascochyta rabiei from the western Iranian Ilam and Kermanshah provinces using MAT and SSR markers

Knowledge of genetic diversity in A. rabiei provides different levels of information that are important in the management of crop germplasm resources. Gene flow on a regional level indicates a significant potential risk for the regional spread of novel alleles that might contribute to fungicide resistance or the breakdown of resistance genes. Simple sequence repeat (SSR) and mating type (MAT) markers were used to determine the genetic structure, and estimate genetic diversity and the prevalence of mating types in 103 Ascochyta rabiei isolates from seven counties in the Ilam and Kermanshah provinces of western Iran (Ilam, Aseman abad, Holaylan, Chardavol, Dareh shahr, Gilangharb, and Sarpul). A set of 3 microsatellite primer pairs revealed a total of 75 alleles; the number of alleles varied from 15 to 34 for each marker. A high level of genetic variability was observed among A. rabiei isolates in the region. Genetic diversity was high (He = 0.788) within populations with corresponding high average gene flow and low genetic distances between populations. The smallest genetic distance was observed between isolates from Ilam and Chardavol. Both mating types were present in all populations, with the majority of the isolates belonging to Mat1-1 (64%), but within populations the proportions of each mating type were not significantly different from 50%. Results from this study will be useful in breeding for Ascochyta blight-resistant cultivars and developing necessary control measures

Propagation of ionizing radiation in HII regions: the effects of optically thick density fluctuations

The accepted explanation of the observed dichotomy of two orders of magnitude between in situ measurements of electron density in HII regions, derived from emission line ratios, and average measurements based on integrated emission measure, is the inhomogeneity of the ionized medium. This is expressed as a "filling factor", the volume ratio of dense to tenuous gas, measured with values of order 10^-3. Implicit in the filling factor model as normally used, is the assumption that the clumps of dense gas are optically thin to ionizing radiation. Here we explore implications of assuming the contrary: that the clumps are optically thick. A first consequence is the presence within HII regions of a major fraction of neutral hydrogen. We estimate the mean H^o/H^+ ratio for a population of HII regions in the spiral galaxy NGC 1530 to be the order of 10, and support this inference using dynamical arguments. The optically thick clumpy models allow a significant fraction of the photons generated by the ionizing stars to escape from their HII region. We show, by comparing model predictions with observations, that these models give an account at least as good as, and probably better than that of conventional models, of the radial surface brightness distribution and of selected spectral line diagnostics for physical conditions within HII regions. These models explain how an HII region can appear, from its line ratios, to be ionization bounded, yet permit a major fraction of its ionizing photons to escape.Comment: 9 pages, 7 figures (2 of them in colours), accepted for publication in A&