¿Ineficiencias o diferencias tecnológicas en el sector lechero?

La estimación de funciones de producción suele basarse en el supuesto de que la tecnología es común para todos los productores. Sin embargo, en la muestra puede haber empresas que usen tecnologías diferentes. En este trabajo se emplea un modelo de clases latentes para estimar la tecnología de varios sistemas de producción de explotaciones lecheras según su grado de intensificación. Los resultados de esta estimación se comparan con los obtenidos usando otras dos aproximaciones. Una, el modelo clásico de frontera estocástica. La otra consiste en dividir la muestra mediante un análisis cluster y estimar una frontera de producción distinta para cada uno de los grupos. El análisis empírico se realiza con un panel completo compuesto por 169 explotaciones lecheras asturianas para el período comprendido entre 1999 y 200

Reflectance Measurements on Cultural Heritage

Cultural heritage is a valuable and characteristic symbol of every country. It should be handled with care and it must be exhaustively investigated and measured with non-destructive techniques. In this chapter, we will talk about different reflectance measurement techniques to obtain the conservation state of the artwork. With this reflectance characterization, conservators, and curators could soon determine the best maintenance procedures for restoration purposes. Also, a new technique for lighting will be discussed, where the artwork can be also photonically restored illuminating with the correct light in the desired area of the artwork using a spectrally selective projection system

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Economías y deseconomías de tamaño en la producción lechera

Incluye Bibliografí

Eficiencia tecnica en pesquerias multiespecie: una aproximacion primal

RESUMEN - El objetivo de este trabajo es estudiar, desde el punto de vista primal, la eficiencia técnica de una muestra de barcos dedicados a la pesca de merluza en Asturias. Un rasgo característico de esta actividad es la importancia que tienen las capturas de otras especies distintas de la merluza. La naturaleza multiproducto de esta actividad plantea distintas alternativas de modelización. En este trabajo se comparan los resultados obtenidos a partir de la estimación de una función de producción agregada, una función de producción multiproducto y una función de distancia. Los tres modelos se estiman utilizando el estimador intragrupos. En una segunda etapa, los índices de eficiencia se calculan a partir de los efectos individuales una vez eliminada la influencia de variables invariantes en el tiempo. Para la realización del estudio empírico se dispone de un panel de datos que contiene información acerca de la actividad pesquera de once embarcaciones asturianas a lo largo de 1999. SUMMARY - The objective of this paper is to study, following a primal approach, the technical efficiency of a sample of boats which catch hake in Asturias. In this activity the catches of species different from hake are important. The multiproduct nature of this activity raises different modelling alternatives. In this paper we compare the results obtained in the estimation of an aggregate production function, a multiproduct production function, and a distance function. The three models are estimated using the within-groups estimator. After eliminating the influence of time invariant variables, the efficiency indexes are calculated in a second stage using the individual fixed effects. The empirical analysis uses a panel data set of eleven boats in 1999

Eficiencia tecnica en pesquerias multiespecie: una aproximacion primal

RESUMEN: El objetivo de este trabajo es estudiar, desde el punto de vista primal, la eficiencia técnica de una muestra de barcos dedicados a la pesca de merluza en Asturias. Un rasgo característico de esta actividad es la importancia que tienen las capturas de otras especies distintas de la merluza. La naturaleza multiproducto de esta actividad plantea distintas alternativas de modelización. En este trabajo se comparan los resultados obtenidos a partir de la estimación de una función de producción agregada, una función de producción multiproducto y una función de distancia. Los tres modelos se estiman utilizando el estimador intragrupos. En una segunda etapa, los índices de eficiencia se calculan a partir de los efectos individuales una vez eliminada la influencia de variables invariantes en el tiempo. Para la realización del estudio empírico se dispone de un panel de datos que contiene información acerca de la actividad pesquera de once embarcaciones asturianas a lo largo de 1999. SUMMARY: The objective of this paper is to study, following a primal approach, the technical efficiency of a sample of boats which catch hake in Asturias. In this activity the catches of species different from hake are important. The multiproduct nature of this activity raises different modelling alternatives. In this paper we compare the results obtained in the estimation of an aggregate production function, a multiproduct production function, and a distance function. The three models are estimated using the within-groups estimator. After eliminating the influence of time invariant variables, the efficiency indexes are calculated in a second stage using the individual fixed effects. The empirical analysis uses a panel data set of eleven boats in 1999.efficiency, distance function, multiproduct, fisheries, Resource /Energy Economics and Policy, Q22, P11,

Measuring High Dynamic Range Spectral Reflectance of Artworks through an Image Capture Matrix Hyperspectral Camera

Commercial hyperspectral imaging systems typically use CCD or CMOS sensors. These types of sensors have a limited dynamic range and non-linear response. This means that when evaluating an artwork under uncontrolled lighting conditions and with light and dark areas in the same scene, hyperspectral images with underexposed or saturated areas would be obtained at low or high exposure times, respectively. To overcome this problem, this article presents a system for capturing hyperspectral images consisting of a matrix of twelve spectral filters placed in twelve cameras, which, after processing these images, makes it possible to obtain the high dynamic range image to measure the spectral reflectance of the work of art being evaluated. We show the developed system and describe all its components, calibration processes, and the algorithm implemented to obtain the high dynamic range spectral reflectance measurement. In order to validate the system, high dynamic range spectral reflectance measurements from Labsphere&rsquo;s Spectralon Reflectance Standards were performed and compared with the same reflectance measurements but using low dynamic range images. High dynamic range hyperspectral imaging improves the colorimetric accuracy and decreases the uncertainty of the spectral reflectance measurement based on low dynamic range imaging

High-Dynamic-Range Spectral Reflectance for the Segmentation of Paint Pigment: Application to Dalí’s Oil Painting Dos Figuras (1926)

Restorers and curators in museums sometimes find it difficult to accurately segment areas of paintings that have been contaminated with other pigments or areas that need to be restored, and work on the painting needs to be carried out with minimum possible damage. It is therefore necessary to develop measurement systems and methods that facilitate this task in the least invasive way possible. The aim of this study was to obtain high-dynamic-range (HDR) spectral reflectance and spatial resolution for Dalí’s painting entitled Two Figures (1926) in order to segment a small area of black and white pigment that was affected by the contact transfer of reddish pigment from another painting. Using Hypermatrixcam to measure the HDR spectral reflectance developed by this research team, an HDR multispectral cube of 12 images was obtained for the band 470–690 nm in steps of 20 nm. With the values obtained for the spectral reflectance of the HDR cube, the colour of the area of paint affected by the transfer was studied by calculating the a*b* components with the CIELab system. These a*b* values were then used to define two methods of segmenting the exact areas in which there was a transfer of reddish pigment. The area studied in the painting was originally black, and the contamination with reddish pigment occupied 13.87% to 32% of the total area depending on the selected method. These different solutions can be explained because the lower limit is segmentation based on pure pigment and the upper limit considers red as an exclusion of non-black pigment. Over- and under-segmentation is a common problem described in the literature related to pigment selection. In this application case, as red pigment is not original and should be removed, curators will choose the method that selects the highest red area