How does information disclosure affect liquidity? Evidence from an Emerging Market

Cross-sectional models positively relate firm information disclosure with stock liquidity, but dynamic models in news releases days show an opposite relation. We address this puzzle by studying the effects of information arrival on liquidity and its determinants. We use trade and quote data from Colombia for 2015 and 2016, along with the complete database of news releases as reported by companies to the regulator. The results of Panel data and PVAR models suggest that news releases increase both informed and uninformed trading. All in all, the temporal negative effect of news releases on liquidity is explained by increasing asymmetric information

Agrega valor el modelo Black-Litterman en portafo- lios del Mercado Integrado Latinoamericano (MILA)? Evaluación empírica 2008-2016

The Black-Litterman model (BL) has been offered as an alternative to the classical Markowitz Mean-Variance framework, to structure well-diversified portfolios that incorporate visions from fundamental analysts. We apply this model to stock portfolios in the countries of the Mercado Integrado Latinoamericano (MILA): Colombia, Chile, Mexico and Peru, starting from the constituents of the main stock market indexes. As perspectives, we use the historical analyst ́s recommendations in Bloomberg for the period 2008-2016. We find that portfolios created with BL outperform the main index, both in average return and in alpha, in each of the four countries. Moreover, a regional BL portfolio that combines the four BL country portfolios, outperforms a regional Benchmark, measured in dollars, in each one of three alternatives of Us dollar hedge

TulipaProfileFitting.jl: A Julia package for fitting renewable energy time series profiles

This paper introduces the TulipaProfileFitting.jl package, a tool developed in Julia for generating renewable energy profiles that fit a specified capacity factor. It addresses the limitations of naive methods in adjusting existing profiles to match improved technology efficiency, particularly in scenarios lacking detailed weather data or technology specifications. By formulating the problem mathematically, the package provides a computationally efficient solution for creating realistic renewable energy profiles based on existing data. It ensures that the adjusted profiles realistically reflect the improvements in technology efficiency, making it an essential tool for energy modellers in analyzing $CO_2$-neutral energy systems

Tulipa Energy Model: Mathematical Formulation

Tulipa Energy Model aims to optimise the investment and operation of the electricity market, considering its coupling with other sectors, such as hydrogen and heat, that can also be electrified. The problem is analysed from the perspective of a central planner who determines the expansion plan that is most beneficial for the system as a whole, either by maximising social welfare or by minimising total costs. The formulation provides a general description of the objective function and constraints in the optimisation model based on the concept of energy assets representing any element in the model. The model uses subsets and specific methods to determine the constraints that apply to a particular technology or network, allowing more flexibility in the code to consider new technologies and constraints with different levels of detail in the future

Contributions to the knowledge and use of subterranean ecosystems in the municipality of La Paz (Santander)

La Paz es un municipio del suroriente del departamento de Santander, ubicado en la región andina de Colombia, que posee una extensa red de sistemas subterráneos que no ha sido explorada satisfactoriamente a nivel bioespeleológico. Los autores confirmaron 21 ambientes hipogeos para esta zona del departamento, los cuales fueron valorados utilizando información secundaria y visitas de campo. Sin embargo, en este estudio se logró establecer que, a nivel local, se ignora la riqueza kárstica y biológica del municipio, lo cual se evidenció por la ausencia de este conocimiento en los habitantes que, en su mayoría, reconocen la existencia de solo dos cuevas (El Molino y El Indio). La información referente a fauna y flora asociada a estos ecosistemas es insuficiente y escasa; de igual forma, las entidades territoriales encargadas de la administración ambiental no reportaron estrategias de sensibilización ambiental con la comunidad, ni planes de acción o estrategias orientadas a conservación y uso de estos ambientes hipogeos.La Paz is a municipality located in the Southeast of the department of Santander, in the Andean region of Colombia, which has an extensive network of subterranean systems that has not been satisfactorily explored at the bio-speleological level. The authors confirmed 21 hypogean environments for this area of the department, which were assessed using secondary data and field visits. However, in this study it was established that karstic and biological richness in the municipality is ignored, which was evidenced by the absence of this knowledge in the local people, who mostly recognized the existence of only two caves (El Molino and El Indio). Information regarding fauna and flora associated with these ecosystems is insufficient and limited. Similarly, local authorities responsible for environmental management strategies reported no environmental awareness in the community, or action plans oriented to conservation and use of these hypogean environments

Pivotal role of AKT2 during dynamic phenotypic change of breast cancer stem cells

Cancer stem cells (CSC); Dynamic phenotype; Epithelial-to-mesenchymal transition (EMT)Células madre cancerosas (CSC); Fenotipo dinámico; Transición epitelial a mesenquimal (EMT)Cèl·lules mare canceroses (CSC); Fenotip dinàmic; Transició epitelial a mesenquimal (EMT)Therapeutic resistance seen in aggressive forms of breast cancer remains challenging for current treatments. More than half of the patients suffer from a disease relapse, most of them with distant metastases. Cancer maintenance, resistance to therapy, and metastatic disease seem to be sustained by the presence of cancer stem cells (CSC) within a tumor. The difficulty in targeting this subpopulation derives from their dynamic interconversion process, where CSC can differentiate to non-CSC, which in turn de-differentiate into cells with CSC properties. Using fluorescent CSC models driven by the expression of ALDH1A 1(aldehyde dehydrogenase 1A1), we confirmed this dynamic phenotypic change in MDA-MB-231 breast cancer cells and to identify Serine/Threonine Kinase 2 (AKT2) as an important player in the process. To confirm the central role of AKT2, we silenced AKT2 expression via small interfering RNA and using a chemical inhibitor (CCT128930), in both CSC and non-CSC from different cancer cell lines. Our results revealed that AKT2 inhibition effectively prevents non-CSC reversion through mesenchymal to epithelial transition, reducing invasion and colony formation ability of both, non-CSC and CSC. Further, AKT2 inhibition reduced CSC survival in low attachment conditions. Interestingly, in orthotopic tumor mouse models, high expression levels of AKT2 were detected in circulating tumor cells (CTC). These findings suggest AKT2 as a promising target for future anti-cancer therapies at three important levels: (i) Epithelial-to-mesenchymal transition (EMT) reversion and maintenance of CSC subpopulation in primary tumors, (ii) reduction of CTC and the likelihood of metastatic spread, and (iii) prevention of tumor recurrence through inhibition of CSC tumorigenic and metastatic potential.This work was funded by Fondo de Investigaciones Sanitarias (FIS) from ISCIII, Spanish ministry of Economy and Competitiveness, grant PI17/02242 co-financed by The European Regional Development Fund (FEDER); AC15/00092 grant (Target4Cancer project) from Euro-NanoMed II and PENTRI project, financed by Marato TV3, and EvoNano project, funded by European Union's Horizon 2020 FET Open programme under grant agreement. No. 800983. JSR was supported by a post-doctoral grant from Asociacion Espanola Contra el Cancer (AECC)