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Mining operations disrupt the structure of rock layers, leading to surface deformations and potential mining damage. This issue has been extensively studied since the 19th century using various analytical, geometric-integral, and stochastic methods. Since the 1990s, numerical methods have been increasingly applied to determine changes in the stress and strain states of rock masses due to mining activities. These methods account for numerous additional factors influencing surface deformation, offering significant advantages over classical approaches. However, modelling rock masses presents challenges, particularly in calibrating the mechanical parameters of rock layers, an area extensively researched with numerous publications. In this study, we determined the mechanical parameter values of rock layers at the advancing mining front using a custom Python script and Finite Element Method (FEM) numerical models. We also introduced a modification to evaluate the error of the estimated parameter values. Numerical analyses were conducted for the Piast–Ziemowit mine region in Poland, utilizing mining, geological, and surveying data. Our results demonstrate that accurate calibration of mechanical parameters is crucial for reliable predictions of surface deformations. The proposed methodology enhances the precision of numerical models, providing a more robust framework for assessing the impact of mining activities on rock layers. [ABSTRACT FROM AUTHOR]

The article presents a methodology for determining the value of the expansion coefficient of a reconsolidated caving zone in the context of forecasting the rise in underground mine water levels and consequent surface subsidence caused by the process of flooding the closed coal mines. The paper also provides a brief characterisation of analytical predictive models regarding surface subsidence during the process of flooding coal mines. In order to describe the vertical deformation of the reconsolidated porous rock mass in the caving zone, a linear-elastic medium of Biot was utilised. The conducted theoretical calculations demonstrate a high agreement with the results obtained through the identification of the expansion coefficient parameter based on the analysis of in-situ subsidence measurements in Dutch and German mining areas. The proposed methodology was applied to a real case study involving the forecasting of the impact of the flooding process on the underground workings of the German Ibbenbüren mine. The article constitutes a significant contribution to the field of forecasting the rise in underground mine water levels and surface subsidence during the process of flooding closed coal mines. The presented methodology and obtained results can be valuable for researchers, engineers, and decision-makers involved in the planning and management of mining areas. [ABSTRACT FROM AUTHOR]

This paper presents one of the environmental problems occurring during underground mine closures: according to the underground coal mine closure programme in Germany, the behaviour of the land surface caused by flooding of the entire planned mining area - the Ruhr District - had to be addressed. It was highlighted that water drainage would need to be continuous; otherwise, water levels would rise again in the mining areas, resulting in flooding of currently highly urbanised zones. Based on the variant analysis, it was concluded that the expected uniform ground movements caused by the planned rise in the mining water levels (comprising a part of two concepts - flooding up to the level of -500 m a.s.l. and -600 m a.s.l.), in the RAG Aktiengesellschaft mines, will not result in new mining damage to traditional buildings. The analysis included calculations of the maximum land surface uplift and the most unfavourable deformation factor values on the land surface, important from the point of view of buildings and structures: tilt T, compressive strain ɛ- and tensile strain ɛ+. The impact of flooding on potential, discontinuous land surface deformation was also analysed. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In contemporary discourses, the lives of migrants are often marginalised and silenced. For this reason, bringing the theme of migrants' identities to the foreground in literary research appears to be increasingly important. This article discusses the experiences of Haitian immigrants to the US as narrated by the Haitian-American author Edwidge Danticat. I explore the theme of making a transnational home in her novel Breath, Eyes, Memory (1994) and short stories from the collection Everything Inside (2019). The analysis is based on a combination of two theories: Steven Vertovec's theory of transnationalism and Paul Ricoeur's philosophy of narrative identity, which enable interpreting intergenerational identity changes, certain methods of cultural reproduction, and "little" cultural cross-connectedness of "family and household" (Vertovec 2009: 3-18) in the context of personal identity understood as formed through narratives. This article focuses on the transition from a Haitian home to an American one as an important part of identity-formation processes. It also views a migrant's journey as still incomplete after coming to the US and requiring "emplotting" (De Fina 2003: 17) its fragmented events into stories. The article attempts to demonstrate intangible ways of creating a transnational home and domestic methods of narrating and negotiating one's cultural identity in Danticat's fiction. I claim that Danticat's works narrate personal experiences to generate a "refigured" understanding of time and transnational ties within the family sphere. [ABSTRACT FROM AUTHOR]

Copyright of Mineral Resources Management / Gospodarka Surowcami Mineralnymi is the property of Mineral & Energy Economy Research Institute of the Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Opioid antagonist treatments reduce alcohol drinking in rodent models and in alcohol-dependent patients, with variable efficacy across different studies. These treatments may suffer from the development of tolerance and opioid receptor supersensitivity, as suggested by preclinical models showing activation of these processes during and after subchronic high-dose administration of the short-acting opioid antagonist naloxone. In the present study, we compared equipotent low and moderate daily doses of naltrexone and nalmefene, two opioid antagonists in the clinical practice for treatment of alcoholism. The antagonists were given here subcutaneously for 7 days either as daily injections or continuous osmotic minipump-driven infusions to alcohol-preferring AA rats having trained to drink 10% alcohol in a limited access protocol. One day after stopping the antagonist treatment, [35 S]GTPγS autoradiography on brain cryostat sections was carried out to examine the coupling of receptors to G protein activation. The results prove the efficacy of repeated injections over infused opioid antagonists in reducing alcohol drinking. Tolerance to the reducing effect on alcohol drinking and to the enhancement of G protein coupling to μ-opioid receptors in various brain regions were consistently detected only after infused antagonists. Supersensitivity of κ-opioid receptors was seen in the ventral and dorsal striatal regions especially by infused nalmefene. Nalmefene showed no clear agonistic activity in rat brain sections or at human recombinant κ-opioid receptors. The findings support the as-needed dosing practice, rather than the standard continual dosing, in the treatment of alcoholism with opioid receptor antagonists. [ABSTRACT FROM AUTHOR]

Background: In recent years there has been a large increase in the use of substituted cathinones such as mephedrone (4-methylmethcathinone, 4-MMC), a psychostimulant drug that shows a strong resemblance to methamphetamine (METH). Unlike METH, which can produce clear long-term effects, the effects of 4-MMC have so far remained elusive. We employ manganese-enhanced magnetic resonance imaging (MEMRI), a highly sensitive method for detecting changes in neuronal activation, to investigate the effects of METH and 4-MMC on the brain. Methods: In Wistar rats we performed a MEMRI scan two weeks after binge treatments (twice daily for 4 consecutive days) of METH (5 mg/kg) or 4-MMC (30mg/kg). Furthermore, locomotor activity measurements and novel object recognition tests were performed. Results: METH produced a widespread pattern of decreased bilateral activity in several regions, including the nucleus accumbens, caudate putamen, globus pallidus, thalamus, and hippocampus, as well as several other cortical and subcortical areas. Conversely, 4-MMC produced increased bilateral activity, anatomically limited to the hypothalamus and hippocampus. Drug treatments did not affect the development of locomotor sensitization or novel object recognition performance. Conclusions: The pattern of decreased brain activity seen after METH corresponds closely to regions known to be affected by this drug and confirms the validity of MEMRI for detecting neuroadaptation two weeks after amphetamine binge treatment. 4-MMC, unlike METH, produced increased activity in a limited number of different brain regions. This highlights an important difference in the long-term effects of these drugs on neural function and shows precisely the anatomical localization of 4-MMC-induced neuroadaptation. [ABSTRACT FROM AUTHOR]

Background: In recent years there has been a large increase in the use of substituted cathinones such as mephedrone (4-methylmethcathinone, 4-MMC), a psychostimulant drug that shows a strong resemblance to methamphetamine (METH). Unlike METH, which can produce clear long-term effects, the effects of 4-MMC have so far remained elusive. We employ manganese-enhanced magnetic resonance imaging (MEMRI), a highly sensitive method for detecting changes in neuronal activation, to investigate the effects of METH and 4-MMC on the brain., Methods: In Wistar rats we performed a MEMRI scan two weeks after binge treatments (twice daily for 4 consecutive days) of METH (5 mg/kg) or 4-MMC (30 mg/kg). Furthermore, locomotor activity measurements and novel object recognition tests were performed., Results: METH produced a widespread pattern of decreased bilateral activity in several regions, including the nucleus accumbens, caudate putamen, globus pallidus, thalamus, and hippocampus, as well as several other cortical and subcortical areas. Conversely, 4-MMC produced increased bilateral activity, anatomically limited to the hypothalamus and hippocampus. Drug treatments did not affect the development of locomotor sensitization or novel object recognition performance., Conclusions: The pattern of decreased brain activity seen after METH corresponds closely to regions known to be affected by this drug and confirms the validity of MEMRI for detecting neuroadaptation two weeks after amphetamine binge treatment. 4-MMC, unlike METH, produced increased activity in a limited number of different brain regions. This highlights an important difference in the long-term effects of these drugs on neural function and shows precisely the anatomical localization of 4-MMC-induced neuroadaptation., (© The Author 2015. Published by Oxford University Press on behalf of CINP.)