Suchergebnisse

Abstract
Background
The concentration of heavy metals and their spatial distribution in surface sediments collected from the Thondi coast, Palk Bay, South India were analysed in this study. The sediment grain size, pH, EC, and major elements (Fe, and Al), heavy metal concentrations (Mn, Cr, Zn, Cd, Ni, Cu, and Pb) were determined and the values for the geoaccumulation index (Igeo), enrichment factor (EF), potential contamination index (Cp), potential ecological risk index (RI), contamination factor (CF), modified contamination degree (mCd), degree of contamination (Cd), and potential contamination factors (Cp) were calculated based on their background values to determine the pollution level of the study area. Multivariate analysis such as Pearson's correlation coefficient, principal component analysis/factor analysis (PCA/FA), cluster analysis, and regression analysis are a versatile method for identifying heavy metal sources and determining the relationship between pollutants in marine sediment.

Results
The pollution indices, namely EF, CF, Cd, mCd, CP, RI, and Igeo, revealed that the heavy metal contamination was due to Cd, while a moderate level of contamination was caused by Cu, Zn, Pb, and Cr. The principal component analysis and correlation matrix analysis showed a strong positive loading for Cd due to its high level of contamination in the study area. Anthropogenic inputs such as municipal wastewater, domestic sewage discharge, fishing harbour activities, and industrial and aquaculture wastes led to the increased Cd concentration in the study area. Moreover, the pollution load index revealed that the sediments were polluted by heavy metals.

Conclusion
The findings of this study revealed that the increased concentration of heavy metals in the study area increases the toxicity in the marine environment, thus affecting the ecosystem.

Magnetic Fluid Hyperthermia mediated by iron oxide nanoparticles is one of the most promising therapies for cancer treatment. Among the different candidates, magnetite and maghemite nanoparticles have revealed to be some of the most promising candidates due to both their performance and their biocompatibility. Nonetheless, up to date, the literature comparing the heating ef ciency of magnetite and maghemite nanoparticles of similar size is scarce. To ll this gap, here we provide a comparison between commercial Synomag Nano owers (pure maghemite) and bacterial magnetosomes (pure magnetite) synthesized by the magnetotactic bacterium Magnetospirillum gryphiswaldense of hDi 40 45 nm. Both types of nanoparticles exhibit a high degree of crystallinity and an excellent degree of chemical purity and stability. The structural and magnetic properties in both nanoparticle ensembles have been studied by means of X Ray Diffraction, Transmission Electron Microscopy, X Ray Absorption Spectroscopy, and SQUID magnetometry. The heating ef ciency has been analyzed in both systems using AC magnetometry at several eld amplitudes (0 88 mT) and frequencies (130, 300, and 530 kHz). ; This work was supported in part by the Spanish "Ministerio de Ciencia, Investigación y Universidades'' under Project MAT2017-83631-C3-R, and in part by the Nanotechnology in Translational Hyperthermia (HIPERNANO) under Grant RED2018-102626-T. The work of Elizabeth M. Jefremovas was supported by the Beca Concepción Arenal through the Gobierno de Cantabria-Universidad de Cantabria under Grant BDNS: 406333. The work of Irati Rodrigo was supported by the Programa de Perfeccionamiento de Personal Investigador Doctor (Gobierno Vasco) under Grant POS-2020-1-0028 and Grant IT-1005-16. The work of Lourdes Marcano was supported by the Postdoctoral Fellowship from the Basque Government under Grant POS-2019-2-0017.

This paper focuses on SMEs from the Latin American region and aims to build on existing literature on the emergence of the institution-based view in combination with the resource-based view. We contribute to existing literature by extending the application of the aforementioned theories to firms in three under-researched countries in this region. Specifically, we contribute to the extant literature by providing empirical insights on how home country–specific resources and firm-specific resources can affect the internationalization speed of SMEs in Latin American region. In order to achieve our objectives, we empirically examine the role of economic freedom (EF), prior business/international experience, and firm size on speed of internationalization. We use a dataset of Latin American SMEs, employing Poisson and negative binomial (NB) regression techniques. Our data cover three main Latin American Pacific Rim economies—Chile, Colombia, and Peru—with similar economic specializations, geographical borders, and economic growth dynamics. We find that (1) some parts of Economic Freedom Index (EFI) accelerate the speed of internationalization, whereas other areas slow it down or have no effect. Specifically, the closer to full EF the home country is in terms of regulations and government, the shorter the time to internationalize. (2) More experienced management teams are more likely to translate their knowledge into faster international market entry, but this pays off only for larger sized SMEs in contrast to smaller ones due to complementarities between managerial resources and physical, financial, and organizational resources. (3) Finally, industry, firm location, and country destination can only weakly explain the speed of internationalization. The findings add to the literature on SME internationalization in emerging markets and point towards potential policies to stimulate growth by SMEs in these markets.

<b><i>Background:</i></b> Alcohol use disorder (AUD) is to a high degree heritable, and in clinical practice it is common to assert presence of alcohol abuse family history (FH) in treatment-seeking AUD patients. Patients with AUD also exhibit cognitive deficits, including elevated impulsivity and impairments in executive functions (EF), but less is known regarding the relation between FH and these cognitive domains. The aim of the current study was to investigate if alcohol abuse FH in AUD patients is associated with a specific cognitive profile. <b><i>Methods:</i></b> Patients with AUD (<i>n</i> = 197) from Sweden (<i>n</i> = 106) and Belgium (<i>n</i> = 91) were recruited. Self-rated impulsivity was assessed by the Barratt Impulsiveness Scale (BIS). EF assessed were response inhibition (stop signal task), attention (rapid visual processing task), and working memory (digit span). A series of linear regression models were run to explore the effect of FH on cognitive outcomes. <b><i>Results:</i></b> A FH of alcohol abuse was associated with elevated score in self-rated impulsivity assessed by the BIS, with the greatest effect on the subscale of nonplanning. There was no statistically significant association between FH and any of the other neuropsychological task outcomes. <b><i>Conclusion:</i></b> Presence of alcohol abuse FH within AUD patients could be a marker of higher impulsivity, which may have clinical implications regarding diagnostic evaluation and treatment.

Abstract
Street dust forms as a result of the interaction of the atmosphere, lithosphere (pedosphere) and anthroposphere and can be regarded as an index of the condition of the environment in urban areas. At the end of the twentieth century, there was a significant decrease in heavy metal emissions in Europe, but not so intensive in Poland. The question arises: Is the intensity of pollution still decreasing? The study objective was to assess changes in street dust pollution with heavy metals in Lublin (E Poland) in the years 2013 and 2018. The sample collection sites (68) were located within streets with a varying intensity of motor traffic. Cd, Cr, Cu, Ni, Pb and Zn concentrations were determined in two dust fractions, 63–200 μm and < 63 μm, by means of an X-ray fluorescence spectrometer. The levels of street dust pollution with heavy metals, expressed both in absolute concentrations and geochemical indices, were lower in 2018 than those in 2013. The clearest decrease of concentration levels occurred within the main roads, in the 63–200 μm fraction for Cu and Cd, and in both fractions for Pb. The mean concentrations of the investigated metals, normalised to the background values, are in the following order for both fractions in 2013 and 2018: Zn > Cd > Cu > Cr > Pb > Ni. Metals form the following order for Igeo and EF: Zn > Cd > Cu > Pb > Cr > Ni. This order is slightly different for the ecological risk factor: Cd > Cu > Pb > Zn > Cr > Ni. In general, street dust in Lublin does not show contamination with Cr, Ni and Pb. Igeo and EF indices show moderate levels of pollution with Cu, Cd and Zn.

Sequential extraction or chemical fractionation of heavy metals allows inferences to be made about their origin, occurrence, bioavailability, toxic potential and environmental contamination. Thus, the present study aimed to assess the distribution of Cu, Mn, Ni, Pb and Zn among the different soil fractions and landscape compartments of a yellow latosol cultivated with vegetables. Soil samples were collected from five areas cultivated with tomato (Lycopersicon esculentum, Mill.), lettuce (Lactuca sativa), chili pepper (Capsicum annuum L.) and chard (Beta vulgaris L.) in different slope positions (upper, middle, lower), and four reference areas (native forest), at a depth of 0.00 - 0.20 m. Heavy metal levels were also assessed in water used to irrigate the crops and for human consumption by collecting 200 ml of water samples from reservoirs. The soil samples were sequentially fractionated to quantify the concentrations of adsorbed Cu, Mn, Ni, Pb and Zn in the exchangeable (EF), organic matter (OF), amorphous and crystalline iron oxide fractions (AFeOx and CFeOx). Landscape position only interfered significantly in heavy metal adsorption in the soil for Cu and Ni associated with CFeOx and Zn bound to the EF in the farming areas. The highest Cu, Ni, Pb and Zn levels were found in the fractions with less stable chemical bonds (bound to organic matter), in addition to a strong affinity between Cu, Zn and Mn and the oxide fractions (AFeOx + CFeOx). The low affinity of Pb and Ni for the AFeOx and CFeOx fractions indicates greater contamination potential for the water reservoirs. In the short term, organic matter is the main source of remediation for heavy metal contamination in soil, making it important to adopt conservation practices aimed at reducing OM losses.

El artículo analiza los diversos efectos de los acontecimientos del 11 de septiembre a varios niveles. En primer lugar dentro de EE.UU., en las relaciones entre el ejecutivo y el Congreso, en la opinión pública, y en el incremento del nacionalismo. Luego, se exponen las continuidades y variaciones en las relaciones entre EE.UU. y Europa, Rusia, China y América Latina. Finalmente, se analizan las circunstancias tradicionales y nuevas en las relaciones con el Medio Oriente y Asia Central, así como los nuevos equilibrios de poder. A partir de una tabla temática que incluye temas políticos, económicos y de seguridad internacional, el autor concluye que el 11 de septiembre produjo cambios importantes en la percepción del mundo desde los EE.UU., pero no necesariamente cambios cualitativos en el orden mundial. ; This article analyses sorne of the various ef fects provoked by the Sept­ ember the ¡ ¡rn e vents. First, the author looks at those ef fects at the interna/ leve!, in the relations between the executive and Congress, in the media and in the increase of nationalism process. Second, the continui­ ties and dif ferences in the relatíons between Europe, the US, Russia, China and Latín America, are looked at. Final/ y, tra,dítional and new circumstances in the relations between the US, the Middle East and Cen­ tral Asia, are a/so observed, to.gether with the creation of new power equilibrium. Based on theme analyses of political, economic, and inter­ national securí ty tapies, the author concludes that the September the 1 1 rn events produced great changes in the perce ptíons the US had of the world, but díd not necessaril y produce qualitative changes in the world arder.