1,790 research outputs found
Determinants of Africa’s development: An exploratory study
The increasing sustainability and the causes of economic growth in African countries, provide a set of new research questions for development scholars around the World. The possible determinants of this phenomenon are usually considered to be of economic, social, and institutional natures. In this work is assessed which economic, social, and institutional determinants of economic development are important to the development of Africa countries, for the years 1996 and 2014. The similarities amongst countries and the evolution between the two years are also analyzed. A principal components analysis for categorical data to examine the inter-relationships between the indicators in 1996 and also in 2014. An agglomerative clustering algorithm was used through two different methods: ward’s method and complete linkage method (also called furthest neighbor). The Hierarchical Cluster Analysis (HCA) was suited by a k-means algorithm, to obtain an optimal solution and a typology of countries was identified for each year. The main contribution of the work is to make a joint analysis of the three determinants of economic growth and development – economic, social, and institutional, in which the literature is extremely scarce. Results indicate a positive association amongst institutional, economic, and social determinants of development, which means that countries that exhibit a good performance in institutional indicators also have a good performance in economic and social indicators, and vice-versa, although results are not as clear for 2014 as they are for 1996. Additionally, a higher concentration of countries in the two clusters in which these three indicators are better in 2014 (31 countries in 1996 and 49 countries in 2014), seems to indicate a positive evolution for development of African countries from 1996 to 2014. Results show that policy makers should take an integrated view regarding development and economic growth policies and take in consideration both the economic, social, and institutional characteristics of each country. If an economic, social, or institutional policy is designed independently of the other two, this policy will probably fail in reaching its development or economic growth goal, since all these three factors are interconnected.info:eu-repo/semantics/acceptedVersio
Assessing the Role of Carbonyl Adducts, Particularly Malondialdehyde Adducts, in the Development of Dermis Yellowing Occurring during Skin Photoaging
Solar elastosis is associated with a diffuse yellow hue of the skin. Photoaging is related to lipid peroxidation leading to the formation of carbonyl groups. Protein carbonylation can occur by addition of reactive aldehydes, such as malondialdehyde (MDA), 4-hydroxy-nonenal (4-HNE), and acrolein. All the proteins concerned with this modification, and the biological consequences of adduct formation, are not completely identified. The link between yellowish skin and dermal carbonylated proteins induced by aldehyde adducts was investigated. The study was carried out on ex vivo skin samples from sun-exposed or sun-protected areas and on in vitro dermal equivalent models incubated with 5 mM MDA, 4-HNE, or acrolein. The yellow color and the level of MDA, 4-HNE, and acrolein adducts were evaluated. Yellowish color differences were detected in the dermis of sun-exposed skin compared to sun-protected skin and in in vitro models following addition of MDA, 4-HNE, or acrolein. The yellowing was correlated with the carbonyl adducts increasing in the dermis and in in vitro models incubated with aldehydes. The stronger yellowing seemed to be mediated more by MDA than 4-HNE and acrolein. These observations suggest that dermal carbonylation especially induced by MDA result in the yellow hue of dermis and is involved, in part, in the yellowing observed during skin photoaging
Puzzled: Navigating extractive policy information jigsaws for best practice and transparency
This viewpoint article was written in response to our attempt to explore mechanisms that promote financial 'transparency' in the minerals and energy extractive. We controversially forward our opinion that the trajectory of existing transparency mechanisms is likely to generate an obfuscating mass of disclosed information-not 'transparency'. Using a jigsaw analogy, we make a distinction between 'disclosure' and achieving the more challenging 'transparency': it is both being able to have the pieces (disclosure), and put them together to see the big picture. It is just as important to identify missing pieces of the puzzle to prevent selective disclosure. We critically analyze extractive financial policy, and provide an example where a 'best practice' mining securities policy has markedly advanced transparency in a major mining state. The policy substantially reduces government financial risk of a mining company default at no additional cost; reduces costs to industry around ten-fold; incentivises ongoing site rehabilitation; creates a fund for historical abandonments; and; sustains an impressive publically available information instrument of disturbed footprints and associated rehabilitation for every tenement at high precision on an annual basis. Yet it still remains deficient in terms of transparency in particular aspects, of which we clarify and discuss
Calcium-independent stimulation of membrane fusion and SNAREpin formation by synaptotagmin I
Ñeurotransmitter release requires the direct coupling of the calcium sensor with the machinery for membrane fusion. SNARE proteins comprise the minimal fusion machinery, and synaptotagmin I, a synaptic vesicle protein, is the primary candidate for the main neuronal calcium sensor. To test the effect of synaptotagmin I on membrane fusion, we incorporated it into a SNARE-mediated liposome fusion assay. Synaptotagmin I dramatically stimulated membrane fusion by facilitating SNAREpin zippering. This stimulatory effect was topologically restricted to v-SNARE vesicles (containing VAMP 2) and only occurred in trans to t-SNARE vesicles (containing syntaxin 1A and SNAP-25). Interestingly, calcium did not affect the overall fusion reaction. These results indicate that synaptotagmin I can directly accelerate SNARE-mediated membrane fusion and raise the possibility that additional components might be required to ensure tight calcium coupling
Hyperprolinemia as a clue in the diagnosis of a patient with psychiatric manifestations
Lately, microdeletions of the 22q region, responsible for DiGeorge syndrome or velocardiofacial syndrome, have been increasingly related to neuropsychiatric disorders including schizophrenia and bipolar disorder. These manifestations seem to be related to certain genes located in the hemideleted region such as the proline dehydrogenase (PRODH) and the catechol-o-methyltransferase (COMT) genes. We describe a teenager who started his adolescent psychiatric care presenting cognitive impairment, irritable mood and aggressive behaviour with schizophrenia-like symptoms that scored 153 in the Positive and Negative Symptoms Scale (PANSS) assessment. Worsening of symptoms when the patient was treated with valproic acid, and plasma aminoacids showing an increase in alanine and proline, suggested a mitochondrial involvement of the proline metabolic pathway. Mild dysmorphic features also suggested a possible 22q11 deletion syndrome that was confirmed. A mutation for Hyperprolinemia type I was also detected. Knowledge of the correct diagnosis was crucial for an adequate treatment.info:eu-repo/semantics/publishedVersio
Fluorescence in nanostructured fulleride films
Applied Physics Letters, 89Nanostructuring of fullerene C60 beam deposited films is achieved by electrochemical reduction in a potassium hydroxide aqueous solution. Alkali fulleride clusters are formed at the electrode, as it
is illustrated by cyclic voltammetry, x-ray diffraction, and scanning tunneling microscopy.
Fluorescence emission from fluorophore doped fullerene reduced films was investigated by
fluorescence spectroscopy and scanning near-field optical microscopy. These techniques lead to results which also fit such nanometer-sized fulleride cluster interpretation. In particular, the fluorophore fluorescence lifetime decreases as long as aggregation in the film is more effective,which occurs with the increase of film thickness
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