84 research outputs found
Social Network Analytics for Advanced Bibliometrics: Referring to Actor Roles of Management Journals instead of Journal Rankings
Impact factors are commonly used to assess journals relevance. This implies a simplified view on science as a single-stage linear process. Therefore, few top-tier journals are one-sidedly favored as outlets, such that submissions to top-tier journals explode whereas others are short of submissions. Consequently, the often claimed gap between research and practical application in application-oriented disciplines as business administration is not narrowing but becoming entrenched. A more complete view of the scientific system is needed to fully capture journals ´ contributions in the development of a discipline.
Simple citation measures, as e.g. citation counts, are commonly used to evaluate scientific work. There are many known dangers of miss- or over-interpretation of such simple data and this paper adds to this discussion by developing an alternative way of interpreting a discipline based on the positions and roles of journals in their wider network. Specifically, we employ ideas from the network analytic approach. Relative positions allow the direct comparison between different fields. Similarly, the approach provides a better understanding of the diffusion process of knowledge as it differentiates positions in the knowledge creation process. We demonstrate how different modes of social capital create different patterns of action that require a multidimensional evaluation of scientific research. We explore different types of social capital and intertwined relational structures of actors to compare journals with different bibliometric profiles. Ultimately, we develop a multi-dimensional evaluation of actor roles based upon multiple indicators and we test this approach by classifying management journals based on their bibliometric environment
Routine sample preparation and HPLC analysis for ascorbic acid (vitamin C) determination in wheat plants and Arabidopsis leaf tissues
Plants have developed various mechanisms to protect themselves against oxidative stress. One of the most
important non-enzymatic antioxidants is ascorbic acid. There is thus a need for a rapid, sensitive method
for the analysis of the reduced and oxidised forms of ascorbic acid in crop plants. In this paper a simple,
economic, selective, precise and stable HPLC method is presented for the detection of ascorbate in plant
tissue. The sensitivity, the short retention time and the simple isocratic elution mean that the method is
suitable for the routine quantification of ascorbate in a high daily sample number. The method has been
found to be better than previously reported methods, because of the use of an economical, readily available
mobile phase, UV detection and the lack of complicated extraction procedures. The method has been
tested on Arabidopsis plants with different ascorbate levels and on wheat plants during Cd stress
Derivative UV/Vis spectroelectrochemistry in a thin-layer regime: deconvolution and simultaneous quantification of ascorbic acid, dopamine and uric acid
In this work, UV/Vis spectroelectrochemistry (SEC), in a thin-layer regime and parallel configuration, is selected to solve a
complex mixture that contains dopamine (DA), ascorbic acid (AA) and uric acid (UA). These molecules, like many other
biological compounds, are assuming a highly important place in analytical and biomedical fields due to the fundamental role
that they play in human metabolism. In addition, low or high levels of these compounds are associated with diseases such as
Parkinson’s disease. For this reason, the quantification of these biomolecules is becoming increasingly critical. However, some
drawbacks must be overcome, because the three molecules coexist in the human body, and the species are subject to mutual
interference. In fact, they are all oxidized at similar potentials, and their UV/Vis absorption bands overlap, greatly complicating
their quantification. For this reason, derivative SEC together with suitable chemometric tools such as PARAFAC are proposed to
solve this complex matrix. This technique allows us to separate the contribution of each of these molecules present in a sample
and to quantify all of them, achieving high resolution and reproducibility. Besides, detection limits at the micromolar level are
achieved for DA, AA and UA in mixture solutions. This work thus demonstrates the great potential for derivative potentiodynamic
SEC combined with the appropriate chemometric tools in solving complex mixtures, a field where SEC is still taking the
first steps.Ministerio de Economía y Competitividad (Grants CTQ2017-83935-RAEI/
FEDER, UE), Junta de Castilla y León (Grant BU297P18) and
Ministerio de Ciencia, Innovación y Universidades (RED2018-102412-
T). F.O. is grateful for the contract funded by Junta de Castilla y León, the
European Social Fund and the Youth Employment Initiative. J.G.R.
thanks theMinisterio de Economía y Competitividad for his postdoctoral
contract (CTQ2017-83935-R AEI/FEDER, UE)
Reversibile transdifferentiation of secretory epithelial cells into adipocytes in the mammari gland
Mammalian breast adipose tissue is replaced by a milk-secreting gland during pregnancy; the reverse process takes place upon interruption of lactation. Morphological and bromodeoxyuridine studies provide indirect evidence that mouse mammary adipocytes transform into secretory epithelial cells during pregnancy and revert to adipocytes after lactation. By using the Cre-loxP recombination system we show that the mammary gland of whey acidic protein (WAP)-Cre/R26R mice, in which secretory epithelial cells express the lacZ gene during pregnancy, contains labeled adipocytes during involution. Conversely, adipocyte P2-Cre/R26R mice, in which adipocytes are labeled before pregnancy, contain labeled secretory epithelial cells during pregnancy. We conclude that reversible adipocyte-to-epithelium and epithelium-to-adipocyte transdifferentiation occurs in the mammary gland of adult mice during pregnancy and lactation
Reversible transdifferentiation of secretory epithelial cells into adipocytes in the mammary gland
Mammalian breast adipose tissue is replaced by a milk-secreting gland during pregnancy; the reverse process takes place upon interruption of lactation. Morphological and bromodeoxyuridine studies provide indirect evidence that mouse mammary adipocytes transform into secretory epithelial cells during pregnancy and revert to adipocytes after lactation. By using the Cre-loxP recombination system we show that the mammary gland of whey acidic protein (WAP)-Cre/R26R mice, in which secretory epithelial cells express the lacZ gene during pregnancy, contains labeled adipocytes during involution. Conversely, adipocyte P2-Cre/R26R mice, in which adipocytes are labeled before pregnancy, contain labeled secretory epithelial cells during pregnancy. We conclude that reversible adipocyte-to-epithelium and epithelium-to-adipocyte transdifferentiation occurs in the mammary gland of adult mice during pregnancy and lactation
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