831 research outputs found
Structural and immunological similarities between high molecular weight zinc ion-dependent p-nitrophenylphosphatase and fructose-1,6-bisphosphate aldolase from bovine liver
No full textHigh molecular weight zinc ion-dependent acid p-nitrophenylphosphatase (HMW-ZnAPase) was purified from bovine liver to homogeneity as judged by native and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The partial sequence of the purified enzyme electroblotted on PVDF membrane reveals a 95% sequence homology with human and bovine liver fructose-1,6-bisphosphate aldolase isozyme B (FALD B). FALD B was isolated from bovine liver using an affinity elution from phosphocellulose column. FALD B from bovine liver shows a native and subunit molecular weight that is indistinguishable from that of HMW-ZnAPase. In addition, an affinity purified antiserum raised in rabbits against purified HMW-ZnAPase cross-reacts with bovine liver FALD B and rabbit muscle isozymes. Despite these similarities, HMW-ZnAPase does not show FALD activity and bovine liver FALD does not display any zinc ion-p-nitrophenylphosphatase activity. These results suggested the existence of structural and immunological similarities between bovine liver HMW-ZnAPase and FALD B. Differences in some amino acid residues in enzyme activity indicate that they may be involved in different biochemical functions. © 2001 Elsevier Science B.V
Online resources for mathematics in the scientific virtual reference desk
No full textThe present work briefly describes the Virtual Reference Desk for mathematics elaborated during the time I worked at the CERN Library (European Laboratory for Particle Physics or Laboratoire européen pour la physique des particules) in Geneva. This instrument is dedicated to the CERN librarians, with whom I have shared important moments of my professional career. In particular, I would like to gratefully acknowledge their valuable co-operation and assistance during our time spent working together. The Web metasource is comprised of three directories, annotated and interrelated with dual application: The first is intended as a work tool for librarians working in mathematics libraries, but above all for librarians of high energy physics, who more often than not must turn to mathematics and the use of mathematical applications and models for the physical sciences and in particular particle physics. The second is an on-line resource for mathematics; that is, a Virtual Reference Desk for the community of mathematicians, with whom I have been collaborating for some twenty years at the University of Padova. The bibliographical instrument is born from the need to have at our disposal a scientific Virtual Reference Desk created according to the needs of those working in physics and mathematics libraries – a tool which is comprised of materials collected during years of work as much as material available on-line through the use of new technologies
TNF-α Levels Are Increased in Patients with Subjective Cognitive Impairment and Are Negatively Correlated with β Amyloid-42
No full textThe role of tumor necrosis factor-α (TNF-α) in Alzheimer’s disease (AD) has recently become a topic of debate. TNF-α levels increase in the blood of patients with AD, and amyloid beta (Aβ) plaques contain TNF-α deposits. The therapeutic efficacy of blocking TNF-α in patients with AD remains controversial as it is mostly based on preclinical studies. Thus, whether and how TNF-α contributes to amyloidogenic processes in AD is still an open question to be addressed. We analyzed plasma TNF-α and Aβ42 levels in patients with subjective cognitive impairment (SCI), mild cognitive impairment (MCI), and AD, and in healthy volunteers (HLT). In addition, we performed correlation analysis to evaluate whether changes in plasma TNF-α levels correlate with cognitive decline, Aβ42 levels, age, and BMI, which are all factors considered to contribute to or predispose individuals to AD. We found that TNF-α and Aβ42 plasma levels were higher in patients with AD than in HLT individuals. High TNF-α levels were also observed in patients with SCI, in whom TNF-α and Aβ42 levels were negatively correlated. Notably, TNF-α did not affect the amyloidogenic pathway in human microglial cultures exposed to 48 h of incubation, although it did trigger neuroinflammatory processes. These results imply that high TNF-α levels are more likely to be a clinical condition linked to AD than are direct contributors. Nonetheless, elevated levels of TNF-α in early-stage patients, like those with SCI and MCI, may provide a distinguishing feature for identifying clinical profiles that are at risk of having a poorer outcome in AD and could benefit from tailored therapies
Intervista con Antonella De Robbio, Responsabile del Settore Progetti e Biblioteca Digitale del Centro d'Ateneo per le Biblioteche CAB dell' Università di Padova e Referente per il diritto d'autore del Sistema Bibliotecario di Ateneo
No full textThe interview with Antonella De Robbio – manager of the “Project Sector and Digital Library” for CAB (Centro di Ateneo per le Biblioteche) of the University of Padua and copyright expert for Sistema Bibliotecario di Ateneo – was published in Pinali news.
Antonella De Robbio answered the following questions:
1) How to deal with the issues of author’s intellectual and economic rights in the context of scientific publishing and digital library?
2) What is the influence of the digital approach on the traditional ways to create and disseminate scientific communication?
3) In your opinion, can the experiences of University Press and the Open Archives represent the path to follow in order to overcome the paradox that a scientific author is also the user of his publisher?
4) Which are the outcomes of the fight between copyright and copyleft?
5) Which of these approaches are more suitable to label the metaphor of the “Society of Knowledge”
Advances in peripheral blood biomarkers of patients with Alzheimer’s disease: Moving closer to personalized therapies
No full textRecently, measurable peripheral biomarkers in the plasma of patients with Alzheimer's disease (AD) have gained considerable clinical interest. Several studies have identified one or more blood signatures that may facilitate the development of novel diagnostic and therapeutic strategies. For instance, changes in peripheral amyloid β42 (Aβ42) levels have been largely investigated in patients with AD and correlated with the progression of the pathology, although with controversial results. In addition, tumor necrosis factor α (TNFα) has been identified as an inflammatory biomarker strongly associated with AD, and several studies have consistently suggested the pharmacological targeting of TNFα to reduce systemic inflammation and prevent neurotoxicity in AD. Moreover, alterations in plasma metabolite levels appear to predict the progression of systemic processes relevant to brain functions. In this study, we analyzed the changes in the levels of Aβ42, TNFα, and plasma metabolites in subjects with AD and compared the results with those in healthy elderly (HE) subjects. Differences in plasma metabolites of patients with AD were analyzed with respect to Aβ42, TNFα, and the Mini-Mental State Examination (MMSE) score, searching for plasma signatures that changed simultaneously. In addition, the phosphorylation levels of the Tyr682 residue of the amyloid precursor protein (APP), which we previously proposed as a biomarker of AD, were measured in five HE and five AD patients, in whom the levels of Aβ42, TNFα, and two plasma lipid metabolites increased simultaneously. Overall, this study highlights the potential of combining different plasma signatures to define specific clinical phenotypes of patient subgroups, thus paving the way for the stratification of patients with AD and development of personalized approaches
Literacy in Neapolitan Women's Convents in the Middle Ages and the Contribution of Digital Archives on Monasterium.Net
No full textAntonella Ambrosio seeks a viable way of carrying out research on this topic: the palaeographic analysis of the few available sources using a multidisciplinary approach that combines diplomatics, archival, and historical research. This approach ensures the appropriate contextualization of the source both historically and culturally. In "Literacy in Neapolitan Women's Convents: An Example of Female Handwriting in a Late Fifteenth-Century Accounts Ledger", Ambrosio provides a case study, analysing a single piece of handwriting evidence. The source is an accounts ledger from the Dominican convent of Santi Pietro e Sebastiano compiled in the second half of the fifteenth century, from 1485 to 1496. Using an analytical approach, the author has identified the handwriting of a particular (anonymous) nun from the convent; Ambrosio studies the script the nun used and formulates hypotheses about her cultural background and how she learned to write. The palaeographic analysis is fully contextualized thanks to the reconstruction of the old convent archive, a reconstruction helped by using digital technologies now accessible online at Monasterium.net. As Ambrosio's work demonstrates, technological advances may aid codicological work but careful palaeographic analysis is necessary to ascertain the participation of female scribes. In this case we witness the scribal development of a nun who began with a basic knowledge of writing and who went on to perform her practical task not well but adequately for the purpose
Application of Sebum Lipidomics to Biomarkers Discovery in Neurodegenerative Diseases
No full textLipidomics is strategic in the discovery of biomarkers of neurodegenerative diseases (NDDs). The skin surface lipidome bears the potential to provide biomarker candidates in the detection of pathological processes occurring in distal organs. We investigated the sebum composition to search diagnostic and, possibly, prognostic, biomarkers of Alzheimer’s disease (AD) and Parkinson’s disease (PD). The observational study included 64 subjects: 20 characterized as “probable AD with documented decline”, 20 as “clinically established PD”, and 24 healthy subjects (HS) of comparable age. The analysis of sebum by GCMS and TLC retrieved the amounts (µg) of 41 free fatty acids (FFAs), 7 fatty alcohols (FOHs), vitamin E, cholesterol, squalene, and total triglycerides (TGs) and wax esters (WEs). Distributions of sebum lipids in NDDs and healthy conditions were investigated with multivariate ANOVA-simultaneous component analysis (ASCA). The deranged sebum composition associated with the PD group showed incretion of most composing lipids compared to HS, whereas only two lipid species (vitamin E and FOH14:0) were discriminant of AD samples and presented lower levels than HS sebum. Thus, sebum lipid biosynthetic pathways are differently affected in PD and AD. The characteristic sebum bio-signatures detected support the value of sebum lipidomics in the biomarkers search in NDDs
Literacy in Neapolitan Women’s Convents: An Example of Female Handwriting in a Late Fifteenth-Century Accounts Ledger
No full textThis paper is about a research i on the literacy and writing skills of Neapolitan sisters in medieval convents, due to the lack of adequate historical study of such nuns and the extremely complex nature of the documentary sources. Surviving evidence is scattered far and wide, and the old convent archives have been dispersed. Given the state of the survivals, Antonella Ambrosio seeks a viable way of carrying out research on this topic: the palaeographic analysis of the few available sources using a multidisciplinary approach that combines diplomatics, archival, and historical research. This approach ensures the appropriate contextualization of the source both historically and culturally. In ‘Literacy in Neapolitan Women’s Convents: An Example of Female Handwriting in a Late Fifteenth-Century Accounts Ledger’, Ambrosio provides a case study, analysing a single piece of handwriting evidence. The source is an accounts ledger from the Dominican convent of Santi Pietro e Sebastiano compiled in the second half of the fifteenth century, from 1485 to 1496. Using an analytical approach, the author has identified the handwriting of a particular (anonymous) nun from the convent; Ambrosio studies the script the nun used and formulates hypotheses about her cultural background and how she learned to write. The palaeographic analysis is fully contextualized thanks to the reconstruction of the old convent archive, a reconstruction helped by using digital technologies now accessible online at Monasterium.net. As Ambrosio’s work demonstrates, technological advances may aid codicological work but careful palaeographic analysis is necessary to ascertain the participation of female scribes. In this case we witness the scribal development of a nun who began with a basic knowledge of writing and who went on to perform her practical task not well but adequately for the
purpose
A Targeted Mass Spectrometry Approach to Identify Peripheral Changes in Metabolic Pathways of Patients with Alzheimer’s Disease
No full text: Alzheimer's disease (AD), a neurodegenerative disorder, is the most common cause of dementia in the elderly population. Since its original description, there has been intense debate regarding the factors that trigger its pathology. It is becoming apparent that AD is more than a brain disease and harms the whole-body metabolism. We analyzed 630 polar and apolar metabolites in the blood of 20 patients with AD and 20 healthy individuals, to determine whether the composition of plasma metabolites could offer additional indicators to evaluate any alterations in the metabolic pathways related to the illness. Multivariate statistical analysis showed that there were at least 25 significantly dysregulated metabolites in patients with AD compared with the controls. Two membrane lipid components, glycerophospholipids and ceramide, were upregulated, whereas glutamic acid, other phospholipids, and sphingolipids were downregulated. The data were analyzed using metabolite set enrichment analysis and pathway analysis using the KEGG library. The results showed that at least five pathways involved in the metabolism of polar compounds were dysregulated in patients with AD. Conversely, the lipid pathways did not show significant alterations. These results support the possibility of using metabolome analysis to understand alterations in the metabolic pathways related to AD pathophysiology
How special are special sciences?
No full textThis essay deals with issues such as the unity of science, the autonomy of the special sciences, reductionism, physicalism, and the role that the concept of emergence plays in the debate about these topics. The author develops her point of view through critical examination of three significant perspectives held in contemporary epistemological discussion. Thus, according to Jerry Fodor, three theses are entailed by reductionism: the generality of physics, token physicalism, and reductionism itself (that is, the idea that every natural kind predicate of a special science is related to a natural kind predicate of physics). Fodor maintains that, in order to safeguard the autonomy of the special sciences, the reductionist thesis should be given up, as a consequence of the validity of the multiple realization thesis. Besides the generality of physics, only token physicalism is needed to guarantee both the autonomy of the special sciences and the unity of science on a physicalistic basis. However, reacting to Fodor’s thesis, Jaegwon Kim points out that adoption of token physicalism leads to consequences which are undesirable for the supporters of the autonomy of the special sciences. Moving from assumptions also shared by non-reductive physicalists, Kim argues that reductionism comes up again through “local reductions” and that, as a consequence, sciences such as psychology are devoid of any disciplinary unity. In the author’s view, Kim’s conclusions show that, in order to safeguard the autonomy of the special sciences, token-physicalism needs to be abandoned along with reductionism. In the context of present-day philosophy of science, John Dupre’s perspective is taken as an example of a position which gives up both of these conditions along with the unity of science thesis, as traditionally understood. The alternative to physicalism and to reductionism is an epistemological and ontological pluralism, according to which the different domains and levels of reality display autonomous characteristics and autonomous causal powers. But how should these latter be conceived? Does downward causation finds its place in the picture? The author’s aim in the final part of her essay is to show that Dupré’s allegiance to a liberalized form of empiricism is incompatible with an autonomous form of mental causation as well as with the most typical characteristics of the human being as a personal agent. The conclusion is drawn that in the particular case of psychology as the science of the mental, the last of Fodor’s conditions, the generality of physics, should also be rejected. Instead, a strong form of emergent property-dualism should, as a minimum, be accepted
- …
