126,459 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Valsecchi Ambrogio — Régulation des naissances. Dix années de réflexions théologiques
No full textB H. Valsecchi Ambrogio — Régulation des naissances. Dix années de réflexions théologiques. In: Population, 27ᵉ année, n°6, 1972. p. 1158
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
La ricerca della paternità deve essere ammessa. La civilistica postunitaria e le riforme del diritto di famiglia. Questioni di diritto transitorio
No full textLa norma del codice civile italiano del 1865 che prevede il divieto di indagini sulla paternità naturale costituisce una profonda innovazione, sia rispetto alla prassi giudiziaria medievale e moderna, sia rispetto alla legislazione preunitaria di primo Ottocento.
La circostanza determina un vasto dibattito dottrinale, con una forte corrente di civilisti impegnati nel chiedere una riforma del codice, ma produce anche una rilevante casistica giurisprudenziale, in relazione soprattutto alla risoluzione di questioni di diritto transitorio. Complessa in specie la situazione dei territori già appartenuti al Lombardo-Veneto e sottoposti in precedenza alla molto diversa disciplina dell’ A. B. G. B. austriac
Effect of treatment with L-deprenyl on age-dependent microanatomical changes in the rat kidney.
No full textThe influence of aging and of treatment with L-deprenyl on the structure of the kidney was investigated in 24-month-cld male Sprague Dawley rats by microanatomical techniques associated with image analysis. L-Deprenyl was administrated orally for 5 months at a dose not inhibiting monoamine oxidase (MAO) B activity (1.25/mg/kg/day) and at a dose inhibiting MAO B activity (5 mg/kg/day). In 24 month-old-rats the number and the volume of glomeruli was reduced in comparison with 12-month-old rats used as reference adult animals. Vascular changes characterised by increased thickness of the tunica media, decreased size of arterial lumen and increased wall-to-lumen ratio were also noticeable in 24-month-old rats. Moreover, an increased MAO B reactivity was noticeable within glomerular tufts and renal tubules. Treatment with the low dose of L deprenyl did not cause changes in MAO B reactivity, or in the number of glomeruli, but increased glomerular volume and reduced the wall-to-lumen ratio in medium-sized renal artery branches. The dose of 5 mg/kg/day of L-deprenyl significantly decreased MAO B reactivity within both glomerular tufts and tubules, increased the number and the volume of glomeruli and countered-age-related vascular changes. The above results suggest that treatment with L-deprenyl counters to some extent microanatomical changes occurring in the kidney of aged rats. The observation that the dose of the compound inactive on MAO B activity reduces in part age dependent renal microanatomical changes, indicates that the renal protective effect of L-deprenyl is only in part related to MAO B inhibition
Characterisation of the Thermal Damage in a Martensitic Steel Substrate Consequent to Laser Cladding Process
No full textAbstractThe paper deals with the study of the thermal damage of the substrate during the laser cladding process. The laser cladding process is known as a process which causes small thermal damage in the base material situated directly below the deposited powder. However when the laser cladding process is applied to martensitic steels, that have been previously treated in order to obtain well balanced hard and tough structures, the deposition of the heated powder as well as the interaction of the laser beam with the surface can modify the base material properties beneath the cladding layer. As a consequence uncontrolled, different and variable in hardness microstructures are produced. A 1kW fiber laser source transmitted trough a 50μm delivery fiber was employed to deposit a common Co-base powder over a martensitic stainless steel. Different process conditions were tested in order to reproduce different temperature fields in the base material. The temperature field in the substrate was measured making use of micro-thermocouples able to capture the fast heating and cooling thermal cycles during the deposition process. The microstructure analysis of the heat affected zones beneath the cladding layer together with the microhardness measurements allowed the thermal damage in terms of extension and intensity to be characterized and compared with the corresponding thermal cycles
Repeated administrations of (-)-deprenyl increase [3H]MK801 binding in rat brain and antagonize the impairment of passive avoidance conditioning induced by N-methyl-d-aspartate receptor antagonists
No full textRepeated but not single administrations of the MAO type B inhibitor (-)-deprenyl (1 μmol/kg s.c. for 21 consecutive days) antagonized the impairment of passive avoidance retention induced by the N-methyl-d-aspartate (NMDA) receptor antagonists 2-amino-5-phosphonovalerate (APV), ketamine and dizocilpine (MK801), in rats. In well-washed membranes prepared from the hippocampi of rats repeatedly treated with (-)-deprenyl, the [3H]MK801 specific binding was increased. In contrast, repeated MAO B-selective doses of pargyline or (+)-amphetamine, as well as single injections with (-)-deprenyl failed to change [3H]MK801 binding. It is suggested that the effects of repeated (-)-deprenyl administrations upon NMDA receptors and upon the impairment of acquisition of a passive avoidance task induced by NMDA antagonists could be independent of MAO inhibition. © 1994
On the predictability horizon in Impact Monitoring of Near Earth Objects
No full textThe Impact Monitoring (IM) of Near Earth Objects (NEOs) is a fundamental part of the planetary defense strategy. Current NEO IM systems (Aegis, NEODyS and Sentry) scan the Confidence Region (CR) of each observed object looking for Virtual Impactors (VIs) with a time horizon of about 100 years. This procedure is performed regardless of the uncertainty with which the orbit of the object is known, and without considering whether a scattering encounter is present in the propagation time span. In view of the likely future increase of the IM workload due to higher future NEO discovery rates, it might be more reasonable to adapt the predictability horizon of the impacts to each object, taking into account the orbit uncertainty and the close encounters experienced. In this paper we discuss the problem of estimating a reasonable predictability horizon when multiple close encounters are present and start to address the problem proposing a formal mathematical definition of scattering encounter
Powder bed irregularity and hot-spot detection in electron beam melting by means of in-situ video imaging
No full textThe electron beam melting process has been successfully applied in various sectors to produce high-value-added products. Being a hot process operating in vacuum environment with x-rays and material vaporization among by-products, in-situ sensing and monitoring presents more challenges than in laser powder bed fusion. However, an automated and robust detection of unstable process conditions represents a key capability to meet challenging qualification requirements imposed by industry. This study presents novel in-situ monitoring methods based on high spatial resolution imaging for powder bed homogeneity monitoring and high temporal resolution video-imaging for hot-spot detection, i.e., the detection of anomalous local heat accumulations
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