1,721,032 research outputs found
Demographic projections of the Apennine brown bear population Ursus arctos marsicanus (Mammalia: Ursidae) under alternative management scenarios
Full text linkApennine brown bears are a very small, isolated population of central Italy, consisting of about 50 individuals and under a severe risk of extinction.We performed a population viability analysis (PVA) for this population, contrasting a deterministic model and an individual-based stochastic model, using a set of demographic parameters estimated for the same population during the last decade. We also built a set of simulated management scenarios, in which we compared the effectiveness of alternative conservation measures and assessed the susceptibility of the population to catastrophic mortality events. The deterministic model produced an estimate of the asymptotic population growth rate r = 0.001, corresponding to an asymptotically stable population. The stochastic model produced an estimate of r = − 0.013 (standard deviation = 0.103), corresponding to an annual population decrease of 1.3%, a 17% extinction risk in 100 years, an average population of 27 bears for non-extinct populations, and an average time to extinction of 81 years for those gone extinct. Extinction probability increased to more alarming levels (> 0.4) when at least one catastrophic event occurred during a 100-year period. Current vital rates of the population are not compatible
with a more than negligible numerical increase, and this bear population is likely to remain small and exposed to a relatively high risk of extinction, if the average survival or reproductive rates do not increase. Management efforts aimed to increase food availability generated minimal to moderate variations in population growth rate and in the associated risk of extinction, whereas interventions meant to reduce adult female mortality were highly effective in increasing persistence probability. We propose that the general objectives of the action plan for the conservation of the Apennine brown bear for the incoming decade should explicitly contemplate quantitative demographic goals, focusing in particular on adult female and cub mortality
Active-U-Datalog: integrating active rules in a deductive database
No full textThe marriage between logic programming and databases has given rise to
the definition of deductive databases. These systems allow the
users to express data manipulations and queries in a declarative way,
and permit efficient storage and retrieval of intensional knowledge.
Another improvement in the database field has come from the use of
active rules, linking the occurrence of certain events to a reaction
(e.g., updates of some data). This kind of rules has proven to be very
useful to ensure integrity constraints and to automatize common procedures.
This paper presents an integration of active rules in U-Datalog,
which is an extension to Datalog supporting declarative
specification of updates based on a nonimmediate update semantics.
The resulting language, called Active-U-Datalog, extends
the semantics of U-Datalog in a conservative way, introducing a
PARK-like semantics for active rules activation and firing, and for
handling conflicting update requests
Quasi-Orthogonal ECG-Frank XYZ Transformation with Energy-Based Models and Clinical Text
No full textThe transformation of 12-Lead electrocardiograms to 3D vectorcardiograms, along with its reverse process, offer numerous advantages for computer visualization, signal transmission and analysis. Recent literature has shown increasing interest in this structured representation, due to its effectiveness in various cardiac evaluations and machine learning-based arrhythmia prediction. Current transformation techniques utilize fixed matrices, often retrieved through regression methods which fail to correlate with patient’s physical characteristics or ongoing diseases. In this paper, we propose the first quasi-orthogonal transformation handling multi-modal input (12-lead ECG and clinical annotations) through a conditional energy-based model. Within our novel probabilistic formulation, the model proposes multiple transformation coefficients without relying on a single fixed approximation to better highlight relationships between latent factors and structured output. The evaluation of our approach, conducted with a nested cross validation on PTB Diagnostic dataset, showcased improved reconstruction precision across various cardiac conditions compared to state-of-the-art techniques (Kors, Dower, and QSLV)
Assessing trends in wolf impact on livestock through verified claims in historical vs. recent areas of occurrence in Italy
No full textAs wolves in Europe are expanding in range, their impact on economic activities through predation on livestock is increasing. In this context, the effectiveness of damage compensation programs is being debated and requires adequate assessment. With this aim, we performed a survey of wolf depredation on livestock in Italy during the years 2010 − 2014, comparing regions of historical and more recent wolf occurrence. We collected data on livestock depredations, prevalent husbandry practices and the main features of compensation schemes. We investigated the effect of several ecological and management-related variables on the extent of wolf impact. On average, 3274 (± 195.2 SD) wolf depredation events were compensated across Italy each year, comprising 7809 (± 1278.9 SD) livestock heads, and corresponding to € 1,450,814 (± € 184,762 SD) annual compensation costs. Regions recently recolonized by wolves reported lower and decreasing levels of impact compared to those with historical wolf presence. Half of all depredations occurred in 121 municipalities (9.7% of the total), which emerged as hotspots of impact and economic cost for the system. The proportion of farms with chronically recurring damage increased by 80% in the southern Apennines, where wolves never disappeared, whereas it declined by 100% in the Alps, due to effective prevention measures implemented following wolf recolonization in the mid-1990s. Long-term human-wolf coexistence does not necessarily correspond to lower damage levels and effective conflict management, casting doubts on the effectiveness and sustainability of compensation programs, if applied without reference to a context of adaptive management
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Integrating active rules in U-Datalog
No full textThe marriage between logic programming and databases has given rise to the definition of deductive databases. These systems allow the users to express data manipulations and queries in a declarative way, and permit efficient storage and retrieval of intensional knowledge.
Another improvement in the database field has come from the use of active rules, linking the occurrence of certain events to a reaction (e.g., updates of some data). This kind of rules has proven to be very useful to ensure integrity constraints and to automatize common procedures.
This paper presents an integration of active rules in UDatalog, which is an extension to Datalog supporting declarative specification of updates based on a nonimmediate update semantics. The resulting language, called ActiveUDatalog, extends the semantics of UDatalog in a conservative way, introducing a PARKlike semantics for active rules activation and firing, and for handling conflicting update requests
- …
