3,304 research outputs found
Information profiles for DNA pattern discovery
Finite-context modeling is a powerful tool for compressing and hence for
representing DNA sequences. We describe an algorithm to detect genomic
regularities, within a blind discovery strategy. The algorithm uses information
profiles built using suitable combinations of finite-context models. We used
the genome of the fission yeast Schizosaccharomyces pombe strain 972 h- for
illustration, unveilling locations of low information content, which are
usually associated with DNA regions of potential biological interest.Comment: Full version of DCC 2014 paper "Information profiles for DNA pattern
discovery
Paradeduction in Axiomatic Formal Systems
The concept of paradeduction is presented in order to justify that we can
overlook contradictory information taking into account only what is consistent.
Besides that, paradeduction is used to show that there is a way to transform
any logic, introduced as an axiomatic formal system, into a paraconsistent one
Preventing Atomicity Violations with Contracts
Software developers are expected to protect concurrent accesses to shared
regions of memory with some mutual exclusion primitive that ensures atomicity
properties to a sequence of program statements. This approach prevents data
races but may fail to provide all necessary correctness properties.The
composition of correlated atomic operations without further synchronization may
cause atomicity violations. Atomic violations may be avoided by grouping the
correlated atomic regions in a single larger atomic scope. Concurrent programs
are particularly prone to atomicity violations when they use services provided
by third party packages or modules, since the programmer may fail to identify
which services are correlated. In this paper we propose to use contracts for
concurrency, where the developer of a module writes a set of contract terms
that specify which methods are correlated and must be executed in the same
atomic scope. These contracts are then used to verify the correctness of the
main program with respect to the usage of the module(s). If a contract is well
defined and complete, and the main program respects it, then the program is
safe from atomicity violations with respect to that module. We also propose a
static analysis based methodology to verify contracts for concurrency that we
applied to some real-world software packages. The bug we found in Tomcat 6.0
was immediately acknowledged and corrected by its development team
Cash-on-hand in Developing Countries and the Value of Social Insurance: Evidence from Brazil
This paper first exploits a "bonus" policy providing low-income workers with cash grants in Brazil to study the effect of liquidity provision on unemployment outcomes. Based on a RD Design, I find that granting unemployed workers with a bonus equal to half of their previous monthly earnings decreases the probability of exiting unemployment within 8 weeks by around 0.65%. Second, by exploiting the UI potential duration schedule, I find that granting workers with an extra month of unemployment benefits decreases the same outcome by 1.9%. Then, theoretical results from Landais (2014) are used to combine these estimates and disentangle liquidity and moral hazard effects of UI. Based on these, I estimate the liquidity-to-moral hazard ratio in Brazil to be as large as 98%, similarly to values previously found in the US. It suggests that, contrary to common belief, providing UI in developing countries with large informal labor markets may yield substantial welfare gains
Has climate change taken prominence over biodiversity conservation?
The growing prominence of climate change has led to concerns that other important environmental issues, such as biodiversity loss, are being overshadowed. We investigate this assertion by examining trends in biodiversity and climate change coverage within the scientific and newspaper press, as well as the relative distribution of funding through the World Bank and the National Science Foundation, since the late 1980s. Our indicators substantiate some of these fears. To prevent biodiversity from becoming a declining priority, conservationists need to analyze the discourse surrounding climate change and determine how it has become the predominant environmental topic. In addition, given the common drivers of biodiversity loss and climate change, we argue that win–win solutions must be sought wherever possible. Conservationists need to be proactive and take this opportunity to use the mounting interest in climate change as a flagship to leverage more support and action to prevent further biodiversity loss
First anatomical network analysis of fore- and hindlimb musculoskeletal modularity in bonobos, common chimpanzees, and humans
Studies of morphological integration and modularity, and of anatomical complexity in human evolution typically focus on skeletal tissues. Here we provide the first network analysis of the musculoskeletal anatomy of both the fore- and hindlimbs of the two species of chimpanzee and humans. Contra long-accepted ideas, network analysis reveals that the hindlimb displays a pattern opposite to that of the forelimb: Pan big toe is typically seen as more independently mobile, but humans are actually the ones that have a separate module exclusively related to its movements. Different fore- vs hindlimb patterns are also seen for anatomical network complexity (i.e., complexity in the arrangement of bones and muscles). For instance, the human hindlimb is as complex as that of chimpanzees but the human forelimb is less complex than in Pan. Importantly, in contrast to the analysis of morphological integration using morphometric approaches, network analyses do not support the prediction that forelimb and hindlimb are more dissimilar in species with functionally divergent limbs such as bipedal humans
Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy
How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures
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