182 research outputs found
Effect of a multi-citrus extract-based feed additive on the survival of rainbow trout (Oncorhynchus mykiss) following challenge with Lactococcus garvieae
Growing global concerns about antibiotic resistance have generated a considerable interest in the search for alternative environmental-friendly approaches. This study was aimed to assess the antimicrobial activity of a multi-citrus extract-based feed additive (Biocitro®) against some fish pathogens, as well as evaluate its capacity to protect rainbow trout (Oncorhynchus mykiss) to lactococcosis. A broth dilution method was used to determine the minimum inhibitory concentration (MIC) of Biocitro®, and the results showed a strong antibacterial activity against Aeromonas salmonicida, Lactococcus garvieae and Yersinia ruckeri with MIC values of 2.0 µg/mL. Afterwards, rainbow trout juveniles were fed a Biocitro®-enriched diet (750 mg/kg feed) at a daily rate of 1.5% body weight for 4 weeks, then they were challenged with L. garvieae by the cohabitation method. At the end of the experimental period, fish treated with Biocitro® showed significantly (P¿<¿0.001) improved protection against L. garvieae compared to control fish. Although further studies are needed to understand how Biocitro® increases rainbow trout resistance to L. garvieae, this feed additive could be considered as a useful alternative to chemotherapeutic treatment in aquaculture
Exponential Separation of Quantum and Classical Online Space Complexity
Although quantum algorithms realizing an exponential time speed-up over the
best known classical algorithms exist, no quantum algorithm is known performing
computation using less space resources than classical algorithms. In this
paper, we study, for the first time explicitly, space-bounded quantum
algorithms for computational problems where the input is given not as a whole,
but bit by bit. We show that there exist such problems that a quantum computer
can solve using exponentially less work space than a classical computer. More
precisely, we introduce a very natural and simple model of a space-bounded
quantum online machine and prove an exponential separation of classical and
quantum online space complexity, in the bounded-error setting and for a total
language. The language we consider is inspired by a communication problem (the
set intersection function) that Buhrman, Cleve and Wigderson used to show an
almost quadratic separation of quantum and classical bounded-error
communication complexity. We prove that, in the framework of online space
complexity, the separation becomes exponential.Comment: 13 pages. v3: minor change
Prioridades de investigación y asignación de recursos en agricultura : el caso Colombiano
Reunión: Asignación de recursos para la Investigación Agrícola, 8-10 jun. 1981, Singapore, SGEn IDL-239
Redundancy, Deduction Schemes, and Minimum-Size Bases for Association Rules
Association rules are among the most widely employed data analysis methods in
the field of Data Mining. An association rule is a form of partial implication
between two sets of binary variables. In the most common approach, association
rules are parameterized by a lower bound on their confidence, which is the
empirical conditional probability of their consequent given the antecedent,
and/or by some other parameter bounds such as "support" or deviation from
independence. We study here notions of redundancy among association rules from
a fundamental perspective. We see each transaction in a dataset as an
interpretation (or model) in the propositional logic sense, and consider
existing notions of redundancy, that is, of logical entailment, among
association rules, of the form "any dataset in which this first rule holds must
obey also that second rule, therefore the second is redundant". We discuss
several existing alternative definitions of redundancy between association
rules and provide new characterizations and relationships among them. We show
that the main alternatives we discuss correspond actually to just two variants,
which differ in the treatment of full-confidence implications. For each of
these two notions of redundancy, we provide a sound and complete deduction
calculus, and we show how to construct complete bases (that is,
axiomatizations) of absolutely minimum size in terms of the number of rules. We
explore finally an approach to redundancy with respect to several association
rules, and fully characterize its simplest case of two partial premises.Comment: LMCS accepted pape
Effect of the US-Mexico border region in cardiovascular mortality: ecological time trend analysis of Mexican border and non-border municipalities from 1998 to 2012
Abstract Background An array of risk factors has been associated with cardiovascular diseases, and developing nations are becoming disproportionately affected by such diseases. Cardiovascular diseases have been reported to be highly prevalent in the Mexican population, but local mortality data is poor. The Mexican side of the US-Mexico border has a culture that is closely related to a developed nation and therefore may share the same risk factors of cardiovascular diseases. We wanted to explore if there was higher cardiovascular mortality in the border region of Mexico compared to the rest of the nation. Methods We conducted a population based cross-sectional time series analysis to estimate the effects of education, insurance and municipal size in Mexican border (n = 38) and non-border municipalities (n = 2360) and its association with cardiovascular age-adjusted mortality rates between the years 1998–2012. We used a mixed effect linear model with random effect estimation and repeated measurements to compare the main outcome variable (mortality rate), the covariates (education, insurance and population size) and the geographic delimiter (border/non-border). Results Mortality due to cardiovascular disease was consistently higher in the municipalities along the US-Mexico border, showing a difference of 78 · 5 (95% CI 58 · 7-98 · 3, p < 0 · 001) more cardiovascular deaths after adjusting for covariates. Larger municipal size and higher education levels showed a reduction in cardiovascular mortality of 12 · 6 (95% CI 11 · 4-13 · 8, p < 0 · 001) deaths and 8 · 6 (95% CI 5 · 5-11 · 8, p < 0 · 001) deaths respectively. Insurance coverage showed an increase in cardiovascular mortality of 3 · 6 (95% CI 3 · 1-4 · 0, p < 0 · 001) deaths per decile point increase. There was an increase in cardiovascular mortality of 0 · 3 (95% CI −0 · 001-0 · 6, p = 0 · 050) deaths per year increase in the non-border but a yearly reduction of 2 · 9 (95% CI 0 · 75-5.0, p = 0 · 008) deaths in the border over the time period of 1998–2012. Conclusion We observed that the Mexican side of the US-Mexico border region is disproportionately affected by cardiovascular disease mortality as compared to the non-border region of Mexico. This was not explained by education, population density, or insurance coverage. Proximity to the US culture and related diet and habits can be explanations of the increasing mortality trend
Ecological features of titica vine (Heteropsis flexuosa (Kunth) GS Bunting) in Rondônia State, Northwest Brazilian Amazon
Compressed Tree Canonization
Straight-line (linear) context-free tree (SLT) grammars have been used to
compactly represent ordered trees. It is well known that equivalence of SLT
grammars is decidable in polynomial time. Here we extend this result and show
that isomorphism of unordered trees given as SLT grammars is decidable in
polynomial time. The proof constructs a compressed version of the canonical
form of the tree represented by the input SLT grammar. The result is
generalized to unrooted trees by "re-rooting" the compressed trees in
polynomial time. We further show that bisimulation equivalence of unrooted
unordered trees represented by SLT grammars is decidable in polynomial time.
For non-linear SLT grammars which can have double-exponential compression
ratios, we prove that unordered isomorphism is PSPACE-hard and in EXPTIME. The
same complexity bounds are shown for bisimulation equivalence
La preocupación hacia las tres calidades en conservación de recursos genéticos de fríjol, forrajes tropicales y yuca para servir a la agricultura de América Latina
Probiotic supplementation in diet and vaccination of hybrid surubim (Pseudoplatystoma reticulatum♀ x P. corruscans♂)
- …