614 research outputs found
Efficient Certified Resolution Proof Checking
We present a novel propositional proof tracing format that eliminates complex
processing, thus enabling efficient (formal) proof checking. The benefits of
this format are demonstrated by implementing a proof checker in C, which
outperforms a state-of-the-art checker by two orders of magnitude. We then
formalize the theory underlying propositional proof checking in Coq, and
extract a correct-by-construction proof checker for our format from the
formalization. An empirical evaluation using 280 unsatisfiable instances from
the 2015 and 2016 SAT competitions shows that this certified checker usually
performs comparably to a state-of-the-art non-certified proof checker. Using
this format, we formally verify the recent 200 TB proof of the Boolean
Pythagorean Triples conjecture
Effects of testing environments and crop density on winter wheat yield
Trabalho final de mestrado integrado em Medicina (Medicina Legal), apresentado Ă Faculdade de Medicina da Universidade de CoimbraElder abuse is not a recent phenomenon. However, only in the second half of the XX century it has been acknowledged by the scientific community and the society as a whole. This work aims at compiling some of the scientific knowledge acquired over the years, with reference to the most relevant historical aspects, evolution of concepts, definition of abuse topologies, epidemiology and theoretical models. In addition, it addresses the relevance of the shift in paradigm towards viewing violence as a matter of public health, emphasizing the roles that professionals (namely health related) may assume in the battle against elder abuse. Finally, the forensic aspects of dealing with these cases in the context of a medico legal evaluation and the Portuguese judicial system are discussed
Efficient Certified RAT Verification
Clausal proofs have become a popular approach to validate the results of SAT
solvers. However, validating clausal proofs in the most widely supported format
(DRAT) is expensive even in highly optimized implementations. We present a new
format, called LRAT, which extends the DRAT format with hints that facilitate a
simple and fast validation algorithm. Checking validity of LRAT proofs can be
implemented using trusted systems such as the languages supported by theorem
provers. We demonstrate this by implementing two certified LRAT checkers, one
in Coq and one in ACL2
Longitudinal metabolic and gut bacterial profiling of pregnant women with previous bariatric surgery
Objective Due to the global increase in obesity rates and success of bariatric surgery in weight reduction, an increasing number of women now present pregnant with a previous bariatric procedure. This study investigates the extent of bariatric-associated metabolic and gut microbial alterations during pregnancy and their impact on fetal development.
Design A parallel metabonomic (molecular phenotyping based on proton nuclear magnetic resonance spectroscopy) and gut bacterial (16S ribosomal RNA gene amplicon sequencing) profiling approach was used to determine maternal longitudinal phenotypes associated with malabsorptive/mixed (n=25) or restrictive (n=16) procedures, compared with women with similar early pregnancy body mass index but without bariatric surgery (n=70). Metabolic profiles of offspring at birth were also analysed.
Results Previous malabsorptive, but not restrictive, procedures induced significant changes in maternal metabolic pathways involving branched-chain and aromatic amino acids with decreased circulation of leucine, isoleucine and isobutyrate, increased excretion of microbial-associated metabolites of protein putrefaction (phenylacetlyglutamine, p-cresol sulfate, indoxyl sulfate and p-hydroxyphenylacetate), and a shift in the gut microbiota. The urinary concentration of phenylacetylglutamine was significantly elevated in malabsorptive patients relative to controls (p=0.001) and was also elevated in urine of neonates born from these mothers (p=0.021). Furthermore, the maternal metabolic changes induced by malabsorptive surgery were associated with reduced maternal insulin resistance and fetal/birth weight.
Conclusion Metabolism is altered in pregnant women with a previous malabsorptive bariatric surgery. These alterations may be beneficial for maternal outcomes, but the effect of elevated levels of phenolic and indolic compounds on fetal and infant health should be investigated further
Longitudinal metabolic and gut bacterial profiling of pregnant women with previous bariatric surgery
Due to the global increase in obesity rates and success of bariatric surgery in weight reduction, an increasing number of women now present pregnant with a previous bariatric procedure. This study investigates the extent of bariatric-associated metabolic and gut microbial alterations during pregnancy and their impact on fetal development. Design A parallel metabonomic (1H NMR spectroscopy) and gut bacterial (16S rRNA gene amplicon sequencing) profiling approach was used to determine maternal longitudinal phenotypes associated with malabsorptive/mixed (n=25) or restrictive (n=16) procedures, compared to women with similar early pregnancy body mass index but without bariatric surgery (n=70). Metabolic profiles of offspring at birth were also analysed. Results Previous malabsorptive, but not restrictive, procedures induced significant changes in maternal metabolic pathways involving branched-chain and aromatic amino acids with decreased circulation of leucine, isoleucine and isobutyrate, increased excretion of microbial-associated metabolites of protein putrefaction (phenylacetlyglutamine, p-cresol sulfate, indoxyl sulfate and p-hydroxyphenylacetate), and a shift in the gut microbiota. Urinary concentration of phenylacetylglutamine was significantly elevated in malabsorptive patients relative to controls (P=0.001) and was also elevated in urine of neonates born from these mothers (P=0.021). Furthermore, the maternal metabolic changes induced by malabsorptive surgery were associated with reduced maternal insulin resistance and fetal/birth weight. Conclusion Metabolism is altered in pregnant women with a previous malabsorptive bariatric surgery. These alterations may be beneficial for maternal outcomes, but the effect of elevated levels of phenolic and indolic compounds on fetal and infant health should be investigated further
Impact of maternal obesity and diabetes on long-term health of the offspring.
The initial observations of David Barker, popularly known as the “Barker hypothesis” or “developmental origins of health and disease,” show that being born with low birth weight, as a result of intrauterine growth restriction produced by maternal undernutrition, is associated with a number of chronic diseases later in life [1]. Subsequently, studies show that it is not just intrauterine growth restriction, but also exposure to any other adverse factor during fetal and/or early postnatal development that can increase susceptibility to a number of chronic diseases later in life including cardiovascular and renal disease, hypertension, type 2 diabetes, certain forms of cancer, osteoporosis, Parkinson’s disease, dementia, and polycystic ovary syndrome [2–4
Solving the Uncapacitated Single Allocation p-Hub Median Problem on GPU
A parallel genetic algorithm (GA) implemented on GPU clusters is proposed to
solve the Uncapacitated Single Allocation p-Hub Median problem. The GA uses
binary and integer encoding and genetic operators adapted to this problem. Our
GA is improved by generated initial solution with hubs located at middle nodes.
The obtained experimental results are compared with the best known solutions on
all benchmarks on instances up to 1000 nodes. Furthermore, we solve our own
randomly generated instances up to 6000 nodes. Our approach outperforms most
well-known heuristics in terms of solution quality and time execution and it
allows hitherto unsolved problems to be solved
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Impact of maternal bariatric surgery on offspring perinatal cardiac function: A prospective study
Objective
To assess perinatal cardiac function in offspring of women with previous bariatric surgery and examine its association with maternal glucose control.
Design
Prospective study.
Setting
Maternity unit, UK.
Population
Fifty-four fetuses/neonates; 29 of post-bariatric surgery women and 25 of women without surgery.
Methods
Prospective, longitudinal observational study of pregnant women with and without previous bariatric surgery, matched for early pregnancy body mass index. Cardiac function of all offspring was assessed by two-dimensional conventional, spectral tissue Doppler and speckle-tracking echocardiography at 35–37 weeks of gestation and at 5–7 weeks of age. Maternal glycated haemoglobin (HbA1c) was measured at 27–30 weeks of gestation. Maternal demographics and fetal/infant cardiac function indices were compared between the groups. Correlation coefficient (r) is reported.
Main outcome measures
Fetal/infant cardiac function indices.
Results
Compared with no-bariatric neonates, offspring of post-bariatric women were smaller at birth (birthweight centiles: 64.96 ± 36.41 versus 40.17 ± 27.99; p = 0.007). There were no significant differences in fetal/infant cardiac function indices and perinatal cardiac changes, between groups. There was a positive correlation between maternal HbA1c and fetal left ventricular (LV) longitudinal strain (r = 0.33) and LV longitudinal strain rate (r = 0.29), suggesting an inverse relation between HbA1c and fetal LV systolic function, but this was mainly seen in offspring of women with no previous bariatric surgery (r = 0.56 and r = 0.50, respectively).
Conclusions
Maternal bariatric surgery does not appear to inadvertently affect the offspring cardiac performance. We found an inverse correlation between maternal HbA1c levels and fetal LV systolic function but this was mainly seen in the no-bariatric pregnancies
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