Atmosphere-Land Bridge between the Pacific and Tropical North Atlantic SST's through the Amazon River basin during the 2005 and 2010 droughts.

The present work uses a new approach to causal inference between complex systems called the Recurrence Measure of Conditional Dependence (RMCD) based on the recurrence plots theory, in order to study the role of the Amazon River basin (AM) as a land-atmosphere bridge between the Niño 3.0 region in the Pacific Ocean and the Tropical North Atlantic. Two anomalous droughts in the Amazon River basin were selected, one mainly attributed to the warming of the Tropical North Atlantic (2005) and the other to a warm phase of El Niño-Southern Oscillation (2010). The results of the RMCD analysis evidence the distinctive behavior in the causal information transferred between the two oceanic regions during the two extreme droughts, suggesting that the land-atmosphere bridge operating over the AM is an active hydroclimate mechanism at interannual timescales, and that the RMCD analysis may be an ancillary resort to complement early warning systems.

Constructing regional climate networks in the Amazonia during recent drought events.

Climate networks are powerful approaches to disclose tele-connections in climate systems and to predict severe climate events. Here we construct regional climate networks from precipitation data in the Amazonian region and focus on network properties under the recent drought events in 2005 and 2010. Both the networks of the entire Amazon region and the extreme networks resulted from locations severely affected by drought events suggest that network characteristics show slight difference between the two drought events. Based on network degrees of extreme drought events and that without drought conditions, we identify regions of interest that are correlated to longer expected drought period length. Moreover, we show that the spatial correlation length to the regions of interest decayed much faster in 2010 than in 2005, which is because of the dual roles played by both the Pacific and Atlantic oceans. The results suggest that hub nodes in the regional climate network of Amazonia have fewer long-range connections when more severe drought conditions appeared in 2010 than that in 2005.

Recurrence measure of conditional dependence and applications.

Identifying causal relations from observational data sets has posed great challenges in data-driven causality inference studies. One of the successful approaches to detect direct coupling in the information theory framework is transfer entropy. However, the core of entropy-based tools lies on the probability estimation of the underlying variables. Here we propose a data-driven approach for causality inference that incorporates recurrence plot features into the framework of information theory. We define it as the recurrence measure of conditional dependence (RMCD), and we present some applications. The RMCD quantifies the causal dependence between two processes based on joint recurrence patterns between the past of the possible driver and present of the potentially driven, excepting the contribution of the contemporaneous past of the driven variable. Finally, it can unveil the time scale of the influence of the sea-surface temperature of the Pacific Ocean on the precipitation in the Amazonia during recent major droughts.

The stock alloplastic temporomandibular joint implant can influence the behavior of the opposite native joint: A numerical study.

PURPOSE: The objective of the study was to investigate the effect of total stock temporomandibular implants on load mechanisms in both condyles in a specific patient. The patient presented with a disc with wear, and the introduction of a total temporomandibular prosthesis was simulated to compare the articular behavior. MATERIAL AND METHODS: Based on specific patient computed tomographic images, two finite element models were created: one model with two intact temporomandibular joints (one joint with pathology), and other model with one implanted joint. The simulations considered the five most important muscles acting in the mandible, and it was possible to evaluate the biomechanical changes in the structures (skull, mandible, and articular disc). RESULTS: The results revealed more load transfer in the opposite condyle than in the damaged one; the insertion of a total temporomandibular implant changed the load transfer to the opposite condyle. There was decreased stress in the disc by about 50% and increased strain distribution. In the mandibular condyle with implant, the screw fixation is critical, with minimum strain around -9430 µÎµ for first screw position. In the cranium, the implant changed the bone strains with a minimum principal strain observed around -2500 µÎµ in six screw positions. CONCLUSION: This study indicates that replacing the damaged joint by an implant in an ideal position will improve joint position and consequently redistribute the loads. The study findings provide strong evidence that placing an implant on one side of the mandible will affect the load distribution on that structure and particularly on the opposite side. The temporomandibular joint changes condyle movement; with an implanted condyle, the movement is almost blocked.

Role of hysteresis in stomatal aperture dynamics.

Stomata are pores responsible for gas exchange in leaves. Several experiments indicate that stomata synchronize into clusters or patches. The patches' coordination may produce oscillations in stomatal conductance. Previous studies claim to reproduce some experimental results. However, none was able to explain the variety of behavior observed in the stomatal dynamics. Recently, Ferraz and Prado suggested a realistic geometry of vein distribution. Although it reproduces the patches, no oscillation was observed and the patches remain static. Without exploring significant details, the authors stated that hysteresis in stomatal aperture could explain several experimental features. In this paper, the hysteresis hypothesis is further explored through the concept of hysteretic operators. We have shown that the hysteresis assumption is sufficient to obtain dynamical patches and oscillations in stomatal conductance. The robustness of this hypothesis is tested by using different hysteresis operators. The model analysis reveals a dependence between the period of oscillation in stomatal conductance and the water deficit between the leaf and the environment. This underlying feature of the model might inspire further experiments to test this hypothesis.

The distal end of porcine chromosome 6p is involved in the regulation of skatole levels in boars.

BACKGROUND: Boar taint is an unpleasant condition of pork, mainly due to the accumulation of androstenone and skatole in male pigs at onset of puberty. This condition is the cause of considerable economic losses in the pig industry and the most common practice to control it is to castrate male piglets. Because of the economic and animal welfare concerns there is interest in developing genetic markers that could be used in selection schemes to decrease the incidence of boar taint. The Porcine 60 K SNP Beadchip was used to genotype 891 pigs from a composite Duroc sire line, for which skatole levels in fat had been collected. RESULTS: The genome-wide association study revealed that 16 SNPs (single nucleotide polymorphisms) located on the proximal region of chromosome 6 were significantly associated with skatole levels. These SNPs are grouped in three separate clusters located in the initial 6 Mb region of chromosome 6. The differences observed between the homozygote genotypes for SNPs in the three clusters were substantial, including a difference of 102.8 ng/g skatole in melted fat between the homozygotes for the ALGA0107039 marker. Single SNPs explain up to 22% of the phenotypic variance. No obvious candidate genes could be pinpointed in the region, which may be due to the need of further annotation of the pig genome. CONCLUSIONS: This study demonstrated new SNP markers significantly associated with skatole levels in the distal region of chromosome 6p. These markers defined three independent clusters in the region, which contain a low number of protein-coding genes. The considerable differences observed between the homozygous genotypes for several SNPs may be used in future selection schemes to reduce skatole levels in pigs.

Use of Genome Sequence Information for Meat Quality Trait QTL Mining for Causal Genes and Mutations on Pig Chromosome 17.

The newly available pig genome sequence has provided new information to fine map quantitative trait loci (QTL) in order to eventually identify causal variants. With targeted genomic sequencing efforts, we were able to obtain high quality BAC sequences that cover a region on pig chromosome 17 where a number of meat quality QTL have been previously discovered. Sequences from 70 BAC clones were assembled to form an 8-Mbp contig. Subsequently, we successfully mapped five previously identified QTL, three for meat color and two for lactate related traits, to the contig. With an additional 25 genetic markers that were identified by sequence comparison, we were able to carry out further linkage disequilibrium analysis to narrow down the genomic locations of these QTL, which allowed identification of the chromosomal regions that likely contain the causative variants. This research has provided one practical approach to combine genetic and molecular information for QTL mining.

Design of a high density SNP genotyping assay in the pig using SNPs identified and characterized by next generation sequencing technology.

BACKGROUND: The dissection of complex traits of economic importance to the pig industry requires the availability of a significant number of genetic markers, such as single nucleotide polymorphisms (SNPs). This study was conducted to discover several hundreds of thousands of porcine SNPs using next generation sequencing technologies and use these SNPs, as well as others from different public sources, to design a high-density SNP genotyping assay. METHODOLOGY/PRINCIPAL FINDINGS: A total of 19 reduced representation libraries derived from four swine breeds (Duroc, Landrace, Large White, Pietrain) and a Wild Boar population and three restriction enzymes (AluI, HaeIII and MspI) were sequenced using Illumina's Genome Analyzer (GA). The SNP discovery effort resulted in the de novo identification of over 372K SNPs. More than 549K SNPs were used to design the Illumina Porcine 60K+SNP iSelect Beadchip, now commercially available as the PorcineSNP60. A total of 64,232 SNPs were included on the Beadchip. Results from genotyping the 158 individuals used for sequencing showed a high overall SNP call rate (97.5%). Of the 62,621 loci that could be reliably scored, 58,994 were polymorphic yielding a SNP conversion success rate of 94%. The average minor allele frequency (MAF) for all scorable SNPs was 0.274. CONCLUSIONS/SIGNIFICANCE: Overall, the results of this study indicate the utility of using next generation sequencing technologies to identify large numbers of reliable SNPs. In addition, the validation of the PorcineSNP60 Beadchip demonstrated that the assay is an excellent tool that will likely be used in a variety of future studies in pigs.

Gene expression profiling in hepatic tissue of newly weaned pigs fed pharmacological zinc and phytase supplemented diets.

BACKGROUND: Zinc (Zn) is an essential trace element. However, Zn bioavailability from commonly consumed plants may be reduced due to phytic acid. Zn supplementation has been used to treat diarrheal disease in children, and in the U.S. swine industry at pharmacological levels to promote growth and fecal consistency, but underlying mechanisms explaining these beneficial effects remain unknown. Moreover, adding supplemental phytase improves Zn bioavailability. Thus, we hypothesized that benefits of pharmacological Zn supplementation result from changes in gene expression that could be further affected by supplemental phytase. The goal of this study was to investigate the effects of feeding newly weaned pigs dietary Zn (150, 1,000, or 2,000 mg Zn/kg) as Zn oxide with or without phytase [500 phytase units (FTU)/kg] for 14 d on hepatic gene expression. Liver RNA from pigs fed 150, 1,000, or 2,000 mg Zn/kg, or 1,000 mg Zn/kg with phytase (n = 4 per treatment) was reverse transcribed and examined using the differential display reverse transcription polymerase chain reaction technique. Liver RNA from pigs fed 150 or 2,000 mg Zn/kg (n = 4 per treatment) was also evaluated using a 70-mer oligonucleotide microarray. RESULTS: Expressed sequence tags for 61 putatively differentially expressed transcripts were cloned and sequenced. In addition, interrogation of a 13,297 element oligonucleotide microarray revealed 650 annotated transcripts (FDR

Core strengthening exercises for low back pain.

Core strengthening concepts have gained increased popularity in low back rehabilitation. Traditional low back pain rehabilitation is based on a static spine stability model and is composed mostly of modalities, stretching and strengthening exercises. More recent theories, however, include newer concepts of dynamic spinal stability, coordination and neuromuscular control. Core strengthening exercises incorporate these new concepts. Although more research is necessary, the best available evidence suggests that a core strengthening program may be beneficial in reducing pain scores, functional disability and recurrences of acute low back pain episodes. This article reviews "core" anatomy, physiologic models of spinal stability, effects, of low back pain on spinal stability, evidence-based reasoning behind core strengthening and the basic concepts involved in designing a core strengthening program.