Reduction in Salt Stress Due to the Action of Halophilic Bacteria That Promote Plant Growth in Solanum lycopersicum.

Soil salinity is one of the most important factors reducing agricultural productivity worldwide. Halophilic plant growth-promoting bacteria (H-PGPB) represent an alternative method of alleviating saline stress in crops of agricultural interest. In this study, the following halophilic bacteria were evaluated: Bacillus sp. SVHM1.1, Halomonas sp. SVCN6, Halomonas sp. SVHM8, and a consortium. They were grown under greenhouse conditions in Solanum lycopersicum at different salinity concentrations in irrigation water (0, 20, 60, and 100 mM NaCl) to determine the effects on germination, fruit quality, yield, and concentration of osmoprotectors in plant tissue. Our results demonstrate the influence of halophilic bacteria with the capacity to promote plant growth on the germination and development of Solanum lycopersicum at higher salinity levels. The germination percentage was improved at the highest concentration by the inoculated treatments (from 37 to 47%), as were the length of the radicle (30% at 20 mM) and plumule of the germinated seed, this bacterium also increased the weight of the plumule (97% at 100 mM). They also improved the yield. The dry weight of the plant, in addition to having an influence on the quality of the fruit and the concentration of osmoprotectors (Bacillus sp. SVHM 1.1) had the greatest effect on fruit yield (1.5 kg/plant at 20 mM), by the otherhand, Halomonas sp. SVHM8 provided the best fruit quality characteristics at 100 mM. According to the above results, the efficiency of halophilic PGPB in the attenuation of salt stress in Solanum lycopersicum has been proven.

Computational simulation-based comparative analysis of standard 3D printing and conical nozzles for pneumatic and piston-driven bioprinting.

Bioprinting is an application of additive manufacturing that can deliver promising results in regenerative medicine. Hydrogels, as the most used materials in bioprinting, are experimentally analyzed to assure printability and suitability for cell culture. Besides hydrogel features, the inner geometry of the microextrusion head might have an equal impact not only on printability but also on cellular viability. In this regard, standard 3D printing nozzles have been widely studied to reduce inner pressure and get faster printings using highly viscous melted polymers. Computational fluid dynamics is a useful tool capable of simulating and predicting the hydrogel behavior when the extruder inner geometry is modified. Hence, the objective of this work is to comparatively study the performance of a standard 3D printing and conical nozzles in a microextrusion bioprinting process through computational simulation. Three bioprinting parameters, namely pressure, velocity, and shear stress, were calculated using the level-set method, considering a 22G conical tip and a 0.4 mm nozzle. Additionally, two microextrusion models, pneumatic and piston-driven, were simulated using dispensing pressure (15 kPa) and volumetric flow (10 mm3/s) as input, respectively. The results showed that the standard nozzle is suitable for bioprinting procedures. Specifically, the inner geometry of the nozzle increases the flow rate, while reducing the dispensing pressure and maintaining similar shear stress compared to the conical tip commonly used in bioprinting.

Improving Cell Viability and Velocity in µ-Extrusion Bioprinting with a Novel Pre-Incubator Bioprinter and a Standard FDM 3D Printing Nozzle.

Bioprinting is a promising emerging technology. It has been widely studied by the scientific community for the possibility to create transplantable artificial tissues, with minimal risk to the patient. Although the biomaterials and cells to be used are being carefully studied, there is still a long way to go before a bioprinter can easily and quickly produce printings without harmful effects on the cells. In this sense, we have developed a new µ-extrusion bioprinter formed by an Atom Proton 3D printer, an atmospheric enclosure and a new extrusion-head capable to increment usual printing velocity. Hence, this work has two main objectives. First, to experimentally study the accuracy and precision. Secondly, to study the influence of flow rates on cellular viability using this novel µ-extrusion bioprinter in combination with a standard FDM 3D printing nozzle. Our results show an X, Y and Z axis movement accuracy under 17 µm with a precision around 12 µm while the extruder values are under 5 and 7 µm, respectively. Additionally, the cell viability obtained from different volumetric flow tests varies from 70 to 90%. So, the proposed bioprinter and nozzle can control the atmospheric conditions and increase the volumetric flow speeding up the bioprinting process without compromising the cell viability.

Temperature and Humidity PID Controller for a Bioprinter Atmospheric Enclosure System.

Bioprinting is a complex process, highly dependent on bioink properties (materials and cells) and environmental conditions (mainly temperature, humidity and CO2 concentration) during the bioprinting process. To guarantee proper cellular viability and an accurate geometry, it is mandatory to control all these factors. Despite internal factors, such as printing pressures, temperatures or speeds, being well-controlled in actual bioprinters, there is a lack in the controlling of external parameters, such as room temperature or humidity. In this sense, the objective of this work is to control the temperature and humidity of a new, atmospheric enclosure system for bioprinting. The control has been carried out with a decoupled proportional integral derivative (PID) controller that was designed, simulated and experimentally tested in order to ensure the proper operation of all its components. Finally, the PID controller can stabilize the atmospheric enclosure system temperature in 311 s and the humidity in 65 s, with an average error of 1.89% and 1.30%, respectively. In this sense, the proposed atmospheric enclosure system can reach and maintain the proper temperature and humidity values during post-printing and provide a pre-incubation environment that promotes stability, integrity and cell viability of the 3D bioprinted structures.

Perspectives on Low Temperature Tolerance and Vernalization Sensitivity in Barley: Prospects for Facultative Growth Habit.

One option to achieving greater resiliency for barley production in the face of climate change is to explore the potential of winter and facultative growth habits: for both types, low temperature tolerance (LTT) and vernalization sensitivity are key traits. Sensitivity to short-day photoperiod is a desirable attribute for facultative types. In order to broaden our understanding of the genetics of these phenotypes, we mapped quantitative trait loci (QTLs) and identified candidate genes using a genome-wide association studies (GWAS) panel composed of 882 barley accessions that was genotyped with the Illumina 9K single-nucleotide polymorphism (SNP) chip. Fifteen loci including 5 known and 10 novel QTL/genes were identified for LTT-assessed as winter survival in 10 field tests and mapped using a GWAS meta-analysis. FR-H1, FR-H2, and FR-H3 were major drivers of LTT, and candidate genes were identified for FR-H3. The principal determinants of vernalization sensitivity were VRN-H1, VRN-H2, and PPD-H1. VRN-H2 deletions conferred insensitive or intermediate sensitivity to vernalization. A subset of accessions with maximum LTT were identified as a resource for allele mining and further characterization. Facultative types comprised a small portion of the GWAS panel but may be useful for developing germplasm with this growth habit.

Interrelación entre enfisema y disfunción diastólica ventricular izquierda: nuestra experiencia en el Hospital Privado Centro Médico de Córdoba / Interrelation between emphysema and diastolic dysfunction left ventricular: our experience in the Hospital Private Medical Center of Córdoba

Introducción: Las consecuencias hemodinámicas de la hiperinflación y el enfisema se producen por compresión cardíaca debido a elevadas presiones intratorácicas, lo que produciría disfunción diastólica ventricular izquierda subclínica. Nuestro objetivo es correlacionar el porcentaje de enfisema con parámetros de función pulmonar y con el tamaño de las cámaras cardíacas, función sistólica ventricular global y función diastólica ventricular izquierda, en la enfermedad pulmonar obstructiva crónica. Materiales y Métodos: participaron pacientes con enfermedad pulmonar obstructiva crónica moderada y severa asistidos en un Servicio de Neumonología del Hospital Privado Centro Médico de Córdoba, desde el 01 de enero al 31 de octubre de 2014. Se cuantificó el volumen y porcentaje de enfisema por tomografía computada de alta resolución, se realizaron espirometría, prueba de marcha de seis minutos, determinación de volúmenes pulmonares y ecocardiograma Doppler color. Resultados: Se encontró correlación negativa y significativa del porcentaje de enfisema con el porcentaje del valor teórico del VEF1 postbroncodilatador (p = 0.005) y el cociente VEF1/CVF postbroncodilatador (p = 0.004) y; además, entre el cociente VEF1/CVF postbroncodilatador y el volumen del enfisema en cm3 (p = 0.000). De un subgrupo de 20 pacientes. Siete pacientes (35%) presentaron diagnóstico de disfunción diastólica ventricular izquierda de grado I. Se encontraron correlaciones negativas pero no significativas entre el porcentaje de enfisema con función sistólica ventricular global y el tamaño de las cámaras cardíacas. Conclusiones: Se destaca la utilidad del ecocardiograma para reducir el sub diagnóstico de disfunción diastólica ventricular izquierda. Se destaca la importancia que tendrían la hiperinflación y el enfisema en el deterioro del patrón de llenado diastólico ventricular izquierdo y en la reducción del tamaño de las cámaras cardíacas con disminución en la tolerancia al ejercicio.

Interrelationship between Emphysema and Left Ventricular Diastolic Dysfunction: our experience in the Hospital Privado Centro Médico de Córdoba

Introduction: The hemodynamic consequences of hyperinflation and emphysema are produced by cardiac compression due to high intrathoracic pressures, which could produce subclinical left ventricular diastolic dysfunction. Our purpose is to correlate the percentage of emphysema with lung function parameters and cardiac chamber sizes, the global ventricular systolic function and the left ventricular diastolic function, in cases of chronic obstructive pulmonary disease. Materials and Methods: The participants were patients with moderate and severe chronic obstructive pulmonary disease treated in the Pulmonology Service of the Hospital Privado Centro Médico de Córdoba from January 1st to October 13th, 2014. We quantified the volume and percentage of emphysema by high resolution computed tomography and carried out a spirometry, a Six Minute Walk Test, measurement of pulmonary volumes and color Doppler echocardiography. Results: We found a significant negative correlation between the percentage of emphysema and the percentage of the post-bronchodilator FEV1 theoretical value (p = 0.005) and the post-bronchodilator FEV1/FVC (Forced Expiratory Volume in First Second/Forced Vital Capacity) quotient (p = 0.004), and, also, between the post-bronchodilator FEV1/FVC quotient and the emphysema volume in cm3 (p = 0.000). Out of a sub-group of 20 patients, seven patients (35%) were diagnosed with grade I left ventricular diastolic dysfunction. We found negative, but not significant correlations between the percentage of emphysema and global ventricular systolic function and cardiac chamber sizes. Conclusions: We should emphasize the usefulness of the echocardiography in reducing sub-diagnoses of left ventricular diastolic dysfunction. We should also stress on the importance hyperinflation and emphysema would have in the impairment of the left ventricular diastolic filling pattern and in the decrease in cardiac chamber sizes, with a decrease in exercise tolerance.

Computational simulation of aqueous humour dynamics in the presence of a posterior-chamber versus iris-fixed phakic intraocular lens.

PURPOSE: To compare aqueous humour (AH) dynamics in the presence of a precrystalline (Implantable Collamer Lens®; ICL) or iris-fixed (Artiflex®) phakic intraocular lens (PIOL). METHODS: By computational fluid dynamics simulation, AH flow was modelled through a peripheral iridotomy (PI) or central lens hole (both 360 µm) in the presence of an Artiflex or ICL lens, respectively. The impacts of AH flow were then determined in terms of wall shear stress (WSS) produced on the endothelium or crystalline lens. Effects were also modelled for different scenarios of pupil diameter (PD 3.5 or 5.5 mm), ICL vault (100, 350, 800 µm) and number of Artiflex iridotomies (1 or 2) and location (12 or 6 o'clock). RESULTS: For a PD of 3.5 mm, AH volumes flowing from the posterior to the anterior chamber were 37.6% of total flow through the lens hole (ICL) and 84.2% through PI (Artiflex). For an enlarged PD (5.5 mm), corresponding values were 10.3% and 81.9% respectively, so PI constitutes a very efficient way of evacuating AH. Central endothelial WSS in Pa was lower for the large vault ICL and the Artiflex (1-03 and 1.1-03 respectively) compared to the PIOL-free eye (1.6-03). Crystalline lens WSS was highest for the lowest vault ICL (1-04). CONCLUSIONS: AH flow varied according to the presence of a precrystalline or iris-fixed intraocular lens. Endothelial WSS was lower for an implanted ICL with large vault and Artiflex than in the PIOL-free eye, while highest crystalline WSS was recorded for the lowest vault ICL.

A new adaptive time step method for unsteady flow simulations in a human lung.

The innovation presented is a method for adaptive time-stepping that allows clustering of time steps in portions of the cycle for which flow variables are rapidly changing, based on the concept of using a uniform step in a relevant dependent variable rather than a uniform step in the independent variable time. A user-defined function was developed to adapt the magnitude of the time step (adaptive time step) to a defined rate of change in inlet velocity. Quantitative comparison indicates that the new adaptive time stepping method significantly improves accuracy for simulations using an equivalent number of time steps per cycle.

The Relationships between Development and Low Temperature Tolerance in Barley Near Isogenic Lines Differing for Flowering Behavior.

Flowering time, vernalization requirement, photoperiod sensitivity and low temperature tolerance are key traits in the Triticeae. We characterized a set of isogenic genetic stocks-representing single and pairwise substitutions of spring alleles at the VRN-H1, VRN-H2 and VRN-H3 loci in a winter barley background-at the structural, functional and phenotypic levels. High density mapping with reference to the barley genome sequence confirmed that in all cases target VRN alleles were present in the near isogenic lines (NILs) and allowed estimates of introgression size (at the genetic and physical levels) and gene content. Expression data corroborated the structural and phenotypic results. The latter confirmed that substitution of a spring allele at any of the VRN loci is sufficient to eliminate vernalization requirement. There was no significant change in low temperature tolerance with substitution of a spring allele at VRN-H2, but there were significant losses in cold tolerance with substitutions at VRN-H1 and VRN-H3. Reductions in cold tolerance are ascribed to an accelerated transition from the vegetative to reproductive state. The set of NILs will be a rich resource for understanding the genetics of vernalization, low temperature tolerance and other traits encoded/regulated by genes within the introgressed intervals.

Quantitative Trait Loci Associated with the Tocochromanol (Vitamin E) Pathway in Barley.

The Genome-Wide Association Studies approach was used to detect Quantitative Trait Loci associated with tocochromanol concentrations using a panel of 1,466 barley accessions. All major tocochromanol types- α-, ß-, δ-, γ-tocopherol and tocotrienol- were assayed. We found 13 single nucleotide polymorphisms associated with the concentration of one or more of these tocochromanol forms in barley, seven of which were within 2 cM of sequences homologous to cloned genes associated with tocochromanol production in barley and/or other plants. These associations confirmed a prior report based on bi-parental QTL mapping. This knowledge will aid future efforts to better understand the role of tocochromanols in barley, with specific reference to abiotic stress resistance. It will also be useful in developing barley varieties with higher tocochromanol concentrations, although at current recommended daily consumption amounts, barley would not be an effective sole source of vitamin E. However, it could be an important contributor in the context of whole grains in a balanced diet.

The USDA barley core collection: genetic diversity, population structure, and potential for genome-wide association studies.

New sources of genetic diversity must be incorporated into plant breeding programs if they are to continue increasing grain yield and quality, and tolerance to abiotic and biotic stresses. Germplasm collections provide a source of genetic and phenotypic diversity, but characterization of these resources is required to increase their utility for breeding programs. We used a barley SNP iSelect platform with 7,842 SNPs to genotype 2,417 barley accessions sampled from the USDA National Small Grains Collection of 33,176 accessions. Most of the accessions in this core collection are categorized as landraces or cultivars/breeding lines and were obtained from more than 100 countries. Both STRUCTURE and principal component analysis identified five major subpopulations within the core collection, mainly differentiated by geographical origin and spike row number (an inflorescence architecture trait). Different patterns of linkage disequilibrium (LD) were found across the barley genome and many regions of high LD contained traits involved in domestication and breeding selection. The genotype data were used to define 'mini-core' sets of accessions capturing the majority of the allelic diversity present in the core collection. These 'mini-core' sets can be used for evaluating traits that are difficult or expensive to score. Genome-wide association studies (GWAS) of 'hull cover', 'spike row number', and 'heading date' demonstrate the utility of the core collection for locating genetic factors determining important phenotypes. The GWAS results were referenced to a new barley consensus map containing 5,665 SNPs. Our results demonstrate that GWAS and high-density SNP genotyping are effective tools for plant breeders interested in accessing genetic diversity in large germplasm collections.

Barley genetic variation: implications for crop improvement.

Genetic variation is crucial for successful barley improvement. Genomic technologies are improving dramatically and are providing access to the genetic diversity within this important crop species. Diverse collections of barley germplasm are being assembled and mined via genome-wide association studies and the identified variation can be linked to the barley sequence assembly. Introgression of favorable alleles via marker-assisted selection is now faster and more efficient due to the availability of single nucleotide polymorphism platforms. High-throughput genotyping is also making genomic selection an essential tool in modern barley breeding. Contemporary plant breeders now benefit from publicly available user-friendly databases providing genotypic and phenotypic information on large numbers of barley accessions. These resources facilitate access to allelic variation. In this review we explore how the most recent genomics and molecular breeding advances are changing breeding practices. The Coordinated Agricultural Projects (CAPs), Barley CAP and Triticeae CAP coupled with international collaborations, are discussed in detail as examples of a collaborative approach to exploit diverse germplasm resources for barley improvement.

Hv-CBF2A overexpression in barley accelerates COR gene transcript accumulation and acquisition of freezing tolerance during cold acclimation.

C-Repeat Binding Factors (CBFs) are DNA-binding transcriptional activators of gene pathways imparting freezing tolerance. Poaceae contain three CBF subfamilies, two of which, HvCBF3/CBFIII and HvCBF4/CBFIV, are unique to this taxon. To gain mechanistic insight into HvCBF4/CBFIV CBFs we overexpressed Hv-CBF2A in spring barley (Hordeum vulgare) cultivar 'Golden Promise'. The Hv-CBF2A overexpressing lines exhibited stunted growth, poor yield, and greater freezing tolerance compared to non-transformed 'Golden Promise'. Differences in freezing tolerance were apparent only upon cold acclimation. During cold acclimation freezing tolerance of the Hv-CBF2A overexpressing lines increased more rapidly than that of 'Golden Promise' and paralleled the freezing tolerance of the winter hardy barley 'Dicktoo'. Transcript levels of candidate CBF target genes, COR14B and DHN5 were increased in the overexpressor lines at warm temperatures, and at cold temperatures they accumulated to much higher levels in the Hv-CBF2A overexpressors than in 'Golden Promise'. Hv-CBF2A overexpression also increased transcript levels of other CBF genes at FROST RESISTANCE-H2-H2 (FR-H2) possessing CRT/DRE sites in their upstream regions, the most notable of which was CBF12. CBF12 transcript levels exhibited a relatively constant incremental increase above levels in 'Golden Promise' both at warm and cold. These data indicate that Hv-CBF2A activates target genes at warm temperatures and that transcript accumulation for some of these targets is greatly enhanced by cold temperatures.

FR-H3: a new QTL to assist in the development of fall-sown barley with superior low temperature tolerance.

Fall-sown barley will be increasingly important in the era of climate change due to higher yield potential and efficient use of water resources. Resistance/tolerance to abiotic stresses will be critical, and foremost among the abiotic stresses is low temperature. Simultaneous gene discovery and breeding will accelerate the development of agronomically relevant fall-sown barley germplasm with resistance to low temperature. We developed two doubled haploid mapping populations using two lines from the University of Nebraska (NE) and one line from Oregon State University (OR): NB3437f/OR71 (facultative × facultative) and NB713/OR71 (winter × facultative). Both were genotyped with a custom 384 oligonucleotide pool assay (OPA). QTL analyses were performed for low temperature tolerance (LTT) and vernalization sensitivity (VS). The role of VRN-H2 in VS was confirmed and a novel alternative winter allele at VRN-H3 was discovered in the Nebraska germplasm. FR-H2 was identified as a probable determinant of LTT and a new QTL, FR-H3, was discovered on chromosome 1H that accounted for up to 48 % of the phenotypic variation in field survival at St. Paul, MN, USA. The discovery of FR-H3 is a significant advancement in barley LTT genetics and will assist in developing the next generation of fall-sown varieties.

Utility of bispectral index monitoring during intravenous sedation in the dental office.

PURPOSE: This research sought to compare two different systems to monitor sedated patients undergoing implant surgery in the dental office: the bispectral index (BIS) and the Ramsay scale. This information was used to establish an optimal BIS range for surgery in these patients and to calculate differences in drug consumption in both groups. MATERIALS AND METHODS: Consecutive patients undergoing implant surgery were studied and randomly assigned to two groups. Patients were sedated using intravenous propofol, fentanyl, and midazolam. The sedation level in group A was measured using the Ramsay scale. In group B, the Ramsay scale and the BIS were used together. Heart rate, blood pressure, and peripheral oxygen saturation were monitored in all patients. The levels of anxiety, satisfaction, and drug consumption were compared between groups. RESULTS: Forty-three patients were included; 20 were placed in group A and 23 were included in group B. There were no differences in the hemodynamic and respiratory parameters monitored or in anxiety or satisfaction levels in both groups. In group B patients, the BIS values stabilized around 85; the Ramsay scale stabilized around 3 in both groups and remained at these levels until the end of the procedure. Drug consumption was significantly lower in the BIS group. CONCLUSION: The optimal BIS value during intravenous sedation in sedated ambulatory patients in dental surgery should be within the 80 to 85 range. BIS monitoring allows for reduced consumption of propofol, fentanyl, and midazolam.

Construction and application for QTL analysis of a Restriction Site Associated DNA (RAD) linkage map in barley.

BACKGROUND: Linkage maps are an integral resource for dissection of complex genetic traits in plant and animal species. Canonical map construction follows a well-established workflow: an initial discovery phase where genetic markers are mined from a small pool of individuals, followed by genotyping of selected mapping populations using sets of marker panels. A newly developed sequence-based marker technology, Restriction site Associated DNA (RAD), enables synchronous single nucleotide polymorphism (SNP) marker discovery and genotyping using massively parallel sequencing. The objective of this research was to assess the utility of RAD markers for linkage map construction, employing barley as a model system. Using the published high density EST-based SNP map in the Oregon Wolfe Barley (OWB) mapping population as a reference, we created a RAD map using a limited set of prior markers to establish linakge group identity, integrated the RAD and prior data, and used both maps for detection of quantitative trait loci (QTL). RESULTS: Using the RAD protocol in tandem with the Illumina sequence by synthesis platform, a total of 530 SNP markers were identified from initial scans of the OWB parental inbred lines--the "dominant" and "recessive" marker stocks--and scored in a 93 member doubled haploid (DH) mapping population. RAD sequence data from the structured population was converted into allele genotypes from which a genetic map was constructed. The assembled RAD-only map consists of 445 markers with an average interval length of 5 cM, while an integrated map includes 463 RAD loci and 2383 prior markers. Sequenced RAD markers are distributed across all seven chromosomes, with polymorphic loci emanating from both coding and noncoding regions in the Hordeum genome. Total map lengths are comparable and the order of common markers is identical in both maps. The same large-effect QTL for reproductive fitness traits were detected with both maps and the majority of these QTL were coincident with a dwarfing gene (ZEO) and the VRS1 gene, which determines the two-row and six-row germplasm groups of barley. CONCLUSIONS: We demonstrate how sequenced RAD markers can be leveraged to produce high quality linkage maps for detection of single gene loci and QTLs. By combining SNP discovery and genotyping into parallel sequencing events, RAD markers should be a useful molecular breeding tool for a range of crop species. Expected improvements in cost and throughput of second and third-generation sequencing technologies will enable more powerful applications of the sequenced RAD marker system, including improvements in de novo genome assembly, development of ultra-high density genetic maps and association mapping.

Genome-wide SNPs and re-sequencing of growth habit and inflorescence genes in barley: implications for association mapping in germplasm arrays varying in size and structure.

BACKGROUND: Considerations in applying association mapping (AM) to plant breeding are population structure and size: not accounting for structure and/or using small populations can lead to elevated false-positive rates. The principal determinants of population structure in cultivated barley are growth habit and inflorescence type. Both are under complex genetic control: growth habit is controlled by the epistatic interactions of several genes. For inflorescence type, multiple loss-of-function alleles in one gene lead to the same phenotype. We used these two traits as models for assessing the effectiveness of AM. This research was initiated using the CAP Core germplasm array (n = 102) assembled at the start of the Barley Coordinated Agricultural Project (CAP). This array was genotyped with 4,608 SNPs and we re-sequenced genes involved in morphology, growth and development. Larger arrays of breeding germplasm were subsequently genotyped and phenotyped under the auspices of the CAP project. This provided sets of 247 accessions phenotyped for growth habit and 2,473 accessions phenotyped for inflorescence type. Each of the larger populations was genotyped with 3,072 SNPs derived from the original set of 4,608. RESULTS: Significant associations with SNPs located in the vicinity of the loci involved in growth habit and inflorescence type were found in the CAP Core. Differentiation of true and spurious associations was not possible without a priori knowledge of the candidate genes, based on re-sequencing. The re-sequencing data were used to define allele types of the determinant genes based on functional polymorphisms. In a second round of association mapping, these synthetic markers based on allele types gave the most significant associations. When the synthetic markers were used as anchor points for analysis of interactions, we detected other known-function genes and candidate loci involved in the control of growth habit and inflorescence type. We then conducted association analyses--with SNP data only--in the larger germplasm arrays. For both vernalization sensitivity and inflorescence type, the most significant associations in the larger data sets were found with SNPs coincident with the synthetic markers used in the CAP Core and with SNPs detected via interaction analysis in the CAP Core. CONCLUSIONS: Small and highly structured collections of germplasm, such as the CAP Core, are cost-effectively phenotyped and genotyped with high-throughput markers. They are also useful for characterizing allelic diversity at loci in germplasm of interest. Our results suggest that discovery-oriented exercises in AM in such small arrays may generate a large number of false-positives. However, if haplotypes in candidate genes are available, they may be used as anchors in an analysis of interactions to identify other candidate regions harboring genes determining target traits. Using larger germplasm arrays, genome regions where the principal genes determining vernalization sensitivity and row type are located were identified.

[The Grice technique for tarsal coalition]. / Coalición tarsal, técnica de Grice.

OBJECTIVE: Show that the surgical release of the coalition area and the Grice subtalar arthrodesis are useful for the treatment of tarsal coalition, and describe the surgical techniques used. MATERIAL AND METHODS: This is a prospective, longitudinal, non-randomized clinical trial conducted from January 2001 to December 2007. Patients of both genders were selected, ages 10-15 years of age, with a diagnosis of tarsal coalition without any other type of orthopedic or neurologic comorbid condition. The Harris classification of tarsal coalition was used. AP, lateral and oblique X-rays of both feet were ordered, as well as a CAT scan; the Costa-Bertani angles were measured. Central trend and scatter measurements were performed for the statistical analysis, as well as the comparison of means Z test, the relative risk (RR) and the linear correlation. RESULTS: Twenty-six patients, 20 males and 6 females, were included in the study; 12 of them had fibrous talocalcaneal coalitions, 12 had bone coalitions and 2 had calcaneonavicular coalitions. COMPLICATIONS: one reflex sympathetic dystrophy, 4 superficial infections, 4 graft resorptions, and 4 patients with persistent pain. In the Z test for the Costa-Bertani angles the p value was 0.0020. The RR for obesity was 4.5, the linear correlation coefficient r for valgus hindfoot and pain was 78. DISCUSSION: The clinical results indicate an improvement in pain and gait. Overweight was found to be a risk factor for persistent pain.

[Radiological evaluation of the flexibles pes planus treated with conic endorthesis]. / Valoración radiológica del pie plano flexible tratado con endoprótesis cónica.

OBJECTIVE: To determine the correction of flexible pes planus by means of the placement of a conic endorthesis in the subtalar joint. Outcomes were based on measures of the Moreau-Costa-Bartani and talar-navicular angles. MATERIAL AND METHODS: A series of 22 patients of both genders (7 to 13 years-old), were operated on both feet. The subtalar joint was stabilized by placement of a conic endorthesis. All of them were diagnosed as flexible pes planus, and 44 feet were operated on. All cases had previous conservative treatment without improvement. In these patients the Moreau-Costa-Bartani and talar-navicular angles were measured on lateral and dorsoplantar projections respectively, and compared pre and post-operatively. RESULTS: Significant correction of the analyzed angles was achieved. We obtained less than 130 p in the "A" angle and less than 150 p in the "B" in the lateral projection, and less than 80 p in the dorsoplantar projection. CONCLUSION: Normal Moreau-Costa-Bartani and talarnavicular angles were achieved by means of the subtalar placement of a conic endortheses, and normal ranges were obtained in the simple X-rays measures.