Prestress behaviour and ductility requirements in structures: solutions from a unified algebraic approach.

This paper presents an algebraic approach that unifies both the elastic and limit theories of static structural analysis. This approach reveals several previously unpublished improvements, which are based on several dualities in the mathematical description. Firstly, we show a novel duality between the solutions to two different problems: the elastic solution to the internal forces of an externally loaded structure, and the nodal displacements induced by prestressing in one or several elements of the same structure. This duality is proven and discussed. The application of this solution to the limit state analysis is very productive, and includes the determination of the ductility requirements necessary to achieve full plastic behaviour, and the assessment of the prestress needed to limit or eliminate such requirements. The unified framework also allows to obtain the elasto-plastic deformed state at the beginning of the plastic structural collapse. We have also detailed the theoretical duality between two classes of structures-hyperstatic and hypostatic-which was derived from the linear algebra principles that define these solutions. Finally, we studied and exposed the dimensionality reduction of structural problems given by the singular value decomposition and the eigenvalues problem. An illustrative example that clearly illustrates all these points is provided.

Importance of crop phenological stages for the efficient use of PGPR inoculants.

During the last decades, the incorporation of beneficial microorganisms in agriculture crop management has become a common practice. Seed coating of these microorganisms still faces technical issues, which limit its implementation in conventional agriculture. An adaption to widely established agricultural practices, e.g. fertigation, could help to overcome these issues. Here, using Bacillus velezensis strain BBC047, we show the influence of the crop phenological stages on the efficiency and success of microbial inoculation under agricultural conditions. In the commercial nursery, strain BBC047 improved growth in a variety of horticulture crops like basil, cabbage, tomato and bell pepper, the latter with the strongest effects in strengthening and accelerating the seedling growth (root and aerial biomass). For a field trial under productive conditions, different application strategies were compared, using bell pepper (Capsicum annuum L.) as crop under fertigation: conventional management (T1), application to the seedling (only nursery, T2), only post-transplant application (field, T3) and a combination of both (T4). In T2 and T4, the post-transplantation survival rate (p < 0.05) improved and the productivity of the plants increased (> 100%). Applications of BBC047 post-transplantation (T3) caused a lower increase in productivity (25%). Fruits from all three application strategies contained significantly more Vitamin C. We conclude that in conventional agriculture, the applications of PGPR inoculants to early crop phenological stages like nurseries are a viable alternative for the efficient use of PGPR inoculants. In comparison, a late introduction of a PGPR reduces its beneficial effect on crop productivity. We highlight that an appropriate timing in the use of PGPR inoculants is crucial for product development and success in sustainable agriculture.

Physiological stabilization, community characterization, and nitrogen degradation dynamics in an anammox consortium from estuarine sediments.

Anammox is a cost-effective and sustainable process for nitrogen removal; however, the production of a physiologically stable inoculum is a critical point in the start-up process. In this work, estuarine sediments were used as incubation seeds to obtain cultures with stable anammox activity. Assays were performed in batch cultures fed with stoichiometric amounts of ammonium and nitrite, analyzing physiological response variables and the microbial community. Estuarine sediments showed a stable anammox process after 90 days, consuming ammonium and nitrite simultaneously with concomitant generation of N2 and nitrate in stoichiometric amounts. In kinetic assays, substrates were fully consumed after 210 hr, exhibiting N2 and nitrate yields of 0.85 and 0.10, respectively. The microbial community analysis using PCR-DGGE indicated the presence of uncultured anammox bacteria and members of the genus Candidatus Jettenia. The results evidenced the achievement of anammox cultures, although their start-up and kinetic characteristics were less favorable than those recorded in man-made systems. PRACTITIONER POINTS: Estuarine sediments were used as incubation seeds to obtain cultures with stable anammox activity. The sediments were fed with stoichiometric amounts of ammonium and nitrite, analyzing the physiological response variables and the microbial community. Sediments showed a stable anammox process after 90 days, converting the substrates into N2 and nitrate according to stoichiometry. Anammox cultures were achieved although their start-up and kinetic characteristics were less favorable than those recorded in man-made systems. Microbial community analysis using PCR-DGGE indicated the presence of uncultured anaerobic ammonia-oxidizing bacterium and members of genus Candidatus Jettenia.

The value of visible 5-ALA fluorescence and quantitative protoporphyrin IX analysis for improved surgery of suspected low-grade gliomas.

OBJECTIVE: In patients with suspected diffusely infiltrating low-grade gliomas (LGG), the prognosis is dependent especially on extent of resection and precision of tissue sampling. Unfortunately, visible 5-aminolevulinic acid (5-ALA) fluorescence is usually only present in high-grade gliomas (HGGs), and most LGGs cannot be visualized. Recently, spectroscopic probes were introduced allowing in vivo quantitative analysis of intratumoral 5-ALA-induced protoporphyrin IX (PpIX) accumulation. The aim of this study was to intraoperatively investigate the value of visible 5-ALA fluorescence and quantitative PpIX analysis in suspected diffusely infiltrating LGG. METHODS: Patients with radiologically suspected diffusely infiltrating LGG were prospectively recruited, and 5-ALA was preoperatively administered. During resection, visual fluorescence and absolute tissue PpIX concentration (CPpIX) measured by a spectroscopic handheld probe were determined in different intratumoral areas. Subsequently, corresponding tissue samples were safely collected for histopathological analysis. Tumor diagnosis was established according to the World Health Organization 2016 criteria. Additionally, the tumor grade and percentage of tumor cells were investigated in each sample. RESULTS: All together, 69 samples were collected from 22 patients with histopathologically confirmed diffusely infiltrating glioma. Visible fluorescence was detected in focal areas in most HGGs (79%), but in none of the 8 LGGs. The mean CPpIX was significantly higher in fluorescing samples than in nonfluorescing samples (0.693 µg/ml and 0.008 µg/ml, respectively; p < 0.001). A significantly higher mean percentage of tumor cells was found in samples with visible fluorescence compared to samples with no fluorescence (62% and 34%, respectively; p = 0.005), and significant correlation of CPpIX and percentage of tumor cells was found (r = 0.362, p = 0.002). Moreover, high-grade histology was significantly more common in fluorescing samples than in nonfluorescing samples (p = 0.001), whereas no statistically significant difference in mean CPpIX was noted between HGG and LGG samples. Correlation between maximum CPpIX and overall tumor grade was highly significant (p = 0.005). Finally, 14 (40%) of 35 tumor samples with no visible fluorescence and 16 (50%) of 32 LGG samples showed significantly increased CPpIX (cutoff value: 0.005 µg/ml). CONCLUSIONS: Visible 5-ALA fluorescence is able to detect focal intratumoral areas of malignant transformation, and additional quantitative PpIX analysis is especially useful to visualize mainly LGG tissue that usually remains undetected by conventional fluorescence. Thus, both techniques will support the neurosurgeon in achieving maximal safe resection and increased precision of tissue sampling during surgery for suspected LGG.Clinical trial registration no.: NCT01116661 (clinicaltrials.gov).

Simplified Model to Survey Tuberculosis Transmission in Countries Without Systematic Molecular Epidemiology Programs.

Systematic molecular/genomic epidemiology studies for tuberculosis surveillance cannot be implemented in many countries. We selected Panama as a model for an alternative strategy. Mycobacterial interspersed repetitive unit-variable-number tandem-repeat (MIRU-VNTR) analysis revealed a high proportion (50%) of Mycobacterium tuberculosis isolates included in 6 clusters (A-F) in 2 provinces (Panama and Colon). Cluster A corresponded to the Beijing sublineage. Whole-genome sequencing (WGS) differentiated clusters due to active recent transmission, with low single-nucleotide polymorphism-based diversity (cluster C), from clusters involving long-term prevalent strains with higher diversity (clusters A, B). Prospective application in Panama of 3 tailored strain-specific PCRs targeting marker single-nucleotide polymorphisms identified from WGS data revealed that 31.4% of incident cases involved strains A-C and that the Beijing strain was highly represented and restricted mainly to Colon. Rational integration of MIRU-VNTR, WGS, and tailored strain-specific PCRs could be a new model for tuberculosis surveillance in countries without molecular/genomic epidemiology programs.

5-Aminolevulinic Acid-Induced Fluorescence in Focal Cortical Dysplasia: Report of 3 Cases.

BACKGROUND: Three patients enrolled in a clinical trial of 5-aminolevulinic-acid (5-ALA)-induced fluorescence-guidance, which has been demonstrated to facilitate intracranial tumor resection, were found on neuropathological examination to have focal cortical dysplasia (FCD). OBJECTIVE: To evaluate in this case series visible fluorescence and quantitative levels of protoporphyrin IX (PpIX) during surgery and correlate these findings with preoperative magnetic resonance imaging (MRI) and histopathology. METHODS: Patients were administered 5-ALA (20 mg/kg) approximately 3 h prior to surgery and underwent image-guided, microsurgical resection of their MRI- and electrophysiologically identified lesions. Intraoperative visible fluorescence was evaluated using an operating microscope adapted with a commercially available blue light module. Quantitative PpIX levels were assessed using a handheld fiber-optic probe and a wide-field imaging spectrometer. Sites of fluorescence measurements were co-registered with both preoperative MRI and histopathological analysis. RESULTS: Three patients with a pathologically confirmed diagnosis of FCD (Types 1b, 2a, and 2b) underwent surgery. All patients demonstrated some degree of visible fluorescence (faint or moderate), and all patients had quantitatively elevated concentrations of PpIX. No evidence of neoplasia was identified on histopathology, and in 1 patient, the highest concentrations of PpIX were found at a tissue site with marked gliosis but no typical histological features of FCD. CONCLUSION: FCD has been found to be associated with intraoperative 5-ALA-induced visible fluorescence and quantitatively confirmed elevated concentrations of the fluorophore PpIX in 3 patients. This finding suggests that there may be a role for fluorescence-guidance during surgical intervention for epilepsy-associated FCD.

Red-light excitation of protoporphyrin IX fluorescence for subsurface tumor detection.

OBJECTIVE The objective of this study was to detect 5-aminolevulinic acid (ALA)-induced tumor fluorescence from glioma below the surface of the surgical field by using red-light illumination. METHODS To overcome the shallow tissue penetration of blue light, which maximally excites the ALA-induced fluorophore protoporphyrin IX (PpIX) but is also strongly absorbed by hemoglobin and oxyhemoglobin, a system was developed to illuminate the surgical field with red light (620-640 nm) matching a secondary, smaller absorption peak of PpIX and detecting the fluorescence emission through a 650-nm longpass filter. This wide-field spectroscopic imaging system was used in conjunction with conventional blue-light fluorescence for comparison in 29 patients undergoing craniotomy for resection of high-grade glioma, low-grade glioma, meningioma, or metastasis. RESULTS Although, as expected, red-light excitation is less sensitive to PpIX in exposed tumor, it did reveal tumor at a depth up to 5 mm below the resection bed in 22 of 24 patients who also exhibited PpIX fluorescence under blue-light excitation during the course of surgery. CONCLUSIONS Red-light excitation of tumor-associated PpIX fluorescence below the surface of the surgical field can be achieved intraoperatively and enables detection of subsurface tumor that is not visualized under conventional blue-light excitation. Clinical trial registration no.: NCT02191488 (clinicaltrials.gov).

Crystal structure of r-1,c-2-dibenzoyl-t-3,t-4-bis-(2-nitro-phen-yl)cyclo-butane.

The condensation reaction of aceto-phenone (1-phenyl-ethan-1-one) with 2-nitro-benzaldehyde in the molten state yielded the expected chalcone, (E)-3-(2-nitro-phen-yl)-1-phenyl-prop-2-en-1-one, and, unexpectedly, the title compound, C30H22N2O6, which results from the syn head-to-head [2 + 2] cyclo-addition of the chalcone. The mol-ecular structure of the dimer shows that the four benzene rings of the substituents are oriented in such a way that potential steric hindrance is minimized, whilst allowing some degree of inter-molecular π-π inter-actions for crystal stabilization. In the mol-ecule, one nitro group is disordered over two positions, with occupancies for each part of 0.876 (7) and 0.127 (7).

Selective screening of glutaric acid acidurias by capillary electrophoresis-mass spectrometry.

A sensitive and selective method for the separation and quantification of the three organic acids 3-hydroxy-3-methylglutaric acid, 3-methylglutaric acid, and glutaric acid in human urine samples by CE with mass spectrometry detection has been developed. This methodology is faster, simpler and less time-consuming, than other methodologies previously described, and requires of reduced amounts of reagents as well. Samples are first filtered and then diluted in water. For the electrophoretic separation, a 20mM ammonium acetate and 10% methanol solution at pH 9.1 was selected as the running electrolyte. With 5-s hydrodynamic injection, detection limits ranging from 15.5 to 39.3µM and linear responses ranging from the LOQ calculated for each analyte to more than 400µM were obtained for the analysis of the different organic acids in less than 13min. Remarkable selectivity is achieved by mass spectrometry detection using 0.25% of formic acid in 50% v/v 2-propanol-water solution as sheath liquid, and enough sensitivity without interferences from the matrices was obtained as well. This methodology has revealed as an efficient approach to help the 3-hydroxy-3-methylglutaric aciduria diagnoses in order to discard or confirm the occurrence of the disease as of the presence or absence of the expected increased levels of these analytes in samples of potential patients.

Temperature-mediated biosynthesis of the phytotoxin phaseolotoxin by Pseudomonas syringae pv. phaseolicola depends on the autoregulated expression of the phtABC genes.

Pseudomonas syringae pv. phaseolicola produces phaseolotoxin in a temperature dependent manner, being optimally synthesized between 18°C and 20°C, while no detectable amounts are present above 28°C. The Pht cluster, involved in the biosynthesis of phaseolotoxin, contains 23 genes that are organized in five transcriptional units. The function of most of the genes from the Pht cluster is still unknown and little information about the regulatory circuitry leading to expression of these genes has been reported. The purpose of the present study was to investigate the participation of pht genes in the regulation of the operons coded into the Pht cluster. We conducted Northern blot, uidA fusions and reverse transcription-PCR assays of pht genes in several mutants unable to produce phaseolotoxin. This allowed us to determine that, in P. syringae pv. phaseolicola NPS3121, genes phtABC are essential to prevent their own expression at 28°C, a temperature at which no detectable amounts of the toxin are present. We obtained evidence that the phtABC genes also participate in the regulation of the phtD, phtM and phtL operons. According to our results, we propose that PhtABC and other Pht product activities could be involved in the synthesis of the sulfodiaminophosphinyl moiety of phaseolotoxin, which indirectly could be involved in the transcriptional regulation of the phtA operon.

A connective tissue disorder may underlie ESSENCE problems in childhood.

BACKGROUND: Ehlers-Danlos syndrome hypermobility type, also known as Joint Hypermobility Syndrome (EDS-HT/JHS), is the most common hereditary disorder of the connective tissue (HDCT). It is characterized by tissue fragility, joint hypermobility and a wide range of articular and non-articular manifestations, which often appear in infancy. The clinical picture of EDS-HT/JHS is poorly known by the medical community, as is the presence of "ESSENCE" (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations) problems in affected children. AIM: The present work reviews the clinical and empirical evidence for ESSENCE difficulties in children with EDS-HT/JHS. METHOD: A narrative review of the literature was undertaken following a comprehensive search of scientific online databases and reference lists. This included publications of quantitative and qualitative research. RESULTS: Motor abnormality, hyperactivity/hypoactivity, inattention, speech/language, social interaction, behavioral, sleep, feeding and emotional problems are ESSENCE difficulties for which there is some evidence of an association with EDS-HT/JHS. CONCLUSION: Children with EDS-HT/JHS present ESSENCE problems that often coexist and tend to be recognized before the HDCT. Clinicians encountering children with ESSENCE problems should consider the possibility of an underlying HDCT such as EDS-HT/JHS, probably influencing neurodevelopmental attributes in a subgroup of children. Awareness of these interconnected clinical problems might help improve early referral, diagnosis and treatment of EDS-HT/JHS.

Neuron Morphology Influences Axon Initial Segment Plasticity.

In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation.

Characterization and standardization of tissue-simulating protoporphyrin IX optical phantoms.

Optical devices for measuring protoporphryin IX (PpIX) fluorescence in tissue are routinely validated by measurements in optical phantoms. Yet there exists limited data to form a consensus on the recipe for phantoms that both mimic the optical properties found in tissue and yield a reliable and stable relationship between PpIX concentration and the fluorescence remission intensity. This study characterizes the influence of multiple phantom components on PpIX fluorescence emission intensity, using Intralipid as the scattering source, bovine whole blood as the background absorber, and Tween as a surfactant to prevent PpIX aggregation. Optical measurements showed a linear proportionality (r > 0.99) between fluorescence intensity and PpIX concentration (0.1 to 10 µg/mL) over a range of Intralipid (1 to 2%) and whole blood (0.5 to 3%) for phantoms containing low surfactant (≤ 0.1%), with fluorescence intensities and scattering and absorption properties stable for 5 h after mixing. The role of surfactant in PpIX phantoms was found to be complex, as aggregation was evident in aqueous nonturbid phantoms with no surfactant (0% Tween), and avoided in phantoms containing Intralipid as the scattering source with no additional or low amounts of added surfactant (≤ 0.1% Tween). Conversely, phantoms containing higher surfactant content (>0.1% Tween) and whole blood showed interactions that distorted the fluorescence emissions.

Mathematical model to interpret localized reflectance spectra measured in the presence of a strong fluorescence marker.

Quantification of multiple fluorescence markers during neurosurgery has the potential to provide complementary contrast mechanisms between normal and malignant tissues, and one potential combination involves fluorescein sodium (FS) and aminolevulinic acid-induced protoporphyrin IX (PpIX). We focus on the interpretation of reflectance spectra containing contributions from elastically scattered (reflected) photons as well as fluorescence emissions from a strong fluorophore (i.e., FS). A model-based approach to extract µa and µ's in the presence of FS emission is validated in optical phantoms constructed with Intralipid (1% to 2% lipid) and whole blood (1% to 3% volume fraction), over a wide range of FS concentrations (0 to 1000 µg/ml 1000 µg/ml ). The results show that modeling reflectance as a combination of elastically scattered light and attenuation-corrected FS-based emission yielded more accurate tissue parameter estimates when compared with a nonmodified reflectance model, with reduced maximum errors for blood volume (22% versus 90%), microvascular saturation (21% versus 100%), and µs' (13% versus 207%). Additionally, quantitative PpIX fluorescence sampled in the same phantom as FS showed significant differences depending on the reflectance model used to estimate optical properties (i.e., maximum error 29% versus 86%). These data represent a first step toward using quantitative optical spectroscopy to guide surgeries through simultaneous assessment of FS and PpIX.

Sub-diffuse optical biomarkers characterize localized microstructure and function of cortex and malignant tumor.

This study uses a sub-diffusive light transport model to analyze fiber-optic measurements of reflectance spectra to recover endogenous tissue biomarkers and to correct raw fluorescence emissions for distortions from background optical properties. Measurements in tissue-simulating phantoms validated accurate recovery of the reduced scattering coefficient [(0.3-3.4 mm-1), error 10%], blood volume fraction [(1-3 vol%), error 7%], and a dimensionless metric of anisotropic scattering, γ, that is sensitive to submillimeter tissue ultrastructure [(1.29-2.06), error 11%]. In vivo sub-diffusive optical data acquired during clinical neurosurgeries characterize differences in microstructure (γ), perfusion (blood volume), and metabolism (PpIX fluorescence) between normal cortex and malignant tumor.

Síndrome de Ehlers-Danlos Clásico o Ehlers-Danlos tipo I - II / The Classic Ehlers-Danlos or Ehlers-Danlos type I - II

El Síndrome de Ehlers-Danlos Clásico o Ehlers-Danlos tipo I - II, al igual que el Ehlers-Danlos Vascular son poco frecuentes, si se les compara con el tipo Hipermovible o tipo III, el que afecta al 39 por ciento de la población chilena. Es importante porque al tener marcada hiperlaxitud articular (contorsionistas) presenta subluxaciones importantes. Además, debido a la gran hiperextensibilidad de la piel, la que es muy frágil, tiene tendencia a heridas y a mala cicatrización. Al igual que los otros tipos de Síndrome de Ehlers-Danlos, el Clásico puede tener Hábito Marfanoide o/y Disautonomía. Se puede presentar también con Osteopenia u Osteoporosis, hernias, várices, hemorroides y prolapso. Tiene herencia autosómica dominante y la alteración genética es conocida (COL5A1 o COL5A2).

The Classic Ehlers-Danlos or Ehlers Danlos type I - II, as the Vascular Ehlers-Danlos are infrequent, as compared with the Hypermobile or type III, that affects 39 percent of the chilean population. It is important because due to the marked joint hypermobility (contosionists) presents important subluxations. Also due to the important skin laxity, which is fragile it has tendency to injuries and poor cicatrization. As the other Ehlers-Danlos types, the Classic Ehlers-Danlos can present with Marfanoid habitus and or Dysautonomia. It also can have Osteopenia or Osteoporosis, hernias, varicose veins, hemorrhoids and prolapse. It has dominant Autosomic inheritance and the genetic alteration is known (COL5A1 or COL5A2).

Síndrome de Ehlers-Danlos vascular: complicaciones vasculares graves en enfermos con hipermovilidad articular / Vascular Ehlers-Danlos syndrome: severe vascular complications in patients with articular hypermobility

El Síndrome de Ehlers-Danlos Vascular es una de las Alteraciones Hereditarias del Tejido Conectivo. Es poco frecuente, pero es de alta morbilidad y mortalidad. Se debe a una mutación del gen COL3A1, que da debilidad del tejido colágeno, por lo que se pueden producir complicaciones graves afectando a la piel, tubo digestivo, hígado, pulmón y sistema vascular. Se pueden producir rupturas intestinales, neumotórax espontáneo, dilatación o ruptura aortica y anuerismas, lo que puede llevar a la muerte súbita del paciente.

The Vascular Ehlers-Danlos is one of Hereditary Diseases of Connective Tissue. Has low prevalence, but high morbidity and mortality. It is due to a COL3A1 gene mutation, producing tissue fragility, which can produce serious complications in the skin, digestive tract, liver, lungs and in the vascular system. It is frequently associated to intestinal ruptures, spontaneous pneumothorax, dilation or rupture of the aorta anuerism, which can lead to sudden death.

Evolutionary history exposes radical diversification among classes of interaction partners of the MLLE domain of plant poly(A)-binding proteins.

BACKGROUND: Poly(A)-binding proteins (PABPs) are evolutionarily conserved proteins that have important functions in the regulation of translation and the control of mRNA stability in eukaryotes. Most PABPs encode a C-terminal domain known as the MLLE domain (previously PABC or CTC), which can mediate protein interactions. In earlier work we identified and predicted that four classes of MLLE-interacting proteins were present in Arabidopsis thaliana, which we named CID A, B, C, and D. These proteins encode transcription-activating domains (CID A), the Lsm and LsmAD domains of ataxin-2 (CID B), the CUE and small MutS-related domains (CID C), and two RNA recognition domains (CID D). We recently found that a novel class that lacks the LsmAD domain is present in CID B proteins. RESULTS: We extended our analysis to other classes of CIDs present in the viridiplantae. We found that novel variants also evolved in classes CID A and CID C. A specific transcription factor domain is present in a distinct lineage in class A, and a variant that lacks at least two distinct domains was also identified in a divergent lineage in class C. We did not detect any variants in Class D CIDs. This class often consists of four to six highly conserved RNA-binding proteins, which suggests that major redundancy is present in this class. CONCLUSIONS: CIDs are likely to operate as components of posttranscriptional regulatory assemblies. The evident diversification of CIDs may be neutral or may be important for plant adaptation to the environment and for acquisition of specific traits during evolution. The fact that CIDs subclasses are maintained in early lineages suggest that a presumed interference between duplicates was resolved, and a defined function for each subclass was achieved.

The Potential of Algarrobo (Prosopis chilensis (Mol.) Stuntz) for Regeneration of Desertified Soils: Assessing Seed Germination Under Saline Conditions.

Due to their multipurpose use, leguminous trees are desirable for the restoration of degraded ecosystems. Our aim was to investigate seed germination of the leguminous tree Prosopis chilensis in response to salinity, one of the major abiotic challenges of desertified soils. Germination percentages of seed from 12 wild P. chilensis populations were studied. Treatments included four aqueous NaCl concentrations (150, 300, 450, and 600 mM). In each population, the highest germination percentage was seen using distilled water (control), followed closely by 150 mM NaCl. At 300 mM NaCl or higher salt concentration, germination was progressively inhibited attaining the lowest value at 450 mM NaCl, while at 600 mM NaCl germination remained reduced but with large variation among group of samples. These results allowed us to allocate the 12 groups from where seeds were collected into three classes. First, the seeds from Huanta-Rivadavia showed the lowest percent germination for each salt condition. The second group was composed of moderately salt-tolerant seeds with 75% germination at 300 mM NaCl, followed by 50% germination at 450 mM NaCl and 30% germination at 600 mM NaCl. The third group from Maitencillo and Rapel areas was the most salt tolerant with an impressive seed germination level of 97% at 300 mM NaCl, 82 % at 450 mM NaCl, and 42 % at 600 mM NaCl. Our results demonstrate that P. chilensis seeds from these latter localities have an increased germination capability under saline stress, confirming that P. chilensis is an appropriate species to rehabilitate desertified soils.

Cuando sospechar el síndrome de Ehlers-Danlos tipo III, también llamadosindrome de Ehlers-Danlos hipermovible / When to suspect Ehlers-Danlos type III, also known as hypermobile Ehlers-Danlos syndrome

Ehlers-Danlos Syndrome type III is a very frequent disease, with dominant inheritance, that usually goes undiagnosed, due to lack of knowledge of the disease by physicians. In this article we discuss in detail clinical signs and symptoms that will enable doctors to suspect the diagnosis...

El síndrome de Ehlers-Danlos tipo III es una enfermedad hereditaria dominante, muy frecuente, que generalmente no es diagnosticada, debido a falta de conocimiento del tema por parte de los médicos. En este artículo se revisan, en detalle, los signos y síntomas clínicos de la enfermedad con el fin de ayudar al médico a sospechar el diagnóstico...