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The placement of endotracheal prostheses is a procedure used to treat tracheal lesions when no other surgical options are available. Unfortunately, this technique remains controversial. Both silicon and metallic stents are used with unpredictable success rates, as they have advantages but also disadvantages. Typical side effects include restenosis due to epithelial hyperplasia, obstruction and granuloma formation. Repeat interventions are often required. Biodegradable stents are promising in the field of cardiovascular biomechanics but are not yet approved for use in the respiratory system. The aim of the present study is to summarize important information and to evaluate the role of different geometrical features for the fabrication of a new tracheo-bronchial prosthesis prototype, which should be biodegradable, adaptable to the patient's lesion and producible by 3D printing. A parametric design and subsequent computational analysis using the finite element method is carried out. Two different stent designs are parameterized and analyzed. The biodegradable material chosen for simulations is polylactic acid. Experimental tests are conducted for assessing its mechanical properties. The role of the key design parameters on the radial force of the biodegradable prosthesis is investigated. The computational results allow us to elucidate the role of the pitch angle, the wire thickness and the number of cells or units, among other parameters, on the radial force. This work may be useful for the design of ad hoc airway stents according to the patient and type of lesion.

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Cellulose is an abundant component of plant cell wall matrices, and this para-crystalline polysaccharide is synthesized at the plasma membrane by motile Cellulose Synthase Complexes (CSCs). However, the factors that control CSC activity and motility are not fully resolved. In a targeted chemical screen, we identified the alkylated nojirimycin analog N-Dodecyl Deoxynojirimycin (ND-DNJ) as a small molecule that severely impacts Arabidopsis seedling growth. Previous work suggests that ND-DNJ-related compounds inhibit the biosynthesis of glucosylceramides (GlcCers), a class of glycosphingolipid associated with plant membranes. Our work uncovered major changes in the sphingolipidome of plants treated with ND-DNJ, including reductions in GlcCer abundance and altered acyl chain length distributions. Crystalline cellulose content was also reduced in ND-DNJ-treated plants as well as plants treated with the known GlcCer biosynthesis inhibitor N-[2-hydroxy-1-(4-morpholinylmethyl)-2-phenyl ethyl]-decanamide (PDMP) or plants containing a genetic disruption in GLUCOSYLCERAMIDE SYNTHASE (GCS), the enzyme responsible for sphingolipid glucosylation that results in GlcCer synthesis. Live-cell imaging revealed that CSC speed distributions were reduced upon treatment with ND-DNJ or PDMP, further suggesting an important relationship between glycosylated sphingolipid composition and CSC motility across the plasma membrane. These results indicate that multiple interventions compromising GlcCer biosynthesis disrupt cellulose deposition and CSC motility, suggesting that GlcCers regulate cellulose biosynthesis in plants.

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La personalidad es el trasfondo que determina la forma de pensar, sentir y comportarse e influye en la psicopatología. En este contexto, resulta relevante el estudio de la relación entre personalidad y ansiedad en la adolescencia. El principal objetivo de nuestro estudio es analizar las diferencias entre casos con Trastornos por Ansiedad (TA) y una muestra de población general (PG) en los diferentes perfiles / prototipos de personalidad (PRP) derivados del el Inventario clínico para adolescentes de Millon (MACI). Un segundo objetivo fue estudiar el modelo más parsimonioso de PRP capaz de predecir TA. Para responder a estos objetivos se utilizó un diseño observacional analítico y se realizó un muestreo aleatorio de adolescentes en PG (n = 461) y consecutivo de pacientes con TA, valorados según criterios DSM-5 (n = 77). Los instrumentos de medida utilizados fueron el MACI y Adolescent Symptom Inventory. Los PRP Introvertidos, Inhibidos, Pesimistas, Sumisos, Oposicionistas, Autopunitivos y Límites presentan una media significativamente mayor en TA y los PRP Histriónico y Egocéntrico en PG. El modelo más parsimonioso de PRP que mejor predice TA está conformado por tener mayor edad y los PRP más límite y menos rebelde. El estudio ofrece una imagen novedosa de los PRP en casos de TA que invitan a su estudio clínico, favoreciendo nuevos caminos de investigación que incluyan la personalidad en la heterogeneidad del trastorno. (AU)

Personality is the background that determines the way we think, feel and behave and influences psychopathology. In this context, the study of the relationship between personality and anxiety in adolescence is important. The main objective of our study is to analyse the differences between cases with Anxiety Disorders (AD) and a sample of general population (GP) in the different personality profiles / prototypes (PRP) derived from the Millon Adolescent Clinical Inventory (MACI). Secondary objective: to study the most parsimonious predictive model of PRP to predict AD. To respond to these objectives, an observational analytical design was used and a random sampling of adolescents in GP (n = 461) and consecutive sampling of patients with AD, assessed according to DSM-5 criteria (n = 77) was performed. The measurement instruments used were the MACI and the Adolescent Symptom Inventory. Introverted, Inhibited, Doleful, Submissive, Oppositional, Self-demeaning and Borderline PRPs present a significantly higher mean in AD and the Dramatizing and Egotistic PRPs in GP. The most parsimonious PRP model that best predicts AD is shaped by having older age and the most Borderline and least Unruly PRPs. The study offers a novel picture of PRPs in AD cases that invite their clinical study, favoring new paths of research that include personality in the heterogeneity of the disorder. (AU)

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RESUMEN El schwannoma de colon es una entidad sumamente rara que puede debutar como lesión subepitelial con signos ulcerativos de melena y anemia. El estudio de imágenes nos orienta a la localización mientras que la biopsia colonoscópica no es de ayuda. Muchas veces el diagnóstico y tratamiento se efectúa con la resección de la lesión en tanto que el diagnóstico final se realiza en el posoperatorio por histopatología y por la inmunohistoquímica, la cual muestra positividad intensa para S100 y vimentina en las células tumorales con un índice de proliferación KI67 menor al 1%, por lo que se concluye que se trata de una lesión benigna. Presentamos el siguiente caso por su dificultad diagnóstica pre e intraoperatoria, clínica inespecífica y diagnóstico definitivo por inmunohistoquímica.

ABSTRACT Colon schwannoma is an extremely rare entity that may debut as a subepithelial lesion with ulceration signs, such as melena and anemia. Imaging studies guide us to localization, while a colonoscopy biopsy is not helpful. Many times, the diagnosis and treatment are made with lesion resection, and the final diagnosis is postoperatively made with histopathology and immunohistochemistry, which shows intense positivity for S100 and vimentin in tumor cells with a KI67 proliferation index of less than 1%, therefore, it is concluded that this is a benign lesion. We present this case due to its pre- and intraoperative diagnostic difficulty, non-specific symptoms, and its definitive diagnosis that was achieved with immunohistochemistry.

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The Costa Rican Paso Horse (CPC) is a breed developed in Costa Rica. The objectives were to estimate the genetic structure and evaluate the levels of genetic variability of the population. The genotypes of 14 microsatellites in 3654 records (2052 females and 1602 males) were analyzed. Expected (He) and observed (Ho) heterozygosity, polymorphic information content (CIP), fixation index (FIS), Shannon index, as well as Hardy-Weinberg disequilibrium (DHW) were evaluated. Kinship relationships (Rij) were estimated throughout the entire population. The effective population size (Ne) was calculated, alternating allele frequencies less than 0.05, 0.02 and 0.01. The Bayesian clustering study was carried out to infer how many lines are appropriate from the analysis of genotypes using multiple loci. The number of alleles per locus ranged from 7 to 17, with an average value of 9.6; nine loci presented DHW (P < 0.05); two loci presented negative FIS values, the same as Ho > He; the average of CIP, Ho and He was 0.254, 0.756 and 0.785, respectively. At the 12 loci where He > Ho, the differences ranged from 0.002 to 0.341 (0.036 on average). For Ne, the estimates were 201.9, 230.1, and 241.5. In the Rij, 54.86% of the estimates were in the interval of 0.01 to 77.7%. The number of lines that define the population corresponds to three, with an approximate composition of 33.1%, 32.4% and 34.5%, respectively. The CPC, as a subdivided population with DHW and a reduction in heterozygotes may be associated with possible Wahlund effects. Keywords: Wahlund effect, equines, genetic markers, synthetic breed, Hardy Weinberg.

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Attention Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder in childhood that often persists into adulthood. Objectively diagnosing ADHD can be challenging due to the reliance on subjective questionnaires in clinical assessment. Fortunately, recent advancements in artificial intelligence (AI) have shown promise in providing objective diagnoses through the analysis of medical images or activity recordings. These AI-based techniques have demonstrated accurate ADHD diagnosis; however, the growing complexity of deep learning models has introduced a lack of interpretability. These models often function as black boxes, unable to offer meaningful insights into the data patterns that characterize ADHD. OBJECTIVE: This paper proposes a methodology to interpret the output of an AI-based diagnosis system for combined ADHD in age and gender-stratified populations. METHODS: Our system is based on the analysis of 24 hour-long activity records using Convolutional Neural Networks (CNNs) to classify spectrograms of activity windows. These windows are interpreted using occlusion maps to highlight the time-frequency patterns explaining ADHD activity. RESULTS: Significant differences in the frequency patterns between ADHD and controls both in diurnal and nocturnal activity were found for all the populations. Temporal dispersion also presented differences in the male population. CONCLUSION: The proposed interpretation techniques for CNNs highlighted gender- and age-related differences between ADHD patients and controls. Leveraging these differences could potentially lead to improved diagnostic accuracy, especially if a larger and more balanced dataset is utilized. SIGNIFICANCE: Our findings pave the way for the development of an AI-based diagnosis system for ADHD that offers interpretability, thereby providing valuable insights into the underlying etiology of the disease.

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Antecedentes: Existen pocos estudios que relacionen personalidad y trastorno por déficit de atención con hiperactividad (TDAH) en adolescentes. Objetivo: estudiar diferencias entre casos con TDAH y población general en prototipos de personalidad (PRP) derivados del Inventario clínico para adolescentes de Millon (MACI). Material y Método: Diseño observacional analítico. Muestreo aleatorio en población general (n = 461) y consecutivo de pacientes con TDAH valorados según criterios DSM-5 (n = 85), en adolescentes entre 13 y 17 años. Instrumentos de medida: MACI y Adolescent Symptom Inventory. Resultados: los PRP Pesimista, Rudo, Rebelde, Oposicionista, Autopunitivo y Límite presentan una media significativamente mayor en TDAH y los PRP Sumiso y Conformista, en población general. El modelo de PRP que mejor prediceTDAH está conformado por tener sexo masculino y los PRP Rudo, Límite, Sumiso y Autopunitivo, clasificando el 82.4% de los casos. Conclusión: Los casos de TDAH tienen PRP diferenciales con la población general que invitan a su estudio clínico e intervención terapéutica. El estudio ofrece una imagen novedosa de los PRP en casos de TDAH y abre nuevos caminos de investigación que incluyan la personalidad al explicar la heterogeneidad del trastorno. (AU)

Background: There are few studies linking personality and Attention Deficit Hyperactivity Disorder (ADHD) in adolescents. Research objective: to study differences between cases with ADHD and the general population in personality prototypes (PRP) derived from the Millon Clinical Inventory for Adolescents (MACI). Material and Method: Analytical observational design. Random sampling in the general population (n = 461) and consecutive of patients with ADHD evaluated according to DSM-5 criteria (n = 85), in adolescents between 13 and 17 years old. Measurement instruments: MACI and Adolescent Symptom Inventory. Results: ADHD presents a significantly higher mean in Doleful, Forceful, Unruly, Oppositional, Self-demeaning and Borderline PRP and the general population in Submissive and Conforming PRP. The PRP model that best predicts ADHD includes male sex and the Forceful, Borderline, Submissive and Self-demeaning PRP. The model classifies 82.4% of the cases. Conclusion. ADHD cases have differential PRP in comparison with the general population, which invites their clinical study and therapeutic intervention. The study offers a novel image of PRP in ADHD and opens new lines of research that include personality when explaining the heterogeneity of the disorder. (AU)

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One of the main key aspects in ensuring that a transplant evolves correctly is the sterility of the medium. Decellularized tracheal transplantation involves implanting an organ that was originally in contact with the environment, thus not being sterile from the outset. While the decellularization protocol (through detergent exposition [2% sodium dodecyl sulfate], continuous stirring, and osmotic shocks) is conducted in line with aseptic measures, it does not provide sterilization. Therefore, one of the main challenges is ensuring sterility prior to in vivo implantation. Although there are established gamma radiation sterilization protocols for inorganic materials, there are no such measures for organic materials. Additionally, the protocols in place for inorganic materials cannot be applied to organic materials, as the established radiation dose (25 kGy) would completely destroy the implant. This paper studies the effect of an escalated radiation dose in a decellularized rabbit trachea. We maintained the dose range (kGy) and tested escalated doses until finding the minimal dose at which sterilization is achieved. After determining the dose, we studied effects of it on the organ, both histologically and biomechanically. We determined that while 0.5 kGy did not achieve sterility, doses of both 1 kGy and 2 kGy did, with 1 kGy, therefore, being the minimal dose necessary to achieve sterilization. Microscopic studies showed no relevant changes compared to non-sterilized organs. Axial biomechanical characteristics were not altered at all, and only a slight reduction in the force per unit of length that the organ can radially tolerate was observed. We can therefore conclude that 1 kGy achieves complete sterilization of decellularized rabbit trachea with a minimal, if any, effects on the organ.

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El objetivo principal del estudio fue analizar las diferencias entre muestra general y clínica en los prototipos de personalidad (PRP) del “Inventario clínico para adolescentes de Millón” (MACI). La metodología incluyó un diseño observacional y analítico, utilizando un muestreo de participantes (13-17 años) aleatorio polietápico, estratificado y proporcional por conglomerados en muestra general (n= 461) y un muestreo consecutivo en muestra clínica (n= 219). Encontramos que los PRP introvertido, inhibido, pesimista, rudo, oposicionista, autopunitivo y límite presentan una media significativamente mayor en muestra clínica y los PRP histriónico y conformista en muestra general. Se observa ausencia de diferencias significativas en los PRP egocéntrico, sumiso y rebelde. En la variable sexo observamos más diferencias significativas de PRP en muestra clínica que en la general y en la variable edad encontramos una tendencia lineal significativa descendente en los PRP sumiso o conformista y ascendente en los PRP rebelde y rudo en muestra general. El clínico debe estar alerta ante la interpretación de los PRP del MACI que no diferencian entre muestra general y clínica. (AU)

The main objective of the study was to analyze the differences between samples from general and clinical sample in personality prototypes (PRP), derived from the Millon Adolescent Clinical Inventory (MACI). The methodology included an analytical and observational design with a random, multi-stage, stratified and proportional cluster sampling in general sample (n= 461) and consecutive sampling of clinical sample (n= 219), in adolescents between 13 and 17 years of age. We found introvert, inhibited, doleful, forceful, oppositional, self-demeaning and borderline PRP in the clinical sample and dramatizing and conforming PRP in the general sample present a significantly higher mean. There is a relevant absence of significant differences in egotistic, submissive and unruly PRP. By sex, more significant differences in PRP are observed in the clinical sample. By age, a significant downward linear trend in the submissive and conforming PRP is observed, as well as an upward trend in the unruly and forceful PRP in the general sample. The clinician must be alert in the interpretation of the MACI PRP that do not differentiate between general and clinical samples. (AU)

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Epilepsy represents a challenge in the management of patients with brain tumors. Epileptic seizures are one of the most frequent comorbidities in neuro-oncology and may be the debut symptom of a brain tumor or a complication during its evolution. Epileptogenic mechanisms of brain tumors are not yet fully elucidated, although new factors related to the underlying pathophysiological process with possible treatment implications have been described. In recent years, the development of new anti-seizure medications (ASM), with better pharmacokinetic profiles and fewer side effects, has become a paradigm shift in many clinical scenarios in neuro-oncology, being able, for instance, to adapt epilepsy treatment to specific features of each patient. This is crucial in several situations, such as patients with cognitive/psychiatric comorbidity, pregnancy, or advanced age, among others. In this narrative review, we provide a rationale for decision-making in ASM choice for neuro-oncologic patients, highlighting the strengths and weaknesses of each drug. In addition, according to current literature evidence, we try to answer some of the most frequent questions that arise in daily clinical practice in patients with epilepsy related to brain tumors, such as, which patients are the best candidates for ASM and when to start it, what is the best treatment option for each patient, and what are the major pitfalls to be aware of during follow-up.

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Estudiamos la existencia de ritmo circanual en el mes de nacimiento en participantes con trastorno de déficit de atención e hiperactividad (TDAH)y analizamos la asociación entre meses de nacimiento y TDAH. La muestra incluye 10978 participantes (1778 TDAH / 9200 no TDAH), entre 3 y18 años, reclutados mediante muestreo consecutivo de primeras consultas atendidas en salud mental entre 1992 y 2021. Los participantes conTDAH presentan un ritmo circanual significativo en los meses de nacimiento, con una acrofase en octubre. Nacer en el último cuatrimestre del añoincrementa significativamente la probabilidad de ser diagnosticado TDAH, controlando el efecto de sexo y edad. Con el transcurso de los meses delaño, existe una tendencia lineal creciente significativa de ser diagnosticado de TDAH, no observada en población general, ni en casos sin TDAH.Es necesario tener precaución en el diagnóstico y tratamiento de los niños nacidos en los últimos meses del año, que, por su mayor inmadurez encomparación con los demás niños de la clase, pudieran ser diagnosticados y tratados erróneamente como TDAH. (AU)

We studied the existence of circanual rhythm in the month of birthin participants with attention deficit hyperactivity disorder (ADHD) and analyzed the association between months of birth and ADHD. We analyzed10,978 participants (1,778 ADHD/9,200 non-ADHD), aged 3 to 18 years. A consecutive sample of first visits to mental health between 1992 and2021 is used. Participants with ADHD exhibit a significant circannual rhythm in the months of birth, with an acrophase in October. Being born in thelast quarter of the year significantly increases the probability of being diagnosed with ADHD, controlling for the effect of sex and age. As the monthsof the year go by, there is a significant increasing linear trend of being diagnosed with ADHD, which is not observed neither in general populationnor in cases without ADHD. Caution is necessary in diagnosis and treatment of children born in the last months of year, who, due to their greaterimmaturity compared to the other children in class, could be misdiagnosed and treated as ADHD. (AU)

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Objective The aim of the study is to examine the relationship between secondhand smoke (SHS) and angina using the National Health and Nutrition Examination Survey database over a 12-year period. Methods Self-reported smoking status and cotinine levels were used to identify exposure groups (smokers, nonsmokers, and secondhand smokers), and medical history of angina was also collected via a self-report survey. The association between exposure to SHS and angina was analyzed using odd ratios with 95% confidence intervals calculated using two logistic regression models. Results The study found that when aggregating data from all 12 years, secondhand smokers are 42.9% significantly more likely to report having experienced angina, while smokers were 97.7% significantly more likely to report having angina compared with nonsmokers. Conclusions This study is the first of its kind to examine data from a national database over a 12-year period to determine an association between SHS and angina outcomes, thus highlighting the importance of reducing SHS exposure to improve cardiovascular health.

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Central nervous system involvement related to decompression sickness (DCS) is a very rare complication of breath-hold diving. So far, it has been postulated that repeated dives with short surface intervals represent a key factor in the development of breath-holding-related DCS. We report the case of a breath-hold diver who, after repeated immersion, developed DCS with brain involvement. After treatment in a hyperbaric chamber, there was a clinical improvement in the symptoms. Magnetic resonance imaging of the brain showed hyperintense lesions in long-time repetition sequences (FLAIR, T2WI) in the left frontal and right temporal lobes. Diffusion-weighted imaging (DWI) sequences and the apparent diffusion coefficient (ADC) map were characteristic of vasogenic edema, allowing us to exclude the ischemic nature of the process. These findings, together with the acute clinical presentation, the resolution of lesions in evolutionary radiological controls and the possible involvement of blood-brain barrier/endothelial dysfunction in DCS, could suggest a new form of posterior reversible encephalopathy syndrome (PRES)-like presentation of DCS. This would represent a novel mechanism to explain the pathophysiology of this entity. We conducted a literature review, analyzing the pathophysiological and neuroimaging characteristics of DCS in breath-hold diving based on a case of this rare disease.

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El envejecimiento activo constituye un tema de especial relevancia en una época donde la necesidad de afrontar los desafíos y oportunidades del siglo XXI han propiciado nuevas formas de entender la educación. Así, el modelo de aprendizaje basado en competencias implantado actualmente en los sistemas educativos europeos, latinoamericanos y de otras zonas debe ser considerado en todos los grupos de edad independientemente de criterios geográficos o sociodemográficos. En la legislación educativa española las competencias son definidas como las «capacidades para aplicar de forma integrada los contenidos propios de cada enseñanza y etapa educativa, con el fin de lograr la realización adecuada de actividades y la resolución eficaz de problemas complejos». Como se deduce de esta definición, el gran reto se basa en llevarlas a la práctica en los procesos de enseñanza-aprendizaje. En este sentido, se presenta el Conocimiento Tradicional (CT) como una herramienta para favorecer el diálogo, la salud intergeneracional y por consiguiente la atención a nuestros mayores desde la escuela a la universidad. Además, el encuentro entre generaciones en diferentes etapas educativas puede poner en valor la experiencia de vida de las personas mayores y el desarrollo de competencias bidireccionales fruto de esa interacción. Actualmente, el “Inventario Español de los Conocimientos Tradicionales relativos a la Biodiversidad” (IECTB), elaborado para dar cumplimiento a la Ley 42/2007, de 13 de diciembre, del Patrimonio Natural y de la Biodiversidad, es un punto de referencia para el trabajo en gerontología social y el desarrollo de materiales didácticos con la filosofía pedagógica planteada. (AU)

Active ageing is a subject of particular relevance at a time when the need to face the challenges and opportunities of the 21st century has led to new ways of understanding education. Thus, the competency-based learning model currently implemented in European, Latin American and other educational systems must be considered in all age groups regardless of geographic or socio-demographic criteria. In the Spanish education legislation, competences are defined as the “abilities to apply the content of each stage of teaching and learning in an integrated manner, in order to attain the appropriate performance of activities and the effective resolution of complex problems”. As can be deduced from this definition, the great challenge lies in putting them into practice in the teaching-learning processes. In this respect, Traditional Knowledge (TK) is presented as a tool to encourage dialogue, intergenerational health and, consequently, care for our elders from school to university. Moreover, the encounter between generations at different educational stages can enhance the life experience of older people and the development of two-way skills resulting from this interaction. Currently, the «Inventario Español de los Conocimientos Tradicionales relativos a la Biodiversidad» (IECTB) (Spanish Inventory of Traditional Knowledge related to Biodiversity), drawn up to comply with Law 42/2007 of 13 December, on Natural Heritage and Biodiversity, is a reference point for the work on social gerontology and the development of teaching materials with the proposed pedagogical philosophy. (AU)

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Epigenetic variation plays a significant role in normal development and human diseases including cancer, in part through post-translational modifications (PTMs) of histones. Identification and profiling of changes in histone PTMs, and in proteins regulating PTMs, are crucial to understanding diseases, and for discovery of epigenetic therapeutic agents. In this study, we have adapted and validated an antibody-based reverse phase protein array (RPPA) platform for profiling 20 histone PTMs and expression of 40 proteins that modify histones and other epigenomic regulators. The specificity of the RPPA assay for histone PTMs was validated with synthetic peptides corresponding to histone PTMs and by detection of histone PTM changes in response to inhibitors of histone modifier proteins in cell cultures. The useful application of the RPPA platform was demonstrated with two models: induction of pluripotent stem cells and a mouse mammary tumor progression model. Described here is a robust platform that includes a rapid microscale method for histone isolation and partially automated workflows for analysis of histone PTMs and histone modifiers that can be performed in a high-throughput manner with hundreds of samples. This RPPA platform has potential for translational applications through the discovery and validation of epigenetic states as therapeutic targets and biomarkers. SIGNIFICANCE: Our study has established an antibody-based reverse phase protein array platform for global profiling of a wide range of post-translational modifications of histones and histone modifier proteins. The high-throughput platform provides comprehensive analyses of epigenetics for biological research and disease studies and may serve as screening assay for diagnostic purpose or therapy development.

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The freshwater crab genus Tehuana Rodríguez & Smalley in Smalley, 1970 includes eight species distributed in southeastern Mexico. A recent review of organisms belonging to this genus uncovered new variations in the male gonopod morphology. A phylogenetic analysis based on molecular characters using three genes (H3, 16S, and COI) resulted in the identification of two new species which are described herein: Tehuanaayotzintepecensis sp. nov. from Oaxaca and Tehuanacol sp. nov. from Veracruz. New diagnoses are provided for those species that had very brief descriptions lacking the treatment of important taxonomic characters and an identification key for all the species in the genus is also given. A discussion of the distribution of all the species in Tehuana in the Isthmus of Tehuantepec is presented.

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Two new genera from the Chimalapas region in eastern Oaxaca, and from Zongolica, Veracruz, Mexico are presented. Mokayathelphusa angelsotoi n. gen., n. sp., which is described from Oaxaca, is placed in the subfamily Pseudothelphusinae due to the presence of a caudomarginal projection that ends apically in an ornamented plate. Alvarezius n. gen. is erected to accommodate A. zongolicae (Alvarez, Villalobos & Moreno, 2012) n. comb. This species was described in Pseudothelphusa, but a recent molecular phylogenetic analysis based on partial sequences of three genes (COI, 16S and H3) places this species outside the genus Pseudothelphusa and as a sister lineage to Tehuana. These results in combination with a morphological analysis support the establishment of the new genus.

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