Role of intraflagellar transport in transcriptional control during flagellar regeneration in Chlamydomonas.

Biosynthesis of organelle precursors is a central part of the organelle size control problem, but what systems are required to control precursor production? Genes encoding flagellar proteins are up-regulated during flagellar regeneration in Chlamydomonas, and this up-regulation is critical for flagella to reach their final length, but it not known how the cell triggers these genes during regeneration. We present two models based on transcriptional repressor that is produced either in the flagellum or in the cell body and sequestered in the growing flagellum. Both models lead to stable flagellar length control and can reproduce the observed dynamics of gene expression. The two models make opposite predictions regarding the effect of mutations that block intraflagellar transport (IFT). Using quantitative measurements of gene expression, we show that gene expression during flagellar regeneration is greatly reduced in mutations of the heterotrimeric kinesin-2 that drives IFT. This result is consistent with the predictions of the model in which a repressor is sequestered in the flagellum by IFT. Inhibiting axonemal assembly has a much smaller effect on gene expression. The repressor sequestration model allows precursor production to occur when flagella are growing rapidly, representing a form of derivative control.

Single-cell system using monolithic PMUTs-on-CMOS to monitor fluid hydrodynamic properties.

In this work, a single cell capable of monitoring fluid density, viscosity, sound velocity, and compressibility with a compact and small design is presented. The fluid measurement system is formed by a two-port AlScN piezoelectric micromachined ultrasonic transducer (PMUT) with an 80 µm length monolithically fabricated with a 130 nm complementary metal-oxide semiconductor (CMOS) process. The electrode configuration allows the entire system to be implemented in a single device, where one electrode is used as an input and the other as an output. Experimental verification was carried out by exploiting the features of piezoelectric devices such as resonators and acoustic transducers, where a frequency shift and amplitude variation are expected because of a change in density and viscosity. A sensitivity of 482 ± 14 Hz/kg/m3 demonstrates the potential of the system compared to other dual-electrode PMUTs. In addition, according to the acoustic measurement, the sound velocity, fluid compressibility, and viscosity coefficient can be extracted, which, to the best of our knowledge, is novel in these PMUT systems.

Enhancing AlN PMUTs' Acoustic Responsivity within a MEMS-on-CMOS Process.

In this paper, guidelines for the optimization of piezoelectrical micromachined ultrasound transducers (PMUTs) monolithically integrated over a CMOS technology are developed. Higher acoustic pressure is produced by PMUTs with a thin layer of AlN piezoelectrical material and Si3N4 as a passive layer, as is studied here with finite element modeling (FEM) simulations and experimental characterization. Due to the thin layers used, parameters such as residual stress become relevant as they produce a buckled structure. It has been reported that the buckling of the membrane due to residual stress, in general, reduces the coupling factor and consequently degrades the efficiency of the acoustic pressure production. In this paper, we show that this buckling can be beneficial and that the fabricated PMUTs exhibit enhanced performance depending on the placement of the electrodes. This behavior was demonstrated experimentally and through FEM. The acoustic characterization of the fabricated PMUTs shows the enhancement of the PMUT performance as a transmitter (with 5 kPa V-1 surface pressure for a single PMUT) and as a receiver (12.5 V MPa-1) in comparison with previously reported devices using the same MEMS-on-CMOS technology as well as state-of-the-art devices.

High Accuracy Ultrasound Micro-Distance Measurements with PMUTs under Liquid Operation.

Ultrasonic systems driven by multi-frequency continuous waves (MFCW) have been used for range distance measurement, offering high accuracy in long and medium range distance estimation. However, the use of continuous waves in very short-distance measurements causes large errors due to multipath reflections. This paper presents a new strategy to estimate very short relative distances with high accuracy based on the use of multi-frequency pulsed waves (MFPW). The proposed strategy allows to avoid the multipath reflections that appear when continuous waves are used, and it improves the achieved accuracy compared to the original MFCW method. To validate it, an 80 µm square AlScN piezoelectric micromachined ultrasonic transducer (PMUT) was chosen as a transmitter while a hydrophone was utilized as a target and receiver, immersed in fluorinert (FC-70) as a propagation medium. Three independent and consecutive tone-burst signals were transmitted successively. The selected frequencies are f1 = 2.3962 MHz, f2 = 2.327 MHz and f3 = 2.1195 MHz, giving first and second-order resolutions of 6.88 and 0.79 µm/°, respectively. Experimental results show a ±6.2 µm measured range error in a range of 3.5 mm, and therefore it represents a good candidate for ultrasound micro-profilometer applications under liquid operation.

Multielement Ring Array Based on Minute Size PMUTs for High Acoustic Pressure and Tunable Focus Depth.

This paper presents a multielement annular ring ultrasound transducer formed by individual high-frequency PMUTs (17.5 MHz in air and 8.7 MHz in liquid) intended for high-precision axial focalization and high-performance ultrasound imaging. The prototype has five independent multielement rings fabricated by a monolithic process over CMOS, allowing for a very compact and robust design. Crosstalk between rings is under 56 dB, which guarantees an efficient beam focusing on a range between 1.4 mm and 67 µm. The presented PMUT-on-CMOS annular array with an overall diameter down to 669 µm achieves an output pressure in liquid of 4.84 kPa/V/mm2 at 1.5 mm away from the array when the five channels are excited together, which is the largest reported for PMUTs. Pulse-echo experiments towards high-resolution imaging are demonstrated using the central ring as a receiver. With an equivalent diameter of 149 µm, this central ring provides high receiving sensitivity, 441.6 nV/Pa, higher than that of commercial hydrophones with equivalent size. A 1D ultrasound image using two channels is demonstrated, with maximum received signals of 7 mVpp when a nonintegrated amplifier is used, demonstrating the ultrasound imaging capabilities.

Resiliencia. Diferencias entre estudiantes universitarios y jóvenes trabajadores / Resiliene. Differences between Graduate Students and Young Workers / Resiliência. Diferencias entre estudantes universitários e jovens trabalhadores

Resumen Objetivo. Comparar los niveles de resiliencia entre jóvenes universitarios y jóvenes trabajadores, e identificar posibles relaciones de dicha variable con la edad de los participantes. Método. La muestra, de tipo incidental, estuvo conformada por 188 jóvenes, cuya edad oscilaba entre los 18 y los 27 años. Al momento del estudio, 138 cursaban una carrera profesional universitaria y 50 eran trabajadores. Para medir la variable del estudio se utilizó la Escala de Resiliencia traducida y adaptada al español. Resultados. El principal hallazgo es que los jóvenes universitarios obtienen puntajes significativamente mayores que los trabajadores, tanto en el total de la prueba de resiliencia (t (186) = -3.98, p = 0.000, d = 0.65) como en las dos dimensiones que la componen, Competencia personal (t (186) = -4.45, p = 0.000, d = 0.73) y Aceptación de sí mismo y de la vida (t (186) = -2.23, p = 0.026, d = 0.36). Conclusión. Un mayor nivel de estudios, en el caso universitario, es un factor protector ante la adversidad (mayor resiliencia).

Abstract Objective. To compare the levels of resilience between university and young workers, as well as between men and women, and to identify possible relationships of this variable with the age of the participants. Method. This was a correlational study with transversal-correlational design. The sample was incidental and was made up of 188 people between 18 to 27 years old. At the time of the study, 138 of the participants were pursuing an undergraduate major in the university and 50 of them were workers. To measure the study variable, the Resilience Scale was used in its translated and adapted version to Spanish. Results. The main finding is that university students obtain significantly higher scores than workers, both in the total resilience test (t(186)=-3.98, p = 0.000, d=0.65) and in the two dimensions that compose it, Personal competence (t(186)=-4.45, p=0.000, d=0.73) and Acceptance of self and life (t(186)=-2.23, p=0.026, d=0.36) Conclusion. The general conclusion indicates that having a higher level of education, university, is a protective factor in the face of adversity (greater resilience).

Resumo Escopo. Comparar os níveis de resiliência entre jovens universitários e jovens trabalhadores, e identificar possíveis relações desta variável com a idade dos participantes. Metodologia. A amostra, do tipo incidental, esteve conformada por 188 jovens, com idade que oscilava entre os 18 e os 27 anos. Ao momento do estudo, 138 cursavam uma carreira profissional universitária e 50 eram trabalhadores. Para medir a variável do estudo foi utilizada a Escada de Resiliência traduzida e adaptada ao espanhol Resultados. A principal descoberta é que os jovens universitários obtêm pontuações significativamente maiores que os trabalhadores, tanto no total da prova de resiliência (t (186) = -3.98, p = 0.000, d = 0.65) como nas duas dimensões que a compõem, Competência pessoal (t (186) = -4.45, p = 0.000, d = 0.73) e Aceitação de si mesmo e da vida t (186) = -2.23, p = 0.026, d = 0.36). Conclusão. Um maior nível de estudos, no caso universitário, é um fator protetor ante a adversidade (maior resiliência).

Miniaturized 0.13-µm CMOS Front-End Analog for AlN PMUT Arrays.

This paper presents an analog front-end transceiver for an ultrasound imaging system based on a high-voltage (HV) transmitter, a low-noise front-end amplifier (RX), and a complementary-metal-oxide-semiconductor, aluminum nitride, piezoelectric micromachined ultrasonic transducer (CMOS-AlN-PMUT). The system was designed using the 0.13-µm Silterra CMOS process and the MEMS-on-CMOS platform, which allowed for the implementation of an AlN PMUT on top of the CMOS-integrated circuit. The HV transmitter drives a column of six 80-µm-square PMUTs excited with 32 V in order to generate enough acoustic pressure at a 2.1-mm axial distance. On the reception side, another six 80-µm-square PMUT columns convert the received echo into an electric charge that is amplified by the receiver front-end amplifier. A comparative analysis between a voltage front-end amplifier (VA) based on capacitive integration and a charge-sensitive front-end amplifier (CSA) is presented. Electrical and acoustic experiments successfully demonstrated the functionality of the designed low-power analog front-end circuitry, which outperformed a state-of-the art front-end application-specific integrated circuit (ASIC) in terms of power consumption, noise performance, and area.

Predictores de conductas alimentarias de riesgo en estudiantes de bachillerato / Predictors of risk eating behaviors in high school students

Resumen El objetivo principal de este estudio fue identificar variables sociodemográficas y psicosociales capaces de predecir las conductas alimentarias de riesgo (CAR) en estudiantes de bachillerato. Participaron 988 adolescentes (541 mujeres y 447 hombres) de entre 14 y 18 años de edad (M = 16.79, DE = 1.50). Además de las CAR (Atracón-purga, Medidas compensatorias y Restricción), examinadas a través del Cuestionario Breve de Conductas Alimentarias de Riesgo, fueron evaluadas las variables psicosociales siguientes: apoyo familiar y de amigos, ajuste escolar, victimización, ideación suicida, estrés académico, insatisfacción corporal y depresión; finalmente, las variables sociodemográficas incluidas fueron: sexo, edad, horas de sueño al día y horas dedicadas al Internet o las redes sociales. Mediante tres análisis de regresión lineal múltiple, uno para cada CAR (R2 = .36, .16 y .55, respectivamente; todas con p < .001), se pudieron identificar distintas variables predictivas, entre las que destacaron la insatisfacción corporal, la depresión y el sexo (mujeres). La identificación de estas variables puede contribuir a la mejora de las estrategias de prevención en materia de CAR y, por ende, de los trastornos alimentarios entre adolescentes.

Abstract The main objective of this study was to identify sociodemographic and psychosocial variables capable of predicting risk eating behaviors (REB) in high school students. Participants were 988 adolescents (541 women and 447 men) between 14 and 18 years of age (M = 16.79, SD = 1.50). In addition to the REB (Binge-purge, Compensatory behavior and Restriction), examined through the Brief Questionnaire on Risk Food Behaviors, the following psychosocial variables were also evaluated: family and friend support, school adjustment, victimization, suicidal ideation, academic stress, body dissatisfaction and depression; finally, the sociodemographic variables included were: sex, age, hours of sleep per day and hours dedicated to the Internet or social networks. Through three multiple linear regression analyzes, one for each REB (R2 = .36, .16 and .55, respectively; all with p < .001), different predictive variables could be identified, among which stood out the body dissatisfaction, the depression and sex (women). The identification of these variables can contribute to the improvement of prevention strategies in terms of REB and eating disorders among adolescents.

Insatisfacción con la imagen corporal y personalidad en estudiantes de bachillerato de la región Altos Sur de Jalisco, México / Dissatisfaction with body image and personality in high school students of the region Altos Sur de Jalisco, Mexico

El presente estudio se planteó como objetivos identificar el nivel predictivo que tienen las dimensiones de la personalidad sobre la imagen corporal (IC) y sus posibles relaciones, así como comparar dichas variables conforme al sexo de los participantes. La población de estudio fueron alumnos de tres carreras técnicas de una institución de educación pública del estado de Jalisco, México. La muestra estuvo compuesta por 567 alumnos. El instrumento para medir la imagen corporal fue el Cuestionario de Insatisfacción con la Imagen Corporal (Body Shape Questionnaire) y para evaluar la Personalidad, el Inventario de Personalidad NEO Revisado NEO FFI (versión reducida del NEO PI-R). En materia de resultados y mediante un análisis de regresión lineal múltiple se identificaron como variables predictoras de la imagen corporal ­insafisfecha­ la dimensión de la personalidad denominada neuroticismo y el sexo femenino; además, se encontraron relaciones significativas entre las dimensiones de la personalidad neuroticismo, extroversión, amabilidad y responsabilidad con la IC y diferencias significativas en esta última conforme al sexo. Se sugiere que en estudios posteriores se incluyan otras características que pudieran explicar en mayor medida la presencia de Insatisfacción de la Imagen Corporal en adolescentes y se confirme la influencia de las variables predictoras identificadas.

The objectives of this study were to identify the predictive level that personality dimensions have on the students Body Image, as well as their possible relationships, and to compare such variables according to the sex of the participants. The study population were students of three technical careers at a public educational institution in the state of Jalisco, Mexico. The sample consisted of 567 students. The Body Shape Questionnaire was used to measure the Body Image. The Neo Personality Inventory Revised NEO FFI (reduced version of the NEO PI-R) was used to evaluate the personality. Regarding the results, a multiple linear regression analysis identified the predictive variables of the Body Image ­unsatisfied­, the dimension of the personality called "Neuroticism" and the female sex. In addition, significant relationships were found between the dimensions of personality "Neuroticism", "Extroversion", "Kindness and Responsibility" with body image and significant differences in it according to sex. It is suggested that later studies include other characteristics that could explain the presence of Body Image dissatisfaction in adolescents and confirm the influence of the predictor variables identified.

Construcción y Validación de una Escala de Actitudes hacia el Narcotráfico en Estudiantes del Estado de Jalisco / Construction and Validation of a Scale of Attitudes toward Drug Trafficking in Students from the State of Jalisco

Resumen El presente trabajo de investigación tuvo como objetivo construir un instrumento de medida para conocer las actitudes hacia el narcotráfico de estudiantes universitarios y de bachillerato. El instrumento se denominó "Escala de Actitudes hacia el Narcotráfico" y fueron evaluadas sus propiedades psicométricas de validez y confiabilidad a través de un análisis factorial exploratorio y confirmatorio. La muestra estuvo integrada por 2356 estudiantes de ambos niveles educativos. Al finalizar la validación, el instrumento quedó conformado por 17 reactivos y tres factores relacionados: "Rechazo al narcotráfico y los narcotraficantes", "Apoyo al narcotráfico y los narcotraficantes" y "Predisposición de pertenencia al narcotráfico e identificación con la narcocultura", mostrando propiedades psicométricas satisfactorias (α=867). En general, los estudiantes muestran actitudes negativas hacia el narcotráfico, con diferencias según el sexo y el nivel educativo, siendo los hombres y los bachilleres quienes mantienen menor grado de rechazo. Se recomienda aplicar la escala en otras poblaciones y contextos tanto para confirmar las propiedades sus psicométricas como para identificar el rechazo, la aceptación y la predisposición de pertenencia de los individuos hacia dicha actividad y particularmente, para identificar su asociación con otras variables de interés psicosocial.

Abstract The objective of this research work was to build a measurement instrument to know the attitudes toward drug trafficking of university and high school students. The instrument was called the "Scale of Attitudes towards Drug Trafficking" and its psychometric properties of validity and consistency were evaluated through an exploratory and confirmatory factorial analysis. The sample consisted of 2356 students of both educational levels. At the end of the validation process, the instrument was made up of 17 items and three related factors: "Rejection of drug trafficking and drug traffickers", "Support for drug trafficking and drug traffickers" and "Predisposition of belonging to drug trafficking and identification with narcoculture", showing satisfactory psychometric properties (α = 867). In general, students show negative attitudes toward drug trafficking, with differences according to sex and educational level. The men and the high school students maintain lower level of rejection. It is recommended to apply the scale in other populations and contexts to confirm their psychometric properties and identify the rejection, acceptance and predisposition of belonging to drug trafficking, as well as to identify their association with other psychosocial variables of interest.

Molecular architecture of the centriole proteome: the conserved WD40 domain protein POC1 is required for centriole duplication and length control.

Centrioles are intriguing cylindrical organelles composed of triplet microtubules. Proteomic data suggest that a large number of proteins besides tubulin are necessary for the formation and maintenance of a centriole's complex structure. Expansion of the preexisting centriole proteome from the green alga Chlamydomonas reinhardtii revealed additional human disease genes, emphasizing the significance of centrioles in normal human tissue homeostasis. We found that two classes of ciliary disease genes were highly represented among the basal body proteome: cystic kidney disease (especially nephronophthisis) syndromes, including Meckel/Joubert-like and oral-facial-digital syndrome, caused by mutations in CEP290, MKS1, OFD1, and AHI1/Jouberin proteins and cone-rod dystrophy syndrome genes, including UNC-119/HRG4, NPHP4, and RPGR1. We further characterized proteome of the centriole (POC) 1, a highly abundant WD40 domain-containing centriole protein. We found that POC1 is recruited to nascent procentrioles and localizes in a highly asymmetrical pattern in mature centrioles corresponding to sites of basal-body fiber attachment. Knockdown of POC1 in human cells caused a reduction in centriole duplication, whereas overexpression caused the appearance of elongated centriole-like structures. Together, these data suggest that POC1 is involved in early steps of centriole duplication as well as in the later steps of centriole length control.

A mutation in the centriole-associated protein centrin causes genomic instability via increased chromosome loss in Chlamydomonas reinhardtii.

BACKGROUND: The role of centrioles in mitotic spindle function remains unclear. One approach to investigate mitotic centriole function is to ask whether mutation of centriole-associated proteins can cause genomic instability. RESULTS: We addressed the role of the centriole-associated EF-hand protein centrin in genomic stability using a Chlamydomonas reinhardtii centrin mutant that forms acentriolar bipolar spindles and lacks the centrin-based rhizoplast structures that join centrioles to the nucleus. Using a genetic assay for loss of heterozygosity, we found that this centrin mutant showed increased genomic instability compared to wild-type cells, and we determined that the increase in genomic instability was due to a 100-fold increase in chromosome loss rates compared to wild type. Live cell imaging reveals an increased rate in cell death during G1 in haploid cells that is consistent with an elevated rate of chromosome loss, and analysis of cell death versus centriole copy number argues against a role for multipolar spindles in this process. CONCLUSION: The increased chromosome loss rates observed in a centrin mutant that forms acentriolar spindles suggests a role for centrin protein, and possibly centrioles, in mitotic fidelity.

Proteomic analysis of isolated chlamydomonas centrioles reveals orthologs of ciliary-disease genes.

BACKGROUND: The centriole is one of the most enigmatic organelles in the cell. Centrioles are cylindrical, microtubule-based barrels found in the core of the centrosome. Centrioles also act as basal bodies during interphase to nucleate the assembly of cilia and flagella. There are currently only a handful of known centriole proteins. RESULTS: We used mass-spectrometry-based MudPIT (multidimensional protein identification technology) to identify the protein composition of basal bodies (centrioles) isolated from the green alga Chlamydomonas reinhardtii. This analysis detected the majority of known centriole proteins, including centrin, epsilon tubulin, and the cartwheel protein BLD10p. By combining proteomic data with information about gene expression and comparative genomics, we identified 45 cross-validated centriole candidate proteins in two classes. Members of the first class of proteins (BUG1-BUG27) are encoded by genes whose expression correlates with flagellar assembly and which therefore may play a role in ciliogenesis-related functions of basal bodies. Members of the second class (POC1-POC18) are implicated by comparative-genomics and -proteomics studies to be conserved components of the centriole. We confirmed centriolar localization for the human homologs of four candidate proteins. Three of the cross-validated centriole candidate proteins are encoded by orthologs of genes (OFD1, NPHP-4, and PACRG) implicated in mammalian ciliary function and disease, suggesting that oral-facial-digital syndrome and nephronophthisis may involve a dysfunction of centrioles and/or basal bodies. CONCLUSIONS: By analyzing isolated Chlamydomonas basal bodies, we have been able to obtain the first reported proteomic analysis of the centriole.