Simultaneous measurement of orthogonal terahertz fields via an emission multiplexing scheme.

We propose a polarization sensitive terahertz time-domain spectrometer that can record orthogonally polarized terahertz fields simultaneously, using fibre-coupled photoconductive antennas and a scheme that modulated the emitter's polarization. The s and p channels of the multi-pixel terahertz emitter were modulated at different frequencies, thereby allowing orthogonal waveforms to be demultiplexed from the recorded signal in post-processing. The performance of the multi-pixel emitter used in this multiplexing scheme was comparable to that of a commercial single-polarization H-dipole antenna. The approach allowed two orthogonally polarized terahertz pulses to be recorded with good signal to noise (>1000:1) within half a second. We verified the capability of the spectrometer by characterizing a birefringent crystal and by imaging a polarization-sensitive metamaterial. This work has significant potential to improve the speed of terahertz polarization sensitive applications, such as ellipsometry and imaging.

Roadmap on optical sensors.

Optical sensors and sensing technologies are playing a more and more important role in our modern world. From micro-probes to large devices used in such diverse areas like medical diagnosis, defence, monitoring of industrial and environmental conditions, optics can be used in a variety of ways to achieve compact, low cost, stand-off sensing with extreme sensitivity and selectivity. Actually, the challenges to the design and functioning of an optical sensor for a particular application requires intimate knowledge of the optical, material, and environmental properties that can affect its performance. This roadmap on optical sensors addresses different technologies and application areas. It is constituted by twelve contributions authored by world-leading experts, providing insight into the current state-of-the-art and the challenges their respective fields face. Two articles address the area of optical fibre sensors, encompassing both conventional and specialty optical fibres. Several other articles are dedicated to laser-based sensors, micro- and nano-engineered sensors, whispering-gallery mode and plasmonic sensors. The use of optical sensors in chemical, biological and biomedical areas is discussed in some other papers. Different approaches required to satisfy applications at visible, infrared and THz spectral regions are also discussed.

Chameleon: a cloud computing Industry 4.0 neutron spectrum unfolding code.

This work presents Chameleon, a cloud computing (CC) Industry 4.0 (I4) neutron spectrum unfolding code. The code was designed under the Python programming language, using Streamlit framework®, and it is executed on the cloud, as I4 CC technology through internet, by using mobile devices with internet connectivity and a web navigator. In its first version, as a proof of concept, the SPUNIT algorithm was implemented. The main functionalities and the preliminary tests performed to validate the code are presented. Chameleon solves the neutron spectrum unfolding problem and it is easy, friendly and intuitive. It can be applied with success in various workplaces. More validation tests are in progress. Future implementations will include improving the graphical user interface, inserting other algorithms, such as GRAVEL, MAXED and neural networks, and implementing an algorithm to estimate uncertainties in the calculated integral quantities.

Molecular detection of Vibrio paraheamolyticus in a sperm whale (Physeter macrocephalus) stranding in northern Veracruz, Mexico.

On 25 August 2021, a single female sperm whale (Physeter macrocephalus) was found stranded dead in Playa Tuxpan, Veracruz, Mexico. Skin biopsies were obtained and screened for the detection of various potentially pathogenic bacterial genera, using conventional polymerase chain reaction and sequencing of the positive amplicons. We recorded, for the first time, the presence of Vibrio paraheamolyticus in skin samples from P. macrocephalus in the Gulf of Mexico. Additionally, we discuss 29 records reporting strandings of sperm whales from six states of the Mexican Republic. Most of the records are concentrated in the Pacific Ocean. Our findings increase the inventory of bacteria reported in P. macrocephalus worldwide, summarising the knowledge of stranding events in sperm whale populations in Mexico.

Simulated and Experimental Verification for a Terahertz Specific Finite Rate of Innovation Signal Processing Method.

Recently, finite rate of innovation methods have been successfully applied to achieve low sampling rates in many areas, such as for ultrasound and radio signals. However, to the best of our knowledge, there are no journal publications applying this to real terahertz signals. In this work, we mathematically describe a finite rate of innovation method applied specifically to terahertz signals both experimentally and in simulation. To demonstrate our method, we applied it to randomized simulated signals with and without the presence of noise and to simple experimental measurements. We found excellent agreement between the simulated signals and those recreated based on results from our method, with this success also being replicated experimentally. These results were obtained at relatively low sampling rates, compared to standard methods, which is a key advantage to using a finite rate of innovation method as it allows for faster data acquisition and signal processing.

Monitoring the Effect of Transdermal Drug Delivery Patches on the Skin Using Terahertz Sensing.

Water content of the skin is an important parameter for controlling the penetration rate of chemicals through the skin barrier; therefore, for transdermal patches designed for drug delivery to be successful, the effects of the patches on the water content of the skin must be understood. Terahertz (THz) spectroscopy is a technique which is being increasingly investigated for biomedical applications due to its high sensitivity to water content and non-ionizing nature. In this study, we used THz measurements of the skin (in vivo) to observe the effect of partially and fully occlusive skin patches on the THz response of the skin after the patches had been applied for 24 h. We were able to observe an increase in the water content of the skin following the application of the patches and to identify that the skin remained hyper-hydrated for four hours after the removal of the fully occlusive patches. Herein, we show that THz spectroscopy has potential for increasing the understanding of how transdermal patches affect the skin, how long the skin takes to recover following patch removal, and what implications these factors might have for how transdermal drug patches are designed and used.

Estructura poblacional del árbol Avicennia germinans (Acanthaceae) en un manglar alterado del Golfo de México / Population structure of Avicennia germinans trees (Acanthaceae) in a disturbed mangrove in the Gulf of Mexico

Resumen Introducción: Los manglares están en declive en el mundo, conocer su estructura y regeneración en diferentes niveles de alteración puede ayudar a comprender la dinámica poblacional ante situaciones de estrés. Objetivo: La meta principal del estudio fue analizar la estructura comunitaria y estimar la trayectoria de las poblaciones de Avicenia germinans en diferentes sitios de manglar que presentan tres niveles de alteración. Métodos: Ocho transectos de aproximadamente 500 m de largo y colocados de manera perpendicular a la laguna de Tampamachoco, Veracruz, interceptaron tres niveles de alteración en los sitios estudiados del bosque de manglar. En cada transecto, cuadrantes de 10 x 10 m, 5 x 5 m, y 1 x 1 m sirvieron para contar todos los árboles de mangle por especie y estadio de madurez en 2017 y 2018. Resultados: La especie más abundante fue: A. germinans seguida de Rhizophora mangle y Laguncularia racemosa. Con base en su abundancia, se encontraron diferencias significativas según los tres grados de alteración (AM R = 0.6, P < 0.001), ilustrado en un análisis de ordenación no métrico (nMDS). Una tabla de vida para A. germinans permitió un análisis poblacional que mostró una tasa intrínseca de incremento poblacional (r) negativa para los sitios que presentan alteración (-0.0027 u -0.0774) y positiva (0.0289) en el sitio sin alteración aparente. La supervivencia del estadio de plántula a juvenil varia de 50 % en el sitio no alterados a 5 y 4 % en los otros dos sitios. Conclusiones: Se necesitan medidas para incrementar la sobrevivencia de las plántulas y revertir la disminución de las trayectorias en los sitios con alteración, de otra forma el manglar tendrá una viabilidad reducida en el término medio.

Abstract Introduction: Globally, mangroves are declining; characterizing their structure and regeneration at different disturbance levels can help understand their responses to stressful situations. Objective: The study's primary goal was to analyze the mangrove community structure and to estimate the populations' trajectories of Avicenia germinans at different mangrove sites that present three levels of disturbance. Methods: Eight transects of approximately 500 m in length and laid perpendicular to the Tamapamchoco lagoon, Veracruz, intersected three levels of disturbance currently present on the mangrove forest. On each transect, 10 x 10 m, 5 x 5 m, and 1 x 1 m quadrants served to account for all mangrove trees by species and stage of maturity in 2017 and 2018. Results: The most abundant species was: A. germinans followed by Rhizophora mangle and Laguncularia racemosa. Based on their abundance, we found significant differences for the three levels of disturbance (ANOSIM R = 0.6, P < 0.001) presented in a non-metric ordination (nMDS). A life table for A. germinans allowed a population analysis that showed an intrinsic rate of population increase (r) that was negative at the disturbed sites (-0.0027 and -0.0774) and positive (0.0289) at the apparently undisturbed site. Seedling to juvenile stage survival ranged from 50 % at the undisturbed site to 5 and 4 % at the disturbed sites. Conclusions: Measures to increase the survival of seedlings are necessary to reverse the decreasing population trajectories at the disturbed sites; otherwise, the mangrove will have reduced viability in the medium term.

OUTCOME OF NON-SURGICAL TREATMENT OF MALLET FINGER.

OBJECTIVE: To establish the association between initial and residual angulation of the distal interphalangeal joint (DIJ) in mallet finger treated conservatively. METHODS: An observational, prospective, descriptive and analytical research developed with uncomplicated closed mallet finger patients between January and December 2017. A total of two measurements of the DIJ were done, at the initial trauma and 6 weeks after conservative treatment. All measurements were ranked according to the Crawford Classification and Relative Risk was measured. RESULTS: In total, 43 patients were studied, in which 53.48% of outcomes obtained were excellent. The sample was divided in two groups; one with less than 30º of DIJ initial angulation, which had 28% of residual angulation. The second group with more than 30º presented 72.22% of residual angulation. The Relative Risk to present a residual angulation in patients that had 30º of DIJ initial angulation was 2.99 (CI 95%) with p = 0.0059. CONCLUSION: It is suggested that patients with an initial DIJ angulation more than 30º are more likely to present residual angulation with conservative treatment. Level of Evidence IV, Case series.

OBJETIVO: Estabelecer a associação entre a angulação inicial e residual da articulação interfalângica distal em casos de dedo em martelo tratados de forma conservadora. MÉTODOS: Estudo observacional, prospectivo, descritivo e analítico desenvolvido com pacientes que apresentavam dedo em martelo fechado, sem complicações, no período de janeiro a dezembro de 2017. Foram realizadas duas medidas na articulação interfalângica distal, no trauma inicial e seis semanas após o tratamento conservador. Todos foram classificados de acordo com a Classificação Crawford e o Risco Relativo (RR) foi calculado. RESULTADOS: Foram estudados 43 pacientes, dos quais 53,48% apresentaram resultados excelentes. A amostra foi dividida em dois grupos: um com < 30º de angulação interfalângica distal inicial, com 28% de angulação residual, e outro com > 30º, apresentando 72,22% de angulação residual. O risco relativo de apresentar angulação residual em pacientes com 30º de angulação inicial da articulação interfalângica distal foi de 2,99 (IC 95%) com um valor de p = 0,0059. CONCLUSÃO: Sugere-se que os pacientes com angulação inicial da articulação interfalângica distal superior a 30º têm maior probabilidade de apresentar angulação residual com tratamento conservador. Nível de Evidência IV, Série de casos.

Outcome of non-surgical treatment of mallet finger / Resultado do tratamento não cirúrgico do dedo em martelo

ABSTRACT Objective: To establish the association between initial and residual angulation of the distal interphalangeal joint (DIJ) in mallet finger treated conservatively. Methods: An observational, prospective, descriptive and analytical research developed with uncomplicated closed mallet finger patients between January and December 2017. A total of two measurements of the DIJ were done, at the initial trauma and 6 weeks after conservative treatment. All measurements were ranked according to the Crawford Classification and Relative Risk was measured. Results: In total, 43 patients were studied, in which 53.48% of outcomes obtained were excellent. The sample was divided in two groups; one with less than 30º of DIJ initial angulation, which had 28% of residual angulation. The second group with more than 30º presented 72.22% of residual angulation. The Relative Risk to present a residual angulation in patients that had 30º of DIJ initial angulation was 2.99 (CI 95%) with p = 0.0059. Conclusion: It is suggested that patients with an initial DIJ angulation more than 30º are more likely to present residual angulation with conservative treatment. Level of Evidence IV, Case series.

RESUMO Objetivo: Estabelecer a associação entre a angulação inicial e residual da articulação interfalângica distal em casos de dedo em martelo tratados de forma conservadora. Métodos: Estudo observacional, prospectivo, descritivo e analítico desenvolvido com pacientes que apresentavam dedo em martelo fechado, sem complicações, no período de janeiro a dezembro de 2017. Foram realizadas duas medidas na articulação interfalângica distal, no trauma inicial e seis semanas após o tratamento conservador. Todos foram classificados de acordo com a Classificação Crawford e o Risco Relativo (RR) foi calculado. Resultados: Foram estudados 43 pacientes, dos quais 53,48% apresentaram resultados excelentes. A amostra foi dividida em dois grupos: um com < 30º de angulação interfalângica distal inicial, com 28% de angulação residual, e outro com > 30º, apresentando 72,22% de angulação residual. O risco relativo de apresentar angulação residual em pacientes com 30º de angulação inicial da articulação interfalângica distal foi de 2,99 (IC 95%) com um valor de p = 0,0059. Conclusão: Sugere-se que os pacientes com angulação inicial da articulação interfalângica distal superior a 30º têm maior probabilidade de apresentar angulação residual com tratamento conservador. Nível de Evidência IV, Série de casos.

[Concentration of Hg, Pb, Cd, Cr and As in liver Carcharhinus limbatus (Carcharhiniformes: Carcharhinidae) captured in Veracruz, Mexico]. / Concentración de Hg, Pb, Cd, Cr y As en hígado de Carcharhinus limbatus (Carcharhiniformes: Carcharhinidae) capturado en Veracruz, México.

Pollution by heavy metals in marine ecosystems in the Gulf of Mexico is one of the hardest conservation issues to solve. Sharks as top predators are bioindicators of the marine ecosystem health, since they tend to bioaccumulate and biomagnify contaminants; they also represent a food source for local consumption. Thus, the objective of this study was to study the possible presence of heavy metals and a metalloid in livers of Carcharhinus limbatus. For this, a total of 19 shark livers were taken from animals captured nearby Tamihua, Veracruz, Mexico from December 2007 to April 2008. 12 out of the 19 captured sharks were males, one was an adult female, three were juvenile males, and three juvenile females. Four heavy metals (Hg, Pb, Cd, and Cr) and one metaloid (As) were analyzed in shark livers using an atomic absorption spectrophotometry with flame and hydride generator. Our results showed that the maximum concentrations found were: Hg = 0.69 mg/kg, Cd = 0.43 mg/kg, As = 27.37 mg/kg, Cr = 0.70 mg/kg. The minimum concentrations found were: As = 14.91 mg/kg, Cr = 0.35 mg/kg. The Pb could not be determined because the samples did not have the spectrophotometer minimum detectable amount (0.1 mg/kg). None of the 19 samples analyzed showed above the permissible limits established by Mexican and American laws. There was a correlation between shark size and Cr and As concentration (Pearson test). The concentration of Cr and As was observed to be higher in bigger animals. There was not a significant difference in heavy metals concentration between juveniles and adults; however, there was a difference between males and females. A higher Cr concentration was found in females when compared to males. None of the samples exceed the maximum limit established by the laws of Mexico and the United States of America. Much longer studies are needed with C. limbatus and other species caught in the region, in order to determine the degree of contaminants exposure in aquatic ecosystems and to identify potential health risks to consumers.

Concentración de Hg, Pb, Cd, Cr y As en hígado de Carcharhinus limbatus (Carcharhiniformes: Carcharhinidae) capturado en Veracruz, México

Concentration of Hg, Pb, Cd, Cr and As in liver Carcharhinus limbatus (Carcharhiniformes: Carcharhinidae) captured in Veracruz, Mexico. Pollution by heavy metals in marine ecosystems in the Gulf of Mexico is one of the hardest conservation issues to solve. Sharks as top predators are bioindicators of the marine ecosystem health, since they tend to bioaccumulate and biomagnify contaminants; they also represent a food source for local consumption. Thus, the objective of this study was to study the possible presence of heavy metals and a metalloid in livers of Carcharhinus limbatus. For this, a total of 19 shark livers were taken from animals captured nearby Tamihua, Veracruz, Mexico from December 2007 to April 2008. 12 out of the 19 captured sharks were males, one was an adult female, three were juvenile males, and three juvenile females. Four heavy metals (Hg, Pb, Cd, and Cr) and one metaloid (As) were analyzed in shark livers using an atomic absorption spectrophotometry with flame and hydride generator. Our results showed that the maximum concentrations found were: Hg=0.69mg/kg, Cd=0.43mg/kg, As=27.37mg/kg, Cr=0.70mg/kg. The minimum concentrations found were: As=14.91mg/kg, Cr=0.35mg/kg. The Pb could not be determined because the samples did not have the spectrophotometer minimum detectable amount (0.1mg/kg). None of the 19 samples analyzed showed above the permissible limits established by Mexican and American laws. There was a correlation between shark size and Cr and As concentration (Pearson test). The concentration of Cr and As was observed to be higher in bigger animals. There was not a significant difference in heavy metals concentration between juveniles and adults; however, there was a difference between males and females. A higher Cr concentration was found in females when compared to males. None of the samples exceed the maximum limit established by the laws of Mexico and the United States of America. Much longer studies are needed with C. limbatus and other species caught in the region, in order to determine the degree of contaminants exposure in aquatic ecosystems and to identify potential health risks to consumers.

La contaminación de los ecosistemas marinos y costeros por metales pesados en el Golfo de México es uno de los problemas que afectan a los recursos naturales del medio acuático. Los tiburones por situarse en niveles tróficos superiores de la red alimenticia acumulan y magnifican cantidades considerables de contaminantes. Por esta razón, el objetivo de este trabajo fue determinar la concentración de cuatro metales pesados (Hg, Cd, Pb y Cr) y un metaloide (As) en el tiburón punta negra (Carcharhinus limbatus) por medio de espectrofotometría de absorción atómica con flama y generador de hidruros. Se muestrearon 19 hígados de tiburones capturados cerca de Tamiahua, Veracruz entre noviembre 2007 y marzo 2008, de los cuales 12 fueron machos adultos, una hembra adulta, tres machos jóvenes y tres hembras jóvenes. Las concentraciones máximas registradas para cada metal fueron: Hg=0.69mg/ kg, Cd=0.43mg/kg, As=27.37mg/kg, Cr=0.35mg/kg. El Pb no fue detectado, no al menos la cantidad mínima de detección requerida por el espectrofotómetro de absorción atómica (0.1mg/kg). Ninguna de las muestras analizadas rebasó los límites máximos permisibles por las leyes mexicanas y americanas.

A wireless sensor network for vineyard monitoring that uses image processing.

The first step to detect when a vineyard has any type of deficiency, pest or disease is to observe its stems, its grapes and/or its leaves. To place a sensor in each leaf of every vineyard is obviously not feasible in terms of cost and deployment. We should thus look for new methods to detect these symptoms precisely and economically. In this paper, we present a wireless sensor network where each sensor node takes images from the field and internally uses image processing techniques to detect any unusual status in the leaves. This symptom could be caused by a deficiency, pest, disease or other harmful agent. When it is detected, the sensor node sends a message to a sink node through the wireless sensor network in order to notify the problem to the farmer. The wireless sensor uses the IEEE 802.11 a/b/g/n standard, which allows connections from large distances in open air. This paper describes the wireless sensor network design, the wireless sensor deployment, how the node processes the images in order to monitor the vineyard, and the sensor network traffic obtained from a test bed performed in a flat vineyard in Spain. Although the system is not able to distinguish between deficiency, pest, disease or other harmful agents, a symptoms image database and a neuronal network could be added in order learn from the experience and provide an accurate problem diagnosis.

Valores y factores sociodemográficos en estudiantes universitarios: un estudio comparativo / Values and socio demographic- factors in university students: a comparative study / Valores e fatores sócio-demográficos nos estudantes universitários: um estudo comparativo

El objetivo de este trabajo fue comparar los valores de los estudiantes de una institución universitaria en función de las variables socio demográficas género, procedencia (colegio: privado - público y religioso - no religioso), religión (católica - no católica) y edad. Para la investigación se diseñó una escala autoaplicada de 55 valores, que se administró mediante una selección intencional a 3.384 estudiantes. De la escala de valores se derivaron cinco dimensiones: Cosmopolitas, Sociales, Instrumentales, Morales y Conservadores. Los resultados indicaron que las mujeres presentaron mayor valoración de las dimensiones valores Morales, Sociales y Conservadores, mientras que los hombres valoraron más la dimensión Cosmopolitas. Los estudiantes provenientes de colegios religiosos valoraron más la dimensión valores Conservadores. La variable socio demográfica de mayor influencia en las preferencias axiológicas fue el género y la dimensión de valores diferenciada por mayor cantidad de los factores socio demográficos evaluados fue aquella representada por valores conservadores.

The purpose of this study was to compare the values of university students as a function of socio-demographic variables such as: gender, kind of school (religious vs. non-religious; private vs. public), religion (Catholic - Non Catholic) and age. A self-administered scale of 55 values was designed for this research and it was used with a sample of 3.384 students selected intentionally. The values scale showed five dimensions: Cosmopolitan, Social, Instrumental, Moral and Conservative. Results indicated that women presented a higher appreciation of Moral, Social and Conservative values, whereas men valued more the Cosmopolitan values. The students that attended religious schools valued more the Conservative dimension. The socio demographic variable of major influence in the axiological preferences was gender and the value dimension differentiated by most socio-demographic factors was the Conservative.

Neste artigo comparam-se os valores dos estudantes de uma instituição universitária em função das variáveis sócio-demográficas género, procedência (colégio, privado, público; religioso, no religioso) e idade. Desenhou-se uma escala auto-aplicada de 55 valores, administrada a uma seleção intencional de 3.384 estudantes. Da escala de valores, determinaram-se cinco valores: Cosmopolitas, Sociais, Instrumentais, Morais e Conservadores. Os resultados revelaram que as mulheres mostraram maiores valorações nas dimensões Morais, Sociais e Conservadores, em quanto os homens valoraram mais a dimensão Cosmopolitas. Os estudantes provenientes de colégios religiosos valoraram mais a dimensão Conservadores. A variável sócio-demográfica de maior influencia nas preferências axiológicas foi o gênero; a dimensão de valores diferenciada por maior quantidade dos fatores sócio-demográficos avaliados foi Conservadores.

Antimasking aspects of harp seal (Pagophilus groenlandicus) underwater vocalizations.

Underwater sounds are very important in social communication of harp seals (Pagophilus groenlandicus) because they are the main means of long- and short-distance communication. Individual harp seals must try to avoid being masked and emit only those calls that will benefit them. Underwater vocalizations of harp seals were recorded during the breeding season. The physical characteristics associated with antimasking attributes of 16 call types were examined. Rising frequency or increasing amplitude within calls were not common. Most of the calls ended abruptly (range 145-966 dB/s), but call onset was more gradual. At high calling rates (95.1-135 calls/min) there were significantly more calls overlapping temporally than at medium (75.1-95 calls/min) or low (35-75 calls/min) calling rates, but even at the highest calling rates, 79.1% of the calls were not overlapped. When 2, 3, or 4 calls overlapped, there were significantly fewer frequency separations of less than 1/3 octave than would be expected by chance. This is important because sounds that are separated by less than 1/3 octave likely mask each other. When 2-4 calls are occurring simultaneously, only 4.5% to 14.2% are masked by virtue of being within 1/3 octave from their nearest neighbor. None of the overlappping calls was of the same type. This suggests that the seals are actively listening to each other's calls and are not randomly using the different call types. Harp seals use frequency and temporal separation in conjunction with a wide vocal repertoire to avoid masking each other.