Hands-On Photonic Education Kits: empowering the integrated photonics workforce through practical training.

The Hands-On Photonic Education (HOPE) Kits, developed with AIM Photonics, address the need for skilled workers in integrated photonics. This paper highlights the role of the HOPE Kits in advancing the training ecosystem and bridging the skills gap. The kits include fully packaged photonic integrated circuits (PICs), enabling instructors to educate and train students on PIC testing and characterization. Covering a wide range of devices and circuits, from waveguides to wavelength division multiplexing for data communication, the kits offer a hands-on experience. Engaging with actual PICs, students gain practical insights, enhancing their understanding of key principles, and preparing them for real-world skill sets in integrated photonics.

Fiber array to chip attach using laser fusion splicing for low loss.

With the ever-increasing need for higher data rates, datacom and telecom industries are now migrating to silicon photonics to achieve higher data rates with reduced manufacturing costs. However, the optical packaging of integrated photonic devices with multiple I/O ports remains a slow and expensive process. We introduce an optical packaging technique to attach fiber arrays to a photonic chip in a single shot using CO2 laser fusion splicing. We show a minimum coupling loss of 1.1 dB, 1.5 dB, and 1.4 dB per-facet for 2, 4, and 8-fiber arrays (respectively) fused to the oxide mode converters using a single shot from the CO2 laser.

Nematode predatory ability of the fungus Duddingtonia flagrans affected by in vitro sequential exposure to ovine gastrointestinal tract.

Duddingtonia flagrans is a nematophagous fungus employed as a biocontrol agent of gastrointestinal nematodes in ruminants. After oral ingestion and passage through the digestive tract of animals, this microorganism captures the nematodes in the feces. The drastic conditions of ruminant digestive tract could affect fungi chlamydospores and therefore biocontrol activity. The aim of this study was to evaluate in vitro the effect of four ruminant digestive segments on the concentration and nematode predatory ability of a Colombian native strain of D. flagrans. The sequential four-step methodology proposed evaluated conditions of the oral cavity, rumen, abomasum, and small intestine such as pH (2, 6, 8), enzymes (pepsin, pancreatin), temperature (39 °C), and anaerobiosis comparing short (7 h) and long (51 h) exposure times. The results showed that the nematode predatory ability of the fungi is affected by sequential exposure to gastrointestinal segments and this effect depends on the exposure time to those conditions. After short exposure (7 h) through the four ruminant digestive segments, the fungi had a nematode predatory ability of 62%, in contrast, after long exposure (51 h) the nematode predatory ability was lost (0%). Moreover, the number of broken chlamydospores was higher in the long-exposure assay.

The Advance of Fusarium Wilt Tropical Race 4 in Musaceae of Latin America and the Caribbean: Current Situation.

The fungus Fusarium oxysporum f. sp. cubense tropical race 4 (syn. Fusarium odoratissimum) (Foc TR4) causes vascular wilt in Musaceae plants and is considered the most lethal for these crops. In Latin America and the Caribbean (LAC), it was reported for the first time in Colombia (2019), later in Peru (2021), and recently declared in Venezuela (2023). This work aimed to analyze the evolution of Foc TR4 in Musaceae in LAC between 2018 and 2022. This perspective contains a selection of topics related to Foc TR4 in LAC that address and describe (i) the threat of Foc TR4 in LAC, (ii) a bibliometric analysis of the scientific production of Foc TR4 in LAC, (iii) the current situation of Foc TR4 in Colombia, Peru, and Venezuela, (iv) medium-term prospects in LAC member countries, and (v) export trade and local food security. In this study, the presence of Foc TR4 in Venezuela and the possible consequences of the production of Musaceae in the long term were reported for the first time. In conclusion, TR4 is a major threat to banana production in Latin America and the world, and it is important to take measures to control the spread of the fungus and minimize its impact on the banana industry. It is important to keep working on the control of Foc TR4, which requires the participation of the local and international industry, researchers, and consumers, among others, to prevent the disappearance of bananas.

Enhanced on-chip frequency measurement using weak value amplification.

We present an integrated design to sensitively measure changes in optical frequency using weak value amplification with a multi-mode interferometer. The technique involves introducing a weak perturbation to the system and then post-selecting the data in such a way that the signal is amplified without amplifying the technical noise, as has previously been demonstrated in a free-space setup. We demonstrate the advantages of a Bragg grating with two band gaps for obtaining simultaneous, stable high transmission and high dispersion. The device is more robust and easily scalable than the free-space implementation, and provides amplified sensitivity compared to other methods of measuring changes in optical frequency on a chip, such as an integrated Mach-Zehnder interferometer.

Electrically induced adiabatic frequency conversion in an integrated lithium niobate ring resonator.

Changing the frequency of light outside the laser cavity is essential for an integrated photonics platform, especially when the optical frequency of the on-chip light source is fixed or challenging to be tuned precisely. Previous on-chip frequency conversion demonstrations of multiple GHz have limitations of tuning the shifted frequency continuously. To achieve continuous on-chip optical frequency conversion, we electrically tune a lithium niobate ring resonator to induce adiabatic frequency conversion. In this work, frequency shifts of up to 14.3 GHz are achieved by adjusting the voltage of an RF control. With this technique, we can dynamically control light in a cavity within its photon lifetime by tuning the refractive index of the ring resonator electrically.

Effectiveness, safety and implementation results of the strategies aimed at the safe prescription of medications in university hospitals in adult patients. Systematic review / Efectividad, seguridad y resultados de implementación de estrategias dirigidas al proceso de prescripción segura de medicamentos en hospitales universitarios en pacientes adultos. Revisión sistemática

Abstract Introduction A broad range of practices aimed at improving the effectives and safety of this process have been documented over the past few years. Objective To establish the effectiveness, safety and results of the implementation of these strategies in adult patients in university hospitals. Methodology A review of systematic reviews was conducted, in addition to a database search in the Cochrane Library of Systematic Reviews, Embase, Epistemonikos, LILACS and gray literature. Any strategy aimed at reducing prescription-associated risks was included as intervention. This review followed the protocol registered in the International Prospective Registry of Systematic Reviews (PROSPERO): CRD42020165143. Results 7,637 studies were identified, upon deleting duplicate references. After excluding records based on titles and abstracts, 111 full texts were assessed for eligibility. Fifteen studies were included in the review. Several interventions grouped into 5 strategies addressed to the prescription process were identified; the use of computerized medical order entry systems (CPOE), whether integrated or not with computerized decision support systems (CDSS), was the most effective approach. Conclusions The beneficial effects of the interventions intended to the prescription process in terms of efficacy were identified; however, safety and implementation results were not thoroughly assessed. The heterogeneity of the studies and the low quality of the reviews, preclude a meta-analysis.

Resumen Introducción En los últimos años se han documentado gran variedad de prácticas dirigidas a mejorar la efectividad y la seguridad de este proceso. Objetivo Establecer la efectividad, seguridad y resultados de implementación de estas estrategias en pacientes adultos en hospitales universitarios. Metodología Se realizó una revisión de revisiones sistemáticas. Igualmente, la búsqueda en las bases de datos de la Biblioteca Cochrane de Revisiones Sistemáticas, Medline, Embase, Epistemonikos, LILACS y literatura gris. Se incluyó como intervención cualquier estrategia dirigida a reducir el riesgo asociado a un error de prescripción. Esta revisión siguió el protocolo registrado en el Registro Prospectivo Internacional de Revisiones Sistemáticas (PROSPERO): CRD42020165143. Resultados Se identificaron 7.637 estudios después de eliminar las referencias duplicadas. Después de la exclusión de registros basados en títulos y resúmenes, se evaluaron 111 textos completos para elegibilidad. Se incluyeron quince estudios en la revisión. Se identificaron varias intervenciones agrupadas en 5 estrategias dirigidas al proceso de prescripción, de las cuales el uso de sistemas computarizados de entrada de órdenes médicas (CPOE) integrados o no a sistemas de soporte de decisión computarizados (CDSS) la estrategia más eficaz. Conclusiones Se identificaron efectos benéficos de las intervenciones dirigidas al proceso de prescripción en términos de eficacia; sin embargo, la seguridad y los resultados de implementación no fueron ampliamente evaluados. La heterogeneidad de los estudios y la baja calidad de las revisiones impiden la realización de un metaanálisis.

Enhanced on-chip phase measurement by inverse weak value amplification.

Optical interferometry plays an essential role in precision metrology such as in gravitational wave detection, gyroscopes, and environmental sensing. Weak value amplification enables reaching the shot-noise-limit of sensitivity, which is difficult for most optical sensors, by amplifying the interferometric signal without amplifying certain technical noises. We implement a generalized form of weak value amplification on an integrated photonic platform with a multi-mode interferometer. Our results pave the way for a more sensitive, robust, and compact platform for measuring phase, which can be adapted to fields such as coherent communications and the quantum domain. In this work, we show a 7 dB signal enhancement in our weak value device over a standard Mach-Zehnder interferometer with equal detected optical power, as well as frequency measurements with 2 kHz sensitivity by adding a ring resonator.

Anthelmintic effect of four extracts obtained from Caesalpinia coriaria foliage against the eggs and larvae of Haemonchus contortus.

To investigate the in vitro anthelmintic efficacy of dividivi (Caesalpinia coriaria), a traditional medicinal plant used in Central America and the northern part of South America, extracts from the foliage of this plant were subjected to the egg hatching test (EHT) and larval exsheathment inhibition test (LEIT), against Haemonchus contortus. Four different extracts were evaluated: acetone-water (AW), methanol-water (MW), acetone-water-dichloromethane (AWD) and methanol-water-dichloromethane (MWD). The concentrations used for the EHT and LEIT tests ranged from 500 to 4000 µg mL-1 and six repetitions per concentration. The effective concentrations (EC50) were calculated using Probit analysis. The EC50 for EHT were 2947.0, 3347.0, 3959.6 and 4538.7 µg mL-1 for MWD, MW, AW and AWD, respectively. The EC50 for LEIT were 2883.4, 5927.4, 9876.3 and 9955.4 µg mL-1 for AWD, AW, MWD and MW, respectively. The methanol extracts were the most effective in inhibiting the hatching of eggs, while the acetone extracts showed efficacy in inhibiting larval exsheathment. This study explains the importance that C. coriaria has as a medicinal plant in Central and South American countries.

Anthelmintic effect of four extracts obtained from Caesalpinia coriaria foliage against the eggs and larvae of Haemonchus contortus / Efeito anti-helmíntico de quatro extratos obtidos da folha de Caesalpinia coriaria contra ovos e larvas de Haemonchus contortus

Abstract To investigate the in vitro anthelmintic efficacy of dividivi (Caesalpinia coriaria), a traditional medicinal plant used in Central America and the northern part of South America, extracts from the foliage of this plant were subjected to the egg hatching test (EHT) and larval exsheathment inhibition test (LEIT), against Haemonchus contortus. Four different extracts were evaluated: acetone-water (AW), methanol-water (MW), acetone-water-dichloromethane (AWD) and methanol-water-dichloromethane (MWD). The concentrations used for the EHT and LEIT tests ranged from 500 to 4000 µg mL-1 and six repetitions per concentration. The effective concentrations (EC50) were calculated using Probit analysis. The EC50 for EHT were 2947.0, 3347.0, 3959.6 and 4538.7 µg mL-1 for MWD, MW, AW and AWD, respectively. The EC50 for LEIT were 2883.4, 5927.4, 9876.3 and 9955.4 µg mL-1 for AWD, AW, MWD and MW, respectively. The methanol extracts were the most effective in inhibiting the hatching of eggs, while the acetone extracts showed efficacy in inhibiting larval exsheathment. This study explains the importance that C. coriaria has as a medicinal plant in Central and South American countries.

Resumo Para investigar a eficácia anti-helmíntica de Divi-divi (Caesalpinia coriaria), uma planta medicinal tradicional usada na América Central e no norte da América do Sul. Extratos das folhas dessa planta foram utilizados em testes in vitro de inibição da eclosão de ovos (EHT) e desembainhamento larvar (LEIT) de Haemonchus contortus. Quatro diferentes extratos foram avaliados: acetona-água (AW), metanol-água (MW), acetona-água-diclorometano (AWD) e metanol-água-diclorometano (MWD). Para os testes EHT e LEIT, as concentrações utilizadas variaram de 500 a 4000 µg mL-1, em seis repetições por concentração. As concentrações efetivas (EC50) foram calculadas, usando-se a análise Probit. A EC50 para EHT foram 2947,0; 3347,0; 3959,6 e 4538,7 µg mL-1 para MWD, MW, AW e AWD, respectivamente. As EC50 para LEIT foram 2883,4; 5927,4; 9876,3 e 9955,4 µg mL-1 para AWD, AW, MWD e MW, respectivamente. Os extratos de metanol foram os mais eficazes em inibir a eclosão de ovos, enquanto os extratos de acetona mostraram-se eficazes em inibir a desembainhamento larvar. Este estudo ajuda a explicar a importância da C. coriaria como planta medicinal nos países da América Central e América do Sul.

Mathematical modeling of the effects of atmospheric pressure on mosquito (Díptera: Culicidae) population density in Villa Clara, Cuba / Modelación matemática del efecto de la presión atmosférica sobre la densidad poblacional de los mosquitos (Diptera: Culicidae) en Villa Clara, Cuba

Abstract Introduction: Mosquitoes (Diptera: Culicidae) are considered one of the most versatile organisms in the world as they can breed in any pool of water, such as puddles or tanks. However, their reproduction is influenced by atmospheric variables that allow predicting their population density. Objective: To assess the impact of atmospheric pressure on mosquito population density in the province of Villa Clara, Cuba, by means of a mathematical model based on a regressive objective regression (ROR) methodology. Materials and methods: The development of the mathematical model to predict breeding sites was based on the number of breeding sites reported in the province of Villa Clara between 2000 and 2017, and the ROR model. Furthermore, a regression analysis was carried out using the IBM SPSS® version 19.0, which allowed obtaining models that explained 100% of the variance, with its corresponding standard error. Results: With respect to the number of breeding sites, an increasing trend was observed in the municipality of Cifuentes, while the trend was downward in Ranchuelo and Caibarién. The municipalities of Santa Clara and Encrucijada had the highest and lowest standard deviation (13.432 vs. 5.968, respectively), which demonstrates great variability among the data of each municipality. Conclusions: There is a close relationship between atmospheric pressure and mosquito population density since both total and specific larval densities increase as atmospheric pressure increases.

Resumen Introducción. Los mosquitos (Diptera: Culicidae) son uno de los organismos más versátiles del mundo, pues pueden reproducirse en cualquier depósito de agua, como charcos o tanques. Sin embargo, su reproducción está influenciada por variables atmosféricas que permiten predecir su densidad poblacional. Objetivo. Evaluar el impacto de la presión atmosférica en la densidad poblacional de mosquitos en la provincia de Villa Clara, Cuba, mediante el uso de modelos matemáticos basados en la metodología de regresión objetiva regresiva (ROR). Materiales y métodos. El desarrollo del modelo matemático de pronóstico de focos de reproducción se basó en el número de focos reportados en la provincia de Villa Clara entre 2000 y 2017, y en el modelo ROR. Además, se realizó un análisis de regresión mediante el programa IBM SPSS® versión 19.0, lo que permitió obtener modelos de regresión que explicaron el 100% de la varianza, con su error típico. Resultados. Respecto a la cantidad de focos, se observó una tendencia al aumento en el municipio de Cifuentes, mientras que en Ranchuelo y Caibarién la tendencia fue a la reducción. Los municipios de Santa Clara y Encrucijada tuvieron la desviación estándar más alta y más baja, respectivamente (134.32 vs. 5.968), lo que evidencia una gran variabilidad entre los datos de cada municipio. Conclusiones. Existe una estrecha relación entre la presión atmosférica y la densidad poblacional de mosquitos, ya que a medida que aumenta la presión atmosférica, aumentan las densidades larvales, tanto total como específicas.

In Vitro Anthelmintic Evaluation of Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce: Fingerprint Analysis of Extracts by UHPLC-Orbitrap Mass Spectrometry.

In the present work, the anthelmintic activity (AA) of ethanolic extracts obtained from Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce was evaluated using the third-stage-larval (L3) exsheathment inhibition test (LEIT) and egg hatch test (EHT) on Haemonchus contortus. Extracts were tested at concentrations of 0.3, 0.6, 1.2, 2.5, 5.0, 10, 20, and 40 mg/mL. The larval exsheathment inhibition (LEI) results showed that G. sepium achieved the highest average inhibition of 91.2%, compared with 44.6% for P. dulce and 41.0% for L. leucocephala at a concentration of 40 mg/mL; the corresponding IC50 values were 22.4, 41.7, and 43.3 mg/mL, respectively. The rates of egg hatching inhibition (EHI) at a concentration of 5 mg/mL were 99.5% for G. sepium, 64.2% for P. dulce, and 54% for L. leucocephala; the corresponding IC50 values were 1.9 mg/mL for G. sepium, 3.9 mg/mL for P. dulce, and 4.3 mg/mL for L. leucocephala. The species extracts studied here were also analyzed by ultra-high performance liquid chromatography and Orbitrap high resolution mass spectrometry (UHPLC-Q/Orbitrap/MS/MS), resulting in the compounds' identification associated with AA. Glycosylated flavonoids and methoxyphenols were observed in all three species: fatty acids in G. sepium and P. dulce; phenylpropanoids, anthraquinone glycosides, amino acids and glycosylated phenolic acids in G. sepium; and flavonoids in L. leucocephala. Comparatively, G. sepium presented a greater diversity of compounds potentially active against the control of gastrointestinal nematodes, which was associated with the results obtained in the applied tests.

Reconfigurable nanophotonic silicon probes for sub-millisecond deep-brain optical stimulation.

The use of nanophotonics to rapidly and precisely reconfigure light beams for the optical stimulation of neurons in vivo has remained elusive. Here we report the design and fabrication of an implantable silicon-based probe that can switch and route multiple optical beams to stimulate identified sets of neurons across cortical layers and simultaneously record the produced spike patterns. Each switch in the device consists of a silicon nitride waveguide structure that can be rapidly (<20 µs) reconfigured by electrically tuning the phase of light. By using an eight-beam probe, we show in anaesthetized mice that small groups of single neurons can be independently stimulated to produce multineuron spike patterns at sub-millisecond precision. We also show that a probe integrating co-fabricated electrical recording sites can simultaneously optically stimulate and electrically measure deep-brain neural activity. The technology is scalable, and it allows for beam focusing and steering and for structured illumination via beam shaping. The high-bandwidth optical-stimulation capacity of the device might facilitate the probing of the spatiotemporal neural codes underlying behaviour.

Carrier envelope offset detection via simultaneous supercontinuum and second-harmonic generation in a silicon nitride waveguide.

We demonstrate a chip-scale f-2f interferometer for carrier-envelope-offset frequency (fCEO) detection. This is enabled by simultaneously producing octave-spanning coherent supercontinuum generation and second-harmonic generation in a single dispersion-engineered silicon nitride waveguide. We measure the fCEO beatnote of an 80 MHz modelocked pump source with a signal-to-noise ratio of 25 dB. Our simple approach for f-2f interferometry enables a straightforward route towards a chip-scale self-referenced frequency comb source that can operate at low pulse energies.

On-chip dual-comb source for spectroscopy.

Dual-comb spectroscopy is a powerful technique for real-time, broadband optical sampling of molecular spectra, which requires no moving components. Recent developments with microresonator-based platforms have enabled frequency combs at the chip scale. However, the need to precisely match the resonance wavelengths of distinct high quality-factor microcavities has hindered the development of on-chip dual combs. We report the simultaneous generation of two microresonator combs on the same chip from a single laser, drastically reducing experimental complexity. We demonstrate broadband optical spectra spanning 51 THz and low-noise operation of both combs by deterministically tuning into soliton mode-locked states using integrated microheaters, resulting in narrow (<10 kHz) microwave beat notes. We further use one comb as a reference to probe the formation dynamics of the other comb, thus introducing a technique to investigate comb evolution without auxiliary lasers or microwave oscillators. We demonstrate high signal-to-noise ratio absorption spectroscopy spanning 170 nm using the dual-comb source over a 20-µs acquisition time. Our device paves the way for compact and robust spectrometers at nanosecond time scales enabled by large beat-note spacings (>1 GHz).

Coherent, directional supercontinuum generation.

We demonstrate a novel approach to producing coherent, directional supercontinuum and cascaded dispersive waves using dispersion engineering in waveguides. By pumping in the normal group-velocity dispersion (GVD) regime, with two zero-GVD points to one side of the pump, pulse compression of the first dispersive wave generated in the anomalous GVD region results in the generation of a second dispersive wave beyond the second zero-GVD point in the normal GVD regime. As a result, we achieve an octave-spanning supercontinuum generated primarily to one side of the pump spectrum. We theoretically investigate the dynamics and show that the generated spectrum is highly coherent. We experimentally confirm this dynamical behavior and the coherence properties in silicon nitride waveguides by performing direct detection of the carrier-envelope-offset frequency of our femtosecond pump source using an f-2f interferometer. Our technique offers a path towards a stabilized, high-power, integrated supercontinuum source with low noise and high coherence, with applications including direct comb spectroscopy.

Photonic Needles for Light Delivery in Deep Tissue-like Media.

We demonstrate a new platform for minimally invasive, light delivery probes leveraging the maturing field of silicon photonics, enabling massively parallel fabrication of photonic structures. These Photonic Needles probes have sub-10 µm cross-sectional dimensions, lengths greater than 3 mm-surpassing 1000 to 1 aspect ratio, and are released completely into air without a substrate below. We show the Photonic Needles to be mechanically robust when inserted into 2% agarose. The propagation loss of these waveguides is low-on the order of 4 dB/cm.

Coherent mid-infrared frequency combs in silicon-microresonators in the presence of Raman effects.

We demonstrate the first low-noise mid-IR frequency comb source using a silicon microresonator. Our observation of strong Raman scattering lines in the generated comb suggests that interplay between Raman and four-wave mixing plays a role in the generated low-noise state. In addition, we characterize, the intracavity comb generation dynamics using an integrated PIN diode, which takes advantage of the inherent three-photon absorption process in silicon.

Tunable squeezing using coupled ring resonators on a silicon nitride chip.

We demonstrate continuous tuning of the squeezing-level generated in a double-ring optical parametric oscillator by externally controlling the coupling condition using electrically controlled integrated microheaters. We accomplish this by utilizing the avoided crossing exhibited by a pair of coupled silicon nitride microring resonators. We directly detect a change in the squeezing level from 0.5 dB in the undercoupled regime to 2 dB in the overcoupled regime, which corresponds to a change in the generated on-chip squeezing factor from 0.9 to 3.9 dB. Such wide tunability in the squeezing level can be harnessed for on-chip quantum-enhanced sensing protocols that require an optimal degree of squeezing.