Expanding crop diversity is essential to address the imminent challenges of agriculture. This is especially true for organic farming, which relies on locally adapted species and varieties. Recently, participatory research approaches have emerged as effective means to support this endeavour. In this study, we collaborated with several stakeholders in the Lyon region, France, to evaluate three minor species related to common wheat (Triticum aestivum subsp. aestivum): einkorn (Triticum monococcum subsp. monococcum), emmer (Triticum turgidum subsp. dicoccum) and spelt (Triticum aestivum subsp. spelta (L.) Thell). First, we assessed the agronomic characteristics of each species, highlighting a distinction of einkorn that was associated with high tillering, high protein content, a long phenological cycle, small kernels and low relative yields. Second, we compared intra-species variabilities, revealing greater variation in emmer and spelt. Lastly, outcomes of the participatory approach, including testing adaptive methods and fostering collective learning, may interest other participatory research groups.

We present herein a joint physical/physico-chemical study and, more specifically, the first application of Matrix Assisted Laser Desorption Ionization coupled with Time of Flight Mass Spectrometry (MALDI-TOF-MS) to analyze small-sized ZnO quantum dots (QDs) (2.8-3.1 nm diameter range) synthesized by sol-gel chemistry and stabilized through an aminosilane coating. A careful investigation of the stability of ZnO QDs was initiated once these dots were dispersed in different media (water, biological buffer) for a period up to 3 weeks. Positive ion mode mass spectra MALDI-TOF-MS combined with optical spectrometry was used to monitor the stability of ZnO QDs when aging. Such a unique combination of MALDI-TOF-MS and physico-chemical techniques is likely to bring new insights into the structure analysis, the stability and consequently the potential toxicity of QDs.

Soft ionization mass spectrometry (MS) methods [Electro-Spray Ionisation - Fourier Transform Ion Cyclotronic Resonance MS (ESI-FTICRMS) and Matrix Assisted Laser Desorption Ionization coupled with Time of Flight MS (MALDI-TOFMS)] and associated fragmentation techniques appear to be an alternative way providing data on the size, stability and exact chemical composition of nanoparticles and their precursors, and potentially on interactions between particles. We report the application of both mass spectrometry techniques to analyze II-VI semiconductor nanomaterials (CdX with X = S or Se) and their organometallic precursors.

The growth of InGaN layers was carried out by molecular beam epitaxy (MBE). The nitrogen precursor was ammonia. The optical and structural properties of the InGaN layers have been investigated by transmission electron microscopy (TEM), x-ray diffraction (XRD) and photoluminescence (PL). For optimized growth conditions, the PL spectrum of InGaN (x=0.1) alloy is narrow (FWHM ≤ 50 meV) and the Stokes shift measured by PL excitation is weak (<50 meV), i.e. near band edge transitions are observed. Under these conditions, flat surfaces can be obtained, and InGaN/GaN quantum wells (QWs) with sharp interfaces can be grown. On the other hand, when growth conditions depart from a narrow optimum window, the structural quality of the samples strongly degrade, whereas the luminescence spectra are dominated by deep levels, exhibiting a strong Stokes shift. MBE grown light emitting diodes (LEDs) using InGaN/GaN QWs have been fabricated. Their electroluminescence (EL) peaks at 440 nm at 300K.

The growth of InGaN layers was carried out by molecular beam epitaxy (MBE). The nitrogen precursor was ammonia. The optical and structural properties of the InGaN layers have been investigated by transmission electron microscopy (TEM), x-ray diffraction (XRD) and photoluminescence (PL). For optimized growth conditions, the PL spectrum of InGaN (x=0.1) alloy is narrow (FWHM ≤ 50 meV) and the Stokes shift measured by PL excitation is weak (<50 meV), i.e. near band edge transitions are observed. Under these conditions, flat surfaces can be obtained, and InGaN/GaN quantum wells (QWs) with sharp interfaces can be grown. On the other hand, when growth conditions depart from a narrow optimum window, the structural quality of the samples strongly degrade, whereas the luminescence spectra are dominated by deep levels, exhibiting a strong Stokes shift. MBE grown light emitting diodes (LEDs) using InGaN/GaN QWs have been fabricated. Their electroluminescence (EL) peaks at 440 nm at 300K.