LGL Electronics (Italy)

Pollinator availability and effectiveness are important considerations in plant systems that depend on insect transfer of pollen. In mixed-flower systems (such as dioecious or gynodioecious systems), pollinators may distinguish between morphs, a behaviour which could have negative implications if it leads to reduced cross-pollination. We examined pollinator visitation, response, and effectiveness in hybrid canola seed production, a gynodioecious crop, to understand how pollinator behaviour contributes to cross-pollination between ‘male’ (hermaphroditic) and ‘female’ (male-sterile) morphs. The pollinator types found in these fields differ in visitation rate, size, and pollen load, factors that may affect pollen transfer between plants. The willingness of pollinators to move between male and female flowers can also affect pollen deposition. We used an interview bouquet to present unvisited female inflorescences to different pollinator types visiting male and female flowers to understand behavioural responses to floral morphs and the factors that contribute to better pollination effectiveness. Managed pollinators (honey and leafcutter bees) were far more abundant than wild pollinators in this system. Bees foraging on male flowers were less likely to accept a proffered female flower than those foraging on female flowers. Pollen deposition on stigmas was influenced by pollinator type (female leafcutter bees were the most effective) and increased with time spent on a flower. Pollinators transferring from a male flower to a female flower deposited more pollen than those that originated on female flowers, emphasizing the importance of transfer between male and female morphs. Surprisingly, pollinators carrying more pollen transferred less pollen to recipient stigmas.

One of the major limitations of X-ray Absorption Spectroscopy (XAS) experiment at synchrotron facilities is the performance of the detectors. In order to be able to measure more challenging samples and to cope with the very high photon flux of the current and future (diffraction limited) sources, technological developments of detectors are necessary. This article reports on the construction and characterization of a monolithic 19-channel germanium detector demonstrator fitted with CMOS preamplifiers. The detector was characterized in the laboratory with radioactive sources and with the X-ray synchrotron beam. Characteristics such as energy resolution, linearity, counting rate capabilities, and stability of the detector were thoroughly evaluated. In addition, it was proved that by using an advanced pulse processor such as Xspress4, it was possible to improve the performance of the detector system by eliminating the crosstalk among channels and by suppressing the charge-shared events. This work could pave the way to enhanced germanium fluorescence detectors for high-throughput X-ray spectroscopy.

Platypalpus pilifer Grootaert et van der Weele, sp. n. is described from the Caucasus region in Azerbaijan, Georgia and Russia. The species belongs to the Platypalpus pallidiventris-cursitans group and is characterised by very long ventral bristles on the spindle-shaped dilated fore tibia in the male. Mid femur in both male and female has a ventral black stripe over the entirely length. An extended diagnosis of the related species Platypalpus infectus It lacks long bristles on the fore tibia. The left epandrial lamella bears a lobe at the right side facing the left cercus and a long lobe at the left side. These distinct lobes are lacking in the new species. In addition numerous spinules are present on the right surstylus in P. infectus lacking in the new species.

ARDESIA, a four‐channel X‐ray spectrometer based on silicon drift detectors (SDDs), is presented. It has been developed for synchrotron applications targeting especially X‐ray fluorescence (XRF) and X‐ray absorption spectroscopy (XAS) with good energy resolution at high count rates (a few Mcps per second). The main target applications are XRF and XAFS techniques. The system features a 2 × 2 monolithic array of 5‐mm‐pitch SDDs cooled with a double Peltier scheme and coupled to a four‐channel CUBE charge preamplifier. Different digital pulse processors allowing operation in Mcps per second count rates are employed. The results of preliminary characterization measurements performed at both the LNF DAΦNE‐Light DXR1 beamline and the ESRF LISA BM‐08 are reported, in particular, XRF measurements on low atomic number elements (down to the Carbon K‐line, 270 eV) and extended X‐ray absorption fine structure of trace materials in pyrite.

Multi-element germanium detectors for X-ray fluorescence are widely used in synchrotrons. A demonstrator of highly segmented germanium detector fitted with cube preamplifier [1] for X-ray spectroscopy has been reported in this paper after a first demonstrator gave encouraging results a few years ago [2]. This demonstrator has nineteen hexagonal pixels of 2 mm pitch fitted with cube preamplifier. All the nineteen channels of this demonstrator were tested and found to be working with analogue chain electronics. Eight central channels of this demonstrator were calibrated using digital pulse processor, namely Xspress3 [3] and were exposed to beam. The beam size used was 20 µm × 20 µm so that the beam can be focused at the center of pixels and a raster scan amongst pixels can be done.

In this work we present a new version of the circuit VERDI (Versatile Readout for Detector Integration), namely VERDI-3, an integrated circuit designed for the readout of different type of radiation detectors, from nitrogen-cooled Ge and Si(Li) detectors, to silicon drift detectors (SDDs), to scintillation detectors, to photomultipliers tubes and others. VERDI-3 has been designed to achieve better noise performances in all configurations than its predecessors. The circuit is characterized by a revised programmable shaping amplifier and baseline holder, a new embedded biasing network and a revised SPI communication with added functions. The new VERDI shares the same advantages in terms of compactness for multielement detector integration and low power solution as for the rest of its family. The results of the experimental characterization of the circuit when used with different detectors are presented in this work.