Dimethyl cis-4-hydroxy­methyl­piperidine-2,6-dicarboxyl­ate

The heterocyclic core of the title compound, C10H17NO5, adopts a chair conformation with its three C substituents positioned equatorially. In the crystal, inter­molecular O—H⋯N hydrogen bonds between neighbouring mol­ecules lead to chains along b. These chains are connected by hydro­phobic inter­actions, forming infinite layers and N—H⋯O=C contacts between mol­ecules of adjacent layers give rise to a three-dimensional structure

tert-Butyl 1-hy­droxy­piperidine-2-carboxyl­ate

The title compound, C10H19NO3, is a disubstituted piperidine bearing substituents in two equatorial positions. One of the substituents is a hy­droxy group bound to nitro­gen and the second a tert-butyl ester group bound to the carbon next to the endocyclic nitro­gen. Enanti­omers of the title compound form hydrogen-bridged dimers across a center of inversion

In the translator's workshop

Hunayn ibn Ishaq's Arabic translation of Galen's commentary on the Hippocratic Epidemics is an invaluable source for our knowledge of Galenic medicine and its transmission history, not least because much of it is extant only in Arabic. Its importance for the Arabic medical tradition is amply attested in the later medical literature. It also tells us much about the methods and self-image of contemporary translators. Throughout the translation, we find remarks by Hunayn discussing the quality of his source text, his own interpretation and also his attempts to reconstruct problematic or damaged passages. Based on an edition of these notes, their analysis and comparison to similar texts and Galen's own thought on editing and interpreting difficult medical texts, this article aims to situate Hunayn's methods in the context of the Greek-Arabic translation movement. It argues that his approach differs in important respects from that of preceding Greek-Arabic and Greek-Syriac translators and that he was indebted to Galen not just as a physician, but also as a translator and exegete

HyperART: non-invasive quantification of leaf traits using hyperspectral absorption-reflectance-transmittance imaging

BackgroundCombined assessment of leaf reflectance and transmittance is currently limited to spot (point) measurements. This study introduces a tailor-made hyperspectral absorption-reflectance-transmittance imaging (HyperART) system, yielding a non-invasive determination of both reflectance and transmittance of the whole leaf. We addressed its applicability for analysing plant traits, i.e. assessing Cercospora beticola disease severity or leaf chlorophyll content. To test the accuracy of the obtained data, these were compared with reflectance and transmittance measurements of selected leaves acquired by the point spectroradiometer ASD FieldSpec, equipped with the FluoWat device.ResultsThe working principle of the HyperART system relies on the upward redirection of transmitted and reflected light (range of 400 to 2500 nm) of a plant sample towards two line scanners. By using both the reflectance and transmittance image, an image of leaf absorption can be calculated. The comparison with the dynamically high-resolution ASD FieldSpec data showed good correlation, underlying the accuracy of the HyperART system. Our experiments showed that variation in both leaf chlorophyll content of four different crop species, due to different fertilization regimes during growth, and fungal symptoms on sugar beet leaves could be accurately estimated and monitored. The use of leaf reflectance and transmittance, as well as their sum (by which the non-absorbed radiation is calculated) obtained by the HyperART system gave considerably improved results in classification of Cercospora leaf spot disease and determination of chlorophyll content.ConclusionsThe HyperART system offers the possibility for non-invasive and accurate mapping of leaf transmittance and absorption, significantly expanding the applicability of reflectance, based on mapping spectroscopy, in plant sciences. Therefore, the HyperART system may be readily employed for non-invasive determination of the spatio-temporal dynamics of various plant properties

Non-Invasive Spectral Phenotyping Methods can Improve and Accelerate Cercospora Disease Scoring in Sugar Beet Breeding

Breeding for Cercospora resistant sugar beet cultivars requires field experiments for testing resistance levels of candidate genotypes in conditions that are close to agricultural cultivation. Non-invasive spectral phenotyping methods can support and accelerate resistance rating and thereby speed up breeding process. In a case study, experimental field plots with strongly infected beet genotypes of different resistance levels were measured with two different spectrometers. Vegetation indices were calculated from measured wavelength signature to determine leaf physiological status, e.g., greenness with the Normalized Differenced Vegetation Index (NDVI), leaf water content with the Leaf Water Index (LWI) and Cercospora disease severity with the Cercospora Leaf Spot Index (CLSI). Indices values correlated significantly with visually scored disease severity, thus connecting the classical breeders’ scoring approach with advanced non-invasive technology