Legume Fingerprinting through Lipid Composition: Utilizing GC/MS with Multivariate Statistics.

This study presents a tentative analysis of the lipid composition of 47 legume samples, encompassing species such as Phaseolus spp., Vicia spp., Pisum spp., and Lathyrus spp. Lipid extraction and GC/MS (gas chromatography with mass spectrometric detection) analysis were conducted, followed by multivariate statistical methods for data interpretation. Hierarchical Cluster Analysis (HCA) revealed two major clusters, distinguishing beans and snap beans (Phaseolus spp.) from faba beans (Vicia faba), peas (Pisum sativum), and grass peas (Lathyrus sativus). Principal Component Analysis (PCA) yielded 2D and 3D score plots, effectively discriminating legume species. Linear Discriminant Analysis (LDA) achieved a 100% accurate classification of the training set and a 90% accuracy of the test set. The lipid-based fingerprinting elucidated compounds crucial for discrimination. Both PCA and LDA biplots highlighted squalene and fatty acid methyl esters (FAMEs) of 9,12,15-octadecatrienoic acid (C18:3) and 5,11,14,17-eicosatetraenoic acid (C20:4) as influential in the clustering of beans and snap beans. Unique compounds, including 13-docosenoic acid (C22:1) and γ-tocopherol, O-methyl-, characterized grass pea samples. Faba bean samples were discriminated by FAMEs of heneicosanoic acid (C21:0) and oxiraneoctanoic acid, 3-octyl- (C18-ox). However, C18-ox was also found in pea samples, but in significantly lower amounts. This research demonstrates the efficacy of lipid analysis coupled with multivariate statistics for accurate differentiation and classification of legumes, according to their botanical origins.

Simple and complex, sexually dimorphic retinal mosaic of fritillary butterflies.

Butterflies have variable sets of spectral photoreceptors that underlie colour vision. The photoreceptor organization may be optimized for the detection of body coloration. Fritillaries (Argynnini) are nymphalid butterflies exhibiting varying degrees of sexual dimorphism in wing coloration. In two sister species, the females have orange (Argynnis paphia) and dark wings (Argynnis sagana), respectively, while the males of both species have orange wings with large patches of pheromone-producing androconia. In spite of the differences in female coloration, the eyes of both species exhibit an identical sexual dimorphism. The female eyeshine is uniform yellow, while the males have a complex retinal mosaic with yellow and red-reflecting ommatidia. We found the basic set of ultraviolet-, blue- and green-peaking photoreceptors in both sexes. Males additionally have three more photoreceptor classes, peaking in green, yellow and red, respectively. The latter is the basal R9, indirectly measured through hyperpolarizations in the green-peaking R1-2. In many nymphalid tribes, including the closely related Heliconiini, the retinal mosaic is complex in both sexes. We hypothesize that the simple mosaic of female Argynnini is a secondary reduction, possibly driven by the use of olfaction for intraspecific recognition, whereas vision remains the primary sense for the task in the males. This article is part of the theme issue 'Understanding colour vision: molecular, physiological, neuronal and behavioural studies in arthropods'.

Opponent processing in the retinal mosaic of nymphalid butterflies.

The eyes of nymphalid butterflies, investigated with incident illumination, show colourful facet reflection patterns-the eye shine-which is uniform or heterogeneous, dependent on the species. Facet colours suggest that the ommatidia contain different sets of photoreceptors and screening pigments, but how the colours and the cell characteristics are associated has not been clearly established. Here, we analyse the retinae of two nymphalids, Apatura ilia, which has a uniform eyeshine, and Charaxes jasius, a species with a heterogeneous eye shine, using single-cell recordings, spectroscopy and optical pupillometry. Apatura has UV-, blue- and green-sensitive photoreceptors, allocated into three ommatidial types. The UV- and blue-sensitive cells are long visual fibres (LVFs), receiving opponent input from the green-sensitive short visual fibres (SVFs). Charaxes has an expanded set of photoreceptors, allocated into three additional, red-reflecting ommatidial types. All red ommatidia contain green-sensitive LVFs, receiving opponent input from red receptors. In both species, the SVFs do not receive any opponent input. The simple retina of Apatura with three ommatidial types and two colour-opponent channels can support trichromatic vision. Charaxes has six ommatidial types and three colour-opponent channels. Its expanded receptor set can support tetrachromatic vision. This article is part of the theme issue 'Understanding colour vision: molecular, physiological, neuronal and behavioural studies in arthropods'.

Feasibility study of separation and purification of bile acid derivatives by HPLC on C18 and F5 columns.

Organic synthesis could be very demanding, usually due to difficulties related to the separation of main reaction products from by-products. Steroidal compounds could have similar lipophilicity, which is mostly based on the lipophilicity of the steroidal core. This causes many problems during purification, i.e. in obtaining a pure single steroidal compound. In this research, a group of bile acid derivatives were subjected to HPLC analysis using four experimental systems, which presented combinations of C18 and F5 columns with methanol-water and acetonitrile-water as mobile phases. Retention parameters and retention order of the compounds were established and indicated that all experimental systems could be applicable in order to separate and/or purify some individual compounds or a mixture of a few compounds. However, the only experimental system that could separate a mixture of all investigated derivatives proved to be a C18 column with acetonitrile-water as a mobile phase. Since complex interactions between F5 column and the analytes exist, molecular surface polarity (MSP) was tested as a lipophilicity parameter, and also compared with logP using multivariate statistics. Retention parameters obtained on F5 column were used as descriptors, both with MSP and with logP, concluding that logP has shown to be a better lipophilicity descriptor.

Connectome of the lamina reveals the circuit for early color processing in the visual pathway of a butterfly.

Connectomics has become a standard neuroscience methodology in a few model animals,1 with the visual system being a popular target of study.2-5 Combining connectomics with circuit and behavioral physiology, recent studies on the color vision of the fruit fly Drosophila melanogaster have focused on the mechanisms underlying early wavelength processing in the optic ganglia.6-8 However, the color vision capabilities of D. melanogaster are limited,9 compared with many flower-visiting insects.10,11 For example, a butterfly Papilio xuthus has six spectral classes of photoreceptors. Each ommatidium contains nine photoreceptors in one of three fixed combinations, making the eye an array of three spectrally distinct ommatidia types.12 Behaviorally, P. xuthus can detect 1 nm differences in light wavelength across the spectrum from ultraviolet to red, outperforming humans.13 What is the neuronal basis of such precise color vision? How does such a system evolve? Addressing these questions requires comparative studies at the circuit level. Here, we performed a connectome analysis in the first optic ganglion, the lamina, of P. xuthus. The lamina comprises cartridges, each typically containing nine photoreceptor axons from a single ommatidium and four second-order neurons. We found abundant inter-photoreceptor connections, which are absent in the lamina of D. melanogaster. We also identified connections between neighboring cartridges, particularly those receiving inputs from spectrally distinct ommatidia. The linear summation of synaptic connections well explains the spectral sensitivity of photoreceptors and second-order neurons in the lamina.

Red-green opponency in the long visual fibre photoreceptors of brushfoot butterflies (Nymphalidae).

In many butterflies, the ancestral trichromatic insect colour vision, based on UV-, blue- and green-sensitive photoreceptors, is extended with red-sensitive cells. Physiological evidence for red receptors has been missing in nymphalid butterflies, although some species can discriminate red hues well. In eight species from genera Archaeoprepona, Argynnis, Charaxes, Danaus, Melitaea, Morpho, Heliconius and Speyeria, we found a novel class of green-sensitive photoreceptors that have hyperpolarizing responses to stimulation with red light. These green-positive, red-negative (G+R-) cells are allocated to positions R1/2, normally occupied by UV and blue-sensitive cells. Spectral sensitivity, polarization sensitivity and temporal dynamics suggest that the red opponent units (R-) are the basal photoreceptors R9, interacting with R1/2 in the same ommatidia via direct inhibitory synapses. We found the G+R- cells exclusively in butterflies with red-shining ommatidia, which contain longitudinal screening pigments. The implementation of the red colour channel with R9 is different from pierid and papilionid butterflies, where cells R5-8 are the red receptors. The nymphalid red-green opponent channel and the potential for tetrachromacy seem to have been switched on several times during evolution, balancing between the cost of neural processing and the value of extended colour information.

Neural mechanism of spatio-chromatic opponency in the Drosophila amacrine neurons.

Visual animals detect spatial variations of light intensity and wavelength composition. Opponent coding is a common strategy for reducing information redundancy. Neurons equipped with both spatial and spectral opponency have been identified in vertebrates but not yet in insects. The Drosophila amacrine neuron Dm8 was recently reported to show color opponency. Here, we demonstrate Dm8 exhibits spatio-chromatic opponency. Antagonistic convergence of the direct input from the UV-sensing R7s and indirect input from the broadband receptors R1-R6 through Tm3 and Mi1 is sufficient to confer Dm8's UV/Vis (ultraviolet/visible light) opponency. Using high resolution monochromatic stimuli, we show the pale and yellow subtypes of Dm8s, inheriting retinal mosaic characteristics, have distinct spectral tuning properties. Using 2D white-noise stimulus and reverse correlation analysis, we found that the UV receptive field (RF) of Dm8 has a center-inhibition/surround-excitation structure. In the absence of UV-sensing R7 inputs, the polarity of the RF is inverted owing to the excitatory input from the broadband photoreceptors R1-R6. Using a new synGRASP method based on endogenous neurotransmitter receptors, we show that neighboring Dm8s form mutual inhibitory connections mediated by the glutamate-gated chloride channel GluClα, which is essential for both Dm8's spatial opponency and animals' phototactic behavior. Our study shows spatio-chromatic opponency could arise in the early visual stage, suggesting a common information processing strategy in both invertebrates and vertebrates.

Two chiral types of randomly rotated ommatidia are distributed across the retina of the flathead oak borer Coraebus undatus (Coleoptera: Buprestidae).

Jewel beetles are colorful insects, which use vision to recognize their conspecifics and can be lured with colored traps. We investigated the retina and coloration of one member of this family, the flathead oak borer Coraebus undatus using microscopy, spectrometry, polarimetry, electroretinography and intracellular recordings of photoreceptor cell responses. The compound eyes are built of a highly unusual mosaic of mirror-symmetric or chiral ommatidia that are randomly rotated along the body axes. Each ommatidium has eight photoreceptors, two of them having rhabdomeres in tiers. The eyes contain six spectral classes of photoreceptors, peaking in the UV, blue, green and red. Most photoreceptors have moderate polarization sensitivity with randomly distributed angular maxima. The beetles have the necessary retinal substrate for complex color vision, required to recognize conspecifics and suitable for a targeted design of color traps. However, the jewel beetle array of freely rotated ommatidia is very different from the ordered mosaic in insects that have object-directed polarization vision. We propose that ommatidial rotation enables the cancelling out of polarization signals, thus allowing stable color vision, similar to the rhabdomeric twist in the eyes of flies and honeybees.

Horsefly object-directed polarotaxis is mediated by a stochastically distributed ommatidial subtype in the ventral retina.

The ventral compound eye of many insects contains polarization-sensitive photoreceptors, but little is known about how they are integrated into visual functions. In female horseflies, polarized reflections from animal fur are a key stimulus for host detection. To understand how polarization vision is mediated by the ventral compound eye, we investigated the band-eyed brown horsefly Tabanus bromius using anatomical, physiological, and behavioral approaches. Serial electron microscopic sectioning of the retina and single-cell recordings were used to determine the spectral and polarization sensitivity (PS) of photoreceptors. We found 2 stochastically distributed subtypes of ommatidia, analogous to pale and yellow of other flies. Importantly, the pale analog contains an orthogonal analyzer receptor pair with high PS, formed by an ultraviolet (UV)-sensitive R7 and a UV- and blue-sensitive R8, while the UV-sensitive R7 and green-sensitive R8 in the yellow analog always have low PS. We tested horsefly polarotaxis in the field, using lures with controlled spectral and polarization composition. Polarized reflections without UV and blue components rendered the lures unattractive, while reflections without the green component increased their attractiveness. This is consistent with polarotaxis being guided by a differential signal from polarization analyzers in the pale analogs, and with an inhibitory role of the yellow analogs. Our results reveal how stochastically distributed sensory units with modality-specific division of labor serve as separate and opposing input channels for visual guidance.

The giant butterfly-moth Paysandisia archon has spectrally rich apposition eyes with unique light-dependent photoreceptor dynamics.

The palm borer moth Paysandisia archon (Burmeister, 1880) (fam. Castniidae) is a large, diurnally active palm pest. Its compound eyes consist of ~ 20,000 ommatidia and have apposition optics with interommatidial angles below 1°. The ommatidia contain nine photoreceptor cells and appear structurally similar to those in nymphalid butterflies. Two morphological ommatidial types were identified. Using the butterfly numbering scheme, in type I ommatidia, the distal rhabdom consists exclusively of the rhabdomeres of photoreceptors R1-2; the medial rhabdom has contributions from R1-8. The rhabdom in type II ommatidia is distally split into two sub-rhabdoms, with contributions from photoreceptors R2, R3, R5, R6 and R1, R4, R7, R8, respectively; medially, only R3-8 and not R1-2 contribute to the fused rhabdom. In both types, the pigmented bilobed photoreceptors R9 contribute to the rhabdom basally. Their nuclei reside in one of the lobes. Upon light adaptation, in both ommatidial types, the rhabdoms secede from the crystalline cones and pigment granules invade the gap. Intracellular recordings identified four photoreceptor classes with peak sensitivities in the ultraviolet, blue, green and orange wavelength regions (at 360, 465, 550, 580 nm, respectively). We discuss the eye morphology and optics, the photoreceptor spectral sensitivities, and the adaptation to daytime activity from a phylogenetic perspective.

The Fly Sensitizing Pigment Enhances UV Spectral Sensitivity While Preventing Polarization-Induced Artifacts.

Microvillar photoreceptors are intrinsically capable of detecting the orientation of e-vector of linearly polarized light. They provide most invertebrates with an additional sensory channel to detect important features of their visual environment. However, polarization sensitivity (PS) of photoreceptors may lead to the detection of polarization-induced false colors and intensity contrasts. Most insect photoreceptors are thus adapted to have minimal PS. Flies have twisted rhabdomeres with microvilli rotated along the length of the ommatidia to reduce PS. The additional UV-absorbing sensitizing pigment on their opsin minimizes PS in the ultraviolet. We recorded voltage from Drosophila photoreceptors R1-6 to measure the spectral dependence of PS and found that PS in the UV is invariably negligible but can be substantial above 400 nm. Using modeling, we demonstrate that in R1-6 without the sensitizing pigment, PS in the UV (PS UV ) would exceed PS in the visible part of the spectrum (PS VIS ) by a factor PS UV /PS VIS = 1.2-1.8, as lower absorption of Rh1 rhodopsin reduces self-screening. We use polarimetric imaging of objects relevant to fly polarization vision to show that their degree of polarization outdoors is highest in the short-wavelength part of the spectrum. Thus, under natural illumination, the sensitizing pigment in R1-6 renders even those cells with high PS in the visible part unsuitable for proper polarization vision. We assume that fly ventral polarization vision can be mediated by R7 alone, with R1-6 serving as an unpolarized reference channel.

A fast multispectral light synthesiser based on LEDs and a diffraction grating.

Optical experiments often require fast-switching light sources with adjustable bandwidths and intensities. We constructed a wavelength combiner based on a reflective planar diffraction grating and light emitting diodes with emission peaks from 350 to 630 nm that were positioned at the angles corresponding to the first diffraction order of the reversed beam. The combined output beam was launched into a fibre. The spacing between 22 equally wide spectral bands was about 15 nm. The time resolution of the pulse-width modulation drivers was 1 ms. The source was validated with a fast intracellular measurement of the spectral sensitivity of blowfly photoreceptors. In hyperspectral imaging of Xenopus skin circulation, the wavelength resolution was adequate to resolve haemoglobin absorption spectra. The device contains no moving parts, has low stray light and is intrinsically capable of multi-band output. Possible applications include visual physiology, biomedical optics, microscopy and spectroscopy.

Four photoreceptor classes in the open rhabdom eye of the red palm weevil, Rynchophorus ferrugineus Olivier.

The red palm weevil (RPW) is a severe palm pest with high dispersal capability. Its visual sense allows it to navigate long distances and to discriminate among differently colored traps. We investigated the RPW compound eyes with anatomical and electrophysiological methods. The ommatidia are composed of eight photoreceptor cells in an open rhabdom arrangement with six peripheral and two central photoreceptors. The photoreceptor signals are relatively slow and noisy. The majority of recorded photoreceptors have broad spectral sensitivity with a peak in the green, at 536 nm. Three minor classes of photoreceptors have narrower spectral sensitivities with maxima in the UV (366 nm), green (520 nm) and yellow (564 nm). Sensitivity below 350 nm is very low due to filtering by the UV-absorbing cornea. The set of photoreceptors represents the retinal substrate for putative trichromatic color vision.

[Surgical anatomy of the initial segment of the lateral circumflex femoral artery].

INTRODUCTION: The lateral circumflex femoral artery usually originates from the lateral side of the initial part of the deep femoral artery, or less frequently from the femoral artery. If it is a branch of the femoral artery, it arises directly above the point of origin of the deep femoral artery. The aim of this study was to determine the origin of the lateral circumflex femoral artery, its origin distance from the midpoint of the inguinal ligament and the topographical relations of the origin, which have a great significance in clinical work. MATERIAL AND METHODS: A dissection was performed on the autopsy group of 42 thighs, followed by the analysis of anatomical relationships of the lateral circumflex femoral artery. All data were entered into the custom-made protocol, which contained the case number, age and sex, side, topographical-anatomical relations of the lateral circumflex femoral artery, artery dimensions and variations, and the distance between the place of origin of the lateral circumflex femoral artery and the midpoint of the inguinal ligament. RESULTS: In our study, the lateral circumflex femoral artery most frequently originated from the deep femoral artery, i.e. in 78.6% of cases. In 19.0% of limbs, it originated from the femoral artery, and in one case (2.4%) from a common stem of the deep femoral artery and the lateral circumflex femoral artery, coming from the femoral artery. CONCLUSION: In clinical practice, it is of great importance to know the origin variations of the lateral circumflex femoral artery while planning and performing various surgical and invasive diagnostic procedures in the inguino-femoral region.

Origin of the medial circumflex femoral artery--a cadaver study.

AIM: To determine the pattern of origin of medial circumflex femoral artery (MCFA), its origin distance from the midpoint of the inguinal ligament and the topographical relations of the origin, which have great significance in clinical work. METHODS: Dissections on the autopsy group of 42 thighs were performed, and anatomical relationships of MCFA was analyzed. All data were entered into a scheme of the protocol which was designed for this research containing the case number, age and sex, side, topographical-anatomical relations of MCFA, artery dimensions and variations, and the distance between the place of origin of MCFA and the midpoint of the inguinal ligament. RESULTS: Commonly, in 25 (59.5%) limbs MCFA originated from the deep femoral artery. In 14 (33.3%) limbs MCFA arose from the femoral artery (FA), in one case (2.4%) a common source of deep femoral artery (DFA) and MCFA was identified, and in two limbs MCFA was not noticed. The distance between the level of origin of MCFA and the central point of the inguinal ligament was 44.2 mm, in average, when it was emerging from FA, and 57.9 mm, in average, in cases where MCFA originated from DFA. CONCLUSION: Surgeons and radiologists should be familiar with the variations of clinically important MCFA, which is commonly involved in peripheral occlusive arterial diseases, to improve effectiveness of diagnosis and treatment of various pathological conditions in the femoral region.

[Main morphological characteristics of the vascular pedicle of Latissimus dorsi muscle and their relevance in operative treatment].

INTRODUCTION: Considering operative treatment of various pathological conditions and traumatic injuries of extremities latissimus dorsi flap presents the most frequently used flap in reconstructive surgery. OBJECTIVE: The aim of this paper was to analyze anatomical characteristics of the vascular pedicle of the latissimus dorsi muscle followed by morphometric analyzes of vascular elements. METHODS: This paper was carried out in cooperation with the Institute of Anatomy of the School of Medicine, University of Belgrade. The study was based on 40 cadaver dissections followed by anatomical and morphometric analyzes. The first analysis included the determination of thoracodorsal artery (TDA) origin and its lateral and terminal branches, and the second one the observation of artery path. Furthermore the same features were analyzed on the thoracodorsal vein. During morphometric analyzes artery and vein length and diameter were recorded. RESULTS: Our results showed that TDA always contains one lateral branch, while three other lateral branches were inconstant. In most cases TDA terminated in two branches, upper and lower, with average distance of 3.4 cm from the muscle. The mean recorded pedicle length was 9.9 cm. The average inner diameter of TDA was 1.85 mm. In further analyses the average observed thoracodorsal vein length was 10.5 cm with mean diameter of 2.93 mm. The result showed that vein origin was usually represented with two branches. CONCLUSION: The thoracodorsal artery is a blood vessel of considerable length and diameter which represents a great advantage in reconstructive flap surgery.