Helge Knüttel

Flavonoid wing pigments increase attractiveness of female common blue (Polyommatus icarus) butterflies to mate-searching males

Abstract Common blue butterflies (Polyommatus icarus) sequester flavonoids from their larval host plants and allocate these UV-absorbing pigments to the wings. In field experiments using dummies constructed from female butterflies, mate-searching males inspected flavonoid-rich dummies more intensively than those with little or no flavonoids. Flavonoid content as signalled by UV-wing pattern may indicate ontogenetically determined female quality or enhance detectability to males.

The lycaenid butterfly Polyommatus icarus uses a duplicated blue opsin to see green.

SUMMARY The functional significance of gene duplication is rarely addressed at the level of animal behavior. Butterflies are excellent models in this regard because they can be trained and the use of their opsin-based visual pigments in color vision can be assessed. In the present study, we demonstrate that the lycaenid Polyommatus icarus uses its duplicate blue (B2) opsin, BRh2, in conjunction with its long-wavelength (LW) opsin, LWRh, to see color in the green part of the light spectrum extending up to 560 nm. This is in contrast to butterflies in the genus Papilio, which use duplicate LW opsins to discriminate colors in the long-wavelength range. We also found that P. icarus has a heterogeneously expressed red filtering pigment and red-reflecting ommatidia in the ventral eye region. In behavioural tests, the butterflies could not discriminate colors in the red range (570–640 nm). This finding is significant because we have previously found that the nymphalid butterfly Heliconius erato has filter-pigment mediated color vision in the long wavelength range. Our results suggest that lateral filtering pigments may not always influence color vision in insects.

VISION THROUGH COLORED EYES

The conspicuous eye-color patterns of tabanid flies have been frequently portrayed. The eye colors originate from cornea color filters, which, on.the one hand, cause colorful reflections and, on the other, alter the spectral composition of transmitted light. In this study, spectral transmission measurements of single cornea lenses were performed in order to study the visual function of cornea color filters. Spectral transmission curves allow a quantitative description of the difference between input stimulus and utilized stimulus caused by the transmission properties of this stimulus-conducting system. The external appearance of dipteran compound eyes can be explained by different reasons: 1) The eye pigments, viewed through the dioptric apparatus, result in dull colors which are usually reddish or brownish in flies Ill. 2) Layered cornea lenses cause colorful metallic reflections or interference colors [2-4, 22] so that additional reflections from eye pigments may not be recognized for the most part. 3) The cuticle of facet intersections causes reflections of pigment colors of interference colors. In most Diptera, the color of the compound eyes is rather uniform and dull. However, metallic green and even metallic multicolored compound eyes have been reported for 72 species out of 23 families of Diptera [5, 6]. Phasecontrast light microscopy and transmission electron microscopy of the metallic eyes of tabanid flies demonstrated the presence of a multiple layering of alternating layers of high and low refractive index near the front surface of the cornea lens. The variation in color and intensity of the reflections depends on the angles of viewing and illumination. The measured reflection properties of single cornea lenses of intact eyes corresponded to calculated reflection properties, which were based on the assumption that the layer systems function as interference filters composed of quarterwavelength layers [2, 3, 7]. This study examines the spatial arrangement of the various colored facets in four species with very conspicuous eye-color patterns: three tabanid flies (Chrysops relictus Meigen, Haematopota pluvialis L., Heptatoma pellucens E; Tabanidae, Diptera) and one dolichopodid fly (Hercostomus germanus Wiedemann; Dolichopodidae, Diptera), and presents spectral transmission curves of single cornea lenses. The external appearance of the colored eye patterns was described by means of observations of living specimens with a Wild M3B stereomicroscope under various illuminations. The spectral transmission of single cornea lenses was recorded with a Bentham spectrometer system (monochromator M 300 EA, photomultiplier DH 3) which was combined with a UV-transmitting objective (Zeiss Ultrafluar 32 x). The measuring aperture (q) 0.12 mm) was adjusted to the facet center. Illumination was provided by a 75-W Zeiss Xenon lamp. The light beam was adjusted at right angles to the facet surface and to the objective surface. The diameter of the measuring spot amounted to 10 gin. Raw data were taken at 5-nm increments between limits of 265 and 800 nm. For the preparation of isolated corneas, living flies were decapitated. The cornea was prepared in fly Ringer solution (150raM NaC1, 10raM KC1, 2raM CaCl 2. Fixation may strongly influence the transmission properties of cornea lenses [8, 9]. A small retouching brush was used to clean the inner cornea surface. Several cuts were made into the cornea, before it was spread in fly Ringer solution between two cover slips which were mounted on the opening of a slide. Water evaporation was prevented by sealing with Vaseline. The measuring light transmitted the top cover slip, Ringer solution, the facet center in the physiological orthodrome direction, Ringer solution, and the bottom cover slip. Reference measurements were taken from the same preparation, each in close proximity to the original measurement, but without cornea facets in the light path. The spectral transmission was calculated from original and reference measurements. In order to reduce spectral artifacts, the light path was carefully adjusted at right angles to the very center of the facets. Only minor effects were found if this method was systematically varied in order to trace spectral artifacts. The spatial arrangement of colored cornea lenses differs greatly between the tested species. The spectral transmission of cornea lenses corresponding to dark brown facets in the three tabanid species is approx. 100% throughout the range of wavelengths tested, and has no distinct minimum. The human-visible color of the metallic, colored facets corresponds to the wavelength position of the transmission minimum, as if looking at the reflection and transmission of interference filters. The spectral transmission curves of the main types of cornea lenses in the species tested are shown in Fig. 1. Measuring very fresh preparations, the calculated values of spectral transmission often surpass the 100% level which is intrinsic to the focusing effect of the lenses.

Determinants of quality of life and return to work following acute respiratory distress syndrome — a systematic review

BACKGROUND Acute respiratory distress syndrome (ARDS) in adults is a consequence of lung damage caused by either pulmonary or extrapulmonary disease. Survivors often suffer from an impaired health-related quality of life (HRQoL), mental and physical impairments, and persistent inability to work. METHODS In this systematic review of the literature, we consider the determinants of HRQoL and return to work (RtW). 24 observational studies showing a statistical association between one or more determinants and HRQoL or RtW were included. Because of the heterogeneity of these studies, no statistical aggregation of the individual effect estimates was carried out; instead, the results are summarized descriptively. RESULTS Psychopathological manifestations, in particular, are associated with impaired quality of life. In contrast, many care- and disease-related determinants had only small, non-significant effects on HRQoL and RtW. The onesecond capacity was found in all studies to be positively associated with the HRQoL. ARDS induced by sepsis seems to be a risk factor for a lower HRQoL in comparison to ARDS of other causes. A synthesis of the evidence is impeded both by the high level of heterogeneity of studies and by the high risk of selection bias in all studies. CONCLUSION The identification of determinants of impaired quality of life after ARDS is essential for the assessment of clinically relevant interventions. In multiple studies, major significant effects were only observed when determinants the content of which was closely related to the scales of the HRQoL instruments were measured at the same time as the HRQoL.

Antimicrobial efficacy of irradiation with visible light on oral bacteria in vitro: a systematic review

AIM Resistances to antibiotics employed for treatment of infectious diseases have increased to alarming numbers making it more and more difficult to treat diseases caused by microorganisms resistant to common antibiotics. Consequently, novel methods for successful inactivation of pathogens are required. In this instance, one alternative could be application of light for treatment of topical infections. Antimicrobial properties of UV light are well documented, but due to its DNA-damaging properties use for medical purposes is limited. In contrast, irradiation with visible light may be more promising. METHODS Literature was systematically screened for research concerning inactivation of main oral bacterial species by means of visible light. RESULTS Inactivation of bacterial species, especially pigmented ones, in planktonic state showed promising results. There is a lack of research examining the situation when organized as biofilms. CONCLUSION More research concerning situation in a biofilm state is required.

THE MORPHOLOGICAL VARIATIONS OF THE LATERAL PTERYGOID MUSCLE: A SYSTEMATIC REVIEW

BACKGROUND The lateral pterygoid muscle (LPM) has been described in many anatomical and functional studies. The morphology of the LPM is still under debate because of its deep location in the infratemporal fossa and the difficulties to approach this area with different anatomical methods. Although it has been generally accepted that this muscle is mainly composed of two separate parts, other forms have been described in the past. OBJECTIVES To conduct a systematic literature review regarding the anatomy and variations of the LPM. METHODS We included studies published in English, German or French employing anatomical and imaging methods or a combination of the two methods. The cadavers used in the dissections had to be human and without any pathological alterations. Studies were only included when focusing on the anatomy of the LPM or its morphological variations or when taking the frequency of variations into account. We searched 26 biomedical databases including MEDLINE, EMBASE, BIOSIS Previews and Science Citation Index Expanded (part of Web of Science) through October 2014. The review was followed by the dissection of a hemisected head in two different planes. RESULTS We identified 4279 records (2200 after deduplication) in the databases searches plus 17 articles from manual searches. 81 studies out of these articles were included in this review. 69 articles used anatomical methods, 5 imaging methods and 7 studies a combination of the two methods. 11 studies took into account that the LPM may have variations and also considered the relative frequency of each variation. The frequency of one-headed LPMs ranged between 7.7% and 26.7%, of two-headed LPMs between 61.4% and 91.1% and of three-headed LPMs between 4.0% and 35.0%. Our own dissection showed a three-headed version of the LPM. DISCUSSION In anatomical studies, different preparation techniques seem to be the main reason for diverging results.

Entwurf und prototypische Implementierung eines Metadaten-Rahmenwerks für die Digitalisierung an der Universitätsbibliothek Regensburg

An der Universitatsbibliothek Regensburg werden in mittlerem Umfang Digitalisate erstellt. Bislang fehlte fur die Digitalisate eine Erschliesung mit deskriptiven, administrativen und strukturellen Metadaten, die in geeigneter Weise die Benutzbarkeit und die Langzeitarchivierung der digitalen Dokumente unterstutzt hatte. Eine vergleichende Untersuchung bibliothekarischer Metadatenmodelle und -formate fur die Digitalisierung ergab die besondere Eignung des Metadata Encoding and Transmission Standard (METS) als Metadatenformat fur die Digitalisierung an der Universitatsbibliothek Regensburg. Der METS unterstutzt ausdrucklich die Funktionalitaten des Referenzmodells eines Open Archival Information System (OAIS) und last sich durch standardisierte Erweiterungen an zukunftige Bedurfnisse anpassen. Die neuartige Erschliesung lies sich problemlos in den Geschaftsgang integrieren. Ausgehend vom METS implementierte ich prototypisch ein Java-basiertes Erschliesungswerkzeug, das komplett modular gestaltet ist, um grostmogliche Flexibilitat fur die Verarbeitung unterschiedlicher Dokumente und Dateiformate sowie fur zukunftige Erweiterungen zu erreichen. Das Programm ist plattformunabhangig und als Client-Applikation konzipiert. Es soll die Erschliesung der Digitalisate soweit wie moglich automatisieren. Bei der Planung des Metadaten-Rahmenwerks erwies sich ein System zur Vergabe von Persistent Identifiern (PIDs) als notwendig. PIDs werden fur CD-ROMs, METS-Dokumente und Dateien benotigt. Beim Ubergang von der Speicherung der digitalen Dokumente auf CD-ROMs zu einem Online-System konnen die CD-ROM-PIDs entfallen. Das implementierte System zur Vergabe von PIDs kann jederzeit leicht zu einem URN-System mit Resolver weiterentwickelt werden. Neben der PID-Vergabe dient es auch der Authentizitatsprufung fur die digitalen Dokumente. Ich demonstrierte die mogliche Erzeugung von Prasentationsformen der digitalen Dokumente, mittels XSLT aus den in METS-Dokumenten kodierten Metadaten. Dadurch lies sich die Benutzbarkeit der Digitalisate deutlich verbessern. Diese Veroffentlichung geht zuruck auf eine Master-Arbeit im postgradualen Fernstudiengang Master of Arts (Library and Information Science) an der Humboldt-Universitat zu Berlin.