The amount of habitat information collected with herbarium specimens traditionally depends on the commitment of individual collectors to generate free-text descriptions. The resulting incomplete and unstandardized information limits the use of specimens for many ecological and biogeographic applications and may even limit their use in taxonomy. LiDAR (light detection and ranging) is an emerging technique for generating 3D environmental laser scans and is included in the latest generation of certain commercial smartphones and tablets. Here we argue, that widespread handheld LiDAR devices have an enormous potential for herbarium specimens by facilitating the collection of detailed 3D models of specimen habitat with little additional cost in the field. Furthermore, we report our experiences with using LiDAR during herbarium specimen collection and present a perspective on how LiDAR data may technically be linked with physical herbarium specimens.

Achlorophyllous, mycoheterotrophic plants often have an elaborate mycorrhizal colonization pattern, allowing a sustained benefit from external fungal root penetrations. The present study reveals the root anatomy and mycorrhizal pattern of eight mycoheterotrophic Thismia spp. (Thismiaceae), all of which show separate tissue compartments segregating different hyphal shapes of the mycorrhizal colonization, as there are intact straight, coiled and peculiarly knotted hyphae as well as degenerated clumps of hyphal material. Those tissue compartments in Thismia roots potentially comprise exo-, meso- and endoepidermae, and exo-, meso- and endocortices, although not all species develop all these root layers. Differences in details among species according to anatomy (number of root layers, cell sizes and shapes) and colonization pattern (hyphal shapes within cells) are striking and can be discussed as an evolutionary series towards increasing mycorrhizal complexity which roughly parallels the recently established phylogeny of Thismia. We suggest functional explanations for why the distinct elements of the associations can contribute to the mycorrhizal advantage for the plants and, thus, we emphasize the relevance of structural traits for mycorrhizae.

Achlorophyllous, mycoheterotrophic plants depend on their mycorrhizal fungi for 100% of their carbon supply. Hence, there is strong evolutionary pressure towards a well-organized functioning of the association from the plant's perspective. Members of the mycoheterotrophic genus Afrothismia have evolved elaborate fungal colonization patterns allowing a sustained benefit from external fungal penetration events. On the basis of anatomical details of the root-shoot systems of A. korupensis and A. hydra, we elucidate an evolutionary progression between the comparatively simple mycorrhizal pattern in A. gesnerioides and the so far most complex mycorrhiza in A. saingei. We detected two major advancements: (1) two species, A. korupensis and A. saingei, use the fungus itself as energy storage, replacing starch depositions used by A. gesnerioides and A. hydra, and (2) the morphological complexity of hyphal forms in plant tissue compartments increases from A. gesnerioides to A. saingei. We discuss the omitting of starch metabolism as well as the morpho-anatomical differences as an evolutionary fine-tuning of the compartmented mycorrhizal organization in Afrothismia. Our results support the idea of a taxonomic distinction between Afrothismia and other Thismiaceae.

The serious problem of extended tissue thickness in the analysis of plant–fungus associations was overcome using a new method that combines physical and optical sectioning of the resin-embedded sample by microtomy and confocal microscopy. Improved tissue infiltration of the fungal-specific, high molecular weight fluorescent probe wheat germ agglutinin conjugated to Alexa Fluor® 633 resulted in high fungus-specific fluorescence even in deeper tissue sections. If autofluorescence was insufficient, additional counterstaining with Calcofluor White M2R or propidium iodide was applied in order to visualise the host plant tissues. Alternatively, the non-specific fluorochrome acid fuchsine was used for rapid staining of both, the plant and the fungal cells. The intricate spatial arrangements of the plant and fungal cells were preserved by immobilization in the hydrophilic resin Unicryl™. Microtomy was used to section the resin-embedded roots or leaves until the desired plane was reached. The data sets generated by confocal laser scanning microscopy of the remaining resin stubs allowed the precise spatial reconstruction of complex structures in the plant–fungus associations of interest. This approach was successfully tested on tissues from ectomycorrhiza (Betula pendula), arbuscular mycorrhiza (Galium aparine; Polygala paniculata, Polygala rupestris), ericoid mycorrhiza (Calluna vulgaris), orchid mycorrhiza (Limodorum abortivum, Serapias parviflora) and on one leaf–fungus association (Zymoseptoria tritici on Triticum aestivum). The method provides an efficient visualisation protocol applicable with a wide range of plant–fungus symbioses.

The mycorrhizas of 12 species of Polygala (Polygalaceae), including herbs, subshrubs and one shrub, collected from Germany, Mallorca (Spain) and Malta, were investigated by morpho-anatomical and molecular methods. Aseptate hyphae, arbuscules and vesicles indicate an arbuscular mycorrhiza in all species examined. Hyphal spread in Polygala is predominantly, but not exclusively, intracellular and comprises three characteristic stages of colonization: (i) intracellular, linear hyphal growth in a cascading manner after penetration towards the penultimate parenchyma layer (layer 2), (ii) initially linear hyphal growth in the cells of layer 2 from where hyphal branches repeatedly penetrate the anatomically distinct innermost parenchyma layer (layer 1), forming arbuscule-like structures therein which are subject to degeneration, (iii) more branches from the linear hyphae in layer 2 develop, but coil and make contact to the layer outside layer 2 (layer 3) in which arbuscule-like structures similar to those in layer 1 form and degenerate. This general colonization pattern differs in details between the species, and critical comparisons, in particular between the woody P. myrtifolia, the herbaceous Polygala spp. and the mycoheterotrophic Epirixanthes spp. (Polygalaceae) suggest an evolutionary shift of mycorrhizal features within the family towards an optimization of plant benefit through the fungus. Based on the molecular marker 18S rDNA mycorrhizal fungi detected in roots of Polygala spp. are largely restricted to five clades of Glomeraceae 1 (Glomus Group A). This result rejects the hypothesis of a strict symbiotic specificity in Polygalaceae but may stimulate a discussion on functionally compatible groups of fungi.

An efficient scattering process between the electron system in the L valley and the hole system in the Gamma valley in Ge/SiGe quantum wells is identified. Its dependencies on excitation energy and carrier density are analyzed using spectrally and time-resolved pump-probe experiments. This carrier scattering causes an ultrafast heating of the hole system leading to an additional bleaching signature appearing a few tens of picoseconds after the excitation. Our findings are supported by microscopic calculations of the absorption spectra for various carrier densities and temperatures based on the semiconductor Bloch equations. Additionally, this scattering mechanism explains the enhanced free carrier absorption observed in previously reported pump-probe experiments.

The novel semiconductor material Ga(AsBi) is investigated by the time-resolved photoluminescence as function of lattice temperature, excitation density, and excitation energy. Disorder and localization effects are found to strongly influence the spectra and the dynamics.

The classification of mycorrhizas in seven equally ranked types glosses over differences and similarities and, in particular, does not acknowledge the structural diversity of arbuscular mycorrhizas. This article emphasizes the parallel continua of ecto-related mycorrhizas and arbuscular mycorrhizas, exemplified within Ericaceae and Gentianales, respectively, as well as the proprietary development of orchid mycorrhizas, all three of which have independently developed mycoheterotrophic plants. A hierarchical classification according to structural similarities is suggested.

The complete ontogeny of the mycoheterotrophic Afrothismia hydra (Burmanniaceae) from seed to seed dispersal is presented. The oblong-ovoidal seeds are up to 0.7 mm long. They germinate with root tissue only, disrupting the seed coat and developing a primary ovoid root tubercle. At the proximal end of the tubercle, a second tubercle arises and further root initials indicate the sequential growth of more root tubercles with filiform extensions resulting in a small root aggregate. The seed coat often remains attached to this structure. When the root aggregate enlarges, a central axis to which all roots are connected becomes visible. This axis has a growth pole where new root tubercles arise. The same growth pole will later develop into a stem with scale leaves finally terminating in a flower. Flowers develop sympodially when the mature plant is only several centimetres long. After anthesis, the corolla tube disintegrates, leaving a pyxidium which opens by means of a peculiar elongating placenta, here called 'placentophore'. The placentophore elevates the placenta with attached seeds above the flowering level and is interpreted as an adaptation to ombrohydrochory. The reduction of hypocotyl, cotyledon and primary shoot is discussed with regard to the classical germination concepts of monocotyledons and with mycoheterotrophic dicotyledons. (c) 2008 The Linnean Society of London.

Optical gain and photoluminescence as well as radiative and Auger losses are calculated for Ga(AsBi)/GaAs quantum wells. The results are obtained using a consistent microscopic theory and an anticrossing model for the band structure. The influence of the band structure parameters on the optical properties is investigated.

Optical gain and photoluminescence as well as radiative and Auger losses are calculated for Ga(AsBi)/GaAs quantum wells. The results are obtained using a consistent microscopic theory and an anticrossing model for the band structure. The influence of the band structure parameters on the optical properties is investigated.

Six Rutaceae species collected from natural habitats (Malta, Mallorca (Spain), and Tenerife (Spain)) and the Botanical Garden in Marburg were examined with respect to mycorrhizal structures and fungal identity. All species have the same gross colonization pattern of arbuscular mycorrhiza (AM) with distinct intracellular and intercellular phases but show remarkable differences in details, especially in terms of the extent of the intracellular phase. The associated AM fungi, identified using molecular methods, cluster together with Glomus hoi Berch & Trappe, although the plants were collected from very distant locations.

A glacier-climate model was used to calculate climatic conditions in a test site on the east Andean slope around Cochabamba (17 degrees S, Bolivia) for the time of the maximum Late Pleistocene glaciation. Results suggest a massive temperature reduction of about -6.4 degrees C (+ 1.4/-1.3 degrees C), combined with annual precipitation rates of about 1100 mm (+570 mm/-280 mm). This implies no major change in annual precipitation compared with today. Summer precipitation was the source for the humidity in the past, as is the case today. This climate scenario argues for a maximum advance of the paleo-glaciers in the eastern cordillera during the global Last Glacial Maximum (LGM, 20 ka BP), which is confirmed by exposure age dates. In a synthesized view over the central Andes, the results point to an increased summer precipitation-driven Late Glacial (15-10 ka BP) maximum advance in the western part of the Altiplano (18 degrees S-23 degrees S), a temperature-driven maximum advance during full glacial times (LGM) in the eastern cordillera, and a pre- and post-LGM (32 ka BP/14 ka BP) maximum advance around 30 S related to increased precipitation and reduced temperature on the western slope of the Andes. The results indicate the importance of understanding the seasonality and details of the mass balance-climate interaction in order to disentangle drivers for the observed regionally asynchronous past glaciations in the central Andes. (c) 2007 Elsevier B.V. All rights reserved.

Wie die Empirie belegt, sinken mit steigender Arbeitszufriedenheit und -motivation die Fluktuations- und Absenzkosten in einem Betrieb. Den Mitarbeitenden ein motivierendes Betriebsklima zur Verfügung zu stellen, ist auch im Gesundheitswesen und damit im Fachgebiet Radiologie in zunehmendem Masse wichtig. Ziel dieser Arbeit war es deshalb, die aktuelle berufliche Zufriedenheit der Mitarbeitenden und die dafür wichtigen Einflussfaktoren zu evaluieren. Methodik: Zur Datenerhebung wurde ein standardisierter Fragebogen gewählt. Es wurden anhand von Befragungen in einer Fokusgruppe neun Indikatoren zur Charakterisierung der Arbeitszufriedenheit und -motivation festgelegt (vierstufige Ordinalskala), zusätzlich gab es die Möglichkeit von offenen Bemerkungen. Die Fragebogen wurden an alle im November 2005 anwesenden Mitarbeitenden am Institut (n = 50) für eine anonymisierte Datenerhebung verteilt. Für die statistische Auswertung wurden die Antworten codiert (Skala 1–4) und in eine Datenerfassungsmaske eingetragen. Resultate: Die Rücklaufquote betrug 92% (46 von 50). Im Allgemeinen schätzten die Befragten ihre Arbeitstätigkeit (3.37 ± 0.5), wobei kein statistisch signifikanter Unterschied zwischen Ärzten, MTRA und anderen nicht-ärztlichen Mitarbeitenden bestand. Als besonders motivierende Faktoren wurden ein gutes Betriebsklima (3.85 ± 0.4), ein guter Ruf der Abteilung (3.56 ± 0.8) und die berufliche Anerkennung genannt (3.54 ± 0.6). Gehaltserhöhungen (3.01 ± 0.9) und Zusatzleistungen wie Boni oder Prämien (3.11 ± 0.9) waren etwas weniger wichtig. Die Kommunikation zwischen den Arbeitsbereichen wurde insgesamt als relativ schlecht bewertet (2.78 ± 0.7). Bei der Frage, welche Faktoren die Arbeitsmotivation am meisten verbessern könnten, wurden insbesondere bessere Zusammenarbeit und Kommunikation (n = 9), vermehrte Einbindung in Entscheidungsprozesse (n = 8), berufliche Anerkennung (n = 7) und kontinuierliche Möglichkeit der fachlichen Weiterbildung (n = 5) genannt. Folgerung: Die genaue Kenntnis der Faktoren, die die Arbeitsmotivation und -zufriedenheit der Mitarbeitenden beeinflussen, erlaubt es gezielt entsprechende Verbesserungsmassnahmen einzuleiten.

Roots of the achlorophyllous Epirixanthes papunana and E. elongata were sectioned in complete series in order to reconstruct the three-dimensional mycorrhizal colonization pattern within their tissues. Hyphal morphology, vesicles, as well as the exclusively intracellular mode of colonization indicate a PARIS-type of arbuscular mycorrhiza showing a hitherto unknown colonization pattern: (1) the outer cortex is colonized by persistent straight-growing hyphae which branch in a cascading manner, (2) a specific layer (called layer 2) is inhabited by persistent hyphal coils, (3) in the cells of the anatomically distinct inner cortex parenchyma layer (called layer 1) the hyphae immediately degenerate, and (4) the layer outside to layer 2 (called layer 3) is either transitional layer 2 when penetrated from the outer cortex or the fungal material degenerates when colonized from the layer 2. This complex colonization pattern is a reasonable adaptation to the particular demands of Epirixanthes as a myco-heterotrophic plant. It not only allows a sustained benefit from the fungal symbiont but also provides a two-level distribution system of hyphae within the roots. The outer cortex hyphae function as a permanent intraradical resource of living fungi providing connection to the external mycelium as well as a coarse distribution of hyphae within the root. Layer 2 represents the fine scale distribution of hyphae, having access to all potentially digesting cells of the layers 1 and 3. Common structural features of mycorrhizae in myco-heterotrophic plants are pointed out in order to find putative prerequisites for their heterotrophic mode of life.

This study presents results from a glacier-climate model that reconstructed glacio-climatological conditions during the last local glaciation maximum (LLGM) in the Cordillera to the north of Cochabamba (17°15'S, 66°15'W), Bolivia. Results emphasize the temperature-sensitivity of glaciers on the eastern slope of the Cordillera Oriental. Maximum glacier advances appear to have been caused by a massive cooling of about 6.5°C while annual preeipitation was about 300 mm higher than today (850 mm/yr). Modeling results indicate maximum glacial advances during cold phases such as MIS 2 (25–18 kyr B.P.) and minor advances during late glacial cool events (12–10 kyr B.P.). This chronology is supported by exposure age dating results. Further evidence may be found in the low AAR-values (accumulation area ratio) which indicate low mass balance gradients and therefore cold climate conditions. Modeled basal shear stresses smaller than 1 bar exelude extremely «cold-dry» or «warm-wet» conditions. The spatial pattern of regional paleo-ELA's (equilibrium line altitude). with higher ELAs in the western part of the study area, reflects a strong east-west gradient in paleoprecipitation. Easterly summer preeipitation is suggested to be the reason for this phenomenon. These results are in agreement with other studies of the east-Andean slope, indicating temperature as the driving factor for maximum glacier advances in northwestern Argentina.

The subterranean organs of Afrothismia gesnerioides H. Maas consist of short rhizomes densely covered with ovoid root tubercles, each of which may extend into a short filiform root extension. Serial sections revealed the presence of two distinct fungi occupying different niches within the plant tissues. Rhizomes and roots are divided into separate compartments hosting different morphotypes of the aseptate, exclusively intracellular hyphae of fungus A: (i) straight and persistent hyphae in the root epidermis, root extension, and outer rhizome cortex, (ii) coiled but still persistent hyphae in the third root layer, (iii) coiled hyphae undergoing degeneration in the root cortical parenchyma, (iv) starch depositions in the inner rhizome cortex and no colonization by fungus A, and (v) a partly collapsed root hypodermis serving as compartment barrier. The colonization by fungus A is interpreted as an aberrant arbuscular mycorrhiza of the Paris type. The compartmentation allows the separation of tissues where the hyphae stay functional from those in which the fungal material is digested. This pattern may represent a complex but efficient strategy for a sustained benefit from the few fungal penetrations that occur. Comparison with earlier work on Afrothismia winkleri (Engl.) Schltr. revealed considerable differences between the mycorrhizae that are interpreted as evolutionary steps. There are signs that these changes even may have improved the mycorrhizal benefit for the plant. The monomorphic hyphae of fungus B are smaller in diameter, septate, grow inter- as well as intra-cellularly, but are always characteristically appressed to the inner cell walls. It does not change its appearance within the root/rhizome compartments as does fungus A. Neither hyphal degeneration nor interferences with fungus A, starch depositions, or alterations in the development of A. gesnerioides could be noticed. Fungus B possibly is a commensal, but relevance to the symbiosis cannot be ruled out.