65 research outputs found
Häufigkeit von Weidegängen in einem Öko-Milchviehbetrieb mit automatischem Melksystem (AMS)
Die Ergebnisse der Untersuchung zeigen, dass die Besuche am Weideselektionstor von der Tageszeit und der Laktationsnummer der Kühe abhingen. Am häufigsten wurde das Selektionstor am Abend und in der Nacht besucht. Die Zahl der Besuche reichte von null bis 3,5 pro Kuh und Tag
Past competition affects offspring foliar terpenoid concentrations, seed traits, and fitness in the invasive forb Erodium cicutarium (Geraniaceae)
Eilers E, Heger T. Past competition affects offspring foliar terpenoid concentrations, seed traits, and fitness in the invasive forb Erodium cicutarium (Geraniaceae). Frontiers in Ecology and Evolution. 2019;7: 392.(1) Environmental conditions experienced in the past may lead to intraspecific differences
in ecological and chemical traits of plants, which likely affect future responses to
altered or new environments. Whether competition by neighbors is such a trait-shaping
factor is not yet well-known. We aimed to understand how the level of ancestral plant
competition affects traits related to plant fitness and resource allocation, reproduction,
and (phyto-)toxin accumulation in offspring, and whether a potential differentiation in
these traits can be found in different geographic origins of which one belongs to the native
and one to the invaded range. (2) We compared differentiation of the following traits in
offspring plants of multiple populations in Erodium cicutarium (Geraniaceae): biomass,
seed production, seed traits related to dispersal and germination, and concentrations
of foliar mono- and sesquiterpenes. We tested the allelopatic potential of aqueous
extracts of the same E. cicutarium plants on seeds of five different plant families. (3)
In plants originating from populations that experienced high levels of competition, we
found twice as high monoterpene concentrations. These plants also produced more
biomass and a higher proportion of ripe to unripe seeds until harvesting. Seeds originating
from high competition sites were shorter. Aqueous E. cicutarium leaf extracts with
high terpenoid content reduced radicle length of Zea mays and radicle and hypocotyl
length of E. cicutarium seedlings. (4) The results of this study provide first evidence
that the surrounding vegetation may shape chemo-ecological plant traits that may be
fundamental for competitive ability. Our study calls for more research testing whether
competition experienced in the native range may lead to an enhanced capability of plants
to establish populations and spread in a new range
Sensing the underground – ultrastructure and function of sensory organs in root-feeding Melolontha melolontha (Coleoptera: Scarabaeinae) larvae
Eilers E, Talarico G, Hansson BS, Hilker M, Reinecke A. Sensing the underground – ultrastructure and function of sensory organs in root-feeding Melolontha melolontha (Coleoptera: Scarabaeinae) larvae. PLoS ONE. 2012;7(7): e41357.Introduction
Below ground orientation in insects relies mainly on olfaction and taste. The economic impact of plant root feeding scarab beetle larvae gave rise to numerous phylogenetic and ecological studies. Detailed knowledge of the sensory capacities of these larvae is nevertheless lacking. Here, we present an atlas of the sensory organs on larval head appendages of Melolontha melolontha. Our ultrastructural and electrophysiological investigations allow annotation of functions to various sensory structures.
Results
Three out of 17 ascertained sensillum types have olfactory, and 7 gustatory function. These sensillum types are unevenly distributed between antennae and palps. The most prominent chemosensory organs are antennal pore plates that in total are innervated by approximately one thousand olfactory sensory neurons grouped into functional units of three-to-four. In contrast, only two olfactory sensory neurons innervate one sensillum basiconicum on each of the palps. Gustatory sensilla chaetica dominate the apices of all head appendages, while only the palps bear thermo-/hygroreceptors. Electrophysiological responses to CO2, an attractant for many root feeders, are exclusively observed in the antennae. Out of 54 relevant volatile compounds, various alcohols, acids, amines, esters, aldehydes, ketones and monoterpenes elicit responses in antennae and palps. All head appendages are characterized by distinct olfactory response profiles that are even enantiomer specific for some compounds.
Conclusions
Chemosensory capacities in M. melolontha larvae are as highly developed as in many adult insects. We interpret the functional sensory units underneath the antennal pore plates as cryptic sensilla placodea and suggest that these perceive a broad range of secondary plant metabolites together with CO2. Responses to olfactory stimulation of the labial and maxillary palps indicate that typical contact chemo-sensilla have a dual gustatory and olfactory function
Novel set-up for low-disturbance sampling of volatile and non-volatile compounds from plant roots
Eilers E, Pauls G, Rillig MC, Hansson BS, Hilker M, Reinecke A. Novel set-up for low-disturbance sampling of volatile and non-volatile compounds from plant roots. Journal of Chemical Ecology. 2016;41(3):253-266.Most studies on rhizosphere chemicals are carried out in substrate-free set-ups or in artificial substrates using sampling methods that require an air flow and may thus cause disturbance to the rhizosphere. Our study aimed to develop a simplified and inexpensive system that allows analysis of rhizosphere chemicals at experimentally less disturbed conditions. We designed a mesocosm in which volatile rhizosphere chemicals were sampled passively (by diffusion) without air- and water flow on polydimethylsiloxane-(PDMS) tubes. Dandelion (Taraxacum sect. ruderalia) was used as model plant; roots were left undamaged. Fifteen volatiles were retrieved from the sorptive material by thermal desorption for analysis by gas chromatography/mass spectrometry (GC/MS). Furthermore, three sugars were collected from the rhizosphere substrate by aqueous extraction and derivatized prior to GC/MS analysis. In order to study how the quantity of detected rhizosphere compounds depends on the type of soil or substrate, we determined the matrix-dependent recovery of synthetic rhizosphere chemicals. Furthermore, we compared sorption of volatiles on PDMS tubes with and without direct contact to the substrate. The results show that the newly designed mesocosm is suitable for low-invasive extraction of volatile and non-volatile compounds from rhizospheres. We further highlight how strongly the type of substrate and contact of PDMS tubes to the substrate affect the detectability of compounds from rhizospheres
Application of silicone tubing for robust, simple, high - throughput , and time - resolved analysis of plant volatiles in field experiments
Kallenbach M, Veit D, Eilers E, Schuman MC. Application of silicone tubing for robust, simple, high - throughput , and time - resolved analysis of plant volatiles in field experiments. Bio-Protocol. 2015;5(3): e1391
Contribution of Pollinator-Mediated Crops to Nutrients in the Human Food Supply
The contribution of nutrients from animal pollinated world crops has not previously been evaluated as a biophysical measure for the value of pollination services. This study evaluates the nutritional composition of animal-pollinated world crops. We calculated pollinator dependent and independent proportions of different nutrients of world crops, employing FAO data for crop production, USDA data for nutritional composition, and pollinator dependency data according to Klein et al. (2007). Crop plants that depend fully or partially on animal pollinators contain more than 90% of vitamin C, the whole quantity of Lycopene and almost the full quantity of the antioxidants β-cryptoxanthin and β-tocopherol, the majority of the lipid, vitamin A and related carotenoids, calcium and fluoride, and a large portion of folic acid. Ongoing pollinator decline may thus exacerbate current difficulties of providing a nutritionally adequate diet for the global human population
An interactome-centered protein discovery approach reveals novel components involved in mitosome function and homeostasis in giardia lamblia
Protozoan parasites of the genus Giardia are highly prevalent globally, and infect a wide range of vertebrate hosts including humans, with proliferation and pathology restricted to the small intestine. This narrow ecological specialization entailed extensive structural and functional adaptations during host-parasite co-evolution. An example is the streamlined mitosomal proteome with iron-sulphur protein maturation as the only biochemical pathway clearly associated with this organelle. Here, we applied techniques in microscopy and protein biochemistry to investigate the mitosomal membrane proteome in association to mitosome homeostasis. Live cell imaging revealed a highly immobilized array of 30–40 physically distinct mitosome organelles in trophozoites. We provide direct evidence for the single giardial dynamin-related protein as a contributor to mitosomal morphogenesis and homeostasis. To overcome inherent limitations that have hitherto severely hampered the characterization of these unique organelles we applied a novel interaction-based proteome discovery strategy using forward and reverse protein co-immunoprecipitation. This allowed generation of organelle proteome data strictly in a protein-protein interaction context. We built an initial Tom40-centered outer membrane interactome by co-immunoprecipitation experiments, identifying small GTPases, factors with dual mitosome and endoplasmic reticulum (ER) distribution, as well as novel matrix proteins. Through iterative expansion of this protein-protein interaction network, we were able to i) significantly extend this interaction-based mitosomal proteome to include other membrane-associated proteins with possible roles in mitosome morphogenesis and connection to other subcellular compartments, and ii) identify novel matrix proteins which may shed light on mitosome-associated metabolic functions other than Fe-S cluster biogenesis. Functional analysis also revealed conceptual conservation of protein translocation despite the massive divergence and reduction of protein import machinery in Giardia mitosomes
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Novel Set-Up for Low-Disturbance Sampling of Volatile and Non-volatile Compounds from Plant Roots
Risk factors for necrotizing enterocolitis developed by preterm infants in dependence on their age
Die Ursachen der Nekrotisierenden Enterokolitis (NEC) sind bis heute nicht
geklärt. Wir führten eine retrospektive Krankenblattanalyse bei 101
FrĂĽhgeborenen (FG) durch, die wegen einer NEC > Stadium IIa in einem
11-Jahreszeitraum in den Kliniken fĂĽr Neonatologie Campus Benjamin Franklin
und Campus Virchow Klinikum behandelt worden waren. In dem analysierten
Zeitraum von 1993 bis 2003 sahen wir einen RĂĽckgang der Inzidenz der NEC von
7% auf 1%. Es sind zahlreiche Risikofaktoren fĂĽr die Entstehung einer NEC
bekannt. In der Literatur als signifikant wirksam diskutierte und deshalb hier
untersuchte Risikofaktoren gelten: Chorioamnionitis, arterielle Hypotonie,
Persistierender Ductus arteriosus, komplizierter enteraler Nahrungsaufbau und
nosokomiale Infektion. Unsere Hypothese war, dass diese Risikofaktoren in
verschiedenen definierten Zeiträumen mit der Entstehung einer NEC verbunden
sind. Die 101 FG wurden nach ihrem Alter bei Erkrankung an einer NEC in drei
Gruppen eingeteilt: Die FG der Gruppe 1 waren zwischen dem 1. und 14.
Lebenstag (n= 36) erkrankt, die FG der Gruppe 2 zwischen dem 15. und 28.
Lebenstag (n= 38) und die FG der Gruppe 3 nach dem 28. Lebenstag (n= 27). Die
Mortalität im Gesamtkollektiv der an einer NEC erkrankten FG betrug 19% und
entspricht damit den Angaben in der Literatur. Die FG der Gruppe 1 wiesen bei
Geburt ein höheres medianes Geburtsgewicht (1228 g) auf und zeigten ein
höheres medianes Gestationsalter (29+4 SSW), während die FG der Gruppe 3 am
unreifsten (27+0 SSW) und am leichtesten (930g) waren. Die Chorioamnionitis
und die arterielle Hypotonie gehören zu den Risikofaktoren einer frühen NEC-
Entwicklung. Wir sahen in Gruppe 1 unserer FG (Erkrankungszeitpunkt 1. -14.
LT) signifikant häufiger Chorioamnionitiden und arterielle Hypotonien am 1.
Lebenstag als in den beiden anderen Gruppen. In unserer Analyse bestätigte
sich die Hypothese, dass besonders die FG, die spät (14.-28. LT; Gruppe 2) an
einer NEC erkranken, gehäuft Probleme beim enteralen Nahrungsaufbau haben. Als
signifikante Symptome dafür haben wir eine verzögerte Mekoniumausscheidung,
vermehrt galligen Rückfluß und gehäuft stehende Darmschlingen bei den FG der
Gruppe 2 nachgewiesen- verglichen mit den Gruppen 1 und 3. Die FG der Gruppe
3, die sehr spät an einer NEC erkrankten (>28. LT), entwickelten signifikant
häufiger Zeichen einer Infektion, wie eine Erhöhung von C-reaktivem Protein
(81%), I:T-Ratio (89%) und eine verlängerte Rekapillarisierungszeit (81%).
Zusammenfassend können wir sagen, unsere retrospektive Untersuchung hat
ergeben, dass zu verschiedenen Zeitpunkten im Leben eines FrĂĽhgeborenen
unterschiedliche Risikofaktoren signifikant mit der Entstehung einer NEC
assoziiert sind. Eine frĂĽhe NEC ist mit einer Chorioamnionitis und einer
arteriellen Hypotonie verbunden, während eine späte NEC mit einem
komplizierten enteralen Nahrungsaufbau und eine sehr späte NEC mit
nosokomialen Infektionen assoziiert ist.The pathogenesis of Necrotizing Enterocolitis (NEC) has not completely been
understood until today. We analysed the clinical history of 101 preterms with
NEC (> IIa) who were treated in the clinics of neonatology Campus Benjamin
Franklin and Campus Virchow Klinikum in an eleven years` period. In the
analysed period from 1993 to 2003 we saw a decrease in the incidence of NEC
from 7% to 1%. Various risk factors are known to play a role in the
development of NEC. Those that are thought to be the most important for the
development of NEC in “Very Low Birth Weight” infants has been analysed in our
study: corioamnionitis, arterial hypotension, patent ductus arteriosus,
feeding problems and infections. We hypothized that those risk factors are
important in different defined periods in the life of a preterm infant. The
101 preterm infants were divided into 3 groups regarding the age of onset of
NEC: Group1 included all the preterm infants who presented signs of NEC in the
first two weeks of life (n=36), group 2 consisted of those pretems that
developed NEC from day 15 to day 28 ( n=38), and in group 3 were all preterms
who developed NEC after 4 weeks of life (n=27). The mortality rate in our
study collective was 19% in accordance with the death rate stated in the
specialist literature. The preterms of group 1 had the highest mean
birthweight (1228g) and the highest mean gestational age (29+4 weeks), whereas
the preterms of group 3 were the most immature preterms (27+0 weeks) with the
lowest birthweight (930g). Corioamnionitis and arterial hypotension are risk
factors for an early development of NEC. In group 1 (NEC development day 1 to
day 14) corioamnionitis and arterial hypotension on the first day of life
could be observed significantly more often than in the other groups. Our
analysis confirmed the hypothesis that preterms who develop NEC late in life
(day 14 to day 28) often show problems with feeding tolerance. Significant
risk factors for feeding intolerance as late meconium evacuation, increased
gastric residuals and abdominal distension were found more often in group 2
compared to the other groups. The preterms of group 3, who developed NEC after
28 days of life showed significantly more often signs of infections such as
elevated C-reactive protein (81%), higher I:T ratio (89%), and prolonged
capillary refilling (81%). In conclusion we can say our retrospective analysis
shows that different risk factors are associated with the onset of NEC at
different ages of preterm infants: Corioamnionitis and arterial hypotension
lead to early development of NEC, whereas late NEC is caused by feeding
problems and the very late NEC occurs in association with severe infections
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