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Temporal variability in native plant composition clouds impact of increasing non-native richness along elevational gradients in Tenerife
Get PDFIntroductions of non-native plant species and their rates of expansion into novel environments are rapidly climbing, and their impact on recipient community composition is currently not well documented. Under the influence of rapidly intensifying human activity, pathways such as roads support such range expansions, especially in vulnerable mountain regions. Using species composition and abundance data collected in disturbed and natural habitats along three mountain roads covering almost 2500 m in elevation, we investigate how non-native plant species impact temporal change in community composition and spatial community dissimilarity on the island of Tenerife over 14 years. We found that, within communities, the number of both native and non-native species increased over time in disturbed habitats, while non-native species richness decreased in natural habitats. While species composition of communities changed over time, this change was not greater with or without non-native species, though any signal of non-native species’ influence was likely lost due to the surprisingly high variability in the native community. In disturbed roadside habitats, turnover of species over time played a larger role in temporal change in community composition than changes in species’ abundances. Despite increases in richness and occurrences along the elevation gradient, non-native species did not spatially homogenize communities. Although impacts of non-native species on temporal changes in community dissimilarity were presently not found, increases in the number of non-native species and their occurrences illustrate the need for long-term monitoring of altitudinal spread in mountain plant communities, especially in anthropogenically disturbed habitats
Proximity effects and aggregation of Hamilton-receptor barbiturate host–guest complexes probed by cross-metathesis and ESI MS analysis
Get PDFThe molecular environment around supramolecular bonding systems significantly affects their stability and the assembly of host–guest complexes, most prominent for hydrogen bonds (H-bonds). Hamilton receptor-barbiturate host–guest complexes are well-known in solution, typically forming a 1 : 1 molar ratio complex. However, within a polymer matrix, these complexes can form higher-order assemblies, deviating from the standard 1 : 1 complex, which are challenging to characterize and often require lab-intensive methods. In this study, a novel Hamilton receptor (H) was equipped with cyclopentene moieties and used as a host to form host-guest complexes (H-B) with allobarbital (B), followed by covalent crosslinking. UV-Vis spectroscopy titration experiments in different solvents and at various temperatures revealed that polar solvents containing additional H-bonding sites significantly reduce the formation of the 1 : 1 H-B complex, as indicated by a reduced association constant. Higher-order aggregates (HH-dimer, HHH-trimer) were subsequently detected via an alkene cross-metathesis (CM) reaction to fix the assemblies covalently, followed by analysis via electrospray ionization mass spectrometry (ESI MS). This two-step method, firstly via CM fixation followed by ESI MS, was extended to study the H-B model complex within a polyisobutylene (PIB) matrix, presenting a direct method to analyze the complex host-guest assembly in solvent-free (polymer) environments
Sensomotorische Adaptation einer Zielbewegung unter vorheriger Bewegung der kontralateralen Extremität
Get PDFWir untersuchten die sensomotorische Adaptation einer bimanuellen sequenziellen Bewegung in verschieden ausgerichteten Kraftfeldern. Wir konnten zeigen, dass eine Adaptation der rechten oberen Extremität möglich ist, wenn eine Vorbewegung mit der linken oberen Extremität durchgeführt wird, die mit der Richtung des Kraftfeldes assoziiert ist. Die Adaptation erfolgt hierbei langsamer, als wenn die Vorbewegung ebenfalls mit der rechten oberen Extremität durchgeführt wird. Unsere Studie liefert neue Erkenntnisse über den Zusammenhang zwischen sensomotorischer Adaptation und bimanuellen Bewegungen. Weitere Studien sind nötig, um die neuronalen Korrelate und Anwendungen im klinischen Kontext näher zu untersuchen
Magnetoelectric properties of bulk 0-3 Fe/BaTiO3-composites
No full textMagnetoelectric 0-3 Fex/(BaTiO3)1−x composites (x = 0.1–0.8) were synthesized by reduction of Fe2O3/BaTiO3 pellets in forming gas. In a subsequent sintering step, dense composite ceramics were formed. Depending on the oxygen getter used in the sintering step (carbon or zirconium carbide) a partly iron-doped or undoped ferroelectric barium titanate matrix is obtained, which encloses micrometer-sized ferromagnetic Fe particles. The experimentally determined iron contents derived from Rietveld refinements and magnetic measurements are in good agreement with the nominal ones in the undoped composites. Field dependent magnetoelectric measurements revealed only small differences between the composites with doped and undoped BaTiO3 component when the magnetic field and the polarization are oriented parallel to each other. For samples with iron-doped BaTiO3, additional third extrema at low fields were found when the field was oriented perpendicular to the electric polarization whereas undoped samples exhibited only two extrema. The largest αME values were measured for the Fex/(BaTiO3)1−x composites with x = 0.4 (parallel) and x = 0.3 (perpendicular). Based on the integral of αME, the magnetostriction of iron and a phenomenological model describing the connection between magnetostriction and the magnetoelectric effect was derived. In temperature-dependent magnetoelectric investigations the low-temperature phase transitions of BaTiO3 (tetragonal → orthorhombic → rhombohedral) were detected.3 in Fe/BaTiO3-composites im Titel tiefgestell
MLUH-E-417_2, Pernis apivorus (Linnaeus, 1758), eggshell
No full textInventory No.: MLUH-E-417_2, Object: eggshell, Species: Pernis apivorus (Linnaeus, 1758), Preservation: slight damage, Locality_loc.: Braunschweig, Locality today: Brunswick, Country: GermanyCollector_leg.: Prof. Dr. R. Blasius, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 155, Identification by: M. Schönwetter, Aquisition: 1941, Aquired from: Naturkundemuseum Braunschweig, ex Collection: ex. Coll. Prof. Dr. R. Blasius ; ex. Coll. Naturkundemuseum Braunschweig, Additional Information: The catalogue says comes from W. Behrends no mention of Blasius or the museu
MLUH-E-235_2, Buteo buteo (Linnaeus, 1758), eggshell
No full textInventory No.: MLUH-E-235_2, Object: eggshell, Species: Buteo buteo (Linnaeus, 1758), Preservation: severe damage, Locality_loc.: Harburg, Locality today: Harburg, Country: GermanyCollector_leg.: F. Woinke, Date: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 166, Identification by: M. Schönwetter, Aquisition: 1939, Aquired from: J. F. G. Umlauff, ex Collection: ex. Coll. F. Woinke; ex. Coll: J. F. G. Umlauf
MLUH-E-44_1, Falco eleonorae Géné, 1839, eggshell
No full textInventory No.: MLUH-E-44_1, Object: eggshell, Species: Falco eleonorae Géné, 1839, Preservation: good preservation, Locality_loc.: Cykladen, Locality today: Cyclades, Country: GreeceCollector_leg.: Dr. T. J. Krüper, Date: 15/08/1864, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 191, Identification by: M. Schönwetter, Aquisition: 1927, Aquired from: Dr. Henrici, ex Collection: ex. Coll. Dr. T. J. Krüpe
A comprehensive database of expert-curated occurrences for the Genus Carex L. (Cyperaceae)
No full textMotivation
Geographic occurrences are essential for biodiversity studies, but publicly available repositories like GBIF often contain errors and biases, especially for taxonomically complex groups like Carex L. (Cyperaceae). This work provides an expert-curated global dataset of occurrences compiled from different sources to enhance data accuracy and usability. The final dataset includes 384,067 occurrences of 1790 Carex species.
Main Types of Variables Contained
The dataset includes species occurrence records with geographic coordinates, taxonomic identifications, and curation flags (e.g., introduced, erroneous records).
Spatial Location and Grain
The dataset covers a global scale, using the WGS84 projection. Spatial resolution is standardised to a minimum of three decimal degrees (~1 km, if possible).
Time Period and Grain
Online records span from 1950 to 2020, but some manually georeferenced records are earlier (1850). There is also fieldwork data after 2020, specifically up to 2023.
Major Taxa and Level of Measurement
Cyperaceae: Carex. Most records have species-level identification, and some of them are identified at subspecies or variety levels.
Software Format
Data are supplied as comma-separated values files with UTF-8 encoding
Prognostic impact of the choice of chemotherapy after first-line CDK4/6 inhibitor therapy in patients with metastatic hormone receptor-positive, HER2-negative breast cancer
No full textIntroduction:
Whereas CDK4/6 inhibitors (CDK4/6i) are the standard first-line therapy for patients with hormone receptor-positive (HRpos), HER2-negative (HER2neg) metastatic breast cancer, guidelines on treatment options after progression on CDK4/6i are more diverse. Chemotherapy is recommended if a patient develops endocrine resistance or experiences a visceral crisis. However, the impact of the choice of chemotherapy remains unknown.
Methods:
HRpos/HER2neg patients who received first-line CDK4/6i, followed by second-line chemotherapy (N =215) were selected from the prospective PRAEGNANT registry (NCT02338167). Cox regression analyses were used to evaluate the correlation between the choice of chemotherapy (capecitabine monotherapy, cape
citabine +bevacizumab, taxane monotherapy, taxane +bevacizumab, anthracycline, other chemotherapeutics) and progression-free survival (PFS) and overall survival (OS).
Results:
Patients who received second-line chemotherapy mostly had high-grade tumors (G2: 62.3 %, G3: 33.3 %), visceral metastases (62.3 %) and developed metastatic disease following a primary breast cancer diagnosis (73.8 %). Capecitabine was the most common regimen (25.1 %), followed by taxane +bevacizumab (17.2 %). When adjusting for other prognostic factors (age, BMI, grading, ECOG, metastasis group and time to metastases), the choice of chemotherapy did not influence PFS (p =0.16) nor OS (p =0.47). Adjusted hazard ratios for PFS were lowest in regimens with bevacizumab (capecitabine as reference; capecitabine +bev
acizumab: 0.53 (95 %CI: 0.29, 0.97); taxane +bevacizumab: 0.64 (95 %CI 0.35, 1.15)).
Conclusion:
Although the choice of chemotherapy post-CDK4/6i did not significantly affect PFS or OS, combi
nations with bevacizumab may have some benefit. Nevertheless, considering side effects may be most important when choosing the type of second-line chemotherapy
MLUH-E-63_1, Falco columbarius aesalon Tunstall 1771, eggshell
No full textInventory No.: MLUH-E-63_1, Object: eggshell, Species: Falco columbarius aesalon Tunstall 1771, Preservation: complete preservation, Locality_loc.: Lappland, Locality today: Russia/Finland/Sweden/Norway, Country: Russia/Finland/Sweden/NorwayDate: 12/06/1902, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 191, Identification by: M. Schönwetter, Aquisition: 1904, Aquired from: O. Bamberg, ex Collection: ex. Coll. O. Bamberg, Additional Information: Hair fissure; signed with a V