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Hilfe für Erez Israel
(2020)
This review analyzes the potential role and long-term effects of field perennial polycultures (mixtures) in agricultural systems, with the aim of reducing the trade-offs between provisioning and regulating ecosystem services. First, crop rotations are identified as a suitable tool for the assessment of the long-term effects of perennial polycultures on ecosystem services, which are not visible at the single-crop level. Second, the ability of perennial polycultures to support ecosystem services when used in crop rotations is quantified through eight agricultural ecosystem services. Legume-grass mixtures and wildflower mixtures are used as examples of perennial polycultures, and compared with silage maize as a typical crop for biomass production. Perennial polycultures enhance soil fertility, soil protection, climate regulation, pollination, pest and weed control, and landscape aesthetics compared with maize. They also score lower for biomass production compared with maize, which confirms the trade-off between provisioning and regulating ecosystem services. However, the additional positive factors provided by perennial polycultures, such as reduced costs for mineral fertilizer, pesticides, and soil tillage, and a significant preceding crop effect that increases the yields of subsequent crops, should be taken into account. However, a full assessment of agricultural ecosystem services requires a more holistic analysis that is beyond the capabilities of current frameworks.
Reaching the Sustainable Development Goals requires a fundamental socio-economic transformation accompanied by substantial investment in low-carbon infrastructure. Such a sustainability transition represents a non-marginal change, driven by behavioral factors and systemic interactions. However, typical economic models used to assess a sustainability transition focus on marginal changes around a local optimum, whichby constructionlead to negative effects. Thus, these models do not allow evaluating a sustainability transition that might have substantial positive effects. This paper examines which mechanisms need to be included in a standard computable general equilibrium model to overcome these limitations and to give a more comprehensive view of the effects of climate change mitigation. Simulation results show that, given an ambitious greenhouse gas emission constraint and a price of carbon, positive economic effects are possible if (1) technical progress results (partly) endogenously from the model and (2) a policy intervention triggering an increase of investment is introduced. Additionally, if (3) the investment behavior of firms is influenced by their sales expectations, the effects are amplified. The results provide suggestions for policy-makers, because the outcome indicates that investment-oriented climate policies can lead to more desirable outcomes in economic, social and environmental terms.
Preface
(2020)
Since 2004 a giant portrait of the ancient Dacian king Decebalus can be seen by people visiting the Đerdap national park in Serbia or sailing along the Danube. The location is carefully chosen: the ancient king is located on the other side of the river, within the Romanian Parcul Natural Porțile de Fier, but is carved in the rock so to look in the direction from where, at the beginning of the 2nd century CE, the Romans came to move war to him and his people. Not by chance, on the Serbian side of the river and not far away from the sculpture is the Tabula Traiana, a Roman inscription celebrating the opening of the Roman road leading here in 100 CE. This article moves from the role of ancient Rome in the historical cultures and national identities of the two countries facing each other here, Serbia and Romania, in order to explain how the Romans represented a ‘contested identity’ and therefore why, at the end of the 20th century, the Romanian nationalistic millionaire G. C. Drăgan decided to invest a humongous quantity of money in the realization of the sculpture of Decebalus.
EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution
(2017)
This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.
Background: In health research, indicators of socioeconomic status (SES) are often used interchangeably and often lack theoretical foundation. This makes it difficult to compare results from different studies and to explore the relationship between SES and health outcomes. To aid researchers in choosing appropriate indicators of SES, this article proposes and tests a theory-based selection of SES indicators using chronic back pain as a health outcome. Results: Chronic back pain intensity was best predicted by the multidimensional index (beta = 0.31, p < 0.05), followed by job position (beta = 0.29, p < 0.05) and education (beta = -0.29, p < 0.05); whereas, income exerted no significant influence. Back pain disability was predicted strongest by education (beta = -0.30, p < 0.05) and job position (beta = 0. 29, p < 0.05). Here, multidimensional index and income had no significant influence. Conclusions: The choice of SES indicators influences predictive power on both back pain dimensions, suggesting SES predictors cannot be used interchangeably. Therefore, researchers should carefully consider prior to each study which SES indicator to use. The introduced framework can be valuable in supporting this decision because it allows for a stable prediction of SES indicator influence and their hierarchy on a specific health outcomes.
Meteorological conditions during the ACLOUD/PASCAL field campaign near Svalbard in early summer 2017
(2018)
The two concerted field campaigns, Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) and the Physical feedbacks of Arctic planetary boundary level Sea ice, Cloud and AerosoL (PASCAL), took place near Svalbard from 23 May to 26 June 2017. They were focused on studying Arctic mixed-phase clouds and involved observations from two airplanes (ACLOUD), an icebreaker (PASCAL) and a tethered balloon, as well as ground-based stations. Here, we present the synoptic development during the 35-day period of the campaigns, using near-surface and upper-air meteorological observations, as well as operational satellite, analysis, and reanalysis data. Over the campaign period, short-term synoptic variability was substantial, dominating over the seasonal cycle. During the first campaign week, cold and dry Arctic air from the north persisted, with a distinct but seasonally unusual cold air outbreak. Cloudy conditions with mostly low-level clouds prevailed. The subsequent 2 weeks were characterized by warm and moist maritime air from the south and east, which included two events of warm air advection. These synoptical disturbances caused lower cloud cover fractions and higher-reaching cloud systems. In the final 2 weeks, adiabatically warmed air from the west dominated, with cloud properties strongly varying within the range of the two other periods. Results presented here provide synoptic information needed to analyze and interpret data of upcoming studies from ACLOUD/PASCAL, while also offering unprecedented measurements in a sparsely observed region.
In an overt visual priming experiment, we investigate the role of orthography in native (L1) and non-native (L2) processing of German morphologically complex words. We compare priming effects for inflected and derived morphologically related prime-target pairs versus otherwise matched, purely orthographically related pairs. The results show morphological priming effects in both the L1 and L2 group, with no significant difference between inflection and derivation. However, L2 speakers, but not L1 speakers, also showed significant priming for orthographically related pairs. Our results support the claim that L2 speakers focus more on surface-level information such as orthography during visual word recognition. This can cause orthographic priming effects in morphologically related prime-target pairs, which may conceal L1-L2 differences in morphological processing.
Plants frequently have to weather both biotic and abiotic stressors, and have evolved sophisticated adaptation and defense mechanisms. In recent years, chromatin modifications, nucleosome positioning, and DNA methylation have been recognized as important components in these adaptations. Given their potential epigenetic nature, such modifications may provide a mechanistic basis for a stress memory, enabling plants to respond more efficiently to recurring stress or even to prepare their offspring for potential future assaults. In this review, we discuss both the involvement of chromatin in stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory.
This paper challenges the solely rational view of the scenario technique as a strategy and foresight tool designed to cope with uncertainty by considering multiple possible future states. The paper employs an affordance-based view that allows for the identification and structuring of hidden, emergent attributes of the scenario technique beyond the intended ones. The suggested framework distinguishes between affordances (1) that are intended by the organization and relate to its goals, (2) that emergently generate organizational benefits, and (3) that do not relate to organizational but individual interests. Also, constraints in the use of scenarios are discussed. Affordance theory’s specific lens shows that the emergence of such attributes depends on the users’ specific intentions.
The possibility to manufacture perovskite solar cells (PSCs) at low temperatures paves the way to flexible and lightweight photovoltaic (PV) devices manufactured via high-throughput roll-to-roll processes. In order to achieve higher power conversion efficiencies, it is necessary to approach the radiative limit via suppression of non-radiative recombination losses. Herein, we performed a systematic voltage loss analysis for a typical low-temperature processed, flexible PSC in n-i-p configuration using vacuum deposited C-60 as electron transport layer (ETL) and two-step hybrid vacuum-solution deposition for CH3NH3PbI3 perovskite absorber. We identified the ETL/absorber interface as a bottleneck in relation to non-radiative recombination losses, the quasi-Fermi level splitting (QFLS) decreases from similar to 1.23 eV for the bare absorber, just similar to 90 meV below the radiative limit, to similar to 1.10 eV when C-60 is used as ETL. To effectively mitigate these voltage losses, we investigated different interfacial modifications via vacuum deposited interlayers (BCP, B4PyMPM, 3TPYMB, and LiF). An improvement in QFLS of similar to 30-40 meV is observed after interlayer deposition and confirmed by comparable improvements in the open-circuit voltage after implementation of these interfacial modifications in flexible PSCs. Further investigations on absorber/hole transport layer (HTL) interface point out the detrimental role of dopants in Spiro-OMeTAD film (widely employed HTL in the community) as recombination centers upon oxidation and light exposure. [GRAPHICS] .
We present an X-ray-optical cross-correlator for the soft (> 150 eV) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%. (C) 2016 Author(s).
Online hate is a topic that has received considerable interest lately, as online hate represents a risk to self-determination and peaceful coexistence in societies around the globe. However, not much is known about the explanations for adolescents posting or forwarding hateful online material or how adolescents cope with this newly emerging online risk. Thus, we sought to better understand the relationship between a bystander to and perpetrator of online hate, and the moderating effects of problem-focused coping strategies (e.g., assertive, technical coping) within this relationship. Self-report questionnaires on witnessing and committing online hate and assertive and technical coping were completed by 6829 adolescents between 12 and 18 years of age from eight countries. The results showed that increases in witnessing online hate were positively related to being a perpetrator of online hate. Assertive and technical coping strategies were negatively related with perpetrating online hate. Bystanders of online hate reported fewer instances of perpetrating online hate when they reported higher levels of assertive and technical coping strategies, and more frequent instances of perpetrating online hate when they reported lower levels of assertive and technical coping strategies. In conclusion, our findings suggest that, if effective, prevention and intervention programs that target online hate should consider educating young people about problem-focused coping strategies, self-assertiveness, and media skills. Implications for future research are discussed.
Humans generate internal models of their environment to predict events in the world. As the environments change, our brains adjust to these changes by updating their internal models. Here, we investigated whether and how 9-month-old infants differentially update their models to represent a dynamic environment. Infants observed a predictable sequence of stimuli, which were interrupted by two types of cues. Following the update cue, the pattern was altered, thus, infants were expected to update their predictions for the upcoming stimuli. Because the pattern remained the same after the no-update cue, no subsequent updating was required. Infants showed an amplified negative central (Nc) response when the predictable sequence was interrupted. Late components such as the PSW were also evoked in response to unexpected stimuli; however, we found no evidence for a differential response to the informational value of surprising cues at later stages of processing. Infants rather learned that surprising cues always signal a change in the environment that requires updating. Interestingly, infants responded with an amplified neural response to the absence of an expected change, suggesting a top-down modulation of early sensory processing in infants. Our findings corroborate emerging evidence showing that infants build predictive models early in life.
Franz Ferdinand Julius Meyen (1804–1840) veröffentlichte auf sehr vielen Gebieten der Biologie wichtige Arbeiten, vor allem in Botanik und Zoologie. Mit Unterstützung Alexander von Humboldts gelang es ihm, auf dem Forschungsschiff „Prinzess Louise“ anzuheuern und als Schiffsarzt an einer mehrjährigen Weltreise teilzunehmen. Humboldt, der einige Regionen ebenfalls besucht und erforscht hatte, unterstützte seinen jungen Kollegen bei der Vorbereitung seiner Reise. Meyen veröffentlichte seine Reiseergebnisse bereits kurz nach seiner Rückkehr, gefördert von Christian Gottfried Nees von Esenbeck (1776–1858), sowohl als zweiteiligen historischen Reisebericht als auch in sieben Einzelabhandlungen. Einige Ergebnisse, die er, schwerkrank, nicht selbst verwerten konnte, übergab er noch bei Lebzeiten zur Bearbeitung an Spezialisten, andere wurden posthum von Mitgliedern der Leopoldina publiziert. Meyen brachte u. a. eine umfangreiche Sammlung an Vogelpräparaten mit, zu denen auch das Erstbeschreibungsexemplar des von ihm so genannten Spheniscus humboldti (Trivialname: Humboldt-Pinguin) gehört.
Humboldt hat auf seiner Russlandreise 1829 eine Anzahl von Büchern und Schriften in mongolischer, kalmükischer, armenischer, chinesischer, tibetischer und mandschurischer Sprache als Geschenk erhalten. Darüber hinaus hat er drei persische Handschriften käuflich erworben. Das umfangreichste Stück ist der chinesische Roman Geschichte der Drei Reiche. Humboldt hatte den Altphilologen und Kenner des Armenischen und Chinesischen, Carl Friedrich Neumann, gebeten, diese Titel zu katalogisieren. Als die Liste im Druck erschien (während Neumann sich auf einer Chinareise befand), führten die Monita zu einer Gelehrtenfehde. Danach gerieten die Bücher, eine bunte Mischung, bald in Vergessenheit. Vorliegender Artikel gibt eine Liste auf Grund des heutigen Befundes in der Staatsbibliothek zu Berlin, für die der Sammler die Bücher von Anfang an bestimmt hatte, wie mehrere Beischriften belegen.
Im Jahr 1836 traf der US-amerikanische Geistliche und Sammler historischer Dokumente William B. Sprague (1795–1876) während seines zweiten Europabesuches auch mit Alexander von Humboldt in Berlin zusammen. Im Verlaufe des Gespräches zeigte sich Humboldt mit den politischen Entwicklungen in den Vereinigten Staaten bestens vertraut. Er kritisierte das Sklavensystem, räumte aber auch ein, dass er viele Aspekte der amerikanischen Demokratie bewunderte.
In his “Essay on the Fluctuations in the Supplies of Gold” (1838) Humboldt presents a global history of the flow of precious metals from antiquity to the 19th century. This paper traces Humboldt’s economic thinking within his natural and historical research, starting with an outline of his educational background which incorporated late mercantilist and early liberal influences. It then discusses a world map and four charts drawn by Humboldt, which combine historical and contemporary statistical data into a cartographical vision of a global economic circuit. In a next step, the article explores Humboldt’s application of natural and historical research methods in the field of political economy, using the example of his 1838 essay. Finally, the article addresses Humboldt’s discussion of platinum, a precious metal whose limited natural distribution contradicted the idea of free global exchange.
Das von Alexander von Humboldt ab 1804 oder später verfasste Manuskript „Isle de Cube. Antilles en général“ wurde erst kürzlich zum ersten Mal veröffentlicht. Es stellt die Grundlage für den Essai politique sur l‘île de Cuba (1826) dar, der als das „wichtigste liberale Manifest des 19. Jahrhunderts gegen die Sklaverei“ gilt. Ziel der Untersuchung ist, die textgenetische inhaltliche und stilistische Entwicklung vom Manuskript zur Publikation ansatzweise nachverfolgen zu können, um Rückschlüsse auf Humboldts Arbeitsweise und Strategien als Autor mit einem politischen Anliegen zu ziehen.
Sobre ríos y canales
(2017)
Con ejemplos inéditos del legado de Humboldt, este artículo presenta un importante aspecto de su viaje: Humboldt realizó mediciones, calculó sus resultados con métodos matemáticos, dibujó mapas y contrastó sus datos con los de sus antecesores. Luego, publicó mapas de alta calidad, y dio consejos a otros viajeros para que al recorrer regiones que él no pudo visitar, pudieran completarse sus propios mapas. En el legado de Humboldt se refleja el provecho que el viajero tomó de mapas y datos de otros viajeros, comerciantes y científicos. Los países latinoamericanos recién independizados mostraron un creciente interés en realizar un intercambio con Europa. Con el colombiano Joaquín Acosta, Humboldt inició una relación de ayuda mutua, esp. sobre la región de Chocó, que era de gran interés por la minería del platino y oro y por la comunicación interoceánica.
Alexander von Humboldt war in Polen bereits im ausgehenden 18. Jahrhundert berühmt geworden. Er reiste mehrmals nach Polen und unterhielt Kontakte zu polnischen oder polnischstämmigen Wissenschaftlern. Aus den 30er und 40er Jahren stammen die meisten schriftlichen Belege, die von Beziehungen Humboldts zu solchen Persönlichkeiten wie Ludwik Zejszner, Józef Waraszkiewicz oder Filip Neryusz Walter zeugen. Nicht nachweisbar ist heute dafür Humboldts Kontakt zu Wincenty Pol sowie zu Ignacy Domeyko. Humboldt inspiriert nicht nur polnische Wissenschaftler, sondern auch führende polnische Dichter der Romantik. Viele polnische Exilanten verdanken dem deutschen Gelehrten wertvolle Kontakte, Empfehlungsschreiben und Gesuche bei damaligen Machthabern.
Das Akademienvorhaben „Alexander von Humboldt auf Reisen – Wissenschaft aus der Bewegung“ (AvH-R) hat Anfang 2015 mit einer projektierten Laufzeit von 18 Jahren seine Arbeit an der Berlin-Brandenburgischen Akademie der Wissenschaften aufgenommen. Die Hauptaufgabe von AvH-R besteht in der vollständigen Herausgabe der Humboldt‘schen Manuskripte zum Themenkomplex Reisen an der Schnittstelle von Kultur- und Naturwissenschaften. Die Schriftenreihe des Akademienvorhabens AvH-R läuft unter dem Titel Edition Humboldt und ist hybrid angelegt. Die Printedition der Tagebücher – Edition Humboldt – ist als Lesefassung konzipiert. Die Edition Humboldt digital zielt auf eine möglichst umfassende textorientierte Transkription und Kommentierung der Handschriften sowie auf eine intelligente Nutzung normdateibasierter Webdienste und Informationsangebote. Die ersten Ergebnisse wurden im Herbst 2016 der Öffentlichkeit unter avhr.bbaw.de präsentiert und werden hier zusammengefasst vorgestellt.
Alexander von Humboldt hat sich in jungen Jahren mit galvanischen Experimenten beschäftigt und die Resultate in einem umfassenden, zweibändigen Werk publiziert. Dabei zeigte er nicht nur, dass er als Experimentator und Teil der wissenschaftlichen Gemeinschaft fähig war, sich mit einem so neuen und komplexen Phänomen zu beschäftigen. Es lässt sich auch erkennen, dass er bereits in dieser frühen Schrift versuchte, das umfangreiche Wissen dem Leser zugänglich zu machen.
Der Artikel betrachtet Humboldts Galvanismusschrift Versuche über die gereizte Muskel- und Nervenfaser (1797–1798) und untersucht einige Elemente wie Anhänge und Schreibstil, die Humboldt nutzte, um die umfangreichen Informationen zu ordnen und dem Leser so neben den Big Data seiner Erkenntnisse auch passende Suchfunktionen zur Verfügung zu stellen, die eine gezielte Nutzung überhaupt ermöglichen.
Die Korrespondenz zwischen Alexander von Humboldt und Karl Kreil war umfangreich und betraf den Erdmagnetismus. Aber heute ist nur noch ein einziger Brief im Original bekannt. Dieser Brief, den Kreil am 3. September 1836 Alexander von Humboldt zukommen ließ, stimmt inhaltlich und teilweise wortwörtlich mit dem Brief überein, den Kreil nur einen Tag später, am 4. September 1836, an Carl Friedrich Gauß schickte. Vier Briefe von Kreil an Humboldt wurden in den „Annalen der Physik und Chemie“ publiziert, eine nicht allzu große Anzahl weiterer Briefe an Humboldt wurde in der biographischen Literatur über Kreil und in Briefen Kreils an Koller und Gauß erwähnt. Aber nicht nur die lückenhafte und bruchstückhaft bekannte Korrespondenz zwischen Humboldt und Kreil, die bis 1851 reicht, gibt Aufschluss über die Beziehungen, sondern von besonderer Bedeutung ist des Weiteren der Bestand an Kreiliana in der Bibliothek Humboldts. Es handelt sich um neun Werke Kreils, das letzte aus dem Jahr 1856. Nachweisbare Kontakte zwischen Kreil und Humboldt fanden also mit Sicherheit mindestens bis zu diesem Jahr statt!
El Ensayo sobre la geografía de las plantas de Alexander von Humboldt ha trascendido como una de sus principales propuestas científicas, fundamento de lo que se conoce hoy como “biogeografía”. El origen de este concepto es difuso hasta el momento de la publicación simultánea de su obra en París y en Tübingen, en 1807. El presente artículo propone contrastar la primera versión manuscrita de este ensayo, elaborada en 1803 en Guayaquil y luego leída en 1805 en el Institut National de Paris, con la obra contemporánea del neogranadino Francisco José de Caldas, con quien convivió en Quito en el primer semestre de 1802.
La référence à Colomb est un lieu commun de la biographie humboldtienne. Humboldt lui-même le souligne particulièrement dans son Examen critique, en y ajoutant une dimension autobiographique. La contribution analyse, dans une perspective philologique, le matériel et les formes de mise en scène avec lesquelles une vie est représentée au travers d'une autre.
Ein unveröffentlichter Brief Alexander von Humboldts an den Buchhändler Jean-Georges Treuttel
(2016)
In der Lilly Library der Indiana University befindet sich ein kurzer unveröffentlichter Brief Alexander von Humboldts an den Buchhändler und Autor Jean-Georges Treuttel. Dieser Artikel unternimmt den Versuch, den historisch-bibliographischen Kontext des Briefes herzustellen und ihn in Humboldts wissenschaftliches Schaffen einzuordnen.
Background: Endogenous murine leukemia retroviruses (MLVs) are high copy number proviral elements difficult to comprehensively characterize using standard low throughput sequencing approaches. However, high throughput approaches generate data that is challenging to process, interpret and present.
Results: Next generation sequencing (NGS) data was generated for MLVs from two wild caught Mus musculus domesticus (from mainland France and Corsica) and for inbred laboratory mouse strains C3H, LP/J and SJL. Sequence reads were grouped using a novel sequence clustering approach as applied to retroviral sequences. A Markov cluster algorithm was employed, and the sequence reads were queried for matches to specific xenotropic (Xmv), polytropic (Pmv) and modified polytropic (Mpmv) viral reference sequences.
Conclusions: Various MLV subtypes were more widespread than expected among the mice, which may be due to the higher coverage of NGS, or to the presence of similar sequence across many different proviral loci. The results did not correlate with variation in the major MLV receptor Xpr1, which can restrict exogenous MLVs, suggesting that endogenous MLV distribution may reflect gene flow more than past resistance to infection.
We extend the scope of European palaeogenomics by sequencing the genomes of Late Upper Palaeolithic (13,300 years old, 1.4-fold coverage) and Mesolithic (9,700 years old, 15.4-fold) males from western Georgia in the Caucasus and a Late Upper Palaeolithic (13,700 years old, 9.5-fold) male from Switzerland. While we detect Late Palaeolithic-Mesolithic genomic continuity in both regions, we find that Caucasus hunter-gatherers (CHG) belong to a distinct ancient clade that split from western hunter-gatherers similar to 45 kya, shortly after the expansion of anatomically modern humans into Europe and from the ancestors of Neolithic farmers similar to 25 kya, around the Last Glacial Maximum. CHG genomes significantly contributed to the Yamnaya steppe herders who migrated into Europe similar to 3,000 BC, supporting a formative Caucasus influence on this important Early Bronze age culture. CHG left their imprint on modern populations from the Caucasus and also central and south Asia possibly marking the arrival of Indo-Aryan languages.
Background: Development of eukaryotic organisms is controlled by transcription factors that trigger specific and global changes in gene expression programs. In plants, MADS-domain transcription factors act as master regulators of developmental switches and organ specification. However, the mechanisms by which these factors dynamically regulate the expression of their target genes at different developmental stages are still poorly understood.
Results: We characterized the relationship of chromatin accessibility, gene expression, and DNA binding of two MADS-domain proteins at different stages of Arabidopsis flower development. Dynamic changes in APETALA1 and SEPALLATA3 DNA binding correlated with changes in gene expression, and many of the target genes could be associated with the developmental stage in which they are transcriptionally controlled. We also observe dynamic changes in chromatin accessibility during flower development. Remarkably, DNA binding of APETALA1 and SEPALLATA3 is largely independent of the accessibility status of their binding regions and it can precede increases in DNA accessibility. These results suggest that APETALA1 and SEPALLATA3 may modulate chromatin accessibility, thereby facilitating access of other transcriptional regulators to their target genes.
Conclusions: Our findings indicate that different homeotic factors regulate partly overlapping, yet also distinctive sets of target genes in a partly stage-specific fashion. By combining the information from DNA-binding and gene expression data, we are able to propose models of stage-specific regulatory interactions, thereby addressing dynamics of regulatory networks throughout flower development. Furthermore, MADS-domain TFs may regulate gene expression by alternative strategies, one of which is modulation of chromatin accessibility.
The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (similar to 22x) and seven to similar to 1x coverage, to investigate the impact of these on Europe's genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence.
Die vorliegende Abhandlung beschäftigt sich mit einem bisher wenig beachteten Aspekt von Humboldts Amerikanischer Reise (1799─1804). Während seine Studien der Pflanzen- und Tierwelt bis heute große Aufmerksamkeit genießen, wird Humboldts Beitrag zu der Entwicklung der modernen Landwirtschaft wenig beachtet. Während seines Aufenthalts in Lima erhielt er Proben von Guano, Vogelmist von den Chincha-Inseln vor der peruanischen Küste. Einige Proben, die er von dieser Reise zurückbrachte, wurden von Wissenschaftlern in Frankreich und Deutschland untersucht. Die Analysenergebnisse zeigten außerordentlich hohe Gehalte an Pflanzennährstoffen, insbesondere Stickstoff und Phosphor. In den folgenden Jahrzehnten wurde Guano zu einem bedeutsamen Düngemittel und Auslöser eines Booms in Europa und Peru. Die Auswirkungen dieser Entwicklung sind bis heute sichtbar und werden hier unter besonderer Beachtung von Phosphor beschrieben.
In Goethes privater Bibliothek im Goethehaus in Weimar ist Alexander von Humboldt mehrfach vertreten: durch persönlich übersandte Bücher, durch Broschüren und Grafiken. Einige dieser Publikationen Humboldts tragen handschriftliche Widmungen. Die Anmerkungen Goethes, seine Bearbeitungsspuren, die Bemerkungen im Tagebuch und nicht zuletzt der Briefwechsel geben Aufschluss über eine komplizierte Beziehung, die von Wohlwollen und von wissenschaftlichem Interesse an der Arbeit des anderen geprägt war, im Alter aber, insbesondere bei Humboldt, spürbar distanzierter wurde. Erstmals werden in diesem Beitrag alle handschriftlichen Widmungen Humboldts an Goethe abgebildet und die Publikationen Humboldts in Goethes Bibliothek in einen wissenschaftshistorischen und lebensgeschichtlichen Kontext gestellt.
Ever since our first research into Alexander von Humboldt's stay in Spain, the absence of an ensuing relationship between the wise Prussian and the Spanish Crown and Authorities had always surprised us. On starting new research, we found that indeed he sent his first work to Carlos IV from Rome accompanied by a letter of gratitude for the protection he had received during his American trip and submission to the Spanish Crown, which we now present. This first literary fruit of his voyage, which Alexander von Humboldt alluded to in the letter is the first instalment of his work Plantes Équinoxiales, Recueillies au Mexique, dans l’ile de Cuba, dans les provinces de Caracas, de Cumana etc., published in Paris in 1805.
Naturaleza y cultura
(2016)
El presente trabajo gira en torno al inexpugnable vínculo entre naturaleza y cultura y la 'no naturalidad' de la primera, producto de las milenarias intervenciones del hombre, subsumido bajo el término del 'antropoceno'. Los filósofos franceses Bruno Latour y Philippe Descola supieron destacar, aunque por caminos diferentes, la importancia de este nexo para asegurar la supervivencia del hombre; Bruno Latour centra sus reflexiones en la política de la naturaleza y Philippe Descola destaca el carácter ecológico de la naturaleza y la cultura. Sin embargo, ambos dejan de lado las literaturas del mundo y su capacidad de atesorar los diversos diseños del saber convivir entre hombre y naturaleza y las nociones de sustentabilidad. Descuella además la inspiración que Descola encuentra en la figura del gran erudito Alexander von Humboldt, quien en el siglo XIX ya daba fe de la relación inextricable entre naturaleza y cultura en innumerables testimonios, entre otros, el Chimborazo que, como cuadro global es representativo para entender que la naturaleza desde siempre ha sido cultura y la cultura es inimaginble sin la naturaleza.
Dieser Beitrag behandelt einen bisher unveröffentlichen Brief Alexander von Humboldts an Thomas Jefferson. Der Brief bietet uns einen aufschlussreichen Einblick in die persönlichen, politischen und wissenschaftlichen Netzwerke Humboldts und schließt eine Lücke in der Humboldt-Jefferson-Korrespondenz.
Für Margot Faak (1926–2015)
Am 14. Juni 2015 starb unsere Kollegin Margot Faak im 89. Lebensjahr. Wir erinnern an sie mit Worten des Abschieds von Eberhard Knobloch und dem Wiederabdruck eines Aufsatzes aus ihrer Feder von 1999.
Die Neuveröffentlichung erfolgt mit freundlicher Genehmigung der Alexander von Humboldt-Stiftung.
Der Text wurde in den Fußnoten durch einige aktuelle bibliographische und sachliche Angaben ergänzt.
HiN VII, 13 (2006) war Margot Faak zu ihrem 80. Geburtstag gewidmet. Das Heft enthält einen Lebenslauf und ein Verzeichnis ihrer Schriften.
Berlin, Oktober 2015
Regina Mikosch und Ingo Schwarz