2,144 research outputs found
Coexistence and Survival in Conservative Lotka-Volterra Networks
Analyzing coexistence and survival scenarios of Lotka-Volterra (LV) networks in which the total biomass is conserved is of vital importance for the characterization of long-term dynamics of ecological communities. Here, we introduce a classification scheme for coexistence scenarios in these conservative LV models and quantify the extinction process by employing the Pfaffian of the network's interaction matrix. We illustrate our findings on global stability properties for general systems of four and five species and find a generalized scaling law for the extinction time
Academic careers and the valuation of academics. A discursive perspective on status categories and academic salaries in France as compared to the U.S., Germany and Great Britain
Academic careers are social processes which involve many members of large populations over long periods of time. This paper outlines a discursive perspective which looks into how academics are categorized in academic systems. From a discursive view, academic careers are organized by categories which can define who academics are (subjectivation) and what they are worth (valuation). The question of this paper is what institutional categorizations such as status and salaries can tell us about academic subject positions and their valuation. By comparing formal status systems and salary scales in France with those in the U.S., Great Britain and Germany, this paper reveals the constraints of institutional categorization systems on academic careers. Special attention is given to the French system of status categories which is relatively homogeneous and restricts the competitive valuation of academics between institutions. The comparison shows that academic systems such as the U.S. which are characterized by a high level of heterogeneity typically present more negotiation opportunities for the valuation of academics. From a discursive perspective, institutional categories, therefore, can reflect the ways in which academics are valuated in the inter-institutional job market, by national bureaucracies or in professional oligarchies
Pathology of Echinococcosis
Infection of humans by the larval stage of the tapeworms Echinococcus granulosus sensu lato or Echinococcus multilocularis causes the life-threatening zoonoses cystic echinococcosis (CE) and alveolar echinococcosis (AE). Although cystic liver lesions are a hallmark of both diseases, course, prognosis, and patients' management decisively differ between the two. The wide and overlapping spectrum of morphologies and the limited availability of ancillary tools are challenges for pathologists to reliably diagnose and subtype echinococcosis. Here, we systematically and quantitatively recorded the pathologic spectrum in a clinically and molecularly defined echinococcosis cohort (138 specimens from 112 patients). Immunohistochemistry using a novel monoclonal antibody (mAbEmG3) was implemented, including its combined application with the mAbEm2G11. Six morphologic criteria sufficiently discriminated between CE and AE: size of smallest (CE/AE: >2/≤2 mm) and largest cyst (CE/AE: >25/≤25 mm), thickness of laminated layer (CE/AE: >0.15/≤0.15 mm) and pericystic fibrosis (CE/AE: >0.6/≤0.6 mm), striation of laminated layer (CE/AE: moderate-strong/weak), and number of cysts (CE/AE: ≤9/>9). Combined immunohistochemistry with mAbEm2G11 (E. multilocularis specific) and mAbEmG3 (reactive in AE and CE) was equally specific as and occasionally more sensitive than polymerase chain reaction. On the basis of these findings, we developed a diagnostic algorithm for the differential diagnosis of echinococcosis. In summary, we have not only identified the means to diagnose echinococcosis with greater certainty, but also defined morphologic criteria, which robustly discriminate between CE and AE. We expect our findings to improve echinococcosis diagnostics, especially of challenging cases, beneficially impacting the management of echinococcosis patients
Massive migration from the steppe is a source for Indo-European languages in Europe
We generated genome-wide data from 69 Europeans who lived between 8,000-3,000
years ago by enriching ancient DNA libraries for a target set of almost four
hundred thousand polymorphisms. Enrichment of these positions decreases the
sequencing required for genome-wide ancient DNA analysis by a median of around
250-fold, allowing us to study an order of magnitude more individuals than
previous studies and to obtain new insights about the past. We show that the
populations of western and far eastern Europe followed opposite trajectories
between 8,000-5,000 years ago. At the beginning of the Neolithic period in
Europe, ~8,000-7,000 years ago, closely related groups of early farmers
appeared in Germany, Hungary, and Spain, different from indigenous
hunter-gatherers, whereas Russia was inhabited by a distinctive population of
hunter-gatherers with high affinity to a ~24,000 year old Siberian6 . By
~6,000-5,000 years ago, a resurgence of hunter-gatherer ancestry had occurred
throughout much of Europe, but in Russia, the Yamnaya steppe herders of this
time were descended not only from the preceding eastern European
hunter-gatherers, but from a population of Near Eastern ancestry. Western and
Eastern Europe came into contact ~4,500 years ago, as the Late Neolithic Corded
Ware people from Germany traced ~3/4 of their ancestry to the Yamnaya,
documenting a massive migration into the heartland of Europe from its eastern
periphery. This steppe ancestry persisted in all sampled central Europeans
until at least ~3,000 years ago, and is ubiquitous in present-day Europeans.
These results provide support for the theory of a steppe origin of at least
some of the Indo-European languages of Europe
Das Tumormikromilieu bei Speicheldrüsenkarzinomen – mögliche Konsequenzen für neue Therapiekonzepte
Hintergrund
Speicheldrüsenkarzinome („salivary gland carcinomas“, SGC) sind seltene Tumoren, die aufgrund ihrer histologischen Vielfalt und den in Abhängigkeit vom Subtyp unterschiedlichen Krankheitsverläufen eine Herausforderung für Diagnostik und Therapie darstellen. Über die Zusammensetzung des Tumormikromilieus (TME) bei SGC ist bislang wenig bekannt. Ein umfassenderes Verständnis der relevanten molekularen Veränderungen und immunologischen Prozesse des Tumors sowie des umgebenden Stromas könnte dazu beitragen, die therapeutische Effizienz – beispielsweise durch eine adjuvante Immunmodulation – zu verbessern.
Methoden
In diesem Manuskript wurden Ergebnisse aus Studien zusammengefasst, die sich mit der Zusammensetzung des TME bei SGC beschäftigen.
Ergebnisse
Das Immunzellinfiltrat der verschiedenen Tumorentitäten ist unterschiedlich. Bei einem Drittel der SGC wurde eine Expression des Oberflächenzellrezeptors LAG3 („lymphocyte activation gene 3“) auf tumorinfiltrierenden Lymphozyten beobachtet. LAG3 inhibiert – ähnlich wie CTLA‑4 („cytotoxic T‑lymphocyte antigen 4“) und PD‑1 („programmed cell death 1 protein“) – die zelluläre Proliferation, Aktivierung und Homöostase von antitumoral wirksamen T‑Zellen. Höhere Expressionen sind dabei insbesondere bei den prognostisch ungünstigeren Entitäten wie den Speichelgangkarzinomen und Adenokarzinomen NOS („not otherwise specified“) zu beobachten.
Schlussfolgerungen
LAG3 ist insbesondere bei aggressiven Entitäten und fortgeschrittenen Tumoren nachzuweisen. Folglich könnte eine Therapie mit LAG3-Inhibitoren eine Therapie bei fortgeschrittenen und metastasierten SGC unterstützen
Der Furz des Sancho Panza oder "Don Quijote" als komischer Roman
Wie kein zweiter Roman zieht der "Don Quijote" von Miguel de Cervantes seit nunmehr vier Jahrhunderten Generationen von Lesern immer wieder neu in seinen Bann. Abgefasst im Spanien des frühen 17. Jahrhunderts, das zu jener Zeit die Geschicke Europas wesentlich mitbestimmte, wurde der Roman bald zum Inbegriff der spanischen Literatur und Kultur. Von Madrid aus hat er auf den Rest Europas ausgestrahlt und Denker, Dichter, Künstler, Komponisten und später auch Filmemacher zur Auseinandersetzung mit ihm angeregt.
Die acht Beiträge des Bandes erkunden zentrale Aspekte des cervantinischen Romans und gehen seiner Rezeption und Verarbeitung in Literatur, Kunst, Film und Musik im europäischen Kontext nach.Like no other novel, the "Don Quixote" by Miguel de Cervantes has fascinated readers time and again for four centuries. Written in Spain in the early 17th century, which at that time played a major role in shaping the destiny of Europe, the novel soon became the epitome of Spanish literature and culture. From Madrid he started affecting the rest of Europe and inspired thinkers, poets, artists, composers and later also filmmakers.
The volume\u27s eight contributions explore central aspects of the Cervantine novel and explore its reception and processing in literature, art, film and music in the European context
Evaluation of four Cameroonian medicinal plants for anticancer, antigonorrheal and antireverse transcriptase activities
Methanol extracts from the leaves, bark and roots of four Cameroonian medicinal plants, Bersama engleriana, Cupressus lusitanica, Vitellaria paradoxa and Guibourtia tessmannii were tested for their in vitro cytotoxicity, antigonorrheal and antireverse transcriptase activities. The XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt) assay, the dilution method and reverse transcriptase (RT) assay were used for the investigations. Preliminary phytochemical analysis of the extracts was also conducted using standard methods. Results showed that all extracts contained compounds belonging to the classes of phenols and terpenoids. They were also able to reduce in dose dependent manner, the proliferation of the cancer THP-1, DU145, HeLa, MCF-7, HepG2 and the normal Vero cells. IC50 values below 30 ÎĽg/ml were noted with extract from the three parts of B. engleriana on at least two of the five studied cancer cell lines, the lowest value of 5.9 ÎĽg/ml being obtained with sample from the bark. IC50 values below 30 ÎĽg/ml were also recorded with extracts from the leaves (on HeLa cells) and bark (on MCF-7) of G. tessmanii, and that from the bark of C. lusitanica on MCF-7. Extracts from B. engleriana and those from the bark of V. paradoxa gave the minimal inhibitory concentrations (MIC) values below 100 ÎĽg/ml on most of the 10 tested Nesseria gonorrhoeae strains. Extracts from B. engleriana also inhibited more than 80% the activity of the Human Immuno-deficiency Virus (HIV) enzyme. Finally, the results of the present study provide baseline information for the use of B. engleriana, C. lusitanica, G. tessmanii, V. paradoxa.http://www.elsevier.com/locate/etapnf201
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