3,857 research outputs found
Identification of genes induced by the conceptus in the bovine endometrium during the pre-implantation period
An intact embryo-maternal communication in the pre-implantation period is particularly critical for establishment of pregnancy and early embryonic losses have been identified as the major cause of reproductive failure in cattle. Thus, to gain deeper insight into this complex embryo-maternal crosstalk, a combination of subtracted cDNA libraries and cDNA array hybridization was applied to identify mRNAs differentially regulated genes in the bovine endometrium by the presence of a conceptus. One cDNA library was constructed according the suppression subtractive hybridization method (Diatchenko et al., 1996) with minor modifications; a second cDNA library was constructed of subtracted cDNA purchased from the vertis Biotechnologie AG. As biological model endometrial tissue samples of monozygotic twins (generated by embryo splitting) collected at day 18 of gestation were used, which is a unique possibility to eliminate genetic variability as a factor potentially affecting the results of gene expression analyses. Array hybridization was carried out using 33P-labeled cDNA probes obtained from five monozygotic twin pairs. Sequence analysis revealed 87 different genes or mRNAs, respectively, which displayed a difference in signal intensity of 2.0 fold or more in at least four out of five twin pairs. Eighty genes corresponded to genes with known or inferred function, either the bovine gene or the human orthologue. For 7 mRNAs a match with bovine ESTs was obtained only. For nine selected genes the expression in the bovine endometrium was quantified by the use of quantitative real-time RT-PCR to verify the results obtained by array hybridization and to perform more precise quantitative measurements for these genes. Overall, the results of array hybridization and real-time RT-PCR correlated very well.
Almost half of the identified genes are known to be stimulated by type I interferons reflecting the response to IFNt, which is the pregnancy recognition signal in ruminants. Of particular interest among the interferon stimulated genes is ISG15, one of the most markedly upregulated genes in the present study, which is hypothesized to stabilize intracellular endometrial proteins through conjugation processes. For the ISG15ylation system mRNAs of four potential components (IFITM1, IFITM3, HSXIAPAF1, and DTX3L) were found in addition to ISG15 and UBE1L, and in situ hybridization revealed similar mRNA expression patterns of these genes. It is therefore suggested, that modification of endometrial proteins through ISG15ylation plays a fundamental role in the IFNt signaling.
A classification of the identified genes according to their assignment to Gene Ontologies revealed the orchestrated interaction of various processes and mechanisms with regard to the preparation of the maternal endometrium for embryonic implantation. As particular interesting, genes were identified involved in modulation of the maternal immune system at the humoral and cellular level, cell adhesion, cell communication, regulation of transcription, cell differentiation, cell growth, and cell proliferation. These findings underline that an intense embryo-maternal dialogue takes place during the pre-implantation period, which culminates in a receptive endometrium prepared for implantation of the conceptus.
To conclude, this is the first study of its kind for cattle in the pre-implantation stage of embryonic development and revealed the orchestrated upregulation of genes important for embryonic implantation during the pre-implantation period in the bovine endometrium. The presented results provide new starting points for detailed investigations of the embryo-maternal dialogue by which the endometrium is prepared for conceptus attachment
Trade integration,restructuring and global imbalances --A tale of two countries
China is widely seen as one of the sources of global macroeconomic imbalances. Its persistent current account surplus and capital exports to the United States are even cited as one of the causes of the global financial crisis. The most common explanation traces China's current account surplus to a mismatch between saving and investment due to inefficiently low domestic demand. We challenge this explanation. Our argument rests on an analogy that we construct between two countries generally thought to be very different: Russia and China. Russia, a raw materials exporting country, has been running current account surpluses similar to China's in relation to GDP. As for most raw materials exporting countries this is considered normal, reflecting efficient reinvestment of wealth from natural resources in financial assets. We show that a similar efficiency argument can be constructed for China, although the nature of wealth that is reinvested in financial assets is different in the two countries. Our analysis implies that China's current account surpluses can be expected to disappear over the long horizon – although the time when this will happen may still be very far away. Moreover, an appreciation of the Chinese currency may not have the desired effect of mitigating the country's current account surplus as a weakening in competitiveness is counterbalanced by a strengthening of investment motives.trade structures,trade imbalances, current account imbalances, outside assets
Trade integration, restructuring and global imbalances: A tale of two countries
China is widely seen as one of the sources of global macroeconomic imbalances. Its persistent current account surplus and capital exports to the United States are even cited as one of the causes of the global financial crisis. The most common explanation traces China's current acca ount surplus to a mismatch between saving and investment due to inefficiently low domestic demand. We challenge this explanation. Our argument rests on an analogy that we construct between two countries generally thought to be very different: Russia and China. Russia, a raw materials exporting country, has been running current account surpluses similar to China's in relation to GDP. As for most raw materials exporting countries this is considered normal, reflecting efficient reinvestment of wealth from natural resources in financial assets. We show that a similar efficiency argument can be constructed for China, although the nature of wealth that is reinvested in financial assets is different in the two countries. Our analysis implies that China's current account surpluses can be expected to disappear over the long horizon - although the time when this will happen may still be very far away. Moreover, an appreciation of the Chinese currency may not have the desired effect of mitigating the country's current account surplus as a weakening in competitiveness is counterbalanced by a strengthening of investment motives. --
Type I Interferon Induction in Cutaneous DNA Damage Syndromes
Type I interferons (IFNs) as part of the innate immune system have an outstanding
importance as antiviral defense cytokines that stimulate innate and adaptive immune
responses. Upon sensing of pattern recognition particles (PRPs) such as nucleic acids,
IFN secretion is activated and induces the expression of interferon stimulated genes
(ISGs). Uncontrolled constitutive activation of the type I IFN system can lead to
autoinflammation and autoimmunity, which is observed in autoimmune disorders such
as systemic lupus erythematodes and in monogenic interferonopathies. They are caused
by mutations in genes which are involved in sensing or metabolism of intracellular nucleic
acids and DNA repair. Many authors described mechanisms of type I IFN secretion upon
increased DNA damage, including the formation of micronuclei, cytosolic chromatin
fragments and destabilization of DNA binding proteins. Hereditary cutaneous DNA
damage syndromes, which are caused by mutations in proteins of the DNA repair,
share laboratory and clinical features also seen in autoimmune disorders and
interferonopathies; hence a potential role of DNA-damage-induced type I IFN secretion
seems likely. Here, we aim to summarize possible mechanisms of IFN induction in
cutaneous DNA damage syndromes with defects in the DNA double-strand repair and
nucleotide excision repair. We review recent publications referring to Ataxia
teleangiectasia, Bloom syndrome, Rothmund–Thomson syndrome, Werner syndrome,
Huriez syndrome, and Xeroderma pigmentosum. Furthermore, we aim to discuss the role
of type I IFN in cancer and these syndromes
Perspectives for NATO-Russia relations: forms of confrontation dominate - but dialogue not excluded
Institutional relations between NATO and Russia have been suspended since the illegal annexation of Crimea in 2014 and the war in eastern Ukraine. Conflicting ideas about Euro-Atlantic security have left the relationship deeply and lastingly damaged. This makes it all the more important to gain clarity about the determining factors and perspectives of the relationship. Its evolution over the coming five to ten years will also be shaped by future events, such as the NATO summit in Warsaw in 2016 and elections in the United States in 2016 and Russia in 2016 and 2018. External developments will play a significant role, too. (author's abstract
Ensuring Ukraine's security: from ad hoc support to long-term security guarantees as NATO member
Since February 2022, Ukraine has been defending itself against yet another Russian war of aggression. Now that immediate support - military, diplomatic, financial and humanitarian - for Ukraine has improved, the country's long-term security needs to be addressed. Looking ahead, security commitments should be built on political, economic and military pillars. NATO membership is essential for Ukraine's security, but it is also in the geostrategic and normative interests of the Alliance, even if it is a risky, long-term and difficult endeavour. At the 2023 summit in Vilnius, NATO recognized that Ukraine’s future is in the Alliance but remained vague about the conditions to join. Yet, other agreements announced on the margins of the summit by the G7 and individual states expand the support for Ukraine. Framed as steps to increase Ukraine’s security, these should accompany the transition from current security support to future guarantees. (author's abstract
Kompromiss im Solarstreit zwischen EU und China: Aber die fundamentalen Ungleichgewichte bleiben bestehen
Der Handelsstreit um Solarmodule zwischen der EU und China wurde Ende Juli 2013 mit einem Kompromiss beigelegt. Die Autoren stellen dar, welche Folgen dies auf Preise, Mengen und die Verteilung der Marktanteile hat. Sie sind der Auffassung, dass es zu weiteren Verzerrungen des Marktes kommen wird, weil weiterhin in allen Ländern - nur teilweise ökologisch motivierte - Subventionen üblich sind. Die extremen Handelsungleichgewichte kommen allerdings vor allem dadurch zustande, dass die EU die Nachfrage und China die Produktion subventioniert. Ein globaler Lösungsansatz wäre erforderlich.At the end of July 2013 the photovoltaic (PV) trade conflict between China and the European Union was resolved through a compromise whose key elements are price and quantity undertakings promised by China. A minimum price and a maximum export quantity should help to calm PV markets for the time being. Yet the fundamental disequilibria which led to the trade conflict persist. China needs to address its huge domestic excess capacity by reducing subsidies for PV production while vigorously promoting installation. Industrial countries need to address the mismatch between national PV subsidisation policies and the dynamics of global PV markets. If unresolved, further trade conflicts will be inevitable. In solving their bilateral problems, China and the EU have largely bypassed the WTO regime for conflict resolution, thus further revealing the weaknesses of this regime
Application of Remote Sensing Data for Locust Research and Management-A Review
Recently, locust outbreaks around the world have destroyed agricultural and natural vegetation and caused massive damage endangering food security. Unusual heavy rainfalls in habitats of the desert locust (Schistocerca gregaria) and lack of monitoring due to political conflicts or inaccessibility of those habitats lead to massive desert locust outbreaks and swarms migrating over the Arabian Peninsula, East Africa, India and Pakistan. At the same time, swarms of the Moroccan locust (Dociostaurus maroccanus) in some Central Asian countries and swarms of the Italian locust (Calliptamus italicus) in Russia and China destroyed crops despite developed and ongoing monitoring and control measurements. These recent events underline that the risk and damage caused by locust pests is as present as ever and affects 100 million of human lives despite technical progress in locust monitoring, prediction and control approaches. Remote sensing has become one of the most important data sources in locust management. Since the 1980s, remote sensing data and applications have accompanied many locust management activities and contributed to an improved and more effective control of locust outbreaks and plagues. Recently, open-access remote sensing data archives as well as progress in cloud computing provide unprecedented opportunity for remote sensing-based locust management and research. Additionally, unmanned aerial vehicle (UAV) systems bring up new prospects for a more effective and faster locust control. Nevertheless, the full capacity of available remote sensing applications and possibilities have not been exploited yet. This review paper provides a comprehensive and quantitative overview of international research articles focusing on remote sensing application for locust management and research. We reviewed 110 articles published over the last four decades, and categorized them into different aspects and main research topics to summarize achievements and gaps for further research and application development. The results reveal a strong focus on three species-the desert locust, the migratory locust (Locusta migratoria), and the Australian plague locust (Chortoicetes terminifera)-and corresponding regions of interest. There is still a lack of international studies for other pest species such as the Italian locust, the Moroccan locust, the Central American locust (Schistocerca piceifrons), the South American locust (Schistocerca cancellata), the brown locust (Locustana pardalina) and the red locust (Nomadacris septemfasciata). In terms of applied sensors, most studies utilized Advanced Very-High-Resolution Radiometer (AVHRR), Satellite Pour l'Observation de la Terre VEGETATION (SPOT-VGT), Moderate-Resolution Imaging Spectroradiometer (MODIS) as well as Landsat data focusing mainly on vegetation monitoring or land cover mapping. Application of geomorphological metrics as well as radar-based soil moisture data is comparably rare despite previous acknowledgement of their importance for locust outbreaks. Despite great advance and usage of available remote sensing resources, we identify several gaps and potential for future research to further improve the understanding and capacities of the use of remote sensing in supporting locust outbreak- research and management
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