Chinas militärische Entwicklung: Modernisierung und Internationalisierung der Streitkräfte

'Anlässlich des 60. Jahrestages der Gründung der Volksrepublik China und der zur Feier dessen durchgeführten, umfangreichen Militärparade am 1. Oktober 2009 wird in der vorliegenden Studie die Entwicklung des chinesischen Militärs - der größten Berufsarmee der Welt - entlang der folgenden Leitfragen untersucht: Welche programmatischen Richtlinien gibt die KPCh für den Verteidigungssektor des wiedererstarkten modernen China vor? Welche strategischen Ziele lassen sich aus den bisherigen Veränderungen ablesen? Wie sind die militärischen Fortschritte politisch einzuordnen und zu bewerten? Welche Rolle spielen dabei die zunehmenden internationalen Aktivitäten der chinesischen Streitkräfte? Es lässt sich feststellen, dass die Modernisierung des Militärs in einen übergreifenden politischen Anpassungsprozess eingeordnet wird, mit dem China den sicherheitspolitischen Gegebenheiten des 21. Jahrhunderts gerecht werden will. Die umfangreichen Kapazitäten aus der Ära des Kalten Krieges werden schrittweise angepasst und qualitativ aufgewertet, um internationale Friedensmissionen sowie humanitäre Hilfseinsätze bewältigen und bei militärischen Konflikten im Zeitalter des informationstechnologischen Wettstreits bestehen zu können. Die Grundausrichtung der Volksbefreiungsarmee ist dabei derzeit noch als eher defensiv zu bewerten, auch wenn im Bereich der Nuklear-, Weltraum-, Luft- und Seestreitkräfte das offensive Potential wächst. Gleichzeitig geht der rasante Anstieg bei Chinas militärischen Fähigkeiten bislang noch nicht mit einer ausreichenden politischen Kommunikation einher. Eine Erhöhung der sicherheits- und militärpolitischen Transparenz durch die chinesische Führung könnte dazu beitragen, Irritationen bei anderen Staaten zu vermeiden.' (Autorenreferat)'The steady rise in China's defence budget over recent years naturally stokes the speculation. From just Dollar 9.8 billion in 1997 it more than quadrupled within a decade, according to the official figures, to reach Dollar 46.8 billion by 2007 (although the proportion of annual GDP rose by just 0.29 percentage points over the same period). Beijing's official defence budget for 2009 is Dollar 70.2 billion, but the real level of Chinese military spending is disputed. Because they leave important expenditures on strategic capabilities and military space programmes unaccounted for, the official figures say little about the actual state of China's armed forces (PLA). The PLA is still a fundamentally defensive force, although its offensive potential is growing in the fields of nuclear weapons and space-based systems, as well as air and naval forces. Military modernisation has progressed furthest in the realm of the strategic forces and the navy, while the greatest deficits remain in the air force, where a lack of force multipliers such as reconnaissance aircraft and aerial refuelling tankers is the main obstacle to greater strength and force projection. The Western arms embargo ensures that the import of such force multipliers and access to the relevant technologies remain restricted. If it is in the interests of the EU and the United States to deny China access to these technologies at least in the short to medium term, the embargo will have to be maintained on key technologies. The rapid expansion of China's military capabilities has not thus far been accompanied by adequate political communication. An increase in transparency on security and military matters could help to reassure other states. Effective international integration would support this process.' (author's abstract)

Independent causal contributions of alpha- and beta-band oscillations during movement selection

To select a movement, specific neuronal populations controlling particular features of that movement need to be activated, whereas other populations are downregulated. The selective (dis)inhibition of cortical sensorimotor populations is governed by rhythmic neural activity in the alpha (8–12 Hz) and beta (15–25 Hz) frequency range. However, it is unclear whether and how these rhythms contribute independently to motor behavior. Building on a recent dissociation of the sensorimotor alpha- and beta-band rhythms, we test the hypothesis that the beta-band rhythm governs the disinhibition of task-relevant neuronal populations, whereas the alpha-band rhythm suppresses neurons that may interfere with task performance. Cortical alpha- and beta-band rhythms were manipulated with transcranial alternating current stimulation (tACS) while human participants selected how to grasp an object. Stimulation was applied at either 10 or 20 Hz and was imposed on the sensorimotor cortex contralaterally or ipsilaterally to the grasping hand. In line with task-induced changes in endogenous spectral power, the effect of the tACS intervention depended on the frequency and site of stimulation. Whereas tACS stimulation generally increased movement selection times, 10 Hz stimulation led to relatively faster selection times when applied to the hemisphere ipsilateral to the grasping hand, compared with other stimulation conditions. These effects occurred selectively when multiple movements were considered. These observations functionally differentiate the causal contribution of alpha- and beta-band oscillations to movement selection. The findings suggest that sensorimotor beta-band rhythms disinhibit task-relevant populations, whereas alpha-band rhythms inhibit neuronal populations that could interfere with movement selection

Type of headache at onset and risk for complications in reversible cerebral vasoconstriction syndrome

Background: In a recent Italian study, 30% of patients with reversible cerebral vasoconstriction syndrome (RCVS) presented without thunderclap headache (TCH), and tended to present more severe forms of RCVS than patients with TCH. We aimed to analyze the risk for complications of RCVS in patients with and without TCH at onset. Methods: In a pooled cohort of 345 French patients with RCVS, we compared patients with and without TCH at onset regarding rates of neurological complications, and the functional outcome at 3 months. Results: As compared to the 281 patients with TCH at onset, the 64 patients without TCH had a higher risk for any neurological complication (61% vs. 24%, OR 4.9, 95% CI 2.8-8.7, p < 0.001). The association was strongest for cervical artery dissections (28% vs. 5%, OR 8.1, 95% CI 3.7-17.6, p < 0.001), followed by posterior reversible encephalopathy syndrome (17% vs. 3%, OR 7.1, 95% CI 2.7-18.4, p < 0.001), seizures (9% vs. 2.5%, OR 4.1, 95% CI 1.3-12.5, p = 0.019), and subarachnoid hemorrhage (41% vs. 16%, OR 3.5, 95% CI 1.9-6.3, p < 0.001). In multivariable analysis, the risk for any neurological complication remained significantly elevated in the absence of TCH (OR 3.5, 95% CI 1.8-6.8, p < 0.001). The functional outcome was equal in both groups, with a modified Rankin scale score of 0-1 in ≥90% of patients. Conclusions: Absence of TCH at onset might predict a higher risk of complications in RCVS. Our results warrant further multicentric studies to prove this finding

Dimethylarginine dimethylaminohydrolase-2 deficiency promotes vascular regeneration and attenuates pathological angiogenesis

AbstractIschemia-induced angiogenesis is critical for tissue repair, but aberrant neovascularization in the retina causes severe sight impairment. Nitric oxide (NO) has been implicated in neovascular eye disease because of its pro-angiogenic properties in the retina. Nitric oxide production is inhibited endogenously by asymmetric dimethylarginines (ADMA and L-NMMA) which are metabolized by dimethylarginine dimethylaminohydrolase (DDAH) 1 and 2. The aim of this study was to determine the roles of DDAH1, DDAH2, ADMA and L-NMMA in retinal ischemia-induced angiogenesis. First, DDAH1, DDAH2, ADMA and L-NMMA levels were determined in adult C57BL/6J mice. The results obtained revealed that DDAH1 was twofold increased in the retina compared to the brain and the choroid. DDAH2 expression was approximately 150 fold greater in retinal and 70 fold greater in choroidal tissue compared to brain tissue suggesting an important tissue-specific role for DDAH2 in the retina and choroid. ADMA and L-NMMA levels were similar in the retina and choroid under physiological conditions. Next, characterization of DDAH1+/− and DDAH2−/− deficient mice by in vivo fluorescein angiography, immunohistochemistry and electroretinography revealed normal neurovascular function compared with wildtype control mice. Finally, DDAH1+/− and DDAH2−/− deficient mice were studied in the oxygen-induced retinopathy (OIR) model, a model used to emulate retinal ischemia and neovascularization, and VEGF and ADMA levels were quantified by ELISA and liquid chromatography tandem mass spectrometry. In the OIR model, DDAH1+/− exhibited a similar phenotype compared to wildtype controls. DDAH2 deficiency, in contrast, resulted in elevated retinal ADMA which was associated with attenuated aberrant angiogenesis and improved vascular regeneration in a VEGF independent manner. Taken together this study suggests, that in retinal ischemia, DDAH2 deficiency elevates ADMA, promotes vascular regeneration and protects against aberrant angiogenesis. Therapeutic inhibition of DDAH2 may therefore offer a potential therapeutic strategy to protect sight by promoting retinal vascular regeneration and preventing pathological angiogenesis

Ultrafast optical circuit switching for data centers using integrated soliton microcombs

Networks inside current data centers comprise a hierarchy of power-hungry electronic packet switches interconnected via optical fibers and transceivers. As the scaling of such electrically-switched networks approaches a plateau, a power-efficient solution is to implement a flat network with optical circuit switching (OCS), without electronic switches and a reduced number of transceivers due to direct links among servers. One of the promising ways of implementing OCS is by using tunable lasers and arrayed waveguide grating routers. Such an OCS-network can offer high bandwidth and low network latency, and the possibility of photonic integration results in an energy-efficient, compact, and scalable photonic data center network. To support dynamic data center workloads efficiently, it is critical to switch between wavelengths in sub nanoseconds (ns). Here we demonstrate ultrafast photonic circuit switching based on a microcomb. Using a photonic integrated Si3N4 microcomb in conjunction with semiconductor optical amplifiers (SOAs), sub ns (< 500 ps) switching of more than 20 carriers is achieved. Moreover, the 25-Gbps non-return to zero (NRZ) and 50-Gbps four-level pulse amplitude modulation (PAM-4) burst mode transmission systems are shown. Further, on-chip Indium phosphide (InP) based SOAs and arrayed waveguide grating (AWG) are used to show sub-ns switching along with 25-Gbps NRZ burst mode transmission providing a path toward a more scalable and energy-efficient wavelength-switched network for future data centers.Comment: 11 pages, 6 figure

Immunosuppressive therapy after solid-organ transplantation: does the INTERMED identify patients at risk of poor adherence?

Lack of adherence to medication is a trigger of graft rejection in solid-organ transplant (SOT) recipients. This exploratory study aimed to assess whether a biopsychosocial evaluation using the INTERMED instrument before transplantation could identify SOT recipients at risk of suboptimal post-transplantation adherence to immunosuppressant drugs. We hypothesized that complex patients (INTERMED&gt;20) might have lower medication adherence than noncomplex patients (INTERMED≤20). Each patient eligible for transplantation at the University Hospital of Lausanne, Switzerland, has to undergo a pre-transplantation psychiatric evaluation. In this context the patient was asked to participate in our study. The INTERMED was completed pre-transplantation, and adherence to immunosuppressive medication was monitored post-transplantation by electronic monitors for 12 months. The main outcome measure was the implementation and persistence to two calcineurin inhibitors, cyclosporine and tacrolimus, according to the dichotomized INTERMED score (&gt;20 or ≤20). Among the 50 SOT recipients who completed the INTERMED, 32 entered the study. The complex (N=11) and noncomplex patients (N=21) were similar in terms of age, sex and transplanted organ. Implementation was 94.2% in noncomplex patients versus 87.8% in complex patients (non-significant p-value). Five patients were lost to follow-up: one was non-persistent, and four refused electronic monitoring. Of the four patients who refused monitoring, two were complex and withdrew early, and two were noncomplex and withdrew later in the study. Patients identified as complex pre-transplant by the INTERMED tended to deviate from their immunosuppressant regimen, but the findings were not statistically significant. Larger studies are needed to evaluate this association further, as well as the appropriateness of using a nonspecific biopsychosocial instrument such as INTERMED in highly morbid patients who have complex social and psychological characteristics

The non-coding RNA TERRA is a natural ligand and direct inhibitor of human telomerase

Telomeres, the physical ends of eukaryotes chromosomes are transcribed into telomeric repeat containing RNA (TERRA), a large non-coding RNA of unknown function, which forms an integral part of telomeric heterochromatin. TERRA molecules resemble in sequence the telomeric DNA substrate as they contain 5′-UUAGGG-3′ repeats near their 3′-end which are complementary to the template sequence of telomerase RNA. Here we demonstrate that endogenous TERRA is bound to human telomerase in cell extracts. Using in vitro reconstituted telomerase and synthetic TERRA molecules we demonstrate that the 5′-UUAGGG-3′ repeats of TERRA base pair with the RNA template of the telomerase RNA moiety (TR). In addition TERRA contacts the telomerase reverse transcriptase (TERT) protein subunit independently of hTR. In vitro studies further demonstrate that TERRA is not used as a telomerase substrate. Instead, TERRA acts as a potent competitive inhibitor for telomeric DNA in addition to exerting an uncompetitive mode of inhibition. Our data identify TERRA as a telomerase ligand and natural direct inhibitor of human telomerase. Telomerase regulation by the telomere substrate may be mediated via its transcription