On the embeddability of certain infinitely divisible probability measures on Lie groups

We describe certain sufficient conditions for an infinitely divisible probability measure on a class of connected Lie groups to be embeddable in a continuous one-parameter convolution semigroup of probability measures. (Theorem 1.3). This enables us in particular to conclude the embeddability of all infinitely divisible probability measures on certain Lie groups, including the so called Walnut group (Corollary 1.5). The embeddability is concluded also under certain other conditions (Corollary 1.4 and Theorem 1.6).Comment: 24 page

Ultrafast Enhancement of Ferromagnetism via Photoexcited Holes in GaMnAs

We report on the observation of ultrafast photo-enhanced ferromagnetism in GaMnAs. It is manifested as a transient magnetization increase on a 100-ps time scale, after an initial sub-ps demagnetization. The dynamic magnetization enhancement exhibits a maximum below the Curie temperature Tc and dominates the demagnetization component when approaching Tc. We attribute the observed ultrafast collective ordering to the p-d exchange interaction between photoexcited holes and Mn spins, leading to a correlation-induced peak around 20K and a transient increase in Tc.Comment: 4 page

The Computational Power of Optimization in Online Learning

We consider the fundamental problem of prediction with expert advice where the experts are "optimizable": there is a black-box optimization oracle that can be used to compute, in constant time, the leading expert in retrospect at any point in time. In this setting, we give a novel online algorithm that attains vanishing regret with respect to $N$ experts in total $\widetilde{O}(\sqrt{N})$ computation time. We also give a lower bound showing that this running time cannot be improved (up to log factors) in the oracle model, thereby exhibiting a quadratic speedup as compared to the standard, oracle-free setting where the required time for vanishing regret is $\widetilde{\Theta}(N)$. These results demonstrate an exponential gap between the power of optimization in online learning and its power in statistical learning: in the latter, an optimization oracle---i.e., an efficient empirical risk minimizer---allows to learn a finite hypothesis class of size $N$ in time $O(\log{N})$. We also study the implications of our results to learning in repeated zero-sum games, in a setting where the players have access to oracles that compute, in constant time, their best-response to any mixed strategy of their opponent. We show that the runtime required for approximating the minimax value of the game in this setting is $\widetilde{\Theta}(\sqrt{N})$, yielding again a quadratic improvement upon the oracle-free setting, where $\widetilde{\Theta}(N)$ is known to be tight

Weight loss surgery in the elderly: is this the future

The UK population is ageing rapidly, and the proportion of people living with obesity is increasing. Obesity is a risk factor for diabetes, coronary artery disease, stroke and cancer. Older patients are admitted for obesity related complications at a similar rate compared to younger patients. However, the operations for people over 70-years are extremely infrequent. In this scoping review we summarize the recent data on bariatric operations in people over 70-years and the possible risk benefit ratio of bariatric surgery for this population

Short- versus Long-term Dual Anti-platelet Therapy (DAPT) in Secondary Prevention for Ischaemic Stroke – A Network Metanalysis

Aim: This review aimed to compare the efficacy and safety of short-term (==1 year) dual-antiplatelet therapy (DAPT) in secondary prevention for ischaemic stroke. Methods and results: We searched MEDLINE, EMBASE (Ovid), PubMed, Cochrane Library, ClinicalTrials.gov and Google Advanced Search for randomised controlled trials. The population consisted of patients with recent ischaemic stroke or transient ischaemic attack. The intervention was DAPT with a combination of aspirin, clopidogrel and dipyridamole compared to either aspirin or clopidogrel in monotherapy. The primary outcome was the rate of all recurrent stroke (ischaemic and haemorrhagic). Secondary outcomes were ischaemic stroke, all bleeding, severe bleeding, all-cause death, cardiovascular death and myocardial infarction. Data were pooled by network metanalysis and pairwise metanalyses. Sixteen studies with 55,261 participants were included. Compared to aspirin, DAPT with aspirin clopidogrel decreased the risk of recurrent stroke (short-term OR 0.67, 95%CI 0.58-0.77; long-term OR 0.84, 95%CI 0.70- 1.01) at the expense of increased risk of bleeding (short-term OR 1.76, 95%CI 1.26-2.46; long-term OR 2.25, 95%CI 1.97-2.57). DAPT with aspirin clopidogrel and clopidogrel in monotherapy had similar long-term risk of recurrent stroke (OR 0.98, 95%CI 0.83-1.14), but DAPT was associated with increased risk of bleeding (OR 2.77, 95%CI 2.21-3.46). Network metanalysis showed that short-term aspirin clopidogrel DAPT had the best risk-benefit profile, followed by long-term aspirin clopidogrel DAPT and clopidogrel alone. Aspirin dipyridamole DAPT was less effective. Conclusion: Short-term DAPT had better risk-benefit profile than long-term DAPT.European Society of Cardiology (ESC)NIH

Ultrafast dynamics of coherences in the quantum Hall system

Using three-pulse four-wave-mixing optical spectroscopy, we study the ultrafast dynamics of the quantum Hall system. We observe striking differences as compared to an undoped system, where the 2D electron gas is absent. In particular, we observe a large off-resonant signal with strong oscillations. Using a microscopic theory, we show that these are due to many-particle coherences created by interactions between photoexcited carriers and collective excitations of the 2D electron gas. We extract quantitative information about the dephasing and interference of these coherences.Comment: 4 pages, 4 figures, to be published in Phys. Rev. Let

Disiplin Kerja Dalam Perspektif Islam Pada Karyawan Perpustakaan Universitas Muhammadiyah Surakarta

Pada dasarnya sikap disiplin bekerja pada karyawan yaitu bekerja dengan menaati aturan-aturan yang ada pada organisasi atau sistem kerja yang telah ditetapkan oleh perpustakaan dimana karyawan harus bisa bekerja sesuai aturan. Hal ini apabila dilihat dalam pandangan islam dimana seseorang yang bisa bekerja secara disiplin berarti sudah dapat melaksanakan amanah yang telah diberikan oleh orang banyak dengan baik. Dimana seorang yang bekerja secara berorganisasi menghendaki akan perubahan dan mencapai tujuan yang telah direncanakan. Penelitian ini bertujuan untuk mengetahui nilai-nilai yang melandasi disiplin kerja dalam perspektif Islam pada karyawan perpustakaan Universitas Muhammadiyah Surakarta. Dari tujuan penelitian tersebut muncul pertanyaan penelitian : “Nilai-nilai apa saja yang melandasi disiplin kerja dalam perspektif Islam pada karyawan perpustakaan Universitas Muhammadiyah Surakarta?”. Subjek dalam penelitian ini adalah karyawan perpustakaan Universitas Muhammadiyah Surakarta yang berjumlah 7 orang. Metode yang digunakan dalam penelitian ini adalah metode Kualitatif dengan alat pengumpulan data interview, observasi dan dokumentasi. Teknik analisis data yang digunakan dalam penelitian ini adalah deskriptif naratif. Berdasarkan analisis data diperoleh bahwa ketika bekerja sebisa mungkin datang ketempat kerja itu dengan tepat waktu sesuai dengan peraturan yang telah ditetapkan dan selalu mentaati segala peraturan yang ada serta melaksanakan tanggung jawab dan amanah yang telah diberikannya. Segala sesuatu apabila dikerjakan dengan tepat waktu maka akan bisa bermanfaat dengan baik serta bisa sesuai dengan peraturan yang telah ditetapkan oleh pihak organisasi. Bekerja apabila berkomitmen pada ajaran Agama Islam maka segalanya akan bisa dikerjakan dengan tepat waktu seperti melaksanakan sholat dengan tepat waktu serta ketika bekerja dengan memiliki niat untuk beribadah. Selain itu bekerja bukan hanya selalu tepat waktu tetapi juga harus bisa memiliki rasa tanggung jawab terhadap pekerjaan serta terhadap amanah yang telah diberikan agar pekerjaan bisa terlaksanakan dengan baik sesuai dengan aturan yang telah ditetapkan oleh organisasi. Kemudian ketika bekerja harus bisa memiliki sikap dan kepribadian yang baik dengan menunjukkan keteladanan dalam melaksanakan tugas seperti memiliki rasa empati yaitu merasakan apa yang dirasakan orang lain, hal ini bertujuan ketika bekerja tidak mengecewakan pengunjung maupun pimpinan. Ketika bekerja juga harus bisa saling menghormati dan menghargai agar terjalin kerjasama yang baik antar teman kerja dan pimpinan kerja

Observation of inter-Landau-level quantum coherence in semiconductor quantum wells

Using three-pulse four-wave-mixing femtosecond spectroscopy, we excite a non-radiative coherence between the discrete Landau levels of an undoped quantum well and study its dynamics. We observe quantum beats that reflect the time evolution of the coherence between the two lowest Landau level magnetoexcitons. We interpret our observations using a many-body theory and find that the inter Landau level coherence decays with a new time constant, substantially longer than the corresponding interband magnetoexciton dephasing times. Our results indicate a new intraband excitation dynamics that cannot be described in terms of uncorrelated interband excitations.Comment: 5 pages, 5 figures, to appear in Phys. Rev. B Rapid Communication

Effect of selective gastric residual monitoring on enteral intake in preterm infants

Objective: Prefeed gastric residuals (GRs) monitoring has been correlated with an increased time to reach full feeds and longer parenteral nutrition without beneficial effect on necrotizing enterocolitis (NEC) occurrence. We aimed to assess effects of a new local protocol to provide for the selective evaluation of GRs excluding their routine monitoring. Methods: We carried out a retrospective study based on a “before and after” design in a cohort of infants born at 23+0–31+6 weeks of gestation. The primary outcome was the age at full enteral feeding (150 mL/kg/d). Secondary outcomes included age at regaining of birth weight, and evaluation of Z-scores of weight, length, and head circumference at discharge. Results: We studied 49 infants in the selective GR group and 59 in the routine GR group. Age at full (150 mL/kg) enteral feeding (17.8 ± 10.1 vs. 22.9 ± 10.5 days, P = 0.017) and regaining of birth weight (11.1 ± 3.0 vs. 12.5 ± 3.5 days, P = 0.039) were lower while the Z-scores of weight at discharge (-1.10 ± 0.83 vs. -1.60 ± 1.45, P = 0.040) were higher in infants in the selective GR group in comparison with infants in the routine GR group. Conclusions: Selective monitoring of GRs decreased age at full enteral feeding and at regaining of birth weight and induced better Z-scores of weight at discharge in comparison with routine GR monitoring in a cohort of extremely preterm infants without increasing the incidence of NEC. Omitting prefeed GRs monitoring in clinical practice seems reasonable