We report on the observation and coherent excitation of atoms on the narrow inner-shell orbital transition, connecting the erbium ground state \(\mathrm{Xe} 4f^{12} (^3\text{H}_6)6s^{2}\) to the ...excited state \(\mathrm{Xe} 4f^{11}(^4\text{I}_{15/2})^05d (^5\text{D}_{3/2}) 6s^{2} (15/2,3/2)^0_7\). This transition corresponds to a wavelength of 1299 nm and is optically closed. We perform high-resolution spectroscopy to extract the \(g_J\)-factor of the \(1299\)-nm state and to determine the frequency shift for four bosonic isotopes. We further demonstrate coherent control of the atomic state and extract a lifetime of 178(19) ms which corresponds to a linewidth of 0.9(1) Hz. The experimental findings are in good agreement with our semi-empirical model. In addition, we present theoretical calculations of the atomic polarizability, revealing several different magic-wavelength conditions. Finally, we make use of the vectorial polarizability and confirm a possible magic wavelength at 532 nm.
Social Networks have been developed dramatically just in decades. People now have a convenient way to interact with both social media and other people by making the most of using these social ...networks. Nevertheless, there is still lack of useful tools that can help users (both consumers and providers) managing such social media under events perspective. In order to meet one of these emerging requirements, a user-centric parallel split-n-merge framework applied for un-supervised clustering social media events is introduced. The purpose of this framework is to cluster social media to events they depict by exploiting and exploring the role of users (who) and the way users interact with data (where, what, when) and others (what, who). The output of the proposed framework can be used for event organization/summarization, and as pre-processing stage for event detection and tracking. Major advantages of the proposed framework are (1) low computational solution w.r.t large-scale data, (2) parallel running, and (3) unsupervised clustering with no training data and third-party information requirements. The comparison between the proposed framework and up-to-date methods with MediaEval2013 1 test-bed and evaluation tools shows a very competitive result.
The present study compares, from a morphological point of view, the possible differences between perfusion- and immersion-fixation techniques performed on rat myocardium in order to evaluate their ...reliability. The data we obtained showed that when the two techniques are carried out with particular care, they do not present significant differences in tissue preservation. Furthermore, we also evaluated the ultrastructural of rat myocardium at the end of in vitro experiments. In this case, signs of subcellular changes, such as vacuolar degeneration, swollen mitochondria, intermyofibrillar myelin-like figures and enlargements of non specialized junctions of the intercalated discs can frequently occur. So, our results indicate that the morphological integrity of myocardium is not completely preserved during in vitro investigations.
Male rats were exposed to noise for 6 running hours and the effects of pretreatment with the benzodiazepine diazepam on the adrenal gland were evaluated. Ultrastructural examination showed that, ...after noise exposure, zona reticularis cells resulted the more affected, exhibiting areas of diluted cytoplasm, disarranged endoplasmic reticulum, membrane vestigia and some altered mitochondria; diluted cytoplasmic areas appeared in noradrenaline-storing cells, too. On the contrary, zona reticularis cells from diazepam-pretreated and noise-exposed rats resulted significantly less altered, as well as the noradrenaline-storing cells. The present findings indicate that diazepam is able to exert some protective action on adrenal gland alterations due to noise exposure.
Protein ingestion increases renal blood flow and glomerular filtration rate (GFR). This study investigated in healthy adults if the renal response to protein ingestion includes changes in urinary ...sodium (Na) excretion rate and Na balance. Renal clearance of Na and inulin (used as index of GFR) were measured in 25 healthy adults before (90 min) and after (180 min) a standard meal and, as control, before and after administration of water and Na-chloride (saline). The meal consisted of red lean meat (2 g protein/kg body weight); in control experiments, water and Na were given to match water and Na content of the meal. ANOVA for repeated measures, Student's t-test, and linear regression were used for statistical analysis. GFR and urinary Na excretion increased over baseline after the meal (p < 0.001), not after saline. The post-meal natriuretic response was accounted for an early (0-90 min) increase in glomerular filtered load of Na (p < 0.001) and a late (90-180 min) reduction in tubular Na reabsorption (p < 0.02). Urine flow rate and plasma Na did not significantly change after the meal and in control experiments. Analysis of Na balance showed that post-meal Na excretion was significantly higher than baseline also after Na balance returned to pre-meal values. In healthy individuals, a meat meal stimulates natriuresis and causes a net decrease in Na balance. The renal natriuretic response to the meal appears secondary to the meal-induced changes in renal hemodynamics. The data are in keeping with the hypothesis that dietary protein intake affects also renal Na handling.
The paper presents an adaptive scheme for image-data compression. It is a region-based approach that suitably integrates two different approaches to image coding, vector quantization (VQ) and ...polynomial approximation (PA). The scheme is adaptive from the point of view of the human observer: the perceptually most significant areas are those near edges or details. In smoothed areas, PA can be used with notable results, but there VQ must be employed to ensure high fidelity. The two techniques exhibit a complementarity in both advantages and drawbacks. PA is not efficient in compressing high-frequency areas, but yields the best results when applied to highly correlated data. VQ is unable to reach high-compression ratios because of its low adaptability, but is quite suitable for compressing uncorrelated data. The means to achieve the integration of the two techniques is a control image containing information about edge and texture locations. In the paper, edge encoding and restoration are also addressed, which are closely related to the proposed hybrid scheme; block prediction is also utilized to further reduce the residual redundancy between VQ blocks. The exploitation of the best features of both approaches results in high compression factors, and in perceivable good quality. In particular, bit rates range from 0.15 to 0.07 bpp. Main applications of this compression scheme are in the areas of very-low bit rate image transmission and image archiving.< >
The effects of esaprazole, a novel antiulcer drug, on gastric acid secretion and plasma gastrin levels were investigated in dogs provided with a gastric fistula or Heidenhain pouch. Esaprazole ...affected in a different extent the tests performed on dogs with a gastric fistula. The greatest inhibitory effect was obtained against 2-deoxy-D-glucose-induced acid output and gastrin release. An intermediate inhibition by esaprazole was detected on bethanechol-evoked secretion, and the lowest activity was found versus histamine-stimulated secretion. All these responses were strongly inhibited by the antimuscarinic drug pirenzepine used as reference drug. Moreover, both esaprazole and pirenzepine prevented the acid secretory response to a test meal in dogs with a Heidenhain pouch, without significantly affecting plasma gastrin levels. The present results suggest that the depressant action of esaprazole on gastric secretion depends on its peripheral anticholinergic activity, consisting of a partial blockade of acid output and a main reduction of vagally mediated gastrin release. On the basis of these findings, the antiulcer activity of esaprazole might be in part ascribed to its inhibitory effects on gastric secretion.
This paper presents a novel predictive coding scheme for image-data compression by vector quantization (VQ). On the basis of a prediction, further compression is achieved by using a dynamic ...codebook-reordering strategy that allows a more efficient Huffman encoding of vector addresses. The proposed method is lossless, for it increases the compression performances of a baseline vector quantization scheme, without causing any further image degradation. Results are presented and a comparison with Cache-VQ is made.
