פרסומים

Engineering entanglement between quantum systems often involves coupling through a bosonic mediator, which should be disentangled from the systems at the operation’s end. The quality of such an operation is generally limited by environmental and control noise. One of the prime techniques for suppressing noise is by dynamical decoupling, where one actively applies pulses at a rate that is faster than the typical time scale of the noise. However, for boson-mediated gates, current dynamical decoupling schemes require executing the pulses only when the boson and the quantum systems are disentangled. This restriction implies an increase of the gate time by a factor of √N, with N being the number of pulses applied. Here we propose and realize a method that enables dynamical decoupling in a boson-mediated system where the pulses can be applied while spin-boson entanglement persists, resulting in an increase in time that is at most a factor of π/2, independently of the number of pulses applied. We experimentally demonstrate the robustness of our entangling gate with fast dynamical decoupling to σz noise using ions in a Paul trap.

In humans, the monocyte pool comprises three subsets (classical, intermediate, and nonclassical) that circulate in dynamic equilibrium. The kinetics underlying their generation, differentiation, and disappearance are critical to understanding both steady-state homeostasis and inflammatory responses. Here, using human in vivo deuterium labeling, we demonstrate that classical monocytes emerge first from marrow, after a postmitotic interval of 1.6 d, and circulate for a day. Subsequent labeling of intermediate and nonclassical monocytes is consistent with a model of sequential transition. Intermediate and nonclassical monocytes have longer circulating lifespans ( approximately 4 and approximately 7 d, respectively). In a human experimental endotoxemia model, a transient but profound monocytopenia was observed; restoration of circulating monocytes was achieved by the early release of classical monocytes from bone marrow. The sequence of repopulation recapitulated the order of maturation in healthy homeostasis. This developmental relationship between monocyte subsets was verified by fate mapping grafted human classical monocytes into humanized mice, which were able to differentiate sequentially into intermediate and nonclassical cells.

Siderophores provide an established platform for studying molecular recognition principles in biological systems. Herein, the preparation of ferrichrome (FC) biomimetic analogues varying in length and polarity of the amino acid chain separating between the tripodal scaffold and the pendent Fe chelating hydroxamic acid groups was reported. Spectroscopic and potentiometric titrations determined their iron affinity to be within the range of efficient chelators. Microbial growth promotion and iron uptake studies were conducted on E. coli, P. putida and U. maydis. A wide range of siderophore activity was observed in the current series: from a rare case of a species-specific growth promotor in P. putida to an analogue matching FC in cross-phylum activity and uptake pathway. A fluorescent conjugate of the broad-range analogue visualized siderophore destination in bacteria (periplasmic space) vs. fungi (cytosol) mapping new therapeutic targets. Quantum dots (QDs) decorated with the most potent FC analogue provided a tool for immobilization of FC-recognizing bacteria. Bacterial clusters formed around QDs may provide a platform for their selection and concentration.

Thrombospondin-1 (THBS1) affects corpus luteum (CL) regression. Highly induced during luteolysis, it acts as a natural anti-angiogenic, proapoptotic compound. THBS1 expression is regulated in bovine luteal endothelial cells (LECs) by fibroblast growth factor-2 (FGF2) and transforming growth factor-beta1 (TGFB1) acting in an opposite manner. Here we sought to identify specific microRNAs (miRNAs) targeting THBS1 and investigate their possible involvement in FGF2 and TGFB1-mediated THBS1 expression. Several miRNAs predicted to target THBS1 mRNA (miR-1, miR-18a, miR-144, miR-194, and miR-221) were experimentally tested. Of these, miR-221 was shown to efficiently target THBS1 expression and function in LECs. We found that this miRNA is highly expressed in luteal cells and in mid-cycle CL. Consistent with the inhibition of THBS1 function, miR-221 also reduced Serpin Family E Member 1 [SERPINE1] in LECs and promoted angiogenic characteristics of LECs. Plasminogen activator inhibitor-1 (PAI-1), the gene product of SERPINE1, inhibited cell adhesion, suggesting that PAI-1, like THBS1, has anti-angiogenic properties. Importantly, FGF2, which negatively regulates THBS1, elevates miR-221. Conversely, TGFB1 that stimulates THBS1, significantly reduces miR-221. Furthermore, FGF2 enhances the suppression of THBS1 caused by miR-221 mimic, and prevents the increase in THBS1 induced by miR-221 inhibitor. In contrast, TGFB1 reverses the inhibitory effect of miR-221 mimic on THBS1, and enhances the upregulation of THBS1 induced by miR-221 inhibitor. These data support the contention that FGF2 and TGFB1 modulate THBS1 via miR-221. These in vitro data propose that dynamic regulation of miR-221 throughout the cycle, affecting THBS1 and SERPINE1, can modulate vascular function in the CL.

BACKGROUND: National data on iodine status in Israel are lacking. Reliance on iodine-depleted desalinated water, the absence of a salt iodization program, and reports of increased use of thyroid medication in Israel suggest that the population's iodine intake is likely inadequate. The aims of this study were therefore to determine the iodine status of Israeli school-age children (SAC) and pregnant women (PW) in a nationally representative sample obtained by a novel approach of using pre-discard urinalysis samples collected from a centralized national laboratory. METHODS: Spot urine samples from 1023 SAC and 1074 PW, representing all regions and major sectors in Israel, were collected during 2016 at the Maccabi Healthcare Services central laboratory. Urinary iodine concentration (UIC) was measured, and the results were analyzed by trimester, sex, region, and sector. RESULTS: SAC were iodine deficient, with a median (interquartile range [IQR]) UIC of 83 μg/L (52-127 μg/L); 62% of SAC UICs were below the World Health Organization adequacy range for SAC (100-199 μg/L). PW were also iodine deficient, with a median (IQR) UIC of 61 μg/L (36-97 μg/L); 85% of PW UICs were below the adequacy range for PW (150-249 μg/L). For both SAC and PW, the median UIC was below the World Health Organization's adequacy range across all sectors, sexes, and districts. Among SAC, the median (IQR) UIC was lower among females (75 μg/L; 48-119 μg/L) than males (92 μg/L; 59-133 μg/L; p < 0.05). Median UIC values of PW correlated significantly with the median UIC for SAC by sub-district (R = 0.3, p < 0.05). CONCLUSIONS: Urine sampling via a centralized national laboratory was efficient and cost-saving. Iodine deficiency in Israeli SAC and PW is a serious public-health concern. A national program of salt iodization and iodine supplementation of PW should be urgently considered.

 With its penchant for dissecting rehearsed attitudes and subverting expectations, Flann O’Brien’s writing displays an uncanny knack for comic doubling and self-contradiction. Focusing on the satirical energies and anti-authoritarian temperament invested in his style, Flann O’Brien: Problems with Authority interrogates the author’s clowning with linguistic, literary, legal, bureaucratic, political, economic, academic, religious and scientific powers in the sites of the popular, the modern and the traditional.Each chapter reflects on some aspect of his iconoclastic impulses; on the impertinent send-ups of pretension and orthodoxy to be found in his fiction, columns, and writing for stage and screen; on the very nature of his comedic inspiration.... Among the topics addressed are O’Brien’s satirical use of the pseudonym, the cliché and the Irish language; his irreverent repackaging of inherited myths, sacred texts and formative canons; and his refusal of literary and ideological closure.The emerging picture is of a complex literary project that is always, in some way, a writing against the weight of received wisdoms and inherited sureties. Preview 

The hydroclimatology, hydrometeorology, and hydrology of flash floods in the arid/semiarid southwestern United States are examined through empirical analyses of long-term, high-resolution rainfall and stream gauging observations, together with hydrological modeling analyses of the 19 August 2014 storm based on the Kinematic Runoff and Erosion Model (KINEROS2). The analyses presented here are centered on identifying the structure and evolution of flood-producing storms, as well as the interactions of space–time rainfall variability and basin characteristics in determining the upper-tail properties of rainfall and flood magnitudes over this region. This study focuses on four watersheds in Maricopa County, Arizona, with contrasting geomorphological properties. Flash floods over central Arizona are concentrated in both time and space, reflecting controls of the North American monsoon and complex terrain. Thunderstorm systems during the North American monsoon, as represented by the 19 August 2014 storm, are the dominant flood agents that determine the upper tail of flood frequency over central Arizona and that also shape the envelope curve of floods for watersheds smaller than 250 km2. Flood response for the 19 August 2014 storm is associated with storm elements of comparable spatial extent to the drainage area and slow movement for the three compact, headwater watersheds. Flood response for the elongated and relatively flat Skunk Creek highlights the importance of the spatial distribution of rainfall for transmission losses in arid/semiarid watersheds.

In recent years, we are observing substantial efforts towards the miniaturization of atomic cells to a millimeter scale and below, with the ultimate goal of enabling efficient and compact light vapor interactions. However, such miniaturization results in a reduction in optical path, effectively reducing the contrast of the optical signal. In order to overcome this obstacle, we have introduced and demonstrated a new approach of fluorescence double resonance optical pumping (FDROP) in the ladder-type atomic system. We have developed a theoretical model to predict the FDROP spectrum and validated this model using experimental results in a millimeter-size cell. We show that the contrast of fluorescence signal of the FDROP approach is higher than the transmission signal in the double resonance optical pumping approach. Taking advantage of this desired property, we have used the FDROP for the purpose of stabilizing the frequency of a laser operating at the telecom waveband with the hyperfine structure of the 5P3/2–4D5/2 transition in a millimeter-size cell. By beating the stabilized laser to another stabilized laser, we obtained frequency instability floor of 9×10−10 at around 1000 s in terms of Allan deviation. Such sources which are stabilized to miniaturized cells may play an important building block in diverse fields ranging e.g. from communication to metrology.

Background and Aims Deposition of silica in plant cell walls improves their mechanical properties and helps plants to withstand various stress conditions. Its mechanism is still not understood and silica–cell wall interactions are elusive. The objective of this study was to investigate the effect of silica deposition on the development and structure of sorghum root endodermis and to identify the cell wall components involved in silicification.MethodsSorghum bicolor seedlings were grown hydroponically with (Si+) or without (Si−) silicon supplementation. Primary roots were used to investigate the transcription of silicon transporters by quantitative RT–PCR. Silica aggregation was induced also under in vitro conditions in detached root segments. The development and architecture of endodermal cell walls were analysed by histochemistry, microscopy and Raman spectroscopy. Water retention capability was compared between silicified and non-silicified roots. Raman spectroscopy analyses of isolated silica aggregates were also carried out.Key Results Active uptake of silicic acid is provided at the root apex, where silicon transporters Lsi1 and Lsi2 are expressed. The locations of silica aggregation are established during the development of tertiary endodermal cell walls, even in the absence of silicon. Silica aggregation takes place in non-lignified spots in the endodermal cell walls, which progressively accumulate silicic acid, and its condensation initiates at arabinoxylan–ferulic acid complexes. Silicification does not support root water retention capability; however, it decreases root growth inhibition imposed by desiccation.Conclusion A model is proposed in which the formation of silica aggregates in sorghum roots is predetermined by a modified cell wall architecture and takes place as governed by endodermal development. The interaction with silica is provided by arabinoxylan–ferulic acid complexes and interferes with further deposition of lignin. Due to contrasting hydrophobicity, silicification and lignification do not represent functionally equivalent modifications of plant cell walls.