Regimes of atomic diffraction: Raman versus Bragg diffraction in retroreflective geometries

We provide a comprehensive study of atomic Raman and Bragg diffraction when coupling to a pair of counterpropagating light gratings (double diffraction) or to a single one (single diffraction) and discuss the transition from one case to the other in a retroreflective geometry as the Doppler detuning changes. In contrast to single diffraction, double Raman loses its advantage of high diffraction efficiency for short pulses and has to be performed in a Bragg-type regime. Moreover, the structure of double diffraction leads to further limitations for broad momentum distributions on the efficiency of mirror pulses, making the use of (ultra) cold ensembles essential for high diffraction efficiency.Comment: 16 pages, 14 figure

Atomic Raman scattering: Third-order diffraction in a double geometry

In a retroreflective scheme atomic Raman diffraction adopts some of the properties of Bragg diffraction due to additional couplings to off-resonant momenta. As a consequence, double Raman diffraction has to be performed in a Bragg-type regime. Taking advantage of this regime, double Raman allows for resonant higher-order diffraction. We study theoretically the case of third-order diffraction and compare it to first order as well as a sequence of first-order pulses giving rise to the same momentum transfer as the third-order pulse. In fact, third-order diffraction constitutes a competitive tool for the diffraction of ultracold atoms and interferometry based on large momentum transfer since it allows to reduce the complexity of the experiment as well as the total duration of the diffraction process compared to a sequence.Comment: 10 pages, 13 figure

Influence of intravenous 10% amino acids infusion on serum albumin concentration in hypoalbuminemic dogs

ObjectiveTo evaluate the effect of parenteral amino acid application in hospitalized hypoalbuminemic dogs.Materials and methodsMedical records of client-owned hypoalbuminemic dogs (albumin ≤ 25 g/L) were analyzed. Dogs receiving amino acids for only 1–2 days, receiving transfusions or surgery, or <6 months of age were excluded. Dogs were grouped as those receiving intravenous amino acids (AA, 80 dogs) over 3 days and longer, and those without additional amino acid treatment (CON, 78 dogs). Duration of hospitalization, albumin, and total protein concentrations were compared between groups by Mann–Whitney U test. Course of albumin and total protein concentration was evaluated by Friedman test and Dunn’s multiple comparison test. Significance was set to p ≤ 0.05.ResultsDogs in group AA received 10% amino acid solution intravenously over median 4 days (3–11 days). No significant differences regarding survival and adverse effects were observed between groups. Dogs of group AA had significantly longer duration of hospitalization (median 8 days; 3–33 days) compared to group CON dogs (median 6 days, 3–24 days; p < 0.001). Initial albumin concentration was lower in group AA compared to CON (p < 0.001). This difference was no longer present on day 2 (p = 0.134).Conclusions and clinical relevanceIntravenous application of 10% amino acid solution in hypoalbuminemic dogs can improve albumin concentration after 2 days, but does not influence outcome

Bragg-diffraction-induced imperfections of the signal in retroreflective atom interferometers

We present a detailed study of the effects of imperfect atom-optical manipulation in Bragg-based light-pulse atom interferometers. Off-resonant higher-order diffraction leads to population loss, spurious interferometer paths, and diffraction phases. In a path-dependent formalism, we study numerically various effects and analyze the interference signal caused by an external phase or gravity. We compare first-order single and double Bragg diffraction in retroreflective setups. In double Bragg diffraction, phase imperfections lead to a beating due to three-path interference. Some effects of diffraction phases can be avoided by adding the population of the outer exit ports of double diffraction

Atomic Raman scattering: Third-order diffraction in a double geometry

In a retroreflective scheme with an atom initially at rest, atomic Raman diffraction adopts some of the properties of Bragg diffraction due to additional couplings to off-resonant momenta. As a consequence, double Raman diffraction has to be performed in a Bragg-type regime, where the pulse duration is sufficiently long to suppress diffraction into spurious orders. Taking advantage of this regime, double Raman allows for resonant higher-order diffraction. We study theoretically the case of third-order diffraction and compare it to first order as well as a sequence of first-order Raman pulses giving rise to the same momentum transfer as the third-order pulse. Moreover, we demonstrate that interferometry is possible, and we investigate amplitude and contrast of a third-order double Raman Mach-Zehnder interferometer. In fact, third-order diffraction constitutes a competitive tool for the diffraction of ultracold atoms and interferometry based on large momentum transfer since it allows one to reduce the complexity of the experiment as well as the total duration of the diffraction process compared to a sequence, at the cost of higher pulse intensities

Digitalization and its Impact on the Future Role of SCM Executives in Talent Management – An International Cross-Industry Delphi Study

In the field of supply chain management (SCM), attracting and developing appropriate talent is critical for achieving most SCM goals, as extensive skills are necessary to do the job properly. In order to ensure that future-proof talent can continue to emerge in this discipline, the role of SCM executives is extremely important. Although many studies have been conducted in the field of talent management (TM), the future role of SCM executives has been mostly neglected in research. The present empirical study addresses this gap, taking into consideration the fourth industrial revolution, as innovation in technology continues to drive significant changes in the SCM field. Aiming to investigate the extent to which increasing digitalization is influencing the future role of SCM executives, a Delphi study with 103 experts from industry, academics, and politics/associations was carried out. In order to identify meaningful topic clusters from the data, fuzzy c-means clustering was used. From an actor-network theory perspective, our results show that in some areas of TM, digitalization is leading to a strong fusion of SCM executives and digital technologies, as well as to a clear division of roles, in which either SCM leaders or technology will dominate in the future

Prevention of colitis-associated cancer by selective targeting of immunoproteasome subunit LMP7

Chronic inflammation is a well-known risk factor in development of intestinal tumorigenesis, although the exact mechanisms underlying development of colitis-associated cancer (CAC) still remain obscure. The activity and function of immunoproteasome has been extensively analyzed in the context of inflammation and infectious diseases. Here, we show that the proteasomal immunosubunit LMP7 plays an essential role in development of CAC. Mice devoid of LMP7 were resistant to chronic inflammation and formation of neoplasia, and developed virtually no tumors after AOM/DSS treatment. Our data reveal that LMP7 deficiency resulted in reduced expression of pro-tumorigenic chemokines CXCL1, CXCL2 and CXCL3 as well as adhesion molecule VCAM-1. As a consequence, an impaired recruitment and activity of tumor-infiltrating leukocytes resulting in decreased secretion of cytokines IL-6 and TNF-α was observed. Further, the deletion or pharmacological inhibition of LMP7 and consequent blockade of NF-κB abrogated the production of IL-17A, which possesses a strong carcinogenic activity in the gut. Moreover, in vivo administration of the selective LMP7 inhibitor ONX-0914 led to a marked reduction of tumor numbers in wild-type (WT) mice. Collectively, we identified the immunoproteasome as a crucial mediator of inflammation-driven neoplasia highlighting a novel potential therapeutic approach to limit colonic tumorigenesis