Abspaltung ortho-ständiger Substituenten aus ionisierten Phenyl-2-propanonen nach Elektronenstoßaktivierung

Die Molekülionen der Phenyl-2-propanone 2a-4a verlieren positionsspezifisch o-ständige Cl -, Br - bzw. I -Atome unter Bildung von (M-Hal')+- Ionen (m/z 133) hoher Intensität (70/12 eV; 1. und 2. FFR) und identischer Struktur (MIKE-CAD-Spektren). Die Fragmentionen bei m/z 133 aus o- Chlorphenyl-2-propanon (2a) und 2,2-Dimethyl-2,3-dihydro[fc]furan (11) sind von ähnlicher, aber nicht identischer Struktur. Die stoßaktivierten (2. FFR) (M-Br*)+-Ionen aus o-Bromphenyl-2-propanon (3a) und 1-Brom-lphenyl- 2-propanon (12) liefern praktisch deckungsgleiche Spektren. Die Hauptreaktion der (M-Hal')+-Ionen aus 2a-4a ist die Abspaltung von CO, das ausschließlich das C-Atom der Carbonylgruppe enthält (13C-Markierung). Der mechanistische Verlauf der Reaktionsfolge wird diskutiert (Abb. 5 und 8). In the gas phase, the phenyl-2-propanone molecules 2a-4a lose upon electron impact chloro-, bromo-, and iodo-radicals specifically at the orthoposition of the phenyl group giving rise to strong (M-Hal')+-ions (70/12 eV; 1st and 2nd FFR) of identical structure as confirmed by their MIKECAD- spectra. The daughter ions at m/z 133 from o-chlorophenyl-2-propanone (2a) and 2,2-dimethyl-2,3-dihydro[b]furane (11) are structurally similar but not identical (similarity index 99.8). The collisionally activated (2nd FFR) (M-Br')+-ions from o-bromophenyl-2-propanone (3a) and 1- bromo-1-phenyl-2-propanone (12) produce virtually congruent spectra. The most important subsequent fragmentation of the (M-Hal')+-ions from 2a-4a is the loss of CO which incorporates the C-atom of the carbonyl group exclusively (13C labelling). Mechanistic aspects of the fragmentation sequences are discussed (Figs. 5 and 8)

Lender forbearance

We use a threshold-based design to study ex post discretion in lenders’ contractual enforcement of covenant violations. At preset thresholds, lenders enforce contractual breaches only infrequently, but this enforcement is associated with material consequences, e.g., fees and renegotiations. Enforcement varies significantly over time and peaks when credit conditions are tightest, indicating that enforcement is procyclical. Costly coordination reduces enforcement: syndicates with ex ante restrictive voting requirements enforce at lower rates. Consistent with theories of lender competition and implicit contracting, enforcement rates are lower for borrowers with access to alternative sources of financing and well-reputed lead arrangers

X-Ray and Infrared Enhancement of Anomalous X-ray Pulsar 1E 2259+58

The long term (~1.5 years) X-ray enhancement and the accompanying infrared enhancement light curves of the anomalous X-ray pulsar 1E 2259+58 following the major bursting epoch can be accounted for by the relaxation of a fall back disk that has been pushed back by a gamma-ray flare. The required burst energy estimated from the results of our model fits is low enough for such a burst to have remained below the detection limits. We find that an irradiated disk model with a low irradiation efficiency is in good agreement with both X-ray and infrared data. Non-irradiated disk models also give a good fit to the X-ray light curve, but are not consistent with the infrared data for the first week of the enhancement.Comment: 17 pages, 3 figures, accepted for publication in Ap

Immobilization of catalase via adsorption into natural and modified active carbon obtained from walnut in various methods

In the present work, the immobilization of catalase into natural active carbon and active carbon modified by hydrochloric acid was carried out. In the experimental section, the effects of pH, ionic strength andreaction temperature were chosen as parameters, with experiments performed in batch system. For the optimization of immobilization procedure, values of kinetic parameters were evaluated. It was observedthat storage and operational stabilities of the enzyme increased with immobilization. The results obtained from experiments showed that active carbon is a valuable support for the adsorption of enzymes

Space--time fluctuations and the spreading of wavepackets

Using a density matrix description in space we study the evolution of wavepackets in a fluctuating space-time background. We assume that space-time fluctuations manifest as classical fluctuations of the metric. From the non-relativistic limit of a non-minimally coupled Klein-Gordon equation we derive a Schr\"odinger equation with an additive gaussian random potential. This is transformed into an effective master equation for the density matrix. The solutions of this master equation allow to study the dynamics of wavepackets in a fluctuating space-time, depending on the fluctuation scenario. We show how different scenarios alter the diffusion properties of wavepackets.Comment: 11 page

Earnings announcement return extrapolation

We propose that extrapolative beliefs about earnings announcement (EA) returns may contribute to our understanding of EA return patterns. We construct a theoretically-motivated measure of extrapolative investors’ expectations based on a stock’s recent history of EA returns. We then show that this measure explains cross-sectional variation in stock returns and investor behavior around EAs. Stocks expected to have high EA returns according to our measure experience predictable increases in prices before EAs and predictable decreases afterwards. These patterns are economically significant: investors that buy (sell) a portfolio that is long firms with high recent EA returns and short firms with low recent EA returns in the pre-EA (post-EA) period earn daily five-factor abnormal returns of 16.1 bps (18.3 bps). Using individual investor trades data and a measure of institutional trading, we find that individual and institutional investors are more likely to purchase stocks with high recent EA returns, consistent with at least a subset of investors forming extrapolative beliefs about EA returns

Incomplete Punishment Networks in Public Goods Games: Experimental Evidence

Abundant evidence suggests that high levels of contributions to public goods can be sustained through self-governed monitoring and sanctioning. This experimental study investigates the effectiveness of decentralized sanctioning institutions in alternative punishment networks. Our results show that the structure of punishment network significantly affects allocations to the public good. In addition, we observe that network configurations are more important than punishment capacities for the levels of public good provision, imposed sanctions and economic efficiency. Lastly, we show that targeted revenge is a major driver of anti-social punishment

Recent Progress on Anomalous X-ray Pulsars

I review recent observational progress on Anomalous X-ray Pulsars, with an emphasis on timing, variability, and spectra. Highlighted results include the recent timing and flux stabilization of the notoriously unstable AXP 1E 1048.1-5937, the remarkable glitches seen in two AXPs, the newly recognized variety of AXP variability types, including outbursts, bursts, flares, and pulse profile changes, as well as recent discoveries regarding AXP spectra, including their surprising hard X-ray and far-infrared emission, as well as the pulsed radio emission seen in one source. Much has been learned about these enigmatic objects over the past few years, with the pace of discoveries remaining steady. However additional work on both observational and theoretical fronts is needed before we have a comprehensive understanding of AXPs and their place in the zoo of manifestations of young neutron stars.Comment: 10 pages, 6 figures; to appear in proceedings of the conference "Isolated Neutron Stars: From the Interior to the Surface" eds. S. Zane, R. Turolla, D. Page; Astrophysics & Space Science in pres

Influence of the second stage of labor on maternal and neonatal outcomes in vaginal births after caesarean section: a multicenter study in Germany

Background: The American College of Obstetricians and Gynecologists (ACOG) introduced a new standard of care in 2014, extending the duration of the second stage of labor in order to reduce caesarean delivery (CD) rates and its severe complications. The aim of the present study is to evaluate success rates of trial of labor after caesarean section (TOLAC), as well as maternal and neonatal outcomes after the establishment of the recent guidelines. Methods: A retrospective study was performed at two large departments in Germany from January 2008 to January 2018. Patients undergoing TOLAC were divided into two groups. Group I (958 patients) was constituted before the establishment of the current guidelines, and Group II (588 patients) after the establishment of the guidelines. A subgroup analysis was performed to compare neonatal outcomes after successful TOLAC and operative vaginal delivery with those after failed TOLAC and secondary CD. Results: The success rate of vaginal births after cesarean section (VBAC) fell from 66.4 in Group I to 55.8 in Group II (p < 0.001). The median duration of the second stage of labor was statistically significantly longer in Group II than in Group I (79.3 ± 61.9 vs. 69.3 ± 58.2 min) for patients without previous vaginal birth. The incidence of operative vaginal delivery decreased from Group I to Group II (9.6 vs. 6.8). The incidence of third- and fourth-degree perineal lacerations, blood loss and emergency CD were similar in the two groups. Concerning the neonatal outcome, our groups did not differ significantly in regard of rates of umbilical artery cord pH < 7.1 (p = 0.108), the 5-min Apgar scores below 7 (p = 0.224) and intubation (p = 0.547). However, the transfer rates to the neonatal care unit were significantly higher in Group II than in Group I (p < 0.001). Neonatal outcomes did not differ significantly in the subgroup analysis. Conclusion: Extending the second stage of labor does not necessarily result in more vaginal births after TOLAC. Maternal and neonatal outcomes were similar in both groups. Further studies will be needed to evaluate the role of operative vaginal delivery and the duration of the second stage of labor in TOLAC. © 2021, The Author(s)

Citološka analiza endometrija kod krava s akutnim i kroničnim endometritisom.

The aim of the present study was to evaluate the findings of endometrial cytology in cows with acute and chronic endometritis. For this purpose samples were collected from 217 Brown Swiss and Holstein cows, housed on the Atatürk University Dairy Research Farm between the years 2010 and 2012, and they were stained with Giemsa for cytological examination. In the evaluation, overall 100 cells were counted in the microscopic area and the cells were classified as polymorph nuclear leukocyte, macrophage, lymphocyte and epithelial cells. The cytopathological classification was done according to the percentages of inflammatory cells. Briefly, 126 (58.06 %) samples had extensive inflammatory cells, and of the uterine samples 91 (41.94 %) had normal exfoliation. According to the cellular density results, acute, and chronic and subacute endometritis were described in 68 (31.33 %), 23 (10.60 %) and 35 (16.13 %) cases, respectively. In conclusion, endometrial cytology was found to be an applicable and reliable diagnostic method in diagnosis and diffentiation of acute and chronic endometritis.Cilj istraživanja bio je procijeniti citološke nalaze u endometriju krava s akutnim i kroničnim endometritisom. U tu su svrhu između 2010. i 2012. godine bili prikupljeni uzorci od 217 krava smeđe i holštajnske pasmine, uzgajanih na pokusnoj mliječnoj farmi na Sveučilištu Atatürk. Uzorci su bili obojeni Giemsinim bojenjem. Pri procjeni je u vidnom polju mikroskopa bilo izbrojeno ukupno 100 stanica kojesu razvrstane u polimorfononuklearne leukocite, makrofage, limfocite i epitelne stanice. Citopatološko razvrstavanje bilo je provedeno na osnovi postotka upalnih stanica. Ukratko, upalne stanice bile su ustanovljene u 126 (58,06 %) uzoraka, dok je u 91 (41,94 %) uzorku maternice ustanovljeno normalno ljuštenje stanica. Na osnovi stanične gustoće, akutni endometritis bio je dokazan u 68 (31,33 %) uzoraka, kronični u 23 (10,60 %), a subakutni u 35 (16,13 %) uzoraka. Zaključno, citologija endometrija pokazala se primjenjljivom i pouzdanom metodom u dijagnostici odnosno razlikovanju akutnog od kroničnog endometritisa