Delegation Proxies: The Power of Propagation

Scoping behavioral variations to dynamic extents is useful to support non-functional requirements that otherwise result in cross-cutting code. Unfortunately, such variations are difficult to achieve with traditional reflection or aspects. We show that with a modification of dynamic proxies, called delegation proxies, it becomes possible to reflectively implement variations that propagate to all objects accessed in the dynamic extent of a message send. We demonstrate our approach with examples of variations scoped to dynamic extents that help simplify code related to safety, reliability, and monitoring.

The integrity of the G2421-C2395 base pair in the ribosomal E-site is crucial for protein synthesis.

During the elongation cycle of protein biosynthesis, tRNAs traverse through the ribosome by consecutive binding to the 3 ribosomal binding sites (A-, P-, and E- sites). While the ribosomal A- and P-sites have been functionally well characterized in the past, the contribution of the E-site to protein biosynthesis is still poorly understood in molecular terms. Previous studies suggested an important functional interaction of the terminal residue A76 of E-tRNA with the nucleobase of the universally conserved 23S rRNA residue C2394. Using an atomic mutagenesis approach to introduce non-natural nucleoside analogs into the 23S rRNA, we could show that removal of the nucleobase or the ribose 2'-OH at C2394 had no effect on protein synthesis. On the other hand, our data disclose the importance of the highly conserved E-site base pair G2421-C2395 for effective translation. Ribosomes with a disrupted G2421-C2395 base pair are defective in tRNA binding to the E-site. This results in an impaired translation of genuine mRNAs, while homo-polymeric templates are not affected. Cumulatively our data emphasize the importance of E-site tRNA occupancy and in particular the intactness of the 23S rRNA base pair G2421-C2395 for productive protein biosynthesis.

Zwischen Strafvollzug und Fürsorge. Die sanktgallische Schutzaufsicht im 19. Jahrhundert

Im Artikel wird die Geschichte des sanktgallischen Schutzaufsichtsvereins für entlassene Sträflinge zwischen 1839 und 1903 aufgearbeitet, wobei der Fokus auf dessen mehrfach ambivalenten Situation als privater Verein mit gesetzlichem Auftrag liegt. Der Schutzaufsichtsverein bewegte sich in seiner Tätigkeit stets zwischen Strafvollzug und Fürsorge und damit zwischen Schutz und Überwachung der Entlassenen. Als privater Verein war er zudem gezwungen, seine Stellung gegenüber den Behörden und innerhalb des sich ausdifferenzierenden Strafvollzugssystems immer wieder neu auszuhandeln. Diese bemerkenswerte Situation der Schutzaufsicht wird durch die Analyse der Zusammenarbeit zwischen privater und staatlicher Seite, der Ziele des Schutzaufsichtsvereins sowie der Mittel zu deren Durchsetzung deutlich gemacht. Dabei zeigt sich, dass die Schutzaufsicht bis zu einem gewissen Grad als Fortsetzung des staatlichen Strafvollzugs intendiert war, dabei aber an institutionellen Begebenheiten scheiterte.

Worldwide evidence of a unimodal relationship between productivity and plant species richness

The search for predictions of species diversity across environmental gradients has challenged ecologists for decades. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses, and at high productivity a few highly competitive species dominate. Over time the HBM has become increasingly controversial, and recent studies claim to have refuted it. Here, by using data from coordinated surveys conducted throughout grasslands worldwide and comprising a wide range of site productivities, we provide evidence in support of the HBM pattern at both global and regional extents. The relationships described here provide a foundation for further research into the local, landscape, and historical factors that maintain biodiversity.

Critical point and scale setting in SU(3) plasma: An update

We explore a method developed in statistical physics which has been argued to have exponentially small finite-volume effects, in order to determine the critical temperature Tc of pure SU(3) gauge theory close to the continuum limit. The method allows us to estimate the critical coupling βc of the Wilson action for temporal extents up to Nτ∼20 with ≲0.1% uncertainties. Making use of the scale setting parameters r0 and t0−−√ in the same range of β-values, these results lead to the independent continuum extrapolations Tcr0=0.7457(45) and Tct0−−√=0.2489(14), with the latter originating from a more convincing fit. Inserting a conversion of r0 from literature (unfortunately with much larger errors) yields Tc/ΛMS¯¯¯¯¯=1.24(10).

Longitudinal extension of myelomalacia by intramedullary and subdural hemorrhage in a canine model of spinal cord injury

BACKGROUND CONTEXT In canine intervertebral disc (IVD) extrusion, a spontaneous animal model of spinal cord injury, hemorrhage is a consistent finding. In rodent models, hemorrhage might be involved in secondary tissue destruction by biochemical mechanisms. PURPOSE This study aimed to investigate a causal association between the extents of intramedullary, subdural and epidural hemorrhage and the severity of spinal cord damage following IVD extrusion in dogs. STUDY DESIGN/SETTING A retrospective study using histologic spinal cord sections from 83 dogs euthanized following IVD extrusion was carried out. METHODS The degree of hemorrhage (intramedullary, subdural, epidural), the degree of spinal cord damage in the epicenter (white and gray matter), and the longitudinal extent of myelomalacia were graded. Associations between the extent of hemorrhage and the degree of spinal cord damage were evaluated statistically. RESULTS Intramedullary and subdural hemorrhages were significantly associated with the degree of white (p<.001/ p=.004) and gray (both p<.001) matter damage, and with the longitudinal extension of myelomalacia (p<.001/p=.005). Intriguingly, accumulation of hemorrhagic cord debris inside or dorsal to a distended and ruptured central canal in segments distant to the epicenter of the lesion was observed exhibiting a wave-like pattern on longitudinal assessment. The occurrence of this debris accumulation was associated with high degrees of tissue destruction (all p<.001). CONCLUSIONS Tissue liquefaction and increased intramedullary pressure associated with hemorrhage are involved in the progression of spinal cord destruction in a canine model of spinal cord injury and ascending or descending myelomalacia. Functional and dynamic studies are needed to investigate this concept further.

Selbstbereicherung an kollektiven Ressourcen. «Eigennutz» als Leitmotiv politischer und sozialer Skandalisierung in der vormodernen Eidgenossenschaft

Angemessen historisiert kann der «Skandal» auch für die Vormoderne als produktive Forschungskategorie genutzt werden, um nach fundamentalen Wertehaltungen und zugehörigen Konfliktmodi zu fragen. Während Skandale in heutiger Zeit über massenmedial verbreitete Enthüllungen befeuert werden, adressierte Skandalisierung in der Vormoderne unterschiedliche Kommunikationsräume wie etwa Familie, Peer Groups, politische Gremien und Versammlungen, die als ständisch gerahmte, ineinander verschachtelte und miteinander interagierende Teilöffentlichkeiten fungierten. Eigentliches Skandalon stellte der Vorwurf des Eigennutzes bzw. die Schädigung des gemeinen Nutzens dar. Angeprangert wurden Selbstbereicherung, undurchsichtige Machenschaften oder übermässige Profite aus Amtstätigkeiten. Skandalen kam dabei die Funktion von Läuterungsritualen zu, welche lokalen Gesellschaften und ständischen Gruppen die ungeschriebenen Gesetze ihres Zusammenlebens in Erinnerung riefen.