The Mansueto Library – Notes on a glazed steel grid shell from design to construction

The highlight of the Joe and Rika Mansueto Library in Chicago is an almostdematerialized glazed steel grid shell spanning over the reading room. Thegeometrically constructed translational shell is 36.5 m wide, 73 m long and featuresa mesh size of 2 by 2 m. The building, currently under construction, includesfurther special structures as a 20 m long, glazed steel bridge connecting the newlibrary with the existing building and a row of glass study rooms, which reach atotal transparency by exploiting the structural properties of glass. The presentarticle gives an overview of the design, calculation and construction phases of thegrid shell and the other special structure

Revisiting the Andean butterfly Eryphanis zolvizora group (Lepidoptera, Nymphalidae) : one or several species?

Eryphanis zolvizora (Hewitson, 1877) is a rare Andean endemic butterfly, described from Bolivia, which has been historically classified either as a unique species, or as part of a group of three allopatric species from Bolivia, Ecuador and Colombia. In this paper, the group is revised using more than 200 specimens housed in 35 European and North and South American public and private collections. For the first time, the presence of the group in Western Ecuador and Venezuela is confirmed, and important data on Peruvian populations are provided. In some populations, individual variations of genitalia are observed. Nevertheless, male genitalia allow the distinction of four geographical groups. Considering also habitus characters, eight taxa are distinguished and considered to be subspecies, of which five are new: Eryphanis zolvizora inca ssp. nov., Eryphanis zolvizora chachapoya ssp. nov., Eryphanis zolvizora casagrande ssp. nov., Eryphanis zolvizora reyi ssp. nov., and Eryphanis zolvizora isabelae ssp. nov. In the present state of knowledge, these taxa are allopatric, except for a possible geographic overlap in central Peru, where data are insufficient to prove sympatry. The “several subspecies vs. several species” dilemma is discussed, considering its impact for conservation action and policies

Cable-stayed glass façades - 15 years of innovation at the cutting edge

Today’s demand for highly transparent building envelopes calls for innovativesolutions. Cable-stayed glass façades make it possible to dematerialize the buildingenvelope so as to make it almost imperceptible. Werner Sobek has designed a greatnumber and variety of cable-stayed façades. The primary structural system carryingmost of these façades consists of straight tension members (e.g. tension rods,cables), typically in a parallel arrangement. The tension members transfer the deadload of the glazing very efficiently to the supports. Under wind load the membersundergo large deflections thus activating their lateral stiffness. As a result, thedetailing of these façades requires innovative design approaches and special care toallow for such large deflections. Besides this, each project has its individualchallenges such as a complex geometry, large openings, difficult edge conditions,warping of IG units, bomb blast requirements, etc. The present article gives anoverview of the development of cable-stayed façades as designed by Werner Sobekover the last 15 years. The overview includes completed projects as well as façadescurrently under construction or in the design phase

Who is at Risk of Parkinson Disease? Refining the Preclinical Phase of GBA1 and LRRK2 Variant Carriers: a Clinical, Biochemical, and Imaging Approach

Purpose of Review: Genetic variants in GBA1 and LRRK2 genes are the commonest genetic risk factor for Parkinson disease (PD); however, the preclinical profile of GBA1 and LRRK2 variant carriers who will develop PD is unclear. This review aims to highlight the more sensitive markers that can stratify PD risk in non-manifesting GBA1 and LRRK2 variant carriers. Recent Findings: Several case–control and a few longitudinal studies evaluated clinical, biochemical, and neuroimaging markers within cohorts of non-manifesting carriers of GBA1 and LRRK2 variants. Summary: Despite similar levels of penetrance of PD in GBA1 and LRRK2 variant carriers (10–30%), these individuals have distinct preclinical profiles. GBA1 variant carriers at higher risk of PD can present with prodromal symptoms suggestive of PD (hyposmia), display increased α-synuclein levels in peripheral blood mononuclear cells, and show dopamine transporter abnormalities. LRRK2 variant carriers at higher risk of PD might show subtle motor abnormalities, but no prodromal symptoms, higher exposure to some environmental factors (non-steroid anti-inflammatory drugs), and peripheral inflammatory profile. This information will help clinicians tailor appropriate screening tests and counseling and facilitate researchers in the development of predictive markers, disease-modifying treatments, and selection of healthy individuals who might benefit from preventive interventions

A2A Receptor Antagonism and Dyskinesia in Parkinson's Disease

Dyskinesia, a major complication of treatment of Parkinson's disease (PD), involves two phases: induction, which is responsible for dyskinesia onset, and expression, which underlies its clinical manifestation. The unique cellular and regional distribution of adenosine A2A receptors in basal ganglia areas that are richly innervated by dopamine, and their antagonistic role towards dopamine receptor stimulation, have positioned A2A receptor antagonists as an attractive nondopaminergic target to improve the motor deficits that characterize PD. In this paper, we describe the biochemical characteristics of A2A receptors and the effects of adenosine A2A antagonists in rodent and primate models of PD on L-DOPA-induced dyskinesia, together with relevant biomarker studies. We also review clinical trials of A2A antagonists as adjuncts to L-DOPA in PD patients with motor fluctuations. These studies have generally demonstrated that the addition of an A2A antagonist to a stable L-DOPA regimen reduces OFF time and mildly increases dyskinesia. However, limited clinical data suggest that the addition of an A2A antagonist along with a reduction of L-DOPA might maintain anti-Parkinsonian benefit and reduce dyskinesia. Whether A2A antagonists might reduce the development of dyskinesia has not yet been tested clinically

Actuation of concrete slabs under bending with integrated fluidic actuators

Previous studies have shown that 33 % to 44 % of the mass embodied in residential and office buildings and up to 50 % in high-rise buildings is attributable to floor slabs. Floor slabs are typically bearing a bending load. Load-transfer through bending is not efficient because the material in the proximity of the neutral plane is practically unloaded thus resulting in a poor material utilization rate. Since bending stiffness is per se significantly lower than axial stiffness, the design of floor slabs is typically governed by deflection limits under out-of-plane loading, which causes significant oversizing. In addition, structures are typically oversized since they are designed to take extreme loading events, which in practice occur only for a small part of the service life. The ongoing climate crisis, the expected world population growth and associated resource scarcity call for new methods and solutions to build material-efficient structures that cause minimum greenhouse gas emissions. Employing adaptation strategies is a promising solution. By integrating structures with components such as sensors, actuators and control units ­ stress and deformation caused by live loads can be reduced actively, which enables significant material savings. Previous work carried out at the University of Stuttgart within the Collaborative Research Center 1244 has demonstrated that it is possible to compensate deflections by integrating fluidic actuators in beam structures subjected to bending. However, it is not obvious how to transfer actuation concepts employed in beams to floor slabs due to multi-axial load-transfer behaviour. In this work, fluidic actuators are strategically integrated into floor slabs to employ multi-axial transfer to counteract the effect of out-of-plane loading. This research also addresses the choice of an optimal layout of the actuators. Numerical simulations of different actuation concepts, such as uniaxial and biaxial actuation have been carried out to derive influence surfaces. The relationship between principal moments and the effect of actuation is quantified numerically. Examples are provided to show how influence surfaces can be employed to select suitable actuation strategies. Results show that displacements can be efficiently compensated through a combination of uniaxial and biaxial actuation

Enteric dysfunctions in experimental Parkinson's disease: alterations of excitatory cholinergic neurotransmission regulating colonic motility in rats

Parkinson's disease (PD) is frequently associated with gastrointestinal symptoms, mostly represented by constipation and defecatory dysfunctions. This study examined the impact of central dopaminergic denervation, induced by injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle, on distal colonic excitatory cholinergic neuromotor activity in rats. Animals were euthanized 4 and 8 weeks after 6-OHDA injection. In vivo colonic transit was evaluated by radiological assay. Electrically and carbachol-induced cholinergic contractions were recorded in vitro from longitudinal and circular muscle colonic preparations, while acetylcholine levels were assayed in their incubation media. Choline acetyltransferase (ChAT), HuC/D (pan-neuronal marker), muscarinic M2 and M3 receptors. As compared with control rats, at week 4 6-OHDA-treated animals displayed the following changes: decreased in vivo colonic transit rate; impaired electrically evoked neurogenic cholinergic contractions; enhanced carbachol-induced contractions; decreased basal and electrically stimulated acetylcholine release from colonic tissues; decreased ChAT immunopositivity in the neuromuscular layer; unchanged density of HuC/D immunoreactive myenteric neurons; increased expression of colonic muscarinic M2 and M3 receptors. The majority of such alterations were detected also at week 8 post-6-OHDA injection. These findings indicate that central nigrostriatal dopaminergic denervation is associated with an impaired excitatory neurotransmission characterized by a loss of myenteric neuronal ChAT positivity and decrease in acetylcholine release, resulting in a dysregulated smooth muscle motor activity, which likely contributes to the concomitant decrease in colonic transit rate

Alteration of colonic excitatory tachykininergic motility and enteric inflammation following dopaminergic nigrostriatal neurodegeneration

Background: Parkinson's disease (PD) is frequently associated with gastrointestinal (GI) symptoms, including constipation and defecatory dysfunctions. The mechanisms underlying such disorders are still largely unknown, although the occurrence of a bowel inflammatory condition has been hypothesized. This study examined the impact of central dopaminergic degeneration, induced by intranigral injection of 6-hydroxydopamine (6-OHDA), on distal colonic excitatory tachykininergic motility in rats. Methods: Animals were euthanized 4 and 8 weeks after 6-OHDA injection. Tachykininergic contractions, elicited by electrical stimulation or exogenous substance P (SP), were recorded in vitro from longitudinal muscle colonic preparations. SP, tachykininergic NK1 receptor, and glial fibrillary acidic protein (GFAP) expression, as well as the density of eosinophils and mast cells in the colonic wall, were examined by immunohistochemical analysis. Malondialdehyde (MDA, colorimetric assay), TNF, and IL-1 beta (ELISA assay) levels were also examined. The polarization of peritoneal macrophages was evaluated by real-time PCR. Results: In colonic preparations, electrically and SP-evoked tachykininergic contractions were increased in 6-OHDA rats. Immunohistochemistry displayed an increase in SP and GFAP levels in the myenteric plexus, as well as NK1 receptor expression in the colonic muscle layer of 6-OHDA rats. MDA, TNF, and IL-1 beta levels were increased also in colonic tissues from 6-OHDA rats. In 6-OHDA rats, the number of eosinophils and mast cells was increased as compared with control animals, and peritoneal macrophages polarized towards a pro-inflammatory phenotype. Conclusions: The results indicate that the induction of central nigrostriatal dopaminergic degeneration is followed by bowel inflammation associated with increased oxidative stress, increase in pro-inflammatory cytokine levels, activation of enteric glia and inflammatory cells, and enhancement of colonic excitatory tachykininergic motility