Seeds and the City: The Interdependence of Zoochory and Ecosystem Dynamics in Urban Environments

The increasing urban sprawl has contributed to the extensive fragmentation and reduction of natural habitat worldwide. Urbanization has a range of adverse effects on ecosystem functioning, including the disruption of plant dispersal processes across the landscape. Urban fragmentation can alter the distance and directionality of dispersal, leading to disrupted gene flow among populations. The dispersal processes of plants that rely on animal-mediated dispersal (zoochory) may be disproportionately affected by urbanization, as many animals avoid urban areas or restrict their movements within urban habitats. This could alter the efficiency of animal dispersal vectors and modify seed movements across urban habitats. While recent studies suggest that seed dispersal networks can be complex and dynamic even in highly managed green areas with relatively low biodiversity, zoochory in urban environments remains understudied. We synthesize the existing literature on zoochory in urban environments and place the findings in the context of ecosystem dynamics. We assess the ecological and evolutionary consequences for seed dispersal, following urbanization, by considering how zoochory is affected by specific features of urban environments. These include the complexity of habitats with varying continuity; high disturbance and intense management; a high proportion of alien species combined with low natural biodiversity; animal behavioral adjustments in different urban settings; and rapid evolutionary change due to urbanization. We conclude that (1) urbanization can disrupt and alter zoochory processes; and (2) successful zoochory can, in turn, alleviate or worsen the challenges to ecosystem dynamics originating from increased urbanization. The dynamic urban seed dispersal networks are emerging as useful models for the adaptability of seed dispersal communities. Their study can also shed light on eco-evolutionary processes under anthropogenic selective pressures, including species interactions. Finally, urban zoochory processes are critical to the functioning of urban ecosystems and as such, constitute an important ecosystem service with management implications. We propose directions for further research into urban zoochory processes to ensure the maintenance of ecosystem dynamics as urbanization continues

Primary Prophylaxis for Gastrointestinal Bleeding in Children With Biliary Atresia and Portal Hypertension Candidates for Liver Transplantation: A Single-Center Experience

Background. Cirrhosis for biliary atresia (BA) is associated with risk of gastrointestinal bleeding (GB) from gastroesophageal varices due to portal hypertension. Primary prophylaxis of GB is controversial in children who are candidates for liver transplantation (LT). The aim of the study was to define the management of gastroesophageal varices and to identify the benefit of primary prophylaxis for GB in BA children waiting for LT.Methods. A retrospective single-center study including all BA children listed for LT in 2008-2016. Clinical, endoscopical, and biochemical data were analyzed.Results. Of 82 children, 50 (61%) did not receive primary prophylaxis and did not present any episode of bleeding, 16 (19.5%) underwent primary prophylaxis, and 16 (19.5%) presented spontaneous GB and received secondary prophylaxis. Children without primary prophylaxis and GB were younger than patients with primary prophylaxis and those with GB (7.7 years [range, 4.1-37.9 years] vs 11.2 years [range, 5.1-43 years]; P = .03 vs 10.7 years [range, 6.9-39.9 years], respectively; P = .004). Seventy-five percent of GB occurred in children older than 8 months. Fifteen (93.8%) children with GB presented esophageal varices (grade III = 10 [62.5%]) and 10 (62.5%) required endoscopic treatments, consisting mainly of sclerotherapy. Median time to LT was similar for children with or without bleeding (2 months [range, 0-17.7 months] vs 2.2 months [0-17.9 months], respectively; P = .89). After 45.5 months (range, 13.7-105.5 months) of follow-up, the overall patient survival was 97.6%. At the intention-to-treat analysis, the survival rate was 100% for patients without bleeding episode and 87.5% for children with GB (P = .16).Conclusions. Despite the risk of GB being not clinically predictable in children with BA waiting for LT, our experience suggests that primary prophylaxis of GB might be unnecessary in children younger than 6 months, while it should be considered in older children. Thus, the occurrence of GB does not delay the timing of transplantation

Same donor laparoscopic liver and kidney procurement for sequential living donor liver-kidney transplantation in primary hyperoxaluria type i

Background: Sequential liver-kidney transplantation (SeqLKT) from the same living donor has shown excellent results in children with primary hyperoxaluria type 1 (PH1), yet its experience is limited due to the invasiveness of two major procedures for liver-kidney procurement in a single donor. Despite laparoscopic nephrectomy and hepatic left lateral sectionectomy (LLS) being considered standard procedures in living donation, the sequential use of the two laparoscopic approaches in the same living donor has never been reported. Methods: Herein, we present the first two case series of laparoscopic liver-kidney procurement in the same living donor for SeqLKT in children with PH1 and review of the current literature on this topic. Results: In the first case, a 15-month-old boy received a SeqLKT from his 32-year-old mother, who underwent a laparoscopic LLS and, after 8 months, a laparoscopic left nephrectomy. In the second case, a 34-month-old boy received a SeqLKT from his 40-year-old father who underwent laparoscopic LLS followed by hand-assisted right nephrectomy after 4 months. Both donors had uneventful postoperative courses and were discharged within 5 days from each surgery. The first recipient had no complication; the second child after liver transplantation developed a partial thrombosis of the inferior vena cava, which did not preclude the sequential kidney transplantation. After 12 months, donors and recipients displayed normal liver and renal functions. Conclusions: Sequential laparoscopic liver-kidney procurement in the same living donor is safe and feasible, and might be considered as a possible strategy to promote SeqLKT in children with PH1 from the same living donor

Identification of a novel protein-protein interaction motif mediating interaction of GPCR-associated sorting proteins with G protein-coupled receptors

<div><p>GPCR desensitization and down-regulation are considered key molecular events underlying the development of tolerance <i>in vivo</i>. Among the many regulatory proteins that are involved in these complex processes, GASP-1 have been shown to participate to the sorting of several receptors toward the degradation pathway. This protein belongs to the recently identified GPCR-associated sorting proteins (GASPs) family that comprises ten members for which structural and functional details are poorly documented. We present here a detailed structure–function relationship analysis of the molecular interaction between GASPs and a panel of GPCRs. In a first step, GST-pull down experiments revealed that all the tested GASPs display significant interactions with a wide range of GPCRs. Importantly, the different GASP members exhibiting the strongest interaction properties were also characterized by the presence of a small, highly conserved and repeated “GASP motif” of 15 amino acids. We further showed using GST-pull down, surface plasmon resonance and co-immunoprecipitation experiments that the central domain of GASP-1, which contains 22 GASP motifs, is essential for the interaction with GPCRs. We then used site directed mutagenesis and competition experiments with synthetic peptides to demonstrate that the GASP motif, and particularly its highly conserved core sequence SWFW, is critically involved in the interaction with GPCRs. Overall, our data show that several members of the GASP family interact with GPCRs and highlight the presence within GASPs of a novel protein-protein interaction motif that might represent a new target to investigate the involvement of GASPs in the modulation of the activity of GPCRs.</p> </div

A fine-grained silicon detector for high-energy gamma-ray astrophysics

We propose a silicon telescope to be placed in a satellite for the search of g-ray sources in the energy range between 25 MeV and 100 GeV. The proposed experiment will have an area of 2500 cm2, an energy resolution ranging from 7% to 8% and an angular resolution from 0.2 and 0.1 degrees between 1 GeV and 10 GeV. The telescope is based on the use of silicon strip detectors. Together with the energy measurement, a calorimeter of this type allows the determination of the particle type and its arrival direction, through the analysis of the spatial and energetic distribution of the electromagnetic shower produced. Detectors based on silicon technology have many advantages for space applications: no gas refilling system or high voltages, no need of photomultipliers (low consumption), short dead time, possibility of selftriggering. The GILDA project has been designed having in mind the weight limitation of 400 kg required by the Resource-01 satellite and it is carried out in the framework of the RIM (Russian Italian Mission) program. The launch is foreseen for the beginning of the next century

Ethanol‐Lock Therapy for the Prevention of Central Venous Access Device Infections in Pediatric Patients With Intestinal Failure

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141158/1/jpen0067.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141158/2/jpen0067-sup-0001.pd

Silicon calorimeter for cosmic antimatter search

Abstract The silicon sampling calorimeter presented is conceived as a fine grained imaging device to carry out studies of the anti-matter component in the primary cosmic radiation; it will be used in balloon payload program starting in 1993. The first sampling layer (48×48 cm2) of this silicon calorimeter has been completed and successfully tested. We report the first results form studies performed at the CERN PS t7 beam. The complete calorimeter contains 20 xy sampling layers (strip pitch 3.6 mm) interleaved with 19 showering material planes (tungsten 0.5 X0). This allows to picture the transverse distributions of the shower in both coordinates at each sampling. The outstanding imaging capabilities reflects in high particle identification power. Preliminary results from beam tests performed with antiprotons at 3.5 GeV on a tower prototype of the calorimeter are reported

A silicon imaging calorimeter prototype for antimatter search in space: experimental results

Abstract This report presents the results obtained with a prototype silicon-tungsten (Si-W) electromagnetic calorimeter, conceived as a fine-grained imaging device to carry out studies of the antimatter component in primary cosmic radiation. The calorimeter prototype contains 20 x , y sampling layers interleaved with 19 showering material planes. One sensitive layer is obtained with two silicon strip detectors (Si-D) (60 × 60) mm 2 , each divided into 16 strips, 3.6 mm wide; the two detectors are assembled back to back with perpendicular strips. This allows the transverse distributions of the shower in both coordinates at each sampling (0.5 X 0 ) to be pictured. The basic characteristics of the design and the experimental results obtained on a test beam at the CERN proton synchrotron (PS) for electrons and pions are reported. The main results presented are the response of the calorimeter to the electron at various energies (1–7 GeV), and the transverse shower profiles at different calorimeter depths as well as the patterns of the electromagnetic shower and those of the interacting and non-interacting pions. The capability of the calorimeter in measuring the direction of the incoming electromagnetic particle from the pattern of the shower has been evaluated at different energies. These results are encouraging in view of the possible use of this detector to search for high-energy γ sources in space