A study of the kinematics and binary-induced shaping of the planetary nebula HaTr 4

We present the first detailed spatio-kinematical analysis and modelling of the planetary nebula HaTr 4, one of few known to contain a post-common-envelope central star system. Common envelope evolution is believed to play an important role in the shaping of planetary nebulae, but the exact nature of this role is yet to be understood. High spatial- and spectral- resolution spectroscopy of the [OIII]5007 nebular line obtained with VLT-UVES are presented alongside deep narrowband Ha+[NII]6584 imagery obtained using EMMI-NTT, and together the two are used to derive the three-dimensional morphology of HaTr 4. The nebula is found to display an extended ovoid morphology with an enhanced equatorial region consistent with a toroidal waist - a feature believed to be typical amongst planetary nebulae with post-common-envelope central stars. The nebular symmetry axis is found to lie perpendicular to the orbital plane of the central binary, concordant with the idea that the formation and evolution of HaTr 4 has been strongly influenced by its central binary.Comment: 9 pages, 5 figures, accepted for publication in MNRA

The post-common-envelope, binary central star of the planetary nebula Hen 2-11

We present a detailed photometric study of the central star system of the planetary nebula Hen 2-11, selected for study because of its low-ionisation filaments and bipolar morphology - traits which have been strongly linked with central star binarity. Photometric monitoring with NTT-EFOSC2 reveals a highly irradiated, double-eclipsing, post-common-envelope system with a period of 0.609 d. Modelling of the lightcurve indicates that the nebular progenitor is extremely hot, while the secondary in the system is probably a K-type main sequence star. The chemical composition of the nebula is analysed, showing Hen 2-11 to be a medium-excitation non-Type I nebula. A simple photoionisation model is constructed determining abundance ratios of C/O and N/O which would be consistent with the common-envelope cutting short the AGB evolution of the nebular progenitor. The detection of a post-common-envelope binary system at the heart of Hen 2-11 further strengthens the link between binary progeny and the formation of axisymmetric planetary nebulae with patterns of low-ionisation filaments, clearly demonstrating their use as morphological indicators of central star binarity.Comment: Accepted for publication in A&A. 9 pages, 5 figures, 4 table

The tilting hygrometer: A new form of absorption hygrometer

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XXII. On the ionizing processes at a point discharging in air

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Future targets in the management of systemic sclerosis

CTDs—such as SSc and SLE and related rheumatic diseases such as RA—have complex, underlying pathogeneses that include fibrosis, vascular dysfunction, activation of the immune system and inflammation. Although some current therapies for SSc offer benefits to patients, there is a clear need to investigate potential therapeutic targets. However, the breadth and diversity of cellular pathways and mediators implicated in these diseases, coupled with inherent redundancies in these systems, has made pre-clinical investigation difficult. Despite this, recent advances have been made in elucidating the immunological aspects of CTD, including the roles of B cells, T cells, matrix-remodelling cells and autoantibodies, enabling novel therapeutic approaches including immunoablation to be investigated. The mechanisms underlying the fibrosis that characterizes SSc are also becoming clearer; and as the putative events that trigger excessive collagen deposition are identified, so too are potential junctures at which these aberrant processes may be deactivated. Progress is also being made in understanding the vasculopathy in SSc, and the potential benefits of antioxidants and endothelin receptor antagonists. There have been some significant advances in the treatments available to SSc patients; however, this spectrum of diseases remains challenging, and continues in some cases to be associated with high morbidity, increased mortality and poor prognosi

Haematopoietic stem cell transplantation for poor-prognosis systemic sclerosis

Haematopoietic stem cell transplantation (HSCT) following intensive immune suppression has been used in >2000 patients with severe autoimmune diseases for 18 years, including 300 with SSc. The concept is to profoundly reduce the bulk of auto-aggressive immune competent cells and then rescue the patient's ablated haematopoiesis via an autologous HSCT. An early analysis of uncontrolled phase I/II data suggested that approximately one-third of these achieved a substantial improvement, with a relapse rate of 25% and a treatment-related mortality ranging from 6% to 23% across different studies. These early results led to three prospective randomized controlled trials, two of which are completed, confirming that HSCT shows clear advantages over conventional immunosuppression, but with significant toxicity. In some patients, sustained complete normalization of skin changes, reversal of positive autoantibody status and withdrawal of immunosuppressive medication were observed. These results attest to the profound effects of HSC

OH yields from the CH3CO+O-2 reaction using an internal standard

Laser flash photolysis of CH3C(O)OH at 248 nm was used to create equal zero time yields of CH3CO and OH. The absolute OH yield from the CH3CO + O2 (+M) reaction was determined by following the OH temporal profile using the zero time OH concentration as an internal standard. The OH yield from CH3CO + O2 (+M) was observed to decrease with increasing pressure with an extrapolated zero pressure yield close to unity (1.1 ± 0.2, quoted uncertainties correspond to 95% confidence limits). The results are in quantitative agreement with those obtained from 248 nm acetone photolysis in the presence of O2

Forest Change in the Driftless Area of the Midwest: From a Preferred to Undesirable Future

In the midwestern and eastern U.S., oaks (Quercus spp.) have been a dominant component of forests for at least the last 10,000 years, providing vital habitat for numerous wildlife and plant species that have adapted to oak forest conditions. However, the current state of these oak systems, in which there has been a general lack of successful oak regeneration and recruitment and an increase in the relative dominance of mesophytic species, may be nearing critical thresholds. If reached, restoring oak systems through natural regeneration and other methods, such as prescribed fire, may become especially challenging if not impossible. An understanding of spatial variation in oak dominance over time can inform and potentially improve the efficacy of intervention strategies. Using Public Land Survey and Forest Inventory and Analysis (FIA) inventories, we evaluated changes in the composition of timberland across ecoregional subsections in the Driftless Area of the Midwest at three time periods (pre-settlement 1800s, 1990s, and 2000s). We identified an overall decrease in oak dominance, and particularly dominance of the white oak (Quercus alba L., Q. macrocarpa Michx., and Q. bicolor Willd.) species group since the presettlement era, and an increase in other eastern soft hardwoods. Within the last 20 years, both the red oak (Q. rubra L., Q. ellipsoidalis E.J. Hill and Q. velutina Lam.) and white oak species groups decreased in dominance, with an increase in hard maple-basswood (A. saccharum Marsh., A. nigra L., and Tilia americana L.) species group dominance, indicating further mesophication of forests in the region. However, we found a notable decrease in hard maple-basswood relative dominance within the small diameter class across most of the regions within the last 10–20 years, with an increase in dominance of other, non-oak, species. Our findings complement qualitative evidence from interviews with natural resource professionals from the region and offer further information on the potential for forest conversion to ‘‘undesirable’’ forest conditions, as identified as a source of concern by some professionals. There was spatial variation in these trends, however, with some pronounced differences across adjacent state boundaries. The variation in forest change across state boundaries suggests the role of state-level socioeconomic and policy factors in affecting forest conditions, and thus the potential for a targeted and timely approach to promoting preferred pathways of change

Platelet lysate as a serum substitute for 2D static and 3D perfusion culture of stromal vascular fraction cells from human adipose tissue

Fetal bovine serum (FBS) and fibroblast growth factor (FGF)-2 are key supplements for the culture of stromal vascular fraction (SVF) cells from adipose tissue, both for typical monolayer (2D) expansion and for streamlined generation of osteogenic-vasculogenic grafts in 3D perfusion culture. The present study investigates whether factors present in human platelet lysate (PL) could substitute for FBS and FGF-2 in 2D and 3D culture models of SVF cells from human lipoaspirates. SVF cells were grown in medium supplemented with 10% FBS+FGF-2 or with 5% PL. In 2D cultures, PL initially supported SVF cell proliferation, but resulted in growth arrest shortly after the first passage. Freshly isolated SVF cells cultured with both media under perfusion for 5 days within 3D ceramic scaffolds induced bone formation after subcutaneous implantation in nude mice. However, blood vessels of donor origin were generated only using FBS+FGF-2-cultured cells. This was unexpected, because the proportion of CD34+/CD31+ endothelial lineage cells was significantly higher with PL than that of FBS+FGF-2 (33% vs. 3%, respectively). These results support the use of PL as a substitute of FBS+FGF-2 for short-term culture of human SVF cells, and indicate that more specific serum-free formulations are required to maintain a functionally vasculogenic fraction of SVF cells expanded under 3D perfusion