Post-AGB Stars in Globular Clusters and Galactic Halos

We discuss three aspects of post-AGB (PAGB) stars in old populations. (1) HST photometry of the nucleus of the planetary nebula (PN) K 648 in the globular cluster (GC) M15 implies a mass of 0.60 Msun, in contrast to the mean masses of white dwarfs in GCs of ~0.5 Msun. This suggests that K 648 is descended from a merged binary, and we infer that single Pop II stars do not produce visible PNe. (2) Yellow PAGB stars are the visually brightest stars in old populations (Mv ~ -3.3) and are easily recognizable because of their large Balmer jumps; thus they show great promise as a Pop II standard candle. Two yellow PAGB stars in the GC NGC 5986 have the same V magnitudes to within +/-0.05 mag, supporting an expected narrow luminosity function. (3) Using CCD photometry and a u filter lying below the Balmer jump, we have detected yellow PAGB stars in the halo of M31 and in its dwarf elliptical companion NGC 205. With the Milky Way zero point, we reproduce the Cepheid distance to M31, and find that NGC 205 is ~100 kpc further away than M31. The star counts imply a yellow PAGB lifetime of about 25,000 yr, and their luminosities imply masses near 0.53 Msun.Comment: 6 pages, 2 figures. To appear in proceedings of Torun, Poland, workshop on "Post-AGB Objects (Proto-Planetary Nebulae) as a Phase of Stellar Evolution," ed. S.K. Gorn

An Overview of Material Extrusion Troubleshooting

© 2020 by the authors. Material extrusion (ME) systems offer end-users with a more affordable and accessible additive manufacturing (AM) technology compared to other processes in the market. ME is often used to quickly produce low-cost prototyping with the freedom of scalability where parts can be produced in different geometries, quantities and sizes. As the use of desktop ME machines has gained widespread adoption, this review paper discusses the key design strategies and considerations to produce high quality ME parts, as well as providing actional advice to aid end-users in quickly identifying and efficiently troubleshooting issues since current information is often fragmented and incomplete. The systemic issues and solutions concerning desktop ME processes discussed are not machine-specific, covering categories according to printer-associated, deposition-associated and print quality problems. The findings show that the majority of issues are associated with incorrect printer calibration and parameters, hardware, material, Computer Aided Design (CAD) model and/or slicing settings. A chart for an overview of ME troubleshooting is presented allowing designers and engineers to straightforwardly determine the possible contributing factors to a particular problem

Star Formation Rate Indicators in Wide-Field Infrared Survey Preliminary Release

With the goal of investigating the degree to which theMIR luminosity in theWidefield Infrared Survey Explorer (WISE) traces the SFR, we analyze 3.4, 4.6, 12 and 22 {\mu}m data in a sample of {\guillemotright} 140,000 star-forming galaxies or star-forming regions covering a wide range in metallicity 7.66 < 12 + log(O/H) < 9.46, with redshift z < 0.4. These star-forming galaxies or star-forming regions are selected by matching the WISE Preliminary Release Catalog with the star-forming galaxy Catalog in SDSS DR8 provided by JHU/MPA 1.We study the relationship between the luminosity at 3.4, 4.6, 12 and 22 {\mu}m from WISE and H\alpha luminosity in SDSS DR8. From these comparisons, we derive reference SFR indicators for use in our analysis. Linear correlations between SFR and the 3.4, 4.6, 12 and 22 {\mu}m luminosity are found, and calibrations of SFRs based on L(3.4), L(4.6), L(12) and L(22) are proposed. The calibrations hold for galaxies with verified spectral observations. The dispersion in the relation between 3.4, 4.6, 12 and 22 {\mu}m luminosity and SFR relates to the galaxy's properties, such as 4000 {\deg}A break and galaxy color.Comment: 10 pages, 3 figure

Spina bifida-predisposing heterozygous mutations in Planar Cell Polarity genes and Zic2 reduce bone mass in young mice

Fractures are a common comorbidity in children with the neural tube defect (NTD) spina bifida. Mutations in the Wnt/planar cell polarity (PCP) pathway contribute to NTDs in humans and mice, but whether this pathway independently determines bone mass is poorly understood. Here, we first confirmed that core Wnt/PCP components are expressed in osteoblasts and osteoclasts in vitro. In vivo, we performed detailed µCT comparisons of bone structure in tibiae from young male mice heterozygous for NTD-associated mutations versus WT littermates. PCP signalling disruption caused by Vangl2 (Vangl2Lp/+) or Celsr1 (Celsr1Crsh/+) mutations significantly reduced trabecular bone mass and distal tibial cortical thickness. NTD-associated mutations in non-PCP transcription factors were also investigated. Pax3 mutation (Pax3Sp2H/+) had minimal effects on bone mass. Zic2 mutation (Zic2Ku/+) significantly altered the position of the tibia/fibula junction and diminished cortical bone in the proximal tibia. Beyond these genes, we bioinformatically documented the known extent of shared genetic networks between NTDs and bone properties. 46 genes involved in neural tube closure are annotated with bone-related ontologies. These findings document shared genetic networks between spina bifida risk and bone structure, including PCP components and Zic2. Genetic variants which predispose to spina bifida may therefore independently diminish bone mass

Small cell carcinoma arising in Barrett's esophagus: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Gastrointestinal tract small cell carcinoma is an infrequent and aggressive neoplasm that represents 0.1–1% of gastrointestinal malignancies. Very few cases of small cell esophageal carcinoma arising in Barrett's esophagus have been reported in the literature. An extremely rare case of primary small cell carcinoma of the distal third of the esophagus arising from dysplastic Barrett's esophagus is herein presented.</p> <p>Case presentation</p> <p>A 62-year-old man with gastroesophageal reflux history presented with epigastric pain, epigastric fullness, dysphagia, anorexia, and weight loss. Esophagogastroscopy revealed an ulceroproliferative, intraluminar mass in the distal esophagus obstructing the esophageal lumen. Biopsy showed small cell esophageal carcinoma. Contrast-enhanced chest and abdominal computed tomography demonstrated a large tumor of the distal third of the esophagus without any lymphadenopathy or distant metastasis. Preoperative chemotherapy with cisplatine and etoposide for 3 months resulted in a significant reduction of the tumor. After en block esophagectomy with two field lymph node dissection, proximal gastrectomy, and cervical esophagogastric anastomosis, the patient was discharged on the 14^thpostoperative day. Histopathology revealed a primary small cell carcinoma of the distal third of the esophagus arising from dysplastic Barrett's esophagus. The patient received another 3 month course of postoperative chemotherapy with the same agents and remained free of disease at 12 month review.</p> <p>Conclusion</p> <p>Although small cell esophageal carcinoma is rare and its association with dysplastic Barrett's esophagus is extremely infrequent, the high carcinogenic risk of Barrett's epithelium should be kept in mind. Prognosis is quite unfavorable; a better prognosis might be possible with early diagnosis and treatment strategies incorporating chemotherapy along with oncological radical surgery and/or radiotherapy as part of a multimodality approach. Since treatment protocols are not well established due to the rarity of the neoplasm, multi-institutional studies are needed to obtain sufficiently large populations for investigation and optimization of therapy of the disease.</p

Phase transitions in biological membranes

Native membranes of biological cells display melting transitions of their lipids at a temperature of 10-20 degrees below body temperature. Such transitions can be observed in various bacterial cells, in nerves, in cancer cells, but also in lung surfactant. It seems as if the presence of transitions slightly below physiological temperature is a generic property of most cells. They are important because they influence many physical properties of the membranes. At the transition temperature, membranes display a larger permeability that is accompanied by ion-channel-like phenomena even in the complete absence of proteins. Membranes are softer, which implies that phenomena such as endocytosis and exocytosis are facilitated. Mechanical signal propagation phenomena related to nerve pulses are strongly enhanced. The position of transitions can be affected by changes in temperature, pressure, pH and salt concentration or by the presence of anesthetics. Thus, even at physiological temperature, these transitions are of relevance. There position and thereby the physical properties of the membrane can be controlled by changes in the intensive thermodynamic variables. Here, we review some of the experimental findings and the thermodynamics that describes the control of the membrane function.Comment: 23 pages, 15 figure

Microparticle-mediated transfer of the viral receptors CAR and CD46, and the CFTR channel in a CHO cell model confers new functions to target cells

Cell microparticles (MPs) released in the extracellular milieu can embark plasma membrane and intracellular components which are specific of their cellular origin, and transfer them to target cells. The MP-mediated, cell-to-cell transfer of three human membrane glycoproteins of different degrees of complexity was investigated in the present study, using a CHO cell model system. We first tested the delivery of CAR and CD46, two monospanins which act as adenovirus receptors, to target CHO cells. CHO cells lack CAR and CD46, high affinity receptors for human adenovirus serotype 5 (HAdV5), and serotype 35 (HAdV35), respectively. We found that MPs derived from CHO cells (MP-donor cells) constitutively expressing CAR (MP-CAR) or CD46 (MP-CD46) were able to transfer CAR and CD46 to target CHO cells, and conferred selective permissiveness to HAdV5 and HAdV35. In addition, target CHO cells incubated with MP-CD46 acquired the CD46-associated function in complement regulation. We also explored the MP-mediated delivery of a dodecaspanin membrane glycoprotein, the CFTR to target CHO cells. CFTR functions as a chloride channel in human cells and is implicated in the genetic disease cystic fibrosis. Target CHO cells incubated with MPs produced by CHO cells constitutively expressing GFP-tagged CFTR (MP-GFP-CFTR) were found to gain a new cellular function, the chloride channel activity associated to CFTR. Time-course analysis of the appearance of GFP-CFTR in target cells suggested that MPs could achieve the delivery of CFTR to target cells via two mechanisms: the transfer of mature, membrane-inserted CFTR glycoprotein, and the transfer of CFTR-encoding mRNA. These results confirmed that cell-derived MPs represent a new class of promising therapeutic vehicles for the delivery of bioactive macromolecules, proteins or mRNAs, the latter exerting the desired therapeutic effect in target cells via de novo synthesis of their encoded proteins

Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.Jennifer R. Bellon, Frank Schmid, Dimitra L. Capone, Barbara L. Dunn, Paul J. Chamber

A minimally invasive immunocytochemical approach to early detection of oral squamous cell carcinoma and dysplasia

Squamous dysplasia of the oral cavity indicates increased risk of progression to squamous cell carcinoma (SCC). An important advance would be the development of a minimally invasive assay for identification of oral SCC and dysplasia. We have investigated the suitability in this context of immunostaining oral smears for minichromosome maintainance proteins (MCMs), sensitive and specific biomarkers of cell cycle entry. Immunohistochemical examination of 66 oral tissue samples showed a greater frequency of Mcm-2 expression in surface layers of moderate/severe dysplasia and SCC compared to benign keratosis/mild dysplasia. Immunocytochemistry for Mcm-2/Mcm-5 was performed on 101 oral smears. Conventional smears included 23 from normal mucosa, benign proliferative disease and mild dysplasia, all of which were MCM negative. Of 52 conventional smears of SCC tissue samples, 18 were inadequate. However, MCM-positive cells were present in 33/34 adequate samples. Of 26 liquid-based cytology smears, 19 out of 20 smears from SCC were adequate and all were MCM positive. Six smears from benign lesions were adequate and MCM negative. We conclude that MCMs are promising markers for early detection of oral SCC and dysplasia, particularly in a liquid-based cytology platform. Detection of MCMs would be amenable to automation and potentially applicable in the developing world. Further studies are now warranted

Incidence, Risk Factors, and Impact of Severe Neutropenia After Hyperthermic Intraperitoneal Mitomycin C

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are considered the standard of care for patients with peritoneal dissemination of appendiceal cancer and are increasingly being evaluated for use in patients with carcinomatosis from colon cancer. Mitomycin C (MMC) is one of the most frequently used HIPEC agents in the management of peritoneal-based gastrointestinal malignancies. This study analyzes the incidence and risk factors for developing neutropenia following MMC-HIPEC combined with CRS. All patients undergoing CRS and MMC-HIPEC for appendiceal cancer between January 1993 and October 2006 were retrospectively reviewed. Logistic regression was used to identify risk factors for the development of neutropenia, defined as an absolute neutrophil count (ANC) &lt;1,000/mm3. One hundred and twenty MMC-HIPEC were performed in 117 patients with appendiceal cancer. The incidence of neutropenia was 39%. Neutropenia occurred in 57.6% of female and 21.3% of male patients (p &lt; 0.0001). Female gender and MMC dose per body surface area (BSA) were independent risk factors for neutropenia on multivariable logistic regression [odds ratio (OR) of neutropenia in females = 3.58 (95% confidence interval, CI: 1.52, 8.43); OR for 5 unit (mg/m2) increase in MMC dose per BSA = 3.37 (95% CI: 1.72, 6.63)]. Neutropenia did not increase the risk of mortality, postoperative infection or length of hospital stay. Neutropenia is a frequent complication associated with MMC-HIPEC. Female sex and MMC dose per BSA are independent risk factors for neutropenia. These differences must be considered in the management of patients undergoing MMC-HIPEC to minimize the toxicity of the procedure