Reproductive competition between polygynous parasite queens in ant colonies

BACKGROUND: Evaluation of percutaneous tracheostomy (PT) with the guide wire dilating forceps (GWDF) technique. METHODS: Prospective study of perioperative complications, retrospective analysis of early and late complications in an ICU in a teaching university hospital. RESULTS: The success rate of the procedure was 96.5%. The average procedure time in 171 consecutive patients was 5.0 min. Perioperative complications requiring surgical or medical intervention occurred in 6.4% of 171 patients. This included conversion to surgical tracheostomy, which was necessary in six patients (3.5%). Major complications while being cannulated occurred in 2.4% of 164 patients but seemed mostly unrelated with the GWDF technique itself. Late complications (after decannulation) were mostly minor and occurred in 22.6% of 106 patients. Only one patient (0.9%) had a symptomatic tracheal stenosis developed. CONCLUSION: Percutaneous tracheostomy with the guide wire dilating forceps technique is easy to perform at the bedside with few late complications. However, in our study, perioperative and immediate postoperative bleeding complications (minor and major) occur quite often

To what extent has the last two decades seen significant progress in the management of older patients with head and neck cancer?

Introduction: Life expectancy is rising and consequently also the number of older patients with head and neck cancer. Different treatment regimens are often applied for older patients. The aim of this study is to investigate how treatment patterns and survival rates have changed over the past 20 years in older patients with head and neck squamous cell carcinoma (HNSCC). Materials: Patient and tumour characteristics, treatment and 5-year survival data from the Netherlands Cancer Registry of patients aged >60 years diagnosed with HNSCC in 1990-1995 and 2010-2015 were compared using chi-square test and relative survival analysis. Results: Data of 14,114 patients were analyzed. Oral cavity cancer treatment did not change over time, while survival improved from 54% to 58% (p 1/4 0.03). Oropharyngeal and hypopharyngeal cancer treatment shifted towards non-surgical, with survival improving from 31% to 51% (p < 0.01) and 26% to 34% (p < 0.01), respectively. Laryngeal cancer treatment changed towards surgery in stage I and non-surgical treatment in stage III and IV disease. Survival in laryngeal cancer stage I remained stable and favorable at a relative survival rate of around 90%. Survival non-significantly changed from 54% to 49% for stage III disease and from 37% to 33% for disease. Conclusion: Relative survival increased for all head and neck cancer sites in older patients, except for laryngeal cancer. For oropharyngeal, hypopharyngeal and advanced laryngeal cancer, a shift towards non-surgical treatment modalities was observed. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY licens

Coherent Backscattering of Light by Cold Atoms

Light propagating in an optically thick sample experiences multiple scattering. It is now known that interferences alter this propagation, leading to an enhanced backscattering, a manifestation of weak localization of light in such diffuse samples. This phenomenon has been extensively studied with classical scatterers. In this letter we report the first experimental evidence for coherent backscattering of light in a laser-cooled gas of Rubidium atoms.Comment: 4 pages REVTEX, 1 page color image GIF, accepted for publication in Phys. Rev. Let

A Post-AGB Star in the Small Magellanic Cloud Observed with the Spitzer Infrared Spectrograph

We have observed an evolved star with a rare combination of spectral features, MSX SMC 029, in the Small Magellanic Cloud (SMC) using the low-resolution modules of the Infrared Spectrograph on the Spitzer Space Telescope. A cool dust continuum dominates the spectrum of MSX SMC 029. The spectrum also shows both emission from polycyclic aromatic hydrocarbons (PAHs) and absorption at 13.7 micron from C2H2, a juxtaposition seen in only two other sources, AFGL 2688 and IRAS 13416-6243, both post-asymptotic giant branch (AGB) objects. As in these sources, the PAH spectrum has the unusual trait that the peak emission in the 7-9 micron complex lies beyond 8.0 micron. In addition, the 8.6 micron feature has an intensity as strong as the C-C modes which normally peak between 7.7 and 7.9 micron. The relative flux of the feature at 11.3 micron to that at 8 micron suggests that the PAHs in MSX SMC 029 either have a low ionization fraction or are largely unprocessed. The 13-16 micron wavelength region shows strong absorption features similar to those observed in the post-AGB objects AFGL 618 and SMP LMC 11. This broad absorption may arise from the same molecules which have been identified in those sources: C2H2, C4H2, HC3N, and C6H6. The similarities between MSX SMC 029, AFGL 2688, and AFGL 618 lead us to conclude that MSX SMC 029 has evolved off the AGB in only the past few hundred years, making it the third post-AGB object identified in the SMC.Comment: 4 figures, Fig. 4 color; to appear in the 20 November 2006 Astrophysical Journal Letter

Meta-Analysis of Pulmonary Transcriptomes from Differently Primed Mice Identifies Molecular Signatures to Differentiate Immune Responses following Bordetella pertussis

Respiratory infection with Bordetella pertussis leads to severe effects in the lungs. The resulting immunity and also immunization with pertussis vaccines protect against disease, but the induced type of immunity and longevity of the response are distinct. In this study the effects of priming, by either vaccination or infection, on a subsequent pathogen encounter were studied. To that end, three postchallenge transcriptome datasets of previously primed mice were combined and compared to the responses in unprimed control mice. In total, 205 genes showed different transcription activity. A coexpression network analysis assembled these genes into 27 clusters, combined into six groups with overlapping biological function. Local pulmonary immunity was only present in mice with infection-induced immunity. Complement-mediated responses were more prominent in mice immunized with an outer membrane vesicle pertussis vaccine than in mice that received a whole-cell pertussis vaccine. Additionally, 46 genes encoding for secreted proteins may serve as markers in blood for the degree of protection (Cxcl9, Gp2, and Pla2g2d), intensity of infection (Retnla, Saa3, Il6, and Il1b), or adaptive recall responses (Ighg, C1qb). The molecular signatures elucidated in this study contribute to better understanding of functional interactions in challenge-induced responses in relation to pertussis immunity

Full nonperturbative QCD simulations with 2+1 flavors of improved staggered quarks

Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the development of new algorithms and the rapid increase in computing power available to lattice gauge theorists. In this article we describe simulations of full QCD using the improved staggered quark formalism, ``asqtad'' fermions. These simulations were carried out with two degenerate flavors of light quarks (up and down) and with one heavier flavor, the strange quark. Several light quark masses, down to about 3 times the physical light quark mass, and six lattice spacings have been used. These enable controlled continuum and chiral extrapolations of many low energy QCD observables. We review the improved staggered formalism, emphasizing both advantages and drawbacks. In particular, we review the procedure for removing unwanted staggered species in the continuum limit. We then describe the asqtad lattice ensembles created by the MILC Collaboration. All MILC lattice ensembles are publicly available, and they have been used extensively by a number of lattice gauge theory groups. We review physics results obtained with them, and discuss the impact of these results on phenomenology. Topics include the heavy quark potential, spectrum of light hadrons, quark masses, decay constant of light and heavy-light pseudoscalar mesons, semileptonic form factors, nucleon structure, scattering lengths and more. We conclude with a brief look at highly promising future prospects.Comment: 157 pages; prepared for Reviews of Modern Physics. v2: some rewriting throughout; references update

Controlled formation of metallic nanowires via Au nanoparticle ac trapping

Applying ac voltages, we trapped gold nanoparticles between microfabricated electrodes under well-defined conditions. We demonstrate that the nanoparticles can be controllably fused together to form homogeneous gold nanowires with pre-defined diameters and conductance values. Whereas electromigration is known to form a gap when a dc voltage is applied, this ac technique achieves the opposite, thereby completing the toolkit for the fabrication of nanoscale junctions.Comment: Nanotechnology 18, 235202 (2007

The effect of three-dimensional visualisation on performance in endoscopic sinus surgery:A clinical training study using surgical navigation for movement analysis in a randomised crossover design

Objectives: Endoscopic imaging techniques and endoscopic endonasal surgery (EES) expertise have evolved rapidly. Only few studies have assessed the effect of three-dimensional (3D) endoscopy on endoscopic sinus surgery (ESS). The present study aimed to objectively and subjectively assess the additional value of 3D high-definition (HD) endoscopy in ESS. Design: A randomized crossover study of endoscopic surgery performance, using five ESS tasks of varying complexity, performed on Thiel embalmed human specimens. Setting: Simulated surgical environment. Participants: Thirty participants, inexperienced in ESS. Main outcome measures: Performance was assessed using video imaging, surgical navigation and questionnaires. Main outcome measures were as follows: efficiency (defined by time to task completion), distance covered inside the nose, average velocity towards target, accuracy (measured by error rate), and subjective assessment of endoscope characteristics. Results: During ESS tasks, both efficiency and accuracy did not differ significantly between 2D HD and 3D HD endoscopy. Subjectively, imaging characteristics of the 3D HD endoscope were rated significantly better. Conclusions: ESS performance of inexperienced participants was not significantly improved by the use of 3D HD endoscopy during ESS tasks, although imaging characteristics of the 3D HD endoscope were rated significantly better. Surgical field characteristics and surgical techniques are likely to influence any additional value of 3D HD endoscopy

Biological tumor markers associated with local control after primary radiotherapy in laryngeal cancer:A systematic review

Background The choice of treatment in laryngeal cancer is mainly based on tumor stage, post-treatment morbidity and quality of life. Biological tumor markers might also be of potential clinical relevance. Objective of the review The aim was to systematically review the value of published biological tumor markers to predict local control in laryngeal cancer patients treated with definitive radiotherapy. Type of Review Systematic review. Search strategy PubMed, Embase, Cochrane Library. Evaluation Method A literature search was performed using multiple terms for laryngeal cancer, radiotherapy, biological markers, detection methods and local control or survival. Studies regarding the relation between biological tumor markers and local control or survival in laryngeal cancer patients primarily treated with radiotherapy were included. Markers were clustered on biological function. Quality of all studies was assessed. Study selection, data extraction and quality assessment was performed by two independent reviewers. Results A total of 52 studies out of 618 manuscripts, concerning 118 markers, were included. EGFR and P53 showed consistent evidence for not being predictive of local control after primary radiotherapy, whereas proliferation markers (ie high Ki-67 expression) showed some, but no consistent, evidence for being predictive of better local control. Other clusters of markers (markers involved in angiogenesis and hypoxia, apoptosis markers, cell cycle, COX-2 and DNA characteristics) showed no consistent evidence towards being predictors of local control after primary radiotherapy. Conclusions Cell proliferation could be of potential interest for predicting local control after primary radiotherapy in laryngeal cancer patients, whereas EGFR and p53 are not predictive in contrast to some previous analyses. Large diversity in research methods is found between studies, which results in contradictory outcomes. Future studies need to be more standardised and well described according to the REMARK criteria in order to have better insight into which biomarkers can be used as predictors of local control after primary radiotherapy

Ice chemistry in massive Young Stellar Objects: the role of metallicity

We present the comparison of the three most important ice constituents (water, CO and CO2) in the envelopes of massive Young Stellar Objects (YSOs), in environments of different metallicities: the Galaxy, the Large Magellanic Cloud (LMC) and, for the first time, the Small Magellanic Cloud (SMC). We present observations of water, CO and CO2 ice in 4 SMC and 3 LMC YSOs (obtained with Spitzer-IRS and VLT/ISAAC). While water and CO2 ice are detected in all Magellanic YSOs, CO ice is not detected in the SMC objects. Both CO and CO2 ice abundances are enhanced in the LMC when compared to high-luminosity Galactic YSOs. Based on the fact that both species appear to be enhanced in a consistent way, this effect is unlikely to be the result of enhanced CO2 production in hotter YSO envelopes as previously thought. Instead we propose that this results from a reduced water column density in the envelopes of LMC YSOs, a direct consequence of both the stronger UV radiation field and the reduced dust-to-gas ratio at lower metallicity. In the SMC the environmental conditions are harsher, and we observe a reduction in CO2 column density. Furthermore, the low gas-phase CO density and higher dust temperature in YSO envelopes in the SMC seem to inhibit CO freeze-out. The scenario we propose can be tested with further observations.Comment: accepted by MNRAS Letters; 5 pages, 3 figures, 1 tabl