Home advantage? Decomposition across the freshwater-estuarine transition zone varies with litter origin and local salinity

Expected increases in the frequency and intensity of storm surges and river flooding may greatly affect the relative salinity of estuarine environments over the coming decades. In this experiment we used detritus from three contrasting environments (marine Fucus vesiculosus; estuarine Spartina anglica; terrestrial Quercus robur) to test the prediction that the decomposition of the different types of litter would be highest in the environment with which they are associated. Patterns of decomposition broadly fitted our prediction: Quercus detritus decomposed more rapidly in freshwater compared with saline conditions while Fucus showed the opposite trend; Spartina showed an intermediate response. Variation in macro-invertebrate assemblages was detected along the salinity gradient but with different patterns between estuaries, suggesting that breakdown rates may be linked in part to local invertebrate assemblages. Nonetheless, our results suggest that perturbation of salinity gradients through climate change could affect the process of litter decomposition and thus alter nutrient cycling in estuarine transition zones. Understanding the vulnerability of estuaries to changes in local abiotic conditions is important given the need to better integrate coastal proceses into a wider management framework at a time when coastlines are increasingly threatened by human activities

Aortic Pathology Determines Midterm Outcome After Endovascular Repair of the Thoracic Aorta Report From the Medtronic Thoracic Endovascular Registry (MOTHER) Database

Background—Endovascular repair of the thoracic aorta has become an increasingly utilized therapy. Although the short-term mortality advantage over open surgery is well documented, late mortality and the impact of presenting pathology on long-term outcomes remain poorly reported. Methods and Results—A database was built from 5 prospective studies and a single institutional series. Rates of perioperative adverse events were calculated, as were midterm death and reintervention rates. Multivariate analysis was performed with the use of logistic regression modeling. Kaplan-Meier survival curves were drawn for midterm outcomes. The database contained 1010 patients: 670 patients with thoracic aortic aneurysm, 195 with chronic type B aortic dissection, and 114 with acute type B aortic dissection. Lower elective mortality was observed in patients with chronic dissections (3%) compared with patients with aneurysms (5%). Multivariate analysis identified age, mode of admission, American Society of Anesthesiologists grade, and pathology as independent predictors of 30-day death (P < 0.05). In the midterm, the all-cause mortality rate was 8, 4.9, and 3.2 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. The rates of aortic-related death were 0.6, 1.2, and 0.4 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. Conclusions—This study indicated that the midterm outcomes of endovascular repair of the thoracic aorta are defined by presenting pathology, associated comorbidities, and mode of admission. Nonaortic mortality is high in the midterm for patients with thoracic aortic aneurysm, and managing modifiable risk factors appears vital. Endovascular repair of the thoracic aorta results in excellent midterm protection from aortic-related mortality, regardless of presenting pathology

Occurrence and assemblage composition of intertidal non-native species may be influenced by shipping patterns and artificial structures

Habitat modification coupled with the spread of non-native species (NNS) are among the top threats to marine biodiversity globally. Species are known to be transported to new locations via international shipping and secondarily spread via regional vessels and artificial structures. Rapid Assessment Surveys (RAS) combining quantitative and semi-quantitative methods compared NNS richness and assemblage composition on intertidal natural rocky shores and artificial structures in harbours in different regions along the south coast of England. Quantitative data showed that artificial habitats supported higher richness than natural habitats, while semi-quantitative data found no difference in richness among habitat types. This result was attributed to additional species found in rock pools during searches of complex microhabitats in natural habitats. Assemblages on artificial structures differed among regions, with regions and harbours with greater numbers of vessels supporting greater richness. Results highlight the importance of shipping and artificial structures for NNS introduction and spread

Generalised Apery numbers modulo 9

Whilst locoregional control of head and neck cancers (HNCs) has improved over the last four decades, long-term survival has remained largely unchanged. A possible reason for this is that the rate of distant metastasis has not changed. Such disseminated disease is reflected in measurable levels of cancer cells in the blood of HNC patients, referred to as circulating tumour cells (CTCs). Numerous marker-independent techniques have been developed for CTC isolation and detection. Recently, microfluidics-based platforms have come to the fore to avoid molecular bias. In this pilot, proof of concept study, we evaluated the use of the spiral microfluidic chip for CTC enrichment and subsequent detection in HNC patients. CTCs were detected in 13/24 (54%) HNC patients, representing both early to late stages of disease. Importantly, in 7/13 CTC-positive patients, CTC clusters were observed. This is the first study to use spiral microfluidics technology for CTC enrichment in HNC

Vibronic Structure in Room Temperature Photoluminescence of the Halide Perovskite Cs3Bi2Br9

We report a study on the optical properties of the layered polymorph of vacancy-ordered triple perovskite Cs3Bi2Br9. The electronic structure, determined from density functional theory calculations, shows the top of the valence band and bottom of the conduction band minima are, unusually, dominated by Bi s and p states, respectively. This produces a sharp exciton peak in the absorption spectra with a binding energy that was approximated to be 940 meV, which is substantially stronger than values found in other halide perovskites and, instead, more closely reflects values seen in alkali halide crystals. This large binding energy is indicative of a strongly localized character and results in a highly structured emission at room temperature as the exciton couples to vibrations in the lattice

Activated Magnetospheres of Magnetars

Like the solar corona, the external magnetic field of magnetars is twisted by surface motions of the star. The twist energy is dissipated over time. We discuss the theory of this activity and its observational status. (1) Theory predicts that the magnetosphere tends to untwist in a peculiar way: a bundle of electric currents (the "j-bundle") is formed with a sharp boundary, which shrinks toward the magnetic dipole axis. Recent observations of shrinking hot spots on magnetars are consistent with this behavior. (2) Continual discharge fills the j-bundle with electron-positron plasma, maintaining a nonthermal corona around the neutron star. The corona outside a few stellar radii strongly interacts with the stellar radiation and forms a "radiatively locked" outflow with a high e+- multiplicity. The locked plasma annihilates near the apexes of the closed magnetic field lines. (3) New radiative-transfer simulations suggest a simple mechanism that shapes the observed X-ray spectrum from 0.1 keV to 1 MeV: part of the thermal X-rays emitted by the neutron star are reflected from the outer corona and then upscattered by the inner relativistic outflow in the j-bundle, producing a beam of hard X-rays.Comment: 23 pages, 7 figures; review chapter in the proceedings of ICREA Workshop on the High-Energy Emission from Pulsars and Their Systems, Sant Cugat, Spain, April 201

Short term ex-vivo expansion of circulating head and neck tumour cells.

Minimally invasive techniques are required for the identification of head and neck cancer (HNC) patients who are at an increased risk of metastasis, or are not responding to therapy. An approach utilised in other solid cancers is the identification and enumeration of circulating tumour cells (CTCs) in the peripheral blood of patients. Low numbers of CTCs has been a limiting factor in the HNC field to date. Here we present a methodology to expand HNC patient derived CTCs ex-vivo. As a proof of principle study, 25 advanced stage HNC patient bloods were enriched for circulating tumour cells through negative selection and cultured in 2D and 3D culture environments under hypoxic conditions (2% O2, 5% CO2). CTCs were detected in 14/25 (56%) of patients (ranging from 1-15 CTCs/5 mL blood). Short term CTC cultures were successfully generated in 7/25 advanced stage HNC patients (5/7 of these cultures were from HPV+ patients). Blood samples from which CTC culture was successful had higher CTC counts (p = 0.0002), and were predominantly from HPV+ patients (p = 0.007). This is, to our knowledge, the first pilot study to culture HNC CTCs ex-vivo. Further studies are warranted to determine the use of short term expansion in HNC and the role of HPV in promoting culture success

Pleosporales

One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae

Chemotaxis When Bacteria Remember: Drift versus Diffusion

{\sl Escherichia coli} ({\sl E. coli}) bacteria govern their trajectories by switching between running and tumbling modes as a function of the nutrient concentration they experienced in the past. At short time one observes a drift of the bacterial population, while at long time one observes accumulation in high-nutrient regions. Recent work has viewed chemotaxis as a compromise between drift toward favorable regions and accumulation in favorable regions. A number of earlier studies assume that a bacterium resets its memory at tumbles -- a fact not borne out by experiment -- and make use of approximate coarse-grained descriptions. Here, we revisit the problem of chemotaxis without resorting to any memory resets. We find that when bacteria respond to the environment in a non-adaptive manner, chemotaxis is generally dominated by diffusion, whereas when bacteria respond in an adaptive manner, chemotaxis is dominated by a bias in the motion. In the adaptive case, favorable drift occurs together with favorable accumulation. We derive our results from detailed simulations and a variety of analytical arguments. In particular, we introduce a new coarse-grained description of chemotaxis as biased diffusion, and we discuss the way it departs from older coarse-grained descriptions.Comment: Revised version, journal reference adde