A note on the Hybrid Soil Moisture Deficit Model v2.0

peer-reviewedThe Hybrid Soil Moisture Deficit (HSMD) model has been used for a wide range of applications, including modelling of grassland productivity and utilisation, assessment of agricultural management opportunities such as slurry spreading, predicting nutrient emissions to the environment and risks of pathogen transfer to water. In the decade since its publication, various ad hoc modifications have been developed and the recent publication of the Irish Soil Information System has facilitated improved assessment of the spatial soil moisture dynamics. In this short note, we formally present a new version of the model (HSMD2.0), which includes two new soil drainage classes, as well as an optional module to account for the topographic wetness index at any location. In addition, we present a new Indicative Soil Drainage Map for Ireland, based on the Irish Soil Classification system, developed as part of the Irish Soil Information System

SIW cavity-backed slot (multi-)antenna systems for the next generation IoT applications

Substrate integrated waveguide (SIW) cavity-backed slot antenna topologies are promising candidates to adress the specific design challenges posed by the Internet of Things (IoT). In this contribution, we demonstrate their potential by discussing two designs on two different, application-specific, innovative substrate materials. First, a compact, ultra-wideband three-element array with very low mutual coupling is presented for integration into furniture. In the second design, the half-mode SIW technique is applied to obtain a miniaturized ultra-wideband design, enabling invisible integration into cork floor and wall tiles. The compactness, integrability, and stable, high performance of both designs in different operating conditions, make them ideal candidates for IoT applications

Agriculture, meteorology and water quality in Ireland: a regional evaluation of pressures and pathways of nutrient loss to water

peer-reviewedThe main environmental impact of Irish agriculture on surface and ground water quality is the potential transfer of nutrients to water. Soil water dynamics mediate the transport of nutrients to water, and these dynamics in turn depend on agro-meteorological conditions, which show large variations between regions, seasons and years. In this paper we quantify and map the spatio-temporal variability of agro-meteorological factors that control nutrient pressures and pathways of nutrient loss. Subsequently, we evaluate their impact on the water quality of Irish rivers. For nitrogen, pressure and pathways factors coincide in eastern and southern areas, which is reflected in higher nitrate levels of the rivers in these regions. For phosphorus, pathway factors are most pronounced in north-western parts of the country. In south-eastern parts, high pressure factors result in reduced biological water quality. These regional differences require that farm practices be customised to reflect the local risk of nutrient loss to water. Where pathways for phosphorus loss are present almost year-round—as is the case in most of the north-western part of the country—build-up of pressures should be prevented, or ameliorated where already high. In south-eastern areas, spatio-temporal coincidence of nutrient pressures and pathways should be prevented, which poses challenges to grassland management

The Nearby and Extremely Metal-Poor Galaxy CGCG 269-049

We present Hubble Space Telescope (HST) and Spitzer Space Telescope images and photometry of the extremely metal-poor (Z = 0.03 Z_sol) blue dwarf galaxy CGCG 269-049. The HST images reveal a large population of red giant and asymptotic giant branch stars, ruling out the possibility that the galaxy has recently formed. From the magnitude of the tip of the red giant branch, we measure a distance to CGCG 269-049 of only 4.9 +/- 0.4 Mpc. The spectral energy distribution of the galaxy between ~3.6 - 70 microns is also best fitted by emission from predominantly ~10 Gyr old stars, with a component of thermal dust emission having a temperature of 52 +/- 10 K. The HST and Spitzer photometry indicate that more than 60% of CGCG 269-049's stellar mass consists of stars ~10 Gyr old, similar to other local blue dwarf galaxies. Our HST H-alpha image shows no evidence of a supernova-driven outflow that could be removing metals from the galaxy, nor do we find evidence that such outflows occurred in the past. Taken together with CGCG 269-049's large ratio of neutral hydrogen mass to stellar mass (~10), these results are consistent with recent simulations in which the metal deficiency of local dwarf galaxies results mainly from inefficient star formation, rather than youth or the escape of supernova ejecta.Comment: 35 Pages, 7 Figures, accepted for publication in ApJ; new version corrects errors in Table 1, Figure 3, and related calculations in tex

Enteral Vancomycin to Eliminate MRSA Carriership of the Digestive Tract in Critically Ill Patients

Background: Carriership with methicillin resistant Staphylococcus aureus (MRSA) is a risk for the development of secondary infections in critically ill patients. Previous studies suggest that enteral vancomycin is able to eliminate enteral carriership with MRSA. Data on individual effects of this treatment are lacking. Methods: Retrospective analysis of a database containing 15 year data of consecutive patients from a mixed medical-(cardio)surgical 18 bedded intensive care unit was conducted. All consecutive critically ill patients with enteral MRSA carriership detected in throat and/or rectal samples were collected. We analyzed those with follow-up cultures to determine the success rate of enteral vancomycin. Topical application of 2% vancomycin in a sticky oral paste was performed combined with a vancomycin solution of 500 mg four times daily in the nasogastric tube. This treatment was added to a regimen of selective digestive tract decontamination (SDD) to prevent ICU acquired infection. Results: Thirteen patients were included. The mean age was 65 years and the median APACHE II score was 21. MRSA was present in the throat in 8 patients and in both throat and rectum in 5 patients. In all patients MRSA was successfully eliminated from both throat and rectum, which took 2–11 days with a median duration until decontamination of 4 days. Secondary infections with MRSA did not occur. Conclusions: Topical treatment with vancomycin in a 2% sticky oral paste four times daily in the nasogastric tube was effective in all patients in the elimination of MRSA and prevented secondary MRSA infections

Simple model for the power-law blinking of single semiconductor nanocrystals

We assign the blinking of nanocrystals to electron tunneling towards a uniform spatial distribution of traps. This naturally explains the power-law distribution of off times, and the power-law correlation function we measured on uncapped CdS dots. Capped dots, on the other hand, present extended on times leading to a radically different correlation function. This is readily described in our model by involving two different, dark and bright, charged states. Coulomb blockade prevents further ionization of the charged dot, thus giving rise to long, power-law distributed off and on times

Compact Lyman-alpha Emitting Candidates at z~2.4 in Deep Medium-band HST WFPC2 Images

Medium-band imaging with HST/WFPC2 in the F410M filter has previously revealed a population of compact Lyman-alpha emission objects around the radio galaxy 53W002 at z~2.4. We report detections of similar objects at z~2.4 in random, high-latitude HST parallel observations of three additional fields, lending support to the idea that they constitute a widespread population at these redshifts. The three new fields contain 18 Lyman-alpha candidates, in contrast to the 17 detected in the deeper exposure of the single WFPC2 field around 53W002. We find substantial differences in the number of candidates from field to field, suggesting that significant large-scale structure is already present in the galaxy distribution at this cosmic epoch. The likely existence of z~2.4 sub-galactic clumps in several random fields shows that these objects may have been common in the early universe and strengthens the argument that such objects may be responsible for the formation of a fraction of the luminous present-day galaxies through hierarchical merging.Comment: Uses slightly modified AASTeX preprint style file (included). Contains 22 pages, including 5 figures and 2 tables. Accepted for the December issue of the Astronomical Journa

The Kuiper Belt and Olbers Paradox

We investigate the constraints that Olbers Paradox, applied to the Zodiacal Background as measured from space, sets on outer solar system objects. If extended to very faint limits, R = 40--50 mag, the steep optical luminosity function (LF) of Kuiper Belt objects (KBOs) at R less than 26 mag implies an infinitely bright night sky. Small KBOs with radii of 1 mm to 1 km must have a size distribution n(r) proportional to r^{-a}, with a = 3.5 or smaller to satisfy the known limits on the sky-surface brightness at optical and far-infrared wavelengths. Improved limits on the measured KBO surface brightness can yield direct estimates of the albedo, temperature, and size distribution for small KBOs in the outer solar system.Comment: 4 pages and 2 figures; submitted to Astrophysical Journal Letter