Magnetic Field Structure around Low-Mass Class 0 Protostars: B335, L1527 and IC348-SMM2

We report new 350 micron polarization observations of the thermal dust emission from the cores surrounding the low-mass, Class 0 YSOs L1527, IC348-SMM2 and B335. We have inferred magnetic field directions from these observations, and have used them together with results in the literature to determine whether magnetically regulated core-collapse and star-formation models are consistent with the observations. These models predict a pseudo-disk with its symmetry axis aligned with the core magnetic field. The models also predict a magnetic field pinch structure on a scale less than or comparable to the infall radii for these sources. In addition, if the core magnetic field aligns (or nearly aligns) the core rotation axis with the magnetic field before core collapse, then the models predict the alignment (or near alignment) of the overall pinch field structure with the bipolar outflows in these sources. We show that if one includes the distorting effects of bipolar outflows on magnetic fields, then in general the observational results for L1527 and IC348-SMM2 are consistent with these magnetically regulated models. We can say the same for B335 only if we assume the distorting effects of the bipolar outflow on the magnetic fields within the B335 core are much greater than for L1527 and IC348-SMM2. We show that the energy densities of the outflows in all three sources are large enough to distort the magnetic fields predicted by magnetically regulated models.Comment: Accepted for publication in The Astrophysical Journa

Localization and its consequences for quantum walk algorithms and quantum communication

The exponential speed-up of quantum walks on certain graphs, relative to classical particles diffusing on the same graph, is a striking observation. It has suggested the possibility of new fast quantum algorithms. We point out here that quantum mechanics can also lead, through the phenomenon of localization, to exponential suppression of motion on these graphs (even in the absence of decoherence). In fact, for physical embodiments of graphs, this will be the generic behaviour. It also has implications for proposals for using spin networks, including spin chains, as quantum communication channels.Comment: 4 pages, 1 eps figure. Updated references and cosmetic changes for v

Supplmentary Feeding and Management Strategies to Overcome Drought Situations on Three High Producing New Zealand Seasonal Dairy Farms

This paper investigates the outcomes of the management strategies to overcome dry summer conditions on three New Zealand seasonal supply dairy farms where the summer management philosophy is towards production rather than survival aimed at giving the farmer control rather than accepting the unreliable production outcomes often achieved. Actual data collected from the case farms as part of a large on-farm monitoring programme was used to model the dry 1998/99 season. This was compared with simulated models for an average season to estimate milksolids responses (g milksolids (MS)/kg DM) and net returns (cents/kg DM) to the additional feeds used. In response to a 30% reduction in summer pasture growth, farmers fed more additional feeds (542 kg DM/ha) and achieved fewer lactation days/ha resulting a reduction of 12.5% in per cow and 19.8% in per hectare milksolids production. The average response achieved to the addition feed was 104g MS/kg DM at a net return of 20.6cents/kg DM fed above the cost of additional feed. It was concluded that the management strategies achieved the target of having cows in good condition and at a satisfactory level of production at the end of summer to enable autumn milk production to be captured and that farmers should look at further increasing the level of supplement fed in dry summer conditions

Feeding of Conserved Forage - Implications to Grassland Management and Production

This review will focus on the use of conserved forages in pastoral dairy farm systems; especially on their conservation as an aid to good grazing management during periods of rapid pasture growth, and on their consumption as an aid to good feeding management and grazing management during periods of slow pasture growth. Conservation of pasture, in order to move it from one time to another later time, always involves “costs”, either financial expenditure or physical losses (of dry matter/quality) or both, which must be evaluated in the whole system. Most of the data is drawn from New Zealand and Australia, with some from England and Ireland. The topic has been reviewed before (e.g. Rogers, 1984 and 1985; Leaver, 1985; Phillips, 1988; Mayne, 1991; Stockdale et al., 1997), but the present review will put greater emphasis on the effects on pasture management and on the whole pastoral system, and on recent results, because the cows’ ability to respond to supplementary feeds is now larger than it used to be, as a result of steady genetic improvement in milk producing capacities. In recent years there has been marked increase in supplement use on pasture based dairy farming systems in New Zealand often driven by perceived limitations to production increases in existing systems rather than profit (Attrill and Miller 1996). This review attempts to identify, and discuss, the factors involved in supplementary feeding (i.e. the responses of cows and farming systems to extra feed) to enable sustainable increases in productivity and profitability on pastoral based systems

"It is Quietly Chaotic. It Confuses Time"*: Final Report of Excavations at the Bordley-Randall Site in Annapolis, Maryland, 1993-1995 (18AP50)

*This extract is from Gay P. Crowther's description of the Randall Court pathway (Cowther 1985).Part of the State Circle Site: http://hdl.handle.net/1903/11004During the summers of 1993, 1994, and 1995, the Archaeology in Annapolis project conducted excavations at the Bordley-Randall site (1 8AP50) in Annapolis, Maryland. The site now consists of the central portion of the block formed by North Street, College Avenue, Prince George Street, Maryland Avenue, and State Circle. The excavations were undertaken as part of the University of Maryland, College Park's Field School in Urban Archaeology and were organized to be support for dissertation research being done by Christopher Matthews of Columbia University. This report provides a background, summary, and interpretation of these archaeological investigations of the Bordley-Randall site. The site was tested in five areas: the Front Yard, the Back Yard, the West Wing Yard, the East Wing Yard, and the interior of the East Wing. The excavations revealed significant deposits from several different periods of occupation. These deposits show the progression of the site from the early Settlement Period in Annapolis through the Modem Period (as defined in Weissman 1986). In many areas of the site the excavations discovered deposits dating to the early 1700s when the site was first occupied and built on by Thomas Bordley. These deposits also helped to date the house and the East Wing to before 1748. Later alterations to the site, dating to the third quarter of the 18th century, were associated with the construction of and use of a terrace around the East Wing. The landscape of the front and rear yards were discovered to have been altered in the mid-19th century by the laying in of an extensive kitchen garden in the rear yard and the building of a park-like garden in the front. These alterations were predominantly defined by fill soils and the definition of garden paths. Later alterations made the city block fully modern as the street front lots were sold off and built over with businesses on Maryland Avenue and residences on the other streets beginning in the 1870s. In the interior, around 1895, an oval-shaped path was built in the front yard to which many of the new residences faced forming an enclosed, semi-private, semi-public space, now known as Randall Court. This space has remained essentially in tact since the early years of the 20th century. The appendices to this report include a transcription of several key historic documents related to the site, the report to the Maryland Humanities Council for funding in support of a public program at the site in 1995, the level and feature reports, and the staff qualifications. The attached diskette has a zipped file of the Bordley-Randall site artifact database

Influence of Anthropometric Variables on Three Different Maximal Oxygen Consumption Units: NHANES 2003-2004

Please see the pdf version of the abstract

Bifurcation scenario to Nikolaevskii turbulence in small systems

We show that the chaos in Kuramoto-Sivashinsky equation occurs through period-doubling cascade (Feigenbaum scenario), in contrast, the chaos in Nikolaevskii equation occurs through torus-doubling bifurcation (Ruelle-Takens-Newhouse scenario).Comment: 8pages, 9figure

The Effects of Post-Grazing Sward Conditions on Herbage Accumulation in Winter and Spring

Two on-farm experiments were conducted in the winter and spring of 1998 on a New Zealand seasonal production dairy farm to determine the effect of herbage mass present after grazing on subsequent pasture growth rates. Experiments involved a range of post-grazing levels of herbage mass (870, 1140, 1390, 1640, 1920 kg DM/ha in winter, and 1100, 1420, 1700 and 1910 kg DM/ha in spring) representing a range in cow intakes of 6.1-20.0 and 7.6-18.5 kg DM/cow/day in winter and spring, respectively. In both experiments there was a range of postgrazing herbage mass (1200-1600 kg DM/ha in winter and 1400-1800 kg DM/ha in spring) over which post-grazing residuals had little effect on pasture growth rates. This lack of response was explained by underlying changes in sward components. Grazing residuals of 1200-1300 and 1500-1600 kg DM/ha were recommended to provide an adequate compromise between the pasture and animal requirements of grazing management considered important in winter and spring respectively. This study adds to the growing evidence to support farming systems focused on sward targets in enhancing both pasture and animal performance

Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

CONTEXT: In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. OBJECTIVES: To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. METHODS: Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. RESULTS: The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. CONCLUSIONS: This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions