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The Potential of Freeform Construction Processes
The level of automation technology and processes control found in modern day construction
lags significantly behind other industries such as automotive and aerospace. The construction
industry has health and safety issues and still uses traditional methods of procurement. These
problems are compounded by diminishing skills in the labour force. Methods of production
must change if these issues are to be resolved and Freeform Construction is a collection of
processes that could have potential impact. This paper outlines some of the major issues
facing construction and sets a context with examples of digital fabrication in construction.
Freeform Construction is defined and potential applications are presented and related to
application scale. The viability of two potential applications are investigated in terms of cost.Mechanical Engineerin
Warm HCN, C2H2, and CO in the disk of GV Tau
We present the first high-resolution, ground-based observations of HCN and
C2H2 toward the T Tauri binary star system GV Tau. We detected strong
absorption due to HCN nu_3 and weak C2H2 (nu_3 and nu_2 + (nu_4 + nu_5)^0_+)
absorption toward the primary (GV Tau S) but not the infrared companion. We
also report CO column densities and rotational temperatures, and present
abundances relative to CO of HCN/CO ~0.6% and C2H2/CO ~1.2% and an upper limit
for CH4/CO < 0.37% toward GV Tau S. Neither HCN nor C2H2 were detected toward
the infrared companion and results suggest that abundances may differ between
the two sources.Comment: 23 pages, 6 figures, accepted by Ap
Survival of HIV-1 vertically infected children
PURPOSE OF REVIEW: It is 20 years since the start of the combination antiretroviral therapy (cART) era and more than 10 years since cART scale-up began in resource-limited settings. We examined survival of vertically HIV-infected infants and children in the cART era. RECENT FINDINGS: Good survival has been achieved on cART in all settings with up to 10-fold mortality reductions compared with before cART availability. Although mortality risk remains high in the first few months after cART initiation in young children with severe disease, it drops rapidly thereafter even for those who started with advanced disease, and longer term mortality risk is low. However, suboptimal retention on cART in routine programs threatens good survival outcomes and even on treatment children continue to experience high comorbidity risk; infections remain the major cause of death. Interventions to address infection risk include a cotrimoxazole prophylaxis, isoniazid preventive therapy, routine childhood and influenza immunization, and improving maternal survival. SUMMARY: Pediatric survival has improved substantially with cART and HIV-infected children are aging into adulthood. It is important to ensure access to diagnosis and early cART, good program retention as well as optimal comorbidity prophylaxis and treatment to achieve the best possible long-term survival and health outcomes for vertically infected children
A Proper Motion Study of the Haro 6-10 Outflow: Evidence for a Subarcsecond Binary
We present single-dish and VLBI observations of an outburst of water maser
emission from the young binary system Haro 6-10. Haro 6-10 lies in the Taurus
molecular cloud and contains a visible T Tauri star with an infrared companion
1.3" north. Using the Very Long Baseline Array, we obtained five observations
spanning 3 months and derived absolute positions for 20 distinct maser spots.
Three of the masers can be traced over 3 or more epochs, enabling us to extract
absolute proper motions and tangential velocities. We deduce that the masers
represent one side of a bipolar outflow that lies nearly in the plane of the
sky with an opening angle of ~45\deg. They are located within 50 mas of the
southern component of the binary, the visible T Tauri star Haro 6-10S. The mean
position angle on the sky of the maser proper motions (~220\deg) suggests they
are related to the previously observed giant Herbig-Haro (HH) flow which
includes HH410, HH411, HH412, and HH184A-E. A previously observed HH jet and
extended radio continuum emission (mean position angle of ~190\deg) must also
originate in the vicinity of Haro6-10S and represent a second, distinct outflow
in this region. We propose that a yet unobserved companion within 150 mas of
Haro6-10S is responsible for the giant HH/maser outflow while the visible star
is associated with the HH jet. Despite the presence of H_2 emission in the
spectrum of the northern component of the binary, Haro6-10N, none of
outflows/jets can be tied directly to this young stellar object
Law Libraries and Laboratories: The Legacies of Langdell and His Metaphor
Law Librarians and others have often referred to Harvard Law School Dean C.C. Langdell’s statements that the law library is the lawyer’s laboratory. Professor Danner examines the context of what Langdell through his other writings, the educational environment at Harvard in the late nineteenth century, and the changing perceptions of university libraries generally. He then considers how the “laboratory metaphor” has been applied by librarians and legal scholars during the twentieth century and into the twenty-first. The article closes with thoughts on Langdell’s legacy for law librarians and the usefulness of the laboratory metaphor
Uniaxial magnetocrystalline anisotropy in
is a paramagnetic metal and since its low temperature
resistivity is described by with , it
is also considered a non-Fermi liquid (NFL) metal. We have performed extensive
magnetoresistance and Hall effect measurements of untwinned epitaxial films of
. These measurements reveal that exhibits
uniaxial magnetocrystalline anisotropy. In addition, the low-temperature NFL
behavior is most effectively suppressed when a magnetic field is applied along
the easy axis, suggesting that critical spin fluctuations, possibly due to
proximity of a quantum critical phase transition, are related to the NFL
behavior.Comment: 7 figure
Programming Protocol-Independent Packet Processors
P4 is a high-level language for programming protocol-independent packet
processors. P4 works in conjunction with SDN control protocols like OpenFlow.
In its current form, OpenFlow explicitly specifies protocol headers on which it
operates. This set has grown from 12 to 41 fields in a few years, increasing
the complexity of the specification while still not providing the flexibility
to add new headers. In this paper we propose P4 as a strawman proposal for how
OpenFlow should evolve in the future. We have three goals: (1)
Reconfigurability in the field: Programmers should be able to change the way
switches process packets once they are deployed. (2) Protocol independence:
Switches should not be tied to any specific network protocols. (3) Target
independence: Programmers should be able to describe packet-processing
functionality independently of the specifics of the underlying hardware. As an
example, we describe how to use P4 to configure a switch to add a new
hierarchical label
Geophysical characteristics and crustal structure of greenstone terranes: Canadian Shield
Geophysical studies in the Canadian Shield have provided some insights into the tectonic setting of greenstone belts. Greenstone belts are not rooted in deep crustal structures. Geophysical techniques consistently indicate that greenstones are restricted to the uppermost 10 km or so of crust and are underlain by geophysically normal crust. Gravity models suggest that granitic elements are similarly restricted, although magnetic modelling suggests possible downward extension to the intermediate discontinuity around approx. 18 km. Seismic evidence demonstrates that steeply-dipping structure, which can be associated with the belts in the upper crust, is not present in the lower crust. Horizontal intermediate discontinuities mapped under adjacent greenstone and granitic components are not noticeably disrupted in the boundary zone. Geophysical evidence points to the presence of discontinuities between greenhouse-granite and adjacent metasedimentary erranes. Measured stratigraphic thicknesses of greenstone belts are often twice or more the vertical thicknesses determined from gravity modelling. Explantations advanced for the discrepancy include stratigraphy repeated by thrust faulting and/or listric normal faulting, mechanisms which are consistent with certain aspects of conceptual models of greenstone development. Where repetition is not a factor the gravity evidence points to removal of the root zones of greenstone belts. For one region, this has been attributed to magmatic stopping during resurgent caldera activity
Prevalence of liver fluke (Fasciola hepatica) in wild Red Deer (Cervus elaphus): coproantigen ELISA is a practicable alternative to faecal egg counting for surveillance in remote populations
Red deer (Cervus elaphus) are hosts of liver fluke (Fasciola hepatica); yet, prevalence is rarely quantified in wild populations. Testing fresh samples from remote regions by faecal examination (FE) can be logistically challenging; hence, we appraise frozen storage and the use of a coproantigen ELISA (cELISA) for F. hepatica surveillance. We also present cELISA surveillance data for red deer from the Highlands of Scotland. Diagnoses in faecal samples (207 frozen, 146 fresh) were compared using a cELISA and by FE. For each storage method (frozen or fresh), agreement between the two diagnostics was estimated at individual and population levels, where population prevalence was stratified into cohorts (e.g., by sampling location). To approximate sensitivity and specificity, 65 post-slaughter whole liver examinations were used as a reference. At the individual level, FE and cELISA diagnoses agreed moderately (κfrozen = 0.46; κfresh = 0.51), a likely reflection of their underlying principles. At the population level, FE and cELISA cohort prevalence correlated strongly (Pearson’s R = 0.89, p < 0.0001), reflecting good agreement on relative differences between cohort prevalence. In frozen samples, prevalence by cELISA exceeded FE overall (42.8% vs. 25.8%) and in 9/12 cohorts, alluding to differences in sensitivity; though, in fresh samples, no significant difference was found. In 959 deer tested by cELISA across the Scottish Highlands, infection prevalence ranged from 9.6% to 53% by sampling location. We highlight two key advantages of cELISA over FE: i) the ability to store samples long term (frozen) without apparent loss in diagnostic power; and ii) reduced labour and the ability to process large batches. Further evaluation of cELISA sensitivity in red deer, where a range of fluke burdens can be obtained, is desirable. In the interim, the cELISA is a practicable diagnostic for F. hepatica surveillance in red deer, and its application here has revealed considerable geographic, temporal, sex and age related differences in F. hepatica prevalence in wild Scottish Highland red deer
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