2,881 research outputs found
CASPaR: Congestion Avoidance Shortest Path Routing for Delay Tolerant Networks
Unlike traditional TCP/IP-based networks, Delay and Disruption Tolerant Networks (DTNs) may experience connectivity disruptions and guarantee no end-to-end connectivity between source and destination. As the popularity of DTNs continues to rise, so does the need for a robust and low latency routing protocol capable of connecting not only DTNs but also densely populated, dynamic hybrid DTN-MANET. Here we describe a novel DTN routing algorithm referred to as Congestion Avoidance Shortest Path Routing (CASPaR), which seeks to maximize packet delivery probability while minimizing latency. CASPaR attempts this without any direct knowledge of node connectivity outside of its own neighborhood. Our simulation results show that CASPaR outperforms well-known protocols in terms of packet delivery probability and latency while limiting network overhead
Stock assessment of the Australian east coast tailor (Pomatomus saltatrix) fishery
Tailor is a highly migratory fish with an iconic, mainly beach-based fishery on the Australian east coast. There is a pronounced annual, close-inshore run of large schools of tailor from New South Wales, where the fishery peaks in April–June, to Queensland where the Fraser Island fishery at the northern end of the run peaks in August–September. The commercial sector of the fishery developed over the first half of the 20th century while the recreational beach line sector grew strongly from the late 1940s, facilitated by rapid developments in recreational beach-fishing gear.
The recreational sector appeared to have had a pronounced peak in both harvest size and fishing effort in the mid-1990s, after which both the recreational and commercial sectors experienced big falls driven largely by cultural change. Recreational participation rates and fishing effort fell sharply while fishery management implemented measures such as bag limits on the recreational sector and harvest limits and spatial restrictions on the commercial sector.
Information on the tailor fishery is relatively rich in fish length-frequency and ageing data, although data quality greatly improved from the mid-1990s with the introduction of scientific sampling methods. Prior to that time there were no reliable fish ageing data and most length-frequency data came from tagging experiments. The eastern Australian stock of tailor mainly consists of young fish with not many surviving beyond four years of age. The oldest fish aged by Fisheries Queensland’s monitoring team were just under seven years of age
Evolution of endogenous retroviruses in the Suidae: evidence for different viral subpopulations in African and Eurasian host species
Glucocorticoid- and progesterone-specific effects are determined by differential expression of the respective hormone receptors
Collaborative Management of HIV Infection in the Community: An Effort to Improve the Quality of HIV Care
Our hospital led a multidisciplinary community team to improve the quality of care delivered to HIV-infected clients utilizing a disease management approach in a US metropolitan community of 150,000 people. Community needs assessment and client and community surveys were used to define the problems. Patient care flowcharting and the creation of an electronic patient database facilitated patient tracking across the entire community. Clinical guidelines and a consultation and referral immunology clinic standardized care practices. Measurable improvements in the quality of care were noted in multiple areas. Flowchart completion rates rose from 44% to 100%; medication adherence assessment rose from 82% to 100%; immunization rates rose from a mean of 72% to a mean of 87%; PPD screening rose from a low of 35% to a high of 87%; perinatal transmission rates fell from 31% to 4%; and Emergency Department utilization decreased. Two essential components of the effort were the establishment of a full-time leadership position in the form of a clinical nurse practitioner and the creation of an electronic database with flowcharting to standardize the measurement, delivery and tracking of care. The programme has become an example of successful disease management through hospital-community collaboration
Glucocorticoid- and progesterone-specific effects are determined by differential expression of the respective hormone receptors
The Radio Light Curve of the Gamma-Ray Nova in V407 Cyg: Thermal Emission from the Ionized Symbiotic Envelope, Devoured from Within by the Nova Blast
We present multi-frequency radio observations of the 2010 nova event in the
symbiotic binary V407 Cygni, obtained with the Karl G. Jansky Very Large Array
and spanning 1-45 GHz and 17-770 days following discovery. This nova---the
first ever detected in gamma rays---shows a radio light curve dominated by the
wind of the Mira giant companion, rather than the nova ejecta themselves. The
radio luminosity grew as the wind became increasingly ionized by the nova
outburst, and faded as the wind was violently heated from within by the nova
shock. This study marks the first time that this physical mechanism has been
shown to dominate the radio light curve of an astrophysical transient. We do
not observe a thermal signature from the nova ejecta or synchrotron emission
from the shock, due to the fact that these components were hidden behind the
absorbing screen of the Mira wind.
We estimate a mass loss rate for the Mira wind of Mdot_w ~ 10^-6 M_sun/yr. We
also present the only radio detection of V407 Cyg before the 2010 nova, gleaned
from unpublished 1993 archival VLA data, which shows that the radio luminosity
of the Mira wind varies by a factor of >~20 even in quiescence. Although V407
Cyg likely hosts a massive accreting white dwarf, making it a candidate
progenitor system for a Type Ia supernova, the dense and radially continuous
circumbinary material surrounding V407 Cyg is inconsistent with observational
constraints on the environments of most Type Ia supernovae.Comment: Resubmitted to ApJ after incorporating referee's comment
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