11,639 research outputs found
Modular Decomposition and the Reconstruction Conjecture
We prove that a large family of graphs which are decomposable with respect to
the modular decomposition can be reconstructed from their collection of
vertex-deleted subgraphs.Comment: 9 pages, 2 figure
Biosensor measurement of purine release from cerebellar cultures and slices
We have previously described an action-potential
and Ca2+-dependent form of adenosine release in the
molecular layer of cerebellar slices. The most likely source
of the adenosine is the parallel fibres, the axons of granule cells. Using microelectrode biosensors, we have therefore investigated whether cultured granule cells (from postnatal day 7–8 rats) can release adenosine. Although no purine release could be detected in response to focal electrical stimulation, purine (adenosine, inosine or hypoxanthine) release occurred in response to an increase in extracellular K+ concentration from 3 to 25 mM coupled with addition of 1 mM glutamate. The mechanism of purine release was transport from the cytoplasm via an ENT transporter.
This process did not require action-potential firing but
was Ca2+dependent. The major purine released was not
adenosine, but was either inosine or hypoxanthine. In
order for inosine/hypoxanthine release to occur, cultures
had to contain both granule cells and glial cells; neither
cellular component was sufficient alone. Using the same
stimulus in cerebellar slices (postnatal day 7–25), it was
possible to release purines. The release however was not
blocked by ENT blockers and there was a shift in the Ca2+
dependence during development. This data from cultures
and slices further illustrates the complexities of purine
release, which is dependent on cellular composition and
developmental stage
Ureteropelvic junction obstruction caused by metastatic cholangiocarcinoma
We describe the rare case of a 61-year-old female with right ureteropelvic junction (UPJ) obstruction caused by metastatic cholangiocarcinoma. Her past medical history was notable for cholangiocarcinoma treated with neoadjuvant chemoradiation and two orthotopic liver transplants six years earlier. Urology was consulted when she presented with flank pain and urinary tract infection. Diagnostic workup demonstrated right UPJ obstruction. She was managed acutely with percutaneous nephrostomy. She subsequently underwent robotic pyeloplasty and intrinsic obstruction of the UPJ was discovered. Histological examination revealed adenocarcinoma, consistent with systemic recurrence of the patient\u27s known cholangiocarcinoma
Diet of rainbow trout in Lake Rotoiti: an energetic perspective
We characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout (Oncorhynchus mykiss) in Lake Rotoiti, New Zealand, to better understand the prey requirements of trout in central North Island lakes. Common smelt (Retropinna retropinna) was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by weight), followed by kōura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (Gobiomorphus cotidianus; 5.5%), and kōaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed kōaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (kōaro and kōura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetic modelling of rainbow trout populations in lakes of the central North Island of New Zealand
A National Veterans Strategy: The Economic, Social and Security Imperative
This publication details the foundational logic supporting a call to action, related to a broad-based effort to articulate and institutionalize a National Veterans Strategy. We argue that coordinated, "whole-of-government" action toward this end is essential to meet the nation's most important economic, social, and security obligations. Furthermore, we contend that the second Obama administration, working in close collaboration with executive agencies, Congress, and the private sector, is well-positioned to act on what we perceive to be a historic opportunity -- capitalizing on both the foundations of veteran-focused policy and progress enacted over the past decade and the overwhelming public support for returning veterans and military families -- to craft and institutionalize a National Veterans Strategy.Our purpose is to provide a researched and logically-developed case for action that is grounded in this nation's social and cultural traditions and attuned to the practical realities of our contemporary economic and political climate
A molecular superfluid: non-classical rotations in doped para-hydrogen clusters
Clusters of para-hydrogen (pH2) have been predicted to exhibit superfluid
behavior, but direct observation of this phenomenon has been elusive. Combining
experiments and theoretical simulations, we have determined the size evolution
of the superfluid response of pH2 clusters doped with carbon dioxide (CO2).
Reduction of the effective inertia is observed when the dopant is surrounded by
the pH2 solvent. This marks the onset of molecular superfluidity in pH2. The
fractional occupation of solvation rings around CO2 correlates with enhanced
superfluid response for certain cluster sizes
Recommended from our members
The Mechanism of Addition of Diazo-alkanes to Cyclopropanones
The addition of diazo-alkanes to cyclopropanones yields cyclobutanones whose structures may be predicted on the basis of conformational regulation of the migrating carbon-carbon bond
- …