1,656 research outputs found
A Graph Model for Imperative Computation
Scott's graph model is a lambda-algebra based on the observation that
continuous endofunctions on the lattice of sets of natural numbers can be
represented via their graphs. A graph is a relation mapping finite sets of
input values to output values.
We consider a similar model based on relations whose input values are finite
sequences rather than sets. This alteration means that we are taking into
account the order in which observations are made. This new notion of graph
gives rise to a model of affine lambda-calculus that admits an interpretation
of imperative constructs including variable assignment, dereferencing and
allocation.
Extending this untyped model, we construct a category that provides a model
of typed higher-order imperative computation with an affine type system. An
appropriate language of this kind is Reynolds's Syntactic Control of
Interference. Our model turns out to be fully abstract for this language. At a
concrete level, it is the same as Reddy's object spaces model, which was the
first "state-free" model of a higher-order imperative programming language and
an important precursor of games models. The graph model can therefore be seen
as a universal domain for Reddy's model
A Structured Blood Conservation Program in Pediatric Cardiac Surgery
OBJECTIVE: The limitation of alternative transfusion practices in infants increases the benefits of blood conservation. We analyzed the efficacy of a structured program to reduce transfusions and transfusion-associated complications in cardiac surgery
PATIENTS AND METHODS: Our pediatric surgery database was reviewed retrospectively, comparing outcomes from two different time periods, after the implementation of an effective blood conservation program beginning in March 2014. A total of 214 infants (8.1±3.4 months) who underwent biventricular repair utilizing CPB (Group 1 â Blood conservation) were studied in a 12-month period (March 2014-February 2015) after the implementation of the new program, and compared with 250 infants (7.91±3.2 months) (Group 2 â Control-No blood conservation) of the previous 12 â month period (March 2013-February 2014).
RESULTS: The proportion of patients transfused with red blood cells was 75.2% (N=188) in control group and reduced by 16.4% in the study group (58.8% â 126 patients, p
CONCLUSIONS: These findings, in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in pediatric cardiac operations. Circuit miniaturization, ultrafiltration, and reduced postoperative bleeding, presumably secondary to higher fibrinogen and other coagulation factor levels, contributed to this outcome
A Cardiopulmonary Bypass Based Blood Management Strategy in Adult Cardiac Surgery
BACKGROUND: Despite the recent introduction of a number of technical and pharmacologic blood conservation measures, bleeding and allogeneic transfusion remain persistent problems in open-heart surgical procedures. Efforts should be made to decrease or completely avoid transfusions to avoid these negative reactions. METHODS: Our coronary artery bypass grafting database was reviewed retrospectively and a total of 243 patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) were studied in a 12-month period (January-December 2016) after the implementation of the new program, and compared with 275 patients of the previous 12-month period.All the staff involved in the care of the patients were educated about the risks and benefits of blood transfusions and the new transfusion guidelines in a 45-min training. We revised our guidelines for transfusions based on the STS. A transfusion log was created. Reduction in IV fluid volume was targeted. CPB circuitry was redesigned to achieve significantly less prime volume. Results: The proportion of patients transfused with red blood cells was 56% (n =154) in the control group and reduced by 26.8% in the study group (29.2%; 71 patients; P \u3c .01). Blood transfusion rate (1.7 +./- 1/3.05 +./- 1 units), postoperative hemorrhage (545 +./- 50/ 775 +./- 55 mL), respiratory support duration (12.4 +./- 7/16.8 +./- 8 h) and ICU stay (2.2+./-1.1/ 3.5+./-1.2 days) were significantly better in the blood conservation group. Conclusion: These findings, in addition to risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in adult cardiac operations
The cosmic ray spectrum above 10(17) eV
The final analysis of the data obtained by the Sydney University Giant Airshower Recorder (SUGAR) is presented. The data has been reanalysed to take into account the effects of afterpulsing in the photomultiplier tubes. Event data was used to produce a spectrum of equivalent vertical muon number and from this a model dependent primary energy spectrum was obtained. These spectra show good evidence for the Ankle: a flattening at 10(19) eV. There is no sign of the cut-off which would be expected from the effects of the universal black body radiation
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Holdsworth Retrofit and Renovation
The University of Massachusetts has a rapidly evolving commitment to reducing greenhouse gas emissions and improving the environmental sustainability of its operations. According to the most recent IPCC report, the buildings sector has more potential to contribute to climate change mitigation than any other sector.1 The energy efficient designs of the current spate of building projects are indicative of the Universityâs commitment to green buildingâreducing the energy intensity of the university relative to building area and activities. However, these efforts cannot reduce the total energy use or greenhouse gas emissions from current levels. Among the Universityâs assets with the greatest potential to achieve these goals are its existing buildings.
Most of these are good buildings that have not reached the end of their useful life. Forty-two buildings, encompassing more than half of the general administration and educational space fall into the categories of âcatch up and keep upâ or âkeep and renewâ according to the universityâs Building Disposition Report.2 Many of the existing buildings have great historical, aesthetic, and emotional value and have stood the test of time as the site of the academic, scientific, and cultural work that is their primary purpose. Can these buildings be updated to dramatically reduce their energy consumption and allow them to continue to function as valuable assets for the long term? What levels of energy savings are possible and reasonable? This report is designed to answer these questions for one representative building: Holdsworth Hall.
The recommendations in this report are the product of a detailed and careful examination and exploration of the building and its operations. The investigations and proposed solutions are motivated by two principles: First, the architectural intention should be respected. The building as designed works well on many levels, and no recommendation should undermine currently effective systems and designs or compromise the aesthetic intention of its designers. Second, the building is a complex system, and no change can be considered in isolation. Single measures may achieve savings, but cannot maximize savings or performance without complementary changes in related systems. A final package of recommended measures will define a new building system with emergent properties that make for a qualitatively different and better building beyond simple energy consumption metrics. 1
Breaking the Mould and the Birth of a New Journal: Online Educational Research Journal
Academic journals are evolving and proliferating but despite their success there is much room for improvement. The traditional paper based model is expensive, constrained by space, exclusive and beset with problems of refereeing and publication time. The newer on-line journals go some way to dealing with these issues but they fail to capitalise on the possibilities opened up by the web. This paper launches a new journal Online Educational Research Journal (OERJ) which is free, unconstrained by space and accessible to all. It takes a novel approach to refereeing allowing discussion online and deals with the shortage of refereeing by requiring authors to reciprocate. A key feature of the journal is that papers are guaranteed to be published albeit anonymously in the first instance. After receiving the ratings and comments of referees which will go online the paper becomes onymous unless the author chooses to withdraw
Safe nights out: Workersâ perspectives on tackling violence against women and girls
Existing research focused on workers within the night-timeeconomy (NTE) is limited. In this unique study, research was conducted with workers from a wide range of professions and occupations. The study garnered important insights into NTE workersâ understanding and experience of violence against women and girls (VAWG).
Workers observed a strong relationship between alcohol consumption and VAWG and were knowledgeable about spiking, perceiving this practice to be growing. Strong protocols were in place to support women when spiking was alleged. The understanding of VAWG was, in contrast, broad but inconsistent. NTE workers provide myriad ways to support and protect women who are out at night. However, responses to potential incidents of VAWG are shaped by intuition, rather than being rooted in formal knowledge and institutional protocols. The decision to intervene is usually based on NTE workersâ levels of experience, confidence, and subjective perception of risk â described as âgoing with your gutâ.
There were, however, some good examples of where formal training had been provided and found to be useful. Specifically,there was evidence that many of the initiatives established as part of the Safer Streets project were making a difference. Respondents valued the training that they had received (such as zero-tolerance), and they recognised the important role that Street Pastors provide. Nevertheless, several training gaps were identified. Specifically, workers reported that they wanted to be better equipped to identify potential perpetrators of crime and would welcome advice on how to enhance personal and customer safety. NTE workers would also benefit from knowing more about the location and
value of safe havens.
The study showed that while many venues offer support to customers, there is some inconsistency in the way that safety measures are advertised and enacted
Rapid and extensive warming following cessation of solar radiation management
Solar radiation management (SRM) has been proposed as a means to alleviate the climate impacts of ongoing anthropogenic greenhouse gas (GHG) emissions. However, its efficacy depends on its indefinite maintenance, without interruption from a variety of possible sources, such as technological failure or global cooperation breakdown. Here, we consider the scenario in which SRMâvia stratospheric aerosol injectionâis terminated abruptly following an implementation period during which anthropogenic GHG emissions have continued. We show that upon cessation of SRM, an abrupt, spatially broad, and sustained warming over land occurs that is well outside 20th century climate variability bounds. Global mean precipitation also increases rapidly following cessation, however spatial patterns are less coherent than temperature, with almost half of land areas experiencing drying trends. We further show that the rate of warmingâof critical importance for ecological and human systemsâis principally controlled by background GHG levels. Thus, a risk of abrupt and dangerous warming is inherent to the large-scale implementation of SRM, and can be diminished only through concurrent strong reductions in anthropogenic GHG emissions.James S. McDonnell Foundation (Postdoctoral Fellowship)Tamaki FoundationNational Science Foundation (U.S.) (TeraGrid resources, Texas Advanced Computing Center, Grant TG-ATM090059
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