3,809 research outputs found
Lean Concretes Using Kentucky\u27s Dense Graded Aggregate (Portland Cement and SS-1 Emulsified Asphalt)
Since the development of dense-graded aggregate base in Kentucky about 1952, there have been various conjectures about auto-cementations or setting of these materials when compacted and cured. In some cases, particularly when the material was limestone, they have developed rather surprising strengths, in the field as well as in the laboratory. Such displays of strength seem to be directly associated with curing (slow drying) and the possibility of re-deposition of small amounts of dissolved calcium carbonate as cement. If this is so, it might be surmised that bases which have not been fixed by curing and drying before surfacing may never acquire strength by virtue of auto-cementation, or may loose it on re-wetting. It may be surmised, likewise, that unless auto-cementation occurs, the supporting ability of the base must be governed by the binding power of whatever moisture is present and by virtue of physical confinement. Thus, the idea of deliberately introducing cement is quite logical if inherent strength is to be assured
Early stage morphology of quench condensed Ag, Pb and Pb/Ag hybrid films
Scanning Tunneling Microscopy (STM) has been used to study the morphology of
Ag, Pb and Pb/Ag bilayer films fabricated by quench condensation of the
elements onto cold (T=77K), inert and atomically flat Highly Oriented Pyrolytic
Graphite (HOPG) substrates. All films are thinner than 10 nm and show a
granular structure that is consistent with earlier studies of QC films. The
average lateral diameter, , of the Ag grains, however, depends on
whether the Ag is deposited directly on HOPG ( = 13 nm) or on a Pb
film consisting of a single layer of Pb grains ( = 26.8 nm). In
addition, the critical thickness for electrical conduction () of Pb/Ag
films on inert glass substrates is substantially larger than for pure Ag films.
These results are evidence that the structure of the underlying substrate
exerts an influence on the size of the grains in QC films. We propose a
qualitative explanation for this previously unencountered phenomenon.Comment: 11 pages, 3 figures and one tabl
1970: Abilene Christian College Bible Lectures - Full Text
THE APOSTLESβ DOCTRINE
Being the Abilene Christian College Annual Bible Lectures 1970
Published by
ABILENE CHRISTIAN COLLEGE BOOK STORE
ACC Station Abilene, Texas 7960
Testing the Nambu-Goldstone Hypothesis for Quarks and Leptons at the LHC
The hierarchy of the Yukawa couplings is an outstanding problem of the
standard model. We present a class of models in which the first and second
generation fermions are SUSY partners of pseudo-Nambu-Goldstone bosons that
parameterize a non-compact Kahler manifold, explaining the small values of
these fermion masses relative to those of the third generation. We also provide
an example of such a model. We find that various regions of the parameter space
in this scenario can give the correct dark matter abundance, and that nearly
all of these regions evade other phenomenological constraints. We show that for
gluino mass ~700 GeV, model points from these regions can be easily
distinguished from other mSUGRA points at the LHC with only 7 fb^(-1) of
integrated luminosity at 14 TeV. The most striking signatures are a dearth of
b- and tau-jets, a great number of multi-lepton events, and either an
"inverted" slepton mass hierarchy, narrowed slepton mass hierarchy, or
characteristic small-mu spectrum.Comment: Corresponds to published versio
Sex-biased parental care and sexual size dimorphism in a provisioning arthropod
The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort β for example where mothers transport heavy provisions to nests.
To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the motherβs weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest.
We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight.
Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species
1963: Abilene Christian College Bible Lectures - Full Text
THE CHRISTIAN AND MORALITYβ
Being the Abilene Christian College Annual Bible Lectures 1963
Price: $3.95
Published by
ABILENE CHRISTIAN COLLEGE STUDENTS EXCHANGE
ACC Station Abilene, Texa
A systematic review of the evidence for single stage and two stage revision of infected knee replacement
BACKGROUND:
Periprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates.
METHODS:
A systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded.
RESULTS:
63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies.
CONCLUSIONS:
Evidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority
Serum CA 19-9 as a Marker of Resectability and Survival in Patients with Potentially Resectable Pancreatic Cancer Treated with Neoadjuvant Chemoradiation
Purpose
The role of carbohydrate antigen (CA) 19-9 in the evaluation of patients with resectable pancreatic cancer treated with neoadjuvant therapy prior to planned surgical resection is unknown. We evaluated CA 19-9 as a marker of therapeutic response, completion of therapy, and survival in patients enrolled on two recently reported clinical trials.
Patients and Methods
We analyzed patients with radiographically resectable adenocarcinoma of the head/uncinate process treated on two phase II trials of neoadjuvant chemoradiation. Patients without evidence of disease progression following chemoradiation underwent pancreaticoduodenectomy (PD). CA 19-9 was evaluated in patients with a normal bilirubin level.
Results
We enrolled 174 patients, and 119 (68%) completed all therapy including PD. Pretreatment CA 19-9 <37 U/ml had a positive predictive value (PPV) for completing PD of 86% but a negative predictive value (NPV) of 33%. Among patients without evidence of disease at last follow-up, the highest pretreatment CA 19-9 was 1,125 U/ml. Restaging CA 19-9 <61 U/ml had a PPV of 93% and a NPV of 28% for completing PD among resectable patients. The area under the receiver-operating characteristics curve of pretreatment and restaging CA 19-9 levels for completing PD was 0.59 and 0.74, respectively. We identified no association between change in CA 19-9 and histopathologic response (P = 0.74).
Conclusions
Although the PPV of CA 19-9 for completing neoadjuvant therapy and undergoing PD was high, its clinical utility was compromised by a low NPV. Decision-making for patients with resectable PC should remain based on clinical assessment and radiographic staging.PublishedN/
'Collective Making' as knowledge mobilisation: the contribution of participatory design in the co-creation of knowledge in healthcare
The discourse in healthcare Knowledge Mobilisation (KMb) literature has shifted from simple, linear
models of research knowledge production and action to more iterative and complex models. These
aim to blend multiple stakeholdersβ knowledge with research knowledge to address the researchpractice
gap. It has been suggested there is no 'magic bullet', but that a promising approach to take is
knowledge co-creation in healthcare, particularly if a number of principles are applied. These include
systems thinking, positioning research as a creative enterprise with human experience at its core, and
paying attention to process within the partnership. This discussion paper builds on this proposition
and extends it beyond knowledge co-creation to co-designing evidenced based interventions and
implementing them. Within a co-design model, we offer a specific approach to share, mobilise and
activate knowledge, that we have termed 'collective making'. We draw on KMb, design, wider
literature, and our experiences to describe how this framework supports and extends the principles of
co-creation offered by Geenhalgh et al[1] in the context of the state of the art of knowledge
mobilisation. We describe how collective making creates the right βconditionsβ for knowledge to be
mobilised particularly addressing issues relating to stakeholder relationships, helps to discover, share
and blend different forms of knowledge from different stakeholders, and puts this blended
knowledge to practical use allowing stakeholders to learn about the practical implications of
knowledge use and to collectively create actionable products. We suggest this collective making has
three domains of influence: on the participants; on the knowledge discovered and shared; and on the
mobilisation or activation of this knowledge
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